Effect of FCGR3A Polymorphisms on Antibody-dependent Cetuximab-mediated Cytotoxicity in A549 Cells / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the effect of FCGR3A polymorphisms on the antibody-dependent cell-mediated cytotoxicity (ADCC) activity induced by cetuximab against A549 cells.</p><p><b>METHODS</b>A549 cell line was used as target cells and NKTm cells as effector cells. FCGR3A polymorphisms were detected by direct sequencing. The ADCC activity mediated by cetuximab was assessed by CCK-8 assay.</p><p><b>RESULTS</b>Three genotypes of FCGR3A were detected:V/V,V/F,and F/F. The ADCC activity of NKTm cells with these three different genotypes mediated by cetuximab were significantly different (P=0.0015). NKTm cells with FCGR3A-158V/V genotypes had significantly higher ADCC activity than FCGR3A-V/F or F/F genotypes (P<0.01),whereas the ADCC activity between V/F and F/F genotype showed no statistical significance(P>0.05).</p><p><b>CONCLUSION</b>FCGR3A polymorphisms have an impact on ADCC activity mediated by cetuximab in NKTm cells.</p>

Diagnostic Value of Combining Permeability with T1 Perfusion Parameters in Quantitative Dynamic Contrast-enhanced Magnetic Resonance Imaging for Glioma Grading / 中国医学科学院学报

<p><b>UNLABELLED</b>OBJECTIVE To investigate the diagnostic value of combining permeability with T1 perfusion parameters in quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in glioma grading.</p><p><b>METHODS</b>Magnetic resonance imaging was performed in 16 patients with high grade gliomas (HGG) and 12 patients with low grade gliomas(LGG) confirmed by pathology. The permeability was quantitatively analyzed and the T1 perfusion parameters of the tumor were calculated by the pharmacokinetic model,including volume transfer constant (K(trans)),volume fraction of extravascular extracellular space (ve),reflux constant (kep),fractional plasma volume (vp),cerebral blood flow (CBF),cerebral blood volume (CBV),and mean transit time (MTT). A t-test was used to calculate the statistical significance of quantitative analysis parameters between HGG and LGG. The receiver operating characteristic curve analysis was also performed for evaluating the sensitivity,specificity,and area under curve (AUC) of the permeability parameters and perfusion parameters and the combination of these parameters.</p><p><b>RESULTS</b>The differences of the K(trans),ve,CBF,and CBV values [(0.276<0.164)/min vs. (0.084<0.044)/min;0.486<0.191 vs. 0.274<0.132;(1.755<1.164)ml/(g·min) vs. (0.761<0.625) ml/(g·min);(0.204<0.101) ml/g vs. (0.115<0.097)ml/g] were statistically significant (t=3.934,3.293,2.672,2.338,P<0.05) between HGG and LGG. The differences of the kep,vp, and MTT value [(1.632<1.204)/min vs. (1.537<1.194)/min;0.114<0.107 vs. 0.055<0.039;(0.128<0.070)min vs. (0.145<0.066)min] were not statistically significant (t=0.208,1.823,0.688,P>0.05). When the K(trans) value was 0.105/min,the AUC was the largest (0.919) by the single parameter in glioma grading,and meanwhile the sensitivity and specificity were 87.5% and 83.3%,respectively. When the ve-CBF value was 0.631,the AUC was the largest (0.974) by the multiple parameter,and meanwhile the sensitivity and specificity were 93.7% and 100.0%,respectively.</p><p><b>CONCLUSION</b>Combining permeability with perfusion parameters in quantitative DCE-MRI can improve the accuracy of the glioma grading.</p>

Role of epidermal growth factor receptor expression level in cetuximab cytotoxicity and antibody-dependent cell-mediated cytotoxicity effect against A549 lung cancer cell line / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the role of epidermal growth factor receptor (EGFR) expression level in cetuximab cytotoxicity and antibody-dependent cell-mediated cytotoxicity (ADCC) effect against A549 lung cancer cell line.</p><p><b>METHODS</b>A549 cell line and NKTm cells were used as the target cell and the effector cell, respectively. pEGFR-EGFP plasmids were transfected into A549 cells by nucleofector method. EGFR expression levels were measured by immunohistochemistry. The ADCC activity induced by cetuximab was assessed by cell counting kit-8 assay.</p><p><b>RESULTS</b>A549 cells transfected with pEGFR-EGFP plasmids expressed higher level of EGFR protein on membrane and were more sensitive to ADCC activity mediated by cetuximab (P<0.05). The inhibition rate of A549 cells showed no significant difference between transfection group and wild-type group when treated with cetuximab alone (P> 0.05).</p><p><b>CONCLUSION</b>EGFR expression level influences the sensitivity of A549 lung cancer cell line to ADCC activity mediated by cetuximab but not to cetuximab alone.</p>

