SLFN11 inhibits hepatocellular carcinoma tumorigenesis and metastasis by targeting RPS4X via mTOR pathway

Evidence of promoting effects of 6:2 Cl-PFESA on hepatocellular carcinoma proliferation in humans: An ideal alternative for PFOS in terms of environmental health?

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are synthetic chemicals, encompassing compounds like perfluorooctane sulfonate (PFOS), which have widespread applications across various industries, including food packaging and firefighting. In recent years, China has increasingly employed 6:2 Cl-PFESA as an alternative to PFOS. Although the association between PFAS exposure and hepatocellular carcinoma (HCC) has been demonstrated, the underlying mechanisms that promote HCC proliferation are uncleared. Therefore, we aimed to investigate the effects and differences of PFOS and 6:2 Cl-PFESA on HCC proliferation through in vivo and in vitro tumor models. Our results reveal that both PFOS and 6:2 Cl-PFESA significantly contribute to HCC proliferation in vitro and in vivo. Exposure led to reduced population doubling times, enlarged cell colony sizes, enhanced DNA synthesis efficiency, and a higher proportion of cells undergoing mitosis. Furthermore, both PFOS and 6:2 Cl-PFES) have been shown to activate the PI3K/AKT/mTOR signaling pathway and inhibit necroptosis. This action consequently enhances the proliferation of HCC cells. Our phenotypic assay findings suggest that the tumorigenic potential of 6:2 Cl-PFESA surpasses that of PFOS; in a subcutaneous tumor model using nude mice, the mean tumor weight for the 6:2 Cl-PFESA-treated cohort was 2.33 times that observed in the PFOS cohort (p < 0.01). Despite 6:2 Cl-PFESA being considered a safer substitute for PFOS, the pronounced effects of this chemical on HCC cell growth warrant a thorough assessment of hepatotoxicity risks linked to its usage.

Exercise potentially prevents colorectal cancer liver metastases by suppressing tumor epithelial cell stemness via RPS4X downregulation

Background

Colorectal cancer (CRC) is the third most prevalent tumor globally. The liver is the most common site for CRC metastasis, and the involvement of the liver is a common cause of death in patients with late-stage CRC. Consequently, mitigating CRC liver metastasis (CRLM) is key to improving CRC prognosis and increasing survival. Exercise has been shown to be an effective method of improving the prognosis of many tumor types. However, the ability of exercise to inhibit CRLM is yet to be thoroughly investigated.

Methods

The GSE157600 and GSE97084 datasets were used for analysis. A pan-cancer dataset which was uniformly normalized was downloaded and analyzed from the UCSC database: TCGA, TARGET, GTEx (PANCAN, n = 19,131, G = 60,499). Several advanced bioinformatics analyses were conducted, including single-cell sequencing analysis, correlation algorithm, and prognostic screen. CRC tumor microarray (TMA) as well as cell/animal experiments are used to further validate the results of the analysis.

Results

The greatest variability was found in epithelial cells from the tumor group. RPS4X was generally upregulated in all types of CRC, while exercise downregulated RPS4X expression. A lowered expression of RPS4X may prolong tumor survival and reduce CRC metastasis. RPS4X and tumor stemness marker-CD44 were highly positively correlated and knockdown of RPS4X expression reduced tumor stemness both in vitro and in vivo.

Conclusion

RPS4X upregulation may enhance CRC stemness and increase the odds of metastasis. Exercise may reduce CRC metastasis through the regulation of RPS4X.

Impulsivity and aggression in alcohol withdrawal syndrome is modulated by the interaction of ZNF804A and mTOR polymorphism

Alcohol withdrawal syndrome (AWS) is a poorly studied phenotype of alcohol use disorder. Understanding the relationship between allelic interactions and AWS-related impulsivity and aggression could have significant implications. This study aimed to investigate the main and interacting effects of ZNF804A and mTOR on impulsivity and aggression during alcohol withdrawal. 446 Chinese Han adult males with alcohol dependence were included in the study. Impulsivity and aggression were assessed, and genomic DNA was genotyped. Single gene analysis showed that ZNF804A rs1344706 (A allele/CC homozygote) and mTOR rs1057079 (C allele/TT homozygote) were strongly associated with AWS-related impulsivity and aggression. In the allelic group, MANOVA revealed a significant gene x gene interaction, suggesting that risk varied systematically depending on both ZNF804A and mTOR alleles. Additionally, a significant interactive effect of ZNF804A rs1344706 and mTOR rs7525957 was found on motor impulsivity and physical aggression, and the ZNF804A rs1344706 gene variant had significant effects on motor impulsivity and physical aggression only in mTOR rs7525957 TT homozygous carriers. The study showed that specific allelic combinations of ZNF804A and mTOR may have protective or risk-enhancing effects on AWS-related impulsivity and aggression.

CREB3L4 promotes hepatocellular carcinoma progression and decreases sorafenib chemosensitivity by promoting RHEB-mTORC1 signaling pathway

This study was designed to explore the roles of CREB3L4 in the pathogenesis and drug resistance of hepatocellular carcinoma (HCC). The proliferation of HCC lines was determined in the presence of CREB3L4 over-expression and silencing. Chromatin immunoprecipitation (ChIP) assay and dual-luciferase reporter assay were performed to screen the potential target of CREB3L4 on mTORC1. Xenografted tumor model was established to define the regulatory effects of CREB3L4 in the tumorigenesis. Then we evaluated the roles of CREB3L4 in chemosensitivity to sorafenib treatment. CREB3L4 significantly induced the HCC cell proliferation by modulating the activation of mTROC1-S6K1 signaling pathway via binding with RHEB promoter. Moreover, CREB3L4 dramatically inhibited the chemosensitivity to sorafenib treatment via up-regulating RHEB-mTORC1 signaling. CREB3L4 promoted HCC progression and decreased its chemosensitivity to sorafenib through up-regulating RHEB-mTORC1 signaling pathway, indicating a potential treatment strategy for HCC through targeting CREB3L4.

Environment relevant exposure of perfluorooctanoic acid accelerates the growth of hepatocellular carcinoma cells through mammalian target of rapamycin (mTOR) signal pathway

Perfluorooctanoic acid (PFOA), a synthetic alkyl chain fluorinated compound, has emerged as a persistent organic pollutant of grave concern, casting a shadow over both ecological integrity and humans. Its insidious presence raises alarms due to its capacity to bioaccumulate within the human liver, potentially paving the treacherous path toward liver cancer. Yet, the intricate mechanisms underpinning PFOA's role in promoting the growth of hepatocellular carcinoma (HCC) remain shrouded in ambiguity. Here, we determined the proliferation and transcription changes of HCC after PFOA exposure through integrated experiments including cell culture, nude mice tests, and colony-forming assays. Based on our findings, PFOA effectively promotes the proliferation of HCC cells within the experimental range of concentrations, both in vivo and in vitro. The proliferation efficiency of HCC cells was observed to increase by approximately 10% due to overexposure to PFOA. Additionally, the cancer weight of tumor-bearing nude mice increased by 87.0% (p < 0.05). We systematically evaluated the effects of PFOA on HCC cells and found that PFOA's exposure can selectively activate the PI3K/AKT/mTOR/4E-BP1 signaling pathway, thereby playing a pro-cancer effect on HCC cells Confirmation echoed through western blot assays and inhibitor combination analyses. These insights summon a response to PFOA's dual nature as both an environmental threat and a promoter of liver cancer. Our work illuminates the obscured domain of PFOA-induced hepatoxicity, shedding light on its ties to hepatocellular carcinoma progression.

Identification of new drug candidates against Trichomonas gallinae using high-throughput screening

Trichomonas gallinae is a protozoan parasite that is the causative agent of trichomoniasis, and infects captive and wild bird species throughout the world. Although metronidazole has been the drug of choice against trichomoniasis for decades, most Trichomonas gallinae strains have developed resistance. Therefore, drugs with new modes of action or targets are urgently needed. Here, we report the development and application of a cell-based CCK-8 method for the high-throughput screening and identification of new inhibitors of Trichomonas gallinae as a beginning point for the development of new treatments for trichomoniasis. We performed the high-throughput screening of 173 anti-parasitic compounds, and found 16 compounds that were potentially effective against Trichomonas gallinae. By measuring the median inhibitory concentration (IC50) and median cytotoxic concentration (CC50), we identified 3 potentially safe and effective compounds against Trichomonas gallinae: anisomycin, fumagillin, and MG132. In conclusion, this research successfully established a high-throughput screening method for compounds and identified 3 new safe and effective compounds against Trichomonas gallinae, providing a new treatment scheme for trichomoniasis.

Baicalin inhibits the replication of the hepatitis B virus by targeting TRIM25

Objective

Baicalin, which is a key bioactive constituent obtained from Scutellaria baicalensis, has been utilized in traditional Chinese medicine for many centuries. Although it has been reported that Baicalin (BA) can inhibit the replication of the Hepatitis B virus (HBV), the exact mechanism behind this process remains unclear. Interferon-stimulated genes (ISGs) are crucial in the process of antiviral defense. We aim to investigate whether BA can regulate the expression of ISGs, and thereby potentially modulate the replication of HBV.

Methods

The study involved the use of CRISPR/Cas9 technology to perform knockout experiments on TRIM25 and IFIT3 genes. The expression of these genes was confirmed through techniques such as immunoblotting or Q-PCR. The levels of HBsAg and HBeAg were measured using ELISA, and the expression of interferon-stimulated genes was detected using a luciferase assay.

