The Heregulin/Human Epidermal Growth Factor Receptor as a New Growth Factor System in Melanoma with Multiple Ways of Deregulation

In a screening for new growth factors released by melanoma cells, we found that the p185-phosphorylating capacity of a medium conditioned by a melanoma cell line was due to the secretion of heregulin, a ligand for the human epidermal growth factor receptor (HER) family of receptor tyrosine kinases. Expression of heregulin, including a new isoform, and secretion of functionally active protein was found in several cell lines. Receptor activation by heregulin, either autocrine or paracrine, resulted in a potent growth stimulation of both melanocytes and melanoma cells. Heregulin receptor HER3 and coreceptor HER2 were the main receptors expressed by these cells. Nevertheless, none of the cell lines in our panel overexpressed HER2 or HER3. In contrast, loss of HER3 was found in two cell lines, whereas one cell line showed loss of functional HER2, both types of deregulations resulting in unresponsiveness to heregulin. This implies the heregulin/HER system as a possible important physiologic growth regulatory system in melanocytes in which multiple deregulations may occur during progression toward melanoma, all resulting in, or indicating, growth factor independence

Adipose tissue in breast cancer : not an idle bystander but an active participant in breast cancer progression

Background: Adipose tissue is a dynamic organ that secretes a plethora of molecules called adipokines. In breast cancer we find a unique situation were genetically changed cells (the cancer cells) are in close contact with adipocytes. Moreover, obesity is a known negative prognostic marker for postmenopausal breast cancer patients. We hypothesize that adipocyte-derived factors influence breast cancer progression. Materials and methods: Adipose tissue was collected from breast cancer patients undergoing a mastectomy. After macroscopic removal of blood vessels and connective tissue, the adipose tissue was carefully cut into 2-3mm3 pieces and were incubated in specific adipose-tissue culture medium. After 24h, the medium was collected and the quality was checked by determining the concentration of total proteins, leptin, adiponectin, TNFalpha and triglycerides. This conditioned medium of adipose tissue (CM AT) was used for in vitro experimentation with MCF-7 breast cancer cells. Results: Effect of AT on morphology and aggregation: when MCF-7 cells are grown in a culture flask, they tend to form round compact islands. Under influence of CM AT, the islands form sharp edges, the cells in an island can be counted individually and they show scattering. Importantly, despite the major changes in cellular morphology, CM AT removal rescued the compact island formation of MCF-7 cells. In the slow aggregation assay, cells treated with CM AT (and a subtherapeutic concentration of a neutralizing E-cadherin antibody) lost the ability to form compact aggregates. Furthermore, MCF-7 spheroids placed inside adipose tissue showed massive reorganization into an irregularly shaped mass. Effect of AT on proliferation: starting from an equal number of cells and counting them every 2 days, it became clear that MCF-7 cells with CM AT had a higher rate of proliferation than MCF-7 cells in control medium. This stimulation of proliferation was confirmed by cell cycle analysis which revealed a doubling of cells in the G2/M phase, and western blot which showed an upregulation of cyclin A and cyclin E, both positive regulators of the cell cycle. Effect of AT on invasion: a 24h collagen type I invasion assay revealed invasive characteristics of MCF-7 cells treated with CM AT while MCF-7 cells in control conditions are round and non-invasive. In contrast, a transwell collagen test over 14 days was not able to show MCF-7 cells invading the collagen gel under influence of CM AT. However, the growth pattern of MCF-7 cells on the collagen gel was clearly disorganised when compared with the control situation. Conclusion: These findings suggest that adipose tissue-derived factors exert a dramatic selective force on patterning, invasion and growth of MCF-7 breast cancer cells. Unraveling the mechanism behind these observations may provide vital information regarding the link between obesity and poor prognosis in postmenopausal breast cancer

Secretome analysis of breast cancer-associated adipose tissue to identify paracrine regulators of breast cancer growth

Adipose tissue secretes a plethora of adipokines as evidenced by characterization of subcutaneous and visceral adipose tissue secretomes. However, adipose tissue composition and secretion pattern is depot and disease dependent, influencing the adipose tissue secretome. We investigated the secretome of cancer-associated adipose tissue (CAAT) explants from breast cancer patients and explored its role in breast cancer proliferation. CAAT proteins were identified by LC-MS/MS and human protein antibody arrays and stimulated proliferation of three breast cancer cell lines. Kinomics and transcriptomics of MCF-7 breast cancer cells treated with the secretome of CAAT revealed activation of Akt-, ERK- and JNK-pathways and differential expression of activator protein 1 (AP-1) and cAMP responsive element-binding protein (CREB) target genes. The cyclin-dependent kinase (CDK) 4/6-inhibitor palbociclib significantly abrogated CAAT-enhanced breast cancer cell proliferation. Our work characterizes the specific breast CAAT protein secretome and reveals its pro-proliferative potency in breast cancer

Differential regulation of extracellular matrix protein expression in carcinoma-associated fibroblasts by TGF-β1 regulates cancer cell spreading but not adhesion

