We have reported that norcantharidin (NCTD) induces human melanoma A375-S2cell apoptosis and that the activation of caspase and the mitochondrial pathway are involved in theapoptotic process. This study aimed at inves...We have reported that norcantharidin (NCTD) induces human melanoma A375-S2cell apoptosis and that the activation of caspase and the mitochondrial pathway are involved in theapoptotic process. This study aimed at investigating the roles of mitogen-activated protein kinase(MAPK) and protein kinase C (PKC) in A375-S2 cell apoptosis induced by NCTD. We assessed theeffects of NCTD on cell growth inhibition using the 3-(4,5-dimethylthiazol-2-yl)-2 ,5-dipheyltetrazolium bromide ( MTT) assay, DNA fragmentation ( DNA agarose gel electrophoresis ) ,and MAPK protein levels (Western blot analysis) in A375-S2 cells. Photomicroscopic data were alsocollected. The NCTD inhibitory effect on A375-S2 cells was partially reversed by MAPK and PKCinhibitors. The expression of phosphorylated JNK and p38 also increased after the treatment withNCTD, and inhibitors of c-Jun NH2 - terminal kinase (JNK) and p38 ( SP600125 and SB203580,respectively) had significant inhibitory effects on the upregulation of phosphorylated JNK and p38expression. Simultaneously, the PKC inhibitor staurosporine blocked the upregulation ofphosphorylated JNK and phosphorylated p_(38), but had little effect on extracellularsignal-regulated kinase (ERK) expression. These results suggest that the activation of JNK andp_(38) MAPK promotes the process of NCTD-induced A375-S2 cell apoptosis and that PKC plays animportant regulation role in the activation of MAPKs.展开更多
Lung cancer is one of the malignant tumors with the fastest increase in morbidity and mortality and the greatest threat to people’s health and life.Worldwide,lung cancer is the leading cause of cancer death in men an...Lung cancer is one of the malignant tumors with the fastest increase in morbidity and mortality and the greatest threat to people’s health and life.Worldwide,lung cancer is the leading cause of cancer death in men and the second leading cause of cancer deaths in women[1].Lung cancer is divided into two major groups,small cell lung cancer(SCLC)and non-small cell lung cancer(NSCLC)[2].SCLC accounts for approximately 20%of lung cancers.It has a high degree of malignancy and early metastasis,and is sensitive to chemotherapy and radiotherapy.The initial remission rate is high,but it is prone to secondary drug resistance and relapse.Chemotherapy is the mainstay.NSCLC includes three major histological subtypes,lung squamous cell carcinoma(SCC),lung adenocarcinoma(ADC),and large cell lung cancer(LCLC),accounting for approximately 80%of lung cancers.Cell division is slower,and the diffusion shift is relatively late[3].Nevertheless,while current research on the biological characteristics of different histological subtypes of NSCLC is expanding,its basic molecular mechanism is not yet clear.For example,smoking is more risky for SCC than ADC[4].Micro-RNA is an endogenous small RNA with a length of approximately 19–25 nucleotides.As a short non-coding RNA,its main function is to regulate the expression level of mRNA.miRNAs can be used as proto-oncogenes or tumor suppressors,and participate in various processes including proliferation,apoptosis,metabolism,and differentiation of cells through targeted binding to different transcripts[5].miRNAs are expressed in specific tissue and developmental stages under normal physiological conditions,but abnormal expression of miRNAs can lead to a series of pathological states,such as tumorigenesis and metastasis[6–7].miRNA regulates the function of tumor cells by regulating the expression of functional proteins.For example,miR-206 promotes breast cancer proliferation by inhibiting estrogen receptor alpha(ERα)while miR-34a downregulates E2 factor transcription factor 2(E2F2)expression to regulate the cell cycle and apoptosis[8–9].CIP2A,as an oncogenic protein during the malignant transformation and progression of cancer cells,has been shown to have a certain relationship with the efficacy of many drugs in cancer treatment.Oncoprotein CIP2A,also known as KIAA1524 or P90,was named in 2007 and is a cancerous inhibitor of PP2A due to its effect on cancer cells.The stability of PP2A and MYC is controlled to form a"carcinogenic connection"[10].In this study,we found that miR-375 regulated the expression of downstream protein kinase B(AKT),MYC,p-AKT and other related proteins through the CIP2A/PP2A signaling pathway,inhibiting the cancer phenotype of lung cancer,and affecting cell invasion,proliferation,apoptosis,and the cell morphology process.We found that the CIP2A gene is a direct binding target of miR-375.Thus,it has become a topic of great interest to explore whether and how miR-375 regulates ADC cells through the CIP2A signaling pathway.By up-regulating miR-375 in a lentivirus-transfected A549 cell line,we found that a series of phenotypes,including cell invasion,proliferation,and apoptosis were changed,and that CIP2A and its downstream signaling proteins were also changed.展开更多
