Prediagnosis Use of Statins Associates With Increased Survival Times of Patients With Pancreatic Cancer

The effects of statins in patients with advanced-stage cancers - a systematic review and meta-analysis

Background

Statin therapy has been shown to reduce mortality in a wide range of cancer types and overall stages. Still, there is uncertainty about its efficacy in increasing survival among advanced cancer patients.

Methods

We conducted a meta-analysis with data from all studies that compared the hazard ratio of overall survival, cancer-specific survival, and progression-free survival in patients with advanced-stage cancer who receive statin therapy. Studies were selected from the PubMed, Embase, and Web of Science databases from their inception to December 31, 2022. Cancer types are limited to those rarely screened during the annual examination and more likely to develop into advanced stages, such as lung, pancreatic and ovarian cancers. This resulted in 27 studies eligible for meta-analysis.

Results

Statin therapy was associated with a 26% decreased risk of overall survival (HR, 0.74; 95% CI, 0.67, 0.81), 26% decreased risk of cancer-specific survival (HR, 0.74; 95% CI, 0.61-0.88), and 24% decreased risk of progression-free survival (HR, 0.76; 95% CI, 0.65-0.87) for advanced-stage cancer patients. The associations were not attenuated or reinforced by study design, study regions, cancer types, or other medical care. Concomitant use of other anticancer medications did not result in confounding effects.

Conclusions

Statin therapy produces significant benefits on overall survival and cancer-specific survival. Although the benefits might be lower than the approved immunotherapy medications, its cost-effectiveness could lead to dramatic health consequences. Concomitant use of statin drugs as cancer treatments is highly recommended in future clinical trials.

A Systematic Review and Meta-analysis on the Role of Statins in the Prevention of Mortality Following Pancreatic Cancer

BACKGROUND

Pancreatic cancer (PC) is a type of cancer with a high incidence and case-fatality rate.

OBJECTIVE

This study aimed to evaluate the role of statins in preventing mortality following PC based on scientific evidence with systematic review and meta-analysis method.

METHODS

This meta-analysis considered studies published from 1980 till the end of 2022 in ISI Web of Science, Scopus, PubMed, Cochrane, Science Direct, Google Scholar, and Embase databases. Funnel diagrams and Begg's and Egger's tests were used to assess the publication bias.

RESULTS

In general, this meta-analysis has included 19 studies (13 cohort studies, 4 case-control, and 2 randomized clinical trials (RCTs)) and a total of 100,888 patients with PC. The risk of mortality of PC in statin users in total was 0.86 (95% CI: 0.80 - 0.92, P-value <0.001); in the case-control studies, it was equal to 0.53 (0.34-0.83); in the cohort studies, it was equal to 0.87 (0.82-0.92, P-value <0.001); in RCTs, it was equal to 1.19 (0.99-1.42, P-value <0.001); in studies with good quality score category, it was equal to 0.92 (0.86-0.99, P-value <0.001), and in articles of the moderate quality score category, it was equal to 0.73 (0.64-0.84, P-value <0.001). The results of statistical tests indicated the existence of publication bias (Begg's test (P-value = 0.002) and Egger's test (P-value = 0.004)).

CONCLUSION

Statins reduce the risk of mortality in patients with PC. However, no significant relation has been observed in RCTs. Therefore, it is necessary to be cautious in interpreting the results.

Statins Inhibit Inflammatory Cytokine Production by Macrophages and Acinar-to-Ductal Metaplasia of Pancreatic Cells

BACKGROUND AND AIMS:

Animal data show that the presence of an oncogenic Kras mutation in pancreatic acinar cells leads to acinar-to-ductal metaplasia (ADM), pancreatic intraepithelial neoplasia (PanIN), and pancreatic ductal adenocarcinoma (PDAC). Inflammatory macrophages play an important role in the formation of ADMs and transition to PanINs. Epidemiologically, statins are associated with a reduced risk of PDAC. We investigated whether statins inhibit inflammatory cytokine production in macrophages and whether this leads to reduced ADM formation.

METHODS:

The efficacy of statins on inflammatory cytokine production in 2 macrophage cell lines was measured by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. The effect of macrophage-conditioned medium on ADM in primary pancreatic acinar cells was investigated. Mouse pancreatic tissue samples were analyzed for macrophage numbers, cytokine levels, and neoplastic/dysplastic area.

