Relapse and metastasis are frequent in colon cancer and may be linked to stem cell characteristics.This study isolated side population（SP） cells from a colon cancer cell line（Colo-320） and examined their self-rene...Relapse and metastasis are frequent in colon cancer and may be linked to stem cell characteristics.This study isolated side population（SP） cells from a colon cancer cell line（Colo-320） and examined their self-renewal and differentiation abilities.Compared to non-SP（NSP） cells,SP colon cancer cells were more tumorigenic in vivo and exhibited more invasive characteristics and a greater ability to form colonies.Additionally,more cells were in G0/G1 phase and more highly expressed the multidrug resistance protein BCRP/ABCG2.We achieved enhanced chemotherapy sensitivity by transfecting SP cells with a hairpin-like,small interfering RNA（si RNA） eukaryotic expression plasmid targeting BCRP/ABCG2.展开更多
Breast cancer resistance protein(BCRP)/ATP-binding cassette subfamily G member 2(ABCG2) is an ATP-binding cassette(ABC) transporter identified as a molecular cause of multidrug resistance(MDR) in diverse cancer cells....Breast cancer resistance protein(BCRP)/ATP-binding cassette subfamily G member 2(ABCG2) is an ATP-binding cassette(ABC) transporter identified as a molecular cause of multidrug resistance(MDR) in diverse cancer cells.BCRP physiologically functions as a part of a self-defense mechanism for the organism;it enhances elimination of toxic xenobiotic substances and harmful agents in the gut and biliary tract,as well as through the blood-brain,placental,and possibly blood-testis barriers.BCRP recognizes and transports numerous anticancer drugs including conventional chemotherapeutic and targeted small therapeutic molecules relatively new in clinical use.Thus,BCRP expression in cancer cells directly causes MDR by active efflux of anticancer drugs.Because BCRP is also known to be a stem cell marker,its expression in cancer cells could be a manifestation of metabolic and signaling pathways that confer multiple mechanisms of drug resistance,self-renewal(stemness),and invasiveness(aggressiveness),and thereby impart a poor prognosis.Therefore,blocking BCRP-mediated active efflux may provide a therapeutic benefit for cancers.Delineating the precise molecular mechanisms for BCRP gene expression may lead to identification of a novel molecular target to modulate BCRP-mediated MDR.Current evidence suggests that BCRP gene transcription is regulated by a number of trans-acting elements including hypoxia inducible factor 1α,estrogen receptor,and peroxisome proliferator-activated receptor.Furthermore,alternative promoter usage,demethylation of the BCRP promoter,and histone modification are likely associated with drug-induced BCRP overexpression in cancer cells.Finally,PI3K/AKT signaling may play a critical role in modulating BCRP function under a variety of conditions.These biological events seem involved in a complicated manner.Untangling the events would be an essential first step to developing a method to modulate BCRP function to aid patients with cancer.This review will present a synopsis of the impact of BCRP-mediated MDR in cancer cells,and the molecular mechanisms of acquired MDR currently postulated in a variety of human cancers.展开更多
Metabolic Dysfunction-Associated Steatotic Liver Disease(MASLD)has emerged as a predominant cause of chronic liver disease globally,with its prevalence rising steadily each year.If left untreated,MASLD may progress to...Metabolic Dysfunction-Associated Steatotic Liver Disease(MASLD)has emerged as a predominant cause of chronic liver disease globally,with its prevalence rising steadily each year.If left untreated,MASLD may progress to metabolic dysfunction in associated steatohepatitis(MASH),a more severe condition that can irreversibly advance to liver fibrosis,cirrhosis,and even hepatocyte carcinoma(HCC).Recent studies have illuminated a pivotal link between dysregulated cholesterol metabolism and the pathogenesis and severity of MASLD.This underscores the critical need for a comprehensive exploration of the regulatory mechanisms underlying hepatic cholesterol metabolism in MASLD,as such insights could unveil new therapeutic targets and pave the way for early diagnosis and effective prevention strategies.Cyclocarya paliurus(Batal.)Iljinskaja,a plant known for both medicinal and dietary applications,has demonstrated diverse pharmacological properties,including