NF-YC in glioma cell proliferation and tumor growth and its role as an independent predictor of patient survival

The alternative polyadenylation regulator CFIm25 promotes macrophage differentiation and activates the NF-κB pathway

BACKGROUND

Macrophages are required for development and tissue repair and protect against microbial attacks. In response to external signals, monocytes differentiate into macrophages, but our knowledge of changes that promote this transition at the level of mRNA processing, in particular mRNA polyadenylation, needs advancement if it is to inform new disease treatments. Here, we identify CFIm25, a well-documented regulator of poly(A) site choice, as a novel mediator of macrophage differentiation.

METHODS

CFIm25 expression was analyzed in differentiating primary human monocytes and monocytic cell lines. Overexpression and depletion experiments were performed to assess CFIm25's role in differentiation, NF-κB signaling, and alternative polyadenylation (APA). mRNA 3' end-focused sequencing was conducted to identify changes in poly(A) site use of genes involved in macrophage differentiation and function. Cell cycle markers, NF-κB pathway components, and their targets were examined. The role of CFIm25 in NF-κB signaling was further evaluated through chemical inhibition and knockdown of pathway regulators.

RESULTS

CFIm25 showed a striking increase upon macrophage differentiation, suggesting it promotes this process. Indeed, CFIm25 overexpression during differentiation amplified the acquisition of macrophage characteristics and caused an earlier slowing of the cell cycle, a hallmark of this transition, along with APA-mediated downregulation of cyclin D1. The NF-κB signaling pathway plays a major role in maturation of monocytes to macrophages, and the mRNAs of null, TBL1XR1, and NFKB1, all positive regulators of NF-κB signaling, underwent 3'UTR shortening, coupled with an increase in the corresponding proteins. CFIm25 overexpression also elevated phosphorylation of the NF-κB-p65 transcription activator, produced an earlier increase in the NF-κB targets p21, Bcl-XL, ICAM1 and TNF-α, and resulted in greater resistance to NF-κB chemical inhibition. Knockdown of Tables 2 and TBL1XR1 in CFIm25-overexpressing cells attenuated these effects, reinforcing the mechanistic link between CFIm25-regulated APA and NF-κB activation. Conversely, depletion of CFIm25 hindered differentiation and led to lengthening of NFKB1, TAB2, and TBL1XR1 3' UTRs.

CONCLUSIONS

Our study establishes CFIm25 as a key mediator of macrophage differentiation that operates through a coordinated control of cell cycle progression and NF-κB signaling. This linkage of mRNA processing and immune cell function also expands our understanding of the role of alternative polyadenylation in regulating cell signaling.

MTFR2 accelerates hepatocellular carcinoma mediated by metabolic reprogramming via the Akt signaling pathway

Metabolic reprogramming has recently been identified as a hallmark of malignancies. The shift from oxidative phosphorylation to glycolysis in hepatocellular carcinoma (HCC) meets the demands of rapid cell growth and provides a microenvironment for tumor progression. This study sought to uncover the function and mechanism of MTFR2 in the metabolic reprogramming of HCC. Elevated MTFR2 expression was associated with poor patient prognosis. Downregulation of MTFR2 blocked malignant behaviors, epithelial-to-mesenchymal transition (EMT), and glycolysis in HCC cells. Nuclear transcription factor Y subunit gamma (NFYC) was also associated with poor patient prognosis, and NFYC bound to the promoter of MTFR2 to activate transcription and promote Akt signaling. The repressive effects of NFYC knockdown on EMT and glycolysis in HCC cells were compromised by MTFR2 overexpression, elicited through the activation of the Akt signaling. Knockdown of NFYC slowed the growth and intrahepatic metastasis in vivo, which was reversed by MTFR2 overexpression. In conclusion, our work shows that activation of MTFR2 by the transcription factor NFYC promotes Akt signaling, thereby potentiating metabolic reprogramming in HCC development. Targeting the NFYC/MTFR2/Akt axis may represent a therapeutic strategy for HCC.

