High-resolution genome-wide copy-number analysis suggests a monoclonal origin of multi-focal prostate cancer

ABSTRACT: Many human cancers present as multi-focal lesions. Understanding the clonal origin of multi-focal cancers is of both etiological and clinical importance. The molecular basis of multi-focal prostate cancer has previously been explored using only a limited number of isolated markers and, although independent origin is widely believed, the clonal origin of multi-focal prostate cancer is still debatable. We attempted to address clonal origin using a genome-wide copy-number analysis of individual cancer and high-grade prostatic intraepithelial neoplasia (HGPIN) lesions. Using Affymetrix array 6.0 copy-number analysis, we compared the genomic changes detected in 54 individual cancer and HGPIN lesions, isolated from 20 clinically localized prostate cancer cases. Identical genomic copy-number changes, shared by all same-case cancer foci, were detected in all 16 informative multi-tumor cases. In addition, both HGPIN lesions in the two multi-HGPIN cases available shared identical genomic changes. Commonly known genomic alterations, including losses at 6q15, 8p21.3-8p21.2, 10q23.2-10q23.31, 13q21.31-13q21.32, 16q22.3, 16q23.2-16q23.3 and 21q22.2-21q22.3 regions and gain of 8q24.3 were the most frequently detected changes in this multi-focal prostate cancer study, occurring in all same-case foci in at least one case. Microarray data were confirmed by fluorescence in situ hybridization in selected foci. Our high-resolution genome-wide copy-number data suggest that many multi-focal cases derive from a single prostate cancer precursor clone and that this precursor may give rise to separate HGPIN foci, which through clonal expansion may progress to multi-focal invasive prostate cancer. These findings, which demonstrate the monoclonal origin of multi-focal prostate cancer, should significantly enhance our understanding of prostate carcinogenesis and potentially improve clinical management of the disease. Copy number analysis of Affymetrix SNP 6.0 array was performed for a total of 48 cancer and HGPIN lesions from 18 prostate cancer cases. All samples have case-matched normal controls. PL = high grade PIN from left side, PR = high grade PIN from right side, PM = high grade PIN from middle of the tissue, TL = tumour from left side, TR = tumour from right side.

ORGANISM(S): Homo sapiens

SUBMITTER: Xueying Mao 

PROVIDER: E-GEOD-29569 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress