Zeppo1 is a novel metastasis promoter that represses E-cadherin expression and regulates p120-catenin isoform expression and localization

Insights into the pleiotropic roles of ZNF703 in cancer

Zinc finger proteins (ZNFs) belong to the NET/NLZ protein family. In physiological functions, ZNF703 play significant roles in embryonic development, especially in the nervous system. As an transcription factors with zinc finger domains, abnormal regulation of the ZNF703 protein is associated with enhanced proliferation, invasion, and metastasis as well as drug resistance in many tumors, although mechanisms of action vary depending on the specific tumor microenvironment. ZNF703 lacks a nuclear localization sequence despite its function requiring nuclear DNA binding. The purpose of this review is to summarize the architecture of ZNF703, its roles in tumorigenesis, and tumor progression, as well as future oncology therapeutic prospects, which have implications for understanding tumor susceptibility and progression.

ZNF703 mRNA-Targeting Antisense Oligonucleotide Blocks Cell Proliferation and Induces Apoptosis in Breast Cancer Cell Lines

The luminal B molecular subtype of breast cancers (BC) accounts for more than a third of BCs and is associated with aggressive clinical behavior and poor prognosis. The use of endocrine therapy in BC treatment has significantly contributed to the decrease in the number of deaths in recent years. However, most BC patients with prolonged exposure to estrogen receptor (ER) selective modulators such as tamoxifen develop resistance and become non-responsive over time. Recent studies have implicated overexpression of the ZNF703 gene in BC resistance to endocrine drugs, thereby highlighting ZNF703 inhibition as an attractive modality in BC treatment, especially luminal B BCs. However, there is no known inhibitor of ZNF703 due to its nuclear association and non-enzymatic activity. Here, we have developed an antisense oligonucleotide (ASO) against ZNF703 mRNA and shown that it downregulates ZNF703 protein expression. ZNF703 inhibition decreased cell proliferation and induced apoptosis. Combined with cisplatin, the anti-cancer effects of ZNF703-ASO9 were improved. Moreover, our work shows that ASO technology may be used to increase the number of targetable cancer genes.

Characteristics and Prognosis of 8p11.23-Amplified Squamous Lung Carcinomas

BACKGROUND

Copy number alterations are common genetic lesions in cancer. In squamous non-small cell lung carcinomas, the most common copy-number-altered loci are at chromosomes 3q26-27 and 8p11.23. The genes that may be drivers in squamous lung cancers with 8p11.23 amplifications are unclear.

METHODS

Data pertaining to copy number alterations, mRNA expression and protein expression of genes located in the 8p11.23 amplified region were extracted from various sources including The Cancer Genome Atlas, the Human Protein Atlas and the Kaplan Meier Plotter. Genomic data were analyzed using the cBioportal platform. Survival analysis of cases with amplifications compared to nonamplified cases was performed using the Kaplan Meier Plotter platform.

RESULTS

The 8p11.23 locus is amplified in 11.5% to 17.7% of squamous lung carcinomas. The most frequently amplified genes include NSD3, FGFR1 and LETM2. Only some of the amplified genes present concomitant overexpression at the mRNA level. These include NSD3, PLPP5, DDHD2, LSM1 and ASH2L, while other genes display lower levels of correlation, and still, some genes in the locus show no mRNA overexpression compared with copy-neutral samples. The protein products of most locus genes are expressed in squamous lung cancers. No significant difference in overall survival in 8p11.23-amplified squamous cell lung cancers versus nonamplified cancers is observed. In addition, there is no adverse effect of mRNA overexpression for relapse-free survival of any of the amplified genes.

CONCLUSION

Several genes that are part of the commonly amplified locus 8p11.23 in squamous lung carcinomas are putative oncogenic candidates. A subset of genes of the centromeric part of the locus, which is amplified more commonly than the telomeric part, show high concomitant mRNA expression.

MiXcan: a framework for cell-type-aware transcriptome-wide association studies with an application to breast cancer

Human bulk tissue samples comprise multiple cell types with diverse roles in disease etiology. Conventional transcriptome-wide association study approaches predict genetically regulated gene expression at the tissue level, without considering cell-type heterogeneity, and test associations of predicted tissue-level expression with disease. Here we develop MiXcan, a cell-type-aware transcriptome-wide association study approach that predicts cell-type-level expression, identifies disease-associated genes via combination of cell-type-level association signals for multiple cell types, and provides insight into the disease-critical cell type. As a proof of concept, we conducted cell-type-aware analyses of breast cancer in 58,648 women and identified 12 transcriptome-wide significant genes using MiXcan compared with only eight genes using conventional approaches. Importantly, MiXcan identified genes with distinct associations in mammary epithelial versus stromal cells, including three new breast cancer susceptibility genes. These findings demonstrate that cell-type-aware transcriptome-wide analyses can reveal new insights into the genetic and cellular etiology of breast cancer and other diseases.

CCND1 Amplification in Breast Cancer -associations With Proliferation, Histopathological Grade, Molecular Subtype and Prognosis

CCND1 is located on 11q13. Increased CCND1 copy number (CN) in breast cancer (BC) is associated with high histopathological grade, high proliferation, and Luminal B subtype. In this study of CCND1 in primary BCs and corresponding axillary lymph node metastases (LNM),we examine associations between CCND1 CN in primary BCs and proliferation status, molecular subtype, and prognosis. Furthermore, we studied associations between CCND1 CN and CNs of FGFR1 and ZNF703, both of which are located on 8p12. Fluorescence in situ hybridization probes for CCND1 and chromosome 11 centromere were used on tissue microarrays comprising 526 BCs and 123 LNM. We assessed associations between CCND1 CN and tumour characteristics using Pearson's χ2 test, and estimated cumulative risks of death from BC and hazard ratios in analysis of prognosis. We found CCND1 CN ≥ 4 < 6 in 45 (8.6%) tumours, and ≥ 6 in 42 (8.0%). CCND1 CN (≥ 6) was seen in all molecular subtypes, most frequently in Luminal B (HER2-) (20/126; 16%). Increased CCND1 CN was associated with high histopathological grade, high Ki-67, and high mitotic count, but not prognosis. CCND1 CN ≥ 6 was accompanied by CN increase of FGFR1 in 6/40 cases (15.0%) and ZNF703 in 5/38 cases (13.2%). Three cases showed CN increase of all three genes. High CCND1 CN was most frequent in Luminal B (HER2-) tumours. Good correlation between CCND1 CNs in BCs and LNM was observed. Despite associations between high CCND1 CN and aggressive tumour characteristics, the prognostic impact of CCND1 CN remains unresolved.

Regulation of Alternative Splicing during Epithelial-Mesenchymal Transition

Alternative splicing is an essential mechanism of gene regulation, giving rise to remarkable protein diversity in higher eukaryotes. Epithelial-mesenchymal transition (EMT) is a developmental process that plays an essential role in metazoan embryogenesis. Recent studies have revealed that alternative splicing serves as a fundamental layer of regulation that governs cells to undergo EMT. In this review, we summarize recent findings on the functional impact of alternative splicing in EMT and EMT-associated activities. We then discuss the regulatory mechanisms that control alternative splicing changes during EMT.

ZNF703 gene copy number and protein expression in breast cancer; associations with proliferation, prognosis and luminal subtypes

PURPOSE

Amplification of 8p12 is frequent in breast cancer and associated with poor prognosis in luminal subtypes. ZNF703 has been identified as the driver gene of proliferation in the A1 amplicon situated in 8p12. In this study, the aims were to investigate associations between ZNF703 copy number alterations and molecular subtypes, proliferation and prognosis, and using immunohistochemistry, examine associations between ZNF703 copy number and ZNF703 protein expression.

