HSF1 and Sp1 regulate FUT4 gene expression and cell proliferation in breast cancer cells

RING induces cell cycle arrest and apoptosis in human breast cancer cells by regulating the HSF1/MT2A axis

It was reported that lowly expressed RING1 indicates poor prognosis in breast cancer (BC) patients, while the mechanism by which RING1 is involved in BC progression is not fully understood. Here, we found that RING1 was lowly expressed in BC tissues and cells than in normal mammary tissues and epithelial cells. Overexpression of RING1 suppressed the cell proliferative and colony formation abilities, and facilitated cell cycle arrest and cell apoptosis in BC cells (T47D and MCF-7 cells). Mechanistically, as an ubiquitin ligase, RING1 bound to HSF1 and induced its proteasome-dependent degradation. HSF1 could bind to the promoter region of MT2A to promote the transcriptional level of MT2A. While RING1 overexpression hindered the transcriptional activation of MT2A induced by HSF1. Moreover, ectopic expression of MT2A reversed the inhibitory effect of RING1 on cell proliferation and clonogenesis, and antagonized the promotion effect of RING1 on cell cycle arrest and apoptosis in BC cells. Additionally, T47D cells infected with or without lentivirus-mediated RING1 overexpression vector (LV-RING1) were injected subcutaneously into the right back of nude mice to evaluate tumorigenicity. And overexpression of RING1 impeded the growth of BC xenografts in mice. In conclusion, RING1 suppressed the transcriptional activation of MT2A induced by HSF1 by facilitating the ubiquitination degradation of HSF1, resulting in cell cycle arrest and apoptosis in BC cells.

Expression of Fucosyltransferase 4 (FUT4) mRNA Is Increased in Endometrium from Women with Endometriosis

Endometriosis is a common gynecological disorder defined as the presence of endometrial-like tissue (glands and stroma) outside the uterus. The etiopathogenesis of endometriosis is still poorly recognized. It is speculated that stage-specific embryonic antigen 1 (SSEA-1)-positive stem-like glandular epithelial cells may contribute to the development of the disease. The synthesis of SSEA-1 is mediated by fucosyltransferase 4 encoded by the FUT4 gene. Therefore, this study aimed to evaluate the specific expression of FUT4 mRNA in biopsies of the endometrium from women with and without endometriosis. FUT4 mRNA levels were examined in 49 women with laparoscopically confirmed endometriosis and 28 controls by means of quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The expression of FUT4 mRNA was significantly increased in the endometrium of patients with endometriosis when compared to the controls (p < 0.0001). Expression of FUT4 mRNA in the endometrium was correlated with the severity of endometriosis (rs = 0.5579, p < 0.0001); however, there were no differences in endometrial FUT4 mRNA expression when comparing endometriotic lesions from various locations. The discriminatory ability of FUT4 mRNA expression was evaluated by receiver-operating characteristics (ROC), which showed high statistical significance (AUC = 0.90, p < 0.0001), thus indicating that an increased level of endometrial FUT4 mRNA may serve as a specific marker for endometriosis.

The Multifaceted Role of HSF1 in Pathophysiology: Focus on Its Interplay with TG2

The cellular environment needs to be strongly regulated and the maintenance of protein homeostasis is crucial for cell function and survival. HSF1 is the main regulator of the heat shock response (HSR), the master pathway required to maintain proteostasis, as involved in the expression of the heat shock proteins (HSPs). HSF1 plays numerous physiological functions; however, the main role concerns the modulation of HSPs synthesis in response to stress. Alterations in HSF1 function impact protein homeostasis and are strongly linked to diseases, such as neurodegenerative disorders, metabolic diseases, and different types of cancers. In this context, type 2 Transglutaminase (TG2), a ubiquitous enzyme activated during stress condition has been shown to promote HSF1 activation. HSF1-TG2 axis regulates the HSR and its function is evolutionary conserved and implicated in pathological conditions. In this review, we discuss the role of HSF1 in the maintenance of proteostasis with regard to the HSF1-TG2 axis and we dissect the stress response pathways implicated in physiological and pathological conditions.

