A recent antitumor story of podophyllotoxin derivatives targeting tubulin: an update (2017-2022)

So far, numerous tubulin-targeted podophyllotoxin congeners were designed and synthesized to overcome the poor water-solubility and improve the pharmaceutical characteristics. However, few studies are dedicated to exploring the interaction of tubulin with the downstream signal transduction pathways, which is important for gaining insight into the role of tubulin in the anticancer action of podophyllotoxin-based conjugates. In this review, we described a detailed account of all the advances on tubulin targeting-podophyllotoxin derivatives from 2017 and 2022 with in depth knowledge about their antitumor action and potential molecular signaling pathways directly involved in tubulin depolymerization, aiming to help researchers design and develop better anticancer drugs derived from podophyllotoxin. Moreover, we also discussed the associated challenges and future opportunities in this field. Short teaser Recent reviews summarized podophyllotoxin-based analogues, with interaction between tubulin and signal pathways being rarely involved. This review comprehensively sum up how podophyllotoxin derivatives targeting tubulin exert their antitumor action via potential molecular signaling pathways.

Cytotoxicity and mechanism of action of metal complexes: An overview

After the discovery of cisplatin, many metal compounds were investigated for the therapy of diseases, especially cancer. The high therapeutic potential of metal-based compounds is related to the special properties of these compounds, such as their redox activity and ability to target vital biological sites. The overproduction of ROS and the consequent destruction of the membrane potential of mitochondria and/or the DNA helix is one of the known pathways leading to the induction of apoptosis by metal complexes. The apoptosis process can occur via the death receptor pathway and/or the mitochondrial pathway. The expression of Bcl2 proteins and the caspase family play critical roles in these pathways. In addition to apoptosis, autophagy is another process that regulates the suppression or promotion of various cancers through a dual action. On the other hand, the ability to interact with DNA is an important property found in several metal complexes with potent antiproliferative effects against cancer cells. These interactions were classified into two important categories: covalent/coordinated or subtle, and non-coordinated interactions. The anticancer activity of metal complexes is sometimes achieved by the simultaneous combination of several mechanisms. In this review, the anticancer effect of metal complexes is mechanistically discussed by different pathways, and some effective agents on their antiproliferative properties are explained.

Inspired by bis-β-carboline alkaloids: Construction and antitumor evaluation of a novel bis-β-carboline scaffold as potent antitumor agents

Bis-β-carboline alkaloids are widely distributed in natural products and represent a promising drug-like scaffold for discovering drugs and bioactive molecules. In this study, we utilized the structural simplification strategy to construct a novel bis-β-carboline scaffold via "one-pot" condensation-Mannich reaction. The simplified bis-β-carboline derivatives were obtained in good yield. Antitumor evaluation revealed most compounds, especially 3m, displayed potent antitumor activity (IC₅₀ values for 3m: 0.96 μM ∼ 1.52 μM). More importantly, 3m displayed valuable antitumor properties including anti-migration and anti-invasion activity against cancer cells, antiangiogenic and vascular-disrupting properties. Mechanistic studies revealed 3m potently inhibited both Top1 and Top2 activity, thus interfering with DNA synthesis in cancer cells. Taken together, this study developed a new synthetic methodology to construct a novel bis-β-carboline scaffold, which represents a promising lead structure for antitumor drug discovery.

Preparation of PEGylated nedaplatin liposomes with sustained release behavior for enhancing the antitumor efficacy of non-small cell lung cancer

Nedaplatin (NDP) plays an important role in the chemotherapies of non-small cell lung cancer (NSCLC). However, dose-limiting toxicities such as myelosuppression and drug resistance restrict its clinical application. Herein, we intended to overcome these defects by developing a PEGylated liposomal formulation encapsulated NDP (NDP-LPs). For the first time, we found the incompatibility between NDP and natural phospholipids such as egg phosphatidylcholine (EPC) using the high-performance liquid chromatography (HPLC) method. The orthogonal experimental design was applied to optimize the conditions for preparing NDP-LPs, with encapsulation efficiency (EE) as the evaluation indicator. The physicochemical properties of optimized NDP-LPs were further characterized, including particle size, zeta potential, EE, drug release profiles, and so on. Results showed that a significantly sustained-release profile of NDP-LPs was observed and the releasing time of NDP could reach as long as 8 days. At the cellular level, NDP encapsulated in the PEGylated liposomes enhanced its cellular uptake and possessed potent cytotoxic activity. After intravenous injection, NDP-LPs could accumulate at tumor sites and effectivelyinhibit tumor growth of mice without obvious adverse effects. In conclusion, our results demonstrated that PEGylated liposomes could serve as a promising carrier to enhance the therapeutic effects of NDP.

