This study was aimed to develop a novel qualitative multiplex polymerase chain reaction (PCR) for simultaneous detection of genetically modified (GM) soy and maize within a single reaction. The specific primers designed to detect four respective GM events (A2704-12, MON88017, Bt11, and MON863) were included in the tetraplex PCR system. Each of PCR products for four GM events could be distinguished by agarose gel based on their different lengths. The specificity and reproducibility of this multiplex PCR were evaluated. This multiplex PCR consistently amplified only a fragment corresponding to a specific inserted gene in each of the four GM events and also amplified all four of the PCR products in the simulated GM mixture. These results indicate that this multiplex PCR method could be an effective qualitative detection method for screening GM soy and maize in a single reaction.

Cellular imrnortali zation is thought to be an ear ly event during tumorigenesis. Telomerase reacLi vaLion by ecLopic hTERT expression is widely used for cellular imrnortali zation. This study was a imed Lo a na lyze establi sh immortalized human ora l epithelial cells(IOEC) and to reconstruct oral precancerous lesion by Lhree dimens iona l cultures. Telomerase activity was analyzed by Telomerase assays and Telomere longLh W:lS dcLccLcd by Termina l restri ction I"ragment analysis. bTERT gene was assayecl by tbe RT-PCR. p16lNK4 a‘ pHb. CDK2. P21CIP1. p27 and p53 were examined by western blotting. Three dimensiona l cu1ture using air - liquicl inLe rl"ace was pe rl"ormed. As results. IOEC was establi shed by ectopic ex pression of catalytic subunit• of telomerase‘ h1'EH1'. which is con tinuously maintained for more tban 120 population doublings(PDs) . IOEC showecl the expression 01" h1'ER1' and h1'H mHNA‘ elongated telomere length and higher telomerase activity. These cel ls showed no ex pression of p16lNK4a with retention 01" pRb and CDK2. Expression of p21CIP1. p27 a nd p53 may have no relation to immorta li ze oraJ epithelial cell s. Three dimensional culture of IOEC showed dysplastic strat ilïed epithelia l cell s. These results may serve as a useful moclel system for the study of oral carcinogenesis.