Ferroptosis boosted oral cancer photodynamic therapy by carrier-free Sorafenib-Ce6 self-assembly nanoparticles.

Oral cancer is a disease with high morbidity and mortality worldwide and greatly impacts the quality of life, especially in patients with advanced stages. Photodynamic therapy (PDT) is one of the most effective clinical treatments for oral cancers. However, most clinically applied photosensitizers have several deficiencies, including oxygen dependence, poor aqueous solubility, and a lack of tumor-targeting ability. Herein, the carrier-free multifunctional Sorafenib (Sor), chlorin e6 (Ce6), and Fe3+ self-assembly co-delivery nanoparticles (Sor-Ce6 NPs) were constructed via combining a ferroptosis inducer Sor and a photosensitizer Ce6 for synergetic therapy. The as-synthesized Sor-Ce6 NPs presented excellent colloidal stability and water dispersity with good in vivo tumor-targeting ability. More significantly, the low dose of Sor-Ce6 NPs had little dark toxicity but produced significantly enhanced ROS and supplied O2 sustainably to increase phototoxicity through ferroptosis pathway. Notably, the Sor-Ce6 NPs showed significantly higher in vitro and in vivo anti-tumor efficacy than the Sor/Ce6 mixture due to the improvement of cellular uptake and the incorporation of foreign Fe ions in the system, which also confer the T1 magnetic resonance-guided imaging ability to the formed Sor-Ce6 NPs. Our study demonstrates a promising self-assembled strategy for overcoming hypoxia-related PDT resistance for oral cancer treatment.

NK-derived exosome miR-1249-3p inhibits Mycobacterium tuberculosis survival in macrophages by targeting SKOR1.

Murine Natural Killer cells were cultivated in vitro to isolate NK-derived exosomes. Subsequent quantification via qPCR confirmed enrichment of miR-1249-3p. Ana-1 murine macrophages were cultured in vitro and subsequently inoculated with Mycobacterium tuberculosis (MTB) strain H37Rv. NK-exo and NK-exo miR-1249-3p were separately applied to the infection model, followed by immunological assays conducted post-48-hour co-culture. Western blot analyses corroborated that NK-exo exhibited exosomal marker proteins Granzyme A (GzmA), Granzyme B (GzmB), and Perforin (PFN), alongside a notable enrichment of miR-1249-3p. Functionally, NK-exo augmented the expression levels of Caspase-9,-8, and -3, as well as PARP, while attenuating the expression of NLRP3, ASC, and Cleaved-Caspase-1. Furthermore, qPCR demonstrated an up-regulation of Caspase-9, -8, and -3, along with pro-apoptotic factors Bax and Bid, and a concomitant down-regulation of the anti-apoptotic factor Bcl-2. The expression levels of inflammatory markers ASC, NLRP3, Cleaved-Caspase-1, and IL-1ß were concomitantly decreased. ELISA findings indicated diminished levels of TNF-α and ROS secretion. NK-exo miR-1249-3p specifically targeted and attenuated the expression of SKOR-1, engendering up-regulation of apoptosis-associated proteins and down-regulation of inflammation-related proteins, consequently affecting cellular fate.Our empirical evidence substantiates that NK-exo induces macrophage apoptosis, thereby mitigating MTB survival. Furthermore, NK-exo miR-1249-3p directly targets and inhibits SKOR-1 expression, leading to macrophage apoptosis and consequently hampering the proliferation of MTB. The data implicate the potential therapeutic relevance of NK-exo and miR-1249-3p in managing drug-resistant tuberculosis.

Discovery of X10g as a selective PROTAC degrader of Hsp90α protein for treating breast cancer.

Heat shock protein 90 (Hsp90), a highly conserved and widely expressed molecular chaperone, is mainly responsible for maintaining the correct folding of client proteins and is closely related to the stability and activation of tumour-related proteins. Hsp90α, the major isoform of Hsp90, can promote tumour cell migration and metastasis, and is abundantly secreted in highly invasive tumours. To date, most pan-Hsp90 inhibitors have been limited in their applications due to high toxicity. Herein, we described the candidate compound X10g based on a proteolysis-targeting chimaera (PROTAC) strategy that potently and selectively degraded Hsp90α. The results showed that X10g inhibited tumours better with lower toxicity in vivo. These findings demonstrate that synthesized selective Hsp90α degrader X10g provides a new strategy for breast cancer therapy.

