ABSTRACT

As a gastrointestinal malignancy, colorectal cancer (CRC) is a main cause of cancer-related deaths worldwide. Mex-3 RNA-binding family member A (MEX3A) is upregulated in multiple types of tumors and plays a critical role in tumor proliferation and metastasis. However, the function of MEX3A in CRC angiogenesis has not been fully understood. Hence, the aim of this study was to explore the role of MEX3A in CRC angiogenesis and investigate its underlying mechanisms. MEX3A expression in CRC was first investigated by bioinformatics means and then measured by qRT-PCR and Western blot. CCK-8 assay was employed to test cell viability. Angiogenesis assay was used to assess angiogenesis. The protein levels of VEGF, FGF and SDF-1 were evaluated using Western blot. The expression levels of MYC, HK2 and PGK1 were investigated by qRT-PCR. Extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) were determined by Seahorse XP 96. The levels of pyruvate, lactate, citric acid and malate were measured by corresponding kits. Bioinformatics analysis demonstrated high MEX3A expression in CRC tissues and MEX3A enrichment in glycolysis and angiogenesis pathways. Cell assays showed high MEX3A expression in CRC cells and its promoting effects in CRC cell proliferation and glycolysis as well as angiogenesis. Rescue experiment confirmed that glycolysis inhibitor 2-DG could offset the promoting effects of MEX3A on the proliferation, angiogenesis and glycolysis of CRC cells. In conclusion, MEX3A could facilitate CRC angiogenesis by activating the glycolytic pathway, suggesting that MEX3A may be a novel therapeutic target for CRC.

摘要

作为胃肠道恶性肿瘤，结直肠癌 (CRC) 是全世界癌症相关死亡的主要原因。Mex-3 RNA 结合家族成员 A (MEX3A) 在多种类型的肿瘤中上调，并在肿瘤增殖和转移中起关键作用。然而，MEX3A 在 CRC 血管生成中的功能尚未完全了解。因此，本研究的目的是探讨 MEX3A 在 CRC 血管生成中的作用并研究其潜在机制。MEX3A 在 CRC 中的表达首先通过生物信息学手段进行研究，然后通过 qRT-PCR 和 Western blot 进行测量。采用CCK-8测定来测试细胞活力。血管生成测定用于评估血管生成。使用蛋白质印迹评估 VEGF、FGF 和 SDF-1 的蛋白质水平。通过 qRT-PCR 研究 MYC、HK2 和 PGK1 的表达水平。细胞外酸化率（ECAR）和耗氧率（OCR）由Seahorse XP 96测定。丙酮酸，乳酸，柠檬酸和苹果酸的水平由相应的试剂盒测量。生物信息学分析表明 MEX3A 在 CRC 组织中高表达，MEX3A 在糖酵解和血管生成途径中富集。细胞测定显示 MEX3A 在 CRC 细胞中的高表达及其在 CRC 细胞增殖和糖酵解以及血管生成中的促进作用。拯救实验证实糖酵解抑制剂2-DG可以抵消MEX3A对CRC细胞增殖、血管生成和糖酵解的促进作用。总之，MEX3A 可以通过激活糖酵解途径促进 CRC 血管生成，表明 MEX3A 可能是 CRC 的新治疗靶点。