Research On The Correlation Between Carcinoma-associated Fibroblasts And The Differentiation Of Head And Neck Squamous Cell Carcinoma Cells

Objective: Head and neck squamous cell carcinoma(HNSCC)is a common malignancy in the head and neck region. It tends to metastasize and shows a high mortality rate. Cancer stem cells(CSCs) constitute unique subsets of cells by their exclusive ability to regenerate the tumor from a limited number of cells. Cancer-associate fibroblasts(CAFs) belong to a subpopulation of stromal cells in tumor microenvironment. CAFs play an important role in cancer development and progression. Our study aimed to investigate the distribution and biomarkers of CSCs in HNSCC. Then the relationship of CAFs and the differentiation of HNSCC cells in vitro will be studied.Methods: This study included 17 cases of HNSCC tissues. The expression of CD44, Aldehyde dehydrogenase-1(ALDH1), CD133, α-SMA was examined by immunohistochemical staining in HNSCC tissues. ImagePro Plus 6.0 software was used to quantify the expression level of each antibody. SPSS17.0 was used for statistical analysis. This study used two kinds of HNSCC cells: UM-SCC6 and Primary SCC cell(PSCC). Primary CAFs and PSCC were isolated from HNSCC tissues. UM-SCC6 and PSCC were cultured in three conditions: normal culture, CAFs conditioned medium(CAF-CM), and coculture with CAFs. CAF-CM was collected and centrifuged from medium cultured CAFs. Coculture of UM-SCC6 and PSCC cells with CAFs was performed with the ratio 1:10. The expression of CD44 and ALDH1 in UMSCC-6 and PSCC cells was examined by immunofluorescence staining.Result: The expressions of CD44, ALDH1 and α-SMA were observed in some cancer cells in HNSCC, while CD133 expression showed negative in all the HNSCC samples. The expression of CD44 and α-SMA increased significantly with the decrease of HNSCC differentiation level. The expression of ALDH1 showed no significant difference between different HNSCC. The expression level of CD44 correlated with that of α-SMA significantly. These results suggest that CD44 and ALDH1 can be used as biomarkers of CSCs of HNSCC. We examined the expression of CD44 and ALDH1 in UM-SCC6 and PSCC cells. It was found that CD44 and ALDH1 showed negative in both UM-SCC6 and PSCC cells under normal culture condition. By contrast, some UM-SCC6 and PSCC cells expressed CD44 and ALDH1 when they were cultured in CAF-CM or co-cultured with CAFs. These results suggest that CAFs were correlated with the differentiation of HNSCC cells in vitro.Conclusion: The number of CAFs was correlated with that of CSCs in HNSCC. HNSCC-derived CAFs can promote the differentiation of HNSCC cells in vitro.