Redox-responsive paclitaxel-pentadecanoic acid conjugate encapsulated human serum albumin nanoparticles for cancer therapy

Human serum albumin (HSA) is an important nanocarrier of hydrophobic drugs due to its biocompatibility, bioresorbability, non-immunogenicity and intrinsic targetability. However, HSA/drug nanocomplexes have to experience complicated manufacturing process including multiple high-pressure homogenization and removing organic solvent under reduced pressure condition. Besides, the clinical application of these HSA/drug nanocomplexes is often limited because of their unsatisfactory stability and restricted dose. To overcome these issues, a redox-responsive paclitaxel-pentadecanoic acid prodrug conjugate embedded human serum albumin nanoparticles (NPs) was developed as a model in this report. First, PTX was activated and conjugated with 11-mercaptoundecanoic acid through a disulfide bond. The resultant disulfide bond bridged paclitaxel-pentadecanoic acid conjugate (PTX-SS-C10-COOH) was characterized by NMR and MS. After that, PTX-SS-C10-COOH dissolved in ethanol was mixed with HSA in water followed by lyophilization to generate HSA/PTX-SS-C10-COOH nanoparticles (HPTX NPs). Dynamic light scattering (DLS) and transmission electron microscopy (TEM) characterization indicated that the HPTX NPs have spherical structure with an average diameter of approximately 120 nm. The formation of HSA/PTX-SS-C10-COOH NPs was confirmed by fluorescence quenching technology, ascribed to electrostatic and hydrophobic interactions. The HPTX NPs displayed a highdrug loading of 29.78 % and an entrapment efficiency of 94.16 %. Their reduced responsiveness was validated by glutathione (GSH)-triggered fast release of PTX. The pharmacokinetics, antitumor efficacy and systemic toxicity of HPTX NPs were thoroughly evaluated. The results showed that the HPTX NPs had longer retention, more effective tumor growth inhibition and lower toxicity compared with commercialized Taxol®. Importantly, the HPTX NPs could be administered at much high dose to achieve a significant tumor growth inhibition compared with Abraxane®. Together, the redox-responsive HPTX NPs with high drug loading is a promising strategy to deliver PTX for cancer chemotherapy.

Monoterpenoid derivatives from Hyssopus cuspidatus Boriss. and their bioactivities

Six undescribed monoterpenoids, together with twelve known compounds were isolated and identified from Hyssopus cuspidatus Boriss. Their structures were established by spectroscopic analysis, and the absolute configurations were established by ECD calculations and single-crystal X-ray diffraction crystallography. The isolated compounds were tested for their anti-inflammatory, antibacterial and antitumor activities. Most of the compounds showed potent anti-inflammatory activities. Among them, 3β-hydroxy-7,8-dihydro-β-ionone (8), oleanolic acid (17) and acetylpleamolic acid (18) showed strong anti-inflammatory activity against IL-6 and TNF-α in lipopolysaccharide (LPS) stimulated RAW 264.7 cells. Several compounds showed moderate inhibitory activities against Staphylococcus aureus, Candida albicans, and Escherichia coli. And (4S)-p-menth-l-ene-7,8-diol 8-O-β-D-glucopyranoside (16) showed antitumor activities against MCF-8 and HT-29 cell lines with IC₅₀ values of 93.39 ± 3.69 and 71.89 ± 2.94 μM, respectively. Oleanolic acid (17) showed moderate antitumor activity against HT-29 cell lines with an IC₅₀ value of 52.62 ± 1.63 μM. In this study, the discovery of anti-inflammatory, antibacterial and antitumor components from H. cuspidatus could benefit further development and utilization of this plant.

Pan-HDAC inhibitors augment IL2-induced proliferation of NK cells via the JAK2-STAT5B signaling pathway

BACKGROUND

Natural killer (NK) cells are a subtype of lymphocytes with the ability to quickly and efficiently identify and eliminate tumor cells. In the presence of IL2, NK cells can divide rapidly but in limited numbers. According to previous studies, in vivo treatment with histone deacetylase (HDAC) inhibitors did not impair NK-cell function. This study aimed to investigate the effect of HDAC inhibitors on NK-cell proliferation and the underlying regulatory mechanism.

