RESUMO
BACKGROUND: Liver transplantation (LT), resection (LR), and ablation (LA) are three curative-intent treatment options for patients with early hepatocellular carcinoma (HCC). We aimed to develop a prognostic calculator to compare the long-term outcomes following each of these therapies. METHODS: A total of 976 patients with HCC within the Milan criteria who underwent LT, LR, and LA between 2009 and 2019 from four institutions were evaluated. Multistate competing risks prediction models for recurrence-free survival (RFS), recurrence within the Milan criteria (RWM), and HCC-specific survival (HSS) were derived to develop a prognostic calculator. RESULTS: During a median follow-up of 51 months, 420 (43%) patients developed recurrence. In the multivariate analysis, larger tumor size, multinodularity, older age, male, higher alpha-fetoprotein (AFP), higher albumin-bilirubin (ALBI) grade, and the presence of portal hypertension were significantly associated with higher recurrence and decreased survival rates. The RFS and HSS were both significantly higher among patients treated by LT than by LR or LA and significantly higher between patients treated by LR than by LA (all p < 0.001). For multinodular HCC ≤3 cm, although LT had better RFS and HSS than LR or LA, LA was noninferior to LR. An online prognostic calculator was then developed based on the preoperative clinical factors that were independently associated with outcomes to evaluate RFS, RWM, and HSS at different time intervals for all three treatment options. CONCLUSIONS: Although LT resulted in the best recurrence and survival outcomes, LR and LA also offered durable long-term alternatives. This prognostic calculator is a useful tool for clinicians to guide an informed and personalized discussion with patients based on their tumor biology and liver function.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Transplante de Fígado , Humanos , Masculino , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Hepatectomia/métodos , Transplante de Fígado/métodos , Prognóstico , Estudos Retrospectivos , Recidiva Local de Neoplasia/patologiaRESUMO
Locoregional spread of abdominopelvic malignant tumors frequently results in peritoneal carcinomatosis (PC). The prognosis of PC patients treated by conventional systemic chemotherapy is poor, with a median survival of < 6 mo. However, over the past three decades, an integrated treatment strategy of cytoreductive surgery (CRS) + hyperthermic intraperitoneal chemotherapy (HIPEC) has been developed by the pioneering oncologists, with proved efficacy and safety in selected patients. Supported by several lines of clinical evidence from phasesâ I, II and III clinical trials, CRS + HIPEC has been regarded as the standard treatment for selected patients with PC in many established cancer centers worldwide. In China, an expert consensus on CRS + HIPEC has been reached by the leading surgical and medical oncologists, under the framework of the China Anti-Cancer Association. This expert consensus has summarized the progress in PC clinical studies and systematically evaluated the CRS + HIPEC procedures in China as well as across the world, so as to lay the foundation for formulating PC treatment guidelines specific to the national conditions of China.
Assuntos
Antineoplásicos/administração & dosagem , Procedimentos Cirúrgicos de Citorredução/métodos , Hipertermia Induzida , Neoplasias Peritoneais/terapia , Terapia Combinada , Procedimentos Cirúrgicos de Citorredução/efeitos adversos , Humanos , Hipertermia Induzida/efeitos adversos , Neoplasias Peritoneais/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
OBJECTIVES: Activation of coagulation and fibrinolysis is frequently observed in patients with cancer, even with absence of thrombosis. Furthermore, plasma coagulation parameters were associated with tumor progression, metastasis, and prognosis. Few studies have investigated these associations in pancreatic cancer (PA). This study aimed to investigate the clinical and prognostic significance of various plasma coagulation tests in PA patients with absence of venous thromboembolism (VTE). MATERIALS AND METHODS: A total of 139 PA patients with the absence of VTE were included in the analysis. Patients were followed up for at least 12 months until death. Pretreatment coagulation parameters including prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (APTT), fibrinogen (F), antithrombin-III (AT-III), protein C (PC), factor-VIII (F-VIII), and D-dimer (DD) were evaluated. A total of 40 age-matched and sex-matched healthy individuals without coagulation disorder were enrolled as the control group. RESULTS: Patients were inclined to have higher levels of PT, INR, APTT, F, F-VIII, and DD and lower levels of AT-III and PC than the control group (P<0.01 for all, except P=0.022 for INR and P=0.015 for AT-III). Patients with advanced tumor stages were likely to have higher median DD levels and lower AT-III levels than the control group (P=0.005 and P<0.001, respectively). DD levels were higher in patients with advanced pathology grade (P<0.001). Plasma DD levels (hazards ratio=1.71; 95% confidence interval, 1.07-2.73; P=0.025) were identified as the significantly independent prognostic predictors. CONCLUSIONS: PA patients are susceptible to activation of hemostasis system. Pretreatment plasma DD level was a potential predictor of prognosis in PA patients without VTE.
