Regulator of Calcineurin 1 Gene Isoform 4, Down-regulated in Hepatocellular Carcinoma, Prevents Proliferation, Migration, and Invasive Activity of Cancer Cells and Metastasis of Orthotopic Tumors by Inhibiting Nuclear Translocation of NFAT1

Tumor-Intrinsic Galectin-3 Suppresses Melanoma Metastasis

Melanoma poses a poor prognosis with high mortality rates upon metastasis. Exploring the molecular mechanisms governing melanoma progression paves the way for developing novel approaches to control melanoma metastasis and ultimately enhance patient survival rates. Extracellular galectin-3 (Gal-3) has emerged as a pleiotropic promoter of melanoma metastasis, exerting varying activities depending on its interacting partner. However, whether intracellular Gal-3 promotes melanoma aggressive behavior remains unknown. In this study, we explored Gal-3 expression in human melanoma tissues as well as in murine melanoma models to examine its causal role in metastatic behavior. We found that Gal-3 expression is downregulated in metastatic melanoma tissues compared with its levels in primary melanomas. Enforced silencing of Gal-3 in melanoma cells promoted migration, invasion, colony formation, in vivo xenograft growth, and metastasis and activated canonical oncogenic signaling pathways. Moreover, loss of Gal-3 in melanoma cells resulted in upregulated the expression of the prometastatic transcription factor NFAT1 and its downstream metastasis-associated proteins, matrix metalloproteinase 3, and IL-8. Overall, our findings implicate melanoma intracellular Gal-3 as a major determinant of its metastatic behavior and reveal a negative regulatory role for Gal-3 on the expression of NFAT1 in melanoma cells.

Identification of RCAN1's role in hepatocellular carcinoma using single-cell analysis

BACKGROUND

The regulator of calcineurin 1 (RCAN1) is expressed in multiple organs, including the heart, liver, brain, and kidney, and is closely linked to the pathogenesis of cardiovascular diseases, Down syndrome, and Alzheimer's disease. It is also implicated in the development of various organ tumors; however, its potential role in hepatocellular carcinoma (HCC) remains poorly understood. Therefore, the objective of this study was to investigate the potential mechanisms of RCAN1 in HCC through bioinformatics analysis.

METHODS

We conducted a joint analysis based on the NCBI and TCGA databases, integrating both bulk transcriptome and single-cell analyses to examine the principal biological functions of RCAN1 in HCC, as well as its roles related to phenotype, metabolism, and cell communication. Subsequently, an RCAN1-overexpressing cell line was established, and the effects of RCAN1 on tumor cells were validated through in vitro experiments. Moreover, we endeavored to identify potential related drugs using molecular docking and molecular dynamics simulations.

RESULTS

The expression of RCAN1 was found to be downregulated in 19 types of cancer tissues and upregulated in 11 types of cancer tissues. Higher levels of RCAN1 expression were associated with improved patient survival. RCAN1 was predominantly expressed in hepatocytes, macrophages, endothelial cells, and monocytes, and its high expression not only closely correlated with the distribution of cells related to the HCC phenotype but also with the distribution of HCC cells themselves. Additionally, Rcan1 may directly or indirectly participate in metabolic pathways such as alanine, aspartate, and glutamate metabolism, as well as butanoate metabolism, thereby influencing tumor cell proliferation and migration. In vitro experiments confirmed that RCAN1 overexpression promoted apoptosis while inhibiting proliferation and invasion of HCC cells. Through molecular docking of 1615 drugs, we screened brompheniramine as a potential target drug and verified our results by molecular dynamics.

CONCLUSION

In this study, we revealed the relationship between RCAN1 and HCC through bioinformatics methods, verified that RCAN1 can affect the progress of the disease through experiments, and finally identified potential therapeutic drugs through drug molecular docking and molecular dynamics.

Clinical significance of ribosome production factor 2 homolog in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide. Dysregulation of ribosome biogenesis increases the risk of cancer. RPF2 (ribosome production factor 2 homolog), a member of the BRIX family, is involved in ribosome biogenesis. However, the biological functions of RPF2 in HCC remain unclear. This study aims to evaluate the function of RPF2 and its clinical significance in HCC. We collected 45 pairs of HCC/adjacent samples and 291 HCC samples. These samples were used to perform immunohistochemical analysis and western blot. Six cell lines were used to perform western blot, and two of cell lines, SMCC-7721 and SNU449, were subjected to CCK-8, wound healing and transwell assays. Immunofluorescence staining was executed in SMCC-7721 cells. The protein levels of RPF2 were higher in HCC tissues than in adjacent tissues. Immunofluorescence staining showed that the RPF2 protein was located in the nucleuses, especially the nucleolus. Furthermore, the immunohistochemical analysis showed that high expression levels of nuclear RPF2 correlated with poor prognosis, vascular invasion, liver cirrhosis and tumor size. Cell experiments showed that overexpression of RPF2 promoted cell proliferation, migration and invasion, while knockdown of RPF2 tended to show the opposite effect. This is the first report that RPF2 is involved in HCC progression. The levels of RPF2 were significantly high in HCC tumors and had a side effect on prognosis in HCC patients. RPF2 has the potential to be a useful marker for HCC.

CircIQGAP1 regulates RCAN1 and RCAN2 through the mechanism of ceRNA and promotes the growth of malignant glioma

Circular RNA (circRNA) is one of non-coding RNA with specific circular structure, which has been found to be involved in regulating a series of malignant biological behaviors in many malignant tumors. In this study, based on the IDH1 molecular typing of gliomas, we identified a significant downregulation of circRNA (circIQGAP1) expression in IDH1 mutant gliomas by high-throughput sequencing. In 79 tissue samples, we confirmed that circIQGAP1 expression was significantly downregulated in IDH1 mutant gliomas, and that low circIQGAP1 expression was positively associated with better prognosis. Knockdown of circIQGAP1 in glioma cell lines inhibited glioma cell malignancy and conversely overexpression of circIQGAP1 promoted glioma malignancy. circIQGAP1 regulated glioma cell migration, proliferation, invasion and apoptosis through miR-1256/RCAN1/Bax/Bcl-2/Caspase3 and miR-622/RCAN2/Bax/Bcl-2/Caspase3 axes. These results suggest that circIQGAP1 plays an important role in glioma development, promotes tumor growth, and is a potential therapeutic target for glioma.

Loss of hepatic FTCD promotes lipid accumulation and hepatocarcinogenesis by upregulating PPARγ and SREBP2

Background & Aims

Exploiting key regulators responsible for hepatocarcinogenesis is of great importance for the prevention and treatment of hepatocellular carcinoma (HCC). However, the key players contributing to hepatocarcinogenesis remain poorly understood. We explored the molecular mechanisms underlying the carcinogenesis and progression of HCC for the development of potential new therapeutic targets.

Methods

The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) and Genotype-Tissue Expression (GTEx) databases were used to identify genes with enhanced expression in the liver associated with HCC progression. A murine liver-specific Ftcd knockout (Ftcd-LKO) model was generated to investigate the role of formimidoyltransferase cyclodeaminase (FTCD) in HCC. Multi-omics analysis of transcriptomics, metabolomics, and proteomics data were applied to further analyse the molecular effects of FTCD expression on hepatocarcinogenesis. Functional and biochemical studies were performed to determine the significance of loss of FTCD expression and the therapeutic potential of Akt inhibitors in FTCD-deficient cancer cells.

Results

FTCD is highly expressed in the liver but significantly downregulated in HCC. Patients with HCC and low levels of FTCD exhibited worse prognosis, and patients with liver cirrhosis and low FTCD levels exhibited a notable higher probability of developing HCC. Hepatocyte-specific knockout of FTCD promoted both chronic diethylnitrosamine-induced and spontaneous hepatocarcinogenesis in mice. Multi-omics analysis showed that loss of FTCD affected fatty acid and cholesterol metabolism in hepatocarcinogenesis. Mechanistically, loss of FTCD upregulated peroxisome proliferator-activated receptor (PPAR)γ and sterol regulatory element-binding protein 2 (SREBP2) by regulating the PTEN/Akt/mTOR signalling axis, leading to lipid accumulation and hepatocarcinogenesis.

Conclusions

Taken together, we identified a FTCD-regulated lipid metabolic mechanism involving PPARγ and SREBP2 signaling in hepatocarcinogenesis and provide a rationale for therapeutically targeting of HCC driven by downregulation of FTCD.

Impact and implications

Exploiting key molecules responsible for hepatocarcinogenesis is significant for the prevention and treatment of HCC. Herein, we identified formimidoyltransferase cyclodeaminase (FTCD) as the top enhanced gene, which could serve as a predictive and prognostic marker for patients with HCC. We generated and characterised the first Ftcd liver-specific knockout murine model. We found loss of FTCD expression upregulated peroxisome proliferator-activated receptor (PPAR)γ and sterol regulatory element-binding protein 2 (SREBP2) by regulating the PTEN/Akt/mTOR signalling axis, leading to lipid accumulation and hepatocarcinogenesis, and provided a rationale for therapeutic targeting of HCC driven by downregulation of FTCD.

