Liu Yunze, Xu Lei, Hao Chuanchuan, Wu Jin, Jia Xianhong, Ding Xia, Lin Changwei, Zhu Hongmei, Zhang Yi
Department of Traditional Chinese Medicine, Affiliated Hospital of Xuzhou Medical University, Xuzhou, China.
Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China.
Front Oncol. 2022 May 26;12:866289. doi: 10.3389/fonc.2022.866289. eCollection 2022.
Individual immune-related alternative splicing (AS) events have been found to be significant in immune regulation and cancer prognosis. However, a comprehensive analysis of AS events in cancer cells based on immune-related genes (IRGs) has not been performed, and its clinical value is unknown.
Colon cancer cases with AS data were obtained from TCGA, and then, we identified overall survival-related AS events (OS-ASEs) based on IRGs by univariate analyses. Using Lasso regression, multivariate Cox regression, Kaplan-Meier analysis and nomograms, we constructed an AS risk model based on the calculated risk score. Furthermore, associations of the risk score with clinical and immune features were confirmed through the Wilcoxon rank sum test, association analysis, etc. Finally, by qRT-PCR, cell coculture and CCK-8 analyses, we validated the significance of OS-ASEs in colon cancer cell lines and clinical samples.
A total of 3,119 immune-related AS events and 183 OS-ASEs were identified, and 9 OS-ASEs were ultimately used to construct a comprehensive risk model for colon cancer patients. Low-risk patients had better OS and DFS rates than high risk patients. Furthermore, a high risk score corresponded to high numbers of multiple tumour-infiltrating immune cells and high expression of HLA-D region genes and immune checkpoint genes. Notably, we identified for the first time that anti-PD-L1 or anti-CTLA-4 antibodies may decrease the OS of specific colon cancer patients in the low-risk group. Additionally, the experiment validated that CD46-9652-ES and PSMC5-43011-ES are positively correlated with the infiltration of immune cells and promote the growth of colon cancer cells. CD46-9652-ES can contribute to T cell-mediated tumour cell killing. PSMC5-43011-ES was observed to induce M2 polarization of macrophages.
This study identified and validated immune-related prognostic AS signatures that can be used as a novel AS prognostic model and provide a novel understanding of the relationship between the immune microenvironment and clinical outcomes.
已发现个体免疫相关的可变剪接（AS）事件在免疫调节和癌症预后中具有重要意义。然而，尚未基于免疫相关基因（IRG）对癌细胞中的AS事件进行全面分析，其临床价值也尚不清楚。
从TCGA获取具有AS数据的结肠癌病例，然后通过单变量分析基于IRG识别总生存相关的AS事件（OS-ASE）。使用Lasso回归、多变量Cox回归、Kaplan-Meier分析和列线图，我们基于计算出的风险评分构建了一个AS风险模型。此外，通过Wilcoxon秩和检验、关联分析等证实了风险评分与临床和免疫特征的关联。最后，通过qRT-PCR、细胞共培养和CCK-8分析，我们验证了OS-ASE在结肠癌细胞系和临床样本中的意义。
共识别出3119个免疫相关的AS事件和183个OS-ASE，最终使用9个OS-ASE构建了结肠癌患者的综合风险模型。低风险患者的总生存期（OS）和无病生存期（DFS）率高于高风险患者。此外，高风险评分对应着多种肿瘤浸润免疫细胞数量增加以及HLA-D区域基因和免疫检查点基因的高表达。值得注意的是，我们首次发现抗PD-L1或抗CTLA-4抗体可能会降低低风险组中特定结肠癌患者的OS。此外，实验验证了CD46-9652-ES和PSMC5-43011-ES与免疫细胞浸润呈正相关，并促进结肠癌细胞生长。CD46-9652-ES可促进T细胞介导的肿瘤细胞杀伤。观察到PSMC5-43011-ES可诱导巨噬细胞向M2极化。
本研究识别并验证了免疫相关的预后AS特征，其可作为一种新的AS预后模型，并为免疫微环境与临床结局之间的关系提供了新的认识。
