Use of lncRNA_AC005355.2 in preparation of diagnostic reagent for breast cancer

Abstract

The application belongs to the technical field of biological medicine, and particularly relates to application of lncRNA_AC005355.2 in preparation of a breast cancer diagnosis reagent. The lncRNA_AC005355.2 is used as a new molecular marker for detecting breast cancer, and the expression amount of the lncRNA_AC005355.2 in Luminal breast cancer cells is obviously higher than that in breast epithelial cells and other subtype cells, so that breast cancer samples can be screened more accurately. The molecular marker can be used to simply and quickly diagnose breast cancer, and becomes an effective tool for breast cancer detection and diagnosis, and has high application value for treating breast cancer diseases.

Description

Technical Field

[0001] This invention belongs to the field of biomedical technology, specifically relating to the application of lncRNA_AC005355.2 in the preparation of breast cancer diagnostic reagents. Background Technology

[0002] Breast cancer is one of the most common malignant tumors among women worldwide, ranking first in incidence and second in mortality globally. Therefore, there is an urgent need to study the important regulatory factors and networks in the pathogenesis of lumbar breast cancer, providing a scientific basis for the further development of novel biomarkers and targeted drugs. This is of great significance for early detection, early treatment, prognosis, and reducing the social burden of healthcare for patients.

[0003] Current technologies for diagnosing lumens breast cancer primarily rely on immunohistochemical-based clinicopathological typing of biopsy samples to confirm whether they are breast cancer samples and what molecular subtype they belong to. However, there are differences among molecular subtypes in terms of gene characteristics, age of onset, clinical features, malignancy, treatment sensitivity, and prognosis. Furthermore, the aforementioned molecular typing of breast cancer is based on mature gene levels, and it is expensive and involves complex testing procedures.

[0004] Long non-coding RNAs (lncRNAs) are a class of RNA molecules that do not have coding capabilities and whose transcript length exceeds 200 nt. lncRNAs can participate extensively in genome regulation and are important regulators of biological behaviors such as cell proliferation, differentiation, apoptosis, cell adhesion, and migration. Therefore, screening for lncRNAs that can be effectively used for the prevention and treatment of tumors is of great significance. Summary of the Invention

[0005] The purpose of this invention is to provide the application of lncRNA_AC005355.2 in the preparation of breast cancer diagnostic reagents. Using the lncRNA_AC005355.2, the expression level of lncRNA_AC005355.2 in breast cancer cells can be detected quickly and easily, thereby realizing the diagnosis of breast cancer and providing a new diagnostic biomarker for the early diagnosis and prognosis of breast cancer.

[0006] This invention provides the application of lncRNA_AC005355.2 and / or reagents for detecting lncRNA_AC005355.2 in the preparation of diagnostic reagents for breast cancer.

[0007] Preferably, the breast cancer includes Luminal breast cancer.

[0008] The present invention also provides a primer for amplifying lncRNA_AC005355.2, the primer comprising an upstream primer P1 and a downstream primer P2, the nucleotide sequences of the upstream primer P1 and the downstream primer P2 being shown in SEQ ID NO.1 and SEQ ID NO.2, respectively.

[0009] The present invention also provides a primer set for detecting lncRNA_AC005355.2, the primer set comprising the primers described in the above technical solution and primers for amplifying the internal reference gene GAPDH; the primers for amplifying the internal reference gene GAPDH comprise an upstream primer P3 and a downstream primer P4, the nucleotide sequences of the upstream primer P3 and the downstream primer P4 being shown in SEQ ID NO.3 and SEQ ID NO.4, respectively.

[0010] The present invention also provides a kit for diagnosing lumens breast cancer, the kit comprising the primer set, standards and PCR amplification reagents described in the above technical solution.

[0011] Preferably, the standard comprises cDNA containing lncRNA_AC005355.2 and the internal reference gene GAPDH.

[0012] Preferably, the cDNA of the internal reference gene GAPDH includes the cDNA of the MCF7 cell line.

[0013] Preferably, the PCR amplification reagent includes a real-time PCR amplification reagent.

[0014] Preferably, the kit also includes a reverse transcription reagent.

[0015] This invention also provides the application of the primers, primer sets, or kits described above in the preparation of breast cancer prognostic assessment reagents.

