Expression And Clinicopathological Study Of Polycystin And MTOR Pathway Proteins In Ameloblastoma

Objective: Polycystin is a novel membrane receptor that senses external signals and transmits them into cells,thereby influencing the biological behavior of tumor cells.mTOR is a serine/threonine protein kinase,which can obtain signals from amino acids,nutrients,growth factors,and regulate a variety of basic cellular processes,including protein synthesis,growth,metabolism,aging,regeneration,and autophagy.The role of polycystins in oral and maxillofacial tumors and the regulatory mechanism of polycystins and mTOR in ameloblastoma are rarely studied.Therefore,the present research was to study the expression and distribution of polycystin 1(PC-1),polycystin2(PC-2),mTOR,and phospho-mTOR(p-mTOR)in Ameloblasto-ma(AB),compared with odontogenic keratocyst(OKC)and dentigerous cyst(DC).The results are to provide clues for the occurrence and development mechanism of AB and finding new treatment methods.Methods: Sixty-two cases of tissue wax blocks from 2016 to 2020 were selected from the Department of Oral and Maxillofacial Surgery of Stomatology Hospital of XX,and 30 cases in the ameloblastoma group(AB),including 17 males and 13 females,aged from 15 to 52 years old,with an average age of 24.15 years old.20 cases of odontogenic keratocyst group(OKC),including 10 males and 10 females,aged from 11 to 67 years old,with an average of 33.29 years old.There were 12 patients in the dentigerous cyst group(DC),including 8 males and 4 females,aged from 8 to 69 years old,with an average age of 30.25 years old.In each group,HE staining and immunohistochemical staining were used to detect the expression and distribution of PC-1,PC-2,mTOR,and p-mTOR in the three diseases.Statistical software SPSS 21 was used for statistical analysis of the results.Results: PC-1,PC-2,and mTOR were highly expressed in AB and the positive rates of immunohistochemical staining were 66.7%,90%,and 73.3%,respectively,while the expression in OKC and DC is low.The positive expressions of PC-1,PC-2,and mTOR in AB were mainly located in the cytoplasm and cell membrane of peripheral ameloblast-like cells and stellate reticulum cells of tumor epithelial island,and in OKC,mainly located in the cytoplasm and cell membrane of epithelial lining cells.The positive immunohistochemical staining rates of PC-1 in OKC and DC were 35% and33.3%,respectively.The positive immunohistochemical staining rates of PC-2in OKC and DC were 55% and 50%,respectively.And the immunohisto-chemical staining positive rates of mTOR in OKC and DC were both 25%.P-mTOR was also highly expressed in AB,OKC,and DC,with positive rates of 83.3%,95%,and 66.7%,respectively.The expressions of PC-1,PC-2,and mTOR in AB were different from those in OKC and DC(P < 0.05).while there was no significant difference in the expression of p-mTOR in AB,OKC,and DC(P > 0.05).Conclusions:1.The expressions of PC-1,PC-2,and mTOR proteins in ameloblastoma were mainly located in the cytoplasm and cell membrane of peripheral ameloblast-like cells and stellate reticulum cells of tumor epithelial island;2.The expressions of PC-1,PC-2 and mTOR in ameloblastoma were significantly higher than those in odontogenic keratocyst and dentigerous cyst;3.The expression of PC-2 and p-mTOR in ameloblastoma is correlated,suggesting that PC is related to the occurrence,development and biological behavior of ameloblastoma,and may be involved in regulating the pathophysiological process of ameloblastoma through mTOR pathway.