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

Emerging roles of deubiquitinating enzymes in actin cytoskeleton and tumor metastasis

BACKGROUND

Metastasis accounts for the majority of cancer-related deaths. Actin dynamics and actin-based cell migration and invasion are important factors in cancer metastasis. Metastasis is characterized by actin polymerization and depolymerization, which are precisely regulated by molecular changes involving a plethora of actin regulators, including actin-binding proteins (ABPs) and signalling pathways, that enable cancer cell dissemination from the primary tumour. Research on deubiquitinating enzymes (DUBs) has revealed their vital roles in actin dynamics and actin-based migration and invasion during cancer metastasis.

CONCLUSION

Here, we review how DUBs drive tumour metastasis by participating in actin rearrangement and actin-based migration and invasion. We summarize the well-characterized and essential actin cytoskeleton signalling molecules related to DUBs, including Rho GTPases, Src kinases, and ABPs such as cofilin and cortactin. Other DUBs that modulate actin-based migration signalling pathways are also discussed. Finally, we discuss and address therapeutic opportunities and ongoing challenges related to DUBs with respect to actin dynamics.

USP11 promotes prostate cancer progression by up-regulating AR and c-Myc activity

Androgen receptor (AR) is a main driver for castration-resistant prostate cancer (CRPC). c-Myc is an oncogene underlying prostate tumorigenesis. Here, we find that the deubiquitinase USP11 targets both AR and c-Myc in prostate cancer (PCa). USP11 expression was up-regulated in metastatic PCa and CRPC. USP11 knockdown (KD) significantly inhibited PCa cell growth. Our RNA-seq studies revealed AR and c-Myc as the top transcription factors altered after USP11 KD. ChIP-seq analysis showed that either USP11 KD or replacement of endogenous USP11 with a catalytic-inactive USP11 mutant significantly decreased chromatin binding by AR and c-Myc. We find that USP11 employs two mechanisms to up-regulate AR and c-Myc levels: namely, deubiquitination of AR and c-Myc proteins to increase their stability and deubiquitination of H2A-K119Ub, a repressive histone mark, on promoters of AR and c-Myc genes to increase their transcription. AR and c-Myc reexpression in USP11-KD PCa cells partly rescued cell growth defects. Thus, our studies reveal a tumor-promoting role for USP11 in aggressive PCa through upregulation of AR and c-Myc activities and support USP11 as a potential target against PCa.

GDF11 inhibits the malignant progression of hepatocellular carcinoma via regulation of the mTORC1‑autophagy axis

Hepatocellular carcinoma (HCC) is a common malignant tumor, which is associated with a poor prognosis and high mortality rate. It is well known that growth differentiation factor 11 (GDF11) acts as a tumor suppressor in various types of cancer, including HCC. The present study aimed to determine the tumor-suppressive properties of GDF11 in HCC and to assess the intrinsic mechanisms. In the present study, the human hepatoma cell line Huh-7 was transfected with the GDF11 overexpression plasmid (Oe-GDF11) for gain-of-function experiments to investigate the effects of GDF11 on the biological behaviors of HCC cells, including proliferation, colony formation, apoptosis, cell cycle arrest, migration, invasion, epithelial-mesenchymal transition (EMT) and angiogenesis. The proliferation, colony formation, apoptosis, cell cycle, migration, invasion and angiogenesis of HCC cells were assessed by CCK-8, EdU staining, colony formation, flow cytometry, wound healing, Transwell and tube formation assays, respectively. Apoptosis-, cell cycle-, EMT-related key factors were also determined by western blot assay. Furthermore, Oe-GDF11-transfected Huh-7 cells were treated with the mammalian target of rapamycin (mTOR) activator MHY1485 for rescue experiments to explore whether GDF11 could exert antitumor effects against HCC via mediating the mTOR complex 1 (mTORC1)-autophagy axis. In the present study, GDF11 was verified to be lowly expressed in HCC cells. Overexpression of GDF11 inhibited the proliferation, colony formation, migration, invasion, EMT and angiogenesis of HCC cells, and facilitated the apoptosis and cell cycle arrest of HCC cells. Additionally, it was verified that overexpression of GDF11 inactivated the mTORC1 signaling pathway to enhance autophagy in HCC cells. Treatment with the mTOR activator MHY1485 partially reversed the tumor-suppressive effects of GDF11 overexpression on HCC. In conclusion, GDF11 may exert tumor-suppressive properties in HCC cells through inactivating the mTORC1 signaling pathway to strengthen autophagy.

