Natural killer and cytotoxic T lymphocyte-mediated cytotoxicity enhanced by genetic overexpression of MHC class I chain-related protein A in oral squamous cell carcinoma: an experimental study in vivo / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect on natural killer (NK) and cytotoxic T lymphocyte (CTL)-mediated cytotoxicity by genetic overexpression of MHC class I chain-related protein A (MICA) in oral squamous cell carcinoma (OSCC).</p><p><b>METHODS</b>The OSCC cells by genetic overexpression of MICA were detected to identify the biological features including cell growth curve, cell cycle distribution, plate clone forming rate and tumorigenicity in nude mice. The expression of natural killer group 2, member D (NKG2D) receptor and the cytotoxicity to target tumor cells of NK92 and CTL cells, which co-cultured with the transfected OSCC cells or the non-transfected or blank vector-transfected controls, were measured by flow cytometry and lactate dehydrogenase (LDH) release assay.</p><p><b>RESULTS</b>There was no difference in biological features before and after MICA gene transfection to OSCC cells. Flow cytometry and LDH release assay showed that MICA-overexpressed OSCC cells enhanced the cytotoxicity to target tumor cells and up-regulated the expression of NKG2D on NK92 and CTL (P<0.05).</p><p><b>CONCLUSION</b>MICA may be considered as a promising immunotherapy target of OSCC.</p>

Soluble major histocompatibility complex class I-related chain A in sera of patients with oral squamous cell carcinoma / 中南大学学报(医学版)

OBJECTIVE@#To examine the expression of soluble major histocompatibility complex class I-related chain A (sMICA) in the serum in patients with oral squamous cell carcinoma (OSCC) and to explore its clinicopathological significance.@*METHODS@#Seventy-eight OSCC patients were selected as an experiment group, and 19 healthy persons as a control group. The sMICA in the serum in the experiment group and the control group was detected by enzyme-linked immunosorbent assay.@*RESULTS@#The detection rate of sMICA in the serum in the experiment group was 98.7% (77/78), with the 95% confidence interval 74.30-93.95 pg/mL and the median 82.17 pg/mL, The detection rate in the control group was 94.7% (18/19), with the 95% confidence interval 29.48-50.30 pg/mL and the median 37.54 pg/mL. The sMICA in the serum in the experiment group was higher than that in the control group (P0.05).@*CONCLUSION@#The sMICA in the serum in the OSCC patients increases, and is related with the tumor size, disease stage and regional lymph node status. Determination of sMICA in the serum may provide useful information to evaluate the immune state of OSCC patients.

Construction of eukaryotic expression vector of major histocompatibility complex class I -related chain A and establishment of its stable transfected Tca8113-Tb cell line / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To construct the eukaryotic expression vector, encoding major histocompatibility complex class I-related chain A gene (MICA), for the further research of transfecting Tca8113-Tb cell line(a metastatic cell line of brain metastasis from human tongue cancer Tca8113 cells in nude mouse), and to establish a stable MICA overexpression oral squamous cell line.</p><p><b>METHODS</b>cDNA of MICA gene from pCMV-SPORT6-MICA was amplified by PCR, and subcloned into eukaryotic expression vector pEGFP-N1 marked with green fluorescent protein (GFP). The recombinant plasmid was sequenced and transfected into Tca8113-Tb cell line by lipofectamine 2000. After screen culture by G418, stable tranfected Tca8113-Tb cell line was established using definite dilution method. The expressions of GFP protein was viewed directly with fluorescence microscopy and the overexpression of MICA was identified by RT-PCR, real time PCR and immunocytochemistry.</p><p><b>RESULTS</b>The MICA gene was amplified by PCR and then cloned into the vector, whose sequence was identical to that in the GenBank. The transfected cells showed the expression of GFP. And the overexpression of MICA gene in transfected cells was detected by RT-PCR, real time PCR and immunocytochemistry.</p><p><b>CONCLUSION</b>The recombinant eukaryotic expression vector pEGFP-N1-MICA has been constructed successfully and stably expressed in Tca8113-Tb cell line, providing a foundation for further studies on the function of MICA in vitro.</p>