Individual and joint effects of metformin and statins on mortality among patients with high-risk prostate cancer

Repurposing of atorvastatin and metformin denotes their individual and combined antiproliferative effects in non-small cell lung cancer

BACKGROUND

Due to the limited success in the treatment of lung adenocarcinomas, new treatment protocols are urgently needed to increase the curability rate and the survival of lung cancer patients.

OBJECTIVES

Although statins, like atorvastatin (Ator), and metformin (Met) are widely accepted as hypolipidemic and hypoglycemic drugs, respectively, there are many predictions about their enhancing antitumor effect when they are combined with traditional chemotherapeutics.

METHODS

The individual and combined antiproliferative potential of Ator and Met was tested by MTT-assay in non-small cell lung cancer (NSCLC) A549 cell line, compared to the corresponding effect of Gemcitabine (Gem) with implication on the mechanisms of action.

RESULTS

Initially, both drugs demonstrated concentration-dependent cytotoxicity in A549 cells. Also, their combination index (CI) indicated their synergistic effect at equi-IC50 concentration (CI = 0.00984). Moreover, Ator and/or Met-treated cells revealed disrupted patterns of SOD, CAT, GSH, MDA, and TAC, developed apoptosis, and larger fractions of the cell population were arrested in G0/G1 phase, particularly in cells dually-treated both Ator and Met. These observations were accompanied by downregulation in the expression of iNOS, HO-1, and the angiogenic marker VEGF, meanwhile, an altered expression of MAPK and AMPK was observed.

CONCLUSION

Conclusively, these data suggest that repurposing of Ator and Met demonstrates their individual and combined antiproliferative effect in non-small cell lung cancer and they may adopt a similar mechanism of action.

Cancer cells employ lipid droplets to survive toxic stress

BACKGROUND

Lipid reprogramming is a known mechanism to increase the energetic demands of proliferating cancer cells to drive and support tumorigenesis and progression. Elevated lipid droplets (LDs) are a well-known alteration of lipid reprogramming in many cancers, including prostate cancer (PCa), and are associated with high tumor aggressiveness as well as therapy resistance. The mechanism of LD accumulation and specific LD functions are still not well understood; however, it has been shown that LDs can form as a protective mechanism against lipotoxicity and lipid peroxidation in the cell.

METHODS

This study investigated the significance of LDs in PCa. This was done by staining, imaging, image quantification, and flow cytometry analysis of LDs in PCa cells. Additionally, lipidomics and metabolomics experiments were performed to assess the difference of metabolites and lipids in control and treatment surviving cancer cells. Lastly, to assess clinical significance, multiple publicly available datasets were mined for LD-related data.

RESULTS

Our study demonstrated that prostate and breast cancer cells that survive 72 h of chemotherapy treatment have elevated LDs. These LDs formed in tandem with elevated reactive oxygen species levels to sequester damaged and excess lipids created by oxidative stress, which promoted cell survival. Additionally, by inhibiting diacylglycerol O-acyltransferase 1 (DGAT1) (which catalyzes triglyceride synthesis into LDs) and treating with chemotherapy simultaneously, we were able to decrease the overall amount of LDs and increase cancer cell death compared to treating with chemotherapy alone.

CONCLUSIONS

Overall, our study proposes a potential combination therapy of DGAT1 inhibitors and chemotherapy to increase cancer cell death.

Metformin: A Dual-Role Player in Cancer Treatment and Prevention

Cancer continues to pose a significant global health challenge, as evidenced by the increasing incidence rates and high mortality rates, despite the advancements made in chemotherapy. The emergence of chemoresistance further complicates the effectiveness of treatment. However, there is growing interest in the potential of metformin, a commonly prescribed drug for type 2 diabetes mellitus (T2DM), as an adjuvant chemotherapy agent in cancer treatment. Although the precise mechanism of action of metformin in cancer therapy is not fully understood, it has been found to have pleiotropic effects, including the modulation of metabolic pathways, reduction in inflammation, and the regulation of cellular proliferation. This comprehensive review examines the anticancer properties of metformin, drawing insights from various studies conducted in vitro and in vivo, as well as from clinical trials and observational research. This review discusses the mechanisms of action involving both insulin-dependent and independent pathways, shedding light on the potential of metformin as a therapeutic agent for different types of cancer. Despite promising findings, there are challenges that need to be addressed, such as conflicting outcomes in clinical trials, considerations regarding dosing, and the development of resistance. These challenges highlight the importance of further research to fully harness the therapeutic potential of metformin in cancer treatment. The aims of this review are to provide a contemporary understanding of the role of metformin in cancer therapy and identify areas for future exploration in the pursuit of effective anticancer strategies.

