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testosterone therapy causes a shift in the skeletal muscle of CHF patients toward a higher concentration of type I muscle fibers

Testosterone replacement therapy has also been shown to improve the homeostatic model of insulin resistance and hemoglobin A1c in diabetics26,68–69 and to lower the BMI in obese patients.

Lower levels of endogenous testosterone have been associated with longer duration of the QTc interval

testosterone replacement has been shown to shorten the QTc interval

negative correlation has been demonstrated between endogenous testosterone levels and IMT of the carotid arteries, abdominal aorta, and thoracic aorta

These findings suggest that men with lower levels of endogenous testosterone may be at a higher risk of developing atherosclerosis.

Current guidelines from the Endocrine Society make no recommendations on whether patients with heart disease should be screened for hypogonadism and do not recommend supplementing patients with heart disease to improve survival.

The Massachusetts Male Aging Study also projects ≈481 000 new cases of hypogonadism annually in US men within the same age group

since 1993 prescriptions for testosterone, regardless of the formulation, have increased nearly 500%

Testosterone levels are lower in patients with chronic illnesses such as end‐stage renal disease, human immunodeficiency virus, chronic obstructive pulmonary disease, type 2 diabetes mellitus (T2DM), obesity, and several genetic conditions such as Klinefelter syndrome

A growing body of evidence suggests that men with lower levels of endogenous testosterone are more prone to develop CAD during their lifetimes

There are 2 major potential confounding factors that the older studies generally failed to account for. These factors are the subfraction of testosterone used to perform the analysis and the method used to account for subclinical CAD.

The biologically inactive form of testosterone is tightly bound to SHBG and is therefore unable to bind to androgen receptors

The biologically inactive fraction of testosterone comprises nearly 68% of the total testosterone in human serum

The biologically active subfraction of testosterone, also referred to as bioavailable testosterone, is either loosely bound to albumin or circulates freely in the blood, the latter referred to as free testosterone

It is estimated that ≈30% of total serum testosterone is bound to albumin, whereas the remaining 1% to 3% circulates as free testosterone

it can be argued that using the biologically active form of testosterone to evaluate the association with CAD will produce the most reliable results

English et al14 found statistically significant lower levels of bioavailable testosterone, free testosterone, and free androgen index in patients with catheterization‐proven CAD compared with controls with normal coronary arteries

patients with catheterization‐proven CAD had statistically significant lower levels of bioavailable testosterone

In conclusion, existing evidence suggests that men with CAD have lower levels of endogenous testosterone,13–18 and more specifically lower levels of bioavailable testosterone

low testosterone levels are associated with risk factors for CAD such as T2DM25–26 and obesity

In a meta‐analysis of these 7 population‐based studies, Araujo et al41 showed a trend toward increased cardiovascular mortality associated with lower levels of total testosterone, but statistical significance was not achieved (RR, 1.25

the authors showed that a decrease of 2.1 standard deviations in levels of total testosterone was associated with a 25% increase in the risk of cardiovascular mortality

the relative risk of all‐cause mortality in men with lower levels of total testosterone was calculated to be 1.35

higher risk of cardiovascular mortality is associated with lower levels of bioavailable testosterone

Existing evidence seems to suggest that lower levels of endogenous testosterone are associated with higher rates of all‐cause mortality and cardiovascular mortality

studies have shown that lower levels of endogenous bioavailable testosterone are associated with higher rates of all‐cause and cardiovascular mortality

It may be possible that using bioavailable testosterone to perform mortality analysis will yield more accurate results because it prevents the biologically inactive subfraction of testosterone from playing a potential confounding role in the analysis

The earliest published material on this matter dates to the late 1930s

the concept that testosterone replacement therapy improves angina has yet to be proven wrong

In more recent studies, 3 randomized, placebo‐controlled trials demonstrated that administration of testosterone improves myocardial ischemia in men with CAD

The improvement in myocardial ischemia was shown to occur in response to both acute and chronic testosterone therapy and seemed to be independent of whether an intravenous or transdermal formulation of testosterone was used.

testosterone had no effect on endothelial nitric oxide activity

There is growing evidence from in vivo animal models and in vitro models that testosterone induces coronary vasodilation by modulating the activity of ion channels, such as potassium and calcium channels, on the surface of vascular smooth muscle cells

Experimental studies suggest that the most likely mechanism of action for testosterone on vascular smooth muscle cells is via modulation of action of non‐ATP‐sensitive potassium ion channels, calcium‐activated potassium ion channels, voltage‐sensitive potassium ion channels, and finally L‐type calcium ion channels

Corona et al confirmed those results by demonstrating that not only total testosterone levels are lower among diabetics, but also the levels of free testosterone and SHBG are lower in diabetic patients

Laaksonen et al65 followed 702 Finnish men for 11 years and demonstrated that men in the lowest quartile of total testosterone, free testosterone, and SHBG were more likely to develop T2DM and metabolic syndrome.

