The tumor suppressor Zinc finger protein 471 suppresses breast cancer growth and metastasis through inhibiting AKT and Wnt/β-catenin signaling

Suppression of N-Glycosylation of Zinc Finger Protein 471 Affects Proliferation, Invasion, and Docetaxel Sensitivity of Tongue Squamous Cell Carcinoma via Regulation of c-Myc

Zinc finger protein 471 (ZNF471) is a member of the Krüppel-related domain zinc finger protein family, and has recently attracted attention because of its anti-cancer effects. N-glycosylation regulates expression and functions of the protein. This study aimed to investigate the effects of ZNF471 N-glycosylation on the proliferation, invasion, and docetaxel sensitivity of tongue squamous cell carcinoma (TSCC). It analyzed the expression, function, and prognostic significance of ZNF471 in TSCC using bioinformatics techniques such as gene differential expression analysis, univariate Cox regression analysis, functional enrichment analysis, and gene set enrichment analysis. Using site-specific mutagenesis, this study generated three mutant sites for ZNF471 N-glycosylation to determine the effect of N-glycosylation on ZNF471 protein levels and function. Quantitative real-time PCR, Western blot analysis, and immunohistochemistry tests confirmed the down-regulation of ZNF471 expression in TSCC. Low expression of ZNF471 is associated with poor prognosis of patients with TSCC. Overexpression of ZNF471 in vitro retarded the proliferation of TSCC cells and suppressed cell invasion and migration ability. Asparagine 358 was identified as a N-glycosylation site of ZNF471. Suppressing N-glycosylation of ZNF471 enhanced the protein stability and promoted the translocation of protein to the cell nucleus. ZNF471 binding to c-Myc gene promoter suppressed oncogene c-Myc expression, thereby playing the anti-cancer effect and enhancing TSCC sensitivity to docetaxel. In all, N-glycosylation of ZNF471 affects the proliferation, invasion, and docetaxel sensitivity of TSCC via regulation of c-Myc.

ZNF862 induces cytostasis and apoptosis via the p21-RB1 and Bcl-xL-Caspase 3 signaling pathways in human gingival fibroblasts

OBJECTIVE

This study investigates the effects of ZNF862 on the proliferation and apoptosis of human gingival fibroblasts and their related mechanisms.

BACKGROUND

As a major transcription factor family, zinc finger proteins (ZFPs) regulate cell differentiation, growth, and apoptosis through their conserved zinc finger motifs, which allow high flexibility and specificity in gene regulation. In our previous study, ZNF862 mutation was associated with hereditary gingival fibromatosis. Nevertheless, little is known about the biological function of ZNF862. Therefore, this study was aimed to reveal intracellular localization of ZNF862, the influence of ZNF862 on the growth and apoptosis of human gingival fibroblasts (HGFs) and its potential related mechanisms.

METHODS

Immunohistochemistry, immunofluorescence staining, and western blotting were performed to determine the intracellular localization of ZNF862 in HGFs. HGFs were divided into three groups: ZNF862 overexpression group, ZNF862 interference group, and the empty vector control group. Then, the effects of ZNF862 on cell proliferation, migration, cell cycle, and apoptosis were evaluated. qRT-PCR and western blotting were performed to further explore the mechanism related to the proliferation and apoptosis of HGFs.

RESULTS

ZNF862 was found to be localized in the cytoplasm of HGFs. In vitro experiments revealed that ZNF862 overexpression inhibited HGFs proliferation and migration, induced cell cycle arrest at the G0/G1-phase and apoptosis. Whereas, ZNF862 knockdown promoted HGFs proliferation and migration, accelerated the transition from the G0/G1 phase into the S and G2/M phase and inhibited cell apoptosis. Mechanistically, the effects of ZNF862 on HGFs proliferation and apoptosis were noted to be dependent on inhibiting the cyclin-dependent kinase inhibitor 1A (p21)-retinoblastoma 1 (RB1) signaling pathway and enhancing the B-cell lymphoma-extra-large (Bcl-xL)-Caspase 3 signaling pathway.

CONCLUSION

Our results for the first time reveal that ZNF862 is localized in the cytoplasm of HGFs. ZNF862 can inhibit the proliferation of HGFs by inhibiting the p21-RB1 signaling pathway, and it also promotes the apoptosis of HGFs by enhancing the Bcl-xL-Caspase 3 signaling pathway.

