Purpose: PARP inhibitors (PARPi) are used in a wide range of human solid tumours but a limited evidence is reported in rhabdomyosarcoma (RMS), the most frequent childhood soft-tissue sarcoma. The cellular and molecular effects of Olaparib, a specific PARP1/2 inhibitor, and AZD2461, a newly synthesized PARP1/2/3 inhibitor, were assessed in alveolar and embryonal RMS cells both as single-agent and in combination with ionizing radiation (IR). Methods: Cell viability was monitored by trypan blue exclusion dye assays. Cell cycle progression and apoptosis were measured by flow cytometry, and alterations of specific molecular markers were investigated by, Real Time PCR, Western blotting and immunofluorescence experiments. Irradiations were carried out at a dose rate of 2 Gy (190 UM/min) or 4 Gy (380 UM/min). Radiosensitivity was assessed by using clonogenic assays. Results: Olaparib and AZD2461 dose-dependently reduced growth of both RH30 and RD cells by arresting growth at G2/M phase and by modulating the expression, activation and subcellular localization of specific cell cycle regulators. Downregulation of phospho-AKT levels and accumulation of γH2AX, a specific marker of DNA damage, were significantly and persistently induced by Olaparib and AZD2461 exposure, this leading to apoptosis-related cell death. Both PARPi significantly enhanced the effects of IR by accumulating DNA damage, increasing G2 arrest and drastically reducing the clonogenic capacity of RMS-cotreated cells. Conclusions: This study suggests that the combined exposure to PARPi and IR might display a role in the treatment of RMS tumours compared with single-agent exposure, since stronger cytotoxic effects are induced, and compensatory survival mechanisms are prevented.

PARP inhibitors affect growth, survival and radiation susceptibility of human alveolar and embryonal rhabdomyosarcoma cell lines / Camero, S; Ceccarelli, S; De Felice, F; Marampon, Francesco; Mannarino, O; Camicia, L; Vescarelli, E; Pontecorvi, P; Pizer, B; Shukla, R; Schiavetti, A; Mollace, Mg; Pizzuti, Antonio; Tombolini, V; Marchese, C; Megiorni, F; Dominici, C. - In: JOURNAL OF CANCER RESEARCH AND CLINICAL ONCOLOGY. - ISSN 0171-5216. - 145:1(2019), pp. 137-152. [10.1007/s00432-018-2774-6]

PARP inhibitors affect growth, survival and radiation susceptibility of human alveolar and embryonal rhabdomyosarcoma cell lines

Camero, S
Primo
;
Ceccarelli, S
Secondo
;
De Felice, F;Marampon,;Vescarelli, E;Pontecorvi, P;Schiavetti, A;Mollace, MG;Pizzuti, Antonio;Tombolini, V;Marchese, C;Megiorni, F
Penultimo
;
Dominici, C
Ultimo
2019

Abstract

Purpose: PARP inhibitors (PARPi) are used in a wide range of human solid tumours but a limited evidence is reported in rhabdomyosarcoma (RMS), the most frequent childhood soft-tissue sarcoma. The cellular and molecular effects of Olaparib, a specific PARP1/2 inhibitor, and AZD2461, a newly synthesized PARP1/2/3 inhibitor, were assessed in alveolar and embryonal RMS cells both as single-agent and in combination with ionizing radiation (IR). Methods: Cell viability was monitored by trypan blue exclusion dye assays. Cell cycle progression and apoptosis were measured by flow cytometry, and alterations of specific molecular markers were investigated by, Real Time PCR, Western blotting and immunofluorescence experiments. Irradiations were carried out at a dose rate of 2 Gy (190 UM/min) or 4 Gy (380 UM/min). Radiosensitivity was assessed by using clonogenic assays. Results: Olaparib and AZD2461 dose-dependently reduced growth of both RH30 and RD cells by arresting growth at G2/M phase and by modulating the expression, activation and subcellular localization of specific cell cycle regulators. Downregulation of phospho-AKT levels and accumulation of γH2AX, a specific marker of DNA damage, were significantly and persistently induced by Olaparib and AZD2461 exposure, this leading to apoptosis-related cell death. Both PARPi significantly enhanced the effects of IR by accumulating DNA damage, increasing G2 arrest and drastically reducing the clonogenic capacity of RMS-cotreated cells. Conclusions: This study suggests that the combined exposure to PARPi and IR might display a role in the treatment of RMS tumours compared with single-agent exposure, since stronger cytotoxic effects are induced, and compensatory survival mechanisms are prevented.
AZD2461; olaparib; PARP inhibitors; radiosensitivity; rhabdomyosarcoma
01 Pubblicazione su rivista::01a Articolo in rivista
PARP inhibitors affect growth, survival and radiation susceptibility of human alveolar and embryonal rhabdomyosarcoma cell lines / Camero, S; Ceccarelli, S; De Felice, F; Marampon, Francesco; Mannarino, O; Camicia, L; Vescarelli, E; Pontecorvi, P; Pizer, B; Shukla, R; Schiavetti, A; Mollace, Mg; Pizzuti, Antonio; Tombolini, V; Marchese, C; Megiorni, F; Dominici, C. - In: JOURNAL OF CANCER RESEARCH AND CLINICAL ONCOLOGY. - ISSN 0171-5216. - 145:1(2019), pp. 137-152. [10.1007/s00432-018-2774-6]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1178179
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