SRSF2 plays an unexpected role as reader of m5C on mRNA, linking epitranscriptomics to cancer.

A common mRNA modification is 5-methylcytosine (m5C), whose role in gene-transcript processing and cancer remains unclear. Here, we identify serine/arginine-rich splicing factor 2 (SRSF2) as a reader of m5C and impaired SRSF2 m5C binding as a potential contributor to leukemogenesis. Structurally, we identify residues involved in m5C recognition and the impact of the prevalent leukemia-associated mutation SRSF2P95H. We show that SRSF2 binding and m5C colocalize within transcripts. Furthermore, knocking down the m5C writer NSUN2 decreases mRNA m5C, reduces SRSF2 binding, and alters RNA splicing. We also show that the SRSF2P95H mutation impairs the ability of the protein to read m5C-marked mRNA, notably reducing its binding to key leukemia-related transcripts in leukemic cells. In leukemia patients, low NSUN2 expression leads to mRNA m5C hypomethylation and, combined with SRSF2P95H, predicts poor outcomes. Altogether, we highlight an unrecognized mechanistic link between epitranscriptomics and a key oncogenesis driver.

The value of LH maximum level in predicting optimal oocyte yield following GnRH agonist trigger.

Background: Risk factors associated with a suboptimal response to Gonadotropin-releasing hormone (GnRH) agonists include a high or low body mass index (BMI), prolonged use of oral contraceptive pills, and low luteinizing hormone (LH) levels on either the start or trigger days of controlled ovarian stimulation (COS). However, this approach may increase the need for a dual trigger and may also result in a higher incidence of ovarian hyperstimulation syndrome (OHSS) in hyper-responders. We aimed to investigate whether the maximum LH level during stimulation can serve as a predictive factor for achieving an optimal oocyte yield using the GnRH agonist trigger alone. Methods: We retrospectively reviewed all antagonist protocols or progestin-primed ovarian stimulation (PPOS) protocols triggered with GnRH agonist only between May 2012 and December 2022. Subjects were divided into three groups, depending on basal LH level and LH maximum level. The freeze-all strategy was implemented in all cycles: Group 1, consistently low LH levels throughout COS; Group 2, low basal LH level with high LH max level during COS; Group 3, consistently high LH levels throughout COS. The primary outcome was the oocyte yield rate. The secondary outcome includes the number of collected oocytes, suboptimal response to GnRH agonist trigger, oocyte maturity rate, fertilized rate, clinical pregnancy rate, ongoing pregnancy rate, and live birth rate. The pregnancy outcomes were calculated for the first FET cycle. Results: Following confounder adjustment, multivariable regression analysis showed that Group 1 (cycles with consistently low LH levels throughout COS) remains an independent predictor of suboptimal response (OR: 6.99; 95% CI 1.035-47.274). Group 1 (b = -12.72; 95% CI -20.9 to -4.55) and BMI (b = -0.25; 95% CI -0.5 to -0.004) were negatively associated with oocyte yield rate. Patients with low basal LH but high LH max levels had similar clinical outcomes compared to those with high LH max levels through COS. Conclusions: The maximum LH level during COS may serve as an indicator of LH reserve and could be a more reliable predictor of achieving an optimal oocyte yield when compared to relying solely on the basal LH level. In the case of hyper-responders where trigger agents (agonist-only or dual trigger) are being considered, we propose a novel strategy that incorporates the maximum LH level, rather than just the basal or trigger-day LH level, as a reference for assessing LH reserve. This approach aims to minimize the risk of obtaining suboptimal oocyte yield and improve overall treatment outcomes.

Splicing Factor SRSF1 Promotes Pancreatitis and KRASG12D-Mediated Pancreatic Cancer.

