p53免疫组化与TP53突变状态之间的关系一直存在争议。本组研究重新评估p53免疫组化提示TP53突变状态的价值。通过外显子测序,共检测了157例弥漫型胶质瘤（ WHO Ⅱ～Ⅳ级）冷冻组织的TP53基因第4～10外显子。对应所有病例的福尔马林固定...p53免疫组化与TP53突变状态之间的关系一直存在争议。本组研究重新评估p53免疫组化提示TP53突变状态的价值。通过外显子测序,共检测了157例弥漫型胶质瘤（ WHO Ⅱ～Ⅳ级）冷冻组织的TP53基因第4～10外显子。对应所有病例的福尔马林固定石蜡包埋组织检测p53免疫组化（克隆号DO-7）,评估表达强度和比率。66例突变病例中发现72个突变,包括60个错义突变,5个无义突变,4个缺失和3个剪切位点变异。通过 ROC曲线分析发现大于10%的肿瘤细胞强阳性可最大程度地提示突变。展开更多
Objective The nucleolar protein PES1(Pescadillo homolog 1)plays critical roles in ribosome biogenesis and cell cycle regulation,yet its involvement in cellular senescence remains poorly understood.This study aimed to ...Objective The nucleolar protein PES1(Pescadillo homolog 1)plays critical roles in ribosome biogenesis and cell cycle regulation,yet its involvement in cellular senescence remains poorly understood.This study aimed to comprehensively investigate the functional consequences of PES1 suppression in cellular senescence and elucidate the molecular mechanisms underlying its regulatory role.Methods Initially,we assessed PES1 expression patterns in two distinct senescence models:replicative senescent mouse embryonic fibroblasts(MEFs)and doxorubicin-induced senescent human hepatocellular carcinoma HepG2 cells.Subsequently,PES1 expression was specifically downregulated using siRNA-mediated knockdown in these cell lines as well as additional relevant cell types.Cellular proliferation and senescence were assessed by EdU incorporation and SA-β-gal staining assays,respectively.The expression of senescence-associated proteins(p53,p21,and Rb)and SASP factors(IL-6,IL-1β,and IL-8)were analyzed by Western blot or qPCR.Furthermore,Northern blot and immunofluorescence were employed to evaluate pre-rRNA processing and nucleolar morphology.Results PES1 expression was significantly downregulated in senescent MEFs and HepG2 cells.PES1 knockdown resulted in decreased EdU-positive cells and increased SA-β-gal-positive cells,indicating proliferation inhibition and senescence induction.Mechanistically,PES1 suppression activated the p53-p21 pathway without affecting Rb expression,while upregulating IL-6,IL-1β,and IL-8 production.Notably,PES1 depletion impaired pre-rRNA maturation and induced nucleolar stress,as evidenced by aberrant nucleolar morphology.Conclusion Our findings demonstrate that PES1 deficiency triggers nucleolar stress and promotes p53-dependent(but Rb-independent)cellular senescence,highlighting its crucial role in maintaining nucleolar homeostasis and regulating senescence-associated pathways.展开更多
文摘p53免疫组化与TP53突变状态之间的关系一直存在争议。本组研究重新评估p53免疫组化提示TP53突变状态的价值。通过外显子测序,共检测了157例弥漫型胶质瘤（ WHO Ⅱ～Ⅳ级）冷冻组织的TP53基因第4～10外显子。对应所有病例的福尔马林固定石蜡包埋组织检测p53免疫组化（克隆号DO-7）,评估表达强度和比率。66例突变病例中发现72个突变,包括60个错义突变,5个无义突变,4个缺失和3个剪切位点变异。通过 ROC曲线分析发现大于10%的肿瘤细胞强阳性可最大程度地提示突变。
文摘Objective The nucleolar protein PES1(Pescadillo homolog 1)plays critical roles in ribosome biogenesis and cell cycle regulation,yet its involvement in cellular senescence remains poorly understood.This study aimed to comprehensively investigate the functional consequences of PES1 suppression in cellular senescence and elucidate the molecular mechanisms underlying its regulatory role.Methods Initially,we assessed PES1 expression patterns in two distinct senescence models:replicative senescent mouse embryonic fibroblasts(MEFs)and doxorubicin-induced senescent human hepatocellular carcinoma HepG2 cells.Subsequently,PES1 expression was specifically downregulated using siRNA-mediated knockdown in these cell lines as well as additional relevant cell types.Cellular proliferation and senescence were assessed by EdU incorporation and SA-β-gal staining assays,respectively.The expression of senescence-associated proteins(p53,p21,and Rb)and SASP factors(IL-6,IL-1β,and IL-8)were analyzed by Western blot or qPCR.Furthermore,Northern blot and immunofluorescence were employed to evaluate pre-rRNA processing and nucleolar morphology.Results PES1 expression was significantly downregulated in senescent MEFs and HepG2 cells.PES1 knockdown resulted in decreased EdU-positive cells and increased SA-β-gal-positive cells,indicating proliferation inhibition and senescence induction.Mechanistically,PES1 suppression activated the p53-p21 pathway without affecting Rb expression,while upregulating IL-6,IL-1β,and IL-8 production.Notably,PES1 depletion impaired pre-rRNA maturation and induced nucleolar stress,as evidenced by aberrant nucleolar morphology.Conclusion Our findings demonstrate that PES1 deficiency triggers nucleolar stress and promotes p53-dependent(but Rb-independent)cellular senescence,highlighting its crucial role in maintaining nucleolar homeostasis and regulating senescence-associated pathways.
