Deletion of Chromosome 11q Predicts Response to Anthracycline-Based Chemotherapy in Early Breast Cancer
Division of Oncology, Center for Applied Medical Research, University of Navarra, Pamplona, and Department of Hematology and Medical Oncology, Hospital Clinico, University of Valencia, Spain. Cancer Research
(Impact Factor: 9.33).
02/2007; 67(2):818-26. DOI: 10.1158/0008-5472.CAN-06-3307
Despite the recent consensus on the eligibility of adjuvant systemic therapy in patients with lymph node-negative breast cancer (NNBC) based on clinicopathologic criteria, specific biological markers are needed to predict sensitivity to the different available therapeutic options. We examined the feasibility of developing a genomic predictor of chemotherapy response and recurrence risk in 185 patients with NNBC using assembled arrays containing 2,460 bacterial artificial chromosome clones for scanning the genome for DNA copy number changes. After surgery, 90 patients received anthracycline-based chemotherapy, whereas 95 did not. Tamoxifen was administered to patients with hormone receptor-positive tumors. The association of genomic and clinicopathologic data and outcome was computed using Cox proportional hazard models and multiple testing adjustment procedures. Analysis of NNBC genomes revealed a common genomic signature. Specific DNA copy number aberrations were associated with hormonal receptor status, but not with other clinicopathologic variables. In patients treated with chemotherapy, none of the genomic changes were significantly correlated with recurrence. In patients not receiving chemotherapy, deletion of eight bacterial artificial chromosome clones clustered to chromosome 11q was independently associated with relapse (disease-free survival at 10 years+/-SE, 40%+/-14% versus 86%+/-6%; P<0.0001). The 54 patients with deletion of 11q (29%) did not present more aggressive clinicopathologic features than those without 11q loss. The adverse influence of 11q deletion on clinical outcome was confirmed in an independent validation series of 88 patients with NNBC. Our data suggests that patients with NNBC with the 11q deletion might benefit from anthracycline-based chemotherapy despite other clinical, pathologic, or genetic features. However, these initial findings should be evaluated in randomized clinical trials.
Available from: Ping Wang
- "A strong association between miRNAs and the acquisition of MDR by tumor cells has
been established in previous studies (15-20,26). In the present study, seven miRNAs were differentially
expressed when Hep-2 cells were compared to Hep-2/v cells (Table 1). "
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ABSTRACT: Multidrug resistance (MDR) poses a serious impediment to the success of chemotherapy for laryngeal cancer. To identify microRNAs and mRNAs associated with MDR of human laryngeal cancer Hep-2 cells, we developed a multidrug-resistant human laryngeal cancer subline, designated Hep-2/v, by exposing Hep-2 cells to stepwise increasing concentrations of vincristine (0.02-0.96 µM). Microarray assays were performed to compare the microRNA and mRNA expression profiles of Hep-2 and Hep-2/v cells. Compared to Hep-2 cells, Hep-2/v cells were more resistant to chemotherapy drugs (∼45-fold more resistant to vincristine, 5.1-fold more resistant to cisplatin, and 5.6-fold more resistant to 5-fluorouracil) and had a longer doubling time (42.33±1.76 vs 28.75±1.12 h, P<0.05), higher percentage of cells in G0/G1 phase (80.98±0.52 vs 69.14±0.89, P<0.05), increased efflux of rhodamine 123 (95.97±0.56 vs 12.40±0.44%, P<0.01), and up-regulated MDR1 expression. A total of 7 microRNAs and 605 mRNAs were differentially expressed between the two cell types. Of the differentially expressed mRNAs identified, regulator of G-protein signaling 10, high-temperature requirement protein A1, and nuclear protein 1 were found to be the putative targets of the differentially expressed microRNAs identified. These findings may open a new avenue for clarifying the mechanisms responsible for MDR in laryngeal cancer.
Available from: Marta Gromicho
- "Also, miR-125 was down regulated in the MCF-7DOX- resistant cells, in support of Climent et al., who suggested that loss of chromosome 11q in breast cancer made cells more responsive to chemotherapy. These authors went on to suggest that deletion of the 11q region targets the miR- 125b-1, which is specifically down-regulated in breast cancer, may potentially regulate oncogenes such as ETS1. "
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ABSTRACT: Cellular drug resistance is a major obstacle in cancer therapy. Mechanisms of resistance can be associated with altered expression of ATP-binding cassette (ABC) family of transporters on cell membrane transporters, the most common cause of multi-drug resistance (MDR), but can also include alterations of DNA repair pathways, resistance to apoptosis and target modifications. Anti-cancer treatments may be divided into different categories based on their purpose and action: chemotherapeutic agents damage and kill dividing cells; hormonal treatments prevent cancer cells from receiving signals essential for their growth; targeted drugs are a relatively new cancer treatment that targets specific proteins and pathways that are limited primarily to cancer cells or that are much more prevalent in cancer cells; and antibodies function by either depriving the cancer cells of necessary signals or by causing their direct death. In any case, resistance to anticancer therapies leads to poor prognosis of patients. Thus, identification of novel molecular targets is critical in development of new, efficient and specific cancer drugs. The aim of this review is to describe the impact of genomics in studying some of the most critical pathways involved in cancer drug resistance and in improving drug development. We shall also focus on the emerging role of microRNAs, as key gene expression regulators, in drug resistance. Finally, we shall address the specific mechanisms involved in resistance to tyrosine kinase inhibitors in chronic myeloid leukemia.
Available from: Christophe B Poulet
- "Structural aberrations involving 11q are among the most common aberrations in a number of cancers. Indeed, chromosome 11q deletion has been characterized in a number of cancers, including leukemia , pancreatic cancer , neuroblastoma  and breast cancer . "
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ABSTRACT: Bone marrow stromal cells are adult multipotent cells that represent an attractive tool in cellular therapy strategies. Several studies have reported that in vitro passaging of mesenchymal stem cells alters the functional and biological properties of those cells, leading to the accumulation of genetic aberrations. Recent studies described bone marrow stromal cells (BMSC) as mixed populations of cells including mesenchymal (MSC) and neural crest stem cells (NCSC). Here, we report the transformation of NCSC into tumorigenic cells, after in vitro long-term passaging. Indeed, the characterization of 6 neural crest-derived clones revealed the presence of one tumorigenic clone. Transcriptomic analyses of this clone highlighted, among others, numerous cell cycle checkpoint modifications and chromosome 11q down-regulation (suggesting a deletion of chromosome 11q) compared with the other clones. Moreover, unsupervised analysis such as a dendrogram generated after agglomerative hierarchical clustering comparing several transcriptomic data showed important similarities between the tumorigenic neural crest-derived clone and mammary tumor cell lines. Altogether, it appeared that NCSC isolated from adult bone marrow represents a potential danger for cellular therapy, and consequently, we recommend that phenotypic, functional and genetic assays should be performed on bone marrow mesenchymal and neural crest stem cells before in vivo use, to demonstrate whether their biological properties, after ex vivo expansion, remain suitable for clinical application.
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