Differentially expressed genes and estrogen receptor status in breast cancer

Nagai, María Aparecida; Rós, Nancy da; Bessa, Simone Aparecida; Neto, Mário Mourão; Miracca, Elisabete; Brentani, Maria Mitzi

doi:10.3892/ijo.23.5.1425

Cited by 11 publications

(15 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[37][38][39] Previous data from our group identified Seladin-1 gene transcripts in ER Ϫ /PR Ϫ primary breast tumors using differential display reverse transcriptase (DDRT)-PCR. 40 In the present study, we have also observed that advanced-stage breast tumors (stages III and IV) showed higher levels of Seladin-1 gene expression compared to early-stage breast tumors (stages I and II), possibly reflecting its association with a more aggressive nature. Seladin-1 encodes for a protein with homology with a family of FAD-dependent oxireductases, which play a role in cholesterol biosynthesis.…”

Section: Resultssupporting

confidence: 75%

Gene expression profiles in breast tumors regarding the presence or absence of estrogen and progesterone receptors

Nagai

Rós

Neto

et al. 2004

Intl Journal of Cancer

View full text Add to dashboard Cite

Estrogen acts via its receptor (ER) to stimulate cell growth and differentiation in the mammary gland. ER and progesterone receptor (PR), which is regulated by estrogen via ER, have been used as prognostic markers in clinical management of breast cancer patients. Patients with ER ؊ breast tumors have a poorer prognosis than patients with ER ؉ tumors. The aim of the present study was the identification of tumor-associated genes differentially expressed in breast tumors regarding the presence or absence of ER and PR hybridized with cDNA microarrays containing 4,500 tumorderived expressed sequence tags generated using the ORESTES technique. Samples of human primary breast carcinomas from 38 patients were analyzed. The experiments were performed in triplicates and data from each element were acquired by phosphoimage scanning. Data acquisition was performed using the ArrayVision software. After normalization statistical analysis was applied. In a preliminary analysis, 98 differentially expressed transcripts were identified, 46 were found to be more expressed in ER ؉ /PR ؉ and 52 were found to be more expressed in ER ؊ /PR ؊ breast tumors. Estrogens exert important roles in the development, differentiation and maintenance of several target tissues and are also associated with the development and growth of hormone-dependent tumors such as breast cancer. 1 Most estrogen actions are thought to be mediated through its nuclear estrogen receptors, ER␣ and ER␤, which are members of the nuclear receptors superfamily that are ligand-induced transcription factors. 2 The mechanism by which estrogen receptor (ER) mediates the transactivation of gene expression is complex. 3 Besides the classical ligand-dependent mechanism of ER action in which the hormone-receptor complex regulates gene transcription through its interaction with ERE consensus DNA sequences, the ERs can also regulate gene transcription interacting with other promoter elements such as AP1, 4 SP1 5 and CREs. 6 Thus, estrogen receptors ER␣ and ER␤ can transduce different hormonal signals depending on the ligand and the nature of the hormone-responsive element (HRE). 2 The transactivation elicited by those receptors complexed with E2 may result in opposite signal transduction leading to opposite biologic response in the presence of AP1 and/or CRE sites. 7,8 In addition, several E2-responsive genes are regulated by DNA-independent or -dependent interactions of the ER␣ and SP1 proteins. 9 Alternatively, the signal transduction by growth factors and their tyrosine kinase receptors, such as EGFR, IGFR, erbB-2 and other molecules like cAMP and dopamine, may lead to a ligand-independent ER activation, resulting from the phosphorylation of serine and tyrosine amino acid residues in the AF1 and AF2 domains in the estrogen receptor molecule. 10

show abstract

Section: Resultssupporting

confidence: 75%

Gene expression profiles in breast tumors regarding the presence or absence of estrogen and progesterone receptors

