Exploration of Multigene, Multistep and Multipathway Models of Nasopharyngeal and Colorectal Carcinogenesis

OBJECTIVE To construct tree models for nasopharyngeal carcinoma (NPC) and colorectal carcinoma (CC) and explore the oncogeneic process of NPC and CC.

METHODS Based on the software that Desper et al. developed, tree models were constructed for CC from the comparative genomic hybridization (CGH) data of 118 CC patients and for NPC from the CGH data of 140 southern Chinese patients, respectively.

RESULTS T ree models for CC suggested that loss of 18q and gain of 20q were important early events in colorectal carcinogenesis. As changes in-18q occurred prior to those in -17p, a cause-effect relationship might exist between them. Tree models for NPC suggested that loss of 3p was an important early event in nasopharyngeal carcinogenesis, and deletion of 11 q. 14q. 16q and 9p were also nonrandom genetic events in carcinogenesis. suggesting that there might be tumor-associated genes existing on these chromosome arms. The tree model also Indicated the existence of oncogenes on the short arm of chromosome 12.

CONCLUSION Constructing tree models based on the CGH data to demonstrate the initiation and progression of NPC might help elucidate its multigene, multistep and multipathway development. It may provide valuable clues to explore the mechanism of tumorigenesis.