HAX-1 promotes the migration and invasion of hepatocellular carcinoma cells through the induction of epithelial-mesenchymal transition via the NF-κB pathway

HAX1 is a novel binding partner of Che-1/AATF. Implications in oxidative stress cell response

HAX1 is a multifunctional protein involved in the antagonism of apoptosis in cellular response to oxidative stress. In the present study we identified HAX1 as a novel binding partner for Che-1/AATF, a pro-survival factor which plays a crucial role in fundamental processes, including response to multiple stresses and apoptosis. HAX1 and Che-1 proteins show extensive colocalization in mitochondria and we demonstrated that their association is strengthened after oxidative stress stimuli. Interestingly, in MCF-7 cells, resembling luminal estrogen receptor (ER) positive breast cancer, we found that Che-1 depletion correlates with decreased HAX1 mRNA and protein levels, and this event is not significantly affected by oxidative stress induction. Furthermore, we observed an enhancement of the previously reported interaction between HAX1 and estrogen receptor alpha (ERα) upon H2O2 treatment. These results indicate the two anti-apoptotic proteins HAX1 and Che-1 as coordinated players in cellular response to oxidative stress with a potential role in estrogen sensitive breast cancer cells.

Long Noncoding RNA Cytoskeleton Regulator RNA Suppresses Apoptosis in Hepatoma Cells by Modulating the miR-125a-5p/HS1-Associated Protein X-1 Axis to Induce Caspase-9 Inactivation

Background/Aims

The involvement of long noncoding RNAs in the carcinogenesis of hepatocellular carcinoma (HCC) has been well documented by substantial evidence. However, whether cytoskeleton regulator RNA (CYTOR) could affect the progression of HCC remains unclear.

Methods

The relative expression of CYTOR, miR-125a-5p and HS1-associated protein X-1 (HAX-1) mRNA in HCC cells were determined via quantitative real-time polymerase chain reaction. The viability of treated HCC cells was measured by Cell Counting Kit-8 assay. Cell apoptosis was estimated by flow cytometry analysis, assessment of caspase-9 activity and terminal deoxynucleotidyl transferase dUTP nick-end labeling staining, and Western blot of apoptosis-related proteins. The interplay between CYTOR or HAX-1 and miR-125a-5p was validated by dual-luciferase reporter assay.

Results

CYTOR was upregulated and miR-125a-5p was downregulated in HCC cells. CYTOR silencing inhibited cell proliferation and promoted cell apoptosis in HepG2 and SMMC-7721 cells. miR-125a-5p was sponged and negatively regulated by CYTOR, and HAX-1 was directly targeted and negatively modulated by miR-125a-5p. Overexpression of miR-125a-5p enhanced the repressive effects of CYTOR knockdown on HCC cells, and knockdown of HAX-1 enhanced the inhibitory effects of miR-125a-5p mimics on HCC cells.

Conclusions

CYTOR silencing facilitates HCC cell apoptosis in vitro via the miR-125a-5p/HAX-1 axis.

NOD1 cooperates with HAX-1 to promote cell migration in a RIPK2- and NF-ĸB-independent manner

The human Nod-like receptor protein NOD1 is a well-described pattern-recognition receptor (PRR) with diverse functions. NOD1 associates with F-actin and its protein levels are upregulated in metastatic cancer cells. A hallmark of cancer cells is their ability to migrate, which involves actin remodelling. Using chemotaxis and wound healing assays, we show that NOD1 expression correlated with the migration rate and chemotactic index in the cervical carcinoma cell line HeLa. The effect of NOD1 in cell migration was independent of the downstream kinase RIPK2 and NF-ĸB activity. Additionally, NOD1 negatively regulated the phosphorylation status of cofilin, which inhibits actin turnover. Co-immunoprecipitation assays identified HCLS1-associated protein X-1 (HAX-1) as a previously unknown interaction partner of NOD1. Silencing of HAX-1 expression reduced the migration behaviour to similar levels as NOD1 knockdown, and simultaneous knockdown of NOD1 and HAX-1 showed no additive effect, suggesting that both proteins act in the same pathway. In conclusion, our data revealed an important role of the PRR NOD1 in regulating cell migration as well as chemotaxis in human cervical cancer cells and identified HAX-1 as a protein that interacts with NOD1 and is involved in this signalling pathway.

HAX1: A versatile, intrinsically disordered regulatory protein

HAX1 is a relatively small, ubiquitously expressed, predominantly mitochondrial, intrinsically disordered protein. It has been implicated in the regulation of apoptosis, cell migration, calcium cycling, proteostasis, angiogenesis, autophagy and translation. A wide spectrum of functions, numerous interactions and still elusive molecular mechanisms of action make HAX1 an intriguing subject of research. Moreover, HAX1 is involved in the pathogenesis of diseases; its deficiency leads to neutropenia and its overexpression is associated with cancer. In this review we aim to describe the characteristics of HAX1 gene and protein, and comprehensively discuss its multiple functions, highlighting the emerging role of HAX1 in protection from stress and apoptosis through maintaining cellular proteostasis and homeostasis.

PRSS2 regulates EMT and metastasis via MMP-9 in gastric cancer

Serine protease 2 (PRSS2) is upregulated in gastric cancer tissues, correlates with poor prognosis and promotes migration and invasion of gastric cancer cells. However, the exact mechanism by which PRSS2 promotes metastasis in gastric cancer is unclear. We examined serum PRSS2 levels in healthy controls and gastric cancer patients by enzyme linked immunosorbent assay (ELISA) and analyzed the correlation between PRSS2 serum level with the clinicopathological characteristics of gastric cancer patients and matrix metalloproteinase-9 (MMP-9) expression. A lentiviral MMP-9 overexpression vector was constructed and used to transfect gastric cancer cells with stable silencing of PRSS2, and migration, invasion and epithelial-mesenchymal transition (EMT) of gastric cancer cells were examined. High serum PRSS2 levels were detected in gastric cancer patients and associated with lymphatic metastasis and TNM stage. Serum PRSS2 was positively correlated with serum MMP-9 level. PRSS2 silencing inhibited EMT, and knock-down of PRSS2 partially abrogated cell metastasis and EMT caused by overexpression of MMP-9. These results suggest that PRSS2 promotes the migration and invasion of gastric cancer cells through EMT induction by MMP-9. Our findings suggest that PRSS2 may be a potential early diagnostic marker and therapeutic target of gastric cancer.

Hax1 regulate focal adhesion dynamics through IQGAP1

Cell migration is a highly orchestrated process requiring the coordination between the cytoskeleton, cell membrane and extracellular matrix adhesions. Our previous study demonstrated that Hax1 interacts with EB2, a microtubule end-binding protein, and this interaction regulate cell migration in keratinocytes. However, little is known about the underlying regulatory mechanism. Here, we show that Hax1 links dynamic focal adhesions to regulate cell migration via interacting with IQGAP1, a multidomain scaffolding protein, which was identified by affinity purification coupled with LC-MS/MS. Biochemical characterizations revealed that C-terminal region of Hax1 and RGCT domain of IQGAP1 are the most critical binding determinants for its interaction. IQGAP1/Hax1 interaction is essential for cell migration in MCF7 cells. Knockdown of HAX1 not only stabilizes focal adhesions, but also impairs the accumulation of IQGAP in focal adhesions. Further study indicates that this interaction is critical for maintaining efficient focal adhesion turnover. Perturbation of the IQGAP1/Hax1 interaction in vivo using a membrane-permeable TAT-RGCT peptide results in impaired focal adhesion turnover, thus leading to inhibition of directional cell migration. Together, our findings unravel a novel interaction between IQGAP1 and Hax1, suggesting that IQGAP1 association with Hax1 plays a significant role in focal adhesion turnover and directional cell migration. Video Abstract.

Multifaceted role of NF-κB in hepatocellular carcinoma therapy: Molecular landscape, therapeutic compounds and nanomaterial approaches

The predominant kind of liver cancer is hepatocellular carcinoma (HCC) that its treatment have been troublesome difficulties for physicians due to aggressive behavior of tumor cells in proliferation and metastasis. Moreover, stemness of HCC cells can result in tumor recurrence and angiogenesis occurs. Another problem is development of resistance to chemotherapy and radiotherapy in HCC cells. Genomic mutations participate in malignant behavior of HCC and nuclear factor-kappaB (NF-κB) has been one of the oncogenic factors in different human cancers that after nuclear translocation, it binds to promoter of genes in regulating their expression. Overexpression of NF-κB has been well-documented in increasing proliferation and invasion of tumor cells and notably, when its expression enhances, it induces chemoresistance and radio-resistance. Highlighting function of NF-κB in HCC can shed some light on the pathways regulating progression of tumor cells. The first aspect is proliferation acceleration and apoptosis inhibition in HCC cells mediated by enhancement in expression level of NF-κB. Moreover, NF-κB is able to enhance invasion of HCC cells via upregulation of MMPs and EMT, and it triggers angiogenesis as another step for increasing spread of tumor cells in tissues and organs. When NF-κB expression enhances, it stimulates chemoresistance and radio-resistance in HCC cells and by increasing stemness and population of cancer-stem cells, it can provide the way for recurrence of tumor. Overexpression of NF-κB mediates therapy resistance in HCC cells and it can be regulated by non-coding RNAs in HCC. Moreover, inhibition of NF-κB by anti-cancer and epigenetic drugs suppresses HCC tumorigenesis. More importantly, nanoparticles are considered for suppressing NF-κB axis in cancer and their prospectives and results can also be utilized for treatment of HCC. Nanomaterials are promising factors in treatment of HCC and by delivery of genes and drugs, they suppress HCC progression. Furthermore, nanomaterials provide phototherapy in HCC ablation.

Gentianella acuta-derived Gen-miR-1 suppresses myocardial fibrosis by targeting HAX1/HMG20A/Smads axis to attenuate inflammation in cardiac fibroblasts

BACKGROUND

Continuous activation and inflammation of cardiac fibroblasts (CFs) are essential for myocardial fibrosis. Gentianella acuta (Michx.) Hiitonen (G. acuta), that contains xanthones with cardioprotective properties, a typical healthful herb extensively used to treat cardiovascular diseases in Inner Mongolia region of China. However, it remains unknown whether or not G. acuta-derived miRNAs can shield CFs from activation by inflammatory stimulation. Therefore, we tend to investigated the role and core mechanism of G. acuta-derived Gen-miR-1 in regulating fibrosis and inflammation induced by TGF-β1.

METHODS

An animal model for myocardial infarction was built by subcutaneous injections of ISO and treated with Gen-miR-1 using intragastric administration. The protective effect of Gen-miR-1 on the heart was assessed by pathomorphological analysis of myocardial fibrosis. Using loss- and gain-of-function approaches, Gen-miR-1 regulation of HAX1/HMG20A/Smads axis was investigated by utilizing luciferase assay, Western blot, co-immunoprecipitation, etc. RESULTS: Screened and identified Gen-miR-1 from G. acuta. Gen-miR-1 can enter the mouse body, and markedly inhibit myocardial infarction induced by ISO in mice, as well as suppresses fibrosis in CFs and attenuates the inflammatory response elicited by TGF-β1 in vitro. Gen-miR-1 downregulates HCLS1-related Protein X-1 (HAX1) expression through direct binding to the 3' UTR of HAX1, which in turn relieves HAX1 from promoting the expression of high-mobility group protein 20A (HMG20A), whereas HMG20A downregulation restrains the activation of TGF-β1/Smads signaling pathways, subsequently resulting in a decrease of fibrosis and in facilitating CFs anti-inflammatory effects induced by Gen-miR-1 in the context of CFs activation induced by TGF-β1.

CONCLUSIONS

Our results first uncovered unique bioactive components in G. acuta and elucidated the molecular mechanism by which G. acuta-derived Gen-miR-1 suppress inflammation and myocardial fibrosis. These findings expand our understanding of G. acuta's therapeutic properties and bioactive constituents. Gen-miR-1-regulated HAX1/HMG20A/Smads axis will be one potential therapeutic target for cardiac remodeling.

