RNA for treating triple negative breast cancer and application thereof

Abstract

The invention relates to RNA370 and application of the RNA370 in preparation of a medicine for improving sensitivity of triple negative breast cancer to paclitaxel. The RNA370 can be competitively combined with TUBB4A mR NA binding protein PCBP2 with TUBB4A mRNA, the interaction between the TUBB4A mRNA and the PCBP2 is blocked, more TUBB4A mRNA is released into cytoplasm, the content of TUBB4A protein is promoted to be increased, and then responsiveness of the triple negative breast cancer to paclitaxel treatment is enhanced. The RNA370 provided by the invention can be combined with the chemotherapeutic drug paclitaxel for use, so that the sensitivity of the triple negative breast cancer to the paclitaxel is enhanced, the drug resistance of the paclitaxel is overcome, a better treatment effect is achieved, a new thought and breakthrough are provided for reversing the drug resistance of the paclitaxel, and the RNA370 has a wide application prospect and market potential.

Description

Technical Field

[0001] The present invention belongs to the field of biomedicine technology, and specifically relates to an RNA for treating triple-negative breast cancer and an application thereof, and more specifically relates to the use of RNA370 in preparing a drug for improving the sensitivity of triple-negative breast cancer cells to paclitaxel. Background Art

[0002] The latest global cancer burden data for 2020 released by the World Health Organization's International Agency for Research on Cancer (IARC) shows that in 2020, the number of new cases of breast cancer worldwide reached 2.26 million, making it the world's number one cancer. In China, breast cancer is the most common cancer in women, accounting for 19.2% of all cancers in women and the leading cause of cancer deaths in women, of which triple negative breast cancer (TNBC) accounts for about 15%. Triple negative breast cancer is a type of breast cancer that does not express estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER-2), so HER-2 targeted therapy cannot be used. Compared with other subtypes of breast cancer, TNBC is highly invasive and more prone to recurrence and metastasis. The 5-year breast cancer-specific survival rate of stage I patients is 85%, and the prognosis is worse.

[0003] At present, the treatments for triple-negative breast cancer mainly include surgical resection, radiotherapy, chemotherapy and immunotherapy, among which chemotherapy is an effective treatment for TNBC, and chemotherapy based on anthracycline taxanes is the standard treatment for TNBC. However, the problem of chemotherapy resistance is becoming increasingly serious, and there is an urgent need to find more effective treatment strategies. In recent years, targeted therapy, an important research direction for the treatment of triple-negative breast cancer, has been acting on molecules or signaling pathways specific to breast cancer cells, which can not only reduce the side effects and toxicity of traditional treatments, but also improve the accuracy and effectiveness of treatment, thereby improving the survival rate and quality of life of patients.

[0004] At present, paclitaxel is one of the important drugs for the treatment of breast cancer, but many patients develop resistance to paclitaxel, which affects the treatment effect. Although some drugs can enhance the efficacy of paclitaxel, such as chemotherapy drugs such as cisplatin and carboplatin, their combination with paclitaxel can increase the sensitivity of breast cancer cells to paclitaxel, but the effect is limited. TUBB4A (Tubulin Beta4A Class IVa), β-IVa type tubulin, is a member of the tubulin family and plays a key role in the formation of microtubules. Microtubules are an important component of the cytoskeleton and are involved in many cellular processes, including cell division, cell migration, and intracellular transport. Studies have shown that reduced expression of β-Ⅳ type tubulin in breast cancer can lead to resistance of cancer cells to paclitaxel.

