Anna Fioravanti

Antiangiogenic and anticolorectal cancer effects of metronomic irinotecan chemotherapy alone and in combination with semaxinib

Metronomic chemotherapy refers to the administration of chemotherapy at low, nontoxic doses on a frequent schedule with no prolonged breaks. The aim of the study is to rationally develop a CPT-11 metronomic regimen in preclinical settings of colon cancer. In vitro cell proliferation, apoptosis and thrombospondin-1/vascular endothelial growth factor (TSP-1/VEGF) expression analyses were performed on endothelial (HUVEC, HMVEC-d) and colorectal cancer (HT-29, SW620) cells exposed for 144 h to metronomic concentrations of SN-38, the active metabolite of CPT-11. HT-29 human colorectal cancer xenograft model was used, and tumour growth, microvessel density and VEGF/TSP-1 quantification was performed in tumours. In vitro and in vivo combination studies with the tyrosine inhibitor semaxinib were also performed. SN-38 preferentially inhibited endothelial cell proliferation alone and interacted synergistically with semaxinib; it induced apoptosis and increased the expression and secretion of TSP-1. Metronomic CPT-11 alone and combined with semaxinib significantly inhibits tumour growth in the absence of toxicity, which was accompanied by decreases in microvessel density and increases in TSP-1 gene expression in tumour tissues. In vitro results show the antiangiogenic properties of low-concentration SN-38, suggesting a key role of TSP-1 in this effect. In vivo, the CPT-11 metronomic schedule is effective against tumour and microvessel growth without toxic effect on mice.

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.

Clinical and Pharmacodynamic Evaluation of Metronomic Cyclophosphamide, Celecoxib, and Dexamethasone in Advanced Hormone-refractory Prostate Cancer

Purpose: The aims of the present study were to evaluate the clinical activity and the pharmacodynamic profile of the novel schedule of a single i.v. standard dose of cyclophosphamide (CTX) immediately followed by an oral metronomic CTX regimen with celecoxib (CXB) and dexamethasone (DEX) in advanced hormone-refractory prostate cancer patients. Experimental Design: Twenty-eight patients (68% docetaxel-resistant) received 500 mg/m2 CTX i.v. bolus on day 1 and, from day 2, 50 mg/day CTX p.o. plus 200 mg/twice a day CXB p.o. and 1 mg/day DEX p.o. until disease progression. Plasma vascular endothelial growth factor (VEGF) and thrombospondin-1 were detected by ELISA, and real-time reverse transcription-PCR of VEGF and thrombospondin-1 gene expression on peripheral blood mononuclear cell and of VE-cadherin (VE-C) in blood samples was done. Results: A confirmed prostate-specific antigen decrease of ≥50% from baseline was observed in 9 of 28 patients (32%). Median progression-free survival and overall survival were 3 months (95% confidence interval, 2.2-4.2 months) and 21 months (95% confidence interval, 12.4-29.4 months), respectively. Toxicity was mild and no grade 3 to 4 toxicities occurred. A significant relationship was found between plasma VEGF and prostate-specific antigen values (r = 0.4223; P < 0.001). VEGF levels significantly increased in nonresponders, whereas the responder patients maintained significantly lower levels of VE-C gene expression after the beginning of the treatment if compared with nonresponder ones. Conclusion: Metronomic CTX plus CXB and DEX showed favorable toxicity and activity profile in patients. VE-C gene expression and VEGF levels represent potentially useful pharmacodynamic markers for the clinical response.

Fluvastatin synergistically enhances the antiproliferative effect of gemcitabine in human pancreatic cancer MIAPaCa-2 cells