METHODS

NK92 cells, primary NK (pNK) cells, and CD19-CAR-NK92 cells were treated with low concentrations of pan-HDACi Dacinostat (Dac) and Panobinostat (Pan) in the presence of IL2, and Cell Counting Kit-8 (CCK8), 5-ethynyl-2'-deoxyuridine (EdU), and flow cytometry assays were used to assess cell proliferation and apoptosis. The expression of granzyme B was detected by immunofluorescence, and the expression of CD107a and NKG2D was determined by flow cytometry. The downstream regulatory genes were identified by RNA-seq, and the "JAK-STAT signaling pathway"- and "Cell cycle signaling pathway"-related genes were detected by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis. The JAK2^V617F mouse model was constructed to simulate the upregulation of the JAK2 signaling pathway in vivo, and the NK proliferation was evaluated by flow cytometry. A tumor-bearing nude mouse model was constructed to determine the anti-tumor efficacy of NK92 cells following Dac treatment.

RESULTS

In the presence of IL2, the proliferation rate of NK92 cells, pNK cells, and CD19-CAR-NK92 cells treated with pan-HDACi Dac and Pan at low nanomolar doses was significantly increased, although cell function was unaffected. Low doses of Dac upregulated the JAK-STAT signaling pathway and enhance the cell cycle via that pathway. In addition, the in vivo experiment in nude mice showed that the capacity of Dac treated NK92 cells to eliminate tumor cells was unaffected.

CONCLUSION

Low nanomolar doses of Pan-HDACi enhanced IL2-induced NK cell proliferation without compromising the functioning of NK cells.

Antitumor activity of synthetic three copper(II) complexes with terpyridine ligands

Three new synthetic terpyridine copper(II) complexes were characterized. The copper(II) complexes induced apoptosis of three cancer cell lines and arrested T-24 cell cycle in G1 phase. The complexes were accumulated in mitochondria of T-24 cells and caused significant reduction of the mitochondrial membrane potential. The complexes increased both intracellular ROS and Ca²⁺ levels and activated the caspase-3/9 expression. The apoptosis was further confirmed by Western Blotting analysis. Bcl-2 was down-regulated and Bax was upregulated after treatment with complexes 1-3. The in vivo studies showed that complexes 1-3 obviously inhibited the growth of tumor without significant toxicity to other organs.

Cytotoxicity and Antitumor Activity of Arglabin and its Derivatives

BACKGROUND

At present, more than 8000 sesquiterpene lactones have been isolated and described from natural sources, a significant part of which has cytotoxicity and antitumor activity. One of the practically available sesquiterpene lactones is arglabin, which, as a renewable material, is used for the synthesis of new compounds. The article presents data on the study of cytotoxicity and antitumor activity of the arglabin and its derivatives using molecular modeling methods and, in the experiment in vitro and in vivo.

AIM

The aim of this work is to study the cytotoxicity and antitumor activity of new compounds based on the sesquiterpene lactone arglabin using molecular modeling and experimental pharmacology.

METHODS

ChemDraw programs and a set of AutoDock programs were used for computer simulation. Molecular docking was carried out using the Maestro graphical interface of the Schrödinger Suite software package (Schrödinger, LLC, New York, NY, 2017). Docking modes standard precision and XP (extra precision) were used. In in vitro experiments, the antitumor activity of compound samples was studied in models of 60 human tumor cell lines, and clonogenic C6 rat glioma cells. The antitumor activity of the samples was studied in experiments in vivo on white outbred rats with transplanted tumors and was evaluated by the inhibition of tumor growth and the magnitude of the increase in average life expectancy.

CONCLUSION

When studying the antitumor activity on 60 cell lines of tumor cells (NCI60), clonogenic cells of C6 rat glioma, a high antitumor activity of some arglabin derivatives was established. The connection between the structure of arglabin derivatives and their inhibitory effect on farnesyl protein transferase, topoisomerases -I and -II was studied.