Activation of the cGMP/PKG/ERK signaling pathway associated with PDE5Is inhibits fibroblast activation by downregulating autophagy in early progressive benign prostatic hyperplasia

PURPOSE

Benign prostatic hyperplasia (BPH) is one of the most prevalent diseases affecting aging males. However, approximately, 8% of the BPH patients under 50-year-old experience remarkably early progression, for reasons that remain elusive. Among the various factors implicated in promoting BPH advancement, the activation of fibroblasts and autophagy hold particular importance. Our research endeavors to explore the mechanisms behind the accelerated progression in these patients.

METHODS

Immunohistochemistry and immunofluorescence were performed to detect the expression levels of LC3, p62, PDE5, and α-SMA in diverse BPH tissues and prostate stromal cells. The autophagy activator rapamycin, the autophagy suppressor chloroquine, and siRNA transfection were used to identify the impact of autophagy on fibroblast activation.

RESULTS

Prostatic stromal fibroblasts in early progressive BPH tissues displayed activation of autophagy with an upregulation of LC3 and a concurrent downregulation of p62. After starvation or rapamycin treatment to a heightened level of autophagy, fibroblasts exhibited activation. Conversely, chloroquine treatment and ATG-7-knockdown effectively suppressed the level of autophagy and fibroblast activation. High expression of PDE5 was found in early progressive BPH stromal cells. The administration of PDE5 inhibitors (PDE5Is) hindered fibroblast activation through suppressing autophagy by inhibiting the ERK signaling pathway.

CONCLUSION

Our findings suggest that autophagy plays a pivotal role in promoting BPH progression through fibroblast activation, while PDE5Is effectively suppress autophagy and fibroblast activation via the ERK signaling pathway. Nevertheless, further investigations are warranted to comprehensively elucidate the role of autophagy in BPH progression.

Identification of arnicolide C as a novel chemosensitizer to suppress mTOR/E2F1/FANCD2 axis in non-small cell lung cancer

BACKGROUND AND PURPOSE

The mammalian target of rapamycin (mTOR) pathway plays critical roles in intrinsic chemoresistance by regulating Fanconi anaemia complementation group D2 (FANCD2) expression. However, the mechanisms by which mTOR regulates FANCD2 expression and related inhibitors are not clearly elucidated. Extracts of Centipeda minima (C. minima) showed promising chemosensitizing effects by inhibiting FANCD2 activity. Here, we have aimed to identify the bioactive chemosensitizer in C. minima extracts and elucidate its underlying mechanism.

EXPERIMENTAL APPROACH

The chemosensitizing effects of arnicolide C (ArC), a bioactive compound in C. minima, on non-small cell lung cancer (NSCLC) were investigated using immunoblotting, immunofluorescence, flow cytometry, the comet assay, small interfering RNA (siRNA) transfection and animal models. The online SynergyFinder software was used to determine the synergistic effects of ArC and chemotherapeutic drugs on NSCLC cells.

KEY RESULTS

ArC had synergistic cytotoxic effects with DNA cross-linking drugs such as cisplatin and mitomycin C in NSCLC cells. ArC treatment markedly decreased FANCD2 expression in NSCLC cells, thus attenuating cisplatin-induced FANCD2 nuclear foci formation, leading to DNA damage and apoptosis. ArC inhibited the mTOR pathway and attenuated mTOR-mediated expression of E2F1, a critical transcription factor of FANCD2. Co-administration of ArC and cisplatin exerted synergistic anticancer effects in the A549 xenograft mouse model by suppressing mTOR/FANCD2 signalling in tumour tissues.