[0016] Beneficial effects:

[0017] This invention provides the application of lncRNA_AC005355.2 in the preparation of breast cancer diagnostic reagents. lncRNA_AC005355.2 serves as a novel molecular marker for detecting breast cancer, especially Luminal breast cancer. Its expression level in Luminal breast cancer cells is significantly higher than in breast epithelial cells and other subtypes, allowing for more accurate screening of breast cancer samples. This molecular marker enables simple and rapid diagnosis of breast cancer, becoming an effective tool for breast cancer detection and diagnosis, and has high application value for the treatment of breast cancer. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly described below.

[0019] Figure 1 The results of the detection of lncRNA_AC005355.2 in high-risk and low-risk breast cancer samples in Example 2 are shown.

[0020] Figure 2 The results of the detection of lncRNA_AC005355.2 in breast cancer tissue and adjacent normal tissue in Example 3;

[0021] Figure 3 The results of detecting lncRNA_AC005355.2 in different subtypes of breast cancer tissue samples in Example 3;

[0022] Figure 4 The results of the detection of lncRNA_AC005355.2 in estrogen receptor-positive and estrogen receptor-negative breast cancer tissues in Example 4;

[0023] Figure 5 The results of detecting lncRNA_AC005355.2 in different subtype breast cancer cell lines in Example 5;

[0024] Figure 6 This study analyzes the correlation between the expression of lncRNA AC005355.2 in Example 6 and the prognosis of breast cancer patients. Detailed Implementation

[0025] This invention provides the application of lncRNA_AC005355.2 in the preparation of diagnostic reagents for breast cancer.

[0026] The breast cancer described in this invention preferably includes Luminal breast cancer.

[0027] The lncRNA_AC005355.2 described in this invention has accession number ENSG00000251169 in the Ensembl database, preferably a partial sequence from ENSG00000251169, such as the nucleotide sequence shown in SEQ ID NO.5, specifically: 5'-TGGGGTCATTGGGCTGCCTTAGATTCCCCCCCCCA CCTCTCAGCCTGCTGCCTCTGGACAAAGCTCTGCAGAGGAGCCCCATCTCCTTCAGCCCCCTCCTGCCTTTGGGGTGCAAGTTTCCTGAAGGACTTGAGTGAGATGTCACCAAGCAACAGGCTGTCAGGCTCTTGGCAGCAAGTACTGGCCCAGCGACTCGCG GCAGAGTTCCTCCTTGGGGCGTCTGTCCTTATCAGGGGTGGATGCTGTCAGACTTGCTAATGGTGGAATTTCTGGCATGTGGCAGGGCCAAGTGCAGTGGCTCACACCTATAATCCCAGCACTTTGGGAGGCTGAGGCACGAGGATTGCTTGAGCCCAGGAGT TCATCACCAGCCTGGGCAATATAGCCAGACCCGGTCTCCACAAAAAAATTTTTAAAAATTAGCTGGGCATGGTGGCCTGTGCCTTGTAGTCCCAGCTCTTTGGGAGACTGAGGCAGGAGGATCAACTTGAGCCCAGAAGGTCGAAGCTGCAGTAAGCCATGGTC ATGCCAGCGGAGTTGAGCCTGGACCACAGAGCAAGACACTATAGGGAAGACAGCCAGGTGAAAATGAAGGCAGAGACCAGAGTTATGCATCCGAAAGGCAAGGAATGCCGGGGGCTGCCAGAAGCTGGAAGAGGCAAGGCAGGATCCCCCACTAAAGGCCTTGGAGGGAGCATGGCTTTAGCAGCACCTCAATTTGGGATGTCTATTTTCCGGAACAGCGGGAATAAGTGTCTGCTGCTGTAAGCCACCCTGCCTGTGGCACTTTGTTACAGCAGCCCAGGAACCTGACCCAGCCAGGCTGCTCCTGCTGCCCAGTGTGCCCTTCTCTCATCCCTCCAGCTGGTCTCTCACTGCCTTCGAGCCCCATCACCTGCT CGGGCTCCCTCTCTGTGTGTCCCCAGTTCTGGACACTTATTCAGCAGACCTGTAAGTTTTGCTGGCCAGCCTATCTCCCTGGCTAGACTGAAGGCTCCTTCAGGGCAGGCCTAACCTGTGCTAGGGCAGCATGATGCCTGGTACAGAATAGGGGCTCCTTAGATGTGGGGTAAATAAAGGAATGCTCGAAGGGTGATGGGCCCCTGTG-3'.

[0028] The expression level of lncRNA_AC005355.2 described in this invention is significantly higher in Luminal breast cancer cells than in breast epithelial cells and other subtypes of cells. It can be used as a diagnostic marker to more accurately screen and diagnose breast cancer samples, especially Luminal breast cancer samples.

