Metformin and pancreatic cancer: Is there a role?

Mitochondrial Transfer as a Novel Therapeutic Approach in Disease Diagnosis and Treatment

Mitochondrial dysfunction is a hallmark of numerous diseases, including neurodegenerative disorders, metabolic disorders, and cancer. Mitochondrial transfer, the transfer of mitochondria from one cell to another, has recently emerged as a potential therapeutic approach for restoring mitochondrial function in diseased cells. In this review, we summarize the current understanding of mitochondrial transfer, including its mechanisms, potential therapeutic applications, and impact on cell death pathways. We also discuss the future directions and challenges in the field of mitochondrial transfer as a novel therapeutic approach in disease diagnosis and treatment.

Novel Biomarkers for Inflammatory Bowel Disease and Colorectal Cancer: An Interplay between Metabolic Dysregulation and Excessive Inflammation

Persistent inflammation can trigger altered epigenetic, inflammatory, and bioenergetic states. Inflammatory bowel disease (IBD) is an idiopathic disease characterized by chronic inflammation of the gastrointestinal tract, with evidence of subsequent metabolic syndrome disorder. Studies have demonstrated that as many as 42% of patients with ulcerative colitis (UC) who are found to have high-grade dysplasia, either already had colorectal cancer (CRC) or develop it within a short time. The presence of low-grade dysplasia is also predictive of CRC. Many signaling pathways are shared among IBD and CRC, including cell survival, cell proliferation, angiogenesis, and inflammatory signaling pathways. Current IBD therapeutics target a small subset of molecular drivers of IBD, with many focused on the inflammatory aspect of the pathways. Thus, there is a great need to identify biomarkers of both IBD and CRC, that can be predictive of therapeutic efficacy, disease severity, and predisposition to CRC. In this study, we explored the changes in biomarkers specific for inflammatory, metabolic, and proliferative pathways, to help determine the relevance to both IBD and CRC. Our analysis demonstrated, for the first time in IBD, the loss of the tumor suppressor protein Ras associated family protein 1A (RASSF1A), via epigenetic changes, the hyperactivation of the obligate kinase of the NOD2 pathogen recognition receptor (receptor interacting protein kinase 2 [RIPK2]), the loss of activation of the metabolic kinase, AMP activated protein kinase (AMPKα1), and, lastly, the activation of the transcription factor and kinase Yes associated protein (YAP) kinase, that is involved in proliferation of cells. The expression and activation status of these four elements are mirrored in IBD, CRC, and IBD-CRC patients and, importantly, in matched blood and biopsy samples. The latter would suggest that biomarker analysis can be performed non-invasively, to understand IBD and CRC, without the need for invasive and costly endoscopic analysis. This study, for the first time, illustrates the need to understand IBD or CRC beyond an inflammatory perspective and the value of therapeutics directed to reset altered proliferative and metabolic states within the colon. The use of such therapeutics may truly drive patients into remission.

Obesity, diabetes mellitus, and pancreatic carcinogenesis: Correlations, prevention, and diagnostic implications

The prevalence of obesity, diabetes mellitus (DM), and pancreatic cancer (PC) has been consistently increasing in the last two decades worldwide. Sharing various influential risk factors in genetics and environmental inducers in pathogenesis, the close correlations of these three diseases have been demonstrated in plenty of clinical studies using multiple parameters among different populations. On the contrary, most measures aimed to manage and treat obesity and DM effectively reduce the risk and prevent PC occurrence, yet certain drugs can inversely promote pancreatic carcinogenesis instead. Most importantly, an elevation of blood glucose with or without a reduction in body weight, along with other potential tools, may provide valuable clues for detecting PC at an early stage in patients with obesity and DM, favoring a timely intervention and prolonging survival. Herein, the epidemiological and etiological correlations among these three diseases and the supporting clinical evidence of their connections are first summarized to favor a better and more thorough understanding of obesity- and DM-related pancreatic carcinogenesis. After comparing the distinct impacts of different weight-lowering and anti-diabetic treatments on the risk of PC, the possible diagnostic implications of hyperglycemia and weight loss in PC screening are also addressed in detail.

Tumor microenvironment in pancreatic ductal adenocarcinoma: Implications in immunotherapy

Pancreatic ductal adenocarcinoma is one of the most aggressive and lethal cancers. Surgical resection is the only curable treatment option, but it is available for only a small fraction of patients at the time of diagnosis. With current therapeutic regimens, the average 5-year survival rate is less than 10% in pancreatic cancer patients. Immunotherapy has emerged as one of the most promising treatment options for multiple solid tumors of advanced stage. However, its clinical efficacy is suboptimal in most clinical trials on pancreatic cancer. Current studies have suggested that the tumor microenvironment is likely the underlying barrier affecting immunotherapy drug efficacy in pancreatic cancer. In this review, we discuss the role of the tumor microenvironment in pancreatic cancer and the latest advances in immunotherapy on pancreatic cancer.

