Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-47700
von Bueren, A O; Oehler, C; Shalaby, T; von Hoff, K; Pruschy, M; Seifert, B; Gerber, N U; Warmuth-Metz, M; Stearns, D; Eberhart, C G; Kortmann, R D; Rutkowski, S; Grotzer, M A (2011). c-MYC expression sensitizes medulloblastoma cells to radio- and chemotherapy and has no impact on response in medulloblastoma patients. BMC Cancer, (11):74.
BACKGROUND: To study whether and how c-MYC expression determines response to radio- and chemotherapy in childhood medulloblastoma (MB).
METHODS: We used DAOY and UW228 human MB cells engineered to stably express different levels of c-MYC, and tested whether c-MYC expression has an effect on radio- and chemosensitivity using the colorimetric 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt (MTS) assay, clonogenic survival, apoptosis assays, cell cycle analysis, and western blot assessment. In an effort to validate our results, we analyzed c-MYC mRNA expression in formalin-fixed paraffin-embedded tumor samples from well-documented patients with postoperative residual tumor and compared c-MYC mRNA expression with response to radio- and chemotherapy as examined by neuroradiological imaging.
RESULTS: In DAOY - and to a lesser extent in UW228 - cells expressing high levels of c-MYC, the cytotoxicity of cisplatin, and etoposide was significantly higher when compared with DAOY/UW228 cells expressing low levels of c-MYC. Irradiation- and chemotherapy-induced apoptotic cell death was enhanced in DAOY cells expressing high levels of c-MYC. The response of 62 of 66 residual tumors was evaluable and response to postoperative radio- (14 responders (CR, PR) vs. 5 non-responders (SD, PD)) or chemotherapy (23 CR/PR vs. 20 SD/PD) was assessed. c-MYC mRNA expression was similar in primary MB samples of responders and non-responders (Mann-Whitney U test, p = 0.50, ratio 0.49, 95% CI 0.008-30.0 and p = 0.67, ratio 1.8, 95% CI 0.14-23.5, respectively).
CONCLUSIONS: c-MYC sensitizes MB cells to some anti-cancer treatments in vitro. As we failed to show evidence for such an effect on postoperative residual tumors when analyzed by imaging, additional investigations in xenografts and larger MB cohorts may help to define the exact function of c-MYC in modulating response to treatment.
|Item Type:||Journal Article, refereed, original work|
|Communities & Collections:||04 Faculty of Medicine > University Children's Hospital Zurich > Medical Clinic|
04 Faculty of Medicine > University Hospital Zurich > Clinic for Radiation Oncology
04 Faculty of Medicine > Institute of Social and Preventive Medicine
|DDC:||610 Medicine & health|
|Deposited On:||23 Mar 2011 15:25|
|Last Modified:||17 Jan 2013 02:20|
|WoS Citation Count:||3|
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