brivudine and Adenocarcinoma

Several reports describe the importance of the chaperone HSP27 (HSPB1) in cancer progression, and the demand for drugs that modulate HSPB1-activity is increasing rapidly. We reported earlier that RP101 (Bromovinyldeoxyuridine, BVDU, Brivudine) improves the efficacy of chemotherapy in pancreatic cancer.. Chemistry: Binding of RP101 and HSPB1 was discovered by affinity chromatography. Molecular and cell biology: HSPB1 in vitro transcription/translation (TNT), Pull down using RP101-coupled magnetic beads, Immuno Co-precipitations, Structural modeling of HSP27 (HSPB1), Introduction of point mutations into linear expression templates by PCR, Heat shock, Tumor Invasion. Animal experiments: Treatment of AH13r Sarcomas in SD-rats. Clinical Studies with late-stage pancreatic cancer patients: Pilot study, Dose finding study, Phase II study (NCT00550004).. Here, we report that RP101 binds in vitro to the heat shock protein HSPB1 and inhibits interaction with its binding partners. As a result, more activated CASP9 was detected in RP101-treated cancer cells. We modeled HSPB1-structure and identified the RP101 binding site. When we tested RP101 as an anti-cancer drug in a rat model, we found that it improved chemotherapy. In clinical studies with late-stage pancreatic cancer patients, the dose of 500 mg/day was safe and efficient, but 760 mg/day turned out to be too high for lightweight patients.. The development of RP101 as a cancer drug represents a truly novel approach for prevention of chemoresistance and enhancement of chemosensitivity.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Bromodeoxyuridine; Disease Models, Animal; Dose-Response Relationship, Drug; Double-Blind Method; Drug Evaluation, Preclinical; Female; Heat-Shock Proteins; HSP27 Heat-Shock Proteins; Humans; Male; Middle Aged; Models, Molecular; Molecular Chaperones; Pancreatic Neoplasms; Pilot Projects; Placebos; Rats; Rats, Sprague-Dawley; Sarcoma; Survival Analysis

Metabolic suicide gene transfer is widely applied for gene therapy of cancer, and retroviral vectors expressing the herpes simplex virus thymidine kinase (HSV-tk) gene are commonly used in clinical trials. Most of these vectors contain positive selectable markers that undoubtedly facilitate the determination of viral titer and the identification of high-titer producer clones. However, the presence of additional transcriptional units may result in reduced expression of the gene of interest. The use of fusion genes expressing bifunctional proteins may help to overcome this problem. We have constructed a retroviral vector carrying the TNFUS69 chimeric gene, which originates from the fusion of the HSV-tk and neomycin phosphotransferase II genes, and evaluated the functional expression of the encoded fusion protein. In vitro, expression of the fusion gene conferred to target cells both resistance to neomycin and selective sensitivity to the antiherpetic drugs ganciclovir and (E)-5-(2-bromovinyl)-2'-deoxyuridine. Cells transduced with the fusion gene, however, showed reduced ability to phosphorylate ganciclovir compared with cells expressing the native HSV-tk. Therefore, although the fusion gene may be used as a constituent of retroviral cassettes for positive and negative selection in vitro, its usefulness for suicide gene transfer applications in vivo may depend upon the possibility of using (E)-5-(2-bromovinyl)-2'-deoxyuridine in a clinical context.

Topics: 3T3 Cells; Adenocarcinoma; Animals; Antiviral Agents; Bromodeoxyuridine; Colonic Neoplasms; Fibrosarcoma; Ganciclovir; Genetic Vectors; Kanamycin Kinase; Mice; Mice, Inbred C57BL; Phosphorylation; Plasmids; Recombinant Fusion Proteins; Retroviridae; Simplexvirus; Thymidine Kinase; Transcription, Genetic; Transfection; Tumor Cells, Cultured

Nucleoside kinases from several species are investigated as "suicide genes" for treatment of malignant tumors by combined gene/chemotherapy. We have recently cloned a multisubstrate deoxyribonucleoside kinase of Drosophila melanogaster (Dm-dNK), and we have shown that the enzyme phosphorylates cytotoxic pyrimidine and purine nucleoside analogs. The broad substrate specificity of the enzyme, as well as its very high catalytic rate, makes it a unique member of the nucleoside kinase enzyme family. In the present study, we evaluated Dm-dNK as a suicide gene by constructing a replication-deficient retroviral vector that expresses the enzyme. The human pancreatic adenocarcinoma cell line MIA PaCa-2 and a thymidine kinase-deficient osteosarcoma cell line were transduced with the recombinant virus. We showed that Dm-dNK can be expressed in human cells, that the enzyme retained its enzymatic activity, and that it is localized in the cell nuclei due to a nuclear localization signal in its C-terminal region. The cells expressing Dm-dNK exhibited increased sensitivity to several cytotoxic nucleoside analogs, such as 1-beta-d-arabinofuranosylcytosine, 1-beta-d-arabinofuranosylthymine, (E)-5-(2-bromovinyl)-2'-deoxyuridine, 2-chloro-2'-deoxyadenosine, and 2',2'-difluorodeoxycytidine. These findings suggest that Dm-dNK may be used as a suicide gene in combined gene/chemotherapy of cancer.