Inflammation is strongly associated with pancreatic ductal adenocarcinoma (PDAC), a highly lethal malignancy. Dysregulated RNA splicing factors have been widely reported in tumorigenesis, but their involvement in pancreatitis and PDAC is not well understood. Here, we report that the splicing factor SRSF1 is highly expressed in pancreatitis, PDAC precursor lesions, and tumors. Increased SRSF1 is sufficient to induce pancreatitis and accelerate KRASG12D-mediated PDAC. Mechanistically, SRSF1 activates MAPK signaling-partly by upregulating interleukin 1 receptor type 1 (IL1R1) through alternative-splicing-regulated mRNA stability. Additionally, SRSF1 protein is destabilized through a negative feedback mechanism in phenotypically normal epithelial cells expressing KRASG12D in mouse pancreas and in pancreas organoids acutely expressing KRASG12D, buffering MAPK signaling and maintaining pancreas cell homeostasis. This negative feedback regulation of SRSF1 is overcome by hyperactive MYC, facilitating PDAC tumorigenesis. Our findings implicate SRSF1 in the etiology of pancreatitis and PDAC, and point to SRSF1-misregulated alternative splicing as a potential therapeutic target. SIGNIFICANCE: We describe the regulation of splicing factor SRSF1 expression in the context of pancreas cell identity, plasticity, and inflammation. SRSF1 protein downregulation is involved in a negative feedback cellular response to KRASG12D expression, contributing to pancreas cell homeostasis. Conversely, upregulated SRSF1 promotes pancreatitis and accelerates KRASG12D-mediated tumorigenesis through enhanced IL1 and MAPK signaling. This article is highlighted in the In This Issue feature, p. 1501.

The emergent neurosurgical outcome of spontaneous intracranial hemorrhage in patients with chronic liver disease.

Objectives: The influence of chronic liver disease (CLD) on emergent neurosurgical outcomes in patients with spontaneous intracerebral hemorrhage (ICH) remains unclear. CLD is usually associated with coagulopathy and thrombocytopenia, which contribute to a high rebleeding rate and poor prognosis after surgery. This study aimed to confirm the outcomes of spontaneous intracranial hemorrhage in patients with CLD after emergent neurosurgery. Materials and Methods: We reviewed the medical records of all patients with spontaneous ICH from February 2017 to February 2018 at the Buddhist Tzu Chi Hospital, Hualien, Taiwan. This study was approved by the Review Ethical Committee/Institutional Board Review of Hualien Buddhist Tzu Chi Hospital (IRB111-051-B). Patients with aneurysmal subarachnoid hemorrhage, tumors, arteriovenous malformations, and those younger than 18 years were excluded. Duplicate electrode medical records were also removed. Results: Among the 117 enrolled patients, 29 had CLD and 88 did not. There were no significant differences in essential characteristics, comorbidities, biochemical profile, Glasgow coma scale (GCS) score at admission, or ICH sites. The length of hospital stay (LOS) and length of intensive care unit stay (LOICUS) are significantly longer in the CLD group (LOS: 20.8 vs. 13.5 days, P = 0.012; LOICUS: 11 vs. 5 days, P = 0.007). There was no significant difference in the mortality rate between the groups (31.8% vs. 28.4%, P = 0.655). The Wilcoxon rank-sum test for liver and coagulation profiles between survivors and the deceased revealed significant differences in the international normalized ratio (P = 0.02), including low platelet counts (P = 0.03) between survivors and the deceased. A multivariate analysis of mortality found that every 1 mL increase in ICH at admission increased the mortality rate by 3.9%, and every reduction in GCS at admission increased the mortality rate by 30.7%. In our subgroup analysis, we found that the length of ICU stay and LOS are significantly longer in patients with CLD who underwent emergent neurosurgery: 17.7 ± 9.9 days versus 7.59 ± 6.68 days, P = 0.002, and 27.1 ± 7.3 days versus 16.36 ± 9.08 days, P = 0.003, respectively. Conclusions: From our study's perspective, emergent neurosurgery is encouraged. However, there were more prolonged ICU and hospital stays. The mortality rate of patients with CLD who underwent emergent neurosurgery was not higher than that of patients without CLD.