[0029] The present invention also provides a primer for amplifying lncRNA_AC005355.2, the primer comprising an upstream primer P1 and a downstream primer P2, the nucleotide sequences of the upstream primer P1 and the downstream primer P2 being shown in SEQ ID NO.1 and SEQ ID NO.2, respectively.

[0030] The nucleotide sequence shown in SEQ ID NO.1 of this invention is specifically 5'-ATGGCTTTAGCAGCACCTCA-3', and the nucleotide sequence shown in SEQ ID NO.2 is specifically 5'-GGGCTGCTGTAACAAAGTGC-3'.

[0031] The present invention also provides a primer set for detecting lncRNA_AC005355.2, the primer set comprising the primers described in the above technical solution and primers for amplifying the internal reference gene GAPDH; the primers for amplifying the internal reference gene GAPDH comprise an upstream primer P3 and a downstream primer P4, the nucleotide sequences of the upstream primer P3 and the downstream primer P4 being shown in SEQ ID NO.3 and SEQ ID NO.4, respectively.

[0032] The internal reference gene GAPDH described in this invention has accession number ENSG00000111640 in the Ensembl database, and is preferably a partial sequence of ENSG00000111640, such as the nucleotide sequence shown in SEQ ID NO.6, specifically as follows:

[0033] 5'-GGAAATGAATGGGCAGCCGTTAGGAAAGCCTGCCGGTGACTAACC CTGCGCTCCTGCCTCGATGGGTGGAGTCGCGTGTGGCGGGGAAGTCAGGTGGAGCGAGGCTAGCTGGCCCGATTTCTCCTCCGGGTGATGCTTTTCCTAGATTATTCTCTGGTAAATCAAAGAAGTG GGTTTATGGAGGTCCTCTTGTGTCCCCTCCCCGCAGAGGTGTGGTGGCTGTGGCATGGTGCCAAGCCGGGAGAAGCTGAGTCATGGGTAGTTGGAAAAGGACATTTCCACCGCAAAATGGCCCCTCT GGTGGTGGCCCCTTCCTGCAGCGCCGGCTCACCTCACGGCCCCGCCCTTCCCCTGCCAGCCTAGCGTTGACCCGACCCCAAAGGCCAGGCTGTAAATGTCACCGGGAGGATTGGGTGTCTGGGCGCCTCGGGGAACCTGC CCTTCTCCCCATTCCGTCTTCCGGAAACCAGATCTCCCACCGCACCCTGGTCTGAGGTTAAATATAGCTGCTGACCTTTCTGTAGCTGGGGGCCTGGGCTGGGGCTTCTCCCCATCCCTTCTCCCCACACACATGCA-3'.

[0034] The nucleotide sequence shown in SEQ ID NO.3 of this invention is specifically 5'-GAACGGGAAGCTCACTGG-3', and the nucleotide sequence shown in SEQ ID NO.4 is specifically 5'-GCCTGCTTCACCACCTTCT-3'.

[0035] This invention also provides a kit for diagnosing lumbar breast cancer, the kit comprising the primer set, standards, and PCR amplification reagents described in the above-described technical solution. The standards of this invention preferably comprise cDNA containing lncRNA_AC005355.2 and the internal reference gene GAPDH, more preferably cDNA from the MCF7 cell line. The preferred content of the standards of this invention is 4 μL / kit; the preferred concentration is 2 μg / μL.

[0036] The PCR amplification reagents described in this invention preferably include real-time PCR amplification reagents. This invention does not specifically limit the source or composition of the PCR amplification reagents; any reagent capable of performing the PCR amplification can be used. For example, in the embodiments of this invention, the PCR amplification reagents include: SYBR Green 2×PCR mixed reaction buffer and ddH2O. The SYBR Green 2×PCR mixed reaction buffer was purchased from Tiangen (Beijing) Biotechnology Co., Ltd.; the amounts of each component should be determined according to the product instructions.

[0037] The kit described in this invention preferably also includes a reverse transcription reagent. This invention does not specifically limit the amount or source of the reverse transcription reagent; any reagent capable of performing reverse transcription is acceptable. For example, in one embodiment of this invention, the reverse transcription reagent in a kit includes: 4 μL of 5× reverse transcription buffer, 1 μL of 10 nM dNTPs, 1 μL of oligo primers, 1 μL of random primers, 1 μL of reverse transcriptase, and 12 μL of enzyme-free water; the reverse transcription reagent was purchased from Ribobio Biotechnology Co., Ltd.

