Neoplastic progression of breast epithelial cells - a molecular analysis (original) (raw)
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Cloning of novel mammary tumor progression and metastasis genes
Breast Cancer Research, 2001
Background: Disruption of the balance between apoptosis and proliferation is considered to be an important factor in the development and progression of tumor. In this study we determined the in vivo cell kinetics along the spectrum of apparently normal epithelium, hyperplasia, preinvasive lesions and invasive carcinoma, in breast tissues affected by fibrocystic changes in which preinvasive and/or invasive lesions developed, as a model of breast carcinogenesis. Materials and method: A total of 32 areas of apparently normal epithelium and 135 ductal proliferative and neoplastic lesions were studied. More than one epithelial lesion per case was analyzed. The apoptotic index (AI) and the proliferative index (PI) were expressed as the percentage of TUNEL (TdT-mediated dUTP-nick end-labelling) and Ki-67 positive cells, respectively. The proliferative/apoptotic index (P/A) was calculated for each case. Results: Statistical analysis demonstrated significant differences among the tissue groups for both indices (P < 0.0001). The Als and PIs were significantly higher in hyperplasia than in apparently normal epithelium (P = 0.04 and P = 0.0005, respectively), in atypical hyperplasia than in hyperplasia (P = 0.01 and P = 0.04, respectively) and in invasive carcinoma than in in situ carcinoma (P = 0.0001 and P < 0.0001, respectively). The two indices were similar in atypical hyperplasia and in in situ carcinoma. The P/A index increased significantly from normal epithelium to hyperplasia (P = 0.01) and from preinvasive lesions to invasive carcinoma (P = 0.04), whereas it was decreased (NS) from hyperplasia to preinvasive lesions. A strong positive correlation between the Als and the Pls was found (r = 0.83; P < 0.0001). Conclusion: These findings suggest accelerating cell turnover along the continuum of breast carcinogenesis. Atypical hyperplasias and in situ carcinomas might be kinetically similar lesions. In the transition from normal epithelium to hyperplasia and from preinvasive lesions to invasive carcinoma, the net growth of epithelial cells results from a growth imbalance in favour of proliferation. In the transition from hyperplasia to preinvasive lesions there is an imbalance in favour of apoptosis.
Differential characteristics of two new tumorigenic cell lines of human breast carcinoma origin
International Journal of Cancer, 1998
Permanent human tumor cell lines are an important tool for the study of breast cancer. Two new breast cancer cell lines (BrCa-MZ-01 and BrCa-MZ-02) were isolated from a solid tumor and a pleural effusion, respectively. One cell line was established from a medullary carcinoma, the other from a ductal carcinoma. These cells exhibit ultrastructural and immunohistochemical features of epithelial cells of mammary origin. Intermediate filament and cytokeratin typing showed a clear predominance of the simple-epithelial cytokeratins CK 8, CK 18 and CK 19, although the expression was reduced in comparison to the hormone receptor-positive reference cell lines MCF-7 and ZR-75-1. Both cell lines produced slow-growing tumors after subcutaneous (s.c.) transplantation of 1 ؋ 10 7 viable tumor cells into nude mice. The cell line BrCa-MZ-01 expresses the estrogen and progesterone receptor, whereas the cell line BrCa-MZ-02 remains negative. Both cell lines are positive for secretion of plateletderived growth factor (PDGF) and transforming growth factor- (TGF-), whereas interleukin-6 (IL-6) is only secreted by the cell line BrCa-MZ-02. Int.
