Primary cell cultures arising from normal kidney and renal cell carcinoma retain the proteomic profile of corresponding tissues.

Renal cell carcinoma (RCC) tissue is composed of a mixture of neoplastic and normal cells, which complicate proteome analysis. The aim of our study was to investigate whether it is feasible to establish primary cell cultures of RCC and of renal cortex maintaining the tissue phenotype along with a more homogeneous and enriched cytological material. Fourteen (82.3%) primary cultures from 17 surgical cases were established and characterized by morphology, growth rate, immunocytochemistry, and molecular analysis performed by Real-time PCR, Western blotting, two-dimensional electrophoresis (2-DE), and mass spectrometry. Cultures showed >90% cytokeratine-positive epithelial cells. In primary tumor cultures, the molecular phenotype of manganese superoxide dismutase and heat shock protein 27 was the same as that found in tumor tissues with overexpression and increased number of isoforms. Moreover, 27 out 28 specific proteins and their isoforms, present in spots excised from 2-DE gel of cortex or RCC cultures, corresponded to those identified on the 2-DE tissue cortex reference map, suggesting that these primary cultures retain the proteomic profile of the corresponding tissues.

N- and C-terminal isoforms of Arg quantified by real-time PCR are specifically expressed in human normal and neoplastic cells, in neoplastic cell lines, and in HL-60 cell differentiation.

The human ABL2 (or ARG) gene codes for a nonreceptor tyrosine kinase is involved in translocation with the ETV6 gene in human leukemia and has an altered expression in several human carcinomas. Two isoforms of Arg with different N-termini (1A and 1B) have been described. The C-terminal domain of Arg contains two F-actin-binding sequences that perform a number of actions related to cell morphology and motility by interacting with actin filaments. We have identified different-sized specific cDNAs in hematopoietic, epithelial, nervous, and fibroblastic cells by means of the reverse transcription (RT)-polymerase chain reaction (PCR) analysis of human Arg mRNA. Some of these cDNAs showed an adjunctive alternative splice event involving the 63 bp sequence of exon II, thus leading to four cDNA types with different N-termini: 1A long and short, and 1B long and short. Other cDNAs lacked a 309 bp sequence in the last exon involving one of the C-terminal F-actin binding domains, thus giving rise to two cDNA types: C-termini long and short. Quantified by real-time PCR-quantitative RT-PCR-these Arg transcript isoforms have specific expression patterns not only in different normal and tumor cell types, but also during cell differentiation and growth arrest. These isoforms maintained the open reading frames, and eight putative proteins were predicted. The different C-termini isoforms seem to retain the same quantitative reciprocal ratio of their respective transcripts. The Arg protein isoforms with different C-terminal actin-binding domains and different N-termini might have specific cellular localizations/concentrations, and differently regulated catalytic activity with different implications in normal and neoplastic cells.