Vikan et al followed 1454 Swedish men for 11 years and discovered that men in the highest quartile of total testosterone were significantly less likely to develop T2DM

authors demonstrated a statistically significant increase in the incidence of T2DM in subjects receiving gonadotropin‐releasing hormone antagonist therapy. In addition, a significant increase in the rate of myocardial infarction, stroke, sudden cardiac death, and development of cardiovascular disease was noted in patients receiving antiandrogen therapy.67

Several authors have demonstrated that the administration of testosterone in diabetic men improves the homeostatic model of insulin resistance, hemoglobin A1c, and fasting plasma glucose

Existing evidence strongly suggests that the levels of total and free testosterone are lower among diabetic patients compared with those in nondiabetics

insulin seems to be acting as a stimulant for the hypothalamus to secret gonadotropin‐releasing hormone, which consequently results in increased testosterone production. It can be argued that decreased stimulation of the hypothalamus in diabetics secondary to insulin deficiency could result in hypogonadotropic hypogonadism

BMI has been shown to be inversely associated with testosterone levels

This interaction may be a result of the promotion of lipolysis in abdominal adipose tissue by testosterone, which may in turn cause reduced abdominal adiposity. On the other hand, given that adipose tissue has a higher concentration of the enzyme aromatase, it could be that increased adipose tissue results in more testosterone being converted to estrogen, thereby causing hypogonadism. Third, increased abdominal obesity may cause reduced testosterone secretion by negatively affecting the hypothalamus‐pituitary‐testicular axis. Finally, testosterone may be the key factor in activating the enzyme 11‐hydroxysteroid dehydrogenase in adipose tissue, which transforms glucocorticoids into their inactive form.

increasing age may alter the association between testosterone and CRP. Another possible explanation for the association between testosterone level and CRP is central obesity and waist circumference

Bai et al have provided convincing evidence that testosterone might be able to shorten the QTc interval by augmenting the activity of slowly activating delayed rectifier potassium channels while simultaneously slowing the activity of L‐type calcium channels

consistent evidence that supplemental testosterone shortens the QTc interval.

Intima‐media thickness (IMT) of the carotid artery is considered a marker for preclinical atherosclerosis

Studies have shown that levels of endogenous testosterone are inversely associated with IMT of the carotid artery,126–128,32,129–130 as well as both the thoracic134 and the abdominal aorta

1 study has demonstrated that lower levels of free testosterone are associated with accelerated progression of carotid artery IMT

another study has reported that decreased levels of total and bioavailable testosterone are associated with progression of atherosclerosis in the abdominal aorta

These findings suggest that normal physiologic testosterone levels may help to protect men from the development of atherosclerosis

Czesla et al successfully demonstrated that the muscle specimens that were exposed to metenolone had a significant shift in their composition toward type I muscle fibers

Type I muscle fibers, also known as slow‐twitch or oxidative fibers, are associated with enhanced strength and physical capability

It has been shown that those with advanced CHF have a higher percentage of type II muscle fibers, based on muscle biopsy

Studies have shown that men with CHF suffer from reduced levels of total and free testosterone.137 It has also been shown that reduced testosterone levels in men with CHF portends a poor prognosis and is associated with increased CHF mortality.138 Reduced testosterone has also been shown to correlate negatively with exercise capacity in CHF patients.

Testosterone replacement therapy has been shown to significantly improve exercise capacity, without affecting LVEF

the results of the 3 meta‐analyses seem to indicate that testosterone replacement therapy does not cause an increase in the rate of adverse cardiovascular events

Data from 3 meta‐analyses seem to contradict the commonly held belief that testosterone administration may increase the risk of developing prostate cancer

One meta‐analysis reported an increase in all prostate‐related adverse events with testosterone administration.146 However, when each prostate‐related event, including prostate cancer and a rise in PSA, was analyzed separately, no differences were observed between the testosterone group and the placebo group

the existing data from the 3 meta‐analyses seem to indicate that testosterone replacement therapy does not increase the risk of adverse cardiovascular events

the authors correctly point out the weaknesses of their study which include retrospective study design and lack of randomization, small sample size at extremes of follow‐up, lack of outcome validation by chart review and poor generalizability of the results given that only male veterans with CAD were included in this study

the studies that failed to find an association between testosterone and CRP used an older population group

low testosterone may influence the severity of CAD by adversely affecting the mediators of the inflammatory response such as high‐sensitivity C‐reactive protein, interleukin‐6, and tumor necrosis factor–α

The presence of symptoms was more closely linked to increasing age than to testosterone levels

Findings similar to type 2 diabetes were reported for men with the metabolic syndrome, which were associated with reductions in total testosterone of −2.2 nmol/l (95% CI −2.41 to 1.94) and in free testosterone

low testosterone is more predictive of the metabolic syndrome in lean men

Cross-sectional studies uniformly show that 30–50% of men with type 2 diabetes have lowered circulating testosterone levels, relative to references based on healthy young men

In a recent cross-sectional study of 240 middle-aged men (mean age 54 years) with either type 2 diabetes, type 1 diabetes or without diabetes (Ng Tang Fui et al. 2013b), increasing BMI and age were dominant drivers of low total and free testosterone respectively.

both diabetes and the metabolic syndrome are associated with a modest reduction in testosterone, in magnitude comparable with the effect of 10 years of ageing

In a cross-sectional study of 490 men with type 2 diabetes, there was a strong independent association of low testosterone with anaemia

In men, low testosterone is a marker of poor health, and may improve our ability to predict risk

low testosterone identifies men with an adverse metabolic phenotype

Diabetic men with low testosterone are significantly more likely to be obese or insulin resistant

increased inflammation, evidenced by higher CRP levels

Bioavailable but not free testosterone was independently predictive of mortality

It remains possible that low testosterone is a consequence of insulin resistance, or simply a biomarker, co-existing because of in-common risk factors.

