Simvastatin inhibits tumor angiogenesis in HER2-overexpressing human colorectal cancer

Investigating the therapeutic promise of drug-repurposed-loaded nanocarriers: A pioneering strategy in advancing colorectal cancer treatment

Globally, colorectal cancer is a major health problem that ranks in third place in terms of occurrence and second in terms of mortality worldwide. New cases increase annually, with the absence of effective therapies, especially for metastatic colorectal cancer, emphasizing the need for novel therapeutic approaches. Although conventional treatments are commonly used in oncotherapy, their success rate is low, which leads to the exploration of novel technologies. Recent efforts have focused on developing safe and efficient cancer nanocarriers. With their nanoscale properties, nanocarriers have the potential to utilize internal metabolic modifications amid cancer and healthy cells. Drug repurposing is an emerging strategy in cancer management as it is a faster, cheaper, and safer method than conventional drug development. However, most repurposed drugs are characterized by low-key pharmacokinetic characteristics, such as poor aqueous solubility, permeability, retention, and bioavailability. Nanoparticles formulations and delivery have expanded over the past few decades, creating opportunities for drug repurposing and promises as an advanced cancer modality. This review provides a concise and updated overview of colorectal cancer treatment regimens and their therapeutic limitations. Furthermore, the chemotherapeutic effect of various FDA-approved medications, including statins, non-steroidal anti-inflammatory drugs, antidiabetic and anthelmintic agents, and their significance in colorectal cancer management. Along with the role of various nanocarrier systems in achieving the desired therapeutic outcomes of employing these redefined drugs.

The mevalonate pathway contributes to breast primary tumorigenesis and lung metastasis

The mevalonate pathway plays an important role in breast cancer and other tumor types. However, many issues remain obscure as yet regarding its mechanism of regulation and action. In the present study, we report that the expression of mevalonate pathway enzymes is mediated by the RHO guanosine nucleotide exchange factors VAV2 and VAV3 in a RAC1- and sterol regulatory element-binding factor (SREBF)-dependent manner in breast cancer cells. Furthermore, in vivo tumorigenesis experiments indicated that the two most upstream steps of this metabolic pathway [3-hydroxy-3-methylglutaryl-coenzyme A synthase 1 (HMGCS1) and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR)] are important for primary tumorigenesis, angiogenesis, and cell survival in breast cancer cells. HMGCR, but not HMGCS1, is also important for the extravasation and subsequent fitness of breast cancer cells in the lung parenchyma. Genome-wide expression analyses revealed that HMGCR influences the expression of gene signatures linked to proliferation, metabolism, and immune responses. The HMGCR-regulated gene signature predicts long-term tumor recurrence but not metastasis in cohorts of nonsegregated and chemotherapy-resistant breast cancer patients. These results reveal a hitherto unknown, VAV-catalysis-dependent mechanism involved in the regulation of the mevalonate pathway in breast cancer cells. They also identify specific mevalonate-pathway-dependent processes that contribute to the malignant features of breast cancer cells.

Simvastatin induces pyroptosis via ROS/caspase-1/GSDMD pathway in colon cancer

BACKGROUND

The outcome of patients with colon cancer is still unsatisfied nowadays. Simvastatin is a type of statins with anti-cancer activity, but its effect on colon cancer cells remains unclear. The present study is intended to determine the underlying mechanism of simvastatin in treatment of colon cancer.

METHODS

The viability and pyroptosis rate of cells treated and untreated with simvastatin were analysed by CCK-8 and flow cytometry assays, respectively. We used DCFH-DA and flow cytometry to detect reactive oxygen species (ROS) production. Levels of pyroptosis markers were detected by western blotting analysis or immunofluorescence staining. Besides, the anticancer properties of simvastatin on colon cancer were further demonstrated using a cell line based xenograft tumor model.

