Chromosome 8p tumor suppressor genes SH2D4A and SORBS3 cooperate to inhibit interleukin-6 signaling in hepatocellular carcinoma

UBE2T mediates SORBS3 ubiquitination to enhance IL-6/STAT3 signaling and promote lung adenocarcinoma progression

UBE2T is an oncogene in varying tumors, including lung adenocarcinoma (LUAD). SORBS3 is an important signaling regulatory protein that plays a crucial role in many cancers. This study aimed to investigate whether UBE2T promoted LUAD development by mediating the ubiquitination of SORBS3 and further explore its mechanism. Bioinformatics analysis was conducted to examine the expression of SORBS3 in LUAD tissues. Cell Counting Kit-8, Transwell, and flow cytometry were employed to analyze the cellular functions of SORBS3. Co-immunoprecipitation and ubiquitination analysis were employed to observe the correlation between UBE2T and SORBS3. In vitro and in vivo experiments verified the role of UBE2T in mediating SORBS3 ubiquitination to enhance interleukin-6/signal transducer and activator of transcription 3 (IL-6/STAT3) signaling and promote LUAD development. We observed significant downregulation of SORBS3 in LUAD tissues and cells. Furthermore, SORBS3 inhibited the proliferation, migration, and invasion of LUAD cells, while facilitating apoptosis in vitro. UBE2T enhanced IL-6/STAT3 signaling by mediating ubiquitination and degradation of SORBS3, thereby promoting LUAD progression. Additionally, this mechanism was further validated in the xenograft animal model in vivo. This study confirmed that UBE2T-mediated SORBS3 ubiquitination enhanced IL-6/STAT3 signaling and promoted LUAD progression, providing a novel therapeutic target for LUAD.

SH2D4A inhibits esophageal squamous cell carcinoma progression through FAK/PI3K/AKT signaling pathway

Esophageal squamous cell carcinoma (ESCC), one of the most common malignant tumors, is now afflicting approximately 80% of patients diagnosed with esophageal cancers. The therapeutic effect and prognosis of ESCC remain inadequate due to the unusual early symptoms and rapid malignant progression. SH2 Domain containing 4 A (SH2D4A) is downregulated in malignancies and is closely associated with tumor progression. However, neither the biological functions nor the fundamental mechanisms of SH2D4A on ESCC are known. In this study, it was found that SH2D4A is downregulated in ESCC tissues and cell lines. Incorporating immunohistochemistry and clinicopathological findings, we determined that decreased SH2D4A expression was substantially associated with adverse clinical outcomes. Overexpression of SH2D4A inhibited cell proliferation and migration, whereas suppressing SH2D4A has the opposite effect. SH2D4A mechanistically inhibited cells from proliferating and migrating through the FAK/PI3K/AKT signaling pathway. Furthermore, the results of xenograft tumor growth confirmed the preceding findings. In conclusion, our findings reveal that SH2D4A is a gene which can serve as a cancer suppressor in ESCC and may inhibits the ESCC progression by interfering with the FAK/PI3K/AKT signaling pathway. SH2D4A could act as a target for diagnostic or therapeutic purpose in ESCC.

Elevated ZNF704 expression is associated with poor prognosis of uveal melanoma and promotes cancer cell growth by regulating AKT/mTOR signaling

BACKGROUND

Uveal melanoma (UM) is the most common intraocular malignancy in adults, with a poor survival prognosis. To date, limited understanding of UM's molecular mechanisms constitutes an obstacle to developing effective therapy. In this study, we examined key regulators mediating UM progression and their clinical relevance.

METHODS

Transcriptomics of UM patients and cells were analyzed via RNA sequencing and bioinformatic analysis. Zinc finger protein 704 (ZNF704) was identified as prognosis-related biomarker for UM based on clinical characteristics and RNA-seq data from The Cancer Genome Atlas (TCGA). Gene expression was knocked down by specific shRNAs/siRNAs and overexpressed by transfection with plasmids inserted with investigated gene cDNA. Cell proliferation, viability and invasion abilities were determined by CCK8, colony formation and transwell assays, respectively. For cell cycle and apoptosis, cells were PI or PI/Annexin V-APC stained and analyzed by flow cytometry. Standard immunoblotting and quantitative RT-PCR were employed to assess the mRNA and protein abundance. To determine tumor growth in vivo, 4-week-old BALB/c-nu immune-deficient nude mice were inoculated with tumor cells.

RESULTS

Analysis of differential expressed genes (DEGs) and survival analysis identified ZNF704 as a novel biomarker of UM. Prognostic analysis indicated ZNF704 as an independent predictor of UM overall survival. Expression of ZNF704 is elevated in UM tissues relative to adjacent normal choroid tissues. Knockdown of ZNF704 suppressed the growth and migration of UM cells and vice versa. In addition, expression of ZNF704 arrest UM cells at G0/G1 phase and inhibit cell apoptosis. RNA sequencing analysis indicated that SORBS3 were dysregulated after ZNF704 downregulation. Gene Set Enrichment Analysis (GSEA) revealed that upon ZNF704 knowndown, genes related with PI3K/AKT/mTOR, EMT and metastasis are enriched. Mechanistically, ZNF704 activates AKT/mTOR/glycolysis signaling pathway in UM cells. Moreover, expression of SORBS3 is downregulated by ZNF704 and knockdown of SORBS3 restored tumor cell viability in ZNF704 silenced cells.

