Serine threonine tyrosine kinase 1 is a potential prognostic marker in colorectal cancer

Overexpression of TSPAN8 in consensus molecular subtype 3 colorectal cancer

BACKGROUND

Recently, consensus molecular subtypes (CMSs) have been proposed as a robust transcriptome-based classification system for colorectal cancer (CRC). Tetraspanins (TSPANs) are transmembrane proteins. They have been associated with the development of numerous malignancies, including CRC, through their role as "master organizers" for multi-molecular membrane complexes. No previous study has investigated the correlation between TSPANs and CMS classification. Herein, we investigated the expression of TSPANs in patient-derived primary CRC tissues and their CMS classifications.

METHODS

RNA samples were derived from primary CRC tissues (n = 100 patients diagnosed with colorectal adenocarcinoma) and subjected to RNA sequencing for transcriptome-based CMS classification and TSPAN-relevant analyses. Immunohistochemistry (IHC) and immunofluorescence (IF) stains were conducted to observe the protein expression level. To evaluate the relative biological pathways, gene-set enrichment analysis was performed.

RESULTS

Of the highly expressed TSPAN genes in CRC tissues (TSPAN8, TSPAN29, and TSPAN30), TSPAN8 was notably overexpressed in CMS3-classified primary tissues. The overexpression of TSPAN8 protein in CMS3 CRC was also observed by IHC and IF staining. As a result of gene-set enrichment analysis, TSPAN8 may potentially play a role in organizing signaling complexes for kinase-based metabolic deregulation in CMS3 CRC.

CONCLUSIONS

The present study reports the overexpression of TSPAN8 in CMS3 CRC. This study proposes TSPAN8 as a subtype-specific biomarker for CMS3 CRC. This finding provides a foundation for future CMS-based studies of CRC, a complex disease and the second leading cause of cancer mortality worldwide.

STYK1/NOK affects cell cycle late mitosis and directly interacts with anaphase-promoting complex activator CDH1

The novel oncogene STYK1/NOK plays critical roles in cancer development. However, its regulation during cell division is less defined. In this paper, we show that over-expression of STYK1/NOK caused mitotic arrest and cytokinesis defects. The protein level of STYK/NOK fluctuated during the cell cycle, with a peak at mitosis and a quick reduction upon mitotic exit. The cell cycle-related expression pattern of STYK1/NOK resembled the one of aurora kinases and polo-like kinase 1. Depletion of APC3 led to accumulation of STYK1/NOK and to the G2/M arrest. Co-immunoprecipitation experiment demonstrated the direct interaction of STYK1/NOK with CDH1. Overexpression of CDH1 shortened the half-life of STYK1/NOK. The kinase domain, but not the five D boxes, of STYK1/NOK was responsible for the interaction with CDH1. Altogether, our data demonstrated for the first time that STYK1/NOK could affect cell division, probably by directly targeting key components of APC/C such as CDH1 at late mitosis. Current study may provide a vital mechanistic clue for understanding the roles of STYK1/NOK in mitosis and cytokinesis during STYK1NOK mediated genomic instability and oncogenesis.

The EGFR-STYK1-FGF1 axis sustains functional drug tolerance to EGFR inhibitors in EGFR-mutant non-small cell lung cancer

Non-small cell lung cancer (NSCLC) patients harboring activating mutations in epidermal growth factor receptor (EGFR) are sensitive to therapy with EGFR tyrosine kinase inhibitors (TKI). Despite remarkable clinical responses using EGFR TKI, surviving drug tolerant cells serve as a reservoir from which drug resistant tumors may emerge. This study addresses the need for improved efficacy of EGFR TKI by identifying targets involved in functional drug tolerance against them. To this aim, a high-throughput siRNA kinome screen was performed using two EGFR TKI-sensitive EGFR-mutant NSCLC cell lines in the presence/absence of the second-generation EGFR TKI afatinib. From the screen, Serine/Threonine/Tyrosine Kinase 1 (STYK1) was identified as a target that when downregulated potentiates the effects of EGFR inhibition in vitro. We found that chemical inhibition of EGFR combined with the siRNA-mediated knockdown of STYK1 led to a significant decrease in cancer cell viability and anchorage-independent cell growth. Further, we show that STYK1 selectively interacts with mutant EGFR and that the interaction is disrupted upon EGFR inhibition. Finally, we identified fibroblast growth factor 1 (FGF1) as a downstream effector of STYK1 in NSCLC cells. Accordingly, downregulation of STYK1 counteracted the afatinib-induced upregulation of FGF1. Altogether, we unveil STYK1 as a valuable target to repress the pool of surviving drug tolerant cells arising upon EGFR inhibition. Co-targeting of EGFR and STYK1 could lead to a better overall outcome for NSCLC patients.