Synthesis of Novel Dual Target Inhibitors of CDK12 and PARP1 and Their Antitumor Activities in HER2-Positive Breast Cancers.

Several anti-human epidermal growth factor receptor 2 (HER2) treatments have improved the landscape of HER2-positive breast cancer (BC) over the past few years; due to the heterogeneity of the disease itself, the drug resistance mechanisms and relapse are still the main issue in HER2-positive BC. Here, we intended to target simultaneous inhibition of both poly ADP-ribose polymerase 1 (PARP1) and cyclin-dependent kinase 12 (CDK12) that have had an impact on this disease up to their implementation in clinical practice. We successfully screened PARP1 inhibitors (PARPis) containing bicyclic tetrahydropyridine pyrimidines with antitumor activity. Most synthesized compounds with various alcohols were more effective at killing tumor cells than olaparib (ola), especially in HER2-positive cancer cells. Among them, compound 9 showed potent inhibitory effects on PARP1 enzymatic activity and the PAR protein level; moreover, the expression of CDK12 was inhibited by compound 9. Overall, compound 9 exhibited a significant antitumor effect by inhibiting DNA damage repair in tumors.

Albumin-encapsulated HSP90-PROTAC BP3 nanoparticles not only retain protein degradation ability but also enhance the antitumour activity of BP3 in vivo.

Proteolysis-targeting chimaera (PROTAC) has received extensive attention in industry. However, there are still some limitations that hinder its further development. In a previous study, our group first demonstrated that the HSP90 degrader BP3 synthesised by the principle of PROTACs showed therapeutic potential for cancer. However, its application was hindered by its high molecular weight and water insolubility. Herein, we aimed to improve these properties of HSP90-PROTAC BP3 by encapsulating it into human serum albumin nanoparticles (BP3@HSA NPs). The results demonstrated that BP3@HSA NPs showed a uniform spherical shape with a size of 141.01 ± 1.07 nm and polydispersity index < 0.2; moreover, BP3@HSA NPs were more readily taken up by breast cancer cells and had a stronger inhibitory effect in vitro than free BP3. BP3@HSA NPs also demonstrated the ability to degrade HSP90. Mechanistically, the improved inhibitory effect of BP3@HSA NPs on breast cancer cells was related to its stronger ability to induce cell cycle arrest and apoptosis. Furthermore, BP3@HSA NPs improved PK properties and showed stronger tumour suppression in mice. Taken together, this study demonstrated that hydrophobic HSP90-PROTAC BP3 nanoparticles encapsulated by human serum albumin could improve the safety and antitumour efficacy of BP3.

A PARP1 PROTAC as a novel strategy against PARP inhibitor resistance via promotion of ferroptosis in p53-positive breast cancer.

Therapeutic targeting of the nuclear enzyme poly (ADP-ribose) polymerase 1 (PARP1) with PARP inhibitors (PARPis) in patients with a homologous recombination (HR)- deficient phenotype based on the mechanism of synthetic lethality has been shown tremendous success in cancer therapy. With the clinical use of various PARPis, emerging evidence has shown that some PARPis offer hope for breakthroughs in triple-negative breast cancer (TNBC) therapy, regardless of HR status. However, similar to other conventional cytotoxic drugs, PARPis are also subject to the intractable problem of drug resistance. Notably, acquired resistance to PARPis caused by point mutations in the PARP1 protein is hard to overcome with current strategies. To explore modalities to overcome resistance and identify patients who are most likely to benefit from PARP1-targeted therapy, we developed a proteolysis-targeted chimaera (PROTAC) to degrade mutant PARP1 in TNBC. Here, we investigated a PARP1 PROTAC termed "NN3″, which triggered ubiquitination and proteasome-mediated degradation of PARP1. Moreover, NN3 degraded PARP1 with resistance-related mutations. Interestingly, compared with other reported PARP1 degraders, NN3 exhibited a unique antitumor mechanism in p53-positive breast cancer cells that effectively promoted ferroptosis by downregulating the SLC7A11 pathway. Furthermore, NN3 showed potent activity and low toxicity in vivo. In conclusion, we propose PROTAC-mediated degradation of PARP1 as a novel strategy against mutation-related PARPi resistance and a paradigm for targeting breast cancer with functional p53 via ferroptosis induction.

