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Drug repositioning explores the reuse of non-cancer drugs to treat tumors. In this work, we evaluated the effect of the combination of chloroquine and propranolol on colorectal and triple-negative breast cancers. Using as in vitromodels the colorectal cancer cell lines HCT116, HT29, and CT26, and as triple-negative breast cancer models the 4T1, M-406, and MDA-MB-231 cell lines, we evaluated the effect of the drugs combination on the viability, apoptosis, clonogenicity, and cellular migratory capacity. To explore the in vivo effects of the combination on tumor growth and metastasis development we employed graft models in BALB/c, nude, and CBi mice. In vitro studies showed that combined treatment decreased cell viability in a dose-dependent manner and increased apoptosis. Also, we demonstrated that these drugs act synergically and that it affects clonogenicity and migration. In vivo studies indicated that this drug combination was effective on colorectal models but only partially on breast cancer. These results contributed to the search for new and safe treatments for colorectal and triple-negative carcinomas.

Aim: According to the need for the development of new anticancer agents, we have synthetized novel bioactive compounds and aimed to determine their antitumor action. Materials & methods: We describe in vitro studies evaluating the effect of 35 novel chemical compounds on two triple negative murine mammary adenocarcinoma tumors. Results & conclusion: Three compounds were selected because of their high antitumor activity and their low toxicity to normal cells. Their effect on tumor cells apoptosis, clonogenicity and migratory capacity, were determined. We found that the selected compounds showed inhibition of viability and clonogenic capacity, and promotion of apoptosis. They also decreased the migratory capacity of tumor cells. The results obtained suggest the likelihood of their future use as antitumor and/or antimetastatic agents. In spite of the important progress achieved in cancer therapeutics, the percentage of people dying because of cancer is still high. Hence, we need to develop new, effective and nontoxic anticancer agents. We synthetized novel compounds and tested their antitumor effect and toxicity, in order to choose those that are effective and do not affect normal cells and therefore, are suitable for human cancer therapies. We selected three out of 35 compounds that show high antitumor action and low toxicity. Also, we studied the mechanisms by which that effect was achieved. Our next goal is to develop experiments with animals in order to have preclinical data that, hopefully, will lead to the clinical use of one or more of the selected compounds. Fil: Giolito, Maria Virginia. Universidad Nacional de Rosario. Facultad de Ciencias Médicas; Argentina

Ovarian cancer (OC) is the leading cause of death from gynaecological cancer. It is extremely hard to diagnose in the early stages and around 70% of patients present with advanced disease. Metronomic chemotherapy (MCT) is described as the chronic administration of, generally low, equally spaced, doses of chemotherapeutic drugs with therapeutic efficacy and low toxicity. This is an effective and low-cost way to treat several types of tumours, including ovarian cancer. Here, we present six cases of advanced ovarian cancer treated with MCT with low doses of cyclophosphamide, which showed clinical response and stable disease. Fil: Perroud, Herman A. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina Fil: Scharovsky, Graciela Olga. Universidad Nacional de Rosario. Consejo de Investigaciones UNR, Facultad de Ciencias Médicas; Argentina Fil: Rozados, Viviana R. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina Fil: Alasino, Carlos María. Institute of Oncology of Rosario; Argentina

Ovarian cancer (OC) is the leading cause of death from gynaecological cancer. It is extremely hard to diagnose in the early stages and around 70% of patients present with advanced disease. Metronomic chemotherapy (MCT) is described as the chronic administration of, generally low, equally spaced, doses of chemotherapeutic drugs with therapeutic efficacy and low toxicity. This is an effective and low-cost way to treat several types of tumours, including ovarian cancer. Here, we present six cases of advanced ovarian cancer treated with MCT with low doses of cyclophosphamide, which showed clinical response and stable disease.

