EEF1A2 inactivates p53 by way of PI3K/AKT/mTOR-dependent stabilization of MDM4 in hepatocellular carcinoma

Stratifin-mediated activation of AKT signaling and therapeutic targetability in hepatocellular carcinoma progression

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide and presents a significant threat to human health. Despite its prevalence, the underlying regulatory mechanisms of HCC remain unclear. In this study, we integrated RNA-seq datasets, proteome dataset and survival analysis and unveiled Stratifin (SFN) as a potential prognostic biomarker for HCC. SFN knockdown inhibited HCC progression in cell cultures and mouse models. Conversely, ectopic expression of Sfn in primary mouse HCC model accelerated HCC progression. Mechanistically, SFN acted as an adaptor protein, activating AKT1 signaling by fostering the interaction between PDK1 and AKT1, with the R56 and R129 sites on SFN proving to be crucial for this binding. In the syngeneic implantation model, the R56A/R129A mutant of SFN inhibited Akt signaling activation and impeded HCC growth. Additionally, peptide inhibitors designed based on the binding motif of AKT1 to SFN significantly inhibited HCC progression. In summary, our findings establish that SFN promotes HCC progression by activating AKT signaling through the R56 and R129 binding sites. This discovery opens new avenues for a promising therapeutic strategy for the treatment of HCC.

High expression of eukaryotic elongation factor 1-alpha-2 in lung adenocarcinoma is associated with poor prognosis

Eukaryotic elongation factor 1 alpha 2 (eEF1A2) encodes an isoform of the alpha subunit of the elongation factor 1 complex and is responsible for the enzymatic delivery of aminoacyl tRNA to the ribosome. Our proteomic analysis has identified eEF1A2 as one of the proteins expressed during malignant progression from adenocarcinoma in situ (AIS) to early invasive lung adenocarcinoma. The expression level of eEF1A2 in 175 lung adenocarcinomas was examined by immunohistochemical staining in relation to patient prognosis and clinicopathological factors. Quantitative PCR analysis and fluorescence in situ hybridization (FISH) were performed to evaluate the amplification of the eEF1A2 gene. Relatively high expression of eEF1A2 was observed in invasive adenocarcinoma (39/144 cases) relative to minimally invasive adenocarcinoma (1/10 cases) or AIS (0/21 cases). Among invasive adenocarcinomas, solid-type adenocarcinoma (15/32 cases, 47%) showed higher expression than other histological subtypes (23/92, 25%). Patients with eEF1A2-positive tumors had a significantly poorer prognosis than those with eEF1A2-negative tumors. Of the five tumors that were eEF1A2-positive, two cases showed amplified genomic eEF1A2 DNA, which was confirmed by both qPCR and FISH. These findings indicate that eEF1A2 overexpression occurs in the course of malignant transformation of lung adenocarcinomas and is partly due to eEF1A2 gene amplification.

Epigenetic silencing of KCTD8 promotes hepatocellular carcinoma growth by activating PI3K/AKT signaling

Aim: The aim of current study is to explore the epigenetic changes and function of KCTD8 in human hepatocellular carcinoma (HCC). Materials & methods: HCC cell lines and tissue samples were employed. Methylation specific PCR, flow cytometry, immunoprecipitation and xenograft mouse models were used.Results: KCTD8 was methylated in 44.83% (104/232) of HCC and its methylation may act as an independent poor prognostic marker. KCTD8 expression was regulated by DNA methylation. KCTD8 suppressed HCC cell growth both in vitro and in vivo via inhibiting PI3K/AKT pathway.Conclusion: Methylation of KCTD8 is an independent poor prognostic marker, and epigenetic silencing of KCTD8 increases the malignant tendency in HCC.

The eEF1A protein in cancer: Clinical significance, oncogenic mechanisms, and targeted therapeutic strategies

Eukaryotic elongation factor 1A (eEF1A) is among the most abundant proteins in eukaryotic cells. Evolutionarily conserved across species, eEF1A is in charge of translation elongation for protein biosynthesis as well as a plethora of non-translational moonlighting functions for cellular homeostasis. In malignant cells, however, eEF1A becomes a pleiotropic driver of cancer progression via a broad diversity of pathways, which are not limited to hyperactive translational output. In the past decades, mounting studies have demonstrated the causal link between eEF1A and carcinogenesis, gaining deeper insights into its multifaceted mechanisms and corroborating its value as a prognostic marker in various cancers. On the other hand, an increasing number of natural and synthetic compounds were discovered as anticancer eEF1A-targeting inhibitors. Among them, plitidepsin was approved for the treatment of multiple myeloma whereas metarrestin was currently under clinical development. Despite significant achievements in these two interrelated fields, hitherto there lacks a systematic examination of the eEF1A protein in the context of cancer research. Therefore, the present work aims to delineate its clinical implications, molecular oncogenic mechanisms, and targeted therapeutic strategies as reflected in the ever expanding body of literature, so as to deepen mechanistic understanding of eEF1A-involved tumorigenesis and inspire the development of eEF1A-targeted chemotherapeutics and biologics.

Ficolin 3 promotes ferroptosis in HCC by downregulating IR/SREBP axis-mediated MUFA synthesis

BACKGROUND

Targeting ferroptosis has been identified as a promising approach for the development of cancer therapies. Monounsaturated fatty acid (MUFA) is a type of lipid that plays a crucial role in inhibiting ferroptosis. Ficolin 3 (FCN3) is a component of the complement system, serving as a recognition molecule against pathogens in the lectin pathway. Recent studies have reported that FCN3 demonstrates inhibitory effects on the progression of certain tumors. However, whether FCN3 can modulate lipid metabolism and ferroptosis remains largely unknown.

METHODS

Cell viability, BODIPY-C11 staining, and MDA assay were carried out to detect ferroptosis. Primary hepatocellular carcinoma (HCC) and xenograft models were utilized to investigate the effect of FCN3 on the development of HCC in vivo. A metabonomic analysis was conducted to assess alterations in intracellular and HCC intrahepatic lipid levels.

RESULTS

Our study elucidates a substantial decrease in the expression of FCN3, a component of the complement system, leads to MUFA accumulation in human HCC specimens and thereby significantly promotes ferroptosis resistance. Overexpression of FCN3 efficiently sensitizes HCC cells to ferroptosis, resulting in the inhibition of the oncogenesis and progression of both primary HCC and subcutaneous HCC xenograft. Mechanistically, FCN3 directly binds to the insulin receptor β (IR-β) and its pro-form (pro-IR), inhibiting pro-IR cleavage and IR-β phosphorylation, ultimately resulting in IR-β inactivation. This inactivation of IR-β suppresses the expression of sterol regulatory element binding protein-1c (SREBP1c), which subsequently suppresses the transcription of genes related to de novo lipogenesis (DNL) and lipid desaturation, and consequently downregulates intracellular MUFA levels.

CONCLUSIONS

These findings uncover a novel regulatory mechanism by which FCN3 enhances the sensitivity of HCC cells to ferroptosis, indicating that targeting FCN3-induced ferroptosis is a promising strategy for HCC treatment.

Discovery of a nitroaromatic nannocystin with potent in vivo anticancer activity against colorectal cancer by targeting AKT1

The development of targeted chemotherapeutic agents against colorectal cancer (CRC), one of the most common cancers with a high mortality rate, is in a constant need. Nannocystins are a family of myxobacterial secondary metabolites featuring a 21-membered depsipeptide ring. The in vitro anti-CRC activity of natural and synthetic nannocystins was well documented, but little is known about their in vivo efficacy and if positive, the underlying mechanism of action. In this study we synthesized a nitroaromatic nannocystin through improved preparation of a key fragment, and characterized its in vitro activity and in vivo efficacy against CRC. We first described the total synthesis of compounds 2-4 featuring Heck macrocyclization to forge their 21-membered macrocycle. In a panel of 7 cancer cell lines from different tissues, compound 4 inhibited the cell viability with IC values of 1-6 nM. In particular, compound 4 (1, 2, 4 nM) inhibited the proliferation of CRC cell lines (HCT8, HCT116 and LoVo) in both concentration and time dependent manners. Furthermore, compound 4 concentration-dependently inhibited the colony formation and migration of CRC cell lines. Moreover, compound 4 induced cell cycle arrest at sub-G1 phase, apoptosis and cellular senescence in CRC cell lines. In three patient-derived CRC organoids, compound 4 inhibited the PDO with IC values of 3.68, 28.93 and 11.81 nM, respectively. In a patient-derived xenograft mouse model, injection of compound 4 (4, 8 mg/kg, i.p.) every other day for 12 times dose-dependently inhibited the tumor growth without significant change in body weight. We conducted RNA-sequencing, molecular docking and cellular thermal shift assay to elucidate the anti-CRC mechanisms of compound 4, and revealed that it exerted its anti-CRC effect at least in part by targeting AKT1.

