二甲双胍抗肿瘤作用及其分子机制的研究进展

二甲双胍是全球范围内治疗2型糖尿病最常用的药物之一,具有使用方便、疗效好、价格低廉且毒副作用小等优点。近年来大量的流行病学研究及体内外实验研究发现二甲双胍能够用于多种肿瘤的治疗及预防,然而其分子机制尚不十分明确;主要包括调节体内胰岛素/IGF-1轴、激活AMPK信号通路、调控micro RNAs的表达、活化Caspase分子、阻断AGEs-RAGE系统等,这些机制为将来二甲双胍应用于肿瘤的预防及临床治疗提供了重要的理论依据。本文针对糖尿病治疗药物二甲双胍在抗肿瘤中的作用及其分子机制进行全面综述。     

二甲双胍对胶质母细胞瘤细胞的抑制作用研究

为了探究二甲双胍对不同胶质母细胞瘤U87细胞、GL261细胞及C6细胞增殖的影响,选取小鼠GBM细胞GL261细胞系、大鼠GBM细胞C6细胞系及人源GBM细胞U87MG细胞系,使用二甲双胍处理,通过CCK-8法检测细胞增殖活性;细胞实时荧光检测细胞凋亡水平;平板克隆实验检测GBM细胞克隆形成能力;CCK-L法检测胞内ATP水平;Western blot检测Akt及其磷酸化水平。结果显示,与对照组相比,随着作用浓度增加,二甲双胍显著抑制GBM细胞增殖活性,影响细胞形态;与对照组相比,同一作用浓度下,二甲双胍提高了GBM细胞凋亡水平,抑制了GBM细胞克隆形成能力,降低了GBM胞内ATP的产生;二甲双胍处理24 h后,GBM细胞内p-Akt表达显著下调,Akt无明显变化。结果表明,二甲双胍在体外可抑制多种GBM细胞的增殖、克隆,降低胞内ATP水平,其机制可能与Akt磷酸化水平相关,研究结果为进一步探索二甲双胍对胶质母细胞瘤的作用机制提供了体外研究理论基础。     

二甲双胍抗肿瘤效应的基础与临床研究进展

二甲双胍(Metformin)是一种胰岛素增敏剂,临床上主要用于2型糖尿病的治疗。越来越多的证据表明,二甲双胍能够发挥抗肿瘤效应,它通过活化磷酸腺苷蛋白激酶(AMPK),阻断哺乳动物雷帕霉素靶蛋白(m TOR)信号通路抑制肿瘤细胞的生长,并且参与细胞周期、凋亡、血管新生等多种生物学行为。不仅如此,二甲双胍的抗肿瘤临床研究也不断出现,包括大样本回顾性研究和前瞻性研究。这些研究数据不仅为二甲双胍抗肿瘤效应提供了有益的证据支持,也为二甲双胍及其介导的抗肿瘤分子信号途径的阐明奠定了理论依据。     

运动与二甲双胍调节肝脏脂代谢的作用机制研究进展

肝脏脂代谢紊乱与2型糖尿病、肥胖症、心血管疾病等多种慢性病密切相关。运动与二甲双胍均可通过作用于不同组织器官调节机体脂代谢,是防治脂代谢异常相关疾病的有效手段。运动可减少肝脏脂质摄入与分泌、降低脂质合成、促进脂肪酸分解,二甲双胍可抑制肝脏糖异生及脂质合成,达到控糖减脂的作用。两者在激活AMPK信号通路、促进肝脏因子分泌方面表现为协同效应,而对线粒体复合物I活性的调节却表现为拮抗效应,两者联合作用于肝脏脂代谢的分子机制有待进一步研究。该文基于运动与二甲双胍调控肝脏脂代谢的生物学机制进行综述,为慢病预防和治疗提供新的思路与策略。     