Assuntos
Carcinoma Ductal Pancreático/sangue , Neoplasias Pancreáticas/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Antitrombina III/metabolismo , Testes de Coagulação Sanguínea , Carcinoma Ductal Pancreático/mortalidade , Carcinoma Ductal Pancreático/patologia , Estudos de Casos e Controles , Estudos de Coortes , Progressão da Doença , Fator VIII/metabolismo , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Fibrinogênio/metabolismo , Seguimentos , Humanos , Coeficiente Internacional Normatizado , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/patologia , Tempo de Tromboplastina Parcial , Prognóstico , Modelos de Riscos Proporcionais , Proteína C/metabolismo , Tempo de Protrombina , Estudos Retrospectivos , Tromboembolia Venosa/sangueRESUMO
BACKGROUND: There is an increasing frequency of pancreaticoduodenectomy (PD) and PD with superior mesenteric-portal vein (SMPV) resection in elderly cancer patients. The study aimed to investigate the safety and the survival benefits of PD and PD with SMPV resection in patients under or over 70 years of age. METHODS: We divided 296 patients who had undergone PD and PD with SMPV resection into two groups according to their ages: under or over 70 years old. The clinical data were compared between the two groups. RESULTS: Preoperative comorbidity rate was higher in elder patients than in younger patients (P=0.001). The elder patients were more likely to have postoperative complications (P=0.003). Specifically, complications above grade III were more likely to occur in the elderly patients (P=0.030). Multivariable analysis showed that age (adjusted OR=2.557, P=0.015) and hypertension (adjusted OR=2.443, P=0.019) were independent predictors of postoperative complications. There was no significant difference in the mortality rates between the two groups (P=0.885). In the PD with SMPV resection series, elderly patients were more likely to have postoperative complications (P=0.063), but this difference was not statistically significant. There was no difference in the survival rate of patients with pancreatic ductal adenocarcinoma between the two groups. Operation type (PD vs PD with SMPV resection) did not affect the survival of patients. CONCLUSIONS: Age affects postoperative complication in patients undergoing either PD or PD with SMPV resection. However, extensive experience and advanced perioperative management lower the complication rate to an acceptable limit. Hence it is safe and worthwhile to perform PD for elderly patients. Because of low numbers in the SMPV subset, we could not conclude whether PD with SMPV resection is feasible in elderly patients.
Assuntos
Neoplasias do Sistema Digestório/cirurgia , Veias Mesentéricas/cirurgia , Pancreaticoduodenectomia , Veia Porta/cirurgia , Procedimentos Cirúrgicos Vasculares , Fatores Etários , Idoso , Comorbidade , Neoplasias do Sistema Digestório/mortalidade , Neoplasias do Sistema Digestório/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pancreaticoduodenectomia/efeitos adversos , Seleção de Pacientes , Complicações Pós-Operatórias/mortalidade , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Resultado do Tratamento , Procedimentos Cirúrgicos Vasculares/efeitos adversosRESUMO
OBJECTIVE: This study aimed to investigate the efficacy and safety of palliative bypass surgery combined with cryoablation in treating patients with advanced pancreatic cancer and compare this combination therapy with palliative bypass surgery alone. METHODS: Medical records of 118 patients with advanced pancreatic cancer who received palliative bypass surgery combined with cryoablation (the combination treatment group) or bypass surgery alone (the bypass surgery alone group) at the Department of Pancreatic Cancer, Tianjin Medical University Cancer Institute and Hospital (Tianjin, China) were retrospectively reviewed. Their baseline and peri-operative parameters were collected and compared. RESULTS: In both groups abdominal distension and pain was significantly ameliorated after treatment. Preoperative jaundice was more common in the bypass surgery group while backache was more frequent in the combination treatment group, which were both relieved by treatment. The pre-operative serum bilirubin level was higher in the bypass surgery group and was decreased significantly after treatment. However, a significant reduction in tumor size and serum carbohydrate antigen 19-9 level was found only in the combination treatment group. There was no significant difference in the incidence of postoperative complications and prognosis between the two groups. CONCLUSIONS: Cryoablation can reduce tumor size and relieve the patients' symptoms and signs such as abdominal discomfort and backache, although it could not improve the patients' prognosis significantly. It is a safe and efficient modality when combined with bypass surgery for patients with advanced pancreatic cancer.
