Disruption of mutated BRAF signaling modulates thyroid cancer phenotype.
Disruption of mutated BRAF signaling modulates thyroid cancer phenotype.
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DOI：
10.1186/1756-0500-7-187
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发表时间：
2014-03-28
影响因子：
1.8
通讯作者：
Tiwari RK
中科院分区：
文献类型：
--
作者：
Hanly EK;Rajoria S;Darzynkiewicz Z;Zhao H;Suriano R;Tuli N;George AL;Bednarczyk R;Shin EJ;Geliebter J;Tiwari RK
甲状腺癌是美国最常见的内分泌相关癌症，其发病率正在迅速上升。由于在甲状腺癌中发现的各种遗传病变中，BRAFV600E突变存在于50%的乳头状甲状腺癌和25%的未分化甲状腺癌中，该突变为靶向药物治疗提供了机会。我们的实验室在正常BRAF野生型甲状腺细胞和BRAFV600E阳性乳头状甲状腺癌细胞中评估了对PLX4032（一种BRAFV600E特异性抑制剂）治疗的细胞表型效应。对正常BRAF野生型甲状腺细胞和BRAFV600E突变的乳头状甲状腺癌细胞进行增殖测定，并通过免疫荧光分析细胞死亡。细胞周期状态使用EdU摄取测定法，随后通过激光扫描细胞术测定。此外，通过Western印迹分析MAPK信号转导通路中的蛋白质的表达。PLX4032在BRAF突变的甲状腺癌细胞中具有选择性的强效抗增殖作用。这些作用似乎是由药物抑制促生存MAPK途径中BRAF下游信号分子磷酸化的活性介导的。有趣的是，PLX4032促进BRAF野生型甲状腺细胞中这些信号分子的磷酸化。这些发现支持进一步评估联合治疗，包括BRAFV600E抑制剂在甲状腺癌患者携带BRAFV600E突变。
Thyroid cancer is the most common endocrine-related cancer in the United States and its incidence is rising rapidly. Since among various genetic lesions identified in thyroid cancer, the BRAFV600E mutation is found in 50% of papillary thyroid cancers and 25% of anaplastic thyroid cancers, this mutation provides an opportunity for targeted drug therapy. Our laboratory evaluated cellular phenotypic effects in response to treatment with PLX4032, a BRAFV600E-specific inhibitor, in normal BRAF-wild-type thyroid cells and in BRAFV600E-positive papillary thyroid cancer cells. Normal BRAF-wild-type thyroid cells and BRAFV600E-mutated papillary thyroid cancer cells were subjected to proliferation assays and analyzed for cell death by immunofluorescence. Cell cycle status was determined using an EdU uptake assay followed by laser scanning cytometry. In addition, expression of proteins within the MAPK signal transduction pathway was analyzed by Western blot. PLX4032 has potent anti-proliferative effects selectively in BRAF-mutated thyroid cancer cells. These effects appear to be mediated by the drug’s activity of inhibiting phosphorylation of signaling molecules downstream of BRAF within the pro-survival MAPK pathway. Interestingly, PLX4032 promotes the phosphorylation of these signaling molecules in BRAF-wild-type thyroid cells. These findings support further evaluation of combinational therapy that includes BRAFV600E inhibitors in thyroid cancer patients harboring the BRAFV600E mutation.