The prognostic effect of ADH1B and ALDH2in lung adenocarcinoma.

e15167 Background: Alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) are major enzymes involved in the metabolism of carcinogenic acetaldehyde, converting alcohol to acetaldehyde and detoxifying acetaldehyde to harmless acetic acid, respectively. To investigate the role of ADH isoenzymes and ALDH isoenzymes in the development of lung adenocarcinoma (LUAD), we performed a retrospective analysis of gene expression. Methods: RNA sequencing data derived from 497 tumour samples and 54 adjacent normal samples were obtained from the Cancer Genome Atlas (TCGA) database. The transcript levels of ADH and ALDH family genes were compared between tumour tissue and adjacent normal tissue through a Wilcoxon test. The results were validated in transcriptomic data from 111 lung cancer patients available as part of a prior study. The diagnostic and prognostic value of ADH and ALDH family genes was further investigated by survival analysis and nomogram through the TCGA database. Insights into the mechanism of action were gained through gene set enrichment analysis (GSEA). Results: Numerous ADH and ALDH family genes showed nominally significant differential expression between tumour and adjacent normal tissues. The expression levels of ADH1B and ALDH2 showed significant and replicable depression in tumour tissue. Low expression of ADH1B and ALDH2 was associated with worse overall survival, with the combination of these genes providing greater prognostic value than the additive effects of these genes individually in the TCGA database. ADH1B and ALDH2 transcript levels were linked with the regulation of metabolism, cell cycle, DNA repair and cancer-associated pathways. A risk score model for predicting LUAD prognosis was developed and showed good performance in predicting 1, 3 and 5-year overall survival (OS). Consistent with TCGA results, our 111-patient replication dataset showed that the tumour-specific depression was most pronounced for ADH1B, and the lower expression was associated with vascular, pleural and lymphatic invasions. Moreover, smoking status and/or cumulative smoking history do not provide a direct, clinically accessible proxy for tumour ADH1B or ALDH2 expression. Conclusions: The combination of ADH1B and ALDH2 are potential prognostic markers in LUAD and may have utility as an independent clinical factor for evaluating the prognosis of LUAD.