Background Preclinical results showing therapeutic effect and low toxicity of metronomic chemotherapy with cyclophosphamide (Cy) + celecoxib (Cel) for mammary tumors encouraged its translation to the clinic for treating advanced breast cancer patients (ABCP). Patients and methods A single-arm, mono-institutional, non-randomized, phase II, two-step clinical trial (approved by Bioethics Committee and Argentine Regulatory Authority) was designed. Patients received Cy (50 mg po.d) + Cel (200 mg p.o.bid). Patient eligibility criteria included: ABCP who progressed to anthracyclines, taxanes and capecitabine, ≤4 chemotherapy schemes, with good performance status. Several pro- and anti-angiogenic molecules and cells were determined as biomarkers. Informed consent was signed by all patients. Primary endpoint was clinical benefit (CB). Results Twenty patients were enrolled. Main clinical outcomes were prolonged disease stabilization and partial remission in 10/20 and 1/20 patients, respectively. CB was 55 %, and time to progression (TTP) was 21.1 weeks. Median TTP in patients who achieved CB was 35.6 weeks, and mean overall survival was 44.20 weeks. There were no grade 3/4 toxicities associated with treatment. Circulating endothelial cells (CECs) increased at the time of progression in patients who showed CB (P = 0.014). Baseline CECs and circulating endothelial progenitor cells showed marginal associations with TTP. Serum VEGF decreased (P = 0.050), sVEGFR-2 increased (P = 0.005) and VEGF/sVEGFR-2 ratio decreased during treatment (P = 0.041); baseline VEGF and VEGF/sVEGFR-2 were associated with TTP (P = 0.035 and P = 0.030, respectively), while sVEGFR-2 did not. Conclusions Treatment was effective, showing low toxicity profile and excellent tolerability. The combination had anti-angiogenic effect. Increased levels of CEC could be useful for detecting progression. Baseline VEGF and VEGF/sVEGFR-2 values could be useful as early predictors of response. Trial registration ANMAT#4596/09. Fil: Perroud, Herman A. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina Fil: Alasino, Carlos María. Institute of Oncology of Rosario; Argentina Fil: Rico, María José. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina Fil: Mainetti, Leandro Ernesto. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Argentina Fil: Queralt, Francisco. Institute of Oncology of Rosario; Argentina Fil: Pezzotto, Stella Maris. Research Council of the National University of Rosario (CIUNR); Argentina Fil: Rozados, Viviana R. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina Fil: Scharovsky, O. Graciela. Universidad Nacional de Rosario. Consejo de Investigaciones UNR, Facultad de Ciencias Médicas; Argentina

Metronomic chemotherapy (MCT) involves the chronic administration of doses of chemotherapy drugs that are below the maximum tolerated dose (MTD), at frequent and regular intervals, without extended rest periods [1]. It aims to achieve a balance between efficacy in tumor killing and lack of toxicity. The inhibition of angiogenesis would explain its therapeutic effect [2, 3]. We have demonstrated the antitumor efficacy of MCT with cyclophosphamide (Cy) as a single drug [4] and in combination with celecoxib on mice mammary adenocarcinomas (MA) [5]. Considering the high incidence of mammary tumors in humans, in this study, we analyze the therapeutic efficacy, toxicity and mechanism/s of action of MCT combining Cy and doxorubicin (Dox), in mouse MA tumor-models. Fil: Mainetti, Leandro Ernesto. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Argentina Fil: Mainetti, Leandro Ernesto. Departments of Urology and Pathology. Wayne State University School of Medicine; Detroit; MI; USA Fil: Rico, María José. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina Fil: Fernández Zenobi, María Virginia. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina Fil: Perroud, Herman A. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina Fil: Roggero, Eduardo. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina Fil: Rozados, Viviana R. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina Fil: Scharovsky, Graciela Olga. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina

Background: Metronomic chemotherapy (MCT) with cyclophosphamide (Cy) and celecoxib (Cel) has therapeutic efficacy and low toxicity profile in advanced breast cancer patients (ABCP), but no reliable biomarkers of response have been found yet that allow patient selection for treatment. AIM: To investigate the potential role as biomarkers of pro- and antiangiogenic parameters and evaluate their response in ABCP receiving metronomic Cy 50 mg p.o./day + Cel 400 mg p.o./day. Materials and Methods: Serum levels of vascular endothelial growth factor-C (VEGF-C), soluble VEGF receptors 2 and 3 (sVEGFR-2, sVEGFR-3), were measured at different time points in 13/15 patients included in a phase II trial of MCT with Cy+Cel. Results: Serum levels of sVEGFR-2 and sVEGFR-3 increased significantly during treatment (P = 0.0392; P = 0.0066, respectively). VEGF-C showed no significant modifications. Previous determinations of VEGF and TSP-1 in the same patients were utilized. VEGF/sVEGFR-2, VEGF/TSP-1, and VEGF-C/sVEGFR-3 ratios decreased significantly along the treatment (P = 0.0092; P = 0.0072; P = 0.0141, respectively). Nonsignificant variations were observed for VEGF-C/sVEGFR-2 ratio. Baseline values of VEGF/sVEGFR-2 and VEGF/TSP-1 ratios were associated with time to progression (TTP) (P = 0.0407; P = 0.0394, respectively) meanwhile baseline VEGF was marginally significant (P = 0.0716). Patients with values lower than the 50 th percentile for both ratios showed longer TTP. Conclusions: We have identified the baseline VEGF/sVEGFR-2 and VEGF/TSP-1 ratios as potential biomarkers of response in ABCP treated metronomically with Cy+Cel. This finding warrants its confirmation in a higher number of patients. Fil: Perroud, Herman A. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina Fil: Rico, María José. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina Fil: Alasino, Carlos María. Institute of Oncology of Rosario; Rosario; Argentina. Fil: Pezzotto, Stella Maris. Research Council of the National University of Rosario (CIUNR); Rosario; Argentina. Fil: Rozados, Viviana R. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina. Fil: Scharovsky, Graciela Olga. Institute of Experimental Genetics. School of Medical Sciences. National University of Rosario; Rosario; Argentina.

Aim: Experimental and clinical studies showed that the administration of cyclophosphamide (Cy) in low doses leads to an enhancement of the antitumor immune response. Our objective was to study the modulation, if any, by low dose Cy, of T regulatory (Treg) and natural killer T (NKT) I cells, two cell populations of the innate immune response with opposing effects on the tumors, in a rat B cell lymphoma model. Methods: Inbred e rats were challenged s.c. with L-TACB lymphoma and on day 14 animals were distributed in two groups. Treated: injected i.p. with cyclophosphamide (10mg/kg of body weight) and Control: injected i.p. with saline. Blood samples were taken from days 0 to 21 and the percentage of T regulatory and natural killer T I cells were determined by flow cytometry. Results: We found that the increase of natural and inducible T regulatory cells of peripheral blood achieved during tumor growth was significantly downregulated by cyclophosphamide. On the contrary, natural killer T I cells were not modulated by the treatment. Conclusion: The antimetastatic effect of a single low dose of Cy would be due, at least in part, to downregulation of natural and inducible T regulatory cells.

