No abstract

The hyaluronidase Hyal1 is clinically and functionally implicated in prostate cancer progression and metastasis. Elevated Hyal1 accelerates vesicular trafficking in prostate tumor cells, thereby enhancing their metastatic potential in an autocrine manner through increased motility and proliferation. In this report, we found Hyal1 protein is a component of exosomes produced by prostate tumor cell lines overexpressing Hyal1. We investigated the role of exosomally shed Hyal1 in modulating tumor cell autonomous functions and in modifying the behavior of prostate stromal cells. Catalytic activity of Hyal1 was necessary for enrichment of Hyal1 in the exosome fraction, which was associated with increased presence of LC3BII, an autophagic marker, in the exosomes. Hyal1-positive exosome contents were internalized from the culture medium by WPMY-1 prostate stromal fibroblasts. Treatment of prostate stromal cells with tumor exosomes did not affect proliferation, but robustly stimulated their migration in a manner dependent on Hyal1 catalytic activity. Increased motility of exosome-treated stromal cells was accompanied by enhanced adhesion to a type IV collagen matrix, as well as increased FAK phosphorylation and integrin engagement through dynamic membrane residence of β1 integrins. The presence of Hyal1 in tumor-derived exosomes and its ability to impact the behavior of stromal cells suggests cell-cell communication via exosomes is a novel mechanism by which elevated Hyal1 promotes prostate cancer progression.

The polymerase chain reaction (PCR) has found wide application in biochemistry and molecular biology such as gene expression studies, mutation detection, forensic analysis and pathogen detection. Increasingly quantitative real time PCR is used to assess copy numbers from overall yield. In this study the yield is analyzed as a function of several processes: (1) thermal damage of the template and polymerase occurs during the denaturing step, (2) competition exists between primers and templates to either anneal or form dsDNA, (3) polymerase binding to annealed products (primer/ssDNA) to form ternary complexes and (4) extension of ternary complexes. Explicit expressions are provided for the efficiency of each process, therefore reaction conditions can be directly linked to the overall yield. Examples are provided where different processes play the yield-limiting role. The analysis will give researchers a unique understanding of the factors that control the reaction and will aid in the interpretation of experimental results.

Understanding the relationship between molecular structure and function represents an important goal of undergraduate life sciences. Although evidence suggests that handling physical models supports gains in student understanding of structure–function relationships, such models have not been widely implemented in biochemistry classrooms. Three‐dimensional (3D) printing represents an emerging cost‐effective means of producing molecular models to help students investigate structure–function concepts. We developed three interactive learning modules with dynamic 3D printed models to help biochemistry students visualize biomolecular structures and address particular misconceptions. These modules targeted specific learning objectives related to DNA and RNA structure, transcription factor‐DNA interactions, and DNA supercoiling dynamics. We also designed accompanying assessments to gauge student learning. Students responded favorably to the modules and showed normalized learning gains of 49% with respect to their ability to understand and relate molecular structures to biochemical functions. By incorporating accurate 3D printed structures, these modules represent a novel advance in instructional design for biomolecular visualization. We provide instructors with the materials necessary to incorporate each module in the classroom, including instructions for acquiring and distributing the models, activities, and assessments. © 2019 International Union of Biochemistry and Molecular Biology, 47(3):303–317, 2019.

3D printing represents an emerging technology with significant potential to advance life-science education by allowing students to directly explore the relationship between macromolecular structure and function. In this article and supplemental video guide, we describe our development of a model-based instructional module on DNA supercoiling and outline practical tips for implementing models in undergraduate classrooms. We also present a procedure to design and print 3D dynamic models for classroom use. Furthermore, we describe repositories of 3D biomolecule files to make using models accessible and cost-effective.