Notice for Contributors of Cell Research

Aims and scopesCell Research, a peer-reviewed journal that publishes worldwide new original achievements articles of basic research in English, plus reviews, features and special report or analyses of current research in Cell and Molecular Biology, aims to the promotion of scientific exchanges between China and all other parts of the world. Our offices in Shanghai, Bethesda, MD, Piscataway, N.I, Toronto, Oxford and London welcome submissions from scientists of all parts in the world.     

A Special Issue on Stem Cell Research

Stem cells possess the remarkable ability of extensive self-renewal and differentiation into specific celllineages,and they play essential roles in development and adult tissue homeostasis.Due to their criticalimportance in normal physiology and the promise for use in regenerative medicine to treat a variety ofdiseases,stem cells have attracted extensive research interest in recent years.As China's premium in-ternational journal with a broad scope in cell and molecular biology,Cell Research has witnessed moreand more submissions on stem cell research.Indeed,along with the traditional strengths of the journal inmolecular immunology,cancer biology,and plant molecular physiology,stem cell research has graduallyand naturally evolved into a new growth point of Cell Research.Reflecting the growing interest of bothour readers and authors in this exciting and expanding field,we are pleased to present this Special Issueon Stem Cell Research.     

Cancer research in China： a Special Focus by Cell Research

The year of 2007 is the 100th anniversary of the American Association for Cancer Research （AACR）, ＂marking a century of progress in saving lives through cancer research＂ （quote from the AACR website）. Despite the great progress, cancer remains a top threat to human health. Continued research will be essential to winning the battle against cancer, as only through continued research would it be possible to gain better understandings, generate deeper insights, uncover new preventive and therapeutic strategies, design and test more effective treatments, and ultimately, save more lives.     

Advancement on techniques for the separation and maintenance of the red imported fire ant colonies

Advancement has recently been made on the techniques for separating and maintaining colonies of red imported fire ants, Solenopsis invicta Buren. A new brood rescue method significantly improved the efficiency in separating colony from mound soil. Furthermore, a new method was developed to separate brood from the colony using fire ant repellants. Finally, a cost-effective method was developed to coat containers with diluted Fluon （AGC Chemicals America, Inc, Moorestown, NJ, USA）, an aqueous polytetrafluoroethylene, to prevent housed ants from escaping a container. Usually the original Fluon solution is directly applied to the wall of the containers. Reduced concentrations of Fhion were found to be equally effective in preventing ant escape. The use of diluted Fluon solutions to coat the containers was recommended because of environmental and cost-saving benefits. Application of these new techniques can significantly reduce labor, cost and environmental contamination. This review paper collates all the new techniques in one reference which readers can use as a manual.     

AIDS Research and Its Role in China＇s AIDS Prevention and Control Policies

By the end of 2005, the estimated number of HIV infected people in China was 650,000. The seriousness of the epidemic calls for effective control measures to tackle the problems in order to avoid the tragedy in Africa from happening in China. ＂Prevention First＂ is the cornerstone of the country＇s health policy. On 2003 World AIDS Day, Premier Jiabao Wen announced a new national AIDS control policy, ＂Four Frees and One Care＂. This policy clearly shows that the Chinese government has once again taken full responsibility to solve public health problems and has profound impact far beyond the AIDS field. In early 2006, the central government put scientific and technology innovation as a national priority and set the target to build an innovative China by year 2020. Since then, the government has been increasing investment in science and technology with major emphasis on both infectious diseases control and new drug research and development. For the first time, development of 100 new drugs and control of major infectious diseases （AIDS, HBV, TB and other emerging infectious diseases） have been selected as national key scientific projects. China＇s best minds in related fields will be pooled to work together in order to remove the technical barriers blocking efficient control of the major infectious disease in China. Knowledge on molecular epidemiology, immunology, pathogenesis, HAART, as well as HIVDR strains will certainly provide urgently needed scientific information for China＇s AIDS control program. Only evidence-based strategy from good research will provide long-term effective control of AIDS.     

