[Advances of hypoxia and lung cancer]

肺癌是我国发病率和死亡率增长最快, 对人群健康和生命威胁最大的恶性肿瘤, 其发生发展机制尚未完全清楚。肿瘤的低氧微环境发现于1955年, 而肺癌组织低氧直至2006年才被成功检测到。随着研究的深入, 低氧对肺癌的影响不仅限于对放疗的抵抗作用, 而且还会通过一个重要的促癌分子低氧诱导因子(hypoxia inducible factor, HIF)以及其调节蛋白脯氨酸羟化酶(prolyl hydroxylase domain, PHD)和希佩尔•林道病基因产物(product of von Hippel-Lindau gene, pVHL)对肺癌的发生发展、侵袭转移、化疗耐药以及预后等产生重要的调节作用。因此, 低氧、HIF、PHD和pVHL必将成为十分有潜力的肺癌治疗靶点。

[Research advance on mechanism and application of HATs and HDACs in epithelial-mesenchymal transition of lung cancer]

肺癌是危害我国人民健康与生命的重大疾病之一, 肺癌的复发和死亡多源于肿瘤转移。上皮细胞的间质化过程(epithelial-mesenchymal transition, EMT)是肺癌转移中的一个关键步骤, 此过程涉及E-cadherin表达下调, 并受到EMT转录因子调控。组蛋白乙酰转移酶(histone acetyltransferases, HATs)和组蛋白去乙酰化酶(histone deacetyltransferases, HDACs)是催化组蛋白乙酰化和去乙酰化的蛋白家族, 不仅在肿瘤进程中发挥重要功能, 近年来发现它们同样参与肺癌EMT过程。HATs与HDACs和某些EMT转录因子有相互作用。而且, 这些EMT转录因子的功能受乙酰化调控, 并影响肺癌EMT进程。本文将分别介绍HATs和HDACs参与肺癌EMT的作用机理, 从分子机制方面对它们之间的相互作用进行探讨, 并讨论HDAC抑制剂在抑制EMT和肺癌治疗方面的潜在应用价值, 以期为相关基础研究和临床实践提供借鉴。

Differential processing of neuropeptide proprotein in human breast adenocarcinoma

BACKGROUND

The processing of proprotein convertase (PC)-mediated neuropeptide plays a very important role in carcinogenesis and tumor proliferation.

AIM

To investigate proneuropeptide processing mechanism in tumorigenesis and tumor proliferation.

MATERIALS AND METHODS

The expression and processing profiles of PC1, carboxypeptidase E (CPE), PC2, GHRH, or neuropeptide Y (NPY) gene and protein level were investigated between 42 human breast tumor tissues and 21 tumor-adjacent normal tissues.

RESULTS

Gene analyses indicated that the proPC1, CPE, or preproNPY gene had higher expression in the breast tumor tissues, whereas the proPC2 or preproGHRH gene showed lower expression in the tissues. Protein analyses showed that the proPC1, PC1, CPE, GHRH, and preproNPY proteins were upregulated in the tumor tissues, whereas the proPC2, PC2, preproGHRH, and NPY proteins were down-regulated in them. The tissue results were highly corroborated with the serum data from the tumor patients and healthy women.

CONCLUSIONS

The higher PC1 and CPE expressions as well as the transformation of more proGHRH into active GHRH peptide suggest stronger PC1/CPE-mediated neuropeptide processing in the tumor, whereas the lower PC2 expression as well as the transformation of less proNPY into active NPY peptide suggests a weak PC2-mediated processing in it. The alterations of the convertase expressions and processing show that there is a differential proprotein processing system in the tumor, which leads to the abnormal distributions of species, ratio, and concentration of (pro)peptide(s) in the microenvironment of cells. The latter may contribute to cancer progression.

Performance of comorbidity indices in measuring outcomes after acute myocardial infarction in Australian indigenous and non-indigenous patients

BACKGROUND

Indigenous Australians have higher prevalence of chronic diseases and worse acute care outcomes than other Australians. The extent to which higher chronic disease comorbidity levels are responsible for their worse outcomes is not clear, and the performance of comorbidity indices has not been assessed for this population with very high comorbidity levels.

METHODS

Using hospital separations data, the Charlson and Elixhauser comorbidity indices were used to measure chronic disease prevalence in 2035 indigenous and non-indigenous patients hospitalised after their first acute myocardial infarction (AMI) in the Northern Territory of Australia between 1992 and 2004, and to adjust for comorbidity in multivariate analysis of mortality outcomes (in-hospital and long-term deaths from coronary heart disease and all causes). Index performance was assessed by the difference between C statistic, Akaike information criterion statistic and estimate of excess indigenous mortality in models with and without comorbidity adjustment.