Oncogenic Role of the NFATC2/NEDD4/FBP1 Axis in Cholangiocarcinoma

Nuclear factor of activated T cells 2 (NFATC2) is reported to contribute to the initiation and progression of various cancers; however, its expression and function in cholangiocarcinoma (CCA) tissues remain elusive. Herein, we investigated the expression pattern, clinicopathologic characteristics, cell biological functions, and potential mechanisms of NFATC2 in CCA tissues. Real-time reverse-transcription PCR (RT-qPCR) and immunohistochemistry were performed to analyze the expression of NFATC2 in human CCA tissues. Cell counting kit 8, colony formation, flow cytometry, Western blotting, and Transwell assays, and in vivo xenograft and pulmonary metastasis models, were used to explore the effect of NFATC2 on the proliferation and metastasis of CCA. A dual-luciferase reporter system, oligonucleotide pull-down, chromatin immunoprecipitation, immunofluorescence, and coimmunoprecipitation were performed to reveal the potential mechanisms. We found that NFATC2 was upregulated in CCA tissues and cells, and its aberrantly high levels were associated with a poorer differentiation pattern. Functionally, NFATC2 overexpression promoted CCA cell proliferation and metastasis, whereas knockdown of NFATC2 led to opposite result. Mechanistically, NFATC2 could be enriched in the promoter region of neural precursor cell-expressed developmentally downregulated protein 4 (NEDD4) to facilitate its expression. Furthermore, NEDD4 targeted fructose-1, 6-bisphosphatase 1 (FBP1) and inhibited FBP1 expression via ubiquitination. In addition, silencing NEDD4 rescued the effects of NFATC2 overexpression on CCA cells. NEDD4 was upregulated in human CCA tissues, and its expression levels were positively correlated with those of NFATC2. We thus conclude that NFATC2 promotes the progression of CCA via the NEDD4/FBP1 axis, emphasizing the oncogenic role of NFATC2 in CCA progression.

The RCAN1.4 Metastasis Suppressor Is Hypermethylated at Intron 1 in Thyroid Cancer

Background: Regulator of calcineurin 1.4 (RCAN1.4) is a functionally downregulated metastasis progression suppressor (MPS) in thyroid cancer; however, the mechanisms for RCAN1.4 loss in thyroid cancer have not yet been reported. The RCAN1.4 promoter and gene contain several cytosine-guanine (CG)-rich regions, some of which are reported to be hypermethylated in nonthyroid tissues. We, therefore, hypothesized that RCAN1.4 downregulation in thyroid cancer was in part due to hypermethylation. Methods: Studies were performed in 5 thyroid cancer cell lines (TPC1, FTC133, BCPAP, C643, and 8505C) with different genetic drivers, and in 18 paired normal and thyroid cancer human thyroid cancer tissues. Basal RCAN1.4 messenger RNA (mRNA) and protein levels were assessed in all of the cell lines. Cell lines with lowest RCAN1.4 expression levels were treated with the DNA methyl transferase inhibitor, decitabine. Normal/tumor tissue pairs were analyzed for methylation of three CG-rich regions both by capture of methylated DNA by MBD2 protein and by methylation-specific polymerase chain reaction (MSPCR). Results: In all assessed cell lines, RCAN1.4 mRNA and protein levels increased after decitabine treatment. In silico analysis of the RCAN1.4 gene identified 3 CG-rich regions as possible methylation targets: 1 in the proximal promoter and 2 in intron 1. Hypermethylation of the intron 1 CG-rich regions was identified by both the capture method and MSPCR. In contrast, hypermethylation of the CG-rich region of the proximal promoter was not identified. Gene expression confirmed that hypermethylation in thyroid cancer samples in intron 1 of RCAN1.4 was associated with lower levels of RCAN1.4 mRNA. Finally, the cancer samples demonstrated increased NFE2L3 expression, a downstream marker of functional RCAN1.4 loss. Conclusions: The MPS gene, RCAN1.4, is downregulated in thyroid cancer cells and human thyroid cancer in part by hypermethylation of CG-rich regions in intron 1.

Super-enhancers complexes zoom in transcription in cancer

Super-enhancers (SEs) consist of multiple typical enhancers enriched at high density with transcription factors, histone-modifying enzymes and cofactors. Oncogenic SEs promote tumorigenesis and malignancy by altering protein-coding gene expression and noncoding regulatory element function. Therefore, they play central roles in the treatment of cancer. Here, we review the structural characteristics, organization, identification, and functions of SEs and the underlying molecular mechanism by which SEs drive oncogenic transcription in tumor cells. We then summarize abnormal SE complexes, SE-driven coding genes, and noncoding RNAs involved in tumor development. In summary, we believe that SEs show great potential as biomarkers and therapeutic targets.

Disruption of RCAN1.4 expression mediated by YY1/HDAC2 modulates chronic renal allograft interstitial fibrosis

Chronic allograft dysfunction (CAD) is a major factor that hinders kidney transplant survival in the long run. Epithelial-mesenchymal transition (EMT) has been confirmed to significantly contribute to interstitial fibrosis/tubular atrophy (IF/TA), which is the main histopathological feature of CAD. Aberrant expression of the regulator of calcineurin 1 (RCAN1), recognized as an endogenous inhibitor of the calcineurin phosphatase, has been shown to be extensively involved in various kidney diseases. However, it remains unclear how RCAN1.4 regulates IF/TA formation in CAD patients. Herein, an in vivo mouse renal transplantation model and an in vitro model of human renal tubular epithelial cells (HK-2) treated with tumor necrosis factor-α (TNF-α) were employed. Our results proved that RCAN1.4 expression was decreased in vivo and in vitro, in addition to the up-regulation of Yin Yang 1 (YY1), a transcription factor that has been reported to convey multiple functions in chronic kidney disease (CKD). Knocking in of RCAN1.4 efficiently attenuated chronic renal allograft interstitial fibrosis in vivo and inhibited TNF-α-induced EMT in vitro through regulating anti-oxidative stress and the calcineurin/nuclear factor of activated T cells cytoplasmic 1 (NFATc1) signaling pathway. In addition, suppression of YY1 mediated by shRNA or siRNA alleviated TNF-α-induced EMT through abolishing reactive species partly in an RCAN1.4-dependent manner. Notably, we confirmed that YY1 negatively regulated RCAN1.4 transcription by directly interacting with the RCAN1.4 promoter. In addition, histone deacetylase 2 (HDAC2) interacted with YY1 to form a multi-molecular complex, which was involved in TNF-α-induced RCAN1.4 transcriptional repression. Therefore, RCAN1.4 is suggested to be modulated by the YY1/HDAC2 transcription repressor complex in an epigenetic manner, which is a mediated nephroprotective effect partly through modulating O2⋅- generation and the calcineurin/NFATc1 signaling pathway. Thus, the YY1-RCAN1.4 axis constitutes an innovative target for IF/TA treatment in CAD patients.

A novel implant surface modification mode of Fe3O4-containing TiO2 nanorods with sinusoidal electromagnetic field for osteoblastogenesis and angiogenesis

Implants made of Ti and its alloys are widely utilized in orthopaedic surgeries. However, insufficient osseointegration of the implants often causes complications such as aseptic loosening. Our previous research discovered that disordered titanium dioxide nanorods (TNrs) had satisfactory antibacterial properties and biocompatibility, but TNrs harmed angiogenic differentiation, which might retarded the osseointegration process of the implants. Magnetic nanomaterials have a certain potential in promoting osseointegration, electromagnetic fields within a specific frequency and intensity range can facilitate angiogenic and osteogenic differentiation. Therefore, this study used Fe₃O₄ to endow magnetism to TNrs and explored the regulation effects of Ti, TNrs, and Fe₃O₄-TNrs under 1 ​mT 15 ​Hz sinusoidal electromagnetic field (SEMF) on osteoblastogenesis, osseointegration, angiogenesis, and its mechanism. We discovered that after the addition of SEMF treatment to VR-EPCs cultured on Fe₃O₄-TNrs, the calcineurin/NFAT signaling pathway was activated, which then reversed the inhibitory effect of Fe₃O₄-TNrs on angiogenesis. Besides, Fe₃O₄-TNrs with SEMF enhanced osteogenic differentiation and osseointegration. Therefore, the implant modification mode of Fe₃O₄-TNrs with the addition of SEMF could more comprehensively promote osseointegration and provided a new idea for the modification of implants.

Inverse Comorbidity between Down Syndrome and Solid Tumors: Insights from In Silico Analyses of Down Syndrome Critical Region Genes

An inverse comorbidity has been observed between Down syndrome (DS) and solid tumors such as breast and lung cancers, and it is posited that the overexpression of genes within the Down Syndrome Critical Region (DSCR) of human chromosome 21 may account for this phenomenon. By analyzing publicly available DS mouse model transcriptomics data, we aimed to identify DSCR genes that may protect against human breast and lung cancers. Gene expression analyses with GEPIA2 and UALCAN showed that DSCR genes ETS2 and RCAN1 are significantly downregulated in breast and lung cancers, and their expression levels are higher in triple-negative compared to luminal and HER2-positive breast cancers. KM Plotter showed that low levels of ETS2 and RCAN1 are associated with poor survival outcomes in breast and lung cancers. Correlation analyses using OncoDB revealed that both genes are positively correlated in breast and lung cancers, suggesting that they are co-expressed and perhaps have complementary functions. Functional enrichment analyses using LinkedOmics also demonstrated that ETS2 and RCAN1 expression correlates with T-cell receptor signaling, regulation of immunological synapses, TGF-β signaling, EGFR signaling, IFN-γ signaling, TNF signaling, angiogenesis, and the p53 pathway. Altogether, ETS2 and RCAN1 may be essential for the development of breast and lung cancers. Experimental validation of their biological functions may further unravel their roles in DS and breast and lung cancers.

Integrated analysis of transcriptomics and metabolomics in human hepatocellular carcinoma HepG2215 cells after YAP1 knockdown

Yes-associated protein 1 (YAP1) plays a critical role in hepatocellular carcinoma (HCC). Inhibition of YAP1 expression suppresses HCC progression, but the underlying mechanism is still unclear. In this study, we studied the effects and molecular mechanisms of YAP1 knockdown on the growth and metabolism in human HCC HepG2215 cells. Inhibition of YAP1 expression inhibits the proliferation and metastasis in HepG2215 cells, and differentially expressed genes (DEGs) and metabolites were identified in shYAP1-HepG2215 cells. Further, 805 DEGs, mainly associated with metabolism and particularly lipid metabolism, were identified by transcriptome sequencing analyses in shYAP1-HepG2215 cells. YAP1 knockdown increased albumin (ALB) levels by Protein-protein interaction (PPI) network analyses in HepG2215 cells. Metabolomic profiling identified 37 metabolites with significant differences in the shYAP1 group, and amino acid metabolism generally decreased in the shYAP1 group. Comprehensive analysis of transcriptomics and metabolomics revealed that the ATP-binding cassette (ABC) transporters play a central role after YAP1 knockdown in HepG2215 cells. Therefore, YAP1 knockdown inhibited HCC growth, which affected the metabolism of lipids and amino acids by regulating the expression of ALB and ABC transporters in HepG2215 cells.

