[Mutational analysis of hOGG1 gene promoter in patients with non-small cell lung cancer]

背景与目的

8-羟基鸟嘌呤DNA糖苷酶（8-hydroxygumine DNA glycosylase 1, OGG1）是一种DNA修复酶，可以从DNA切除修复8-羟基鸟嘌呤（8-dihydro-8-oxoguanine, 8-OH-G）。人类OGG1基因（hOGG1）的多态性可能会改变酶的活性而影响个体修复损伤DNA的能力，促进癌变。然而，hOGG1基因启动子区域的突变与非小细胞肺癌（non-small cell lung cancer, NSCLC）的关系尚不明晰。我们拟探讨hOGG1基因启动子区域的突变与NSCLC发生发展的潜在关系。

方法

选取苏州大学附属第一医院2003年1月-2005年12月新鲜手术切除的40例NSCLC组织标本，采用PCR-SSCP和直接测序的方法检测NSCLC及其对应的癌旁组织中hOGG1基因启动子区域的突变。

结果

在40例NSCLC患者中未发现hOGG1基因启动子区域的异常突变，但发现单核苷酸多态位点rs159153与TNM分期明显相关（P=0.008）；同时发现吸烟者中淋巴结转移率明显较低（P=0.034）。

结论

单核苷酸多态位点rs159153和吸烟史可能对NSCLC的侵袭和转移潜在性提供预测。

[Enrichment and function research of large cell lung cancer stem cell-like cells]

背景与目的

目前国内外还没有确切的、得到公认的肺癌干细胞的筛选标记分子、指标和方法，常用方法为通过流式细胞技术，借鉴其他肿瘤干细胞分选标记来分选肺癌干细胞，但其筛选特异性低、工作量巨大。本研究采用无血清悬浮培养法富集肺癌干细胞，对肺癌干细胞的筛选方法进行探索。

方法

采用添加生长因子的无血清培养基对人大细胞肺癌细胞株L9981进行悬浮培养，获得肺癌细胞球体。对含血清培养贴壁L9981细胞和无血清培养成球后的L9981细胞，通过显微镜下观察比较二者的生物学形态，应用Vi-cell细胞活力分析仪计数细胞并绘制生长曲线比较二者的增殖能力，通过Transwell实验研究它们的侵袭能力差异，并通过接种裸鼠观察二者在体内的成瘤性来研究肺癌细胞球体的生物学功能。

结果

与血清贴壁培养L9981细胞相比，无血清培养L9981细胞成球形生长，贴壁L9981和L9981球体细胞的倍增时间分别为（56.05±1.95）h和（33.00±1.44）h，球体细胞的侵袭和成瘤能力分别为贴壁L9981细胞的5倍和20倍。

结论

通过无血清悬浮培养的L9981细胞可以形成肺癌球体细胞群，L9981球体细胞的侵袭和成瘤能力均明显高于贴壁L9981细胞，显示L9981球体细胞中富集了肺癌干细胞样的细胞。无血清悬浮培养肺癌球体细胞可作为富集肺癌干细胞样细胞的一种候选方法。

67 PIG OOCYTES WITH A LARGE PERIVITELLINE SPACE MATURED IN VITRO HAVE GREATER DEVELOPMENTAL COMPETENCE AFTER PARTHENOGENESIS AND SOMATIC CELL NUCLEAR TRANSFER

