Blocking the Raf/MEK/ERK pathway sensitizes acute myelogenous leukemia cells to lovastatin-induced apoptosis

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.

Statin use and its association with decreased risk of esophageal squamous cell carcinoma in betel nut chewers

BACKGROUND

Betel nut chewing involves the chewing of areca nuts or betel quid (areca nuts wrapped in betel leaves), which is associated with an increased risk of esophageal squamous cell carcinoma (ESCC). Statins have anticancer properties. We investigated the association between statin use and ESCC risk in betel nut chewers.

METHODS

The study included 105 387 betel nut chewers matched statin users and nonusers. Statin use was defined as the use of ≥28 cumulative defined daily doses (cDDDs) of statin. The primary outcome was incidence of ESCC.

RESULTS

The incidence rate of ESCC was significantly lower in statin users than in nonusers (2.03 vs. 3.02 per 100 000 person-years). Statin users had a lower incidence rate ratio of 0.66 for ESCC (95% confidence interval [CI]: 0.43-0.85) relative to nonusers. After potential confounders were adjusted for, statin use was determined to be associated with a reduced risk of ESCC (adjusted hazard ratio [aHR], 0.68; 95% CI: 0.51-0.91). A dose-response relationship was observed between statin use and ESCC risk; the aHRs for statin use at 28-182 cDDDs, 183-488 cDDDs, 489-1043 cDDDs, and > 1043 cDDDs were 0.92, 0.89, 0.66, and 0.64, respectively.

CONCLUSION

Statin use was revealed to be associated with a reduced risk of ESCC in betel nut chewers.

New insights into the therapeutic potentials of statins in cancer

The widespread clinical use of statins has contributed to significant reductions of cardiovascular morbidity and mortality. Increasing preclinical and epidemiological evidences have revealed that dyslipidemia is an important risk factor for carcinogenesis, invasion and metastasis, and that statins as powerful inhibitor of HMG-CoA reductase can exert prevention and intervention effects on cancers, and promote sensitivity to anti-cancer drugs. The anti-cancer mechanisms of statins include not only inhibition of cholesterol biosynthesis, but also their pleiotropic effects in modulating angiogenesis, apoptosis, autophagy, tumor metastasis, and tumor microenvironment. Moreover, recent clinical studies have provided growing insights into the therapeutic potentials of statins and the feasibility of combining statins with other anti-cancer agents. Here, we provide an updated review on the application potential of statins in cancer prevention and treatment and summarize the underneath mechanisms, with focuses on data from clinical studies.

Statins markedly potentiate aminopeptidase inhibitor activity against (drug-resistant) human acute myeloid leukemia cells

Aim: This study aimed to decipher the molecular mechanism underlying the synergistic effect of inhibitors of the mevalonate-cholesterol pathway (i.e., statins) and aminopeptidase inhibitors (APis) on APi-sensitive and -resistant acute myeloid leukemia (AML) cells. Methods: U937 cells and their sublines with low and high levels of acquired resistance to (6S)-[(R)-2-((S)-Hydroxy-hydroxycarbamoyl-methoxy-methyl)-4-methyl-pentanoylamino]-3,3 dimethyl-butyric acid cyclopentyl ester (CHR2863), an APi prodrug, served as main AML cell line models. Drug combination effects were assessed with CHR2863 and in vitro non-toxic concentrations of various statins upon cell growth inhibition, cell cycle effects, and apoptosis induction. Mechanistic studies involved analysis of Rheb prenylation required for mTOR activation. Results: A strong synergy of CHR2863 with the statins simvastatin, fluvastatin, lovastatin, and pravastatin was demonstrated in U937 cells and two CHR2863-resistant sublines. This potent synergy between simvastatin and CHR2863 was also observed with a series of other human AML cell lines (e.g., THP1, MV4-11, and KG1), but not with acute lymphocytic leukemia or multiple solid tumor cell lines. This synergistic activity was: (i) specific for APis (e.g., CHR2863 and Bestatin), rather than for other cytotoxic agents; and (ii) corroborated by enhanced induction of apoptosis and cell cycle arrest which increased the sub-G1 fraction. Consistently, statin potentiation of CHR2863 activity was abrogated by co-administration of mevalonate and/or farnesyl pyrophosphate, suggesting the involvement of protein prenylation; this was experimentally confirmed by impaired Rheb prenylation by simvastatin. Conclusion: These novel findings suggest that the combined inhibitory effect of impaired Rheb prenylation and CHR2863-dependent mTOR inhibition instigates a potent synergistic inhibition of statins and APis on human AML cells.

Association of Statin Use With Risk of Liver Disease, Hepatocellular Carcinoma, and Liver-Related Mortality

Importance

Given the burden of chronic liver disease on the health care system, more information on the hepatoprotective association of statins in the general population is needed.

Objective

To examine whether regular statin use is associated with a reduction in liver disease, particularly hepatocellular carcinoma (HCC) and liver-related deaths, in the general population.

Design, Setting, and Participants

This cohort study used data from the UK Biobank (UKB) (individuals aged 37-73 years) collected from baseline (2006-2010) to the end of follow-up in May 2021, from the TriNetX cohort (individuals aged 18-90 years) enrolled from baseline (2011-2020) until end of follow-up in September 2022, and from the Penn Medicine Biobank (PMBB) (individuals aged 18-102 years) with ongoing enrollment starting in 2013 to the end of follow-up in December 2020. Individuals were matched using propensity score matching according to the following criteria: age, sex, body mass index, ethnicity, diabetes with or without insulin or biguanide use, hypertension, ischemic heart disease, dyslipidemia, aspirin use, and number of medications taken (UKB only). Data analysis was performed from April 2021 to April 2023.

Exposure

Regular statin use.

Main Outcomes and Measures

Primary outcomes were liver disease and HCC development as well as liver-associated death.

Results

A total of 1 785 491 individuals were evaluated after matching (aged 55 to 61 years on average, up to 56% men, and up to 49% women). A total of 581 cases of liver-associated death, 472 cases of incident HCC, and 98 497 new liver diseases were registered during the follow-up period. Individuals were aged 55-61 years on average, with a slightly higher proportion of men (up to 56%). In UKB individuals (n = 205 057) without previously diagnosed liver disease, statin users (n = 56 109) had a 15% lower hazard ratio (HR) for the association of developing a new liver disease (HR, 0.85; 95% CI, 0.78-0.92; P < .001). In addition, statin users demonstrated a 28% lower HR for the association with liver-related death (HR, 0.72; 95% CI, 0.59-0.88; P = .001) and a 42% lower HR for the development of HCC (HR, 0.58; 95% CI, 0.35-0.96; P = .04). In TriNetX individuals (n = 1 568 794), the HR for the association of HCC was reduced even further for statin users (HR, 0.26; 95% CI, 0.22-0.31; P = .003). The hepatoprotective association of statins was time and dose dependent, with a significant association in PMBB individuals (n = 11 640) for incident liver diseases after 1 year of statin use (HR, 0.76; 95% CI, 0.59-0.98; P = .03). Taking statins was particularly beneficial in men, individuals with diabetes, and individuals with a high Fibrosis-4 index at baseline. Carriers of the heterozygous minor allele of PNPLA3 rs738409 benefited from statin use and had a 69% lower HR for the association with HCC (UKB HR, 0.31; 95% CI, 0.11-0.85; P = .02).

Conclusions and Relevance

This cohort study indicates substantial preventive associations of statins against liver disease, with an association with duration and dose of intake.

Metabolism in Hematopoiesis and Its Malignancy

Hematopoietic stem cells (HSCs) are multipotent stem cells that can self-renew and generate all blood cells of different lineages. The system is under tight control in order to maintain a precise equilibrium of the HSC pool and the effective production of mature blood cells to support various biological activities. Cell metabolism can regulate different molecular activities, such as epigenetic modification and cell cycle regulation, and subsequently affects the function and maintenance of HSC. Upon malignant transformation, oncogenic drivers in malignant hematopoietic cells can remodel the metabolic pathways for supporting the oncogenic growth. The dysregulation of metabolism results in oncogene addiction, implying the development of malignancy-specific metabolism-targeted therapy. In this chapter, we will discuss the significance of different metabolic pathways in hematopoiesis, specifically, the distinctive metabolic dependency in hematopoietic malignancies and potential metabolic therapy.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Computational pharmacogenomic screen identifies drugs that potentiate the anti-breast cancer activity of statins

Statins, a family of FDA-approved cholesterol-lowering drugs that inhibit the rate-limiting enzyme of the mevalonate metabolic pathway, have demonstrated anticancer activity. Evidence shows that dipyridamole potentiates statin-induced cancer cell death by blocking a restorative feedback loop triggered by statin treatment. Leveraging this knowledge, we develop an integrative pharmacogenomics pipeline to identify compounds similar to dipyridamole at the level of drug structure, cell sensitivity and molecular perturbation. To overcome the complex polypharmacology of dipyridamole, we focus our pharmacogenomics pipeline on mevalonate pathway genes, which we name mevalonate drug-network fusion (MVA-DNF). We validate top-ranked compounds, nelfinavir and honokiol, and identify that low expression of the canonical epithelial cell marker, E-cadherin, is associated with statin-compound synergy. Analysis of remaining prioritized hits led to the validation of additional compounds, clotrimazole and vemurafenib. Thus, our computational pharmacogenomic approach identifies actionable compounds with pathway-specific activities.

