Design, Synthesis and Antitumor Activity of Novel Selenium-Containing Tepotinib Derivatives as Dual Inhibitors of c-Met and TrxR.

Cellular mesenchymal-epithelial transition factor (c-Met), an oncogenic transmembrane receptor tyrosine kinase (RTK), plays an essential role in cell proliferation during embryo development and liver regeneration. Thioredoxin reductase (TrxR) is overexpressed and constitutively active in most tumors closely related to cancer recurrence. Multi-target-directed ligands (MTDLs) strategy provides a logical approach to drug combinations and would adequately address the pathological complexity of cancer. In this work, we designed and synthesized a series of selenium-containing tepotinib derivatives by means of selenium-based bioisosteric modifications and evaluated their antiproliferative activity. Most of these selenium-containing hybrids exhibited potent dual inhibitory activity toward c-Met and TrxR. Among them, compound 8b was the most active, with an IC50 value of 10 nM against MHCC97H cells. Studies on the mechanism of action revealed that compound 8b triggered cell cycle arrest at the G1 phase and caused ROS accumulations by targeting TrxR, and these effects eventually led to cell apoptosis. These findings strongly suggest that compound 8b serves as a dual inhibitor of c-Met and TrxR, warranting further exploitation for cancer therapy.

Identification of acetylshikonin as a novel tubulin polymerization inhibitor with antitumor activity in human hepatocellular carcinoma cells.

Background: Microtubules are attractive targets for anticancer drugs. However, the microtubule-targeting agents (MTAs) currently in clinical use exhibit inevitable drug resistance. Therefore, there is an urgent need to discover novel MTAs for the clinical treatment of cancer. Methods: Bioactive compounds extracted from Lithospermum erythrorhizon were assessed for in vitro anti-proliferative activities against a panel of human cancer cell lines using cell counting kit-8 (CCK-8) assay. Tubulin polymerization inhibition assay, colchicine competitive binding site assay, and immunofluorescence were used to validate the tubulin inhibition effect of acetylshikonin. Flow cytometry, Hoechst staining, and caspase-3 activity evaluation were performed to assess cell cycle arrest and cell apoptosis. 5,5',6,6'-tetrachloro-1,1',3,3'-tetramethylbenzimidazolylcarbocyanine iodide (JC-1) staining and dichloro-dihydro-fluorescein diacetate (DCFH-DA) staining were used to evaluate mitochondrial membrane potential (MMP) and reactive oxygen species (ROS), respectively. Results: Acetylshikonin exhibited potent anti-proliferative activities against a panel of human cancer cell lines (IC50 values: 1.09-7.26 µM) and displayed comparable cytotoxicity against several drug-resistant cell lines. Further mechanism studies revealed that acetylshikonin induced cell cycle arrest of MHCC-97H cells at G2/M phase, and significantly promoted apoptosis marked by a collapse of MMP and abnormal ROS accumulation. Conclusions: In this study, acetylshikonin was identified as MTA against hepatocellular carcinoma and can serve as a promising lead compound for further development of anti-cancer drug, underscoring its potential clinical significance.

Discovery of a Novel Stilbene Derivative as a Microtubule Targeting Agent Capable of Inducing Cell Ferroptosis.

Microtubule targeting agents (MTAs) are used as clinically effective chemotherapies for cancer treatment but might be limited by the acquired or intrinsic resistance of cancer cells to apoptosis. The vulnerability of therapy-resistant cancers to ferroptosis provides an alternative way to overcome drug resistance. In this study, on the basis of the MTAs obtained in our previous studies, a series of MTAs were synthesized, and detailed structure-activity relationships were obtained through extensive molecular dynamics studies. Among them, a diphenylethene derivative, compound 33, displayed the most potent activity in vitro and in vivo, with IC50 values of 10-50 nM toward six cancer cell lines and a 78.6% tumor growth inhibition in vivo. Interestingly, although it acted as the MTA, compound 33 triggered cell death mainly through cell ferroptosis rather than apoptosis, which might provide an alternative way to eradicate apoptosis-related drug resistance.

The discovery of a potent and selective third-generation EGFR kinase inhibitor as a therapy for EGFR L858R/T790M double mutant non-small cell lung cancer.

A new series of AZD9291 (osimertinib) derivatives containing a sulfoxide side chain at the C-4 position of an aniline moiety were designed, synthesized and evaluated. Among these derivatives, the chiral sulfoxide derivative (-)-4i exhibited excellent inhibition of EGFR kinase activity and L858R/T790M double mutant cell proliferation, with IC50 values of 4.10 nM and 10 nM, respectively. A mechanism study elucidated that (-)-4i induced cell apoptosis and reduced phosphorylation of EGFR and AKT in a dose-dependent manner. Furthermore, (-)-4i exhibited very little apparent toxicity toward three non-tumorigenic cell lines and was less toxic than AZD9291. Moreover, the remarkable exposure (AUC0-inf: 1294.74 h ng/mL), oral bioavailability (73.69%), and relatively shorter half-life (t1/2 = 1.12 h) of (-)-4i displayed its favorable pharmacokinetic properties. Finally, the antitumor activity of (-)-4i in vivo resulted in a significant reduction of the tumor volume (TGI: 94.30%). Altogether, these results suggest that (-)-4i warrants further investigation in Non-Small cell lung cancer (NSCLC) therapy.

