Cisplatin and 5-FU or CAP (cisplatin, doxorubicin, and cyclophosphamide) regimens can be used for combination chemotherapy
patients with advanced salivary gland malignancy treated with the CAP regimen achieved partial response (PR) or stable disease (SD) rates of 67% (8 out of 12 patients)
Agents commonly given as monotherapy for treating ACC are cisplatin, mitoxantrone, epirubicin, vinorelbine, paclitaxel, and gemcitabine. However, few of these agents have shown efficacy
single agent mitoxantrone or vinorelbine were recommended as reasonable choices
ACC is subdivided into 3 histological groups based on solid components of the tumor including cribriform, tubular, and solid
Cribriform and tubular ACCs usually exhibit a more indolent course, whereas the solid subtype is associated with worse prognosis
ACC consists of two different cell types: inner luminal epithelial cells and outer myoepithelial cells
epithelial cells express c-kit, cox-2 and Bcl-2
myoepithelial cells express EGFR and MYB
a balanced translocation of the v-myb avian myeloblastosis viral oncogene homolog-nuclear factor I/B (MYB-NFIB) is considered to be a signature molecular event of ACC oncogenesis
As a transcription factor, MYB is known to modulate multiple genetic downstream targets involved in oncogenesis, such as cox-2, c-kit, Bcl-2 and BclX
Various signaling cascades are essential for cancer cells to survive and grow. The PI3K/Akt/mTOR pathway is one of them
This pathway regulates cell survival and growth and is upregulated in many cancers
Mutations in genes associated with DNA repair are frequently found in familial cancer syndromes, such as hereditary breast-ovarian cancer syndrome (HBOC), hereditary non-polyposis colorectal cancer (HNPCC, also called Lynch syndrome) and Li-Fraumeni syndrome [30, 31]. These mutations were also reported in non-hereditary cancers
70% of ACC samples (58 of 84) were found to have genetic alterations in the MYB/MYC pathway, indicating that changes in this pathway are crucial in ACC pathogenesis
The second most frequently mutated pathway was involved in chromatin remodeling (epigenetic modification), a pathway that includes multiple histone related proteins, and was altered in 44% of samples
C-kit
VEGF, iNOS and NF-κB were noted to be highly expressed in ACC cells as compared to normal salivary gland cells
members of the SOX family, such as SOX 4 and SOX10, are overexpressed in ACC
FABP7 (Fatty acid binding protein 7) and AQP1 (Aquaporin 1) tend to be overexpressed in ACC cell lines
considerable variability in HER2 overexpression ranging from 0–58% in patients with ACC
the study with cetuximab and concurrent chemoradiation or chemotherapy showed the highest ORR (total 43%, 9.5% CR and 33% PR), but this regimen was only given to the EGFR positive patients
Cancer immunotherapy can be classified into 3 major groups. Active immunization using anti-tumor vaccines to induce and recruit T cells, passive immunization based on monoclonal antibodies, and adoptive cell transfer to expand tumor-reactive autologous T cells ex vivo and then reintroduce these cells into the same individual
LAK cells showed cytotoxicity against ACC cells
cytokine-induced cell apoptosis and the cytotoxic effect of the LAK cells contributed to tumor regression
molecular finding of the MYB-NFIB fusion gene has the greatest potential to target what appears to be a fundamental event in disease pathogenesis
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
The avermectins are known to possess pronounced antitumor activity
Over the past few years, there have been steadily increasing reports that ivermectin may have varying uses as an anti-cancer agent, as it has been shown to exhibit both anti-cancer and anti-cancer stem cell properties
In human ovarian cancer and NF2 tumor cell lines, high-dose ivermectin inactivates protein kinase PAK1 and blocks PAK1-dependent growth
PAK1 is essential for the growth of more than 70% of all human cancers, including breast, prostate, pancreatic, colon, gastric, lung, cervical and thyroid cancers, as well as hepatoma, glioma, melanoma, multiple myeloma and for neurofibromatosis tumors
Ivermectin suppresses breast cancer by activating cytostatic autophagy, disrupting cellular signaling in the process, probably by reducing PAK1 expression
Cancer stem cells are a key factor in cancer cells developing resistance to chemotherapies and these results indicate that a combination of chemotherapy agents plus ivermectin could potentially target and kill cancer stem cells, a paramount goal in overcoming cancer
Triple-negative breast cancers, which lack estrogen, progesterone and HER2 receptors, account for 10–20% of breast cancers and are associated with poor prognosis
Ivermectin addition led to transcriptional modulation of genes associated with epithelial–mesenchymal transition and maintenance of a cancer stem cell phenotype in triple-negative breast cancers cells, resulting in impairment of clonogenic self-renewal in vitro and inhibition of tumor growth and metastasis in vivo
