Inhibitory effect of midkine-binding peptide on tumor proliferation and migration

Background: To investigate the inhibitory effect of midkine-binding peptides on human umbilical vein endothelial cells (HUVECs) proliferation and angiogenesis of xenograft tumor. Methods: The midkine-binding peptides were panned by Ph.D.-7^™ Phage Display Peptide Library Kit, and the specific binding activities of positive clones to target protein were examined by phage ELISA. The effect of midkine-binding peptides on proliferation of HUVECs was confirmed by MTT test. The xenograft tumor model was formed in BALB/c mice with the murine hepatocarcinoma cells H22 (H22). Microvessel density (MVD) was analyzed by immunohistochemistry of factor VIII staining. Results: Midkine-binding peptides have the inhibitory effects on tumor angiogenesis, a proliferation assay using human umbilical vein endothelial cells (HUVECs) indicated that particular midkine-binding peptides significantly inhibited the proliferation of the HUVECs. Midkine-binding peptides were also observed to efficiently suppress angiogenesis induced by murine hepatocarcinoma H22 cells in BALB/c nude mice. Conclusion: The midkine-binding peptides can inhibit solid tumor growth by retarding the formation of new blood vessels. The results indicate that midkine-binding peptides may represent potent anti-angiogenesis agents in vivo.     

剪切波弹性成像参数联合血清中期因子、胸苷激酶1、促甲状腺素与甲状腺球蛋白比值鉴别诊断 甲状腺结节的临床价值

目的 探讨剪切波弹性成像（SWE）参数联合血清中期因子（MK）、胸苷激酶1(TK1)、促甲状腺素与甲状腺球蛋白比值（TSH/Tg）鉴别诊断甲状腺结节良恶性的临床价值。方法 选取我院经术后病理结果或穿刺结果证实的甲状腺结节患者129例,均为单发病灶,其中良性组98例,恶性组31例,均行SWE检查及血清MK、TK1、TSH、Tg检测,比较两组SWE参数[杨氏模量最小值（Emin）、最大值（Emax）、平均值（Emean）],以及血清MK、TK1、TSH/Tg的差异。应用Logistic回归分析建立SWE参数联合血清MK、TK1、TSH/Tg的诊断模型;绘制受试者工作特征（ROC）曲线分析该模型鉴别甲状腺结节良恶性的诊断效能。结果 与良性组比较,恶性组Emax、Emin、Emean及血清MK、TK1、TSH/Tg均升高,差异均有统计学意义（均P<0.05）。应用Logistic回归分析建立SWE参数联合血清MK、TK1、TSH/Tg的诊断模型为：Logit(P)=-0.069+0.101×Emean+0.353×血清MK+0.328×血清TK1+0.882×血清TSH/Tg;ROC曲线...     

中期因子蛋白表达与子宫内膜腺癌进展的关系

目的 探讨中期因子(midkine MK)蛋白在子宫内膜腺癌中的表达和进展的关系.方法 采用免疫组织化学:EnVision法检测72例子宫内膜腺癌组织、15例子宫内膜非典型增生和20例正常子宫内膜组织中MK蛋白的表达情况,并结合患者临床及病理资料进行分析.结果 子宫内膜腺癌、子宫内膜非典型增生、正常子宫内膜组织中MK蛋白阳性表达率分别为63.9﹪、33.3﹪、15.0﹪,子宫内膜腺癌中MK蛋白阳性率明显高于子宫内膜非典型增生(P＜0.01)和正常子宫内膜(P＜0.01).随着肌层浸润深度、TNM分期的增加,MK蛋白的阳性率显著上升(P＜0.01、P＜0.05);有淋巴结转移组MK阳性率明显高于无淋巴结转移组(P＜0.05);MK蛋白阳性的患者总的生存率低于阴性者(P＜0.05).结论 MK蛋白在子宫内膜腺癌恶性进程中表达上调,有望成为子宫内膜腺癌恶性度评估和判断预后的有价值指标.     

Midkine is highly expressed in neuroblastoma tissues

Purpose  Neuroblastoma (NBL) is a tumor from neural crest cells, and is the most frequent solid tumor in children. Midkine (MK) is a pleiotropin analogon, which is frequently expressed in neuronal and epithelial tumors and is a marker for a poor clinical outcome. The aims of this study were to assess MK expression in NBL and investigate the correlation with clinical outcome. Methods  Fifty-six specimens of NBL were stained for MK on a tissue microarray by immunohistochemistry (IHC). Fresh frozen tumor tissues were used for RNA isolation, and RT-PCR analysis for MK-mRNA expression was performed. Survival data, risk factors and disease stages were correlated with MK status assessed by IHC and RT-PCR analysis. Results  MK-mRNA expression was found in the majority of the tumor tissues (75%), whereas MK protein could be detected only in 46% of the NBL by IHC. No correlation of MK status with survival, risk factors or disease stage was observed. Conclusion  A majority of NBL express MK-mRNA, whereas not all MK mRNA positive tumors showed also a positive MK IHC staining. The high expression of MK-mRNA expression might present a promising target for new adenovirus-based gene therapeutic approaches for the treatment of NBL.     

