油松遗传结构与地理阻隔因素的相关性

油松(Pinus tabulaeformis)是我国特有广布树种。秦岭是我国亚热带和暖温带气候的重要分界线,贺兰山是我国西北干旱区与半干旱区的分界线。旨在以分布于秦岭、贺兰山和晋陕两省的10个天然油松种群为研究对象,通过对其线粒体DNA(nad1和matR内含子)的序列,探讨地理阻隔对油松遗传结构的影响。结果表明,10个天然油松种群的100个个体中共检测到27个单倍型,多态位点172个,简约信息位点35个,单一多态性位点137个。其中1个单倍型为全部种群共有,4个单倍型为2-5个种群共有,其余22个单倍型为各个种群所独有。在这10个种群中,有8个种群分别具有1-4个独有单倍型。尽管秦岭南侧种群和北侧种群分别具有两个和一个独有单倍型; 贺兰山东侧种群和西侧种群均具有3个独有单倍型;但是与晋陕种群(即油松分布区中心种群)相比,其种群独有单倍型平均数目则明显较少。与此同时,不仅秦岭南北两侧或贺兰山东西两侧种群的独有单倍型的进化关系往往较近,而且秦岭北侧或贺兰山东侧种群的独有单倍型与油松分布区中心种群的某些独有单倍型的关系亦较近。从而导致秦岭南北两侧或贺兰山东西两侧种群与油松分布区中心种群之间表现出比较复杂的聚类关系。由此可见,油松的遗传结构与山脉屏障的存在没有明显关系。     

HMGB1 enhances embryonic neural stem cell proliferation by activating the MAPK signaling pathway

Neural stem cells (NSCs) are involved in neural tube formation. As the high-mobility group box 1 (HMGB1) protein is involved in neurulation and is present at elevated levels in neural tube defects (NTDs) induced by hyperthermia, we have now investigated the effects of HMGB1 on proliferation, differentiation, and MAPK signaling pathways of NSCs in vitro. We constructed a lentivirus vector with HMGB1 siRNA and used it to infect NSCs. Down-regulation of HMGB1 expression was confirmed. Proliferation of NSCs was determined by MTS and nestin/BrdU double-labeling. Differentiation of NSCs was assessed using β-tubulinIII and GFAP. Knockdown of HMGB1 significantly suppressed NSC proliferation but hardly affected differentiation, which was regulated by decreased expression of MAPK signaling pathways. Thus, HMGB1 has beneficial effects on neurulation and may serve as a new target for the prevention of NTDs.     

Salinomycin induces cell death with autophagy through activation of endoplasmic reticulum stress in human cancer cells

Salinomycin is perhaps the first promising compound that was discovered through high throughput screening in cancer stem cells. This novel agent can selectively eliminate breast and other cancer stem cells, though the mechanism of action remains unclear. In this study, we found that salinomycin induced autophagy in human non-small cell lung cancer (NSCLC) cells. Furthermore, we demonstrated that salinomycin stimulated endoplasmic reticulum stress and mediated autophagy via the ATF4-DDIT3/CHOP-TRIB3-AKT1-MTOR axis. Moreover, we found that the autophagy induced by salinomycin played a prosurvival role in human NSCLC cells and attenuated the apoptotic cascade. We also showed that salinomycin triggered more apoptosis and less autophagy in A549 cells in which CDH1 expression was inhibited, suggesting that the inhibition of autophagy might represent a promising strategy to target cancer stem cells. In conclusion, these findings provide evidence that combination treatment with salinomycin and pharmacological autophagy inhibitors will be an effective therapeutic strategy for eliminating cancer cells as well as cancer stem cells.     

磷酸化的JNK和p38在高温致神经管畸形上皮细胞中的表达变化

目的 探讨高温致神经管畸形（neural tube defects,NTD）的分子机制,为防治神经管畸形提供理论依据.方法 利用高温致金黄地鼠NTD动物模型,应用免疫荧光染色技术,观察NTD发生过程中磷酸化c-Jun氨基末端活化蛋白激酶（p-JNK）和磷酸化p38（p-p38）在胚胎神经管上皮的表达变化.结果 p-JNK和p-p38的免疫阳性产物表达于胚胎神经管上皮细胞及其周围间充质细胞的胞浆中,高温后不同时间点胚胎神经管上皮细胞内的p-JNK和p-p38的表达量均较对照组减弱.结论 磷酸化JNK和p38参与了神经管的正常发育,其表达量降低可能是高温致NTD发生的重要途径之一.     

Down-regulation of cellular FLICE-inhibitory protein (Long Form) contributes to apoptosis induced by Hsp90 inhibition in human lung cancer cells

Background

Breast cancer is the most common cancer in the Arab world and it ranked first among Saudi females. Doxorubicin (DOX), an anthracycline antibiotic is one of the most effective anticancer agents used to treat breast cancer. chronic cardiotoxicity is a major limiting factor of the use of doxorubicin. Therefore, our study was designed to assess the role of a natural product resveratrol (RSVL) on sensitization of human breast cancer cells (MCF-7) to the action of DOX in an attempt to minimize doxorubicin effective dose and thereby its side effects.

Methods

Human breast cancer cell line MCF-7, was used in this study. Cytotoxic activity of DOX was determined using (sulforhodamine) SRB method. Apoptotic cells were quantified after treatment by annexin V-FITC- propidium iodide (PI) double staining using flow-cytometer. Cell cycle disturbance and doxorubicin uptake were determined after RSVL or DOX treatment.

