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:The aim of our study was to identify gene expression profiles of ductal and lobular carcinomas in relation to normal ductal and lobular cells. We examined ten mastectomy specimens from postmenopausal breast cancer patients. Ductal and lobular tumor and normal cells were microdissected from cryosections. Fifty nanograms of total RNA were amplified and labeled by PCR and in vitro transcription. GCOS pairwise comparison algorithm and rank products have identified multiple genes that are differentially expressed in comparisons between ductal and lobular tumor and normal cell types. The results suggest that these genes are involved in epithelial-mesenchymal transition, TGFbeta and Wnt signaling. These changes are present in both tumor types but appear to be more prominent in lobular carcinomas. Ten surgical specimens obtained by mastectomy from postmenopausal patients with invasive ductal (IDC) and lobular breast (ILC) carcinomas were investigated. Of these, 5 were IDCs and 5 were ILCs. Tumor and normal tissues from the same mammary gland were identified by an experienced pathologist, snap-frozen in liquid nitrogen and stored at -80ºC for further analysis. Microdissection, RNA isolation, amplification, labeling and microarray analysis are described in sample definitions. Samples from particular cell types (normal ductal, normal lobular, tumor ductal, tumor lobular - 10, 10, 5, 5 samples, respectively) were considered as biological replicates and were compared in between.
Project description:Low grade flat ductal intraepithelial neoplasia (DIN1a, flat epithelial atypia) is one of the earliest morphologically recognizable neoplastic lesions of the breast. Frequently, it occurs in association with lobular intraepithelial neoplasia (LIN). The aim of this study was to elucidate chromosomal aberrations in these early neoplastic breast lesions using array comparative genomic hybridization (CGH) analysis. Laser capture microdissection of 12 archival formalin-fixed, paraffin-embedded specimens harbouring both foci of DIN1a as well as LIN was performed. All analyzed cases of DIN1a and LIN showed chromosomal gains and losses. The aberration encountered most often was loss on 16q in 7 DIN1a (70%) and 10 LIN (91%) cases. Regarding changes in chromosome 1, four DIN1a (40%) and 7 LIN (64%) cases showed a gain on 1q. The results of our study show concurrent chromosomal aberrations of 1q gains and 16q losses in several cases with coexisting LIN and low grade flat DIN. These aberrations are known to be common in low grade invasive ductal carcinomas as well as more advanced (conventional) types of low grade DIN (low grade ductal carcinoma in-situ). Our results raise the possibility of similar molecular-genetic pathways in most of the cases with coexisting LIN and low grade flat DIN.
Project description:The aim of our study was to identify gene expression profiles of ductal and lobular carcinomas in relation to normal ductal and lobular cells. We examined ten mastectomy specimens from postmenopausal breast cancer patients. Ductal and lobular tumor and normal cells were microdissected from cryosections. Fifty nanograms of total RNA were amplified and labeled by PCR and in vitro transcription. GCOS pairwise comparison algorithm and rank products have identified multiple genes that are differentially expressed in comparisons between ductal and lobular tumor and normal cell types. The results suggest that these genes are involved in epithelial-mesenchymal transition, TGFbeta and Wnt signaling. These changes are present in both tumor types but appear to be more prominent in lobular carcinomas. Keywords: cell type comparison
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:Lobular intraepithelial neoplasia grade 3 (LIN) is a recently recognized variant of intraepithelial lobular neoplasia of the breast composed of either uniform, generally small, cells (classic) with massive lobular distension, pleomorphic cells, signet-ring cells, or any cell type with necrosis. In contrast to classic forms of LIN, there is no consensus on therapeutic strategies for LIN3. In part this is due to the paucity of molecular data that could assist in defining the relationship of LIN3 to classic LIN and carcinomas. In this study we have employed array CGH to determine the patterns of chromosomal aberrations in 9 LIN3 lesions. By comparison to array CGH data of 13 classic LIN lesions, we demonstrate that LIN and LIN3 share several recurrent changes, in particular gains of 1q and losses of 16q. Both aberrations are known to appear early in tumorigenesis and to be associated with good prognosis. However, apart from this overlap, there were a number of karyotypic features that were observed exclusively in LIN3. Clearly, this lesion was characterized by a significantly higher number of DNA copy number changes (9 vs. 31 on average), a considerable complexity of chromosomal rearrangements with up to 16 breakpoints in one chromosome and overlapping high copy amplifications. The amplicons encompassed a number of known oncogenes such as ERBB2, CyclinD1 and FGF3 that have already been reported to be overexpressed in breast carcinomas. Our data suggest that, at the genetic level, LIN3 represents a highly advanced lesion with considerable resemblance to carcinomas and, therefore, reflects a lesion on the verge of invasion, and might represent the transition state from an intraepithelial neoplasm to breast carcinoma.
Project description:Gene expression array analysis on a series of ten different histological special types of invasive breast carcinomas (tubular, micropapillary, mucinous A, mucinous B, endocrine, apocrine, metaplastic, medullary, adenoid cystic, invasive ductal carcinoma with osteoclastic giant cells) and invasive lobular carcinoma.<br><br>Note: this experiment was reloaded into ArrayExpress in August 2010 to include mappings between raw and processed data files. It now includes additional dye-swap combined normalized data files.