ABSTRACT: Assessment of tumor heterogeneity, as evidenced by gene expression profiles, pathway activation, and gene copy number, in patients with multifocal invasive lobular breast tumors [gene copy number]
Project description:Assessment of tumor heterogeneity, as evidenced by gene expression profiles, pathway activation, and gene copy number, in patients with multifocal invasive lobular breast tumors
Project description:Assessment of tumor heterogeneity, as evidenced by gene expression profiles, pathway activation, and gene copy number, in patients with multifocal invasive lobular breast tumors [gene expression]
Project description:Invasive lobular carcinoma (ILC) comprises approximately ~10-20% of breast cancers. In general, multifocal/multicentric (MF/MC) breast cancer has been associated with an increased rate of regional lymph node metastases. Tumor heterogeneity between foci represents a largely unstudied source of genomic variation in those rare patients with MF/MC ILC.
Project description:Invasive lobular carcinoma (ILC) comprises approximately ~10-20% of breast cancers. In general, multifocal/multicentric (MF/MC) breast cancer has been associated with an increased rate of regional lymph node metastases. Tumor heterogeneity between foci represents a largely unstudied source of genomic variation in those rare patients with MF/MC ILC.
Project description:The identification of genomic alterations occurring in neoplastic lesions provides insight into both lesion occurrence and disease progression. In this study we used microarray comparative genomic hybridization (CGH) to investigate genetic changes in atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS), as the presence of these lobular neoplastic lesions is an indicator of risk in the development of invasive breast cancer. DNA was extracted from microdissected archival breast tissue containing ALH or LCIS, lacking adjacent invasive carcinoma, and subjected to whole-genome tiling path microarray-CGH using the submegabase resolution tiling set (SMRTr)-array platform. Twelve ALH and 13 LCIS lesions were examined. Copy number alterations were identified using statistical criteria and validated with Real-Time PCR and fluorescence in situ hybridization. From statistical analysis, a greater number of alterations were observed in ALH compared to LCIS. Alterations common to ALH include gain at 2p11.2 and loss at 7p11.2-p11.1 and 22q11.1. Alterations common to LCIS include gain at 20q13.13 and loss at 19q13.2-q13.31. In both ALH and LCIS, we observed loss of 16q21-q23.1, an altered region previously identified in lobular neoplasia and invasive carcinoma. The validation of select alterations reinforces the genomic signature. This study represents the first whole-genome investigation of lobular neoplastic breast lesions using clinical archival specimens. The identified genomic signature includes copy number alterations not previously identified for lobular neoplasia. This genomic signature, common to ALH and LCIS, suggests a role for the acquisition of novel genomic alterations in the aberrant cellular proliferation that defines lobular neoplasia. Keywords: comparative genomic hybridization, high resolution analysis of atypical lobular hyperplasia (ALH) and lobular carcinoma in situ (LCIS) human archival breast lesions by whole genome tiling path array CGH
Project description:<p>This study comprises prospectively accrued, microdissected fresh frozen samples of multifocal lobular carcinoma <i>in situ</i> (LCIS), ductal carcinoma <i>in situ</i> (DCIS), invasive lobular carcinoma and invasive ductal carcinoma from patients undergoing prophylactic or therapeutic mastectomies after a diagnosis on LCIS diagnosed and managed at Memorial Sloan Kettering Cancer Center (MSKCC). Microdissected samples were subjected to paired-end whole exome sequencing on an Illumina HiSeq 2000. The data generated were used to define the landscape of somatic genetic alterations of LCIS, DCIS, invasive lobular carcinoma and invasive ductal carcinoma, to define clonal relatedness of these lesions and to investigate the clonal shifts in the progression from <i>in situ</i> to invasive breast cancer.</p>
Project description:Copy number assessment of chromosome 1 in astrocytic tumors using a chromosome 1 tile path array. Goal was to determine the patterns of chromosome 1 copy number alterations in astrocytic tumors. Keywords: Comparative Genomic Hybridization
Project description:Copy number assessment of chromosome 1 in astrocytic tumors using a chromosome 1 tile path array. Goal was to determine the patterns of chromosome 1 copy number alterations in astrocytic tumors. Keywords: Comparative Genomic Hybridization
Project description:Tumors acquire somatic DNA copy number aberrations, leading to activation of oncogenes and inactivation of tumor suppressors. Many studies have focused on the analysis of single copy number aberrations and associated driver genes, but few studies have performed combinatorial analyses. We propose a genome-wide scoring framework to find mutually exclusive gains and losses. Mutually exclusive copy number aberrations can identify genes whose oncogenic function is redundant, either by functioning in the same pathway or in a parallel pathway. As one gene is aberrated the selective pressure for its partner is alleviated which leads to a mutually exclusive perturbation pattern. In a dataset of mouse models for invasive lobular carcinoma we found three mutually exclusive DNA amplifications, containing several well-known oncogenes: the Met proto-oncogene on chromosome 6, the cluster of Birc2, Birc3 and Yap1 genes on chromosome 9, and Nras on chromosome 3. Furthermore, gene expression or protein expression of these genes correlates very well with copy number data indicating that they are the target of the amplification. Although homologous amplifications in human tumors are rare, the mutual exclusivity of MET, BIRC/YAP1 and NRAS is maintained in a variety of cancer types. This suggests a novel function for YAP1 in the mitogen-activated signaling pathway by association with MET and NRAS, known players in this pathway. This function is independent to the propensity of YAP1 to cause Epithelial-to-Mesenchymal transition. aCGH data of 67 mouse mammary tumors from K14-Cre and WAP-Cre driven P53-F/F;Cdh1-F/F animals - tumor DNA hybridized against same-animal splenic DNA