Roles of calcium signaling in cancer metastasis to bone

Bone metastasis is a frequent complication for cancers and an important reason for the mortality in cancer patients. After surviving in bone, cancer cells can cause severe pain, life-threatening hypercalcemia, pathologic fractures, spinal cord compression, and even death. However, the underlying mechanisms of bone metastasis were not clear. The role of calcium (Ca2+) in cancer cell proliferation, migration, and invasion has been well established. Interestingly, emerging evidence indicates that Ca2+ signaling played a key role in bone metastasis, for it not only promotes cancer progression but also mediates osteoclasts and osteoblasts differentiation. Therefore, Ca2+ signaling has emerged as a novel therapeutical target for cancer bone metastasis treatments. Here, the role of Ca2+ channels and Ca2+-binding proteins including calmodulin and Ca2+-sensing receptor in bone metastasis, and the perspective of anti-cancer bone metastasis therapeutics via targeting the Ca2+ signaling pathway are summarized.

YES1 is a druggable oncogenic target in Small Cell Lung Cancer

RATIONALE

Small cell lung cancer (SCLC) is an extremely aggressive subtype of lung cancer without approved targeted therapies. Here we identified YES1 as a novel targetable oncogene driving SCLC maintenance and metastasis.

OBJECTIVES

To investigate the role of YES1 in SCLC prognosis and evaluate its inhibition as a new therapeutic strategy.

METHODS

Association between YES1 levels and prognosis was evaluated in SCLC clinical samples. In vitro functional experiments for proliferation, apoptosis, cell cycle and cytotoxicity were performed. Genetic and pharmacological inhibition of YES1 was evaluated in vivo in cell-/patient-derived xenografts (PDXs) and in metastasis. YES1 levels were evaluated in mouse and patients' plasma-derived exosomes MEASUREMENTS AND MAIN RESULTS: Overexpression or gain/amplification of YES1 was identified in 31% and 26% of cases, respectively, across molecular subgroups, and was found as an independent predictor of poor prognosis. Genetic depletion of YES1 dramatically reduced cell proliferation, 3D organoid formation, tumor growth and distant metastasis, leading to extensive apoptosis and tumor regressions. Mechanistically, YES1-inhibited cells showed alterations in the replisome and DNA repair processes, that conferred sensitivity to irradiation. Pharmacological blockade with the novel YES1 inhibitor CH6953755 or Dasatinib induced significant anti-tumor activity in organoid models and cell-/patient-derived xenografts. YES1 protein was detected in plasma exosomes from patients and mouse models, with levels matching those of tumors, suggesting that circulating YES1 could represent a biomarker for patient selection/monitoring.

CONCLUSIONS

Our results provide evidence that YES1 is a new druggable oncogenic target and biomarker to advance the clinical management of a subpopulation of SCLC patients.

RNA splicing: a dual-edged sword for hepatocellular carcinoma

RNA splicing is the fundamental process that brings diversity at the transcriptome and proteome levels. The spliceosome complex regulates minor and major processes of RNA splicing. Aberrant regulation is often associated with different diseases, including diabetes, stroke, hypertension, and cancer. In the majority of cancers, dysregulated alternative RNA splicing (ARS) events directly affect tumor progression, invasiveness, and often lead to poor survival of the patients. Alike the rest of the gastrointestinal malignancies, in hepatocellular carcinoma (HCC), which alone contributes to ~ 75% of the liver cancers, a large number of ARS events have been observed, including intron retention, exon skipping, presence of alternative 3'-splice site (3'SS), and alternative 5'-splice site (5'SS). These events are reported in spliceosome and non-spliceosome complexes genes. Molecules such as MCL1, Bcl-X, and BCL2 in different isoforms can behave as anti-apoptotic or pro-apoptotic, making the spliceosome complex a dual-edged sword. The anti-apoptotic isoforms of such molecules bring in resistance to chemotherapy or cornerstone drugs. However, in contrast, multiple malignant tumors, including HCC that target the pro-apoptotic favoring isoforms/variants favor apoptotic induction and make chemotherapy effective. Herein, we discuss different splicing events, aberrations, and antisense oligonucleotides (ASOs) in modulating RNA splicing in HCC tumorigenesis with a possible therapeutic outcome.

Upregulation of RCAN1.4 by HIF1α alleviates OGD-induced inflammatory response in astrocytes

OBJECTIVE

Ischemic stroke is a leading cause of human mortality and long-term disability worldwide. As one of the main forms of regulator of calcineurin 1 (RCAN1), the contribution of RCAN1.4 in diverse biological and pathological conditions has been implicated. But the role of RCAN1.4 in ischemic stroke progression remains elusive. This study is to explore the expression changes and roles of RCAN1.4 in ischemic stroke as well as the underlying mechanisms for these changes and effects of RCAN1.4 in ischemic stroke.

METHODS

Middle cerebral artery occlusion model in C57BL/6J mice and oxygen-glucose deprivation (OGD) model in primary astrocytes were performed to induce the cerebral ischemic stroke. The expression pattern of RCAN1.4 was assessed using real-time quantitative PCR and western blotting in vivo and in vitro. Mechanistically, the underlying mechanism for the elevation of RCAN1.4 in the upstream was investigated. Lentiviruses were administrated, and the effect of RCAN1.4 in postischemic inflammation was clearly clarified.

RESULTS

Here we uncovered that RCAN1.4 was dramatically increased in mouse ischemic brains and OGD-induced primary astrocytes. HIF1α, activated upon OGD, significantly upregulated RCAN1.4 gene expression through specifically binding to the RCAN1.4 promoter region and activating its promoter activity. The functional hypoxia-responsive element (HRE) was located between -254 and -245 bp in the RCAN1.4 promoter region. Moreover, elevated RCAN1.4 alleviated the release of pro-inflammatory cytokines TNFα, IL1β, IL6 and reduced expression of iNOS, COX2 in primary astrocytes upon OGD, whereas RCAN1.4 silencing has the opposite effect. Of note, RCAN1.4 overexpression inhibited OGD-induced NF-κB activation in primary astrocytes, leading to decreased degradation of IκBα and reduced nuclear translocation of NF-κB/p65.

INTERPRETATION

Our results reveal a novel mechanism underscoring the upregulation of RCAN1.4 by HIF1α and the protective effect of RCAN1.4 against postischemic inflammation, suggesting its significance as a promising therapeutic target for ischemic stroke treatment.

RCAN1-mediated calcineurin inhibition as a target for cancer therapy

Cancer is the leading cause of mortality worldwide. Regulator of calcineurin 1 (RCAN1), as a patent endogenous inhibitor of calcineurin, plays crucial roles in the pathogenesis of cancers. Except for hypopharyngeal and laryngopharynx cancer, high expression of RCAN1 inhibits tumor progression. Molecular antitumor functions of RCAN1 are largely dependent on calcineurin. In this review, we highlight current research on RCAN1 characteristics, and the interaction between RCAN1 and calcineurin. Moreover, the dysregulation of RCAN1 in various cancers is reviewed, and the potential of targeting RCAN1 as a new therapeutic approach is discussed.

Down-regulation of circPTTG1IP induces hepatocellular carcinoma development via miR-16-5p/RNF125/JAK1 axis

Circular RNAs are known to regulate the biological processes of hepatocellular carcinoma (HCC), and humans with Down syndrome are at low risk of developing solid tumors due to the amplification of several tumor suppressor genes on human chromosome 21 (HSA21). Here, we aimed to investigate the potential role of circRNAs originating from HSA21 in the progression of HCC. CircRNA-sequencing was performed to analyze differentially expressed circRNAs in 4 HCC and peritumor tissues, and circRNAs originating from HSA21 were further analyzed. Circ_0061984 (circPTTG1IP) was chosen for further study because it showed the lowest expression in HCC tissues, and qRT-PCR was used to confirm the expression of circPTTG1IP in HCC patient tissues. The biological function of circPTTG1IP was detected in HCC cells both in vivo and in vitro. Moreover, luciferase reporter assays, circRNA immunoprecipitation, and fluorescence in situ hybridization (FISH) were used to investigate the potential mechanism of circPTTG1IP. Finally, the possible mechanisms of filgotinib in circPTTG1IP-driven HCC were assessed. CircPTTG1IP expression was decreased in HCC compared to peritumoral tissues. Moreover, low circPTTG1IP expression was revealed to be associated with a poor prognosis of HCC patients. Elevation of circPTTG1IP was revealed to inhibit HCC development both in vitro and in vivo. Mechanistically, circPTTG1IP was shown to function as a competing endogenous RNA (ceRNA) of RNF125 by binding miR-16-5p to increase the level of the E3 ubiquitin ligase RNF125, which further ubiquitinated and degraded JAK1 protein. Finally, we demonstrated that administration of filgotinib, a JAK1 inhibitor, restricted HCC progression induced by low circPTTG1IP expression. Thus, we revealed that circPTTG1IP is a novel tumor suppresser circRNA in HCC and that a low circPTTG1IP level promotes HCC development via the miR-16-5p/RNF125/JAK1 axis. Patients with low circPTTG1IP may benefit from filgotinib treatment.

