宫颈癌中SOCS-1表达的研究新进展

每年全球大约有38万宫颈癌新发病例,已成为现今世界女性最常见的妇科恶性肿瘤之一,高危型人类乳头瘤病毒(HPV-16、18等)是公认的宫颈癌的致病因素。研究证实HPV E7原癌基因的产物HPV E7原癌蛋白通过与抑癌蛋白p Rb结合,诱导p Rb的降解,导致宫颈上皮细胞永化生,致细胞生长增殖失控及细胞凋亡程序发生异常是HPV诱导宫颈癌发生的一个主要机制。细胞因子信号传导抑制蛋白(suppressor of cytokine signaling,SOCS)家族是由细胞产生的,可通过反馈调节来阻断细胞因子信号转导过程的一类负性调节因子,SOCS-1可抑制多种细胞因子的信号转导途径,调控体内多种免疫反应,现有研究表明SOCS-1可通过诱导E7蛋白降解来抑制HPV E7介导的异常转化。而且socs-1在癌细胞中表达明显降低,说明SOCS-1可能是抑癌基因,其失活机制主要是甲基化和杂合性缺失,所以说SOCS-1的甲基化和杂合性缺失对宫颈癌的发生、发展起着至关重要的作用,因此SOCS-1的去甲基化及打破基因沉默可能是一种潜在的治疗宫颈癌的新策略。     

Profiling of sugar transporter genes in grapevine coping with water deficit

The profiling of grapevine (Vitis vinifera L.) genes under water deficit was specifically targeted to sugar transporters. Leaf water status was characterized by physiological parameters and soluble sugars content. The expression analysis provided evidence that VvHT1 hexose transporter gene was strongly down-regulated by the increased sugar content under mild water-deficit. The genes of monosaccharide transporter VvHT5, sucrose carrier VvSUC11, vacuolar invertase VvGIN2 and grape ASR (ABA, stress, ripening) were up-regulated under severe water stress. Their regulation in a drought-ABA signalling network and possible roles in complex interdependence between sugar subcellular partitioning and cell influx/efflux under Grapevine acclimation to dehydration are discussed.     

Sine oculis homeobox homolog 1 promotes α5β1-mediated invasive migration and metastasis of cervical cancer cells

Sine oculis homeobox homolog 1 (SIX1) has been supposed to be correlated with the metastasis and poor prognosis of several malignancies. However, the effect of SIX1 on the metastatic phenotype of tumor cells and the underlying mechanisms were still unclear to date. Here we report that SIX1 can promote α5β1-mediated metastatic capability of cervical cancer cells. SIX1 promoted the expression of α5β1 integrin to enhance the adhesion capacity of tumor cells in vitro and tumor cell arrest in circulation in vivo. Moreover, higher expression of SIX1 in tumor cells resulted in the increased production of active MMP-2 and MMP-9, up-regulation of anti-apoptotic genes (BCL-XL and BCL2) and down-regulation of pro-apoptotic genes (BIM and BAX), thus promoting the invasive migration and anoikis-resistance of tumor cells. Importantly, blocking α5β1 abrogated the regulatory effect of SIX1 on the expression of these genes, and also abolished the promotional effect of SIX1 on invasive capability of tumor cells. Furthermore, knock-down of α5 could abolish the promoting effect of SIX1 on the development of metastatic lesions in both experimental and spontaneous metastasis model. Therefore, by up-regulating α5β1 expression, SIX1 not only promoted the adhesion capacity, but also augmented ECM-α5β1-mediated regulation of gene expression to enhance the metastatic potential of cervical cancer cells. These results suggest that SIX1/α5β1 might be considered as valuable marker for metastatic potential of cervical cancer cells, or a therapeutic target in cervical cancer treatment.     

Nitric oxide in fruit ripening: Trends and opportunities

Monitoring ethylene is crucial in regulating post-harvest life of fruits. The concept of nitric oxide (NO) involvement in antagonizing ethylene is new. NO mediated physiologies casted through regulation of plant hormones are widely reported during developmental and stress chemistry having no direct link with ripening. Research in NO biology and understanding its interplay with other signal molecules in ripening fruits suggest ways of achieving greater synergies with NO applications. Experiments focused at convincingly demonstrating the involvement of NO in altering ripening-related ethylene profile of fruits, would help develop new processes for shelf life extension. This issue being the central theme of this review, the putative mechanisms of NO intricacies with other primary and secondary signals are hypothesized. The advantage of eliciting NO endogenously may open up various biotechnological opportunities for its precise delivery into the target tissues.     

