High-throughput sensitive screening of small molecule modulators of microexon alternative splicing using dual Nano and Firefly luciferase reporters.

Disruption of alternative splicing frequently causes or contributes to human diseases and disorders. Consequently, there is a need for efficient and sensitive reporter assays capable of screening chemical libraries for compounds with efficacy in modulating important splicing events. Here, we describe a screening workflow employing dual Nano and Firefly luciferase alternative splicing reporters that affords efficient, sensitive, and linear detection of small molecule responses. Applying this system to a screen of ~95,000 small molecules identified compounds that stimulate or repress the splicing of neuronal microexons, a class of alternative exons often disrupted in autism and activated in neuroendocrine cancers. One of these compounds rescues the splicing of several analyzed microexons in the cerebral cortex of an autism mouse model haploinsufficient for Srrm4, a major activator of brain microexons. We thus describe a broadly applicable high-throughput screening system for identifying candidate splicing therapeutics, and a resource of small molecule modulators of microexons with potential for further development in correcting aberrant splicing patterns linked to human disorders and disease.

Loss of the stress sensor GADD45A promotes stem cell activity and ferroptosis resistance in LGR4/HOXA9-dependent AML.

ABSTRACT: The overall prognosis of acute myeloid leukemia (AML) remains dismal, largely because of the inability of current therapies to kill leukemia stem cells (LSCs) with intrinsic resistance. Loss of the stress sensor growth arrest and DNA damage-inducible 45 alpha (GADD45A) is implicated in poor clinical outcomes, but its role in LSCs and AML pathogenesis is unknown. Here, we define GADD45A as a key downstream target of G protein-coupled receptor (LGR)4 pathway and discover a regulatory role for GADD45A loss in promoting leukemia-initiating activity and oxidative resistance in LGR4/HOXA9-dependent AML, a poor prognosis subset of leukemia. Knockout of GADD45A enhances AML progression in murine and patient-derived xenograft (PDX) mouse models. Deletion of GADD45A induces substantial mutations, increases LSC self-renewal and stemness in vivo, and reduces levels of reactive oxygen species (ROS), accompanied by a decreased response to ROS-associated genotoxic agents (eg, ferroptosis inducer RSL3) and acquisition of an increasingly aggressive phenotype on serial transplantation in mice. Our single-cell cellular indexing of transcriptomes and epitopes by sequencing analysis on patient-derived LSCs in PDX mice and subsequent functional studies in murine LSCs and primary AML patient cells show that loss of GADD45A is associated with resistance to ferroptosis (an iron-dependent oxidative cell death caused by ROS accumulation) through aberrant activation of antioxidant pathways related to iron and ROS detoxification, such as FTH1 and PRDX1, upregulation of which correlates with unfavorable outcomes in patients with AML. These results reveal a therapy resistance mechanism contributing to poor prognosis and support a role for GADD45A loss as a critical step for leukemia-initiating activity and as a target to overcome resistance in aggressive leukemia.

Factor XI Inhibition for the Prevention of Catheter-Associated Thrombosis in Patients With Cancer Undergoing Central Line Placement: A Phase 2 Clinical Trial.

