Deregulated Cyclin D1 Expression Is Associated with Decreased Efficacy of the Selective Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Gefitinib in Head and Neck Squamous Cell Carcinoma Cell Lines

To date, clinical studies combining the new generation of targeted therapies and chemotherapy have had mixed results. Preclinical studies can be used to identify potential antagonism/synergy between certain agents, with the potential to predict the most efficacious combinations for further investigation in the clinical setting. In this study, we investigated the sequence-dependent interactions of ZD6474 with oxaliplatin in two human colon cell lines in vitro. We evaluated the in vitro antitumor activity of ZD6474, an inhibitor of vascular endothelial growth factor receptor (VEGFR), epidermal growth factor receptor (EGFR) and RET tyrosine kinase activity, and oxaliplatin using three combination schedules: ZD6474 before oxaliplatin, oxaliplatin before ZD6474, and concurrent exposure. Cell proliferation studies showed that treatment with oxaliplatin followed by ZD6474 was highly synergistic, whereas the reverse sequence was clearly antagonistic as was concurrent exposure. Oxaliplatin induced a G 2 -M arrest, which was antagonized if the cells were previously or concurrently treated with ZD6474. ZD6474 enhanced oxaliplatin-induced apoptosis but only when added after oxaliplatin. The sequence-dependent antitumor effects appeared, in part, to be based on modulation of compensatory prosurvival pathways. Thus, expression of total and active phosphorylated EGFR, as well as AKT and extracellular signal-regulated kinase, was markedly increased by oxaliplatin. This increase was blocked by subsequent treatment with ZD6474. Furthermore, the synergistic sequence resulted in reduced expression of insulin-like growth factor-I receptor and a marked reduction in secretion of vascular endothelial growth factor protein. ZD6474 in combination with oxaliplatin has synergistic antiproliferative properties in human colorectal cancer cell lines in vitro when oxaliplatin is administered before ZD6474.

Section: Discussionsupporting

confidence: 86%

“…3B). Several proteins, such as ChK2, p21, and cyclin D1, are involved in the regulation of the cell cycle (42,43). We next evaluated the effects of the three sequences on the expression of these proteins.…”

Section: Cell Cycle Arrest By Oxaliplatin Is Modulated By Sequence-dementioning

confidence: 99%

Sequence-dependent inhibition of human colon cancer cell growth and of prosurvival pathways by oxaliplatin in combination with ZD6474 (Zactima), an inhibitor of VEGFR and EGFR tyrosine kinases

Troiani

Lockerbie

Morrow

et al. 2006

“…Cyclin D1 was also demonstrated to be implicated in resistance to inhibitors of ERBB2, EGFR, and ER signaling (32,33). Recent studies suggest that cyclin D1 overexpression may be sufficient to render B-RAF V600E melanoma cells resistant to B-RAF inhibition (28).…”

Section: Discussionmentioning

confidence: 99%

The CDK4/6 Inhibitor LY2835219 Overcomes Vemurafenib Resistance Resulting from MAPK Reactivation and Cyclin D1 Upregulation

Yadav

Burke

Huber

et al. 2014

116

117

B-RAF selective inhibitors, including vemurafenib, were recently developed as effective therapies for melanoma patients with B-RAF V600E mutation. However, most patients treated with vemurafenib eventually develop resistance largely due to reactivation of MAPK signaling. Inhibitors of MAPK signaling, including MEK1/2 inhibitor trametinib, failed to show significant clinical benefit in patients with acquired resistance to vemurafenib. Here, we describe that cell lines with acquired resistance to vemurafenib show reactivation of MAPK signaling and upregulation of cyclin D1 and are sensitive to inhibition of LY2835219, a selective inhibitor of cyclin-dependent kinase (CDK) 4/6. LY2835219 was demonstrated to inhibit growth of melanoma A375 tumor xenografts and delay tumor recurrence in combination with vemurafenib. Furthermore, we developed an in vivo vemurafenib-resistant model by continuous administration of vemurafenib in A375 xenografts. Consistently, we found that MAPK is reactivated and cyclin D1 is elevated in vemurafenib-resistant tumors, as well as in the resistant cell lines derived from these tumors. Importantly, LY2835219 exhibited tumor growth regression in a vemurafenib-resistant model. Mechanistic analysis revealed that LY2835219 induced apoptotic cell death in a concentration-dependent manner in vemurafenib-resistant cells whereas it primarily mediated cell-cycle G 1 arrest in the parental cells. Similarly, RNAi-mediated knockdown of cyclin D1 induced significantly higher rate of apoptosis in the resistant cells than in parental cells, suggesting that elevated cyclin D1 activity is important for the survival of vemurafenib-resistant cells. Altogether, we propose that targeting cyclin D1-CDK4/6 signaling by LY2835219 is an effective strategy to overcome MAPK-mediated resistance to B-RAF inhibitors in B-RAF V600E melanoma.

“…Tissue culture and cisplatin treatment HNSCC cell lines were obtained from the American Type Culture Collection and cultured as described (8). In the drug treatment experiments, cells were treated with cisplatin [cis-diamminedichloridoplatinum(II) CDDP; InterPharma] for 48 hours.…”

Section: Methodsmentioning

confidence: 99%

Cisplatin Treatment Induces a Transient Increase in Tumorigenic Potential Associated with High Interleukin-6 Expression in Head and Neck Squamous Cell Carcinoma

Poth

Guminski

Thomas

et al. 2010

Head and neck squamous cell carcinoma (HNSCC) is characterized by the 5-year survival rate of ∼50%. Despite aggressive surgical, radiation, and chemotherapeutic interventions, 30% to 40% of patients die from the development of recurrent or disseminated disease that is resistant to chemotherapy. As a model of recurrence, we examined the effects of cisplatin on the ability of head and neck cancer cells to initiate tumors in a xenotransplant model. HNSCC cells were treated in vitro with cisplatin at a concentration that elicited >99% cytotoxicity and assessed for tumorigenic potential in nonobese diabetic/severe combined immunodeficient mice. HNSCC cells that survived cisplatin treatment formed tumors in nonobese diabetic/severe combined immunodeficient mice more efficiently than nontreated cells. Cisplatin-resistant cells were characterized using clonal analysis, in vivo imaging, and transcriptomic profiling. Preliminary functional assessment of a gene, interleukin-6 (IL-6), highly upregulated in cisplatin-treated cells was carried out using clonogenicity and tumorigenicity assays. We show that cisplatin-induced IL-6 expression can contribute to the increase in tumorigenic potential of head and neck cancer cells but does not contribute to cisplatin resistance. Finally, through clonal analysis, we show that cisplatin-induced IL-6 expression and cisplatin-induced tumorigenicity are stochastically derived. We report that cisplatin treatment of head and neck cancer cells results in a transient accumulation of cisplatin-resistant, small, and IL-6-positive cells that are highly tumorigenic. These data also suggest that therapies that reduce IL-6 action may reduce recurrence rates and/or increase disease-free survival times in head and neck cancer patients, and thus, IL-6 represents a promising new target in HNSCC treatment. Mol Cancer Ther; 9(8); 2430-9. ©2010 AACR.