Tidal Heating: Lessons from Io and the Jovian System (Report from the KISS Workshop)

Summary of the Keck Institute for Space Studies workshop entitled "Tidal Heating: Lessons from Io and the Jovian System," held on October 15-19, 2018

Inhibition of CCN6 (WISP3) expression promotes neoplastic progression and enhances the effects of insulin-like growth factor-1 on breast epithelial cells

INTRODUCTION: CCN6/WISP3 belongs to the CCN (Cyr61, CTGF, Nov) family of genes that contains a conserved insulin-like growth factor (IGF) binding protein motif. CCN6 is a secreted protein lost in 80% of the aggressive inflammatory breast cancers, and can decrease mammary tumor growth in vitro and in vivo. We hypothesized that inhibition of CCN6 might result in the loss of a growth regulatory function that protects mammary epithelial cells from the tumorigenic effects of growth factors, particularly IGF-1. METHOD: We treated human mammary epithelial (HME) cells with a CCN6 hairpin short interfering RNA. RESULTS: CCN6-deficient cells showed increased motility and invasiveness, and developed features of epithelial-mesenchymal transition (EMT). Inhibition of CCN6 expression promoted anchorage-independent growth of HME cells and rendered them more responsive to the growth effects of IGF-1, which was coupled with the increased phosphorylation of IGF-1 receptor and insulin receptor substrate-1 (IRS-1). CONCLUSION: Specific stable inhibition of CCN6 expression in HME cells induces EMT, promotes anchorage-independent growth, motility and invasiveness, and sensitizes mammary epithelial cells to the growth effects of IGF-1

Expression of CCN family of genes in human skin in vivo and alterations by solar-simulated ultraviolet irradiation

The CCN family of proteins is involved in diverse biological functions such as cell growth, adhesion, migration, angiogenesis, and regulation of extracellular matrix. We have investigated expression of CCN family genes and alternations induced by solar-simulated ultraviolet irradiation in human skin in vivo. Transcripts of all six CCN genes were expressed in human skin in vivo. CCN5 was most abundantly expressed followed by CCN2>CCN3>CCN1>CCN4>CCN6. Solar-simulated ultraviolet irradiation increased mRNA expression of CCN1 and CCN2. In contrast, mRNA levels of CCN3, CCN4, CCN5, and CCN6, were reduced. Knowledge gained from this study provides the foundation to explore the functional roles of CCN gene products in cutaneous biology and responses to solar ultraviolet irradiation

No phosphine in the atmosphere of Venus

The detection of phosphine (PH₃) has been recently reported in the atmosphere of Venus employing mm-wave radio observations (Greaves et at. 2020). We here demonstrate that the observed PH₃ feature with JCMT can be fully explained employing plausible mesospheric SO₂ abundances (~100 ppbv as per the SO₂ profile given in their figure 9), while the identification of PH₃ in the ALMA data should be considered invalid due to severe baseline calibration issues. We demonstrate this by independently calibrating and analyzing the ALMA data using different interferometric analysis tools, in which we observe no PH₃ in all cases. Furthermore, for any PH₃ signature to be produced in either ALMA or JCMT spectra, PH₃ needs to present at altitudes above 70 km, in stark disagreement with their photochemical network. We ultimately conclude that this detection of PH₃ in the atmosphere of Venus is not supported by our analysis of the data

Update on inflammatory breast cancer

Inflammatory breast cancer (IBC) is both the least frequent and the most severe form of epithelial breast cancer. The diagnosis is based on clinical inflammatory signs and is reinforced by pathological findings. Significant progress has been made in the management of IBC in the past 20 years. Yet survival among IBC patients is still only one-half that among patients with non-IBC. Identification of the molecular determinants of IBC would probably lead to more specific treatments and to improved survival. In the present article we review recent advances in the molecular pathogenesis of IBC. A more comprehensive view will probably be obtained by pan-genomic analysis of human IBC samples, and by functional in vitro and in vivo assays. These approaches may offer better patient outcome in the near future

Validation of a Tissue Microarray to Study Differential Protein Expression in Inflammatory and Non-Inflammatory Breast Cancer

Aims. Inflammatory breast cancer (IBC) is an aggressive subtype of breast cancer with poor prognosis. The mechanisms responsible for the aggressive clinical evolution are incompletely understood. We constructed a tissue microarray (TMA) and validated its use in translational IBC research. Differential expression of proteins that might play a role in causing the IBC phenotype was studied.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44222/1/10549_2004_Article_5256693.pd

