CN113699239A

CN113699239A - Use of reagents for detecting biomarkers in the diagnosis of disease

Info

Publication number: CN113699239A
Application number: CN202111036549.2A
Authority: CN
Inventors: 杨承刚; 李雨晨; 刘乐凯
Original assignee: Qingdao Yangshen Biomedical Co Ltd
Current assignee: Qingdao Yangshen Biomedical Co Ltd
Priority date: 2021-09-06
Filing date: 2021-09-06
Publication date: 2021-11-26

Abstract

The invention discloses an application of a reagent for detecting a biomarker in diagnosing diseases, wherein the biomarker is the combination of CTSB and RPS27A, has better sensitivity and specificity for the diagnosis of endometrial cancer, can be used for the diagnosis (including early diagnosis) of endometrial cancer, and has important significance for improving the prognosis of patients with endometrial cancer and improving the survival rate of the patients with endometrial cancer.

Description

Use of reagents for detecting biomarkers in the diagnosis of disease

Technical Field

The invention belongs to the technical field of biomedicine, and particularly relates to application of a biomarker detection reagent in disease diagnosis, more particularly to application of a biomarker detection reagent in endometrial cancer diagnosis.

Background

More than 90% of uterine cancers are Endometrial Cancers (EC), which originate in the epithelium, the majority of the rest are mesenchymal, originating in the myometrium, a few Endometrial stromal cancers account for about 7% of all cancers in women, and the lifetime risk of acquiring Endometrial cancer in women is 2.5%. EC is one of three common malignant tumors of the female reproductive system, accounts for 20% -30% of the malignant tumors of the female reproductive system, and in recent years, the incidence rate of endometrial cancer shows a trend of obviously rising and gradually tends to be younger worldwide. EC, a highly prevalent malignancy of the female reproductive system, is found in postmenopausal women, where the major risk factor is the clinical presence of excess endogenous or exogenous estrogen without adequate progestogen antagonism.

Early discovery, early diagnosis, and early treatment are especially important to improve the quality of life of EC patients and to improve the prognosis of patients. Currently, there is no screening method, and clinical diagnosis is performed only under the guidance of gynecologists when clinical symptoms such as vaginal bleeding, vaginal drainage and lower abdominal pain are manifested, and the main diagnostic means for endometrial cancer are classified into imaging examination and endometrial biopsy and laboratory diagnosis:

1. imaging examination

Mainly used for preliminary judgment, and transvaginal ultrasonic examination is the most common noninvasive examination method. When the thickness of the endometrium is greater than 5mm, a biopsy of the endometrium is required. The abdominopelvic Magnetic Resonance (MRI) examination is commonly used in imaging examination, and can be identified with submucosal hysteromyoma, endometrial polyp, uterine sarcoma, cervical carcinoma and the like. The disadvantage is that some patients should not be examined by magnetic resonance, which belongs to contraindication and relative contraindication.

2. Endometrial biopsy

Endometrial biopsy is the definitive diagnosis of endometrial cancer and is mainly divided into segmental curettage and hysteroscopic location biopsy. The segmental curettage is to curette the tissue of the cervical canal first and then the uterine body, and the curettage is sent for examination. The nature, location and extent of involvement of the pathological changes are determined. The disadvantages are that false positive is easy to be caused, uterus can be drawn during operation, postoperative abdominal pain is possibly caused, and good anti-inflammatory treatment is needed to prevent infection.

3. Laboratory diagnostic method

The clinical detection markers most commonly used at present are sugar chain antigen CA125 and human epididymis protein 4(HE4), wherein, the serum CA125 is helpful for monitoring the clinical treatment effect of patients with extrauterine lesions, but for patients with peritonitis or radiation injury, the CA125 may be abnormally increased, and the CA125 of patients with isolated vaginal metastasis is not increased, so that the recurrence cannot be predicted in the absence of other clinical findings, and in addition, the sensitivity of CA125 and HE4 is low, and the patients cannot be effectively screened.

Therefore, finding a convenient, non-invasive, biopsy-free, highly sensitive and specific serological assay is essential to improve the quality of life of EC patients and to improve their prognosis.

Disclosure of Invention

The invention aims to: in view of the deficiencies of the prior art, reagents for detecting biomarkers are provided and applied to diagnosis of endometrial cancer, so as to determine whether a subject is an endometrial cancer patient or whether the subject is at high risk of endometrial cancer in an early, accurate, rapid and noninvasive manner.