STYK1/NOK Promotes Metastasis and Epithelial-Mesenchymal Transition in Non-small Cell Lung Cancer by Suppressing FoxO1 Signaling

Aims

Serine/threonine/tyrosine kinase 1 (STYK1) has been previously shown to have oncogenic properties, and emerging evidence suggests that STYK1 expression correlates with epithelial-mesenchymal transition (EMT). However, the mechanism of STYK1 involvement in oncogenesis remains unknown. The present study aimed to elucidate how STYK1 expression level relates to the metastasis, migration, invasion, and EMT in non-small cell lung cancer (NSCLC) and to determine the molecular mechanism of STYK1 effects.

Methods

Serine/threonine/tyrosine kinase 1 (STYK1) expression level and its relationship with the prognosis of NSCLC were determined using the ONCOMINE database and clinical cases. Non-small cell lung cancer cell lines with the overexpression or knockdown of STYK1 were established to determine whether STYK1 promotes cell migration, invasion, and EMT in vitro and in vivo. In addition, a constitutively active FoxO1 mutant (FoxO1AAA) was used to examine the role of FoxO1 in the STYK1-mediated upregulation of metastasis and EMT in NSCLC.

Results

Serine/threonine/tyrosine kinase 1 (STYK1) was upregulated in NSCLC tissues and cell lines, and its overexpression correlated with poor prognosis in patients with NSCLC after surgery. Enhanced expression of STYK1 potentiated the migration, invasion, and EMT in SW900 cells, thereby promoting metastasis, whereas knockdown of STYK1 inhibited these cellular phenomena in Calu-1 cells. Furthermore, STYK1 expression was positively related to the level of phosphorylated-FoxO1, whereas the constitutively active FoxO1 mutant protected against the positive effect of STYK1 overexpression on cell migration, invasion, and EMT.

Conclusion

Serine/threonine/tyrosine kinase 1 (STYK1) was upregulated in NSCLC and correlated with poor clinical outcomes. In addition, STYK1 suppressed FoxO1 functions, thereby promoting metastasis and EMT in NSCLC.

Development and analysis of long non-coding RNA-associated competing endogenous RNA network for osteosarcoma metastasis

Background

Osteosarcoma is the primary bone malignant neoplasm that often develops metastasis. Increasing evidences have shown that non-coding RNAs (ncRNAs) relate to the progression of osteosarcoma. However, the ncRNAs’ roles in osteosarcoma metastasis are still unknown.

Methods

Differentially expressed (DE) RNAs were identified from Gene Expression Omnibus (GEO) database. Protein-protein interaction (PPI) of DE messenger RNAs (DEmRNAs) was built through STRING database. The target mRNAs and long ncRNAs (lncRNAs) of microRNAs (miRNA) were predicted through miRDB, Targetscan and Genecode databases, which then cross-checked with previously obtained DERNAs to construct competing endogenous RNA (ceRNA) network. All networks were visualized via Cytoscape and the hub RNAs were screened out through Cytoscape plug-in Cytohubba. The gene functional and pathway analyses were performed through DAVID and MirPath databases. The survival analyses of hub RNAs were obtained through Kaplan-Meier (KM) survival curves.

Results

Five hundred sixty-four DEmRNAs, 16 DElncRNAs and 22 DEmiRNAs were screened out. GO functional and KEGG pathway analyses showed that DERNAs were significantly associated with tumor metastasis. The ceRNA network including 6 lncRNAs, 55 mRNAs and 20 miRNAs were constructed and the top 10 hub RNAs were obtained. Above all, PI3K/AKT signaling pathway was identified as the most important osteosarcoma metastasis-associated pathway and its hub ceRNA module was constructed. The survival analyses showed that the RNAs in hub ceRNA module closely related to osteosarcoma patients’ prognosis.

Conclusions

The current study provided a new perspective on osteosarcoma metastasis. More importantly, the RNAs in hub ceRNA module might act as the novel therapeutic targets and prognostic factors for osteosarcoma patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41065-021-00174-0.

