The technology describes engineered primate cystathionine-γ-lyase enzymes with specific amino acid modifications that enhance their ability to degrade L-cyst(e)ine. These enzymes, intended for therapeutic use in cancer and cystinuria, improve stability and reduce immunogenicity.
Background
Cancer and cystinuria present significant therapeutic challenges due to their reliance on specific metabolic pathways. Many cancers, such as prostate, small cell lung carcinomas, glioblastomas, and hepatocellular carcinomas, depend heavily on extracellular cysteine and cystine for proliferation and survival. These tumors often overexpress the xCT cystine/glutamate antiporter, suggesting a loss of native cysteine biosynthetic capacity. Current treatments, including small molecule inhibitors like sulfasalazine, are limited as they do not completely block cysteine transport, leaving tumor cells with alternative sources. Similarly, cystinuria, a genetic disorder characterized by defective renal reabsorption of cystine, leads to recurrent kidney stones and significant morbidity. Existing treatments, such as hyperdiuresis and thiol drugs, are often inadequate or associated with severe side effects. Therefore, there is a need for more effective therapies that can deplete both cystine and cysteine to address these conditions comprehensively.
Technology description
The technology involves engineering human and primate-derived protein with L-cyst(e)ine degrading enzyme activity, specifically modified cystathionine-γ-lyases (CGLs). These modified enzymes have key amino acid substitutions, which enhance their ability to degrade L-cyst(e)ine. These modified enzymes are intended for therapeutic applications, particularly for treating cancer and cystinuria. The invention also includes nucleic acids encoding these modified enzymes, which can be delivered via various vectors for expression in host cells. Additionally, these enzymes can be linked to heterologous peptide sequences or polysaccharides, such as polyethylene glycol (PEG), to enhance their stability and reduce immunogenicity. Therapeutic formulations containing these modified enzymes can be administered intravenously or subcutaneously to deplete L-cyst(e)ine levels in patients, thereby inhibiting tumor growth or preventing cystine stone formation in cystinuria.
This technology is differentiated by its ability to efficiently degrade both L-cystine and L-cysteine, which are critical for the survival and proliferation of certain cancer cells and for preventing cystine stone formation in cystinuria patients. The specific amino acid substitutions in the modified CGL enzymes confer improved enzymatic properties, such as higher catalytic efficiency and stability under physiological conditions. By using primate-derived sequences, the risk of immunogenic reactions in human patients is minimized, allowing for repeated dosing and increased therapeutic efficacy. The ability to link these enzymes to stabilizing agents like PEG further enhances their serum stability and reduces immunogenicity, making them more suitable for therapeutic use. This combination of enhanced enzymatic activity, reduced immunogenicity, and increased stability makes these modified CGL enzymes a promising therapeutic option for treating cancer and cystinuria.
Benefits
- Enhanced ability to degrade L-cyst(e)ine, crucial for therapeutic applications in cancer and cystinuria
- Improved enzymatic properties due to specific amino acid substitutions
- Derived from primate cystathionine-γ-lyases, including human enzymes, reducing the likelihood of adverse immunological responses
- Can be encoded by nucleic acids for expression in host cells, facilitating therapeutic production
- Potential to inhibit tumor growth and prevent cystine stone formation in cystinuria patients
Commercial applications
- Cancer treatment
- Cystinuria treatment
- Enzyme therapy
- Gene therapy
- Drug formulations
Patent link
Issued patent US 10,865,403
