Biomedical subjects

Ralph S Freedman

Publications and source records attributed to Ralph S Freedman.

24 records · Page 2Linked to original sources

PubMed2002

The expression of decorin in human ovarian tumors.

PURPOSE: The purpose of this study was to examine ovarian cancer cells for the expression of decorin, a proteoglycan component of the cell matrix that can inhibit cancer cell growth. EXPERIMENTAL DESIGN: Cultured ovarian cancer cells and surgically excised tumors were examined by immunohistochemistry and Western blot analysis for decorin expression. Reverse transcription-polymerase chain reaction analysis was used to analyze cultured cells for decorin transcripts. RESULTS: We detected decorin transcripts in two ovarian cancer cell lines by reverse transcription-polymerase chain reaction analysis. However, no decorin was found in conditioned culture medium from those cell lines. Cells treated with the proteasome inhibitor MG132 showed strong perinuclear staining with a decorin-specific monoclonal antibody by immunohistochemistry. Also, Western blot analysis showed the presence of a ladder of decorin-specific bands that were intensified by treatment with MG132, suggesting that de novo synthesized decorin was degraded by the ubiquitination pathway. The decorin component of tumor stroma was previously shown to contain high levels of chondroitin sulfate as opposed to dermatan sulfate side chains, and those molecules contained unusually high levels of O- and 6-sulfate linkages. We provided immunohistochemical evidence that these chondroitin sulfate side chains may have been produced by myofibroblasts. CONCLUSIONS: Decorin protein expression was not detected in ovarian cancer cells. Decorin transcripts were produced and probably translated, but the protein was probably degraded by the ubiquitination pathway. We present evidence that stromal decorin of ovarian tumors was made by myofibroblasts. We also propose that decorin may be a tumor suppressor gene that is inactivated during epithelial cell development.

Actins↗

PubMed2002

Phase I study of intraperitoneal recombinant human interleukin 12 in patients with Müllerian carcinoma, gastrointestinal primary malignancies, and mesothelioma.

PURPOSE: The purpose is to determine dose-limiting toxicity, pharmacokinetics,pharmacodynamics, and immunobiology after i.p. injections of recombinant human IL-12 (rhIL-12). EXPERIMENTAL DESIGN: rhIL-12 was administered to 29 previously treated patients with peritoneal carcinomatosis from Müllerian carcinomas, gastrointestinal tract carcinomas and peritoneal mesothelioma in a Phase I trial. rhIL-12 doses were increased from 3 to 600 ng/kg. Three or more patients at each level received weekly i.p. injections of rhIL-12. RESULTS: Dose-limiting toxicity (elevated transaminase) occurred in 2 of 4 patients at the 600 ng/kg dose. More frequent toxicities included fever, fatigue, abdominal pain, nausea, and catheter-related infections. Ten patients received 300 ng/kg with acceptable frequency and severity of side effects. Two patients (one with ovarian cancer and one with mesothelioma) had no remaining disease at laparoscopy. Eight patients had stable disease and 19 progressive disease. At 300 ng/kg i.p., IL-12 was cleared from peritoneal fluid in a biphasic manner with a terminal-phase half-life of 18.7 h; peritoneal fluid levels of IL-12 5 min after i.p. injection were 100-200 pg/ml, and serum levels reached approximately 10 pg/ml between 24 and 36 h. IL-1-alpha, IL-2, IL-10, tumor necrosis factor alpha, and IFN-gamma were determined in serum and peritoneal fluid. IFN-gamma, IL-10, and tumor necrosis factor alpha were detected most frequently. Immunobiological effects included peritoneal tumor cell apoptosis, decreased tumor cell expression of basic fibroblast growth factor and vascular endothelial growth factor, elevated IFN-gamma and IFN-inducible protein 10 transcripts in peritoneal exudate cells, and increased proportions of peritoneal CD3(+) relative to CD14(+) cells. CONCLUSIONS: rhIL-12 at 300 ng/kg by weekly i.p. injection is biologically active and adequately tolerated for Phase II studies.

