Method of Determining Disease State Risk
20220034895 · 2022-02-03
Inventors
Cpc classification
A61K31/202
HUMAN NECESSITIES
G01N33/57484
PHYSICS
G01N2800/102
PHYSICS
G01N2560/00
PHYSICS
G01N33/92
PHYSICS
International classification
Abstract
A method for determining colorectal cancer risk includes obtaining a blood sample of the subject, isolating serum or EDTA plasma from the blood sample, analyzing the serum or EDTA plasma to determine plasma levels of very long chain dicarboxylic acid (VLCDCA 28:4), comparing the determined plasmas level of VLCDCA 28:4 of the subject with a predetermined range of plasma levels of VLCDCA 28:4 of diagnosed subjects having colorectal cancer, and determining a colorectal cancer risk exists when the determined plasma level of VLCDCA 28:4 is within the predetermined range of plasma levels of VLCDCA.
Claims
1. A method of determining disease state risk in a subject for a disease state selected from the group consisting of kidney cancer, colorectal cancer, head and neck cancer, rheumatoid arthritis, and combinations thereof, the method comprising: isolating serum or EDTA plasma from a blood sample; determining a plasma level of VLCDCA 28:4 from the isolated serum or EDTA plasma; comparing the determined plasma level of VLCDCA 28:4 from the isolated serum of EDTA plasma with a predetermined range of VLCDCA 28:4 plasma levels, the predetermined range of VLCDCA 28:4 plasma levels previously determined from multiple subjects not diagnosed as having the disease state; and determining the disease state risk exists when the determined plasma level of VLCDCA 28:4 from the isolated serum or EDTA plasma is at least 25% lower than the predetermined range of VLCDCA 28:4 plasma levels.
2. The method of claim 1, where the determined plasma level of VLCDCA 28:4 from the isolated serum or EDTA plasma is at least 50% lower than the predetermined range of VLCDCA 28:4 plasma levels.
3. The method of claim 1, where the disease state is colorectal cancer and the determined plasma level of VLCDCA 28:4 from the isolated serum or EDTA plasma is at least 62% lower than the predetermined range of VLCDCA 28:4 plasma levels.
4. The method of claim 1, where the disease state is colorectal cancer and the determined plasma level of VLCDCA 28:4 from the isolated serum or EDTA plasma is at least 68% lower than the predetermined range of VLCDCA 28:4 plasma levels.
5. The method of claim 1, where the disease state is colorectal cancer and the determined plasma level of VLCDCA 28:4 from the isolated serum or EDTA plasma falls within a predetermined range of VLCDCA 28:4 plasma levels corresponding to a diagnosed active disease state.
6. The method of claim 1, where the disease state risk is determined to exist, the method further comprising: administering to the subject an amount of a very-long chain dicarboxylic acid sufficient to increase the plasma levels of VLCDCA 28:4 in the blood of the subject.
7. The method of claim 6, where the very-long chain dicarboxylic acid includes a straight chain group including from 28 to 36 carbons and from 1 to 4 double bonds.
8. The method of claim 7, where the very-long chain dicarboxylic acid is a compound having the formula:
HOOC—(CH.sub.2).sub.4—CH═CH—CH.sub.2—CH═CH—CH.sub.2—CH═CH—CH.sub.2—CH═CH—(CH.sub.2).sub.11—COOH.
9. The method of claim 6 7, where the very-long chain dicarboxylic acid is an ester of the very-long chain dicarboxylic acid of claim 8.
10. The method of claim 6, where the very-long chain dicarboxylic acid is administered to the subject until an at least 8% increase in circulating VLDCA 28:4 is observed.
11. The method of claim 6, where the very-long chain dicarboxylic acid is administered to the subject until an at least 15% increase in circulating VLDCA 28:4 is observed.
