Lyu Xiaoyue, Qiang Yujie, Zhang Bo, Xu Wei, Cui Yali, Ma Le
College of Life Sciences, Northwest University, Xi'an, China.
Ankang Hospital of Traditional Chinese Medicine, Ankang, Shaanxi, China.
Front Oncol. 2022 Nov 2;12:1016542. doi: 10.3389/fonc.2022.1016542. eCollection 2022.
Approximately 75% of bladder cancer occurrences are of the non-muscle-invasive type. The estimated five-year survival rate is 26%-55%. Currently, there is no reliable biomarker available for early diagnosis and prognosis of bladder cancer. The present study aims to identify a biomarker using bioinformatic approaches to provide a new insight in clinical research for early diagnosis and prognosis of bladder cancer.
Clinical data and a transcriptome of bladder cancer were obtained from TCGA, GEO, GETx, and UCSC Xena. The differential expressed gene (DEG) analysis, weighted gene co-expression network analysis (WGCNA), and survival analysis using the Kaplan-Meier and Cox proportional-hazards models were used to identify the Microtubule-associated Proteins 1A (MAP1A). on overall survival (OS) and disease-free survival (DFS) was analyzed using GEPIA and GETx databases. The TIMER 2.0 database predicted the correlation between MAP1A and immunocytes and immune checkpoints. Target prediction of the regulated competing endogenous RNAs (ceRNAs) network of MAP1A was performed using starBase and TargetScan. Cystoscope v3.7.2 software was used to visualize the ceRNA coexpression network. The R programming language v4.0.2 was applied as an analytic tool. Gene expression of MAP1A verified by RT-qPCR.
The low expression of MAP1A was verified in bladder cancer tissues and bladder cancer cell lines SW780 and 5637. P < 0.001 were obtained by Kaplan-Meier survival analysis and Cox proportional hazards model, with a hazard ratio (HR) of 1.4. Significant correlations between MAP1A and OS (P < 0.001, HR = 1.9) as well as DFS (P < 0.05, HR = 1.7) in bladder cancer were identified through gene expression profiling interactive analysis (GEPIA), indicating MAP1A may be a high-risk factor. Significant correlation in single copy-number variation of MAP1A gene with CD8 T cells, and myeloid dendritic cells (MDCs) (P < 0.05) was noted. MAP1A expression was shown to be significantly correlated with the amount of CD4 T cells and CD8 T cells, MDCs, macrophages, and neutrophils in a statistically significant positive manner (P < 0.001). However, the MAP1A expression demonstrated a strong negative connection with B cells (P < 0.001). Except for macrophage M1 genes IRF5 and PTGS2, MAP1A expression was significantly correlated with the gene levels in immunocytes such as CD4 T cells, CD8 T cells, B cells, dendritic cells (DCs), macrophages, and neutrophils (Cor > 0.2, P < 0.001), as well as immune checkpoint related genes including cytotoxic t-lymphocyte-associated protein 4 (CTLA-4), programmed death 1 (PD-1), programmed death ligand 1 (PD-L1) (P < 0.001). Finally, we predicted that the MAP1A-interacting miRNA was miR-34a-5p, and the MAP1A endogenous competing RNAs were LNC00667, circ_MAP1B, and circ_MYLK, respectively. These findings support the need for further studies on the mechanism underlying the pathogenesis of this disease.
MAP1A is considered as a prospective biomarker for early diagnosis, therapeutic observation, and prognosis analysis in bladder cancer.
大约75%的膀胱癌病例为非肌层浸润性类型。估计五年生存率为26%-55%。目前，尚无可靠的生物标志物可用于膀胱癌的早期诊断和预后评估。本研究旨在利用生物信息学方法鉴定一种生物标志物，为膀胱癌的早期诊断和预后的临床研究提供新的见解。
从TCGA、GEO、GETx和UCSC Xena获取膀胱癌的临床数据和转录组。使用差异表达基因（DEG）分析、加权基因共表达网络分析（WGCNA）以及使用Kaplan-Meier和Cox比例风险模型的生存分析来鉴定微管相关蛋白1A（MAP1A）。使用GEPIA和GETx数据库分析MAP1A对总生存期（OS）和无病生存期（DFS）的影响。TIMER 2.0数据库预测MAP1A与免疫细胞和免疫检查点之间的相关性。使用starBase和TargetScan对MAP1A的调控竞争性内源性RNA（ceRNA）网络进行靶标预测。使用Cystoscope v3.7.2软件可视化ceRNA共表达网络。应用R编程语言v4.0.2作为分析工具。通过RT-qPCR验证MAP1A的基因表达。
在膀胱癌组织以及膀胱癌细胞系SW780和5637中验证了MAP1A的低表达。通过Kaplan-Meier生存分析和Cox比例风险模型得出P<0.001，风险比（HR）为1.4。通过基因表达谱交互分析（GEPIA）确定MAP1A与膀胱癌的OS（P<0.001，HR = 1.9）以及DFS（P<0.05，HR = 1.7）之间存在显著相关性，表明MAP1A可能是一个高危因素。注意到MAP1A基因的单拷贝数变异与CD8 T细胞和髓样树突状细胞（MDCs）之间存在显著相关性（P<0.05）。MAP1A表达与CD4 T细胞、CD8 T细胞、MDCs、巨噬细胞和中性粒细胞的数量呈显著正相关（P<0.001）。然而，MAP1A表达与B细胞呈强烈负相关（P<0.001）。除巨噬细胞M1基因IRF5和PTGS2外，MAP1A表达与CD4 T细胞、CD8 T细胞、B细胞、树突状细胞（DCs）、巨噬细胞和中性粒细胞等免疫细胞中的基因水平以及包括细胞毒性T淋巴细胞相关蛋白4（CTLA-4）、程序性死亡蛋白1（PD-1）、程序性死亡配体1（PD-L1）在内的免疫检查点相关基因均存在显著相关性（Cor>0.2，P<0.001）。最后，我们预测与MAP1A相互作用的miRNA是miR-34a-5p，并且MAP1A的内源性竞争RNA分别是LNC00667、circ_MAP1B和circ_MYLK。这些发现支持对该疾病发病机制的潜在机制进行进一步研究的必要性。
MAP1A被认为是膀胱癌早期诊断、治疗观察和预后分析的一种潜在生物标志物。
