No abstract

In this study, we compared the expression of epithelial membrane protein 1 (EMP1) on the steady-state mRNA level (by quantitative real-time PCR) and on the protein level (by western immunoblot and immunohistochemistry) in 51 pairs of laryngeal carcinoma tissues and matched cancer-free peritumor tissues, and we analyzed the correlation between EMP1 expression and different clinicopathological factors. Furthermore, we ectopically expressed EMP1 in human laryngeal carcinoma Hep-2 cells and examined the effects on cell viability, apoptosis, colonogenicity, and motility, by MTT assay, flow cytometry, colony formation assay and Transwell migration assay, respectively. EMP1 expression (on both the mRNA and protein levels) was significantly lower in the cancer tissues than in matched peritumor tissues (P<0.05). In laryngeal cancers, the level of EMP1 protein was correlated with histological grade (P<0.05), but not with age, gender, clinical stage, cancer subtype or lymph node metastasis (P>0.05). Functionally, ectopic expression of EMP1 in Hep-2 cells significantly reduced cell viability, colony formation, and migration, but enhanced apoptosis. Therefore, EMP1 is a tumor suppressor in laryngeal carcinoma. Boosting EMP1 expression in laryngeal carcinoma initiates multiple anticancer phenotypes and thus presents a promising therapeutic strategy for laryngeal cancer.

Ribonuclease P/MRP Subunit P40 (RPP40), a component of ribonuclease P and multimeric ribonuclease P complex, was reported as one of the promoting factors for the chemoresistance of acute myeloid leukemia and a recurrence predictor of early-stage triple-negative breast cancer. However, the functional role of RPP40 in uterine corpus endometrial carcinoma (UCEC) is unclear. In this study, comprehensive bioinformatic analyses were conducted to explore the predictive role of RPP40 on UCEC diagnosis and prognosis, as well as the underlying mechanism. Differential analyses of multiple databases showed that both messenger RNA (mRNA) and the protein expression of RPP40 were significantly upregulated in UCEC tumor tissues. Furthermore, the RPP40 mRNA expression level was significantly correlated with the clinicopathological characteristics of UCEC patients, including the clinical stage, primary therapy outcome, histological type, histologic grade, overall survival event, disease-specific survival event, and progression-free interval event. Receiver operating characteristic (ROC) analysis showed that RPP40 was a reliable predictor for UCEC diagnosis with an area under the curve (AUC) of 0.775, a sensitivity of 0.829, and a specificity of 0.719. Kaplan–Meier, Cox regression, and nomogram analyses showed that high RPP40 expression was an independent prognostic factor for the 1-year, 3-year, and 5-year survival of UCEC patients. In addition, the enrichment analysis of RPP40-associated differentially expressed genes and correlation analyses showed that the expression of RPP40 was correlated with the regulation of extracellular matrix and immune cell infiltration. In conclusion, the upregulation of RPP40 is significantly correlated with the poor survival and tumor microenvironment of UCEC, suggesting that RPP40 is a promising biomarker of poor prognosis and a potential target of chemotherapy or immunotherapy in UCEC.