Arctigenin Enhances Chemosensitivity to Cisplatin in Human Nonsmall Lung Cancer H460 Cells through Downregulation of Survivin Expression

Arctigenin, a dibenzylbutyrolactone lignan, enhances cisplatin‐mediated cell apoptosis in cancer cells. Here, we sought to investigate the effects of arctigenin on cisplatin‐treated non‐small‐cell lung cancer (NSCLC) H460 cells. The 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay and annexin‐V/propidium iodide staining were performed to analyze the proliferation and apoptosis of H460 cells. Arctigenin dose‐dependently suppressed cell proliferation and potentiated cell apoptosis, coupled with increased cleavage of caspase‐3 and poly(ADP‐ribose) polymerase. Moreover, arctigenin sensitized H460 cells to cisplatin‐induced proliferation inhibition and apoptosis. Arctigenin alone or in combination with cisplatin had a significantly lower amount of survivin. Ectopic expression of survivin decreased cell apoptosis induced by arctigenin (P < 0.05) or in combination with cisplatin (P < 0.01). Moreover, arctigenin (P < 0.05) or in combination with cisplatin (P < 0.01) induced G1/G0 cell‐cycle arrest. Our data provide evidence that arctigenin has a therapeutic potential in combina‐tion with chemotherapeutic agents for NSLC.     

抑制 Livin 基因对肺腺癌 SPC-A1 细胞增殖及顺铂敏感性的影响

目的:Livin是近年来发现的人类凋亡抑制蛋白(inhibitorof apoptosis protein,IAP)家族的新成员,发现在多数肿瘤中表达,与肿瘤发生有密切关系,并可能作为肿瘤诱导凋亡治疗的新靶点。本研究旨在探讨si RNA-Livin和夫拉平度(Flavopiridol,FP)协同凋亡诱导配体(TRAIL)两种方式有效抑制Livin表达,诱导非小细胞肺癌SPC-A1凋亡并增强对化疗药物顺铂的敏感性。方法:si RNA-Livin转染SPC-A1,Real-Time PCR检测Livin基因的表达水平,MTT检测干扰组和干扰加药组肿瘤细胞的增殖及活性;TRAIL、FP单独及联合作用诱导细胞凋亡,蛋白质印迹法检测凋亡抑制蛋白Livin的表达水平,MTT检测各处理组细胞的增殖及活性。结果:100 nmol/LFP处理组(F)细胞存活率为(84.30±1.34)%,100 ng/m LTRAIL处理组(T)为(93.40±1.56)%,FP和TRAIL联合组(F+T)为(48.02±1.35)%,si RNA-Livin处理组为(50.88±1.14)%,1.2μg/m L Cisplatin处理组为(19.30±0.89)%,si RNA-livin+Cisplatin组为(14.37±0.81)%,FP+T+Cisplatin组为(10.86±0.87)%,C组存活率为100%。F+T组对细胞的增殖抑制作用显著高于单独用药组,si RNA-livin+Cisplatin与si RNA-Livin组相比、FP+T+Cisplatin与FP+T组相比都显著增强了化疗药物对SPC-A1的杀伤作用。50μmol/LZ-VAD-FMK预处理后联合用药组细胞的存活率为(88.16±1.64)%,caspase抑制剂能明显抑制F+T联合处理组的凋亡效应。结论:RNA干扰和F+T联合用药都能显著降低凋亡抑制蛋白Livin的表达,有效抑制肿瘤细胞的增殖生长,并增强肿瘤细胞对化疗药物顺铂的敏感性,为肺腺癌的靶向治疗提供新的理论依据。     

EGCG Enhances Cisplatin Sensitivity by Regulating Expression of the Copper and Cisplatin Influx Transporter CTR1 in Ovary Cancer

Cisplatin is one of the first-line platinum-based chemotherapeutic agents for treatment of many types of cancer, including ovary cancer. CTR1 (copper transporter 1), a transmembrane solute carrier transporter, has previously been shown to increase the cellular uptake and sensitivity of cisplatin. It is hypothesized that increased CTR1 expression would enhance the sensitivity of cancer cells to cisplatin (cDDP). The present study demonstrates for the first time that (-)-epigallocatechin-3-gallate (EGCG), a major polyphenol from green tea, can enhance CTR1 mRNA and protein expression in ovarian cancer cells and xenograft mice. EGCG inhibits the rapid degradation of CTR1 induced by cDDP. The combination of EGCG and cDDP increases the accumulation of cDDP and DNA-Pt adducts, and subsequently enhances the sensitivity of ovarian cancer SKOV3 and OVCAR3 cells to the chemotherapeutic agent. In the OVCAR3 ovarian cancer xenograft nude mice model, the combination of the lower concentration of cDDP and EGCG strongly repressed the tumor growth and exhibited protective effect on the nephrotoxicity induced by cisplatin. Overall, these findings uncover a novel chemotherapy mechanism of EGCG as an adjuvant for the treatment of ovarian cancer.     