Objective: To investigate the effects of histamine on growth and apoptosis of human melanoma cells A375. Methods: The effect of histamine on growth of A375 cells in vitro was examined by MTT assay and Trypan blue excl...Objective: To investigate the effects of histamine on growth and apoptosis of human melanoma cells A375. Methods: The effect of histamine on growth of A375 cells in vitro was examined by MTT assay and Trypan blue exclusion assay. Cell cycle analysis, early apoptosis analysis by double staining with Annexin V-FITC and PI, and active caspase-3 analysis by staining FITC-conjugated monoclonal rabbit anti-active caspase-3 antibody were made by flow cytometer. StreptAvidin-Biotin Complex (SABC) immunocytochemical assays were adopted to detect Bax/Bcl-2 protein expressions.Results: Histamine inhibited proliferation of A375 cells in a dose- and time-dependent manner, and altered cell cycle distribution of A375 cells revealing an increase in G0/G1-phase population, a decrease in S-phase population and the inhibition of G1/S switching. Histamine induced apoptosis of A375 cells (P<0.05), elevated the cells population with detectable active caspase-3 (P<0.05), increased the number of cells forming Bax and decreased the number of cells forming Bcl-2 significantly (P<0.05). Conclusion: That histamine inhibits cell cycle progress of A375 cells is one of the possible mechanisms of proliferation arrest of A375 cells elicited by histamine. Histamine mediates apoptosis in A375 cells that may be caspase-dependent through mitochondria routine. Histamine with high concentration inhibits growth of A375 cells in vitro by interfering proliferation and inducing apoptosis of cells.展开更多
Objective： To study apoptotic effects of synthetic retinoic acid 6-[3-（1-adamantyl）-4-hydroxyphenyl]-2-naphthalene carboxylic acid（AHPN） on human skin malignant melanoma A375 cells in comparison with the natural ...Objective： To study apoptotic effects of synthetic retinoic acid 6-[3-（1-adamantyl）-4-hydroxyphenyl]-2-naphthalene carboxylic acid（AHPN） on human skin malignant melanoma A375 cells in comparison with the natural ligand all-trans-retinoic acid（ATRA） in vitro and the mechanisms related to the actions of AHPN. Methods：MTT assay was used to determine the anti-proliferative effects of AHPN and ATRA on A375 cells. Flow cytometry was performed to investigate the influence of AHPN and ATRA on cell cycle and cell apoptosis. In addition, transfection and luciferase activity assays were employed to explore the mechanisms of how AHPN executes its proapoptotic function. Results：Firstly, AHPN promoted apoptosis and GI arrest in A375 cells compared with ATRA. Secondly, the activity of NF-K B in A375 cells treated with AHPN increased 2-3 times compared with solvent DMSO treatment. Conclusion：AHPN, in comparison with ATRA, is a more effective alternative for therapy of malignant melanoma. The potentially proapoptotic function of AHPN requires activation of NF-K B.展开更多
Objective： To investigate the effects of synthetic retinoid CD437 and acitretin on cell proliferation, apoptosis, cycle arrest and Bax/ Bcl-2 protein expression of melanoma A375 cell, Methods：MTT assay was used to d...Objective： To investigate the effects of synthetic retinoid CD437 and acitretin on cell proliferation, apoptosis, cycle arrest and Bax/ Bcl-2 protein expression of melanoma A375 cell, Methods：MTT assay was used to determine the anti-proliferative effects of CD437 and acitretin on melanoma A375 cell, Flow cytometry was performed to investigate the influence of CD437 and acitretin on cell cycle and cell apoptosis. SABC immunocytochemistry was employed for detection of Bax/bcl-2 protein expressions. Results：10^-5 mol/L CD437 was more effective than acitretin in inhibiting proliferation and inducing apoptosis of A375 cell after 24 h treatment, growth inhibiting ratio and apoptosis ratio（58.6%vs43.25% and 28.03%vs17.13%, P 〈 0.05 respectively）. CD437 promoted G0/G1 arrest in melanoma A375 cell, however acitretin could not. CD437 and acitretin could up-regulate the expression of Bax protein and downregulate the expression of bcl-2 protein（P 〈 0.05）. Conclusion：CD437 is more effective than acitretin in inhibiting proliferation and inducing apoptosis and cycle arrest on A375 cell, CD437 may have more potentialities than acitretin for subsidiary treatment of melanoma. Mitochondrial apoptosis pathway is partially involved in two drugs inducing apoptosis on A375 cell.展开更多
