Messenger RNA expression of leptin and leptin receptors and their prognostic value in 322 human primary breast cancers.

PURPOSE: Leptin and obesity are clearly related, and obesity is associated with an increased risk of breast cancer. We therefore measured the expression of leptin and its two main receptor isoforms, OBR-L and OBR-S, in 322 breast cancers. We analyzed their relations with the classical prognostic factors and with survival to establish their links with breast cancer. EXPERIMENTAL DESIGN: The expression of leptin and its receptors was quantified by real-time reverse transcription-PCR, using TaqMan fluorogenic probes and an ABI PRISM 7700 sequence detector system (Applied Biosystems, Courtaboeuf, France). TATA box binding protein was used to normalize expression. The human breast cancer cell, SK-BR-3, expressing the three targets, was chosen as the calibrator sample (i.e., target expression = 1). RESULTS: All the tumors expressed both receptors, and 318 of 322 expressed leptin. These three variables correlated positively with each other and with estradiol and progesterone receptors, whereas they correlated negatively with histoprognostic grading and tumor diameter. OBR-L/OBR-S expression was inversely correlated with progesterone receptors. Patients with elevated OBR-S expression had longer relapse-free survival (P = 0.008), whereas high OBR-L/OBR-S was associated with a shorter relapse-free survival (P = 0.05). In Cox multivariate analyses, OBR-S maintained its prognostic value (P = 0.02; relative risk, 0.51). CONCLUSIONS: This study shows that (a) almost all of the breast cancers coexpress leptin and its two main isoforms of receptors, suggesting that the human epithelial breast cancer cells respond to leptin acting via an autocrine pathway; (b) high expression levels of leptin and leptin receptors are biological markers of a more differentiated phenotype; and that (c) OBR-S is an independent prognostic factor.

Prognostic value of ERM gene expression in human primary breast cancers.

We measured the expression of ERM gene, a nuclear transcription factor belonging to the ets family, in a series of 364 unselected primary breast cancers from patients who underwent locoregional surgery in the Centre Oscar Lambret between May 1989 and December 1991. The expression of ERM was quantified with a real-time one-step reverse transcription-PCR assay based on the 5'-nuclease activity of the TaqDNA polymerase and with an Abi Prism 7700 Sequence Detector System (Applied Biosystems, Courtaboeuf, France). ERM was positively correlated (Spearman test) to epidermal growth factor receptor (EGFR; P < 0.001, r = 0.296) and to histoprognostic grading (P = 0.044, r = 0.112), whereas it was negatively correlated to estradiol receptors (P = 0.019, r = -0.124), HER3 (c-erbB-3; P = 0.01, r = -0.135), and HER4 (c-erbB-4; P = 0.003, r = -0.154). Using the chi2 test, a positive relationship was found between the expression of ERM and EGFR (chi2 = 7.795, P = 0.007). In overall survival studies, Cox univariate analyses demonstrated a prognostic value of ERM (P = 0.006; risk ratio, 2.95) besides the classical prognostic factors histoprognostic grading, node involvement, tumor size, estradiol receptors, progesterone receptors, EGFR, HER3, and HER4. In multivariate analyses, ERM preserved its prognostic value (P = 0.004; risk ratio, 3.779) together with histoprognostic grading, tumor size, estradiol receptors, and progesterone receptors. In relapse-free survival studies, univariate analyses demonstrated that histoprognostic grading, node involvement, tumor size, and HER4 were prognostic factors. These parameters, except histoprognostic grading, retained their prognostic value in multivariate analyses. This study demonstrates for the first time that ERM gene expression is an independent adverse prognostic factor for overall survival in breast cancer patients.

Serum Proteome Analysis for Profiling Predictive Protein Markers Associated with the Severity of Skin Lesions Induced by Ionizing Radiation.

