Anti-tumoral Effect of a Cell Penetrating and Interfering Peptide Targeting PP2A/SET Interaction

Objective: To test cell penetrating and interfering peptide Mut3DPT-PP2A/SET in interaction between serine threonine phosphatase PP2A and its physiological inhibitor, the oncoprotein SET. Materials and methods: Adult male C3H/S-strain mice, 60 days old, were given a graft of breast adenocarcinoma cells (TN60) into subcutaneous tissue. Mut3DPT-PP2A/SET peptide was used to block PP2A and SET oncoprotein interaction. The graft-bearing animals were divided into a control group (injected with saline buffer), and an intervention group injected intraperitoneally with Mut3DPTPP2A/ SET peptide (5 mg/kg) every day from day 5 to day 37. The variables we used to compare the outcome in both groups were tumor size in mm (length×width) and histological changes. In the statistical analysis we used ANOVA and Student-Keuls multiple comparisons test and Tuckey for the post-test analysis. Results: 48 mice were grafted at day 0 with breast UNLP-C3H/S tumor cells, and after randomization, they were assigned to one of the two study groups. At day 5 all mice were injected either with placebo or with the peptide. The treated group showed significant tumor reduction (p<0.07). Histological changes showed presence of apoptosis and necrosis of tumor in treated group. Conclusion: The peptide Mut3DPT-PP2A/SET has demonstrated anti-tumor activity by reduction in vivo of tumor growth becoming a promising future in anticancer therapy.Facultad de Ciencias Médica

Distinct expression patterns of the E3 ligase SIAH-1 and its partner Kid/KIF22 in normal tissues and in the breast tumoral processes

SIAH proteins are the human members of an highly conserved family of E3 ubiquitin ligases. Several data suggest that SIAH proteins may have a role in tumor suppression and apoptosis. Previously, we reported that SIAH-1 induces the degradation of Kid (KIF22), a chromokinesin protein implicated in the normal progression of mitosis and meiosis, by the ubiquitin proteasome pathway. In human breast cancer cells stably transfected with SIAH-1, Kid/KIF22 protein level was markedly reduced whereas, the Kid/KIF22 mRNA level was increased. This interaction has been further elucidated through analyzing SIAH and Kid/KIF22 expression in both paired normal and tumor tissues and cell lines. It was observed that SIAH-1 protein is widely expressed in different normal tissues, and in cells lines but showing some differences in western blotting profiles. Immunofluorescence microscopy shows that the intracellular distribution of SIAH-1 and Kid/KIF22 appears to be modified in human tumor tissues compared to normal controls. When mRNA expression of SIAH-1 and Kid/KIF22 was analyzed by real-time PCR in normal and cancer breast tissues from the same patient, a large variation in the number of mRNA copies was detected between the different samples. In most cases, SIAH-1 mRNA is decreased in tumor tissues compared to their normal counterparts. Interestingly, in all breast tumor tissues analyzed, variations in the Kid/KIF22 mRNA levels mirrored those seen with SIAH-1 mRNAs. This concerted variation of SIAH-1 and Kid/KIF22 messengers suggests the existence of an additional level of control than the previously described protein-protein interaction and protein stability regulation. Our observations also underline the need to re-evaluate the results of gene expression obtained by qRT-PCR and relate it to the protein expression and cellular localization when matched normal and tumoral tissues are analyzed

Pioglitazone together with imatinib in chronic myeloid leukemia: A proof of concept study

