Abstract：
OBJECTIVE: Precancerous metaplasia transition to dysplasia poses a risk for subsequent intestinal-type gastric adenocarcinoma. However, the molecular basis underlying the transformation from metaplastic to cancerous cells remains poorly understood.
METHODS: An integrated analysis of genes associated with metaplasia, dysplasia was conducted, verified and characterised in the gastric tissues of patients by single-cell RNA sequencing and immunostaining. Multiple mouse models, including homozygous conditional knockout Klhl21-floxed mice, were generated to investigate the role of Klhl21 deletion in stemness, DNA damage and tumour formation. Mass-spectrometry-based proteomics and ribosome sequencing were used to elucidate the underlying molecular mechanisms.
RESULTS: Kelch-like protein 21 (KLHL21) expression progressively decreased in metaplasia, dysplasia and cancer. Genetic deletion of Klhl21 enhances the rapid proliferation of Mist1+ cells and their descendant cells. Klhl21 loss during metaplasia facilitates the recruitment of damaged cells into the cell cycle via STAT3 signalling. Increased STAT3 activity was confirmed in cancer cells lacking KLHL21, boosting self-renewal and tumourigenicity. Mechanistically, the loss of KLHL21 promotes PIK3CB mRNA translation by stabilising the PABPC1-eIF4G complex, subsequently causing STAT3 activation. Pharmacological STAT3 inhibition by TTI-101 elicited anticancer effects, effectively impeding the transition from metaplasia to dysplasia. In patients with gastric cancer, low levels of KLHL21 had a shorter survival rate and a worse response to adjuvant chemotherapy.
CONCLUSIONS: Our findings highlighted that KLHL21 loss triggers STAT3 reactivation through PABPC1-mediated PIK3CB translational activation, and targeting STAT3 can reverse preneoplastic metaplasia in KLHL21-deficient stomachs.
METHODS: An integrated analysis of genes associated with metaplasia, dysplasia was conducted, verified and characterised in the gastric tissues of patients by single-cell RNA sequencing and immunostaining. Multiple mouse models, including homozygous conditional knockout Klhl21-floxed mice, were generated to investigate the role of Klhl21 deletion in stemness, DNA damage and tumour formation. Mass-spectrometry-based proteomics and ribosome sequencing were used to elucidate the underlying molecular mechanisms.
RESULTS: Kelch-like protein 21 (KLHL21) expression progressively decreased in metaplasia, dysplasia and cancer. Genetic deletion of Klhl21 enhances the rapid proliferation of Mist1+ cells and their descendant cells. Klhl21 loss during metaplasia facilitates the recruitment of damaged cells into the cell cycle via STAT3 signalling. Increased STAT3 activity was confirmed in cancer cells lacking KLHL21, boosting self-renewal and tumourigenicity. Mechanistically, the loss of KLHL21 promotes PIK3CB mRNA translation by stabilising the PABPC1-eIF4G complex, subsequently causing STAT3 activation. Pharmacological STAT3 inhibition by TTI-101 elicited anticancer effects, effectively impeding the transition from metaplasia to dysplasia. In patients with gastric cancer, low levels of KLHL21 had a shorter survival rate and a worse response to adjuvant chemotherapy.
CONCLUSIONS: Our findings highlighted that KLHL21 loss triggers STAT3 reactivation through PABPC1-mediated PIK3CB translational activation, and targeting STAT3 can reverse preneoplastic metaplasia in KLHL21-deficient stomachs.
摘要：
目的：癌前化生向异型增生的转变对随后的肠型胃腺癌有风险。然而,从化生向癌细胞转化的分子基础仍然知之甚少。
方法：对与化生相关的基因进行综合分析，进行了发育不良，通过单细胞RNA测序和免疫染色在患者的胃组织中验证和表征。多个鼠标模型,包括纯合条件性敲除Klhl21-floxed小鼠，被产生以研究Klhl21缺失在干性中的作用，DNA损伤和肿瘤形成。基于质谱的蛋白质组学和核糖体测序用于阐明潜在的分子机制。
结果：Kelch样蛋白21（KLHL21）在化生中的表达逐渐降低，发育不良和癌症。Klhl21的遗传缺失增强了Mist1细胞及其后代细胞的快速增殖。化生过程中的Klhl21损失有助于通过STAT3信号传导将受损细胞募集到细胞周期中。在缺乏KLHL21的癌细胞中证实了增加的STAT3活性，从而增强了自我更新和致瘤性。机械上,KLHL21的缺失通过稳定PABPC1-eIF4G复合物促进PIK3CBmRNA翻译，随后引起STAT3激活。TTI-101对STAT3的药理学抑制引发了抗癌作用，有效地阻碍了从化生到异型增生的过渡。在胃癌患者中，低水平的KLHL21的生存率较短,对辅助化疗的反应较差.
结论：我们的发现强调KLHL21缺失通过PABPC1介导的PIK3CB翻译激活触发STAT3再激活，靶向STAT3可以逆转KLHL21缺陷型胃的瘤前化生。
方法：对与化生相关的基因进行综合分析，进行了发育不良，通过单细胞RNA测序和免疫染色在患者的胃组织中验证和表征。多个鼠标模型,包括纯合条件性敲除Klhl21-floxed小鼠，被产生以研究Klhl21缺失在干性中的作用，DNA损伤和肿瘤形成。基于质谱的蛋白质组学和核糖体测序用于阐明潜在的分子机制。
结果：Kelch样蛋白21（KLHL21）在化生中的表达逐渐降低，发育不良和癌症。Klhl21的遗传缺失增强了Mist1细胞及其后代细胞的快速增殖。化生过程中的Klhl21损失有助于通过STAT3信号传导将受损细胞募集到细胞周期中。在缺乏KLHL21的癌细胞中证实了增加的STAT3活性，从而增强了自我更新和致瘤性。机械上,KLHL21的缺失通过稳定PABPC1-eIF4G复合物促进PIK3CBmRNA翻译，随后引起STAT3激活。TTI-101对STAT3的药理学抑制引发了抗癌作用，有效地阻碍了从化生到异型增生的过渡。在胃癌患者中，低水平的KLHL21的生存率较短,对辅助化疗的反应较差.
结论：我们的发现强调KLHL21缺失通过PABPC1介导的PIK3CB翻译激活触发STAT3再激活，靶向STAT3可以逆转KLHL21缺陷型胃的瘤前化生。