[0005] In recent years, the research and development of small nucleic acid drugs and clinical treatment have achieved many breakthroughs. According to the different structures, drug mechanisms and targets of small nucleic acids, various types have been developed, including antisense oligonucleotides (ASO), small interfering RNA (siRNA), aptamer RNA, microRNA (miRNA), small activating RNA (saRNA) and CpG oligonucleotides (CpGoligonucleotide), ribozyme, transfer RNA (tRNA), antibody nucleic acid conjugate drug (ARC), etc. Among them, microRNA (miRNA) as a single-stranded short non-coding RNA can participate in the negative regulation of cell transcription. The miRNA in tumor cells can target and bind to mRNA, inhibit the normal expression and translation of mRNA. In addition, changes in intracellular molecular signaling pathways can also affect the normal function of cells, thereby promoting tumor progression. MiR-100 can inhibit transcription factors induced by epithelial-mesenchymal transition (EMT) and directly regulate the expression of genes related to tumorigenesis. MiR-128 can target the Bcl-2-associated X (BAX) gene to promote the proliferation of MCF-7 cells. miR-24, miR-26a, and miR-27a in breast cancer cells can activate the MAPK pathway, leading to breast cancer metastasis. MiR-210 can inhibit adrenaline-A3 and protein tyrosine phosphatase 1B, promoting breast cancer angiogenesis. The expression levels of miR-17, miR-30a, miR-100, and miR-222 in MCF-7 cell exosomes after paclitaxel treatment increased, thereby mediating cell resistance. In addition to the most widely known function of miRNA: targeting the mRNA level of negatively regulated genes and mediating their degradation, miRNA also has a variety of non-classical molecular mechanisms, such as the precursor pri-miRNA of miRNA can be translated into polypeptides (has-pri-miR-22), miRNA can also bind to other functional proteins (has-miR-146a-5p and Gag), and miRNA can also competitively hinder its binding to mRNA by binding to RNA-binding proteins, thereby promoting the expression of mRNA (miR-328 and hnRNP E2 / CEBPA). However, there is currently a lack of reports on small nucleic acid molecule drugs that enhance the efficacy of paclitaxel in the treatment of triple-negative breast cancer. Summary of the invention

[0006] The purpose of the present invention is to solve the problems of how to improve the sensitivity of triple-negative breast cancer to paclitaxel or increase the sensitivity of triple-negative breast cancer to paclitaxel and reverse the paclitaxel chemotherapy resistance.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] The present invention provides an RNA for treating triple-negative breast cancer. The RNA is single-stranded, and its nucleotide sequence comprises SEQ ID NO: 1.

[0009] The present invention also provides an RNA for treating triple-negative breast cancer, wherein the RNA is RNA370, and the nucleotide sequence of the RNA370 is shown in SEQ ID NO.1.

[0010] The present invention also provides RNA mimics of the RNA.

[0011] The present invention also provides an expression vector for expressing the RNA, preferably, the expression vector is GV219.

[0012] The present invention also provides a cell containing the RNA or the expression vector.

[0013] The present invention also provides a preparation for treating triple-negative breast cancer, wherein the preparation comprises the RNA or the RNA mimics or the expression vector or the cell; preferably, the preparation also comprises a chemotherapeutic drug for triple-negative breast cancer; preferably, the chemotherapeutic drug for triple-negative breast cancer is paclitaxel.

[0014] The present invention also provides a use of the RNA or the RNA mimics (mimics) or the expression vector or the cell in preparing a drug for treating triple-negative breast cancer.

[0015] The present invention also provides a use of the RNA or the RNA mimics (mimics) or the expression vector or the cell in preparing a drug for improving the sensitivity of triple-negative breast cancer cells to paclitaxel.

[0016] The present invention also provides the use of the preparation in preparing a drug for treating triple-negative breast cancer or improving the sensitivity of triple-negative breast cancer cells to paclitaxel.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects: the present invention first discovered that RNA370 can highly specifically identify and target RNA binding protein PCBP2, and by competing with TUBB4A mRNA for TUBB4A mRNA binding protein PCBP2, block the interaction between TUBB4A mRNA and PCBP2, release more TUBB4A mRNA into the cytoplasm, increase the content of TUBB4A protein, and thus enhance the responsiveness of triple-negative breast cancer to paclitaxel treatment. The RNA370 of the present invention can be used in combination with the chemotherapy drug paclitaxel to enhance the sensitivity of triple-negative breast cancer to paclitaxel, overcome paclitaxel resistance, and achieve better therapeutic effects, providing a new idea and breakthrough for reversing paclitaxel resistance, and has broad application prospects and market potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the result of immunoblotting analysis 48 hours after RNA370 transfection, in which GAPDH is the internal reference; RNA370 represents RNA370 mimics.

