Mukerji Indroneil, Ramkissoon Shakti H, Reddy Kavitha K R, Rameshwar Pranela
New Jersey Medical School (UMDNJ-NJMS), Department of Medicine - Hematology/Oncology, University of Medicine and Dentistry of New Jersey, 185 South Orange Avenue, MSB, Room E-579, Newark, NJ 07103, USA.
J Neurooncol. 2005 Jan;71(2):91-8. doi: 10.1007/s11060-004-9182-2.
Despite intensive therapy, approximately 60-80% of children who are diagnosed with metastatic neuroblastoma (NB) succumb to the disease. NB preferentially metastasizes to the bone marrow (BM). In the present study we used SY5Y and CHP212 (NB cell lines) to study the roles of the preprotachykinin-I (PPT-I) gene and the natural receptors for PPT-I peptides, neurokinin-1 (NK-1) and NK-2, in the biology of NB. PPT-I, NK-1 and NK-2 were constitutively expressed in the NB cells. Functional studies, with specific NK receptor antagonists, showed that PPT-I peptides mediate autocrine proliferation of the NB cells through both NK-1 and NK-2 receptors. Full-length and truncated NK-1 receptors were detected in NB cells. Since there is one copy of the NK-1 gene, we used NK-1-specific siRNA to suppress the expression of NK-1. The NK-1-deficient NB cells showed phenotypes consistent with cell differentiation. Suppression of NK-1 did not appear to cause cell death, as demonstrated by trypan blue exclusion and by undetectable active caspase. NK-1 suppression reduced the proliferation of the NB cells beginning by 10-fold at day 1 and reached a 10(5)-fold reduction by day 10. The NK-1 deficient cells did not proliferate when they were placed as cocultures with BM stroma, which suggests that NK-1 signaling is important for the survival of NB cells in the BM. The results show potential roles for NK receptors in the proliferation of NB.
尽管进行了强化治疗，但约60 - 80%被诊断为转移性神经母细胞瘤（NB）的儿童仍死于该疾病。NB优先转移至骨髓（BM）。在本研究中，我们使用SY5Y和CHP212（NB细胞系）来研究前速激肽原-I（PPT-I）基因以及PPT-I肽的天然受体神经激肽-1（NK-1）和NK-2在NB生物学中的作用。PPT-I、NK-1和NK-2在NB细胞中组成性表达。使用特异性NK受体拮抗剂进行的功能研究表明，PPT-I肽通过NK-1和NK-2受体介导NB细胞的自分泌增殖。在NB细胞中检测到全长和截短的NK-1受体。由于NK-1基因有一个拷贝，我们使用NK-1特异性小干扰RNA（siRNA）来抑制NK-1的表达。NK-1缺陷的NB细胞表现出与细胞分化一致的表型。锥虫蓝排斥试验和未检测到活性半胱天冬酶表明，NK-1的抑制似乎不会导致细胞死亡。NK-1的抑制从第1天开始使NB细胞的增殖减少10倍，到第10天减少到10⁵倍。当NK-1缺陷细胞与BM基质共培养时不增殖，这表明NK-1信号传导对NB细胞在BM中的存活很重要。结果显示NK受体在NB增殖中具有潜在作用。
