USP5 Promotes Ripretinib Resistance in Gastrointestinal Stromal Tumors by MDH2 Deubiquition.

Ripretinib, a broad-spectrum inhibitor of the KIT and PDGFRA receptor tyrosine kinases, is designated as a fourth-line treatment for gastrointestinal stromal tumor (GIST). It is tailored for patients resistant to imatinib, sunitinib, and regorafenib. As its increasing use, instances of resistance to ripretinib are becoming more frequent. Unfortunately, there are currently no scientifically mature treatment options available for patients resistant to ripretinib. Posttranslational modifications (PTMs) such as ubiquitination, in conjunction with its interplay with other modifications, play a collective role in regulating tumor initiation and progression. However, the specific association between ubiquitination and ripretinib resistance is not reported. Through proteome-ubiquitinome sequencing, increased levels of the USP5 protein and decreased ubiquitination in ripretinib-resistant GISTs are detected. Subsequent examination of the mass spectrometry findings validated the interaction through which TRIM21 governs USP5 expression via ubiquitination, and USP5 regulates MDH2 expression through deubiquitination, consequently fostering ripretinib resistance in GIST. Moreover, ZDHHC18 can palmitoylate MDH2, preventing its ubiquitination and further increasing its protein stability. The research underscores the correlation between posttranslational modifications, specifically ubiquitination, and drug resistance, emphasizing the potential of targeting the USP5-MDH2 axis to counteract ripretinib resistance in GIST.

Achieving highly efficient 2D SnC monolayer-based photocatalyst for water splitting via a synergistic strategy of S-scheme heterostructure construction and silicon doping.

Owing to its stable graphene-like honeycomb structure, suitable band gap, and nontoxicity, SnC monolayer (ML) has attracted increasing attention in photocatalytic applications. One pertinent obstacle inherent to SnC ML-based photocatalysts has been the high energy barrier in hydrogen evolution reaction (HER) that always requires external energy input and/or strongly acidic conditions. Herein, we propose a two-dimensional (2D) SnC/ZrS2 van der Waals heterostructure (vdWHS) for highly efficient photocatalytic water splitting using first-principles calculations. The results show that the pristine vdWHS is an S-scheme heterostructure that works in acidic conditions for water splitting owing to the high energy barrier in HER. Notably, detailed further investigations show that doping Si in the SnC ML of the vdWHS can solve this high barrier problem, leading to a high-performance low-cost photocatalyst. Our work offers a convenient strategy to solve the notorious high barrier problem in HER that often troubles the SnC ML and other 2D materials such as transition metal dichalcogenide MLs for the design and fabrication of highly efficient photocatalysts.

Survival benefit of liver resection following complete response to transarterial chemoembolization for intermediate-stage hepatocellular carcinoma: a retrospective, multicenter, cohort study.

BACKGROUND: High rate of tumor recurrence jeopardized the long-term survival of hepatocellular carcinoma (HCC) patients with complete response to transarterial chemoembolization (TACE). This study aims to evaluate the survival benefit of liver resection (LR) following the complete response to TACE for intermediate-stage HCC. METHODS: A total of 281 intermediate-stage HCC patients with complete response to TACE followed by persistent observation (TACE group) or LR (TLR group) from 01 January 2011 to 31 December 2021 from three institutions in China were included. Overall survival (OS) and disease-free survival (DFS) of patients were compared between the two groups by propensity score-matching (PSM). RESULTS: After PSM, the 1-year, 3-year, and 5-year OS rates were 91.4, 71.5, and 57.1% in the TACE group, and 96.6, 81.8, and 72.1% in the TLR group. The 1-year, 3-year, and 5-year DFS rates were 50.6, 22.6, and 6.8% in the TACE group, and 77.3, 56.3, and 38.7% in the TLR group. Compared with the TACE group, the TLR group showed significantly longer OS (HR, 0.528; 95% CI: 0.315-0.887; P =0.014) and DFS (HR, 0.388; 95% CI: 0.260-0.580; P <0.001). In patients beyond up-to-seven criterion, no difference was observed with OS (HR, 0.708; 95% CI: 0.354-1.419; P =0.329). LR following the complete response to TACE was safety. CONCLUSIONS: This study suggests that intermediate-stage HCC patients could benefit from LR following the complete response to TACE, resulting in longer OS and DFS. In addition, patients beyond up-to-seven could not benefit from the LR treatments.