[0019] Figure 2 This is the result of the nuclear and cytoplasmic mRNA isolation and RT-PCR experiment 48 hours after RNA370 transfection, where Actin was used as the cytoplasmic internal reference RNA and U6 as the nuclear internal reference RNA.

[0020] Figure 3 After transfection with RNA370 or NC, the cells were plated on slides 24 hours later, and RNA-FISH experiments were performed 48 hours later.

[0021] Figure 4 Schematic diagram of RNA370 competing with TUBB4A mRNA for binding protein PCBP2, blocking the interaction between TUBB4A mRNA and PCBP2, and releasing more TUBB4A mRNA into the cytoplasm.

[0022] Figure 5 The EdU experiment was used to detect the proliferation of TNBC cells under the treatment of RNA370 and paclitaxel alone or in combination.

[0023] Figure 6 This is a quantitative graph of the results of EdU experiment to detect the efficacy of RNA370 in sensitizing triple-negative breast cancer cells to paclitaxel.

[0024] Figure 7A is the result of immunoblot analysis of the control group, RNA370 group, RNA370+siTUBB4A co-transfection group and siTUBB4A treatment group; B is the EdU experiment to detect the proliferation of RNA370 group, RNA370+siTUBB4A co-transfection group and siTUBB4A treatment group under paclitaxel (1 μg / ml) treatment and the quantitative graph, the data are expressed as Mean±SD, *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001.

[0025] Figure 8 A is a CCK-8 assay to detect the cell activity of the drug-resistant cell line MDA-MB-231 / PR and its parental cell line after 48 hours of treatment with different paclitaxel concentrations (1ng / ml, 10ng / ml, 100ng / ml, 1000ng / ml, 10000ng / ml); B is an immunoblot analysis of MDA-MB-231, MDA-MB-231 / PR, and MDA-MB-231 / PR cell lines treated with RNA370; C is an EdU assay to detect the cell proliferation of the MDA-MB-231 parental cell line and the MDA-MB-231 / PR drug-resistant cell line under different conditions (untreated, paclitaxel-treated, paclitaxel plus RNA370-treated) and a quantitative analysis chart. Data are expressed as Mean±SD. **P<0.01, ****P<0.0001.

[0026] Fig. 9 A is a comparison of the tumor size in the control group and the treatment group 18 days after drug injection; B is the dynamic volume of the transplanted tumor after injection of paclitaxel or an equal volume of saline at different times (mean±SD, n=5), **, P<0.01, n=5. DETAILED DESCRIPTION

[0027] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0028] Unless otherwise specified, the experimental methods involved in the examples are all conventional methods.

[0029] Example 1 Design and Synthesis of RNA370

[0030] Based on the previous report that PCBP2 binds to TUBB4A mRNA, a small molecule nucleic acid RNA370 was designed, and its nucleotide sequence is shown in SEQ ID NO: 1: UCACCCCUACCCUCCCUCCCCGCUUCCCUG. Shanghai Genetech was commissioned to chemically synthesize RNA370 mimics (RNA370 referred to as RNA370 mimics) and control NC-mimics (hereinafter referred to as NC).

[0031] Example 2 Effect of RNA370 in triple-negative breast cancer cells

[0032] 1. Breast cancer cells MDA-MB-231 or BT549 were cultured in RPMI1640 medium containing 10% fetal bovine serum (FBS), and a mixture of penicillin and streptomycin (100X) was added to the medium. All cells were placed in a 37°C incubator containing 5% CO2 and passaged every 2-3 days.

