结直肠癌(CRC)约占所有癌症的10%,年轻年龄组的发病率增加。肠道被认为是独特的器官,具有独特的神经元供应。神经肽,人类甘丙肽,在结肠中广泛分布,并在许多癌症中表达,包括CRC。本研究旨在探讨甘丙肽在CRC不同阶段的作用。招募了81例CRC病例(TNMI-IV期),和福尔马林固定石蜡包埋的样品通过免疫组织化学(IHC)分析甘丙肽和甘丙肽受体1(GALR1)的表达。与其他阶段相比,IV期(n=6)的甘丙肽强度显着降低(使用Mann-WhitneyU检验,p=0.037)。基于通过IHC的甘丙肽表达[早期(n=5)具有高甘丙肽表达和晚期(n=6)具有低甘丙肽表达],对选择的样品使用NGS进行全转录组学分析。五个差异调节途径(使用绝对GSEA)被确定为肿瘤进展的驱动因素,并与更高的甘丙肽表达相关。即,细胞周期,细胞分裂,自噬,TP53的转录调控和免疫系统过程。上调途径中最常见的基因是AURKA,BIRC5,CCNA1,CCNA2,CDC25C,CDK2,CDK6,EREG,LIG3、PIN1、TGFB1、TPX2。使用在四个细胞系[两个原代(HCT116和HT29)和两个转移性(LoVo和SK-Co-1)]上进行的实时PCR来验证结果。目前的研究表明,甘丙肽是一种潜在的阴性生物标志物。甘丙肽下调与晚期CRC分期相关,并与细胞周期和分裂有关。自噬,TP53和免疫系统反应的转录调控。
Colorectal cancer (CRC) represents around 10% of all cancers, with an increasing incidence in the younger age group. The gut is considered a unique organ with its distinctive neuronal supply. The neuropeptide, human galanin, is widely distributed in the colon and expressed in many cancers, including the CRC. The current
study aimed to explore the role of
galanin at different stages of CRC. Eighty-one CRC cases (TNM stages I - IV) were recruited, and formalin-fixed paraffin-embedded samples were analyzed for the expression of galanin and
galanin receptor 1 (GALR1) by immunohistochemistry (IHC).
Galanin intensity was significantly lower in stage IV (n= 6) in comparison to other stages (p= 0.037 using the Mann-Whitney U test). Whole transcriptomics analysis using NGS was performed for selected samples based on the galanin expression by IHC [early (n=5) with high
galanin expression and late (n=6) with low
galanin expression]. Five differentially regulated pathways (using Absolute GSEA) were identified as drivers for tumor progression and associated with higher galanin expression, namely, cell cycle, cell division, autophagy, transcriptional regulation of TP53, and immune system process. The top shared genes among the upregulated pathways are AURKA, BIRC5, CCNA1, CCNA2, CDC25C, CDK2, CDK6, EREG, LIG3, PIN1, TGFB1, TPX2. The results were validated using real-time PCR carried out on four cell lines [two primaries (HCT116 and HT29) and two metastatic (LoVo and SK-Co-1)]. The current
study shows
galanin as a potential negative biomarker. Galanin downregulation is correlated with advanced CRC staging and linked to cell cycle and division, autophagy, transcriptional regulation of TP53 and immune system response.