Rethinking the Evolutionary Origin, Function, and Treatment of Cancer

Despite remarkable progress in basic oncology, practical results remain unsatisfactory. This discrepancy is partly due to the exclusive focus on processes within the cancer cell, which results in a lack of recognition of cancer as a systemic disease. It is evident that a wise balance is needed between two alternative methodological approaches: reductionism, which would break down complex phenomena into smaller units to be studied separately, and holism, which emphasizes the study of complex systems as integrated wholes. A consistent holistic approach has so far led to the notion of cancer as a special organ, stimulating debate about its function and evolutionary significance. This article discusses the role of cancer as a mechanism of purifying selection of the gene pool, the correlation between hereditary and sporadic cancer, the cancer interactome, and the role of metastasis in a lethal outcome. It is also proposed that neutralizing the cancer interactome may be a novel treatment strategy.

The role of exosomes in tumor progression and metastasis (Review)

Tumor cells have developed various mechanisms in defense against applied treatment, which prevent their total elimination from an organism. One of the underestimated mechanisms of defense is secretion of highly specialized double-membrane structures called exosomes. They play a crucial role in the control of the local microenvironment and intracellular communication. It has been shown that the exosomes can be carriers of various proteins, lipids, miRNAs and mRNAs. There are extensive data concerning the influence and participation by exosomes in metastasis and cancer progression. It has been demonstrated that exosomes are involved in multidrug resistance mechanisms, radiation-induced bystander effect and epithelial-mesenchymal transition. Furthermore, exosomes are able to form a premetastatic niche and enable the escape of cancer cells from recognition by host immune cells. Moreover, exosomes are responsible for the formation of vessels. This indicates the significance of secreted extracellular vesicles in the development and prognosis of cancer. The aim of the present review is to briefly describe the role of exosomes in tumor biology.

Cancer research: a hurdle race

Cancer research has shifted in recent years from studying intracellular processes (identification of damaged genes and signaling pathways) to extracellular (hierarchy of tumor cells, cell transitions, clone competition) and tissue (interactions of a tumor with its environment) research. But then the next step seems to be logical: studying biochemistry of tumor-bearing organisms (namely, cancer-induced changes in cellular and tissue metabolism leading to the organism's death). These data can help to develop new methods of cancer treatment. This article discusses some of the challenges of contemporary oncology and possible ways to overcome them.