METHODS

Copy number alterations in 702 primary breast tumours and corresponding lymph node metastases were examined using fluorescence in situ hybridization with probes for ZNF703 and centromere 8. In addition, protein expression was studied in 869 tumours from the same cohort. Associations between copy number alterations and protein expression and tumour characteristics were assessed using Pearson chi square test. The prognostic impact of ZNF703 copy number increase and protein expression was assessed estimating cumulative incidence of breast cancer death and hazard ratios.

RESULTS

We found mean ZNF703 copy number ≥ 6 in 7% of tumours, most frequently in Luminal B subtypes. We found a positive association between increased copy number, and high proliferation, high histological grade, and poor prognosis. Luminal A tumours with high copy number had high histological grade and poor prognosis (borderline significant). We found positive nuclear staining in 76% of primary tumours. There was an association between copy number status and protein expression, but no association between protein expression and prognosis.

CONCLUSIONS

In breast cancer, high ZNF703 copy number is associated with increased proliferation, Luminal B subtypes and poor prognosis.

APC regulation of ESRP1 and p120-catenin isoforms in colorectal cancer cells

The adenomatous polyposis coli (APC) tumor suppressor protein is associated with the regulation of Wnt signaling; however, APC also controls other cellular processes including the regulation of cell adhesion and migration. The expression of full-length APC in SW480 colorectal cancer cells (SW480+APC) not only reduces Wnt signaling, but increases membrane E-cadherin and restores cell–cell adhesion. This report describes the effects of full-length, wild-type APC (fl-APC) on cell–cell adhesion genes and p120-catenin isoform switching in SW480 colon cancer cells: fl-APC increased the expression of genes implicated in cell–cell adhesion, whereas the expression of negative regulators of E-cadherin was decreased. Analysis of cell–cell adhesion-related proteins in SW480+APC cells revealed an increase in p120-catenin isoform 3A; similarly, depletion of APC altered the p120-catenin protein isoform profile. Expression of ESRP1 (epithelial splice regulatory protein 1) is increased in SW480+APC cells, and its depletion results in reversion to the p120-catenin isoform 1A phenotype and reduced cell–cell adhesion. The ESRP1 transcript is reduced in primary colorectal cancer, and its expression correlates with the level of APC. Pyrvinium pamoate, which inhibits Wnt signaling, promotes ESRP1 expression. We conclude that re-expression of APC restores the cell–cell adhesion gene and posttranscriptional regulatory programs leading to p120-catenin isoform switching and associated changes in cell–cell adhesion.

Amplification of 8p11.23 in cancers and the role of amplicon genes

Copy number alterations are widespread in cancer genomes and are part of the genomic instability underlying the pathogenesis of neoplastic diseases. Recurrent copy number alterations of specific chromosomal loci may result in gains of oncogenes or losses of tumor suppressor genes and become entrenched in the genomic framework of certain types of cancers. The locus at chromosome 8p11.23 presents recurrent amplifications most commonly in squamous lung carcinomas, breast cancers, squamous esophageal carcinomas, and urothelial carcinomas. Amplification is rare in other cancers. The amplified segment involves several described oncogenes that may promote cancer cell survival and proliferation, as well as less well characterized genes that could also contribute to neoplastic processes. Genes proposed to be "drivers" in 8p11.23 amplifications include ZNF703, FGFR1 and PLPP5. Additional genes in the locus that could be functionally important in neoplastic networks include co-chaperone BAG4, lysine methyltransferase NSD3, ASH2L, a member of another methyltransferase complex, MLL and the mRNA processing and translation regulators LSM1 and EIF4EBP1. In this paper, genes located in the amplified segment of 8p11.23 will be examined for their role in cancer and data arguing for their importance for cancers with the amplification will be presented.

CD93 negatively regulates astrogenesis in response to MMRN2 through the transcriptional repressor ZFP503 in the developing brain

Astrogenesis is repressed in the early embryonic period and occurs in the late embryonic period. A variety of external and internal signals contribute to the sequential differentiation of neural stem cells. Here, we discovered that immune-related CD93 plays a critical negative role in the regulation of astrogenesis in the mouse cerebral cortex. We show that CD93 expression is detected in neural stem cells and neurons but not in astrocytes and declines as differentiation proceeds. Cd93 knockout increases astrogenesis at the expense of neuron production during the late embryonic period. CD93 responds to the extracellular matrix protein Multimerin 2 (MMRN2) to trigger the repression of astrogenesis. Mechanistically, CD93 delivers signals to β-Catenin through a series of phosphorylation cascades, and then β-Catenin transduces these signals to the nucleus to activate Zfp503 transcription. The transcriptional repressor ZFP503 inhibits the transcription of glial fibrillary acidic protein (Gfap) by binding to the Gfap promoter with the assistance of Grg5. Furthermore, Cd93 knockout mice exhibit autism-like behaviors. Taken together, our results reveal that CD93 is a negative regulator of the onset of astrogenesis and provide insight into therapy for psychiatric disorders.

Zinc finger protein 703 induces EMT and sorafenib resistance in hepatocellular carcinoma by transactivating CLDN4 expression

Metastasis is one of the most common reasons of hepatocellular carcinoma (HCC) death; however, the molecular mechanism underlying HCC metastasis remains incompletely defined. Here we report a new function of Zinc Finger Protein 703 (ZNF703), a member of the NET/NlZ family of zinc finger transcription factors, in promoting hepatocellular carcinoma metastasis. We demonstrated that the overexpression of ZNF703 in human HCC tissue is correlated with tumor metastasis and recurrence, it is also related with the prognosis and survival rate of patients. ZNF703 overexpression promotes HCC progression in vitro and in vivo, whereas ZNF703 knockdown has the opposite effect. In addition, ZNF703 induces epithelialmesenchymal transition (EMT) via directly binding to the CLDN4 promoter and transactivating CLDN4 expression. Downregulation of CLDN4 can attenuate ZNF703-mediated HCC metastasis, whereas upregulation of CLDN4 can reverse the decreased metastasis induced by ZNF703 knockdown. Our data revealed that ZNF703 expression is correlated with CLDN4 level, the overexpression of both ZNF703 and CLDN4 are leaded to poorer prognosis of patients with HCC. Moreover, ZNF703 knockdown can enhance the sensitivity of HCC cell to sorafenib, whereas ZNF703 overexpression has the opposite effect. These results suggested that ZNF703 might be a potential target for cancer therapies and a candidate prognostic biomarker for predicting whether patients with HCC are befitting for sorafenib treatment.

Single-cell RNA sequencing reveals a heterogeneous response to Glucocorticoids in breast cancer cells

Steroid hormone receptors such as the Glucocorticoid Receptor (GR) mediate transcriptional responses to hormones and are frequently targeted in the treatment of human diseases. Experiments using bulk populations of cells have provided a detailed picture of the global transcriptional hormone response but are unable to interrogate cell-to-cell transcriptional heterogeneity. To examine the glucocorticoid response in individual cells, we performed single cell RNA sequencing (scRNAseq) in a human breast cancer cell line. The transcriptional response to hormone was robustly detected in individual cells and scRNAseq provided additional statistical power to identify over 100 GR-regulated genes that were not detected in bulk RNAseq. scRNAseq revealed striking cell-to-cell variability in the hormone response. On average, individual hormone-treated cells showed a response at only 30% of the total set of GR target genes. Understanding the basis of this heterogeneity will be critical for the development of more precise models of steroid hormone signaling.

