[Advances in the relationship between tumor cell metabolism and tumor metastasis]

Intracellular nutrients and the rate of energy flowing in tumor cells are often higher than that in normal cells due to the prolonged stress of tumor-specific microenvironment. In this context, the metabolism of tumor cells provides the fuel of bio-synthesis and energy required for tumor metastasis. Consistent with this, the abnormal metabolism such as extremely active glucose metabolism and excessive accumulating of fatty acid is also discovered in metastatic tumors. Previous Studies have confirmed that the regulation of tumor metabolism can affect the tumor metastasis, and some of these have been successfully applied in clinical effective, positive way. Thus, targeting metabolism of tumor cells might be an effectively positive way to prevent the metastasis of tumor. So, our review is focused on the research development of the relationship between tumor metabolism and metastasis as well as the underlying mechanism.

MiR-449a suppresses cell invasion by inhibiting MAP2K1 in non-small cell lung cancer

Increasing evidence reveals that deregulation of miRNAs contributes to carcinogenesis of the human non-small cell lung cancer (NSCLC). Our study discovered that the expression of miR-449a was markedly decreased in NSCLC cells with high metastatic capacity and tissues of positive lymph node metastasis. Moreover, our results showed that miR-449a could act as a tumor suppressor by inhibiting the invasion of NSCLC cells in vitro and in vivo. Mechanistically, miR-449a inhibited the expression of MAP2K1 by direct targeting its 3'UTR, and regulated the activity of MEK1/ERK1/2/c-Jun pathway through an auto-regulatory feedback loop. Furthermore, the histone methylation mediated the decreased expression of miR-449a through SUZ12. Taken together, the novel connection between miR-449a and MAP2K1 demonstrated here provided a new, potential therapeutic target for the treatment of non-small cell lung cancer.

Financial burden on the families of patients with hepatitis B virus-related liver diseases and the role of public health insurance in Yunnan province of China

OBJECTIVE

To investigate the financial burden of patients who had various stages of hepatitis B virus-related diseases and the level of alleviation from financial burden by health insurance schemes in Yunnan province of China.

STUDY DESIGN

A cross-sectional survey.

METHODS

Patients' information was consecutively recorded at the First Affiliated Hospital of Kunming Medical University, from December 2012 to June 2013. Consecutive cases of hepatitis B virus (HBV) (520), compensated cirrhosis (91), decompensated cirrhosis (198) and hepatocellular carcinoma (HCC) (131) were recruited from the outpatient and inpatient departments. The total direct costs, hospital charge, outpatient costs, hospitalization fees being reimbursed and household catastrophic health expenditure were estimated for each disease group.

RESULTS

The average annual direct costs for each disease group were 19,496 RMB for HBV, 28,466 RMB in compensated cirrhosis, 46,061 RMB for decompensated cirrhosis, and 33,044 RMB for HCC patients. Catastrophic health expenditure occurred in all four groups. Health insurance reimbursement released the financial burden incurred by medical expenses of patients under a high level of household economic status. Public health insurance schemes helped the patients to various extents.

CONCLUSIONS

Among these patient groups, direct costs represent a significant economic burden. Health expenditure and financing systems must be considered to prevent the increase of household catastrophe, particularly among the poor.

[A meta-analysis of Association between MGMT gene promoter methylation and non-small cell lung cancer]

背景与目的

抑癌基因启动子区域甲基化是基因失活的重要机制之一, 本研究采用meta分析的方法探讨非小细胞肺癌(non-small cell lung cancer, NSCLC)患者癌组织与自身对照组织(血浆、正常肺组织及支气管灌洗液)MGMT基因启动子甲基化率有无差别。

方法

计算机检索Medline、EMBASE、CNKI及万方等数据库, 收集公开发表的涉及MGMT基因启动子甲基化与NSCLC关系的临床研究。采用meta分析的方法比较NSCLC患者癌组织与正常自身对照组织中MGMT基因启动子甲基化率有无差别。

