Simvastatin plus irinotecan, 5-fluorouracil, and leucovorin (FOLFIRI) as first-line chemotherapy in metastatic colorectal patients: a multicenter phase II study

Cholesterol-ferroptosis nexus: Unveiling novel cancer therapeutic avenues

Ferroptosis, a novel form of regulated cell death characterized by iron-mediated lipid peroxidation, holds immense potential in cancer therapeutics due to its role in tumor progression and resistance. This review predominantly explores the intricate relationship between ferroptosis and cholesterol metabolism pathways, mainly focusing on the cholesterol biosynthesis pathway. This review highlights the therapeutic implications of targeting cholesterol metabolism pathways for cancer treatment by delving into the mechanisms underlying ferroptosis regulation. Strategies such as inhibiting HMG-CoA reductase and suppressing squalene synthesis offer promising avenues for inducing ferroptosis in cancer cells. Moreover, insights into targeting the 7-dehydrocholesterol pathway provide novel perspectives on modulating ferroptosis susceptibility and managing ferroptosis-associated diseases. Understanding the interplay between ferroptosis and cholesterol metabolism pathways underscores the potential of lipid metabolism modulation as an innovative therapeutic approach in cancer treatment.

Statins as anti-tumor agents: A paradigm for repurposed drugs

BACKGROUND

Statins, frequently prescribed medications, work by inhibiting the rate-limiting enzyme HMG-CoA reductase (HMGCR) in the mevalonate pathway to reduce cholesterol levels. Due to their multifaceted benefits, statins are being adapted for use as cost-efficient, safe and effective anti-cancer treatments. Several studies have shown that specific types of cancer are responsive to statin medications since they rely on the mevalonate pathway for their growth and survival.

RECENT FINDINGS

Statin are a class of drugs known for their potent inhibition of cholesterol production and are typically prescribed to treat high cholesterol levels. Nevertheless, there is growing interest in repurposing statins for the treatment of malignant neoplastic diseases, often in conjunction with chemotherapy and radiotherapy. The mechanism behind statin treatment includes targeting apoptosis through the BCL2 signaling pathway, regulating the cell cycle via the p53-YAP axis, and imparting epigenetic modulations by altering methylation patterns on CpG islands and histone acetylation by downregulating DNMTs and HDACs respectively. Notably, some studies have suggested a potential chemo-preventive effect, as decreased occurrence of tumor relapse and enhanced survival rate were reported in patients undergoing long-term statin therapy. However, the definitive endorsement of statin usage in cancer therapy hinges on population based clinical studies with larger patient cohorts and extended follow-up periods.

CONCLUSIONS

The potential of anti-cancer properties of statins seems to reach beyond their influence on cholesterol production. Further investigations are necessary to uncover their effects on cancer promoting signaling pathways. Given their distinct attributes, statins might emerge as promising contenders in the fight against tumorigenesis, as they appear to enhance the efficacy and address the limitations of conventional cancer treatments.

Repositioning of simvastatin for diabetic colon cancer: role of CDK4 inhibition and apoptosis

There is increased risk of colon cancer in both men and women having diabetes. The objective of the study was to evaluate the role of simvastatin in colon cancer associated with type 2 diabetes mellitus. Diabetes was induced by administering high fat diet with low dose streptozotocin model. 1,2 dimethylhydrazine (25 mg/kg, sc) was used for colon cancer induction. MTT assay, scratch assay, clonogenic assay and annexin V-FITC assay using flow cytometry were performed on HCT-15 cell line. Simvastatin controlled diabetes and colon cancer in animal models and reduced mRNA expression of CDK4 in colon tissues. In vitro studies revealed that simvastatin showed a decrease in cell viability and produced dose dependent decrease in clone formation. There was decrease in the rate of migration with increase in concentration of simvastatin in scratch assay. Moreover, simvastatin induced apoptosis as depicted from annexin V-FITC assay using flow cytometry as well as that revealed by tunnel assay. Our data suggest that simvastatin exhibits protective role in colon cancer associated with diabetes mellitus and acts possibly via down regulation of CDK4 and induction of apoptosis and hence can be considered for repositioning in diabetic colon cancer.

A phase 1 study of simvastatin in combination with topotecan and cyclophosphamide in pediatric patients with relapsed and/or refractory solid and CNS tumors

BACKGROUND

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) can inhibit tumor proliferation, angiogenesis, and restore apoptosis in preclinical pediatric solid tumor models. We conducted a phase 1 trial to determine the maximum tolerated dose (MTD) of simvastatin with topotecan and cyclophosphamide in children with relapsed/refractory solid and central nervous system (CNS) tumors.

METHODS

Simvastatin was administered orally twice daily on days 1-21, with topotecan and cyclophosphamide intravenously on days 1-5 of a 21-day cycle. Four simvastatin dose levels (DLs) were planned, 140 (DL1), 180 (DL2), 225 (DL3), 290 (DL4) mg/m2 /dose, with a de-escalation DL of 100 mg/m2 /dose (DL0) if needed. Pharmacokinetic and pharmacodynamic analyses were performed during cycle 1.

RESULTS

The median age of 14 eligible patients was 11.5 years (range: 1-23). The most common diagnoses were neuroblastoma (N = 4) and Ewing sarcoma (N = 3). Eleven dose-limiting toxicity (DLT)-evaluable patients received a median of four cycles (range: 1-6). There were three cycle 1 DLTs: one each grade 3 diarrhea and grade 4 creatine phosphokinase (CPK) elevations at DL1, and one grade 4 CPK elevation at DL0. All patients experienced at least one grade 3/4 hematologic toxicity. Best overall response was partial response in one patient with Ewing sarcoma (DL0) and stable disease for four or more cycles in four patients. Simvastatin exposure increased with higher doses and may have correlated with toxicity. Plasma interleukin 6 (IL-6) concentrations (N = 6) showed sustained IL-6 reductions with decrease to normal values by day 21 in all patients, indicating potential on-target effects.

CONCLUSIONS

The MTD of simvastatin with topotecan and cyclophosphamide was determined to be 100 mg/m2 /dose.

A Phase II Study of Preoperative Chemoradiotherapy with Capecitabine Plus Simvastatin in Patients with Locally Advanced Rectal Cancer

PURPOSE

The purpose of this phase II trial was to evaluate whether the addition of simvastatin, a synthetic 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, to preoperative chemoradiotherapy (CRT) with capecitabine confers a clinical benefit to patients with locally advanced rectal cancer (LARC).

MATERIALS AND METHODS

Patients with LARC (defined by clinical stage T3/4 and/or lymph node positivity) received preoperative radiation (45-50.4 Gy in 25-28 daily fractions) with concomitant capecitabine (825 mg/m2 twice per day) and simvastatin (80 mg, daily). Curative surgery was planned 4-8 weeks after completion of the CRT regimen. The primary endpoint was pathologic complete response (pCR). The secondary endpoints included sphincter-sparing surgery, R0 resection, disease-free survival, overall survival, the pattern of failure, and toxicity.

RESULTS

Between October 2014 and July 2017, 61 patients were enrolled; 53 patients completed CRT regimen and underwent total mesorectal excision. The pCR rate was 18.9% (n=10) by per-protocol analysis. Sphincter-sparing surgery was performed in 51 patients (96.2%). R0 resection was achieved in 51 patients (96.2%). One patient experienced grade 3 liver enzyme elevation. No patient experienced additional toxicity caused by simvastatin.

CONCLUSION

The combination of 80 mg simvastatin with CRT and capecitabine did not improve pCR in patients with LARC, although it did not increase toxicity.

[STE029 Overcomes EGFR-TKI Resistance in Human Lung Adenocarcinoma]

BACKGROUND

Acquired and primary resistance to epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) is still the bottleneck of clinical treatment of advanced non-small cell lung cancer (NSCLC). STE029 is a novel anticancer drug which consists of 3-hydroxy-3-methylglutarylcoenzyme A reductase (HMGCR) inhibitor and novel cancer cell membrane targeting molecular. This study aimed to investigate the reversal mechanism of EGFR-TKI resistance by STE029 in lung adenocarcinoma.

