Immunohistochemical expression of kallikrein 7 in oral squamous cell carcinoma

BACKGROUND AND OBJECTIVES: The kallikrein (KLK) family of genes consists of 15 members, many of which are highly expressed in number of cancers compared to their normal parent tissues. KLK7 was initially characterized as an enzyme implicated in the degradation of intercellular cohesive structures in the stratum corneum of stratified squamous epithelia, preceding desquamation in the skin. It catalyzes the degradation of desmosomes in the outermost layer of skin and permits cell shedding to take place at the skin surface. Overexpression of KLK7 in tumor cells has been reported to significantly enhance the invasive potential in intracranial malignancies and ovarian cancer cells. Thus, KLK7 could contribute to the degradation of extracellular matrices in oral squamous cell carcinoma (OSCC) tissues, promoting invasion of neoplastic cells locally and facilitating metastasis to regional lymph nodes. The objectives of the present study were to compare the expression of KLK 7 in normal subjects and patients with OSCC, to correlate the expression of KLK 7 with respect to the clinical staging of OSCC and to evaluate the expression of KLK 7with respect to different histopathological grades of OSCC. MATERIALS AND METHODS: Thirty cases of OSCC were staged clinically and graded histopathologically. The immunohistochemical method was used to detect the expression of KLK 7 in OSCC. The scores obtained were documented and compared statistically. RESULTS: KLK 7 immunoreactivity was noticed in all cases of OSCC. A statistically significant difference was observed in immunoreactivity of KLK 7 between the normal and OSCC (P = 0.0001*) and in different histopathological grades (P = 0.0001*) and in different clinical stages (P = 0.0127*) of OSCC using Kruskal–Wallis analysis of variance test. CONCLUSION: The KLK 7 immunoexpression histopathologically increased from low grade to high grade and clinically from Stage 1 to Stage 4 in OSCC. Hence, increased expression of KLK 7 may be related to poor prognosis in patients with OSCC.