[0033] 2. Cell transfection was inoculated in 6-well plates with a cell density of 4×10 5 / well, 2 mL per well, cultured overnight at 37°C. The specific steps of transfection are as follows: dilute 5 μL 20 μM RNA370 or NC in 125 μL DEME serum-free medium, and dilute 5 μL Lipofectamine 3000 (Invitrogen) in 125 μL DEME serum-free medium. Incubate the two solutions at room temperature for 5 minutes and then mix. After the mixed solution is allowed to stand at room temperature for 15 minutes, add 260 μL of the mixed solution to a 6-well plate inoculated with MDA-MB-231 or BT549 cells. The final concentration of RNA370 or NC is about 20 μM. The cells are cultured in a 37°C cell culture incubator for 8 hours, and then replaced with 2 mL of RPMI1640 complete medium containing 10% fetal bovine serum and a mixture of penicillin and streptomycin (100X), and then cultured at 37°C for another 24 hours.

[0034] 3. Western Blot Experiment

[0035] (1) Prepare protein samples: First, remove the culture medium of MDA-MB-231 or BT549 cells transfected with RNA370 or NC and their parental cells, and gently wash the cells three times with cold PBS, shaking for 1 minute each time and then pouring off the wash solution to remove the culture medium. Then, place the culture flask on ice for later use. Prepare lysis buffer: Add 1 μL of PMSF (concentration of 100 mM) to every 100 μL RIPA lysis buffer. Add 120 μL of lysis buffer containing PMSF to each cell sample, gently shake to evenly cover the liquid, and then lyse on ice for 30 minutes. Collect the cells using a cell scraper and transfer them to a 1.5 ml EP tube, centrifuge at 13,000 rpm at 4°C for 30 minutes. Collect the supernatant into a new EP tube, use a small amount of sample to determine the protein concentration, add 4XSDS-loading buffer to the remaining sample, boil at 100°C for 8 minutes, and then aliquot and store at -80°C.

[0036] (2) Protein concentration determination: Prepare BCA working solution according to the sample volume, with a ratio of BCA reagent A and B of 50:1. Dilute the protein standard to 0.5 mg / ml, add different volumes to a 96-well plate, and make up to 20 μL with PBS. Add 2 μL of sample to the sample well, also make up to 20 μL with PBS, add 200 μL of BCA working solution, incubate at 37°C for 30 minutes, and use a microplate reader at a wavelength of 590 nm to measure and calculate the protein concentration.

[0037] (3) Protein immunoblotting: Prepare separation gel and stacking gel, then load 30 μg protein per lane and pre-stain 3 μL of marker. Start electrophoresis at 80 V, and adjust the voltage to 100 V when the marker separates until bromophenol blue runs to the end of the gel. Prepare the transfer buffer in advance. The PVDF membrane needs to be pretreated with methanol for 15 seconds to activate its surface. The transfer "sandwich" structure is: black sponge facing down, a layer of filter paper, a wet PVDF membrane, gel, another layer of filter paper, and red sponge facing up. Be sure to remove any bubbles during the process. Set the voltage to 100 V and continue the transfer for 2 hours at 4°C. Use 5% BSA solution to block the membrane for 1 hour. Incubate overnight with TUBB4A and GAPDH antibodies (both diluted to 1:1000) at 4°C using antibody diluent. Afterwards, wash three times with TBST buffer for 10 minutes each. Incubate with secondary antibody for 1.5 hours at room temperature, and then wash three times with TBST. The PVDF membrane was dried, and then an equal volume of ECL reagent A and B were mixed and the membrane was completely infiltrated for 1 minute. The protein detection and analysis were completed under appropriate conditions. The expression level of TUBB4A protein in MDA-MB-231 or BT549 cells treated with RNA370 was detected by protein immunoblotting. The results are shown in Figure 1The results showed that the expression of TUBB4A protein in the RNA370-treated group was significantly increased compared with that in the NC group.

