HPV16 increases the number of migratory cancer stem cells and modulates their miRNA expression profile in oropharyngeal cancer

Human papillomavirus type 16 (HPV16) is a major risk for development of oropharyngeal squamous‐cell‐carcinoma (OPSCC). Although HPV⁺ OPSCC metastasize faster than HPV^? tumors, they have a better prognosis. The molecular and cellular alterations underlying this pathobiology of HPV⁺ OPSCC remain elusive. In this study, we examined whether expression of HPV16‐E6E7 targets the number of migratory and stationary cancer stem cells (CSC). Furthermore, we wanted to elucidate if aberrantly expressed miRNAs in migratory CSC may be responsible for progression of OPSCCs and whether they may serve as potential novel biomarkers for increased potential of metastasis. Our studies revealed that HPV16‐E6E7 expression leads to an increase in the number of stationary (CD44^high/EpCAM^high) stem cells in primary keratinocyte cultures. Most importantly, expression of E6E7 in the cell line H357 increased the migratory (CD44^high/EpCAM^low) CSC pool. This increase in migratory CSCs could also be confirmed in HPV⁺ OPSCC. Differentially expressed miRNAs from HPV16‐E6E7 positive CD44^high/EpCAM^low CSCs were validated by RT‐qPCR and in situ hybridization on HPV16⁺ OPSCCs. These experiments led to the identification of miR‐3194‐5p, which is upregulated in primary HPV16⁺ OPSCC and matched metastasis. MiR‐1281 was also found to be highly expressed in HPV⁺ and HPV^? metastasis. As inhibition of this miRNA led to a markedly reduction of CD44^high/EpCAM^low cells, it may prove to be a promising drug target. Taken together, our findings highlight the capability of HPV16 to modify the phenotype of infected stem cells and that miR‐1281 and miR3194‐5p may represent promising targets to block metastatic spread of OPSCC.     

Combined use of expression and CGH arrays pinpoints novel candidate genes in Ewing sarcoma family of tumors

Background  

Ewing sarcoma family of tumors (ESFT), characterized by t(11;22)(q24;q12), is one of the most common tumors of bone in children and young adults. In addition to EWS/FLI1 gene fusion, copy number changes are known to be significant for the underlying neoplastic development of ESFT and for patient outcome. Our genome-wide high-resolution analysis aspired to pinpoint genomic regions of highest interest and possible target genes in these areas.     

CIP2A is a candidate therapeutic target in clinically challenging prostate cancer cell populations

Residual androgen receptor (AR)-signaling and presence of cancer stem-like cells (SCs) are the two emerging paradigms for clinically challenging castration-resistant prostate cancer (CRPC). Therefore, identification of AR-target proteins that are also overexpressed in the cancer SC population would be an attractive therapeutic approach.Our analysis of over three hundred clinical samples and patient-derived prostate epithelial cultures (PPECs), revealed Cancerous inhibitor of protein phosphatase 2A (CIP2A) as one such target. CIP2A is significantly overexpressed in both hormone-naïve prostate cancer (HN-PC) and CRPC patients. CIP2A is also overexpressed, by 3- and 30-fold, in HN-PC and CRPC SCs respectively. In vivo binding of the AR to the intronic region of CIP2A and its functionality in the AR-moderate and AR-high expressing LNCaP cell-model systems is also demonstrated. Further, we show that AR positively regulates CIP2A expression, both at the mRNA and protein level. Finally, CIP2A depletion reduced cell viability and colony forming efficiency of AR-independent PPECs as well as AR-responsive LNCaP cells, in which anchorage-independent growth is also impaired.These findings identify CIP2A as a common denominator for AR-signaling and cancer SC functionality, highlighting its potential therapeutic significance in the most clinically challenging prostate pathology: castration-resistant prostate cancer.     

膀胱癌患者尿液外泌体中miRNA差异表达谱及其生物信息学分析

目的:通过检测及筛选膀胱癌患者及正常人尿液外泌体中差异性表达的miRNA,进行生物学分析,探讨miRNA在膀胱癌发病中的作用.方法:利用超高速离心法及Illumina高通量测序技术分离并检测5例膀胱癌患者及5例配对正常人尿液标本中外泌体miRNA的表达情况,构建其差异表达谱.对差异表达基因进行生物信息学分析,确定差异表...     

