STUDY THE ORDER OF MORPHOLOGY SELF-ASSEMBLED TRIBLOCK COPOLYMER THIN FILMS BY FFT OF THE AFM IMAGES

ABSTRACT A variety of block copolymer thin films with well-ordered nanostructures, which can be employed as templates for nanotechnologies including nanostructure membranes, nanoparticle synthesis, photonic crystal, and high-density information storage media, can be realized simply and at low cost by self-assembly. Long range ordering of morphology is paramount to realize applications of self-assembled block copolymer thin films in nanotechnologies. A better understanding of what parameters affect the ordering process can lead to the production of highly ordered arrays of nanostructures. In this paper, in order to effectively analyze the improvement in ordering, the Fast Fourier transform (FFT) analysis of the AFM images is used. Fast Fourier transform provide a mathematical analysis of the image that is similar to producing a diffraction pattern. From this "diffraction pattern" information on the order in the system can be obtained. Moreover, calculating an ordering parameter from the FFT provides a quantitative measure of the order present in the polymer template. The order parameter is calculated using equations which were tested against a manufactured perfect system and imperfect system to ensure that a perfect system would provide an order parameter of 1 and an imperfect system would create an order parameter of 0. The results show that the method is reasonable and effective to analyze the improvement in ordering that is achieved by using solvent annealing. Furthermore, the method can be used to understand the parameters in triblock copolymer thin film self-assembly process that create the most well ordered system

Loss of Nuclear Functions of HOXA10 Is Associated With Testicular Cancer Proliferation

Background: HOXA10 is a key transcriptional factor that regulates testis development as reported from previous transgenic mouse models and human inherited diseases. However, whether it also plays important roles in promoting the development of testicular cancer is not well-understood.Objective: To study the expression of HOXA10 and its regulated signaling pathways in testicular cancers.Design, Setting, and Participants: A tissue microarray was constructed with benign and cancerous testis. TCam2, NT-2, and NCCIT cell models were applied in this study.Intervention: Immunohistochemistry and immunofluorescence were performed to measure the expression and cellular localization of HOXA10 in testicular cancer tissues and cell models. Cell proliferation and cell cycling rates were determined by BrdU incorporation and flow cytometry assays. HOXA10 transcriptomes were profiled with Ampliseq RNA-seq in testicular cancer cells. Immunoblotting assays were used to detect HOXA10-regulated signaling.Results: HOXA10 is a nuclear protein in benign spermatocytes. Reduced nuclear expression and increased cytoplasmic expression of HOXA10 are associated with testicular cancers. These changes are consistent in both seminoma and non-seminoma. Enhanced HOXA10 expression in testicular cancer cell models inhibits cell proliferation and delays cell cycle progression through G2/M phases. These functions of HOXA10 mainly affect the TP53, cKit, STAT3, AKT, and ERK signaling pathways.Conclusions: Loss of nuclear functions of HOXA10 enhances proliferation of testicular cancer cells, suggesting that downregulation of HOXA10 transcription activity may promote the development of testicular cancers

Electrochemical mechanical micromachining based on confined etchant layer technique

National Science Foundation of China [91023006, 91023047, 91023043, 21061120456, 21021002]; Natural Science Foundation of Fujian Province of China [2012J06004]; Fundamental Research Funds for the Central Universities [2010121022]; Scientific Research Foundation for the Returned Overseas Chinese Scholars (State Education Ministry)The confined etchant layer technique (CELT) has been proved an effective electrochemical microfabrication method since its first publication at Faraday Discussions in 1992. Recently, we have developed CELT as an electrochemical mechanical micromachining (ECMM) method by replacing the cutting tool used in conventional mechanical machining with an electrode, which can perform lathing, planing and polishing. Through the coupling between the electrochemically induced chemical etching processes and mechanical motion, ECMM can also obtain a regular surface in one step. Taking advantage of CELT, machining tolerance and surface roughness can reach micro-or nano-meter scale