Nagai

Rós

Neto

et al. 2004

Intl Journal of Cancer

View full text Add to dashboard Cite

show abstract

“…Neef and co-workers (13) also showed that down-regulation of PHLDA1 expression is associated with the progression of malignant melanomas. PHLDA1 transcripts were also identified as being downregulated in primary breast tumors compared to normal breast tissue (9). More recently, using immunohistochemistry in tissue microarray containing a large series of samples, we demonstrated that PHLDA1 expression is frequently down-regulated in primary breast tumors and that the expression of PHLDA1 irrespective of ER positivity is a marker of good prognosis in primary breast tumors (14).…”

mentioning

confidence: 84%

“…Using the differential display reverse transcription-polymerase chain reaction technique, our group identified several genes differentially expressed in primary breast tumors regarding the presence or absence of ER and progesterone receptor, and a set of genes differentially expressed in normal and tumor tissues regardless ER status (9). One of the genes found to be down-regulated in breast tumors compared to normal breast tissue was the PHLDA1 (Pleckstrin homology-like domain, family A, member 1).…”

mentioning

confidence: 99%

Transcriptional up-regulation of PHLDA1 by 17β-estradiol in MCF-7 breast cancer cells

Marchiori

Casolari

Nagai

2008

Braz J Med Biol Res

View full text Add to dashboard Cite

Most breast cancer risk factors are associated with prolonged exposure of the mammary gland to high levels of estrogens. The actions of estrogens are predominantly mediated by two receptors, ERα and ERß, which act as transcription factors binding with high affinity to estrogen response elements in the promoter region of target genes. However, most target genes do not contain the consensus estrogen response elements, but rather degenerated palindromic sequences showing one or more mutations and other ER-binding sites such as AP-1 and SP-1. Using the differential display reverse transcription-polymerase chain reaction technique, our group identified several genes differentially expressed in normal tissue and in ER-positive and ER-negative primary breast tumors. One of the genes shown to be down-regulated in breast tumors compared to normal breast tissue was the PHLDA1 (Pleckstrin homology-like domain, family A, member 1). In the present study, we investigated the potential of PHLDA1 to be regulated by estrogen via ER in MCF-7 breast cancer cells. The promoter region of PHLDA1 shows an imperfect palindrome, an AP-1-and three SP-1-binding sites potentially regulated by estrogens. We also assessed the effects of 17ß-estradiol on PHLDA1 mRNA expression in MCF-7 breast cancer cells. MCF-7 cells exposed to 10 nM 17ß-estradiol showed more than 2-fold increased expression of the PHLDA1 transcripts compared to control cells (P = 0.05). The anti-estrogen ICI 182,780 (1 µM) inhibited PHLDA1 mRNA expression and completely abolished the effect of 10 nM 17ß-estradiol on PHLDA1 expression (P < 0.05), suggesting that PHLDA1 is regulated by estrogen via ER.

show abstract

“…Além disso, os transcritos do PHLDA1 foram também identificados como menos expressos em tumores primários de mama em relação ao tecido mamário normal (Nagai et al, 2003).…”

Section: Utilizando a Técnica De Ddrt-pcr (Diferencial Display Reverseunclassified

Efeitos do 17-estradiol e da lâmina na regulação da expressão dos genes DDEF2 e PHLDA1 em linhagens de células derivadas de adenocarcinomas de mama MCF-7 e MDA-MB-231

Marchiori¹

View full text Add to dashboard Cite

Differentially expressed genes and estrogen receptor status in breast cancer

Cited by 11 publications

References 0 publications

Gene expression profiles in breast tumors regarding the presence or absence of estrogen and progesterone receptors

Gene expression profiles in breast tumors regarding the presence or absence of estrogen and progesterone receptors

Transcriptional up-regulation of PHLDA1 by 17β-estradiol in MCF-7 breast cancer cells

Efeitos do 17-estradiol e da lâmina na regulação da expressão dos genes DDEF2 e PHLDA1 em linhagens de células derivadas de adenocarcinomas de mama MCF-7 e MDA-MB-231

Contact Info

Product

Resources

About