Pollen Tube Growth： a Delicate Equilibrium Between Secretory and Endocytic Pathways

Although pollen tube growth is a prerequisite for higher plant fertilization and seed production, the processes leading to pollen tube emission and elongation are crucial for understanding the basic mechanisms of tip growth. It was generally accepted that pollen tube elongation occurs by accumulation and fusion of Golgi-derived secretory vesicles （SVs） in the apical region, or clear zone, where they were thought to fuse with a restricted area of the apical plasma membrane （PM）, defining the apical growth domain. Fusion of SVs at the tip reverses outside cell wall material and provides new segments of PM. However, electron microscopy studies have clearly shown that the PM incorporated at the tip greatly exceeds elongation and a mechanism of PM retrieval was already postulated in the mid-nineteenth century. Recent studies on endocytosis during pollen tube growth showed that different endocytic pathways occurred in distinct zones of the tube, including the apex, and led to a new hypothesis to explain vesicle accumulation at the tip; namely, that endocytic vesicles contribute substantially to V-shaped vesicle accumulation in addition to SVs and that exocytosis does not involve the entire apical domain. New insights suggested the intriguing hypothesis that modulation between exo- and endocytosis in the apex contributes to maintain PM polarity in terms of lipid/protein composition and showed distinct degradation pathways that could have different functions in the physiology of the cell. Pollen tube growth in vivo is closely regulated by interaction with style molecules. The study of endocytosis and membrane recycling in pollen tubes opens new perspectives to studying pollen tube-style interactions in vivo.     

Current Status of Targets and Assays for Anti-HIV Drug Screening

HIV/AIDS is one of the most serious public health challenges globally. Despite the great efforts that are being devoted to prevent,treat and to better understand the disease,it is one of the main causes of morbidity and mortality worldwide. Currently,there are 30 drugs or combinations of drugs approved by FDA. Because of the side-effects,price and drug resistance,it is essential to discover new targets,to develop new technology and to find new anti-HIV drugs. This review summarizes the major targets and assays currently used in anti-HIV drug screening.     

A New Species of Trimeresurus Lacépède, 1804(Squamata: Viperidae) from Southwestern China,Vietnam, Thailand and Myanmar

The pit vipers of the genus Trimeresurus Lacépède, 1804 is one of the largest groups of Asian snakes, distributed from India to China and Indonesia. Recent surveys in Jiangcheng and Simao, Yunnan Province, China resulted in a new species previously allocated to T. albolabris. Combining morphological and molecular data, we describe it as Trimeresurus guoi sp. nov. The new species morphologically differs from T. albolabris in the yellow green ventral color; an indistinct ventrolateral line; the a bsence of a postocular stripe; the firebrickred iris; a dark red stripe on dorsal tail; hemipenes with relatively weak sparse papillae, reaching 23 rd subcaudal when unextruded. Molecularly, the new species forms a clearly divergent lineage(BPP 1.00/UFB 100). Uncorrected pairwise distances of mitochondrial gene Cyt b between the new species and other known species of the subgenus Trimeresurus range from 0.052(T. albolabris) to 0.071(T. insularis).     

Global analysis of non-coding small RNAs in Arabidopsis in response to jasmonate treatment by deep sequencing technology

In plants, non-coding small RNAs play a vital role in plant development and stress responses. To explore the possible role of non-coding small RNAs in the regulation of the jasmonate (JA) pathway, we compared the non-coding small RNAs between the JA-deficient aos mutant and the JA-treated wild type Arabidopsis via high-throughput sequencing. Thirty new miRNAs and 27 new miRNA candidates were identified through bioinformatics approach. Forty-nine known miRNAs (belonging to 24 families), 15 new miRNAs and new miRNA candidates (belonging to 11 families) and 3 tasiRNA families were induced by JA, whereas 1 new miRNA, 1 tasiRNA family and 22 known miRNAs (belonging to 9 families) were repressed by JA.     

羟基脲对人红白血病细胞株中球蛋白基因表达和细胞分化的影响

人红白血病细胞株（ＨＥＬ细胞）中珠蛋白基因表达具有自己的特点。即只表达胚胎型的γ－珠蛋白基因而不表达成人型的β－珠蛋白基因。羟基脲是一种抑制ＤＮＡ的小分子有机化合物。它在临床上被用来治疗地中海盆血和镰刀型贫血。我们的实验结果表明：胡羟基脲浓度增加ＨＥＬ细胞增殖速度减慢。用常规ＲＴ－ＰＣＲ方法和定量ＰＣＲ分析证明,用羟基脲诱导ＨＥＬ细胞后,β－珠蛋白基因表达增加,α－珠蛋白基因表达减少,而γ－珠蛋白     