METHODS

CCK8 test was used to test the cell viability and survival rate of EGFR mutated PC9 cell (Gefitinib sensitive), PC9/BB4 cell (acquired Gefitinib resistant), and EGFR wild type A549 cell after treatment of STE029, Gefitinib or combination of both. EdU test was applied to detect changes in cell cycle and Hoechst 33258 was applied to detect apoptosis rate in overcoming the EGFR-TKI resistance. The activity of EGFR/PI3K/Akt, cell cycle and apoptosis signal pathways were examined. In vivo, nude mice were exposed to STE029, Gefitinib and STE029+Gefitinib for 5 wk. And the the tumor volume was measured and tumor weight was obtained on the last day.

RESULTS

(1) PC9 cells was highly sensitive to Gefitinib, while PC9/BB4 and A549 cell showed significant resistance to Gefitinib treatment; (2) STE029+Gefitinib treatment could significantly decrease the 50% inhibitory concentrarion (IC₅₀) of Gefitinib in PC9, PC9/BB4 and A549 cells (P<0.05, respectively); (3) In PC9 and PC9/BB4 cells, STE029+Gefitinib can block cell cycle and inhibit cell proliferation (P<0.001), while there was no significant difference in apoptosis rate among three drug intervention groups (P>0.05); However, apoptosis rate was increased in STE029+Gefitinib group in A549 cell (P<0.01), while no significance detected in cell proliferation (P>0.05). (4) In PC9 and PC9/BB4 cells, the combination of STE029 and Gefitinib could downregulate p-EGFR, p-Akt, p-Cyclin D1 and Cyclin D1 (P<0.001), and upregulate the expression of GSK-3β (P<0.001), and the expression of cleaved caspase-8, caspase-8 cleaved caspase-9, caspase-9 showed no difference among groups (P>0.05). In A549 cells, the combination of STE029 and Gefitinib could downregulate p-Akt (P<0.001) and upregulate cleaved caspase-8 and cleaved caspase-9 (P<0.001); (5)In vivo, the combination of STE029 and Gefitinib effectively inhibited tumor development and progression compared to STE029 alone or Gefitinib alone, with significant difference (P<0.05) in PC9 and PC9/BB4 xenografted tumor.

CONCLUSIONS

STE029 could sensitize Gefitinib by inhibiting EGFR/PI3K/Akt pathway, blocking the tumor cell cycle and proliferation and inducing apoptosis through caspase-8 and caspase-9 dependent pathway. STE029 deserves further investigations in overcoming EGFR-TKI resistance in lung cancer.

Simvastatin in the Treatment of Colorectal Cancer: A Review

Drug repositioning and drug reuse are the heated topics in the field of oncology in recent years. These two concepts refer to seeking effective drugs for cancer that are not originally intended to treat cancer. The survival benefits are then analyzed by combining the re-positioned drugs with conventional cancer treatment methods. Simvastatin is a clinically commonly used hyperlipidemia drug and exerts the effect of preventing cardiovascular diseases. Recent studies have found that simvastatin has great potential in the treatment of colorectal cancer, and a large number of clinical studies have used simvastatin as an adjuvant drug to help treat metastatic colorectal cancer.

Cholesterol-Lowering Drugs on Akt Signaling for Prevention of Tumorigenesis

Cholesterol has been reported to be accumulated in cancer cells. The metabolic dysregulation of the cholesterol is associated with tumor development and progression. The cholesterol-lowering drugs have been found to be involved in the prevention and treatment of various cancers. Akt, a serine/threonine kinase, can modulate the role of several downstream proteins involved in cell proliferation, migration, invasion, metabolism, and apoptosis. Since its involvement in several signaling pathways, its dysregulation is commonly reported in several cancers. Thus, targeting Akt could be an effective approach for cancer prevention and therapy. Cholesterol-lowering drugs have been found to affect the expression of Akt, and its activation in the cancer cells and thus have shown anticancer activity in different type of cancers. These drugs act on various signaling pathways such as PTEN/Akt, PI3k/Akt, Akt/NF-κB, Akt/FOXO1, Akt/mTOR, etc., which will be discussed in this article. This review article will discuss the significance of cholesterol in cancer cells, cholesterol-lowering drugs, the role of Akt in cancer cells, and the effects of cholesterol-lowering drugs on Akt in the prevention of therapy resistance and metastasis.

Insights Into the Function and Clinical Application of HDAC5 in Cancer Management

Histone deacetylase 5 (HDAC5) is a class II HDAC. Aberrant expression of HDAC5 has been observed in multiple cancer types, and its functions in cell proliferation and invasion, the immune response, and maintenance of stemness have been widely studied. HDAC5 is considered as a reliable therapeutic target for anticancer drugs. In light of recent findings regarding the role of epigenetic reprogramming in tumorigenesis, in this review, we provide an overview of the expression, biological functions, regulatory mechanisms, and clinical significance of HDAC5 in cancer.

Local delivery of simvastatin maintains tooth anchorage during mechanical tooth moving via anti-inflammation property and AMPK/MAPK/NF-kB inhibition

Simvastatin (SMV) could increase tooth anchorage during orthodontic tooth movement (OTM). However, previous studies on its bone‐specific anabolic and anti‐inflammation properties were based on static in vitro and in vivo conditions. AMPK is a stress‐activated kinase that protects tissue against serious damage from overloading inflammation. Rat periodontal ligament cells (PDLCs) were subjected to a serial of SMV concentrations to investigate the optimization that promoted osteogenic differentiation. The PDLCs in static and/or tensile culturing conditions then received the proper concentration SMV. Related factors expression was measured by the protein array, real‐time PCR and Western blot. The 0.05UM SMV triggered osteogenic differentiation of PDLCs. The inhibition of AMPK activation through a pharmacological approach (Compound C) caused dramatic decrease in osteogenic/angiogenic gene expression and significant increase in inflammatory NF‐κB phosphorylation. In contrast, pharmacological activation of AMPK by AICAR significantly inhibited inflammatory factors expression and activated ERK1/2, P38 MAPK phosphorylation. Moreover, AMPK activation induced by SMV delivery significantly attenuated the osteoclastogenesis and decreased the expression of pro‐inflammatory TNF‐α and NF‐κB in a rodent model of OTM. The current studies suggested that SMV could intrigue intrinsic activation of AMPK in PDLCs that promote attenuate the inflammation which occurred under tensile irritation through AMPK/MAPK/NF‐kB Inhibition.

Liposomal simvastatin sensitizes C26 murine colon carcinoma to the antitumor effects of liposomal 5-fluorouracil in vivo

5-Fluorouracil-based therapy remains the main approach in colorectal cancer, even though there are still some drawbacks, such as chemoresistance. In this study we combined 5-fluorouracil encapsulated in long-circulating liposomes with simvastatin, also encapsulated in long-circulating liposomes, that was previously proved to exert antitumor actions on the same tumor model. The production of angiogenic/inflammatory proteins was assessed by protein array and the production of markers for tumor aggressiveness (Bcl-2, Bax, and nuclear factor [NF]-κB) were determined by western blot analysis. Intratumor oxidative stress was evaluated through measurement of malondialdehyde level by HPLC, and through spectrophotometric analysis of catalytic activity of catalase and of total antioxidant capacity. Immunohistochemical analysis of tumors for CD31 expression was assessed. Intratumor activity of MMP-2 by gelatin zymography was also carried out. Our results revealed that combined therapies based on liposomal formulations exerted enhanced antitumor activities compared with combined treatment with free drugs. Sequential treatment with liposomal simvastatin and liposomal 5-fluorouracil showed the strongest antitumor activity in C26 colon carcinoma in vivo, mainly through inhibition of tumor angiogenesis. Important markers for cancer progression (Bcl-2, Bax, NF-κB, and intratumor antioxidants) showed that liposomal simvastatin might sensitize C26 cells to liposomal 5-fluorouracil treatment in both regimens tested. The outcome of simultaneous treatment with liposomal formulations was superior to sequential treatment with both liposomal types as the invasive capacity of C26 tumors was strongly increased after the latest treatment. The antitumor efficacy of combined therapy in C26 colon carcinoma might be linked to the restorative effects on proteins balance involved in tumor angiogenesis.

