The secreted protein S100A7 (psoriasin) is induced by telomere dysfunction in human keratinocytes independently of a DNA damage response and cell cycle regulators

Senomorphic activity of a combination of niacinamide and hyaluronic acid: correlation with clinical improvement of skin aging

Intrinsic and extrinsic factors, including lifestyle and sun exposure, can contribute to cell senescence, which impairs skin homeostasis, that may in turn lead to skin aging. Senescent cells have a specific secretome, called the senescence-associated secretory phenotype (SASP) that includes MMPs, CXCLs and S100A8/9. Reducing the SASP with senotherapeutics is a promising strategy to reduce skin aging. Here we evaluated the effect of a formula containing niacinamide and hyaluronic acid, which are known to limit senescence and skin aging. We conducted three different studies. (1) Ex vivo explants treated with the formula had more collagen and glycosaminoglycan. (2) In a clinical trial with forty-four women, two months of treatment improved fine lines, wrinkles, luminosity, smoothness, homogeneity, and plumpness. (3) In a third study on thirty women, we treated one arm for two months and took skin biopsies to study gene expression. 101 mRNAs and 13 miRNAs were differentially expressed. We observed a likely senomorphic effect, as there was a decrease in many SASP genes including MMP12 and CXCL9 and a significant downregulation of autocrine signaling genes: S100A8 and S100A9. These pharmaco-clinical results are the first to demonstrate the senomorphic properties of an effective anti-aging formula in skin.

The S100A7 nuclear interactors in autoimmune diseases: a coevolutionary study in mammals

S100A7, a member of the S100A family of Ca²⁺-binding proteins, is considered a key effector in immune response. In particular, S100A7 dysregulation has been associated with several diseases, including autoimmune disorders. At the nuclear level, S100A7 interacts with several protein-binding partners which are involved in transcriptional regulation and DNA repair. By using the BioGRID and GAAD databases, S100A7 nuclear interactors with a putative involvement in autoimmune diseases were retrieved. We selected fatty acid-binding protein 5 (FABP5), autoimmune regulator (AIRE), cystic fibrosis transmembrane conductance regulator (CFTR), chromodomain helicase DNA-binding protein 4 (CHD4), epidermal growth factor receptor (EGFR), estrogen receptor 1 (ESR1), histone deacetylase 2 (HDAC2), v-myc avian myelocytomatosis viral oncogene homolog (MYC), protection of telomeres protein 1 (POT1), telomeric repeat-binding factor (NIMA-interacting) 1 (TERF1), telomeric repeat-binding factor 2 (TERF2), and Zic family member 1 (ZIC1). Linear correlation coefficients between interprotein distances were calculated with MirrorTree. Coevolution clusters were also identified with the use of a recent version of the Blocks in Sequences (BIS2) algorithm implemented in the BIS2Analyzer web server. Analysis of pair positions identified interprotein coevolving clusters between S100A7 and the binding partners CFTR and TERF1. Such findings could guide further analysis to better elucidate the function of S100A7 and its binding partners and to design drugs targeting for these molecules in autoimmune diseases.

Fluid Flow Stimulation Modulates Expression of S100 Genes in Normal Breast Epithelium and Breast Cancer

INTRODUCTION

S100 proteins are intracellular calcium ion sensors that participate in cellular processes, some of which are involved in normal breast functioning and breast cancer development. Despite several S100 genes being overexpressed in breast cancer, their roles during disease development remain elusive. Human mammary epithelial cells (HMECs) can be exposed to fluid shear stresses and implications of such interactions have not been previously studied. The goal of this study was to analyze expression profiles of S100 genes upon exposing HMECs to fluid flow.

METHODS

HMECs and breast cancer cell lines were exposed to fluid flow in a parallel-plate bioreactor system. Changes in gene expression were quantified using microarrays and qPCR, gene-gene interactions were elucidated using network analysis, and key modified genes were examined in three independent clinical datasets.

RESULTS

S100 genes were among the most upregulated genes upon flow stimulation. Network analysis revealed interactions between upregulated transcripts, including interactions between S100P, S100PBP, S100A4, S100A7, S100A8 and S100A9. Overexpression of S100s was also observed in patients with early stage breast cancer compared to normal breast tissue, and in most breast cancer patients. Finally, survival analysis revealed reduced survival times for patients with elevated expression of S100A7 and S100P.

CONCLUSION

This study shows that exposing HMECs to fluid flow upregulates genes identified clinically to be overexpressed during breast cancer development, including S100A7 and S100P. These findings are the first to show that S100 genes are flow-responsive and might be participating in a fundamental adaptation pathway in normal tissue that is also active in breast cancer.

