Anti-Proliferative Properties and Proapoptotic Function of New CB2 Selective Cannabinoid Receptor Agonist in Jurkat Leukemia Cells

Abstract

Several studies demonstrated that cannabinoids reduce tumor growth, inhibit angiogenesis, and decrease cancer cell migration. As these molecules are well tolerated, it would be interesting to investigate the potential benefit of newly synthesized compounds, binding cannabinoid receptors (CBRs). In this study, we describe the synthesis and biological effect of 2-oxo-1,8-naphthyridine-3-carboxamide derivative LV50, a new compound with high CB2 receptor (CB2R) affinity. We demonstrated that it decreases viability of Jurkat leukemia cells, evaluated by Trypan Blue and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), but mainly induces a proapoptotic effect. We observed an increase of a hypodiploid peak by propidium iodide staining and changes in nuclear morphology by Hoechst 33258. These data were confirmed by a significant increase of Annexin V staining, cleavage of the nuclear enzyme poly(ADP-ribose)-polymerase (PARP), and caspases activation. In addition, in order to exclude that LV50 non-specifically triggers death of all normal leukocytes, we tested the new compound on normal peripheral blood lymphocytes, excluding the idea of general cytotoxicity. To characterize the involvement of CB2R in the anti-proliferative and proapoptotic effect of LV50, cells were pretreated with a specific CB2R antagonist and the obtained data showed reverse results. Thus, we suggest a link between inhibition of cell survival and proapoptotic activity of the new compound that elicits this effect as selective CB2R agonist.

Virodhamine, an endocannabinoid, induces megakaryocyte differentiation by regulating MAPK activity and function of mitochondria

“…To detect CB2 receptor protein levels, we performed western blot study with appropriate positive and negative controls. The lysates of Jurkat leukemia cells (Capozzi et al, 2018) and K562 cells (Alberich Jordà et al, 2004) were used, respectively, as the positive and negative controls to test the specificity of CB2 receptor antibody ( n = 3; Figure 2d). Consistent with the messenger RNA (mRNA) levels, we found that the protein expression of CB2 receptor was significantly increased in virodhamine‐induced Dami cells when compared with uninduced control (Dami cells; n = 3; p < .02; Figure 2d).…”

A Guide to Targeting the Endocannabinoid System in Drug Design

“…Multiple CB1 and CB2 agonists were shown to elicit antitumor properties both in vitro and in vivo (for a review, see: [267]). For instance, CB2 agonist, LV50 elicited cytotoxic effect in lymphoblastoid cells with high specificity to neoplasm cells [268], and WIN 55,212-2, CB1/2 agonist was able to arrest cell cycle and cause apoptosis in renal carcinoma in vitro [269]. In addition, allosteric CB1 modulators inhibiting cell proliferation in vitro [270] are a promising approach.…”

Characterization of Subtype Selective Cannabinoid CB2 Receptor Agonists as Potential Anti-Inflammatory Agents

“…Consistent with prior studies showing the anti-inflammatory effects of CB 2 agonists [ 13 , 14 , 15 , 16 , 17 , 18 , 30 ], both compounds inhibited PHA/PMA-induced IL-2 and TNF-α production. Although K i and EC 50 values calculated from binding and GTPγS binding were different than the concentration used for treating cells, which is common when performing functional evaluation using immune cells [ 16 , 20 , 31 , 32 , 33 , 34 ]. This is not surprising considering Ki values were calculated from assays in a simple environment only including the cell membrane and compounds in glass tubes, compared with functional assays using live cells.…”