Non-coding RNAs regulating epithelial-mesenchymal transition: Research progress in liver disease

Chronic liver injury could gradually progress to liver fibrosis, cirrhosis, and even hepatic carcinoma without effective treatment. The massive production and activation of abnormal cell differentiation is vital to the procession of liver diseases. Epithelial-mesenchymal transformation (EMT) is a biological process in which differentiated epithelial cells lose their epithelial characteristics and acquire mesenchymal cell migration capacity. Emerging evidence suggests that EMT not only occurs in the process of hepatocellular carcinogenesis, but also appears in liver cells transforming to myofibroblasts, a core event of liver disease. Non-coding RNA (ncRNA) such as microRNA (miRNA), long non-coding RNA (lncRNA) and circular RNA (circRNA) are important regulatory factors in EMT, which can regulate target gene expression by binding with RNA single-stranded. Various studies had shown that ncRNA regulation of EMT plays a key role in liver disease development, and many effective ncRNAs have been identified as promising biomarkers for the diagnosis and treatment of liver disease. In this review, we focus on the relationship between the different ncRNAs and EMT as well as the specific molecular mechanism in the liver diseases to enrich the pathological progress of liver diseases and provide reference for the treatment of liver diseases.

DNMT1-induced miR-378a-3p silencing promotes angiogenesis via the NF-κB signaling pathway by targeting TRAF1 in hepatocellular carcinoma

BACKGROUND

Angiogenesis plays an important role in the occurrence, development and metastasis of hepatocellular carcinoma (HCC). According to previous studies, miR-378a participates in tumorigenesis and tumor metastasis, but its exact role in HCC angiogenesis remains poorly understood.

METHODS

qRT-PCR was used to investigate the expression of miR-378a-3p in HCC tissues and cell lines. The effects of miR-378a-3p on HCC in vitro and in vivo were examined by Cell Counting Kit-8 (CCK-8), Transwell, tube formation and Matrigel plug assays, RNA sequencing, bioinformatics, luciferase reporter, immunofluorescence and chromatin immunoprecipitation (ChIP) assays were used to detect the molecular mechanism by which miR-378a-3p inhibits angiogenesis.

RESULTS

We confirmed that miR-378a-3p expression was significantly downregulated and associated with higher microvascular density (MVD) in HCC; miR-378a-3p downregulation indicated a short survival time in HCC patients. miR-378a-3p knockdown led to a significant increase in angiogenesis in vitro and in vivo. We found that miR-378a-3p directly targeted TNF receptor associated factor 1 (TRAF1) to attenuate NF-κB signaling, and then downregulated secreted vascular endothelial growth factor. DNA methyltransferase 1 (DNMT1)-mediated hypermethylation of miR-378a-3p was responsible for downregulating miR-378a-3p. Moreover, a series of investigations indicated that p65 initiated a positive feedback loop that could upregulate DNMT1 to promote hypermethylation of the miR-378a-3p promoter.

CONCLUSION

Our study indicates a novel DNMT1/miR-378a-3p/TRAF1/NF-κB positive feedback loop in HCC cells, which may become a potential therapeutic target for HCC.

The Role of the Hematopoietic Cell-Specific Protein 1-Associated Protein X-1 in Human Papillomavirus 16 E2-Induced Human Cervical Squamous Carcinoma Cell Apoptosis via a Mitochondria-Dependent Pathway

OBJECTIVES

Human papillomavirus 16 (HPV 16) E2 is a transcriptional regulator that plays a key role in regulating a variety of biological responses. Hematopoietic cell-specific protein 1-related protein X-1 (HAX-1) is a mitochondrial membrane protein, and the HAX-1 gene is involved in the occurrence, growth, invasion, and metastasis of various human malignant tumors. The purpose of this study was to investigate the relationships among HPV 16 E2, the role of HAX-1 gene, and the underlying intracellular apoptotic mechanism of human cervical squamous carcinoma cells (C33a and SiHa).

