PES1 is transcriptionally regulated by BRD4 and promotes cell proliferation and glycolysis in hepatocellular carcinoma

Fructose-1,6-bisphosphatase 1 in cancer: Dual roles, mechanistic insights, and therapeutic potential - A comprehensive review

Fructose-1,6-bisphosphatase 1 (FBP1) is a key gluconeogenic enzyme that plays complex and context-dependent roles in cancer biology. This review comprehensively examines FBP1's dual functions as both a tumor suppressor and an oncogene across various cancer types. In many cancers, such as hepatocellular carcinoma, clear cell renal cell carcinoma, and lung cancer, downregulation of FBP1 contributes to tumor progression through metabolic reprogramming, promoting glycolysis, and altering the tumor microenvironment. Conversely, in certain contexts like breast and prostate cancers, FBP1 overexpression is associated with tumor promotion, indicating its oncogenic potential. The review explores FBP1's interactions with immune cells within the tumor microenvironment, influencing immune surveillance and tumor immune escape mechanisms. Additionally, FBP1 emerges as a promising diagnostic and prognostic biomarker, with expression levels correlating with patient outcomes in multiple cancers. Future therapeutic strategies targeting FBP1 are discussed, including inhibitors, activators, epigenetic modulation, and combination therapies, while addressing the challenges posed by its dual nature. Understanding the multifaceted roles of FBP1 offers valuable insights into cancer metabolism and opens avenues for personalized therapeutic interventions.

Emerging role of PES1 in disease: A promising therapeutic target?

Pescadillo ribosomal biogenesis factor 1 (PES1), a nucleolar protein initially identified in zebrafish, plays an important role in embryonic development and ribosomal biogenesis. Notably, PES1 has been found to be overexpressed in a number of cancer types, where it contributes to tumorigenesis and cancer progression by promoting cell proliferation, suppressing cellular senescence, modulating the tumor microenvironment (TME) and promoting drug resistance in cancer cells. Moreover, recent emerging evidence suggests that PES1 expression is significantly elevated in the livers of Type 2 diabetes mellitus (T2DM) and obese patients, indicating its involvement in the pathogenesis of metabolic diseases through lipid metabolism regulation. In this review, we present the structural characteristics and biological functions of PES1, as well as complexes in which PES1 participates. Furthermore, we comprehensively summarize the multifaceted role of PES1 in various diseases and the latest insights into its underlying molecular mechanisms. Finally, we discuss the potential clinical translational perspectives of targeting PES1, highlighting its promising as a therapeutic intervention and treatment target.

Lactate Utilization Enables Metabolic Escape to Confer Resistance to BET Inhibition in Acute Myeloid Leukemia

Impairing the BET family coactivator BRD4 with small-molecule inhibitors (BETi) showed encouraging preclinical activity in treating acute myeloid leukemia (AML). However, dose-limiting toxicities and limited clinical activity dampened the enthusiasm for BETi as a single agent. BETi resistance in AML myeloblasts was found to correlate with maintaining mitochondrial respiration, suggesting that identifying the metabolic pathway sustaining mitochondrial integrity could help develop approaches to improve BETi efficacy. Herein, we demonstrated that mitochondria-associated lactate dehydrogenase allows AML myeloblasts to utilize lactate as a metabolic bypass to fuel mitochondrial respiration and maintain cellular viability. Pharmacologically and genetically impairing lactate utilization rendered resistant myeloblasts susceptible to BET inhibition. Low-dose combinations of BETi and oxamate, a lactate dehydrogenase inhibitor, reduced in vivo expansion of BETi-resistant AML in cell line and patient-derived murine models. These results elucidate how AML myeloblasts metabolically adapt to BETi by consuming lactate and demonstrate that combining BETi with inhibitors of lactate utilization may be useful in AML treatment.

SIGNIFICANCE

Lactate utilization allows AML myeloblasts to maintain metabolic integrity and circumvent antileukemic therapy, which supports testing of lactate utilization inhibitors in clinical settings to overcome BET inhibitor resistance in AML. See related commentary by Boët and Sarry, p. 950.

Targeting the Metabolic Paradigms in Cancer and Diabetes

Dysregulated metabolic dynamics are evident in both cancer and diabetes, with metabolic alterations representing a facet of the myriad changes observed in these conditions. This review delves into the commonalities in metabolism between cancer and type 2 diabetes (T2D), focusing specifically on the contrasting roles of oxidative phosphorylation (OXPHOS) and glycolysis as primary energy-generating pathways within cells. Building on earlier research, we explore how a shift towards one pathway over the other serves as a foundational aspect in the development of cancer and T2D. Unlike previous reviews, we posit that this shift may occur in seemingly opposing yet complementary directions, akin to the Yin and Yang concept. These metabolic fluctuations reveal an intricate network of underlying defective signaling pathways, orchestrating the pathogenesis and progression of each disease. The Warburg phenomenon, characterized by the prevalence of aerobic glycolysis over minimal to no OXPHOS, emerges as the predominant metabolic phenotype in cancer. Conversely, in T2D, the prevailing metabolic paradigm has traditionally been perceived in terms of discrete irregularities rather than an OXPHOS-to-glycolysis shift. Throughout T2D pathogenesis, OXPHOS remains consistently heightened due to chronic hyperglycemia or hyperinsulinemia. In advanced insulin resistance and T2D, the metabolic landscape becomes more complex, featuring differential tissue-specific alterations that affect OXPHOS. Recent findings suggest that addressing the metabolic imbalance in both cancer and diabetes could offer an effective treatment strategy. Numerous pharmaceutical and nutritional modalities exhibiting therapeutic effects in both conditions ultimately modulate the OXPHOS-glycolysis axis. Noteworthy nutritional adjuncts, such as alpha-lipoic acid, flavonoids, and glutamine, demonstrate the ability to reprogram metabolism, exerting anti-tumor and anti-diabetic effects. Similarly, pharmacological agents like metformin exhibit therapeutic efficacy in both T2D and cancer. This review discusses the molecular mechanisms underlying these metabolic shifts and explores promising therapeutic strategies aimed at reversing the metabolic imbalance in both disease scenarios.

