Genome-edited rabbits: Unleashing the potential of a promising experimental animal model across diverse diseases.

Animal models are extensively used in all aspects of biomedical research, with substantial contributions to our understanding of diseases, the development of pharmaceuticals, and the exploration of gene functions. The field of genome modification in rabbits has progressed slowly. However, recent advancements, particularly in CRISPR/Cas9-related technologies, have catalyzed the successful development of various genome-edited rabbit models to mimic diverse diseases, including cardiovascular disorders, immunodeficiencies, aging-related ailments, neurological diseases, and ophthalmic pathologies. These models hold great promise in advancing biomedical research due to their closer physiological and biochemical resemblance to humans compared to mice. This review aims to summarize the novel gene-editing approaches currently available for rabbits and present the applications and prospects of such models in biomedicine, underscoring their impact and future potential in translational medicine.

Discovery of chiral 1,4-diarylazetidin-2-one-based hydroxamic acid derivatives as novel tubulin polymerization inhibitors with histone deacetylase inhibitory activity.

Tubulin and histone deacetylase have been clinically proven as promising targets for cancer therapy. Herein, we describe the design and synthesis of chiral 1,4-diarylazetidin-2-one-based hydroxamic acids as novel tubulin/HDAC dual inhibitors. Among them, compound 12a was validated to effectively disrupt tubulin polymerization, and exhibited potent HDAC1/8 inhibitory activities. Meanwhile, 12a showed good antiproliferative activities against four tumor cell lines. Further studies showed 12a works through blocking cellular cycle, inducing apoptosis and inhibiting colony formation. In addition, 12a has suitable physicochemical properties and high liver microsomal metabolic stability. Importantly, compound 12a was found to exhibit significant antitumor efficacy in vivo, thus warranting it as a promising tubulin/HDAC dual inhibitor for further development.

Discovery of a 2,6-diarylpyridine-based hydroxamic acid derivative as novel histone deacetylase 8 and tubulin dual inhibitor for the treatment of neuroblastoma.

Herein, two series of HDAC/tubulin dual inhibitors via introducing the key pharmacophore of HDAC inhibitor into the skeletons of 2,6-diarylpyridine and 2'-arylchalcone were synthesized. Among them, 2,6-diarylpyridine-based hydroxamic acid 10a exhibited good inhibitory activity against HDAC8 (IC50 = 117 nM) with 50-fold and 42-fold high selectivity relative to HDAC1 and HDAC6, respectively. Meanwhile, 10a disrupted tubulin polymerization effectively and exhibited potent antiproliferative activity against BE-(2)-C cell line, with IC50 value of 17 nM. Mechanism studies revealed that 10a blocked cell cycle, induced cellular apoptosis and suppressed colony formation. Moreover, 10a possessed good physicochemical properties and metabolic stability. Importantly, 10a exhibited better antitumor effects in human neuroblastoma xenograft mice model than those of clinical HDAC inhibitor and tubulin inhibitor, whether used alone or in combination. These results highlighted the advantages of the HDAC8/tubulin dual inhibitor 10a as an outstanding antitumor agent.

Targeting the tumor microenvironment by an enzyme-responsive prodrug of tubulin destabilizer for triple-negative breast cancer therapy with high safety.

In response to the long-term potential toxicity concerns of tubulin destabilizer, an enzyme-responsive prodrug therapy for triple-negative breast cancer was developed based on the different ß-glucuronidase levels between tumor and normal tissues in this study. All the prodrugs synthesized herein showed remarkable stability in phosphate buffer and bovine serum solution, among which 17a was found to be more susceptible to enzymatic cleavage. 17a exhibited excellent selectivity between the in vitro antiproliferative activities against ß-glucuronidase-pretreated and -untreated cancer cells (IC50 (+Enz) = 8.9-15.7 nM, IC50 (-Enz) > 50 µM), along with favorable liver microsomal metabolic stability and improved aqueous solubility. Furthermore, as a candidate prodrug 17a showed potent antitumor efficacy in MDA-MB-231 xenograft mouse model without causing perceptible injury to organs. Importantly, 17a exhibited superior safety profiles with higher LD50 value and no perceivable cardiotoxicity, which was a major dose-limiting adverse effect for the parent compound 1. These salient toxicity-reduced effects of 17a would merit further in-depth assessment of this compound for preclinical therapeutic usages.

Effect of Physical Properties of a Gas on the Refrigeration Temperature Drop of Vortex Tubes Used in Oil and Gas Fields.