RBFOX2 modulates a metastatic signature of alternative splicing in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDA) is characterized by aggressive local invasion and metastatic spread, leading to high lethality. Although driver gene mutations during PDA progression are conserved, no specific mutation is correlated with the dissemination of metastases1-3. Here we analysed RNA splicing data of a large cohort of primary and metastatic PDA tumours to identify differentially spliced events that correlate with PDA progression. De novo motif analysis of these events detected enrichment of motifs with high similarity to the RBFOX2 motif. Overexpression of RBFOX2 in a patient-derived xenograft (PDX) metastatic PDA cell line drastically reduced the metastatic potential of these cells in vitro and in vivo, whereas depletion of RBFOX2 in primary pancreatic tumour cell lines increased the metastatic potential of these cells. These findings support the role of RBFOX2 as a potent metastatic suppressor in PDA. RNA-sequencing and splicing analysis of RBFOX2 target genes revealed enrichment of genes in the RHO GTPase pathways, suggesting a role of RBFOX2 splicing activity in cytoskeletal organization and focal adhesion formation. Modulation of RBFOX2-regulated splicing events, such as via myosin phosphatase RHO-interacting protein (MPRIP), is associated with PDA metastases, altered cytoskeletal organization and the induction of focal adhesion formation. Our results implicate the splicing-regulatory function of RBFOX2 as a tumour suppressor in PDA and suggest a therapeutic approach for metastatic PDA.

Gas-phase and PM2.5-bound phthalates in nail salons: characteristics, exposure via inhalation, and influencing factors.

This study aimed to investigate the characteristics of, exposure to, and factors influencing gas-phase and PM2.5-bound phthalates (PAEs) in nail salons. Data on both indoor and outdoor gas-phase and PM2.5-bound PAEs, carbon dioxide (CO2), temperature, and relative humidity were collected in nail salons. We also used questionnaires to survey building characteristics and occupants' behaviors. The average total gas-phase and PM2.5-bound PAE concentrations indoors were higher than those outdoors by 6 and 3 times, respectively. Diethyl phthalate, diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), and di-(2-ethylhexyl) phthalate (DEHP) were the predominant compounds among both the gas-phase and PM2.5-bound PAEs in indoor air. The volume of the salon's space or the difference of indoor and outdoor CO2 concentrations (dCO2) was significantly associated with indoor PAE concentrations. The ratios of PM2.5-bound to gas-phase PAEs, especially high-molecular-weight PAEs, were positively associated with the dCO2 concentrations. Higher ratios of indoor to outdoor PM2.5-bound DiBP, DnBP, and DEHP concentrations were discovered when more clients visited each day. Building characteristics, ventilation conditions, and occupants' activities have influences on the gas-phase and particle-phase PAEs. The study identifies the characteristics of gas-phase and PM2.5-bound PAEs in nail salons and their influencing factors.

ASO-Based PKM Splice-Switching Therapy Inhibits Hepatocellular Carcinoma Growth.

The M2 pyruvate kinase (PKM2) isoform is upregulated in most cancers and plays a crucial role in regulation of the Warburg effect, which is characterized by the preference for aerobic glycolysis over oxidative phosphorylation for energy metabolism. PKM2 is an alternative-splice isoform of the PKM gene and is a potential therapeutic target. Antisense oligonucleotides (ASO) that switch PKM splicing from the cancer-associated PKM2 to the PKM1 isoform have been shown to induce apoptosis in cultured glioblastoma cells when delivered by lipofection. Here, we explore the potential of ASO-based PKM splice switching as a targeted therapy for liver cancer. A more potent lead constrained-ethyl (cEt)/DNA ASO induced PKM splice switching and inhibited the growth of cultured hepatocellular carcinoma (HCC) cells. This PKM isoform switch increased pyruvate-kinase activity and altered glucose metabolism. In an orthotopic HCC xenograft mouse model, the lead ASO and a second ASO targeting a nonoverlapping site inhibited tumor growth. Finally, in a genetic HCC mouse model, a surrogate mouse-specific ASO induced Pkm splice switching and inhibited tumorigenesis, without observable toxicity. These results lay the groundwork for a potential ASO-based splicing therapy for HCC. SIGNIFICANCE: Antisense oligonucleotides are used to induce a change in PKM isoform usage in hepatocellular carcinoma, reversing the Warburg effect and inhibiting tumorigenesis.

