RNA-binding protein with serine-rich domain 1 regulates microsatellite instability of uterine corpus endometrial adenocarcinoma

OBJECTIVE: To determine the role of RNA-binding protein with serine-rich domain 1 (RNPS1) in uterine corpus endometrial carcinoma (UCEC), the role of RNPS1 knockdown in UCEC development in vitro and in vivo, and the relationship between RNPS1 and mismatch repair (MMR) in UCEC. METHODS: We predicted the potential function of RNPS1 using bioinformatics systems. The expression of RNPS1 in tissues and cell lines was analyzed by western blotting and immunohistochemistry. The expression of RNPS1 in MMR was assessed using bioinformatics and western blotting. The proliferation and apoptosis of UCEC cells were assessed under RNPS1 knockdown conditions, and RNPS1 regulation in MMR was detected by suppressing Notch signaling. Associations between RNPS1 and gene mutations in UCEC and prognosis were analyzed. RESULTS: The RNPS1 level was higher in UCEC tumors than in normal tissues and tumors or RL952 cells. Prognostic outcomes were worse when UCEC showed abundant RNPS1 expression. Lentiviral RNPS1 knockdown weakened tumor cell proliferation and suppressed biomarker expression, reduced the tumor volume, promoted apoptosis in vitro and in vivo, and inhibited UCEC development. Increased MutS homolog 2 (MSH2) and MutS homolog 6 (MSH6) levels in MMR after RNPS1 knockdown were reversed by inhibiting Notch signaling. Furthermore, RNPS1 was associated with mutations in NAA11, C2orf57, NUPR1, and other genes involved in UCEC prognosis. CONCLUSION: RNPS1 may regulate the expression levels of MSH2 and MSH6 in MMR, enhancing the proliferation, development, and prognosis of UCEC through a Notch signaling pathway in UCEC. Our study offers a new method and strategy for delaying UCEC development through modulating MMR

Modulation of Corneal Fibroblast Contractility within Fibrillar Collagen Matrices

PURPOSE. To investigate the migratory and contractile behavior of isolated human corneal fibroblasts in fibrillar collagen matrices. METHODS. A telomerase-infected, extended-lifespan human corneal fibroblast cell line (HTK) was transfected by using a vector for enhanced green fluorescent protein (GFP)-α-actinin. Cells were plated at low density on top of or within 100-μm-thick fibrillar collagen lattices. After 18 hours to 7 days, time-lapse imaging was performed. At each 1- to 3-minute interval, GFP and Nomarski differential interference contrast (DIC) images were acquired in rapid succession. Serum-containing (S+) medium was used initially for perfusion. After 2 hours, perfusion was switched to either serum-free (S-) or S+ medium containing the Rho-kinase inhibitor Y-27632 for 1 to 2 hours. Finally, perfusion was changed back to S+ medium for 1 hour. RESULTS. Two to 4 days after plating, many cells underwent spontaneous contraction and/or relaxation in S+ medium. A decrease in the distance between consecutive α-actinin-dense bodies along stress fibers was measured during contraction, and focal adhesion and matrix displacements correlated significantly. Removal of serum or inhibition of Rho-kinase induced cell body elongation and relaxation of matrix stress, as confirmed using finite element modeling. Rapid formation and extension of pseudopodia and filopodia were also observed, and transient tractional forces were generated by these extending processes. CONCLUSIONS. Cultured human corneal fibroblasts can undergo rapid changes in the subcellular pattern of force generation that are mediated, in part, by Rho-kinase. Sarcomeric shortening of stress fibers in contracting corneal fibroblasts is also demonstrated for the first time