Analysis of metallothionein and vimentin immunoreactivity in pharyngeal squamous cell carcinoma and its microenvironment

Metallothionein (MT) has been shown to have pro-proliferative anti-apoptotic activity and to be involved in microenvironment remodeling. The aim of this study has been to determine whether the changes in MT and vimentin immunoreactivity observed in cancer and its microenvironment are related to the local spread of the disease. The immunoreactivity levels of both MT and vimentin were evaluated together with CD56 and CD57 antigens in 49 tissue samples taken from patients with squamous cell carcinoma originating from the palatine tonsils and in 20 tissue samples derived from patients with chronic tonsillitis (the reference group). MT immunoreactivity levels were statistically significantly higher in the tissue samples from squamous cell carcinoma than in those of the reference group and also higher in the squamous cell carcinoma samples compared with the stromal samples. Moreover, stromal fibroblasts exhibited high vimentin and MT immunoreactivity levels. Statistically significantly higher MT immunoreactivity levels within the tumor cells were identified in patients with the presence of lymph node metastases in contrast to those patients without such metastases. Vimentin was detected in both the tumor and the stromal tissue samples and presented an interesting pattern of staining strongly expressed within the stroma and the septal architecture of the tumor. The number of CD56- and CD57-positive lymphocytes identified in tissue samples both from squamous cell carcinoma and from the stroma was statistically significantly lower than that in the reference group. MT expression by tumor cells is thus associated with an aggressive phenotype of the tumor and the ability to create metastases

The evaluation of resistance to apoptosis in head and neck cancer healthy stroma

Introduction: Metallothionein (MT) is a low-molecular weight metal-binding protein with functional roles in cell growth, repair and differentiation. MT is considered as a protective and an anti-apoptotic protein. The aim of our study was to evaluate the MT expression in head and neck squamous cells carcinoma histologically healthy adjacent tissue. Materials and Methods: We have sampled 30 tissue samples derived from head and neck cancers and 30 samples of their clear surgical margins. Antibody recognizing MT-1 was used for immunohistochemical analysis. Results: MT expression was revealed in 85,7% of head and neck cancers and was found in all tumor adjacent tissues. Statistically significantly higher MT expression was found in tumor adjacent tissue than in cancer tissue in cases with the presence of lymph node metastases. Generally, stroma responded to the presence of cancer by the expression of MT, even in tissues which normally did not express MT. Also, stroma adjacent to MT negative cancers expressed MT. Conclusions: MT contributes in delaying cells from apoptosis, the effect of apoptotic factors released from cancerous tissues in our study might be counterbalanced increased synthesis of MT adjacent healthy tissues. MT might be a normal or protective reaction of healthy adjacent tissue