Adenocarcinoma↗

PubMedDate not supplied

The immunotherapy of patients with ovarian cancer.

Ovarian cancer is a leading cause of cancer mortality. Chemotherapy is effective in reducing tumor burden in a majority of patients, however, only approximately 20% of advanced disease patients will ultimately survive tumor free, and further treatment options are needed. Continuing advances in immunology make immunotherapy a promising area for future research. The design of immunotherapy strategies for ovarian cancer requires an understanding of the immune microenvironment of the peritoneal cavity, which is frequently involved with ovarian cancer metastases and is the site of its most devastating effects. Immunotherapy approaches for ovarian cancer include locoregional and systemic cytokine therapies, prophylactic and therapeutic vaccines, and adoptive immunotherapy strategies. This review will summarize previous clinical trials as well as future directions for research. Further progress in T-cell specific immune responses will require the identification of specific ovarian cancer antigens that are processed and presented on the surface of tumor cells in the context of specific HLA molecules. In addition, a more detailed understanding of functional relations between the peritoneal microenvironment and the metastatic process is required.

Female↗

PubMedDate not supplied

Intraperitoneal fluid neopterin, nitrate, and tryptophan after regional administration of interleukin-12.

Activated monocytes-macrophages may be associated with antitumor activity, and activation of these cells by certain cytokines, primarily interferon gamma (IFN-gamma), can be indicated by alterations in the concentrations of neopterin, nitrate, or tryptophan. Specimens of peritoneal fluid were obtained from patients with intra-abdominal neoplasia who were undergoing treatment in a phase I trial of weekly intraperitoneal recombinant interleukin-12 (rhIL-12), an inducer of IFN-gamma. Concentrations of neopterin, nitrate, tryptophan, IFN-gamma, and tumor necrosis factor alpha (TNF-alpha) were determined at various times during the first 48 hours in 11 patients who received intraperitoneal rhIL-12 in doses ranging from 100 to 1,500 ng/kg. An increase in peritoneal fluid nitrate concentrations was observed in nine of these patients. Increased concentrations of TNF-alpha and IFN-gamma were detected in 3 of 9 and 8 of 11 patients, respectively. Increased peritoneal fluid neopterin concentrations were detected by 24 hours after the injection in all patients studied. A significant increase in the ascitic fluid neopterin level could still be detected after 1 or 2 weeks of treatment (mean +/- standard error, 7.8 +/- 1.5 nM vs. 4.6 +/- 0.3 nM; Wilcoxon test, p = 0.0019), which is consistent with monocyte-macrophage activation. In contrast, the tryptophan concentration was lower (4.7 +/- 1.1 microM vs. 6.1 +/- 1.2 microM; p = 0.0428) after 1 or 2 weeks of treatment. There was a significant correlation between the dose of rhIL-12 and posttreatment neopterin concentrations (r(s) = 0.559, p = 0.0102). The intraperitoneal delivery of rhIL-12 appears to be associated with an immediate, sustained, and dose-dependent increase in peritoneal fluid neopterin, associated in most patients by an increase in IFN-gamma and in certain patients by an increase in nitrate and a decrease in tryptophan concentrations.

Abdominal Neoplasms↗

PubMedDate not supplied

Increased expression of heat shock protein 70 in adherent ovarian cancer and mesothelioma following treatment with manumycin, a farnesyl transferase inhibitor.