Ivermectin-induced cytostatic autophagy also leads to suppression of tumor growth in breast cancer xenografts, causing researchers to believe there is scope for using ivermectin to inhibit breast cancer cell proliferation and that the drug is a potential treatment for breast cancer
ivermectin synergizes with the chemotherapy agents cytarabine and daunorubicin to induce cell death in leukemia cells
Ivermectin inhibits proliferation and increases apoptosis of various human cancers
Activation of WNT-TCF signaling is implicated in multiple diseases, including cancers of the lungs and intestine,
A new screening system has found that ivermectin inhibits the expression of WNT-TCF targets
It represses the levels of C-terminal β-catenin phosphoforms and of cyclin D1 in an okadaic acid-sensitive manner, indicating its action involves protein phosphatases
In vivo, ivermectin selectively inhibits TCF-dependent, but not TCF-independent, xenograft growth without side effects
ivermectin has an exemplary safety record, it could swiftly become a useful tool as a WNT-TCF pathway response blocker to treat WNT-TCF-dependent diseases, encompassing multiple cancers.117
related to
intracellular hydrogen peroxide generation
only be obtained by
intravenous administration of AA
Preferentially kills neoplastic cells
Is virtually non-toxic at any dosage
Does not suppress the immune system, unlike most chemotherapy
agents
Increases animal and human resistance to infectious agents by
enhancing lymphocyte blastogenesis, enhancing cellular immunity,
strengthening the extracellular matrix, and enhancing bactericidal
activity of neutrophils and modulation of complement protein
Strengthens the structural integrity of the extracellular matrix
which is responsible for stromal resistance to malignant invasiveness
1969, researchers at the NCI reported AA was highly toxic to Ehrlich
ascites cells in vitro
In 1977, Bram et al reported preferential AA
toxicity for several malignant melanoma cell lines, including four
human-derived lines
Noto et al reported that AA plus vitamin K3
had growth inhibiting action against three human tumor cell lines at
non-toxic levels
Metabolites of AA have also shown antitumor activity in
vitro
The AA begins to reduce cell proliferation in the tumor cell
line at the lowest concentration, 1.76 mg/dl, and is completely cytotoxic to
the cells at 7.04 mg/dl
the normal cells grew at an enhanced rate at the low dosages (1.76
and 3.52 mg/dl)
preferential toxicity of AA for tumor
cells. >95% toxicity to human endometrial adenocarcinoma and pancreatic
tumor cells (ATCC AN3-CA and MIA PaCa-2) occurred at 20 and 30 mg/dl,
respectively.
No toxicity or inhibition was demonstrated in the normal,
human skin fibroblasts (ATCC CCD 25SK) even at the highest concentration of
50 mg/dl.
the use of very high-dose intravenous AA for the treatment of
cancer was proposed as early as 1971
Cameron and Pauling have published
extensive suggestive evidence for prolonged life in terminal cancer patients
orally supplemented (with and without initial intravenous AA therapy) with
10 g/day of AA
AA, plasma levels during infusion were not monitored,
the long-term, oral dosage used in those experiments (10 g/day),
while substantial and capable of producing immunostimulatory and
extracellular matrix modulation effects, was not high enough to achieve
plasma concentrations that are generally cytotoxic to tumor cells in
culture
This low cytotoxic level of AA is exceedingly rare
5 — 40 mg/dl of AA is required in vitro to kill 100% of tumor
cells within 3 days. The 100% kill levels of 30 mg/dl for the endometrial
carcinoma cells and 40 mg/dl for the pancreatic carcinoma cells in Figure 2
are typical
normal range (95% range) of 0.39-1.13 mg/dl
1 h after beginning his first 8-h infusion of 115 g AA (Merit
Pharmaceuticals, Los Angeles, CA), the plasma AA was 3.7 mg/dl and at 5 h
was 19 mg/dl. During his fourth 8-h infusion, 8 days later, the 1 h plasma
level was 158 mg/dl and 5 h was 185 mg/dl
plasma levels of over 100 mg/dl have been maintained in 3
patients for more than 5 h using continuous intravenous infusion
In rare instances of patients with widely disseminated
and rapidly proliferating tumors, intravenous AA administration (10 — 45
g/day) precipitated widespread tumor hemorrhage and necrosis, resulting in
death
Although the outcomes were disastrous in these cases, they are
similar to the description of tumor-necrosis-factor-induced hemorrhage and
necrosis in mice (52) and seem to demonstrate the ability of AA to kill
tumor cells in vivo.
toxic effects of AA on one normal cell line were observed at 58.36 mg/dl and
the lack of side effects in patients maintaining >100 mg/dl plasma levels
Although it is very rare, tumor necrosis, hemorrhage, and subsequent
death should be the highest priority concern for the safety of intravenous
AA for cancer patients.
