Fatty Acid Synthase induced S6Kinase facilitates USP11-eIF4B complex formation for sustained oncogenic translation in DLBCL

Targeting ZDHHC21/FASN axis for the treatment of diffuse large B-cell lymphoma

S-palmitoylation is essential for cancer development via regulating protein stability, function and subcellular location, yet the roles S-palmitoylation plays in diffuse large B-cell lymphoma (DLBCL) progression remain enigmatic. In this study, we uncovered a novel function of the palmitoyltransferase ZDHHC21 as a tumor suppressor in DLBCL and identified ZDHHC21 as a key regulator of fatty acid synthetase (FASN) S-palmitoylation for the first time. Specifically, ZDHHC21 was downregulated in DLBCL, and its expression level was associated with the clinical prognosis of patients with DLBCL. In vitro and in vivo experiments suggested that ZDHHC21 suppressed DLBCL cell proliferation. Mechanistically, ZDHHC21 interacted with FASN and mediated its palmitoylation at Cys1317, resulting in a decrease in FASN protein stability and fatty acid synthesis, consequently leading to the inhibition of DLBCL cell growth. Of note, an FDA-approved small-molecule compound lanatoside C interacted with ZDHHC21, increased ZDHHC21 protein stability and decreased FASN expression, which contributed to the suppression of DLBCL growth in vitro and in vivo. Our results demonstrate that ZDHHC21 strongly represses DLBCL cell proliferation by mediating FASN palmitoylation, and suggest that targeting ZDHHC21/FASN axis is a potential therapeutic strategy against DLBCL.

RNA helicase EIF4A1-mediated translation is essential for the GC response

EIF4A1 and cofactors EIF4B and EIF4H have been well characterised in cancers, including B cell malignancies, for their ability to promote the translation of oncogenes with structured 5' untranslated regions. However, very little is known of their roles in nonmalignant cells. Using mouse models to delete Eif4a1, Eif4b or Eif4h in B cells, we show that EIF4A1, but not EIF4B or EIF4H, is essential for B cell development and the germinal centre response. After B cell activation in vitro, EIF4A1 facilitates an increased rate of protein synthesis, MYC expression, and expression of cell cycle regulators. However, EIF4A1-deficient cells remain viable, whereas inhibition of EIF4A1 and EIF4A2 by Hippuristanol treatment induces cell death.

A novel lipid metabolism-based risk model associated with immunosuppressive mechanisms in diffuse large B-cell lymphoma

BACKGROUND

The molecular diversity exhibited by diffuse large B-cell lymphoma (DLBCL) is a significant obstacle facing current precision therapies. However, scoring using the International Prognostic Index (IPI) is inadequate when fully predicting the development of DLBCL. Reprogramming lipid metabolism is crucial for DLBCL carcinogenesis and expansion, while a predictive approach derived from lipid metabolism-associated genes (LMAGs) has not yet been recognized for DLBCL.

METHODS

Gene expression profiles of DLBCL were generated using the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. The LASSO Cox regression was used to construct an effective predictive risk-scoring model for DLBCL patients. The Kaplan-Meier survival assessment was employed to compare a given risk score with the IPI score and its impact on the survival of DLBCL patients. Functional enrichment examination was performed utilizing the KEGG pathway. After identifying hub genes via single-sample GSEA (ssGSEA), immunohistochemical staining and immunofluorescence were performed on lymph node samples from control and DLBCL patients to confirm these identified genes.

RESULTS

Sixteen lipid metabolism- and survival-associated genes were identified to construct a prognostic risk-scoring approach. This model demonstrated robust performance over various datasets and emerged as an autonomous risk factor for predicting the development of DLBCL patients. The risk score could significantly distinguish the development of DLBCL patients from the low-risk and elevated-risk IPI classes. Results from the inhibitory immune-related pathways and lower immune scores suggested an immunosuppressive phenotype within the elevated-risk group. Three hub genes, MECR, ARSK, and RAN, were identified to be negatively correlated with activated CD8 T cells and natural killer T cells in the elevated-risk score class. Ultimately, it was determined that these three genes were expressed by lymphoma cells but not by T cells in clinical samples from DLBCL patients.

CONCLUSION

The risk level model derived from 16 lipid metabolism-associated genes represents a prognostic biomarker for DLBCL that is novel, robust, and may have an immunosuppressive role. It can compensate for the limitations of the IPI score in predicting overall survival and has potential clinical application value.

USP11 promotes glycolysis by regulating HIF-1α stability in hepatocellular carcinoma

Understanding the mechanisms underlying metastasis in hepatocellular carcinoma (HCC) is crucial for developing new therapies against this fatal disease. Deubiquitinase ubiquitin-specific protease 11 (USP11) belongs to the deubiquitinating family and has previously been reported to play a critical role in cancer pathogenesis. Although it has been established that USP11 can facilitate the metastasis and proliferation ability of HCC, the underlying regulatory mechanisms are poorly understood. The primary objective of this research was to reveal hitherto undocumented functions of USP11 during HCC progression, especially those related to metabolism. Under hypoxic conditions, USP11 was found to significantly impact the glycolysis of HCC cells, as demonstrated through various techniques, including RNA-Seq, migration and colony formation assays, EdU and co-immunoprecipitation. Interestingly, we found that USP11 interacted with the HIF-1α complex and maintained HIF-1α protein stability by removing ubiquitin. Moreover, USP11/HIF-1α could promote glycolysis through the PDK1 and LDHA pathways. In general, our results demonstrate that USP11 promotes HCC proliferation and metastasis through HIF-1α/LDHA-induced glycolysis, providing new insights and the experimental basis for developing new treatments for this patient population.

Deubiquitinases in cancer

Ubiquitination is an essential regulator of most, if not all, signalling pathways, and defects in cellular signalling are central to cancer initiation, progression and, eventually, metastasis. The attachment of ubiquitin signals by E3 ubiquitin ligases is directly opposed by the action of approximately 100 deubiquitinating enzymes (DUBs) in humans. Together, DUBs and E3 ligases coordinate ubiquitin signalling by providing selectivity for different substrates and/or ubiquitin signals. The balance between ubiquitination and deubiquitination is exquisitely controlled to ensure properly coordinated proteostasis and response to cellular stimuli and stressors. Not surprisingly, then, DUBs have been associated with all hallmarks of cancer. These relationships are often complex and multifaceted, highlighted by the implication of multiple DUBs in certain hallmarks and by the impact of individual DUBs on multiple cancer-associated pathways, sometimes with contrasting cancer-promoting and cancer-inhibiting activities, depending on context and tumour type. Although it is still understudied, the ever-growing knowledge of DUB function in cancer physiology will eventually identify DUBs that warrant specific inhibition or activation, both of which are now feasible. An integrated appreciation of the physiological consequences of DUB modulation in relevant cancer models will eventually lead to the identification of patient populations that will most likely benefit from DUB-targeted therapies.

Deubiquitylating Enzymes in Cancer and Immunity

Deubiquitylating enzymes (DUBs) maintain relative homeostasis of the cellular ubiquitome by removing the post-translational modification ubiquitin moiety from substrates. Numerous DUBs have been demonstrated specificity for cleaving a certain type of ubiquitin linkage or positions within ubiquitin chains. Moreover, several DUBs perform functions through specific protein-protein interactions in a catalytically independent manner, which further expands the versatility and complexity of DUBs' functions. Dysregulation of DUBs disrupts the dynamic equilibrium of ubiquitome and causes various diseases, especially cancer and immune disorders. This review summarizes the Janus-faced roles of DUBs in cancer including proteasomal degradation, DNA repair, apoptosis, and tumor metastasis, as well as in immunity involving innate immune receptor signaling and inflammatory and autoimmune disorders. The prospects and challenges for the clinical development of DUB inhibitors are further discussed. The review provides a comprehensive understanding of the multi-faced roles of DUBs in cancer and immunity.

