Human Biochemistry, Volume 2 - Murray R. 1993

Special Topics
Cancer, Oncogenes, Growth Factors
Causes of Tumors — Radiation Energy

Tumor-initiating agents can be divided into three major groups: radiation energy, chemical compounds, and Viruses.

Ultraviolet rays, X-rays, and y-radiation exert mutagenic and carcinogenic effects. In all cases, DNA damage occurs. For example, ultraviolet light induces The formation of pyrimidine dimers. Irradiation can result in single- or double-strand DNA breaks and cross-linking. All of these lie at the ROOT of the mutagenic and carcinogenic effects of radiation. In addition to a direct effect on DNA, X-rays and y-rays cause the formation of free radicals in Tissues. Superoxide OH and other radicals can interact with DNA and other macromolecules, damaging them and thereby contributing to The Development of Cancer.

Class="center">

Fig. 57.1. Structure of three major chemical carcinogens used in experiments.

Table 57.3. Selected chemical carcinogens

Polycyclic aromatic Hydrocarbons

Benzpyrene, dimethylbenzanthracene

Aromatic amines

2-Acetylaminofluorene, N-methyl-4-aminoazobenzene (MAB)

Nitrosamines

Dimethylnitrosamine, diethylnitrosamine

Various agents

Alkylating agents (e.g., cyclophosphamide), diethylstilbestrol

Natural agents

Actinomycin D, aflatoxin B,

Inorganic substances

Arsenate, asbestos, beryllium, cadmium, chromium





Last update: 06/08/2026

Editorial and Educational Adaptation: This material has been compiled based on the primary/original source text. The project team performed an editorial review, corrected technical inaccuracies, structured sections, and adapted the content for an educational format.

What was processed:

  • elimination of formatting defects (OCR errors, structural breaks, corrupted characters);
  • editorial organization of content;
  • standardization of terminology in accordance with academic sources;
  • verification of factual statements against the original source text.

All mentions of the author, publication year, and origin of the primary text have been preserved in accordance with the source.