Hello John

What is fascinating about cancer is the way in which it adopts methods to survive in the human body. The immune system of the human body is one of the unique systems that plays a major role in defending the body from invaders. But cancer cells have managed to be one step ahead by tricking the immune system and evading its detection. It causes mutations in several genes which are vital for growth and maintenance of normal cells. Take for example p53 gene which is termed as the “Guardian of the Genome”. It is such an important gene which is mutated in many types of cancer. Then we have the other tumor suppressor genes and DNA repair genes which help to keep cancer at bay by performing their usual function, but they too are not spared by the cancer cells.

The way cancer cells spread their tentacles not just restricting themselves to the localized site is also fascinating. The way they make their route clear from the primary site into the blood stream or the lymphatic system and then into the secondary site is commendable. This process is called metastasis.

Cancer is one of the complicated pathological condition. The ways adopted by the cancer cells to survive are so tricky that science indeed must work hard to find a cure for cancer. It is a mystery how these cancerous cells affect various signaling pathways. Regulation of cell proliferation by Ras-ERK and PI3K-Akt pathways are disrupted by cancer cells making it more constitutively hyperactive thereby causing excess proliferation. The other pathways that affect cell death, cell fate and cell motility are also distorted by cancer cells thereby facilitating cancer progression. Chemotherapeutic drugs which are used to treat cancer are now turning ineffective because of resistance. Drug resistance is become a major problem in treating cancer patients. These are some enigmas if not all associated with cancer.

You need to know much more about cancer and its mechanism. I hope I have been able to explain some part of it.

Best Wishes.

Malcolm

Fascinating thing about cancer is that how cancer cell move to other parts of body and damage healthy cells, making them sick and still we are unable to find a vaccine or preventive medicine.

What is missing in the previous description is that cancer occurs due to stepwise

alterations in many cell cycle regulatory and signalling pathways through actual gene mutation but much more commonly the deviation towards malignant cancer occurs due to inappropriate epigenetic silencing (epimutation) of the genes in and affecting these pathways.

Tissues, and thus cells, develop and maintain their identity by loosening the DNA "packaging proteins" around genes essential for that particular tissue while at the same time silencing (read as the packaging proteins making the genes inaccessible to transcription and thus function) all genes that are not required for that cell types function. All cells have all the DNA required for all tissues in the body but by silencing those genes that are not required for a particular tissue type the cell both acquires and maintains identity and function.

These regulatory pathways are susceptible to aberrant epigenetic regulation over time (affected by heredity, foods, chemical exposure and other environmental factors) which can either silence or aberrantly activate many genes related to cell cycle control, eventually allowing cancer cells to replicate without restriction. This state resembles that of a stem cell which can divide nonstop and it is now known that these "cancer stem cells" develop the mobility required to escape from the tissue of origin only to go about abnormal tissue development (growing a tumor) in distant sites, resulting in metastasis (spread of cancer) and eventually death.

From a surgeons view point Cancers are still hard nuts to crack ... And cancer surgeries performed scientifically and timely at present is the only fascinating treatment ... the science of vaccine and genetic level preventions are all futuristic goals ...