BACKGROUND Breast cancer(BC) remains a public health problem. Tamoxifen(TAM) resistance has caused great difficulties for treatment of BC patients. Eukaryotic translation initiation factor 4E binding protein 1(EIF4EBP...BACKGROUND Breast cancer(BC) remains a public health problem. Tamoxifen(TAM) resistance has caused great difficulties for treatment of BC patients. Eukaryotic translation initiation factor 4E binding protein 1(EIF4EBP1) plays critical roles in the tumorigenesis and progression of BC. However, the expression and mechanism of EIF4EBP1 in determining the efficacy of TAM therapy in BC patients are still unclear.AIM To investigate the expression and functions of EIF4EBP1 in determining the efficacy of TAM therapy in BC patients.METHODS High-throughput sequencing data of breast tumors were downloaded from the Gene Expression Omnibus database. Differential gene expression analysis identified EIF4EBP1 to be significantly upregulated in cancer tissues. Its prognostic value was analyzed. The biological function and related pathways of EIF4EBP1 was analyzed. Subsequently, the expression of EIF4EBP1 was determined by real-time reverse transcription polymerase chain reaction and western blotting. Cell Counting Kit-8 assays, colony formation assay and wound healing assay were used to understand the phenotypes of function of EIF4EBP1.RESULTS EIF4EBP1 was upregulated in the TAM-resistant cells, and EIF4EBP1 was related to the prognosis of BC patients. Gene Set Enrichment Analysis showed that EIF4EBP1 might be involved in Hedgehog signaling pathways. Decreasing the expression of EIF4EBP1 could reverse TAM resistance, whereas overexpression of EIF4EBP1 promoted TAM resistance.CONCLUSION This study indicated that EIF4EBP1 was overexpressed in the BC and TAM-resistant cell line, which increased cell proliferation, invasion, migration and TAM resistance in BC cells.展开更多
Endocrine therapy(ET)is the therapy backbone of hormone receptor(HR)-positive and human epidermal growth factor receptor 2(HER2)-negati ve advanced breast cancer.However,there are about 20%HR positive patients with no...Endocrine therapy(ET)is the therapy backbone of hormone receptor(HR)-positive and human epidermal growth factor receptor 2(HER2)-negati ve advanced breast cancer.However,there are about 20%HR positive patients with no response to ET due to primary or acquired ET resistance.In this background,many agents have been studied to overcome ET resistance and of which the important agents are cyclin-dependent kinase 4/6(CDK4/6)inhibitors.The prognosis of advanced breast cancer has been improved by combing ET with CDK4/6 inhibitors.In this review,we mainly focused on the CDK4/6 inhibitors in the treatment of HR-positive,HER2-negative advanced breast cancer and discussed the action mechanisms of CDK4/6 inhibitors alone or combined with ET.We also summarized several molecular features that would predict response or resistance to CDK4/6 inhibitors.In addition,we put forward possible strategies to overcome CDK4/6 inhibitor resistance according to the latest research.展开更多
Cyclin-dependent kinase 4 and 6(CDK4/6)inhibitors combined with endocrine therapy have transformed the treatment of estrogen receptor-positive(ER+)and human epidermal growth factor receptor 2 negative(HER2-)metastatic...Cyclin-dependent kinase 4 and 6(CDK4/6)inhibitors combined with endocrine therapy have transformed the treatment of estrogen receptor-positive(ER+)and human epidermal growth factor receptor 2 negative(HER2-)metastatic breast cancer.However,some patients do not respond to this treatment,and patients inevitably develop resistance,such that novel biomarkers are needed to predict primary resistance,monitor treatment response for acquired resistance,and personalize treatment strategies.Circumventing the spatial and temporal limitations of tissue biopsy,newly developed liquid biopsy approaches have the potential to uncover biomarkers that can predict CDK4/6 inhibitor efficacy and resistance in breast cancer patients through a simple blood test.Studies on circulating tumor DNA(ctDNA)-based liquid biopsy biomarkers of CDK4/6 inhibitor resistance have focused primarily on genomic alterations and have failed thus far to identify clear and clinically validated predictive biomarkers,but emerging epigenetic ctDNA methodologies hold promise for further discovery.The present review outlines recent advances and future directions in ctDNA-based biomarkers of CDK4/6 inhibitor treatment response.展开更多
