Expression of fibroblast activating protein in eyelid basal cell carcinoma associated fibroblasts

Abstract

AIM: To investigate the role and significance of carcinoma-associated fibroblasts(CAFs)in the occurrence and development of eyelid basal cell carcinoma(BCC), and study on the biological characteristics and the expression of fibroblast activation protein(FAP)of two kinds of fibroblasts associated with eyelid BCC and normal eyelid skin fibroblasts(normal fibroblasts, NFs).METHODS: CAFs and NFs were obtained by tissue primary cultured. The cell morphology of the 3rd generation purified cells were observed under an inverted phase contrast microscope and identified them using their biomarker by immunohistochemistry for CK, VIM, α-SMA and FAP. Cell growth and proliferation were measured by MTT assay. The expression of FAP mRNA and protein in cells was detected by RT-qPCR and Western Blot.RESULTS: The CAFs of the eyelid was long fusiform or spindle-shaped, with reduced cytoplasmic processes, more cytoplasmic granules, different cell sizes, disordered arrangement, overlapping growth, and loss of contact inhibition. NFs were in the form of extensive shuttle, radial arrangement, the cytoplasmic particles were rare, there was no overlapping growth phenomenon, and no contact inhibition. The proliferation rate of eyelid CAFs was faster than that of NFs. And the expression of FAP mRNA in CAFs was 3.672±0.221, which was significantly higher than that in NFs(1.034±0.024)(P<0.05). In addition, the expression level of FAP protein in CAFs was high, while NFs were not expressed(P< 0.05).CONCLUSION: There were significant differences in the biological characteristics of CAFs and NFs, such as morphological structure, growth and the proliferation, growth factor expression and so on. It was therefore suggested that the tumor microenvironment of eyelid basal cell carcinoma had changed, and further induced the biological characteristics and function of NFs, and finally transformed into CAFs. In addition, eyelid CAFs expressed higher expression of FAP than NFs, indicating that FAP may be involved in the occurrence and development of tumor cells in tumor microenvironment, which is associated with the invasive growth of CAFs in eyelid.

Keywords

• fibroblast activation protein
• eyelid basal cell carcinoma
• carcinoma-associated fibroblasts
• normal fibroblasts