Allopurinol and prostate cancer survival in a Finnish population-based cohort

BACKGROUND

Allopurinol is gout medication that inhibits uric acid formation. Its possible anti-carcinogenic properties have been under research in past years. Studies based on Taiwanese registries showed that long term allopurinol use might reduce prostate cancer (PCa) incidence. However, our studies based on Finnish registries did not support those findings. In this study, we evaluate whether allopurinol use is associated with prostate cancer-specific survival (CSS) or overall survival (OS) in a Finnish population-based cohort.

METHODS

The study cohort was originally enrolled for the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC). We included all newly diagnosed PCa cases during 1996-2015, 9252 men in total. Information on allopurinol purchases was from the national prescription registry of the Social Insurance Institution of Finland. Information about deaths, treatments, and use of other medications was obtained from registries, and tumor stage and PSA at diagnosis from medical records. Follow-up started at diagnosis, and we analysed separately two endpoints: PCa-specific death and overall death. We used an extended Cox regression with adjustment for age at diagnosis, Charlson comorbidity index, FinRSPC trial arm, use of other drugs and EAU PCa risk group.

RESULTS

During a median follow-up of 9.86 years, 2942 deaths occurred, including 883 from PCa. There was no difference in CSS between allopurinol user and non-users, but allopurinol users had lower OS (multivariable-adjusted hazard ratio 1.77; 95% CI: 1.57-2.00). However, this decrease in OS was mitigated along with increasing intensity of allopurinol use.

CONCLUSIONS

We found no marked difference in CSS by allopurinol use. Allopurinol users had lower OS but there were no significant differences by duration or intensity of allopurinol use. Allopurinol use may not have anticancer effects against prostate cancer; instead, it may be a surrogate for metabolic problems causing shorter OS among men with PCa.

The Impact of Statins on the Survival of Patients with Advanced Hepatocellular Carcinoma Treated with Sorafenib or Lenvatinib

We aimed to evaluate the survival benefits of coadministering statins and multityrosine kinase inhibitors (TKIs) in patients with advanced hepatocellular carcinoma (HCC). Data from the Health Insurance Review and Assessment Service in Korea (2010-2020) were utilized. Statin use (≥28 cumulative defined daily doses) was analyzed, with 1534 statin users matched to 6136 non-users (1:4 ratio) using propensity scores. Primary and secondary outcomes were overall survival (OS) and progression-free survival (PFS). Statin use significantly improved OS (hazard ratio [HR] 0.77, 95% confidence interval [CI] 0.72-0.82, p < 0.001) and PFS (HR 0.78, 95% CI 0.74-0.84, p < 0.001). Continuous or post-TKI statin users had better OS, while discontinuation after TKI use led to poorer OS. Both lipophilic and hydrophilic statins improved OS and PFS, particularly with ≥730 cumulative defined daily doses. In conclusion, combining statins and TKIs in patients with advanced HCC yielded significant survival benefits, influenced by statin dosage and duration. Continuous statin administration post-TKI treatment is crucial for improving outcomes in patients with HCC.

Association Between Statin Exposure and Incidence and Prognosis of Prostate Cancer: A Meta-analysis Based on Observational Studies

It is widely thought that statins have huge therapeutic potential against prostate cancer (PCA). This study aimed to investigate the effect of statin exposure on PCA incidence and prognosis. PubMed, Web of Science, Embase, and Cochrane databases were searched for observational studies on the association between statin exposure and PCA from inception until July 2022. The primary endpoints were the incidence of PCA and the survival rate. A total of 21 studies were included in this meta-analysis. The pooled estimates showed that exposure to hydrophilic statins was not associated with the incidence of PCA (odds ratio [OR]=0.94, 95% CI=0.88-1.01, P =0.075), while the incidence of PCA was significantly decreased in populations exposed to lipophilic statins compared with the nonexposed group (OR=0.94, 95% CI=0.90-0.98, P =0.001), mainly in Western countries (OR=0.94, 95% CI=0.91-0.98, P =0.006). Subgroup analysis showed that simvastatin (OR=0.83, 95% CI=0.71-0.97, P =0.016) effectively reduced the incidence of PCA. The prognosis of PCA in patients exposed to both hydrophilic (hazard ratio [HR]=0.57, 95% CI=0.49-0.66, P <0.001) and lipophilic (HR=0.65, 95% CI=0.58-0.73, P <0.001) statins were better than in the nonexposed group, and this improvement was more significant in the East than in Western countries. This study demonstrates that statins can reduce the incidence of PCA and improve prognosis, and are affected by population region and statin properties (hydrophilic and lipophilic).