Mechanisms of ferroptosis and targeted therapeutic approaches in lymphoma

Lymphoma is the sixth most common type of cancer worldwide. Under the current treatment standards, patients with lymphoma often fail to respond to treatment or relapse early and require further therapy. Hence, novel therapeutic strategies need to be explored and our understanding of the molecular underpinnings of lymphomas should be expanded. Ferroptosis, a non-apoptotic regulated cell death, is characterized by increased reactive oxygen species and lipid peroxidation due to metabolic dysfunction. Excessive or lack of ferroptosis has been implicated in tumor development. Current preclinical evidences suggest that ferroptosis participates in tumorigenesis, progression, and drug resistance of lymphoma, identifying a potential biomarker and an attractive molecular target. Our review summarizes the core mechanisms and regulatory networks of ferroptosis and discusses existing evidences of ferroptosis induction for the treatment of lymphoma, with intent to provide a framework for understanding the role of ferroptosis in lymphomagenesis and a new perspective of lymphoma treatment.

Dual PI3K/HDAC Inhibitor BEBT-908 Exhibits Potent Efficacy as Monotherapy for Primary Central Nervous System Lymphoma

BACKGROUND

The efficacy of systemic treatment for primary central nervous system lymphoma (PCNSL) is limited because of the blood-brain barrier (BBB) and the ineffectiveness of chemotherapy. The dual PI3K/HDAC inhibitor BEBT-908 has exhibited favorable in vivo distribution and activity in various cancers.

OBJECTIVES

The aims of this study were to assess the efficacy of BEBT-908 in brain orthotopic mouse models of hematological malignancies, to investigate its pharmacologic properties, and to elucidate the underlying mechanism of action.

METHODS

We evaluated the anticancer activity of BEBT-908 in various hematological malignancies through cell viability assays. The impact of BEBT-908 on c-Myc expression and ferroptosis signaling pathways was assessed using Western blotting, qPCR, ROS detection, GSH/GSSG detection, and IHC. Pharmacokinetic and pharmacodynamic profiles were assessed through LC-MS/MS and Western blotting. The effects of BEBT-908 in vivo were examined using xenografts and brain orthotopic mouse models.

RESULTS

Our findings demonstrate that BEBT-908 exhibits promising anti-tumor activity in vitro and in vivo across multiple subtypes of hematological malignancies. Furthermore, BEBT-908 exhibits excellent BBB penetration and inhibits tumor growth in a brain orthotopic lymphoma model with prolonged survival of host mice. Mechanistically, BEBT-908 downregulated c-Myc expression, which contributed to ferroptosis, ultimately leading to tumor shrinkage.

CONCLUSION

Our study provides robust evidence for the dual PI3K/HDAC inhibitor BEBT-908 as an effective anti-cancer agent for PCNSL.

Ubiquitin-specific protease 11 structure in complex with an engineered substrate mimetic reveals a molecular feature for deubiquitination selectivity

Ubiquitin-specific proteases (USPs) are crucial for controlling cellular proteostasis and signaling pathways but how deubiquitination is selective remains poorly understood, in particular between paralogues. Here, we developed a fusion tag method by mining the Protein Data Bank and trapped USP11, a key regulator of DNA double-strand break repair, in complex with a novel engineered substrate mimetic. Together, this enabled structure determination of USP11 as a Michaelis-like complex that revealed key S1 and S1' binding site interactions with a substrate. Combined mutational, enzymatic, and binding experiments identified Met77 in linear diubiquitin as a significant residue that leads to substrate discrimination. We identified an aspartate "gatekeeper" residue in the S1' site of USP11 as a contributing feature for discriminating against linear diubiquitin. When mutated to a glycine, the corresponding residue in paralog USP15, USP11 acquired elevated activity toward linear diubiquitin in-gel shift assays, but not controls. The reverse mutation in USP15 confirmed that this position confers paralog-specific differences impacting diubiquitin cleavage rates. The results advance our understanding of the molecular basis for the higher selectivity of USP11 compared to USP15 and may aid targeted inhibitor development. Moreover, the reported carrier-based crystallization strategy may be applicable to other challenging targets.

Targeting YTHDF2 inhibits tumorigenesis of diffuse large B-cell lymphoma through ACER2-mediated ceramide catabolism

INTRODUCTION

Epigenetic alterations play crucial roles in diffuse large B-cell lymphoma (DLBCL). Disturbances in lipid metabolism contribute to tumor progression. However, studies in epigenetics, especially its critical regulator YTH N6-methyladenosine RNA binding protein 2 (YTHDF2), on lipid metabolism regulation in DLBCL are unidentified.

OBJECTIVES

Elucidate the prognostic value and biological functions of YTHDF2 in DLBCL and illuminate the underlying epigenetic regulation mechanism of lipid metabolism by YTHDF2 in DLBCL development.

METHODS

The expression and clinical value of YTHDF2 in DLBCL were performed in public databases and clinical specimens. The biological functions of YTHDF2 in DLBCL were determined in vivo and in vitro through overexpression and CRISPR/Cas9-mediated knockout of YTHDF2. RNA sequencing, lipidomics, methylated RNA immunoprecipitation sequencing, RNA immunoprecipitation-qPCR, luciferase activity assay, and RNA stability experiments were used to explore the potential mechanism by which YTHDF2 contributed to DLBCL progression.

RESULTS

YTHDF2 was highly expressed in DLBCL, and related to poor prognosis. YTHDF2 overexpression exerted a tumor-promoting effect in DLBCL, and knockdown of YTHDF2 restricted DLBCL cell proliferation, arrested cell cycle in the G2/M phase, facilitated apoptosis, and enhanced drug sensitivity to ibrutinib and venetoclax. In addition, YTHDF2 knockout drastically suppressed tumor growth in xenograft DLBCL models. Furthermore, a regulatory role of YTHDF2 in ceramide metabolism was identified in DLBCL cells. Exogenous ceramide effectively inhibited the malignant phenotype of DLBCL cells in vitro. The binding of YTHDF2 to m6A sites on alkaline ceramidase 2 (ACER2) mRNA promoted its stability and expression. Enhanced ACER2 expression hydrolyzed ceramides, disrupting the balance between ceramide and sphingosine-1-phosphate (S1P), activating the ERK and PI3K/AKT pathways, and leading to DLBCL tumorigenesis.

CONCLUSION

This study demonstrated that YTHDF2 contributed to the progression of DLBCL by regulating ACER2-mediated ceramide metabolism in an m6A-dependent manner, providing novel insights into targeted therapies.

Role of EGFR and FASN in breast cancer progression

Breast cancer (BC) emerged as one of the life-threatening diseases among females. Despite notable improvements made in cancer detection and treatment worldwide, according to GLOBACAN 2020, BC is the fifth leading cancer, with an estimated 1 in 6 cancer deaths, in a majority of countries. However, the exact cause that leads to BC progression still needs to be determined. Here, we reviewed the role of two novel biomarkers responsible for 50-70% of BC progression. The first one is epidermal growth factor receptor (EGFR) which belongs to the ErbB tyrosine kinases family, signalling pathways associated with it play a significant role in regulating cell proliferation and division. Another one is fatty acid synthase (FASN), a key enzyme responsible for the de novo lipid synthesis required for cancer cell development. This review presents a rationale for the EGFR-mediated pathways, their interaction with FASN, communion of these two biomarkers with BC, and improvements to overcome drug resistance caused by them.