A pan-cancer analysis of the prognosis and immune infiltration of eEF1A2 and its potential function in thyroid carcinoma

Purpose

Eukaryotic translation elongation factor 1α2 (eEF1A2) promotes tumour progression in various cancers. We performed a pan-cancer analysis of eEF1A2 and explored its role in thyroid carcinoma (THCA).

Methods

Databases from The Cancer Genome Atlas (TCGA), the University of Alabama at Birmingham Cancer data analysis Portal (UALCAN), and the Human Protein Atlas (HPA) were used to investigate the differential expression of eEF1A2 in pan-cancer. The pathological stage, prognostic characteristics, tumour microenvironment (TME), tumour mutational burden (TMB), and microsatellite instability (MSI) were analysed in diverse tumours with different expression levels of eEF1A2. The expression levels in papillary thyroid carcinoma (PTC) and its specific role in cell proliferation, migration, invasion, and cell glycolysis in PTC cells were verified by quantitative real time polymerase chain reaction (qRT-PCR), immunohistochemistry, cell counting kit-8, colony formation, wound healing, Transwell assay, and lactate acid and glucose assays.Results:eEF1A2 was differentially expressed in various malignant tumour tissues compared to control tissues and was associated with poor pathological stage and prognosis in most types of tumours. Moreover, eEF1A2 expression closely correlated with the infiltration of immunosuppressive cells, TMB, and MSI in some tumour types. Expression of eEF1A2 in PTC is higher than the para-carcinoma, and eEF1A2 downregulation suppressed TPC-1 and BCPAP cell proliferation, migration, invasion, and glycolysis.

Conclusion

Our study suggests that the expression of eEF1A2 is related to the prognosis and immune infiltration of some tumours and may be a predictor of prognosis and immunotherapy. eEF1A2 could promote malignant behaviour of PTC cells.

EEF1A2 promotes HIF1A mediated breast cancer angiogenesis in normoxia and participates in a positive feedback loop with HIF1A in hypoxia

BACKGROUND

The eukaryotic elongation factor, EEF1A2, has been identified as an oncogene in various solid tumors. Here, we have identified a novel function of EEF1A2 in angiogenesis.

METHODS

Chick chorioallantoic membrane, tubulogenesis, aortic ring, Matrigel plug, and skin wound healing assays established EEF1A2's role in angiogenesis.

RESULT

Higher EEF1A2 levels in breast cancer cells enhanced cell growth, movement, blood vessel function, and tubule formation in HUVECs, as confirmed by ex-ovo and in-vivo tests. The overexpression of EEF1A2 could be counteracted by Plitidepsin. Under normoxic conditions, EEF1A2 triggered HIF1A expression via ERK-Myc and mTOR signaling in TNBC and ER/PR positive cells. Hypoxia induced the expression of EEF1A2, leading to a positive feedback loop between EEF1A2 and HIF1A. Luciferase assay and EMSA confirmed HIF1A binding on the EEF1A2 promoter, which induced its transcription. RT-PCR and polysome profiling validated that EEF1A2 affected VEGF transcription and translation positively. This led to increased VEGF release from breast cancer cells, activating ERK and PI3K-AKT signaling in endothelial cells. Breast cancer tissues with elevated EEF1A2 showed higher microvessel density.

CONCLUSION

EEF1A2 exhibits angiogenic potential in both normoxic and hypoxic conditions, underscoring its dual role in promoting EMT and angiogenesis, rendering it a promising target for cancer therapy.

MDMX in Cancer: A Partner of p53 and a p53-Independent Effector

The p53 tumor suppressor protein plays an important role in physiological and pathological processes. MDM2 and its homolog MDMX are the most important negative regulators of p53. Many studies have shown that MDMX promotes the growth of cancer cells by influencing the regulation of the downstream target gene of tumor suppressor p53. Studies have found that inhibiting the MDMX-p53 interaction can effectively restore the tumor suppressor activity of p53. MDMX has growth-promoting activities without p53 or in the presence of mutant p53. Therefore, it is extremely important to study the function of MDMX in tumorigenesis, progression and prognosis. This article mainly reviews the current research progress and mechanism on MDMX function, summarizes known MDMX inhibitors and provides new ideas for the development of more specific and effective MDMX inhibitors for cancer treatment.

SRSF10 facilitates HCC growth and metastasis by suppressing CD8+T cell infiltration and targeting SRSF10 enhances anti-PD-L1 therapy

BACKGROUND AND AIMS

RNA splicing is an essential step in regulating the gene posttranscriptional expression. Serine/arginine-rich splicing factors (SRSFs) are splicing regulators with vital roles in various tumors. Nevertheless, the expression patterns and functions of SRSFs in hepatocellular carcinoma (HCC) are not fully understood.

METHODS

Flow cytometry and immunofluorescent staining were used to determine the CD8+T cell infiltration. Orthotopic HCC model, lung metastasis model, DEN/CCl4 model, Srsf10△hep model, and Srsf10HepOE model were established to evaluate the role of SRSF10 in HCC and the efficacy of combination treatment.

RESULTS

SRSF10 was one of the most survival-relevant genes among SRSF members and was an independent prognostic factor for HCC. SRSF10 facilitated HCC growth and metastasis by suppressing CD8+T cell infiltration. Mechanistically, SRSF10 down-regulated the p53 protein by preventing the exon 6 skipping (exon 7 in mouse) mediated degradation of MDM4 transcript, thus inhibiting CD8+T cell infiltration. Elimination of CD8+T cells or overexpression of MDM4 removed the inhibitory role of SRSF10 knockdown in HCC growth and metastasis. SRSF10 also inhibited the IFNα/γ signaling pathway and promoted the HIF1α-mediated up-regulation of PD-L1 in HCC. Hepatocyte-specific SRSF10 deficiency alleviated the DEN/CCl4-induced HCC progression and metastasis, whereas hepatocyte-specific SRSF10 overexpression deteriorated these effects. Finally, SRSF10 knockdown enhanced the anti-PD-L1-mediated anti-tumor activity.

CONCLUSIONS

SRSF10 promoted HCC growth and metastasis by repressing CD8+T cell infiltration mediated by the MDM4-p53 axis. Furthermore, SRSF10 suppressed the IFNα/γ signaling pathway and induced the HIF1α signal mediated PD-L1 up-regulation. Targeting SRSF10 combined with anti-PD-L1 therapy showed promising efficacy.

Oncogenic activation of EEF1A2 expression: a journey from a putative to an established oncogene

Protein synthesis via translation is a central process involving several essential proteins called translation factors. Although traditionally described as cellular "housekeepers," multiple studies have now supported that protein initiation and elongation factors regulate cell growth, apoptosis, and tumorigenesis. One such translation factor is eukaryotic elongation factor 1 alpha 2 (EEF1A2), a member of the eukaryotic elongation factor family, which has a canonical role in the delivery of aminoacyl-tRNA to the A-site of the ribosome in a guanosine 5'-triphosphate (GTP)-dependent manner. EEF1A2 differs from its closely related isoform, EEF1A1, in tissue distribution. While EEF1A1 is present ubiquitously, EEF1A2 replaces it in specialized tissues. The reason why certain specialized tissues need to essentially switch EEF1A1 expression altogether with EEF1A2 remains to be answered. Abnormal "switch on" of the EEF1A2 gene in normal tissues is witnessed and is seen as a cause of oncogenic transformation in a wide variety of solid tumors. This review presents the journey of finding increased expression of EEF1A2 in multiple cancers, establishing molecular mechanism, and exploring it as a target for cancer therapy. More precisely, we have compiled studies in seven types of cancers that have reported EEF1A2 overexpression. We have discussed the effect of aberrant EEF1A2 expression on the oncogenic properties of cells, signaling pathways, and interacting partners of EEF1A2. More importantly, in the last part, we have discussed the unique potential of EEF1A2 as a therapeutic target. This review article gives an up-to-date account of EEF1A2 as an oncogene and can draw the attention of the scientific community, attracting more research.

Downregulation of stromal syntenin sustains AML development

The crosstalk between cancer and stromal cells plays a critical role in tumor progression. Syntenin is a small scaffold protein involved in the regulation of intercellular communication that is emerging as a target for cancer therapy. Here, we show that certain aggressive forms of acute myeloid leukemia (AML) reduce the expression of syntenin in bone marrow stromal cells (BMSC). Stromal syntenin deficiency, in turn, generates a pro-tumoral microenvironment. From serial transplantations in mice and co-culture experiments, we conclude that syntenin-deficient BMSC stimulate AML aggressiveness by promoting AML cell survival and protein synthesis. This pro-tumoral activity is supported by increased expression of endoglin, a classical marker of BMSC, which in trans stimulates AML translational activity. In short, our study reveals a vicious signaling loop potentially at the heart of AML-stroma crosstalk and unsuspected tumor-suppressive effects of syntenin that need to be considered during systemic targeting of syntenin in cancer therapy.