Since farnesylation by farnesyltransferase (FTase) is the first obligatory step in the signaling transduction pathway of ras p21, FTase has been the target of new anticancer treatment modalities. Famesyl transferase inhibitors (FTIs), a novel class of antitumor drugs that blocks the oncogenic activity of ras, were first developed as therapy for ras-mutated human tumors. FTIs are also capable of inhibiting tumors without ras mutations, while different mechanisms of cell growth inhibition by FTI have been proposed. In cell culture and in animal models, FTIs have been shown to be potent inhibitors of cancer cell growth. We showed that manumycin, a farnesyl pyrophosphate competitive inhibitor, inhibits ovarian and mesothelioma cancer cell growth. To examine the molecular changes after exposure to manumycin, total proteins from treated and untreated 2774 cell line were extracted and separated by two dimensional gel electrophoresis (2-DE) and detected by colloidal coomassie blue staining. The 2-DE was found reliable for comparison of protein profiles before and after manumycin treatment. Two protein spots (spot 1 and 2) appeared after manumycin treatment. Generated peptide peaks were matched by database query (prowl.rockefeller.edu/cgi-bin/ProFound) to a heat shock protein (HSP) and a modified HSP, both with MW 70 KD. The expression status of HSP 70 was confirmed by Western blot and HSP 70 ELISA using an antibody against HSP 70. The expression of HSP70 increased with the length of exposure to, and the dose of manumycin as demonstrated by ELISA. Increase in HSP70 expression was also observed by Western blot after a 48-hour treatment with manumycin in ovarian cancer cell line OVCAR3 and three other cell cultures derived from samples of patients diagnosed with ovarian cancer and mesothelioma. Our study is the first report demonstrating an up-regulation of HSP 70 in ovarian cancer cell lines and mesothelioma cell cultures after treatment with the FTI, manumycin. This up-regulation of HSP 70 may be a cellular mechanism of cell self-protection against the apoptotic process and cell death, and it may enhance resistance and account for the altered sensitivity of certain cancers to FTIs agents. HSPs may therefore be an important molecular target for drug intervention strategies.

Alkyl and Aryl Transferases↗

PubMedDate not supplied

Immune responses to human tumors: development of tumor vaccines.

Strong evidence has been accumulated demonstrating that tumor cells in humans and animal are recognized in general as non-self by the immune system and they are able to induce an immune response which often leads to their elimination. In humans, this evidence includes: (a) The development of T-cell lines and clones with antitumor activity (cytotoxic or helper) which is restricted to autologous tumor cells or to cells expressing the same tumor peptide/HLA epitope; (b) the presence of oligoclonal T cells infiltrating many tumors; (c) the identification and molecular cloning of tumor antigens and of peptides derived from these antigens, which elicit HLA-restricted immune responses. Their discovery provided the ultimate proof for the presence of specific immune responses in human tumors. The availability for the first time of molecularly cloned tumor antigens permitted the development of peptide or recombinant tumor vaccines. Although significant progress has been made and tumor peptide vaccines capable of eliciting biological responses in more than 50% of the patients and objective clinical responses in 10 to 42% of the patients have been reported, certain major problems remain and need to be resolved in order to develop effective tumor vaccines. These problems emanate from the following mechanisms that the tumor cells are employing to avoid detection and destruction by the immune system: (i) Down-regulation of HLA class I expression on the surface of tumor cells; (ii) Down-regulation of tumor antigen expression or selection of negative tumor variants; (iii) Expression of naturally occurring altered peptide ligands by tumor cells; (iv) Lack of costimulatory molecules on tumors cells; (v) Production of immunosuppressive cytokines, such as TGF-beta and IL-10; (vi) Induction of lymphocyte apoptosis by tumor cells using the Fas/Fas L pathway; (vii) Down-regulation or absence of CD3 zeta (zeta) transcripts or protein in tumor-infiltrating lymphocytes (TIL), and others. The selection of optimal tumor antigens for vaccine development is another issue that requires attention. Lineage specific or differentiation antigens appear to be better candidates for the development of tumor vaccines because they are expressed in all tumor cells. Methods for antigen presentation, such as those using dendritic cells, also play a critical role in the development of tumor vaccines. In addition to the progress towards the development of tumor vaccines, substantial progress has been made in developing advanced methods of adoptive immunotherapy based on TIL. This approach can be effective when an immune response can not be elicited in vivo. The progress made towards the development of tumor vaccines and approaches for adoptive immunotherapy has been substantial. Additional studies need to be carried out to develop new and effective tumor vaccines and adoptive immunotherapy methods.

Animals↗