ZD6474, a dual tyrosine kinase inhibitor of EGFR and VEGFR-2, inhibits MAPK/ERK and AKT/PI3-K and induces apoptosis in breast cancer cells

Abstract

Abnormalities in gene expression and signaling pathways downstream of the epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor (VEGFR) contribute to the progression, invasion, and maintenance of the malignant phenotype in human cancers, including breast. Consequently, the dual kinase inhibitor of EGFR and VEGFR ZD6474 represents a promising biologically-based treatment that is currently undergoing clinical trials for non-small cell lung cancer. Patients suffering from breast cancers have a poor prognosis because of the lack of effective agents and treatment strategies. We hypothesized that inhibition of phosphorylation of the EGFR and VEGFR by ZD6474 would inhibit breast cancer cell proliferation and induce apoptosis. This hypothesis was tested using human breast cancer cell lines. ZD6474 inhibited cell proliferation in a dose-dependent manner, by blocking cell progression at the G(0)-G(1) stage, through downregulation of expression of cyclin D1 and cyclin E. In vitro, ZD6474 inhibited growth factor-induced phosphorylation of EGFR, VEGFR-2, MAPK and Akt. ZD6474 also downregulated anti-apoptotic markers including Bcl-2, upregulated pro-apoptotic signaling events involving expression of bax, activation of caspase-3, and induction of poly (ADP-ribose) polymerase during apoptosis. ZD6474 inhibited anchorage independent colony formation using soft agar assays, and invasion of breast cancer cells in vitro using Boyden chamber assays. In a xenograft model using human MDA-MB-231 breast cancer cells, ZD6474 inhibited tumor growth and induced cancer-specific apoptosis. Collectively, these data imply that ZD6474 a dual kinase inhibitor has potential for the targeted therapy of breast cancer.

Antiproliferative and proapoptotic activity of CLM3, a novel multiple tyrosine kinase inhibitor, alone and in combination with SN-38 on endothelial and cancer cells

“…Actually, the novel inhibitor CLM3 displayed significant antiproliferative and pro-apoptotic effects on endothelial and cancer cells, with a mechanism mediated by the inhibition of phosphorylation of ERK1/2 and Akt, respectively. In this, CLM3 shows a similar behaviour to other small molecules that inhibit EGFR and VEGFR-2, such as vandetanib [36,37], or VEGFR-2 such as axitinib [38,39], which have been shown to inhibit in vitro both ERK1/2 and Akt phosphorylation in endothelial and cancer cells. .…”

“…Activators of cyclin D1 gene transcription are mitogenic growth factors, and, it has been described that also nuclear EGFR is able to bind the cyclin D1 promoter, promoting the gene transcription [47]. Interestingly, also vandetanib inhibited cell proliferation in a dose-dependent manner, by blocking cell progression at the G0-G1 stage, through the downregulation of expression of cyclin D1 and cyclin E [37].…”

Environmental toxicants and male reproductive function

“…There are recent advances in the field using inhibitors against different MAPKs to treat various pathological conditions, mostly notably cancer, heart disease and pulmonary disease. [65][66][67][68] While many of these studies are in the stage of laboratory-based in vitro testing and studies, 65,67 several of these MAPK inhibitors or related kinase inhibitors have moved onto clinical studies. 66,68 Some of these clinical studies are now at the stages of data collection and analysis prior to the publication in peer-reviewed journals regarding their use to treat different illnesses ranging from late stage cancers to heart disease and inflammatory disorders (see www.ciscrp.org, www.nih.gov or www.cancer.gov for selected and additional references).…”

AEE788 potentiates celecoxib-induced growth inhibition and apoptosis in human colon cancer cells

“…Cell extracts were separated on SDS-PAGE, transferred to nitrocellulose membranes, blocked with 2% BSA and probed with the appropriate antibodies. Membranes were then developed using enhanced chemiluminescence or alkaline phosphatasebased colorimetric methods (Sarkar et al, 2010.…”