Detection of T lymphocyte subsets in the peripheral blood of patients with advanced lung adenocarcinoma / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the CD4+CD25+ regulatory T cells (Treg) and other lymphocyte subsets in the peripheral blood of patients with advanced lung adenocarcinoma.</p><p><b>METHODS</b>Peripheral blood samples were obtained from 64 patients with advanced lung adenocarcinoma (case group) and analyzed by flow cytometry. The ratios of CD4+CD25+Treg T cells and other T lymphocyte subsets in peripheral blood were compared with those from 33 healthy controls (control group).</p><p><b>RESULTS</b>The percentages of CD3+ and CD3+CD4+ were (66.5±11.0)% and (37.7±10.6)% respectively in the peripheral blood of the case group, which were significantly lower than those [(72.0±6.0)% and (42.0±6.4)%] in the control group (t=-3.2,-2.4; P=0.020, 0.015, respectively). The ratio of CD4+ CD25+ Treg cells in case group (10.5±4.0)% was significantly higher than that [(8.4±3.5)%] in the control group (t=-2.2, P=0.013). CD4+/CD8+ value of case group (1.4±0.8) was significantly lower than that (1.8±0.7) in control group(t=-2.2, P=0.029). CD3+CD8+, CD8+CD28-, and CD8+CD28+ showed no significant differences (all P>0.05). Smoking, differentiation grade, and size of the tumor showed no association with the function damage of T lymphocyte subsets, while the carcino-embryonic antigen level did.</p><p><b>CONCLUSIONS</b>In patients with advanced lung adenocarcinoma, Treg increases and CD4+/CD8+ decreases, suggesting remarkably suppressed immune functions. However, more research is warranted to validate the association of T cells subset dysfunction with smoking, differentiation grade, and size of tumor.</p>

Antitumor effect of natural killer cells in vitro by blocking transforming growth factor-β signaling / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the antitumor effect of natural killer (NK) cells on human colorectal cancer cells HT-29 in vitro by blocking transforming growth factor-β (TGF-β) signaling in NK cells transfected with vector containing dominant negative TGF-β type 2 receptor (DNTβR2).</p><p><b>METHODS</b>TGF-β1 was added at the final concentration of 10 ng/ml for HT-29 cells. Primary NK cells were transfected with recombinant plasmid pIRES2-AcGFP-DNTβR2 and control plasmid pIRES2-AcGFP using Amaxa Nucleofector technology respectively. The cytotoxicity of these two types of NK cells to HT-29 cells was detected and analyzed by cell counting kit-8.</p><p><b>RESULTS</b>The transfection efficiency of primary NK cells was 18.85% for the plasmid pIRES2-AcGFP-DNTβR2 and 35.28% for the control plasmid pIRES2-AcGFP. The expression of DNTβR2 in NK cells was confirmed by Western blotting and RT-PCR. Primary NK cells displayed significantly lower cytotoxicity against HT-29 cells incubated with TGF-β1 than that without TGF-β1 (effect-target cell ratio 10:1,14.40%∓ 2.00% vs. 26.14% ∓ 2.50%, P > 0.05; effect-target cell ratio 20:1, 19.18% ∓ 2.49% vs. 40.81% ∓ 3.50%, P > 0.05). The cytotoxicity of NK cells transfected with DNTβR2 vector was significantly higher than that with control vector against HT-29 cells cultured with 10 ng/ml TGF-β1 (effect-target cell ratio 10:1, 21.17% ∓ 2.49% vs. 11.48% ∓ 1.11% ,P > 0.05; and effect-target cell ratio 20:1, 35.30% ∓ 3.78% vs. 17.19% ∓ 2.29%, P > 0.05).</p><p><b>CONCLUSION</b>NK cells transfected with DNTβR2 vector show better antitumor effect, which may provide new method for NK-based adoptive immunotherapy for cancer.</p>