Rac GTPase-Activating Protein 1 (RACGAP1) as an Oncogenic Enhancer in Esophageal Carcinoma

Integrating bioinformatics and machine learning methods to analyze diagnostic biomarkers for HBV-induced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a malignant tumor. It is estimated that approximately 50-80% of HCC cases worldwide are caused by hepatitis b virus (HBV) infection, and other pathogenic factors have been shown to promote the development of HCC when coexisting with HBV. Understanding the molecular mechanisms of HBV-induced hepatocellular carcinoma (HBV-HCC) is crucial for the prevention, diagnosis, and treatment of the disease. In this study, we analyzed the molecular mechanisms of HBV-induced HCC by combining bioinformatics and deep learning methods. Firstly, we collected a gene set related to HBV-HCC from the GEO database, performed differential analysis and WGCNA analysis to identify genes with abnormal expression in tumors and high relevance to tumors. We used three deep learning methods, Lasso, random forest, and SVM, to identify key genes RACGAP1, ECT2, and NDC80. By establishing a diagnostic model, we determined the accuracy of key genes in diagnosing HBV-HCC. In the training set, RACGAP1(AUC:0.976), ECT2(AUC:0.969), and NDC80 (AUC: 0.976) showed high accuracy. They also exhibited good accuracy in the validation set: RACGAP1(AUC:0.878), ECT2(AUC:0.731), and NDC80(AUC:0.915). The key genes were found to be highly expressed in liver cancer tissues compared to normal liver tissues, and survival analysis indicated that high expression of key genes was associated with poor prognosis in liver cancer patients. This suggests a close relationship between key genes RACGAP1, ECT2, and NDC80 and the occurrence and progression of HBV-HCC. Molecular docking results showed that the key genes could spontaneously bind to the anti-hepatocellular carcinoma drugs Lenvatinib, Regorafenib, and Sorafenib with strong binding activity. Therefore, ECT2, NDC80, and RACGAP1 may serve as potential biomarkers for the diagnosis of HBV-HCC and as targets for the development of targeted therapeutic drugs.

Epidemiological and transcriptome data identify shared gene signatures and immune cell infiltration in type 2 diabetes and non-small cell lung cancer

BACKGROUND

Numerous previous studies have reported an association between type 2 diabetes mellitus (T2DM) and lung cancer risk, but the underlying mechanism of the interaction remains unclear. This study aimed to investigate the shared genetic features and immune infiltration processes between lung cancer and T2DM.

METHODS

Epidemiological data from the National Health and Nutrition Examination Survey (NHANES) 2000-2018 was used to explore the relationship between lung cancer and diabetes systematically. In addition, we also used bioinformatics methods to analyze the transcriptome data from the Gene Expression Omnibus (GEO) to explore the potential functional mechanisms from the perspective of genes and immune infiltration.

RESULTS

Logistic regression analysis showed that prediabetes (OR = 3.289,95%CI 1.231, 8.788, p = 0.01760, model 3)and type 2 diabetes (OR = 3.032 95%CI,1.015, 9.054, p = 0.04689) were significantly associated with an increased risk of lung cancer after adjusting for multiple covariates. Data from NHANES showed an inverted U-shaped relationship between fasting blood glucose and glycosylated haemoglobin and the risk of lung cancer (P for non-linear < 0.001). Transcriptome data showed that we screened 57 co-DEGs, of which 25 were up-regulated co-DEGs and 32 were down-regulated. Ten core DEGs were identified by bioinformatics analysis, which were SMC6, CDC27, CDC7, RACGAP1, SMC4, NCF4, NCF1, NCF2, SELPLG and CFP. Correlation analysis showed that some core DEGs were significantly associated with simultaneous dysregulation of immune cells.

CONCLUSION

The identified core genes of NSCLC and T2DM are associated with dysregulated immune cells, which provides a potential research avenue for diagnosing and treating lung cancer combined with diabetes.

FOXM1 transcriptional regulation of RacGAP1 activates the PI3K/AKT signaling pathway to promote the proliferation, migration, and invasion of cervical cancer cells

BACKGROUND

Cervical cancer (CC) is the most common gynecological tumor disease in women, which occurs at the junction of cervical squamous columnar epithelium. We investigated the effect and mechanism of transcription factor FOXM1 synergizing RacGAP1 in the proliferation, migration, and invasion of CC cells.

METHODS

Here, we analyzed the correlation between FOXM1 and RacGAP1 and the clinicopathological features of 68 CC patients. RT-qPCR was used to assess FOXM1 and RacGAP1 mRNA expression in CC tissues and cells. Cell proliferation was assessed by CCK-8 and EDU assays. Transwell assay was applied to test migration and invasion. Cell apoptosis was evaluated utilizing flow cytometry. ChIP and dual-luciferase reporter assays confirmed the interaction of FOXM1 and RacGAP1. Protein levels of FOXM1 and RacGAP1, as well as PI3K/AKT, were analyzed by Western blot.

RESULTS

FOXM1 expression was correlated with FIGO stage and histological grade, and RacGAP1 expression was correlated with histological grade. FOXM1 and RacGAP1 levels were increased in CC tissues, and higher expressed in human CC cell lines than that in an immortalized HPV-negative skin keratinocyte line (HaCaT). Depleted RacGAP1 suppressed CC cell proliferation, migration and invasion, and promoted apoptosis. RacGAP1 was a target gene of FOXM1, and FOXM1 positively regulated RacGAP1 expression. FOXM1 had a synergistic effect with RacGAP1 to exert oncogenic function in CC by activating the PI3K/AKT signaling.

