In order to assess the significance of BCR/ABC fusion gene in adult acute lymphoblastic Leukemia (ALL), 28 patients who were diagnosed as ALL were enrolled to detect BCR/ABC gene using nested-RT-PCR. The results showe...In order to assess the significance of BCR/ABC fusion gene in adult acute lymphoblastic Leukemia (ALL), 28 patients who were diagnosed as ALL were enrolled to detect BCR/ABC gene using nested-RT-PCR. The results showed that 9 cases (31.25%) were BCR/ABL positive, and expressed P210 subtype. Among them 7 cases were B-ALL, and one was T-ALL. The diagnosis was proved by monoclonal antibodies recognition by indirect immunofluorescence. Adult patients with BCR/ABL positive ALL were significantly older (p<0.01) and had higher WBC count (p<0.01) as compared with BCR/ABL-negative patients. There was no significant difference in sex, hemoglobin and splenomegaly between two group (p>0.05). The induction failure rate was high in BCR/ABL positive patients and those who achieved complete remission usually relapsed earlier. In conclusion, adult ALL patients with BCR/ABL-positive have poorer prognosis.展开更多
BCR-ABL fusion oncogene originates from the reciprocal translocation of chromosome 9 and 22 t(9;22) (q34;q11). It translates a chimeric protein, p210, characterized by constitutive activation of its tyrosine kinase, w...BCR-ABL fusion oncogene originates from the reciprocal translocation of chromosome 9 and 22 t(9;22) (q34;q11). It translates a chimeric protein, p210, characterized by constitutive activation of its tyrosine kinase, which triggers leukemogenic pathways resulting in onset of chronic myeloid leukemia (CML). In CML, the classic fusion is b2a2 or b3a2 fusing exon 13 (b2) or exon 14 (b3) of BCR to exon 2 (a2) of ABL. The type of bcr/abl transcripts may be associated with different prognosis and hence useful in therapeutic plan. This study was conducted to calculate the frequency of these splice variants as the frequencies of different fusion oncogenes associated with leukaemia can vary in different geographical regions due to interplay of genetic variation in different ethnic populations, diverse environmental factors and living style. A very sensitive nested RT-PCR was established to detect BCR-ABL splice variants in CML. Sensitivity of RT-PCR assay was of the order of 10–6. Thirty CML patients were subjected to BCR-ABL analysis. Out of 30 Pakistani patients, 19 (64%) expressed b3a2 while 11 (36%) expressed b2a2 transcript. This shows that BCR-ABL splice variants differ in their frequencies which may have an effect on biology and implications for prognosis and management of BCR-ABL positive Leukemias.展开更多
Objective: To investigate the in vitro cleavage ability and effects on apoptosis and cell growth of the bcr-abl fusion gene specific multi-unit ribozymes. Methods: Three fusion point specific ribozymes were designed ...Objective: To investigate the in vitro cleavage ability and effects on apoptosis and cell growth of the bcr-abl fusion gene specific multi-unit ribozymes. Methods: Three fusion point specific ribozymes were designed and the multi-unit ribozymes?in vitro transcription vector and retroviral vector were constructed. The in vitro cleavage ability was tested. The retroviral vector was transfected into K562 cell and the effects on proliferation, apoptosis, cell cycle and cell structure were observed. Results: Multi-unit ribozymes had in vitro cleavage efficiency of 70.8%, which was more efficient than single-unit and double-unit ribozymes. Transfection of the retroviral vector of the ribozyme into K562 cells, induced inhibition of cell growth and apoptosis. The incorporation rate of DNA in ribozymes transfected K562 cells was greatly decreased along with time passed, with an inhibition rate of more than 50% after 96 h of transfection. Under FCM, 18.4% of the cells underwent apoptosis 72 h after transfection and more cells were blocked in G phase, with the ratio in S phase greatly decreased (41.9%). Under electron microscope, compaction of nuclear chromatin and apoptosis bodies were observed. Conclusion: Multi-unit ribozymes specific to bcr-abl fusion gene can be used to treat CML and to purge bone marrow for self-grafting.展开更多