MicroRNA-203 Is a Prognostic Indicator in Bladder Cancer and Enhances Chemosensitivity to Cisplatin via Apoptosis by Targeting Bcl-w and Survivin

Resistance to cisplatin-based chemotherapy is a major cause of treatment failure in advanced bladder cancer (BC) patients. There is increasing evidence that microRNAs are involved in the development and progression of BC. However, little is known about the function of microRNAs in predicting the effect of adjuvant chemotherapy on BC survival and regulating response to cisplatin. To address this issue, we employed RT-qPCR to evaluate the clinical significance of miR-203 expression in 108 tissues of BC patients receiving cisplatin-based adjuvant chemotherapy, and performed in vitro studies to explore chemotherapeutic sensitivity to cisplatin in miR-203 overexpressing BC cells. We found miR-203 levels were significantly lower in BC progression group than non-progression group (P<0.001). ROC curve analysis illustrated miR-203 could significantly distinguish progressed patients from those without progression (P<0.001), yielding an area under the ROC curve of 0.839 (95% CI, 0.756–0.903). Moreover, low miR-203 expression correlated with shortened progression free survival (PFS) and overall survival (OS) of BC patients, and was an independent prognostic factor. Overexpression of miR-203 in 5637 and T24 BC cells could decrease cell viability, enhance cisplatin cytotoxicity, and promote apoptosis. Western blotting and luciferase reporter assay showed Bcl-w and Survivin were direct downstream targets of miR-203. There was also a significant inverse association between miR-203 and Bcl-w or Survivin expression in BC tissues (r = -0.781, -0.740, both P<0.001). In conclusion, decreased miR-203 predicts progression and poor prognosis for BC patients treated with cisplatin-based chemotherapy while miR-203 overexpression can enhance cisplatin sensitization by promoting apoptosis via directly targeting Bcl-w and Survivin.     

IgG Expression in Human Colorectal Cancer and Its Relationship to Cancer Cell Behaviors

Increasing evidence indicates that various cancer cell types are capable of producing IgG. The exact function of cancer-derived IgG has, however, not been elucidated. Here we demonstrated the expression of IgG genes with V(D)J recombination in 80 cases of colorectal cancers, 4 colon cancer cell lines and a tumor bearing immune deficient mouse model. IgG expression was associated with tumor differentiation, pTNM stage, lymph node involvement and inflammatory infiltration and positively correlated with the expressions of Cyclin D1, NF-κB and PCNA. Furthermore, we investigated the effect of cancer-derived IgG on the malignant behaviors of colorectal cancer cells and showed that blockage of IgG resulted in increased apoptosis and negatively affected the potential for anchor-independent colony formation and cancer cell invasion. These findings suggest that IgG synthesized by colorectal cancer cells is involved in the development and growth of colorectal cancer and blockage of IgG may be a potential therapy in treating this cancer.     

miR-451a促进胰腺癌细胞对吉西他滨的敏感性

目的:探究miR-451a在胰腺癌吉西他滨耐药中的功能。方法:通过低浓度梯度递增法建立胰腺癌吉西他滨耐药细胞株,microRNA(miRNA)测序筛选耐药相关miRNA;细胞存活曲线、克隆形成实验及流式凋亡实验分析miR-451a对胰腺癌细胞耐药的影响;裸鼠成瘤实验检测在动物体内模型中miR-451a对胰腺癌吉西他滨耐药的调控作用;调取TCGA数据分析miR-451a表达水平与胰腺癌病人预后的相关性。结果:胰腺癌吉西他滨耐药细胞株中miR-451a表达水平明显下调;miR-451a过表达增加胰腺癌细胞对吉西他滨的敏感性,增强了吉西他滨抑制细胞增殖和诱导细胞凋亡的作用;miR-451a诱导了裸鼠皮下肿瘤对吉西他滨敏感;miR-451a低表达与胰腺癌患者不良预后相关。结论:miR-451a增强了胰腺癌细胞对吉西他滨的敏感性。     

