Abstract: Objective To observe the expression of phospholipase A2 (PLA2) in different human cancer xenograft models in nude mice. Methods Different human cancer xenograft models, including hepatocarcinoma, pancreatic cancer, gastric cancer, colon cancer, esophageal cancer, lung cancer, nasopharyngeal carcinoma, ovarian cancer, were established by tumor cell lines in nude mice. After the tumors grow to a volume of 1 cm³, the protein expression of four types of PLA2 enzymes in the tumor tissues, normal tissues, and serum were detected by ELISA, which in the serum of normal nude mice were tested as control. Results In the nude mice xenograft models of respiratory, digestive and reproductive system, the protein expressions of cPLA2, sPLA2 and lp-PLA2 in tumor tissues were significantly higher than those in normal tissues (P<0.05, P<0.01). Similarly, the protein expression of iPLA2 in tumor tissues was higher than that in normal tissues, except for human colorectal cancer cell line HT-29, which showed significant difference (P<0.01). Moreover, in the eight xenograft models, the protein content of four types of PLA2 in serum of tumor-bearing mice were obviously higher than those of normal nude mice (P<0.01). Conclusions Expression of four types of PLA2 in tumor tissues and serum were both up-regulated significantly in all the xenografted models, including respiratory cancer, digestive system cancer and reproductive system cancer, which did not limit to specific cancer type. The results inferred a key role for the PLA2 in the development of xenografted tumors in nude mice.

Key words: Nude mice, Xenografted models, Phosphlipase A2 (PLA2)