Expression and distribution of COX-2 in human gastric cancer cells / 中华消化杂志

ABSTRACT

Objective To detect the expression of cyclooxygenase(COX) in human gastric cancer cell lines and its subcellular location of the isoforms. Methods Immunohistochemistry、RTPCR combined with laser scanning cofocal microscopy (LSCM) were used to investigate expression and distribution of COX. Results Positive staining of COX2 and COX1 protein was seen in human gastric cancer cell line MKN45、SGC7901 and AGS. However, the COX2 staining was absent and COX1 staining was weak in MGC803; though their mRNA in all the four cell lines. When compared to COX1,COX2 showed a stronger signal at both protein and mRNA levels of the gastric cancer cell lines, which was confirmed by double labeling and LSCM. The quantitative analysis of fluorescein intensity indicated the pixel intensity peak of COX2 reached 50～70, while COX1 only 10. LSCM also showed that COX2 was both cytoplasmic and nuclear envelope staining but COX1 only in cytoplasm. Conclusions In human gastric cancer, there is stronger expression of COX2 than COX1, and different distribution of the two isoforms implies their distinct roles in cell function.