Diabetes Mellitus and Pancreatic Ductal Adenocarcinoma-Prevalence, Clinicopathological Variables, and Clinical Outcomes

Simple Summary

The aim of this study is to describe the prevalence of diabetes mellitus (DM) among patients with the diagnosis of pancreatic ductal adenocarcinoma (PDAC), analyse the association between the occurrence of DM and clinicopathological factors, and detect variables influencing overall survival. Diabetes mellitus is prevalent among patients with pancreatic cancer. In our study, patients with diabetes mellitus receiving palliative chemotherapy had significantly higher median OS than those without. Among variables influencing survival, TNM stage, nodal involvement, tumour site, levels of CEA and CRP were confirmed.

Abstract

Background: pancreatic ductal adenocarcinoma (PDAC) is the seventh leading cause of cancer-related deaths with increasing incidence and link to the onset of diabetes mellitus (DM). The aim of this study is to describe the prevalence of DM among patients with the diagnosis of PDAC, analyse the association between the occurrence of DM and clinicopathological factors, and detect variables influencing overall survival. Methods: a retrospective analysis of medical records was performed. The patients were divided into non-DM (n = 101) and DM (n = 74) groups. Statistical analysis with the usage of appropriate tests was conducted. Results: Patients in the groups of DM and NODM had significantly longer median OS than the non-DM group. Nodal involvement, tumour location, level of CEA, CRP and CRP/lymphocytes ratio were significantly associated with OS among patients with any type of DM. Neutropenia was less frequently observed in the DM group. Conclusions: DM is prevalent among patients with pancreatic cancer. In our study, patients with DM receiving palliative chemotherapy had significantly higher median OS than those without DM. The increased comprehension of the mechanisms of the relationship between DM and pancreatic cancer needs further research, which might provide avenues for the development of novel preventive and therapeutic strategies.

Resistance to Gemcitabine in Pancreatic Ductal Adenocarcinoma: A Physiopathologic and Pharmacologic Review

Pancreatic ductal adenocarcinoma (PDAC) is a very aggressive tumor with a poor prognosis and inadequate response to treatment. Many factors contribute to this therapeutic failure: lack of symptoms until the tumor reaches an advanced stage, leading to late diagnosis; early lymphatic and hematic spread; advanced age of patients; important development of a pro-tumoral and hyperfibrotic stroma; high genetic and metabolic heterogeneity; poor vascular supply; a highly acidic matrix; extreme hypoxia; and early development of resistance to the available therapeutic options. In most cases, the disease is silent for a long time, andwhen it does become symptomatic, it is too late for ablative surgery; this is one of the major reasons explaining the short survival associated with the disease. Even when surgery is possible, relapsesare frequent, andthe causes of this devastating picture are the low efficacy ofand early resistance to all known chemotherapeutic treatments. Thus, it is imperative to analyze the roots of this resistance in order to improve the benefits of therapy. PDAC chemoresistance is the final product of different, but to some extent, interconnected factors. Surgery, being the most adequate treatment for pancreatic cancer and the only one that in a few selected cases can achieve longer survival, is only possible in less than 20% of patients. Thus, the treatment burden relies on chemotherapy in mostcases. While the FOLFIRINOX scheme has a slightly longer overall survival, it also produces many more adverse eventsso that gemcitabine is still considered the first choice for treatment, especially in combination with other compounds/agents. This review discusses the multiple causes of gemcitabine resistance in PDAC.

The Impact of Epithelial-Mesenchymal Transition and Metformin on Pancreatic Cancer Chemoresistance: A Pathway towards Individualized Therapy

Globally, pancreatic ductal adenocarcinoma remains among the most aggressive forms of neoplastic diseases, having a dismal prognostic outcome. Recent findings elucidated that epithelial-mesenchymal transition (EMT) can play an important role in pancreatic tumorigenic processes, as it contributes to the manifestation of malignant proliferative masses, which impede adequate drug delivery. An organized literature search with PubMed, Scopus, Microsoft Academic and the Cochrane library was performed for articles published in English from 2011 to 2021 to review and summarize the latest updates and knowledge on the current understanding of EMT and its implications for tumorigenesis and chemoresistance. Furthermore, in the present paper, we investigate the recent findings on metformin as a possible neoadjuvant chemotherapy agent, which affects EMT progression and potentially provides superior oncological outcomes for PDAC patients. Our main conclusions indicate that selectively suppressing EMT in pancreatic cancer cells has a promising therapeutic utility by selectively targeting the chemotherapy-resistant sub-population of cancer stem cells, inhibiting tumor growth via EMT pathways and thereby improving remission in PDAC patients. Moreover, given that TGF-β1-driven EMT generates the migration of tumor-initiating cells by directly linking the acquisition of abnormal cellular motility with the maintenance of tumor initiating potency, the chemoprevention of TGF-β1-induced EMT may have promising clinical applications in the therapeutic management of PDAC outcomes.

Liquid Biopsy as a Prognostic and Theranostic Tool for the Management of Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinomas (PDAC) represent one of the deadliest cancers worldwide. Survival is still low due to diagnosis at an advanced stage and resistance to treatment. Herein, we review the main types of liquid biopsy able to help in both prognosis and adaptation of treatments.

