miRNA-29c Suppresses Lung Cancer Cell Adhesion to Extracellular Matrix and Metastasis by Targeting Integrin β1 and Matrix Metalloproteinase2 (MMP2)

Abstract

Our pilot study using miRNA arrays found that miRNA-29c (miR-29c) is differentially expressed in the paired low-metastatic lung cancer cell line 95C compared to the high-metastatic lung cancer cell line 95D. Bioinformatics analysis shows that integrin β1 and matrix metalloproteinase 2 (MMP2) could be important target genes of miR-29c. Therefore, we hypothesized that miR-29c suppresses lung cancer cell adhesion to extracellular matrix (ECM) and metastasis by targeting integrin β1 and MMP2. The gain-of-function studies that raised miR-29c expression in 95D cells by using its mimics showed reductions in cell proliferation, adhesion to ECM, invasion and migration. In contrasts, loss-of-function studies that reduced miR-29c by using its inhibitor in 95C cells promoted proliferation, adhesion to ECM, invasion and migration. Furthermore, the dual-luciferase reporter assay demonstrated that miR-29c inhibited the expression of the luciferase gene containing the 3′-UTRs of integrin β1 and MMP2 mRNA. Western blotting indicated that miR-29c downregulated the expression of integrin β1 and MMP2 at the protein level. Gelatin zymography analysis further confirmed that miR-29c decreased MMP2 enzyme activity. Nude mice with xenograft models of lung cancer cells confirmed that miR-29c inhibited lung cancer metastasis in vivo, including bone and liver metastasis. Taken together, our results demonstrate that miR-29c serves as a tumor metastasis suppressor, which suppresses lung cancer cell adhesion to ECM and metastasis by directly inhibiting integrin β1 and MMP2 expression and by further reducing MMP2 enzyme activity. The results show that miR-29c may be a novel therapeutic candidate target to slow lung cancer metastasis.

MicroRNA-29c Functions as a Tumor Suppressor by Targeting VEGFA in Lung Adenocarcinoma

“…MiR-29 family has been observed to be aberrently expressed in different types of cancer and be involved in biological functions including cell proliferation, cell cycle, senescence, differentiation, apoptosis and metastasis [19]. As for lung cancer, growing evidence indicates that miR-29 family functions as tumor suppressor and most studies focus on the biology of miR29b [8,[20][21][22][23]. However, despite the high similarity of miR-29a/b/c mature sequence, studies have revealed that different isoforms of miR-29 family may exert distinct functions [24,25].…”

“…However, despite the high similarity of miR-29a/b/c mature sequence, studies have revealed that different isoforms of miR-29 family may exert distinct functions [24,25]. Concerning the tumor suppressive role of miR-29c in lung cancer, it has been demonstrated to revert aberrant methylation by targeting DNA methyltransferases 3A and 3B and inhibit metastasis by targeting integrin beta1 and matrix metalloproteinase 2 [20,22]. As introduced above, the biological function of miRNA depends on cell types and LAD is a distinct subtype from other histological types.…”

“…Although bevacizumab could offer an OS benefit, it should be noted that the benefit is modest. Besides VEGFA, miR29c may target multiple genes and pathways to inhibit tumor growth and metastasis [20,22,[33][34][35], implicating miR-29c as a novel promising therapeutic target to provide clinical benefit. The biological effects of VEGF are mediated via binding to specific tyrosine kinase receptors including VEGFR-1 and VEGFR-2.…”

miR-17-5p down-regulation contributes to erlotinib resistance in non-small cell lung cancer cells

“…In our study, we first measured the expression levels of a panel of miRNAs which have been shown to play important roles in certain cancer types including NSCLC [36][37][38][39][40][41]. Among these miRNAs, miR-29c-3p and miR-497-5p were up-regulated but miR-17-5p was down-regulated in A549-ER cells.…”

Role of wild-type p53-induced phosphatase 1 in cancer

“…A previous study demonstrated that miR-29c is downregulated in liver cancer and may affect the apoptosis, tumorigenesis, and prognosis of tumor cells (46). Previous studies have revealed that the overexpression of miR-29c inhibits cancer cell proliferation and metastasis, as well as inducing cell cycle arrest (47,48). Wip1 was also revealed to be significantly upregulated in hepatocellular carcinoma and may contribute to the development of this cancer (49).…”