In prospective studies, reviewed in detail elsewhere (Grossmann et al. 2010) the inverse association of low testosterone with metabolic syndrome or diabetes is less consistent for free testosterone compared with total testosterone

In a study from the Framingham cohort, SHBG but not testosterone was prospectively and independently associated with incident metabolic syndrome

low SHBG (Ding et al. 2009) but not testosterone (Haring et al. 2013) with an increased risk of future diabetes

In cross-sectional studies of men with (Grossmann et al. 2008) and without (Bonnet et al. 2013) diabetes, SHBG but not testosterone was inversely associated with worse glycaemic control

SHBG may have biological actions beyond serving as a carrier protein for and regulator of circulating sex steroids

In men with diabetes, free testosterone, if measured by gold standard equilibrium dialysis (Dhindsa et al. 2004), is reduced

Low free testosterone remains inversely associated with insulin resistance, independent of SHBG (Grossmann et al. 2008). This suggests that the low testosterone–dysglycaemia association is not solely a consequence of low SHBG.

Experimental evidence reviewed below suggests that visceral adipose tissue is an important intermediate (rather than a confounder) in the inverse association of testosterone with insulin resistance and metabolic disorders.

testosterone promotes the commitment of pluripotent stem cells into the myogenic lineage and inhibits their differentiation into adipocytes

testosterone regulates the metabolic functions of mature adipocytes (Xu et al. 1991, Marin et al. 1995) and myocytes (Pitteloud et al. 2005) in ways that reduce insulin resistance.

Pre-clinical evidence (reviewed in Rao et al. (2013)) suggests that at the cellular level, testosterone may improve glucose metabolism by modulating the expression of the glucose-transported Glut4 and the insulin receptor, as well as by regulating key enzymes involved in glycolysis.

More recently testosterone has been shown to protect murine pancreatic β cells against glucotoxicity-induced apoptosis

Interestingly, a reciprocal feedback also appears to exist, given that not only chronic (Cameron et al. 1990, Allan 2013) but also, as shown more recently (Iranmanesh et al. 2012, Caronia et al. 2013), acute hyperglycaemia can lower testosterone levels.

There is also evidence that testosterone regulates insulin sensitivity directly and acutely

In men with prostate cancer commencing androgen deprivation therapy, both total as well as, although not in all studies (Smith 2004), visceral fat mass increases (Hamilton et al. 2011) within 3 months

More prolonged (>12 months) androgen deprivation therapy has been associated with increased risk of diabetes in several large observational registry studies

Testosterone has also been shown to reduce the concentration of pro-inflammatory cytokines in some, but not all studies, reviewed recently in Kelly & Jones (2013). It is not know whether this effect is independent of testosterone-induced changes in body composition.

the observations discussed in this section suggest that it is the decrease in testosterone that causes insulin resistance and diabetes. One important caveat remains: the strongest evidence that low testosterone is the cause rather than consequence of insulin resistance comes from men with prostate cancer (Grossmann & Zajac 2011a) or biochemical castration, and from mice lacking the androgen receptor.

Several large prospective studies have shown that weight gain or development of type 2 diabetes is major drivers of the age-related decline in testosterone levels

there is increasing evidence that healthy ageing by itself is generally not associated with marked reductions in testosterone

Circulating testosterone, on an average 30%, is lower in obese compared with lean men

increased visceral fat is an important component in the association of low testosterone and insulin resistance

The vast majority of men with metabolic disorders have functional gonadal axis suppression with modest reductions in testosterone levels

obesity is a dominant risk factor

men with Klinefelter syndrome have an increased risk of metabolic disorders. Interestingly, greater body fat mass is already present before puberty

Only 5% of men with type 2 diabetes have elevated LH levels

inhibition of the gonadal axis predominantly takes place in the hypothalamus, especially with more severe obesity

Metabolic factors, such as leptin, insulin (via deficiency or resistance) and ghrelin are believed to act at the ventromedial and arcuate nuclei of the hypothalamus to inhibit gonadotropin-releasing hormone (GNRH) secretion from GNRH neurons situated in the preoptic area

kisspeptin has emerged as one of the most potent secretagogues of GNRH release

hypothesis that obesity-mediated inhibition of kisspeptin signalling contributes to the suppression of the HPT axis, infusion of a bioactive kisspeptin fragment has been recently shown to robustly increase LH pulsatility, LH levels and circulating testosterone in hypotestosteronaemic men with type 2 diabetes

A smaller study with a similar experimental design found that acute testosterone withdrawal reduced insulin sensitivity independent of body weight, whereas oestradiol withdrawal had no effects

suppression of the diabesity-associated HPT axis is functional, and may hence be reversible

Obesity and dysglycaemia and associated comorbidities such as obstructive sleep apnoea (Hoyos et al. 2012b) are important contributors to the suppression of the HPT axis

weight gain and development of diabetes accelerate the age-related decline in testosterone

Modifiable risk factors such as obesity and co-morbidities are more strongly associated with a decline in circulating testosterone levels than age alone

55% of symptomatic androgen deficiency reverted to a normal testosterone or an asymptomatic state after 8-year follow-up, suggesting that androgen deficiency is not a stable state

Weight loss can reactivate the hypothalamic–pituitary–testicular axis

Leptin treatment resolves hypogonadism in leptin-deficient men

The hypothalamic–pituitary–testicular axis remains responsive to treatment with aromatase inhibitors or selective oestrogen receptor modulators in obese men

Kisspeptin treatment increases LH secretion, pulse frequency and circulating testosterone levels in hypotestosteronaemic men with type 2 diabetes

change in BMI was associated with the change in testosterone (Corona et al. 2013a,b).

weight loss can lead to genuine reactivation of the gonadal axis by reversal of obesity-associated hypothalamic suppression