The composition of natural gas can vary considerably across different oil and gas fields. Such compositional variation is primarily reflected in the distinctive physical properties of natural gas. However, during practical application in an oil and gas field, a refrigeration temperature drop in a vortex tube is often observed because vortex tubes generally have low intrinsic refrigeration efficiencies. When vortex tubes are applied in oil and gas fields, the utilization of the oil pressure of a natural gas wellhead is often desirable to avoid excessive energy usage from external devices. In this study, a numerical model of a vortex tube was developed, executed, and validated through laboratory experiments. The refrigeration temperature drop values of 12 gases with distinctive physical properties at a total inlet pressure of 0.3 MPa, an inlet temperature of 300 K, and a cooling mass flow ratio of 0.5 were analyzed. The importance of different physical properties was ranked based on the gray correlation method. Additionally, the synergetic effects of the physical properties on the refrigeration temperature drop were analyzed via regression fitting. The results indicate a significant impact of the gas physical properties on the refrigeration temperature drop in the vortex tube. The maximum and minimum refrigeration temperature drop obtained for different gases can differ by up to 16 K. Furthermore, the refrigeration temperature drop in the vortex tube does not change monotonically with any physical property. Instead, it depends on the synergetic effect from the physical properties, which have different levels of influence on it.

Design, synthesis and antitumor evaluation of novel chiral diaryl substituted azetidin-2-one derivatives as tubulin polymerization inhibitors.

A novel class of diaryl substituted azetidin-2-one derivatives were designed, asymmetrically synthesized, and evaluated for antiproliferative activities. The in vitro antitumor assay revealed that among the 4-aryl-substituted 1-(3,4,5-trimethoxyphenyl)azetidin-2-ones (B series), most possessed moderate to strong activities, with compound B7c that bears a 2-naphthyl substituent being the most potent one (IC50 0.16-0.40 µM) against a panel of human cancer cell lines. In contrast, none of the 3-(arylmethylene)-substituted 1-(3,4,5-trimethoxyphenyl)azetidin-2-ones (L series) showed significant activities in the assay. Further studies indicated that B7c inhibited tubulin polymerization, disrupted in vitro vascularization, blocked cell cycle progression at G2/M phase, induced cell apoptosis, decreased mitochondrial membrane potential, and increased the intracellular reactive oxygen species level in a dose-dependent way. Compound B7c also inhibited significantly tumor growth in a xenograft mice model with no obvious drop in the mice body weights. Collectively, these results suggested that B7c and its analogues should merit further investigation as new promising antitumor agents.

Bifunctional chiral selenium-containing 1,4-diarylazetidin-2-ones with potent antitumor activities by disrupting tubulin polymerization and inducing reactive oxygen species production.

Organoselenium compounds have attracted growing interests as promising antitumor agents over recent years. Herein, four series of novel selenium-containing chiral 1,4-diarylazetidin-2-ones were asymmetrically synthesized and biologically evaluated for antitumor activities. Among them, compound 7 was found to be about 10-fold more potent than its prototype compound 1a, and compound 9a exhibited the most potent cytotoxicity against five human cancer cell lines, including a paclitaxel-resistant human ovarian cancer cell line A2780T, with IC50 values ranging from 1 to 3 nM. Mechanistic studies revealed that compound 9a worked by disrupting tubulin polymerization, inducing reactive oxygen species (ROS) production, decreasing mitochondrial membrane potential, blocking the cell cycle in the G2/M phase, inducing cellular apoptosis and suppressing angiogenesis. Additionally, compound 9a exhibited appropriate human-microsomal metabolic stability and physicochemical properties. Importantly, compound 9a was found to inhibit tumor growth effectively in a xenograft mice model with low toxicity profile, which rendered 9a a highly promising candidate for further pre-clinical development.

Novel diaryl-2H-azirines: Antitumor hybrids for dual-targeting tubulin and DNA.

Multiple-target drugs may achieve better therapeutic effect via different pathways than single-target ones, especially for complex diseases. Tubulin and DNA are well-characterized molecular targets for anti-cancer drug development. A novel class of diaryl substituted 2H-azirines were designed based on combination of pharmacophores from Combretastatin A-4 (CA-4) and aziridine-type alkylating agents, which are known tubulin polymerization inhibitor and DNA damaging agents, respectively. The antitumor activities of these compounds were evaluated in vitro and 6h showed the most potent activities against four cancer cell lines with IC50 values ranging from 0.16 to 1.40 µM. Further mechanistic studies revealed that 6h worked as a bifunctional agent targeting both tubulin and DNA. In the nude mice xenograft model, 6h significantly inhibited the tumor growth with low toxicity, demonstrating the promising potential for further developing novel cancer therapy with a unique mechanism.