HSF1 as a Cancer Biomarker and Therapeutic Target

Heat shock factor 1 (HSF1) was discovered in 1984 as the master regulator of the heat shock response. In this classical role, HSF1 is activated following cellular stresses such as heat shock that ultimately lead to HSF1-mediated expression of heat shock proteins to protect the proteome and survive these acute stresses. However, it is now becoming clear that HSF1 also plays a significant role in several diseases, perhaps none more prominent than cancer. HSF1 appears to have a pleiotropic role in cancer by supporting multiple facets of malignancy including migration, invasion, proliferation, and cancer cell metabolism among others. Because of these functions, and others, of HSF1, it has been investigated as a biomarker for patient outcomes in multiple cancer types. HSF1 expression alone was predictive for patient outcomes in multiple cancer types but in other instances, markers for HSF1 activity were more predictive. Clearly, further work is needed to tease out which markers are most representative of the tumor promoting effects of HSF1. Additionally, there have been several attempts at developing small molecule inhibitors to reduce HSF1 activity. All of these HSF1 inhibitors are still in preclinical models but have shown varying levels of efficacy at suppressing tumor growth. The growth of research related to HSF1 in cancer has been enormous over the last decade with many new functions of HSF1 discovered along the way. In order for these discoveries to reach clinical impact, further development of HSF1 as a biomarker or therapeutic target needs to be continued.

Machine Learning Classifies Core and Outer Fucosylation of N-Glycoproteins Using Mass Spectrometry

Protein glycosylation is known to be involved in biological progresses such as cell recognition, growth, differentiation, and apoptosis. Fucosylation of glycoproteins plays an important role for structural stability and function of N-linked glycoproteins. Although many of biological and clinical studies of protein fucosylation by fucosyltransferases has been reported, structural classification of fucosylated N-glycoproteins such as core or outer isoforms remains a challenge. Here, we report for the first time the classification of N-glycopeptides as core- and outer-fucosylated types using tandem mass spectrometry (MS/MS) and machine learning algorithms such as the deep neural network (DNN) and support vector machine (SVM). Training and test sets of more than 800 MS/MS spectra of N-glycopeptides from the immunoglobulin gamma and alpha 1-acid-glycoprotein standards were selected for classification of the fucosylation types using supervised learning models. The best-performing model had an accuracy of more than 99% against manual characterization and area under the curve values greater than 0.99, which were calculated by probability scores from target and decoy datasets. Finally, this model was applied to classify fucosylated N-glycoproteins from human plasma. A total of 82N-glycopeptides, with 54 core-, 24 outer-, and 4 dual-fucosylation types derived from 54 glycoproteins, were commonly classified as the same type in both the DNN and SVM. Specifically, outer fucosylation was dominant in tri- and tetra-antennary N-glycopeptides, while core fucosylation was dominant in the mono-, bi-antennary and hybrid types of N-glycoproteins in human plasma. Thus, the machine learning methods can be combined with MS/MS to distinguish between different isoforms of fucosylated N-glycopeptides.

MiR-29b/Sp1/FUT4 axis modulates the malignancy of leukemia stem cells by regulating fucosylation via Wnt/β-catenin pathway in acute myeloid leukemia

BACKGROUND

Acute myeloid leukemia (AML) is initiated and maintained by a unique, small subset of leukemia stem cells (LSCs). LSCs are characterized by unrestricted self-renewal and contribute to the malignancy of leukemia. Aberrant protein fucosylation is associated with AML progression. However, it is still less understood that the miR-29b/Sp1/FUT4 crosstalk involved in the fucosylation-mediated LSCs malignancy in AML.

METHODS

AML cell lines were sorted by magnetic microbeads to obtain the CD34 + CD38- sub-population. The key biomarkers for LSCs were identified by flow cytometry. Fucosyltransferase genes were screened by qRT-PCR, and FUT4 was focused. Effect of FUT4 on LSCs malignancy was determined by CCK8 assay, sphere formation assay, immunofluorescence staining, apoptosis and in vivo xenografts experiments. The linkage of FUT4 promoter and Sp1 was confirmed by dual-luciferase reporter gene assay. ChIP-PCR assay was used to show the directly binding of Sp1 and FUT4 promoter. Activity of Wnt//β-catenin pathway was determined by western blot. Overall survival curves were diagrammed by Kaplan-Meier analysis.