Mesenchymal Stem Cells Promote Mammosphere Formation and Decrease E-Cadherin in Normal and Malignant Breast Cells

Normal and malignant breast tissue contains a rare population of multi-potent cells with the capacity to self-renew, referred to as stem cells, or tumor initiating cells (TIC). These cells can be enriched by growth as "mammospheres" in three-dimensional cultures.We tested the hypothesis that human bone-marrow derived mesenchymal stem cells (MSC), which are known to support tumor growth and metastasis, increase mammosphere formation.We found that MSC increased human mammary epithelial cell (HMEC) mammosphere formation in a dose-dependent manner. A similar increase in sphere formation was seen in human inflammatory (SUM149) and non-inflammatory breast cancer cell lines (MCF-7) but not in primary inflammatory breast cancer cells (MDA-IBC-3). We determined that increased mammosphere formation can be mediated by secreted factors as MSC conditioned media from MSC spheroids significantly increased HMEC, MCF-7 and SUM149 mammosphere formation by 6.4 to 21-fold. Mammospheres grown in MSC conditioned media had lower levels of the cell adhesion protein, E-cadherin, and increased expression of N-cadherin in SUM149 and HMEC cells, characteristic of a pro-invasive mesenchymal phenotype. Co-injection with MSC in vivo resulted in a reduced latency time to develop detectable MCF-7 and MDA-IBC-3 tumors and increased the growth of MDA-IBC-3 tumors. Furthermore, E-cadherin expression was decreased in MDA-IBC-3 xenografts with co-injection of MSC.MSC increase the efficiency of primary mammosphere formation in normal and malignant breast cells and decrease E-cadherin expression, a biologic event associated with breast cancer progression and resistance to therapy

NF-κB activation in inflammatory breast cancer is associated with oestrogen receptor downregulation, secondary to EGFR and/or ErbB2 overexpression and MAPK hyperactivation

Activation of NF-κB in inflammatory breast cancer (IBC) is associated with loss of estrogen receptor (ER) expression, indicating a potential crosstalk between NF-κB and ER. In this study, we examined the activation of NF-κB in IBC and non-IBC with respect to ER and EGFR and/or ErbB2 expression and MAPK hyperactivation. A qRT–PCR based ER signature was evaluated in tumours with and without transcriptionally active NF-κB, as well as correlated with the expression of eight NF-κB target genes. Using a combined ER/NF-κB signature, hierarchical clustering was executed. Hyperactivation of MAPK was investigated using a recently described MAPK signature (Creighton et al, 2006), and was linked to tumour phenotype, ER and EGFR and/or ErbB2 overexpression. The expression of most ER-modulated genes was significantly elevated in breast tumours without transcriptionally active NF-κB. In addition, the expression of most ER-modulated genes was significantly anticorrelated with the expression of most NF-κB target genes, indicating an inverse correlation between ER and NF-κB activation. Clustering using the combined ER and NF-κB signature revealed one cluster mainly characterised by low NF-κB target gene expression and a second one with elevated NF-κB target gene expression. The first cluster was mainly characterised by non-IBC specimens and IHC ER+ breast tumours (13 out of 18 and 15 out of 18 respectively), whereas the second cluster was mainly characterised by IBC specimens and IHC ER− breast tumours (12 out of 19 and 15 out of 19 respectively) (Pearson χ2, P<0.0001 and P<0.0001 respectively). Hyperactivation of MAPK was associated with both ER status and tumour phenotype by unsupervised hierarchical clustering using the MAPK signature and was significantly reflected by overexpression of EGFR and/or ErbB2. NF-κB activation is linked to loss of ER expression and activation in IBC and in breast cancer in general. The inverse correlation between NF-κB activation and ER activation is due to EGFR and/or ErbB2 overexpression, resulting in NF-κB activation and ER downregulation

Breast cancer stem cells: tools and models to rely on

There is increasing evidence for the "cancer stem cell (CSC) hypothesis", which holds that cancers are driven by a cellular component that has stem cell properties, including self-renewal, tumorigenicity and multi-lineage differentiation capacity. Researchers and oncologists see in this model an explanation as to why cancer may be so difficult to cure, as well as a promising ground for novel therapeutic strategies. Given the specific stem cell features of self-renewal and differentiation, which drive tumorigenesis and contribute to cellular heterogeneity, each marker and assay designed to isolate and characterize CSCs has to be functionally validated. In this review, we survey tools and markers available or promising to identify breast CSCs. We review the main models used to study breast CSCs and how they challenge the CSC hypothesis