Thermo-stability and antitumor activity on colon cancer cell lines of monoclonal anti-CEA antibody-saporin immunotoxin.
Eight saporin peaks were obtained from the purification of seed extracts of Saponaria officinalis L. Saporin peak No. 6 (SAP-6) showed the highest activity in the inhibition of protein synthesis (98%) in an in vitro translation study. An immunotoxin (IT) was prepared from SAP-6 conjugated to a monoclonal anti-CEA antibody 26/5/1 (mab B) using N-succinimidyl pyridyl dithiopropionate (SPDP) and 2-iminothiolane as a cross linker. Under thermal stability study by a DSC (differential scanning calorimetry), the IT showed a denature temperature of 75 degrees C. In in vitro translation studies, the purified IT showed the same activity as SAP-6 at 10(-7) M and 10(-9) M protein concentration at 0, 30 and 60-min incubation effects with mab B and SAP-6 not conjugated at 24-hr incubation periods on human promyelocytic cell line HL 60 and on human colon adenocarcinoma cell lines which were SW 403, LoVo and LS 174 T. SAP-6, mab B and IT had no cytotoxic effect on HL-60. The IT showed a higher cytotoxic effect than SAP-6 in CEA-positive cell lines. The IT demonstrated the highest cytotoxic effect of 51% inhibition of control at 10(-7) M on the LS 174 T.
Manosroi
J
J
Department of Pharmaceutical Technology, Faculty of Pharmacy, Chiang Mai University, Thailand.
von Kleist
S
S
Manosroi
A
A
Grunert
F
F
D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000494:pharmacology*; D002272:Carcinoembryonic Antigen / Q000096:biosynthesis / Q000276:immunology*; D003110:Colonic Neoplasms / Q000473:pathology* / Q000628:therapy; D006358:Hot Temperature; D006801:Humans; D000922:Immunotoxins / Q000627:therapeutic use*; D009699:N-Glycosyl Hydrolases; D010940:Plant Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D054789:Ribosome Inactivating Proteins, Type 1; D000076985:Saporins; D014407:Tumor Cells, Cultured / Q000187:drug effects
D000911:Antibodies, Monoclonal; D000972:Antineoplastic Agents, Phytogenic; D002272:Carcinoembryonic Antigen; D000922:Immunotoxins; D010940:Plant Proteins; D054789:Ribosome Inactivating Proteins, Type 1; D009699:N-Glycosyl Hydrolases; D000076985:Saporins