María José Rico

The Immune Response and the Therapeutic Effect of Metronomic Chemotherapy With Cyclophosphamide

Metronomic chemotherapy (MCT) is a novel therapeutic strategy for cancer treatment endowed with an antiangiogenic effect. It refers to regular administration of low doses of cytotoxic drugs, with minimal or no drug-free breaks. Previously, we demonstrated the immunomodulating activity of a single low-dose of cyclophosphamide (Cy) and the antitumor effect of MCT with Cy on established rat lymphomas and sarcomas. Here, we examined whether the immune response is responsible for the antitumor effect of MCT with Cy on L-TACB lymphoma. Inbred e rats and nude mice were subcutaneously challenged with L-TACB. After 7 days, they were distributed into two experimental groups: 1) treated animals, which were injected IP with Cy (10 mg/kg body weight) three times per week, and 2) control animals, which received IP saline injections. Exponential growth and decay and tumor doubling time were calculated. Also, serum IL-10 levels were measured. One hundred percent of treated rats showed tumor regression versus 0% of control rats. The increase of tumor-induced IL-10 levels was reverted by the treatment with Cy. On the other hand, there were no tumor regressions, in treated or control nude mice. However, the tumor doubling times of treated nude mice were significantly higher than those of control mice, implying that other antitumor mechanism(s), independent of the adaptive immune response, might be taking place. Our present results indicate that modulation of the immune response would be involved in the antitumor effect of MCT with Cy, because the absence of the specific immune response impairs, at least in part, its therapeutic effect in a lymphoma tumor model.

The transition to the metastatic phenotype of rat lymphoma cells involves up-regulation of IL-10 receptor expression and IL-10 secretion.

Interleukin 10 (IL-10) is a Th2 anti-inflammatory cytokine that participates in the regulation of the immune response at several levels. Its production has been implicated in the immunosuppression frequently observed in tumor bearing hosts. The broad spectrum of IL-10 biologic activities is mediated by its binding to its cognate receptor (IL-10R). We have already demonstrated the overproduction of IL-10 by B-cell lymphoma tumor bearing rats and, also, that IL-10 could act as a growth factor for metastatic cells. Considering the importance to unravel each feature of the complex biology of metastasis, the goal of the present study was to investigate the expression of IL-10 receptor (IL-10R), at mRNA and protein level, in primary tumor and metastatic cells from a rat B-cell lymphoma, along with the production of IL-10 by both tumor cell types. Our results indicate that IL-10, besides its immunoregulatory effect, would act as an autocrine growth factor for cells with metastatic phenotype. Also, the up-regulation of IL-10 and IL-10R expression would be part of the transition from primary tumor to the metastatic phenotype.

Metformin and propranolol combination prevents cancer progression and metastasis in different breast cancer models

Discovery of new drugs for cancer treatment is an expensive and time-consuming process and the percentage of drugs reaching the clinic remains quite low. Drug repositioning refers to the identification and development of new uses for existing drugs and represents an alternative drug development strategy. In this work, we evaluated the antitumor effect of metronomic treatment with a combination of two repositioned drugs, metformin and propranolol, in triple negative breast cancer models. By in vitro studies with five different breast cancer derived cells, we observed that combined treatment decreased proliferation (P < 0.001), mitochondrial activity (P < 0.001), migration (P < 0.001) and invasion (P < 0.001). In vivo studies in immunocompetent mice confirmed the potential of this combination in reducing tumor growth (P < 0.001) and preventing metastasis (P < 0.05). Taken together our results suggest that metformin plus propranolol combined treatment might be beneficial for triple negative breast cancer control, with no symptoms of toxicity.

Highlights from the 1st Latin American meeting on metronomic chemotherapy and drug repositioning in oncology, 27-28 May, 2016, Rosario, Argentina.