RESULTS

Simvastatin treatment in HCT116 and SW620 induced pyroptosis and suppressed cell proliferation, with changes in the expression level of NLPR3, ASC, cleaved-caspase-1, mature IL-1β, IL-18 and GSDMD-N. Moreover, inhibition of caspase-1 and ROS attenuated the effects of simvastatin on cancer cell viability. In addition, it was identified that simvastatin has an anti-tumor effect by down-regulating ROS production and inducing downstream caspase-1 dependent pyroptosis in the subcutaneous transplantation tumors of HCT116 cells in BALB/c nude mice.

CONCLUSIONS

Our in vitro and in vivo results indicated that simvastatin induced pyroptosis through ROS/caspase-1/GSDMD pathway, thereby serving as a potential agent for colon cancer treatment. Video Abstract.

Repurposed Drugs in Gastric Cancer

Gastric cancer (GC) is one of the major causes of death worldwide, ranking as the fifth most incident cancer in 2020 and the fourth leading cause of cancer mortality. The majority of GC patients are in an advanced stage at the time of diagnosis, presenting a poor prognosis and outcome. Current GC treatment approaches involve endoscopic detection, gastrectomy and chemotherapy or chemoradiotherapy in an adjuvant or neoadjuvant setting. Drug development approaches demand extreme effort to identify molecular mechanisms of action of new drug candidates. Drug repurposing is based on the research of new therapeutic indications of drugs approved for other pathologies. In this review, we explore GC and the different drugs repurposed for this disease.

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.

HER2 overexpression is a putative diagnostic and prognostic biomarker for late-stage colorectal cancer in North African patients

Aim: Colorectal cancer (CRC) is one of the leading cancers in the world. Even though its mortality and pathophysiology are well documented in the US and the European countries, it is seldom studied in North African population. Recent studies have shown link of HER2 overexpression in oesophageal and gastric cancers. The aim of this study is to assess the HER2 protein and mRNA expression and its correlation with tumor pathogenesis in Libyan CRC patients.

Methodology: A total of 17 FFPE tissue blocks were collected from patients with primary CRC. The HER2 protein expression was assessed by immunohistochemistry and the mRNA expression was assessed using qRT-PCR. Survival analysis of the role of HER2 overexpression on rectal adenocarcinoma was carried out on additional 165 patients.

Results: From the CRC cohort, adenocarcinoma was found to be more frequent accounting for 88.2%, and 11.8% for mucinous adenocarcinomas. Almost 47% of the cases were positive for HER2 (score ≥ 2+) and about 50% adenocarcinoma cases with tumor grade II were positive for HER2. Moreover, 57.4% adenocarcinoma patients with grade-II tumor had undergone right hemicolectomy. Furthermore, significant correlation (p = 0.03) between the HER2 mRNA expression with the tumor grade was observed. In addition, poor overall all survival was observed with high HER2 expression in rectum adenocarcinoma.

Conclusion: To our knowledge, this is the first study that HER2 overexpression correlates with more aggressive colorectal cancer in North African population. Our study shows that HER2 overexpression associates with right colon surgeries. Also, the correlation of mRNA and protein expression could warrant the implementation of a nationwide screening program for HER2 positivity in CRC patients. Taken together, stratifying patients according to HER2 expression can help in the diagnosis and prognosis of CRC patients from North African origin.

Heterogeneous clinical and pathological landscapes of HER2 positive colorectal cancer

Introduction: Metastatic (m) colorectal cancer (CRC) can be divided into specific subgroups under the 'one gene, one drug' paradigm of precision medicine. Progress of targeted therapy in mCRC patients significantly improved the overall survival rate, notably by therapy targeting of EGFR signaling in RAS wild-type mCRC patients. Activation of the HER2 pathway is an important mechanism of resistance for anti-EGFR therapy.Area covered: Inhibition of HER2 with monoclonal antibodies and/or tyrosine kinase inhibitors induces tumor responses in partial HER2-positive CRC refractory to standard systemic therapy. This manuscript aimed to provide an overall insight of the HER2 expression pattern and highlighted specific clinicopathological and molecular features involved in mCRC. In addition, we summarize preclinical and clinical trials in HER2-positive mCRC.Expert opinion: The status and progression of HER2-positive gastric cancer and breast cancer and anti-HER2 therapy have been reported widely. However, the understanding of HER2-positive CRC models which may guide future therapeutic decision-making is poor. Therefore, it is essential to summarize the existing research to extract similarity and difference among various studies.