Assuntos
Criocirurgia/métodos , Cuidados Paliativos/métodos , Neoplasias Pancreáticas/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada , Criocirurgia/efeitos adversos , Feminino , Gastroenterostomia/efeitos adversos , Gastroenterostomia/métodos , Humanos , Jejunostomia/métodos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/patologia , Prognóstico , Estudos Retrospectivos , Análise de Sobrevida , Resultado do TratamentoRESUMO
HPP1 (hyperplastic polyposis protein 1), a tumor suppressor gene, is downregulated by promoter hypermethylation in a number of tumor types including colon cancer. c-Myc is also known to play a role in the suppression of HPP1 expression via binding to a promoter region cognate E-box site. The contribution of histone deacetylation as an additional epigenetic mechanism and its potential interplay with c-Myc in the transcriptional regulation of HPP1 are unknown. We have shown that the treatment of the HPP1-non-expressing colon cancer cell lines, HCT116 and DLD-1 with HDAC inhibitors results in re-expression of HPP1. RNAi-mediated knockdown of c-Myc as well as of HDAC2 and HDAC3 in HCT116 and of HDAC1 and HDAC3 in DLD-1 also resulted in significant re-expression of HPP1. Co-immunoprecipitation (IP), chromatin IP (ChIP), and sequential ChIP experiments demonstrated binding of c-Myc to the HPP1 promoter with recruitment of and direct interaction with HDAC3. In summary, we have demonstrated that c-Myc contributes to the epigenetic regulation of HPP1 via the dominant recruitment of HDAC3. Our findings may lead to a greater biologic understanding for the application of targeted use of HDAC inhibitors for anti-cancer therapy.
Assuntos
Neoplasias do Colo/metabolismo , Histona Desacetilases/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Acetilação , Linhagem Celular Tumoral , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Regulação para Baixo , Epigênese Genética , Técnicas de Silenciamento de Genes , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/genética , Histonas/metabolismo , Humanos , Proteínas de Membrana/genética , Proteínas de Neoplasias/genética , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-myc/genética , RNA Interferente Pequeno/genética , Transcrição GênicaRESUMO
OBJECTIVE: To discussion the in vitro molecular mechanism of leptin promoting the expression of hTERT in breast cancer cells. METHODS: The hTERT mRNA expression of STAT3 knockdown on leptin-induced hTERT was measured by reverse transcription-polymerase chain reaction (RT-PCR). Determine the expression of hTERT protein after different treatments in MCF7 by Western blot. Chromatin immunoprecipitation assay (ChIP) was performed to detect the binding of STAT3 to hTERT promoter in MCF7. Luciferase assay was used to confirm the effects of leptin and STAT3 phosphorylation inhibitor on the transcriptional activity of hTERT promoter. RESULTS: The RT-PCR analysis showed that knockdown of STAT3 significantly reduced the leptin-induced transcription of hTERT. Western blot showed that the expression of hTERT were 3.109 ± 0.051 and 1.025 ± 0.031 after leptin or both of leptin and AG490 treatments. The results of CHIP showed that the mRNA of control and leptin (160 ng/ml) treatment were 1 and 3.311 ± 0.017. Leptin increased the combination of STAT3 and hTERT promoter. Luciferase assay showed that when the concentration of leptin was 160 ng/ml, the hTERT promoter activity was 80.98 ± 0.18 while the control was 20.76 ± 0.31. After AG490 treatment, the hTERT promoter activity was 18.65 ± 0.32,significantly reduced the leptin-induced activity of hTERT promoter. CONCLUSION: Leptin/STAT3 signaling is a novel pathway for the up-regulation of hTERT expression in breast cancer cells.
