Activity of RA-700, a cyclic hexapeptide from Rubiae Radix, in the human tumor clonogenic assay.

Abstract

In vitro phase II study of a new cyclic hexapeptide anticancer agent, RA-700 was studied on the human tumor clonogenic assay. From the results of the study using the human tumor cell line of lung cancer (PC-6), RA-700 appears to possess time-dependent antitumor activity. Therefore, against the 148 human specimens of various malignancies, the chemosensitivity of RA-700 was tested at the concentrations of 10 micrograms/ml, 1 microgram/ml and 0.1 microgram/ml in continuous exposure schedule for 2 weeks by using the human tumor clonogenic assay. If the criteria for in vitro sensitivity was based on greater than or equal to 70% inhibition of colony formation, out of 148 specimens 59 specimens (40%) were evaluable and the chemosensitivity rate of RA-700 were 67% (4/6), 22% (2/9), 17% (3/18) and 10% (1/10) for ovarian cancer, non-small cell lung cancer, breast cancer and colorectal cancer, respectively. An overall chemosensitivity rate against 13 different histologic types of cancers was 22% (13/59) (greater than or equal to 70% inhibition of colony formation) and 39% (23/59) (greater than or equal to 50% inhibition of colony formation). RA-700 showed almost same chemosensitivity compared to that of five standard anticancer drugs (adriamycin, mitomycin C, cisplatin, vinblastine and 5-FU), but the spectrum of RA-700 activity appears to be different from that of the standard drugs. Furthermore, the antitumor activity of RA-700 had no relationship with prior chemotherapy. These results indicated that RA-700 is a candidate for phase I study.

• Authors: K Inoue, T Mukaiyama, T Kobayashi, M Ogawa
• Journal: Investigational new drugs (Invest New Drugs) Vol. 4 Issue 3 Pg. 231-6 ( 1986) ISSN: 0167-6997 [Print] United States
• PMID: 3818226 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antineoplastic Agents, Phytogenic
• Peptides, Cyclic
• Plant Extracts
• RA VII

Topics

• Antineoplastic Agents, Phytogenic (pharmacology)
• Colony-Forming Units Assay
• Drug Evaluation
• Humans
• Neoplasms (pathology)
• Peptides, Cyclic (pharmacology)
• Plant Extracts (pharmacology)
• Tumor Stem Cell Assay