Apigenin （4＇,5,7-trihydroxyflavone） is a member of the flavone subclass of flavonoids present in fruits and vegetables. The involvement of autophagy in the apigenin-induced apoptotic death of human breast cancer ce...Apigenin （4＇,5,7-trihydroxyflavone） is a member of the flavone subclass of flavonoids present in fruits and vegetables. The involvement of autophagy in the apigenin-induced apoptotic death of human breast cancer cells was investigated. Cell proliferation and viability were assessed by 3-（4,5-dimethylthiazol- 2-yl）-2,5-diphenyltetrazolium bromide （MTT） and clonogenic assays. Flow cytometry, fluorescent staining and Western blot analysis were employed to detect apoptosis and autophagy, and the role of autophagy was assessed using autophagy inhibitors. Apigenin dose- and time-dependently repressed the proliferation and clonogenic survival of the human breast cancer T47D and MDA-MB-231 cell lines. The death of T47D and MDA-MB-231 cells was due to apoptosis associated with increased levels of Caspase3, PARP cleavage and Bax/Bcl-2 ratios. The results from flow cytometry and fluorescent staining also verified the occurrence of apoptosis. In addition, the apigenin-treated cells exhibited autophagy, as characterized by the appearance of autophagosomes under fluorescence microscopy and the accumulation of acidic vesicular organelles （AVOs） by flow cytometry. Furthermore, the results of the Western blot analysis revealed that the level of LC3-Ⅱ, the processed form of LC3-Ⅰ, was increased. Treatment with the autophagy inhibitor, 3-methyladenine （3-MA）, significantly enhanced the apoptosis induced by apigenin, which was accompanied by an increase in the level of PARP cleavage. Similar results were also confirmed by flow cytometry and fluorescence microscopy. These results indicate that apigenin has apoptosis- and autophagy-inducing effects in breast cancer cells. Autophagy plays a cyto-protective role in apigenin-induced apoptosis, and the combination of apigenin and an autophagy inhibitor may be a promising strategy for breast cancer control.展开更多
Autophagy,the pathway whereby cell components are degraded by lysosomes,is involved in the cell response to environmental stresses,such as nutrient deprivation,hypoxia or exposition to chemotherapeutic agents.Under th...Autophagy,the pathway whereby cell components are degraded by lysosomes,is involved in the cell response to environmental stresses,such as nutrient deprivation,hypoxia or exposition to chemotherapeutic agents.Under these conditions,which are reminiscent of certain phases of tumor development,autophagy either promotes cell survival or induces cell death. This strengthens the possibility that autophagy could be an important target in cancer therapy,as has been proposed.Here,we describe the regulation of survival and death by autophagy and apoptosis,especially in cultured breast cancer cells.In particular,we discuss whether autophagy represents an apoptosis-independent process and/or if they share common pathways. We believe that understanding in detail the molecular mechanisms that underlie the relationships between autophagy and apoptosis in breast cancer cells could improve the available treatments for this disease.展开更多
Aim Recent evidence has revealed that Eukaryotic elongation factor-2 kinase （eEF2K） activity may confer cancer cell adaptation to metabolic stress, and high expression of eEF2K is found in several types of cancer. T...Aim Recent evidence has revealed that Eukaryotic elongation factor-2 kinase （eEF2K） activity may confer cancer cell adaptation to metabolic stress, and high expression of eEF2K is found in several types of cancer. Therefore, eEF2K may contribute to carcinogenesis and represent a promising therapeutic target; however, inhibi- tion of eEF2K for cancer drug discovery still remains in its infancy. This study aimed at developing a series of eEF2K inhibitor as candidate anti-tumor drugs in breast cancer and illustrating the possible mechanisms of its anti- tumor activity in vitro and in vivo. Methods In silico screening, structure modifications, MTT assay and molecular dynamics （MD） simulations were applied for the discovery of the novel eEF2K inhibitor （BL-EKI03）. Observa- tions of cell morphology were executed through several methods including ER-traeker, MDC and Hoeehst 33258 staining and