Disturbed Plasma Lipidomic Profiles in Females with Diffuse Large B-Cell Lymphoma: A Pilot Study

Lipidome dysregulation is a hallmark of cancer and inflammation. The global plasma lipidome and sub-lipidome of inflammatory pathways have not been reported in diffuse large B-cell lymphoma (DLBCL). In a pilot study of plasma lipid variation in female DLBCL patients and BMI-matched disease-free controls, we performed targeted lipidomics using LC-MRM to quantify lipid mediators of inflammation and immunity, and those known or hypothesised to be involved in cancer progression: sphingolipids, resolvin D1, arachidonic acid (AA)-derived oxylipins, such as hydroxyeicosatetraenoic acids (HETEs) and dihydroxyeicosatrienoic acids, along with their membrane structural precursors. We report on the role of the eicosanoids in the separation of DLBCL from controls, along with lysophosphatidylinositol LPI 20:4, implying notable changes in lipid metabolic and/or signalling pathways, particularly pertaining to AA lipoxygenase pathway and glycerophospholipid remodelling in the cell membrane. We suggest here the set of S1P, SM 36:1, SM 34:1 and PI 34:1 as DLBCL lipid signatures which could serve as a basis for the prospective validation in larger DLBCL cohorts. Additionally, untargeted lipidomics indicates a substantial change in the overall lipid metabolism in DLBCL. The plasma lipid profiling of DLBCL patients helps to better understand the specific lipid dysregulations and pathways in this cancer.

FOXP1-GINS1 axis promotes DLBCL proliferation and directs doxorubicin resistance

GINS1 is overexpressed in several types of cancers including leukemia and linked to poor outcomes. However, GINS1 remains poorly investigated in DLBCL (diffuse large B-cell lymphoma). This project aimed to explore the expression, functions and regulation of GINS1 in DLBCL. In this study, through analysis of clinical specimens from DLBCL patients, we uncovered that GINS1 was upregulated in DLBCL. By EMSA, ChIP and luciferase reporter assays, it was found that FOXP1 transcriptionally activated GINS1 expression by directly binding to the promoter region of the GINS1 gene. Western blotting and RT-PCR also revealed that GINS1 expression positively correlated with FOXP1 in human DLBCL specimens and cell lines. In an in vivo xenograft lymphoma mouse model, the FOXP1/GINS1 regulatory axis was also validated. Moreover, with CCK8 cell proliferation assays and colony formation assay, elevated GINS1 expression was found to be associated with doxorubicin resistance in lymphoma cells. Our findings showed that the FOXP1-GINS1 axis played a critical role in DLBCL development and doxorubicin resistance, and targeting the FOXP1-GINS1 axis could be a potential therapeutic approach for DLBCL treatment.

Metabolic Reprogramming and Potential Therapeutic Targets in Lymphoma

Lymphoma is a heterogeneous group of diseases that often require their metabolism program to fulfill the demand of cell proliferation. Features of metabolism in lymphoma cells include high glucose uptake, deregulated expression of enzymes related to glycolysis, dual capacity for glycolytic and oxidative metabolism, elevated glutamine metabolism, and fatty acid synthesis. These aberrant metabolic changes lead to tumorigenesis, disease progression, and resistance to lymphoma chemotherapy. This metabolic reprogramming, including glucose, nucleic acid, fatty acid, and amino acid metabolism, is a dynamic process caused not only by genetic and epigenetic changes, but also by changes in the microenvironment affected by viral infections. Notably, some critical metabolic enzymes and metabolites may play vital roles in lymphomagenesis and progression. Recent studies have uncovered that metabolic pathways might have clinical impacts on the diagnosis, characterization, and treatment of lymphoma subtypes. However, determining the clinical relevance of biomarkers and therapeutic targets related to lymphoma metabolism is still challenging. In this review, we systematically summarize current studies on metabolism reprogramming in lymphoma, and we mainly focus on disorders of glucose, amino acids, and lipid metabolisms, as well as dysregulation of molecules in metabolic pathways, oncometabolites, and potential metabolic biomarkers. We then discuss strategies directly or indirectly for those potential therapeutic targets. Finally, we prospect the future directions of lymphoma treatment on metabolic reprogramming.

PIMT regulates hepatic gluconeogenesis in mice

The physiological and metabolic functions of PIMT/TGS1, a third-generation transcriptional apparatus protein, in glucose homeostasis sustenance are unclear. Here, we observed that the expression of PIMT was upregulated in the livers of short-term fasted and obese mice. Lentiviruses expressing Tgs1-specific shRNA or cDNA were injected into wild-type mice. Gene expression, hepatic glucose output, glucose tolerance, and insulin sensitivity were evaluated in mice and primary hepatocytes. Genetic modulation of PIMT exerted a direct positive impact on the gluconeogenic gene expression program and hepatic glucose output. Molecular studies utilizing cultured cells, in vivo models, genetic manipulation, and PKA pharmacological inhibition establish that PKA regulates PIMT at post-transcriptional/translational and post-translational levels. PKA enhanced 3'UTR-mediated translation of TGS1 mRNA and phosphorylated PIMT at Ser656, increasing Ep300-mediated gluconeogenic transcriptional activity. The PKA-PIMT-Ep300 signaling module and associated PIMT regulation may serve as a key driver of gluconeogenesis, positioning PIMT as a critical hepatic glucose sensor.

Prognostic and therapeutic value of serum lipids and a new IPI score system based on apolipoprotein A-I in diffuse large B-cell lymphoma

Lipid metabolism is associated with lymphomagenesis and functions as a new therapeutic target in patients with lymphoma. Several serum lipids and lipoproteins have prognostic value in solid tumors; however, their value in diffuse large B-cell lymphoma (DLBCL) has been poorly described. We retrospectively analyzed and compared pre-treatment serum lipid and lipoprotein levels, including triacylglycerol (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein A-I (ApoA-I), and apolipoprotein B (ApoB) between 105 DLBCL and 105 controls (no DLBCL). The prognostic significance of serum lipid and lipoprotein levels was determined using univariate and multivariate Cox proportional hazards models. The primary outcomes, overall survival (OS) and progression-free survival (PFS), were assessed by the Kaplan-Meier method. We combined the International Prognostic Index (IPI) with ApoA-I to build a nomogram model (IPI-A) to predict the OS and PFS of DLBCL. Serum TG, LDL-C, HDL-C, ApoA-I, and ApoB levels were significantly lower in the DLBCL patients than in controls and significantly increased after chemotherapy. Multivariate analyses showed that the ApoA-I level was an independent predictor of OS and PFS. In addition, our findings indicated that the prognostic index IPI-A significantly improves risk prediction over the traditional IPI score system. ApoA-I is an independent prognostic factor associated with poor OS and PFS in DLBCL patients. Our findings suggested that IPI-A is a prognostic index accurately used for risk assessment in patients with DLBCL.

Oncogenic deubiquitination controls tyrosine kinase signaling and therapy response in acute lymphoblastic leukemia

Dysregulation of kinase signaling pathways favors tumor cell survival and therapy resistance in cancer. Here, we reveal a posttranslational regulation of kinase signaling and nuclear receptor activity via deubiquitination in T cell acute lymphoblastic leukemia (T-ALL). We observed that the ubiquitin-specific protease 11 (USP11) is highly expressed and associates with poor prognosis in T-ALL. USP11 ablation inhibits leukemia progression in vivo, sparing normal hematopoiesis. USP11 forms a complex with USP7 to deubiquitinate the oncogenic lymphocyte cell-specific protein-tyrosine kinase (LCK) and enhance its activity. Impairment of LCK activity leads to increased glucocorticoid receptor (GR) expression and glucocorticoids sensitivity. Genetic knockout of USP7 improved the antileukemic efficacy of glucocorticoids in vivo. The transcriptional activation of GR target genes is orchestrated by the deubiquitinase activity and mediated via an increase in enhancer-promoter interaction intensity. Our data unveil how dysregulated deubiquitination controls leukemia survival and drug resistance, suggesting previously unidentified therapeutic combinations toward targeting leukemia.