Gene expression abnormalities in histologically normal breast epithelium of breast cancer patients
International Journal of Cancer, 2007
The gene expression profile of breast cancer has been described as a great breakthrough on the way to comprehend differences in cancer origin, behavior and therapy. However, gene expression profile in histologically normal epithelium (HNEpi) which could harbor genetic abnormalities predisposing breast tissue to develop malignancy was minor scope for scientists in the past. Thus, we aimed to analyze gene expressions in HNEpi and breast cancer tissue (BCTis) in order to establish its value as potential diagnostic marker for cancer development. We evaluated a panel of disease-specific genes in luminal type (A/B) of breast cancer and tumor surrounding HNEpi by qRT-PCR Array in 32 microdissected samples. There was 20.2 and 2.4 % deregulation rate in genes with at least 2-fold or 5-fold over-expression between luminal (A/B) type breast carcinomas and tumor surrounding HNEpi, respectively. The high-grade luminal carcinomas showed higher number of deregulated genes compared to lowgrade cases (50.6 vs. 23.8 % with at least 2-fold deregulation rate). The main overexpressed genes in HNEpi were KLK5, SCGB1D2, GSN, EGFR and NGFR. The significant differences in gene expression between BCTis and HNEpi samples were revealed for BAG1,
Functional characterization of genes involved in the development of breast cancer
2005
There is compelling evidence from transgenic mouse studies and analysis of mutations in human carcinomas indicating that the TGF-β signal transduction pathway is tumor suppressive. We have shown that overexpression of TGF-β1 in mammary epithelial cells suppresses the development of carcinomas and that expression of a dominant negative type II TGF-β receptor (DNIIR) in mammary epithelial cells under control of the MMTV promoter/enhancer increases the incidence of mammary carcinomas. Studies of human tumors have demonstrated inactivating mutations in human tumors of genes encoding proteins involved in TGF-β signal transduction, including DPC4/Smad4, Smad2, and the type II TGF-β receptor (TβRII). There is also evidence that TGF-β can enhance the progression of tumors. This hypothesis is being tested in genetically modified mice. To attain complete loss of TβRII, we have generated mice with loxP sites flanking exon 2 of Tgfbr2 and crossed them with mice expressing Cre recombinase under control of the MMTV promoter/enhancer to obtain Tgfbr2 mgKO mice. These mice show lobuloalveolar hyperplasia. Mice are being followed for mammary tumor development. Tgfbr2 mgKO mice that also express polyoma virus middle T antigen under control of the MMTV promoter (MMTV-PyVmT) develop mammary tumors with a significantly shorter latency than MMTV-PyVmT mice and show a marked increase in pulmonary metastases. Our data do not support the hypothesis that TGF-β signaling in mammary carcinoma cells is important for invasion and metastasis, at least in this model system. The importance of stromal-epithelial interactions in mammary gland development and tumorigenesis is well established. These interactions probably involve autocrine and paracrine action of multiple growth factors, including members of the TGF-β family, which are expressed in both stroma and epithelium. Again, to accomplish complete knockout of the type II TGF-β receptor gene in mammary stromal cells, FSP1-Cre and Tgfbr2 flox/flox mice were crossed to attain Tgfbr2 fspKO mice. The Despite over a decade of scrutiny and over 20 published reports from various countries, the degree to which ATM mutations lead to breast References 1. Gatti RA, Tward A, Concannon P: Cancer risk in ATM heterozygotes: a model of phenotypic and mechanistic differences between missense and truncating mutations. Mol Biol Metab 1999, 68:419-423. 2. Spring K, Ahangari F, Scott SP, Waring P, Purdie DM, Chen PC, Hourigan K, et al.: Mice heterozygous for mutation in Atm, the gene involved in ataxia-telangiectasia, have heightened susceptibility to cancer. Nat Genet 2002, 32:185-190. 3. Scott SP, Bendix R, Chen P, Clark R, Dork T, Lavin MF: Missense mutations but not allelic variants alter the function of ATM by dominant interference in patients with breast cancer. Proc Natl Acad Sci USA 2002, 99:925-930. 4. Concannon P: ATM heterozygosity and cancer risk. Nat Genet 2002, 32:89-90. 5. Chenevix-Trench G, Spurdle AB, Gatei M, Kelly H, Marsh A, Chen X, Donn K, et al.: Dominant negative ATM mutations in breast cancer families.