Mevalonate Pathway Provides Ubiquinone to Maintain Pyrimidine Synthesis and Survival in p53-Deficient Cancer Cells Exposed to Metabolic Stress

Oncogene activation and loss of tumor suppressor function changes the metabolic activity of cancer cells to drive unrestricted proliferation. Moreover, cancer cells adapt their metabolism to sustain growth and survival when access to oxygen and nutrients is restricted, such as in poorly vascularized tumor areas. We show here that p53-deficient colon cancer cells exposed to tumor-like metabolic stress in spheroid culture activated the mevalonate pathway to promote the synthesis of ubiquinone. This was essential to maintain mitochondrial electron transport for respiration and pyrimidine synthesis in metabolically compromised environments. Induction of mevalonate pathway enzyme expression in the absence of p53 was mediated by accumulation and stabilization of mature SREBP2. Mevalonate pathway inhibition by statins blocked pyrimidine nucleotide biosynthesis and induced oxidative stress and apoptosis in p53-deficient cancer cells in spheroid culture. Moreover, ubiquinone produced by the mevalonate pathway was essential for the growth of p53-deficient tumor organoids. In contrast, inhibition of intestinal hyperproliferation by statins in an Apc/KrasG12D-mutant mouse model was independent of de novo pyrimidine synthesis. Our results highlight the importance of the mevalonate pathway for maintaining mitochondrial electron transfer and biosynthetic activity in cancer cells exposed to metabolic stress. They also demonstrate that the metabolic output of this pathway depends on both genetic and environmental context. SIGNIFICANCE: These findings suggest that p53-deficient cancer cells activate the mevalonate pathway via SREBP2 and promote the synthesis of ubiquinone that plays an essential role in reducing oxidative stress and supports the synthesis of pyrimidine nucleotide.

Greasing the Wheels of the Cancer Machine: The Role of Lipid Metabolism in Cancer

Altered lipid metabolism is among the most prominent metabolic alterations in cancer. Enhanced synthesis or uptake of lipids contributes to rapid cancer cell growth and tumor formation. Lipids are a highly complex group of biomolecules that not only constitute the structural basis of biological membranes but also function as signaling molecules and an energy source. Here, we summarize recent evidence implicating altered lipid metabolism in different aspects of the cancer phenotype and discuss potential strategies by which targeting lipid metabolism could provide a therapeutic window for cancer treatment.

Repurposing old drugs as new inhibitors of the ubiquitin-proteasome pathway for cancer treatment

The ubiquitin-proteasome system (UPS) plays a central role in the degradation of cellular proteins. Targeting protein degradation has been validated as an effective strategy for cancer therapy since 2003. Several components of the UPS have been validated as potential anticancer targets, including 20S proteasomes, 19S proteasome-associated deubiquitinases (DUBs) and ubiquitin ligases (E3s). 20S proteasome inhibitors (such as bortezomib/BTZ and carfilzomib/CFZ) have been approved by the U.S. Food and Drug Administration (FDA) for the treatment of multiple myeloma (MM) and some other liquid tumors. Although survival of MM patients has been improved by the introduction of BTZ-based therapies, these clinical 20S proteasome inhibitors have several limitations, including emergence of resistance in MM patients, neuro-toxicities, and little efficacy in solid tumors. One of strategies to improve the current status of cancer treatment is to repurpose old drugs with UPS-inhibitory properties as new anticancer agents. Old drug reposition represents an attractive drug discovery approach compared to the traditional de novo drug discovery process which is time-consuming and costly. In this review, we summarize status of repurposed inhibitors of various UPS components, including 20S proteasomes, 19S-associated DUBs, and ubiquitin ligase E3s. The original and new mechanisms of action, molecular targets, and potential anticancer activities of these repurposed UPS inhibitors are reviewed, and their new uses including combinational therapies for cancer treatment are discussed.

A Single Arm, Phase II Study of Simvastatin Plus XELOX and Bevacizumab as First-Line Chemotherapy in Metastatic Colorectal Cancer Patients

Purpose

Simvastatin has demonstrated anti-tumor activity in preclinical studies via tumor cell senescence, apoptosis, and anti-angiogenesis. This phase II trial evaluated the efficacy and toxicity profile of conventional XELOX and bevacizumab chemotherapy plus simvastatin in metastatic colorectal cancer patients (MCRC).

Materials and Methods

Patients with MCRC received first-line XELOX in 3-week treatment cycles of intravenous oxaliplatin 130 mg/m² plus bevacizumab 7.5 mg/kg (day 1), followed by oral capecitabine 1,000 mg/m² twice daily (day 1-14). Simvastatin 80 mg tablets were taken orally once daily every day during the period of chemotherapy. The primary endpoint was progression-free survival (PFS). Secondary endpoints were response rate, duration of response, overall survival (OS), time to progression, and toxicity.

Results

From January 2014 to April 2015, 60 patients were enrolled and 55 patients were evaluable for tumor response. The median follow-up duration was 30.1 months (range, 28.5 to 31.7 months). The median PFS was 10.4 months (95% confidence interval [CI], 9.6 to 11.1). The median OS of all patients was 19.0 months (95% CI, 11.9 to 26.0). The disease-control rate and overall response rate were 88.3% (95% CI, 74 to 96) and 58.3% (95% CI, 44 to 77), respectively, by intent-to-treat protocol analysis. There was one complete response and 34 partial responses. One patient experienced grade 3 creatine kinase elevation and liver enzyme elevation.

Conclusion

Based on the current study, the addition of 80 mg simvastatin to XELOX and bevacizumab showed comparable clinical efficacy in patients with MCRC as first-line chemotherapy and did not increase toxicity.

The Effect of Statin Added to Systemic Anticancer Therapy: A Meta-Analysis of Randomized, Controlled Trials

Preclinical studies have demonstrated that statins have anticancer properties and act in an additive or synergistic way when combined with anticancer therapy. We conducted this meta-analysis of randomized, controlled phase II or III trials to evaluate the effect of statins added to systemic anticancer therapy in patients with solid cancer. A systematic literature search was performed to identify all randomized trials that were designed to investigate the effect of statins in patients with cancer using PubMed, EMBASE, Google Scholar, and Web of Science (up to August 2018). From eight randomized controlled trials, 1760 patients were included in the pooled analyses of odds ratios (ORs) with 95% confidence intervals (CIs) for grade 3–5 adverse events (AEs) and overall response rate (ORR) and hazard ratios (HRs) with 95% CIs for progression-free survival (PFS) and overall survival (OS). The addition of statin to anticancer agents did not significantly increase the incidence of grade 3–5 AEs (OR = 1.03, 95% CI: 0.81–1.29, p = 0.78). However, the combination of statin and anticancer agents did not improve ORR (OR = 0.96, 95% CI: 0.77–1.20, p = 0.72) compared with that of anticancer therapy alone. In addition, statins added to systemic anticancer therapy failed to prolong PFS (HR = 0.99, 95% CI: 0.90–1.10, p = 0.92) and OS (HR = 0.91, 95% CI: 0.76–1.11, p = 0.52). In conclusion, this meta-analysis of randomized controlled trials does not support clinical benefits of statins added to systemic anticancer therapy in patients with solid cancer.

The prognostic significance of the expression of monocarboxylate transporter 4 in patients with right- or left-sided colorectal cancer

AIM

Monocarboxylate transporter 4 (MCT4) is a proton pump that exchanges lactate through the plasma membrane. The present study investigated the clinical significance of the expression of MCT4 in patients with right- or left-sided colorectal cancer (CRC).