The new combination between the nucleoside analogue gemcitabine and the cholesterol-lowering drug fluvastatin was investigated in vitro and in vivo on the human pancreatic tumour cell line MIAPaCa-2. The present study demonstrates that fluvastatin inhibits proliferation, induces apoptosis in pancreatic cancer cells harbouring a p21ras mutation at codon 12 and synergistically potentiates the cytotoxic effect of gemcitabine. The pharmacologic activities of fluvastatin are prevented by administration of mevalonic acid, suggesting that the shown inhibition of geranyl-geranylation and farnesylation of cellular proteins, including p21rhoA and p21ras, plays a major role in its anticancer effect. Fluvastatin treatment also indirectly inhibits the phosphorylation of p42ERK2/mitogen-activated protein kinase, the cellular effector of ras and other signal transduction peptides. Moreover, fluvastatin administration significantly increases the expression of the deoxycytidine kinase, the enzyme required for the activation of gemcitabine, and simultaneously reduces the 5′-nucleotidase, responsible for deactivation of gemcitabine, suggesting a possible additional role of these enzymes in the enhanced cytotoxic activity of gemcitabine. Finally, a significant in vivo antitumour effect on MIAPaCa-2 xenografts was observed with the simultaneous combination of fluvastatin and gemcitabine, resulting in an almost complete suppression and a marked delay in relapse of tumour growth. In conclusion, the combination of fluvastatin and gemcitabine is an effective cytotoxic, proapoptotic treatment in vitro and in vivo against MIAPaCa-2 cells by a mechanism of action mediated, at least in part, by the inhibition of p21ras and rhoA prenylation. The obtained experimental findings might constitute the basis for a novel translational research in humans.

Aurora B kinase inhibitor AZD1152: determinants of action and ability to enhance chemotherapeutics effectiveness in pancreatic and colon cancer.

Background:AZD1152, the prodrug for AZD1152-hydroxyquinazoline pyrazol anilide (HQPA), is a selective inhibitor of Aurora B kinase activity. Preclinical evaluation of AZD1152 has been reported in several human cancer models. The potentiality of this compound in combination therapy warrants further investigation in solid tumours.Experimental design:This study explored the effects of AZD1152-HQPA in colon and pancreatic tumour cells. The antitumour properties of AZD1152, either as single agent or in combination with chemotherapeutics, were evaluated in each study model. The efficacy and the toxicity of AZD1152 alone and in combination with gemcitabine were validated in pancreatic tumour xenograft model.Results:AZD1152-HQPA treatment resulted in a dramatic increase of chromosome number, modification of cell cycle and induction of apoptosis. The most effective combination was that with chemotherapeutics given soon after AZD1152 in both tumour cell types. The effectiveness of the sequential schedule of AZD1152 with gemcitabine was confirmed in nude mice bearing MiaPaCa-2 tumours, showing inhibition of tumour volumes and delaying of tumour growth after the interruption of the treatments.Conclusion:Here we show that AZD1152-HQPA enhances oxaliplatin and gemcitabine effectiveness in colon and pancreatic cancer, respectively. First, we provide advances into administration schedules and dosing regimens for the combination treatment in in vivo pancreatic tumour.

VEGF-A polymorphisms predict progression-free survival among advanced castration-resistant prostate cancer patients treated with metronomic cyclophosphamide.

Background:No data are available on the pharmacogenetics of metronomic chemotherapy in prostate cancer. The aim of this study was to evaluate the association between VEGF-A sequence variants and prostate-specific antigen (PSA) progression, progression-free survival (PFS) and overall survival (OS), in advanced castration-resistant prostate cancer patients treated with metronomic cyclophosphamide (CTX), celecoxib and dexamethasone.Methods:Forty-three patients were enrolled, and genomic DNA was extracted. VEGF-A gene SNPs (−2578A/C, −634C/G, +936C/T) were analysed using TaqMan PCR assays. Hardy–Weinberg equilibrium was tested for each SNP, and genetic effects were evaluated by Fisher’s exact test. PFS and OS were analysed with GraphPad Prism software, using the product limit method of Kaplan and Meier, and comparing survival curves using both the log-rank test and the Gehan–Wilcoxon test. We used Bonferroni correction to account for multiple testing, and a two-tailed P-value of <0.017 was considered statistically significant.Results:Overall, 20 patients (46%) experienced a reduction in PSA levels from baseline and, among them, 14 (32%) showed a confirmed PSA ≥50% decrease. In non-responders, the −2578CC genotype was more frequent (18.60% vs 2.33% in responders; P=0.0212) whereas the −634CC genotype frequency was 22.73% vs 0% in responders (P=0.0485). With regard to PFS, patients harbouring the −634CC genotype had a median PFS of 2.2 months whereas patients with the genotype −634CG/GG had a median PFS of 6.25 months (P=0.0042).Conclusion:The −634CC genotype is significantly associated with a shorter PFS in patients treated with a metronomic CTX schedule.

