Ohno S, Takahashi R, Mihara K, Chen H L, Migita S, Sugiyama T
Department of Molecular Immunology, kanazawa University, Japan.
Int J Cancer. 1988 Apr 15;41(4):595-600. doi: 10.1002/ijc.2910410420.
Cells from murine plasmacytomas (MPC) consistently exhibit either the 12;15 or the 6;15 translocation. Recently, we found that cells from 2 MPC (ABPC 45 and ABPC 26) did not exhibit any known translocation. However, these MPC contained one chromosome 15 (15q-) that was shorter than its normal homologue and one 12 (12q+) that was longer than its normal 12 counterpart. Chromosome 15q- contained only one thin D band, corresponding in size to either D1 or D3 band. A minor light band D2 was apparently deleted. Chromosome 12q+ contained a light F1 band that was longer than the normal 12F1. In ABPC 45, the c-myc gene was assigned by in situ hybridization to the F1 region of 12q+ as well as to its original site of 15D2. Moreover, the in situ hybridization experiment assigned the S alpha gene to the F1 regions of both chromosomes 12 and 12q+. These findings indicate that a minor light band D2 of chromosome 15 carrying the c-myc gene was translocated into the major light band F1 of 12, resulting in a longer chromosome 12q+ and a correspondingly shorter chromosome 15q-. This type of chromosomal translocation suggests that ABPC 45 developed through a cytogenetic mechanism different from that of MPC with the typical t(12;15) translocation.
来自鼠浆细胞瘤（MPC）的细胞始终表现出12;15或6;15易位。最近，我们发现来自2个MPC（ABPC 45和ABPC 26）的细胞未表现出任何已知的易位。然而，这些MPC包含一条比其正常同源染色体短的15号染色体（15q-）和一条比其正常12号对应染色体长的12号染色体（12q+）。15q-染色体仅包含一条细的D带，其大小与D1或D3带相对应。一条较小的轻带D2明显缺失。12q+染色体包含一条比正常12F1长的轻带F1。在ABPC 45中，通过原位杂交将c-myc基因定位到12q+的F1区域以及其原来的15D2位点。此外，原位杂交实验将Sα基因定位到12号染色体和12q+染色体的F1区域。这些发现表明，携带c-myc基因的15号染色体的一条较小轻带D2易位到了12号染色体的主要轻带F1中，导致12q+染色体更长，相应地15q-染色体更短。这种类型的染色体易位表明，ABPC 45是通过一种与具有典型t(12;15)易位的MPC不同的细胞遗传学机制发展而来的。
