GATA3 plays an integral role in breast luminal cell differentiation and is implicated in breast cancer progression. GATA3 immunohistochemistry is a useful marker of breast cancer; however, its use in specific subtypes is unclear. Here, we evaluate GATA3 expression in 86 invasive ductal carcinomas including triple-negative, Her-2, and luminal subtypes, in addition to 13 metaplastic carcinomas and in 34 fibroepithelial neoplasms. In addition, we report GATA3 expression in matched primary and metastatic breast carcinomas in 30 patients with known estrogen receptor (ER), progesterone receptor (PR), and Her-2 status, including 5 with ER and/or PR loss from primary to metastasis. Tissue microarrays containing 5 to 10 cores per tumor were stained for GATA3, scored as follows: 0 (0-5%), 1+ (6%-25%), 2+ (26%-50%), 3+ (51%-75%), and 4+ (>75%). GATA3 labeling was seen in 67% (66/99) of primary ductal carcinomas including 43% of triple-negative and 54% of metaplastic carcinomas. In contrast, stromal GATA3 labeling was seen in only 1 fibroepithelial neoplasm. GATA3 labeling was seen in 90% (27/30) of primary breast carcinomas in the paired cohort, including 67% of triple-negative carcinomas. GATA3 labeling was overwhelmingly maintained in paired metastases. Notably, GATA3 was maintained in all "luminal loss" metastases, which showed ER and/or PR loss. In conclusion, GATA3 expression is maintained between matched primary and metastatic carcinomas including ER-negative cases. GATA3 can be particularly useful as a marker for metastatic breast carcinoma, especially triple-negative and metaplastic carcinomas, which lack specific markers of mammary origin. Finally, GATA3 labeling may help distinguish metaplastic carcinoma from malignant phyllodes tumors.

OBJECTIVE

Male breast cancer is rare, and its genomic landscape has yet to be fully characterized. Lacking studies in men, treatment of males with breast cancer is extrapolated from results in females with breast cancer. We sought to define whether male breast cancers harbor somatic genetic alterations in genes frequently altered in female breast cancers.

METHODS

All male breast cancers were estrogen receptor-positive, and all but two were HER2-negative. Fifty-nine male breast cancers were subtyped by immunohistochemistry, and tumor-normal pairs were microdissected and subjected to massively parallel sequencing targeting all exons of 241 genes frequently mutated in female breast cancers or DNA-repair related. The repertoires of somatic mutations and copy number alterations of male breast cancers were compared with that of subtype-matched female breast cancers.

RESULTS

Twenty-nine percent and 71% of male breast cancers were immunohistochemically classified as luminal A-like or luminal B-like, respectively. Male breast cancers displayed a heterogeneous repertoire of somatic genetic alterations that to some extent recapitulated that of estrogen receptor (ER)-positive/HER2-negative female breast cancers, including recurrent mutations affecting PIK3CA (20%) and GATA3 (15%). ER-positive/HER2-negative male breast cancers, however, less frequently harbored 16q losses, and PIK3CA and TP53 mutations than ER-positive/HER2-negative female breast cancers. In addition, male breast cancers were found to be significantly enriched for mutations affecting DNA repair-related genes.

CONCLUSIONS

Male breast cancers less frequently harbor somatic genetic alterations typical of ER-positive/HER2-negative female breast cancers, such as PIK3CA and TP53 mutations and losses of 16q, suggesting that at least a subset of male breast cancers are driven by a distinct repertoire of somatic changes. Given the genomic differences, caution may be needed in the application of biologic and therapeutic findings from studies of female breast cancers to male breast cancers. Clin Cancer Res; 22(16); 4045-56. ©2016 AACR.