In vitro and in vivo suppression of hepatocellular carcinoma growth by midkine-antisense oligonucleotide-loaded nanoparticles

AIM： To synthesize antisense oligonucleotides （ASODNs） of midkine （MK）, package the ASODNs with nanoparticles, and to inhibit hepatocellular carcinoma （HCC） growth using these nanoparticles. METHODS： HepG2 cell proliferation was analyzed in vitro using the 3-（4,5-dimethythiazol-2-yl）-5- （3-carboxymethoxyphenyl）-2-（4-sulfophenyl）- 2Htetrazolium, inner salt assay. The in vivo activity of nanoparticles delivering the MK-ASODNs was analyzed by histopathological and immunohistochemical staining and quantitative real time polymerase chain reaction （PCR）. RESULTS： The in vitro proliferation of HepG2 cells was significantly inhibited by the nanoparticles packaged with MK-ASODNs （NANO-ASODNs）. Furthermore, the NANOASODNs significantly inhibited the growth of HCC in the mouse model. CONCLUSION： NANO-ASODNs can significantly suppress the growth of HCC in vitro and in vivo.     

Midkine positively regulates the proliferation of human gastric cancer cells

Midkine (MDK), a heparin-binding growth factor, modulates the proliferation and migration of various cells, is often highly expressed in many malignant tumors, and may act as an oncoprotein. We found that MDK is overexpressed in clinical human gastric cancer tissues relative to its expression in adjacent noncancerous tissues. To further investigate the biological activities of MDK in gastric cancer, we introduced the MDK gene into human SGC7901 gastric cancer cells, where it contributed to the proliferation of SGC7901 cells in vitro and in vivo. Conversely, the knockdown of MDK expression by siRNA resulted in significantly reduced proliferation of BGC823 cells. Our study also shows that MDK activates both the Akt and ERK1/2 pathways and upregulates the expression of several cell-cycle-related proteins, including cyclin A, cyclin D1, Cdk2, Cdk4, and Cdk6, which in part explains the contribution of MDK to gastric cancer cell survival and growth. These results demonstrate that MDK contributes to gastric cancer cell proliferation and suggest that it plays an important role in the development of human gastric cancer.     

血清MK和Th17/调节性T细胞对类风湿关节炎患者病情发生发展的影响

目的 观察Th17/调节性T细胞(Treg)免疫失衡在类风湿关节炎(RA)患者发病时的作用,探讨血清中期因子(MK)和Th17/调节性T细胞(Treg)对RA患者病情发生发展的影响.方法 选取2013年3月至2016年1月在攀枝花市第二人民医院接受治疗的RA患者58例,根据RA是否处于活动期,将26例DAS28≤3.2者纳入非活动组,32例DAS28>3.2纳入活动组,另将30例健康者作为对照组,采用酶联免疫吸附法对三组受检者的血清MK、白介素-17(IL-17)、白介素-6(IL-6)、白介素-23(IL-23)水平进行检测,利用流式细胞术检测调节性T细胞和外周血Th17细胞的比例变化,并对其比例变化和血清MK、IL-17、IL-6、IL-23的水平进行比较.结果 活动组患者的Th17、调节性T细胞比例分别为(1.90±1.00)%、(1.58±1.03)%,非活动组分别为(0.98±0.36)%、(3.92±1.29)%,对照组分别为(0.57±0.21)%、(8.01±1.44)%,活动组血清MK为(342.36±68.39)pg/mL,非活动组为(257.91±56.79)pg/mL,对照组为(200.14±83.42)pg/mL,活动组血清MK及Th17、调节性T细胞比例分别与非活动组比较,差异均具有统计学意义(P<0.05),活动组与非活动组的血清MK及Th17、调节性T细胞比例分别与对照组比较,差异均具有统计学意义(P<0.05).活动组IL-17、IL-6和IL-23分别为(28.74±4.37)ng/L、(12.84±2.38)ng/L、(74.27±11.74)ng/L,非活动组分别为(19.25±3.27)ng/L、(9.36±2.74)ng/L、(52.29±13.83)ng/L,对照组分别为(6.01±3.28)ng/L、(5.99±2.92)ng/L、(27.37±10.27)ng/L,活动组与非活动组的IL-17、IL-6和IL-23水平分别与对照组比较,差异均具有统计学意义(P<0.05).结论 RA患者的血清MK上升,且类风湿性关节炎患者Th17/Treg平衡中Th17相对增高,而Treg会相对降低,MK的上升和Th17/Treg平衡失调都促进了RA的发生发展.     

