血清 Dickkopf-1水平与非小细胞肺癌骨转移的临床关系

在恶性肿瘤骨转移疾病中,非小细胞肺癌（NSCLC）骨转移是最常见的原因之一,其他为多发性浆细胞瘤、乳腺癌和前列腺癌。DKK（Dickkopf）-1是细胞增殖分化 Wnt 通道调控抑制基因 DKK 编码的糖蛋白之一。初步研究显示 DKK-1基因异常与多发性浆细胞瘤、乳腺癌和前列腺癌骨转移之间关系密切［1-5］。为进一步探讨 DKK-1基因异常在 NSCLC 骨转移过程中的作用,2011年6月—2014年5月课题组应用酶联免疫吸附试验（ELISA）定量检测了 NSCLC 骨转移患者血清 DKK-1浓度,并与 NSCLC 非骨部位转移患者及正常成人血清 DKK-1浓度进行对比研究,以明确 DKK-1基因异常与 NSCLC 骨转移的临床关系。     

膀胱癌患者血清DKK-1和DKK-3表达及其临床意义

目的:研究血清Dickko pf(DKK)-1和DKK-3蛋白在膀胱癌患者术前、术后及正常人中的表达情况,并进一步探讨其与膀胱癌临床病理特征之间的关系。方法:应用ELISA法检测40例膀胱癌患者术前及术后外周血清中DKK-1和DKK-3的表达情况,并与20例非肿瘤对照组患者相比较。相关性分析DKK-1和DKK-3水平之间的相关性,以及与患者临床病理特征的关系。结果:膀胱癌患者术前血清中DKK-1浓度明显高于术后及对照组患者;血清DKK-3浓度在膀胱癌患者术前和术后无明显改变,但术前、术后血清DKK-3浓度均明显低于对照组。DKK-1浓度与膀胱癌患者的临床病理特征不相关,DKK-3在高级别尿路上皮癌中的表达明显高于低级别尿路上皮癌。另外,DKK-1和DKK-3表达之间无相关性。结论:血清DKK-1和DKK-3水平与膀胱癌的发生关系密切,其中DKK-1有可能成为一种新的肿瘤标志物,而DKK-3下调可能参与了膀胱癌的浸润及转移。提示测定两蛋白表达可能有助于膀胱癌的诊断和术后预测。     

食管鳞癌患者血清DKK-1的检测及其临床意义

目的 检测食管癌患者血清中DKK-1(dickkopf-1)的表达水平,探讨其在食管癌辅助诊断中的价值.方法 应用酶联免疫吸附法(ELISA)检测80例食管鳞癌患者和35例健康对照组血清中DKK-1的浓度,计算DKK-1诊断食管鳞癌的敏感性、特异性、阳性预测值和阴性预测值,并与细胞角蛋白19片段(CYFRA21-1)和癌胚抗原(CEA)的检测做比较,探讨其在食管癌辅助诊断中的价值.结果 ①食管鳞癌患者血清中DICK-1浓度为90.44±57.41 ng/ml,而正常对照组为11.29±9.45 ng/ml,两者差异有统计学意义(P<0.01).②以正常人血清DKK-1浓度95%可信区间上限(14.54 ng/ml)为界值,则食管鳞癌患者血清中DICK-1的敏感性为66.25%(53/80);正常人血清中的DICK-1阳性率仅为17.14%(6/35),两者差异有统计学意义(P<0.01).③食管鳞癌患者血清中DKK-1的阳性率与肿瘤大小、分化程度无关(P>0.05),而与肿瘤分期和淋巴结转移密切相关(P<0.05).④3种肿瘤标记物检测比较分析显示,在诊断食管癌时,DKK-1的敏感性为66.25%,与CEA(39.44%)和CYFRA21-1(25.35%)间差异有统计学意义(P<0.05).结论 DKK-1在食管癌的发生、生长和转移过程中起着极其重要的作用,有可能成为一种新的肿瘤标记物用于食管癌的辅助诊断.     

Dickkopf-1与肿瘤

Dickkopf-1(DKK-1)通过Wnt/β-连环蛋白(β-catenin)经典信号传导途径以及Wnt非经典信号传导途径在体内诱导多种肿瘤细胞凋亡,调控多种肿瘤细胞的骨转移以及促进某些肿瘤细胞的浸润和侵袭,从而在肿瘤的发生和发展方面发挥重要作用.     

Dickkopf（DKK-1）在骨肉瘤组织中的表达及临床意义

目的研究DKK-1在骨肉瘤中的表达情况,探讨其与临床病理及预后的关系。方法S-P免疫组织化学染色法对74例骨肉瘤DKK-1蛋白的表达进行检测,并对其与骨肉瘤临床病理及预后的关系进行统计学分析。结果74例骨肉瘤标本中58例为阳性,总阳性率为78．4％（58／74）。DKK-1的表达在不同年龄、性别、骨肉瘤亚型中无显著性差异。Enneking分期Ⅰ—ⅡA与ⅡB—Ⅲ之间,肿瘤DKK-1表达率有显著性差异（P〈0．05）。结论DKK-1在骨肉瘤组织中有较高比例的表达,并与肿瘤的外科分期密切相关。     

骨肿瘤,骨转移癌患者免疫状态与临床意义

骨肿瘤、骨转移癌患者免疫状态与临床意义林建华张文明朱维钦杨滨机体的免疫状态与肿瘤的发生、发展及预后密切相关已为许多研究所证明。但历年来有关骨肿瘤、骨转移癌患者免疫功能变化的研究文献尚少报告道。我们对６８例肿瘤、骨转移癌患者外周血中Ｔ淋巴细胞亚群（ＰＴ...     

恶性肿瘤骨转移机制研究进展

恶性肿瘤骨转移的发生包括肿瘤细胞的特性、骨骼微环境及两者之间的相互作用.溶骨和成骨是两种不同的病理类型,其发生机制各不相同.骨损害与肿瘤生长密切相关.     

Wnt信号通路拮抗因子DKK-3在肿瘤中的研究进展

Wnt信号通路在肿瘤细胞的增殖、分化及发生中发挥了重要作用,其异常激活是许多肿瘤的重要特征。作为分泌性Wnt信号通路的拮抗因子Dickkopf相关蛋白-3（DKK-3）,深入研究其生物学功能以及抑制Wnt信号通路的机制,对肿瘤诊断、治疗及预后具有重要意义。本文就DKK-3的生物学作用,参与肿瘤不同阶段的发展,以及DKK-3表达／DKK-3启动子甲基化作为肿瘤生物标志物和分子靶点的潜在临床价值作一简要综述。     

mTOR通路在肿瘤骨转移中的作用

[摘要] 超过25%的实体瘤患者在晚期都会出现不同程度的骨转移。发生骨转移的肿瘤细胞与骨微环境内细胞相互作用,骨稳态被打破,建立起促进肿瘤生长、加速骨质破坏的恶性循环,进一步促进肿瘤细胞在骨髓腔中浸润,导致转移的级联反应。肿瘤骨转移是一个复杂的过程,大量分子和信号通路参与其中。研究证实,哺乳动物雷帕霉素靶蛋白（mammalian target of rapamycin,mTOR）信号通路活性的改变与肿瘤细胞的骨转移以及转移后骨质破坏密切相关。本文从肿瘤细胞的脱落、迁移、黏附和侵入等转移步骤以及骨代谢变化两方面对mTOR信号通路在肿瘤骨转移过程中的作用进行阐述,为肿瘤骨转移的预防和治疗提供新的方向。     

早期食管癌患者外周血DKK-1、CEA、CYFRA21-1和NSE的检测及临床意义

目的:探讨血清分泌型蛋白Dikkopf1(DKK-1)、癌胚抗原(carcino-embryonic antigen,CEA)、细胞角蛋白19片段(cytokeratin 19 fragment antigen 21-1,CYFRA21-1)和神经元特异性烯醇化酶(neuron-specific enolization enzyme,NSE)在早期食管癌诊断中的应用价值.方法:食管癌 (Ⅰ-Ⅱ期)患者41例及同期健康体检者32例,采用电化学发光免疫分析仪检测血清CEA、CYFRA21-1和NSE的含量,改良双抗体夹心酶联免疫吸附法检测DKK-1含量.结果:食管癌患者血清DKK-1、CEA、CYFRA21-1和NSE含量均明显高于对照组的健康体检者(均P<0.05);食管癌患者外周血DKK-1、CEA、CYFRA21-1和NSE含量均随肿瘤分期升高而升高,呈正相关;四项指标联合检测可使食管癌的诊断敏感性与特异性分别达到90.2%和95.1%.结论:外周血DKK-1、CEA、CYFRA21-1和NSE联合检测能明显提高食管癌的诊断敏感性与特异性,利于Ⅰ-Ⅱ期食管癌的诊断与治疗.     

Prostate cancer cells promote osteoblastic bone metastases through Wnts

Prostate cancer produces painful osteoblastic bone metastases. Although prostate cancer cells produce numerous osteogenic factors, to date, none have been shown to mediate osteoblastic bone metastases in an in vivo model of prostate cancer. Wnts are a large family of proteins that promote bone growth. Wnt activity is antagonized by endogenous proteins including dickkopf-1 (DKK-1). We explored if prostate cancer cells mediate osteoblastic activity through Wnts using DKK-1 as a tool to modify Wnt activity. A variety of Wnt mRNAs were found to be expressed in prostate cancer cell lines and Wnt mRNA expression was increased in primary prostate cancer compared with nonneoplastic prostate tissue. In addition to expressing Wnts, PC-3 prostate cancer cells expressed the Wnt inhibitor DKK-1. To determine if DKK-1 masked Wnt-mediated osteoblastic activity in osteolytic PC-3 cells, the cells were stably transfected with DKK-1 short hairpin RNA. Decreasing DKK-1 enabled PC-3 cells to induce osteoblastic activity, including alkaline phosphatase production and mineralization, in murine bone marrow stromal cells indicating that DKK-1 blocked Wnt-mediated osteoblastic activity in PC-3 cells. Another prostate cancer cell line, C4-2B, induces mixed osteoblastic/osteolytic lesions. To determine if Wnts contribute to C4-2B's ability to induce mixed osteoblastic/osteolytic lesions, C4-2B cells were stably transfected with either empty vector or DKK-1 expression vector to block Wnt activity. The cells were then injected in the tibiae of mice and allowed to grow for 12 weeks. Blocking Wnt activity converted the C4-2B cells to a highly osteolytic tumor. Taken together, these data show that Wnts contribute to the mechanism through which prostate cancer induces osteoblastic activity.     

The role of Wnts in bone metastases

Wnts are a large family of secreted glycoproteins that mediate bone development in the embryo and promote bone production in the adult. Autocrine Wnt signaling within tumor cells has been shown to promote tumorigenesis by enhancing tumor cell proliferation and survival. We recently demonstrated that prostate cancer cells (CaP) produce Wnts which act in a paracrine fashion to induce osteoblastic activity in CaP bone metastases. The ability of tumor-derived Wnts to influence bone development is regulated by multiple families of secreted antagonists including soluble frizzled related receptors (sFrp) and dickkopfs (DKK). CaP cells appear to produce DKK-1 early in the development of skeletal metastases, which masks osteogenic Wnts and thus favors an osteolytic environment at the metastatic site. As the metastases progresses, DKK-1 expression is lost allowing for a Wnt mediated osteoblastic response which predominates CaP boney lesions. Interestingly, blocking DKK-1 expression early in CaP metastasis prevents tumor establishment within the bone suggesting that osteolysis is a required first step in the development of CaP bone metastases. In this review, we discuss our data on the Wnt inhibitor DKK-1 in CaP bone metastasis in the context of current literature evidence that demonstrate that Wnt inhibitors can function as both tumor suppressors and tumor promoters. We provide a model that the affect of Wnt inhibitors on tumor development is dependent on the tumor micro-environment and suggest that DKK-1 is a switch which transitions CaP bone metastases from osteolytic to osteoblastic.     

p21CIP-1/WAF-1 induction is required to inhibit prostate cancer growth elicited by deficient expression of the Wnt inhibitor Dickkopf-1

Osteoblastic bone metastases are the most common metastases produced by human prostate cancers (PCa). Deregulated activity of Wnt growth factors resulting from overexpression of the Wnt inhibitor Dickkopf-1 (DKK-1) is known to contribute to formation of the osteoblastic component of PCa skeletal bone metastases. In this study, we report that DKK-1 knockdown in osteolytic human PCa cells unexpectedly delays the development of both soft tissue and osseous lesions. PCa cells deficient in DKK-1 expression did not increase canonical Wnt signaling in target osteoblast cell lines; however, DKK-1 knockdown PCa cells exhibited increased expression of the CDK inhibitor p21(CIP1/WAF1) and a 32% increase in G(1) arrest compared with control cells. Ablating p21(CIP1/WAF1) in PCa cells deficient in DKK-1 was sufficient to rescue tumor growth. Collectively, our findings demonstrate that DKK-1 overexpression supports tumor growth in part by restricting expression of p21(CIP1/WAF1) through a mechanism independent of canonical Wnt signaling.     

Prostate cancer induces bone metastasis through Wnt-induced bone morphogenetic protein-dependent and independent mechanisms

Prostate cancer (PCa) is frequently accompanied by osteosclerotic (i.e., excessive bone production) bone metastases. Although bone morphogenetic proteins (BMP) and Wnts are mediators of PCa-induced osteoblastic activity, the relation between them in PCa bone metastases is unknown. The goal of this study was to define this relationship. Wnt3a and Wnt5a administration or knockdown of DKK-1, a Wnt inhibitor, induced BMP-4 and 6 expression and promoter activation in PCa cells. DKK-1 blocked Wnt activation of the BMP promoters. Transfection of C4-2B cells with axin, an inhibitor of canonical Wnt signaling, blocked Wnt3a but not Wnt5a induction of the BMP promoters. In contrast, Jnk inhibitor I blocked Wnt5a but not Wnt3a induction of the BMP promoters. Wnt3a, Wnt5a, and conditioned medium (CM) from C4-2B or LuCaP23.1 cells induced osteoblast differentiation in vitro. The addition of DKK-1 and Noggin, a BMP inhibitor, to CM diminished PCa CM-induced osteoblast differentiation in a synergistic fashion. However, pretreatment of PCa cells with DKK-1 before collecting CM blocked osteoblast differentiation, whereas pretreatment with Noggin only partially reduced osteoblast differentiation, and pretreatment with both DKK-1 and Noggin had no greater effect than pretreatment with DKK-1 alone. Additionally, knockdown of BMP expression in C4-2B cells inhibited Wnt-induced osteoblastic activity. These results show that PCa promotes osteoblast differentiation through canonical and noncanonical Wnt signaling pathways that stimulate both BMP-dependent and BMP-independent osteoblast differentiation. These results show a clear link between Wnts and BMPs in PCa-induced osteoblast differentiation and provide novel targets, including the noncanonical Wnt pathway, for therapy of PCa.     

Dickkopf-1 is regulated by the mevalonate pathway in breast cancer

Introduction

Amino-bisphosphonates and statins inhibit the mevalonate pathway, and may exert anti-tumor effects. The Wnt inhibitor dickkopf-1 (DKK-1) promotes osteolytic bone lesions by inhibiting osteoblast functions and has been implicated as an adverse marker in multiple cancers. We assessed the effects of mevalonate pathway inhibition on DKK-1 expression in osteotropic breast cancer.

Methods

Regulation of DKK-1 by bisphosphonates and statins was assessed in human breast cancer cell lines, and the role of the mevalonate pathway and downstream targets was analyzed. Moreover, the potential of breast cancer cells to modulate osteoblastogenesis via DKK-1 was studied in mC2C12 cells. Clinical relevance was validated by analyzing DKK-1 expression in the tissue and serum of women with breast cancer exposed to bisphosphonates.

Results

DKK-1 was highly expressed in receptor-negative breast cancer cell lines. Patients with receptor-negative tumors displayed elevated levels of DKK-1 at the tissue and serum level compared to healthy controls. Zoledronic acid and atorvastatin potently suppressed DKK-1 in vitro by inhibiting geranylgeranylation of CDC42 and Rho. Regulation of DKK-1 was strongest in osteolytic breast cancer cell lines with abundant DKK-1 expression. Suppression of DKK-1 inhibited the ability of breast cancer cells to block WNT3A-induced production of alkaline phosphates and bone-protective osteoprotegerin in preosteoblastic C2C12 cells. In line with the in vitro data, treatment of breast cancer patients with zoledronic acid decreased DKK-1 levels by a mean of 60% after 12 months of treatment.