Inflammatory cytokine-regulated LNCPTCTS suppresses thyroid cancer progression via enhancing Snail nuclear export

Lymph node metastases are commonly observed in diverse malignancies where they promote cancer progression and poor outcomes, although the molecular basis is incompletely understood. Thyroid cancer is the most prevalent endocrine neoplasm characterized by high frequency of lymph node metastases. Here, we uncover an inflammatory cytokines-controlled epigenetic program during thyroid cancer progression. LNCPTCTS acts as a novel tumor suppressive lncRNA with remarkably decreased expression in thyroid cancer specimens, especially in metastatic lymph nodes. Inflammatory cytokines TNFα or CXCL10, which are released from tumor microenvironment (TME), impair binding capabilities of the transcription factor (TF) EGR1 to the LNCPTCTS promoter and reduce the lncRNA expression in cells. Notably, LNCPTCTS binds to eEF1A2 protein and facilitates the interaction between eEF1A2 and Snail, which promotes Snail nucleus export via the RanGTP-Exp5-aa-tRNA-eEF1A2 complex. Loss of LNCPTCTS in tumors leads to accumulation of Snail in the nucleus, suppressed transcription of E-cadherin and PEBP1, reduced E-cadherin and PEBP1 protein levels, and activated epithelial-mesenchymal transition and MAPK signaling. Our results reveal what we believe to be a novel paradigm between TME and epigenetic reprogram in cancer cells which drives lymph node metastases, therefore illuminating the suitability of LNCPTCTS as a targetable vulnerability in thyroid cancer.

Comparative analyses of dynamic transcriptome profiles highlight key response genes and dominant isoforms for muscle development and growth in chicken

BACKGROUND

Modern breeding strategies have resulted in significant differences in muscle mass between indigenous chicken and specialized broiler. However, the molecular regulatory mechanisms that underlie these differences remain elusive. The aim of this study was to identify key genes and regulatory mechanisms underlying differences in breast muscle development between indigenous chicken and specialized broiler.

RESULTS

Two time-series RNA-sequencing profiles of breast muscles were generated from commercial Arbor Acres (AA) broiler (fast-growing) and Chinese indigenous Lushi blue-shelled-egg (LS) chicken (slow-growing) at embryonic days 10, 14, and 18, and post-hatching day 1 and weeks 1, 3, and 5. Principal component analysis of the transcriptome profiles showed that the top four principal components accounted for more than 80% of the total variance in each breed. The developmental axes between the AA and LS chicken overlapped at the embryonic stages but gradually separated at the adult stages. Integrative investigation of differentially-expressed transcripts contained in the top four principal components identified 44 genes that formed a molecular network associated with differences in breast muscle mass between the two breeds. In addition, alternative splicing analysis revealed that genes with multiple isoforms always had one dominant transcript that exhibited a significantly higher expression level than the others. Among the 44 genes, the TNFRSF6B gene, a mediator of signal transduction pathways and cell proliferation, harbored two alternative splicing isoforms, TNFRSF6B-X1 and TNFRSF6B-X2. TNFRSF6B-X1 was the dominant isoform in both breeds before the age of one week. A switching event of the dominant isoform occurred at one week of age, resulting in TNFRSF6B-X2 being the dominant isoform in AA broiler, whereas TNFRSF6B-X1 remained the dominant isoform in LS chicken. Gain-of-function assays demonstrated that both isoforms promoted the proliferation of chicken primary myoblasts, but only TNFRSF6B-X2 augmented the differentiation and intracellular protein content of chicken primary myoblasts.

CONCLUSIONS

For the first time, we identified several key genes and dominant isoforms that may be responsible for differences in muscle mass between slow-growing indigenous chicken and fast-growing commercial broiler. These findings provide new insights into the regulatory mechanisms underlying breast muscle development in chicken.

GBAP1 functions as a tumor promotor in hepatocellular carcinoma via the PI3K/AKT pathway

Hepatocellular carcinoma (HCC) is common worldwide, and novel therapeutic targets and biomarkers are needed to improve outcomes. In this study, bioinformatics analyses combined with in vitro and in vivo assays were used to identify the potential therapeutic targets. Differentially expressed genes (DEG) in HCC were identified by the intersection between The Cancer Genome Atlas and International Cancer Genome Consortium data. The DEGs were evaluated by a gene set enrichment analysis as well as Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. A protein interaction network, univariate Cox regression, and Lasso regression were used to screen out hub genes correlated with survival. Increased expression of the long noncoding RNA GBAP1 in HCC was confirmed in additional datasets and its biological function was evaluated in HCC cell lines and nude mice. Among 121 DEGs, GBAP1 and PRC1 were identified as hub genes with significant prognostic value. Overexpression of GBAP1 in HCC was confirmed in 21 paired clinical tissues and liver cancer or normal cell lines. The inhibition of GBAP1 expression reduced HCC cell proliferation and promoted apoptosis by inactivating the PI3K/AKT pathway in vitro and in vivo. Therefore, GBAP1 has a pro-oncogenic function in HCC and is a candidate prognostic biomarker and therapeutic target.

eEF1A2 siRNA Suppresses MPP+-Induced Activation of Akt and mTOR and Potentiates Caspase-3 Activation in a Parkinson’s Disease Model

The tissue-specific protein eEF1A2 has been linked to the development of neurological disorders. The role of eEF1A2 in the pathogenesis of Parkinson’s disease (PD) has yet to be investigated. The aim of this study was to determine the potential neuroprotective effects of eEF1A2 in an MPP+ model of PD. Differentiated SH-SY5Y cells were transfected with eEF1A2 siRNA, followed by MPP+ exposure. The expression of p-Akt1 and p-mTORC1 was determined using Western blotting. The expression of p53, Bax, Bcl-2, and caspase-3 was evaluated using qRT-PCR. Cleaved caspase-3 levels and Annexin V/propidium iodide flow cytometry were used to determine apoptosis. The effects of PI3K inhibition were examined. The results showed that eEF1A2 siRNA significantly reduced the eEF1A2 expression induced by MPP+. MPP+ treatment activated Akt1 and mTORC1; however, eEF1A2 knockdown suppressed this activation. In eEF1A2-knockdown cells, MPP+ treatment increased the expression of p53 and caspase-3 mRNA levels as well as increased apoptotic cell death when compared to MPP+ treatment alone. In cells exposed to MPP+, upstream inhibition of the Akt/mTOR pathway, by either LY294002 or wortmannin, inhibited the phosphorylation of Akt1 and mTORC1. Both PI3K inhibitors increased eEF1A2 expression in cells, whether or not they were also treated with MPP+. In conclusion, eEF1A2 may function as a neuroprotective factor against MPP+, in part by regulating the Akt/mTOR pathway upstream.

Anticancer Small-Molecule Agents Targeting Eukaryotic Elongation Factor 1A: State of the Art

Eukaryotic elongation factor 1A (eEF1A) canonically delivers amino acyl tRNA to the ribosomal A site during the elongation stage of protein biosynthesis. Yet paradoxically, the oncogenic nature of this instrumental protein has long been recognized. Consistently, eEF1A has proven to be targeted by a wide assortment of small molecules with excellent anticancer activity, among which plitidepsin has been granted approval for the treatment of multiple myeloma. Meanwhile, metarrestin is currently under clinical development for metastatic cancers. Bearing these exciting advances in mind, it would be desirable to present a systematic up-to-date account of the title topic, which, to the best of our knowledge, has thus far been unavailable in the literature. The present review summarizes recent advances in eEF1A-targeting anticancer agents, both naturally occurring and synthetically crafted, with regard to their discovery or design, target identification, structure–activity relationship, and mode of action. Their structural diversity and differential eEF1A-targeting mechanisms warrant continuing research in pursuit of curing eEF1A-driven malignancy.

Emerging role of aging in the progression of NAFLD to HCC

With the aging of global population, the incidence of nonalcoholic fatty liver disease (NAFLD) has surged in recent decades. NAFLD is a multifactorial disease that follows a progressive course, ranging from simple fatty liver, nonalcoholic steatohepatitis (NASH) to liver cirrhosis and hepatocellular carcinoma (HCC). It is well established that aging induces pathological changes in liver and potentiates the occurrence and progression of NAFLD, HCC and other age-related liver diseases. Studies of senescent cells also indicate a pivotal engagement in the development of NAFLD via diverse mechanisms. Moreover, nicotinamide adenine dinucleotide (NAD⁺), silence information regulator protein family (sirtuins), and mechanistic target of rapamycin (mTOR) are three vital and broadly studied targets involved in aging process and NAFLD. Nevertheless, the crucial role of these aging-associated factors in aging-related NAFLD remains underestimated. Here, we reviewed the current research on the roles of aging, cellular senescence and three aging-related factors in the evolution of NAFLD to HCC, aiming at inspiring promising therapeutic targets for aging-related NAFLD and its progression.

