Simultaneous, But Not Consecutive, Combination With Folinate Salts Potentiates 5-fluorouracil Antitumor Activity In Vitro and In Vivo

The combination of folinate salts to 5-fluoruracil (5-FU)-based schedules is an established clinical routine in the landscape of the colorectal cancer treatment. The aim of this study was to investigate the pharmacological differences between the sequential administration of folinate salts (1 h before, as in clinical routine) followed by 5-FU and the simultaneous administration of both drugs. Proliferation and apoptotic assays were performed on human colon cancer cells exposed to 5-FU, calcium (CaLV) or disodium (NaLV) levofolinate or their simultaneous and sequential combination for 24 and 72h. TYMS and SLC19A1 gene expression was performed with real time PCR. In vivo experiments were performed in xenografted nude mice, treated with 5-FU escalating doses and CaLV or NaLV alone or in simultaneous and sequential combination. The simultaneous combination of folinate salts and 5-FU was synergistic (NaLV) or additive (CaLV) in a 24h treatment in both cell lines. In contrast, the sequential combination of both folinate salts and 5-FU was antagonistic at 24 and 72h. The simultaneous combination of 5-FU and NaLV or CaLV inhibited TYMS gene expression at 24h, whereas the sequential combination reduced SLC19A1 gene expression. In vivo experiments confirmed the enhanced antitumor activity of the 5-FU+NaLV simultaneous combination with a good toxicity profile, whereas the sequential combination with CaLV failed to potentiate 5-FU activity. In conclusion, only the simultaneous, but not the consecutive, in vitro and in vivo combination of 5-FU and both folinate salt formulations potentiated the antiproliferative effects of the drugs

Potent efficacy of metronomic topotecan and pazopanib combination therapy in preclinical models of primary or late stage metastatic triple-negative breast cancer

Metronomic chemotherapy has shown promising activity in numerous preclinical studies and also some phase II clinical studies involving various tumor types, and is currently undergoing phase III trial evaluation. Triple-negative breast cancer (TNBC) is an aggressive histological subtype with limited treatment options and very poor prognosis following progression after standard chemotherapeutic regimens. Herein, we evaluated the potential therapeutic impact and molecular mechanisms of topotecan administered in a continuous low-dose metronomic (LDM) manner, alone or in concurrent combination with pazopanib, an antiangiogenic tyrosine kinase inhibitor (TKI), in a triple-negative, primary and metastatic breast cancer orthotopic model; potential molecular mechanisms of efficacy were also studied, especially the impact of hypoxic conditions. The combination of metronomic topotecan and pazopanib significantly enhanced antitumor activity compared to monotherapy with either drug and prolonged survival, even in the advanced metastatic survival setting, with a marked decrease in tumor vascularity, proliferative index, and the induction of apoptosis. Significant changes in tumor angiogenesis, cancer cell proliferation, apoptosis, HIF1α levels, HIF-1 target genes and ABCG2 were found both in vitro and in tumor tissue. Notably, the pazopanib and metronomic topotecan combination treatment inhibited expression of HIF1α and ABCG2 genes in cells grown under hypoxic conditions, and this was associated with an increased intracellular concentration of the active form of topotecan. Our results suggest a potential novel therapeutic option for the treatment of metastatic triple-negative breast cancer patients

Lenvatinib exhibits antineoplastic activity in anaplastic thyroid cancer in vitro and in vivo