RESULTS:

Lipophilic statins prevented inflammatory cytokine production in Raw264.7 and J774A.1 cells stimulated by lipopolysaccharide. The inhibitory effect of statins was mediated by inhibition of mevalonate and geranylgeranyl pyrophosphate synthesis and disruption of the actin cytoskeleton but not by a reduction in intracellular cholesterol. Treatment of macrophages with lipophilic statins also blocked ADM formation of primary pancreatic acinar cells. Furthermore, oral administration of simvastatin was associated with a reduction in the number of intrapancreatic macrophages, decreased inflammatory cytokine levels in the pancreas, and attenuated ADM/PanIN formation in mice.

CONCLUSION:

Our data support the hypothesis that statins oppose early PDAC development by their effects on macrophages and ADM formation. The inhibitory actions of statins on macrophages may collaborate with direct inhibitory effects on transformed pancreatic epithelial cells, which cumulatively may reduce early PDAC development and progression.

Use of non-cancer drugs and survival among patients with pancreatic adenocarcinoma: a nationwide registry-based study in Norway

BACKGROUND

The prognosis of pancreatic cancer is poor and new treatment strategies are urgently needed. To identify non-cancer drugs that could be re-purposed for cancer, we investigated the association between the use of selected drugs and cancer-specific mortality in a nationwide cohort of pancreatic cancer patients.

MATERIAL AND METHODS

The study is based on linkage between the Cancer Registry of Norway and the Norwegian Prescription Database, comprising 2614 pancreatic cancer patients diagnosed between 2007 and 2014. We evaluated the association between use at diagnosis of a pre-defined list of non-cancer drugs, including metformin, antihypertensives, and statins, and pancreatic cancer-specific mortality, using Cox regression. Patients were defined as users of a particular drug if it was prescribed before diagnosis, and the prescription covered the date of diagnosis.

RESULTS

In total, 2096 (80.2%) patients died from pancreatic cancer; median survival was 6 months. Statin users (n = 621) had lower mortality (hazard ratio (HR): 0.86; 95% confidence interval (CI) 0.76-0.97) compared to non-users (n = 1993). This association was more pronounced (P-heterogeneity 0.062) in users of hydrophilic (n = 37, HR: 0.61; 95% CI 0.42-0.90) than lipophilic (n = 587, HR: 0.87; 95% CI 0.78-0.98) statins. An indication for lower mortality (HR: 0.85; 95% CI 0.69-1.05) was observed in users of non-selective beta-blockers (n = 113) compared to non-users (n = 2501). Notably, when compared to users of other antihypertensives (n = 643), users of non-selective beta-blockers (n = 40) had lower mortality (HR 0.67; 95% CI 0.47-0.96). The use of other drugs, including selective beta-blockers and metformin, was not associated with mortality.

CONCLUSION

The findings suggest an association between the use of statins and non-selective beta-blockers and reduced pancreatic cancer mortality, and add to the literature supporting the design of randomised clinical trials to evaluate those drugs in the management of pancreatic cancer.

Osimertinib-resistant NSCLC cells activate ERBB2 and YAP/TAZ and are killed by neratinib