Mechanism of Tao Hong Decoction in the treatment of atherosclerosis based on network pharmacology and experimental validation

Background

Atherosclerosis (AS) has long been recognized as a cardiovascular disease and stroke risk factor. A well-known traditional Chinese medicine prescription, Tao Hong decoction (THD), has been proven effective in treating AS, but its mechanism of action is still unclear.

Objective

To assess the effects, explore THD's primary mechanism for treating AS, and provide a basis for rational interpretation of its prescription compatibility.

Methods

Based on network pharmacology, we evaluated the mechanism of THD on AS by data analysis, target prediction, the construction of PPI networks, and GO and KEGG analysis. AutoDockTools software to conduct Molecular docking. Then UPLC-Q-TOF-MS was used to identify significant constituents of THD. Furthermore, an AS mice model was constructed and intervened with THD. Immunofluorescence, RT-qPCR, and Western blot were used to verify the critical targets in animal experiments.

Results

The network pharmacology results indicate that eight core targets and seven core active ingredients play an essential role in this process. The GO and KEGG analysis results suggested that the mechanism is mainly involved in Fluid shear stress and atherosclerosis and Lipid and atherosclerosis. The molecular docking results indicate a generally strong affinity. The animal experiment showed that THD reduced plaque area, increased plaque stability, and decreased the levels of inflammatory cytokines (NF-κB, IL-1α, TNF-α, IL-6, IL-18, IL-1β) in high-fat diet -induced ApoE-/-mice. Decreased levels of PTGS2, HIF-1α, VEGFA, VEGFC, FLT-4, and the phosphorylation of PI3K, AKT, and p38 were detected in the THD-treated group.

Conclusion

THD plays a vital role in treating AS with multiple targets and pathways. Angiogenesis regulation, oxidative stress regulation, and immunity regulation consist of the crucial regulation cores in the mechanism. This study identified essential genes and pathways associated with the prognosis and pathogenesis of AS from new insights, demonstrating a feasible method for researching THD's chemical basis and pharmacology.

The progress of protein synthesis factors eIFs, eEFs and eRFs in inflammatory bowel disease and colorectal cancer pathogenesis

Colorectal diseases are threatening human health, especially inflammatory bowel disease (IBD) and colorectal cancer (CRC). IBD is a group of chronic, recurrent and incurable disease, which may affect the entire gastrointestinal tract, increasing the risk of CRC. Eukaryotic gene expression is a complicated process, which is mainly regulated at the level of gene transcription and mRNA translation. Protein translation in tissue is associated with a sequence of steps, including initiation, elongation, termination and recycling. Abnormal regulation of gene expression is the key to the pathogenesis of CRC. In the early stages of cancer, it is vital to identify new diagnostic and therapeutic targets and biomarkers. This review presented current knowledge on aberrant expression of eIFs, eEFs and eRFs in colorectal diseases. The current findings of protein synthesis on colorectal pathogenesis showed that eIFs, eEFs and eRFs may be potential targets for CRC treatment.

The complexity of p53-mediated metabolic regulation in tumor suppression

Although the classic activities of p53 including induction of cell-cycle arrest, senescence, and apoptosis are well accepted as critical barriers to cancer development, accumulating evidence suggests that loss of these classic activities is not sufficient to abrogate the tumor suppression activity of p53. Numerous studies suggest that metabolic regulation contributes to tumor suppression, but the mechanisms by which it does so are not completely understood. Cancer cells rewire cellular metabolism to meet the energetic and substrate demands of tumor development. It is well established that p53 suppresses glycolysis and promotes mitochondrial oxidative phosphorylation through a number of downstream targets against the Warburg effect. The role of p53-mediated metabolic regulation in tumor suppression is complexed by its function to promote both cell survival and cell death under different physiological settings. Indeed, p53 can regulate both pro-oxidant and antioxidant target genes for complete opposite effects. In this review, we will summarize the roles of p53 in the regulation of glucose, lipid, amino acid, nucleotide, iron metabolism, and ROS production. We will highlight the mechanisms underlying p53-mediated ferroptosis, AKT/mTOR signaling as well as autophagy and discuss the complexity of p53-metabolic regulation in tumor development.

Overexpressing eukaryotic elongation factor 1 alpha (eEF1A) proteins to promote corticospinal axon repair after injury

Although protein synthesis is hypothesized to have a pivotal role in axonal repair after central nervous system (CNS) injury, the role of core components of the protein synthesis machinery has not been examined. Notably, some elongation factors possess non-canonical functions that may further impact axonal repair. Here, we examined whether overexpressing eukaryotic elongation factor 1 alpha (eEF1A) proteins enhances the collateral sprouting of corticospinal tract (CST) neurons after unilateral pyramidotomy, along with the underlying molecular mechanisms. We found that overexpressing eEF1A proteins in CST neurons increased the levels of pS6, an indicator for mTOR activity, but not pSTAT3 and pAKT levels, in neuronal somas. Strikingly, overexpressing eEF1A2 alone, but neither eEF1A1 alone nor both factors simultaneously, increased protein synthesis and actin rearrangement in CST neurons. While eEF1A1 overexpression only slightly enhanced CST sprouting after pyramidotomy, eEF1A2 overexpression substantially enhanced this sprouting. Surprisingly, co-overexpression of both eEF1A1 and eEF1A2 led to a sprouting phenotype similar to wild-type controls, suggesting an antagonistic effect of overexpressing both proteins. These data provide the first evidence that overexpressing a core component of the translation machinery, eEF1A2, enhances CST sprouting, likely by a combination of increased protein synthesis, mTOR signaling and actin cytoskeleton rearrangement.

The Cross Talk Between p53 and mTOR Pathways in Response to Physiological and Genotoxic Stresses

The tumor suppressor p53 is activated upon multiple cellular stresses, including DNA damage, oncogene activation, ribosomal stress, and hypoxia, to induce cell cycle arrest, apoptosis, and senescence. Mammalian target of rapamycin (mTOR), an evolutionarily conserved serine/threonine protein kinase, serves as a central regulator of cell growth, proliferation, and survival by coordinating nutrients, energy, growth factors, and oxygen levels. p53 dysfunction and mTOR pathway hyperactivation are hallmarks of human cancer. The balance between response to stresses or commitment to cell proliferation and survival is governed by various regulatory loops between the p53 and mTOR pathways. In this review, we first briefly introduce the tumor suppressor p53 and then describe the upstream regulators and downstream effectors of the mTOR pathway. Next, we discuss the role of p53 in regulating the mTOR pathway through its transcriptional and non-transcriptional effects. We further describe the complicated role of the mTOR pathway in modulating p53 activity. Finally, we discuss the current knowledge and future perspectives on the coordinated regulation of the p53 and mTOR pathways.

The Expression and Function of Circadian Rhythm Genes in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is among the most common and lethal form of cancer worldwide. However, its diagnosis and treatment are still dissatisfactory, due to limitations in the understanding of its pathogenic mechanism. Therefore, it is important to elucidate the molecular mechanisms and identify novel therapeutic targets for HCC. Circadian rhythm-related genes control a variety of biological processes. These genes play pivotal roles in the initiation and progression of HCC and are potential diagnostic markers and therapeutic targets. This review gives an update on the research progress of circadian rhythms, their effects on the initiation, progression, and prognosis of HCC, in a bid to provide new insights for the research and treatment of HCC.

Neuroblastoma Cell Death Induced by eEF1A2 Knockdown Is Possibly Mediated by the Inhibition of Akt and mTOR Phosphorylation

Background The protein kinase B/mammalian target of the rapamycin (Akt/mTOR) pathway is one of the most potent prosurvival signaling cascades that is constitutively active in neuroblastoma. The eukaryotic translation elongation factor-1, alpha-2 (eEF1A2) protein has been found to activate the Akt/mTOR pathway. However, there is a lack of data on the role of eEF1A2 in neuroblastoma. The present study investigated the effect of eEF1A2 silencing on the viability of neuroblastoma cells and its possible signaling. Materials and Methods: Human SH-SY5Y neuroblastoma cells were transfected with small interfering RNA (siRNA) against eEF1A2. After 48 h of transfection, cell viability was assessed using an MTT assay. The mRNA expression of p53, Bax, Bcl-2, caspase-3 and members of the phosphoinositide 3-kinases (PI3K)/Akt/mTOR pathway was determined using quantitative real-time RT-PCR (qRT-PCR). The protein expression of Akt and mTOR was measured using Western blot analysis. Results: eEF1A2 knockdown significantly decreased the viability of neuroblastoma cells. No significant changes were observed on the expression of p53, Bax/Bcl-2 ratio, and caspase-3 mRNAs; however, the upregulated trends were noted for the p53 and Bax/Bcl-2 ratio. eEF1A2 knockdown significantly inhibited the phosphorylation of both Akt and mTOR. Almost all of the class I (PIK3CA, PIK3CB, and PIK3CD) and all of the class II PI3K genes were slightly increased in tumor cells with eEF1A2 knockdown. In addition, a slightly decreased expression of the Akt2, mTORC1, and mTORC2 was observed. Conclusion: eEF1A2 knockdown induced neuroblastoma cell death, in part through the inhibition of Akt and mTOR, suggesting a potential role of eEF1A2 as a molecular target for neuroblastoma therapy.

