Bioactivity of C3H and RIII mammary tumor viruses in virgin female BALB/c mice.
The bioactivities of C3H and RIII mammary tumor virus (MuMTV) in virgin female BALB/c mice differed. The average number of mammary hyperplastic alveolar nodules per mouse after noduligenic tests was 20.1 in BALB/cfC3H and 10.7 in BALB/cfRIII females. Spontaneous mammary tumor incidence after 20 months of observation was 47.5% in BALB/cfC3H and 14.6% in BALB/cfRIII females (P less than 0.01).  The frequency of lung metastases in mammary tumor-bearing mice was 63.1% in BALB/cfC3H and 16.6% in BALB/cfRIII females (P less than 0.05), although the clinical duration of mammary tumors was the same. These data demonstrated a lower bioactivity of RIII MuMTV when compared to C3H MuMTV in BALB/c mice and suggested that the causative virus may control all the steps of mouse mammary tumor development, including metastasis.
D000818:Animals; D005260:Female; D008175:Lung Neoplasms / Q000209:etiology; D008325:Mammary Neoplasms, Experimental / Q000209:etiology*; D008324:Mammary Tumor Virus, Mouse; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008815:Mice, Inbred Strains; D008892:Milk / Q000382:microbiology; D009362:Neoplasm Metastasis; D011247:Pregnancy; D013045:Species Specificity