Single incision laparoscopic surgery using conventional laparoscopic instruments versus two-port laparoscopic surgery for adnexal lesions.

Single incision laparoscopic surgery (SILS) has emerged as least invasive interventions for gynecologic disease. However, SILS is slow to gain in popularity due to difficulties in triangulation and instrument crowding. Besides, the costly instruments may influence patients' will to have this procedure, and limit other medical expense as well. To optimize outcome and reduce cost, the objective of this study is to evaluate the feasibility and safety for patients undergoing adnexal surgeries using conventional laparoscopic instruments with SILS (SILS-C), and to compare with those of patients subject to TP using conventional laparoscopic instruments (TP-C). This is a retrospective case-control study. The data dated from April 2011 to April 2018. Patients who received concomitant multiple surgeries, were diagnosed with suspected advanced stage ovarian malignancy, or required frozen sections for intraoperative pathologic diagnosis were excluded. Demographic data, including the age, body weight, height, previous abdominal surgery were obtained. The surgical outcomes were compared using conventional statistical methods. 259 patients received SILS-C. The operating time was 63.83 ± 25.31 min. Blood loss was 2.38 ± 6.09 c.c. 58 patients (24.38%) needed addition of port to complete surgery. 384 patients received TP-C. Compared with SILS-C, the operating time was shorter (57.32 ± 26.38 min, OR = 0.984, CI = 0.975-0.992). The patients were further divided into unilateral or bilateral adnexectomy, and unilateral or bilateral cystectomy. Other than the operating time in unilateral cystectomy (66.12 ± 19.5 vs. 58.27 ± 23.92 min, p = .002), no statistical differences were observed in the subgroup analysis. Single incision laparoscopic surgery using conventional laparoscopic instruments is feasible and safe as initial approach to adnexal lesions. In complex setting as unilateral cystectomy or pelvic adhesions, two-port access may be considered.

Association Between Preoperative Blood Glucose Level and Hospital Length of Stay for Patients Undergoing Appendectomy or Laparoscopic Cholecystectomy.

OBJECTIVE: To evaluate the effect of preoperative blood glucose (POBG) level on hospital length of stay (LOS) in patients undergoing appendectomy or laparoscopic cholecystectomy. RESEARCH DESIGN AND METHODS: We conducted a retrospective cohort study of patients aged ≥18 years who had undergone appendectomy or laparoscopic cholecystectomy procedures between 2005 and 2016 at a tertiary medical center in Taiwan. The association between POBG level and LOS was evaluated using a multivariable quasi-Poisson regression with robust variance. Multiple imputations were performed to replace missing values. RESULTS: We included 8,291 patients; 4,025 patients underwent appendectomy (appendectomy group) and 4,266 underwent laparoscopic cholecystectomy (laparoscopic cholecystectomy group). In the appendectomy group, patients with POBG levels of ≥123 mg/dL (adjusted relative risk [aRR] 1.19; 95% CI 1.06-1.33) had a 19% higher risk of having a LOS of >3 days than did those with POBG levels of <106 mg/dL. In the laparoscopic cholecystectomy group, patients with POBG levels of ≥128 mg/dL also had a significantly higher risk of having a LOS of >3 days (aRR 1.17; 95% CI 1.07-1.29) than did those with POBG levels of <102 mg/dL. A positive dose-response curve between POBG and an adjusted risk of a LOS of >3 days was observed, although the curve starts to flatten at a POBG level of ∼130 mg/dL. CONCLUSIONS: We demonstrated that a higher POBG level was significantly associated with a prolonged LOS for patients undergoing appendectomy or laparoscopic cholecystectomy. The optimal POBG level may be lower than that commonly perceived.

