Preliminary Study On Expression Of HLA-B And C19orf45 In Oral Squamous Cell Carcinoma

Background:The tumor has tissue-derived specificity,which determines the biological characteristics of the tumor and the specificity of each tumor.In our previous analysis of the genome-wide exon-related sequencing of susceptibility genes in patients with oral squamous cell carcinoma,we found that human leukocyte antigen B(HLA-B)and the gene located in open reading frame 45 of chromosome 19(chromosome 19 Open reading frame 45,C19orf45)may be associated with the development of oral cancer and is an important candidate gene for oral squamous cell carcinoma.Studies have shown that tumor cells can reduce the inhibition of killer T cells(cytotox T cells)by reducing the expression of HLA-B and evade the ability of immune surveillance.Studies on C19orf45 protein have been few reported.Granzyme B(granzyme B)is an effector of killer T cells and its index is often used to measure the immunestatus of the tumor microenvironment.granzyme B is used as a index to measure of body’s anti-tumor immunity.Objectives:To detect the expression of HLA-B,C19orf45 in oral squamous cell carcinoma(OSCC)primary and metastatic tissue,and in normal OSCC and precancerous tissue,and investigate their roles in the anti-tumor immunity and the development of oral squamous cell carcinoma and its lymphatic metastasis.Methods:(1)A total of 70 patients with oral squamous cell carcinoma who came to the hospital from May 2016 to May 2017 in affiliated stomatological hospital of Guangxi Medical University were selected,and their pathological tissues were taken as OSCC group.In patients who were taken oral biopsy during the same period,10 cases of oral leukoplakia confirmed by postoperative pathological examination were taken as precancerous group and 14 cases of normal oral epithelial tissues without pathological changes as a normal control group.Immunohistochemical analysis of granzyme B,HLA-B,and C19orf45was carried on the tissue sections of primary and metastatic lesions of oral squamous cell carcinoma and normal control tissues.The expression of granzyme B was used as an index to measure of anti-tumor cellular immunity.The expression of HLA-B and C19orf45,and granzyme B of different clinical pathological index were messured and the relationship between HLA-B and C19orf45,and granzyme B was compared.(2)Protein immunoblotting(western blot)was used to detect the expression of HLA-B and C19orf45 proteins in KB oral squamous carcinoma cell line and normal oral tissues.Results:(1)The results of immunohistochemistry showed that the expression of HLA-B in normal tissues,precancerous lesions,and cancer tissues gradually decreased(P=0.008);the expression of well-differentiated OSCC was not significantly different between normal tissues and precancerous lesions,but it was significantly higher than Poorly differentiated OSCC(P=0.031).There was no significant difference between different T stages(P=0.647);there was no significant difference in HLA-B expression between primary and metastatic sites(P=0.642).However,the expression of HLA-B in the primary metastatic tumor was lower than that in the primary tumor without metastasis(P=0.069).The immunohistochemical analysis of HLA-B and granzyme B showed that the HLA-B of the primary and metastatic foci were in direct proportion to the expression of granzyme B,and the linear correlation coefficient were R~2=0.27and R~2=0.39,and were moderately related.(2)The expression of C19orf45 in oral squamous cell carcinoma was significantly higher than that in normal tissues and precancerous lesions(P=0.043).There was no significant difference in the clinicopathological parameters in oral squamous cell carcinoma in C19orf45 and granzyme B.In the immunohistochemical correlations,the expression of C19orf45 and granzyme B in the primary and metastatic lesions were not correlated.(3)The results of Western blot showed that the expression of HLA-B protein in normal oral tissue cells was higher than KB oral cancer cells;on the other hand,the expression of C19orf45 protein in normal oral tissue cells was lower than KB oral cancer cells.Conclusion:(1)The expression of HLA-B in oral cancer tissues(especially poorly differentiated)was significantly lower than that in normal tissues,precancerous lesions,and well-differentiated squamous cell carcinomas,which was related to the observed higher lymphatic metastasis rates in poorly differentiated squamous cell carcinomas.It is suggested that the weakening of HLA-B expression may be related to tumor immune escape mechanism.HLA-B expression may be used as an indicator to monitor the malignant degree and lymphatic metastasis of oral cancer.(2)HLA-B has a moderate correlation with granzyme B,while C19orf45 has no related to granzyme B.It is suggested that there may have other factors affecting the body’s anti-tumor cellular immunity beyond HLA-B,whereas C19orf45 and body tumor immunity Nothing to do.(3)C19orf45 may be related to the growth of tumor cells,but further studies are needed.