RESULTS

Here, the expressional profiles of 11 fucosyltransferase genes were different comparing LSCs and non-LSCs of KG-1a and MOLM13 cells, whereas CD34 + CD38- cells exhibited higher expression of FUT4. Functionally, alteration of FUT4 in CD34 + CD38- cells modulated LSCs malignant behaviors both in vitro and in vivo. Transcriptional inhibitor actinomycin D (Act D) or translational inhibitor cycloheximide (CHX) prevented LSCs progression, and Sp1 was identified as the efficient regulator of FUT4 transcription. Moreover, miR-29b directly affected the binding of Sp1 and FUT4 promoter region, which further mediated LSCs proliferation, apoptosis and drug-resistance through fucosylated-CD44 via activation of Wnt/β-catenin pathway. Clinically, Sp1 and FUT4 were up-regulated and positively correlated with poor overall survival of AML patients.

CONCLUSION

These data indicated that miR-29b/Sp1/FUT4 axis promoted the malignant behaviors of LSCs by regulating fucosylated CD44 via Wnt/β-catenin pathway. Identifying LSCs surface markers and targeting LSCs were important for the development of potential therapies in AML.

Dual inhibition of MEK1/2 and AKT by binimetinib and MK2206 induces apoptosis of chronic lymphocytic leukemia cells under conditions that mimic the tumor microenvironment

Several key pathways mediate signaling via the B-cell receptor, including the mitogen-activated protein kinase-ERK1/2 pathway. However, inhibition of MEK1/2, a key component of the MAPK-ERK1/2 signaling cascade, results in paradoxical activation of AKT in chronic lymphocytic leukemia (CLL) cells. In the current study we demonstrate synergy between the MEK1/2 inhibitor binimetinib and the AKT inhibitor MK2206, which combined induce apoptosis of primary CLL cells and restrict the cell cycle progression and proliferation of the OSU-CLL cell line. The mechanisms of action of the drug combination involve dual inhibition of MAPK-ERK1/2 and AKT signaling and down-regulation of Mcl-1 expression. Collectively, these data suggest that dual inhibition of MEK1/2 and AKT may represent a therapeutic option for CLL, capable of overcoming the pro-survival effects of the lymph node and bone marrow microenvironments.

FUT4 is involved in PD-1-related immunosuppression and leads to worse survival in patients with operable lung adenocarcinoma

PURPOSE

As an important glycosyltransferase, fucosyltransferase IV (FUT4) is abnormally upregulated in different types of cancers, but its clinical role remains inexplicit. This work aimed to determine the predictive ability of FUT4 in lung adenocarcinoma (LUAD) after curative resection, as well as to explore the role of a possible FUT4 molecular mechanism on LUAD malignant behavior.

METHODS

A total of 273 LUAD patients after curative resection with complete clinicopathological and RNAseq data from The Cancer Genome Atlas (TCGA) cohort were collected. Correlation of FUT4 with overall survival (OS) was analyzed based on TCGA and further validated by online "Kaplan-Meier Plotter" database and IHC in 70 LUAD patients recruited in the First Hospital of China Medical University cohort. Multivariate Cox regression analysis and 1000 bootstrapping were performed to verify the predictive value of FUT4. Gene set enrichment assay (GSEA) was performed to investigate the biological characteristics. Correlation between PD-1 and FUT4 was analyzed based on TCGA cohort and validated by IHC on cohort from our hospital.

RESULTS

Increased FUT4 expression led to reduced overall survival (OS) of LUAD patients based on TCGA (p = 0.006 and 0.001 for dichotomous and trichotomous modeling, respectively) and externally validated in KMPLOTTER (p = 0.01) and by IHC based on cohort from our hospital (p = 0.005 and p = 0.019 for dichotomous and trichotomous modeling, respectively). FUT4 overexpression was an independent high risk factor for OS along with advanced pT stage and pTNM stage (p = 0.001, p = 0.037, and p < 0.001, respectively). GSEA revealed that FUT4 overexpression might correlate with shortened survival of LUAD patients by promoting cell proliferation via ERBB signaling, and suppressing immune response-related pathways. FUT4 expression positively correlated with PD-1 in TCGA (p = 0.026) and validated by IHC on cohort from our hospital (p = 0.029).