[0038] 4. Isolation and extraction of RNA from nuclei and cytoplasm

[0039] The cytoplasmic and nuclear mRNAs were isolated by the Thermo Fisher AM1921 kit, and then the expression of TUBB4A mRNA in the cytoplasm and nucleus of MDA-MB-231 or BT549 cell lines transfected with RNA370 and NC and the parental cell line was analyzed by qPCR. Figure 2 The results showed that after transfection with RNA370, the expression of TUBB4A mRNA in the nucleus decreased, while the expression in the cytoplasm increased. Compared with NC, the expression of TUBB4A mRNA in the cytoplasm increased after RNA370 treatment of MDA-MB-231 and BT549.

[0040] 5. RNA fluorescence in situ hybridization (RNA-FISH)

[0041] About 2000 cells (NC-transfected cells and RNA370-transfected cells) were planted in the selected area on each slide. After 24 hours, the cells were washed with PBS 3 times for 5 minutes each time; fixed with 4% paraformaldehyde at 37°C for 10 minutes. The cells were washed with PBS 3 times for 5 minutes each time; permeabilized with 0.5% TritonX-100 PBS solution for 10 minutes. The cells were washed with PBS 3 times for 5 minutes each time; blocked with 10% goat serum for 1 hour. The cells were washed with PBS 3 times for 5 minutes each time; and then dehydrated with 75%, 95%, and 100% ice ethanol series in sequence. The FITC-TUBB4A (purchased from Shanghai Bioengineering Co., Ltd., the FITC-TUBB4A probe sequence is 5'-GCUUGAGGGUGCGGAAACAGAUGUCGUAGAGUGC-3' (SEQ ID NO: 2) (1:200 dilution) probe was placed in a constant temperature water bath at 85°C for 5 min, and then immediately placed at 0°C for 10 min to denature the RNA probe. Then the denatured probe was dropped onto the glass slide and covered with a cover slip and sealed with nail polish, and then placed in a humid dark box at 42°C for 12h to 16h. The cover slip was carefully removed with tweezers, and the hybridized glass slide specimen was placed in 2×SSC at 42°C for 3 times, 5 min each time, and 1×SSC at 42°C for 3 times, 5 min each time, and 2×SSC at room temperature for 1 time. Then it was dehydrated in a series of 75%, 95%, and 100% ice ethanol. 10μL was added dropwise DAPI, cover with a coverslip and incubate at room temperature for 5 min. The localization of TUBB4A mRNA in cells was observed under a fluorescence microscope. Figure 3As shown: In cells transfected with NC, TUBB4A mRNA is distributed in both the nucleus and cytoplasm; after transfection with RNA370, TUBB4A mRNA is more distributed in the cytoplasm. Compared with NC, after RNA370 treatment of MDA-MB-231 and BT549, the nuclear-cytoplasmic ratio decreased, that is, the distribution of TUBB4A mRNA in the cytoplasm increased. Figure 2 and Figure 3 The verification results show that Figure 4 The results show that RNA370 can competitively bind to the TUB B4A mRNA binding protein PCBP2, blocking the interaction between TUBB4A mRNA and PCBP2, releasing more TUBB4A mRNA into the cytoplasm, and increasing the content of TUBB4A protein.

[0042] 6. EdU experiment

[0043] EdU (5-ethynyl-2'-deoxyuridine) is a new type of thymidine analog that can replace thymidine during DNA synthesis and be embedded in the newly synthesized DNA chain. At the same time, the ethynyl group on the EdU molecule can undergo a click reaction with a fluorescently labeled small molecule azide probe. Through the click reaction, the newly synthesized DNA will be labeled with the corresponding fluorescent probe, so that the proliferating cells can be detected using appropriate fluorescence detection equipment. TM EdU-488 cell proliferation detection kit was used to detect the proliferation of MDA-MB-231 or BT549 cells when paclitaxel (1 μg / ml or 2 μg / ml) and RNA370 (20 μM) were used alone or in combination. Figure 5 and Figure 6 As shown, after BT549 and MDA-MB-231 received RNA370 (concentration 20μM) + paclitaxel (concentration 1μg / ml or 2μg / ml), the proportion of Edu-positive cells and the proliferation activity were lower than those of the paclitaxel group alone; thus, when RNA370 and paclitaxel were used in combination, the number of EdU-positive cells decreased, that is, RNA370 further inhibited the proliferation of TNBC cells and increased the sensitivity of TNBC cells to paclitaxel.

