Department of Oral Pharmacology, School of Dentistry and Institute of Dental Bioscience, BK21 Plus, Chonbuk National University, Jeonju 651-756, Republic of Korea.
Pohang Center for Evaluation of Biomaterials, Pohang, Gyeongbuk, Republic of Korea.
Biomaterials. 2015;53:274-84. doi: 10.1016/j.biomaterials.2015.02.091. Epub 2015 Mar 16.
The aim of this study was to investigate anti-inflammatory and anti-cancer effects of honokiol (HK) in two oral squamous cancer cell carcinoma (OSCC) cell lines, HN22 and HSC4, through the regulation of inducible nitric oxide synthase (iNOS) and endoplasmic reticulum resident protein 44 (ERp44). Griess assay, zymography, and quantitative PCR were performed to study iNOS expression and subsequent nitric oxide (NO) production in OSCC cell lines. Liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomic analysis was used to elucidate the proteins associated with ER stress and cellular cytotoxic response induced by HK. Pull-down assay and molecular modeling were performed to better understand how HK interacts with ERp44. In vitro and in vivo experiments in which ERp44 expression was knocked down were performed to better understand the effects of ERp44 on a cellular level and anti-cancer effects of HK. Expression levels of iNOS and subsequent NO secretion were reduced in OSCC cell lines treated with HK. ERp44 was significantly decreased in OSCC cell lines by HK treatment. HK directly bound to ERp44, and ERp44 knock-down significantly inhibited oral cancer cell proliferation and colony formation. Moreover, HK treatment effectively inhibited tumor growth and ERp44 levels in BALB/c nude mice bearing HN22 cell xenografts. Our findings suggest that HK inhibited inflammation and induced apoptosis by suppressing both iNOS/NO and ERp44 expression in HN22 and HSC4 cells and xenograft tumors, and thus could be a potent anti-inflammatory and anti-cancer drug candidate for human oral cancer treatment.
本研究旨在通过调节诱导型一氧化氮合酶（iNOS）和内质网驻留蛋白 44（ERp44），研究厚朴酚（HK）在两种口腔鳞状癌细胞系（OSCC）HN22 和 HSC4 中的抗炎和抗癌作用。通过格里斯测定法、酶谱法和定量 PCR 研究 OSCC 细胞系中 iNOS 的表达及随后的一氧化氮（NO）产生。采用基于液相色谱-串联质谱（LC-MS/MS）的蛋白质组学分析方法阐明与 ER 应激和 HK 诱导的细胞毒性反应相关的蛋白质。进行下拉测定和分子建模，以更好地理解 HK 如何与 ERp44 相互作用。进行体外和体内实验，敲低 ERp44 表达，以更好地理解 ERp44 在细胞水平上的作用以及 HK 的抗癌作用。HK 处理后 OSCC 细胞系中 iNOS 的表达水平和随后的 NO 分泌减少。HK 处理后 OSCC 细胞系中 ERp44 明显减少。HK 直接与 ERp44 结合，ERp44 敲低显著抑制口腔癌细胞的增殖和集落形成。此外，HK 处理有效抑制了 BALB/c 裸鼠携带 HN22 细胞异种移植瘤的肿瘤生长和 ERp44 水平。我们的研究结果表明，HK 通过抑制 HN22 和 HSC4 细胞及异种移植瘤中的 iNOS/NO 和 ERp44 表达来抑制炎症和诱导细胞凋亡，因此可能是治疗人类口腔癌的一种有效的抗炎和抗癌药物候选物。
