Cancer also accelerates aging…
Researchers at the Kimmel Cancer Center, part of Jefferson University, working under the leadership of Professor Michael P. Lisanti, have received important data on another mechanism by which malignant tumors ensure their growth and metastasis and how this growth can be stopped. It turned out that cancer cells accelerate the aging of the cells of the connective tissues surrounding them, causing inflammation, which provides the tumor with the "fuel" necessary for rapid growth and metastasis.
Earlier, the Lizanti group found that malignant tumors induce autophagy (self-destruction) of neighboring connective tissue cells and somehow use this process for their own nutrition and growth.
To study the mechanisms of tumor parasitization on healthy tissues, scientists used both preclinical models and tumors of patients with breast cancer. They found that as the body ages, it becomes more susceptible to this mechanism, which explains the increased risk of developing tumors in old age.
The results of an extensive study conducted by the authors are published in the June issue of the journal Cell Cycle in three separate articles: Molecular profiling of a lethal tumor microenvironment, as defined by stromal caveolin-1 status in breast cancers, Evidence for a stromal-epithelial “lactate shuttle” in human tumors: MCT4 is a marker of oxidative stress in cancer-associated fibroblasts and Cytokine production and inflammation drive autophagy in the tumor microenvironment : Role of stromal caveolin-1 as a key regulator .
The study of the molecular profiles of connective tissue cells surrounding lethal breast tumors has shown that the expression of hundreds of genes in these cells is comparable to the pattern occurring in normal aging and Alzheimer's disease. The authors claim that such changes are caused by signaling substances secreted by cells of a metastatic tumor.
The authors also found that the tumor uses the mechanism of the so-called "lactate shuttle" to move lactate (lactic acid) from connective tissue into malignant cells. This mechanism, which involves two molecular carriers of monocarboxylates (mono-carboxylate transporters), MCT1 and MCT4, was discovered 100 years ago in muscles and 15 years ago in brain tissue. When this "shuttle" is launched, cells of one type are fed at the expense of cells of another type. The researchers claim that in this case, tumor cells develop dependence on a "treat" in the form of lactate, to activate the production of which they trigger aging and inflammation processes in connective tissue cells.
In addition, the researchers proved that MCT4 is a biomarker of oxidative inflammation in fibroblasts surrounding cancerous tumors and suppression of its expression can become a powerful new method of antitumor therapy.
According to Lisanti, if cancer causes accelerated aging of the connective tissue associated with it, it is possible that the condition of cancer patients can be significantly improved with therapy with strong antioxidants and anti-inflammatory drugs.
Evgeniya Ryabtseva
Portal "Eternal youth" www.vechnayamolodost.ru
01.06.2011