MAEL expression links epithelial‐mesenchymal transition and stem cell properties in colorectal cancer

MAEL plays a central role during spermatogenesis by repressing transposable elements and preventing their mobilisation, however, its role on cancers is unclear. In this study, MAEL expression was analysed in a tissue microarray containing 185 samples of primary colon cancer tumor samples and human colon cancer cell lines. The effect of MAEL on cell proliferation, tumorigenesis, metastasis and drug resistance was examined in vitro and in vivo. Immunoprecipitation assay, confocal immunofluorescent analysis and luciferase assay were used for mechanism study. As results, MAEL was significantly upregulated in colon cancer patient tissue samples, and elevated MAEL protein levels positively correlated with overall survival and disease free survival of colon cancer patients. Using in vitro and in vivo models, we demonstrated that MAEL expression was correlated with cell proliferation, invasion and drug resistance of colon cancer cells by inducing epithelial‐mesenchymal transition and stemness characteristics. Mechanistically, our study demonstrated that MAEL interacts with Snail and inhibit E‐cadherin promoter activity. Collectively, MAEL is an oncogene that plays an important role in the development and progression of colon cancer, which may be a novel potential therapeutic target for colon cancer.     

Prognostic and therapeutic relevance of HER2 expression in osteosarcoma and Ewing's sarcoma

Expression of HER2 was evaluated by immunohistochemical techniques in 84 osteosarcoma (OS) and 113 Ewing's sarcoma (ES) paraffin-embedded tumour biopsies. HER2 gene status was also assessed in a panel of cell lines as well as in vitro efficacy of trastuzumab (a humanised antibody directed against HER2) as single agent or in combination with the insulin-like growth factor I receptor (IGF-IR) IR3 antibody. Overexpression of HER2 was present in 32% of OS and 16% of ES and was significantly associated with the increased expression of P-glycoprotein, a surface molecule responsible for multidrug resistance. Event-free survival analyses revealed a prognostic value for HER2 and/or P-glycoprotein expression in OS, but not in ES. However, despite its prognostic relevance, no therapeutic effectiveness was observed pre-clinically for trastuzumab-driven therapy, in both OS or ES cell lines, unless the antibody was associated with anti-IGF-IR targeting strategies. Therefore, the therapeutic potential of trastuzumab in these neoplasms may be better exploited in combined treatments with anti-IGF-IR approaches.     

The expression of stem cell protein Piwil2 and piR-932 in breast cancer

BackgroundTo investigate the expression status of PIWIL2 and piR-932 in breast cancer stem cells and the role they could play in tumor cell growth and metastasis through Latexin.MethodsCD44⁺/CD24^? tumor cells (CSC) from clinical specimens were sorted using flow cytometry. PIWIL2 expression status was detected in CSC cells by microarray analysis and 1086 breast cancer specimens by Western blot and immunohistochemistry staining. piR-932 expression was also detected in CSC cells by piRNA microarray assay. The relationship between the PIWIL2 protein and clinico-pathological parameters and prognosis was subsequently determined.ResultsCSC cells are more likely to generate new tumors in mice and cell microspheres that are deficient in NOD/SCID compared to the control group. PIWIL2 protein was expressed higher in CSC cells compared to the control cells. In total, 334 (30.76%) of the 1086 breast cases showed high PIWIL2 expression. PIWIL2 was observed to be related to age, tumor size, histological type, tumor stage, and lymph node metastasis (all P < 0.05). Furthermore, we have found that one of the Piwi-interacting RNAs (piRNAs) called piR-932 expressed significantly higher in the breast cancer cells that were induced to EMT, and it could form immune complexes through immunoprecipitation with PIWIL2; in PIWIL2+ breast cancer stem cells, Latexin expression significantly reduced because of its promoter region CpG island methylation.ConclusionsThese results suggest that the combination of piR-932 and PIWIL2 may be a positive regulator in the process of breast cancer stem cells through promoting the methylation of Latexin, and they both could be the potential targets for blocking the metastasis of breast cancer.     

循环 miRNA 在非小细胞肺癌诊断治疗及预后判断中的价值

微小 RNA（microRNAs,miRNAs）是一类参与基因转录后水平调控的小分子非编码 RNA,广泛参与肿瘤发生发展等过程的调节。循环 miRNAs 是在外周血中发现的 miRNAs,新近研究资料显示,循环 miR-NAs 作为一种新型生物标志物可能在肺癌的诊断、疗效评估和预后判断中有着重要的作用和价值。     