12. The method of claim 6, where the blood sample is obtained through venipuncture.
13. A method of validating the structure of a 28 to 36 carbon very-long chain dicarboxylic acid, the method comprising isolating serum or EDTA plasma from a blood sample; storing the serum or EDTA plasma in a low temperature environment; mixing about 1 milliliter (mL) of methanol comprising 1 nanomole of [2H28] dicarboxylic acid 16:0 with the isolated serum or EDTA plasma; mixing about 1 mL of distilled water and about 2 ml of tert-butyl methylether with the isolated serum or EDTA plasma; separating an organic layer from the mixture; drying the organic layer; dissolving the dried organic layer in a combination of isopropanol, methanol, chloroform, and ammonium acetate; performing mass spectrometry on the dissolved organic layer; and quantifying anions of dicarboxylic acid using negative ion electrospray ionization to validate the dicarboxylic acid 28:4 structure
14. The method of claim 13, where the combination of isopropanol, methanol, and chloroform is in a ratio of 4:2:1.
15. The method of claim 13, where the ammonium acetate is present in the combination at an about 15 millimolar concentration.
Description
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0038] A wide variety of additional embodiments will be more readily understood and appreciated through the following detailed description of the example embodiments, with reference to the accompanying drawings in which:
[0039]
[0040]
[0041]
[0042]
[0043]
[0044]
[0045]
[0046]
DETAILED DESCRIPTION OF THE INVENTION
[0047] A decrease in the prevalence of certain long-chain hydrocarbon biomarker masses in the blood of a human is often a prelude to cancer. Therefore, screening for low levels of specific identified long-chain hydrocarbon biomarkers has potential as a useful tool for early identification of cancer risk and as an indicator for additional cancer testing. In particular, heightened cancer risk or incipient cancer (for example, colorectal cancer or pancreatic cancer) is correlated with a reduction in relation to a non-disease control in very-long chain dicarboxylic acids (VLCDCAs) with between 28 and 30 carbon atoms, with between 0 and 1 hydroxy groups, and between 1 and 4 double bonds as well as with VLCDCAs with between 32 and 36 carbon atoms, with 1 or 2 hydroxy groups, and between 1 and 4 double bonds.
[0048] One particular very-long chain dicarboxylic acid (VLCDCA) with 28 carbons and 4 double bonds has potential as a diagnostic marker and as a supplement to provide protection against cancer development. This VLCDCA (hereinafter identified as VLCDCA 28:4) has formula (I):
HOOC—(CH.sub.2).sub.4—CH═CH—CH.sub.2—CH═CH—CH.sub.2—CH═CH—CH.sub.2—CH═CH—(CH.sub.2).sub.11—COOH (I).
[0049] Lipid extracts within human plasma or serum which have monitored decreases in a number of molecules having atomic masses between 444 and 555 amu in patients diagnosed with pancreatic or colorectal cancer are identified as VLCDCAs. With regard to a molecular anion having an atomic mass of 445.3323 amu., this lipid is identified, for the first time, as VLCDCA 28:4. Conversion of VLCFAs to dicarboxylic acids first involve ω-oxidation of the fatty acid by microsomal CYP4F, followed by conversion to an aldehyde via alcohol dehydrogenase, and the final conversion to a VLCDCA by CYP4F or by fatty aldehyde dehydrogenase. The present inventive concept includes a characterization of VLCDCAs of up to 36 carbons in length.
[0050] VLCDCAs up to 36 carbons in length may be used as lipid biomarkers of various cancers, such as for example colorectal, ovarian, prostate, and pancreatic cancers. The present general inventive concept provides an accurate identification of the VLCDCA biomarker masses between 444 and 555 amu, which have been monitored to decrease in number within lipid extracts of human plasma or serum from patients diagnosed with colorectal cancer and pancreatic cancer. Pursuant to the present inventive concept, these lipid biomarkers are identified as VLCDCAs with 1 to 4 double bonds and 0, 1, or 2 hydroxy substitutions.
