ABSTRACT
In this work, we performed anti-proliferative assays for the compound N-(2-hydroxyphenyl)-2-propylpentanamide (HO-AAVPA) on breast cancer (BC) cells (MCF-7, SKBR3, and triple-negative BC (TNBC) MDA-MB-231 cells) to explore its pharmacological mechanism regarding the type of cell death associated with G protein-coupled estrogen receptor (GPER) expression. The results show that HO-AAVPA induces cell apoptosis at 5 h or 48 h in either estrogen-dependent (MCF-7) or -independent BC cells (SKBR3 and MDA-MB-231). At 5 h, the apoptosis rate for MCF-7 cells was 68.4% and that for MDA-MB-231 cells was 56.1%; at 48 h, that for SKBR3 was 61.6%, that for MCF-7 cells was 54.9%, and that for MDA-MB-231 (TNBC) was 43.1%. HO-AAVPA increased the S phase in MCF-7 cells and reduced the G2/M phase in MCF-7 and MDA-MB-231 cells. GPER expression decreased more than VPA in the presence of HO-AAVPA. In conclusion, the effects of HO-AAVPA on cell apoptosis could be modulated by epigenetic effects through a decrease in GPER expression.
Subject(s)
Apoptosis , Breast Neoplasms , Cell Cycle Checkpoints , Receptors, Estrogen , Receptors, G-Protein-Coupled , Humans , Apoptosis/drug effects , Receptors, G-Protein-Coupled/metabolism , Receptors, G-Protein-Coupled/genetics , Receptors, Estrogen/metabolism , Female , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Cell Cycle Checkpoints/drug effects , MCF-7 Cells , Cell Line, Tumor , Cell Proliferation/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Amides/pharmacology , Amides/chemistryABSTRACT
INTRODUCTION: The treatment of advanced cervical cancer is continuously developing. There is a critical need to explore new treatment options to improve cure rates and make treatment more affordable. Despite efforts in prevention, cervical cancer remains the fourth most common cancer worldwide in terms of both incidence and mortality. AREAS COVERED: This article offers an updated and critical analysis of angiogenesis inhibitors used in the treatment of advanced cervical cancer. It should be noted that this is not a systematic review. EXPERT OPINION: Bevacizumab is currently the primary antiangiogenic agent used alongside chemotherapy and has become the standard of care for advanced cervical cancer. However, there are still uncertainties regarding the molecular mechanisms and associations in cervical cancer that could help in optimizing the use of Bevacizumab. Factors such as cost, toxicity, and methodological issues in the GOG-240 trial must be considered.
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Drug repurposing of widely prescribed patent-off and cheap drugs may provide affordable drugs for cancer treatment. Nevertheless, many preclinical studies of cancer drug repurposing candidates use in vitro drug concentrations too high to have clinical relevance. Hence, preclinical studies must use clinically achievable drug concentrations. In this work, several FDA-approved cancer drugs are analyzed regarding the correlation between the drug inhibitory concentrations 50% (IC50) tested in cancer cell lines and their corresponding peak serum concentration (Cmax) and area under the curve (AUC) reported in clinical studies of these drugs. We found that for most targeted cancer drugs, the AUC and not the Cmax is closest to the IC50; therefore, we suggest that the initial testing of candidate drugs for repurposing could select the AUC pharmacokinetic parameter and not the Cmax as the translated drug concentration for in vitro testing. Nevertheless, this is a suggestion only as experimental evidence does not exist to prove this concept. Studies on this issue are required to advance in cancer drug repurposing.