Age-adjusted mortality rates for prostate cancer are higher for African-American men compared with those of European ancestry. Recent data suggest that West African men also have elevated risk for prostate cancer relative to European men. Genetic susceptibility to prostate cancer could account for part of this difference. We conducted a genome-wide association study (GWAS) of prostate cancer in West African men in the Ghana Prostate Study. Association testing was performed using multivariable logistic regression adjusted for age and genetic ancestry for 474 prostate cancer cases and 458 population-based controls on the Illumina HumanOmni-5 Quad BeadChip. The most promising association was at 10p14 within an intron of a long non-coding RNA (lncRNA RP11-543F8.2) 360 kb centromeric of GATA3 (p = 1.29E-7). In sub-analyses, SNPs at 5q31.3 were associated with high Gleason score (≥7) cancers, the strongest of which was a missense SNP in PCDHA1 (rs34575154, p = 3.66E-8), and SNPs at Xq28 (rs985081, p = 8.66E-9) and 6q21 (rs2185710, p = 5.95E-8) were associated with low Gleason score (<7) cancers. We sought to validate our findings in silico in the African Ancestry Prostate Cancer GWAS Consortium, but only one SNP, at 10p14, replicated at p < 0.05. Of the 90 prostate cancer loci reported from studies of men of European, Asian or African-American ancestry, we were able to test 81 in the Ghana Prostate Study, and 10 of these replicated at p < 0.05. Further genetic studies of prostate cancer in West African men are needed to confirm our promising susceptibility loci.

Differentiation of naive CD4 T cells into Th2 cells is accompanied by chromatin remodeling and increased expression of a set of Th2-specific genes, including those encoding Th2 cytokines. IL-4-mediated STAT6 activation induces high levels of transcription of GATA3, a master regulator of Th2 cell differentiation, and enforced expression of GATA3 induces Th2 cytokine expression. However, it remains unclear whether the expression of other Th2-specific genes is induced directly by GATA3. A genome-wide unbiased chromatin immunoprecipitation assay coupled with massive parallel sequencing analysis revealed that GATA3 bound to 1279 genes selectively in Th2 cells, and 101 genes in both Th1 and Th2 cells. Simultaneously, we identified 26 highly Th2-specific STAT6-dependent inducible genes by DNA microarray analysis-based three-step selection processes, and among them 17 genes showed GATA3 binding. We assessed dependency on GATA3 for the transcription of these 26 Th2-specific genes, and 10 genes showed increased transcription in a GATA3-dependent manner, whereas 16 genes showed no significant responses. The transcription of the 16 GATA3-nonresponding genes was clearly increased by the introduction of an active form of STAT6, STAT6VT. Therefore, although GATA3 has been recognized as a master regulator of Th2 cell differentiation, many Th2-specific genes are not regulated by GATA3 itself, but in collaboration with STAT6.

GATA3 is a highly conserved, essential transcription factor expressed in a number of tissues, including the mammary gland. GATA3 expression is required for normal development of the mammary gland where it is estimated to be the most abundant transcription factor in luminal epithelial cells. In breast cancer, GATA3 expression is highly correlated with the luminal transcriptional program. Recent genomic analysis of human breast cancers has revealed high-frequency mutation in GATA3 in luminal tumors, suggesting "driver" function(s). Here we discuss mutation of GATA3 in breast cancer and the potential mechanism(s) by which mutation may lead to a growth advantage in cancer.

The differentiation of naïve T helper (Th) cells is induced by TCR activation and IL-12/STAT4 or IL-4/STAT6 signaling pathways, forming Th1 and Th2 cells, respectively. In this study, oligonucleotide arrays were used to identify genes regulated during the initiation of human Th1 and Th2 cell differentiation at 2 and 6 h in presence or absence of immunosuppressive TGF-beta. As a result the immediate targets of IL-12, IL-4 and TGF-beta were identified. The effects of IL-12 at this early stage were minimal and consistent with the known kinetics of IL-12Rbeta2 expression. IL-4, however, was observed to rapidly regulate 63 genes, 26 of which were differentially expressed at both the 2- and 6-h time points. Of these IL-4 regulated genes, one-third have previously been observed to display expression changes in the later phases of the polarization process. Similarly to the key regulators, TBX21 and GATA3, the transcription factors SATB1, TCF7 and BCL6 were differentially regulated at the protein level during early Th1 and Th2 cell polarization. Moreover, the developing Th1 and Th2 cells were demonstrated to be responsive to the immunosuppressive TGF-beta and IL-10. In this study, a panel of novel factors that may be important regulators of the differentiation process was identified.