Klenner,
who reported no ill effects of dosages as high as 150 g intravenously over a
24-h period
Cathcart (55) who
describes no ill effects with doses of up to 200 g/d in patients with
various pathological conditions
following circumstances: renal
insufficiency, chronic hemodialysis patients, unusual forms of iron
overload, and oxalate stone formers
Screening for red cell glucose-6-phosphate
dehydrogenase deficiency, which can give rise to hemolysis of red blood
cells under oxidative stress (57), should also be performed
any cancer therapy should be started at a low dosage to ensure
that tumor hemorrhage does not occur.
patient is orally supplementing between infusions
a scorbutic rebound effect can be
avoided with oral supplementation. Because of the possibility of a rebound
effect, measurement of plasma levels during the periods between infusions
should be performed to ensure that no such effect takes place
Every effort
should be made to monitor plasma AA levels when a patient discontinues
intravenous AA therapy.
testosterone therapy has tremendous cardiovascular benefit in men with low T. The key here is physiologic replacement of Testosterone. Testosterone is a vasodilator and anti-inflammatory agent in men with low T. Testosterone therapy improves cardiac function in those with DHF and angina. Testosterone is found to be a Ca++ channel blocker--anyone say hypertension treatment?
IP-facial care product line has AQUAGOLD from Phiten's unique AquaMetal Technology known to strengthen the immune system, enhance the absorption of nutrients, regenerate tissues, & improve circulation. Above all, Gold have been regarded as a powerful anti-aging agent.
In catabolic states, such as in burn injuries, anabolic steroids such as a synthetic anabolic agent (oxandrolone) improves recovery. This could be easily extrapolated to androgens in general.
reducing oxidative stress with powerful antioxidants, is an important strategy for cancer prevention, as it would suppress one of the key early initiating steps where DNA damage and tumor-stroma metabolic-coupling begins. This would prevent cancer cells from acting as metabolic “parasites
Oxidative stress in cancer-associated fibroblasts triggers autophagy and mitophagy, resulting in compartmentalized cellular catabolism, loss of mitochondrial function, and the onset of aerobic glycolysis, in the tumor stroma. As such, cancer-associated fibroblasts produce high-energy nutrients (such as lactate and ketones) that fuel mitochondrial biogenesis and oxidative metabolism in cancer cells. We have termed this new energy-transfer mechanism the “reverse Warburg effect.
Then, oxidative stress, in cancer-associated fibroblasts, triggers the activation of two main transcription factors, NFκB and HIF-1α, leading to the onset of inflammation, autophagy, mitophagy and aerobic glycolysis in the tumor microenvironment
oxidative stress and ROS, produced in cancer-associated fibroblasts, has a “bystander effect” on adjacent cancer cells, leading to DNA damage, genomic instability and aneuploidy, which appears to be driving tumor-stroma co-evolution
tumor cells produce and secrete hydrogen peroxide, thereby “fertilizing” the tumor microenvironment and driving the “reverse Warburg effect.”
This type of stromal metabolism then produces high-energy nutrients (lactate, ketones and glutamine), as well as recycled chemical building blocks (nucleotides, amino acids, fatty acids), to literally “feed” cancer cells
loss of stromal caveolin (Cav-1) is sufficient to drive mitochondrial dysfunction with increased glucose uptake in fibroblasts, mimicking the glycolytic phenotype of cancer-associated fibroblasts.
oxidative stress initiated in tumor cells is transferred to cancer-associated fibroblasts.
Then, cancer-associated fibroblasts show quantitative reductions in mitochondrial activity and compensatory increases in glucose uptake, as well as high ROS production
These findings may explain the prognostic value of a loss of stromal Cav-1 as a marker of a “lethal” tumor microenvironment
Interruption of this process, by addition of catalase (an enzyme that detoxifies hydrogen peroxide) to the tissue culture media, blocks ROS activity in cancer cells and leads to apoptotic cell death in cancer cells
our results may also explain the “field effect” in cancer biology,5 as hydrogen peroxide secreted by cancer cells, and the propagation of ROS production, from cancer cells to fibroblasts, would create an increasing “mutagenic field” of ROS production, due to the resulting DNA damage
aerobic glycolysis takes place in cancer-associated fibroblasts, rather than in tumor cells, as previously suspected.