Dimeric oxyberberine CT4-1 targets LINC02331 to induce cytotoxicity and inhibit chemoresistance via suppressing Wnt/ß-catenin signaling in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a type of cancer characterized by high recurrence rates. Overcoming chemoresistance can reduce HCC recurrence and improve patients' prognosis. This work aimed to identify HCC chemoresistance-associated long non-coding RNA (lncRNA) and find an effective drug targeting the identified lncRNA for ameliorating the chemoresistance. In this investigation, bioinformatics analysis based on The Cancer Genome Atlas revealed a new chemoresistance index and suggested LINC02331 as an HCC chemoresistance and patients' prognosis-associated lncRNA that served as an independent prognostic indicator. Moreover, LINC02331 promoted DNA damage repair, DNA replication, and epithelial-mesenchymal transition as well as attenuated cell cycle arrest and apoptosis through regulating Wnt/ß-catenin signaling, thus stimulating HCC resistance to cisplatin cytotoxicity, proliferation, and metastasis. Interestingly, we developed a novel oxidative coupling approach to synthesize a dimeric oxyberberine CT4-1, which exerted superior anti-HCC activities without obvious side effects measured by in vivo mice model and could downregulate LINC02331 mice model and could downregulate LINC02331 to mitigate LINC02331-induced HCC progression by suppressing Wnt/ß-catenin signaling. RNA sequencing analyses verified the involvement of CT4-1-affected differential expression genes in dysregulated pathways and processes, including Wnt, DNA damage repair, cell cycle, DNA replication, apoptosis, and cell adhesion molecules. Furthermore, CT4-1 was demonstrated to be an effective cytotoxic drug in ameliorating HCC patients' prognosis with a prediction model constructed based on RNA-sequencing data from CT4-1-treated cancer cells and public cancer database. In summary, HCC chemoresistance-associated LINC02331 independently predicted poor patients' prognosis and enhanced HCC progression by promoting resistance to cisplatin cytotoxicity, proliferation, and metastasis. Targeting LINC02331 by the dimeric oxyberberine CT4-1 that exhibited synergistic cytotoxicity with cisplatin could alleviate HCC progression and improve patients' prognosis. Our study identified LINC02331 as an alternative target and suggested CT4-1 as an effective cytotoxic drug in HCC treatment.

H4-methylation regulators mediated epitranscriptome patterns and tumor microenvironment infiltration characterization in hepatocellular carcinoma.

Epigenetic modifications are involved in the remodeling of the tumor microenvironment (TME) and the regulation of immune response. Nonetheless, the role of histone H4 methylation (H4M) modification in the TME and immune regulation of hepatocellular carcinoma (HCC) is unknown. As a result, the purpose of this research is to discover H4M-mediated modification patterns and their effects on TME and immunologic characteristics in HCC. A total of 2305 samples were enrolled from 13 different cohorts. With the help of consensus clustering analysis, three distinct H4M modification patterns were identified. The cell-infiltrating characteristics of TME under these three patterns were highly consistent with their enriched biological processes and clinical outcome. The H4Mscore was then created using principal component analysis algorithm to quantify the H4M modification pattern of each individual tumor and was systematically correlated with representative tumor characteristics. We found that analyzing H4M modification patterns within individual tumors could predict TME infiltration, homologous recombination deficiency (HRD), intratumor heterogeneity, proliferation activity, mRNA stemness index, and prognosis. The group with a low H4Mscore had an inflamed TME phenotype and a better immunotherapy response, as well as a better survival outcome. The prognostic value of H4Mscore was validated in three internal cohorts and five external cohorts, respectively. In external immunotherapy cohorts, the low H4Mscore was also linked to an enhanced response to anti-PD-1/L1 and anti-CTLA4 immunotherapy and a better prognosis. This study revealed that H4M modification played an important role in forming TME diversity and complexity. Evaluating the H4M modification pattern of individual tumors could help us learn more about TME and develop more effective immunotherapy strategies.

Multiomics analyses and machine learning of nuclear receptor coactivator 6 reveal its essential role in hepatocellular carcinoma.