There is pre-clinical and observational evidence that chronic hyperglycaemia can inhibit the HPT axis

in men who improved their glycaemic control over time, testosterone levels increased. By contrast, in those men in whom glycaemic control worsened, testosterone decreased

testosterone levels should be measured after successful weight loss to identify men with an insufficient rise in their testosterone levels. Such men may have HPT axis pathology unrelated to their obesity, which will require appropriate evaluation and management.

of the approximately 108 cannabinoids produced by C. sativa, Δ9-tetrahydrocannabinol (thc) is the most relevant because of its high potency and abundance in plant preparations

Tetrahydrocannabinol exerts a wide variety of biologic effects by mimicking endogenous substances—the endocannabinoids anandamide3 and 2-arachidonoylglycerol4,5—that engage specific cell-surface cannabinoid receptors

the cb2 receptor was initially described to be present in the immune system6, but was more recently shown to also be expressed in cells from other origins

transient receptor potential cation channel subfamily V, member 1

orphan G protein–coupled receptor 55

Most of the effects produced by cannabinoids in the nervous system and in non-neural tissues rely on cb1 receptor activation

two major cannabinoid-specific receptors—cb1 and cb2

cardiovascular tone, energy metabolism, immunity, and reproduction

cannabinoids are well known to exert palliative effects in cancer patients

best-established use is the inhibition of chemotherapy-induced nausea and vomiting

thc and other cannabinoids exhibit antitumour effects in a wide array of animal models of cancer

cannabinoid receptors and their endogenous ligands are both generally upregulated in tumour tissue compared with non-tumour tissue

cb2 promotes her2 (human epidermal growth factor receptor 2) pro-oncogenic signalling in breast cancer

pharmacologic activation of cannabinoid receptors decreases tumour growth

endocannabinoid signalling can also have a tumour-suppressive role

pharmacologic stimulation of cb receptors is, in most cases, antitumourigenic. Nonetheless, a few reports have proposed a tumour-promoting effect of cannabinoids

most prevalent effect is the induction of cancer cell death by apoptosis and the inhibition of cancer cell proliferation

impair tumour angiogenesis and block invasion and metastasis

thc and other cannabinoids induce the apoptotic death of glioma cells by cb1- and cb2-dependent stimulation

Autophagy is primarily a cytoprotective mechanism, although its activation can also lead to cell death

autophagy is important for cannabinoid antineoplastic activity

autophagy is upstream of apoptosis in the mechanism of cannabinoid-induced cell death

the effect of cannabinoids in hormone- dependent tumours might rely, at least in part, on the ability to interfere with the activation of growth factor receptors

glioma cells), pharmacologic blockade of either cb1 or cb2 prevents cannabinoid-induced cell death with similar efficacy

other types of cancer cells (pancreatic48, breast24, or hepatic43 carcinoma cells, for example), antagonists of cb2 but not of cb1 inhibit cannabinoid antitumour actions

thc promotes cancer cell death in a cb1- or cb2-dependent manner (or both) at lower concentrations

cannabidiol (cbd), a phytocannabinoid with a low affinity for cannabinoid receptors15, and other marijuana-derived cannabinoids57 have also been proposed to promote the apoptotic death of cancer cells acting independently of the cb1 and cb2 receptors

In cancer cells, cannabinoids block the activation of the vascular endothelial growth factor (vegf) pathway, an inducer of angiogenesi

In vascular endothelial cells, cannabinoid receptor activation inhibits proliferation and migration, and induces apoptosis

cb1 or cb2 receptor agonists (or both) reduce the formation of distant tumour masses in animal models of both induced and spontaneous metastasis, and inhibit adhesion, migration, and invasiveness of glioma64, breast65,66, lung67,68, and cervical68 cancer cells in culture

the ceramide/p8–regulated pathway plays a general role in the antitumour activity of cannabinoids targeting cb1 and cb2

cbd, by acting independently of the cb1 and cb2 receptors, produces a remarkable anti-tumour effect—including reduction of invasiveness and metastasis

cannabinoids can also enhance immune system–mediated tumour surveillance in some contexts

ability of thc to reduce inflammation75,76, an effect that might prevent certain types of cancer

recent observations suggest that the combined administration of cannabinoids with other anticancer drugs acts synergistically to reduce tumour growth

combined administration of gemcitabine (the benchmark agent for the treatment of pancreatic cancer) and various cannabinoid agonists synergistically reduced the viability of pancreatic cancer cells

Other reports indicated that anandamide and HU-210 might also enhance the anticancer activity of paclitaxel89 and 5-fluorouracil90 respectively

Combined administration of thc and cbd enhances the anticancer activity of thc and reduces the dose of thc needed to induce its tumour growth-inhibiting activity

Preclinical animal models have yielded data indicating that systemic (oral or intraperitoneal) administration of cannabinoids effectively decreases tumour growth

Combinations of cannabinoids with classical chemotherapeutic drugs such as the alkylating agent temozolomide (the benchmark agent for the management of glioblastoma80,84) have been shown to produce a strong anticancer action in animal models

pharmacologic inhibition of egfr, erk83, or akt enhances the cell-death-promoting action of thc in glioma cultures (unpublished observations by the authors), which suggests that targeting egfr and the akt and erk pathways could enhance the antitumour effect of cannabinoids

We sought to systematically evaluate the evidence base for all new drugs and new indications for the treatment of solid tumours and haematological malignancies approved by the EMA in the five year period 2009-13

Three investigators (AP, EP, and EG) independently extracted data on and descriptively analysed the following trial features: characteristics of the participant population, study design (randomisation, crossover from experimental to control group, and blinding of investigators and participants), experimental and control groups, enrolment, primary and secondary endpoints, magnitude of benefit on survival and quality of life, and narrative interpretation of the findings