METHODS

In this study, HAX-1 expression was examined using real-time polymerase chain reaction, Western blot, and immunohistochemical staining analysis. Apoptosis of cells was assessed by flow cytometry. The mitochondrial function was assessed by the mitochondrial copy number, reactive oxygen species (ROS) generation, the mitochondrial membrane potential (ΔΨm), and mitochondrial morphology.

RESULTS

Our study demonstrated that the expression of the HAX-1 gene was significantly increased in human cervical carcinoma tissues relative to noncancerous cervix tissues. HPV 16 E2 inhibited HAX-1 protein expression. Overexpression of HAX-1 increased the mitochondrial copy number, decreased the production of ROS, and maintained the integrity of the mitochondrial membrane and morphology. So, enhanced expression of the HAX-1 gene could abrogate the HPV 16 E2-induced cell apoptosis.

CONCLUSION

Therefore, these data support a mechanism that HAX-1 plays a crucial role in HPV 16 E2-induced human cervical squamous carcinoma cell apoptosis in a mitochondrial-dependent manner.

Study of the host specificity of PB1-F2-associated virulence

Influenza A viruses cause important diseases in both human and animal. The PB1-F2 protein is a virulence factor expressed by some influenza viruses. Its deleterious action for the infected host is mostly described in mammals, while the available information is scarce in avian hosts. In this work, we compared the effects of PB1-F2 in avian and mammalian hosts by taking advantage of the zoonotic capabilities of an avian H7N1 virus. In vitro, the H7N1 virus did not behave differently when PB1-F2 was deficient while a H3N2 virus devoid of PB1-F2 was clearly less inflammatory. Likewise, when performing in vivo challenges of either chickens or embryonated eggs, with the wild-type or the PB1-F2 deficient virus, no difference could be observed in terms of mortality, host response or tropism. PB1-F2 therefore does not appear to play a major role as a virulence factor in the avian host. However, when infecting NF-κB-luciferase reporter mice with the H7N1 viruses, a massive PB1-F2-dependent inflammation was quantified, highlighting the host specificity of PB1-F2 virulence. Surprisingly, a chimeric 7:1 H3N2 virus harboring an H7N1-origin segment 2 (i.e. expressing the avian PB1-F2) induced a milder inflammatory response than its PB1-F2-deficient counterpart. This result shows that the pro-inflammatory activity of PB1-F2 is governed by complex mechanisms involving components from both the virus and its infected host. Thus, a mere exchange of segment 2 between strains is not sufficient to transmit the deleterious character of PB1-F2.

Role of LncRNAs in the Epithelial-Mesenchymal Transition in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a type of primary liver cancer with a high incidence and mortality rate. HCC develops insidiously, and most newly diagnosed cases are in the middle and advanced stages. The epithelial-mesenchymal transition (EMT) is a vital mechanism underlying metastasis in patients with advanced HCC. EMT is a multistep and complex procedure. The promotion and inhibition of EMT directly affect the migration and invasion of HCC. LncRNAs are involved in the epigenetic modification of genes, regulation of gene transcription, and posttranslational modification of proteins. LncRNAs also play important roles in regulating EMT progression in HCC and are promising biomarkers and therapeutic targets. This review focused on summarizing the mechanism by which lncRNAs regulate EMT in HCC. In particular, lncRNAs were reported to primarily act as RNA sponges, and the regulation of EMT involves major signaling pathways. Finally, we reviewed the mechanisms by which lncRNAs are involved in drug resistance and discussed the clinical prospects and potential challenges of utilizing lncRNAs to treat HCC.

LncRNA HOXA-AS3 promotes gastric cancer progression by regulating miR-29a-3p/LTβR and activating NF-κB signaling

BACKGROUND

Gastric cancer (GC) is among the most common and deadliest cancers globally. Many long non-coding RNAs (lncRNAs) are key regulators of GC pathogenesis. This study aimed to define the role of HOXA-AS3 in this oncogenic context.

