Differentiated non-medullary thyroid cancer (NMTC) can be effectively treated by surgery followed by radioactive iodide therapy. However, a small subset of patients shows recurrence due to a loss of iodide transport, a phenotype frequently associated with BRAF V600E mutations. In theory, this should enable the use of existing targeted therapies specifically designed for BRAF V600E mutations. However, in practice, generic or specific drugs aimed at molecular targets identified by next generation sequencing (NGS) are not always beneficial. Detailed kinase profiling may provide additional information to help improve therapy success rates. In this study, we therefore investigated whether serine/threonine kinase (STK) activity profiling can accurately classify benign thyroid lesions and NMTC. We also determined whether dabrafenib (BRAF V600E-specific inhibitor), as well as sorafenib and regorafenib (RAF inhibitors), can differentiate BRAF V600E from non-BRAF V600E thyroid tumors. Using 21 benign and 34 malignant frozen thyroid tumor samples, we analyzed serine/threonine kinase activity using PamChip®peptide microarrays. An STK kinase activity classifier successfully differentiated malignant (26/34; 76%) from benign tumors (16/21; 76%). Of the kinases analyzed, PKC (theta) and PKD1 in particular, showed differential activity in benign and malignant tumors, while oncocytic neoplasia or Graves’ disease contributed to erroneous classifications. Ex vivo BRAF V600E-specific dabrafenib kinase inhibition identified 6/92 analyzed peptides, capable of differentiating BRAF V600E-mutant from non-BRAF V600E papillary thyroid cancers (PTCs), an effect not seen with the generic inhibitors sorafenib and regorafenib. In conclusion, STK activity profiling differentiates benign from malignant thyroid tumors and generates unbiased hypotheses regarding differentially active kinases. This approach can serve as a model to select novel kinase inhibitors based on tissue analysis of recurrent thyroid and other cancers.
分化型非髓样甲状腺癌可通过手术联合放射性碘治疗有效治疗。然而，一小部分患者因碘转运功能丧失而出现复发，该表型常与BRAF V600E突变相关。理论上，这应使针对BRAF V600E突变的现有靶向疗法得以应用。但实践中，针对二代测序鉴定分子靶点的通用或特异性药物并非总能奏效。详细的激酶谱分析可提供补充信息以提升治疗成功率。本研究通过丝氨酸/苏氨酸激酶活性谱分析，探究其能否准确区分甲状腺良性病变与非髓样甲状腺癌，并验证达拉非尼（BRAF V600E特异性抑制剂）及索拉非尼、瑞戈非尼（RAF抑制剂）能否区分BRAF V600E与非BRAF V600E甲状腺肿瘤。采用21例良性及34例恶性甲状腺肿瘤冷冻样本，通过PamChip®肽微阵列分析丝氨酸/苏氨酸激酶活性。STK激酶活性分类器成功区分恶性（26/34；76%）与良性肿瘤（16/21；76%）。在分析的激酶中，PKC（θ）与PKD1在良恶性肿瘤中呈现差异性活性，而嗜酸细胞瘤或格雷夫斯病可能导致误判。离体实验中，BRAF V600E特异性抑制剂达拉非尼通过调控6/92的分析肽段，成功区分BRAF V600E突变型与非突变型甲状腺乳头状癌，该效应在通用抑制剂索拉非尼与瑞戈非尼中未出现。综上，STK活性谱分析可区分甲状腺良恶性肿瘤，并为差异活性激酶研究提供客观依据。该方法可作为基于复发甲状腺癌及其他癌症组织分析筛选新型激酶抑制剂的范式。
肿瘤(癌症)患者之家