CONCLUSIONS

ZNF704 predicts poor prognosis of UM and exhibit pro-oncogenic effect in UM progression in vivo and in vitro, mediated through AKT/mTOR signaling pathway and suppression of SORBS3 expression.

Cancer and Alzheimer's Inverse Correlation: an Immunogenetic Analysis

Numerous studies have demonstrated an inverse link between cancer and Alzheimer's disease (AD), with data suggesting that people with Alzheimer's have a decreased risk of cancer and vice versa. Although other studies have investigated mechanisms to explain this relationship, the connection between these two diseases remains largely unexplained. Processes seen in cancer, such as decreased apoptosis and increased cell proliferation, seem to be reversed in AD. Given the need for effective therapeutic strategies for AD, comparisons with cancer could yield valuable insights into the disease process and perhaps result in new treatments. Here, through a review of existing literature, we compared the expressions of genes involved in cell proliferation and apoptosis to establish a genetic basis for the reciprocal association between AD and cancer. We discuss an array of genes involved in the aforementioned processes, their relevance to both diseases, and how changes in those genes produce varying effects in either disease.

SH2D4A promotes centrosome maturation to support spindle microtubule formation and mitotic progression

Mitotic progression requires the precise formation of spindle microtubules based on mature centrosomes. During the G2/M transition, centrosome maturation progresses, and associated microtubules bundle to form mitotic spindle fibers and capture the chromosomes for alignment at the cell equator. Mitotic kinases-induced phosphorylation signaling is necessary for these processes. Here, we identified SH2 domain-containing protein 4A (SH2D4A/PPP1R38) as a new mitotic regulator. SH2D4A knockdown delays mitotic progression. The time-lapse imaging analysis showed that SH2D4A specifically contributes to the alignment of chromosomes. The cold treatment assay and microtubule regrowth assay indicated that SH2D4A promotes microtubule nucleation to support kinetochore-microtubule attachment. This may be due to the centrosome maturation by SH2D4A via centrosomal recruitment of pericentriolar material (PCM) such as cep192, γ-tubulin, and PLK1. SH2D4A was found to be a negative regulator of PP1 phosphatase. Consistently, treatment with a PP1 inhibitor rescues SH2D4A-knockdown-induced phenotypes, including the microtubule nucleation and centrosomal recruitment of active PLK1. These results suggest that SH2D4A is involved in PCM recruitment to centrosomes and centrosome maturation through attenuation of PP1 phosphatases, accelerating the spindle formation and supporting mitotic progression.

A novel 16-gene alternative mRNA splicing signature predicts tumor relapse and indicates immune activity in stage I–III hepatocellular carcinoma

Background: Hepatocellular carcinoma (HCC) is a lethal disease with high relapse and dismal survival rates. Alternative splicing (AS) plays a crucial role in tumor progression. Herein, we aim to integratedly analyze the relapse-associated AS events and construct a signature predicting tumor relapse in stage I–III HCC.

Methods: AS events of stage I–III HCC with tumor relapse or long-term relapse-free survival were profiled to identify the relapse-associated AS events. A splicing network was set up to analyze the correlation between the relapse-associated AS events and splicing factors. Cox regression analysis and receiver operating characteristic curve were performed to develop and validate the relapse-predictive AS signature. Single-sample gene set enrichment analysis (ssGSEA) and the ESTIMATE algorithm were used to assess the immune infiltration status of the HCC microenvironment between different risk subgroups. Unsupervised cluster analysis was conducted to assess the relationship between molecular subtypes and local immune status and clinicopathological features.

Results: In total, 2441 ASs derived from 1634 mRNA were identified as relapse-associated AS events. By analyzing the proteins involved in the relapse-associated AS events, 1573 proteins with 11590 interactions were included in the protein–protein interaction (PPI) network. In total, 16 splicing factors and 61 relapse-associated AS events with 85 interactions were involved in the splicing network. The relevant genes involved in the PPI network and splicing network were also analyzed by Gene Ontology enrichment analysis. Finally, we established a robust 16-gene AS signature for predicting tumor relapse in stage I–III HCC with considerable AUC values in all of the training cohort, testing cohort, and entire cohort. The ssGSEA and ESTIMATE analyses showed that the AS signature was significantly associated with the immune status of the HCC microenvironment. Moreover, four molecular subgroups with distinguishing tumor relapse modes and local immune status were also revealed.

Conclusion: Our study built a novel 16-gene AS signature that robustly predicts tumor relapse and indicates immune activity in stage I–III HCC, which may facilitate the deep mining of the mechanisms associated with tumor relapse and tumor immunity and the development of novel individualized treatment targets for HCC.

