Asian Pacifc Journal of Cancer Prevention, Vol 14, 2013 3987 DOI:http://dx.doi.org/10.7314/APJCP.2013.14.6.3987 What is a Cancer Cell? Why does it Metastasize? Asian Pacifc J Cancer Prev, 14 (6), 3987-3989 Introduction Cancer is a dreaded disease and metastasis is usually the ultimate cause of death. In our previous article (Hegde et al., 2008) we had refected on the origin of life in oxygen less atmosphere, the opposite complementary nature of plant and animal forms and why oxygen depleted plant forms, the vegetarian food, richer in antioxidants are more supportive to life. In this article we wish to extend the philosophy further particularly in the light of some recent fndings what is a cancer cell and why metastasis? According to second law of thermodynamics cosmic force drives the universe towards increase in entropy. Life is order and death is disorder. Hence life is a miracle and aging, disease (cancer) and death is a certainty. The very act of respiration to derive energy from the food for sustaining life inevitably produces about 2% reactive oxygen radicals. These free radicals can attack and damage almost any vital molecules and structures in our body, irreversibly and permanently causing disease and death. So also these very free radicals can attack the DNA and transform normal cell to a cancerous cell. Obviously higher antioxidant levels within the cell can prevent the carcinogenesis. It may also be noted here that our food habit and the non- availability of vital nutrients and good amounts of antioxidants in the food can be the major cause of cancer. As per the new Triage theory put up by Ames (2010) ‘Nature always favors short term survival over long term survival’. It therefore follows that in the absence of adequate supply of essential nutrients, the vital processes such as energy production and protein synthesis and 1 Center for Innovation in Nutrition, Health and Disease, Interactive Research School of Health Affairs (IRSHA), Bharati Vidyapeeth University, 2 Department of Surgery, Medical College, Bharati Hospital, Bharati Vidyapeeth, Pune, India *For correspondence: mahabaleshwarh@yahoo.com Abstract This is a commentary on what a cancer cell is and why cancer cells metastasize. Normal cell get transformed to a cancer cell, with excessive production of free radicals that mutate the DNA of a normal cell. The immortality and malignant stage of transformed cell is maintained by higher GSH levels. With the faster rate of proliferation, when the cancer cell fnds the place of origin is not conducive to its further growth, cancer cell chooses to take the metastatic course. We argue that if we can stop the exit of cancer cell from place of origin, cancer spread can be stopped or even cured. Keywords: Metastasis - epithelial to mesenchymal transition (EMT) - matrix metalloproteinases - intravasation COMMENTARY What is a Cancer Cell? Why does it Metastasize? Mahabaleshwar Vishnu Hegde 1 *, Aniket Vijay Mali 1 , Shubha Sandeep Chandorkar 2 the vital organs such as heart are provided nutrients on priority and the processes such as DNA repair which does not pose immediate threat to life, may get a setback. The inability to effectively repair the DNA in these cells may become susceptible to cancerous transformation. It may not be surprising therefore heart cancer is very rare, almost unheard of. Our body is provided with antioxidant defense mechanism through the production of proteins such as superoxide dismutase, glutathione peroxidase, catalase etc that can effectively scavenge the free radicals. There are also low molecular weight antioxidants that mainly come from the food that can regulate the redox potential of a cell with the help of glutathione, the ultimate antioxidant within the cell. There is continuous battle between the oxidative stress produced by the free radical load and antioxidant defense in every cell of our body. Healthy levels of redox potentials are maintained by GSH: GSSG (reduced and oxidized forms of glutathione) the redox buffer by normal cells (Townsend et al., 2003). Unhealthy cells have lower levels of GSH which further decrease resulting in cell death. So also increase in GSH: GSSG higher than normal cell is necessary to transform normal cell to cancerous cell and confer the immortal status to cancer cell. We have shown that (Hegde et al., 2010) oral cancerous cells have higher GSH possibly to maintain malignancy and the precancerous cells even have higher levels of GSH, than cancerous cells perhaps to prevent them to become malignant. Cancer cell however is an abnormal cell which is regarded as immortal, the cell that has forgotten to die. How this extraordinary ability is acquired by a cancer cell would be a very pertinent question to ask and seek the