ABSTRACT
We analyzed mutation and expression status of human epidermal growth factor receptor 2 (Her2) in head and neck squamous cell carcinoma (HNSCC) using single strand conformation polymorphism (SSCP) mutation analysis and immunohistochemistry (IHC). Mutations were absent in all 85 cases. Out of 57 cases available for IHC, Her2 protein expression was negative (0) in 40 tumors (70%). Seventeen tumors (29.8%) expressed Her2, among these 13 tumors (22.8%) showed a weak (+1) expression and 4 (7%) showed a moderate expression (+2), none showed a strong (+3) expression. There was not a significant association between expression and any of the patients' clinical variables or prognosis. Our results suggest that Her2 may not be useful as a molecular target in HNSCC.
Subject(s)
Carcinoma, Squamous Cell/genetics , ErbB Receptors/genetics , Head and Neck Neoplasms/genetics , Carcinoma, Squamous Cell/mortality , DNA Mutational Analysis , Female , Head and Neck Neoplasms/mortality , Humans , Male , Middle Aged , MutationABSTRACT
BACKGROUND: Loss of heterozygosity (LOH) in the ING family members has been shown in head and neck squamous cell carcinoma (HNSCC) except for ING2. Like all the other members of ING family, ING2, which is located at chromosome 4q35.1, is a promising tumor suppressor gene (TSG). In this study, we performed LOH analysis of ING2 in HNSCC and compared it with clinicopathological variables. MATERIALS AND METHODS: We performed LOH analysis in DNAs from 80 paired of normal and HNSCC tissues, using a specifically designed microsatellite marker on chromosome 4q35.1, which detects allelic loss of ING2. TP53 mutation analysis and its relationship with ING2 chromosomal deletion were also performed in available 68 of the samples. The correlation between LOH status and clinicopathological characteristics was evaluated by using statistical methods. The overall survival (OS) and disease free survival (DFS) were also determined. RESULTS: LOH was detected in 54.6% (30/55) of the informative samples. Statistical significance was obtained between LOH and tumor (T) stage (P = 0.02), application of radiotherapy and chemotherapy. Positive node status (N) appeared to be the only independent prognostic factor for both OS (P = 0.031) and DFS (P = 0.044). CONCLUSIONS: Our study showed allelic loss of 4q35.1 in HNSCC. The high percentage of LOH suggests ING2 as a candidate TSG in HNSCC. High LOH frequency was statistically associated with advanced T stage, suggesting that ING2 LOH might occur in late stages during HNSCC progression.
