A novel ALK inhibitor ZYY inhibits Karpas299 cell growth in vitro and in a mouse xenograft model and induces protective autophagy

Targeting HMGA1 contributes to immunotherapy in aggressive breast cancer while suppressing EMT

Metastasis is an obstacle to the clinical treatment of aggressive breast cancer (BC). Studies have shown that high mobility group A1 (HMGA1) is abnormally expressed in various cancers and mediates tumor proliferation and metastasis. Here, we provided more evidence that HMGA1 mediated epithelial to mesenchymal transition (EMT) through the Wnt/β-catenin pathway in aggressive BC. More importantly, HMGA1 knockdown enhanced antitumor immunity and improved the response to immune checkpoint blockade (ICB) therapy by upregulating programmed cell death ligand 1 (PD-L1) expression. Simultaneously, we revealed a novel mechanism by which HMGA1 and PD-L1 were regulated by the PD-L1/HMGA1/Wnt/β-catenin negative feedback loop in aggressive BC. Taken together, we believe that HMGA1 can serve as a target for the dual role of anti-metastasis and enhancing immunotherapeutic responses.

1-(4-((5-chloro-4-((2-(isopropylsulfonyl)phenyl)amino)pyrimidin-2-yl)amino)-3-methoxyphenyl)-3-(2-(dimethylamino)ethyl)imidazolidin-2-one (ZX-42) inhibits cell proliferation and induces apoptosis via inhibiting ALK and its downstream pathways in Karpas299 cells

Anaplastic lymphoma kinase (ALK) belongs to the family of receptor tyrosine kinases. Recently, the incidence of anaplastic large cell lymphoma (ALCL) with ALK rearrangement has raised considerably. The application of ALK-targeted inhibitors such as ceritinib provides an effective therapy for the treatment of ALK-positive cancers. However, with the prolongation of treatment time, the emergence of resistance is inevitable. We found that 1-(4-((5-chloro-4-((2-(isopropylsulfonyl)phenyl)amino)pyrimidin-2-yl)amino)-3-methoxyphenyl)-3-(2-(dimethylamino)ethyl)imidazolidin-2-one (ZX-42), a novel ceritinib derivative, could inhibit the proliferation of ALK-positive ALCL cells, induce the apoptosis of Karpas299 cells through the mitochondrial pathway in a caspase-dependent manner. In addition, ZX-42 could suppress ALK and downstream pathways including PI3K/Akt, Erk and JAK3/STAT3 and reduce the nuclear translocation of NFκB by inhibiting TRAF2/IKK/IκB pathway. Taken together, our findings indicate that ZX-42 shows more effective activity than ceritinib against ALK-positive ALCL. We hope this study can provide a direction for the structural modification of ceritinib and lay the foundation for the further development of clinical research in ALK-positive ALCL.

A novel tubulin inhibitor, 6h, suppresses tumor-associated angiogenesis and shows potent antitumor activity against non-small cell lung cancers

Tumor angiogenesis is closely associated with the metastasis and progression of non-small cell lung cancer (NSCLC), a highly vascularized solid tumor. However, novel therapeutics are lacking for the treatment of this cancer. Here, we developed a series of 2-aryl-4-(3,4,5-trimethoxy-benzoyl)-5-substituted-1,2,3-triazol analogs (6a-6x) as tubulin colchicine-binding site inhibitors, aiming to find a novel promising drug candidate for NSCLC treatment. We first identified 2-(2-fluorophenyl)-3-(3,4,5-trimethoxybenzoyl)-5-(3-hydroxyazetidin-1-yl)-2H-1,2,3-triazole (6h) as a hit compound, which inhibited angiogenesis induced by NSCLC cells both in vivo and in vitro. In addition, our data showed that 6h could tightly bind to the colchicine-binding site of tubulin and inhibit tubulin polymerization. We also found that 6h could effectively induce G2/M cell cycle arrest of A549 and H460 cells, inhibit cell proliferation, and induce apoptosis. Furthermore, we showed 6h had the potential to inhibit the migration and invasion of NSCLC cells, two basic characteristics of tumor metastasis. Finally, we found 6h could effectively inhibit tumor progression in A549 xenograft mouse models with minimal toxicity. Taken together, these findings provide strong evidence for the development of 6h as a promising microtubule colchicine-binding site inhibitor for NSCLC treatment.