An Alternatively Spliced Variant of METTL3 Mediates Tumor Suppression in Hepatocellular Carcinoma

Many post-transcriptional mRNA processing steps play crucial roles in tumorigenesis and the progression of cancers, such as N6-methyladenosine (m⁶A) modification and alternative splicing. Upregulation of methyltransferase-like 3 (METTL3), the catalytic core of the m⁶A methyltransferase complex, increases m⁶A levels and results in significant effects on the progression of hepatocellular carcinoma (HCC). However, alternative splicing of METTL3 has not been fully investigated, and the functions of its splice variants remain unclear. Here, we analyzed both our and online transcriptomic data, obtaining 13 splice variants of METTL3 in addition to canonical full-length METTL3-A in HCC cell lines and tissues. Validated by RT–qPCR and Western blotting, we found that METTL3-D, one of the splice variants expressing a truncated METTL3 protein, exhibits higher levels than METTL3-A in normal human livers but lower levels than METTL3-A in HCC tumor tissues and cell lines. Further functional assays demonstrated that METTL3-D expression decreased cellular m⁶A modification, inhibited the proliferation, migration, and invasion of HCC cells, and was negatively associated with the malignancy of patient tumors, exhibiting functions opposite to those of full-length METTL3-A. This study demonstrates that the METTL3-D splice variant is a tumor suppressor that could potentially be used as a target for HCC therapy.

Nomograms Incorporating the CNLC Staging System Predict the Outcome of Hepatocellular Carcinoma After Curative Resection

Purpose

Prediction models of postoperative outcomes of patients with hepatocellular carcinoma (HCC) after surgery based on the China liver cancer (CNLC) staging system are rare. This study aimed to compare the prognostic abilities of CNLC, Tumor-Node-Metastasis (TNM) 8th edition, and Barcelona Clinic Liver Cancer (BCLC) staging systems for HCC after curative resection. We developed two nomograms incorporating the CNLC staging system to predict the postoperative recurrence-free survival (RFS) and overall survival (OS) of HCC patients.

Patients and methods

The prognostic abilities of the CNLC, TNM and BCLC staging systems for HCC after curative resection were compared using receiver operating characteristic (ROC) curves. Two nomograms incorporating five selected risk factors were constructed based on multivariate Cox regression in the primary cohort of 312 HCC patients. It was validated with an independent validation cohort of 130 HCC patients. The predictive performance and discrimination ability of the two nomograms were further evaluated and compared with those of the TNM and BCLC staging systems.

Results

The CNLC staging system had a higher area under the receiver operating characteristic curve (AUROC) value for both OS (AUC=0.692) and RFS (AUC=0.673) than the TNM (ROC=0.667 for OS and 0.652 for RFS) and BCLC (ROC=0.671 for OS and 0.670 for RFS) staging systems. The independent predictors of OS (cirrhosis, gamma-glutamyl transpeptidase (GGT), tumor differentiation and CNLC staging system) and RFS (α-fetoprotein (AFP) and CNLC staging system) were incorporated into the two nomograms. The OS and RFS nomograms consistently outperformed the TNM and BCLC staging systems in the primary cohort. These results were verified in the validation cohort. In the 442 patients with HCC, the RFS nomogram could predict early recurrence very well.

Conclusion

The two proposed nomograms incorporating the CNLC staging system can predict the outcomes of patients with HCC after curative hepatectomy in clinical practice.

RCAN1.4 attenuates renal fibrosis through inhibiting calcineurin-mediated nuclear translocation of NFAT2

Chronic kidney disease (CKD) is thus deemed to a global health problem. Renal fibrosis, characterized by accumulation of extracellular matrix (ECM) components in the kidney, is considered a common pathway leading to CKD. Regulator of calcineurin1 (RCAN1), identified as a competitive endogenous inhibitor of the phosphatase calcineurin, participates in ECM deposition in various organs. However, the role of RCAN1 in renal fibrosis remains unclear. Here, unilateral ureteral obstruction (UUO), a well-known model to induce renal fibrosis in vivo, was performed on mice for a week. To overexpress RCAN1.4 in vivo, recombinant adeno-associated virus 9-packed RCAN1.4 over-expression plasm was employed in mice kidney. Lentivirus-packed RCAN1.4 over-expression plasm was employed to transfer into HK-2 and NRK-49F cells in vitro. The results indicated that RCAN1.4 expression was impaired both in UUO-induced renal fibrosis in vivo and TGF-β1-induced renal fibrosis in vitro. However, knocking in of RCAN1.4 suppressed the production of extracellular matrix (ECM) both in vivo and in vitro. Furthermore, in vitro, the apoptosis-related proteins, including the ratio of Bax/Bcl-2 and cleaved-caspase3, were elevated in cells transfected with RCAN1.4 overexpression plasmid. In addition, we found that RCAN1.4 could rugulated NFAT2 nuclear distribution by inhibiting calcineurin pathway. So overexpression of RCAN1.4 could reverse renal fibrosis, attenuate ECM related protein accumulation, promote apoptosis of myofibroblast via inhibiting Calcineurin/NFAT2 signaling pathway. Taken together, our study demonstrated that targeting RCAN1.4 may be therapeutic efficacy in renal fibrosis.

The Immunology of Hepatocellular Carcinoma

Liver cancer is the third leading cause of cancer death worldwide. Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver. Liver resection or transplantation offer the only potentially curative options for HCC; however, many patients are not candidates for surgical resection, either due to presentation at advanced stages or poor liver function and portal hypertension. Liver transplantation is also limited to patients with certain characteristics, such as those that meet the Milan criteria (one tumor ≤ 5 cm, or up to three tumors no larger than 3 cm, along with the absence of gross vascular invasion or extrahepatic spread). Locoregional therapies, such as ablation (radiofrequency, ethanol, cryoablation, microwave), trans-arterial therapies like chemoembolization (TACE) or radioembolization (TARE), and external beam radiation therapy, have been used mainly as palliative measures with poor prognosis. Therefore, emerging novel systemic treatments, such as immunotherapy, have increasingly become popular. HCC is immunogenic, containing infiltrating tumor-specific T-cell lymphocytes and other immune cells. Immunotherapy may provide a more effective and discriminatory targeting of tumor cells through induction of a tumor-specific immune response in cancer cells and can improve post-surgical recurrence-free survival in HCC. We herein review evidence supporting different immunomodulating cell-based technology relative to cancer therapy in vaccines and targeted therapies, such as immune checkpoint inhibitors, in the management of hepatocellular carcinoma among patients with advanced disease.

RNA binding protein serine/arginine splicing factor 1 promotes the proliferation, migration and invasion of hepatocellular carcinoma by interacting with RecQ protein-like 4 mRNA

Abnormally high expression of RecQ protein-like 4 (RECQL4) has been observed in many cancers, including hepatocellular carcinoma (HCC). We aimed to explore the effects of RECQL4 on HCC progression and the possible mechanisms. RECQL4 expression in HCC tissues and its correlation with the prognosis of HCC patients were analyzed using GEPIA2 and UALCAN databases. After detecting RECQL4 levels in several human HC cell lines, RECQL4 was silenced by siRNA transfection. Cell viability, migration and invasion were tested with CCK-8, wound healing and transwell assays. The levels of epithelial–mesenchymal transition (EMT) proteins were evaluated by western blotting. The ENCORI database was adopted for the analysis of the correlation between RECQL4 and serine/arginine splicing factor 1 (SRSF1) in HCC tissues. RNA immunoprecipitation and actinomycin D addition assay were employed to evaluate the combination of these two genes. SRSF1 was overexpressed to assess the biological function of HCC cells with RECQL4 silencing. Results suggested that RECQL4 was overexpressed in HCC tissues and cell lines, which was related to poor prognosis of HCC patients. RECQL4 loss-of-function repressed the proliferation, migration, invasion and EMT of HCC cells. RECQL4 was positively correlated with SRSF1 in HCC tissues. Moreover, SRSF1 was confirmed as an RNA binding protein of RECQL4. Further experiments found that SRSF1 knockdown reduced the stability of RECQL4 mRNA. Rescue assays indicated that SRSF1 overexpression crippled the braking effects of RECQL4 knockdown on the progression of HCC cells. Collectively, SRSF1 can bind to RECQL4 mRNA and enhance its stability, thereby promoting the progression of HCC.

Calcium signaling in cancer progression and therapy

The old Greek aphorism 'Panta Rhei' ('everything flows') is true for all living things in general. As a dynamic process, calcium signaling plays fundamental roles in cellular activities under both normal and pathological conditions, with recent researches uncovering its involvement in cell proliferation, migration, survival, gene expression, and more. The major question we address here is how calcium signaling affects cancer progression and whether it could be targeted to combine with classic chemotherapeutics or emerging immunotherapies to improve their efficacy.

RCAN1.4 suppresses the osteosarcoma growth and metastasis via interfering with the calcineurin/NFAT signaling pathway

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Protein level of RCAN1.4 in osteosarcoma specimens was lower than that of chondroma.

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RCAN1.4 loss promoted osteosarcoma growth, migration and invasion.

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RCAN1.4-calcineurin/NFAT pathway regulated the osteosarcoma growth and metastasis.

Calcipressin-1, also known as a regulator of calcineurin 1 (RCAN1), is one of the families of endogenous regulators of calcineurin activation and can specifically constrain the activity of calcineurin, but its function in osteosarcoma is still unknown. Firstly, we examined the protein level of RCAN1 in osteosarcoma specimens was lower than that of chondroma specimens. RCAN1.4 rather than RCAN1.1 had a higher endogenous protein level in six osteosarcoma cell lines by western blot. Further, we created stable RCAN1.4-deficient 143B and Hos cells using CRISPR-Cas9. RCAN1.4 loss promoted tumor growth in subcutaneous xenograft models. RCAN1.4 knockdown promoted tumor metastases to the lungs using intravenous metastasis models. Furthermore, we found that higher activity of calcineurin in RCAN1.4-deficient cells enhanced the nuclear translocation of NFATc1 to induce the cyclin D1 and MMPs expression. In addition, RCAN1.4 overexpression restrained osteosarcoma cell growth and invasion and inhibited the activity of calcineurin. Finally, we discovered that conditioned medium (20%) derived from RCAN1.4-deficient cells significantly promoted osteoclastogenesis, indicating Receptor Activator of Nuclear factor κB (RANK) signaling activation during osteosarcoma metastasis. In conclusion, RCAN1.4 may be a potential therapeutic target for osteosarcoma.

