Cancer Metabolism – A brief Overview

Cancer is second most leading cause of mortality, worldwide, after Cardiovascular diseases. There has been ongoing investigation to find more hallmarks of cancers. As reported on 2011 published article on hallmarks of Cancer by Hanahan and Weinberg, few more hallmarks have been reported within a ten year period. Among those newly discovered hallmarks, metabolism within cancer cells have been summarized.

The reason to focus on cancer metabolism is to find an effective treatment to cure a cancer patient. Apart from deregulation in protein expression in cancer cells, the malfunction of enzymes affects composition of metabolites and sustains cancer cell survival.

Three metabolic activity have so far been stated:


Transforming metabolism 
 Such activities helps cancer cells to progress from one form to other, i.e. from the genesis of cancer cells to a lump within local tissue to metastasis. One of them is Isocitrate dehydrogenase I and II (IDH I and II). Studies have reported the mutant form of IDH I and II in patients suffering from Glioblastoma Multiforme. The mutation within IDH has resulted accumulation of D-hydroxyglutarate (by catalysing α-ketoglutarate), thereby affecting expression of particular genes. 

Enhancing Metabolism 
The second type which are involved in sustaining survival of cancer cell. There are three major aspects of metabolism, within this category and will be discussed in separate article. But to briefly summarize: 1) Catabolic reactions: The breakdown of biomolecules to extract energy. Cancer cells depend on Glucose (the most famous being, the Warburg effect) and Glutamine for energy production (but depends of current state of the cell and the composition of microenvironment); 2) Anabolic reactions: The buildup of macromolecule from its monomers. Cancer cells depend on Protein, Fats and Nucleic Acids for its survival and growth, and; 3) Redox reaction: As cancer cells proliferate rapidly, it faces lack of oxygen and nutrients and so, it produces free radicals that damages cellular structure inside cancer cells. In order to protect themselves, cancer cells overexpress enzymes that neutralizes those radicals and prevents from damaging. 

Neutral Metabolism 
   The process doesn't affect on the growth and survival of cancer cells upon its inhibition. Enzymes like, Pyruvate Kinase B, is one of the example. Such molecules are necessary to be detected, in order to classify and exempt them for drug target.


In short, cancer metabolism plays one of the major part to find treatment because an altered metabolic pathway inside cancer cells determines other hallmark of cancer.