The potential use of simvastatin for cancer treatment: A review

Statins, typically used to reduce lipid levels, have been rediscovered for exhibiting anticancer activities. Among them, especially simvastatin may influence the proliferation, migration, and survival of cancer cells. The concept of using statins to treat cancer has been adopted since the 1990s In vitro and in vivo experiments and cohort studies using statins have been carried out to demonstrate their antitumor effects (such as proliferation and migration impairment) by influencing inflammatory and oxidative stress-related tumorigenesis. Nevertheless, the biological mechanisms for these actions are not fully elucidated. In this review, we present an overview of the most important studies conducted from 2015 to date on the use of simvastatin in cancer therapy. This review brings the most recent perspectives and targets in epidemiological, in vitro, and in vivo studies, regarding the use of simvastatin alone or in combination with other drugs for the treatment of various types of cancer.

Clinical Efficacy and Safety of Angiogenesis Inhibitors: Sex Differences and Current Challenges

Vasoactive molecules, such as vascular endothelial growth factor (VEGF) and endothelins, share cytokine-like activities and regulate endothelial cell (EC) growth, migration and inflammation. Some endothelial mediators and their receptors are targets for currently approved angiogenesis inhibitors, drugs that are either monoclonal antibodies raised towards VEGF, or inhibitors of vascular receptor protein kinases and signaling pathways. Pharmacological interference with the protective functions of ECs results in a similar spectrum of adverse effects. Clinically, the most common side effects of VEGF signaling pathway inhibition include an increase in arterial pressure, left ventricular (LV) dysfunction ultimately causing heart failure, and thromboembolic events, including pulmonary embolism, stroke, and myocardial infarction. Sex steroids such as androgens, progestins, and estrogen and their receptors (ERα, ERβ, GPER; PR-A, PR-B; AR) have been identified as important modifiers of angiogenesis, and sex differences have been reported for anti-angiogenic drugs. This review article discusses the current challenges clinicians are facing with regard to angiogenesis inhibitor treatments, including the need to consider sex differences affecting clinical efficacy and safety. We also propose areas for future research taking into account the role of sex hormone receptors and sex chromosomes. Development of new sex-specific drugs with improved target and cell-type selectivity likely will open the way personalized medicine in men and women requiring antiangiogenic therapy and result in reduced adverse effects and improved therapeutic efficacy.

Ras Signaling in Breast Cancer

Ras proteins mediate extracellular and cytoplasmic signaling networks via receptor tyrosine kinase. The Ras pathway induces activation of signaling molecules involved in cell proliferation and growth, cell survival and apoptosis, metabolism, and motility. Although Ras mutations in breast cancer are not frequently reported, hyperactivation of Ras signaling plays an important role in breast cancer growth and progression. Oncogenic Ras activation occurs via loss of Ras GTPase-activating proteins, overexpression of growth factor receptor, and stimulation by various cytokines. Effective control of oncogenic Ras is one of the therapeutic strategies in breast cancer. The mechanisms of intracellular localization, activation, and signaling pathway of Ras in cancer have been used to develop therapeutic candidates. Recent studies have reported an effective therapy for breast cancer by inhibition of enzymes involved in the posttranslational modification of Ras, such as farnesyltransferase and geranylgeranyltransferase 1, and anti-cancer therapies targeting the epidermal growth factor receptor (EGFR). Emerging targets involved in EGF-mediated Ras activity in breast cancer have shed new insight into Ras activation in breast cancer progression. These alternative mechanisms for Ras signaling pathway may suggest novel therapeutic approaches for targeting Ras in breast cancer. In spite of the difficulties in targeting Ras protein, important discoveries highlight the direct inhibition of Ras activity. Further studies may elucidate the effects of targeting Ras protein and the clinical relevance thereof.

