[Primary study of differentially expressed cDNA sequences in cell line HNE1 of human nasopharyngeal carcinoma by cDNA representational difference analysis].

OBJECTIVE

To search differentially expressed sequences correlated with pathogenesis of human nasopharyngeal carcinoma (NPC), including the candidates of tumor suppressor genes.

METHODS

cDNA representational difference analysis (RDA) was performed to isolate differentially expressed sequences between cDNA from normal human primary cultures of nasopharyngeal epithelial cells and cDNA from NPC cell line HNE1. The sources of differentially expressed products were proved by Southern blot and Northern blot. The fragments were cloned with pGEM-T easy kit and sequenced by the chain termination reaction.

RESULTS

Four differentially expressed cDNA fragments were isolated in the fourth subtractive hybridization using cDNA from normal human primary cultures of nasopharyngeal epithelial cells as tester amplicon and cDNA from NPC cell line HNE1 as driver amplicon by cDNA RDA. These differential cDNA fragments revealed that they really came from the tester amplicon and were not expressed or down-regulated in the NPC HNE1 cells. Of these obtained clones, some are the fragments of the human known genes including house-keeping genes, the others are novel genes.

CONCLUSION

NPC involves alteration of multiple genes. Some of known genes matched with the differentially expressed sequences have an effective suppressive ability on the carcinoma.