ABSTRACT
Objective To investigate the effect of anti-human immunoglobulin M (IgM) on proliferation,apoptosis,cell cycle and tumor formation in human nasopharyngeal carcinoma HNE-1 cell line in vitro and in vivo.Methods After treatment with anti-human IgM antibody,proliferation of HNE-1 cells was observed by cell proliferation inhibition assay,apoptosis and cell cycle of HNE-1 cells were detected by flow cytometry,and apoptotic cells were detected by TUNEL staining.Nude mouse models were constructed,and were injected intraperitoneally with anti-human IgM antibodies (once every 3 days).The growth of transplanted tumor was observed once every 4 days.After the fifth injection,the expression levels of IgM and gp96 protein in transplanted tumor were observed by immunohistochemical method (streptavidin-peroxidase conjugated method,SP).Results MTS assay showed that anti-human IgM antibody can significantly inhibit the proliferation of HNE-1 cells in concentration-and time-dependent manner (P＜0.05).Flow cytometry showed that the anti-human IgM antibody promoted a significant decrease in percentage of cells in G1 phase,a significant increase in percentage of cells in S phase,and a significant increase in apoptotic rate of HNE-1 cells (P＜0.05).TUNEL staining showed that the anti-human IgM antibody promoted apoptosis of HNE-1 cells (P＜0.01).Transplantation tumor experiment showed that anti-human IgM antibody can significantly inhibit the volume and weight of transplanted tumor (P＜0.05).The immunohistochemistry showed that the expression levels of IgM and gp96 proteins in mouse transplanted tumors after intraperitoneal injection with anti-human IgM antibodies were significantly lower than those of the control group (P＜0.05).Conclusion The anti-human IgM anti-body could effectively inhibit the proliferation of HNE-1 cells,promote apoptosis,and arrest cell cycle.Anti-human IgM antibody could also inhibit the growth of transplanted tumor in nude mouse,which might be related to inhibition of the expressions of IgM and gp96 proteins.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the infiltration and prognostic significance of tumor-infiltrating mast cells (TIMs) in nasopharyngeal carcinoma (NPC).</p><p><b>METHODS</b>Immunohistochemistry for tryptase was performed on 154 NPC specimens. The median value of TIM density was used as a cutoff point to separate the patient cohort into two groups with either low or high TIM infiltration. The associations between TIM and clinicopathological factors were analyzed by Mann-Whitney U text. Survival curves were plotted according to the Kaplan-Meier method. Univariate and multivariate analyses were performed using the Log-rank test and the Cox proportional hazard models, respectively. P<0.05 was considered statistically significant. All statistical analyses were conducted using SPSS 13.0.</p><p><b>RESULTS</b>TIM was mainly in the stroma of NPC and detected in all specimens. The median value of TIM density (25.60/high power field) was used as a cutoff point to separate the patient cohort into two groups with either low or high TIM infiltration. The density of TIM was positively correlated with N stage (Z=-2.193, P<0.05) and clinical stage (Z=-2.551, P<0.05). The 3-year overall survival (OS) and progression-free survival (PFS) of patients were 64.4% and 55.7% in the high TIM density group; 78.3% and 77.0% in the low TIM density group. For survival evaluation, high density of TIM was associated with worse OS and PFS (P<0.05). Multivariate Cox regression model analysis showed TIM infiltration was an independent risk factor for both OS and PFS.</p><p><b>CONCLUSIONS</b>The density of TIM in NPC increased with tumor stage. High TIM infiltration was associated with poor overall survival and progression-free survival.</p>