Centro de Estudios Biomédicos, Básicos, Biotecnológicos, Aplicados y Desarrollo (CEBBAD), Universidad Maimónides, Hidalgo 775, 6th Floor, Lab 602, 1405, Buenos Aires, Argentina.
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), 1425, Buenos Aires, Argentina.
Cell Mol Biol Lett. 2022 Mar 8;27(1):23. doi: 10.1186/s11658-022-00327-7.
ROR2 is a tyrosine-kinase receptor whose expression is dysregulated in many human diseases. In cancer, ROR2 stimulates proliferation, survival, migration, and metastasis, and is associated with more aggressive tumor stages. The purpose of this work is to study the role of ROR2 in the chemoresistance of melanoma.
Gain- and loss-of-function experiments were used to study the biological function of ROR2 in melanoma. Cell death induced by chemotherapeutic drugs and BH-3 mimetics was evaluated using crystal violet cytotoxicity assays and annexin V/propidium iodide staining. Western blots were used to evaluate the expression of proteins implicated in cell death. The differences observed between cells with manipulation of ROR2 levels and control cells were evaluated using both Student's t-test and ANOVA.
We describe that ROR2 contributes to tumor progression by enhancing the resistance of melanoma cells to both chemotherapeutic drugs and BH-3 mimetics. We demonstrate that ROR2 reduced cell death upon treatment with cisplatin, dacarbazine, lomustine, camptothecin, paclitaxel, ABT-737, TW-37, and venetoclax. This effect was mediated by the inhibition of apoptosis. In addition, we investigated the molecular mechanisms implicated in this role of ROR2. We identified the MDM2/p53 pathway as a novel target of ROR2 since ROR2 positively regulates MDM2 levels, thus leading to p53 downregulation. We also showed that ROR2 also upregulates Mcl-1 and Bcl2-xL while it negatively regulates Bax and Bid expression. The effect of ROR2 on the expression of these proteins is mediated by the hyperactivation of ERK.
These results demonstrate that ROR2 contributes to melanoma progression by inhibiting apoptosis and increasing chemoresistance. These results not only position ROR2 as a marker of chemoresistance but also support its use as a novel therapeutic target in cancer.
ROR2 是一种酪氨酸激酶受体，其表达在许多人类疾病中失调。在癌症中，ROR2 刺激增殖、存活、迁移和转移，并与更具侵袭性的肿瘤阶段相关。本研究的目的是研究 ROR2 在黑色素瘤化疗耐药中的作用。
采用增益和失活实验研究 ROR2 在黑色素瘤中的生物学功能。使用结晶紫细胞毒性测定法和 Annexin V/碘化丙啶染色评估化疗药物和 BH-3 模拟物诱导的细胞死亡。使用 Western blot 评估参与细胞死亡的蛋白表达。使用学生 t 检验和 ANOVA 评估 ROR2 水平调节细胞与对照细胞之间观察到的差异。
我们描述了 ROR2 通过增强黑色素瘤细胞对化疗药物和 BH-3 模拟物的耐药性来促进肿瘤进展。我们证明 ROR2 降低了顺铂、达卡巴嗪、洛莫司汀、喜树碱、紫杉醇、ABT-737、TW-37 和 venetoclax 治疗时的细胞死亡。这种作用是通过抑制细胞凋亡介导的。此外，我们研究了 ROR2 发挥此作用所涉及的分子机制。我们确定了 MDM2/p53 通路是 ROR2 的一个新靶点，因为 ROR2 正向调节 MDM2 水平，从而导致 p53 下调。我们还表明，ROR2 还上调 Mcl-1 和 Bcl2-xL，同时下调 Bax 和 Bid 的表达。ROR2 对这些蛋白表达的影响是通过 ERK 的过度激活介导的。
这些结果表明，ROR2 通过抑制细胞凋亡和增加化疗耐药性促进黑色素瘤进展。这些结果不仅将 ROR2 定位为化疗耐药的标志物，还支持将其用作癌症的新型治疗靶点。
