Ki-67和Pten在子宫内膜癌中的表达及临床意义

目的：探讨子宫内膜癌组织中pten和Ki-67蛋白表达以及与子宫内膜癌发生、发展及预后的关系。方法：应用免疫组化SP法检测子宫内膜增生15例，子宫内膜不典型增生28例，子宫内膜癌62例中Ki-67和pten基因的表达，并分析其与子宫内膜癌发生，发展及预后的关系。结果：子宫内膜癌组中Ki-67蛋白阳性率明显高于增生期子宫内膜组及子宫内膜不典型增生组Ki-67蛋白阳性率（P〈0．05，P〈0．05），而子宫内膜癌组中pten蛋白阳性率明显低于子宫内膜不典型增生组及增生期子宫内膜组pten蛋白阳性率（P〈0．05，P〈0，05）；Ki-67在子宫内膜癌中的表达与组织分化、临床分期均显著相关（P〈0．01，P〈0．05），但其与肌层浸润、淋巴结转移无关（P〉0．05，P〉0．05），pten的表达与组织分化、肌层浸润深度、临床分期及淋巴结转移均显著相关（P〈0．5，P〈0．05，P〈0．01，P〈0．05）。结论：Ki-67和pten可能在子宫内膜癌的发生、发展及预后起着重要的作用，同时也是诊断子宫内膜癌及癌前病变的有价值的分子标记物。     

In vivo adenovirus-mediated gene transduction into mouse endometrial glands: a novel tool to model endometrial cancer in the mouse

Objective. The lack of an endometrial epithelium-specific promoter has slowed down the development of technically advanced mouse models of endometrial cancer. The aim of this study was to test whether direct in vivo adenoviral-mediated gene delivery can be used to circumvent this problem.Methods. Adenoviruses expressing the LacZ reporter gene or the Cre recombinase were injected into the left horn of the mouse uterus. Histochemistry and immunohistochemistry were used to detect expression of the reporter gene as well as targeted deletion of a floxed allele.Results. Our data demonstrate that in vivo direct injection of adenoviruses can efficiently target the endometrium in the mouse, specifically transducing genes to the glandular epithelial component.Conclusions. This approach will allow the generation of more refined and genetically defined mouse models of endometrial cancer. Endometrial gland-specific transient expression of recombinases, such as Cre, may thus be employed to delete engineered alleles of tumor suppressor genes and to activate the expression of latent oncogenes.     

Pten regulates neural crest proliferation and differentiation during mouse craniofacial development

Background: The phosphatase and tensin homolog deleted on chromosome TEN (Pten) is implicated in a broad range of developmental events and diseases. However, its role in neural crest and craniofacial development has not been well illustrated. Results: Using genetically engineered mouse models, we showed that inactivating Pten specifically in neural crest cells causes malformation of craniofacial structures. Pten conditional knockout mice exhibit perinatal lethality with overgrowth of craniofacial structures. At the cellular level, Pten deficiency increases cell proliferation rate and enhances osteoblast differentiation. Our data further revealed that inactivating Pten elevates PI3K/Akt signaling activity in neural crest derivatives, and confirmed that attenuation of PI3K/Akt activity led to decreased neural crest cell proliferation and differentiation both in vitro and in vivo. Conclusions: Our study revealed that Pten is essential for craniofacial morphogenesis in mice. Inactivating Pten in neural crest cells increases proliferation rate and promotes their differentiation toward osteoblasts. Our data further indicate that Pten acts via modulating PI3K/Akt activity during these processes. Developmental Dynamics 247:304–314, 2018. © 2017 Wiley Periodicals, Inc.     

Regeneration of Drosophila sensory neuron axons and dendrites is regulated by the Akt pathway involving Pten and microRNA bantam

Both cell-intrinsic and extrinsic pathways govern axon regeneration, but only a limited number of factors have been identified and it is not clear to what extent axon regeneration is evolutionarily conserved. Whether dendrites also regenerate is unknown. Here we report that, like the axons of mammalian sensory neurons, the axons of certain Drosophila dendritic arborization (da) neurons are capable of substantial regeneration in the periphery but not in the CNS, and activating the Akt pathway enhances axon regeneration in the CNS. Moreover, those da neurons capable of axon regeneration also display dendrite regeneration, which is cell type-specific, developmentally regulated, and associated with microtubule polarity reversal. Dendrite regeneration is restrained via inhibition of the Akt pathway in da neurons by the epithelial cell-derived microRNA bantam but is facilitated by cell-autonomous activation of the Akt pathway. Our study begins to reveal mechanisms for dendrite regeneration, which depends on both extrinsic and intrinsic factors, including the PTEN-Akt pathway that is also important for axon regeneration. We thus established an important new model system--the fly da neuron regeneration model that resembles the mammalian injury model--with which to study and gain novel insights into the regeneration machinery.     