A precise prognostic signature in CTNNB1-mutant hepatocellular carcinoma: Prognosis prediction and precision treatment exploration

Background

CTNNB1 mutates in most hepatocellular carcinoma (HCC) which is the most familiar form of liver cancer with high heterogeneity. It is critical to create a specific prognostication methodology and to investigate additional treatment options for CTNNB1-mutant HCCs.

Methods

A total of 926 samples in five independent cohorts were enrolled in this study, including 127 CTNNB1-mutant samples and 75 estimated CTNNB1-mutant samples. The prognostic signature was constructed by LASSO-Cox regression and evaluated by bioinformatics analyses. The selection of possible drug targets and agents was produced based on the expression profiles and drug sensitivity data of cancer cell lines in two databases.

Results

A prognostic signature based on 15 genes categorized the CTNNB1-mutant HCCs into two groups with different risks. Compared to low-risk patients, high-risk patients had significantly inferior prognoses. ROC curve and multivariate analysis also indicated the superior performance of our signature on the prognosis estimation, particularly in CTNNB1-mutant HCCs. Besides, the nomogram was constructed according to the prognostic signature with excellent predictive performance confirmed by the calibration curve. Subsequently, we suggested that AT-7519 and PHA-793887 might be potential drug agents for high-risk patients.

Conclusion

We established a 15-gene prognostic model, particularly in HCCs with CTNNB1 mutations with good predictive efficiency. Besides, we explored the potential drug targets and agents for patients with high risk. Our findings offered a fresh idea for personalized prognosis management in HCCs with CTNNB1 mutations and threw new insight for precise treatment in HCCs as well.

BAIAP2L2 is a novel prognostic biomarker related to migration and invasion of HCC and associated with cuprotosis

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide, and its pathophysiological mechanisms remain unknown. IRSp53 family members, such as BAIAP2L1, participate in the progression of multiple tumors. However, the role of BAIAP2L2 in HCC remains unclear. This study comprehensively analyzed the potential role of BAIAP2L2 in HCC using bioinformatic techniques. The expression of BAIAP2L2 in HCC was analyzed using The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), International Cancer Genome Consortium (ICGC), and Human Protein Atlas (HPA) databases and in vitro experiments. In addition, the prognostic value of BAIAP2L2 in HCC was analyzed using the TCGA database. TCGA and GEO database were used to analyze the role of BAIAP2L2 in immune features. We also explored the function of BAIAP2L2 in methylation and cuprotosis. The CellMiner database was used to analyze the relationship between BAIAP2L2 expression and drug sensitivity. Our study revealed that BAIAP2L2 is overexpressed in HCC and promotes the migration and invasion of HCC cells. BAIAP2L2 may affect the prognosis of HCC by regulating immunity, methylation, and cuprotosis. BAIAP2L2 is a novel HCC prognostic gene involved in immune infiltration associated with cuprotosis and may be a potential prognosis and therapeutic target for HCC.

Pescadillo ribosomal biogenesis factor 1 reduction suppresses tumour growth and renders chemosensitivity of head and neck squamous cell carcinoma

BACKGROUND

As one of the most devastating cancers, head and neck squamous cell carcinoma (HNSCC) has a short survival time and poor prognosis. Pescadillo ribosomal biogenesis factor 1 (PES1) plays a critical role in the progression of numerous cancers. However, its role and underlying mechanisms in HNSCC remain unclear.

METHODS

A variety of bioinformatic approaches were used to identify the expressions, prognostic and diagnostic value of PES1 in HNSCC. qRT-PCR, immunofluorescence (IF) assay, western blotting and immunohistochemical (IHC) were used to evaluate the expression of PES1 in HNSCC cell lines and clinical tissues. PES1 was knocked down in TU177 and FaDu cells which have high PES1 expression. The effects of PES1 on cell proliferation and tumour growth in HNSCC were elevated by colony formation, CCK8 assays and tumorigenicity assay in nude mice. The effects on cisplatin (CDDP) sensitivity upon silencing of PES1 were assessed using a patient-derived xenograft (PDX) model.

RESULTS

PES1 expression was an independent prognostic factor for HNSCC and negatively associated with the overall survival rate. Silencing of PES1 reduces HNSCC cell proliferation and tumour growth. Moreover, PES1 inhibition significantly sensitises HNSCC cells to cisplatin. Furthermore, we found a PES1 has a high correlation with c-Myc and plays an essential role in the tumour immune microenvironment.

