Metastasis: new perspectives using multiphoton microscopy

Cancer is a disease of multiple systems and components that interact at both molecular and cellular levels leading to initiation, progression and spread of the disease. Lately there has been a tremendous increase in systems-level study of cancer and the use of integrative approaches to understand mechanisms of cancers and their metastases. Metastasis is one of the most enigmatic hallmarks of cancers characterized by complex molecular interactions. It is responsible for as much as 90% of cancer-associated mortality, yet remains the most poorly understood component of cancer pathogenesis. Many hypotheses have been postulated to explain the intricate nature of the metastatic process, but none of them completely accounted for the actual biological and clinical observations. Consequently, metastasis still remains an open issue with only few metastasis-inducing proteins experimentally validated so far. New advances in intravital microscopy (IVM) have recently been used to visualize the behavior of single metastasizing cells at subcellular resolution over several days, yielding new and unexpected insights into this process. In this chapter, we will provide a current overview of intavital microscopy, and discuss recent findings in this field obtained with IVM. Keyword: cancer, metastasis, intravital microscopy.