Discovery of CN0 as a novel proteolysis-targeting chimera (PROTAC) degrader of PARP1 that can activate the cGAS/STING immunity pathway combined with daunorubicin.

Poly ADP-ribose polymerase 1 (PARP1) plays an essential role in DNA repair signaling, rendering it an attractive target for cancer treatment. Despite the success of PARP1 inhibitors (PARPis), only a few patients can currently benefit from PARPis. Moreover, drug resistance to PARPis occurs during clinical treatment. Natural and acquired resistance to PARPis has forced us to seek new therapeutic approaches that target PARP1. Here, we synthesized a series of compounds by proteolysis-targeting chimera (PROTAC) technology to directly degrade the PARP1 protein. We found that CN0 (compound 3) with no polyethylene glycol (PEG) linker can degrade the PARP1 protein through the proteasome pathway. More importantly, CN0 could inhibit DNA damage repair, resulting in highly efficient accumulation of cytosolic DNA fragments due to unresolved unrepaired DNA lesions when combined with daunorubicin (DNR). Therefore, CN0 can activate the cyclic GMP-AMP synthase/stimulator of the interferon gene (cGAS/STING) pathway of innate immunity and then spread the resulting inflammatory signals, thereby reshaping the tumor microenvironment, which may eventually enhance T cell killing of tumor cells.

Synthesis of novel dual target inhibitors of PARP and EGFR and their antitumor activities in triple negative breast cancers.

The therapeutic strategy of poly (ADP-ribose) polymerase (PARP) inhibition of BRCA1/2 mutant cancers has been overwhelmingly successful, however, the highly aggressive triple negative breast cancers (TNBC) that receptor protein tyrosine kinase (RTKs) is known to be overexpressed are not sensitive to PARP inhibitors. Our research focused on exploring PARP inhibitors incorporating a bicyclic tetrahydropyridine pyrimidine. All synthesized compounds were more potent than Olaparib (ola) in killing tumor cells, especially in TNBC. Furthermore, compound 7 exhibited strong inhibitory effects on PARP enzymatic activity, moreover, the expression of EGFR and phosphorylated EGFR was inhibited by compound 7. Therefore, compound 7 can effectively inhibit TNBC cells with high expression of EGFR. In addition, significant synergistic effect of anti-tumor effect of new PARP inhibitors and adriamycin was also observed.

Protective Effect of Rifampicin Loaded by HPMA-PLA Nanopolymer on Macrophages Infected with Mycobacterium Tuberculosis.

PURPOSE: This research was designed to investigate the protective effect of rifampicin (RIF) loaded by N-(2-hydroxypropyl) methylacrylamide- (HPMA-) polylactic acid (PLA) nanopolymer on macrophages infected with Mycobacterium tuberculosis (MTB). METHODS: We first induced H37Rv to infect macrophages to build a cell model. Then, the HPMA-PLA nanopolymer loaded with RIF was prepared to treat MTB-infected macrophages. The macrophage activity was tested by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the nitric oxide (NO) in cells was measured through Griess reagent, and the bacterial activity of MTB was observed via the colony-forming unit (CFU) assay. The inflammation-related factors in cells were detected via the enzyme-linked immunosorbent assay (ELISA), the apoptosis of macrophages was examined via flow cytometry, and the expression of apoptosis-related proteins was determined by western blot (WB). RESULTS: HPMA-PLA had no obvious toxicity to macrophages. The expression of NO and inflammatory factors in macrophages infected with MTB increased significantly, but the apoptosis rate was not significantly different from that of uninfected cells. However, after treatment with HPMA-PLA-RIF or free RIF, the inflammatory reaction of infected cells was inhibited, the expression of NO was decreased, the apoptosis rate was increased, and the bacterial activity in cells was decreased, with statistically significant differences; moreover, HPMA-PLA-RIF was more effective than free RIF. CONCLUSIONS: HPMA-PLA-RIF has a high protective effect on macrophages infected with MTB, with high safety. Its protective mechanism is at least partly through inhibiting the production of NO and inflammatory response, which can inhibit bacterial activity and induce cell apoptosis.