Only 18 of the 68 (26%) were supported by a pivotal study powered to evaluate overall survival as the primary outcome

From 2009 to 2013, the EMA approved use of 48 oncology drugs

Seventeen drugs were approved for treatment of haematological malignancies and 51 for treatment of solid tumours

Overall, 72 clinical trials supported the approval of 68 novel drug uses

Our scoring was limited to drugs for solid tumours

Among 68 cancer drug indications approved by the EMA in the period 2009-13, and with a median of 5.4 years’ follow-up, only 35 (51%) were associated with a significant improvement in survival (26/35) or quality of life (9/35) over existing treatment options, placebo, or as add on treatment

Only two of the 26 drugs shown to extend life also showed benefits on quality of life

33 (49%) had not shown any improvement on survival or quality of life

This systematic evaluation of oncology drug approvals by the EMA in 2009-13 shows that most of the drugs (39/68, 57%) entered the market without evidence of improved survival or quality of life

At a minimum 3.3 years after market entry, there was still no conclusive evidence that 33 of these 39 cancer drugs either extended or improved life

What are potential reasons for the paucity of drug approvals with demonstrable survival advantages over existing treatments?

Firstly, only 18 (26%) indications for use in our cohort were supported by trials in which extension of life was the primary outcome

None of the pivotal studies supporting oncology drug approvals from 2009 to 2013 included quality of life as a primary outcome measure

Most new oncology drugs authorised by the EMA in 2009-13 came onto the market without clear evidence that they improved the quality or quantity of patients’ lives

the mortality rate of EOC has not been significantly changed for several decades

Sequencing revealed that almost all tumors (96%) had mutations in TP53, which serves as a major driver of this cancer

Low-prevalence but statistically significant mutations in nine other genes including NF1, BRCA1, BRCA2, RB1, and CDK12 were also identified, but the majority of genes were mutated at low frequency, making it difficult to distinguish between driver and passenger mutations

KPNB1 inhibition via any of three KPNB1 siRNAs or importazole treatment induced apoptosis in human EOC cell lines (Fig. 3 A–F and Fig. S4), and was accompanied by an increase in the expression levels of the proapoptotic proteins BAX and cleaved caspase-3

Stable overexpression of KPNB1 in SKOV3 and OVCAR3 (Fig. S6) significantly accelerated cell proliferation/survival (Fig. 5 A–C), confirming that KPNB1 functions as an oncogene in EOC

KPNB1 overexpression significantly decreased caspase-3/7 activity (Fig. 5D), in addition to the expression levels of cleaved caspase-3 and BAX proteins (Fig. 5E). KPNB1 overexpression also decreased p21 and p27 protein levels (Fig. 5E), as opposed to their increase by KPNB1 inhibition

KPNB1 functions as an antiapoptotic and proproliferative oncogene in EOC.

Patients with higher expression levels of KPNB1 showed earlier recurrence and worse prognosis than those with lower expression levels of KPNB1

KPNB1 acts as an oncogene in human EOC and represents a promising therapeutic target.

ivermectin treatment suppressed cell proliferation/viability in a dose-dependent manner (Fig. 7A), indicating that it exerts an antitumor effect on EOC

ivermectin also induced apoptosis

ivermectin increased the expression levels of BAX, and cleaved PARP, as well as p21 and p27

KPNB1 inhibition is responsible for the antitumor effect of ivermectin

we found that ivermectin synergistically reduced cell proliferation/viability in combination with paclitaxel in human EOC cells

Single treatment of ivermectin or paclitaxel reduced tumor growth in nude mice, but, notably, combination treatment of ivermectin and paclitaxel almost completely suppressed tumor growth

ERBB2, is amplified and overexpressed in many cancers, including breast (31), ovary (31), colon (32), bladder (33), non-small-cell lung (34), and gastric cancer (35), and is a poor prognostic factor in certain cancer types

KPNB1 was the second-highest-ranked gene identified in our screen

Increased KPNB1 protein levels have been reported in several cancers, including cervical cancer (42), hepatocellular carcinoma (43), and glioma (44), suggesting KPNB1’s oncogenic potential in these tumor types

our findings suggest that KPNB1 might serve as a master regulator of cell cycle by regulating several cell cycle-related proteins, including p21, p27, and APC/C family members

higher and/or more-frequent doses of ivermectin than currently approved for humans are well tolerated in humans

none of the mice in this study treated with the effective dosage of ivermectin for in vivo anticancer therapy showed severe adverse event

we found that the combination of ivermectin and paclitaxel produces a stronger antitumor effect on EOC cell lines than either drug alone

secretion of MCP-1, resistin, and other proinflammatory cytokines is increased by obesity, the adipose secretion of the anti-inflammatory protein adiponectin is decreased

the peroxisome proliferators- activated receptor (PPAR) family are involved in the regulation of inflammation and energy homestasis

natural agonists, including unsaturated fatty acids and eicosanoids

PPARα also regulates inflammatory processes, mainly by inhibiting inflammatory gene expression

upregulation of COX-2 is seen in alcoholic steatohepatitis and nonalcoholic steatohepatitis and has been directly linked to the progression of steatosis to steatohepatitis, the inhibitory effect of PPARα on COX-2 may reduce steatohepatitis

PPARα agonists have a clear anorexic effect resulting in decreased food intake, evidence is accumulating that PPARα may also directly influence adipose tissue function, including its inflammatory status.