Function-oriented synthesis of Imidazo[1,2-a]pyrazine and Imidazo[1,2-b]pyridazine derivatives as potent PI3K/mTOR dual inhibitors

The PI3K-Akt-mTOR signaling pathway is a highly frequently activated signal transduction pathway in human malignancies, which has been a hot target for anti-tumoral drug discovery. Based on our previous research, a function-oriented synthesis (FOS) of imidazo[1,2-a]pyrazines and imidazo[1,2-b]pyridazines was conducted, and their anticancer activities in vitro and in vivo were evaluated. Among them, compound 42 exhibited excellent dual PI3K/mTOR inhibitory activity, with IC50 values on PI3Kα and mTOR of 0.06 nM and 3.12 nM, respectively, much better than our previous reported compound 15a. Furthermore, compound 42 exhibited significant in vitro and in vivo anti-tumoral activities, great kinase selectivity, low hepatotoxicity, modest plasma clearance and acceptable oral bioavailability, which is a promising PI3K/mTOR targeted anti-cancer drug candidate.

Discovery of two biotin-PEG4‑diarylidenyl piperidone prodrugs as potent antitumor agents with good efficacy, limited toxicity, and low resistance

Two biotin-polyethylene glycol (PEG)4‑diarylidenyl piperidone (DAP) prodrugs, compounds 3a and 3b, were designed as antineoplastic agents and synthesized by coupling biotin to bifluoro- and binitro-substituted DAP derivatives (DAP-F and DAP-NO₂) through a PEG4 linker, respectively. The results of the MTT (3-(4, 5)-dimethylthiahiazo (-z-y1)-3, 5-di- phenytetrazoliumromide) assay and a SW480 xenograft model identified compounds 3a and 3b as candidate antitumor agents with good efficacy, limited toxicity, and low resistance, as compared to the original drugs (DAP-F and DAP-NO₂), cisplatin, and doxorubicin (dox). The results of a preliminary pharmacokinetic study showed that compounds 3a and 3b slowly released their original drug DAP-F and DAP-NO₂ within 12 h after intraperitoneal injection, respectively. Western blot analysis and computer docking simulations indicated that DAP-F, DAP-NO₂, and compounds 3a and 3b were indeed inhibitors of signal transducer and activator of transcription 3 (STAT3) and the antitumor effects of compounds 3a and 3b were exerted by sequentially interacting with the SH2-binding domain followed by the DNA-binding domain after releasing the original drugs DAP-F and DAP-NO₂, respectively. These results suggest that the targeted prodrug model led to good antitumor efficacy with reduced toxicity, while a dual STAT3-binding model may promote antitumor efficacy and resistance.

Synthesis and biological evaluation of novel SN38-glucose conjugate for colorectal cancer treatment

7-Ethyl-10-hydroxycamptothecin (SN38), the bioactive metabolite of irinotecan (CPT-11), has been shown to be 100-1000 times more effective than CPT-11. However, the poor water solubility and bioavailability of SN38 constrained its clinical application. In this study, we synthesized a novel SN38-glucose conjugate (FSY04) to address this issue. Our in vitro studies indicated that FSY04 had a potent inhibitory ability against colorectal cancer (CRC) cell lines of SW-480 and HCT-116 compared to the inhibitory capacity of CPT-11. Interestingly, FSY04 possessed lower cytotoxicity against normal cell lines of LO2 and 293T in contrast with CPT-11. Moreover, FSY04 is more active than CPT-11 in inducing apoptosis, inhibiting migration, and invasion. In vivo experiments suggested that half of the equivalent of FSY04 inhibited the growth of SW480 in the xenograft tumor model better than one equivalent of CPT-11. Our data demonstrated FSY04 to be a promising agent in CRC therapy.

Straightforward synthesis of steroidal selenocyanates through oxidative umpolung selenocyanation of steroids and their antitumor activity

Straightforward access to steroidal selenocyanates in a single assembly step from steroids remains a significant challenge. However, the development of novel method for the synthesis of steroidal selenocyanates and further investigation of their bioactivities have largely lagged behind. In this work, selenocyano groups were directly introduced into the 17- or 21-position of pregnenolone, the 2-position of estradiol, and the 16-position of estrone. A total of 16 estrogen selenocyanate derivatives with diverse structures were synthesized, and the tumor cell lines closely related to the expression level of estrogen were used to investigate the inhibitory activity of the target products on tumor cell proliferation in vitro. The results revealed that the 17-selenocyano-substituted pregnenolone selenocyanate derivatives 1b-3b exhibit obvious inhibitory activity against the tested tumor cell lines. Additionally, the 2-selenocyano-substituted estradiol derivatives and 16-selenocyano-substituted estrone derivatives exhibit selective inhibitory on HeLa cell lines. Among them, 2-selenocyano-3-methoxyestradiol-17-benzoate (7e) displayed an IC₅₀ value of 4.1 µM against HeLa cells and induced programmed apoptosis in HeLa cancer cells. Furthermore, compound 7e could significantly inhibit the growth of human cervical cancer xenografts in zebrafish in vivo. This approach provides new insights for future steroid antitumor drug design.