STAT1 and STAT3 Exhibit a Crosstalk and Are Associated with Increased Inflammation in Hepatocellular Carcinoma

Simple Summary

Liver cancer is the fourth-leading cause of cancer-related mortality worldwide and lacks effective therapies. Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) are the two most common types of liver cancer and both are associated with underlying inflammatory diseases. Thereby, interleukin-6 (IL-6)-mediated STAT3 signaling is critically involved in early carcinogenesis and disease progression. Here, we assessed the interplay between STAT1 and STAT3 in IL-6 signaling in vitro and studied the activation of STAT1 and STAT3 in a cohort of 124 HCC and a cohort of 138 CCA patients by immunohistochemistry. We found that IL-6 induced STAT1 transcriptional activity upon STAT3 depletion, suggesting that HCC tumor cells may activate both STAT1 and STAT3 signaling under pro-inflammatory conditions. Furthermore, HCC patient tissues showed a strong positive correlation of STAT1 and STAT3 activation in distinct patient groups. These patients also exhibited a high degree of immune cell infiltration, suggesting that these tumors are immune “hot”.

Abstract

Liver cancers, which are mostly hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), are very aggressive tumors with poor prognosis. Therapeutic options with curative intent are largely limited to surgery and available systemic therapies show limited benefit. Signal transducer and activator of transcription 1 (STAT1) and 3 (STAT3) are key transcription factors activated by pro-inflammatory cytokines such as interferon-γ (IFN-γ) and interleukin-6 (IL-6). In this study, we combined in vitro cell culture experiments and immunohistochemical analyses of human HCC (N = 124) and CCA (N = 138) specimens. We observed that in the absence of STAT3, IL-6 induced the activation of STAT1 and its target genes suggesting that IL-6 derived from the tumor microenvironment may activate both STAT1 and STAT3 target genes in HCC tumor cells. In addition, STAT1 and STAT3 were highly activated in a subset of HCC, which exhibited a high degree of infiltrating CD8- and FOXP3-positive immune cells and PD-L1 expression. Our results demonstrate that STAT1 and STAT3 are expressed and activated in HCC and tumor infiltrating immune cells. In addition, HCC cases with high STAT1 and STAT3 expression also exhibited a high degree of immune cell infiltration, suggesting increased immunological tolerance.

SH2D4A downregulation due to loss of chromosome 8p is associated with poor prognosis and low T cell infiltration in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) develops through chromosomal instability (CIN) or microsatellite instability (MSI) due to deficient mismatch-repair (dMMR). We aimed to characterise novel cancer-associated genes that are downregulated upon malignant transformation in microsatellite stable (MSS) CRCs, which typically exhibit CIN with proficient mismatch-repair (pMMR).

METHODS

Comprehensive screening was conducted on adenomas, MSI/MSS CRCs and cell lines, followed by copy number analysis, and their genetic and prognostic relevance was confirmed in microarray and RNA-seq cohorts (n = 3262, in total). Immunohistochemistry for SH2D4A was performed in 524 specimens of adenoma, carcinoma in situ and dMMR/pMMR CRC. The functional role of SH2D4A was investigated using CRC cell lines.

RESULTS

A set of 11 genes, including SH2D4A, was downregulated during the adenoma-carcinoma sequence in MSS/CIN CRCs, mainly due to chromosome 8p deletions, and their negative prognostic impact was validated in independent cohorts. All adenomas were SH2D4A positive, but a subset of CRCs (5.3%) lacked SH2D4A immunohistochemical staining, correlating with poor prognosis and scarce T cell infiltration. SH2D4A depletion did not affect cell proliferation or IL-6-induced STAT3 phosphorylation.

CONCLUSIONS

Our findings suggest that downregulation of multiple genes on chromosome 8p, including SH2D4A, cooperatively contribute to tumorigenesis, resulting in the immune cold tumour microenvironment and poor prognosis.

Vinexin contributes to autophagic decline in brain ageing across species

Autophagic decline is considered a hallmark of ageing. The activity of this intracytoplasmic degradation pathway decreases with age in many tissues and autophagy induction ameliorates ageing in many organisms, including mice. Autophagy is a critical protective pathway in neurons and ageing is the primary risk factor for common neurodegenerative diseases. Here, we describe that autophagosome biogenesis declines with age in mouse brains and that this correlates with increased expression of the SORBS3 gene (encoding vinexin) in older mouse and human brain tissue. We characterise vinexin as a negative regulator of autophagy. SORBS3 knockdown increases F-actin structures, which compete with YAP/TAZ for binding to their negative regulators, angiomotins, in the cytosol. This promotes YAP/TAZ translocation into the nucleus, thereby increasing YAP/TAZ transcriptional activity and autophagy. Our data therefore suggest brain autophagy decreases with age in mammals and that this is likely, in part, mediated by increasing levels of vinexin.