A novel piperine analogue exerts in vivo antitumor effect by inducing oxidative, antiangiogenic and immunomodulatory actions

Structural diversity characterizes natural products as prototypes for design of lead compounds. The aim of this study was to synthetize, and to evaluate the toxicity and antitumor action of a new piperine analogue, the butyl 4-(4-nitrobenzoate)-piperinoate (DE-07). Toxicity was evaluated against zebrafish, and in mice (acute and micronucleus assays). To evaluate the DE-07 antitumor activity Ehrlich ascites carcinoma model was used in mice. Angiogenesis, Reactive Oxygen Species (ROS) production and cytokines levels were investigated. Ninety-six hours exposure to DE-07 did not cause morphological or developmental changes in zebrafish embryos and larvae, with estimated LC₅₀ (lethal concentration 50%) higher than 100 μg/mL. On the acute toxicity assay in mice, LD₅₀ (lethal dose 50%) was estimated at around 1000 mg/kg, intraperitoneally (i.p.). DE-07 (300 mg/kg, i.p.) did not induce increase in the number of micronucleated erythrocytes in mice, suggesting no genotoxicity. On Ehrlich tumor model, DE-07 (12.5, 25 or 50 mg/kg, i.p.) induced a significant decrease on cell viability. In addition, there was an increase on ROS production and a decrease in peritumoral microvessels density. Moreover, DE-07 induced an increase of cytokines levels involved in oxidative stress and antiangiogenic effect (IL-1β, TNF-α and IL-4). No significant clinical toxicological effects were recorded in Ehrlich tumor transplanted animals. These data provide evidence that DE-07 presents low toxicity, and antitumor effect via oxidative and antiangiogenic actions by inducing modulation of inflammatory response in the tumor microenvironment.

Picroside II, an iridoid glycoside from Picrorhiza kurroa, suppresses tumor migration, invasion, and angiogenesis in vitro and in vivo

Cancer is one of the leading causes of death worldwide. The development of novel anti-cancer agents from natural products is a promising approach to reduce cancer mortality. In this study, we investigated the anti-metastatic and anti-angiogenic activities of picroside II (PII) in human breast cancer cells both in vitro and in vivo. Our results demonstrated that PII significantly inhibited the migration and invasion of MDA-MB-231 cancer cells. With the treatment of PII, the activity of matrix metalloproteinase 9 (MMP-9) in MDA-MB-231 cancer cells was significantly inhibited both in vitro and in vivo. Meanwhile, PII showed effective anti-metastatic activity in an experimental lung metastasis model. Interestingly, cluster of differentiation 31 (CD31), a marker of angiogenesis, was significantly downregulated in the PII-treated tumor samples, indicating the anti-angiogenic activity of PII. Furthermore, we demonstrated that PII significantly inhibited the migration, invasion, and tube formation of human umbilical vein endothelial cells (HUVECs). The inhibition of MMP-9 activity in PII-treated HUVECs was also demonstrated. Finally, the suppression of angiogenesis by PII in the chick embryo chorioallantoic membrane (CAM) was observed. In conclusion, our results demonstrated that PII effectively inhibited the metastasis and angiogenesis of cancer cells both in vitro and in vivo, and thus, might be a novel candidate for cancer therapy.

Kruppel-like factor 2 mediated anti-proliferative and anti-metastasis effects of simvastatin in p53 mutant colon cancer