A Novel Statistic for Genome-Wide Interaction Analysis

Although great progress in genome-wide association studies (GWAS) has been made, the significant SNP associations identified by GWAS account for only a few percent of the genetic variance, leading many to question where and how we can find the missing heritability. There is increasing interest in genome-wide interaction analysis as a possible source of finding heritability unexplained by current GWAS. However, the existing statistics for testing interaction have low power for genome-wide interaction analysis. To meet challenges raised by genome-wide interactional analysis, we have developed a novel statistic for testing interaction between two loci (either linked or unlinked). The null distribution and the type I error rates of the new statistic for testing interaction are validated using simulations. Extensive power studies show that the developed statistic has much higher power to detect interaction than classical logistic regression. The results identified 44 and 211 pairs of SNPs showing significant evidence of interactions with FDR<0.001 and 0.001<FDR<0.003, respectively, which were seen in two independent studies of psoriasis. These included five interacting pairs of SNPs in genes LST1/NCR3, CXCR5/BCL9L, and GLS2, some of which were located in the target sites of miR-324-3p, miR-433, and miR-382, as well as 15 pairs of interacting SNPs that had nonsynonymous substitutions. Our results demonstrated that genome-wide interaction analysis is a valuable tool for finding remaining missing heritability unexplained by the current GWAS, and the developed novel statistic is able to search significant interaction between SNPs across the genome. Real data analysis showed that the results of genome-wide interaction analysis can be replicated in two independent studies

The Androgen Receptor Is a Key Component of Myometrium Phenotype Programming During Pregnancy

The economic burden associated with preterm birth is significant to our society. While research efforts on preterm birth over past decades had been directed toward understanding the late stage of parturition, recent discoveries have indicated that the timing of labour is delicately programmed as early as the initiation of pregnancy. We have proposed that there exists a myometrium phenotype programming during pregnancy consisting three characteristic stages referred to as the early proliferative, the midterm hypertrophic and the late contractile stages. This remarkable plasticity of myometrium allows it not only provides containment for fetus to be fully developed within the womb during pregnancy, but also performs coordinate contractions at the onset of labor to expel the fetus into extrauterine environment. Our two recent studies further demonstrate that the androgen receptor is a key component of myometrium phenotype programming. Here we summarize our endeavor in characterizing the androgen receptor signaling in myometrial smooth muscle cells

Driver or Passenger - Roles of the Glucocorticoid Receptor in Castration Resistance Prostate Cancers

Prostate cancer is the most commonly diagnosed cancer in men and the second leading cause of cancer death in men in North America. With the rate of new cases rising each year, prostate cancer poses a heavy burden on both the economy and society. While the first line of treatment for metastatic prostate cancer is androgen deprivation therapy, it has become evident that tumors eventually become castration resistant. One of the proposed mechanisms by which tumors overcome androgen deprivation therapy is through the expression and activation of glucocorticoid receptors. However, whether the glucocorticoid receptor functions as a key driver for castration resistant progression or a biomarker reflecting androgen receptor activity remains elusive. In our recent study, we utilized tissue microarrays and multiple prostate cancer xenograft and cell models to investigate the roles of the glucocorticoid receptor during castration resistant progression. As a result, we determined that the expression of the glucocorticoid receptor is inversely correlated with androgen receptor activity and is not associated with castration resistant phenotypes. In addition, we identified a negative androgen responsive element in the promoter region of the glucocorticoid receptor gene through chromatin immunoprecipitation analysis combined with DNA sequencing technology. We showed that the androgen receptor interacted directly to this response element to exert suppressive effects on the transcription of the glucocorticoid receptor gene. In conclusion, the expression of the glucocorticoid receptor is negatively regulated by the androgen receptor and can potentially serve as a biomarker to monitor prostate tumor progression

The Implication of Topoisomerase II Inhibitors in Synthetic Lethality for Cancer Therapy