BACKGROUND We recently reported that peroxisome proliferator‐activated receptor γ agonists target chronic myeloid leukemia (CML) quiescent stem cells in vitro by decreasing transcription of STAT5. Here in the ACTIM phase 2 clinical trial, we asked whether pioglitazone add‐on therapy to imatinib would impact CML residual disease, as assessed by BCR‐ABL1 transcript quantification. METHODS CML patients were eligible if treated with imatinib for at least 2 years at a stable daily dose, having yielded major molecular response (MMR) but not having achieved molecular response 4.5 (MR4.5) defined by BCR‐ABL1/ABL1 IS RNA levels ≤ 0.0032%. After inclusion, patients started pioglitazone at a dosage of 30 to 45 mg/day in addition to imatinib. The primary objective was to evaluate the cumulative incidence of patients having progressed from MMR to MR4.5 over 12 months. RESULTS Twenty‐four patients were included (age range, 24‐79 years). No pharmacological interaction was observed between the drugs. The main adverse events were weight gain in 12 patients and a mean decrease of 0.4 g/dL in hemoglobin concentration. The cumulative incidence of MR4.5 was 56% (95% confidence interval, 37%‐76%) by 12 months, despite a wide range of therapy duration (1.9‐15.5 months), and 88% of 17 evaluable patients who were still on imatinib reached MR4.5 by 48 months. The cumulative incidence of MMR to MR4.5 spontaneous conversions over 12 months was estimated to be 23% with imatinib alone in a parallel cohort of patients. CONCLUSION Pioglitazone in combination with imatinib was well tolerated and yielded a favorable 56% rate. These results provide a proof of concept needing confirmation within a randomized clinical trial (EudraCT 2009‐011675‐79). Cancer 2017;123:1791–1799. © 2016 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes

Interfering peptides targeting protein–protein interactions: the next generation of drugs?

International audienceProtein-protein interactions (PPIs) are well recognized as promising therapeutic targets. Consequently, interfering peptides (IPs) - natural or synthetic peptides capable of interfering with PPIs - are receiving increasing attention. Given their physicochemical characteristics, IPs seem better suited than small molecules to interfere with the large surfaces implicated in PPIs. Progress on peptide administration, stability, biodelivery and safety are also encouraging the interest in peptide drug development. The concept of IPs has been validated for several PPIs, generating great expectations for their therapeutic potential. Here, we describe approaches and methods useful for IPs identification and in silico, physicochemical and biological-based strategies for their design and optimization. Selected promising in-vivo-validated examples are described and advantages, limitations and potential of IPs as therapeutic tools are discussed

Противоопухолевый эффект клеточнопроникающего и интерферирующего пептида, нацеленного на взаимодействие PP2A / SET

OBJECTIVE: To test cell penetrating and interfering peptide Mut3DPT-PP2A/SET in interaction between serine threonine phosphatase PP2A and its physiological inhibitor, the oncoprotein SET. MATERIALS AND METHODS: Adult male C3H/S-strain mice, 60 days old, were given a graft of breast adenocarcinoma cells (TN60) into subcutaneous tissue. Mut3DPT-PP2A/SET peptide was used to block PP2A and SET oncoprotein interaction. The graft-bearing animals were divided into a control group (injected with saline buffer), and an intervention group injected intraperitoneally with Mut3DPT-PP2A/SET peptide (5 mg/kg) every day from day 5 to day 37. The variables we used to compare the outcome in both groups were tumor size in mm (length×width) and histological changes. In the statistical analysis we used ANOVA and Student-Keuls multiple comparisons test and Tuckey for the post-test analysis. RESULTS: 48 mice were grafted at day 0 with breast UNLP-C3H/S tumor cells, and after randomization, they were assigned to one of the two study groups. At day 5 all mice were injected either with placebo or with the peptide. The treated group showed significant tumor reduction (p<0.07). Histological changes showed presence of apoptosis and necrosis of tumor in treated group. CONCLUSION: The peptide Mut3DPT-PP2A/SET has demonstrated anti-tumor activity by reduction in vivo of tumor growth becoming a promising future in anticancer therapy.Абстракт Цель: Исследовать клеточно-проникающий и интерферирующий пептид Mut3DPT-PP2A / SET при взаимодействии серин-треонинфосфатазы (PP2A) и его физиологического ингибитора, онкопротеина SET. Материалы и методы: Взрослым самцам мышей линии C3H / S в возрасте 60 дней вводили суспензию, содержащую клетки аденокарциномы молочной железы (TN60) в подкожную клетчатку. Пептид Mut3DPT-PP2A / SET использовали для блокирования взаимодействия PP2A и онкопротеина SET. Животные были разделены на контрольную группу (инъецированную солевым буфером) и группу вмешательства, которой внутрибрюшинно вводили пептид Mut3DPT-PP2A / SET (5 мг / кг) ежедневно с 5 по 37 день. Переменные, использованные для сравнения результата в обеих группах были: размер опухоли в мм. (длина х ширина) и гистологические изменения. Для статистического анализа мы использовали тест ANOVA и тест множественных сравнений Student-Keuls и Tuckey для послетестового. Результаты: 48 мышам была введена суспензия в день 0 с опухолевыми клетками UNLP-C3H / S из молочной железы и после рандомизированного отбора их разделили на две группы. На 5-й день всем мышам вводили либо плацебо, либо пептид. Обработанная группа показала значительное уменьшение опухоли (p.0.07). Гистологические изменения выявили наличие апоптоза и некроза опухоли в обработанной группе. Выводы: Пептид Mut3DPT-PP2A / SET демонстрирует противоопухолевую активность, уменьшая рост опухоли in vivo, что представляет собой многообещающее будущее для противоопухолевой терапии.Fil: Andrini, Laura Beatríz. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Ciencias Básicas. Cátedra de Histología y Embriología; ArgentinaFil: Marin, Gustavo Horacio. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Ciencias Básicas. Cátedra de Histología y Embriología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Inda, Ana María. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Ciencias Básicas. Cátedra de Histología y Embriología; ArgentinaFil: Bruzzoni Giovanelli, Heriberto. Université Paris Diderot - Paris 7; FranciaFil: Garcia, Marcela. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Ciencias Básicas. Cátedra de Histología y Embriología; ArgentinaFil: Errecalde, Jorge Oscar. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Ciencias Básicas. Cátedra de Histología y Embriología; ArgentinaFil: Rebollo, Angelita. Sorbonne University; Francia. Inserm; Franci

