Dietary hemin promotes colonic preneoplastic lesions and DNA damage but not tumor development in a medium-term model of colon carcinogenesis in rats.

Red and processed meat consumption has been strongly related to increase the risk of colorectal cancer (CRC), although its impact is largely unknown. Hemin, an iron-containing porphyrin, is acknowledged as a putative factor of red and processed meat pro-carcinogenic effects. The aim of this study was to investigate the effects of high dietary hemin on the promotion/progression stages of 1,2-dimethylhydrazine (1,2-DMH)-induced colon carcinogenesis. Twenty-four Wistar male rats were given four subcutaneous 1,2-DMH injections and received either balanced diet or balanced diet supplemented with hemin 0.5 mmol/kg for 23 weeks. Colon specimens were analyzed for aberrant crypt foci (ACF) and tumor development. Dietary hemin significantly increased ACF number and fecal water cytotoxicity/genotoxicity in Caco-2 cells when compared to 1,2-DMH control group. However, tumor incidence, multiplicity and cell proliferation did not differ between 1,2-DMH + hemin and 1,2-DMH control group. Gene expression analysis of 91 target-genes revealed that only three genes (Figf, Pik3r5 and Tgfbr2) were down-regulated in the tumors from hemin-fed rats compared to those from 1,2-DMH control group. Therefore, the findings of this study show that high hemin intake promotes mainly DNA damage and ACF development and but does not change the number nor incidence of colon tumors induced by 1,2-DMH in male rats.

MicroRNA-3191 promotes migration and invasion by downregulating TGFBR2 in colorectal cancer.

Mutations in transforming growth factor beta receptor II (TGFBR2) are detected in up to 30% of overall colorectal cancer (CRC). Dysregulation of some microRNAs participated in the CRC pathogenesis. In this study, we used the gene ontology analyses, the Kyoto Encyclopedia of Genes and Genomes pathway analyses and gene set enrichment analysis to indicate that miR-3191 was involved in the regulation of transforming growth factor beta (TGF-BETA) signal pathway in CRC. These bioinformatics results were supported by data obtained from CRC samples and experiments in vitro. The luciferase reporter assay was used to confirm that miR-3191 modulates TGF-BETA signal pathway by targeting TGFBR2. By transwell migration and invasion assays, we showed that miR-3191 promoted CRC cell migration and invasion by downregulating TGFBR2. And it may serve as a novel therapeutic strategy for treating CRC patients.

SUMO protease SENP1 acts as a ceRNA for TGFBR2 and thus activates TGFBR2/Smad signaling responsible for LPS-induced sepsis.

This study aims to explore the roles and related mechanisms of SUMO protease SENP1 in sepsis. Here, RNA-sequencing assay showed that SENP1 was significantly increased in human umbilical vein endothelial cells (HUVECs) with LPS treatment. Gene set enrichment analysis (GSEA) of RNA-sequencing dataset revealed that a positive enrichment of inflammation signatures was observed in HUVECs with SENP1 3'UTR overexpression. Further functional annotation analysis revealed that SENP1 3'UTR overexpression was positively correlated with TGFBR2 signaling pathway. Mechanistically, TGFBR2 was identified as a ceRNA (competing endogenous RNA) target of SENP1 and the downstream effectors Smad2/3 were also overexpressed in HUVECs with SENP1 3'UTR overexpression. Injection of SENP1 siRNA following LPS treatment attenuated LPS-induced sepsis, evidenced by the downregulation of IL-2 and TNF-α secretion and prolonged the overall survival of septic mice. Consistent results were obtained in vitro. Additionally, TGFBR2 overexpression partially abrogated SENP1 siRNA-mediated inhibition on LPS-induced sepsis. Thus, these results suggest that SENP1 promotes sepsis via activating the TGFBR2 signaling.

SMAD4 and TGFßR2 expression in pancreatic ductal carcinoma.

Pancreatic ductal carcinoma is the most common type of pancreatic cancer, and currently represents the fourth cause of death by cancer, worldwide. Among classical pancreatic markers that ascertain the histopathology, new emerging targets have been proposed for both diagnostic and prognostic purposes. In the present study, utilizing a group of 28 confirmed resected pancreatic ductal carcinomas, we have assessed the immunoexpression and correlation ratios of mothers against decapentaplegic homolog 4 (Drosophila) (SMAD4)∕transforming growth factor beta receptor 2 (TGFßR2), and vimentin∕cluster of differentiation 105 (CD105). SMAD4 showed an overall increase in tumors versus pancreatic control tissue, but a decrease from G1 towards poorly differentiated tumors, while TGFßR2, vimentin and CD105 showed higher expression values in the tumor areas. Vimentin-CD105 colocalization degree decreased in tumor tissues compared to controls, illustrating a desynchronization of these two markers, both of them being negative in the tumor epithelia. Altogether, it is highly plausible that all these key players revolve around the epithelial-to-mesenchymal transition phenomenon, and this itself modulates the clinical outcome of the patient.