The Function of cGAS-STING Pathway in Treatment of Pancreatic Cancer

The activation of stimulator of interferon genes (STING) signalling pathway has been suggested to promote the immune responses against malignancy. STING is activated in response to the detection of cytosolic DNA and can induce type I interferons and link innate immunity with the adaptive immune system. Due to accretive evidence demonstrating that the STING pathway regulates the immune cells of the tumor microenvironment (TME), STING as a cancer biotherapy has attracted considerable attention. Pancreatic cancer, with a highly immunosuppressive TME, remains fatal cancer. STING has been applied to the treatment of pancreatic cancer through distinct strategies. This review reveals the role of STING signalling on pancreatic tumors and other diseases related to the pancreas. We then discuss new advances of STING in either monotherapy or combination methods for pancreatic cancer immunotherapy.

Metformin and arsenic trioxide synergize to trigger Parkin/pink1-dependent mitophagic cell death in human cervical cancer HeLa cells

Mitochondria are involved in various biological processes including intracellular homeostasis, proliferation, senescence, and death, and mitochondrial mitophagy is closely related to the development and regression of malignant tumors. Recent studies confirmed that the hypoglycemic drug metformin (Met) exerted various antitumor effects, protected neural cells, and improved immunity, while arsenic trioxide (ATO) is an effective chemotherapeutic agent for the clinical treatment of leukemia and various solid tumors. However, the possible combined antitumor effects of Met and ATO and their cellular molecular mechanisms are unclear. We investigated the role of Parkin-mediated mitochondrial mitophagy in the anti-tumor mechanism of Met and ATO by studying the effects of Met and/or ATO on the proliferation and apoptosis of cervical cancer HeLa cells. Both Met and ATO effectively inhibited the proliferative activity of HeLa cells and induced apoptosis by activating Bax and inhibiting Bcl-2. Met and ATO treatment alone or in combination stimulated mitophagosome accumulation in HeLa cells, increased the conversion of microtubule-associated protein light chain 3 (LC3)-I to LC3-II, and decreased levels of the mitophagic lysosomal substrate protein P62. The mitochondrial membrane potential of HeLa cells also decreased, accompanied by activation of the mitochondrial translocase TOM system and the Pink1/Parkin signaling pathway. These results suggested that Met and/or ATO could induce mitophagy in HeLa cells via the Pink1/Parkin signaling pathway, leading to mitophagic apoptosis and inhibition of tumor cell proliferation. The combination of Met and ATO thus has enhanced antitumor effects, suggesting that this combination has potential clinical applications for the treatment of cervical cancer and other tumors.

Type 2 Diabetes Mellitus Intersects With Pancreatic Cancer Diagnosis and Development

The relationship between type 2 diabetes mellitus (T2DM) and pancreatic cancer (PC) is complex. Diabetes is a known risk factor for PC, and new-onset diabetes (NOD) could be an early manifestation of PC that may be facilitate the early diagnosis of PC. Metformin offers a clear benefit of inhibiting PC, whereas insulin therapy may increase the risk of PC development. No evidence has shown that novel hypoglycemic drugs help or prevent PC. In this review, the effects of T2DM on PC development are summarized, and novel strategies for the prevention and treatment of T2DM and PC are discussed.

Drug Repurposing Opportunities in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is considered one of the deadliest tumors worldwide. The diagnosis is often possible only in the latter stages of the disease, with patients already presenting an advanced or metastatic tumor. It is also one of the cancers with poorest prognosis, presenting a five-year survival rate of around 5%. Treatment of PDAC is still a major challenge, with cytotoxic chemotherapy remaining the basis of systemic therapy. However, no major advances have been made recently, and therapeutic options are limited and highly toxic. Thus, novel therapeutic options are urgently needed. Drug repurposing is a strategy for the development of novel treatments using approved or investigational drugs outside the scope of the original clinical indication. Since repurposed drugs have already completed several stages of the drug development process, a broad range of data is already available. Thus, when compared with de novo drug development, drug repurposing is time-efficient, inexpensive and has less risk of failure in future clinical trials. Several repurposing candidates have been investigated in the past years for the treatment of PDAC, as single agents or in combination with conventional chemotherapy. This review gives an overview of the main drugs that have been investigated as repurposing candidates, for the potential treatment of PDAC, in preclinical studies and clinical trials.