Assuntos
Neoplasias da Mama/metabolismo , Leptina/farmacologia , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Telomerase/metabolismo , Neoplasias da Mama/genética , Técnicas de Silenciamento de Genes , Humanos , Células MCF-7 , Telomerase/genéticaRESUMO
OBJECTIVE: To explore the apoptosis resistance induced by Leptin and its mechanism in breast cancer cells in vitro. METHODS: The leptin-mediated reduction of docetaxel-induced apoptosis in human breast cancer T47D cells was evaluated by TransAM ELISA, MTT and caspase-9 assay. The leptin-promoted survivin expression was analyzed by Western-blot and RT-PCR. The reversing effect of STAT3 knockdown on leptin-induced survivin upregulation was measured by Western-blot and RT-PCR. RESULTS: Leptin promoted T47D cells proliferation and the inhibitory rate was -63.6%. It reduced docetaxel-induced apoptosis in T47D cells by 31.9%. Leptin at different concentrations promoted survivin protein and mRNA expression in T47D cells. The expression of survivin mRNA was 4.6 fold compared with the T47D cells not treated with leptin(10 nmol/L). The expression of survivin mRNA in T47D cells was 0.55 +/- 0.15 fold after transfected with small interfering RNA (siRNA) of STAT3. The expression of survivin mRNA in STAT3 siRNA group and mock transfected group were 0.56 +/- 0.18 fold and 1.61 +/- 0.22 fold after treated by leptin, respectively. The survivin protein level of T47D mock transfected cells was increased after treated by leptin, but the protein level of T47D transfected with STAT3 siRNA cells were not changed significantly. CONCLUSION: Leptin/STAT3 signaling is a novel pathway for up-regulation of survivin expression in breast cancer cells.
Assuntos
Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Leptina/farmacologia , Proteínas Associadas aos Microtúbulos/metabolismo , Fator de Transcrição STAT3/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Proteínas Inibidoras de Apoptose , Proteínas Associadas aos Microtúbulos/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Survivina , Transfecção , Regulação para CimaRESUMO
OBJECTIVE: To elucidate the modulating effect of proapoptotic protein Bax on the resistance of malignant lymphoma cells to tumor necrotic factor-related apoptosis inducing ligand (TRAIL)-induced apoptosis and offer evidence for clinic work. METHODS: Human malignant lymphoma cells of the line CRL and normal HRC cells were cultured and treated by 500 g/L TRAIL (Group T), treated by 10 nmol/L PS-341 (Group P), or pre-treated by 10 nmol/L proteasome inhibitor PS-341 for 1 hour and then treated by 500 microg/L TRAIL (Group P + T). Flow cytometry was used to detect the cell apoptosis. Western blotting was used to detect the expression of Bax protein. Caspase-8 activity was tested by fluorophotometer. Immunoprecipitation method was used to examine the conformation change of Bax protein. RESULTS: The apoptosis index 24 hours after treatment of the CRL cells of Group T was 21%, significantly lower than that of the HRC cells of Group T (32%, P < 0.01). The Bax protein expression amount 24 hours after treatment of the HRC cells of Group T was 1.8 times that of the normal cells, and the Bax protein expression amount 24 hours after treatment of the CRL cells of Group T was only 5/17 that of the normal amount. The apoptotic index 6 hours after treatment of the CRL cells of Group P + T was 54%, significantly higher than those of Groups T and P (both P < 0.01). The caspase-8 activity 6 hours after treatment of the CRL cells of Group P + T was 26.5 micromol.L(-1).h(-1).mg(-1) protein, similar to that of the HRC cells of Group P + T (27.2 micromol.L(-1).h(-1).mg(-1) protein), and significantly higher than those of the other cells (all P < 0.01). The Bax protein expression 6 hours after treatment of the Group P HRC and CRL cells were 2.5 times and 1.2 times that of the control cells. The Bax protein expression of the HRC cells of Group P + T was 3.3 times that of the normal controls, and the Bax degradation of the CRL cells of Group P + T was significantly reduced. The combination treatment of P + T significantly increased the expression of activated Bax. CONCLUSION: Bax degradation plays an important role in the resistance of malignant lymphoma to TRAIL-induced apoptosis. Using proteasome inhibitor can inhibit the protein degradation and overcome the drug resistance.
Assuntos
Apoptose/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Proteína X Associada a bcl-2/biossíntese , Western Blotting , Caspase 3/metabolismo , Linhagem Celular Tumoral , Citometria de Fluxo , Humanos , Linfoma/metabolismo , Linfoma/patologiaRESUMO
OBJECTIVE: To explore the effects of mitochondrial pathways on apoptosis in colon carcinoma cells induced by Tumor necrosis factor related apoptosis inducing ligand and offer evidences for TRAIL application in clinic. METHODS: Apoptosis, integration of mitochondria (including DeltaPsim, cardiolipin), activity of Caspase-9 and release of cytochrome c in colon carcinoma cells SW1116 treated with TRAIL, were detected by means of flowcytometry, fluorometer method and western-blot at the different time point. RESULTS: After treated with TRAIL for 4 hours, the apoptosis index was 32.98%, and the damage of mitochondria occurred with DeltaPsim, cardiolipin decreased, and the activity of Caspase-9 and cytochrome c increased. The Caspase-9 activity at 24 hour was (48.12+/-2.21)micromol.L(-1).h(-1).mg(-1) protein. Mitochondrial damage induced by TRAIL could be inhibited by Caspase inhibitor Z-VAD. fmk. CONCLUSION: Mitochondrial pathways involved in the apoptosis of colon carcinoma cell induced by TRAIL. Cytochrome c was released and Caspase-9 was activated in the Caspase-dependent manner after the damage of mitochondrial.