The changes in cellular metabolism play an important role in promoting tumor progression. Recent findings suggested that the mutation of tumor suppressor gene p53 promoted lipids synthesis and mutant p53 (mutp53) was essential for regulating mevalonate pathway for cholesterol synthesis. Simvastatin, a 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitor, was found to exhibit therapeutic effects against many types of cancers including breast cancer, colon cancer, lung cancer, etc. However, the underlying mechanism of the antitumor effect of simvastatin still needs to be further investigated. Our data demonstrated that suppression of mevalonate pathway by simvastatin significantly upregulated Kruppel-like factor 2 (KLF2) and p21^WAF1/CIP1 expression in mutp53 colon cancer cells SW1116 but not in p53 wild type cells HCT116. Meanwhile, we found that overexpression of KLF2 could significantly induce p21^WAF1/CIP1 expression, inhibit Wnt signaling and suppress epithelial-mesenchymal transition, indicating that KL2 might mediate antitumor effect of simvastatin in SW1116 cells. Moreover, bioinformatic analysis from The Cancer Genome Atlas (TCGA) database indicated that KLF2 were positively correlated with CDKN1A (encoding p21^WAF1/CIP1), both of which were downregulated in colon cancer tissue, especially in p53 mutant colon cancer tissue. The results showed that KLF2 might be a tumor suppressor gene in colon cancer, which was in accordance with our experimental data. We also found that CDKN1A expression in mutant p53 colon cancer tissue was significant decreased when compared with p53 wild type colon cancer tissue, while Wnt ligand Wnt5a exhibited the highest level in p53 mutant colon cancer tissue. These data provide strong evidences for clinical application of simvastatin in treatment of colon cancer with p53 mutation.

Second primary malignancy in patients with cholangiocarcinoma: a population-based study

Background

A population-based estimate of risk of second primary malignancy (SPM) in patients with cholangiocarcinoma (CCA) is still lacking.

Objectives

To investigate the overall and site-specific risk of SPM in patients with CCA. To identify risk factors of SPM and further evaluate the impact of SPM on overall survival (OS) and disease specific survival (DSS) in patients with CCA.

Methods

Patients with histologically diagnosed CCA between 1973 and 2015 were identified from the Surveillance, Epidemiology and End Results database. Standardized incidence ratio (SIR) was calculated. Risk factors for SPM and CCA survival were evaluated by logistic, Cox, and nomogram methods.

Results

We found that the overall risk of SPM in patients with CCA was significantly higher than that in the general population (SIR =1.27, 95% CI =1.03–1.55, P<0.05). The risk of SPM was significantly increased at specific sites, including transverse colon, intrahepatic bile duct, other biliary, and thyroid. A significant increase in overall risk was characterized in the subgroups of patients aged ≤29, patients aged 30–59 years, females, whites, and patients with latency ≤11 months (63.41, 2.45, 1.4, 1.3, and 2.6-fold, respectively). In patients with CCA, not having undergone surgery for the first primary malignancy (vs having undergone surgery for the first primary malignancy; HR =0.269; 95% CI =0.211–0.342; P<0.001) was associated with significantly decreased risk of SPM. Patients with SPM had better OS and DSS than those without SPM (Log rank P<0.001). Absence of SPM was an independent risk factor for poorer OS and DSS.

Conclusion

Although the risk of SPM in patients with CCA was significantly increased, the presence of SPM did not shorten OS and DSS of patients with CCA, possibly due to the relatively poorer survival of patients with CCA.

Effects of statin exposure and lung cancer survival: A meta-analysis of observational studies

Statin exposure has been reported to improve survival in several cancers. However, studies evaluating the association between statins and prognostic outcomes in patients with lung cancer are conflicting and heterogeneous. Pubmed, EMBASE and reference lists of included studies were searched to identify studies investigating the association between statin exposure and lung cancer prognosis. The primary outcome measure was overall survival (OS) and secondary ones included cancer-specific survival (CSS) and recurrence-free survival (RFS). Hazard ratios (HRs) with 95% confidence intervals (95% CIs) of these outcomes were pooled using random-effects models. Thirteen studies with data from 99,297 individuals satisfying the inclusion criteria were identified. Studies were ranked to be at low to moderate risk of bias. Meta-analysis showed that statin exposure was significantly associated with improved OS (pooled HR 0.79, 95% CI 0.72-0.86), CSS (pooled HR 0.83, 95% CI 0.77-0.89) and RFS (pooled HR 0.85, 95% CI 0.81-0.89). Subgroup analyses showed that statin users after diagnosis of lung cancer had more survival benefit for OS (HR 0.68, 95% CI 0.51-0.92) than those before diagnosis (HR 0.86, 95% CI 0.81-0.90) and current users (HR 0.79, 95% CI 0.62-1.02) (P for interaction <0.001). Besides, statin users were likely to have more survival benefits in stage IV lung cancer patients (HR 0.77, 95% CI 0.74-0.79) than in mixed stage (I-IV or I-III) patients (P for interaction = 0.004). Statin exposure is associated with significantly improved survival in patients with lung cancer. Future studies are warranted to further demonstrate the therapeutic role of statins in specific lung cancer patients.

