Immune Gene Data-based Molecular Subtyping of Rectal Adenocarcinoma Related to Prognosis

Abstract

Background: The morbidity and mortality of rectal adenocarcinoma (READ) is increasing, which is considered as an aggressive type of colorectal malignancy. A great deal of evidence has suggested the significant association between the progression of READ and the immunophenotype of tumor cells (i.e. the expression of intracellular immune-related genes).Methods: Samples retrieved from the TCGA and ImmPort database were investigated to identify immune-related genes specifically impacting the prognosis of READ patients. Several typical ones were then selected to construct the prognostic prediction model of READ patients through Lasso algorithm. The training and test cohorts were incorporated into the model, respectively. We stratified READ patients to evaluate the accuracy, efficiency and stability of the model in the prediction and classification of patient prognosis according to the value of median RiskScore (Risk-H and Risk-L). GO and KEGG signaling pathway enrichment analysis were conducted among the nine selected immunerelated genes. Results: A total of 57 immune-related displaying marked correlated with patient prognosis were identified and nine most typical genes could be majorly enriched into several pathways with close correlation with READ and the corresponding immune response. the distribution of nine immunerelated genes were examined in the samples from both Risk-H and -L groups. Finally, the connection of the RiskScore value with the clinical characteristics of sample and the related signaling pathways were investigated. Conclusions: The prognostic prediction model of RiskScore constructed based on the expression profiling of the nine immune-associated genes exhibited high prediction accuracy and stability to identify the relevant immune features. This model could contribute to the guidance for clinicians in diagnosing and predicting the prognosis for various immunophenotypes. Meanwhile, it also can offer various therapeutic targets for precise treatment of READ in clinical practice according to the identified immune molecules specific to different subtypes. 14 READ: rectal adenocarcinoma; TCGA: the cancer genome atlas; ROC: Receiver Operating Characteristic Curves; HGNC: hugo gene nomenclature committee; KEGG: Kyoto Encyclopedia of Genes and Genomes.