The transcription factor GATA-3 is essential for early T cell development and differentiation of naive CD4(+) T cells into Th2 effector cells. To study the function of GATA-3 during T cell-mediated immune responses in vivo, we investigated CD2-GATA3-transgenic mice in which GATA-3 expression is driven by the CD2 locus control region. Both in the CD4(+) and the CD8(+) T cell population the proportion of cells exhibiting a CD44(high)CD45RB(low)CD62L(low) Ag-experienced phenotype was increased. In CD2-GATA3-transgenic mice, large fractions of peripheral CD4(+) T cells expressed the IL-1 receptor family member T1/ST2, indicative of advanced Th2 commitment. Upon in vitro T cell stimulation, the ability to produce IL-2 and IFN-gamma was decreased. Moreover, CD4(+) T cells manifested rapid secretion of the Th2 cytokines IL-4, IL-5, and IL-10, reminiscent of Th2 memory cells. In contrast to wild-type CD4(+) cells, which lost GATA-3 expression when cultured under Th1-polarizing conditions, CD2-GATA3-transgenic CD4(+) cells maintained expression of GATA-3 protein. Under Th1 conditions, cellular proliferation of CD2-GATA3-transgenic CD4(+) cells was severely hampered, IFN-gamma production was decreased and Th2 cytokine production was increased. Enforced GATA-3 expression inhibited Th1-mediated in vivo responses, such as Ag-specific IgG2a production or a delayed-type hypersensitivity response to keyhole limpet hemocyanin. Collectively, these observations indicate that enforced GATA-3 expression selectively inhibits Th1 differentiation and induces Th2 differentiation. The increased functional capacity to secrete Th2 cytokines, along with the increased expression of surface markers for Ag-experienced Th2-committed cells, would argue for a role of GATA-3 in Th2 memory formation.

Dietary factors, including meat, fruits, vegetables and fiber, are associated with colorectal cancer; however, there is limited information as to whether these dietary factors interact with genetic variants to modify risk of colorectal cancer. We tested interactions between these dietary factors and approximately 2.7 million genetic variants for colorectal cancer risk among 9,287 cases and 9,117 controls from ten studies. We used logistic regression to investigate multiplicative gene-diet interactions, as well as our recently developed Cocktail method that involves a screening step based on marginal associations and gene-diet correlations and a testing step for multiplicative interactions, while correcting for multiple testing using weighted hypothesis testing. Per quartile increment in the intake of red and processed meat were associated with statistically significant increased risks of colorectal cancer and vegetable, fruit and fiber intake with lower risks. From the case-control analysis, we detected a significant interaction between rs4143094 (10p14/near GATA3) and processed meat consumption (OR = 1.17; p = 8.7E-09), which was consistently observed across studies (p heterogeneity = 0.78). The risk of colorectal cancer associated with processed meat was increased among individuals with the rs4143094-TG and -TT genotypes (OR = 1.20 and OR = 1.39, respectively) and null among those with the GG genotype (OR = 1.03). Our results identify a novel gene-diet interaction with processed meat for colorectal cancer, highlighting that diet may modify the effect of genetic variants on disease risk, which may have important implications for prevention.

Special AT-rich binding protein 1 (SATB1) is a global chromatin organizer and a transcription factor regulated by interleukin-4 (IL-4) during the early T helper 2 (Th2) cell differentiation. Here we show that SATB1 controls multiple IL-4 target genes involved in human Th cell polarization or function. Among the genes regulated by SATB1 is that encoding the cytokine IL-5, which is predominantly produced by Th2 cells and plays a key role in the development of eosinophilia in asthma. We demonstrate that, during the early Th2 cell differentiation, IL-5 expression is repressed through direct binding of SATB1 to the IL-5 promoter. Furthermore, SATB1 knockdown-induced up-regulation of IL-5 is partly counteracted by down-regulating GATA3 expression using RNAi in polarizing Th2 cells. Our results suggest that a competitive mechanism involving SATB1 and GATA3 regulates IL-5 transcription, and provide new mechanistic insights into the stringent regulation of IL-5 expression during human Th2 cell differentiation.