METHODS

Surgical specimens from 237 CRC patients were immunohistochemically stained with polyclonal anti-MCT4 antibodies. The relationships among the MCT4 expression, the clinicopathological factors, and the prognosis were evaluated.

RESULTS

Thirty-six (62.1%) of 58 patients with right-sided CRC and 95 (53.1%) of 179 patients with left-sided CRC showed the high expression of MCT4. The MCT4 expression was significantly correlated with gender and lymph node metastasis in patients with right-sided CRC, and size, depth of invasion, distant metastasis, and tumor-node-metastasis stage in patients with left-sided CRC. A univariate analysis demonstrated that the expression of MCT4 was a significant prognostic factor in both right- and left-sided CRC patients. A multivariate analysis demonstrated the expression of MCT4 was a significantly independent prognostic factor in patients with left-sided CRC, but not in those with right-sided CRC.

CONCLUSIONS

Our results suggest that the high expression of MCT4 is a useful marker for tumor progression and a poor prognosis in CRC patients, especially those with left-sided CRC.

The poor design of clinical trials of statins in oncology may explain their failure - Lessons for drug repurposing

Statins are widely used to treat hypercholesterolaemia. However, by inhibiting the production of mevalonate, they also reduce the production of several isoprenoids that are necessary for the function of small GTPase oncogenes such as Ras. As such, statins offer an attractive way to inhibit an "undruggable" target, suggesting that they may be usefully repurposed to treat cancer. However, despite numerous studies, there is still no consensus whether statins are useful in the oncology arena. Numerous preclinical studies have provided evidence justifying the evaluation of statins in cancer patients. Some retrospective studies of patients taking statins to control cholesterol have identified a reduced risk of cancer mortality. However, prospective clinical studies have mostly not been successful. We believe that this has occurred because many of the prospective clinical trials have been poorly designed. Many of these trials have failed to take into account some or all of the factors identified in preclinical studies that are likely to be necessary for statins to be efficacious. We suggest an improved trial design which takes these factors into account. Importantly, we suggest that the design of clinical trials of drugs which are being considered for repurposing should not assume it is appropriate to use them in the same way as they are used in their original indication. Rather, such trials deserve to be informed by preclinical studies that are comparable to those for any novel drug.

Omega-3 fatty acids, membrane remodeling and cancer prevention

Proteins are often credited as the macromolecule responsible for performing critical cellular functions, however lipids have recently garnered more attention as our understanding of their role in cell function and human health becomes more apparent. Although cellular membranes are the lipid environment in which many proteins function, it is now apparent that protein and lipid assemblies can be organized to form distinct micro- or nanodomains that facilitate signaling events. Indeed, it is now appreciated that cellular function is partly regulated by the specific spatiotemporal lipid composition of the membrane, down to the nanosecond and nanometer scale. Furthermore, membrane composition is altered during human disease processes such as cancer and obesity. For example, an increased rate of lipid/cholesterol synthesis in cancerous tissues has long been recognized as an important aspect of the rewired metabolism of transformed cells. However, the contribution of lipids/cholesterol to cellular function in disease models is not yet fully understood. Furthermore, an important consideration in regard to human health is that diet is a major modulator of cell membrane composition. This can occur directly through incorporation of membrane substrates, such as fatty acids, e.g., n-3 polyunsaturated fatty acids (n-3 PUFA) and cholesterol. In this review, we describe scenarios in which changes in membrane composition impact human health. Particular focus is placed on the importance of intrinsic lipid/cholesterol biosynthesis and metabolism and extrinsic dietary modification in cancer and its effect on plasma membrane properties.

Marketed drugs used for the management of hypercholesterolemia as anticancer armament

The design of novel pharmacologic agents as well as their approval for sale in markets all over the world is a tedious and pricey process. Inevitably, oncologic patients commonly experience unwanted effects of new anticancer drugs, while the acquisition of clinical experience for these drugs is largely based on doctor–patient partnership which is not always effective. The repositioning of marketed non-antineoplastic drugs that hopefully exhibit anticancer properties into the field of oncology is a challenging option that gains ground and attracts preclinical and clinical research in an effort to override all these hindrances and minimize the risk for reduced efficacy and/or personalized toxicity. This review aims to present the anticancer properties of drugs used for the management of hypercholesterolemia. A global view of the antitumorigenicity of all marketed antihypercholesterolemic drugs is of major importance, given that atherosclerosis, which is etiologically linked to hypercholesterolemia, is a leading worldwide cause of morbidity and mortality, while hypercholesterolemia and tumorigenesis are known to be interrelated. In vitro, in vivo and clinical literature data accumulated so far outline the mechanistic basis of the antitumor function of these agents and how they could find application at the clinical setting.

Dietary geranylgeraniol can limit the activity of pitavastatin as a potential treatment for drug-resistant ovarian cancer

Pre-clinical and retrospective studies of patients using statins to reduce plasma cholesterol have suggested that statins may be useful to treat cancer. However, prospective clinical trials have yet to demonstrate significant efficacy. We have previously shown that this is in part because a hydrophobic statin with a long half-life is necessary. Pitavastatin, the only statin with this profile, has not undergone clinical evaluation in oncology. The target of pitavastatin, hydroxymethylglutarate coenzyme-A reductase (HMGCR), was found to be over-expressed in all ovarian cancer cell lines examined and upregulated by mutated TP53, a gene commonly altered in ovarian cancer. Pitavastatin-induced apoptosis was blocked by geranylgeraniol and mevalonate, products of the HMGCR pathway, confirming that pitavastatin causes cell death through inhibition of HMGCR. Solvent extracts of human and mouse food were also able to block pitavastatin-induced apoptosis, suggesting diet might influence the outcome of clinical trials. When nude mice were maintained on a diet lacking geranylgeraniol, oral pitavastatin caused regression of Ovcar-4 tumour xenografts. However, when the animal diet was supplemented with geranylgeraniol, pitavastatin failed to prevent tumour growth. This suggests that a diet containing geranylgeraniol can limit the anti-tumour activity of pitavastatin and diet should be controlled in clinical trials of statins.

Inhibiting HDAC1 Enhances the Anti-Cancer Effects of Statins through Downregulation of GGTase-Iβ Expression

Hydroxy-methyl-glutaryl-coenzyme A (HMG-CoA) reductase inhibitors, namely statins, are potential anti-tumor agents. Previously, we showed that a pan-histone deacetylase (HDAC) inhibitor enhances the anti-tumor effects of the HMG-CoA inhibitor. However, the underlying mechanisms were not fully understood. Cancer cell lines (CAL-27 and SACC-83) were exposed to pan-HDAC inhibitor, or HDAC1 inhibitor, or geranylgeranyl transferase type I (GGTase-I) inhibitor alone or in combination with statin. Cell viability, apoptosis, migration, and invasion were assessed by Cell Count Kit-8, 4′,6-diamidino-2-phenylindole staining, and transwell assay, respectively. A xenograft model was used for assessing tumor growth in vivo. Western blot and real-time PCR were used to assess the expression of genes. We observed that inhibiting HDAC1 could enhance the anti-tumor effects of statins both in vitro and in vivo. Inhibiting HDAC1 blocked the statin-induced upregulation of geranylgeranyl transferase type Iβ subunit (GGTase-Iβ), resulting in an enhancement of the anti-cancer effects of statin. Overexpression of GGTase-Iβ or constitutively active RhoA abolished the enhancement by inhibiting HDAC1 on anti-tumor effects of statins. The HDAC1 inhibitor failed to enhance cytotoxicity in non-tumor primary cells treated with statin. Inhibiting HDAC1 enhanced the anti-cancer effects of statins through downregulation of GGTase-Iβ expression, and thus further inactivation of RhoA. A combination of statin with HDAC1 or GGTase-I inhibitor would be a new strategy for cancer chemotherapy.

