Basal Cell Carcinoma Gene Mutations Differ Between Asian, Hispanic, and Caucasian Patients: A Pilot Study.

BACKGROUND: Basal cell carcinoma (BCC) is the most common malignancy worldwide. While most BCCs are treated surgically, advanced BCCs are often treated with gene-targeted therapies. While there has been a lot of research in BCC from Caucasian patients, research is lacking in patients with skin of color. OBJECTIVE: To identify potential variations in BCC gene mutations between Asian, Hispanic, and Caucasian patients. METHODS: A cohort study was performed from 2015 to 2017 with 23 patients treated for BCC at an urban academic hospital. Gene mutations were assessed using a targeted mutation panel for 76 cancer-associated genes from formalin-fixed paraffin-embedded (FFPE) samples. RESULTS: Groups studied comprised Asian (n=5), Hispanic (n=10), and Caucasian (n=8) patients. The Hispanic cohort had the highest number of mutations per patient on average (3.4 versus 2.8 for both Caucasian and Asian cohorts). GATA3 mutations were more prevalent in Hispanic patients (P=0.02, single factor ANOVA). ARID1A and PTEN mutations co-occurred in the Hispanic cohort (P<0.05). The most common mutation in the Asian cohort was TP53 (2/5). The Caucasian cohort had the highest percent of UVB mutations (68.4%). CONCLUSIONS: This study shows potential differences in the prevalence of somatic gene mutations for BCC patients of different races and ethnicities, which could inform the underlying pathogenesis, impact the efficacy of therapies in specific populations, and may also help identify novel therapeutic targets. J Drugs Dermatol. 20(5): doi:10.36849/JDD.5884.

Next-generation sequencing identifies novel single nucleotide polymorphisms in high-risk cutaneous squamous cell carcinoma: A pilot study.

BACKGROUND: Cutaneous squamous cell carcinoma (SCC) causes 1 million cases in the United States annually. There are germline single nucleotide polymorphisms (SNPs) that result in an increased risk of SCC and altered response to therapy. PREMISE: There may be biologically relevant SNPs not detected using traditional GWAS studies. HYPOTHESIS: There are clinically and biologically relevant SNPs in high-risk SCC that may only be appreciated with next-generation sequencing. HOW TO TEST HYPOTHESIS: We performed next-generation sequencing (NGS) on primary SCCs using a targeted mutation panel with 76 cancer-associated genes. We analysed the presence of SNPs in a cohort of 20 high-risk SCCs compared to the American population (AP) (dbSNP). RELEVANCE AND PERSPECTIVES: Missense rs3822214 was present in significantly more SCC cases versus the AP. While the remainder is synonymous SNPs, there is growing evidence suggesting clinical relevance of these variants. A larger cohort to validate these findings would be useful.

Fabrication of versatile dynamic hyaluronic acid-based hydrogels.

In this study, an injectable and self-healing hydrogel based on the boronic ester dynamic covalent bond between phenylboronic acid modified hyaluronic acid (HA-PBA) and the commercially available poly (vinyl alcohol) (PVA) is prepared and should have multi-functions for biomedical applications. The hydrogels were rapidly formed under mild conditions, and the rheological properties and in vitro degradation were systematically characterized. The HA-based hydrogels possessed good injectability and self-healing properties because of the dynamic bond. Moreover, due to the sensitivity of boronic ester to the biologically relevant concentration of hydrogen peroxide (H2O2), a major reactive oxygen species (ROS), the injectable hydrogel could be used as a H2O2/ROS responsive drug delivery system. The hydrogels supported good viability of encapsulated neural progenitor cells (NPC) and protected NPC from ROS induced damage in vitro when H2O2 was present in the media. The dynamic hydrogels were further applied as bio-inks for 3D printing/bioprinting. Overall, this facilely prepared dynamic hydrogel based on HA-PBA and PVA may have many potential biomedical applications, including drug delivery, 3D culture of cells, and 3D bioprinting.

3-O sulfation of heparin leads to hepatotropism and longer circulatory half-life.

INTRODUCTION: Heparins are common blood anticoagulants that are critical for many surgical and biomedical procedures used in modern medicine. In contrast to natural heparin derived from porcine gut mucosa, synthetic heparins are homogenous by mass, polymer length, and chemistry. MATERIALS & METHODS: Stable cell lines expressing the human and mouse Stabilin receptors were used to evaluate endocytosis of natural and synthetic heparin. We chemoenzymatically produced synthetic heparin consisting of 12 sugars (dodecamers) containing 14 sulfate groups resulting in a non-3-O sulfated structure (n12mer). Half of the n12mer was modified with a 3-O sulfate on a single GlcNS sugar producing the 3-O sulfated heparin (12mer). Wildtype (WT), Stabilin-1 knock-out (KO), and Stabilin-2 KO C57BL/6 mice were developed and used for metabolic studies and provided as a source for primary liver sinusoidal endothelial cells. RESULTS & CONCLUSIONS: Human and mouse Stabilin-2 receptors had very similar endocytosis rates of both the 12mer and n12mer, suggesting that they are functionally similar in primary cells. Subcutaneous injections of the n12mer and 12mer revealed that the 12mer had a much longer half-life in circulation and a higher accumulation in liver. The n12mer never accumulated in circulation and was readily excreted by the kidneys before liver accumulation could occur. Liver sinusoidal endothelial cells from the Stabilin-2 KO mice had lower uptake rates for both dodecamers, whereas, the Stabilin-1 KO mice had lower endocytosis rates for the 12mer than the n12mer. 3-O sulfation of heparin is correlated to both a longer circulatory half-life and hepatotropism which is largely performed by the Stabilin receptors.

Purification of Hepatocytes and Sinusoidal Endothelial Cells from Mouse Liver Perfusion.

This protocol demonstrates a method for obtaining high yield and viability for mouse hepatocytes and sinusoidal endothelial cells (SECs) suitable for culturing or for obtaining cell lysates. In this protocol, the portal vein is used as the site for catheterization, rather than the vena cava, as this limits contamination of other possible cell types in the final liver preparation. No special instrumentation is required throughout the procedure. A water bath is used as a source of heat to maintain the temperature of all the buffers and solutions. A standard peristaltic pump is used to drive the fluid, and a refrigerated table-top centrifuge is required for the centrifugation procedures. The only limitation of this technique is the placement of the catheter within the portal vein, which is challenging on some of the mice in the 18 - 25 g size range. An advantage of this technique is that only one vein is utilized for the perfusion and the access to the vein is quick, which minimizes ischemia and reperfusion of the liver that reduces hepatic cell viability. Another advantage to this protocol is that it is easy to distinguish live from dead hepatocytes by eyesight due to the difference in cellular density during the centrifugation steps. Cells from this protocol may be used in cell culture for any downstream application as well as processed for any biochemical assessment.