GFP-LC3 transfeetion. Flow eytometrie analyses of MDC and Annexin V/PI were used for quantifica- tion of autophagy and apoptosis ratio. Western blot and ITRAQ analysis were used to explore the detailed mecha- nisms of BL-EKI03-induced ER stress, autophagie death and apoptosis in breast cancer cells. Furthermore, an in vivo xenograft mouse model was established for validating the anti-tumor efficacy of BL-EKI03. Results Firstly, a novel eEF2K inhibitor （BL-EKI03） with a good affinity for eEF2K was eventually discovered after computational screening and synthesis of a series of candidate compounds targeting eEF2K. Subsequently, our results demonstra- ted that BL-EKI03 has remarkable anti-proliferative activities and induces endoplasmie retieulum （ER） stress, au- tophagy and apoptosis in MCF-7 and MDA-MB-436 cells. More importantly, the mechanism for BL-EKI03-indueed autophagie death involves eEF2K-mediated AMPK-mTOR-ULK complex pathways. The proteomies analyses and ex-perimental validation revealed that the BL-EKI03-induced mechanism was also involved BIRC6, BNIP1, SNAP29 and Bif-1, which might be regulated by eEF2K. Moreover, BL-EKI03 exerted its anti-tumor activities without re- markable toxicity, and it also induced autophagy and apoptosis by targeting eEF2K in fifo. Conclusion In this study, a novel eEF2K inhibitor （BL-EKI03） was discovered with remarkable anti-proliferative activities and in- duced endoplasmic reticulum （ER） stress, autophagy and apoptosis of breast cancer in vitro and in fifo. These findings highlight a new small-molecule eEF2K inhibitor （BL-EKI03） that has the potential to impact future breast cancer therapy.展开更多
Limited treatment options are available for aggressive prostate cancer. Gossypol has been reported to have a potent anticancer activity in many types of cancer. It can increase the sensitivity of cancer cells to alkyl...Limited treatment options are available for aggressive prostate cancer. Gossypol has been reported to have a potent anticancer activity in many types of cancer. It can increase the sensitivity of cancer cells to alkylating agents, diminish multidrug resistance and decrease metastasis. Whether or not it can induce autophagy in cancer cells has not yet been determined. Here we investigated the antiproliferative activity of apogossypolone （ApoG2） and （-）-gossypol on the human prostate cancer cell line PC3 and LNCaP in vitro. Exposure of PC-3 and LNCaP cells to ApoG2 resulted in several specific features characteristic of autophagy, including the appearance of membranous vacuoles in the cytoplasm and formation of acidic vesicular organelles. Expression of autophagy-associated LC3-Ⅱ and beclin-1 increased in both cell lines after treatment. Inhibition of autophagy with 3-methyladenine promoted apoptosis of both cell types. Taken together, these data demonstrated that induction of autophagy could represent a defense mechanism against apoptosis in human prostate cancer cells.展开更多
Aim Breast cancer is one of the lethal gynecological malignancy in the world. Tamoxifen （TAM） and fulvestrant （FUL） are the major drugs for patients with estrogen receptor-positive （ER ＋ ） breast cancers. Howev...Aim Breast cancer is one of the lethal gynecological malignancy in the world. Tamoxifen （TAM） and fulvestrant （FUL） are the major drugs for patients with estrogen receptor-positive （ER ＋ ） breast cancers. Howev- er, the development of endocrine resistance is the impediment for successful treatment. In this study, we explored the mechanisms of endocrine resistance and therapeutic strategy for overcoming resistance against TAM and FUL. Methods The experiments were performed in Ell ＋ and estrogen/TAM-sensitive MCF7 cells and antiestrogen-re- sistant MCF7/LCC9 cells. Western blot and confocal microscopy were used to determine cell autophagy. Cell trans- fection and luciferase activity assay were performed to identify the target gene of miR-214. Results It showed that 4-OHT/FUL treatment induced apoptosis as well as autophagy in breast cancer cells. The increase of autophagy might be the major cause of endocrine resistance to 4-OHT or FUL. Mill-214 increased the sensitivity of breast cancer cells to the 4-OHT/FUL-induced apoptosis through inhibition of autophagy. Importantly, a negative correla- tion was established between miR-214 and UCP2 in human breast cancer tissue specimens by RT-qPCR assay. UCP2 was identified to be a direct target of mill-214. Further study in MCF7/LCC9 cells indicated that endocrine resistance might arise from activation of the PI3 K-Akt-mTOll pathway, thereby inducing autophagy by overexpres- sion of UCP2. Conclusions MiR-214 increased the sensitivity of breast cancer cells to TAM and FUL through in- hibition of autophagy by targeting UCP2. Mill-214 shows potential as a novel therapeutic strategy for overcoming endocrine resistance in ER ＋ breast cancers.展开更多
