Anlotinib, a novel small molecular tyrosine kinase inhibitor, suppresses growth and metastasis via dual blockade of VEGFR2 and MET in osteosarcoma.

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents, with highly aggressive behavior and early systemic metastasis. The survival rates for osteosarcoma remain unchanged over the past two decades. Studies aiming to find new or alternative therapies for patients with refractory osteosarcoma are urgently needed. Anlotinib, a novel multi-targeted tyrosine kinase inhibitor (TKI), has exhibited encouraging clinical activity in NSLCC and soft tissue sarcoma, whereas its effect on osteosarcoma has not been studied. In our study, we investigated the anti-tumor activity and underlying mechanism of anlotinib in osteosarcoma. Various in vitro and in vivo models of human osteosarcoma were used to determine the anti-proliferative, anti-angiogenesis and anti-metastasis efficacy of anlotinib. Our results showed that anlotinib suppressed tumor growth and increased the chemo-sensitivity of osteosarcoma. In addition, anlotinib inhibited migration and invasion in osteosarcoma cells. Furthermore, in order to explore the anti-tumor mechanism of anlotinib, phospho-RTK antibody arrays were performed. These analyses confirmed that anlotinib suppressed the phosphorylation of MET, VEGFR2 and the downstream signaling pathway activation. Moreover, we demonstrated that anlotinib blocked hepatocyte growth factor (HGF)-induced cell migration, invasion and VEGF-induced angiogenesis. Notably, a 143B-Luc orthotopic osteosarcoma model further showed that anlotinib significantly inhibited growth and lung metastasis of implanted tumor cells. Our preclinical work indicates that anlotinib acts as a novel inhibitor of VEGFR2 and MET that blocks tumorigenesis in osteosarcoma, which could be translated into future clinical trials.

P21 (waf1/cip1) is required for non-small cell lung cancer sensitive to Gefitinib treatment.

Lung cancer is the leading cause of death from cancer in the world. Gefitinib is known to its inhibition of EGFR tyrosine kinase and worldwide used for antitumor in non-small cell lung cancer (NSCLC). Here, we show that Gefitinib reduces p-Akt levels, concomitant with elevation of p21 levels and suppression of cdk2/4 and cyclinE/D1 activities which result in impaired cell cycle progression through G1 arrest only in NSCLC cells in which it inhibits growth. We find that Gefitinib-induced p21 protein stability, rather than increased RNA accumulation, was responsible for the elevated p21 levels. More, treatment of beta-elemene, a natural plant drug extracted from Curcuma wenyujin, restored sensitivity to Gefitinib via the mechanism modulated the elevation of p21 levels in the cells which are acquired resistance to Gefitinib. These data suggest that administration of Gefitinib in combination with beta-elemene may offer great opportunities for NSCLC which are acquired resistance to Gefitinib. The p21 effect on the cells to response to Gefitinib was further confirmed by p21 over-expression and knockdown studies pointing to a requirement of p21 for the cells sensitive to Gefitinib. Thus, we propose that p21 is required for Gefitinib-sensitive NSCLC cells.

[Studies on the target cells and molecules with sodium valproate induced differential of human glioma cells].

OBJECTIVE: To investigate the target cells and molecules with sodium valproate induced differentiation of human glioma cells. METHODS: Nude mice bearing human glioma xenogenic graft subcutaneously were treated with sodium valproate. The expressions of HDAC1 and Tob genes of xenografts were analyzed with semiquantitative RT-PCR. The CD133+ cells (BTSCs) were isolated from glioma specimens by immunomagnetic sorting, and cultured in the medium containing FCS or in the serum-free medium supplemented with growth factors, respectively, followed by treatment with sodium valproate in vitro for 21 days. The cell surface markers were detected with flow cytometry and confocal microscopy. RESULTS: Sodium valproate inhibited the growth of subcutaneous xenografs bearing on nude mice (P<0.05), and up-regulated the HDAC1 expression (P<0.01), down-regulated the Tob expression (P<0.05). The cell surface markers of BTSCs were detected by flow cytometry after sodium valproate treatment for 21 days. In the FCS group, the GFAP or beta-tubulin III positive cells increased significantly (P<0.01), but in the growth factor group, no statistical differences were observed in the GFAP or beta-tubulin III expression (P>0.05). The results of confocal microscopy indicated that the GFAP+ or beta-tubulin III+ cells coexpressed with Nestin. CONCLUSIONS: HDAC1 and Tob genes were the potential target molecules in reversion of the differential inhibition of human glioma cells with sodium valproate. The BTSCs undergoing the processes of differentiation were the target cells for sodium valproate.