Metronomic ceramide analogs inhibit angiogenesis in pancreatic cancer through up-regulation of caveolin-1 and thrombospondin-1 and down-regulation of cyclin D1

Aims. The aims of this study were to evaluate the antitumor and antiangiogenic activity of metronomic ceramide analogs and to investigate their relevant molecular mechanisms. Methods. Human endothelial cells (HMVEC-d, HUVEC) and pancreatic cancer cells (Capan-1, MIAPaCa-2) were treated with the ceramide analogs (C2, AL6, C6 and C8), at low concentrations for 144h to evaluate any antiproliferative and pro-apoptotic effects, inhibition of migration, and to measure the expression of caveolin-1 (CAV-1) and thrombospondin-1 (TSP-1) mRNAs by real time RT-PCR. Assessment of ERK1/2 and Akt phosphorylation, and of CAV-1 and cyclin-D1 protein expression was performed by ELISA. Maximum tolerated dose (MTD) gemcitabine was compared against metronomic doses of the ceramide analogs by evaluating the inhibition of MIAPaCA-2 subcutaneous tumor growth in nude mice. Results. Metronomic ceramide analogs preferentially inhibited cell proliferation and enhanced apoptosis in endothelial cells. Low concentrations of AL6 and C2 caused a significant inhibition of HUVEC cell migration. ERK1/2 and Akt phosphorylation were significantly decreased after metronomic ceramide analog treatment. Such treatment caused the over-expression of CAV-1 and TSP-1 mRNA and protein in endothelial cells, whereas cyclin-D1 protein levels were reduced significantly. The antiangiogenic and antitumor impact in vivo of metronomic C2 and AL6 regimens was similar to that caused by MTD gemcitabine. C6 and C8 did not show any significant in vivo antitumor effects. Conclusions. Metronomic C2 and AL6 analogs have antitumor and antiangiogenic activity, determining the upregulation of CAV-1 and TSP-1 and the suppression of cyclin-D1

Melanocortin Receptor-4 Gene Polymorphisms in Glioblastoma Patients Treated with Concomitant Radio-Chemotherapy.

Melanocortins are peptides with well-recognized antiinflammatory and neuroprotective activity. No data are currently available on melanocortin receptor-4 (MC4R) gene polymorphisms and tumors, including glioblastomas (GBMs), or their relationship with radiotherapy or chemotherapy. The aim of this study was to evaluate the possible predictive/prognostic role of the MC4R SNPs on GBM patients. Fifty-five patients with a proven diagnosis of GBM, treated with radiotherapy and temozolomide, were consecutively enrolled. MC4R gene SNPs (rs17782313, rs489693, rs8087522, rs17700633) were analyzed by a validated TaqMan® SNP genotyping assays. Univariate and multivariate analyses were performed. A P < 0.0125 (Bonferroni's correction) was considered significant ( Clinicaltrial.gov identifier NCT02458508). The median progression-free survival (PFS) and median overall survival (OS) of these patients were 9.54 (95% CI 5.4-14.3) months and 24.9 (95% CI 17.8-34.6) months, respectively. The MC4R rs489693 AA genotype was significantly associated with a shorter PFS and OS. Indeed, with regard to PFS, patients harboring the rs489693 AA genotype had a median PFS of 2.99 months whereas patients with AC/CC genotypes had a median PFS of 10.82 months (P = 0.009). Interestingly, the rs489693 AA patients also had a lower median OS as compared with the median OS of the AC/CC genotypes (10.75 vs. 29.5 months, respectively, P = 0.0001). This study suggests that the MC4R rs489693 AA genotype is significantly associated with a shorter PFS and OS in patients treated with radiotherapy and temozolomide. These findings represent a relevant effort to identify novel clinical markers for RT-CT therapy in GBM to be validated in future pharmacogenetic clinical trials

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

Pharmacodynamic and pharmacogenetic angiogenesis-related markers of first-line FOLFOXIRI plus bevacizumab schedule in metastatic colorectal cancer

BACKGROUND: The identification of molecular and genetic markers to predict or monitor the efficacy of bevacizumab (BV) represents a key issue in the treatment of metastatic colorectal cancer (mCRC). METHODS: Plasma levels of vascular endothelial growth factor (VEGF), placental growth factor (PlGF), soluble VEGF receptor 2 (sVEGFR-2) and thrombospondin-1 (TSP-1) were assessed by ELISA assay at different time points in a cohort of 25 patients enroled in a phase II trial of GONO-FOLFOXIRI plus BV as first-line treatment of mCRC. VEGF: -2578A/C, -1498C/T, -1154A/G, -634C/G and 936C/T; and VEGFR-2: -604A/G, +1192C/T and +1719A/T, polymorphisms were assessed in a total of 54 patients. RESULTS: Treatment with GONO-FOLFOXIRI plus BV determined a prolonged and significant reduction in plasma free, biologically active VEGF concentration. Interestingly, VEGF concentrations remained lower than at baseline also at the time of PD. Conversely, PlGF levels increased during the treatment if compared with baseline, suggesting a possible role in tumour resistance; moreover, sVEGFR-2 increased at the time of PD, as well as TSP-1. No association of assessed polymorphisms with outcome was found. CONCLUSION: Our study suggested the possible mechanisms of resistance to combined therapy in those patients with a progressive disease to be tested in ongoing phase III randomised studies

