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@#[Abstract] Objective: To investigate the relationship between expression of MICA/B (MHC class I chain-related proteinA/B) and disease-free survival (DFS) of patients with HER2+(human epidermal growth factor receptor 2) breast cancer tissue. Methods: Twenty six cases of corresponding para-cancerous tissue and 100 cases of HER2+ breast cancer tissue that preserved in wax at Zhengzhou People’ s Hospital Affiliated to Southern Medical University from January 2009 to June 2010 were collected for this study. Expression of MICA/ B in these tissue samples was detected by immunohistochemistry; and the relationship between MICA/B expression with clinicopathologic features as well as DFS was analyzed with Kaplan-Meier survival curve. Results: The expression of MICA/B in adjacent paracancerous tissues was negative (0/26), however, it was highly positive in cancer tissues (92/100), and the percentage with high expression was 65%(65/100), the difference was significant (P<0.05). High MICA/B expression rate in stage I was significantly higher than that in stage Ⅱ-Ⅲ (77.55% vs 52.94%， P<0.05), and the high expression rate in stage T1 was also significantly higher than that in stage T2-T4 (75.00% vs 52.27%， P<0.05). High MICA/B expression rate in ER+, PR+ group (with positive number≥1%) was significantly lower than that in ER- , PR-group (ER： 52.38% vs 74.14%，PR： 51.35% vs 73.02%， all P<0.05). MICA/B expression was correlated with clinical stages, the expression of ER, PR and tumor size (all P<0.05), but not associated with menopausal status, histological grade and lymph node metastasis (all P>0.05). Over-expression of MICA/B was closely associated with much better 6-year DFS rate in patients no matter with or without targeted therapy (the targeted group: 90.6% vs 72.2%; the untargeted group: 78.4% vs 58.8%, all P<0.05). Conclusion: Over-expression of MICA/B in HER2+ breast cancer tissue is closely related to DFS, which may be served as a potential prognosis indicator for patients with HER2+ breast cancer.
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Objective:To explore the mechanism of the cytotoxicity of human NK cells induced by atorvastatin to colon cancer cell lines. Methods:After colon cancer cells (HCT-116,SW-480,Caco-2) were cultured with different concentrations of atorvastatin, CCK-8 assay was used to assess the effect of atorvastatin on growth of colon cancer cells. The amplification of human NK cells was induced by SCGM medium in vitro. Automatic biochemical analyzer was applied to test the cytotoxicity of NK cells to colon cancer cells which cultured with different concentration of atorvastatin. FCM was used to detect the expression rate of MICA/B on the cells. Results:(1) The cultivation of NK cells:The proportion of NK cells attained to 93. 1% from 4. 5% after cultured for 10 days. (2) The effects of atorvastatin on the growth of the colon cancer cells:After cultured with atorvastatin,the inhibition rate of HCT-116 cells was higher than that in control when the density of atorvastatin increased from 5 μmol/L to 40 μmol/L after 48 h and from 1. 25 μmol/L to 40 μmol/L after 96 h ( P<0. 05 ) . Correlation analysis showed that the concentration of atorvastatin and the growth inhibition rate of HCT-116 cells were positively correlated(r[48 h]=0. 13,r[96 h]=0. 22,P<0. 05). (3) The cytotoxicity of NK cells to colon cancer cells effected after atorvastatin: In different atorvastatin concentrations groups,the cytotoxicity of NK cells to three colon cancer cell lines was all higher than that in control ( P<0. 05 ) . The atorvastatin concentration was from 2. 5 μmol/L to 10 μmol/L for HCT-116 cells,from 5 μmol/L to 20μmol/L for SW-480 cells,and from 2. 5μmol/L to 20μmol/L for Caco-2 cells. Among the three cell lines, the cytotoxicity of NK cells to HCT116 was the highest in the same concentration. (4)NK cells by atorvastatin cutting statins 96 h,the concentration of 20 mmol/L and 40 mmol/L inhibition rate was higher than that of control group,more than other groups on NK cell growth without significant effect. ( 5 ) The impact of atorvastatin on MICA/B expression of colon cancer cells: After cultured with different concentrations of atorvastatin,the expression of MICA/B on colon cancer cells was higher than that in control(P<0. 05). The concentration was 2. 5μmol/L and 5μmol/L for HCT-116 cells,10μmol/L and 20μmol/L for SW-480 cells,and from 2. 5μmol/L to 40 μmol/L for Caco-2 cells. Conclusion:Atorvastatin could inhibit the growth of colon cancer cells (HCT-116,SW-480 and Caco-2) in a dose-dependent manner;and it could enhance the cytotoxicity of NK cells to colon cancer cells;it also could promote the expression of MICA/B of colon cancer cells,and improve the immunogenicity of colon cancer cells.