The equilibrium of tumor suppression: DUBs as active regulators of PTEN

PTEN is among the most commonly lost or mutated tumor suppressor genes in human cancer. PTEN, a bona fide lipid phosphatase that antagonizes the highly oncogenic PI3K-AKT-mTOR pathway, is considered a major dose-dependent tumor suppressor. Although PTEN function can be compromised by genetic mutations in inherited syndromes and cancers, posttranslational modifications of PTEN may also play key roles in the dynamic regulation of its function. Notably, deregulated ubiquitination and deubiquitination lead to detrimental impacts on PTEN levels and subcellular partitioning, promoting tumorigenesis. While PTEN can be targeted by HECT-type E3 ubiquitin ligases for nuclear import and proteasomal degradation, studies have shown that several deubiquitinating enzymes, including HAUSP/USP7, USP10, USP11, USP13, OTUD3 and Ataxin-3, can remove ubiquitin from ubiquitinated PTEN in cancer-specific contexts and thus reverse ubiquitination-mediated PTEN regulation. Researchers continue to reveal the precise molecular mechanisms by which cancer-specific deubiquitinases of PTEN regulate its roles in the pathobiology of cancer, and new methods of pharmacologically for modulating PTEN deubiquitinases are critical areas of investigation for cancer treatment and prevention. Here, we assess the mechanisms and functions of deubiquitination as a recently appreciated mode of PTEN regulation and review the link between deubiquitinases and PTEN reactivation and its implications for therapeutic strategies.

Novel eIF4A1 inhibitors with anti-tumor activity in lymphoma

BACKGROUND

Deregulated translation initiation is implicated extensively in cancer initiation and progression. It is actively pursued as a viable target that circumvents the dependency on oncogenic signaling, a significant factor in current strategies. Eukaryotic translation initiation factor (eIF) 4A plays an essential role in translation initiation by unwinding the secondary structure of messenger RNA (mRNA) upstream of the start codon, enabling active ribosomal recruitment on the downstream genes. Several natural product molecules with similar scaffolds, such as Rocaglamide A (RocA), targeting eIF4A have been reported in the last decade. However, their clinical utilization is still elusive due to several pharmacological limitations. In this study we identified new eIF4A1 inhibitors and their possible mechanisms.

METHODS

In this report, we conducted a pharmacophore-based virtual screen of RocA complexed with eIF4A and a polypurine RNA strand for novel eIF4A inhibitors from commercially available compounds in the MolPort Database. We performed target-based screening and optimization of active pharmacophores. We assessed the effects of novel compounds on biochemical and cell-based assays for efficacy and mechanistic evaluation.

RESULTS

We validated three new potent eIF4A inhibitors, RBF197, RBF 203, and RBF 208, which decreased diffuse large B-cell lymphoma (DLBCL) cell viability. Biochemical and cellular studies, molecular docking, and functional assays revealed that thosenovel compounds clamp eIF4A into mRNA in an ATP-independent manner. Moreover, we found that RBF197 and RBF208 significantly depressed eIF4A-dependent oncogene expression as well as the colony formation capacity of DLBCL. Interestingly, exposure of these compounds to non-malignant cells had only minimal impact on their growth and viability.

CONCLUSIONS

Identified compounds suggest a new strategy for designing novel eIF4A inhibitors.

Reprogramming lipid metabolism as potential strategy for hematological malignancy therapy

Hematological malignancies are one of the most lethal illnesses that seriously threaten human life and health. Lipids are important constituents of various biological membranes and substances for energy storage and cell signaling. Furthermore, lipids are critical in the normal physiological activities of cells. In the process of the lethal transformation of hematological malignancies, lipid metabolism reprogramming meets the material and energy requirements of rapidly proliferating and dividing tumor cells. A large number of studies have shown that dysregulated lipid metabolism, commonly occurs in hematological malignancies, mediating the proliferation, growth, migration, invasion, apoptosis, drug resistance and immune escape of tumor cells. Targeting the lipid metabolism pathway of hematological malignancies has become an effective therapeutic approach. This article reviews the oncogenic mechanisms of lipid metabolism reprogramming in hematological malignancies, including fatty acid, cholesterol and phospholipid metabolism, thereby offering an insight into targeting lipid metabolism in the treatment of hematological malignancies.

Characterization of Fatty Acid Metabolism in Lung Adenocarcinoma

Background: Lung adenocarcinoma (LUAD) is the most common subtype of non-small cell lung cancer. Fatty acid metabolism takes part in malignancy progression. However, the roles fatty acid metabolism plays in LUAD are still unclear.

Methods: The transcriptomic and clinical data of LUAD patients from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases were extracted. ssGSEA, WGCNA, univariable Cox regression, and LASSO Cox regression analyses were performed to identify the fatty acid metabolism-related genes which influenced the overall survival (OS) and build a fatty acid-related risk score (FARS) model. A nomogram was established based on the FARS and other clinicopathological features, and ROC and calibration plots were used to validate the prediction accuracy. The tumor microenvironment (TME) of patients with high and low FARS was compared.

Results: A total of 38 genes were identified to be independently related to the survival outcome and put into a FARS model. High FARS patients exhibited significantly worse OS. The nomogram included the FARS and pathological stage, and the AUC of the nomogram predicting 1-, 2-, 3-, 4-, and 5-year OS was 0.789, 0.807, 0.798, 0.809, and 0.753, respectively. Calibration plots also indicated good accuracy. Moreover, the samples of the high FARS had higher expression of PDL1.

Conclusion: We constructed a FARS model which could accurately predict the survival outcome of the LUAD patients. The genes of the FARS are related to the tumor microenvironment and patients with high FARS can potentially benefit more from anti-PD1/PDL1 immunotherapy. In addition, the mechanisms of the genes in the FARS affecting prognosis are worthy of further research to develop new gene-targeted drugs.

Ubiquitin specific peptidase 11 as a novel therapeutic target for cancer management

Ubiquitination is a critical biological process in post-translational modification of proteins and involves multiple signaling pathways in protein metabolism, apoptosis, DNA damage, cell-cycle progression, and cancer development. Deubiquitinase, a specific enzyme that regulates the ubiquitination process, is also thought to be closely associated with the development and progression of various cancers. In this article, we systematically review the emerging role of the deubiquitinase ubiquitin-specific peptidase 11 (USP11) in many cancer-related pathways. The results show that USP11 promotes or inhibits the progression and chemoresistance of different cancers, including colorectal, breast, ovarian, and hepatocellular carcinomas, via deubiquitinating several critical proteins of cancer-related pathways. We initially summarize the role of USP11 in different cancers and further discuss the possibility of USP11 as a therapeutic strategy.

The Dual Role of USP11 in Cancer

Ubiquitination is one of the most crucial ways of protein degradation and plays an indispensable role in various living activities of cells. The deubiquitinating enzyme (DUB) is the main practitioner of the reversal of ubiquitination. Up till the present moment, nearly 100 DUBs from six families have been confirmed. USP11 is a member of the largest subfamily of cysteine protease DUBs, involving in the regulation of cell cycle, DNA repair, regulating signaling pathways, tumor development, and other important biological behaviors. This review briefly describes the structure and function of USP11 and comprehensively describes its dual role in tumorigenesis and development, as well as its targeted therapy.

The PI3K/AKT/mTOR signaling pathway is aberrantly activated in primary central nervous system lymphoma and correlated with a poor prognosis

Background

Primary central nervous system lymphoma (PCNSL) is a specific subtype of non-Hodgkin lymphoma that is highly invasive and confined to the central nervous system (CNS). The vast majority of PCNSLs are diffuse large B-cell lymphomas (DLBCLs). PCNSL is a highly heterogeneous disease, and its pathogenesis has not yet been fully elucidated. Further studies are needed to guide individualized therapy and improve the prognosis.

