Expression analysis of genes at 3q26-q27 involved in frequent amplification in squamous cell lung carcinoma

Gene amplifications are known to occur frequently in lung cancer. Recently, we identified gene amplifications at 3q26 in squamous cell lung carcinoma (SCC) using reverse chromosome painting. Here, our aim was to analyse the e xpression of genes which map within the amplified chromosomal region. The g enes which were selected for their known function and their potential invol vement in tumour development included the genes for ribosomal protein L22 ( RPL22), butyrylcholinesterase (BCHE), glucose transporter 2 (SLC2A2), trans ferrin receptor (TFRC), thrombopoietin (THPO) and the phosphatidylinositol- 3 kinase catalytic alpha polypeptide (PIK3CA). While five genes were expres sed in the majority of the 17 samples of SCC, the gene for the glucose tran sporter 2 (SLC2A2) was expressed in only three cases, excluding SLC2A2 as t he target gene of the amplification unit. For a subset of tumours, we deter mined the amplification status of the six genes. The TFRC, PIK3CA, BCHE, TH PO and SLC2A2 genes were amplified in several cases, whereas the RPL22 gene was amplified in only one case. The combined amplification and expression data of this and our previous studies indicate that the amplified region at 3q26 contains several genes that are transcribed in SCC, providing the pos sibility that several amplified and functionally important genes at 3q26 ma y be involved in the pathogenesis of SCC. (C) 1999 Elsevier Science Ltd. Al l rights reserved.