In order to achieve the purpose, the invention adopts the following technical scheme:

in one aspect, the invention provides the use of a reagent for detecting a biomarker in a sample in the manufacture of a product for diagnosing endometrial cancer.

Further, the biomarkers were CTSB and RPS 27A.

Further, the reagent for detecting the biomarker in the sample comprises a reagent for detecting the mRNA expression level of the biomarker in the sample and a reagent for detecting the protein expression level of the biomarker in the sample.

Further, the agent is selected from: a primer that specifically amplifies the biomarker, a probe that specifically recognizes the biomarker, a binding agent that specifically binds to a protein encoded by the biomarker;

preferably, the binding agent comprises an antibody, antibody functional fragment, conjugated antibody that specifically binds to the protein encoded by the biomarker.

In another aspect, the invention provides an article of manufacture for use in diagnosing endometrial cancer.

Further, the product comprises reagents for detecting the biomarkers CTSB and RPS 27A.

Further, the reagents for detecting the biomarkers CTSB and RPS27A are selected from the group consisting of: primers that specifically amplify the biomarkers CTSB and RPS27A, probes that specifically recognize the biomarkers CTSB and RPS27A, binders that specifically bind to proteins encoded by the biomarkers CTSB and RPS 27A;

preferably, the binding agent comprises an antibody, functional fragment of an antibody, conjugated antibody that specifically binds to the proteins encoded by the biomarkers CTSB and RPS 27A.

Further, the product comprises a kit, a chip, test paper and a high-throughput sequencing platform;

preferably, the kit comprises a qPCR kit, an ELISA kit, an immunoblotting detection kit, a flow cytometry analysis kit, an immunohistochemical detection kit, an immunochromatography detection kit and an electrochemiluminescence detection kit.

In another aspect, the invention provides the use of a reagent for detecting a biomarker in a sample for the manufacture of a system for diagnosing endometrial cancer.

Further, the biomarkers were CTSB and RPS 27A.

Further, the reagent for detecting the biomarker in the sample comprises a reagent for detecting the mRNA expression level of the biomarker in the sample, and a reagent for detecting the protein expression level of the biomarker in the sample;

preferably, the agent is selected from: a primer that specifically amplifies the biomarker, a probe that specifically recognizes the biomarker, a binding agent that specifically binds to a protein encoded by the biomarker;

more preferably, the binding agent comprises an antibody, antibody functional fragment, conjugated antibody that specifically binds to the protein encoded by the biomarker.

In another aspect, the present invention provides a diagnostic system for endometrial cancer.

Further, the diagnostic system comprises:

a detection means: the detection means is for detecting the expression level of the biomarkers CTSB and RPS 27A;

a result judgment means: the result judging means is used for inputting whether the subject has endometrial cancer or the risk of endometrial cancer according to the result of the expression levels of the biomarkers CTSB and RPS27A detected by the detecting means;

preferably, the expression level of the biomarkers CTSB and RPS27A comprises the mRNA expression level of the biomarkers CTSB and RPS27A, the protein expression level of the biomarkers CTSB and RPS 27A.

Further, the detection component comprises a qPCR kit, an ELISA kit, an immunoblotting detection kit, a flow cytometry kit, an immunohistochemical detection kit, an immunochromatography detection kit, an electrochemiluminescence detection kit, a qPCR instrument, an ELISA detection device, an immunoblotting detection device, a flow cytometry device, an immunohistochemical detection device, an immunochromatography detection device and an electrochemiluminescence detection device;

the result judging component comprises an input module, an analysis module and an output module; an input module for inputting the expression levels of the biomarkers CTSB and RPS 27A; an analysis module for analysing whether the subject has endometrial cancer or a risk for endometrial cancer based on the expression levels of the biomarkers CTSB and RPS 27A; the output module is used for outputting the analysis result of the analysis module.

The invention also provides a method for diagnosing endometrial cancer.

Further, the method comprises the steps of:

(1) obtaining a sample of a subject;

(2) detecting the expression level of the biomarkers CTSB and RPS27A in a sample from the subject;

(3) correlating the measured expression levels of the biomarkers CTSB and RPS27A with the presence or absence of disease or the risk of disease in the subject;

(4) if the expression level of the biomarker CTSB is increased and the expression level of the biomarker RPS27A is decreased as compared to a normal control, then the subject is determined to have a predisposition to have endometrial cancer, or has had endometrial cancer, or the endometrial cancer is determined to have relapsed, or a patient with endometrial cancer is determined to have a poor prognosis.

