oblimersen and Kidney-Neoplasms

Oblimersen is an 18-base oligodeoxynucleotide encoding antisense to the gene for bcl-2, an anti-apoptotic protein that is upregulated in renal and other cancers. This study was designed to evaluate the combination of oblimersen with alpha-Interferon in advanced renal cancer. Trial endpoints were antitumor efficacy and toxicity, pharmacokinetics, and evidence of apoptosis in peripheral blood mononuclear cells.. Patients with measurable advanced renal cancer and 0-1 prior therapy were eligible. Treatment consisted of oblimersen, 7 mg/kg/day, as a continuous intravenous infusion 7 days of every 14 day cycle, plus alpha-IFN, 5 million units/m(2) subcutaneously, days 4 and 6 of the first oblimersen infusion, then thrice weekly. Blood for laboratory correlates was collected before treatment, during oblimersen, and during therapy with both agents.. Twenty-three patients were enrolled, five of whom had prior systemic therapy (three with prior high-dose interleukin-2). The median number of treatment cycles was 4 (range 1-12). One patient had a partial response lasting 2.5 months. The Grade 3-4 toxicities were fatigue, fever, myelosuppression, hepatic enzyme and metabolic abnormalities. Laboratory analyses of CD3+ lymphocyte apoptotic markers demonstrated no change between pre-treatment and on-treatment levels of bcl-2 or Annexin/PI positivity by flow cytometry. Mean oblimersen steady-state plasma concentration and clearance was 2.3 +/- 0.9 microg/ml and 0.15 +/- 0.07 l/h/kg, respectively.. Oblimersen given in this dose and schedule with alpha-IFN does not appear sufficiently active to warrant further study in advanced renal cancer. Combinations with newer targeted agents may show greater promise.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Female; Humans; Immunologic Factors; Interferon-alpha; Kidney Neoplasms; Male; Middle Aged; Thionucleotides

Oncological therapy strategies are increasingly concentrating on the causal, molecular changes involved in carcinogenesis. So called "smart drugs" such as antisense oligoneucleotide (AsON) can be used as specific inhibitors of individual genes. AsONs have shown their effectiveness in many studies. Clinical studies have demonstrated, however, that for many tumours the inhibition of a single gene is, due to multigenetic alteration, largely ineffective. The combination of AsONs with conventional chemotherapeutic agents is currently being investigated in phase III studies. In these studies, chemotherapeutic agents have been evaluated in cell culture together with AsON against the proliferation associated Ki-67 gene, as well as against the apoptosis associated bcl-2 gene via RT-PCR, immunochemistry and MTT cell viability assay. For both AsONs, significant target inhibition was achieved in cell culture with a high target gene expression. The prior treatment of tumour cells with bcl-2 AsON significantly increased the effectiveness of chemotherapy, while the combination of conventional chemotherapeutic agents with Ki-67 AsON showed no synergistic effects.

Topics: Animals; Antineoplastic Agents; Breast Neoplasms; Cell Division; Cell Line, Tumor; Cell Survival; Cisplatin; Colorimetry; Dose-Response Relationship, Drug; Drug Synergism; Humans; Ki-67 Antigen; Kidney Neoplasms; Mice; Oligonucleotides, Antisense; Proto-Oncogene Proteins c-bcl-2; Reverse Transcriptase Polymerase Chain Reaction; Thionucleotides; Tumor Cells, Cultured

Interferon alpha (IFNalpha) is used to treat patients with advanced renal cell carcinoma (RCC) despite limited clinical benefit. IFNalpha can induce Fas receptor-mediated apoptosis by direct activation of pro-caspase-8 followed by activation of caspase-3. Alternative, indirect activation of caspase-3 via mitochondrial release of cytochrome c can occur and may explain the rescue from Fas-activated cell death by the antiapoptotic members of the Bcl-2 family. In this study, we examined G3139, a novel antisense compound targeting Bcl-2, in combination with IFNalpha. Human RCC lines (SK-RC-44 and SK-RC-07) were treated with IFNalpha, G3139 or a combination of the two. Fas-mediated cytotoxicity was induced by anti-Fas mAb, CH11. An analysis of Bcl-2, Fas and the cleavage of PARP was performed. IFNalpha induced Fas and Bcl-2 in SK-RC-44 and SK-RC-07. IFNalpha sensitised SK-RC-44 to anti-Fas and induced PARP cleavage confirming that IFNalpha has a cytotoxic effect on RCC lines by induction of the Fas antigen. Cytotoxicity was not evident in SK-RC-07 cells treated with IFNalpha. G3139 induced a specific downregulation of Bcl-2 in SK-RC-07 cells, which were then sensitised to anti-Fas after treatment with IFNalpha. Taken together, these results suggest that Fas-dependent pathways as well as alternative pathways, which can be inhibited by Bcl-2, exist in renal cell carcinoma. G3139 in combination with IFNalpha is a potential therapy in patients with metastatic renal cell carcinoma.

Topics: Antineoplastic Agents; Apoptosis; Carcinoma, Renal Cell; Down-Regulation; fas Receptor; Humans; Interferon-alpha; Kidney Neoplasms; Oligonucleotides, Antisense; Proto-Oncogene Proteins c-bcl-2; Thionucleotides; Tumor Cells, Cultured