Aberrantly High Expression Of NOK/STYK1 Is Tightly Associated With The Activation Of The AKT/GSK3β/N-Cadherin Pathway In Non-Small Cell Lung Cancer

Purpose

High metastasis is a leading risk factor for the survival of non-small cell lung cancer (NSCLC) and epithelial-mesenchymal transition (EMT) is a vital step of metastasis. The expression of novel oncogene with kinase domain (NOK) has been observed in some human malignancies, including non-small cell lung cancer (NSCLC); however, the biological function of NOK in NSCLC remains unclear. In the study, we explored the function of NOK in NSCLC, with an aim to elucidate the relevant underlying mechanisms.

Patients and methods

We investigate the expression of NOK, p-Akt, p-GSK-3β, E-cadherin and N-cadherin expression by immunohistochemical analysis using tissue microarrays of 72 paired NSCLC samples of cancerous and adjacent normal tissues. The associations between NOK expression and clinicopathological factors, overall survival, other proteins were assessed. Immunofluorescence analysis of NSCLC tissues was performed to study the location of NOK, Akt and GSK-3β. Up or down-regulated of NOK were conducted in two NSCLC cell lines to analyze its impact on AKT/GSK3β pathway.

Results

Statistical analysis revealed NOK expression increased in NSCLC tissues compared with normal tissues (P<0.05). It also showed that low NOK expression were associated with a higher possibility of non-lymphatic metastasis, an early pN stage and clinical stage (P<0.05). Moreover, NOK expression was positively correlated with the expression of oncogene p-Akt (Thr308), p-GSK-3β (Ser9) and N-cadherin (P<0.05). Immunofluorescence analysis of NSCLC tissues revealed that NOK is co-located with Akt and GSK-3β. Further study in NSCLC cell lines revealed that NOK overexpression can activate the AKT/GSK3β pathway. Conversely, knockdown of NOK can suppress the AKT/GSK3β pathway.

Conclusion

Our results suggest that NOK overexpression correlated significantly with lymphatic metastasis, advanced pN and clinical stage in NSCLC. And NOK may promote EMT by activating the AKT/GSK3β/N-cadherin pathway in NSCLC.

STYK1 promotes tumor growth and metastasis by reducing SPINT2/HAI-2 expression in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the leading cause of cancer deaths worldwide. However, the molecular mechanisms underlying NSCLC progression remains not fully understood. In this study, 347 patients with complete clinicopathologic characteristics who underwent NSCLC surgery were recruited for the investigation. We verified that elevated serine threonine tyrosine kinase 1 (STYK1) or decreased serine peptidase inhibitor Kunitz type 2 (SPINT2/HAI-2) expression significantly correlated with poor prognosis, tumor invasion, and metastasis of NSCLC patients. STYK1 overexpression promoted NSCLC cells proliferation, migration, and invasion. STYK1 also induced epithelial–mesenchymal transition by E-cadherin downregulation and Snail upregulation. Moreover, RNA-seq, quantitative polymerase chain reaction (qRT-PCR), and western blot analyses confirmed that STYK1 overexpression significantly decreased the SPINT2 level in NSCLC cells, and SPINT2 overexpression obviously reversed STYK1-mediated NSCLC progression both in vitro and in vivo. Further survival analyses showed that NSCLC patients with high STYK1 level and low SPINT2 level had the worst prognosis and survival. These results indicated that STYK1 facilitated NSCLC progression via reducing SPINT2 expression. Therefore, targeting STYK1 and SPINT2 may be a novel therapeutic strategy for NSCLC.

Targeting Protein Kinases to Enhance the Response to anti-PD-1/PD-L1 Immunotherapy

The interaction between programmed cell death protein (PD-1) and its ligand (PD-L1) is one of the main pathways used by some tumors to escape the immune response. In recent years, immunotherapies based on the use of antibodies against PD-1/PD-L1 have been postulated as a great promise for cancer treatment, increasing total survival compared to standard therapy in different tumors. Despite the hopefulness of these results, a significant percentage of patients do not respond to such therapy or will end up evolving toward a progressive disease. Besides their role in PD-L1 expression, altered protein kinases in tumor cells can limit the effectiveness of PD-1/PD-L1 blocking therapies at different levels. In this review, we describe the role of kinases that appear most frequently altered in tumor cells and that can be an impediment for the success of immunotherapies as well as the potential utility of protein kinase inhibitors to enhance the response to such treatments.

