Mast Cell Infiltration And IgE Expression In Gastric Cardia Carcinoma

BackgroundGastric cardia carcinoma (GCC) is one of the most common malignant tumors inChaoshan area. Most GCC are poor differentiation, with strong invasive ability andpoor prognosis. Exploration the mechanism involved in the development of GCC willbring a potential clinical value in protecting and treating GCC. Tumor-stromainteractions are of great importance in initiation and progression of malignance. Mastcells (MC) are functional recognized as main effect cells in mediating allergicreactions, microbes and parasitic infection, but recently discovered as one of keycomponents in tumor micro-environments. Function of mast cell in developing tumorshas been highlighted by recent literature but not researched in GCC. Mast cells arenormly recruited and actived by IgE through its specific receptor. Immunoglobulin (Ig)is traditionally considered as production of mature B lymphocytes, but recentlyproved that Ig also could be detected in malignant tumor cells. Whether IgE expressedin GCC and its relationship with mast vee infilteation have not been studied.ObjectiveIn this study, we aimed to investigate the distribution of mast cells in GCC infiltratingtissue, tumor adjacent tissue, and distal normal cardia mucosa, and to evaluate theclinical pathological correlation with mast cell infiltration in GCC. Meanwhile weplan to detect IgE expression from mRNA and protein level in EC109 esophagealcancer lines, SGC7901 stomach cancer cell lines and especially in cardia cancertissue.Materials and methods 60 patients histopathologically diagnosed as GCC were selected for cancer tissue,cancer-adjacent tissue and distal normal mucosa. Immunohistochemistry andimmunofluorescence were used on to detect mast cells and IgE expression on thetissue sections. Total RNA extraction and nest RT-PCR were carried out to detect Ig Eheavy chain mRNA expression. All the data were analyzed by spss17.0 software withcorresponding stastical method.Result1. In the normal mucosa and inflammation tissue, mast cells mainly distributed in thelayer of mucosa and submucosa, while in carcinoma tissue, MC mainly located in theboundary between normal and carcinoma tissue and rare in mesenchyma of carcinoma.MC is the most in chronic inflammation, moderately in carcinoma adjacent tissue andnormal tissue, and the fewest in carcinoma tissue. Significant differences were foundbetween each two groups (F=60.01, p<0.01).2. The number of mast cells was negative ly correlated with the depth of cancerinfiltration (P<0.05). Significant differences were found between serous layer vs outerserous layer and muscular layer vs outer serous layer at the level of 0.05, but t nosignificantlly difference between muscular layer and serous layer. The number of MChad no correlation with the other clinical pathological parameters.3. The ratio of activated mast cells in normal mucosa (39.46%), tumor adjacent tissue(48.84%) and carcinoma tissue (90.85%) was significantly different at the level of0.01, and comparison between each two groups was also statistically different. (P <0.05).4. Ig E heavy chain area mRNA expressed in EC109 cell lines , SGC7901 cell linesand gastric cardia carcinoma tissue.5. Ig E protein expressed in GCC tissue and the staining intensity had a negativecorrelation with the size of tumor (p<0.01), but no correlation with the other clinicalpathological parameters.6. There was a positive correlation between the number of MC and the density of IgE expression: the correlation coefficient was 15.826 (P<0.01).Conclusion1. Mast cells mainly distributed in the layer of mucosa and submucosa in normalcardia and inflammation tissue. MC mainly exited in the boundary between normaland carcinoma tissue. The ratio of activated mast cells was significantly higher incarcinoma tissue than that in tumor adjacent tissue and normal tissue.2. The number of mast cells was negative ly correlated with the depth of cancerinfiltration, which may implied that mast cells could inhibit the growth and metastasisof GCC, and thus are recognized a protective factor.3. IgE express ed in GCC tissue, EC109 and SGC 7901 cell lines at the mRNA andprotein level4. IgE expression had a positive correlation with the count number of MC infiltration,which may implied that IgE play an important role in mast cell recruitment andactivation in GCC.