Expression pattern of Connexin 43 and Ki67 in oral squamous cell carcinoma

Abstract

Abstract: 

Oral squamous cell carcinoma (OSCC) is the eighth most prevalent cancer in the world, it has high morbidity and a low survival rate. The identification of biological markers allows increasing the sensitivity or specificity in the early detection or prognosis of malignancy in the population. The aim of this work was to determine the expression pattern of connexin 43 (Cx43) and Ki-67 in OSCC biopsies and control samples. Retrospective study of 24 samples of <18 years old, both genders, patients treated by spontaneous demand between 2014 and 2017 (approved by IRB Protocol No. 1379).OSCCs were diagnosed following the ICD10 classification code C00-C14. The controls were samples of normal gingival epithelium after dental extraction not associated with malignant or premalignant lesions.The expression levels of tumorigenic biomarkers were evaluated by immunohistochemical staining (IHQ). IHQ was analyzed in digital photomicrographs in 3 fields of 10-3 mm2using Image Pro Plus v13 software.Immunostainingwas classified according to the criteria of Tanaka et al. o y col. (2016) for Cx43 as low, medium and high expression, and positive-negative for Ki67 according to Schermaet al.(2017). The comparison between OSCC samples and controls was carried out using the Mann-Whitney test. The correlation was analyzed using the Spearman Coefficient (CS). A p-value <0.05 was set for statistical significance.Cx43 immunostaining was positive in 70% of control samples. Meanwhile, 90% of the cells presented low or null Cx43 immunostaining in OSCC samples (p = 0.0001). Ki67 labelling showed an elevated number of positive cells in CBCE samples concerning controls (p = 0.0007). Likely, in the process of malignant transformation, one of the first alterations in the epithelium of the buccal mucosa is the loss of Cx43 in the membrane, which modifies cell differentiation. In addition, the increase in cyclin Ki67 could be associated with the increase in cell proliferation. Both markers could be useful to identify the early stages of OSCC. (Work funded by FONCYT PICT2016–2358).