Cytochromes P450(CYPs)play a prominent role in catalyzing phase I xenobiotic biotransformation and account for about 75%of the total metabolism of commercially available drugs,including chemotherapeutics.The gene expr...Cytochromes P450(CYPs)play a prominent role in catalyzing phase I xenobiotic biotransformation and account for about 75%of the total metabolism of commercially available drugs,including chemotherapeutics.The gene expression and enzyme activity of CYPs are variable between individuals,which subsequently leads to different patterns of susceptibility to carcinogenesis by genotoxic xenobiotics,as well as differences in the efficacy and toxicity of clinically used drugs.This research aimed to examine the presence of the CYP2B6*9 polymorphism and its possible association with the incidence of B-CLL in Egyptian patients,as well as the clinical outcome after receiving cyclophosphamide chemotherapy.DNA was isolated from whole blood samples of 100 de novo B-CLL cases and also from 100 sex-and age-matched healthy individuals.The presence of the CYP2B6*9(G516T)polymorphism was examined by PCR-based allele specific amplification(ASA).Patients were further indicated for receiving chemotherapy,and then they were followed up.The CYP2B6*9 variant indicated a statistically significant higher risk of B-CLL under different genetic models,comprising allelic(T-allele vs.G-allele,OR=4.8,p<0.001)and dominant(GT+TT vs.GG,OR=5.4,p<0.001)models.Following cyclophosphamide chemotherapy,we found that the patients with variant genotypes(GT+TT)were less likely to achieve remission compared to those with the wild-type genotype(GG),with a response percentage of(37.5%vs.83%,respectively).In conclusion,our findings showed that the CYP2B6*9(G516T)polymorphism is associated with B-CLL susceptibility among Egyptian patients.This variant greatly affected the clinical outcome and can serve as a good therapeutic marker in predicting response to cyclophosphamide treatment.展开更多
Introduction: B-cell chronic lymphocytic leukaemia (B-CLL) represents a low grade B-cell lymphoproliferative disease that is the most common leukaemia in adults. The neoplastic cell is an autoreactive CD5 CD23 B lymph...Introduction: B-cell chronic lymphocytic leukaemia (B-CLL) represents a low grade B-cell lymphoproliferative disease that is the most common leukaemia in adults. The neoplastic cell is an autoreactive CD5 CD23 B lymphocyte. B-CLL may involve the skin, typically in the context of known disease. We present a case of subclinical B-CLL presenting initially in the skin. Case Report: A 73-year-old male developed a lesion on his right cheek in April 2003 compatible with basal cell carcinoma. The re-excision specimen contained a well-differentiated atypical lymphocytic infiltrate consistent with B-CLL along with residual carcinoma. Subsequent laboratory studies revealed peripheral blood lymphocytosis with smudge cells. A diagnosis was made of Rai stage 0 CLL. Chromosomal studies on peripheral blood showed a deletion at 13q14.3. Excision of a second primary skin carcinoma revealed a squamous cell carcinoma in association with B-CLL that was identical to his previously diagnosed skin involvement. Conclusion: This case identifies a cutaneous presentation of subclinical B-CLL. There are two prior reports describing B-CLL presenting initially in the skin. In one case, the infiltrates were incidental on a reexcision specimen. The second report suggests 16%of B-CLL patients have cutaneous manifestations as the first sign of disease.展开更多
AIM:To investigate the role of the overexpression of B7-H3 in apoptosis in colorectal cancer cell lines and the underlying molecular mechanisms.METHODS:SW620 cells that highly overexpressed B7-H3(SW620-B7-H3-EGFP)and ...AIM:To investigate the role of the overexpression of B7-H3 in apoptosis in colorectal cancer cell lines and the underlying molecular mechanisms.METHODS:SW620 cells that highly overexpressed B7-H3(SW620-B7-H3-EGFP)and HCT8 cells stably transfected with B7-H3 sh RNA(HCT8-sh B7-H3)were previously constructed in our laboratory.Cells transfected with p IRES2-EGFP were used as negative controls(SW620-NC and HCT8-NC).Real-time PCR and western blotting analysis were used to detect the m RNA and protein expressions of the apoptosis regulator proteins Bcl-2,Bcl-xl and Bax.A cell proliferation assay was used to evaluate the survival rate and drug sensitivity of the cells.The effect of drug resistance was detected by a cell cycle assay.Active caspase-3western blotting was used to reflect the anti-apoptotic ability of cells.Western blotting was also performed to determine the expression of proteins associated with the Jak2-STAT3 signaling pathway and the apoptosis regulator proteins after the treatment with AG490,a Jak2 specific inhibitor,in B7-H3 overexpressing cells.The data were analyzed by Graph Pad Prism 6 using a non-paired t-test.RESULTS:Whether by