Results

Treatment of MCF-7 cells with 15 μg/ml RSVL either simultaneously or 24 h before DOX increased the cytotoxicity of DOX, with IC50 were 0.056 and 0.035 μg/ml, respectively compared to DOX alone IC50 (0.417 μg/ml). Moreover, flow cytometric analysis of the MCF-7 cells treated simultaneously with DOX (0.5 μg/ml) and RSVL showed enhanced arrest of the cells in G₀ (80%). On the other hand, when RSVL is given 24 h before DOX although there was more increased in the cytotoxic effect of DOX against the growth of the cells, however, there was decreased in percentage arrest of cells in G₀, less inhibition of DOX-induced apoptosis and reduced DOX cellular uptake into the cells.

Conclusion

RSVL treatment increased the cytotoxic activity of DOX against the growth of human breast cancer cells when given either simultaneously or 24 h before DOX.     

Expression of Bcl-2, Bax and Caspase-3 in Nerve Tissues of Rats Chronically Exposed to 2,5-hexanedione

Occupational exposure and experimental intoxication with n-hexane or its metabolite 2,5-hexanedione (HD) produce a central-peripheral neuropathy. However, the mechanism remains unknown. We hypothesized that HD affected the expression of Bcl-2, Bax and Caspase-3 in the central nervous system (CNS) and the peripheral nervous system (PNS). Male adult Wistar rats were administered by intraperitoneal injection at a dosage of 200 or 400 mg/kg HD, five days per week for 8 weeks. Samples of the cerebral cortex, cerebellum, spinal cord and sciatic nerves were collected and examined for Bcl-2, Bax and Caspase-3 expression using Western blotting. Subchronic exposure to HD resulted in significantly increased expression of both anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bax and Caspase-3 in cerebral cortex and cerebellum, which exhibited a dose-dependent pattern. Though little change was detected in spinal cord, our results showed that the expression of Bcl-2, Bax and Caspase-3 was markedly enhanced in the sciatic nerves. These findings suggested that the changes of apoptosis-related protein level in rat nerve tissues were associated with the intoxication of HD, which might be involved in early molecular regulatory mechanism of apoptosis in the HD-induced neuropathy.     

Nogo-B promotes invasion and metastasis of nasopharyngeal carcinoma via RhoA-SRF-MRTFA pathway

Distant metastasis remains the major cause for treatment failure in patients with nasopharyngeal carcinoma (NPC). Thus, it is necessary to investigate the underlying regulation mechanisms and potential biomarkers for NPC metastasis. Nogo-B (neurite outgrowth inhibitor B), encoded by reticulon-4, has been shown to be associated with the progression and advanced stage of several cancer types. However, the relationship between Nogo-B and NPC remains unknown. In this study, we found that higher expression of Nogo-B was detected in NPC cells and tissues. Higher expression of Nogo-B was statistically relevant to N stage, M stage, and poor prognosis in NPC patients. Further functional investigations indicated that Nogo-B overexpression could increase the migration, invasion, and metastasis ability of NPC cells in vitro and in vivo. Mechanistically, Nogo-B promoted epithelial-mesenchymal transition (EMT) and enhanced the invasive potency by interacting directly with its receptor NgR3 in NPC. Additionally, overexpression of Nogo-B could upregulate the protein levels of p-RhoA, SRF, and MRTFA. A positive relationship was found between the expression of Nogo-B and the p-RhoA in NPC patients as well as in mouse lung xenografts. Nogo-B^high p-RhoA^high expression was significantly associated with N stage, M stage, and poor prognosis in NPC patients. Notably, CCG-1423, an inhibitor of the RhoA-SRF-MRTFA pathway, could reverse the invasive potency of Nogo-B and NgR3 in NPC cell lines, and decrease the expression of N-Cadherin, indicating that CCG-1423 may be a potential target drug of NPC. Taken together, our findings reveal that Nogo-B enhances the migration and invasion potency of NPC cells via EMT by binding to its receptor NgR3 to regulate the RhoA-SRF-MRTFA pathway. These findings could provide a novel insight into understanding the metastasis mechanism and targeted therapy of advanced NPC.Subject terms: Head and neck cancer, Drug discovery     

miR-96 downregulates RECK to promote growth and motility of non-small cell lung cancer cells

MicroRNAs play critical roles in the development and progression of non-small cell lung cancer (NSCLC). miR-96 acts as an oncogene in some malignancies, while its role in NSCLC is unclear. Here, we validated that miR-96 was significantly increased in both human NSCLC tissues and cell lines. Inhibition of miR-96 expression remarkably reduced cell proliferation, colony formation, migration, and invasion of NSCLC cells. Reversion-inducing-cysteine-rich protein with kazal motifs (RECK) was identified as a target of miR-96 in NSCLC cells. In addition, the expression of RECK was found to be negatively correlated with the expression of miR-96 in NSCLC tissues. Our data suggest that miR-96 might promote the growth and motility of NSCLC cells partially by targeting RECK.     

橄榄ISSR-PCR反应体系的优化

采用正交设计和单因素试验,以BDB(CA)7为引物,对ISSR-PCR扩增橄榄基因组DNA的主要影响因子进行了筛选和分析,优化了适宜于橄榄ISSR-PCR的扩增体系。结果表明,20μL的反应体系中采用40ng的模板DNA,0.2mmol/LdNTPs,0.25μmol/LISSR引物、1UTaq聚合酶,以及51.6℃-53℃的复性温度为橄榄ISSR-PCR扩增的最优条件。