Positive Feedback Regulation of Poly(ADP-ribose) Polymerase 1 and the DNA-PK Catalytic Subunit Affects the Sensitivity of Nasopharyngeal Carcinoma to Etoposide.

Etoposide (VP-16) is used for the treatment of various cancers, including nasopharyngeal carcinoma (NPC); however, cancers develop resistance to this agent by promoting DNA repair. The DNA-PK (DNA-PKcs) catalytic subunit and poly(ADP-ribose) polymerase 1 (PARP1) mediate acquired resistance and poor survival in NPC cells exposed to DNA damaging agents. DNA repair can alter the sensitivity of NPC cells to DNA damaging agents, and these two enzymes function concomitantly in response to DNA damage in vivo. Therefore, we explored the relationship between DNA-PKcs and PARP1, which may affect NPC cell survival by regulating DNA repair after VP-16 treatment. We performed quantitative real-time polymerase chain reaction, western blotting, and enzyme-linked immunoassays and found that DNA-PKcs knockdown downregulated the PARP1 and PAR expression. Conversely, PARP1 knockdown reduced DNA-PKcs activity, indicating the mutual regulation between DNA-PKcs and PARP1 in VP-16-induced DNA repair. Moreover, a combination treatment with olaparib (a PARP1 inhibitor) and NU7441 (a DNA-PKcs inhibitor) sensitized NPC cells to VP-16 in vitro and in vivo, suggesting that the combined treatment of olaparib, NU7441, and a DNA-damaging agent may be a successful treatment regimen in patients with NPC.

Discovery of BP3 as an efficacious proteolysis targeting chimera (PROTAC) degrader of HSP90 for treating breast cancer.

Heat shock protein 90 (HSP90) is involved in the stabilization and activation of oncoproteins, rendering it essential for oncogenic transformation. However, the HSP90 inhibitors evaluated to date have not led to the expected effects in cancer therapy. Herein, we systematically described the design, synthesis, and evaluation of HSP90 degraders based upon the proteolysis-targeting chimera (PROTAC) strategy. The results showed that the candidate compound 16b (BP3) potently degraded HSP90 and effectively inhibited the growth of human breast cancer cells. When used as a single agent, BP3 led to effective tumor suppression in mice. These findings demonstrate that our HSP90-targeting PROTAC strategy has potential novel applications in breast cancer therapy.

MiR-519d-5p modulates the sensitivity of breast cancer to chemotherapy by forming a negative feedback loop with RELA.

BACKGROUND: The chemoresistance of breast cancer (BC) has become the main cause of treatment failure. MicroRNAs (miRNAs) play a critical role in tumorigenesis, development, and chemoresistance, but the underlying mechanism of miR-519d in BC development and chemotherapy sensitivity remains to be elucidated. METHODS: The levels of miR-519d-5p in BC samples and cell lines were measured by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Cell viability was monitored by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The in vivo effect of miR-519d-5p on tumor formation and doxorubicin response were investigated in a xenograft study. Bioinformatic analysis, luciferase reporter assay, RT-qPCR, and western blotting were conducted to validate RELA as a target gene of miR-519d-5p. We performed RT-qPCR, western blotting, chromatin immunoprecipitation (ChIP), and DNA pull down to verify miR-519d-5p as a transcriptional target of RELA. RESULTS: This study found that miR-519d-5p was expressed at lower levels in BC cells and tissues, and overexpression of miR-519d-5p sensitized BC to chemotherapy both in vitro and in vivo. Meanwhile, the expression of RELA was negatively correlated with miR-519d-5p. We then showed that RELA is one of the targets of miR-519d-5p: miR-519d-5p inhibited RELA expression by directly binding to its 3'-unstranslated region (3'-UTR). Conversely, it was verified that miR-519d-5p is one of the targets of transcription factor RELA, and RELA repressed miR-519d-5p by binding to the promoter region of miR-519d-5p, which forms a feedback loop. CONCLUSIONS: Overall, the results provide a novel therapeutic strategy for the combinational use of miR-519d-5p and chemotherapeutic agents to overcome chemo-resistance by forming a negative feedback loop with RELA.