CONCLUSION

Our findings suggest that PES1 is associated with tumour growth and drug resistance and served as a potential cancer marker for diagnosis and a putative therapeutic target for HNSCC.

Sulforaphane Targets the TBX15/KIF2C Pathway to Repress Glycolysis and Cell Proliferation in Gastric Carcinoma Cells

The effects of sulforaphane on glycolysis and proliferation of SGC7901 and BGC823 gastric carcinoma cell lines were analyzed, and the potential mediating role of the TBX15/KIF2C axis was explored. SGC7901 and BGC823 cells stably over- or underexpressing TBX15 were exposed to sulforaphane, and cell viability was assessed together with the expression of TBX15, KIF2C, and proteins involved in glycolysis, glucose uptake, and lactate production. Overexpressing TBX15 in SGC7901 and BGC823 cells significantly reduced glucose uptake, lactate production, cell viability, expression of KIF2C, and pyruvate kinase M2-mediated (PKM2) glycolysis. These effects were recapitulated by treatment with sulforaphane. The anti-tumor effects of sulforaphane were antagonized by down-regulation of TBX15, up-regulation of KIF2C or addition of a PKM2 agonist. Sulforaphane can reduce cell proliferation and PKM2-mediated glycolysis in gastric carcinoma cells, apparently by activating the TBX15/KIF2C pathway.

Targeting super enhancers for liver disease: a review

Background

Super enhancers (SEs) refer to the ultralong regions of a gene accompanied by multiple transcription factors and cofactors and strongly drive the expression of cell-type-related genes. Recent studies have demonstrated that SEs play crucial roles in regulating gene expression related to cell cycle progression and transcription. Aberrant activation of SEs is closely related to the occurrence and development of liver disease. Liver disease, especially liver failure and hepatocellular carcinoma (HCC), constitutes a major class of diseases that seriously endanger human health. Currently, therapeutic strategies targeting SEs can dramatically prevent disease progression and improve the prognosis of animal models. The associated new approaches to the treatment of related liver disease are relatively new and need systematic elaboration.

Objectives

In this review, we elaborate on the features of SEs and discuss their function in liver disease. Additionally, we review their application prospects in clinical practice in the future. The article would be of interest to hepatologists, molecular biologists, clinicians, and all those concerned with targeted therapy and prognosis of liver disease.

Methodology

We searched three bibliographic databases (Web of Science Core Collection, Embase, PubMed) from 01/1981 to 06/2022 for peer-reviewed scientific publications focused on (1) gene treatment of liver disease; (2) current status of SE research; and (3) targeting SEs for liver disease. We included English language original studies only.

Results

The number of published studies considering the role of enhancers in liver disease is considerable. Since SEs were just defined in 2013, the corresponding data on SEs are scarce: approximately 50 papers found in bibliographic databases on the correlation between enhancers (or SEs) and liver disease. Remarkably, half of these papers were published in the past three years, indicating the growing interest of the scientific community in this issue. Studies have shown that treatments targeting components of SEs can improve outcomes in liver disease in animal and clinical trials.

Conclusions

The treatment of liver disease is facing a bottleneck, and new treatments are needed. Therapeutic regimens targeting SEs have an important role in the treatment of liver disease. However, given the off-target effect of gene therapy and the lack of clinical trials, the available experimental data are still fragmented and controversial.

Targeting glycolysis for cancer therapy using drug delivery systems

There is close crosstalk between cancer metabolism and immunity. Cancer metabolism regulation is a promising therapeutic target for cancer immunotherapy. Warburg effect is characterized by abnormal glucose metabolism that includes common features of increased glucose uptake and lactate production. The aerobic glycolysis can reprogram the cancer cells and promote the formation of a suppressive immune microenvironment. As a case in point, lactate plays an essential role in tumorigenesis, which is the end product of glycolysis as well as serves as a fuel supporting cancer cell survival. Meanwhile, it is also an important immune regulator that drives immunosuppression in tumors. Immunometabolic therapy is to intervene tumor metabolism and regulate the related metabolites that participate in the innate and acquired immunity, thereby reinstalling the immune balance and eliciting anticancer immune responses. In this contribution to the Orations - New Horizons of the Journal of controlled Release I will provide an overview of glucose metabolism in tumors and its effects on drug resistance and tumor metastasis, and present the advance of glycolysis-targeting therapy strategies with drug delivery techniques, as well as discuss the challenges in glycolysis-targeting immunometabolic therapy.

