AG490 is a selective inhibitor of the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway. The present study examined its effects on the abnormal behavior of human keloid fibroblasts (HKFs) and evaluated its potential use in the treatment of keloids. Human normal fibroblasts (HNFs) and HKFs were treated with increasing concentrations of AG490. The proliferation of HNFs and HKFs was inhibited by AG490 in both a time-and concentration-dependent manner by increasing apoptosis and inducing G1 cell cycle arrest. The downregulation of cyclin d1 and connective tissue growth factor (cTGF) expression was associated with a decrease in STAT3 expression in response to AG490. The effects of AG490 on TGF-β-stimulated fibroblasts, including HNFs, HKFs and hypertrophic scar fibroblasts (HSFs) were also evaluated. The TGF-β1-stimulated excessive proliferation and cTGF production were markedly inhibited by the application of AG490 in the HNFs, HSFs and HKFs. In addition, the STAT3-specific decoy oligodeoxynucleotides (SOdNs) were transfected into HKFs. The invasive ability of the SOdN-transfected HKFs was determined and the expression of extracellular matrix components was quantified. Similarly, SODNs blocked the constitutive activation of STAT3. SOdNs inhibited the invasion and progression of HKFs, possibly via the upregulation of the expression of tissue inhibitor of metalloproteinase-2 (TIMP-2), and the downregulation of the expression of matrix metalloproteinase-2 (MMP-2) and vascular endothelial growth factor (VEGF). On the whole, the findings of the present study demonstrate that STAT3-specific elimination, such as the application of AG490 and decoy OdNs, may serve as promising therapeutic strategies for the treatment of keloids.

Raddeanin A (RA) has indicated suppressive effects on various human tumor cells, and insufficient vitamin D was associated with human papillomavirus (HPV) persistence and gynecological tumors. However, combined effects of RA and vitamin D on HPV-positive cells remain elusive. Herein, we aimed to investigate the combined effects of RA and 1ɑ,25(OH) 2 D 3 (VD3) on cellular viability and modulation of HPV18E6/E7, programmed cell death 1 ligand (PD-L1) and vitamin D receptor (VDR) expression in HeLa cells in vitro . HeLa cells were treated with RA alone or VD3 combined with RA. Cell viability was measured using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), and apoptosis was detected by flow cytometry. Real-time PCR (qRT-PCR) and Western blot were used to determine the gene/protein expression levels. The autophagosomes were observed by Transmission electron microscopy (TEM). The result showed that cell viability was inhibited by RA, and apoptosis in HeLa cells treated with RA was elevated accordingly. The expression of Bax, Cleaved-caspase-3, Cleaved-caspase-9 and Cleaved-PARP increased, and Bcl-2 decreased. The autophagy was induced by RA, as evidenced by elevated autophagosomes and the increased LC3-II/I ratio and Beclin-1. The expression of HPV18E6/E7, PD-L1 and VDR was reduced by RA. Moreover, RA combined with VD3 had a stronger effect on HeLa cells than RA alone. In conclusion, RA inhibits HeLa proliferation and induces apoptosis and autophagy via suppressing HPV18E6/E7, PD-L1 and VDR, and VD3 showed reinforced effects of RA on HeLa cells. Therefore, combined usage of VD3 with RA might be a potential novel immunotherapy strategy for HPV-related diseases.