hypoglycemic,lipid-regulating,and hepatoprotective effects.This study aimed to investigate the hypolipidemic and hepatoprotective activities of Cyclocarya paliurus extract(CCE)in a murine model of MASLD induced by a methionine-choline-deficient(MCD)diet.Simvastatin was employed as a positive control drug,while various doses of CCE were administered to assess its therapeutic potential.Meanwhile,the control and model groups received 0.5%sodium carboxymethyl cellulose(CMC-Na)once daily for 6 weeks.At the end of the treatment period,blood and liver samples were collected for biochemical analysis,histopathological assessment,and gene expression profiling.The findings revealed that CCE significantly reduced serum levels of aspartate aminotransferase(AST)and alanine aminotransferase(ALT)while enhancing the activities of cholinesterase(CHE)and high-density lipoprotein cholesterol(HDL-C).In liver tissues,CCE markedly decreased the levels of total cholesterol(TC)and triglycerides(TG),while simultaneously increasing hepatic HDL-C content.Histological analyses showed notable alleviation of pathological liver damage in CCE-treated mice.Molecular studies further demonstrated that CCE downregulated the expression of key genes and proteins involved in cholesterol synthesis,including SREBP2,LDLR,and HMGCR.Concurrently,it upregulated the expression of genes and proteins related to cholesterol transport,such as ABCG5 and ABCG8.Additionally,CCE mitigated inflammation by improving the expression levels of pro-inflammatory cytokines,including TNF-α and IL-6,and modulated oxidative stress markers,such as NRF2,KEAP1,and NQO1.Protein expression analyses revealed reduced levels of IL-6 and IL-1β,further corroborating its anti-inflammatory effects.In summary,C.paliurus exhibited potent hepatoprotective effects in MCD-induced MASLD mice.These protective mechanisms were closely linked to the upregulation of cholesterol transporters ABCG5/8 and the modulation of sterol regulatory element-binding protein 2(SREBP2).This study highlighted the therapeutic potential of C.paliurus as a promising intervention for MASLD and underscored its role in regulating cholesterol metabolism and mitigating inflammation and oxidative stress.展开更多
背景与目的:三磷酸腺苷结合盒转运体成员ABCG2(ATP-binding cassette superfamily G member2)是源于造血干细胞的标志物之一,其在神经胶质瘤发生发展相关组织和细胞中的表达情况还不清楚。本研究检测ABCG2在不同恶性程度人脑胶质瘤组织...背景与目的:三磷酸腺苷结合盒转运体成员ABCG2(ATP-binding cassette superfamily G member2)是源于造血干细胞的标志物之一,其在神经胶质瘤发生发展相关组织和细胞中的表达情况还不清楚。本研究检测ABCG2在不同恶性程度人脑胶质瘤组织标本、裸小鼠移植瘤标本、体外细胞系球体和胶质瘤干细胞球体中的表达情况并分析其意义。方法:制作布有不同恶性程度人脑胶质瘤组织标本、裸小鼠移植瘤标本、体外细胞系球体和胶质瘤干细胞球体等的组织芯片,用免疫组化方法检测ABCG2在组织芯片中的表达情况。结果:在71例人脑胶质瘤组织标本中ABCG2的阳性率为26.8%,其中Ⅰ级11.1%,Ⅱ级8.0%,Ⅲ级43.5%,Ⅳ级42.9%;Ⅰ～Ⅱ级与Ⅲ～Ⅳ级相比差异具有统计学意义(%2=10.710,P=0.001)。在神经干细胞、裸小鼠移植瘤、胶质瘤干细胞球体表达率为100%。在多种正常组织中亦有不同程度的表达。在胶质瘤临床标本中ABCG2阳性细胞呈亲血管分布。结论:ABCG2在胶质瘤干细胞、恶性程度高的胶质瘤组织标本和移植瘤组织中高表达,并且呈亲血管分布。展开更多
目的:明确结直肠癌组织中ABCG2(ATP-binding cassette superfamily G member 2,ABCG2)的表达及其与患者临床病理特征、以伊立替康(CPT-11)为基础化疗疗效的相关性,从而为结直肠癌患者实现个体化治疗提供理论依据。方法:筛选1996年1月至2...目的:明确结直肠癌组织中ABCG2(ATP-binding cassette superfamily G member 2,ABCG2)的表达及其与患者临床病理特征、以伊立替康(CPT-11)为基础化疗疗效的相关性,从而为结直肠癌患者实现个体化治疗提供理论依据。方法:筛选1996年1月至2011年12月于北京大学肿瘤医院行CPT-11化疗的晚期结直肠癌患者,收集患者完整病史资料及肿瘤组织样本。用免疫组织化学的方法检测样本中ABCG2蛋白表达情况。分析ABCG2蛋白表达与患者临床病理特征、CPT-11化疗疗效的相关性。结果:1)免疫组织化学染色显示ABCG2在结直肠癌组织中表达阳性率达93.2%,癌旁正常肠黏膜ABCG2蛋白阳性表达率为43.6%,癌组织较癌旁正常黏膜组织的表达水平明显增高(P<0.05)。ABCG2表达与患者年龄、性别、病理分化程度、病变部位、肝转移均无明显相关性。2)ABCG2蛋白表达与CPT-11化疗疗效无显著相关(P>0.05)。结论:在应用伊立替康为基础方案化疗的结直肠癌患者中,癌组织中ABCG2蛋白表达水平与患者化疗疗效无明显相关。展开更多
基金supported by grants from the National Nature Science Foundation of China(No.81101870)the National Key Clinical Specialist Construction Programs of China(No.2013-544)the Key Programs of National Health and Family Planning Commission of Tianjin(No.16KG127)
文摘Relapse and metastasis are frequent in colon cancer and may be linked to stem cell characteristics.This study isolated side population（SP） cells from a colon cancer cell line（Colo-320） and examined their self-renewal and differentiation abilities.Compared to non-SP（NSP） cells,SP colon cancer cells were more tumorigenic in vivo and exhibited more invasive characteristics and a greater ability to form colonies.Additionally,more cells were in G0/G1 phase and more highly expressed the multidrug resistance protein BCRP/ABCG2.We achieved enhanced chemotherapy sensitivity by transfecting SP cells with a hairpin-like,small interfering RNA（si RNA） eukaryotic expression plasmid targeting BCRP/ABCG2.
