Application of DKC1 inhibitors in the preparation of drugs for treating multiple myeloma

Abstract

The present invention provides an application of a DKC1 inhibitor in the preparation of a drug for treating multiple myeloma, and belongs to the field of biomedical technology. The present invention finds that DKC1 can be used as a new target for treating multiple myeloma, and by inhibiting the expression of DKC1, the proliferation of myeloma cells can be inhibited and the apoptosis of myeloma cells can be promoted, thereby slowing down the growth of the tumor and achieving the effect of effectively treating multiple myeloma. The present invention provides a new idea for the treatment of multiple myeloma and has broad application prospects.

Description

Technical Field

[0001] The present invention relates to the field of biomedicine technology, and in particular to application of a DKC1 inhibitor in preparing a drug for treating multiple myeloma. Background Art

[0002] Multiple myeloma is a fatal malignant plasma cell disease. The malignant clonal proliferation of plasma cells in the patient's bone marrow and the secretion of monoclonal immunoglobulins will lead to damage to related organs and tissues, causing consequences such as osteolytic destruction, anemia, renal damage and hypercalcemia. The application of traditional drugs and new drugs in recent years, such as proteasome inhibitors, immunomodulators, monoclonal antibodies, bispecific antibodies, antibody-drug conjugates (ADCs) and CAR-T, has provided more possibilities for the treatment of multiple myeloma. However, although new anti-myeloma drugs have improved the remission rate and survival time of patients, almost all patients will eventually relapse due to tiny residual disease and have a poor prognosis. Therefore, finding new therapeutic targets for multiple myeloma is the focus of current research.

[0003] The DKC1 gene is located on the X chromosome and encodes an evolutionarily conserved dyskeratin protein, which plays an active role in maintaining the stability of telomerase. In addition, the DKC1 gene is also involved in cell mitosis and metabolic processes, and can mediate post-transcriptional modification of ribosomal RNA (rRNA) as a pseudouridine synthase. At present, studies have shown that the DKC1 gene plays a carcinogenic role in tumors such as colon cancer. In order to further develop its application in multiple myeloma, the present invention intends to explore the application potential of the DKC1 gene as a new target for the treatment of multiple myeloma. Summary of the invention

[0004] The present invention finds that DKC1 can be used as a new target for treating multiple myeloma. By inhibiting the expression of DKC1, the proliferation of myeloma cells can be inhibited and the apoptosis of myeloma cells can be promoted, thereby slowing down the growth of the tumor and achieving the effect of effectively treating multiple myeloma.

[0005] The technical solution of the present invention is as follows:

[0006] Application of DKC1 inhibitor in the preparation of drugs for treating multiple myeloma.

[0007] The accession number of the DKC1 mRNA sequence in GenBank is NM_001363.5.

[0008] Preferably, the DKC1 inhibitor can inhibit the expression of DKC1.

[0009] Preferably, the DKC1 inhibitor is pyrazoline.

[0010] Preferably, the DKC1 inhibitor treats multiple myeloma by inhibiting myeloma cell proliferation and promoting myeloma cell apoptosis.

[0011] Further preferably, the myeloma cells are RPMI8226 cells or MM.1S cells.

[0012] Beneficial effects:

[0013] The present invention finds that DKC1 can be used as a new target for treating multiple myeloma. By inhibiting the expression of DKC1, the proliferation of myeloma cells can be inhibited and the apoptosis of myeloma cells can be promoted, thereby slowing down the growth of the tumor and achieving the effect of effectively treating multiple myeloma. The present invention provides a new idea for the treatment of multiple myeloma and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Relative expression levels of DKC1 at the mRNA level in DKC1 knockdown and DKC1 overexpressing myeloma stable cell lines.

[0015] Figure 2 The relative expression levels of DKC1 at the protein level in DKC1 knockdown and DKC1 overexpressing myeloma stable cell lines.

[0016] Figure 3 To investigate the effect of inhibiting or overexpressing DKC1 on the proliferation ability of myeloma stable cell lines.

[0017] Figure 4 The effect of pyrazocin on the proliferation ability of myeloma cells.

[0018] Figure 5 To investigate the effects of inhibiting or overexpressing DKC1 on the cloning ability of stable myeloma cell lines.

[0019] Figure 6 The effect of pyrazoline on the cloning ability of myeloma cells.

[0020] Figure 7 To inhibit the effect of DKC1 on apoptosis of stable myeloma cell lines.

[0021] Figure 8 Effect of pyrazocin on apoptosis of myeloma cells.

[0022] Fig. 9 The effect of overexpression of DKC1 on apoptosis of stable myeloma cell lines under normal (10% FBS) and starvation (0% FBS) conditions.