BACKGROUND: Despite the ubiquitous utilization of central venous catheters in clinical practice, their use commonly provokes thromboembolism. No prophylactic strategy has shown sufficient efficacy to justify routine use. Coagulation factors FXI (factor XI) and FXII (factor XII) represent novel targets for device-associated thrombosis, which may mitigate bleeding risk. Our objective was to evaluate the safety and efficacy of an anti-FXI mAb (monoclonal antibody), gruticibart (AB023), in a prospective, single-arm study of patients with cancer receiving central line placement. METHODS: We enrolled ambulatory cancer patients undergoing central line placement to receive a single dose of gruticibart (2 mg/kg) administered through the venous catheter within 24 hours of placement and a follow-up surveillance ultrasound at day 14 for evaluation of catheter thrombosis. A parallel, noninterventional study was used as a comparator. RESULTS: In total, 22 subjects (n=11 per study) were enrolled. The overall incidence of catheter-associated thrombosis was 12.5% in the interventional study and 40.0% in the control study. The anti-FXI mAb, gruticibart, significantly prolonged the activated partial thromboplastin time in all subjects on day 14 compared with baseline (P<0.001). Gruticibart was well tolerated and without infusion reactions, drug-related adverse events, or clinically relevant bleeding. Platelet flow cytometry demonstrated no difference in platelet activation following administration of gruticibart. T (thrombin)-AT (antithrombin) and activated FXI-AT complexes increased following central line placement in the control study, which was not demonstrated in our intervention study. CRP (C-reactive protein) did not significantly increase on day 14 in those who received gruticibart, but it did significantly increase in the noninterventional study. CONCLUSIONS: FXI inhibition with gruticibart was well tolerated without any significant adverse or bleeding-related events and resulted in a lower incidence of catheter-associated thrombosis on surveillance ultrasound compared with the published literature and our internal control study. These findings suggest that targeting FXI could represent a safe intervention to prevent catheter thrombosis. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04465760.

TraumaICDBERT, A Natural Language Processing Algorithm to Extract Injury ICD-10 Diagnosis Code from Free Text.

OBJECTIVE: To develop and validate TraumaICDBERT, a natural language processing algorithm to predict injury ICD-10 diagnosis codes from trauma tertiary survey notes. SUMMARY BACKGROUND DATA: The adoption of ICD-10 diagnosis codes in clinical settings for injury prediction is hindered by the lack of real-time availability. Existing natural language processing algorithms have limitations in accurately predicting injury ICD-10 diagnosis codes. METHODS: Trauma tertiary survey notes from hospital encounters of adults between January 2016 and June 2021 were used to develop and validate TraumaICDBERT, an algorithm based on BioLinkBERT. The performance of TraumaICDBERT was compared to Amazon Web Services Comprehend Medical, an existing natural language processing tool. RESULTS: A dataset of 3,478 tertiary survey notes with 15,762 4-character injury ICD-10 diagnosis codes was analyzed. TraumaICDBERT outperformed Amazon Web Services Comprehend Medical across all evaluated metrics. On average, each tertiary survey note was associated with 3.8 (standard deviation: 2.9) trauma registrar-extracted 4-character injury ICD-10 diagnosis codes. CONCLUSIONS: TraumaICDBERT demonstrates promising initial performance in predicting injury ICD-10 diagnosis codes from trauma tertiary survey notes, potentially facilitating the adoption of downstream prediction tools in clinical settings.

Melasma treatment with a 1064 nm, picosecond-domain laser with a fractionated multibeam lens array.

BACKGROUND AND OBJECTIVES: Picosecond-domain lasers have been fitted with fractionated optics for dermal remodeling. This study evaluates the safety and efficacy of a multiwavelength picosecond-domain laser, using a 1064 nm multibeam lens array, for improving the appearance of melasma. STUDY DESIGN/MATERIALS AND METHODS: Twenty adults with a clinical diagnosis of melasma were enrolled and received 4 monthly 1064-nm, 450 ps laser treatments delivered with a 10 × 10 fractional array of 150 µm microbeams. Cosmetic units with melasma were treated with fluences ranging from 1.7 to 2.9 mJ/microbeam with a repetition rate of 6 Hz. Treatment effect was evaluation of digital images by dermatologists blinded as to the treatment conditions, comparing baseline and 3- and 8-month post-treatment images. Modified melasma area and severity index (mMASI) scores were determined by the study investigator based on clinical photography. Subject self-assessment of treatment effects was also recorded. RESULTS: Blinded reviewers correctly identified the post-treatment image in 16 of the 20 image sets (80%). Ratings demonstrated statistically significant (p < 0.001) improvement on an 11-point scale at both the 3- and 8-month timepoints for a mean improvement of 3.7 point (range -8 to 10) or 37% improvement at the 3-month follow-up, and 2.7 (range -8 to 9) or 27% at the 8-month follow-up for all subjects. The average mMASI score showed highly significant reduction at both the 3- and 8-month follow-ups compared to baseline (p < 0.01). Most subjects (90%) were satisfied with the treatment outcome in melasma at both follow-ups, which is consistent with the treatment outcome and mMASI scores. CONCLUSION: The fractionated, picosecond-domain, 1064 nm laser is safe and effective for improving melasma and should be considered as an adjunct to topical treatment regimens and sun-protection for management of melasma.

