Altered Expression of Imprinted Genes in Squamous Cell Carcinoma of the Head and Neck.

BACKGROUND: Genomic imprinting is associated with many human diseases, including various types of cancers, however, no studies on gene imprinting are related to squamous cell carcinoma of the head and neck (SCCHN) directly.

MATERIALS AND METHODS: In this study, the expression of a panel of 15 imprinted genes in cancerous and non-cancerous tissues from 73 patients with SCCHN were investigated.

RESULTS: Altered expression of carboxypeptidase A4 (CPA4); protein phosphatase 1 regulatory subunit 9A (PPP1R9A); H19, imprinted maternally expressed transcript (non-protein coding) (H19); paternally expressed gene 3 antisense RNA 1 (PEG3-AS1); retrotransposon-like 1 (RTL1), insulin-like growth factor 2 (IGF2); solute carrier family 22 member 3 (SLC22A3); and gamma-aminobutyric acid type A receptor beta3 subunit (GABRB3) was observed. Down-regulation of PPP1R9A (p<0.05) and GABRB3 (p<0.05) was correlated with more advanced cancer stages. Down-regulation of PEG3-AS1 (p<0.05) and GABRB3 (p<0.01) was correlated with lymph node metastasis. Poor survival was related to higher expression of CPA4 (p<0.01) and lower expression of PEG3-AS1 (p<0.05) and IGF2 (p<0.05). Chemotherapy was also found to have an impact on the expression of imprinted genes.

CONCLUSION: Loss of imprinting is involved in tumorigenesis of SCCHN.