Methods

In this study, we detected 1) the expression of p-AKT, p-mTOR, p-S6 and p-4E-BP1 by immunohistochemistry (IHC) and Western blotting, 2) the mRNA expression by real-time qPCR and 3) the deletion of PTEN gene by immunofluorescence in situ hybridization (FISH) in order to investigate the activation status of the PI3K/AKT/mTOR signaling pathway in PCNSL. Samples of reactive hyperplasia lymphnods were used as the control group. The correlations between the clinical characteristics and prognosis of PCNSL patients and the expression of p-AKT, p-mTOR, p-S6 and p-4E-BP1 and the deletion of PTEN were assessed.

Results

The IHC results showed that the positive expression rates of p-AKT, p-mTOR, p-S6 and p-4E-BP1 in PCNSL were significantly higher in the PCNSL group than in the control group (P < 0.05). The relative mRNA expression level of MTOR in PCNSL samples was significantly increased (P = 0.013). Correlation analysis revealed that the expression of p-mTOR was correlated with that of p-AKT, p-S6, p-4E-BP1. PTEN deletion was found in 18.9% of PCNSL samples and was correlated with the expression of p-AKT (P = 0.031). Correlation analysis revealed that the PCNSL relapse rate in the p-mTOR-positive group was 64.5%, significantly higher than that in the negative group (P = 0.001). Kaplan-Meier survival analysis showed inferior progression-free survival (PFS) in the p-mTOR- and p-S6-positive groups (P = 0.002 and 0.009, respectively), and PTEN deletion tended to be related to shorter overall survival (OS) (P = 0.072). Cox regression analysis revealed p-mTOR expression as an independent prognostic factor for a shorter PFS (hazard ratio (HR) =7.849, P = 0.046).

Conclusions

Our results suggest that the PI3K/AKT/mTOR signaling pathway is aberrantly activated in PCNSL and associated with a poor prognosis, which might indicate new therapeutic targets and prognostic factors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09275-z.

PARK2 regulates eIF4B-driven lymphomagenesis

Patients with high-risk diffuse large B-cell lymphoma (DLBCL) have poor outcomes following first-line cyclophosphamide, doxorubicin, vincristine, prednisone, and rituximab (R-CHOP); thus, treatment of this fatal disease remains an area of unmet medical need and requires identification of novel therapeutic approaches. Dysregulation of protein translation initiation has emerged as a common downstream node in several malignancies, including lymphoma. Ubiquitination, a prominent post-translational modification associated with substrate degradation, has recently been shown to be a key modulator of nascent peptide synthesis by limiting several translational initiation factors. While a few deubiquitinases have been identified, the E3-ligase responsible for the critical ubiquitination of these translational initiation factors is still unknown. In this study, using complementary cellular models along with clinical readouts, we establish that PARK2 ubiquitinates eIF4B and consequently regulates overall protein translational activity. The formation of this interaction depends on upstream signaling, which is negatively regulated at the protein level of PARK2. Through biochemical, mutational, and genetic studies, we identified PARK2 as a mTORC1 substrate. mTORC1 phosphorylates PARK2 at Ser127, which blocks its cellular ubiquitination activity, thereby hindering its tumor suppressor effect on eIF4B's stability. This resultant increase of eIF4B protein level helps drive enhanced overall protein translation. These data support a novel paradigm in which PARK2-generated eIF4B ubiquitination serves as an anti-oncogenic intracellular inhibitor of protein translation, attenuated by mTORC1 signaling. Implications: Our data implicates the FASN/mTOR-PARK2-eIF4B axis as a critical driver of enhanced oncogene expression contributing to lymphomagenesis.

Translatome changes in acute myeloid leukemia cells post-exposure to pegcrisantaspase and venetoclax

The clinical outcomes of patients with AML treated with available therapy remains unsatisfactory. We recently reported that the BCL-2 inhibitor, venetoclax, synergized with pegcrisantaspase (PegC) and demonstrated remarkable in vivo efficacy in a preclinical model of AML with complex karyotype. Ven-PegC combination blocks synthesis of proteins in AML cells by inhibiting cap-dependent translation of mRNA. To further explore the impact of Ven-PegC on protein translation, we used polysome profiling and high-throughput RNA-seq to characterize Ven-PegC dependent changes to the translatome. Here we report that the translation of five mRNAs, including two microRNAs, one rRNA, and two mitochondrial genes was altered after exposure to all three treatments (Ven, PegC and Ven-PegC). We focused our translatome validation studies on six additional genes related to translational efficiency that were modified by Ven-PegC. Notably, Ven-PegC treatment increased the RNA translation and protein level of Tribbles homolog 3 (TRIB3), eukaryotic translation initiation factor 3 subunit C (eIF3C), doublesex and mab-3 related transcription factor 1 (DMRT1), salt inducible kinase 1 (SIK1). We validated the observed changes in gene/protein expression in vitro and confirmed our cell line-based studies in the bone marrow of an AML PDX model after Ven-PegC treatment. These results support examining alterations in the translatome post-chemotherapy to offer insight into drug mechanism of action and to inform future therapeutic decisions.

Metabolic Reprogramming of Thyroid Cancer Cells and Crosstalk in Their Microenvironment

Metabolism differs significantly between tumor and normal cells. Metabolic reprogramming in cancer cells and metabolic interplay in the tumor microenvironment (TME) are important for tumor formation and progression. Tumor cells show changes in both catabolism and anabolism. Altered aerobic glycolysis, known as the Warburg effect, is a well-recognized characteristic of tumor cell energy metabolism. Compared with normal cells, tumor cells consume more glucose and glutamine. The enhanced anabolism in tumor cells includes de novo lipid synthesis as well as protein and nucleic acid synthesis. Although these forms of energy supply are uneconomical, they are required for the functioning of cancer cells, including those in thyroid cancer (TC). Increasing attention has recently focused on alterations of the TME. Understanding the metabolic changes governing the intricate relationship between TC cells and the TME may provide novel ideas for the treatment of TC.

USP11 regulates autophagy-dependent ferroptosis after spinal cord ischemia-reperfusion injury by deubiquitinating Beclin 1

Spinal cord ischemia-reperfusion injury (SCIRI) is a serious trauma that can lead to loss of sensory and motor function. Ferroptosis is a new form of regulatory cell death characterized by iron-dependent accumulation of lipid peroxides. Ferroptosis has been studied in various diseases; however, the exact function and molecular mechanism of ferroptosis in SCIRI remain unknown. In this study, we demonstrated that ferroptosis is involved in the pathological mechanism of SCIRI. Inhibition of ferroptosis could promote the recovery of motor function in mice after SCIRI. In addition, we found that ubiquitin-specific protease 11 (USP11) was significantly upregulated in neuronal cells after hypoxia-reoxygenation and in the spinal cord in mice with I/R injury. Knockdown of USP11 in vitro and KO of USP11 in vivo (USP11^-/Y) significantly decreased neuronal cell ferroptosis. In mice, this promotes functional recovery after SCIRI. In contrast, in vitro, USP11 overexpression leads to classic ferroptosis events. Overexpression of USP11 in mice resulted in increased ferroptosis and poor functional recovery after SCIRI. Interestingly, upregulating the expression of USP11 also appeared to increase the production of autophagosomes and to cause substantial autophagic flux, a potential mechanism through which USP11 may enhance ferroptosis. The decreased autophagy markedly weakened the ferroptosis mediated by USP11 and autophagy induction had a synergistic effect with USP11. Importantly, USP11 promotes autophagy activation by stabilizing Beclin 1, thereby leading to ferroptosis. In conclusion, this study shows that ferroptosis is closely associated with SCIRI, and that USP11 plays a key role in regulating ferroptosis and additionally identifies USP11-mediated autophagy-dependent ferroptosis as a promising target for the treatment of SCIRI.