The size of perivitelline space (PVS) is closely related with the frequency of polyspermic fertilization in pig oocytes. It has been reported that enlargement of PVS is attributed to accumulation of glycoproteins synthesised and secreted from cumulus cells and that culture of immature oocytes in low-salt medium enlarges PVS in pigs. This study examined the developmental competence of pig oocytes after parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT) in relation to the size of the PVS of oocytes matured in vitro (IVM). Cumulus–oocyte complexes were matured in medium 199 (Experiment 1) or porcine zygote medium (PZM)-3 (Experiment 2) supplemented with pig follicular fluid, cysteine, pyruvate, EGF, insulin, and hormones for the first 22 h and then cultured in hormone-free medium for an additional 22 h. IVM oocytes were activated electrically for PA or used as recipient cytoplasts for SCNT. PA and SCNT embryos were cultured for 7 days in PZM-3 medium supplemented with bovine serum albumin. The intracellular glutathione (GSH) level in IVM oocytes was determined by analysing the fluorescence intensity of oocytes after staining with CellTracker Blue CMF2HC. The expression of CDK1, PCNA, and ERK2 mRNA in IVM oocytes was analysed by RT-PCR. Data were analysed using a general linear model procedure followed by the least significant difference mean separation procedure when the treatments differed at P < 0.05. In Experiment 1, oocytes with a larger PVS had higher (P < 0.05) levels of intracellular GSH (1.0 pixels/oocyte v. 0.6 pixels/oocyte) and blastocyst formation (54% v. 37%) after PA than oocytes with smaller PVS. In Experiment 2, maturation culture of oocytes in PZM-3 with reduced (61.6 mM) NaCl concentration significantly increased (P < 0.05) the size of the PVS (5.2 μM v. 3.3 μM) compared with control oocytes that were matured in PZM-3 containing 108 mM NaCl, although the treatment did not alter the nuclear maturation. Moreover, oocytes with increased PVS expressed more CDK1, PCNA, and ERK2 mRNA and had higher (P < 0.05) intracellular GSH levels (1.6 pixels/oocyte v. 1.2 pixels/oocyte) and increased blastocyst formation after PA (52% v. 41%) and SCNT (32% v. 18%) compared with control oocytes. Our results demonstrate that pig oocytes with a large PVS have greater developmental competence after PA and SCNT, which is attributed to improved cytoplasmic maturation resulting from the enhanced GSH level and transcription factor expression and that enlargement of PVS by the culture in low-NaCl medium also improves developmental competence of pig oocytes. This work was supported by grants (#20070301034040 and #20080401034072) from the BioGreen 21 Program (Rural Development Administration, Republic of Korea).

Central venous pressure during the post-anhepatic phase is not associated with early postoperative outcomes following orthotopic liver transplantation

BACKGROUND

Fluid management during orthotopic liver transplantation poses unique challenges for the anesthesiologist. Maintenance of hypovolemia as indicated by low central venous pressure has been associated with reduced blood loss and improved outcomes in some studies, but with higher 30-day mortality and increased incidence of renal dysfunction in others. The primary aim was to evaluate the association of central venous pressure management after liver allograft reperfusion with immediate postoperative patient outcomes.

METHODS

This was a retrospective investigation evaluating the intraoperative and postoperative records of 144 consecutive patients who underwent orthotopic liver transplantation at a single institution.

RESULTS

We did not find any important association between central venous pressure management after graft reperfusion and postoperative patient outcomes. Specifically, these data do not support the hypothesis that maintenance of lower central venous pressure during the post-anhepatic phase of orthotopic liver transplantation is associated with improved immediate postoperative allograft function (except for a steeper decrease in post operative days 1-3 in 2 of the 3 liver function test: alanine aminotransferase and bilirubin) or overall patient survival, graft survival, composite graft/patient survival, intensive care length of stay, hospital length of stay or the occurrence of infections.

CONCLUSION

Maintaining a lower central venous pressure during the post-anhepatic phase during orthotopic liver transplantation is not associated with any benefit in terms of immediate postoperative allograft function, graft survival or patient survival.

[Defective expression of TGFBR3 gene and its molecular mechanisms in non-small cell lung cancer cell lines]

背景与目的

国外有研究表明，非小细胞肺癌（non-small cell lung cancer, NSCLC）中转化生长因子受体Ⅲ（TGFBR3）存在缺陷表达，但是分子机制尚未明确。本研究以正常支气管上皮细胞（human bronchial epithelial cell, HBEpiC）为对照，分析NSCLC细胞株中TGFBR3基因的表达情况，并探讨TGFBR3基因表达失活的分子机制。

方法

采用Western blot检测HBEpiC和NSCLC细胞株中TGFBR3的表达情况并做相对定量分析；采用DNA直接测序检测TGFBR3基因启动子基本转录元件区的突变情况；应用亚硫酸氢钠处理后测序法（bisulfite sequence-PCR, BSP）检测TGFBR3基因启动子区甲基化状态。

结果

NSCLC细胞株中TGFBR3表达水平明显低于HBEpiC；高转移细胞株95D明显低于非转移细胞株LTEP-α-2、A549、NCI-H460；HBEpiC与NSCLC细胞株中TGFBR3基因近端启动子区-165到-75区域无遗传突变，且未见甲基化，远端启动子区-314到-199区域均为高甲基化。

结论

TGFBR3基因在NSCLC细胞株中表达下调，在高转移细胞株95D中尤其明显，提示该基因的表达缺陷对NSCLC发生发展起重要作用，可能与NSCLC的侵袭和转移相关；然而，TGFBR3基因启动子区重要转录元件区域的甲基化状态并不是导致TGFBR3基因表达下调的主要原因。

A positive feedback between activated extracellularly regulated kinase and cyclooxygenase/lipoxygenase maintains proliferation and migration of breast cancer cells

