食管鳞状细胞癌（ESCC）发生和发展的机制尚待阐明。本研究旨在调查IGF2BP1过表达在ESCC中的作用和影响。利用免疫组化（IHC）检测ESCC样本中的IGF2BP1蛋白表达，利用TCGA数据集和原位杂交（RISH）分析IGF2BP1和INHBA的mRNA丰度。利用甲基化特异性PCR（MSP-PCR）检测IGF2BP1启动子区域的甲基化水平。进行细胞活力、迁移、侵袭和体内转移实验，探究IGF2BP1过表达在ESCC中的作用。应用RNA免疫沉淀测序（RIP-seq）和质谱法分别鉴定IGF2BP1的靶向RNA和相互作用蛋白。利用RIP-PCR、RNA pull down、免疫荧光（IF）、基因特异性m6A PCR和RNA稳定性实验揭示IGF2BP1失调引起的ESCC细胞恶性表型的分子机制。评估IGF2BP1的小分子抑制剂BTYNB对ESCC细胞的抑制作用。在ESCC组织中检测到IGF2BP1过表达，并与肿瘤浸润深度相关。此外，ESCC细胞中的IGF2BP1 mRNA表达与其启动子甲基化水平呈负相关。IGF2BP1的沉默抑制了ESCC细胞的侵袭和迁移以及肿瘤转移。在机制上，我们观察到IGF2BP1结合并稳定了INHBA mRNA，导致INHBA蛋白表达增加，进而激活Smad2/3信号通路，促进恶性表型的发生。ESCC组织中的INHBA mRNA水平也上调。此外，IGF2BP1与G3BP胁迫颗粒组装因子1（G3BP1）相互作用。G3BP1沉默也下调了INHBA-Smad2/3信号通路。BTYNB抑制了这种激活的信号通路，并显著减轻了ESCC细胞的恶性表型。IGF2BP1的高表达是ESCC组织中的常见事件，可能是该疾病的候选生物标志物。IGF2BP1过表达通过激活INHBA-Smad2/3通路促进ESCC细胞的侵袭和迁移，为高表达IGF2BP1的ESCC患者提供潜在的治疗靶点。© 2023. YUMED Inc.和BioMed Central Ltd.

The mechanisms underlying the occurrence and development of esophageal squamous cell carcinoma (ESCC) remains to be elucidated. The present study aims to investigate the roles and implications of IGF2BP1 overexpression in ESCC.IGF2BP1 protein expression in ESCC samples was assessed by immunohistochemistry (IHC), and the mRNA abundance of IGF2BP1 and INHBA was analyzed with TCGA datasets and by RNA in situ hybridization (RISH). The methylation level of the IGF2BP1 promoter region was detected by methylation-specific PCR (MSP-PCR). Cell viability, migration, invasion and in vivo metastasis assays were performed to explore the roles of IGF2BP1 overexpression in ESCC. RNA immunoprecipitation sequencing (RIP-seq) and mass spectrometry were applied to identify the target RNAs and interacting proteins of IGF2BP1, respectively. RIP-PCR, RNA pulldown, immunofluorescence (IF), gene-specific m6A PCR and RNA stability assays were used to uncover the molecular mechanisms underlying the malignant phenotypes of ESCC cells caused by IGF2BP1 dysregulation. BTYNB, a small molecular inhibitor of IGF2BP1, was evaluated for its inhibitory effect on the malignant phenotypes of ESCC cells.IGF2BP1 overexpression was detected in ESCC tissues and associated with the depth of tumor invasion. In addition, IGF2BP1 mRNA expression in ESCC cells was negatively correlated with the level of its promoter methylation. Knockdown of IGF2BP1 inhibited ESCC cell invasion and migration as well as tumor metastasis. Mechanistically, we observed that IGF2BP1 bound and stabilized INHBA mRNA and then resulted in higher protein expression of INHBA, leading to the activation of Smad2/3 signaling, thus promoting malignant phenotypes. The mRNA level of INHBA was upregulated in ESCC tissues as well. Furthermore, IGF2BP1 interacted with G3BP stress granule assembly factor 1 (G3BP1). Knockdown of G3BP1 also down-regulated the INHBA-Smad2/3 signaling. BTYNB abolished this activated signaling and significantly attenuated the malignant phenotypes of ESCC cells.Elevated expression of IGF2BP1 is a frequent event in ESCC tissues and might be a candidate biomarker for the disease. IGF2BP1 overexpression promotes the invasion and migration of ESCC cells by activating the INHBA-Smad2/3 pathway, providing a potential therapeutic target for ESCC patients with high expression of IGF2BP1.© 2023. YUMED Inc. and BioMed Central Ltd.