YAP1 amplification as a prognostic factor of definitive chemoradiotherapy in nonsurgical esophageal squamous cell carcinoma

Background

Definitive chemoradiation therapy (dCRT) is the standard treatment for patients with nonsurgical esophageal squamous cell carcinoma (ESCC), yet patients have demonstrated great variations in their responses to dCRT and inevitably progressed following treatment.

Methods

To identify prognostic biomarkers, we performed targeted next‐generation sequencing of 416 cancer‐related genes on primary tumors from 47 nonsurgical ESCC patients prior to dCRT treatment. The association between genetic alterations and patients' local recurrence‐free survival (LRFS), progression‐free survival (PFS), and overall survival (OS) was analyzed.

Results

TP53 (78% of patients), NOTCH1 (32%), ARID1A (13%), FAT1 (13%), and CDKN2A (13%) were commonly mutated in ESCC patients, while gene amplifications frequently occurred in MCL1 (36%), FGF19 (34%), MYC (32%), CCND1 (27%), ZNF217 (15%), CDKN2A (13%), and YAP1 (11%). Univariate and multivariate analyses of clinical factors and genetic alterations indicated that sex is an independent prognostic factor, with males tending to have better LRFS (hazard ratio [HR], 0.25; 95%CI, 0.08‐0.77, P = .015) and progression‐free survival (PFS) (HR, 0.35; 95%CI, 0.13‐0.93, P = .030) following dCRT. Meanwhile, YAP1 amplification (n = 7) was an adverse prognostic factor, and patients with this alteration demonstrated a tendency toward worse outcomes with shorter LRFS (HR, 4.06; 95%CI, 1.26‐13.14, P = .019) and OS (HR, 2.78; 95%CI, 0.95‐8.17, P = .062). In a subgroup analysis, while sex and M‐stage were controlled, a much stronger negative effect of YAP1 amplification vs wild‐type in LRFS was observed (log‐rank P = .0067).

Conclusion

The results suggested that YAP1 amplification is a potentially useful biomarker for predicting treatment outcomes and identifying patients with a high risk of relapse who should be closely monitored.

Silencing of zinc finger protein 703 inhibits medullary thyroid carcinoma cell proliferation in vitro and in vivo

Zinc finger protein 703 (ZNF703) is a new member of the zinc finger protein family of transcription factors that plays an important role during embryogenesis in metazoans. The overexpression of ZNF703 contributes to tumorigenesis and progression of a number of malignancies by activating the Akt/mammalian target of rapamycin (mTOR) signaling pathway. This pathway is activated in medullary thyroid cancer (MTC), but its mechanism of action is not yet fully understood. The aim of the present study was to examine the role of ZNF703 and its association with Akt/mTOR activation in MTC. The present study used the phosphorylation of Akt1 protein at serine 473 (pAkt⁴⁷³) as an indicator of signaling activation. Immunohistochemistry (IHC) staining and western blot analyses were performed in order to examine the expression of ZNF703 in 34 cases of MTC and 12 cases of corresponding normal thyroid tissues. ZNF703 expression in MTC was significantly higher compared with the corresponding normal thyroid tissues (P<0.05). Furthermore, expression of ZNF703 was associated with tumor size, lymph node metastasis and advanced stage of disease. IHC also demonstrated that the level of ZNF703 was positively correlated with p-Akt⁴⁷³ in the 34 cases of MTC. The human MTC cell line TT was selected for further investigation as TT cells exhibit Akt/mTOR activation. The biological effects of silencing ZNF703 in TT cells on proliferation and apoptosis, both in vitro and in vivo were investigated in the present study. ZNF703 silencing inhibited the proliferation of TT cells in vitro and inhibited xenograft tumor growth in vivo. These effects were accompanied by the substantial decrease of pAkt⁴⁷³ and the induction of p53 protein. These results demonstrate that ZNF703 may play a relevant role in MTC due to its association with the Akt/mTOR signaling pathway.

Levisticum Officinale Extract Triggers Apoptosis and Down-Regulates ZNF703 Gene Expression in Breast Cancer Cell Lines

BACKGROUND

Studies have shown that zinc finger protein 703 (ZNF703) is overexpressed in breast cancer. Levisticum (L.) officinale is a herbal plant with proven medical characteristics in traditional medicine. The purpose of the present study was to evaluate the effect of hydroalcoholic extract of L. officinale (HELO) on both estrogen receptor-positive (ER+) and -negative (ER-) cell lines (MCF-7 and MDA-MB-468, respectively).

METHODS

The anti-proliferative and apoptotic activities of HELO were investigated on both cell lines using MTT and flow-cytometry methods. Real-time PCR was employed to determinate the changes in mRNA expression of the ZNF703 gene.

RESULTS

The 50% maximal inhibitory concentrations (IC50s) of HELO on ER+ and ER- cells were 200 and 150 µg/mL after 48 h-treatment. Statistically significant increases in both early and late apoptosis rates were seen in exposed cell lines. ZNF703 expression was less from 4 to 24 h HELO treatment than in untreated cells, and ZNF703 expression was higher in the more invasive MDA-MB-468 cells than in the less invasive MCF-7 cells. Our results demonstrated that HELO induces apoptosis and decreases cell growth in both cell lines.

CONCLUSION

Our data suggest that HELO alters the mRNA levels of ZNF703 gene while inducing apoptotic cell death in breast cancer-derived cell lines. The use of ZNF703 suppression can be considered as a beneficial target in breast cancer research.

Znf703 is a novel RA target in the neural plate border

Znf703 is an RAR- and Wnt-inducible transcription factor that exhibits a complex expression pattern in the developing embryo: Znf703 mRNA is found in the early circumblastoporal ring, then later throughout the neural plate and its border, and subsequently in the mid/hindbrain and somites. We show that Znf703 has a different and separable function in early mesoderm versus neural crest and placode development. Independent of its early knockdown phenotype on Gdf3 and Wnt8, Znf703 disrupts patterning of distinct neural crest migratory streams normally delineated by Sox10, Twist, and Foxd3 and inhibits otocyst formation and otic expression of Sox10 and Eya1. Furthermore, Znf703 promotes massive overgrowth of SOX2+ cells, disrupting the SoxB1 balance at the neural plate border. Despite prominent expression in other neural plate border-derived cranial and sensory domains, Znf703 is selectively absent from the otocyst, suggesting that Znf703 must be specifically cleared or down-regulated for proper otic development. We show that mutation of the putative Groucho-repression domain does not ameliorate Znf703 effects on mesoderm, neural crest, and placodes. We instead provide evidence that Znf703 requires the Buttonhead domain for transcriptional repression.

Differential expression of p120-catenin 1 and 3 isoforms in epithelial tissues

P120 catenin (p120) is a non-redundant master regulatory protein of cadherin-based cell-cell junctions, intracellular signaling, and tissue homeostasis and repair. Alternative splicing can generate p120 isoforms 1 and 3 (p120-1 and p120-3), which are implicated in non-overlapping functions by differential expression regulation and unique interactions in different cell types, with often predominant expression of p120-1 in mesenchymal cells, and p120-3 generally prevalent in epithelial cells. However, the lack of specific p120-3 protein detection has precluded analysis of their relative abundance in tissues. Here, we have developed a p120-3 isoform-specific antibody and analyzed the p120-3 localization relative to p120-1 in human tissues. p120-3 but not p120-1 is highly expressed in cell-cell junctions of simple gastrointestinal epithelia such as colon and stomach, and the acini of salivary glands and the pancreas. Conversely, the basal layer of the epidermis and hair follicles expressed p120-1 with reduced p120-3, whereas most other epithelia co-expressed p120-3 and p120-1, including bronchial epithelia and mammary luminal epithelial cells. These data provide an inventory of tissue-specific p120 isoform expression and suggest a link between p120 isoform expression and epithelial differentiation.