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Lymphoma is a disease that affects countless lives each year. In order to combat this disease, researchers have been exploring the potential of DNMTi and HDACi drugs. These drugs target the cellular processes that contribute to lymphomagenesis and treatment resistance. Our research evaluated the effectiveness of a combination of two such drugs, hydralazine (DNMTi) and valproate (HDACi), in B-cell and T-cell lymphoma cell lines. Here we show that the combination of hydralazine and valproate decreased the viability of cells over time, leading to the arrest of cell-cycle and apoptosis in both B and T-cells. This combination of drugs proved to be synergistic, with each drug showing significant growth inhibition individually. Microarray analyses of HuT 78 and Raji cells showed that the combination of hydralazine and valproate resulted in the up-regulation of 562 and 850 genes, respectively, while down-regulating 152 and 650 genes. Several proapoptotic and cell cycle-related genes were found to be up-regulated. Notably, three and five of the ten most up-regulated genes in HuT 78 and Raji cells, respectively, were related to immune function. In summary, our study suggests that the combination of hydralazine and valproate is an effective treatment option for both B- and T-lymphomas. These findings are highly encouraging, and we urge further clinical evaluation to validate our research and potentially improve lymphoma treatment.
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BACKGROUND: The SLC5A8 gene is silenced in various types of cancer, including cervical cancer; we recently demonstrated that the SLC5A8 gene is also silenced in cervical cancer by hypermethylation of the CpG island in the gene promoter. This study aims to analyze whether SLC5A8 could be a tumor suppressor in cervical cancer. METHODS: After ectopic expressing SLC5A8 in the HeLa cell line, we evaluated its effects on cell behavior both in vitro and in vivo by Confocal immunofluorescence, cell proliferation, migration assays, and xenograft transplants. RESULTS: Overexpression of SLC5A8 in the HeLa cell line decreased its proliferation by arresting cancer cells in the G1 phase and inhibiting cellular migration. Furthermore, we observed that pyruvate increased the SLC5A8 effect, inducing S-phase arrest and inhibiting the entry into mitosis. SLC5A8 decreased tumor growth in xenograft transplants, significantly reducing the volume and tumor weight at 35 days of analysis. CONCLUSIONS: In summary, our results indicate that SLC5A8 has a role as a tumor suppressor in cervical cancer.
Subject(s)
Monocarboxylic Acid Transporters , Uterine Cervical Neoplasms , Female , Humans , Cell Line, Tumor , Genes, Tumor Suppressor , HeLa Cells , Monocarboxylic Acid Transporters/genetics , Pyruvic Acid , Uterine Cervical Neoplasms/genetics , AnimalsABSTRACT
INTRODUCTION: The pharmacological treatment of cancer has evolved from cytotoxic to molecular targeted therapy. The median survival gains of 124 drugs approved by the FDA from 2003 to 2021 is 2.8 months. Targeted therapy is based on the somatic mutation theory, which has some paradoxes and limitations. While efforts of targeted therapy must continue, we must study newer approaches that could advance therapy and affordability for patients. AREAS COVERED: This work briefly overviews how cancer therapy has evolved from cytotoxic chemotherapy to current molecular-targeted therapy. The limitations of the one-target, one-drug approach considering cancer as a robust system and the basis for multitargeting approach with polypharmacotherapy using repurposing drugs. EXPERT OPINION: Multitargeted polypharmacotherapy for cancer with repurposed drugs should be systematically investigated in preclinical and clinical studies. Remarkably, most of these proposed drugs already have a long history in the clinical setting, and their safety is known. In principle, the risk of their simultaneous administration should not be greater than that of a first-in-human phase I study as long as the protocol is developed with strict vigilance to detect early possible side effects from their potential interactions. Research on cancer therapy should go beyond the prevailing paradigm targeted therapy.
Subject(s)
Antineoplastic Agents , Drug Repositioning , Molecular Targeted Therapy , Neoplasms , Humans , Neoplasms/drug therapy , Neoplasms/pathology , Antineoplastic Agents/pharmacology , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/adverse effects , Animals , Survival Rate , Polypharmacology , Drug DevelopmentABSTRACT
One of the primary diseases that cause death worldwide is cancer. Cancer cells can be intrinsically resistant or acquire resistance to therapies and drugs used for cancer treatment through multiple mechanisms of action that favor cell survival and proliferation, becoming one of the leading causes of treatment failure against cancer. A promising strategy to overcome chemoresistance and radioresistance is the co-administration of anticancer agents and natural compounds with anticancer properties, such as the polyphenolic compound resveratrol (RSV). RSV has been reported to be able to sensitize cancer cells to chemotherapeutic agents and radiotherapy, promoting cancer cell death. This review describes the reported molecular mechanisms by which RSV sensitizes tumor cells to radiotherapy and chemotherapy treatment.
