Cancer risk biomarkers
The present invention relates to methods and compositions for identifying biomarkers that indicate a biological state, in particular cancer or predisposition to cancer.
1. A method of identifying a risk for a bronchogenic carcinoma in an subject comprising:
obtaining a sample from the subject,
determining transcript abundance (TA) in the sample for a biomarker signature found in the sample, wherein the TA is determined by microarray analysis, quantitative polymerase chain reaction, or a combination of both, and wherein the biomarker signature consists of:
i) at least one antioxidant gene selected from the group consisting of: CAT, GPX1, GPX3, GSTM3, GSTP1, GSTT1, GSTZ1, MGST1 and SOD1;
ii) at least one DNA repair (DNAR) gene selected from the group consisting of: ERCC4, ERCC5 and XRCC1; and
iii) transcription factor gene CEBPG,
wherein the threshold levels for the genes comprise, where the second column is the cut-point determination on a log 10 scale, and where CA =cancer risk:
CAT
CA ≦ 4.81 or CA ≧ 5.18
GPX1
CA ≦ 5.50 or CA ≧ 5.83
GPX3
CA ≦ 3.31 or CA ≧ 3.47
GSTM3
CA ≦ 3.20 or CA ≧ 3.55
GSTP1
CA ≦ 6.38 or CA ≧ 6.70
GSTT1
CA ≦ 3.49 or CA ≧ 3.88
GSTZ1
CA ≦ 3.18 or CA ≧ 3.68
MGST1
CA ≦ 4.93 or CA ≧ 5.20
SOD1
CA ≦ 5.09 or CA ≧ 5.41
ERCC4
CA ≦ 2.55 or CA ≧ 3.04
ERCC5
CA ≦ 4.81 or CA ≧ 5.11
XRCC1
CA ≦ 4.57
CEBPG
CA ≦ 4.09 or CA ≧ 4.44;
and
determining if said TA for each gene in the biomarker is within the threshold levels for each gene, wherein, when said TA for each gene is within said threshold levels, such determination indicates whether said subject is at greater risk for a bronchogenic carcinoma.
2. A method for classifying a subject as having a greater risk for developing bronchogenic carcinoma, comprising:
a) obtaining a test sample from said subject;
b) determining transcript abundance (TA) in the sample for a biomarker signature found in the sample, wherein the TA is determined by microarray analysis, quantitative polymerase chain reaction, or a combination of both, and wherein the biomarker signature consists of: CEBPG, GPX1, GPX3, GSTM3, GSTT1, MGST1, SOD1 and XRCC1;
wherein threshold levels for genes comprise, where the second column is the cut-point determination on a log 10 scale, and where CA =cancer risk:
CEBPG
CA ≦ 4.09 or CA ≧ 4.44
GPX1
CA ≦ 5.50 or CA ≧ 5.83
GPX3
CA ≦ 3.31 or CA ≧ 3.47
GSTM3
CA ≦ 3.20 or CA ≧ 3.55
GSTT1
CA ≦ 3.49 or CA ≧ 3.88
MGST1
CA ≦ 4.93 or CA ≧ 5.20
SOD1
CA ≦ 5.09 or CA ≧ 5.41
XRCC1
CA ≦ 4.57;
c) calculating a combined score from relative transcript abundance (TA) expression levels of genes of the biomarker signature in the sample from the subject, wherein said calculating includes assigning a score based on whether said TA for each gene in the biomarker is within the threshold level for that gene;
d) classifying the subject into a high or low risk group based on the combined score;
e) monitoring the subject for development of bronchogenic carcinoma if the subject is in the high risk group; and,
e) selecting therapy if the subject is in the high risk group and is found to have developed bronchogenic carcinoma.
3. A method for predicting the risk of developing bronchogenic carcinoma in a subject, the method comprising the steps of:
a) providing a sample from a test individual;
b) determining transcript abundance (TA) levels in the sample for a biomarker signature found in the sample, wherein TA is determined by microarray analysis, quantitative polymerase chain reaction, or a combination of both, and wherein the biomarker signature consists of: CEBPG, GPX3, XRCC1, GPX1, GSTT1, GSTM3, MGST1 and SOD1;
wherein threshold levels for genes comprise, where the the second column is the cut-point determination on a log 10 scale, and where CA =cancer risk:
CEBPG
CA ≦ 4.09 or CA ≧ 4.44
GPX1
CA ≦ 5.50 or CA ≧ 5.83
GPX3
CA ≦ 3.31 or CA ≧ 3.47
GSTM3
CA ≦ 3.20 or CA ≧ 3.55
GSTT1
CA ≦ 3.49 or CA ≧ 3.88
MGST1
CA ≦ 4.93 or CA ≧ 5.20
SOD1
CA ≦ 5.09 or CA ≧ 5.41
XRCC1
CA ≦ 4.57;
c) deriving a score that captures the TA levels for the biomarkers, wherein said deriving includes assigning a score based on whether said TA for each gene in the biomarker is within the threshold level for that gene;
d) providing a reference model comprising threshold levels correlating the score with risk for developing bronchogenic carcinoma; and
e) comparing the score to the reference model, and predicting the risk for developing bronchogenic carcinoma for the subject.