Breast Cancer Subtypes, The Study Of The Expression And The Effect Of Nek2B In Breast

Part1ObjectiveBreast carcinoma is of high heterogeneity. The aim of this study was to estimate relapse for patients with the major subtypes of breast cancer as classified using immunohistochemical assay, and to investigate the patterns of benefit from the therapies over the past years. The analysis of breast subtypes was the base for the therapy individually.MethodsThe study population included primary, operable2,118breast cancer patients, all non-specific infiltrative ductal carcinoma (NOS-IDC). All patients underwent local and/or systemic treatments. The clinicopathological characteristics and clinical outcomes were retrospectively reviewed. The expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor2(HER2), epidermal growth factor receptor (EGFR), and cytokeratin (CK)5/6were analyzed by immunohistochemistry. The expression of Ki-67was used in luminal A subtype.ResultsAll patients were classified into the following categories:luminal A, luminal B, HER2overexpressing, basal-like, and unclassified subtypes. Ki-67was detected in luminal A subtype. The median follow-up time was67.9months. Luminal A tumors had the lowest rate of relapse (12.7%, P<0.001), while luminal B, HER2overexpression, and basal-like subtypes were associated with an increased risk of relapse (15.7%,19.1%,20.9%). Molecular Subtypes retained independent prognostic significance (P<0.001). In luminal A subtype, adjunctive radiotherapy could decrease the risk of relapse (P=0.005), Ki67positive was a high risk factor for relapse (P<0.001), and adjuvant chemotherapies could reduce the relapse for the patients with risk factors (P<0.001). Adjuvant hormone therapy was an effective treatment for ER-positive tumors (P<0.001).Conclusion Molecular subtypes of breast cancer could robustly identify the risk of recurrence, and were significant in therapeutic decision making. The model combined subtype and clinical pathology was a significant improvement. Luminal A tumors might represent two distinct subsets which demonstrated distinct prognosis and therapy response. Part2ObjectiveTo detect the expression of Nek2B during MCF10cells representing the development and progression model of breast cancer, as well as the effects of Nek2B plasmid DNA in the precancerous cells and Nek2B siRNA in carcinomatous cells. To evaluate the treatment of Nek2B siRNA in the tumor of nude mouse, to investigate the expression of Nek2B mRNA in the patients who had received neoadjuvant chemotherapy including paclitaxel.MethodsThe multi-step simple linear progression model of breast cancer was composed of MCF10A, MCF10AT, MCF10DCIS.com and MCF10CA1. The protein expression of Nek2was evaluated by western blot. Nek2B plasmid DNA and Nek2B siRNA were transfected to MCF10cells, the expression of Nek2B mRNA after transfection was detected by PCR, flow cytometry, Immunofluorescence, clone formation test, MTT test were used to investigate the difference between the control groups and the transfected groups. Nek2B siRNA and paclitaxel were treated in the xenografts of nude mouse model which were subcutaneous implanted by MCF10CA1cells. To analyze the relationship between the expression of Nek2B mRNA and the clinical pathology factors of patients who had received neoadjuvant chemotherapy including paclitaxel.Results1. Nek2and Nek2B were hardly expressed in the precancerous cells MCF10A, MCF10AT and were highly expressed in carcinomatous cells MCF10DCIS.com, MCF10CA1.2.After transfecting of Nek2B plasmid DNA in the precancerous cells, cell cycles and centrosome had no obviously change between the transfected groups and the control groups (P>0.05), after transfecting Nek2B siRNA in the precancerous cells, many polykaryocyte were emerged in transfected MCF10DCIS.com cells (P<0.05), the ability of proliferation were decreased in transfected MCF10CA1cells, and the number of dead cells were more than control group after the treatment of paclitaxel by different concentration for24h.3. In nude mouse model, the grow of tumors in the group of Nek2B siRNA were lower than those in PBS and controls(P<0.05). the grow of tumors in the group of Nek2B siRNA associated paclitaxel were lower than those in Nek2B siRNA group(P <0.05). the size and shapes of the cells in the group of Nek2B siRNA associated paclitaxel were not uniformity, more cellular necrosis and the cells were atonic in general than the control group(P<0.05).4. The patients who had received neoadjuvant chemotherapy including paclitaxel were divided into four groups,9cases were pCR,28cases were PR,11cases were SD,14cases were PD, in the group of Nek2B highly expressed patients,15.8%of patients came to PR while52.6%to PD (P<0.01) The expression of Nek2B mRNA had positive correlation with lymph node status, histology grade and the expression of Ki67(P<0.05), and negative with the tumor size, the status of HER2and the status of ER/PR(P>0.05).Conclusion1. Nek2B could play an role in the development and progression of breast carcinoma, it maybe the marker of poor differentiation.2. Nek2B siRNA associated paclitaxel could depress the grow of tumors in nude mouse, Nek2B may be the novel potential therapy target of breast carcinoma, especially to those who were triple negative breast cancer and those who had resisted to paclitaxel.