结果

15篇文献符合纳入标准并纳入本研究, NSCLC患者肺癌组织中MGMT基因启动子甲基化率为38%(95%CI:23%-53%); NSCLC患者正常肺组织、血浆和支气管灌洗液中MGMT基因启动子甲基化率分别为16%(95%CI:5%-27%)、23%(95%CI:10%-34%)和39%(95%CI:23%-55%)。与正常肺组织和血浆比较, 肺癌中MGMT基因启动子甲基化率增高(OR=3.98, 95%CI:2.71-5.84, P < 0.05)(OR=1.88, 95%CI:1.16-3.05, P < 0.05), 与支气管灌洗液比较差别无统计学意义(OR=2.05, 95%CI:0.88-4.78, P > 0.05)。

结论

NSCLC患者肺癌组织中MGMT基因启动子甲基化率增高, 该基因的启动子甲基化与肺癌的发生可能存在相关性。

Pazopanib diminishes non-small cell lung cancer (NSCLC) growth and metastases in vivo

Background

Anti-angiogenesis has been demonstrated to have a critical role in lung cancer pathogenesis. Here, we characterized the effect of the small-molecule angiogenesis inhibitor pazopanib on non-small cell lung cancer (NSCLC) cells.

Methods

NSCLC cells were tested for viability and migration after incubation with varying concentrations of pazopanib. Further, the phosphorylation status of extracellular signal-regulated kinase, protein kinase B, and MEK were assessed in vitro. For in vivo testing, mice grafted with NSCLC cell lines L9981 and A549 were treated orally with pazopanib.

Results

Pazopanib inhibits signaling pathways in tumor cells, thus blocking NSCLC cell growth and migration in vitro and inducing tumor cell arrest at G0/G1 phase. We show that pazopanib could inhibit tumor cell growth, decrease metastases, and prolong survival in two mouse xenograft models of human NSCLC.

Conclusion

These preclinical studies of pazopanib show the possibility of clinical application and, ultimately, improvement in patient outcome.

[MiR-192 confers cisplatin resistance by targeting Bim in lung cancer]

背景与目的

顺铂是非小细胞肺癌化疗的一线药物，但获得性耐药限制了其疗效的发挥。本研究的目的是筛选鉴定与肺癌顺铂耐药相关的microRNAs，探讨其与肺癌顺铂耐药的影响及分子机制。

方法

应用miRNA芯片及RT-PCR筛选鉴定A549与A549DDP肺癌细胞间的差异表达miRNAs，将差异表达miR-192转染A549和A549DDP细胞株，CCK-8检测miR-192对半数抑制浓度（half inhibition concentration, IC₅₀）的影响，流式细胞术检测细胞凋亡，生物软件预测及双荧光素酶报告基因法寻找miR-192的靶基因，RT-PCR及Western blot检测靶基因表达水平在转染前后的变化。

结果

MiR-192在A549DDP中显著高表达，表达量是A549细胞表达量的37.59±0.35倍。在低表达miR-192的A549细胞中过表达miR-192，细胞对顺铂的IC₅₀显著增高，顺铂引起的细胞凋亡率显著降低；反之，在高表达miR-192的A549DDP中抑制miR-192的表达，顺铂的IC₅₀显著降低，顺铂引起的细胞凋亡率显著增加。miR-192可靶向作用促凋亡基因Bim的3’-UTR，并在转录后水平负向调控Bim的表达。

结论

MiR-192通过靶向负调控促凋亡基因Bim表达，诱导肺腺癌细胞株A549产生顺铂耐药，并减少顺铂引起的细胞凋亡。

Abstract 21: Quantitative FRET technology for SUMOylation cascade and high-throughput screening assay for SUMOylation inhibitor in cancer drug discovery

The ubiquitin–proteasome system and ubiquitin-like protein pathways, such as SUMOylation, are critical in protein homeostasis and activities in vivo and are emerging as a new strategy to treat many acute and chronic human diseases, such as cancers. Although various kinase inhibitors have been developed as target-based therapy, solid tumors are still challenges in clinical therapy because various resistant are developed after kinase inhibitor treatments, and therapeutic agents with novel mechanisms are urgently needed. SUMO has been shown to modify various critical proteins, such as p53, MDM2, Estrogen receptor and androgen receptors. More recently, a genome-wide siRNA screening shown that inhibition of SUMO E1 ligases can lead to synergistically lethality of c-Myc overexpressed breast cancer cells. However, so far, specific inhibitor of SUMOylation is still not available for the community.