Therapeutic Status and Available Strategies in Pancreatic Ductal Adenocarcinoma

One of the most severe and devastating cancer is pancreatic cancer. Pancreatic ductal adenocarcinoma (PDAC) is one of the major pancreatic exocrine cancer with a poor prognosis and growing prevalence. It is the most deadly disease, with an overall five-year survival rate of 6% to 10%. According to various reports, it has been demonstrated that pancreatic cancer stem cells (PCSCs) are the main factor responsible for the tumor development, proliferation, resistance to anti-cancer drugs, and recurrence of tumors after surgery. PCSCs have encouraged new therapeutic methods to be explored that can specifically target cancer cells. Furthermore, stem cells, especially mesenchymal stem cells (MSCs), are known as influential anti-cancer agents as they function through anti-inflammatory, paracrine, cytokines, and chemokine's action. The properties of MSCs, such as migration to the site of infection and host immune cell activation by its secretome, seem to control the microenvironment of the pancreatic tumor. MSCs secretome exhibits similar therapeutic advantages as a conventional cell-based therapy. Moreover, the potential for drug delivery could be enhanced by engineered MSCs to increase drug bioactivity and absorption at the tumor site. In this review, we have discussed available therapeutic strategies, treatment hurdles, and the role of different factors such as PCSCs, cysteine, GPCR, PKM2, signaling pathways, immunotherapy, and NK-based therapy in pancreatic cancer.

Identification of an Autophagy-Related Pair Signature for Predicting Prognoses and Immune Activity in Pancreatic Adenocarcinoma

BACKGROUND

Pancreatic adenocarcinoma (PAAD) spreads quickly and has a poor prognosis. Autophagy research on PAAD could reveal new biomarkers and targets for diagnosis and treatment.

METHODS

Autophagy-related genes were translated into autophagy-related gene pairs, and univariate Cox regression was performed to obtain overall survival (OS)-related IRGPs (P<0.001). LASSO Cox regression analyses were performed to construct an autophagy-related gene pair (ARGP) model for predicting OS. The Cancer Genome Atlas (TCGA)-PAAD cohort was set as the training group for model construction. The model predictive value was validated in multiple external datasets. Receiver operating characteristic (ROC) curves were used to evaluate model performance. Tumor microenvironments and immune infiltration were compared between low- and high-risk groups with ESTIMATE and CIBERSORT. Differentially expressed genes (DEGs) between the groups were further analyzed by Gene Ontology biological process (GO-BP) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses and used to identify potential small-molecule compounds in L1000FWD.

RESULTS

Risk scores were calculated as follows: ATG4B|CHMP4C×(-0.31) + CHMP2B|MAP1LC3B×(0.30) + CHMP6|RIPK2 ×(-0.33) + LRSAM1|TRIM5×(-0.26) + MAP1LC3A|PAFAH1B2×(-0.15) + MAP1LC3A|TRIM21×(-0.08) + MET|MFN2×(0.38) + MET|MTDH×(0.47) + RASIP1|TRIM5×(-0.23) + RB1CC1|TPCN1×(0.22). OS was significantly shorter in the high-risk group than the low-risk group in each PAAD cohort. The ESTIMATE analysis showed no difference in stromal scores but a significant difference in immune scores (p=0.0045) and ESTIMATE scores (p=0.014) between the groups. CIBERSORT analysis showed higher naive B cell, Treg cell, CD8 T cell, and plasma cell levels in the low-risk group and higher M1 and M2 macrophage levels in the high-risk group. In addition, the results showed that naive B cells (r=-0.32, p<0.001), Treg cells (r=-0.31, p<0.001), CD8 T cells (r=-0.24, p=0.0092), and plasma cells (r=-0.2, p<0.026) were statistically correlated with the ARGP risk score. The top 3 enriched GO-BPs were signal release, regulation of transsynaptic signaling, and modulation of chemical synaptic transmission, and the top 3 enriched KEGG pathways were the insulin secretion, dopaminergic synapse, and NF-kappa B signaling pathways. Several potential small-molecule compounds targeting ARGs were also identified.

CONCLUSION

Our results demonstrate that the ARGP-based model may be a promising prognostic indicator for identifying drug targets in patients with PAAD.

Metformin use and the Risk of Gastrointestinal Malignancies in Diabetic Populations: A Meta-Analysis

BACKGROUND

Metformin use has been associated with a decreased risk of cancer and improvement in overall cancer survival rates. However, scant data available regarding metformin's role in the risk of Gastrointestinal (GI) malignancies in patients with type II diabetes. Our study aimed to conduct a meta-analysis to evaluate the association of metformin use and GI cancer risk.

METHODS

We conducted electronic search by two independent investigators using the PubMed and Cochrane library databases. Studies were assessed for design and quality, and a meta-analysis was conducted to quantify the effect of metformin on the odds of developing specific GI malignancies. The final papers that met our prespecified inclusion criteria included 4 case-control studies that address metformin's effect on pancreatic cancer, and 4 case-control studies that address metformin's effect on colorectal cancer in patients with type II DM.

RESULTS

Of 2258 articles screened, 8 eligible studies were identified comprising 483,561 participants diagnosed with DM. Our analysis showed that metformin use was not associated with a significant effect on the odds of developing pancreatic cancer (OR .98; 95% CI 0.82-1.17, P=0. 83). Metformin use was associated with significantly lower odds of having Colorectal Cancer (CRC); (OR 0.84; 95% CI 0.81-0.87, p < 0.01). Sufficient data were not available to conduct analyses on the impact of metformin dose and duration.

