To determine whether G250 antigen (MN/CA IX/G250) could be a potential therapeutic target and a tumour marker, a total of 147 cases of RCC were investigated immunohistochemically as well as by reverse transcriptase polymerase chain reaction (RT-PCR) analysis.
Generalized up-regulation of CA IX in VHL-associated renal cell carcinoma contrasted with focal perinecrotic expression in a variety of non-VHL-associated tumors.
Altogether, our data showed that endocytosis of G250 TAA should be the basis of gene transfer to RCC, suggesting that targeting of TAA capable of internalization may be the basis of new approaches for designing alternative cancer gene therapy procedures.
In view of the induction/up-regulation of G250 antigen in RCC, its restricted tissue expression and its possible role in therapy, we set out to molecularly define the G250 antigen, which we identified as a transmembrane protein identical to the tumor-associated antigen MN/CAIX.
Here we describe a novel RCC vaccine strategy that allows for the concomitant delivery of dual immune activators: G250, a widely expressed RCC associated antigen; and granulocyte/macrophage-colony stimulating factor (GM-CSF), an immunomodulatory factor for antigen-presenting cells.
Here we describe the conditions for activation, gene transduction, and proliferation for primary human T lymphocytes to yield: (a) optimal functional expression of the transgene; (b) ch-Rec-mediated cytokine production, and (c) cytolysis of G250-TAA(POS) RCC by the T-lymphocyte transductants.
Furthermore, a primary culture of RCC tissue revealed increasing hypomethylation of the G250 gene in successive passages, suggesting that the G250 hypomethylation observed in vitro is tissue culture induced.
Previous studies relating to G250 protein or G250 mRNA expression in RCC using human tissue have largely been limited to immunohistochemical or conventional RT-PCR approaches that lack reproducibility, are subject to observer bias and are at most semi-quantitative.
When applied to blood samples from three RCC patients treated with intravenous infusions of scFv(G250)(1) T cells, the kinetics of scFv(G250)(1) T cell counts as detected by flow cytometry were similar to those detected by real-time PCR, although PCR allowed detection of transduced T cells over a longer period of time (i.e., for patient 3, 7 versus 32 days, respectively).
CAIX expression seems to be an important predictor of outcome in renal cell carcinoma patients receiving IL-2-based therapy and may enhance prognostic information obtained from pathology specimens.
We studied this concept in patients with metastatic renal cell cancer (RCC) using retroviral transduction of T cells with a single-chain Ab-G250 chimeric receptor [scFv(G250)].
Other genes involved in regulating hypoxia-inducible factor [e.g. genes encoding carbonic anhydrase-IX and PTEN (phosphatase and tensin homolog)] were reported to be prognostically important in renal cell carcinoma.
CA9 rs12553173 and CAIX are independent prognostic factors of overall survival and complementary for predicting the prognosis of metastatic clear cell renal cell carcinoma.
HIF-1α, HIF-2α and CAIX were up-regulated in 88.2% (15/17), 100% (17/17) and 88.2% (15/17) of tumors respectively and their expression is independent of VHL status. hnRNP A2/B1 and osteopontin expression was variable in CCRCCs and had no association with VHL genetic status.