RESUMO
Expression of the oncogenes, epidermal growth factor (EGF) receptor, HER2/neu, c-myc, and c-fos, in renal cell carcinoma and corresponding nonneoplastic kidney tissue of 30 patients has been analyzed by Northern blot analysis. In renal cell carcinoma an inverse relationship of EGF receptor and HER2/neu gene expression was detected, with high expression of the EGF receptor gene in 22 of 30 (73%) cases and low expression of the HER2/neu gene in 28 of 30 (93%) cases. Furthermore, altered expression of the oncogenes c-myc and c-fos was detected in renal cell carcinoma, which appears to be related to the tumor grade of malignancy. Additional Southern blot analysis of six renal cell carcinomas gave no indication of chromosomal rearrangement events or gene amplification.
Assuntos
Carcinoma de Células Renais/genética , Receptores ErbB/genética , Expressão Gênica , Neoplasias Renais/genética , Proteínas Proto-Oncogênicas/genética , Proto-Oncogenes , Biomarcadores Tumorais/análise , Northern Blotting , Southern Blotting , DNA de Neoplasias/genética , DNA de Neoplasias/isolamento & purificação , Humanos , Hibridização de Ácido Nucleico , Proteínas Tirosina Quinases/genética , Proteínas Proto-Oncogênicas c-fos , Proteínas Proto-Oncogênicas c-myc , RNA Neoplásico/genética , RNA Neoplásico/isolamento & purificação , Receptor ErbB-2RESUMO
The human Alpha glutathione S-transferase gene corresponding to the human liver cDNA clone pGTH2 was isolated from a cosmid genome library. The gene, represented by the clone cosGTH2, spans nearly 12 kb and contains seven exons. The intron/exon borders conform to the standard rules, and an open reading frame is present, starting at position 67 in exon 2, the double-stop codon being at position 733 in exon 7. Exons 1, 2 and 7 differ in length from the known rat gene coding for the Ya enzyme. A 209 bp 5'-upstream region contains TATA and CAT boxes and, in addition, motifs for Sp1-, NF1- and HNFI-binding factors. Clone cosGTH2 represents the less basic subunit, alpha y, of two Alpha glutathione S-transferase subunits (alpha x and alpha y) expressed in liver, which is identical with the kidney subunit alpha 2.
Assuntos
Clonagem Molecular , DNA/genética , Glutationa Transferase/genética , Sequência de Aminoácidos , Sequência de Bases , Southern Blotting , Cosmídeos , DNA/química , DNA/isolamento & purificação , Glutationa Transferase/química , Humanos , Dados de Sequência Molecular , Mapeamento por RestriçãoRESUMO
Using the polymerase chain reaction (PCR), a human kidney glutathione S-transferase (GST) alpha cDNA clone (GST alpha 12 K) was synthesized; it is identical to a known liver GST alpha cDNA clone except for one base change (G----A), indicating that an alpha class gene expressed in human kidney is similar to one expressed in human liver. Comparisons were made in the expression of GST alpha and GST pi between renal cell carcinoma and adjacent non-neoplastic tissue. Messenger RNA expression in 30 cases was determined by Northern blotting, and GST protein from nine of these cases was analyzed by HPLC. The GST alpha gene products were expressed at near-zero levels. The GST pi gene product was the predominant GST in tumors, but was decreased in absolute amount compared with control tissue, the tumor/control ratios for the GST pi gene obtained by Northern blots and HPLC analysis being 0.50 +/- 0.07 and 0.36 +/- 0.07 respectively. The resulting pattern in renal cell carcinoma therefore shows a predominance of GST pi. Since it is assumed that renal cell carcinoma derives from the proximal tubular epithelial cells which are high in GST alpha, this implies a dedifferentation in the GST expression pattern.