Search results for "BREAST"

Midregion PTHrP and Human Breast Cancer Cells

2010

PTHrP is a polyhormone undergoing proteolytic processing into smaller bioactive forms, comprising an N-terminal peptide, which is the mediator of the “classical” PTH-like effect, as well as midregion and C-terminal peptides. The midregion PTHrP domain (38-94)-amide was found to restrain growth and invasionin vitroof some breast cancer cell lines, causing striking toxicity and accelerating death; the most responsive being MDA-MB231, whose tumorigenesis was also attenuatedin vivo. In addition, midregion PTHrP appears to be imported in the nucleoplasm of cultured MDA-MB231 cells andin vitro, it can bind chromatin of metaphase spread preparations and also an isolated 20-mer oligonucleotide, the…

A multivariate statistical test for differential expression analysis

2022

AbstractStatistical tests of differential expression usually suffer from two problems. Firstly, their statistical power is often limited when applied to small and skewed data sets. Secondly, gene expression data are usually discretized by applying arbitrary criteria to limit the number of false positives. In this work, a new statistical test obtained from a convolution of multivariate hypergeometric distributions, the Hy-test, is proposed to address these issues. Hy-test has been carried out on transcriptomic data from breast and kidney cancer tissues, and it has been compared with other differential expression analysis methods. Hy-test allows implicit discretization of the expression profi…

HIF-1α induces MXI1 by alternate promoter usage in human neuroblastoma cells

2009

Adaptation to low oxygen conditions is essential for maintaining homeostasis and viability in oxygen-consuming multi-cellular tissues, including solid tumors. Central in these processes are the hypoxia-inducible transcription factors, HIF-1 and HIF-2, controlling genes involved in e.g. glucose metabolism and neovascularization. Tumor hypoxia and HIF expression have also been associated with a dedifferentiated phenotype and increased aggressiveness. In this report we show that the MAX interactor-1 (MXI1) gene is directly regulated by HIF proteins in neuroblastoma and breast cancer cells. HIF-binding and transactivation were detected within MXI1 gene regulatory sequences in the vicinity of th…

Selective Activation of Trophoblast-specific PLAC1 in Breast Cancer by CCAAT/Enhancer-binding Protein β (C/EBPβ) Isoform 2

2009

The trophoblast-specific gene PLAC1 (placenta-specific 1) is ectopically expressed in a wide range of human malignancies, most frequently in breast cancer, and is essentially involved in cancer cell proliferation, migration, and invasion. Here we show that basal activity of the PLAC1 promoter is selectively controlled by ubiquitous transcription factor SP1 and isoform 2 of CCAAT/enhancer-binding protein beta that we found to be selectively expressed in placental tissue and cancer cells. Binding of both factors to their respective elements within the PLAC1 promoter was essential to attain full promoter activity. Estrogen receptor alpha (ERalpha) signaling further augmented transcription and …

2021

Bone is a frequent site of metastases, being typically associated with a short-term prognosis in affected patients. Photodynamic therapy (PDT) emerges as a promising alternative treatment for controlling malignant disease that can directly target interstitial metastatic lesions. The aim of this study was to assess the effect induced by PDT treatment on both primary (giant cell bone tumor) and human bone metastatic cancer cell lines (derived from a primary invasive ductal breast carcinoma and renal carcinoma). After 24 h post light delivery (blue light-wavelength 436 nm) with 5-aminolevulinic acid, the effect on cellular migration, viability, apoptosis, and senescence were assessed. Our resu…

Novel circulating microRNA signature as a potential non-invasive multi-marker test in ER-positive early-stage breast cancer:A case control study

2014

Introduction There are currently no highly sensitive and specific minimally invasive biomarkers for detection of early‐stage breast cancer. MicroRNAs (miRNAs) are present in the circulation and may be unique biomarkers for early diagnosis of human cancers. The aim of this study was to investigate the differential expression of miRNAs in the serum of breast cancer patients and healthy controls. Methods Global miRNA analysis was performed on serum from 48 patients with ER‐positive early‐stage breast cancer obtained at diagnosis (24 lymph node‐positive and 24 lymph node‐negative) and 24 age‐matched healthy controls using LNA‐based quantitative real‐time PCR (qRT‐PCR). A signature of miRNAs was…

Inhibition of the HER2 pathway by n-3 polyunsaturated fatty acids prevents breast cancer in fat-1 transgenic mice

2013

Overexpression of the tyrosine kinase receptor, ErbB2/HER2/Neu, occurs in 25–30% of invasive breast cancer (BC) with poor patient prognosis. Due to confounding factors, inconsistencies still remain regarding the protective effects of n-3 polyunsaturated fatty acids (PUFAs) on BC. We therefore evaluated whether fat-1 transgenic mice, endogenously synthesizing n-3 PUFAs from n-6 PUFAs, were protected against BC development, and we then aimed to study in vivo a mechanism potentially involved in such protection. E0771 BC cells were implanted into fat-1 and wild-type (WT) mice. After tumorigenesis examination, we analyzed the expression of proteins involved in the HER2 signaling pathway and lipi…

n-3 polyunsaturated fatty acids and HER2-positive breast cancer: interest of the fat-1 transgenic mouse model over conventional dietary supplementati…

2013

Overexpression of the tyrosine kinase receptor ErbB2/HER2/Neu, occurs in 25%-30% of invasive breast cancer (BC) with poor patient prognosis. Even if numerous studies have shown prevention of breast cancer by n-3 fatty acid intake, the experimental conditions under which n-3 fatty acids exert their protective effect have been variable from study to study, preventing unifying conclusions. Due to confounding factors, inconsistencies still remain regarding protective effects of n-3 polyunsaturated fatty acids (PUFA) on BC. When animals are fed with dietary supplementation in n-3 fatty acids (the traditional approach to modify tissue content and decrease the n-6/n-3 ratio) complex dietary intera…

The Genetics of Breast Cancer

2009

Breast cancer (BC) is a complex and heterogeneous disease caused by interaction of both genetic and nongenetic risk factors. The biological diversity of sporadic BCs consists in the development of several BC subtypes, which are systematically different from one another and which present specific genetic and phenotypic features. Recently, with the advent of cDNA microarrays it has been possible to associate a distinctive “molecular portrait” to a single BC subtype and, consequently, improve BC taxonomy. From a clinical point of view, the gene expression profiles could supply the classic pathological experiment with the aim to select patients with a better prognosis and that could have a bene…

The CpG island methylator phenotype in breast cancer is associated with the lobular subtype

2014

Background: Aberrations in DNA methylation patterns are well-described in human malignancies. However, the existence of the ‘CpG island methylator phenotype’ (CIMP) in human breast cancer is still controversial. Materials & methods: Illumina's HumanMethylation 450K BeadChip was used to analyze genome-wide DNA methylation patterns. Chromosomal abnormalities were determined by array-based CGH. Results: Invasive lobular breast carcinomas exhibit the highest number of differentially methylated CpG sites and a strong inverse correlation of aberrant DNA hypermethylation and copy number alterations. Nine differentially methylated regions within seven genes discriminating the investigated subg…