Anti-Angiogenic Alternative and Complementary Medicines for the Treatment of Endometriosis: A Review of Potential Molecular Mechanisms

Endometriosis is caused by the growth or infiltration of endometrial tissues outside of the endometrium and myometrium. Symptoms include pain and infertility. Surgery and hormonal therapy are widely used in Western medicine for the treatment of endometriosis; however, the side effects associated with this practice include disease recurrence and menopause, which can severely influence quality of life. Angiogenesis is the main biological mechanism underlying the development of endometriosis. Numerous natural products and Chinese medicines with potent anti-angiogenic effects have been investigated, and the molecular basis underlying their therapeutic effects in endometriosis has been explored. This review aims to describe natural products and compounds that suppress angiogenesis associated with endometriosis and to assess their diverse molecular mechanisms of action. Furthermore, this review provides a source of information relating to alternative and complementary therapeutic products that mediate anti-angiogenesis. An extensive review of the literature and electronic databases, such as the China National Knowledge Infrastructure, PubMed, and Embase, was conducted using the keywords 'endometriosis,' 'traditional Chinese medicine,' 'Chinese herbal medicine,' 'natural compounds,' and 'anti-angiogenic' therapy. Anti-angiogenic therapy is an emerging strategy for the treatment of endometriosis. Natural anti-angiogenic products and Chinese medicines provide several beneficial clinical effects, including pain relief. In this review, we summarize clinical trials and experimental studies of endometriosis using natural products and Chinese medicines. In particular, we focus on anti-angiogenic products and alternative and complementary medicines for the treatment of endometriosis and additionally examine their therapeutic efficacy and mechanisms of action. Anti-angiogenic natural products and/or compounds provide a new approach for the treatment of endometriosis. Future work will require randomized trials with larger numbers of subjects, as well as long-term follow-up to confirm the findings described here.

Combination therapy of simvastatin and 5, 6-dimethylxanthenone-4-acetic acid synergistically suppresses the aggressiveness of B16.F10 melanoma cells

The major drawback of current anti-angiogenic therapies is drug resistance, mainly caused by overexpression of the transcription factor, hypoxia-inducible factor 1α (HIF-1α) as a result of treatment-induced hypoxia, which stimulates cancer cells to develop aggressive and immunosuppressive phenotypes. Moreover, the cancer cell resistance to anti-angiogenic therapies is deeply mediated by the communication between tumor cells and tumor-associated macrophages (TAMs)-the most important microenvironmental cells for the coordination of all supportive processes in tumor development. Thus, simultaneous targeting of TAMs and cancer cells could improve the outcome of the anti-angiogenic therapies. Since our previous studies proved that simvastatin (SIM) exerts strong antiproliferative actions on B16.F10 murine melanoma cells via reduction of TAMs-mediated oxidative stress and inhibition of intratumor production of HIF-1α, we investigated whether the antitumor efficacy of the anti-angiogenic agent-5,6-dimethylxanthenone-4-acetic acid (DMXAA) could be improved by its co-administration with the lipophilic statin. Our results provide confirmatory evidence for the ability of the combined treatment to suppress the aggressive phenotype of the B16.F10 melanoma cells co-cultured with TAMs under hypoxia-mimicking conditions in vitro. Thus, proliferation and migration capacity of the melanoma cells were strongly decelerated after the co-administration of SIM and DMXAA. Moreover, our data suggested that the anti-oxidant action of the combined treatment, as a result of melanogenesis stimulation, might be the principal cause for the simultaneous suppression of key molecules involved in melanoma cell aggressiveness, present in melanoma cells (HIF-1α) as well as in TAMs (arginase-1). Finally, the concomitant suppression of these proteins might have contributed to a very strong inhibition of the angiogenic capacity of the cell co-culture microenvironment.

