Role of RHO family interacting cell polarization regulators (RIPORs) in health and disease: Recent advances and prospects

The RHO GTPase family has been suggested to play critical roles in cell growth, migration, and polarization. Regulators and effectors of RHO GTPases have been extensively explored in recent years. However, little attention has been given to RHO family interacting cell polarization regulators (RIPORs), a recently discovered protein family of RHO regulators. RIPOR proteins, namely, RIPOR1-3, bind directly to RHO proteins (A, B and C) via a RHO-binding motif and exert suppressive effects on RHO activity, thereby negatively influencing RHO-regulated cellular functions. In addition, RIPORs are phosphorylated by upstream protein kinases under chemokine stimulation, and this phosphorylation affects not only their subcellular localization but also their interaction with RHO proteins, altering the activation of RHO downstream targets and ultimately impacting cell polarity and migration. In this review, we provide an overview of recent studies on the function of RIPOR proteins in regulating RHO-dependent directional movement in immune responses and other pathophysiological functions.

FAM65A as a novel prognostic biomarker in human tumors reveal by a pan-cancer analysis

BACKGROUND

Family with sequence similarity 65 member A (FAM65A), also known as RIPOR1, is differentially expressed between human tumor and non-tumor tissues in kinds of cancers. In addition, it was reported that the product of FAM65A may be a biomarker for cholangiocarcinoma patients. However, there is still no evidence on the relationship between the FAM65A and different types of tumors. Our study is mainly for exploring the prognostic values of FAM65A in pan-cancer and for further discovering a potential therapeutics target.

METHODS

We analyzed FAM65A expression, prognostic values, genetic alteration, protein phosphorylation, immune infiltration and enrichment analysis across different types of human malignant tumors based on The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets. Additionally, Real-Time PCR (RT-qPCR) was performed to further confirm the roles of FAM65A in the pathogenesis of colorectal cancer.

RESULTS

We found that FAM65A expression was associated with the prognosis of multiple human tumors, especially colorectal cancer. Moreover, we also observed that FAM65A was highly expressed in colorectal cancer through RT-qPCR. We observed that decreasing phosphorylation level of the S351 locus in colon adenocarcinoma, uterine corpus endometrial carcinoma and lung adenocarcinoma. And the expression of FAM65A was positively related to cancer-associated fibroblasts (CAFs) infiltration in many tumors, such as colon adenocarcinoma. Therefore, FAM65A may be a potential prognostic biomarker of human tumors.