[Electrophoretic Analysis of Abnormal Data Discovered by Serum Enzyme Testing].

Area of Science:

• Biochemistry
• Molecular Biology
• Genetics

Background:

• Lactate dehydrogenase (LD) isozymes are crucial biomarkers.
• Unusual LD electrophoretic patterns can arise from various molecular alterations.
• Genetic variants and epigenetic modifications, particularly DNA methylation, influence LD isozyme expression.

Purpose of the Study:

• To investigate the causes of abnormal lactate dehydrogenase (LD) isozyme patterns.
• To explore the role of genetic and epigenetic factors in LD isozyme alterations in cancer.
• To elucidate the mechanisms behind LD isozyme changes in retinoblastoma.

Main Methods:

• Electrophoretic analysis of lactate dehydrogenase (LD) isozymes.
• Investigation of gene expression and promoter methylation status of LDHA and LDHB genes.
• Analysis of a retinoblastoma patient and a corresponding cell line (R51).

Main Results:

• An abnormal LD-1-dominant isozyme pattern was observed in a retinoblastoma patient and R51 cell line.
• Transcriptional silencing via aberrant DNA methylation in the LDHA promoter region caused the abnormal pattern.
• Conversely, promoter hypermethylation of LDHB was linked to high LDHA expression in other cancers (gastrointestinal, prostate, breast).

Conclusions:

• LD isozyme patterns in cancer are influenced by gene dosage and expression, controlled genetically and epigenetically.
• Aberrant DNA methylation is a key epigenetic mechanism altering LDHA and LDHB expression in various cancers.
• LD isozyme analysis provides insights into cellular origins and regulatory mechanisms in oncogenesis.