Survivin和BDKRB1与宫颈鳞癌的发生与发展

目的探讨Survivin、缓激肽受体B1（bradykinin receptor B1,BDKRB1）在宫颈鳞癌（cervical squamous celi carcinomas,CSCC）发生、发展中的作用。方法采用半定量RT—PCR方法检测8例宫颈炎组织、13例宫颈上皮内瘤变（Cervical intraepithelial neopiasia,CIN）Ⅰ级、17例CINⅡ-Ⅲ级,31例CSCC组织中survivin和BDKRBImRNA表达,并将二者表达情况进行统计分析。结果sBrvivin及BDKRB1的表达量随宫颈病变由宫颈炎到CIN再到CSCC的进展逐渐升高;二者在CSCC组织中的表达随CSCC临床分期的升高逐渐升高,并与年龄、临床分期、浸润深度、脉管浸润、淋巴结转移、病理分级等临床病理参数相关;Spearman等级相关分析结果显示BDKRB1表达与survivin表达呈高度正相关（r=0．722,P〈0．005）;COX多元回归分析结果显示年龄、淋巴结转移伴脉管浸润、survivin和BDKRB1的表达为影响SCC患者预后的独立因素,随宫颈癌病理分级和临床分期的升高,CSCC病人的生存时间明显缩短。结论survivin和BDKRB1在CSCC的发生、发展、浸润和转移过程中起着重要作用并与CSCC病人的不良预后相关,检测survivin和BDKRBI1在宫颈病变组织中的表达有望用于CSCC的早期诊断和预后判断,靶向survivin的基因治疗与特异性BDKRB1拮抗剂联合应用有望改善CSCC患者的预后。     

Centrosomes,genomic instability,and cervical carcinogenesis

High-risk human papillomavirus (HPV)-associated carcinogenesis of the uterine cervix is a particularly useful model to study basic mechanisms of genomic instability in cancer. Cervical carcinogenesis is associated with the expression of two high-risk HPV-encoded oncoproteins, E6 and E7. Aneuploidy, the most frequent form of genomic instability in human carcinomas, develops as early as in nonmalignant cervical precursor lesions. In addition, cervical neoplasia is frequently associated with abnormal multipolar mitotic figures, suggesting disturbances of the cell-division process as a mechanism for chromosome segregation defects. Spindle poles are formed by centrosomes, and the high-risk HPV E6 and E7 oncoproteins can each induce abnormal centrosome numbers. These two HPV oncoproteins, however, induce centrosome abnormalities through fundamentally different mechanisms and, presumably, with different functional consequences. High-risk HPV E7, which targets the pRB tumor suppressor pathway, can provoke abnormal centrosome duplication in phenotypically normal cells. On the contrary, cells expressing the HPV E6 oncoprotein, which inactivates p53, accumulate abnormal numbers of centrosomes in parallel with multinucleation and nuclear atypia. These two pathways are not mutually exclusive, since co-expression of HPV E6 and E7 has synergistic effects on centrosome abnormalities and chromosomal instability. Taken together, these findings support the general model in which chromosomal instability arises as a direct consequence of oncogenic insults and can develop at early stages of tumor progression.     

Effect of the host cell on the maintenance and replication of Epstein-Barr virus.

We have studied the role the host cell plays in controlling the expression of the Epstein-Barr virus (EBV) by using Burkitt somatic cell hybrids of human and mouse cells. Mouse/Burkitt somatic-cell hybrids were shown to contain a repressed EBV genome that was inducible with iododeoxyuridine. Electron microscopic examination of human/Burkitt hybrid cells (D98/HR-1 and D98/Raji) and Burkitt lymphoblastoid cells in which EBV was replicating showed an enhancement of virus replication concomitant with an enhancement of EBV-specific cytopathologic effect in D98/HR-1 and D98/Raji cells when compared to Burkitt lymphoblastoid cells. When the stability of the EBV genome in human/Burkitt hybrid cells was studied, it was found that the EBV genome in hybrids of the nonproducer Burkitt cells (Raji) was less stable over time than hybrid cells of producer cells (HR-1). The data obtained in this study support the concept that the cell in which the EBV genome resides plays a major role in the maintenance, expression, and replication of EBV.     

Capture of cell culture-derived influenza virus by lectins: strain independent, but host cell dependent

Strategies to control influenza outbreaks are focused mainly on prophylactic vaccination. Human influenza vaccines are trivalent blends of different virus subtypes. Therefore and due to frequent antigenic drifts, strain independent manufacturing processes are required for vaccine production. This study verifies the strain independency of a capture method based on Euonymus europaeus lectin-affinity chromatography (EEL-AC) for downstream processing of influenza viruses under various culture conditions propagated in MDCK cells. A comprehensive lectin binding screening was conducted for two influenza virus types from the season 2007/2008 (A/Wisconsin/67/2005, B/Malaysia/2506/2004) including a comparison of virus-lectin interaction by surface plasmon resonance technology. EEL-AC resulted in a reproducible high product recovery rate and a high degree of contaminant removal in the case of both MDCK cell-derived influenza virus types demonstrating clearly the general applicability of EEL-AC. In addition, host cell dependency of EEL-AC was studied with two industrial relevant cell lines: Vero and MDCK cells. However, the choice of the host cell lines is known to lead to different product glycosylation profiles. Hence, altered lectin specificities have been observed between the two cell lines, requiring process adaptations between different influenza vaccine production systems.     

