miRNA-221 promotes cutaneous squamous cell carcinoma progression by targeting PTEN.

BACKGROUND: Cutaneous squamous cell carcinoma (CSCC) is a common type of skin malignancy. MicroRNA-221 (miRNA-221) is a critical non-coding RNA in tumor initiation and progression. However, the molecular mechanisms of miRNA-221 in the development of CSCC remain unknown. This study investigated the expression of miRNA-221 in CSCC and its potential tumor biological functions. METHODS: MTT assay, colony assay, PCR, and Western blot were adopted. RESULTS: In this study, miRNA-221 expression was significantly higher in CSCC tissues and cell lines than in normal tissues and cells (P < 0.05). Further functional experiments indicated that miRNA-221 knockdown inhibited the proliferation and cell cycle, while upregulation of miRNA-221 presented the opposite role. The dual reporter gene assays indicated that PTEN is a direct target gene of miRNA-221. PTEN protein or mRNA levels were decreased after the cells were transfected with miR-221 mimics. CONCLUSIONS: Taken together, the obtained results indicated that miR-221 plays an oncogenic function in CSCC by targeting PTEN and further suggest that miR-221 may be a potential target for CSCC diagnosis and treatment.

Ubenimex induces autophagy inhibition and EMT suppression to overcome cisplatin resistance in GC cells by perturbing the CD13/EMP3/PI3K/AKT/NF-κB axis.

Cisplatin (CDDP)-based chemotherapy is a standard treatment for gastric cancer (GC). However, chemoresistance is a major obstacle for CDDP application. Exploring underlying mechanisms of CDDP resistance development in GC and selecting an effective strategy to overcome CDDP resistance remain a challenge. Here, we demonstrate that a transmembrane ectoenzyme, CD13, endows GC patients with insensitivity to CDDP and predicts an undesirable prognosis in GC patients with CDDP treatment. Similarly, CD13 expression is positively related with CDDP resistance in GC cells. A CD13 inhibitor, Ubenimex, reverses CDDP resistance and renders GC cells sensitivity to CDDP, for which CD13 reduction is essential, and epithelial membrane protein 3 (EMP3) is a putative target downstream of CD13. Furthermore, Ubenimex decreases EMP3 expression by boosting its CpG island hypermethylation for which CD13 down-regulation is required. In addition, EMP3 is a presumptive modifier by which CD13 exerts functions in the phosphoinositol 3-kinase/protein kinase B (PI3K/AKT) pathway. Ubenimex inhibits the activation of the CD13/EMP3/PI3K/AKT/NF-κB pathway to overcome CDDP resistance in GC cells by suppressing autophagy and epithelial-mesenchymal transition (EMT). Therefore, CD13 is a potential indicator of CDDP resistance formation, and Ubenimex may serve as a potent candidate for reversing CDDP resistance in GC.

Association of plasminogen activator inhibitor-1 and vitamin D receptor expression with the risk of keloid disease in a Chinese population.

Keloid disease (KD) is a benign fibroproliferative scarring condition of unknown etiopathogenesis. Plasminogen activator inhibitor-1 (PAI-1) and vitamin D receptor (VDR) have been shown to play important roles in the progression of tissue fibrosis; therefore, both these genes are potential susceptibility genes for KD. We aimed to determine whether the gene expression levels of PAI-1 and VDR are altered in Chinese KD patients. We measured the expression of PAI and VDR in human peripheral blood lymphocytes in 236 patients with keloid and 219 age- and sex-matched healthy controls by quantitative real-time polymerase chain reaction. We found that PAI-1 expression in peripheral blood lymphocytes was significantly higher in patients with KD than in control individuals (p < 0.0001), while VDR expression was significantly lower in KD patients than in control individuals (p < 0.0001). High levels of PAI-1 and low levels of VDR expression were significantly associated with an increased risk for KD. PAI-1 and VDR might play important roles in keloid development. Gene expression levels of PAI-1 and VDR may, therefore, be used as potential markers for the prediction of keloid development after scarring.