[0051]
[0052]
[0053] A method of validating the dicarboxylic acid 28:4 structure also is disclosed. The method includes derivatization of the two carboxylic groups in VLCFA 28:4 by using [.sup.2H.sub.4]taurine and trimethylsilyl diazomethane. This validation method includes obtaining blood samples collected by venipuncture and then isolating a sample of either serum or ethylenediaminetetraacetic acid (EDTA) plasma from the blood samples. The sample of serum and/or the EDTA plasma may, in certain embodiments, be stored in a low temperature environment (e.g. a refrigerator) or frozen to limit degradation of the sample prior to analysis.
[0054] The sample of approximately 100 microliters of serum and/or EDTA plasma may be mixed with 1 milliliter (mL) of methanol containing 1 nanomole of [.sup.2H.sub.28] dicarboxylic acid 16:0, of the type supplied, for example, by CDN Isotopes, 88 Ave. Leacota, PointeClaire, QC, H9R 1H1, to form a sample mixture. Next, 1 milliliter of distilled water and 2 milliliters of tert-butyl methylether are added to the sample mixture. The sample mixture is then agitated in an organic solvent to extract the lipid fraction. For example, the sample mixture may be agitated by shaking at a high speed (e.g., setting 9 of the Fisher Multitube Vortex) for approximately 30 minutes at room temperature. The sample mixture is then settled to separate an organic upper layer from the remainder of the sample. The sample mixture may then be transferred to a test tube and centrifuged at approximately 3000 times gravity at room temperature for approximately 10 minutes.
[0055] In one embodiment, upon the above-discussed settling of the sample mixture, approximately 1 milliliter of the upper organic layer is transferred to a 1.5 milliliter microtube and dried, for example by centrifugal vacuum evaporation, prior to dissolution of the dried upper organic layer portion in a mixture of isopropanol, methanol, and chloroform, at a ratio of 4:2:1, respectively, containing about 15 millimolar (mM) ammonium acetate. High resolution (e.g., 140,000 at 200 atomic mass unit) data acquisition, with sub-millimass accuracy, is then performed on the samples via direct infusion with an orbitrap mass spectrometer, for example, of the type manufactured and sold by Thermo Scientific under the trademark “Q Exactive™”. However, other types or models of mass spectrometer may be used. In embodiments in which multiple samples are processed according to the method simultaneously, in order to minimize ghost effects from one sample to the next, the input lines to the orbitrap mass spectrometer may be washed using methanol and a mixture of hexane and ethyl acetate, in a ratio of 3:2, respectively, between samples. Then, in negative ion electrospray ionization, the anions of dicarboxylic acid are quantitated, and from the acquired high-resolution dataset, the data may be reduced to provide a listing of VLCDCA, as illustrated in
[0056] Validation of two carboxylic groups in VLCFA 28:4 was obtained by sequential derivatization of one carboxylic group with [.sup.2H.sub.4]taurine and methylation of the second carboxylic group with trimethylsilyl diazomethane. The validation method includes adding approximately 1 milliliter of dried lipid extracts to 50 μL of 2-chloro-1-methypyrinium iodide (15.2 mg per 10 milliliters of acetonitrile and 16.4 μL of trimethylamine). The samples are heated at 30° C. with shaking for 15 minutes, followed by the addition of 50 μL of [.sup.2H.sub.4]taurine (5 mg in 900 μL of distilled water and 100 μL of acetonitrile). The samples are heated at 30° C. with shaking for another 2 hours before being dried by vacuum centrifugation. Next, 100 μL of 2-propanol and 20 μL of trimethylsilyl diazomethane (2 M in hexane) are added and the samples heated at 30° C. with shaking for 30 minutes. Next 20 μL of glacial acetic acid is added to consume any remaining trimethylsilyl diazomethane. The samples are then dried by vacuum centrifugation. The mixture is then subjected to dissolution in a mixture of isopropanol, methanol, and chloroform, in ratios of 4:2:1, respectively, containing approximately 15 mM of ammonium acetate.