Lenvatinib is an oral, multitargeted tyrosine kinase inhibitor (TKI) of VEGFR1-VEGFR3, FGFR1-FGFR4, PDGFRα, RET and v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT) signaling networks involved in tumor angiogenesis. We have evaluated the antitumor activity of lenvatinib in primary anaplastic thyroid cancer (ATC) cells, in the human cell line 8305C (undifferentiated thyroid cancer) and in an ATC-cell line (AF). The AF cell line was obtained from the primary ATC cultures and was the one that grew over 50 passages. The effect of lenvatinib (1 and 100 nM; and 1, 10, 25 and 50 μM) was investigated in primary ATC, 8305C and AF cells as well as in AF cells in CD nu/nu mice. Lenvatinib significantly reduced ATC cell proliferation (P<0.01, ANOVA) and increased the percentage of apoptotic ATC cells (P<0.001, ANOVA). Furthermore, lenvatinib inhibited migration (P<0.01) and invasion (P<0.001) in ATC. In addition, lenvatinib inhibited EGFR, AKT and ERK1/2 phosphorylation and downregulated cyclin D1 in the ATC cells. Lenvatinib also significantly inhibited 8305C and AF cell proliferation, increasing apoptosis. AF cells were subcutaneously injected into CD nu/nu mice and tumor masses were observed 20 days later. Tumor growth was significantly inhibited by lenvatinib (25 mg/kg/day), as well as the expression of VEGF-A and microvessel density in the AF tumor tissues. In conclusion, the antitumor and antiangiogenic activities of lenvatinib may be promising for the treatment of anaplastic thyroid cancer, and may consist a basis for future clinical therapeutic applications

Vandetanib has antineoplastic activity in anaplastic thyroid cancer, in vitro and in vivo

The antitumor activity of vandetanib [a multiple signal transduction inhibitor including the RET tyrosine kinase, epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) receptor (VEGFR), ERK and with antiangiogenic activity], in primary anaplastic thyroid cancer (ATC) cells, in the human cell line 8305C [undifferentiated thyroid cancer (TC)] and in an ATC-cell line (AF), was investigated in the present study. Vandetanib (1 and 100 nM; 1, 10, 25 and 50 μM) was tested by WST-1, apoptosis, migration and invasion assays: in primary ATC cells, in the 8305C continuous cell line, and in AF cells; and in 8305C cells in CD nu/nu mice. Vandetanib significantly reduced ATC cell proliferation (P<0.01, ANOVA), induced apoptosis dose-dependently (P<0.001, ANOVA), and inhibited migration (P<0.01) and invasion (P<0.001). Furthermore, vandetanib inhibited EGFR, AKT and ERK1/2 phosphorylation and downregulated cyclin D1 in ATC cells. In 8305C and AF cells, vandetanib significantly inhibited the proliferation, inducing also apoptosis. 8305C cells were injected subcutaneously in CD nu/nu mice and tumor masses became detectable after 30 days. Vandetanib (25 mg/kg/day) significantly inhibited tumor growth and VEGF-A expression and microvessel density in 8305C tumor tissues. In conclusion, the antitumor and antiangiogenic activity of vandetanib is very auspicious in ATC, opening the way to a future clinical evaluation

Clinical, pharmacokinetic and pharmacodynamic evaluations of metronomic UFT and cyclophosphamide plus celecoxib in patients with advanced refractory gastrointestinal cancers

Aims. To evaluate UFT and cyclophosphamide (CTX) based metronomic chemotherapy plus celecoxib (CXB) for the treatment of patients with heavily pre-treated advanced gastrointestinal malignancies. Methods. Thirty-eight patients received 500 mg/mq2 CTX i.v bolus on day 1 and, from day 2, 50 mg/day CTX p.o. plus 100 mg/twice a day UFT p.o. and 200 mg/twice a day CXB p.o. Tegafur, 5-FU, 5-FUH2, GHB and uracil pharmacokinetics were assessed. Plasma vascular endothelial growth factor (VEGF), soluble VE-cadherin (sVE-C) and thrombospondin-1 (TSP-1) levels were detected by ELISA and real-time PCR of CD133 gene expression on peripheral blood mononuclear cell was also performed. Results Seventeen patients (45%) obtained stable disease (SD) with a median duration of 5.8 ms (range, 4.2–7.4). Median progression free survival (PFS) and overall survival (OS) were 2.7 ms (95% CI, 1.6–3.9 ms) and 7.1 ms (95% CI, 4.3–9.9 ms), respectively. No toxicities of grade >1 were observed. Pharmacokinetics of 27 patients (13/14, SD/progressive disease, PD) after the first treatment of UFT revealed that 5-FU AUC and Cmax values greater than 1.313 h x microg/ml and 0.501 microg/ml, respectively, were statistically correlated with stabilization of disease and prolonged PFS/OS. VEGF and sVE-C plasma levels were greater in the PD group when compared to SD group. CD133 expression increased only in the PD patients. Conclusion. Metronomic UFT and CTX with CXB in heavily pre-treated gastrointestinal patients were well tolerated and associated with interesting activity. Potential predictive pharmacokinetic parameters and pharmacodynamic biomarkers have been found

