In a groundbreaking study conducted by researchers from Singapore and the UK, a previously unknown mechanism for inactivating genes that suppress tumor formation has been discovered. This mechanism sheds light on why cancer risk is associated with an unhealthy diet and unmanaged metabolic conditions like diabetes. The study utilized mouse models, human tissue, and lab-grown human breast organoids to investigate how changes in glucose metabolism can enable cancer growth by transiently disabling a gene known as BRCA2.
The findings from this study challenge the long-standing ‘two-hit’ paradigm proposed by Knudson in 1971, which suggests that both copies of a tumor suppressor gene must be permanently inactivated for cancer to develop. Interestingly, mutations in one of the two BRCA2 genes have been implicated in various cancers. Mice and human cells with this mutation do not exhibit the expected signs of genetic instability seen in cells with both copies of the gene mutated. While having only one copy of BRCA2 affected does not seem to cause significant issues in organ development or DNA repair in most tissues, these cells are more susceptible to environmental stresses that reduce BRCA2 protein levels, leading to functional impairments.
The study found that cells with a faulty copy of BRCA2 were more sensitive to methylglyoxal (MGO), a byproduct of glucose breakdown in the process of glycolysis. Glycolysis generates the majority of MGO in cells, which is typically regulated by a pair of enzymes to maintain minimal levels. However, in conditions like diabetes where MGO levels are elevated due to high blood sugar, harmful compounds that damage DNA and proteins can form. The researchers discovered that MGO can temporarily disable the tumor-suppressing functions of the BRCA2 protein, leading to mutations associated with cancer development.
The findings of this study have important implications for understanding the connection between glucose metabolism and cancer development. The temporary disabling of BRCA2 by MGO highlights how changes in glucose metabolism can contribute to the development and progression of cancer. This information may pave the way for strategies aimed at cancer prevention and early detection. The ability to detect MGO through a blood test for HbA1C could potentially serve as a marker for individuals at a higher risk of cancer due to poor diet or uncontrolled diabetes.
While the results of this study are significant, it is essential to acknowledge the limitations of the research, which primarily involved lab tests and small human tissue samples. The researchers emphasize the need for further studies using larger clinical trials or animal models to explore the potential links between dietary factors, diabetes, and other metabolic disorders in the context of cancer development. By conducting more extensive studies, a deeper understanding of how glucose metabolism influences cancer risk can be achieved.
The discovery of the link between glucose metabolism and cancer development represents a crucial step towards unraveling the complexities of cancer biology. The identification of MGO as a key player in disabling the tumor-suppressing functions of BRCA2 sheds light on the intricate interplay between metabolic pathways and cancer initiation. By continuing to investigate this mechanism, researchers can potentially uncover new avenues for cancer prevention and treatment strategies tailored to individual metabolic profiles.