Romero P, Beran M, Shtalrid M, Andersson B, Talpaz M, Blick M
Department of Clinical Immunology, University of Texas M.D. Anderson Cancer Center, Houston 77030.
Oncogene. 1989 Jan;4(1):93-8.
Philadelphia chromosome positive acute lymphocytic leukemia and chronic myelogenous leukemia are strongly associated with two distinct forms of bcr-abl chimeric protein, known as P190 and P210, respectively. By studying cDNA clones obtained from the cell line KBM-5, we identified two new bcr-abl transcripts. These are formed by alternative splicing of at least two exons to the known bcr exon 2. One novel transcript can encode a protein kinase of approximately 190 kd, while the other can direct the synthesis of a larger protein whose amino terminus remains to be defined. The alternative exons can be spliced also to the two normal bcr transcripts, reflecting the activation of a cryptic promoter. These messages were present at low abundance in two cases of blastic crisis but were not detected in the chronic phase. It is conceivable that the proteins encoded by the new bcr-abl mRNAs are involved in the transformation to the acute phase in some cases of chronic myelogenous leukemia.
费城染色体阳性急性淋巴细胞白血病和慢性粒细胞白血病分别与两种不同形式的bcr-abl嵌合蛋白密切相关，这两种蛋白分别称为P190和P210。通过研究从细胞系KBM-5获得的cDNA克隆，我们鉴定出两种新的bcr-abl转录本。它们是由至少两个外显子与已知的bcr外显子2进行可变剪接形成的。一种新的转录本可以编码一种约190kd的蛋白激酶，而另一种则可以指导合成一种更大的蛋白，其氨基末端尚待确定。这些可变外显子也可以与两种正常的bcr转录本进行剪接，这反映了一个隐蔽启动子的激活。这些信息在两例急变期病例中低丰度存在，但在慢性期未检测到。可以想象，新的bcr-abl mRNA编码的蛋白质在某些慢性粒细胞白血病病例向急性期的转化中起作用。
