Hypobaric hypoxia aggravates osteoarthritis via the alteration of the oxygen environment and bone remodeling in the subchondral zone.

A high prevalence of osteoarthritis (OA) has been observed among individuals living at high altitudes, and hypobaric hypoxia (HH) can cause bone mass and strength deterioration. However, the effect of HH on OA remains unclear. In this study, we aimed to explore the impact of HH on OA and its potential mechanisms. A rat knee OA model was established by surgery, and the rats were bred in an HH chamber simulating a high-altitude environment. Micro-computed tomography (Micro-CT), histological analysis, and RNA sequencing were performed to evaluate the effects of HH on OA in vivo. A hypoxic co-culture model of osteoclasts and osteoblasts was also established to determine their effects on chondrogenesis in vitro. Cartilage degeneration significantly worsened in the HH-OA group compared to that in the normoxia-OA (N-OA) group, 4 weeks after surgery. Micro-CT analysis revealed more deteriorated bone mass in the HH-OA group than in the N-OA group. Decreased hypoxia levels in the cartilage and enhanced hypoxia levels in the subchondral bone were observed in the HH-OA group. Furthermore, chondrocytes cultured in a conditioned medium from the hypoxic co-culture model showed decreased anabolism and extracellular matrix compared to those in the normoxic model. RNA sequencing analysis of the subchondral bone indicated that the glycolytic signaling pathway was highly activated in the HH-OA group. HH-related OA progression was associated with alterations in the oxygen environment and bone remodeling in the subchondral zone, which provided new insights into the pathogenesis of OA.

Prevalence and risk factors of osteoporotic fracture among the elderly population in China: a multicenter cross-sectional study.

PURPOSE: Prevalence of osteoporotic fracture (OPF) is increasing with ageing, resulting in a significant financial burden for healthcare. However, research on the nationwide epidemiological data of OPF in Chinese elderly is still scarce. The aim of this study was to investigate the prevalence and risk factors of OPF in Chinese population aged 60 years or order. METHODS: A cross-sectional survey was conducted in an elderly Chinese population in five centres. Questionnaire investigation and imaging examination were taken in all participants to identify OPF prevalence and risk factors. Diagnosis of OPF was determined based on imaging of vertebral fractures or history of fall-related fractures. We then used multivariate logistic regression model to analyze the associations between the potential risk factors and OPF. RESULTS: The overall prevalence of OPF in population aged 60 years or older was 24.7% (1,071/4,331), showing an increasing trend with age (P < 0.001). The prevalence of OPF was geographically distinct (P < 0.001), but similar between men and women (P > 0.05). Up to 96.8% of OPFs consisted of vertebral fractures, especially involving T11, T12, and L1 segments. Advanced age (≥ 80), vision loss, severe hearing loss, multiple exercise forms, chronic kidney disease, osteoarthritis, and trauma-related vertebral fractures were significantly associated with risk factors, while education level and vitamin D supplementation were associated with protective factors of OPF. CONCLUSION: High prevalence of OPF is a serious threat to bone health among elderly people in China. There is an urgent need for effective strategies to diagnose, prevent, and treat OPF in elderly adults.

Does Moses technology enhance the efficiency and outcomes of regular holmium laser lithotripsy? Results of a pooled analysis of comparative studies.

Holmium laser lithotripsy is currently the optimum standard for surgical treatment of upper urinary calculi. This study aims to evaluate the clinical efficacy and safety of Moses compared with conventional holmium laser lithotripsy for the treatment of patients with upper urinary calculi. We conducted a systematic search using multiple databases (PubMed/Medline, Scopus, Web of Science, and ClinicalTrials.gov) until June 2022. Clinical trials comparing Moses and conventional holmium laser lithotripsy were included. Analysis was performed using RevMan version 5.4.4 software. Four studies with 892 patients were included. There were no significant differences regarding stone-free rate (mean difference [MD] 1.19, 95% CI 0.54, 2.64, p = 0.66), operative time (MD - 9.31, 95% CI - 21.11, 2.48, p = 0.12), fragmentation time (MD - 1.71, 95% CI - 11.81, 8.38, p = 0.74), total energy used (MD 1.23, 95% CI - 0.44, 2.90, p = 0.15), auxiliary procedures (MD 0.38, 95% CI 0.08, 1.90, p = 0.24), and overall complications (odds ratio [OR] 0.70, 95% CI 0.30, 1.66, p = 0.42) between the groups. However, the laser working time (MD - 0.94, 95% CI - 1.20, - 0.67, p < 0.001) of Moses technology was shorter than that of conventional technology. Moses technology has similar outcomes to regular technology in terms of safety and efficacy. Given the higher operating costs of the Moses technology, further study is required to determine whether there are benefits to this new technology.

