RAB20 Promotes Proliferation via G2/M Phase through the Chk1/cdc25c/cdc2-cyclinB1 Pathway in Penile Squamous Cell Carcinoma

Abstract

RAB20, a member of the RAS GTPase oncogene family, is overexpressed in several cancers with poor outcomes, promoting tumorigenesis and inducing genomic instability. Here, we performed comprehensive genomic sequencing on eight penile squamous cell carcinoma (PSCC) and normal tissue pairs and found that RAB20 was upregulated in tumors, especially in metastatic lymph nodes. RAB20 overexpression in tumors was further verified by qPCR, Western blotting, and immunohistochemistry of our newly established PSCC cell lines and paired tissues. The clinical significance of RAB20 was validated in 259 PSCC patients, the largest cohort to date, and high RAB20 expression positively correlated with the T, N, M status, extranodal extension, and clinical stage (all p < 0.01). RAB20 was an unfavorable independent prognostic indicator in the survival analysis (p = 0.011, HR = 2.090; 95% Cl: 1.183–4.692), and PSCC patients with high RAB20 expression experienced shorter 5-year cancer-specific survival times (p < 0.001). Furthermore, tumorigenesis assays demonstrated that RAB20 knockdown inhibited cell proliferation, migration, and colony formation in vitro and tumor growth in vivo. RAB20 depletion also induced PSCC cell cycle arrest at G2/M by increasing Chk1 expression and promoting cdc25c phosphorylation to reduce cdc2-cyclinB1 complex formation. Our study revealed an oncogenic role for RAB20 in promoting PSCC cell proliferation at the G2/M phase via the Chk1/cdc25c/cdc2-cyclinB1 pathway. Thus, RAB20 could be a promising prognostic biomarker of advanced PSCC with poor patient survival outcomes and could be a potential therapeutic target.

TUBB, a robust biomarker with satisfying abilities in diagnosis, prognosis, and immune regulation via a comprehensive pan-cancer analysis

“…For example, Lv S et al found that inhibiting CYCLINB1 resulted in suppressed proliferation, invasion, and epithelial mesenchymal transition of hepatocellular carcinoma cells and enhanced sensitivity to TRAIL-Induced apoptosis ( Lv et al, 2020 ). Also, CYCLINB1 is a defined biomarker in esophageal squamous cell carcinoma ( Li et al, 2023 ), penile squamous cell carcinoma ( Tan et al, 2022 ), gastric cancer ( Li et al, 2021 ), breast cancer ( Liu et al, 2019 ), nasopharyngeal carcinoma ( Xie et al, 2019 ), etc. As an important factor in so many cancers, our studies provided a new idea that TUBB may function in tumor formation by interacting with the CYCLINB1 protein.…”

miR-138-5p-mediated HOXD11 promotes cell invasion and metastasis by activating the FN1/MMP2/MMP9 pathway and predicts poor prognosis in penile squamous cell carcinoma

“…Currently, chemotherapy options and e cacy are limited in PSCC, and there is still a lack of available targeted therapies in clinical practice and relevant basic research [3,8]. Several studies have reported that RAB20 and IDO1 overexpression promote cell proliferation and induce immunosuppression in PSCC [12,21]. Other serum biomarkers, such as CXCL5, CXCL13 and CCL20, are associated with nodal metastasis in small cohorts [33][34][35].…”

“…The absorbance was read on a spectrophotometer at 450 nm for 7 consecutive days. In addition, wound healing assays and Matrigel Transwell invasion assays were used to evaluate the progressive capability of cells as described in our previous study [21].…”

“…R software was used for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses using the clusterPro ler package. Gene-set enrichment analysis (GSEA) was conducted by GSEA tools version 4.1 (http://www.broadinstitute.org/gsea) as previously described [21].…”

“…For IHC staining, 4-µm para n-embedded tissue sections were processed according to standard pathologic procedures as previously described [21]. For ICC, cells were seeded on glass slides in 12-well plates and xed in 4% paraformaldehyde for 15 minutes.…”