Methylation markers and targeted methylation probe panel
The present description provides a cancer assay panel for targeted detection of cancer-specific methylation patterns. Further provided herein are methods of designing, making, and using the cancer assay panel for the diagnosis of cancer.
1. A mixture comprising (a) an assay panel for enriching modified polynucleotides for detecting cancer and/or a type of cancer in a subject, and (b) converted cell-free DNA (cfDNA) molecules or amplification products thereof;
wherein the converted cfDNA molecules comprise deaminated nucleotides obtained by treating cfDNA molecules with a deaminating agent;
wherein the assay panel comprises at least 1,000 polynucleotide probes, wherein the at least 1,000 polynucleotide probes comprise at least 500 different pairs of probes comprising a first probe and second probe, wherein the first probe differs from the second probe and overlaps with the second probe by an overlapping sequence of at least 30 contiguous bases;
wherein the polynucleotide probes of the at least 500 different pairs of probes are configured to collectively hybridize to a modified polynucleotide obtained by processing cell-free DNA (cfDNA) molecules derived from at least 500 different target genomic regions of the subject, or amplification products thereof;
wherein the target genomic regions are human genomic regions;
wherein at least one probe for each of the at least 500 different target genomic regions (i) comprises a length of at least 45 bases complementary to a sequence of the target genomic region or a modified sequence thereof produced by the processing, and (ii) does not have at least 90% complementarity to at least 45 contiguous bases of 20 or more off-target regions in a GRCh37/hg19 genome;
wherein an off-target region does not comprise any of the at least 500 different target genomic regions; and
wherein each of the at least 500 different target genomic regions comprises at least five methylation sites and are differentially methylated in cancer samples relative to non-cancer samples.
2. The mixture of claim 1 , wherein each of the at least 500 different target genomic regions is determined to be anomalously methylated in cancer training samples based on criteria comprising a number of cancer samples that comprise an anomalously methylated cfDNA fragment that overlaps the target genomic region, and wherein the target genomic region is determined to be anomalously methylated in cancer training samples relative to non-cancer training samples based on criteria comprising N cancer and N non-cancer , wherein:
N cancer , for each CpG site, is a number of cancer samples that include a cfDNA fragment covering the CpG site in the cfDNA fragment that (1) has at least 4 CpG sites, wherein at least 70% of the CpG sites are methylated or unmethylated, and (2) has a p-value rarity in non-cancer samples of below a threshold value; and
N non-cancer , for each CpG site, is a number of non-cancer samples that include a cfDNA fragment covering the CpG site in the cfDNA fragment that (1) has at least 4 CpG sites, wherein at least 70% of the sites are methylated or unmethylated, and (2) has a p-value rarity in non-cancer samples of below a threshold value.
3. The mixture of claim 2 , wherein each of the at least 500 different target genomic regions is determined to be anomalously methylated based on criteria positively correlated with N cancer and negatively correlated with N non-cancer .
4. The mixture of claim 2 , wherein each of the at least 500 different target genomic regions is determined to be anomalously methylated based on a score, wherein the score is calculated as (N cancer +1)/(N cancer +N non-cancer +2).
5. The mixture of claim 1 , wherein the processing of the cfDNA molecules comprises converting unmethylated C (cytosine) in the cfDNA molecules to U (uracil) to form the modified polynucleotides.
6. The mixture of claim 1 , wherein each of the at least 1,000 polynucleotide probes is conjugated to an affinity moiety, wherein the affinity moiety is not a nucleic acid.
7. The mixture of claim 2 , wherein each of the at least 500 different target genomic regions is either:
(i) hypermethylated in the cancer training samples and hypomethylated in the non-cancer training samples; or
(ii) hypomethylated in the cancer training samples and hypermethylated in the non-cancer training samples.
8. The mixture of claim 1 , wherein each of the at least 500 different target genomic regions is selected from SEQ ID NOs: 1-1644.
9. The mixture of claim 1 , wherein each of the at least 500 different target genomic regions is selected from SEQ ID NOs: 1645-5270.
10. The mixture of claim 1 , wherein each of the at least 500 different target genomic regions is selected from SEQ ID NOs: 5271-16837.
11. The mixture of claim 1 , wherein each of the at least 500 different target genomic regions is selected from SEQ ID NOs: 16838-25984.
12. The mixture of claim 1 , wherein each of the at least 500 different target genomic regions is selected from SEQ ID NOs: 15985-46929.
13. The mixture of claim 1 , wherein each of the at least 500 different target genomic regions is selected from SEQ ID NOs: 46930-67335.
14. The mixture of claim 1 , wherein each of the at least 500 different target genomic regions is selected from SEQ ID NOs: 67336-101617.
15. The mixture of claim 1 , wherein each of the at least 500 different target genomic regions is selected from SEQ ID NOs: 101618-131822.
16. The mixture of claim 1 , wherein the at least 500 different target genomic regions comprise at least 40% of the genomic regions in one or more of: (i) SEQ ID NOs: 1-1644, (ii) SEQ ID NOs: 1645-5270, (iii) SEQ ID NOs: 5271-16837, (iv) SEQ ID NOs: 16838-25984, (v) SEQ ID NOs: 15985-46929, (vi) SEQ ID NOs: 46930-67335, (vii) SEQ ID NOs: 67336-101617, or (viii) SEQ ID NOs: 101618-131822.
17. The mixture of claim 1 , wherein the at least 500 different target genomic regions comprise at least 1,000 genomic regions in one or more of: (i) SEQ ID NOs: 1-1644, (ii) SEQ ID NOs: 1645-5270, (iii) SEQ ID NOs: 5271-16837, (iv) SEQ ID NOs: 16838-25984, (v) SEQ ID NOs: 15985-46929, (vi) SEQ ID NOs: 46930-67335, (vii) SEQ ID NOs: 67336-101617, or (viii) SEQ ID NOs: 101618-131822.
18. The mixture of claim 1 , wherein the mixture comprises the converted cell-free DNA (cfDNA) molecules.
19. The mixture of claim 1 , wherein an entirety of the at least 1,000 polynucleotide probes are configured to hybridize to modified polynucleotides derived from at least 500 different target genomic regions.
20. The mixture of claim 1 , wherein (i) each probe of a probe pair further comprises a non-overlapping sequence with respect to the other probe of the pair, (ii) the overlapping sequence of at least 30 nucleotides of a probe pair is complementary to an internal sequence of one of the target genomic regions or modified sequence thereof produced by the processing (iii) the non-overlapping sequence is at least 15 nucleotides in length, and (iv) the non-overlapping sequences of the probe pair are complementary to different sequences at different ends of the internal sequence.
21. The mixture of claim 20 , wherein the non-overlapping sequences are at least 50 nucleotides in length.
22. The mixture of claim 20 , wherein each of the at least 1,000 polynucleotide probes are at least 75 nucleotides in length.
23. The mixture of claim 1 , wherein the at least 1,000 polynucleotide probes together comprise at least 1 million bases.