SIGIRR deficiency contributes to CD4 T cell abnormalities by facilitating the IL1/C/EBPß/TNF-α signaling axis in rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is a complex autoimmune disease with multiple etiological factors, among which aberrant memory CD4 T cells activation plays a key role in the initiation and perpetuation of the disease. SIGIRR (single immunoglobulin IL-1R-related receptor), a member of the IL-1 receptor (ILR) family, acts as a negative regulator of ILR and Toll-like receptor (TLR) downstream signaling pathways and inflammation. The aim of this study was to investigate the potential roles of SIGIRR on memory CD4 T cells in RA and the underlying cellular and molecular mechanisms. METHODS: Single-cell transcriptomics and bulk RNA sequencing data were integrated to predict SIGIRR gene distribution on different immune cell types of human PBMCs. Flow cytometry was employed to determine the differential expression of SIGIRR on memory CD4 T cells between the healthy and RA cohorts. A Spearman correlation study was used to determine the relationship between the percentage of SIGIRR+ memory CD4 T cells and RA disease activity. An AIA mouse model (antigen-induced arthritis) and CD4 T cells transfer experiments were performed to investigate the effect of SIGIRR deficiency on the development of arthritis in vivo. Overexpression of SIGIRR in memory CD4 T cells derived from human PBMCs or mouse spleens was utilized to confirm the roles of SIGIRR in the intracellular cytokine production of memory CD4 T cells. Immunoblots and RNA interference were employed to understand the molecular mechanism by which SIGIRR regulates TNF-α production in CD4 T cells. RESULTS: SIGIRR was preferentially distributed by human memory CD4 T cells, as revealed by single-cell RNA sequencing. SIGIRR expression was substantially reduced in RA patient-derived memory CD4 T cells, which was inversely associated with RA disease activity and related to enhanced TNF-α production. SIGIRR-deficient mice were more susceptible to antigen-induced arthritis (AIA), which was attributed to unleashed TNF-α production in memory CD4 T cells, confirmed by decreased TNF-α production resulting from ectopic expression of SIGIRR. Mechanistically, SIGIRR regulates the IL-1/C/EBPß/TNF-α signaling axis, as established by experimental evidence and cis-acting factor bioinformatics analysis. CONCLUSION: Taken together, SIGIRR deficiency in memory CD4 T cells in RA raises the possibility that receptor induction can target key abnormalities in T cells and represents a potentially novel strategy for immunomodulatory therapy.

Evaluation of Medical Information on Male Sexual Dysfunction on Baidu Encyclopedia and Wikipedia: Comparative Study.