人乳头瘤病毒分型检测在宫颈病变中的研究进展

宫颈癌是感染性疾病,HPV感染是宫颈癌发生的主要因素。宫颈上皮内留样病变(CIN)是宫颈浸润癌演变发展过程中的癌前病变阶段,研究发现大多数CIN伴有人乳头瘤病毒(HPV)感染,不同HPV亚型的致病力不同,因此不同亚型的HPV感染可以导致不同的宫颈病变。对CIN早诊、早治是降低宫颈癌发生率和死亡率的关键,临床上应用HPV亚型检测对宫颈病变的初筛及治疗追踪具有重要意义。     

人乳头瘤病毒与宫颈癌关系研究进展

宫颈癌是一种严重危害女性健康的恶性肿瘤,其发病率较高,位居女性恶性肿瘤的第二位,仅次于乳腺癌。自从1977年德国学者ZurHausen等从宫颈癌标本中发现了人乳头瘤病毒(Human papillomavirus HPV)DNA,并推测HPV感染与宫颈癌发生有关后,许多学者对HPV与宫颈癌的相关性进行了大量的研究,并证实HPV感染是宫颈癌发病的必需因素。目前,对于宫颈HPV感染检测有多种手段,其中聚合酶链反应(PCR)和捕获杂交技术在实验室中应用较广泛。在宫颈癌筛查中联合应用HPV检测和细胞学,不仅可以提高敏感性,而且还可以减少随诊频率,从而大大降低了宫颈癌的发生。     

人乳头瘤病毒感染与宫颈癌的研究进展

人乳头瘤病毒(Human Papillomavirus HPV)感染是导致性传播疾病的常见原因,上世纪八十年代初,首次报道生殖器HPV感染与宫颈癌之间的联系,认为HPV感染是95%以上宫颈癌变的高危因素。随着分子生物学技术的发展,对HPV致癌机制的研究不断深入,取得大量有价值的成果,现就HPV的致癌途径与协同因素探讨宫颈癌的发病机制以及对HPV检测方法等方面的研究进行综述。     

携带HSV-1TK基因的逆转录病毒载体构建及在HeLa细胞中的表达

目的:构建携带单纯疱疹病毒脱氧胸腺嘧啶激酶基因(herpes simplex virus thymidine kinase,HSV-TK)的逆转录病毒,用于宫颈癌的治疗研究。方法:用限制性内切酶从质粒pcDNA3.1/HA-myc-His(-)Z-TK切下HSV-1TK cDNA序列,亚克隆入逆转录病毒载体pLXSN得到重组质粒pLXSN-TK,鉴定正确的阳性重组质粒经PA317细胞包装,G418筛选,在NIH3T3细胞进行病毒滴度测定。然后用病毒感染人宫颈癌细胞HeLa。PCR、RT-PCR和Western blotting方法检测HSV-1TK基因在HeLa中的整合和表达情况。结果:重组质粒pLXSN-TK经PA317细胞包装后收获病毒上清,感染HeLa细胞,检测发现HSV-1TK基因整合到细胞基因组DNA中,并且能有效的转录和翻译。结论:成功构建了逆转录病毒pLXSN-TK,该病毒能有效感染HeLa细胞,并使携带的治疗基因HSV-1TK在细胞中表达,为今后HSV-1TK基因治疗宫颈癌的研究奠定基础。     

香蕉一个Ⅲ类酸性几丁质酶基因与果实成熟关系的研究

为了解Ⅲ类酸性几丁质酶基因(MaCHⅢ)与香蕉果实采后成熟过程的相互关系,对经乙烯和1-甲基环丙烯(1-MCP)处理的巴西香蕉果实采后乙烯释放量、Ⅲ类酸性几丁质酶基因(MaCHⅢ)表达以及几丁质酶活性进行了测定.结果显示:(1)乙烯催熟处理的香蕉果实,乙烯释放量比对照处理的果实提前15 d达到高峰;1-MCP处理的香蕉果实,乙烯生物合成和果实成熟明显受到了抑制.(2)外源乙烯加速了MaCHⅢ基因的下调表达和Ⅲ类酸性几丁质酶活性的下降,MaCHⅢ表达量和Ⅲ类酸性几丁质酶活性分别在采后第3天和第4天下降到最小值.(3)1-MCP处理使MaCHⅢ基因呈现上调表达,Ⅲ类酸性几丁质酶活性上升,MaCHⅢ基因表达量和Ⅲ类酸性几丁质酶活性分别在采后18 d和25 d达到高峰.研究表明,MaCHⅢ基因可能与香蕉果实采后成熟呈负相关.