Autophagy Promotes the Survival of Adipose Mesenchymal Stem/Stromal Cells and Enhances Their Therapeutic Effects in Cisplatin-Induced Liver Injury via Modulating TGF-β1/Smad and PI3K/AKT Signaling Pathways

Autophagy is a key metabolic process where cells can recycle its proteins and organelles to regenerate its own cellular building blocks. Chemotherapy is indispensable for cancer treatment but associated with various side-effects, including organ damage. Stem cell-based therapy is a promising approach for reducing chemotherapeutic side effects, however, one of its main culprits is the poor survival of transplanted stem cells in damaged tissues. Here, we aimed to test the effects of activating autophagy in adipose-derived mesenchymal stem/stromal cells (ADSCs) on the survival of ADSCs, and their therapeutic value in cisplatin-induced liver injury model. Autophagy was activated in ADSCs by rapamycin (50 nM/L) for two hours before transplantation and were compared to non-preconditioned ADSCs. Rapamycin preconditioning resulted in activated autophagy and improved survival of ADSCs achieved by increased autophagosomes, upregulated autophagy-specific LC3-II gene, decreased protein degradation/ubiquitination by downregulated p62 gene, downregulated mTOR gene, and finally, upregulated antiapoptotic BCL-2 gene. In addition, autophagic ADSCs transplantation in the cisplatin liver injury model, liver biochemical parameters (AST, ALT and albumin), lipid peroxidation (MDA), antioxidant profile (SOD and GPX) and histopathological picture were improved, approaching near-normal conditions. These promising autophagic ADSCs effects were achieved by modulation of components in TGF-β1/Smad and PI3K-AKT signaling pathways, besides reducing NF-κB gene expression (marker for inflammation), reducing TGF-β1 levels (marker for fibrosis) and increasing SDF-1 levels (liver regeneration marker) in liver. Therefore, current results highlight the importance of autophagy in augmenting the therapeutic potential of stem cell therapy in alleviating cisplatin-associated liver damage and opens the path for improved cell-based therapies, in general, and with chemotherapeutics, in particular.

FAM83G promotes proliferation, invasion, and metastasis by regulating PI3K/AKT signaling in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) has received extensive attention from clinical and scientific researchers due to its high incidence and refractory nature. Searching for HCC prognostic markers and gene therapy targets are key research efforts. The FAM83 protein family has been reported to promote tumor growth and metastasis in a variety of tumors, and many of its members are closely related to HCC. Multiple public databases showed that FAM83G is highly expressed in HCC patients and is associated with poor prognosis, but there is currently no relevant research evidence to verify its exact role in HCC. Through clinical data analysis, we found that increased expression of FAM83G is associated with early HCC metastasis and a high recurrence rate and indicates a poor survival rate. Both in vivo and in vitro experiments confirmed that FAM83G overexpression significantly promoted the proliferation, migration, and invasion of HCC cells, while inhibiting its expression reversed the above results. Mechanistic analysis indicated that FAM83G overexpression was accompanied by over-activation of PI3K/AKT pathway signaling, a combined increase of Cyclin D1 protein and decrease of p21 protein, and increased expression of EMT-related signal, which was manifested in the decrease of E-cadherin and the increase of N-cadherin and snail. Finally, we found that FAM83G activated PI3K/AKT signaling by directly binding with the PI3K-p85 subunit to promote its phosphorylation. In conclusion, FAM83G, as a tumor-promoting factor, can predict the poor prognosis of HCC patients and can significantly promote the proliferation, invasion, and migration of HCC cells by stimulating the PI3K/AKT signaling pathway and related downstream signals.

Role of PI3K/AKT Signaling Pathway in Nucleus Pulposus Cells

OBJECTIVE

To investigate the role of PI3K/AKT signaling pathway in nucleus pulposus (NP) cells.

METHODS

Nucleus pulposus (NP) cells were isolated from SD rat, and thereafter, passage three (P3) NP cells were divided into the following experimental groups: control, PI3K/AKT agonist IGF-1 (25 ng/ml, 50 ng/ml, and 100 ng/ml), and PI3K/AKT inhibitor LY294002 (5 μM, 10 μM, and 20 μM). Flow cytometry and BrdU cell proliferation assays were performed to assess apoptosis and the proliferation rate of NP cells. Western blot analysis was performed to examine the protein expression level of Col II, Col X, Aggrecan, and MMP13.

RESULTS

PI3K/AKT inhibitor LY294002 increased the rate of apoptosis in NP cells when compared to the control and decreased the proliferation rate when compared to control. Moreover, LY294002 decreased the protein expression level of Col-II and Aggrecan in NP cells. At the same time, LY294002 increased the protein expression level of MMP13 and Col-X in NP cells. Through activating PI3K/AKT, IGF-1 increased the proliferation rate when compared to control and decreased the rate of apoptosis when compared to control. Additionally, IGF-1 decreased the protein expression level of MMP13 and Col-X and increased Col-II and Aggrecan in NP cells.

CONCLUSION

The inhibition of PI3K/AKT signaling pathway accelerated the apoptosis of NP cells and facilitated the extracellular matrix degradation. However, the activation of PI3K/AKT pathway partly prevented the NP cell from apoptosis and promoted their proliferation. Meanwhile, its activation also delayed the loss of extracellular matrix.

MDM4 inhibition: a novel therapeutic strategy to reactivate p53 in hepatoblastoma

Hepatoblastoma (HB) is the most common pediatric liver malignancy. High-risk patients have poor survival, and current chemotherapies are associated with significant toxicities. Targeted therapies are needed to improve outcomes and patient quality of life. Most HB cases are TP53 wild-type; therefore, we hypothesized that targeting the p53 regulator Murine double minute 4 (MDM4) to reactivate p53 signaling may show efficacy. MDM4 expression was elevated in HB patient samples, and increased expression was strongly correlated with decreased expression of p53 target genes. Treatment with NSC207895 (XI-006), which inhibits MDM4 expression, or ATSP-7041, a stapled peptide dual inhibitor of MDM2 and MDM4, showed significant cytotoxic and antiproliferative effects in HB cells. Similar phenotypes were seen with short hairpin RNA (shRNA)-mediated inhibition of MDM4. Both NSC207895 and ATSP-7041 caused significant upregulation of p53 targets in HB cells. Knocking-down TP53 with shRNA or overexpressing MDM4 led to resistance to NSC207895-mediated cytotoxicity, suggesting that this phenotype is dependent on the MDM4-p53 axis. MDM4 inhibition also showed efficacy in a murine model of HB with significantly decreased tumor weight and increased apoptosis observed in the treatment group. This study demonstrates that inhibition of MDM4 is efficacious in HB by upregulating p53 tumor suppressor signaling.

Hepatitis B Virus DNA Polymerase Displays an Anti-Apoptotic Effect by Interacting with Elongation Factor-1 Alpha-2 in Hepatoma Cells

Hepatitis B virus (HBV) genome P-encoded protein HBV DNA polymerase (Pol) has long been known as a reverse transcriptase during HBV replication. In this study, we investigated the impact of HBV Pol on host cellular processes, mainly apoptosis, and the underlying mechanisms. We showed a marked reduction in apoptotic rates in the HBV Pol-expressed HepG2 cells compared to controls. Moreover, a series of assays, i.e., yeast two-hybrid, GST pull-down, co-immunoprecipitation, and confocal laser scanning microscopy, identified the host factor eEF1A2 to be associated with HBV Pol. Furthermore, knockdown of eEF1A2 gene by siRNA abrogated the HBV Pol-mediated anti-apoptotic effect with apoptosis induced by endoplasmatic reticulum (ER) stress-inducer thapsigargin (TG), thus suggesting that the host factor eEF1A2 is essential for HBV Pol's anti-apoptosis properties. Our findings have revealed a novel role for HBV Pol in its modulation of apoptosis through integrating with eEF1A2.