Estrogen-based hormonal therapy and the risk of thrombosis in COVID-19 patients.

OBJECTIVE: Estrogen-containing contraceptives and hormone replacement therapy are used commonly, however, the risks of venous and arterial thrombosis imparted by such medications during COVID-19 infection or other similar viral infections remain undescribed. METHODS: To assess the risk of venous and arterial thrombosis in patients receiving oral estrogen-containing therapy (ECT) with COVID-19 as compared to those receiving non-estrogen-based hormonal therapy, we conducted a multicenter cohort study of 991 patients with confirmed COVID-19 infection, 466 receiving estrogen-containing hormonal therapy, and 525 receiving progestin-only or topical therapy. RESULTS: The use of estrogen-containing therapy was found to significantly increase the risk of venous thromboembolism (VTE) following COVID-19 diagnosis after controlling for age (HR 5.46 [95% CI 1.12-26.7, p = .036]). This risk was highest in patients over age 50, with 8.6% of patients receiving estrogen-containing therapy diagnosed with VTE compared to 0.9% of those receiving non-estrogen-based therapies (p = .026). The risk of arterial thrombosis was not significantly associated with oral estrogen use. CONCLUSIONS: These results suggest that estrogen-containing therapy is associated with a significantly increased risk of VTE in COVID-19 patients, especially in older individuals. These findings may guide provider counseling and management of patients with COVID-19 on estrogen-containing therapy.

Identifying Core Journals in Otolaryngology: A Bibliometric Analysis.

OBJECTIVES: As research in otolaryngology continues to expand rapidly, it is important to identify core journals to keep clinicians updated with the latest advances. This study is the first to characterize core journals in otolaryngology. METHODS: Using h-index and impact factor (IF), the top 15 NLM-indexed otolaryngology journals were selected for analysis. The references from all articles published in these journals in one randomized quarter were compiled into a citation rank list, with the most cited journal ranked the highest. Citation zonal distribution analysis was conducted to identify the zonal distribution of otolaryngology journals. RESULTS: A total of 3150 journals containing 26876 articles were cited in otolaryngology literature in April-June 2019. Laryngoscope was the most cited journal containing 1762 citations. IF is significantly associated with the h-index for the top 10 otolaryngology journals (p = 0.032). Three core journal zones were identified, with Zone 1 containing 8 journals, Zone 2 containing 36 journals, and Zone 3 containing 189 journals. A linear relationship between the log journal rank for Zones 1-3 and a cumulative number of citations was found (R2 = 0.9948). CONCLUSION: Eight core journals for otolaryngology were identified: Laryngoscope, Otolaryngology-Head and Neck Surgery, Otology & Neurotology, JAMA Otolaryngology-Head & Neck Surgery, Head & Neck, European Archives of Oto-Rhino-Laryngology, International Journal of Pediatric Otorhinolaryngology, Annals of Otology, Rhinology & Laryngology. In the face of rapidly evolving research and a multitude of journals, the high citation density within these core journals highlights their utility in updating busy clinicians. LEVEL OF EVIDENCE: NA Laryngoscope, 133:3346-3352, 2023.

Characteristics and Outcomes in Pediatric Versus Adult Craniopharyngiomas: A Systematic Review and Meta-Analysis.