overexpression in SW620cells or downregulation in HCT8,B7-H3 significantly affected the expression of anti-and pro-apoptotic proteins,at both the transcriptional and translational levels,compared with the negative control(P<0.05).A cell proliferation assay revealed that B7-H3overexpression increased the drug resistance of cells and resulted in a higher survival rate(P<0.05).In addition,the results of cell cycle and active caspase-3western blotting proved that B7-H3 overexpression inhibited apoptosis in colorectal cancer cell lines(P<0.05).B7-H3 overexpression improved Jak2 and STAT3phosphorylation and,in turn,increased the expression of the downstream anti-apoptotic proteins B-cell CLL/lymphoma 2(Bcl-2)and Bcl-xl,based on western blotting(P<0.05).After treating B7-H3 overexpressing cells with the Jak2-specific inhibitor AG490,the phosphorylation of Jak2 and STAT3,and the expression of Bcl-2 and Bcl-xl,decreased accordingly(P<0.05).This finding suggested that the Jak2-STAT3 pathway is involved in the mechanism mediating the anti-apoptotic ability of B7-H3.CONCLUSION:The overexpression of B7-H3 induces resistance to apoptosis in colorectal cancer cell lines by upregulating the Jak2-STAT3 signaling pathway,potentially providing new approaches to the treatment of colorectal cancer.展开更多
Objective: Chronic lymphocytic leukemia(CLL) and mantle cell lymphoma(MCL) cells over-express a guanine exchange factor(GEF), Rasgrf-1. This GEF increases active Ras as it catalyzes the removal of GDP from Ras so that...Objective: Chronic lymphocytic leukemia(CLL) and mantle cell lymphoma(MCL) cells over-express a guanine exchange factor(GEF), Rasgrf-1. This GEF increases active Ras as it catalyzes the removal of GDP from Ras so that GTP can bind and activate Ras.This study aims to study the mechanism of action of Rasgrf-1 in B-cell malignancies.Methods: N-terminus truncated Rasgrf-1 variants have a higher GEF activity as compared to the full-length transcript therefore a MCL cell line with stable over-expression of truncated Rasgrf-1 was established. The B-cell receptor(BCR) and chemokine signaling pathways were compared in the Rasgrf-1 over-expressing and a control transfected cell line.Results: Cells over-expressing truncated form of Rasgrf-1 have a higher proliferative rate as compared to control transfected cells.BCR was activated by lower concentrations of anti-Ig M antibody in Rasgrf-1 over-expressing cells as compared to control cells indicating that these cells are more sensitive to BCR signaling. BCR signaling also phosphorylates Rasgrf-1 that further increases its GEF function and amplifies BCR signaling. This activation of Rasgrf-1 in over-expressing cells resulted in a higher expression of phospho-ERK, AKT, BTK and PKC-alpha as compared to control cells. Besides BCR, Rasgrf-1 over-expressing cells were also more sensitive to microenvironment stimuli as determined by resistance to apoptosis, chemotaxis and ERK pathway activation.Conclusions: This GEF protein sensitizes B-cells to BCR and chemokine mediated signaling and also upregulates a number of other signaling pathways which promotes growth and survival of these cells.展开更多
文摘Cytochromes P450(CYPs)play a prominent role in catalyzing phase I xenobiotic biotransformation and account for about 75%of the total metabolism of commercially available drugs,including chemotherapeutics.The gene expression and enzyme activity of CYPs are variable between individuals,which subsequently leads to different patterns of susceptibility to carcinogenesis by genotoxic xenobiotics,as well as differences in the efficacy and toxicity of clinically used drugs.This research aimed to examine the presence of the CYP2B6*9 polymorphism and its possible association with the incidence of B-CLL in Egyptian patients,as well as the clinical outcome after receiving cyclophosphamide chemotherapy.DNA was isolated from whole blood samples of 100 de novo B-CLL cases and also from 100 sex-and age-matched healthy individuals.The presence of the CYP2B6*9(G516T)polymorphism was examined by PCR-based allele specific amplification(ASA).Patients were further indicated for receiving chemotherapy,and then they were followed up.The CYP2B6*9 variant indicated a statistically significant higher risk of B-CLL under different genetic models,comprising allelic(T-allele vs.G-allele,OR=4.8,p<0.001)and dominant(GT+TT vs.GG,OR=5.4,p<0.001)models.Following cyclophosphamide chemotherapy,we found that the patients with variant genotypes(GT+TT)were less likely to achieve remission compared to those with the wild-type genotype(GG),with a response percentage of(37.5%vs.83%,respectively).In conclusion,our findings showed that the CYP2B6*9(G516T)polymorphism is associated with B-CLL susceptibility among Egyptian patients.This variant greatly affected the clinical outcome and can serve as a good therapeutic marker in predicting response to cyclophosphamide treatment.
