An adventitious interaction of filamin A with RhoGDI2(Tyr153Glu)

WTAP regulates autophagy in colon cancer cells by inhibiting FLNA through N6-methyladenosine

Our study investigated the role of WTAP in colon cancer. We employed experiments including m6A dot blot hybridization, methylated RNA immunoprecipitation, dual-luciferase, and RNA immunoprecipitation to investigate the regulatory mechanism of WTAP. Western blot was performed to analyze the expression of WTAP, FLNA and autophagy-related proteins in cells. Our results confirmed the up-regulation of WTAP in colon cancer and its promoting effect on proliferation and inhibiting effect on apoptosis. FLNA was the downstream gene of WTAP and WTAP-regulated m6A modification led to post-transcriptional repression of FLNA. The rescue experiments showed that WTAP/FLNA could inhibit autophagy. WTAP-mediated m6A modification was confirmed to be crucial in colon cancer development, providing new insights into colon cancer therapy.

Screening of immunotherapy-related genes in bladder cancer based on GEO datasets

Background

As one of the most prevalent genitourinary cancers, bladder cancer (BLCA) is associated with high morbidity and mortality. Currently, limited indicators are available for early detection and diagnosis of bladder cancer, and there is a lack of specific biomarkers for evaluating the prognosis of BLCA patients. This study aims to identify critical genes that affect bladder cancer immunity to improve the diagnosis and prognosis of bladder cancer and to identify new biomarkers and targets for immunotherapy.

Methods

Two GEO datasets were used to screen differentially expressed genes (DEGs). The STRING database was used to construct a protein-protein interaction network of DEGs, and plug-in APP CytoHubba in Cytoscape was used to identify critical genes in the network. GO and KEGG analyses explored the functions and pathways of differential gene enrichment. We used GEPIA to validate the expression of differential genes, their impact on patient survival, and their relationship to clinicopathological parameters. Additionally, hub genes were verified using qRT-PCR and Western blotting. Immune infiltration analysis and multiple immunohistochemistry reveal the impact of Hub genes on the tumor microenvironment.

Result

We screened out 259 differential genes, and identified 10 key hub genes by the degree algorithm. Four genes (ACTA2, FLNA, TAGLN, and TPM1) were associated with overall or disease-free survival in BLCA patients and were significantly associated with clinical parameters. We experimentally confirmed that the mRNA and protein levels of these four genes were significantly decreased in bladder cancer cells. Immunoassays revealed that these four genes affect immune cell infiltration in the tumor microenvironment; they increased the polarization of M2 macrophages.

Conclusion

These four genes affect the tumor microenvironment of bladder cancer, provide a new direction for tumor immunotherapy, and have significant potential in the diagnosis and prognosis of bladder cancer.

RhoGDI2-Mediated Rac1 Recruitment to Filamin A Enhances Rac1 Activity and Promotes Invasive Abilities of Gastric Cancer Cells

Simple Summary

Rho GDP dissociation inhibitor 2 (RhoGDI2), a regulator of Rho family GTPase, has been known to promote tumor growth and malignant progression by activating Rac1 in gastric cancer. However, the precise molecular mechanism by which RhoGDI2 activates Rac1 in gastric cancer cells remains unclear. In this study, we found that interaction between RhoGDI2 and Rac1 is a prerequisite for the recruitment of Rac1 to Filamin A. Moreover, we found that Filamin A acts as a scaffold protein that mediates Rac1 activation. Furthermore, we found that Trio, a Rac1-specific GEF, is critical for Rac1 activation in gastric cancer cells. Conclusively, RhoGDI2 increases Rac1 activity by recruiting Rac1 to Filamin A and enhancing the interaction between Rac1 and Trio, which is critical for invasive ability of gastric cancer cells. Our findings suggest that RhoGDI2 might be a potential therapeutic target for reducing gastric cancer cell metastasis.

Abstract

Rho GDP dissociation inhibitor 2 (RhoGDI2), a regulator of Rho family GTPase, has been known to promote tumor growth and malignant progression in gastric cancer. We previously showed that RhoGDI2 positively regulates Rac1 activity and Rac1 activation is critical for RhoGDI2-induced gastric cancer cell invasion. In this study, to identify the precise molecular mechanism by which RhoGDI2 activates Rac1 activity, we performed two-hybrid screenings using yeast and found that RhoGDI2 plays an important role in the interaction between Rac1, Filamin A and Rac1 activation in gastric cancer cells. Moreover, we found that Filamin A is required for Rac1 activation and the invasive ability of gastric cancer cells. Depletion of Filamin A expression markedly reduced Rac1 activity in RhoGDI2-expressing gastric cancer cells. The migration and invasion ability of RhoGDI2-expressing gastric cancer cells also substantially decreased when Filamin A expression was depleted. Furthermore, we found that Trio, a Rac1-specific guanine nucleotide exchange factor (GEF), is critical for Rac1 activation and the invasive ability of gastric cancer cells. Therefore, we conclude that RhoGDI2 increases Rac1 activity by recruiting Rac1 to Filamin A and enhancing the interaction between Rac1 and Trio, which is critical for the invasive ability of gastric cancer cells.

The ontogeny of Robin sequence

The triad of micrognathia, glossoptosis, and concomitant airway obstruction defined as "Robin sequence" (RS) is caused by oropharyngeal developmental events constrained by a reduced stomadeal space. This sequence of abnormal embryonic development also results in an anatomical configuration that might predispose the fetus to a cleft palate. RS is heterogeneous and many different etiologies have been described including syndromic, RS-plus, and isolated forms. For an optimal diagnosis, subsequent treatment and prognosis, a thorough understanding of the embryology and pathogenesis is necessary. This manuscript provides an update about our current understanding of the development of the mandible, tongue, and palate and possible mechanisms involved in the development of RS. Additionally, we provide the reader with an up-to-date summary of the different etiologies of this phenotype and link this to the embryologic, developmental, and genetic mechanisms.

Filamin A (FLNA) regulates autophagy of bladder carcinoma cell and affects its proliferation, invasion and metastasis

PURPOSE

This research intended to explore the effect of FLNA on cell proliferation, invasion and migration in bladder carcinoma (BC).

METHODS

Microarray analysis was performed with the TCGA data, and the results were confirmed on 20 paired BC tissues and adjacent tissues using qRT-PCR and immunohistochemistry. Transmission electron microscope (TEM) and cell fluorescence assay were used to observe the quantity of autophagosomes. The expression of autophagy-related protein (LC3-I/II, p62) was detected by western blot. Cell proliferation was detected using CCK-8 and colony formation. The invasion and migration ability of the cell were tested by transwell and wound-healing assay. Tumor xenograft in BALB/c nude mice and HE staining were utilized to probe into the effects of FLNA-induced regulation of volume, weight and metastasis of tumors.

RESULTS

We confirmed that FLNA was down-regulated in BC tissues. TEM and fluorescence analysis proved that FLNA overexpression promoted autophagy in BC cells. Colony formation assay and CCK-8 experiment showed that FLNA overexpression suppressed the proliferation of BC cells. In addition, FLNA blocked cell cycle and promoted apoptosis of BC cell. Transwell assay and wound-healing assay further proved that FLNA suppressed invasion and migration ability in BC cell. Meanwhile, in vivo study indicated that FLNA inhibited the tumor growth.

CONCLUSION

Overexpression of FLNA suppressed the proliferation, migration and invasion of the BC cell, suggesting the potential role of FLNA in clinical treatment.