Cancer genetics-guided discovery of serum biomarker signatures for diagnosis and prognosis of prostate cancer

A key barrier to the realization of personalized medicine for cancer is the identification of biomarkers. Here we describe a two-stage strategy for the discovery of serum biomarker signatures corresponding to specific cancer-causing mutations and its application to prostate cancer (PCa) in the context of the commonly occurring phosphatase and tensin homolog (PTEN) tumor-suppressor gene inactivation. In the first stage of our approach, we identified 775 N-linked glycoproteins from sera and prostate tissue of wild-type and Pten-null mice. Using label-free quantitative proteomics, we showed that Pten inactivation leads to measurable perturbations in the murine prostate and serum glycoproteome. Following bioinformatic prioritization, in a second stage we applied targeted proteomics to detect and quantify 39 human ortholog candidate biomarkers in the sera of PCa patients and control individuals. The resulting proteomic profiles were analyzed by machine learning to build predictive regression models for tissue PTEN status and diagnosis and grading of PCa. Our approach suggests a general path to rational cancer biomarker discovery and initial validation guided by cancer genetics and based on the integration of experimental mouse models, proteomics-based technologies, and computational modeling.     

PTEN/mTOR and axon regeneration

How axon regeneration is controlled in both PNS and CNS remains elusive. Mechanistic studies of axon growth during development and axon regeneration after injury reveal the PTEN dependent molecular mechanism as a commonality. This pathway could impact the processes occurring in the neuronal soma, such as mTOR-regulated protein translation, and in the axons, such as cytoskeleton assembly. In this review, we will discuss the current understanding of the involvement of these processes in the regulation of axon growth and the potential implication in promoting axon regeneration after injury.     

Role of Pten in leukemia stem cells

Chronic myeloid leukemia (CML) is initiated from the BCR-ABL-expressing leukemia stem cells (LSCs). These LSCs are highly resistant to BCR-ABL kinase inhibitors, imatinib, dasantinib and nilotinib, and methods for eradication of LSCs are still not available. It is critical to identify genes that play roles in survival and proliferation of LSCs. We recently discovered that the tumor suppressor gene Pten is downregulated in LSCs of CML mice. By genetic deletion or overexpression of Pten, we confirmed that Pten functions as a tumor suppressor in LSCs of CML, consistent with the role of Pten in LSCs of acute myeloid leukemia (AML) and progenitor cells of T-ALL progenitors. Functional enhancement of the Pten pathway provides a therapeutic strategy for targeting LSCs.     

Functional inactivation of Rb sensitizes cancer cells to TSC2 inactivation induced cell death

We showed previously that inactivation of TSC2 induces death in cancer cells lacking the Retinoblastoma (Rb) tumor suppressor under stress conditions, suggesting that inactivation of TSC2 can potentially be used as an approach to specifically kill cancers that have lost WT Rb. As Rb is often inactivated in cancers by overexpression of cyclin D1, loss of p16^ink4a cdk inhibitor, or expression of viral oncoproteins, it will be interesting to determine if such functional inactivation of Rb would similarly sensitize cancer cells to TSC2 inactivation induced cell death. In addition, many cancers lack functional Pten, resulting in increased PI3K/Akt signaling that has been shown to modulate E2F-induced cell death. Therefore it will be interesting to test whether loss of Pten will affect TSC2 inactivation induced killing of Rb mutant cancer cells. Here, we show that overexpression of Cyclin D1 or the viral oncogene E1a sensitizes cancer cells to TSC2 knockdown induced cell death and growth inhibition. On the other hand, knockdown of p16^ink4a sensitizes cancer cells to TSC2 knockdown induced cell death in a manner that is likely dependant on serum induction of Cyclin D1 to inactivate the Rb function. Additionally, we demonstrate that loss of Pten does not interfere with TSC2 knockdown induced cell death in Rb mutant cancer cells. Together, these results suggest that TSC2 is potentially a useful target for a large spectrum of cancer types with an inactivated Rb pathway.     

成骨细胞特异性Pten基因敲除小鼠发生骨质硬化症

目的:研究Pten基因及其介导的PI3K/AKT信号通路在骨代谢平衡过程中的作用并建立相应的骨代谢疾病小鼠动物模型.方法:在利用Cre-LoxP系统获得成骨细胞特异性Pten基因敲除小鼠的基础上,利用X线摄影术、骨密度分析及组织学染色方法分析Pten基因敲除小鼠较野生型小鼠的骨量变化情况,进一步提取2种基因型小鼠骨组织RNA,通过实时定量PCR分析成骨细胞的标志基因如胶原Ⅰ、碱性磷酸酶、骨钙素等标志分子的表达情况.结果:获得了成骨细胞特异性Pten基因敲除小鼠,Pten基因敲除后小鼠的体型较野生型小鼠没有明显改变,但X线片、骨密度及组织学分析均表明Pten敲除小鼠骨量明显增加,发生了与人类骨质硬化症相类似的表型:此外,实时定量PCR的分析结果显示,成骨细胞的标志基因如胶原Ⅰ、碱性磷酸酶、骨钙素等标志分子的表达都有明显的升高.结论:成功地建立了Pten基因敲除骨质硬化症小鼠动物模型.