计算模型揭示 MAP3K8 是甲状腺癌干细胞对vemurafenib 耐药的中介。

Computational modeling reveals MAP3K8 as mediator of resistance to vemurafenib in thyroid cancer stem cells.

机构信息

Endocrinology Unit, Department of Clinical and Molecular BioMedicine, Garibaldi-Nesima Medical Center.

Department of Biomedical and Biotechnological Sciences.

出版信息

Bioinformatics. 2019 Jul 1;35(13):2267-2275. doi: 10.1093/bioinformatics/bty969.

DOI:10.1093/bioinformatics/bty969

PMID:30481266

Abstract

MOTIVATION

Val600Glu (V600E) mutation is the most common BRAF mutation detected in thyroid cancer. Hence, recent research efforts have been performed trying to explore several inhibitors of the V600E mutation-containing BRAF kinase as potential therapeutic options in thyroid cancer refractory to standard interventions. Among them, vemurafenib is a selective BRAF inhibitor approved by Food and Drug Administration for clinical practice. Unfortunately, vemurafenib often displays limited efficacy in poorly differentiated and anaplastic thyroid carcinomas probably because of intrinsic and/or acquired resistance mechanisms. In this view, cancer stem cells (CSCs) may represent a possible mechanism of resistance to vemurafenib, due to their self-renewal and chemo resistance properties.

RESULTS

We present a computational framework to suggest new potential targets to overcome drug resistance. It has been validated with an in vitro model based upon a spheroid-forming method able to isolate thyroid CSCs that may mimic resistance to vemurafenib. Indeed, vemurafenib did not inhibit cell proliferation of BRAF V600E thyroid CSCs, but rather stimulated cell proliferation along with a paradoxical over-activation of ERK and AKT pathways. The computational model identified a fundamental role of mitogen-activated protein kinase 8 (MAP3K8), a serine/threonine kinase expressed in thyroid CSCs, in mediating this drug resistance. To confirm model prediction, we set a suitable in vitro experiment revealing that the treatment with MAP3K8 inhibitor restored the effect of vemurafenib in terms of both DNA fragmentation and poly (ADP-ribose) polymerase cleavage (apoptosis) in thyroid CSCs. Moreover, MAP3K8 expression levels may be a useful marker to predict the response to vemurafenib.

AVAILABILITY AND IMPLEMENTATION

The model is available in GitHub repository visiting the following URL: https://github.com/francescopappalardo/MAP3K8-Thyroid-Spheres-V-3.0.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

摘要

动机

Val600Glu（V600E）突变是甲状腺癌中最常见的 BRAF 突变。因此，最近的研究努力一直在探索几种包含 V600E 突变的 BRAF 激酶抑制剂，作为对标准干预措施耐药的甲状腺癌的潜在治疗选择。其中，vemurafenib 是一种被食品和药物管理局批准用于临床实践的选择性 BRAF 抑制剂。不幸的是，vemurafenib 在低分化和间变性甲状腺癌中的疗效往往有限，可能是由于内在和/或获得性耐药机制。在这种情况下，癌症干细胞（CSCs）可能代表对 vemurafenib 耐药的一种可能机制，因为它们具有自我更新和化疗耐药性。

结果

我们提出了一个计算框架来建议克服耐药性的新潜在靶点。它已经通过基于能够分离可能模拟对 vemurafenib 耐药的甲状腺 CSCs 的球体形成方法的体外模型进行了验证。事实上，vemurafenib 并没有抑制 BRAF V600E 甲状腺 CSCs 的细胞增殖，而是刺激细胞增殖，同时 ERK 和 AKT 通路出现反常的过度激活。计算模型确定了丝裂原激活的蛋白激酶 8（MAP3K8）的基本作用，MAP3K8 是一种在甲状腺 CSCs 中表达的丝氨酸/苏氨酸激酶，它介导了这种耐药性。为了证实模型预测，我们进行了合适的体外实验，结果表明，用 MAP3K8 抑制剂处理可恢复 vemurafenib 在甲状腺 CSCs 中 DNA 片段化和多聚（ADP-核糖）聚合酶切割（细胞凋亡）方面的作用。此外，MAP3K8 表达水平可能是预测对 vemurafenib 反应的有用标志物。