Risk stratification method for a patient having a polymorphism
11408035 · 2022-08-09
Assignee
Inventors
Cpc classification
G16B40/00
PHYSICS
G16B20/20
PHYSICS
C12Q2600/112
CHEMISTRY; METALLURGY
G16H50/30
PHYSICS
International classification
G16B20/20
PHYSICS
C12P19/34
CHEMISTRY; METALLURGY
Abstract
A risk stratification method for a patient in a disease state and specifically patients presenting a tumor, includes determining if the patient is a homozygote or heterozygote and further determining the allelic expression for the patient, CC, T/C, or C/T. For patients having the cytosine methylated, they have a C/T allelic expression and patients without a methylated cytosine have a T/C allelic expression. A patient with a TT allelic expression is classified as a highest risk patient, a patient with a T/C allelic expression is classified as a second highest risk patient, a patient with a C/T allelic expression is classified as a third highest risk patient and a patient with a CC allelic expression is classified as a lowest risk patient. The risk stratification method may further include identification of an abnormal expression or mutation/function of a gene product produced by CTCF binding site 6.
Claims
1. A method of risk stratification and treatment of a tumor that expresses Boris in a patient, the method comprising: a) detecting the genotype of a thymine/cytosine (T/C) single nucleotide polymorphism (SNP) where the T/C SNP is within a binding site for boris or CTFC in a sample from the patient, wherein the T/C SNP is rs10732516 or within 500 base pairs of rs10732516, wherein the genotype of the T/C SNP is optionally detected using a surrogate SNP maker that is in linkage disequilibrium with the T/C SNP and is within 500 base pairs of rs10732516; wherein a TT or TC genotype of the T/C SNP is detected; and b) if the patient is heterozygous with one thymine allele and one cytosine allele, determining which allele is the maternal allele and which allele is the paternal allele; wherein: i) the detected genotype of the polymorphism is TT, the patient is classified as a highest risk patient, and the tumor is treated by surgical excision or chemotherapy; or ii) the detected genotype of the of the polymorphism is TC, the C allele is determined to be the maternal allele, the patient is classified as a high risk patient, and the tumor is treated by surgical excision or chemotherapy.
2. The method of claim 1, wherein the binding site is within 350 base pairs of rs10732516.
3. The method of claim 1, wherein the binding site is within 150 base pairs of rs10732516.
4. The method of claim 1, wherein the binding site is between and including rs534219523 and rs2107425.
5. The method of claim 1, wherein the binding site is between and including rs10732516 and rs2107425.
6. The method of claim 1, wherein the binding site is between and including rs10732516 and rs534219523.
7. The method of claim 1, wherein determining which allele is the maternal allele and which allele is the paternal allele in a heterozygous genotype at the binding site, with one thymine allele and one cytosine allele, comprises determining whether the cytosine is methylated; whereby: when the cytosine is not methylated the C allele is determined to be a maternal allele; and when the cytosine is methylated the C allele is determined to be a paternal allele.
8. The method of claim 7, wherein determining whether the cytosine is methylated comprises spectroscopy of the patient's DNA.
9. The method of claim 7, wherein determining whether the cytosine is methylated comprises bisulfite conversion and quantitative methylation sensitive pyrosequencing.
10. The method of claim 7, wherein determining whether the cytosine is methylated comprises directly sequencing parental DNA.
11. The method of claim 1 wherein the tumor is breast cancer.
12. The method of claim 1 wherein the tumor is ovarian cancer.
13. The method of claim 1 wherein the tumor is testicular cancer.
14. The method of claim 1 wherein the tumor is liver cancer.
15. The method of claim 1 wherein the tumor is lung cancer.
16. The method of claim 1 wherein the tumor is brain cancer.
17. The method of claim 1 wherein the tumor is a melanoma.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the principles of the invention.
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DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
(19) Corresponding reference characters indicate corresponding parts throughout the several views of the figures. The figures represent an illustration of some of the embodiments of the present invention and are not to be construed as limiting the scope of the invention in any manner. Further, the figures are not necessarily to scale, some features may be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
(20) As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Also, use of “a” or “an” are employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.
(21) Certain exemplary embodiments of the present invention are described herein and are illustrated in the accompanying figures. The embodiments described are only for purposes of illustrating the present invention and should not be interpreted as limiting the scope of the invention. Other embodiments of the invention, and certain modifications, combinations and improvements of the described embodiments, will occur to those skilled in the art and all such alternate embodiments, combinations, modifications and improvements are within the scope of the present invention.