Results

It is interesting to note that several ISGs belonging to the TRIM family, including TRIM5, TRIM25, and TRIM14, were induced after BA treatment. On the other hand, members of the IFIT family were reduced by BA stimulation. Additionally, BA-mediated HBV inhibition was found to be significantly restored in HepG2 cells where TRIM25 was knocked out. Additional research into the mechanism of action of BA found that prolonged treatment with BA activated the JAK/STAT signaling pathway while simultaneously inhibiting the NF-kB pathway.

Conclusion

The findings of our study indicate that TRIM25 has a significant impact on the regulation of HBV replication following BA treatment, providing additional insight into the mechanisms by which BA exerts its antiviral effects.

Analysis of the Prognostic Potential of Schlafen 11, Programmed Death Ligand 1, and Redox Status in Colorectal Cancer Patients

The Schlafen 11 (SLFN11) protein has recently emerged as pivotal in DNA damage conditions, with predictive potential for tumor response to cytotoxic chemotherapies. Recent discoveries also showed that the programmed death ligand 1 (PD-L1) protein can be found on malignant cells, providing an immune evasion mechanism exploited by different tumors. Additionally, excessive generation of free radicals, redox imbalance, and consequential DNA damage can affect intestinal cell homeostasis and lead to neoplastic transformation. Therefore, our study aimed to investigate the significance of SLFN11 and PD-L1 proteins and redox status parameters as prognostic biomarkers in CRC patients. This study included a total of 155 CRC patients. SLFN11 and PD-L1 serum levels were measured with ELISA and evaluated based on redox status parameters, sociodemographic and clinical characteristics, and survival. The following redox status parameters were investigated: spectrophotometrically measured superoxide dismutase (SOD), sulfhydryl (SH) groups, advanced oxidation protein products (AOPP), malondialdehyde (MDA), pro-oxidant-antioxidant balance (PAB), and superoxide anion (O2•-). The prooxidative score, antioxidative score, and OXY-SCORE were also calculated. The results showed significantly shorter survival in patients with higher OXY-SCOREs and higher levels of serum SLFN11, while only histopathology-analysis-related factors showed significant prognostic value. OXY-SCORE and SLFN11 levels may harbor prognostic potential in CRC patients.

LncRNA MEG3 Inhibits Tumor Progression by Modulating Macrophage Phenotypic Polarization via miR-145-5p/DAB2 Axis in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is the predominant histological type of primary liver cancer, which ranks sixth among the most common human tumors. Tumor-associated macrophages (TAMs) are an important component of tumor microenvironment (TME) and the M2 macrophage polarization substantially contributes to tumor growth and metastasis. Long non-coding RNA (lncRNA) MEG3 was reported to restrain HCC development. However, whether MEG3 regulates macrophage phenotypic polarization in HCC remains unclear.

Methods

Bone marrow derived macrophages (BMDMs) were treated with LPS/IFNγ and IL4/IL13 to induce the M1 and M2 macrophage polarization, respectively. M2-polarized BMDMs were simultaneously transfected with adenovirus vector overexpressing MEG3 (Adv-MEG3). Subsequently, M2-polarized BMDMs were cultured for 24 h with serum-free medium, the supernatants of which were harvested as conditioned medium (CM). HCC cell line Huh7 was cultured with CM for 24 h. F4/80⁺CD68⁺ and F4/80⁺CD206⁺ cell percentages in M1-and M2-polarized BMDMs were calculated using flow cytometry. Huh7 cell migration, invasion and angiogenesis were determined via Transwell assay and tube formation experiment. Nude mice were implanted with Huh7 cells and Adv-MEG3-transfected M2-polarizd BMDMs, and tumor growth and M2 macrophage polarization markers were assessed. The binding between miR-145-5p and MEG3 or disabled-2 (DAB2) was verified by luciferase reporter assay.

Results

MEG3 presented lower expression in HCC tissues than in normal controls, and low expression of MEG3 was correlated to poorer prognosis of HCC patients. MEG3 expression was enhanced during LPS/IFNγ-induced M1 polarization, but was reduced during IL4/IL13-induced M2 polarization. MEG3 overexpression inhibited the expression of M2 polarization markers in both M2-polarized BMDMs and mice. Mechanically, MEG3 bound with miR-145-5p to regulate DAB2 expression. Overexpressing MEG3 suppressed M2 polarization-induced HCC cell metastasis and angiogenesis by upregulating DAB2 and inhibited in vivo tumor growth.

Conclusion

LncRNA MEG3 curbs HCC development by repressing M2 macrophage polarization via miR-145-5p/DAB2 axis.

Degradation of helicase-like transcription factor (HLTF) by β-TrCP promotes hepatocarcinogenesis via activation of the p62/mTOR axis

Helicase-like transcription factor (HLTF) has been found to be involved in the maintenance of genome stability and tumour suppression, but whether its downregulation in cancers is associated with posttranslational regulation remains unclear. Here, we observed that HLTF was significantly downregulated in hepatocellular carcinoma (HCC) tissues and positively associated with the survival of HCC patients. Mechanistically, the decreased expression of HLTF in HCC was attributed to elevated β-TrCP-mediated ubiquitination and degradation. Knockdown of HLTF enhanced p62 transcriptional activity and mammalian target of rapamycin (mTOR) activation, leading to HCC tumourigenesis. Inhibition of mTOR effectively blocked β-TrCP overexpression- or HLTF knockdown-mediated HCC tumourigenesis and metastasis. Furthermore, in clinical tissues, decreased HLTF expression was positively correlated with elevated expression of β-TrCP, p62, or p-mTOR in HCC patients. Overall, our data not only uncover new roles of HLTF in HCC cell proliferation and metastasis, but also reveal a novel posttranslational modification of HLTF by β-TrCP, indicating that the β-TrCP/HLTF/p62/mTOR axis may be a new oncogenic driver involved in HCC development. This finding provides a potential therapeutic strategy for HCC patients by targeting the β-TrCP/HLTF/p62/mTOR axis.

Pulmonary benign metastasizing leiomyoma in patients aged 45 years and younger: clinical features and novelty in treatment

BACKGROUND

Pulmonary benign metastasizing leiomyoma (PBML) is the most common extrauterine spread of uterine leiomyoma, and its biological behavior is traditionally thought to be hormone dependent. Studies on older PBML patients have been previously reported, but limited literature has been published regarding the clinical features and treatment of PBML in young women.

METHODS

A total of 65 cases of PBML in women aged 45 years and younger were reviewed, including 56 cases selected from PubMed and 9 cases from our hospital. The clinical characteristics and management of these patients were analyzed.

RESULTS

The median age of all the patients at diagnosis was 39.0 years. PBML most commonly presented as bilateral solid lesions (60.9%), with other rare imaging manifestations. The median interval time from a pertinent gynecologic procedure to diagnosis was 6.0 years. A total of 16.7% of patients received careful observation, and all achieved stable status in a median follow-up time of 18.0 months. A total of 71.4% of patients were administered anti-estrogen therapies, including surgical castration (33.3%), gonadotropin-releasing hormone analog (23.8%) and anti-estrogen drugs (14.3%). Eight of 42 patients underwent surgical resection of metastatic lesions. Patients who underwent curative surgery for the removal of pulmonary lesions combined with adjuvant anti-estrogen therapies had favorable outcomes compared with those who only underwent surgical resection. The disease control rates of surgical castration, gonadotropin-releasing hormone analog, and anti-estrogen drugs were 85.7%, 90.0%, and 50.0%, respectively. For two patients, sirolimus (rapamycin) achieved successful relief of symptoms and control of pulmonary lesions without lowering hormone levels and causing estrogen deficiency symptoms.

CONCLUSIONS

In the absence of standard treatment guidelines for PBML, maintaining a low-estrogen environment using different kinds of antiestrogen therapies has been the mainstream strategy and has satisfying curative effects. A wait-and-see strategy might be an option, but therapeutic approaches must be contemplated when complications or symptoms progress. For PBML in young women, the negative effect on ovarian function of anti-estrogen treatment, especially surgical castration, should be considered. Sirolimus might be a new treatment option for young PBML patients, especially for those who want to preserve ovarian function.

Single-Cell Transcriptome Analysis Revealed Heterogeneity and Identified Novel Therapeutic Targets for Breast Cancer Subtypes

Breast cancer (BC) is a heterogeneous disease, which is primarily classified according to hormone receptors and HER2 expression. Despite the many advances in BC diagnosis and management, the identification of novel actionable therapeutic targets expressed by cancerous cells has always been a daunting task due to the large heterogeneity of the disease and the presence of non-cancerous cells (i.e., immune cells and stromal cells) within the tumor microenvironment. In the current study, we employed computational algorithms to decipher the cellular composition of estrogen receptor-positive (ER⁺), HER2⁺, ER⁺HER2⁺, and triple-negative BC (TNBC) subtypes from a total of 49,899 single cells' publicly available transcriptomic data derived from 26 BC patients. Restricting the analysis to EPCAM⁺Lin^- tumor epithelial cells, we identified the enriched gene sets in each BC molecular subtype. Integration of single-cell transcriptomic with CRISPR-Cas9 functional screen data identified 13 potential therapeutic targets for ER⁺, 44 potential therapeutic targets for HER2⁺, and 29 potential therapeutic targets for TNBC. Interestingly, several of the identified therapeutic targets outperformed the current standard of care for each BC subtype. Given the aggressive nature and lack of targeted therapies for TNBC, elevated expression of ENO1, FDPS, CCT6A, TUBB2A, and PGK1 predicted worse relapse-free survival (RFS) in basal BC (n = 442), while elevated expression of ENO1, FDPS, CCT6A, and PGK1 was observed in the most aggressive BLIS TNBC subtype. Mechanistically, targeted depletion of ENO1 and FDPS halted TNBC cell proliferation, colony formation, and organoid tumor growth under 3-dimensional conditions and increased cell death, suggesting their potential use as novel therapeutic targets for TNBC. Differential expression and gene set enrichment analysis in TNBC revealed enrichment in the cycle and mitosis functional categories in FDPS^high, while ENO1^high was associated with numerous functional categories, including cell cycle, glycolysis, and ATP metabolic processes. Taken together, our data are the first to unravel the unique gene signatures and to identify novel dependencies and therapeutic vulnerabilities for each BC molecular subtype, thus setting the foundation for the future development of more effective targeted therapies for BC.

Disruption of SLFN11 Deficiency-Induced CCL2 Signaling and Macrophage M2 Polarization Potentiates Anti-PD-1 Therapy Efficacy in Hepatocellular Carcinoma

BACKGROUND & AIMS

The therapeutic effect of immune checkpoint inhibitors (ICIs) is poor in hepatocellular carcinoma (HCC) and varies greatly among individuals. Schlafen (SLFN) family members have important functions in immunity and oncology, but their roles in cancer immunobiology remain unclear. We aimed to investigate the role of the SLFN family in immune responses against HCC.

METHODS

Transcriptome analysis was performed in human HCC tissues with or without response to ICIs. A humanized orthotopic HCC mouse model and a co-culture system were constructed, and cytometry by time-of-flight technology was used to explore the function and mechanism of SLFN11 in the immune context of HCC.

RESULTS

SLFN11 was significantly up-regulated in tumors that responded to ICIs. Tumor-specific SLFN11 deficiency increased the infiltration of immunosuppressive macrophages and aggravated HCC progression. HCC cells with SLFN11 knockdown promoted macrophage migration and M2-like polarization in a C-C motif chemokine ligand 2-dependent manner, which in turn elevated their own PD-L1 expression by activating the nuclear factor-κB pathway. Mechanistically, SLFN11 suppressed the Notch pathway and C-C motif chemokine ligand 2 transcription by binding competitively with tripartite motif containing 21 to the RNA recognition motif 2 domain of RBM10, thereby inhibiting tripartite motif containing 21-mediated RBM10 degradation to stabilize RBM10 and promote NUMB exon 9 skipping. Pharmacologic antagonism of C-C motif chemokine receptor 2 potentiated the antitumor effect of anti-PD-1 in humanized mice bearing SLFN11 knockdown tumors. ICIs were more effective in patients with HCC with high serum SLFN11 levels.

CONCLUSIONS

SLFN11 serves as a critical regulator of microenvironmental immune properties and an effective predictive biomarker of ICIs response in HCC. Blockade of C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 signaling sensitized SLFN11^low HCC patients to ICI treatment.

MLXIPL promotes the migration, invasion, and glycolysis of hepatocellular carcinoma cells by phosphorylation of mTOR

BACKGROUND

Hepatocellular carcinoma (HCC) is associated with a high occurrence, mortality, and poor prognosis. MLX interacting protein like (MLXIPL) is an important regulator of glucolipid metabolism and is involved in tumor progression. We aimed to clarify the role of MLXIPL in HCC and its underlying mechanisms.

METHODS

The level of MLXIPL was predicted using bioinformatic analysis and verified using quantitative real-time PCR (qPCR), immunohistochemical analysis, and western blot. We assessed the effects of MLXIPL on biological behaviors using the cell counting kit-8, colony formation, and Transwell assay. Glycolysis was evaluated using the Seahorse method. The interaction between MLXIPL and mechanistic target of rapamycin kinase (mTOR) was confirmed using RNA immunoprecipitation and co-immunoprecipitation. mTOR expression was detected in HCC cells using qPCR, immunofluorescence analysis, and western blot.

RESULTS

The results showed that MLXIPL levels were elevated in both HCC tissues and HCC cell lines. Knockdown of MLXIPL impeded HCC cell growth, invasion, migration, and glycolysis. Moreover, MLXIPL combined with mTOR to induce phosphorylation of mTOR. Activated mTOR abrogated the effects on cellular processes induced by MLXIPL.

CONCLUSION

MLXIPL promoted the malignant progression of HCC by activating phosphorylation of mTOR, suggesting an important role of the combination of MLXIPL and mTOR in HCC.

PDHB-AS suppresses cervical cancer progression and cisplatin resistance via inhibition on Wnt/β-catenin pathway

Cervical cancer (CC) is the most prevalent gynecological malignancy occurring in the cervix. Long non-coding RNAs (lncRNAs) can act as oncogenes or anti-oncogenes in CC development. Here, we investigated the functional role and detailed mechanism of lncRNA pyruvate dehydrogenase E1 subunit beta antisense (PDHB-AS) in CC. At first, we found that PDHB-AS was significantly down-regulated in CC cells. Besides, overexpression of PDHB-AS repressed CC cell malignant behaviors. HKF-derived exosomes carried miR-4536-5p to CC cells and thereby inhibited PDHB-AS expression. Moreover, PDHB-AS inactivated the Wnt/β-catenin pathway via impeding the nuclear translocation of β-catenin in CC cells. In addition, miR-582-5p could bind with both PDHB-AS and Dickkopf-1 (DKK1). PDHB-AS recruited poly(A) binding protein cytoplasmic 1 (PABPC1) to inhibit Wnt7b expression. PDHB-AS interacted with RNA-binding motif protein X-linked (RBMX) to regulate cisplatin resistance in CC. Finally, we conducted in vivo experiments to confirm that HKF promoted CC tumor growth whereas PDHB-AS suppressed CC tumor growth. Collectively, PDHB-AS plays a tumor-suppressive role in the progression of CC, which suggests the therapeutic potential of PDHB-AS for CC.

Hepatitis Virus and Hepatocellular Carcinoma: Recent Advances

Hepatocellular carcinoma (HCC) remains a global health challenge, causing 600,000 deaths each year. Infectious factors, including hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis D virus (HDV), have long been considered the major risk factors for the development and progression of HCC. These pathogens induce hepatocyte transformation through a variety of mechanisms, including insertional mutations caused by viral gene integration, epigenetic changes, and the induction of long-term immune dysfunction. The discovery of these mechanisms, while advancing our understanding of the disease, also provides targets for new diagnostic and therapeutic approaches. In addition, the discovery and research of chronic HEV infection over the past decade indicate that this common hepatitis virus also seems to have the potential to induce HCC. In this review, we provide an overview of recent studies on the link between hepatitis virus and HCC, as well as new diagnostic and therapeutic approaches to HCC based on these findings. Finally, we also discuss the potential relationship between HEV and HCC. In conclusion, these associations will further optimize the diagnosis and treatment of infection-associated HCC and call for better management policies.

Improving the Transduction Efficiency and Antitumor Effect of Conditionally Replicative Adenovirus by Application of 6-cyclohexyl Methyl-β-D-maltoside

As a tumor-targeting oncolytic adenovirus (Ad), conditionally replicating adenovirus (CRAd) can access the cell interior by binding to coxsackievirus-Ad receptors (CARs) and specifically replicate and destroy cancer cells without lethal effects on normal cells. The transduction efficiency of CRAd is highly dependent on the number of CARs on the cell membrane. However, not all tumor cells highly express CARs; therefore, improving the transduction efficiency of CRAd is beneficial for improving its antitumor effect. In this study, 6-cyclohexyl methyl-β-D-maltoside (6-β-D), as maltoside transfection agent, showed several advantages, including high transfection efficiency, low toxicity, and potential for intensive use and easy operation. With pretreatment of cancer cells with low concentration of 6-β-D (≤5 μg/mL), the transduction efficiency of "model" Ad (eGFP-Ad) was improved 18-fold compared to eGFP-Ad alone. 6-β-D improved the antitumor effect of CRAd while being safe for normal cells, in which treatment with 6-β-D helped the lethal effects of CRAd at a multiplicity-of-infection ratio of 10 (MOI 10) achieve the oncolytic outcomes of MOI 50. This means that if CRAd is combined with 6-β-D, the amount of CRAd used in clinical practice could be greatly reduced without diminishing its curative effect or exposing patients to the potential side effects of high-titer CRAd. Finally, the underlying mechanism of antitumor effect of CRAd + 6-β-D was primarily investigated, and we found that 6-β-D increased the virus's replication in cancer cells at the early stage of infection and activated the apoptosis signaling pathway at the late stage of the cell cycle. This research will provide an effective technical reference for further improving Ad-mediated cancer gene therapy in clinical practice.

RPS24 Is Associated with a Poor Prognosis and Immune Infiltration in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver malignancy, with increased mortality and morbidity. Accumulating evidence suggested that 40S ribosomal protein S24 (RPS24) is related to malignant outcomes and progression. However, the role of RPS24 remains unclear in HCC. The mRNA and protein expression pattern of RPS24 in HCC was explored and confirmed based on the bioinformatics analysis and histological examination. The correlation between RPS24 expression and clinicopathological features, diagnostic value, prognosis, methylation status, and survival were evaluated. Then, we divided the HCC cohort into two groups based on the expression of RPS24, and performed the functional enrichment and immune cells infiltration analysis of RPS24. Furthermore, in vivo and in vitro experiments were performed to investigate the effect of RPS24 on HCC cells. RPS24 was observed to be elevated in HCC samples. RPS24 overexpression or RPS24 promoter methylation contributed to an unfavorable prognosis for HCC patients. The genes in the high RPS24 expression group were mainly enriched in DNA replication, cell cycle E2F targets, and the G2M checkpoint pathway. Moreover, the expression level of RPS24 was significantly related to immune infiltration and immunotherapy response. Our experiments also demonstrated that RPS24 knockdown suppressed the growth of HCC cells and tumor proliferation of the xenograft model. Therefore, RPS24 can be a potential adverse biomarker of HCC prognosis acting through facilitating cell proliferation and the formation of an immunosuppressive microenvironment in HCC. Targeting RPS24 may offer a promising therapeutic option for HCC management.

Hepatitis B virus infection: An insight into the clinical connection and molecular interaction between hepatitis B virus and host extrahepatic cancer risk

The evidence for chronic hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC) occurrence is well established. The hepatocyte epithelium carcinogenesis caused by HBV has been investigated and reviewed in depth. Nevertheless, recent findings from preclinical and observational studies suggested that chronic HBV infection is equally important in extrahepatic cancer occurrence and survival, specifically gastrointestinal system-derived cancers. Immune microenvironment changes (immune-suppressive cytokine infiltration), epigenetic modification (N6-methyladenosine), molecular signaling pathways (PI3K-Akt and Wnt), and serum biomarkers such as hepatitis B virus X (HBx) protein are potential underlying mechanisms in chronic HBV infection-induced extrahepatic cancers. This narrative review aimed to comprehensively summarize the most recent advances in evaluating the association between chronic HBV infection and extrahepatic cancer risk and explore the potential underlying molecular mechanisms in the carcinogenesis induction of extrahepatic cancers in chronic HBV conditions.

Expression of hub genes of endothelial cells in glioblastoma-A prognostic model for GBM patients integrating single-cell RNA sequencing and bulk RNA sequencing

BACKGROUND

This study aimed to use single-cell RNA-seq (scRNA-seq) to discover marker genes in endothelial cells (ECs) and construct a prognostic model for glioblastoma multiforme (GBM) patients in combination with traditional high-throughput RNA sequencing (bulk RNA-seq).

METHODS

Bulk RNA-seq data was downloaded from The Cancer Genome Atlas (TCGA) and The China Glioma Genome Atlas (CGGA) databases. 10x scRNA-seq data for GBM were obtained from the Gene Expression Omnibus (GEO) database. The uniform manifold approximation and projection (UMAP) were used for downscaling and cluster identification. Key modules and differentially expressed genes (DEGs) were identified by weighted gene correlation network analysis (WGCNA). A non-negative matrix decomposition (NMF) algorithm was used to identify the different subtypes based on DEGs, and multivariate cox regression analysis to model the prognosis. Finally, differences in mutational landscape, immune cell abundance, immune checkpoint inhibitors (ICIs)-associated genes, immunotherapy effects, and enriched pathways were investigated between different risk groups.

RESULTS

The analysis of scRNA-seq data from eight samples revealed 13 clusters and four cell types. After applying Fisher's exact test, ECs were identified as the most important cell type. The NMF algorithm identified two clusters with different prognostic and immunological features based on DEGs. We finally built a prognostic model based on the expression levels of four key genes. Higher risk scores were significantly associated with poorer survival outcomes, low mutation rates in IDH genes, and upregulation of immune checkpoints such as PD-L1 and CD276.

CONCLUSION

We built and validated a 4-gene signature for GBM using 10 scRNA-seq and bulk RNA-seq data in this work.

GTPBP4 promotes hepatocellular carcinoma progression and metastasis via the PKM2 dependent glucose metabolism

Guanosine triphosphate binding protein 4 (GTPBP4) is a key regulator of cell cycle progression and MAPK activation. However, how its biological properties intersect with cellular metabolism in hepatocellular carcinoma (HCC) development remains poorly unexplained. Here, high GTPBP4 expression is found to be significantly associated with worse clinical outcomes in patients with HCC. Moreover, GTPBP4 upregulation is paralleled by DNA promoter hypomethylation and regulated by DNMT3A, a DNA methyltransferase. Additionally, both gain- and loss-of-function studies demonstrate that GTPBP4 promotes HCC growth and metastasis in vitro and in vivo. Mechanically, GTPBP4 can induce dimeric pyruvate kinase M2 (PKM2) formation through protein sumoylation modification to promote aerobic glycolysis in HCC. Notably, active GTPBP4 facilitates SUMO1 protein activation by UBA2, and acts as a linker bridging activated SUMO1 protein and PKM2 protein to induce PKM2 sumoylation. Furthermore, SUMO-modified PKM2 relocates from the cytoplasm to the nucleus may also could contribute to HCC progression through activating epithelial-mesenchymal transition (EMT) and STAT3 signaling pathway. Shikonin, a PKM2-specific inhibitor, can attenuate PKM2 dependent HCC glycolytic reprogramming, growth and metastasis promoted by GTPBP4, which offers a promising therapeutic candidate for HCC patients. Our findings indicate that GTPBP4-PKM2 regulatory axis plays a vital role in promoting HCC proliferation as well as metastasis by aerobic glycolysis and offer a promising therapeutic target for HCC patients.

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GTPBP4 promotes HCC progression and metastasis in vitro and in vivo.

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Promoter hypomethylation upregulated GTPBP4 expression.

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GTPBP4 promotes the glycolysis in HCC via inducing dimeric PKM2 formation and sumoylation through UBA2-SUMO1 axis.

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GTPBP4 induces PKM2 nuclear transfer to act as a protein kinase to activate STAT3 and EMT signaling pathway.

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Shikonin induces significant anti-tumor effect in orthotopic mouse models harboring activation of GTPBP4/PKM2 axis.

RNF126 contributes to stem cell-like properties and metastasis in hepatocellular carcinoma through ubiquitination and degradation of LKB1

Hepatocellular carcinoma (HCC) is one of the malignant tumors with the worst prognosis, and tumor recurrence and metastasis are the main factors leading to poor prognosis of HCC patients. Accumulating studies show that RNF126, ring finger protein 126, is involved in the pathological process of many tumors. However, the biological function and exact molecular mechanism of RNF126 in HCC remain unclear. In this study, we investigated the role of RNF126 in the pathogenesis of HCC. By analyzing database and verifying with our clinical specimens, it was found that RNF126 was highly expressed in HCC tissues, which is associated with shorter overall survival and higher recurrence rate. Overexpressed RNF126 can significantly promote the proliferation, migration, invasion and angiogenesis of HCC cells, whereas knockdown RNF126 can reverse this effect. Mechanically, RNF126 down-regulates liver kinase B1 (LKB1) expression by ubiquitination of LKB1 to weaken its stability, thereby significantly promoting stem-cell-like activity, migration, and angiogenesis of HCC. Notably, consistent with in vitro results, RNF126 was stably transformed in Hep3B and subcutaneously injected into nude mice. In established mouse xenograft models, tumor growth can be effectively inhibited and the occurrence of lung metastasis is reduced. In HCC, RNF126 may down-regulate LKB1 through ubiquitination, thus becoming a powerful prognostic biomarker and a recognized tumor suppressor. Therefore, our study may provide a promising new therapeutic strategy for targeting RNF126 for HCC patients.

Identification of Candidate Genes Associated With Prognosis in Glioblastoma

Background

Glioblastoma (GBM) is the most common malignant primary brain tumor, which associated with extremely poor prognosis.

Methods

Data from datasets GSE16011, GSE7696, GSE50161, GSE90598 and The Cancer Genome Atlas (TCGA) were analyzed to identify differentially expressed genes (DEGs) between patients and controls. DEGs common to all five datasets were analyzed for functional enrichment and for association with overall survival using Cox regression. Candidate genes were further screened using least absolute shrinkage and selection operator (LASSO) and random forest algorithms, and the effects of candidate genes on prognosis were explored using a Gaussian mixed model, a risk model, and concordance cluster analysis. We also characterized the GBM landscape of immune cell infiltration, methylation, and somatic mutations.

Results

We identified 3,139 common DEGs, which were associated mainly with PI3K-Akt signaling, focal adhesion, and Hippo signaling. Cox regression identified 106 common DEGs that were significantly associated with overall survival. LASSO and random forest algorithms identified six candidate genes (AEBP1, ANXA2R, MAP1LC3A, TMEM60, PRRG3 and RPS4X) that predicted overall survival and GBM recurrence. AEBP1 showed the best prognostic performance. We found that GBM tissues were heavily infiltrated by T helper cells and macrophages, which correlated with higher AEBP1 expression. Stratifying patients based on the six candidate genes led to two groups with significantly different overall survival. Somatic mutations in AEBP1 and modified methylation of MAP1LC3A were associated with GBM.

Conclusion

We have identified candidate genes, particularly AEBP1, strongly associated with GBM prognosis, which may help in efforts to understand and treat the disease.

Targeting the lncRNA FGD5-AS1/miR-497-5p/PD-L1 Axis Inhibits Malignant Phenotypes in Colon Cancer (CC)

Long noncoding RNAs (lncRNAs) regulate cancer progression and drug resistance. However, the role of lncRNA FGD5-AS1 in regulating colon cancer (CC) progression is still largely unknown. Hence, this study investigated the role of lncRNA FGD5-AS1 in regulating colon cancer (CC) progression and found that lncRNA FGD5-AS1 regulated miR-497-5p/PD-L1 axis to promote cancer progression in CC cells in vitro and in vivo. Specifically, we found that lncRNA FGD5-AS1 and PD-L1 tended to be high-expressed, while miR-497-5p was low-expressed in CC tissues and cell lines compared to the normal adjacent tissues and cells. Next, we found that lncRNA FGD5-AS1 positively regulated PD-L1 in CC cells by sponging miR-497-5p. Finally, our gain- and loss-of-function experiments evidenced that the lncRNA FGD5-AS1/miR-497-5p/PD-L1 axis regulates CC progression. Functionally, the data suggested that lncRNA FGD5-AS1 positively regulated while miR-497-5p negatively modulated malignant phenotypes, including cell proliferation, viability, invasion, migration, epithelial-mesenchymal transition (EMT), and tumorigenesis in CC cells. Interestingly, the inhibiting effects of lncRNA FGD5-AS1 ablation on CC development were abrogated by both silencing miR-497-5p and upregulating PD-L1. This study found that lncRNA FGD5-AS1 sponged miR-497-5p to upregulate PD-L1, resulting in CC progression, and provided novel agents for CC diagnosis and prognosis.

Single-cell RNA sequencing to explore composition of peripheral blood NK cells in patients with chronic myeloid leukemia in treatment-free remission

This study was to explore the role of NK cell subsets and gene expression in maintaining TFR status. We identified six types of NK cells in the PBMCs over both groups (healthy controls and patients with TFR). Gene Oncology analysis showed that up regulated genes were enriched in the categories of "immune response," "reaction to tumor cells," and "cytolysis." In addition, we found that the three NK cell subsets, mature and terminal NK cells, CD56 bright NK cells, and transitional NK cells, contained many significantly up regulated genes in both groups, and that CD56 bright NK cells and transitional NK cells in patients with CML-TFR were in a proliferating and activated state. Through single-cell RNA sequencing analysis, we confirmed that the mature and terminal, CD56 bright, and transitional subsets of NK cells play an indispensable role in maintaining TFR in patients with CML.

Structural, molecular, and functional insights into Schlafen proteins

Schlafen (SLFN) genes belong to a vertebrate gene family encoding proteins with high sequence homology. However, each SLFN is functionally divergent and differentially expressed in various tissues and species, showing a wide range of expression in cancer and normal cells. SLFNs are involved in various cellular and tissue-specific processes, including DNA replication, proliferation, immune and interferon responses, viral infections, and sensitivity to DNA-targeted anticancer agents. The fundamental molecular characteristics of SLFNs and their structures are beginning to be elucidated. Here, we review recent structural insights into the N-terminal, middle and C-terminal domains (N-, M-, and C-domains, respectively) of human SLFNs and discuss the current understanding of their biological roles. We review the distinct molecular activities of SLFN11, SLFN5, and SLFN12 and the relevance of SLFN11 as a predictive biomarker in oncology.

The diverse roles that Schlafen family proteins play in cell proliferation, immune modulation, and other biological processes make them promising targets for treating and tracking diseases, especially cancer. Ukhyun Jo and Yves Pommier from the National Cancer Institute in Bethesda, USA, review the molecular characteristics and structural features of Schlafen proteins. These proteins take their name from the German word for “sleep”, as the first described Schlafen proteins caused cells to stop dividing, although later reports found that related members of the same protein family serve myriad cellular functions, including in the regulation of DNA replication. A better understanding of Schlafen proteins could open up new avenues in cancer management, for instance, diagnostics that monitor activity levels of one such protein, SLFN11, could help oncologists predict how well patients might respond to anti-cancer therapies.

Effect of TDP43-CTFs35 on Brain Endothelial Cell Functions in Cerebral Ischemic Injury

Pathological changes in the brain endothelium play an important role in the progression of ischemic stroke and the compromised BBB under ischemic stroke conditions cause neuronal damage. However, the pathophysiological mechanisms of the BBB under normal conditions and under ischemic stroke conditions have not been fully elucidated. The present study demonstrated that knockdown of TAR DNA-binding protein 43 (TDP-43) or overexpression of TDP43-CTFs35 inhibited tight junction protein expression, and mammalian sterile-20-like 1/2 (MST1/2) and YES-associated protein (YAP) phosphorylation in brain ECs and suppressed brain EC migration in vitro. The cytoplasmic TDP43-CTFs35 level was increased in brain ECs 24 h and 72 h after MCAO, but it disappeared 1 week after cerebral ischemia. The expression of tight junction proteins was also significantly deceased 24 h after MCAO and then gradually recovered at 72 h and 1 week after MCAO. The level of YAP phosphorylation was first significantly decreased 24 h after MCAO and then increased 72 h and 1 week after MCAO, accompanied by nuclear YAP translocation. The underlying mechanism is TDP43-CTFs35-mediated inhibition of Hippo signaling pathway activity through the dephosphorylation of MST1/2, which leads to the inhibition of YAP phosphorylation and the subsequent impairment of brain EC migration and tight junction protein expression. This study provides new insights into the mechanisms of brain vascular EC regulation, which may impact on BBB integrity after cerebral ischemic injury.

Can Schlafen 11 Help to Stratify Ovarian Cancer Patients Treated with DNA-Damaging Agents?

Platinum-based chemotherapy has been the cornerstone of systemic treatment in ovarian cancer. Since no validated molecular predictive markers have been identified yet, the response to platinum-based chemotherapy has been evaluated clinically, based on platinum-free interval. The new promising marker Schlafen 11 seems to correlate with sensitivity or resistance to DNA-damaging agents, including platinum compounds or PARP inhibitors in various types of cancer. We provide background information about the function of Schlafen 11, its evaluation in tumor tissue, and its prevalence in ovarian cancer. We discuss the current evidence of the correlation of Schlafen 11 expression in ovarian cancer with treatment outcomes and the potential use of Schlafen 11 as the key predictive and prognostic marker that could help to better stratify ovarian cancer patients treated with platinum-based chemotherapy or PARP inhibitors. We also provide perspectives on future directions in the research on this promising marker.

Circular RNA circ_0002360 regulates the Taxol resistance and malignant behaviors of Taxol-resistant non-small cell lung cancer cells by microRNA-585-3p-dependent modulation of G protein regulated inducer of neurite outgrowth 1

Drug resistance has become the major obstacle for the treatment of non-small cell lung cancer (NSCLC). Circular RNAs (circRNAs) are tightly linked to the development of drug resistance of NSCLC. Herein, we tested the function of circ_0002360 in the Taxol resistance of NSCLC. Circ_0002360, microRNA (miR)-585-3p and G protein regulated inducer of neurite outgrowth 1 (GPRIN1) were quantified by quantitative real-time PCR (qRT-PCR). To identify the circular structure of circ_0002360, RNase R digestion was applied. To detect cell proliferation, colony formation and 5-ethynyl-2’-deoxyuridine (EdU) assays were used. For assessment of cell apoptosis, flow cytometry was adopted. For motility and invasion analyses, transwell assay was employed. Our data showed that circ_0002360 was mainly located in the cytoplasm and was highly expressed in the Taxol-resistant NSCLC. Silencing of circ_0002360 inhibited cell Taxol resistance, proliferation, motility, and invasiveness and induced apoptosis in vitro. MiR-585-3p was underexpressed in Taxol-resistant NSCLC and was targeted by circ_0002360. MiR-585-3p knockdown alleviated the influence of circ_0002360 silence on Taxol-resistant cells. GPRIN1 was directly targeted by miR-585-3p. The influence of miR-585-3p on cell Taxol resistance and functional behaviors was reversed by GPRIN1 overexpression. Moreover, circ_0002360 modulated GPRIN1 through miR-585-3p. Additionally, silencing of circ_0002360 weakened the growth of xenografts in vivo. Our study demonstrated that silencing of circ_0002360 enhanced the Taxol sensitivity and suppressed the malignant behaviors of Taxol-resistant NSCLC cells by miR-585-3p/GPRIN1 axis, providing novel targets for improving the anti-tumor efficacy of Taxol in NSCLC.

Pre-mRNA processing factor 19 functions in DNA damage repair and radioresistance by modulating cyclin D1 in hepatocellular carcinoma

Pre-mRNA processing factor 19 (PRP19) is elevated in hepatocellular carcinoma (HCC); however, little is known about its function in DNA damage repair in HCC. In this study, analysis of The Cancer Genome Atlas data and our tumor models after ionizing radiation (IR) treatment indicated that increased expression of PRP19 was positively correlated with DNA damage repair. Gain of PRP19 expression induced by plasmids resulted in decreases in apoptosis and double-strand breaks (DSBs), and an increase in cell survival after IR. Loss of PRP19 expression induced by small interfering RNAs resulted in the accumulation of apoptosis and DSBs, and a decrease in cell survival. Mechanistically, the effect of PRP19 on DNA damage repair was mediated by the modulation of cyclin D1 expression in HCC. PRP19 controlled the translation of cyclin D1 by modulating eukaryotic initiation factor 4E. PRP19 affected the DNA damage repair ability of cyclin D1 by interacting with the WD40 domain. The combination of PRP19 and cyclin D1 was more valuable than each single marker for predicting the prognosis of patients. Taken together, the present results demonstrate that PRP19 promotes DNA damage repair by modulating cyclin D1 expression and function, thereby contributing to the radioresistance in HCC.

Deregulation of ribosomal proteins in human cancers

The ribosome, the site for protein synthesis, is composed of ribosomal RNAs (rRNAs) and ribosomal proteins (RPs). The latter have been shown to have many ribosomal and extraribosomal functions. RPs are implicated in a variety of pathological processes, especially tumorigenesis and cell transformation. In this review, we will focus on the recent advances that shed light on the effects of RPs deregulation in different types of cancer and their roles in regulating the tumor cell fate.

DEAD-box Helicase 27 Promotes Hepatocellular Carcinoma Progression Through ERK Signaling

Introduction: DEAD-box helicase 27 (DDX27) belongs to DEAD-Box nucleic acid helicase family. The function of DDX27 in hepatocellular carcinoma (HCC) remain enigmatic. In light of this, we tried to investigate the regulatory role and underlying mechanism of DDX27 in HCC. Materials and methods: DDX27 expression levels were detected by qRT-PCR, Western blot and immunohistochemistry assays in HCC tissues and cells. Colony formation, CCK-8, growth curve, wound healing and transwell assays were conducted to investigate the effect of DDX27 on the proliferation and metastasis of HCC cells. RNA-sequencing was performed to detect the effect of DDX27 on downstream signaling pathway. The effect of DDX27 on HCC progression was evaluated using in vivo murine xenograft model. Results: we found an increased expression of DDX27 in HCC tissues with comparison to its para-tumor tissues. The high expression levels of DDX27 were associated with poor prognosis in HCC patients. DDX27 upregulation promoted cell metastasis. Mechanistic studies suggested that DDX27 overexpression induces the major vault protein (MVP) expression and enhances the phosphorylation levels of ERK1/2. Inhibition of ERK pathway impaired the cellular metastastic abilities induced by DDX27. The induction of DDX27 in HCC progression was further confirmed from tumors in mouse model. Conclusion: our results disclose a novel mechanism by which DDX27 enhances ERK signaling during HCC progression. DDX27 might be used in targeted therapy for HCC patients.

Ubiquitin-associated protein 2 like (UBAP2L) enhances growth and metastasis of gastric cancer cells

Ubiquitin-proteasome pathway has emerged as therapeutic targets for cancer. GEPIA database analysis showed that the expression of ubiquitin-associated protein 2 like (UBAP2L) in gastric cancer specimens was significantly higher than that in non-tumor tissue, and its high expression is associated with poor survival of gastric cancer patients. This study aims to investigate the role of UBAP2L in gastric cancer. Real-time PCR and western blot results showed that UBAP2L expression was upregulated in gastric cancer cell lines. Loss- and gain-of-function experiments demonstrated that silencing of UBAP2L inhibited proliferation, migration and invasion, and induced apoptosis of gastric cancer cells, and overexpression of UBAP2L played opposite roles. Nude mice inoculated with UBAP2L-silenced gastric cancer cells generated smaller xenografted tumors in vivo. Furthermore, UBAP2L activated Wnt/β-catenin signaling - the accumulation of nuclear β-catenin and the expression of its downstream targets (cyclin D1, AXIN-2 and c-MYC) was facilitated, whereas knockdown of UBAP2L deactivated this signaling. The tumor-suppressing effect of UBAP2L silencing was abolished by forced activation of β-cateninS33A. UBAP2L has been confirmed as a novel and direct target of miR-148b-3p. The anti-tumor effect of miR-148b-3p was partly reversed by UBAP2L overexpression. The expression of miR-148b-3p was negatively correlated with that of UBAP2L in gastric cancer samples. Overall, our study indicates that UBAP2L is required to maintain malignant behavior of gastric cancer cells, which involves the activation of Wnt/β-catenin signaling pathway. We propose UBAP2L as a potential therapeutic target against gastric cancer.

LAGE3 promoted cell proliferation, migration, and invasion and inhibited cell apoptosis of hepatocellular carcinoma by facilitating the JNK and ERK signaling pathway

BACKGROUND

Hepatocellular carcinoma (HCC) is now the second leading cause of cancer death worldwide and lacks effectual therapy due to its high rate of tumor recurrence and metastasis. The aim of this study was to investigate the effects of L antigen family member 3 (LAGE3, a member of the LAGE gene family involved in positive transcription) on the progression of HCC.

METHODS

The expression of LAGE3 was detected by quantitative real-time polymerase chain reaction. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, colony formation assay, EdU, and cell cycle analysis assay were employed to evaluate the proliferation of HCC cells. Annexin V-FITC/PI and TUNEL assay were used to assess the apoptosis rate of HCC cells. Wound healing and transwell assay were used to investigate the migration and invasion of HCC cells. A xenograft model of HCC was established with 2 × 10⁶ Hep3B or SK-HEP1 cells to investigate the in vivo effects of LAGE3. Then, the protein levels of LAGE3, p-p38, p-38, c-Jun N-terminal kinase (JNK),p-JNK, extracellular signal-regulated kinase (ERK), and p-ERK were detected by western blot.

RESULTS

We found that LAGE3 was upregulated in HCC tissues compared to adjacent tissues, and its high expression was correlated with poor overall survival by bioinformatics analysis. Next, we manually regulated the expression of LAGE3 in HCC cells. The knockdown of LAGE3 inhibited the proliferation of HCC cells by arresting the cell cycle in G1 phase. Also the downregulation of LAGE3 inhibited cell migration and invasion and induced apoptosis of HCC cells, while overexpression of LAGE3 promoted the malignant phenotypes of HCC. These results were further confirmed by the in vivo growth of HCC xenografts and the inhibition of apoptosis of HCC tumor cells. Furthermore, we found that LAGE3 exerted cancer-promoting effects by potentiating the JNK and ERK signaling pathway. An ERK inhibitor (10 μM SCH772984) or JNK inhibitor (25 μM SP600125) repressed the upregulated LAGE3-induced proliferation, migration, and invasion of HCC cells.

CONCLUSIONS

LAGE3 enhanced the malignant phenotypes of HCC by promoting the JNK and ERK signaling pathway.

A wake-up call for cancer DNA damage: the role of Schlafen 11 (SLFN11) across multiple cancers

DNA-damaging agents exploit increased genomic instability, a hallmark of cancer. Recently, inhibitors targeting the DNA damage response (DDR) pathways, such as PARP inhibitors, have also shown promising therapeutic potential. However, not all tumors respond well to these treatments, suggesting additional determinants of response are required. Schlafen 11 (SLFN11), a putative DNA/RNA helicase that induces irreversible replication block, is emerging as an important regulator of cellular response to DNA damage. Preclinical and emerging clinical trial data suggest that SLFN11 is a predictive biomarker of response to a wide range of therapeutics that cause DNA damage including platinum salts and topoisomerase I/II inhibitors, as well as PARP inhibitors, which has raised exciting possibilities for its clinical application. In this article, we review the function, prevalence, and clinical testing of SLFN11 in tumor biopsy samples and circulating tumor cells. We discuss mounting evidence of SLFN11 as a key predictive biomarker for a wide range of cancer therapeutics and as a prognostic marker across several cancer types. Furthermore, we discuss emerging areas of investigation such as epigenetic reactivation of SLFN11 and its role in activating immune response. We then provide perspectives on open questions and future directions in studying this important biomarker.

Study of Clinical Predictive Value and Immune Characterization of SLFN11 in Clear Cell Renal Cell Carcinoma

Background

SLFN11 has been found to regulate the development and progression of a variety of cancers and is associated with drug therapy, while its role in clear cell renal cell carcinoma (ccRCC) remains unclear; therefore, the aim of this study was to investigate SLFN11 expression in ccRCC patients and its correlations with clinicopathological and immunological features.

Methods

Gene profiles of ccRCC and the clinicopathological information of patients were downloaded from the TCGA database. Microarrays from the GEO database were used as a validation set for SLFN11 expression, which was experimentally verified in renal cancer cell lines by quantitative polymerase chain reaction (qPCR); protein expression and methylation levels were obtained from the HPA database and the UALCAN database. ROC curves, Kaplan–Meier survival analysis and Cox analysis were used to assess the diagnostic and predictive value of SLFN11 in ccRCC. Protein–protein interaction (PPI) networks for SLFN11 were obtained from the STRING website, and the TISIDB and TIMER 2.0 databases were used to study the relationship between SLFN11 and immune infiltration in the tumour microenvironment (TME).

Results

SLFN11 was significantly overexpressed in ccRCC tissues and renal cancer cell lines, which may be closely related to its hypermethylation status (P < 0.001). SLFN11 was positively correlated with a highly aggressive disease state, with the ROC curve showing an AUC value of 0.910 for SLFN11 in diagnosing ccRCC, and Kaplan–Meier and Cox analyses also revealed that upregulation of SLFN11 predicted a poor prognosis for ccRCC patients (P < 0.05). In addition, enrichment analysis showed that SLFN11 was closely associated with immune-related signalling pathways, and further exploration comprehensively demonstrated strong positive correlations with tumour immune lymphocytes, immune checkpoint genes, chemokines and chemokine receptors.

Conclusion

Overall, our data analysis shows that SLFN11 is a strong diagnostic and prognostic biomarker for ccRCC and is also associated with immune infiltration in the TME.

Schlafen 11 expression in human acute leukemia cells with gain-of-function mutations in the interferon-JAK signaling pathway

Schlafen11 (SLFN11) is referred to as interferon (IFN)-inducible. Based on cancer genomic databases, we identified human acute myeloid and lymphoblastic leukemia cells with gain-of-function mutations in the Janus kinase (JAK) family as exhibiting high SLFN11 expression. In these cells, the clinical JAK inhibitors cerdulatinib, ruxolitinib, and tofacitinib reduced SLFN11 expression, but IFN did not further induce SLFN11 despite phosphorylated STAT1. We provide evidence that suppression of SLFN11 by JAK inhibitors is caused by inactivation of the non-canonical IFN pathway controlled by AKT and ERK. Accordingly, the AKT and ERK inhibitors MK-2206 and SCH77284 suppressed SLFN11 expression. Both also suppressed the E26 transformation-specific (ETS)-family genes ETS-1 and FLI-1 that act as transcription factors for SLFN11. Moreover, SLFN11 expression was inhibited by the ETS inhibitor TK216. Our study reveals that SLFN11 expression is regulated via the JAK, AKT and ERK, and ETS axis. Pharmacological suppression of SLFN11 warrants future studies.

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SLFN11 expression is high in leukemia and confers response to DNA targeted agents

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SLFN11 expression is driven by the innate immune IFN-JAK signaling pathway

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Leukemia cell lines with JAK-GOF-mutations express high SLFN11 downstream from the AKT/ERK-ETS pathway

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JAK and ETS inhibitors suppress SLFN11 expression

miR-328-3p promotes migration and invasion by targeting H2AFX in head and neck squamous cell carcinoma

Migration and invasion are the initial step in the metastatic process, while metastasis is responsible for the poor prognosis of head and neck squamous cell carcinoma (HNSCC). Since miRNA has been found as an important regulator of gene expression at the post-transcriptional level in various diseases including carcinoma, exploring the role of miRNA in cancer metastasis will facilitate the target therapy of advanced HNSCC. MiR-328-3p has been reported to be an onco-miRNA or a tumor suppressor in several cancers. However, the role of miR-328-3p in HNSCC migration and invasion remains undefined. In this study, we first demonstrated that miR-328-3p enhanced migration and invasion of HNSCC in vitro, accompanying with a promotion of epithelial-mesenchymal transition (EMT) and mTOR activity. Meanwhile, we confirmed that miR-328-3p directly targeted the 3'UTR of H2A histone family, member X (H2AFX), which served as a tumor suppressor in migration and invasion of HNSCC. Moreover, H2AFX could partially reverse the migration and invasion of HNSCC caused by miR-328-3p. Overall, our results indicated that miR-328-3p enhanced migration and invasion of HNSCC through targeting H2AFX and activated the mTOR pathway.

Upregulation of Nei-Like DNA Glycosylase 3 Predicts Poor Prognosis in Hepatocellular Carcinoma

Background

Accumulating evidence has suggested that Nei-like DNA glycosylase 3 (NEIL3) is associated with human tumors. However, there are few studies on the role of NEIL3 in hepatocellular carcinoma (HCC). The aim of this study was to investigate the expression profile of NEIL3 and its clinical relevance in HCC.

Materials and Methods

A total of 130 HCC and corresponding nontumor tissues were collected to perform immunohistochemistry (IHC). The clinical relevance and prognostic value of NEIL3 in HCC were analyzed by the chi-square test, Kaplan–Meier analysis, the Cox proportional hazard model, and nomogram.

Results

IHC showed that the NEIL3 protein level was remarkably upregulated in tumor tissues compared with nontumor tissues (fold change = 1.24; P < 0.001). High NEIL3 expression was significantly correlated with BCLC stage (P=0.004) and TNM stage (P=0.005). Overall survival (OS) and disease-free survival (DFS) rates in the high NEIL3 expression group were significantly worse than those in the low NEIL3 expression group (P=0.007 and P=0.004, respectively). Furthermore, subgroup analysis showed that high NEIL3 expression predicted worse OS and DFS for HCC patients with advanced TNM stage, poorly differentiated tumor, HBsAg positive, or cirrhosis. Multivariate analysis and the prognostic nomograms revealed that tumor NEIL3 level may serve as a promising prognostic indicator for OS and DFS in HCC patients.

Conclusion

Our findings suggested that NEIL3 might be a potential prognosis assessment marker and therapeutic target for HCC patients.

Schlafens: Emerging Proteins in Cancer Cell Biology

Schlafens (SLFN) are a family of genes widely expressed in mammals, including humans and rodents. These intriguing proteins play different roles in regulating cell proliferation, cell differentiation, immune cell growth and maturation, and inhibiting viral replication. The emerging evidence is implicating Schlafens in cancer biology and chemosensitivity. Although Schlafens share common domains and a high degree of homology, different Schlafens act differently. In particular, they show specific and occasionally opposing effects in some cancer types. This review will briefly summarize the history, structure, and non-malignant biological functions of Schlafens. The roles of human and mouse Schlafens in different cancer types will then be outlined. Finally, we will discuss the implication of Schlafens in the anti-tumor effect of interferons and the use of Schlafens as predictors of chemosensitivity.

LPCAT1 overexpression promotes the progression of hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) remains one of the most common malignant neoplasms. Lysophosphatidylcholine acyltransferase 1 (LPCAT1) plays a key role in the lipid remodelling and is correlated with various neoplasms. Nonetheless, the biological functions and molecular mechanisms of LPCAT1 underlying HCC remain obscure.

METHODS

In the present study, we investigated the role of LPCAT1 in the progression of HCC. In-house RT-qPCR, tissue microarrays, and immunohistochemistry were performed to detect the expression levels and the clinical value of LPCAT1 in HCC. External datasets were downloaded to confirm the results. Proliferation, migration, invasiveness, cell cycle, and apoptosis assays were conducted to reveal the biological effects LPCAT1 has on SMMC-7721 and Huh7 cells. HCC differentially expressed genes and LPCAT1 co-expressed genes were identified to explore the molecular mechanisms underlying HCC progression.

RESULTS

LPCAT1 showed upregulated expression in 3715 HCC specimens as opposed to 3105 non-tumour specimens. Additionally, LPCAT1 might be an independent prognostic factor for HCC. LPCAT1-knockout hampered cellular proliferation, migration, and metastasis in SMMC-7721 and Huh7 cells. More importantly, the cell cycle and chemical carcinogenesis were the two most enriched signalling pathways.

CONCLUSIONS

The present study demonstrated that increased LPCAT1 correlated with poor prognosis in HCC patients and fuelled HCC progression by promoting cellular growth, migration, and metastasis.

Tumor cell-imposed iron restriction drives immunosuppressive polarization of tumor-associated macrophages

Background

Tumor-associated macrophages (TAM) are immunosuppressive cells that contribute to impaired anti-cancer immunity. Iron plays a critical role in regulating macrophage function. However, it is still elusive whether it can drive the functional polarization of macrophages in the context of cancer and how tumor cells affect the iron-handing properties of TAM. In this study, using hepatocellular carcinoma (HCC) as a study model, we aimed to explore the effect and mechanism of reduced ferrous iron in TAM.

Methods

TAM from HCC patients and mouse HCC tissues were collected to analyze the level of ferrous iron. Quantitative real-time PCR was used to assess M1 or M2 signature genes of macrophages treated with iron chelators. A co-culture system was established to explore the iron competition between macrophages and HCC cells. Flow cytometry analysis was performed to determine the holo-transferrin uptake of macrophages. HCC samples from The Cancer Genome Atlas (TCGA) were enrolled to evaluate the prognostic value of transferrin receptor (TFRC) and its relevance to tumor-infiltrating M2 macrophages.

Results

We revealed that ferrous iron in M2-like TAM is lower than that in M1-like TAM. In vitro analysis showed that loss of iron-induced immunosuppressive M2 polarization of mouse macrophages. Further experiments showed that TFRC, the primary receptor for transferrin-mediated iron uptake, was overexpressed on HCC cells but not TAM. Mechanistically, HCC cells competed with macrophages for iron to upregulate the expression of M2-related genes via induction of HIF-1α, thus contributing to M2-like TAM polarization. We further clarified the oncogenic role of TFRC in HCC patients by TCGA. TFRC is significantly increased in varieties of malignancies, including HCC, and HCC patients with high TFRC levels have considerably shortened overall survival. Also, TFRC is shown to be positively related to tumor-infiltrating M2 macrophages.

Conclusions

Collectively, we identified iron starvation through TFRC-mediated iron competition drives functional immunosuppressive polarization of TAM, providing new insight into the interconnection between iron metabolism and tumor immunity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03034-7.

RPL19 Is a Prognostic Biomarker and Promotes Tumor Progression in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most common malignancies, and the therapeutic outcome remains undesirable due to its recurrence and metastasis. Gene dysregulation plays a pivotal role in the occurrence and progression of cancer, and the molecular mechanisms are largely unknown.

Methods

The differentially expressed genes of HCC screened from the GSE39791 dataset were used to conduct weighted gene co-expression network analysis. The selected hub genes were validated in The Cancer Genome Atlas (TCGA) database and 11 HCC datasets from the Gene Expression Omnibus (GEO) database. Then, a tissue microarray comprising 90 HCC specimens and 90 adjacent normal specimens was used to validate the hub genes. Moreover, the Hallmark, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases were used to identify enriched pathways. Then, we conducted the immune infiltration analysis.

