NRG1/ERBB3 signaling in melanocyte Melan-Ink4a cells. Mus musculus

Neuregulin (NRG) signaling through the receptor tyrosine kinase, ERBB3, is required for embryonic development, and dysregulated signaling has been associated with cancer progression. Here, we show that NRG1/ERBB3 signaling inhibits melanocyte (MC) maturation and promotes undifferentiated, migratory and proliferative cellular characteristics. Embryonic analyses demonstrated that initial MC specification and distribution were not dependent on ERBB3 signaling. However NRG1/ERBB3 signaling was both necessary and sufficient to inhibit differentiation of later stages of MC development in culture. Analysis of tissue arrays of human melanoma samples suggests that ERBB3 signaling may also contribute to metastatic progression of melanoma as ERBB3 was phosphorylated in primary tumors compared with nevi or metastatic lesions. Neuregulin 1-treated MCs demonstrated increased proliferation and invasion and altered morphology concomitant with decreased levels of differentiation genes, increased levels of proliferation genes and altered levels of melanoma progression and metastases genes. ERBB3 activation in primary melanomas suggests that NRG1/ERBB3 signaling may contribute to the progression of melanoma from benign nevi to malignancies. We propose that targeting ERBB3 activation and downstream genes identified in this study may provide novel therapeutic interventions for malignant melanoma. Overall design: Gene expression changes are compared between Melan-Ink4a cells stimulated with NRG1-b1 (NRG1) for 21 days and NRG1 untreated Melan-INK4a cells in triplicate using Affymetrix Mouse GeneChip 1.0 ST chip .

神经调节蛋白（Neuregulin, NRG）通过受体酪氨酸激酶（receptor tyrosine kinase）ERBB3（ERBB3）介导的信号通路对胚胎发育至关重要，该信号通路失调与癌症进展密切相关。本研究证实，NRG1/ERBB3信号通路可抑制黑素细胞（melanocyte, MC）成熟，并赋予其未分化、迁移及增殖的细胞特性。胚胎分析结果显示，黑素细胞的初始特化与分布并不依赖ERBB3信号通路；但在体外培养条件下，NRG1/ERBB3信号通路对于抑制黑素细胞发育后期的分化，既是必需的也是充分的。对人类黑色素瘤样本的组织芯片分析表明，ERBB3信号通路可能参与黑色素瘤的转移性进展：与色素痣或转移病灶相比，原发性肿瘤中的ERBB3呈现磷酸化状态。经NRG1处理的黑素细胞表现出增殖与侵袭能力增强、形态改变，同时伴随分化基因表达水平下调、增殖基因表达上调，以及黑色素瘤进展与转移相关基因的表达异常。原发性黑色素瘤中ERBB3的激活提示，NRG1/ERBB3信号通路可能推动良性色素痣向恶性黑色素瘤的进展。我们提出，靶向ERBB3激活及本研究中鉴定的下游基因，可为恶性黑色素瘤提供全新的治疗干预策略。
实验整体设计：采用Affymetrix Mouse GeneChip 1.0 ST芯片，对经NRG1-b1（NRG1）刺激21天的Melan-Ink4a细胞与未接受NRG1处理的Melan-INK4a细胞进行基因表达变化比较，设置三次生物学重复。