We performed additional mechanistic analyses to redefine neratinib biology and determined the mechanisms by which the multi-kinase inhibitor neratinib interacted with the thymidylate synthase inhibitor pemetrexed to kill NSCLC cells expressing either mutant KRAS (G12S; Q61H; G12A; G12C) or mutant NRAS (Q61K) or mutant ERBB1 (L858R; L858R T790M; exon 19 deletion). Neratinib rapidly reduced KRASG12V and RAC1G12V nanoclustering which was followed by KRASG12V, but not RAC1G12V, being extensively mislocalized away from the plasma membrane. This correlated with reduced levels of, and reorganized membrane localization of phosphatidylserine and cholesterol. Reduced nanoclustering was not associated with inactivation of ERBB1, Merlin or Ezrin. The drug combination killed cells expressing mutant KRAS, NRAS or mutant ERBB1 proteins. Afatinib or osimertinib resistant cells were killed with a similar efficacy to non-resistant cells. Compared to osimertinib-resistant cells, sensitive cells had less ERBB2 Y1248 phosphorylation. In osimertinib resistant H1975 cells, the drug combination was less capable of inactivating AKT, mTOR, STAT3, STAT5, ERK1/2 whereas it gained the ability to inactivate ERBB3. In resistant H1650 cells, the drug combination was less capable of inactivating JAK2 and STAT5. Sensitive cells exhibited elevated basal phosphorylation of YAP and TAZ. In resistant cells, portions of YAP and TAZ were localized in the nucleus. [Neratinib + pemetrexed] increased phosphorylation of YAP and TAZ, caused their nuclear exit, and enhanced ERBB2 degradation. Thus, neratinib targets an unidentified protein whose functional inhibition directly results in RAS inactivation and tumor cell killing. Our data prove that, albeit indirectly, oncogenic RAS proteins are druggable by neratinib.

Biological Significance of YAP/TAZ in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal types of cancer. Despite major advances in defining the molecular mutations driving PDAC, this disease remains universally lethal with an overall 5-year survival rate of only about 7–8%. Genetic alterations in PDAC are exemplified by four critical genes (KRAS, TP53, CDKN2A, and SMAD4) that are frequently mutated. Among these, KRAS mutation ranges from 88% to 100% in several studies. Hippo signaling is an evolutionarily conserved network that plays a key role in normal organ development and tissue regeneration. Its core consists of the serine/threonine kinases mammalian sterile 20-like kinase 1 and 2 (MST1/2) and large tumor suppressor 1 and 2. Interestingly, pancreas-specific MST1/2 double knockout mice have been reported to display a decreased pancreas mass. Many of the genes involved in the Hippo signaling pathway are recognized as tumor suppressors, while the Hippo transducers Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) are identified as oncogenes. By dephosphorylation, YAP and TAZ accumulate in the nucleus and interact with transcription factors such as TEA domain transcription factor-1, 2, 3, and 4. Dysregulation of Hippo signaling and activation of YAP/TAZ have been recognized in a variety of human solid cancers, including PDAC. Recent studies have elucidated that YAP/TAZ play a crucial role in the induction of acinar-to-ductal metaplasia, an initial step in the progression to PDAC, in genetically engineered mouse models. YAP and TAZ also play a key role in the development of PDAC by both KRAS-dependent and KRAS-independent bypass mechanisms. YAP/TAZ have become extensively studied in PDAC and their biological importance during the development and progression of PDAC has been uncovered. In this review, we summarize the biological significance of a dysregulated Hippo signaling pathway or activated YAP/TAZ in PDAC and propose a role for YAP/TAZ as a therapeutic target.

Anti-tumor effect of statin on pancreatic adenocarcinoma: From concept to precision medicine

A statin is a cholesterol-lowering agent, which inhibits HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase and subsequently reduces the cholesterol precursor, and was first used commercially in 1987. The concept of cholesterol restriction leading to cancer cell dysfunction was proposed in 1992. The interruption of different signaling pathways has been proved in preclinical experiments to elucidate the anti-tumor mechanism of statins in pancreatic adenocarcinoma. Observational studies have shown that the clinical use of statins is beneficial in patients with pancreatic adenocarcinoma, including a chemoprevention effect, post-surgical resection follow-up and therapeutic prognosis of advanced cancer stage. Arrest of the cancer cell cycle by the combined use of gemcitabine and statin was observed in a cell line study. The effect of microbiota on the tumor microenvironment of pancreatic adenocarcinoma is a new therapeutic approach as statins can modulate the gut microbiota. Hence, further randomized trials of statins in pancreatic adenocarcinoma treatment will be warranted with application of precision medicine from microbiota-derived, cell cycle-based and signaling pathway-targeted research.