Effect and Mechanism of Mycobacterium tuberculosis Lipoprotein LpqH in NLRP3 Inflammasome Activation in Mouse Ana-1 Macrophage.

The study is aimed at investigating the role and mechanism of LpqH of Mycobacterium tuberculosis in the activation of NLRP3 inflammasome in mouse Ana-1 macrophages. ExPASy-ProtParam, PHYRE2, ABCpred, and SYFPEITHI were used to predict and analyze the physicochemical properties, protein structure, and B cell/T cell-associated epitopes of LpqH protein. The recombinant LpqH protein was purified, and its immunoreactivity was analyzed with western blot. The LPS-treated mouse Ana-1 macrophages were incubated with purified LpqH protein directly. The expression of NLRP3, ASC, and caspase-1 protein was detected by western blot. The secretion of IL-1ß was detected by ELISA, and LDH was detected by a kit. Cell death was detected by flow cytometry. LpqH consisted of 159 amino acids and was a hydrophobic protein with stable properties. Its secondary structure contained 47% random coils, 53% ß-sheets, and 3% α-helix. The tertiary structure showed a relatively loose spatial conformation. Additionally, it had 8 B cell epitopes (score > 0.8) and 10 CTL cell epitopes (score ≥ 20). The recombinant LpqH, which had strong immunoreactivity, significantly increased the levels of NLRP3, ASC, and caspase-1 p20 (P < 0.01) and promoted the secretion of IL-1ß by the cells (P < 0.01). In addition, high concentration of KCl significantly inhibited the effect of LpqH on mouse Ana-1 macrophages and reduced the expression of NLRP3, ASC, and caspase-1 p20 (P < 0.01). However, there was no significant change in LDH (P > 0.05). Meanwhile, LpqH protein did not cause additional cell death (P > 0.05). LpqH protein has good immunogenicity and can activate the NLRP3 inflammasome through the potassium efflux pathway without causing cell death.

Enhanced Chemotherapeutic Efficacy of PLGA-Encapsulated Epigallocatechin Gallate (EGCG) Against Human Lung Cancer.

PURPOSE: Currently, the clinical benefits of tea polyphenols have contributed to the development of efficient systemic delivery systems with adequate bioavailability and stability. In this study, we aimed to establish a nanoparticle model to overcome the shortcomings of epigallocatechin gallate (EGCG) in the treatment of lung cancer. MATERIALS AND METHODS: Poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) loaded with EGCG were prepared by the oil-in-water emulsion solvent evaporation technique. The characteristics of NPs, entrapment efficiency, and in vitro release were systematically evaluated. The cellular uptake, cytotoxic activity, and the effect of the formulation on cellular apoptosis of free-from EGCG and the NPs were compared. The interaction between protein-NF-κB and EGCG was detected by bio-layer interferometry (BLI). NF-κB signaling was evaluated by Western blotting and q-RT-PCR. The efficacy of the optimized nanoformulation was evaluated using a patient-derived tumor xenograft (PDX) model. RESULTS: EGCG-loaded NPs (175.8±3.8 nm in size) demonstrated its optimal efficacy, with approximately 86.0% of encapsulation efficiency and 14.2% of loading efficiency. Additionally, EGCG-encapsulated PLGA-NPs offered a 3-4-fold dose advantage compared to free EGCG in terms of exerting antiproliferative effects and inducing apoptosis at lower doses (12.5, 25 µM). Molecular interaction assays demonstrated that EGCG binds to NF-κB with high affnity (KD=4.8×10-5 M). EGCG-NPs were more effective at inhibiting NF-κB activation and suppressing the expression of NF-κB-regulated genes than free EGCG. Furthermore, EGCG-NPs showed superior anticancer activity in the PDX model than free EGCG. CONCLUSION: These findings indicated that the prepared EGCG-NPs were more effective than free EGCG in inhibiting lung cancer tumors in the PDX model.

The role of the novel LincRNA uc002jit.1 in NF-kB-mediated DNA damage repair in acute myeloid leukemia cells.

