RGC-32 induces transition of pancreatic cancer to epithelial mesenchyme in vivo

Metformin Inhibits the Progression of Pancreatic Cancer Through Regulating miR-378a-3p/VEGFA/RGC-32 Axis

BACKGROUND

Pancreatic cancer (PC) is a major contributor to global cancer-related mortality. While the inhibitory effect of metformin (Met) on PC has been reported, the underlying mechanism remains elusive.

METHODS

We established BxPC-3 cell models with miR-378a-3p and VEGFA knockdown. The expression of miR-378a-3p, VEGFA, and RGC-32 in PC and normal tissues was analyzed using GEPIA, TCGA databases. Cell proliferation, invasion, migration, and apoptosis were assessed through CCK8, Transwell, wound healing, and flow cytometry.

RESULTS

Significantly lower expression of miR-378a-3p was observed in PC tissues and cells. Knockdown of miR-378a-3p reversed the impact of Met on cell viability in PANC-1 and BxPC3. VEGFA emerged as a potential regulator in PC and a downstream target of miR-378a-3p. The interaction between VEGFA and RGC-32 played a crucial role in PC regulation. Knockdown of VEGFA substantially reversed the impact of miR-378a-3p inhibitor on tumor growth and the epithelial-mesenchymal transition (EMT) process. Moreover, knockdown of VEGFA effectively countered the influence of miR-378a-3p inhibitor on cell viability and the EMT process in BxPC3 cells.

CONCLUSIONS

Met exerted inhibitory effects on PC through the miR-378a-3p/VEGFA/RGC-32 pathway. Strategies targeting the miR-378a-3p/VEGFA/RGC-32 axis represent a novel avenue for the prevention and treatment of PC.

Oncogenic gene RGC-32 is a direct target of miR-26b and facilitates tongue squamous cell carcinoma aggressiveness through EMT and PI3K/AKT signalling

Growing data have recognized the significance of Response Gene to Complement (RGC)-32 in numerous tumour developments. Notwithstanding, the functional role and underlying mechanism of it in tongue squamous cell carcinoma (TSCC) remain enigmatic. Here, to identify the impact of RGC-32 in TSCC, its expression in multiple TSCC cells was measured and loss-of-function experiments in cell lines were performed to illuminate the function of it induced TSCC progression, via si-RNA knockdown, CCK-8, colony formation, wound-healing, transwell, flow cytometry and western blot assays. To clarify potential mechanism, expressions of hallmarks in epithelial-mesenchymal transition (EMT) process and PI3K/AKT signalling were assessed, and the upstream miR regulator of RGC-32 was predicted and verified by applying bioinformatic approaches and dual-luciferase reporter assay, respectively. Finally, the rescue experiments were applied to better elucidate the effect of miR-26b/RGC-32 axis in TSCC behaviours. As a result, RGC-32 was upregulated in TSCC cells and knocking down of it abrogated cell proliferation, trans-migration and invasion, whilst promoted apoptosis in TSCC, which was regulated through repressing EMT and inactivation of PI3K/AKT signalling. Subsequently, miR-26b was predicted and identified as an upstream regulator of RGC-32, and the pro-tumorigenic effect of RGC-32 was reversed by miR-26b overexpression. Collectively, our results demonstrated that RGC-32 facilitated TSCC progression, which was modulated by activations of PI3K/AKT pathway and EMT process, and reduction of its negative regulator of miR-26b. These findings highlight a novel role of miR-26b/RGC-32 axis in TSCC and underlying mechanism, encouraging a potent usage in TSCC treatment. SIGNIFICANCE OF THE STUDY: We first uncovered that Response Gene to Complement-32 played a significantly pro-tumorigenic role in tongue squamous cell carcinoma (TSCC), which was closely regulated by downregulation of miR-26b and activations of epithelial-mesenchymal transition process and PI3K/AKT signalling. These findings contribute to better understand the molecular mechanism in carcinogenesis of TSCC, and shed some light on promising strategy for TSCC therapeutics.