CONCLUSION

Our findings suggest that metformin could be a useful neoadjuvant agent for CRC cancer and as a possible preventive therapy for other inflammatory conditions related to colorectal pathologies such as adenomatous polyps and inflammatory bowel disease. Further research is warranted to elucidate the role of metformin on the risk of developing pancreatic cancer, given the complex nature of the organ's regulation on insulin production.

Factors predicting survival in patients with locally advanced pancreatic cancer undergoing pancreatectomy with arterial resection

Pancreatectomy with arterial resection is a treatment option in selected patients with locally advanced pancreatic cancer. This study aimed to identify factors predicting cancer-specific survival in this patient population. A single-Institution prospective database was used. Pre-operative prognostic factors were identified and used to develop a prognostic score. Matching with pathologic parameters was used for internal validation. In a patient population with a median Ca 19.9 level of 19.8 U/mL(IQR: 7.1–77), cancer-specific survival was predicted by: metabolic deterioration of diabetes (OR = 0.22, p = 0.0012), platelet count (OR = 1.00; p = 0.0013), serum level of Ca 15.3 (OR = 1.01, p = 0.0018) and Ca 125 (OR = 1.02, p = 0.00000137), neutrophils-to-lymphocytes ratio (OR = 1.16; p = 0.00015), lymphocytes-to-monocytes ratio (OR = 0.88; p = 0.00233), platelets-to-lymphocytes ratio (OR = 0.99; p = 0.00118), and FOLFIRINOX neoadjuvant chemotherapy (OR = 0.57; p = 0.00144). A prognostic score was developed and three risk groups were identified. Harrell’s C-Index was 0.74. Median cancer-specific survival was 16.0 months (IQR: 12.3–28.2) for the high-risk group, 24.7 months (IQR: 17.6–33.4) for the intermediate-risk group, and 39.0 months (IQR: 22.7–NA) for the low-risk group (p = 0.0003). Matching the three risk groups against pathology parameters, N2 rate was 61.9, 42.1, and 23.8% (p = 0.04), median value of lymph-node ratio was 0.07 (IQR: 0.05–0.14), 0.04 (IQR:0.02–0.07), and 0.03 (IQR: 0.01–0.04) (p = 0.008), and mean value of logarithm odds of positive nodes was − 1.07 ± 0.5, − 1.3 ± 0.4, and − 1.4 ± 0.4 (p = 0.03), in the high-risk, intermediate-risk, and low-risk groups, respectively. An online calculator is available at www.survivalcalculator-lapdac-arterialresection.org. The prognostic factors identified in this study predict cancer-specific survival in patients with locally advanced pancreatic cancer and low Ca 19.9 levels undergoing pancreatectomy with arterial resection.

Survival Benefit of Metformin Use for Pancreatic Cancer Patients Who Underwent Pancreatectomy: Results From a Meta-Analysis

Objective: To evaluate the survival benefit of metformin use for pancreatic cancer (PC) patients underwent pancreatectomy.

Methods: Databases including EMBASE, PubMed, the Cochrane Library were searched to identify studies relevant to the outcomes on the survival benefit of metformin use for the PC patients who underwent pancreatectomy until June 30, 2019. STATA 12.0 software was used to performed the meta-analysis.

Results: 12 studies involving 35,346 PC patients were included in this meta-analysis. With a random-model, there are significant differences in overall survival (HR = 0.85, 95% CI: 0.77–0.94, P = 0.002) between PC patients who were treated with metformin underwent pancreatectomy and those who underwent pancreatectomy without metformin use. Subgroup analyses showed Caucasians (HR = 0.903, 95% CI = 0.825–0.940, P = 0.008) and Asian (HR = 0.691, 95% CI = 0.588–0.813, P = 0.001) PC patients have a significantly reduced risk of death for metformin users. Subgroup analyses also showed a survival benefit for PC patients at stage I-II (HR = 0.762, 95% CI = 0.677–0.858, P = 0.0001).

Conclusions: Metformin use is related to a better survival benefit for PC patients who underwent pancreatectomy, which would be a potential drug for the treatment of PC.

Pancreatic ductal adenocarcinoma: Treatment hurdles, tumor microenvironment and immunotherapy

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal diseases, with an average 5-year survival rate of less than 10%. Unfortunately, the majority of patients have unresectable, locally advanced, or metastatic disease at the time of diagnosis. Moreover, traditional treatments such as chemotherapy, surgery, and radiation have not been shown to significantly improve survival. Recently, there has been a swift increase in cancer treatments that incorporate immunotherapy-based strategies to target all the stepwise events required for tumor initiation and progression. The results in melanoma, non-small-cell lung cancer and renal cell carcinoma are very encouraging. Unfortunately, the application of checkpoint inhibitors, including anti-CTLA4, anti-PD-1, and anti-PD-L1 antibodies, in pancreatic cancer has been disappointing. Many studies have revealed that the PDAC microenvironment supports tumor growth, promotes metastasis and consists of a physical barrier to drug delivery. Combination therapies hold great promise for enhancing immune responses to achieve a better therapeutic effect. In this review, we provide an outline of why pancreatic cancer is so lethal and of the treatment hurdles that exist. Particular emphasis is given to the role of the tumor microenvironment, and some of the latest and most promising studies on immunotherapy in PDAC are also presented.