Burden of Pancreatic Cancer: From Epidemiology to Practice

Pancreatic cancer is the seventh leading cause of cancer-related deaths worldwide with 432,242 related deaths in 2018. Unlike other cancers, the incidence of pancreatic cancer continues to increase, with little improvement in survival rates. We review the epidemiologic features of pancreatic cancer, covering surveillance and early detection in high-risk persons. We summarize data on worldwide incidence and mortality and analyze the 1975-2016 data from 9 registries of the National Cancer Institute's Surveillance, Epidemiology, and End Results study, on the overall burden of pancreatic cancer as well as age-, sex-, and race-specific incidence, survival rates and trends. It is important to increase our knowledge of the worldwide and regional epidemiologic features of and risk factors for pancreatic cancer, to identify new approaches for prevention, surveillance, and treatment.

Regular Statin Use and Incidence of Postendoscopic Retrograde Cholangiopancreatography Pancreatitis

GOALS AND BACKGROUND

Endoscopic retrograde cholangiopancreatography is widely utilized to diagnose and treat various pancreaticobiliary diseases, but postendoscopic retrograde cholangiopancreatography pancreatitis (PEP) can be a fatal adverse event. Evidence suggests that statins may exhibit suppressive effects on inflammation in the pancreas. We carried out an observational cohort study to examine the protective effect of statins on PEP.

STUDY

We retrospectively identified consecutive patients who underwent endoscopic retrograde cholangiopancreatography at a tertiary care center in Japan between January 2010 and January 2019. The incidences of PEP were compared between regular and nonregular statin users. Using the multivariable logistic regression model, we examined the association of regular statin use with the incidence of PEP controlling for potential risk factors for PEP.

RESULTS

We included 2664 patients (328 regular statin users and 2336 nonregular users). The incidence of PEP did not differ by statin use status (P=0.52): 8.8% in regular statin users and 7.9% in nonregular users. The multivariable-adjusted odds ratio for PEP comparing regular statin use with nonregular use was 1.08 (95% confidence interval, 0.67-1.72; P=0.76). When we examined specific statin types (hydrophilic and lipophilic statins), we consistently observed the null association: 6.8% of 132 hydrophilic statin users and 10% of 196 lipophilic statin users (P=0.74 and 0.27, respectively, compared with nonregular users).

CONCLUSIONS

Regular statin use was not shown to be protective against PEP. A further investigation is warranted before this medication is tested in prospective randomized trials.

Rosuvastatin inhibit spheroid formation and epithelial-mesenchymal transition (EMT) in prostate cancer PC-3 cell line

There is a growing body of evidence suggesting antitumor activity of statins. In metastasis and invasion of cancer the Epithelial-Mesenchymal Transition (EMT) of cancerous cells is an important process. Our goal was to understand the effect of Rosuvastatin on the EMT process in human prostate cancer cell line PC-3 cells in adherent 2 dimensional (2D) and spheroid 3 dimensional (3D) culture. PC-3 cells were cultured in adherence and/or spheroid culture system. The cells were treated with different concentrations of Rosuvastatin. After 96 h, the cell proliferation, viability, type and number of spheroids, the expression of E-Cadherin, Vimentin and Zeb-1 were analyzed. The results show that Rosuvastatin inhibit cell proliferation without significant cytotoxicity. The spheroid formation and spheroid sizes were inhibited by Rousavastatin in a dose dependent manner. In 2D culture, expression of the E-Cadherin was increased up to 2.0 fold in a dose dependent linear manner (R² = 0.89). Vimentin and Zeb-1 expressions were decreased up to 40 and 20% of untreated control cells expression level respectively, (R² = 0.99 and 0.92). In 3D system, the expression of E-Cadherin did not show a significant change, but Vimentin and Zeb-1 expressions were decreased up to 70 and 40% of untreated control cells expression level respectively in a dose dependent linear manner in comparison to 2D system (R² = 0.36 and 0.90). Our finding indicates that Rousavastatin inhibit cell proliferation and spheroid formation of PC-3 cells. This inhibition accompanies by inhibition of EMT markers. Therefor, this cholesterol lowering agent could probably have potential in the prevention and suppression of cancer in androgen dependent prostate cancer.

The impact of age and comorbidity in advanced or recurrent biliary tract cancer receiving palliative chemotherapy

BACKGROUND AND AIM

Limited data are available on age and comorbidity assessment in patients with biliary tract cancer (BTC). This study aimed to evaluate the association of age and comorbidity burden with clinical outcomes of chemotherapy for BTC.

