No abstract

PurposeLong non-coding RNAs (lncRNAs) have been proved to act crucial parts in the progress of human tumor. However, the role of lncRNAs in drug resistance of tumor cells remains to be further elucidated. The present study aimed to explore whether lncRNA NCK-AS1 could affect the cisplatin (DDP) resistance in human osteosarcoma cell and the underlying molecular mechanism.MethodsThe expression of NCK1-AS1 and miR-137 in osteosarcoma cells was detected by qRT-PCR. CCK-8 assay, colony formation assay, Western blotting, wound healing assay and transwell assay were employed to assess the cell proliferation, migration and invasion. In addition, CCK-8 assay, flow cytometry, qRT-PCR and resistance gene activity analysis were performed to assess the DDP sensitivity of osteosarcoma cells. The interaction between NCK1-AS1 and miR-137 was identified using a dual-luciferase reporter gene assay and RNA immunoprecipitation (RIP) assay.ResultsThe results revealed that NCK1-AS1 was significantly upregulated in osteosarcoma cells, as well as in DDP-resistant osteosarcoma cells. NCK1-AS1 silence inhibited the proliferation, migration and invasion of osteosarcoma cells, whereas enhanced the sensitivity of osteosarcoma cells to DDP. Furthermore, NCK1-AS1 directly interacted with miR-137 and overexpression of miR-137 suppressed the proliferation, migration and invasion of osteosarcoma cells. Most importantly, miR-137 overexpression enhanced the sensitivity of osteosarcoma cells to DDP, and high expression of NCK1-AS1 reversed the influences of miR-137 overexpression on DDP-resistant cells.ConclusionIn short, NCK1-AS1 knockdown enhanced DDP sensitivity of osteosarcoma cells by regulating miR-137, which may be a novel potential target for anti-DDP resistance in human osteosarcoma.

Ferroptosis, an iron‐dependent cell death characterized by lethal lipid peroxidation, is involved in chronic obstructive pulmonary disease (COPD) pathogenesis. Therefore, ferroptosis inhibition represents an attractive strategy for COPD therapy. Herein, we identified natural flavonoid scutellarein as a potent ferroptosis inhibitor for the first time, and characterized its underlying mechanisms for inhibition of ferroptosis and COPD. In vitro, the anti‐ferroptotic activity of scutellarein was investigated through CCK8, real‐time quantitative polymerase chain reaction (RT‐qPCR), Western blotting, flow cytometry, and transmission electron microscope (TEM). In vivo, COPD was induced by lipopolysaccharide (LPS)/cigarette smoke (CS) and assessed by changes in histopathological, inflammatory, and ferroptotic markers. The mechanisms were investigated by RNA‐sequencing (RNA‐seq), electrospray ionization mass spectra (ESI‐MS), local surface plasmon resonance (LSPR), drug affinity responsive target stability (DARTS), cellular thermal shift assay (CETSA), and molecular dynamics. Our results showed that scutellarein significantly inhibited Ras‐selective lethal small molecule (RSL)‐3‐induced ferroptosis and mitochondria injury in BEAS‐2B cells, and ameliorated LPS/CS‐induced COPD in mice. Furthermore, scutellarein also repressed RSL‐3‐ or LPS/CS‐induced lipid peroxidation, GPX4 down‐regulation, and overactivation of Nrf2/HO‐1 and JNK/p38 pathways. Mechanistically, scutellarein inhibited RSL‐3‐ or LPS/CS‐induced Fe2+ elevation through directly chelating Fe2+. Moreover, scutellarein bound to the lipid peroxidizing enzyme arachidonate 15‐lipoxygenase (ALOX15), which resulted in an unstable state of the catalysis‐related Fe2+ chelating cluster. Additionally, ALOX15 overexpression partially abolished scutellarein‐mediated anti‐ferroptotic activity. Our findings revealed that scutellarein alleviated COPD by inhibiting ferroptosis via directly chelating Fe2+ and interacting with ALOX15, and also highlighted scutellarein as a candidate for the treatment of COPD and other ferroptosis‐related diseases.

Osteoarthritis (OA) is a common degenerative disease and affect millions of people. Resveratrol is a coumarin compound refined from traditional Chinese medicines with potential anti-inflammatory ability. This study aimed to evaluate protective anti-inflammatory effects of resveratrol in human OA chondrocytes. The chondrocytes were isolated from OA patients. CCK-8 method was used to explore the optimal dose of resveratrol for chondrocyte. Next, we used PCR and Western-blot method to assess the relative mRNA and protein expression in IL-1β group. We further explored relevant mechanism of resveratrol for anti-inflammatory in human OA chondrocytes by immunofluorescence and Western-blot. The results showed that resveratrol blocked IL-1β-stimulated production of NO and PGE2. In addition, resveratrol inhibited the expression of COX-2, iNOs, MMP-1, MMP-3, MMP-13, and increased the levels of aggrecan and collagen-II. Mechanistically, resveratrol suppressed IL-1βinduced IκB-α degradation and NF-κB activation. In conclusion, our results demonstrate that resveratrol inhibits inflammation in OA via the regulation of NF-κB signaling pathway, and suggested that resveratrol may be a potential therapeutic agent for OA. BackgroundOsteoarthritis (OA) acts as a prevalent chronic age-related disease joint disease featuring cartilage degradation, osteophyte formation, and joint stiffness, which seriously affects the health of the elderly people [1] . There is an increase in the incidence rate of OA with the aging of population, thus it is necessary to find an effective strategy for the treatment of OA [2] .During the progression of OA, the increased expression of interleukin-1β (IL-1β) in the articular cartilage and synovium leads to the destruction of cartilage, downregulation of type II collagen [3] .Furthermore, IL-1β has the function of inducing the chondrocyte release of prostaglandin E2 (PGE2) and nitric oxide (NO). Thus, reducing the IL-1β in articular cavity could delay the development of OA [4] .Resveratrol is a common polyphenolic compound in the skin of red grapes [5] . Resveratrol exhibits anti-ageing, anti-inflammatory, and anti-oxidant activities, and has cardio-, neuro-, and chondroprotective effects as proved by many studies [6] . Nuclear factor-kappa B (NF-κB) signaling XFS, YC and QRD conducted experiments; MQZ analyzed data; QRD and XFS wrote manuscript; YC revised manuscript; XFS and YC designed the experiment and edited manuscript.

The authors have withdrawn this preprint due to author disagreement.