Ribozyme against mutant K-ras mRNA suppresses tumor growth of pancreatic cancer

Area of Science:

• Oncology
• Molecular Biology
• Gene Therapy

Background:

• Point mutations in the K-ras gene are frequent in human pancreatic carcinomas.
• These mutations are potential targets for therapeutic intervention.
• Ribozymes offer a method for sequence-specific gene targeting.

Purpose of the Study:

• To design and evaluate an anti-K-ras ribozyme for pancreatic cancer treatment.
• To assess the efficacy of a recombinant adenovirus expressing the ribozyme in a mouse model.

Main Methods:

• Designed an anti-K-ras ribozyme targeting codon 12 mutations (GGT to GTT).
• Generated a recombinant adenovirus (rAd/anti-K-ras Rz) for ribozyme expression.
• Inoculated Capan-1 human pancreatic carcinoma cells into athymic mice to create tumor xenografts.
• Directly injected rAd/anti-K-ras Rz into established tumors (approx. 100 mm³).

Main Results:

• Injection of rAd/anti-K-ras Rz led to tumor growth suppression or regression in 68% (15/22) of xenografts.
• Complete tumor regression was observed in 6 out of 15 affected tumors.
• One tumor showed recurrence after initial regression.

Conclusions:

• Recombinant adenovirus-mediated delivery of an anti-K-ras ribozyme can effectively suppress or reverse the malignant phenotype in human pancreatic tumors with K-ras mutations.
• This approach shows promise as a targeted gene therapy for K-ras-mutated pancreatic cancer.