Nuclear receptor coactivator 6 (NCOA6), a coactivator of numerous nuclear receptors and transcription factors, regulates multiple critical cellular functions. Nuclear receptor coactivator 6 is dysregulated in various cancers, including hepatocellular carcinoma (HCC); however, its role remains largely unknown. Here we reported that NCOA6 was highly expressed in HCC compared to the adjacent liver tissue, and NCOA6 overexpression was significantly correlated with poor HCC prognosis. Experiments revealed that the knockdown of NCOA6 damaged the proliferation, migration, and invasion of HCC cells. Multiomics and immune infiltration analyses showed a close relationship between NCOA6 expression, multiple cancer-related malignant pathways, and the immunosuppressive microenvironment. Finally, we established an effective NCOA6-related microRNA (miRNA) signature to distinguish HCC from hepatitis\liver cirrhosis patients. To the best of our knowledge, this study is the first to provide a comprehensive analysis of NCOA6 expression in HCC. We found that NCOA6 plays an important role in HCC development and has a potential mechanism of action. Establishing an NCOA6-related miRNA signature will help develop novel diagnostic strategies for HCC patients.

Circulating tumor cell associated white blood cell cluster as a biomarker for metastasis and recurrence in hepatocellular carcinoma.

Background: Recently, an in vivo study demonstrated that circulating tumor cell-associated white blood cell (CTC-WBC) cluster possess much greater potential than single CTCs. We aim to explore the correlation between the CTC-WBC cluster and the clinicopathological characteristics of hepatocellular carcinoma (HCC) patients to seek novel biomarkers for HCC metastasis and recurrence. Methods: We retrospectively analyzed 136 HCC patients from October 2014 to March 2020 who received CTC tests using the CanPatrol CTC enrichment technique. The correlation between the clinical features and total CTCs, EMT-CTCs, and CTC-WBC cluster were analyzed by a chi-square test. The ROC curves were simulated for evaluating the diagnostic performance of CTC parameters in HCC metastasis. Patients were followed up from February 2015 to November 2021, and the relapse-free survival (RFS) was analyzed using the Kaplan-Meier curve. Results: A total of 93.4% (127/136) and 31.6% (43/136) of HCC patients had detectable CTCs and CTC-WBC clusters. Baseline CTC-WBC cluster was closely correlated with microvascular invasion, portal vein tumor thrombus, and extrahepatic metastasis in pre-treatment HCC patients (P <0.05). The simulated ROC curves presented an AUC of 0.821 for the CTC-WBC cluster (sensitivity of 90.0% and specificity of 93.7%) in discriminating metastasis from non-metastatic HCC, which was higher than that for total CTCs (0.718) and EMT-CTCs (0.716). Further follow-up analysis showed that compared to the CTC-WBC cluster negative group (<1/5 ml), patients in the CTC-WBC cluster positive group (≥1/5 ml) presented an increased relapse ratio (60.0% versus 17.9%) and shorter RFS (22.9 versus 53.8 months). Dynamic analysis of CTCs parameters showed that total CTC level, EMT-CTCs proportion, and CTC-WBC cluster were decreased after microwave ablation treatment, while CTC-WBC cluster increased on average 10 months in advance of imaging (MRI) diagnosed recurrence. Conclusion: The CTC-WBC cluster is a promising biomarker for the metastasis diagnosis and prognosis of HCC metastasis. Dynamic monitoring of the CTC-WBC cluster is an effective method for early detection and intervention of HCC recurrence and metastasis.

Chinese expert consensus on conversion therapy for hepatocellular carcinoma (2021 edition).

Recent advances in systemic and locoregional treatments for patients with unresectable or advanced hepatocellular carcinoma (HCC) have resulted in improved response rates. This has provided an opportunity for selected patients with initially unresectable HCC to achieve adequate tumor downstaging to undergo surgical resection, a 'conversion therapy' strategy. However, conversion therapy is a new approach to the treatment of HCC and its practice and treatment protocols are still being developed. Review the evidence for conversion therapy in HCC and develop consensus statements to guide clinical practice. Evidence review: Many research centers in China have accumulated significant experience implementing HCC conversion therapy. Preliminary findings and data have shown that conversion therapy represents an important strategy to maximize the survival of selected patients with intermediate stage to advanced HCC; however, there are still many urgent clinical and scientific challenges for this therapeutic strategy and its related fields. In order to summarize and learn from past experience and review current challenges, the Chinese Expert Consensus on Conversion Therapy for Hepatocellular Carcinoma (2021 Edition) was developed based on a review of preliminary experience and clinical data from Chinese and non-Chinese studies in this field and combined with recommendations for clinical practice. Sixteen consensus statements on the implementation of conversion therapy for HCC were developed. The statements generated in this review are based on a review of clinical evidence and real clinical experience and will help guide future progress in conversion therapy for patients with HCC.

