Surface Treatment and Adhesion Study

In photolithography, it is often the case that the resist has difficulty adhering to a wafer due to its hydrophobic nature. The purpose of this study was to determine the best method for avoiding such adhesion problems. This study describes that four different surface treatments, (1) No bake before resist coating, (2) Bake at 115ºC before priming, (3) SURPASS coating, and (4) HDMS priming, are examined for UV lithography of sub-ten micron-sized lines and pillar arrays, and that HDMS vapor priming is the most effective surface treatment in promoting adhesion

Characterization and quantification of necrotic tissues and morphology in multicellular ovarian cancer tumor spheroids using optical coherence tomography

The three-dimensional (3D) tumor spheroid model is a critical tool for high-throughput ovarian cancer research and anticancer drug development in vitro. However, the 3D structure prevents high-resolution imaging of the inner side of the spheroids. We aim to visualize and characterize 3D morphological and physiological information of the contact multicellular ovarian tumor spheroids growing over time. We intend to further evaluate the distinctive evolutions of the tumor spheroid and necrotic tissue volumes in different cell numbers and determine the most appropriate mathematical model for fitting the growth of tumor spheroids and necrotic tissues. A label-free and noninvasive swept-source optical coherence tomography (SS-OCT) imaging platform was applied to obtain two-dimensional (2D) and 3D morphologies of ovarian tumor spheroids over 18 days. Ovarian tumor spheroids of two different initial cell numbers (5,000- and 50,000- cells) were cultured and imaged (each day) over the time of growth in 18 days. Four mathematical models (Exponential-Linear, Gompertz, logistic, and Boltzmann) were employed to describe the growth kinetics of the tumor spheroids volume and necrotic tissues. Ovarian tumor spheroids have different growth curves with different initial cell numbers and their growths contain different stages with various growth rates over 18 days. The volumes of 50,000-cells spheroids and the corresponding necrotic tissues are larger than that of the 5,000-cells spheroids. The formation of necrotic tissue in 5,000-cells numbers is slower than that in the 50,000-cells ones. Moreover, the Boltzmann model exhibits the best fitting performance for the growth of tumor spheroids and necrotic tissues. Optical coherence tomography (OCT) can serve as a promising imaging modality to visualize and characterize morphological and physiological features of multicellular ovarian tumor spheroids. The Boltzmann model integrating with 3D OCT data of ovarian tumor spheroids provides great potential for high-throughput cancer research in vitro and aiding in drug development.Histology service provided by the Tissue Pathology Shared Resource was supported in part by the National Institute of General Medical Sciences Grant P20GM103639 and National Cancer Institute Grant P30CA225520 of the National Institutes of Health. Research reported in this publication was supported in part by a Stephenson Cancer Center Trainee Research Award funded by the National Cancer Institute Cancer Center Support Grant P30CA225520 awarded to the University of Oklahoma Stephenson Cancer Center. Open Access fees paid for in whole or in part by the University of Oklahoma Libraries.Ye

Assessing Epigenetic Features of GABA(A) Receptor Genes in IPSCs, IPSC-Derived Neuroepithelial Cells, and IPSC-Derived Neural Cell Cultures

Alcohol use disorders (AUDs) affect approximately 13.9% of the population in the United States. Many groups have found a correlation between AUDs and a synonymous SNP in exon 5 of the GABRA2 gene (rs279858 T to C; C allele associated with AUDs). However, the biological effects of this and other SNPs in this region are unknown. Our lab has been using iPSC technology for the past few years to study AUDs. The lab has shown, using qPCR of mRNA, that a cluster of GABAA receptor subunit genes on chromosome 4p12 is expressed at minimal levels in neural cells derived from half of the iPSC lines studied and expression had a high correlation to genotype. However, subunits for GABAA receptor subunit genes located on other chromosomes showed robust expression in all lines. Results generated in this thesis project from chromatin immunoprecipitation and DNA CpG methylation experiments suggest that genetic factors linked to the rs279858 tag-SNP may moderate the developmental expression of the chromosome 4p12 GABAA receptor subunit gene cluster by altering epigenetic marks in the promoters of these genes

mRNA 5' terminal sequences drive 200-fold differences in expression through effects on synthesis, translation and decay.

mRNA regulatory sequences control gene expression at multiple levels including translation initiation and mRNA decay. The 5' terminal sequences of mRNAs have unique regulatory potential because of their proximity to key post-transcriptional regulators. Here we have systematically probed the function of 5' terminal sequences in gene expression in human cells. Using a library of reporter mRNAs initiating with all possible 7-mer sequences at their 5' ends, we find an unexpected impact on transcription that underlies 200-fold differences in mRNA expression. Library sequences that promote high levels of transcription mirrored those found in native mRNAs and define two basic classes with similarities to classic Initiator (Inr) and TCT core promoter motifs. By comparing transcription, translation and decay rates, we identify sequences that are optimized for both efficient transcription and growth-regulated translation and stability, including variants of terminal oligopyrimidine (TOP) motifs. We further show that 5' sequences of endogenous mRNAs are enriched for multi-functional TCT/TOP hybrid sequences. Together, our results reveal how 5' sequences define two general classes of mRNAs with distinct growth-responsive profiles of expression across synthesis, translation and decay