The roles and therapeutic potential of long noncoding RNAs (lncRNAs) in acute myeloid leukemia (AML) have attracted increased attention. However, many lncRNAs have not been annotated in AML, and their predictive value for AML therapy remains unclear. In this study, we identified a novel large intergenic noncoding RNA uc002jit.1 (D43770) from a lncRNA microarray. We first proved uc002jit.1 is a target gene of nuclear factor kappa B/RELA, RELA regulated uc002jit.1 transcription by binding to its promoter. Additionally, uc002jit.1 knockdown impaired the stability of poly (ADP-ribose) polymerase 1 (PARP1) mRNA, and then reduced PARP1 protein content and PARylation level upon DNA damage, thus inhibiting DNA damage repair in AML cells. Moreover, uc002jit.1 knockdown significantly inhibited AML cells proliferation and increased the sensitivity to chemotherapeutic drugs in vitro as well as in a mouse model in vivo. Overall, our study indicated that uc002jit.1 may be associated with the occurrence and prognosis of AML and could be a new diagnostic/prognostic biomarker and therapeutic target for AML.

Synthesis of novel dual target inhibitors of PARP and HSP90 and their antitumor activities.

Poly (ADP-ribose) polymerase (PARP) inhibitors have achieved great success in clinical application, especially for the prolonged survival of cisplatin-sensitive ovarian cancer patients. However, there are still many patients who do not respond to PARP inhibitors. Novel PARP inhibitors with higher activity are urgently needed. Herein we report a series of compounds by molecular hybridization PARP-1 inhibitor Olaparib (Ola) with HSP90 inhibitor C0817 (one curcumin derivative). All synthesized compounds were evaluated for their antiproliferative activity in vitro, and some were further assessed for their inhibitory activities of the PARP enzyme and HSP90 affinity. Our results indicated that compound 4 could bind to HSP90 and cause static quenching, indicating that compound 4 was able to bind to HSP90, moreover, downstream molecular breast cancer 1 (BRAC-1) was reduced. In conclusion, dual target inhibitors of PARP and HSP90 exhibited stronger selective cytotoxicities against cancer.

Synergistic inhibition of lung cancer cells by EGCG and NF-κB inhibitor BAY11-7082.

Lung cancer has a poor 5-year survival rate and is the leading cause of cancer-related deaths worldwide. Thus, the development of more efficient therapeutic strategies is urgently needed. Many studies have shown that EGCG, a major polyphenol found in green tea, has potential anticancer effects. The present study aims to investigate the molecular mechanism of EGCG-mediated inhibition of proliferation in lung cancer cells and to explore the effects of combined treatment with EGCG and an NF-κB inhibitor, BAY11-7082, in A549 and H1299 cells both in vitro and in vivo. Our results showed that EGCG inhibits cell proliferation and migration and induces apoptosis in A549 and H1299 cells at relatively high concentrations (IC50=86.4 µM for A549 cells and 80.6 µM for H1299 cells). These effects are partially achieved via inhibition of the NF-κB signaling pathway. Combined treatment with EGCG and BAY11-7082, a potent NF-κB inhibitor, shows significant synergistic effects at relatively low concentrations. The inhibition rate reached approximately 50% in cells treated for 72 h with 20 µM EGCG and 5 µM (A549 cells) or 2.5 µM BAY11-7082 (H1299 cells). This synergistic anti-tumor effect was also observed in a xenograft model. These results indicated that EGCG inhibits lung cancer cell proliferation by suppressing NF-κB signaling. Coadministration of EGCG and BAY11-7082 has a synergistic effect both in vitro and in vivo and may serve as a novel therapeutic strategy for lung cancer.