Arginine methylation and ubiquitylation crosstalk controls DNA end-resection and homologous recombination repair

Cross-talk between distinct protein post-translational modifications is critical for an effective DNA damage response. Arginine methylation plays an important role in maintaining genome stability, but how this modification integrates with other enzymatic activities is largely unknown. Here, we identify the deubiquitylating enzyme USP11 as a previously uncharacterised PRMT1 substrate, and demonstrate that the methylation of USP11 promotes DNA end-resection and the repair of DNA double strand breaks (DSB) by homologous recombination (HR), an event that is independent from another USP11-HR activity, the deubiquitylation of PALB2. We also show that PRMT1 is a ubiquitylated protein that it is targeted for deubiquitylation by USP11, which regulates the ability of PRMT1 to bind to and methylate MRE11. Taken together, our findings reveal a specific role for USP11 during the early stages of DSB repair, which is mediated through its ability to regulate the activity of the PRMT1-MRE11 pathway.

The deubiquitinase USP11 is a versatile and conserved regulator of autophagy

Autophagy is a major cellular quality control system responsible for the degradation of proteins and organelles in response to stress and damage to maintain homeostasis. Ubiquitination of autophagy-related proteins or regulatory components is important for the precise control of autophagy pathways. Here, we show that the deubiquitinase ubiquitin-specific protease 11 (USP11) restricts autophagy and that KO of USP11 in mammalian cells results in elevated autophagic flux. We also demonstrate that depletion of the USP11 homolog H34C03.2 in Caenorhabditis elegans triggers hyperactivation of autophagy and protects the animals against human amyloid-β peptide 42 aggregation-induced paralysis. USP11 coprecipitated with autophagy-specific class III phosphatidylinositol 3-kinase complex I and limited its interaction with nuclear receptor-binding factor 2, thus decreasing lipid kinase activity of class III phosphatidylinositol 3-kinase complex I and subsequent recruitment of effectors such as WD-repeat domain phosphoinositide-interacting proteins to the autophagosomal membrane. Accordingly, more WD-repeat domain phosphoinositide-interacting protein 2 puncta accumulated in USP11 KO cells. In addition, USP11 interacts with and stabilizes the serine/threonine kinase mechanistic target of rapamycin, thereby further contributing to the regulation of autophagy induction. Taken together, our data suggested that USP11 impinges on the autophagy pathway at multiple sites and that inhibiting USP11 alleviates symptoms of proteotoxicity, which is a major hallmark of neurodegenerative diseases.

Deficiency of eIF4B Increases Mouse Mortality and Impairs Antiviral Immunity

Eukaryotic translation initiation factor 4B (eIF4B) plays an important role in mRNA translation initiation, cell survival and proliferation in vitro. However, its function in vivo is poorly understood. Here, we identified that eIF4B knockout (KO) in mice led to embryonic lethality, and the embryos displayed severe liver damage. Conditional KO (CKO) of eIF4B in adulthood profoundly increased the mortality of mice, characterized by severe pathological changes in several organs and reduced number of peripheral blood lymphocytes. Strikingly, eIF4B CKO mice were highly susceptible to viral infection with severe pulmonary inflammation. Selective deletion of eIF4B in lung epithelium also markedly promoted replication of influenza A virus (IAV) in the lung of infected animals. Furthermore, we observed that eIF4B deficiency significantly enhanced the expression of several important inflammation-associated factors and chemokines, including serum amyloid A1 (Saa1), Marco, Cxcr1, Ccl6, Ccl8, Ccl20, Cxcl2, Cxcl17 that are implicated in recruitment and activation of neutrophiles and macrophages. Moreover, the eIF4B-deficient mice exhibited impaired natural killer (NK) cell-mediated cytotoxicity during the IAV infection. Collectively, the results reveal that eIF4B is essential for mouse survival and host antiviral responses, and establish previously uncharacterized roles for eIF4B in regulating normal animal development and antiviral immunity in vivo.

Deubiquitinating enzymes (DUBs): Regulation, homeostasis, and oxidative stress response

Ubiquitin signaling is a conserved, widespread, and dynamic process in which protein substrates are rapidly modified by ubiquitin to impact protein activity, localization, or stability. To regulate this process, deubiquitinating enzymes (DUBs) counter the signal induced by ubiquitin conjugases and ligases by removing ubiquitin from these substrates. Many DUBs selectively regulate physiological pathways employing conserved mechanisms of ubiquitin bond cleavage. DUB activity is highly regulated in dynamic environments through protein-protein interaction, posttranslational modification, and relocalization. The largest family of DUBs, cysteine proteases, are also sensitive to regulation by oxidative stress, as reactive oxygen species (ROS) directly modify the catalytic cysteine required for their enzymatic activity. Current research has implicated DUB activity in human diseases, including various cancers and neurodegenerative disorders. Due to their selectivity and functional roles, DUBs have become important targets for therapeutic development to treat these conditions. This review will discuss the main classes of DUBs and their regulatory mechanisms with a particular focus on DUB redox regulation and its physiological impact during oxidative stress.

The E2F1/USP11 positive feedback loop promotes hepatocellular carcinoma metastasis and inhibits autophagy by activating ERK/mTOR pathway

Deubiquitinase ubiquitin-specific protease 11 (USP11), a member of the deubiquitinating family, plays an important but still controversial role in cancer development. Namely, USP11 has been shown to promote the proliferation and metastasis of hepatocellular carcinoma (HCC), but the underlying molecular basis is poorly understood. This study aimed to unravel novel functions of USP11 in HCC, especially those related to autophagy. Here, EdU, migration and colony formation assays, and mouse models showed that USP11 played a crucial role in HCC cell proliferation and metastasis in vitro and in vivo. Results from co-immunoprecipitation and ubiquitination assays demonstrated that USP11 interacted with E2F1 and maintained E2F1 protein stability by removing its ubiquitin. Notably, E2F1 regulated USP11 expression at the transcriptional level. Thus, the E2F1/USP11 formed a positive feedback loop to promote the proliferation and migration of HCC cells. Moreover, E2F1/USP11 inhibited autophagy by regulating ERK/mTOR pathway. In addition, the combination treatment inhibition of USP11 and autophagy enhanced the apoptosis of HCC cells and inhibited the tumor growth in mice more effective than either treatment alone. Taken together, these results indicate that the E2F1/USP11 signal axis promotes HCC proliferation and metastasis and inhibits autophagy, which provides an experimental basis for the treatment of HCC.

Venetoclax and pegcrisantaspase for complex karyotype acute myeloid leukemia

Complex karyotype acute myeloid leukemia (CK-AML) has a dismal outcome with current treatments, underscoring the need for new therapies. Here, we report synergistic anti-leukemic activity of the BCL-2 inhibitor venetoclax (Ven) and the asparaginase formulation Pegylated Crisantaspase (PegC) in CK-AML in vitro and in vivo. Ven-PegC combination inhibited growth of multiple AML cell lines and patient-derived primary CK-AML cells in vitro. In vivo, Ven-PegC showed potent reduction of leukemia burden and improved survival, compared with each agent alone, in a primary patient-derived CK-AML xenograft. Superiority of Ven-PegC, compared to single drugs, and, importantly, the clinically utilized Ven-azacitidine combination, was also demonstrated in vivo in CK-AML. We hypothesized that PegC-mediated plasma glutamine depletion inhibits 4EBP1 phosphorylation, decreases the expression of proteins such as MCL-1, whose translation is cap dependent, synergizing with the BCL-2 inhibitor Ven. Ven-PegC treatment decreased cellular MCL-1 protein levels in vitro by enhancing eIF4E-4EBP1 interaction on the cap-binding complex via glutamine depletion. In vivo, Ven-PegC treatment completely depleted plasma glutamine and asparagine and inhibited mRNA translation and cellular protein synthesis. Since this novel mechanistically-rationalized regimen combines two drugs already in use in acute leukemia treatment, we plan a clinical trial of the Ven-PegC combination in relapsed/refractory CK-AML.