In this new paradigm, cancer cells induce oxidative stress in neighboring cancer-associated fibroblasts
cancer-associated fibroblasts have the largest increases in glucose uptake
cancer cells secrete hydrogen peroxide, which induces ROS production in cancer-associated fibroblasts
Then, oxidative stress in cancer-associated fibroblast leads to decreases in functional mitochondrial activity, and a corresponding increase in glucose uptake, to fuel aerobic glycolysis
cancer cells show significant increases in mitochondrial activity, and decreases in glucose uptake
fibroblasts and cancer cells in co-culture become metabolically coupled, resulting in the development of a “symbiotic” or “parasitic” relationship.
cancer-associated fibroblasts undergo aerobic glycolysis (producing lactate), while cancer cells use oxidative mitochondrial metabolism.
We have previously shown that oxidative stress in cancer-associated fibroblasts drives a loss of stromal Cav-1, due to its destruction via autophagy/lysosomal degradation
a loss of stromal Cav-1 is sufficient to induce further oxidative stress, DNA damage and autophagy, essentially mimicking pseudo-hypoxia and driving mitochondrial dysfunction
loss of stromal Cav-1 is a powerful biomarker for identifying breast cancer patients with early tumor recurrence, lymph-node metastasis, drug-resistance and poor clinical outcome
this type of metabolism (aerobic glycolysis and autophagy in the tumor stroma) is characteristic of a lethal tumor micro-environment, as it fuels anabolic growth in cancer cells, via the production of high-energy nutrients (such as lactate, ketones and glutamine) and other chemical building blocks
the upstream tumor-initiating event appears to be the secretion of hydrogen peroxide
one such enzymatically-active protein anti-oxidant that may be of therapeutic use is catalase, as it detoxifies hydrogen peroxide to water
numerous studies show that “catalase therapy” in pre-clinical animal models is indeed sufficient to almost completely block tumor recurrence and metastasis
by eliminating oxidative stress in cancer cells and the tumor microenvironment,55 we may be able to effectively cut off the tumor's fuel supply, by blocking stromal autophagy and aerobic glycolysis
breast cancer patients show systemic evidence of increased oxidative stress and a decreased anti-oxidant defense, which increases with aging and tumor progression.68–70 Chemotherapy and radiation therapy then promote further oxidative stress.69 Unfortunately, “sub-lethal” doses of oxidative stress during cancer therapy may contribute to tumor recurrence and metastasis, via the activation of myofibroblasts.
a loss of stromal Cav-1 is associated with the increased expression of gene profiles associated with normal aging, oxidative stress, DNA damage, HIF1/hypoxia, NFκB/inflammation, glycolysis and mitochondrial dysfunction
cancer-associated fibroblasts show the largest increases in glucose uptake, while cancer cells show corresponding decreases in glucose uptake, under identical co-culture conditions
Thus, increased PET glucose avidity may actually be a surrogate marker for a loss of stromal Cav-1 in human tumors, allowing the rapid detection of a lethal tumor microenvironment.
it appears that astrocytes are actually the cell type responsible for the glucose avidity.
In the brain, astrocytes are glycolytic and undergo aerobic glycolysis. Thus, astrocytes take up and metabolically process glucose to lactate.7
Then, lactate is secreted via a mono-carboxylate transporter, namely MCT4. As a consequence, neurons use lactate as their preferred energy substrate
both astrocytes and cancer-associated fibroblasts express MCT4 (which extrudes lactate) and MCT4 is upregulated by oxidative stress in stromal fibroblasts.34
In accordance with the idea that cancer-associated fibroblasts take up the bulk of glucose, PET glucose avidity is also now routinely used to measure the extent of fibrosis in a number of human diseases, including interstitial pulmonary fibrosis, postsurgical scars, keloids, arthritis and a variety of collagen-vascular diseases.
PET glucose avidity and elevated serum inflammatory markers both correlate with poor prognosis in breast cancers.
PET signal over-estimates the actual anatomical size of the tumor, consistent with the idea that PET glucose avidity is really measuring fibrosis and inflammation in the tumor microenvironment.
human breast and lung cancer patients can be positively identified by examining their exhaled breath for the presence of hydrogen peroxide.
tumor cell production of hydrogen peroxide drives NFκB-activation in adjacent normal cells in culture6 and during metastasis,103 directly implicating the use of antioxidants, NFκB-inhibitors and anti-inflammatory agents, in the treatment of aggressive human cancers.
Anemia has also been identified as an adverse prognostic factor
mild (10 g/dl—normal),
moderate (8–10 g/dl), severe (6.5–8 g/dl) and life threatening (<6.5 g/dl or unstable patient) anemia
anemia in cancer patients is often multifactorial.