Aim:The study aims to analyze the effect of long-term incubation of ERα-positive MCF7 breast cancer cells with 4-hydroxytamoxifen(HT)on their sensitivity to tubulin polymerization inhibitor docetaxel.Methods:The anal...Aim:The study aims to analyze the effect of long-term incubation of ERα-positive MCF7 breast cancer cells with 4-hydroxytamoxifen(HT)on their sensitivity to tubulin polymerization inhibitor docetaxel.Methods:The analysis of cell viability was performed by the MTT method.The expression of signaling proteins was analyzed by immunoblotting and flow cytometry.ERαactivity was evaluated by gene reporter assay.To establish hormone-resistant subline MCF7,breast cancer cells were treated with 4-hydroxytamoxifen for 12 months.Results:The developed MCF7/HT subline has lost sensitivity to 4-hydroxytamoxifen,and the resistance index was 2.Increased Akt activity(2.2-fold)and decreased ERαexpression(1.5-fold)were revealed in MCF7/HT cells.The activity of the estrogen receptorαwas reduced(1.5-fold)in MCF7/HT.Evaluation of class Ⅲβ-tubulin expression(TUBB3),a marker associated with metastasis,revealed the following trends:higher expression of TUBB3 was detected in triple-negative breast cancer MDA-MB-231 cells compared to hormone-responsive MCF7 cells(P<0.05).The lowest expression of TUBB3 was found in hormone-resistant MCF7/HT cells(MCF7/HT<MCF7<MDA-MB-231,approximately 1:2:4).High TUBB3 expression strongly correlated with docetaxel resistance:IC_(50)value of docetaxel for MDA-MB-231 cells was greater than that for MCF7 cells,whereas resistant MCF7/HT cells were the most sensitive to the drug.The accumulation of cleaved PARP(a 1.6-fold increase)and Bcl-2 downregulation(1.8-fold)were more pronounced in docetaxel-treated resistant cells(P<0.05).The expression of cyclin D1 decreased(2.8-fold)only in resistant cells after 4 nM docetaxel treatment,while this marker was unchanged in parental MCF7 breast cancer cells.Conclusion:Further development of taxane-based chemotherapy for hormone-resistant cancer looks highly promising,especially for cancers with low TUBB3 expression.展开更多
AIM:To test the hypothesis that liver cirrhosis is associated with mobilization of hematopoietic progenitor cells. METHODS:Peripheral blood samples from 72 patients with liver cirrhosis of varying etiology were analyz...AIM:To test the hypothesis that liver cirrhosis is associated with mobilization of hematopoietic progenitor cells. METHODS:Peripheral blood samples from 72 patients with liver cirrhosis of varying etiology were analyzed by flow cytometry.Identified progenitor cell subsets were immunoselected and used for functional assays in vitro. Plasma levels of stromal cell-derived factor-1(SDF-1) were measured using an enzyme linked immunosorbent assay.RESULTS:Progenitor cells with a CD133 + /CD45 + CD14 + phenotype were observed in 61%of th patients.Between 1%and 26%of the peripheral bloo mononuclear cells(MNCs)displayed this phenotype Furthermore,a distinct population of c-kit + progenito cells(between 1%and 38%of the MNCs)could b detected in 91%of the patients.Additionally,18% of the patients showed a population of progenito cells(between 1%and 68%of the MNCs)that wa characterized by expression of breast cancer resistanc protein-1.Further phenotypic analysis disclosed tha the circulating precursors expressed CXC chemokin receptor 4,the receptor for SDF-1.In line with thi finding,elevated plasma levels of SDF-1 were presen in all patients and were found to correlate with th number of mobilized CD133 + progenitor cells.展开更多
内分泌治疗已成为转移性激素受体(hormone receptor,HR)阳性乳腺癌的治疗基础。内分泌耐药的发生使得很多新型内分泌治疗药物或药物组合被研发出来。细胞周期蛋白依赖性激酶(cyclin-dependent protein kinase,CDK)4/6抑制剂的应用可显...内分泌治疗已成为转移性激素受体(hormone receptor,HR)阳性乳腺癌的治疗基础。内分泌耐药的发生使得很多新型内分泌治疗药物或药物组合被研发出来。细胞周期蛋白依赖性激酶(cyclin-dependent protein kinase,CDK)4/6抑制剂的应用可显著延长内分泌耐药患者的无进展生存时间。有多项关于使用磷脂酰肌醇3激酶(phosphatidylinositol 3-kinase,PI3K)抑制剂和哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)抑制剂作为后续治疗方案的研究,特别是针对内分泌耐药的情况,应基于合并症、既往辅助治疗、患者的生活质量、不良反应及无病间隔期的情况,选择治疗方案的最佳顺序。对转移性乳腺癌的特定生物标志物检测以及新型基因检测对预测治疗效果、耐药性以及预后均具有重要意义,有助于进一步推动精准治疗的发展。展开更多
