The microRNA‑200 family acts as an oncogene in colorectal cancer by inhibiting the tumor suppressor RASSF2

This study aimed to determine whether manipulation of the microRNA‑200 (miR‑200) family could influence colon adenocarcinoma cell behavior. The miR‑200 family has a significant role in tumor suppression and functions as an oncogene. In vitro studies on gain and loss of function with small interfering RNA demonstrated that the miR‑200 family could regulate RASSF2 expression. Knockdown of the miR‑200 family in the HT‑29 colon cancer cell line increased KRAS expression but decreased signaling in the MAPK/ERK signaling pathway through reduced ERK phosphorylation. Increased expression of the miR‑200 family in the CCD‑841 colon epithelium cell line increased KRAS expression and led to increased signaling in the MAPK/ERK signaling pathway but increased ERK phosphorylation. Functionally, knockdown of the miR‑200 family led to decreased cell proliferation in the HT‑29 cells; therefore, increased miR‑200 family expression could increase cell proliferation in the CCD‑841 cell line. The present study included a large paired miR array dataset (n=632), in which the miR‑200 family was significantly found to be increased in colon cancer when compared with normal adjacent colon epithelium. In a miR‑seq dataset (n=199), the study found that miR‑200 family expression was increased in localized colon cancer compared with metastatic disease. Decreased expression was associated with poorer overall survival. The miR‑200 family directly targeted RASSF2 and was inversely correlated with RASSF2 expression (n=199, all P<0.001). Despite the well‑defined role of the miR‑200 family in tumor suppression, the present findings demonstrated a novel function of the miR‑200 family in tumor proliferation

Fibronectin Extra Domains tune cellular responses and confer topographically distinct features to fibril networks

International audienceCellular fibronectin (FN; also known as FN1) variants harboring one or two alternatively spliced so-called extra domains (EDB and EDA) play a central bioregulatory role during development, repair processes and fibrosis. Yet, how the extra domains impact fibrillar assembly and function of the molecule remains unclear. Leveraging a unique biological toolset and image analysis pipeline for direct comparison of the variants, we demonstrate that the presence of one or both extra domains impacts FN assembly, function and physical properties of the matrix. When presented to FN-null fibroblasts, extra domain-containing variants differentially regulate pH homeostasis, survival, and TGF- β by tuning the magnitude of cellular responses, rather than triggering independent molecular switches. Numerical analyses of fiber topologies highlight significant differences in variant-specific structural features and provide a first step for the development of a generative model of FN networks to unravel assembly mechanisms and investigate the physical and functional versatility of extracellular matrix landscapes