黄芪汤对延缓C离子辐射致大鼠肾组织细胞凋亡的影响及相关机制

目的: 探讨黄芪汤抑制¹²C⁶⁺离子辐射脑模型鼠肾组织细胞凋亡的分子保护机制。方法: 50只SPF级Wistar大鼠随机分为正常对照组,单纯辐射模型组,黄芪汤(高、中、低剂量)组。正常对照组和单纯辐射模型组给予等体积生理盐水灌胃10 ml/(kg·d),黄芪汤治疗组分别灌胃给予黄芪汤18、9、4.5 g/(kg·d),连续给药2周。7 d后除正常对照组外,其余各组大鼠脑组织给予4Gy ¹²C⁶⁺离子束单次照射,辐射后第7日处死各组大鼠。HE染色法观察大鼠肾脏的病理形态变化,ELISA法检测大鼠血清IL-6的含量,实时荧光定量PCR法测定大鼠肾脏Bcl-2、Bax和Caspase-3的基因表达,免疫组化法检测大鼠肾脏Bcl-2、Bax、Caspase-3和NF-κB的蛋白表达。结果: 与正常对照组比较,单纯辐射模型组体重和肾脏指数均显著降低,血清IL-6的含量显著升高,肾脏Bcl-2的基因表达和蛋白表达均显著降低,Bax和Caspase-3的基因表达和蛋白表达均显著升高,NF-κB的蛋白表达也显著升高(P＜ 0.01),单纯辐射组肾小球系膜细胞明显增生,肾小管间质血管明显扩张充血,肾小管管腔狭窄、不规则。与单纯辐射模型组相比,黄芪汤高剂量组体重和肾脏指数均明显升高,黄芪汤各干预组肾脏Bcl-2的基因表达和蛋白表达均显著升高(P＜0.05或P＜0.01);而黄芪汤中、高剂量组Bax和Caspase-3的蛋白表达均显著降低,各干预组血清IL-6的含量显著降低,肾脏Bax和Caspase-3的基因表达均显著降低,肾脏NF-κB的蛋白表达显著下降(P＜0.05或P＜0.01),黄芪汤高剂量组可见肾小球系膜细胞增生情况明显改善,肾小管轮廓清晰。结论: 黄芪汤对¹²C⁶⁺离子辐射脑模型鼠的肾损伤具有一定的防护作用,其作用机制可能与调控Bcl-2/NF-κB信号通路有关。     

Putative tumor suppressor cytoglobin promotes aryl hydrocarbon receptor ligand–mediated triple negative breast cancer cell death

Nearly 40 000 women die annually from breast cancer in the United States. Clinically available targeted breast cancer therapy is largely ineffective in triple negative breast cancer (TNBC), characterized by tumors that lack expression of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (Her2). TNBC is associated with a poor prognosis. Previous reports show that aryl hydrocarbon receptor (AhR) partial agonist 2-(4-amino-3-methylphenyl)-5-fluorobenzothiazole (5F 203) selectively inhibits the growth of breast cancer cells, including those of the TNBC subtype. We previously demonstrated that 5F 203 induced the expression of putative tumor suppressor gene cytoglobin (CYGB) in breast cancer cells. In the current study, we determined that 5F 203 induces apoptosis and caspase-3 activation in MDA-MB-468 TNBC cells and in T47D ER⁺ PR ⁺ Her2 ⁻ breast cancer cells. We also show that caspases and CYGB promote 5F 203–mediated apoptosis in MDA-MB-468 cells. 5F 203 induced lysosomal membrane permeabilization (LMP) and cathepsin B release in MDA-MB-468 and T47D cells. In addition, silencing CYGB attenuated the ability of 5F 203 to induce caspase-3/-7 activation, proapoptotic gene expression, LMP, and cathepsin B release in MDA-MB-468 cells. Moreover, 5F 203 induced CYGB protein expression, proapoptotic protein expression, and caspase-3 cleavage in MDA-MB-468 cells and in MDA-MB-468 xenograft tumors grown orthotopically in athymic mice. These data provide a basis for the development of AhR ligands with the potential to restore CYGB expression as a novel strategy to treat TNBC.     

Differential effects on growth, cell cycle arrest, and induction of apoptosis by resveratrol in human prostate cancer cell lines.