AIM: To investigate the mechanism of action of lipophilic antidepressant fluoxetine(FLX) in representative molecular subtypes of breast cancer.METHODS: The anti-proliferative effects and mechanistic action of FLX in t...AIM: To investigate the mechanism of action of lipophilic antidepressant fluoxetine(FLX) in representative molecular subtypes of breast cancer.METHODS: The anti-proliferative effects and mechanistic action of FLX in triple-negative(SUM149PT) and luminal(T47D and Au565) cancer cells and nontransformed MCF10 A were investigated. Reverse phase protein microarray(RPPM) was performed with and without 10 μmol/L FLX for 24 and 48 h to determine which proteins are significantly changed. Viability and cell cycle analysis were also performed to determine drug effects on cell growth. Western blotting was used to confirm the change in protein expression examined by RPPM or pursue other signaling proteins. RESULTS: The FLX-induced cell growth inhibition in all cell lines was concentration- and time-dependent but less pronounced in early passage MCF10 A. In comparison to the other lines,cell growth reduction in SUM149 PT coincided with significant induction of endoplasmic reticulum(ER) stress and autophagy after 24 and 48 h of 10 μmol/L FLX,resulting in decreased translation of proteins along the receptor tyrosine kinase/Akt/mammalian target of rapamycin pathways. The increase in autophagy marker,cleaved microtubule-associated protein 1 light chain 3,in SUM149 PT after 24 h of FLX was likely due to increased metabolic demands of rapidly dividing cells and ER stress. Consequently,the unfolded protein response mediated by double-stranded RNA-dependent protein kinase-like ER kinase resulted in inhibition of protein synthesis,growth arrest at the G1 phase,autophagy,and caspase-7-mediated cell death.CONCLUSION: Our study suggests a new role for FLX as an inducer of ER stress and autophagy,resulting in death of aggressive triple negative breast cancer SUM149 PT.展开更多
Objective:To investigate the effect of the hexane solvent fraction of Halymenia durvillei(HDHE)on triple-negative breast cancer.Methods:The phytochemical profile of HDHE was investigated by GC-MS.The cytotoxicity of H...Objective:To investigate the effect of the hexane solvent fraction of Halymenia durvillei(HDHE)on triple-negative breast cancer.Methods:The phytochemical profile of HDHE was investigated by GC-MS.The cytotoxicity of HDHE against MDA-MB-231 cells was determined.The apoptotic and autophagic effects of HDHE were analyzed.The expression of molecular markers controlling apoptosis,autophagy,DNA damage,and endoplasmic reticulum(ER)stress was determined.Results:HDHE contains a mixture of fatty acids,mainly hexadecanoic acid.HDHE at a cytotoxic concentration induced apoptotic death of MDA-MB-231 cells through mitochondrial membrane dysfunction,and induction of apoptosis markers,and increased the expression of proteins related to DNA damage response.HDHE also induced the expression of LC-3,a marker of autophagic cell death at a cytotoxic concentration.Moreover,HDHE modulated the expression of ER stress genes.Conclusions:The hexadecanoic acid-enriched extract of Halymenia durvillei promotes apoptosis and autophagy of human triple-negative breast cancer cells.This extract may be further explored as an anticancer agent for triple-negative breast cancer.展开更多
