FERM domain-containing protein 6 identifies a subpopulation of varicose nerve fibers in different vertebrate species

FERM domain-containing protein FRMD6 activates the mTOR signaling pathway and promotes lung cancer progression

FRMD6, a member of the 4.1 ezrin-radixin-moesin domain-containing protein family, has been reported to inhibit tumor progression in multiple cancers. Here, we demonstrate the involvement of FRMD6 in lung cancer progression. We find that FRMD6 is overexpressed in lung cancer tissues relative to in normal lung tissues. In addition, the enhanced expression of FRMD6 is associated with poor outcomes in patients with lung squamous cell carcinoma (n = 75, P = 0.0054) and lung adenocarcinoma (n = 94, P = 0.0330). Cell migration and proliferation in vitro and tumor formation in vivo are promoted by FRMD6 but are suppressed by the depletion of FRMD6. Mechanistically, FRMD6 interacts and colocalizes with mTOR and S6K, which are the key molecules of the mTOR signaling pathway. FRMD6 markedly enhances the interaction between mTOR and S6K, subsequently increasing the levels of endogenous pS6K and downstream pS6 in lung cancer cells. Furthermore, knocking out FRMD6 inhibits the activation of the mTOR signaling pathway in Frmd6-/- gene KO MEFs and mice. Altogether, our results show that FRMD6 contributes to lung cancer progression by activating the mTOR signaling pathway.

CircRNA VPRBP inhibits tumorigenicity of cervical cancer via miR-93-5p/FRMD6 axis

BACKGROUND

Cervical cancer is a malignant tumor that threatens the life and health of women. Circular RNA (circRNA) is a research hotspot in human diseases including cervical cancer. However, the research of circRNA viral protein R-binding protein (circ_VPRBP) in cervical cancer is blank.

METHODS

Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of target genes in cervical cancer tissues and cells. The expression of related proteins was detected by western blot. The localization of circ_VPRBP was detected by nuclear cytoplasmic separation, and the stability of circ_VPRBP was verified by actinomycin D. After transfection with oligonucleotides and/or plasmids, cell proliferation, migration, invasion and apoptosis were detected by 3-(4, 5-dimethylthiazol-2-yl) -2, 5-diphenyl-2-H-tetrazolium bromide (MTT), colony formation, 5-ethynyl-2'-deoxyuridine (EdU), transwell, or flow cytometry assays. Mechanistically, the interaction between microRNA-93-5p (miR-93-5p) and circ_VPRBP/FERM domain containing 6 (FRMD6) was verified by dual luciferase reporter assay. Animal experiment was conducted to investigate the role of circ_VPRBP in vivo.

RESULTS

Circ_VPRBP was down-regulated in cervical cancer tissues and cells, and overexpression of circ_VPRBP inhibited proliferation and promoted apoptosis of Caski and C33A cells. MiR-93-5p was a target of circ_VPRBP, and miR-93-5p mimic reversed the effect of circ_VPRBP on cell behavior. FRMD6 was a downstream target of miR-93-5p, and down-regulated FRMD6 reversed the cell viability, migration and invasion of cervical cancer cells inhibited by anti-miR-93-5p. Circ_VPRBP inhibited tumor growth by regulating miR-93-5p and FRMD6 in vivo.

CONCLUSION

Circ_VPRBP inhibited cell proliferation, migration and invasion and promoted cell apoptosis of cervical cancer cells by regulating miR-93-5p/FRMD6 axis.

Willin/FRMD6: A Multi-Functional Neuronal Protein Associated with Alzheimer's Disease

The FERM domain-containing protein 6 (FRMD6), also known as Willin, is an upstream regulator of Hippo signaling that has recently been shown to modulate actin cytoskeleton dynamics and mechanical phenotype of neuronal cells through ERK signaling. Physiological functions of Willin/FRMD6 in the nervous system include neuronal differentiation, myelination, nerve injury repair, and vesicle exocytosis. The newly established neuronal role of Willin/FRMD6 is of particular interest given the mounting evidence suggesting a role for Willin/FRMD6 in Alzheimer's disease (AD), including a series of genome wide association studies that position Willin/FRMD6 as a novel AD risk gene. Here we describe recent findings regarding the role of Willin/FRMD6 in the nervous system and its actions in cellular perturbations related to the pathogenesis of AD.