Design and optimization of orally spleen tyrosine kinase (SYK) inhibitors for treatment of solid tumor.

As the aim to discover orally SYK inhibitors for solid tumor treatment, a series of novel derivatives based on imidazo[1,2-a]pyrazine scaffold were designed, synthesized and evaluated. Structure-activity relationship study of both enzymatic and cellular assays led to the identification of compound 12f. The novel SYK inhibitor 12f showed potent antitumor activity against solid tumors with favorable drug-like properties of lipophilicity and solubility. 12f could induce cell apoptosis of ovarian and lung cancer cell lines. In SKOV3 xenograft mouse model, oral administration of 12f led to significant tumour regression without obvious toxicity. 12f improved the limited response of traditional SYK inhibitors in solid tumors in vitro and in vivo. Taken together, this compound may act as a promising lead compound for further development of new SYK inhibitors for solid tumor therapy.

Enhancement of Histone Deacetylase Inhibitor Sensitivity in Combination with Cyclin-Dependent Kinase Inhibition for the Treatment of Oral Squamous Cell Carcinoma.

BACKGROUND/AIMS: Previous research has indicated that the currently available histone deacetylase inhibitors (HDACis) are not effective as monotherapies against oral squamous cell carcinoma (OSCC). However, HDACis act synergistically with other therapeutic agents to exert significant antitumor activities. Thus, a strategy to develop chemotherapeutic agents by combining several active groups based on histone deacetylase (HDAC) into a single molecule as a conjugate that modulates multiple cellular pathways may be useful for the treatment of OSCC. METHODS: The novel inhibitor Roxyl-ZR was prepared by organic synthesis and its anticancer effects on OSCC were investigated by cell metabolism (n=5), colony formation (n=3), cell cycle (n=3), cell apoptosis (n=3), wound healing (n=3), transwell migration (n=3), and 5-bromo-2'-deoxyuridine staining (n=3) assays in vitro and in in vivo xenograft mice models (4 mice/group for subcutaneous xenograft and 3 mice/group for orthotopic xenograft ). The abundance of Ki67, Bcl-2, and p-STAT3 was detected by immunohistochemistry staining (n=4). Apoptotic cells in the tumor tissues of mice were detected by terminal deoxynucleotidyl transferase dUTP nickend labeling assay (n=3). The abundance of related proteins levels were evaluated by western blot (n=3). E-cadherin expression was detected by an immunofluorescence assay (n=3). RESULTS: Compared with the approved HDACi, conjugated Roxyl-ZR exhibited significantly higher antitumor effects in OSCC cells. Roxyl-ZR suppressed OSCC cell proliferation by inducing the reduction of S phase and inducing caspase-dependent apoptosis by down-regulating Bcl-2 expression. Moreover, Roxyl-ZR attenuated the epithelial-mesenchymal transition, which is closely associated with migration and invasion. In addition, Roxyl-ZR inhibited OSCC xenograft mice models and showed low toxicity. The mechanism underlying the Roxyl-ZR-enhanced sensitivity to HDACi may be attributed to the inhibition of key regulators of JAK1-STAT3 signaling pathway. CONCLUSION: HDAC-cyclin-dependent kinase conjugates represent a novel approach to the development of OSCC treatment. Our findings may open a new avenue for the development of novel inhibitors for the treatment of OSCC.

Novel EGFR inhibitors against resistant L858R/T790M/C797S mutant for intervention of non-small cell lung cancer.

To overcome C797S mutation, the latest and most common resistance mechanism in the clinical treatment of third-generation EGFR inhibitor, a novel series of substituted 6-(2-aminopyrimidine)-indole derivatives were designed and synthesized. Through the structure-activity relationship (SAR) study, compound 11eg was identified as a novel and potent EGFR L858R/T790M/C797S inhibitor (IC50 = 0.053 µM) but had a weak effect on EGFRWT (IC50 = 1.05 µM). 11eg significantly inhibited the proliferation of the non-small cell lung cancer (NSCLC) cells harboring EGFRL858R/T790M/C797S with an IC50 of 0.052 µM. 11eg also showed potent inhibitory activity against other NSCLC cell lines harboring main EGFR mutants. Furthermore, 11eg exhibited much superior activity in arresting cell cycle and inducing apoptosis of NSCLC cells with mutant EGFRC797S. It blocked cellular EGFR signaling. Importantly, 11eg markedly suppressed the tumor growth in in vivo xenograft mouse model with good safety. Additionally, 11eg displayed good microsomal stability. These results demonstrated the potential of 11eg with novel scaffold as a promising lead compound targeting EGFRC797S to guide in-depth structural optimization.

Novel dual inhibitors targeting CDK4 and VEGFR2 synergistically suppressed cancer progression and angiogenesis.

Based on the significantly synergistic effects of CDK4 and VEGFR2 inhibitors on growth of cancer cells, a series of novel multi-kinase inhibitors targeting CDK4 and VEGFR2 were designed, synthesized and evaluated, among which Roxyl-ZV-5J exhibited potent and balanced activities against both CDK4 and VEGFR2 with half-maximal inhibitory concentration at the nanomolar level. It effectively induced breast and cervical cancer cell cycle arrest and cell apoptosis. Roxyl-ZV-5J also inhibited the proliferation, tube formation and VEGFR2 downstream signaling pathways of HUVECs. Oral administration of Roxyl-ZV-5J led to significant tumor regression and anti-angiogenesis without obvious toxicity in SiHa xenograft mouse model. In addition, this compound showed good pharmacokinetics. This study confirmed a new tool for dual CDK-VEGFR2 pathways inhibition achieved with a single molecule, which provided valuable leads for further structural optimization and anti-angiogenesis and anti-tumor mechanism study.

Highly Selective, Potent, and Oral mTOR Inhibitor for Treatment of Cancer as Autophagy Inducer.

On the basis of novel pyrazino[2,3-c]quinolin-2(1H)-one scaffold, we designed and identified a highly selective, potent and oral mTOR inhibitor, 9m. Compound 9m showed low nanomolar activity against mTOR (IC50 = 7 nM) and greater selectivity over the related PIKK family kinases, which demonstrated only modest activity against 3 out of the 409 protein kinases. In vitro assays, compound 9m exhibited high potency against human breast and cervical cancer cells and induced tumor cell cycle arrest and autophagy. 9m inhibited cellular phosphorylation of mTORC1 (pS6 and p4E-BP1) and mTORC2 (pAKT (S473)) substrates. In T-47D xenograft mouse model, oral administration of compound 9m led to significant tumor regression without obvious toxicity. In addition, this compound showed good pharmacokinetics. Collectively, due to its high potency and selectivity, compound 9m could be used as a mTOR drug candidate.

Analyte-triggered autocatalytic amplification combined with gold nanoparticle probes for colorimetric detection of heavy-metal ions.

This work reports a new colorimetric nanosensor for the detection of heavy-metal ions that initially integrates analyte-triggered autocatalytic amplification with o-phenylenediamine-mediated aggregation of label-free gold nanoparticles. Its utility is well demonstrated with the simple, rapid, sensitive, and specific detection of Hg2+, Cu2+, and Ag+ targets with detection limits less than 3 nM.