57 research outputs found
ABCC10 (ATP-binding cassette, sub-family C (CFTR/MRP), member 10)
Review on ABCC10, with data on DNA/RNA, on the protein encoded and where the gene is implicated
Wikipedia Information Flow Analysis Reveals the Scale-Free Architecture of the Semantic Space
In this paper we extract the topology of the semantic space in its encyclopedic acception, measuring the semantic flow between the different entries of the largest modern encyclopedia, Wikipedia, and thus creating a directed complex network of semantic flows. Notably at the percolation threshold the semantic space is characterised by scale-free behaviour at different levels of complexity and this relates the semantic space to a wide range of biological, social and linguistics phenomena. In particular we find that the cluster size distribution, representing the size of different semantic areas, is scale-free. Moreover the topology of the resulting semantic space is scale-free in the connectivity distribution and displays small-world properties. However its statistical properties do not allow a classical interpretation via a generative model based on a simple multiplicative process. After giving a detailed description and interpretation of the topological properties of the semantic space, we introduce a stochastic model of content-based network, based on a copy and mutation algorithm and on the Heaps' law, that is able to capture the main statistical properties of the analysed semantic space, including the Zipf's law for the word frequency distribution
Imatinib and Nilotinib Reverse Multidrug Resistance in Cancer Cells by Inhibiting the Efflux Activity of the MRP7 (ABCC10)
One of the major mechanisms that could produce resistance to antineoplastic drugs in cancer cells is the ATP binding cassette (ABC) transporters. The ABC transporters can significantly decrease the intracellular concentration of antineoplastic drugs by increasing their efflux, thereby lowering the cytotoxic activity of antineoplastic drugs. One of these transporters, the multiple resistant protein 7 (MRP7, ABCC10), has recently been shown to produce resistance to antineoplastic drugs by increasing the efflux of paclitaxel. In this study, we examined the effects of BCR-Abl tyrosine kinase inhibitors imatinib, nilotinib and dasatinib on the activity and expression of MRP7 in HEK293 cells transfected with MRP7, designated HEK-MRP7-2.We report for the first time that imatinib and nilotinib reversed MRP7-mediated multidrug resistance. Our MTT assay results indicated that MRP7 expression in HEK-MRP7-2 cells was not significantly altered by incubation with 5 microM of imatinib or nilotinib for up to 72 hours. In addition, imatinib and nilotinib (1-5 microM) produced a significant concentration-dependent reversal of MRP7-mediated multidrug resistance by enhancing the sensitivity of HEK-MRP7-2 cells to paclitaxel and vincristine. Imatinib and nilotinib, at 5 microM, significantly increased the accumulation of [(3)H]-paclitaxel in HEK-MRP7-2 cells. The incubation of the HEK-MRP7-2 cells with imatinib or nilotinib (5 microM) also significantly inhibited the efflux of paclitaxel.Imatinib and nilotinib reverse MRP7-mediated paclitaxel resistance, most likely due to their inhibition of the efflux of paclitaxel via MRP7. These findings suggest that imatinib or nilotinib, in combination with other antineoplastic drugs, may be useful in the treatment of certain resistant cancers
ATP-binding cassette (ABC) transporters in normal and pathological lung
ATP-binding cassette (ABC) transporters are a family of transmembrane proteins that can transport a wide variety of substrates across biological membranes in an energy-dependent manner. Many ABC transporters such as P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1) and breast cancer resistance protein (BCRP) are highly expressed in bronchial epithelium. This review aims to give new insights in the possible functions of ABC molecules in the lung in view of their expression in different cell types. Furthermore, their role in protection against noxious compounds, e.g. air pollutants and cigarette smoke components, will be discussed as well as the (mal)function in normal and pathological lung. Several pulmonary drugs are substrates for ABC transporters and therefore, the delivery of these drugs to the site of action may be highly dependent on the presence and activity of many ABC transporters in several cell types. Three ABC transporters are known to play an important role in lung functioning. