The microcell hybrid‐based “elimination test” identifies a 1‐Mb putative tumor‐suppressor region at 3p22.2–p22.1 centromeric to the homozygous deletion region detected in lung cancer

Abstract

We have previously shown that inoculation of human chromosome 3 (chr3)/A9 mouse fibrosarcoma microcell hybrids (MCHs) into severely combined immunodeficient (SCID) mice was followed by the regular elimination of certain 3p regions, whereas a 3q region was retained even after prolonged mouse passage. Using this approach, referred to as the elimination test (Et), we identified a common eliminated region (CER) of about 7 cM at 3p22-p21.3 that was absent in all tumors generated from five MCHs. A second frequently eliminated region (FER, originally called ER2) was found at 3p21.1-p14.2. These segments have been reported to be frequently deleted in a variety of carcinomas. In the following experiments, we have identified at the centromeric border of CER a common eliminated region 1 (CER1) of about 1.6 cM. We now report the results of more detailed analyses of the original tumor panel that contained 30 SCID mouse tumors. Using polymerase chain reaction and chromosome reverse painting, we have identified at the telomeric border of CER a second common eliminated region (designated as CER2). CER2 is flanked distally by RH94338 and proximally by SHGC-154057. The size of CER2 is about 1 Mb, according to the Homo Sapiens Complete Genome databases at EMBL, and is located about 0.5 Mb centromeric to the known homozygous deletion region, identified in lung cancer. Remarkably, two chemokine-receptor genes (CCRs), CCR8 and CX3CR1, are located within CER2, whereas seven CCRs were found within CER1.

Down regulation of 3p genes, LTF, SLC38A3 and DRR1, upon growth of human chromosome 3–mouse fibrosarcoma hybrids in severe combined immunodeficiency mice

“…This gene was disrupted by CER1 centromeric border in the SCID tumours of the first Et experiments. 13,48 Northern blot analysis produced a strong signal in heart and skeletal muscle and a weak signal in kidney. In our present RT-PCR analysis, the LRRC2 transcript was detected in normal human kidney, but not in any of the 5 RCC cell lines analyzed.…”

“…1). 7,[11][12][13] In the following experiments, additional to the 5 MCHs studied in the first round of Et, we introduced 3 A9-based monochromosomal MCHs that carried cytogenetically intact human chr3 from 3 different normal donors. From these MCHs, we obtained 9 SCID mouse tumours (3 from each hybrid) that, in contrast with 5 MCHs previously studied, 11,12 remained positive for all of the 120 3p-specific PCR-markers tested (''chr31'' tumours).…”

Search for unknown tumor‐antagonizing genes

“…CER2 was missing from all 30 analyzed tumors derived from five microcell hybrids (MCHs). Seven genes, Golgi peripheral membrane protein coding gene p65 (FLJ23443 or Q9BQQ3), AXIN1 up-regulated (AXUD1), chemokine (C-X3-C) receptor 1 (CX3CR1), chemokine (C-C motif) receptor 8 (CCR8), hypothetical protein FLJ20551 (FLJ20551) coding gene, laminin receptor 1 (LAMR1), and myelin-associated oligodendrocyte basic protein coding gene (MOBP), have been identified within CER2 (Kholodnyuk et al, 2002).…”

Coincidence of synteny breakpoints with malignancy-related deletions on human chromosome 3

“…Two more regions identified in our system (16,17) and four well characterized deletion hot-spot regions found in tumor biopsies and cell lines (6,7,18,19) are located at 3p12-22 (see Table 1, which is published as supporting information on the PNAS web site, www.pnas.org). Comparing human and mouse genomic sequences assembled by the Celera Discovery System, we found that CBRs localize preferentially within the tumorassociated deletions in this chromosomal segment.…”