Gene sequencing and expression of Raf-1 in lymphatic metastasis of hypopharyngeal carcinoma

OBJECTIVE: We performed differential gene screening for lymphatic metastasis of hypopharyngeal carcinoma by gene sequencing. We also aimed to investigate the expression and clinicopathological significance of the screened gene in hypopharyngeal carcinoma lymphatic metastasis. METHODS: The clinicopathological characteristics of 98 patients with hypopharyngeal carcinoma were collected to make survival analysis by Kaplan-Meier & log-rank test. Six cases of tumor tissues from patients with or without lymphatic metastasis were used for gene sequencing of differentially expressed genes. The most frequently differently expressed genes were validated by RT-PCR and Western blot in another 20 patients diagnosed for hypopharyngeal carcinoma. A total of 70 cases of hypopharyngeal carcinoma tumor tissues and normal tissues were investigated to examine the immunohistochemical expression and to explore the prognostic value by Kaplan-Meier & log-rank test and Cox's test. RESULTS: Lymphatic metastasis has been proved to cause a reduction in postoperative survival of patients with hypopharyngeal carcinoma. The results of gene sequencing analysis showed that Raf-1 was a differentially expressed gene in lymphatic metastasis of hypopharyngeal carcinoma. Moreover, the expression of Raf-1 was significantly up-regulated in tumor tissues of lymphatic metastasis patients compared to non-lymphatic metastasis tumor tissues and normal tissues. Meanwhile, Raf-1 had been verified to be an independent risk factor affecting the prognosis of hypopharyngeal carcinoma. CONCLUSIONS: For the first time, we investigated Raf-1 as an independent prognostic risk factor of lymphatic metastasis in hypopharyngeal carcinoma. It suggests that Raf-1 may serve as an important potential biomarker in preventing and diagnosing lymphatic metastasis in patients with hypopharyngeal carcinoma and improving the prognosis of patients.