RESULTS

Comorbidity index scores were higher for indigenous than non-indigenous patients and increased considerably over time, at least partly because of information bias. Indigenous patients' higher risk of in-hospital all-cause death was almost fully explained by their higher comorbidity levels. Their higher risk of long-term coronary heart disease and all-cause death was partially explained by higher comorbidity levels. Charlson and Elixhauser indices performed satisfactorily and similarly in this population.

CONCLUSION

Comorbidity indices performed well in a population with very high chronic disease prevalence. After adjusting for comorbidity, short-term outcomes were similar for indigenous and non-indigenous AMI patients, but comorbidity at the time of the acute episode only partly explained the worse long-term outcomes for indigenous patients.

Neural transdifferentiation of human bone marrow mesenchymal stem cells on hydrophobic polymer-modified surface and therapeutic effects in an animal model of ischemic stroke

Human bone marrow-derived mesenchymal stem cells (MSCs) have multi-lineage differentiation potential and can become cells of mesodermal and neural lineages. These stem cells thus hold considerable clinical promise for the treatment of neurodegenerative diseases. For successful regeneration of damaged neural tissues, directed differentiation of neural or neuronal precursor cells from MSCs and integration of transplanted cells are pivotal factors. We induced MSCs into neurogenesis using a modified protocol. The therapeutic potency of the resulting neural progenitor cells in a rat model of ischemic stroke was analyzed. Using a highly hydrophobic diphenylamino-s-triazine-bridged p-phenylene (DTOPV)-coated surface and adopting a procedure for propagation of neural stem cells, we efficiently converted MSCs into neurosphere-like cellular aggregates (NS-MSCs). The spherical cells were subsequently induced to differentiate into neural cells expressing neuroectodermal markers. To determine whether these cells had neuronal fates and induced neuro-protective effects in vivo, NS-MSCs were intra-cerebrally administered to rats 48h after permanent middle cerebral artery occlusion (pMCAo). The results showed a remarkable attenuation of ischemic damage with significant functional recovery, although the cells were not fully incorporated into the damaged tissues on post-operative day 26. Improvement in the NS-MSC-transplanted rats was faster than in the MSC group and suppression of inflammation was likely the key factor. Thus, our culture system using the hydrophobic surface of a biocompatible DTOPV coating efficiently supported neural cell differentiation from MSCs. Neural-primed MSCs exhibited stronger therapeutic effects than MSCs in rat brains with pMCAo.

Surfactant-mediated gene transfer for animal cells

A commercially available cationic surfactant, dimethyl-dioctadecyl ammonium bromide (DDAB), was used for making lipid vesicles. DDAB easily dissolved in water at 60 °C and formed lipid vesicles at room temperature. The lipid vesicles showed very low cytotoxicity compared with other cationic surfactants. After the lipid vesicles were mixed with plasmid DNA solution, the solution was added to mammalian cells. The addition of a nonionic surfactant (Tween 80) to the cationic lipid vesicles at the weight ratio of 1:1 enhanced transfection efficiency. Adding more or less than the optimal amounts of DNA and lipid vesicles resulted in decreased transfection efficiency. With the optimal amounts of DNA (pCMVβ) and lipid vesicles, about 90-95% of CHO-K1 and BHK-21C13 cells transiently expressed β-galactosidase activity 24 h after transfection. By this procedure, stable transformants around 10(5) cells corresponding to 10% efficiency could be obtained by one batch transfection.

The mean intensity ofo activation than the number of activated voxels is a better index to reflect the levels of visuospatial performance

This study is to identify the more sensitive method to measure the brain activation by the visuospatial performance level by comparing two different methods of measuremtnt (i.e., a method calculating the number of activated voxels and the other, the mean intensity of activated voxels). Sixteen right-handed male college students (mean age 23.2 years) participated in this study and function brain images were scanned with a 3T MRI using the single-shot EPI method during visuospatial performance. There found no brain areas with correlation between the visuospatial performance level and number of activated voxels. However, there found a sifgnificant correlatgion between the visuospatial performance level and the mean intensity of selected activated voxels in the parietal, frontal, and other areas.f In conclusion, the method of meanintensity rather than the one of the number is considered as a better index.

[Advances of DNA methylation in early diagnosis of lung cancer]

Lung cancer is the leading cause of cancer-related death and thus a major health problem nowadays. No early diagnostic method is ideal up to now. Changes in DNA methylation occur on early stage of lung cancer. Detection of DNA methylation is expected to be an important method in early diagosis of lung cancer.