FM0807 decelerates experimental arthritis progression by inhibiting inflammatory responses and joint destruction via modulating NF-κB and MAPK pathways.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic articular synovial inflammatory disease. The precise etiology underlying the pathogenesis of RA remains unknown. We aimed to investigate the inhibitory effect of curcumin analog FM0807 (curcumin salicylate monoester, 2-hydroxy-, 4-[(1E,6E)-7-(4-hydroxy-3-methoxyphenyl)-3,5-dioxo-1,6-heptadien-1-yl]-2-methoxyphenyl ester) on experimental RA and investigate its possible mechanisms of action. METHOD: Rats with Freund's complete adjuvant (FCA)-induced arthritis (AIA) were administered aspirin (0.1 mmol.kg-1), curcumin (0.1 mmol.kg-1), FM0807 (0.1, 0.2 mmol.kg-1) and vehicle via gastric gavage, from days 7 to 21, once daily. The hind paw volume and arthritis index (AI) were measured, and radiographic and histological examinations were performed. Twenty-one days later, the animals were killed and left ankle joints were removed to measure protein expression of the elements of the nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) pathway by Western blot analysis. The enzyme-linked immunosorbent assay (ELISA) was employed to measure synovial fluid levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1ß and IL-10. RESULTS: Compared with AIA group, FM0807 reduced the AI and swelling of the injected hind paw in a dose-dependent manner, and inhibited increases in inflammatory cell infiltration, pannus formation and cartilage destruction. FM0807 also potently attenuated the increase in the expression of inflammatory factors TNF-α, IL-6 and IL-1ß in synovial fluid, while IL-10 levels were also elevated. FM0807 significantly suppressed phosphorylation of extracellular-signal-regulated kinase (ERK) 1/2 (ERK1/2), c-Jun-N-terminal kinase (JNK) 1/2 (JNK1/2), p38MAPK, inhibitor of NF-κB kinase (IKK), IκB and NF-κB p65 protein, (all P<0.05), which displayed more potential effects compared with those of the aspirin and curcumin groups. CONCLUSION: FM0807 exerts its therapeutic effects on RA by inhibiting cartilage degeneration. FM0807 treatment might be an effective therapeutic approach for RA.

In Vitro Biomechanical Study of Epidural Pressure during the Z-shape Elevating-Pulling Reduction Technique for Cervical Unilateral Locked Facets.

Objective: To analyze the mechanism of the halo vest-assisted Z-shape elevating-pulling reduction technique for cervical unilateral locked facets, and confirm the safety of the spinal cord under the epidural pressure that occurs during the reduction process. Methods: Eleven osteoligamentous whole coronal and cervical spine specimens were established as skull-neck-thorax models of cervical unilateral locked facets at the C5/6 level. The halo vest-assisted Z-shape elevating-pulling reduction technique was then applied to reduce the locked facets. The changes in the epidural pressure in five cervical positions (cervical physiological curvature, cervical lateral bending, cervical unilateral locked facets, cervical unilateral perched facets, and reduction) were measured by a pressure sensor during the reduction procedure. The models simultaneously underwent multi-angle radiographic examination and CT scanning. Results: Successful closed reduction was achieved via the halo vest-assisted Z-shape elevating-pulling reduction technique in all 11 models. The epidural pressure in the cervical unilateral locked facets position was significantly higher than that in the other four cervical positions (P < 0.005). There was no significant difference in the epidural pressures measured during cervical lateral bending, cervical unilateral perched facets, and reduction. Conclusions: Maximum epidural pressures were measured in the position of cervical unilateral locked facets. The halo vest-assisted Z-shape elevating-pulling reduction technique achieved spinal decompression without causing secondary spinal cord injury. The halo vest-assisted Z-shape elevating-pulling reduction technique is safe and effective, and has a high success rate of reduction.

NF-κB and Poly (ADP-ribose) Polymerase 1 Form a Positive Feedback Loop that Regulates DNA Repair in Acute Myeloid Leukemia Cells.

NF-κB mediates acquired resistance in acute myeloid leukemia (AML) cells treated with DNA-damaging agents. Because DNA repair is the major molecular shift that alters sensitivity to DNA-damaging agents, we explored whether activation of the NF-κB pathway promotes AML cell survival by regulating DNA repair after chemotherapy. Our results showed that RELA, an important subunit of NF-κB, regulated DNA repair by binding to the promoter region of the PARP1 gene and affecting PARP1 gene transcription. Conversely, PARP1 knockdown reduced NF-κB activity, indicating that NF-κB and PARP1 create a positive feedback loop in DNA repair. Simultaneous treatment with the NF-κB inhibitor BMS-345541 and the PARP1 inhibitor olaparib resulted in robust killing of AML cells. This dual inhibition significantly suppressed tumor growth and extended survival times in xenograft tumor models. IMPLICATIONS: RELA and PARP1 form a positive feedback loop to regulate DNA damage repair, simultaneous inhibition of NF-κB and PARP1 increases the antileukemic efficacy of daunorubicin in vitro and in vivo, broadening the use of PARP1 inhibitors.