[0023] Fig.10 This is a statistical graph showing the effect of overexpression of DKC1 on apoptosis of stable myeloma cell lines under starvation (0% FBS) conditions.

[0024] Fig.11 This is the tumor formation situation of myeloma-bearing mice with stable knockdown of DKC1.

[0025] Fig.12 The therapeutic effect of pyrazocin on myeloma. DETAILED DESCRIPTION

[0026] The following is explained in conjunction with specific embodiments:

[0027] Source of experimental materials:

[0028] psPAX2 and pMD2.G were purchased from Shanghai Genetech Co., Ltd.

[0029] Lipofectamine 3000 transfection reagent, opti-MEM medium, fetal bovine serum (FBS), and RPMI 1640 medium were purchased from Thermo Fisher Scientific.

[0030] Example 1: Construction and identification of DKC1 knockdown and DKC1 overexpressing myeloma stable cell lines

[0031] 1. Construction of Stable Cell Lines

[0032] RPMI8226 and MM.1S are multiple myeloma cell lines and can be cultured in RPMI 1640 medium containing 10% FBS.

[0033] (1) Construction of DKC1 knockdown RPMI8226 stable cell line:

[0034] The siDKC1 sequence (GCTCAGTGGCTGTATGATA) was double-digested with AgeI and EcoR I, and then ligated to the linear GL427 vector (pSLenti-U6-CMV-EGFP-F2A-Puro-WPRE) that had been double-digested with the same enzymes using T4 ligase to obtain the recombinant vector A.

[0035] 293T cells (ATCC CRL-3216) were used as tool cells, and recombinant vector A: psPAX2: pMD2.G were mixed in a mass ratio of 4:3:1. Lipofectamine 3000 transfection reagent was used to assist in transfection of 293T cells to package lentivirus. The cells were incubated in an incubator for 72 hours, and the cell supernatant was collected and centrifuged at 100,000 rpm for 2 hours in an ultracentrifuge. The supernatant was removed and the precipitate was resuspended with PBS buffer to obtain lentivirus A.

[0036] The virus titer was determined by infecting 293T cells with lentivirus A at 3×10 8 It can be used if the concentration is above TU / mL.

[0037] RPMI8226 cells were resuspended in Opti-MEM medium and then cultured at 2 × 10 5 The cells were inoculated into 24-well plates at a density of 100 cells / well, and lentivirus A was added at an MOI of 20 (multiplicity of infection, the ratio of virus amount to cell number). After incubation in the incubator for 12 h, the medium was replaced with RPMI 1640 medium containing 10% FBS and continued to be cultured. After 3 days, 1×10 5 The percentage of GFP positive cells was detected by flow cytometry, which was the virus infection positive rate. Puromycin with a final concentration of 2 μg / mL was added to the cells. After 2 days, the uninfected cells died and shattered. The surviving cells were positive cells. The positive cells were cultured and expanded to obtain the DKC1 knocked-down RPMI8226 stable cell line (RPMI8226 knock-down).

[0038] The unrelated sequence MOCK (5'-CCTAAGGTTAAGTCGCCCTCG-3') was connected to the GL427 vector according to the same method as above, and then the MOCK lentivirus was prepared and infected with RPMI8226 cells according to the same method as above to obtain RPMI8226MOCK-A as a blank control group.

[0039] (2) Construction of DKC1 knockdown MM.1S stable cell line:

[0040] Different from step (1), RPMI8226 cells were replaced with MM.1S cells to obtain a DKC1 knocked-down MM.1S stable cell line (MM.1S knock-down); at the same time, MM.1S MOCK was constructed as a blank control group.

[0041] (3) Construction of DKC1 overexpressing RPMI8226 stable cell line:

[0042] The sequence with accession number NM_001363.5 in GenBank was used as the target gene, and the target gene was connected to the GL107 vector (pSLenti-EF1-EGFP-P2A-Pur0-CMV-MCS-3xFLAG-WPRE) to obtain recombinant vector B.

[0043] The recombinant vector B was used to prepare lentivirus B in the same manner as step (1) and infected with RPMI8226 cells to obtain a DKC1 overexpressing RPMI8226 stable cell line (RPMI8226 overexpression); RPMI8226 MOCK-B was also constructed as a blank control group.

[0044] 2. Identification of Stable Cell Lines

[0045] (1) RT-qPCR identification:

[0046] The stable cell lines constructed above (RPMI8226 knockdown and RPMI8226 MOCK-A, MM.1S knockdown and MM.1S MOCK, RPMI8226 overexpression and RPMI8226 MOCK-B) were centrifuged and resuspended; counted, and 1×10 6 cells, extracted cell mRNA and reverse transcribed it into cDNA; the relative expression of DKC1 at the mRNA level was detected by real-time fluorescence quantitative PCR (RT-qPCR) using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene as the internal reference gene.