The Impact of Statin Use and Breast Cancer Recurrence - A Retrospective Study in Singapore

Introduction

Statins, HMG-CoA reductase inhibitors, are commonly used cholesterol-lowering medications which are also increasingly recognized to have anti-cancer properties for various cancers, including breast cancer. Most clinical evidence supports a protective effect of statin on reducing breast cancer recurrence, particularly in hormone-receptor positive breast cancers.This study seeks to study the impact of statin use on breast cancer recurrence in an Asian population.

Methods

This is a retrospective study of patients diagnosed with breast cancer at the National Cancer Centre and Singapore General Hospital from 2005-2015. Statin use was defined as use after surgery. Associations between statin use, breast cancer recurrence and overall survival were estimated using Cox proportional hazards regression with adjustment for age, TNM stage, grade, ER/HER2 status, and co-morbidities. Associations between statin-use and disease-specific survival were estimated using competing risks regression.

Results

A total of 7858 females with breast cancer were studied, 1353(17.2%) were statin users, 6505(82.8%) were non-statin users, with a median follow-up of 8.67 years. Distribution of cancer stage, histology, molecular subtypes and grades were similar in both groups. Estrogen receptor(ER) positive (HR 0.57,95%CI 0.43-0.76,p<0.001) and HER2 negative (HR 0.74,95%CI 0.57-0.96,p=0.026) invasive cancers had a lower risk of recurrence in statin users. Statin users trended towards a long term recurrence-risk reduction (all subtypes,HR 0.48,p=0.002; ER-, HR 0.34,p=0.036; HER2+,HR 0.10,p=0.002). The risk-reduction benefit is not appreciated in statin users with DCIS, possibly due to small recurrence event numbers. Disease-specific survival benefit was seen in statin users with ER+ cancers (adjusted SHR 0.71,95%CI 0.53-0.96,p=0.027), especially ER+ invasive cancers (adjusted SHR 0.72, 95%CI 0.53-0.97,p=0.028), but with no statistically significant benefit in overall survival for statin users (all subtypes).

Conclusion

This is the first known retrospective study on the effect of statin use and breast cancer recurrence in an Asian population. Similar to previous international studies, statin use is associated with a risk reduction in breast cancer recurrence. This is especially beneficial in patients who have ER+ and HER2- invasive breast cancer. Statin use is also associated with a reduced risk of breast cancer recurrence in all subtypes of breast cancer in the long term (>6 years post diagnosis).

Statins Decrease Programmed Death-Ligand 1 (PD-L1) by Inhibiting AKT and β-Catenin Signaling

Retrospective observational studies have reported that statins improve clinical outcomes in patients previously treated with programmed cell death protein 1 (PD-1)-targeting monoclonal antibodies for malignant pleural mesothelioma (MPM) and advanced non-small cell lung cancer (NSCLC). In multiple mouse cancer models, de novo synthesis of mevalonate and cholesterol inhibitors was found to synergize with anti-PD-1 antibody therapy. In the present study, we investigated whether statins affect programmed death-ligand 1 (PD-L1) expression in cancer cells. Four statins, namely simvastatin, atorvastatin, lovastatin, and fluvastatin, decreased PD-L1 expression in melanoma and lung cancer cells. In addition, we found that AKT and β-catenin signaling involved PD-L1 suppression by statins. Our cellular and molecular studies provide inspiring evidence for extending the clinical evaluation of statins for use in combination with immune checkpoint inhibitor-based cancer therapy.

Targeting obesity-related dysfunction in hormonally driven cancers

Obesity is a risk factor for at least 13 different types of cancer, many of which are hormonally driven, and is associated with increased cancer incidence and morbidity. Adult obesity rates are steadily increasing and a subsequent increase in cancer burden is anticipated. Obesity-related dysfunction can contribute to cancer pathogenesis and treatment resistance through various mechanisms, including those mediated by insulin, leptin, adipokine, and aromatase signalling pathways, particularly in women. Furthermore, adiposity-related changes can influence tumour vascularity and inflammation in the tumour microenvironment, which can support tumour development and growth. Trials investigating non-pharmacological approaches to target the mechanisms driving obesity-mediated cancer pathogenesis are emerging and are necessary to better appreciate the interplay between malignancy, adiposity, diet and exercise. Diet, exercise and bariatric surgery are potential strategies to reverse the cancer-promoting effects of obesity; trials of these interventions should be conducted in a scientifically rigorous manner with dose escalation and appropriate selection of tumour phenotypes and have cancer-related clinical and mechanistic endpoints. We are only beginning to understand the mechanisms by which obesity effects cell signalling and systemic factors that contribute to oncogenesis. As the rates of obesity and cancer increase, we must promote the development of non-pharmacological lifestyle trials for the treatment and prevention of malignancy.

The Association Between Statin Use and Outcomes in Patients Initiating Androgen Deprivation Therapy

BACKGROUND

Studies have conflicting results regarding the association between statin use and biochemical recurrence for prostate cancer (PCa). A limited number of studies examining statins in advanced stages report positive results, with a few specifically examining statins and androgen deprivation therapy (ADT).

OBJECTIVE

To perform a post hoc secondary analysis of a randomised controlled trial (RCT) of men initiating ADT to examine the association between statin use and outcomes.

DESIGN, SETTING, AND PARTICIPANTS

Patients with prostate-specific antigen (PSA) >3 ng/ml >1 yr following primary/salvage radiotherapy were enrolled in an RCT of intermittent androgen deprivation (IAD) versus continuous ADT (NCT00003653). Baseline and on-study statin use was modelled as a time-dependent covariate.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was overall survival. Models were adjusted for age, time from radiotherapy to ADT, baseline PSA, and prior ADT.

RESULTS AND LIMITATIONS

Of 1364 patients, statin users (585; 43%) were younger (72.7 vs 73.8 yr, p = 0.001) and less likely to have PSA >15 ng/ml (20% vs 25%, p = 0.04). After a median follow-up of 6.9 yr, statin use was associated with reduced overall (hazard ratio [HR]: 0.64; 95% confidence interval [CI] 0.53-0.78, p < 0.001) and PCa-specific (HR: 0.65, 95% CI 0.48-0.87, p = 0.004) mortality. Statin users had 13% longer time to castration resistance, but this did not reach statistical significance (p = 0.15). As an exploratory endpoint, in the IAD arm, statin users had longer time off treatment (median: 0.85 vs 0.64 yr, p = 0.06). Limitations include potential for residual confounding between statin users and nonusers, and confounding by indication.

CONCLUSIONS

In men treated with ADT following primary or salvage radiotherapy, statin use was associated with improved overall and PCa-specific survival. In patients treated with IAD, statin use was associated with a trend towards longer time off treatment. A prospective trial of statins in men commencing ADT is warranted.

PATIENT SUMMARY

We found a favourable association between statin use and survival outcomes in patients initiating androgen deprivation therapy.

Simvastatin enhances the efficacy of nilotinib in chronic myeloid leukaemia by post-translational modification and drug transporter modulation

The resistance of chronic myeloid leukaemia (CML) to tyrosine kinase inhibitors (TKIs) remains a significant clinical problem. Targeting alternative pathways, such as protein prenylation, is known to be effective in overcoming resistance. Simvastatin inhibits 3-hydroxy-3-methylglutaryl-CoA reductase (a key enzyme in isoprenoid-regulation), thereby inhibiting prenylation. We demonstrate that simvastatin alone effectively inhibits proliferation in a panel of TKI-resistant CML cell lines, regardless of mechanism of resistance. We further show that the combination of nilotinib and simvastatin synergistically kills CML cells via an increase in apoptosis and decrease in prosurvival proteins and cellular proliferation. Mechanistically, simvastatin inhibits protein prenylation as shown by increased levels of unprenylated Ras and rescue experiments with mevalonate resulted in abrogation of synergism. The combination also leads to an increase in the intracellular uptake and retention of radio-labelled nilotinib, which further enhances the inhibition of Bcr-Abl kinase activity. In primary CML samples, this combination inhibits clonogenicity in both imatinib-naive and resistant cells. Such combinatorial effects provide the basis for utilising these Food and Drug Administration-approved drugs as a potential clinical approach in overcoming resistance and improving CML treatment.