Prognostic value of metformin in cancers: An updated meta-analysis based on 80 cohort studies

BACKGROUND

Experiments have shown that metformin can inhibit cancer cell growth, but clinical observations have been inconsistent, so we pooled the currently available data to evaluate the impact of metformin on cancer survival and progression.

METHODS

PubMed, web of science, Embase, and Cochrane databases were searched. Pooled hazard ratios (HRs) were identified using a random-effects model to estimate the strength of the association between metformin and survival and progression in cancer patients.

RESULTS

We incorporated 80 articles published from all databases which satisfied the inclusion criterion. It showed that metformin was associated with better overall survival (hazard ratio [HR] = 0. 81; 95% confidence interval [CI]: [0.77-0.85]) and cancer-specific survival (HR = 0.79; 95% CI: [0.73-0.86]), and metformin was associated with progression-free survival (HR = 0.76; 95% CI: [0.66-0.87]). In patients with diabetes mellitus, the HR of overall survival was 0.79(95% CI: [0.75-0.83]), progression-free survival was 0.72(95% CI: [0.60-0.85]), and the cancer-specific survival was 0.76(95% CI: [0.68-0.86]). It was proposed that metformin can improve the prognosis of cancer patients with diabetes mellitus.

CONCLUSION

Based on cohort studies, metformin therapy has potential survival benefits for patients with malignancy, especially with the greatest benefits seen in breast cancer on overall survival, progression-free survival, and cancer-specific survival. And metformin also showed potential benefits in cancer-specific survival in colorectal and prostate cancer.

Metformin and testosterone replacement therapy inversely associated with hormone-associated cancers (prostate, colorectal and male breast cancers) among older White and Black men

BACKGROUND

The independent and joint association of metformin and testosterone replacement therapy (TTh) with the incidence of prostate, colorectal, and male breast cancers remain poorly understood, including the investigation of the risk of these cancers combined (HRCs, hormone-associated cancers) among men of different racial and ethnic background.

METHODS

In 143,035 men (≥ 65 yrs old) of SEER-Medicare 2007-2015, we identified White (N = 110,430), Black (N = 13,520) and Other Race (N = 19,085) men diagnosed with incident HRC. Pre-diagnostic prescription of metformin and TTh was ascertained for this analysis. Weighted multivariable-adjusted conditional logistic and Cox proportional hazards models were conducted.

RESULTS

We found independent and joint associations of metformin and TTh with incident prostate (odds ratio [OR]joint  = 0.44, 95% confidence interval [CI]: 0.36-0.54) and colorectal cancers (ORjoint  = 0.47, 95% CI: 0.34-0.64), but not with male breast cancer. There were also inversed joint associations of metformin and TTh with HRCs (ORjoint  = 0.45, 95% CI: 0.38-0.54). Similar reduced associations with HRCs were identified among White, Black, and Other Race men.

CONCLUSION

Pre-diagnostic use of metformin and TTh were, independently and jointly, inversely associated with incident prostate and colorectal cancers. The risk of HRCs was also reduced among White, Black and Other Race men. Greatest reduced associations of prostate and colorectal cancers and HRCs were mainly observed in combination of metformin and TTh. Larger studies are needed to confirm the independent and joint association of metformin plus TTh with these cancers in understudied and underserved populations.

The effect of medical castration on lipid levels in black South African men with prostate cancer

Background

In South Africa, androgen deprivation therapy (ADT) is commonly given as primary therapy for prostate cancer (PCa) due to many patients presenting with advanced disease. The metabolic adverse effects of ADT on lipid profile and weight gain have been reported mainly in Caucasian populations, but few studies have been performed in African populations. Men of African descent generally have favorable lipid profiles compared to other populations, and our study looked to analyze the effect of medical castration on lipid levels in black South African men with PCa.

