Prep1.1 has essential genetic functions in hindbrain development and cranial neural crest cell differentiation

In this study we analysed the function of the Meinox gene prep1.1 during zebrafish development. Meinox proteins form heterotrimeric complexes with Hox and Pbx members, increasing the DNA binding specificity of Hox proteins in vitro and in vivo. However, a role for a specific Meinox protein in the regulation of Hox activity in vivo has not been demonstrated. In situ hybridization showed that prep1.1 is expressed maternally and ubiquitously up to 24 hours post-fertilization (hpf), and restricted to the head from 48 hpf onwards. Morpholino-induced prep1.1 loss-of-function caused significant apoptosis in the CNS. Hindbrain segmentation and patterning was affected severely, as revealed by either loss or defective expression of several hindbrain markers ( foxb1.2/mariposa , krox20 , pax2.1 and pax6.1 ), including anteriorly expressed Hox genes ( hoxb1a , hoxa2 and hoxb2 ), the impaired migration of facial nerve motor neurons, and the lack of reticulospinal neurons (RSNs) except Mauthner cells. Furthermore, the heads of prep1.1 morphants lacked all pharyngeal cartilages. This was not caused by the absence of neural crest cells or their impaired migration into the pharyngeal arches, as shown by expression of dlx2 and snail1 , but by the inability of these cells to differentiate into chondroblasts. Our results indicate that prep1.1 has a unique genetic function in craniofacial chondrogenesis and, acting as a member of Meinox-Pbc-Hox trimers, it plays an essential role in hindbrain development

Composition and Functional Potential of the Human Mammary Microbiota Prior to and following Breast Tumor Diagnosis

Microbiota studies have reported changes in the microbial composition of the breast upon cancer development. However, results are inconsistent and limited to the later phases of cancer development (after diagnosis). We analyzed and compared the resident bacterial taxa of histologically normal breast tissue (healthy, H, n = 49) with those of tissues donated prior to (prediagnostic, PD, n = 15) and after (adjacent normal, AN, n = 49, and tumor, T, n = 46) breast cancer diagnosis (n total = 159). DNA was isolated from tissue samples and submitted for Illumina MiSeq paired-end sequencing of the V3-V4 region of the 16S gene. To infer bacterial function in breast cancer, we predicted the functional bacteriome from the 16S sequencing data using PICRUSt2. Bacterial compositional analysis revealed an intermediary taxonomic signature in the PD tissue relative to that of the H tissue, represented by shifts in Bacillaceae, Burkholderiaceae, Corynebacteriaceae, Streptococcaceae, and Staphylococcaceae. This compositional signature was enhanced in the AN and T tissues. We also identified significant metabolic reprogramming of the microbiota of the PD, AN, and T tissue compared with the H tissue. Further, preliminary correlation analysis between host transcriptome profiling and microbial taxa and genes in H and PD tissues identified altered associations between the human host and mammary microbiota in PD tissue compared with H tissue. These findings suggest that compositional shifts in bacterial abundance and metabolic reprogramming of the breast tissue microbiota are early events in breast cancer development that are potentially linked with cancer susceptibility

A plasma telomeric cell-free DNA level in unaffected women with BRCA1 or/and BRCA2 mutations: a pilot study

Plasma cell-free DNA (cfDNA) is a small DNA fragment circulating in the bloodstream originating from both non-tumor- and tumor-derived cells. A previous study showed that a plasma telomeric cfDNA level decreases in sporadic breast cancer patients compared to controls. Tumor suppressor gene products including BRCA1 and BRCA2 (BRCA1&2) play an important role in telomere maintenance. In this study, we hypothesized that the plasma telomeric cfDNA level is associated with the mutation status of BRCA1&2 genes. To test this hypothesis, we performed plasma telomeric cfDNA quantitative PCR (qPCR)-based assays to compare 28 women carriers of the BRCA1&2 mutation with age-matched controls of 28 healthy women. The results showed that the plasma telomeric cfDNA level was lower in unaffected BRCA1&2 mutation carriers than in age-matched controls from non-obese women (BMI 30). Moreover, the plasma telomeric cfDNA level applied aptly to the Tyrer-Cuzick model in non-obese women. These findings suggest that circulating cfDNA may detect dysfunctional telomeres derived from cells with BRCA1&2 mutations and, therefore, its level is associated with breast cancer susceptibility. This pilot study warrants further investigation to elucidate the implication of plasma telomeric cfDNA levels in relation to cancer and obesity

Erratum to "Evolutionary conserved role of ptf1a in the specification of exocrine pancreatic fates" [Dev. Biol. 268 (2004) 174–184]

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Associations of Genetic Ancestry with Terminal Duct Lobular Unit Involution among Healthy Women

Reduced age-related terminal duct lobular unit (TDLU) involution has been linked to increased breast cancer risk and triple-negative breast cancer. Associations of TDLU involution levels with race and ethnicity remain incompletely explored. Herein, we examined the association between genetic ancestry and TDLU involution in normal breast tissue donated by 2014 healthy women in the United States. Women of African ancestry were more likely than European women to have increased TDLU counts (odds ratio [OR](trend) = 1.36, 95% confidence interval [CI] = 1.07 to 1.74), acini counts per TDLU (OR = 1.47, 95% CI = 1.06 to 2.03), and median TDLU span (OR(trend) = 1.44, 95% CI = 1.08 to 1.91), indicating lower involution, whereas East Asian descendants were associated with decreased TDLU counts (OR(trend) = 0.52, 95% CI = 0.35 to 0.78) after controlling for potential confounders. These associations are consistent with the racial variations in incidence rates of triple-negative breast cancer in the United States and suggest opportunities for future work examining whether TDLU involution may mediate the racial differences in subtype-specific breast cancer risk

