OBJECTIVE: To study the molecular mechanism of tumorigenicity in nude mice of human leukemia cell lines. METHODS: K562-n, is a human leukemic cell line with much higher tumorigenecity in nude mice compared with the parental K562 cell line by repeated in vitro and in vivo passages. Genes differentially expressed between K562 and K562-n cells were analyzed by using DNA microarray technique. RESULTS: Of 12 000 genes screened were differentially expressed significantly, among which 42 genes were up-regulated and 97 genes were down-regulated in K562-n cells. Eighty-five of the 139 genes have been registered in the GeneBank and 54 are unknown genes. The genes accessible from the GenBank include: 1. oncogenes and tumor-supressor genes, 2. genes related to transcription regulation, cell cycle and apoptosis, 3. genes related to cytoskeleton and cytokinetics, 4. genes related to metabolism and transport, 5. genes related to immune function. There were also some differentially expressed genes with mixed functions and some with unknown function differentially expressed. CONCLUSION: There are many genes differentially expressed between K562-n and K562 cells. The high tumorigenicity in nude mice of human leukemia cell line K562-n might be related to its specific gene expression profile.
OBJECTIVE: To study the molecular mechanism of tumorigenicity in nude mice of humanleukemia cell lines. METHODS: K562-n, is a humanleukemic cell line with much higher tumorigenecity in nude mice compared with the parental K562 cell line by repeated in vitro and in vivo passages. Genes differentially expressed between K562 and K562-n cells were analyzed by using DNA microarray technique. RESULTS: Of 12 000 genes screened were differentially expressed significantly, among which 42 genes were up-regulated and 97 genes were down-regulated in K562-n cells. Eighty-five of the 139 genes have been registered in the GeneBank and 54 are unknown genes. The genes accessible from the GenBank include: 1. oncogenes and tumor-supressor genes, 2. genes related to transcription regulation, cell cycle and apoptosis, 3. genes related to cytoskeleton and cytokinetics, 4. genes related to metabolism and transport, 5. genes related to immune function. There were also some differentially expressed genes with mixed functions and some with unknown function differentially expressed. CONCLUSION: There are many genes differentially expressed between K562-n and K562 cells. The high tumorigenicity in nude mice of humanleukemia cell line K562-n might be related to its specific gene expression profile.