Triple-negative breast cancer is the tumor that lacks expressions of estrogen receptor（ER）, progesterone receptor（PR） and human epidermal growth factor receptor-2（HER2）. A regular chemotherapy cannot eradicate t...Triple-negative breast cancer is the tumor that lacks expressions of estrogen receptor（ER）, progesterone receptor（PR） and human epidermal growth factor receptor-2（HER2）. A regular chemotherapy cannot eradicate triple-negative breast cancer. In the present study, we aimed to develop a combined use of daunorubicin and rofecoxib to treat triple-negative breast cancer, and reveal the underlying mechanisms. A gradient elution HPLC-UV method was developed for quantification, and the evaluations were performed on the triple-negative breast cancer MDA-MB-231 cells using a high content screening system. The results demonstrated that daunorubicin alone was insensitive to the triple negative breast cancer cells, while the combined use of daunorubicin and rofecoxib was able to effectively kill these triple-negative cancer cells, exhibiting a rofecoxib concentration-dependent manner. The mechanism revealed that the augmented anticancer efficacy was associated with direct killing effect, inducing apoptosis and inducing autophagy by the combination treatment. Besides, the apoptosis signaling pathways were correlated to a cascade of reactions by activating apoptotic enzyme caspase family and by suppressing anti-apoptotic gene expressed protein Bcl-2 family. In conclusion, this study provided a fundamental evidence for further developing the combined use of daunorubicin and rofecoxib formulation, hence offering a promising strategy for eradicating the triple negative breast cancer.展开更多
基金supported by the National Natural Science Foundation of China (Grant no. 81001186)the Tianjin Municipal Natural Science Foundation (Grant no. 10JCYBJ C14100,11JCZDJC28000,13JCYBJC21800)
文摘Apigenin （4＇,5,7-trihydroxyflavone） is a member of the flavone subclass of flavonoids present in fruits and vegetables. The involvement of autophagy in the apigenin-induced apoptotic death of human breast cancer cells was investigated. Cell proliferation and viability were assessed by 3-（4,5-dimethylthiazol- 2-yl）-2,5-diphenyltetrazolium bromide （MTT） and clonogenic assays. Flow cytometry, fluorescent staining and Western blot analysis were employed to detect apoptosis and autophagy, and the role of autophagy was assessed using autophagy inhibitors. Apigenin dose- and time-dependently repressed the proliferation and clonogenic survival of the human breast cancer T47D and MDA-MB-231 cell lines. The death of T47D and MDA-MB-231 cells was due to apoptosis associated with increased levels of Caspase3, PARP cleavage and Bax/Bcl-2 ratios. The results from flow cytometry and fluorescent staining also verified the occurrence of apoptosis. In addition, the apigenin-treated cells exhibited autophagy, as characterized by the appearance of autophagosomes under fluorescence microscopy and the accumulation of acidic vesicular organelles （AVOs） by flow cytometry. Furthermore, the results of the Western blot analysis revealed that the level of LC3-Ⅱ, the processed form of LC3-Ⅰ, was increased. Treatment with the autophagy inhibitor, 3-methyladenine （3-MA）, significantly enhanced the apoptosis induced by apigenin, which was accompanied by an increase in the level of PARP cleavage. Similar results were also confirmed by flow cytometry and fluorescence microscopy. These results indicate that apigenin has apoptosis- and autophagy-inducing effects in breast cancer cells. Autophagy plays a cyto-protective role in apigenin-induced apoptosis, and the combination of apigenin and an autophagy inhibitor may be a promising strategy for breast cancer control.
基金Supported by Ministerio de Ciencia e Innovación,Grant No.BFU2008-00186Generalitat Valenciana,No.ACOMP07-187
文摘Autophagy,the pathway whereby cell components are degraded by lysosomes,is involved in the cell response to environmental stresses,such as nutrient deprivation,hypoxia or exposition to chemotherapeutic agents.Under these conditions,which are reminiscent of certain phases of tumor development,autophagy either promotes cell survival or induces cell death. This strengthens the possibility that autophagy could be an important target in cancer therapy,as has been proposed.Here,we describe the regulation of survival and death by autophagy and apoptosis,especially in cultured breast cancer cells.In particular,we discuss whether autophagy represents an apoptosis-independent process and/or if they share common pathways. We believe that understanding in detail the molecular mechanisms that underlie the relationships between autophagy and apoptosis in breast cancer cells could improve the available treatments for this disease.