Decreased expression levels of DAL-1 and TOB1 are associated with clinicopathological features and poor prognosis in gastric cancer

PURPOSE

We previously demonstrated that the functional inactivation of DAL-1 and TOB1 promotes an aggressive phenotype in gastric cancer cells, but the links between both genes and the survival of patients with gastric cancer are unknown. Here, we investigated the correlations of the expression levels of DAL-1 and TOB1 with the progression of gastric cancer.

METHODS

A total of 270 patients who underwent resectable gastrectomy were included. The expression of DAL-1 and TOB1 was detected by immunohistochemistry.

RESULTS

Low expression of DAL-1 in cancer tissue was significantly associated with tumor site (p < 0.05), histological grade (p < 0.01), depth of invasion (p < 0.05), lymph node metastasis status (p < 0.05), Lauren classification (p < 0.001), and clinical stage (p < 0.01). A lower level of TOB1 was observed in gastric cancer patients with diffuse type disease compared to patients with either intestinal or mixed type disease (p < 0.001). Additionally, Spearman's correlation analysis revealed that decreased expression of DAL-1 was positively correlated with low TOB1 expression (r=0.304, p < 0.001). The survival analysis showed that low levels of DAL-1 and TOB1 were significantly associated with poor survival of gastric cancer patients (p <0.001 and p < 0.05, respectively).

CONCLUSION

The downregulation of DAL-1 and TOB1 expression is associated with shorter survival of gastric cancer patients. Hence, DAL-1 and TOB1 may be considered potential novel markers for predicting the outcomes of patients with gastric cancer.

Targeting Receptor Kinases in Colorectal Cancer

Colorectal cancer is the third most common malignancy in men and the second most common cancer in women. Despite the success of screening programs and the development of adjuvant therapies, the global burden of colorectal cancer is expected to increase by 60% to more than 2.2 million new cases and 1.1 million deaths by 2030. In recent years, a great effort has been made to demonstrate the utility of protein kinase inhibitors for cancer treatment. Considering this heterogeneous disease is defined by mutations that activate different Receptor Tyrosine Kinases (RTKs) and affect downstream components of RTK-activated transduction pathways, in this review we analyze the potential utility of different kinase inhibitors for colorectal cancer treatment.

Low STYK1 expression indicates poor prognosis in gastric cancer

Background

The expression of serine threonine tyrosine kinase 1 (STYK1), a member of the receptor protein tyrosine kinase (RPTK) family, is abnormal in several cancers. However, the molecular mechanism of STYK1 regulation of gastric cancer (GC) progression is unknown.

Materials and methods

We evaluated STYK1 expression in GC tissues and the corresponding normal tissues. Specimens from 93 patients with GC were examined with immunohistochemical staining. The relationship between STYK1 protein expression and the patients' clinicopathological features was assessed. Kaplan-Meier and Cox proportional regression analyses were used to evaluate the association between STYK1 expression and survival.

Results

STYK1 expression was decreased in GC tissues. Low STYK1 expression was significantly associated with poor tumor differentiation (P=0.023), advanced clinical stage (P=0.021), and poor overall survival (OS; P=0.034). Univariate and multivariate analyses revealed that STYK1expression was an independent prognostic indicator (HR =0.53, 95% CI =0.29-0.95, P=0.039; HR =0.51, 95% CI =0.24-0.91, P=0.030, respectively).

Conclusion

Downregulated STYK1 expression correlated significantly with poor tumor differentiation, advanced clinical stage, and poor OS in GC. STYK1 might be a diagnostic and prognostic indicator in patients with GC.

Profiles of immune infiltration in colorectal cancer and their clinical significant: A gene expression-based study

Immune infiltration of colorectal cancer (CRC) is closely associated with clinical outcome. However, previous work has not accounted for the diversity of functionally distinct cell types that make up the immune response. In this study, based on a deconvolution algorithm (known as CIBERSORT) and clinical annotated expression profiles, we comprehensively analyzed the tumor‐infiltrating immune cells present in CRC for the first time. The fraction of 22 immune cells subpopulations was evaluated to determine the associations between each cell type and survival and response to chemotherapy. As a result, profiles of immune infiltration vary significantly between paired cancer and paracancerous tissue and the variation could characterize the individual differences. Of the cell subpopulations investigated, tumors lacking M1 macrophages or with an increased number of M2 macrophages, eosinophils, and neutrophils were associated with the poor prognosis. Unsupervised clustering analysis using immune cell proportions revealed five subgroups of tumors, largely defined by the balance between macrophages M1, M2, and NK resting cells, with distinct survival patterns, and associated with well‐established molecular subtype. Collectively, our data suggest that subtle differences in the cellular composition of the immune infiltrate in CRC appear to exist, and these differences are likely to be important determinants of both prognosis and response to treatment.