Cancer progression is characterized by a complex reciprocity between neoplastic epithelium and adjacent stromal cells. In ductal carcinoma in situ (DCIS) of the breast, both reduced stromal decorin expression and myxoid stroma are correlated with increased recurrence risk. In this study, we aimed to investigate paracrine regulation of expression of decorin and related extracellular matrix (ECM) proteins in cancerassociated fibroblasts (CAFs). Transforming growth factor-β1 (TGF-β1) was identified as a competent ECM modulator, as it reduced decorin and strongly enhanced versican, biglycan and type I collagen expression. Similar but less pronounced effects were observed when fibroblasts were treated with basic fibroblast growth factor (bFGF). Despite this concerted ECM modulation, TGF-β1 and bFGF differentially regulated alpha-smooth muscle actin (α-SMA) expression, which is often proposed as a CAFmarker. Cancer cell-derived secretomes induced versican and biglycan expression in fibroblasts. Immunohistochemistry on twenty DCIS specimens showed a trend toward periductal versican overexpression in DCIS with myxoid stroma. Cancer cell adhesion was inhibited by decorin, but not by CAF-derived matrices. Cancer cells presented significantly enhanced spreading when seeded on matrices derived from TGF-β1-treated CAF. Altogether these data indicate that preinvasive cancerous lesions might modulate the composition of surrounding stroma through TGF-β1 release to obtain an invasion-permissive microenvironment

Clinical and Hemodynamic Effects of Percutaneous Edge-to-Edge Mitral Valve Repair in Atrial Versus Ventricular Functional Mitral Regurgitation.

The present study aims to assess the clinical and hemodynamic impact of percutaneous edge-to-edge mitral valve repair with MitraClip in patients with atrial functional mitral regurgitation (A-FMR) compared with ventricular functional mitral regurgitation (V-FMR). Mitral regurgitation (MR) grade, functional status (New York Heart Association class), and major adverse cardiac events (MACE; all-cause mortality or hospitalization for heart failure) were evaluated in 52 patients with A-FMR and in 307 patients with V-FMR. In 56 patients, hemodynamic assessment during exercise echocardiography was performed before and 6 months after intervention. MR reduction after MitraClip implantation was noninferior in A-FMR compared with V-FMR (MR grade ≤2 at 6 months in 94% vs 82%, respectively, p <0.001 for noninferiority) and was associated with improvement of functional status (New York Heart Association class ≤2 at 6 months in 90% vs 80%, respectively, p = 0.2). Hemodynamic assessment revealed that cardiac output at 6 months was higher in A-FMR at rest (5.1 ± 1.5 L/min vs 3.8 ± 1.5 L/min, p = 0.002) and during peak exercise (7.9 ± 2.4 L/min vs 6.1 ± 2.1 L/min, p = 0.02). In addition, the reduction in systolic pulmonary artery pressure at rest was more pronounced in A-FMR: Δ SPAP -13.1 ± 15.1 mm Hg versus -2.2 ± 13.3 mm Hg (p = 0.03). MACE rate at follow-up was significantly lower in A-FMR versus V-FMR, with an adjusted odds ratio of 0.46 (95% confidence interval 0.24 to 0.88), which was caused by a reduction in hospitalization for heart failure. In conclusion, percutaneous edge-to-edge mitral valve repair with MitraClip is at least as effective in A-FMR as in V-FMR in reducing MR. However, the hemodynamic improvement and reduction of MACE were significantly better in A-FMR

Association of Forced Vital Capacity with the Developmental Gene <i>NCOR2</i>

Background Forced Vital Capacity (FVC) is an important predictor of all-cause mortality in the absence of chronic respiratory conditions. Epidemiological evidence highlights the role of early life factors on adult FVC, pointing to environmental exposures and genes affecting lung development as risk factors for low FVC later in life. Although highly heritable, a small number of genes have been found associated with FVC, and we aimed at identifying further genetic variants by focusing on lung development genes. Methods Per-allele effects of 24,728 SNPs in 403 genes involved in lung development were tested in 7,749 adults from three studies (NFBC1966, ECRHS, EGEA). The most significant SNP for the top 25 genes was followed-up in 46,103 adults (CHARGE and SpiroMeta consortia) and 5,062 chi

Genome-wide association analysis identifies six new loci associated with forced vital capacity

Forced vital capacity (FVC), a spirometric measure of pulmonary function, reflects lung volume and is used to diagnose and monitor lung diseases. We performed genome-wide association study meta-analysis of FVC in 52,253 individuals from 26 studies and followed up the top associations in 32,917 additional individuals of European ancestry. We found six new regions associated at genome-wide significance (P < 5 × 10−8) with FVC in or near EFEMP1, BMP6, MIR129-2–HSD17B12, PRDM11, WWOX and KCNJ2. Two loci previously associated with spirometric measures (GSTCD and PTCH1) were related to FVC. Newly implicated regions were followed up in samples from African-American, Korean, Chinese and Hispanic individuals. We detected transcripts for all six newly implicated genes in human lung tissue. The new loci may inform mechanisms involved in lung development and the pathogenesis of restrictive lung disease