We have reported that injection of marijuana cannabinoids, such as Delta(9)-tetrahydrocannabinol (THC), into mice, followed by infection with Legionella pneumophila (Lp), suppresses the development of cell-mediated immunity T helper 1 (Th1) activity. These effects are accompanied by suppression of interleukin (IL)-12 and interferon (IFN) gamma production and enhancement of IL-4 production suggesting THC-induced T helper cell biasing. In the current report, other T helper cell biasing mechanisms were studied. Mice were injected with THC followed 18 h later by a challenge infection with Lp. Two-hour post-infection, spleens were removed and analyzed for mRNA to either IL-12Rbeta2 or GATA3 gene products. The results showed that THC suppressed IL-12Rbeta2 but increased GATA3. Receptor antagonists for CB1 (SR141716A, SR1) and CB2 (SR144528, SR2) were also injected to analyze the involvement of cannabinoid receptors. It was determined that SR1 attenuated the THC suppression of IL-12Rbeta2, while SR2 attenuated the increase in GATA3 mRNA. These results suggest that THC suppresses Th1 biasing activity such as IL-12Rbeta2 by a CB1 mediated mechanism and enhances the Th2 biasing activity, GATA3, by a CB2 mechanism. This dichotomy of receptor involvement might result from differential expression and/or signaling function of CB1 and CB2 on Th1 and Th2 cells.

Naïve T helper (Th) cells differentiate in response to antigen stimulation into either Th1 or Th2 effector cells, which are characterized by the secretion of different set of cytokines. Th2 differentiation, which is critical for allergic airway disease, is triggered by signals of the T-cell receptor (TCR) and the cytokines generated during polarization, particularly IL-4. We determine here the potential role of the signaling adapter p62 in T-cell polarization. We report using p62-/- mice and cells that p62 acts downstream TCR activation, and is important for Th2 polarization and asthma, playing a significant role in the control of the sustained activation of NF-kappaB and late synthesis of GATA3 and IL-4 by participating in the activation of the IKK complex.

The pathogenesis of allergic asthma involves the interplay of inflammatory cells and resident airway cells, and of their secreted mediators including cytokines, chemokines, growth factors and inflammatory mediators. Tyrosine kinase signaling cascades play a critical role in the pathogenesis of allergic airway inflammation. Receptor tyrosine kinases (e.g. epidermal growth factor receptor [EGFR] and platelet-derived growth factor receptor) are important for the pathogenesis of airway remodeling. Stimulation of non-receptor tyrosine kinases (e.g. Lyn, Lck, Syk, ZAP-70, Btk, Itk and JAK) is the earliest detectable signaling response upon activation of immune receptors (T cell receptor, B cell receptor and FCepsilonR1), cytokine receptors and chemokine receptors in inflammatory cells. Activation of tyrosine kinases invokes multiple downstream signaling pathways, including phosphoinositide 3-kinase (PI3K), mitogen-activated protein kinase (MAPK) and nuclear factor-kappaB (NF-kappaB), leading to cell differentiation, survival, proliferation, degranulation and chemotaxis. Inhibitors targeted at different enzyme molecules of the tyrosine kinase signaling cascade might afford therapeutic potential for asthma. Anti-inflammatory effects of pharmacological agents targeted at tyrosine kinases, Syk, Itk, signal transducer and activator of transcription-1, NF-kappaB, GATA3, EGFR, PI3K, MEK1/2, p38 MAPK and JNK have been reported in animal models of allergic airway inflammation. Therefore, development of inhibitors targeted at the tyrosine kinase signaling cascade is an attractive strategy for the treatment of asthma.

