Endocrine therapy that blocks estrogen signaling is the most effective treatment for patients with estrogen receptor positive(ER+)breast cancer.However,the efficacy of agents such as tamoxifen(Tam)is often compromised...Endocrine therapy that blocks estrogen signaling is the most effective treatment for patients with estrogen receptor positive(ER+)breast cancer.However,the efficacy of agents such as tamoxifen(Tam)is often compromised by the development of resistance.Here we report that cytokines-activated nuclear IKKαconfers Tam resistance to ER+breast cancer by inducing the expression of FAT10,and that the expression of FAT10 and nuclear IKKαin primary ER+human breast cancer was correlated with lymphotoxinβ(LTB)expression and significantly associated with relapse and metastasis in patients treated with adjuvant mono-Tam.IKKαactivation or enforced FAT10 expression promotes Tam-resistance while loss of IKKαor FAT10 augments Tam sensitivity.The induction of FAT10 by IKKαis mediated by the transcription factor Pax5,and coordinated via an IKKα-p53-miR-23a circuit in which activation of IKKαattenuates p53-directed repression of FAT10.Thus,our findings establish IKKα-to-FAT10 pathway as a new therapeutic target for the treatment of Tam-resistant ER+breast cancer.展开更多
Objective:The novel compound GCJ-490A has been discovered as a pan-histone deacetylase(HDAC)inhibitor that exerts potent inhibitory activity against HDAC1,HDAC3,and HDAC6.Because of the important roles of HDACs in lun...Objective:The novel compound GCJ-490A has been discovered as a pan-histone deacetylase(HDAC)inhibitor that exerts potent inhibitory activity against HDAC1,HDAC3,and HDAC6.Because of the important roles of HDACs in lung cancer development and the high distribution of GCJ-490A in lung tissue,we explored the anti-tumor potency of GCJ-490A against non-small cell lung cancer(NSCLC)in vitro and in vivo in this study.Methods:The in vitro effects of GCJ-490A alone or combined with the EGFR inhibitor gefitinib against NSCLC were measured with proliferation,apoptosis,and colony formation assays.NSCLC xenograft models were used to investigate the efficacy of GCJ-490A combined with gefitinib for the treatment of NSCLC in vivo.Western blot assays,luciferase reporter assays,chromatin immunoprecipitation assays,quantitative real time-PCR,immunohistochemistry,and transcription factor activity assays were used to elucidate possible mechanisms.Results:GCJ-490A effectively inhibited NSCLC cell proliferation and induced apoptosis in vitro and in vivo.Interestingly,inhibition of HDAC1 and HDAC6 by GCJ-490A increased histone acetylation at the IKKαpromoter and enhanced IKKαtranscription,thus decreasing c-Met.Moreover,this c-Met downregulation was found to be essential for the synergistic anti-tumor activity of GCJ-490A and gefitinib.Conclusions:These findings highlight the promising potential of HDAC inhibitors in NSCLC treatment and provide a rational basis for the application of HDAC inhibitors in combination with EGFR inhibitors in clinical trials.展开更多
基金supported by a postdoctoral trainee fellowship from the Frenchman's Creek Women for Cancer Research,a cancer research fellowship from UICC(ACS-10-003)the Natural Science Foundation of China(81974469 and 81672635)the Postgraduate Independent Exploration and Innovation Project of Central South University of China(2019zzts899)。
文摘Endocrine therapy that blocks estrogen signaling is the most effective treatment for patients with estrogen receptor positive(ER+)breast cancer.However,the efficacy of agents such as tamoxifen(Tam)is often compromised by the development of resistance.Here we report that cytokines-activated nuclear IKKαconfers Tam resistance to ER+breast cancer by inducing the expression of FAT10,and that the expression of FAT10 and nuclear IKKαin primary ER+human breast cancer was correlated with lymphotoxinβ(LTB)expression and significantly associated with relapse and metastasis in patients treated with adjuvant mono-Tam.IKKαactivation or enforced FAT10 expression promotes Tam-resistance while loss of IKKαor FAT10 augments Tam sensitivity.The induction of FAT10 by IKKαis mediated by the transcription factor Pax5,and coordinated via an IKKα-p53-miR-23a circuit in which activation of IKKαattenuates p53-directed repression of FAT10.Thus,our findings establish IKKα-to-FAT10 pathway as a new therapeutic target for the treatment of Tam-resistant ER+breast cancer.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.81773763 and 81521005).
文摘Objective:The novel compound GCJ-490A has been discovered as a pan-histone deacetylase(HDAC)inhibitor that exerts potent inhibitory activity against HDAC1,HDAC3,and HDAC6.Because of the important roles of HDACs in lung cancer development and the high distribution of GCJ-490A in lung tissue,we explored the anti-tumor potency of GCJ-490A against non-small cell lung cancer(NSCLC)in vitro and in vivo in this study.Methods:The in vitro effects of GCJ-490A alone or combined with the EGFR inhibitor gefitinib against NSCLC were measured with proliferation,apoptosis,and colony formation assays.NSCLC xenograft models were used to investigate the efficacy of GCJ-490A combined with gefitinib for the treatment of NSCLC in vivo.Western blot assays,luciferase reporter assays,chromatin immunoprecipitation assays,quantitative real time-PCR,immunohistochemistry,and transcription factor activity assays were used to elucidate possible mechanisms.Results:GCJ-490A effectively inhibited NSCLC cell proliferation and induced apoptosis in vitro and in vivo.Interestingly,inhibition of HDAC1 and HDAC6 by GCJ-490A increased histone acetylation at the IKKαpromoter and enhanced IKKαtranscription,thus decreasing c-Met.Moreover,this c-Met downregulation was found to be essential for the synergistic anti-tumor activity of GCJ-490A and gefitinib.Conclusions:These findings highlight the promising potential of HDAC inhibitors in NSCLC treatment and provide a rational basis for the application of HDAC inhibitors in combination with EGFR inhibitors in clinical trials.