Conclusion

DKK-1 is a novel target of the mevalonate pathway that is suppressed by zoledronic acid and atorvastatin in breast cancer.     

Dickkopf-1 Levels in Turkish Patients with Bladder Cancer and its Association with Clinicopathological Features

Background: Evidence indicates that Dickkopf-1 (DKK-1) levels may be a biomarker for cancer risk. Theaim of this study was to assess DKK-1 and its correlation with clinic-pathological features in patients withbladder cancer. Materials and Methods: DKK-1 levels were determined in serum samples from 90 patients withbladder cancer before transurethral tumor resection. The concentrations of DKK-1 were determined by usingenzyme linked immune-sorbent assay (ELISA). Results: Elevated preoperative DKK-1 levels were associatedwith tumor stage (p<0.001), grade (p<0.001) and histological grade (p<0.001). Conclusions: The results of ourstudy demonstrated that the level of serum DKK-1 is correlated with both disease progression and increase inthe tumor grade. Preoperative serum DKK-1 elevation may thus represent a novel marker for the determinationof bladder cancer and the detection of patients with a likely poor clinical outcome.     

Serum concentrations of Dickkopf-1 protein are increased in patients with multiple myeloma and reduced after autologous stem cell transplantation

Dickkopf-1 (DKK-1) protein, a soluble inhibitor of Wnt signalling, has been implicated in the pathogenesis of myeloma bone disease through the suppression of osteoblast differentiation. In this study, serum concentrations of DKK-1 were measured in 50 myeloma patients (32 at diagnosis and 18 before and after autologous stem cell transplantation (ASCT), 18 patients with monoclonal gammopathy of undetermined significance (MGUS), and 22 healthy controls. Serum DKK-1 levels were increased in MM at diagnosis compared with MGUS (mean +/- SD: 67 +/- 54 ng/mL vs. 38 +/- 13 ng/mL; p = 0.006) and controls (31 +/- 11 ng/mL; p = 0.02), while there was no difference between MGUS patients and controls. Although patients with stage 2 and 3 myeloma had higher DKK-1 values than stage 1 patients (79 +/- 63 vs. 40 +/- 13; p = 0.005), no significant correlation between serum DKK-1 and myeloma bone disease was observed. Myeloma patients before ASCT also had increased levels of DKK-1 (63 +/- 77 ng/mL; p = 0.03) compared with controls, supporting the notion that DKK-1 may be responsible for the suppressed osteoblast activity even in patients with low tumor burden. After ASCT, there was a sustained decrease in DKK-1 levels over time, while bone formation markers elevated, suggesting that the reduction of DKK-1 levels after ASCT may correlate with the normalization of osteoblast function. These results could provide the basis for developing agents that block DKK-1, thus restoring osteoblast function and counteracting the increased osteoclastogenesis observed in myeloma.     

Increased Dickkopf-1 expression in breast cancer bone metastases

The aim of this study was to determine whether Dickkopf-1 (Dkk-1) expression in breast cancer was associated with bone metastases. We first analysed Dkk-1 expression by human breast cancer cell lines that induce osteolytic or osteoblastic lesions in animals. Dickkopf-1 levels were then measured in the bone marrow aspirates of hind limbs from eight NMRI mice inoculated with breast cancer cells that induced bone metastases and 11 age-matched non-inoculated control animals. Finally, Dkk-1 was measured in the serum of 17 women with breast cancer in complete remission, 19 women with breast cancer and bone metastases, 16 women with breast cancer and metastases at non-bone sites and 16 healthy women. Only breast cancer cells that induce osteolytic lesions in animals produced Dkk-1. There was a six-fold increase in Dkk-1 levels in the bone marrow from animals inoculated with MDA-B02 cells when compared with that of control non-inoculated animals (P=0.003). Median Dkk-1 levels in the serum of patients with breast cancer and bone metastases were significantly higher than levels of patients in complete remission (P=0.016), patients with breast cancer having metastases at non-bone sites (P<0.0001) and healthy women (P=0.047), although there was a large overlap in individual levels between the different groups. In conclusion, Dkk-1 is secreted by osteolytic human breast cancer cells lines and increased circulating levels are associated with the presence of bone metastases in patients with breast cancer. Measurements of circulating Dkk-1 levels may be useful for the clinical investigation of patients with breast cancer and bone metastases.