CONCLUSIONS

Increased FUT4 expression led to reduced OS in operable LUAD. FUT4 showed significant correlation with immune response and PD-1 expression.

Roles of heat shock factor 1 beyond the heat shock response

Various stress factors leading to protein damage induce the activation of an evolutionarily conserved cell protective mechanism, the heat shock response (HSR), to maintain protein homeostasis in virtually all eukaryotic cells. Heat shock factor 1 (HSF1) plays a central role in the HSR. HSF1 was initially known as a transcription factor that upregulates genes encoding heat shock proteins (HSPs), also called molecular chaperones, which assist in refolding or degrading injured intracellular proteins. However, recent accumulating evidence indicates multiple additional functions for HSF1 beyond the activation of HSPs. Here, we present a nearly comprehensive list of non-HSP-related target genes of HSF1 identified so far. Through controlling these targets, HSF1 acts in diverse stress-induced cellular processes and molecular mechanisms, including the endoplasmic reticulum unfolded protein response and ubiquitin-proteasome system, multidrug resistance, autophagy, apoptosis, immune response, cell growth arrest, differentiation underlying developmental diapause, chromatin remodelling, cancer development, and ageing. Hence, HSF1 emerges as a major orchestrator of cellular stress response pathways.

Lewis-antigen-containing ICAM-2/3 on Jurkat leukemia cells interact with DC-SIGN to regulate DC functions

Dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) is an important C-type lectin and plays a critical role in the recognition of pathogens and self-antigens. It has recently been shown that DC-SIGN directly interacts with acute T lymphoblastic leukemia cells. However, the mechanism regulating DC-SIGN-dependent DC association as well as related functions is still elusive. Here we showed that DC-SIGN preferentially bound to a set of malignant T lymphocytes, including Jurkat, CCRF-HSB2 and CCRF-CEM. ICAM-2/3 on Jurkat cells appeared to be the responsible ligands and the block of ICAM-2/3 dramatically impaired DC-SIGN association. We also found that ICAM-2/3 bear a considerable amount of Lewis X, Lewis Y and Lewis A residues, which are important for DC-SIGN recognition. Furthermore, transcriptome analysis revealed an upregulation of fucosyltransferase 4 (FUT4) in Jurkat cells and downregulating FUT4 limited DC-SIGN binding, indicating a previously unappreciated role of FUT4 in the control of Lewis antigens on malignant T lymphocytes. In addition, the presence of Jurkat cells impaired DC maturation and the block of DC-SIGN improved Jurkat cell-mediated effects on DC function and T cell differentiation. Together, we provide evidence that DC-SIGN orients DC association with acute T lymphoblastic leukemia cells and orchestrates DC functions.

Fucosylated Antigens in Cancer: An Alliance toward Tumor Progression, Metastasis, and Resistance to Chemotherapy

Aberrant glycosylation of tumor cells is recognized as a universal hallmark of cancer pathogenesis. Overexpression of fucosylated epitopes, such as type I (H1, Lewis^a, Lewis^b, and sialyl Lewis^a) and type II (H2, Lewis^x, Lewis^y, and sialyl Lewis^x) Lewis antigens, frequently occurs on the cancer cell surface and is mainly attributed to upregulated expression of pertinent fucosyltransferases (FUTs). Nevertheless, the impact of fucose-containing moieties on tumor cell biology is not fully elucidated yet. Here, we review the relevance of tumor-overexpressed FUTs and their respective synthesized Lewis determinants in critical aspects associated with cancer progression, such as increased cell survival and proliferation, tissue invasion and metastasis, epithelial to mesenchymal transition, epithelial and immune cell interaction, angiogenesis, multidrug resistance, and cancer stemness. Furthermore, we discuss the potential use of enhanced levels of fucosylation as glycan biomarkers for early prognosis, diagnosis, and disease monitoring in cancer patients.

miR-200b inhibits proliferation and metastasis of breast cancer by targeting fucosyltransferase IV and α1,3-fucosylated glycans