METHODS

Levels of HOXA-AS3 expression in GC were quantified via qPCR. The effects of HOXA-AS3 knockdown on GC cells function were evaluated in vitro using colony formation assays, wound healing assays and transwell assays. Subcutaneous xenograft and tail vein injection tumor model systems were generated in nude mice to assess the effects of this lncRNA in vivo. The localization of HOXA-AS3 within cells was confirmed by subcellular fractionation, and predicted microRNA (miRNA) targets of this lncRNA and its ability to modulate downstream NF-κB signaling in GC cells were evaluated via luciferase-reporter assays, immunofluorescent staining, and western blotting.

RESULTS

GC cells and tissues exhibited significant HOXA-AS3 upregulation (P < 0.05), and the levels of this lncRNA were found to be correlated with tumor size, lymph node status, invasion depth, and Helicobacter pylori infection status. Knocking down HOXA-AS3 disrupted GC cell proliferation, migration, and invasion in vitro and tumor metastasis in vivo. At a mechanistic level, we found that HOXA-AS3 was able to sequester miR-29a-3p, thereby regulating the expression of LTβR and modulating NF-κB signaling in GC.

CONCLUSION

HOXA-AS3/miR-29a-3p/LTβR/NF-κB regulatory axis contributes to the progression of GC, thereby offering novel target for the prognosis and treatment of GC.

Identification of protein/mRNA network involving the PSORS1 locus gene CCHCR1 and the PSORS4 locus gene HAX1

CCHCR1 (Coiled-Coil alpha-Helical Rod 1), maps to chromosomal region 6p21.3, within the major psoriasis susceptibility locus PSORS1. CCHCR1 itself is a plausible psoriasis candidate gene, however its role in psoriasis pathogenesis remains unclear. We previously demonstrated that CCHCR1 protein acts as a cytoplasmic docking site for RNA polymerase II core subunit 3 (RPB3) in cycling cells, suggesting a role for CCHCR1 in vesicular trafficking between cellular compartments. Here, we report a novel interaction between CCHCR1 and the RNA binding protein HAX1. HAX1 maps to chromosomal region 1q21.3 within the PSORS4 locus and is over-expressed in psoriasis. Both CCHCR1 and HAX1 share subcellular co-localization with mitochondria, nuclei and cytoplasmic vesicles as P-bodies. By a series of ribonucleoprotein immunoprecipitation (RIP) assays, we isolated a pool of mRNAs complexed with HAX1 and/or CCHCR1 proteins. Among the mRNAs complexed with both CCHCR1 and HAX1 proteins, there are Vimentin mRNA, previously described to be bound by HAX1, and CAMP/LL37 mRNA, whose gene product is over-expressed in psoriasis.

HAX1 enhances the survival and metastasis of non-small cell lung cancer through the AKT/mTOR and MDM2/p53 signaling pathway

Background

HS‐1‐associated protein‐1 (HAX1) has been reported to be overexpressed in non‐small cell lung cancer (NSCLC) tissues. However, the underlying mechanism of HAX1 in NSCLC has not previously been demonstrated. The present study investigated the role and underlying mechanism of HAX1 in NSCLC.

Methods

The HAX1 expression were confirmed in NSCLC tissues through TCGA database and qRT‐PCR. Moreover, we performed qRT‐PCR, Western blotting, Transwell assays, TUNEL assays and so on to evaluate the role of HAX1 in A549 and H1299 cell lines.

Results

mRNA expression of HAX1 was overexpressed in NSCLC tissues compared to adjacent normal tissues according to The Cancer Genome Atlas (TCGA) database. QRT‐PCR assays showed that HAX1 mRNA expression was upregulated in NSCLC tissues. The high HAX1 mRNA levels were found to be positively associated with tumor size, TNM stage and lymphatic metastasis. Silencing of HAX1 promoted apoptosis and reduced invasion of A549 and H1299 cells by inhibiting the AKT/mTOR and MDM2/P53 signal pathway. AKT agonist SC79 could inhibit apoptosis and promote proliferation, migration and invasion of A549 and H1299 cells transfected with si‐HAX1.