[0038] In this invention, the method for diagnosing breast cancer using the above-mentioned kit includes the following steps:

[0039] The target lncRNA_AC005355.2 and the internal reference gene GAPDH were amplified in the cDNA of the test sample by real-time PCR, and the Ct values ​​of lncRNA_AC005355.2 and internal reference gene GAPDH in the test sample were obtained.

[0040] The expression level of lncRNA_AC005355.2 was corrected by adjusting the expression level of the internal reference gene GAPDH. Specifically: ΔCt(AC005355.2) = Ct(sample, AC005355.2) - Ct(standard, AC005355.2); ΔCt(GPADH) = Ct(sample, GAPDH) - Ct(standard, GAPDH). The ΔCt value of the experimental sample was normalized using the ΔCt value of the calibration sample, ΔCt = ΔCt(AC005355.2) - ΔCt(GAPDH), and 2... -ΔΔCtThe formula was used to calculate the relative PCR quantification value of lncRNA_AC005355.2;

[0041] The relative PCR quantification value of the lncRNA_AC005355.2 was compared with the relative PCR quantification value of the standard, where the relative PCR quantification value of the standard was 1.

[0042] When the relative PCR quantification value of lncRNA_AC005355.2 is greater than 1, it is considered high risk and diagnosed as a Luminal breast cancer sample; when the relative PCR quantification value of lncRNA_AC005355.2 is less than 1, it is considered low risk and diagnosed as a non-Luminal breast cancer sample.

[0043] The sample to be tested in this invention is preferably a breast cancer biopsy tissue sample, more preferably a lumens breast cancer biopsy tissue sample. The cDNA used in this invention is preferably obtained by reverse transcription of RNA, and the RNA is preferably extracted from the breast cancer biopsy tissue sample. This invention does not have a specific limitation on the method of RNA extraction; conventional extraction methods in the art are acceptable.

[0044] The preferred PCR amplification system of the present invention includes: 10 μL of SYBR GREEN 2×PCR mixed reaction buffer, 1 μL each of upstream and downstream primers, 7 μL of ddH2O, and 1 μL of cDNA template of the sample to be tested.

[0045] The preferred PCR amplification program of the present invention includes: pre-denaturation at 95°C for 5 minutes; denaturation at 95°C for 30 seconds, annealing at 60°C for 30 seconds, extension at 72°C for 30 seconds, for a total of 40 cycles.

[0046] This invention also provides the application of the primers, primer sets, or kits described above in the preparation of reagents for breast cancer prognostic assessment. The breast cancer described in this invention preferably includes Luminal breast cancer. The primers, primer sets, or kits described in this invention can achieve accurate prognostic assessment of breast cancer. The method for breast cancer prognostic assessment described in this invention is preferably the same as the method for breast cancer diagnosis described above, and will not be repeated here.

[0047] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0048] Example 1

[0049] A diagnostic kit for diagnosing lumbar breast cancer comprises the following components:

[0050] Primers for amplifying lncRNA_AC005355.2: upstream primer P1: 5'-ATGGCTTTAGCAGC ACCTCA-3' (SEQ ID NO.1), downstream primer P2: 5'-ATGGCTTTAGCAGCACCTC A-3' (SEQ ID NO.2); 1 μL each of upstream primer P1 and downstream primer P2;

[0051] Primers for detecting the internal reference gene GAPDH: upstream primer P3: 5'-GAACGGGAAGCTCACT GG-3' (SEQ ID NO. 3), downstream primer P4: 5'-GCCTGCTTCACCACCTTCT-3' (SEQ ID NO. 4); 1 μL each of upstream primer P3 and downstream primer P4;

[0052] PCR amplification reagents: 10 μL of SYBR GREEN 2×PCR mixed reaction buffer and 7 μL of ddH2O; each of the above PCR amplification reagents constitutes one part, comprising two parts;

[0053] Reverse transcription system: 4 μL 5× reverse transcription buffer, 1 μL 10 nM dNTPs, 1 μL oligo primers, 1 μL random primers, 1 μL reverse transcriptase, and 12 μL enzyme-free water.

[0054] Standard: MCF7 cell line cDNA, concentration 2 μg / μL, total 4 μL.

[0055] Example 2

[0056] The method for assessing breast cancer risk using the kit in Example 1 is as follows:

[0057] 1) First, extract total RNA from the tissue samples obtained by biopsy using the chloroform method, and perform quantitative analysis of RNA. Use 2 μg of total RNA as the starting amount for the next step. Perform reverse transcription reaction using the reverse transcription reagent in the kit in Example 1. The system is 20 μL, and the reaction conditions are as follows: 42℃, 60 minutes; 75℃, 5 minutes, to obtain cDNA.