EGFR activation limits the response of liver cancer to lenvatinib

Hepatocellular carcinoma (HCC)-the most common form of liver cancer-is an aggressive malignancy with few effective treatment options¹. Lenvatinib is a small-molecule inhibitor of multiple receptor tyrosine kinases that is used for the treatment of patients with advanced HCC, but this drug has only limited clinical benefit². Here, using a kinome-centred CRISPR-Cas9 genetic screen, we show that inhibition of epidermal growth factor receptor (EGFR) is synthetic lethal with lenvatinib in liver cancer. The combination of the EGFR inhibitor gefitinib and lenvatinib displays potent anti-proliferative effects in vitro in liver cancer cell lines that express EGFR and in vivo in xenografted liver cancer cell lines, immunocompetent mouse models and patient-derived HCC tumours in mice. Mechanistically, inhibition of fibroblast growth factor receptor (FGFR)  by lenvatinib treatment leads to feedback activation of the EGFR-PAK2-ERK5 signalling axis, which is blocked by EGFR inhibition. Treatment of 12 patients with advanced HCC who were unresponsive to lenvatinib treatment with the combination of lenvatinib plus gefitinib (trial identifier NCT04642547) resulted in meaningful clinical responses. The combination therapy identified here may represent a promising strategy for the approximately 50% of patients with advanced HCC who have high levels of EGFR.

Development and validation of a risk prediction model and nomogram for colon adenocarcinoma based on methylation-driven genes

Evidence suggests that abnormal DNA methylation patterns play a crucial role in the etiology and pathogenesis of colon adenocarcinoma (COAD). In this study, we identified a total of 97 methylation-driven genes (MDGs) through a comprehensive analysis of the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Univariate Cox regression analysis identified four MDGs (CBLN2, RBM47, SLCO4C1, and TMEM220) associated with overall survival (OS) in COAD patients. A risk prediction model was then developed based on these four MDGs to predict the prognosis of COAD patients. We also created a nomogram that incorporated risk scores, age, and TNM stage to promote a personalized prediction of OS in COAD patients. Compared with the traditional TNM staging system, our new nomogram was better at predicting the OS of COAD patients. In cell experiments, we confirmed that the mRNA expression levels of CLBN2 and TMEM220 were regulated by the methylation of their promoter regions. Moreover, immunohistochemistry showed that CBLN2 and TMEM220 were potential prognostic biomarkers for COAD patients. In summary, we have established a risk prediction model and nomogram that might be effectively utilized to promote the prediction of OS in COAD patients.

mir-182-5p Regulates Cell Growth of Liver Cancer via Targeting RCAN1

Regulator of calcineurin 1 (RCAN1) is an endogenous protein that is involved in the regulation of the occurrence and progression of a variety of cancers, but currently, people know little about its potential mechanism. This study investigated the function and mechanism of RCAN1 and miR-182-5p in liver cancer cells. In this study, reliable data demonstrated that RCAN1 suppressed cell proliferation, migration, invasion, and cell cycle progression of liver cancer. Additionally, the expression of RCAN1 was noted to be regulated by its upstream regulator miR-182-5p, and miR-182-5p was prominently highly expressed in liver cancer cells. Based on this, it was further proved through cell experiments that miR-182-5p facilitated cell growth of liver cancer through RCAN1 downregulation, showing that RCAN1 may be a fresh biomarker and target for diagnosis and treatment of liver cancer.

Overexpression of DSCR1 prevents proliferation and predicts favorable prognosis in colorectal cancer patients

Objectives

Down syndrome critical region 1 (DSCR1) is associated with carcinogenesis and tumor growth in several types of malignancy. However, little is known about the role of DSCR1 in CRC progression. The present study aimed to elucidate the clinicopathological significance, prognostic, and function roles of DSCR1 in CRC.

Methods

Firstly, we analyzed DSCR1 expression in 58 paired CRC samples and Oncomine database. Then, we analyzed DSCR1 expression in two independent CRC cohorts (test cohort: n = 70; validation cohort: n = 58) and tested its overall survival (OS) by Kaplan-Meier survival analyses. Finally, we overexpressed DSCR1 in two CRC cell lines DLD1 and LoVo and analyzed its effect on cell cycle and senescence.

Results

DSCR1 expression was significantly decreased in CRC samples and associated with clinicopathologic features of CRC patients, such as tumor size, lymph node metastasis, and TNM stage. CRC patients with low expression of DSCR1 had shorter overall survival (OS). Kaplan-Meier survival analyses showed that the expression of DSCR1 was significant factor for OS in both cohorts. Multiple Cox regression analysis showed that DSCR1 expression was an independent prognostic marker for OS in test cohort. Overexpression of DSCR1 isoform 4 (DSCR1-4) increased p21, p16, p-NFAT1, and p-NFAT2, while decreased CDK2, CDK4, and Cyclin D1 in CRC cells. In addition, overexpression of DSCR1-4 prevented proliferation and colony formation, and induced senescence in vitro. Moreover, overexpression of DSCR1-4 inhibited tumor growth and tumor angiogenesis in vivo.

Conclusions

Our study found high expression of DSCR1 contributes to favorable prognosis of CRC patients and prevents cell cycle and proliferation of CRC cells, indicating a critical tumor suppressive role in CRC progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02212-7.

Regulator of calcineurin 1 gene isoform 4 in pancreatic ductal adenocarcinoma regulates the progression of tumor cells

Therapeutic strategies to treat pancreatic ductal adenocarcinoma (PDAC) remain unsatisfying and limited. Therefore, it is imperative to fully determine the mechanisms underlying PDAC progression. In the present study, we report a novel role of regulator of calcineurin 1, isoform 4 (RCAN1.4) in regulating PDAC progression. We demonstrated that RCAN1.4 expression was decreased significantly in PDAC tissues compared with that in para-cancerous tissues, and correlated with poor prognosis of patients with pancreatic cancer. In vitro, stable high expression of RCAN1.4 could suppress the metastasis and proliferation and angiogenesis of pancreatic tumor cells. In addition, interferon alpha inducible protein 27 (IFI27) was identified as having a functional role in RCAN1.4-mediated PDAC migration and invasion, while VEGFA play a vital role in RCAN1.4-mediated PDAC angiogenesis. Analysis of mice with subcutaneously/orthotopic implanted xenograft tumors and liver metastasis model confirmed that RCAN1.4 could modulate the growth, metastasis, and angiogenesis of tumors via IFI27/VEGFA in vivo. In conclusion, our results suggested that RCAN1.4 suppresses the growth, metastasis, and angiogenesis of PDAC, functioning partly via IFI27 and VEGFA. Importantly, our results provided possible diagnostic criteria and therapeutic targets for PDAC.

Glutamate receptor ionotropic, kainate 1 serves as a novel tumor suppressor of colorectal carcinoma and predicts clinical prognosis

Colorectal cancer (CRC) is one of the most malignant cancers worldwide. However, the mechanisms of initiation and development of CRC are still largely unclear. The present study aimed to investigate the biological function and prognosis of glutamate receptor ionotropic, kainate 1 (GRIK1) in CRC. GRIK1 expression levels were analyzed in tissue microarrays containing 80 primary CRC samples using immunohistochemistry (IHC). The association between GRIK1 expression levels, clinicopathological factors and the prognosis was also investigated using Spearman's correlation analysis and Kaplan-Meier analysis, respectively. After genetic knockdown or overexpression of GRIK1, invasion/migration assays, proliferation assay, soft agar/colony formation assays, western blotting, reverse transcription-quantitative PCR and tumor xenograft models were used to investigate the function of GRIK1 both in vitro in two CRC cell lines, HCT116 and SW620, and in vivo. The results revealed that the expression levels of GRIK1 were significantly downregulated in CRC samples. Furthermore, IHC analysis indicated that the downregulated expression levels of GRIK1 were significantly associated with lymph node status and tumor size. In addition, patients with CRC with low GRIK1 expression levels demonstrated a consistently poor overall survival. The overexpression of GRIK1 inhibited the proliferation, colony formation, migration, invasion and epithelial-mesenchymal transition of HCT116 cells in vitro. In contrast, the genetic knockdown of GRIK1 promoted the proliferative, colony forming, migratory and invasive abilities of SW620 cells in vitro. Moreover, the overexpression of GRIK1 inhibited tumor growth, and liver and lung metastasis of CRC in vivo. In conclusion, the findings of the present study suggested that GRIK1 may serve as a tumor suppressor in CRC, and upregulated expression levels of GRIK1 may predict an improved prognosis for patients with CRC.

A powerful drug combination strategy targeting glutamine addiction for the treatment of human liver cancer

The dependency of cancer cells on glutamine may be exploited therapeutically as a new strategy for treating cancers that lack druggable driver genes. Here we found that human liver cancer was dependent on extracellular glutamine. However, targeting glutamine addiction using the glutaminase inhibitor CB-839 as monotherapy had a very limited anticancer effect, even against the most glutamine addicted human liver cancer cells. Using a chemical library, we identified V-9302, a novel inhibitor of glutamine transporter ASCT2, as sensitizing glutamine dependent (GD) cells to CB-839 treatment. Mechanically, a combination of CB-839 and V-9302 depleted glutathione and induced reactive oxygen species (ROS), resulting in apoptosis of GD cells. Moreover, this combination also showed tumor inhibition in HCC xenograft mouse models in vivo. Our findings indicate that dual inhibition of glutamine metabolism by targeting both glutaminase and glutamine transporter ASCT2 represents a potential novel treatment strategy for glutamine addicted liver cancers.

Study on the hepatocellular carcinoma model with metastasis

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related death around the world due to advanced clinical stage at diagnosis, high incidence of recurrence and metastasis after surgical treatment. It is in urgent need to create appropriate animal models to explore the mechanism, patterns, risk factors, and therapeutic strategies of HCC metastasis and recurrence. However, most of the established models lack the phenotype of invasion and metastasis in patient, or have unstable phenotype. To establish HCC models with stable metastasis phenotype requires profound understanding in cancer metastasis biology and scientific methodology. Over the past 3 decades, HCC models with stable metastasis have been extensively studied. This paper reviewed the history and development of HCC animal models and cell models, focusing on the screening and maintaining of metastatic potential and phenotype. In-depth studies using these models vastly promote the understanding of cellular and molecular mechanisms and development of therapeutic strategies on HCC metastasis.