文摘Aim Recent evidence has revealed that Eukaryotic elongation factor-2 kinase （eEF2K） activity may confer cancer cell adaptation to metabolic stress, and high expression of eEF2K is found in several types of cancer. Therefore, eEF2K may contribute to carcinogenesis and represent a promising therapeutic target; however, inhibi- tion of eEF2K for cancer drug discovery still remains in its infancy. This study aimed at developing a series of eEF2K inhibitor as candidate anti-tumor drugs in breast cancer and illustrating the possible mechanisms of its anti- tumor activity in vitro and in vivo. Methods In silico screening, structure modifications, MTT assay and molecular dynamics （MD） simulations were applied for the discovery of the novel eEF2K inhibitor （BL-EKI03）. Observa- tions of cell morphology were executed through several methods including ER-traeker, MDC and Hoeehst 33258 staining and GFP-LC3 transfeetion. Flow eytometrie analyses of MDC and Annexin V/PI were used for quantifica- tion of autophagy and apoptosis ratio. Western blot and ITRAQ analysis were used to explore the detailed mecha- nisms of BL-EKI03-induced ER stress, autophagie death and apoptosis in breast cancer cells. Furthermore, an in vivo xenograft mouse model was established for validating the anti-tumor efficacy of BL-EKI03. Results Firstly, a novel eEF2K inhibitor （BL-EKI03） with a good affinity for eEF2K was eventually discovered after computational screening and synthesis of a series of candidate compounds targeting eEF2K. Subsequently, our results demonstra- ted that BL-EKI03 has remarkable anti-proliferative activities and induces endoplasmie retieulum （ER） stress, au- tophagy and apoptosis in MCF-7 and MDA-MB-436 cells. More importantly, the mechanism for BL-EKI03-indueed autophagie death involves eEF2K-mediated AMPK-mTOR-ULK complex pathways. The proteomies analyses and ex-perimental validation revealed that the BL-EKI03-induced mechanism was also involved BIRC6, BNIP1, SNAP29 and Bif-1, which might be regulated by eEF2K. Moreover, BL-EKI03 exerted its anti-tumor activities without re- markable toxicity, and it also induced autophagy and apoptosis by targeting eEF2K in fifo. Conclusion In this study, a novel eEF2K inhibitor （BL-EKI03） was discovered with remarkable anti-proliferative activities and in- duced endoplasmic reticulum （ER） stress, autophagy and apoptosis of breast cancer in vitro and in fifo. These findings highlight a new small-molecule eEF2K inhibitor （BL-EKI03） that has the potential to impact future breast cancer therapy.
基金Acknowledgement This study was supported in part by the National Nature Science Foundation of China （No. 30772658, No. 30710403089 and No. 30970712）.
文摘Limited treatment options are available for aggressive prostate cancer. Gossypol has been reported to have a potent anticancer activity in many types of cancer. It can increase the sensitivity of cancer cells to alkylating agents, diminish multidrug resistance and decrease metastasis. Whether or not it can induce autophagy in cancer cells has not yet been determined. Here we investigated the antiproliferative activity of apogossypolone （ApoG2） and （-）-gossypol on the human prostate cancer cell line PC3 and LNCaP in vitro. Exposure of PC-3 and LNCaP cells to ApoG2 resulted in several specific features characteristic of autophagy, including the appearance of membranous vacuoles in the cytoplasm and formation of acidic vesicular organelles. Expression of autophagy-associated LC3-Ⅱ and beclin-1 increased in both cell lines after treatment. Inhibition of autophagy with 3-methyladenine promoted apoptosis of both cell types. Taken together, these data demonstrated that induction of autophagy could represent a defense mechanism against apoptosis in human prostate cancer cells.
文摘Aim Breast cancer is one of the lethal gynecological malignancy in the world. Tamoxifen （TAM） and fulvestrant （FUL） are the major drugs for patients with estrogen receptor-positive （ER ＋ ） breast cancers. Howev- er, the development of endocrine resistance is the impediment for successful treatment. In this study, we explored the mechanisms of endocrine resistance and therapeutic strategy for overcoming resistance against TAM and FUL. Methods The experiments were performed in Ell ＋ and estrogen/TAM-sensitive MCF7 cells and antiestrogen-re- sistant MCF7/LCC9 cells. Western blot and confocal microscopy were used to determine cell autophagy. Cell trans- fection and luciferase activity assay were performed to identify the target gene of miR-214. Results It showed that 4-OHT/FUL treatment induced apoptosis as well as autophagy in breast cancer cells. The increase of autophagy might be the major cause of endocrine resistance to 4-OHT or FUL. Mill-214 increased the sensitivity of breast cancer cells to the 4-OHT/FUL-induced apoptosis through inhibition of autophagy. Importantly, a negative correla- tion was established between miR-214 and UCP2 in human breast cancer tissue specimens by RT-qPCR assay. UCP2 was identified to be a direct target of mill-214. Further study in MCF7/LCC9 cells indicated that endocrine resistance might arise from activation of the PI3 K-Akt-mTOll pathway, thereby inducing autophagy by overexpres- sion of UCP2. Conclusions MiR-214 increased the sensitivity of breast cancer cells to TAM and FUL through in- hibition of autophagy by targeting UCP2. Mill-214 shows potential as a novel therapeutic strategy for overcoming endocrine resistance in ER ＋ breast cancers.