Activation of AMPK by simvastatin inhibited breast tumor angiogenesis via impeding HIF-1α-induced pro-angiogenic factor

Substantial data from preclinical studies have revealed the biphasic effects of statins on cardiovascular angiogenesis. Although some have reported the anti‐angiogenic potential of statins in malignant tumors, the underlying mechanism remains poorly understood. The aim of this study is to elucidate the mechanism by which simvastatin, a member of the statin family, inhibits tumor angiogenesis. Simvastatin significantly suppressed tumor cell‐conditioned medium‐induced angiogenic promotion in vitro, and resulted in dose‐dependent anti‐angiogenesis in vivo. Further genetic silencing of hypoxia‐inducible factor‐1α (HIF‐1α) reduced vascular endothelial growth factor and fibroblast growth factor‐2 expressions in 4T1 cells and correspondingly ameliorated HUVEC proliferation facilitated by tumor cell‐conditioned medium. Additionally, simvastatin induced angiogenic inhibition through a mechanism of post‐transcriptional downregulation of HIF‐1α by increasing the phosphorylation level of AMP kinase. These results were further validated by the fact that 5‐aminoimidazole‐4‐carboxamide ribonucleotide reduced HIF‐1α protein levels and ameliorated the angiogenic ability of endothelial cells in vitro and in vivo. Critically, inhibition of AMPK phosphorylation by compound C almost completely abrogated simvastatin‐induced anti‐angiogenesis, which was accompanied by the reduction of protein levels of HIF‐1α and its downstream pro‐angiogenic factors. These findings reveal the mechanism by which simvastatin induces tumor anti‐angiogenesis, and therefore identifies the target that explains the beneficial effects of statins on malignant tumors.

Synergistic effect of receptor-interacting protein 140 and simvastatin on the inhibition of proliferation and survival of hepatocellular carcinoma cells

Hepatocellular carcinoma is the sixth most prevalent malignant tumor and the third most common cause of cancer-associated mortality. Statins have been investigated for carcinoma prevention and treatment. In addition, receptor-interacting protein 140 (RIP140) has been observed to inhibit the Wnt/β-catenin signaling pathway and cell growth. The present study aimed to investigate whether simvastatin (SV) is able to induce SMCC-7721 cell apoptosis through the Wnt/β-catenin signaling pathway. Initially, a cell model of RIP140 overexpression was established, and then cells were treated with SV. The cell growth, viability and apoptosis were measured by cell counting kit-8 and flow cytometry. Furthermore, the expression levels of RIP140, β-catenin, c-myc and cyclin D1 were detected by reverse transcription-quantitative polymerase chain, western blot analysis and immunofluorescence. The results demonstrated that SV significantly increased the expression of RIP140 in SMCC-7721 cells; however, β-catenin, c-myc and cyclin D1 levels were significantly decreased. Furthermore, the immunofluorescence assay of β-catenin confirmed that SV decreased the content of this protein in SMCC-7721 cells. Notably, RIP140 exerted a synergistic effect on the apoptosis rate induced by SV (RIP140 + SV group), while the alteration in RIP140, β-catenin, c-myc and cyclin D1 levels was more evident in the combination group as compared with the RIP140 or SV alone groups. In conclusion, these results suggested that SV is able to induce the apoptosis of SMCC-7721 cells through the Wnt/β-catenin signaling pathway, as well as that RIP140 and SV exert a synergistic effect on the inhibition of cell proliferation and survival.

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.