Objective: To investigate methodology of cloning full-length cDNA from tissues of normal adrenal gland and pheochromocytoma and predict their function.
Methods: 104 samples from normal adrenal gland and 22 samples from pheochromocytoma were examined by expressed sequence tags (EST) sequencing, bioinformatics analysis, in silico cloning, rapid amplification of cDNA ends and RT-PCR.
Results: Among the 126 samples of novel full-length cDNA cloning 104 were from normal adrenal gland, and 22 from pheochromocytoma (PC). Among the novel genes 50 were cloned by direct sequencing of clones, 74 by in silico cloning, and 2 by rapid amplification of cDNA ends, and the localization of chromosomes was made with UniGene searching and radiation hybrid (RH) procedure. Comparison of homology and analysis of motif or domain showed that some genes may be important functional genes, such as those coding signaling proteins, proteins associated with ion channel, enzymes involved in hormone production, important transcription factors, translation initiation factors, etc. 7 of the novel full-length cDNAs are new isoforms produced by alternative splicing.
Conclusion: 126 novel full-length cDNAs have been cloned from adrenal tissues by large-scale EST sequencing and bioinformatic tools in a rather short time, some of which may play an important role in regulating adrenal functions and tumorigenesis of adrenal gland.