BACKGROUND: Craniopharyngiomas account for 1.2% to 4.6% of all intracranial tumors. Although age at presentation is distributed bimodally, with a pediatric peak occurring between 5 and 15 years and an adult peak between 50 and 70 years, presentation, treatment, and outcome differences between these two craniopharyngioma populations have not been thoroughly characterized. OBJECTIVE: To compare treatments and outcomes between adult and pediatric craniopharyngiomas. METHODS: This is a systematic review and meta-analysis. Web of Science, MEDLINE, and Scopus databases were searched for primary studies reporting postoperative complications, functional outcomes, recurrence, and overall survival in patients with craniopharyngioma undergoing surgery. RESULTS: The search yielded 1,202 unique articles, of which 106 (n=4,202 patients) met criteria for qualitative synthesis and 23 (n=735 patients) met criteria for meta-analysis. Compared with adult, pediatric craniopharyngiomas were less likely to present with visual defects (odds ratio [OR] 0.54, 95% CI 0.36-0.80) or cognitive impairment (OR 0.29, 95% CI 0.12-0.71) and more likely with headaches (OR 2.08, 95% CI 1.16-3.73). Children presented with significantly larger tumors compared with adults (standardized mean difference 0.68, 95% CI 0.38-0.97). Comparing functional outcomes, pediatric patients sustained higher rates of permanent diabetes insipidus (OR 1.70, 95% CI 1.13-2.56), obesity (OR 3.15, 95% CI 1.19-8.31), and cranial nerve and/or neurological defects (OR 4.87, 95% CI 1.78-13.31) than adults. No significant differences were found in rates of postoperative cerebrospinal fluid leak, overall or progression-free survival, or recurrence. CONCLUSION: Adult and pediatric craniopharyngiomas seem to have fundamental differences in clinical presentation and functional outcomes. These patients frequently require multimodality treatment and are best managed with a multidisciplinary team and an individualized approach.

Evaluation of first trimester ultrasound fetal biometry ratios femur length/biparietal diameter, femur length/abdominal circumference and femur length/foot for the screening of skeletal dysplasia.

OBJECTIVE: Skeletal dysplasia is usually apparent in the second trimester. First trimester femur-length/biparietal diameter (FL/BPD), FL/abdominal circumference (AC) and FL/foot for the screening of skeletal dysplasia were evalauted. METHOD: Case-control study: pregnancies with molecular confirmation of skeletal dysplasia undergoing nuchal translucency (January_2007-December_2021). Controls included pregnancies without fetal abnormalities. Performance of FL/BPD, FL/AC and FL/foot was evaluated by receiver operating characteristic curves. RESULTS: Twenty-eight skeletal dysplasia cases were identified; 17 (60.71%) corresponded to lethal types. Compared to 184 controls, cases had a lower median FL/BPD (0.34 [IQR 0.30-0.38] vs. 0.44 [IQR 0.39-0.48]; p < 0.001), FL/AC (0.13 [IQR 0.09-0.15] vs. 0.15 [IQR 0.13-0.16]; p = 0.001) and FL/foot (0.84 [IQR 0.76-0.91] vs. 1.01 [IQR 0.94-1.11]; p < 0.001). FL/BPD and FL/foot ratios had a superior area under the curve (0.846 and 0.853, respectively) than FL/AC (0.64). The probability of diagnosing skeletal dysplasia increased at least 9-fold if FL/BPD <0.376 (OR 26.05, 95% CI 9.79-69.3; p < 0.001) and 14-fold if FL/foot <0.891 (OR 39.46, 95% CI 14.17-109.9; p < 0.001). Low FL/BPD and FL/foot were associated significantly with lethal types compared to viable skeletal dysplasia. CONCLUSIONS: First trimester FL/BPD and FL/foot may be of clinical utility in the detection of skeletal dysplasia especially when there is another suspicious sonographic sign or when there is a relevant family history before overt second trimester sonographic markers become apparent.

A MYC-ZNF148-ID1/3 regulatory axis modulating cancer stem cell traits in aggressive breast cancer.