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene can cause cystic fibrosis, and mutations in ABCA1 and ABCA3 are responsible for respectively Tangier disease and fatal surfactant deficiency. The role of altered function of ABC transporters in highly prevalent pulmonary diseases such as asthma or chronic obstructive pulmonary disease (COPD) have hardly been investigated so far. We especially focused on polymorphisms, knock-out mice models and in vitro results of pulmonary research. Insight in the function of ABC transporters in the lung may open new ways to facilitate treatment of lung diseases
PALB2, CHEK2 and ATM rare variants and cancer risk : data from COGS
AbstractBackground: The rarity of mutations in PALB2, CHEK2 and ATM make it difficult to estimate precisely associated cancer risks. Population-based family studies have provided evidence that at least some of these mutations are associated with breast cancer risk as high as those associated with rare BRCA2 mutations. We aimed to estimate the relative risks associated with specific rare variants in PALB2, CHEK2 and ATM via a multicentre case-control study.Methods: We genotyped 10 rare mutations using the custom iCOGS array: PALB2 c.1592delT, c.2816T>G and c.3113G>A, CHEK2 c.349A>G, c.538C>T, c.715G>A, c.1036C>T, c.1312G>T, and c.1343T>G and ATM c.7271T>G. We assessed associations with breast cancer risk (42 671 cases and 42 164 controls), as well as prostate (22 301 cases and 22 320 controls) and ovarian (14 542 cases and 23 491 controls) cancer risk, for each variant.Results: For European women, strong evidence of association with breast cancer risk was observed for PALB2 c.1592delT OR 3.44 (95% CI 1.39 to 8.52, p = 7.1 × 10⁻⁵), PALB2 c.3113G>A OR 4.21 (95% CI 1.84 to 9.60, p = 6.9 × 10⁻⁸) and ATM c.7271T>G OR 11.0 (95% CI 1.42 to 85.7, p = 0.0012). We also found evidence of association with breast cancer risk for three variants in CHEK2, c.349A>G OR 2.26 (95% CI 1.29 to 3.95), c.1036C>T OR 5.06 (95% CI 1.09 to 23.5) and c.538C>T OR 1.33 (95% CI 1.05 to 1.67) (p ≤ 0.017). Evidence for prostate cancer risk was observed for CHEK2 c.1343T>G OR 3.03 (95% CI 1.53 to 6.03, p = 0.0006) for African men and CHEK2 c.1312G>T OR 2.21 (95% CI 1.06 to 4.63, p = 0.030) for European men. No evidence of association with ovarian cancer was found for any of these variants.Conclusions: This report adds to accumulating evidence that at least some variants in these genes are associated with an increased risk of breast cancer that is clinically important.Abstract
Background: The rarity of mutations in PALB2, CHEK2 and ATM make it difficult to estimate precisely associated cancer risks. Population-based family studies have provided evidence that at least some of these mutations are associated with breast cancer risk as high as those associated with rare BRCA2 mutations. We aimed to estimate the relative risks associated with specific rare variants in PALB2, CHEK2 and ATM via a multicentre case-control study.
Methods: We genotyped 10 rare mutations using the custom iCOGS array: PALB2 c.1592delT, c.2816T>G and c.3113G>A, CHEK2 c.349A>G, c.538C>T, c.715G>A, c.1036C>T, c.1312G>T, and c.1343T>G and ATM c.7271T>G. We assessed associations with breast cancer risk (42 671 cases and 42 164 controls), as well as prostate (22 301 cases and 22 320 controls) and ovarian (14 542 cases and 23 491 controls) cancer risk, for each variant.
Results: For European women, strong evidence of association with breast cancer risk was observed for PALB2 c.1592delT OR 3.44 (95% CI 1.39 to 8.52, p = 7.1 × 10⁻⁵), PALB2 c.3113G>A OR 4.21 (95% CI 1.84 to 9.60, p = 6.9 × 10⁻⁸) and ATM c.7271T>G OR 11.0 (95% CI 1.42 to 85.7, p = 0.0012). We also found evidence of association with breast cancer risk for three variants in CHEK2, c.349A>G OR 2.26 (95% CI 1.29 to 3.95), c.1036C>T OR 5.06 (95% CI 1.09 to 23.5) and c.538C>T OR 1.33 (95% CI 1.05 to 1.67) (p ≤ 0.017). Evidence for prostate cancer risk was observed for CHEK2 c.1343T>G OR 3.03 (95% CI 1.53 to 6.03, p = 0.0006) for African men and CHEK2 c.1312G>T OR 2.21 (95% CI 1.06 to 4.63, p = 0.030) for European men. No evidence of association with ovarian cancer was found for any of these variants.
