Role of HSulf-1 Loss in Apoptosis and Drug Resistance

HSulf-1 缺失在细胞凋亡和耐药性中的作用

• 批准号: 6860142
• 负责人: VIJI SHRIDHAR
• 金额: $ 24.19万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-03-01 至 2008-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6860142
• 关键词: apoptosis; biological signal transduction; cell proliferation; chemosensitizing agent; clinical research; doxorubicin; drug resistance; enzyme mechanism; epidermal growth factor; fibroblast growth factor; gemcitabine; gene expression; genetic regulation; human subject; immunocytochemistry; laboratory mouse; ovary neoplasms; paclitaxel; patient oriented research; polymerase chain reaction; protein structure function; sulfatases; sulfotransferase; topotecan

DESCRIPTION (provided by applicant): In an effort to identify early genetic changes involved in the development of ovarian cancer, we constructed suppression subtraction hybridization (SSH) cDNA libraries from two early and two late stage ovarian tumors subtracted against normal ovarian epithelial cell brushings to identify aberrantly regulated genes in these tissues. These analyses led to the identification of HSulf-1, which encodes a novel 871 amino acid polypeptide containing a highly conserved sulfatase domain, as a gene that is downregulated in (75% of ovarian cancers. Similar downregulation is also observed in breast, pancreatic, renal cells and hepatocellular carcinoma lines. Additional data indicated that HSulf-1 encodes a cell surface polypeptide that exhibits sulfatase activity and diminishes the sulfation of heparin sulfate proteoglycans (HSPGs), specifically the N-acetylglucosamine residue of glycosaminoglycans. Emerging data suggesting that the sulfation state of HSPGs can influence signaling by heparin binding growth factors led us to hypothesize that HSulf-1 down-regulation modulates growth factor signaling in ovarian cancer. Consistent with this hypothesis, we observed that HSulf-1 restoration in HSulf-1-deficient ovarian cancer cells blunted signaling by fibroblast growth factor (FGF) and heparin-binding epidermal growth factor (HB-EGF). As a result, HSulf-1-transfected clones proliferated more slowly and were more sensitive to the induction of apoptosis by cisplatin and staurosporine than their HSulf-1-deficient counterparts. These observations suggest that HSulf-1 down-regulation contributes to the dysregulation of proliferation and apoptosis observed in ovarian cancer. Despite extensive surgery and systemic chemotherapy, usually with a taxane and a platinating agent, the vast majority of patients who present with disseminated (stage Ill or greater) ovarian cancer die of their disease. This observation highlights the need for improved understanding of drug resistance in ovarian cancer. To further evaluate the biological effects of HSulf-1 downregulation in ovarian cancer, we now propose to: 1) explore the mechanistic basis for the ability of HSulf-1 to modulate apoptosis; 2) determine the genetic basis of HSulf-1 downregulation; and 3) assess whether HSulf-1 downregulation results in resistance to other agents commonly used to treat ovarian cancer, including paclitaxel, topotecan, gemcitabine and doxorubicin, in vitro and in vivo and 4) evaluate the relationship between HSulf-1 expression and drug sensitivity in the clinical setting.

描述（由申请人提供）：为了确定卵巢癌发展中涉及的早期遗传变化，我们从两个早期和两个后期卵巢肿瘤中构建了抑制减法杂交（SSH）cDNA库，这些cDNA培养基因对正常的卵巢上皮细胞的缩减而减去，以鉴定这些组织中的异常调节基因。这些分析导致HSULF-1的鉴定，该基因编码包含高度保守的硫酸酶结构域的新型871氨基酸多肽，作为一种下调的基因（75％的卵巢癌。相似的下调。在乳腺癌，扁桃体，肾小球，肾细胞和HEPATORPORALURALURALURALURALUAL CARD FARCORBORDATID DATOD DATOD DATOD DATOD DATOD DATACORD DATOD DATOD DATOD DATOD DATOD DATOD DATOD DATOD DATOD DATOD DATOD DATOD DATOD DATOD DATOD DATOD DATOD DATOD DATOD DATOD DATOD DATOD DATOD。表现出硫酸盐活性并减少硫酸肝素蛋白聚糖（HSPG）的多肽，特别是N-乙酰葡萄糖的N-乙酰葡萄糖残基，糖胺聚糖的糖胺残基会影响HSPG的硫酸硫酸盐的硫酸盐，以降低HSPG的硫酸脉络性。卵巢癌中的生长因子信号与这一假设一致，我们观察到HSULF-1缺乏HSULF-1缺陷型卵巢癌细胞通过成纤维细胞生长因子（FGF）和肝素结合的表皮生长因子（HB-EGF）钝化了信号。结果，HSULF-1转染的克隆的增殖速度较慢，并且比其HSULF-1缺陷对应物对顺铂和星状孢菌素的诱导更敏感。这些观察结果表明，HSULF-1下调有助于在卵巢癌中观察到的增殖和凋亡失调。尽管经过广泛的手术和全身化疗，通常是紫杉烷和铂剂，但绝大多数患有卵巢癌的患者的绝大多数患者死于其疾病。该观察结果凸显了需要提高对卵巢癌耐药性的了解。为了进一步评估HSULF-1下调在卵巢癌中的生物学作用，我们现在建议：1）探索HSULF-1调节细胞凋亡的能力的机械基础； 2）确定HSULF-1下调的遗传基础； 3）评估HSULF-1下调是否会导致对治疗卵巢癌的其他药物的耐药性，包括紫杉醇，拓扑替克，吉西他滨和阿霉素，体外和体内和4）评估HSULF-1表达与临床环境中HSULF-1表达和药物敏感性之间的关系。