Cetuximab alone has a dose-dependent antitumor effect in oral cavity cancer cells: an in vitro study

Abstract:

Objective: To evaluate the antitumor effect of cetuximab as a single agent for the treatment of oral cavity cancers and to clarify the dosedependent growth inhibitory effect in oral cavity squamous cell carcinoma cell line (OCSCCCL).

Methods: The OCSCCCL (UPCI-SCC131) were cultured and continuously monitored using the xCELLigence RTCA SP instrument. Thereafter, they were divided into seven groups as: (i) negative control: medium+OCSCCCL, (ii) positive control: medium+OCSCCCL+cisplatin 10 μM/ml, (iii) medium+OCSCCCL+cetuximab 25 μg/ml, (iv) medium+OCSCCCL+cetuximab 50 μg/ml, (v) medium+OCSCCCL+ cetuximab 100 μg/ml, (vi) medium+OCSCCCL+cetuximab 200 μg/ml, (vii) medium+OCSCCCL+cetuximab 400 μg/ml. The cell index and viability were statistically analyzed and compared between groups.

Results: The distribution of cell index (mean value) and percentage of viability in groups were as follows: (i) 2.66 (100%), (ii) 0.17 (6.08%), (iii) 2.28 (85.71%), (iv) 2.31 (86.84%), (v) 1.92 (72.18%), (vi) 1.79 (67.29%), (vii) 0.28 (10.53%). The change trend in drug concentration was statistically different in all study groups to which cetuximab was administered (Pillai’s trace; p<0.0001). The antitumor effect of cetuximab was initially detected at a dose of 100 μg/mL, when compared with negative control (p=0.01). However, a dose of 400 μg/mL was required in order to have a statistically similar antitumor effect of cisplatin at a dose of 10 μM.

Conclusion: Cetuximab alone is a potentially effective chemotherapeutic agent and has a concentration-dependent growth inhibitory effect in OCSCCCL. The antitumor activity of cetuximab was initially detected at a dose of 100 μg/mL. However, significant antitumor effect was determined at a dose of 400 μg/mL.