RARγ is required for mesodermal gene expression prior to gastrulation in Xenopus

The developing vertebrate embryo is exquisitely sensitive to retinoic acid (RA) concentration, particularly during anteroposterior patterning. In contrast to Nodal and Wnt signaling, RA was not previously considered to be an instructive signal in mesoderm formation during gastrulation. Here, we show in Xenopus that RARγ is indispensable for the expression of early mesoderm markers and is, therefore, an obligatory factor in mesodermal competence and/or maintenance. We identified several novel targets upregulated by RA receptor signaling in the early gastrula that are expressed in the circumblastoporal ring and linked to mesodermal development. Despite overlapping expression patterns of the genes encoding the RA-synthesizing enzyme Aldh1a2 and the RA-degrading enzyme Cyp26a1, RARγ1 functions as a transcriptional activator in early mesoderm development, suggesting that RA ligand is available to the embryo earlier than previously appreciated. RARγ1 is required for cellular adhesion, as revealed by spontaneous dissociation and depletion of ncam1 mRNA in animal caps harvested from RARγ1 knockdown embryos. RARγ1 knockdown obliterates somite boundaries, and causes loss of Myod protein in the presomitic mesoderm, but ectopic, persistent expression of Myod protein in the trunk. Thus, RARγ1 is required for stabilizing the mesodermal fate, myogenic commitment, somite boundary formation, and terminal skeletal muscle differentiation.

Japanese GWAS identifies variants for bust-size, dysmenorrhea, and menstrual fever that are eQTLs for relevant protein-coding or long non-coding RNAs

Traits related to primary and secondary sexual characteristics greatly impact females during puberty and day-to-day adult life. Therefore, we performed a GWAS analysis of 11,348 Japanese female volunteers and 22 gynecology-related phenotypic variables, and identified significant associations for bust-size, menstrual pain (dysmenorrhea) severity, and menstrual fever. Bust-size analysis identified significant association signals in CCDC170-ESR1 (rs6557160; P = 1.7 × 10-16) and KCNU1-ZNF703 (rs146992477; P = 6.2 × 10-9) and found that one-third of known European-ancestry associations were also present in Japanese. eQTL data points to CCDC170 and ZNF703 as those signals' functional targets. For menstrual fever, we identified a novel association in OPRM1 (rs17181171; P = 2.0 × 10-8), for which top variants were eQTLs in multiple tissues. A known dysmenorrhea signal near NGF replicated in our data (rs12030576; P = 1.1 × 10-19) and was associated with RP4-663N10.1 expression, a putative lncRNA enhancer of NGF, while a novel dysmenorrhea signal in the IL1 locus (rs80111889; P = 1.9 × 10-16) contained SNPs previously associated with endometriosis, and GWAS SNPs were most significantly associated with IL1A expression. By combining regional imputation with colocalization analysis of GWAS/eQTL signals along with integrated annotation with epigenomic data, this study further refines the sets of candidate causal variants and target genes for these known and novel gynecology-related trait loci.

Integrative Modeling Identifies Key Determinants of Inhibitor Sensitivity in Breast Cancer Cell Lines

Cancer cell lines differ greatly in their sensitivity to anticancer drugs as a result of different oncogenic drivers and drug resistance mechanisms operating in each cell line. Although many of these mechanisms have been discovered, it remains a challenge to understand how they interact to render an individual cell line sensitive or resistant to a particular drug. To better understand this variability, we profiled a panel of 30 breast cancer cell lines in the absence of drugs for their mutations, copy number aberrations, mRNA, protein expression and protein phosphorylation, and for response to seven different kinase inhibitors. We then constructed a knowledge-based, Bayesian computational model that integrates these data types and estimates the relative contribution of various drug sensitivity mechanisms. The resulting model of regulatory signaling explained the majority of the variability observed in drug response. The model also identified cell lines with an unexplained response, and for these we searched for novel explanatory factors. Among others, we found that 4E-BP1 protein expression, and not just the extent of phosphorylation, was a determinant of mTOR inhibitor sensitivity. We validated this finding experimentally and found that overexpression of 4E-BP1 in cell lines that normally possess low levels of this protein is sufficient to increase mTOR inhibitor sensitivity. Taken together, our work demonstrates that combining experimental characterization with integrative modeling can be used to systematically test and extend our understanding of the variability in anticancer drug response.Significance: By estimating how different oncogenic mutations and drug resistance mechanisms affect the response of cancer cells to kinase inhibitors, we can better understand and ultimately predict response to these anticancer drugs.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/15/4396/F1.large.jpg Cancer Res; 78(15); 4396-410. ©2018 AACR.

Discoidin domain receptor 1 (DDR1) ablation promotes tissue fibrosis and hypoxia to induce aggressive basal-like breast cancers

Here, Takai et al. researched the function of discoidin domain receptor 1 (DDR1), a member of the subfamily of receptor tyrosine kinases activated by collagens that is overexpressed in breast and other carcinoma cells. Using bioinformatics analysis, breast cancer cell lines, and knockout mice, they demonstrate that DDR1 ablation leads to aggressive breast cancer, and their findings suggest that the absence of DDR1 provides a growth and adhesion advantage that favors the expansion of basal cells, potentiates fibrosis, and enhances necrosis/hypoxia and basal differentiation of transformed cells to increase their aggression and metastatic potential.

The discoidin domain receptor 1 (DDR1) is overexpressed in breast carcinoma cells. Low DDR1 expression is associated with worse relapse-free survival, reflecting its controversial role in cancer progression. We detected DDR1 on luminal cells but not on myoepithelial cells of DDR1^+/+ mice. We found that DDR1 loss compromises cell adhesion, consistent with data that older DDR1^−/− mammary glands had more basal/myoepithelial cells. Basal cells isolated from older mice exerted higher traction forces than the luminal cells, in agreement with increased mammary branches observed in older DDR1^−/− mice and higher branching by their isolated organoids. When we crossed DDR1^−/− mice with MMTV-PyMT mice, the PyMT/DDR1^−/− mammary tumors grew faster and had increased epithelial tension and matricellular fibrosis with a more basal phenotype and increased lung metastases. DDR1 deletion induced basal differentiation of CD90⁺CD24⁺ cancer cells, and the increase in basal cells correlated with tumor cell mitoses. K14⁺ basal cells, including K8⁺K14⁺ cells, were increased adjacent to necrotic fields. These data suggest that the absence of DDR1 provides a growth and adhesion advantage that favors the expansion of basal cells, potentiates fibrosis, and enhances necrosis/hypoxia and basal differentiation of transformed cells to increase their aggression and metastatic potential.

Overexpression of ZNF703 facilitates tumorigenesis and predicts unfavorable prognosis in patients with cholangiocarcinoma

Background

NET (NocA/Nlz, Elbow, Tlp-1) family members have recently emerged as important players in the development of human cancers. Zinc finger protein 703 (ZNF703), locating on chromosome 8 (8p11.23), a member of the NET/Nlz family of zinc finger transcription factors, had been demonstrated to be a much novel oncogene of several malignancies. This study aimed to investigate the expression of ZNF703 in cholangiocarcinoma (CCA) and attempted to elucidate its biological effects in CCA progression.

Methods

The correlation between ZNF703 expression and clinicopathological characteristics of CCA was evaluated through analyzing 85 cases. The biological effects of ZNF703 were investigated both in vitro and in vivo in which proliferation, migration, and invasive potential were mainly explored. Statistical software SPSS 16.0 was used for statistical analyses.