Cell specification and functional interactions in the pig blastocyst inferred from single-cell transcriptomics and uterine fluids proteomics

The embryonic development of the pig comprises a long in utero pre- and peri-implantation development, which dramatically differs from mice and humans. During this peri-implantation period, a complex series of paracrine signals establishes an intimate dialogue between the embryo and the uterus. To better understand the biology of the pig blastocyst during this period, we generated a large dataset of single-cell RNAseq from early and hatched blastocysts, spheroid and ovoid conceptus and proteomic datasets from corresponding uterine fluids. Our results confirm the molecular specificity and functionality of the three main cell populations. We also discovered two previously unknown subpopulations of the trophectoderm, one characterised by the expression of LRP2, which could represent progenitor cells, and the other, expressing pro-apoptotic markers, which could correspond to the Rauber's layer. Our work provides new insights into the biology of these populations, their reciprocal functional interactions, and the molecular dialogue with the maternal uterine environment.

Pancreatic Neuroendocrine Tumors: Signaling Pathways and Epigenetic Regulation

Pancreatic neuroendocrine tumors (PNETs) are characterized by dysregulated signaling pathways that are crucial for tumor formation and progression. The efficacy of traditional therapies is limited, particularly in the treatment of PNETs at an advanced stage. Epigenetic alterations profoundly impact the activity of signaling pathways in cancer development, offering potential opportunities for drug development. There is currently a lack of extensive research on epigenetic regulation in PNETs. To fill this gap, we first summarize major signaling events that are involved in PNET development. Then, we discuss the epigenetic regulation of these signaling pathways in the context of both PNETs and commonly occurring-and therefore more extensively studied-malignancies. Finally, we will offer a perspective on the future research direction of the PNET epigenome and its potential applications in patient care.

ZNF471 Interacts with BANP to Reduce Tumour Malignancy by Inactivating PI3K/AKT/mTOR Signalling but is Frequently Silenced by Aberrant Promoter Methylation in Renal Cell Carcinoma

Background: Renal cell carcinoma (RCC) is one of the most common malignant tumours of the urinary system. However, the aetiology and pathogenesis of RCC remain unclear. The C2H2 zinc finger protein (ZNF) family is the largest transcriptional regulatory factor family found in mammals, and Krüppel-associated box domain-containing zinc finger proteins (KRAB-ZFPs) constitute the largest subfamily of the C2H2 zinc finger protein family and play an important role in the occurrence and development of tumours. The aim of this study was to explore the role of abnormal methylation of ZNF471 in the development of renal carcinoma. Methods: In this study, we first used the TCGA and EWAS Data Hub databases to analyse the expression and methylation levels of ZNF471 in renal carcinoma tissues and adjacent normal tissues. Second, we collected samples of renal cancer and adjacent normal tissues at Peking University First Hospital to investigate the expression and methylation level of ZNF471 in renal cancer tissues and the relationships between these levels and the clinicopathological features and prognosis of patients with renal cancer. Next, we investigated the effects of ZNF471 on the proliferation, metastasis, cell cycle progression, and apoptosis of renal cell carcinoma cells by cell biology experiments. Finally, we elucidated the underlying molecular mechanisms of ZNF471 in renal cell carcinoma by transcriptome sequencing, bioinformatics analysis and molecular biology experiments. Results: The expression of ZNF471 in renal carcinoma tissues and cell lines was significantly lower than that in adjacent normal tissues and cell lines due to abnormal promoter CpG methylation. Furthermore, the expression of ZNF471 in renal carcinoma tissues was negatively correlated with tumour stage and grade in patients with renal carcinoma. The results of the cell biology experiments showed that ZNF471 could significantly inhibit the proliferation, migration and cell cycle progression of renal cell carcinoma cells and promote apoptosis in these cells. In addition, ZNF471 could interact with BANP and suppress the malignant phenotype of RCC by inactivating the PI3K/AKT/mTOR signalling pathway. Conclusions: As an important tumour suppressor, ZNF471 can interact with BANP in renal cancer cells and inhibit the activation of the PI3K/AKT/mTOR signalling pathway, thereby inhibiting the occurrence and development of renal cancer.

