Down-regulated expression of apoptosis-associated genes APIP and UACA in non-small cell lung carcinoma

• Published in: International journal of oncology Vol. 40; no. 6; pp. 2111 - 2121
• Main Authors: MORAVCIKOVA, Erika, KREPELA, Evzen, PROCHAZKA, Jan, ROUSALOVA, Ilona, CERMAK, Jan, BENKOVA, Kamila
• Format: Journal Article
• Language: English
• Published: Athens Editorial Academy of the International Journal of Oncology 01-06-2012
• Subjects: Adult; Aged; Apoptosis - genetics; Apoptosis Regulatory Proteins - genetics; Apoptosis Regulatory Proteins - metabolism; Autoantigens - genetics; Autoantigens - metabolism; Biological and medical sciences; Carcinoma, Non-Small-Cell Lung - metabolism; Carcinoma, Non-Small-Cell Lung - pathology; Cell Line, Tumor; Down-Regulation; Female; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms - metabolism; Lung Neoplasms - pathology; Male; Medical sciences; Middle Aged; Neoplasm Staging; Pneumology; Statistics, Nonparametric; Transcription, Genetic; Tumors; Tumors of the respiratory system and mediastinum; Lung disease; expression; Respiratory disease; Lung cancer; APIP; Malignant tumor; non-small cell lung carcinoma; Gene expression; Apoptotic protease activating factor 1; UACA; nuclear factor-κB; Cancerology; Cell death; Bronchus disease; Apaf-1; Transcription factor NFκB; Cancer; Apoptosis
• ISSN: 1019-6439; 1791-2423
• DOI: 10.3892/ijo.2012.1397

The Apaf-1 interacting protein (APIP) and the uveal autoantigen with coiled coil domains and ankyrin repeats (UACA) belong to endogenous regulators of the apoptosome apparatus, but their role in tumourigenesis and progression of non-small cell lung carcinoma (NSCLC) is not known. Previous studies demonstrated that APIP inhibits the apoptosome-mediated procaspase-9 activation while UACA induces translocation of Apaf-1 from the cytoplasm into the nucleus. Here, we report for the first time that the expression of APIP and UACA genes is down-regulated on the level of both mRNA and protein in NSCLC cells and tumours. In particular, the expression of APIP protein was strikingly decreased and the expression of UACA mRNA and protein was frequently down-regulated in NSCLC tumours of different histopathological types. Moreover, stage IA NSCLC tumours showed significantly lower expression of UACA mRNA compared to higher stage tumours. The weak increase of both APIP and UACA mRNA levels in the 5-aza-2'-deoxycytidine-treated NSCLC cells indicates that mechanisms other than DNA methylation are involved in the regulation of APIP and UACA gene expression in these cancer cells. Taken together, the down-regulation of APIP and UACA expression suggests that the threshold to activate the apoptosome apparatus may be decreased in NSCLC cells due to the lack of APIP-mediated suppression and UACA-assisted Apaf-1 nuclear entry. Moreover, the loss of UACA-assisted Apaf-1 nuclear translocation may underlie the failure of DNA damage checkpoint activation in NSCLC cells leading to their genomic instability.