The alternative polyadenylation regulator CFIm25 promotes macrophage differentiation and activates the NF-κβ pathway

Macrophages are required for our body's development and tissue repair and protect against microbial attacks. We previously reported a crucial role for regulation of mRNA 3'-end cleavage and polyadenylation (C/P) in monocyte to macrophage differentiation. The CFIm25 subunit of the C/P complex showed a striking increase upon differentiation of monocytes with Phorbol Myristate Acetate, suggesting that it promotes this process. To test this hypothesis, CFIm25 was overexpressed in two different monocytic cell lines, followed by differentiation. Both cell lines showed a significant increase in macrophage characteristics and an earlier slowing of the cell cycle. In contrast, depletion of CFIm25 hindered differentiation. Cell cycle slowing upon CFIm25 overexpression was consistent with a greater decrease in the proliferation markers PCNA and cyclin D1, coupled with increased 3'UTR lengthening of cyclin D1 mRNA. Since choice of other poly(A) sites could be affected by manipulating CFIm25, we identified additional genes with altered use of poly(A) sites during differentiation and examined how this changed upon CFIm25 overexpression. The mRNAs of positive regulators of NF-κB signaling, TAB2 and TBL1XR1, and NFKB1, which encodes the NF-κB p50 precursor, underwent 3'UTR shortening that was associated with increased protein expression compared to the control. Cells overexpressing CFIm25 also showed elevated levels of phosphorylated NF-κB-p65 and the NF-κB targets p21, Bcl-XL, ICAM1 and TNF-α at an earlier time and greater resistance to NF-κB chemical inhibition. In conclusion, our study supports a model in which CFIm25 accelerates the monocyte to macrophage transition by promoting alternative polyadenylation events which lead to activation of the NF-κB pathway.

Expression and function of NF-Y subunits in cancer

NF-Y is a Transcription Factor (TF) targeting the CCAAT box regulatory element. It consists of the NF-YB/NF-YC heterodimer, each containing an Histone Fold Domain (HFD), and the sequence-specific subunit NF-YA. NF-YA expression is associated with cell proliferation and absent in some post-mitotic cells. The review summarizes recent findings impacting on cancer development. The logic of the NF-Y regulome points to pro-growth, oncogenic genes in the cell-cycle, metabolism and transcriptional regulation routes. NF-YA is involved in growth/differentiation decisions upon cell-cycle re-entry after mitosis and it is widely overexpressed in tumors, the HFD subunits in some tumor types or subtypes. Overexpression of NF-Y -mostly NF-YA- is oncogenic and decreases sensitivity to anti-neoplastic drugs. The specific roles of NF-YA and NF-YC isoforms generated by alternative splicing -AS- are discussed, including the prognostic value of their levels, although the specific molecular mechanisms of activity are still to be deciphered.

HMGB1 promotes mitochondrial transfer between hepatocellular carcinoma cells through RHOT1 and RAC1 under hypoxia

Mitochondrial transfer plays an important role in various diseases, and many mitochondrial biological functions can be regulated by HMGB1. To explore the role of mitochondrial transfer in hepatocellular carcinoma (HCC) and its relationship with HMGB1, field emission scanning electron microscopy, immunofluorescence, and flow cytometry were used to detect the mitochondrial transfer between HCC cells. We found that mitochondrial transfer between HCC cells was confirmed using tunnel nanotubes (TNTs). The transfer of mitochondria from the highly invasive HCC cells to the less invasive HCC cells could enhance the migration and invasion ability of the latter. The hypoxic conditions increased the mitochondrial transfer between HCC cells. Then the mechanism was identified using co-immunoprecipitation, luciferase reporter assay, and chromatin immunoprecipitation. We found that RHOT1, a mitochondrial transport protein, promoted mitochondrial transfer and the migration and metastasis of HCC cells during this process. Under hypoxia, HMGB1 further regulated RHOT1 expression by increasing the expression of NFYA and NFYC subunits of the NF-Y complex. RAC1, a protein associated with TNTs formation, promoted mitochondrial transfer and HCC development. Besides, HMGB1 regulated RAC1 aggregation to the cell membrane under hypoxia. Finally, the changes and significance of related molecules in clinical samples of HCC were analyzed using bioinformatics and tissue microarray analyses. We found that HCC patients with high HMGB1, RHOT1, or RAC1 expression exhibited a relatively shorter overall survival period. In conclusion, under hypoxic conditions, HMGB1 promoted mitochondrial transfer and migration and invasion of HCC cells by increasing the expression of mitochondrial transport protein RHOT1 and TNTs formation-related protein RAC1.