Metastasis of breast cancer cells is the leading cause of death in breast cancer patients. Why do breast cancer cells with high metastatic potential always keep in high proliferation and migration? The endogenous signaling pathways associated with tumor metastasis remain unclear. In the present study, we address whether a link between ERK and the enzymes associated with arachidonic acid (AA) metabolism contributes to the proliferation and migration of breast cancer cells. To identify endogenous signaling pathways involved in sustaining proliferation and migration of breast cancer cells, we performed parallel studies of human breast cancer cell lines that differ in their metastatic potential. Our data showed that cell lines with high metastatic potential, including LM-MCF-7 and MDA-MB-231, exhibited significantly high, sustained levels of phosphorylated ERK (pERK) 1/2 relative to MCF-7 cells. Our findings showed that beta-catenin, cyclin D1, and survivin serve downstream effectors of pERK1/2, whereas Gi/o proteins, phospholipase C, and protein kinase C serve upstream activators of pERK1/2. In addition, AA metabolites were able to activate Gi/o proteins, phospholipase C, protein kinase C, and pERK1/2 cascades through cyclooxygenase and lipoxygenase. In contrast, activated ERK1/2 promoted AA metabolism through a positive feedback loop, which conduces to a high proliferative potential and the migration of the breast cancer cells. Together, our data provide new mechanistic insights into possible endogenous signaling metastatic signaling pathways involved in maintaining proliferation and migration of breast cancer cells.

Myosin light-chain kinase contributes to the proliferation and migration of breast cancer cells through cross-talk with activated ERK1/2

Myosin light-chain kinase (MLCK) plays a crucial role in the cell migration and tumor metastasis. Herein, we investigated the signaling pathways involved in MLCK using ML-7, a specific inhibitor of MLCK, in breast cancer cell proliferation and migration. Our data showed that reduction of MLCK in breast cancer cells mediated by 20 microM ML-7 was able to depress the cell proliferation and migration using two parallel cell lines (MCF-7 and LM-MCF/MDA-MB-231) with different metastatic abilities through reciprocal cross-talk with activated ERK1/2, in which both phosphorylated myosin light chain (p-MLC) and cascades of beta-catenin, cyclin D1, survivin, and c-Myc serve as essential downstream effectors.

Sendai virus-mediated CFTR gene transfer to the airway epithelium

The potential for gene therapy to be an effective treatment for cystic fibrosis has been hampered by the limited gene transfer efficiency of current vectors. We have shown that recombinant Sendai virus (SeV) is highly efficient in mediating gene transfer to differentiated airway epithelial cells, because of its capacity to overcome the intra- and extracellular barriers known to limit gene delivery. Here, we have identified a novel method to allow the cystic fibrosis transmembrane conductance regulator (CFTR) cDNA sequence to be inserted within SeV (SeV-CFTR). Following in vitro transduction with SeV-CFTR, a chloride-selective current was observed using whole-cell and single-channel patch-clamp techniques. SeV-CFTR administration to the nasal epithelium of cystic fibrosis (CF) mice (Cftr(G551D) and Cftr(tm1Unc)TgN(FABPCFTR)#Jaw mice) led to partial correction of the CF chloride transport defect. In addition, when compared to a SeV control vector, a higher degree of inflammation and epithelial damage was found in the nasal epithelium of mice treated with SeV-CFTR. Second-generation transmission-incompetent F-deleted SeV-CFTR led to similar correction of the CF chloride transport defect in vivo as first-generation transmission-competent vectors. Further modifications to the vector or the host may make it easier to translate these studies into clinical trials of cystic fibrosis.

Human amniotic fluid-derived stem cells have characteristics of multipotent stem cells

OBJECTIVES

To characterize mesenchymal stem cell-like cells isolated from human amniotic fluid for a new source of therapeutic cells.

MATERIALS

Fibroblastoid-type cells obtained from amniotic fluid at the time of birth.

METHODS

The ability of ex vivo expansion was investigated until senescence, and stem cell-like characteristics were analyzed by examining differentiation potential, messenger RNA expression and immunophenotypes.