CXXC finger protein 1 (CFP1) bridges the reshaping of genomic H3K4me3 signature to the advancement of lung adenocarcinoma

Histone H3 lysine 4 trimethylation (H3K4me3) is a canonical chromatin modification associated with active gene transcription, playing a pivotal role in regulating various cellular functions. Components of the H3K4me3 methyltransferase complex, known as the proteins associated with SET1 (COMPASS), have been implicated in exerting cancer-protective or cancer-inhibitory effects through inducive H3K4me3 modification. However, the role of the indispensable non-catalytic component of COMPASS CXXC-type zinc finger protein 1 (CFP1) in malignant progression remains unclear. We have unveiled that CFP1 promote lung adenocarcinoma (LUAD) cell proliferation, migration, and invasion while impairing cell apoptosis through in vitro and in vivo models. In addition, high CFP1 expression was identified as emerged as an adverse prognostic indicator across multiple public and in-house LUAD datasets. Notably, CFP1 deficiency led to dual effects on cancer cell transcriptome including extensive inactivation of cancer-promoting as well as activation of cancer repressors. Combining this with the chromatin immunoprecipitation sequencing (ChIP-seq) analysis, we showed that CFP1 ablation reshaped the genomic H3K4me3 distribution signature, with prominent effects on TGF-β and WNT signaling pathways. Collectively, our study proposes that CFP1 mediates tumorigenesis by genomic histone methylation reprogramming, offering insights for future investigations into epigenetic modifications in cancer progression and potential therapeutic advancements.

The role of zinc finger proteins in malignant tumors

Zinc finger proteins (ZNFs) are the largest family of transcriptional factors in mammalian cells. Recently, their role in the development, progression, and metastasis of malignant tumors via regulating gene transcription and translation processes has become evident. Besides, their possible involvement in drug resistance has also been found, indicating that ZNFs have the potential to become new biological markers and therapeutic targets. In this review, we summarize the oncogenic and suppressive roles of various ZNFs in malignant tumors, including lung, breast, liver, gastric, colorectal, pancreatic, and other cancers, highlighting their role as prognostic markers, and hopefully provide new ideas for the treatment of malignant tumors in the future.

Clinical significance of expression level of ZNF471 in gastric cancer

BACKGROUND

As a tumor suppressor gene, zinc finger protein 471 (ZNF471) has an essential role in tumor occurrence and development. Due to promoter hypermethylation, it can be underexpressed or silenced in gastric cancer (GC) cell lines. In this study, we investigated relationships between clinical characteristics and ZNF471 expression levels in tissues of patients with GC.

METHODS

We used immunohistochemistry (IHC) to detect ZNF471 expression in paraffin tissue specimens, and quantitative real-time PCR (qRT-PCR) and western blot (WB) analysis to measure expression levels of ZNF471 in fresh tissue specimens. We analyzed relationships between ZNF471 expression levels and characteristics, such as tumor size, gender, age, TNM stage, and lymph node metastasis.

RESULTS

Immunohistochemistry revealed the expression of ZNF471 protein from paraffin blocks of GC tissues was significantly lower than that of adjacent tissues. Expression levels of ZNF471 mRNA and protein in fresh GC tissues were markedly lower than those in adjacent tissues and in normal gastric mucosal tissues from healthy subjects. ZNF471 expression was significantly correlated with tumor size, lymph node metastasis, and TNM stage (all P<0.05). There were no significant associations with gender, age, distant metastasis, or pathologic type. Expression of ZNF471 mRNA and protein was not significantly different between adjacent tissues of patients with GC and normal gastric mucosal tissue from healthy subjects.

CONCLUSION

ZNF471 functions as a tumor suppressor during the pathogenesis of GC. Thus, it is a promising biomarker for diagnosis and therapy of GC.

ZNF677 inhibits oral squamous cell carcinoma growth and tumor stemness by regulating FOXO3a

Oral squamous cell carcinoma (OSCC) is a common cancer with an increasing incidence worldwide. Zinc-finger proteins 677 (ZNF677) is involved in the progression and methylation of various cancers, but its role and mechanism in OSCC remain indeterminate. The expression of ZNF677 was analyzed by online database and immunohistochemistry, while the methylation level of ZNF677 was determined by the methylation-specific PCR. The role and mechanism of ZNF677 in the tumor cell growth, migration, invasion and stemness were addressed by cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU) incorporation, Transwell, wound-healing, sphere‑formation, and western blot assays. In addition, its function was also investigated in a xenografted mice model. The results showed that ZNF677 was lowly expressed in OSCC with a hypermethylation level, which predicted poor overall survival in patients with HNSC. Upregulation of ZNF677 reduced the cell viability, Edu positive cells, numbers of invasion cells, the migration ability, numbers of spheres formation and the expression of proliferation, migration and stemness related proteins in CAL-27 and SCC25 cells. Mechanically, the relative levels of p-AKT/AKT were decreased and the levels of p-FOXO3a/FOXO3a were increased in both cells overexpressed with ZNF677, which were reversed by the SC79 treatment. Moreover, interference of FOXO3a recovered the suppressive effects of ZNF677 overexpression on cell proliferation, migration, invasion and stemness of OSCC cells. Furthermore, overexpression of ZNF677 reduced the tumor volume and weight, and the relative protein level of p-AKT/AKT with an increased level of p-FOXO3a/FOXO3a, and improved pathological symptoms in vivo. Collectively, ZNF677 suppressed OSCC cells growth, migration, invasion and stemness through inhibiting AKT/FOXO3a pathway.