文摘BACKGROUND Breast cancer(BC) remains a public health problem. Tamoxifen(TAM) resistance has caused great difficulties for treatment of BC patients. Eukaryotic translation initiation factor 4E binding protein 1(EIF4EBP1) plays critical roles in the tumorigenesis and progression of BC. However, the expression and mechanism of EIF4EBP1 in determining the efficacy of TAM therapy in BC patients are still unclear.AIM To investigate the expression and functions of EIF4EBP1 in determining the efficacy of TAM therapy in BC patients.METHODS High-throughput sequencing data of breast tumors were downloaded from the Gene Expression Omnibus database. Differential gene expression analysis identified EIF4EBP1 to be significantly upregulated in cancer tissues. Its prognostic value was analyzed. The biological function and related pathways of EIF4EBP1 was analyzed. Subsequently, the expression of EIF4EBP1 was determined by real-time reverse transcription polymerase chain reaction and western blotting. Cell Counting Kit-8 assays, colony formation assay and wound healing assay were used to understand the phenotypes of function of EIF4EBP1.RESULTS EIF4EBP1 was upregulated in the TAM-resistant cells, and EIF4EBP1 was related to the prognosis of BC patients. Gene Set Enrichment Analysis showed that EIF4EBP1 might be involved in Hedgehog signaling pathways. Decreasing the expression of EIF4EBP1 could reverse TAM resistance, whereas overexpression of EIF4EBP1 promoted TAM resistance.CONCLUSION This study indicated that EIF4EBP1 was overexpressed in the BC and TAM-resistant cell line, which increased cell proliferation, invasion, migration and TAM resistance in BC cells.
文摘Endocrine therapy(ET)is the therapy backbone of hormone receptor(HR)-positive and human epidermal growth factor receptor 2(HER2)-negati ve advanced breast cancer.However,there are about 20%HR positive patients with no response to ET due to primary or acquired ET resistance.In this background,many agents have been studied to overcome ET resistance and of which the important agents are cyclin-dependent kinase 4/6(CDK4/6)inhibitors.The prognosis of advanced breast cancer has been improved by combing ET with CDK4/6 inhibitors.In this review,we mainly focused on the CDK4/6 inhibitors in the treatment of HR-positive,HER2-negative advanced breast cancer and discussed the action mechanisms of CDK4/6 inhibitors alone or combined with ET.We also summarized several molecular features that would predict response or resistance to CDK4/6 inhibitors.In addition,we put forward possible strategies to overcome CDK4/6 inhibitor resistance according to the latest research.
文摘Cyclin-dependent kinase 4 and 6(CDK4/6)inhibitors combined with endocrine therapy have transformed the treatment of estrogen receptor-positive(ER+)and human epidermal growth factor receptor 2 negative(HER2-)metastatic breast cancer.However,some patients do not respond to this treatment,and patients inevitably develop resistance,such that novel biomarkers are needed to predict primary resistance,monitor treatment response for acquired resistance,and personalize treatment strategies.Circumventing the spatial and temporal limitations of tissue biopsy,newly developed liquid biopsy approaches have the potential to uncover biomarkers that can predict CDK4/6 inhibitor efficacy and resistance in breast cancer patients through a simple blood test.Studies on circulating tumor DNA(ctDNA)-based liquid biopsy biomarkers of CDK4/6 inhibitor resistance have focused primarily on genomic alterations and have failed thus far to identify clear and clinically validated predictive biomarkers,but emerging epigenetic ctDNA methodologies hold promise for further discovery.The present review outlines recent advances and future directions in ctDNA-based biomarkers of CDK4/6 inhibitor treatment response.
基金supported by the Ministry of Science and Higher Education of the Russian Federation(agreement No.075-15-2020-789).