Methods

The aim of this study is to describe the changes in blood total cholesterol, triglycerides, LDL and HDL at 6 months and at 1 year in men with prostate cancer newly initiated on ADT. Changes to BMI, waist circumference and HbA1c were also measured after 1 year of ADT.

Our study was conducted at Chris Hani Baragwanath Academic Hospital which is a teaching hospital affiliated with the University of the Witwatersrand. It is located in Soweto, South of Johannesburg, and serves the 1.3 million local residents who are predominantly black and of the lower-income bracket. This study enrolled 38 black South African men who were starting to receive ADT for PCa. Subjects were evaluated at baseline and at 6 and 12 months. Lipid profiles and HbA1C levels were measured using blood samples, and body composition was measured using BMI and waist circumference.

Results

In this prospective single-center study, we found that ADT resulted in a significant rise in triglyceride levels and weight gain in black South African men reaching mean levels of obesity using ethnic-specific definitions. High-density lipoproteins levels decreased significantly particularly in the first 6 months of treatment and thereafter began to rise. ADT also resulted in an increased HbA1C level which is a marker for insulin resistance.

Conclusions

Androgen deprivation therapy unfavorably changed the body habitus and lipid profile of men with PCa. It was demonstrated that even black South Africans who generally have favorable lipid profiles compared to their counterparts are at risk of developing metabolic syndrome while being treated with ADT.

Statin Use Is Associated with Better Prognosis of Patients with Prostate Cancer after Definite Therapies: A Systematic Review and Meta-Analysis of Cohort Studies

OBJECTIVE

Although the prognostic effect of statins on patients with prostate cancer (PCa) has been frequently evaluated, a consistent result is still lacking. We aimed to evaluate the association between statin use and mortality among patients with PCa after definite therapies.

METHODS

A systematic search of PubMed and other databases for cohort studies about the effect of statins on patients with PCa was performed until April 2022. Meta-analysis was performed using R software version 4.1.2.

RESULTS

24 cohort studies involving 369, 206 participants were finally included. We found statin use significantly reduced the risk of prostate cancer-specific mortality (PCSM) with a pooled hazard ratio (pHR) = 0.76 (95% CI: 0.69-0.84, 18 studies), especially for postdiagnostic statin users: pHR = 0.81 (95% CI: 0.77-0.85) and patients who accepted androgen deprivation therapy (ADT): pHR = 0.69 (95% CI: 0.59-0.81). Statin use was also associated with a 24% reduction in the risk of all-cause mortality (ACM): pHR = 0.76 (95% CI: 0.68-0.85, 17 studies), especially for postdiagnostic statin users: pHR = 0.81 (95% CI: 0.78-0.85) and patients treated with ADT: pHR = 0.72 (95% CI: 0.63-0.82) or radiotherapy (RT): pHR = 0.68 (95% CI: 0.50-0.93).

CONCLUSION

In conclusion, the use of statins could promote the prognosis of patients with PCa, especially for postdiagnostic users. For patients who received either ADT or radical prostatectomy (RP), statin use could decrease the PCSM. As for those who received either ADT or RT, statin use could decrease the ACM.

Effect of Statins on All-Cause Mortality in Adults: A Systematic Review and Meta-Analysis of Propensity Score-Matched Studies

Statins are lipid-lowering medications used for the prevention of cardiovascular disease (CVD), but the pleiotropic effects of statins might be beneficial in other chronic diseases. This meta-analysis investigated the association between statin use and mortality in different chronic conditions. Eligible studies were real-world studies that compared all-cause mortality over at least 12 months between propensity score-matched statin users and non-users. Overall, 54 studies were included: 21 in CVD, 6 in chronic kidney disease, 6 in chronic inflammatory diseases, 3 in cancer, and 18 in other diseases. The risk of all-cause mortality was significantly reduced in statin users (hazard ratio: 0.72, 95% confidence interval: 0.66−0.76). The reduction in mortality risk was similar in CVD studies (0.73, 0.66−0.76) and non-CVD studies (0.70, 0.67−0.79). There were no significant differences in the risk reduction between cohorts with different diseases (p = 0.179). The greatest mortality reduction was seen in studies from Asia (0.61, 0.61−0.73) and the lowest in studies from North America (0.78, 0.73−0.83) and Australia (0.78, 0.62−0.97). There was a significant heterogeneity (I2 = 95%, tau2 = 0.029, p < 0.01). In conclusion, statin use was associated with a significantly reduced risk of all-cause mortality in real-world cohorts with CVD and non-CVD.