[0058] 2) Take 1 μL of the cDNA obtained in step 1) as a template and perform qPCR amplification using the PCR amplification reagents provided in the kit in Example 1. Amplify lncRNA_AC005355.2 and the internal reference gene GAPDH separately. The primers used are as shown in the kit in Example 1. The PCR amplification system is: 10 μL of SYBR GREEN 2×PCR mixed reaction buffer, 1 μL of each primer, 7 μL of ddH2O, and 1 μL of reverse transcription product. The PCR amplification conditions are: 95℃ for 5 minutes for denaturing enzyme activation; 95℃ for 30 seconds for denaturation, 60℃ for 30 seconds for annealing, and 72℃ for 30 seconds for extension, for a total of 40 cycles.

[0059] 3) qPCR amplification of standards: Take 1 μL of the standard provided in the kit in Example 1 as a template, and amplify lncRNA AC005355.2 and the internal reference gene GAPDH separately. The primers used are as shown in the kit in Example 1. The PCR amplification system and amplification conditions are as in step 2.

[0060] 4) Result determination:

[0061] The Ct values ​​obtained from amplifying lncRNA_AC005355.2 and the internal reference gene GAPDH using cDNA as a template from the test sample were read separately. The results were then analyzed using 2... -ΔΔct The method corrects lncRNA_AC005355.2 using the internal reference gene GAPDH, specifically: ΔCt(AC005355.2) = Ct(sample, AC005355.2) - Ct(standard, AC005355.2); ΔCt(GPADH) = Ct(sample, GAPDH) - Ct(standard, GAPDH). The ΔCt value of the test sample is normalized using the ΔCt value of the calibration sample, ΔΔCt = ΔCt(AC005355.2) - ΔCt(GAPDH), to obtain the relative expression level of lncRNA_AC005355.2 in the test tissue, i.e., its relative quantitative value. The corrected data is compared with the relative expression level of the standard. The relative quantitative value of the standard is 1. When the relative quantitative value of the test tissue is greater than 1, it is considered high risk of Luminal breast cancer, and when it is less than 1, it is considered low risk of Luminal breast cancer.

[0062] Biopsy tissue samples from patients diagnosed with Luminal breast cancer (high-risk samples) and non-Luminal breast cancer samples (low-risk samples) were collected. The relative quantification of lncRNA_AC005355.2 was detected according to steps 1) to 4), and diagnostic prediction was performed. The results are as follows: Figure 1 As shown.

[0063] Depend on Figure 1It can be concluded that the relative quantification value of lncRNA_AC005355.2 in high-risk samples is 2.23, which is greater than 1; and the relative quantification value in low-risk samples is 0.33, which is less than 1, which is consistent with the actual situation.

[0064] Example 3

[0065] The method described in Example 2 was used to detect 48 pairs of breast cancer tissues and adjacent tissues from the Department of Breast Oncology. The 48 pairs of breast cancer tissues and adjacent tissues included 28 pairs of Luminal breast cancer tissues and adjacent tissues, 10 pairs of HER2 breast cancer tissues and adjacent tissues, and 7 pairs of Basal-like breast cancer tissues.

[0066] 1) The relative quantitative values ​​of lncRNA_AC005355.2 in breast cancer tissue and adjacent normal tissue were determined separately using 2 -ΔΔct The relative quantitative values ​​were calculated, and the results are as follows: Figure 2 As shown;

[0067] Depend on Figure 2 It can be seen that the expression of lncRNA_AC005355.2 in cancerous tissue is significantly higher than that in adjacent normal tissue.

[0068] 2) The relative quantitative values ​​of lncRNA_AC005355.2 in the above three types of breast cancer tissues were compared, and the results are as follows: Figure 3 As shown;

[0069] Depend on Figure 3 It can be concluded that the expression of lncRNA_AC005355.2 in Luminal breast cancer tissues is significantly higher than that in other subtypes.

[0070] Example 4

[0071] Using the GEPIA database, breast cancer sequencing data from the TCGA database were retrieved, and the expression level of lncRNA AC005355.2 was downloaded. Based on clinical information, the breast cancer groups were divided into estrogen receptor-positive and estrogen receptor-negative groups. Independent t-tests were used to compare the expression differences between the two groups. It was found that the expression level of lncRNA AC005355.2 in estrogen receptor-positive breast cancer tissue was significantly higher than that in estrogen receptor-negative breast cancer tissue. Figure 4 As shown, this further illustrates the high specificity of lncRNA AC005355.2 in the expression of Luminal breast cancer.