Co-Medication and Nutrition in Hepatocellular Carcinoma: Potentially Preventative Strategies in Hepatocellular Carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide, with about 841,000 new cases and 782,000 deaths annually. Given the clearly defined population at risk, mostly patients with liver cirrhosis, prevention of HCC could be highly effective.

SUMMARY

Besides regular ultrasound surveillance, numerous publications have suggested protective effects of diverse drugs and nutrients. However, none of those preventive options has made it into clinical routine or practice guidelines. We therefore summarize the current status of preventive effects of drugs such as statins, acetylsalicylic acid (ASA), and metformin, but also dietary aspects and nutrients such as coffee, tea, and vitamin D supplementation. A successful implementation of some of these strategies may potentially lead to improved prevention of HCC development in patients with liver cirrhosis. Key Messages: Accumulating data suggest that particularly ASA, antidiabetic therapies, and statins may substantially decrease HCC incidence in patients at risk.

Atorvastatin potentiates the chemosensitivity of human liver cancer cells to cisplatin via downregulating YAP1

Atorvastatin is a competitive inhibitor of β-hydroxy β-methylglutaryl-CoA reductase, which is involved in anticancer effects in numerous types of cancer, including in human liver cancer. However, its functions and underlying mechanisms of chemosensitivity in liver cancer remain to be elucidated. The present study investigated the effect of atorvastatin on cisplatin chemosensitivity and its molecular mechanisms, with a focus on the Yes1-associated transcriptional regulator (YAP1) protein. The present study demonstrated that atorvastatin significantly potentiated chemosensitivity to cisplatin in the liver cancer HepG2 and Huh-7 cell lines. Furthermore, cell survival and apoptosis in liver cancer cell lines were analyzed using MTT assay and flow cytometry, respectively. Atorvastatin suppressed HepG2 and Huh-7 cell viability in a dose-dependent manner, similar to cisplatin and paclitaxel. Subtoxic levels of atorvastatin significantly increased cisplatin-induced apoptosis in Huh-7 cells. Atorvastatin-promoted chemosensitivity was predominantly mediated by caspase 3, caspase 9 and poly-(ADP ribose)-polymerase activation, and YAP1 downregulation. Finally, YAP1 overexpression significantly reversed the susceptibility of Huh-7 cells to cisplatin. Overall, the results of the present study suggested the underlying mechanisms of atorvastatin chemosensitivity in inducing liver cancer cell apoptosis via downregulating YAP1 and implicated the potential application of atorvastatin-potentiated chemosensitivity in liver cancer therapy.

Hepatocellular Carcinoma and Statins

HMG-CoA reductase inhibitors (known as statins) are commonly prescribed worldwide for the management of coronary heart disease and the underlying dyslipidemia. This class of drugs has been shown to infer a significant decrease in the risk of cardiovascular morbidity and mortality. Only recently though have the beneficial effects of statins in other diseases such as non-alcoholic steatohepatitis been highlighted. Importantly, also, multiple studies have revealed that statin use was associated with lower cancer-associated mortality across multiple types of cancers. This work aims to review those studies with a particular focus on liver cancer. We also provide a review of the proposed mechanisms of action describing how statins can induce chemo-preventive and antitumor effects.

TNFAIP8 promotes AML chemoresistance by activating ERK signaling pathway through interaction with Rac1

Background

Chemoresistance is emerging as a major barrier to successful treatment in acute myeloid leukemia (AML), and evasion of apoptosis is among the fundamental underlying mechanisms. Therefore, unraveling molecular networks that drive this process constitutes an urgent unmet need. Herein, we aim to characterize the role and molecular mechanism of the tumor necrosis factor ɑ-induced protein 8 (TNFAIP8), a novel anti-apoptotic molecule, in AML chemoresistance.

Methods

The expression levels of TNFAIP8 were assessed in AML patients and cell lines by RT-qPCR and western blots. The transcriptional regulation of TNFAIP8 was analyzed with luciferase reporter assay and ChIP followed by RT-qPCR. Functional experiments were conducted to evaluate the effects of TNFAIP8 on apoptosis, drug sensitivity and proliferation of AML cells. Potential effects of TNFAIP8 on the activation of extracellular signal-regulated kinase (ERK) pathway were detected by western blots. CoIP and P21-activated kinase (PAK) pull-down assay were performed to ascertain the upstream target. The overall effects of TNFAIP8 on AML were examined in murine models.

Results

Upregulated TNFAIP8 expression was first confirmed in human AML patients and cell lines. E74 like ETS transcription factor 1 (ELF1) was then identified to contribute to its aberrant expression. Through manipulating TNFAIP8 expression, we described its role in protecting AML cells from apoptosis induced by chemotherapeutic agents and in promoting drug resistance. Notably, the leukemia-promoting action of TNFAIP8 was mediated by sustaining activity of the ERK signaling pathway, through an interaction with Rac family small GTPase 1 (Rac1). In addition, in vivo experiments confirmed that TNFAIP8 suppression lowered leukemia infiltration and improved survival.

Conclusion

Our data provide a molecular basis for the role of TNFAIP8 in chemoresistance and progression of AML and highlight the unique function of TNFAIP8 as an attractive therapeutic target.

Statins Reduce Intratumor Cholesterol Affecting Adrenocortical Cancer Growth

Mitotane causes hypercholesterolemia in patients with adrenocortical carcinoma (ACC). We suppose that cholesterol increases within the tumor and can be used to activate proliferative pathways. In this study, we used statins to decrease intratumor cholesterol and investigated the effects on ACC growth related to estrogen receptor α (ERα) action at the nuclear and mitochondrial levels. We first used microarray to investigate mitotane effect on genes involved in cholesterol homeostasis and evaluated their relationship with patients' survival in ACC TCGA. We then blocked cholesterol synthesis with simvastatin and determined the effects on H295R cell proliferation, estradiol production, and ERα activity in vitro and in xenograft tumors. We found that mitotane increases intratumor cholesterol content and expression of genes involved in cholesterol homeostasis, among them INSIG, whose expression affects patients' survival. Treatment of H295R cells with simvastatin to block cholesterol synthesis decreased cellular cholesterol content, and this affected cell viability. Simvastatin reduced estradiol production and decreased nuclear and mitochondrial ERα function. A mitochondrial target of ERα, the respiratory complex IV (COXIV), was reduced after simvastatin treatment, which profoundly affected mitochondrial respiration activating apoptosis. Additionally, simvastatin reduced tumor volume and weight of grafted H295R cells, intratumor cholesterol content, Ki-67 and ERα, COXIV expression and activity and increase terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells. Collectively, these data demonstrate that a reduction in intratumor cholesterol content prevents estradiol production and inhibits mitochondrial respiratory chain-inducing apoptosis in ACC cells. Inhibition of mitochondrial respiration by simvastatin represents a novel strategy to counteract ACC growth.

Metabolic dependencies and vulnerabilities in leukemia

In this Review, Rashkovan et al. discuss the role of cancer metabolic circuitries feeding anabolism and redox potential in leukemia development and recent progress in translating these important findings to the clinic.

Leukemia cell proliferation requires up-regulation and rewiring of metabolic pathways to feed anabolic cell growth. Oncogenic drivers directly and indirectly regulate metabolic pathways, and aberrant metabolism is central not only for leukemia proliferation and survival, but also mediates oncogene addiction with significant implications for the development of targeted therapies. This review explores leukemia metabolic circuitries feeding anabolism, redox potential, and energy required for tumor propagation with an emphasis on emerging therapeutic opportunities.