Fig. 1. SUMOylation in human diseases and quantitative systems biology approach for basic and translational research of SUMOylation. We developed a novel quantitative Förster resonance energy transfer (FRET) technology platform for both basic kinetics parameter determinations and high-through screening(HTS) assays for SUMOylation cascade. The novel theoretical and experimental procedures for protein interactions affinity(Kd) determinations in the SUMOylation cascade, including the interaction between SUMO1 and its E2 ligase, Ubc9, E1 heterodimers(Aos1 and Uba2), E1 and E2 interactions(Uba2 and Ubc9), and E2 and substrate interactions(Ubc9 and RanGap1c) and protease kinetics, Kcat/KM of SENP1 endopeptidase activity have been developed in a systems biology manner. The data are in good agreement with traditional methods. Multiple FRET-based HTS assays have also been developed and HTS campaigns have led to very promising hit that can preferentially kill Non-small cell lung cancer cells. The novel SUMOylation inhibitor can be used for cancer treatments by synergistically lethality strategy.

Citation Format: Jiayu Liao, Hilda Wiryawan, Yang Li, Yang Song, Yan Liu, Jiacong You, Ling Jiang, Harbani Kaur Malik, Amanda N. Saavedra, Sophie Qu. Quantitative FRET technology for SUMOylation cascade and high-throughput screening assay for SUMOylation inhibitor in cancer drug discovery. [abstract]. In: Proceedings of the AACR Special Conference: Cancer Susceptibility and Cancer Susceptibility Syndromes; Jan 29-Feb 1, 2014; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(23 Suppl):Abstract nr 21. doi:10.1158/1538-7445.CANSUSC14-21

Decline in intrahepatic cccDNA and increase in immune cell reactivity after 12 weeks of antiviral treatment were associated with HBeAg loss

Viral load reduction facilitates recovery of antiviral T-cell responses. Dynamic alterations in intrahepatic viraemia clearance and immune cell reactivity during the early phase of nucleoside analogue (NA) therapy and the impact of these changes on HBeAg seroconversion are unknown. Fifteen HBeAg-positive chronic hepatitis B (CHB) patients were treated with adefovir dipivoxil. T-cell reactivity to HBV core and surface antigens were tested using ELISPOT assay from baseline to week 48 post-treatment (at 4-week intervals). Before and at week 12 of treatment, paired liver biopsies were analysed for intrahepatic HBV-DNA and cccDNA via real-time fluorescent PCR. In situ detection of CD4(+) , CD8(+) T cells and NK cells was analysed by immunohistochemistry. With viral load reduction, HBV-specific IFN-γ-producing CD4(+) T cells in patients with HBeAg loss were greatly enhanced and reached the highest level at week 12, with further increase observed between week 36 and week 48. After 12 weeks of treatment, total intrahepatic HBV-DNA and cccDNA had significantly decreased; however, there was no difference in the viral loads or extent of reduction between patients with and without HBeAg loss. Paralleling reduction in viral load, intrahepatic CD8(+) T lymphocytes increased in patients with HBeAg loss compared with baseline values. Only one patient without HBeAg loss exhibited similar results. Increased immune cells were observed in certain patients along with reduced hepatic viral loads during the second phase of HBV-DNA decline, which could promote the recovery of antiviral immunity and facilitate HBeAg loss.

Systematic review with network meta-analysis: adjuvant therapy for resected biliary tract cancer

BACKGROUND

Major adjuvant therapies for biliary tract cancer (BTC) include fluorouracil, gemcitabine and chemoradiation (CRT), but the optimum regimen remains inconclusive.

AIM

To compare these therapies in terms of patient survival rates after resection and toxic effects.

