Expression levels of clock genes <i>PER2</i> and <i>PER3</i> in nasopharyngeal carcinoma and their correlation with survival prognosis and other factors.

Abstract

e18055 Background: Nasopharyngeal carcinoma is a malignant tumor of the head and neck that originates from the mucosal epithelium of the nasopharynx. It has distinct geographical and racial distribution characteristics, with a particularly high incidence in Southeast Asia and southern China. The main reasons for treatment failure in nasopharyngeal carcinoma include distant metastasis and local recurrence. Therefore, there is an urgent need in clinical practice to explore new and effective prognostic markers to assess the survival and prognosis of nasopharyngeal carcinoma patients. This study investigates the expression levels of clock genes PER2 and PER3 in nasopharyngeal carcinoma tissues and their relationship with the survival prognosis of nasopharyngeal carcinoma patients, aiming to discover novel molecular markers for the prognosis of nasopharyngeal carcinoma. Methods: survival prognosis of nasopharyngeal carcinoma patients through bioinformatics analysis. Additionally, 64 tissue specimens of chronic nasopharyngeal inflammation and 64 tissue specimens of locally advanced nasopharyngeal carcinoma were included. All patients received standard concurrent radiotherapy or induction chemotherapy followed by concurrent radiotherapy. The mRNA levels and protein expression levels of PER2 and PER3 genes in the two groups of tissues were detected using qRT-PCR (Quantitative Real-time PCR) and immunohistochemical techniques. Statistical analysis was conducted using ROC curves, Kaplan-Meier survival analysis, and Cox proportional hazards model analysis. Results: The bioinformatics analysis revealed that the expressions of PER2 and PER3 genes were higher in chronic inflammatory tissues of the nasopharynx than in nasopharyngeal cancer tissues. Moreover, the 5-year overall survival rate (OS) of patients with high expression of PER2 and PER3 was better than that of the low-expression group (P &lt; 0.05). The results of qRT-PCR and immunohistochemistry showed that the mRNA and protein expressions of PER2 and PER3 genes in nasopharyngeal cancer tissues were lower than those in inflammatory tissues (P &lt; 0.05). The survival analysis indicated that the patients with high expression of PER2 and PER3 genes in nasopharyngeal cancer had better 1-, 3-, and 5-year OS and distant metastasis-free survival rate (DMFS) than those with low expression. The protein level expression of PER2 and PER3 genes was an independent prognostic factor for nasopharyngeal cancer patients (P &lt; 0.05). Conclusions: The PER2 and PER3 genes are expressed at a low level in nasopharyngeal carcinoma tissues, and patients in the low-expression group have a poorer prognosis compared to those in the high-expression group. The PER2 and PER3 genes are expected to become potential molecular markers for evaluating the prognosis of nasopharyngeal carcinoma.