Refined histopathological predictors of BRCA1 and BRCA2 mutation status: A large-scale analysis of breast cancer characteristics from the BCAC, CIMBA, and ENIGMA consortia

Introduction: The distribution of histopathological features of invasive breast tumors in BRCA1 or BRCA2 germline mutation carriers differs from that of individuals with no known mutation. Histopathological features thus have utility for mutation prediction, including statistical modeling to assess pathogenicity of BRCA1 or BRCA2 variants of uncertain clinical significance. We analyzed large pathology datasets accrued by the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) and the Breast Cancer Association Consortium (BCAC) to reassess histopathological predictors of BRCA1 and BRCA2 mutation status, and provide robust likelihood ratio (LR) estimates for statistical modeling. Methods: Selection criteria for study/center inclusion were estrogen receptor (ER) status or grade data available for invasive breast cancer diagnosed younger than 70 years. The dataset included 4,477 BRCA1 mutation carriers, 2,565 BRCA2 mutation carriers, and 47,565 BCAC breast cancer cases. Country-stratified estimates of the

A case-only study to identify genetic modifiers of breast cancer risk for BRCA1/BRCA2 mutation carriers

Breast cancer (BC) risk for BRCA1 and BRCA2 mutation carriers varies by genetic and familial factors. About 50 common variants have been shown to modify BC risk for mutation carriers. All but three, were identified in general population studies. Other mutation carrier-specific susceptibility variants may exist but studies of mutation carriers have so far been underpowered. We conduct a novel case-only genome-wide association study comparing genotype frequencies between 60,212 general population BC cases and 13,007 cases with BRCA1 or BRCA2 mutations. We identify robust novel associations for 2 variants with BC for BRCA1 and 3 for BRCA2 mutation carriers, P < 10−8, at 5 loci, which are not associated with risk in the general population. They include rs60882887 at 11p11.2 where MADD, SP11 and EIF1, genes previously implicated in BC biology, are predicted as potential targets. These findings will contribute towards customising BC polygenic risk scores for BRCA1 and BRCA2 mutation carriers

The impact of cell source, culture methodology, culture location, and individual donors on gene expression profiles of bone marrow-derived and adipose-derived stromal cells

Item does not contain fulltextBone marrow (BM) stromal cells (MSCs), also known as mesenchymal stem cells, display a high degree of heterogeneity. To shed light on the causes of this heterogeneity, MSCs were collected from either human BM (n=5) or adipose tissue (AT) (n=5), and expanded using 2 different culture methods: one based on fetal calf serum, and one based on human platelet lysate. After initial expansion, MSCs were frozen, and the vials were transported to 3 different laboratories and grown for 1 passage using the same brand of culture plastic, medium, and supplements. Subsequently, the cells were harvested and assayed for their gene expression profile using the Affymetrix exon microarray platform. Based on gene expression profiles, the most discriminative feature was the anatomical harvesting site, followed by culture methodology. Remarkably, genes in the WNT pathway were expressed at higher levels in BM-derived MSCs than in AT-derived MSCs. Although differences were found between laboratories, cell culture location only slightly affects heterogeneity. Furthermore, individual donors contributed marginally to the observed differences in transcriptomes. Finally, BM-derived MSCs displayed the highest level of similarity, irrespective their culture conditions, when compared to AT-derived cells

Linnés ladugård : Ekonomibyggnaderna på Hammarby säteri, Danmarks socken, Uppland, under 1700-talets andra hälft : Rapport till Länsstyrelsen i Uppsala 20090119

Glucocorticoids are the cornerstone in the clinic for treatment of hematological malignancies, including multiple myeloma. Nevertheless, poor pharmacokinetic properties of glucocorticoids require high and frequent dosing with the off-target adverse effects defining the maximum dose. Recently, nanomedicine formulations of glucocorticoids have been developed that improve the pharmacokinetic profile, limit adverse effects and improve solid tumor accumulation. Multiple myeloma is a hematological malignancy characterized by uncontrolled growth of plasma cells. These tumors initiate increased angiogenesis and microvessel density in the bone marrow, which might be exploited using nanomedicines, such as liposomes. Nano-sized particles can accumulate as a result of the increased vascular leakiness at the bone marrow tumor lesions. Pre-clinical screening of novel anti-myeloma therapeutics in vivo requires a suitable animal model that represents key features of the disease. In this study, we show that fluorescently labeled long circulating liposomes were found in plasma up to 24 h after injection in an advanced human-mouse hybrid model of multiple myeloma. Besides the organs involved in clearance, liposomes were also found to accumulate in tumor bearing human-bone scaffolds. The therapeutic efficacy of liposomal dexamethasone phosphate was evaluated in this model showing strong tumor growth inhibition while free drug being ineffective at an equivalent dose (4 mg/kg) regimen. The liposomal formulation slightly reduced total body weight of myeloma-bearing mice during the course of treatment, which appeared reversible when treatment was stopped. Liposomal dexamethasone could be further developed as monotherapy or could fit in with existing therapy regimens to improve therapeutic outcomes for multiple myeloma

N-cadherin-mediated interaction with multiple myeloma cells inhibits osteoblast differentiation