BACKGROUND: Sexual dysfunction is a private set of disorders that may cause stigma for patients when discussing their private problems with doctors. They might also feel reluctant to initiate a face-to-face consultation. Internet searches are gradually becoming the first choice for people with sexual dysfunction to obtain health information. Globally, Wikipedia is the most popular and consulted validated encyclopedia website in the English-speaking world. Baidu Encyclopedia is becoming the dominant source in Chinese-speaking regions; however, the objectivity and readability of the content are yet to be evaluated. OBJECTIVE: Hence, we aimed to evaluate the reliability, readability, and objectivity of male sexual dysfunction content on Wikipedia and Baidu Encyclopedia. METHODS: The Chinese Baidu Encyclopedia and English Wikipedia were investigated. All possible synonymous and derivative keywords for the most common male sexual dysfunction, erectile dysfunction, premature ejaculation, and their most common complication, chronic prostatitis/chronic pelvic pain syndrome, were screened. Two doctors evaluated the articles on Chinese Baidu Encyclopedia and English Wikipedia. The Journal of the American Medical Association (JAMA) scoring system, DISCERN instrument, and Global Quality Score (GQS) were used to assess the quality of disease-related articles. RESULTS: The total DISCERN scores (P=.002) and JAMA scores (P=.001) for Wikipedia were significantly higher than those of Baidu Encyclopedia; there was no statistical difference between the GQS scores (P=.31) for these websites. Specifically, the DISCERN Section 1 score (P<.001) for Wikipedia was significantly higher than that of Baidu Encyclopedia, while the differences between the DISCERN Section 2 and 3 scores (P=.14 and P=.17, respectively) were minor. Furthermore, Wikipedia had a higher proportion of high total DISCERN scores (P<.001) and DISCERN Section 1 scores (P<.001) than Baidu Encyclopedia. Baidu Encyclopedia and Wikipedia both had low DISCERN Section 2 and 3 scores (P=.49 and P=.99, respectively), and most of these scores were low quality. CONCLUSIONS: Wikipedia provides more reliable, higher quality, and more objective information than Baidu Encyclopedia. Yet, there are opportunities for both platforms to vastly improve their content quality. Moreover, both sites had similar poor quality content on treatment options. Joint efforts of physicians, physician associations, medical institutions, and internet platforms are needed to provide reliable, readable, and objective knowledge about diseases.

Reduction in Peyronie's-like plaque size using a vacuum erection device in a rat model of Peyronie's disease via the TGF-ß/SMAD signalling pathway.

Peyronie's disease (PD) is a fibrotic disorder of the tunica albuginea (TA). This study aimed to determine the therapeutic effects of a vacuum erection device (VED) in an animal model of PD and explore the possible mechanisms. Twenty-seven male Sprague-Dawley rats were used. The sham group (group A) (N = 9) received a 50-µl-saline vehicle injection into the TA, while the remaining 18 rats (groups B and C) received a TGF-ß1 injection into the TA. The treatment group (group C) underwent VED therapy for 10 days after the TGF-ß1 injection. Erectile function was then assessed at day 42. Rats injected with TGF-ß1 showed significantly lower intracavernous pressures than those in the sham group (p < 0.0001). After VED therapy, erectile function was significantly better in the treatment group than in the PD group (group B) (p < 0.0147). Masson's trichrome staining confirmed Peyronie's-like plaques at the TGF-ß1 injection site in the PD group. Furthermore, the treatment group showed markedly smaller fibrotic plaque sizes than the PD group. A significant increase in TGF-ß1, SMAD2, SMAD3 and p-SMAD2/3 protein expression was observed 6 weeks after the TGF-ß1 injection. However, the expression of the same proteins decreased after VED therapy. Protein expression trends were confirmed using immunohistochemistry analysis. The findings of this study demonstrate that VED therapy can reduce Peyronie's-like plaque size in a rat model of PD while simultaneously improving erectile function.

Association of fat distribution differences in infertile women with assisted reproductive outcomes: A prospective cohort study.

OBJECTIVE: To investigate the impacts of fat distribution on assisted reproductive outcomes in infertile women. METHODS: The study randomly recruited 576 infertile women who underwent assisted reproductive technology treatment at the Reproductive Medicine Center of the First Affiliated Hospital of Anhui Medical University between July and October 2022. Questionnaires and body composition measurements were administered to assess baseline information and fat distribution. The numbers of oocytes, zygotes presenting with two pronuclei (2PN), and available embryos were tracked at the end of the cycle. Multifactorial logistic regression models and restricted cubic spline (RCS) curve models were used to explore the relationships between fat distribution and reproductive outcomes while controlling for confounding factors. RESULTS: The study found that the participants had a mean age of 30.82 years. The analysis showed that there was a significant difference between the amount of leg body fat mass (LBFM) and the distribution of reproductive outcomes. However, there was no significant correlation between the level of visceral fat and reproductive outcomes. After taking confounding factors into account, the multifactorial regression analysis showed that the total body fat mass and the number of oocytes (odds ratio (OR) 0.92, 95% confidence interval (CI) 0.84-0.99), 2PN (OR 0.92, 95% CI 0.84-0.99), and embryos available for transfer (OR 0.90, 95% CI 0.82-0.99) were negatively correlated. RCS modeling revealed a linear dose-response relationship between LBFM and assisted reproductive outcomes. CONCLUSION: Fat distribution varies among infertile women, and higher amounts of fat are associated with poorer assisted reproductive outcomes.

