Polyphenon E Effects on Gene Expression in PC-3 Prostate Cancer Cells.

Polyphenon E (Poly E) is a standardized, caffeine-free green tea extract with defined polyphenol content. Poly E is reported to confer chemoprotective activity against prostate cancer (PCa) progression in the TRAMP model of human PCa, and has shown limited activity against human PCa in human trials. The molecular mechanisms of the observed Poly E chemopreventive activity against PCa are not fully understood. We hypothesized that Poly E treatment of PCa cells induces gene expression changes, which could underpin the molecular mechanisms of the limited Poly E chemoprevention activity against PCa. PC-3 cells were cultured in complete growth media supplemented with varied Poly E concentrations for 24 h, then RNA was isolated for comparative DNA microarray (0 vs. 200 mg/L Poly E) and subsequent TaqMan qRT-PCR analyses. Microarray data for 54,613 genes were filtered for >2-fold expression level changes, with 8319 genes increased and 6176 genes decreased. Eight genes involved in key signaling or regulatory pathways were selected for qRT-PCR. Two genes increased expression significantly, MXD1 (13.98-fold; p = 0.0003) and RGS4 (21.98-fold; p = 0.0011), by qRT-PCR. MXD1 and RGS4 significantly increased gene expression in Poly E-treated PC-3 cells, and the MXD1 gene expression increases were Poly E dose-dependent.

Development of a Certification Exam to Assess Undergraduate Students' Proficiency in Biochemistry and Molecular Biology Core Concepts.

With support from the American Society for Biochemistry and Molecular Biology (ASBMB), a community of biochemistry and molecular biology (BMB) scientist-educators has developed and administered an assessment instrument designed to evaluate student competence across four core concept and skill areas fundamental to BMB. The four areas encompass energy and metabolism; information storage and transfer; macromolecular structure, function, and assembly; and skills including analytical and quantitative reasoning. First offered in 2014, the exam has now been administered to nearly 4000 students in ASBMB-accredited programs at more than 70 colleges and universities. Here, we describe the development and continued maturation of the exam program, including the organic role of faculty volunteers as drivers and stewards of all facets: content and format selection, question development, and scoring.

Assessing stakeholder perceptions of the american society for biochemistry and molecular biology accreditation program for baccalaureate degrees.

The American Society for Biochemistry and Molecular Biology (ASBMB) began an accreditation program in 2013. The criteria for accreditation of undergraduate programs include sufficient infrastructure - number and expertise of faculty, physical space and equipment, support for faculty and students - and incorporation of core concepts in the curriculum - structure and function of biomolecules; information storage; energy transfer; and quantitative skills. Students in accredited programs are able to have their degrees ASBMB certified by taking an exam focused on knowledge or skills across the four core concept areas. Members of the accreditation committees administered a survey to key stakeholders in the BMB community: undergraduate programs, both those that have applied for accreditation and those that have not; alumni/ae of accredited programs; graduate and professional programs; and employers. The goals of the study were to gauge the success of the program and determine necessary areas of improvement. The results indicate that the major benefits of applying for accreditation are the impetus to gather data and analysis not generally collected, and access to assessment data via the exam. However, stakeholders outside of the undergraduate community showed little awareness of the accreditation program. Additionally, the application process itself was seen to be very time consuming. This feedback will be used to improve the process and engage in further outreach. © 2018 International Union of Biochemistry and Molecular Biology, 46(5):464-471, 2018.

Role of p73 Dinucleotide Polymorphism in Prostate Cancer and p73 Protein Isoform Balance.

Background. Molecular markers for prostate cancer (PCa) risks are currently lacking. Here we address the potential association of a dinucleotide polymorphism (DNP) in exon 2 of the p73 gene with PCa risk/progression and discern any disruption of p73 protein isoforms levels in cells harboring a p73 DNP allele. Methods. We investigated the association between p73 DNP genotype and PCa risk/aggressiveness and survival by fitting logistic regression models in 1,292 incident cases and 682 controls. Results. Although we detected no association between p73 DNP and PCa risk, a significant inverse relationship between p73 DNP and PCa aggressiveness (AT/AT + GC/AT versus GC/GC, OR = 0.55, 95%Cl = 0.31-0.99) was detected. Also, p73 DNP is marginally associated with overall death (dominant model, HR = 0.76, 95%Cl = 0.57-1.00, P = 0.053) as well as PCa specific death (HR = 0.69, 95%Cl = 0.45-1.06, P = 0.09). Western blot analyses for p73 protein isoforms indicate that cells heterozygous for the p73 DNP have lower levels of ∆Np73 relative to TAp73 (P < 0.001). Conclusions. Our findings are consistent with an association between p73 DNP and low risk for PCa aggressiveness by increasing the expressed TAp73/∆Np73 protein isoform ratio.

Identification of delta helicase as the bovine homolog of HUPF1: demonstration of an interaction with the third subunit of DNA polymerase delta.

Delta helicase is a 5' to 3' DNA helicase that partially co-purifies with DNA polymerase delta (pol delta) from fetal bovine thymus tissue. We describe the resolution of delta helicase from pol delta on heparin-agarose chromatography and its purification to apparent homogeneity by affinity purification on single-stranded DNA-cellulose chromatography, unique-sequence RNA-agarose chromatography, and ceramic hydroxyapatite chromatography. Delta helicase isolated from fetal bovine thymus had an apparent M(r) of 115 kDa in SDS-PAGE, and photo-crosslinked to [alpha-32P]ATP. Tandem mass spectrometry peptide mass data derived from the bovine polypeptide matched to human UPF1 (HUPF1), a 5' to 3' RNA and DNA helicase, and a requisite component of the mRNA surveillance complex. Antisera against HUPF1 cross-reacted with delta helicase on western analysis, and delta helicase activity was immunoinactivated by pre-incubation with antibodies to HUPF1, suggesting that delta helicase is the bovine homolog of HUPF1. Immunoprecipitation experiments demonstrated that HUPF1 interacts with the 66-kDa third subunit of pol delta in vivo.

Direct interaction of proliferating cell nuclear antigen with the small subunit of DNA polymerase delta.

The interaction between proliferating cell nuclear antigen (PCNA) and DNA polymerase delta is essential for processive DNA synthesis during DNA replication/repair; however, the identity of the subunit of DNA polymerase delta that directly interacts with PCNA has not been resolved until now. In the present study we have used reciprocal co-immunoprecipitation experiments to determine which of the two subunits of core DNA polymerase delta, the 125-kDa catalytic subunit or the 50-kDa small subunit, directly interacts with PCNA. We found that PCNA co-immunoprecipitated with human p50, as well as calf thymus DNA polymerase delta heterodimer, but not with p125 alone, suggesting that PCNA directly interacts with p50 but not with p125. A PCNA-binding motif, similar to the sliding clamp-binding motif of bacteriophage RB69 DNA polymerase, was identified in the N terminus of p50. A 22-amino acid oligopeptide containing this sequence (MRPFL) was shown to bind PCNA by far Western analysis and to compete with p50 for binding to PCNA in co-immunoprecipitation experiments. The binding of p50 to PCNA was inhibited by p21, suggesting that the two proteins compete for the same binding site on PCNA. These results establish that the interaction of PCNA with DNA polymerase delta is mediated through the small subunit of the enzyme.