Design, Synthesis, and Activity Evaluation of Novel Acyclic Nucleosides as Potential Anticancer Agents In Vitro and In Vivo.

In the present work, 103 novel acyclic nucleosides were designed, synthesized, and evaluated for their anticancer activities in vitro and in vivo. The structure-activity relationship (SAR) studies revealed that most target compounds inhibited the growth of colon cancer cells in vitro, of which 3-(6-chloro-9H-purin-9-yl)dodecan-1-ol (9b) exhibited the most potent effect against the HCT-116 and SW480 cells with IC50 values of 0.89 and 1.15 µM, respectively. Furthermore, all of the (R)-configured acyclic nucleoside derivatives displayed more potent anticancer activity compared to their (S)-counterparts. Mechanistic studies revealed that compound 9b triggered apoptosis in the cancer cell lines via depolarization of the mitochondrial membrane and effectively inhibited colony formation. Importantly, compound 9b inhibited the growth of the SW480 xenograft in a mouse model with low systemic toxicity. These results indicated that acyclic nucleoside compounds are viable as potent and effective anticancer agents, and compound 9b may serve as a promising lead compound that merits further attention in future anticancer drug discovery.

Amentotaxins C-V, Structurally Diverse Diterpenoids from the Leaves and Twigs of the Vulnerable Conifer Amentotaxus argotaenia and Their Cytotoxic Effects.

A phytochemical investigation of the MeOH extract of the leaves and twigs of Amentotaxus argotaenia, a relict vulnerable coniferous species endemic to China, led to the isolation and characterization of 35 diterpenoids/norditerpenoids. Twenty of these are new, including 11 ent-kaurane-type (amentotaxins C-M, 1-11, respectively), three icetexane-type [= 9(10→20)abeo-abietane-type (amentotaxins N-P, 12-14, respectively)], four ent-labdane-type (amentotaxins Q-T, 15-18, respectively), and two isopimarane-type [amentotaxins U (19) and V (20)] compounds. Their structures were elucidated on the basis of spectroscopic data, single-crystal X-ray diffraction, the modified Mosher's method, and electronic circular dichroism data analyses. Compounds 1-9 are rare 18-nor-ent-kaurane-type diterpenoids featuring a 4ß,19-epoxy ring. All the isolates were evaluated for their cytotoxic effects against a small panel of cultured human cancer cell lines (HeLa, A-549, MDA-MB-231, SKOV3, Huh-7, and HCT-116), and some of them exhibited cytotoxicities with IC50 values ranging from 1.5 to 10.0 µM.

Discovery of a chiral fluorinated azetidin-2-one as a tubulin polymerisation inhibitor with potent antitumour efficacy.

Inhibition of tubulin polymerisation with small molecules has been clinically validated as a promising therapy for multiple solid tumours. Herein, a series of chiral azetidin-2-ones were asymmetrically synthesised and biologically evaluated for antitumour activities. Among them, a chiral fluorinated azetidin-2-one, 18, was found to exhibit the most potent activities against five cancer cell lines, including a drug-resistant cell line, with IC50 values ranging from 1.0 to 3.6 nM. Further mechanistic studies revealed that the compound 18 worked by disrupting tubulin polymerisation, blocking the cell cycle in the G2/M phase, inducing cellular apoptosis, and suppressing angiogenesis. Additionally, 18 exhibited higher human-microsomal metabolic stability and aqueous solubility compared to those of combretastatin A-4. Finally, 18 was also found to effectively inhibit tumour growth in a xenograft mice model with low toxicity and thus might be a promising lead for further clinical development.

Discovery of Novel Aryl Carboxamide Derivatives as Hypoxia-Inducible Factor 1α Signaling Inhibitors with Potent Activities of Anticancer Metastasis.