[Screening of metastasis-related microRNAs in the large-cell lung cancer cell lines with different metastastic potentials]

背景与目的

微小RNA（microRNAs, miRNAs）参与调节肿瘤发生发展的多个过程，包括细胞的分裂增殖、细胞周期、凋亡、血管形成、侵袭和转移等。本研究应用miRNA芯片检测具有高低不同转移潜能人大细胞肺癌细胞株L9981和NL9980的miRNA表达谱，从中筛选出与大细胞肺癌转移相关的miRNAs。

方法

收集L9981和NL9980细胞，抽提总RNA进行CY3标记，将标记RNA在miRNA芯片上进行杂交反应。通过数据统计分析，筛选出表达明显差异的miRNAs。应用Real-time PCR验证芯片结果，并应用生物信息学方法预测靶基因。

结果

在不同转移潜能人大细胞肺癌L9981和NL9980细胞株中共筛选到22个表达明显差异的miRNAs。与NL9980相比，在L9981中有13个miRNAs表达上调，9个表达下调。Real-time PCR验证miR-125a-3p在细胞中的表达水平与芯片结果趋势一致，预测其靶基因可能为胰岛素样生长因子2。

结论

筛选得到与大细胞肺癌转移相关的miRNA表达谱。

P2-08-12: Additional Lesion Found in Preoperative Breast MRI; Is Routine Use Justified?

Preoperative breast MRI has been increasingly performed in patients with newly diagnosed breast cancer due to its high sensitivity in assessing the extent and additional malignant foci. But due to it's low specificity, role of routine preoperative breast MRI has become an issue. In this study we aught to analyze the characteristics of the additional lesion found in preoperative breast MRI and to evaluate the clinicopathological factors in association with likelihood of having additional malignancy.

We retrospectively reviewed 2491 patients who undergone surgery due to breast cancer in Seoul National University Hospital(SNUH) between Jan 2006 and Dec 2010. Neoadjuvant chemotherapy cases, patients undergone initial sonography in other center or ones with prior excision were excluded and total 1068 patients were analyzed. The additional lesion was defined as the lesion not found in initial sonography and detected in preoperative breast MRI. The pathology of the additional lesion was reviewed and the association between the clinicopathologic factors and additional malignancy were evaluated. Accuracy of breast MRI was estimated regarding cancer yield, positive predictive value(PPV).

Mean age at diagnosis was 50.9 years (21 to 85 years). Overall detection rate of additional lesion was 26.2%(280 out of 1068). Mean size of the additional lesion was 9.8mm(3-51). Additional lesions consist of 99(35.4% of 280) C4 or higher, 174(62.1% of 280) below C4, 7(2.5% of 280) C0 lesions. Among them 100 patients undergone onstage surgery. 5(55% of 100) lesions were in ipsilateral breast and 45(45% of 100) in contralateral breast. Breast conserving surgery and mastectomy rate of the 100 onstage-operation group was 36% versus 64% and 64.6% versus 35.4% in total 1068 patients, showing no significant change of operation method of the primary cancer owing to additional lesion.

Among the 100 patients, 54(19.3% of 280) were benign, 3(1.1% of 280) were atypical ductal hyperplasia, 13(4.6% of 280) were in situ carcinoma, 19(6.8% of 280) were invasive carcinoma and 11(3.9% of 280) were unknown. Cancer yield was 2.99%(32 out of 1068) and PPV of preoperative breast MRI was 39.0%(31 out of 82).

In univariate analysis, young age and premenopausal patients showed to have higher rate of additional cancer found in MRI(p=0.022, p=0.036). Breast density, size and LN status of the primary cancer didn't show significancy and neither the hormone receptor status with each p value 0.705, 0.381, 0.973, 0.375 respectively. Lobular carcinoma(ILC or mixed IDC with ILC) and low grade carcinoma showed significancy of having additional malignancy (p=0.019, 0.022). In multivariate analysis age, low grade carcinoma and lobular carcinoma showed independent association with p value 0.014, 0.039, 0.035 respectively(HR 0.95, 95%CI:0.94 o 0.99),(HR 0.39, 95%CI:0.16 to 0.96),(HR 5.66, 95%CI:1.13 to 28.39).

Routine preoperative breast MRI use can result in overtreatment also with delay in surgical management. In our data, younger age, low grade carcinoma, lobular carcinoma showed independent association having additional malignant foci in breast MRI. With the basis of mammography and sonography, preoperative breast MRI should only be done when additional gain is considered to overcome the flaws.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-08-12.

