SIGNAL-TRANSDUCTION ABNORMALITIES IN T-LYMPHOCYTES FROM PATIENTS WITHADVANCED RENAL-CARCINOMA - CLINICAL RELEVANCE AND EFFECTS OF CYTOKINETHERAPY

Studies have demonstrated abnormalities of the CD3/T-cell antigen rece ptor (TCR) and pathways of signal transduction in T lymphocytes from a nimals and patients with advanced malignancy. Diminished expression of TCR zeta and p56(lck) that are associated with the TCR and reduced nu clear localization of RelA containing nuclear factor kappa B (NF kappa B) complexes have been noted. These defects have been described in T cells from patients with malignant melanoma, renal cell carcinoma (RCC ), ovarian cancer, and colorectal cancer. Preliminary observations als o indicate possible correlation with clinical variables such as stage in selected instances. To further characterize altered expression of T CR zeta, p56(lck), and impaired activation of NF kappa B, T lymphocyte s were obtained from 65 patients with RCC, the majority of whom were r eceiving combination cytokine therapy [interleukin (IL)-2, IFN alpha-c ontaining regimens] and 37 control individuals. In 29 of these patient s, levels of TCR zeta and p56(lck) were determined by Western blots of T-cell lysates and semiquantitated using densitometry. Relative level s were then correlated with a series of clinical variables including r esponse to therapy, performance status, survival, disease sites, age, and others. In another group of 28 patients (three individuals from th e first group), the frequency of abnormal NF kappa B activation was st udied using electrophoretic mobility shift assays after activation of T cells with phorbol myristate acetate/ionomycin or anti-CD3 monoclona l antibody. Changes in these signaling molecules during cytokine treat ment were also investigated. TCR zeta and p56(lck) were detected in th e peripheral blood T cells in 27 of 29 patients, and overall, reduced levels were noted visually in 12 of 29 (41%) and 13 of 29 (45%) indivi duals, respectively. When levels were semiquantitated using densitomet ry, significant decreases of TCR zeta (P = 0.029) and p56(lck) (P = 0. 029) but not CD3 epsilon (P = 0.131), compared with control levels, we re found. In patients treated with IL-2/IFN alpha-based therapy, relat ive levels of TCR zeta increased significantly (P = 0.002) on day 15 o f cycle one compared with the baseline. Correlations of TCR zeta or p5 6(lck) levels with response or disease variables, except for lower TCR zeta levels (P < 0.001) in the presence of bone metastases, were not found. Abnormal NF kappa B activation after stimulation with phorbol m yristate acetate/ionomycin and/or anti-CD3 monoclonal antibody was fou nd in 59% of patients (17 of 28) and was not accounted for by the adva nced age of the study cohort. Activation of NF kappa B in peripheral b lood T cells was inducible during cytokine therapy in four of six indi viduals who displayed impaired NF kappa B activity prior to therapy. M oreover, impaired activation of NF kappa B does not appear linked to a reduction of TCR zeta expression, because in five patients, normal TC R zeta levels were present although kappa B binding was not inducible. In the majority of patients with advanced RCC, peripheral blood T cel ls express TCR zeta and p56(lck), and in a subset, reduced levels of t hese TCR zeta associated molecules are seen that may increase during c ytokine-based therapy, Abnormal activation of NF kappa B is also prese nt in >50% of patients and may also revert to normal during IL-2/IFN a lpha-based treatment. This alteration in NF kappa B activation occurre d in the presence of normal expression of TCR zeta-associated signalin g elements. The clinical significance of these findings remains unclea r.