An oral WT1 protein vaccine composed of WT1-anchored, genetically engineered Bifidobacterium longum allows for intestinal immunity in mice with acute myeloid leukemia

Wilms' tumor 1 (WT1) is a promising tumor-associated antigen for cancer immunotherapy. We developed an oral protein vaccine platform composed of WT1-anchored, genetically engineered Bifidobacterium longum (B. longum) and conducted an in vivo study in mice to examine its anticancer activity. Mice were orally treated with phosphate-buffered saline, wild-type B. longum105-A, B. longum 2012 displaying only galacto-N-biose/lacto-N-biose I-binding protein (GLBP), and WT1 protein- and GLBP-expressing B. longum 420. Tumor size reduced significantly in the B. longum 420 group than in the B. longum 105-A and 2012 groups (P < 0.00 l each), indicating B. longum 420's antitumor activity via WT1-specific immune responses. CD8⁺ T cells played a major role in the antitumor activity of B. longum 420. The proportion of CD103⁺CD11b⁺CD11c⁺ dendritic cells (DCs) increased in the Peyer's patches (PPs) from mice in the B. longum 420 group, indicating the definite activation of DCs. In the PPs, the number and proportion of CD8⁺ T cells capable of producing interferon-gamma were significantly greater in the B. longum 420 group than in the B. longum 2012 group (P < 0.05 or < 0.01). The production of WT1-specific IgG antibody was significantly higher in the B. longum 420 group than in the 2012 group (P < 0.05). The B. longum 420 group showed the most intense intratumoral infiltration of CD4⁺ and CD8⁺ T cells primed by activated DCs in the PPs of mice in the B. longum 420 group. Our findings provide insights into a novel, intestinal bacterium-based, cancer immunotherapy through intestinal immunity.

Anti-tumoral Titanium(IV) Complexes Stabilized with Phenolato Ligands and Structure-Activity Relationship

Titanocene dichloride and budotitane have opened a new chapter in medicinal chemistry of titanium(IV) complexes being novel non-platinum antitumor metallic agents. Numerous efforts have led to the discovery of the diamino bis-phenolato titanium(IV) complexes. Among which, the [ONNO] and [ONON] type ligands namely Salan, Salen and Salalen coordinated titanium(IV) alkoxyl complexes have demonstrated significantly enhanced aqueous stability, their in vitro and in vivo antitumor efficacy, mechanism of action, structure-activity relationships and combined tumor therapy have been intensively investigated. Replacement of the labile alkoxyls with a second chelator resulted in structural rigid titanium(IV) complexes, which showed exceedingly good aqueous stability and potent antitumor activity both in vitro and in vivo. The unique ligand system successfully allowed the access of isotopic [45Ti]Titanium(IV) complexes, post-synthetic modification, facile synthetic protocols and antitumor congeneric zirconium(IV) and hafnium(IV) complexes. This review presents recent research progress in the field of antitumor group 4 metal complexes stabilized with phenolato ligands; especially their structure-activity relationships are summarized.

Design, Synthesis, anticancer evaluation and in silico studies of 2,4,6-trimethoxychalcone derivatives

Chalcone, a common chemical scaffold of many naturally occurring compounds, has been widely used as an effective template for drug discovery due to its broad biological activities. In this study, a series of chalcone derivatives were designed and synthesized based on the hybridization of 1-(2,4,6-trimethoxyphenyl)butan-1-one with chalcone. Interestingly, most of the target compounds exhibited inhibitory effect of tumor cells in vitro. Especially, (E)-3-(5-bromopyridin-2-yl)-1-(2,4,6-trimethoxyphenyl)prop-2-en-1-one (B3) revealed over 10-fold potency than 5-fluorocrail against the Hela and MCF-7 cells with IC₅₀ values of 3.204 and 3.849 μM respectively. Moreover, B3 displayed low toxicity on normal cells. Further experiments indicated that B3 effectively inhibited the proliferation and migration of tumor cells, and promoted their apoptosis. The calculation and prediction of ADME showed that the target compounds may have good pharmacokinetic properties and oral bioavailability. Reverse molecular docking suggested that the possible target of B3 is CDK1. Taken together, these results suggested that B3 appears to be a promising candidate that merits further attention in the development of anticancer drugs.