Simvastatin suppresses the DNA replication licensing factor MCM7 and inhibits the growth of tamoxifen-resistant breast cancer cells

Acquired tamoxifen resistance (TamR) remains a major challenge in breast cancer endocrine therapy. The mechanism of acquiring tamoxifen resistance remains elusive, and no effective drugs are available. In this investigation, we determined that the expression of the DNA damage marker γH2AX is upregulated under minichromosome maintenance protein 7 (MCM7) knockdown in phospho Ser807/811-retinoblastoma protein (p-Rb) defect cells. In addition, the expression of p-Rb was lower in TamR cells than in parental cells, and the expression of γH2AX was significantly upregulated when MCM7 was knocked down in TamR cells. Simvastatin, an agent for hypercholesterolemia treatment, activated the MCM7/p-RB/γH2AX axis and induced DNA damage in TamR cells, especially when combined with tamoxifen. Finally, in vitro and in vivo experiments demonstrated that simvastatin combined with tamoxifen increased TamR cell apoptosis and inhibited xenograft growth. In conclusion, simvastatin may suppress TamR cell growth by inhibiting MCM7 and Rb and subsequently inducing DNA damage.

Determining the optimal 5-FU therapeutic dosage in the treatment of colorectal cancer patients

Fluorouracil (5-FU) has been wildly used as a primary medication in the treatment of solid tumors including colorectal cancer. The treatment efficacy and toxicity of 5-FU varies greatly among individuals, suggesting a need for individualized regimen for cancer patients. The present study analyzed the blood concentration of 5-FU and its therapeutic efficacy and toxicity, evaluated the relationship of AUC (area under the plasma concentration-time curve), and the protein expression of DPD (dihydropyrimidine dehydrogenase) and TS (thymidylate synthetase), and therapeutic efficacy and toxicity. It was found that the AUC of 5-FU was 34.16±14.83mgmg·h/L in this cohort of study. The immunohistochemical analysis revealed 38.96% and 81.82% positive staining for DPD and TS in colorectal cancer tissues, respectively. We demonstrated that the expression of TS is positively correlated with the expression of DPD. There was a positive correlation between AUC and therapeutic efficacy, and gastrointestinal tract and neural toxicity. The expression of neither DPD nor TS had significant correlations with therapeutic efficacy and toxicity. Based on the blood 5-FU concentration and its relationship with treatment efficacy and toxicity, we determined an optimal therapeutic dosage of 5-FU to be equivalent to an AUC=28.03-38.94mgmg·h/L. Our study will be helpful in providing an individualized medical regimen for the treatment of colorectal cancer patients.

The HMG-CoA reductase inhibitor, simvastatin, exhibits anti-metastatic and anti-tumorigenic effects in ovarian cancer

Ovarian cancer is the 5th leading cause of cancer death among women in the United States. The mevalonate pathway is thought to be a potential oncogenic pathway in the pathogenesis of ovarian cancer. Simvastatin, a 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCR) inhibitor, is a widely used drug for inhibiting the synthesis of cholesterol and may also have anti-tumorigenic activity. Our goal was to evaluate the effects of simvastatin on ovarian cancer cell lines, primary cultures of ovarian cancer cells and in an orthotopic ovarian cancer mouse model. Simvastatin significantly inhibited cellular proliferation, induced cell cycle G1 arrest and apoptosis, and caused cellular stress via reduction in the enzymatic activity of HMGCR and inhibition of the MAPK and mTOR pathways in ovarian cancer cells. Furthermore, simvastatin induced DNA damage and reduced cell adhesion and invasion. Simvastatin also exerted anti-proliferative effects on primary cell cultures of ovarian cancer. Treatment with simvastatin in an orthotopic mouse model reduced ovarian tumor growth, coincident with decreased Ki-67, HMGCR, phosphorylated-Akt and phosphorylated-p42/44 protein expression. Our findings demonstrate that simvastatin may have therapeutic benefit for ovarian cancer treatment and be worthy of further exploration in clinical trials.

Simvastatin increases the antineoplastic actions of paclitaxel carried in lipid nanoemulsions in melanoma-bearing mice

PURPOSE

Lipid nanoemulsions (LDEs) that bind to low-density lipoprotein (LDL) receptors used as carriers of paclitaxel (PTX) can decrease toxicity and increase PTX antitumoral action. The administration of simvastatin (Simva), which lowers LDL-cholesterol, was tested as an adjuvant to commercial PTX and to PTX associated with LDE (LDE-PTX).

MATERIALS AND METHODS

B16F10 melanoma-bearing mice were treated with saline solution or LDE (controls), Simva, PTX, PTX and Simva, LDE-PTX, and LDE-PTX and Simva: PTX dose 17.5 μmol/kg (three intraperitoneal injections, 3 alternate days): Simva 50 mg/kg/day by gavage, 9 consecutive days.

RESULTS

Compared with saline controls, 95% tumor-growth inhibition was achieved by LDE-PTX and Simva, 61% by LDE-PTX, 44% by PTX and Simva, and 43% by PTX. Simva alone had no effect. Metastasis developed in only 37% of the LDE-PTX and Simva, 60% in LDE-PTX, and 90% in PTX and Simva groups. Survival rates were higher in LDE-PTX and Simva and in LDE-PTX groups. The LDE-PTX and Simva group presented tumors with reduced cellular density and increased collagen fibers I and III. Tumors from all groups showed reduction in immunohistochemical expression of ICAM, MCP-1, and MMP-9; LDE-PTX and Simva presented the lowest MMP-9 expression. Expression of p21 was increased in the Simva, LDE-PTX, and LDE-PTX and Simva groups. In the Simva and LDE-PTX and Simva groups, expression of cyclin D1, a proliferation and survival promoter of tumor cells, was decreased. Therapy with LDE-PTX and Simva showed negligible toxicity compared with PTX and Simva, which resulted in weight loss and myelosuppression.

CONCLUSION

Simva increased the antitumor activity of PTX carried in LDE but not of PTX commercial presentation, possibly because statins increase the expression of LDL receptors that internalize LDE-PTX.

Statin and Metformin Use Prolongs Survival in Patients With Resectable Pancreatic Cancer

OBJECTIVES

The aim of this study was to investigate the impact of statin and metformin therapy on disease outcome for patients with pancreatic ductal adenocarcinoma (PDAC).

METHODS

This retrospective study included 171 PDAC patients who underwent surgical resection at the Stanford Cancer Institute between 1998 and 2013. No patients received neoadjuvant therapy. Statin and metformin use was defined as use during initial consult and continuing upon discharge from the hospital after surgery. Dose of each medication was recorded, as was the type of statin taken.

RESULTS

The median follow-up for all patients was 11.23 months (range, 0.2-105.0 months). Among the 171 patients included in our analysis, 18 patients (10.5%) took metformin and 34 patients (19.9%) took statins. Statin use was associated with better overall survival (OS) in patients with PDAC (P = 0.011). Metformin use was also associated with better OS (P = 0.035). The use of statins remained significant on multivariate analysis for OS (P = 0.014; hazards ratio, 0.33; 95% confidence interval, 0.139-0.799), but metformin use did not (P = 0.33; hazards ratio 0.60, 95% confidence interval, 0.211-1.675).

CONCLUSIONS

Statin and metformin use is associated with improved OS in patients with resectable PDAC. These medications should be further investigated for possible long-term use in the general population.

A randomised, double-blind, placebo-controlled multi-centre phase III trial of XELIRI/FOLFIRI plus simvastatin for patients with metastatic colorectal cancer

Background:

The purpose of this randomised phase III trial was to evaluate whether the addition of simvastatin, a synthetic 3-hydroxy-3methyglutaryl coenzyme A reductase inhibitor, to XELIRI/FOLFIRI chemotherapy regimens confers a clinical benefit to patients with previously treated metastatic colorectal cancer.