The MYC proto-oncogene (MYC) is one of the most frequently overexpressed genes in breast cancer that drives cancer stem cell-like traits, resulting in aggressive disease progression and poor prognosis. In this study, we identified zinc finger transcription factor 148 (ZNF148, also called Zfp148 and ZBP-89) as a direct target of MYC. ZNF148 suppressed cell proliferation and migration and was transcriptionally repressed by MYC in breast cancer. Depletion of ZNF148 by short hairpin RNA (shRNA) and CRISPR/Cas9 increased triple-negative breast cancer (TNBC) cell proliferation and migration. Global transcriptome and chromatin occupancy analyses of ZNF148 revealed a central role in inhibiting cancer cell de-differentiation and migration. Mechanistically, we identified the Inhibitor of DNA binding 1 and 3 (ID1, ID3), drivers of cancer stemness and plasticity, as previously uncharacterized targets of transcriptional repression by ZNF148. Silencing of ZNF148 increased the stemness and tumorigenicity in TNBC cells. These findings uncover a previously unknown tumor suppressor role for ZNF148, and a transcriptional regulatory circuitry encompassing MYC, ZNF148, and ID1/3 in driving cancer stem cell traits in aggressive breast cancer.

A nuclear cAMP microdomain suppresses tumor growth by Hippo pathway inactivation.

Cyclic AMP (cAMP) signaling is localized to multiple spatially distinct microdomains, but the role of cAMP microdomains in cancer cell biology is poorly understood. Here, we present a tunable genetic system that allows us to activate cAMP signaling in specific microdomains. We uncover a nuclear cAMP microdomain that activates a tumor-suppressive pathway in a broad range of cancers by inhibiting YAP, a key effector protein of the Hippo pathway, inside the nucleus. We show that nuclear cAMP induces a LATS-dependent pathway leading to phosphorylation of nuclear YAP solely at serine 397 and export of YAP from the nucleus with no change in YAP protein stability. Thus, nuclear cAMP inhibition of nuclear YAP is distinct from other known mechanisms of Hippo regulation. Pharmacologic targeting of specific cAMP microdomains remains an untapped therapeutic approach for cancer; thus, drugs directed at the nuclear cAMP microdomain may provide avenues for the treatment of cancer.

Multimodal opioid-sparing pain management for emergent cesarean delivery under general anesthesia: a quality improvement project.

BACKGROUND: Opioid-sparing multimodal analgesic approach has been shown to provide effective postoperative pain relief and reduce postoperative opioid consumption and opioid-associated adverse effects. While many studies have evaluated analgesic strategies for elective cesarean delivery, few studies have investigated analgesic approaches in emergent cesarean deliveries under general anesthesia. The primary aim of this quality improvement project is to evaluate opioid consumption with the use of a multimodal opioid-sparing pain management pathway in patients undergoing emergent cesarean delivery under general anesthesia. METHODS: Seventy-two women (age > 16 years) undergoing emergent cesarean delivery under general anesthesia before (n = 36) and after (n = 36) implementation of a multimodal opioid-sparing pain management pathway were included. All patients received a standardized general anesthetic. Prior to implementation of the pathway, postoperative pain management was primarily limited to intravenous patient-controlled opioid administration. The new multimodal pathway included scheduled acetaminophen and non-steroidal anti-inflammatory medications and ultrasound-guided classic lateral transversus abdominis plane blocks with postoperative opioids reserved only for rescue analgesia. Data obtained from electronic records included demographics, intraoperative opioid use, and pain scores and opioid consumption upon arrival to the recovery room, at 2, 6, 12, 24, 48, and 72 h postoperatively. RESULTS: Patients receiving multimodal opioid sparing analgesia (AFTER group) had lower opioid use for 72 h, postoperatively. Only 2 of the 36 patients (5.6%) in the AFTER group required intravenous opioids through patient-controlled analgesia while 30 out of 36 patients (83.3%) in the BEFORE group required intravenous opioids. CONCLUSIONS: Multimodal opioid-sparing analgesia is associated with reduced postoperative opioid consumption after emergent cesarean delivery.

A laser powder bed fusion system for operando synchrotron x-ray imaging and correlative diagnostic experiments at the Stanford Synchrotron Radiation Lightsource.