[0072] Example 5

[0073] The relative quantification of lncRNA_AC005355.2 in different subtypes of breast cell lines was determined using the methods in steps 1)-3) of Example 2, with the MCF-10A breast cell line as the normal control. The breast cancer cell lines included:

[0074] 1) Luminal breast cancer cell lines: MCF-7 cell line, T47D cell line, and ZR-75 cell line;

[0075] 2) HER2-type breast cancer cell lines: SKBR3 cell line and HCC1954 cell line;

[0076] 3) Basal-type breast cancer cell lines: MAD-MB-231 cell line and MDA-MB-468 cell line;

[0077] Two biological replicates were set up for each cell line, and the average value was used for analysis. The results are as follows: Figure 5 As shown:

[0078] Depend on Figure 5 The relative expression levels of lncRNA AC005355.2 in the MCF-10A, MCF-7, T47D, ZR-75, SKBR3, HCC1954, MAD-MB-231, and MDA-MB-468 breast cell lines were 1, 3.89579, 3.35574, 2.44151, 0.994412, 0.5369, 0.2259, and 0.0123, respectively. Therefore, it can be concluded that the relative expression level of lncRNA AC005355.2 in lumbar breast cancer cell lines was significantly higher than that in other subtypes and normal breast cells.

[0079] Example 6

[0080] The method described in Example 2 was used to analyze the correlation between the expression of lncRNA AC005355.2 in Luminal breast cancer patients and their prognosis.

[0081] Specifically, the relative expression level of lncRNA AC005355.2 was determined in 82 patients with lumens breast cancer from the Department of Breast Oncology. The relative expression level of lncRNA AC005355.2 was compared with the standard according to the determination method in Example 2. When the relative expression level of lncRNA AC005355.2 was greater than 1, it was considered as high expression, and when it was less than 1, it was considered as low expression.

[0082] Kaplan-Meier survival analysis was used to statistically analyze the relationship between lncAC005355.2 expression and prognosis. The results are as follows: Figure 6As shown. By Figure 6 It can be concluded that patients with Luminal breast cancer who highly express lncRNA AC005355.2 have a poorer prognosis.

[0083] From the above examples, it can be concluded that lncRNA AC005355.2 and the reagent for detecting lncRNA AC005355.2 can be used as diagnostic markers for luminal breast cancer.

[0084] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. Application of the reagent for detecting lncRNA_AC005355.2 in the preparation of a diagnostic kit for luminal breast cancer, wherein the nucleotide sequence of lncRNA_AC005355.2 is shown in SEQ ID NO.

5.

2. Application of the reagent for detecting lncRNA_AC005355.2 in the preparation of a kit for prognostic assessment of luminal breast cancer, wherein the nucleotide sequence of lncRNA_AC005355.2 is shown in SEQ ID NO.

5.

3. The application according to claim 1 or 2, characterized in that, The reagent for detecting lncRNA_AC005355.2 includes primers for amplifying lncRNA_AC005355.2, wherein the primers include an upstream primer P1 and a downstream primer P2, and the nucleotide sequences of the upstream primer P1 and the downstream primer P2 are shown in SEQ ID NO.1 and SEQ ID NO.2, respectively.

4. The application according to claim 1 or 2, characterized in that, The reagent for detecting lncRNA_AC005355.2 includes a primer set for detecting lncRNA_AC005355.2, wherein the primer set includes the primers described in claim 3 and primers for amplifying the internal reference gene GAPDH; The primers for amplifying the internal reference gene GAPDH include upstream primer P3 and downstream primer P4, and the nucleotide sequences of upstream primer P3 and downstream primer P4 are shown in SEQ ID NO.3 and SEQ ID NO.4, respectively.

5. The application according to claim 1 or 2, characterized in that, The kit includes standards, PCR amplification reagents, and the primer set as described in claim 4.

6. The application according to claim 5, characterized in that, The standard includes cDNA containing lncRNA_AC005355.2 and the internal reference gene GAPDH.

7. The application according to claim 5, characterized in that, The cDNA of the internal reference gene GAPDH includes the cDNA of the MCF7 cell line.

8. The application according to claim 5, characterized in that, The PCR amplification reagents include real-time PCR amplification reagents.

9. The application according to claim 5, characterized in that, The kit also includes a reverse transcription reagent.

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