CONCLUSION AND IMPLICATIONS

ArC suppressed DNA cross-linking drug-induced DNA damage response by inhibiting the mTOR/E2F1/FANCD2 signalling axis, serving as a chemosensitizing agent. This provides insight into the anticancer mechanisms of ArC and offers a potential combinatorial anticancer therapeutic strategy.

DLGAP5 triggers proliferation and metastasis of bladder cancer by stabilizing E2F1 via USP11

Bladder cancer (BLCA) is one of the most widespread malignancies worldwide, and displays significant tumor heterogeneity. Understanding the molecular mechanisms exploitable for treating aggressive BLCA represents a crucial objective. Despite the involvement of DLGAP5 in tumors, its precise molecular role in BLCA remains unclear. BLCA tissues exhibit a substantial increase in DLGAP5 expression compared with normal bladder tissues. This heightened DLGAP5 expression positively correlated with the tumor's clinical stage and significantly affected prognosis negatively. Additionally, experiments conducted in vitro and in vivo revealed that alterations in DLGAP5 expression notably influence cell proliferation and migration. Mechanistically, the findings demonstrated that DLGAP5 was a direct binding partner of E2F1 and that DLGAP5 stabilized E2F1 by preventing the ubiquitination of E2F1 through USP11. Furthermore, as a pivotal transcription factor, E2F1 fosters the transcription of DLGAP5, establishing a positive feedback loop between DLGAP5 and E2F1 that accelerates BLCA development. In summary, this study identified DLGAP5 as an oncogene in BLCA. Our research unveils a novel oncogenic mechanism in BLCA and offers a potential target for both diagnosing and treating BLCA.

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

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

USP11 potentiates HGF/AKT signaling and drives metastasis in hepatocellular carcinoma

USP11 is a member of the ubiquitin-specific protease family and plays a crucial role in tumor progression in various cancers. However, the precise mechanism by which USP11 promotes EMT and metastasis in hepatocellular carcinoma (HCC) is not fully understood. In this study, we demonstrated that the USP11 expression was dramatically upregulated in HCC tissues and cell lines. Increased USP11 expression was closely associated with tumor number, vascular invasion, and poor prognosis. Functional experiments demonstrated that USP11 markedly promoted metastasis and EMT in HCC via induction of the transcription factor Snail. Mechanistically, USP11 interacted with and deubiquitinated eEF1A1 on Lys439, thereby inhibiting its ubiquitin-mediated degradation. Subsequently, the elevated expression of eEF1A1 resulted in its binding to SP1, which in turn drove the binding of SP1 to its target HGF gene promoter to increase its transcription. This led to an enhanced expression of HGF and the activation of the downstream PI3K/AKT signaling pathway. We demonstrated that USP11 promotes EMT and metastasis in HCC via eEF1A1/SP1/HGF dependent-EMT. Our findings suggest that the USP11/ eEF1A1/SP1/HGF axis contributes to metastasis in HCC, and therefore, could be considered as a potential therapeutic target for the treatment of HCC.

Construction of an anoikis‒related prognostic signature to predict immunotherapeutic response and prognosis in hepatocellular carcinoma

PURPOSE

Anoikis resistance is an important inducer of tumor metastasis. The role of anoikis-related genes (ARGs) in hepatocellular carcinoma (HCC) remains unclear.

METHODS

A list of ARGs was obtained and regression analysis was employed to assemble an anoikis-related prognostic signature and risk score formula from mRNA data and clinical prognostic data downloaded from The Cancer Genome Atlas database. Quantitative real-time PCR (qRT-PCR) was performed on clinical samples to validate the selected ARGs expressions. Kaplan‒Meier curves, ROC curves, and Cox regression analyses were used to demonstrated the prognostic value of this signature. Biological functional enrichment analysis and immune infiltration analysis were utilized to analyze the differences in potential biological functions, immune cell infiltration, immune functions, and immunotherapeutic responses.