Biological functions and molecular interactions of Wnt/β-catenin in breast cancer: Revisiting signaling networks

Changes in lifestyle such as physical activity and eating habits have been one of the main reasons for development of various diseases in modern world, especially cancer. However, role of genetic factors in initiation of cancer cannot be ignored and Wnt/β-catenin signaling is such factor that can affect tumor progression. Breast tumor is the most malignant tumor in females and it causes high mortality and morbidity around the world. The survival and prognosis of patients are not still desirable, although there have been advances in introducing new kinds of therapies and diagnosis. The present review provides an update of Wnt/β-catenin function in breast cancer malignancy. The upregulation of Wnt is commonly observed during progression of breast tumor and confirms that tumor cells are dependent on this pathway Wnt/β-catenin induction prevents apoptosis that is of importance for mediating drug resistance. Furthermore, Wnt/β-catenin signaling induces DNA damage repair in ameliorating radio-resistance. Wnt/β-catenin enhances proliferation and metastasis of breast tumor. Wnt/β-catenin induces EMT and elevates MMP expression. Furthermore, Wnt/β-catenin participates in tumor microenvironment remodeling and due to its tumor-promoting factor, drugs for its suppression have been developed. Different kinds of upstream mediators Wnt/β-catenin signaling in breast cancer have been recognized that their targeting is a therapeutic approach. Finally, Wnt/β-catenin can be considered as a biomarker in clinical trials.

Novel RNA N6-methyladenosine regulator related signature for predicting clinical and immunological characteristics in breast cancer

BACKGROUND

Epigenetic mechanismshave been reported to involve in shaping tumor immune microenvironment (TME). However, the role of RNA N6-methyladenosine (m6A) modification in breast cancerhas not been fully explored.

METHODS

Based on m6A modification and TME infiltration characteristics of 2249 breast cancer patients, we comprehensively correlated m6A modification with immune landscapeby screeningcandidate genes, function analysis and constructing m6Asignatures. Principal component analysis was used to establish the m6Ascore. Both LASSO and Cox regression analyses were used to evaluate its prognostic value.Functional assays and immunohistochemistry were used to evaluate the expression of m6A regulators and immune cell infiltration.

RESULTS

Based on the dysregulated expression of m6A, three distinct clusters were identified that displayed diverse types of tumour-associated TME cell infiltration in breast cancer.Gene signatures, stromal activity, and clinical prognosis were assessed by the m6Ascore. m6Ascore could function as a biomarker for predicting the therapeutic response to targeted therapy and immunotherapy.The dysregulated expression of m6Aregulators mediated the immune cell infiltration in the TME.

CONCLUSION

Basedonthestudy,weidentified the signature and potential mechanism of m6AmodificationsthatmodifyTME cell infiltration. Thus, targeting m6A regulators may provide a promisingmethodoftreatingBRCA.

Integrated Clinical and Prognostic Analysis of the m6A RNA Methylation Regulator YTHDF3 in Pan-Cancer and its Correlation with Cancer Cell Proliferation

Background: N6-methyladenosine (m⁶A) is the most abundant and extensive chemical modification of mammalian RNA molecules. Although numerous studies have investigated m⁶A methylation-related genes, to the best of our knowledge, none have examined the expression patterns of YTH N6-methyladenosine RNA binding protein 3 (YTHDF3) across cancers. Methods: Using various publicly available datasets, we searched for a potential carcinogenic role of YTHDF3 in 33 tumor types. Furthermore, the clinicopathological parameters, clinical prognostic value, enrichment analysis, mutations, microsatellite instability (MSI), tumor mutation burden (TMB), levels of infiltrating cells, and related immune checkpoint genes were included. Finally, we performed a validation analysis using existing clinical samples and proliferation-related functional experiments. Results: YTHDF3 is highly expressed in most cancer types and associated with patient prognosis in certain tumors. The ROC analysis suggested that YTHDF3 has high diagnostic value in 13 types of cancer. Furthermore, we found that the genes associated with YTHDF3 were enriched for translation initiation and mRNA metabolic processes. The results of the GSEA enrichment suggest that YTHDF3 may be associated with different pathways in cells in various tumor types. We further analyzed the correlations between YTHDF3 expression and MSI, TMB, and immune checkpoint genes. YTHDF3 also possibly exerts important antitumor immunotherapy effects. Additionally, the results of the immune analysis using TIMER showed that high YTHDF3 expression levels in pan-cancer tissues were related to an immunosuppressive microenvironment. Finally, we experimentally demonstrated that both overexpression and downregulation of YTHDF3 can affect cancer cell proliferation rates. Conclusion: YTHDF3 is a promising biomarker for cancer diagnosis. This study provides the first comprehensive pan-cancer report on YTHDF3 and increases our understanding of its oncogenic role in different tumors.