Conclusions

The present study provided a better understanding of HAX1 mechanism in NSCLC and potential therapeutic target for NSCLC.

Mining Database for the Expression and Clinical Significance of NF-κB Family in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the deadliest diseases affecting humans. Its incidence has been increasing over the last decade. It is characterized by poor prognosis as well as lack of therapeutic regimens for patients in the advanced stages. It is therefore important to develop effective biomarkers for diagnosis, prognosis, and immunotherapy of HCC. Research suggests that the NF-κB family plays vital roles in immune response, inflammation, tumorigenesis, and the progress of malignancy in various cancers. However, its role in HCC remains unidentified. Methodology. The expression and clinical significance of the NF-κB family in HCC were analyzed using several bioinformatics tools including UALCAN, The Human Protein Atlas, GEPIA, GSCALite, David, GeneMANIA, and TIMER.

Results

The mRNA expression levels of RelA, RelB, NF-κB1, and NF-κB2 were significantly elevated in HCC. The mRNA levels of RelB and NF-κB2 were significantly upregulated in HCC tissues compared to normal liver tissues in subgroup analyses based on patient's race, gender, age, weight, tumor grade, cancer stage, and nodal metastasis status. Moreover, HCC patients with elevated levels of RelB and NF-κB2 had a worse overall survival and disease-free survival. Methylation downregulated the expressions of RelA, RelB, and NF-κB1 in HCC. NF-κB family was also significantly involved in various hallmark cancer-related pathways such as the apoptosis, EMT, RTK, and cell cycle pathways. Similarly, the expression of RelB and NF-κB2 was positively correlated with the abundance of immune cells and the expression of immune biomarkers. Several kinase and miRNA targets of RelB and NF-κB2 were also identified.

Conclusion

RelB and NF-κB2 are potential biomarkers for the diagnosis, prognosis, and immunotherapy of HCC.

BDH2 triggers ROS-induced cell death and autophagy by promoting Nrf2 ubiquitination in gastric cancer

Background

3-Hydroxy butyrate dehydrogenase 2 (BDH2) is a short-chain dehydrogenase/reductase family member that plays a key role in the development and pathogenesis of human cancers. However, the role of BDH2 in gastric cancer (GC) remains largely unclear. Our study aimed to ascertain the regulatory mechanisms of BDH2 in GC, which could be used to develop new therapeutic strategies.

Methods

Western blotting, immunohistochemistry, and RT-PCR were used to investigate the expression of BDH2 in GC specimens and cell lines. Its correlation with the clinicopathological characteristics and prognosis of GC patients was analysed. Functional assays, such as CCK-8 and TUNEL assays, transmission electron microscopy, and an in vivo tumour growth assay, were performed to examine the proliferation, apoptosis, and autophagy of GC cells. Related molecular mechanisms were clarified by luciferase reporter, coimmunoprecipitation, and ubiquitination assays.

Results

BDH2 was markedly downregulated in GC tissues and cells, and the low expression of BDH2 was associated with poor survival of GC patients. Functionally, BDH2 overexpression significantly induced apoptosis and autophagy in vitro and in vivo. Mechanistically, BDH2 promoted Keap1 interaction with Nrf2 to increase the ubiquitination level of Nrf2. Ubiquitination/degradation of Nrf2 inhibited the activity of ARE to increase accumulation of reactive oxygen species (ROS), thereby inhibiting the phosphorylation levels of Akt^Ser473 and mTOR^Ser2448.

Conclusions

Our study indicates that BDH2 is an important tumour suppressor in GC. BDH2 regulates intracellular ROS levels to mediate the PI3K/Akt/mTOR pathway through Keap1/Nrf2/ARE signalling, thereby inhibiting the growth of GC.

