Sequence dependence of cell growth inhibition by EGFR-tyrosine kinase inhibitor ZD1839, docetaxel, and cisplatin in head and neck cancer

Genomic Correlate of Exceptional Erlotinib Response in Head and Neck Squamous Cell Carcinoma

IMPORTANCE

Randomized clinical trials demonstrate no benefit for epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors in unselected patients with head and neck squamous cell carcinoma (HNSCC). However, a patient with stage IVA HNSCC received 13 days of neoadjuvant erlotinib and experienced a near-complete histologic response.

OBJECTIVE

To determine a mechanism of exceptional response to erlotinib therapy in HNSCC.

DESIGN, SETTING, AND PARTICIPANTS

Single patient with locally advanced HNSCC who received erlotinib monotherapy in a window-of-opportunity clinical trial (patients scheduled to undergo primary cancer surgery are treated briefly with an investigational agent). Whole-exome sequencing of pretreatment tumor and germline patient samples was performed at a quaternary care academic medical center, and a candidate somatic variant was experimentally investigated for mediating erlotinib response.

INTERVENTION

A brief course of erlotinib monotherapy followed by surgical resection.

MAIN OUTCOMES AND MEASURES

Identification of pretreatment tumor somatic alterations that may contribute to the exceptional response to erlotinib. Hypotheses were formulated regarding enhanced erlotinib response in preclinical models harboring the patient tumor somatic variant MAPK1 E322K following the identification of tumor somatic variants.

RESULTS

No EGFR alterations were observed in the pretreatment tumor DNA. Paradoxically, the tumor harbored an activating MAPK1 E322K mutation (allelic fraction 0.13), which predicts ERK activation and erlotinib resistance in EGFR-mutant lung cancer. The HNSCC cells with MAPK1 E322K exhibited enhanced EGFR phosphorylation and erlotinib sensitivity compared with wild-type MAPK1 cells.

CONCLUSIONS AND RELEVANCE

Selective erlotinib use in HNSCC may be informed by precision oncology approaches.

Phase III randomized, placebo-controlled trial of docetaxel with or without gefitinib in recurrent or metastatic head and neck cancer: an eastern cooperative oncology group trial

PURPOSE

We hypothesized that the addition of gefitinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, to docetaxel would enhance therapeutic efficacy in squamous cell carcinoma of the head and neck (SCCHN).

PATIENTS AND METHODS

Patients with recurrent or metastatic SCCHN with Eastern Cooperative Oncology Group (ECOG) performance status of 2, or patients with ECOG performance status of 0 to 2 but were previously treated with chemotherapy, were randomly assigned to receive weekly docetaxel plus either placebo (arm A) or gefitinib 250 mg/d, orally (arm B) until disease progression. At the time of progression, patients in the placebo arm could receive single-agent gefitinib. EGFR, c-MET, and KRAS mutations and polymorphisms in drug metabolizing enzymes and transporters were evaluated by pyrosequencing.

RESULTS

Two hundred seventy patients were enrolled before the study was closed early at interim analysis (arm A, n = 136; arm B, n = 134). Median overall survival was 6.0 months in arm A versus 7.3 months in arm B (hazard ratio, 0.93; 95% CI, 0.72 to 1.21; P = .60). An unplanned subset analysis showed that gefitinib improved survival in patients younger than 65 years (median 7.6 v 5.2 months; P = .04). Also, there was a trend for improved survival in patients with c-MET wild-type (5.7 v 3.6 months; P = .09) regardless of treatment. Grade 3/4 toxicities were comparable between the two arms except that grade 3/4 diarrhea was more common with docetaxel/gefitinib. Of 18 eligible patients who received gefitinib after disease progression in arm A, one patient had a partial response.

CONCLUSION

The addition of gefitinib to docetaxel was well tolerated but did not improve outcomes in poor prognosis but otherwise unselected patients with SCCHN.

[Sequence-dependent effect of docetaxel with gefitinib on the proliferation and apoptosis of lung adenocarcinoma cell H1975]

BACKGROUND AND OBJECTIVE

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib show promising therapeutic effects in patients with advanced non-small cell lung cancer (NSCLC). However, despite an initial response to EGFR-TKIs treatment among responsive patients, most inevitably acquire resistance after a progression-free period of about 10 months. The percentage of T790M in TKI acquired-resistant patients in most studies is around 50%. The aim of this study is to assess the effects of the sequential administration of docetaxel and gefitinib on cell proliferation and apoptosis of lung adenocarcinoma cell H1975.

METHODS

An MTT assay was used to measure cell proliferation. The potency of the sequential administration of docetaxel and gefitinib were determined by isobolograms and combination index (CI). Cell apoptosis and cycle distribution were determined by flow cytometry. The Hoechst 33258 method was used to observe the apoptotic morphology. Chemical colorimetric luminescence was used to measure the caspase activity.

RESULTS

The isobolograms and CI showed that the sequential administration of docetaxel following gefitinib remarkably inhibits cell proliferation and cell apoptosis compared with other sequential administration models. The cycle distribution results indicate that sequential docetaxel administration following gefitinib blocked the cells in the G₂/M phase but not in the G0/G1. The activation of the Caspase-8/Caspase-3 cascade is mainly involved in the apoptotic pathway of lung adenocarcinoma cell H1975 in all sequential administration models.

CONCLUSIONS

The docetaxel administration following gefitinib might be a new stratagy for lung cancer with T790M mutation after having EGFR-TKIs resistance.

EGFR inhibitor enhances cisplatin sensitivity of human glioma cells

Epidermal growth factor receptor (EGFR) is found to express at high levels in a variety of solid tumors including gliomas. This study was to examine the effect of an EGFR-tyrosine kinase inhibitor (AG1478) alone or in combination with cisplatin (CDDP) on the growth of glioma cells (U87). U87 glioma cells were treated with AG1478 (10 μmol/L) or CDDP (25 μmol/L) as a single agent or in combination for 24 or 48 h. The expression of EGFR and the components in its downstream signaling pathway [extracellular signal-regulated kinase (ERK), protein kinase B (AKT)] in U87 glioma cells was detected by Western blotting. Cell growth, cell cycle distribution and cell apoptosis were determined by MTT method and flow cytometry, respectively. The results showed that CDDP could induce the activation of EGFR and the components in its downstream signaling pathways in a concentration-dependent manner. The combined treatment of AG1478 with CDDP could inhibit the proliferation of U87 glioma cells, arrest the cell cycle and promote cell apoptosis. In the EGFR signaling pathway, AG1478 decreased the phosphorylation of ERK, AKT and EGFR in U87 glioma cells. It was concluded that the combined treatment of AG1478 and CDDP may exert synergistic inhibitory effects on the growth of glioma cells by suppressing the activities of EGFR, AKT and ERK.