Disruption of super-enhancer-driven tumor suppressor gene RCAN1.4 expression promotes the malignancy of breast carcinoma

Background

Super-enhancers (SEs) play a crucial role in cancer, which is often associate with activated oncogenes. However, little is known about how SEs facilitate tumour suppression. Individuals with Down syndrome exhibit a remarkably reduced incidence of breast cancer (BC), moving the search for tumor suppressor genes on human chromosome 21 (HSA21). In this study, we aim to identify and explore potential mechanisms by which SEs are established for tumor suppressor RCAN1.4 on HSA21 in BC.

Methods

In silico analysis and immunohistochemical staining were used to assess the expression and clinical relevance of RCAN1.4 and RUNX3 in BC. Function experiments were performed to evaluate the effects of RCAN1.4 on the malignancy of breast carcinoma in vitro and in vivo. ChIP-seq data analysis, ChIP-qPCR, double-CRISPR genome editing, and luciferase reporter assay were utilized to confirm RUNX3 was involved in regulating RCAN1.4-associated SE in BC. The clinical value of co-expression of RCAN1.4 and RUNX3 was evaluated in BC patients.

Results

Here, we characterized RCAN1.4 as a potential tumour suppressor in BC. RCAN1.4 loss promoted tumour metastasis to bone and brain, and its overexpression inhibited tumour growth by blocking the calcineurin-NFATc1 pathway. Unexpectedly, we found RCAN1.4 expression was driven by a ~ 23 kb-long SE. RCAN1.4-SE^distal was sensitive to BRD4 inhibition, and its deletion decreased RCAN1.4 expression by over 90% and induced the malignant phenotype of BC cells. We also discovered that the binding sites in the SE region of RCAN1.4 were enriched for consensus sequences of transcription factor RUNX3. Knockdown of RUNX3 repressed the luciferase activity and also decreased H3K27ac enrichment binding at the SE region of RCAN1.4. Furthermore, abnormal SE-driven RCAN1.4 expression mediated by RUNX3 loss could be physiologically significant and clinically relevant in BC patients. Notably, we established a prognostic model based on RCAN1.4 and RUNX3 co-expression that effectively predicted the overall survival in BC patients.

Conclusions

These findings reveal an important role of SEs in facilitating tumour suppression in BC. Considering that the combination of low RCAN1.4 and low RUNX3 expression has worse prognosis, RUNX3-RCAN1.4 axis maybe a novel prognostic biomarker and therapeutic target for BC patients.

COL4A1 promotes the growth and metastasis of hepatocellular carcinoma cells by activating FAK-Src signaling

BACKGROUND

Collagens are the most abundant proteins in extra cellular matrix and important components of tumor microenvironment. Recent studies have showed that aberrant expression of collagens can influence tumor cell behaviors. However, their roles in hepatocellular carcinoma (HCC) are poorly understood.

METHODS

In this study, we screened all 44 collagen members in HCC using whole transcriptome sequencing data from the public datasets, and collagen type IV alpha1 chain (COL4A1) was identified as most significantly differential expressed gene. Expression of COL4A1 was detected in HCC samples by quantitative real-time polymerase chain reaction (qRT-PCR), western blot and immunohistochemistry (IHC). Finally, functions and potential mechanisms of COL4A1 were explored in HCC progression.

RESULTS

COL4A1 is the most significantly overexpressed collagen gene in HCC. Upregulation of COL4A1 facilitates the proliferation, migration and invasion of HCC cells through FAK-Src signaling. Expression of COL4A1 is upregulated by RUNX1 in HCC. HCC cells with high COL4A1 expression are sensitive to the treatment with FAK or Src inhibitor.

CONCLUSION

COL4A1 facilitates growth and metastasis in HCC via activation of FAK-Src signaling. High level of COL4A1 may be a potential biomarker for diagnosis and treatment with FAK or Src inhibitor for HCC.

Growth hormone increases regulator of calcineurin 1-4 (Rcan1-4) mRNA through c-JUN in rat liver

Growth hormone (GH) activates multiple signal transduction pathways. To investigate these pathways, we identified novel genes whose transcription was induced by GH in the liver of hypophysectomized (HPX) rats using the suppression subtractive hybridization technique. We found that regulator of calcineurin 1 (Rcan1) mRNA was upregulated by GH administration. RCAN1 regulates the activity of calcineurin, a Ca/calmodulin-dependent phosphatase. Rcan1 encodes two major transcripts, Rcan1-1 and Rcan1-4, resulting from differential promoter use and first exon choice. We found that a single injection of GH increased the levels of Rcan1-4 mRNA and RCAN1-4 protein transiently, but did not increase Rcan1-1 mRNA in HPX rat liver. Then the molecular mechanism of GH to induce Rcan1-4 transcription was examined in rat hepatoma H4IIE cells. Experiments using inhibitors suggested that c-JUN N-terminal kinase was required for the induction of Rcan1-4 mRNA by GH. GH increased the levels of phosphorylated c-JUN protein and c-Jun mRNA in HPX rat liver. The luciferase and electrophoretic mobility shift assays showed that c-JUN upregulated Rcan1-4 mRNA by binding to the cAMP-responsive element in the upstream of Rcan1 exon 4. These results indicate that GH activates c-JUN to affect the activity of calcineurin by the induction of Rcan1-4 in rat liver.

The RCAN1.4-calcineurin/NFAT signaling pathway is essential for hypoxic adaption of intervertebral discs

Calcipressin-1, also known as regulator of calcineurin 1 (RCAN1), can specifically bind calcineurin at or near the calcineurin A catalytic domain and downregulate calcineurin activity. However, whether RCAN1 affects the hypoxic intervertebral disc (IVD) phenotype through the calcineurin/NFAT signaling pathway remains unclear. First, we confirmed the characteristics of the degenerative nucleus pulposus (NP) by H&E, safranin O/fast green and Alcian blue staining, and detected increased RCAN1 levels in the degenerative NP by immunohistochemistry. Then, we demonstrated that the protein level of RCAN1.4 was higher than that of RCAN1.1 and progressively elevated from the control group to the Pfirrmann grade V group. In vitro, both hypoxia (1% O₂) and overexpression of HIF-1α reduced the protein level of RCAN1.4 in rat NP cells in a dose- and time-dependent manner. We further found that miRNA-124, through a nondegradative pathway (without the proteasome or lysosome), suppressed the expression of RCAN1.4. As expected, calcineurin in NP cells was activated and primarily promoted nuclear translocation of NFATc1 under hypoxia or RCAN1.4 siRNA transfection. Furthermore, SOX9, type II collagen and MMP13 were elevated under hypoxia, RCAN1.4 siRNA transfection or NFATc1 overexpression. Using chromatin immunoprecipitation (ChIP) and a luciferase reporter assay (with mutation), we clarified that NFATc1 increasingly bound the SOX9 promotor region (bp −367~−357). Interaction of HIF-1α and NFATc1 promoted MMP13 transcription. Finally, we found that FK506 reversed hypoxia-induced activation of the calcineurin/NFAT signaling pathway in NP cells and an ex vivo model. Together, these findings show that the RCAN1.4-calcineurin/NFAT signaling pathway has a vital role in the hypoxic phenotype of NP cells. RCAN1.4 might be a therapeutic target for degenerative disc diseases.

Treatments targeting a protein that is overexpressed in damaged spinal cartilage could ease degenerative conditions associated with lower back pain. The intervertebral discs are complex cartilage tissues that absorb forces while allowing the motion of our spines. An immune-promoting enzyme called calcineurin is important in maintaining the supple, gel-like structure of the central part of each disc, the nucleus pulposus (NP). Fendong Zhao and Jian Chen at Zhejiang University School of Medicine Hangzhou, China and co-workers showed that RCAN1.4, a protein known to suppress calcineurin, is overexpressed in damaged human NPs. The team further revealed how a signaling pathway starting with RCAN1.4 suppresses key genes involved in forming the collagen fibers that hold the NP together. They therefore suggest that therapies targeting this protein could benefit patients suffering from disc degeneration diseases.

CD147 regulates melanoma metastasis via the NFAT1-MMP-9 pathway

Although accumulating evidence had revealed that NFAT1 has oncogenic characteristics, the role of this molecule in melanoma cells remains unclear. Previous studies proved that CD147 plays a crucial function in melanoma cell metastasis and invasion through matrix metalloproteinase 9 (MMP-9) expression; however, the details of how CD147 regulates MMP-9 expression remain elusive. In this study, we demonstrated that CD147 and NFAT1 are overexpressed in the tissues of patients with primary and metastatic melanoma, which has shown a positive correlation. Further, we observed that CD147 regulates NFAT1 activation through the [Ca²⁺ ]i-calcineurin pathway. Knockdown of NFAT1 significantly suppresses melanoma metastasis, and we demonstrated that CD147 affects melanoma metastasis in an NFAT1-dependent manner. Moreover, we verified that NFAT1 directly binds to MMP-9 promoter. Inhibition of CD147 expression significantly abrogates MMP-9 promoter luciferase gene reporter activity as well as NFAT1 association with MMP-9 promoter. Taken together, this study demonstrated that CD147 affects MMP-9 expression through regulating NFAT1 activity and provided a novel mechanism by which NFAT1 contributes to melanoma metastasis through the regulation of MMP-9.