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Therapeutic repurposing emerged as an alternative to the traditional drug discovery and development model (DDD) of new molecular entities (NMEs). It was anticipated that by being faster, safer, and cheaper, the development would result in lower-cost drugs. As defined in this work, a repurposed cancer drug is one approved by a health regulatory authority against a non-cancer indication that then gains new approval for cancer. With this definition, only three drugs are repurposed for cancer: Bacillus Calmette-Guerin (BCG) vaccine (superficial bladder cancer, thalidomide [multiple myeloma], and propranolol [infantile hemangioma]). Each of these has a different history regarding price and affordability, and it is not yet possible to generalize the impact of drug repurposing on the final price to the patient. However, the development, including the price, does not differ significantly from an NME. For the end consumer, the product's price is unrelated to whether it followed the classical development or repurposing. Economic constraints for clinical development, and drug prescription biases for repurposing drugs, are barriers yet to be overcome. The affordability of cancer drugs is a complex issue that varies from country to country. Many alternatives for having affordable drugs have been put forward, however these measures have thus far failed and are, at best, palliative. There are no immediate solutions to the problem of access to cancer drugs. It is necessary to critically analyze the impact of the current drug development model and be creative in implementing new models that genuinely benefit society.
Subject(s)
Antineoplastic Agents , Urinary Bladder Neoplasms , Humans , Drug Repositioning , Motivation , Antineoplastic Agents/therapeutic use , Urinary Bladder Neoplasms/drug therapy , BCG Vaccine/therapeutic useABSTRACT
The master-key TP53 gene is a tumor suppressor that is mutated in more than 50% of human cancers. Some p53 mutants lose their tumor suppressor activity and acquire new oncogenic functions, known as a gain of function (GOF). Recent studies have shown that p53 mutants can exert oncogenic effects through specific miRNAs. We identified the differentially expressed miRNA profiles of the three most frequent p53 mutants (p53R273C, p53R248Q, and p53R175H) after their transfection into the Saos-2 cell line (null p53) as compared with p53WT transfected cells. The associations between these miRNAs and the signaling pathways in which they might participate were identified with miRPath Software V3.0. QRT-PCR was employed to validate the miRNA profiles. We observed that p53 mutants have an overall negative effect on miRNA expression. In the global expression profile of the human miRNome regulated by the p53R273C mutant, 72 miRNAs were underexpressed and 35 overexpressed; in the p53R175H miRNAs profile, our results showed the downregulation of 93 and upregulation of 10 miRNAs; and in the miRNAs expression profile regulated by the p53R248Q mutant, we found 167 decreased and 6 increased miRNAs compared with p53WT. However, we found overexpression of some miRNAs, like miR-182-5p, in association with processes such as cell migration and invasion. In addition, we explored whether the induction of cell migration and invasion by the p53R48Q mutant was dependent on miR-182-5p because we found overexpression of miR-182-5p, which is associated with processes such as cell migration and invasion. Inhibition of mutant p53R248Q and miR-182-5p increased FOXF2-MTSS1 levels and decreased cell migration and invasion. In summary, our results suggest that p53 mutants increase the expression of miR-182-5p, and this miRNA is necessary for the p53R248Q mutant to induce cell migration and invasion in a cancer cell model.