Results

ZNF703 was overexpressed in CCA tissues with subcellular localizations mainly in the nucleus and partly in the cytoplasm or membrane. High expression of ZNF703 was related to tumor location (P=0.002), pathological grading (P=0.024), depth of invasion (P=0.002), distant metastasis (P=0. 011) and AJCC stage (P=0.008). Both in vitro and in vivo studies demonstrated that ZNF703 could potently promote proliferation, migration and invasion throughout the progression of CCA.

Conclusion

ZNF703 can potently facilitate tumor growth and metastasis in many respects throughout the progression of CCA, which may act as an oncogene in CCA and can be considered as a novel potential therapeutic target.

SOX2 Drives Bronchial Dysplasia in a Novel Organotypic Model of Early Human Squamous Lung Cancer

RATIONALE

Improving the early detection and chemoprevention of lung cancer are key to improving outcomes. The pathobiology of early squamous lung cancer is poorly understood. We have shown that amplification of sex-determining region Y-box 2 (SOX2) is an early and consistent event in the pathogenesis of this disease, but its functional oncogenic potential remains uncertain. We tested the impact of deregulated SOX2 expression in a novel organotypic system that recreates the molecular and microenvironmental context in which squamous carcinogenesis occurs.

OBJECTIVES

(1) To develop an in vitro model of bronchial dysplasia that recapitulates key molecular and phenotypic characteristics of the human disease; (2) to test the hypothesis that SOX2 deregulation is a key early event in the pathogenesis of bronchial dysplasia; and (3) to use the model for studies on pathogenesis and chemoprevention.

METHODS

We engineered the inducible activation of oncogenes in immortalized bronchial epithelial cells. We used three-dimensional tissue culture to build an organotypic model of bronchial dysplasia.

MEASUREMENTS AND MAIN RESULTS

We recapitulated human bronchial dysplasia in vitro. SOX2 deregulation drives dysplasia, and loss of tumor promoter 53 is a cooperating genetic event that potentiates the dysplastic phenotype. Deregulated SOX2 alters critical genes implicated in hallmarks of cancer progression. Targeted inhibition of AKT prevents the initiation of the dysplastic phenotype.

CONCLUSIONS

In the appropriate genetic and microenvironmental context, acute deregulation of SOX2 drives bronchial dysplasia. This confirms its oncogenic potential in human cells and affords novel insights into the impact of SOX2 deregulation. This model can be used to test therapeutic agents aimed at chemoprevention.

Development of mammary hyperplasia, dysplasia, and invasive ductal carcinoma in transgenic mice expressing the 8p11 amplicon oncogene NSD3

PURPOSE

NSD3 has been implicated as a candidate driver oncogene from the 8p11-p12 locus, and we have previously published evidence for its amplification and overexpression in human breast cancer. This aim of this study was to further characterize the transforming function of NSD3 in vivo.

METHODS

We generated a transgenic mouse model in which NSD3 gene expression was driven by the MMTV promoter and expressed in mammary epithelium of FVB mice. Mammary glands were fixed and whole mounts were stained with carmine to visualize gland structure. Mammary tumors were formalin-fixed, and paraffin embedded (FFPE) tumors were stained with hematoxylin and eosin.

RESULTS

Pups born to transgenic females were significantly underdeveloped compared to pups born to WT females due to a lactation defect in transgenic female mice. Whole mount analysis of the mammary glands of transgenic female mice revealed a profound defect in functional differentiation of mammary gland alveoli that resulted in the lactation defect. We followed parous and virgin NSD3 transgenic and control mice to 50 weeks of age and observed that several NSD3 parous females developed mammary tumors. Whole mount analysis of the mammary glands of tumor-bearing mice revealed numerous areas of mammary hyperplasia and ductal dysplasia. Histological analysis showed that mammary tumors were high-grade ductal carcinomas, and lesions present in other mammary glands exhibited features of alveolar hyperplasia, ductal dysplasia, and carcinoma in situ.

CONCLUSIONS

Our results are consistent with our previous studies and demonstrate that NSD3 is a transforming breast cancer oncogene.

ZNF503/Zpo2 drives aggressive breast cancer progression by down-regulation of GATA3 expression

The transcription factor GATA3 is the master regulator that drives mammary luminal epithelial cell differentiation and maintains mammary gland homeostasis. Loss of GATA3 is associated with aggressive breast cancer development. We have identified ZNF503/ZEPPO2 zinc-finger elbow-related proline domain protein 2 (ZPO2) as a transcriptional repressor of GATA3 expression and transcriptional activity that induces mammary epithelial cell proliferation and breast cancer development. We show that ZPO2 is recruited to GATA3 promoter in association with ZBTB32 (Repressor of GATA, ROG) and that ZBTB32 is essential for down-regulation of GATA3 via ZPO2. Through this modulation of GATA3 activity, ZPO2 promotes aggressive breast cancer development. Our data provide insight into a mechanism of GATA3 regulation, and identify ZPO2 as a possible candidate gene for future diagnostic and therapeutic strategies.

Evolution of the NET (NocA, Nlz, Elbow, TLP-1) protein family in metazoans: insights from expression data and phylogenetic analysis

The NET (for NocA, Nlz, Elbow, TLP-1) protein family is a group of conserved zinc finger proteins linked to embryonic development and recently associated with breast cancer. The members of this family act as transcriptional repressors interacting with both class I histone deacetylases and Groucho/TLE co-repressors. In Drosophila, the NET family members Elbow and NocA are vital for the development of tracheae, eyes, wings and legs, whereas in vertebrates ZNF703 and ZNF503 are important for the development of the nervous system, eyes and limbs. Despite the relevance of this protein family in embryogenesis and cancer, many aspects of its origin and evolution remain unknown. Here, we show that NET family members are present and expressed in multiple metazoan lineages, from cnidarians to vertebrates. We identified several protein domains conserved in all metazoan species or in specific taxonomic groups. Our phylogenetic analysis suggests that the NET family emerged in the last common ancestor of cnidarians and bilaterians and that several rounds of independent events of gene duplication occurred throughout evolution. Overall, we provide novel data on the expression and evolutionary history of the NET family that can be relevant to understanding its biological role in both normal conditions and disease.

ZNF703 Overexpression may act as an oncogene in non-small cell lung cancer

Despite therapeutic advances, lung cancer remains one of the most common causes of cancer‐related deaths worldwide. The ZNF703 gene has been identified as the driver of the 8p11‐12 region and its amplification or overexpression has been associated with several types of cancers. It has also been shown that ZNF703 overexpression can activate the Akt/mTOR signaling pathway. The aim of our study was to investigate the role of the ZNF703 gene in association with Akt/mTOR activation in non‐small cell lung cancer (NSCLC). Expression levels in tumors and matched noncancerous tissue samples from 47 patients were analyzed by qRT‐PCR and the Akt phosphorylation levels were investigated by Western blotting. Our results show that ZNF703 is up‐regulated in 63.4% of NSCLC tumor samples. Althogh the correlation did not reach a statistically significant level Akt phosphorylation was increased in tumor tissues expressing high levels of ZNF703. The role of the ZNF703 gene has not been investigated in NSCLC. Our data show that ZNF703 may contribute to tumor development in NSCLC by activating the Akt/mTOR pathway.