Following previous metronomic meetings in Marseille (2011), Milano (2014), and Mumbai (2016), the first Latin American metronomic meeting was held in the School of Medical Sciences, National University of Rosario, Rosario, Argentina on 27 and 28 of May, 2016. For the first time, clinicians and researchers with experience in the field of metronomics, coming from different countries in Latin America, had the opportunity of presenting and discussing their work. The talks were organised in three main sessions related to experience in the pre-clinical, and clinical (paediatric and adult) areas. The different presentations demonstrated that the fields of metronomic chemotherapy and repurposing drugs in oncology, known as metronomics, constitute a branch of cancer therapy in permanent evolution, which have strong groups working in Latin America, both in the preclinical and the clinical settings including large, adequately designed randomised studies. It was shown that metronomics offers treatments, which, whether they are combined or not with the standard therapeutic approaches, are not only effective but also minimally toxic, with the consequent improvement of the patient’s quality of life, and inexpensive, a feature very important in low resource clinical settings. The potential use of metronomic chemotherapy was proposed as a cost/effective treatment in low-/middle-income countries, for adjuvant therapy in selected tumours. The fundamental role of the governmental agencies and non-governmental alliances, as the Metronomic Global Health Initiative, in supporting this research with public interest was underlined.

Paclitaxel delivery system based on poly(lactide-co-glycolide) microparticles and chitosan thermo-sensitive gel for mammary adenocarcinoma treatment

To evaluate the combination of more than one release system in the same formulation as a useful strategy to achieve paclitaxel delivery in a more sustained and controlled manner.

Repositioning of Anti-parasitic Drugs in Cyclodextrin Inclusion Complexes for Treatment of Triple-Negative Breast Cancer

Drug repositioning refers to the identification of new therapeutic indications for drugs already approved. Albendazole and ricobendazole have been used as anti-parasitic drugs for many years; their therapeutic action is based on the inhibition of microtubule formation. Therefore, the study of their properties as antitumor compounds and the design of an appropriate formulation for cancer therapy is an interesting issue to investigate. The selected compounds are poorly soluble in water, and consequently, they have low and erratic bioavailability. In order to improve their biopharmaceutics properties, several formulations employing cyclodextrin inclusion complexes were developed. To carefully evaluate the in vitro and in vivo antitumor activity of these drugs and their complexes, several studies were performed on a breast cancer cell line (4T1) and BALB/c mice. In vitro studies showed that albendazole presented improved antitumor activity compared with ricobendazole. Furthermore, albendazole:citrate-β-cyclodextrin complex decreased significantly 4T1 cell growth both in in vitro and in vivo experiments. Thus, new formulations for anti-parasitic drugs could help to reposition them for new therapeutic indications, offering safer and more effective treatments by using a well-known drug.

Quality of life in patients with metastatic breast cancer treated with metronomic chemotherapy

AIM The objective of the study was to detect changes in quality of life (QoL) in metastatic breast cancer patients treated with metronomic chemotherapy with daily low doses of cyclophosphamide and celecoxib. MATERIAL & METHODS Patients included in a Phase II trial, treated with metronomic cyclophosphamide and celecoxib were included in the QoL study. Assessment of QoL was carried out every 2 months by the Functional Assessment of Cancer Therapy Breast (FACT-B) questionnaire, Brief Pain Inventory and Eastern Cooperative Oncologic Group scale. Data were analyzed at three time points: baseline (BL); middle of treatment (MT); and end of treatment (ET). RESULTS A total of 20 patients were included. All patients were heavily pretreated. Treatment showed a good and safe therapeutic profile. With FACT-B questionnaire, no significant differences were observed during the response period (BL-MT). However, a significant increase was observed in the Emotional well-being and Additional concerns axes, when the last time point was included in the analysis (BL-MT-ET). A significant decrease in the proportion of patients with pain was found when comparing BL with ET (p = 0.046). The assessment with Eastern Cooperative Oncologic Group scale showed that 26.7% (4/15) of the patients improved their functional status and 40% (6/15) showed no changes, while 33.3% (5/10) worsened it. CONCLUSION Patients treated metronomically for several months did not worsen their QoL. A high proportion of patients showed improvement or no changes and there were less patients with pain at the end of the treatment.

A mammary adenocarcinoma murine model suitable for the study of cancer immunoediting

BackgroundCancer immunoediting is a dynamic process composed of three phases: elimination (EL), equilibrium (EQ) and escape (ES) that encompasses the potential host-protective and tumor-sculpting functions of the immune system throughout tumor development. Animal models are useful tools for studying diseases such as cancer. The present study was designed to characterize the interaction between mammary adenocarcinoma M-406 and CBi, CBi− and CBi/L inbred mice lines.ResultsThe mammary adenocarcinoma M-406 developed spontaneously in a CBi mouse. CBi/L and CBi− mice were artificially selected for body conformation from CBi. When CBi mice are s.c. challenged with M-406, tumor growths exponentially in 100% of animals, while in CBi− the tumor growths briefly and then begins a rejection process in 100% of the animals. In CBi/L the growth of the tumor shows the three phases: 51.6% in ES, 18.5% in EQ and 29.8% in EL.ConclusionsThe results obtained support the conclusion that the system M-406 plus the inbred mouse lines CBi, CBi− and CBi/L, is a good murine model to study the process of tumor immunoediting.