Human umbilical cord mesenchymal stem cells derived extracellular vesicles ameliorate kidney ischemia-reperfusion injury by suppression of senescent tubular epithelial cells - Experimental Study.

BACKGROUND: Human umbilical cord mesenchymal stem cells derived extracellular vesicles (HUMSC-EVs) have drawn much interest in kidney transplantation, mainly because of their renoprotection by alleviating cell injury and stimulating tissue repair. Cellular senescence has been proven to play a dual regulatory role in kidney ischemia-reperfusion injury (IRI), and the regulation of HUMSC-EVs on tubular epithelial cell senescence may be a potential therapeutic target. MATERIALS AND METHODS: In vitro, the hypoxia-reoxygenation of human kidney-2 cells was used to simulate kidney IRI, and the regulation of HUMSC-EVs on human kidney-2 cells was detected. Transcriptome sequencing of human kidney-2 cells was used to explore the potential regulatory mechanism. In vivo, adult male mice were divided into five groups: control group, IRI group, HUMSC-EVs treatment group, senolytics treatment group (dasatinib + quercetin), and combined treatments group (HUMSC-EVs and senolytics). Kidney function, senescent features of tubular epithelial cells, acute kidney injury, and chronic interstitial fibrosis in mice were detected to explore the renoprotection effects of HUMSC-EVs. RESULTS: Kidney IRI significantly up-regulated expressions of LaminB1, p53, p21, p16, senescence-associated beta-galactosidase, and apoptosis of tubular epithelial cells. In the mouse kidney IRI model, kidney subcapsular injection of HUMSC-EVs significantly improved kidney function, reducing the senescent features of tubular epithelial cells and alleviating acute kidney injury and chronic interstitial fibrosis. HUMSC-EVs mainly achieved renoprotection by regulating Bax/Bcl-2-dependent apoptosis during acute kidney injury and mostly reduced tubular atrophy and kidney interstitial fibrosis by regulating Ras-pERK-Ets1-p53 pathway-dependent cell senescence. Oral administration of senolytics also alleviated kidney injury induced by IRI, while the combined treatments of HUMSC-EVs and senolytics had better renoprotection effects. CONCLUSIONS: The combination of HUMSC-EVs and senolytics alleviated acute kidney injury and chronic interstitial fibrosis by dynamic regulation of cell senescence and apoptosis, which provides a therapeutic potential strategy for organ preservation and tissue repair in kidney transplantation.

Potential molecular biomarkers for the diagnosis and prognosis of bladder cancer.

Bladder cancer (BC) is a common malignant tumor of urinary system, which can be divided into muscle-invasive BC (MIBC) and nonmuscle-invasive BC (NMIBC). The number of BC patients has been gradually increasing currently. At present, bladder tumours are diagnosed and followed-up using a combination of cystoscopic examination, cytology and histology. However, the detection of early grade tumors, which is much easier to treat effectively than advanced stage disease, is still insufficient. It frequently recurs and can progress when not expeditiously diagnosed and monitored following initial therapy for NMIBC. Treatment strategies are totally different for different stage diseases. Therefore, it is of great practical significance to study new biomarkers for diagnosis and prognosis. In this review, we summarize the current state of biomarker development in BC diagnosis and prognosis prediction. We retrospectively analyse eight diagnostic biomarkers and eight prognostic biomarkers, in which CK, P53, PPARγ, PTEN and ncRNA are emphasized for discussion. Eight molecular subtype systems are also identified. Clinical translation of biomarkers for diagnosis, prognosis, monitoring and treatment will hopefully improve outcomes for patients. These potential biomarkers provide an opportunity to diagnose tumors earlier and with greater accuracy, and help identify those patients most at risk of disease recurrence.