Zfp703 Is a Wnt/β-Catenin Feedback Suppressor Targeting the β-Catenin/Tcf1 Complex

The Wnt/β-catenin signaling pathway controls embryonic development and adult stem cell maintenance through the regulation of transcription. Failure to downregulate Wnt signaling can result in embryonic malformations and cancer, highlighting the important role of negative regulators of the pathway. The Wnt pathway activates several negative feedback targets, including axin2 and Dkk1, that function at different levels of the signaling cascade; however, none have been identified that directly target active β-catenin/Tcf1 transcriptional complexes. We show that Zfp703 is a Wnt target gene that inhibits Wnt/β-catenin activity in Wnt reporter assays and in Wnt-dependent mesoderm differentiation in embryonic stem cells. Zfp703 binds directly to Tcf1 to inhibit β-catenin/Tcf1 complex formation and does so independently of the Groucho/Tle transcriptional corepressor. We propose that Zfp703 is a novel feedback suppressor of Wnt/β-catenin signaling that functions by inhibiting the association of β-catenin with Tcf1 on Wnt response elements in target gene enhancers.

Quantitative proteomic analyses of mammary organoids reveals distinct signatures after exposure to environmental chemicals

Common environmental contaminants such as bisphenols and phthalates and persistent contaminants such as polychlorinated biphenyls are thought to influence tissue homeostasis and carcinogenesis by acting as disrupters of endocrine function. In this study we investigated the direct effects of exposure to bisphenol A (BPA), mono-n-butyl phthalate (Pht), and polychlorinated biphenyl 153 (PCB153) on the proteome of primary organotypic cultures of the mouse mammary gland. At low-nanomolar doses each of these agents induced distinct effects on the proteomes of these cultures. Although BPA treatment produced effects that were similar to those induced by estradiol, there were some notable differences, including a reduction in the abundance of retinoblastoma-associated protein and increases in the Rho GTPases Ras-related C3 botulinum toxin substrate 1 (Rac1) and cell division cycle protein CDC42. Both Pht and PCB153 induced changes that were distinct from those induced by estrogen, including decreased levels of the transcriptional corepressor C-terminal binding protein 1. Interestingly, the three chemicals appeared to alter the abundance of distinct splice forms of many proteins as well as the abundance of several proteins that regulate RNA splicing. Our combined results indicate that the three classes of chemical have distinct effects on the proteome of normal mouse mammary cultures, some estrogen-like but most estrogen independent, that influence diverse biological processes including apoptosis, cell adhesion, and proliferation.

New transcription factors involved with postnatal ventral prostate gland development in male Wistar rats during the first week

AIMS

The high incidence in men of prostatic diseases, including benign and malignant tumors, makes the understanding of prostate development and biology very important. Understanding the organogenesis of the prostate gland has been a substantial challenge as "prostatic code" is not well defined at the present time. The novelty of this work lies in unveiling new transcription factors (TFs) during neonatal ventral prostate (VP) gland development in male Wistar rats.

MAIN METHODS

The techniques of qRT-PCR and immunohistochemistry have been employed to perform this work while the VP gland was obtained from neonatal rats at day zero (the day of birth) day 3 and 6.

KEY FINDINGS

16 TFs were studied and we found an increased expression of Eya2, Lhrh and Znf142, invariable levels of Znf703 and Dbp, and decreased expression of 11 others at postnatal development day 3 and 6 as compared to day zero. ZNF703 was found by immunohistochemistry in epithelial cells at days 0, 3 and 6. qRT-PCR for Eya2 and Dmrt2 showed the highest and lowest fold change for them respectively, and immunohistochemistry showed that the former is being expressed at the three selected time points while the latter appears to be diminishing with very few cells expressing it until day 6.

SIGNIFICANCE

Results from this work is reporting the role of these TFs for the first time and will significantly contribute to the current understanding of the development and branching morphogenesis of the neonatal VP gland during the first week of postnatal development.

Phosphorylation and isoform use in p120-catenin during development and tumorigenesis

P120-catenin is essential to vertebrate development, modulating cadherin and small-GTPase functions, and growing evidence points also to roles in the nucleus. A complexity in addressing p120-catenin's functions is its many isoforms, including optional splicing events, alternative points of translational initiation, and secondary modifications. In this review, we focus upon how choices in the initiation of protein translation, or the earlier splicing of the RNA transcript, relates to primary sequences that harbor established or putative regulatory phosphorylation sites. While certain p120 phosphorylation events arise via known kinases/phosphatases and have defined outcomes, in most cases the functional consequences are still to be established. In this review, we provide examples of p120-isoforms as they relate to phosphorylation events, and thereby to isoform dependent protein-protein associations and downstream functions. We also provide a view of upstream pathways that determine p120's phosphorylation state, and that have an impact upon development and disease. Because other members of the p120 subfamily undergo similar processing and phosphorylation, as well as related catenins of the plakophilin subfamily, what is learned regarding p120 will by extension have wide relevance in vertebrates.

nlz1 is required for cilia formation in zebrafish embryogenesis

The formation of cilia is a fundamental developmental process affecting diverse functions such as cellular signaling, tissue morphogenesis and body patterning. However, the mechanisms of ciliogenesis during vertebrate development are not fully understood. In this report we describe a novel role of the Nlz1 protein in ciliogenesis. We demonstrate morpholino-mediated knockdown of nlz1 in zebrafish causes abnormal specification of the cells of Kupffer's vesicle (KV); a severe reduction of the number of cilia in KV, the pronephros, and the neural floorplate; and a spectrum of later phenotypes reminiscent of human ciliopathies. In vitro and in vivo data indicate that Nlz1 acts downstream of Foxj1a and Wnt8a/presumed canonical Wnt signaling. Furthermore, Nlz1 contributes to motile cilia formation by positively regulating Wnt11/presumed non-canonical Wnt signaling. Together, our data suggest a novel role of nlz1 in ciliogenesis and the morphogenesis of multiple tissues.

Imipramine blue halts head and neck cancer invasion through promoting F-box and leucine-rich repeat protein 14-mediated Twist1 degradation

The unique characteristic of head and neck squamous cell carcinoma (HNSCC) is that local invasion rather than distant metastasis is the major route for dissemination. Therefore, targeting the locally invasive cancer cells is more important than preventing systemic metastasis in HNSCC and other invasive-predominant cancers. We previously demonstrate a specific mechanism for HNSCC local invasion: the epithelial-mesenchymal transition (EMT) regulator Twist1 represses microRNA let-7i expression, leading to the activation of the small GTPase Rac1 and engendering the mesenchymal-mode movement in three-dimensional (3D) culture. However, targeting the EMT regulator is relatively difficult because of its transcription factor nature and the strategy for confining HNSCC invasion to facilitate local treatment is limited. Imipramine blue (IB) is a newly identified anti-invasive compound that effectively inhibits glioma invasion. Here we demonstrate that in HNSCC cells, a noncytotoxic dose of IB represses mesenchymal-mode migration in two-and-a-half-dimensional/3D culture system. IB suppresses EMT and stemness of HNSCC cells through inhibition of Twist1-mediated let-7i downregulation and Rac1 activation and the EMT signalling. Mechanistically, IB inhibits reactive oxygen species-induced nuclear factor-κB pathway activation. Importantly, IB promotes degradation of the EMT inducer Twist1 by enhancing F-box and leucine-rich repeat protein 14 (FBXL14)-mediated polyubiquitination of Twist1. Together, this study demonstrates the potent anti-invasion and EMT-inhibition effect of IB, suggesting the potential of IB in treating local invasion-predominant cancers.

