Exosomal lncRNA PVT1/VEGFA Axis Promotes Colon Cancer Metastasis and Stemness by Downregulation of Tumor Suppressor miR-152-3p

Figure 5

Target validation for miR-152-3p and its role in suppressing metastasis. (a) Target binding sequences of miR-152-3p in the 3-UTR of PVT1 and VEGFA. These binding sites were predicted using both miRmap and MiRanda software. (b) qPCR analysis of PVT1, EGFR, and VEGFA levels in response to the sequential miR-152-3p mimic and inhibitor transfections (the control group did not add any reagents). A significant decrease in the mRNA levels of PVT1, EGFR, and VEGFA was observed after miR16-5p mimic transfection and subsequent restoration with the addition of the miR-152-3p inhibitor. Both HCT116 and LoVo cells showed a similar trend. (c) Tumorsphere formation assay. The tumorsphere-forming ability was considerably inhibited by the transfection of miR-152-3p in both HCT116 and LoVo cells; partial restoration of the tumorsphere-forming ability was noted when the miR-152-3p inhibitor was added. (d) Invasion assay revealed that an increase in miR-152-3p significantly reduced the invasive ability in both HCT116 and LoVo cells; however, the invasive ability was restored by the addition of the miR-152-3p inhibitor. (e) Western blot analysis. The addition of miR-152-3p mimics suppressed the expression of EGFR, vimentin, and VEGFA in both HCT116 and LoVo cells, and the inhibitor restored their expression. (f) A negative correlation was noted between miR-152-3p and PVT1 levels in colon cancer clinical samples from databases of TCGA [12] (). Control/NC: scramble hsa-miR-152-3p oligonucleotides. ; ; . Scale bar: 100 μm.

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