A network of transcription factors (TFs) determines cell identity, but identity can be altered by overexpressing a combination of TFs. However, choosing and verifying combinations of TFs for specific cell differentiation have been daunting due to the large number of possible combinations of ∼2,000 TFs. Here, we report the identification of individual TFs for lineage-specific cell differentiation based on the correlation matrix of global gene expression profiles. The overexpression of identified TFs-Myod1, Mef2c, Esx1, Foxa1, Hnf4a, Gata2, Gata3, Myc, Elf5, Irf2, Elf1, Sfpi1, Ets1, Smad7, Nr2f1, Sox11, Dmrt1, Sox9, Foxg1, Sox2, or Ascl1-can direct efficient, specific, and rapid differentiation into myocytes, hepatocytes, blood cells, and neurons. Furthermore, transfection of synthetic mRNAs of TFs generates their appropriate target cells. These results demonstrate both the utility of this approach to identify potent TFs for cell differentiation, and the unanticipated capacity of single TFs directly guides differentiation to specific lineage fates.

The Polycomb group (PcG) gene products regulate the maintenance of the homeobox gene expression in Drosophila and vertebrates and also the cell cycle progression in thymocytes and Th2 cell differentiation in mature T cells. We herein studied the role of PcG gene bmi-1 product in Th1/Th2 cell differentiation and found that Bmi-1 facilitates Th2 cell differentiation in a Ring finger-dependent manner. Biochemical studies indicate that Bmi-1 interacts with GATA3 in T cells, which is dependent on the Ring finger of Bmi-1. The overexpression of Bmi-1 resulted in a decreased ubiquitination and an increased protein stability of GATA3. In bmi-1-deficient Th cells, the levels of Th2 cell differentiation decreased as the degradation and ubiquitination on GATA3 increased. Therefore, Bmi-1 plays a crucial role in the control of Th2 cell differentiation in a Ring finger-dependent manner by regulating GATA3 protein stability.

Success in treating severe sepsis will require relevant tools to monitor the patient immunoinflammatory status. This study aimed to investigate the feasibility of measuring a panel of immunological mediator mRNAs in whole blood and to study their prognostic values in septic shock patients. At the onset of shock, compared to healthy volunteers, mRNA levels in septic shock patients were increased for IL-10, IL-1beta, and high mobility group B1 (HMGB1) and decreased for transforming growth factor beta 1, the Th1, and Th2 transcription factors, T-bet and GATA-3, respectively. Single parameter analysis highlighted an increased expression of IL-10 and HMGB1 mRNA in nonsurvivors and a significant rise over time of GATA3 in survivors. Combining the expression levels of four genes, hierarchical cluster analysis showed that up to 95% of the patients with a similar outcome displayed transcriptional similarities. These results illustrate both the potential of whole blood mRNA quantification assays and the interest of a multiparametric strategy to better stratify septic patients.

The Th2 locus control region (LCR) has been shown to be important in efficient and coordinated cytokine gene regulation during Th2 cell differentiation. However, the molecular mechanism for this is poorly understood. To study the molecular mechanism of the Th2 LCR, we searched for proteins binding to it. We discovered that transcription factor YY1 bound to the LCR and the entire Th2 cytokine locus in a Th2-specific manner. Retroviral overexpression of YY1 induced Th2 cytokine expression. CD4-specific knockdown of YY1 in mice caused marked reduction in Th2 cytokine expression, repressed chromatin remodeling, decreased intrachromosomal interactions, and resistance in an animal model of asthma. YY1 physically associated with GATA-binding protein-3 (GATA3) and is required for GATA3 binding to the locus. YY1 bound to the regulatory elements in the locus before GATA3 binding. Thus, YY1 cooperates with GATA3 and is required for regulation of the Th2 cytokine locus and Th2 cell differentiation.

GATA binding protein 3 (Gata3) is a GATA family transcription factor that controls differentiation of naïve CD4 T cells into T helper 2 (Th2) cells. However, it is unknown how Gata3 simultaneously activates Th2-specific genes while repressing those of other Th lineages. Here we show that chromodomain helicase DNA-binding protein 4 (Chd4) forms a complex with Gata3 in Th2 cells that both activates Th2 cytokine transcription and represses the Th1 cytokine IFN-γ. We define a Gata3/Chd4/p300 transcriptional activation complex at the Th2 cytokine loci and a Gata3/Chd4-nucleosome remodeling histone deacetylase repression complex at the Tbx21 locus in Th2 cells. We also demonstrate a physiological role for Chd4 in Th2-dependent inflammation in an in vivo model of asthmatic inflammation. Thus, Gata3/Chd4 forms functionally distinct complexes, which mediate both positive and negative gene regulation to facilitate Th2 cell differentiation.