Histone Acetylation Regulator-Mediated Acetylation Patterns Define Tumor Malignant Pathways and Tumor Microenvironment in Hepatocellular Carcinoma.

Background: Histone acetylation modification is one of the most common epigenetic methods used to regulate chromatin structure, DNA repair, and gene expression. Existing research has focused on the importance of histone acetylation in regulating tumorigenicity, tumor progression, and tumor microenvironment (TME) but has not explored the potential roles and interactions of histone acetylation regulators in TME cell infiltration, drug sensitivity, and immunotherapy. Methods: The mRNA expression and genetic alterations of 36 histone acetylation regulators were analyzed in 1599 hepatocellular carcinoma (HCC) samples. The unsupervised clustering method was used to identify the histone acetylation patterns. Then, based on their differentially expressed genes (DEGs), an HAscore model was constructed to quantify the histone acetylation patterns and related subtypes of individual samples. Lastly, the relationship between HAscore and transcription background, tumor clinical features, characteristics of TME, drug response, and efficacy of immunotherapy were analyzed. Results: We identified three histone acetylation patterns characterized by high, medium, and low HAscore. Patients with HCC in the high HAscore group experienced worse overall survival time, and the cancer-related malignant pathways were more active in the high HAscore group, comparing to the low HAscore group. The high HAscore group was characterized by an immunosuppressive subtype because of the high infiltration of immunosuppressive cells, such as regulatory T cells and myeloid-derived suppressor cells. Following validation, the HAscore was highly correlated with the sensitivity of anti-tumor drugs; 116 therapeutic agents were found to be associated with it. The HAscore was also correlated with the therapeutic efficacy of the PD-L1 and PD-1 blockade, and the response ratio was significantly higher in the low HAscore group. Conclusion: To the best of our knowledge, our study is the first to provide a comprehensive analysis of 36 histone acetylation regulators in HCC. We found close correlations between histone acetylation patterns and tumor malignant pathways and TME. We also analyzed the therapeutic value of the HAscore in targeted therapy and immunotherapy. This work highlights the interactions and potential clinical utility of histone acetylation regulators in treatment of HCC and improving patient outcomes.

TGF-ß1 induced deficiency of linc00261 promotes epithelial-mesenchymal-transition and stemness of hepatocellular carcinoma via modulating SMAD3.

Emerging evidence suggests that long non-coding RNAs (lncRNAs) play important roles in the metastasis and recurrence of hepatocellular carcinoma (HCC). A kinds of lncRNAs were found to be involved in regulating epithelial-mesenchymal transition (EMT) or stem-like traits in human cancers, however, the molecular mechanism and signaling pathways targeting EMT and stemness remains largely unknown. Previously, we found that linc00261 was down-regulated in HCC and associated with multiple worse clinical pathological parameters and poor prognosis. Here, we show that linc00261 was down-regulated in TGF-ß1 stimulated cells, and forced expression of linc00261 attenuated EMT and stem-like traits in HCC. Linc00261 also inhibited the tumor sphere forming in vitro and decreased the tumorigenicity in vivo. Furthermore, we revealed that linc00261 suppressed the expression and phosphorylation of SMAD3 (p-SMAD3), which could be core transcriptional modulator in TGF-ß1 signaling mediated EMT and the acquisition of stemness traits. A negative correlation between linc00261 and p-SMAD3 was determined in HCC samples. Conclusion: Our study revealed that linc00261 suppressed EMT and stem-like traits in HCC cells by inhibiting TGF-ß1/SMAD3 signaling.

CMTM6 promotes migration, invasion, and EMT by interacting with and stabilizing vimentin in hepatocellular carcinoma cells.