In order to discover novel hypoxia-inducible factor 1 (HIF-1) inhibitors for the cancer metastasis treatment, 68 new aryl carboxamide compounds were synthesized and evaluated for their inhibitory effect by dual luciferase-reporter assay. Based on five rounds of investigation on structure-activity relationships step by step, compound 30m was discovered as the most active inhibitor (IC50 = 0.32 µM) with no obvious cytotoxicity (CC50 > 50 µM). It effectively attenuated hypoxia-induced HIF-1α protein accumulation and reduced transcription of vascular epidermal growth factor in a dose-dependent manner, which was further demonstrated by its inhibitory potency on capillary-like tube formation, angiogenesis of zebrafish as well as cellular migration and invasion. Importantly, compound 30m exhibited antimetastatic potency in breast cancer lung metastasis in the mice model, indicating its promising therapeutic potential for prevention and treatment of tumor metastasis. These results definitely merit attention for further rational design of more efficient HIF-1 inhibitors in the future.

Design, synthesis, antitumor activities and biological studies of novel diaryl substituted fused heterocycles as dual ligands targeting tubulin and katanin.

Microtubule is one of the important targets for cancer treatment. A novel class of diaryl substituted imidazo[4,5-c]pyridin-2-ones and imidazo[4,5-c]pyridines were designed based on combination principles by merging the structures of ß-lactams and purine-type compounds known as tubulin polymerization inhibitor and katanin activity up-regulator, respectively. Their antitumor activities were evaluated in vitro and the mechanism was elucidated, leading to the identification of 1,6-diaryl-1H-imidazo[4,5-c]pyridin-2(3H)-one 20b as the first bifunctional agent that can target both tubulin and katanin simultaneously. The in vivo assays verified that compound 20b significantly inhibited xenograft tumor growth with good pharmacokinetic characteristics, demonstrating a promising potential for further development into anti-tumor drug candidates with a unique mechanism of dual-targeting microtubule.

Design, synthesis, biological evaluation and cocrystal structures with tubulin of chiral ß-lactam bridged combretastatin A-4 analogues as potent antitumor agents.

A diverse of chiral ß-lactam bridged analogues of combretastatin A-4 (CA-4), 3-substituted 1,4-diaryl-2-azetidinones, were asymmetrically synthesized and biologically evaluated, leading to identify a number of potent anti-proliferative compounds represented by 14b and 14c with IC50 values of 0.001-0.021 µM, against four human cancer cell lines (A2780, Hela, SKOV-3 and MDA-MB-231). Structure-activity relationship (SAR) studies on all stereoisomers of 14b and 14c revealed that the absolute configurations of the chiral centers at 3- and 4-position were critically important for the activity and generally a trans configuration between the "A" and "B" rings is optimal. In addition, 14b and 14c displayed less cytotoxicity on normal human oviduct epithelial cells than malignant cells indicating good selectivity in vitro. Further biochemical evaluation and cocrystal structures with tubulin demonstrated that both compounds disrupted tubulin polymerization through interacting at the colchicine-binding site, suppressed angiogenesis in vitro and in vivo, blocked cell cycle progression at mitotic phase and induced cellular apoptosis. The in vivo assays verified that both compounds inhibited xenograft tumor growth in nude mice with acceptable therapeutic window, showing promising potentials for further clinical development.

Design, synthesis, and biological evaluation of hydantoin bridged analogues of combretastatin A-4 as potential anticancer agents.

A series of novel hydantoin-bridged analogues of combretastatin A-4 (CA-4) were designed, synthesized and evaluated for antiproliferative activities in vitro and in vivo. The most potent compound 8d, showed potent cytotoxicity against four human cancer cell lines with IC50 values of 0.186-0.279 µM, and possessed the efficacy of inhibiting tubulin polymerization, disrupting in vitro vascularization, blocking cell cycle in G2/M phase and inducing cell apoptosis. In the nude mice xenograft model, 8d significantly inhibited the tumor growth and showed low toxicity. Further chiral separation proved (R)-(-)-8d to be the preferential enantiomer with IC50 values of 0.081-0.157 M. These results indicated that the hydantoin derivatives merit further investigation as potential anticancer agents that inhibit tubulin polymerization.

Potent Antitumor Activities and Structure Basis of the Chiral ß-Lactam Bridged Analogue of Combretastatin A-4 Binding to Tubulin.

A series of chiral ß-lactam bridged analogues (3-substituted 1,4-diaryl-2-azetidinones) of combretastatin A-4 (CA-4) were synthesized asymmetrically, and their antitumor activities were evaluated in vitro and in vivo. The cocrystal structure of tubulin in complex with compound 9 was determined by X-ray crystallography, which showed that 9 binds to the same site as colchicine with similar binding mode, and the absolute configuration of its C-4 was first identified and demonstrated to be critically important for their antiproliferative activities.