Topics: Adenocarcinoma; Animals; Antimetabolites, Antineoplastic; Antineoplastic Agents; Antiviral Agents; Arabinonucleosides; Bromodeoxyuridine; Catalysis; Cell Division; Cell Nucleus; Cladribine; Cytarabine; Deoxycytidine; Drosophila melanogaster; Gemcitabine; Humans; Inhibitory Concentration 50; Kinetics; Osteosarcoma; Pancreatic Neoplasms; Phosphorylation; Phosphotransferases (Alcohol Group Acceptor); Promoter Regions, Genetic; Retroviridae; Substrate Specificity; Thymidine; Thymidine Kinase; Transduction, Genetic; Tumor Cells, Cultured

We developed a rapid and simple method for the screening of antiviral agents against herpes simplex virus (HSV) in a model of gastrointestinal herpetic infection in vitro. This method was based on inhibition of HSV-induced cytopathogenicity in gastric adenocarcinoma MKN-28 cells, as monitored by an MTT colorimetric assay. From the various compounds that were evaluated for their activity against HSV-1 and HSV-2, brivudine (BVDU) emerged as the most effective. When the 50% effective concentration (EC50) values of the antiherpes agents in MKN-28 cells were compared with those in human embryo lung MRC-5 cells, all compounds, except for BVDU, showed higher EC50 values in MKN-28 cells. For BVDU the EC50 values in MKN-28 cells were 0.8 (HSV-1) and 0.036 (HSV-2) times the EC50 values in MRC-5 cells. Thus BVDU was 27.5 times more active against HSV-2 in MKN-28 cells than in MRC-5 cells. The MKN-28 gastric cancer cells may be useful for the rapid screening of anti-HSV agents and, in particular, those that may be useful in therapy of gastrointestinal HSV infections in gastrointestinal herpetic infection.

Topics: Adenocarcinoma; Antiviral Agents; Bromodeoxyuridine; Colorimetry; Coloring Agents; Drug Evaluation, Preclinical; Herpesvirus 1, Human; Herpesvirus 2, Human; Humans; Stomach Neoplasms; Tetrazolium Salts; Thiazoles; Tumor Cells, Cultured; Virus Replication

The antitumor activity of 5'-deoxy-5-fluorouridine (DFUR), a prodrug of 5-fluorouracil (5-FU), is markedly enhanced if DFUR treatment is combined with (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU). Combined oral administration of DFUR (10 mg/kg) and BVDU (10 mg/kg) three times (every 3 h) per day for 5 days afforded greater antitumor activity than a single dose of DFUR (300 mg/kg/day) for 5 days in mice bearing either adenocarcinoma 755 or Lewis lung carcinoma, while in the colon 26 system the antitumor effects of both treatment regimens were equivalent. Thus, a low-dose regimen of DFUR when combined with BVDU provides a similar or greater antitumor activity than a high-dose regimen of DFUR that is not combined with BVDU. The area under the curve of plasma 5-FU following a treatment with the combination of DFUR (10 mg/kg) and BVDU (10 mg/kg) was equal to that following DFUR (300 mg/kg) treatment.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Antiviral Agents; Bromodeoxyuridine; Colonic Neoplasms; Drug Therapy, Combination; Floxuridine; Fluorouracil; Liver Neoplasms; Lung Neoplasms; Mice; Mice, Inbred BALB C; Pentosyltransferases; Prodrugs; Pyrimidine Phosphorylases