Mutant p53, the Mevalonate Pathway and the Tumor Microenvironment Regulate Tumor Response to Statin Therapy

Tumor cells have the ability to co-opt multiple metabolic pathways, enhance glucose uptake and utilize aerobic glycolysis to promote tumorigenesis, which are characteristics constituting an emerging hallmark of cancer. Mutated tumor suppressor and proto-oncogenes are frequently responsible for enhanced metabolic pathway signaling. The link between mutant p53 and the mevalonate (MVA) pathway has been implicated in the advancement of various malignancies, with tumor cells relying heavily on increased MVA signaling to fuel their rapid growth, metastatic spread and development of therapy resistance. Statin drugs inhibit HMG-CoA reductase, the pathway’s rate-limiting enzyme, and as such, have long been studied as a potential anti-cancer therapy. However, whether statins provide additional anti-cancer properties is worthy of debate. Here, we examine retrospective, prospective and pre-clinical studies involving the use of statins in various cancer types, as well as potential issues with statins’ lack of efficacy observed in clinical trials and future considerations for upcoming clinical trials.

Evidence on Statins, Omega-3, and Prostate Cancer: A Narrative Review

Dietary intake selections might play a crucial role in prostate cancer (PCa) occurrence and progression. Several studies have investigated whether statin use could reduce PCa risk but with conflicting results. Nevertheless, a significantly decreased incidence of advanced PCa has been consistently noted. Statins may also reduce the risk of biochemical recurrence (BCR) in men with PCa after receiving active treatment. However, the influence of statin usage on BCR and PCa progression in men with high prostate-specific antigen levels has been found to be insignificant. In contrast, the combined use of a statin and metformin was significantly related to the survival status of PCa patients. However, some studies have revealed that the intake of long-chain omega-3 fatty acid (ω-3) from fish or fish oil supplements may elevate PCa risk. Several meta-analyses on ω-3 consumption and PCa have shown controversial results for the relationship between PCa and ω-3 consumption. However, studies with positive results for various genotypes, fatty acid intake or levels, and PCA risk are emerging. This review highlights the association among statins, ω-3, and PCa. The findings summarized here may be helpful for clinicians counseling patients related to PCa.

Statins for Cardiac and Vascular Protection During and After Cancer Therapy

PURPOSE OF REVIEW

Although cancer treatments have increased overall survival rates, the cardiovascular consequences of cancer therapy place patients at an increased risk of adverse outcomes. This manuscript presents data accumulated to date regarding cardiovascular outcomes relating to the administration of 3-hydroxy-3-methylglutarylcoenzyme-A reductase inhibitor (or statin) therapy in individuals receiving potentially cardiotoxic cancer treatments.

RECENT FINDINGS

Retrospective observational studies in humans and randomized controlled trials in animals suggest that statins may reduce cancer-specific and all-cause mortality. Further, statins may attenuate cancer therapy-induced declines in left ventricular ejection fraction (LVEF) and increases in blood pressure. Observational studies suggest a potential attenuation in LVEF decline in patients with cancer and primary or secondary indications to receive a statin for prevention of cardiovascular events. Large randomized clinical trials are warranted to understand the efficacy and potential impacts of statin class, dosage, and duration on cardiovascular outcomes in patients treated for cancer.

Improved survival with post-diagnostic metformin and statin use in a racially diverse cohort of US Veterans with advanced prostate cancer

OBJECTIVE

To examine the association between post-diagnostic metformin or statin use with all-cause and prostate cancer (PCa)-specific mortality in men with advanced prostate cancer.

METHODS

Our study consisted of 4572 men (Black = 1352, White = 3192, Other Race = 28) diagnosed with advanced cancer (T4/M1/N1) between 1999 and 2013 in the Veteran Health Administration. The association between post-diagnostic (1) metformin and (2) statin use with all-cause and PCa-specific mortality was examined using multivariable, time-varying Cox Proportional Hazard Models. In a secondary analysis, models were stratified by race.