BACKGROUND: CKLF like MARVEL transmembrane domain containing 6 (CMTM6) has been associated with the development in many kinds of cancers. However, the roles of CMTM6 in hepatocellular carcinoma (HCC) are largely unknown. Thus, the present study aimed to investigate the function of CMTM6 in HCC. METHODS: We analysed CMTM6 levels and functions using human HCC cell lines, paired HCC and adjacent non-tumorous tissues, and a tissue microarray. CMTM6 expression was silenced using short hairpin RNAs and its was overexpressed from a lentivirus vector. CMTM6 mRNA and protein levels were determined using quantitative real-time reverse transcription PCR and western blotting, respectively. Proliferation, colony formation, migration, and invasion were assessed using a Cell counting kit-8, colony formation, wound-healing, and Matrigel invasion assays, respectively. Immunohistochemistry was used to score the expression of CMTM6 in tissue samples. The localization and binding partners of CMTM6 were investigated using immunofluorescence and coimmunoprecipitation experiments, respectively. A mouse xenograft model was used for in vivo studies. RESULTS: Compared with that in adjacent, non-cancerous tissue, Here, CMTM6 levels were increased in HCC tissue samples. Silencing of CMTM6 suppressed the proliferation, migration, and invasion of HCC cells. Conversely, CMTM6 overexpression enhanced HCC cell invasion, migration, and proliferation. Mechanistically, CMTM6 physically interacts with and stabilizes vimentin, thus inducing epithelial-mesenchymal transition (EMT), which promotes proliferation, migration and invasion. Importantly, in HCC tissues, CMTM6 expression correlated positively with vimentin levels. Poor prognosis of HCC was associated significantly with higher CMTM6 expression. CONCLUSIONS: CMTM6 has an important function in HCC proliferation, migration, and invasion, via its interaction with and stabilization of vimentin. CMTM6 might represent a potential biomarker and therapeutic target to treat HCC.

Epigenetically silenced linc00261 contributes to the metastasis of hepatocellular carcinoma via inducing the deficiency of FOXA2 transcription.

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. In recent decades, long non-coding RNAs (lncRNAs) have attracted increasing attention and have been reported to play important roles in human cancers, making them ideal candidates for precise disease assessment and treatment. Our previous study found that the loss of linc00261 was significantly correlated with the malignant biological behaviors of HCC, particularly MVI, and serves as an excellent independent prognostic factor for recurrence-free survival. In this study, our in-depth research demonstrated that linc00261 inhibits epithelial-mesenchymal transition (EMT) in liver cancer cells, thereby suppressing migration, invasion, and the formation of lung metastatic lesions. Moreover, linc00261 and its neighbor gene FOXA2 were positively correlated in HCC, the gain- and loss-of-function analyses indicated that linc00261 transcriptionally promotes the expression of FOXA2. Additionally, bioinformatic analysis and rescue assays confirmed that linc00261 partially suppresses migration, invasion, and EMT by upregulating FOXA2 expression. Molecular mechanism studies showed that linc00261 transcriptionally upregulates FOXA2 in cis by recruiting SMAD3. Finally, we identified EZH2 is responsible for linc00261 transcription repression via modulating trimethylation of H3K27 at Lys27 (H3K27Me3), both EZH2 and H3K27Me3 were negatively correlated with linc00261 expression in HCC. In conclusion, these findings demonstrated a crucial role of linc00261 in HCC metastasis, and that EZH2/linc00261/FOXA2 axis might reveal potential prognostic factors and be applied as therapeutic targets for HCC metastasis.

Deficiency of pseudogene UPAT leads to hepatocellular carcinoma progression and forms a positive feedback loop with ZEB1.

Hepatocellular carcinoma (HCC) is a common disease worldwide. Accumulating reports have evidenced the internal connection between epithelial-mesenchymal transition (EMT) and cancer stem cells (CSCs), as well as their significance in metastasis and post-operative recurrence. In this study, we investigated an interesting ubiquitin-proteasome pathway associated pseudogene of AOC4, also known as UPAT, and showed that it was downregulated in 39.78% (37/93) of patients with hepatitis B virus (HBV)-related HCC. Downregulation of UPAT was associated with multiple worse clinicopathological parameters, as well as decreased recurrence-free survival (RFS). In vitro and in vivo assays found that overexpression of UPAT significantly suppressed cellular migration, invasion, EMT processes, and CSC properties. Mechanistic studies showed that UPAT promoted ZEB1 degradation via a ubiquitin-proteasome pathway and, in contrast, ZEB1 transcriptionally suppressed UPAT by binding to multiple E-box (CACCTG) elements in the promoter region. Moreover, UPAT was negatively correlated with ZEB1 protein in HCC tissues, their combined expression discriminated RFS outcomes for patients with HBV-related HCC. These data on the UPAT-ZEB1 circuit-mediated pathway will further knowledge on EMT and CSCs, and may help to develop novel therapeutic approaches for the prevention of HCC metastasis.