Dual FLT3 inhibitors: Against the drug resistance of acute myeloid leukemia in recent decade

Acute myeloid leukemia (AML) is a malignant disease characterized by abnormal growth and differentiation of hematopoietic stem cells. Although the pathogenesis has not been fully elucidated, many specific gene mutations have been found in AML. Fms-like tyrosine kinase 3 (FLT3) is recognized as a drug target for the treatment of AML, and the activation mutations of FLT3 were found in about 30% of AML patients. Targeted inhibition of FLT3 receptor tyrosine kinase has shown promising results in the treatment of FLT3 mutation AML. Unfortunately, the therapeutic effects of FLT3 tyrosine kinase inhibitors used as AML monotherapy are usually accompanied by the high risk of resistance development within a few months after treatment. FLT3 dual inhibitors were generated with the co-inhibition of FLT3 and another target, such as CDK4, JAK2, MEK, Mer, Pim, etc., to solve the problems mentioned above. As a result, the therapeutic effect of the drug is significantly improved, while the toxic and side effects are reduced. Besides, the life quality of AML patients with FLT3 mutation has been effectively improved. In this paper, we reviewed the studies of dual FLT3 inhibitors that have been discovered in recent years for the treatment of AML.

Myelodysplastic Syndrome related alterations of MAPK signaling in the bone marrow of experimental mice including stem/progenitor compartment

Myelodysplastic syndrome is considered globally as heterogenous group of neoplasm which often proclaims leukemic progression. The heterogeneity is reflected not only in clinical manifestations of the disease but also in salient causes of disease development. In spite of multiple therapeutic modalities, shortfall towards treatment of this disorder still persists. The focal point of tussle suggested toward defects, which are not confined to any unifying cellular signalling. The pathobiology of the disease often experiences an intriguing paradox involving 'hyperproliferative bone marrow with pancytopenic peripheral blood'. In our present study we have reported about MAPK signaling in the hematopoietic stem progenitor compartmental (HSPC) dysregulation during the course of alkylator(ENU) induced myelodysplasia. The phospho-protein status of RTK's(FLT3, PDGFR, EGFR) were markedly increased that activated MAPK signaling proteins which finally executed their tasks by transcription of c-Myc and Rb leading to uncontrolled cellular proliferation, simultaneously the activated c-Jun revealed stress related apoptosis. Altogether, the role of activated MAPK signaling in the HSPC's may have led to hyperproliferation and concurrent enhanced apoptosis of abnormal cells which gradually headed towards premalignant transformations during the course of disease. The phenotypic expression of the HSPC markers CD 150 and CD 90 also established a mechanistic correlation with MAPK signalling alterations and overall scenario.

MEK nuclear localization promotes YAP stability via sequestering β-TrCP in KRAS mutant cancer cells

Tumours manage to survive the ablation of mutant KRAS, despite the development of KRAS-targeted drugs. Here we describe that inhibition of mutant KRAS promotes MEK nuclear localization as an alternative mechanism of KRAS-targeted drugs resistance. Tissue microarray analysis in colon tumours shows that aberrant MEK nuclear localization is closely related to YAP levels and tumour malignancy. MEK nuclear localization could sequester β-TrCP from cytoplasmic inactive YAP, then stabilizing YAP. Mutant KRAS restrains MEK within the cytoplasm via IQGAP1, inhibiting MEK nuclear translocation. Trametinib, an allosteric MEK inhibitor, could prevent MEK nuclear localization and subsequently promote YAP degradation. In vitro and in vivo results suggests that inhibition of MEK nuclear localization by trametinib synergizes with KRAS knockdown or deltarasin treatment in suppressing the viability of KRAS mutant colon cancer cells. Our study provides new insights into the mechanisms of resistance to KRAS ablation, and suggests novel strategies for the treatment of KRAS-mutant colon cancers.

Total Serum Cholesterol and Pancreatic Cancer: A Nested Case-Control Study

BACKGROUND

Pancreatic cancer is the third leading cause of cancer-related death in the United States. Total serum cholesterol (TSC) may predict cancer risk, although its role independent of statins remains elusive. We examined the association between TSC and pancreatic cancer risk independent of statins.

METHODS

A nested case-control analysis was conducted among statin-naïve patients within The Health Improvement Network (THIN), a United Kingdom-based general practice database. Cases were >40 years old and diagnosed with pancreatic cancer after at least 6 months of follow-up. Controls were selected by incidence density sampling and matched by age, sex, practice site, and follow-up. Primary exposure was TSC (mmol/L) prior to index date. Conditional logistic regression estimated ORs for pancreatic cancer risk associated with TSC. Sensitivity analyses were conducted among nondiabetics.

RESULTS

Among 1,241 cases and 3,307 matched controls, an average 8% reduction was observed in pancreatic cancer risk per mmol/L increase in TSC [OR 0.92, 95% confidence interval (CI): 0.85-1.00; nondiabetics: OR 0.91, 95% CI: 0.83-0.99]. When TSC was measured at 12-month intervals prior to diagnosis, the OR between TSC and pancreatic cancer was 0.88 at 0 to 12 months (95% CI: 0.77-1.00; nondiabetics: OR 0.81, 95% CI: 0.68-0.96). No significant association was seen at subsequent discrete intervals before index date.

CONCLUSIONS

TSC is a significant predictor of short-term risk for pancreatic cancer. This risk increase associated with lower TSC was independent of statins.

IMPACT

TSC could serve as a biomarker for risk stratification, screening, and early diagnosis of pancreatic cancer in future clinical prediction models.

Amino alkynylisoquinoline and alkynylnaphthyridine compounds potently inhibit acute myeloid leukemia proliferation in mice

BACKGROUND

Acute myeloid leukemia (AML) remains one of the most lethal, rarely cured cancers, despite decades of active development of AML therapeutics. Currently, the 5-year survival of AML patients is about 30% and for elderly patients, the rate drops to <10%. About 30% of AML patients harbor an activating mutation in the tyrosine kinase domain (TKD) of Fms-Like Tyrosine kinase 3 (FLT3) or a FLT3 internal tandem duplication (FLT3-ITD). Inhibitors of FLT3, such as Rydapt that was recently approved by the FDA, have shown good initial response but patients often relapse due to secondary mutations in the FLT3 TKD, like D835Y and F691 L mutations.

METHODS

Alkynyl aminoisoquinoline and naphthyridine compounds were synthesized via Sonogashira coupling. The compounds were evaluated for their in vitro and in vivo effects on leukemia growth.

FINDINGS

The compounds inhibited FLT3 kinase activity at low nanomolar concentrations. The lead compound, HSN431, also inhibited Src kinase activity. The compounds potently inhibited the viability of MV4-11 and MOLM-14 AML cells with IC50 values <1 nM. Furthermore, the viability of drug-resistant AML cells harboring the D835Y and F691 L mutations were potently inhibited. In vivo efficacy studies in mice demonstrated that the compounds could drastically reduce AML proliferation in mice.

INTERPRETATION

Compounds that inhibit FLT3 and downstream targets like Src (for example HSN431) are good leads for development as anti-AML agents. FUND: Purdue University, Purdue Institute for Drug Discovery (PIDD), Purdue University Center for Cancer Research, Elks Foundation and NIH P30 CA023168.

The Roles of Cholesterol and Its Metabolites in Normal and Malignant Hematopoiesis

Hematopoiesis is sustained throughout life by hematopoietic stem cells (HSCs) that are capable of self-renewal and differentiation into hematopoietic progenitor cells (HPCs). There is accumulating evidence that cholesterol homeostasis is an important factor in the regulation of hematopoiesis. Increased cholesterol levels are known to promote proliferation and mobilization of HSCs, while hypercholesterolemia is associated with expansion of myeloid cells in the peripheral blood and links hematopoiesis with cardiovascular disease. Cholesterol is a precursor to steroid hormones, oxysterols, and bile acids. Among steroid hormones, 17β-estradiol (E2) induces HSC division and E2-estrogen receptor α (ERα) signaling causes sexual dimorphism of HSC division rate. Oxysterols are oxygenated derivatives of cholesterol and key substrates for bile acid synthesis and are considered to be bioactive lipids, and recent studies have begun to reveal their important roles in the hematopoietic and immune systems. 27-Hydroxycholesterol (27HC) acts as an endogenous selective estrogen receptor modulator and induces ERα-dependent HSC mobilization and extramedullary hematopoiesis. 7α,25-dihydroxycholesterol (7α,25HC) acts as a ligand for Epstein-Barr virus-induced gene 2 (EBI2) and directs migration of B cells in the spleen during the adaptive immune response. Bile acids serve as chemical chaperones and alleviate endoplasmic reticulum stress in HSCs. Cholesterol metabolism is dysregulated in hematologic malignancies, and statins, which inhibit de novo cholesterol synthesis, have cytotoxic effects in malignant hematopoietic cells. In this review, recent advances in our understanding of the roles of cholesterol and its metabolites as signaling molecules in the regulation of hematopoiesis and hematologic malignancies are summarized.