Assuntos
Apoptose , Caspase 9/metabolismo , Mitocôndrias/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Cardiolipinas/metabolismo , Linhagem Celular Tumoral , Citocromos c/metabolismo , Humanos , Membranas Mitocondriais/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismoRESUMO
OBJECTIVE: To explore the potential mechanisms of leukemia cell resistance to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) -induced apoptosis. METHODS: Cells apoptosis, changes of mitochondrial membrane potential, activity of NF-kappaB, activity of caspase-8 and expressions of apoptosis-related proteins in TRAIL treated K562 and CEM cells, were detected by flowcytometry, ELISA and Western blotting methods, respectively. RESULTS: After treated with TRAIL, the apoptosis indexes were 29.98% and 14.1%, and mitochondrial membrane potential were decreased to 73.25% and 25.4% in K562 and CEM cells respectively. Constitutive level of caspase-8 expression in CEM was lower than that in K562 cells. Both cells became over-expressed Bcl-xL and down-regulated Bax. The ratio of Bcl-xL/Bax in CEM cells was higher than that in K562 cells. Compared with that in K562, the NF-kappaB activity increased significantly in CEM after treatment with TRAIL in early stage. CONCLUSION: CEM cells were more resistant to TRAIL-induced apoptosis than K562 cells did. The potential mechanisms associated with CEM drug resistance might be the lower expression of the constitutive level of caspase-8, lower sensitivity of mitochondrial inner membrane, early increase in NF-KB activity and altered expression of Bcl-2 proteins family.
Assuntos
Apoptose/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Proteínas Reguladoras de Apoptose/metabolismo , Caspase 8/metabolismo , Humanos , Células K562 , Ligantes , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Células Tumorais CultivadasRESUMO
AIM: To evaluate the effect of antisense vascular endothelial growth factor (VEGF) RNA (PCMV-FGEV) transfection on the profile of hepatocellular carcinoma (HCC) SMMC-7721 cells in vitro and in vivo. METHODS: SMMC-7721 cells were transfected with PCMV-FGEV antisense, PCMV-VEGF sense and empty vector plasmid encapsulated by lipofectamine as antisense group, sense group and control group respectively. The positive cell clones were selected with G418. The stable transfection and expression of VEGF in the cells were determined by RT-PCR and immunohistochemistry. Cell proliferation was observed by MTT assay. FACS analysis was used to determine the effect of PCMV-FGEV transfection on cell apoptosis. The growth of transfected cells in vivo was also observed in nude mice. RESULTS: VEGF expression was reduced in SMMC-7721 transfected with PCMV-FGEV, which was confirmed by RT-PCR and immunohistochemistry. No effect of PCMV-FGEV transfection was found on cell proliferation and cell apoptosis of SMMC-7721 in vitro. The growth of cells transfected with PCMV-FGEV was slow in nude mice and accompanied with obvious apoptosis. The latent time of tumors in the antisense group was 25.0 +/- 1.8 d, which was longer than that in sense and control groups (F = 19.455, P < 0.01). The average tumor weight in antisense group (0.96 g +/- 0.28 g) was the smallest among the three groups (F = 21.501, P < 0.01). CONCLUSION: The expression of VEGF can be inhibited by antisense PCMV-FGEV. Antisense PCMV-FGEV has no effect on cell proliferation and apoptosis of SMMC-7721 in vitro but can inhibit tumor growth and induce cell apoptosis in vivo.