SNHG16/miR-605-3p/TRAF6/NF-κB feedback loop regulates hepatocellular carcinoma metastasis

The mechanism by which miR‐605‐3p regulates hepatocellular carcinoma (HCC) metastasis has not been clarified. In this study, we found that miR‐605‐3p was down‐regulated in HCC and that low miR‐605‐3p expression was associated with tumour thrombus and tumour satellites. HCC patients with low miR‐605‐3p expression showed shorter overall survival and disease‐free survival after surgery. Overexpression of miR‐605‐3p inhibited epithelial‐mesenchymal transition and metastasis of HCC through NF‐κB signalling by directly inhibiting expression of TRAF6, while silencing of miR‐605‐3p had the opposite effect. We also found that SNHG16 directly bound to miR‐605‐3p as a competing endogenous RNA. Mechanistically, high expression of SNHG16 promoted binding to miR‐605‐3p and inhibited its activity, which led to up‐regulation of TRAF6 and sustained activation of the NF‐κB pathway, which in turn promoted epithelial‐mesenchymal transition and metastasis of HCC. TRAF6 increased SNHG16 promoter activity by activating NF‐κB, thereby promoting the transcriptional expression of SNHG16 and forming a positive feedback loop that aggravated HCC malignancy. Our findings reveal a mechanism for the sustained activation of the SNHG16/miR‐605‐3p/TRAF6/NF‐κB feedback loop in HCC and provide a potential target for a new HCC treatment strategy.

ZBTB7A promotes migration, invasion and metastasis of human breast cancer cells through NF-κB-induced epithelial-mesenchymal transition in vitro and in vivo

It has been generally confirmed that zinc finger and BTB domain containing 7A (ZBTB7A) plays an important role in the occurrence and progression of malignant tumours, but the promotion or inhibition effect is related to tumour type. The mechanism between ZBTB7A and breast cancer is not well understood, so further research is needed. In this study, we first investigated the expression of ZBTB7A in tissue samples of clinical breast cancer patients, MDA-MB-231, MCF-7 and MCF-10A cells. Second, we overexpressed the ZBTB7A in MCF-7 cells and silenced the ZBTB7A in MDA-MB-231 cells using lentivirus transfection technology, respectively, and verified the effect of ZBTB7A on migration and invasion of breast cancer cell lines through in vitro cell function experiments, such as wound-healing assay, migration and invasion assay, quantitative real time reverse transcriptase (qRT-PCR) and western blot. Then, the correlation between the above influences, epithelial-mesenchymal transition (EMT) and NF-κB was analysed. Finally, in vivo tumour transplantation model in nude mice was established to verified the effect of ZBTB7A on metastasis of breast cancer MDA-MB-231 cells. In conclusion, ZBTB7A is highly expressed in cancer tissue, breast cancer cell line MDA-MB-231 and MCF-7. Meanwhile, the high expression of ZBTB7A may promote cell migration, invasion and tumour metastasis, which may be related to EMT events by regulating NF-κB.

Rafoxanide promotes apoptosis and autophagy of gastric cancer cells by suppressing PI3K /Akt/mTOR pathway

Rafoxanide is commonly used as anti-helminthic medicine in veterinary medicine, a main compound of salicylanilide. Previous studies have reported that rafoxanide, as an inhibitor of BRAF V600E mutant protein, inhibits the growth of colorectal cancer, multiple myeloma, and skin cancer. However, its therapeutic effect on gastric cancer (GC) and the potential mechanism has not been investigated. Here, we have found that rafoxanide inhibited the proliferation of GC cells in vitro, arrested the cell cycle in the G0/G1 phase, and promoted apoptosis and autophagy in GC cells. Treatment with specific autophagy inhibitor 3-methyladenine drastically inhibited the apoptotic cell death effect by suppressing the switch from autophagy to apoptosis. Mechanistically, we found that rafoxanide inhibited the growth of GC cells in vitro by inhibiting the activity of the PI3K/Akt/mTOR signaling pathway. This process induced autophagy, which essentially resulted in the apoptosis of GC cells. Results from subcutaneous implanted tumor models in nude mice also indicated that rafoxanide inhibited the growth of GC cells in vivo. Taken together, our findings revealed that rafoxanide inhibited the growth of GC cells both in vitro and vivo, indicating a potential drug candidate for the treatment of GC.