Results

A total of 17 co-expression modules were obtained by weighted gene co-expression network analysis. The green, blue, and purple modules were the most relevant to HCC samples. Four hub genes, RPL19, RPL35A, RPL27A, and RPS12, were identified. Interestingly, we found that all four genes were highly expressed in HCC and that their high expression was related to a poor prognosis by analyzing the TCGA and GEO databases. Furthermore, we investigated RPL19 in HCC tissue microarrays and demonstrated that RPL19 was overexpressed in tumor tissues compared with non-tumor tissues (p = 0.016). Moreover, overexpression of RPL19 predicted a poor prognosis in hepatocellular carcinoma (p < 0.0007). Then, enrichment analysis revealed that cell cycle pathways were significantly enriched, and bile acid metabolism-related pathways were significantly down-regulated when RPL19 was highly expressed. Furthermore, immune infiltration analysis showed that immune response was suppressed.

Conclusion

Our study demonstrates that RPL19 may play an important role in promoting tumor progression and is correlated with a poor prognosis in HCC. RPL19 may serve as a promising biomarker and therapeutic target for the precise diagnosis and treatment of HCC in the future.

NEAT1 Overexpression Indicates a Poor Prognosis and Induces Chemotherapy Resistance via the miR-491-5p/SOX3 Signaling Pathway in Ovarian Cancer

Background

Accumulated studies have reported that dysregulated long non-coding RNAs (lncRNAs) are crucial in ovarian cancer (OC) initiation and development. However, detailed biological functions of lncRNA NEAT1 during the progression of OC remains to be uncovered.

Purpose

Our aim was to identify the role of NEAT1 in cisplatin resistance of ovarian cancer and the underlying mechanisms.

Methods

The expression patterns of NEAT1 in OC cell lines and tissue samples were identified by qRT-PCR. The cisplatin (DDP) sensitivity of OC cells was detected by MTT and CCK8 assay, while OC cell apoptosis and cell cycle were detected using flow cytometer assays. In addition, effects of NEAT1 on tumor growth were determined by xenograft tumor model. Luciferase reporter assay was conducted to prove the regulatory relation of miR-491-5p, NEAT1, and SOX3. Importantly, the expression of NEAT1 in exosomes from cisplatin-resistant patients was also determined by using qRT-PCR.

Results

In this study, upregulated NEAT1 was detected in OC cell lines and tissues. Meanwhile, NEAT1 was also increased in cisplatin-resistant OC cell lines and tissues. Upregulation of NEAT1 inhibited cisplatin-induced OC cell apoptosis and promoted cell proliferation, while knockdown of NEAT1 played the opposite role. These effects were also observed in vivo. Furthermore, direct interaction was observed between NEAT1 and miR-491-5p. NEAT1 led to the upregulation of miR-491-5p-targeted SOX3 mRNA. Importantly, this study also showed upregulated NEAT1 expression in serum exosomes derived from cisplatin-resistant patients.

Conclusion

NEAT1 is vital in the chemoresistance of ovarian cancer through regulating miR-491-5p/SOX3 pathway, showing that NEAT1 might be a potential target for OC resistance treatment.

SLFN11 Inactivation Induces Proteotoxic Stress and Sensitizes Cancer Cells to Ubiquitin Activating Enzyme Inhibitor TAK-243

Schlafen11 (SLFN11) inactivation occurs in approximately 50% of cancer cell lines and in a large fraction of patient tumor samples, which leads to chemoresistance. Therefore, new therapeutic approaches are needed to target SLFN11-deficient cancers. To that effect, we conducted a drug screen with the NCATS mechanistic drug library of 1,978 compounds in isogenic SLFN11-knockout (KO) and wild-type (WT) leukemia cell lines. Here we report that TAK-243, a first-in-class ubiquitin activating enzyme UBA1 inhibitor in clinical development, causes preferential cytotoxicity in SLFN11-KO cells; this effect is associated with claspin-mediated DNA replication inhibition by CHK1 independently of ATR. Additional analyses showed that SLFN11-KO cells exhibit consistently enhanced global protein ubiquitylation, endoplasmic reticulum (ER) stress, unfolded protein response (UPR), and protein aggregation. TAK-243 suppressed global protein ubiquitylation and activated the UPR transducers PERK, phosphorylated eIF2α, phosphorylated IRE1, and ATF6 more effectively in SLFN11-KO cells than in WT cells. Proteomic analysis using biotinylated mass spectrometry and RNAi screening also showed physical and functional interactions of SLFN11 with translation initiation complexes and protein folding machinery. These findings uncover a previously unknown function of SLFN11 as a regulator of protein quality control and attenuator of ER stress and UPR. Moreover, they suggest the potential value of TAK-243 in SLFN11-deficient tumors. SIGNIFICANCE: This study uncovers that SLFN11 deficiency induces proteotoxic stress and sensitizes cancer cells to TAK-243, suggesting that profiling SLFN11 status can serve as a therapeutic biomarker for cancer therapy.

TM2D1 contributes the epithelial-mesenchymal transition of hepatocellular carcinoma via modulating AKT/β-catenin axis

Various epidemiology studies showed the correlation between Alzheimer's disease (AD) and low incidence of cancer. However, the etiology underlying etiology of AD-related carcinogenesis remains largely elusive. Our study focused on characterizing the role of TM2D1 (TM2 domain containing 1) in hepatocellular carcinoma. TM2D1 is also known as β-amyloid peptide binding protein and is critical to the pathogenesis of AD. We found that TM2D1 is increasingly expressed in HCC tumors relative to the peritumoral tissues of the matched tumors and high TM2D1 expression predicts unfavorable clinical outcomes. TM2D1 overexpression induced HCC cell proliferation, migration and invasion, which was related to the epithelial-mesenchymal transition (EMT) observed in these cells. Conversely, TM2D1 depletion led to opposite phenotype in HCC. Mechanistically, we found that TM2D1 promoted Akt and β-catenin hyper-activation, which corresponded with molecular marker change in EMT signaling pathway. Taken together, our results indicated that TM2D1 played an important role in the EMT process in HCC cells by activating AKT and β-catenin signaling and may become a promising therapeutic target in HCC.

Knockdown of GTF2E2 inhibits the growth and progression of lung adenocarcinoma via RPS4X in vitro and in vivo

Background

Lung adenocarcinoma (LUAD) is one of the most common malignancies worldwide. However, the molecular mechanism of LUAD tumorigenesis and development remains unclear. The purpose of this study was to comprehensively illustrate the role of GTF2E2 in the growth and progression of LUAD.

Methods and materials

We obtained the mRNA expression data from The Cancer Genome Atlas, Gene Expression Omnibus database, and our institution. Systematic bioinformatical analyses were performed to investigate the expression and prognostic value of GTF2E2 in LUAD. The results were validated by immunohistochemistry and qPCR. The effect of knocking down GTF2E2 using two short hairpin RNAs was investigated by in vitro and in vivo assays. Subsequently, shotgun liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) analyses were applied to identified potential GTF2E2 interacting proteins, and the downstream molecular mechanisms of GTF2E2-signaling were further explored by a series of cellular functional assays.

Results

We found that GTF2E2 expression was significantly increased in LUAD tissue compared with adjacent normal tissue and was negatively associated with patients’ overall survival. Besides, we demonstrated that GTF2E2 knockdown inhibited LUAD cell proliferation, migration, invasion, and promote apoptosis in vitro, as well as attenuated tumor growth in vivo. Results from LC–MS/MS suggested that RPS4X might physically interact with GTF2E2 and mediated GTF2E2’s regulatory effect on LUAD development through the mTOR pathway.

Conclusion

Our findings indicate that GTF2E2 promotes LUAD development by activating RPS4X. Therefore, GTF2E2 might serve as a promising biomarker for the diagnosis and prognosis of LUAD patients, thus shedding light on the precise and personalized therapy for LUAD in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-01878-z.

REC8 promotes tumor migration, invasion and angiogenesis by targeting the PKA pathway in hepatocellular carcinoma

REC8 is a member of the cohesin family, and its abnormal activation has been detected in cancer cells. This study explored the role and possible mechanism of REC8 in hepatocellular carcinoma (HCC). A total of 40 pairs of HCC and adjacent tissues were collected, and the clinical significance of REC8 expression in HCC was evaluated. REC8 expression in human HCC tissues and HCC cell lines was investigated by quantitative real-time PCR, Western blotting, immunohistochemistry and immunofluorescence staining. The biological functions of REC8 in HCC cell lines were detected by wound-healing assay, Matrigel invasion assay and tube formation assay. The proteins interacting with REC8 were identified by mass spectrometry after immunoprecipitation screening. There was a correlation between the high expression of REC8 and positive alpha-fetoprotein levels. The expression level of REC8 protein in HCC tissues was higher than that in adjacent tissues. REC8 has mainly located in the nucleus of HCC tissue cells and HCC cell lines, but it was expressed in the cytoplasm of adjacent normal tissue cells and hepatocytes. The results of wound healing, transwell invasion and tubular formation assays indicated that the overexpression of REC8 accelerated the metastasis of HCC in vitro; however, metastasis was suppressed after REC8 was silenced by small interference RNA. A total of 57 differentially expressed proteins were identified by mass spectrometry, and it was found that REC8 and PKA RII-α staining was colocalized in the nucleus. The expression levels of MMP-9 and VEGF-C were decreased after treatment with the PKA inhibitor H89. Overall, REC8 promotes the migration, invasion and angiogenesis of HCC cells through the PKA pathway.