Parvovirus H-1 inhibits growth of short-term tumor-derived but not normal mammary tissue cultures.

Infection with parvovirus H-1 strongly interfered with the proliferation of non-established tissue cultures derived from human breast tumors, but had little effect on the growth of corresponding normal human mammary cells. Even though tumor cells were always more sensitive to the virus than normal tissue from the same patient, appreciable quantitative differences were observed among tumor specimens. With time and sub-cultures, the killing effect of the virus on tumor cells became amplified. The impaired growth of infected tumor cells was due both to cytotoxic and to cytostatic action of H-1 virus and was associated with their greater capacity for virus-DNA amplification as compared with normal cells.