Immunohistochemical evaluation of actin expression in basal cell carcinoma and oral squamous cell carcinoma

Abstract

Background: Basal cell carcinomas (BCCs) are generally slow-growing tumours. T hey have been classified as aggressive (A-BCC) and non-aggressive (NA-BCC).Oral squamous cell carcinoma (OSCC) is a major cause of cancer morbidity worldwide, this is due to the characteristics of invasion. The microenviroment or stroma of neoplastic tissues plays an active role in tumour progression. Trans-differentiation of fibroblast to myofibroblast is a crucial and early event in tumourigensis. Alterations of contractile tension generated by the actin–myosin complex are of cen t ral importance in the development of the phenotype of morphologically transformed neoplastic cells with invasive behavior. Actin is the predominant component of contractile microfillament and it may be associated with increase contractility and invasiveness of tumour cells. Objective: This study aimed to investigate the presence of myofibroblasts in the st roma of basal cell carcinoma and oral squamous cell carcinom a, evaluated by the immunohistochemical expression of actin. Materials and method s: Twenty four formalin –fixed, paraffin -embedded tissue blocks (14 cases basal cell carcinoma, 10 cases oral squamous cell car cinoma) were included in this study. An immunohistochemical a nalysis was performed using anti alpha - smooth muscle actin (α- SMA) monoclonal antibody. Results: All cases of OSCC, BCC and normal oral mucosa showed positive reacti on of actin in the smooth muscles surrounding blood and lymphatic vessels. All OSCC and BCC cases demonstrated str omal immunostaining for actin with different scores indicati ng the presence of myofibroblasts. There were no myofibroblasts in the stroma of normal mucosa indicated by negative α- SMA expr ession in it. Conclusions: Immunohi stochemical examination of BCC and OSCC for this marker may help clinicians in predicting tumour behaviour.