To research the expression levels of FEN1 and PCNA in carcinoma-associated fibroblasts (CAFs) and analyze their correlation.

Fresh specimens of oral squamous cell carcinoma tissues and normal oral mucosal tissues excised during oral and maxillofacial plastic surgery were collected. Primary oral CAFs and normal fibroblasts (NFs) were obtained by tissue culture, identified by immunocytochemistry and divided into the CAF and NF groups. Western blot and quantitative real-time PCR were used to detect the protein and mRNA expression levels of both FEN1 and PCNA in the oral CAFs and NFs. The correlation between FEN1 and PCNA expression in oral CAFs was analyzed.

Oral CAFs and oral NFs were successfully cultured and identified from 12 samples. Both the protein and mRNA expression levels of FEN1 and PCNA were higher in the oral CAFs than NFs, but there were no significant differences (P > 0.05). In the oral CAFs, the linear correlation coefficient between FEN1 and PCNA was 0.677 (P = 0.016) at the mRNA level, indicating a strong positive correlation; however, at the protein level, no correlation was found (P > 0.05).

In primary cultured oral CAFs and NFs, there were no significant differences in the FEN1 and PCNA protein and mRNA expression levels. However, in the CAFs, the mRNA levels of FEN1 and PCNA had a strong positive correlation. The relationship and the regulatory mechanism of the two genes require further study.