The product for diagnosing endometrial cancer or the diagnostic system for endometrial cancer described in the present invention is directed to a sample of a subject which is a body fluid, tissue or faeces.

Further, the excrement comprises sputum, saliva, urine or feces;

further, the body fluid comprises blood, extracellular fluid, interstitial fluid, lymphatic fluid, cerebrospinal fluid, or aqueous humor;

further, the body fluid is blood;

further, the sample of the subject is blood.

The primers included in the products described in the present invention can be prepared by chemical synthesis, appropriately designed by referring to known information using methods well known to those skilled in the art, and prepared by chemical synthesis. The antibody in the product or diagnostic system described in the present invention may be an antibody or a fragment thereof of any structure, size, immunoglobulin class, origin, etc., as long as it binds to the target protein. The antibodies or fragments thereof included in the products of the invention may be monoclonal or polyclonal. An antibody fragment refers to a portion of an antibody or a peptide comprising a portion of an antibody that retains the binding activity of the antibody to an antigen. Antibody fragments may include F (ab ') 2, Fab', Fab, single chain fv (scfv), disulfide-bonded fv (dsfv) or polymers thereof, dimerized V regions (diabodies), or peptides containing CDRs. Antibodies can be obtained by methods well known to those skilled in the art. For example, mammalian cell expression vectors that retain all or part of the target protein or incorporate polynucleotides encoding them are prepared as antigens. After immunizing an animal with an antigen, immune cells are obtained from the immunized animal and myeloma cells are fused to obtain hybridomas. The antibody is then collected from the hybridoma culture. Finally, a monoclonal antibody against the marker protein can be obtained by subjecting the obtained antibody to antigen-specific purification using the marker protein or a portion thereof used as an antigen.

In the context of the present invention, "diagnosis of endometrial cancer" includes determining whether a subject has endometrial cancer, determining that a subject is at risk for endometrial cancer, determining whether a patient with endometrial cancer has relapsed, determining the prognosis for a patient with endometrial cancer.

The Gene IDs in NCBI for the biomarkers CTSB and RPS27A described in the present invention are as follows:

CTSB (cathepsin B) Gene ID in NCBI is 1508;

RPS27A (Ribosol protein S27a) has a Gene ID of 6233 in NCBI.

Drawings

Embodiments of the invention are described in detail below with reference to the attached drawing figures, wherein:

FIG. 1 is a diagram showing the expression of genes in a training set, wherein A is a diagram: CTSB, Panel B: RPS 27A;

FIG. 2 is a diagram showing the expression of genes in a validation set, wherein A is a diagram: CTSB, Panel B: RPS 27A;

FIG. 3 is a graph of ROC of genes in a training set, in which A is a graph: CTSB, Panel B: RPS27A, panel C: CTSB + RPS 27A;

FIG. 4 is a graph of ROC of genes in a validation set, in which A is a graph: CTSB, Panel B: RPS27A, panel C: CTSB + RPS 27A.

Detailed Description

In order to screen the biomarkers for diagnosing the endometrial cancer, sample data related to the endometrial cancer in a GEO database and a TCGA database are downloaded, gene expression profiles of the samples are comprehensively analyzed, genes which are remarkably and differentially expressed in two groups of a training set are screened, and the expression condition and the diagnosis efficiency of the differentially expressed genes in a verification set are further analyzed, so that the biomarkers suitable for diagnosing the endometrial cancer are found.

In the context of the present invention, the term "biomarker" as used refers to a compound, preferably a gene, which is differentially present (i.e. increased or decreased) in a biological sample from a subject or a group of subjects having a first phenotype (e.g. having a disease) compared to a biological sample from a subject or a group of subjects having a second phenotype (e.g. no disease). The term generally refers to the presence/concentration/amount of one gene or the presence/concentration/amount of two or more genes, and in particular embodiments of the invention, the biomarkers are CTSB and RPS 27A;

biomarkers can be differentially present at any level, but are typically present at levels that are increased by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 100%, at least 110%, at least 120%, at least 130%, at least 140%, at least 150%, or more; or generally at a level that is reduced by at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or 100% (i.e., absent), preferably the biomarker is statistically significant (P < 0.05).