Cancer itself can directly cause or exacerbate anemia either by suppressing hematopoiesis through bone marrow infiltration
or production of cytokines that lead to iron sequestration, or by reduced red blood cell production
in inflammatory anemia, iron deficiency should be defined by a low transferrin saturation
of <20%, ferritin levels of <100 ng/ml and a low reticulocyte hemoglobin concentration of <32 pg
anemia to thrombocytosis, as commonly
seen in cancer patients
TNF-α inhibits hemoglobin production
treatment
itself may be a major cause of anemia
Other cytokines, such as interleukin-6 (IL-6), IL-1 and interferon-γ, have also been shown to inhibit erythroid precursors
in vitro [9], albeit to a lesser extent
In inflammation, from whatever cause, IL-6 induces the liver to produce hepcidin. Hepcidin decreases iron absorption from
the bowel and blocks iron utilization in the bone marrow
Numerous in vitro studies have illustrated the central role of TNF-α in the pathogenesis of anemia
nephrotoxic effects of particular cytotoxic agents such as platinum salts can also lead to the persistence
of anemia through reduced Epo production by the kidney
Currently two options are at the disposal of the clinician for the treatment of anemia in cancer patients: transfusion of
packed red blood cells and the use of erythropoiesis-stimulating agents (ESAs)
The goal of the treatment is to relieve the
symptoms of anemia such as fatigue and dyspnea.
Transfusion of 1 unit of packed red blood cells has been estimated to result
in an increase in the hemoglobin level of 1 g/dl in a normal-sized adult
a higher mortality rate in patients receiving
ESA treatment
Recent concerns regarding the risk of thromboembolism in patients treated with ESA have been corroborated by the meta-analyses
conducted by Tonnelli and Bennett
Great review of anemia in Cancer:
1) blood loss
2) increased RBC loss
3) decreased RBC production
Cancer infiltration of marrow can reduce hematopoiesis. Inflammatory cytokines can reduce hematopoiesis. Inflammatory cytokines can block Fe absorption. Chemo and radiation can cause anemia--particularily platinum based therapies.
early colon cancers commonly display loss of function of the tumor suppressor Adenomatous polyposis coli (APC), a key component of the β-CATENIN destruction complex
Other cancers also show an active canonical WNT pathway; these include carcinomas of the lung, stomach, cervix, endometrium, and lung as well as melanomas and gliomas
In normal embryogenesis and homeostasis, the canonical WNT pathway is activated by secreted WNT ligands produced in highly controlled context-dependent manners and in precise amounts. WNT activity is transduced in the cytoplasm, inactivates the APC destruction complex, and results in the translocation of activate β-CATENIN to the nucleus, where it cooperates with DNA-binding TCF/LEF factors to regulate WNT-TCF targets and the ensuing genomic response
beyond the loss of activity of the APC destruction complex, for instance throughAPC mutation, phosphorylation of β-CATENIN at C-terminal sites is required for the full activation of WNT-TCF signaling and the ensuing WNT-TCF responses in cancer.
The WNT-TCF response blockade that we describe for low doses of Ivermectin suggests an action independent to the deregulation of chloride channels
involve the repression of the levels of C-terminally phosphorylated β-CATENIN forms and of CYCLIN D1, a critical target that is an oncogene and positive cell cycle regulator.
the Avermectin single-molecule derivative Selamectin, a drug widely used in veterinarian medicine (Nolan & Lok, 2012), is ten times more potent acting in the nanomolar range
Ivermectin also diminished the protein levels of CYCLIN D1, a direct TCF target and oncogene, in both HT29 and H358 tumor cells
Activated Caspase3 was used as a marker of apoptosis by immunohistochemistry 48 h after drug treatment. Selamectin and Ivermectin induced up to a sevenfold increase in the number of activated Caspase3+ cells in two primary (CC14 and CC36) and two cell line (DLD1 and Ls174T) colon cancer cell types (Fig(Fig2C).2C). All changes were significative
The strong downregulation of the expression of the intestinal stem cell genesASCL2 andLGR5 (van der Flieret al, 2009; Scheperset al, 2012; Zhuet al, 2012b) by Ivermectin and Selamectin (Fig(Fig2D)2D) raised the possibility that these drugs could affect WNT-TCF-dependent colon cancer stem cell behavior
Pre-established H358 tumors responded to Ivermectin showing a ˜ 50% repression of growth
Ivermectin hasin vivo efficacy against human colon cancer xenografts sensitive to TCF inhibition with no discernable side effects
Ivermectin (Campbellet al, 1983), an off-patent drug approved for human use, and related macrocyclic lactones, have WNT-TCF pathway response blocking and anti-cancer activities
these drugs block WNT-TCF pathway responses, likely acting at the level of β-CATENIN/TCF function, affecting β-CATENIN phosphorylation status.