RESULTS

Post-diagnostic metformin use was associated with a reduced risk of all-cause (Hazard Ratio (HR) 0.84, 95% Confidence Interval (CI): 0.73, 0.96) and PCa-specific death (HR: 0.76, 95% CI: 0.63, 0.91). In stratified analyses, the inverse association between post-diagnostic metformin use and both all-cause PCa-specific mortality was limited to White men. Post-diagnostic statin use was associated with a reduced risk of all-cause (HR: 0.75, 95% CI: 0.68, 0.83) and PCa-specific mortality (HR: 0.72; 95% CI: 0.64, 0.81). In stratified analyses, similar inverse associations were observed for post-diagnostic statin use and all-cause and PCa-specific mortality in both Black and White men.

CONCLUSION

Post diagnostic metformin and statin use may prevent progression to lethal prostate cancer in men with advanced prostate cancer.

Role of metformin and other metabolic drugs in the prevention and therapy of endocrine-related cancers

Metabolic syndrome is associated with chronic diseases, including type 2 diabetes, cardiovascular diseases, and cancer. This review summarizes the current evidence on the antitumor effects of some relevant drugs currently used to manage metabolic-related pathologies (i.e. insulin and its analogs, metformin, statins, etc.) in endocrine-related cancers including breast cancer, prostate cancer, pituitary cancer, ovarian cancer, and neuroendocrine neoplasms. Although current evidence does not provide a clear antitumor role of several of these drugs, metformin seems to be a promising chemopreventive and adjuvant agent in cancer management, modulating tumor cell metabolism and microenvironment, through both AMP-activated protein kinase-dependent and -independent mechanisms. Moreover, its combination with statins might represent a promising therapeutic strategy to tackle the progression of endocrine-related tumors. However, further studies are needed to endorse the clinical relevance of these drugs as adjuvants for cancer chemotherapy.

Statin as a Potential Chemotherapeutic Agent: Current Updates as a Monotherapy, Combination Therapy, and Treatment for Anti-Cancer Drug Resistance

Cancer is incurable because progressive phenotypic and genotypic changes in cancer cells lead to resistance and recurrence. This indicates the need for the development of new drugs or alternative therapeutic strategies. The impediments associated with new drug discovery have necessitated drug repurposing (i.e., the use of old drugs for new therapeutic indications), which is an economical, safe, and efficacious approach as it is emerged from clinical drug development or may even be marketed with a well-established safety profile and optimal dosing. Statins are inhibitors of HMG-CoA reductase in cholesterol biosynthesis and are used in the treatment of hypercholesterolemia, atherosclerosis, and obesity. As cholesterol is linked to the initiation and progression of cancer, statins have been extensively used in cancer therapy with a concept of drug repurposing. Many studies including in vitro and in vivo have shown that statin has been used as monotherapy to inhibit cancer cell proliferation and induce apoptosis. Moreover, it has been used as a combination therapy to mediate synergistic action to overcome anti-cancer drug resistance as well. In this review, the recent explorations are done in vitro, in vivo, and clinical trials to address the action of statin either single or in combination with anti-cancer drugs to improve the chemotherapy of the cancers were discussed. Here, we discussed the emergence of statin as a lipid-lowering drug; its use to inhibit cancer cell proliferation and induction of apoptosis as a monotherapy; and its use in combination with anti-cancer drugs for its synergistic action to overcome anti-cancer drug resistance. Furthermore, we discuss the clinical trials of statins and the current possibilities and limitations of preclinical and clinical investigations.

Attempts to use statins in cancer therapy: An update

Although it could be speculated that almost everything has been said concerning the use of statins in cancer therapy, statins as anticancer drugs have both committed supporters and opponents, for whom the dispute about the legitimacy of statin use in cancer treatment seems never to be clearly resolved; every year more than 300 reports which deepen the knowledge about statins and their influence on cancer cells are published. In this mini-review, we focus on the latest (since 2015) outcomes of cohort studies and meta-analyses indicating statin effectiveness in cancer treatment. We discuss attempts to improve the bioavailability of statins using nanocarriers and review the effectiveness of statins in combined therapies. We also summarise the latest results regarding the development of mechanisms of resistance to statins by cancer cells and, on the other hand, give a few examples where statins could potentially be used to overcome resistance to commonly used chemotherapeutics. Finally, special attention is paid to new reports on the effect of statins on epithelial-mesenchymal transition.