RESULTS

A prognostic signature based on 6 ARGs and corresponding prognostic nomogram were established. Our qRT-PCR results showed a higher expression of 6 ARGs in HCC tissues (p value < 0.05). Kaplan‒Meier curves, ROC curves, and Cox regression analyses demonstrated good prognostic value of the signature in HCC (p value < 0.05). Significant differences between the enriched biological functions and immune landscapes of patients in different risk groups were discovered (p value < 0.05). In addition, patients with higher risk scores possibly had poor therapeutic response to transhepatic arterial chemotherapy and embolization or sorafenib, but their responses to immunotherapy might be more effective.

CONCLUSION

A successful anoikis-related prognostic signature and corresponding clinical nomogram were established, which might facilitate better predictions of prognosis and therapeutic responses for HCC patients.

A novel oxidative stress-related genes signature associated with clinical prognosis and immunotherapy responses in clear cell renal cell carcinoma

Background

Oxidative stress plays a significant role in the tumorigenesis and progression of tumors. We aimed to develop a prognostic signature using oxidative stress-related genes (ORGs) to predict clinical outcome and provide light on the immunotherapy responses of clear cell renal cell carcinoma (ccRCC).

Methods

The information of ccRCC patients were collected from the TCGA and the E-MTAB-1980 datasets. Univariate Cox regression analysis and least absolute shrinkage and selection operator (LASSO) were conducted to screen out overall survival (OS)-related genes. Then, an ORGs risk signature was built by multivariate Cox regression analyses. The performance of the risk signature was evaluated with Kaplan-Meier (K-M) survival. The ssGSEA and CIBERSORT algorithms were performed to evaluate immune infiltration status. Finally, immunotherapy responses was analyzed based on expression of several immune checkpoints.

Results

A prognostic 9-gene signature with ABCB1, AGER, E2F1, FOXM1, HADH, ISG15, KCNMA1, PLG, and TEK. The patients in the high risk group had apparently poor survival (TCGA: p < 0.001; E-MTAB-1980: p < 0.001). The AUC of the signature was 0.81 at 1 year, 0.76 at 3 years, and 0.78 at 5 years in the TCGA, respectively, and was 0.8 at 1 year, 0.82 at 3 years, and 0.83 at 5 years in the E-MTAB-1980, respectively. Independent prognostic analysis proved the stable clinical prognostic value of the signature (TCGA cohort: HR = 1.188, 95% CI =1.142-1.236, p < 0.001; E-MTAB-1980 cohort: HR =1.877, 95% CI= 1.377-2.588, p < 0.001). Clinical features correlation analysis proved that patients in the high risk group were more likely to have a larger range of clinical tumor progression. The ssGSEA and CIBERSORT analysis indicated that immune infiltration status were significantly different between two risk groups. Finally, we found that patients in the high risk group tended to respond more actively to immunotherapy.

Conclusion

We developed a robust prognostic signature based on ORGs, which may contribute to predict survival and guide personalize immunotherapy of individuals with ccRCC.

Cadmium affects autophagy in the human intestinal cells Caco-2 through ROS-mediated ERK activation