(22) This application incorporates by reference in its entirety, the following publication: Brent Schultz, Xiaopan Yao, Yanhong Deng, Milton Waner, Christopher Spock, Laura Tom, John Persing, Deepak Narayan, (2015) A Common Polymorphism Within The IGF2 Imprinting Control Region Is Associated with Parent of Origin Specific Effects in Infantile Hemangiomas, PLOS ONE|DOI:10.1371/journal. pone.0113168
Materials and Methods
(23) This article describes a study that involved analyzing post excisional tissue from surgical candidates. The decision to operate was in no way influenced by the study. Clinical data was gathered retrospectively from this same group. All surgical candidates had clinical measurements available for analysis. All samples and clinical data were collected in accordance with the approved HIC protocol (#0507000430) as reviewed by the Yale University Medical School IRB. This protocol was approved specifically for this study. Written consent was obtained from each patient's legal guardian prior to surgery. All data obtained including clinical measurements were stored in a de-identified format.
(24) Specimen Collection:
(25) Please refer to the Master Data Table for details, as shown in
(26) Master Data Table. As shown in
(27) In total 34 samples were genotyped for a polymorphism within CTCF BS6 and parental contributions were determined for heterozygotes (see
(28) DDNA Preservation and Extraction
(29) Immediately following tissue resection, DNA was isolated using the Qiagen DNeasy Tissue Mini Kit according to the manufacturer's protocol. Only samples with an A260/A280 measurement of 1.8 or above that ran as a single band on the gel were further analyzed.
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(31) RNA Preservation and Extraction
(32) Immediately following tissue resection, 100-500 mg of tissue was stored in Quiagen RNA Later solution according to the manufacturer's protocol. RNA was extracted via liquid nitrogen powder homogenization using Invitrogen Trizol reagent according to the standard protocol. 10 μg of total RNA from each sample was then treated with DNase Qiagen mini-elute columns according to manufacturer's specifications. RNA integrity was then assessed using Agilent bioanalyzer 2100 (provided as a service of the Keck Center at Yale University.) Those samples with 18 s/28 s ratio of 1.8 or greater were converted into cDNA using the ABI 4368813 cDNA archive kit. All samples were then stored at −80 degrees C.
(33) Quantitative rtPCR for CTCF, BORIS, H19 and IGF2
(34) Nineteen IH samples with suitable RNA, as previously specified, were subjected to fluorescent quantitative RT-PCR using ABI Taqman primers that were previously validated by the manufacturer and spanned intron exon boundaries. For reasons of sample scarcity, not all samples were subjected to each assay (See
(35) Western Analysis
(36) 24 samples were subjected to Western analysis. As this process is tissue intensive, younger samples such as #21 and #23 could only be used for this analysis as insufficient tissue was left for further processing. Other samples were selected biased toward analyzing those samples with transcriptional data in order to compare transcriptional phenomena to translational. However, as the analysis proceeded, presentation gels were constructed to demonstrate key transition points in CTCF and BORIS translation in samples that had not been treated with steroids. Briefly, 50 mg of each sample were processed with a rotary homogenizer in 200 ml of RIPA lysis buffer. After centrifugation lysates were created using a standard beta-mercapto-ethanol with SDS. PAGE was performed with 36μg of protein per well in NuPage 10% Bis-Tris precast gels inMOPS buffer at 100 volts. PAGE separated proteins were then transferred for two hours to a PVDF membrane (Bio-Rad) in a standard transfer buffer at 100 mAmps. Anti BORIS antibody (Abcam 18337) was used at 1/5000 dilution in TBST with 5% cows milk overnight. Two concentrations of anti-CTCF were used—1:10,000 and 1:5,000—to better visualize late and early rises in CTCF protein (see
(37) Bisulfite Methylation Analysis Using Quantitative Pyrosequencing
(38) This method was first described by Grunau et al and Dupont et al. Incomplete bisulfite conversion was detected by designing amplicons that contained at least 1 unmethylated cytosine. Primer bias was controlled for by establishing methylation curves of 100% methylated DNA titrated against known amounts of whole genome amplified PCR products that, by definition, are unmethylated. These methylation curves allow experimental samples to be calibrated against known standards. Primers for Exon 9, the H19 promoter and CTCFBS6 as well as the bisulfite-converted sequences they. The presence of an A/G polymorphism, approximately 130 base pairs downstream of CTCF BS6 leads to primer bias and distorts the absolute methylation values of CTCF BS6, Tost et al.