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

Pharmacokinetic and pharmacogenetic predictive markers of irinotecan activity and toxicity

After the rapid development of new classes of antineoplastic drugs, research activities have focused their efforts to the identification of predictive markers of drug activity and tolerability. Irinotecan (CPT-11) may induce severe toxicities (diarrhea, neutropenia) that limit its clinical use, but the increasing knowledge of its pharmacokinetics offered a potential approach to treatment optimization. Pharmacokinetics, the first area of investigation, has identified markers such as biliary index, the relative extent of conversion and the glucuronidation ratio, which are capable to define the risk for severe side adverse effects. Because of the existence of some issues concerning the adoption of pharmacokinetic strategies to optimize CPT-11 dose and schedule, analyses of genetic polymorphisms seemed to offer a more reliable and safer approach for the identification of patients at risk than pharmacokinetics. In this view, the uridine diphosphate glucuronosil transferase isoform 1A1 (UGT1A1) was associated with significant changes in disposition of CPT-11 and its metabolites, and consequently with treatment-induced toxicities. However, the complex pharmacokinetics of irinotecan and the involvement of several enzymes other than UGT (i.e., carboxyl estherases, CYP450 isoforms), and transmembrane transporters (ABCB1, ABCC1, ABCG2, SLCO1B1) make difficult the identification of patients with an optimal sensitivity and specificity, and a large part of variability among patients still remains unexplained. Furthermore, prospective clinical studies that should demonstrate the reliability of those pharmacokinetic and pharmacogenetic markers are still lacking. In the present review, pharmacokinetic and pharmacogenetic markers will be discussed

Pharmacological effects of the simultaneous and sequential combinations of trifluridine/tipiracil (TAS-102) and 5-fluorouracil in fluoropyrimidine-sensitive colon cancer cells

The aim of this study was to investigate possible synergistic effects in vitro of trifluridine/tipiracil (TAS-102) and 5-fluoruracil (5-FU) on fluoropyrimidine-sensitive colon cancer cell lines of different mutational status in order to build a rational basis for the future use of this combination therapy in adjuvant settings or as a first-line treatment for metastatic disease. Proliferation assays were performed on HT-29 (B-raf mutated), SW-620 (ras mutated), and Caco-2 (wild type) colon cancer cell lines exposed to 120-h treatments of 5-FU, TAS-102 and their different combination schedules (simultaneous, sequential and reverse) at equimolar and non-equimolar ratios. The synergistic, additive and antagonistic effects of 5-FU and TAS-102 were determined by the combination index (CI) and dose reduction index (DRI). Our preclinical in vitro results may suggest an apparently counterintuitive but strongly synergistic combination of 5-FU and TAS-102 in fluoropyrimidine-sensitive colon cancer cells allowing a marked theoretical reduction in the administered doses of both drugs. In particular, this association seems to be highly effective in wild-type colon cancer cells, both in sequential and simultaneous schedules. Together, these data may build a rational basis for the future use of TAS-102 combined with 5-FU in adjuvant settings, or as a first-line treatment for metastatic disease

Irinotecan synergistically enhances the antiproliferative and proapoptotic effects of axitinib in vitro and improves its anticancer activity in vivo

AIMS: To demonstrate the synergistic antiproliferative and proapoptotic activity of irinotecan and axitinib in vitro and the improvement of the in vivo effects on angiogenesis and pancreatic cancer. METHODS: Proliferation and apoptotic assays were performed on human dermal microvascular endothelial cells and pancreas cancer (MIAPaCa-2, Capan-1) cell lines exposed to SN-38, the active metabolite of irinotecan, axitinib, or their simultaneous combination for 72 hours. ERK1/2 and Akt phosphorylation, the vascular endothelial growth factor (VEGF), VEGF receptor-2, and thrombospondin-1 (TSP-1) concentration were measured by ELISAs. ATP7A and ABCG2 gene expression was performed with real-time polymerase chain reaction and SN-38 intracellular concentrations were measured by high-performance liquid chromatography. Capan-1 xenografts in nude mice were treated with irinotecan and axitinib alone or in simultaneous combination. RESULTS: A strong synergistic effect on antiproliferative and proapoptotic activity was found with the axitinib/SN-38 combination on endothelial and cancer cells. ERK1/2 and Akt phosphorylation were significantly inhibited by lower concentrations of the combined drugs in all the cell lines. Axitinib and SN-38 combined treatment greatly inhibited the expression of the ATP7A and ABCG2 genes in endothelial and cancer cells, increasing the SN-38 intracellular concentration. Moreover, TSP-1 secretion was increased in cells treated with both drugs, whereas VEGFR-2 levels significantly decreased. In vivo administration of the simultaneous combination determined an almost complete regression of tumors and tumor neovascularization. CONCLUSIONS: In vitro results show the highly synergistic properties of simultaneous combination of irinotecan and axitinib on endothelial and pancreas cancer cells, suggesting a possible translation of this schedule into the clinics