The retinoblastoma-interacting zinc-finger protein RIZ is a downstream effector of estrogen action.

Co-immunoprecipitation experiments in cell extract from cultured cells or target tissues indicated that estrogen receptor was complexed with the retinoblastoma binding protein RIZ in a ligand-dependent manner. Mapping of interaction sites indicated that in both proteins the same regions and motifs responsible for the interaction of transcriptional co-activator and nuclear receptors were involved. In cultured cells, estradiol induced a redistribution of RIZ protein within the nucleus and in the cytoplasm. A similar effect was produced in vivo, in prepuberal rat endometrium, by administration of a physiological dose of estradiol. Therefore, RIZ protein could be a specific effector of estrogen action downstream of the hormone-receptor interaction, presumably involved in proliferation control.

Serum interleukin-10 levels as a prognostic factor in advanced non-small cell lung cancer patients.

STUDY OBJECTIVE: To investigate the prognostic significance of interleukin (IL)-10 serum levels in advanced non-small cell lung cancer (NSCLC) patients. DESIGN: IL-10 serum levels were measured before chemotherapy, on completion of therapy, and at follow-up by means of a commercially available enzyme-linked immunoassay. The results were then analyzed in comparison with other prognostic variables, and a model predicting overall survival (OS) and time to treatment failure (TTF) was finally generated. SETTING: University hospital. PATIENTS: Sixty consecutive patients with TNM stage III or IV NSCLC undergoing conventional platinum-based regimens. RESULTS: Elevated levels of serum IL-10 were found in cancer patients with respect to healthy control subjects (17.7 +/- 4.4 vs 9.2 +/- 1.5 pg/mL, respectively; p < 0.05), with patients with metastatic disease showing significantly higher levels than patients with undisseminated cancer (21.0 +/- 4.2 vs 14.3 +/- 1.2 pg/mL, respectively; p < 0.05). Following completion of treatment, patients were classified as responders if they had achieved either one of the following: complete response, partial response, or stable disease; and nonresponders, in case of progressive disease. Retrospective analysis of basal IL-10 serum levels in these two subgroups showed a significant difference between responders and nonresponders (15.2 +/- 2.2 vs 21.4 +/- 4.2 pg/mL, respectively; p < 0.05). Moreover, a further significant increase in IL-10 serum levels was observed in nonresponders at the end of therapy (21.4 +/- 4.2 vs 26.0 +/- 4.3 pg/mL, prechemotherapy and postchemotherapy, respectively; p < 0.05), whereas values in responders were found to have significantly decreased (15.2 +/- 2.2 vs 14.8 +/- 2.2 pg/mL, prechemotherapy and postchemotherapy, respectively; p < 0.05). Using univariate and multivariate analyses, both OS and TTF were shown to be affected by the mean pathologic levels of IL-10. Stepwise regression analysis identified IL-10 serum level and stage as the prognostic factors related to OS, and IL-10 serum level and performance status as the prognostic factors related to TTF. CONCLUSIONS: In conclusion, this study shows that the measurement of pretreatment IL-10 serum levels is of independent prognostic utility in patients with NSCLC and may be useful for detection of disease progression.

Identification of a DNA binding protein cooperating with estrogen receptor as RIZ (retinoblastoma interacting zinc finger protein).

Double-stranded DNA fragments were selected from a random pool by repeated cycles of estrogen receptor-specific immunoprecipitation in the presence of a nuclear extract and PCR amplification (cyclic amplification and selection of target, CAST, for multiple elements). Fragments were cloned and sequence analysis indicated the 5-nucleotide word TTGGC was the most recurrent sequence unrelated to the known estrogen responsive element. Screening a HeLa cell expression library with a probe designed with multiple repeats of this sequence resulted in the identification of a 1700-aa protein showing a complete homology with the product of the human retinoblastoma-interacting zinc-finger gene RIZ. In transfection experiments, RIZ protein was able to bestow estrogen inducibility to a promoter containing an incomplete estrogen responsive element and a TTGGC motif. RIZ protein present in MCF-7 cell nuclear extract retarded the TTGGC-containing probe in an EMSA. Estrogen receptor was co-immunoprecipitated from MCF-7 cell extract by antibodies to RIZ protein and vice versa, thus indicating an existing interaction between these two proteins.

Amifostine: A selective cytoprotective agent of normal tissues from chemo-radiotherapy induced toxicity (Review).