Objective: To investigate the effect of bcr-abl fusion gene on CML cell apoptosis. Methods: Apoptosis of ex-vivo cultured K562 cells were observed after exposure to synthetic 18 mer antisense oligodeoxynucleotide comp...Objective: To investigate the effect of bcr-abl fusion gene on CML cell apoptosis. Methods: Apoptosis of ex-vivo cultured K562 cells were observed after exposure to synthetic 18 mer antisense oligodeoxynucleotide complementary to the bcr-abl junction (b3a2). Results: Apoptosis of K562 cells was significantly increased associated with inhibition of bcr-abl expression. Conclusion: bcr-abl fusion gene formation due to chromosome translocation may be the major mechanism of CML via inhibition of apoptosis.展开更多
文摘In order to assess the significance of BCR/ABC fusion gene in adult acute lymphoblastic Leukemia (ALL), 28 patients who were diagnosed as ALL were enrolled to detect BCR/ABC gene using nested-RT-PCR. The results showed that 9 cases (31.25%) were BCR/ABL positive, and expressed P210 subtype. Among them 7 cases were B-ALL, and one was T-ALL. The diagnosis was proved by monoclonal antibodies recognition by indirect immunofluorescence. Adult patients with BCR/ABL positive ALL were significantly older (p<0.01) and had higher WBC count (p<0.01) as compared with BCR/ABL-negative patients. There was no significant difference in sex, hemoglobin and splenomegaly between two group (p>0.05). The induction failure rate was high in BCR/ABL positive patients and those who achieved complete remission usually relapsed earlier. In conclusion, adult ALL patients with BCR/ABL-positive have poorer prognosis.
文摘BCR-ABL fusion oncogene originates from the reciprocal translocation of chromosome 9 and 22 t(9;22) (q34;q11). It translates a chimeric protein, p210, characterized by constitutive activation of its tyrosine kinase, which triggers leukemogenic pathways resulting in onset of chronic myeloid leukemia (CML). In CML, the classic fusion is b2a2 or b3a2 fusing exon 13 (b2) or exon 14 (b3) of BCR to exon 2 (a2) of ABL. The type of bcr/abl transcripts may be associated with different prognosis and hence useful in therapeutic plan. This study was conducted to calculate the frequency of these splice variants as the frequencies of different fusion oncogenes associated with leukaemia can vary in different geographical regions due to interplay of genetic variation in different ethnic populations, diverse environmental factors and living style. A very sensitive nested RT-PCR was established to detect BCR-ABL splice variants in CML. Sensitivity of RT-PCR assay was of the order of 10–6. Thirty CML patients were subjected to BCR-ABL analysis. Out of 30 Pakistani patients, 19 (64%) expressed b3a2 while 11 (36%) expressed b2a2 transcript. This shows that BCR-ABL splice variants differ in their frequencies which may have an effect on biology and implications for prognosis and management of BCR-ABL positive Leukemias.
基金National Natural Science Foundation of China (No. 39670330).
文摘Objective: To investigate the in vitro cleavage ability and effects on apoptosis and cell growth of the bcr-abl fusion gene specific multi-unit ribozymes. Methods: Three fusion point specific ribozymes were designed and the multi-unit ribozymes?in vitro transcription vector and retroviral vector were constructed. The in vitro cleavage ability was tested. The retroviral vector was transfected into K562 cell and the effects on proliferation, apoptosis, cell cycle and cell structure were observed. Results: Multi-unit ribozymes had in vitro cleavage efficiency of 70.8%, which was more efficient than single-unit and double-unit ribozymes. Transfection of the retroviral vector of the ribozyme into K562 cells, induced inhibition of cell growth and apoptosis. The incorporation rate of DNA in ribozymes transfected K562 cells was greatly decreased along with time passed, with an inhibition rate of more than 50% after 96 h of transfection. Under FCM, 18.4% of the cells underwent apoptosis 72 h after transfection and more cells were blocked in G phase, with the ratio in S phase greatly decreased (41.9%). Under electron microscope, compaction of nuclear chromatin and apoptosis bodies were observed. Conclusion: Multi-unit ribozymes specific to bcr-abl fusion gene can be used to treat CML and to purge bone marrow for self-grafting.
文摘Objective: To investigate the effect of bcr-abl fusion gene on CML cell apoptosis. Methods: Apoptosis of ex-vivo cultured K562 cells were observed after exposure to synthetic 18 mer antisense oligodeoxynucleotide complementary to the bcr-abl junction (b3a2). Results: Apoptosis of K562 cells was significantly increased associated with inhibition of bcr-abl expression. Conclusion: bcr-abl fusion gene formation due to chromosome translocation may be the major mechanism of CML via inhibition of apoptosis.