DNA topoisomerase II (Top2) is essential for all eukaryotic cells in the regulation of DNA topology through the generation of temporary double-strand breaks. Cancer cells acquire enhanced Top2 functions to cope with the stress generated by transcription and DNA replication during rapid cell division since cancer driver genes such as Myc and EZH2 hijack Top2 in order to realize their oncogenic transcriptomes for cell growth and tumor progression. Inhibitors of Top2 are therefore designed to target Top2 to trap it on DNA, subsequently causing protein-linked DNA breaks, a halt to the cell cycle, and ultimately cell death. Despite the effectiveness of these inhibitors, cancer cells can develop resistance to them, thereby limiting their therapeutic utility. To maximize the therapeutic potential of Top2 inhibitors, combination therapies to co-target Top2 with DNA damage repair (DDR) machinery and oncogenic pathways have been proposed to induce synthetic lethality for more thorough tumor suppression. In this review, we will discuss the mode of action of Top2 inhibitors and their potential applications in cancer treatments

Complex Impacts of PI3K/AKT Inhibitors to Androgen Receptor Gene Expression in Prostate Cancer Cells

<div><p>Background</p><p>Androgen deprivation therapy (ADT) is the first-line treatment to metastatic prostate cancer (PCa). However, sustained expression and function of the androgen receptor (AR) gene contribute to the progression of castration resistant prostate cancers (CRPC). Additionally, tumors can adapt the PI3K/AKT survival pathway to escape ADT. Co-targeting AR and PI3K/AKT signaling has been proposed to be a more effective therapeutic means for CRPC patients. Many clinical trials are ongoing to test whether PI3K/AKT inhibitors are beneficial to PCa patients. However whether these inhibitors have any impacts on the expressions of full length AR (AR-FL) and its splice variant (AR-V7) remains unclear.</p><p>Methods</p><p>Four human prostate cancer cell lines (LNCaP, LNCaP95, VCaP and 22Rv1) with different genetic backgrounds were treated with five PI3K/AKT inhibitors (LY294002, Wortmannin, BKM120, AKTi and AZD5363) and or AKT siRNA. AR and AR-V7 protein and mRNA levels were measured by immunoblotting and real-time PCR assays. AR gene transcription initiation, alternative RNA splicing and AR mRNA degradation rates were also determined.</p><p>Results</p><p>PI3K/AKT inhibitors had various impacts on AR protein expressions primarily through alterations of AR gene transcription initiation and RNA splicing. However, these effects remained unchanged in the presence RNA silencing of the AKT genes.</p><p>Conclusion</p><p>PI3K/AKT inhibitors have off-target effects on AR gene expression in prostate cancer cells, which shall be considered when applying these inhibitors to PCa patients, particularly patients under ADT treatment.</p></div

Impacts of PI3K/AKT inhibitors to AR protein levels in LNCaP and LNCaP95 cells.

<p>(<b>A</b>) LNCaP and (<b>B</b>) LNCaP95 cells were treated with increasing doses of PI3K/AKT inhibitors LY294002 (0, 25, 50 uM), Wortmannin (0, 0.5 and 1 uM), BKM120 (0, 0.5 and 1 uM), AKTi (0, 5 and 10 uM) or AZD5363 (0, 2.5 and 5 uM) for 18 hours. Protein lysates were immunoblotted with AR (N-20), AR-V7, Pan-AKT, phosphor-AKT (ser473) and β-Actin antibodies. (<b>C</b>) Results were repeated at least three independent experiments. Densitometry analysis of protein bands were measured by the Image J software and plotted as mean+SEM. One-way ANOVA followed by student t-test was performed with * as P<0.05, ** as P<0.01 and *** as P<0.001.</p

Impacts of PI3K/AKT inhibitors to AR mRNA levels in PCa cells.

<p>LNCaP, LNCaP95, VCaP and 22Rv1 cells were treated with increasing doses of PI3K/AKT inhibitors LY294002 (0, 25, 50 uM), Wortmanin (0, 0.5 and 1 uM), BKM120 (0, 0.5 and 1 uM), AKTi (0, 5 and 10 uM) or AZD5363 (0, 2.5 and 5 uM) for 18 hours. AR-FL (<b>A</b>) and AR-V7 (<b>B</b>) mRNA expression levels relative to 18rS were determined by real-time PCR. Results were from three independent RNA extractions with triplicate real-time PCR assays on each RNA sample. Data was plotted as mean+SEM. One-way ANOVA followed by student t-test was performed with * as P<0.05, ** as P<0.01 and *** as P<0.001.</p