Cellular effects and antitumor activity of RET inhibitor RPI-1 on MEN2A-associated medullary thyroid carcinoma

被引:99
作者
Cuccuru, G
Lanzi, C
Cassinelli, G
Pratesi, G
Tortoreto, M
Petrangolini, G
Seregni, E
Martinetti, A
Laccabue, D
Zanchi, C
Zunino, F
机构
[1] Ist Nazl Tumori, Dept Expt Oncol, Preclin Chemotherapy & Pharmacol Unit, I-20133 Milan, Italy
[2] Ist Nazl Tumori, Nucl Med Unit, I-20133 Milan, Italy
来源
JNCI-JOURNAL OF THE NATIONAL CANCER INSTITUTE | 2004年 / 96卷 / 13期
关键词
D O I
10.1093/jnci/djh184
中图分类号
R73 [肿瘤学];
学科分类号
100214 ;
摘要
Background. The RET proto-oncogene encodes a receptor tyrosine kinase. RET oncogenes arise through sporadic and inherited gene mutations and are involved in the etiopathogenesis of medullary thyroid carcinoma, a cancer that responds poorly to conventional chemotherapy. Medullary thyroid carcinoma is a component of multiple endocrine neoplasia type 2 or MEN2 syndromes. Methods: We investigated the cellular effects of RPI-1, a novel 2-indolinone Ret tyrosine kinase inhibitor on cells that express RET C634 oncogenic mutants common in the MEN2A syndrome: NIH3T3 fibroblasts transfected with RETC634R and human medullary thyroid carcinoma TT cells that express endogenous RETC634W. RPI-1 antiproliferative activity was determined by cell proliferation and anchorage-independent growth assays. Expression and phosphorylation of Ret and of proteins involved in downstream signaling pathways were examined by immunoblotting. Antitumor activity of oral RPI-1 treatment was tested by using two dosing levels in nude mice bearing subcutaneous TT xenograft tumors. All statistical tests were two-sided. Results: The RPI-1 IC50 value for cell proliferation was 3.6 muM (95% confidence interval [CI] = 1.8 to 5.4 muM) in NIH3T3 cells expressing the Ret mutant compared with 16 muM (95% CI = 12.3 to 19.7 muM) in non-transfected NIH3T3 cells, and that for colony formation in soft agar was 2.4 muM (95% CI = 0.8 to 4.0 muM) and 26 muM (95% CI = 17 to 35 muM) in RET mutant-transfected and H-RAS-transfected NIH3T3 cells, respectively. In NIH3T3 cells expressing the Ret mutant, Ret protein and tyrosine phosphorylation were undetectable after 24 hours of RPI-1 treatment. In TT cells, RPI-1 inhibited proliferation, Ret tyrosine phosphorylation, Ret protein expression, and the activation of PLCgamma, ERKs and AKT. In mice, oral daily RPI-1 treatment inhibited the tumor growth of TT xenografts by 81% (P<.001 versus control mice) and reduced the plasma levels of the specific biomarker calcitonin (P=.01 versus control mice). Twenty-five percent of RPI-1-treated mice were tumor-free. Conclusions: Ret oncoproteins represent exploitable targets for therapeutic intervention in MEN2A-associated medullary thyroid carcinoma. The antitumor efficacy and oral bioavailability of RPI-1 support its therapeutic potential.
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收藏
页码:1006 / 1014
页数:9
相关论文
共 43 条
  • [1] Multiple endocrine neoplasia type 2B mutation in human RET oncogene induces medullary thyroid carcinoma in transgenic mice
    Acton, DS
    Velthuyzen, D
    Lips, CJM
    Höppener, JWM
    [J]. ONCOGENE, 2000, 19 (27) : 3121 - 3125
  • [2] [Anonymous], CANC PRINCIPLES PRAC
  • [3] ARMITAGE P, 1987, STATISTICAL METHODS, P411
  • [4] A mutation at tyrosine 1062 in MEN2A-Ret and MEN2B-Ret impairs their transforming activity and association with Shc adaptor proteins
    Asai, N
    Murakami, H
    Iwashita, T
    Takahashi, M
    [J]. JOURNAL OF BIOLOGICAL CHEMISTRY, 1996, 271 (30) : 17644 - 17649
  • [5] Baselga J, 2003, CLIN CANCER RES, V9, P2389
  • [6] Signaling complexes and protein-protein interactions involved in the activation of the Ras and phosphatidylinositol 3-kinase pathways by the c-Ret receptor tyrosine kinase
    Besset, V
    Scott, RP
    Ibáñez, CF
    [J]. JOURNAL OF BIOLOGICAL CHEMISTRY, 2000, 275 (50) : 39159 - 39166
  • [7] BONGARZONE I, 1989, ONCOGENE, V4, P1457
  • [8] Borrello MG, 1995, ONCOGENE, V11, P2419
  • [9] Borrello MG, 1996, MOL CELL BIOL, V16, P2151
  • [10] The roles of phosphotyrosines-294,-404, and-451 in RET/PTC1-induced thyroid tumor formation
    Buckwalter, TLF
    Venkateswaran, A
    Lavender, M
    La Perle, KMD
    Cho, JY
    Robinson, ML
    Jhiang, SM
    [J]. ONCOGENE, 2002, 21 (53) : 8166 - 8172