Cancer cell employs a microenvironmental neural signal transactivating nucleus-mitochondria coordination to acquire stemness

Cancer cell receives extracellular signal inputs to obtain a stem-like status,yet how tumor microenvironmental(TME)neural signals steer cancer stemness to establish the hierarchical tumor architectures remains elusive.Here,a pan-cancer transcriptomic screening for 10852 samples of 33 TCGA cancer types reveals that cAMP-responsive element(CRE)transcription factors are convergent activators for cancer stemness.Deconvolution of transcriptomic profiles,specification of neural markers and illustration of norepinephrine dynamics uncover a bond between TME neural signals and cancer-cell CRE activity.Specifically,neural signal norepinephrine potentiates the stemness of proximal cancer cells by activating cAMP-CRE axis,where ATF1 serves as a conserved hub.Upon activation by norepinephrine,ATF1 potentiates cancer stemness by coordinated trans-activation of both nuclear pluripotency factors MYC/NANOG and mitochondrial biogenesis regulators NRF1/TFAM,thereby orchestrating nuclear reprograming and mitochondrial rejuvenating.Accordingly,single-cell transcriptomes confirm the coordinated activation of nuclear pluripotency with mitochondrial biogenesis in cancer stem-like cells.These findings elucidate that cancer cell acquires stemness via a norepinephrine-ATF1 driven nucleus-mitochondria collaborated program,suggesting a spatialized stemness acquisition by hijacking microenvironmental neural signals.

CRISPR/Cas9 screening identifies a kinetochore-microtubule dependent mechanism for Aurora-A inhibitor resistance in breast cancer

Background:Overexpression of Aurora-A(AURKA)is a feature of breast cancer and associates with adverse prognosis.The selective Aurora-A inhibitor alisertib(MLN8237)has recently demonstrated promising antitumor responses as a single agent in various cancer types but its phase III clinical trial was reported as a failure since MLN8237 did not show an apparent effect in prolonging the survival of patients.Thus,identification of potential targets that could enhance the activity of MLN8237 would provide a rationale for drug combination to achieve better therapeutic outcome.Methods:Here,we conducted a systematic synthetic lethality CRISPR/Cas9 screening of 507 kinases using MLN8237 in breast cancer cells and identified a number of targetable kinases that displayed synthetic lethality interactions with MLN8237.Then,we performed competitive growth assays,colony formation assays,cell viability assays,apoptosis assays,and xenograft murine model to evaluate the synergistic therapeutic effects of Haspin(GSG2)depletion or inhibition with MLN8237.For mechanistic studies,immunofluorescence was used to detect the state of microtubules and the localization of Aurora-B and mitotic centromere-associated kinesin(MCAK).Results:Among the hits,we observed that Haspin depletion or inhibition marginally inhibited breast cancer cell growth but could substantially enhance the killing effects of MLN8237.Mechanistic studies showed that co-treatment with Aurora-A and Haspin inhibitors abolished the recruitment of Aurora-B and mitotic centromere-associated kinesin(MCAK)to centromeres which were associated with excessive microtubule depolymerization,kinetochore-microtubule(KT-MT)attachment failure,and severe mitotic catastrophe.We further showed that the combination of MLN8237 and the Haspin inhibitor CHR-6494 synergistically reduced breast cancer cell viability and significantly inhibited both in vitro and in vivo tumor growth.Conclusions:These findings establish Haspin as a synthetic lethal target and demonstrate CHR-6494 as a potential combinational drug for promoting the therapeutic effects of MLN8237 on breast cancer.

Targeting cancer cell plasticity by HDAC inhibition to reverse EBV-induced dedifferentiation in nasopharyngeal carcinoma

Application of differentiation therapy targeting cellular plasticity for the treatment of solid malignancies has been lagging.Nasopharyngeal carci noma(NPC)is a distinctive cancer with poor differe ntiatio n and high prevalenee of Epstein-Barr virus(EBV)infection.Here,we show that the expressi on of EBV latent protein LMP1 in duces dediffere ntiated and stem-like status with high plasticity through the transcriptional inhibition of CEBPA.Mechanistically,LMP1 upregulates STAT5A and recruits HDAC 1/2 to the CEBPA locus to reduce its histone acetylation.HDAC inhibition restored CEBPA expression,reversing cellular dedifferentiation and stem-like status in mouse xeno graft models.These fin dings provide a novel mecha nistic epigenetic-based in sight into virus-induced cellular plasticity and propose a promising concept of differentiation therapy in solid tumor by using HDAC inhibitors to target cellular plasticity.