Serum Response Factor (SRF) Drives the Transcriptional Upregulation of the MDM4 Oncogene in HCC

Different molecular mechanisms support the overexpression of the mouse double minute homolog 4 (MDM4), a functional p53 inhibitor, in human hepatocellular carcinoma (HCC). However, the transcription factors (TFs) leading to its transcriptional upregulation remain unknown. Following promoter and gene expression analyses, putative TFs were investigated using gene-specific siRNAs, cDNAs, luciferase reporter assays, chromatin immunoprecipitation, and XI-011 drug treatment in vitro. Additionally, MDM4 expression was investigated in SRF-VP16iHep transgenic mice. We observed a copy-number-independent upregulation of MDM4 in human HCCs. Serum response factor (SRF), ELK1 and ELK4 were identified as TFs activating MDM4 transcription. While SRF was constitutively detected in TF complexes at the MDM4 promoter, presence of ELK1 and ELK4 was cell-type dependent. Furthermore, MDM4 was upregulated in SRF-VP16-driven murine liver tumors. The pharmacological inhibitor XI-011 exhibited anti-MDM4 activity by downregulating the TFs driving MDM4 transcription, which decreased HCC cell viability and increased apoptosis. In conclusion, SRF drives transcriptional MDM4 upregulation in HCC, acting in concert with either ELK1 or ELK4. The transcriptional regulation of MDM4 may be a promising target for precision oncology of human HCC, as XI-011 treatment exerts anti-MDM4 activity independent from the MDM4 copy number and the p53 status.

Effect of activation of the Akt/mTOR signaling pathway by EEF1A2 on the biological behavior of osteosarcoma

Background

Osteosarcoma (OS) is a common bone cancer in children and adolescents which causes a large number of cancer-related deaths. Eukaryotic Translation Elongation Factor 1 Alpha 2 (EEF1A2) has been revealed to have carcinogenic properties and promote tumor progression in many cancers. We want to investigate the biological function and mechanism of EEF1A2 in OS.

Methods

The expression of EEF1A2 in OS was investigated using the Gene Expression Omnibus (GEO) database and quantitative reverse transcription polymerase chain reaction (qRT-PCR). The biological function of EEF1A2 in OS was studied using cell counting kit-8 (CCK8) assay, 5-ethynyl-2’-deoxyuridine (EdU) assay, Transwell assay, and OS of xenograft nude mice model. Real-time fluorescence quantitative PCR was used to detect the expression level of EEF1A2 mRNA in OS tissues and cell lines. Western blot was used to detect the phosphorylation level of Akt and mTOR

Results

There was high expression of EEF1A2 in OS, which was closely related to the Enneking stage and tumor size of OS. In vitro, EEF1A2 promoted the proliferation, migration, and invasion of OS cells; in vivo, EEF1A2 promoted the growth of OS tumors. The mechanism study showed that EEF1A2 can promote protein kinase B (Akt) and mammalian target of rapamycin (mTOR) phosphorylation, thereby activating the Akt/mTOR signaling pathway in OS.

Conclusion

There is high expression of EEF1A2 in OS, which can promote the proliferation, migration, and invasion of OS cells in vitro and the growth of OS tumors in vivo via activation of the Akt/mTOR signaling pathway.

Ultrasound-Targeted Microbubble Destruction Mediated si-CyclinD1 Inhibits the Development of Hepatocellular Carcinoma via Suppression of PI3K/AKT Signaling Pathway

Background and Aim

In our study, we aimed to investigate the effect of ultrasound-targeted microbubble destruction (UTMD)mediated si-CyclinD1 (CCND1) on the growth of hepatocellular carcinoma (HCC) cells.

Patients and Methods

Bioinformatics analysis was performed to detect the difference of CCND1 expression of HCC and normal liver tissues. After treatment with UTMDmediated si-CCND1, the growth and apoptosis of HepG2 cells were detected by flow cytometry, MTT, EdU staining, colony formation assay, Hoechst 33,258 staining and Western blot analysis. The growth of HepG2 cells in vivo was also studied via xenograft tumor in nude mice.

Results

CCND1 was highly expressed in HCC tissues and HCC cell lines. UTMDmediated si-CCND1 could inhibit the growth of HepG2 cells and promote apoptosis via suppression of the PI3K/AKT signaling pathway. UTMDmediated si-CCND1 could also suppress the growth of HepG2 cells in vivo.

Conclusion

Our study provided evidence that UTMDmediated si-CCND1 could inhibit the growth of HepG2 cells and promote apoptosis via suppression of the PI3K/AKT signaling pathway.

The multiple roles of deubiquitinases in liver cancer

Primary liver cancer ranks the second leading cause of death associated with cancer in the world and therefore a major public health challenge. The mortality rates of liver cancer has been increasing during the past decades with the reality that the alternative therapeutic drugs are not available. Although growing numbers of proteins involved in liver cancer progression have been identified, many of these are not suitable drug targets, which hinders the development of new drugs to cure liver cancer. It is in urgent demand that novel therapeutic approaches should be explored. Deubiquitinases (DUBs), specifically removing ubiquitin chains from the target protein, have showed vital roles for protein homeostasis and quality control by rigidly regulating the balance between ubiquitination and deubiquitination in normal physiology. Recent studies have revealed deregulation or dysfunction of DUBs always associates with cancer and other diseases. Targeting certain DUBs, leading to degradation or loss function of the key oncoproteins, including undruggable ones, seems to provide a potential therapy for cancer patients. In liver cancer, numberous of DUBs are demonstrated to participate in hepatocarcinogenesis, metastasis and so on. Depending on the substrates, some DUBs may suppress liver cancers while others promote. In this review, we primarily summarize the roles of DUBs in liver tumors, and illustrate opportunities for the application of targeting DUBs for cancer therapy.

Validation of miR-20a as a Tumor Suppressor Gene in Liver Carcinoma Using Hepatocyte-Specific Hyperactive piggyBac Transposons

We established a semi-high-throughput in vivo screening platform using hyperactive piggyBac (hyPB) transposons (designated as PB-miR) to identify microRNAs (miRs) that inhibit hepatocellular carcinoma (HCC) development in vivo, following miR overexpression in hepatocytes. PB-miRs encoding six different miRs from the miR-17-92 cluster and nine miRs from outside this cluster were transfected into mouse livers that were chemically induced to develop HCC. In this slow-onset HCC model, miR-20a significantly inhibited HCC. Next, we developed a more aggressive HCC model by overexpression of oncogenic Harvey rat sarcoma viral oncogene homolog (HRASG12V) and c-MYC oncogenes that accelerated HCC development after only 6 weeks. The tumor suppressor effect of miR-20a could be demonstrated even in this rapid-onset HRASG12V/c-MYC HCC model, consistent with significantly prolonged survival and decreased HCC tumor burden. Comprehensive RNA expression profiling of 95 selected genes typically associated with HCC development revealed differentially expressed genes and functional pathways that were associated with miR-20a-mediated HCC suppression. To our knowledge, this is the first study establishing a direct causal relationship between miR-20a overexpression and liver cancer inhibition in vivo. Moreover, these results demonstrate that hepatocyte-specific hyPB transposons are an efficient platform to screen and identify miRs that affect overall survival and HCC tumor regression.

SNX16 activates c-Myc signaling by inhibiting ubiquitin-mediated proteasomal degradation of eEF1A2 in colorectal cancer development

Sorting nexin 16 (SNX16), a member of the sorting nexin family, has been implicated in tumor development. However, the function of SNX16 has not yet been investigated in colorectal cancer (CRC). Here, we showed that SNX16 expression was significantly upregulated in CRC tissues compared with normal counterparts. Upregulated mRNA levels of SNX16 predicted poor survival of CRC patients. Functional experiments showed that SNX16 could promote CRC cells growth both in vitro and in vivo. Knockdown of SNX16 induced cell cycle arrest and apoptosis, whereas ectopic overexpression of SNX16 had the opposite effects. Mechanistically, SNX16‐eukaryotic translation elongation factor 1A2 (eEF1A2) interaction could inhibit the degradation and ubiquitination of eEF1A2, followed by activation of downstream c‐Myc signaling. Our study unveiled that the SNX16/eEF1A2/c‐Myc signaling axis could promote colorectal tumorigenesis and SNX16 might potentially serve as a novel biomarker for the diagnosis and an intervention of CRC.

NCAPG Promotes The Proliferation Of Hepatocellular Carcinoma Through PI3K/AKT Signaling

Purpose

Studies show that high expression of non-SMC condensin I complex subunit G (NCAPG) is associated with many tumors. In this study, we explore the mechanism by which NCAPG promotes proliferation in hepatocellular carcinoma (HCC).

Patients and methods

Liver cancer and paracancerous tissue specimens of 90 HCC patients were collected, and expression levels of NCAPG in these tissues and cell lines were evaluated by Western blotting and immunohistochemistry. HCC cells were transfected with siRNAs and plasmids, and pathway activators or inhibitors were added. The 5-ethynyl-2ʹ-deoxyuridine (EdU) proliferation assay was used to measure cell proliferation. Flow cytometry was used to evaluate cell apoptosis. Western blot assays were performed as a standard procedure to detect total protein expression. Treated HCC cells were subcutaneously injected into nude mice.