Aberrant expression of STYK1 and E-cadherin confer a poor prognosis for pancreatic cancer patients

Previous studies showed that aberrant Serine/threonine/tyrosine kinase 1 (STYK1, also known as NOK) or/and E-cadherin were involved in the progression of some types of human cancers. However, whether they contributed to the development of pancreatic cancer was unknown. Here, we investigated the prognostic significance of aberrant STYK1 and E-cadherin in pancreatic cancer. Our results showed that STYK1 expression increased while E-cadherin decreased in pancreatic cancer tissues compared with normal pancreas tissues. STYK1 level was positively correlated with lymph node metastasis and clinical stage in pancreatic cancer patients. E-cadherin expression was inversely correlated with STYK1 expression in pancreatic cancer tissue samples. Patients with high STYK1 and low E-cadherin expression had the worst prognosis. In addition, STYK1 knockdown in pancreatic cancer cell lines inhibited cell proliferation, enhanced cell apoptosis, induced cell cycle arrest, and prohibited cell migration, while STYK1 over-expression showed the opposite effects. Silencing STYK1 also increased E-cadherin expression and inhibited epithelial-to-mesenchymal transition (EMT) and p-p38 expression in vitro. Over-expression had showed the opposite trends, and treatment with p38 inhibitor, SB203580, could reverse the trends. Thus, STYK1 repressed E-cadherin expression and promoted EMT, mediated by p38 MAPK signaling pathway, which was the possible mechanism for STYK1-mediated pancreatic cancer cell proliferation and migration. In summary, our results showed that STYK1 might be a prognostic marker for pancreatic cancer patients and might be a novel strategy for the treatment of pancreatic cancer.

Prediction and Validation of Hub Genes Associated with Colorectal Cancer by Integrating PPI Network and Gene Expression Data

Although hundreds of colorectal cancer- (CRC-) related genes have been screened, the significant hub genes still need to be further identified. The aim of this study was to identify the hub genes based on protein-protein interaction network and uncover their clinical value. Firstly, 645 CRC patients' data from the Tumor Cancer Genome Atlas were downloaded and analyzed to screen the differential expression genes (DEGs). And then, the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis was performed, and PPI network of the DEGs was constructed by Cytoscape software. Finally, four hub genes (CXCL3, ELF5, TIMP1, and PHLPP2) were obtained from four subnets and further validated in our clinical setting and TCGA dataset. The results showed that mRNA expression of CXCL3, ELF5, and TIMP1 was increased in CRC tissues, whereas PHLPP2 mRNA expression was decreased. More importantly, high expression of CXCL3, ELF5, and TIMP1 was significantly associated with lymphatic invasion, distance metastasis, and advanced tumor stage. In addition, a shorter overall survival was observed in patients with increased CXCL3, TIMP1, and ELF5 expression and decreased PHLPP2 expression. In conclusion, the four hub genes screened by our strategy could serve as novel biomarkers for prognosis prediction of CRC patients.

Identification of six polymorphisms as novel susceptibility loci for ischemic or hemorrhagic stroke by exome-wide association studies