Laser powder bed fusion (LPBF) is a highly dynamic multi-physics process used for the additive manufacturing (AM) of metal components. Improving process understanding and validating predictive computational models require high-fidelity diagnostics capable of capturing data in challenging environments. Synchrotron x-ray techniques play a vital role in the validation process as they are the only in situ diagnostic capable of imaging sub-surface melt pool dynamics and microstructure evolution during LPBF-AM. In this article, a laboratory scale system designed to mimic LPBF process conditions while operating at a synchrotron facility is described. The system is implemented with process accurate atmospheric conditions, including an air knife for active vapor plume removal. Significantly, the chamber also incorporates a diagnostic sensor suite that monitors emitted optical, acoustic, and electronic signals during laser processing with coincident x-ray imaging. The addition of the sensor suite enables validation of these industrially compatible single point sensors by detecting pore formation and spatter events and directly correlating the events with changes in the detected signal. Experiments in the Ti-6Al-4V alloy performed at the Stanford Synchrotron Radiation Lightsource using the system are detailed with sufficient sampling rates to probe melt pool dynamics. X-ray imaging captures melt pool dynamics at frame rates of 20 kHz with a 2 µm pixel resolution, and the coincident diagnostic sensor data are recorded at 470 kHz. This work shows that the current system enables the in situ detection of defects during the LPBF process and permits direct correlation of diagnostic signatures at the exact time of defect formation.

Visualization of endogenous p27 and Ki67 reveals the importance of a c-Myc-driven metabolic switch in promoting survival of quiescent cancer cells.

Rationale: Recurrent and metastatic cancers often undergo a period of dormancy, which is closely associated with cellular quiescence, a state whereby cells exit the cell cycle and are reversibly arrested in G0 phase. Curative cancer treatment thus requires therapies that either sustain the dormant state of quiescent cancer cells, or preferentially, eliminate them. However, the mechanisms responsible for the survival of quiescent cancer cells remain obscure. Methods: Dual genome-editing was carried out using a CRISPR/Cas9-based system to label endogenous p27 and Ki67 with the green and red fluorescent proteins EGFP and mCherry, respectively, in melanoma cells. Analysis of transcriptomes of isolated EGFP-p27highmCherry-Ki67low quiescent cells was conducted at bulk and single cell levels using RNA-sequencing. The extracellular acidification rate and oxygen consumption rate were measured to define metabolic phenotypes. SiRNA and inducible shRNA knockdown, chromatin immunoprecipitation and luciferase reporter assays were employed to elucidate mechanisms of the metabolic switch in quiescent cells. Results: Dual labelling of endogenous p27 and Ki67 with differentiable fluorescent probes allowed for visualization, isolation, and analysis of viable p27highKi67low quiescent cells. Paradoxically, the proto-oncoprotein c-Myc, which commonly drives malignant cell cycle progression, was expressed at relatively high levels in p27highKi67low quiescent cells and supported their survival through promoting mitochondrial oxidative phosphorylation (OXPHOS). In this context, c-Myc selectively transactivated genes encoding OXPHOS enzymes, including subunits of isocitric dehydrogenase 3 (IDH3), whereas its binding to cell cycle progression gene promoters was decreased in quiescent cells. Silencing of c-Myc or the catalytic subunit of IDH3, IDH3α, preferentially killed quiescent cells, recapitulating the effect of treatment with OXPHOS inhibitors. Conclusion: These results establish a rigorous experimental system for investigating cellular quiescence, uncover the high selectivity of c-Myc in activating OXPHOS genes in quiescent cells, and propose OXPHOS targeting as a potential therapeutic avenue to counter cancer cells in quiescence.

The Emerging Roles of RNA m6A Methylation and Demethylation as Critical Regulators of Tumorigenesis, Drug Sensitivity, and Resistance.