Design, synthesis, and biological evaluation of novel benzodiazepine derivatives as anticancer agents through inhibition of tubulin polymerization in vitro and in vivo.

A series of novel structurally-related tubulin polymerization inhibitors based on benzodiazepine were designed, synthesized, and evaluated for anticancer activity. Extensive structure modifications were performed to investigate the detailed structure and activity relationships (SARs). Most compounds exhibited potent antiproliferative activity against a panel of cancer cell lines. Among these compounds, the optimal compound, 9a, possessed the most superior activity, including cytotoxicity against five cancer cell lines (IC50 = 6-15 nM) and inhibition of tubulin polymerization (IC50 = 1.65 ±â€¯0.11 µM). Mechanistic studies revealed that 9a could disrupt intracellular microtubule organization, arrest cell cycle at the G2/M phase and eventually induce cell apoptosis. Compound 9a exhibited good metabolic stability with a t1/2 of 161.2 min, which was much better than the reference compound CA-4. Moreover, the disodium salt of 9a, 9a-P, exhibited excellent in vivo antitumor activity in xenograft mice model with inhibitory rate of 89.3%, which was better than the reference compounds CA-4P (inhibitory rate: 52.8%) and Y-01P (inhibitory rate: 77.7%). Altogether, 9a could serve as a promising lead compound for the development of highly efficient anticancer agents.

Design, Synthesis, and Biological Evaluation of Novel Selenium-Containing Isocombretastatins and Phenstatins as Antitumor Agents.

Two series of structurally related organoselenium compounds designed by fusing the anticancer agent methyl(phenyl)selane into the tubulin polymerization inhibitors isocombretastatins or phenstatins were synthesized and evaluated for antiproliferative activity. Most of these selenium containing hybrids exhibited potent cytotoxicity against a panel of cancel cell lines, with IC50 values in the submicromolar concentration range. Among them, 11a, the 3-methylseleno derivative of isocombretastatin A-4 (isoCA-4) represented the most active compound with IC50 values of 2-34 nM against 12 cancer cell lines, including two drug-resistant cell lines. Importantly, its phosphate salt, 11ab, inhibited tumor growth in xenograft mice models with inhibitory rate of 72.9% without apparent toxicity, which was better than the reference compounds isoCA-4P (inhibitory rate 52.2%) and CA-4P (inhibitory rate 47.6%). Mechanistic studies revealed that 11a is a potent tubulin polymerization inhibitor, which could arrest cell cycle at G2/M phase and induce apoptosis along with the decrease of mitochondrial membrane potential. In summary, 11a could serve as a promising lead for the development of highly efficient anticancer agents.

The synthesis and evaluation of new butadiene derivatives as tubulin polymerization inhibitors.

A series of new butadiene derivatives was synthesized and evaluated as tubulin polymerization inhibitors for the treatment of cancer. The optimal butadiene derivative, 9a, exhibited IC50 values of 0.056-0.089µM for five human cancer cell lines. This paper included a mechanistic study of the antiproliferative activity, including a tubulin polymerization assay, an examination of morphological alterations of cancer cells, an analysis of cell cycle arrest and an apoptosis assay.

A novel synthetic compound exerts effective anti-tumour activity in vivo via the inhibition of tubulin polymerisation in A549 cells.

Microtubules are critical elements that are involved in a wide range of cellular processes, and thus, they have become an attractive target for many anticancer drugs. A novel synthesised compound, 12P, was identified as new microtubule inhibitor. This compound inhibits tubulin polymerisation through binding to the colchicine-binding site of tubulin. 12P exhibits excellent anti-proliferative activities against a panel of human cancer cell lines, with IC50 values range from 9 to 55nM. Interestingly, compound 12P also displayed equally potent cytotoxicity against several drug-resistant cell lines, and it showed high selectivity for active human umbilical vein endothelial cells (HUVECs). Further flow cytometric analysis showed that 12P induces G2/M phase arrest and apoptosis in A549 cells. Cellular studies have revealed that the induction of apoptosis by 12P was associated with a collapse of mitochondrial membrane potential (MMP), accumulation of reactive oxygen species (ROS), alterations in the expression of some cell cycle-related proteins (e.g. Cyclin B1, Cdc25c, Cdc2) and some apoptosis-related proteins (e.g. Bax, Bad, Bcl-2, Bcl-xl). Importantly, 12P significantly reduced the growth of xenograft tumours of A549 cells in vivo (tumour inhibitory rate of 12P: 84.2%), without any loss of body weight. Taken together, these in vitro and in vivo results suggested that 12P may become a promising lead compound for the development of new anticancer drugs.