The finding of new diagnostic and prognostic markers of local radiation injury, and particularly of the cutaneous radiation syndrome, is crucial for its medical management, in the case of both accidental exposure and radiotherapy side effects. Especially, a fast high-throughput method is still needed for triage of people accidentally exposed to ionizing radiation. In this study, we investigated the impact of localized irradiation of the skin on the early alteration of the serum proteome of mice in an effort to discover markers associated with the exposure and severity of impending damage. Using two different large-scale quantitative proteomic approaches, 2D-DIGE-MS and SELDI-TOF-MS, we performed global analyses of serum proteins collected in the clinical latency phase (days 3 and 7) from non-irradiated and locally irradiated mice exposed to high doses of 20, 40 and 80 Gy which will develop respectively erythema, moist desquamation and necrosis. Unsupervised and supervised multivariate statistical analyses (principal component analysis, partial-least square discriminant analysis and Random Forest analysis) using 2D-DIGE quantitative protein data allowed us to discriminate early between non-irradiated and irradiated animals, and between uninjured/slightly injured animals and animals that will develop severe lesions. On the other hand, despite a high number of animal replicates, PLS-DA and Random Forest analyses of SELDI-TOF-MS data failed to reveal sets of MS peaks able to discriminate between the different groups of animals. Our results show that, unlike SELDI-TOF-MS, the 2D-DIGE approach remains a powerful and promising method for the discovery of sets of proteins that could be used for the development of clinical tests for triage and the prognosis of the severity of radiation-induced skin lesions. We propose a list of 15 proteins which constitutes a set of candidate proteins for triage and prognosis of skin lesion outcomes.

Relationships between progesterone receptor isoforms and the HER/ErbB receptors and ligands network in 299 primary breast cancers.

BACKGROUND: The effects of progesterone are mediated by 2 progesterone receptors (PR), PR-A and PR-B. Recently, several lines of evidence have suggested that reduced PR expression may result from hyperactivity in the signaling cascade generated by the HER/ErbB family. The aim of this study was to analyze the relationships between PR isoforms and the network of the HER/ErbB receptors and ligands in breast cancer. PATIENTS AND METHODS: 299 breast cancer samples from patients operated in our institute for locoregional disease between May 1989 and December 1991 were included. The mRNA expression of total PR-A+B isoforms and PR-B isoform were quantified by real time quantitative RT-PCR using TaqMan® probes. RESULTS: mRNA levels of the PR isoforms positively correlated with protein levels of estradiol receptors (ER) and PR. The PR isoforms mRNA levels were inversely correlated with clinicopathological markers of tumor aggressiveness, such as SBR grading and lymph node involvement. The PR isoforms positively correlated with the mRNA levels of HER/ErbB receptors and ligands associated with a more differentiated phenotype (HER3, HER4, EGF, AREG, NRG3 and NRG4) while they correlated negatively with those associated with aggressiveness (EGFR, TGFa, HB-EGF, EREG, and NRG2). CONCLUSION: Our results demonstrate the existence of strong correlations between mRNA levels of the PR isoforms, protein levels of hormone receptors, HER/ErbB receptors and ligands network, and thus suggest that crosstalks between PR and the HER family are a hallmark of breast cancer growth.

Expression and prognostic value of lactoferrin mRNA isoforms in human breast cancer.

We investigated the expression levels of human lactoferrin (Lf), a steroid hormone-inducible gene product the expression of which is often altered during oncogenesis, and of Delta-lactoferrin (DeltaLf), its alternative isoform, which has been shown to be absent from tumor cell lines in commonly used human breast epithelial cell lines, using semiquantitative RT-PCR. Both mRNAs were detected but with levels of expression lower than those found in normal breast epithelial cells. This downregulation was much more visible for DeltaLf since its expression was either significantly diminished (BT-20, MCF-7 cell lines) or practically absent (MDA-MB-231, T-47D, HBL 100 cell lines). In order to determine whether Lf gene products are useful prognosic tools, we further analyzed their expression levels in 99 primary breast cancer biopsies. DeltaLf transcripts were found in all of the samples, whereas Lf transcripts were found in 88% of them. Lf and DeltaLf expression levels were positively correlated (p = 0.003). Lf expression was related to tumor type with a higher recovery in lobular-type tumors (p = 0.04). DeltaLf expression was related to the histoprognostic grading (p = 0.02). In univariate analyses, DeltaLf and Lf expressions were prognosis parameters, high concentrations being associated with a longer overall survival.

Multiplex reverse transcription polymerase chain reaction assessment of sialyltransferase expression in peripheral blood mononuclear cells in systemic sclerosis.

