RESUMO
BACKGROUND AND OBJECTIVES: Expression of HMGI(Y), a nucleoprotein that binds to A/T rich sequences in the minor groove of the DNA helix, is observed in neoplastically transformed cells but not in normal cells. We have analyzed HMGI(Y) expression in the head and neck squamous cell carcinoma and evaluated its clinicopathologic significance. MATERIALS AND METHODS: HMGI(Y) mRNA was measured by RT-PCR and immunohistochemical staining for HMGI(Y) was performed in the head and neck squamous cell carcinoma. RESULTS: Expression of HMGI(Y) by immunohistochemical staining was observed in 35 of 40 (87.5%) head and neck squamous cell carcinoma samples, whereas normal mucosa and/or the mucosa adjacent to the tumor tissue showed negative or weakly positive staining (p<0.05). Semiquantification of HMGI(Y) by RT-PCR were 2.98+/-2.24 in cancer and 0.47+/-0.25 in normal tissue (p<0.001). High expression of HMGI(Y) was observed in well differentiated group and recurrent cases compared to the less differentiated group and/or non-recurrent cases (p<0.05). But no significant correlation was observed between the levels of HMGI(Y) expression and other clinical factors such as stage, tumor size and cervical lymph node metastasis. CONCLUSION: We think that the HMGI(Y) gene plays some roles in carcinogenesis and cellular proliferation of the head and neck squamous cell carcinoma. HMGI(Y) gene can be used as a cancer marker, but the correlation between the gene expression and the prognosis of the cancer patient should be proved in the future studies.
Assuntos
Humanos , Carcinogênese , Carcinoma de Células Escamosas , Proliferação de Células , DNA , Expressão Gênica , Cabeça , Linfonodos , Mucosa , Pescoço , Metástase Neoplásica , Nucleoproteínas , Prognóstico , RNA MensageiroRESUMO
BACKGROUND: Transforming growth factor(TGF-alpha) is a polypeptide which is structurally related to epidermal growth factor(EGF) and binds to the epidermal growth factor receptor(EGFR). TGF-alpha utilizes EGFR to increase the activation of tyrosine kinase to involve in signal transduction of cellular growth. TGF-alpha synthesis occurs in a variety of neoplastic cells. p53 is a tumor-suppressor gene. There is a strong corrleation between immunohistochemical p53 positivity and p53 mutations in lung and laryngeal carcinoma. PCNA is expressed by cycling cells in late G1, S and G2 phase, and may be used to indicate the degree of cellular proliferation. OBJECTIVES: To evaluate whether TGF-alpha, p53 and PCNA can be used as an indicator to malignant transformation of dysplasia in larynx or not. MATERIALS AND METHODS: The authors investigated the TGF-alpha score, p53 immunoreactivity and PCNA proliferating index by immunohistochemical staining in 30 laryngeal dysplasia from 1992 to 1995. RESULTS: Dysplasia with malignant transformation showed values of 5.46 for TGF-alpha, 29.2 for PCNA proliferating index and 37.5 for p53 immunoreactivity. Dysplasia without malignant transformation showed values of 1.88 for TGF-alpha, 8.6 for PCNA proliferating index and 4.5 for p53 immunoreactivity. Conclusions: The results suggest that TGF-alpha, p53 and PCNA could be an useful indicator to predict the progression of laryngeal dysplasia.