表达载体的构建及对乳腺癌D2F2细胞小鼠移植瘤的治疗作用

目的：探讨靶向小鼠肝细胞再生磷酸酶-3（mouse phosphatase of regenerating liver-3, mPRL-3 ）的DNA疫苗对小鼠乳腺癌D2F2细胞体内生长的抑制作用。 方法： 构建靶向 mPRL-3 的真核表达载体pVAX1-mPRL-3,并转染至鹌鹑肌成纤维细胞QM7内,Western blotting检测mPRL-3蛋白在QM7细胞中的表达;通过重组慢病毒Lv-mPRL-3或对照载体Lv-Ctrl感染小鼠乳癌D2F2细胞,分别建立高表达 mPRL-3 的mPRL-3-D2F2细胞或对照NC-D2F2细胞,Western blotting检测小鼠乳腺癌D2F2细胞中mPRL-3蛋白的表达。BALB/c小鼠左侧乳腺脂肪垫下分别接种mPRL-3-D2F2和 NC-D2F2细胞后,通过基因枪接种pVAX1-mPRL-3疫苗（mPRL-3-D2F2/pVAX1-mPRL-3）,同时设立疫苗对照组（mPRL-3-D2F2/pVAX1-Ctrl）和细胞对照组（NC-D2F2/pVAX1-mPRL-3）,检测小鼠的肿瘤体积及生存期。 结果： pVAX1-mPRL-3质粒经酶切鉴定及测序验证均正确,并能在QM7细胞中表达。Western blotting检测结果显示,慢病毒感染的mPRL-3-D2F2细胞中mPRL-3蛋白过表达,而NC-D2F2细胞中不表达mPRL-3蛋白。荷瘤小鼠经pVAX1-mPRL-3 DNA疫苗免疫,其肿瘤体积明显低于对照组\[（835.3±509.8） vs (1 5430±578.4) mm3,P<0.01\],且pVAX1-mPRL-3疫苗能显著延长荷瘤小鼠的生存期（中位生存期55.5 vs 38 d,P<005）。 结论: 基因枪接种的靶向 mPRL-3 的DNA疫苗能抑制高表达mPRL-3的小鼠乳腺癌D2F2细胞移植瘤的生长,并延长荷瘤小鼠生存期,提示其对 mPRL-3 阳性肿瘤有潜在的治疗作用。     

Cyclooxygenase 2-dependent expression of survivin is critical for apoptosis resistance in non-small cell lung cancer

Elevated tumor cyclooxygenase 2 (COX-2) expression is associated with increased angiogenesis, tumor invasion, and promotion of tumor cell resistance to apoptosis. In our previous studies using non-small cell lung cancer (NSCLC) cell lines constitutively expressing COX-2 cDNA in sense and antisense orientations, we demonstrated that constitutive overexpression of COX-2 leads to stabilization of the inhibitor of apoptosis protein survivin resulting in the elevated apoptosis resistance of COX-2-overexpressing cells. Genetic or pharmacologic suppression of COX-2 activity increased proteasomal degradation of survivin and cellular response to apoptosis induction. Our data show that expression of survivin in non-small cell lung cancer cells can be significantly down-regulated by RNA interference. Whereas COX-2-overexpressing NSCLC cells have significantly higher apoptosis resistance than the parental cells, inhibition of survivin expression by small interfering RNA decreases apoptosis resistance to the level of the parental non-small cell lung cancer. We conclude that COX-2-dependent expression of survivin is critical for apoptosis resistance in non-small cell lung cancer.     

ABCB5 expression and cancer stem cell hypothesis in oral squamous cell carcinoma

IntroductionThe vast majority of oral cancers are squamous cell carcinomas (OSCC). The effectiveness of adjuvant cytostatic chemotherapy for OSCC is frequently restricted due to an inducible cellular mechanism called multidrug resistance (MDR) and a putative cancer stem cell (CSC) compartment in human carcinogenesis expressing multidrug efflux pumps. The novel human ATP-binding cassette (ABC) transporter ABCB5 [subfamily B (MDR/TAP) member 5] acts as an energy-dependent drug efflux transporter and marks tumour cells of a putative CSC compartment. However, to date, there is no link between ABCB5 expression and OSCC.Materials and methodsExpression of ABCB5 was analysed in OSCC specimen (n = 191) and cancer cell lines (BICR3, BICR56) by immunohistochemistry, real-time polymerase chain reaction (RT-PCR) analysis and western blotting. Scanned images were digitally analysed using ImageJ and the immunomembrane plug-in. ABCB5 expression on protein level was correlated with clinical characteristics and impact on survival. ABCB5 was co-labelled with CD44 in immunohistochemical and immunofluorescence double labelling experiments. Expression subgroups were identified by receiver operating characteristics (ROC) analysis.ResultsHigh ABCB5 expression was significantly associated with tumour progression and recurrence of the tumour. Multivariate analysis demonstrated high ABCB5 expression as an independent prognostic factor (p = 0.0004). Immunohistochemical and immunofluorescence double labelling experiments revealed ABCB5 expression by CD44+ cancer cells. ABCB5 specificity was confirmed by western blot and RT-PCR analysis.ConclusionsFor the first time, this study provides evidence that ABCB5 expression in OSCC might be associated with tumour formation, metastasis and a putative CSC compartment. One of the principal mechanisms for protecting putative cancer stem cells is through the expression of multifunctional efflux transporters from the ABC gene family, like ABCB5. This provides one mechanism in which putative cancer stem cells could survive and may lead to tumour relapse. Knowledge of expression profiles of ABC transporters and other genes involved in MDR will likely help therapeutic optimisation for cancer patients in clinic. However, this hypothesis requires further in vitro and in vivo studies.     