Results

Analysis using the Oncomine database showed that NCAPG was upregulated in HCC and immunohistochemistry and Western blot assays showed it was upregulated in both HCC tissues and HCC cell lines. The overexpression of NCAPG could promote HCC cell proliferation and reduce HCC cell apoptosis. More importantly, RNA-sequencing analysis predicted that NCAPG plays a role in the HCC via PI3K-AKT signaling pathway. The PI3K/AKT/FOXO4 pathway was aberrantly activated, and the expressions of apoptosis-related protein were altered when NCAPG was overexpressed or silenced both in vitro and in vivo. LY294002, a PI3K inhibitor, could eliminate the NCAPG role of promoting HCC cell proliferation and reducing HCC cell apoptosis, while 740Y-P, a PI3K activator, contributed to the opposite effect.

Conclusion

NCAPG functions as an oncogene in HCC and plays a role in promoting cell proliferation and antiapoptosis through activating the PI3K/AKT/FOXO4 pathway.

MicroRNA-101 modulates cisplatin chemoresistance in liver cancer cells via the DNA-PKcs signaling pathway

Due to the high incidence of liver cancer, chemoradiotherapy and prognosis of liver cancer are a primary focus of medical research. microRNAs (miRNAs/miRs) serve crucial roles in resistance to chemotherapy and radiotherapy. The aim of the present study was to investigate the effects of miR-101 on the chemotherapeutic efficacy of cisplatin (CDDP) in liver cancer. First, human liver cancer cells (HepG2) were transfected with a miR-101 mimic or miR-101 inhibitor to bidirectionally regulate the expression of miR-101. Cell proliferation, apoptosis, intracellular reactive oxygen species and comet assay results indicated that the upregulation of miR-101 sensitized HepG2 cells to CDDP, and downregulation of miR-101 reduced chemosensitivity. A xenograft mouse model further confirmed that miR-101 overexpression increased CDDP sensitivity in liver cancer. Luciferase reporter and western blotting assays demonstrated that transfection of the miR-101 mimic markedly reduced activity of the DNA-dependent protein kinase catalytic subunit/protein kinase B/mammalian target of rapamycin (DNA-PKcs/Akt/mTOR) pathway and increased expression of apoptotic protein caspase 3, which is induced by CDDP treatment. By contrast, miR-101 inhibitors partially reversed these changes. Moreover, the miR-101 mimic suppressed activity of the nuclear factor-κB (NF-κB) pathway, leading to increased susceptibility of HepG2 cells to chemotherapeutic agents. In conclusion, miR-101 overexpression augmented cytotoxicity and reduced chemoresistance to CDDP in HepG2 cells, and this was associated with negative regulation of DNA-PKcs/Akt/NF-κB signaling.

Formiminotransferase Cyclodeaminase Suppresses Hepatocellular Carcinoma by Modulating Cell Apoptosis, DNA Damage, and Phosphatidylinositol 3-Kinases (PI3K)/Akt Signaling Pathway

Background

Formiminotransferase cyclodeaminase (FTCD) is a candidate tumor suppressor gene in hepatocellular carcinoma (HCC). However, the mechanism for reduced expression of FTCD and its functional role in HCC remains unclear. In this study, we explored the biological functions of FTCD in HCC.

Material/Methods

The expression and clinical correlation of FTCD in HCC tissue were analyzed using TCGA (The Cancer Genome Atlas) and a cohort of 60 HCC patients. The MEXPRESS platform was accessed to identify the methylation level in promoter region FTCD. CCK-8 assay and flow cytometry analysis were used to explore the proliferation, cell apoptosis proportion, and DNA damage in HCC cells with FTCD overexpression. Western blot analysis was performed to identify the downstream target of FTCD.

Results

FTCD is significantly downregulated in HCC tissues and cell lines. Low FTCD expression is correlated with a poor prognosis (P<0.001) and an aggressive tumor phenotype, including AFP levels (P=0.009), tumor size (P=0.013), vascular invasion (P=0.001), BCLC stage (P=0.024), and pTNM stage (P<0.001). Bioinformatics analysis indicated promoter hypermethylation can result in decreased expression of FTCD. FTCD overexpression suppressed cell proliferation by promoting DNA damage and inducing cell apoptosis in HCC cells. FTCD overexpression resulted in increased level of PTEN protein, but a decrease in PI3K, total Akt, and phosphorylated Akt protein in HCC cells, suggesting involvement of the PI3K/Akt pathway.

Conclusions

FTCD acts as a tumor suppressor gene in HCC pathogenesis and progression and is a candidate prognostic marker and a possible therapeutic target for this disease.

Downregulation of microRNA-23b protects against ischemia-reperfusion injury via p53 signaling pathway by upregulating MDM4 in rats

Total knee arthroplasty is a commonly performed safe procedure and typically executed in severe knee arthritis, but it also triggers ischemia-reperfusion injury (IRI). More recently, microRNAs (miRs) have been reported to play a contributory role in IRI through the key signaling pathway. Hence, the current study aimed to investigate the effect and specific mechanism of microRNA-23b (miR-23b), murine double minute 4 (MDM4), and the p53 signaling pathway in IRI rat models. First, the IRI model was established, and the expression pattern of miR-23b, MDM4, and the p53 signaling pathway-related genes was characterized in cartilaginous tissues. Then, miR-23b mimics or inhibitors were applied for the elevation or the depletion of the miR-23b expression and siRNA-MDM4 for the depletion of the MDM4 expression in the articular chondrocytes. By means of immunohistochemistry, quantitative real-time polymerase chain reaction, and Western blot analysis, IRI rats exhibited increased miR-23b expression, activated p53 signaling pathway, and decreased MDM4 expression. MDM4 was verified as a target gene of miR-23b through. Downregulated miR-23b increased the expression of MDM4, AKT, and Bcl-2, but decreased the expression of p53, p21, and Bax. In addition, a series of cell experiments demonstrated that downregulated miR-23b promoted articular chondrocyte proliferation and cell cycle entry, but inhibited articular chondrocyte apoptosis. The absence of the effects of miR-23b was observed after MDM4 knocked down. Our results indicate that silencing miR-23b could act to attenuate IRI and reduce the apoptosis of articular chondrocytes through inactivation of the p53 signaling pathway by upregulating MDM4, which provide basic therapeutic considerations for a novel target against IRI.

Global analysis of tRNA and translation factor expression reveals a dynamic landscape of translational regulation in human cancers

The protein translational system, including transfer RNAs (tRNAs) and several categories of enzymes, plays a key role in regulating cell proliferation. Translation dysregulation also contributes to cancer development, though relatively little is known about the changes that occur to the translational system in cancer. Here, we present global analyses of tRNAs and three categories of enzymes involved in translational regulation in ~10,000 cancer patients across 31 cancer types from The Cancer Genome Atlas. By analyzing the expression levels of tRNAs at the gene, codon, and amino acid levels, we identified unequal alterations in tRNA expression, likely due to the uneven distribution of tRNAs decoding different codons. We find that overexpression of tRNAs recognizing codons with a low observed-over-expected ratio may overcome the translational bottleneck in tumorigenesis. We further observed overall overexpression and amplification of tRNA modification enzymes, aminoacyl-tRNA synthetases, and translation factors, which may play synergistic roles with overexpression of tRNAs to activate the translational systems across multiple cancer types.

Translation elongation factor eEF1Bα is identified as a novel prognostic marker of gastric cancer

Gastric cancer (GC) is a common cancer in humans. Although overexpression of eukaryotic translation elongation factor eEF1Bα is associated with cancer onset and progression, little is known about its expression in GC and its prognostic significance. Here we used immunohistochemistry to analyze eEF1Bα expression in the following tissue types: GC, normal gastric, chronic gastritis, intestinal metaplasia, and intraepithelial neoplasia. These data were correlated with patients' clinical information. eEF1Bα was expressed at levels approximately three times higher in GC tissues compared with normal gastric tissues. High expression of eEF1Bα was significantly associated with histological type, TNM stage, tumor size, and distant metastases. GC patients with high eEF1Bα expression experienced significantly shorter overall survival. Bioinformatics analysis indicated that eEF1Bα may be associated with protein synthesis, energy metabolism, cell cycle, and the p53 signaling pathway. We identified the products of RPL10A and RPS13 as critical components of a network comprising eEF1Bα. We concluded that high eEF1Bα expression is associated with poor overall survival and may serve as an independent prognostic factor of GC. Further, we proposed that eEF1Bα likely mediates the development of GC through the cell cycle and p53 signaling pathway. Together, our findings suggest that eEF1Bα could be an effective prognostic biomarker for GC.

