Design, synthesis and evaluation of N3-substituted quinazolinone derivatives as potential Bloom's Syndrome protein (BLM) helicase inhibitor for sensitization treatment of colorectal cancer.

The homologous recombination repair (HRR) pathway is critical for repairing double-strand breaks (DSB). Inhibition of the HRR pathway is usually considered a promising strategy for anticancer therapy. The Bloom's Syndrome Protein (BLM), a DNA helicase, is essential for promoting the HRR pathway. Previously, we discovered quinazolinone derivative 9h as a potential BLM inhibitor, which suppressed the proliferation of colorectal cancer (CRC) cell HCT116. Herein, a new series of quinazolinone derivatives with N3-substitution was designed and synthesized to improve the anticancer activity and explore the structure-activity relationship (SAR). After evaluating their BLM inhibitory activity, the SAR was discussed, leading to identifying compound 21 as a promising BLM inhibitor. 21 exhibited the potent BLM-dependent cytotoxicity against the CRC cells but weak against normal cells. Further evaluation revealed that 21 could disrupt the HRR level while inhibiting BLM located on the DSB site and trigger DNA damage in the CRC cells. This compound effectively suppressed the proliferation and invasion of CRC cells, along with cell cycle arrest and apoptosis. Consequently, 21 might be a promising candidate for treating CRC, and the BLM might be a new potential therapeutic target for CRC.

Pea pod-mimicking hydroxyapatite nanowhisker-reinforced poly(lactic acid) composites with bone-like strength.

The anisotropic hierarchical structures of naturally derived materials have offered useful design principles for the fabrication of high-strength and functional materials. Herein, we unraveled a structure-by-bionics approach to construction of pea pod-mimicking architecture for poly(lactic acid) (PLA) composites impregnated with hydroxyapatite nanowhiskers (HANWs). The HANWs (length of 80-120 nm, diameter of ~30 nm) were customized using microwave-assisted aqueous biomineralization at minute level, which were incorporated into PLA microfibers by electrospinning with filler loadings of 10-30 wt%. The membranes comprising HANW-modified PLA microfibers were stacked and structured into composite films, strategically involving high-pressure compression at a relatively low temperature to impart the confined structuring mechanisms. It thus allowed partial melting and thinning of PLA microfibers into nanofibers, onto which the discrete HANWs were tightly adhered and embedded, showing distinguished architectural configurations identical with pea pod. More importantly, the mechanical properties and bioactivity were remarkably promoted, as demonstrated by the increments of over 54 % and nearly 72 % for the yield strength and elastic modulus (71.6 and 2547 MPa) of the structured composite loaded 30 wt% HANWs compared to those of pure PLA (46.4 and 1484 MPa), as accompanied by significant improvements in the bioactivity to nucleate and create apatite entities in mineral solution. The unusual combination of excellent biological characteristics and bone-like mechanical elasticity and extensibility make the structured PLA composites promising for guided bone/tissue regeneration therapy.

Chinese Patent Medicine Liuweiwuling Tablet had Potent Inhibitory Effects on Both Wild-Type and Entecavir-Resistant Hepatitis B Virus (HBV) in vitro and Effectively Suppressed HBV Replication in Mouse Model.

Liuweiwuling Tablet (LWWL) is a licensed Chinese patent medicine (approval number: Z20060238) included in the national health insurance for anti-inflammation of chronic HBV infection, whereas its anti-HBV effect remains clarification. The study aimed to clarify its antiviral effect and related mechanisms. HepG2.2.15 cells (wild-type HBV-replicating cells) and HepG2. A64 cells (entecavir-resistant HBV-replicating cells) were used for in vitro test. Hydrodynamic injection-mediated HBV-replicating mouse model was used for in vivo test. Active compounds and related mechanisms for antiviral effect of LWWL were analyzed using network pharmacology and transcriptomics. The inhibition rates of LWWL (0.8 mg/ml) on HBV DNA, HBsAg, and pgRNA were 57.06, 38.55, and 62.49% in HepG2.2.15 cells, and 51.57, 17.57, and 53.88% in HepG2. A64 cells, respectively. LWWL (2 g kg-1 d-1 for 4 weeks)-treated mice had 1.16 log10 IU/mL decrease of serum HBV DNA, and more than 50% decrease of serum HBsAg/HBeAg and hepatic HBsAg/HBcAg. Compared to tenofovir control, LWWL was less effective in suppressing HBV DNA but more effective in suppressing HBV antigens. Thirteen differentially-expressed genes were found in relation to HBV-host interaction and some of them were enriched in interferon (IFN)-ß pathway in LWWL-treated HepG2.2.15 cells. CD3+CD4+ T-cell frequency and serum IFN-γ were significantly increased in LWWL-treated mice compared to LWWL-untreated mice. Among 26 compounds with potential anti-HBV effects that were predicted by network pharmacology, four compounds (quercetin, luteolin, wogonin, and kaempferol) were experimentally confirmed to have antiviral potency. In conclusion, LWWL had potent inhibitory effect on both wild-type and entecavir-resistant HBV, which might be associated with increasing IFN-ß and IFN-γ production.