Background Multiple myeloma is a hematologic malignancy characterized by a clonal expansion of malignant plasma cells in the bone marrow, which is accompanied by the development of osteolytic lesions and/or diffuse osteopenia. The intricate bi-directional interaction with the bone marrow microenvironment plays a critical role in sustaining the growth and survival of myeloma cells during tumor progression. Identification and functional analysis of the (adhesion) molecules involved in this interaction will provide important insights into the pathogenesis of multiple myeloma. Design and Methods Multiple myeloma cell lines and patients' samples were analyzed for expression of the adhesion molecule N-cadherin by immunoblotting, flow cytometry, immunofluorescence microscopy, immunohistochemistry and expression microarray. In addition, by means of blocking antibodies and inducible RNA interference we studied the functional consequence of N-cadherin expression for the myeloma cells, by analysis of adhesion, migration and growth, and for the bone marrow microenvironment, by analysis of osteogenic differentiation. Results The malignant plasma cells in approximately half of the multiple myeloma patients, belonging to specific genetic subgroups, aberrantly expressed the homophilic adhesion molecule N-cadherin. N-cadherin-mediated cell-substrate or homotypic cell-cell adhesion did not contribute to myeloma cell growth in vitro. However, N-cadherin directly mediated the bone marrow localization/retention of myeloma cells in vivo, and facilitated a close interaction between myeloma cells and N-cadherin-positive osteoblasts. Furthermore, this N-cadherin-mediated interaction contributed to the ability of myeloma cells to inhibit osteoblastogenesis. Conclusions Taken together, our data show that myeloma cells frequently display aberrant expression of N-cadherin and that N-cadherin mediates the interaction of myeloma cells with the bone marrow microenvironment, in particular the osteoblasts. This N-cadherin-mediated interaction inhibits osteoblast differentiation and may play an important role in the pathogenesis of myeloma bone diseas

The FANCM:p.Arg658* truncating variant is associated with risk of triple-negative breast cancer

Breast cancer is a common disease partially caused by genetic risk factors. Germline pathogenic variants in DNA repair genes BRCA1, BRCA2, PAM, ATM, and CHEK2 are associated with breast cancer risk. FANCM, which encodes for a DNA translocase, has been proposed as a breast cancer predisposition gene, with greater effects for the ER-negative and triple-negative breast cancer (TNBC) subtypes. We tested the three recurrent protein-truncating variants FANCM:p.Arg658*, p.Gln1701*, and pArg1931* for association with breast cancer risk in 67,112 cases, 53,766 controls, and 26,662 carriers of pathogenic variants of BRCA1 or BRCA2. These three variants were also studied functionally by measuring survival and chromosome fragility in FANCM(-/-) patient-derived immortalized fibroblasts treated with diepoxybutane or olaparib. We observed that FANCM:p.Arg658* was associated with increased risk of ER-negative disease and TNBC (OR = 2.44, P = 0.034 and OR = 3.79; P = 0.009, respectively). In a country-restricted analysis, we confirmed the associations detected for FANCM:p.Arg658* and found that also FANCM:p.Arg1931* was associated with ER-negative breast cancer risk (OR = 1.96; P = 0.006). The functional results indicated that all three variants were deleterious affecting cell survival and chromosome stability with FANCM:p.Arg658* causing more severe phenotypes. In conclusion, we confirmed that the two rare FANCM deleterious variants p.Arg658* and p.Arg1931* are risk factors for ER-negative and TNBC subtypes. Overall our data suggest that the effect of truncating variants on breast cancer risk may depend on their position in the gene. Cell sensitivity to olaparib exposure, identifies a possible therapeutic option to treat FANCM-associated tumors.Surgical oncolog

PHIP:a novel candidate breast cancer susceptibility locus on 6q14.1

Abstract Most non-BRCA1/2 breast cancer families have no identified genetic cause. We used linkage and haplotype analyses in familial and sporadic breast cancer cases to identify a susceptibility locus on chromosome 6q. Two independent genome-wide linkage analysis studies suggested a 3 Mb locus on chromosome 6q and two unrelated Swedish families with a LOD &gt;2 together seemed to share a haplotype in 6q14.1. We hypothesized that this region harbored a rare high-risk founder allele contributing to breast cancer in these two families. Sequencing of DNA and RNA from the two families did not detect any pathogenic mutations. Finally, 29 SNPs in the region were analyzed in 44,214 cases and 43,532 controls from BCAC, and the original haplotypes in the two families were suggested as low-risk alleles for European and Swedish women specifically. There was also some support for one additional independent moderate-risk allele in Swedish familial samples. The results were consistent with our previous findings in familial breast cancer and supported a breast cancer susceptibility locus at 6q14.1 around the PHIP gene

Genetic variation in mitotic regulatory pathway genes is associated with breast tumor grade.

Mitotic index is an important component of histologic grade and has an etiologic role in breast tumorigenesis. Several small candidate gene studies have reported associations between variation in mitotic genes and breast cancer risk. We measured associations between 2156 single nucleotide polymorphisms (SNPs) from 194 mitotic genes and breast cancer risk, overall and by histologic grade, in the Breast Cancer Association Consortium (BCAC) iCOGS study (n = 39 067 cases; n = 42 106 controls). SNPs in TACC2 [rs17550038: odds ratio (OR) = 1.24, 95% confidence interval (CI) 1.16-1.33, P = 4.2 × 10(-10)) and EIF3H (rs799890: OR = 1.07, 95% CI 1.04-1.11, P = 8.7 × 10(-6)) were significantly associated with risk of low-grade breast cancer. The TACC2 signal was retained (rs17550038: OR = 1.15, 95% CI 1.07-1.23, P = 7.9 × 10(-5)) after adjustment for breast cancer risk SNPs in the nearby FGFR2 gene, suggesting that TACC2 is a novel, independent genome-wide significant genetic risk locus for low-grade breast cancer. While no SNPs were individually associated with high-grade disease, a pathway-level gene set analysis showed that variation across the 194 mitotic genes was associated with high-grade breast cancer risk (P = 2.1 × 10(-3)). These observations will provide insight into the contribution of mitotic defects to histological grade and the etiology of breast cancer