[Objectives]To compare the expression of key factors ATM,CHK2,CDC25A and CDK2 in ATM/CHK2/CDC25A signal pathway in colorectal cancer cell line HCT116 and L-OHP-resistant cell line HCT116/L-OHP,and to explore the relat...[Objectives]To compare the expression of key factors ATM,CHK2,CDC25A and CDK2 in ATM/CHK2/CDC25A signal pathway in colorectal cancer cell line HCT116 and L-OHP-resistant cell line HCT116/L-OHP,and to explore the relationship between ATM/CHK2/CDC25A signal pathway and resistance of colorectal cancer cells to L-OHP.[Methods]RT-qPCR was used to detect the expression of ATM,CHK2,CDC25A and CDK2 mRNA in colorectal cancer cell line HCT116 and L-OHP-resistant cell line HCT116/L-OHP,and Western blot was used to detect the expression of corresponding proteins in these two cell lines.[Results]The expression of ATM,CHK2,CDC25A,CDK2 mRNA and protein in HCT116/L-OHP was significantly higher than that in HCT116.[Conclusions]ATM/CHK2/CDC25A signal pathway was associated with resistance of colorectal cancer cell line HCT116 to L-OHP.Blocking this signal pathway may partially reverse the chemotherapy resistance of colorectal cancer patients with L-OHP resistance.展开更多
Objective To investigate the changes of the cell cycle regulators ATM,Chk2 and p53 and cell cycle arrest in HeLa cells after cisplatin therapy. Methods The proliferation-inhibiting rates of HeLa cells induced by cispl...Objective To investigate the changes of the cell cycle regulators ATM,Chk2 and p53 and cell cycle arrest in HeLa cells after cisplatin therapy. Methods The proliferation-inhibiting rates of HeLa cells induced by cisplatin of different concentrations were measured by MTT assays. The mRNA and protein expressions of ATM,Chk2 and p53 of HeLa cells with and without cisplatin were detected by RT-PCR and Western blot,respectively. The cell cycle analysis was conducted by flow cytometric analysis. Results Cisplatin inhibited the proliferation of HeLa cells in a dose-and time-dependent manner. The mRNA and protein expressions of ATM,Chk2 and p53 were increased in HeLa cells treated with cisplatin. The cell cycle was arrested in G2/M phase in HeLa cells treated with cisplatin. Conclusion Activation of ATM,Chk2 and p53 might be critical in determining whether cells survive or undergo apoptosis. Targeting ATM,Chk2 and p53 pathway might be a promising strategy for reversing chemoresistance to cisplatin in cervical cancer.展开更多
Technologies that measure activation of components of the DNA damage response (DDR) have applications in exposure assessment and personalized medicine. The DDR and associated DNA repair pathways encompass hundreds of ...Technologies that measure activation of components of the DNA damage response (DDR) have applications in exposure assessment and personalized medicine. The DDR and associated DNA repair pathways encompass hundreds of proteins, making detailed measurement of activation technically challenging and laborious. The purpose of our study was to develop protein-specific assays for certain DDR components on a high-throughput electrochemiluminescence (ECL)-based platform. We developed five working assay pairs for ataxia telangiectasia mutated (ATM), checkpoint kinase 2 (CHK2), phosphorylated-ATM S1981, phosphorylated-CHK2 T68 and phosphorylated-tumor protein p53 (p53) S15. We validated the ECL results against traditional immunoblot and γ-H2AX foci measures in cell and cancer models. In an effort to test the ECL-based technology in a clinical setting, we utilized peripheral blood mononuclear cells (PBMCs) from patients undergoing computed tomography (CT) scans. CT scans represent both a valuable medical imaging diagnostic and a controlled environmental exposure to ionizing radiation for research studies, as they deliver ~2 to 31 millisieverts (mSv) and are known to activate DDR components. In this study, we show that ECL-based technology can measure the basal and damage-induced levels of DDR components in patient PBMC samples. Using a blinded study design and patient matched pre- and post CT scan samples, we show that ECL-derived data can consistently (94% of the time, 15/16 patients) identify PBMCs that have been exposed to low dose ionizing radiation associated with CT scans. Ultimately, the results of our pilot clinical study support the idea that ECL-based technology is applicable for use in clinical and population cohorts that study components of the DDR.展开更多
The DNA damage response （DDR） is activated when DNA is altered by intrinsic or extrinsic agents. This pathway is a complex signaling network and plays important roles in genome stability, tumor transformation, and c...The DNA damage response （DDR） is activated when DNA is altered by intrinsic or extrinsic agents. This pathway is a complex signaling network and plays important roles in genome stability, tumor transformation, and cell cycle regulation. Human papillomaviruses （HPVs） are the main etiological agents of cervical cancer. Cervical cancer ranks as the fourth most common cancer among women and the second most frequent cause of cancer-related death worldwide. Over 200 types of HPVs have been identified and about one third of these infect the genital tract. The HPV life cycle is associated with epithelial differentiation. Recent studies have shown that HPVs deregulate the DDR to achieve a productive life cycle. In this review, I summarize current findings about how HPVs mediate the ataxia- telangiectasia mutated kinase （ATM） and the ATM- and RAD3-related kinase （ATR） DDRs, and focus on the roles that ATM and ATR signalings play in HPV viral replication. In addition, I demonstrate that the signal transducer and acti- vator of transcription-5 （STAT）-5, an important immune regulator, can promote ATM and ATR activations through different mechanisms. These findings may provide novel opportunities for development of new therapeutic targets for HPV-related cancers.展开更多
基金the Key Subjects(Pathology and Pathophysiology)at Colleges and Universities of Hebei ProvinceNatural Science Research Project of Chengde Medical University(201830)Science and Technology Research Project of Colleges and Universities in Hebei Province(ZD2020137).