Cadmium is a toxic metal that enters the food chain. Following oral ingestion, the intestinal epithelium has the capacity to accumulate high levels of this metal. We have previously shown that Cd induces ERK1/2 activation in differentiated but not proliferative human enterocytic-like Caco-2 cells. As autophagy is a dynamic process that plays a critical role in intestinal mucosa, we aimed the present study 1) to investigate the role of p-ERK1/2 in constitutive autophagy in proliferative Caco-2 cells and 2) to investigate whether Cd-induced activation of ERK1/2 modifies autophagic activity in postconfluent Caco-2 cell monolayers. Western blot analyses of ERK1/2 and autophagic markers (LC3, SQSTM1), and cellular staining with acridine orange showed that ERK1/2 and autophagic activities both decreased with time in culture. GFP-LC3 fluorescence was also associated with proliferative cells and the presence of a constitutive ERK1/2-dependent autophagic flux was demonstrated in proliferative but not in postconfluent cells. In the latter condition, serum and glucose deprivation triggered autophagy via a transient phosphorylation of ERK1/2, whereas Cd-modified autophagy via a ROS-dependent sustained activation of ERK1/2. Basal autophagy flux in proliferative cells and Cd-induced increases in autophagic markers in postconfluent cells both involved p-ERK1/2. Whether Cd blocks autophagic flux in older cell cultures remains to be clarified but our data suggest dual effects. Our results prompt further studies investigating the consequences that Cd-induced ERK1/2 activation and the related effect on autophagy may have on the intestinal cells, which may accumulate and trap high levels of Cd under some nutritional conditions.

Bioinformatics analysis and experimental validation of a novel autophagy-related signature relevant to immune infiltration for recurrence prediction after curative hepatectomy

Hepatocellular carcinoma (HCC) remains imposing an enormous economic and healthcare burden worldwide. In this present study, we constructed and validated a novel autophagy-related gene signature to predict the recurrence of HCC patients. A total of 29 autophagy-related differentially expressed genes were identified. A five-gene signature (CLN3, HGF, TRIM22, SNRPD1, and SNRPE) was constructed for HCC recurrence prediction. Patients in high-risk groups exhibited a significantly poor prognosis compared with low-risk patients both in the training set (GSE14520 dataset) and the validation set (TCGA and GSE76427 dataset). Multivariate cox regression analysis demonstrated that the 5-gene signature was an independent risk factor for recurrence-free survival (RFS) in HCC patients. The nomograms incorporating 5-gene signature and clinical prognostic risk factors were able to effectively predict RFS. KEGG and GSEA analysis revealed that the high-risk group was enriched with multiple oncology characteristics and invasive-related pathways. Besides, the high-risk group had a higher level of immune cells and higher levels of immune checkpoint-related gene expression in the tumor microenvironment, suggesting that they might be more likely to benefit from immunotherapy. Finally, the immunohistochemistry and cell experiments confirmed the role of SNRPE, the most significant gene in the gene signature. SNRPE was significantly overexpressed in HCC. After SNRPE knockdown, the proliferation, migration and invasion ability of the HepG2 cell line were significantly inhibited. Our study established a novel five-gene signature and nomogram to predict RFS of HCC, which may help in clinical decision-making for individual treatment.

Nedd4L suppression in lung fibroblasts facilitates pathogenesis of lung fibrosis

Ubiquitination-mediated protein degradation is associated with the development of pulmonary fibrosis. We and others have shown that Nedd4L plays anti-inflammatory and anti-fibrotic roles by targeting lysophosphatidic acid receptor 1 (LPAR1), p-Smad2/3, and β-catenin, and other molecules for their degradation in lung epithelial cells and fibroblasts. However, the molecular regulation of Nedd4L expression in lung fibroblasts has not been studied. In this study, we find that Nedd4L levels are significantly suppressed in lung myofibroblasts in IPF patients and in experimental pulmonary fibrosis, and in TGF-β1-treated lung fibroblasts. Nedd4L knockdown promotes TGF-β1-mediated phosphorylation of Smad2/3 and lung myofibroblast differentiation. Mechanistically, Nedd4L targets TGF-β receptor II (TβRII), the first key enzyme of TGF-β1-mediated signaling, for its ubiquitination and degradation. Further, we show that inhibition of transcriptional factor E2F rescues Nedd4L levels and mitigates experimental pulmonary fibrosis. Together, our data reveal insight into mechanisms by which E2F-mediated Nedd4L suppression contributes to the pathogenesis of lung fibrosis. This study provides evidence showing that upregulation of Nedd4L is a potential therapeutic strategy to treat fibrotic disorders including lung fibrosis.