Salivary DNA methylation markers for cancer of oral cavity

PURPOSE: Aberrant DNA methylation plays a crucial role in oral carcinogenesis. Our previous study demonstrated hypermethylation of DAPK1, LRPPRC, RAB6C, and ZNF471 promoters in patients with tongue squamous cell carcinoma compared with normal samples. Methylation profiling using salivary DNA is considered a non-invasive alternative to tissue samples. Hence, the present study tested the DNA methylation status of these four promoters as indicators of oral cancer progression. METHODS: We performed the bisulfite-based targeted next-generation sequencing of four candidate genes in saliva and tissue DNA from normal, premalignant, and squamous cell carcinoma subjects. The clinicopathological association, diagnostic, and prognostic utility of aberrant DNA methylation were evaluated using the TCGA-HNSCC dataset. Using the Xgboost algorithm and logistic regression, CpG sites were prioritized, and Receiver Operating Characteristic was generated. By Log-rank test and Kaplan-Meier (KM) curves, an association between methylation and overall survival (OS), disease-free interval (DFI), and progression-free interval (PFI) were computed. RESULTS: We identified all four genes as significantly hypermethylation in premalignant and malignant samples compared with normal samples. The methylation levels were comparable between saliva and tissue samples with an r-value of 0.6297 to 0.8023 and 0.7823 to 0.9419 between premalignant tissue vs. saliva and OC vs. saliva, respectively. We identified an inverse correlation between DAPK1, LRPPRC, RAB6C, and ZNF471 promoter methylation with its expression. A classifier of 8 differentially methylated CpG sites belonging to DAPK1, RAB6C, and ZNF471 promoters was constructed, showing an AUC of 0.984 to differentiate tumors from normal samples. The differential methylation status of DAPK1, LRPPRC, and ZNF71 promoters was prognostically important. Abnormal expression of all four genes was associated with immune infiltration. CONCLUSIONS: Thus, methylation analysis of these candidate CpG sites from saliva can be helpful as a non-invasive tool for the clinical management of OC.

Investigation of the effects of downregulation of jumping translocation breakpoint (JTB) protein expression in MCF7 cells for potential use as a biomarker in breast cancer

MCF7 is a commonly used luminal type A non-invasive/poor-invasive human breast cancer cell line that does not usually migrate or invade compared with MDA-MB-231 highly metastatic cells, which emphasize an invasive and migratory behavior. Under special conditions, MCF7 cells might acquire invasive features. The aberration in expression and biological functions of the jumping translocation breackpoint (JTB) protein is associated with malignant transformation of cells, based on mitochondrial dysfunction, inhibition of tumor suppressive function of TGF-β, and involvement in cancer cell cycle. To investigate new putative functions of JTB by cellular proteomics, we analyzed the biological processes and pathways that are associated with the JTB protein downregulation. The results demonstrated that MCF7 cell line developed a more "aggressive" phenotype and behavior. Most of the proteins that were overexpressed in this experiment promoted the actin cytoskeleton reorganization that is involved in growth and metastatic dissemination of cancer cells. Some of these proteins are involved in the epithelial-mesenchymal transition (EMT) process (ACTBL2, TUBA4A, MYH14, CSPG5, PKM, UGDH, HSP90AA2, and MIF), in correlation with the energy metabolism reprogramming (PKM, UGDH), stress-response (HSP10, HSP70A1A, HSP90AA2), and immune and inflammatory response (MIF and ERp57-TAPBP). Almost all upregulated proteins in JTB downregulated condition promote viability, motility, proliferation, invasion, survival into a hostile microenvironment, metabolic reprogramming, and escaping of tumor cells from host immune control, leading to a more invasive phenotype for MCF7 cell line. Due to their downregulated condition, four proteins, such as CREBZF, KMT2B, SELENOS and CACNA1I are also involved in maintenance of the invasive phenotype of cancer cells, promoting cell proliferation, migration, invasion and tumorigenesis. Other downregulated proteins, such as MAZ, PLEKHG2, ENO1, TPI2, TOR2A, and CNNM1, may promote suppression of cancer cell growth, invasion, EMT, tumorigenic abilities, interacting with glucose and lipid metabolism, disrupting nuclear envelope stability, or suppressing apoptosis and developing anti-angiogenetic activities. Therefore, the main biological processes and pathways that may increase the tumorigenic potential of the MCF7 cells in JTB downregulated condition are related to the actin cytoskeleton organization, EMT, mitotic cell cycle, glycolysis and fatty acid metabolism, inflammatory response and macrophage activation, chemotaxis and migration, cellular response to stress condition (oxidative stress and hypoxia), transcription control, histone modification and ion transport.