文摘Introduction: B-cell chronic lymphocytic leukaemia (B-CLL) represents a low grade B-cell lymphoproliferative disease that is the most common leukaemia in adults. The neoplastic cell is an autoreactive CD5 CD23 B lymphocyte. B-CLL may involve the skin, typically in the context of known disease. We present a case of subclinical B-CLL presenting initially in the skin. Case Report: A 73-year-old male developed a lesion on his right cheek in April 2003 compatible with basal cell carcinoma. The re-excision specimen contained a well-differentiated atypical lymphocytic infiltrate consistent with B-CLL along with residual carcinoma. Subsequent laboratory studies revealed peripheral blood lymphocytosis with smudge cells. A diagnosis was made of Rai stage 0 CLL. Chromosomal studies on peripheral blood showed a deletion at 13q14.3. Excision of a second primary skin carcinoma revealed a squamous cell carcinoma in association with B-CLL that was identical to his previously diagnosed skin involvement. Conclusion: This case identifies a cutaneous presentation of subclinical B-CLL. There are two prior reports describing B-CLL presenting initially in the skin. In one case, the infiltrates were incidental on a reexcision specimen. The second report suggests 16%of B-CLL patients have cutaneous manifestations as the first sign of disease.
基金Supported by Project of Natural Science Foundation of Jiangsu Province,No.BK2012542the Project of Hospital Management Center of Wuxi City,No.YGZ1108
文摘AIM:To investigate the role of the overexpression of B7-H3 in apoptosis in colorectal cancer cell lines and the underlying molecular mechanisms.METHODS:SW620 cells that highly overexpressed B7-H3(SW620-B7-H3-EGFP)and HCT8 cells stably transfected with B7-H3 sh RNA(HCT8-sh B7-H3)were previously constructed in our laboratory.Cells transfected with p IRES2-EGFP were used as negative controls(SW620-NC and HCT8-NC).Real-time PCR and western blotting analysis were used to detect the m RNA and protein expressions of the apoptosis regulator proteins Bcl-2,Bcl-xl and Bax.A cell proliferation assay was used to evaluate the survival rate and drug sensitivity of the cells.The effect of drug resistance was detected by a cell cycle assay.Active caspase-3western blotting was used to reflect the anti-apoptotic ability of cells.Western blotting was also performed to determine the expression of proteins associated with the Jak2-STAT3 signaling pathway and the apoptosis regulator proteins after the treatment with AG490,a Jak2 specific inhibitor,in B7-H3 overexpressing cells.The data were analyzed by Graph Pad Prism 6 using a non-paired t-test.RESULTS:Whether by overexpression in SW620cells or downregulation in HCT8,B7-H3 significantly affected the expression of anti-and pro-apoptotic proteins,at both the transcriptional and translational levels,compared with the negative control(P<0.05).A cell proliferation assay revealed that B7-H3overexpression increased the drug resistance of cells and resulted in a higher survival rate(P<0.05).In addition,the results of cell cycle and active caspase-3western blotting proved that B7-H3 overexpression inhibited apoptosis in colorectal cancer cell lines(P<0.05).B7-H3 overexpression improved Jak2 and STAT3phosphorylation and,in turn,increased the expression of the downstream anti-apoptotic proteins B-cell CLL/lymphoma 2(Bcl-2)and Bcl-xl,based on western blotting(P<0.05).After treating B7-H3 overexpressing cells with the Jak2-specific inhibitor AG490,the phosphorylation of Jak2 and STAT3,and the expression of Bcl-2 and Bcl-xl,decreased accordingly(P<0.05).This finding suggested that the Jak2-STAT3 pathway is involved in the mechanism mediating the anti-apoptotic ability of B7-H3.CONCLUSION:The overexpression of B7-H3 induces resistance to apoptosis in colorectal cancer cell lines by upregulating the Jak2-STAT3 signaling pathway,potentially providing new approaches to the treatment of colorectal cancer.
文摘Objective: Chronic lymphocytic leukemia(CLL) and mantle cell lymphoma(MCL) cells over-express a guanine exchange factor(GEF), Rasgrf-1. This GEF increases active Ras as it catalyzes the removal of GDP from Ras so that GTP can bind and activate Ras.This study aims to study the mechanism of action of Rasgrf-1 in B-cell malignancies.Methods: N-terminus truncated Rasgrf-1 variants have a higher GEF activity as compared to the full-length transcript therefore a MCL cell line with stable over-expression of truncated Rasgrf-1 was established. The B-cell receptor(BCR) and chemokine signaling pathways were compared in the Rasgrf-1 over-expressing and a control transfected cell line.Results: Cells over-expressing truncated form of Rasgrf-1 have a higher proliferative rate as compared to control transfected cells.BCR was activated by lower concentrations of anti-Ig M antibody in Rasgrf-1 over-expressing cells as compared to control cells indicating that these cells are more sensitive to BCR signaling. BCR signaling also phosphorylates Rasgrf-1 that further increases its GEF function and amplifies BCR signaling. This activation of Rasgrf-1 in over-expressing cells resulted in a higher expression of phospho-ERK, AKT, BTK and PKC-alpha as compared to control cells. Besides BCR, Rasgrf-1 over-expressing cells were also more sensitive to microenvironment stimuli as determined by resistance to apoptosis, chemotaxis and ERK pathway activation.Conclusions: This GEF protein sensitizes B-cells to BCR and chemokine mediated signaling and also upregulates a number of other signaling pathways which promotes growth and survival of these cells.