Conclusions: This report adds to accumulating evidence that at least some variants in these genes are associated with an increased risk of breast cancer that is clinically important
Comparison of 6q25 Breast Cancer Hits from Asian and European Genome Wide Association Studies in the Breast Cancer Association Consortium (BCAC)
Peer reviewe
Abstract P4-08-04: Abcc10 status affects proliferation, metastases and tumor sensitivity
Abstract
Background: It has been proposed that therapy-induced overexpression of ATP-binding cassette (ABC) drug efflux pumps promotes resistance in many drug-treated cancers. While early studies focused on overexpression and activity of the P-glycoprotein (Pgp) pump, a structurally distinct group of ABC efflux pumps, known as the Multidrug Resistance Proteins (MRPs;ABCCs), have been gaining increasing attention as alternative sources of resistance. There are 9 ABCC family members (ABCC1-6, 10–12), and we have previously shown that ABCC10 is unique because it confers resistance to a wide variety of anticancer agents including taxanes, vinca alkaloids and nucleoside-based analogs (Hopper-Borge et al, 2004, Hopper-Borge et al, 2009). Importantly we have shown that Abcc10 null mice are sensitized to taxanes (Hopper-Borge et al, Cancer Research, 2011). This is the first transporter whose loss results in in vivo tissue sensitivity to taxanes.
Methods & Results: We recently bred a PyVmT mammary tumor model to our Abcc10 gene disrupted mice to investigate Abcc10's in vivo activities regarding breast cancer resistance mechanisms. We have observed that Abcc10+/+ (WT) status limits the rate of tumorigenesis (p = 0.020) and that WT tumors are more metastatic compared to Abcc10−/− (KO), (p = 0.0489). To better understand the potential resistance mechanisms in this model we determined the expression levels of relevant transporters with qRT-PCR and found no significant differences between WT and KO. The PI3K-AKT-mTOR, a major signaling pathway involved in breast cancer progression has been connected to ABCCs (Tazzari, et al, 2007), and we observed upregulation of AKT in KO versus WT mammary tumor cell lines via western analyses. Therefore, we decided to ask if Abcc10 status affects proliferation, attachment, and/or migration (CyQuant, Invitrogen and xCELLigence, Roche). We showed that WT cell lines grow 3 times slower compared to KO. For migration kinetic we observed that KO cell lines were more active compared to WT.
To determine the impact of Abcc10 loss in vivo we injected SCID mice with 3 WT or KO mammary tumor derived cell lines and treated tumors with docetaxel or vehicle. Tumors derived from WT and KO mice were both responsive to docetaxel (WT, p = 0.003 and KO, p = 0.001). However, over 21 days, the WT tumors were reduced by 50% compared to KO reduction of 86%. Kaplan-Meier survival analysis of treated/untreated SCID mice reveals that Abcc10 status is related to a poorer prognosis (KO p < 0.0001, WT p = 0.0648).
Conclusion: Here we show that Abcc10 status limits tumorigenesis (proliferation, attachment, migration) of MMTV-PyVmT mammary tumor model and Abcc10+/+ tumors are more metastatic compared to KO tumors. Thus Abcc10 may be involved in breast cancer development and progression. mRNA expression analysis of ABC transporters in mammary tumors derived cell lines reveals that other transporters do not compensate for Abcc10 loss. In vivo experiments show that treatment with docetaxel is more effective for KO tumors compared to WT tumors, suggesting Abcc10 is a breast cancer resistance factor.
Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-08-04.</jats:p
Abcc10 status affects mammary tumour growth, metastasis, and docetaxel treatment response
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