Genetic variants in the liver kinase B1-AMP-activated protein kinase pathway genes and pancreatic cancer risk

The liver kinase B1-AMP-activated protein kinase (LKB1-AMPK) pathway has been identified as a new target for cancer therapy, because it controls the glucose and lipid metabolism in response to alterations in nutrients and intracellular energy levels. In the present study, we aimed to identify genetic variants of the LKB1-AMPK pathway genes and their associations with pancreatic cancer (PanC) risk using 15 418 participants of European ancestry from two previously published PanC genome-wide association studies. We found that six novel tagging single-nucleotide polymorphisms (SNPs) (i.e, MAP2 rs35075084 T > deletion, PRKAG2 rs2727572 C > T and rs34852782 A > deletion, TP53 rs9895829 A > G, and RPTOR rs62068300 G > A and rs3751936 G > C) were significantly associated with an increased PanC risk. The multivariate logistic regression model incorporating the number of unfavorable genotypes (NUGs) with adjustment for age and sex showed that carriers with five to six NUGs had an increased PanC risk (odds ratio = 1.24, 95% confidence interval = 1.16-1.32 and P < 0.0001), compared to those with zero to four NUGs. Subsequent expression quantitative trait loci (eQTL) analysis further revealed that these SNPs were associated with significantly altered mRNA expression levels either in 373 normal lymphoblastoid cell lines (TP53 SNP rs9895829, P < 0.05) or in whole blood cells of 369 normal donors from the genotype-tissue expression project (GTEx) database [RPTOR SNP rs60268947 and rs28434589, both in high linkage disequilibrium (r2  > 0.9) withRPTOR rs62068300, P < 0.001]. Collectively, our findings suggest that these novel SNPs in the LKB1-AMPK pathway genes may modify susceptibility to PanC, possibly by influencing gene expression.

Metformin-induced anticancer activities: recent insights

Metformin is a widely used antidiabetic drug, and there is evidence among diabetic patients that metformin is a chemopreventive agent against multiple cancers. There is also evidence in human studies that metformin is a cancer chemotherapeutic agent, and several clinical trials that use metformin alone or in combination with other drugs are ongoing. In vivo and in vitro cancer cell culture studies demonstrate that metformin induces both AMPK-dependent and AMPK-independent genes/pathways that result in inhibition of cancer cell growth and migration and induction of apoptosis. The effects of metformin in cancer cells resemble the patterns observed after treatment with drugs that downregulate specificity protein 1 (Sp1), Sp3 and Sp4 or by knockdown of Sp1, Sp3 and Sp4 by RNA interference. Studies in pancreatic cancer cells clearly demonstrate that metformin decreases expression of Sp1, Sp3, Sp4 and pro-oncogenic Sp-regulated genes, demonstrating that one of the underlying mechanisms of action of metformin as an anticancer agent involves targeting of Sp transcription factors. These observations are consistent with metformin-mediated effects on genes/pathways in many other tumor types.

Phenformin and metformin inhibit growth and migration of LN229 glioma cells in vitro and in vivo

Background

Malignant glioma is refractory to conventional treatment, highlighting a need to develop novel efficacious therapies. Biguanides, a class of oral antidiabetic drug, have been thought to inhibit proliferation and metastasis in a variety of cancers.

Purpose

The objective of this study was to investigate the affections of biguanides, phenformin (Phen) and metformin (Met), on growth and migration of glioma cells LN229 in vitro and in vivo.

Methods

Glioma cells LN229 were treated with Phen or Met, then cell proliferation and death were evaluated by MTT assay and PI stain, and cell cycle were evaluated using flow cytometric analysis, meantime wound healing assay and transwell migration assay were performed to detect cell migration ability. In addition, LN229 were injected in thigh of nude mice, and the mice were treated with Phen or Met to detect the effect of Phen and Met in vivo.

Results

Phen and Met could significantly inhibit cell growth through inhibiting cell proliferation, promoting cell death and disturbing cell cycle, and these drugs also could inhibit cell colony formation in glioma cells LN229 in vitro. Meanwhile, both Phen and Met could significantly inhibit cell migration of LN229 in vitro, through effecting the expression of E-cadherin and Vimentin. In addition, both Phen and Met inhibited the growth and migration of LN229 in a tumor xenograft model. Furthermore, Phen and Met were associated with the increased level of ROS of cell mitochondrial, and ROS inhibitor NAC could significantly rescue the cell death induced by Phen and Met.

Conclusion

Phen and Met displayed powerful antitumor effects of LN229, and our findings powerfully suggest the possibility of Phen and Met being used as an adjuvant agent in the treatment of glioma patients.