The biology of Epstein-Barr virus: lessons learned from the virus and the host.

Recent studies indicate that a large proportion of cytotoxic T cells are directed towards the Epstein-Barr virus (EBV) during both acute infection and convalescence. The virus, in turn, has usurped cellular pathways to promote proliferation of infected cells and has pirated cellular genes into its genome to modulate the immune system to allow lifelong infection of humans. Analysis of the immune response to the virus is leading to novel therapies for EBV-associated malignancies, including the use of virus-specific cytotoxic T cell infusions.     

Characterization of the host cell entry of filamentous influenza virus

Summary. Most laboratory-adapted strains of influenza virus exist as spheres of approximately 100 nm in diameter, which are well established to enter cells by endocytosis in a pH-dependent manner. However, influenza virus isolated from the lungs of infected individuals is believed to exist as predominantly filamentous particles, up to several micrometers in length. Here, we have attempted an initial characterization of the entry of purified influenza virus filaments into host cells – in comparison to more commonly studied spherical forms of the virus. We demonstrate that the internalization of filamentous influenza virus particles is delayed, relative to spherical particles, and that this delay is a result of morphological rather than strain differences. The filamentous influenza particles appear to retain their dependence on low-pH for entry, as demonstrated by a vacuolar-ATPase inhibitor, and viral trafficking to late endosomes, as demonstrated by the requirement for protein kinase C function. However, our data suggest that the endocytic uptake of the filamentous virus particles may be dynamin-independent, unlike spherical virions. Overall, these data provide a view of the entry of influenza virus in its filamentous morphology, demonstrating potential differences between the endocytosis of spherical virions in vitro and filamentous virions in vivo.     

Influence of host cell type on the density of herpes simplex virus particles.

The densities of purified herpes simplex virus (HSV) particles prepared from infected rabbit lung (ZP) and baby hamster kidney (BHK-21) cells were investigated in potassium tartrate (PT) and potassium citrate (PC) density gradients. Virions obtained from ZP cells exhibited a higher density than those from BHK-21 cells. In PT and PC gradients, the former banded at densities of 1.226 and 1.267, while tha latter at 1.194 and 1.233, respectively. Deenveloped viral particles prepared by Nonidet P-40 treatment from purified virions of either origin were found in PT and PC gradients at the densities of 1.263 and 1.320, respectively. The possible causes of the density change of virions propagated in different hosts are discussed.     

Bacterial-modulated host immunity and stem cell activation for gut homeostasis

Although it is widely accepted that dynamic cross-talk between gut epithelia and microorganisms must occur to achieve gut homeostasis, the critical mechanisms by which gut–microbe interactions are regulated remain uncertain. In this issue of Genes & Development, Buchon and colleagues (pp. 2333–2344) revealed that the reaction of the gut to microorganisms is not restricted to activating immune systems, but extends to integrated responses essential for gut tissue homeostasis, including self-renewal and the differentiation of stem cells. Further investigation of the connection between immune response and stem cell regulation at the molecular level in the microbe-laden mucosal epithelia will accelerate our understanding of the regulatory mechanisms of gut homeostasis and of the pathogenesis of diseases such as chronic inflammatory diseases and colorectal cancers.     

Senescence and apoptosis in carcinogenesis of cervical squamous carcinoma.

Senescence and apoptosis are two key mechanisms that protect against cancer development. Many cell cycle regulators, such as p14(ARF), p15(INK4b) and p16(INK4a), are important in G1 cell cycle arrest and oncogene-induced senescence. The bcl-2 protein is one of the key components that control apoptosis, while the p53 protein plays key roles in both mechanisms. The genes of these key regulator proteins are often mutated or deleted in various malignancies. It is unknown how senescence and apoptosis are regulated in one of the most common tumors of the female genital tract, cervical squamous cell carcinoma (SCC). In this study the, expression of senescence, apoptosis and proliferation markers in normal cervical epithelium, cervical intraepithelial neoplasia (CIN) and SCC are characterized via immunohistochemical staining for p14(ARF), p15(INK4b), p16(INK4a), bcl-2, p53 and Ki-67 in tissue microarray blocks containing 20 samples each of normal cervix, moderate-to-severe cervical dysplasia (CIN II-III) and invasive SCC. Samples are derived from 60 total cases of cervical biopsies and cervical conizations. Results showed that the proliferation marker, Ki-67, is markedly increased, and the senescence markers, p15(INK4b), p16(INK4a) and p14(ARF) are overexpressed in both dysplasia and carcinoma. P53 immunostain is negative in all normal cervical tissue, and positive in dysplasia and carcinoma. Although the expression of bcl-2 is increased in dysplasia, this marker is negative in approximately half of SCC cases. These results suggest that some senescence pathways are activated and are still maintained in cervical dysplasia and carcinoma. However proliferation is increased and carcinogenesis is not thwarted, leading to eventual development of cervical cancer. Other mechanisms, such as those that account for the apparent overexpression of p53 and paradoxical loss of bcl-2 expression in some SCC cases, as well as additional senescence and apoptotic pathways, may play key roles carcinogenesis of cervical SCC.     