[0047] Among them, the RT-qPCR primers used to identify DKC1 are DKC1-F and DKC1-R, and the primer sequences are shown in SEQ ID NOs.1~2 respectively; the RT-qPCR primers used to identify GAPDH are GAPDH-F and GAPDH-R, and the primer sequences are shown in SEQ ID NOs.3~4 respectively.

[0048] RT-qPCR test results are as follows Figure 1 As shown, Figure A shows the expression of DKC1 in RPMI8226 knockdown and RPMI8226 MOCK-A, Figure B shows the expression of DKC1 in MM.1S knockdown and MM.1S MOCK, and Figure C shows the expression of DKC1 in RPMI8226 overexpression and RPMI8226 MOCK-B.

[0049] (2) Western blot identification:

[0050] Take 1×10 6 The cells were lysed with RIPA lysis buffer to prepare protein samples; β-actin was used as the internal reference protein, and the relative expression of DKC1 at the protein level was detected by Western blot.

[0051] The protein concentration of protein samples was determined by the BCA method. The same amount of protein samples were separated by SDS-PAGE gel electrophoresis and transferred to PVDF membrane by a membrane transfer instrument. The membrane was blocked with 5% skim milk powder at room temperature for 2 h, and anti-human DKC1 antibody was added at 4°C overnight. The membrane was washed with TBST, and secondary antibody labeled with horseradish peroxidase was added and incubated at room temperature for 1 h. The membrane was washed with TBST and developed with chemiluminescent substrate.

[0052] Western blot test results Figure 2As shown, Figure A shows the expression of DKC1 in RPMI8226 knockdown and RPMI8226 MOCK-A, Figure B shows the expression of DKC1 in MM.1S knockdown and MM.1S MOCK, and Figure C shows the expression of DKC1 in RPMI8226 overexpression and RPMI8226 MOCK-B.

[0053] Depend on Figure 1~2 It was found that the expression of DKC1 at the mRNA and protein levels in the stable cell lines "RPMI8226 knockdown" and "MM.1S knockdown" was significantly lower than that in the blank control group; the expression of DKC1 at the mRNA and protein levels in the stable cell line "RPMI8226 overexpression" was significantly higher than that in the blank control group. The above results show that the myeloma stable cell lines with DKC1 knockdown and DKC1 overexpression were successfully constructed.

[0054] Example 2: Effect of inhibition or overexpression of DKC1 on the proliferation ability of myeloma stable cell lines

[0055] 1. EdU proliferation assay

[0056] The stable cell lines constructed in Example 1 (RPMI8226 knockdown and RPMI8226 MOCK-A, MM.1S knockdown and MM.1S MOCK, RPMI8226 overexpression and RPMI8226 MOCK-B) were respectively cultured at 2×10 5 The cells were seeded into a 6-well plate at a density of 100 cells / well, and EDU (5-ethynyl-2'deoxyuridine) reagent was added. After 2 hours, the cells were collected and fixed and permeabilized using the EDU kit. Finally, the proportion of positive cells, that is, the proportion of proliferating cells, was detected by flow cytometry.

[0057] EDU is a new type of thymidine analog that can replace thymidine and be incorporated into newly synthesized DNA during DNA synthesis. On the other hand, the acetylene group on EDU can react covalently with the fluorescently labeled small molecule azide probe through the catalysis of monovalent copper ions to form a stable triazole ring. This reaction is very rapid and is called a click reaction. Through the click reaction, the newly synthesized DNA will be labeled with the corresponding fluorescent probe Alexa Fluor 555, and the fluorescence of Alexa Fluor 555 can be received by the PE (phycoerythrin) channel, so that the proliferating cells can be detected by the fluorescence intensity of the corresponding PE channel in the flow cytometer.

[0058] The results are as follows Figure 3As shown, A to C show the cell proliferation of RPMI8226 knockdown and RPMI8226 MOCK-A, D to F show the cell proliferation of MM.1S knockdown and MM.1S MOCK, and G to I show the cell proliferation of RPMI8226 overexpression and RPMI8226 MOCK-B. Figure 3 It can be seen that the proportion of RPMI8226 and MM.1S proliferating cells was significantly reduced after DKC1 knockdown; after DKC1 overexpression, the proportion of RPMI8226 proliferating cells increased; this indicates that inhibiting the expression of DKC1 can significantly inhibit the proliferation of myeloma cells.

[0059] Pyrazomycin is a pyrimidine nucleoside analog that can inhibit the catalytic activity of dyskeratin and can be used as a DKC1 inhibitor. RPMI8226 cells were treated with 0nM, 0.2nM, 0.4nM, and 0.8nM pyrazomycin for 72h, and then the cells were incubated at 2×10 5 The cells were seeded at a density of 100 cells / well into a 6-well plate, and the proportion of proliferating cells was detected using the same method as above.