The gene expression profile of breast cancer has been described as a great breakthrough on the way to comprehend differences in cancer origin, behavior and therapy. However, gene expression profile in histologically normal epithelium (HNEpi) which could harbor genetic abnormalities predisposing breast tissue to develop malig-nancy was minor scope for scientists in the past. Thus, we aimed to analyze gene expressions in HNEpi and breast cancer tissue (BCTis) in order to establish its value as potential diagnostic marker for cancer development. We evaluated a panel of disease-specific genes in luminal type (A/B) of breast cancer and tumor surrounding HNEpi by qRT-PCR Array in 32 microdissected samples. There was 20.2 and 2.4 % deregulation rate in genes with at least 2-fold or 5-fold over-expression between luminal (A/B) type breast carcinomas and tumor surrounding HNEpi,
Molecular Portrait of the Normal Human Breast Tissue and Its Influence on Breast Carcinogenesis
Journal of Breast Cancer, 2016
Recent studies have shown that normal breast tissue is composed of epithelial and nonepithelial cells with different profiles reflecting their maturation and differentiation [1]. In addition, cells of normal mammary tissue are known to yield abnormal clones that may contribute to the development of both preneoplastic and tumor lesions [2-4]. It appears that epithelial cells of the normal breast exhibit a heterogeneous profile depending on their differentiation stage. Considering these facts, several reports have referred to the existence of two luminal phenotypes and two basal phenotypes, based on differential immunohistochemical profiles [1]. These cells are known to express CD24, CD49f, and the epithelial cell adhesion molecule Epithelial cell adhesion molecule (EpCAM) [1]. Luminal progenitor cells, of normal breast tissue, express both CD49f and EpCAM while their mature variants do not express CD49f [1]. Myoepithelial cells, along with basal progenitor cells, lack EpCAM expression [1]. Both mature luminal cells and progenitor cells express CD44 and CD24 [1]. Based on cytokeratin (CK) 14 and CK19 expression in normal breast tissue, it appears that the normal mammary gland contains multipotent cells. These cells are located in the ducts,
Cancer Research
The expression of genes which may be involved in the regulation of human mammary epithelial cell growth [transforming growth factors a and /¡] and tumorigenesis |r-m»r, erbE2, epidermal growth factor receptor (EGFR), I hi-ri/v, pS2\ has been compared in similarly cultured normal cell strains and tumor cell lines. We have found that the normal breast cells produce high levels of EGFR mRNA, which are translated into nearly 10* low affinity epidermal growth factor-binding molecules/cell. In the estrogen receptor-negative lines examined, the EGFR gene was expressed at levels comparable to those in the normal cells. In contrast, EGFR and transforming growth factor a mRNAs were reduced in estro gen receptor-positive tumor lines compared to estrogen receptor-negative lines and normal cells. Steady state mRNA levels for transforming growth factor ft. erbB2, c-myc, and I la-ruv in the normal cells were greater than or comparable to those in all of the breast tumor lines. Furthermore, in the absence of gene amplification, only one of the genes examined (i.e., pS2) was overexpressed in a subset of the tumor cells compared to their normal counterparts. Several reports by other investigators have de scribed overexpression of some of these genes in breast biopsies and in tumor lines in studies lacking normal controls. Thus, our results, in which the same genes were not overexpressed compared to normal cells unless amplified, underscore the importance of including appropriate normal controls in studies aimed at defining aberrant patterns of gene expression in tumor cells.
Molecular profiles of invasive mucinous and ductal carcinomas of the breast
Cancer Genetics and Cytogenetics, 2003
Expression profiling using cDNA microarrays have redefined the molecular classification of some cancers. The comprehensive genetic analysis also permits the identification of novel pathways that might determine subtle differences in tumor phenotype. Herein, we analyzed the tissues from a patient with bilateral cancer of different histologies in each breast (pure invasive mucinous and pure invasive ductal), thus providing a unique opportunity to assess the expression profiles determined by histology in an isogenic human background. Our results show that the mucinous phenotype is associated with the expression of immunostimulatory and inhibitory genes, consistent with the cellular infiltration of lymphocytes and with the expression of enzymes involved in mucin production. Moreover, the panel of matrix metallo-proteinases are distinctly different between the mucinous and the invasive tumors, suggesting that therapeutic targets to this class of compounds may need to be tailored for the varying histologies. Taken together, these data suggest that expression profiling can be used diagnostically to distinguish individual histologic subclassifications and may guide the selection of target therapeutics.