Desmoglein-3 induces YAP phosphorylation and inactivation during collective migration of oral carcinoma cells

Alterations of the Hippo-YAP pathway are potential targets for oral squamous cell carcinoma (OSCC) therapy, but heterogeneity in this pathway could be responsible for therapeutic resistance. We analysed the Hippo-YAP signatures in a cohort of characterised keratinocyte cell lines derived from the mouth floor and buccal mucosa from different stages of OSCC tumour progression and focused on the specific role of YAP on invasive and metastatic potential. We confirmed heterogeneity in the Hippo-YAP pathway in OSCC lines, including overexpression of YAP1, WWTR1 (often referred to as TAZ) and the major Hippo signalling components, as well as the variations in the genes encoding the intercellular anchoring junctional proteins, which could potentially regulate the Hippo pathway. Specifically, desmoglein-3 (DSG3) exhibits a unique and mutually exclusive regulation of YAP via YAP phosphorylation during the collective migration of OSCC cells. Mechanistically, such regulation is associated with inhibition of phosphorylation of epidermal growth factor receptor (EGFR) (S695/Y1086) and its downstream effectors heat shock protein beta-1 (Hsp27) (S78/S82) and transcription factor AP-1 (c-Jun) (S63), leading to YAP phosphorylation coupled with its cytoplasmic translocation and inactivation. Additionally, OSCC lines display distinct phenotypes of YAP dependency or a mixed YAP and TAZ dependency for cell migration, and present distinct patterns in YAP abundance and activity, with the latter being associated with YAP nuclear localisation. In conclusion, this study has provided evidence for a newly identified paradigm in the Hippo-YAP pathway and suggests a new regulation mechanism involved in the control of collective migration in OSCC cells.

Gene Expression Profile in Immortalized Human Periodontal Ligament Fibroblasts Through hTERT Ectopic Expression: Transcriptome and Bioinformatic Analysis

Human periodontal ligament fibroblast (hPLF) cells play an important role in maintaining oral cavity homeostasis with special function in tissue regeneration and maintenance of dental alveoli. Although their primary cell cultures are considered a good experimental model with no genetic changes, the finite life span may limit some experimental designs. The immortalization process increases cell life span but may cause genetic changes and chromosomal instability, resulting in direct effects on physiological cell responses. In this way, we aimed to investigate the global gene expression of hPLFs after the immortalization process by the ectopic expression of the catalytic subunit of the enzyme telomerase reverse transcriptase (hTERT) through transcriptome analysis. The embryonic origin of the primary culture of hPLF cells and immortalized hPLF-hTERT was also tested by vimentin staining, hTERT synthesis evaluated by indirect immunocytochemistry, analysis of cell proliferation, and morphology. The results indicated that hPLFs and hPLF-hTERT were positive for vimentin. On the 20th cell passage, hPLFs were in senescence, while hPLF-hTERT maintained their proliferation and morphology characteristics. At the same passage, hPLF-hTERT presented a significant increase in hTERT synthesis, but transcriptome did not reveal overexpression of the hTERT gene. Fifty-eight genes had their expression altered (11 upregulated and 47 downregulated) with the absence of changes in the key genes related to these cell types and in the main cancer-associated genes. In addition, the increase in hTERT protein expression without the overexpression of its gene indicates posttranscriptional level regulation. Successful immortalization of hPLFs through the ectopic expression of hTERT encourages further studies to design experimental protocols to investigate clinical questions from a translational perspective.

Targeting AXL and RAGE to prevent geminin overexpression-induced triple-negative breast cancer metastasis

Dissemination of metastatic precursors from primaries is the primary reason for patient death. Dissemination encompasses tumor cells invasion of stroma, followed by intravasation through the endothelium barrier into the bloodstream. Here, we describe how geminin-overexpressing tumor cells acquire dissemination ability. Acetylated HMGB1 (Ac-HMGB1) secreted by geminin-overexpressing cells activates RAGE and CXCR4 expression on mesenchymal stem cells (MSCs) located in tumor stroma. Through secreting CXCL12, geminin-overexpressing cells recruit these CXCR4⁺-MSCs into the tumor. Within the tumor, MSCs differentiate into S100A4-secreting cancer-associated fibroblasts (CAFs). S100A4, in a reciprocal manner, activates geminin-overexpressing cells to secrete CCL2 that recruits M0-macrophages from the stroma into the tumor. Within the tumor, CCL2 polarizes M0-macrophages into Gas6-secreting M2-tumor-associated macrophages (M2-TAMs). In concert, geminin-overexpression, S100A4/RAGE and Gas6/AXL signaling promote the invasive and intravasation abilities in geminin-overexpressing cells through exacerbating their stemness and epithelial-to-mesenchymal phenotypes and enhancing expression and functional interaction of CD151 and α3β1-integrin in geminin-overexpressing cells. Tumors formed following injection of geminin-overexpressing cells admixed with MSCs/CAFs grew faster, metastasized earlier, especially to lungs, and were extremely sensitive to anti-c-Abl, anti-RAGE, and anti-AXL drugs. These data support an intrinsic ability in geminin-overexpressing tumor cells to promote their metastatic potential through recruitment and bi-directional interactions with MSCs/CAFs and M2-TAMs.