OBJECTIVE: To assess sialyltransferase expression in peripheral blood mononuclear cells (PBMC) of patients with systemic sclerosis (SSc) and to correlate this expression with the clinical features of the disease. METHODS: Using a multiplex reverse transcription polymerase chain reaction (RT-PCR) method, we simultaneously measured the expression of 5 sialyltransferases (ST3Gal IV, ST3Gal III, ST3Gal I, ST3Gal II, and ST6Gal I) and of one reference housekeeping gene, Tata box binding protein (TBP), in PBMC of 28 patients with SSc and 18 healthy controls. Expression of each sialyltransferase was defined by the ratio sialyltransferase amplification product intensity/TBP amplification product intensity, and was evaluated according to the skin sclerosis extension and the presence of lung fibrosis and/or of pulmonary hypertension. RESULTS: ST3Gal I and ST6Gal I expressions were lower in patients with SSc than in healthy controls (median 0.48 vs 1.30, p < 0.0001, and 0.71 vs 1.96, p < 0.01, respectively). No difference was observed for ST3Gal III and ST3Gal IV expression. ST3Gal IV/ST6Gal I ratio was higher in SSc patients than in controls (0.37 vs 0.28, p = 0.03). ST3Gal II was either weakly or more often not expressed in both groups. Ten patients had isolated pulmonary hypertension. They had higher ST3Gal IV expression than patients without pulmonary hypertension (0.73 vs 0.29, p = 0.04) and a higher ST3Gal IV/ST6Gal I ratio than patients without pulmonary hypertension (1.03 vs 0.27, p = 0.03) and controls (1.03 vs 0.28, p = 0.02). No difference was found in the sialyltransferase expression and soluble E-selectin concentration according to the cutaneous sclerosis extension or the presence of lung fibrosis. CONCLUSION: Sialyltransferase expression is modified in PBMC of patients with SSc compared to healthy subjects. Low ST6Gal I expression associated with normal ST3Gal IV expression, resulting in a higher ST3Gal IV/ST6Gal I ratio, suggests an enhanced expression of Sialyl-LewisX at the surface of PBMC in SSc, and therefore an active interaction between activated endothelial cells and PBMC through the binding between E-selectin and Sialyl-LewisX. This suggested that higher expression of Sialyl-LewisX concerned patients with isolated pulmonary hypertension more specifically. Binding between PBMC surface Sialyl-LewisX and activated endothelial cell E-selectin might therefore play a role in the pathogenesis of SSc-related isolated pulmonary hypertension.

Cross-talk between mesenchyme and epithelium increases H19 gene expression during scattering and morphogenesis of epithelial cells.

The H19 gene is an imprinted gene expressed from the maternal allele. It is known to function as an RNA molecule. We previously reported that in breast adenocarcinoma, H19 is often overexpressed in stromal cells and preferentially located at the epithelium/stroma boundary, suggesting that epithelial/mesenchymal interactions can control H19 RNA expression. In some cases of breast adenocarcinoma with poor prognosis, H19 is overexpressed in epithelial cells. Therefore we examined whether mesenchymal factors can induce H19 expression in epithelial cells. Using quantitative RT-PCR and in situ hybridization, we found that when mammary epithelial cells were cultured in collagen gels, H19 expression was strongly up-regulated compared to when cells were cultured on plastic. Collagen gels allow three-dimensional growth of epithelial cells and morphogenetic responses to soluble factors. A conditioned medium from MRC-5 fibroblasts caused branching morphogenesis of HBL-100 cells and invasive growth of MDA-MB-231 cells, whereas MCF-7 cells were unresponsive. Induction of H19 expression correlated with morphological changes in HBL-100 and in MDA-MB-231 cells, whereas H19 expression was not induced in MCF-7 cells. Using a blocking antibody, HGF/SF was identified as the fibroblast-derived growth factor capable of inducing H19 expression and cell morphogenesis. We further demonstrated that H19 promoter activity was stimulated by various growth factors using transient transfection in MDCK epithelial cells. HGF/SF was more efficient than EGF or FGF-2 in transactivating the H19 promoter, whereas IGF-2, TGFbeta-1, and TNF-alpha were ineffective. This activation by HGF/SF was prevented by pharmacological inhibition of MAP kinase or of phospholipase C. We conclude that H19 is a target gene for HGF/SF, a known regulator of epithelial/mesenchymal interactions, and suggest that the up-regulation of H19 may be implicated in morphogenesis and/or migration of epithelial cells.