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Objective To study on the characterization of MICA/B genetic polymorphism in a northern Chinese Hunan Han population.Methods Ninty-five unrelated individuals were involved in this study and MICA/B genotypes were determined by two methods:PCR-sequence-specific primers (PCR-SSP) and PCR-sequence-based typing (PCR-SBT).Results In northern Hunan Han population,eleven MICA alleles were found,among which MICA * 010 (28.95％),MICA * 008 ∶ 01 (20.53％) and MICA * 002 ∶ 01 (15.79％) were the common alleles.Five MICA-STR(short tandem repeat) alleles were found,among which MICA * A5 (37.89％) and MICA * A5.1 (21.05％) predominated.In this population,ten MICB alleles were found.The common alleles were MICB * 005 ∶ 02/* 010 (58.42％),MICB * 002 ∶ 01 (10.00％),and MICB * 008 (7.89％).Two kinds of MICA-MICB haplotypes were MICA * 004-MICB * 004 ∶ 01 and MICA * 010-MICB * 005 ∶ 02/010 in significant linkage disequilibrium.This study also showed MICA/B gene with high polymorphism in different populations.Conclusion MICA/B alleles distribution in northern Hunan Han population with its unique characteristics.
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Objective To analyze the relationship between the expression of MHC class I chain-related gene A/B(MICA/B) on different human cancer cells and their sensitivity to NK cell cytotoxicity.Methods Hie expression MICA/B in K562,Bcap37,769P and A549 cells was measured by FACS.Isolation of NK cells were obtained by the modified RosetteSep~((R)) procedure.Cytotoxicity of NK cells at different ef0.50)%,(90.72±0.64)%,(55.59±0.55)%,and(3.84±0.10)% respectively.The purity of NK cells obtained by the modified RosetteSep~((R)) procedure was(96.52±2.42)%,whereas the cytotoxicity of NK cells against K562,Bcap39 and 769P was much higher than that of A549(P<0.01).The expression of MICA/B was significantly correlated with the cytotoxicity of NK cells at E:T ratios of 5:1,10:1 and 20:1 respectively(P<0.01).Conclusion The MICA/B expression on cancer cell lines was correlated with NK cell-mediated cytolysis and influenced the cytotoxicity of NK cells.
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Objective To investigate the relation between the expression of MICA/B in lung cancer cells and the mediastinum lymph node metastasis. Methods The samples of the lung cancer tissue as test group and the healthy tissue beside lung cancer as control group from 30 cases of patients with lung cancer were collected, and the expression of MICA/B on lung cancer cells surface were detected by flow cytometry.All patients were divided into three groups(N0, N1, N2) according to the state of lymph node metastasis, and the expression of MICA/B was analyzed among the three groups. Results The expression level of MICA/B in test group was significantly higher than that in control group[(0.3788±0.2398) %, (0.1908±0.1760) %] (P ＜0.01),however the MICA/B expression level between N0 and N1 or between N1 and N2 was not statistically different (P＞0.05), while that between N0 and N2 had statistical difference (P＜0.05). Conclusion The expression level of MICA/B on surface of lung cancer cells is high, and the MICA/B as ligand of NKG2D may play an important role in the tumor immune response. The expression of MICA/B in mediastinum metastatic lymph node from lung cancer is remarkably increased and the prognosis of patients with lymph node metastasis is poor. MICA/B could be considered as a marker of mediastinum lymph node metastasis.
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Objective:To analyze the activities of human NKG2D ligand MICA/B promoter induced by 5-Fu.Methods:The 5'-end flanking regions of MICA /B promoter and their different truncated fragments were amplified from A549 genome by PCR. The resulting amplicons were cloned into pGL3-Basic vector to generate the MICA/B luciferase reporter plasmids. All the constructs were transiently transfected A549 cells. The promoter region activities were determined by dual-luciferase reporter assays. The effect of 5-Fu on the promoter activities of MICA/B was also tested.Results and Conclusion:The 5'-end flanking regions of MICA /B promoter and five of their different truncated fragments were successfully obtained. The normalized luciferase reporter gene activities driven by the above promoters and fragments were 3.61,2.26,1.63,0.313,0.711 and 0.663 for MICA and 17.49,10.11,7.398,0.822,0.997 and 0.49 for MICB,respectively. Promoter activities in transiently transfected A549 cells treated by 20,40,80,160 and 320 μg/m of 5-Fu increased 1.69,1.48,1.62,1.55 and 1.78 fold for MICA and 1.44,1.87,1.38,1.19 and 1.25 fold for MICB. Our results suggest that 5-FU can significantly up-regulate the promoter activity of both MICA and MICB.
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Objective:To investigate the expression of NKG2D receptor on natural killer(NK)cells and the expression of its ligand MHC classⅠ-related chain A and B(MICA/B)whereby to analyze the mechanism for escaping killing were deteced by NK cells of leukemic cells.Methods:Detection of NKG2D receptor and MICA/B ligand were aleteced by flow cytometry analysis.Results:The expression of NKG2D receptor were significantly lower in both pretherapy and complete remission group,compared with that in health group(P0.05).Conclusion:NK cell function mediated by NKG2D-MICA/B was inhibited,with possibly leads to the escape of leukemic cell from NK cell cytotoxicity;And after therapy the function of NK cells mediated by MICA/B in complete remission patients may be not ameliorated indicated by farther decrease of NKG2D-cells in the patients.