Subject(s)
Genes, p53 , MicroRNAs , Humans , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Cell Line, Tumor , Gain of Function Mutation , Cell Proliferation , MicroRNAs/metabolism , Neoplastic Processes , Forkhead Transcription Factors/metabolism , Microfilament Proteins/metabolism , Neoplasm Proteins/metabolismABSTRACT
BACKGROUND: Prostate cancer is the most frequently diagnosed malignancy in 112 countries and is the leading cause of death in eighteen. In addition to continuing research on prevention and early diagnosis, improving treatments and making them more affordable is imperative. In this sense, the therapeutic repurposing of low-cost and widely available drugs could reduce global mortality from this disease. The malignant metabolic phenotype is becoming increasingly important due to its therapeutic implications. Cancer generally is characterized by hyperactivation of glycolysis, glutaminolysis, and fatty acid synthesis. However, prostate cancer is particularly lipidic; it exhibits increased activity in the pathways for synthesizing fatty acids, cholesterol, and fatty acid oxidation (FAO). OBJECTIVE: Based on a literature review, we propose the PaSTe regimen (Pantoprazole, Simvastatin, Trimetazidine) as a metabolic therapy for prostate cancer. Pantoprazole and simvastatin inhibit the enzymes fatty acid synthase (FASN) and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), therefore, blocking the synthesis of fatty acids and cholesterol, respectively. In contrast, trimetazidine inhibits the enzyme 3-b-Ketoacyl-CoA thiolase (3-KAT), an enzyme that catalyzes the oxidation of fatty acids (FAO). It is known that the pharmacological or genetic depletion of any of these enzymes has antitumor effects in prostatic cancer. RESULTS: Based on this information, we hypothesize that the PaSTe regimen will have increased antitumor effects and may impede the metabolic reprogramming shift. Existing knowledge shows that enzyme inhibition occurs at molar concentrations achieved in plasma at standard doses of these drugs. CONCLUSION: We conclude that this regimen deserves to be preclinically evaluated because of its clinical potential for the treatment of prostate cancer.
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BACKGROUND: Worldwide, gastric cancer is ranked the fifth malignancy in incidence and the third malignancy in mortality. Gastric cancer causes an altered metabolism that can be therapeutically exploited. OBJECTIVE: The objective of this study is to provide an overview of the significant metabolic alterations caused by gastric cancer and propose a blockade. METHODS: A comprehensive and up-to-date review of descriptive and experimental publications on the metabolic alterations caused by gastric cancer and their blockade. This is not a systematic review. RESULTS: Gastric cancer causes high rates of glycolysis and glutaminolysis. There are increased rates of de novo fatty acid synthesis and cholesterol synthesis. Moreover, gastric cancer causes high rates of lipid turnover via fatty acid ß-oxidation. Preclinical data indicate that the individual blockade of these pathways via enzyme targeting leads to antitumor effects in vitro and in vivo. Nevertheless, there is no data on the simultaneous blockade of these five pathways, which is critical as tumors show metabolic flexibility in response to the availability of nutrients. This means tumors may activate alternate routes when one or more are inhibited. We hypothesize there is a need to simultaneously block them to avoid or decrease the metabolic flexibility that may lead to treatment resistance. CONCLUSION: There is a need to explore the preclinical efficacy and feasibility of combined metabolic therapy targeting the pathways of glucose, glutamine, fatty acid synthesis, cholesterol synthesis, and fatty acid oxidation. This may have therapeutical implications because we have clinically available drugs that target these pathways in gastric cancer.