依那普利与二甲双胍联合治疗肥胖性高血压的临床观察

目的：肥胖与高血压的发生、发展密切相关,肥胖人群更容易发生高血压,而目前我国肥胖和高血压的发生率大幅上升,至今仍无针对肥胖性高血压的指南。研究表明,二甲双胍有改善代谢以外的降压作用,ACEI有降压以外的改善代谢作用。本研究的目的为观察二甲双胍联合依那普利对肥胖性高血压患者血压、体重指数（BMI）、腰围及血脂的影响效果。方法：76例诊断为肥胖性高血压的患者随机分成观察组和对照组,观察组38例患者给予二甲双胍＋依那普利治疗;对照组38例患者给予依那普利治疗,观察期为24周,并于治疗前及治疗24周后测定血脂（TG、TC,HDL—C、LDL-C）、BMI、腰围（WC）变化。每2周门诊随访并记录血压。结果：①经24周治疗后,两组患者血压（MDBP、MSBP）均明显降低,P〈0．05,且二甲双胍＋依那普利观察组的降压作用明显优于依那普利对照组（P〈O．05）;②观察组的体重指数（BMI）、腰围（WX）、血脂水平（TC、TG、HDL-C、LDL-C）较治疗前显著下降（P〈O．05）,而对照组较治疗前无明显变化（P〉0．05）。结论：二甲双胍＋依那普利对肥胖性高血压患者不仅具有良好的降压效果作用而且能降低BMI,WC及血脂水平。是肥胖性高血压较理想的治疗方案。     

依那普利与二甲双胍联合治疗肥胖性高血压的临床观察

目的:肥胖与高血压的发生、发展密切相关,肥胖人群更容易发生高血压,而目前我国肥胖和高血压的发生率大幅上升,至今仍无针对肥胖性高血压的指南。研究表明,二甲双胍有改善代谢以外的降压作用,ACEI有降压以外的改善代谢作用。本研究的目的为观察二甲双胍联合依那普利对肥胖性高血压患者血压、体重指数(BMI)、腰围及血脂的影响效果。方法:76例诊断为肥胖性高血压的患者随机分成观察组和对照组,观察组38例患者给予二甲双胍+依那普利治疗;对照组38例患者给予依那普利治疗,观察期为24周,并于治疗前及治疗24周后测定血脂(TG、TC、HDL-C、LDL-C)、BMI、腰围(WC)变化。每2周门诊随访并记录血压。结果:①经24周治疗后,两组患者血压(MDBP、MSBP)均明显降低,P<0.05,且二甲双胍+依那普利观察组的降压作用明显优于依那普利对照组(P<0.05);②观察组的体重指数(BMI)、腰围(WC)、血脂水平(TC、TG、HDL-C、LDL-C)较治疗前显著下降(P<0.05),而对照组较治疗前无明显变化(P>0.05)。结论:二甲双胍+依那普利对肥胖性高血压患者不仅具有良好的降压效果作用而且能降低BMI,WC及血脂水平。是肥胖性高血压较理想的治疗方案。     

二甲双胍在肿瘤治疗中的机制研究进展

作为胰岛素增敏剂的降糖药物二甲双胍具有抗肿瘤的多种生物活性,它能够抑制肿瘤细胞的增殖、促进凋亡、增强肿瘤对化疗药物的敏感性、并且能逆转部分肿瘤细胞对化疗药物的耐药性、甚至还能抑制肿瘤新生血管的生成.这些生物功能的实现依赖于AMPK等相关的信号通路的活化,进而负向调控mTOR通路信号分子的表达,再通过转录因子的表达调控相关靶基因的表达.因此这些信号分子的活化或抑制就成为了新的抗肿瘤治疗的靶点.肿瘤干细胞也是近年来研究的一个热点,二甲双胍能直接杀伤某些肿瘤的干细胞,从而达到有效抑瘤的作用.但二甲双胍杀伤肿瘤干细胞的分子机制不明确.另外.二甲双胍联合激素药物治疗肿瘤,可以增加保守治疗的效果.虽然二甲双胍具有显著的抗肿瘤的多重功效,但其具体的分子机制尚未被清晰完整的阐明,有待进一步的研究和证实.     

