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.

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.