Suppressor-type TERT mutations associated with recurrence in ovarian clear cell carcinoma.

Several cancers harbor "enhancer-type" mutations of the telomerase reverse transcriptase (TERT) promoter for immortalization. Here, we report that 8.6% (8/93) of ovarian clear cell carcinomas (OCCCs) possess the "suppressor-type" TERT promoter mutation. The recurrence rate of OCCCs with "suppressor-type" TERT promoter mutations was 62.5% (5/8) and was significantly higher than that of the "unaffected-type" with no mutation (20.8%, 15/72) or "enhancer-type" TERT promoter mutations (7.7%, 1/13). Our findings show that the acquired suppression of TERT is closely associated with OCCC development and recurrence, indicating the need for further research on telomerase suppression in cancers.

Paeonol alleviates interleukin-1ß-induced inflammatory responses in chondrocytes during osteoarthritis.

Interleukin-1ß (IL-1ß)-induced inflammatory responses in chondrocytes play an important role in the pathogenesis of osteoarthritis (OA). Searching medicines that affect IL-1ß-mediated chondrocytes function is critical in developing therapies for OA. Paeonol, as an important component in traditional Chinese medicine, has anti-inflammatory activity and can offer therapy for a multitude of inflammatory-related diseases. The purpose of this study was to investigate whether paeonol could alleviate the progression of OA through inhibition of IL-1ß-induced inflammatory responses in chondrocytes. The cell counting kit-8 assay, 5-ethynil-2'-deoxyuridine staining, hoechst 33258 staining and flow cytometric staining were used to observe the chondrocytes proliferation and apoptosis. Western blot and quantitative real-time PCR were applied to examine the expression of extracellular matrix and cartilage degrading enzymes. Reactive oxygen species (ROS) production was monitored by 2',7'-dichlorodihydrofluoresce in diacetate staining. Furthermore, paeonol was intra-articularly injected into joint capsule in destabilized medial meniscus (DMM)-induced OA rat model for 8 and 12 weeks. The results showed that paeonol could negatively affect IL-1ß-mediate chondrocyte apoptosis and proliferation. Application of paeonol attenuated the secretion of cartilage extracellular matrix and cartilage degrading enzymes induced by IL-1ß in chondrocytes. Increasing of ROS production by IL-1ß was obviously alleviated by paeonol. Besides, paeonol alleviated DMM-induced articular cartilage degeneration in vivo. Taken together, we concluded that paeonol might be used as therapeutic agent for treating OA.

Involvement of receptor-interacting protein 140 in estrogen-mediated osteoclasts differentiation, apoptosis, and bone resorption.

Estrogen withdrawal following menopause results in an increase of osteoclasts formation and bone resorption, which is one of the most important mechanisms of postmenopausal osteoporosis. Recently, growing evidence has suggested that receptor-interacting protein 140 was implicated in estrogen-regulated metabolic disease, including fat metabolism and lipid metabolism. However, little is known regarding the role of receptor-interacting protein 140 in the regulation of bone metabolic by estrogen. In the present study, Western blotting disclosed that estrogen brings a significant increasing expression of receptor-interacting protein 140 in osteoclasts, but not in osteoblasts and bone marrow mesenchymal stem cells. Furthermore, analysis of TRAP staining and bone resorption assay showed that depletion of receptor-interacting protein 140 could significantly alleviate the inhibitory effects of estrogen on osteoclasts formation and bone resorption activity. Moreover, estrogen could induce osteoclasts apoptosis by increasing receptor-interacting protein 140 expression through the Fas/FasL pathway. Taken together, receptor-interacting protein 140 might be a critical player in estrogen-mediated osteoclastogenesis and bone resorption.

Role of platelet-derived growth factor-BB (PDGF-BB) in human pulmonary artery smooth muscle cell proliferation.

Pulmonary arterial hypertension (PAH) is a vascular remodeling disease characterized by enhanced proliferation of pulmonary artery smooth muscle cells (PASMCs) and suppressed apoptosis. Platelet-derived growth factor (PDGF) is a potent mitogen involved in cell proliferation and migration. PDGF-BB induces the proliferation and migration of PASMCs and has been proposed to be a key mediator in the progression of PAH. Previous studies have shown that PDGF and its receptor are substantially elevated in lung tissues and PASMCs isolated from patients and animals with PAH, but the underlying mechanisms are still poorly manifested. MAP kinases, including extracellular signal-regulated kinase1/2 (ERK1/2), c-Jun NH2-terminal kinase1/2 (JNK1/2), and p38 are the key intracellular signals for stimuli-induced cell proliferation, survival, and apoptosis. Therefore, the purpose of this study is to determine whether PDGF-BB on cell proliferation process is mediated through the MAP kinases pathway in human PASMCs (HPASMCs). Our results showed PDGF-BB-induced proliferating cell nuclear antigen (PCNA), Cyclin A and Cyclin E expression in a concentration-dependent manner. The expression levels of phosphorylated JNK (p-JNK) was upregulated with 20 ng/ml PDGF-BB treatment, while PDGF-BB could not increase phosphorylated ERK1/2 (p-ERK1/2) and p-38 (p-p38) expression. The effects of PDGF-BB on cell proliferation and survival were weakened after the administration of antagonist of the JNK pathway or si-JNK. In addition, PDGF-BB protected against the loss of mitochondrial membrane potentials evoked by serum deprivation (SD) in a JNK-dependent manner. These results suggest that PDGF-BB promotes HPASMCs proliferation and survival, which is likely to be mediated via the JNK pathway.