Elevated FAM83A expression predicts poorer clincal outcome in lung adenocarcinoma

Family with sequence similarity 83 member A (FAM83A) can promote tumor cell proliferation and facilitate epidermal growth factor tyrosine kinase inhibitor resistance in some malignant tumors, but its role in lung cancer has not been directly explored. We investigated FAM83A expression in lung adenocarcinoma (LUAD) and its significance in clinicopathologic characteristics and prognosis of the disease. We analyzed the mRNA expression of FAM83A in LUAD and normal (or adjacent) lung tissues from Oncomine database firstly. Then, we detected FAM83A protein expression in five paired fresh LUAD and adjacent lung tissue specimens from patients in our hospital by Western blotting. In addtion, FAM83A expression in 86 paraffin-embedded archived LUAD samples was evaluated by Immunohistochemistry, and the correlations between FAM83A expression and clinicopathologic characteristics and prognosis of the patients were analyzed. Oncomine data analysis manifested that FAM83A mRNA expression was increased in LUAD. Western blotting revealed higher FAM83A expression in fresh LUAD tissues than in the adjacent lung tissues (P= 0.036). Immunohistochemistry analysis on 86 paraffin samples further demonstrated that the LUAD tissue had higher FAM83A expression than adjacent lung tissue (P< 0.001). The correlation analysis revealed that advanced stage tumors (stage III-IV) had higher FAM83A expression than early stage tumors (stage I-II) (P= 0.004). High FAM83A expression was significantly associated with lymphnode involvement and clinical staging (P= 0.008 and 0.008 respectively). Univariate and multivariate Cox regression analysis manifested that FAM83A expression was an independent predictive factor for poor survival. Kaplan-Meier survival curves showed that patients with higher FAM83A expression had shorter overall survival than those with lower FAM83A expressions (P= 0.002). FAM83A is upregulated in advanced LUAD and is related to unfavorible prognosis. FAM83A might be a novel diagnostic and prognositic biomarker for LUAD.