Myc down-regulation sensitizes melanoma cells to radiotherapy by inhibiting MLH1 and MSH2 mismatch repair proteins

被引:46
作者
Bucci, B
D'Agnano, I
Amendola, D
Citti, A
Raza, GH
Miceli, R
De Paula, U
Marchese, R
Albini, S
Felsani, A
Brunetti, E
Vecchione, A
机构
[1] Fratebenefratelli Hosp, Assoc Fatebenefratelli Ric Canc Ric S Pietro, I-00189 Rome, Italy
[2] Fratebenefratelli Hosp, Unita Radioterapia Oncol S Pietro, I-00189 Rome, Italy
[3] II Fac Med La Sapienza, Cattedra Oncol Med 2, Rome, Italy
[4] CNR, Ist Tecnol Biomed, I-20133 Milan, Italy
[5] Univ Milan, Dipartimento Farmacol, Milan, Italy
[6] Ist Neurobiol & Med Mol, Milan, Italy
关键词
D O I
10.1158/1078-0432.CCR-04-1582
中图分类号
R73 [肿瘤学];
学科分类号
100214 ;
摘要
Purpose: Melanoma patients have a very poor prognosis with a response rate of <1% due to advanced diagnosis. This type of tumor is particularly resistant to conventional chemotherapy and radiotherapy, and the surgery remains the principal treatment for patients with localized melanoma. For this reason, there is particular interest in the melanoma biological therapy. Experimental Design: Using two p53 mutant melanoma models stably expressing an inducible c-myc antisense RNA, we have investigated whether Myc protein down-regulation could render melanoma cells more susceptible to radiotherapy, reestablishing apoptotic p53-independent pathway. In addition to address the role of p53 in the activation of apoptosis, we studied the effect of Myc down-regulation on radiotherapy sensitivity also in a p53 wild-type melanoma cell line. Results: Myc down-regulation is able per se to induce apoptosis in a fraction of the cell population (similar to 40% at 72 hours) and in combination with gamma radiation efficiently enhances the death process. In fact, similar to 80% of apoptotic cells are evident in Myc down-regulated cells exposed to gamma radiation for 72 hours compared with similar to 13% observed after only gamma radiation treatment. Consistent with the enhanced apoptosis is the inhibition of the MLH1 and MSH2 mismatch repair proteins, which, preventing the correction of ionizing radiation mismatches occurring during DNA replication, renders the cells more prone to radiation-induced apoptosis. Conclusions: Data herein reported show that Myc down-regulation lowers the apoptotic threshold in melanoma cells by inhibiting MLH1 and MSH2 proteins, thus increasing cell sensitivity to gamma radiation in a p53-independent fashion. Our results indicate the basis for developing new antitumoral therapeutic strategy, improving the management of melanoma patients.
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页码:2756 / 2767
页数:12
相关论文
共 59 条
[1]   hMSH2 forms specific mispair-binding complexes with hMSH3 and hMSH6 [J].
Acharya, S ;
Wilson, T ;
Gradia, S ;
Kane, MF ;
Guerrette, S ;
Marsischky, GT ;
Kolodner, R ;
Fishel, R .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1996, 93 (24) :13629-13634
[2]   c-Myc is necessary for DNA damage-induced apoptosis in the G2 phase of the cell cycle [J].
Adachi, S ;
Obaya, AJ ;
Han, ZY ;
Ramos-Desimone, N ;
Wyche, JH ;
Sedivy, JM .
MOLECULAR AND CELLULAR BIOLOGY, 2001, 21 (15) :4929-4937
[3]   P53 CONTROLS BOTH THE G(2)/M AND THE G(1) CELL-CYCLE CHECKPOINTS AND MEDIATES REVERSIBLE GROWTH ARREST IN HUMAN FIBROBLASTS [J].
AGARWAL, ML ;
AGARWAL, A ;
TAYLOR, WR ;
STARK, GR .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1995, 92 (18) :8493-8497
[4]  
Bae I, 1996, CANCER RES, V56, P840
[5]   Radiation therapy for malignant melanoma [J].
Ballo, MT ;
Ang, KK .
SURGICAL CLINICS OF NORTH AMERICA, 2003, 83 (02) :323-+
[6]  
Calaf GM, 2004, INT J ONCOL, V25, P1859
[7]   The c-myc oncogene:: use of a biological prognostic marker as a potential target for gene therapy in melanoma [J].
Chana, JS ;
Grover, R ;
Tulley, P ;
Lohrer, H ;
Sanders, R ;
Grobbelaar, AO ;
Wilson, GD .
BRITISH JOURNAL OF PLASTIC SURGERY, 2002, 55 (08) :623-627
[8]   The clinical significance of c-myc oncogene expression in melanomas of the scalp [J].
Chana, JS ;
Grover, R ;
Wilson, GD ;
Hudson, DA ;
Forders, M ;
Sanders, R ;
Grobbelaar, AO .
BRITISH JOURNAL OF PLASTIC SURGERY, 1998, 51 (03) :191-194
[9]   The c-myc transactivation domain is a direct modulator of apoptotic versus proliferative signals [J].
Chang, DW ;
Claassen, GF ;
Hann, SR ;
Cole, MD .
MOLECULAR AND CELLULAR BIOLOGY, 2000, 20 (12) :4309-4319
[10]  
Citro G, 1998, CANCER RES, V58, P283