Human pre-60S assembly factors link rRNA transcription to pre-rRNA processing

In eukaryotes, the nucleolus is the site of ribosome biosynthesis, an essential process in all cells. While human ribosome assembly is largely evolutionarily conserved, many of the regulatory details underlying its control and function have not yet been well-defined. The nucleolar protein RSL24D1 was originally identified as a factor important for 60S ribosomal subunit biogenesis. In addition, the PeBoW (BOP1-PES1-WDR12) complex has been well-defined as required for pre-28S rRNA processing and cell proliferation. In this study, we show that RSL24D1 depletion impairs both pre-ribosomal RNA (pre-rRNA) transcription and mature 28S rRNA production, leading to decreased protein synthesis and p53 stabilization in human cells. Surprisingly, each of the PeBoW complex members is also required for pre-rRNA transcription. We demonstrate that RSL24D1 and WDR12 co-immunoprecipitate with the RNA polymerase I subunit, RPA194, and regulate its steady state levels. These results uncover the dual role of RSL24D1 and the PeBoW complex in multiple steps of ribosome biogenesis, and provide evidence implicating large ribosomal subunit biogenesis factors in pre-rRNA transcription control.

The BRCT Domain from the Homologue of the Oncogene PES1 in Leishmania major (LmjPES) Promotes Malignancy and Drug Resistance in Mammalian Cells

Around 15% of cancer cases are attributable to infectious agents. Epidemiological studies suggest that an association between leishmaniasis and cancer does exist. Recently, the homologue of PES1 in Leishmania major (LmjPES) was described to be involved in parasite infectivity. Mammalian PES1 protein has been implicated in cellular processes like cell cycle regulation. Its BRCT domain has been identified as a key factor in DNA damage-responsive checkpoints. This work aimed to elucidate the hypothetical oncogenic implication of BRCT domain from LmjPES in host cells. We generated a lentivirus carrying this BRCT domain sequence (lentiBRCT) and a lentivirus expressing the luciferase protein (lentiLuc), as control. Then, HEK293T and NIH/3T3 mammalian cells were infected with these lentiviruses. We observed that the expression of BRCT domain from LmjPES conferred to mammal cells in vitro a greater replication rate and higher survival. In in vivo experiments, we observed faster tumor growth in mice inoculated with lentiBRCT respect to lentiLuc HEK293T infected cells. Moreover, the lentiBRCT infected cells were less sensitive to the genotoxic drugs. Accordingly, gene expression profiling analysis revealed that BRCT domain from LmjPES protein altered the expression of proliferation- (DTX3L, CPA4, BHLHE41, BMP2, DHRS2, S100A1 and PARP9), survival- (BMP2 and CARD9) and chemoresistance-related genes (DPYD, Dok3, DTX3L, PARP9 and DHRS2). Altogether, our results reinforced the idea that in eukaryotes, horizontal gene transfer might be also achieved by parasitism like Leishmania infection driving therefore to some crucial biological changes such as proliferation and drug resistance.

Licochalcone A inhibits cell growth through the downregulation of the Hippo pathway via PES1 in cholangiocarcinoma cells

Overexpression or activation of Yes-associated protein (YAP) is common in cancer cells. Thus, targeting YAP may be a strategy for cancer therapy. Licochalcone A (LicA) is a primary active compound of licorice root and is known to have medicinal effects, such as antioxidant, antibacterial, antiviral, and anticancer effects. However, the anticancer pharmacological mechanism of LicA has not been investigated in cholangiocarcinoma. In this study, we investigated the antiproliferative effect of LicA and the underlying molecular mechanism in HCCC-9810 and RBE human cholangiocarcinoma cells. Our experiments indicated that LicA suppressed the growth of cholangiocarcinoma cells through inactivation of the Hippo pathway. Pescadillo ribosomal biogenesis factor 1 (PES1) was notably upregulated and related to carcinogenesis. We also found that LicA suppressed the expression and nuclear localization of PES1, which was associated with the inhibition of YAP expression and transcriptional activity.

Bromodomain and extra-terminal inhibitors emerge as potential therapeutic avenues for gastrointestinal cancers

Gastrointestinal (GI) cancers, including colorectal cancer, pancreatic cancer, liver cancer and gastric cancer, are severe social burdens due to high incidence and mortality rates. Bromodomain and extra-terminal (BET) proteins are epigenetic readers consisting of four conserved members (BRD2, BRD3, BRD4 and BRDT). BET family perform pivotal roles in tumorigenesis through transcriptional regulation, thereby emerging as potential therapeutic targets. BET inhibitors, disrupting the interaction between BET proteins and acetylated lysines, have been reported to suppress tumor initiation and progression in most of GI cancers. In this review, we will demonstrate how BET proteins participate in the GI cancers progression and highlight the therapeutic potential of targeting BET proteins for GI cancers treatment.

The functional role of Pescadillo ribosomal biogenesis factor 1 in cancer

Tumors are neogrowths formed by the growth of normal cells or tissues through complex mechanisms under the influence of many factors. The occurrence and development of tumors are affected by many factors. Pescadillo ribosomal biogenesis factor 1 (PES1) has been identified as a cancer-related gene. The study of these genes may open up new avenues for early diagnosis, treatment and prognosis of tumors. As a nucleolar protein and part of the Pes1/Bop1/WDR12 (PeBoW) complex, PES1 is involved in ribosome biogenesis and DNA replication. Many studies have shown that high expression of PES1 is often closely related to the occurrence, proliferation, invasion, metastasis, prognosis and sensitivity to chemotherapeutics of various human malignant tumors through a series of molecular mechanisms and signaling pathways. The molecules that regulate the expression of PES1 include microRNA (miRNA), circular RNA (circRNA), c-Jun, bromodomain-containing protein 4 (BRD4) and nucleolar phosphoprotein B23. However, the detailed pathogenic mechanisms of PES1 overexpression in human malignancies remains unclear. This article summarizes the role of PES1 in the carcinogenesis, prognosis and treatment of multiple tumors, and introduces the molecular mechanisms and signal transduction pathways related to PES1.

