Cancer Shifting Our Perception by Sayer Ji via Pathways Magazine PART II A PREHISTORIC DEFFENSE MECHANISM A brilliant new theory, introduced by Arizona State University scientist Paul Davies and Australian National University scientist Charles Lineweaver, sheds much-needed light on the true nature of cancer. According to Davies, Cancer is not a random bunch of selfish rogue cells behaving badly, but a highly-efficient pre-programmed response to stress, honed by a long period of evolution. In their seminal paper, titled, Cancer tumors as Metazoa 1.O: Tapping genes of ancient ancestors, Davies and Lineweaver propose that cancer is an evolutionary throwback, drawing from a genetic toolkit at least a billion years old, and which still lies buried-normally dormant-deep within the genome of our cells. Davies calls this subterranean genetic layer Metazoa 1.O, and it contains pathways and programs that were once indispensable for our ancient cellular predecessors and their proto-communities to survive in a radically different environment. Without the highly differentiated cells and specialized organs of higher multicellular/animal life (what Davies calls Metazoa 2.O), cells with the genetics of Metazoa 1.O would have favored traits that enabled them to survive direct contact with what was a much different and harsher (to us) environment. For example, 1 billion years ago atmospheric oxygen was exceptionally low, since photosynthesis has not yet evolved to produce an abundant supply. This means that cellular life at the time would have had to learn to thrive in a low- or no-oxygen environment, which is exactly what cancer cells do, using aerobic glycolysis for energy instead of oxidative phosphorylation. Davies and Lineweaver summarize their view as follows: The genes of cellular cooperation that evolved with multicellularity (animal life) about billion years ago are the same genes that malfunction to cause cancer. We hypothesize that cancer is an atavistic condition that occurs when genetic or epigenetic malfunction unlocks an ancient toolkit of pre-existing adaptations, re-establishing the dominance of an earlier layer of genes that controlled loose-knit colonies of only partially differentiated cells, similar to tumors. The existence of such a toolkit implies that the progress of the neoplasm (cancer) in the host organism differs distinctively from normal Darwinian evolution. Instead of viewing the hallmark trait of cancer, namely incessant proliferation, as a newly evolved trait spurned by random mutations, it would considered the default state of the cell, having been developed a billion years ago when not dying would have been the first priority. Remember, this ancestral assemblage of cells would not have had the differentiation of cell type and specialization of tissue associated with higher animals-skin, hair claws, etc.- with which to protect itself against the environment. Damage to the skin in animals, for instance, results in the rapid death and sloughing off these extra cells, to be replaced by new healthy ones. A still barely multicellular entity would not have this luxury, and would entrench itself within genetic traits associated with resilience-the ability to resist all manner of environmental assault-and would express a highly selfish form of behavior we now consider a fundamental property of cancer. If #cancer is an ancient survival program unmasked, this does not mean that the mutation theory does not still hold some truth. Genetic damage and mutations do in fact contribute to cancer, but rather than view them as causing the complex set of behaviors associated with cancer, they unmask an atavism, an already existent set of genetic programs. For instance, we know of more than 100 oncogenes that exist within our #DNA which we share with a vast array of different species, including the fruit fly. This indicates how ancient (at least 600 million years old) and universal they are (found in most multicellular organisms). Numerous studies confirm that #dinosaurs had tumors. These cancer-promoting genes are normally suppressed by more recently evolved #genes (Metazoa 2.O), such as tumor-suppressor genes, but when enough damage to the more recently evolved genetic overlay occurs, the system goes into safe mode and the older occurs, genetic pathways (Metazoa 1.O) are activated once more. Within the horizon of this new way of thinking, cancer can no longer be viewed as some predestined genetic time bomb setting itself off within us, nor simply a byproduct of cumulative exposures to genotoxic substances, alone. Rather, cancer is an ancient survival response to an increasingly #toxic #environment, an increasingly unnatural #diet and compromised immune function. These cells have learned to survive the constant abuse, and have flipped into survival mode, which is self-centered, hyper-proliferative (constant self-repair/replication) and aggressive (#metastatic). In other words, what does not kill them makes them stronger... ...TO BE CONTINUED...
Posted on: Thu, 05 Jun 2014 12:27:20 +0000