Elevated ZNF703 Protein Expression Is an Independent Unfavorable Prognostic Factor for Survival of the Patients with Head and Neck Squamous Cell Carcinoma

AIM

Data from The Cancer Genome Atlas (TCGA) show that the ZNF703 gene amplifies and overexpresses in head and neck squamous cell carcinomas (HNSCC). However, the clinical relevance of this observation in HNSCC is unclear. The purpose of this study was to clarify the expression of ZNF703 protein and its prognostic effect on HNSCC.

METHODS

Two hundred ten HNSCC patients from Sun Yat-Sen University Cancer Center with complete survival follow-up were included in this study. Tumor samples from primary sites were collected. The expression of the ZNF703 protein was tested by immunohistochemistry (IHC).

RESULTS

The high expression of ZNF703 in HNSCC tumor tissues was significantly higher than that of the matched noncancerous tissues (48.6% versus 11.6%, P < 0.001). ZNF703 overexpression was correlated with tumor position (laryngeal carcinoma) and recurrence (all P < 0.05). Multivariate analysis revealed that ZNF703 protein overexpression was an independent prognostic factor (P = 0.022, hazard ratio = 1.635, 95% CI 1.073-2.493) in HNSCC patients.

CONCLUSION

ZNF703 overexpression is associated with adverse prognosis in HNSCC, which might be a novel biomarker of HNSCC.

Vimentin-ERK Signaling Uncouples Slug Gene Regulatory Function

Epithelial-mesenchymal transition (EMT) in cells is a developmental process adopted during tumorigenesis that promotes metastatic capacity. In this study, we advance understanding of EMT control in cancer cells with the description of a novel vimentin-ERK axis that regulates the transcriptional activity of Slug (SNAI2). Vimentin, ERK, and Slug exhibited overlapping subcellular localization in clinical specimens of triple-negative breast carcinoma. RNAi-mediated ablation of these gene products inhibited cancer cell migration and cell invasion through a laminin-rich matrix. Biochemical analyses demonstrated direct interaction of vimentin and ERK, which promoted ERK activation and enhanced vimentin transcription. Consistent with its role as an intermediate filament, vimentin acted as a scaffold to recruit Slug to ERK and promote Slug phosphorylation at serine-87. Site-directed mutagenesis established a requirement for ERK-mediated Slug phosphorylation in EMT initiation. Together, these findings identified a pivotal step in controlling the ability of Slug to organize hallmarks of EMT.

The long noncoding RNA SPRY4-IT1 increases the proliferation of human breast cancer cells by upregulating ZNF703 expression

Background

Long noncoding RNAs (lncRNAs) have emerged recently as a new class of genes that regulate cellular processes, such as cell growth and apoptosis. The SPRY4 intronic transcript 1 (SPRY4-IT1) is a 708-bp lncRNA on chromosome 5 with a potential functional role in tumorigenesis. The clinical significance of SPRY4-IT1 and the effect of SPRY4-IT1 on cancer progression are unclear.

Methods

Quantitative reverse transcriptase PCR (qRT-PCR) was performed to investigate the expression of SPRY4-IT1 in 48 breast cancer tissues and four breast cancer cell lines. Gain and loss of function approaches were used to investigate the biological role of SPRY4-IT1 in vitro. Microarray bioinformatics analysis was performed to identify the putative targets of SPRY4-IT1, which were further verified by rescue experiments, and by western blotting and qRT-PCR.

Results

SPRY4-IT1 expression was significantly upregulated in 48 breast cancer tumor tissues comparedwith normal tissues. Additionally, increased SPRY4-IT1 expression was found to be associated with a larger tumor size and an advanced pathological stage in breast cancer patients. The knockdown of SPRY4-IT1 significantly suppressed proliferation and caused apoptosis of breast cancer cells in vitro. Furthermore, we discovered that ZNF703 was a target of SPRY4-IT1 and was downregulated by SPRY4-IT1 knockdown. Moreover, we provide the first demonstration that ZNF703 plays an oncogenic role in ER (−) breast carcinoma cells.

Conclusions

SPRY4-IT1 is a novel prognostic biomarker and a potential therapeutic candidate for breast cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-015-0318-0) contains supplementary material, which is available to authorized users.

Amplification of chromosome 8 genes in lung cancer

Chromosomal alterations are frequent events in lung carcinogenesis and usually display regions of focal amplification containing several overexpressed oncogenes. Although gains and losses of chromosomal loci have been reported copy number changes of the individual genes have not been analyzed in lung cancer. In this study 22 genes were analyzed by MLPA in tumors and matched normal tissue samples from 82 patients with non-small cell lung cancer. Gene amplifications were observed in 84% of the samples. Chromosome 8 was found to harbor the most frequent copy number alterations. The most frequently amplified genes were ZNF703, PRDM14 and MYC on chromosome 8 and the BIRC5 gene on chromosome 17. The frequency of deletions were much lower and the most frequently deleted gene was ADAM9. Amplification of the ZNF703, PRDM14 and MYC genes were highly correlated suggesting that the genes displaying high copy number changes on chromosome 8 collaborate during lung carcinogenesis.

The Transcriptional Repressor ZNF503/Zeppo2 Promotes Mammary Epithelial Cell Proliferation and Enhances Cell Invasion

The NET (nocA, Nlz, elB, TLP-1) subfamily of zinc finger proteins is an important mediator during developmental processes. The evolutionary conserved zinc finger protein ZNF503/Zeppo2 (zinc finger elbow-related proline domain protein 2, Zpo2) plays critical roles during embryogenesis. We found that Zpo2 is expressed in adult tissue and examined its function. We found that ZPO2 is a nuclearly targeted transcriptional repressor that is expressed in mammary epithelial cells. Elevated Zpo2 levels increase mammary epithelial cell proliferation. Zpo2 promotes cellular invasion through down-regulation of E-cadherin and regulates the invasive phenotype in a RAC1-dependent manner. We detect elevated Zpo2 expression during breast cancer progression in a MMTV-PyMT transgenic mouse model. Tumor transplant experiments indicated that overexpression of Zpo2 in MMTV-PyMT mammary tumor cell lines enhances lung metastasis. Our findings suggest that Zpo2 plays a significant role in mammary gland homeostasis and that deregulation of Zpo2 may promote breast cancer development.

Signaling pathway cooperation in TGF-β-induced epithelial-mesenchymal transition

Transdifferentiation of epithelial cells into cells with mesenchymal properties and appearance, that is, epithelial-mesenchymal transition (EMT), is essential during development, and occurs in pathological contexts, such as in fibrosis and cancer progression. Although EMT can be induced by many extracellular ligands, TGF-β and TGF-β-related proteins have emerged as major inducers of this transdifferentiation process in development and cancer. Additionally, it is increasingly apparent that signaling pathways cooperate in the execution of EMT. This update summarizes the current knowledge of the coordination of TGF-β-induced Smad and non-Smad signaling pathways in EMT, and the remarkable ability of Smads to cooperate with other transcription-directed signaling pathways in the control of gene reprogramming during EMT.