Normal Breast-Derived Epithelial Cells with Luminal and Intrinsic Subtype-Enriched Gene Expression Document Interindividual Differences in Their Differentiation Cascade

Cell-type origin is one of the factors that determine molecular features of tumors, but resources to validate this concept are scarce because of technical difficulties in propagating major cell types of adult organs. Previous attempts to generate such resources to study breast cancer have yielded predominantly basal-type cell lines. We have created a panel of immortalized cell lines from core breast biopsies of ancestry-mapped healthy women that form ductal structures similar to normal breast in 3D cultures and expressed markers of major cell types, including the luminal-differentiated cell-enriched ERα-FOXA1-GATA3 transcription factor network. We have also created cell lines from PROCR (CD201)+/EpCAM- cells that are likely the "normal" counterpart of the claudin-low subtype of breast cancers. RNA-seq and PAM50-intrinsic subtype clustering identified these cell lines as the "normal" counterparts of luminal A, basal, and normal-like subtypes and validated via immunostaining with basal-enriched KRT14 and luminal-enriched KRT19. We further characterized these cell lines by flow cytometry for distribution patterns of stem/basal, luminal-progenitor, mature/differentiated, multipotent PROCR+ cells, and organogenesis-enriched epithelial/mesenchymal hybrid cells using CD44/CD24, CD49f/EpCAM, CD271/EpCAM, CD201/EpCAM, and ALDEFLUOR assays and E-cadherin/vimentin double staining. These cell lines showed interindividual heterogeneity in stemness/differentiation capabilities and baseline activity of signaling molecules such as NF-κB, AKT2, pERK, and BRD4. These resources can be used to test the emerging concept that genetic variations in regulatory regions contribute to widespread differences in gene expression in "normal" conditions among the general population and can delineate the impact of cell-type origin on tumor progression.Significance: In addition to providing a valuable resource for the breast cancer research community to investigate cell-type origin of different subtypes of breast cancer, this study highlights interindividual differences in normal breast, emphasizing the need to use "normal" cells from multiple sources as controls to decipher the effects of cancer-specific genomic aberrations

Targeting monocyte chemotactic protein-1 synthesis with bindarit induces tumor regression in prostate and breast cancer animal models

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Multiscale imaging of basal cell dynamics in the functionally mature mammary gland

The mammary epithelium is indispensable for the continued survival of more than 5,000 mammalian species. For some, the volume of milk ejected in a single day exceeds their entire blood volume. Here, we unveil the spatiotemporal properties of physiological signals that orchestrate the ejection of milk from alveolar units and its passage along the mammary ductal network. Using quantitative, multidimensional imaging of mammary cell ensembles from GCaMP6 transgenic mice, we reveal how stimulus evoked Ca oscillations couple to contractions in basal epithelial cells. Moreover, we show that Ca-dependent contractions generate the requisite force to physically deform the innermost layer of luminal cells, compelling them to discharge the fluid that they produced and housed. Through the collective action of thousands of these biological positive-displacement pumps, each linked to a contractile ductal network, milk begins its passage toward the dependent neonate, seconds after the command

Identification and validation of genes with expression patterns inverse to multiple metastasis suppressor genes in breast cancer cell lines

Metastasis suppressor genes (MSGs) have contributed to an understanding of regulatory pathways unique to the lethal metastatic process. When re-expressed in experimental models, MSGs block cancer spread to, and colonization of distant sites without affecting primary tumor formation. Genes have been identified with expression patterns inverse to a single MSG, and found to encode functional, druggable signaling pathways. We now hypothesize that common signaling pathways mediate the effects of multiple MSGs. By gene expression profiling of human MCF7 breast carcinoma cells expressing a scrambled siRNA, or siRNAs to each of 19 validated MSGs (NME1, BRMS1, CD82, CDH1, CDH2, CDH11, CASP8, MAP2K4, MAP2K6, MAP2K7, MAPK14, GSN, ARHGDIB, AKAP12, DRG1, CD44, PEBP1, RRM1, KISS1), we identified genes whose expression was significantly opposite to at least five MSGs. Five genes were selected for further analysis: PDE5A, UGT1A, IL11RA, DNM3 and OAS1. After stable downregulation of each candidate gene in the aggressive human breast cancer cell line MDA-MB-231T, in vitro motility was significantly inhibited. Two stable clones downregulating PDE5A (phosphodiesterase 5A), an enzyme involved in the regulation of cGMP-specific signaling, exhibited no difference in cell proliferation, but reduced motility by 47 and 66 % compared to the empty vector-expressing cells (p = 0.01 and p = 0.005). In an experimental metastasis assay, two shPDE5A-MDA-MB-231T clones produced 47-62 % fewer lung metastases than shRNA-scramble expressing cells (p = 0.045 and p = 0.009 respectively). This study demonstrates that previously unrecognized genes are inversely related to the expression of multiple MSGs, contribute to aspects of metastasis, and may stand as novel therapeutic targets