PPARα may govern adipose tissue inflammation in three different ways: (1) by decreasing adipocyte hypertrophy, which is known to be connected with a higher inflammatory status of the tissue [3, 11, 59], (2) by direct regulation of inflammatory gene expression via locally expressed PPARα, or (3) by systemic events likely originating from liver

PPARγ is considered the master regulator of adipogenesis

Unsaturated fatty acids and several eicosanoids serve as endogenous agonists of PPARγ

PPARγ2, which is adipose-tissue specific

two different molecular mechanisms have been proposed by which anti-inflammatory actions of PPARγ are effectuated: (1) via interference with proinflammatory transcription factors including STAT, NF-κB, and AP-1

and (2) by preventing removal of corepressor complexes from gene promoter regions resulting in suppression of inflammatory gene transcription

diet-induced obesity is associated with increased inflammatory gene expression in adipose tissue via adipocyte hypertrophy and macrophage infiltration

PPARγ is able to reverse macrophage infiltration, and subsequently reduces inflammatory gene expression

Inflammatory adipokines mainly originate from macrophages which are part of the stromal vascular fraction of adipose tissue [18, 19], and accordingly, the downregulation of inflammatory adipokines in WAT by PPARγ probably occurs via effects on macrophages

By interfering with NF-κB signaling pathways, PPARγ is known to decrease inflammation in activated macrophages

Recent data suggest that activation of PPARγ in fatty liver may protect against inflammation

PPARs may influence the inflammatory response either by direct transcriptional downregulation of proinflammatory genes

anti-inflammatory properties of PPARs in human obesity

aging in men is associated with decreases in bone mineral density (BMD) (18, 19), lean body and muscle mass

strength (22, 23) and aerobic capacity (24), as well as with increases in total and abdominal body fat, low-density lipoprotein cholesterol, and/or low-density lipoprotein/high-density lipoprotein cholesterol ratios (25, 26, 27, 28), all of which also occur in nonelderly hypogonadal men

Most (1, 5, 6, 7, 8, 9), but not all (10, 11, 12), cross-sectional studies have demonstrated a decrease, with age, in total T in men

total T, but not free T index, tended to decrease with greater BMI is consistent with prior studies showing that obesity is associated with decreases in both SHBG and total T, with an unchanged T-to-SHBG ratio

The conventional definition for T levels is statistical (values more than 2 sd below the mean), rather than functional. Such a definition does not reflect clinical realities, such as the existence of characteristic individual set points for circulating hormone levels, below which one, but not another, individual may develop metabolic changes of hormone deficiency; nor does it address the concept of reserve capacity, the possibility that persons with hormone levels 2 sd below the population mean still may have adequate hormone concentrations to meet their metabolic needs.

both T and free T index (a calculated value related to free or bioavailable T) decreased progressively at a rate that did not vary significantly with age, from the third to the ninth decades.

contrasts with other studies showing diminished free, as well as total, T in with increasing total (48) or abdominal (49) obesity in men.

Our analysis of date-adjusted T and free T index levels, by decade, showed that relatively high numbers of older men in this generally healthy population had at least one hypogonadal value (defined as below the 2.5th percentile for young men)

The issue of how properly to define hypogonadism, or indeed any hormone deficiency, remains problematic

The decrease in free T index was somewhat steeper than that of total T, owing to a trend for an increase in SHBG with age

LH for gonadal function

It would clearly be better to define the lower limit of normal for a hormone as: the blood level at which metabolic and/or clinical sequelae of hormone deficiency begin to appear, or the level below which definite benefits can be demonstrated for hormone supplementation for a significant proportion of the population

an effect of aging to lower both total and bioavailable circulating T levels at a relatively constant rate, independent of obesity, illness, medications, cigarette smoking, or alcohol intake

progesterone

prolactin

In summary, in vivo animal experiments have shown an inhibitory role of estrogen on peripheral NK cell lytic activity, which is partly due to suppression of NK cell output by the bone marrow and partly due to suppression of individual NK cell cytotoxicity. However, in vitro studies so far have failed to show conclusively a direct effect of estrogen on NK cells.

At the progesterone concentrations believed to be present in the uterus [up to 10−5 m at the maternal-fetal interface (35)], studies consistently show inhibition of lymphocyte proliferation (33) and inhibition of NK cytolytic activity in vitro

The exact role of prolactin in NK cell regulation is unknown.

The overall effects of estrogen on NK cells are likely multifactorial, therefore, and depend on the type of cell affected as well as the kind of ER expressed by that cell.

It is known that progesterone can directly affect T cell differentiation in vitro, suppressing development of the Th1 pathway and enhancing differentiation along the Th2 pathway (44)

Th1 cells predominantly produce interferon-γ (IFN-γ), IL-2, and TNF-β and are involved in cell-mediated immunity. Th2 cells produce IL-4, IL-5, IL-6, IL-10, and IL-13 and stimulate humoral immunity

Furthermore, in response to progesterone, γδ T cells produce progesterone-induced blocking factor (PIBF) (54

A defining characteristic of NK cells is their ability to lyse target cells without prior sensitization and without restriction by HLA antigens.

NK cell function is mainly regulated by IL-2 and IFN-γ

IL-2 causes both NK cell proliferation and enhanced cytotoxicity. IFN-γ augments NK cytolytic activity, but does not cause NK proliferation. The two cytokines act synergistically to augment NK cytotoxicity (6).

The largest leukocyte population in the endometrium consists of NK cells named large granulated lymphocytes

there is a significant increase in the number of uNK cells throughout the secretory phase, which peaks in early pregnancy when uNK cells comprise about 75% of uterine leukocytes (62)

Second, uNK cell phenotype changes during the normal menstrual cycle and early pregnancy (68)

general proinflammatory effect of estrogen, causing an influx of macrophages and neutrophils, which is antagonized by progesterone through its receptor (70, 71).