文摘[Objectives]To compare the expression of key factors ATM,CHK2,CDC25A and CDK2 in ATM/CHK2/CDC25A signal pathway in colorectal cancer cell line HCT116 and L-OHP-resistant cell line HCT116/L-OHP,and to explore the relationship between ATM/CHK2/CDC25A signal pathway and resistance of colorectal cancer cells to L-OHP.[Methods]RT-qPCR was used to detect the expression of ATM,CHK2,CDC25A and CDK2 mRNA in colorectal cancer cell line HCT116 and L-OHP-resistant cell line HCT116/L-OHP,and Western blot was used to detect the expression of corresponding proteins in these two cell lines.[Results]The expression of ATM,CHK2,CDC25A,CDK2 mRNA and protein in HCT116/L-OHP was significantly higher than that in HCT116.[Conclusions]ATM/CHK2/CDC25A signal pathway was associated with resistance of colorectal cancer cell line HCT116 to L-OHP.Blocking this signal pathway may partially reverse the chemotherapy resistance of colorectal cancer patients with L-OHP resistance.
文摘Objective To investigate the changes of the cell cycle regulators ATM,Chk2 and p53 and cell cycle arrest in HeLa cells after cisplatin therapy. Methods The proliferation-inhibiting rates of HeLa cells induced by cisplatin of different concentrations were measured by MTT assays. The mRNA and protein expressions of ATM,Chk2 and p53 of HeLa cells with and without cisplatin were detected by RT-PCR and Western blot,respectively. The cell cycle analysis was conducted by flow cytometric analysis. Results Cisplatin inhibited the proliferation of HeLa cells in a dose-and time-dependent manner. The mRNA and protein expressions of ATM,Chk2 and p53 were increased in HeLa cells treated with cisplatin. The cell cycle was arrested in G2/M phase in HeLa cells treated with cisplatin. Conclusion Activation of ATM,Chk2 and p53 might be critical in determining whether cells survive or undergo apoptosis. Targeting ATM,Chk2 and p53 pathway might be a promising strategy for reversing chemoresistance to cisplatin in cervical cancer.
文摘Technologies that measure activation of components of the DNA damage response (DDR) have applications in exposure assessment and personalized medicine. The DDR and associated DNA repair pathways encompass hundreds of proteins, making detailed measurement of activation technically challenging and laborious. The purpose of our study was to develop protein-specific assays for certain DDR components on a high-throughput electrochemiluminescence (ECL)-based platform. We developed five working assay pairs for ataxia telangiectasia mutated (ATM), checkpoint kinase 2 (CHK2), phosphorylated-ATM S1981, phosphorylated-CHK2 T68 and phosphorylated-tumor protein p53 (p53) S15. We validated the ECL results against traditional immunoblot and γ-H2AX foci measures in cell and cancer models. In an effort to test the ECL-based technology in a clinical setting, we utilized peripheral blood mononuclear cells (PBMCs) from patients undergoing computed tomography (CT) scans. CT scans represent both a valuable medical imaging diagnostic and a controlled environmental exposure to ionizing radiation for research studies, as they deliver ~2 to 31 millisieverts (mSv) and are known to activate DDR components. In this study, we show that ECL-based technology can measure the basal and damage-induced levels of DDR components in patient PBMC samples. Using a blinded study design and patient matched pre- and post CT scan samples, we show that ECL-derived data can consistently (94% of the time, 15/16 patients) identify PBMCs that have been exposed to low dose ionizing radiation associated with CT scans. Ultimately, the results of our pilot clinical study support the idea that ECL-based technology is applicable for use in clinical and population cohorts that study components of the DDR.
文摘The DNA damage response （DDR） is activated when DNA is altered by intrinsic or extrinsic agents. This pathway is a complex signaling network and plays important roles in genome stability, tumor transformation, and cell cycle regulation. Human papillomaviruses （HPVs） are the main etiological agents of cervical cancer. Cervical cancer ranks as the fourth most common cancer among women and the second most frequent cause of cancer-related death worldwide. Over 200 types of HPVs have been identified and about one third of these infect the genital tract. The HPV life cycle is associated with epithelial differentiation. Recent studies have shown that HPVs deregulate the DDR to achieve a productive life cycle. In this review, I summarize current findings about how HPVs mediate the ataxia- telangiectasia mutated kinase （ATM） and the ATM- and RAD3-related kinase （ATR） DDRs, and focus on the roles that ATM and ATR signalings play in HPV viral replication. In addition, I demonstrate that the signal transducer and acti- vator of transcription-5 （STAT）-5, an important immune regulator, can promote ATM and ATR activations through different mechanisms. These findings may provide novel opportunities for development of new therapeutic targets for HPV-related cancers.