anti-WNT-TCF activities of Ivermectin and Selamectin
Ivermectin has a well-known anti-parasitic activity mediated via the deregulation of chloride channels, leading to paralysis and death (Hibbs & Gouaux, 2011; Lynagh & Lynch, 2012). The same mode of action has been suggested to underlie the toxicity of Ivermectin for liquid tumor cells and the potentiation or sensitization effect of Avermectin B1 on classical chemotherapeutics
the specificity of the blockade of WNT-TCF responses we document, at low micromolar doses for Ivermectin and low nanomolar doses for Selamectin, indicate that the blockade of WNT-TCF responses and chloride channel deregulation are distinct modes of action
What is key then is to find a dose and a context where the use of Ivermectin has beneficial effects in patients, paralleling our results with xenografts in mice.
Cell toxicity appears at doses greater (> 10 μM for 12 h or longer or > 5 μM for 48 h or longer for Ivermectin) than those required to block TCF responses and induce apoptosis.
Our data point to a repression of WNT-β-CATENIN/TCF transcriptional responses by Ivermectin, Selamectin and related macrocylic lactones.
(i) The ability of Avermectin B1 to inhibit the activation of WNT-TCF reporter activity by N-terminal mutant (APC-insensitive) β-CATENIN as detected in our screen
(ii) The ability of Avermectin B1, Ivermectin, Doramectin, Moxidectin and Selamectin to parallel the modulation of WNT-TCF targets by dnTCF
(iii) The finding that the specific WNT-TCF response blockade by low doses of Ivermectin and Selamectin is reversed by constitutively active TCF
(iv) The repression of key C-terminal phospho-isoforms of β-CATENIN resulting in the repression of the TCF target and positive cell cycle regulator CYCLIN D1 by Ivermectin and Selamectin
(v) The specific inhibition ofin-vivo-TCF-dependent, but notin-vivo-TCF-independent cancer cells by Ivermectin in xenografts.
These results together with the reduction of the expression of the colon cancer stem cell markersASCL2 andLGR5 (e.g., Hirschet al, 2013; Ziskinet al, 2013) raise the possibility of an inhibitory effect of Ivermectin, Selamectin and related macrocyclic lactones on TCF-dependent cancer stem cells.
the capacity of cancer cells to form 3D spheroids in culture, as well as the growth of these, is also WNT-TCF-dependent (Kanwaret al, 2010) and they were also affected by Ivermectin treatment
If Ivermectin is specific, it should only block TCF-dependent tumor growth. Indeed, the sensitivity and insensitivity of DLD1 and CC14 xenografts to Ivermectin treatment, respectively, together with the desensitization to Ivermectin actionin vivo by constitutively active TCF provide evidence of the specificity of this drug to block an activated WNT-TCF pathway in human cancer.
Ivermectin has a good safety profile since onlyin-vivo-dnTCF-sensitive cancer xenografts are responsive to Ivermectin treatment, and we have not detected side effects in Ivermectin-treated mice at the doses used
previous work has shown that side effects from systemic treatments with clinically relevant doses in humans are rare (Yang, 2012), that birth defects were not observed after exposure of pregnant mothers (Pacquéet al, 1990) and that this drug does not cross the blood–brain barrier (Kokozet al, 1999). Similarly, only dogs with mutantABCB1 (MDR1) alleles leading to a broken blood–brain barrier show Ivermectin neurotoxicity (Mealeyet al, 2001; Orzechowskiet al, 2012)
Indications may include treatment for incurable β-CATENIN/TCF-dependent advanced and metastatic human tumors of the lung, colon, endometrium, and other organs.
Ivermectin, Selamectin, or related macrocyclic lactones could also serve as topical agents for WNT-TCF-dependent skin lesions and tumors such as basal cell carcinomas
they might also be useful as routine prophylactic agents, for instance against nascent TCF-dependent intestinal tumors in patients with familial polyposis and against nascent sporadic colon tumors in the general aging population
Ivermectin, a common anti-parasitic, found to inhibit WTF-TCF pathway and decrease c-terminal phosophorylaiton of Beta-CATENIN all resulting in increased aptosis and inhibition of cancer growth in colon cancer cell lines and lung cancer cell lines.