Synthesis, characterization and in vitro cytotoxicity of ruthenium(II) metronidazole complexes: Cell cycle arrest at G1/S transition and apoptosis induction in MCF-7 cells

Ruthenium compounds are known to be potential drug candidates since they offer the potential for reduced toxicity. Furthermore, the various oxidation states, different mechanisms of action and ligand substitution kinetics give them advantages over platinum-based complexes, making them suitable for use in biological applications. So, herein, novel ruthenium(II) complexes with metronidazole as ligand were obtained [RuCl(MTNZ)(dppb)(4,4'-Mebipy)]PF₆ (1), [RuCl(MTNZ)(dppb)(4,4'-Methoxybipy)]PF₆ (2), [RuCl(MTNZ)(dppb)(bipy)]PF₆ (3) and [RuCl(MTNZ)(dppb)(phen)]PF₆ (4) where, MTNZ = metronidazole, dppb = 1,4-bis(diphenylphosphino)butane, 4,4'-Mebipy = 4,4'-dimethyl-2,2'-bipyridine, 4,4'-Methoxybipy = 4,4'-dimethoxy-2,2'-bipyridine, bipy = 2,2'-bipyridine and phen = 1,10-phenanthroline. The complexes were characterized by elemental analysis, molar conductivity, infrared and UV-Vis spectroscopy, cyclic voltammetry, ³¹P{¹H}, ¹H, ¹³C{¹H} and Dept 135 NMR and mass spectrometry. The interaction of complexes 1-4 with DNA was evaluated, and their cytotoxicity profiles were determined on four different tumor cell lines derived from human cancers (SK-MEL-147, melanoma; HepG2, hepatocarcinoma; MCF-7, estrogen-positive breast cancer; A549, non-small cell lung cancer). We demonstrated that complexes (1) and (3) are promising antitumor agents once inhibited the proliferative behavior of MCF-7 cells and induced apoptosis.

A water-soluble polysaccharide from Eucommia folium: the structural characterization and anti-tumor activity in vivo

In this study, a water-soluble polysaccharide from Eucommia folium was extracted by hot water and purified using Sephadex G-200 gel columns. The results showed that the purified fraction (EFP) has a molecular weight of 9.98 × 10⁵ Da and consisted of rhamnose, arabinose, galactose, glucose, mannose, xylose, galacturonic acid, and glucuronic acid (molar ratio: 0.226: 1.739: 2.183: 1: 0.155: 0.321: 0.358: 0.047). The combination of infrared spectroscopy and NMR analysis proved that EFP is an acidic polysaccharide whose main chain consists of α-L-Araf-(1 → , → 3,5)-α-Araf-(1 → , → 3)-β-Galp-(1 → , → 3,6)-β-Glcp-(1 → , → 2)-α-D-Manp-(1 → , → 4)-α-GalpA-(1 → , → 2,4)-α-Rhap-(1 → . In addition, the in vivo antitumoral activity of EFP was studied using a H22 tumor-bearing mice model. EFP effectively inhibited tumor growth in mice following intragastric administration. By Combining with the results of the apoptosis assay and JC-1 staining analysis, we confirmed that EFP induces apoptosis through the mitochondrial pathway. Furthermore, cell cycle analysis demonstrated that EFP blocks the cell cycle at S phase.

Preparation of triangular silver nanoparticles and their biological effects in the treatment of ovarian cancer

BACKGROUND

In recent years, silver nanoparticles (AgNPs) have gradually been widely used, especially in the field of anticancer medicine. Ovarian cancer (OC) is the gynaecological malignancy with the highest mortality rate, and the current treatment is still based on surgery, chemotherapy and postoperative targeted therapy. Therefore, the development of safe and effective nanoparticles for targeted therapy of OC is very important. This study aimed to prepare a new type of triangular silver nanoparticles (tAgNPs) and evaluate the anticancer properties for OC in vitro and in vivo.