The NF-Y splicing signature controls hybrid EMT and ECM-related pathways to promote aggressiveness of colon cancer

Aberrant splicing events are associated with colorectal cancer (CRC) and provide new opportunities for tumor diagnosis and treatment. The expression of the splice variants of NF-YA, the DNA binding subunit of the transcription factor NF-Y, is deregulated in multiple cancer types compared to healthy tissues. NF-YAs and NF-YAl isoforms differ in the transactivation domain, which may result in distinct transcriptional programs. In this study, we demonstrated that the NF-YAl transcript is higher in aggressive mesenchymal CRCs and predicts shorter patients' survival. In 2D and 3D conditions, CRC cells overexpressing NF-YAl (NF-YAl^high) exhibit reduced cell proliferation, rapid single cell amoeboid-like migration, and form irregular spheroids with poor cell-to-cell adhesion. Compared to NF-YAs^high, NF-YAl^high cells show changes in the transcription of genes involved in epithelial-mesenchymal transition, extracellular matrix and cell adhesion. NF-YAl and NF-YAs bind similarly to the promoter of the E-cadherin gene, but oppositely regulate its transcription. The increased metastatic potential of NF-YAl^high cells in vivo was confirmed in zebrafish xenografts. These results suggest that the NF-YAl splice variant could be a new CRC prognostic factor and that splice-switching strategies may reduce metastatic CRC progression.

Evolving Diagnostic and Treatment Strategies for Pediatric CNS Tumors: The Impact of Lipid Metabolism

Pediatric neurological tumors are a heterogeneous group of cancers, many of which carry a poor prognosis and lack a "standard of care" therapy. While they have similar anatomic locations, pediatric neurological tumors harbor specific molecular signatures that distinguish them from adult brain and other neurological cancers. Recent advances through the application of genetics and imaging tools have reshaped the molecular classification and treatment of pediatric neurological tumors, specifically considering the molecular alterations involved. A multidisciplinary effort is ongoing to develop new therapeutic strategies for these tumors, employing innovative and established approaches. Strikingly, there is increasing evidence that lipid metabolism is altered during the development of these types of tumors. Thus, in addition to targeted therapies focusing on classical oncogenes, new treatments are being developed based on a broad spectrum of strategies, ranging from vaccines to viral vectors, and melitherapy. This work reviews the current therapeutic landscape for pediatric brain tumors, considering new emerging treatments and ongoing clinical trials. In addition, the role of lipid metabolism in these neoplasms and its relevance for the development of novel therapies are discussed.

NF-YAl drives EMT in Claudinlow tumours

NF-Y is a trimeric transcription factor whose binding site -the CCAAT box- is enriched in cancer-promoting genes. The regulatory subunit, the sequence-specificity conferring NF-YA, comes in two major isoforms, NF-YA long (NF-YAl) and short (NF-YAs). Extensive expression analysis in epithelial cancers determined two features: widespread overexpression and changes in NF-YAl/NF-YAs ratios (NF-YAr) in tumours with EMT features. We performed wet and in silico experiments to explore the role of the isoforms in breast -BRCA- and gastric -STAD- cancers. We generated clones of two Claudin^low BRCA lines SUM159PT and BT549 ablated of exon-3, thus shifting expression from NF-YAl to NF-YAs. Edited clones show normal growth but reduced migratory capacities in vitro and ability to metastatize in vivo. Using TCGA, including upon deconvolution of scRNA-seq data, we formalize the clinical importance of high NF-YAr, associated to EMT genes and cell populations. We derive a novel, prognostic 158 genes signature common to BRCA and STAD Claudin^low tumours. Finally, we identify splicing factors associated to high NF-YAr, validating RBFOX2 as promoting expression of NF-YAl. These data bring three relevant results: (i) the definition and clinical implications of NF-YAr and the 158 genes signature in Claudin^low tumours; (ii) genetic evidence of 28 amino acids in NF-YAl with EMT-promoting capacity; (iii) the definition of selected splicing factors associated to NF-YA isoforms.