The mechanism of such a progesterone-induced local immunosuppression is unclear.

progesterone plays an important role in proliferation and differentiation of uNK cells (32).

Through promotion of a uterine Th2 environment, progesterone could indirectly affect uNK cell function

The mechanism of this increase in uNK cell numbers has been addressed in both human and mouse models, and is likely the result of: 1) recruitment of peripheral NK cells to the uterus, and 2) proliferation of existing uNK cells

prolactin system plays an important role in implantation and the maintenance of pregnancy

the exact pathways of hormonal regulation of NK cells remain to be delineated.

The exact function of uNK cells has not yet been unequivocally determined

uNK cells express a different cytokine profile, compared with resting peripheral NK cells. mRNAs for granulocyte CSF, M-CSF, GM-CSF, TNF-α, IFN-γ, TGF-β, and leukemia inhibitory factor (LIF) have been found in decidual CD56+ cells

Their increased numbers in early pregnancy, their hormonal dependence, and their close proximity to the infiltrating trophoblast all suggest that they play an important role in the regulation of the maternal immune response to the fetal allograft and the control of trophoblast growth and invasion during human pregnancy

role of uNK cell-derived cytokines on trophoblast growth and differentiation (114, 115, 116, 117).

Th1 immunity to trophoblast is associated with RPL, whereas Th2 immunity is associated with a successful pregnancy

RPL is associated with Th1 immunity, for which NK cells are partly responsible.

Activation of NF-κB can also be blocked by several other thiol-containing antioxidants including N-acetyl-l-cysteine (NAC)

Other clinically available antioxidants reported to have antiinflammatory, antioncogenic, and/or antiatherogenic properties that have been shown to block the activation of NF-κB include resveratrol (115, 116), (-)-epicatechin-3-gallate (117), pycnogenol (118), silymarin (119), and curcumin (120)

metabolic activity, oxygen transport, and DNA synthesis

Iron is found in the human body in the form of haemoglobin in red blood cells and growing erythroid cells.

macrophages contain considerable quantities of iron

iron is taken up by the majority of cells in the form of a transferrin (Tf)-Fe(III) complex that binds to the cell surface receptor transferrin receptor 1 (TfR1)

excess iron is retained in the liver cells

the endosomal six transmembrane epithelial antigen of the prostate 3 (STEAP3) reduces Fe(III) (ferric ion) to Fe(II) (ferrous ion), which is subsequently transferred across the endosomal membrane by divalent metal transporter 1 (DMT1)

labile iron pool (LIP)

LIP is toxic to the cells owing to the production of massive amounts of ROS.

DHA is quickly converted to Vit-C within the cell, by interacting with reduced glutathione (GSH) [45,46,47]. NADPH then recycles the oxidized glutathione (glutathione disulfide (GSSG)) and converts it back into GSH

Fe(II) catalyzes the formation of OH• and OH− during the interaction between H2O2 and O2•− (Haber–Weiss reaction)

Ascorbate can efficiently reduce free iron, thus recycling the cellular Fe(II)/Fe(III) to produce more OH• from H2O2 than can be generated during the Fenton reaction, which ultimately leads to lipid, protein, and DNA oxidation

Vit-C-stimulated iron absorption

reduce cellular iron efflux

high-dose Vit-C may elevate cellular LIP concentrations

ascorbate enhanced cancer cell LIP specifically by generating H2O2

Vit-C produces H2O2 extracellularly, which in turn inhibits tumor cells immediately

tumor cells have a need for readily available Fe(II) to survive and proliferate.

Tf has been recognized to sequester most labile Fe(II) in vivo

Asc•− and H2O2 were generated in vivo upon i.v Vit-C administration of around 0.5 g/kg of body weight and that the generation was Vit-C-dose reliant

free irons, especially Fe(II), increase Vit-C autoxidation, leading to H2O2 production

iron metabolism is altered in malignancies

increase in the expression of various iron-intake pathways or the downregulation of iron exporter proteins and storage pathways

Fe(II) ion in breast cancer cells is almost double that in normal breast tissues

macrophages in the cancer microenvironment have been revealed to increase iron shedding

Advanced breast tumor patients had substantially greater Fe(II) levels in their blood than the control groups without the disease

increased the amount of LIP inside the cells through transferrin receptor (TfR)

Warburg effect, or metabolic reprogramming,

Warburg effect is aided by KRAS or BRAF mutations

Vit-C is supplied, it oxidizes to DHA, and then is readily transported by GLUT-1 in mutant cells of KRAS or BRAF competing with glucose [46]. DHA is quickly converted into ascorbate inside the cell by NADPH and GSH [46,107]. This decrease reduces the concentration of cytosolic antioxidants and raises the intracellular ROS amounts

increased ROS inactivates glyceraldehyde 3-phosphate dehydrogenase (GAPDH)

ROS activates poly (ADP-ribose) polymerase (PARP), which depletes NAD+ (a critical co-factor of GAPDH); thus, further reducing the GAPDH associated with a multifaceted metabolic rewiring

Hindering GAPDH can result in an “energy crisis”, due to the decrease in ATP production

high-dose Vit-C recruited metabolites and increased the enzymatic activity in the pentose phosphate pathway (PPP), blocked the tri-carboxylic acid (TCA) cycle, and increased oxygen uptake, disrupting the intracellular metabolic balance and resulting in irreversible cell death, due to an energy crisis

mega-dose Vit-C influences energy metabolism by producing tremendous amounts of H2O2