Assuntos
Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Fígado/efeitos dos fármacos , RNA Antissenso/farmacologia , Fator A de Crescimento do Endotélio Vascular/genética , Animais , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/química , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/ultraestrutura , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Fator VIII/análise , Fator VIII/genética , Feminino , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Fígado/patologia , Neoplasias Hepáticas/química , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/ultraestrutura , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , RNA Antissenso/uso terapêutico , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção , Fator A de Crescimento do Endotélio Vascular/análiseRESUMO
Previous studies have shown that the lymphoblastic leukemia CEM cell line is resistant to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis because of a low expression of caspase-8. Bcl-2 inhibitors, BH3I-2' and HA14-1, are small cell-permeable nonpeptide compounds, are able to induce apoptosis by mediating cytochrome c release, and also lead to dissipation of the mitochondrial membrane potential (DeltaPsim). This study aimed to use the Bcl-2 inhibitors to sensitize CEM cells to TRAIL-induced apoptosis by switching on the mitochondrial apoptotic pathway. We found that a low dose of BH3I-2' or HA14-1, which did not induce cytochrome c release, greatly sensitized CEM cells to TRAIL-induced apoptosis. In a similar manner to the classical uncoupler carbonyl cyanide m-chlorophenylhydrazone (CCCP), both BH3I-2' and HA14-1 induced a reduction in DeltaPsim, a generation of reactive oxygen species (ROS), an increased mitochondrial respiration, and a decreased ATP synthesis. This uncoupling function of the Bcl-2 inhibitors was responsible for the synergy with TRAIL-induced apoptosis. CCCP per se did not induce apoptosis but again sensitized CEM cells to TRAIL-induced apoptosis by uncoupling mitochondrial respiration. The uncoupling effect facilitated TRAIL-induced Bax conformational change and cytochrome c release from mitochondria. Inhibition of caspases failed to block TRAIL-mediated cell death when mitochondrial respiration was uncoupled. We observed that BH3I-2', HA14-1, or CCCP can overcome resistance to TRAIL-induced apoptosis in TRAIL-resistant cell lines, such as CEM, HL-60, and U937. Our results suggest that the uncoupling of mitochondrial respiration can sensitize leukemic cells to TRAIL-induced apoptosis. However, caspase activation per se does not represent an irreversible point of commitment to TRAIL-induced cell death when mitochondrial respiration is uncoupled.
Assuntos
Apoptose/efeitos dos fármacos , Benzamidas/farmacologia , Benzopiranos/farmacologia , Leucemia de Células T/tratamento farmacológico , Glicoproteínas de Membrana/farmacologia , Mitocôndrias/efeitos dos fármacos , Nitrilas/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Fator de Necrose Tumoral alfa/farmacologia , Desacopladores/farmacologia , Proteínas Reguladoras de Apoptose , Carbonil Cianeto m-Clorofenil Hidrazona/farmacologia , Citocromos c/metabolismo , Sinergismo Farmacológico , Células HL-60 , Humanos , Células K562 , Leucemia de Células T/metabolismo , Leucemia de Células T/patologia , Mitocôndrias/metabolismo , Fosforilação Oxidativa/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Proteínas Proto-Oncogênicas/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF , Proteína X Associada a bcl-2RESUMO
OBJECTIVE: To determine the effects of PCMV-FGEV transfection on the profile of SMMC-7721 hepatocellular in vitro in vivo. METHODS: SMMC-7721 hepatocellular was transfected with PCMV-FGEV antisense, PCMV-VEGF sense and empty vector plasmid encapsulated by lipofectamine. The positive cell clones were selected with G418. The stable transfection and expression of VEGF in the SMMC-7721 hepatocellular were determined by in situ hybridization and immunochemical analysis. The effect of PCMV-FGEV transfection on SMMC-7721 hepatocellular proliferation was observed by MTT colorimetric assay. Flow cytometry was used to determine the effects of PCMV-FGEV transfection on cell apoptosis of SMMC-7721. The growth of transfected cells was also observed in nude mice. RESULTS: There was reduced VEGF expression in SMMC-7721 transfected with PCMV-FGEV confirmed by in situ hybridization and immunohistochemical analysis. There was no effect of PCMV-FGEV transfection on cell proliferation and cell apoptosis of SMMC-7721 in vitro. The growth of cell with PCMV-FGEV transfected was slow in nude mice (vivo) and accompanied with obvious apoptosis. The latent time of tumor in the antisense mice group was 25.0+/-1.8 days, which was longer than that in sense and control group significantly (F=19.455, P<0.01). On the other hand, the average tumor weight in antisense group (0.96 g+/-0.28 g) was the smallest among the three groups (F=21.501, P<0.01). CONCLUSIONS: The expression of VEGF was inhibited by PCMV-FGEV. There was no effect on cell proliferation and cell apoptosis of SMMC-7721 by transferring PCMV-FGEV gene into SMMC-7721 cells in vitro. But in vivo it can inhibit tumor growth and induce cell apoptosis.