METHODS

Consecutive 197 BTC patients undergoing first-line chemotherapy between 2007 and 2017 were retrospectively studied. Patients were classified to three groups according to the age-adjusted Charlson comorbidity index (ACCI) excluding the score about BTC and progression-free survival, overall survival (OS), and safety were compared.

RESULTS

Fifty-one patients (26%) were elderly (≥ 75 years), and ACCI was 0-2 in 73 patients (37%), 3-4 in 98 (50%), and ≥ 5 in 26 (13%). ACCI was associated with the administration of first-line combination chemotherapy (89% in 0-2, 80% in 3-4, and 64% in ≥ 5, P < 0.01) and second-line chemotherapy (67% in 0-2, 51% in 3-4, and 35% in ≥ 5, P = 0.01). ACCI was prognostic for OS in addition to performance status, disease status, and CA19-9: The hazard ratios in ACCI of 3-4 and ≥ 5 were 1.39 and 1.79, compared with ACCI of 0-2 (P = 0.04). While overall safety profile did not differ by ACCI, higher ACCI score group developed Grade 3-4 neutropenia more frequently (26% in 0-2, 42% in 3-4, and 46% in ≥ 5, P = 0.04).

CONCLUSION

Age and comorbidity burden did affect OS and safety profile in BTC patients undergoing first-line palliative chemotherapy. ACCI can be a simple and useful tool to evaluate the age and comorbidity burden in these patients.

SOAT1 promotes mevalonate pathway dependency in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis, and new therapies are needed. Altered metabolism is a cancer vulnerability, and several metabolic pathways have been shown to promote PDAC. However, the changes in cholesterol metabolism and their role during PDAC progression remain largely unknown. Here we used organoid and mouse models to determine the drivers of altered cholesterol metabolism in PDAC and the consequences of its disruption on tumor progression. We identified sterol O-acyltransferase 1 (SOAT1) as a key player in sustaining the mevalonate pathway by converting cholesterol to inert cholesterol esters, thereby preventing the negative feedback elicited by unesterified cholesterol. Genetic targeting of Soat1 impairs cell proliferation in vitro and tumor progression in vivo and reveals a mevalonate pathway dependency in p53 mutant PDAC cells that have undergone p53 loss of heterozygosity (LOH). In contrast, pancreatic organoids lacking p53 mutation and p53 LOH are insensitive to SOAT1 loss, indicating a potential therapeutic window for inhibiting SOAT1 in PDAC.

Statin use improves survival in patients with pancreatic ductal adenocarcinoma: A meta-analysis

BACKGROUND

Previous studies on statins' effect on survival of patients with pancreatic ductal adenocarcinoma (PDAC) report conflicting results.

AIMS

To evaluate the association between statin use and PDAC patients' survival.

METHODS

A systematic review and meta-analysis was performed including case-control, cohort studies and randomized controlled trials assessing the association between statin use and survival in PDAC patients. Pooled HRs with 95%CIs were calculated using random effects model; publication bias was assessed through Begg and Mazumdar test and heterogeneity by I2 value.

RESULTS

14 studies with 33,137 PDAC patients, 40% under statins, were included. Statins use was associated to a reduced death risk (HR 0.871; 95%CI: 0.819; 0.927; p = 0.0001) suggesting a protective effect, homogeneous for different geographic areas. This effect was significant in surgically resected patients (HR 0.50; 95%CI: 0.32; 0.76; p = 0.001) but not in those with advanced disease (HR 0.78; 95%CI: 0.59; 1.02; p = 0.07). In studies providing information on statin type, only rosuvastatin resulted associated to a reduced risk of death (HR 0.88; 95%CI: 0.81; 0.96; p = 0.004).

CONCLUSIONS

Statins use is significantly associated with a reduced risk of death in resected PDAC patients. This finding has to be considered with caution due to publication bias and the availability of only few studies for sensitivity analyses.

Prediagnostic Leukocyte Telomere Length and Pancreatic Cancer Survival

BACKGROUND

Leukocyte telomere length has been associated with risk of subsequent pancreatic cancer. Few prospective studies have evaluated the association of prediagnostic leukocyte telomere length with pancreatic cancer survival.