文摘Aim:The study aims to analyze the effect of long-term incubation of ERα-positive MCF7 breast cancer cells with 4-hydroxytamoxifen(HT)on their sensitivity to tubulin polymerization inhibitor docetaxel.Methods:The analysis of cell viability was performed by the MTT method.The expression of signaling proteins was analyzed by immunoblotting and flow cytometry.ERαactivity was evaluated by gene reporter assay.To establish hormone-resistant subline MCF7,breast cancer cells were treated with 4-hydroxytamoxifen for 12 months.Results:The developed MCF7/HT subline has lost sensitivity to 4-hydroxytamoxifen,and the resistance index was 2.Increased Akt activity(2.2-fold)and decreased ERαexpression(1.5-fold)were revealed in MCF7/HT cells.The activity of the estrogen receptorαwas reduced(1.5-fold)in MCF7/HT.Evaluation of class Ⅲβ-tubulin expression(TUBB3),a marker associated with metastasis,revealed the following trends:higher expression of TUBB3 was detected in triple-negative breast cancer MDA-MB-231 cells compared to hormone-responsive MCF7 cells(P<0.05).The lowest expression of TUBB3 was found in hormone-resistant MCF7/HT cells(MCF7/HT<MCF7<MDA-MB-231,approximately 1:2:4).High TUBB3 expression strongly correlated with docetaxel resistance:IC_(50)value of docetaxel for MDA-MB-231 cells was greater than that for MCF7 cells,whereas resistant MCF7/HT cells were the most sensitive to the drug.The accumulation of cleaved PARP(a 1.6-fold increase)and Bcl-2 downregulation(1.8-fold)were more pronounced in docetaxel-treated resistant cells(P<0.05).The expression of cyclin D1 decreased(2.8-fold)only in resistant cells after 4 nM docetaxel treatment,while this marker was unchanged in parental MCF7 breast cancer cells.Conclusion:Further development of taxane-based chemotherapy for hormone-resistant cancer looks highly promising,especially for cancers with low TUBB3 expression.
基金Supported by Grants from the Erich und Gertrud Roggenbuck Foundation,Hamburg and the Werner Otto Foundation,Hamburg
文摘AIM:To test the hypothesis that liver cirrhosis is associated with mobilization of hematopoietic progenitor cells. METHODS:Peripheral blood samples from 72 patients with liver cirrhosis of varying etiology were analyzed by flow cytometry.Identified progenitor cell subsets were immunoselected and used for functional assays in vitro. Plasma levels of stromal cell-derived factor-1(SDF-1) were measured using an enzyme linked immunosorbent assay.RESULTS:Progenitor cells with a CD133 + /CD45 + CD14 + phenotype were observed in 61%of th patients.Between 1%and 26%of the peripheral bloo mononuclear cells(MNCs)displayed this phenotype Furthermore,a distinct population of c-kit + progenito cells(between 1%and 38%of the MNCs)could b detected in 91%of the patients.Additionally,18% of the patients showed a population of progenito cells(between 1%and 68%of the MNCs)that wa characterized by expression of breast cancer resistanc protein-1.Further phenotypic analysis disclosed tha the circulating precursors expressed CXC chemokin receptor 4,the receptor for SDF-1.In line with thi finding,elevated plasma levels of SDF-1 were presen in all patients and were found to correlate with th number of mobilized CD133 + progenitor cells.
文摘内分泌治疗已成为转移性激素受体(hormone receptor,HR)阳性乳腺癌的治疗基础。内分泌耐药的发生使得很多新型内分泌治疗药物或药物组合被研发出来。细胞周期蛋白依赖性激酶(cyclin-dependent protein kinase,CDK)4/6抑制剂的应用可显著延长内分泌耐药患者的无进展生存时间。有多项关于使用磷脂酰肌醇3激酶(phosphatidylinositol 3-kinase,PI3K)抑制剂和哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)抑制剂作为后续治疗方案的研究,特别是针对内分泌耐药的情况,应基于合并症、既往辅助治疗、患者的生活质量、不良反应及无病间隔期的情况,选择治疗方案的最佳顺序。对转移性乳腺癌的特定生物标志物检测以及新型基因检测对预测治疗效果、耐药性以及预后均具有重要意义,有助于进一步推动精准治疗的发展。
