Gene Expression of Ran GTPase Network in HNSCC Cell Lines

Objectives: Head and neck squamous cell carcinoma (HNSCC) is one of the most common types of human cancer with frequent recurrence and lymph node metastasis. Currently, limited chemotherapy is available for HNSCC patients. Therefore, identification of metastasis-associated factors is of clinical importance due to extremely poor prognosis in patients with locally advanced disease. The small GTPase Ras-related nuclear Ran is a multifunctional protein with an established role in mitotic cell division including mitotic spindle assembly and nuclear envelope formation. Importantly, Ran and its associated proteins has been shown to be required for the survival of many types of cancer cells. The aim of this study was to examine levels of mRNA transcript of Ran, Ran-binding protein 2 (RanBP2), Importin-beta and TPX2 in human head and neck cancer cell lines using quantitative real-time PCR. Methods: Total RNA was extracted from cultured primary and metastatic head and neck cancer cell lines prior to converting into cDNA. Quantitative real-time PCR was performed using corresponding cDNA from each cell line. Gene expression data was normalized and relative quantification of gene expression was calculated. Statistical analysis was performed using Student’s T-test (p ≤ 0.05). Results: Preliminary data showed that the level of expression of GTPase Ran in the metastatic head and neck cancer cell line was significantly different from that of the primary head and neck cancer cell line derived from the same patient. Currently, mRNA transcript profiles for RanBP2, Importin-beta and TPX2 are being investigated. Conclusion: Differential expression level of GTPase Ran has been shown for the first time in human head and neck cancer cell lines. Whether Ran is involved in metastatic process of head and neck cancer remains to be investigated. In addition, gene expression profiles of other Ran-related target genes are being studied to uncover a new biomarker for metastatic HNSCC.