Methods:

We undertook a double-blind, placebo-controlled phase III trial of 269 patients previously treated for metastatic colorectal cancer and enrolled in 5 centres in South Korea. Patients were randomly assigned (1 : 1) to one of the following groups: FOLFIRI/XELIRI plus simvastatin (40 mg) or FOLFIRI/XELIRI plus placebo. The FOLFIRI regimen consisted of irinotecan at 180 mg m⁻² as a 90-min infusion, leucovorin at 200 mg m⁻² as a 2-h infusion, and a bolus injection of 5-FU 400 mg m⁻² followed by a 46-h continuous infusion of 5-FU at 2400 mg m⁻². The XELIRI regimen consisted of irinotecan at 250 mg m⁻² as a 90-min infusion with capecitabine 1000 mg m⁻² twice daily for 14 days. The primary end point was progression-free survival (PFS). Secondary end points included response rate, duration of response, overall survival (OS), time to progression, and toxicity.

Results:

Between April 2010 and July 2013, 269 patients were enrolled and assigned to treatment groups (134 simvastatin, 135 placebo). The median PFS was 5.9 months (95% CI, 4.5–7.3) in the XELIRI/FOLFIRI plus simvastatin group and 7.0 months (95% CI, 5.4–8.6) in the XELIRI/FOLFIRI plus placebo group (P=0.937). No significant difference was observed between the two groups with respect to OS (median, 15.9 months (simvastatin) vs 19.9 months (placebo), P=0.826). Grade ⩾3 nausea and anorexia were noted slightly more often in patients in the simvastatin arm compared with with the placebo arm (4.5% vs 0.7%, 3.0% vs 0%, respectively).

Conclusions:

The addition of 40 mg simvastatin to the XELIRI/FOLFIRI regimens did not improve PFS in patients with previously treated metastatic colorectal cancer nor did it increase toxicity.

Safety and efficacy of the addition of simvastatin to cetuximab in previously treated KRAS mutant metastatic colorectal cancer patients

Introduction Cetuximab is registered for use in colorectal cancer (CRC) patients with RAS wild-type tumours only. Simvastatin blocks the mevalonate pathway and thereby interferes with the post-translational modification (prenylation) of KRAS. We hypothesize that the activitated KRAS pathway in KRAS mutant tumors can be inhibited by simvastatin rendering these tumors sensitive to the EGFR inhibitor cetuximab. Methods A Simon two-stage, single-arm, phase II study was performed to test the efficacy and safety of the addition of simvastatin to cetuximab in patients with a KRAS mutation in their CRC tumour who were previously treated with fluoropyrimidine, oxaliplatin and irinotecan based regimens. The primary endpoint was to test the percentage of patients alive and free from progression 12.5 weeks after the first administration of cetuximab. Our hypothesis was that at least 40 % was free from progression, comparable to, though slightly lower than in KRAS wild-type patients. Results Four of 18 included patients (22.2 %) were free from progression at the primary endpoint time. The time to progression in these 4 patients ranged from 20.3 to 47 weeks. Conclusion Based on the current study we conclude that the theoretical concept of KRAS modulation with simvastatin was not applicable in the clinic, as we were not able to restore sensitivity to cetuximab in CRC patients harbouring a somatic KRAS mutation.

Prognostic Significance of Statin Use in Colorectal Cancer: A Systematic Review and Meta-Analysis

Statin intake has been reported to reduce the risk of several malignancies beyond its cholesterol-lowering effects. However, little is known regarding the survival benefit of statins for patients with colorectal cancer (CRC).We conducted a systematic literature search of multiple databases for studies published before November 2014, which investigated associations between statin intake and CRC prognosis. Meta-analysis was performed using random-effects model. The primary outcomes of interest were all-cause mortality (ACM) and cancer-specific mortality (CSM).Ten studies involving 76,851 patients were eligible for this meta-analysis, with 7 studies investigating prediagnosis statin use and 5 studies reporting postdiagnosis statin use. Prediagnosis statin use was associated with reduced ACM (hazard ratio [HR] 0.73, 95% confidence interval [CI] 0.61-0.88, P = 0.001) and CSM (HR 0.80, 95% CI 0.77-0.84, P < 0.001) for patients with CRC. This effect persisted when stratified by tumor site and in studies adjusted by nonsteroidal anti-inflammatory drug use. In addition, postdiagnosis statin use was associated with decreased CSM (HR 0.70, 95% CI 0.60-0.82, P < 0.001). However, we did not note reduced ACM for postdiagnosis statin use (HR 0.93, 95% CI 0.68-1.27, P = 0.639). There appeared to be an association between postdiagnosis statin use and increased ACM in KRAS-mutated CRC.Our findings provide evidence that prediagnosis statin therapy was associated with reduced ACM and CSM in CRC patients; postdiagnosis statin therapy indicated decreased CSM. However, findings may not apply to patients with postdiagnosis statin therapy for ACM. Further studies are warranted to determine the relation between statin dose and duration on CRC survival.

Statins are potential anticancerous agents (review)

Statins are inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), which is a rate-limiting enzyme in the mevalonate pathway. The pleiotropic effects of statins may be mediated by the inhibition of downstream products such as small GTP-binding proteins, Rho, Ras and Rac whose localization and function are dependent on isoprenylation. Preclinical studies of statins in different cancer cell lines and animal models showed antiproliferative, pro‑apoptotic and anti-invasive effects. Notably, statins showed targeted action in cancerous cell lines compared to normal cells. Previous studies have also shown the synergistic effects of statins with chemotherapeutic agents and radiotherapy. This effect of statins was also observed in chemotherapeutic-resistant tumors. Statins were reported to sensitize the cells to radiation by arresting them in the late G1 phase of the cell cycle. Similarly, population-based studies also demonstrated a chemopreventive and survival benefit of statins in various types of cancers. However, this benefit has yet to be proven in clinical trials. The inter-individual variation in response to statins may be contributed to many genetic and non-genetic factors, including single-nucleotide polymorphisms in HMGCR gene and the overexpression of heterogeneous nuclear ribonucleoprotein A1, which was reported to reduce HMGCR enzyme activity. However, more studies with large phase III randomized controlled trials in cancer patients should be conducted to establish the effect of stains in cancer prevention and treatment.

DCDB 2.0: a major update of the drug combination database

Experience in clinical practice and research in systems pharmacology suggested the limitations of the current one-drug-one-target paradigm in new drug discovery. Single-target drugs may not always produce desired physiological effects on the entire biological system, even if they have successfully regulated the activities of their designated targets. On the other hand, multicomponent therapy, in which two or more agents simultaneously interact with multiple targets, has attracted growing attention. Many drug combinations consisting of multiple agents have already entered clinical practice, especially in treating complex and refractory diseases. Drug combination database (DCDB), launched in 2010, is the first available database that collects and organizes information on drug combinations, with an aim to facilitate systems-oriented new drug discovery. Here, we report the second major release of DCDB (Version 2.0), which includes 866 new drug combinations (1363 in total), consisting of 904 distinctive components. These drug combinations are curated from ∼140,000 clinical studies and the food and drug administration (FDA) electronic orange book. In this update, DCDB collects 237 unsuccessful drug combinations, which may provide a contrast for systematic discovery of the patterns in successful drug combinations. Database URL: http://www.cls.zju.edu.cn/dcdb/

Statin use is not associated with improved progression free survival in cetuximab treated KRAS mutant metastatic colorectal cancer patients: results from the CAIRO2 study

Statins may inhibit the expression of the mutant KRAS phenotype by preventing the prenylation and thus the activation of the KRAS protein. This study was aimed at retrospectively evaluating the effect of statin use on outcome in KRAS mutant metastatic colorectal cancer patients (mCRC) treated with cetuximab. Treatment data were obtained from patients who were treated with capecitabine, oxaliplatin bevacizumab ± cetuximab in the phase III CAIRO2 study. A total of 529 patients were included in this study, of whom 78 patients were on statin therapy. In patients with a KRAS wild type tumor (n = 321) the median PFS was 10.3 vs. 11.4 months for non-users compared to statin users and in patients with a KRAS mutant tumor (n = 208) this was 7.6 vs. 6.2 months, respectively. The hazard ratio (HR) for PFS for statin users was 1.12 (95% confidence interval 0.78-1.61) and was not influenced by treatment arm, KRAS mutation status or the KRAS*statin interaction. Statin use adjusted for covariates was not associated with increased PFS (HR = 1.01, 95% confidence interval 0.71-1.54). In patients with a KRAS wild type tumor the median OS for non-users compared to statin users was 22.4 vs. 19.8 months and in the KRAS mutant tumor group the OS was 18.1 vs. 14.5 months. OS was significantly shorter in statin users versus non-users (HR = 1.54; 95% confidence interval 1.06-2.22). However, statin use, adjusted for covariates was not associated with increased OS (HR = 1.41, 95% confidence interval 0.95-2.10). In conclusion, the use of statins at time of diagnosis was not associated with an improved PFS in KRAS mutant mCRC patients treated with chemotherapy and bevacizumab plus cetuximab.