Subject(s)
Stomach Neoplasms , Cholesterol , Fatty Acids/metabolism , Glutamine/metabolism , Glycolysis , Humans , Stomach Neoplasms/drug therapyABSTRACT
Cancer therapy advances have yet to impact global cancer mortality. One of the factors limiting mortality burden reduction is the high cost of cancer drugs. Cancer drug repurposing has already failed to meet expectations in terms of drug affordability. The three FDA-approved cancer drugs developed under repurposing: all-trans-retinoic acid, arsenic trioxide, and thalidomide do not differ in price from other drugs developed under the classical model. Though additional factors affect the whole process from inception to commercialization, the repurposing of widely used, commercially available, and cheap drugs may help. This work reviews the concept of the malignant metabolic phenotype and its exploitation by simultaneously blocking key metabolic processes altered in cancer. We elaborate on a combination called BAPST, which stands for the following drugs and pathways they inhibit: Benserazide (glycolysis), Apomorphine (glutaminolysis), Pantoprazole (Fatty-acid synthesis), Simvastatin (mevalonate pathway), and Trimetazidine (Fatty-acid oxidation). Their respective primary indications are: ⢠Parkinson's disease (benserazide and apomorphine). ⢠Peptic ulcer disease (pantoprazole). ⢠Hypercholesterolemia (simvastatin). ⢠Ischemic heart disease (trimetazidine). When used for their primary indication, the literature review on each of these drugs shows that they have a good safety profile and lack predicted pharmacokinetic interaction among them. Based on that, we propose that the BAPST regimen merits preclinical testing.
Subject(s)
Drug Combinations , Neoplasms , Apomorphine , Benserazide , Humans , Neoplasms/drug therapy , Neoplasms/pathology , Pantoprazole , Simvastatin , TrimetazidineABSTRACT
The high-risk human papillomavirus (HR-HPV) E7 oncoprotein appears to be a major determinant for cell immortalization and transformation altering critical processes such as cell proliferation, apoptosis, and immune response. This oncoprotein plays an essential role in cervical carcinogenesis, but other cofactors such as long-term use of hormonal contraceptives are necessary to modulate the risk of cervical cancer (CC). The role of HR-HPVs in the alteration of microRNA (miRNA) levels in persistent viral infections currently remains unclear. The aim of this study was to evaluate the miR-34a and miR-15b expression levels in the murine HPV16K14E7 (K14E7) transgenic model after chronic estrogen (E2) treatment and their involvement in CC. Interestingly, results showed that, although miR-34a expression is elevated by the HPVE7 oncogene, this expression was downregulated in the presence of both the E7 oncoprotein and chronic E2 in cervical carcinoma. On the other hand, miR-15b expression was upregulated along cervical carcinogenesis mainly by the effect of E2. These different changes in the expression levels of miR-34a and miR-15b along cervical carcinogenesis conduced to low apoptosis levels, high cell proliferation and finally, to cancerous cervical tissue development. In this work, we also determined the relative mRNA expression of Cyclin E2 (Ccne2), Cyclin A2 (Ccna2), and B cell lymphoma 2 (Bcl-2) (target genes of miR-34a and miR-15b); Sirtuin 1 (Sirt1), Cmyc, and Bax (miR-34a target genes); and p21/WAF1 (mir15b target gene) and the H-ras oncogene. Given the modifications in the expression levels of miR-34a and miR-15b during the development of cervical cancer, it will be useful to carry out further investigation to confirm them as molecular biomarkers of cancer.
Subject(s)
MicroRNAs , Uterine Cervical Neoplasms , Animals , Cell Proliferation , Cervix Uteri , Disease Models, Animal , Female , Humans , Mice , MicroRNAs/genetics , Uterine Cervical Neoplasms/geneticsABSTRACT
BACKGROUND: It has been reported that the oncoprotein E7 from human papillomavirus type 16 (HPV16-E7) can induce the excessive synthesis of centrosomes through the increase in the expression of PLK4, which is a transcriptional target of E2F1. On the other hand, it has been reported that increasing MPS1 protein stability can also generate an excessive synthesis of centrosomes. In this work, we analyzed the possible role of MPS1 in the amplification of centrosomes mediated by HPV16-E7. RESULTS: Employing qRT-PCR, Western Blot, and Immunofluorescence techniques, we found that E7 induces an increase in the MPS1 transcript and protein levels in the U2OS cell line, as well as protein stabilization. Besides, we observed that inhibiting the expression of MPS1 in E7 protein-expressing cells leads to a significant reduction in the number of centrosomes. CONCLUSIONS: These results indicate that the presence of the MPS1 protein is necessary for E7 protein to increase the number of centrosomes, and possible implications are discussed.
