Background
Although, especially in the United States, there has been a recent surge of legalized cannabis for either recreational or medicinal purposes, surprisingly little is known about clinical dose-response relationships, pharmaco- and toxicodynamic effects of cannabinoids such as Δ9-tetrahydrocannabinol (THC). Even less is known about other active cannabinoids.
Methods
To address this knowledge gap, an online extraction, high-performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) method for simultaneous quantification of 11 cannabinoids and metabolites including THC, 11-hydroxy-Δ9-tetrahydrocannabinol (11OH-THC), 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH), 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid glucuronide (THC-C-gluc), cannabinol (CBN), cannabidiol (CBD), cannabigerol (CBG), cannabidivarin (CBDV), Δ9-tetrahydrocannabivarin (THCV), and 11-nor-9-carboxy-Δ9-tetrahydrocannabivarin (THCV-COOH) was developed and validated in human urine and plasma.
Results
In contrast to atmospheric pressure chemical ionization (APCI), electrospray ionization (ESI) was associated with extensive ion suppression in plasma and urine samples. Thus, the APCI assay was validated showing a lower limit of quantification (LLOQ) ranging from 0.39 to 3.91 ng/mL depending on study compound and matrix. The upper limit of quantitation (ULOQ) was 400 ng/mL except for THC-C-gluc with a ULOQ of 2000 ng/mL. The linearity was r> 0.99 for all analyzed calibration curves. Acceptance criteria for intra- and inter-batch accuracy (85%-115%) and imprecision (<15%) were met for all compounds. In plasma, the only exceptions were THCV (75.3%-121.2% inter-batch accuracy) and CBDV (inter-batch imprecision, 15.7%-17.2%). In urine, THCV did not meet predefined acceptance criteria for intra-batch accuracy.
Conclusions
This assay allows not only for monitoring THC and its major metabolites, but also of major cannabinoids that are of interest for marijuana research and clinical practice.
Due to the disseminated nature of leukemia, malignant cells are exposed to many different tissue microenvironments, including a variety of extramedullary sites. In the present study, we demonstrate that leukemic cells residing in the liver display unique biological properties, and also contribute to systemic changes that influence physiological responses to chemotherapy. Specifically, the liver microenvironment induces metabolic adaptations via up-regulating expression of endothelial lipase (LIPG) in leukemia cells, which not only stimulates tumor cell proliferation through polyunsaturated fatty acid (PUFA) mediated pathways, but also promotes survival by stabilizing anti-apoptotic proteins. Additionally, hepatic infiltration and tissue damage caused by malignant cells induces release of liver-derived enzymes capable of degrading chemotherapy drugs, an event which further protects leukemia cells from conventional therapies. Together, these studies demonstrate a unique role for liver in modulating the pathogenesis of leukemic disease and suggest that the hepatic microenvironment may protect leukemia cells from chemotherapeutic challenge. SIGNIFICANCE The studies presented herein demonstrate that the liver provides a microenvironment in which leukemia cells acquire unique metabolic properties. The adaptations that occur in the liver confer increased resistance to chemotherapy. Therefore, we propose that therapies designed to overcome liver-specific metabolic changes will yield improved outcomes for leukemia patients. Research.
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