Functional single nucleotide polymorphism in C20orf54 modifies susceptibility to esophageal squamous cell carcinoma

The aim of this study was to explore the association of C20orf54 functional single nucleotide polymorphism (SNP) with the susceptibility to esophageal squamous cell carcinoma (ESCC) in a northern China population. The C20orf54 SNP was genotyped by direct sequencing in 240 cancer patients and 198 controls in northern China. The results showed that drinking status, family history of ESCC, and body mass index have great influence on the risk of developing ESCC. The overall genotype frequencies of C20orf54 in ESCC patients have a significant difference with healthy controls (χ(2)  = 8.06, P = 0.018). By using C/C genotype as the reference, the C/T genotype showed a significantly decreased risk to the development of ESCC. Thus, compared with the C/C genotype, smokers, drinkers with C/T genotype significantly decreased the risk of developing ESCC. A positive family history of ESCC with C/T and T/T genotype both increased the risk of developing ESCC. Body mass index between 18.5 and 24 with C/T genotype significantly decreased the risk of developing ESCC. The present study suggests that the C20orf54 functional SNP might be associated with a risk of development in ESCC.

55 STUDY ON THE INTERSPECIFIC NUCLEAR TRANSFER OF PRZEWALSKI'S GAZELLES AND BOVINES

Przewalski’s gazelle (Procapra przewalskii), also known as Platts antelope, is an endangered species only found in China. It belongs to the Artiodactyla order, Bovidae family, antelope subfamily, and Gazella genus. In this study, 5 experiments were designed to examine the developmental potential of Przewalski’s gazelle somatic cells transplanted into bovine enucleated oocytes. Enucleation was conducted by Hoechst 33342 staining of the oocytes and guided by a fluorescent microscope to ensure the removal of the nuclei. The gazelle cells were then transferred to the enucleated oocytes and electrically fused to reconstructed embryos. The study resulted in 5 major findings. (1) When gazelle-bovine reconstructed embryos were treated with the deacetylase inhibitor valproic acid (VPA), at different concentrations and for different times, treatment of the cloned embryos with VPA at 0.5 mM for 24 h significantly increased the 8- to 16-cell-stage embryo development [61.9% (96/155) v. 33.8% (46/136) control]. However, the morula [1.3% (2/155) v. 1.5% (2/155); P > 0.05] and blastocyst (0.7% v. 1.5%; P > 0.05) development were similar to that of the control. In the intraspecific (bovine-bovine) control group, the cleavage, morula and blastocyst development of 3 cloned embryos were 72.6% (127/175), 28.0% (49/175), and 23.4% (41/175). (2) Octamer-binding transcription factor 4 (Oct-4), as a developmental potential and expression marker, was transfected to gazelle cells. When Oct-4-eGFP-confected cells were transferred, the cloned embryo development did not improve either with or without VPA treatment. (3) When the gazelle-bovine embryos were treated with the deacetylase inhibitor trichostatin A (TSA) for 24 h at 10 ng mL–1, blastocyst development was significantly higher than in the control group [3.6% (6/168) v. 0.8% (1/125); P < 0.05]. (4) When a reverse NT protocol, in which the oocyte nucleus was removed after the cell nucleus was fused to the oocyte, was used for NT, the cloned embryo development did not improve. (5) The gazelle-bovine and bovine-bovine cloned embryos at 8- to 16-cell stages, gazelle cells, bovine cells, and bovine oocytes transcriptomes were analyzed by Affymetrix microarray (Affymetrix Microarray Inc., Santa Clara, CA, USA) and repeated twice. A total of 643 genes were activated in gazelle-cattle embryos compared with oocytes, whereas 1527 genes were activated in bovine-bovine clones. A total of 1010 genes that were exclusively expressed in gazelle somatic cells were still expressed in the interspecies cloned embryos. In conclusion, TSA treatment of Przewalski’s gazelle somatic cells transferred into enucleated bovine oocytes improved development of cloned embryos to the blastocyst stage, although still with low efficiency. Data from microarray analyses of the gazelle-cattle embryos showed that over 1000 gazelle-specific genes were still expressed in the interspecific cloned embryos. This work was supported by the National Basic Research Program of China (no. 2012CB22306).

