Increased expression of TUSC3 in non-small cell lung cancer

Aims: To examine the expression of tumor suppressor candidate 3 (TUSC3) in non-small cell lung cancer (NSCLC) compared to adjacent normal tissue, and its correlation with patients' clinicopathological features. Methods: Forty NSCLC patients were recruited, including 30 patients with adenocarcinoma and 10 patients with squamous cell carcinoma. Expression of TUSC3 in tumor tissue and matched normal tissue was determined by real-time PCR and immunohistochemistry (IHC). The epidermal growth factor receptor (EGFR) mutation was detected by amplification refractory mutation system (ARMS)-Scorpions analysis. TUSC3 expression in several NSCLC cell lines was assayed by Western blotting. Results: Expression of TUSC3 is significantly higher in tumors than their adjacent normal tissues in 40 paired NSCLC specimens at both mRNA and protein level (P<0.05). More importantly, increased TUSC3 expression at the mRNA level correlated significantly with gender and age (P<0.05). However, no statistical significance was found between TUSC3 expression and smoking, T status, lymph node metastasis, differentiation and EGFR mutation status at neither mRNA nor protein level (P>0.05). Western analysis detected increased TUSC3 level in several NSCLC cell lines includes A549, H322, H460 and SPC-A1 compared to the control, human bronchial epithelial (HBE) cells. Conclusion: TUSC3 is upregulated in NSCLC tumors compared to adjacent normal tissue, as well as in several NSCLC cell lines, suggesting its potential oncogenic role in NSCLC.