1,2-Benzisothiazole Derivatives Bearing 4-, 5-, or 6-Alkyl/arylcarboxamide Moieties Inhibit Carbonic Anhydrase Isoform IX (CAIX) and Cell Proliferation under Hypoxic Conditions

Three novel series of 1,2-benzisothiazole derivatives have been developed as inhibitors of carbonic anhydrase isoform IX. Compounds 5c and 5j, tested in vitro on the human colon cell line HT-29, blocked the growth of cells cultured under chemically induced hypoxic conditions, displaying a specific activity against cancer cells characterized by CAIX up-regulation. Moreover, a synergistic activity of 5c with SN-38 (the active metabolite of irinotecan) and 5-fluorouracil on cell proliferation under hypoxic conditions was demonstrated

Anti-tumor effects of metronomic topotecan alone and in combination with angiokinase inhibitors: just a mechanism involved?

Low-dose metronomic chemotherapy has shown promising activity in many preclinical and some phase II clinical studies involving various tumor types and is currently undergoing phase III trial evaluation. We evaluate the potential therapeutic impact of a topoisomerase-1 inhibitor, oral topotecan, alone or in concurrent combination with pazopanib, a tyrosine kinase inhibitor (TKI), in mice with primary orthotopic tumors and advanced metastatic disease using a serially selected metastatic variant of the MDA-MB-231 breast cancer-cell line, 231/LM2-4. TKIs significantly enhanced the antitumor activity of low dose metronomic topotecan, which itself had only modest activity. Changes in tumor oxygenation, angiogenesis, proliferation, apoptosis, HIF1α levels, HIF-1 target genes and ABCG2 were evaluated in in vitro experiments and tumor tissue in order to find a possible mechanism involved in the efficacy of the combination oral low-dose daily metronomic chemotherapy, using topotecan and tyrosine kinase inhibitor. The addition of pazopanib to topotecan was associated to an antiproliferative effect and proapoptotic activity on endothelial and cancer cells. Pazopanib and low dose topotecan combined treatment inhibited the expression of HIF1α and ABCG2 genes in cells, increasing the topotecan intracellular concentration. In vivo, low dose topotecan showed an enhanced antitumor activity when administered with pazopanib, with a marked decrease in tumor volume, vascularity and proliferative index, an induction of apoptosis and a remarkable prolongation of survival

Metronomic chemotherapy for metastatic prostate cancer: a 'young' concept for old patients?

Prostate cancer is a common disease in the elderly, and the number of older prostate cancer patients will probably increase with both the aging of the population and the increased rate of screening. In elderly patients with several co-morbidities, cancer management can be complex, and the risk of administering toxic therapy in this setting should be carefully evaluated. Metronomic chemotherapy, i.e. low-dose, long-term, frequently administered chemotherapy, has been shown to have a significant stabilizing effect on cancer and a positive impact on the quality of life of patients, including those with prostate cancer. Given the low toxicity profile of metronomic chemotherapy, elderly patients or patients with co-morbidities may be candidates for a first-line or second-line oral metronomic approach when standard chemotherapies are contraindicated or not acceptable to the patient. Moreover, the possibility of patients being able to spend more time at home is an important component of a palliative treatment such as metronomic chemotherapy. Unfortunately, and despite these considerations, very few data are available on the activity and safety of metronomic chemotherapy in elderly patients. However, retrospective analyses conducted in a small cohort of patients have been published and, notwithstanding their limitations, indicate that novel metronomic schedules are well tolerated, safe and show potentially interesting activity in elderly, 'unfit' (poor performance status) patients with metastatic prostate cancer. Therefore, evaluation of metronomic chemotherapy strategies in prospective, randomized, phase II/III clinical studies of elderly patients with metastatic prostate cancer appears to be warranted