Lipoprotein(a) (Lp[a]), is a significant risk factor for cardiovascular disease, yet is infrequently measured. A qualitative investigation was designed to better understand the barriers and facilitato Show more
Lipoprotein(a) (Lp[a]), is a significant risk factor for cardiovascular disease, yet is infrequently measured. A qualitative investigation was designed to better understand the barriers and facilitators to Lp(a) testing. Focus groups were held with clinicians (n = 26) and at-risk individuals (n = 24). Transcripts were thematically analyzed, guided by the Integrated Screening Action Model (I-SAM). Consistent with the I-SAM, barriers and facilitators of Lp(a) measurement were categorized as motivational, capability, and opportunity factors. Facilitators identified included perceived clinical utility, emotional reassurance associated with a newfound understanding of prior events, the ability to use Lp(a) knowledge to better prepare for the future, as well as active requests for testing. Barriers identified included a lack of perceived clinical utility and the potential to cause emotional distress with results, uncertainty and knowledge limitations around Lp(a), cost-related concerns, low expectations for testing, and clinician reluctance to test. This analysis highlights that Lp(a) testing decisions are multifactorial, providing multiple opportunities for intervention and improvement. Strategies to convey how Lp(a) measurement can inform risk assessment and treatment approaches may be foundational to encouraging more widespread testing. Show less
Natural killer (NK) cell phenotype and function are altered in patients with prostate cancer, and increased NK cell activity is associated with a better prognosis in patients with disease. For patient Show more
Natural killer (NK) cell phenotype and function are altered in patients with prostate cancer, and increased NK cell activity is associated with a better prognosis in patients with disease. For patients with advanced stage prostate cancer, immunotherapies are a promising approach when standard treatment options have been exhausted. With the rapid emergence of NK cell-based therapies, it is important to understand the mechanisms by which NK cells can be triggered to kill cancer cells that have developed immune-evasive strategies. Altering the cytokine profiles of advanced prostate cancer cells may be an area to explore when considering ways in which NK cell activation can be modulated. We have previously demonstrated that combining the cytokine, IL-27, with TLR3 agonist, poly(I:C), changes cytokine secretion in the advanced prostate cancer models, PC3 and DU145 cells. Herein, we extend our previous work to study the effect of primary human NK cells on prostate cancer cell death in an in vitro co-culture model. Stimulating PC3 and DU145 cells with IL-27 and poly(I:C) induced IFN-β secretion, which was required for activation of primary human NK cells to kill these stimulated prostate cancer cells. PC3 cells were more sensitized to NK cell-mediated killing when compared to DU145 cells, which was attributed to differential levels of IFN-β produced in response to stimulation with IL-27 and poly(I:C). IFN-β increased granzyme B secretion and membrane-bound TRAIL expression by co-cultured NK cells. We further demonstrated that these NK cells killed PC3 cells in a partially TRAIL-dependent manner. This work provides mechanistic insight into how the cytotoxic function of NK cells can be improved to target cancer cells. Show less
The canonical action of the p85α regulatory subunit of phosphatidylinositol 3-kinase (PI3K) is to associate with the p110α catalytic subunit to allow stimuli-dependent activation of the PI3K pathway. Show more
The canonical action of the p85α regulatory subunit of phosphatidylinositol 3-kinase (PI3K) is to associate with the p110α catalytic subunit to allow stimuli-dependent activation of the PI3K pathway. We elucidate a p110α-independent role of homodimerized p85α in the positive regulation of PTEN stability and activity. p110α-free p85α homodimerizes via two intermolecular interactions (SH3:proline-rich region and BH:BH) to selectively bind unphosphorylated activated PTEN. As a consequence, homodimeric but not monomeric p85α suppresses the PI3K pathway by protecting PTEN from E3 ligase WWP2-mediated proteasomal degradation. Further, the p85α homodimer enhances the lipid phosphatase activity and membrane association of PTEN. Strikingly, we identified cancer patient-derived oncogenic p85α mutations that target the homodimerization or PTEN interaction surface. Collectively, our data suggest the equilibrium of p85α monomer-dimers regulates the PI3K pathway and disrupting this equilibrium could lead to disease development. Show less