Expression and methylation of the Blym gene in human tumor cell lines

We have examined Blym expression in 11 human tumor cell lines. Increased Blym expression was observed in one of three osteosarcoma cell lines relative to nontransformed human foreskin fibroblasts. In addition, enhanced Blym expression was observed in a melanoma cell line and in 2 of 6 squamous carcinoma cell lines relative to nontransformed, low passage human epithelial cells. We found no evidence of gene amplification or rearrangements of Blym sequences in any of the cell lines we have examined. We further analyzed the state of methylation of the Blym gene in several of the tumor cell lines by Msp I/Hpa 11 restriction endonuclease digestion. All cell lines examined had similar Msp I digestion patterns. However, the different tumor cell lines had different Hpa 11 digestion patterns. Therefore, our results indicate that the Blym gene is differentially expressed and methylated in human tumor cell lines.