METHODS

We prospectively examined the association of prediagnostic leukocyte telomere length with overall survival (OS) time among 423 participants diagnosed with pancreatic adenocarcinoma between 1984 and 2008 within the Health Professionals Follow-up Study, Nurses' Health Study, Physicians' Health Study, and Women's Health Initiative. We measured prediagnostic leukocyte telomere length in banked blood samples using quantitative PCR. Cox proportional hazards models were used to estimate HRs for OS with adjustment for potential confounders. We also evaluated 10 SNPs at the telomerase reverse transcriptase locus.

RESULTS

Shorter prediagnostic leukocyte telomere length was associated with reduced OS among patients with pancreatic cancer (P trend = 0.04). The multivariable-adjusted HR for OS comparing the lowest with highest quintiles of leukocyte telomere length was 1.39 (95% confidence interval, 1.01-1.93), corresponding to a 3-month difference in median OS time. In an analysis excluding cases with blood collected within 2 years of cancer diagnosis, the association was moderately stronger (HR, 1.55; 95% confidence interval, 1.09-2.21; comparing the lowest with highest quintiles; P trend = 0.01). No prognostic association or effect modification for the prognostic association of prediagnostic leukocyte telomere length was noted in relation to the studied SNPs.

CONCLUSIONS

Prediagnostic leukocyte telomere length was associated with pancreatic cancer survival.

IMPACT

Prediagnostic leukocyte telomere length can be a prognostic biomarker in pancreatic cancer.

Using the Risk Factors of Pancreatic Cancer and Their Interactions in Cancer Screening: A Case-Control Study in Shanghai, China

Background:

The incidence of pancreatic cancer has increased annually, but the risk factors and their interactions are still unknown.

Objective:

The aim of this study was to identify risk factors and the effects of their interactions on pancreatic cancer occurrence among patients in Shanghai, China.

Methods:

We conducted a hospital-based case-control study. The case group consisted of pathologically diagnosed pancreatic cancer patients, and the control group consisted of a healthy population. The Pearson Chi-square test was used to compare the distribution frequencies of data between groups. Multivariate analysis and interaction analysis were conducted to explore possible risk factors and interactions between various variables.

Findings:

Among the 4,821 recruited participants, 1,392 were pancreatic cancer patients and 3,429 were controls. Multivariate logistic analysis suggested that age (>50 years old) (AOR: 16.20 [95% CI 6.78; 38.69]), diabetes (AOR: 5.40 [95% CI 2.70; 10.80]), chronic pancreatitis (AOR: 27.43 [95% CI 2.14; 351.77]), smoking (AOR: 8.86 [95% CI 3.07; 25.58]), and family cancer history (AOR: 2.10 [95% CI 1.09; 8.56]) were the primary risk factors for pancreatic cancer. Interestingly, synergistic interactions between risk factors were found, especially between age and chronic pancreatitis (RERI = 447.93, API = 96.74%, SI = 32.78), age and smoking (RERI = 187.42, API = 94.97%, SI = 21.99), and diabetes and smoking (RERI = 14.39, API = 48.06%, SI = 1.99).

Conclusions:

Age, diabetes, chronic pancreatitis, smoking, and family cancer history have been verified as the primary risk factors for pancreatic cancer in this study. Moreover, the interaction effects between old age, diabetes, chronic pancreatitis, and smoking substantially increase the probability of the development of pancreatic cancer. Cancer screening should be conducted extensively among people with these multiple factors to improve the efficiency.

Neratinib inhibits Hippo/YAP signaling, reduces mutant K-RAS expression, and kills pancreatic and blood cancer cells