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The p53 roles have been largely described; among them, cell proliferation and apoptosis control are some of the best studied and understood. Interestingly, the mutations on the six hotspot sites within the region that encodes the DNA-binding domain of p53 give rise to other very different variants. The particular behavior of these variants led to consider p53 mutants as separate oncogene entities; that is, they do not retain wild type functions but acquire new ones, namely Gain-of-function p53 mutants. Furthermore, recent studies have revealed how p53 mutants regulate gene expression and exert oncogenic effects by unbalancing specific microRNAs (miRNAs) levels that provoke epithelial-mesenchymal transition, chemoresistance, and cell survival, among others. In this review, we discuss recent evidence of the crosstalk between miRNAs and mutants of p53, as well as the consequent cellular processes dysregulated.
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The malignant energetic demands are satisfied through glycolysis, glutaminolysis and de novo synthesis of fatty acids, while the host curses with a state of catabolism and systemic inflammation. The concurrent inhibition of both, tumor anabolism and host catabolism, and their effect upon tumor growth and whole animal metabolism, have not been evaluated. We aimed to evaluate in colon cancer cells a combination of six agents directed to block the tumor anabolism (orlistat + lonidamine + DON) and the host catabolism (growth hormone + insulin + indomethacin). Treatment reduced cellular viability, clonogenic capacity and cell cycle progression. These effects were associated with decreased glycolysis and oxidative phosphorylation, leading to a quiescent energetic phenotype, and with an aberrant transcriptomic landscape showing dysregulation in multiple metabolic pathways. The in vivo evaluation revealed a significant tumor volume inhibition, without damage to normal tissues. The six-drug combination preserved lean tissue and decreased fat loss, while the energy expenditure got decreased. Finally, a reduction in gene expression associated with thermogenesis was observed. Our findings demonstrate that the simultaneous use of this six-drug combination has anticancer effects by inducing a quiescent energetic phenotype of cultured cancer cells. Besides, the treatment is well-tolerated in mice and reduces whole animal energetic expenditure and fat loss.
Subject(s)
Cell Survival/drug effects , Colonic Neoplasms/drug therapy , Energy Metabolism/drug effects , Metabolic Networks and Pathways/drug effects , Animals , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Cell Line, Tumor , Colonic Neoplasms/metabolism , Colonic Neoplasms/pathology , Daunorubicin/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , Glycolysis/drug effects , Growth Hormone/pharmacology , Humans , Indazoles/pharmacology , Indomethacin/pharmacology , Insulin/pharmacology , Metabolism/drug effects , Mice , Mitoxantrone/pharmacology , Orlistat/pharmacology , Oxidative Phosphorylation/drug effects , Vincristine/pharmacologyABSTRACT
PURPOSE: Ivermectin is an antiparasitic drug that exhibits antitumor effects in preclinical studies, and as such is currently being repositioned for cancer treatment. However, divergences exist regarding its employed doses in preclinical works. Therefore, the aim of this study was to determine whether the antitumor effects of ivermectin are observable at clinically feasible drug concentrations. METHODS: Twenty-eight malignant cell lines were treated with 5 µM ivermectin. Cell viability, clonogenicity, cell cycle, cell death and pharmacological interaction with common cytotoxic drugs were assessed, as well as the consequences of its use on stem cell-enriched populations. The antitumor in vivo effects of ivermectin were also evaluated. RESULTS: The breast MDA-MB-231, MDA-MB-468, and MCF-7, and the ovarian SKOV-3, were the most sensitive cancer cell lines to ivermectin. Conversely, the prostate cancer cell line DU145 was the most resistant to its use. In the most sensitive cells, ivermectin induced cell cycle arrest at G0-G1 phase, with modulation of proteins associated with cell cycle control. Furthermore, ivermectin was synergistic with docetaxel, cyclophosphamide and tamoxifen. Ivermectin reduced both cell viability and colony formation capacity in the stem cell-enriched population as compared with the parental one. Finally, in tumor-bearing mice ivermectin successfully reduced both tumor size and weight. CONCLUSION: Our results on the antitumor effects of ivermectin support its clinical testing.