METHODS

We searched PubMed for controlled trials comparing the above three therapies with each other or observation alone until 31 January 2014. We estimated the hazard ratios (HRs) for death and odds ratios (ORs) for toxic effects among different therapies. Subgroup analyses based on positive lymph node or resection margin were also performed.

RESULTS

Twelve eligible articles were included. Gemcitabine improved 5-year survival (HR 2.12, 95% CI, confidence interval 1.23-4.02, P = 0.01), whereas fluorouracil (HR 1.61, 95% CI 0.74-3.67) and CRT (HR 1.55, 95% CI 0.82-3.32) provided a poorer survival outcome compared with gemcitabine after 1 year. Similarly, for 5-year survival rates, although differing, CRT did not provide a significant improvement in survival (HR 0.46, 95% CI 0.20-0.97) compared with gemcitabine. Fluorouracil did not appear to provide benefit over gemcitabine (HR 1.56, 95% CI 0.77-3.35). CRT was ranked highest for toxic effects including haematological (OR 5.45, 95% CI 0.01-483.85) and nonhaematological (OR 5.77, 95% CI 0.01-3807.40).

CONCLUSIONS

Chemotherapy with gemcitabine is the optimum adjuvant treatment with a balanced benefit-toxicity ratio for resected biliary tract cancer. Chemoradiation was more likely to cause toxic effects.

BRD4 regulates Nanog expression in mouse embryonic stem cells and preimplantation embryos

Bromodomain-containing protein 4 (BRD4) is an important epigenetic reader implicated in the pathogenesis of a number of different cancers and other diseases. Brd4-null mouse embryos die shortly after implantation and are compromised in their ability to maintain the inner cell mass, which gives rise to embryonic stem cells (ESCs). Here we report that BRD4 regulates expression of the pluripotency factor Nanog in mouse ESCs and preimplantation embryos, as well as in human ESCs and embryonic cancer stem cells. Inhibition of BRD4 function using a chemical inhibitor, small interfering RNAs, or a dominant-negative approach suppresses Nanog expression, and abolishes the self-renewal ability of ESCs. We also find that BRD4 associates with BRG1 (brahma-related gene 1, aka Smarca4 (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a, member 4)), a key regulator of ESC self-renewal and pluripotency, in the Nanog regulatory regions to regulate Nanog expression. Our study identifies Nanog as a novel BRD4 target gene, providing new insights for the biological function of BRD4 in stem cells and mouse embryos. Knowledge gained from these non-cancerous systems will facilitate future investigations of how Brd4 dysfunction leads to cancers.

MiR-132 suppresses the migration and invasion of lung cancer cells via targeting the EMT regulator ZEB2

MicroRNAs (miRNAs) are small, non-coding RNAs which can function as oncogenes or tumor suppressor genes in human cancers. Emerging evidence reveals that deregulation of miRNAs contributes to the human non-small cell lung cancer (NSCLC). In the present study, we demonstrated that the expression levels of miR-132 were dramatically decreased in examined NSCLC cell lines and clinical NSCLC tissue samples. Then, we found that introduction of miR-132 significantly suppressed the migration and invasion of lung cancer cells in vitro, suggesting that miR-132 may be a novel tumor suppressor. Further studies indicated that the EMT-related transcription factor ZEB2 was one direct target genes of miR-132, evidenced by the direct binding of miR-132 with the 3' untranslated region (3' UTR) of ZEB2. Further, miR-132 could decrease the expression of ZEB2 at the levels of mRNA and protein. Notably, the EMT marker E-cadherin or vimentin, a downstream of ZEB2, was also down-regulated or up-regulated upon miR-132 treatment. Additionally, over-expressing or silencing ZEB2 was able to elevate or inhibit the migration and invasion of lung cancer cells, parallel to the effect of miR-132 on the lung cancer cells. Meanwhile, knockdown of ZEB2 reversed the enhanced migration and invasion mediated by anti-miR-132. These results indicate that miR-132 suppresses the migration and invasion of NSCLC cells through targeting ZEB2 involving the EMT process. Thus, our finding provides new insight into the mechanism of NSCLC progression. Therapeutically, miR-132 may serve as a potential target in the treatment of human lung cancer.