5'-Deoxy-5-fluorouridine (DFUR), whether or not combined with (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) was pursued in BDF1 mice from both a pharmacokinetic viewpoint, following a single oral dose administration, and an anticancer viewpoint, following 5 daily oral doses in mice inoculated subcutaneously with adenocarcinoma 755 tumor cells. Half-life (t1/2) values for the elimination of DFUR and 5-fluorouracil (5-FU) from plasma following DFUR (100 mg/kg) administration were about 0.80 and 0.39 hr, respectively. Plasma 5-FU AUC (area under the curve) values following oral DFUR (100 mg/kg) was 0.224 micrograms.hr/ml. If DFUR (100 mg/kg) was combined with BVDU (10 mg/kg) the t1/2 and AUC values for 5-FU increased from 0.39 to 1.24 hr, and from 0.224 to 1.699 micrograms.hr/ml, respectively. Thus, BVDU significantly increased the plasma levels of 5-FU. It had no effect on the plasma levels of DFUR. At 100 mg/kg, DFUR did not show a significant antitumor activity. At 500 mg/kg it effected a 90% inhibition in tumor growth. When combined with BVDU (10 mg/kg), DFUR at 100, 200 and 300 mg/kg reduced tumor growth by 96, 100 and 100%, respectively. The antitumor activity achieved by DFUR, in the presence or absence of BVDU, correlated highly significantly with the AUC values for plasma 5-FU.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Bromodeoxyuridine; Chromatography, High Pressure Liquid; Drug Synergism; Floxuridine; Fluorouracil; Half-Life; Male; Mice; Neoplasm Transplantation; Spectrophotometry, Ultraviolet

A marked inhibition of the growth of solid tumor adenocarcinoma 755 was achieved by the combination of 5-fluorouracil (5-FU) with bromovinyldeoxyuridine (BVDU). The therapeutic index (LD50/ED50) for the combination of BVDU plus 5-FU was 8.1 and 3.9 upon intraperitoneal (i.p.) or oral (p.o.) administration, respectively. The therapeutic index of i.p. 5-FU given alone was 2.3, whereas for p.o. 5-FU given alone no therapeutic index could be established because of insufficient activity of the compound. Thus, the therapeutic index of 5-FU increased significantly when combined with BVDU. Pharmacokinetic studies revealed that upon i.p. or p.o. 5-FU administration plasma 5-FU levels rapidly declined, but that, in the combination with BVDU, the plasma clearance of 5-FU, especially following p.o. administration, was slowed down considerably. Antitumor activity of 5-FU correlated with AUC (area under the concentration x time curve), within the plasma 5-FU concentration range from 0.02 to 0.4 microgram/ml.

Topics: Adenocarcinoma; Animals; Antineoplastic Combined Chemotherapy Protocols; Bromodeoxyuridine; Chromatography, High Pressure Liquid; Drug Synergism; Fluorouracil; Male; Mice

A significant inhibition of the growth of adenocarcinoma 755 tumors in BDF1 mice was effected by oral tegafur (FT) in combination with oral (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVdUrd), at doses at which neither drug used alone had antitumor activity. The maximum inhibition of tumor growth (97%) was achieved by using a combination of 50 mg FT/kg with 10 mg BVdUrd/kg but, even at a dose as low as 1 mg BVdUrd/kg, the antitumor potency of FT was enhanced. The effect which BVdUrd has on the antitumor potency of FT is apparently due to inhibitory action by bromovinyluracil, the phosphorolytic product of BVdUrd, on the degradation of 5-fluorouracil, the oxidative product of FT, by dihydrothymine dehydrogenase.

Topics: Adenocarcinoma; Administration, Oral; Animals; Antineoplastic Combined Chemotherapy Protocols; Bromodeoxyuridine; Drug Synergism; Metabolic Clearance Rate; Mice; Neoplasms, Experimental; Tegafur

When combined with bromovinyldeoxyuridine (BVdUrd), 5-fluorouracil (FUra) brought about a significant reduction in the growth of adenocarcinoma 755 tumors in mice, at doses at which either drug used alone (BVdUrd: 100 mg/kg) did not effect an appreciable antitumor activity. BVdUrd also increased the toxicity of FUra for the hosts but not commensurately with its enhancing effect on the antitumor activity of FUra. BVdUrd also potentiated the antitumor activity of ftorafur, so that doses of ftorafur (50 or 100 mg/kg) which by themselves did not cause a significant reduction in tumor growth became markedly effective when combined with BVdUrd at a dose as low as 10 mg/kg. For some combinations of BVdUrd with FUra, the antitumor potency was further enhanced by the administration of L-cysteine (300 mg/kg).

Topics: Adenocarcinoma; Animals; Antineoplastic Combined Chemotherapy Protocols; Bromodeoxyuridine; Cysteine; Drug Evaluation, Preclinical; Drug Synergism; Fluorouracil; Male; Mice; Tegafur