Report of the first international workshop on human chromosome 8 mapping. Final report

Loss of heterozygosity (LOH) from the short arm of chromosome 8 (8p) is common to many human carcinomas, including those of the colon and prostate. It localizes to two discrete regions, 8p21 and 8p22. This suggests the presence of at least two tumor suppressor genes (TSGs) on this chromosome arm. Human breast cancers show consistent 8p deletions in cytogenetic studies, chromosome 8 aneusomy and isochromosome 8q, indicating that the relevant gene(s) may play a role, but the results of molecular analyses of chromosome 8 in breast cancer have been variable. We present here data for 8p LOH in an unselected series of human breast cancers with the use of three CA-repeat markers that showed high rates of LOH in other tumors. All cases were informative for at least one marker, and LOH was seen in 11 of 20 cases (55%). LOH was more frequent for the 8p22 markers D8S254 and D8S133 than for NEFL in 8p21. Regional metastases of the tumors showed allele profiles identical to those of their primaries regardless of whether there was LOH or retention of alleles. One case of microsatellite instability (RER+) was seen. LOH did not correlate with receptor status, ploidy, percentage of cells in S phase, or tumor size: We observed LOH at equal rates in small (< 2 cm) and in larger (> 2 cm) tumors. The data suggest that LOH from 8p is frequent in human breast cancers and that loss of the putative 8p TSG may be an important event in early stage breast cancer.

Section: Methodsmentioning

confidence: 99%

Loss of heterozygosity from the short arm of chromosome 8 is an early event in breast cancers

Yarernko

Recant

Westbrook

1995

“…Tumor DNA for PCR amplification was obtained from multiple 10 pm cryosections after trimming of nonneoplastic areas from the cut face of frozen tumor blocks. DNA was prepared as described previously (Bookstein et al, 1993), except that deparaffinization steps were skipped. In all, 63 tumor/ benign pairs were accepted based on the availability of PCR-amplifiable DNA from tumor tissue with > 50% neoplastic cell content and from benign tissue; most cases also yielded sufficient tumor DNA for Southern analysis.…”

Section: Materials and M E T H O D S Tissue Samples And Dna Preparationmentioning

confidence: 99%

“…DNA probes for RFLP polymorphisms were obtained from the American Type Culture Collection (pSW50 and pHNF-L) or from investigators' laboratories (Table 2). All genetic loci except CTSB have been placed in one or more published linkage or physical maps, as summarized by Wood et al (1993), and the consensus order for these loci was adopted here. We obtained further order information by assigning some loci to chromosomal intervals defined by a well-characterized panel of human-hamster somatic cell hybrids (Wagner et al, 1991).…”

Section: Origin and Order Of Chromosome 8 Markersmentioning

confidence: 99%

Loss of chromosome arm 8p loci in prostate cancer: Mapping by quantitative allelic imbalance

MacGrogan¹,

Levy²,

Bostwick

et al. 1994

163

A previous study of 18 primary or metastatic prostate cancers showed loss of genetic markers on chromosome 8; 10, or 16 in more than 50% of cases [Bergerheim USR et al. (1991) Genes Chromosom Cancer 3:215-220]. The small size and infiltrative nature of primary prostatic tumors have hindered efforts to assess allelic losses by traditional restriction fragment length polymorphism (RFLP)/Southern blotting methods. To improve the sensitivity and specificity of this analysis in early prostate cancer, we have amplified polymorphic microsatellite repeats by polymerase chain reaction (PCR), and have quantitated allelic imbalances with phosphor imaging technology. In this study, 63 primary prostate tumors and matched benign tissues obtained by radical prostatectomy were examined at 28 genetic loci on chromosome 8, all but five of which were located on the short arm. Twenty-nine (46%) of the 63 cases showed loss of at least one locus. Multiple adjacent loci, usually including the LPL and MSR genes in 8p22, were lost in 28 cases. In 10 of these, losses were observed at all informative loci on the p arm. In another 15 tumors, losses were restricted to subregions of the p arm by loci retained either distally toward the p terminus or proximally at the 8p12-8p21 border, or both. In three tumors, two discrete regions of loss were observed within 8p, separated by several retained loci. Allelic loss of 8p loci was associated with higher tumor grade. These data are complementary to previous reports of allelic deletions in colorectal, hepatocellular, and non-small cell lung cancers and suggest the existence of one or more pleotropic tumor suppressor genes on 8p.

“…To this end, we applied CGH to a series of prostate cancer DNAs that had been (MacGrogan et al, 1994). Chromosomal intervals A-I as determined from a panel of somatic cell hybrids (Wagner et al, 1991;Wood et al, 1993) are shown separated by thin lines. The numbers associated with loci refer to the D8S name.…”

Section: Introductionmentioning

confidence: 99%

Comparative genomic hybridization, allelic imbalance, and fluorescence in situ hybridization on chromosome 8 in prostate cancer

Cher

Bookstein²,

Brown

et al. 1994

174

101

Due to problems with primary tumor cell culture, conventional cytogenetics has yielded little insightful information on chromosomal alterations in prostate cancer. The primary aim of this study was to define the ability of comparative genomic hybridization (CGH) to detect and map genetic deletions in prostate tumors. A secondary aim was to apply multiple assays to individual tumors as a means of deciphering the mechanisms of genetic alterations in prostate cancer. CGH results were compared with allelic imbalance measurements at 29 distinct loci on chromosome 8 in 18 specimens (17 malignant and 1 benign). CGH detected no changes in cases where all informative PCR/RFLP loci were retained and detected all p arm deletions consisting of at least two loci. We estimate that in this study, the smallest deletions detected by CGH were approximately 20-30 cM. Physical mapping of subchromosomal arm deletions by CGH correlated well with allelic imbalance mapping by PCR/RFLP: The data agreed at 88% of loci on 8p and 92% of loci on 8q. Fluorescence in situ hybridization (FISH) with multiple centromere probes and DNA content flow cytometry (FCM) also was performed on selected specimens. FISH revealed two cases of chromosome 8 aneusomy. In these two cases and three others, CGH showed simultaneous p arm deletion and q arm gain, suggesting isochromosome 8q formation. Together, these data suggested that, simple chromosomal aberrations were responsible for allelic losses on 8p and allelic gains on 8q in a significant number of prostate tumors. We also used CGH to examine relative DNA sequence copy number throughout the genome. Changes frequently associated with 8p loss include gains of 8q and losses of 13q, 16p, 16q, 17p, 17q, 20q, and Y. Cases with 8p loss exhibited five times the number of alterations as did cases without 8p loss.