(39) Deducing Parental Contributions of Alleles at CTCF BS6
(40) All samples were subjected to direct sequencing of CTCF BS6 containing the polymorphism rs10732516. The DNA samples were subjected in parallel to methylation sensitive pyrosequencing of the same polymorphism; please see the section titled “Specimen Collection” for further details. Comparing these results allows each parental contribution to be deduced, see
(41) As shown in
(42) Genomic Southern Analysis for the H19 Promoter
(43) Eighteen were analyzed at a CLIA certified molecular diagnostics laboratory where this assay is performed as a clinical test for Beckwith-Wiedemann Syndrome. The assay is originally described by Debaun et al. Norms for this test were previously established with 30 normal controls at 55% methylation with a standard deviation of 5%. All samples were run with a normal and Beckwith-Wiedemann control. The assay exploits a CCCGGG site in the H19 promoter that is cut by the methylation sensitive restriction enzyme Pst1.
(44) Statistical Analysis
(45) Descriptive statistics were used to present patient characteristics. The difference in expression of IGF2 transcript across the three developmental stages of IH was evaluated using a Kruskal-Wallis test. To evaluate if the relative amount of CTCF compared to BORIS transcript changes predictably over time, change point analysis was performed. Change point analysis indicates the likelihood that a change in transcript expression occurred in the sample population by confidence level and a confidence interval regarding when those changes occur. The % CTCF [CTCF/(CTCF+BORIS)×100] was used to develop a change point model that was then compared against clinical staging and IGF2 expression in the sample population. A full explanation of the methods used, as well as a shareware change-point analyzer is presented as an online resource: Taylor, Wayne A. (2000), “Change-Point Analysis: A Powerful New Tool For Detecting Changes,” (http://www.variation.com/cpa/tech/changepoint.html.) To evaluate the association of IGF2 transcript and the relative amounts of CTCF, a linear regression model was fitted, with the % CTCF and age as covariates. The correlation and partial correlation were also calculated. Partial correlations indicate what percentage of variance in IGF2 can be explained by CTCF % alone. Analysis of the covariance model (ANCOVA) was fitted to examine if the correlation between the IGF2 transcript and the difference between CTCF and BORIS varied by the paternal genotype at CTCF BS6, once adjusted by age.
(46) Results Master Data Table
(47) In total, 40 samples were analyzed on a molecular basis. A description of basic demographics, with genotypes at CTCF BS6 and transcript expression values for IGF2, H19, CTCF and BORIS with correlative methylation data was compiled. Please see
(48) Expression of IGF2, CTCF and BORIS
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(51) IGF2 transcription differed significantly by clinical stages (p<0.0001, Kruskal-Wallis test). Plateau stage lesions expressed significantly higher levels of IGF2 than proliferating (p=0.0081, Wilcoxon rank sum test) and involuted samples (p=0.02). Involuted hemangiomas expressed the lowest levels of IGF2, approximately 6× lower than their proliferating counterparts (p=0.01).
(52) To potentially explain the changes in IGF2 transcription, quantitative RT-PCR was performed for CTCF and BORIS. CTCF and BORIS are co-expressed in all samples. However, the percentage of CTCF transcript compared to total CTCF and BORIS in a given sample [CTCF/(CTCF+BORIS)×100] varied significantly over developmental time (
(53) As described herein, a reduction, especially a rapid reduction, in the % CTCF, as expressed in
(54) As shown in
(55)
(56) Western analysis of CTCF and BORIS confirms and expands upon the transcript data (
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(58) The CTCF to BORIS transcript difference (C−B) predicts IGF2 transcription according to the paternal allele at CTCF BS6. This study utilizes existing technologies: Direct sequencing of the known polymorphism of CTCF BS6 (rs10732516) with a previously described methylation assay for CTCF BS6. Applying these two assays in a novel manner (see
(59) IGF2 mRNA is demonstrated to be inversely related to CTCF and positively correlated to BORIS transcripts when plotted against % CTCF (
(60) By using the difference between CTCF and BORIS (C−B) rather than the % CTCF, this relationship can be differentiated by the paternally contributed allele at CTCF BS6 (
(61) H19 transcript levels correlate positively with CTCF mRNA according to the maternally contributed allele at CTCFBS6. After age adjustment, CTCF transcript levels alone correlated positively with H19 transcription but only when separated by maternal genotype ((p=0.0150,
(62) It remains a possibility that the maternal allele effect may be steroid treatment driven as more samples with the maternal T allele were treated with steroids than the maternal C allele. This potential bias was investigated with an odds ratio calculation sorting steroid treatment according to maternal genotype. The odds ratio suggested that maternal T samples were more likely to be treated with steroids but this result did not reach statistical significance. However, it is acknowledged that this odds ratio may have become statistically in a larger sample size; the effect was not great enough to significantly bias the sample size.
