AUTHOR=Chen Tzu-Ju , Hsu Bei-Hao , Lee Sung-Wei , Yang Ching-Chieh , Tian Yu-Feng , Kuo Yu-Hsuan , Li Wan-Shan , Tsai Hsin-Hwa , Wu Li-Ching , Yeh Cheng-Fa , Chou Chia-Lin , Lai Hong-Yue 

TITLE=Overexpression of Dehydrogenase/Reductase 9 Predicts Poor Response to Concurrent Chemoradiotherapy and Poor Prognosis in Rectal Cancer Patients

JOURNAL=Pathology and Oncology Research

VOLUME=28

YEAR=2022

URL=https://www.por-journal.com/journals/pathology-and-oncology-research/articles/10.3389/pore.2022.1610537

DOI=10.3389/pore.2022.1610537

ISSN=1532-2807

ABSTRACT=<p><bold>Objective:</bold> To reduce the risk of locoregional recurrence, the addition of neoadjuvant concurrent chemoradiotherapy (CCRT) is recommended before surgical management for rectal cancer patients. However, despite identical tumor histology, individual patient response to neoadjuvant CCRT varies greatly. Accordingly, a comprehensive molecular characterization that is used to predict CCRT efficacy is instantly needed.</p><p><bold>Methods:</bold> Pearson’s chi-squared test was utilized to correlate dehydrogenase/reductase 9 (DHRS9) expression with clinicopathological features. Survival curves were created applying the Kaplan-Meier method, and the log-rank test was conducted to compare prognostic utility between high and low DHRS9 expression groups. Multivariate Cox proportional hazards regression analysis was applied to identify independent prognostic biomarkers based on variables with prognostic utility at the univariate level.</p><p><bold>Results:</bold> Utilizing a public transcriptome dataset, we identified that the <italic>DHRS9</italic> gene is the most considerably upregulated gene related to epithelial cell differentiation (GO: 0030855) among rectal cancer patients with CCRT resistance. Employing immunohistochemical staining, we also demonstrated that high DHRS9 immunoexpression is considerably associated with an aggressive clinical course and CCRT resistance in our rectal cancer cohort. Among all variables with prognostic utility at the univariate level, only high DHRS9 immunoexpression was independently unfavorably prognostic of all three endpoints (all <italic>p</italic> ≤ 0.048) in the multivariate analysis. In addition, applying bioinformatic analysis, we also linked <italic>DHRS9</italic> with unrevealed functions, such as keratan sulfate and mucin synthesis which may be implicated in CCRT resistance.</p><p><bold>Conclusion:</bold> Altogether, <italic>DHRS9</italic> expression may serve as a helpful predictive and prognostic biomarker and assist decision-making for rectal cancer patients who underwent neoadjuvant CCRT.</p>