Evaluation of CYP1B1, oxidative stress and phase II detoxification enzyme status in oral cancer progression model.

Background: Tobacco is one of the main etiological factors for oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMD). CYP1B1 is an enzyme which plays a major role in the phase I detoxification of tobacco, the byproducts of which are subsequently detoxified by phase II enzymes Glutathione S Transferase (GST). We attempted to evaluate the L432V polymorphism and tissue expression of CYP1B1, along with the oxidant-antioxidant status in OSCC progression model. Method: ology: Tissue biopsies and blood samples were collected from the subjects; L432V polymorphism was evaluated by TaqMan RT-PCR, immunohistochemistry was performed on the tissue sample using CYP1B1 polyclonal primary antibody and Allred quick scoring system was used to evaluate the stained slides. Malonaldehyde (MDA) and GST activity were measured spectrophotometrically to assess oxidative-antioxidative status. Results: When the L432V polymorphism was analyzed, it was observed that in oral epithelial dysplasia (OED) and OSCC, CG was more common than GG genotype. Highest mean Allred score was observed in tobacco users (6.27), highest GST activity was seen in oral epithelial dysplasia (5.006 U/ml) and highest MDA activity was observed in OSCC (1553.94 nm/ml). Conclusion: Tobacco users with CG and GG genotypes are at equal risk of developing oral epithelial dysplasia or OSCC and L432V polymorphism does not appear to increase the risk of malignant transformation in oral epithelial dysplasia. Moreover, tobacco users with GG genotype and tissue expression of CYP1B1 may be at a greater risk of oxidative damage.

Deciphering the "Collagen code" in tumor progression.

Invasion and metastasis are the fundamental properties of tumor biology and the root causes of cancer death. With the elucidation of genetic and epigenetic mechanisms, it has been postulated that cancer is a disease of imbalance. It is not merely a disease of tumor cells but also the body's mismanagement of those tumor cells. Tumor microenvironment plays an important role in tumor progression via the co-evolution of tumor cells and tumor stroma. Hence, exploring the complex mechanisms of tumor progression from perspectives of tumor stroma has become a new frontier. The major component of tumor stroma, the extracellular matrix (ECM), acts as a key regulator of cell and tissue function. Conventionally, the role of ECM was considered primarily as a physical scaffold that binds cells and tissues together. However, recent studies revealed the biochemical and biophysical signaling properties of the ECM as well that affect cell adhesion and migration, tissue morphogenesis and repair, and angiogenesis and cancer. The most abundant constituent of ECM, collagen, accounts for the major function of ECM, which can be associated with increased malignancy. The present review summarizes the dynamic interplay between collagen and tumor cells. It focuses on changes in physicochemical-biological properties of collagen. A new paradigm has been formulated that collagen can no more be considered playing a passive role over which tumor progression and metastasis takes place. Rather, its active role in the promotion of tumor progression and metastasis should be explored.

Nerve sheath myxoma of the oral cavity: a distinct entity.

Nerve sheath myxomas (NSM) are uncommon benign tumours of nerve sheath origin. These tumours are most often located in the dermis and subcutaneous tissue of the head and neck region, but less frequently can also involve extracutaneous sites but they are rarely seen in the oral cavity. Many authors consider nerve sheath myxoma and neurothekeoma to be variants of the same tumour, though currently it has been demonstrated that both the lesions are distinct entities with different origins and unique morphological features. Herein we report a case of Nerve Sheath Myxoma on the palatal gingiva.

Intraosseous Neurofibroma of the Mandible: A Case Report and Review of Literature.

Neurofibroma (NF) is a benign tumor of the peripheral nervous system. Head and neck NF are generally located in the soft tissue. The tumour is rarely seen intraosseously and most commonly such tumours are seen as solitary lesions, rather than part of neurofibromatosis. The following report describes a case of an intraosseous neurofibroma in a 45-year-old male located in the left posterior mandible. The diagnosis was made based on the clinical findings, radio graphical features, histopathology, and immunohistochemistry. A literature review has been done on intraosseuos neurofibromas located in the jaws, with a discussion on the possible differential diagnosis.

Cd34 and Mast Cell Analysis in Normal Oral Mucosa and Different Grades of Oral Squamous Cell Carcinoma: A Comparative Study.

BACKGROUND: Oral Squamous Cell Carcinoma (OSCC) remains a serious health problem worldwide. Prognosis of OSCC is poor and long term survival rate still remains below 50%. Angiogenesis or neovascularisation plays an important role in tumour progression and metastasis. Mast cells have been implicated in promoting tumour angiogenesis, especially of digestive tract, little is known in OSCC. AIM & OBJECTIVE: To study the correlation between blood vessel density (BVD) and mast cell density (MCD) in different grades of OSCC. METHODS: Thirty eight paraffin blocks of different grades of OSCC were retrieved from the department and sections were stained with CD34 followed by counterstaining with toluidine blue. The slides were then analysed using Leica Software (Version 4.5). RESULTS: Mean BVD and MCD were found to be increased in OSCC as compared to normal mucosa. Increase in BVD with co-current increase in MCD was also observed in different grades of OSCC. CONCLUSION: From our study, it was concluded that, mast cells play a major role in promoting tumour angiogenesis. But, as the grade of the tumour increases, other angiogenic factors may play a more significant role than mast cells in tumour progression.

Teratoid cyst of the oral cavity: A rare entity.

The teratoid cyst is a rare variant of the dermoid cyst which seldom occurs in the oral cavity. If seen, they generally present as slow growing cysts of the floor of mouth, reported commonly in the 2(nd) and 3(rd) decade of life in males. Histopathologically, dermoid cyst is classified as epidermoid cyst, true dermoid cyst and teratoid cyst depending on the presence of adnexal structures and derivatives of all three germ layers. Herewith we report a rare case of teratoid cyst of the floor of the mouth, in a 2-year-old female child, which was present since birth.