Synergistic effect of simvastatin plus NS398 on inhibition of proliferation and survival in hepatocellular carcinoma cell line

Aspirin in Patients with Viral Hepatitis: Systematic Review and Meta-Analysis of Observational Studies

BACKGROUND

Hepatocellular carcinoma (HCC) is a disease demonstrating increasing morbidity and mortality, especially in patients with chronic viral hepatitis. Studies have shown that aspirin can reduce the incidence of liver cancer; however, the degree of benefit in patients with viral hepatitis is unclear. This study focused on the association between aspirin use and HCC risk in patients with chronic viral hepatitis.

METHODS

A systematic search of the PubMed, Embase, Web of Science, and Cochrane Library databases was performed from the earliest available date to December 16, 2023. The primary outcome was HCC incidence, and the secondary outcome was gastrointestinal bleeding. The results were expressed as hazard ratios (HRs) and 95% confidence intervals (CIs). Meta-analyses were performed by using random or fixed-effects models based on the heterogeneity assessed via the I2 statistic.

RESULTS

A total of 13 articles (303,414 participants and 14,423 HCC patients) were included in the analysis. The incidence of HCC in aspirin users was lower than that in non-aspirin users (HR 0.75; 95% CI, 0.68-0.83; P < 0.001; I2 = 90.0%). Subgroup analysis further showed that this effect may be more obvious in HCV patients, non-cirrhotic patients, patients with statins, and long-term aspirin users, but it may have the risk of gastrointestinal bleeding (HR 1.13; 95% CI, 1.07-1.20; P = 0.906; I2 = 0.0%).

CONCLUSIONS

Our meta-analysis shows that in patients with chronic viral hepatitis, aspirin use is associated with a significantly reduced risk of liver cancer, but attention should be paid to the possible risk of gastrointestinal bleeding, and this conclusion needs further validation in the future.

Don't Judge a Book by Its Cover: The Role of Statins in Liver Cancer

Statins, which are inhibitors of 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase, are an effective pharmacological tool for lowering blood cholesterol levels. This property makes statins one of the most popular drugs used primarily to prevent cardiovascular diseases, where hyperlipidemia is a significant risk factor that increases mortality. Nevertheless, studies conducted mainly in the last decade have shown that statins might prevent and treat liver cancer, one of the leading causes of cancer-related mortality worldwide. This narrative review summarizes the scientific achievements to date regarding the role of statins in liver tumors. Molecular biology tools have revealed that cell growth and proliferation can be inhibited by statins, which further inhibit angiogenesis. Clinical studies, supported by meta-analysis, confirm that statins are highly effective in preventing and treating hepatocellular carcinoma and cholangiocarcinoma. However, this effect may depend on the statin's type and dose, and more clinical trials are required to evaluate clinical effects. Moreover, their potential hepatotoxicity is a significant caveat for using statins in clinical practice. Nevertheless, this group of drugs, initially developed to prevent cardiovascular diseases, is now a key candidate in hepato-oncology patient management. The description of new drug-statin-like structures, e.g., with low toxicity to liver cells, may bring another clinically significant improvement to current cancer therapies.

Improved anti-fibrotic effects by combined treatments of simvastatin and NS-398 in experimental liver fibrosis models

BACKGROUND/AIMS

Efficient anti-fibrotic therapies are required for the treatment of liver cirrhosis. Hydroxymethylglutaryl-coenzyme A reductase inhibitors (statins) and cyclooxygenase-2 (COX-2) inhibitors have been reported to have anti-fibrotic effects. Here, we investigated whether combined treatment with a statin and a COX-2 inhibitor has synergistic anti-fibrotic effects.

METHODS

The effects of treatment strategies incorporating both simvastatin and a COX-2 inhibitor, NS-398, were investigated using an immortalized human hepatic stellate cell line (LX-2) and a hepatic fibrosis mouse model developed using thioacetamide (TAA) in drinking water. Cellular proliferation was investigated via 5-bromo-2-deoxyuridine uptake. Pro- and anti-apoptotic factors were investigated through Western blotting and real-time polymerase chain reaction analysis.

RESULTS

The evaluation of the anti-proliferative effects on LX-2 cells showed that the observed effects were more pronounced with combination therapy than with single-drug therapy. Moreover, hepatic fibrosis and collagen deposition decreased significantly in TAA-treated mice in response to the combined treatment strategy. The mechanisms underlying the anti-fibrotic effects of the combination therapy were investigated. The effects of the combination therapy were correlated with increased expression levels of extracellular signal-regulated kinase 1/2 signaling molecules, upregulation of the Bax/Bcl-2 signaling pathway, inhibition of the transforming growth factor-β signaling pathway, and inhibition of tissue inhibitor of matrix metalloproteinases 1 and 2.