Alternative Splicing in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) accounts for the majority of primary liver cancer cases, with more than 850,000 new diagnoses per year globally. Recent trends in the United States have shown that liver cancer mortality has continued to increase in both men and women, while 5-year survival remains below 20%. Understanding key mechanisms that drive chronic liver disease progression to HCC can reveal new therapeutic targets and biomarkers for early detection of HCC. In that regard, many studies have underscored the importance of alternative splicing as a source of novel HCC prognostic markers and disease targets. Alternative splicing of pre-mRNA provides functional diversity to the genome, and endows cells with the ability to rapidly remodel the proteome. Genes that control fundamental processes, such as metabolism, cell proliferation, and apoptosis, are altered globally in HCC by alternative splicing. This review highlights the major splicing factors, RNA binding proteins, transcriptional targets, and signaling pathways that are of key relevance to HCC. We highlight primary research from the past 3-5 years involving functional interrogation of alternative splicing in rodent and human liver, using both large-scale transcriptomic and focused mechanistic approaches. Because this is a rapidly advancing field, we anticipate that it will be transformative for the future of basic liver biology, as well as HCC diagnosis and management.

Direct inhibition of the TLR4/MyD88 pathway by geniposide suppresses HIF-1α-independent VEGF expression and angiogenesis in hepatocellular carcinoma

BACKGROUND AND PURPOSE

As a typical hypervascular tumour, hepatocellular carcinoma (HCC) is predominantly grown through angiogenesis. Geniposide is a promising anti-inflammatory compound found in Gardenia jasminoides, but its effects on the progression of HCC remain untested.

EXPERIMENTAL APPROACH

The anti-HCC effects of geniposide was investigated in cellular models and orthotopic HCC mice. Transcriptional regulation of the VEGF promoter was measured by dual-luciferase reporter assay. The anti-angiogenic action of geniposide was measured by tube formation assay. Both surface plasmon resonance techniques and human phospho-kinase array analysis were utilized to validate the relationship between targets of geniposide and hepatocarcinogenesis.

KEY RESULTS

Geniposide exhibited significant disruption of HCC proliferation, invasion, angiogenesis and lung metastasis in orthotopic HCC mice. Geniposide inhibited secretion of VEGF by HCC and suppressed the migration of endothelial cells and the formation of intra-tumour blood vessels, without cytotoxicity and independently of the transcription factor HIF-1α. Direct inhibition of TLR4 by geniposide led to the shutdown of the TLR4/MyD88 pathway and STAT3/Sp1-dependent VEGF production. However, LPS, an agonist of TLR4, restored STAT3/Sp1-related VEGF production in geniposide-inhibited HCC angiogenesis.

CONCLUSION AND IMPLICATIONS

The direct inhibitory effect of geniposide on TLR4/MyD88 activation contributes to the suppression of STAT3/Sp1-dependent VEGF overexpression in HCC angiogenesis and pulmonary metastasis. This action of geniposide was not affected by stabilization of HIF-1α. Our study offers a novel anti-VEGF mechanism for the inhibition of HCC.

Identification of hub genes in hepatocellular carcinoma using integrated bioinformatic analysis

The molecular mechanisms underlying hepatocellular carcinoma (HCC) progression remain largely undefined. Here, we identified 176 commonly upregulated genes in HCC tissues based on three Gene Expression Omnibus datasets and The Cancer Genome Atlas (TCGA) cohort. We integrated survival and methylation analyses to further obtain 12 upregulated genes for validation. These genes were overexpressed in HCC tissues at the transcription and protein levels, and increased mRNA levels were related to higher tumor grades and cancer stages. The expression of all markers was negatively associated with overall and disease-free survival in HCC patients. Most of these hub genes can promote HCC proliferation and/or metastasis. These 12 hub genes were also overexpressed and had strong prognostic value in many other cancer types. Methylation and gene copy number analyses indicated that the upregulation of these hub genes was probably due to hypomethylation or increased gene copy numbers. Further, the methylation levels of three genes, KPNA2, MCM3, and LRRC1, were associated with HCC clinical features. Moreover, the levels of most hub genes were related to immune cell infiltration in HCC microenvironments. Finally, we identified three upregulated genes (KPNA2, TARBP1, and RNASEH2A) that could comprehensively and accurately provide diagnostic and prognostic value for HCC patients.

Tumor-derived exosomal miR-619-5p promotes tumor angiogenesis and metastasis through the inhibition of RCAN1.4

Tumor-derived exosomes (TEXs) contain enriched miRNAs that act as novel non-invasive biomarkers for cancer diagnosis and play a role in cancer progression. We investigated the exosomal miRNAs that affect cancer progression in non-small cell lung cancer (NSCLC) and identified the specific molecules involved. We identified that specific miRNAs in NSCLC cell-released exosomes can modulate angiogenesis, among which miR-619-5p was the most potent inducer. RCAN1.4 was identified as a target of miR-619-5p and its suppression promoted angiogenesis. Furthermore, the suppression of RCAN1.4 induced cell proliferation and metastasis in NSCLC cells. In patients with NSCLC, the level of RCAN1.4 expression was significantly lower, and that of miR-619-5p significantly higher, in tumor than normal lung tissues. miR-619-5p expression was higher than normal in exosomes isolated from the plasma of NSCLC patients. Finally, hypoxic conditions induced miR-619-5p upload into NSCLC cell-derived exosomes. Our findings indicate that exosomal miR-619-5p promotes the growth and metastasis of NSCLCs by regulating RCAN1.4 and can serve as a diagnostic indicator for these lung cancers.

Self-Assembled and Self-Monitored Sorafenib/Indocyanine Green Nanodrug with Synergistic Antitumor Activity Mediated by Hyperthermia and Reactive Oxygen Species-Induced Apoptosis

Liver cancer is a leading cause of cancer morbidity and mortality worldwide, especially in China. Sorafenib (SRF) is currently the most commonly used systemic agent against advanced hepatocellular carcinoma (HCC), which is the most common type of liver cancer. However, HCC patients have only limited benefit and suffer a serious side effect from SRF. Therefore, new approaches are urgently needed to improve the therapeutic effectiveness of SRF and reduce its side effect. In our current study, we developed a self-imaging and self-delivered nanodrug with SRF and indocyanine (ICG) to improve the therapeutic effect of sorafenib against HCC. With the π-π stacking effect between SRF and ICG, a one-step nanoprecipitation method was designed to obtain the SRF/ICG nanoparticles (SINP) via self-assembly. Pluronic F127 was used to shield the SINP to further improve the stability in an aqueous environment. The stability, photothermal effect, cell uptake, ROS production, cytotoxicity, tumor imaging, and tumor-targeting and tumor-killing efficacy of the SINP were evaluated in vitro and in vivo by using an HCC cell line Huh7 and its xenograft tumor model. We found that our designed SINP showed monodisperse stability and efficient photothermal effect both in vitro and in vivo. SINP could rapidly enter Huh7 cells and achieve potent cytotoxicity under near-infrared (NIR) laser irradiation partly by producing a great amount of reactive oxygen species (ROS). SINP had significantly improved stability and blood half-life, and could specifically target tumor via the enhanced permeability and retention (EPR) effect in vivo. In addition, SINP showed improved cytotoxicity in both subcutaneous and orthotopic HCC implantation models in vivo. Overall, this rationally designed sorafenib delivery system with a very high loading capacity (33%) has considerably improved antitumor efficiency in vitro and could completely eliminate subcutaneous tumors without any regrowth in vivo. In conclusion, our self-imaging and self-delivered nanodrug could improve the efficacy of SRF and might be a potential therapy for HCC patients.

The clinical significance of lipopolysaccharide binding protein in hepatocellular carcinoma

Lipopolysaccharide binding protein (LBP) has been reported to be associated with prognosis in colorectal carcinoma and renal cell carcinoma; however, the clinical significance of LBP in human primary hepatocellular carcinoma (HCC) is inconclusive. We aimed to investigate the clinical significance and prognostic value of LBP in human primary HCC. In the present study, 346 patients with HCC who underwent curative resection were retrospectively analyzed. LBP protein expression was evaluated using western blot analysis and immunohistochemistry. LBP scores collected from immunohistochemical analysis were obtained by multiplying staining intensity and the percentage of positive cells. An outcome-based best cutoff-point was calculated by X-tile software. Moreover, Kaplan-Meier curves and Cox regressions were used for prognosis evaluation. LBP was frequently overexpressed in HCC compared with that in peritumor tissues (five pairs by western blot analysis, P=0.0533; 77 pairs by immunohistochemistry, P=0.0171), and LBP expression was positively associated with tumor-node-metastasis stage and tumor differentiation. Patients who had high LBP expression had decreased overall survival and time to recurrence compared with patients with low LBP expression. Furthermore, patients who were both serum α-fetoprotein positive and had high LBP expression had poor prognoses. Univariate and multivariate Cox analyses indicated that this combination was an independent prognostic factor [overall survival: Hazard ratio (HR), 1.458; 95% confidence interval (CI), 1.158–1.837; P=0.001; time to recurrence: HR,1.382; 95% Cl, 1.124–1.700; P=0.002]. In conclusion, LBP is highly expressed in HCC, and high LBP expression combined with serum α-fetoprotein may predict poor outcomes in patients with HCC following curative resection.