Disruption of ZNF334 promotes triple-negative breast carcinoma malignancy through the SFRP1/ Wnt/β-catenin signaling axis

Zinc-finger proteins (ZNFs) constitute the largest transcription factor family in the human genome. The family functions in many important biological processes involved in tumorigenesis. In our research, we identified ZNF334 as a novel tumor suppressor of triple-negative breast cancer (TNBC). ZNF334 expression was usually reduced in breast cancerv (BrCa) tissues and TNBC cell lines MDA-MB-231 (MB231) and YCCB1. We observed that promoter hypermethylation of ZNF334 was common in BrCa cell lines and tissues, which was likely responsible for its reduced expression. Ectopic expression of ZNF334 in TNBC cell lines MB231 and YCCB1 could suppress their growth and metastatic capacity both in vitro and in vivo, and as well induce cell cycle arrest at S phase and cell apoptosis. Moreover, re-expression of ZNF334 in TNBC cell lines could rescue Epithelial-Mesenchymal Transition (EMT) process and restrain stemness, due to up-regulation of SFRP1, which is an antagonist of Wnt/β-catenin signaling. In conclusion, we verified that ZNF334 had a suppressive function of TNBC cell lines by targeting the SFRP1/Wnt/β-catenin signaling axis, which might have the potentials to become a new biomarker for diagnosis and treatment of TNBC patients.

KRAB-ZFPs and cancer stem cells identity

Studies on carcinogenesis continue to provide new information about different disease-related processes. Among others, much research has focused on the involvement of cancer stem cells (CSCs) in tumor initiation and progression. Studying the similarities and differences between CSCs and physiological stem cells (SCs) allows for a better understanding of cancer biology. Recently, it was shown that stem cell identity is partially governed by the Krϋppel-associated box domain zinc finger proteins (KRAB-ZFPs), the biggest family of transcription regulators. Several KRAB-ZFP factors exert a known effect in tumor cells, acting as tumor suppressor genes (TSGs) or oncogenes, yet their role in CSCs is still poorly characterized. Here, we review recent studies regarding the influence of KRAB-ZFPs and their cofactor protein TRIM28 on CSCs phenotype, stemness features, migration and invasion potential, metastasis, and expression of parental markers.

Epigenome-Wide Association Study of Prostate Cancer in African Americans Identifies DNA Methylation Biomarkers for Aggressive Disease

DNA methylation plays important roles in prostate cancer (PCa) development and progression. African American men have higher incidence and mortality rates of PCa than other racial groups in U.S. The goal of this study was to identify differentially methylated CpG sites and genes between clinically defined aggressive and nonaggressive PCa in African Americans. We performed genome-wide DNA methylation profiling in leukocyte DNA from 280 African American PCa patients using Illumina MethylationEPIC array that contains about 860K CpG sties. There was a slight increase of overall methylation level (mean β value) with the increasing Gleason scores (GS = 6, GS = 7, GS ≥ 8, P for trend = 0.002). There were 78 differentially methylated CpG sites with P < 10-4 and 9 sites with P < 10-5 in the trend test. We also found 77 differentially methylated regions/genes (DMRs), including 10 homeobox genes and six zinc finger protein genes. A gene ontology (GO) molecular pathway enrichment analysis of these 77 DMRs found that the main enriched pathway was DNA-binding transcriptional factor activity. A few representative DMRs include HOXD8, SOX11, ZNF-471, and ZNF-577. Our study suggests that leukocyte DNA methylation may be valuable biomarkers for aggressive PCa and the identified differentially methylated genes provide biological insights into the modulation of immune response by aggressive PCa.