Stability and applicability of the leaf value model for variable nitrogen application based on SPAD value in rice.

Many fertilization models have been created to scientifically determine the amount of fertilization. With the same purpose, we constructed a nitrogen (N) application model, the leaf value model, which can make N fertilizer decisions in a timely, fast and nondestructive manner during rice planting. However, only one area (A1, Jiuzhou Town, Xixiu District, Guizhou Province) and one cultivar (Qyou6) were involved in the construction of the leaf value model. Its stability and applicability could not be well evaluated. Thus, we chose another area (A2, Jiuzhou Town, Huangping County, Guizhou Province) in Guizhou Province and carried out the experiment by using four cultivars (Nie5you5399, Qyou6, Yixiangyou2115 and Zhongzheyou8) for the leaf value model construction. Compared with the average value of apparent total N uptake (Nz) obtained in 2 years in the A1 area, that in the Qyou6 leaf value model in the A2 area increased by 12%, reaching 635.72 kg ha-1, whereas the corresponding target yield changed slightly, reaching 10,999.90 kg ha-1. Simultaneously, the linear relationship between several good SPAD value-derived indexes (Ys) and apparent N supply of the field (Nx) was still significant or extremely significant in the Qyou6 leaf value model. Compared with the A1 area, it slightly differed, and the R2 of SPADL1 was higher than that of SPADL3×L4/mean. In the leaf value model of the other three cultivars, the relationship between yield and Nx and that between Ys and Nx were significant or extremely significant. The Nz of Yixiangyou2115 and Zhongzheyou8 (618.33 and 617.76 kg ha-1) were close to that of Qyou6 and the corresponding target yields were 10313.36 and 10301.99 kg ha-1, respectively. The Nz and target yield of Nie5you5399 were lowest at 546.63 and 10680.24 kg ha-1, respectively. In general, this study showed that relationships used in the construction of leaf value model had certain stability and applicability to difference areas and cultivars. The leaf value model can be considered in N fertilizer decision-making of rice planting management.

Actual long-term survival in HCC patients with portal vein tumor thrombus after liver resection: a nationwide study.

BACKGROUND: Liver resection for hepatocellular carcinoma (HCC) patients with portal vein tumor thrombus (PVTT) offers a chance of cure, although survival is often limited. The actual 3-year survival and its associated prognostic factors have not been reported. METHODS: A nationwide database of HCC patients with PVTT who underwent liver resection with 'curative' intent was analyzed. The clinicopathologic characteristics, the perioperative, and survival outcomes for the actual long-term survivors were compared with the non-long-term survivors (patients who died within 3 years of surgery). Univariable and multivariable regression analyses were performed to identify predictive factors associated with long-term survival outcomes. RESULTS: The study included 1590 patients with an actuarial 3-year survival of 16.6%, while the actual 3-year survival rate was 11.7%. There were 171 patients who survived for at least 3 years after surgery and 1290 who died within 3 years of surgery. Multivariable regression analysis revealed that total bilirubin > 17.1 µmol/l, AFP > 400 ng/ml, types of hepatectomy, extent of PVTT, intraoperative blood loss > 400 ml, tumor diameter > 5 cm, tumor encapsulation, R0 resection, liver cirrhosis, adjuvant TACE, postoperative early recurrence (< 1 year), and recurrence treatments were independent prognostic factors associated with actual long-term survival. CONCLUSION: One in nine HCC patients with PVTT reached the long-term survival milestone of 3 years after resection. Major hepatectomy, controlling intraoperative blood loss, R0 resection, adjuvant TACE, and 'curative' treatment for initial recurrence should be considered for patients to achieve better long-term survival outcomes.

MTR4 drives liver tumorigenesis by promoting cancer metabolic switch through alternative splicing.

