The transmission of frog renal tumors (Lucké) and subsequent induction of primary tumors by implantation or inoculation of tumor cell components into embryos and larvae of Rana pipiens has been studied.

Tumor cells were fractionated by centrifugation and filtration into oncogenically active subcellular components. The fractions were differentiated according to particle size, as mitochondrial, light mitochondrial, and microsomal fractions. Each of these contained aggregated or free viral particles when tumors with intranuclear inclusion bodies were used.

Injection of the mitochondrial and microsomal fractions into embryos from the blastula through the hatching stage induced renal carcinomas which appeared during or after metamorphosis. Both the pronephric and mesonephric kidneys developed tumors. The filtrate fraction (0.45 µ) of the tumor extract was less active but also caused renal tumor induction. The resultant renal carcinomas were identical with spontaneous, actively growing, primary adenocarcinomas. Both operational controls and fractions of normal kidney failed to produce tumors of any kind.

Implants of primary tumors into embryos “took” but were eventually rejected and failed to cause local or primary tumor growths. Injection of living dissociated tumor cells into embryos or larvae likewise failed to establish local growths or induced primary renal tumors in the young adults.

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Supported by Grant No. CA-07849 of the National Cancer Institute, NIH, Bethesda, Md.

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