Subject(s)
Antineoplastic Agents/pharmacology , Antiparasitic Agents/pharmacology , Breast Neoplasms/drug therapy , Drug Repositioning/methods , Ivermectin/pharmacology , Animals , Apoptosis , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Cycle , Cell Movement , Cell Proliferation , Female , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Tumor Cells, Cultured , Xenograft Model Antitumor AssaysABSTRACT
Cancer upregulates glycolysis, glutaminolysis and lipogenesis, and induces a catabolic state in patients. The concurrent inhibition of both tumor anabolism and host catabolism, and the energetic consequences of such an approach, have not previously been fully investigated. In the present study, CT26.WT murine colon cancer cells were treated with the combination of anti-anabolic drugs orlistat, lonidamine and 6-diazo-5-oxo-L-norleucine (DON; OLD scheme), which are inhibitors of the de novo synthesis of fatty acids, glycolysis and glutaminolysis, respectively. In addition, the effects of OLD scheme sumplemented with the combination of anti-catabolic compounds, namely growth hormone, insulin and indomethacin (GII scheme), were also evaluated. The effects of the compounds used in combination on CT26.WT cell viability, clonogenicity and energetic metabolism were assessed in vitro. The results demonstrated that the anti-anabolic approach reduced cell viability, clonogenicity and cell cycle progression, and increased apoptosis. These effects were associated with decreased oxidative phosphorylation, glycolysis and fuel flexibility. Furthermore, the anti-catabolic scheme, alone or supplemented with anti-anabolic compounds, did not favor tumor growth. These findings indicated that the simultaneous pharmacological inhibition of tumor anabolism and host catabolism exhibits antitumor effects that should be further evaluated.
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[This corrects the article DOI: 10.3892/ol.2019.11008.].
ABSTRACT
Lonidamine, 6-Diazo-5-oxo-L-norleucine (DON) and orlistat are well known inhibitors of glycolysis, glutaminolysis and of de novo fatty acid synthesis, respectively. Although their antitumor effects have been explored in detail, the potential inhibition of the malignant metabolic phenotype and its influence on the expression of chemokines and growth factors involved in colon cancer, have not been previously reported to the best of our knowledge. In the present study, dose-response curves with orlistat, lonidamine or DON were generated from cell viability assays conducted in SW480 colon cancer cells. In addition, the synergistic effect of these compounds was evaluated in SW480 human colon cancer cells. The determination of the doses used for maximum synergistic efficacy led to the exploration of the mRNA levels of the target genes hexokinase-2 (HK2), glutaminase-1 (GLS-1) and fatty acid synthase (FASN) in human SW480 and murine CT26.WT colon cancer cells. The cell viability was evaluated following transfection with small interfering (si)RNA targeting these genes and was assessed with trypan blue. The expression levels of chemokines and growth factors were quantified in the supernatant of SW480 cells with LEGENDplex™. The combination of lonidamine, DON and orlistat resulted in a synergistic cytotoxic effect and induced the transcription of the corresponding gene targets but their corresponding proteins were actually downregulated. The downregulation of the expression levels of HK2, GLS-1 and FASN following transfection of the cells with the corresponding siRNA sequences decreased their viability. The treatment significantly reduced the expression levels of 9 chemokines [interleukin-9, C-X-C motif chemokine ligand (CXCL) 10, eotaxin, chemokine ligand (CCL) 9, CXCL5, CCL20, CXCL1, CXCL11 and CCCL4] and one growth factor (stem cell factor). These changes were associated with decreased phosphorylated-nuclear factor κB-p65. The data demonstrate that lonidamine, DON and orlistat in combination reduce the expression levels of chemokines and growth factors in colon cancer cells. Additional research is required to investigate the exact way by which both tumor and stromal cells regulate the expression levels of chemokines and growth factors.