LOXL4 as a selective molecular marker in primary and metastatic head/neck carcinoma

Overexpression of the lysyl oxidase-like 4 (LOXL4) gene is associated with a variety of human malignancies. The purpose of this study was to compare the gene expression of LOXL4 to the expression of epidermal growth factor receptor (EGFR) in head and neck squamous cell carcinomas. The overexpression of EGFR has been well examined and already serves as a therapeutic target. The expression of both genes was compared in head and neck squamous cell carcinomas and their diagnostic and prognostic value was evaluated.

Messenger RNA from 58 head and neck carcinomas and 11 healthy upper aerodigestive tract mucosa samples was extracted and subjected to electrophoresis. Northern hybridisation was carried out using digoxigenin-labelled gene-specific probes, and the level of gene expression was measured by densitometry.

High expression of LOXL4 gene was detected in 71% of all carcinomas and only in 9% of the healthy mucosa samples (p=0.0002). In comparison, a high level of expression was detected for the EGFR gene in 78% of the carcinomas and in 36% of normal mucosa (p=0.01).

Although both genes revealed a similar level of overexpression in the carcinoma samples, it was found that the a notably higher percentage of healthy mucosa tested positively for EGFR than LOXL4, indicating that LOXL4 may serve as a selective molecular marker in primary and metastatic head and neck carcinoma.