The Mechanism Of Syndecan-1 Promoting Calcification In Adamantinomatous Craniopharyngioma

Background and objectiveCraniopharyngioma(CP)is a rare epithelial tumor originated from the residual cells or metaplasia of Rathke capsule during embryonic development.According to the WHO pathological classification of central nervous system tumors in 2021,they are divided into two different pathological types:adamantinomatous craniopharyngioma(ACP)and papillary craniopharyngioma(PCP).The incidence rate of craniopharyngioma is about 0.5-2/million.Adamantinomatous craniopharyngioma accounts for 90%of craniopharyngioma.The gross type is cystic or cystic solid.Calcification is the most typical pathological feature of adamantinomatous craniopharyngioma.Adamantinomatous craniopharyngioma is a WHO grade I benign tumor.At present,total resection is still the main treatment method.However,the postoperative imaging follow-up data of a large number of cases of craniopharyngioma show that the long-term recurrence rate of total resection cases is still as high as 2040%,which is recognized as a tumor with "benign pathology and malignant clinical outcome".On the one hand,calcification represents the prognosis of benign tumors and cell aging.At the same time,calcification can promote peritumoral inflammation,lead to serious complications,increase the difficulty of surgical resection and increase the probability of postoperative tumor recurrence.The molecule of syndecan-1(SDC1)was selected for research through Shengxin analysis and hub gene screening.It is often expressed in epithelial cells.It is an important component of stroma and plasma membrane.It is a classical receptor and co receptor of growth factor,angiogenesis factor and chemokine.It is involved in the processes of cell differentiation,proliferation,adhesion,migration and angiogenesis.Previous reports have found that SDCl is expressed in adamantinomatous craniopharyngioma,while in human mesenchymal stem cells(hMSCs),SDC1 is involved in the process of adipogenic and osteogenic differentiation.It has been found that knocking down the expression of SDC1 in stem cells will inhibit osteogenic differentiation and enhance fat production.Bone morphogenetic protein-2(BMP2)is a growth factor with osteogenic induction ability.We found that BMP2 plays an important role in the calcification of adamantinomatous cell craniopharyngioma.To sum up,previous literature and our previous work have shown that SDC1 and BMP2 are involved in the process of tumor and cell calcification,but the specific regulatory mechanism of SDC1 and BMP2 in the formation of calcification of adamantinomatous craniopharyngioma is still unclear.Therefore,the research of this subject is carried out.Research methods and contentsDifferential expression gene profile construction,protein interaction network construction,he staining,paraffin section immunohistochemistry,immunofluorescence staining,immortalized cell culture,lentivirus transfection,Western blot,real-time fluorescence quantitative PCR,paraffin section,liposome Si RNA transfection,protein extraction,alizarin red calcium salt staining.Statistical methodThe construction of differentially expressed gene profile in this study was completed by R software based on R language platform(version 3.6.1).SPSS version 21.0 statistical software and graphpad prism version 8.0.2 were used to statistically analyze the above other experimental data.Two independent samples t-test was used for the comparison between groupsOne way ANOVA was used for comparison.All the above definitions(P<0.05)indicate that the difference is statistically significant.ResultsIn this study,bioinformatics analysis methods were used to analyze THE GEO database GSE94349 and GSE26966 chips to construct the differential expression gene profile of the enamel craniopharyngioma.Hub genes were screened by further analysis of up-regulated differential genes.Syndecan-1 was widely expressed in enamel craniopharyngioma and mainly distributed in turbomachinoid cells and astroreticular cells in clinical samples.At the same time,clinical data collection and immunostaining showed a positive correlation between Syndecan-1 and the calcification degree of the enamel craniopharyngioma.The effect of syndecan-1 on osteoblastic differentiation of enamel craniopharyngioma was confirmed by silencing and overexpression of syndecan-1.Finally,osteogenic differentiation induction and alizarin red staining of the cells confirmed that the formation of tumor calcification was promoted by BMP2/Syndecan1 positive feedback loop.ConclusionIt is the first time to clarify the important role of syndecan-1 in regulating the process of osteogenic differentiation and the production of calcium nodules in adamantinomatous craniopharyngioma.Further clarify that BMP2/syndecan-1 positive feedback loop plays an important role in the process of calcification and osteogenic differentiation of adamantinomatous craniopharyngioma,and provide a theoretical basis for the molecular mechanism of calcification of adamantinomatous craniopharyngioma.It is proved again that the immortalized cell line of adamantinomatous craniopharyngioma has the potential of osteogenic differentiation as a tool cell.