The metabolic switch from oxidative phosphorylation to glycolysis is required for tumorigenesis in order to provide cancer cells with energy and substrates of biosynthesis. Therefore, it is important to elucidate mechanisms controlling the cancer metabolic switch. MTR4 is a RNA helicase associated with a nuclear exosome that plays key roles in RNA processing and surveillance. We demonstrate that MTR4 is frequently overexpressed in hepatocellular carcinoma (HCC) and is an independent diagnostic marker predicting the poor prognosis of HCC patients. MTR4 drives cancer metabolism by ensuring correct alternative splicing of pre-mRNAs of critical glycolytic genes such as GLUT1 and PKM2. c-Myc binds to the promoter of the MTR4 gene and is important for MTR4 expression in HCC cells, indicating that MTR4 is a mediator of the functions of c-Myc in cancer metabolism. These findings reveal important roles of MTR4 in the cancer metabolic switch and present MTR4 as a promising therapeutic target for treating HCC.

MicroRNA-214 suppresses cell proliferation and migration and cell metabolism by targeting PDK2 and PHF6 in hepatocellular carcinoma.

MiR-214 has been reported to act as a tumor suppressor or oncogene involved in various malignancies. However, the biological functions and molecular mechanisms of miR-214 in hepatocellular carcinoma (HCC) still remain unclear. Previous studies suggest that pyruvate dehydrogenase kinase 2 (PDK2) and plant homeodomain finger protein 6 (PHF6) may be involved in some tumor cell proliferation and migration. Therefore, we studied the relationship between PDK2/PHF6 and miR-214. The expression of miR-214, PDK2, and PHF6 was determined by quantitative real-time polymerase chain reaction in HCC tissues and cell lines. The Luciferase reporter assay was used to confirm the interaction between miR-214 and PDK2/PHF6. Cell proliferation, apoptosis, and migration were evaluated by cell counting kit-8 assay, flow cytometry, and transwell assay, respectively. The expressions levels of α-smooth muscle actin (α-SMA) and E-cadherin were detected via immunofluorescence assay. Here, we found that the expression of miR-214 decreased in HCC and was negatively correlated with PDK2 and PHF6. Moreover, PDK2 and PHF6 were the direct targets of miR-214 in HCC cells. Functional analysis showed that knockdown of PDK2 or PHF6 as well as miR-214 overexpression significantly suppressed cell proliferation and migration in HCC cells. Furthermore, we found that the suppression of cell proliferation and migration through PDK2 or PHF6 knockdown could be partially reversed by miR-214 down-regulation. Moreover, we demonstrated a decrease of mesenchymal cell marker α-SMA and increase of the epithelial marker E-cadherin after miR-214 overexpression, PDK2 knockdown or PHF6 knockdown, respectively, which also suggested that cell proliferation and migration were suppressed. Additionally, lactate and pyruvic acid production experiments confirmed miR-214 could suppress the HCC cell lactate and pyruvic acid levels by down-regulating PDK2/PHF6. In conclusion, MiR-214 may act as a tumor suppressor gene, presenting its suppressive role in cell proliferation and migration of HCC cells by targeting PDK2 and PHF6, and might provide a potential therapy target for patients with HCC.

[Antiviral and antifibrotic therapies reduce occurrence of hepatocellular carcinoma in patients with chronic hepatitis B and liver fibrosis: a 144-week prospective cohort study].

OBJECTIVE: To compare the efficacy and safety of different antiviral and antifibrotic regimens in patients with chronic hepatitis B (CHB) and hepatic fibrosis and the incidence of hepatocellular carcinoma (HCC) associated with these therapies. METHODS: A total of 840 patients with CHB and concurrent hepatic fibrosis, who received antiviral therapy in Nanfang Hospital between June, 2010 and June, 2018, were enrolled in this follow-up cohort study. The patients were assigned to 3 cohorts matched for gender, age (difference≤5 years), HBeAg status and liver stiffness measurement (LSM) for treatment with one of the 3 antiviral drugs, namely entecavir, tenofovir dipivoxil and adefovir dipivoxil; each cohort was divided into 2 groups, with one of the groups having a combined treatment with Fufang Biejiaruangan tablet. The cumulative negative conversion rate of HBV DNA, normalization rate of ALT, hepatic fibrosis regression and the incidence of HCC were compared among the 3 cohorts and across the 6 groups at 144 weeks. RESULTS: A total of 749 patients were available to follow-up at 144 weeks. Compared with the baseline data, the cumulative negative conversion rate of HBV DNA increased gradually and the abnormal rate of ALT decreased significantly over time during the treatment in all the 6 groups (all P < 0.001). Compared with the any of the antiviral drugs used alone, the combined treatments all resulted in significantly better antifibrotic effects (χETV cohort2=11.345, χTDF cohort2=10.160, χADV cohort2=6.358; all P < 0.05). At 144 weeks, the incidence of HCC were 2.2%, 1.7%, 1.7% and 3.3% in enecavir group, enecavir with Biejiaruangan tablet group, adefovir group, and adefovir with Biejiaruangan tablet group, respectively, showing no significant difference between the two cohorts (4 groups; χ2=6.813, P=0.138). None of the patients in the 2 groups with tenofovir treatment had HCC by the end of the observation. CONCLUSIONS: Antiviral therapy combined with antifibrotic therapy can effectively reverse hepatic fibrosis and reduce the incidence of HCC in patients with CHB; among the 3 antiviral drugs, tenofovir dipivoxil can be a better option for reducing the incidence of HCC in these patients.