Integrative analysis of significant RNA-binding proteins in colorectal cancer metastasis

The aberrant expression of RNA-binding proteins (RBPs) plays a crucial role in the occurrence and progression of human cancer. However, the key functions of RBPs in the metastasis of colorectal cancer have not yet been fully elucidated. Here, we integrated multi-omics data and identified four differentially expressed RBPs (APOBEC3G, EEF1A2, EIF5AL1 and CELF3) in patients with colorectal cancer metastasis. To clarify the underlying molecular mechanisms, we systematically analyzed the genomic features and downstream regulatory relationships of the four RBPs. In a genomic level, the copy number variations of APOBEC3G, EEF1A2, and CELF3 demonstrated significantly differential distributions between metastatic and nonmetastatic patients. Besides that, combining sequence and expression information, we identified 436 putative RNA targets regulated by the four RBPs through strict multistep bioinformatics screening. For the downstream analysis, the evidence from functional enrichment analysis and public literature indicated the roles of these target genes in the carcinogenesis and progression of colorectal cancer. Furthermore, through the machine learning algorithm and statistical analysis, we obtained two gene candidates that had obvious effects on the metastasis and overall survival status of patients with colorectal cancer. In summary, our study comprehensively explored the influence of APOBEC3G, EEF1A2, EIF5AL1, and CELF3 in colorectal cancer metastasis, which may offer favorable perspectives for clinical diagnosis and therapy.

Mass spectrometry-based proteomic analysis reveals the interacting partners of lipin1

As a lipin family founding member, lipin1 exerts dual functions as a phosphatidate phosphatase enzyme and/or a co-transcriptional regulator in lipid metabolism. In fact, it is also involved in many other cell processes. In this study, we utilized pull down assay coupled with mass spectrometry (MS) to unravel protein-protein interaction networks of lipin1 in 293T human embryonic kidney cells. Pull-down assay on the Ni²⁺ -chelating column was used to isolate lipin1 complexes from 293T cells transfected with 6-His tagged lipin1. The lipin1 complexes were analyzed on Q Exactive mass spectrometer. A total of 30 proteins were identified from label free quantitation of the MS data by Proteome Discoverer platform. The physical interaction between lipin1 and eEF1A1 was further affirmed in 293T cells transfected with 6-His tagged lipin1 and hepatocyte SMMC7721 cells by protein immunoprecipitation and immunofluorescence microscopy. Lipin1 also interacted with HIST1H2BK, which was confirmed in SMMC7721 cells by protein immunoprecipitation. Our proteomic analysis implicated lipin1 in novel roles in various cellular processes. © 2018 IUBMB Life, 70(8):753-762, 2018.

Polymer-Mediated Delivery of siRNAs to Hepatocellular Carcinoma: Variables Affecting Specificity and Effectiveness

Despite the advances in anticancer therapies, their effectiveness for many human tumors is still far from being optimal. Significant improvements in treatment efficacy can come from the enhancement of drug specificity. This goal may be achieved by combining the use of therapeutic molecules with tumor specific effects and delivery carriers with tumor targeting ability. In this regard, nucleic acid-based drug (NABD) and particularly small interfering RNAs (siRNAs), are attractive molecules due to the possibility to be engineered to target specific tumor genes. On the other hand, polymeric-based delivery systems are emerging as versatile carriers to generate tumor-targeted delivery systems. Here we will focus on the most recent findings in the selection of siRNA/polymeric targeted delivery systems for hepatocellular carcinoma (HCC), a human tumor for which currently available therapeutic approaches are poorly effective. In addition, we will discuss the most attracting and, in our opinion, promising siRNA-polymer combinations for HCC in relation to the biological features of HCC tissue. Attention will be also put on the mathematical description of the mechanisms ruling siRNA-carrier delivery, this being an important aspect to improve effectiveness reducing the experimental work.

Elevated eukaryotic elongation factor 2 expression is involved in proliferation and invasion of lung squamous cell carcinoma

Eukaryotic elongation factor 2 (EF2), is a critical enzyme solely responsible for catalyzing the translocation of the elongated peptidyl-tRNA from the A to P sites of the ribosome during the process of protein synthesis. EF2 is found to be highly expressed in a variety of malignant tumors and is correlated with cancer cell progression and recurrence. The present study was designed to uncover the function of EF2 on lung squamous cell carcinoma (LSCC) cancer cell growth and progression. Our results from clinical tissue studies showed that EF2 protein was significantly overexpressed in LSCC tissues, compared with the adjacent normal lung tissues, which was confirmed by western blotting and tissue microarray. Forced expression of EF2 resulted in the enhancement of lung squamous carcinoma NCI-H520 cells growth through promotion of G2/M progression in cell cycle, activating Akt and Cdc2/Cyclin B1. In nude mice cancer xenograft model, overexpression of EF2 significantly facilitated cell proliferation in vivo. Furthermore, forced expression of EF2 in the cells increased the capabilities of migration and invasion by changing the expressions of EMT-related proteins and genes. These results provided novel insights into the role of EF2 in tumorigenesis and progression in LSCC. EF2-targeted therapy could become a good strategy for the clinical treatment of LSCC.

NVP-BEZ235 synergizes cisplatin sensitivity in osteosarcoma

Osteosarcoma(OS) remains a major health concern in childhood and adolescence, although cisplatin is one of the gold standard chemotherapeutic drugs in the treatment of OS, chemoresistant to cisplatin is common. Phosphoinositide 3-kinase (PI3K)-Akt-mammalian target of rapamycin inhibitor (mTOR) pathway and autophagy regulates chemosensitivity incancer cells. In this study, we hypothesized that NVP-BEZ235, a dual inhibitor of PI3K/mTOR, could synergize cisplatin sensitivity in OS. In vitro, NVP-BEZ235 plus cisplatinexerted a synergistic effect on cell proliferation inhibition and apoptosis induction. Cisplatin could activate PI3K-Akt-mTOR pathway activity in early times, whereas, NVP-BEZ235 could inhibit PI3K-Akt -mTOR pathway activity all the times alone or combined with cisplatin. What's more, NVP-BEZ235 could switch function of autophagy induced by cisplatin to synergize cisplatin sensitivity. In vivo, pronounced decrease in tumor cell proliferation and increase in apoptosisin combination-treated mouse xenograft models compared with cisplatin or NVP-BEZ235 treated models. All these results suggest NVP-BEZ235 could synergize cisplatin sensitivity in OS, combination of NVP-BEZ235 with cisplatin could represent a novel therapeutic strategy for treatment of OS.

The EEF1A2 gene expression as risk predictor in localized prostate cancer

Background

Besides clinical stage and Gleason score, risk-stratification of prostate cancer in the pretherapeutic setting mainly relies on the serum PSA level. Yet, this is associated with many uncertainties. With regard to therapy decision-making, additional markers are needed to allow an exact risk prediction. Eukaryotic translation elongation factor 1 alpha 2 (EEF1A2) was previously suggested as driver of tumor progression and potential biomarker. In the present study its functional and prognostic relevance in prostate cancer was investigated.

Methods

EEF1A2 expression was analyzed in two cohorts of patients (n = 40 and n = 59) with localized PCa. Additionally data from two large expression dataset (MSKCC, Cell, 2010 with n = 131 localized, n = 19 metastatic PCa and TCGA provisional data, n = 499) of PCa patients were reanalyzed. The expression of EEF1A2 was correlated with histopathology features and biochemical recurrence (BCR). To evaluate the influence of EEF1A2 on proliferation and migration of metastatic PC3 cells, siRNA interference was used. Statistical significance was tested with t-test, Mann-Whitney-test, Pearson correlation and log-rank test.

Results

qRT-PCR revealed EEF1A2 to be significantly overexpressed in PCa tissue, with an increase according to tumor stage in one cohort (p = 0.0443). In silico analyses in the MSKCC cohort confirmed the overexpression of EEF1A2 in localized PCa with high Gleason score (p = 0.0142) and in metastatic lesions (p = 0.0038). Patients with EEF1A2 overexpression had a significantly shorter BCR-free survival (p = 0.0028). EEF1A2 expression was not correlated with serum PSA levels. Similar results were seen in the TCGA cohort, where EEF1A2 overexpression only occurred in tumors with Gleason 7 or higher. Patients with elevated EEF1A2 expression had a significantly shorter BCR-free survival (p = 0.043). EEF1A2 knockdown significantly impaired the migration, but not the proliferation of metastatic PC3 cells.

Conclusion

The overexpression of EEF1A2 is a frequent event in localized PCa and is associated with histopathology features and a shorter biochemical recurrence-free survival. Due to its independence from serum PSA levels, EEF1A2 could serve as valuable biomarker in risk-stratification of localized PCa.