Molecular Pathogenesis of Glioblastoma in Adults and Future Perspectives: A Systematic Review

Glioblastoma (GBM) is the most common and malignant tumour of the central nervous system. Recent appreciation of the heterogeneity amongst these tumours not only changed the WHO classification approach, but also created the need for developing novel and personalised therapies. This systematic review aims to highlight recent advancements in understanding the molecular pathogenesis of the GBM and discuss related novel treatment targets. A systematic search of the literature in the PubMed library was performed following the PRISMA guidelines for molecular pathogenesis and therapeutic advances. Original and meta-analyses studies from the last ten years were reviewed using pre-determined search terms. The results included articles relevant to GBM development focusing on the aberrancy in cell signaling pathways and intracellular events. Theragnostic targets and vaccination to treat GBM were also explored. The molecular pathophysiology of GBM is complex. Our systematic review suggests targeting therapy at the stemness, p53 mediated pathways and immune modulation. Exciting novel immune therapy involving dendritic cell vaccines, B-cell vaccines and viral vectors may be the future of treating GBM.

Control of Expression of Key Cell Cycle Enzymes Drives Cell Line-Specific Functions of CDK7 in Human PDAC Cells

Inhibition of the dual function cell cycle and transcription kinase CDK7 is known to affect the viability of cancer cells, but the mechanisms underlying cell line-specific growth control remain poorly understood. Here, we employed a previously developed, highly specific small molecule inhibitor that non-covalently blocks ATP binding to CDK7 (LDC4297) to study the mechanisms underlying cell line-specific growth using a panel of genetically heterogeneous human pancreatic tumor lines as model system. Although LDC4297 diminished both transcription rates and CDK T-loop phosphorylation in a comparable manner, some PDAC lines displayed significantly higher sensitivity than others. We focused our analyses on two well-responsive lines (Mia-Paca2 and Panc89) that, however, showed significant differences in their viability upon extended exposure to limiting LDC4297 concentrations. Biochemical and RNAseq analysis revealed striking differences in gene expression and cell cycle control. Especially the downregulation of a group of cell cycle control genes, among them CDK1/2 and CDC25A/C, correlated well to the observed viability differences in Panc89 versus Mia-Paca2 cells. A parallel downregulation of regulatory pathways supported the hypothesis of a feedforward programmatic effect of CDK7 inhibitors, eventually causing hypersensitivity of PDAC lines.

ITGB2 as a prognostic indicator and a predictive marker for immunotherapy in gliomas

PURPOSE

Glioma is the most common primary tumor in the brain, accounting for 81% of intracranial malignancies. Nowadays, cancer immunotherapy has become a novel and revolutionary treatment for patients with advanced, highly aggressive tumors. However, to date, there are no effective biomarkers to reflect the response of glioma patients to immunotherapy. In this study, we aimed to assess the clinical predictive value of ITGB2 in patients with glioma.

METHODS

The correlation between ITGB2 expression levels and glioma progression was explored and validated using data from CGGA, TCGA, GEO datasets, and patient samples from our hospital. Univariate and multivariate cox regression models were developed to determine the predictive role of ITGB2 on the prognosis of patients with glioma. The relationship between ITGB2 and immune activation was then analyzed. Finally, we predicted the immunotherapy response in both high and low ITGB2 expression subgroups.

RESULTS

ITGB2 was significantly elevated in gliomas with higher malignancy and predicted poor prognosis. In multivariate analysis, the hazard ratio for ITGB2 expression (low versus high) was 0.71 with 95% CI (0.59-0.85) (P < 0.001). Furthermore, we found that ITGB2 stratified glioma patients into high and low ITGB2 expression subgroups, exhibiting different clinical outcomes and immune activation status. At last, we demonstrated that glioma patients with high ITGB2 expression levels had better immunotherapy response.

