Silencing of miR-148a in cancer-associated fibroblasts results in WNT10B-mediated stimulation of tumor cell motility

Abstract

The tumor microenvironment has an important role in cancer progression. Here we show that miR-148a is downregulated in 15 out of 16 samples (94%) of cancer-associated fibroblasts (CAFs) compared with matched normal tissue fibroblasts (NFs) established from patients with endometrial cancer. Laser-capture microdissection of stromal cells from normal tissue and endometrial cancer confirmed this observation. Treatment of cells with 5-aza-deoxycytidine stimulated the expression of miR-148a in the majority of CAFs implicating DNA methylation in the regulation of miR-148a expression. Investigation of miR-148a function in fibroblasts demonstrated that conditioned media (CM) from CAFs overexpressing miR-148a significantly impaired the migration of five endometrial cancer cell lines without affecting their growth rates in co-culture experiments. Among predicted miR-148a target genes are two WNT family members, WNT1 and WNT10B. Activation of the WNT/β-catenin pathway in CAFs was confirmed by microarray analysis of gene expression and increased activity of the SuperTOPFIash luciferase reporter. We found elevated levels of WNT10B protein in CAFs and its level decreased when miR-148a was re-introduced by lentiviral infection. The 3′-UTR of WNT10B, cloned downstream of luciferase cDNA, suppressed luciferase activity when co-expressed with miR-148a indicating that WNT10B is a direct target of miR-148a. In contrast to the effect of miR-148a, WNT10B stimulated migration of endometrial cancer cell lines. Our findings have defined a molecular mechanism in the tumor microenvironment that is a novel target for cancer therapy.

MicroRNA‐106b in cancer‐associated fibroblasts from gastric cancer promotes cell migration and invasion by targeting PTEN

“…Several previous studies have suggested that microRNAs play an important role in regulation of specific genes present in the cells of the tumor microenvironment, which plays a vital role in tumorigenesis of various human cancer including stomach carcinoma [24][25][26]. For instance, Naito et al [27] have shown that miR-143 is highly expressed in stromal fibroblasts of scirrhous type gastric cancer, where it may promote tumor progression by regulating the expression of collagen type III through TGF-b/SMAD signaling pathway.…”

Cell‐to‐cell communication: microRNAs as hormones

“…CAFs have been shown to stimulate cancer progression and proliferation through helping create the extracellular matrix (ECM) and through the secretion of a variety of cytokines, chemokines, and growth factors, such as vascular endothelial growth factor (VEGF), transforming growth factor‐β (TGF‐β), and fibroblast growth factor 2 (FGF2) (Kalluri, 2016; Kalluri and Zeisberg, 2006; Orimo et al ., 2005; Shen et al ., 2016). Accumulating evidence suggests that miRNAs play key roles in the activation and transition of fibroblasts (Aprelikova et al ., 2013; Mitra et al ., 2012). …”

Fibroblast heterogeneity in the cancer wound

“…Reprogramming cells into CAFs also involves changes in miR expression, affecting target genes posttranscriptionally (Aprelikova et al, 2010(Aprelikova et al, , 2013Musumeci et al, 2011;Bronisz et al, 2012;Mitra et al, 2012;Masamune et al, 2014). Furthermore, epigenetic changes, such as global DNA hypomethylation frequently seen in neoplastic cells, have also been observed in CAFs (Jiang et al, 2008).…”