二甲双胍调控肠道菌群并抑制结直肠癌的生长

目的 探究二甲双胍抑制肠癌的生长及调控肠道菌群的作用。 方法 20只C57BL/6J小鼠通过AOM DSS诱导结直肠癌发生,分成2组每天分别灌胃生理盐水及二甲双胍溶液,12周后处死小鼠,收集结直肠组织及粪便,比较2组小鼠肠道肿瘤个数及大小并进行H&E染色分析,运用16S rRNA基因测序技术检测小鼠肠道菌群组成,使用QIIME软件分析菌群物种分类、物种多样性指数及组间显著性差异。 结果 2组小鼠体质量随周龄增加均呈现增长趋势,且实验结束时体质量差异无统计学意义(t=0.743 1,P=0.469 7)。与对照组相比,接受二甲双胍灌胃的实验组小鼠结直肠肿瘤数量减少(t=2.260 0,P=0.040 3)且尺寸偏小(t=2.570 0,P=0.014 4)。粪便菌群测序结果显示实验组小鼠肠道菌群丰富度增加(P0.05)。在属水平上,实验组Akkermansia、Ruminococcus及Clostridium Ⅹa和Ⅳ等细菌的丰富度增加。 结论 二甲双胍能够调控肠道菌群的组成,增加肠道内产SCFAs细菌的定植,并抑制肠癌的发生发展。     

二甲双胍对T2D患者肠道菌群的影响

2型糖尿病是一种由环境和遗传因素共同导致的以高血糖为主的慢性代谢性疾病,其主要的特点是胰岛素分泌不足和胰岛素抵抗。目前2型糖尿病发病率正在快速上升,给我们的未来带来了严峻的挑战。宿主肠道内正常的肠道菌群参与宿主的营养代谢、生长发育等重要生理功能,而研究表明肠道菌群失调与2型糖尿病密切相关。二甲双胍由于廉价、安全、有效成为了目前应用最广泛的降糖药之一,它不仅可以通过依赖及非依赖AMPK途径降糖,越来越多的研究表明它还可以通过改善T2D患者失调的肠道菌群发挥降糖作用。明确二甲双胍对肠道菌群的影响,有助于全面了解二甲双胍的作用机制。     

二甲双胍调控糖尿病大鼠骨髓间充质干细胞的增殖和分化

虽然二甲双胍广泛用于治疗2型糖尿病,但是其对骨骼的潜在影响知之甚少。因此,本研究评估了二甲双胍对培养的大鼠骨髓间充质干细胞(MSCs)和脂肪细胞两者的分化以及增殖的影响。首先随机组形成对照实验,其中对照组为在不经二甲双胍处理培养基中培养MSCs细胞21 d,而二甲双胍组则在用100μmol/L二甲双胍处理培养基中培养MSCs 21 d。结果表明,二甲双胍增强了大鼠MSCs的成骨细胞分化细胞中ALP的活性,抑制了培养中MSCs脂肪形成分化的过程,但是增强了MSCs细胞的增殖能力。     

Establishment and characterization of a new human hepatocellular carcinoma cell line

Summary A human hepatocellular carcinoma cell line (FOCUS—Friendship of China and United States) was derived from a patient with primary hepatocellular carcinoma. This cell line has been in continuous culture over an 18-mo period. The morphological and ultrastructural features of FOCUS are consistent with its neoplastic hepatocellular orgin. FOCUS cells contain aspartate aminotransferase and glucose-6-phosphatase activity. In addition, α₁-antitrypsin, fibrinogen, alpha fetoprotein, and carcinoembryonic antigens were detectble in the cytoplasm of the cultured cells by immunochemical staining techniques. The karyotype of the FOCUS cell is human in origin and it contains human DNA sequences as detected by molecular hybridization analysis. The FOCUS cells do not show evidence of density-dependent inhibition of growth under confluent conditions. Repeated growth curves over an 18-mo period were identical, revealing a doubling time of 42 to 48 h. The malignant potential of FOCUS cells was further demonstrated by their ability to lead to gross tumor formation after subcutaneous infection into nude mice. From one of the solid tumors grown in nude mice, recultured cell lines have been established and found to have properties identical to the original FOCUS cell line. This FOCUS cell line represents an additional model for further investigation of tumor specific antigens and the relationship between hepatitis B virus (HBV) and hepatocellular carcinoma. Preliminary molecular characterization has indicated the existence of integrated HBV sequences within the FOCUS genome.     

