1.Activated natural killer cells suppress myelopoiesis in mice with severe combined immunodeficiency.
Pisa P1, Sitnicka E, Hansson M. Scand J Immunol. 1993 Apr;37(4):529-32.
The in vivo effect of natural killer (NK) cell activation on autologous myelopoiesis was studied in an environment deficient of functional T and B cells. Administration of 3,6-bis[2-(Dimethylamino)-ethoxy]-9H-xanthen-9-one dihydrochloride) Tilorone) or recombinant interleukin-2 (rIL-2) to mice with severe combined immunodeficiency (C.B.-17 scid/scid) resulted in an increase in YAC-1 lysis by their splenocytes as well as bone marrow cells. Recombinant IL-2 furthermore led to a fivefold increase in the cellularity of the spleen. When assayed against human NK/lymphokine-activated killer (LAK) target, K562 cell line, the IL-2-activated mouse cells exhibited no cytotoxicity across the species barrier. Both agents induced a profound suppression of myelopoietic progenitor cells as measured in a 7-day granulocyte-macrophage colony forming cell (GM-CFC) assay. We conclude that the presence of neither functional T nor B cells is necessary for NK cells to mediate inhibition of myelopoiesis in the autologous host.
2.Effect of tilorone and its analogues on the change of mitochondrial potential of rat hepatocytes.
Zholobak NM1, Kavok NS, Bogorad-Kobelska OS, Borovoy IA, Malyukina MY, Spivak MY. Fiziol Zh. 2012;58(2):39-43.
The influence of tilorone dihydrochloride and its analogues--diphenyl derivatives on the changes of transmembrane potential of mitochondrial membranes of the isolated rat hepatocytes has been estimated. Authors have shown a significant increase in mitochondrial potential thirty minutes after the introduction of the test compounds to the cells using the fluorescent probe JC-1. These results indicate the rapid activation with tilorone and its analog--dihydrochloryde 4,4'-bis-[2-(diethylamino)ethoxy]diphenyl--of the RLR signaling pathway. The final stage of this pathway is the cell production of IFN type I. The authors concluded that there is an increasing of the organelles resistance to the extra/intracellular damaging agents under the influence of the test compounds.
3.Small-molecule screening of PC3 prostate cancer cells identifies tilorone dihydrochloride to selectively inhibit cell growth based on cyclin-dependent kinase 5 expression.
Wissing MD1, Dadon T1, Kim E1, Piontek KB1, Shim JS2, Kaelber NS1, Liu JO2, Kachhap SK1, Nelkin BD1. Oncol Rep. 2014 Jul;32(1):419-24. doi: 10.3892/or.2014.3174. Epub 2014 May 13.
Cyclin-dependent kinase 5 (CDK5) is a potential target for prostate cancer treatment, the enzyme being essential for prostate tumor growth and formation of metastases. In the present study, we identified agents that target prostate cancer cells based on CDK5 expression. CDK5 activity was suppressed by transfection of PC3 prostate cancer cells with a dominant-negative construct (PC3 CDK5dn). PC3 CDK5dn and PC3 control cells were screened for compounds that selectively target cells based on CDK5 expression, utilizing the Johns Hopkins Drug Library. MTS proliferation, clonogenic and 3D growth assays were performed to validate the selected hits. Screening of 3,360 compounds identified rutilantin, ethacridine lactate and cetalkonium chloride as compounds that selectively target PC3 control cells and a tilorone analog as a selective inhibitor of PC3 CDK5dn cells. A PubMed literature study indicated that tilorone may have clinical use in patients.
4.A clinical flow cytometric biomarker strategy: validation of peripheral leukocyte phospholipidosis using Nile red.
Halstead BW1, Zwickl CM, Morgan RE, Monteith DK, Thomas CE, Bowers RK, Berridge BR. J Appl Toxicol. 2006 Mar-Apr;26(2):169-77.
Phospholipidosis, or intracellular accumulation of phospholipids, is caused by specific classes of xenobiotics. This phenomenon represents a challenge for risk assessment that could benefit from the use of biomarkers in the clinical development of new drug candidates. Flow cytometry, coupled with the lipophilic fluoroprobe Nile red, was correlated to histopathology, electron microscopy and inorganic phosphorus detection to validate the utility of this method for monitoring phospholipidosis in peripheral blood leukocytes. Replicate studies with model test compounds were conducted in which F344 rats were given 4 or 7 doses of either maprotiline hydrochloride, imipramine hydrochloride, tilorone dihydrochloride, amikacin hydrate or vehicle control. Transmission electron and light microscopy were used to examine peripheral blood smears and tissue samples for the presence of cytoplasmic vacuoles. Unstained and Nile red stained lysed peripheral blood samples were acquired for analysis using a FACScan flow cytometer.