Ketogenic diet ameliorates lipid dysregulation in type 2 diabetic mice by downregulating hepatic pescadillo 1

Background

Previous reports implied a possible link between PES1 and lipid metabolism. However, the role of PES1 in regulating T2DM related lipid metabolism and the effect of ketogenic diet (KD) on PES1 have not been reported. The aim of present study is to explore the role of PES1 in effects of KD on diabetic mice and its mediated mechanism.

Methods

Male C57BL/6J and KKA^y mice were fed with standard diet (SD) and KD, respectively. Simultaneously, McArdle 7777 cells were treated by β-hydroxybutyric acid (β-HB), Pes1 siRNA or Pes1 overexpression plasmid, respectively. Additionally, liver-conditional knockout (CKO) of Pes1 in vivo was applied.

Results

Hepatic PES1 expression in diabetic mice was markedly increased, which was suppressed by KD feeding with an accompanying reduction of hepatic and plasma triglycerides (TG). In mice with CKO of Pes1, the protein levels of p300, SREBP1c, FASN, SCD1, Caspase1, NLRP3 and GSDMD were dramatically downregulated in livers, and the plasma and hepatic TG, IL-1β and IL-18 were decreased as well. The similar outcomes were also observed in β-HB and Pes1 knockdown treated hepatocytes. By contrast, Pes1 overexpression in cultured hepatocytes showed that these levels were significantly enhanced, which were, however reduced under β-HB treatment. Mechanistically, we discovered that β-HB decreased CHOP binding to the Pes1 promoters, resulting in the downregulation of PES1, thereby reducing PES1 binding to p300 and Caspase1 promoters. The inhibition of p300 and Caspase1 expression elicited the dramatic suppression of acetylation of SREBP1c via its interaction with p300, and the decreased GSDMD levels. Besides, knockdown of Caspase1 also alleviated the TG levels in cultured hepatocytes.

Conclusion

KD may improve lipid dysregulation in type 2 diabetic mice by downregulating hepatic PES1 expression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-021-00429-6.

In Leishmania major, the Homolog of the Oncogene PES1 May Play a Critical Role in Parasite Infectivity

Leishmaniasis is a neglected tropical disease caused by Leishmania spp. The improvement of existing treatments and the discovery of new drugs remain ones of the major goals in control and eradication of this disease. From the parasite genome, we have identified the homologue of the human oncogene PES1 in Leishmania major (LmjPES). It has been demonstrated that PES1 is involved in several processes such as ribosome biogenesis, cell proliferation and genetic transcription. Our phylogenetic studies showed that LmjPES encodes a highly conserved protein containing three main domains: PES N-terminus (shared with proteins involved in ribosomal biogenesis), BRCT (found in proteins related to DNA repair processes) and MAEBL-type domain (C-terminus, related to erythrocyte invasion in apicomplexan). This gene showed its highest expression level in metacyclic promastigotes, the infective forms; by fluorescence microscopy assay, we demonstrated the nuclear localization of LmjPES protein. After generating mutant parasites overexpressing LmjPES, we observed that these clones displayed a dramatic increase in the ratio of cell infection within macrophages. Furthermore, BALB/c mice infected with these transgenic parasites exhibited higher footpad inflammation compared to those inoculated with non-overexpressing parasites.

Upregulation of GTPBP4 Promotes the Proliferation of Liver Cancer Cells

RESULTS

The GTPBP4 has upregulated expression in liver cancer patients (P < 0.01), but there was no difference in its expression in patients with different clinicopathological stages. The expression of GTPBP4 increased with the increase of cancer metastasis in lymph nodes (P < 0.01). Liver cancer patients with upregulated expression of GTPBP4 showed a shorter overall survival rate (P=0.02). GTPBP4 is closely related to genes such as NIFK, WDR12, and RPF2, and these genes are involved in life processes such as GTP binding and rRNA processing. The upregulated expression of GTPBP4 promotes the proliferation of liver cancer cells and promotes the growth of tumors in mice, while the downregulated expression of GTPBP4 inhibits the proliferation of liver cancer cells and inhibits the growth of tumors in mice.

CONCLUSION

The expression of GTPBP4 is upregulated in liver cancer patients and affects the overall survival rate of patients. The upregulated expression of GTPBP4 promotes the proliferation of liver cancer cells and the growth of tumors.