Statin use is associated to a reduced risk of pancreatic cancer: A meta-analysis

BACKGROUND

Previous studies investigating the association between statin use and pancreatic cancer (PDAC) risk for a possible chemopreventive effect gathered heterogeneous results.

AIMS

To conduct a systematic review and meta-analysis to clarify this association.

METHODS

Comprehensive literature search of articles published up to February 2018, including case-control (CC),cohort studies (C), randomized controlled trials (RCTs) assessing association between statin use and PDAC risk. Studies had to report odds ratio (OR)/relative risk (RR), estimates with 95% confidence interval (CI), or provide data for their calculation. Pooled ORs with 95%CIs were calculated using random effects model, publication bias through Begg and Mazumdar test and heterogeneity by I² value.

RESULTS

27 studies(13 CC, 9C, 5 RCTs) for a total population of 11,975 PDAC/3,433,175 controls contributed to the analysis. The overall pooled result demonstrated a reduced PDAC risk among statin users (OR 0.70; 95% CI 0.60-0.82; p < 0.0001), compared to non-users. Sensitivity analyses suggested the risk reduction to be more important in CC studies, studies conducted in Asia and Europe, in males and atorvastatin users. No publication bias found.

CONCLUSIONS

The present meta-analysis suggests that statin use is associated with an overall PDAC risk reduction of 30%. Further studies are needed to clarify the association.

Statin use and histopathological change in patients with non-alcoholic fatty liver disease: a systematic review and meta-analysis

Background

Non-alcoholic fatty liver disease (NAFLD) is one of the major causes of chronic liver disease. The primary treatment of NAFLD by statins has not been clearly elucidated.

Objectives

To evaluate the effectiveness of statin use in patients with biopsy-proven NAFLD or non-alcoholic steatohepatitis on the change in liver histology.

Methods

We searched MEDLINE, Scopus, Google Scholar, and the Cochrane Central Register of Controlled Trials for clinical trials and observational studies investigating the effects of statins on histological change regardless of type or dosage from inception to December 2015. Random-effect model meta-analyses were used to compute changes in outcomes of interest. The study protocol was registered in advance with the International Prospective Register of Systematic Reviews (PROSPERO 2016 CRD42016033132).

Results

We identified 6 studies (111 patients), representing 5 cohort studies and 1 randomized controlled clinical trial. There was significant decrease in steatosis grading with a standardized mean difference of –2.580 (95% confidence interval [CI] –4.623 to –0.536; P = 0.013) and NAFLD activity score standardized mean difference of –1.488 (95% CI –2.506 to –0.471; P = 0.004). However, there was no significant change in fibrosis stage (0.156; 95% CI –0.553 to 0.865; P = 0.667).

Conclusions

Statin use can possibly reduce the extent of steatohepatitis but not the stage of fibrosis. Further randomized controlled studies to assess histological evidence with adequate sample size and duration are required in order to establish the role of statin as a primary treatment of NAFLD.

Orostachys japonicus induce p53-dependent cell cycle arrest through the MAPK signaling pathway in OVCAR-3 human ovarian cancer cells

Orostachys japonicus (O. japonicus) is utilized as a traditional medicine for patients with various diseases. This study investigated the effect of the ethyl acetate fraction from O. japonicus extract (OJE) on the growth inhibition of OVCAR-3 human ovarian cancer cells demonstrated to inhibit cell growth and arrest the cell cycle in OVCAR-3 cells by blocking the sub-G1 phase and decreasing cyclin E1/CDK2 expression. Cell cycle arrest was connected to the increased expression of the cell cycle regulating factors p53 and p21. Apoptosis was initiated through the intrinsic pathway by up-regulating the expression of the Bcl-2/Bax ratio and down-regulating the expression of pro-caspase-3. Furthermore, OJE treatment elicited p-p38 activation and p-ERK1/2 inhibition. In conclusion, our results demonstrated that OJE reduced the growth of OVCAR-3 human ovarian cancer cells mediated by arrest of the cell cycle and regulation of MAPK signaling pathways.

Impact of postdiagnostic statin use on ovarian cancer mortality: A systematic review and meta-analysis of observational studies

AIMS

To comprehensively evaluate the association between postdiagnostic statin use and mortality of ovarian cancer (OC) patients.

METHODS

Using a comprehensive strategy, multiple databases (Medline, Embase and Web of Science) were systematically searched to identify observational studies that examined the correlation between statin use and OC mortality up to 31 December 2017. The studies were independently reviewed and selected based on predetermined selection criteria. Data were extracted independently and in duplicate. The risk of bias was evaluated with the Newcastle-Ottawa scale. Hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality were summarized with a profile likelihood random effects model.

RESULTS

Of 269 studies, eight cohort studies of 19 904 OC patients met the inclusion criteria. Postdiagnostic statin use was inversely associated with all-cause mortality/overall survival (summarized HR = 0.74; 95%CI = 0.63-0.87; I²  = 55%; n = 7) and cancer-specific mortality (summarized HR = 0.87; 95%CI = 0.80-0.95; I²  = 0%; n = 3) of OC patients. These findings were consistent by subgroup analyses stratified by study and patient characteristics as well as adjustments made for potential confounders. A meta-regression analysis found no effect of modification by these variables. Of note, similar significant inverse effects were also observed when increasing the intensity (highest vs. lowest) of postdiagnostic statin use (summarized HR = 0.84; 95%CI = 0.74-0.96; I²  = 0%; n = 3).

CONCLUSION

Postdiagnostic statin use can improve the survival of patients with OC. Further prospective cohort and randomized controlled trials are warranted to confirm the therapeutic role of statin use on the outcome of OC.

Statin use and risk of skin cancer

BACKGROUND

Statins are among the most commonly used medications in the United States, and statin use is associated with increased risk of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). However, previous studies are limited by lack of adjustment for important confounders.

OBJECTIVE

Examine the relation between statins and skin cancer risk in the Nurses' Health Study and Health Professionals Follow-up Study.

METHODS

Cox proportional hazards regression was used to evaluate associations.

RESULTS

During follow-up (2000-2010), we documented 10,201 BCC, 1393 SCC, and 333 melanoma cases. History of high cholesterol level was not associated with risk of BCC (pooled multivariable-adjusted hazard ratio [HR], 1.04; 95% confidence interval [CI], 1.00-1.09), SCC (HR, 0.95; 95% CI, 0.85-1.06), or melanoma (HR, 0.87; 95% CI, 0.64-1.19). Statin use was not associated with risk of BCC (HR, 1.04; 95% CI, 0.99-1.09]), SCC (HR, 1.08; 95% CI, 0.94-1.24), or melanoma (HR, 1.04; 95% CI, 0.78-1.38). There was a trend toward higher BCC risk with longer duration of statin use in men (P trend = .003) but not in women (P trend = .86).

LIMITATIONS

Lack of treatment data.

CONCLUSION

History of high cholesterol level was not associated with skin cancer risk. Longer duration of statin use was associated with a trend toward higher BCC risk in men.

The role of atorvastatin in suppressing tumor growth of uterine fibroids

Background

Medical therapeutic options remain quite limited for uterine fibroids treatment. Statins, competitive inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, have anti-tumoral effects on multiple cancer types, however, little is known about their effects on uterine fibroids.

Methods

Initially, we conducted a retrospective study of 120 patients with uterine fibroids and hyperlipidemia from the Second Affiliated Hospital of Wenzhou Medical University. Then, we evaluated the effect of atorvastatin on proliferation and apoptosis both in immortalized uterine fibroids cells and primary uterine fibroids cells. Furthermore, the molecular mechanism by which atorvastatin suppressed uterine fibroids cell growth was explored.

Results

Our results showed that atorvastatin use for 1 or 2 years significantly suppressed growth of uterine fibroids. Atorvastatin inhibited the proliferation of immortalized and primary uterine fibroids cells in a dose and time-dependent manner and stimulated apoptosis of uterine fibroids cells by inducing caspase-3 activation, up-regulating Bim and down-regulating Bcl-2. Additionally, atorvastatin treatment suppressed phosphorylation of ERK1/2 and JNK. Furthermore, GGPP, a downstream lipid isoprenoid intermediate, significantly rescued the effect of atorvastatin.