In the context of the present invention, the term "sample" as used herein refers to a composition obtained or derived from a subject (e.g., an individual of interest) that comprises cells and/or other molecular entities to be characterized and/or identified, for example, according to physical, biochemical, chemical and/or physiological characteristics. For example, a sample refers to any sample derived from a subject of interest that is expected or known to contain the cellular and/or molecular entities to be characterized. Samples include, but are not limited to, tissue samples (e.g., tumor tissue samples), primary or cultured cells or cell lines, cell supernatants, cell lysates, platelets, serum, plasma, vitreous humor, lymph, synovial fluid, follicular fluid, semen, amniotic fluid, milk, whole blood, blood-derived cells, urine, cerebrospinal fluid, saliva, sputum, tears, sweat, mucus, tumor lysates, tissue culture fluids, tissue extracts, homogenized tissue, tumor tissue, cell extracts, and combinations thereof. As a preferred embodiment, the sample is selected from blood, serum, plasma, as another preferred embodiment, the sample is selected from tissue.

In the context of the present invention, the term "subject" as used refers to any animal, also to human and non-human animals. Non-human animals include all vertebrates, e.g., mammals, such as non-human primates (particularly higher primates), sheep, dogs, rodents (e.g., mice or rats), guinea pigs, goats, pigs, cats, rabbits, cattle, and any domestic or companion animal; and non-mammals, such as chickens, amphibians, reptiles, and the like. In a preferred embodiment, the subject is a human.

The invention provides a product for diagnosing endometrial cancer, which comprises a reagent for detecting the biomarker of the invention in a sample, and can comprise instructions for using the kit to judge whether a subject has endometrial cancer or is at risk of having endometrial cancer.

In one embodiment of the invention, the product may comprise a solid substrate such as a chip, slide, array or the like, having reagents capable of detecting and/or quantifying one or more sample biomarkers immobilized at predetermined locations on the substrate. As an illustrative example, the chip may be provided with reagents immobilized at discrete predetermined locations for detecting and quantifying the presence and/or concentration and/or amount of a biomarker in a sample. As described above, a reduced or increased level of the biomarker is found in a sample from a subject with endometrial cancer. The chip may be configured such that a detectable output (e.g. a change in colour) is provided only when the concentration of one or more of these biomarkers exceeds a threshold value selected or differentiated between the concentration and/or amount and/or level of expression of the biomarker indicative of a control subject and the concentration and/or amount and/or level of expression of the biomarker indicative of a patient suffering from or susceptible to endometrial cancer. Thus, the presence of a detectable output (e.g., a change in color) is immediately indicative of a significantly reduced level or a significantly elevated level of biomarker contained in the sample, indicating that the subject is suffering from or susceptible to endometrial cancer.

In the present invention, the biomarkers may be determined individually, or in one embodiment of the invention, they may be determined simultaneously, for example using a chip or bead-based array technology. The concentration of the biomarkers is then interpreted independently, for example using individual retention of each marker, or a combination thereof.

As the skilled person will be familiar with, the step of correlating biomarker levels with a certain likelihood or risk may be carried out and carried out in different ways. Preferably, the measured concentrations of the protein and one or more other markers are mathematically combined and the combined value is correlated with the underlying diagnostic problem. The determination of marker values may be combined by any suitable prior art mathematical method.

Preferably, the mathematical algorithm applied in the biomarker combinations is a logarithmic function. Preferably, the result of applying such a mathematical algorithm or such a logarithmic function is a single value. Such values can be readily correlated, in accordance with underlying diagnostic questions, with, for example, an individual's risk for endometrial cancer or with other diagnostic uses of interest that aid in the assessment of patients with endometrial cancer. In a preferred manner, such a logarithmic function is obtained as follows: a) classifying the individual into a group, e.g., a normal human, an individual at risk of endometrial cancer, a patient having endometrial cancer, etc.; b) identifying markers that differ significantly between these groups by univariate analysis; c) logistic regression analysis to assess independent difference values of the markers that can be used to assess these different sets; d) a logarithmic function is constructed to combine the independent difference values. In this type of analysis, the markers are no longer independent, but represent a combination of markers.

The logarithmic function used to correlate marker combinations with disease preferably employs algorithms developed and obtained by applying statistical methods. For example, suitable statistical methods are Discriminant Analysis (DA) (i.e., linear, quadratic, regular DA), Kernel methods (i.e., SVM), nonparametric methods (i.e., k-nearest neighbor classifiers), PLS (partial least squares), tree-based methods (i.e., logistic regression, CART, random forest methods, boosting/bagging methods), generalized linear models (i.e., logistic regression), principal component-based methods (i.e., SIMCA), generalized additive models, fuzzy logic-based methods, neural network-and genetic algorithm-based methods. The skilled person will not have problems in selecting a suitable statistical method to evaluate the marker combinations of the invention and thereby obtain a suitable mathematical algorithm. In one embodiment, the statistical method used to obtain the mathematical algorithm used in assessing endometrial cancer is selected from the group consisting of DA (i.e., linear, quadratic, regular discriminant analysis), Kernel method (i.e., SVM), nonparametric method (i.e., k-nearest neighbor classifier), PLS (partial least squares), tree-based method (i.e., logistic regression, CART, random forest method, boosting method), or generalized linear model (i.e., logarithmic regression).