Histone acetyltransferase 1 promotes gemcitabine resistance by regulating the PVT1/EZH2 complex in pancreatic cancer

The poor prognosis of pancreatic cancer is primarily due to the development of resistance to therapies, including gemcitabine. The long noncoding RNA PVT1 (lncRNA PVT1) has been shown to interact with enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2), promoting gemcitabine resistance in pancreatic cancer. In this study, we found histone acetyltransferase 1 (HAT1) enhanced the tolerance of pancreatic cancer cells to gemcitabine and HAT1-mediated resistance mechanisms were regulated by PVT1 and EZH2. Our results showed that the aberrant HAT1 expression promoted gemcitabine resistance, while silencing HAT1 restored gemcitabine sensitivity. Moreover, HAT1 depletion caused a notable increase of gemcitabine sensitivity in gemcitabine-resistant pancreatic cancer cell lines. Further research found that HAT1 increased PVT1 expression to induce gemcitabine resistance, which enhanced the binding of bromodomain containing 4 (BRD4) to the PVT1 promoter, thereby promoting PVT1 transcription. Besides, HAT1 prevented EZH2 degradation by interfering with ubiquitin protein ligase E3 component n-recognin 4 (UBR4) binding to the N-terminal domain of EZH2, thus maintaining EZH2 protein stability to elevate the level of EZH2 protein, which also promoted HAT1-mediated gemcitabine resistance. These results suggested that HAT1 induced gemcitabine resistance of pancreatic cancer cells through regulating PVT1/EZH2 complex. Given this, Chitosan (CS)-tripolyphosphate (TPP)-siHAT1 nanoparticles were developed to block HAT1 expression and improve the antitumor effect of gemcitabine. The results showed that CS-TPP-siHAT1 nanoparticles augmented the antitumor effects of gemcitabine in vitro and in vivo. In conclusion, HAT1-targeted therapy can improve observably gemcitabine sensitivity of pancreatic cancer cells. HAT1 is a promising therapeutic target for pancreatic cancer.

BET inhibitor suppresses migration of human hepatocellular carcinoma by inhibiting SMARCA4

Hepatocellular carcinoma (HCC) is one of the most prevalent and poorly responsive cancers worldwide. Bromodomain and extraterminal (BET) inhibitors, such as JQ1 and OTX-015, inhibit BET protein binding to acetylated residues in histones. However, the physiological mechanisms and regulatory processes of BET inhibition in HCC remain unclear. To explore BET inhibitors’ potential role in the molecular mechanisms underlying their anticancer effects in HCC, we analyzed BET inhibitor-treated HCC cells’ gene expression profiles with RNA-seq and bioinformatics analysis. BET inhibitor treatment significantly downregulated genes related to bromodomain-containing proteins 4 (BRD4), such as ACSL5, SLC38A5, and ICAM2. Importantly, some cell migration-related genes, including AOC3, CCR6, SSTR5, and SCL7A11, were significantly downregulated. Additionally, bioinformatics analysis using Ingenuity Knowledge Base Ingenuity Pathway Analysis (IPA) revealed that SMARCA4 regulated migration response molecules. Furthermore, knockdown of SMARCA4 gene expression by siRNA treatment significantly reduced cell migration and the expression of migration-related genes. In summary, our results indicated that BET inhibitor treatment in HCC cell lines reduces cell migration through the downregulation of SMARCA4.

SOD1 regulates ribosome biogenesis in KRAS mutant non-small cell lung cancer

SOD1 is known as the major cytoplasmic superoxide dismutase and an anticancer target. However, the role of SOD1 in cancer is not fully understood. Herein we describe the generation of an inducible Sod1 knockout in KRAS-driven NSCLC mouse model. Sod1 knockout markedly reduces tumor burden in vivo and blocks growth of KRAS mutant NSCLC cells in vitro. Intriguingly, SOD1 is enriched in the nucleus and notably in the nucleolus of NSCLC cells. The nuclear and nucleolar, not cytoplasmic, form of SOD1 is essential for lung cancer cell proliferation. Moreover, SOD1 interacts with PeBoW complex and controls its assembly necessary for pre-60S ribosomal subunit maturation. Mechanistically, SOD1 regulates co-localization of PeBoW with and processing of pre-rRNA, and maturation of cytoplasmic 60S ribosomal subunits in KRAS mutant lung cancer cells. Collectively, our study unravels a nuclear SOD1 function essential for ribosome biogenesis and proliferation in KRAS-driven lung cancer.

Enolase 1 regulates stem cell-like properties in gastric cancer cells by stimulating glycolysis

Recent studies have demonstrated that gastric cancer stem cells (CSCs) are a rare sub-group of gastric cancer (GC) cells and have an important role in promoting the tumor growth and progression of GC. In the present study, we demonstrated that the glycolytic enzyme Enolase 1 (ENO1) was involved in the regulation of the stem cell-like characteristics of GC cells, as compared to the parental cell lines PAMC-82 and SNU16, the expression of ENO1 in spheroids markedly increased. We then observed that ENO1 could enhance stem cell-like characteristics, including self-renewal capacity, cell invasion and migration, chemoresistance, and even the tumorigenicity of GC cells. ENO1 is known as an enzyme that is involved in glycolysis, but our results showed that ENO1 could markedly promote the glycolytic activity of cells. Furthermore, inhibiting glycolysis activity using 2-deoxy-D-glucose treatment significantly reduced the stemness of GC cells. Therefore, ENO1 could improve the stemness of CSCs by enhancing the cells' glycolysis. Subsequently, to further confirm our results, we found that the inhibition of ENO1 using AP-III-a4 (ENOblock) could reduce the stemness of GC cells to a similar extent as the knockdown of ENO1 by shRNA. Finally, increased expression of ENO1 was related to poor prognosis in GC patients. Taken together, our results demonstrated that ENO1 is a significant biomarker associated with the stemness of GC cells.