METHODS

The tAgNPs were chemically synthesized and characterized using scanning electron microscopy (SEM), ultraviolet (UV) spectrophotometry and other techniques. By performing cell-based tests, such as cell counting kit-8 (CCK-8), plate colony formation, cell apoptosis, reactive oxygen species (ROS), and western blot (WB) assays, the inhibitory effects and related mechanisms of tAgNPs on OC cells were analysed.The anticancer effect of tAgNPs in vivo was verified by a SKOV3 tumor-bearing mouse model.

RESULTS

Five types of tAgNPs with different colours were successfully synthesized, with a particle size of 25-50 nm and a good dispersion. The results of in vitro experiments showed that tAgNPs treatment reduced the viability and proliferation of SKOV3 cells, arrested the cell cycle in G0/G1 phase, inhibited the expression levels of proliferation-related factors and cyclins, and promoted cell apoptosis by producing ROS and increasing caspase-3 activity. Consistent with the results of in vitro experiments, in vivo animal experiments also showed that tAgNPs significantly inhibited the proliferation of ovarian cancer. More importantly, no obvious toxic and side effects were observed.

CONCLUSIONS

In this study, a novel triangular AgNPs was successfully prepared. tAgNPs are very stable, significantly inhibit the proliferation of OC cells and tumour growth in tumour-bearing mice, providing a promising nanotargeted therapy for OC.

Study of biocompatibility, cytotoxic activity in vitro of a tetrazole-containing derivative of 2-amino-4,6-di(aziridin-1-yl)-1,3,5-triazine

The hydrolytic stability, hemocompatibility, antioxidant properties and in vitro cytotoxic activity of {5-[(4,6-di(aziridin-1-yl)-1,3,5-triazin-2-yl)amino]-2,2-dimethyl-1,3-dioxan-5-yl}methyl 2-(5-phenyl-2H-tetrazol-2-yl)acetate have been studied. ¹H NMR spectroscopy showed that this tetrazole-containing derivative of 1,3,5-triazine is stable in neutral (pH 7) and alkaline (pH 10) media; hydrolysis of the dioxane cycle occurs in an acidic environment (pH 3). It has been established that {5-[(4,6-di(aziridin-1-yl)-1,3,5-triazin-2-yl)amino]-2,2-dimethyl-1,3-dioxan-5-yl}methyl-2-(5-phenyl-2H-tetrazol-2-yl)acetate is hemocompatible, exhibits antioxidant properties, but does not show antiradical activity over the entire range of concentrations. In turn, the study of cytotoxic activity in vitro showed that the tetrazole-containing derivative of 1,3,5-triazine has an effect on the cell lines of human alveolar basal epithelium adenocarcinoma A549 (IC₅₀ 41.3 μmol l^-1), human ovarian teratocarcinoma PA-1 (IC₅₀ 10.6 μmol l^-1), hepatocarcinoma Huh7 (IC₅₀ 19.9 μmol l^-1), cervical cancer HeLa (IC₅₀ 3.7 μmol l^-1), and human embryonic kidney HEK293 (IC₅₀ 15.8 μmol l^-1). It was suggested one of the possible mechanism of substance 2 cytotoxicity via HIF pathway inhibition.

Fabrication of fucoxanthin/2-hydroxypropyl-β-cyclodextrin inclusion complex assisted by ultrasound procedure to enhance aqueous solubility, stability and antitumor effect of fucoxanthin

Fucoxanthin (Fx) possesses multiple bioactivities such as antitumor, antioxidant and anti-inflammatory activities, but its application is limited due to the poor water solubility, low bioavailability, and instability to some external harsh conditions. In this study, a stable inclusion complex of Fx and 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD) was prepared with the aid of ultrasound, which was characterized by scanning electron microscope, Fourier transform infrared spectroscopy, powder X-ray diffraction, and differential scanning calorimetry techniques. The phase solubility analysis and absorption spectroscopy results showed that Fx formed stoichiometry 1:2 inclusion complex with 2-HP-β-CD, and this could be well proved by molecular simulation. Structural analyses and molecular docking study indicated that Fx was successfully encapsulated into the cavity of 2-HP-β-CD, promoting it soluble in water and stable against heat, storage and gastrointestinal environments. In addition, Fx/2-HP-β-CD inclusion complex exhibited excellent antitumor activity against HCT116 and Caco-2 cell lines with IC₅₀ values of 12.0 μΜ and 14.86 μΜ, respectively. Therefore, it could be a potentially promising way to promote the application of Fx in pharmaceuticals and functional foods by HP-β-CD encapsulation strategy.