Role of toll-like receptors gene polymorphism in hepatocellular carcinoma

Abstract

Toll-like receptors (TLRs), evolutionarily conserved innate, play important roles in the development of autoimmunity. TLRs proteins are localized on the cell surface or in endosomes and play critical roles in innate immune responses against different pathogens. Aberrant stimulation of the innate immune system through intracellular TLRs may lead to hyperactive immune responses and contribute to the pathogenesis of hepatocellular carcinoma (HCC). HCC is the seventh most common cancer and the third leading cause of cancer deaths worldwide, and innate immune takes a most important role in HCC. There was no review to sum up the role of TLRs gene polymorphism in HCC. This review was performed to sum up the role of TLRs gene polymorphism in HCC.     

Slug promoted vasculogenic mimicry in hepatocellular carcinoma

Vasculogenic mimicry (VM) refers to the unique capability of aggressive tumour cells to mimic the pattern of embryonic vasculogenic networks. Epithelial–mesenchymal transition (EMT) regulator slug have been implicated in the tumour invasion and metastasis of human hepatocellular carcinoma (HCC). However, the relationship between slug and VM formation is not clear. In the study, we demonstrated that slug expression was associated with EMT and cancer stem cell (CSCs) phenotype in HCC patients. Importantly, slug showed statistically correlation with VM formation. We consistently demonstrated that an overexpression of slug in HCC cells significantly increased CSCs subpopulation that was obvious by the increased clone forming efficiency in soft agar and by flowcytometry analysis. Meantime, the VM formation and VM mediator overexpression were also induced by slug induction. Finally, slug overexpression lead to the maintenance of CSCs phenotype and VM formation was demonstrated in vivo. Therefore, the results of this study indicate that slug induced the increase and maintenance of CSCs subpopulation and contributed to VM formation eventually. The related molecular pathways may be used as novel therapeutic targets for the inhibition of HCC angiogenesis and metastasis.     

Gut microbiota alterations are distinct for primary colorectal cancer and hepatocellular carcinoma

Colorectal cancer(CRC)and hepatocellular carcinoma(HCC)are the second and third most common causes of death by cancer,respectively.The etiologies of the two cancers are either infectious insult or due to chronic use of alcohol,smoking,diet,obesity and diabetes.Patho-logical changes in the composition of the gut microbiota that lead to intestinal inflammation are a common factor for both HCC and CRC.However,the gut microbiota of the cancer patient evolves with disease pathogenesis in unique ways that are affected by etiologies and envi-ronmental factors.in this review,we examine the chan-ges that occur in the composition of the gut microbiota across the stages of the HCC and CRC.Based on the idea that the gut microblota are an additional"lifeline"and contribute to the tumor microenvironment,we can observe from previously published literature how the microbiota can cause a shift in the balance from normal→ inflammation → diminished inflammation from early to later disease stages.This pattern leads to the hypothesis that tumor survival depends on a less pro-inflammatory tumor microenvironment.The differences observed in the gut microbiota composition between different disease etiologies as well as between HCC and CRC suggest that the tumor microenvironment is unique for each case.     

LINC00857 contributes to hepatocellular carcinoma malignancy via enhancing epithelial-mesenchymal transition

Hepatocellular carcinoma (HCC) remains the fifth most frequent cancer with high mortality rate worldwide. However, the underlying molecular mechanisms of HCC progression are still barely known. Long noncoding RNAs (lncRNAs) have been recognized as significant therapeutic targets for HCC. Recently, the biological role of LINC00857 in several cancer types has been reported. Our present study was aimed to investigate the role of LINC00857 in HCC progression. We observed that LINC00857 was overexpressed in HCC cell lines (Huh7, Hep3B, HepG2, MHCC-97H, and SNU449). Knockdown of LINC00857 significantly repressed Hep-3B and SNU449 cell proliferation and inhibited the HCC cell colony formation. In addition, cell apoptosis was induced by the silence of LINC00857 and cell cycle progression was blocked in G1 phase. Besides these, downregulation of LINC00857 was able to restrain HCC cell migration and invasion capacity via enhancing epithelial-mesenchymal transition (EMT) process. As displayed, E-cadherin protein expression was increased by LINC00857 silence, while N-cadherin protein level was repressed by LV-shLINC00857 in HCC cells. Finally, the in vivo assays were used and the data indicated that LINC00857 could also obviously suppress the HCC tumor growth in vivo. In conclusion, our study revealed that LINC00857 might provide a novel perspective for the HCC treatment.     

