Anti-tumor properties of the cGMP/protein kinase G inhibitor DT3 in pancreatic adenocarcinoma

Brucine Inhibits Proliferation of Pancreatic Ductal Adenocarcinoma through PI3K/AKT Pathway-induced Mitochondrial Apoptosis

INTRODUCTION

The purpose of this research was to settle the role of brucine in pancreatic ductal adenocarcinoma (PDAC) and the mechanisms involved.

METHODS

The findings of this study suggest that brucine exerts inhibitory effects on cell growth, clonogenicity, and invasive potential of Panc02 and Mia Paca-2 cells. These effects may be linked to an increase in apoptotic-prone cell population.

RESULTS

Gene sequencing data suggests that these effects are mediated through the induction of apoptosis. Experimental evidence further supports the notion that brucine reduces mitochondrial membrane potential and upregulates Bax expression while downregulating Bcl-2 expression. These effects are believed to be a result of brucine-mediated suppression of PI3K/Akt activity, which serves as a regulatory factor of mTOR, Bax, and Bcl-2. Suppression of PI3K activity enhances the tumor-suppressing effects of brucine.

CONCLUSION

Overall, these findings suggest that brucine has therapeutic potential as a remedy option for PDAC.

Glycogen synthase kinase-3β: a novel therapeutic target for pancreatic cancer

Introduction: Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer death in the United States with a single-digit 5-year survival rate despite advances in understanding the genetics and biology of the disease. Glycogen synthase kinase-3α (GSK-3α) and GSK-3β are serine/threonine kinases that localize to the cytoplasm, mitochondria and nucleus. Although they are highly homologous within their kinase domains and phosphorylate an overlapping set of target proteins, genetic studies have shown that GSK-3β regulates the activity of several proteins that promote neoplastic transformation. Significantly, GSK-3β is progressively overexpressed during PDAC development where it participates in tumor progression, survival and chemoresistance. Thus, GSK-3β has become an attractive target for treating PDAC.Areas covered: This review summarizes the mechanisms regulating GSK-3β activity, including upstream translational and post-translational regulation, as well as the downstream targets and their functions in PDAC cell growth, metastasis and chemoresistance.Expert opinion: The activity of GSK-3 kinases are considered cell- and context-specific. In PDAC, oncogenic KRas drives the transcriptional expression of the GSK-3β gene, which has been shown to regulate cancer cell proliferation and survival, as well as resistance to chemotherapy. Thus, the combination of GSK-3 inhibitors with chemotherapeutic drugs could be a promising strategy for PDAC.

Easy-to-use strategy for reference gene selection in quantitative real-time PCR experiments

Real-time PCR is an indispensable technique for mRNA expression analysis but conclusions depend on appropriate reference gene selection. However, while reference gene selection has been a topic of publications, this issue is often disregarded when measuring target mRNA expression. Therefore, we (1) evaluated the frequency of appropriate reference gene selection, (2) suggest an easy-to-use tool for least variability reference gene selection, (3) demonstrate application of this tool, and (4) show effects on target gene expression profiles. All 2015 published articles in Naunyn-Schmiedeberg's Archives of Pharmacology were screened for the use of quantitative real-time PCR analysis and selection of reference genes. Target gene expression (Vegfa, Grk2, Sirt4, and Timp3) in H9c2 cells was analyzed following various interventions (hypoxia, hyperglycemia, and/or isoflurane exposure with and without subsequent hypoxia) in relation to putative reference genes (Actb, Gapdh, B2m, Sdha, and Rplp1) using the least variability method vs. an arbitrarily selected but established reference gene. In the vast majority (18 of 21) of papers, no information was provided regarding selection of an appropriate reference gene. In only 1 of 21 papers, a method of appropriate reference gene selection was described and in 2 papers reference gene selection remains unclear. The method of reference gene selection had major impact on interpretation of target gene expression. With hypoxia, for instance, the least variability gene was Rplp1 and target gene expression (Vefga) heavily showed a 2-fold up-regulation (p = 0.022) but no change (p = 0.3) when arbitrarily using Gapdh. Frequency of appropriate reference gene selection in this journal is low, and we propose our strategy for reference gene selection as an easy tool for proper target gene expression.