Synthesis and biological testing of 3,5-bis(arylidene)-4-piperidone conjugates with 2,5-dihydro-5H-1,2-oxaphospholenes

Using the methodology of "click" chemistry, a series of conjugates of 3,5-bis(benzylidene)-1-(prop-2-yn)piperidin-4-ones with 4-alkyl-3-azidomethyl-2-ethoxy-2,5-dihydro-5H-1,2 oxaphosphol 2-oxides was synthesized. All newly obtained compounds 8-18 were characterized by ¹H, ¹³C, ³¹P, ¹⁹F NMR and IR spectroscopy. The potential antitumor activity of the synthesized conjugates8-18was studied in terms of their ability to influence the viability of variouscancercell lines, including A549, SH-SY5Y, Hep-2, and HeLa. Compound 15, which contains two fluorine atoms in the benzene ring, was shown to be the most promising. The mechanism of the cytotoxic action of this conjugate is supposed to be associated with the ability to inhibit the glycolytic profile of transformed cells.

Design, synthesis, and antitumor study of a series of novel 1-Oxa-4-azaspironenone derivatives

A series of 1-oxa-4-azaspiro[4,5]deca-6,9-diene-3,8-dione derivatives containing structural fragments of conjugated dienone have been synthesized previously by our group, however the Michael addition reaction between conjugated dienone and nucleophilic groups in the body may generate harmful and adverse effects. To reduce harmful side effects, the authors started with p-aminophenol to make 1-oxo-4- azaspirodecanedione derivatives, then utilized the Michael addition and cyclopropanation to eliminate α, β unsaturated olefinic bond and lower the Michael reactivity of the compounds in vivo for optimization. At the same time, heteroatoms are put into the molecules in order to improve the hydrophilicity of the molecules and the binding sites of the molecules and the target molecules, establishing the groundwork for improved antitumor activity. The majority of the compounds had moderate to potent activity against A549 human lung cancer cells, MDA-MB-231 breast cancer cells, and Hela human cervical cancer cells. Among them, the compound 6d showed the strongest effect on A549 cell line with IC50 of 0.26 μM; the compound 8d showed the strongest cytotoxicity on MDA-MB-231 cell line with IC50 of 0.10 μM; and the compound 6b showed the strongest activity on Hela cell line with IC50 of 0.18 μM.

Synthesis and antitumor activity of a series of novel N-aryl-5-(2,2,2-trifluoroethoxy)-1,5-dihydro-2H-pyrrol-2-ones derivatives

With the help of the establishment of novel reaction methodology, a series of N-Aryl-5-(2,2,2-trifluoroethoxy)-1,5-dihydro-2H-pyrrol-2-one conjugates were designed and synthesized in 2-4 steps, and subsequent anticancer activity of these compounds was evaluated. Preliminary results showed that these compounds have moderate to potent activities against human acute leukemia cells K562, human lung cancer A549, human breast cancer MDA-MB-231, and human cervical cancer HeLa cancer cell lines. Among them, compounds 2d and 2k were the most potent against K562 cell line with IC₅₀ values of 0.07 and 0.52 µM, respectively, and the toxicity of 2d to the normal of hepatocytes (LO2) cell line was low (the survival rate 81 %). Flow cytometry analysis showed that 2d arrested K562 cells in the G2/M phase potently, even much better than Combretastatin A4 (CA4). In addition, the results demonstrated the involvement of the caspase-dependent or independent pathways of apoptosis, evidenced by the upregulation of FADD, pro-caspase 3, cleaved-caspase 3, HTRA2/Omi, SMAC/Diablo and the ratio of Bax/Bcl-2.The biological effects founding of 2d in this work point to prospective uses against acute leukemia.

Ten new prenylated flavonoids from Macaranga denticulata and their antitumor activities

Ten new prenylated flavonoids, named denticulains A-J (1-10), together with seven known prenylated flavonoids (11-17) were isolated from Macaranga denticulata. Their structures were elucidated on the basis of detailed spectroscopic analysis and by comparison with literature data. In addition, compounds 1 and 14 inhibited the proliferation of SW620 and HCT-116 cell lines with an IC₅₀ value of 46.08 μM and 56.83 μM, respectively.