====== Trifluoperazine ======

reported that radiation induces a glioma-initiating cell [[phenotype]], and identified trifluoperazine (TFP) as a compound that interferes with this phenotype conversion. TFP causes loss of radiation-induced Nanog mRNA expression, and activation of [[GSK3]] with consecutive posttranslational reduction in p-Akt, Sox2, and β-catenin protein levels. TFP did not alter the intrinsic radiation sensitivity of glioma-initiating cells (GICs). Continuous treatment with TFP and a single dose of radiation reduced the number of GICs in vivo and prolonged survival in syngeneic and patient-derived orthotopic xenograft (PDOX) mouse models of GBM. Our findings suggest that the combination of a dopamine receptor antagonist with radiation enhances the efficacy of RT in GBM by preventing radiation-induced phenotype conversion of radiosensitive non-GICs into treatment-resistant, induced GICs (iGICs)
((Bhat K, Saki M, Vlashi E, et al. The dopamine receptor antagonist trifluoperazine prevents phenotype conversion and improves survival in mouse models of glioblastoma. Proc Natl Acad Sci U S A. 2020;117(20):11085-11096. doi:10.1073/pnas.1920154117)).
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tested the anti-tumor effect of the BBB-penetrating antipsychotic trifluoperazine (TFP) on metastatic melanoma. H1 and Melmet1 human metastatic melanoma cell lines were used in vitro and in vivo. TFP effects on viability and toxicity were evaluated in proliferation and colony formation assays. Preclinical, therapeutic efficacy was evaluated in NOD/SCID mice, after intracardial injection of tumor cells. Molecular studies using immunohistochemistry, western blots, immunofluorescence and transmission electron microscopy were used to gain mechanistic insight into the biological activity of TFP. Our results showed that TFP decreased cell viability and proliferation, colony formation and spheroid growth in vitro. The drug also decreased tumor burden in mouse brains and prolonged animal survival after injection of tumor cells (53.0 days vs 44.5 days), TFP treated vs untreated animals, respectively (P < 0.01). At the molecular level, TFP treatment led to increased levels of LC3B and p62 in vitro and in vivo, suggesting an inhibition of autophagic flux. A decrease in LysoTracker Red uptake after treatment indicated impaired acidification of lysosomes. TFP caused accumulation of electron dense vesicles, an indication of damaged lysosomes, and reduced the expression of cathepsin B, a main lysosomal protease. Acridine orange and galectin-3 immunofluorescence staining were evidence of TFP induction of lysosomal membrane permeabilization. Finally, TFP was cytotoxic to melanoma brain metastases based on the increased release of lactate dehydrogenase into media. Through knockdown experiments, the processes of TFP-induced lysosomal membrane permeabilization and cell death appeared to be STAT3 dependent. In conclusion, our work provides a strong rationale for further clinical investigation of TFP as an adjuvant therapy for melanoma patients with metastases to the brain
((Zhang X, Ding K, Ji J, et al. Trifluoperazine prolongs the survival of experimental brain metastases by STAT3-dependent lysosomal membrane permeabilization. Am J Cancer Res. 2020;10(2):545-563. Published 2020 Feb 1.)).