G. I. Abelev* and T. L. Eraiser: On the Path to Understanding the Nature of Cancer

Blokhin Cancer State Research Center, Russian Academy of Medical

Abstract—In this essay crucial problems of the origin of cancer and the development of malignancy are discussed. The problem of precancer and three ways leading to malignancy are considered: induction of tumor precursors, accumulation of genetic traits common for tumor growth, and the role of inflammation in tumor induction. The nature of viral oncogenes and modes of their action are described in the context of their origin as a component of the viral genome. Oncogenes of RNA-containing viruses and DNA-containing tumorigenic viruses are described together with cellular protooncogenes, which are progenitors of RNA-containing viral oncogenes. Hematological malignancies are described as an intermediate form between simple tumors induced by a single oncogene and more complicated epithelial tumors. The roles of tumor suppressor genes and the interaction of several oncogenes in the formation of carcinomas and also the role of progression in tumor evolution are discussed.

DOI: 10.1134/S0006297908050015
Key words: carcinogenesis, precancer, oncogenes, protooncogenes, suppressors, progression, epithelial—mesenchymal transition

A malignant tumor is an autonomously proliferating immortal cell clone continuously evolving to independence outside the body`s control against invasion and metastasis.

The nature of malignant tumors has been most comprehensively studied during the last 50 years. Although it is still far from being clear, it became possible to determine the fundamental mechanisms involved in malignant growth. In 2006, a textbook The Biology of Cancer [1] on fundamental oncology was published by Robert Weinberg. This monograph is an attempt to formulate general principles of malignant growth. This attempt has created a basis for understanding and estimation of the
Abbreviations: AFP) alpha-fetoprotein; CLL) chronic lym-phoblast leukemia; CML) chronic myeloid leukemia; ECM) extracellular matrix; EMT) epithelial—mesenchymal transition; FISH) fluorescent in situ hybridization; GSA) group-specific antigen; LOH) loss of heterozygosity; MGCV) mammary gland cancer virus of low oncogenicity; MMP) membrane met-alloproteinases; PCR) polymerase chain reaction; RSV) Rous sarcoma virus; VEGF) vascular endothelium growth factor; VIGF) VEGF inhibitor. * To whom correspondence should be addressed.

trends in studies of the nature of cancer and for determination of the place of a researcher`s own work in the general picture of advances to understanding the nature of malignant growth. The present collection of analytical reviews is designed to elucidate separate parts of this picture without erasing its general outlines.

This article is in no way a summary or review of Weinberg`s book; it only presents some considerations that appear in the course of reading the book.

 

garriabelev.narod.ru

Received December 4, 2007