Prohibitin, STAT3 and SH2D4A physically and functionally interact in tumor cell mitochondria

Chromosome 8p is frequently deleted in various cancer entities and has been shown to correlate with poor patient survival. SH2D4A is located on chromosome 8p and prevents the nuclear translocation of the pro-tumorigenic transcription factor STAT3. Here, we investigated the interaction of SH2D4A and STAT3 to shed light on the non-canonical functions of STAT3 in cooperation with the tumor suppressor SH2D4A. Using an immunoprecipitation-mass spectrometry (IP-MS) approach, we identified the mitochondrial scaffold proteins prohibitin 1 (PHB1) and prohibitin 2 (PHB2) among other proteins to potentially bind to SH2D4A. Co-immunoprecipitation and proximity ligation assays confirmed direct interactions of STAT3, PHB1, and SH2D4A in situ and in vitro. In addition, cell fractionation and immunofluorescence staining revealed co-localization of these proteins with mitochondria. These interactions were selectively interrupted by the small molecule and PHB ligand FL3. Furthermore, FL3 led to a reduction of STAT3 protein levels, STAT3 transcriptional activity, and HIF1α protein stabilization upon dimethyloxalylglycine (DMOG) treatment. Besides, mitochondrial fusion and fission markers, L-OPA1, Mfn1, and FIS1, were dysregulated upon FL3 treatment. This dysregulated morphology was accompanied by significant reduction of mitochondrial respiration, thus, FL3 significantly diminished mitochondrial respirational capacity. In contrast, SH2D4A knockout increased mitochondrial respiration, whereas FL3 reversed the effect of SH2D4A knockout. The here described results indicate that the interaction of SH2D4A and PHB1 is involved in the mitochondrial function and integrity. The demonstrated interaction with STAT3, accompanied by its reduction of transcriptional activity, further suggests that SH2D4A is linking STAT3 to its mitochondrial functions, and inhibition of PHB-interaction may have therapeutic effects in tumor cells with STAT3 activation.

Analysis of genomic pathogenesis according to the revised Bethesda guidelines and additional criteria

PURPOSE

As few genotype-phenotype correlations are available for nonsyndromic hereditary colorectal cancer (CRC), we implemented genomic analysis on the basis of the revised Bethesda guideline (RBG) and extended (12 items) to verify possible subtypes.

METHODS

Patients with sporadic CRC (n = 249) were enrolled, stratified according to the revised Bethesda guidelines (RBG+ and RBG- groups) plus additional criteria. Exome/transcriptome analyses (n = 98) and cell-based functional assays were conducted.

RESULTS

We detected 469 somatic and 830 germline gene mutations differing significantly between the positive and negative groups, associated with 12 RBG items/additional criteria. Twenty-one genes had significantly higher mutation rates in left, relative to right, colon cancer, while USP40, HCFC1, and HSPG2 mutation rates were higher in rectal than colon cancer. FAT4 mutation rates were lower in early-onset CRC, in contrast to increased rates in microsatellite instability (MSI)-positive tumors, potentially defining an early-onset microsatellite-stable subtype. The mutation rates of COL6A5 and MGAM2 were significantly and SETD5 was assumably, associated CRC pedigree with concurrent gastric cancer (GC). The predicted deleterious/damaging germline variants, SH2D4A rs35647122, was associated with synchronous/metachronous CRC with related tumors, while NUP160 rs381660 and KRTAP27-1 rs2244485 were potentially associated with a GC pedigree and less strictly defined hereditary CRC, respectively. SH2D4A and NUP160 acted as oncogenic facilitators.

CONCLUSION

Our limited genomic analysis for RBG and additional items suggested that specific somatic alterations in the respective items may enlighten relevant pathogenesis along with the knowledge of germline mutations. Further validation is needed to indicate appropriate surveillance in suspected individuals.

RNA Sequencing of Hepatobiliary Cancer Cell Lines: Data and Applications to Mutational and Transcriptomic Profiling

Cancer cell lines allow the identification of clinically relevant alterations and the prediction of drug response. However, sequencing data for hepatobiliary cancer cell lines in general, and particularly gallbladder cancer (GBC), are sparse. Here, we apply RNA sequencing to characterize 10 GBC, eight hepatocellular carcinoma, and five cholangiocarcinoma (CCA) cell lines. RNA extraction, quality control, library preparation, sequencing, and pre-processing of sequencing data were implemented using state-of-the-art techniques. Public data from the MSK-IMPACT database and a large cohort of Japanese biliary tract cancer patients were used to illustrate the usage of the released data. The total number of exonic mutations varied from 7207 for the cell line NOZ to 9760 for HuCCT1. Researchers planning experiments that require TP53 mutations could use the cell lines NOZ, OCUG-1, SNU308, or YoMi. Mz-Cha-1 showed mutations in ATM, SNU308 presented SMAD4 mutations, and the only investigated cell line that showed ARID1A mutations was GB-d1. SNU478 was the cell line with the global gene expression pattern most similar to GBC, intrahepatic CCA, and extrahepatic CCA. EGFR, KMT2D, and KMT2C generally presented a higher expression in the investigated cell lines than in Japanese primary GBC tumors. We provide the scientific community with detailed mutation and gene expression data, together with three showcase applications, with the aim of facilitating the design of future in vitro cell culture assays for research on hepatobiliary cancer.