CLM3, a Multitarget Tyrosine Kinase Inhibitor With Antiangiogenic Properties, Is Active Against Primary Anaplastic Thyroid Cancer In Vitro and In Vivo

CONTEXT AND OBJECTIVE We have studied the antitumor activity of a pyrazolo[3,4-d]pyrimidine compound (CLM3) proposed for a multiple signal transduction inhibition [including the RET tyrosine kinase, epidermal growth factor receptor, and vascular endothelial growth factor (VEGF) receptor and with antiangiogenic activity] in primary anaplastic thyroid cancer (ATC) cells, in the human cell line 8305C (undifferentiated thyroid cancer), and in an ATC-cell line (AF). DESIGN AND MAIN OUTCOME MEASURES CLM3 was tested in primary ATC cells at the concentrations of 5, 10, 30, and 50 μM; in 8305C cells, in AF cells, at 1, 5, 10, 30, 50, or 100 μM; and in AF cells in CD nu/nu mice. RESULTS CLM3 significantly inhibited the proliferation of 8305C and AF cells, also inducing apoptosis. A significant reduction of proliferation with CLM3 in ATC cells (P < .01, ANOVA) was shown. CLM3 increased the percentage of apoptotic ATC cells dose dependently (P < .001, ANOVA) and inhibited migration (P < .01) and invasion (P < .001). The AF cell line was injected sc in CD nu/nu mice, and tumor masses became detectable 15 days later. CLM3 (50 mg/kg per die) significantly inhibited tumor growth (starting 16 d after the beginning of treatment). CLM3 significantly decreased the VEGF-A expression and microvessel density in AF tumor tissues. Furthermore, CLM3 inhibited epidermal growth factor receptor, AKT, and ERK1/2 phosphorylation and down-regulated cyclin D1 in 8305C and AF cells. CONCLUSIONS The antitumor and antiangiogenic activity of a pyrazolo[3,4-d]pyrimidine compound (CLM3) is very promising in anaplastic thyroid cancer, opening the way to a future clinical evaluation.

In vitro antiangiogenic activity of selective somatostatin subtype-1 receptor agonists.

Background  Endothelial cells of human blood vessels (arteries and veins) show high levels of somatostatin subtype‐1 receptor (sst1). The aim of the present study is to investigate the inhibitory effects of novel somatostatin analogs, highly selective for human sst1, on in vitro angiogenesis and their modulation of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor‐2 (VEGFR‐2) expression.

Pharmacogenetics of antiangiogenic and antineovascular therapies of age-related macular degeneration

Age-related macular degeneration (AMD), the most common age-related disease causing irreversible visual loss in industrialized countries, is a complex and multifactorial illness. Researchers have found components of the complement alternative pathway inside drusen and Bruchs membrane of AMD patients, underlying a possible important role of complement factor H in the pathogenesis of AMD. The neovascular (wet) AMD is the most destructive form and it is characterized by invasion of new blood vessels into subretinal spaces with subsequent exudation and bleeding, resulting in scarring of the macular region and loss of the central vision. The hallmark of the neovascular form is the choroidal neovascularization, where VEGF-A has an important role in the pathogenesis of the disease. SNPs of these genes have recently been investigated as potential pharmacogenetic markers of the antiangiogenic and antineovascular therapy of AMD, which includes verteporfin photodynamic therapy and anti-VEGF-A drugs, such as pegaptanib, bevacizumab and ranibizumab. The CFH rs1061170 CT and TT genotypes have been associated with an improvement of visual acuity in bevacizumab or ranibizumab treated patients, whereas patients harboring VEGF-A rs699946 G allele responded better to bevacizumab-based therapy if compared with patients carrying the A allele. In conclusion, the discovery of pharmacogenetic markers for the personalization of the antiangiogenic and/or antineovascular therapy could be, in the future, a key issue in ophthalmology to obtain a personalization of the therapy and to avoid unnecessary costs and adverse drug reactions.