The area under the subject's working characteristic curve (AUC) is an indicator of the performance or accuracy of the diagnostic protocol. The accuracy of a diagnostic method is best described by its Receiver Operating Characteristics (ROC). ROC plots are line graphs of all sensitivity/specificity pairs derived from continuously varying decision thresholds across the entire data range observed.

The clinical performance of a laboratory test depends on its diagnostic accuracy, or the ability to correctly classify a subject into a clinically relevant subgroup. Diagnostic accuracy measures the ability to correctly discriminate between two different conditions of the subject under investigation. Such conditions are, for example, health and disease or disease progression versus no disease progression.

In each case, the ROC line graph depicts the overlap between the two distributions by plotting sensitivity versus 1-specificity for the entire range of decision thresholds. On the y-axis is the sensitivity, or true positive score [ defined as (number of true positive test results)/(number of true positives + number of false negative test results) ]. This is also referred to as a positive for the presence of a disease or condition. It is calculated from the affected subgroups only. On the x-axis is the false positive score, or 1-specificity [ defined as (number of false positive results)/(number of true negatives + number of false positive results) ]. It is an indicator of specificity and is calculated entirely from unaffected subgroups. Because the true and false positive scores are calculated completely separately using test results from two different subgroups, the ROC line graph is independent of the prevalence of the disease to which the sample specimen relates. Each point on the ROC line graph represents a sensitivity/1-specificity pair corresponding to a particular decision threshold.

The technical solutions of the present invention are further illustrated by the following specific examples, which do not represent limitations to the scope of the present invention. Insubstantial modifications and adaptations of the present invention by others of the concepts fall within the scope of the invention.

Example 1 screening for biomarkers associated with endometrial cancer

1. Screening method

(1) Method for screening adopted data and preprocessing

In this example, data for screening biomarkers related to endometrial cancer are downloaded from a GEO database and a TCGA database, respectively, and "endometrial cancer" is used as a keyword to search for common gene expression data and complete clinical annotations of endometrial cancer, wherein chip data and clinical information of a GSE17025 data set are downloaded from the GEO database as a training set, and a sample amount is an endometrial cancer group: control group 91: 12; RNA-seq data and clinical information of endometrial cancer were downloaded from the TCGA database as validation set, sample size for endometrial cancer panel: control group 543: 35;

performing joint processing on raw data by using a fastp software double-end sequence automatic detection mode; the data is trimmed and quality controlled under the conditions that the threshold of the number of the lowest N bases is 5, the threshold of the minimum length of the reads is 15, the threshold of the quality of the bases is Q15, the percentage threshold of the low-quality bases is 40%, a sliding window is used for filtering by taking 4 bases as a unit, and the average threshold of the quality of the window is Q20; analyzing and using software default parameters, and outputting high-quality sequencing data for subsequent analysis; the analyzed clean data were aligned to the human reference genome version grch38.d1.vd1 using ICGC software, data from the TCGA database were normalized using the Voom method, data from the GEO database were normalized using the RMA method, genes were annotated by the Platform file, and de-duplication averages were combined.

(2) Analysis of differentially expressed genes in endometrial cancer

Analysis of differentially expressed genes for the GEO data and TCGA data for endometrial cancer described above was performed using the "limma" package (version 3.36.5) in the R software, where the screening criteria was adj<0.05、|log₂FC|>1, screening genes which are significantly and differentially expressed in GEO and TCGA respectively, and screening significant and differentially expressed genes which are shared by GEO and TCGA and have consistent expression trend for subsequent analysis and verification.

2. Screening results

The screening results are shown in fig. 1A-B, fig. 2A-B and table 1, and show that in the training set and the validation set, the biomarkers CTSB and RPS27A related to the present invention all exhibit significant differential expression in endometrial cancer, wherein the expression of CTSB is up-regulated in endometrial cancer, and the expression of RPS27A is down-regulated in endometrial cancer.