Systematic review of the roles of interleukins in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a primary liver cancer with high morbidity and mortality that is often accompanied by immune system disorders and local lymphocyte infiltration. Tumor-infiltrating lymphocytes, cancer cells, stromal cells, and the numerous cytokines they produce, such as chemokines, interferons, tumor necrosis factors, and interleukins, collectively constitute the tumor microenvironment. As a main type of immune effector, interleukin plays opposing roles in regulating tumor cell progression, adhesion, and migration according to its different subtypes. Many reports have concentrated on the roles that interleukins play in HCC, but understanding them systematically remains challenging. This study reviewed the current data to comprehensively summarize the relationships between HCC progression and human interleukin gene families.

Prognostic Value and Potential Regulatory Mechanism of Alternative Splicing in Geriatric Breast Cancer

Breast cancer has the highest mortality and morbidity among women, especially in elderly women over 60 years old. Abnormal alternative splicing (AS) events are associated with the occurrence and development of geriatric breast cancer (GBC), yet strong evidence is lacking for the prognostic value of AS in GBC and the regulatory network of AS in GBC, which may highlight the mechanism through which AS contributes to GBC. In the present study, we obtained splicing event information (SpliceSeq) and clinical information for GBC from The Cancer Genome Atlas, and we constructed a GBC prognosis model based on AS events to predict the survival outcomes of GBC. Kaplan–Meier analysis was conducted to evaluate the predictive accuracy among different molecular subtypes of GBC. We conducted enrichment analysis and constructed a splicing network between AS and the splicing factor (SF) to examine the possible regulatory mechanisms of AS in GBC. We constructed eight prognostic signatures with very high statistical accuracy in predicting GBC survival outcomes from 45,421 AS events of 10,480 genes detected in 462 GBC patients; the prognostic model based on exon skip (ES) events had the highest accuracy, indicating its significant value in GBC prognosis. The constructed regulatory SF–AS network may explain the potential regulatory mechanism between SF and AS, which may be the mechanism through which AS events contribute to GBC survival outcomes. The findings confirm that AS events have a significant prognostic value in GBC, and we found a few effective prognostic signatures. We also hypothesized the mechanism underlying AS in GBC and discovered a potential regulatory mechanism between SF and AS.

NOTCH target gene HES5 mediates oncogenic and tumor suppressive functions in hepatocarcinogenesis

NOTCH receptor signaling plays a pivotal role in liver homeostasis and hepatocarcinogenesis. However, the role of NOTCH pathway mutations and the NOTCH target gene HES5 in liver tumorigenesis are poorly understood. Here we performed whole-exome sequencing of 54 human HCC specimens and compared the prevalence of NOTCH pathway component mutations with the TCGA-LIHC cohort (N = 364). In addition, we functionally characterized the NOTCH target HES5 and the patient-derived HES5-R31G mutation in vitro and in an orthotopic mouse model applying different oncogenic backgrounds, to dissect the role of HES5 in different tumor subgroups in vivo. We identified nonsynonymous mutations in 14 immediate NOTCH pathway genes affecting 24.1% and 16.8% of HCC patients in the two independent cohorts, respectively. Among these, the HES5-R31G mutation was predicted in silico to have high biological relevance. Functional analyses in cell culture showed that HES5 reduced cell migration and clonogenicity. Further analyses revealed that the patient-derived HES5-R31G mutant protein was non-functional due to loss of DNA binding and greatly reduced nuclear localization. Furthermore, HES5 exhibited a negative feedback loop by directly inhibiting the NOTCH target HES1 and downregulated the pro-proliferative MYC targets ODC1 and LDHA. Interestingly, HES5 inhibited MYC-dependent hepatocarcinogenesis, whereas it promoted AKT-dependent liver tumor formation and stem cell features in a murine model. Thus, NOTCH pathway component mutations are commonly observed in HCC. Furthermore, the NOTCH target gene HES5 has both pro- and anti-tumorigenic functions in liver cancer proposing a driver gene dependency and it promotes tumorigenesis with its interaction partner AKT.

Karyopherin α2-dependent import of E2F1 and TFDP1 maintains protumorigenic stathmin expression in liver cancer

Background

Members of the karyopherin superfamily serve as nuclear transport receptors/adaptor proteins and provide exchange of macromolecules between the nucleo- and cytoplasm. Emerging evidence suggests a subset of karyopherins to be dysregulated in hepatocarcinogenesis including karyopherin-α2 (KPNA2). However, the functional and regulatory role of KPNA2 in liver cancer remains incompletely understood.

Methods

Quantitative proteomics (LC-MS/MS, ~ 1750 proteins in total) was used to study changes in global protein abundance upon siRNA-mediated KPNA2 knockdown in HCC cells. Functional and mechanistic analyses included colony formation and 2D migration assays, co-immunoprecipitation (CoIP), chromatin immunoprecipitation (ChIP), qRT-PCR, immmunblotting, and subcellular fractionation. In vitro results were correlated with data derived from a murine HCC model and HCC patient samples (3 cohorts, n > 600 in total).