文摘We have reported that norcantharidin (NCTD) induces human melanoma A375-S2cell apoptosis and that the activation of caspase and the mitochondrial pathway are involved in theapoptotic process. This study aimed at investigating the roles of mitogen-activated protein kinase(MAPK) and protein kinase C (PKC) in A375-S2 cell apoptosis induced by NCTD. We assessed theeffects of NCTD on cell growth inhibition using the 3-(4,5-dimethylthiazol-2-yl)-2 ,5-dipheyltetrazolium bromide ( MTT) assay, DNA fragmentation ( DNA agarose gel electrophoresis ) ,and MAPK protein levels (Western blot analysis) in A375-S2 cells. Photomicroscopic data were alsocollected. The NCTD inhibitory effect on A375-S2 cells was partially reversed by MAPK and PKCinhibitors. The expression of phosphorylated JNK and p38 also increased after the treatment withNCTD, and inhibitors of c-Jun NH2 - terminal kinase (JNK) and p38 ( SP600125 and SB203580,respectively) had significant inhibitory effects on the upregulation of phosphorylated JNK and p38expression. Simultaneously, the PKC inhibitor staurosporine blocked the upregulation ofphosphorylated JNK and phosphorylated p_(38), but had little effect on extracellularsignal-regulated kinase (ERK) expression. These results suggest that the activation of JNK andp_(38) MAPK promotes the process of NCTD-induced A375-S2 cell apoptosis and that PKC plays animportant regulation role in the activation of MAPKs.
文摘Lung cancer is one of the malignant tumors with the fastest increase in morbidity and mortality and the greatest threat to people’s health and life.Worldwide,lung cancer is the leading cause of cancer death in men and the second leading cause of cancer deaths in women[1].Lung cancer is divided into two major groups,small cell lung cancer(SCLC)and non-small cell lung cancer(NSCLC)[2].SCLC accounts for approximately 20%of lung cancers.It has a high degree of malignancy and early metastasis,and is sensitive to chemotherapy and radiotherapy.The initial remission rate is high,but it is prone to secondary drug resistance and relapse.Chemotherapy is the mainstay.NSCLC includes three major histological subtypes,lung squamous cell carcinoma(SCC),lung adenocarcinoma(ADC),and large cell lung cancer(LCLC),accounting for approximately 80%of lung cancers.Cell division is slower,and the diffusion shift is relatively late[3].Nevertheless,while current research on the biological characteristics of different histological subtypes of NSCLC is expanding,its basic molecular mechanism is not yet clear.For example,smoking is more risky for SCC than ADC[4].Micro-RNA is an endogenous small RNA with a length of approximately 19–25 nucleotides.As a short non-coding RNA,its main function is to regulate the expression level of mRNA.miRNAs can be used as proto-oncogenes or tumor suppressors,and participate in various processes including proliferation,apoptosis,metabolism,and differentiation of cells through targeted binding to different transcripts[5].miRNAs are expressed in specific tissue and developmental stages under normal physiological conditions,but abnormal expression of miRNAs can lead to a series of pathological states,such as tumorigenesis and metastasis[6–7].miRNA regulates the function of tumor cells by regulating the expression of functional proteins.For example,miR-206 promotes breast cancer proliferation by inhibiting estrogen receptor alpha(ERα)while miR-34a downregulates E2 factor transcription factor 2(E2F2)expression to regulate the cell cycle and apoptosis[8–9].CIP2A,as an oncogenic protein during the malignant transformation and progression of cancer cells,has been shown to have a certain relationship with the efficacy of many drugs in cancer treatment.Oncoprotein CIP2A,also known as KIAA1524 or P90,was named in 2007 and is a cancerous inhibitor of PP2A due to its effect on cancer cells.The stability of PP2A and MYC is controlled to form a"carcinogenic connection"[10].In this study,we found that miR-375 regulated the expression of downstream protein kinase B(AKT),MYC,p-AKT and other related proteins through the CIP2A/PP2A signaling pathway,inhibiting the cancer phenotype of lung cancer,and affecting cell invasion,proliferation,apoptosis,and the cell morphology process.We found that the CIP2A gene is a direct binding target of miR-375.Thus,it has become a topic of great interest to explore whether and how miR-375 regulates ADC cells through the CIP2A signaling pathway.By up-regulating miR-375 in a lentivirus-transfected A549 cell line,we found that a series of phenotypes,including cell invasion,proliferation,and apoptosis were changed,and that CIP2A and its downstream signaling proteins were also changed.