Epidemiologic studies have suggested that nutrition plays an important role in carcinogenesis and that 30% of cancer morbidity and mortality can potentially be prevented with proper adjustment of diets. Resveratrol, a polyphenol present in red wines and a variety of human foods, has recently been reported to exhibit chemopreventive properties when tested in a mouse skin cancer model system. In this study, we investigated the effects of resveratrol on growth, induction of apoptosis, and modulation of prostate-specific gene expression using cultured prostate cancer cells that mimic the initial (hormone-sensitive) and advanced (hormone-refractory) stages of prostate carcinoma. Androgen-responsive LNCaP and androgen-nonresponsive DU-145, PC-3, and JCA-1 human prostate cancer cells were cultured with different concentrations of resveratrol (2. 5 x 10(-5)-10(-7) M). Cell growth, cell cycle distribution, and apoptosis were determined. Addition of 2.5 x 10(-5) M resveratrol led to a substantial decrease in growth of LNCaP and in PC-3 and DU-145 cells, but only had a modest inhibitory effect on proliferation of JCA-1 cells. Flow cytometric analysis showed resveratrol to partially disrupt G1/S transition in all three androgen-nonresponsive cell lines, but had no effect in the androgen-responsive LNCaP cells. In difference to the androgen-nonresponsive prostate cancer cells however, resveratrol causes a significant percentage of LNCaP cells to undergo apoptosis and significantly lowers both intracellular and secreted prostate-specific antigen (PSA) levels without affecting the expression of the androgen receptor (AR). These results suggest that resveratrol negatively modulates prostate cancer cell growth, by affecting mitogenesis as well as inducing apoptosis, in a prostate cell-type-specific manner. Resveratrol also regulates PSA gene expression by an AR-independent mechanism.     

Effects of Iejimalide B, a marine macrolide, on growth and apoptosis in prostate cancer cell lines

Iejimalide B, a marine macrolide, causes growth inhibition in a variety of cancer cell lines at nanomolar concentrations. We have investigated the effects of Iejimalide B on cell cycle kinetics and apoptosis in the p53+/AR+ LNCaP and p53-/AR- PC-3 prostate cancer cell lines. Iejimalide B, has a dose and time dependent effect on cell number (as measured by crystal violet assay) in both cell lines. In LNCaP cells Iejimalide B induces a dose dependent G0/G1 arrest and apoptosis at 48 h (as measured by Apo-BrdU staining). In contrast, Iejimalide B initially induces G0/G1 arrest followed by S phase arrest but does not induce apoptosis in PC-3 cells. qPCR and Western analysis suggests that Iejimalide B modulates the steady state level of many gene products associated with cell cycle (including cyclins D, E, and B and p21(waf1/cip1)) and cell death (including survivin, p21B and BNIP3L) in LNCaP cells. In PC-3 cells Iejimalide B induces the expression of p21(waf1/cip1), down regulates the expression of cyclin A, and does not modulate the expression of the genes associated with cell death. Comparison of the effects of Iejimalide B on the two cell lines suggests that Iejimalide B induces cell cycle arrest by two different mechanisms and that the induction of apoptosis in LNCaP cells is p53-dependent.     

Overexpression of regucalcin suppresses apoptotic cell death in cloned normal rat kidney proximal tubular epithelial NRK52E cells: change in apoptosis-related gene expression