(63) CTCF transcript levels alone correlate with demethylation of the H19 Promoter. All IH samples tested demonstrated significant hypomethylation at the H19 promoter compared to matched patient blood controls (
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(65) Multiple imprinted sites within the IGF2/H19 locus are abnormally methylated in IH compared to matched control blood.
(66) It remains a formal possibility that the normalization of CTCF to BORIS ratios, as well as decreased IGF2 transcription, in involuting and involuted samples is not due to an intracellular phenomenon but rather the incremental replacement of abnormal IH tissue (vascular stroma) with normal tissue (fat.) Thus, the results presented are the product of tissue heterogeneity. It is acknowledged that IH lesions transform from a vascular tumor into a fibrofatty residuum; therefore, the transitional phases are by definition composed of heterogeneous cell populations. However, no evidence was observed that the fibrofatty residuum of an involuted IH represents “normal” tissue. To the contrary, many of the methylation abnormalities discovered by this study are either stable or progressive from early to late clinical stages. For instance, the H19 promoter is significantly demethylated in all IH samples (see
(67) CTCF BS6 Genotypes Correlate with Clinical Outcomes
(68) Mechanisms aside, parent of origin specific effects are demonstrated at the molecular level regarding expression patterns of both IGF2 and H19. However, the question remains whether these molecular phenotypes may translate into clinically significant growth patterns.
(69) See
(70) As shown in
(71) TABLE-US-00001 TABLE 1 Allelic Expression Failure of Steroids Non-Failure of Steroids TT 7 2 Non-TT 5 15
(72) The results of this analysis shows that the type of allelic expression can be used to predict the effectiveness of Cortical steroid treatment. The odds ratio from this stud is 10.5 that the TT group will fail steroids, with a sensitivity of 58.33% (95% CI 27-84%) and a specificity of 88.33% (95% CI 63-98%). The failure of steroids is defined in this analysis as the patient requiring surgical treatment despite the treatment with the medication, cortical steroids.
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(74) The association between tumor size and age (days) are significantly different among these four genotypes (separating heterozygotes by their respective parental contributions) CC, C/T, T/C, TT (p=0.0162, ACOVA.) The most impressive growth phenotype was exhibited by homozygous T samples reaching an average of 7.8 cm before excision (
(75) TABLE-US-00002 TABLE 2 CLINICAL TABLE OF ULCERATION BY TT AND NON-TT GENOTYPE Retrospectively collected results with associated descriptive statistics: TT Lesions have a significantly higher associated odds ratio for ulceration. This proposed clinical test may be most useful in ruling out the chance of ulceration early in the disease course as sensitivity and negative predictive value are high. A larger prospecive study is warranted. Ulcerated Not Ulcerated TT 6 3 Non TT 0 20 Sensitivity = 100% Specificity = 89.96% Positive Predictive Value = 66.67% Negative Predicitve Value = 100% Odds Ratio = 76.1 95% Cl = 3.4-1676 P = 0.006
(76) TT Lesions Have a Significantly Higher Associated Odds Ratio for Ulceration. This proposed clinical test could be most useful in ruling out the chance of ulceration early in the disease course as sensitivity and negative predictive value are high. A larger prospective study is warranted.
(77) Lastly, size is a highly significant clinical outcome when studying IH. However, of similar importance is ulceration. Once an IH ulcerates, it is usually painful for the patient and is given to bleeding which can be clinically significant. Ulceration is usually a marker of rapid disease progression and heralds an escalation of care. This can entail the institution of laser therapy, pharmacologic intervention or surgical excision. Not surprisingly, ulceration alone can prompt surgical treatment regardless of size or location of the lesion. To study the risk of ulceration an odds ratio calculation was performed comparing TT and non-TT lesions. The TT lesions had an odds ratio of 76.1 for ulceration p=0.006 (Table 2). Although this is a small sample cohort preliminary specificity was performed, sensitivity and positive and negative predictive value calculations (Table 2). These early results suggest the highest clinical usefulness of the proposed test in ruling out potential future ulceration. Although encouraging, these results will need to be corroborated prospectively in a larger cohort.
(78) It will be apparent to those skilled in the art that various modifications, combinations and variations can be made in the present invention without departing from the spirit or scope of the invention. Specific embodiments, features and elements described herein may be modified, and/or combined in any suitable manner. Thus, it is intended that the present invention cover the modifications, combinations and variations of this invention provided they come within the scope of the appended claims and their equivalents.
(79) The following references are hereby incorporated by reference in their entirety:
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