Study On Hypoxia Promotes The Paracrine SRGN Of CAF To Enhance The Stemness Of HNSCC Through Wnt/β-catenin Pathway

[Objective]To explore how hypoxic microenvironment affects the paracrine pathway of CAF and affects HNSCC.[Methods](1)Situ model of oral squamous cell carcinoma and PDX model were established.Immunohistochemistry was used to detect the presence of hypoxia in HNSCC.Using TCGA database for Survival Analysis.The correlation between SRGN and poor prognosis of HNSCC and the expression of SRGN and CD44 were analyzed with clinicopathological data;(2)CAF was obtained from the HNSCC tissues by primary cultured.q-PCR,WB and ELISA were used to detect the effect of hypoxic environment on the expression of SRGN in CAF and tumor cells.Immunofluorescence was used to detect of the nuclear displacement of β-catenin;(3)WB,q-PCR,flow cytometry,shRNA technology were used to detect the effect of paracrine SRGN secreted by CAF on the phenotype of tumor cells under hypoxia;(4)In animal experiments,interfering RNA technology was used to inhibit the expression of SRGN in CAF.Situ model was established by equal mixing of CAF and head and neck squamous cells.IHC was used to evaluate the effect of SRGN secreted by CAF on HNSCC.[Results](1)Hypoxic factors existed in HNSCC.TCGA database analysis found no significant correlation between SRGN and prognosis of HNSCC.The SRGN in the tumor interstitial region had a certain correlation with poor prognosis,and there was a positive correlation between SRGN and CD44 expression;(2)Hypoxic environment only promotes the expression of SRGN in CAF compared with head and neck squamous cell carcinoma cells;(3)Paracrine SRGN of CAF promotes the expression of CD44 in HNSCC andβ-catenin displaces into the nucleus and affects the phenotype of tumor cells;(4)CAF-expressed SRGN promotes tumor proliferation and Ki-67 expression.[Conclusion]The hypoxic microenvironment of HNSCC can promote the secretion of SRGN by CAF and the dryness and chemotherapy resistance of HNSCC through Wnt/β-catenin pathway.