Design, Synthesis, and Evaluation of New Quinazolinone Derivatives that Inhibit Bloom Syndrome Protein (BLM) Helicase, Trigger DNA Damage at the Telomere Region, and Synergize with PARP Inhibitors.

DNA damage response (DDR) pathways are crucial for the survival of cancer cells and are attractive targets for cancer therapy. Bloom syndrome protein (BLM) is a DNA helicase that performs important roles in DDR pathways. Our previous study discovered an effective new BLM inhibitor with a quinazolinone scaffold by a screening assay. Herein, to better understand the structure-activity relationship (SAR) and biological roles of the BLM inhibitor, a series of new derivatives were designed, synthesized, and evaluated based on this scaffold. Among them, compound 9h exhibited nanomolar inhibitory activity and binding affinity for BLM. 9h could effectively disrupt BLM recruitment to DNA in cells. Furthermore, 9h inhibited the proliferation of the colorectal cell line HCT116 by significantly triggering DNA damage in the telomere region and inducing apoptosis, especially in combination with a poly (ADP-ribose) polymerase (PARP) inhibitor. This result suggested a synthetic lethal effect between the BLM and PARP inhibitors in DDR pathways.

Cannabinoid type 2 receptor agonist JWH133 decreases blood pressure of spontaneously hypertensive rats through relieving inflammation in the rostral ventrolateral medulla of the brain.

OBJECTIVE: Neuroinflammation in the rostral ventrolateral medulla (RVLM) has been reported to be associated with hypertension. The upregulation and activation of the cannabinoid type 2 (CB2) receptor may be part of the active process of limiting or downregulating the inflammatory process. This study was designed to determine the role of the CB2 receptor in blood pressure (BP) through relieving neuroinflammation in the RVLM in spontaneously hypertensive rats (SHRs). METHODS: The long-term effects of intracerebroventricular injection of JWH133, a selective CB2 receptor agonist, on BP, heart rate (HR) and renal sympathetic nerve activity (RSNA) in SHR and Wistar-Kyoto (WKY) rats were determined. ELISA was used to measure the levels of proinflammatory cytokines, and western blotting was employed to detect protein expression of the CB2 receptor. Immunofluorescence staining was used to localize the CB2 receptor. Gene silencing of the CB2 receptor was realized by injecting adeno-associated virus (AAV) expressing CB2-specific shRNA (AAV2-r-CB2shRNA) into the RVLM. RESULTS: We found that SHRs exhibited higher levels of basal BP, HR, RSNA and proinflammatory cytokines (TNFα, IL-6 and IL-1ß) than those in WKY rats. The protein level of the CB2 receptor in the RVLM was robustly increased in SHRs. In addition, the CB2 receptor was mainly expressed on microglia cells of SHRs but not in WKY rats. No expression of the CB2 receptor was found on neurons of either WKY rats or SHRs. Furthermore, intracerebroventricular injection of JWH133 (1 mmol/l, 10 µl) for 28 days decreased the BP, HR, RSNA and proinflammatory cytokines significantly in SHRs, but it had no such effects in WKY rats. These effects were abolished by microinjection of 300 nl AAV2-r-CB2shRNA into the RVLM to knock down the CB2 receptor. CONCLUSION: Taken together, our results suggest that exciting the CB2 receptor relieves proinflammatory cytokine levels in the RVLM to decrease the BP, HR and RSNA in SHRs.

Discovery of Isaindigotone Derivatives as Novel Bloom's Syndrome Protein (BLM) Helicase Inhibitors That Disrupt the BLM/DNA Interactions and Regulate the Homologous Recombination Repair.

Homologous recombination repair (HRR), a crucial approach in DNA damage repair, is an attractive target in cancer therapy and drug design. The Bloom syndrome protein (BLM) is a 3'-5' DNA helicase that performs an important role in HRR regulation. However, limited studies about BLM inhibitors and their biological effects have been reported. Here, we identified a class of isaindigotone derivatives as novel BLM inhibitors by synthesis, screening, and evaluating. Among them, compound 29 was found as an effective BLM inhibitor with a high binding affinity and good inhibitory effect on BLM. Cellular evaluation indicated that 29 effectively disrupted the recruitment of BLM at DNA double-strand break sites, promoted an accumulation of RAD51, and regulated the HRR process. Meanwhile, 29 significantly induced DNA damage responses, as well as apoptosis and proliferation arrest in cancer cells. Our finding provides a potential anticancer strategy based on interfering with BLM via small molecules.