人野生型p53基因增强5-FU对大肠癌化疗敏感性的分子生物学机制

为了探讨人野生型p53（wt-p53）基因增强大肠癌细胞化疗敏感性的分子生物学机制,将携带wt p53基因的质粒分别转染两种p53基因突变的人大肠癌细胞系HT-29及SW620,分析细胞中p53及细胞周期蛋白D1（cyclin D1）蛋白的表达水平;将化疗药物5 氟尿嘧啶（5-fluorouracil,5-FU）以不同浓度、不同时间分别作用于HT-29及SW620细胞,另外将已转染wt-p53基因的大肠癌细胞用5-FU进行诱导,Western印迹分析上述干预条件下细胞中p53蛋白及细胞周期蛋白D1表达水平的变化;流式细胞术检测wt p53基因联合5-FU组及对照组中细胞凋亡的改变情况.结果表明,wt-p53基因能增加癌细胞中细胞周期蛋白D1的表达,与wt-p53基因呈剂量依赖性关系;5-FU则降低其蛋白表达,与5-FU呈时间和剂量依赖性关系,而5-FU所致的细胞周期蛋白D1表达水平的降低在细胞预先转染了wt- p53基因时会被抑制;wt-p53基因与5-FU联合使用能提高大肠癌细胞凋亡率.结果提示,wt-p53基因可提高大肠癌细胞中细胞周期蛋白D1的表达水平,并抑制5-FU所致的细胞周期蛋白D1降解,从而提高大肠癌细胞对化疗药物5-FU的敏感性.     

Modulating the Distant Spreading of Patient-Derived Colorectal Cancer Cells via Aspirin and Metformin

Although screening has reduced mortality rates for colorectal cancer (CRC), about 20% of patients still carry metastases at diagnosis. Postsurgery chemotherapy is toxic and induces drug resistance. Promising alternative strategies rely on repurposing drugs such as aspirin (ASA) and metformin (MET). Here, tumor spheroids were generated in suspension by primary CRCs and metastatic lymph nodes from 11 patients. These spheroids presented a heterogeneous cell population including a small core of CD133⁺/ESA⁺ cancer stem cells surrounded by a thick corona of CDX2⁺/CK20⁺ CRC cells, thus maintaining the molecular hallmarks of the tumor source. Spheroids were exposed to ASA and/or MET at different doses for up to 7 days to assess cell growth, migration, and adhesion in three-dimensional assays. While ASA at 5 mM was always sufficient to mitigate cell migration, the response to MET was patient specific. Only in MET-sensitive spheroids, the 5 mM ASA/MET combination showed an effect. Interestingly, CRCs from diabetic patients daily pretreated with MET gave a very low spheroid yield due to reduced cancer cell survival. This study highlights the potential of ASA/MET treatments to modulate CRC spreading.     

Wee1 Inhibition by MK-1775 Leads to Tumor Inhibition and Enhances Efficacy of Gemcitabine in Human Sarcomas

Sarcomas are rare and heterogeneous mesenchymal tumors affecting both pediatric and adult populations with more than 70 recognized histologies. Doxorubicin and ifosfamide have been the main course of therapy for treatment of sarcomas; however, the response rate to these therapies is about 10–20% in metastatic setting. Toxicity with the drug combination is high, response rates remain low, and improvement in overall survival, especially in the metastatic disease, remains negligible and new agents are needed. Wee1 is a critical component of the G2/M cell cycle checkpoint control and mediates cell cycle arrest by regulating the phosphorylation of CDC2. Inhibition of Wee1 by MK1775 has been reported to enhance the cytotoxic effect of DNA damaging agents in different types of carcinomas. In this study we investigated the therapeutic efficacy of MK1775 in various sarcoma cell lines, patient-derived tumor explants ex vivo and in vivo both alone and in combination with gemcitabine, which is frequently used in the treatment of sarcomas. Our data demonstrate that MK1775 treatment as a single agent at clinically relevant concentrations leads to unscheduled entry into mitosis and initiation of apoptotic cell death in all sarcomas tested. Additionally, MK1775 significantly enhances the cytotoxic effect of gemcitabine in sarcoma cells lines with different p53 mutational status. In patient-derived bone and soft tissue sarcoma samples we showed that MK1775 alone and in combination with gemcitabine causes significant apoptotic cell death. Magnetic resonance imaging (MRI) and histopathologic studies showed that MK1775 induces significant cell death and terminal differentiation in a patient-derived xenograft mouse model of osteosarcoma in vivo. Our results together with the high safety profile of MK1775 strongly suggest that this drug can be used as a potential therapeutic agent in the treatment of both adult as well as pediatric sarcoma patients.     