Aberrant protein fucosylation is associated with cancer malignancy. Fucosyltransferase IV (FUT4) is the key enzyme catalyzing the biosynthesis of α1,3-linkage fucosylated glycans carried by glycoproteins on the cell surface, such as the tumor-associated sugar antigen Lewis Y (LeY). An abnormal increase in the levels of FUT4 and LeY is observed in many cancers and correlated with cell proliferation and metastasis. Some microRNAs (miRNAs) are known to negatively regulate gene expression. FUT4 is an oncogenic glycogene, and thus it is important to identify the specific miRNA targeting FUT4. In current study, we first identified miR-200b as a specific miRNA that inhibited FUT4 expression. We found that miR-200b level was decreased, whereas that of FUT4 was increased in tissues and serum of breast cancer compared with that in the control by real-time PCR, western blotting and enzyme-linked immunosorbent assay. The alterations of miR-200b and FUT4 level were recovered after chemotherapy. The results also showed that miR-200b suppressed FUT4 expression and inhibited tumor growth and metastasis in MCF-7 and MDA-MB-231 breast cancer cells, as well as in the xenografted tumor tissues and metastatic lung tissues. miR-200b decreased the α1,3-fucosylation and LeY biosynthesis on epidermal growth factor receptor (EGFR), as well as inactivation of EGFR and downstream phosphoinositide-3 kinase/Akt signaling pathway. In conclusion, the study highlights that FUT4 could apply as a novel target for miR-200b that suppress the proliferation and metastasis of breast cancer cells by reducing α1,3-fucosylation and LeY biosynthesis of glycoproteins. miR-200b and FUT4 are potential diagnostic and therapeutic targets for breast cancer.

Ginsenoside Rg3 induces FUT4-mediated apoptosis in H. pylori CagA-treated gastric cancer cells by regulating SP1 and HSF1 expressions

Helicobacter pylori (H. pylori) cytotoxin associated antigen A (CagA) plays a significant role in the development of gastric cancer. Ginsenoside Rg3 is a herbal medicine which inhibits cell proliferation and induces apoptosis in various cancer cells. Fucosylation plays important roles in cancer biology as increased fucosylation levels of glycoproteins and glycolipids have been reported in many cancers. Fucosyltransferase IV (FUT4) is an essential enzyme, catalyzes the synthesis of LewisY oligosaccharides and is regulated by specificity protein 1 (SP1) and heat shock factor protein 1 (HSF1) transcription factors. Herein, we studied the mechanism action of Rg3 apoptosis induction in gastric cancer cells. We treated the gastric cancer cells with CagA followed by Rg3, and analyzed their ability to induce apoptosis by evaluating the role of FUT4 as well as SP1 and HSF1 expressions by Western blot, flow cytometry and ELISA. We found that Rg3 significantly induced apoptosis in CagA treated gastric cancer cells, as evidenced by nuclear staining of 4-6-diamidino-2-phenylindole (DAPI) and Annexin-V/PI double-labeling. In addition, Rg3 significantly increased the expression of pro-apoptotic proteins and triggered the activation of caspase-3, -8, and -9 and PARP. Moreover, Rg3-induced apoptotic mechanisms indicated that Rg3 inhibited FUT4 expression through SP1 upregulation and HSF1 downregulation. Hence, Rg3 therapy is an effective strategy for gastric cancer treatment. Furthermore SP1 and HSF1 may serve as potential diagnostic and therapeutic targets for gastric cancer.

Reconstruction of temporal activity of microRNAs from gene expression data in breast cancer cell line

Background

MicroRNAs (miRNAs) are small non-coding RNAs that regulate genes at the post-transcriptional level in spatiotemporal manner. Several miRNAs are identified as prognostic and diagnostic markers in many human cancers. Estimation of the temporal activities of the miRNAs is an important step in the way to understand the complex interactions of these important regulatory elements with transcription factors (TFs) and target genes (TGs). However, current research on miRNA activities excludes network dynamics from the studies, disregarding the important element of time in the regulatory network analysis.