CONCLUSIONS

This study demonstrated ITGB2 as a novel predictor for clinical prognosis and response to immunotherapy in gliomas. Assessing expression levels of ITGB2 is a promising method to discover patients that may benefit from immunotherapy.

EXO5-DNA structure and BLM interactions direct DNA resection critical for ATR-dependent replication restart

Stalled DNA replication fork restart after stress as orchestrated by ATR kinase, BLM helicase, and structure-specific nucleases enables replication, cell survival, and genome stability. Here we unveil human exonuclease V (EXO5) as an ATR-regulated DNA structure-specific nuclease and BLM partner for replication fork restart. We find that elevated EXO5 in tumors correlates with increased mutation loads and poor patient survival, suggesting that EXO5 upregulation has oncogenic potential. Structural, mechanistic, and mutational analyses of EXO5 and EXO5-DNA complexes reveal a single-stranded DNA binding channel with an adjacent ATR phosphorylation motif (T88Q89) that regulates EXO5 nuclease activity and BLM binding identified by mass spectrometric analysis. EXO5 phospho-mimetic mutant rescues the restart defect from EXO5 depletion that decreases fork progression, DNA damage repair, and cell survival. EXO5 depletion furthermore rescues survival of FANCA-deficient cells and indicates EXO5 functions epistatically with SMARCAL1 and BLM. Thus, an EXO5 axis connects ATR and BLM in directing replication fork restart.

NF-Y Subunits Overexpression in HNSCC

Simple Summary

Cancer cells have altered gene expression profiles. This is ultimately elicited by altered structure, expression or binding of transcription factors to regulatory regions of genomes. The CCAAT-binding trimer is a pioneer transcription factor involved in the activation of “cancer” genes. We and others have shown that the regulatory NF-YA subunit is overexpressed in epithelial cancers. Here, we examined large datasets of bulk gene expression profiles, as well as single-cell data, in head and neck squamous cell carcinomas by bioinformatic methods. We partitioned tumors according to molecular subtypes, mutations and positivity for HPV. We came to the conclusion that high levels of the histone-like subunits and the “short” NF-YAs isoform are protective in HPV-positive tumors. On the other hand, high levels of the “long” NF-YAl were found in the recently identified aggressive and metastasis-prone cell population undergoing partial epithelial to mesenchymal transition, p-EMT.

Abstract

NF-Y is the CCAAT-binding trimer formed by the histone fold domain (HFD), NF-YB/NF-YC and NF-YA. The CCAAT box is generally prevalent in promoters of “cancer” genes. We reported the overexpression of NF-YA in BRCA, LUAD and LUSC, and of all subunits in HCC. Altered splicing of NF-YA was found in breast and lung cancer. We analyzed RNA-seq datasets of TCGA and cell lines of head and neck squamous cell carcinomas (HNSCC). We partitioned all TCGA data into four subtypes, deconvoluted single-cell RNA-seq of tumors and derived survival curves. The CCAAT box was enriched in the promoters of overexpressed genes. The “short” NF-YAs was overexpressed in all subtypes and the “long” NF-YAl in Mesenchymal. The HFD subunits are overexpressed, except Basal (NF-YB) and Atypical (NF-YC); NF-YAl is increased in p53 mutated tumors. In HPV-positive tumors, high levels of NF-YAs, p16 and ΔNp63 correlate with better prognosis. Deconvolution of single cell RNA-seq (scRNA-seq) found a correlation of NF-YAl with Cancer Associated Fibroblasts (CAFs) and p-EMT cells, a population endowed with metastatic potential. We conclude that overexpression of HFD subunits and NF-YAs is protective in HPV-positive tumors; expression of NF-YAl is largely confined to mutp53 tumors and malignant p-EMT cells.

Elevation of CXCL1 indicates poor prognosis and radioresistance by inducing mesenchymal transition in glioblastoma

INTRODUCTION

Glioblastoma (GBM) is identified as a lethal malignant tumor derived from the nervous system. Despite the standard clinical strategy including maximum surgical resection, temozolomide (TMZ) chemotherapy, and radiotherapy, the median survival of GBM patients remains <15 months. Accumulating evidence indicates that rapid-acquired radioresistance is one of the most common reasons for GBM recurrence. Therefore, developing novel therapeutic targets for radioresistant GBM could yield long-term cures.