宫颈鳞癌中MK蛋白的表达与肿瘤血管新生的相关性研究

目的:探讨宫颈鳞癌组织中MK蛋白的表达及其与肿瘤血管新生的关系,为宫颈鳞癌的化学防治提供实验依据.方法:采用免疫组织化学S-P法检测58例宫颈鳞癌和10例正常宫颈上皮组织中MK蛋白的表达,并对其微血管(CD34标记)计数.结果:宫颈鳞癌组织中MK蛋白的表达及微血管密度(MVD)均明显高于正常宫颈上皮组织(P＜0.01),MK蛋白的高表达与宫颈鳞癌病灶的大小及临床分期相关性显著(P=0.045;P=0.002),与患者年龄、肿瘤分化程度及淋巴结转移无明显相关;MK蛋白表达阳性者微血管密度明显高于阴性者,二者正相关(P=0.043).结论:MK蛋白过表达可能参与了宫颈鳞癌的发生发展,并与宫颈鳞癌的血管新生密切相关,可作为宫颈鳞癌化学防治的一个新靶点.     

中期因子对大鼠心肌梗死后心室重塑的保护作用

目的观察中期因子（MK）对大鼠急性心肌梗死（AMI）后心室重塑的影响。方法成年雄性Wistar大鼠48只,随机分为4组：空白对照组（Control组）、伪手术组（sham组）、梗死模型组（AMI组）和MK干预组（MK组）。结扎大鼠左冠状动脉前降支（LAD）,建立AMI动物模型。模型制备成功后,在环绕LAD周围注射MK为MK干预组。4周后,对大鼠行血流动力学指标检测,称重,计算全心体重指数;取组织制备标本,Masson染色鉴定胶原生成情况;免疫组化检测心肌微血管;TUNEL检测细胞凋亡数;Westernblot分析左心室内Bel-2蛋白、P—ERK1蛋白含量的表达。结果MK组大鼠心功能较AMI组得到明显的改善（P〈0．05）;全心体重指数较AMI组明显降低（3．788±0．630比4．725±0．610,P〈0．05）。sham组与Control组几乎无胶原形成,而AMI组与MK组有明显的胶原组织。在梗死及梗死周边区微血管数目MK组多于AMI组（30．662±1．794比15．275±0．389,P〈0．05）,心肌细胞凋亡率明显低于AMI组（27．2±3．2比47．8±4．5,P〈0．05）。MK组Bcl-2蛋白表达较AMI组增多（1．8748±1．0406比1．3637±0．2528,P〈0．05）,P—ERK1蛋白表达较AMI组增多（1．2751±0．6353比0．7862±0．5470,P〈0．05）。结论MK对大鼠心梗后心室重塑产生保护作用,其机制可能与MK上调了P—ERK1蛋白表达有关。     

Midkine expression in colorectal tumors: correlation with Ki-67 labeling in sporadic, but not ulcerative colitis-associated ones

Midkine (MK) is a heparin-binding growth factor encoded by a retinoic acid responsive gene. To investigate the possible contribution of MK to genesis of colorectal carcinomas, an immunohistochemical examination of protein expression was conducted in sporadic and ulcerative colitis (UC)-associated tumors. MK expression significantly differed among normal mucosa, adenomas with low-grade dysplasia (LGD), adenomas with high-grade dysplasia (HGD) and invasive adenocarcinomas: MK expression was increased along with tumor progression. UC-associated lesions (regenerative mucosa of UC, UC-associated dysplasia and UC-associated adenocarcinoma) had similar variations. MK expression in UC-associated lesions was significantly higher than in normal mucosa, although there was no significant difference among UC-associated lesions. However, in UC-associated dysplasia, MK expression did not differ between the upper and lower halves, in contrast to adenoma with LGD and HGD, in which MK expression was significantly higher in the upper than lower halves, corresponding to cell proliferative zone. Furthermore, correlations with Ki-67 and single-strand DNA labeling, respectively, reflecting cellular proliferative activity and apoptosis, were noted in sporadic but not UC-associated lesions. These results suggest that MK is involved in genesis/development of sporadic colorectal tumors as well as of UC-associated tumors, but might contribute differently to genesis/development in these two types of tumors.