Androgen Deprivation Induces Reprogramming of Prostate Cancer Cells to Stem-Like Cells

In the past few years, cell plasticity has emerged as a mode of targeted therapy evasion in prostate adenocarcinoma. When exposed to anticancer therapies, tumor cells may switch into a different histological subtype, such as the neuroendocrine phenotype which is associated with treatment failure and a poor prognosis. In this study, we demonstrated that long-term androgen signal depletion of prostate LNCaP cells induced a neuroendocrine phenotype followed by re-differentiation towards a “stem-like” state. LNCaP cells incubated for 30 days in charcoal-stripped medium or with the androgen receptor antagonist 2-hydroxyflutamide developed neuroendocrine morphology and increased the expression of the neuroendocrine markers βIII-tubulin and neuron specific enolase (NSE). When cells were incubated for 90 days in androgen-depleted medium, they grew as floating spheres and had enhanced expression of the stem cell markers CD133, ALDH1A1, and the transporter ABCB1A. Additionally, the pluripotent transcription factors Nanog and Oct4 and the angiogenic factor VEGF were up-regulated while the expression of E-cadherin was inhibited. Cell viability revealed that those cells were resistant to docetaxel and 2-hidroxyflutamide. Mechanistically, androgen depletion induced the decrease in AMP-activated kinase (AMPK) expression and activation and stabilization of the hypoxia-inducible factor HIF-1α. Overexpression of AMPK in the stem-like cells decreased the expression of stem markers as well as that of HIF-1α and VEGF while it restored the levels of E-cadherin and PGC-1α. Most importantly, docetaxel sensitivity was restored in stem-like AMPK-transfected cells. Our model provides a new regulatory mechanism of prostate cancer plasticity through AMPK that is worth exploring.

Repurposing of drugs: An attractive pharmacological strategy for cancer therapeutics

Human malignancies are one of the major health-related issues though out the world and anticipated to rise in the future. The development of novel drugs/agents requires a huge amount of cost and time that represents a major challenge for drug discovery. In the last three decades, the number of FDA approved drugs has dropped down and this led to increasing interest in drug reposition or repurposing. The present review focuses on recent concepts and therapeutic opportunities for the utilization of antidiabetics, antibiotics, antifungal, anti-inflammatory, antipsychotic, PDE inhibitors and estrogen receptor antagonist, Antabuse, antiparasitic and cardiovascular agents/drugs as an alternative approach against human malignancies. The repurposing of approved non-cancerous drugs is an effective strategy to develop new therapeutic options for the treatment of cancer patients at an affordable cost in clinics. In the current scenario, most of the countries throughout the globe are unable to meet the medical needs of cancer patients because of the high cost of the available cancerous drugs. Some of these drugs displayed potential anti-cancer activity in preclinic and clinical studies by regulating several key molecular mechanisms and oncogenic pathways in human malignancies. The emerging pieces of evidence indicate that repurposing of drugs is crucial to the faster and cheaper discovery of anti-cancerous drugs.

Individual and joint effects of metformin and statins on mortality among patients with high-risk prostate cancer

BACKGROUND

Pre-clinical studies suggest that metformin and statins may delay prostate cancer (PCa) metastases; however, data in humans are limited. To the best of our knowledge, this is the first human study aimed to quantify the individual and joint effects of statin and metformin use among patients with high-risk PCa.

METHODS

This population-based retrospective cohort study identified patients from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database. Exposure to metformin and statins was ascertained from Medicare Prescription Drug Event files. The association with all-cause and PCa mortality were evaluated using Cox proportional hazard model with competing causes of death, where propensity scores were used to adjusted imbalances in covariates across groups.

RESULTS

Based on 12 700 patients with high-risk PCa, statin alone or in combination with metformin was significantly associated with reduced all-cause mortality (Hazard Ratio [HR]: 0.89; 95% Confidence Interval [CI]: 0.83, 0.96; and HR: 0.75; 95% CI, 0.67-0.83, respectively) and PCa mortality (HR, 0.80; 95% CI: 0.69, 0.92) and 0.64; 95% CI, d 0.51-0.81, respectively. The effects were more pronounced in post-diagnostic users: combination use of metformin/statins was associated with a 32% reduction in all-cause mortality (95% CI, 0.57-0.80), and 54% reduction in PCa mortality (95% CI, 0.30-0.69). No significant association of metformin alone was observed with either all-cause mortality or PCa mortality.

CONCLUSIONS

Statin use alone or in combination with metformin was associated with lower all-cause and PCa mortality among high-risk patients, particularly in post-diagnostic settings; further studies are warranted.