PES1 In Liver Cancer: A Prognostic Biomarker With Tumorigenic Roles

PURPOSE

Liver cancer has a high incidence of mortality. DNA replication and posttranscriptional modifications play important roles in the development of liver cancer. Pescadillo (PES1) is a nuclear protein that is involved in embryonic development, ribosome synthesis, DNA replication, and cell cycle progression. Recently, abnormal PES1 expression was reported in several tumors, including neuroblastoma, colon cancer, gastric cancer, and breast cancer. Based on bio-informatic analysis, cell experiments and animal models, the aim of this study is to investigate the expression patterns and specific roles of PES1 in liver cancer.

PATIENTS AND METHODS

PES1 expression was represented by boxplots. The correlation between PES1 expression and clinical features was assessed by the chi-squared test and Fisher's exact tests. Kaplan-Meier curves compared overall survival between different levels of PES1 expression, and Cox analysis selected potential variables associated with overall survival. The MTT assay investigated the proliferation rate, the scratch assay assessed the migratory ability, and the Transwell assay evaluated the invasion capacity of tumor cells in vitro. Animal models were used to confirm the tumorigenic roles of PES1 in vivo. GSEA illustrated the molecular mechanisms that PES1 participated in.

RESULTS

We found that PES1 was highly expressed in liver cancer tissues, served as a diagnostic marker, and correlated with poor overall survival (OS) and relapse-free survival (RFS) in patients. In vitro studies indicated that PES1 promoted tumor cell proliferation (P=0.0034), migration (P=0.0026), and invasion (P=0.0008), and this tumorigenic role was confirmed in animal models. GSEA further illuminated molecular mechanisms that PES1 participated in liver cancer occurrence and progression.

CONCLUSION

This study suggested that PES1 was upregulated in liver cancer and correlated with poor prognosis, by promoting tumor cell proliferation, migration, and invasion, and PES1 may be a novel diagnostic and prognostic bio-marker and a promising therapeutic target in liver cancer.

PES1 promotes BET inhibitors resistance and cells proliferation through increasing c-Myc expression in pancreatic cancer

Background

Overexpressed PES1 promotes carcinogenesis in various types of malignant tumors. However, the biological role and clinical significance of PES1 in pancreatic cancer are still unexplored.

Methods

The expression level of PES1 in pancreatic cancer cell lines and pancreatic cancer patient samples was determined using Western Blotting analysis, RT-qPCR analysis, immunohistochemical (IHC) analysis of tissue microarray, and the GEPIA web tool. MTS assay, colony formation assay, and xenograft tumor assay were used to evaluate the tumor growth ability of pancreatic cancer cells.

Results

We established that the expression of PES1 was abnormally increased in pancreatic cancer tissues and led to poor prognosis of pancreatic cancer patients. We also found that PES1 was responsible for promoting cell growth and contributed to bromodomain and cancer cell resistance to extra-terminal (BET) inhibitors in pancreatic cancer. Furthermore, we showed that PES1 interacted with BRD4 to enhance c-Myc expression, which is the primary cause of cancer cell resistance to BET inhibitors in pancreatic cancer. Finally, CDK5 inhibitors were proven to destabilize PES1 and overcome cancer cell resistance to BET inhibitors in pancreatic cancer cells.

Conclusions

We have shown that PES1 could be one of the promoting factors of tumor growth and a prognosis-related protein of pancreatic cancer. Targeting PES1 with CDK5 inhibitors might help overcome cancer cell resistance to BET inhibitors in pancreatic cancer cells.

HDAC3 modulates cancer immunity via increasing PD-L1 expression in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is the second leading cause of cancer-related deaths worldwide. Despite immune checkpoints based immunotherapy highlights a new therapeutic strategy and achieves a remarkable therapeutic effect in various types of malignant tumors. Pancreatic cancer is one of the non-immunogenic cancers and is resistant to immunotherapy. Programmed death ligand 1 (PD-L1) is expressed on the surface of tumor cells and its level is a key determinant of the checkpoint immunotherapy efficacy. Here, we reported that the specific inhibitor of histone deacetylase 3 (HDAC3) decreased the protein and mRNA level of PD-L1 in pancreatic cancer cells. Furthermore, we showed that HDAC3 was critical for PD-L1 regulation and positively correlated with PD-L1 in PDAC patient specimens. Finally, we demonstrated that HDAC3/signal transducer and activator of transcription 3 (STAT3) pathway transcriptionally regulated PD-L1 expression. Collectively, our data contributes to a better understanding of the function of HDAC3 in cancer immunity and the regulatory mechanism of PD-L1. More importantly, these data suggest that the HDAC3 inhibitors might be used to improve immunotherapy in pancreatic cancer.

