RESUMO
Impaired healing is common in wounds infected with the major human pathogen Staphylococcus aureus, although the underlying mechanisms are poorly understood. Here, we show that S. aureus lipoteichoic acid (LTA) inhibits platelet aggregation caused by physiological agonists and S. aureus and reduced platelet thrombus formation in vitro. The presence of D-alanine on LTA is necessary for the full inhibitory effect. Inhibition of aggregation was blocked using a monoclonal anti-platelet activating factor receptor (PafR) antibody and Ginkgolide B, a well-defined PafR antagonist, demonstrating that the LTA inhibitory signal occurs via PafR. Using a cyclic AMP (cAMP) assay and a Western blot for phosphorylated VASP, we determined that cAMP levels increase upon platelet incubation with LTA, an effect which inhibits platelet activation. This was blocked when platelets were preincubated with Ginkgolide B. Furthermore, LTA reduced hemostasis in a mouse tail-bleed assay.
Assuntos
Lipopolissacarídeos/farmacologia , Ativação Plaquetária/efeitos dos fármacos , Glicoproteínas da Membrana de Plaquetas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Staphylococcus aureus/química , Ácidos Teicoicos/farmacologia , Trombose/metabolismo , Animais , Anticorpos Monoclonais/farmacologia , Tempo de Sangramento , Plaquetas/efeitos dos fármacos , Cálcio/metabolismo , AMP Cíclico/metabolismo , Ginkgolídeos/farmacologia , Humanos , Lactonas/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Staphylococcus aureus/fisiologia , Trombose/sangue , Trombose/prevenção & controleRESUMO
PIM kinases have been shown to play a role in prostate cancer development and progression, as well as in some of the hallmarks of cancer, especially proliferation and apoptosis. Their upregulation in prostate cancer has been correlated with decreased patient overall survival and therapy resistance. Initial efforts to inhibit PIM with monotherapies have been hampered by compensatory upregulation of other pathways and drug toxicity, and as such, it has been suggested that co-targeting PIM with other treatment approaches may permit lower doses and be a more viable option in the clinic. Here, we present the rationale and basis for co-targeting PIM with inhibitors of PI3K/mTOR/AKT, JAK/STAT, MYC, stemness, and RNA Polymerase I transcription, along with other therapies, including androgen deprivation, radiotherapy, chemotherapy, and immunotherapy. Such combined approaches could potentially be used as neoadjuvant therapies, limiting the development of resistance to treatments or sensitizing cells to other therapeutics. To determine which drugs should be combined with PIM inhibitors for each patient, it will be key to develop companion diagnostics that predict response to each co-targeted option, hopefully providing a personalized medicine pathway for subsets of prostate cancer patients in the future.
Assuntos
Terapia de Alvo Molecular , Neoplasias da Próstata/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas c-pim-1/genética , Apoptose/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Humanos , Masculino , Fosfatidilinositol 3-Quinases/genética , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-pim-1/antagonistas & inibidores , Serina-Treonina Quinases TOR/genéticaRESUMO
PIM and PI3K/mTOR pathways are often dysregulated in prostate cancer, and may lead to decreased survival, increased metastasis and invasion. The pathways are heavily interconnected and act on a variety of common effectors that can lead to the development of resistance to drug inhibitors. Most current treatments exhibit issues with toxicity and resistance. We investigated the novel multikinase PIM/PI3K/mTOR inhibitor, AUM302, versus a combination of the PIM inhibitor, AZD-1208, and the PI3K/mTOR inhibitor BEZ235 (Dactolisib) to determine their impact on mRNA and phosphoprotein expression, as well as their functional efficacy. We have determined that around 20% of prostate cancer patients overexpress the direct targets of these drugs, and this cohort are more likely to have a high Gleason grade tumour (≥ Gleason 8). A co-targeted inhibition approach offered broader inhibition of genes and phosphoproteins in the PI3K/mTOR pathway, when compared to single kinase inhibition. The preclinical inhibitor AUM302, used at a lower dose, elicited a comparable or superior functional outcome compared with combined AZD-1208 + BEZ235, which have been investigated in clinical trials, and could help to reduce treatment toxicity in future trials. We believe that a co-targeting approach is a viable therapeutic strategy that should be developed further in pre-clinical studies.
Assuntos
Antineoplásicos/farmacologia , Compostos de Bifenilo/farmacologia , Imidazóis/farmacologia , Inibidores de Fosfoinositídeo-3 Quinase/farmacologia , Neoplasias da Próstata/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-pim-1/antagonistas & inibidores , Piridinas/farmacologia , Pirimidinas/farmacologia , Quinolinas/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Tiazolidinas/farmacologia , Tiofenos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Estudos de Coortes , Quimioterapia Combinada , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Proteínas Proto-Oncogênicas c-pim-1/genética , Proteínas Proto-Oncogênicas c-pim-1/metabolismo , RNA Mensageiro/genética , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismoRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.