Recurrent SRSF2 mutations in MDS affect both splicing and NMD.

Oncogenic mutations in the RNA splicing factors SRSF2, SF3B1, and U2AF1 are the most frequent class of mutations in myelodysplastic syndromes and are also common in clonal hematopoiesis, acute myeloid leukemia, chronic lymphocytic leukemia, and a variety of solid tumors. They cause genome-wide splicing alterations that affect important regulators of hematopoiesis. Several mRNA isoforms promoted by the various splicing factor mutants comprise a premature termination codon (PTC) and are therefore potential targets of nonsense-mediated mRNA decay (NMD). In light of the mechanistic relationship between splicing and NMD, we sought evidence for a specific role of mutant SRSF2 in NMD. We show that SRSF2 Pro95 hot spot mutations elicit enhanced mRNA decay, which is dependent on sequence-specific RNA binding and splicing. SRSF2 mutants enhance the deposition of exon junction complexes (EJCs) downstream from the PTC through RNA-mediated molecular interactions. This architecture then favors the association of key NMD factors to elicit mRNA decay. Gene-specific blocking of EJC deposition by antisense oligonucleotides circumvents aberrant NMD promoted by mutant SRSF2, restoring the expression of PTC-containing transcript. Our study uncovered critical effects of SRSF2 mutants in hematologic malignancies, reflecting the regulation at multiple levels of RNA metabolism, from splicing to decay.

MEK2 is a critical modulating mechanism to down-regulate GCIP stability and function in cancer cells.

Loss of tumor suppressor activity and upregulation of oncogenic pathways simultaneously contribute to tumorigenesis. Expression of the tumor suppressor, GCIP (Grap2- and cyclin D1-interacting protein), is usually reduced or lost in advanced cancers, as seen in both mouse tumor models and human cancer patients. However, no previous study has examined how cancer cells down-regulate GCIP expression. In this study, we first validate the tumor suppressive function of GCIP using clinical gastric cancer tissues and online database analysis. We then reveal a novel mechanism whereby MEK2 directly interacts with and phosphorylates GCIP at its Ser313 and Ser356 residues to promote the turnover of GCIP by ubiquitin-mediated proteasomal degradation. We also reveal that decreased GCIP stability enhances cell proliferation and promotes cancer cell migration and invasion. Taken together, these findings provide a more comprehensive view of GCIP in tumorigenesis and suggest that the oncogenic MEK/ERK signaling pathway negatively regulates the protein level of GCIP to promote cell proliferation and migration.

Bioactivity Evaluation of a Novel Formulated Curcumin.

Curcumin has been used as a traditional medicine and/or functional food in several cultures because of its health benefits including anticancer properties. However, poor oral bioavailability of curcumin has limited its oral usage as a food supplement and medical food. Here we formulated curcumin pellets using a solid dispersion technique. The pellets had the advantages of reduced particle size, improved water solubility, and particle porosity. This pellet form led to an improvement in curcumin's oral bioavailability. Additionally, we used the C-Map and Library of Integrated Network-Based Cellular Signatures (LINCS) Unified Environment (CLUE) gene expression database to determine the potential biological functions of formulated curcumin. The results indicated that, similar to conventional curcumin, the formulated curcumin acted as an NF-κB pathway inhibitor. Moreover, ConsensusPathDB database analysis was used to predict possible targets and it revealed that both forms of curcumin exhibit similar biological functions, including apoptosis. Biochemical characterization revealed that both the forms indeed induced apoptosis of hepatocellular carcinoma (HCC) cell lines. We concluded that the formulated curcumin increases the oral bioavailability in animals, and, as expected, retains characteristics similar to conventional curcumin at the cellular level. Our screening platform using big data not only confirms that both the forms of curcumin have similar mechanisms but also predicts the novel mechanism of the formulated curcumin.

Differential Functions of Splicing Factors in Mammary Transformation and Breast Cancer Metastasis.

