Heat Shock Factor 1 Reprograms Cancer-associated Fibroblasts To Promote The Invasion And Metastasis In Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma(OSCC)is a common malignancy in oral and maxillofacial area.Local invasion and distant metastasis are the main causes of death.Studies have shown that the development of the tumor depends on the malignant proliferation of cancer cells,but also the interaction of cancer cells and tumor microenvironment,microenvironment is closely related to the invasion,metastasis and prognosis of OSCC.Career associated fibroblasts(CAFs)are the most important cells in the microenvironment of OSCC.They can remodel the extracellular matrix(ECM),induce angiogenesis,epithelial mesenchymal transition(EMT),immunosuppression to promote the invasion and metastasis of OSCC.It is concluded that heat shock factor 1(HSF1)plays a key role in the invasion and metastasis of cancer cells.Objective:To investigate the role of HSF1 in CAFs and promoting the invasion and metastasis of tumor cells in OSCCMethods:Firstly,the immunohistochemical staining method was performed to investigate the expression of HSF1 and ?-SMA in 121 cases of OSCC specimens.The relationship between HSF1 and ?-SMA with clinicopathological parameters and prognosis were analyzed statistically.The method of tissue block was used to isolate and culture CAFs and NFs.CAFs and NFs were identified by real time RT-PCR,immunoblotting and immunofluorescence.The cell indirect co-culture,scratch test and transwell assay were used to investigate the effect of invasion and metastasis on oral cancer cells.Then,on the basis of this,HSF1 interference vector was constructed and transfected into CAFs to detect the phenotype changes and their effects on the invasion and metastasis of OSCC.Results:Studies showed that among the 121 cases of OSCC tissue,the expression of HSF1 in cancer cells was high in 68 cases,in stromal fibroblasts was high in 40 cases,and a-SMA was high in 80 cases.The expression of HSF1 in oral cancer cells was positively correlated with pathological grade,recurrence and death.The high expression of HSF1 in stromal fibroblasts was positively correlated with tumor recurrence and death.a-SMA was significantly correlated with T,N,clinical stage,pathological grade,recurrence and death.Correlation analysis showed a statistically significant correlation between the expression of HSF1 in cancer cells/stromal fibroblasts and a-SMA,and there was also a statistically significant correlation between HSF1 in cancer cells and stromal fibroblasts.Furthermore,the patients with higher expression of HSF1 in cancer cells/stromal fibroblasts and a-SMA had shorter survival time in OSCC.Univariate and multivariate analysis showed that the expression of HSF1 in stromal fibroblasts was significantly associated with poor prognosis,suggesting that it could be an independent predictor of prognosis in OSCC.In vitro results showed that CAFs and NFs were successfully obtained from fresh human OSCC specimens after surgical resection.There were significant differences in both gene and protein expression level.Compared with NFs,CAFs changed the morphology,migration and invasion ability of Cal27,CAFs can promote the invasion and metastasis of oral cancer cells.Histological and molecular biological experiments showed that high expression of HSF1 in CAFs.After knockdown of HSF1,the expression of FAP and FSP-1 of CAFs markers decreased,but no significant changes in a-SMA.Meanwhile,the effect of CAFs on oral cancer cells was reversible.Conclusions:The expression of CAFs in HSF1 plays an important role in the invasion and metastasis of OSCC,which may be a prognostic indicator of OSCC.