Expression of neuro-oncological ventral antigen-1 in small-cell lung cancer and its value in pathological diagnosis

BACKGROUND: To investigate the expression of neuro-oncological ventral antigen-1 (Nova1) in small-cell lung cancer (SCLC) and its value in clinical pathological diagnosis of SCLCs. METHODS: Nova1 expression in the SCLC cell line H446, lung adenocarcinoma cell line A549, squamous cell carcinoma (SCC) cell line H226 and bronchial epithelial cell line BEAS-2B were examined by RT-PCR. It’s expression in paraffin specimens of 100 SCLC cases, 15 specimens of lung adenocarcinoma cases and 15 specimens of lung SCC cases, as well as adjacent normal tissue was determined by immunohistochemistry. The positive rate of Nova1 in SCLC tissue was compared with those of traditional neuroendocrine markers CD56, Syn and CgA. RESULTS: Nova1 expression in SCLC cell line H446 was significantly higher than that of bronchial epithelial cell line BEAS-2B and lung adenocarcinoma cell line A549 and SCC cell line H226. The positive rate of Nova1 in SCLC tissue was similar to that of CD56 but higher than those of Syn and CgA. Nova1 was neither expressed in the cancer tissue nor in the adjacent normal tissue of the 15 cases of SCC and the 15 cases of adenocarcinoma. In all six cases of combined SCLC, Nova1 was expressed in the SCLC component, whereas markers of SCC or adenocarcinoma were absent. CONCLUSIONS: Nova1 can be used as a novel neuroendocrine marker for pathological diagnosis of SCLC in clinical practice with high sensitivity and specificity, in addition to its role as an independent prognostic marker of overall survival and tumour recurrence, as suggested by previous studies.