Ex Vivo Surgical Removal Versus Conservative Management of Small Asymptomatic Kidney Stones in Living Donors and Long-term Kidney Transplant Outcomes.

BACKGROUND: Donors with small asymptomatic kidney stones have been increasingly accepted because of organ shortages and advances in endoscopic urology. This study aims to evaluate and compare long-term living-donor kidney transplant outcomes following ex vivo surgical removal versus conservative management of donors' gifted asymptomatic stones. METHODS: Between January 2007 and December 2021, 119 kidney transplant recipients received stone-bearing kidneys, divided into the removal group (N = 63) and observation group (N = 56). We evaluated posttransplant stone events, urinary infections, kidney function, delayed graft function, length of hospital stay, and survival outcomes. RESULTS: After a median follow-up of 75.5 mo, the removal group had a 10.9% lower absolute incidence of stone events (7/56 [12.5%] versus 1/63 [1.6%]; hazard ratio, 0.08; 95% confidence interval, 0.01-0.77) and a 14.3% lower absolute incidence of urinary infections (16/56 [28.6%] versus 9/63 [14.3%]; hazard ratio, 0.42; 95% confidence interval, 0.19-0.95) than the observation group. The removal group also showed superior kidney graft function. The 2 groups had comparable length of hospital stay (11.0 versus 12.0 d; P = 0.297) and exhibited similar delayed graft function incidence (1/56 [1.8%] versus 2/63 [3.2%]; P = 1.000) and urinary stricture incidence (1/56 [1.8%] versus 3/63 [4.8%]; P = 0.621). Graft survival (P = 0.350) and patient survival (P = 0.260) were comparable between 2 groups. Subgroup analyses in recipients who received kidneys with stones <4 mm also reported similar results. CONCLUSIONS: Ex vivo surgical removal might outperform conservative management for donors' gifted asymptomatic kidney stones, improving long-term transplant outcomes and reducing stone events without increasing perioperative complications, even for stones <4 mm.

Dendritic Polymer-Based Nanomedicines Remodel the Tumor Stroma: Improve Drug Penetration and Enhance Antitumor Immune Response.

The dense extracellular matrix (ECM) in solid tumors, contributed by cancer-associated fibroblasts (CAFs), hinders penetration of drugs and diminishes their therapeutic outcomes. A sequential treatment strategy of remodeling the ECM via a CAF modifier (dasatinib, DAS) is proposed to promote penetration of an immunogenic cell death (ICD) inducer (epirubicin, Epi) via apoptotic vesicles, ultimately enhancing the treatment efficacy against breast cancer. Dendritic poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA)-based nanomedicines (poly[OEGMA-Dendron(G2)-Gly-Phe-Leu-Gly-DAS] (P-DAS) and poly[OEGMA-Dendron(G2)-hydrazone-Epi] (P-Epi)) are developed for sequential delivery of DAS and Epi, respectively. P-DAS reprograms CAFs to reduce collagen by downregulating collagen anabolism and energy metabolism, thereby reducing the ECM deposition. The regulated ECM can enhance tumor penetration of P-Epi to strengthen its ICD effect, leading to an amplified antitumor immune response. In breast cancer-bearing mice, this approach alleviates the ECM barrier, resulting in reduced tumor burden and increased cytotoxic T lymphocyte infiltration, and more encouragingly, synergizes effectively with anti-programmed cell death 1 (PD-1) therapy, significantly inhibiting tumor growth and preventing lung metastasis. Furthermore, systemic toxicity is barely detectable after sequential treatment with P-DAS and P-Epi. This approach opens a new avenue for treating desmoplastic tumors by metabolically targeting CAFs to overcome the ECM barrier.

