SOX7 blocks vasculogenic mimicry in oral squamous cell carcinoma

Lupeol and Paclitaxel cooperate in hindering hypoxia induced vasculogenic mimicry via suppression of HIF-1α-EphA2-Laminin-5γ2 network in human oral cancer

Vasculogenic mimicry (VM), defined as an endothelial cell independent alternative mechanism of blood and nutrient supply by dysregulated tumor cells, is associated with poor prognosis in oral squamous cell carcinoma (OSCC). Here we aim to investigate the underlying molecular mechanism of the synergistic effect of phytochemical Lupeol and standard microtubule inhibitor Paclitaxel in reversing the hypoxia induced VM formation in OSCC. The results demonstrated that the hypoxia induced upregulation of HIF-1α led to augmentation of signaling cascade associated with extracellular matrix remodeling and EMT phenotypes that are mechanistically linked to VM. Induction of HIF-1α altered the expression of EMT/CSC markers (E-Cadherin, Vimentin, Snail, Twist and CD133) and enhanced the ability of cell migration/invasion and spheroid formation. Subsequently, the targeted knockdown of HIF-1α by siRNA led to the perturbation of matrigel mediated tube formation as well as of Laminin-5γ2 expression with the down-regulation of VE-Cadherin, total and phosphorylated (S-897) EphA2, pERK1/2 and MMP2. We also observed that Lupeol in association with Paclitaxel resulted to apoptosis and the disruption of VM associated phenotypes in vitro. We further validated the impact of this novel interventional approach in a patient derived tumor explant culture model of oral malignancy. The ex vivo tumor model mimicked the in vitro anti-VM potential of Lupeol-Paclitaxel combination through down-regulating HIF-1α/EphA2/Laminin-5γ2 cascade. Together, our findings elucidated mechanistic underpinning of hypoxia induced Laminin-5γ2 driven VM formation highlighting that Lupeol-Paclitaxel combination may serve as novel therapeutic intervention in perturbation of VM in human OSCC.

miR-146a Inhibited Pancreatic Cancer Cell Proliferation by Targeting SOX7

MicroRNAs (miRNAs) act as a kind of small and noncoding RNA, which have been implicated in the regulation of various pathobiological processes in cancer, including progression in pancreatic cancer and in other human cancers. Previous reports demonstrate that pancreatic cancer has been reported as one of the leading causes of cancer-related death, and some factors including oncogenic genes and environments are involved in tumorigenesis. In our study, we found microRNA-146a (miR-146a) was evidently downregulated in pancreatic cancer tissues and cells. Overexpression of miR-146a obviously reduced cell proliferation and tumorigenesis in vitro, as determined by MTT analysis, colony formation analysis, EdU analysis, and cell cycle experiments. Here, we found tumor suppressor sex-determining region Y-box 7 (SOX7) was the direct target of miR-146a. Overexpression of miR-146a decidedly inhibited SOX7 expression, which promotes cell proliferation and tumorigenesis. Knockdown of miR-146a increased SOX7 expression. Depression of miR-146a and SOX7 promoted cell proliferation and tumorigenesis in vitro, confirming miR-146a regulated pancreatic cancer cell proliferation by inhibiting SOX7. In summary, we found miR-146a reduced the cell proliferation of pancreatic cancer through targeting SOX7. In the present study, we demonstrated the function of miR-146a in pancreatic cancer and might provide a new target in the treatment of pancreatic cancer.