Reduction of Orc6 Expression Sensitizes Human Colon Cancer Cells to 5-Fluorouracil and Cisplatin

Previous studies from our group have shown that the expression levels of Orc6 were highly elevated in colorectal cancer patient specimens and the induction of Orc6 was associated with 5-fluorouracil (5-FU) treatment. The goal of this study was to investigate the molecular and cellular impact of Orc6 in colon cancer. In this study, we use HCT116 (wt-p53) and HCT116 (null-p53) colon cancer cell lines as a model system to investigate the impact of Orc6 on cell proliferation, chemosensitivity and pathways involved with Orc6. We demonstrated that the down regulation of Orc6 sensitizes colon cancer cells to both 5-FU and cisplatin (cis-pt) treatment. Decreased Orc6 expression in HCT-116 (wt-p53) cells by RNA interference triggered cell cycle arrest at G1 phase. Prolonged inhibition of Orc6 expression resulted in multinucleated cells in HCT-116 (wt-p53) cell line. Western immunoblot analysis showed that down regulation of Orc6 induced p21 expression in HCT-116 (wt-p53) cells. The induction of p21 was mediated by increased level of phosphorylated p53 at ser-15. By contrast, there is no elevated expression of p21 in HCT-116 (null-p53) cells. Orc6 down regulation also increased the expression of DNA damaging repair protein GADD45β and reduced the expression level of JNK1. Orc6 may be a potential novel target for future anti cancer therapeutic development in colon cancer.     

人类抑癌基因beclin 1在胃癌和直结肠癌中表达下调的研究

人类抑癌基因beclin 1通过自噬作用调节细胞生长,但在胃癌和直结肠癌中其表达水平和调控机制仍不清楚．通过检测胃癌和直结肠肿瘤组织中beclin 1基因的表达水平,及DNA异常甲基化和杂合子缺失对其表达的影响,发现与癌旁组织相比,35％的胃癌标本和30％的直结肠癌标本中beclin 1基因表达显著下调．同时发现,beclin 1基因5’端存在一高密度CpG岛,在胃癌和直结肠癌中beclin 1的启动子区域和第二个内含子区域存在甲基化,而杂合子缺失仅在胃癌中发生．这些发现表明beclin 1基因的异常甲基化和杂合子缺失对其在胃癌和直结肠癌中的表达起调控作用．     

Combination Treatment with the GSK-3 Inhibitor 9-ING-41 and CCNU Cures Orthotopic Chemoresistant Glioblastoma in Patient-Derived Xenograft Models

Resistance to chemotherapy remains a major challenge in the treatment of human glioblastoma (GBM). Glycogen synthase kinase-3β (GSK-3β), a positive regulator of NF-κB–mediated survival and chemoresistance of cancer cells, has been identified as a potential therapeutic target in human GBM. Our objective was to determine the antitumor effect of GSK-3 inhibitor 9-ING-41 in combination with chemotherapy in patient-derived xenograft (PDX) models of human GBM. We utilized chemoresistant PDX models of GBM, GBM6 and GBM12, to study the effect of 9-ING-41 used alone and in combination with chemotherapy on tumor progression and survival. GBM6 and GBM12 were transfected by reporter constructs to enable bioluminescence imaging, which was used to stage animals prior to treatment and to follow intracranial GBM tumor growth. Immunohistochemical staining, apoptosis assay, and immunoblotting were used to assess the expression of GSK-3β and the effects of treatment in these models. We found that 9-ING-41 significantly enhanced 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) antitumor activity in staged orthotopic GBM12 (no response to CCNU) and GBM6 (partial response to CCNU) PDX models, as indicated by a decrease in tumor bioluminescence in mouse brain and a significant increase in overall survival. Treatment with the combination of CCNU and 9-ING-41 resulted in histologically confirmed cures in these studies. Our results demonstrate that the GSK-3 inhibitor 9-ING-41, a clinical candidate currently in Investigational New Drug (IND)-enabling development, significantly enhances the efficacy of CCNU therapy for human GBM and warrants consideration for clinical evaluation in this difficult-to-treat patient population.