The expression and significance of NET-1 and Contactin in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and a major cause of cancer-related mortality. In this study, the significance of NET and Contactin on the pathogenesis and prognosis of HCC was investigated, and further to explore their functions in vitro and in vivo by down regulation with siRNA. The expression of NET-1 and Contactin in HCC and in adjacent non-tumor tissues (ANT) were evaluated by immunohistochemistry, and the correlations of the expression of NET-1 and Contactin with the clinicopathological characteristics and survival of HCC patients were also analyzed. After inhibited by single-target siRNA or dual-target siRNA, the expressions of NET-1 and Contactin mRNA and protein in SMMC-7221 cells were determined by RT-PCR, Western blot and immunofluorescence stain. The cell proliferation and apoptosis were assessed by CCK-8 assays and flow cytometry (FCM). The ability of cell migration and invasion were evaluated by wound-healing migrating assay and transwell chamber assays, respectively. Subsequently, transmission system encapsulated cationic liposome was used to deliver dual-siRNA into HCC xenografts in mice. The expressions of NET-1, Cortactin, Ki67, Bax, Bcl2 and Survivin in xenograft tumor were detected by immunohistochemical staining, respectively. The positive rates of NET-1 and Cortactin in HCC tissues were significantly higher than those in ANT. In HCC, the expression of NET-1 was related to Edmondson''s grade (P<0.05), cirrhosis background (P<0.001) and TNM stage (P<0.05). The expression of Cortactin was related to tumor infiltration (P<0.05), vascular invasion (P <0.001) and TNM stage (P<0.001). The expressions of NET-1 and Cortactin were positively correlated (r=0.280, P=0.004). Significant differences in the 5-year survival rates were seen between the NET-1 negative group and the positive group (P<0.05), and between the Contactin negative group (50%) and Contactin positive group (28.0%, P<0.01). The 5-year overall survival rate (OS) in NET-1 and Contactin co-expression cases (27.78%) were remarkably lower than that in both NET-1 and Contactin negative cases (54.54%) and in NET-1 positive while Contactin negative cases (47.06%, P<0.05). Univariate and multivariate Cox regression analysis revealed that NET-1 and Contactin over-expression were independent indicators for OS in HCC patients (P<0.01). There were higher expressions of NET-1 and Contactin in SMMC-7721 cells than that in other HCC cells. Dual-siRNA was demonstrated to be more effective on inhibiting cancer cell proliferation, migration and inducing apoptosis than individual siRNAs used alone in vitro and in vivo (P<0.05). The results suggest that dual-siRNA may be a great potential in siRNA-based therapeutic applications.     

The landscape of DNA methylation in hepatocellular carcinoma

Better understanding of the relationship between changes in the overall methylation status of hepatocellular carcinoma (HCC) and disease progression will help us find good strategies for the early detection and treatment of HCC patients. The purpose of the study was to study the relations between the methylation status changes in HCC patients and progression of the disease to enable early detection and treatment of HCC patients. First, the DNA methylation data of 50 HCC samples and the surrounding normal samples were extracted and the change pattern of methylation status in the DNA promoter region of HCC samples against that of normal samples was studied. Then, some DNA methylation genes that could accurately identify cancer and cancer-adjacent tissues were identified using the k-top scoring pair method. Also, a prognostic signature that could predict the survival of HCC patients was constructed based on the overall survival time and death information of the early HCC patients. Finally, the obtained prognostic signature was verified. In conclusion, this study described the changes in the methylation spectrum during the development of HCC and identified genes associated with HCC progression and prognosis, which may offer new opportunities for the diagnosis and treatment of HCC.