A well-known association between vitamin D(3) and infection with Mycobacterium tuberculosis has previously been reported, but little is known regarding the underlying mechanisms. We have investigated how 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] affects the proinflammatory cytokine production induced by M. tuberculosis. Furthermore, we explored whether 1,25(OH)(2)D(3) influence the production of the protective antimycobacterial peptide cathelicidin. Upon in vitro stimulation with M. tuberculosis, 1,25(OH)(2)D(3) induced a dose-dependent down-regulation of IL-6, TNFα and IFNγ, while increasing the production of IL-10 in culture supernatant as well as cathelicidin mRNA expression. This effect on cytokine response was not due to modulation of T-helper cell differentiation, as T-bet, GATA3, Foxp3 and ROR-γt mRNA expression remained unaffected. Similarly, 1,25(OH)(2)D(3) did not affect suppressor of cytokine signaling (SOCS)1 and SOCS3 mRNA expression. The mechanism whereby 1,25(OH)(2)D(3) inhibited the proinflammatory cytokine response was through reduced expression of the pattern recognition receptors (PRR) - TLR2, TLR4, Dectin-1 and mannose receptor, whose mRNA and protein expression were both reduced. The suppression of PRRs could be restored by a VDR antagonist. Upon M. tuberculosis stimulation, 1,25(OH)(2)D(3) modulates the balance in cytokine production towards an anti-inflammatory profile by repression of TLR2, TLR4, Dectin-1 and mannose receptor expression, while increasing cathelicidin production. These two effects may have beneficial consequences, by reducing the collateral tissue damage induced by proinflammatory cytokines, while the antibacterial effects of cathelicidin are enhanced.

Estrogen receptor (ER)alpha is a critical target of therapeutic strategies to control the proliferation of hormone-dependent breast cancers. Preferred clinical options have significant adverse side effects that can lead to treatment resistance due to the persistence of active estrogen receptors. We have established the cellular mechanism by which indole-3-carbinol (I3C), a promising anticancer phytochemical from Brassica vegetables, ablates ERalpha expression, and we have uncovered a critical role for the GATA3 transcription factor in this indole-regulated cascade. I3C-dependent activation of the aryl hydrocarbon receptor (AhR) initiates Rbx-1 E3 ligase-mediated ubiquitination and proteasomal degradation of ERalpha protein. I3C inhibits endogenous binding of ERalpha with the 3'-enhancer region of GATA3 and disrupts endogenous GATA3 interactions with the ERalpha promoter, leading to a loss of GATA3 and ERalpha expression. Ectopic expression of GATA3 has no effect on I3C-induced ERalpha protein degradation but does prevent I3C inhibition of ERalpha promoter activity, demonstrating the importance of GATA3 in this I3C-triggered cascade. Our preclinical results implicate I3C as a novel anticancer agent in human cancers that coexpress ERalpha, GATA3, and AhR, a combination found in a large percentage of breast cancers but not in other critical ERalpha target tissues essential to patient health.

BACKGROUND

We hypothesised that differences in microRNA expression profiles contribute to the contrasting natural history and clinical outcome of the two most common types of malignant germ cell tumour (GCT), yolk sac tumours (YSTs) and germinomas.