文摘Objective: To investigate the effects of histamine on growth and apoptosis of human melanoma cells A375. Methods: The effect of histamine on growth of A375 cells in vitro was examined by MTT assay and Trypan blue exclusion assay. Cell cycle analysis, early apoptosis analysis by double staining with Annexin V-FITC and PI, and active caspase-3 analysis by staining FITC-conjugated monoclonal rabbit anti-active caspase-3 antibody were made by flow cytometer. StreptAvidin-Biotin Complex (SABC) immunocytochemical assays were adopted to detect Bax/Bcl-2 protein expressions.Results: Histamine inhibited proliferation of A375 cells in a dose- and time-dependent manner, and altered cell cycle distribution of A375 cells revealing an increase in G0/G1-phase population, a decrease in S-phase population and the inhibition of G1/S switching. Histamine induced apoptosis of A375 cells (P<0.05), elevated the cells population with detectable active caspase-3 (P<0.05), increased the number of cells forming Bax and decreased the number of cells forming Bcl-2 significantly (P<0.05). Conclusion: That histamine inhibits cell cycle progress of A375 cells is one of the possible mechanisms of proliferation arrest of A375 cells elicited by histamine. Histamine mediates apoptosis in A375 cells that may be caspase-dependent through mitochondria routine. Histamine with high concentration inhibits growth of A375 cells in vitro by interfering proliferation and inducing apoptosis of cells.
文摘Objective： To study apoptotic effects of synthetic retinoic acid 6-[3-（1-adamantyl）-4-hydroxyphenyl]-2-naphthalene carboxylic acid（AHPN） on human skin malignant melanoma A375 cells in comparison with the natural ligand all-trans-retinoic acid（ATRA） in vitro and the mechanisms related to the actions of AHPN. Methods：MTT assay was used to determine the anti-proliferative effects of AHPN and ATRA on A375 cells. Flow cytometry was performed to investigate the influence of AHPN and ATRA on cell cycle and cell apoptosis. In addition, transfection and luciferase activity assays were employed to explore the mechanisms of how AHPN executes its proapoptotic function. Results：Firstly, AHPN promoted apoptosis and GI arrest in A375 cells compared with ATRA. Secondly, the activity of NF-K B in A375 cells treated with AHPN increased 2-3 times compared with solvent DMSO treatment. Conclusion：AHPN, in comparison with ATRA, is a more effective alternative for therapy of malignant melanoma. The potentially proapoptotic function of AHPN requires activation of NF-K B.
基金supported by the National Natural Science Foundation of China(No.30371295).
文摘Objective： To investigate the effects of synthetic retinoid CD437 and acitretin on cell proliferation, apoptosis, cycle arrest and Bax/ Bcl-2 protein expression of melanoma A375 cell, Methods：MTT assay was used to determine the anti-proliferative effects of CD437 and acitretin on melanoma A375 cell, Flow cytometry was performed to investigate the influence of CD437 and acitretin on cell cycle and cell apoptosis. SABC immunocytochemistry was employed for detection of Bax/bcl-2 protein expressions. Results：10^-5 mol/L CD437 was more effective than acitretin in inhibiting proliferation and inducing apoptosis of A375 cell after 24 h treatment, growth inhibiting ratio and apoptosis ratio（58.6%vs43.25% and 28.03%vs17.13%, P 〈 0.05 respectively）. CD437 promoted G0/G1 arrest in melanoma A375 cell, however acitretin could not. CD437 and acitretin could up-regulate the expression of Bax protein and downregulate the expression of bcl-2 protein（P 〈 0.05）. Conclusion：CD437 is more effective than acitretin in inhibiting proliferation and inducing apoptosis and cycle arrest on A375 cell, CD437 may have more potentialities than acitretin for subsidiary treatment of melanoma. Mitochondrial apoptosis pathway is partially involved in two drugs inducing apoptosis on A375 cell.