Antileukemic efficacy of a potent artemisinin combined with sorafenib and venetoclax

Artemisinins are active against human leukemia cell lines and have low clinical toxicity in worldwide use as antimalarials. Because multiagent combination regimens are necessary to cure fully evolved leukemias, we sought to leverage our previous finding that artemisinin analogs synergize with kinase inhibitors, including sorafenib (SOR), by identifying additional synergistic antileukemic drugs with low toxicity. Screening of a targeted antineoplastic drug library revealed that B-cell lymphoma 2 (BCL2) inhibitors synergize with artemisinins, and validation assays confirmed that the selective BCL2 inhibitor, venetoclax (VEN), synergized with artemisinin analogs to inhibit growth and induce apoptotic cell death of multiple acute leukemia cell lines in vitro. An oral 3-drug "SAV" regimen (SOR plus the potent artemisinin-derived trioxane diphenylphosphate 838 dimeric analog [ART838] plus VEN) killed leukemia cell lines and primary cells in vitro. Leukemia cells cultured in ART838 had decreased induced myeloid leukemia cell differentiation protein (MCL1) levels and increased levels of DNA damage-inducible transcript 3 (DDIT3; GADD153) messenger RNA and its encoded CCATT/enhancer-binding protein homologous protein (CHOP), a key component of the integrated stress response. Thus, synergy of the SAV combination may involve combined targeting of MCL1 and BCL2 via discrete, tolerable mechanisms, and cellular levels of MCL1 and DDIT3/CHOP may serve as biomarkers for action of artemisinins and SAV. Finally, SAV treatment was tolerable and resulted in deep responses with extended survival in 2 acute myeloid leukemia (AML) cell line xenograft models, both harboring a mixed lineage leukemia gene rearrangement and an FMS-like receptor tyrosine kinase-3 internal tandem duplication, and inhibited growth in 2 AML primagraft models.

Multifaceted control of mRNA translation machinery in cancer

The mRNA translation machinery is tightly regulated through several, at times overlapping, mechanisms that modulate its efficiency and accuracy. Due to their fast rate of growth and metabolism, cancer cells require an excessive amount of mRNA translation and protein synthesis. However, unfavorable conditions, such as hypoxia, amino acid starvation, and oxidative stress, which are abundant in cancer, as well as many anti-cancer treatments inhibit mRNA translation. Cancer cells adapt to the various internal and environmental stresses by employing specialised transcript-specific translation to survive and gain a proliferative advantage. We will highlight the major signaling pathways and mechanisms of translation that regulate the global or mRNA-specific translation in response to the intra- or extra-cellular signals and stresses that are key components in the process of tumourigenesis.

The deubiquitinase USP11 regulates cell proliferation and ferroptotic cell death via stabilization of NRF2 USP11 deubiquitinates and stabilizes NRF2

The transcription factor nuclear factor (erythroid-derived 2)-like 2 (NRF2) plays a key role in cancer progression and is tightly regulated by the proteasome pathway. E3 ligases that mediate NRF2 ubiquitination have been widely reported, but the mechanism of NRF2 deubiquitination remains largely unclear. Here, we identified ubiquitin-specific-processing protease 11 (USP11) in NRF2 complexes and confirmed an interaction between these two proteins. We further found that USP11 deubiquitinates NRF2; this modification stabilizes NRF2. Functionally, USP11 depletion contributes to the suppression of cell proliferation and induction of ferroptotic cell death due to ROS-mediated stress, which can be largely abrogated by overexpression of NRF2. Finally, immunohistochemical staining of USP11 and NRF2 was performed using a lung tissue microarray, which revealed that USP11 is highly expressed in patients with NSCLC and positively correlated with NRF2 expression. Together, USP11 stabilizes NRF2 and is thus an important player in cell proliferation and ferroptosis.

Upregulation of fatty acid synthase in MYC and BCL-2 double-expressor lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common and heterogeneous lymphoid malignancy. The subtype with MYC and BCL-2 double-expressor lymphoma (DEL) was defined by its aggressive nature and poor survival outcome. Therefore, the development of effective therapies for the DEL subtype is imperative. Fatty acid synthase (FASN) activity is associated with altered lipid metabolism and aberrant protein translation in DLBCL. However, the inter-regulation of these key processes is not fully determined in DEL. In the present study, the clinical and biological impact of FASN was investigated in the DEL subtype. Initially, FASN expression levels were analyzed from a patient cohort and the data indicated that the highest FASN expression was noted in DEL tissues compared with that noted in the DLBCL and reactive lymphoid hyperplasia tissues. Patients with DEL with combined high-FASN expression indicated poorer EFS outcomes than the rest of the patients. In vitro data indicated that FASN was overexpressed in SU-DHL-2 and U2932 cells. Silencing FASN decreased cell growth and promoted cell apoptosis by modulating the pERK/BCL-2 signaling pathway. In conclusion, the present study indicated that FASN was overexpressed in DEL and that its expression was associated with poor survival outcomes. Furthermore, the data demonstrated that FASN regulated the biological function via the pERK/BCL-2 signaling pathway. FASN serves a critical role in the progression of DEL and its expression may be associated with the development to a more aggressive phenotype of DLBCL. Therefore, it may be considered a potential therapeutic target for DLBCL.

TRIM32/USP11 Balances ARID1A Stability and the Oncogenic/Tumor-Suppressive Status of Squamous Cell Carcinoma

Squamous cell carcinoma (SCC) is an aggressive epithelial malignancy, yet the molecular mechanisms underlying SCC development are elusive. ARID1A is frequently mutated in various cancer types, but both mutation rates and expression levels of ARID1A are ubiquitously low in SCCs. Here, we reveal that excessive protein degradation mediated by the ubiquitin-proteasome system (UPS) contributes to the loss of ARID1A expression in SCC. We identify that the E3 ligase TRIM32 and the deubiquitinase USP11 play key roles in controlling ARID1A stability. TRIM32 depletion inhibits SCC cell proliferation, metastasis, and chemoresistance by stabilizing ARID1A, while USP11 depletion promotes SCC development by promoting ARID1A degradation. We show that syndecan-2 (SDC2) is the downstream target of both ARID1A and USP11 and that SDC2 depletion abolishes the oncogenic function of ARID1A loss. In summary, our data reveal UPS-mediated protein degradation as a mechanism underlying ARID1A loss and propose an important role for the TRIM32/USP11-ARID1A-SDC2 axis in SCC.

DUBbing Down Translation: The Functional Interaction of Deubiquitinases with the Translational Machinery

Cancer cells revamp the regulatory processes that control translation to induce tumor-specific translational programs that can adapt to a hostile microenvironment as well as withstand anticancer therapeutics. Translational initiation has been established as a common downstream effector of numerous deregulated signaling pathways that together culminate in prooncogenic expression. Other mechanisms, including ribosomal stalling and stress granule assembly, also appear to be rewired in the malignant phenotype. Therefore, better understanding of the underlying perturbations driving oncogenic translation in the transformed state will provide innovative therapeutic opportunities. This review highlights deubiquitinating enzymes that are activated/dysregulated in hematologic malignancies, thereby altering the translational output and contributing to tumorigenesis.