[0057] The mixture is analyzed with negative ESI (140,000 resolution) to monitor the anion of the derivatized lipids. This involves the addition of 111.02931 ([.sup.2H.sub.4]taurine) and 14.01565 (trimethylsilyl diazomethane) amu yielding a product of 571.3845 (446.33960+111.02931+14.01565) and an anion of 570.3772, which is monitored with 0.53 ppm mass error (
[0058] In the case of dicarboxylic acids containing hydroxy functional groups, in various embodiments, the lipids first undergo sequential derivatization of one carboxylic group with [.sup.2H.sub.4]taurine and methylation of the second carboxylic group with trimethylsilyl diazomethane. Next, the hydroxyl groups are derivatized with [.sup.2H.sub.6]acetic anhydride. Specifically, the two carboxylic acid functions are derivatized as described above. The samples are then dried and 75 μL of pyridine and 75 μL [.sup.2H.sub.6]acetic anhydride added. The samples are heated at 60° C., with shaking, for 1 hour and dried by vacuum centrifugation prior to dissolution in a mixture of isopropanol, methanol, and chloroform (4:2:1) containing 15 mM ammonium acetate. In the case of dihydroxy VLCDCA 36:2 (See
[0059] In alternative example embodiments, the data may be reduced simply as a ratio of a peak area of an endogenous lipid to a peak area of a stable isotope internal standard. However, the present general inventive concept is not limited thereto. That is, in alternative example embodiments, standard curves may be constructed for absolute quantitation, when analytical standards are available. In further example embodiments, VLCFAs may be quantitated by tandem mass spectrometry (MS.sup.2) or various other mass spectrometry techniques, including, but not limited to, unit resolution mass spectrometry with a triple quadrupole instrument. However, the present general inventive concept is not limited thereto. In yet further example embodiments, various conventional chromatographic methods such as liquid chromatography, capillary zone electrophoresis, and supercritical fluid chromatography may be used as alternatives to direct infusion. However, the present general inventive concept is not limited thereto.
[0060]
[0061]
[0062] A reduction of VLCDCA 28:4 by approximately 25% in relation to a control indicates active or a susceptibility to one or more of the conditions kidney cancer, colorectal cancer, head and neck cancer, and rheumatoid arthritis. A reduction of VLCDCA 28:4 by approximately 50% in relation to the control is a stronger indicator of active or a susceptibility to one or more of the conditions kidney cancer, colorectal cancer, head and neck cancer, and rheumatoid arthritis. A reduction of VLCDCA 28:4 by approximately 62% in relation to the control is an indicator of active colorectal cancer or a susceptibility to colorectal cancer. A reduction of VLCDCA 28:4 by approximately 68% or more in relation to the control is a stronger indicator of active colorectal cancer or a susceptibility to colorectal cancer.
[0063] Clinically, decrements in the biomarker masses between 444 and 555 have been detected prior to cancer development. In addition, these biomarker masses are not restored post-surgery to remove identified cancerous tissues, which suggests that these biomarker masses are not derived from the cancerous tissues and may represent intrinsic chemoprotective factors.
[0064] Supplements of these factors, including VLCDCA having from 28 to 36 carbon atoms, such as VLCDCA 28:4, may be provided to people who have been identified as having a disease state risk of developing certain types of cancers or inflammatory disorders to provide protection against cancer or inflammatory disorder development. In certain instances, purified fractions of these identified lipids from human plasma have been observed to possess both anti-inflammatory and anti-proliferative properties. The VLCDAs may be administered to the subject until an at least 8% increase in circulating VLDCA 28:4 is observed. Preferably, the VLCDAs may be administered to the subject until an at least 15% increase in circulating VLDCA 28:4 is observed.