基金Supported by Susan G.Komen for the Cure Career Catalyst in Disparities Research to Ibarra Drendall C(KG090730)Promise Grant to Yu D(KG091020)National Institute of Health to Seewaldt V(R01CA158668)
文摘AIM: To investigate the mechanism of action of lipophilic antidepressant fluoxetine(FLX) in representative molecular subtypes of breast cancer.METHODS: The anti-proliferative effects and mechanistic action of FLX in triple-negative(SUM149PT) and luminal(T47D and Au565) cancer cells and nontransformed MCF10 A were investigated. Reverse phase protein microarray(RPPM) was performed with and without 10 μmol/L FLX for 24 and 48 h to determine which proteins are significantly changed. Viability and cell cycle analysis were also performed to determine drug effects on cell growth. Western blotting was used to confirm the change in protein expression examined by RPPM or pursue other signaling proteins. RESULTS: The FLX-induced cell growth inhibition in all cell lines was concentration- and time-dependent but less pronounced in early passage MCF10 A. In comparison to the other lines,cell growth reduction in SUM149 PT coincided with significant induction of endoplasmic reticulum(ER) stress and autophagy after 24 and 48 h of 10 μmol/L FLX,resulting in decreased translation of proteins along the receptor tyrosine kinase/Akt/mammalian target of rapamycin pathways. The increase in autophagy marker,cleaved microtubule-associated protein 1 light chain 3,in SUM149 PT after 24 h of FLX was likely due to increased metabolic demands of rapidly dividing cells and ER stress. Consequently,the unfolded protein response mediated by double-stranded RNA-dependent protein kinase-like ER kinase resulted in inhibition of protein synthesis,growth arrest at the G1 phase,autophagy,and caspase-7-mediated cell death.CONCLUSION: Our study suggests a new role for FLX as an inducer of ER stress and autophagy,resulting in death of aggressive triple negative breast cancer SUM149 PT.
基金the National Research Council of Thailand to Rapeewan Settacomkul(No.13/2563)Faculty of Medicine,Thammasat University to Kant Sangpairoj(No.2-20/2563).
文摘Objective:To investigate the effect of the hexane solvent fraction of Halymenia durvillei(HDHE)on triple-negative breast cancer.Methods:The phytochemical profile of HDHE was investigated by GC-MS.The cytotoxicity of HDHE against MDA-MB-231 cells was determined.The apoptotic and autophagic effects of HDHE were analyzed.The expression of molecular markers controlling apoptosis,autophagy,DNA damage,and endoplasmic reticulum(ER)stress was determined.Results:HDHE contains a mixture of fatty acids,mainly hexadecanoic acid.HDHE at a cytotoxic concentration induced apoptotic death of MDA-MB-231 cells through mitochondrial membrane dysfunction,and induction of apoptosis markers,and increased the expression of proteins related to DNA damage response.HDHE also induced the expression of LC-3,a marker of autophagic cell death at a cytotoxic concentration.Moreover,HDHE modulated the expression of ER stress genes.Conclusions:The hexadecanoic acid-enriched extract of Halymenia durvillei promotes apoptosis and autophagy of human triple-negative breast cancer cells.This extract may be further explored as an anticancer agent for triple-negative breast cancer.
基金National Natural Science Foundation of China(Grant No.81373343)the Key Grant of Beijing Natural Science Foundation(Grant No.7131009)
文摘Triple-negative breast cancer is the tumor that lacks expressions of estrogen receptor（ER）, progesterone receptor（PR） and human epidermal growth factor receptor-2（HER2）. A regular chemotherapy cannot eradicate triple-negative breast cancer. In the present study, we aimed to develop a combined use of daunorubicin and rofecoxib to treat triple-negative breast cancer, and reveal the underlying mechanisms. A gradient elution HPLC-UV method was developed for quantification, and the evaluations were performed on the triple-negative breast cancer MDA-MB-231 cells using a high content screening system. The results demonstrated that daunorubicin alone was insensitive to the triple negative breast cancer cells, while the combined use of daunorubicin and rofecoxib was able to effectively kill these triple-negative cancer cells, exhibiting a rofecoxib concentration-dependent manner. The mechanism revealed that the augmented anticancer efficacy was associated with direct killing effect, inducing apoptosis and inducing autophagy by the combination treatment. Besides, the apoptosis signaling pathways were correlated to a cascade of reactions by activating apoptotic enzyme caspase family and by suppressing anti-apoptotic gene expressed protein Bcl-2 family. In conclusion, this study provided a fundamental evidence for further developing the combined use of daunorubicin and rofecoxib formulation, hence offering a promising strategy for eradicating the triple negative breast cancer.