Targeting and regulation of autophagy in hepatocellular carcinoma: revisiting the molecular interactions and mechanisms for new therapy approaches

Autophagy is an evolutionarily conserved process that plays a role in regulating homeostasis under physiological conditions. However, dysregulation of autophagy is observed in the development of human diseases, especially cancer. Autophagy has reciprocal functions in cancer and may be responsible for either survival or death. Hepatocellular carcinoma (HCC) is one of the most lethal and common malignancies of the liver, and smoking, infection, and alcohol consumption can lead to its development. Genetic mutations and alterations in molecular processes can exacerbate the progression of HCC. The function of autophagy in HCC is controversial and may be both tumor suppressive and tumor promoting. Activation of autophagy may affect apoptosis in HCC and is a regulator of proliferation and glucose metabolism. Induction of autophagy may promote tumor metastasis via induction of EMT. In addition, autophagy is a regulator of stem cell formation in HCC, and pro-survival autophagy leads to cancer cell resistance to chemotherapy and radiotherapy. Targeting autophagy impairs growth and metastasis in HCC and improves tumor cell response to therapy. Of note, a large number of signaling pathways such as STAT3, Wnt, miRNAs, lncRNAs, and circRNAs regulate autophagy in HCC. Moreover, regulation of autophagy (induction or inhibition) by antitumor agents could be suggested for effective treatment of HCC. In this paper, we comprehensively review the role and mechanisms of autophagy in HCC and discuss the potential benefit of targeting this process in the treatment of the cancer. Video Abstract.

A positive feedback loop of CENPU/E2F6/E2F1 facilitates proliferation and metastasis via ubiquitination of E2F6 in hepatocellular carcinoma

Centromere protein U (CENPU), a centromere-binding protein required for cellular mitosis, has been reported to be closely associated with carcinogenesis in multiple malignancies; however, the role of CENPU in hepatocellular carcinoma (HCC) is still unclear. Herein, we investigated its biological role and molecular mechanism in the development of HCC. High CENPU expression in HCC tissue was observed and correlated positively with a poor prognosis in HCC patients. CENPU knockdown inhibited the proliferation, metastasis, and G1/S transition of HCC cells in vivo and in vitro, while ectopic expression of CENPU exerted the opposite effects. Mechanistically, CENPU physically interacted with E2F6 and promoted its ubiquitin-mediated degradation, thus affecting the transcription level of E2F1 and further accelerating the G1/S transition to promote HCC cell proliferation. E2F1 directly binds to the CENPU promoter and increases the transcription of CENPU, thereby forming a positive regulatory loop. Collectively, our findings indicate a crucial role for CENPU in E2F1-mediated signalling for cell cycle progression and reveal a role for CENPU as a predictive biomarker and therapeutic target for HCC patients.

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

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

The nociceptin receptor promotes autophagy through NF-kB signaling and is transcriptionally regulated by E2F1 in HCC

Opioids and their receptors are involved in cancer progression. However, the roles of the nociceptin receptor (NOP) and its antagonist (JTC801) in hepatocellular carcinoma (HCC) are poorly understood. The prognostic value of NOP expression was evaluated using tissue microarray and immunohistochemical staining analyses in a human HCC cohort. The biological role and mechanism of NOP in HCC tumor growth were determined in vitro and in vivo. We found that NOP was associated with the clinicopathological features and survival outcomes of HCC patients. NOP overexpression promoted HCC growth in vitro and in vivo. Mechanistically, NOP activated NF-kB signaling to promote autophagy, which inhibited apoptosis, in HCC cells. An inhibitor of autophagy, 3-MA, and an inhibitor of NF-kB, JSH-23, attenuated the function of NOP in HCC. E2F1 was identified as a transcription factor of NOP. The oncogenic role of NOP was positively regulated by E2F1. Furthermore, JTC801, a selective antagonist of NOP, abolished the function of NOP by inhibiting NF-kB signaling and autophagy. Our study demonstrates that NOP is an oncogene in HCC. We provide a potential therapeutic candidate and prognostic predictor for HCC. JTC801 could become a potential drug for HCC therapy.