Results

The proteomic approach revealed the pro-tumorigenic, microtubule (MT) interacting protein stathmin (STMN1) among the most downregulated proteins upon KPNA2 depletion in HCC cells. We further observed that KPNA2 knockdown leads to reduced tumor cell migration and colony formation of HCC cells, which could be phenocopied by direct knockdown of stathmin. As the underlying regulatory mechanism, we uncovered E2F1 and TFDP1 as transport substrates of KPNA2 being retained in the cytoplasm upon KPNA2 ablation, thereby resulting in reduced STMN1 expression. Finally, murine and human HCC data indicate significant correlations of STMN1 expression with E2F1/TFPD1 and with KPNA2 expression and their association with poor prognosis in HCC patients.

Conclusion

Our data suggest that KPNA2 regulates STMN1 by import of E2F1/TFDP1 and thereby provide a novel link between nuclear transport and MT-interacting proteins in HCC with functional and prognostic significance.

Pan-Cancer Landscape of Aberrant DNA Methylation across Human Tumors

The discovery of cancer-associated alterations has primarily focused on genetic variants. Nonetheless, altered epigenomes contribute to deregulate transcription and promote oncogenic pathways. Here, we designed an algorithmic approach (RESET) to identify aberrant DNA methylation and associated cis-transcriptional changes across >6,000 human tumors. Tumors exhibiting mutations of chromatin remodeling factors and Wnt signaling displayed DNA methylation instability, characterized by numerous hyper- and hypo-methylated loci. Most silenced and enhanced genes coalesced in specific pathways including apoptosis, DNA repair, and cell metabolism. Cancer-germline antigens (CG) were frequently epigenomically enhanced and their expression correlated with response to anti-PD-1, but not anti-CTLA4, in skin melanoma. Finally, we demonstrated the potential of our approach to explore DNA methylation changes in pediatric tumors, which frequently lack genetic drivers and exhibit epigenomic modifications. Our results provide a pan-cancer map of aberrant DNA methylation to inform functional and therapeutic studies.

Effects of bariatric surgery on DNA methylation in adults: a systematic review and meta-analysis

BACKGROUND

DNA methylation is an epigenetic mechanism through which environmental factors, including obesity, influence health. Obesity is a major modifiable risk factor for many common diseases, including cardiovascular diseases and cancer. Obesity-induced metabolic stress and inflammation are key mechanisms that affect disease risk and that may result from changes in methylation of metabolic and inflammatory genes.

OBJECTIVES

This review aims to report the effects of weight loss induced by bariatric surgery (BS) on DNA methylation in adults with obesity focusing on changes in metabolic and inflammatory genes.

METHODS

A systematic review was performed using MEDLINE, EMBASE, and Scopus, to identify studies in adult humans that reported DNA methylation after BS.

RESULTS

Of 15,996 screened titles, 15 intervention studies were identified, all of which reported significantly lower body mass index postsurgery. DNA methylation was assessed in 5 different tissues (blood = 7 studies, adipose tissues = 4, skeletal muscle = 2, liver, and spermatozoa). Twelve studies reported significant changes in DNA methylation after BS. Meta-analysis showed that BS increased methylation of PDK4 loci in skeletal muscle and blood in 2 studies, while the effects of BS on IL6 methylation levels in blood were inconsistent. BS had no overall effect on LINE1 or PPARGC1 methylation.

CONCLUSION

The current evidence supports the reversibility of DNA methylation at specific loci in response to BS-induced weight loss. These changes are consistent with improved metabolic and inflammatory profiles of patients after BS. However, the evidence regarding the effects of BS on DNA methylation in humans is limited and inconsistent, which makes it difficult to combine and compare data across studies.

Long Non-Coding RNAs (lncRNAs) Tumor-Suppressive Role of lncRNA on Chromosome 8p12 (TSLNC8) Inhibits Tumor Metastasis and Promotes Apoptosis by Regulating Interleukin 6 (IL-6)/Signal Transducer and Activator of Transcription 3 (STAT3)/Hypoxia-Inducible Factor 1-alpha (HIF-1α) Signaling Pathway in Non-Small Cell Lung Cancer

BACKGROUND Long non-coding RNAs (lncRNAs) exert various functions in human cancers. However, the biological functions of lncRNAs in non-small cell lung cancer (NSCLC) are unknown. In the present study we investigated the tumor-suppressive role of lncRNA on chromosome 8p12 (TSLNC8) in the pathogenesis and progression of NSCLC. MATERIAL AND METHODS qRT-PCR was carried out to evaluate the expression of TSLNC8 in lung cancer cell lines. The effects of TSLNC8 on A549 cells proliferation, migration, and invasion were analyzed using CCK-8 assay, wound healing assay, Transwell assay, and Western blot analysis. We used flow cytometry to assess cell apoptosis, and cell autophagy was assessed by Western blot analysis and immunofluorescence staining. Levels of proteins in the IL-6/STAT3/HIF-1alpha pathway were measured by Western blot analysis. RESULTS The results revealed that TSLNC8 was significantly downregulated in lung cancer cells compared to normal bronchial epithelial cells. Further experiments showed that overexpression of TSLNC8 in A549 cells significantly inhibited proliferation in a time-dependent manner and promoted cell apoptosis. We found that TSLNC8 overexpression suppressed cell migration and invasion, and upregulation of TSLNC8 regulated the protein levels of Beclin-1, p62, ATG14, and LC3-II and inhibited the IL-6/STAT3/HIF-1alpha signaling pathway. CONCLUSIONS lncRNA TSLNC8 remarkably inhibited the proliferation and migration and accelerated apoptosis of lung cancer cells by targeting the IL-6/STAT3/HIF-1alpha signaling pathway. TSLNC8 may be a potential therapeutic target for the diagnosis and treatment of NSCLC.