Accumulating evidence suggests that niclosamide targets multiple signaling pathways such as nuclear factor-kappaB (NF-kB), Wnt/β-catenin, and Notch, most of which are closely involved with cancer stem cell proliferation
The transcription factor NF-κB has been demonstrated to promote cancer growth, angiogenesis, escape from apoptosis, and tumorigenesis
NF-κB is sequestered in the cytosol of resting cells through binding the inhibitory subunit IκBα
Niclosamide blocked TNFα-induced IκBα phosphorylation, translocation of p65, and the expression of NF-κB-regulated genes
Niclosamide also inhibited the DNA binding of NF-κB to the promoter of its target genes
niclosamide has two independent effects: NF-kB activation and ROS elevation
The Wnt signaling pathway plays fundamental roles in directing tissue patterning in embryonic development, in maintaining tissue homeostasis in differentiated tissue, and in tumorigenesis
niclosamide is a potent inhibitor of the Wnt/β-catenin pathway
The Notch signaling pathway plays important roles in a variety of cellular processes such as proliferation, differentiation, apoptosis, cell fate decisions, and maintenance of stem cells
niclosamide potently suppresses the luciferase activity of a CBF-1-dependent reporter gene in both a dose-dependent and a time-dependent manners in K562 leukemia cells
niclosamide treatment abrogated the epidermal growth factor (EGF)-stimulated dimerization and nuclear translocation and transcriptional activity of Stat3, and induced cell growth inhibition and apoptosis in several types of cancer cells (e.g. Du145, Hela, A549) that exhibit relatively higher levels of Stat3 constitutive activation
niclosamide can rapidly increase autophagosome formation
niclosamide induced autophagy and inhibited mammalian target of rapamycin complex 1 (mTORC1)
Niclosamide has low toxicity in mammals (oral median lethal dose in rats >5000 mg/kg
Niclosamide is active against cancer cells such as AML and colorectal cancer cells, not only as a monotherapy but also as part of combination therapy, in which it has been found to be synergistic with frontline chemotherapeutic agents (e.g., oxaliplatin, cytarabine, etoposide, and daunorubicin)
Because niclosamide targets multiple signaling pathways (e.g., NF-κB, Wnt/β-catenin, and Notch), most of which are closely involved with cancer stem cells, it holds promise in eradicating cancer stem cells
Review article: common anti-parasitic medication, niclosamide, provides anti-proliferative effect in cancer stem cells (CSC), via inhibition of NF-kappaBeta, Wnt/B-catenin, Notch, ROS, mTORC1, and STAT2 pathways.
These eight distinct cancer types included: DCIS, breast (ER(+) and ER(-)), ovarian, prostate, lung, and pancreatic carcinomas, as well as melanoma and glioblastoma. Doxycycline was also effective in halting the propagation of primary cultures of CSCs from breast cancer patients, with advanced metastatic disease (isolated from ascites fluid and/or pleural effusions)
Doxycycline behaves as a strong radio-sensitizer, successfully overcoming radio-resistance in breast CSCs
cancer cells can indeed escape the effects of Doxycycline, by reverting to a purely glycolytic phenotype. Fortunately, the metabolic inflexibility conferred by this escape mechanism allows Doxycycline-resistant (DoxyR) CSCs to be more effectively targeted with many other metabolic inhibitors, including Vitamin C, which functionally blocks aerobic glycolysis
Vitamin C inhibits GAPDH (a glycolytic enzyme) and depletes the cellular pool of glutathione, resulting in high ROS production and oxidative stress
DoxyR CSCs are between 4- to 10-fold more susceptible to the effects of Vitamin C
Doxycycline and Vitamin C may represent a new synthetic lethal drug combination for eradicating CSCs, by ultimately targeting both mitochondrial and glycolytic metabolism
inhibiting their propagation in the range of 100 to 250 µM
metabolic flexibility in cancer cells allows them to escape therapeutic eradication, leading to chemo- and radio-resistance
used doxycycline to pharmacologically induce metabolic inflexibility in CSCs, by chronically inhibiting mitochondrial biogenesis
This treatment resulted in a purely glycolytic population of surviving cancer cells
DoxyR cells are mainly glycolytic
MCF7 cells survive and develop Doxycycline-resistance, by adopting a purely glycolytic phenotype
Cancer stem cells (CSCs) are thought to be the “root cause” of tumor recurrence, distant metastasis and therapy-resistance
the conserved evolutionary similarities between aerobic bacteria and mitochondria, certain classes of antibiotics inhibit mitochondrial protein translation, as an off-target side-effect
Vitamin C was more potent than 2-DG; it inhibited DoxyR CSC propagation by > 90% at 250 µM and 100% at 500 µM
IC-50
DoxyR CSCs are between 4- to 10-fold more sensitive to Vitamin C than control MCF7 CSCs
Berberine, which is a naturally occurring antibiotic that also behaves as an OXPHOS inhibitor
treatment with Berberine effectively inhibited the propagation of the DoxyR CSCs by > 50% at 1 µM and > 80% at 10 µM.