Hematopoietically expressed homeobox gene is associated with type 2 diabetes in KK Cg-Ay/J mice and a Taiwanese Han Chinese population

Diabetes mellitus (DM) is a chronic disease. The KK Cg-A^y/J (KK-A^y) mouse is an animal model to study type 2 diabetes mellitus (T2D) disease. The present study assessed the expression of hematopoietically expressed homeobox (HHEX) protein in liver tissues of different age groups of mice (6, 16 and 42 weeks) by immunohistochemistry (IHC). The results demonstrated a significant decrease in the percentage of HHEX-positive cells in KK-A^y mice as compared with that in KK-α/α control mice. Furthermore, in Taiwan's Han Chinese population, genotypic and allelic frequency distributions of the rs61862780 single-nucleotide polymorphism (SNP) in the HHEX gene were investigated. The results demonstrated that in the rs61862780 SNP of the 3′-untranslated region (UTR) of HHEX, the frequency of the CC genotype was higher in patients (6.0%) than in controls (2.7%), while the TT genotype frequency was about equal. In the same SNP, the frequency of the C allele was higher in patients (21.0%) than in controls (17.3%), while the T allele frequency was about equal. These results may pave the road for exploring the KK-A^y mouse model and the HHEX SNP rs61862780, which was correlated with the susceptibility to T2D in a Chinese population. Based on these findings, an association of HHEX gene expression with pathological features of T2D was indicated.

Synergistic anti-tumor effects of liraglutide with metformin on pancreatic cancer cells

Either metformin or liraglutide has been reported to have anti-tumor effects on pancreatic cancer cells. However, it is not clear whether their combined treatment has additive or synergistic anti-tumor effects on pancreatic cancer cells. In this study, the human pancreatic cancer cell line MiaPaca-2 was incubated with liraglutide and/or metformin. The cell Counting Kit-8 (CCK-8), colony formation, flow cytometry, and wound-healing and transwell migration assays were used to detect cell viability, clonogenic survival, cell cycle and cell migration, respectively. RT-PCR and western blot analyses were used to determine the mRNA and protein levels of related molecules. Results showed that combination treatment with liraglutide (100 nmol/L) and metformin (0.75 mmol/L) significantly decreased cell viability and colony formation, caused cell cycle arrest, upregulated the level of pro-apoptotic proteins Bax and cleaved caspase-3, and inhibited cell migration in the cells, although their single treatment did not exhibit such effects. Combination index value for cell viability indicated a synergistic interaction of liraglutide and metformin. Moreover, the combined treatment with liraglutide and metformin could activate the phosphorylation of AMP-activated protein kinase (AMPK) more potently than their single treatment in the cells. These results suggest that liraglutide in combination with metformin has a synergistic anti-tumor effect on the pancreatic cancer cells, which may be at least partly due to activation of AMPK signaling. Our study provides new insights into the treatment of patients with type 2 diabetes and pancreatic cancer.

Risk and protective factors for the occurrence of sporadic pancreatic endocrine neoplasms

Pancreatic neuroendocrine neoplasms (PNENs) represent 10% of all pancreatic tumors by prevalence. Their incidence has reportedly increased over recent decades in parallel with that of pancreatic adenocarcinoma. PNENs are relatively rare, and of the few institutions that have published potential risk factors, findings have been heterogeneous. Our objective was to investigate the association between potential risk and protective factors for the occurrence of sporadic PNENs across a European population from several institutions. A multinational European case-control study was conducted to examine the association of selected environmental, family and medical exposure factors using a standardized questionnaire in face-to-face interviews. A ratio of 1:3 cases to controls were sex and age matched at each study site. Adjusted univariate and multivariate logistic regression analysis were performed for statistically significant factors. The following results were obtained: In 201 cases and 603 controls, non-recent onset diabetes (OR 2.09, CI 1.27-3.46) was associated with an increased occurrence of PNENs. The prevalence of non-recent onset diabetes was higher both in cases with metastatic disease (TNM stage III-IV) or advanced grade (G3) at the time of diagnosis. The use of metformin in combination with insulin was also associated with a more aggressive phenotype. Drinking coffee was more frequent in cases with localized disease at diagnosis. Our study concluded that non-recent onset diabetes was associated with an increased occurrence of PNENs and the combination of metformin and insulin was consistent with a more aggressive PNEN phenotype. In contrast to previous studies, smoking, alcohol and first-degree family history of cancer were not associated with PNEN occurrence.

THE ENDOCRINOLOGY OF AGING: A KEY TO LONGEVITY "GREAT EXPECTATIONS"

ABBREVIATIONS

AMP = adenosine monophosphate CETP = cholesteryl ester transfer protein FOXO = Forkhead box O GH = growth hormone HDL = high-density lipoprotein IGF-1 = insulin-like growth factor 1 LDL = low-density lipoprotein miRNA = microRNA mTOR = mammalian target of rapamycin SIRT = sirtuin T4 = thyroxine TSH = thyroid-stimulating hormone "The Moving Finger writes; and, having writ, Moves on: nor all thy Piety nor Wit Shall lure it back to cancel half a Line, Nor all thy Tears wash out a Word of it." Omar Khayyam ( 1 ).

