title: Cancer and the metastatic substrate.
abstract: Seventy percent of cancer patients have detectable metastases when they receive a diagnosis and 90% of cancer deaths result from metastases. These two facts emphasise the urgency for research to study the mechanisms and processes that enable metastasis. We need to develop a greater understanding of the cellular and molecular mechanisms that cause metastasis and also we need to do more. We must also consider the micro- and macro-environmental factors that influence this disease. Studying this environmental context has led us to update the 'seed and soil' hypothesis which dates back to the 19th century. This theory describes cancerouscellsasseedsand thesubstrateas thesoilin target organs though this may seem antiquated. Nonetheless, the tissue specificity that researchers have recently observed in metastatic colonisation supports the validity of theseed and soiltheory. We now know that the metastatic potential of a tumour cell depends on multiple, reciprocal interactions between the primary tumour and distant sites. These interactions determine tumour progression. Studies of metastasis have allowed us to develop treatments that focus on therapeutic effectiveness. These new treatments account for the frequent metastasis of some tumours to target organs such as bones, lungs, brain, and liver. The purpose of this review is first to describe interactions between the cellular and molecular entities and the target organ tumour environment that enables metastasis. A second aim is to describe the complex mechanisms that mediate these interactions.
authors.affiliation: Life Sciences Centre, Institute for Advanced Studies Foundation [Fundación Instituto de Estudios Avanzado]-IDEA, Apartado 17606, Caracas 1015-A, Venezuela; Tumour Biology Culture and Tissue Laboratory, Experimental Biology Institute, Central University of Venezuela, Apartado Apartado 47114, Caracas 1041-A, Venezuela.
authors.forename: Francisco
authors.initials: F
authors.lastname: Arvelo
authors.affiliation: Life Sciences Centre, Institute for Advanced Studies Foundation [Fundación Instituto de Estudios Avanzado]-IDEA, Apartado 17606, Caracas 1015-A, Venezuela.
authors.forename: Felipe
authors.initials: F
authors.lastname: Sojo
authors.affiliation: Tumour Biology Culture and Tissue Laboratory, Experimental Biology Institute, Central University of Venezuela, Apartado Apartado 47114, Caracas 1041-A, Venezuela.
authors.forename: Carlos
authors.initials: C
authors.lastname: Cotte
keywords: cancer; exosomes; metastasis; micrometastasis; tropism; tumour micro-environment; tumour progression