Misregulation of alternative splicing is a hallmark of human tumors, yet to what extent and how it contributes to malignancy are only beginning to be unraveled. Here, we define which members of the splicing factor SR and SR-like families contribute to breast cancer and uncover differences and redundancies in their targets and biological functions. We identify splicing factors frequently altered in human breast tumors and assay their oncogenic functions using breast organoid models. We demonstrate that not all splicing factors affect mammary tumorigenesis in MCF-10A cells. Specifically, the upregulation of SRSF4, SRSF6, or TRA2ß disrupts acinar morphogenesis and promotes cell proliferation and invasion in MCF-10A cells. By characterizing the targets of these oncogenic splicing factors, we identify shared spliced isoforms associated with well-established cancer hallmarks. Finally, we demonstrate that TRA2ß is regulated by the MYC oncogene, plays a role in metastasis maintenance in vivo, and its levels correlate with breast cancer patient survival.

In silico identification of thiostrepton as an inhibitor of cancer stem cell growth and an enhancer for chemotherapy in non-small-cell lung cancer.

Cancer stem cells (CSCs) play an important role in cancer treatment resistance and disease progression. Identifying an effective anti-CSC agent may lead to improved disease control. We used CSC-associated gene signatures to identify drug candidates that may inhibit CSC growth by reversing the CSC gene signature. Thiostrepton, a natural cyclic oligopeptide antibiotic, was the top-ranked candidate. In non-small-cell lung cancer (NSCLC) cells, thiostrepton inhibited CSC growth in vitro and reduced protein expression of cancer stemness markers, including CD133, Nanog and Oct4A. In addition, metastasis-associated Src tyrosine kinase signalling, cell migration and epithelial-to-mesenchymal transition (EMT) were all inhibited by thiostrepton. Mechanistically, thiostrepton treatment led to elevated levels of tumour suppressor miR-98. Thiostrepton combined with gemcitabine synergistically suppressed NSCLC cell growth and induced apoptosis. The inhibition of NSCLC tumours and CSC growth by thiostrepton was also demonstrated in vivo. Our findings indicate that thiostrepton, an established drug identified in silico, is an inhibitor of CSC growth and a potential enhancer of chemotherapy in NSCLC.

Coordinated alterations in RNA splicing and epigenetic regulation drive leukaemogenesis.

Transcription and pre-mRNA splicing are key steps in the control of gene expression and mutations in genes regulating each of these processes are common in leukaemia1,2. Despite the frequent overlap of mutations affecting epigenetic regulation and splicing in leukaemia, how these processes influence one another to promote leukaemogenesis is not understood and, to our knowledge, there is no functional evidence that mutations in RNA splicing factors initiate leukaemia. Here, through analyses of transcriptomes from 982 patients with acute myeloid leukaemia, we identified frequent overlap of mutations in IDH2 and SRSF2 that together promote leukaemogenesis through coordinated effects on the epigenome and RNA splicing. Whereas mutations in either IDH2 or SRSF2 imparted distinct splicing changes, co-expression of mutant IDH2 altered the splicing effects of mutant SRSF2 and resulted in more profound splicing changes than either mutation alone. Consistent with this, co-expression of mutant IDH2 and SRSF2 resulted in lethal myelodysplasia with proliferative features in vivo and enhanced self-renewal in a manner not observed with either mutation alone. IDH2 and SRSF2 double-mutant cells exhibited aberrant splicing and reduced expression of INTS3, a member of the integrator complex3, concordant with increased stalling of RNA polymerase II (RNAPII). Aberrant INTS3 splicing contributed to leukaemogenesis in concert with mutant IDH2 and was dependent on mutant SRSF2 binding to cis elements in INTS3 mRNA and increased DNA methylation of INTS3. These data identify a pathogenic crosstalk between altered epigenetic state and splicing in a subset of leukaemias, provide functional evidence that mutations in splicing factors drive myeloid malignancy development, and identify spliceosomal changes as a mediator of IDH2-mutant leukaemogenesis.

Podoplanin, a Potential Therapeutic Target for Nasopharyngeal Carcinoma.

