ABSTRACT
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.
Subject(s)
Humans , Carcinogenesis , Carcinoma, Squamous Cell , Cell Proliferation , DNA , Gene Expression , Head , Lymph Nodes , Mucous Membrane , Neck , Neoplasm Metastasis , Nucleoproteins , Prognosis , RNA, MessengerABSTRACT
PURPOSE: The precise mechanisms of tumorigenesis of breast cancer remains unknown in spite of major efforts. Recent studies have shown that High Mobility Group I (Y) Proteins [HMGI(Y)] have an important role in the regulation of chromatin structure and function, and that HMGI(Y) protein expression is generally correlated with a malignant phenotype. This study was undertaken to define the relationship of the HMGI(Y) protein expression between malignant breast tissue and non-malignant breast tissue in human, and clinico- pathologic findings were reviewed for this purpose. METHODS: Using Reverse Transcription-Polymerase Chain Reaction (RT-PCR) for HMGI(Y) with beta-actin, this study demonstrated the expression of HMGI(Y). The p53, ER, and PR. were defined by immunohistochemical staining. RESULTS: The HMGI(Y) expression was increased in the malignant tissue (90%), than in benign (76.9%) or normal (65%) tissue (p=0.031). As for the invasive ductal cancers, there was no difference between the HMGI(Y) expression and histopathologic parameters. CONCLUSION: These results suggest that the HMGI(Y) expression may be of little pathogenetic prognostic importance in human breast cancer.
Subject(s)
Humans , Actins , Breast Neoplasms , Breast , Carcinogenesis , Chromatin , PhenotypeABSTRACT
PURPOSE: The precise mechanisms of tumorigenesis of breast cancer remains unknown in spite of major efforts. Recent studies have shown that High Mobility Group I (Y) Proteins [HMGI(Y)] have an important role in the regulation of chromatin structure and function, and that HMGI(Y) protein expression is generally correlated with a malignant phenotype. This study was undertaken to define the relationship of the HMGI(Y) protein expression between malignant breast tissue and non-malignant breast tissue in human, and clinico- pathologic findings were reviewed for this purpose. METHODS: Using Reverse Transcription-Polymerase Chain Reaction (RT-PCR) for HMGI(Y) with beta-actin, this study demonstrated the expression of HMGI(Y). The p53, ER, and PR. were defined by immunohistochemical staining. RESULTS: The HMGI(Y) expression was increased in the malignant tissue (90%), than in benign (76.9%) or normal (65%) tissue (p=0.031). As for the invasive ductal cancers, there was no difference between the HMGI(Y) expression and histopathologic parameters. CONCLUSION: These results suggest that the HMGI(Y) expression may be of little pathogenetic prognostic importance in human breast cancer.
Subject(s)
Humans , Actins , Breast Neoplasms , Breast , Carcinogenesis , Chromatin , PhenotypeABSTRACT
High Mobility Group I(HMG-I) proteins are nuclear proteins that are required for induction of the human IFN-beta gene by virus and for the regulation of the tumor necrosis-beta factor and rRNA genes. Proteins I and Y result from alternative splicing of a single functional gene named HMGI(Y). In several studies, elevated expressions of the HMGI proteins (HMGI, HMGY, and HMGI-C) have been used as markers in thyroid cancer, but not in adenomas, goiters, and normal thyroid tissues and cells. Here, we try to demonstrate the elevated expression of the HMGI(Y) proteins in thyroid carcinomas by using semi-quantified RT-PCR (Reverse Transcription and Polymerase Chain Reaction). In cases of thyroid carcinomas 4 of 5(80%) were positive, in 10 cases of adenomas, goiters, and normal thyroid tissues, 1(10%) was positive. These results suggest that the semi-quantified RT-PCR is useful preoperative diagnostic tool for differentiating thyroid tumors.