Unravelling the Diagnostic Dilemma: A MicroRNA Panel of Circulating MiR-16 and MiR-877 as A Diagnostic Classifier for Distal Bile Duct Tumors

Accurate diagnosis of pancreatic head lesions remains challenging as no minimally invasive biomarkers are available to discriminate distal cholangiocarcinoma (CCA) from pancreatic ductal adenocarcinoma (PDAC). The aim of this study is to identify specific circulating microRNAs (miRNAs) to diagnose distal CCA. In the discovery phase, PCR profiling of 752 miRNAs was performed on fourteen patients with distal CCA and age- and sex-matched healthy controls. Candidate miRNAs were selected for evaluation and validation by RT-qPCR in an independent cohort of distal CCA (N = 24), healthy controls (N = 32), benign diseases (N = 20), and PDAC (N = 24). The optimal diagnostic combination of miRNAs was determined by multivariate logistic regression analysis and evaluated by ROC curves with AUC values. The discovery phase revealed 19 significantly dysregulated miRNAs, of which six were validated in the evaluation phase. The validation phase confirmed downregulated miR-16 in patients with distal CCA compared to benign disease or PDAC (P = 0.048 and P = 0.012), while miR-877 was significantly upregulated (P = 0.003 and P = 0.006). This two-miRNA panel was validated as a CCA-specific profile, discriminating distal CCA from benign disease (AUC = 0.90) and from PDAC (AUC = 0.88). In conclusion, the present study identified a two-miRNA panel of downregulated miR-16 and upregulated miR-877 with promising capability to diagnose patients with distal CCA.

Down-regulation of argininosuccinate lyase induces hepatoma cell apoptosis through activating Bax signaling pathway

Argininosuccinate lyase (ASL) plays an important role in the hepatic urea cycle, and can catalyze the reversible reaction of argininosuccinate to arginine and fumarate. However, the function of ASL in hepatocellular carcinoma (HCC) is not fully understood. In this study, we found that ASL expression was frequently upregulated in HCC tissues and HCC cell lines. Knock down of ASL inhibited cell proliferation and induced apoptosis in HCC cells. Mechanistic studies revealed the BCL2-associated X protein (Bax) signaling pathway which determines cancer cell apoptosis was regulated by ASL. Moreover, the depletion of Bax restored the inhibition of cell growth and reduced apoptosis initiated by ASL silencing. Together, the study demonstrated that ASL regulated HCC cell growth and apoptosis by modulating Bax signaling. Thus, the therapeutic targeting of ASL may offer options for HCC treatment.

Levels of Cytokines in Serum Associate With Development of Hepatocellular Carcinoma in Patients With HCV Infection Treated With Direct-Acting Antivirals

Concern has arisen about the development of hepatocellular carcinoma (HCC) in patients with hepatitis C virus (HCV) infection treated with direct-acting antivirals (DAAs). To identify patients at risk for HCC, we evaluated serum levels of immune mediators before, during, and after DAA treatment of HCV infection. Our study included 13 patients who developed HCC within 18 months after treatment (3 with HCC recurrence and 10 with new HCC) and 10 patients who did not develop HCC (controls), within at least 24 months of treatment (median, 26 months). We identified a set of 12 immune mediators (cytokines, growth factors, and apoptosis markers) whose levels were significantly higher in serum before DAA treatment of patients who eventually developed de novo HCC compared with controls. A panel of 9 cytokines, measured in serum before treatment (MIG, IL22, TRAIL, APRIL, VEGF, IL3, TWEAK, SCF, IL21), identified patients who developed de novo HCC with an area under the receiver operating characteristic curve value higher than 0.8. Further analyses of changes in levels of inflammatory cytokines during DAA treatment also provides important information about HCV-induced carcinogenesis and the effects of DAAs.

Long noncoding RNA TSLNC8 is a tumor suppressor that inactivates the interleukin-6/STAT3 signaling pathway

Long noncoding RNAs can serve as oncogenes or tumor suppressors in human cancer; however, their biological functions and underlying mechanism in hepatocarcinogenesis are largely unknown. Here, we report a novel tumor suppressor long noncoding RNA on chromosome 8p12 (termed TSLNC8) that is frequently deleted and down-regulated in hepatocellular carcinoma (HCC) tissues. The loss of TSLNC8 is highly associated with the malignant features of HCC and serves as a prognostic indicator for HCC patients. TSLNC8 significantly suppresses the proliferation and metastasis of HCC cells in vitro and in vivo. TSLNC8 exerts its tumor suppressive activity by competitively interacting with transketolase and signal transducer and activator of transcription 3 (STAT3) and modulating the STAT3-Tyr705 and STAT3-Ser727 phosphorylation levels and STAT3 transcriptional activity, thus resulting in inactivation of the interleukin-6-STAT3 signaling pathway in HCC cells.