Results

In the current study, we combined experimentally verified miRNA-TG interactions with breast cancer microarray TG expression data to identify key miRNAs and compute their temporal activity using network component analysis (NCA). The computed activities showed that miRNAs were regulated in a time dependent manner. Our results allowed constructing a synergistic network of miRNAs using the computed miRNA activities and their shared regulation of TGs. We further extended this network by incorporating miRNA-TG, miRNA-TF, TF-miRNA and TF-TG regulations in the context of breast cancer. Our integrated network identified several miRNAs known to be involved in breast cancer regulation and revealed several novel miRNAs. Our further analysis detected substantial involvement of the miRNAs miR-324, miR-93, miR-615 and miR-1 in breast cancer, which was not known previously. Next, combining our integrated networks with functional annotation of differentially expressed genes resulted in new sub-networks. These sub-networks allowed us to identify the key miRNAs and their interactions with TFs and TGs of several biological processes involved in breast cancer. The identified markers are validated for their potential as prognostic markers for breast cancer through survival analysis.

Conclusions

Our dynamical analysis of the miRNA interactions greatly helps to discover new network based markers, and is highly applicable (but not limited) to cancer research.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-2260-3) contains supplementary material, which is available to authorized users.

Multifaceted roles of HSF1 in cancer

Heat shock transcription factor 1 (HSF1) is the master regulator of the heat shock response. Accumulating evidence shows that HSF1 is overexpressed in a variety of human cancers, is associated with cancer aggressiveness, and could serve as an independent diagnostic or prognostic biomarker. In this review, we will provide an overview of the multifaceted roles of HSF1 in cancer, with a special focus on the four underlying molecular mechanisms involved. First, HSF1 regulates the expression of heat shock proteins (HSPs) including HSP90, HSP70, and HSP27. Second, HSF1 regulates cellular metabolism, including glycolysis and lipid metabolism. Third, HSF1 serves as a regulator of different signaling pathways, such as HuR-HIF-1, Slug, protein kinase C (PKC), nuclear factor-kappaB (NF-κB), PI3K-AKT-mTOR, and mitogen-activated protein kinase (MAPK) pathways. Finally, HSF1 regulates microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Overall, HSF1 plays many important roles in cancer via regulating cell proliferation, anti-apoptosis, epithelial-mesenchymal transition (EMT), migration, invasion, and metastasis and may be a potential therapeutic target for human cancers.

Ginsenoside Rg3 suppresses FUT4 expression through inhibiting NF-κB/p65 signaling pathway to promote melanoma cell death

Abnormal glycosylation is catalyzed by the specific glycosyltransferases and correlates with tumor cell apoptosis. Increased fucosyltransferase IV (FUT4) is seen in many types of cancer, and manipulating FUT4 expression through specific signaling pathway inhibits cell growth and induces apoptosis. NF-κB is known playing a vital role to control cell growth and apoptosis. Ginsenoside Rg3 is an herbal medicine with strong antitumor activity through inhibiting tumor growth and promoting tumor cell death. However, whether Rg3-induced inhibition on tumor development involves reduced NF-κB signaling and FUT4 expression remains unknown. In the present study, we found that Rg3 suppressed FUT4 expression by abrogating the binding of NF-κB to FUT4 promoter through inhibiting the expression of signaling molecules of NF-κB pathway, reducing NF-κB DNA binding activity and NF-κB transcription activity. NF-κB inhibitor (Bay 11-7082) or knocking down p65 expression by p65 siRNA also led to a significant decreased FUT4 expression. In addition, Rg3 induced apoptosis by activating both extrinsic and intrinsic apoptotic pathways. Moreover, in a xenograft mouse model, Rg3 downregulated FUT4 and NF-κB/p65 expression and suppressed melanoma cell growth and induced apoptosis without any noticeable toxicity. In conclusion, Rg3 induces tumor cell apoptosis correlated with its inhibitory effect on NF-κB signaling pathway-mediated FUT4 expression. Results suggest Rg3 might be a novel therapy agent for melanoma treatment.