Prior studies demonstrated that the irreversible ERBB1/2/4 inhibitor neratinib caused plasma membrane-associated mutant K-RAS to localize in intracellular vesicles, concomitant with its degradation. Herein, we discovered that neratinib interacted with the chemically distinct irreversible ERBB1/2/4 inhibitor afatinib to reduce expression of ERBB1, ERBB2, K-RAS and N-RAS; this was associated with greater-than-additive cell killing of pancreatic tumor cells. Knock down of Beclin1, ATG16L1, Rubicon or cathepsin B significantly lowered the ability of neratinib to reduce ERBB1 and K-RAS expression, and to cause tumor cell death. Knock down of ATM-AMPK suppressed vesicle formation and knock down of cathepsin B-AIF significantly reduced neratinib lethality. PKG phosphorylates K-RAS and HMG CoA reductase inhibitors reduce K-RAS farnesylation both of which remove K-RAS from the plasma membrane, abolishing its activity. Neratinib interacted with the PKG activator sildenafil and the HMG CoA reductase inhibitor atorvastatin to further reduce K-RAS expression, and to further enhance cell killing. Neratinib is also a Ste20 kinase family inhibitor and in carcinoma cells, and hematopoietic cancer cells lacking ERBB1/2/4, it reduced K-RAS expression and the phosphorylation of MST1/3/4/Ezrin by ~ 30%. Neratinib increased LATS1 phosphorylation as well as that of YAP and TAZ also by ~ 30%, caused the majority of YAP to translocate into the cytosol and reduced YAP/TAZ protein levels. Neratinib lethality was enhanced by knock down of YAP. Neratinib, in a Rubicon-dependent fashion, reduced PAK1 phosphorylation and that of its substrate Merlin. Our data demonstrate that neratinib coordinately suppresses both mutant K-RAS and YAP function to kill pancreatic tumor cells.

Lipophilic statins inhibit YAP nuclear localization, co-activator activity and colony formation in pancreatic cancer cells and prevent the initial stages of pancreatic ductal adenocarcinoma in KrasG12D mice

We examined the impact of statins on Yes-associated Protein (YAP) localization, phosphorylation and transcriptional activity in human and mouse pancreatic ductal adenocarcinoma (PDAC) cells. Exposure of sparse cultures of PANC-1 and MiaPaCa-2 cells to cerivastatin or simvastatin induced a striking re-localization of YAP from the nucleus to the cytoplasm and inhibited the expression of the YAP/TEAD-regulated genes Connective Tissue Growth Factor (CTGF) and Cysteine-rich angiogenic inducer 61 (CYR61). Statins also prevented YAP nuclear import and expression of CTGF and CYR61 stimulated by the mitogenic combination of insulin and neurotensin in dense culture of these PDAC cells. Cerivastatin, simvastatin, atorvastatin and fluvastatin also inhibited colony formation by PANC-1 and MiaPaCa-2 cells in a dose-dependent manner. In contrast, the hydrophilic statin pravastatin did not exert any inhibitory effect even at a high concentration (10 μM). Mechanistically, cerivastatin did not alter the phosphorylation of YAP at Ser¹²⁷ in either PANC-1 or MiaPaCa-2 cells incubated without or with neurotensin and insulin but blunted the assembly of actin stress fiber in these cells. We extended these findings with human PDAC cells using primary KC and KPC cells, (expressing KrasG12D or both KrasG12D and mutant p53, respectively) isolated from KC or KPC mice. Using cultures of these murine cells, we show that lipophilic statins induced striking YAP translocation from the nucleus to the cytoplasm, inhibited the expression of Ctgf, Cyr61 and Birc5 and profoundly inhibited colony formation of these cells. Administration of simvastatin to KC mice subjected to diet-induced obesity prevented early pancreatic acini depletion and PanIN formation. Collectively, our results show that lipophilic statins restrain YAP activity and proliferation in pancreatic cancer cell models in vitro and attenuates early lesions leading to PDAC in vivo.

Central role of Yes-associated protein and WW-domain-containing transcriptional co-activator with PDZ-binding motif in pancreatic cancer development