Abstract 2060: Metronomic chemotherapy (MCT): comparison of the efficacy of two combinations of drugs for the treatment of murine mammary adenocarcinomas.

Metronomic chemotherapy (MCT) refers to the chronic, equally spaced, delivery of low doses of different chemotherapeutic drugs, without extended interruptions. We have developed two combined MCT schemes for the treatment of mammary tumors: A) cyclophosphamide (Cy) 30 mg/kg/day p.o. + celecoxib (Cel) 30 mg/kg p.o. 5 times/week, and B) Cy 20 mg/kg/day p.o. + doxorubicin (Dox) 0.5 mg/kg, 3 times/week i.p. They were tested in two experimental models of mammary adenocarcinomas: I) M-406 and II) M-234p syngeneic with inbred CBi and BALB/c mice, respectively. Our present aim was to compare efficacy and toxicity of MCT combined A and B treatments in both tumor-models. There were analyzed antitumor and antimetastatic effects, survival and toxicity. The % of reduction of tumor volume of animals in the treated group with respect to control group without treatment [median (range): AI: 77.9 (50.9-89.9), AII: 84.4 (30-99.4), BI: 95.6 (57-99.6), BII: 75.5 (62.5-96.8)] didn9t differ between treatments or between tumor-models (non parametric ANOVA). The % of reduction of lung metastatic burden [AI: 99.8 (97.1-99.2) AII: 99.7 (98.7-100), BI: 90.6 (35.9-96.6), BII: 90 (48.4-99.3)] was significantly different among all the groups (P Citation Format: Maria J. Rico, Leandro E. Mainetti, Herman A. Perroud, Viviana R. Rozados, O. Graciela Scharovsky. Metronomic chemotherapy (MCT): comparison of the efficacy of two combinations of drugs for the treatment of murine mammary adenocarcinomas. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2060. doi:10.1158/1538-7445.AM2013-2060

Abstract 701: TUMOR lymphocyte infiltration, expression of CD4, CD8, FOXP3, CD34 molecules and their relationship with tumor evolution after primary treatment in breast cancer patients

Considering that, approximately, only half of breast cancer patients respond to present therapies, a better knowledge of breast cancer biology, one of the most common neoplasms in women, will enable to design better therapeutic approaches. It has been proposed that different tumor characteristics like inflammatory infiltrate intensity, number of T regulatory (Tregs) cells and density of tumor vasculature could be useful to anticipate the response to therapy. Our aim was: a) to analyze the lymphocytic infiltrate and the expression of CD4, CD8, CD34 (endothelial marker) and Foxp3 (Treg marker) in primary tumors of breast cancer patients, and b) to relate them with clinical evolution (disease free: DF or relapsed: R) after 5 years from the primary treatment (surgery). There were analyzed archive samples of ductal mammary tumors (n=27), mostly in stages I and II. The expression of CD4 and CD8 in intra- and peri-tumoral lymphocytes was determined by immunohistochemistry (IHC) and confirmed by confocal microcopy; also the expression of Foxp3 in lymphocytes and tumor cells and CD34 in endothelial cells was evaluated by IHC. The lymphocytic infiltrate was assessed in histological sections stained with hematoxylin-eosin. The quantification was done in 20 high magnification fields and a score ranging from 0 (null) to 6 (high) was utilized. In DF patients (n=22) the intratumoral lymphocytic infiltrate (median [range]: 3 [0-6]) was more intense than that of R patients (n=5), (2 [0-2]), (P=0.05). For CD4, CD8, CD34 and Foxp3 molecules no differences between groups of patients were observed, being their expression highly variable: the score for CD34 varied from 1 to 6 and for the other three molecules from 0 to 6, in either group. In conclusion, the presence of an intense intratumoral lymphocytic infiltrate could be a prognostic marker of good response to treatment, at least in the first 5 years after surgery. These results warrant the study of higher number of tumor samples, since its confirmation could give support for its use in the clinical setting. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 701. doi:1538-7445.AM2012-701