Which molecular events can lead to carcinogenesis?
The process of carcinogenesis begins when the DNA is damaged, which then leads to a cascade of events leading to the development of a tumor. Ultraviolet (UV) radiation causes DNA damage, inflammation, erythema, sunburn, immunosuppression, photoaging, gene mutations, and skin cancer.
What are mechanisms that cause cancer?
Cancer is caused by specific DNA damage. Several common mechanisms that cause DNA damage result in specific malignant disorders: First, proto-oncogenes can be activated by translocations.
What factors agents that contribute to carcinogenesis?
Exogenous Factors Influencing Carcinogenesis Important exogenous factors that contribute to induction of cancer include natural and synthetic chemicals, environmental exposures to ultraviolet and medical radiation, diet and lifestyle, and infectious agents, such as viruses, parasites, and bacteria.
What are the 3 stages of carcinogenesis?
The three-stage theory of carcinogenesis is one of the most common explanations for the development of cancer. This theory divides cancer development into three stages: initiation, promo- tion, and progression.
What is carcinogenesis explain the various types of carcinogenesis?
carcinogen, any of a number of agents that can cause cancer in humans. They can be divided into three major categories: chemical carcinogens (including those from biological sources), physical carcinogens, and oncogenic (cancer-causing) viruses.
What are the 4 stages of carcinogenesis?
Carcinogenesis can be divided conceptually into four steps: tumor initiation, tumor promotion, malignant conversion, and tumor progression (Figure 17-1). The distinction between initiation and promotion was recognized through studies involving both viruses and chemical carcinogens.
What are the 3 phases of carcinogenesis?
What are the three types of genes that contribute to cancer?
There are 2 basic types of genetic mutations:
- Acquired mutations. These are the most common cause of cancer.
- Germline mutations. These are less common.
- Tumor suppressor genes. These are protective genes.
- Oncogenes. These turn a healthy cell into a cancerous cell.
- DNA repair genes.
How does DNA mutation cause cancer?
Cancers are caused by damage to the DNA in your cells. These changes are called “gene mutations.” Gene mutations can build up in cells in your body over time. Cells with too many mutations may stop working normally, grow out of control and become cancerous.
What are main classes of genes responsible for carcinogenesis?
Two classes ofgenes, proto-oncogenes and tumor-suppressor genes, are involved in the evolution of most, ifnot all, cancers (Table 2).
What are the principles of carcinogenesis?
Two-Step Process of Carcinogenesis Carcinogenesis is the uncontrolled replication of tissue cells with a monoclonal character, implying origin from a single cell mutation. Chemicals that cause cancer do so either by (1) initiating a mutation or by (2) promoting replication of a mutant. Both steps are required.