Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Sci Rep. 2024 May 8;14(1):10539. doi: 10.1038/s41598-024-61000-x.
Abnormal angiogenesis leads to tumor progression and metastasis in colorectal cancer (CRC). This study aimed to elucidate the association between angiogenesis-related genes, including VEGF-A, ANGPT-1, and ANGPT-2 with both metastatic and microsatellite alterations at selected tetranucleotide repeats (EMAST) subtypes of CRC. We conducted a thorough assessment of the ANGPT-1, ANGPT-2, and VEGF-A gene expression utilizing publicly available RNA sequencing and microarray datasets. Then, the experimental validation was performed in 122 CRC patients, considering their disease metastasis and EMAST profile by using reverse transcription polymerase chain reaction (RT-PCR). Subsequently, a competing endogenous RNA (ceRNA) network associated with these angiogenesis-related genes was constructed and analyzed. The expression level of VEGF-A and ANGPT-2 genes were significantly higher in tumor tissues as compared with normal adjacent tissues (P-value < 0.001). Nevertheless, ANGPT-1 had a significantly lower expression in tumor samples than in normal colon tissue (P-value < 0.01). We identified a significantly increased VEGF-A (P-value = 0.002) and decreased ANGPT-1 (P-value = 0.04) expression in EMAST colorectal tumors. Regarding metastasis, a significantly increased VEGF-A and ANGPT-2 expression (P-value = 0.001) and decreased ANGPT-1 expression (P-value < 0.05) were established in metastatic CRC patients. Remarkably, co-expression analysis also showed a strong correlation between ANGPT-2 and VEGF-A gene expressions. The ceRNA network was constructed by ANGPT-1, ANGPT-2, VEGF-A, and experimentally validated miRNAs (hsa-miR-190a-3p, hsa-miR-374c-5p, hsa-miR-452-5p, and hsa-miR-889-3p), lncRNAs (AFAP1-AS1, KCNQ1OT1 and MALAT1), and TFs (Sp1, E2F1, and STAT3). Network analysis revealed that colorectal cancer is amongst the 82 significant pathways. We demonstrated a significant differential expression of VEGF-A and ANGPT-1 in colorectal cancer patients exhibiting the EMAST phenotype. This finding provides novel insights into the molecular pathogenesis of colorectal cancer, specifically in EMAST subtypes. Yet, the generalization of in silico findings to EMAST colorectal cancer warrants future experimental investigations. In the end, this study proposes that the EMAST biomarker could serve as an additional perspective on CMS4 biology which is well-defined by activated angiogenesis and worse overall survival.
异常的血管生成导致结直肠癌（CRC）的肿瘤进展和转移。本研究旨在阐明血管生成相关基因（包括 VEGF-A、ANGPT-1 和 ANGPT-2）与选定的四核苷酸重复（EMAST）CRC 亚型的转移和微卫星改变之间的关联。我们使用公开的 RNA 测序和微阵列数据集对 ANGPT-1、ANGPT-2 和 VEGF-A 基因表达进行了全面评估。然后，通过逆转录聚合酶链反应（RT-PCR）在 122 名 CRC 患者中考虑其疾病转移和 EMAST 谱进行了实验验证。随后，构建并分析了与这些血管生成相关基因相关的竞争内源 RNA（ceRNA）网络。与正常相邻组织相比，VEGF-A 和 ANGPT-2 基因在肿瘤组织中的表达水平显着升高（P 值<0.001）。然而，ANGPT-1 在肿瘤样本中的表达显着低于正常结肠组织（P 值<0.01）。我们发现 EMAST 结直肠肿瘤中 VEGF-A（P 值=0.002）的表达显着增加和 ANGPT-1（P 值=0.04）的表达降低。关于转移，在转移性 CRC 患者中，VEGF-A 和 ANGPT-2 的表达显着增加（P 值=0.001），ANGPT-1 的表达降低（P 值<0.05）。值得注意的是，共表达分析还显示 ANGPT-2 和 VEGF-A 基因表达之间存在很强的相关性。ANGPT-1、ANGPT-2、VEGF-A 和经过实验验证的 miRNAs（hsa-miR-190a-3p、hsa-miR-374c-5p、hsa-miR-452-5p 和 hsa-miR-889-3p）、lncRNAs（AFAP1-AS1、KCNQ1OT1 和 MALAT1）和 TFs（Sp1、E2F1 和 STAT3）构建了 ceRNA 网络。网络分析表明，结直肠癌是 82 个重要途径之一。我们证明了 VEGF-A 和 ANGPT-1 在表现出 EMAST 表型的结直肠癌患者中的差异表达。这一发现为结直肠癌的分子发病机制提供了新的见解，特别是在 EMAST 亚型中。然而，对 EMAST 结直肠癌的计算机模拟结果的推广需要进一步的实验研究。最后，本研究提出 EMAST 生物标志物可以作为 CMS4 生物学的另一个视角，CMS4 生物学由激活的血管生成和更差的总体生存定义。
