Reduced smooth muscle-fibroblasts transformation potentially decreases intestinal wound healing and colitis-associated cancer in ageing mice.

Cancer and impaired tissue wound healing with ageing are closely related to the quality of life of the elderly population. Given the increased incidence of cancer and the population ageing trend globally, it is very important to explore how ageing impairs tissue wound healing and spontaneous cancer. In a murine model of DSS-induced acute colitis and AOM/DSS-induced colitis-associated cancer (CAC), we found ageing significantly decreases intestinal wound healing and simultaneous CAC initiation, although ageing does not affect the incidence of AOM-induced, sporadic non-inflammatory CRC. Mechanistically, reduced fibroblasts were observed in the colitis microenvironment of ageing mice. Through conditional lineage tracing, an important source of fibroblasts potentially derived from intestinal smooth muscle cells (ISMCs) was identified orchestrating intestinal wound healing and CAC initiation in young mice. However, the number of transformed fibroblasts from ISMCs significantly decreased in ageing mice, accompanied by decreased intestinal wound healing and decreased CAC initiation. ISMCs-fibroblasts transformation in young mice and reduction of this transformation in ageing mice were also confirmed by ex-vivo intestinal muscular layer culture experiments. We further found that activation of YAP/TAZ in ISMCs is required for the transformation of ISMCs into fibroblasts. Meanwhile, the reduction of YAP/TAZ activation in ISMCs during intestinal wound healing was observed in ageing mice. Conditional knockdown of YAP/TAZ in ISMCs of young mice results in reduced fibroblasts in the colitis microenvironment, decreased intestinal wound healing and decreased CAC initiation, similar to the phenotype of ageing mice. In addition, the data from intestine samples derived from inflammatory bowel disease (IBD) patients show that activation of YAP/TAZ also occurs in ISMCs from these patients. Collectively, our work reveals an important role of the ageing stromal microenvironment in intestinal wound healing and CAC initiation. Furthermore, our work also identified a potential source of fibroblasts involved in colitis and CAC.

[Effects of Msp on the Proliferation, Migration and Invasion of Human Non-small Cell Lung Cancer Cells].

OBJECTIVES: To determine the effects of macrophage stimulating protein (Msp) on the proliferation, migration and invasion of human non-small cell lung cancer cells PC14. METHODS: The eukaryotic expression vector for st1was constructed and transfected into Msp(-)and RON(-)human non-small cell lung cancer cells PC14. The expression of st1mRNA in PC14 cells was observed by RT-PCR. The expression levels of Msp protein in PC14, PC14-st1-pEGFP-N1 and PC14-pEGFP-N1 groups as well as the expression of RON in PC14 and SKBR-3 cells were detected by Western blot. RAW264.7 (mouse monocyte macrophage) and SKBR-3 cells were cultured in the supernatant of cells(PC14, PC14-st1-pEGFP-N1and PC14-pEGFP-N1 groups)and tested with Transwell microporous membrane, through which the biologic activity of Msp was evaluated by calculating the cell number migrated. The proliferation of PC14 was measured by MTT assay. The capabilities of PC14 to migrate and invade were measured by Transwell chamber and Matrigel invasion tests, respectively. RESULTS: The expressions of mRNA and protein of Mst1 in PC14 were stable after transfection with Mst1. Msp (PC14-st1 -pEGFP-N1 group) promoted the migration of RON (+) cells (SKBR-3 and RAW264.7). Compared with PC14 and PC14-pEGFP-N1 groups, the proliferation, migration and invasion of PC14 cells in PC14-st1 -pEGFP-N1 group were inhibited significantly. CONCLUSIONS: Msp can promote the migration of RON (+) cancer cells in paracrine secretion manner and inhibit the proliferation, migration and invasion of human non-small cell lung cancer cells PC14 in an unknown way.