Simvastatin plus capecitabine-cisplatin versus placebo plus capecitabine-cisplatin in patients with previously untreated advanced gastric cancer: a double-blind randomised phase 3 study

PURPOSE

We aimed to the addition of synthetic 3-hydroxy-3-methyglutaryl coenzyme A (HMG-CoA) reductase inhibitor, simvastatin to capecitabine-cisplatin (XP) in patients with previously untreated advanced gastric cancer (AGC).

METHODS

In this double-blind, placebo-controlled, phase III study, we enrolled patients aged 18 years or older with histological or cytological confirmed metastatic adenocarcinoma of the stomach or gastroesophageal junction (GEJ) at nine centres in Korea. Patients, stratified by disease measurability and participating site, were randomly assigned (1:1) to receive capecitabine 1000mg/m(2) twice daily for 14 days and cisplatin 80 mg/m(2) on day 1 every 3 weeks plus either simvastatin 40 mg or placebo, once daily. Cisplatin was given for 8 cycles; capecitabine and simvastatin were administered until disease progression or unacceptable toxicities. This study is registered with ClinicalTrials.gov, number NCT01099085.

RESULTS

Between February 2009 and November 2012, 244 patients were enrolled and assigned to treatment groups (120 simvastatin, 124 placebo). Median progression free survival (PFS) for 120 patients allocated XP plus simvastatin was 5.2 months (95% confidence interval (CI) 4.3-6.1) compared with 4.63 months (95% CI 3.5-5.7) for 124 patients who were allocated to XP plus placebo (hazard ratio 0.930, 95% CI 0.684-1.264; p=0.642). 63 (52.5%) of 120 patients in simvastatin group and 70 (56.4%) of 124 had grade 3 or higher adverse events.

CONCLUSIONS

Addition of 40 mg simvastatin to XP does not increase PFS in our trial, although it does not increase toxicity. Low dose of simvastatin (40 mg) to chemotherapy is not recommended in untargeted population with AGC.

Statins, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, potentiate the anti-angiogenic effects of bevacizumab by suppressing angiopoietin2, BiP, and Hsp90α in human colorectal cancer

Background:

Statins, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, are commonly prescribed because of their therapeutic and preventive effects on cardiovascular diseases. Even though they have been occasionally reported to have antitumour activity, it is unknown whether statins have anti-angiogenic effect in human colorectal cancer (CRC).

Methods:

A total of 11 human CRC cell lines were used to test the effects of bevacizumab, statins, and bevacizumab plus statins on human umbilical vein endothelial cell (HUVEC) viability and invasion in vitro. To determine the molecular mechanism of statins as anti-angiogenic agents, we performed an angiogenesis antibody array and proteomics analysis and confirmed the results using immunoblot assay, HUVEC invasion rescue assay, and siRNA assay. The antitumoural effects of bevacizumab and statins were evaluated in xenograft models.

Results:

A conventional dose of statins (simvastatin 0.2 μM, lovastatin 0.4 μM, atorvastatin 0.1 μM, and pravastatin 0.4 μM) in combination with bevacizumab directly reduced the cell viability, migration, invasion, and tube formation of HUVECs. The culture media of the CRC cells treated with bevacizumab or statins were also found to inhibit HUVEC invasion by suppressing angiogenic mediators, such as angiopoietin2, binding immunoglobulin protein (BiP), and Hsp90α. The combined treatment with bevacizumab and simvastatin significantly reduced the growth and metastases of xenograft tumours compared with treatment with bevacizumab alone.

Conclusions:

The addition of simvastatin at a dose used in patients with cardiovascular diseases (40–80 mg once daily) may potentiate the anti-angiogenic effects of bevacizumab on CRC by suppressing angiopoietin2, BiP, and Hsp90α in cancer cells. A clinical trial of simvastatin in combination with bevacizumab in patients with CRC is needed.

Simvastatin, an HMG-CoA reductase inhibitor, exhibits anti-metastatic and anti-tumorigenic effects in endometrial cancer

OBJECTIVE

Our goal was to evaluate the effects of simvastatin on endometrial cancer cell lines and primary cultures of endometrial cancer cells.

METHODS

Cell proliferation in the ECC-1 and Ishikawa endometrial cancer cell lines and primary cultures of endometrial cancer cells was assessed by MTT assay. Apoptosis and cell cycle were detected by Annexin V assay and propidium iodide staining, respectively. Reactive oxygen species and cell adhesion were assessed using ELISA assays. Invasion was analyzed using a transwell invasion assay. Mitochondrial DNA damage was confirmed using qPCR. The effects of simvastatin on the AKT/mTOR and MAPK pathways were determined by Western blotting.

RESULTS

Simvastatin inhibited cell proliferation in a dose-dependent manner in both endometrial cancer cell lines and 5/8 primary cultures of endometrial cancer cells. Simvastatin treatment resulted in G1 cell cycle arrest, a reduction in the enzymatic activity of HMG-CoA, induction of apoptosis as well as DNA damage and cellular stress. Treatment with simvastatin resulted in inhibition of the MAPK pathway and exhibited differential effects on the AKT/mTOR pathway in the ECC-1 and Ishikawa cells. Minimal change in AKT phosphorylation was seen in both cell lines. An increase in phosphorylated S6 was seen in ECC-1 and a decrease was seen in Ishikawa. Treatment with simvastatin reduced cell adhesion and invasion (p<0.01) in both cell lines.

CONCLUSION

Simvastatin had significant anti-proliferative and anti-metastatic effects in endometrial cancer cells, possibly through modulation of the MAPK and AKT/mTOR pathways, suggesting that statins may be a promising treatment strategy for endometrial cancer.

Statins inhibit tumor progression via an enhancer of zeste homolog 2-mediated epigenetic alteration in colorectal cancer

While statin intake has been proven to reduce the risk of colorectal cancer (CRC), the mechanism of antitumor effects and clinical significance in survival benefits remain unclear. Statin-induced antiproliferative effects and its underlying mechanism were examined using six CRC cell lines. Statins except pravastatin showed antiproliferative effects (simvastatin ≥ fluvastatin > atorvastatin) even though both of simvastatin and pravastatin could activate mevalonate pathways, suggesting the statin-mediated antiproliferative effects depended on non-mevalonate pathway. Indeed, statin induced p27(KIP1) expression by downregulation of histone methyltransferase enhancer of zeste homolog 2 (EZH2), which acts as an epigenetic gene silencer. Additionally, the use of simvastatin plus classII histone deacetylase (HDAC) inhibitor (MC1568) induced further overexpression of p27(KIP1) by inhibiting HDAC5 induction originated from downregulated EZH2 in CRC cells and synergistically led to considerable antiproliferative effects. In the clinical setting, Statin intake (except pravastatin) displayed the downregulated EZH2 expression and inversely upregulated p27(KIP1) expression in the resected CRC by immunohistochemical staining and resulted in the significantly better prognoses both in overall survival (p = 0.02) and disease free survival (p < 0.01) compared to patients without statin intake. Statins may inhibit tumor progression via an EZH2-mediated epigenetic alteration, which results in survival benefits after resected CRC. Furthermore, statin plus classII HDAC inhibitor could be a novel anticancer therapy by their synergistic effects in CRC.

