The discovery and development of a novel irreversible EGFR/HER2 dual tyrosine kinase inhibitor SHR1258 (pyrotinib) for the treatment of HER2-postive breast cancer is presented. The structure-activity relationship of lead series and their pharmacokinetic properties were evaluated to identify the potential candidates for further in vivo efficacy studies and preclinical safety assessments. Metabolic pathway and drug-drug interaction were also investigated in preclinical settings. In particular, major metabolites in human and animal species were assessed with regard to potential toxicity or off-target side effects. Overall, the potent and selective EGFR/HER2 dual inhibitor, pyrotinib, displayed robust anti-tumor effects on HER2-overexpressing xenograft models and sufficiently safety windows in animals as well as favorable pharmacokinetic properties in human, which substantially ensures current clinical development. Finally, recent advances of pyrotinib in clinical studies are highlighted with very encouraging outcomes in patients with HER2-postive advanced breast cancer.Download high-res image (224KB)Download full-size image

Members of a series of 2,4,5-substituted pyrimidine derivatives were synthesized, and their interactions with tubulin and their antiproliferative activities against the human hepatocellular carcinoma cells of liver (BEL-7402) were evaluated. One member of this family, the indole-pyrimidine 4k, having an indole-aryl-substituted aminopyrimidine structure, was observed to be an excellent inhibitor of tubulin polymerization (IC50 = 0.79 μM) and to display significantly high antiproliferative activities against several cancer cell lines with IC50 values ranging from 16 to 62 nM. This substance displayed a high propensity to arrests cells at the G2/M phase of the cell cycle (EC50 = 20 nM). In addition, 4k was found to competitively inhibit colchicine binding to tubulin, indicating that it binds to the colchicine-binding site of tubulin. The observations made in this investigation demonstrate that 2,4,5-substituted pyrimidines represent a new class of tubulin polymerization inhibitors with significant antiproliferative activity.

Phytochemical investigation of the stems of Cucumis melo led to the isolation and identification of 21 cucurbitane-type triterpenoids, including nine new compounds (1−9) and 12 known compounds. Their structures were determined on the basis of spectroscopic analyses, chemical methods, and comparison with spectroscopic data in the literature. Two known compounds, cucurbitacin B (10) and cucurbitacin A (11), showed significant cytotoxic activity against the proliferation of A549/ATCC and BEL7402 cells in vitro. Of the new compounds, only compound 7 was weakly cytotoxic. The inhibitory effects of all compounds on the Jak-Stat3 signaling pathway were evaluated, but only cucurbitacin B (10) showed significant inhibitory activity of phosphotyrosine STAT3.

A series of novel 2,4,5-substituted pyrimidine derivatives were synthesized and evaluated for inhibition against the human hepatocellular carcinoma BEL-7402 cancer cell line. Several compounds showed potent inhibition with an IC50 value less than 0.10 μM. Structure–activity relationships for this class of compounds at the 2- and 5-position of the pyrimidine scaffold have been elucidated. The most active compound 7gc showed good inhibition of several different human cancer cell lines with IC50 values from 0.024 to 0.55 μM.A series of novel 2,4,5-substituted pyrimidine derivatives were synthesized and evaluated for inhibition against the human hepatocellular carcinoma BEL-7402 cancer cell line.

A series of E-ring γ-lactone camptothecin derivatives were synthesized by semi-synthesis via a three-step domino reaction. Their biological activity was evaluated on two types of human tumor cell lines A549 and HT-29 with sulforhodamine-B (SRB) method. The antitumor activity of these compounds was lower than SN-38, only compound 12c was found to be close to the activity of Topotecan. The structure–activity relationship (SAR) of these analogs was studied and discussed.The semi-synthesis and antitumor activity of a series of γ-lactone of camptothecin analogs is reported.

A series of 3-demethoxycarbonyl-3-carbamate methyl anhydrovinblastine derivatives (compounds 8b–32b) were designed, synthesized, and evaluated for their inhibition activities against human non-small cell lung cancer cell line (A549) and a human cervix epithelial adenocarcinoma cell line (HeLa). The structure–activity relationships of this new series are described in this paper. Cytotoxicity data revealed that the size of substituents and substitution position had important influence on cytotoxic activity. On two cell lines, compounds (8b and 30b) had more potent cytotoxic activity than the lead compound (1e, AVLB). The preliminary antitumor studies of 8b in vivo showed that it might be promising for the development of new antitumor agents.A new series of 3-demethoxycarbonyl-3-carbamate methyl anhydrovinblastine derivatives were synthesized and evaluated the cytotoxic activity in vitro against A549 and HeLa cell lines (IC50: 38–609 nM and 6–387 nM, respectively). The SARs of this new series are reported.

•RON is activated in lapatinib-resistant HER2-positivie breast cancer cells.•RON activation confers lapatinib resistance.•RON inhibition restores lapatinib sensitivity.•RON may be a promising target in breast cancer patients resistant to lapatinib.Lapatinib-resistance is a major problem for HER2-positive breast cancer treatment. SK-BR-3-LR, a lapatinib-resistant cell clone, was established from HER2-positive SK-BR-3 breast cancer cells following chronic exposure to lapatinib. The PI3K/AKT signaling pathway was demonstrated to be resistant to HER2 inhibition in SK-BR-3-LR cells. However, both small-molecular Recepteur d’Origine Nantais (RON) inhibitors and RON-targeted small interfering RNA (siRNA) effectively restored lapatinib sensitivity in these cells by inhibiting PI3K/AKT activation. Our results demonstrate for the first time the important role of RON in mediating lapatinib resistance and suggest that RON-targeted therapy may become a novel, promising therapeutic strategy after the failure of lapatinib treatment in patients with HER2-positive breast cancer.

(5R)-5-hydroxytriptolide (LLDT-8), a triptolide derivative, is a low-toxicity immunosuppressant in Phase I clinical trials. Here, we demonstrate that LLDT-8 displays broad-spectrum, potent (nanomolar level IC50s) antitumor activity, and induces S-phase cell-cycle arrest and apoptosis in vitro. Notably, LLDT-8 effectively overcomes multidrug resistance mediated by P-glycoprotein. In vivo, LLDT-8 demonstrates potent antitumor activity, particularly against human ovarian cancer 3AO and prostate cancer PC-3 xenografts in nude mice. The antitumor activity of LLDT-8 is achieved by virtue of its general inhibition of gene transcription. Our results indicate that LLDT-8 is a novel transcription inhibitor with potential for cancer therapy, particularly for cancers with drug resistance mediated by P-glycoprotein.