ABSTRACT
Title
Generation of bioluminescent Medulloblastoma mouse models and identification of different tumor progressions in the desmoplastic, classic and anaplastic variants.
Authors
E. De Marco1, C. Camerin1, L. Mezzanotte2, A. Roda2, A. Pession1, P. Hrelia3, R.Tonelli3
1Dept. of Pediatric Oncology and Hematology, Sant’Orsola Hospital. University of Bologna, Italy
2Dept. of Pharmaceutical Sciences. University of Bologna, Italy.
3Dept. of Pharmacology. University of Bologna, Italy.
1Dept. of Pediatric Oncology and Hematology, Sant’Orsola Hospital. University of Bologna, Italy
2Dept. of Pharmaceutical Sciences. University of Bologna, Italy.
3Dept. of Pharmacology. University of Bologna, Italy.
Abstract
Medulloblastoma (MB) is the most common pediatric primary tumor of central nervous system. Currently only 50-60% of the patients are successfully cured and many of the patients who survive exhibit serious side effects due to the very aggressive therapies they underwent (Crawford et al., 2007). The purpose of this work is the development of suitable preclinical mouse model of MB to further investigate the mechanisms involved in the neoplasia to evaluate new therapeutic agents and delivery systems.
The mouse models were created using three MB cell lines derived from three main MB histological variants (Louis et al.,2007): DAOY (desmoplastic variant), D341 (classic variant), D556 (anaplastic variant). The tumor onset and progression has been evaluated with a bioluminescence molecular imaging (BLI) technique based on luciferase reporter gene extracted from the North American firefly (Photinus pyralis) (Rehemtulla et al.,2000;Sadikot et al.,2005). In this regard, before being grafted in mice’s cerebellum, the tumor cells were transfected to permanently express luciferase gene. Afterwards, mice were monitored every seven days by a CCD camera able to detect photons emission after intraperitoneal injection of D-Luciferin.
The mouse models showed an incidence of a 100%, while presented different latency and tumor progression that paralleled those of the clinical course of human MB variants:the desmoplastic variant correlated with a more favourable outcome with an endpoint at 108 days; the classic variant reveals an intermediate outcome with an endpoint at 66 days and a more aggressive outcome in case that tumor spread; the anaplastic variant reveals the worst outcome with an endpoint at 17 days. To validate the BLI as a suitable tool for the monitoring of the MB response to therapy, a group of animals for each MB variants were treated following administration of chemoterapics based on the high-risk medulloblastoma clinical protocol (AIEOP).Mice were injected i.p. following a weekly schedule for five consecutive weeks. The results showed a significant response to treatment as monitored by BLI tumor signal. At the end of the study, an histological characterization of the tumor has been performed.
In vivo molecular bioluminescence imaging allows to follow tumor evolution since the first phases of tumor development, showing good sensibility and specificity. Thus, the created xenograft orthotopic bioluminescent mouse models, reflecting the same clinical course of the histological variants of MB, represent a valid preclinical model to study new drugs for the treatment of this neoplasia.
The mouse models were created using three MB cell lines derived from three main MB histological variants (Louis et al.,2007): DAOY (desmoplastic variant), D341 (classic variant), D556 (anaplastic variant). The tumor onset and progression has been evaluated with a bioluminescence molecular imaging (BLI) technique based on luciferase reporter gene extracted from the North American firefly (Photinus pyralis) (Rehemtulla et al.,2000;Sadikot et al.,2005). In this regard, before being grafted in mice’s cerebellum, the tumor cells were transfected to permanently express luciferase gene. Afterwards, mice were monitored every seven days by a CCD camera able to detect photons emission after intraperitoneal injection of D-Luciferin.
The mouse models showed an incidence of a 100%, while presented different latency and tumor progression that paralleled those of the clinical course of human MB variants:the desmoplastic variant correlated with a more favourable outcome with an endpoint at 108 days; the classic variant reveals an intermediate outcome with an endpoint at 66 days and a more aggressive outcome in case that tumor spread; the anaplastic variant reveals the worst outcome with an endpoint at 17 days. To validate the BLI as a suitable tool for the monitoring of the MB response to therapy, a group of animals for each MB variants were treated following administration of chemoterapics based on the high-risk medulloblastoma clinical protocol (AIEOP).Mice were injected i.p. following a weekly schedule for five consecutive weeks. The results showed a significant response to treatment as monitored by BLI tumor signal. At the end of the study, an histological characterization of the tumor has been performed.
In vivo molecular bioluminescence imaging allows to follow tumor evolution since the first phases of tumor development, showing good sensibility and specificity. Thus, the created xenograft orthotopic bioluminescent mouse models, reflecting the same clinical course of the histological variants of MB, represent a valid preclinical model to study new drugs for the treatment of this neoplasia.