The effect of regucalcin, a regulatory protein in intracellular signaling pathway, on cell death and apoptosis was investigated using the cloned normal rat kidney proximal tubular epithelial NRK52E cells overexpressing regucalcin. NRK52E cells (wild type) and stable regucalcin (RC)/pCXN2 transfectants were cultured for 72 h in a medium containing 5% bovine serum (BS) to obtain subconfluent monolayers. After culture for 72 h, cells were further cultured for 24-72 h in a medium without BS containing either vehicle, tumor necrosis factor-alpha (TNF-alpha; 0.1 or 1.0 ng/ml of medium), lipopolysaccharide (LPS; 0.1 or 1.0 microg/ml), Bay K 8644 (10(-9)-10(-7) M), or thapsigargin (10(-9)-10(-7) M). The number of wild-type cells was significantly decreased by culture for 42-72 h in the presence of TNF-alpha (0.1 or 1.0 ng/ml), LPS (0.1 or 1.0 microg/ml), Bay K 8644 (10(-7)-10(-5) M), or thapsigargin (10(-8) or 10(-7) M). The effect of TNF-alpha (0.1 or 1.0 ng/ml), LPS (0.1 or 1.0 microg/ml), Bay K 8644 (10(-7)-10(-6) M), or thapsigargin (10(-7) M) in decreasing the number of wild-type cells cultured for 24-72 h was significantly prevented in transfectants overexpressing regucalcin. Agarose gel electrophoresis showed the presence of low-molecular-weight deoxyribonucleic acid (DNA) fragments of adherent wild-type cells cultured with LPS (1.0 microg/ml), Bay K 8644 (10(-7) M), or thapsigargin (10(-8) M) for 24 h, and this DNA fragmentation was significantly suppressed in transfectants. DNA fragmentation in adherent cells was not seen by culture with TNF-alpha (1.0 ng/ml). TNF-alpha-induced decrease in the number of wild-type cells was significantly prevented by culture with caspase-3 inhibitor (10(-8) M), while LPS- or Bay K 8644-induced decrease in cell number was significantly prevented by caspase-3 inhibitor or N omega-nitro-L-arginine methylester (NAME) (10(-5) M), an inhibitor of nitric oxide (NO) synthase. Thapsigargin-induced decrease in cell number was not prevented in the presence of two inhibitors. Bcl-2 and Akt-1 mRNA levels were significantly increased in transfectants cultured for 24 h as compared with those of wild-type cells, while Apaf-1, caspase-3, or glyceroaldehyde-3-phosphate dehydrogenase (G3PDH) mRNA expressions were not significantly changed in transfectants. Culture with TNF-alpha (1.0 ng/ml), LPS (1.0 microg/ml), Bay K 8644 (l0(-7) M), or thapsigargin (10(-8) M) caused a significant increase in caspase-3 mRNA levels in wild-type cells. LPS (1.0 microg/ml) significantly decreased Bcl-2 mRNA expression in the cells. Their effects on the gene expression of apoptosis-related proteins were not significantly changed in transfectants. This study demonstrates that overexpression of regucalcin has a suppressive effect on cell death and apoptosis induced by various factors which their action are mediated through many intracellular signaling pathways, and that it modulates the gene expression of apoptosis-related proteins.     

Role of miR-486-5p in regulating renal cell carcinoma cell proliferation and apoptosis via TGF-β–activated kinase 1

Renal cell carcinoma (RCC) is a common kidney tumor in adults. The role of miR-486-5p in RCC is unknown. The aim of our study was to identify new targets regulated by miR-486-5p in RCC, to obtain a deeper insight into the network and to better understand the role of these microRNAs and their targets in carcinogenesis of RCC. We performed a series of tests and found consistently lower expression levels of miR-486-5p in kidney cancer cells. Restoration of miR-486-5p expression in RCC cells could lead to the suppression of cell proliferation and the increase of cell apoptosis. Further studies demonstrated that TGF-β–activated kinase 1 was a target gene of miR-486-5p in kidney cancer cells. It was also shown that C-C motif chemokine ligand 2 (CCL2) from tumor-associated macrophages downregulated miR-486-5p expression, and miR-486-5p inhibited RCC cell proliferation and apoptosis resistance induced by CCL2. The study demonstrates that there are potential diagnosis and therapy values of miR-486-5p in RCC.     

蟾毒灵可抑制人红白血病细胞增殖并下调肾母细胞瘤1基因表达

已有研究证实蟾毒灵具有抑制肿瘤细胞增殖及诱导细胞凋亡的作用,在白血病治疗中疗效显著,然而其机制尚未阐明。本研究试图探讨蟾毒灵对人红系白血病(HEL)细胞增殖,肾母细胞瘤基因1 (Wilms'tumor 1 gene, WT1)甲基化的影响及其可能的作用机制。本研究采用不同浓度的蟾毒灵处理HEL细胞,观察细胞形态、增殖情况和细胞周期,采用RT-PCR、Western blotting和免疫细胞化学法检测WT1的mRNA和蛋白表达水平,并用甲基化特异性分析WT1的DNA甲基化和DNA甲基转移酶3a (DNMT3a)的蛋白表达水平。研究结果表明,蟾毒灵对HEL细胞的增殖抑制作用呈剂量依赖性,抑制率为23.13%～84.62%。在蟾毒灵处理的HEL细胞中观察到典型的凋亡形态特征;细胞周期增殖指数由75.45降至49.67;WT1 mRNA及其蛋白表达水平随着蟾毒灵剂量的增加而逐渐降低,同时WT1基因的甲基化状态由未甲基化状态变为部分或完全甲基化状态。而蟾毒灵处理后DNMT3a蛋白的表达水平逐渐增加,呈剂量依赖性。我们的研究初步说明蟾毒灵不仅能显著抑制HEL细胞增殖,阻滞G0/G1期细胞周期,还能诱导细胞凋亡,下调WT1的表达水平。