ABSTRACT
AIM: To study the role of c-myc oncogene in L6565 leukemia oncogenesis and the effects of therapy by inhibition of its expression with antisense c-myc. METHODS: A recombinant retroviral vector containing antisense c-myc of the murine (pGNCas)was constructed and then transfected into PA317 cells by the method of calcium phosphate precipitation. L6565 clone cells were infected with retrovirus particles. Stable integretion of antisense c-myc was shown by PCR. The change of the malignance and phenotype of L6565as were detected by the examination of the growth, morphology, cells cycle, agar assay and expression of c-myc. RESULTS: The shape of most L6565as cells became spherical. The growth of L6565as was inhibited compared to control cells. The analysis of cells cycle: L6565as cells were arrest in G 0/G 1 phase, decreased in S phase. The ability of L6565as cells to form colony in soft agarose was significantly suppressed. c-myc in L6565as cells was lowly expressed. CONCLUSION: (1)c-myc plays a critical role in L6565 leukemia oncogenesis; (2)Inhibition of expression of c-myc makes partly reversion of malignant phenotype of L6565 murine leukemia clone cells.
ABSTRACT
A Review] The biological characteristics of viral L6565 leukemia cell clone were as follows: (1) The chromosome counts varied 38～114 , and stem cells were 42; (2) Virus particles type A and type C found in the cytoplasm of clone cells; (3) X-C assays were positive, c- myc and c- fos gene overexpressed in clone cells; (4) Differential markers CD4, CD8, CD45R were negative, CD45RO ? were positive; (5) The supernatant of clone cells could induce T or B lymphocytic leukemia/lymphoma and granulocytic leukemia in SSB strain mice. The leukemogenic effect of concentrate supernatant was stronger than non-concentrate supernatant( P