TABLE 1 expression of genes in training and validation sets

Example 2 validation analysis of diagnostic efficacy of the biomarkers obtained by screening

1. Verification analysis method

The AUC values, sensitivity and specificity of the biomarkers CTSB, RPS27A and CTSB + RPS27A screened in example 1, which exhibit significant differential expression between the control group and the endometrial cancer group, were analyzed by plotting a Receiver Operating Curve (ROC) using the R package "pROC", and the diagnostic efficacy thereof on endometrial cancer was judged. Wherein the amount of gene expression (Log) is used in assessing the diagnostic efficacy of the assay for a single biomarker CTSB, RPS27A for endometrial cancer₂Expression quantity), and selecting a point corresponding to the largest Youden index as a cutoff value of the point, wherein the optimal division threshold is determined by the point with the largest Youden index; in assessing the diagnostic efficacy of the combined biomarker CTSB + RPS27A on endometrial cancer, firstPerforming Logitics regression analysis on the gene CTSB + RPS27A, wherein in the Logitics regression analysis, the independent variable is CTSB + RPS27A, the dependent variable is the disease condition of endometrial cancer, the probability of whether each individual suffers from the endometrial cancer can be calculated through a fitted regression curve, and different probability partition thresholds are determined to obtain a prediction result. The optimal probability division threshold is determined by the point with the largest Youden index, and according to the determined probability division threshold, AUC values, sensitivity, specificity and the like of the CTSB + RPS27A detection in the training set and the verification set can be respectively calculated. The AUC values, sensitivities and specificities of the obtained CTSB, RPS27A and CTSB + RPS27A were analyzed to determine the diagnostic efficacy thereof.

2. Validating analysis results

The results of the diagnostic efficacy of CTSB, RPS27A in the training and validation sets, alone or in combination, are shown in fig. 3A-C, fig. 4A-C and table 2, and show that the CTSB + RPS27A combination shows higher diagnostic efficacy both in the training and validation sets, AUC values of 0.911, 0.833 respectively, sensitivity and specificity in the training set of 0.813, 0.917 respectively, sensitivity and specificity in the validation set of 0.803, 0.771 respectively, and are significantly better than the diagnostic efficacy of the individual genes CTSB, RPS 27A.

TABLE 2 diagnostic efficacy of genes in training and validation sets

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims, and such changes and modifications as fall within the scope of the invention as claimed.

Claims

1. Use of a reagent for detecting a biomarker in a sample for the manufacture of a product for diagnosing endometrial cancer, wherein the biomarker is CTSB and RPS 27A.

2. The use of claim 1, wherein the reagent for detecting a biomarker in the sample comprises a reagent for detecting the mRNA expression level of a biomarker in the sample, and a reagent for detecting the protein expression level of a biomarker in the sample.

3. Use according to claim 2, wherein said agent is selected from: a primer that specifically amplifies the biomarker, a probe that specifically recognizes the biomarker, a binding agent that specifically binds to a protein encoded by the biomarker;

4. An article for diagnosing endometrial cancer comprising reagents for detecting the biomarkers CTSB and RPS 27A.

5. A product according to claim 4, wherein the reagents for detecting the biomarkers CTSB and RPS27A are selected from: primers that specifically amplify the biomarkers CTSB and RPS27A, probes that specifically recognize the biomarkers CTSB and RPS27A, binders that specifically bind to proteins encoded by the biomarkers CTSB and RPS 27A;

6. The product of claim 4, wherein the product comprises a kit, a chip, a strip, a high throughput sequencing platform;

7. Use of a reagent for detecting a biomarker in a sample for the manufacture of a system for diagnosing endometrial cancer, wherein the biomarker is CTSB and RPS 27A.

8. The use of claim 7, wherein the reagent for detecting a biomarker in the sample comprises a reagent for detecting the mRNA expression level of the biomarker in the sample, a reagent for detecting the protein expression level of the biomarker in the sample;

9. A diagnostic system for endometrial cancer, said diagnostic system comprising:

10. The diagnostic system of claim 9, wherein the detection means comprises a qPCR kit, an ELISA kit, an immunoblot detection kit, a flow cytometric assay kit, an immunohistochemical detection kit, an immunochromatographic detection kit, an electrochemiluminescent detection kit, a qPCR instrument, an ELISA detection device, an immunoblot detection device, a flow cytometric assay device, an immunohistochemical detection device, an immunochromatographic detection device, an electrochemiluminescent detection device;