CONCLUSION

FOXM1 cooperates with RacGAP1 to induce CC cell proliferation, migration and invasion, inhibit apoptosis, and regulate PI3K/AKT signaling to promote CC progression.

m6A-modified circASXL1 promotes proliferation and migration of ovarian cancer through the miR-320d/RACGAP1 axis

Ovarian cancer (OC) is one of the most common malignant tumors in women. Circular RNAs (circRNAs) can potentially regulate the development of OC. Therefore, this study investigated the role of circASXL1 in OC progression. Cell functions were assessed by MTT, colony formation, wound healing, and transwell assays. RIP and dual luciferase reporter assays confirmed the relationship between miR-320d and circASXL1 or RACGAP1. MeRIP was utilized to detect m6A levels. Xenograft tumor was established for in vivo experiments. CircASXL1 and RACGAP1 levels were increased in OC tissues and cells, whereas miR-320d expression was decreased. Upregulation of circASXL1 was associated with poor prognosis in OC patients. CircASXL1 silencing suppressed OC cell proliferation, migration and invasion in vitro and in vivo. Mechanistically, METTL3/IGF2BP1-mediated m6A modification maintained circASXL1 stability and upregulated its expression. CircASXL1 was a ceRNA that sequestrated miR-320d from RACGAP1, leading to increased RACGAP1 expression. CircASXL1 promoted OC cell proliferation, migration and invasion via the miR-320d/RACGAP1 axis. Therefore, m6A-modified circASXL1 acts as an oncogene in OC by targeting miR-320d and activating RACGAP1/PI3K/Akt pathway, which provides novel promising biomarkers for OC diagnosis.

Rac GTPase activating protein 1 promotes the glioma growth by regulating the expression of MCM3

Glioma is the most common tumor of the nervous system. The diffuse growth and proliferation of glioma poses great challenges for its treatment. Here, Transcriptomic analysis revealed that Rac GTPase activating protein 1 (RACGAP1) is highly expressed in glioma. RACGAP1 has been shown to play an important role in the malignant biological progression of a variety of tumors. However, the underlying role and mechanism in glioma remain poorly understood. By using quantitative real-time polymerase chain reaction (qRT-PCR), western blot, immunohistochemistry and Orthotopic mouse xenografts, we confirmed that knockdown of RACGAP1 impeded cell proliferation in glioma and prolonged the survival of orthotopic mice. Interestingly, we also found that inhibiting the expression of RACGAP1 reduced the expression of minichromosome maintenance 3 (MCM3) through RNA-seq and rescue assay, while Yin Yang 1 (YY1) transcriptionally regulated RACGAP1 expression. Furthermore, T7 peptide-decorated exosome (T7-exo) is regard as a promising delivery modality for targeted therapy of glioma, and the T7-siRACGAP1-exo significantly improved the survival time of glioma bearing mice. These results suggested that targeting RACGAP1 may be a potential strategy for glioma therapy.

Assessment of RACGAP1 as a Prognostic and Immunological Biomarker in Multiple Human Tumors: A Multiomics Analysis

Several recent studies have pointed out that arc GTPase activating protein 1 (RACGAP1) is a putative oncogene in many human tumors. However, to date, no pan-cancer analysis has been performed to study the different aspects of this gene expression and behavior in tumor tissues. Here, we applied several bioinformatics tools to perform a comprehensive analysis for RACGAP1. First, we assessed the expression of RACGAP1 in several types of human tumors and tried to correlate that with the stage of the tumors analyzed. We then performed a survival analysis to study the correlation between RACGAP1 upregulation in tumors and the clinical outcome. Additionally, we investigated the mutation forms, the correlation with several immune cell infiltration, the phosphorylation status of the interested protein in normal and tumor tissues, and the potential molecular mechanisms of RACGAP1 in cancerous tissue. The results demonstrated that RACGAP1, a highly expressed gene across several types of tumors, correlated with a poor prognosis in several types of human cancers. Moreover, it was found that RACGAP1 affects the tumor immune microenvironment by influencing the infiltration level of several immune cells. Collectively, the current study provides a comprehensive overview of the oncogenic roles of RACGAP1, where our results nominate it as a potential prognostic biomarker and a target for antitumor therapy development.

Long Non-Coding RNA MAPK8IP1P2 Inhibits Lymphatic Metastasis of Thyroid Cancer by Activating Hippo Signaling via Sponging miR-146b-3p

The principal issue derived from thyroid cancer is its high propensity to metastasize to the lymph node. Aberrant exprssion of long non-coding RNAs have been extensively reported to be significantly correlated with lymphatic metastasis of thyroid cancer. However, the clinical significance and functional role of lncRNA-MAPK8IP1P2 in lymphatic metastasis of thyroid cancer remain unclear. Here, we reported that MAPK8IP1P2 was downregulated in thyroid cancer tissues with lymphatic metastasis. Upregulating MAPK8IP1P2 inhibited, while silencing MAPK8IP1P2 enhanced anoikis resistance in vitro and lymphatic metastasis of thyroid cancer cells in vivo. Mechanistically, MAPK8IP1P2 activated Hippo signaling by sponging miR-146b-3p to disrupt the inhibitory effect of miR-146b-3p on NF2, RASSF1, and RASSF5 expression, which further inhibited anoikis resistance and lymphatic metastasis in thyroid cancer. Importantly, miR-146b-3p mimics reversed the inhibitory effect of MAPK8IP1P2 overexpression on anoikis resistance of thyroid cancer cells. In conclusion, our findings suggest that MAPK8IP1P2 may serve as a potential biomarker to predict lymphatic metastasis in thyroid cancer, or a potential therapeutic target in lymphatic metastatic thyroid cancer.