miR-200 Inhibits Lung Adenocarcinoma Cell Invasion and Metastasis by Targeting Flt1/VEGFR1

Abstract

The microRNA-200 (miR-200) family is part of a gene expression signature that predicts poor prognosis in lung cancer patients. In a mouse model of K-ras/p53-mutant lung adenocarcinoma, miR-200 levels are suppressed in metastasis-prone tumor cells, and forced miR-200 expression inhibits tumor growth and metastasis, but the miR-200 target genes that drive lung tumorigenesis have not been fully elucidated. Here, we scanned the genome for putative miR-200 binding sites and found them in the 3′-untranslated region (3′-UTR) of 35 genes that are amplified in human cancer. Mining of a database of resected human lung adenocarcinomas revealed that the levels of one of these genes, Flt1/VEGFR1, correlate inversely with duration of survival. Forced miR-200 expression suppressed Flt1 levels in metastasis-prone lung adenocarcinoma cells derived from K-ras/p53-mutant mice, and negatively regulated the Flt1 3′-UTR in reporter assays. Cancer-associated fibroblasts (CAFs) isolated from murine lung adenocarcinomas secreted abundant VEGF and enhanced tumor cell invasion in coculture studies. CAF-induced tumor cell invasion was abrogated by VEGF neutralization or Flt1 knockdown in tumor cells. Flt1 knockdown decreased the growth and metastasis of tumor cells in syngeneic mice. We conclude that miR-200 suppresses lung tumorigenesis by targeting Flt1.

Regulation of Vascular Endothelial Growth Factor Signaling by miR-200b

“…As stated earlier, miR-200b targets Ets-1 and inhibits angiogenic activity of HMECs (Chan et al, 2011). Another paper reported that miR-200b targets murine Flt-1 (Roybal et al, 2011). Down-regulation of Flt-1 by miR-200b suppressed invasion and metastasis of lung adenocarcinoma cells.…”

Prognostic significance of combining VEGFA, FLT1 and KDR mRNA expression in lung cancer

“…High expression of these three genes has been identified in non-small cell lung cancer xenografts compared with xenografts originating from other sites (5), indicating that these three factors may be significant in lung cancer progression. Indeed, VEGFA (6)(7)(8), FLT1 (9,10) and KDR (11,12) have all been demonstrated to promote lung cancer progression. However, their utility as prognostic markers remains unknown owing to the conflicting findings of previous studies (12,13).…”

Anti‐Metastatic and Anti‐Angiogenic Activities of Core–Shell SiO2@LDH Loaded with Etoposide in Non‐Small Cell Lung Cancer

“…The findings argue that the activated receptor such as VEGF plays a role as an antigenic factor and that VEGFR‐2 is necessary for tumor metastasis 46. Western blot bands demonstrated a decrease in phosphorylation of VEGFR‐2 after treatment with SiO 2 @LDH‐VP16 on A549 cells.…”