Differentially expressed mRNAs in androgen-independent but not androgen-dependent Shionogi carcinoma

Recently, a new and highly effective method termed suppressive subtractive hybridization (SSH) has been introduced to clone differentially expressed m RNAs. Genes expressed in androgen-independent but not in androgen-dependent tumors, and vice versa, are obviously significant to delineate the mechani sms of androgen dependency/independency of these tumors. Mouse mammary canc er (Shionogi carcinoma-115) has been extensively used to analyze the mechan ism of androgen-dependent cancer growth. Methods: We cloned androgen-indepe ndent and androgen-dependent Shionogi carcinoma-115 specific mRNAs by the S SH method. Cloned sequences were compared with known sequences using NCBI B LAST across the Internet. Two clones were positive for cDNA insert when and rogen-independent cDNA was used as tester cDNA, while no clones were positi ve using the androgen-dependent tester cDNA. One of the former was mouse pr otein kinase C beta-II while the other was a new DNA sequence. Mouse protei n kinase C beta-II mRNA and the new mRNA were shown to be differentially ex pressed by RT-PCR analysis in androgen-independent but not androgen-depende nt Shionogi carcinoma. Two mRNA species differentially expressed in androge n-independent but not androgen-dependent Shionogi carcinoma were cloned by the SSH method. The significance of these mRNAs for androgen-dependency/ind ependency of Shionogi carcinoma should be explained in future studies.