CONCLUSION

TSLNC8 is a promising prognostic predictor for patients with HCC, and the TSLNC8-transketolase-STAT3 axis is a potential therapeutic target for HCC treatment. (Hepatology 2018;67:171-187).

Low BIN3 Expression is an Independent Predictor of Unfavorable Survival in Patients With Primary Colorectal Cancer

This study aimed to explore the mechanisms of bridging integrator-3 dysregulation, its prognostic value, and related signaling pathways in colorectal cancer . Bioinformatic analysis was performed based on the data from The Cancer Genome Atlas–colorectal cancer and Human Protein Atlas. Colorectal cancer cell lines, LoVo and HT29 cells, were used as in vitro cell model to assess the effect of demethylation on bridging integrator-3 expression. Results showed that bridging integrator-3 was downregulated in colorectal cancer tissues compared to normal colon and rectum tissues. Heatmap of bridging integrator-3 messenger RNA expression, exon expression, and DNA methylation indicated a negative correlation between bridging integrator-3 expression and methylation of some CpG sites within the coding sequence. Demethylation treatment significantly increased bridging integrator-3 expression in LoVo and HT29 cells. Low bridging integrator-3 messenger RNA and exon expression were associated with significantly worse overall survival (P = .015 and .013, respectively). Multivariate analysis confirmed that low bridging integrator-3 messenger RNA expression was an independent prognostic factor of unfavorable overall survival (Hazard Ratio (HR) = 1.596, 95% confidence interval: 1.024-2.486; P = .039). High bridging integrator-3 DNA methylation was also associated with significantly worse overall survival (P = .013). Kyoto Encyclopedia of Genes and Genomes analysis indicated that the genes correlated with bridging integrator-3 (absolute Pearson r ≥ 0.3, n = 121) were enriched in sphingolipid signaling pathway, natural killer cell-mediated cytotoxicity, p53 signaling pathway, and apoptosis. Based on these findings, we infer that DNA hypermethylation might be an important mechanism of suppressed bridging integrator-3 expression in colorectal cancer . Its low expression is an independent predictor of unfavorable survival in patients with primary colorectal cancer . Bridging integrator-3 might act as a tumor suppressor via modulating natural killer cell-mediated cytotoxicity, p53 signaling pathway, and apoptosis.

Vinexin family (SORBS) proteins play different roles in stiffness-sensing and contractile force generation

Vinexin, c-Cbl associated protein (CAP) and Arg-binding protein 2 (ArgBP2) constitute an adaptor protein family called the vinexin (SORBS) family that is targeted to focal adhesions (FAs). Although numerous studies have focused on each of the SORBS proteins and partially elucidated their involvement in mechanotransduction, a comparative analysis of their function has not been well addressed. Here, we established mouse embryonic fibroblasts that individually expressed SORBS proteins and analysed their functions in an identical cell context. Both vinexin-α and CAP co-localized with vinculin at FAs and promoted the appearance of vinculin-rich FAs, whereas ArgBP2 co-localized with α-actinin at the proximal end of FAs and punctate structures on actin stress fibers (SFs), and induced paxillin-rich FAs. Furthermore, both vinexin-α and CAP contributed to extracellular matrix stiffness-dependent vinculin behaviors, while ArgBP2 stabilized α-actinin on SFs and enhanced intracellular contractile forces. These results demonstrate the differential roles of SORBS proteins in mechanotransduction.

Peri-tumor associated fibroblasts promote intrahepatic metastasis of hepatocellular carcinoma by recruiting cancer stem cells

Fibroblasts have been reported to play an important role in hepatocellular carcinoma (HCC). However, the role of fibroblasts have not been fully understood. Conditioned medium collected from human peri-tumor tissue-derived fibroblasts (CM-pTAFs) showed high metastasis ability than human HCC tissues-derived fibroblasts (CM-TAFs). To determine what component was secreted from fibroblasts, we used Bio-Plex analysis system and compared the factors secreted from CM-pTAFs and CM-TAFs, found a series of up-regulated cytokines in the CM-pTAFs, including IL-6, CCL2, CXCL1, CXCL8, SCGF-β, HGF and VEGF. Pretreatment of IL-6 inhibitor Tocilizumab could inhibit metastasis the HCC cell treated with CM-pTAFs in vitro and in vivo. The expression of CCR2 and CXCR1 were up-regulated after CM-pTAFs treatment in HCC cell line SMMC-7721. Flow cytometric analysis experiment showed that most CCR2 or CXCR1 positive cells were also EpCAM positive. In vitro studies also showed that CM-pTAFs could increase stemness of SMMC-7721. In addition, neutralization of SCGF-β and HGF could significantly reduce metastasis and viability of cancer stem cells treated with CM-pTAFs. Taken together, these results indicated that the peri-tumor tissues derived fibroblasts may promote development of HCC by recruiting cancer stem cells and maintaining their stemness characteristic.