ranpirnase

Ranpirnase is a ribonuclease enzyme originally isolated from the eggs of the northern leopard frog (*Rana pipiens*). It belongs to the RNase A superfamily and is notable for its small size and high heat stability. Ranpirnase exerts its biological effects by preferentially degrading transfer RNA (tRNA) within cells, leading to inhibition of protein synthesis, cell cycle arrest in G1 phase, and ultimately cytostatic and cytotoxic effects. This mechanism results in selective toxicity toward tumor cells while sparing most normal cells. Ranpirnase has demonstrated antitumor activity both *in vitro* and *in vivo* across several cancer models, including mesothelioma, pancreatic cancer, renal cell carcinoma, and non-small cell lung cancer. In addition to its anticancer properties, ranpirnase has shown promise as an antiviral agent due to its ability to degrade tRNA without affecting mRNA or rRNA protected by proteins. The drug is administered extracellularly but acts intracellularly after endocytic uptake into target cells. Ranpirnase (Onconase) has not been approved by the FDA for any indication but has received orphan-drug and fast-track status for malignant mesothelioma. Clinical trials have also explored its use against other cancers such as pancreatic cancer and renal cell carcinoma; however, some studies were withdrawn or did not progress beyond early phases. Its unique mechanism—preferential degradation of tRNA—distinguishes it from traditional chemotherapeutics. Developed by Alfacell Corporation and TamirBio, and manufactured by Alfacell Corporation.

Brand names

Onconase

Other names

P-30 ProteinP30 ProteinP 30 ProteinAmphinase