RESULTS AND CONCLUSIONS

A morphologically homogenous population of fibroblastoid-type (HAFFTs) cells, similar to mesenchymal stem cells from bone marrow (BM-MSCs), was obtained at the third passage. The cells became senescent after 27 passages over a period of 8 months while undergoing 66 population doublings. Under appropriate culture conditions, by the 8th passage they differentiated into adipocytes, osteocytes, chondrocytes and neuronal cells, as revealed by oil red O, von Kossa, Alcian blue and anti-NeuN antibody staining, respectively. Immunophenotype analyses at the 17th passage demonstrated the presence of TRA-1-60; SSEA-3 and-4; collagen types I, II, III, IV and XII; fibronectin; alpha-SMA; vimentin; desmin; CK18; CD44; CD54; CD106; FSP; vWF; CD31; and HLA ABC. Reverse transcriptase-polymerase chain reaction analysis of the HAFFTs from passages 6-20 showed consistent expression of Rex-1, SCF, GATA-4, vimentin, CK18, FGF-5 and HLA ABC genes. Oct-4 gene expression was observed up to the 19th passage but not at the 20th passage. HAFFTs showed telomerase activity at the 5th passage with a decreased level by the 21st passage. Interestingly, BMP-4, AFP, nestin and HNF-4alpha genes showed differential gene expression during ex vivo expansion. Taken together, these observations suggest that HAFFTs are pluripotent stem cells that are less differentiated than BM-MSCs, and that their gene expression profiles vary with passage number during ex vivo expansion.

Aquatic toxicity due to residential use of pyrethroid insecticides

Pyrethroids are the active ingredients in most insecticides available to consumers for residential use in the United States. Yet despite their dominance in the marketplace, there has been no attempt to analyze for most of these compounds in watercourses draining residential areas. Roseville, California was selected as a typical suburban development, and several creeks that drain subdivisions of single-family homes were examined. Nearly all creek sediments collected caused toxicity in laboratory exposures to an aquatic species, the amphipod Hyalella azteca, and about half the samples caused nearly complete mortality. This same species was also found as a resident in the system, but its presence was limited to areas where residential influence was least. The pyrethroid bifenthrin is implicated as the primary cause of the toxicity, with additional contributions to toxicity from the pyrethroids cyfluthrin and cypermethrin. The dominant sources of these pyrethroids are structural pest control by professional applicators and/ or homeowner use of insecticides, particularly lawn care products. The suburbs of Roseville are unlikely to be unique, and similar sediment quality degradation is likely in other suburban areas, particularly in dry regions where landscape irrigation can dominate seasonal flow in some water bodies.

Hepatitis B virus X protein upregulates survivin expression in hepatoma tissues

The hepatitis B virus X protein (HBx) plays an important role in the development of hepatocellular carcinoma (HCC). The relationship was examined between HBV antigens and IAP (inhibitor of apoptosis) family in development of HCC. The expression levels of HBV antigens (HBsAg, HBcAg, and HBxAg) and members of the IAP family (survivin, XIAP, cIAP-1, and cIAP-2) were detected immunohistochemically in tissues from 34 cases of HCC and 30 cases of liver cirrhosis. The positive rate of survivin was higher than these three molecules in all three tissue types (P < 0.05). The positive rates of HBxAg and survivin were high in HCC (76.5% and 88.2%), paratumor (85.3% and 91.2%), and liver cirrhosis (100% and 93.3%) tissues, with no significant differences between the survivin- and HBxAg-positive rates (each P > 0.05). To examine the effect of HBx on survivin expression, plasmid pCMV-X (encoding the HBx gene) was transfected transiently with or without plasmid pcDNA3-sur (encoding the survivin gene) into H7402 hepatoma cells and L-O2 human normal liver cells. Cells over-expressing HBx alone showed increased apoptosis along with a dose-dependent increase in survivin levels. However, co-expression of survivin inhibited the HBx-induced apoptosis. To examine the effect of HBx on survivin in hepatoma cells without apoptosis, plasmid pCMV-X was transfected stably into human hepatoma H7402 cells and L-O2 cells. These H7402-X and L-O2-X cells showed high-level expression of both HBx and survivin, but did not show apoptosis. The addition of pSilencer 3.0-X, an RNAi vector targeting the HBx gene, reduced the expression levels of survivin protein in H7402-X cells. Collectively, these data demonstrate that HBx upregulates survivin expression in hepatoma tissues, suggesting that HBx and survivin may both be involved in carcinogenesis of HCC.

An FDK-like cone-beam SPECT reconstruction algorithm for non-uniform attenuated projections acquired using a circular trajectory

In this paper, Novikov's inversion formula of the attenuated two-dimensional (2D) Radon transform is applied to the reconstruction of attenuated fan-beam projections acquired with equal detector spacing and of attenuated cone-beam projections acquired with a flat planar detector and circular trajectory. The derivation of the fan-beam algorithm is obtained by transformation from parallel-beam coordinates to fan-beam coordinates. The cone-beam reconstruction algorithm is an extension of the fan-beam reconstruction algorithm using Feldkamp-Davis-Kress's (FDK) method. Computer simulations indicate that the algorithm is efficient and is accurate in reconstructing slices close to the central slice of the cone-beam orbit plane. When the attenuation map is set to zero the implementation is equivalent to the FDK method. Reconstructed images are also shown for noise corrupted projections.