文摘Breast cancer resistance protein(BCRP)/ATP-binding cassette subfamily G member 2(ABCG2) is an ATP-binding cassette(ABC) transporter identified as a molecular cause of multidrug resistance(MDR) in diverse cancer cells.BCRP physiologically functions as a part of a self-defense mechanism for the organism;it enhances elimination of toxic xenobiotic substances and harmful agents in the gut and biliary tract,as well as through the blood-brain,placental,and possibly blood-testis barriers.BCRP recognizes and transports numerous anticancer drugs including conventional chemotherapeutic and targeted small therapeutic molecules relatively new in clinical use.Thus,BCRP expression in cancer cells directly causes MDR by active efflux of anticancer drugs.Because BCRP is also known to be a stem cell marker,its expression in cancer cells could be a manifestation of metabolic and signaling pathways that confer multiple mechanisms of drug resistance,self-renewal(stemness),and invasiveness(aggressiveness),and thereby impart a poor prognosis.Therefore,blocking BCRP-mediated active efflux may provide a therapeutic benefit for cancers.Delineating the precise molecular mechanisms for BCRP gene expression may lead to identification of a novel molecular target to modulate BCRP-mediated MDR.Current evidence suggests that BCRP gene transcription is regulated by a number of trans-acting elements including hypoxia inducible factor 1α,estrogen receptor,and peroxisome proliferator-activated receptor.Furthermore,alternative promoter usage,demethylation of the BCRP promoter,and histone modification are likely associated with drug-induced BCRP overexpression in cancer cells.Finally,PI3K/AKT signaling may play a critical role in modulating BCRP function under a variety of conditions.These biological events seem involved in a complicated manner.Untangling the events would be an essential first step to developing a method to modulate BCRP function to aid patients with cancer.This review will present a synopsis of the impact of BCRP-mediated MDR in cancer cells,and the molecular mechanisms of acquired MDR currently postulated in a variety of human cancers.
基金National Key Research and Development Program of China(Grant No.2022YFC3501700)the Beijing Municipal Natural Science Foundation(Grant No.7144219).