Influence of scaffold design on host immune and stem cell responses

The combined culture of isolated stem cells in tissue engineering scaffolds represents a popular strategy for the regeneration of specialized tissues. Despite of improved outcomes in some tissues, this stem cell-seeded tissue engineering strategy has not led to significant tissue regeneration as expected. The lower-than-expected outcome may be caused by overwhelming immune responses to scaffold materials and poor survival of seeded stem cells following implantation. This review is aimed at summarizing the success and failure of this strategy and also shedding some light on new directions to design scaffolds for promoting regenerative responses via autologous stem cells. The first half of this review summarizes the influence of scaffold physical and chemical properties on immune cell responses to scaffold implants. The second half focuses on the influence of scaffold design to alter immune and stem cell responses for achieving desirable tissue regeneration.     

Japanese encephalitis virus replication: Studies on host cell nuclear involvement

Replication, as measured by virus production, of both the flavivirus Japanese encephalitis virus (JEV) and the alphavirus Venezuelan encephalitis virus (VEV) was unaffected by short pulses of actinomycin D (act D) at early times postinfection (PI). Replication of JEV was found to be partially inhibited by continuous exposure to act D under conditions where VEV replication was equally sensitive to the drug. JEV replication proceeded normally in the presence of mitomycin C, a DNA synthesis inhibitor. Autoradiographic analysis revealed that virus-specific RNA was present only in the cytoplasm at both early and late times PI. When infected cell membranes were separated on a discontinuous sucrose gradient, most of the virus-specific RNA was associated with the endoplasmic reticulum fraction.     

Influence of the host cell on proteins synthesized by different strains of influenza virus.

The synthesis of influenza virus proteins has been studied quantitatively in nine different virus-cell systems, using three strains and three cell lines. The systems were remarkable for their variation. The only common properties to emerge were that NS₁ and NP were always synthesized earlier than M and HA₀ and secondly, with the exception of the P proteins, proteins were synthesized in amounts proportional to their time of appearance, i.e., the first protein to appear was present in the greatest amount. Otherwise variations were found in the order of appearance of newly synthesized proteins, in the relative amounts synthesized, and in the total synthesized. These variations were unrelated to virus strain or cell type, to the yield of infectious virus, or to its infectivity: HA ratio, and to the shut-off of host protein synthesis. We conclude that the pattern of protein synthesis in a particular virus-cell system is unique.     

Risk factors for cytomegalovirus DNAemia following haploidentical stem cell transplantation and its association with host hepatitis B virus serostatus

BackgroundThe risk factors associated with CMV DNAemia are not well known after haploidentical stem cell transplantation (SCT).ObjectivesThis study investigated the risk factors and prognosis for CMV DNAemia among CMV seromatched donors and recipients (D+/R+).Study designA retrospective study of patients undergoing haploidentical stem cell transplantation (SCT) between January 2010 and January 2012 was conducted. Cox regression analysis was performed to identify the risk factors for CMV DNAemia. These possible factors included recipient/donor age, recipient/donor gender, gender disparity, recipient HBsAg serostatus, diagnosis, risk stratification, anti-thymocyte globulin (ATG) dose (6 mg/kg,10 mg/kg), early neutrophil engraftment (≤12 days, >12 days), absolute lymphocyte count on day 30 (ALC30) and the occurrence of acute GVHD before CMV DNAemia.ResultsThe total number of patients was 248 with median age of 31 years (range, 14–56). The cumulative incidence of CMV DNAemia (146/248) was 59.5%. CMV DNAemia was first detected after a median of +35 days (range,12–82). Seventeen patients (17/146, 11.6%) developed CMV disease. Multivariate analysis identified HBsAg seropositivity (P = 0.002, hazard ratio (HR) = 1.833; 95%CI = 1.257–2.673) and the occurrence of acute GVHD before CMV DNAemia (P = 0.014; HR = 1.520; 95%CI = 1.088–2.124) as risk factors for CMV DNAemia. CMV DNAemia was associated with subsequent II-IV acute graft-versus-host disease (GVHD) (P = 0.014), III-IV aGVHD (P = 0.013) and chronic GVHD (P = 0.008). Totally, CMV DNAemia was found to be a poor prognostic factor in terms of non-relapse mortality (NRM) (P = 0.003, HR = 2.730; 95%CI = 1.406–5.197), and overall survival (OS) (P = 0.045, HR = 1.654; 95%CI = 1.012–2.701).ConclusionsOur data showed HBsAg seropositivity was associated with an increased risk of cytomegalovirus DNAemia. Detection of CMV DNAemia proved to be a poor prognostic factor for haploidentical patients.