Efficacy and Safety of Biosimilar QL1207 vs. the Reference Aflibercept for Patients with Neovascular Age-Related Macular Degeneration: A Randomized Phase 3 Trial.

INTRODUCTION: This trial aimed to compare the efficacy and safety between biosimilar QL1207 and the reference aflibercept for the treatment of neovascular age-related macular degeneration (nAMD). METHODS: This randomized, double-blind, phase 3 trial was conducted at 35 centers in China. Patients aged ≥ 50 years old with untreated subfoveal choroidal neovascularization secondary to nAMD and best-corrected visual acuity (BCVA) letter score of 73-34 were eligible. Patients were randomly assigned to receive intravitreous injections of QL1207 or aflibercept 2 mg (0.05 ml) in the study eye every 4 weeks for the first 3 months, followed by 2 mg every 8 weeks until week 48, stratified by baseline BCVA ≥ or < 45 letters. The primary endpoint was BCVA change from baseline at week 12. The equivalence margin was ± 5 letters. The safety, immunogenicity, pharmacokinetics (PK), and plasma vascular endothelial growth factor (VEGF) concentration were also evaluated. RESULTS: A total of 366 patients were enrolled (QL1207 group, n = 185; aflibercept group, n = 181) from Aug 2019 to Jan 2022 with comparable baseline characteristics. The least-squares mean difference in BCVA changes was - 1.1 letters (95% confidence interval - 3.0 to 0.7; P = 0.2275) between the two groups, within the equivalence margin. The incidences of treatment-emergent adverse events (TEAE; QL1207: 71.4% [132/185] vs. aflibercept: 71.8% [130/181]) and serious TEAE (QL1207: 14.1% [26] vs. aflibercept: 12.7% [23]) appeared comparable between treatment groups, and no new safety signal was found. Anti-drug antibody, PK profiles, and VEGF concentration were similar between the two groups. CONCLUSIONS: QL1207 has equivalent efficacy to aflibercept for nAMD with similar safety profiles. It could be used as an alternative anti-VEGF agent for clinical practice. TRIAL REGISTRATION: ClinicalTrials.gov: NCT05345236 (retrospectively registered on April 25, 2022); National Medical Products Administration of China: CTR20190937 (May 20, 2019).

A Novel Insight into the Immune-Related Interaction of Inflammatory Cytokines in Benign Prostatic Hyperplasia.

Benign prostatic hyperplasia (BPH) is a common male condition that impacts many men's quality of life by generating lower urinary tract symptoms (LUTS). In recent years, inflammation has become very common in the prostate, and BPH with inflammation has a higher International Prostate Symptom Score (IPSS) score and an enlarged prostate. Chronic inflammation leads to tissue damage and the release of pro-inflammatory cytokines, which play an important role in the pathogenesis of BPH. We will focus on current advancements in pro-inflammatory cytokines in BPH, as well as the future of pro-inflammatory cytokine research.

A sulfhydryl blocking reagent BT-4 sensitizes cisplatin-based micelle prodrugs for efficient treatment of breast cancer.

Detoxification of glutathione (GSH) and insufficient cellular uptake of cisplatin (CDDP) severely compromised the therapeutic efficacy of CDDP. Here, a nano-delivery system (BT-4@PtPPNPs) for CDDP prodrug (C16-Pt(Ⅳ)-PEG) based on a novel sulfhydryl blocking reagent methyl 2-(methylsulfonyl) benzothiazole-6-carboxylate (BT-4) was developed. On the one hand, BT-4 can deplete GSH in tumor cells by directly interacting with reactive sulfhydryl group on GSH, thereby increasing the cytotoxicity of CDDP. On the other hand, the CDDP prodrug carrier C16-Pt(IV)-PEG can promote the distribution of CDDP in tumors, reduce the probability of unexpected inactivation of CDDP, and reduce the content of GSH in tumor cells during the conversion to CDDP, thereby making CDDP more effective for treatment. The results showed that the optimized BT-4@PtPPNPs with a small particle size (130 nm) exhibited notable cytotoxicity and apoptosis of 4T1 cells. BT-4@PtPPNPs not only significantly improved the uptake of drugs by tumor cells, but also rapidly targeted and accumulated in the tumors for a long time. Moreover, in vivo efficacy studies showed that BT-4@PtPPNPs could effectively inhibit tumor growth, inhibiting 60.85 % of tumors in a 4T1 breast cancer mice model, showing superior antitumor activity, which can be attributed to GSH-triggered CDDP tolerance reversal. Overall, this study provides an attractive and simple strategy to combine novel sulfhydryl blockers and CDDP prodrugs to potentiate the efficacy of CDDP in breast cancer.