Targeting Cysteine Located Outside the Active Site: An Effective Strategy for Covalent ALKi Design

Potent inhibitors of ALK are highly desired because of the occurrence of drug resistance. We herein firstly report the development of a rationally designed inhibitor, Con B-1, which can covalently bind to Cys1259, a cysteine located outside the ALK active site by linking a warhead with Ceritinib through a 2,2'-Oxybis(ethylamine) linker. The in vitro and in vivo assays showed ConB-1 is a potent selective ALKi with low toxicity to normal cells. In addition, the molecule showed significant improvement of anticancer activities and potential antidrug resistant activity compared with Ceritinib, demonstrating the covalent inhibitor of ALK can be a promising drug candidate for the treatment of NSCLC. This work may provide a novel perspective on the design of covalent inhibitors.

Discovery of a PROTAC targeting ALK with in vivo activity

Anaplastic lymphoma kinase (ALK) was involved in the development of various cancer types. Although several ALK inhibitors have been advanced to clinical trials, the emergence of drug resistance has limited the clinical application of them. To overcome the drug resistance, proteolysis targeting chimeras (PROTACs) could be an alternative strategy. In this study, a series of ALK degraders were designed and synthesized. The degraders were developed through the conjugation of LDK378 and CRBN E3 ubiquitin ligase ligands. Among all the molecules, compound B3 showed potent selective inhibitory activity to ALK and can decrease the cellular levels of ALK fusion proteins in a concentration- and time-dependent manner in H3122 cell line. Meanwhile, B3 showed improved anticancer activity in vitro comparing with LDK378 and the antiproliferative activity to xenograft tumor model was acceptable. All the results demonstrated that ALK degrader B3 with in vitro and in vivo anti-cancer activities was valuable for further investigation.

In vitro and in vivo synergistic efficacy of ceritinib combined with programmed cell death ligand-1 inhibitor in anaplastic lymphoma kinase-rearranged non-small-cell lung cancer

Both ceritinib (CER) and programmed cell death (PD)‐1/PD ligand‐1 (PD‐L1) have brought significant breakthroughs for anaplastic lymphoma kinase (ALK)‐rearranged non‐small‐cell lung cancer (NSCLC). However, the overall clinical efficacy of either CER or PD‐1/PD‐L1 inhibitor monotherapy has been limited to a large extent. In addition, the antitumor effect of combined CER and PD‐L1 inhibitor in ALK‐rearranged NSCLC is not fully understood. In H2228 cells, we examined the tumor killing effect of CER plus PD‐L1 inhibitor in vitro by quantitative RT‐PCR, flow cytometry, ELISA, western blot analysis, PBMC coculture system, and plasmid and transfection experiments. A Ba/F3 (EML4‐ALK‐WT) xenograft mouse model was also utilized to further evaluate the synergistic anticancer effects of CER and PD‐L1 inhibitor in vivo. The coculture system of PBMCs with H2228 cells promotes the expression of PD‐L1 and phospho‐ERK, and combined treatments facilitate lymphocyte proliferation and activation, inhibit PD‐L1 expression, and enhance lymphocyte cytotoxicity and cell death. In the in vivo NSCLC xenograft model, the volumes of tumors treated with CER and PD‐L1 inhibitor in combination were significantly smaller than those treated with CER or PD‐L1 alone. The relative tumor growth inhibitions were 84.9%, 20.0%, and 91.9% for CER, PD‐L1 inhibitor, and CER plus PD‐L1 groups, respectively. Ceritinib could synergize with PD‐1/PD‐L1 blockade to yield enhanced antitumor responses along with favorable tolerability of adverse effects. Ceritinib and PD‐L1 inhibitor combined produced a synergistic antineoplastic efficacy in vitro and in vivo, which provides a key insight and proof of principle for evaluating CER plus PD‐L1 blockade as combination therapy in clinical therapeutic practice.