Telomerase activity detected in oral lichen planus by RNA in situ hybridisation: not a marker for malignant transformation

Abstract

Background: Oral lichen planus (OLP) is a chronic inflammatory condition. Clinically, it is characterised by the presence of a white lace-like lesion on the buccal mucosa, tongue, and gingivae, with erosions and ulceration. The World Health Organisation considers OLP to be a premalignant condition. Aims: To investigate expression of the telomerase RNA component (hTR) in OLP compared with normal control buccal mucosa and to assess the possibility of using hTR expression as a marker for malignant transformation in OLP. Methods: hTR expression was analysed in 40 cases of OLP and 18 normal control buccal mucosa samples using an RNA in situ hybridisation approach. Results: Strong hTR RNA expression was seen in the basal, suprabasal, and to a lesser extent in the upper epithelial layers in 36 of the 40 OLP lesions examined. Infiltrating subepithelial lymphocytes in OLP were also shown to express hTR RNA. Weak hTR RNA expression was seen in seven of the 18 normal control buccal mucosa specimens, with expression confined exclusively to the basal layer of the epithelium and absent in the suprabasal and upper layers. Conclusion: The telomerase RNA component hTR is found to be highly expressed in the epithelium of non-dysplastic OLP lesions. It is possible that this high expression is related to the increased cellular proliferation seen in OLP lesions rather than being an indicator of susceptibility to malignancy. Thus, hTR RNA expression may not be a suitable marker for predicting malignant transformation in OLP.

Salivary Interleukin‐6 and ‐8 in Patients With Oral Cancer and Patients With Chronic Oral Inflammatory Diseases

“…Although both CP and OLP are inflammatory diseases, it has been suggested that patients with OLP have a higher risk for developing OSCC based on clinical studies and case reports 38‐40 . However, research on several surrogate endpoints such as telomerase activity, P53, loss of heterozygosity, and cytogenetic abnormality did not show convincing or consistent evidence of premalignant potential as those found in epithelial dysplasia 41‐46 . Therefore, whether OLP is premalignant remains an unclear and controversial issue 38 .…”

Gene expression based evidence of innate immune response activation in the epithelium with oral lichen planus

“…Much of this work has focused on the T cells that invade the stroma. Primers were designed for q-RT-PCR analysis of CD14 18 , TLR1, TLR2, TLR6 19 , IL10 20 , HIF1 27 , hTR 28 , and TRPV1 29 . RNA for IL6 and IL8, two proteins that have been shown in multiple reports to be increased with OLP and to be synthesized by keratinocytes were also examined.…”

Chromosomal Numerical Aberrations in Oral Lichen Planus

“…To uncover some of the molecular genetic aberrations associated with OLP, investigators have used molecular and genetic methods such as loss of heterozygosity (LOH) (Zhang et al, 2000), chromosome in situ hybridization (Kim et al, 2001), p53 and c-erbB2 expression (Girod et al, 1994(Girod et al, , 1995Kilpi et al, 1996;Ogmundsdottir et al, 2002), and telomerase activity (O'Flatharta et al, 2002). However, none of these methods appears to provide definitive predictive information with regard to the malignant potential of a lesion diagnosed as OLP.…”