The unique metabolic demands of cancer cells underscore potentially fruitful opportunities for drug discovery in the era of precision medicine. However, therapeutic targeting of cancer metabolism has led to surprisingly few new drugs to date. The neutral amino acid glutamine serves as a key intermediate in numerous metabolic processes leveraged by cancer cells including biosynthesis, cell signaling, and oxidative protection. Herein, we report the preclinical development of V-9302, a competitive small molecule antagonist of transmembrane glutamine flux, that selectively and potently targets the amino acid transporter ASCT2 (SLC1A5). Pharmacological blockade of ASCT2 with V-9302 resulted in attenuated cancer cell growth and proliferation, increased cell death, and increased oxidative stress, which collectively, contributed to anti-tumor responses in vitro and in vivo. Representing a new class of targeted therapy, this is the first study to demonstrate the utility of a pharmacological inhibitor of glutamine transport in oncology, laying a framework for paradigm-shifting therapies targeting cancer cell metabolism.
Cytogenetic information on chordomas is rudimentary and restricted to GTG-banding analysis of 26 cases worldwide. In this study, we present the chromosomal imbalances detected in a series of 16 chordomas (10 sacrococcyeal, five sphenooccipital, and one spinal) from 13 patients using comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH). On average, 3.2 losses and 4.2 gains were detected per tumor. The most common DNA copy number alterations were losses on chromosomal arms 3p (50%) and 1p (44%). Losses of 3p were detected in five of seven primary chordomas. Therefore, the loss of 3p might be an early event in chordoma genesis. The most common gains involved 7q (69%), 20 (50%), 5q (38%), and 12q (38%). Additionally, we raised the first human chordoma cell line, U-CH1, from a recurrence of a sacral chordoma. U-CH1 and its parent tumor had almost the same CGH profile. According to GTG-banding and multicolor FISH, U-CH1 has the following clonal chromosomal abnormalities: der(1)t(1;22), del(4), +del(5), +del(6), +7, del(9), del(10), +der(20)t(10;20), +21. Thus, the novel permanent human chordoma cell line U-CH1 has chordoma-typical cytogenetic aberrations. Our data suggest that tumor suppressor genes or mismatch repair genes (located at 1p31 and 3p14) and oncogenes (located in 7q36) might be involved in chordoma genesis.
Continued improvement of endoscopic techniques and instruments, together with good long-term results in endoscopically treated patients, have established this method as an alternative to microsurgical techniques and might even set a new standard for treatment.
T-type Ca2+ channel inhibitors hold tremendous therapeutic potential for the treatment of pain, epilepsy, sleep disorders, essential tremor and other neurological disorders; however, a lack of truly selective tools has hindered basic research, and selective tools from the pharmaceutical industry are potentially burdened with intellectual property (IP) constraints. Thus, an MLPCN high-throughput screen (HTS) was conducted to identify novel T-type Ca2+ channel inhibitors free from IP constraints, and freely available through the MLPCN, for use by the biomedical community to study T-type Ca2+ channels. While the HTS provided numerous hits, these compounds could not be optimized to the required level of potency to be appropriate tool compounds. Therefore, a scaffold hopping approach, guided by SurflexSim, ultimately afforded ML218 (CID 45115620) a selective T-Type Ca2+ (Cav3.1, Cav3.2, Cav3.3) inhibitor (Cav3.2, IC50 = 150 nM in Ca2+ flux; Cav3.2 IC50 = 310 nM and Cav3.3 IC50 = 270 nM, respectively in patch clamp electrophysiology) with good DMPK properties, acceptable in vivo rat PK and excellent brain levels. Electrophysiology studies in subthalamic nucleus (STN) neurons demonstrated robust effects of ML218 on the inhibition of T-Type calcium current, inhibition of low threshold spike and rebound burst activity. Based on the basal ganglia circuitry in Parkinson’s disease (PD), the effects of ML218 in STN neurons suggest a therapeutic role for T-type Ca2+ channel inhibitors, and ML218 was found to be orally efficacious in haloperidol-induced catalepsy, a preclinical PD model, with comparable efficacy to an A2A antagonist, a clinically validated PD target. ML218 proves to be a powerful new probe to study T-Type Ca2+ function in vitro and in vivo, and freely available.
Herein, we report the discovery of 2-amino-4-bis(aryloxybenzyl)aminobutanoic acids as novel inhibitors of ASCT2(SLC1A5)-mediated glutamine accumulation in mammalian cells. Focused library development led to two novel ASCT2 inhibitors that exhibit significantly improved potency compared with prior art in C6 (rat) and HEK293 (human) cells. The potency of leads reported here represents a 40-fold improvement over our most potent, previously reported inhibitor and represents, to our knowledge, the most potent pharmacological inhibitors of ASCT2-mediated glutamine accumulation in live cells. These and other compounds in this novel series exhibit tractable chemical properties for further development as potential therapeutic leads.
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