MicroRNA-21 (miR-21) is up-regulated in many cancers, including colorectal cancer (CRC). Nevertheless, the function of miR-21 in CRC and the mechanism underlying that function is still unclear. After analyzing the expression of miR-21 and Sec23A in CRC cell lines, we transfected the highest miR-21 expressing cell line, SW-480, with a plasmid containing an miR-21 inhibitor and the lowest miR-21 expressing cell line, DLD-1, with a plasmid containing an miR-21 mimic and measured the effects on the expression of Sec23A and on cell proliferation, migration, and invasion. We also evaluated the effect of knocking down Sec23A on miR-21 expression and its effects on cell proliferation, migration, and invasion. Finally, we assessed the effect of miR-21 in a xenograft tumor model in mice. Tumor tissues from these mice were subjected to immunohistochemical staining to detect the expression of Sec23A. Genetic deletion of miR-21 suppressed the proliferation, migration, and invasion of SW-480 cells, while over-expression of miR-21 promoted proliferation, migration, and invasion of DLD-1 cells. Inhibition of miR-21 increased the expression of Sec23A protein in SW-480 cells while over-expression of miR-21 significantly suppressed the expression of Sec23A protein and Sec23A mRNA in DLD-1 cells. Knockdown of Sec23A increased the expression of miR-21 in SW480 and DLD-1 cells and their proliferation (DLD-1 only), migration, and invasion. Over-expression of miR-21 promoted tumor growth in BALB/c nude mice and suppressed tumor expression of Sec23A. These findings provide novel insight into the molecular functions of miR-21 in CRC, which may serve as a potential interesting target.

Podophyllotoxin (PPT), a lignan extracted from the roots and stems of Podophyllum species, exhibits significant enterotoxicity that limits its clinical application. However, its underlying mechanisms remain unclear. This study aimed to elucidate the mechanisms underlying PPT-induced enterotoxicity. Changes in body weight, fecal morphology, toxic phenotypes, and histopathological features were evaluated. 3D reconstruction, 16S rRNA sequencing, targeted short-chain fatty acids (SCFAs) analysis, and inflammatory cytokine assays were performed. The findings demonstrated that PPT induced pathological changes in rats, including weight loss, diarrhea, and colonic damage. PPT administration significantly reduced beneficial bacteria such as Lactobacillus, while increasing harmful bacteria such as Escherichia-Shigella. The predicted pathways of bacterial invasion of epithelial cells and lipopolysaccharide biosynthesis were significantly upregulated. Levels of pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), were also increased. Additionally, the expression of undecaprenyl-diphosphate synthase (UPPS) and SCFAs production was reduced. These findings indicate that PPT may alter gut microbial composition, increase Escherichia-Shigella invasion in the intestinal epithelial cells, promote lipopolysaccharide production, enhance the release of pro-inflammatory cytokines, including TNF-α and IL-6, and inhibit UPPS expression and SCFAs generation, collectively contributing to enterotoxicity. This study provides novel insights into the mechanisms behind PPT-induced enterotoxicity, which is essential for preventing and treating PPT toxicity.

Liver diseases, ranging from acute injury to chronic fibrosis and hepatocellular carcinoma (HCC), represent a major global health challenge with limited therapeutic options. The liver’s inherent regenerative capacity can be disrupted during chronic disease, resulting in poor outcomes. However, this process is complex, as key regulatory molecules can exert opposite effects. A notable example is Amphiregulin (AREG), an epidermal growth factor receptor (EGFR) ligand whose role changes from promoting protective regeneration in acute injury to driving harmful processes in chronic settings. This review explores the dual and dynamic roles of AREG across the spectrum of liver diseases, with a focus on its expression patterns, downstream molecular pathways, and signaling networks that determine its functional transition from regeneration to fibrosis and carcinogenesis. These insights provide new theoretical foundations and potential intervention strategies for targeting the AREG-EGFR axis in liver disease therapeutics.