AIMS

To investigate the functional role of CXCL1 in the acquired radioresistance and identify the molecular pathway correlated to CXCL1.

RESULTS

In this study, we identified that CXCL1 is highly expressed in GBM and the elevation of CXCL1 is involved in radioresistance and poor prognosis in GBM patients. Additionally, silencing CXCL1 attenuated the proliferation and radioresistance of GBM cells. Furthermore, we demonstrated that CXCL1-overexpression induced radioresistance through mesenchymal transition of GBM via the activation of nuclear factor-kappa B (NF-κB) signaling.

CONCLUSION

CXCL1 was highly enriched in GBM and positively correlated with poor prognosis in GBM patients. Additionally, elevated CXCL1 induced radioresistance in GBM through regulation of NF-κB signaling by promoting mesenchymal transition in GBM.

NF-YA Overexpression in Lung Cancer: LUSC

The CCAAT box is recognized by the trimeric transcription factor NF-Y, whose NF-YA subunit is present in two major splicing isoforms, NF-YAl (“long”) and NF-YAs (“short”). Little is known about the expression levels of NF-Y subunits in tumors, and nothing in lung cancer. By interrogating RNA-seq TCGA and GEO datasets, we found that, unlike NF-YB/NF-YC, NF-YAs is overexpressed in lung squamous cell carcinomas (LUSC). The ratio of the two isoforms changes from normal to cancer cells, with NF-YAs becoming predominant in the latter. NF-YA increased expression correlates with common proliferation markers. We partitioned all 501 TCGA LUSC tumors in the four molecular cohorts and verified that NF-YAs is similarly overexpressed. We analyzed global and subtype-specific RNA-seq data and found that CCAAT is the most abundant DNA matrix in promoters of genes overexpressed in all subtypes. Enriched Gene Ontology terms are cell-cycle and signaling. Survival curves indicate a worse clinical outcome for patients with increasing global amounts of NF-YA; same with hazard ratios with very high and, surprisingly, very low NF-YAs/NF-YAl ratios. We then analyzed gene expression in this latter cohort and identified a different, pro-migration signature devoid of CCAAT. We conclude that overexpression of the NF-Y regulatory subunit in LUSC has the scope of increasing CCAAT-dependent, proliferative (NF-YAs^high) or CCAAT-less, pro-migration (NF-YAl^high) genes. The data further reinstate the importance of analysis of single isoforms of TFs involved in tumor development.

Overexpression and alternative splicing of NF-YA in breast cancer

NF-Y is a CCAAT-binding trimeric transcription factor, whose regulome, interactome and oncogenic potential point to direct involvement in cellular transformation. Yet little is known about the levels of NF-Y subunits in tumors. We focused on breast carcinomas, and analyzed RNA-Seq datasets of TCGA and 54 BRCA cell lines at gene and isoforms level. We partitioned all tumors in the four major subclasses. NF-YA, but not histone-fold subunits NF-YB/NF-YC, is globally overexpressed, correlating with the proliferative Ki67 marker and a common set of 840 genes, with cell-cycle, metabolism GO terms. Their promoters are enriched in NF-Y, GC-rich and E2F sites. Surprisingly, there is an isoform switch, with the “short” isoform -NF-YAs- becoming predominant in tumors. E2F genes are also overexpressed in BRCA, but no switch in isoforms is observed. In Basal-like Claudin^low cell lines and tumors, expression of NF-YAl -long- isoform is high, together with 11 typical EMT markers and low levels of basal Keratins. Analysis of Progression-Free-Intervals indicates that tumors with unbalance of NF-YA isoforms ratios have worst clinical outcomes. The data suggest that NF-YA overexpression increases CCAAT-dependent, pro-growth genes in BRCA. NF-YAs is associated with a proliferative signature, but high levels of NF-YAl signal loss of epithelial features, EMT and acquisition of a more aggressive behavior in a subset of Claudin^low Basal-like tumors.

