Research On Novel NFAT Signaling Pathway Inhibitors And Their Antiglioblastoma Activity

Glioblastoma multiforme（GBM）is the most common primary tumor in the central nervous system,accounting for approximately 50%of all gliomas and up to 15%of all brain tumors.Glioblastoma is a type of malignant tumors with very poor prognosis,resulting in 95%of GBM patients with a survival period of less than two years.Attributing to its high infiltrative growth behavior,it is almost impossible to remove the tumor lesion completely through surgical resection without affecting the normal brain function.As a result,it is easy to relapse after operation,and especially the quality of patents’life was greatly reduced.Therefore,effective chemotherapeutic drugs are important for improving patient survival.Currently,temozolomide（TMZ）as well as other several alkylating agents are applied as the first-line drugs in clinic.However,they are prone to acquire chemoresistance after long-term administration.Hence,people are tried to develop novel drugs targeting other proteins,or introduce immunotherapy and targeted therapy to treat GBM.Although some cases are successful,the patients’survival still has no substantial improvement.Therefore,novel effective drugs or strategies remains an urgent need in clinic.Nuclear factor of activated T cells（NFAT）is an important type of transcription factor,which plays critical role in various cellular processes,embryonic development and organogenesis.However,recent years,it was found that NFAT was upregulated or hyperactivated in many types of tumors,including GBM,which was correlated with tumor’s poor prognosis.Meanwhile,many of NFAT downstream signals such as MMPs and VEGFR were complicated in tumorigenesis and tumor progression.Therefore,as a potential anti-tumor drug target,targeting NFAT signal pathway can provide a new strategy for GBM treatment.The FDA approved drugs are the precious wealth of human and their pharmacodynamic profile,safety have been well characterized.Developing new drugs by repurposing these drugs for a new indication can effectively reduce the research time frame.Therefore,in this study,we adopted drug repurposing strategy to identify novel NFAT signal pathway inhibitor.Besides,using the methods of traditional medicinal chemistry and rational drug design,a series of YZ85 derivatives were designed and synthesized,hoping to explore an effective and novel drug candidate with full intellectual property for GBM therapy.The contents were as follows:1.Developing new drugs by repurposing old drugs for new tricks,NFAT signaling pathway inhibitors were screened for the treatment of GBM tumors.After screening a set of 93 FDA approved drugs with simple structures,eight drugs were identified as potent NFAT signal pathway inhibitor.Therein,PIM displayed the highest inhibitory activity,with a IC₅₀ value of 6.47μM.Further study revealed that PIM suppressed STIM1 puncta formation to inhibit Calcium release-activated channels and subsequent NFAT activity.Experimental results show that PIM can induce cell cycle arrest at G1/S phase and promote cell apoptosis at the cellular level,thereby significantly impede the proliferation,migration,division,mobility of U87 glioblastoma cells.In vivo,the growth of subcutaneous and orthotopic glioblastoma xenografts were pronouncedly suppressed by PIM.Most notably,PIM was administrated by gavage,indicating that PIM can cross the blood-brain barrier,thereby ensuring the therapeutic effect in future clinical trials.Omics studies unbiasedly revealed the molecular mechanism for its antitumor activity including suppressing ATR/RB/E2F,MYC and Aurora A/B signaling,thereby impairing cell cycle progression,DNA replication and base metabolism.2.Exploration of highly active sulfonamides NFAT signaling pathway inhibitors based on structural modification strategies of lead compounds.In this part,a potent NFAT signal pathway inhibitor YZ85 with sulfonamide structure was used as a leading compound,and 19 YZ85derivatives were designed and synthesized.Subsequently,the activity of these compounds on glioblastoma cell U87 were evaluated.The results showed that YZ85 derivatives can obviously suppressed the glioblastoma growth and are expected to develop into effective anti-tumor drugs.In summary,this study revealed that NFAT signaling pathway is a promising target for GBM therapy.PIM was just approved for marketing in 2016,and there are few studies on its anti-tumor activity.This study was the first time to report the therapeutic potential of PIM for GBM tumors and its new anti-tumor mechanism,including inhibition of the NFAT signaling pathway as well as ATR/RB/E2F,MYC and Aurora A/B signaling etc..In future study,combination of PIM with TMZ or m TORC1 inhibitors will also be considered,ultimately promoting PIM’s application for GBM therapy.In addition,the structure of the YZ85 derivative will be continued to be optimized to improve their activity.