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Study for a tumor suppressive serpin, maspin in cervical cancer

宫颈癌中抑癌性丝氨酸蛋白酶抑制剂（maspin）的研究

基本信息

批准号：
20591949
负责人：
NAWATA Shugo
金额：
$ 3万
依托单位：
Yamaguchi University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2008
资助国家：
日本
起止时间：
2008 至 2010
项目状态：
已结题

项目摘要

Our series of recent study has demonstrated that there is a distinct difference between normal and malignant uterine cervical squamous epithelial tissues in the molecular heterogeneity of the tumor-related serine proteinase inhibitor (serpin), Squamous Cell Carcinoma (SCC) antigen. On the other hand, although maspin, identified as a 42-kDa unique tumor suppressive serpin in breast cancer, has multifaceted biological functions by interacting with various target molecules under physiological and pathological conditions including tumor progression, oxidative stress and so on, it is unknown what post-translational modification contributes the specific binding affinity of maspin to target molecules, such as glutathione S-transferase (GST). The aim of this study is therefore to analyze the molecular heterogeneity of maspin and identify its modification in MCF-10A cell, which is known to express abundant maspin protein, using various electrophoretic analyses. We successfully identified the novel form of endogenous maspin generated by intramolecular disulfide-bonded linkage under oxidative stress. Furthermore, glutathione beads pull-down assay revealed that intramolecular disulfide-bonded maspin lost the binding activity with endogenous GST, indicating that intramolecular disulfide-bonded maspin might have some distinct properties under oxidative stress, although the precise biological significance of this modification remains elusive. The western blot analysis using cervical primary cancer tissues showed that maspin expression levels in cervical cancer patients with pelvic lymph node metastasis were relative low compared to those with no pelvic lymph node metastases, suggesting that the suppression or post-translational modification of the tumor suppressive serpin, maspin might be related to tumor progression in cervical cancer.

我们最近的一系列研究表明，在正常和恶性子宫颈鳞状上皮组织中，肿瘤相关丝氨酸蛋白酶抑制剂（serpin），鳞状细胞癌（SCC）抗原的分子异质性存在明显差异。另一方面，虽然maspin被鉴定为乳腺癌中42-kDa的独特肿瘤抑制性丝氨酸蛋白酶抑制剂，在包括肿瘤进展、氧化应激等的生理和病理条件下通过与各种靶分子相互作用而具有多方面的生物学功能，但尚不清楚是什么翻译后修饰促成了maspin与靶分子的特异性结合亲和力，如谷胱甘肽S-转移酶（GST）。因此，本研究的目的是分析maspin的分子异质性，并确定其在MCF-10A细胞，这是已知的表达丰富的maspin蛋白的修饰，使用各种电泳分析。我们成功地确定了新形式的内源性maspin产生的分子内二硫键连接在氧化应激。此外，谷胱甘肽珠下拉实验显示，分子内二硫键结合maspin失去了与内源性GST的结合活性，表明分子内二硫键结合maspin可能有一些独特的性质下氧化应激，虽然这种修饰的精确的生物学意义仍然难以捉摸。宫颈癌原发灶组织蛋白质印迹分析显示，有盆腔淋巴结转移的宫颈癌患者maspin的表达水平较无盆腔淋巴结转移的宫颈癌患者低，提示肿瘤抑制蛋白serpin maspin的抑制或翻译后修饰可能与宫颈癌的进展有关。