Epigenetic silencing of cyclooxygenase-2 affects clinical outcome in gastric cancer
The present invention discloses methods of using the methylation status of the COX-2 gene promoter region as a biomarker for a gastric cancer patient to determine a prognosis and a treatment regimen, and to monitor the progress of a treatment regimen.
1. A method for determining a prognosis for a human gastric cancer patient, comprising:
obtaining a gastric tumor tissue sample from the patient;
extracting a genomic DNA sample from the gastric tumor tissue sample;
determining a methylation status of the genomic DNA for a predetermined number of base pairs around the COX-2 promoter; and
determining the prognosis of the patient, wherein the prognosis predicts a probability of survival for the patient, and wherein the methylation status of hypermethylation in the COX-2 promoter region indicates a favorable prognosis.
2. The method of claim 1 , wherein a status of hypomethylation in the COX-2 promoter region indicates a poor prognosis.
3. The method of claim 1 , wherein said predetermined number of base-pairs around the COX-2 promoter is −14 bp/+110 bp from a transcription site of the COX-2 promoter.
4. A method for determining a course of treatment for a human gastric cancer patient, comprising:
obtaining a gastric tumor tissue sample from the patient;
analyzing the gastric tumor tissue sample to determine a methylation status in the COX-2 promoter region with a predetermined number of base-pairs around the promoter to determine a prognosis, wherein the prognosis predicts a probability of survival for the patient, and wherein the methylation status of hypermethylation in the COX-2 promoter region indicates a favorable prognosis; and
prescribing a course of treatment for the patient based on the prognosis.
5. The method of claim 4 , wherein a methylation status of hypomethylation is determined and the prognosis is poor, an adjuvant therapy is prescribed.
6. The method of claim 1 , wherein the prognosis further predicts a probability of recurrence-free survival.
7. The method of claim 1 , wherein the prognosis further predicts a probability of overall survival.
8. The method of claim 5 , wherein the adjuvant therapy is a COX-2 inhibitor.
9. The method of claim 8 , wherein the COX-2 inhibitor is aspirin or celecoxib.