Advancements in Life Sciences and Characteristic Features of Cancer Cells

Abstract

Advances in modern life sciences have primarily focused on cellular research because of the "Cell Theory" (Schleiden and Schwann 1838), which defi nes the cell as the basic unit of all organisms. Since cells are the common structural unit of a variety of organisms including animals and plants, it was hypothesized that complex life phenomena of multicellular organisms could be understood by studying individual cells. Molecular-level research began in 1953, when the double helix structure of DNA-the genetic material that transmits cellular characteristics to the next generation-was elucidated by Watson and Crick. Subsequently, advances in the understanding of the functions and mechanisms of cells were made rapidly. As molecular-level research of DNA, RNA, and proteins uncovered the mysteries of life, Monod claimed that life phenomena at the molecular level were similar in all organisms. What is true for E. coli must also be true for elephants.-J. Monod (1954) The aforementioned statement implies that studies on unicellular E. coli can aid our understanding of a larger and more complex organism such as an elephant. This rationale is based on the hypothesis that the cell is the basic unit of all life forms and hence, the life phenomena of a unicellular organism are identical to those of a mul-ticellular organism. Therefore, it was thought that the complex life phenomena of the metaphorical elephant as well as humans, our main interest, could be understood by studying them at the cellular level. Furthermore, such research could improve our understanding of fatal human diseases and consequently therapies could be offered. This argument has been the unwavering foundation of life science research for the last 60 years. Therefore, this viewpoint has also dominated cancer research, the most studied area in life sciences to date. Consequently, wide-ranging and complex molecular mechanisms underlying cancer have been well characterized. Herein, we briefl y examine the characteristics of cancer as elucidated by this approach and describe the history of the development of anticancer drugs based on these characteristics. We also discuss whether the understanding of cancer at the molecular level should be our ultimate goal.