45 EFFECT OF DEACETYLASE INHIBITOR VALPROIC ACID ON BOVINE CULTURED SOMATIC CELLS

Normal development depends on a precise sequence of changes in the configuration of chromatin. Epigenetic modifications, such as histone acetylation and methylation and DNA methylation, control the precise tissue-specific gene expressions. Valproic acid (VPA) is an aliphatic acid compound and a deacetylase inhibitor that influences cellular proliferation, differentiation, apoptosis, and migration. Several studies have shown that treatment of fused, cloned embryos with VPA improved embryo development. However, whether the treatment of donor cells with VPA affected cloned embryo development was not clear. In the present study, bovine fibroblast cells were treated with VPA at 0, 0.25, 0.5, 1.0, 2.0, and 4.0 mM concentrations for 24 and 48 h, respectively. The cell growth, cell cycle, diploid composition, and histone modifications were examined. The results showed that (1) when the cells were treated with VPA at and over 2.0 mM concentrations for 24 or 48 h, cell growth was significantly inhibited; (2) VPA treatment resulted in a decrease in cell diploid composition; (3) VPA induced the arrestment of cells at the G0/G1 stages; (4) VPA treatment increased early cell apoptosis; (5) VPA at a 4.0 mM concentration and treatment of cells for 24 h improved H3K9 acetylation; however, treatment of cells with VPA decreased H3K9 methylation in all experimental groups; and (6) when the cells treated with VPA at 0, 0.25, 0.5, 1.0, and 2.0 mM concentrations for 24 h were used as donor cells for NT, the cleavage rates were 83.2, 80.0, 82.1, 80.5, and 65.5%, respectively, and the percentages of blastocyst development were 30.5, 29.6, 29.2, 25.0, and 15.5%, respectively. When the cells were treated with VPA at 4.0 mM concentration, the cleavage (65.5%, 76/116) and blastocyst development (15.5%, 18/116) significantly decreased as compared with the control [83.2% (158/190) and 30.5% (58/190), respectively]. The cell numbers of the blastocysts derived from VPA treatment at 0, 0.25, 0.5, 1.0, and 2.0 mM concentrations were 89.6, 88.6, 87.6, 75.0, and 71.3, respectively, which decreased with the increase in VPA concentration. In conclusion, VPA affected cell growth and histone modifications in a concentration-dependent manner. The VPA-treated cells did not improve the cloned embryo development and even decreased blastocyst when VPA was at a high concentration. This work was supported by the National Basic Research Program of China (no. 2012CB22306).

Whole blood genome-wide gene expression profile in males after prolonged wakefulness and sleep recovery

Although the specific functions of sleep have not been completely elucidated, the literature has suggested that sleep is essential for proper homeostasis. Sleep loss is associated with changes in behavioral, neurochemical, cellular, and metabolic function as well as impaired immune response. Using high-resolution microarrays we evaluated the gene expression profiles of healthy male volunteers who underwent 60 h of prolonged wakefulness (PW) followed by 12 h of sleep recovery (SR). Peripheral whole blood was collected at 8 am in the morning before the initiation of PW (Baseline), after the second night of PW, and one night after SR. We identified over 500 genes that were differentially expressed. Notably, these genes were related to DNA damage and repair and stress response, as well as diverse immune system responses, such as natural killer pathways including killer cell lectin-like receptors family, as well as granzymes and T-cell receptors, which play important roles in host defense. These results support the idea that sleep loss can lead to alterations in molecular processes that result in perturbation of cellular immunity, induction of inflammatory responses, and homeostatic imbalance. Moreover, expression of multiple genes was downregulated following PW and upregulated after SR compared with PW, suggesting an attempt of the body to re-establish internal homeostasis. In silico validation of alterations in the expression of CETN3, DNAJC, and CEACAM genes confirmed previous findings related to the molecular effects of sleep deprivation. Thus, the present findings confirm that the effects of sleep loss are not restricted to the brain and can occur intensely in peripheral tissues.

RKIp inhibits the migration and invasion of human prostate cancer PC-3M cells through regulation of extracellular matrix

Raf kinase inhibitor protein (RKIP) plays a pivotal role in several intracellular signaling cascades and has been implicated as a metastasis suppressor in multiple cancer cells including prostate cancer cells, but the mechanism is not very clear. In this study, we investigated the effect of RKIP on cell proliferation, migration and invasion using human prostate cancer PC-3M cells as a model system. Our results indicate that RKIP does not effect cell proliferation in PC-3M cells, but inhibits both cell migration and cell invasion. In association with this inhibitory effect, RKIP down-regulates matrix metalloproteinases (MMP-2 and MMP-9), cathepsin B and urinary plasminogen activator (uPA). Also RKIP has the ability to regulate the expression of E-cadherin. But ectopic expression of RKIP does not affect the level of the Snail protein. As it has been indicated here, RKIP inhibits the migration and invasion ability of human prostate cancer cells through regulation of the extracellular matrix. These findings provide new mechanistic insight how RKIP suppresses metastasis in vitro.

Salivary gland gene expression atlas identifies a new regulator of branching morphogenesis

During organ development, local changes in gene expression govern morphogenesis and cell fate. We have generated a microanatomical atlas of epithelial gene expression of embryonic salivary glands. The mouse submandibular salivary gland first appears as a single mass of epithelial cells surrounded by mesenchyme, and it undergoes rapid branching morphogenesis to form a complex secretory organ with acini connected to an extensive ductal system. Using laser capture microdissection, we collected samples from 14 distinct epithelial locations at embryonic days 12.5, 13.5, 14, and 15, and characterized their gene expression by microarray analysis. These microarray results were evaluated by qPCR of biological replicates and by comparisons of the gene expression dataset with published expression data. Using this gene expression atlas to search for novel regulators of branching morphogenesis, we found a substantial reduction in mRNA levels of GSK3β at the base of forming clefts. This unexpected finding was confirmed by immunostaining, and inhibition of GSK3β activity enhanced salivary gland branching. This first microanatomical expression atlas of a developing gland characterizes changes in local gene expression during salivary gland development and differentiation, which should facilitate the identification of key genes involved in tissue morphogenesis.

Genetic diversity of the major histocompatibility complex class II in Alaskan caribou herds

We have sampled five different herds of caribou in Alaska to ascertain their major histocompatibility complex (MHC) class II diversity, and to assess whether the herds were significantly different in their MHC class II allele profiles. We complemented the MHC results with data from nine neutral microsatellite markers. The results indicate that while the microsatellites are diverse, there are no significant differences between the herds. However, for the MHC, we have shown that there is diversity at three of the four loci studied, the different herds have significantly different MHC class II allele profiles. It is also clear that although some of the herds have overlapping ranges, they are still different for their MHC class II alleles.