Pancreatic ductal adenocarcinoma (PDAC) remains a deadly disease with no efficacious treatment options. PDAC incidence is projected to increase, which may be caused at least partially by the obesity epidemic. Significantly enhanced efforts to prevent or intercept this cancer are clearly warranted. Oncogenic KRAS mutations are recognized initiating events in PDAC development, however, they are not entirely sufficient for the development of fully invasive PDAC. Additional genetic alterations and/or environmental, nutritional, and metabolic signals, as present in obesity, type-2 diabetes mellitus, and inflammation, are required for full PDAC formation. We hypothesize that oncogenic KRAS increases the intensity and duration of the growth-promoting signaling network. Recent exciting studies from different laboratories indicate that the activity of the transcriptional co-activators Yes-associated protein (YAP) and WW-domain-containing transcriptional co-activator with PDZ-binding motif (TAZ) play a critical role in the promotion and maintenance of PDAC operating as key downstream target of KRAS signaling. While initially thought to be primarily an effector of the tumor-suppressive Hippo pathway, more recent studies revealed that YAP/TAZ subcellular localization and co-transcriptional activity is regulated by multiple upstream signals. Overall, YAP has emerged as a central node of transcriptional convergence in growth-promoting signaling in PDAC cells. Indeed, YAP expression is an independent unfavorable prognostic marker for overall survival of PDAC. In what follows, we will review studies implicating YAP/TAZ in pancreatic cancer development and consider different approaches to target these transcriptional regulators.

Acetyl-CoA Metabolism Supports Multistep Pancreatic Tumorigenesis

Pancreatic ductal adenocarcinoma (PDA) has a poor prognosis, and new strategies for prevention and treatment are urgently needed. We previously reported that histone H4 acetylation is elevated in pancreatic acinar cells harboring Kras mutations prior to the appearance of premalignant lesions. Because acetyl-CoA abundance regulates global histone acetylation, we hypothesized that altered acetyl-CoA metabolism might contribute to metabolic or epigenetic alterations that promote tumorigenesis. We found that acetyl-CoA abundance is elevated in KRAS-mutant acinar cells and that its use in the mevalonate pathway supports acinar-to-ductal metaplasia (ADM). Pancreas-specific loss of the acetyl-CoA-producing enzyme ATP-citrate lyase (ACLY) accordingly suppresses ADM and tumor formation. In PDA cells, growth factors promote AKT-ACLY signaling and histone acetylation, and both cell proliferation and tumor growth can be suppressed by concurrent BET inhibition and statin treatment. Thus, KRAS-driven metabolic alterations promote acinar cell plasticity and tumor development, and targeting acetyl-CoA-dependent processes exerts anticancer effects. SIGNIFICANCE: Pancreatic cancer is among the deadliest of human malignancies. We identify a key role for the metabolic enzyme ACLY, which produces acetyl-CoA, in pancreatic carcinogenesis. The data suggest that acetyl-CoA use for histone acetylation and in the mevalonate pathway facilitates cell plasticity and proliferation, suggesting potential to target these pathways.See related commentary by Halbrook et al., p. 326.This article is highlighted in the In This Issue feature, p. 305.

Statin treatment and outcomes of metastatic pancreatic cancer: a pooled analysis of two phase III studies

BACKGROUND

The current analysis aims to evaluate the impact of statin co-treatment on the survival of patients with metastatic pancreatic cancer.

METHODS

This is a pooled analysis of de-identified patient data from two clinical trials (NCT01124786; NCT00844649). Overall and progression-free survival according to patient subsets (patients who received or who did not receive statins) were assessed through Kaplan-Meier analysis and log-rank test. Univariate and multivariate Cox regression analysis was performed to evaluate different factors potentially affecting overall and progression-free survival. Propensity score matching was performed to address heterogeneity in baseline characteristics of different subgroups of patients.

RESULTS

A total of 797 patients were assessed in the current study; of which 156 patients received statins and 641 did not receive statins. Using Kaplan-Meier survival estimates, patients who received statins seem to have better overall and progression-free survival compared to patients who did not (P = 0.008; P < 0.001, respectively). In multivariate analysis for factors affecting overall survival, the following factors were associated with worse overall survival: worse performance status (P < 0.001), no statin use (P = 0.044) and multiple sites of metastatic disease (P = 0.023); likewise in multivariate analysis for factors affecting progression-free survival, the following factors were associated with worse progression-free survival: worse performance status (P < 0.001), gemcitabine elaidate chemotherapy (P = 0.015) and no statin use (P = 0.048). Following propensity score matching and using Kaplan-Meier estimates, statin use was also associated with better overall and progression-free survival (P = 0.005; P = 0.040, respectively).

CONCLUSION

Statin use seems to be associated with better overall survival among patients with metastatic pancreatic cancer treated with first-line chemotherapy. Prospective studies designed specifically to assess this potential effect of statins are needed.