Index >>Viruses and Cancer >>Viral Gene Hypothesis

Viral Gene Hypothesis - In 1911 Rolls discovered that a cell free filtrate could transfer tumour in the Plymouth Rock hen, an indication that the tumour was virus borne.
This work, however, did not meet with belief at that time.
It was 30 years later, when RNA tumour viruses causing Leukemia in mice were discovered, that the viral theory of cancer began to gain ground.
Rous virus was later shown to be an RNA virus, and was named Rous Sarcoma Virus (RSV)
Viruses and human cancer
:There is convincing evidence that viruses cause a number of specific cancers in animals.
Viruses causing malignant tumours have been isolated from many animals including fish, frogs, mice, rats, squirrels, dogs, deer and horses.

(i) the impossibility of injecting cancer causing viruses into human beings,
(ii) the viruses concerned may not be transmissible,
(iii) viruses if present may not have a separate identity, but their genetic material may be incorporated into the DNA of human chromosomes and
(iv) the presence of harmless viruses in tumours may confuse the picture

(iii) Herpes simplex, type 2, virus has often, been found to be associated with cervical cancer.
(iv) Enzymes, antigens and nucleic acid sequences of retroviruses have often been reported to be associated with various human cancers.
(v)Virus like RNA DNA particles have been isolated from patients with breast cancer and acute leukemia. In both cases.
however, the virus like particles were obtained from tissues after culturing and not from tissues obtained from the body.
Recently virus like particles isolated from a leukemia patient have been cultured in bone marrow cells