DNA methylation biomarkers for lung cancer
The present invention relates to the identification of novel DNA biomarkers and the use of the aberrant methylation patterns of the biomarkers to diagnose a disease or a condition (e.g., a cancer) associated therewith. In particular, the present invention relates to the use of the novel DNA biomarkers to diagnose lung cancers, e.g., squamous cell carcinomas and adenocarcinomas.
1. A method of diagnosing lung cancer comprising:
obtaining a lung tissue test sample from a subject;
measuring a methylation level of one or a combination of DNA biomarkers selected from the group consisting of NR2E1 (SEQ ID NO. 33), OSR1 (SEQ ID NO. 7) and OTX1 (SEQ ID NO. 10) in the lung tissue test sample;
comparing the methylation level of the one or a combination of DNA biomarkers with the methylation level of a corresponding one or combination of DNA biomarkers in a normal lung tissue sample or lung standard sample; and
predicting that an increase in the methylation level of the lung tissue test sample in relation to that of the normal lung tissue sample or lung standard sample indicates that the subject is likely to have lung cancer.
2. The method of claim 1 wherein the lung cancer is squamous cell carcinoma.
3. The method of claim 1 wherein the lung cancer is adenocarcinoma.
4. The method of claim 1 wherein the methylation level is measured by a methylated-CpG island recovery assay (MIRA), a combined bisulfite-restriction analysis (COBRA), or a methylation-specific PCR (MSP).
5. The method of claim 4 wherein the methylation levels of the one or a combination of DNA biomarkers are measured by an MIRA-assisted microarray analysis.
6. The method of claim 1 wherein the increase is more than 2 fold.
7. The method of claim 6 wherein the increase is more than 3 fold.
8. A method of diagnosing lung cancer comprising:
1) obtaining a lung tissue test sample from a subject;
2) obtaining a genome DNA from the lung tissue test sample from the subject;
3) obtaining methylated regions from the genome DNA;
4) hybridizing the methylated regions to a DNA microarray comprising one or a combination of DNA biomarkers selected from the group consisting of NR2E1 (SEQ ID NO. 33), OSR1 (SEQ ID NO. 7) and OTX1 (SEQ ID NO. 10);
5) comparing the hybridization of the methylated regions from the genome DNA with the hybridization of the corresponding methylated regions of a normal lung tissue sample or lung standard sample genome DNA; and
6) predicting that an increase in the methylated regions of the genome DNA hybridizing to the DNA biomarker relative to the methylated regions of the normal lung tissue sample or lung standard sample genome DNA hybridizing to the one or a combination of DNA biomarkers indicates that the subject is likely to have lung cancer.
9. The method of claim 1 wherein the lung cancer is squamous cell carcinoma.
10. The method of claim 1 the lung cancer is adenocarcinoma.
11. The method of claim 1 wherein the methylation level is measured by a methylated-CpG island recovery assay (MIRA), a combined bisulfite-restriction analysis (COBRA), or a methylation-specific PCR (MSP).
12. The method of claim 11 wherein the methylation levels of the one or a combination of DNA biomarkers are measured by an MIRA-assisted microarray analysis.
13. The method of claim 1 wherein the increase is more than 2 fold.
14. The method of claim 13 wherein the increase is more than 3 fold.