e-7010 and Colonic-Neoplasms

ABT-751 is an orally active antimitotic agent that is currently in Phase II clinical trials. This agent binds to the colchicine site on ss-tubulin and inhibits polymerization of microtubules. This disruption of microtubule dynamics leads to a block in the cell cycle at the G2/M phase, and promotes apoptosis. ABT-751, as a single agent, has antitumor activity against a series of xenograft models including non-small cell lung cancer (NSCLC) and colon cancer. The current studies were conducted to determine whether ABT-751 enhances antitumor activity of standard cytotoxic therapies currently in clinical use.. Efficacy of ABT-751, in combination with cisplatin, 5-FU, and radiation, was evaluated in the Calu-6 NSCLC, HT-29 colon, and HCT-116 colon carcinoma xenograft models, respectively. Tumor-bearing athymic mice were treated with ABT-751 orally once a day at 75 or 100 mg/kg/day on a 5-days-on, 5-days-off schedule for two cycles.. Efficacy of ABT-751 at 100 mg/kg/day was tested in combination with cisplatin at its maximum tolerable dose (MTD) (10 mg/kg/day, i.p. x1) in Calu-6 tumor-bearing athymic mice. The percent treated/control (%T/C) tumor volume ratios on day 38 were 35, 37, and 6, and the percent tumor growth delay (%TGD) values were 71, 65, and 188 for cisplatin, ABT-751 and the combination groups, respectively. HT-29 colon tumors were used to test ABT-751 in combination with an MTD of 5-FU, 30 mg/kg/day, i.p., q.d. x5. The %T/C ratios on day 38 were 22, 28, and 5 and the %TGD values were 75, 75, and 150 for 5-FU, ABT-751, and the combination groups, respectively. Treatment of HCT-116 colon carcinoma tumors with ABT-751, concurrent with the radiation treatment, was able to both enhance radiation-induced tumor regression, and delay the time to recurrence and progression. Growth curves allowed calculation of enhancement of radiation-induced growth delay (defined as the additional time required for a treated tumor to reach four times its original size) of 2, 9, and 12 days, for ABT-751 alone, radiation alone, and the combination, respectively.. Collectively, these studies demonstrate that ABT-751 enhanced efficacy of standard cytotoxic therapies in a variety of tumor xenograft models, and that enhancement was at least additive in all systems.

Topics: Animals; Antimitotic Agents; Antineoplastic Combined Chemotherapy Protocols; Cisplatin; Colonic Neoplasms; Drug Evaluation, Preclinical; Drug Synergism; Fluorouracil; HCT116 Cells; HT29 Cells; Humans; Lung Neoplasms; Mice; Mice, Nude; Radiation-Sensitizing Agents; Sulfonamides; Time Factors; Xenograft Model Antitumor Assays

E7010 is an orally active sulfonamide antitumor agent showing good activity against various subcutaneously inoculated rodent tumors and human tumor xenografts. The purpose of this study was to evaluate the effect of E7010 on liver metastasis and life span of mice bearing orthotopically transplanted murine Colon 38 tumor.. Orthotopic transplantation of murine Colon 38 tumor as intact tissue yielded hepatic metastasis with a high incidence in about 1 month in C57BL/6 mice, and the mice died in about 2 months with cachexia. In this model, the maximum tolerated dose of E7010 (100 mg/kg per day) was administered orally on various schedules, including for 14 days or daily until death, starting at 14 days after transplantation, or for 8 days from 21 days after transplantation.. E7010 showed tumor growth inhibition (T/C=40%) at the orthotopic site similar to that at the subcutaneous site (T/C = 32%) when administered from 14 days after transplantation. When E7010 was started from 21 days after transplantation, it significantly decreased the number of hepatic metastases (control 17.1+/-20.8, E7010 2.6+/-5.3), although inhibition of tumor growth at the orthotopic site was only moderate (T/ C=60%). The administration of E7010 until death produced a significant increase in life span (control 49.8+/-8.9 days, E7010 62.5+/-6.1 days). Although the tumor weight of the E7010-treated group on the day of death was similar to that of the untreated group (control 1.166+/-0.507 g, E7010 1.211+/-0.632 g), there were significantly fewer liver metastases in the E7010-treated group (control 41.3+/-31.1, E7010 2.0+/-2.0).. E7010 suppressed tumor growth at both primary and metastatic sites and increased life span in an orthotopic transplantation model of murine Colon 38 tumor in syngeneic C57BL/6 mice. Hepatic metastasis was inhibited more effectively than the growth of the primary tumor.

Topics: Aminophenols; Animals; Antineoplastic Agents; Colonic Neoplasms; Female; Fluorouracil; Liver Neoplasms, Experimental; Mice; Mice, Inbred BALB C; Neoplasm Transplantation; Sulfonamides

Topics: Animals; Antineoplastic Agents; Cell Division; Colonic Neoplasms; Humans; Leukemia L1210; Leukemia P388; Nasopharyngeal Neoplasms; Sulfonamides; Tropanes; Tumor Cells, Cultured