Doxycycline, a clinically approved antibiotic, induces metabolic stress in cancer cells. This allows the remaining cancer cells to be synchronized towards a purely glycolytic phenotype, driving a form of metabolic inflexibility
Doxycycline-driven aerobic glycolysis
new synthetic lethal strategy for eradicating CSCs, by employing i) Doxycycline (to target mitochondria) and ii) Vitamin C (to target glycolysis)
Doxycycline inhibits mitochondrial biogenesis and OXPHOS,
hibits glycolytic metabolism by targeting and inhibiting the enzyme GAPDH
CSCs act as the main promoter of tumor recurrence and patient relapse
a metabolic shift from oxidative to glycolytic metabolism represents an escape mechanism for breast cancer cells chronically-treated with a mitochondrial stressor like Doxycycline, as mitochondrial dys-function leads to a stronger dependence on glucose
Vitamin C has been demonstrated to selectively kill cancer cells in vitro and to inhibit tumor growth in experimental mouse models
many of these actions have been attributed to the ability of Vitamin C to act as a glycolysis inhibitor, by targeting GAPDH and depleting the NAD pool
here we show that DoxyR CSCs are more vulnerable to the inhibitory effects of Vitamin C, at 4- to 10-fold lower concentrations, between 100 to 250 μM
concurrent use of Vitamin C, with standard chemotherapy, reduces tumor recurrence and patient mortality
after oral administration, Vitamin C plasma levels reach concentrations of ~70-220 μM
intravenous administration results in 30- to 70- fold higher plasma concentrations of Vitamin C
pro-oxidant activity results from Vitamin C’s action on metal ions, which generates free radicals and hydrogen peroxide, and is associated with cell toxicity
it has been shown that high-dose Vitamin C is more cytotoxic to cancer cells than to normal cells
This selectivity appears to be due to the higher catalase content observed in normal cells (~10-100 fold greater), as compared to tumor cells. Hence, Vitamin C may be regarded as a safe agent that selectively targets cancer cells
the concurrent use of Doxycycline and Vitamin C, in the context of this infectious disease, appeared to be highly synergistic in patients
Goc et al., 2016, showed that Doxycycline is synergistic in vitro with certain phytochemicals and micronutrients, including Vitamin C, in the in vitro killing of the vegetative spirochete form of Borrelia spp., the causative agent underlying Lyme disease
Doxycycline, an FDA-approved antibiotic, behaves as an inhibitor of mitochondrial protein translation
CSCs successfully escape from the anti-mitochondrial effects of Doxycycline, by assuming a purely glycolytic phenotype. Therefore, DoxyR CSCs are then more susceptible to other metabolic perturbations, because of their metabolic inflexibility
pharmacokinetic data indicate that intravenous administration of ascorbate can bypass this tight control resulting in highly elevated plasma levels
ascorbate readily oxidizes to produce H2O2, pharmacological ascorbate has been proposed as a prodrug for the delivery of H2O2 to tumors
Ascorbate is an excellent reducing agent and readily undergoes two consecutive, one-electron oxidations to form ascorbate radical (Asc•−) and dehydroascorbic acid (DHA)
Ascorbate oxidizes readily. The rate of oxidation is dependent on pH and is accelerated by catalytic metals
In near-neutral buffers with contaminating metals, the oxidation and subsequent loss of ascorbate can be very rapid
Ascorbate is required for maintaining iron in the ferrous state
In the presence of catalytic metal ions, ascorbate can also exert pro-oxidant effects
Ascorbate is an excellent one-electron reducing agent that can reduce ferric (Fe3+) to ferrous (Fe2+) iron, while being oxidized to ascorbate radical
In a classic Fenton reaction, Fe2+ reacts with H2O2 to generate Fe3+ and the very oxidizing hydroxyl radical
e presence of ascorbate can allow the recycling of Fe3+ back to Fe2+, which in turn will catalyze the formation of highly reactive oxidants from H2O2
Depending on concentrations, the effects of ascorbate on models of lipid peroxidation can be pro- or antioxidant
ferritin released enhanced pharmacologic ascorbate induced-cytotoxicity, indicating that ferritin with high iron-saturation could be a source of catalytic iron. Consistent with this, ascorbate has also been shown to be capable of releasing iron from cellular ferritin