RESULTS

By direct comparison, using microarray data for paediatric GCT samples and published qRT-PCR data for adult samples, we identified microRNAs significantly up-regulated in YSTs (n = 29 paediatric, 26 adult, 11 overlapping) or germinomas (n = 37 paediatric). By Taqman qRT-PCR we confirmed differential expression of 15 of 16 selected microRNAs and further validated six of these (miR-302b, miR-375, miR-200b, miR-200c, miR-122, miR-205) in an independent sample set. Interestingly, the miR-302 cluster, which is over-expressed in all malignant GCTs, showed further over-expression in YSTs versus germinomas, representing six of the top eight microRNAs over-expressed in paediatric YSTs and seven of the top 11 in adult YSTs. To explain this observation, we used mRNA expression profiles of paediatric and adult malignant GCTs to identify 10 transcription factors (TFs) consistently over-expressed in YSTs versus germinomas, followed by linear regression to confirm associations between TF and miR-302 cluster expression levels. Using the sequence motif analysis environment iMotifs, we identified predicted binding sites for four of the 10 TFs (GATA6, GATA3, TCF7L2 and MAF) in the miR-302 cluster promoter region. Finally, we showed that miR-302 family over-expression in YST is likely to be functionally significant, as mRNAs down-regulated in YSTs were enriched for 3' untranslated region sequences complementary to the common seed of miR-302a~miR-302d. Such mRNAs included mediators of key cancer-associated processes, including tumour suppressor genes, apoptosis regulators and TFs.

CONCLUSIONS

Differential microRNA expression is likely to contribute to the relatively aggressive behaviour of YSTs and may enable future improvements in clinical diagnosis and/or treatment.

Viperin (virus inhibitory protein, endoplasmic reticulum [ER]-associated, interferon-inducible) has been identified as a highly inducible ER protein that has antiviral activity. Here, we characterized the phenotype of mice deficient in viperin and examined the biological function of viperin in peripheral T-cell activation and differentiation. Splenic CD4(+) T cells deficient in viperin exhibited normal anti-T-cell receptor (TCR)-induced proliferation and IL-2 production, but produced significantly less T helper 2 (Th2) cytokines, including IL-4, IL-5, and IL-13, in association with impaired GATA3 activation, after stimulation with anti-CD3 antibody, which was not restored upon costimulation with anti-CD28. Th2 differentiation of viperin-deficient naive T cells was also impaired in the presence of strong TCR signaling and minimum IL-4, but not under optimal Th2-skewed conditions. In parallel, viperin-deficient T cells showed decreases in NF-kappaB1/p50 and AP-1/JunB DNA binding activities after TCR engagement. Thus, viperin facilitates TCR-mediated GATA-3 activation and optimal Th2 cytokine production by modulating NF-kappaB and AP-1 activities.

Breast cancers exhibit genome-wide aberrant DNA methylation patterns. To investigate how these affect the transcriptome and which changes are linked to transformation or progression, we apply genome-wide expression-methylation quantitative trait loci (emQTL) analysis between DNA methylation and gene expression. On a whole genome scale, in cis and in trans, DNA methylation and gene expression have remarkably and reproducibly conserved patterns of association in three breast cancer cohorts (n = 104, n = 253 and n = 277). The expression-methylation quantitative trait loci associations form two main clusters; one relates to tumor infiltrating immune cell signatures and the other to estrogen receptor signaling. In the estrogen related cluster, using ChromHMM segmentation and transcription factor chromatin immunoprecipitation sequencing data, we identify transcriptional networks regulated in a cell lineage-specific manner by DNA methylation at enhancers. These networks are strongly dominated by ERα, FOXA1 or GATA3 and their targets were functionally validated using knockdown by small interfering RNA or GRO-seq analysis after transcriptional stimulation with estrogen.

The differentiation of CD4 helper T cells into specialized effector lineages has provided a powerful model for understanding immune cell differentiation. Distinct lineages have been defined by differential expression of signature cytokines and the lineage-specifying transcription factors necessary and sufficient for their production. The traditional paradigm of differentiation towards Th1 and Th2 subtypes driven by T-bet and GATA3, respectively, has been extended to incorporate additional T cell lineages and transcriptional regulators. Technological advances have expanded our view of these lineage-specifying transcription factors to the whole genome and revealed unexpected interplay between them. From these data, it is becoming clear that lineage specification is more complex and plastic than previous models might have suggested. Here, we present an overview of the different forms of transcription factor interplay that have been identified and how T cell phenotypes arise as a product of this interplay within complex regulatory networks. We also suggest experimental strategies that will provide further insight into the mechanisms that underlie T cell lineage specification and plasticity.