[0044] 7. Targeting verification of RNA370

[0045] To further verify the specific targeting effect of RNA370, we performed immunoblot analysis to compare the TUBB4A protein expression levels in the control group (NC), the RNA370 treatment group alone, the RNA370 and siTUBB4A (siTUBB4A-sense: 5'-GCACUCUACGACAUCUGUUTT-3' (SEQ ID NO: 3), siTUBB4A-antisense: 5'-AACAGAUGUCGUAGAGUGCTT-3' (SEQ ID NO: 4)) co-transfection group, and the siTUBB4A group alone in MDA-MB-231 or BT549 cells. The results are shown in Figure 7 The results showed that the expression of TUBB4A protein in the RNA370 group was significantly higher than that in the control group; in the siTUBB4A treatment group, the expression of TUBB4A protein was significantly reduced, showing the specific knockdown effect of siRNA. It is worth noting that the expression level of TUBB4A protein in the RNA370 and siTUBB4A co-transfection group was significantly decreased ( Figure 7 A), indicating that the effect of RNA370 was partially neutralized by the knockdown effect of siTUBB4A, indicating that RNA370 specifically increases the stability and expression of TUBB4A mRNA. In addition, through EdU experiments, we further confirmed that RNA370 enhanced the sensitivity of TNBC cells to paclitaxel, but this sensitization effect was partially offset after co-transfection with siTUBB4A ( Figure 7 B). It was further verified that RNA370 enhances the sensitivity of TNBC cells to paclitaxel by specifically regulating the expression of TUBB4A. In summary, these experimental results jointly prove that RNA370 effectively enhances the sensitivity of TNBC cells to paclitaxel by specifically regulating the expression of TUBB4A, verifying the targeting of RNA370.

[0046] 8. Construction and verification of paclitaxel-resistant breast cancer cell line

[0047] In this example, the MDA-MB-231 cells were induced by gradually increasing the concentration of paclitaxel from an initial concentration of 1 ng / ml to 10 ng / ml, and the paclitaxel-resistant cell line MDA-MB-231 / PR was finally obtained. The sensitivity to paclitaxel was detected by CCK-8 method, and the TUBB4A protein levels in MDA-MB-231, MDA-MB-231 / PR, and MDA-MB-231 / PR cell lines treated with RNA370 for 48 hours (MDA-MB-231 / PR+RNA370) were detected by IB, and the proliferation ability of the resistant cell lines was evaluated by EdU cell proliferation assay. The experimental results are shown in Figure 2. Figure 8The IC50 value of MDA-MB-231 / PR cell line (4235ng / ml) was significantly higher than that of the parental cell line (437.5ng / ml), confirming its significant resistance to paclitaxel ( Figure 8 A). In the MDA-MB-231 / PR resistant cell line, PCBP2 expression was increased and TUBB4A protein level was decreased compared with the parental cell line. However, when the resistant cell line was transfected with RNA370, TUBB4A protein level was partially restored ( Figure 8 B). After paclitaxel treatment, the proliferation ability of MDA-MB-231 / PR cell line decreased, but still maintained at a high level. After RNA370 transfection, the proliferation ability of drug-resistant cell lines was further reduced ( Figure 8 C), indicating that RNA370 can help reverse paclitaxel resistance.

