Immune Profiling and Quantitative Analysis Decipher the Clinical Role of Immune-Checkpoint Expression in the Tumor Immune Microenvironment of DLBCL.

PD-1/L1 and CTLA-4 blockade immunotherapies have been approved for 13 types of cancers and are being studied in diffuse large B-cell lymphoma (DLBCL), the most common aggressive B-cell lymphoma. However, whether both PD-1 and CTLA-4 checkpoints are active and clinically significant in DLBCL is unknown. Whether PD-1 ligands expressed by tumor cells or by the microenvironment of DLBCL are critical for the PD-1 immune checkpoint is unclear.

The tyrosine phosphatase PTPRO sensitizes colon cancer cells to anti-EGFR therapy through activation of SRC-mediated EGFR signaling.

Inappropriate activation of epidermal growth factor receptor (EGFR) plays a causal role in many cancers including colon cancer. The activation of EGFR by phosphorylation is balanced by receptor kinase and protein tyrosine phosphatase activities. However, the mechanisms of negative EGFR regulation by tyrosine phosphatases remain largely unexplored.

A novel proteomics-based clinical diagnostics technology identifies heterogeneity in activated signaling pathways in gastric cancers.

Purpose: The aim of this study was to utilize the proteomics-based Collaborative Enzyme Enhanced Reactive (CEER) immunoassay to investigate protein tyrosine phosphorylations as diagnostic markers in gastric cancers (GCs).

Experimental Design: Protein lysates from fresh-frozen 434 advanced stage GCs were analyzed for phosphorylation of HER1, HER2, p95HER2, HER3, cMET, IGF1R and PI3K. The pathway activation patterns were segregated based on the tumor HER2 status.

PI3K independent activation of mTORC1 as a target in lapatinib-resistant ERBB2+ breast cancer cells.

Therapies targeting the ERBB2 receptor, including the kinase inhibitor lapatinib (Tykerb, GlaxoSmithKline), have improved clinical outcome for women with ERBB2-amplified breast cancer. However, acquired resistance to lapatinib remains a significant clinical problem, and the mechanisms governing resistance remain poorly understood. We sought to define molecular alterations that confer an acquired lapatinib resistance phenotype in ER-/ERBB2+ human breast cancer cells.

Ubiquitin over-expression phenotypes and ubiquitin gene molecular misreading during aging in Drosophila melanogaster.

Molecular Misreading (MM) is the inaccurate conversion of genomic information into aberrant proteins. For example, when RNA polymerase II transcribes a GAGAG motif it synthesizes at low frequency RNA with a two-base deletion. If the deletion occurs in a coding region, translation will result in production of misframed proteins.

Hydrogen peroxide stimulates activity and alters behavior in Drosophila melanogaster.

Circadian rhythms in animals are regulated at the level of individual cells and by systemic signaling to coordinate the activities of multiple tissues. The circadian pacemakers have several physiological outputs, including daily locomotor rhythms. Several redox-active compounds have been found to function in regulation of circadian rhythms in cells, however, how particular compounds might be involved in regulating specific animal behaviors remains largely unknown.

CYP3A4 ubiquitination by gp78 (the tumor autocrine motility factor receptor, AMFR) and CHIP E3 ligases.

Human liver CYP3A4 is an endoplasmic reticulum (ER)-anchored hemoprotein responsible for the metabolism of >50% of clinically prescribed drugs. After heterologous expression in Saccharomyces cerevisiae, it is degraded via the ubiquitin (Ub)-dependent 26S proteasomal pathway that utilizes Ubc7p/Cue1p, but none of the canonical Ub-ligases (E3s) Hrd1p/Hrd3p, Doa10p, and Rsp5p involved in ER-associated degradation (ERAD). To identify an Ub-ligase capable of ubiquitinating CYP3A4, we examined various in vitro reconstituted mammalian E3 systems, using purified and functionally characterized recombinant components.

A role for protein phosphorylation in cytochrome P450 3A4 ubiquitin-dependent proteasomal degradation.

Cytochromes P450 (P450s) incur phosphorylation. Although the precise role of this post-translational modification is unclear, marking P450s for degradation is plausible. Indeed, we have found that after structural inactivation, CYP3A4, the major human liver P450, and its rat orthologs are phosphorylated during their ubiquitin-dependent proteasomal degradation.

Transcriptional profiling of MnSOD-mediated lifespan extension in Drosophila reveals a species-general network of aging and metabolic genes.

Background: Several interventions increase lifespan in model organisms, including reduced insulin/insulin-like growth factor-like signaling (IIS), FOXO transcription factor activation, dietary restriction, and superoxide dismutase (SOD) over-expression. One question is whether these manipulations function through different mechanisms, or whether they intersect on common processes affecting aging.

Results: A doxycycline-regulated system was used to over-express manganese-SOD (MnSOD) in adult Drosophila, yielding increases in mean and maximal lifespan of 20%.

Alteration of Drosophila life span using conditional, tissue-specific expression of transgenes triggered by doxycyline or RU486/Mifepristone.

The conditional systems Tet-on and Geneswitch were compared and optimized for the tissue-specific expression of transgenes and manipulation of life span in adult Drosophila. Two versions of Tet-on system reverse-tetracycline-Trans-Activator (rtTA) were compared: the original rtTA, and rtTAM2-alt containing mutations designed to optimize regulation and expression. The rtTAM2-alt version gave less leaky expression of target constructs in the absence of doxycyline, however the absolute level of expression that could be achieved was less than that produced by rtTA, in contrast to a previous report.