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Sison, A.

Publications and source records attributed to Sison, A..

2 recordsLinked to original sources

Transcriptional Landscape of Hepatocellular Carcinoma Reveals that Patient Ethnic-Origin Influences Patterns of Expression

The global incidence of hepatocellular carcinoma (HCC) has increased threefold in the last 30 years. In the United States, individuals with ancestry from Asia, Africa and Latin America have a significantly higher risk of developing HCC. However, the molecular mechanisms by which HCC disparities occur remain mostly understudied. Herein, we employed advanced bioinformatics analysis tools to identify genomic drivers that could explain the differences seen among HCC patients of distinct ethnicities (geographic origins). Data from TCGA and open-source software tools HiSTAT, StringTie, and Ballgown were used to map next-generation sequencing (NGS) reads from DNA and RNA, assemble transcripts, and quantify gene abundance. Differential genes/transcripts were mapped to known biomarkers and targets of systemic HCC therapeutics. Four overlapping transcripts were identified between each ethnicity group: FCN2, FCN3, COLEC10, and GDF2. However, we also found that multiple genes are expressed in an ethnicity-specific manner. Our models also revealed that both current and emerging biomarkers fail to capture heterogeneity between patients of different ethnicities. Finally, we have determined that first-line treatment, such as Sorafenib, may be better suited for Asian patients, while Lenvatinib may exhibit better efficacy for Caucasian patients. In conclusion, we have outlined that the pathways involved in early hepatocarcinogenesis may occur in an ethnicity-specific manner and that these distinct phenotypes should be taken into account for biomarker and therapeutic development.

cancer biology↗

Robust Estimation of Bacterial Cell Count from Optical Density

Optical density (OD) is a fast, cheap, and high-throughput measurement widely used to estimate the density of cells in liquid culture. These measurements, however, cannot be compared between instruments without a standardized calibration protocol and are challenging to relate to actual cell count. We address these shortcomings with an interlaboratory study comparing three OD calibration protocols, as applied to eight strains of E. coli engineered to constitutively express varying levels of GFP. These three protocols--comparison with colloidal silica (LUDOX), serial dilution of silica microspheres, and a reference colony-forming unit (CFU) assay--are all simple, low-cost, and highly accessible. Based on the results produced by the 244 teams completing this interlaboratory study, we recommend calibrating OD using serial dilution of silica microspheres, which readily produces highly precise calibration (95.5% of teams having residuals less than 1.2-fold), is easily assessed for quality control, and as a side effect also assesses the effective linear range of an instrument. Moreover, estimates of cell count from silica microspheres can be combined with fluorescence calibration against fluorescein to obtain units of Molecules of Equivalent Fluorescein (MEFL), allowing direct comparison and data fusion with equivalently calibrated flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.

synthetic biology↗