Towards a small molecule inhibitor of Lactate Dehydrogenase-A
Lactate Dehydrogenase-A (LDH-A) is up-regulated in a broad array of cancers and is associated with poor prognosis. Involved in the hypoxic response, LDH-A is a HIF-1 target and is responsible for the enzymatic reduction of pyruvate to lactate. This is important for several reasons, chiefly (1) the r...
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| Format: | Thesis |
| Language: | English |
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2011
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| _version_ | 1826299310014201856 |
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| author | Lomas, A |
| author2 | Harris, A |
| author_facet | Harris, A Lomas, A |
| author_sort | Lomas, A |
| collection | OXFORD |
| description | Lactate Dehydrogenase-A (LDH-A) is up-regulated in a broad array of cancers and is associated with poor prognosis. Involved in the hypoxic response, LDH-A is a HIF-1 target and is responsible for the enzymatic reduction of pyruvate to lactate. This is important for several reasons, chiefly (1) the regeneration of NAD+ which feeds back into earlier glycolytic stages and (2) the depletion of intracellular pyruvate concentrations. High intracellular pyruvate is known to inhibit HDACs and is associated with increased apoptosis. LDH-A is also known to be controlled by oncogenes such as c-Myc suggesting an oncogenic role. Studies have shown that the knock-out of LDH-A reduces proliferation and tumourgenicity, and stimulates the mitochondria. This thesis therefore had three aims: firstly, to validate LDH-A inhibition and elucidate its full nature in terms of the implications for tumour survival; secondly, to ascertain the role of LDH-B in order to determine whether selectivity towards LDH-A would be a necessary feature of any small molecule; lastly, to recapitulate siRNA mediated LDH-A inhibition with small molecule inhibitors that had the potential for clinical application. The thesis examined both clinical data and a broad panel of cultured cancer cell types in order to select appropriate model in which to validate siRNA mediated inhibition of LDH-A and LDH-B. After it was demonstrated that LDH-A inhibition reduced the growth of cultured cells, a range of techniques were used to quantify this reduced growth in terms of cell death and changes in metabolism. Further to this, literature studies had proposed a role for LDH-B in maintaining lactate fuelled tumour growth; however, this thesis shows that in the cell lines studied, lactate-fuelled tumour growth was an LDH-A dependent phenomenon. Finally, a high throughput assay system was designed and validated and a library of small molecules was selected, synthesized, and screened in order to identify selective inhibitors of LDH-A. |
| first_indexed | 2024-03-07T04:59:58Z |
| format | Thesis |
| id | oxford-uuid:d7f1416e-0d3d-4b4e-af62-7bbf4d52cf90 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T04:59:58Z |
| publishDate | 2011 |
| record_format | dspace |
| spelling | oxford-uuid:d7f1416e-0d3d-4b4e-af62-7bbf4d52cf902022-03-27T08:44:39ZTowards a small molecule inhibitor of Lactate Dehydrogenase-AThesishttp://purl.org/coar/resource_type/c_db06uuid:d7f1416e-0d3d-4b4e-af62-7bbf4d52cf90ChemistryPharmacologyMedicinal ChemistryOncologyChemical BiologyEnglishOxford University Research Archive - Valet2011Lomas, AHarris, ARussell, ALactate Dehydrogenase-A (LDH-A) is up-regulated in a broad array of cancers and is associated with poor prognosis. Involved in the hypoxic response, LDH-A is a HIF-1 target and is responsible for the enzymatic reduction of pyruvate to lactate. This is important for several reasons, chiefly (1) the regeneration of NAD+ which feeds back into earlier glycolytic stages and (2) the depletion of intracellular pyruvate concentrations. High intracellular pyruvate is known to inhibit HDACs and is associated with increased apoptosis. LDH-A is also known to be controlled by oncogenes such as c-Myc suggesting an oncogenic role. Studies have shown that the knock-out of LDH-A reduces proliferation and tumourgenicity, and stimulates the mitochondria. This thesis therefore had three aims: firstly, to validate LDH-A inhibition and elucidate its full nature in terms of the implications for tumour survival; secondly, to ascertain the role of LDH-B in order to determine whether selectivity towards LDH-A would be a necessary feature of any small molecule; lastly, to recapitulate siRNA mediated LDH-A inhibition with small molecule inhibitors that had the potential for clinical application. The thesis examined both clinical data and a broad panel of cultured cancer cell types in order to select appropriate model in which to validate siRNA mediated inhibition of LDH-A and LDH-B. After it was demonstrated that LDH-A inhibition reduced the growth of cultured cells, a range of techniques were used to quantify this reduced growth in terms of cell death and changes in metabolism. Further to this, literature studies had proposed a role for LDH-B in maintaining lactate fuelled tumour growth; however, this thesis shows that in the cell lines studied, lactate-fuelled tumour growth was an LDH-A dependent phenomenon. Finally, a high throughput assay system was designed and validated and a library of small molecules was selected, synthesized, and screened in order to identify selective inhibitors of LDH-A. |
| spellingShingle | Chemistry Pharmacology Medicinal Chemistry Oncology Chemical Biology Lomas, A Towards a small molecule inhibitor of Lactate Dehydrogenase-A |
| title | Towards a small molecule inhibitor of Lactate Dehydrogenase-A |
| title_full | Towards a small molecule inhibitor of Lactate Dehydrogenase-A |
| title_fullStr | Towards a small molecule inhibitor of Lactate Dehydrogenase-A |
| title_full_unstemmed | Towards a small molecule inhibitor of Lactate Dehydrogenase-A |
| title_short | Towards a small molecule inhibitor of Lactate Dehydrogenase-A |
| title_sort | towards a small molecule inhibitor of lactate dehydrogenase a |
| topic | Chemistry Pharmacology Medicinal Chemistry Oncology Chemical Biology |
| work_keys_str_mv | AT lomasa towardsasmallmoleculeinhibitoroflactatedehydrogenasea |