Conclusions

These results suggest that atorvastatin exerts anti-tumoral effects on uterine fibroids through inhibition of cell proliferation and induction of apoptosis in HMG-CoA-dependent pathway. Our results provide the first clinical and preclinical data on the use of atorvastatin as a promising nonsurgical treatment option for uterine fibroids.

Targeting the RAS/MAPK pathway with miR-181a in acute myeloid leukemia

Deregulation of microRNAs' expression frequently occurs in acute myeloid leukemia (AML). Lower miR-181a expression is associated with worse outcomes, but the exact mechanisms by which miR-181a mediates this effect remain elusive. Aberrant activation of the RAS pathway contributes to myeloid leukemogenesis. Here, we report that miR-181a directly binds to 3′-untranslated regions (UTRs); downregulates KRAS, NRAS and MAPK1; and decreases AML growth. The delivery of miR-181a mimics to target AML cells using transferrin-targeting lipopolyplex nanoparticles (NP) increased mature miR-181a; downregulated KRAS, NRAS and MAPK1; and resulted in decreased phosphorylation of the downstream RAS effectors. NP-mediated upregulation of miR-181a led to reduced proliferation, impaired colony formation and increased sensitivity to chemotherapy. Ectopic expression of KRAS, NRAS and MAPK1 attenuated the anti-leukemic activity of miR-181a mimics, thereby validating the relevance of the deregulated miR-181a-RAS network in AML. Finally, treatment with miR-181a-NP in a murine AML model resulted in longer survival compared to mice treated with scramble-NP control. These data support that targeting the RAS-MAPK-pathway by miR-181a mimics represents a novel promising therapeutic approach for AML and possibly for other RAS-driven cancers.

Cilia loss sensitizes cells to transformation by activating the mevalonate pathway

Although cilia loss and cell transformation are frequently observed in the early stage of tumorigenesis, the roles of cilia in cell transformation are unknown. In this study, disrupted ciliogenesis was observed in cancer cells and pancreatic cancer tissues, which facilitated oncogene-induced transformation of normal pancreatic cells (HPDE6C7) and NIH3T3 cells through activating the mevalonate (MVA) pathway. Disruption of ciliogenesis up-regulated MVA enzymes through β catenin-T cell factor (TCF) signaling, which synchronized with sterol regulatory element binding transcription factor 2 (SREBP2), and the regulation of MVA by β-catenin-TCF signaling was recapitulated in a mouse model of pancreatic ductal adenocarcinoma (PDAC) and human PDAC samples. Moreover, disruption of ciliogenesis by depleting Tg737 dramatically promoted tumorigenesis in the PDAC mouse model, driven by KrasG12D , which was inhibited by statin, an inhibitor of the MVA pathway. Collectively, this study emphasizes the crucial roles of cilia in governing the early steps of the transformation by activating the MVA pathway, suggesting that statin has therapeutic potential for pancreatic cancer treatment.

Statin-Induced Cancer Cell Death Can Be Mechanistically Uncoupled from Prenylation of RAS Family Proteins

The statin family of drugs preferentially triggers tumor cell apoptosis by depleting mevalonate pathway metabolites farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP), which are used for protein prenylation, including the oncoproteins of the RAS superfamily. However, accumulating data indicate that activation of the RAS superfamily are poor biomarkers of statin sensitivity, and the mechanism of statin-induced tumor-specific apoptosis remains unclear. Here we demonstrate that cancer cell death triggered by statins can be uncoupled from prenylation of the RAS superfamily of oncoproteins. Ectopic expression of different members of the RAS superfamily did not uniformly sensitize cells to fluvastatin, indicating that increased cellular demand for protein prenylation cannot explain increased statin sensitivity. Although ectopic expression of HRAS increased statin sensitivity, expression of myristoylated HRAS did not rescue this effect. HRAS-induced epithelial-to-mesenchymal transition (EMT) through activation of zinc finger E-box binding homeobox 1 (ZEB1) sensitized tumor cells to the antiproliferative activity of statins, and induction of EMT by ZEB1 was sufficient to phenocopy the increase in fluvastatin sensitivity; knocking out ZEB1 reversed this effect. Publicly available gene expression and statin sensitivity data indicated that enrichment of EMT features was associated with increased sensitivity to statins in a large panel of cancer cell lines across multiple cancer types. These results indicate that the anticancer effect of statins is independent from prenylation of RAS family proteins and is associated with a cancer cell EMT phenotype.Significance: The use of statins to target cancer cell EMT may be useful as a therapy to block cancer progression. Cancer Res; 78(5); 1347-57. ©2017 AACR.

Impact of statin use on the prognosis of patients with hepatocellular carcinoma undergoing liver resection: a subgroup analysis of patients without chronic hepatitis viral infection

BACKGROUND

Statins have been reported to reduce the risk of hepatocellular carcinoma (HCC). The effect of perioperative statin use on the prognosis of HCC patients undergoing liver resection remains unclear.

METHODS

We retrospectively analyzed 643 patients who underwent curative liver resection for HCC. Patients negative for hepatitis B surface antigen and hepatitis C antibody were classified as the non-B non-C HCC subgroup (n = 204). Perioperative statin users were defined as patients preoperatively receiving statin medications and maintaining > 28 cumulative defined daily doses after liver resection. The recurrence-free survival (RFS) and overall survival (OS) according to statin use were analyzed in the overall HCC cohort or in the non-B non-C HCC subgroup.

RESULTS

Among a total of 643 (HCC) patients, 43 patients (6.7%) received perioperative statin medications. In statin users, the proportion of non-B non-C HCC patients was significantly higher than in nonstatin users. Statin users had a high prevalence of obesity and diabetes, as well as dyslipidemia. The liver function of statin users was better than that of nonstatin users. The multivariate survival analysis revealed that use of statins was significantly associated with improvement of RFS (hazard ratio [HR], .42; 95% confidence interval [CI], 0.25-0.71; P = .001), but not with OS (HR, 0.62; 95% CI, 0.30-1.27; P = .19). In the subgroup analysis of the non-B non-C HCC cohort, statin use was significantly associated with improvement of RFS (HR, 0.47; 95% CI, 0.22-0.99; P = .04).

CONCLUSION

Perioperative statin use was associated with an improvement of RFS in HCC patients undergoing curative liver resection.

Beneficial Effects of Statins on the Rates of Hepatic Fibrosis, Hepatic Decompensation, and Mortality in Chronic Liver Disease: A Systematic Review and Meta-Analysis

OBJECTIVES

Statins may improve outcomes in patients with chronic liver disease (CLD). We conducted a systematic review and meta-analysis to evaluate the impact of statins in the setting of CLD.

METHODS

We searched several databases from inception to 17 October 2016 to identify comparative studies evaluating the role of statins in CLD. Outcomes of interest were the associations between statin use and progression of fibrosis, development of hepatic decompensation in cirrhosis, and mortality in CLD. Adjusted hazard ratios (HRs) were pooled and analyzed using a random effects model. Subgroup analyses were performed based on the method of detection for progression of hepatic fibrosis and quality of studies.

RESULTS

We included 10 studies (1 randomized controlled trial and 9 observational) with 259,453 patients (54,441 statin users and 205,012 nonusers). For progression of hepatic fibrosis, pooled HR (95% confidence interval) was 0.49 (0.39-0.62). On subgroup analysis of studies using ICD-9 (The International Classification of Diseases, Ninth Revision) coding and a second method to detect cirrhosis, pooled HR was 0.58 (0.51-0.65); pooled HR for studies using ICD-9 coding only was 0.36 (0.29-0.44). For progression of fibrosis in patients with hepatitis C virus (HCV) infection, pooled HR was 0.52 (0.37-0.73). For hepatic decompensation in cirrhosis, pooled HR was 0.54 (0.46-0.65). For mortality, pooled HR based on observational studies was 0.67 (0.46-0.98); in the randomized controlled trial, HR was 0.39 (0.15-0.99). However, the quality of evidence for these associations is low as most included studies were retrospective in nature and limited by residual confounding.

CONCLUSIONS

Statins may retard the progression of hepatic fibrosis, may prevent hepatic decompensation in cirrhosis, and may reduce all-cause mortality in patients with CLD. As the quality (certainty) of evidence is low, further studies are needed before statins can be routinely recommended.