Overexpressed histone acetyltransferase 1 regulates cancer immunity by increasing programmed death-ligand 1 expression in pancreatic cancer

BACKGROUND

Pancreatic ductal adenocarcinoma is one of the leading causes of cancer-related death worldwide. Immune checkpoint blockade therapy, including anti-PD-1 and anti-PD-L1, is a new therapeutic strategy for cancer treatment but the monotherapy with PD-L1 inhibitors for pancreatic cancer is almost ineffective for pancreatic cancer. Thus, exploring the regulatory mechanism of PD-L1 in cancer cells, especially in pancreatic cancer cells, is one of the key strategies to improving cancer patient response to PD-L1 blockade therapy. Histone acetyltransferase 1(HAT1) is a classic type B histone acetyltransferase and the biological role of HAT1 in pancreatic cancer is unclear.

METHODS

The clinical relevance of HAT1 was examined by the GEPIA web tool, Western blotting and immunohistochemistry of pancreatic cancer tissue microarray slides. Tumor cell motility was investigated by MTS assay, colony formation assay and xenografts. The relationship between HAT1 and PD-L1 was examined by Western blot analysis, RT-qPCR and immunohistochemistry.

RESULTS

HAT1 was upregulated in PDAC and associated with poor prognosis in PDAC patients. The knockdown of HAT1 decreased the proliferation of pancreatic cancer cells in vivo and in vitro. Strikingly, we showed that HAT1 transcriptionally regulated PD-L1, and this process was mainly mediated by BRD4 in pancreatic cancer. The knockdown of HAT1 improved the efficacy of immune checkpoint blockade by decreasing the PD-L1.

CONCLUSIONS

The recognition of HAT1 in regulating tumor cell proliferation and cancer immunity indicated that HAT1 might be employed as a new diagnostic and prognostic marker and a predictive marker for pancreatic cancer therapy, especially in immune checkpoint blockade therapy. Targeting HAT1 highlights a novel therapeutic approach to overcome immune evasion by tumor cells.

B7-H3 is regulated by BRD4 and promotes TLR4 expression in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies worldwide. PDAC is resistant to chemotherapy and radiotherapy which leads to the poor prognosis of PDAC patients and a 5-year survival rate of less than 5%. Exploring the mechanism of the pancreatic cancer tumorigenesis is the key to finding a novel therapeutic strategy for cancer treatment. B7-H3 belongs to the B7 family of immunoregulatory proteins, and the overexpression of B7-H3 is found in various types of cancer. The regulation of B7-H3 expression in pancreatic cancer is still unclear. Here, we showed that B7-H3 acted as a negative prognostic biomarker in PDAC and promoted cell proliferation, invasion and metastasis in pancreatic cancer. Next, we applied the drug screening method to identify bromodomain and extra-terminal motif (BET) inhibitors that decreased the protein and mRNA levels of B7-H3 in pancreatic cancer cells. Moreover, we verified that BRD4 was responsible for regulating the expression of B7-H3 at the transcriptional level. Finally, our data indicated that the BRD4/B7-H3 axis modulated the expression of TLR4 in pancreatic cancer cells. Taken together, our results elucidated the regulation of B7-H3 expression in pancreatic cancer and uncovered the importance of BRD4/B7-H3/TLR4 pathway. The targeting of B7-H3 by the BET inhibitors may be a novel therapeutic strategy to overcome the immunotherapy and chemotherapy resistance in pancreatic cancer.

PES1 enhances proliferation and tumorigenesis in hepatocellular carcinoma via the PI3K/AKT pathway

AIM

We investigated the potential role of pescadillo ribosomal biogenesis factor 1 (PES1) in the development of hepatocellular carcinoma (HCC).

MATERIAL AND METHODS

One hundred and thirty-four patients with hepatocellular carcinoma were chosen to evaluate the association between the expression of PES1 and survival, clinical characteristics of these patients. Western blotting, real-time PCR, immunohistochemistry, CCK-8 assay, colony formation and subcutaneous tumors in nude mice were conducted.

KEY FINDINGS

We found that PES1 was commonly upregulated in HCC tissues and cells. Immunohistochemical analysis of 134 paraffin-embedded archived HCC tissues showed that the protein expression level of PES1 was positively correlated with clinical characteristics and reduced the survival time of HCC patients. Univariate and multivariate analysis revealed that PES1 expression may be an independent prognostic indicator of poorer overall survival in HCC patients. Furthermore, silencing of endogenous PES1 significantly inhibited the proliferation and tumorigenicity of SMMC 7721 and HepG2 cells in vitro as well as in vivo in nude mice. Finally, we found that PES1 affected cell proliferation by regulating the PI3K/AKT/GSK3β/cyclinD1 signaling pathway.

SIGNIFICANCE

Our data suggest that PES1 may promote proliferation and tumorigenicity, and potentially representing a novel prognostic marker for overall survival in HCC.

CORE TIP

We report that pescadillo ribosomal biogenesis factor 1 (PES1) plays an oncogenic role in hepatocellular carcinoma, which was commonly upregulated in hepatocellular carcinoma tissues and cells. Immunostaining analysis found that the protein expression level of PES1 was positively correlated with clinical characteristics and reduced survival time of hepatocellular carcinoma patients. Multivariate analysis revealed that PES1 expression might be an independent prognostic indicator of survival in hepatocellular carcinoma patients. Furthermore, PES1 knockdown inhibited the proliferation and tumorigenesis in hepatocellular carcinoma cell lines. Additionally, we found that PES1 is involved in the cell proliferation by regulating the AKT/GSK3β/cyclinD1 signaling pathway.