La investigación básica y pre-clínica en oncología celular y molecular son pilares fundamentales en los que se apoyan la mayoría de los adelantos en la terapéutica del cáncer. Los hallazgos obtenidos y su aplicación en la práctica clínica constituyen la causa del avance sostenido en el tratamiento de la enfermedad neoplásica. El objetivo de este trabajo es resumir y discutir los resultados pre-clínicos en inmunomodulación y anti-angiogénesis para el tratamiento de diversos tipos de tumores, obtenidos en nuestro Instituto durante los últimos 15 años, y la posterior traslación y aplicación del conocimiento experimental en un Ensayo Clínico Fase I/II. Se describen los resultados que contribuyeron a descifrar los mecanismos de acción de la inmunomodulación antimetastásica con ciclofosfamida, la quimioterapia metronómica con diferentes drogas únicas o combinaciones, y finalmente el diseño y resultados preliminares de un ensayo clínico de quimioterapia metronómica para pacientes con cáncer de mama avanzado. Immunomodulation and antiangiogenesis in cancer therapy. From basic to clinical research. Basic and pre-clinic research in cellular and molecular oncology are the main supports accounting for the advancement in cancer therapeutics. The findings achieved, and their implementation in clinical practice are responsible for the permanent improvement in the treatment of the neoplastic disease. Our present objective is to summarize and discuss the pre-clinical findings in immunomodulation and anti-angiogenesis for the treatment of several types of tumors obtained in our Institute during the last 15 years, and the subsequent translation and application of the acquired experimental knowledge in a Phase I/II Clinical Trial. We present the results and mechanisms of action of antimetastatic immunomodulation with cyclophosphamide, the metronomic chemotherapy with different single drugs and their combinations, and finally the design and preliminary results of a clinical trial with metronomic chemotherapy for patients with advanced breast cancer.

The phenomenon by which tumor-bearing hosts are capable of inhibiting secondary tumor implants or metastases, known as concomitant antitumoral resistance (CAR), is presumably due to antiangiogenesis at places distant from the primary tumor. Although angiostatin, a potent inhibitor of angiogenesis, has been reported to be one of the factors responsible for suppressing the growth of secondary tumors in mice bearing previous tumors, it has not been definitively proven yet. With the aim of investigating whether CAR-inducing cancer cells display a differential angiostatin production and to support the role ascribed to that molecule concerning the inhibition of secondary tumor implants, 5 tumor models with different CAR-inducing capacities were studied herein. One of the 2 human lung cancer cell lines analyzed revealed a strong CAR against secondary s.c. tumor implants in nude mice, and 2 of 3 of the murine mammary tumors used exhibited inhibitory effect on secondary s.c. and i.v. tumor inoculations in syngeneic hosts. Since angiostatin is a proteolytic fragment from plasminogen, we examined by Western blot the ability of all conditioned media collected from the tumor cells studied to convert plasminogen to angiostatin. An association between in vivo generation of CAR and in vitro conversion of plasminogen into angiostatin was found. Since different enzymatic mechanisms were described to explain the generation of angiostatin, we also studied gelatinase and urokinase-type plasminogen activator secretion in conditioned media by zymography. The conversion of plasminogen into angiostatin by conditioned media was mainly inhibited by broad-spectrum serine proteinase inhibitors, suggesting a possible role for 1 or more enzymes of that group in the process. These findings suggest the existence of a differential angiostatin generation by CAR-inducing cancer cells, providing additional support to previous data obtained by other authors. Fil: Binda, María Mercedes. Fundación de Investigacián del Cáncer CEFYBO; Argentina. Fil: Matar, Pablo. Universidad Nacional de Rosario. Instituto de Genética Experimental; Facultad de Ciencias Médicas. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET);Argentina. Fil: González, Alejandro D. Fundación de Investigacián del Cáncer CEFYBO; Argentina. Fil: Rozados, Viviana R. Universidad Nacional de Rosario. Instituto de Genética Experimental; Facultad de Ciencias Médicas. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET);Argentina Fil: Gervasoni, Silvia I. Universidad Nacional de Rosario. Instituto de Genética Experimental; Facultad de Ciencias Médicas; Argentina. Fil: Scharovsky, O. Graciela. Universidad Nacional de Rosario. Instituto de Genética Experimental; Facultad de Ciencias Médicas. Consejo Nacional de Investigaciones UNR; Argentina. Fil: Bonfil, R. Daniel. Departments of Urology and Pathology, Wayne State University School of Medicine, Detroit, MI; USA.