[0048] Example 3 Verification of the in vivo effect of RNA370

[0049] First, a recombinant plasmid (named 370) overexpressing RNA370 was constructed using the GV219 expression vector. The plasmid was then transfected into MDA-MB-231 cells to obtain 2-370 cells overexpressing RNA370. Four-week-old BALB / cNude nude mice were purchased and raised at the Animal Center of Shantou University Medical College. When the nude mice reached 6 weeks of age, they were randomly divided into 2 groups, 10 in each group. Each nude mouse was subcutaneously injected with 100 μL of approximately 5×10 6 One group of nude mice was inoculated with MDA-MB-231 cells that were growing well, and another group was inoculated with 2-370 cells. Cell injection was diluted with saline, 200 μL per nude mouse.

[0050] When the tumor volume reaches 150-200mm 3 At the same time, the nude mice in each group were divided into groups again, and the nude mice were evenly distributed according to the size of the tumor, with 5 mice in each group. The specific grouping is as follows:

[0051] Group 1: xenograft tumors injected with MDA-MB-231 cells were treated with normal saline (i.e., 231+NS group);

[0052] Group 2: xenograft tumors injected with MDA-MB-231 cells were treated with 10 mg / kg paclitaxel (i.e., 231+paclitaxel group);

[0053] Group 3: xenograft tumors injected with 2-370 cells were treated with saline (i.e., 2-370+NS group);

[0054] The fourth group consisted of xenograft tumors injected with 2-370 cells and treated with 10 mg / kg paclitaxel (ie, the 2-370+paclitaxel group).

[0055] Paclitaxel was dissolved in corn oil to prepare a 10 mg / kg paclitaxel solution. Then two groups of nude mice were gavaged with normal saline or intraperitoneally injected with 10 mg / kg paclitaxel solution. The drug was administered once every 2 days and the length and width of the tumor were observed and recorded. The length and width of the tumor were calculated by (length × width). 2 ) / 2 to calculate the tumor volume and draw the tumor growth curve; when the volume of the xenograft tumor in the control group reached 2000mm 3 When , the experiment was terminated.

[0056] The experimental results are as follows Fig. 9 As shown, by overexpressing RNA370 and combining it with paclitaxel, it was observed that the tumor growth in nude mice was significantly inhibited. This indicates that RNA370 increases the sensitivity of triple-negative breast cancer cells to paclitaxel.

[0057] The present invention illustrates the technical solution of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned steps, that is, it does not mean that the present invention must rely on the above-mentioned steps to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An RNA for treating triple-negative breast cancer, characterized in that: The RNA is single-stranded, and its nucleotide sequence comprises SEQ ID NO:

1.

2. The RNA according to claim 1, characterized in that The RNA is RNA370, and the nucleotide sequence of the RNA370 is shown in SEQ ID NO.

1.

3. An RNA mimic of the RNA of claim 1 or 2.

4. An expression vector for expressing the RNA according to claim 1 or 2, characterized in that: The expression vector is GV219.

5. A cell containing the RNA according to claim 1 or the expression vector according to claim 4.

6. A preparation for treating triple-negative breast cancer, characterized in that: Containing the RNA of claim 1 Or the RNA mimics of claim 3, or the expression vector of claim 4, or the cell of claim 5, and the preparation further comprises a chemotherapeutic drug for triple-negative breast cancer.

7. The preparation according to claim 6, characterized in that The chemotherapy drug for triple-negative breast cancer is paclitaxel.

8. Use of the RNA according to claim 1, the RNA mimic according to claim 3, the expression vector according to claim 4, or the cell according to claim 5 in the preparation of a drug for treating triple-negative breast cancer.

9. Use of the RNA according to claim 1, the RNA mimic according to claim 3, the expression vector according to claim 4, or the cell according to claim 5 in the preparation of a drug for improving the sensitivity of triple-negative breast cancer cells to paclitaxel.

10. Use of the preparation according to any one of claims 6 to 7 in the preparation of a drug for treating triple-negative breast cancer or increasing the sensitivity of triple-negative breast cancer cells to paclitaxel.

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