ABSTRACT
PURPOSE: The minichromosomal maintenance (MCM) proteins are involved in the initiation and DNA replication. The role of MCM4 remains to be elucidated. The purpose of this study was to investigate the effects of MCM4 in laryngeal squamous cell carcinoma (LSCC) cell growth and apoptosis. METHODS: LSCC cell line UMSCC 5 was used in this study. The small interfering RNA (siRNA) of MCM 4 gene was used to identify the effects of MCM4 on the proliferation and apoptosis using methylimidazole tetrazolium (MTT) assay and flow-cytometry, respectively. Confirmed LSCC and adjacent non-tumor tissues were collected from 34 patients who were willing to participate in the study, from 2010 through 2015, from 163 patients undergoing treatment in the Department of Otorhinolaryngology/Head and Neck Surgery of Beijing Tongren Hospital in Capital Medical University of P.R. China. Immunohistochemical staining of MCM4 expression in the resected tissues was performed to analyze the correlation between its expression and the clinicopathological characteristics. RESULTS: The results showed that siRNA of MCM4 could significantly inhibit LSCC cell line UMSCC 5 proliferation and induce apoptosis. MCM4 mRNA was higher expressed in carcinoma tissues than in adjacent normal tissues. MCM4 expression was correlated with male gender, smoking history and poor differentiation. CONCLUSIONS: We noticed a significant role for MCM4 overexpression in human LSCC tissues and their corresponding adjacent non-neoplastic tissues and found that siRNA of MCM4 can significantly decrease the proliferation of cancer cells. It is suggested that MCM4 profiling could potentially be used to predict response to treatment and prognosis in LSCC.