Long non-coding RNA in cervical cancer: From biology to therapeutic opportunity

Genome regions that do not for code for proteins are generally transcribed into long non-coding RNAs. Growing evidence reveals that lncRNAs, defined as transcripts longer than 200 nucleotides, are commonly deregulated in cervical malignancies. New sequencing technologies have revealed a complete picture of the composition of the human transcriptome. LncRNAs perform diverse functions at transcriptional, translation, and post-translational levels through interactions with proteins, RNA and DNA. In the past decade, studies have shown that lncRNAs participate in the pathogenesis of many diseases, including cervical cancer. Hence, illuminating the roles of lncRNA will improve our understanding of cervical cancer. In this work, we summarize the current knowledge on lncRNAs in cervical cancer. We describe the emerging roles of lncRNAs in cervical cancer, particularly in cancer progression, metastasis, treatment resistance, HPV regulation, and metabolic reprogramming. The great promises of lncRNAs as potential biomarkers for cervical cancer diagnosis and prognosis are also discussed. We discuss current technologies used to target lncRNAs and thus control cancers, such as antisense oligonucleotides, CRISPR-Cas9, and exosomes. Overall, we show that lncRNAs hold great potentials as therapeutic agents and innovative biomarkers. Finally, further clinical research is necessary to advance our understanding of the therapeutic value of lncRNAs in cervical cancer.

Fatty acid synthase and adenosine monophosphate-activated protein kinase regulate cell survival and drug sensitivity in diffuse large B-cell lymphoma

Fatty acid synthesis is crucial in supporting the survival and proliferation of multiple forms of cancer. The high metabolic demands of fatty acid synthesis are regulated by the AMP-activated kinase and activity of the fatty acid synthase enzyme. In this study, the roles of these enzymes in diffuse large B-cell lymphoma (DLBCL) were investigated by genetic knock-down and pharmacological activation of AMP-activated kinase by metformin, and selective inhibition of fatty acid synthase using the novel drug Fasnall. We observed distinct heterogeneity and adaptive plasticity of lipid metabolism in a panel of DLBCL cell lines and demonstrate the therapeutic potential of inhibiting fatty acid synthesis in a subset of DLBCL cells. The translational relevance of these in vitro data is supported by the strong correlation between AMP-activated protein kinase expression in primary DLBCL samples and disease relapse. Inhibition of fatty acid synthase with Fasnall may represent a therapeutic option for DLBCL that preferentially subverts to de novo fatty acid synthesis.

Targeted inhibition of mRNA translation initiation factors as a novel therapeutic strategy for mature B-cell neoplasms

Cancer development is frequently associated with dysregulation of mRNA translation to enhance both increased global protein synthesis and translation of specific mRNAs encoding oncoproteins. Thus, targeted inhibition of mRNA translation is viewed as a promising new approach for cancer therapy. In this article we review current progress in investigating dysregulation of mRNA translation initiation in mature B-cell neoplasms, focusing on chronic lymphocytic leukemia, follicular lymphoma and diffuse large B-cell lymphoma. We discuss mechanisms and regulation of mRNA translation, potential pathways by which genetic alterations and the tumor microenvironment alters mRNA translation in malignant B cells, preclinical evaluation of drugs targeted against specific eukaryotic initiation factors and current progress towards clinical development. Overall, inhibition of mRNA translation initiation factors is an exciting and promising area for development of novel targeted anti-tumor drugs.

Long noncoding RNA GMAN promotes hepatocellular carcinoma progression by interacting with eIF4B

Gastric cancer metastasis associated long noncoding RNA (GMAN), a long noncoding RNA, is associated with metastasis in gastric cancer. However, its underlying mechanisms in hepatocellular carcinoma (HCC) are unclear. We found that lncRNA-GMAN was significantly overexpressed in HCC tissues. GMAN expression is associated with vascular invasion, histological grade, tumor, node, metastasis (TNM) stage, short overall survival, and disease-free survival. Knockdown of GMAN induced apoptosis and suppressed invasive and migration potential in vitro and vivo, whereas ectopic GMAN expression produced the opposite effect. We also found that the inhibition of apoptosis, rather than promotion of proliferation, was responsible for GMAN-enhanced cellular viability. Mechanistic analyses indicated that GMAN directly combined with eukaryotic translation initiation factor 4B (eIF4B) and promoted its phosphorylation at serine-422 by preventing eIF4B binding and dephosphorization of the protein phosphatase 2A subunit B. The results demonstrated the stability of p-eIF4B and the elevation of mRNA translation and anti-apoptosis-related protein expression, which further induced proliferation and metastasis of HCC. The current study demonstrates that GMAN regulates the progression of HCC by inhibiting apoptosis and promoting the survival of cancer cells.

Identification of Circulating Serum Multi-MicroRNA Signatures in Human DLBCL Models

There remains a need to identify new sensitive diagnostic and predictive blood-based platforms in lymphoma. We previously discovered a novel circulating microRNA (miRNA) signature in a Smurf2-deficient mouse model that spontaneously develops diffuse large B-cell lymphoma (DLBCL). Herein, we investigated this 10-miRNA signature (miR-15a, let-7c, let-7b, miR-27a, miR-10b, miR-18a, miR-497, miR-130a, miR24, and miR-155) in human lymphoma cell lines, mice engrafted with patient-derived xenografts (PDXs), and DLBCL patient serum samples leveraging systems biology analyses and droplet digital PCR (ddPCR) technology. Overall, 90% of the miRNAs were enriched in PDX DLBCL models and human lymphoma cell lines. Circulating miRNAs from the serum of 86 DLBCL patients were significantly increased compared with healthy controls and had similar patterns to the murine models. Strikingly, miRNAs were identified up to 27-fold higher levels in the serum of PDX-bearing mice and human patients compared with lymphoma cell lysates, suggesting a concentration of these factors over time within sera. Using cut-points from recursive partitioning analysis, we derived a 5-miRNA signature (let-7b, let-7c, miR-18a, miR-24, and miR-15a) with a classification rate of 91% for serum from patients with DLBCL versus normal controls. In addition, higher levels of circulating let-7b miRNA were associated with more advanced stage disease (i.e., III-IV vs. I-II) in DLBCL patients and higher levels of miR-27a and miR-24 were associated with MYC rearrangement. Taken together, circulating multi-miRNAs were readily detectable in pre-clinical cell line and human lymphoma models as well as in DLBCL patients where they appeared to distinguish clinico-pathologic subtypes and disease features.

The role of deubiquitinating enzymes in gastric cancer

The epigenetic regulation of gene expression (via DNA methylation, histone modification and microRNA interference) contributes to a variety of diseases, particularly cancer. Protein deubiquitination serves a key role in the mechanism underlying histone modification, and consequently influences tumor development and progression. Improved characterization of the role of ubiquitinating enzymes has led to the identification of numerous deubiquitinating enzymes (DUBs) with various functions. Gastric cancer (GC) is a highly prevalent cancer type that exhibits a high mortality rate. Latest analysis about cancer patient revealed that GC is sixth deadliest cancer type, which frequently occur in male (7.2%) than female (4.1%). Complex associations between DUBs and GC progression have been revealed in multiple studies; however, the molecular mechanism underpinning the metastasis and recurrence of GC is yet to be elucidated. Generally, DUBs were upregulated in gastric cancer. The relation of DUBs and tumor size, classification and staging was observed in GC. Besides, 5-yar survival rate of patients with GC is effeccted by expression level of DUBs. Among the highly expressed DUBs, specifically six DUBs namely UCHs, USPs, OTUs, MJDs, JAMMs and MCPIPs effect on this survival rate. Consequently, the association between GC and DUBs has received increasing attention in recent years. Therefore, in the present review, literature investigating the association between DUBs and GC pathophysiology was analyzed and critically appraised.