The sensitivity of head and neck carcinoma cells to statins is related to the expression of their Ras expression status, and statin-induced apoptosis is mediated via suppression of the Ras/ERK and Ras/mTOR pathways

Statins induce apoptosis of tumour cells by inhibiting the prenylation of small G-proteins. However, the details of the apoptosis-inducing mechanisms remain poorly understood. The present study showed that the induction of apoptosis by statins in four different human head and neck squamous cell carcinoma (HNSCC) cell lines, HSC-3, HEp-2, Ca9-22, and SAS cells was mediated by increased caspase-3 activity. Statins induced apoptosis by the suppression of geranylgeranyl pyrophosphate biosynthesis. Furthermore, statins decreased the levels of phosphorylated ERK and mTOR by inhibiting the membrane localization of Ras and enhancing Bim expression in HSC-3 and HEp-2 cells. We also found that in all the cell types analyzed, the IC₅₀ values for fluvastatin and simvastatin were highest in HEp-2 cells. In addition, HSC-3, Ca9-22, and SAS cells had higher Ras expression and membrane localization, higher activation of ERK1/2 and mTOR, and lower levels of Bim expression than HEp-2 cells. Our results indicate that statins induce apoptosis by increasing the activation of caspase-3 and by enhancing Bim expression through inhibition of the Ras/ERK and Ras/mTOR pathways. Furthermore, the sensitivity of HNSCC cells to statin treatment was closely related to Ras expression and prenylation levels, indicating that statins may act more effectively against tumours with high Ras expression and Ras-variability. Therefore, our findings support the use of statins as potential anticancer agents.

Protective Effects of Statins in Cancer: Should They Be Prescribed for High-Risk Patients?

PURPOSE OF REVIEW

Statins are one of the most widely prescribed drug classes in the USA. This review aims to summarize recent research on the relationship between statin use and cancer outcomes, in the context of clinical guidelines for statin use in patients with cancer or who are at high risk for cancer.

RECENT FINDINGS

A growing body of research has investigated the relationship between statins and cancer with mixed results. Cancer incidence has been more extensively studied than cancer survival, though results are inconsistent as some large meta-analyses have not found an association, while other studies have reported improved cancer outcomes with the use of statins. Additionally, two large studies reported increased all-cancer survival with statin use. Studies on specific cancer types in relation to cancer use have also been mixed, though the most promising results appear to be found in gastrointestinal cancers. Few studies have reported an increased risk of cancer incidence or decreased survival with statin use, though this type of association has been more commonly reported for cutaneous cancers. The overall literature on statins in relation to cancer incidence and survival is mixed, and additional research is warranted before any changes in clinical guidelines can be recommended. Future research areas include randomized controlled trials, studies on specific cancer types in relation to statin use, studies on populations without clinical indication for statins, elucidation of underlying biological mechanisms, and investigation of different statin types. However, studies seem to suggest that statins may be protective and are not likely to be harmful in the setting of cancer, suggesting that cancer patients who already take statins should not have this medication discontinued.

Statin Use After Diagnosis of Colon Cancer and Patient Survival

BACKGROUND & AIMS

Statin use has been associated with a reduced incidence of colorectal cancer and might also affect survival of patients diagnosed with colon cancer. Statins are believed to inhibit Ras signaling and may also activate the bone morphogenetic protein (BMP) signaling pathway in colorectal cancer cells. We investigated the effects of statins on overall survival of patients with a diagnosis of colon cancer, and whether their effects were associated with changes in KRAS or the BMP signaling pathways.

METHODS

Data were derived from the PHARMO database network (Netherlands) and linked to patients diagnosed with colon cancer from 2002 through 2007, listed in the Eindhoven Cancer Registry. We obtained information on causes of death from statistics Netherlands. We constructed a tissue microarray of 999 colon cancer specimens from patients who underwent surgical resection from 2002 through 2008. Survival was analyzed with statin user status after diagnosis as a time-dependent covariate. Multivariable Poisson regression survival models and Cox analyses were used to study the effect of statins on survival. Tumor tissues were analyzed by immunohistochemistry for levels of SMAD4, BMPR1A, BMPR1B, and BMPR2 proteins. Tumor tissues were considered to have intact BMP signaling if they contained SMAD4 plus BMPR1A, BMPR1B, or BMPR2. DNA was isolated from tumor tissues and analyzed by quantitative polymerase chain reaction to detect mutations in KRAS. The primary outcome measures were overall mortality and cancer-specific mortality.

RESULTS

In this cohort, 21.0% of the patients (210/999) were defined as statin users after diagnosis of colon cancer. Statin use after diagnosis was significantly associated with reduced risk of death from any cause (adjusted relative risk [RR], 0.67; 95% confidence interval [CI], 0.51-0.87; P = .003) and death from cancer (adjusted RR, 0.66; 95% CI, 0.49-0.89; P = .007). Statin use after diagnosis was associated with reduced risk of death from any cause or from cancer for patients whose tumors had intact BMP signaling (adjusted RR, 0.39; 95% CI, 0.22-0.68; P = .001), but not for patients whose tumors did not have BMP signaling (adjusted RR, 0.81; 95% CI, 0.55-1.21; P = .106; P < .0001 for the interaction). Statin use after diagnosis was not associated with reduced risk of death from any cause or from cancer for patients whose tumors did not contain KRAS mutations (adjusted RR, 0.81; 95% CI, 0.56-1.18; P = .273) or whose tumors did have KRAS mutations (adjusted RR, 0.59; 95% CI 0.35-1.03; P = .062; P = .90 for the interaction).

CONCLUSIONS

In an analysis of 999 patients with a diagnosis of colon cancer, we associated statin with reduced risk of death from any cause or from cancer. The benefit of statin use is greater for patients whose tumors have intact BMP signaling, independent of KRAS mutation status. Randomized controlled trials are required to confirm these results.

Statins intake and risk of liver cancer: A dose-response meta analysis of prospective cohort studies

Previous studies have indicated that statins intake was associated with liver cancer risk, but presented controversial results.Studies in PubMed and EMBASE were searched update to February 2017 to identify and quantify the potential dose-response association between statins intake and liver cancer.Six eligible studies involving a total of 11,8961 participants with 9530 incident cases were included in this meta-analysis. Statistically significant association was observed between increasing statins intake and liver cancer risk reduction (OR = 0.46, 95%CI: 0.24-0.68, P <.001). Furthermore, the summary relative risk of liver cancer for an increase of 50 cumulative defined daily dose per year was 0.86 (95%CI: 0.81-0.90, P <.001). Evidence of a nonlinear dose-response relationship between statins intake and liver cancer risk was found (P for nonlinearity <.01). Subgroups analysis indicated that statins intake was associated with a significantly risk of liver cancer risk reduction in Asia (OR = 0.44, 95%CI: 0.11-0.77, P <.001) and Caucasian (OR = 0.49, 95%CI: 0.36-0.61, P <.001). Subgroup meta-analyses in study design, study quality, number of participants, and number of cases showed consistency with the primary findings.Additional statins intake is associated with liver cancer risk reduction.

RKTG overexpression inhibits proliferation and induces apoptosis of human leukemia cells via suppression of the ERK and PI3K/AKT signaling pathways

Raf kinase trapping to Golgi (RKTG) is reported to be a tumor suppressor in a number of solid tumors due to its negative modulation of the Ras/Raf/mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (ERK) pathways. However, the role of RKTG in the progression of leukemia remains unknown. In the present study, a human leukemia U937 cell line overexpressing RKTG was established, and the effect of RKTG on proliferation, cell cycle and apoptosis of human leukemia cells was analyzed. The results of the present study demonstrated that exogenous overexpression of RKTG significantly inhibited cell proliferation, which was accompanied by cell cycle arrest. Apoptosis assay and Hoechst staining demonstrated that the percentage of apoptotic cells in RKTG overexpressing cells was markedly increased. Furthermore, western blotting showed that RKTG overexpression significantly increased the level of cleaved caspase 3, B-cell lymphoma 2 (Bcl2)-associated X apoptosis regulator and reduced the level of Bcl-2. In addition, the activation of ERK and phosphoinositide 3-kinase (PI3K)/AKT serine/threonine kinase 1 signaling pathways in human leukemia cells was also suppressed by RKTG overexpression. In conclusion, the present study demonstrated the tumor-suppressive effect of RKTG on human leukemia cells, which seem to be partially dependent on the suppression of ERK and PI3K/AKT signaling. Overexpression of RKTG may be a potential therapeutic target for the treatment of leukemia.

