[Functions of neutrophil gelatinase-associated lipocalin in the esophageal carcinoma cell line SHEEC].

Neutrophil gelatinase-associated lipocalin (NGAL) is a novel member of the lipocalin family and may be a new human oncogene product, but function of NGAL is not clear in the cancer. It was recently found that NGAL was overexpressed in the progression of malignant transformation from human immortalized esophageal epithelial cell line SHEE to esophageal carcinoma cell line SHEEC. This indicated that cell line SHEEC was a good model for exploring functions of NGAL in the carcinogenesis. The effects of blocking transcription of NGAL gene on invasion, division and proliferation of SHEEC cells were studied by antisense blocking RNA technique and tumor formation in nude mice. The results showed that the antisense blocking of transcription of NGAL gene not only decreased effectively the activity of MMP-9 and MMP-2 secreted by SHEEC cells, but suppressed significantly also the invasion of these cells in nude mice. However, the telomere length, the content of the cellular topoisomerase II-alpha and cellular proliferation index (PI) of the SHEEC cells have not been changed markedly. These results indicate that NGAL is possibly involved in invasion of tumor cells by regulating activity of MMP-9 and MMP-2, but is not apparently related with division and proliferation of tumor cells in SHEEC.