[Screening and identification of microRNAs related to acquired gefitinib-resistance in lung adenocarcinoma cell lines]

背景与目的

肺腺癌吉非替尼获得性耐药严重影响了肺癌的治疗效果，microRNA在肺腺癌吉非替尼获得性耐药中的作用及其机制尚不清楚。本研究筛选与肺腺癌获得性吉非替尼耐药相关的microRNAs。

方法

以吉非替尼敏感肺癌细胞PC9与吉非替尼耐药肺癌细胞PC9/AB11为细胞模型，观察二者的形态学差异，流式细胞仪检测二者的细胞周期，计算它们的倍增时间，MTT法检测吉非替尼对两种细胞的IC₅₀，应用microRNA芯片检测和筛选与吉非替尼耐药相关的microRNAs，并进行real-time PCR验证。

结果

PC9细胞与PC9/AB11细胞形态差异明显，在细胞周期、倍增时间和吉非替尼对其的IC₅₀上均具有统计学差异。microRNA芯片结果显示，与PC9相比，耐药肺癌细胞株PC9/AB11中有4个microRNAs表达水平明显上调，有9个microRNAs表达水平明显下调。经real-time PCR验证，microRNA-138在PC9/AB11中表达明显下调，与芯片结果一致。

结论

PC9和PC9/AB11细胞株microRNA表达谱存在明显差异，初步筛选到了13个与肺腺癌吉非替尼耐药密切相关的microRNAs，为进一步深入研究microRNA在肺腺癌吉非替尼获得性耐药中的作用及其分子机制提供了实验依据和理论基础。

Dickkopf-1 is involved in invasive growth of esophageal cancer cells

Dickkopf-1 (DKK1) is an inhibitor of Wnt/β-catenin signaling pathway. High levels of DKK1 protein were found in a series of cancers. However, the role of DKK1 in the progression of esophageal carcinoma is not fully understood. In the present study, RT-PCR and Western blot were used to detect the expression of DKK1 in esophageal carcinoma tissues, matched adjacent normal esophageal tissues, and esophageal carcinoma cell lines. Our results showed that the expression of DKK1 was upregulated on both mRNA and protein levels in esophageal carcinoma tissues compared with the adjacent normal esophageal tissues, meanwhile, in four esophageal carcinoma cell lines analyzed, expression of DKK1 was detected with different levels. Immunohistochemistry and immunofluoresence revealed that the distribution of DKK1 was mainly in the cytoplasm in both carcinoma tissues and cell lines. To further explore the biological effects of DKK1 on proliferation, cell cycle and invasion capability, we constructed the eukaryotic expression vector pCMV-Tab-2b-DKK1 which can effectively overexpress DKK1. Subsequently, we observed that exogenous expression of DKK1 in EC9706 cell line resulted in an increased rate of proliferation, and S stage and G2/M stage ratio whereas G0/G1 ratio was decreased. In order to evaluate the invasion capability Boyden chamber was analyzed which implied that overexpression of DKK1 resulted in an increase in the invasion ability in EC9706 cell line. Taken together, the study indicates that DKK1 might be a key regulator in the progression of esophageal carcinoma and a potential therapeutic target in esophageal carcinoma.

[Meta analysis of association between Ser326Cys polymorphism of hOGG1 gene and risk of lung cancer]

背景与目的

就全世界范围内而言，肺癌是一种常见疾病。人8-羟基鸟嘌呤糖苷酶（human 8-hydroxyguanine glycosylase, hOGG1）是一种DNA修复酶，它能特异切除8-羟基鸟嘌呤（8-dihydro-8-oxoguanine, 8-OH-G），对损伤的DNA进行修复。hOGG1 Ser326Cys基因多态性与癌症易感性的关系一直是研究的热点，而该多态性与肺癌易感性的关系尚存在争议。本研究采用meta分析旨在更好地探讨hOGG1 Ser326Cys多态性与肺癌易感性之间的关系。

方法

使用MEDLINE数据库检索2010年11月以前的相关文献，按照纳入标准，全面搜索含有研究hOGG1 Ser326Cys多态性与肺癌易感性相关的信息。由至少两位评论员做独立文献筛选和资料提取，并交叉审核。使用STATA 10.1软件进行统计分析。

结果

根据检索条件，共有22篇文献（包括8, 575例肺癌患者和9, 484名正常对照个体）被纳入当前的meta分析。分析结果表明22项研究的结果存在明显异质性，当排除不符合Hard-Weinberg平衡定律的两篇文献后，其余的文献呈现出较好的同质性。与hOGG1 Ser326相比，Cys326基因型明显增加了肺癌发病风险（OR=1.24, 95%CI:1.10-1.39, P < 0.001）。这种正相关在亚洲人群和医院来源的样本中尤为明显（OR=1.28, 95%CI: 1.11-1.49; OR=1.26, 95%CI: 1.09-1.46）。

结论

hOGG1 Ser326Cys多态性与肺癌易感性之间存在明显相关性，Cys326基因型能明显增加肺癌发病风险。