Evidence for Feedback Regulation Following Cholesterol Lowering Therapy in a Prostate Cancer Xenograft Model

BACKGROUND

Epidemiologic data suggest cholesterol-lowering drugs may prevent the progression of prostate cancer, but not the incidence of the disease. However, the association of combination therapy in cholesterol reduction on prostate or any cancer is unclear. In this study, we compared the effects of the cholesterol lowering drugs simvastatin and ezetimibe alone or in combination on the growth of LAPC-4 prostate cancer in vivo xenografts.

METHODS

Proliferation assays were conducted by MTS solution and assessed by Student's t-test. 90 male nude mice were placed on a high-cholesterol Western-diet for 7 days then injected subcutaneously with 1 × 10⁵ LAPC-4 cells. Two weeks post-injection, mice were randomized to control, 11 mg/kg/day simvastatin, 30 mg/kg ezetimibe, or the combination and sacrificed 42 days post-randomization. We used a generalized linear model with the predictor variables of treatment, time, and treatment by time (i.e., interaction term) with tumor volume as the outcome variable. Total serum and tumor cholesterol were measured. Tumoral RNA was extracted and cDNA synthesized from 1 ug of total RNA for quantitative real-time PCR.

RESULTS

Simvastatin directly reduced in vitro prostate cell proliferation in a dose-dependent, cell line-specific manner, but ezetimibe had no effect. In vivo, low continuous dosing of ezetimibe, delivered by food, or simvastatin, delivered via an osmotic pump had no effect on tumor growth compared to control mice. In contrast, dual treatment of simvastatin and ezetimibe accelerated tumor growth. Ezetimibe significantly lowered serum cholesterol by 15%, while simvastatin had no effect. Ezetimibe treatment resulted in higher tumor cholesterol. A sixfold induction of low density lipoprotein receptor mRNA was observed in ezetimibe and the combination with simvastatin versus control tumors.

CONCLUSIONS

Systemic cholesterol lowering by ezetimibe did not slow tumor growth, nor did the cholesterol independent effects of simvastatin and the combined treatment increased tumor growth. Despite lower serum cholesterol, tumors from ezetimibe treated mice had higher levels of cholesterol. This study suggests that induction of low density lipoprotein receptor is a possible mechanism of resistance that prostate tumors use to counteract the therapeutic effects of lowering serum cholesterol. Prostate 77:446-457, 2017. © 2016 Wiley Periodicals, Inc.

Geranylgeranyl diphosphate synthase inhibition induces apoptosis that is dependent upon GGPP depletion, ERK phosphorylation and caspase activation

Bisphosphonates are diphosphate analogs that inhibit the intermediate enzymes of the mevalonate pathway. Here, we compared the effects of a farnesyl diphosphate synthase inhibitor, zoledronate, and a geranylgeranyl diphosphate synthase (GGDPS) inhibitor, digeranyl bisphosphonate (DGBP), on lymphocytic leukemia cell proliferation and apoptosis. Both zoledronate and DGBP inhibited proliferation with DGBP doing so more potently. DGBP was markedly less toxic than zoledronate toward the viability of healthy human peripheral blood mononuclear cells. Addition of GGPP, but not farnesyl diphosphate (FPP), prevented the anti-proliferative effects of DGBP. Both GGPP and FPP partially rescued the effects of zoledronate. Co-treatment with DGBP and zoledronate was antagonistic. To further assess the effects of the bisphosphonates, we analyzed annexin V and propidium iodide staining via flow cytometry and found that DGBP induced apoptosis more potently than zoledronate. Western blots show that DGBP treatment altered expression and membrane affinity of some but not all geranylgeranylated small GTPases, activated caspases and increased ERK phosphorylation. Importantly, the anti-proliferative effects of DGBP were blocked by treatment with a caspase inhibitor and by treatment with a MEK inhibitor. Together, our findings indicate that DGBP is a more potent and selective compound than zoledronate in inducing apoptosis mediated through pathways that include caspases and MEK/ERK. These findings support the further development of GGDPS inhibitors as anticancer therapeutics.

Sanguinarine inhibits growth and invasion of gastric cancer cells via regulation of the DUSP4/ERK pathway

Sanguinarine, a bioactive benzophenanthridine alkaloid extracted from plants of the Papaveraceae family, has shown antitumour effects in multiple cancer cells. But the therapeutic effects and regulatory mechanisms of sanguinatine in gastric cancer (GC) remain elusive. This study was aimed to investigate the correlation of dual‐specificity phosphatase 4 (DUSP4) expression with clinicopathologic features and overall survival in patients with GC and explore the effects of sanguinarine on tumour growth and invasion in GC cells (SGC‐7901 and HGC‐27) and underlying molecular mechanisms. Immunohistochemical analysis showed that decreased DUSP4 expression was associated with the sex, tumour size, depth of invasion and distant metastasis in patients with GC. Functional experiments including CCK‐8, Transwell and flow cytometry analysis indicated that sanguinarine or DUSP4 overexpression inhibited GC cell viability and invasive potential, and induced cell apoptosis and cycle arrest in S phase, but DUSP4 knockdown attenuated the antitumour activity of sanguinarine. Further observation demonstrated that sanguinarine up‐regulated the expression of DUSP4 and Bcl‐2‐associated X protein (Bax), but down‐regulated phosphorylated extracellular signal‐regulated kinase (p‐ERK), proliferating cell nuclear antigen (PCNA), matrix metalloproteinase 2 (MMP‐2) and B‐cell lymphoma 2 (Bcl‐2) expression. Taken together, our findings indicate that sanguinarine inhibits growth and invasion of GC cells through regulation of the DUSP4/ERK pathway, suggesting that sanguinarine may have potential for use in GC treatment.

4-cholesten-3-one suppresses lung adenocarcinoma metastasis by regulating translocation of HMGB1, HIF1α and Caveolin-1

Metastasis is a great challenge in lung adenocarcinoma (ADC) therapy. Cholesterol has been implicated in ADC metastasis. 4-cholesten-3-one, as cholesterol metabolite and analog, can substitute membrane cholesterol and increase membrane fluidity. In this study, we explored the possibility that 4-cholesten-3-one inhibited ADC metastasis. Low-dose 4-cholesten-3-one significantly restrained ADC cells migration and invasion with little effects on cells viabilities. Further investigation showed that 4-cholesten-3-one promoted ROS generation, which transiently activated AMPKα1, increased HIF1α expression, reduced Bcl-2 expression and caused autophagy. AMPKα1 knockdown partly suppressed 4-cholesten-3-one-induced autophagy but, neither prevented 4-cholesten-3-one-induced upregulation of HIF1α or downregulation of Bcl-2. 4-cholesten-3-one-induced autophagy facilitated the release of HMGB1 from nuclei to cytoplasm, blocking nuclear translocation of HIF1α and activation of MMP2 and MMP9. Also, 4-cholesten-3-one induced time-dependent phosphorylation of caveolin-1, Akt and NF-κB. With increasing treatment time, 4-cholesten-3-one accelerated caveolin-1 internalization, but reduced the phosphorylation of Akt and NF-κB, and inhibited the expression of snail and twist. These data suggested that 4-cholesten-3-one could be a potential candidate for anti-metastasis of lung adenocarcinoma.

T-LAK cell-originated protein kinase presents a novel therapeutic target in FLT3-ITD mutated acute myeloid leukemia

Gain-of-function mutations of FLT3 (FLT3-ITD), comprises up to 30% of normal karyotype acute myeloid leukemia (AML) and is associated with an adverse prognosis. Current FLT3 kinase inhibitors have been tested extensively, but have not yet resulted in a survival benefit and novel therapies are awaited. Here we show that T-LAK cell-originated protein kinase (TOPK), a mitotic kinase highly expressed in and correlated with more aggressive phenotype in several types of cancer, is expressed in AML but not in normal CD34+ cells and that TOPK knockdown decreased cell viability and induced apoptosis. Treatment of AML cells with TOPK inhibitor (OTS514) resulted in a dose-dependent decrease in cell viability with lower IC₅₀ in FLT3-mutated cells, including blasts obtained from patients relapsed after FLT3-inhibitor treatment. Using a MV4-11-engrafted mouse model, we found that mice treated with 7.5 mg/kg IV daily for 3 weeks survived significantly longer than vehicle treated mice (median survival 46 vs 29 days, P < 0.001). Importantly, we identified TOPK as a FLT3-ITD and CEBPA regulated kinase, and that modulating TOPK expression or activity resulted in significant decrease of FLT3 expression and CEBPA phosphorylation. Thus, targeting TOPK in FLT3-ITD AML represents a novel therapeutic approach for this adverse risk subset of AML.