文摘Metabolic Dysfunction-Associated Steatotic Liver Disease(MASLD)has emerged as a predominant cause of chronic liver disease globally,with its prevalence rising steadily each year.If left untreated,MASLD may progress to metabolic dysfunction in associated steatohepatitis(MASH),a more severe condition that can irreversibly advance to liver fibrosis,cirrhosis,and even hepatocyte carcinoma(HCC).Recent studies have illuminated a pivotal link between dysregulated cholesterol metabolism and the pathogenesis and severity of MASLD.This underscores the critical need for a comprehensive exploration of the regulatory mechanisms underlying hepatic cholesterol metabolism in MASLD,as such insights could unveil new therapeutic targets and pave the way for early diagnosis and effective prevention strategies.Cyclocarya paliurus(Batal.)Iljinskaja,a plant known for both medicinal and dietary applications,has demonstrated diverse pharmacological properties,including hypoglycemic,lipid-regulating,and hepatoprotective effects.This study aimed to investigate the hypolipidemic and hepatoprotective activities of Cyclocarya paliurus extract(CCE)in a murine model of MASLD induced by a methionine-choline-deficient(MCD)diet.Simvastatin was employed as a positive control drug,while various doses of CCE were administered to assess its therapeutic potential.Meanwhile,the control and model groups received 0.5%sodium carboxymethyl cellulose(CMC-Na)once daily for 6 weeks.At the end of the treatment period,blood and liver samples were collected for biochemical analysis,histopathological assessment,and gene expression profiling.The findings revealed that CCE significantly reduced serum levels of aspartate aminotransferase(AST)and alanine aminotransferase(ALT)while enhancing the activities of cholinesterase(CHE)and high-density lipoprotein cholesterol(HDL-C).In liver tissues,CCE markedly decreased the levels of total cholesterol(TC)and triglycerides(TG),while simultaneously increasing hepatic HDL-C content.Histological analyses showed notable alleviation of pathological liver damage in CCE-treated mice.Molecular studies further demonstrated that CCE downregulated the expression of key genes and proteins involved in cholesterol synthesis,including SREBP2,LDLR,and HMGCR.Concurrently,it upregulated the expression of genes and proteins related to cholesterol transport,such as ABCG5 and ABCG8.Additionally,CCE mitigated inflammation by improving the expression levels of pro-inflammatory cytokines,including TNF-α and IL-6,and modulated oxidative stress markers,such as NRF2,KEAP1,and NQO1.Protein expression analyses revealed reduced levels of IL-6 and IL-1β,further corroborating its anti-inflammatory effects.In summary,C.paliurus exhibited potent hepatoprotective effects in MCD-induced MASLD mice.These protective mechanisms were closely linked to the upregulation of cholesterol transporters ABCG5/8 and the modulation of sterol regulatory element-binding protein 2(SREBP2).This study highlighted the therapeutic potential of C.paliurus as a promising intervention for MASLD and underscored its role in regulating cholesterol metabolism and mitigating inflammation and oxidative stress.
文摘背景与目的:三磷酸腺苷结合盒转运体成员ABCG2(ATP-binding cassette superfamily G member2)是源于造血干细胞的标志物之一,其在神经胶质瘤发生发展相关组织和细胞中的表达情况还不清楚。本研究检测ABCG2在不同恶性程度人脑胶质瘤组织标本、裸小鼠移植瘤标本、体外细胞系球体和胶质瘤干细胞球体中的表达情况并分析其意义。方法:制作布有不同恶性程度人脑胶质瘤组织标本、裸小鼠移植瘤标本、体外细胞系球体和胶质瘤干细胞球体等的组织芯片,用免疫组化方法检测ABCG2在组织芯片中的表达情况。结果:在71例人脑胶质瘤组织标本中ABCG2的阳性率为26.8%,其中Ⅰ级11.1%,Ⅱ级8.0%,Ⅲ级43.5%,Ⅳ级42.9%;Ⅰ～Ⅱ级与Ⅲ～Ⅳ级相比差异具有统计学意义(%2=10.710,P=0.001)。在神经干细胞、裸小鼠移植瘤、胶质瘤干细胞球体表达率为100%。在多种正常组织中亦有不同程度的表达。在胶质瘤临床标本中ABCG2阳性细胞呈亲血管分布。结论:ABCG2在胶质瘤干细胞、恶性程度高的胶质瘤组织标本和移植瘤组织中高表达,并且呈亲血管分布。
文摘目的:明确结直肠癌组织中ABCG2(ATP-binding cassette superfamily G member 2,ABCG2)的表达及其与患者临床病理特征、以伊立替康(CPT-11)为基础化疗疗效的相关性,从而为结直肠癌患者实现个体化治疗提供理论依据。方法:筛选1996年1月至2011年12月于北京大学肿瘤医院行CPT-11化疗的晚期结直肠癌患者,收集患者完整病史资料及肿瘤组织样本。用免疫组织化学的方法检测样本中ABCG2蛋白表达情况。分析ABCG2蛋白表达与患者临床病理特征、CPT-11化疗疗效的相关性。结果:1)免疫组织化学染色显示ABCG2在结直肠癌组织中表达阳性率达93.2%,癌旁正常肠黏膜ABCG2蛋白阳性表达率为43.6%,癌组织较癌旁正常黏膜组织的表达水平明显增高(P<0.05)。ABCG2表达与患者年龄、性别、病理分化程度、病变部位、肝转移均无明显相关性。2)ABCG2蛋白表达与CPT-11化疗疗效无显著相关(P>0.05)。结论:在应用伊立替康为基础方案化疗的结直肠癌患者中,癌组织中ABCG2蛋白表达水平与患者化疗疗效无明显相关。