Targeting FGFRs for tumor therapy: current status and novel strategies.

The FGF receptors (FGFRs) belong to a family of receptor tyrosine kinases. Abundant evidence shows that FGFRs are closely related to tumor cell invasion and angiogenesis. Hence, targeted modulation of FGFRs has become an effective strategy for cancer treatment. Recently, the development of small-molecule inhibitors targeting FGFRs has been extensively studied, and three inhibitors have been approved for marketing. Based on the clinical problems with the current inhibitors, there is a need to develop novel inhibitors and technologies to address the pitfalls. This review summarizes recent advances in small-molecule inhibitors targeting FGFRs, focusing on structure-activity relationships. Moreover, recent progress of novel technologies are summarized to provide a reference for promoting the application of drugs targeting FGFRs in tumor therapy.

NEK2 promotes proliferation, migration and tumor growth of gastric cancer cells via regulating KDM5B/H3K4me3.

The mechanisms of how Never in Mitosis (NIMA) Related Kinase 2 (NEK2) coordinates altered signaling to malignant gastric cancer (GC) transformation remain unclear. Overexpression of NEK2 and KDM5B were observed in GC cell lines with high sensitivity to NEK2 inhibitors. Here we investigated the biological behaviors of NEK2 and the possible mechanisms of regulative effects of NEK2 on KDM5B in GC cell lines both in vitro and in vivo. The results showed that NEK2 and KDM5B were highly expressed in most of the 10 GC cell lines. NEK2 knockdown in MGC-803 cells led to suppression of cell proliferation and migration in vitro and tumor growth in vivo, while NEK2 overexpression in BGC-823 cells exhibited the reverse biological effect. When NEK2 was inhibited by NEK2 inhibitors or shNEK2, cellular KDM5B level decreased and H3K4me3 level increased, while overexpression of NEK2 resulted in enhanced KDM5B expression and decreased H3K4me3 level. Though direct interaction between NEK2 and KDM5B was excluded, NEK2 could regulate KDM5B/H3K4me3 expression through ß-catenin/Myc both in vitro and in vivo, which was double confirmed by c-myc and KDM5B inhibitor experiments. Taken together, our study showed that NEK2 was highly expressed in GC cell lines and related to promoting cell proliferation, migration and tumor growth. A NEK2/ß-catenin/Myc/KDM5B/H3K4me3 signaling pathway may contribute to the important carcinogenic role of NEK2-mediated malignant behaviors in GC.

Characterization of a near-infrared fluorescent DCPO-tagged glucose analogue for cancer cell imaging.

Cancer cells are usually characterized with an increase in glucose uptake when compared with normal cells, which is known as Warburg effect. Near-infrared (NIR) fluorescent glucose analogues have been previously synthesized and been applied in cancer cell imaging. However, most NIR dyes usually have one or more charge in their structures, which may cause low cell membrane permeability and hamper their application in cell imaging. Here we reported a novel glucose analogue N2, which was designed and synthesized based on a new type of NIR dye, DCPO. As expected, higher level of N2 uptake was observed in hepatic carcinoma cells (HepG2) and gastric cancer cells (NCI-N87) than their equivalent cells from normal tissues of the same origin, respectively. The accumulation of N2 in cancer cells was in consistent with the overexpression of glucose transporter GLUT-1 in these cells. The cellular uptake of N2 was then confirmed to be dependent on GLUT-1, which was evidenced by the decreased uptake of N2 in the presence of d-glucose or GLUT-1 inhibitor phloretin. Moreover, uptake of N2 in cancer cells was found to be in a concentration- and time-dependent manner. In all, our study demonstrated that N2, as a novel DCPO-conjugated bioprobe, could be used to monitor cellular glucose consumption, and therefore might be applied in cancer cell bioimaging and bioassay in cancer studies.