MALAT1 functions as a competing endogenous RNA to regulate SMAD5 expression by acting as a sponge for miR-142-3p in hepatocellular carcinoma.

BACKGROUND: Long non-coding RNAs are involved in the pathology of various tumors, including hepatocellular carcinoma. The expression of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is increased in numerous types of tumors and is involved in tumor cell proliferation, migration, invasion and apoptosis. MALAT1 level was reported to be upregulated in hepatocellular carcinoma tissues, but its roles and the specific molecular mechanisms are still unclear. METHODS: The expression of MALAT1 and miR-142-3p in hepatocellular carcinoma tissues, cell lines and adjacent non-tumor tissues was assessed by Q-PCR. The putative-binding sites between MALAT1 and miR-142-3p were predicted by bioinformatics analysis. The expression of MALAT1 in HepG2 and SMMC-7721 cells was knocked down by transfection with MALAT1 siRNAs. Cell viability was assessed by the Cell Counting Kit-8 (CCK-8) assay after the indicated transfection in HepG2 and SMMC-7721 cells. Cell proliferation was assessed by EdU assay, and cell apoptosis was explored by flow cytometry. The migration and invasion potency of HepG2 and SMMC-7721 cells was assessed by the cell migration assay and matrigel invasion assay. Protein level of vimentin, E-cadherin and SMAD5 were assessed by Western blot. RESULTS: Overexpressed MALAT1 acts as a competing endogenous RNA sponge for miR-142-3p in hepatocellular carcinoma. The knockdown of MALAT1 inhibited the proliferation, migration, invasion, and epithelial cell-to-mesenchymal transition (EMT), and promoted apoptosis of hepatocellular carcinoma cells via miR-142-3p. MiR-142-3p inhibited cell proliferation, migration, invasion and EMT, and promoted the cell apoptosis by targeting SMAD5 in hepatocellular carcinoma. MALAT1 promoted tumor growth by regulating the expression of miR-142-3p in vivo. CONCLUSION: MALAT1 promoted cell proliferation, migration, and invasion of hepatocellular carcinoma cells by antagonizing miR-142-3p.

Frizzled 2-induced epithelial-mesenchymal transition correlates with vasculogenic mimicry, stemness, and Hippo signaling in hepatocellular carcinoma.

Prior observation has indicated that Frizzled 2 (FZD2)-induced epithelial-mesenchymal transition (EMT) could be a key step in metastasis and early recurrence of hepatocellular carcinoma (HCC). However, the mechanism underlying tumor development and progression due to aberrant FZD2 expression is poorly defined. Here, we provide evidence that FZD2 is a driver for EMT, cancer stem cell properties, and vasculogenic mimicry (VM) in HCC. We found that FZD2 was highly expressed in two cohorts of Chinese hepatitis B virus-related HCC patients, and that high FZD2 expression was associated with poor prognosis. Concerning the mechanism, gain- and loss-of-function experiments showed the oncogenic action of FZD2 in HCC cell proliferation, apoptosis, migration, and invasion. Further investigations in vitro and in vivo suggested that FZD2 promotes the EMT process, enhances stem-like properties, and confers VM capacity to HCC cells. Notably, integrative RNA sequencing analysis of FZD2-knockdown cells indicated the enrichment of Hippo signaling pathway. Taken together, our data suggest for the first time that FZD2 could promote clinically relevant EMT, CD44+ stem-like properties, and the VM phenotype in HCC involving a potential Hippo signaling pathway-dependent mechanism, and should be considered as a promising therapeutic target for the treatment of HCC.