Epithelial-mesenchymal transition in Bowen's disease when arising de novo and acquiring invasive capacity

LINC00460 Promotes Cutaneous Squamous Cell Carcinoma Progression Through Stabilizing ELAVL1 Protein

Long intergenic noncoding ribonucleic acid (lncRNA) 460 is reportedly associated with carcinogenesis and progression in various types of cancer. However, the mechanisms underlying its action in cutaneous squamous cell carcinoma (CSCC) remain unclear. LINC00460 mRNA expression was analysed using data from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Cell growth, migration, and invasion were evaluated using Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), transwell migration and invasion assays after inducing LINC00460 knockdown. A xenograft tumour model was used to determine the effects of LINC00460 on tumour growth and metastasis in vivo. To examine the interaction between LINC00460 and ELAVL1, RNA pulldown and RNA immunoprecipitation assays were performed. LINC00460 was found to be significantly upregulated in CSCC tissues and cell lines. Functionally, LINC00460 knockdown inhibited cell proliferation, migration, and invasion in vitro. Consistent with this, when LINC00460 expression decreased, CSCC tumorigenesis and metastasis in vivo were inhibited. Mechanistically, LINC00460 binds to embryonic lethal abnormal vision like RNA binding protein 1 (ELAVL1) and enhances its stability by inhibiting the β-transducin repeats-containing protein (β-TrCP)-mediated ubiquitination of ELAVL1. Moreover, the effect of LINC00460 silencing on the proliferation, migration, and invasion of CSCC cells could be reversed by overexpressing ELAVL1. Our findings demonstrated that LINC00460 plays a critical role in regulating ELAVL1 function. This highlights the potential targets for the clinical diagnosis and treatment of CSCC.

A tEMTing target? Clinical and experimental evidence for epithelial-mesenchymal transition in the progression of cutaneous squamous cell carcinoma (a scoping systematic review)

Cutaneous squamous cell carcinoma (cSCC) is a disease with globally rising incidence and poor prognosis for patients with advanced or metastatic disease. Epithelial-mesenchymal transition (EMT) is a driver of metastasis in many carcinomas, and cSCC is no exception. We aimed to provide a systematic overview of the clinical and experimental evidence for EMT in cSCC, with critical appraisal of type and quality of the methodology used. We then used this information as rationale for potential drug targets against advanced and metastatic cSCC. All primary literature encompassing clinical and cell-based or xenograft experimental studies reporting on the role of EMT markers or related signalling pathways in the progression of cSCC were considered. A screen of 3443 search results yielded 86 eligible studies comprising 44 experimental studies, 22 clinical studies, and 20 studies integrating both. From the clinical studies a timeline illustrating the alteration of EMT markers and related signalling was evident based on clinical progression of the disease. The experimental studies reveal connections of EMT with a multitude of factors such as genetic disorders, cancer-associated fibroblasts, and matrix remodelling via matrix metalloproteinases and urokinase plasminogen activator. Additionally, EMT was found to be closely tied to environmental factors as well as to stemness in cSCC via NFκB and β-catenin. We conclude that the canonical EGFR, canonical TGF-βR, PI3K/AKT and NFκB signalling are the four signalling pillars that induce EMT in cSCC and could be valuable therapeutic targets. Despite the complexity, EMT markers and pathways are desirable biomarkers and drug targets for the treatment of advanced or metastatic cSCC.

Roles of the H19/microRNA‑675 axis in the proliferation and epithelial‑mesenchymal transition of human cutaneous squamous cell carcinoma cells

The long non-coding RNA (lncRNA) H19 and microRNA(miR)-675 were reported to serve an important role in the tumorigenesis and metastasis of numerous cancer types by promoting the epithelial-mesenchymal transition (EMT) process; however, the underlying mechanisms of action of H19 and miR-675 in cutaneous squamous cell carcinoma (cSCC) remain unknown. The mRNA expression levels of H19 and miR-675 were analyzed using reverse transcription-quantitative PCR, and Cell Counting Kit-8, wound healing and Transwell assays were performed to analyze the cell proliferation, migration and invasion of cSCC cells, respectively. The levels of cell apoptosis were also determined using a TUNEL assay. Protein expression levels of p53 and marker proteins related to the EMT process were analyzed using western blotting. In addition, a dual luciferase reporter assay was performed to determine the interactions between H19, miR-675 and p53. The results of the present study revealed that the expression levels of H19 and miR-675 were upregulated in cSCC tissues and cSCC cell lines. The knockdown of H19 or miR-675 expression inhibited cell proliferation, migration and invasion, but induced cell apoptosis. In addition, the expression levels of EMT-related markers were also downregulated. The overexpression of H19 upregulated the expression levels of its predicted target, miR-675, which subsequently promoted the EMT process and downregulated the expression levels of p53. Conversely, the genetic silencing of H19 or miR-675 inhibited proliferation and invasion in SCL1 and A431 cSCC cell lines. In conclusion, the findings of the present study provided novel insight into the potential role of H19 and miR-675 in the development, metastasis and progression of cSCC, which may help the development of treatments for cSCC.

Fibroblast growth factor 2 accelerates the epithelial-mesenchymal transition in keratinocytes during wound healing process

In the wound healing process, the morphology of keratinocytes at the wound edge temporarily changes to a spindle morphology, which is thought to occur due to an epithelial–mesenchymal transition (EMT). Fibroblast growth factor (FGF) 2, also called basic FGF, has the potential to accelerate wound closure by activating vascular endothelial cells and fibroblasts. We examined the effects of FGF2 on keratinocyte morphology and EMT in wounded skin. Histological examination of murine wounds treated with FGF2 revealed that wound edge keratinocytes formed thickened and multilayered epithelia. In addition, we detected wound edge keratinocytes migrating individually toward the wound center. These migrating keratinocytes exhibited not only spindle morphology but also down-regulated E-cadherin and up-regulated vimentin expression, which is characteristic of EMT. In FGF2-treated wounds, a PCR array revealed the upregulation of genes related to EMT, including transforming growth factor (TGF) signaling. Further, FGF2-treated wound edge keratinocytes expressed EMT-associated transcription factors, including Snai2, and showed translocation of β-catenin from the cell membrane to the cytoplasm/nucleus. However, in vitro examination of keratinocytes revealed that FGF2 alone did not activate EMT in keratinocytes, but that FGF2 might promote EMT in combination with TGFβ1. These findings suggest that FGF2 treatment of wounds could promote keratinocyte EMT, accelerating wound closure.