Combined elevation of TRIB2 and MAP3K1 indicates poor prognosis and chemoresistance to temozolomide in glioblastoma

Introduction

Glioblastoma (GBM) is the most lethal primary malignant brain tumor in adults with poor survival due to acquired therapeutic resistance and rapid recurrence. Currently, the standard clinical strategy for glioma includes maximum surgical resection, radiotherapy, and temozolomide (TMZ) chemotherapy; however, the median survival of patients with GBM remains poor despite these comprehensive therapies. Therefore, the identification of new prognostic biomarkers is urgently needed to evaluate the malignancy and long‐term outcome of glioma.

Aims

To further investigate prognostic biomarkers and potential therapeutic targets for GBM.

Results

In this study, we identified tribbles pseudokinase 2 (TRIB2) as one of the genes that is most correlated with pathological classification, radioresistance, and TMZ resistance in glioma. Additionally, the expression of mitogen‐activated protein kinase kinase kinase 1 (MAP3K1) showed a strong correlation with TRIB2. Moreover, a combined increase in TRIB2 and MAP3K1 was observed in GBM and indicated a poor prognosis of patients with glioma. Finally, enriched TRIB2 expression and MAP3K1 expression were shown to be associated with resistance to TMZ and radiotherapy.

Conclusion

Combined elevation of TRIB2 and MAP3K1 could be novel prognostic biomarkers and potential therapeutic targets to evaluate the malignancy and long‐term outcomes of GBM.

The phosphorylatable Ser320 of NF-YA is involved in DNA binding of the NF-Y trimer

Nuclear factor Y (NF-Y) is a transcription factor trimer binding to the functionally important CCAAT box, present in promoters of growth-promoting and cell cycle-regulated genes. The regulatory nuclear factor YA (NF-YA) subunit confers sequence-specificity to the histone-like nuclear factor YB/YC dimer. NF-YA harbors 2 serines-Ser320 and Ser326-shown to be phosphorylated by cyclin-dependent kinase 2. High-throughput proteomics data indicate that they are phosphorylated in vivo. Specifically, Ser320 makes structural contacts with the DNA phosphate backbone; Ser320-P is the major NF-YA phosphorylation isoform following overexpression in HeLa cells, increasing upon mitotic arrest. EMSA with recombinant Ala and Glu mutants confirm a role of Ser320, but not Ser326, in stabilization of DNA binding. Transactivation assays of the CCAAT-dependent MDR1 and RHOB promoters show loss in transcription function for Ser320Glu and Ser320Ala NF-YA mutants. Phylogenetic analysis of NF-YA proteins indicates that Ser320 is indeed evolutionarily conserved. We conclude that phosphorylation of this residue belongs to the core mechanisms of DNA-binding control, possibly driven by the necessity to unfasten binding of or to evict NF-Y from CCAAT sites under specific conditions of growth regulation.-Bernardini, A., Lorenzo, M., Nardini, M., Mantovani, R., Gnesutta, N. The phosphorylatable Ser320 of NF-YA is involved in DNA binding of the NF-Y trimer.

NF-Y in cancer: Impact on cell transformation of a gene essential for proliferation

NF-Y is a ubiquitous heterotrimeric transcription factor with a binding affinity for the CCAAT consensus motif, one of the most common cis-acting element in the promoter and enhancer regions of eukaryote genes in direct (CCAAT) or reverse (ATTGG) orientation. NF-Y consists of three subunits, NF-YA, the regulatory subunit of the trimer, NF-YB, and NF-YC, all required for CCAAT binding. Growing evidence in cells and animal models support the notion that NF-Y, driving transcription of a plethora of cell cycle regulatory genes, is a key player in the regulation of proliferation. Proper control of cellular growth is critical for cancer prevention and uncontrolled proliferation is a hallmark of cancer cells. Indeed, during cell transformation aberrant molecular pathways disrupt mechanisms controlling proliferation and many growth regulatory genes are altered in tumors. Here, we review bioinformatics, molecular and functional evidence indicating the involvement of the cell cycle regulator NF-Y in cancer-associated pathways. This article is part of a Special Issue entitled: Nuclear Factor Y in Development and Disease, edited by Prof. Roberto Mantovani.