Patients receiving systemic cancer chemotherapy must often have their dose intensity of therapeutic agents reduced, because a broad range of organs are adversely affected. Therefore, research and the development of agents protecting the normal tissues from the toxicity of antineoplastic therapy, without reducing the antitumour efficacy, are very important. Amifostine, a prodrug that forms an activated free thiol, when dephosphorylated by alkaline phosphatase, appears selective in its entry in non-malignant cells, and exerts a protective effect from toxicity induced by chemo- or radiotherapy on normal tissues, through free radical scavenging, hydrogen donation and inhibition of DNA damage. Studies in vitro and experimental models have confirmed the protective properties of amifostine in normal cells. In clinical trials pretreatment with amifostine reduced the frequency of cyclophosphamide induced neutropenia and nephro-, oto- and neurotoxicity of platinum compounds. In some cases the use of amifostine have also potentiated the effects of several drugs, such as alkylating agents and, in recent studies, taxanes. The main potentially dose-limiting adverse effect is hypotension, that is often asymptomatic. Amifostine is thus usefully employed in order to obtain a better quality of life in patients receiving oncologic treatments.

Soluble interleukin-2 receptor and soluble CD8 antigen levels in serum from patients with solid tumors.

High levels of soluble lymphocyte antigens have been described in a large number of tumors and, particularly, in hematopoietic neoplasms. As previously reported, many antitumor immune responses are IL-2 dependent: clinical observations indicate that a worse survival in advanced tumor patients is related with a decrease of soluble IL-2 levels. A soluble form of CD8 has been described: as found in Hodgkin's disease and acute lymphoblastic leukemia, sCD8 levels have a prognostic value. To explain the significance of these soluble molecules in solid tumors, we a) determinated sIL-2R and sCD8 in 84 patients; b) correlated the expression of p55 chain of IL-2R and CD8 antigen on the cell-surface of peripheral lymphocytes to sIL-2R and sCD8 levels; c) analyzed endogenous IL-2R levels in patients with lung cancer. An increase of sIL-2R was found in 82% of cases, while high levels of sCD8 were observed in 32%; no correlation was observed between sIL-2R and the expression of p55 on the surface of peripheral lymphocytes: IL-2 levels in patients with NSCLC were significatively reduced, when compared to healthy controls, with an inverse relationship between endogenous IL-2 concentration and sIL-2R levels. Whatever may be the physiopathological mechanism of the increase of sIL-2 observed in solid tumors, this rise may contribute to the immunodepression correlated to neoplastic disease. Therefore, higher levels of sIL-2R/IL-2 ratio has a negative biologic prognostic significance. We think that determinating CD8 antigen in the serum can offer a more sensitive and specific measurement of activation of suppressor/cytotoxic T-lymphocytes.

Interaction of vault particles with estrogen receptor in the MCF-7 breast cancer cell.

A 104-kD protein was coimmunoprecipitated with the estrogen receptor from the flowtrough of a phosphocellulose chromatography of MCF-7 cell nuclear extract. mAbs to this protein identified several cDNA clones coding for the human 104-kD major vault protein. Vaults are large ribonucleoprotein particles of unknown function present in all eukaryotic cells. They have a complex morphology, including several small molecules of RNA, but a single protein species, the major vault protein, accounts for >70% of their mass. Their shape is reminiscent of the nucleopore central plug, but no proteins of known function have been described to interact with them. Western blot analysis of vaults purified on sucrose gradient showed the presence of estrogen receptor co-migrating with the vault peak. The AER317 antibody to estrogen receptor coimmunoprecipitated the major vault protein and the vault RNA also in the 20,000 g supernatant fraction. Reconstitution experiments of estrogen receptor fragments with the major vault protein mapped the site of the interaction between amino acids 241 and 280 of human estrogen receptor, where the nuclear localization signal sequences are located. Estradiol treatment of cells increased the amount of major vault protein present in the nuclear extract and coimmunoprecipitated with estrogen receptor, whereas the anti-estrogen ICI182,780 had no effect. The hormone-dependent interaction of vaults with estrogen receptor was reproducible in vitro and was prevented by sodium molybdate. Antibodies to progesterone and glucocorticoid receptors were able to coimmunoprecipitate the major vault protein. The association of nuclear receptors with vaults could be related to their intracellular traffic.

Serum levels of interleukin-6 as a prognostic factor in advanced non-small cell lung cancer.

Serum levels of interleukin-6 (IL-6) were evaluated in a group of advanced non-small cell lung cancer (NSCLC) patients using an enzyme-linked immunosorbent assay. The data were related to clinical status and to cisplatin-based chemotherapy response. The mean IL-6 concentrations were higher than the controls (p<0.0001); patients with metastatic tumor had higher levels than those with undisseminated disease (p<0.006). Tumor progression was associated with an increase of IL-6 levels. Patients who responded to chemotherapy had lower serum IL-6 levels compared with unresponsive patients (p<0.0001). These data suggest that NSCLC patients with high levels of IL-6 have a worse clinical outcome and may manifest resistance to cisplatin chemotherapy.