In this study, we performed exome-wide association studies (EWASs) to identify genetic variants that confer susceptibility to ischemic stroke, intracerebral hemorrhage (ICH), or subarachnoid hemorrhage (SAH). EWAS for ischemic stroke was performed using 1,575 patients with this condition and 9,210 controls, and EWASs for ICH and SAH were performed using 673 patients with ICH, 265 patients with SAH and 9,158 controls. Analyses were performed with Illumina HumanExome-12 DNA Analysis BeadChip or Infinium Exome-24 BeadChip arrays. The relation of allele frequencies for 41,339 or 41,332 single nucleotide polymorphisms (SNPs) that passed quality control to ischemic or hemorrhagic stroke, respectively, was examined with Fisher's exact test. Based on Bonferroni's correction, a P-value of <1.21x10-6 was considered statistically significant. EWAS for ischemic stroke revealed that 77 SNPs were significantly associated with this condition. Multivariable logistic regression analysis with adjustment for age, sex and the prevalence of hypertension and diabetes mellitus revealed that 4 of these SNPs [rs3212335 of GABRB3 (P=0.0036; odds ratio, 1.29), rs147783135 of TMPRSS7 (P=0.0024; odds ratio, 0.37), rs2292661 of PDIA5 (P=0.0054; odds ratio, 0.35) and rs191885206 of CYP4F12 (P=0.0082; odds ratio, 2.60)] were related (P<0.01) to ischemic stroke. EWASs for ICH or SAH revealed that 48 and 12 SNPs, respectively, were significantly associated with these conditions. Multivariable logistic regression analysis with adjustment for age, sex and the prevalence of hypertension revealed that rs138533962 of STYK1 (P<1.0x10-23; odds ratio, 111.3) was significantly (P<2.60x10-4) associated with ICH and that rs117564807 of COL17A1 (P=0.0009; odds ratio, 2.23x10-8) was significantly (P<0.0010) associated with SAH. GABRB3, TMPRSS7, PDIA5 and CYP4F12 may thus be novel susceptibility loci for ischemic stroke, whereas STYK1 and COL17A1 may be such loci for ICH and SAH, respectively.

STYK1 promotes epithelial-mesenchymal transition and tumor metastasis in human hepatocellular carcinoma through MEK/ERK and PI3K/AKT signaling

Serine/threonine/tyrosine kinase 1 (STYK1) is known to be involved in tumor progression. However, its molecular role and mechanism in hepatocellular carcinoma (HCC) remains unknown. We evaluated the effect of STYK1 expression in HCC tissues and investigated the underlying mechanisms associated with progression. HCC tissues expressed greater levels of STYK1 than paired non-tumor tissues. Patients with HCC expressing low levels of STYK1 showed both, greater disease-free (p < 0.0001) and overall (p = 0.0004) survival than those expressing high levels of STYK1. Decreased expression of STYK1 was significantly associated with decreased cell proliferation, reduced migratory capability, and reduced invasive capability. Overexpression of STYK1 was significantly associated with increased cell proliferation, migratory capability, and invasive capability in vitro, as well as increased volume of tumor, weight of tumor, and number of pulmonary metastases in vivo. Furthermore, STYK1's mechanism of promoting cancer cell mobility and epithelial-mesenchymal transition (EMT) was found to be via the MEK/ERK and PI3K/AKT pathways, resulting in increased expression of mesenchymal protein markers: snail, fibronectin, and vimentin, and decreased E-cadherin expression. Our results suggest that STYK1 acts as an oncogene by inducing cell invasion and EMT via the MEK/ERK and PI3K/AKT signaling pathways and it therefore may be a potential therapeutic target in HCC.

A20 suppresses hepatocellular carcinoma proliferation and metastasis through inhibition of Twist1 expression

Background

Aberrant expression of A20 has been reported in several human malignancies including hepatocellular carcinoma (HCC). However, its clinical relevance and potential role in HCC remain unknown.

Methods

Quantitative PCR, Western blots and immunohistochemistry analyses were used to quantify A20 expression in HCC samples and cell lines. The correlation of A20 expression with clinicopathologic features was analyzed in a cohort containing 143 patients with primary HCC. Kaplan-Meier curves were used to evaluate the association between A20 expression and patient survival. Functional studies were performed to determine the effects of A20 on proliferation and metastasis of HCC cells in vitro and in vivo.

Results

Expression of A20 was increased in HCC tissues and cell lines. Increased expression of A20 was negatively correlated with the tumor size, TNM stage, tumor thrombus formation, capsular invasion and serum AFP levels. Patients with higher A20 expression had a prolonged disease-free survival and overall survival than those with lower A20 expression. Forced expression of A20 significantly inhibited the proliferative and invasive properties of HCC cells both in vitro and in vivo, whereas knockdown of A20 expression showed the opposite effects. Further studies revealed that expression of A20 was inversely correlated with Twist1 levels and NF-κB activity in HCC tissues and cell lines. A20-induced suppression of proliferation and migration of HCC cells were mainly mediated through inhibition of Twist1 expression that was regulated at least partly by A20-induced attenuation of NF-κB activity.

Conclusions

Our results demonstrate that A20 plays a negative role in the development and progression of HCC probably through inhibiting Twist1 expression. A20 may serve as a novel prognostic biomarker and potential therapeutic target for HCC patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-015-0454-6) contains supplementary material, which is available to authorized users.