Treat Deadly Blood Cancer by Drug Repurposing.
Drug reassignment is a drug discovery technique that involves finding a new therapeutic context for an old drug to treat deadly blood cancer. Identification of compounds occurs by sifting through large libraries of active compounds, by querying the database of the response to gene expression of the cell line after treatment, or by combining several drugs. Despite the consensus on the potential and benefits of this drug discovery method, it is now the standard treatment for acute myeloid leukaemia ( AML) although preclinical did not reuse anticancer drugs. Verify to give several candidates. We believe there is a need for improvements in readout models and systems as, but take additional funding and confidence.
Anthelmintics increase the level of intracellular chloride in primary leukaemia cells, causing depolarization of the outer mitochondrial membrane and causing cell death. Supporting the idea that simultaneous attack of cell death mechanisms from different angles, it enhances the response to cell death. The combination of anthelmintic drugs with the BCL2 antagonist Navitoclax or the chemotherapeutic agent dexamethasone has shown synergistic activity in primary ALL. These data demonstrate the anti-leukemic activity of anthelmintic agents and support the use of drug reuse strategies to identify hitherto unrecognized anticancer agents capable of eliminating even intractable leukaemia.
Treated cells were incubated at 37 ° C with 5% CO and 95% humidity for 72 hours. Cell viability was assessed by CyQuant staining and analyzed using Labtech Acumen Cellista TTP. After 1 hour of reconstitution, ALL cells were treated with moxidectin or ivermectin for 2 or 4 hours, followed by incubation at 37 ° C for 1 hour with MQAE and 15 minutes with PI. collected, centrifuged and reused in fresh 1X phosphate-saline solution.
After reconstitution, ALL cells were treated with moxidectin or ABT263 for 2 hours and then incubated at 37 ° C for 15 minutes with TMRE. After staining, cells were harvested, centrifuged and re-treated in 1 × PBS. The fluorescence of TMRE was quantified using flow cytometry. Anthelmintics cause cell death in the absence of active caspase and RIPK1, with the ability to induce helminth cell death.
Ex vivo drug discovery strategy of patient-derived xenograft cells in co-culture with mesenchymal stromal cells treated with 2487 compounds with FDA approval. Of the pathways in other cellular systems, we now turn to the cell death mechanism triggered by these drugs in primary ALL. We tested moxidectin, ivermectin, and milbemycin in PDX-depleted samples for caspases 3 and 7 using CRISPR-mediated gene editing.
Under conditions of incompetent apoptosis, the cells were equally sensitive to moxidectin, the most potent anthelmintic agent of all, without differences from wild-type cells. In addition, suggesting a caspase-independent cell death mechanism, triple inactivation of Caspase3 / 7 and 6 or Caspase2 failed to rescue cells after moxidectin treatment.
Moxidectin increases the concentration of intracellular chloride and causes depolarization of the mitochondrial membrane in all cells. In roundworms, anthelmintics induce an outflow of chlorides by selectively binding the GABAA and glutamate chloride channels by increasing intracellular chloride concentrations. In mammalian cells lacking such glutamate chloride channels, Journal of Blood Oncology anthelmintics can bind to and modulate other ionotropic receptors, transmembrane ligands, including the receptor. receptor. Purinergic P2X (4).
Notably, MOMP is considered a point of no return for cell death and is capable of killing cells even in the absence of caspase activity in a phenomenon known as MOMP-induced caspase-independent cells. death. Moxidectin reduces the potential of the outer mitochondrial membrane of primary leukemic cells, which indicates a strong destabilization of mitochondria.
Following the hypothesis that activation of cell death by various mechanisms may reduce mortality in primary ALL, we investigated whether moxidectin could also sensitize dexamethasone, a major component of standard induction chemotherapy in ALL. Thus can help tp trat deadly blood cancer.
Sublethal moxidectin increased dexamethasone-mediated leukemic cell death, and we observed a marked synergistic effect of moxidectin and dexamethasone in the primary ALL sample, with a ZIP score of 2.4 out of 16 in 19 primary ALL cases. Anthelmintics induce caspase and RIPK1-independent cell death.
Moxidectin, ivermectin and milbemycin cause cell death in WT and caspases 3 and 7 KO ALL. Moxidectin causes cell death in WT ALL, C3 / C7KO, knockout caspase 3/7/2 and triple knockout caspase 3/7/6. Moxidectin, ivermectin and milbemycin cause cell death in WT and RIPK1KO ALL. Moxidectin causes cell death in WT, C3 / C7KO, RIPK1KO, and a combination of C3 / C7 and RIPK1 knockouts.
We have identified anthelmintics, ivermectin, moxidectin and milbemycin as new agents with high leukocyte resistance to refractory ALL. These compounds exert potent antileukemic effects ex vivo on primary leukaemia cells at low microscopic concentrations, expanding on previous studies describing this activity. ivermectin for acute myeloid leukaemia and oto treat deadly blood cancers.
Moxidectin causes the death of leukemic cells by increasing intracellular chloride and induction of the permeability of the outer mitochondrial membrane. The level of intracellular chloride in BR03 PDX cells was measured by the inhibition of the MQAE fluorescence signal after treatment with 3 μM moxidectin compared to vehicle control.
Quantification of intracellular chloride in vehicle-treated BR03 compared to cells treated with 1 μM, 2 μM and 3 M moxidectin or 1 μM and 3 M ivermectin for 2 or 4 hours. Quantitative estimates of N = 6 independent experiments represent the mean, combined t-test, * p-value 0.008; ** P-value 0.002.
The increased sensitivity of intracellular chlorides appears to exhibit different vulnerabilities of leukemic cells, which does not depend on the presence of apoptosis-inducing caspases 3 and 7 or the activation of the cell death mechanism replaced by necrosis. Emphasizing the importance of mitochondrial integrity for cell survival and death in leukaemia, the synergistic effect of intracellular chloride increase using moxidectin and BCL2 antagonism by navitoclax enhances the cell death mechanism.
The apoptosis and necrosis-independent ability of anthelmintics to kill cells underscore their potential as novel anti-leukemic agents, The antiparasitic agent ivermectin causes chlorine-dependent hyperpolarization of membranes and cell death in leukocytes. Moxidectin inhibits glioma cell viability, causing G0 / G1 cell cycle arrest and apoptosis.
A drug used to treat some common forms of breast cancer may offer a new treatment for a deadly blood cancer called myelofibrosis, according to a new study from the Centers for Disease Control and Prevention. Palbociclib can prevent bone marrow scarring that is not possible with current therapies for fibromyalgia. The combination of the drug with ruxolitinib provided additional benefits by restoring leukocyte and bone marrow counts to normal levels and significantly reducing enlarged spleen size in rats. New therapies for myelofibrosis are particularly needed because treatment with ruxolitinib did not significantly reduce myelofibrosis. and often lose effectiveness with prolonged use, the researchers note.