CONCLUSION

The combination of simvastatin and NS-398 resulted in a synergistic anti-fibrotic effect through multiple pathways. These findings offer a theoretical insight into the possible clinical application of this strategy for the treatment of advanced liver diseases with hepatic fibrosis.

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.

Statins as adjuvants in the treatment of ovarian cancer: Controversy and misunderstanding

Ovarian cancer is frequently detected in advanced stages when the chances of survival are very low. Although chemotherapy is the treatment of choice, it is often rapidly compromised by the development of chemoresistance in patients. There are few pharmacological alternatives for managing chemoresistant ovarian cancer and statins have been suggested as an alternative, but their use is considered controversial. We present an overview of the most relevant epidemiological, in vitro and in vivo studies on the effects of statins in mono- or polytherapy for ovarian cancer. We conclude that the negative or inconclusive results of some epidemiological studies on statin-based cancer treatment are probably due, in large part, to the low doses given to patients, equivalent to those prescribed for hypercholesterolemia. Higher concentrations are well tolerated in animal models and by most patients in clinical trials. Future research is necessary to explore this possibility.

Aspirin Use Is Associated with a Reduced Incidence of Hepatocellular Carcinoma: A Systematic Review and Meta-analysis

Hepatocellular carcinoma (HCC) is the third-leading cause of cancer-related death worldwide, with a growing incidence and poor prognosis. While some recent studies suggest an inverse association between aspirin use and reduced HCC incidence, other data are conflicting. To date, the precise magnitude of risk reduction-and whether there are dose-dependent and duration-dependent associations-remains unclear. To provide an updated and comprehensive assessment of the association between aspirin use and incident HCC risk, we conducted a systematic review and meta-analysis of all observational studies published through September 2020. Using random-effects meta-analysis, we calculated the pooled relative risks (RRs) and 95% confidence intervals (CIs) for the association between aspirin use and incident HCC risk. Where data were available, we evaluated HCC risk according to the defined daily dose of aspirin use. Among 2,389,019 participants, and 20,479 cases of incident HCC, aspirin use was associated with significantly lower HCC risk (adjusted RR, 0.61; 95% CI, 0.51-0.73; P ≤ 0.001; I2 = 90.4%). In subgroup analyses, the magnitude of benefit associated with aspirin was significantly stronger in studies that adjusted for concurrent statin and/or metformin use (RR, 0.45; 95% CI, 0.28-0.64) versus those that did not (P heterogeneity = 0.02), studies that accounted for cirrhosis (RR, 0.49; 95% CI, 0.45-0.52) versus those that did not (P heterogeneity = 0.02), and studies that confirmed HCC through imaging/biopsy (RR, 0.30; 95% CI, 0.15-0.58) compared with billing codes (P heterogeneity < 0.001). In four studies, each defined daily dose was associated with significantly lower HCC risk (RR, 0.98; 95% CI, 0.97-0.98), corresponding to an 8.4% risk reduction per year of aspirin use. Conclusion: In this comprehensive systematic review and meta-analysis, aspirin use was associated with a significant reduction in HCC risk. These benefits appeared to increase with increasing dose and duration of aspirin use.

The Innovative Potential of Statins in Cancer: New Targets for New Therapies

Numerous and different types of cancers possess the dysregulation of the mevalonate pathway as a common feature. Statins, traditionally applied in cardiovascular diseases to reduce lipid levels, subsequently have been discovered to exhibit anti-cancer activities also. Indeed, statins influence proliferation, migration, and survival of cancer cells by regulating crucial signaling proteins, such as Rho, Ras, and Rac. Recently, several studies have demonstrated that simvastatin, fluvastatin, and lovastatin are implicated in different pathways that enhance the survival time of patients with cancer under treatment in combination with antineoplastic agents. In this minireview, we present an overview of the most important studies conducted regarding the use of statins in cancer therapy up to date.

Simvastatin re-sensitizes hepatocellular carcinoma cells to sorafenib by inhibiting HIF-1α/PPAR-γ/PKM2-mediated glycolysis

BACKGROUND

Hepatocellular carcinoma (HCC) is a common primary malignant tumor which usually progresses to an advanced stage because of late diagnosis. Sorafenib (Sora) is a first line medicine for advanced stage HCC; however, it has been faced with enormous resistance. Simvastatin (Sim) is a cholesterol-lowering drug and has been reported to inhibit tumor growth. The present study aims to determine whether Sora and Sim co-treatment can improve Sora resistance in HCC.

METHODS

The HCC cell line LM3 and an established Sora-resistant LM3 cell line (LM3-SR) were used to study the relationship between Sora resistance and aerobic glycolysis. Cell proliferation, apoptosis and glycolysis levels were analyzed by western blotting, flow cytometry analysis and biomedical tests. A xenograft model was also used to examine the effect of Sim in vivo. Detailed mechanistic studies were also undertaken by the use of activators and inhibitors, and lentivirus transfections.

