Related Experiment Video
Updated: Mar 14, 2026

Author Spotlight: Genetic Profiling for Fluorouracil Response in Gastric Cancer
Published on: May 10, 2024
Thymidylate synthase polymorphism in Mexican patients with colon cancer treated with 5-fluorouracil
Clara Patricia Rios-Ibarra1, Claudia Janeth Rodriguez-Silva, Yamil Alonso Lopez-Chuken
1Department of Biochemistry and Molecular Medicine, School of Medicine, Autonomous University of Nuevo Leon, Mexico (UANL).
Purpose:
We analyzed the genotype and allele frequency of variable number tandem repeats (VNTR)-thymidylate synthase (TS) and its relationship with the disease evolution in colon cancer patients.
Methods:
We selected 24 paraffin-embedded colon cancer tissue samples from Mexican patients who received a 5-fluorouracil (5-FU)-based chemotherapy regimen. Tumor tissue was digested with proteinase K and genomic DNA was isolated by the standard method with phenol-chloroform extraction. Polymerase chain reaction (PCR) was performed for TS genotyping of VNTR and the results were evaluated directly in a stained agarose gel.
Results:
The allele frequency of 2 repeats (2R) was greater (0.66) than 3R (0.34) in metastatic colon cancer (x2=10.24; p=0.001)) however, no difference in allelic distribution between 2R (0.54) and 3R (0.46) in non metastatic patients was observed (x2=0.640; p=0.424).
Conclusion:
Our results suggest that Mexican patients with colon cancer present differences in the allelic distribution, the 2R allele being the most frequent.
Related Concept Videos
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu
Translation
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of...
Translation
Translation Produces the Building Blocks of Life
Proteins are...
Drugs for Treatment of Ulcerative Colitis in IBD