CDK2调控ALDH1A3介导原神经-间质转化促进胶质瘤干细胞增殖的机制研究

目的:研究细胞周期蛋白依赖性激酶2(CDK2)促进胶质瘤干细胞(GSCs)增殖和诱导原神经-间质转化的作用机制.方法:利用生物信息学方法对GSCs中CDK2的表达水平进行分析,并利用shRNA沉默CDK2的表达以探究其促进GSCs增殖的作用;建立GSCs原神经-间质转换(PMT)模型,并对CDK2介导PMT的下游靶点和机制进行预测和验证.结果:CDK2在GSCs中高表达,而特异性沉默CDK2能够显著抑制GSCs生长(P＜0.01).当GSCs接受放射处理后CDK2和ALDH1 A3表达显著上调,而CDK2沉默能够显著下调ALDH1A3的表达.E2F1是和CDK2表达关联性最高的ALDH1A3启动子区域结合蛋白,而利用shRNA沉默CDK2能够下调GSCs中E2F1和ALDH1A3的表达水平.结论:CDK2能够通过调节E2F1的表达激活ALDH1 A3的启动子活性并调控其表达和功能,进而调控GSCs的生长并诱导GSCs发生PMT.     

Gene expression profiling of cancer stem cell in human lung adenocarcinoma A549 cells

Background  

The studies on cancer-stem-cells (CSCs) have attracted so much attention in recent years as possible therapeutic implications. This study was carried out to investigate the gene expression profile of CSCs in human lung adenocarcinoma A549 cells.     

Circadian properties of cancer stem cells in glioma cell cultures and tumorspheres

Increased cancer risk is linked to disruption of circadian rhythms. Cancer stem cells (CSCs) are a known cause of cancer aggressiveness, but their circadian properties have not been described. We discovered circadian rhythms in gene expression within C6 glioma tumorspheres enriched in CSCs and found that the circadian clock is particularly robust in medium lacking any growth factors. A method is introduced for identifying individual CSCs in culture for single-cell analysis. CSCs in monolayer cell culture failed to show a circadian rhythm in nuclear localization of mPER2 protein, suggesting that cell interactions or the tumor-like microenvironment within tumorspheres enable circadian timing.     

rAAV-2-hGM-CSF、rAAV-2mGM-CSF转导骨髓间充质干细胞的在体基因表达

目的 观察经rAAV-2-hGM-CSF、rAAV-2-mGM-CSF基因转导修饰的骨髓间充质干细胞在体基因表达情况.方法 按预先摸索好的转染条件在体外用rAAV-2-hGM-CSF、rAAV-2-mGM-CSF感染骨髓间充质干细胞后,继续在体外扩增培养12 d,再将被基因修饰的骨髓间充质干细胞通过尾静脉回输到6周龄的裸鼠体内,对照组回输未经基因转导处理的骨髓间充质干细胞,分别于此后的2、4、6、8周处死裸鼠,取其外周血,计数白细胞总数,检测血清中hGM-CSF、mGM-CSF的含量.结果 回输前hGM-CSF、mGM-CSF的分泌水平为36.25、25.14 ng/L,回输后2、4、6、8周裸鼠血清中hGM-CSF的含量分别为23.77、26.32、19.77、15.25 ng/L,mGM-CSF的含量分别为34.96、34.84、35.50、32.93 ng/L,相应时间点对照组裸鼠血清中mGM-CSF的水平分别为17.34、17.44、14.68、16.85 ng/L.rAAV-2-mGM-CSF转导组可使裸鼠体内白细胞计数增加,而rAAV-2-hGM-CSF转导组和对照组裸鼠体内的白细胞计数却无变化.结论 骨髓间充质干细胞可作为一种基因治疗的载体细胞,携带在体外经过基因修饰了的治疗基因在体内发挥其治疗作用.     

Caspase expression profile and functional activity in a panel of breast cancer cell lines

Caspases play an essential role in the initiation/regulation of apoptosis. Aberrant apoptotic regulation has been associated with carcinogenesis and therapeutic resistance. To explore the possible involvement of altered caspase expression in breast cancer, we have systematically examined the expression of both protein and mRNA levels of 7 caspases in a panel of 18 breast cancer cell lines. We found that variation of caspase expression can occur at both protein and RNA levels. Down-regulation of these caspases, especially caspase-8 and -10, was frequently observed. Functional screening of these selected cell lines using TNF-alpha, doxorubicin and radiation induced cell injury showed that a lack of functional caspase-8 resulted in resistance to TNF-alpha-induced apoptosis. Array style examination of caspase expression profiles in breast cancer cell lines yields massive information that is valuable in establishing cell line models to study the role of caspase down-regulation/deficiency in breast cancer development and therapeutic resistance.