DIPA-family coiled-coils bind conserved isoform-specific head domain of p120-catenin family: potential roles in hydrocephalus and heterotopia

Isoform-specific expression of p120 affects cell motility and migration during development and tumor progression. The DIPA coiled-coil protein is a novel binding partner to the conserved isoform 1–specific head domain of p120 family members. Zebrafish data suggest that DIPA is mechanistically linked to p120 isoform–specific function in development.

p120-catenin (p120) modulates adherens junction (AJ) dynamics by controlling the stability of classical cadherins. Among all p120 isoforms, p120-3A and p120-1A are the most prevalent. Both stabilize cadherins, but p120-3A is preferred in epithelia, whereas p120-1A takes precedence in neurons, fibroblasts, and macrophages. During epithelial-to-mesenchymal transition, E- to N-cadherin switching coincides with p120-3A to -1A alternative splicing. These isoforms differ by a 101–amino acid “head domain” comprising the p120-1A N-terminus. Although its exact role is unknown, the head domain likely mediates developmental and cancer-associated events linked to p120-1A expression (e.g., motility, invasion, metastasis). Here we identified delta-interacting protein A (DIPA) as the first head domain–specific binding partner and candidate mediator of isoform 1A activity. DIPA colocalizes with AJs in a p120-1A- but not 3A-dependent manner. Moreover, all DIPA family members (Ccdc85a, Ccdc85b/DIPA, and Ccdc85c) interact reciprocally with p120 family members (p120, δ-catenin, p0071, and ARVCF), suggesting significant functional overlap. During zebrafish neural tube development, both knockdown and overexpression of DIPA phenocopy N-cadherin mutations, an effect bearing functional ties to a reported mouse hydrocephalus phenotype associated with Ccdc85c. These studies identify a novel, highly conserved interaction between two protein families that may participate either individually or collectively in N-cadherin–mediated development.

aldh7a1 regulates eye and limb development in zebrafish

Uveal coloboma is a potentially blinding congenital ocular malformation caused by failure of the optic fissure to close during development. Although mutations in numerous genes have been described, these account for a minority of cases, complicating molecular diagnosis and genetic counseling. Here we describe a key role of aldh7a1 as a gene necessary for normal eye development. We show that morpholino knockdown of aldh7a1 in zebrafish causes uveal coloboma and misregulation of nlz1, another known contributor to the coloboma phenotype, as well as skeletal abnormalities. Knockdown of aldh7a1 leads to reduced cell proliferation in the optic cup of zebrafish, delaying the approximation of the edges of the optic fissure. The aldh7a1 morphant phenotype is partially rescued by co-injection of nlz1 mRNA suggesting that nlz1 is functionally downstream of aldh7a1 in regulating cell proliferation in the optic cup. These results support a role of aldh7a1 in ocular development and skeletal abnormalities in zebrafish.

p120-catenin in cancer - mechanisms, models and opportunities for intervention

The epithelial adherens junction is an E-cadherin-based complex that controls tissue integrity and is stabilized at the plasma membrane by p120-catenin (p120, also known as CTNND1). Mutational and epigenetic inactivation of E-cadherin has been strongly implicated in the development and progression of cancer. In this setting, p120 translocates to the cytosol where it exerts oncogenic properties through aberrant regulation of Rho GTPases, growth factor receptor signaling and derepression of Kaiso (also known as ZBTB33) target genes. In contrast, indirect inactivation of the adherens junction through conditional knockout of p120 in mice was recently linked to tumor formation, indicating that p120 can also function as a tumor suppressor. Supporting these opposing functions are findings in human cancer, which show that either loss or cytoplasmic localization of p120 is a common feature in the progression of several types of carcinoma. Underlying this dual biological phenomenon might be the context-dependent regulation of Rho GTPases in the cytosol and the derepression of Kaiso target genes. Here, we discuss past and present findings that implicate p120 in the regulation of cancer progression and highlight opportunities for clinical intervention.

Molecular mechanisms of epithelial-mesenchymal transition

The transdifferentiation of epithelial cells into motile mesenchymal cells, a process known as epithelial-mesenchymal transition (EMT), is integral in development, wound healing and stem cell behaviour, and contributes pathologically to fibrosis and cancer progression. This switch in cell differentiation and behaviour is mediated by key transcription factors, including SNAIL, zinc-finger E-box-binding (ZEB) and basic helix-loop-helix transcription factors, the functions of which are finely regulated at the transcriptional, translational and post-translational levels. The reprogramming of gene expression during EMT, as well as non-transcriptional changes, are initiated and controlled by signalling pathways that respond to extracellular cues. Among these, transforming growth factor-β (TGFβ) family signalling has a predominant role; however, the convergence of signalling pathways is essential for EMT.

Genetic dissection of photoreceptor subtype specification by the Drosophila melanogaster zinc finger proteins elbow and no ocelli

The elbow/no ocelli (elb/noc) complex of Drosophila melanogaster encodes two paralogs of the evolutionarily conserved NET family of zinc finger proteins. These transcriptional repressors share a conserved domain structure, including a single atypical C2H2 zinc finger. In flies, Elb and Noc are important for the development of legs, eyes and tracheae. Vertebrate NET proteins play an important role in the developing nervous system, and mutations in the homolog ZNF703 human promote luminal breast cancer. However, their interaction with transcriptional regulators is incompletely understood. Here we show that loss of both Elb and Noc causes mis-specification of polarization-sensitive photoreceptors in the 'dorsal rim area' (DRA) of the fly retina. This phenotype is identical to the loss of the homeodomain transcription factor Homothorax (Hth)/dMeis. Development of DRA ommatidia and expression of Hth are induced by the Wingless/Wnt pathway. Our data suggest that Elb/Noc genetically interact with Hth, and we identify two conserved domains crucial for this function. Furthermore, we show that Elb/Noc specifically interact with the transcription factor Orthodenticle (Otd)/Otx, a crucial regulator of rhodopsin gene transcription. Interestingly, different Elb/Noc domains are required to antagonize Otd functions in transcriptional activation, versus transcriptional repression. We propose that similar interactions between vertebrate NET proteins and Meis and Otx factors might play a role in development and disease.

Impact of p120-catenin isoforms 1A and 3A on epithelial mesenchymal transition of lung cancer cells expressing E-cadherin in different subcellular locations

The epithelial mesenchymal transition (EMT) is an important process in tumor development. Despite previous investigations, it remains unclear how p120-catenin (p120ctn) isoforms 1A and 3A affect the EMT of tumor cells. Here we investigated expression of p120ctn, E-cadherin and vimentin in 78 human non-small cell lung cancer (NSCLC) samples by immunohistochemistry and found that p120ctn membrane expression positively correlated with E-cadherin expression (P<0.001) and negatively correlated with vimentin expression and lymph node metastasis (P<0.05). Meanwhile, p120ctn cytoplasmic expression negatively correlated with E-cadherin expression (P<0.001) and positively correlated with vimentin expression and lymph node metastasis (P<0.05). Cells expressing high (H460 and SPC) and low (H1299 and LK2) levels of p120ctn were screen to investigate its impact on EMT. E-cadherin was restricted to the cell membrane in H460 and H1299 cells, whereas it was expressed in the cytoplasm of SPC and LK2 cells. Ablation of endogenous p120ctn isoform 1A in cells expressing high levels of the protein resulted in decreased E-cadherin expression, increased N-cadherin, vimentin and snail expression and enhanced invasiveness in H460 cells. Meanwhile, completely opposite results were observed in SPC cells. Furthermore, transfection of in H1299 cells expressing low p120ctn levels with the p120ctn isoform 1A plasmid resulted in increased E-cadherin expression, decreased N-cadherin, vimentin and snail expression and weakened invasiveness, while LK2 cells showed completely opposite results. Both cell lines expressing low p120ctn levels and transfected with the p120ctn isoform 3A plasmid appeared to have increased E-cadherin expression, decreased N-cadherin, vimentin and snail expression and weakened invasiveness. In conclusion, in cells with membrane E-cadherin, both p120ctn isoforms 1A and 3A inhibited EMT and decreased cell invasiveness. In cells with cytoplasmic E-cadherin, p120ctn isoform 1A promoted EMT and increased cell invasiveness, while p120ctn isoform 3A inhibited the EMT and decreased cell invasiveness.