背景:IGF2BP3充当RNA结合蛋白(RBP),并在mRNA定位的转录后控制中起作用,稳定性,和翻译。它的失调通常与各种癌症类型的肿瘤发生有关。尽管如此,我们对IGF2BP3基因表达如何调控的理解仍然有限.IGF2BP3的特定功能和潜在机制,以及将其用于膀胱癌治疗目的的潜在益处,还没有很好的理解。
方法:用RT-qPCR和Westernblot检测mRNA和蛋白的表达,分别。通过亚硫酸氢盐测序PCR(BSP)检测CpG位点的甲基化水平。通过荧光素酶报告基因测定分析miR-320a-3p对IGF2BP3表达的调节。通过增殖确定IGF2BP3的功能作用,菌落形成,伤口愈合,入侵检测,和异种移植小鼠模型。通过RNA免疫沉淀(RIP)和mRNA稳定性测定研究IGF2BP3对HMGB1的调节。
结果:我们观察到膀胱癌样本中IGF2BP3水平显著升高,与更高级的阶段和成绩相关,以及不利的预后。随后的研究表明,IGF2BP3表达的上调是由各种肿瘤类型的拷贝数增加/扩增和启动子低甲基化触发的。包括膀胱癌.此外,miR-320a-3p被鉴定为膀胱癌中的另一种负调节因子。功能上,IGF2BP3表达上调加剧了膀胱癌的进展,包括扩散,迁移,和膀胱癌的侵袭。相反,IGF2BP3沉默产生相反的效果。此外,IGF2BP3在膀胱癌中的表达与炎症和免疫浸润呈正相关。机械上,IGF2BP3通过与HMGB1mRNA结合,增强mRNA的稳定性,促进HMGB1的表达,在许多癌症中,这是促进炎症和协调肿瘤发生的因素。重要的是,甘草酸对HMGB1的药理抑制作用,一种特定的HMGB1抑制剂,有效逆转IGF2BP3过表达在膀胱癌中的促癌作用.此外,在哺乳动物胚胎发育中也观察到HMGB1mRNA与IGF2PB3的关系,随着胚胎发育的进展,这两个基因的表达逐渐降低。
结论:我们的研究揭示了控制IGF2BP3表达的遗传和表观遗传机制,强调IGF2BP3-HMGB1轴在驱动膀胱癌进展中的关键参与。此外,它主张研究抑制IGF2BP3-HMGB1作为治疗膀胱癌的可行治疗方法.
BACKGROUND: IGF2BP3 functions as an RNA-binding protein (RBP) and plays a role in the posttranscriptional control of mRNA localization, stability, and translation. Its dysregulation is frequently associated with tumorigenesis across various cancer types. Nonetheless, our understanding of how the expression of the IGF2BP3 gene is regulated remains limited. The specific functions and underlying mechanisms of IGF2BP3, as well as the potential benefits of targeting it for therapeutic purposes in bladder cancer, are not yet well comprehended.
METHODS: The mRNA and protein expression were examined by RT-qPCR and western blotting, respectively. The methylation level of CpG sites was detected by Bisulfite sequencing PCR (BSP). The regulation of IGF2BP3 expression by miR-320a-3p was analyzed by luciferase reporter assay. The functional role of IGF2BP3 was determined through proliferation, colony formation, wound healing, invasion assays, and xenograft mouse model. The regulation of HMGB1 by IGF2BP3 was investigated by RNA immunoprecipitation (RIP) and mRNA stability assays.
RESULTS: We observed a significant elevation in IGF2BP3 levels within bladder cancer samples, correlating with more advanced stages and grades, as well as an unfavorable prognosis. Subsequent investigations revealed that the upregulation of IGF2BP3 expression is triggered by copy number gain/amplification and promoter hypomethylation in various tumor types, including bladder cancer. Furthermore, miR-320a-3p was identified as another negative regulator in bladder cancer. Functionally, the upregulation of IGF2BP3 expression exacerbated bladder cancer progression, including the proliferation, migration, and invasion of bladder cancer. Conversely, IGF2BP3 silencing produced the opposite effects. Moreover, IGF2BP3 expression positively correlated with inflammation and immune infiltration in bladder cancer. Mechanistically, IGF2BP3 enhanced mRNA stability and promoted the expression of HMGB1 by binding to its mRNA, which is a factor that promotes inflammation and orchestrates tumorigenesis in many cancers. Importantly, pharmacological inhibition of HMGB1 with
glycyrrhizin, a specific HMGB1 inhibitor, effectively reversed the cancer-promoting effects of IGF2BP3 overexpression in bladder cancer. Furthermore, the relationship between HMGB1 mRNA and IGF2PB3 is also observed in mammalian embryonic development, with the expression of both genes gradually decreasing as embryonic development progresses.
CONCLUSIONS: Our present study sheds light on the genetic and epigenetic mechanisms governing IGF2BP3 expression, underscoring the critical involvement of the IGF2BP3-HMGB1 axis in driving bladder cancer progression. Additionally, it advocates for the investigation of inhibiting IGF2BP3-HMGB1 as a viable therapeutic approach for treating bladder cancer.