Abnormally elevated ubiquilin‑1 expression in breast cancer regulates metastasis and stemness via AKT signaling

Ubiquilin-1 (UBQLN1) is an essential factor for the maintenance of proteostasis in cells. It is important for the regulation of different protein degradation mechanisms, including the ubiquitin-proteasome system, autophagy and endoplasmic reticulum-associated protein degradation pathways. However, the role of UBQLN1 in cancer progression remains largely unknown. In the present study, the expression, functions and molecular mechanisms of UBQLN1 in breast cancer tissue samples and cell lines were explored. Immunohistochemical and bioinformatics analyses revealed that UBQLN1 expression was significantly upregulated in breast cancer tissues and cell lines. UBQLN1 expression in breast cancer was significantly associated with lymph node metastasis and TNM stage. Moreover, a high UBQLN1 expression was a predictor of an unfavorable survival in patients with breast cancer. In vitro, UBQLN1 silencing markedly inhibited cell migration and invasion, epithelial-to-mesenchymal transition (EMT) and MMP expression. UBQLN1 silencing attenuated the stem cell-like properties of breast cancer cells, including their mammosphere-forming abilities. UBQLN1 knockdown also enhanced breast cancer cell chemosensitivity to paclitaxel. The expression levels of the stem cell markers. Aldehyde dehydrogenase 1 (ALDH1), Oct-4 and Sox2 were significantly decreased in the cells in which UBQLN1 was silenced, whereas breast cancer stem cells exhibited an increased expression of UBQLN1. Mechanistically, UBQLN1 knockdown inhibited the activation of AKT signaling, as revealed by the increased PTEN expression and the decreased expression of phosphorylated AKT in cells in which UBQLN1 was silenced. On the whole, the present study demonstrates that UBQLN1 is aberrantly upregulated in breast cancer and predicts a poor prognosis. The silencing of UBQLN1 inhibited the invasion, EMT and stemness of breast cancer cells, possibly via AKT signaling.

The Identification of Zinc-Finger Protein 433 as a Possible Prognostic Biomarker for Clear-Cell Renal Cell Carcinoma

Clear-cell renal cell carcinoma (ccRCC) is the most common and aggressive form of all urological cancers, with poor prognosis and high mortality. At late stages, ccRCC is known to be mainly resistant to chemotherapy and radiotherapy. Therefore, it is urgent and necessary to identify biomarkers that can facilitate the early detection of ccRCC in patients. In this study, the levels of transcripts of ccRCC from The Cancer Genome Atlas (TCGA) dataset were used to identify prognostic biomarkers in this disease. Analyzing the data obtained indicated that the KRAB-ZNF protein is significantly suppressed in clear-cell carcinomas. Furthermore, ZNF433 is differentially expressed in ccRCC in a stage- and histological-grade-specific manner. In addition, ZNF433 expression was correlated with metastasis, with greater node involvement associated with lower ZNF433 expression (p < 0.01) and with a more unsatisfactory overall survival outcome (HR, 0.45; 95% CI, 0.33–0.6; p = 8.5 × 10⁻⁸). Since ccRCC is characterized by mutations in proteins that alter epigenetic modifications and /or chromatin remodeling, we examined the expression of ZNF433 transcripts in ccRCC with wildtype and mutated forms of BAP1, KDMC5, MTOR, PBRM1, SETD2, and VHL. Analysis revealed that ZNF433 expression was significantly reduced in ccRCC with mutations in the BAP1, SETD2, and KDM5C genes (p < 0.05). In addition, the ZNF433 promoter region was highly methylated, and hypermethylation was significantly associated with mRNA suppression (p < 2.2 × 10⁻¹⁶). In silico analysis of potential ZNF target genes found that the largest group of target genes are involved in cellular metabolic processes, which incidentally are particularly impaired in ccRCC. It was concluded from this study that gene expression of ZNF433 is associated with cancer progression and poorer prognosis, and that ZNF433 behaves in a manner that suggests that it is a prognostic marker and a possible tumor-suppressor gene in clear-cell renal cell carcinoma.

Acrid-release and bitter-downbearing therapy and banxia xiexin decoction regulate Wnt/β-catenin pathway, inhibit proliferation and invasion, and induce apoptosis in gastric cancer cells

OBJECTIVE

To explore the efficacy of the acrid-release and bitter-downbearing therapy and Banxia Xiexin Decoction (BXD) in treating gastric cancer (GC).