METRONOMIC CYCLOPHOSPHAMIDE IN ELDERLY PATIENTS WITH ADVANCED, CASTRATION‐RESISTANT PROSTATE CANCER

To the Editor: Metronomic chemotherapyFlow-dose, long-term, frequently administered chemotherapyFhas been found to have an important effect on the stabilization of cancer, including prostate cancer, without any highgrade toxicity. However, no data from prospective metronomic clinical trials are available in elderly patients with cancer. Anecdotal case reports and a small retrospective clinical study on metastatic melanoma have suggested metronomic chemotherapy as an alternative therapy in elderly patients requiring palliation. The present study was a retrospective review of 29 consecutive elderly patients (aged 78) with advanced castration-resistant prostate cancer (CRPC) who had been treated with metronomic cyclophosphamide (50 mg per day by mouth) plus celecoxib (200 mg twice a day by mouth) and dexamethasone (1 mg once daily by mouth) at Pisa University Hospital and Livorno General Hospital. The treatment was given for at least 12 weeks. Median age was 83 (range 78–92); six patients (20%) had an Eastern Cooperative Oncology Group Performance Status (PS) of 0 and 23 (80%) of 1 or more; the median number of comorbidities was 2 (range 0–6), and 19 patients (65%) were deemed frail. Median baseline serum prostate specific antigen (PSA) level was 49.4 ng/mL (range 6.7– 567.8 ng/mL); bone was the most frequent metastatic site (72.4%); two patients had measurable disease (7%). Ten patients (34.5%) received one or more previous chemotherapeutic lines, including docetaxel (9 patients, 31%), mitoxantrone (5 patients, 10%), estramustine phosphate (7 patients, 24%), and vinorelbine and etoposide (1 patient, 3.4%). Zoledronic acid was administered to 19 patients (65.5%). No Grade 3 or 4 hematological or nonhematological toxicities were observed in the 29 assessable patients. Four patients (14%) developed National Cancer InstituteF Common Toxicity Criteria Grade 2 anemia, and two patients (7%) developed Grade 2 thrombocytopenia (one of these patients required cyclophosphamide discontinuation). Neither major cardiovascular events nor toxicity-related deaths were observed. Overall, 18 patients (62%) experienced any reduction in PSA level (a decrease of 2% to 99%); 13 (45%) had a confirmed PSA decrease of 50% or greater. Of the 13 responders (77%), 10 had not received any prior chemotherapy, whereas the remaining three had previously received chemotherapy (median 2 lines of chemotherapy). Moreover, nine of the 16 nonresponders had previously been received chemotherapy, and seven had not. Based on these results, there was not any statistical difference in the clinical activity in this metronomic combination between patients previously treated or untreated (P 5.43; Fisher exact test). One of two patients (7%) with measurable disease according to the Response Evaluation Criteria In Solid Tumors obtained a partial response, and the other showed disease stabilization. Median duration of response of the 18 patients with any reduction in PSA levels was 8.6 months (95% confidence interval (CI) 5 7.6–9.6 months). After a median follow-up of 27.3 months (95% CI 5 18.8–35.8 months), median progression-free survival and median overall survival were 7.7 months (95% CI 5 2.3–13.1 months) and 19.7 months (95% CI 5 12.8– 26.6 months), respectively (Figure 1). Palliative docetaxel plus low-dose prednisone every 3 weeks is the standard treatment for CRPC. The clinical efficacy and tolerability of first-line docetaxel was recently reported on in 175 patients aged 75 and older. The authors observed a favorable safety and efficacy profile of 3 weeks of docetaxel only in ‘‘fit’’ elderly patients with prostate cancer (PS 1). Conversely, 46% of patients received an adapted docetaxel regimen (delivered on a weekly schedule in nearly 90% of the cases) because of their vulnerable condition: aged 80 and older or a PS of 2 or greater. However, this subgroup of patients also experienced severe nonhematological toxicity in approximately 40% of the cases. Such results lead the authors to consider the weekly regimen less safe than reported previously in elderly patients with prostate cancer. Despite the known limitations of a retrospective study with a small sample size, the regimen in the current study was feasible and demonstrated a favorable toxicity profile even in elderly and ‘‘unfit’’ patients with prostate cancer. A good toxicity profile was also seen in patients treated for longer