RNA N6 -methyladenosine (m6A) modification occurs in approximately 25% of mRNAs at the transcriptome-wide level. RNA m6A is regulated by the RNA m6A methyltransferases methyltransferase-like 3 (METTL3), METTL14, and METTL16 (writers), demethylases FTO and ALKBH5 (erasers), and binding proteins YTHDC1-2, YTHDF1-3, IGF2BP1-3, and SND1 (readers). These RNA m6A modification proteins are frequently upregulated or downregulated in human cancer tissues and are often associated with poor patient prognosis. By modulating pre-mRNA splicing, mRNA nuclear export, decay, stability, and translation of oncogenic and tumor suppressive transcripts, RNA m6A modification proteins regulate cancer cell proliferation, survival, migration, invasion, tumor initiation, progression, metastasis, and sensitivity to anticancer therapies. Importantly, small-molecule activators of METTL3, as well as inhibitors of METTL3, FTO, ALKBH5, and IGF2BP1 have recently been identified and have shown considerable anticancer effects when administered alone or in combination with other anticancer agents, both in vitro and in mouse models of human cancers. Future compound screening and design of more potent and selective RNA m6A modification protein inhibitors and activators are expected to provide novel anticancer agents, appropriate for clinical trials in patients with cancer tissues harboring aberrant RNA m6A modification protein expression or RNA m6A modification protein-induced resistance to cancer therapy.

The pan-cancer lncRNA PLANE regulates an alternative splicing program to promote cancer pathogenesis.

Genomic amplification of the distal portion of chromosome 3q, which encodes a number of oncogenic proteins, is one of the most frequent chromosomal abnormalities in malignancy. Here we functionally characterise a non-protein product of the 3q region, the long noncoding RNA (lncRNA) PLANE, which is upregulated in diverse cancer types through copy number gain as well as E2F1-mediated transcriptional activation. PLANE forms an RNA-RNA duplex with the nuclear receptor co-repressor 2 (NCOR2) pre-mRNA at intron 45, binds to heterogeneous ribonucleoprotein M (hnRNPM) and facilitates the association of hnRNPM with the intron, thus leading to repression of the alternative splicing (AS) event generating NCOR2-202, a major protein-coding NCOR2 AS variant. This is, at least in part, responsible for PLANE-mediated promotion of cancer cell proliferation and tumorigenicity. These results uncover the function and regulation of PLANE and suggest that PLANE may constitute a therapeutic target in the pan-cancer context.

Targeted Therapy of TERT-Rearranged Neuroblastoma with BET Bromodomain Inhibitor and Proteasome Inhibitor Combination Therapy.

PURPOSE: TERT gene rearrangement with transcriptional superenhancers leads to TERT overexpression and neuroblastoma. No targeted therapy is available for clinical trials in patients with TERT-rearranged neuroblastoma. EXPERIMENTAL DESIGN: Anticancer agents exerting the best synergistic anticancer effects with BET bromodomain inhibitors were identified by screening an FDA-approved oncology drug library. The synergistic effects of the BET bromodomain inhibitor OTX015 and the proteasome inhibitor carfilzomib were examined by immunoblot and flow cytometry analysis. The anticancer efficacy of OTX015 and carfilzomib combination therapy was investigated in mice xenografted with TERT-rearranged neuroblastoma cell lines or patient-derived xenograft (PDX) tumor cells, and the role of TERT reduction in the anticancer efficacy was examined through rescue experiments in mice. RESULTS: The BET bromodomain protein BRD4 promoted TERT-rearranged neuroblastoma cell proliferation through upregulating TERT expression. Screening of an approved oncology drug library identified the proteasome inhibitor carfilzomib as the agent exerting the best synergistic anticancer effects with BET bromodomain inhibitors including OTX015. OTX015 and carfilzomib synergistically reduced TERT protein expression, induced endoplasmic reticulum stress, and induced TERT-rearranged neuroblastoma cell apoptosis which was blocked by TERT overexpression and endoplasmic reticulum stress antagonists. In mice xenografted with TERT-rearranged neuroblastoma cell lines or PDX tumor cells, OTX015 and carfilzomib synergistically blocked TERT expression, induced tumor cell apoptosis, suppressed tumor progression, and improved mouse survival, which was largely reversed by forced TERT overexpression. CONCLUSIONS: OTX015 and carfilzomib combination therapy is likely to be translated into the first clinical trial of a targeted therapy in patients with TERT-rearranged neuroblastoma.