INTRODUCTION: The role of podoplanin (PDPN) in nasopharyngeal carcinoma (NPC) is still unknown. The aims of this study were to investigate the expression and role of PDPN in NPC cells. MATERIALS AND METHODS: Immunofluorescence staining and functional tests were used to determine the effects of PDPN knockdown by siRNA in TW01 NPC cells. Microarray analysis was conducted to identify genes regulated by PDPN. The molecular mechanism of PDPN on NPC cells was further determined by Ingenuity Pathways Analysis (IPA). RESULTS: PDPN was expressed in most TW01 NPC cells. PDPN knockdown by siRNA decreased NPC cell proliferation, migration, and invasion. The microarray data showed 63 upregulated genes and 12 downregulated genes following PDPN knockdown. The top 5 most upregulated genes analyzed by IPA were IFI27, IFI44L, IFI6, OAS1, and TRIM22, and the most relevant pathway was the interferon signaling pathway. CONCLUSIONS: To the best of our knowledge, this is the first report to show that knocking down PDPN leads to suppression of NPC cell proliferation, migration, and invasion. Our results suggest that PDPN may serve as a potential chemotherapeutic target for NPC treatment in the future.

Using the Pleiotropic Characteristics of Curcumin to Validate the Potential Application of a Novel Gene Expression Screening Platform.

Curcumin is a polyphenol derived from curcumin longa that exhibits anticancer and anti-inflammatory properties. The consumption of foods at supernutritional levels to obtain health benefits may paradoxically result in negative health outcomes. In the present study, multiple targeting characteristics of curcumin were analyzed using our gene expression screening system, which utilized the gene expression signatures of curcumin from human hepatocellular carcinoma and colorectal cancer cells to query gene expression databases and effectively identify the molecular actions of curcumin. In agreement with prediction, curcumin inhibited NF-κB and Aurora-A, and induced G2/M arrest and apoptosis. Curcumin-suppressed NF-κB was identified through inhibition of PLCG1, PIK3R1, and MALT1 in the CD4-T-cell-receptor-signaling NF-κB cascade pathway. The results suggest that our novel gene expression screening platform is an effective method of rapidly identifying unknown biological functions and side effects of compounds with potential nutraceutical benefits.

Targeting an RNA-Binding Protein Network in Acute Myeloid Leukemia.

RNA-binding proteins (RBPs) are essential modulators of transcription and translation frequently dysregulated in cancer. We systematically interrogated RBP dependencies in human cancers using a comprehensive CRISPR/Cas9 domain-focused screen targeting RNA-binding domains of 490 classical RBPs. This uncovered a network of physically interacting RBPs upregulated in acute myeloid leukemia (AML) and crucial for maintaining RNA splicing and AML survival. Genetic or pharmacologic targeting of one key member of this network, RBM39, repressed cassette exon inclusion and promoted intron retention within mRNAs encoding HOXA9 targets as well as in other RBPs preferentially required in AML. The effects of RBM39 loss on splicing further resulted in preferential lethality of spliceosomal mutant AML, providing a strategy for treatment of AML bearing RBP splicing mutations.

A human-specific switch of alternatively spliced AFMID isoforms contributes to TP53 mutations and tumor recurrence in hepatocellular carcinoma.

Pre-mRNA splicing can contribute to the switch of cell identity that occurs in carcinogenesis. Here, we analyze a large collection of RNA-seq data sets and report that splicing changes in hepatocyte-specific enzymes, such as AFMID and KHK, are associated with HCC patients' survival and relapse. The switch of AFMID isoforms is an early event in HCC development and is associated with driver mutations in TP53 and ARID1A The switch of AFMID isoforms is human-specific and not detectable in other species, including primates. Finally, we show that overexpression of the full-length AFMID isoform leads to a higher NAD+ level, lower DNA-damage response, and slower cell growth in HepG2 cells. The integrative analysis uncovered a mechanistic link between splicing switches, de novo NAD+ biosynthesis, driver mutations, and HCC recurrence.