cabozantinib and Hypoxia

Multimodal treatment is an important tool to overcome tumor drug resistance. The reactive oxygen species (ROS) generated by photodynamic therapy (PDT) can directly play a killing role on tumor cells, which has the advantages of repeatable treatment and no drug resistance. However, its therapeutic oxygen consumption and destruction of tumor microvessels lead to hypoxia in tumor tissues, and hypoxia leads to overexpression of the receptor tyrosine kinase (c-MET) and vascular endothelial growth factor receptor (VEGFR). Overexpression of these two receptors leads to increased tumor invasiveness and metastasis. The molecularly targeted drug cabozantinib (CAB) has multiple targets, including anti-c-MET and VEGFR, to inhibit the development of hepatocellular carcinoma (HCC). In this study, our team designed a pH-sensitive nanoparticle CAB/Ce6@ZIF-8@PEG-FA (CCZP) loaded with CAB and Ce6, which exerted a multimodal therapeutic effect of PDT and molecularly targeted therapy by laser irradiation, and the PDT-induced overexpression of MET and VEGFR could also be inhibited by the target of CAB, thus reducing the invasive tumor cells metastasis. In summary, CCZP gives full play to the advantages of both drugs, exerting multimodal treatment while reducing HCC invasion and metastasis, providing a safe, potential approach to clinical treatment.

Topics: Carcinoma, Hepatocellular; Cell Line, Tumor; Combined Modality Therapy; Humans; Hydrogen-Ion Concentration; Hypoxia; Liver Neoplasms; Metal-Organic Frameworks; Nanoparticles; Photochemotherapy; Photosensitizing Agents; Vascular Endothelial Growth Factor A

Cabozantinib is a multi-targeted tyrosine kinase inhibitor targeting vascular endothelial growth factor (VEGF) receptor (VEGFR)-2, MET (c-Met, also called hepatocyte growth factor (HGF) receptor), and other receptor tyrosine kinases. Cabozantinib has recently been approved for treating advanced medullary thyroid carcinoma (MTC), but its long-term benefit remains uncertain and dose-dependent adverse events are very common. The present study has demonstrated that 2-methoxyestradiol (2ME2), an inhibitor of hypoxia-inducible factors (HIFs) and a promising anticancer agent under investigation in clinical trials, strengthens anticancer activities of cabozantinib against MTC cells in vitro and in vivo. The activated hypoxia-inducible pathways, which are mainly regulated by HIF-1, contribute to the resistance of hypoxic MTC cells to cabozantinib. Cabozantinib upregulated HIF-1α expression at translational levels and increased the expression of the downstream factors including VEGF, lactate dehydrogenase A (LDHA), HGF, and MET. 2ME2 corrected the activated pathways by cabozantinib through downregulating HIF-1α expression and inhibiting its nuclear translocation in hypoxic MTC cells. Administration of 2ME2 enhanced the efficacy of cabozantinib in suppressing the growth of MTC cell line xenografts and patient-derived xenografts established in mice. Given that 2ME2 targets insensitive hypoxic cancer cells to cabozantinib and can inhibit the activated pathways by cabozantinib, the present results warrant further investigation of 2ME2, particularly in combination with cabozantinib, for the treatment of MTC.

Topics: 2-Methoxyestradiol; Active Transport, Cell Nucleus; Adult; Anilides; Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Neuroendocrine; Cell Proliferation; Cell Survival; Estradiol; Female; Humans; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit; Isoenzymes; Ki-67 Antigen; L-Lactate Dehydrogenase; Lactate Dehydrogenase 5; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Pyridines; Signal Transduction; Thyroid Neoplasms; Xenograft Model Antitumor Assays