Effects of the administration of epidermal growth factor receptor specific inhibitor cetuximab, alone and in combination with cisplatin, on proliferation and apoptosis of Hep-2 laryngeal cancer cells

In Vitro Study of Synergic Effect of Cisplatin and Low Molecular Weight Heparin on Oral Squamous Cell Carcinoma

Objectives

To evaluate the possible synergic effect of cisplatin and low molecular weight heparin (LMWH) on oral squamous cell carcinoma (OSCC).

Materials and Methods

Cisplatin and enoxaparin sodium, alone or in combination, were administered at doses of 1, 2, 4, 8 and 10 µM and 0.1, 0.5, 1, 5, 10, 50, and 100 µg/ml, respectively, to the H357 human OSCC line. The effects on cell viability and apoptosis were evaluated after 24, 48, and 72 h and on cell migration after 18 and 24 h.

Results

10 µM concentration of cisplatin produced the greatest decrease in cell viability, with significant differences at 24 (p=0.009), 48 (p=0.001) and 72 h (p = 0.003); the 100 µg/ml dose of enoxaparin produced the greatest decrease in cell viability but without significant differences (p>0.05). When different concentrations of cisplatin and enoxaparin were combined, it was found that 100 µg/ml enoxaparin sodium produced the greatest synergic effect on cell viability reduction. In analyses of apoptosis and cell migration, it was found that the combination of cisplatin at 8 or 10 μM and 100 μg/ml enoxaparin produced a higher rate of apoptosis at 24, 48, and 72 h and a greater reduction in cell migration at 18 and 24 h.

Conclusions

A combination of cisplatin and enoxaparin sodium shows a synergic effect that reduces cell viability and cell migration capacity and increases the apoptosis of human OSCC cells.

Clinical relevance

Enoxaparin may be beneficial in chemotherapy for patients with OSCC; this finding requires further clinical and laboratory investigation.

Cetuximab enhances cisplatin-induced endoplasmic reticulum stress-associated apoptosis in laryngeal squamous cell carcinoma cells by inhibiting expression of TXNDC5

Cisplatin and cetuximab, an anti‑epidermal growth factor receptor (EGFR) monoclonal humanized antibody, have been used for treatment of laryngeal squamous cell carcinoma (LSCC). It has been demonstrated that cisplatin and inhibition of EGFR signaling may induce endoplasmic reticulum (ER) stress‑associated apoptosis. However, ER protein thioredoxin domain‑containing protein 5 (TXNDC5) reportedly protects cells from ER stress‑associated apoptosis. The present study investigated the interaction between cisplatin, cetuximab and TXNDC5 on ER stress‑associated apoptosis in LSCC cells. AMC‑HN‑8 human LSCC cells with or without TXNDC5 overexpression or knockdown were treated with cisplatin (5, 10, 20 and 40 µM) and/or cetuximab (10, 50, 100 and 150 µg/ml), for 12, 24, 36 and 48 h. Cisplatin and cetuximab concentration‑ and time‑dependently increased and decreased the expression of TXNDC5 in AMC‑HN‑8 cells, respectively. Knockdown of TXNDC5 markedly augmented cisplatin‑induced levels of CCAAT/enhancer‑binding protein homologous protein (CHOP), caspase‑3 activity and apoptosis; while overexpression of TXNDC5 largely eliminated cetuximab‑induced levels of CHOP, caspase‑3 activity and apoptosis. Cisplatin and cetuximab demonstrated a combinatorial effect on increasing the levels of CHOP, caspase‑3 activity and apoptosis, which was largely eliminated by overexpression of TXNDC5 or a reactive oxygen species (ROS) scavenger/antagonist. In addition, promoter/luciferase reporter assays revealed that cisplatin and cetuximab regulated the expression of TXNDC5 at the gene transcription/promoter level. In conclusion, the findings suggested that ER stress‑associated apoptosis is a major mechanism underlying the apoptotic effect of cisplatin and cetuximab on LSCC cells; cetuximab enhanced cisplatin‑induced ER stress‑associated apoptosis in LSCC cells largely by inhibiting the expression of TXNDC5 and thereby increasing ROS production; cisplatin and cetuximab had stimulatory and inhibitory effects on the TXNDC5 gene promoter, respectively. The present study offered novel insights into the pharmacological effects of cisplatin and cetuximab on LSCC. It also suggested that TXNDC5 may be a potential therapeutic target for LSCC.

Minichromosome maintenance protein 7 and geminin expression: Prognostic value in laryngeal squamous cell carcinoma in patients treated with radiotherapy and cetuximab

BACKGROUND

Minichromosome maintenance protein 7 (MCM7) is a downstream of human epidermal growth receptor (HER1) signaling. We examined MCM7, geminin, and HER1 expression in patients with laryngeal squamous cell carcinoma (SCC) treated with radiotherapy and cetuximab.

METHODS

MCM7, geminin, and HER1 were evaluated by immunohistochemistry on 61 patients with laryngeal SCC. The follow-up (median, 32.1 months; range, 2-139 months) went from the beginning of therapy to tumor progression-free survival (PFS) and death (overall survival [OS]).

RESULTS

MCM7, but not geminin, was associated only with HER1 expression, whereas no association was found with other clinicopathological characteristics. Patients with MCM7 high - geminin high and MCM7 high - geminin low tumor status had a risk of progression 3.1 times and 17.7 times greater, respectively, than patients with MCM7 low - geminin high tumor status. Tumor site, MCM7, and geminin were independent determinants of PFS, whereas MCM7 was an independent prognostic marker of OS.

CONCLUSION

MCM7-geminin tumor status may be prognostic for patients with laryngeal SCC treated with cetuximab and radiotherapy. © 2016 Wiley Periodicals, Inc. Head Neck 39: 684-693, 2017.