Case Report Lung Abnormalities after Dasatinib Treatment for Chronic Myeloid Leukemia A Case Series

Tyrosine kinase inhibitors have revolutionized the treatment of chronic myeloid leukemia and are increasingly used for other indications. Fluid retention, however, including pleural effusions, are a significant side effect of imatinib, the first-line treatment for chronic myeloid leukemia. We investigated pleural and pulmonary complications in patients treated with dasatinib, a novel multitargeted tyrosine kinase inhibitor, as part of clinical trial protocols. Of 40 patients who received dasatinib (70 mg twice daily) for imatinib resistance or intolerance, 9 (22.5%) developed dyspnea, cough, and chest pain. Of these nine patients, six had pleural effusions (all were exudates) and seven had lung parenchyma changes with either ground-glass or alveolar opacities and septal thickening (four patients had both pleural effusions and lung parenchyma changes). Lymphocytic accumulations were detected in pleural and bronchoalveolar lavage fluids in all patients except for one who presented with neutrophilic alveolitis. Pleural biopsies revealed lymphocytic infiltration in one patient and myeloid infiltration in another. After dasatinib interruption, lung manifestations resolved in all cases and did not recur in three of four patients when dasatinib was reintroduced at a lower dose (40 mg twice daily). Thus, lung physicians should be aware that lung manifestations, presumably related to an immune-mediated mechanism rather than fluid retention, may occur with dasatinib treatment

Identification of peptides interfering with the LRRK2/PP1 interaction

International audienceSerine/threonine phosphatases are responsible for modulating the activities of the protein kinases implicated in the development of several pathologies. Here we identified by a PEP-scan approach a peptide of LRRK2, a Parkinson's disease associated protein, interacting with the phosphatase PP1. In order to study its biological activity, the peptide was fused via its N-terminal to an optimized cell penetrating peptide. We synthesized from the original peptide five interfering peptides and identified two (Mut3DPT-LRRK2-Short and Mut3DPT-LRRK2-Long) able to disrupt the LRRK2/PP1 interaction by competition in anti-LRRK2 immunoprecipitates. Using FITC-labelled peptides, we confirmed their internalization into cell lines as well as into primary cells obtained from healthy or ill human donors. We confirmed by ELISA test the association of Mut3DPT-LRRK2-Long peptide to purified PP1 protein. The peptides Mut3DPT-LRRK2-5 to 8 with either N or C-terminal deletions were not able to disrupt the association LRRK2/PP1 nor to associate with purified PP1 protein. The interfering sequences blocking the PP1/LRRK2 interaction were also fused to a shuttle peptide able to cross the blood brain barrier and showed that the newly generated peptides BBB-LRRK2-Short and BBB-LRRK2-Long were highly resistant to protease degradation. Furthermore, they blocked PP1/LRRK2 interaction and they penetrated into cells. Hence, these newly generated peptides can be employed as new tools in the investigation of the role of the LRRK2/PP1 interaction in normal and pathological conditions