Due to its great volatility at neutral pH [76], bolus therapy with mega-dose DHA has only transitory effects on tumor cells, both in vitro and in vivo.

the concentration of EPA in the brain is negligible (77–80), suggesting that EPA plays a limited role in mediating the beneficial effects of LCPUFA supplementation on mTBI pathology

the current state of the science regarding LCPUFA supplementation for the treatment of concussion is based primarily on animal models

there is evidence that the amount of DHA in brain tissue is decreased after mTBI (65, 66), suggesting an elevated need for DHA in mTBI recovery.

the well-established role of DHA in supporting the structure and function of the brain throughout the lifespan (26, 27, 46, 47, 53) provides encouragement that LCPUFAs may also prove beneficial in the context of concussion recovery.

no therapies are currently available to aid the recovery from this injury

Previously discussed reports outlining the use of ω-3 FAs in the recovery from severe TBIs (reviewed in Ref. 92) described the use of very-high doses of LCPUFAs (16.2 g/d EPA plus DHA) in the recovery of these patients

Within the context of mTBIs/concussions, translating a DHA intake used in several rat studies of mTBI recovery (40 mg ⋅ kg−1 ⋅ d−1 DHA) (57, 63, 64) using body surface area conversion methods (93) amounts to an estimated human intake of 387 mg/d DHA

Multiple inflammatory inputs contribute to metabolic dysfunction, including increases in circulating cytokines (10), decreases in protective factors (e.g., adiponectin; ref. 11), and communication between inflammatory and metabolic cells

adipose tissue macrophage (ATM)

Physiologic enhancement of the M2 pathways (e.g., eosinophil recruitment in parasitic infection) also appears to be capable of reducing metainflammation and improving insulin sensitivity (27).

increasing adiposity results in a shift in the inflammatory profile of ATMs as a whole from an M2 state to one in which classical M1 proinflammatory signals predominate (21–23).

The M2 activation state is intrinsically linked to the activity of PPARδ and PPARγ

well-known regulators of lipid metabolism and mitochondrial activity

Independent of obesity, hypothalamic inflammation can impair insulin release from β cells, impair peripheral insulin action, and potentiate hypertension (63–65).

inflammation in pancreatic islets can reduce insulin secretion and trigger β cell apoptosis leading to decreased islet mass, critical events in the progression to diabetes (33, 34)

Since an estimated excess of 20–30 million macrophages accumulate with each kilogram of excess fat in humans, one could argue that increased adipose tissue mass is de facto a state of increased inflammatory mass

JNK, TLR4, ER stress)

NAFLD is associated with an increase in M1/Th1 cytokines and quantitative increases in immune cells

Upon stimulation by LPS and IFN-γ, macrophages assume a classical proinflammatory activation state (M1) that generates bactericidal or Th1 responses typically associated with obesity

DIO, metabolites such as diacylglycerols and ceramides accumulate in the hypothalamus and induce leptin and insulin resistance in the CNS (58, 59)

saturated FAs, which activate neuronal JNK and NF-κB signaling pathways with direct effects on leptin and insulin signaling (60)

Lipid infusion and a high-fat diet (HFD) activate hypothalamic inflammatory signaling pathways, resulting in increased food intake and nutrient storage (57)

Maternal obesity is associated with endotoxemia and ATM accumulation that may affect the developing fetus (73)

Placental inflammation is a characteristic of maternal obesity

a risk factor for obesity in offspring, and involves inflammatory macrophage infiltration that can alter the maternal-fetal circulation (74

Of these PRRs, TLR4 has received the most attention, as this receptor can be activated by free FAs to generate proinflammatory signals and activate NF-κB

Nod-like receptor (NLR) family of PRRs

ceramides and sphingolipids

The adipokine adiponectin has long been recognized to have positive benefits on multiple cell types to promote insulin sensitivity and deactivate proinflammatory pathways.

adiponectin stimulates ceramidase activity and modulates the balance between ceramides and sphingosine-1-phosphate

Inhibition of ceramide production blocks the ability of saturated FAs to induce insulin resistance (101)

NF-κB, obesity also activates JNK in insulin-responsive tissues

kisspeptin has emerged as one of the most potent secretagogues of GNRH release

Consistent with the hypothesis that obesity-mediated inhibition of kisspeptin signalling contributes to the suppression of the HPT axis, infusion of a bioactive kisspeptin fragment has been recently shown to robustly increase LH pulsatility, LH levels and circulating testosterone in hypotestosteronaemic men with type 2 diabetes

Figure 4

Interestingly, a recent 16-week study of experimentally induced hypogonadism in healthy men with graded testosterone add-back either with or without concomitant aromatase inhibitor treatment has in fact suggested that low oestradiol (but not low testosterone) may be responsible for the hypogonadism-associated increase in total body and intra-abdominal fat mass

A smaller study with a similar experimental design found that acute testosterone withdrawal reduced insulin sensitivity independent of body weight, whereas oestradiol withdrawal had no effects

Obesity and dysglycaemia and associated comorbidities such as obstructive sleep apnoea (Hoyos et al. 2012b) are important contributors to the suppression of the HPT axis

This is supported by observational studies showing that weight gain and development of diabetes accelerate the age-related decline in testosterone

Weight loss can reactivate the hypothalamic–pituitary–testicular axis

The hypothalamic–pituitary–testicular axis remains responsive to treatment with aromatase inhibitors or selective oestrogen receptor modulators in obese men