METHODS

BXD was decocted, and serum containing medicine was prepared from rats. The SNU-16 cells were cultured with different concentrations of BXD serum (25, 50, 100 μL/mL). Then, those were treated with BXD and Wnt/β-catenin pathway activator (LiCl) and divided into three groups: Control group, BXD group and BXD+LiCl group. Activation of the Wnt/β-catenin pathway was detected by immunofluorescence staining, qRT-PCR, and western blot. Cell activity, clone formation, invasion, metastasis and apoptosis in each group were examined by MTT, clone formation test, Transwell and flow cytometry. The oxidative stress measures in cells of each group were tested by an oxidative stress kit.

RESULTS

With increasing BXD concentration, the clonogenic ability of cells was inhibited. BXD can inhibit cell activity, clone formation, invasion and metastasis, promote oxidative stress, and induce apoptosis. It can also inhibit the activation of Wnt/β-catenin signaling pathway. A Wnt/β-catenin signaling pathway activator could partially inhibit the action of BXD.

CONCLUSION

BXD participates in GC treatment by inhibiting Wnt/β-catenin signaling pathway, thus inhibiting GC cell activity and clone formation, promoting oxidative stress, and inducing apoptosis.

KRAB-ZFP Transcriptional Regulators Acting as Oncogenes and Tumor Suppressors: An Overview

Krüppel-associated box zinc finger proteins (KRAB-ZFPs) constitute the largest family of transcriptional factors exerting co-repressor functions in mammalian cells. In general, KRAB-ZFPs have a dual structure. They may bind to specific DNA sequences via zinc finger motifs and recruit a repressive complex through the KRAB domain. Such a complex mediates histone deacetylation, trimethylation of histone 3 at lysine 9 (H3K9me3), and subsequent heterochromatization. Nevertheless, apart from their repressive role, KRAB-ZFPs may also co-activate gene transcription, likely through interaction with other factors implicated in transcriptional control. KRAB-ZFPs play essential roles in various biological processes, including development, imprinting, retroelement silencing, and carcinogenesis. Cancer cells possess multiple genomic, epigenomic, and transcriptomic aberrations. A growing number of data indicates that the expression of many KRAB-ZFPs is altered in several tumor types, in which they may act as oncogenes or tumor suppressors. Hereby, we review the available literature describing the oncogenic and suppressive roles of various KRAB-ZFPs in cancer. We focused on their association with the clinicopathological features and treatment response, as well as their influence on the cancer cell phenotype. Moreover, we summarized the identified upstream and downstream molecular mechanisms that may govern the functioning of KRAB-ZFPs in a cancer setting.

ZNF471 modulates EMT and functions as methylation regulated tumor suppressor with diagnostic and prognostic significance in cervical cancer

Cervical cancer (CC) is a leading cause of cancer-related death among women in developing countries. However, the underlying mechanisms and molecular targets for therapy remain to be fully understood. We investigated the epigenetic regulation, biological functions, and clinical utility of zinc-finger protein 471 (ZNF471) in CC. Analysis of cervical tissues and five independent public datasets of CC showed significant hypermethylation of the ZNF471 gene promoter. In CC cell lines, promoter DNA methylation was inversely correlated with ZNF471 expression. The sensitivity and specificity of the ZNF471 hypermethylation for squamous intraepithelial lesion (SIL) vs tumor and normal vs tumor was above 85% with AUC of 0.937. High methylation and low ZNF471 expression predicted poor overall and recurrence-free survival. We identified -686 to +114 bp as ZNF471 promoter, regulated by methylation using transient transfection and luciferase assays. The promoter CpG site methylation of ZNF471 was significantly different among cancer types and tumor grades. Gal4-based heterologous luciferase reporter gene assays revealed that ZNF471 acts as a transcriptional repressor. The retroviral mediated overexpression of ZNF471 in SiHa and CaSki cells inhibited growth, proliferation, cell migration, invasion; delayed cell cycle progression in vitro by increasing cell doubling time; and reduced tumor growth in vivo in nude mice. ZNF471 overexpression inhibited key members of epithelial-mesenchymal transition (EMT), Wnt, and PI3K-AKT signaling pathways. ZNF471 inhibited EMT by directly targeting vimentin as analyzed by bioinformatic analysis, ChIP-PCR, and western blotting. Thus, ZNF471 CpG specific promoter methylation may determine the prognosis of CC and could function as a potential tumor suppressor by targeting EMT signaling.