Influence of gender on epithelial host defence peptide gene expression under non-infected and infected conditions: A basic medical research study.

Bacterial resistance against conventional antibiotics is increasing. This introduces challenges, for example, in the treatment of infected surgical wounds. Host defence peptides (HDP), which are endogenous peptide antibiotics, show broad-spectrum antimicrobial effectiveness. They protect the organism against pathological microorganisms. Synthetic HDP might supplement or even become alternatives to conventional antibiotics. Knowledge of their quantities under physiological and pathophysiological conditions is therefore required. The influence of gender on HDP expression is unknown. This study evaluates whether gender influences HDP expression in infected or healthy epithelium. Expression levels of HDP human beta-defensin (hBD)-1, -2 and -3 and psoriasin (S100A7) were analysed, by using real-time polymerase chain reaction, in samples of epithelium from infected surgical wounds (n = 20) and healthy epithelium (n = 14) from the neck in a basic medical research study (analytic observational design). The results demonstrated a significantly elevated expression of hBD-2, hBD-3 and psoriasin (P = 0.001 each) in infected epithelium compared with healthy epithelium. No difference in HDP expression levels was evident between samples from female and male patients, either within infected samples or within healthy epithelium samples. Thus, gender does not affect the cutaneous expression of the investigated HDP. This is fundamental knowledge for the study and potential use of HDP derivates as alternative antibiotic substances.

Platelet-released growth factors induce psoriasin in keratinocytes: Implications for the cutaneous barrier.

Millions of patients around the world suffer minor or major extremity amputation due to progressive wound healing complications of chronic or infected wounds, the therapy of which remains a challenge. One emerging therapeutic option for the treatment of these complicated wounds is the local application of an autologous thrombocytes concentrate lysate (e.g. platelet-released growth factors ((PRGF)) or Vivostat PRF®) that contains a multitude of chemokines, cytokines and growth factors and is therefore supposed to stimulate the complex wound healing process. Although PRGF and Vivostat PRF® are already used successfully to support healing of chronic, hard-to-heal and infected wounds the underlying molecular mechanisms are not well understood. Psoriasin, also termed S100A7, is a multifunctional antimicrobial protein expressed in keratinocytes and is involved in various processes such as wound-healing, angiogenesis, innate immunity and immune-modulation. In this study, we investigated the influence of PRGF on psoriasin expression in human primary keratinocytes in vitro and the influence of Vivostat PRF® on psoriasin expression in experimentally generated skin wounds in vivo. PRGF treatment of primary keratinocytes caused a significant concentration- and time-dependent increase of psoriasin gene and protein expression in vitro that were partially mediated by the epidermal growth factor receptor (EGFR) and the interleukin-6 receptor (IL-6R). In accordance with these cell culture data, Vivostat PRF® induced a significant psoriasin gene and protein expression when applied to artificially generated skin wounds in vivo. The observed psoriasin induction in keratinocytes may contribute to the wound healing-promoting effects of therapeutically used thrombocyte concentrate lysates.

S100A7 promotes the migration, invasion and metastasis of human cervical cancer cells through epithelial-mesenchymal transition.

S100A7 is an EF-hand calcium-binding protein that has been suggested to be implicated in cell proliferation, migration, invasion and tumor metastasis. However, its role in cervical cancer has not yet been fully clarified. The present study used immunohistochemistry analysis of S100A7 in clinical specimens of cervical cancer to show that S100A7 expression was significantly upregulated in cervical cancer tissues compared with normal cervical tissues and S100A7 expression in high grade cervical intraepithelial neoplasm (CIN) was significantly higher than cervical cancer. Statistical analysis showed that S100A7 expression was associated with tumor grade (P <0.01) and lymph node metastasis (P <0.05). Functional studies showed that overexpression of S100A7 in cervical cancer cells promoted migration, invasion and metastasis of cervical cancer cells without influencing cell proliferation. Furthermore, S100A7 was found to be secreted into the conditioned media and extracellular S100A7 enhanced cell migration and invasion. Mechanistically, S100A7 bound to RAGE and activated ERK signaling pathway. And S100A7 enhanced cell mesenchymal properties and induced epithelial-mesenchymal transition. In summary, these data reveal a crucial role for S100A7 in regulating cell migration, invasion, metastasis and EMT of cervical cancer and suggest that targeting S100A7 may offer a new targeted strategy for cervical cancer.

S100A7 promotes lung adenocarcinoma to squamous carcinoma transdifferentiation, and its expression is differentially regulated by the Hippo-YAP pathway in lung cancer cells.

Our previous study revealed that S100A7 was selectively expressed in lung squamous cell carcinoma tissues but not in adenocarcinoma. Thus far, the functions of S100A7 in lung cancer have remained largely unknown. Here, we reveal that S100A7 overexpression facilitates the transdifferentiation from adenocarcinoma (ADC) to squamous carcinoma (SCC) in several lung cancer cells, which is confirmed by an increase in DNp63 expression and a decrease in thyroid transcription factor 1 (TTF1) and aspartic proteinase napsin (napsin A) expression. Further study finds that activation of the Hippo pathway induces S100A7 expression and further confirms that nuclear YAP acts as a repressor of S100A7 in H292 cells. Subsequently, we verify that TEAD1 is required for YAP transcriptional repression of S100A7. More importantly, we determine that S100A7 overexpression partially rescues lung ADC to SCC transdifferentiation inhibited by YAP overexpression in all tested cells, suggesting that S100A7 and YAP have the opposite effects on lung ADC to SCC conversion. Taken together, our study demonstrates for the first time that S100A7 not only functions as a facilitator of adenous-squamous carcinoma phenotypic transition in lung cancer cells but also that its expression is differentially regulated by the Hippo-YAP pathway.

S100A7 induction is repressed by YAP via the Hippo pathway in A431 cells.

YAP is an oncogenic transcriptional co-activator and is inhibited by the Hippo pathway. Recent studies have revealed that YAP is also a sensor of cell morphology and cell density and can be phosphorylated by cytoskeleton reorganization. Our previous study demonstrated that S100A7 was upregulated in several squamous cell carcinoma (SCC) specimens and was dramatically induced in SCC cells by suspension and dense culture as well as in xenografts. However, little is known about how S100A7 induction occurs in cancer cells. Here, we identify that S100A7 induction is accompanied by YAP phosphorylation in both suspended and dense A431 cells. This correlation reverses after recovery of cell attachment or relief from dense culture. Further examination finds that S100A7 induction is repressed by nuclear YAP, which is further validated by activation or inhibition of the Hippo pathway via loss- and/or gain-of- LATS1 and MST1 function. Strikingly, disruption of the F-actin promotes S100A7 expression via YAP by activation of the Hippo pathway. Furthermore, we demonstrate that repression of S100A7 by YAP required TEAD1 transcriptional factor. Taken together, our findings demonstrate for the first time that S100A7 is repressed by YAP via the Hippo pathway.