Dataset Information

Evidence that molecular changes in cells occur before morphological alterations during the progression of breast ductal carcinoma.

ABSTRACT: INTRODUCTION: Ductal carcinoma in situ (DCIS) of the breast includes a heterogeneous group of preinvasive tumors with uncertain evolution. Definition of the molecular factors necessary for progression to invasive disease is crucial to determining which lesions are likely to become invasive. To obtain insight into the molecular basis of DCIS, we compared the gene expression pattern of cells from the following samples: non-neoplastic, pure DCIS, in situ component of lesions with co-existing invasive ductal carcinoma, and invasive ductal carcinoma. METHODS: Forty-one samples were evaluated: four non-neoplastic, five pure DCIS, 22 in situ component of lesions with co-existing invasive ductal carcinoma, and 10 invasive ductal carcinoma. Pure cell populations were isolated using laser microdissection. Total RNA was purified, DNase treated, and amplified using the T7-based method. Microarray analysis was conducted using a customized cDNA platform. The concept of molecular divergence was applied to classify the sample groups using analysis of variance followed by Tukey's test. RESULTS: Among the tumor sample groups, cells from pure DCIS exhibited the most divergent molecular profile, consequently identifying cells from in situ component of lesions with co-existing invasive ductal carcinoma as very similar to cells from invasive lesions. Additionally, we identified 147 genes that were differentially expressed between pure DCIS and in situ component of lesions with co-existing invasive ductal carcinoma, which can discriminate samples representative of in situ component of lesions with co-existing invasive ductal carcinoma from 60% of pure DCIS samples. A gene subset was evaluated using quantitative RT-PCR, which confirmed differential expression for 62.5% and 60.0% of them using initial and partial independent sample groups, respectively. Among these genes, LOX and SULF-1 exhibited features that identify them as potential participants in the malignant process of DCIS. CONCLUSIONS: We identified new genes that are potentially involved in the malignant transformation of DCIS, and our findings strongly suggest that cells from the in situ component of lesions with co-existing invasive ductal carcinoma exhibit molecular alterations that enable them to invade the surrounding tissue before morphological changes in the lesion become apparent.

SUBMITTER: Castro NP

PROVIDER: S-EPMC2614523 | biostudies-literature | 2008

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Evidence that molecular changes in cells occur before morphological alterations during the progression of breast ductal carcinoma.

Castro Nadia P NP Osório Cynthia A B T CA Torres César C Bastos Elen P EP Mourão-Neto Mário M Soares Fernando A FA Soares Fernando A FA Brentani Helena P HP Carraro Dirce M DM

Breast cancer research : BCR 20081017 5

<h4>Introduction</h4>Ductal carcinoma in situ (DCIS) of the breast includes a heterogeneous group of preinvasive tumors with uncertain evolution. Definition of the molecular factors necessary for progression to invasive disease is crucial to determining which lesions are likely to become invasive. To obtain insight into the molecular basis of DCIS, we compared the gene expression pattern of cells from the following samples: non-neoplastic, pure DCIS, in situ component of lesions with co-existing ...[more]

PMID: 18928525

Similar Datasets

Project description:To obtain insight into the molecular basis of ductal carcinoma in situ (DCIS) and its progression by infiltrating surrounding tissue, we have performed cellular-based gene expression analysis of pure DCIS and DCIS with co-existing invasive ductal carcinoma (IDC) and compared the histological and molecular aspects between these morphologically identical lesions seeking to find key genes involved in DCIS progression. For that, 30 samples were evaluated, 4 non-neoplastic (N), 5 pure DCIS, 11 DCIS with co-existing IDC (DCIS-IDC) and 10 IDC. All samples were laser capture microdissected and RNAs were amplified using T7-based methodology. Microarray technology was performed using a customized cDNA platform containing 4,608 human genes. To classify the 4 sample groups according to molecular similarity we performed comparisons of their general expression pattern using ANOVA test (pFDR<0,01) followed by Tukey´s test (fold>l2l). Among the 4 sample groups, as expected, non-neoplastic cells reported the most distinct gene expression pattern. However, among the 3 groups of neoplastic cells, in contrast to morphological aspects, pure DCIS had the most distinct expression profile when compared to the other lesions: DCIS-IDC and IDC. Additionally, by comparison among pure DCIS, DCIS-IDC and N, we identified 147 genes potentially involved in DCIS progression. Unsupervised hierarchical cluster based on expression profile of this gene-set could discriminate DCIS-IDC from 60% of pure DCIS samples. Keywords: disease state analysis Fresh-frozen human breast samples were retrieved from the Tumor Tissue Biobank of the Medical and Research Center - Hospital A. C. Camargo, São Paulo. This research was approved by Ethic Committee of the Medical and Research Center - Hospital A. C. Camargo under number 587/04 and a written informed consent signed by all participants. All patients had presented at least 5 years of follow-up. Thirty samples were evaluated, 4 non-neoplastic breast samples (MN), 5 pure DCIS (stage 0; DCIS-0), 11 DCIS with co-existing IDC (DCIS) and 10 IDC. The non-neoplastic samples were obtained from perilesional mammary specimens from patients submitted to resection of benign lesions. All cells types were laser capture microdissected using PixCell II LCM system (Arcturus Engineering, Mountain View, CA). The total RNA was extracted by using the PicoPureä RNA Isolation kit (Arcturus Engineering # KT0204). A two-round linear amplification procedure based on T7-driven amplification was carried out. Amplified RNA was then used in a transcriptase reverse reaction into cDNA in the presence of Cy3- or Cy5-labeled dCTP. HB4a normal luminal epithelial mammary cell line (O’Hare et al 1991) was amplified following the same protocol and used as reference for microarray hybridizations. Dye swap was performed for each sample analyzed and used as replicate samples. For the raw_data (lowess_data), see Web Link below.

Dataset Information

Evidence that molecular changes in cells occur before morphological alterations during the progression of breast ductal carcinoma.

Publications

Evidence that molecular changes in cells occur before morphological alterations during the progression of breast ductal carcinoma.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets