taxane and Disease-Models--Animal

Capecitabine (N4-pentyloxycarbonyl-5'-deoxy-5-fluorocytidine) is a novel oral fluoropyrimidine carbamate, which was designed to be sequentially converted to 5-fluorouracil (5-FU) by three enzymes located in the liver and in tumors. N4-alkoxycarbonyl-5'-deoxy-5-fluorocytidine derivatives including capecitabine pass intact through the intestinal tract and are sequentially converted to 5-FU by a cascade of the three enzymes. The first step is the conversion to 5'-deoxy-5-fluorocytidine (5'-DFCR) by carboxylesterase located in the liver, then to 5'-deoxy-5-fluorouridine (5'-DFUR) by cytidine deaminase highly expressed in the liver and various solid tumors, and finally to 5-FU by thymidine phosphorylase (dThdPase) preferentially located in tumor tissues. Among large numbers of the derivatives, capecitabine was selected based on its susceptibility to hepatic carboxylesterase, oral bioavailability in monkeys and efficacy in a human cancer xenograft. Capecitabine given orally yielded substantially higher concentrations of 5-FU within tumors than in plasma or normal tissue (muscle). The tumor 5-FU levels were also much higher than those achieved by intraperitoneal administration of 5-FU at equi-toxic doses. This tumor selective delivery of 5-FU ensured greater efficacy and a more favourable safety profile than with other fluoropyrimidines. In 24 human cancer xenograft models studied, capecitabine was more effective at a wider dose range and had a broader spectrum of antitumor activity than 5-FU, UFT or its intermediate metabolite 5'-DFUR. The susceptibility of the xenografts to capecitabine correlated with tumor dThdPase levels. Moreover, the conversion of 5'-DFUR to 5-FU by dThdPase in tumor was insufficient in a xenograft model refractory to capecitabine. In addition, the efficacy of capecitabine was enhanced by dThdPase up-regulators, such as by taxanes and cyclophosphamide and by X-ray irradiation. The efficacy of capecitabine may, therefore, be optimized by selecting the most appropriate patient population based on dThdPase status and/or by combining it with dThdPase up-regulators. Capecitabine has additional characteristics not found with 5-FU, such as potent antimetastatic and anticachectic actions in mouse tumor models. With these profiles, capecitabine may have substantial potential in cancer treatment.

Topics: Animals; Antineoplastic Agents; Biological Availability; Bridged-Ring Compounds; Capecitabine; Cyclophosphamide; Deoxycytidine; Disease Models, Animal; Drug Administration Schedule; Drug Design; Fluorouracil; Humans; Liver; Mice; Neoplasms; Taxoids; Thymidine Phosphorylase; Up-Regulation

Cabazitaxel (CBZ) is approved for the treatment of docetaxel-resistant castration-resistant prostate cancer (CRPC). However, its efficacy against CRPC is limited, and there are no effective treatments for CBZ-resistant CRPC. This study explored the optimal treatment for CRPC in the post-cabazitaxel setting. PC3 (CBZ-sensitive) and PC3CR cells (CBZ-resistant) were used in this study. We performed in silico drug screening for candidate drugs that could reprogram the gene expression signature of PC3CR cells. The in vivo effect of the drug combination was tested in xenograft mice models. We identified etoposide (VP16) as a promising treatment candidate for CBZ-resistant CRPC. The WST assay revealed that VP16 had a significant antitumor effect on PC3CR cells. PC3CR cells exhibited significantly higher topoisomerase II alpha (TOP2A) expression than PC3 cells. Higher TOP2A expression was a poor prognostic factor in The Cancer Genome Atlas prostate cancer cohort. In the Fred Hutchinson Cancer Research Center dataset, docetaxel-exposed tissues and metastatic tumors had higher TOP2A expression. In addition, VP16 significantly inhibited the growth of tumors generated from both cell lines. Based on these findings, VP16-based chemotherapy may be an optimal treatment for CPRC in the post-CBZ setting.

Topics: Animals; Bridged-Ring Compounds; Cell Line, Tumor; Disease Models, Animal; DNA Repair; DNA Topoisomerases, Type II; Drug Resistance, Neoplasm; Etoposide; Gene Expression; Humans; Immunohistochemistry; Male; Mice; Prostatic Neoplasms; Signal Transduction; Taxoids; Topoisomerase II Inhibitors; Xenograft Model Antitumor Assays

Topics: Animals; Bridged-Ring Compounds; Disease Models, Animal; Female; Humans; Mice; Neoplasms; Programmed Cell Death 1 Receptor; Receptor, EphA2; Taxoids

Targeted therapies that use the signaling pathways involved in prostate cancer are required to overcome chemoresistance and improve treatment outcomes for men. Molecular chaperones play a key role in the regulation of protein homeostasis and are potential targets for overcoming chemoresistance.. We identified FKBP7, a prolyl-peptidyl isomerase overexpressed in docetaxel-resistant and in cabazitaxel-resistant prostate cancer cells. This is the first study to characterize the function of human FKBP7 and explore its role in cancer. We discovered that FKBP7 was upregulated in human prostate cancers and its expression correlated with the recurrence observed in patients receiving docetaxel.. Targeting FKBP7 or the eIF4G-containing eIF4F translation initiation complex could be novel therapeutic strategies to eradicate taxane-resistant prostate cancer cells.

Topics: Animals; Antineoplastic Agents; Bridged-Ring Compounds; Calcium-Binding Proteins; Cell Line, Tumor; Computational Biology; Disease Models, Animal; Disease Progression; Drug Resistance, Neoplasm; Eukaryotic Initiation Factor-4F; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Gene Silencing; Humans; Male; Mice; Prostatic Neoplasms; Protein Binding; RNA, Small Interfering; Tacrolimus Binding Proteins; Taxoids; Transcriptome; Xenograft Model Antitumor Assays

Although chemotherapy is a conventional cancer treatment, it may induce a protumorigenic microenvironment by triggering the release of proinflammatory mediators. In this study, we demonstrate that ovarian tumor cell debris generated by first-line platinum- and taxane-based chemotherapy accelerates tumor progression by stimulating a macrophage-derived "surge" of proinflammatory cytokines and bioactive lipids. Thus, targeting a single inflammatory mediator or pathway is unlikely to prevent therapy-induced tumor progression. Here, we show that combined pharmacological abrogation of the cyclooxygenase-2 (COX-2) and soluble epoxide hydrolase (sEH) pathways prevented the debris-induced surge of both cytokines and lipid mediators by macrophages. In animal models, the dual COX-2/sEH inhibitor PTUPB delayed the onset of debris-stimulated ovarian tumor growth and ascites leading to sustained survival over 120 days postinjection. Therefore, dual inhibition of COX-2/sEH may be an approach to suppress debris-stimulated ovarian tumor growth by preventing the therapy-induced surge of cytokines and lipid mediators.

Topics: Animals; Antineoplastic Agents; Bridged-Ring Compounds; Carcinoma, Ovarian Epithelial; Cell Proliferation; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cytokines; Disease Models, Animal; Disease Progression; Epoxide Hydrolases; Female; Inflammation; Lipids; Macrophages; Mice; Mice, Inbred C57BL; Mice, SCID; Ovarian Neoplasms; Platinum; Signal Transduction; Taxoids

Antibody-mediated tumour targeting and nanoparticle-mediated encapsulation can reduce the toxicity of antitumour drugs and improve their efficacy. Here, we describe the performance of a nanotherapeutic encapsulating a hydrolytically sensitive docetaxel prodrug and conjugated to an antibody specific for EphA2-a receptor overexpressed in many tumours. Administration of the nanotherapeutic in mice led to slow and sustained release of the prodrug, reduced exposure of active docetaxel in the circulation (compared with administration of the free drug) and maintenance of optimal exposure of the drug in tumour tissue. We also show that administration of the nanotherapeutic in rats and dogs resulted in minimal haematological toxicity, as well as the absence of neutropenia and improved overall tolerability in multiple rodent models. Targeting of the nanotherapeutic to EphA2 improved tumour penetration and resulted in markedly enhanced antitumour activity (compared with administration of free docetaxel and non-targeted nanotherapeutic controls) in multiple tumour-xenografted mice. This nanomedicine could become a potent and safe therapeutic alternative for cancer patients undergoing chemotherapy.

Topics: Animals; Antineoplastic Agents; Bridged-Ring Compounds; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; Docetaxel; Humans; Liposomes; Mice, Inbred NOD; Mice, SCID; Nanoparticles; Receptor, EphA2; Taxoids; Tissue Distribution; Tumor Burden; Xenograft Model Antitumor Assays

Topics: Animals; Antineoplastic Agents, Phytogenic; Bridged-Ring Compounds; Carcinoma, Non-Small-Cell Lung; Disease Models, Animal; Hyperalgesia; Lung Neoplasms; Male; Mice; Mice, Inbred C57BL; Nicotine; Paclitaxel; Peripheral Nervous System Diseases; Receptors, Cholinergic; Taxoids

We hypothesized that platelet levels during therapy could serve as a biomarker for response to therapy and that manipulation of platelet levels could impact responsiveness to chemotherapy.. The medical records of patients with recurrent or progressive ovarian cancer were retrospectively queried for changes in platelet and CA-125 levels during primary therapy. In vitro coculture experiments and in vivo orthotopic models of human ovarian cancer in mice were used to test the effect of modulating platelet levels on tumor growth and responsiveness to docetaxel.. Thrombocytosis at the diagnosis of ovarian cancer was correlated with decreased interval to progression (P = 0.05) and median overall survival (P = 0.007). Mean platelet levels corrected during primary therapy and rose at recurrence. Contrary to treatment-responsive patients, in a cohort of patients refractory to primary therapy, platelet levels did not normalize during therapy. In A2780, HeyA8, and SKOV3-ip1 ovarian cancer cell lines, platelet coculture protected against apoptosis (P < 0.05). In orthotopic models of human ovarian cancer, platelet depletion resulted in 70% reduced mean tumor weight (P < 0.05). Compared with mice treated with docetaxel, mice treated with both docetaxel and platelet-depleting antibody had a 62% decrease in mean tumor weight (P = 0.04). Platelet transfusion increased mean aggregate tumor weight 2.4-fold (P < 0.05), blocked the effect of docetaxel on tumor growth (P = 0.55) and decreased tumor cell apoptosis. Pretransfusion aspirinization of the platelets blocked the growth-promoting effects of transfusion.. Platelet-driven effects of chemotherapy response may explain clinical observations.

Topics: Adult; Aged; Aged, 80 and over; Animals; Antineoplastic Combined Chemotherapy Protocols; Biomarkers; Bridged-Ring Compounds; Cell Line, Tumor; Disease Models, Animal; Disease Progression; Drug Resistance, Neoplasm; Female; Humans; Middle Aged; Neoplasm Recurrence, Local; Ovarian Neoplasms; Platelet Count; Retrospective Studies; Taxoids; Thrombosis; Treatment Outcome; Tumor Burden; Xenograft Model Antitumor Assays

To evaluate the antitumor efficacy against metastatic breast cancer of fluoropyrimidines alone and combined with other chemotherapeutic agents, we developed a murine model of breast cancer metastatic to the lung by orthotopically implanting MDA-MB-435S breast tumors into mice. MDA tumor cells greatly metastasized to lung tissue only after the orthotopically implanted tumors were surgically removed. Measurement of the expression of enzymes involved in 5-FU metabolism showed significantly higher activity of dihydropyrimidine dehydrogenase (DPD) and lower activity of thymidylate synthase (TS) in the MDA metastases than in the orthotopically implanted tumors. Based on the enzymatic properties of metastatic tumors, the minimum toxic doses of UFT (17.5 mg/kg/day) as a DPD-inhibitory fluoropyrimidine (DIF), and of 5'-DFUR (120 mg/kg/day) as a non-DIF, were orally administered to mice with pulmonary metastasis of the breast tumor. The results showed that UFT significantly inhibited the growth of pulmonary metastases of the breast tumors, but 5'-DFUR did not. UFT seemed to inhibit the growth of the pulmonary metastases of the breast tumors in combination with paclitaxel (50 mg/kg) more than in combination with 5'-DFUR, although the antitumor efficacy of neither combination was significantly different from that of paclitaxel alone. These results suggest that combination of DIF with other chemotherapeutic drugs, such as taxanes, is required to attain high antimetastatic and antitumor efficacy against breast tumor metastases, based on the molecular characteristics of the metastatic tumors.

Topics: Aminoacridines; Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Bridged-Ring Compounds; Disease Models, Animal; Drug Combinations; Female; Floxuridine; Humans; Lung Neoplasms; Mice; Mice, Inbred ICR; Mice, SCID; Neoplasm Transplantation; Taxoids; Tegafur; Uracil