Statins: perspectives in cancer therapeutics

Virtually any cell type in a mammalian organism uses Acetyl CoA to yield mevalonate, through the activity of the 3-hydroxy-3-methyl-glutaryl-CoA reductase enzyme and, ultimately, cholesterol. Statins have long and quite successfully been used as cholesterol lowering drugs. They reversibly inhibit the 3-hydroxy-3-methyl-glutaryl-CoA reductase activity, which is rate limiting in the early steps of the cholesterol synthesis pathway. In addition to these effects, it has also been amply shown that statins may efficiently trigger cancer cell apoptosis, making them a plausible therapeutic option for the treatment of cancer. Whether statins may prevent cancer occurrence is a matter of debate and an unanswered question; undoubtedly experimental models have clearly demonstrated the potential of statins as direct cytotoxic agents, which can reduce tumour development or metastasis spread, even more so when combined with cytotoxic drugs. Until now, however, only few data in humans support the idea that statins could rightfully belong to the group of anticancer drugs. Nevertheless, as cancer cell metabolism is being thoroughly revisited, the mevalonate pathway has recently been reported as truly oncogenic, presenting the attractive possibility that mevalonate pathway inhibitors, such as statins, may join the ranks of anticancer drugs.

Clinical outcomes of chemotherapy for diabetic and nondiabetic patients with pancreatic cancer: better prognosis with statin use in diabetic patients

OBJECTIVES

The aim of this study was to clarify the impact of diabetes mellitus (DM) as well as antidiabetic, antihypertensive, and antihyperlipidemic medications such as metformin and statins on survival in patients with advanced pancreatic cancer receiving chemotherapy.

METHODS

We retrospectively reviewed the medical records of 250 patients with advanced pancreatic cancer receiving chemotherapy. Multivariate analyses of prognostic factors for survival were performed both in overall population and in subgroups with and without DM.

RESULTS

Diabetes mellitus was diagnosed in 124 patients (50%) who had less distant metastasis and more hypertension. Thirty patients received statin for hyperlipidemia. Overall survival was 13.3 versus 10.0 months with and without DM (P = 0.084), but hazard ratio of DM was 1.05 (P = 0.758) in the multivariate analysis. Subgroup analysis of diabetic patients, but not in non-diabetic patients, demonstrated use of statins (hazard ratio, 0.40; P = 0.010) as a prognostic factor, as well as distant metastasis, performance status, combination therapy with gemcitabine and S-1, and use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. No antidiabetic medications were prognostic factors.

CONCLUSIONS

Neither DM nor antidiabetic treatment had prognostic impact on advanced pancreatic cancer. Statin use was associated with better survival in the diabetic patients.

Statins and colorectal cancer

The 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors, more commonly referred to as statins, comprise a family of lipid-lowering drugs that are prescribed on a global scale on account of their proven safety and efficacy in reducing mortality from cardiovascular disease. Beyond their potent pharmacologic inhibition of cholesterol biosynthesis, statins appear to have pleiotropic effects, including modulation of cell growth, apoptosis, and inflammation. Through modulation of these pathways, statins have the potential to influence a wide range of disease processes, including cancer. Much attention has focused on the association between statins and colorectal cancer, raising the prospect that these well-tolerated compounds could form the basis of future chemopreventive strategies. Herein, we review the epidemiologic, clinical, and preclinical data relevant to statins and colorectal neoplasia, and discuss the current status and future potential of statins as chemopreventive agents.

Statins and the risk of gastric cancer in diabetes patients

Background

Several studies have suggested a cancer risk reduction in statin users although the evidence remains weak for stomach cancer. The purpose of this study was to use an exact-matching case–control design to examine the risk of gastric cancer associated with the use of statins in a cohort of patients with diabetes.

Methods

Cases were defined as patients with incident gastric cancer identified by International Classification of Diseases 16.0 ~ 16.9 recorded at Samsung Medical Center database during the period of 1999 to 2008, at least 6 months after the entry date of diabetes code. Each gastric cancer case patient was matched with one control patient from the diabetes patient registry in a 1:1 fashion, blinded to patient outcomes.

Results

A total of 983 cases with gastric cancer and 983 controls without gastric cancer, matched by age and sex, were included in the analysis. The presence of prescription for any statin was inversely associated with gastric cancer risk in the unadjusted conditional logistic regression model (OR: 0.18; 95% CI: 0.14 – 0.24; P < .0001). Multivariate analysis using conditional logistic regression with Bonferroni’s correction against aspirin indicated a significant reduction in the risk of gastric cancer in diabetes patients with statin prescriptions (OR: 0.21; 95% CI: 0.16 – 0.28; P < .0001). After adjustment for aspirin use, a longer duration of statin use was associated with reduced risk of gastric cancer, with statistical significance (P<.0001).

Conclusions

A strong inverse association was found between the risk of gastric adenocarcinoma and statin use in diabetic patients.

Statins and cancer: current and future prospects

Statins are inhibitors of 3-hydroxy-methylglutaryl (HMG) CoA reductase. They exhibit effects beyond cholesterol reduction, including anticancer activity. This review presents the effects of statins in vitro and their possible molecular anticancer mechanisms and critically discusses the data regarding the role of statins in cancer prevention. Finally, this review focuses on the use of statins combined with other chemotherapeutics to increase the effectiveness of cancer treatments. Despite rare and inconclusive clinical data, the preclinical results strongly suggest that such combined treatment could be a promising new strategy for the treatment of certain tumor types.

Pharmacological actions of statins: a critical appraisal in the management of cancer

Statins, among the most commonly prescribed drugs worldwide, are cholesterol-lowering agents used to manage and prevent cardiovascular and coronary heart diseases. Recently, a multifaceted action in different physiological and pathological conditions has been also proposed for statins, beyond anti-inflammation and neuroprotection. Statins have been shown to act through cholesterol-dependent and -independent mechanisms and are able to affect several tissue functions and modulate specific signal transduction pathways that could account for statin pleiotropic effects. Typically, statins are prescribed in middle-aged or elderly patients in a therapeutic regimen covering a long life span during which metabolic processes, aging, and concomitant novel diseases, including cancer, could occur. In this context, safety, toxicity, interaction with other drugs, and the state of health have to be taken into account in subjects treated with statins. Some evidence has shown a dichotomous effect of statins with either cancer-inhibiting or -promoting effects. To date, clinical trials failed to demonstrate a reduced cancer occurrence in statin users and no sufficient data are available to define the long-term effects of statin use over a period of 10 years. Moreover, results from clinical trials performed to evaluate the therapeutic efficacy of statins in cancer did not suggest statin use as chemotherapeutic or adjuvant agents. Here, we reviewed the pharmacology of the statins, providing a comprehensive update of the current knowledge of their effects on tissues, biological processes, and pathological conditions, and we dissected the disappointing evidence on the possible future use of statin-based drugs in cancer therapy.

Prognostic significance of monocarboxylate transporter 4 expression in patients with colorectal cancer

Cancer cells generally have a high rate of glycolysis and produce larger quantities of lactate as compared to the surrounding normal cells. Monocarboxylate transporter 4 (MCT4) is one of the proton pumps exchanging the lactate through the plasma membrane. The prognostic significance of MCT4 expression has not been evaluated in patients with colorectal cancer (CRC). Surgical specimens from 105 CRC patients were immunohistochemically stained using a polyclonal anti-MCT4 antibody. The relationships among the MCT4 expression, clinicopathological factors and prognosis were evaluated. A total of 53 (50.5%) of the 105 patients with CRC were determined to have tumors positive for MCT4 expression. The expression of MCT4 significantly correlated with the tumor size, depth of invasion, lymph node metastasis, distant metastasis and TNM staging. The survival rate of the patients who were positive for MCT4 expression was significantly lower than that of patients with negative MCT4 expression. Positive MCT4 expression was a significantly poor prognostic factor, as determined by both univariate and multivariate analyses. Therefore, positive MCT4 expression appears to be a useful marker for tumor progression and prognosis in patients with CRC.