[0065] The identified lipid biomarker VLCDCA 28:4 is generated by a conversion of VLCFAs. This conversion first involves w-oxidation of the VLCFA 28:4 (VLCFA 28:4n6) by microsomal CYP4F, followed by conversion to an aldehyde via alcohol dehydrogenase, and the final conversion to VLCDCA 28:4n6 by CYP4F or by fatty aldehyde dehydrogenase. While VLCDCAs of up to 26 carbons have been previously reported, the present method provides a characterization of VLCDCAs of up to 36 carbons in length.
[0066] Methods of quantifying serum or plasma levels of the identified lipid biomarker VLCDCA 28:4 within a subject may be used to monitor these lipids as risk factors for developing a plurality of cancers, including, but not limited to, colorectal, kidney, prostate, and pancreatic cancers. For example, in one embodiment, VLCFAs may be quantitated by MS2 on various other mass spectrometers including unit resolution mass spectrometry with a triple quadrupole instrument. In addition, chromatographic methods may also be used as alternatives to direct infusion methods, which may include liquid chromatography, capillary zone, electrophoresis, and supercritical fluid chromatography. However, the present general inventive concept is not limited thereto.
[0067]
[0068]
Method of Treating: Colorectal Cancer
[0069] In example embodiments, the present general inventive concept provides a method of treating a subject having colorectal cancer. In alternative example embodiments, the present general inventive concept also provides a chemopreventive agent and a method of treating a subject having low circulating levels of VLCDCAs with the chemopreventive agent. The treatment method includes administering to the subject having colorectal cancer or low circulating levels of VLCDCAs a sufficient amount of VLCDCAs to increase the level of VLCDCAs circulating in the blood a compound according to the formula (I), a prodrug of (I), or an analog of (I):
HOOC—(CH.sub.2).sub.4—CH═CH—CH.sub.2—CH═CH—CH.sub.2—CH═CH—CH.sub.2—CH═CH—(CH.sub.2).sub.11—COOH (I)
[0070] However, the present general inventive concept is not limited thereto. That is, in other example embodiments, structural analogs of compound (I) and/or prodrug esters of compound (I) may also be developed to provide superior and/or improved bioavailability (BA).
Method of Treating: Pancreatic Cancer
[0071] In other example embodiments, the present general inventive concept provides a method of treating a subject having pancreatic cancer and as a chemopreventive agent in individuals with low circulating levels of VLCDCAs. The treatment method includes administering to the subject having pancreatic cancer or low circulating levels of VLCDCAs a sufficient amount of VLCDCAs to increase the level of VLCDCAs circulating in the blood a compound according to the formula (I), a prodrug of (I), or an analog of (I):
HOOC—(CH.sub.2).sub.4—CH═CH—CH.sub.2—CH═CH—CH.sub.2—CH═CH—CH.sub.2—CH═CH—(CH.sub.2).sub.11—COOH (I)
[0072] However, the present general inventive concept is not limited thereto. That is, in other example embodiments, structural analogs of compound (I) and/or prodrug esters of compound (I) may also be developed to provide superior and/or improved bioavailability (BA).
Method of Treating: Prostate Cancer
[0073] In alternative example embodiments, the present general inventive concept provides a method of treating a subject having prostate cancer and as a chemopreventive agent in individuals with low circulating levels of VLCDCAs. The treatment method includes administering to the subject having prostate cancer or low circulating levels of VLCDCAs a sufficient amount of VLCDCAs to increase the level of VLCDCAs circulating in the blood a compound according to the formula (I), a prodrug of (I), or an analog of (I):
HOOC—(CH.sub.2).sub.4—CH═CH—CH.sub.2—CH═CH—CH.sub.2—CH═CH—CH.sub.2—CH═CH—(CH.sub.2).sub.11—COOH (I)
[0074] However, the present general inventive concept is not limited thereto. That is, in other example embodiments, structural analogs of compound (I) and/or prodrug esters of compound (I) may also be developed to provide superior and/or improved bioavailability (BA).
[0075] Other VLCDCAs (listed in