A novel machine learning derived RNA-binding protein gene-based score system predicts prognosis of hepatocellular carcinoma patients

Background

Although the expression of RNA-binding protein (RBP) genes in hepatocellular carcinoma (HCC) varies and is associated with tumor progression, there has been no overview study with multiple cohorts and large samples. The HCC-associated RBP genes need to be more accurately identified, and their clinical application value needs to be further explored.

Methods

First, we used the robust rank aggregation (RRA) algorithm to extract HCC-associated RBP genes from nine HCC microarray datasets and verified them in The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC) cohort and International Cancer Genome Consortium (ICGC) Japanese liver cancer (ICGC-LIRI-JP) cohort. In addition, the copy number variation (CNV), single-nucleotide variant (SNV), and promoter-region methylation data of HCC-associated RBP genes were analyzed. Using the random forest algorithm, we constructed an RBP gene–based prognostic score system (RBP-score). We then evaluated the ability of RBP-score to predict the prognosis of patients. The relationships between RBP-score and other clinical characteristics of patients were analyzed.

Results

The RRA algorithm identified 30 RBP mRNAs with consistent expression patterns across the nine HCC microarray datasets. These 30 RBP genes were defined as HCC-associated RBP genes. Their mRNA expression patterns were further verified in the TCGA-LIHC and ICGC-LIRI-JP cohorts. Among these 30 RBP genes, some showed significant copy number gain or loss, while others showed differences in the methylation levels of their promoter regions. Some RBP genes were risk factors or protective factors for the prognosis of patients. We extracted 10 key HCC-associated RBP genes using the random forest algorithm and constructed an RBP-score system. RBP-score effectively predicted the overall survival (OS) and disease-free survival (DFS) of HCC patients and was associated with the tumor, node, metastasis (TNM) stage, α-fetoprotein (AFP), and metastasis risk. The clinical value of RBP-score was validated in datasets from different platforms. Cox analysis suggested that a high RBP-score was an independent risk factor for poor prognosis in HCC patients. We also successfully established a combined RBP-score+TNM LASSO-Cox model that more accurately predicted the prognosis.

Conclusion

The RBP-score system constructed based on HCC-associated RBP genes is a simple and highly effective prognostic evaluation tool. It is suitable for different subgroups of HCC patients and has cross-platform characteristics. Combining RBP-score with the TNM staging system or other clinical parameters can lead to an even greater clinical benefit. In addition, the identified HCC-associated RBP genes may serve as novel targets for HCC treatment.

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

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

FGF14-AS2 accelerates tumorigenesis in glioma by forming a feedback loop with miR-320a/E2F1 axis

Glioma is the most common primary tumour in the central nervous system in adults, and at present, there is no effective treatment to cure this malignancy. Long noncoding RNAs (lncRNAs) are closely related to tumour progression and have attracted increasing attention in tumour research. However, the role of lncRNA FGF14-AS2 in glioma tumorigenesis has not been determined. In the present study, we found that FGF14-AS2 expression was significantly elevated in glioma tissues and was associated with poor survival in glioma patients. Silencing FGF14-AS2 inhibited the proliferation, migration and invasion ability of glioma cells. In vivo assay showed that silencing FGF14-AS2 led to inhibition of tumour growth. In addition, FGF14-AS2 was observed to promote glioma progression via the miR-320a/E2F1 axis. Moreover, E2F1 could bind to the promoter region of FGF14-AS2, thereby enhancing FGF14-AS2 expression. In conclusion, FGF14-AS2 could accelerate tumorigenesis of glioma by forming a feedback loop with the miR-320a/E2F1 axis which suggested that FGF14-AS2 could serve as a therapeutic target for glioma.