Baicalin promotes embryo adhesion and implantation by upregulating fucosyltransferase IV (FUT4) via Wnt/beta-catenin signaling pathway

Glycosylation plays a significant role in determining the receptivity of the uterine endometrium to embryo. Fucosyltransferase IV (FUT4) is expressed stage-specifically in the uterine endometrium of mammalians, and considered as a marker of the endometrial receptivity. Baicalin, a monomer of flavonoids, is known to have functions in improving reproduction. However, the mechanism by which baicalin regulates the expression of FUT4 in embryo-endometrium adhesion remains unclear. Our results showed that baicalin significantly increased FUT4 mRNA and protein expression levels both in human endometrial cells and mouse endometrial tissue, and consistently elevated embryo adhesion rate during implantation in vitro and embryonic implantation competence in pregnant mouse. This study suggests that baicalin facilitates endometrial reproduction via elevating FUT4 expression through Wnt/β-catenin signaling pathway.

Fucosyltransferase IV (FUT4) as an effective biomarker for the diagnosis of breast cancer

Specific enzymes are involved in altered glycosylation of cancer. Fucosyltransferase IV (FUT4) is associated with the proliferation and metastasis of breast cancer. The application of FUT4 assay in the serum has not been reported yet. Here, the expression level of FUT4 in the breast cancer patient's tissues (n=60) was analyzed by immunohistochemistry (IHC) and the secreted FUT4 in blood serum samples (n=225) was detected by enzyme-linked immunosorbent assay (ELISA). Using low metastatic MCF-7 and high metastatic MDA-MB-231 breast cancer cell lines, FUT4 expression was also detected by reverse transcription-polymerase chain reaction (RT-PCR), Western blot and immunofluorescent staining. The conventional cancer biomarkers cancer antigen (CA15.3) and carcinoembryonic antigen (CEA) was analyzed by Elecsys-electrochemical immune assay (ECLIA) to compare specificity and sensitivity with that of FUT4. We have observed a significant high expression of FUT4 in breast cancer tissues and serums as compared to the normal tissues (P<0.01) and control serums (P<0.05). FUT4 expression was increased in MDA-MB-231 cells vs. that in MCF-7 cells. Furthermore, the results of receiver operating characteristic (ROC) analysis was shown, area under curve of FUT4 (AUC=0.784) was higher than that of CA15.3 (AUC=0.468) and CEA (AUC=0.563). The relation analysis is indicated FUT4 is significantly correlated with CA15.3 (r=0.234, P<0.05) and there is no significant correlation with CEA. In conclusion, this study suggests that FUT4 can serve as novel biomarker in the diagnosis and prognosis of breast cancer.

JMJD2A-dependent silencing of Sp1 in advanced breast cancer promotes metastasis by downregulation of DIRAS3

Specificity protein 1(Sp1) is a ubiquitous transcription factor and is highly expressed in breast cancer. However, its expression pattern and role in breast cancer progression remain unclear. The purpose of this study is to examine the expression pattern of Sp1 and determine its role in breast cancer progression. Immunohistochemistry (IHC) was performed on breast cancer tissues to reveal the expression pattern of Sp1. Spearman rank correlation was used for clinical statistics. Gene and protein expressions were monitored by IHC analysis, quantitative polymerase chain reaction, and Western blot. Wound-healing and Transwell assays were conducted to assess the role of Sp1 in breast cancer. Co-immunoprecipitation, deletion mutagenesis, chromatin immunoprecipitation, and dual luciferase reporter gene assays were used for investigation of the regulatory network. Sp1 expression was downregulated in late stage breast cancer and in highly invasive breast cancer cell lines. Expression of Sp1 was negatively correlated with TNM staging (P = 0.002) and metastasis status (P = 0.023). Overexpression of Sp1 inhibited breast cancer cell migratory and invasive abilities, whereas knockdown of GTP-binding RAS-like 3 (DIRAS3, also known as ARHI, NOEY2) attenuated the inhibitory effects. Moreover, re-expression of DIRAS3 abolished Sp1 knockdown-mediated cell migration and invasion. Jumonji domain containing 2A (JMJD2A) inhibited Sp1 autoregulation and explains Sp1 expression pattern in breast cancer. Sp1 negatively regulated breast cancer metastasis by transcriptional activation of DIRAS3. Inhibition of Sp1 autoregulation by JMJD2A contributed to Sp1 expression pattern in breast cancer. Our findings provided evidence that targeted therapy against Sp1 might be useful in early stage breast cancer. However, in late stages, development of Sp1 activator may be more promising for breast cancer treatments.