Role of VEGF in metformin induced apoptosis of HepG2 cells

AIM

To investigate the molecular mechanism of metformin induced apoptosis of HepG2 cells.

METHODS

HepG2 cells were treated with different concentrations (0-20 mmol/L) of metformin (MET) for 24 h or 10 mmol/L MET for different times (0-48 h), and the effect of MET on cell proliferation was measured by MTT assay. Annexin V-FITC/PI flow cytometry was used to determine the apoptosis rate. RT-PCR was used to analyze the expression of vascular endothelial growth factor (VEGF) in HepG2 cells treated with MET.

RESULTS

MET had an obvious inhibitory effect on HepG2 cell proliferation. After treatment with 0, 5, 10, 15, and 20 mmol/L MET for 24 h, the relative cell viability rates of HepG2 cells were 100%, 80.56% ± 0.72%, 71.06% ± 0.70%, 64.73% ± 0.35%, and 54.73% ± 0.40%, respectively, showing a dose-dependent manner. After treatment with 10 mmol/L MET for 0, 12, 24, 36, and 48 h, the relative cell viability rates of HepG2 cells were 100%, 83.40% ± 0.70%, 69.86% ± 0.45%, 60.40% ± 0.88%, and 50.70% ± 0.45%, respectively, showing a time-dependent manner. Annexin V-FITC/PI flow cytometry revealed that the apoptosis rates of HepG2 cell were increased after treatment with 0, 5, 10, 15, and 20 mmol/L MET for 24 h, and the apoptosis rates were 2.78% ± 0.68%, 9.33% ± 0.22%, 17.13% ± 0.10%, 21.61% ± 0.20%, and 25.26% ± 1.09%, respectively, showing a dose-dependent manner. The apoptosis rates of HepG2 cells were increased after treatment with 10 mmol/L for 0, 12, 24, 36, 48 h, and the apoptosis rates were 2.05% ± 0.04%, 8.10% ± 0.08%, 16.53% ± 0.93%, 20.95% ± 0.16%, and 25.65% ± 0.44%, showing a time-dependent manner. The expression of VEGF decreased after treatment with different concentrations of MET for 24 h or 10 mmol/L MET for different times, showing a dose- and time-dependent manner.

CONCLUSION

MET can inhibit HepG2 cell proliferation via inducing apoptosis, which may involve the expression of VEGF.

Type 2 diabetes mellitus is associated with increased risk of pancreatic cancer: A veteran administration registry study

BACKGROUND

The etiology of pancreatic cancer remains elusive. Several studies have suggested a role for diabetes mellitus, but the magnitude of its contribution remains controversial.

OBJECTIVES

Utilizing a large administrative database, this retrospective cohort study was designed to investigate the relationship between type 2 diabetes mellitus and pancreatic cancer.

PATIENTS AND DESIGN

Using the Veterans Integrated Services Network 16 database, 322,614 subjects were enrolled in the study, including 110,919 with type 2 diabetes mellitus and 211,695 diabetes-free controls matched by gender, year of birth and healthcare facility.

RESULTS

A significantly higher incidence of pancreatic cancer was observed in patients with type 2 diabetes mellitus, with an adjusted hazard ratio (95% confidence interval) of 2.17 (1.70-2.77) for type 2 diabetes mellitus compared to controls (p < 10^-9) after controlling for the matching factors.

CONCLUSION

The association between type 2 diabetes mellitus and pancreatic cancer was statistically significant and may, in part, explain the rising incidence of pancreatic cancer.

Effect of glycemic control on the risk of pancreatic cancer: A nationwide cohort study

Although the relationship between diabetes and pancreatic cancer has been studied, the effects of glycemic control on pancreatic cancer have never been evaluated. This study investigates the relationship between glycemic control and pancreatic cancer.Data from 1 million National Health Insurance beneficiaries were screened. The study cohort consisted of 46,973 diabetic patients and 652,142 nondiabetic subjects. Of the patients with diabetes, 1114 who had been admitted for hyperglycemic crisis episodes were defined as having poorly controlled diabetes. All adult beneficiaries were followed from January 1, 2005 to December 31, 2013, to determine whether pancreatic cancer was diagnosed. The Cox regression model was applied to compare the adjusted hazards for potential confounders.After controlling for age, sex, urbanization level, socioeconomic status, chronic liver disease, hypertension, coronary artery disease, hyperlipidemia, malignancies, smoking, chronic obstructive pulmonary disease, obesity, history of alcohol intoxication, chronic renal insufficiency, biliary tract disease, chronic pancreatitis, Charlson Comorbidity Index score, and high-dimensional propensity score, the adjusted hazard ratio of pancreatic cancer was 2.53 (95% confidence interval 1.96-3.26) in patients with diabetes. In diabetic patients with poor glycemic control, the hazard ratio of pancreatic cancer was significantly higher (hazard ratio 3.61, 95% confidence interval 1.34-9.78).This cohort study reveals a possible relationship between diabetes and pancreatic cancer. Moreover, poorly controlled diabetes may be associated with a higher possibility of pancreatic cancer.