Metallothionein gene expression is altered in oral cancer and may predict metastasis and patient outcomes

Aims Metallothioneins ( MT s) are proteins associated with the carcinogenesis and prognosis of various tumours. Previous studies have shown their potential as biomarkers in oral squamous cell carcinoma ( OSCC ). Aiming to understand more clearly the function of MT s in OSCC we evaluated, for the first time, the gene expression profile of MT s in this neoplasm. Materials and results Tissue samples from 35 cases of tongue and/or floor of mouth OSCC , paired with their corresponding non‐neoplastic oral mucosa ( NNOM ), were retrieved (2007–09). All tissues were analysed for the following genes using TaqMan ® reverse transcription–quantitative polymerase chain reaction ( RT – qPCR ) assays: MT 1A , MT 1B , MT 1E , MT 1F , MT 1G , MT 1H , MT 1X , MT 2A , MT 3 and MT 4 . The expression of MT 1B and MT 1H was seldom detected in both OSCC and NNOM . A significant loss of MT 1A , MT 1X , MT 3 and MT 4 expression and gain of MT 1F expression was observed in OSCC , compared to NNOM . Cases with MT 1G down‐regulation exhibited the worst prognoses. The up‐regulation of MT 1X was restricted to non‐metastatic cases, whereas up‐regulation of MT 3 was related to cases with lymph node metastasis. Conclusions Metallothionein mRNA expression is altered significantly in oral squamous cell carcinomas. The expression of MT 1G , MT 1X and MT 3 may aid in the prognostic discrimination of OSCC cases.