Diagnostic potential of Type VII Collagen during oral carcinogenesis

Abstract Type VII collagen (Col7) is a major component of anchoring fibrils. Col7 plays a role in tumor development and aggressiveness of cutaneous squamous cell carcinoma of recessive dystrophic epidermolysis bullosa. However, the role of Col7 in oral squamous cell carcinoma (OSCC) and oral leukoplakia (OL) remains largely unknown. Objective To elucidate the role of Col7 and its diagnostic potential during oral carcinogenesis. Methodology Col7 expression was immunohistochemically studied in 254 samples, including normal oral mucosa (NM), OL without dysplasia, OL with dysplasia, and OSCC. The correlation between Col7 expression and clinicopathologic parameters of OSCC was also determined. Results Col7 was present as a linear deposit at the basement membrane of NM, OL without dysplasia and OL with dysplasia, and at the tumor-stromal junction around tumor islands in OSCC. Discontinuity of expression was frequently observed in OL with dysplasia and OSCC. OSCC had the significantly lowest Col7 expression (p<0.0001). Compared with OL without dysplasia, OL with dysplasia showed significantly reduced Col7 expression. Patients in clinical stage 4 with positive nodes had low Col7 expression compared with those in clinical stage 1 and negative nodes, respectively. Conclusion Loss of Col7 is associated with tumorigenesis and aggressiveness in OSCC. A significantly reduced Col7 expression in OSCC implies that Col7 may be a useful marker for diagnosis and therapeutic targets.

Detection of human papillomavirus in oral squamous cell carcinoma, leukoplakia and lichen planus in Thai patients.

Although tobacco, alcohol abuse and betel nut chewing habit are well recognized risk factors for oral squamous cell carcinoma (OSCC), there is evidence to indicate that human papillomavirus (HPV) may also play some inducing role. The purpose of this study was to investigate the presence of HPV in Thai patients with oral squamous cell carcinoma, leukoplakia and lichen planus using the polymerase chain reaction (PCR). Biopsies of oral squamous cell carcinoma, leukoplakia and lichen planus were obtained from 65 patients, 15 males and 50 females, aged between 30- 88 years old. Extracted DNA was evaluated for HPV infections by PCR analysis using consensus primers specific for L1 region of HPV. Only one sample (1.54%) was positive, suggesting that HPV may not play an important role in this group of Thai patients.