RESULTS

Our results demonstrated that the resistance to Sora was associated with enhanced aerobic glycolysis levels. Furthermore, LM3-SR cells were more sensitive to Sim than LM3 cells, suggesting that combined treatment with both Sora and Sim could enhance the sensitivity of LM3-SR cells to Sora. This finding may be due to the suppression of the HIF-1α/PPAR-γ/PKM2 axis.

CONCLUSIONS

Simvastatin can inhibit the HIF-1α/PPAR-γ/PKM2 axis, by suppressing PKM2-mediated glycolysis, resulting in decreased proliferation and increased apoptosis in HCC cells, and re-sensitizing HCC cells to Sora.

Risk factors and prevention of hepatocellular carcinoma in the era of precision medicine

Patients who develop chronic fibrotic liver disease, caused by viral or metabolic aetiologies, are at a high risk of developing hepatocellular carcinoma (HCC). Even after complete HCC tumour resection or ablation, the carcinogenic tissue microenvironment in the remnant liver can give rise to recurrent de novo HCC tumours, which progress into incurable, advanced-stage disease in most patients. Thus, early detection and prevention of HCC development is, in principle, the most impactful strategy to improve patient prognosis. However, a "one-size-fits-all" approach to HCC screening for early tumour detection, as recommended by clinical practice guidelines, is utilised in less than 20% of the target population, and the performance of screening modalities, including ultrasound and alpha-fetoprotein, is suboptimal. Furthermore, optimal screening strategies for emerging at-risk patient populations, such as those with chronic hepatitis C after viral cure, or those with non-cirrhotic, non-alcoholic fatty liver disease remain controversial. New HCC biomarkers and imaging modalities may improve the sensitivity and specificity of HCC detection. Clinical and molecular HCC risk scores will enable precise HCC risk prediction followed by tailoured HCC screening of individual patients, maximising cost-effectiveness and optimising allocation of limited medical resources. Several aetiology-specific and generic HCC chemoprevention strategies are evolving. Epidemiological and experimental studies have identified candidate chemoprevention targets and therapies, including statins, anti-diabetic drugs, and selective molecular targeted agents, although their clinical testing has been limited by the lengthy process of cancer development that requires long-term, costly studies. Individual HCC risk prediction is expected to overcome the challenge by enabling personalised chemoprevention, targeting high-risk patients for precision HCC prevention and substantially improving the dismal prognosis of HCC.

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.

Protein-protein interactions among signaling pathways may become new therapeutic targets in liver cancer (Review)

Numerous signaling pathways have been shown to be dysregulated in liver cancer. In addition, some protein-protein interactions are prerequisite for the uncontrolled activation or inhibition of these signaling pathways. For instance, in the PI3K/AKT signaling pathway, protein AKT binds with a number of proteins such as mTOR, FOXO1 and MDM2 to play an oncogenic role in liver cancer. The aim of the present review was to focus on a series of important protein-protein interactions that can serve as potential therapeutic targets in liver cancer among certain important pro-carcinogenic signaling pathways. The strategies of how to investigate and analyze the protein-protein interactions are also included in this review. A survey of these protein interactions may provide alternative therapeutic targets in liver cancer.

Simvastatin induces NFκB/p65 down-regulation and JNK1/c-Jun/ATF-2 activation, leading to matrix metalloproteinase-9 (MMP-9) but not MMP-2 down-regulation in human leukemia cells

The aim of the present study was to explore the signaling pathways associated with the effect of simvastatin on matrix metalloproteinase-2 (MMP-2)/MMP-9 expression in human leukemia K562 cells. In sharp contrast to its insignificant effect on MMP-2, simvastatin down-regulated MMP-9 protein expression and mRNA levels in K562 cells. Simvastatin-induced Pin1 down-regulation evoked NFκB/p65 degradation. Meanwhile, simvastatin induced JNK-mediated c-Jun and ATF-2 activation. Over-expression of Pin1 suppressed simvastatin-induced MMP-9 down-regulation. Treatment with SP600125 (a JNK inhibitor) or knock-down of JNK1 reduced MMP-2 expression in simvastatin-treated cells. Simvastatin enhanced the binding of c-Jun/ATF-2 with the MMP-2 promoter. Down-regulation of c-Jun or ATF-2 by siRNA revealed that c-Jun/ATF-2 activation was crucial for MMP-2 expression. Suppression of p65 activation or knock-down of Pin1 by shRNA reduced MMP-2 and MMP-9 expression in K562 cells. Over-expression of constitutively active JNK1 rescued MMP-2 expression in Pin1 shRNA-transfected cells. Simvastatin treatment also suppressed MMP-9 but not MMP-2 expression in human leukemia U937 and KU812 cells. Taken together, our data indicate that simvastatin-induced p65 instability leads to MMP-9 down-regulation in leukemia cells, while simvastatin-induced JNK1/c-Jun/ATF-2 activation maintains the MMP-2 expression underlying p65 down-regulation.