Structure-based design and synthesis of imidazo[1,2-a]pyridine derivatives as novel and potent Nek2 inhibitors with in vitro and in vivo antitumor activities.

We present herein the discovery and development of novel and potent Nek2 inhibitors with distinctive in vitro and in vivo antitumor activity based on an imidazo[1,2-a]pyridine scaffold. Our studies identified a nonlinear SAR for activity against both Nek2 and cancer cells. Bioisostere and structure-based design techniques were employed to identify compounds 42c (MBM-17, IC50 = 3.0 nM) and 42g (MBM-55, IC50 = 1.0 nM), which displayed low nanomolar activity and excellent selectivity for Nek2. Both compounds effectively inhibited the proliferation of cancer cells by inducing cell cycle arrest and apoptosis. Importantly, the salts form of these two compounds (MBM-17S and MBM-55S) significantly suppressed tumor growth in vivo without apparent toxicity based on appearance and changes in body weight. In summary, MBM-17 and MBM-55 displayed the potential for substantial therapeutic application in cancer treatment.

Preclinical activity of MBM-5 in gastrointestinal cancer by inhibiting NEK2 kinase activity.

NEK2 is a conserved mitotic regulator critical for cell cycle progression. Aberrant expression of NEK2 has been found in a variety of human cancers, making it an attractive molecular target for the design of novel anticancer therapeutics. In the present study, we have identified a novel compound MBM-5, which was found to bind to NEK2 with high affinity by docking simulations study. MBM-5 potently inhibited NEK2 kinase activity in vitro in a concentration-dependent manner. MBM-5 also suppressed cellular NEK2 kinase activity, as evidenced by the decreased phosphorylation of its substrate Hec1 on S165 in a concentration- and time-dependent manner. This inhibition impeded mitotic progression by inducing chromosome segregation defects and cytokinesis failure; therefore leading to accumulation of cells with ≥4N DNA content, which finally underwent apoptosis. More importantly, MBM-5 treatment effectively suppressed the tumor growth of human gastric and colorectal cancer cells xenografts. Taken together, we demonstrated that MBM-5 effectively inhibited the kinase activity of NEK2 and showed a potential application in anti-cancer treatment regimens.

In silico analysis on structure and DNA binding mode of AtNAC1, a NAC transcription factor from Arabidopsis thaliana.

NAC (NAM/ATAF/CUC) transcription factors regulate the expression of the target genes by formation of NAC-DNA complex, which are involved in development, stress responses and nutrient distribution in many metaphyta plants. AtNAC1, a NAC transcription factor from Arabidopsis thaliana, plays an important role in auxin signaling and root development. In order to understand the structure and DNA binding model of AtNAC1, the 3D structure model of AtNAC1 was constructed and docked with its target DNA. The structure of AtNAC1 monomer contained four α-helices and eight ß-sheets. Two homo monomers of AtNAC1 formed a homo-dimer. The N-terminal sheet S1, Arg24 and Glu31 played an important role in forming AtNAC1 homo-dimer. AtNAC1 dimer interacted with DNA via its core ß-sheet (S5) which contained WKATGKD motif inserting into the major groove of DNA and formed a tight AtNAC1-DNA complex. The DNA sites for AtNAC1 binding were 5'-CTGACGTA-3' and 5'-GATGACGC-3'. Lys102, Ala103, Thr104, Gly105, Lys106, and Asp107 interacting with sugars/bases of DNA were probably responsible for specific recognition of DNA sites. Meanwhile, Arg91, Lys135, and Lys171 binding with phosphate groups of DNA backbone might be the key residues for affinity with DNA. The study provided the in silico framework to understand the interactions of AtNAC1 with DNA at the molecular level.