On the earth, there are a large number of microorganisms coexisting with humans, some of which are beneficial to humans, and the other is harmful to humans. Human pneumonia, gastritis, enteritis and other diseases are often caused by bacteria, viral hepatitis, mumps, measles and other diseases are often caused by viruses, diseases, schistosomiasis and other diseases are caused by parasites.
Do you know that some microorganisms can also cause some cancers?
We briefly introduce the situation of biological carcinogenesis as follows:
Virus researchers have found that many viruses are related to the occurrence of human cancer. Epstein Barr virus (often known as EB virus) is associated with malignant lymphoma, leukemia, infectious mononucleosis and nasopharyngeal carcinoma in African children. Human papillomavirus (HPV) is closely related to the occurrence of cervical cancer in women. Different types of papillomavirus are also associated with skin tumors, tongue cancer, laryngeal cancer, etc. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are associated with the formation of hepatocellular carcinoma. HIV often causes Kaposi sarcoma, lymphoma and leukemia.
Some molds have a very clear relationship with the occurrence of cancer. For example, Aspergillus flavus and Aspergillus versicolor can produce aflatoxin, which may cause human liver cancer. T-2 toxin produced by Fusarium can induce gastric cancer, pancreatic cancer and brain tumors in experimental animals. Penicillium producing griseofulvin can induce thyroid cancer or liver cancer in mice. The study also proved that several common molds in the food of Linzhou City, Henan Province, China, such as Fusarium moniliforme, Aspergillus versicolor, Alternaria alternata, Geotrichum candidum, etc., can promote the formation of nitrosamines in the food. Mycotoxins and nitrosamines play a synergistic role, which is closely related to the occurrence of esophageal cancer in local people.
Bacteria – Helicobacter pylori (HP)
Some scientists believe that Helicobacter pylori infection is related to gastritis, gastric ulcer and gastric cancer. Killing Helicobacter with some antibiotics can reduce the incidence of gastritis and gastric cancer. Helicobacter pylori infection not only directly damages the gastric mucosa and changes the physiological function of gastric acid secretion, but also has evidence that the toxin of Helicobacter pylori can cause intracellular chromosome damage and DNA strand breakage. Many scholars believe that Helicobacter pylori is an important factor in the early stage of gastric cancer. Therefore, scientists advocate that antibiotic treatment for patients with symptomatic gastritis and gastric ulcer caused by Helicobacter pylori can reduce the occurrence of gastric cancer.
Some parasites in the body are related to certain cancers, such as the high incidence of colon and rectal cancer in Chinese patients with “schistosomiasis japonica”, and bladder cancer caused by “schistosomiasis aegypti” in the Middle East. Clonorchis sinensis (Clonorchis sinensis) infection may cause cholangiocarcinoma of the liver.
The formation of cancer is multifactorial and multistage. Studying and understanding its etiology will help us to prevent and treat it.