Methylation of RCAN1.4 mediated by DNMT1 and DNMT3b enhances hepatic stellate cell activation and liver fibrogenesis through Calcineurin/NFAT3 signaling

Background: Liver fibrosis is characterized by extensive deposition of extracellular matrix (ECM) components in the liver. RCAN1 (regulator of calcineurin 1), an endogenous inhibitor of calcineurin (CaN), is required for ECM synthesis during hypertrophy of various organs. However, the functional role of RCAN1 in liver fibrogenesis has not yet been addressed. Methods: We induced experimental liver fibrosis in mice by intraperitoneal injection of 10 % CCl4 twice a week. To investigate the functional role of RCAN1.4 in the progression of liver fibrosis, we specifically over-expressed RCAN1.4 in mice liver using rAAV8-packaged RCAN1.4 over-expression plasmid. Following the establishment of the fibrotic mouse model, primary hepatic stellate cells were isolated. Subsequently, we evaluated the effect of RCAN1.4 on hepatic fibrogenesis, hepatic stellate cell activation, and cell survival. The biological role and signaling events for RCAN1 were analyzed by protein-protein interaction (PPI) network. Bisulfite sequencing PCR (BSP) was used to predict the methylated CpG islands in the RCAN1.4 gene promoter. We used the chromatin immunoprecipitation (ChIP assay) to investigate DNA methyltransferases which induced decreased expression of RCAN1.4 in liver fibrosis. Results: Two isoforms of RCAN1 protein were expressed in CCl4-induced liver fibrosis mouse model and HSC-T6 cells cultured with transforming growth factor-beta 1 (TGF-β1). RCAN1 isoform 4 (RCAN1.4) was selectively down-regulated in vivo and in vitro. The BSP analysis indicated the presence of two methylated sites in RCAN1.4 promoter and the downregulated RCAN1.4 expression levels could be restored by 5-aza-2'-deoxycytidine (5-azadC) and DNMTs-RNAi transfection in vitro. ChIP assay was used to demonstrate that the decreased RCAN1.4 expression was associated with DNMT1 and DNMT3b. Furthermore, we established a CCl4-induced liver fibrosis mouse model by injecting the recombinant adeno-associated virus-packaged RCAN1.4 (rAAV8-RCAN1.4) over-expression plasmid through the tail vein. Liver- specific-over-expression of RAN1.4 led to liver function recovery and alleviated ECM deposition. The key protein (a member of the NFAT family of proteins) identified on PPI network data was analyzed in vivo and in vitro. Our results demonstrated that RCAN1.4 over-expression alleviates, whereas its knockdown exacerbates, TGF-β1-induced liver fibrosis in vitro in a CaN/NFAT3 signaling-dependent manner. Conclusions: RCAN1.4 could alleviate liver fibrosis through inhibition of CaN/NFAT3 signaling, and the anti-fibrosis function of RCAN1.4 could be blocked by DNA methylation mediated by DNMT1 and DNMT3b. Thus, RCAN1.4 may serve as a potential therapeutic target in the treatment of liver fibrosis.

MDM2-NFAT1 dual inhibitor, MA242: Effective against hepatocellular carcinoma, independent of p53

The overexpression of the MDM2 oncoprotein frequently occurs in hepatocellular carcinoma (HCC). Small molecules that inhibit MDM2-p53 binding show efficacy against p53 wild-type HCC, but most patients have p53-mutant tumors and intrinsic resistance to such MDM2 inhibitors. We have recently discovered that the NFAT1 transcription factor upregulates MDM2 expression, but the role of NFAT1 in HCC is not fully understood. The present study was designed to develop a dual-targeting (MDM2 and NFAT1) strategy for the treatment of HCC. We herein demonstrate that high expression levels of NFAT1 and MDM2 are independent predictors of a poor prognosis in patients with HCC. We have also identified a MDM2 and NFAT1 dual inhibitor (termed MA242) that induces MDM2 auto-ubiquitination and degradation and represses NFAT1-mediated MDM2 transcription. MA242 profoundly inhibits the growth and metastasis of HCC cells in vitro and in vivo, independent of p53. The present efficacy and mechanistic studies provide proof-of-principle data to support the therapeutic value of this dual targeting strategy in future drug discovery.

Identification and validation of a potent multi-mRNA signature for the prediction of early relapse in hepatocellular carcinoma

Early recurrence of hepatocellular carcinoma (HCC) is implicated in poor patient survival and is the major obstacle to improving prognosis. The current staging systems are insufficient for accurate prediction of early recurrence, suggesting that additional indicators for early recurrence are needed. Here, by analyzing the gene expression profiles of 12 Gene Expression Omnibus data sets (n = 1533), we identified 257 differentially expressed genes between HCC and non-tumor tissues. Least absolute shrinkage and selection operator regression model was used to identify a 24-messenger RNA (mRNA)-based signature in discovery cohort GSE14520. With specific risk score formula, patients were divided into high- and low-risk groups. Recurrence-free survival within 2 years (early-RFS) was significantly different between these two groups in discovery cohort [hazard ratio (HR): 7.954, 95% confidence interval (CI): 4.596–13.767, P < 0.001], internal validation cohort (HR: 8.693, 95% CI: 4.029–18.754, P < 0.001) and external validation cohort (HR: 5.982, 95% CI: 3.414–10.480, P < 0.001). Multivariable and subgroup analyses revealed that the 24-mRNA-based classifier was an independent prognostic factor for predicting early relapse of patients with HCC. We further developed a nomogram integrating the 24-mRNA-based signature and clinicopathological risk factors to predict the early-RFS. The 24-mRNA-signature-integrated nomogram showed good discrimination (concordance index: 0.883, 95% CI: 0.836–0.929) and calibration. Decision curve analysis demonstrated that the 24-mRNA-signature-integrated nomogram was clinically useful. In conclusion, our 24-mRNA signature is a powerful tool for early-relapse prediction and will facilitate individual management of HCC patients.

NF-κB signaling pathway inhibition suppresses hippocampal neuronal apoptosis and cognitive impairment via RCAN1 in neonatal rats with hypoxic-ischemic brain damage

NF-κB is a core transcription factor, the activation of which can lead to hypoxic-ischemic brain damage (HIBD), while RCAN1 plays a protective role in HIBD. However, the relationship between NF-κB and RCAN1 in HIBD remains unclear. This study aimed to explore the mechanism of NF-κB signaling pathway in hippocampal neuron apoptosis and cognitive impairment of neonatal rats with HIBD in relation to RCAN1. Initially, microarray analysis was used to determine the differentially expressed genes related to HIBD. After the establishment of HIBD rat models, gain- or loss-of-function assay was performed to explore the functional role of NF-κB signaling pathway in HIBD. Then, the learning and memory ability of rats was evaluated. Expression of RCAN1, NF-κB signaling pathway-related genes and glial fibrillary acidic protein (GFAP), S-100β and acetylcholine (Ach) level, and acetylcholinesterase (AchE) activity were determined with neuron apoptosis detected to further explore the function of NF-κB signaling pathway. RCAN1 could influence the development of HIBD. In the HIBD model, the expression of RCAN1 and NF-κB-related genes increased, and NF-κB p65 showed a significant nuclear shift. By activation of NF-κB or overexpression of RCAN1, the number of neuronal apoptosis, S-100β protein level, and AchE level increased significantly, Ach activity decreased significantly, and GFAP positive cells increased. In addition, after the activation of NF-κB or overexpression of RCAN1, the learning and memory ability of HIBD rats was inhibited. All the results show that activation of NF-κB signaling pathway promotes RCAN1 expression, thus increasing neuronal apoptosis and aggravating cognitive impairment in HIBD rats.

NFAT1-Mediated Regulation of NDEL1 Promotes Growth and Invasion of Glioma Stem-like Cells

Glioma stem-like cells (GSC) promote tumor generation and progression. However, the mechanism of GSC induction or maintenance is largely unknown. We previously demonstrated that the calcium-responsive transcription factor nuclear factor of activated T cells-1 (NFAT1) is activated in glioblastomas and regulates the invasion of tumor cells. In this study, we further explored the role of NFAT1 in GSC. We found that NFAT1 expression was associated with an aggressive phenotype and predicted poor survival in gliomas. Compared with normal glioma cells, NFAT1 was upregulated in GSC. NFAT1 knockdown reduced GSC viability, invasion, and self-renewal in vitro and inhibited tumorigenesis in vivo, whereas NFAT1 overexpression enhanced the growth and invasion of GSCs. RNA sequencing showed that NFAT1 depletion was associated with reduced neurodevelopment protein 1-like 1 (NDEL1, a potential downstream target of NFAT1) expression, whereas NFAT1 overexpression induced NDEL1 expression. In addition, NFAT1 regulated the promoter activities of NDEL1, whereas rescue of NDEL1 in NFAT1-silenced GSC partially restored tumor growth and invasion. Upregulation of NFAT1-NDEL1 signaling elevated Erk activation, increased protein levels of stemness markers in GSC, and resulted in de-differentiation of normal neuronal cells and astrocytes. Our results indicate that NFAT1 controls the growth and invasion of GSC partially through regulation of NDEL1. Targeting the NFAT1-NDEL1 axis therefore might be of potential benefit in the treatment of patients with glioma. SIGNIFICANCE: NFAT1 controls the growth and invasion of GSCs, partially by regulating NDEL1. Targeting the NFAT1-NDEL1 axis might provide opportunities in treating patients with glioma.

Downregulated expression of CFHL1 is associated with unfavorable prognosis in postoperative patients with hepatocellular carcinoma

Complement factor H-related protein 1 (CFHL1) was recently reported to be a potential biomarker in several types of cancer. CFHL1, however, has not been found to be of prognostic value in hepatocellular carcinoma (HCC) to date. In the present study, the expression levels of CFHL1 were evaluated in 8 pairs fresh frozen tissue samples using western blotting. Furthermore, the expression level of CFHL1 was evaluated in 76 pairs of formalin-fixed, paraffin-embedded (FFPE) HCC and peritumoral tissues (expression pattern cohort), and 278 FFPE HCC tissues (prognostic cohort) using tissue microarray-based immunohistochemistry. The Kaplan-Meier method, Cox regression proportional hazard model and receiver operating characteristic curve analysis were used to evaluate prognostic factors. The expression level of CFHL1 was reduced in HCC tissues in 67.1% (51/76) of the cases compared with the corresponding peritumoral tissues. Survival analyses indicated that patients with HCC with low CFHL1 expression had a worse time-to-recurrence (TTR) and overall survival (OS) compared with those with high CFHL1 expression in the prognostic cohort (P=0.002 for OS and P=0.017 for TTR). Both univariate and multivariate analyses indicated that CHFL1 was an independent prognostic factor for TTR and OS (P=0.017 and P=0.002, respectively). In addition, The Cancer Genome Atlas (TCGA) and Human Protein Atlas were used for further validation. Furthermore, a prognostic model included tumor size, tumor number, liver cirrhosis and CFHL1 expression was evaluated. The results of the present study demonstrated that CFHL1 was downregulated in HCC and its level was associated with patient prognosis; therefore, CFHL1 is a potential prognostic marker for HCC.