[0060] The results are as follows Figure 4 As shown, Figures A to D show the proliferation of RPMI8226 cells after treatment with 0nM, 0.2nM, 0.4nM, and 0.8nM pyrazolomycin, and Figure E shows the statistical result of cell proliferation ratio. Figure 4 It can be seen that compared with Figure A, after treatment with 0.2nM, 0.4nM, and 0.8nM concentrations of pyrazoline, the proportion of RPMI8226 proliferating cells decreased, among which 0.4nM and 0.8nM concentrations of pyrazoline can significantly inhibit the proliferation of myeloma cells.

[0061] 2. Soft agar colony formation experiment

[0062] Agar was mixed with 2×RPMI 1640 medium to prepare agar with concentrations of 0.55% and 0.3%, respectively. 0.55% agar was added to a 6-well plate to form the lower layer, and then 1×10 3 0.3% agar of the three stable cell lines (RPMI8226 knockdown and RPMI8226 MOCK-A, MM.1S knockdown and MM.1S MOCK, RPMI8226 overexpression and RPMI8226 MOCK-B) was used as the upper layer; 100 μL of RPMI 1640 medium containing 10% FBS was added to the upper surface twice a week to avoid drying. Once colony formation was visible to the naked eye, photos were taken using a camera and microscope, and cells were counted using imageJ software.

[0063] The results are as follows Figure 5As shown, A~C are the cell clone numbers of RPMI8226 knockdown and RPMI8226 MOCK-A, D~F are the cell clone numbers of MM.1S knockdown and MM.1S MOCK, and G~I are the cell clone numbers of RPMI8226 overexpression and RPMI8226 MOCK-B. Figure 5 It can be seen that the number of RPMI8226 cell and MM.1S cell clones decreased significantly after DKC1 knockdown; the number of RPMI8226 cell clones increased after DKC1 overexpression; this indicates that inhibiting the expression of DKC1 can significantly inhibit the cloning of myeloma cells.

[0064] Agar was mixed with 2×RPMI 1640 medium to prepare agar concentrations of 0.55% and 0.3%, respectively; 0.55% agar was added to a 6-well plate to form the lower layer, and then 1×10 3 RPMI8226 cells and 0.3% agar with different concentrations of pyrazomycin were used as the upper layer, where the concentrations of pyrazomycin were 0 nM, 0.2 nM, 0.4 nM, and 0.8 nM respectively; 100 μL of RPMI 1640 medium containing 10% FBS was added to the upper surface twice a week to prevent drying. Once colony formation was visible to the naked eye, photos were taken using a camera and microscope, and the cells were counted using imageJ software.

[0065] The results are as follows Figure 6 As shown. Figure 6 It can be seen that compared with 0 nM, the number of RPMI8226 cell clones decreased after treatment with 0.2 nM, 0.4 nM, and 0.8 nM pyrazoline, which indicates that pyrazoline can inhibit the proliferation of myeloma cells.

[0066] 3. Cell apoptosis experiment

[0067] The effect of DKC1 inhibition or overexpression on myeloma cell apoptosis was detected by Annexin V-PE / 7-AAD (Annexin V-phycoerythrin / 7-aminoactinomycin D) cell apoptosis detection kit.

[0068] In the early stage of apoptosis, phosphatidylserine on the cell membrane will be externalized to the cell surface. Annexin V can specifically bind to the externalized phosphatidylserine. Therefore, when using Annexin V-PE for labeling, the fluorescence signal can be detected through the Annexin V-PE channel of the flow cytometer. As the apoptosis process progresses, the integrity of the cell membrane is gradually lost. At this time, the 7-AAD nucleic acid fluorescent dye can bind to the DNA in the cell nucleus and emit corresponding fluorescence. Therefore, when Annexin V-PE and 7-AAD are used in combination, early apoptotic cells (Annexin V+ / 7-AAD-) and late apoptotic cells (Annexin V+ / 7-AAD+) can be distinguished.

[0069] The stable cell lines constructed in Example 1 (RPMI8226 knockdown and RPMI8226 MOCK-A, MM.1S knockdown and MM.1S MOCK) were centrifuged, and 100 μL Binding Buffer was added to resuspend the cell pellet; Annexin V-PE and 7-AAD antibodies were added and incubated at room temperature for 10 minutes; finally, 400 μL Binding Buffer was added for flow cytometry detection.

[0070] The results are as follows Figure 7 As shown, Figures A to C show the apoptosis of cells knocked down by RPMI8226 and RPMI8226 MOCK-A, and Figures D to F show the apoptosis of cells knocked down by MM.1S and MM.1S MOCK. Figure 7 It can be seen that the apoptotic rate of RPMI8226 cells and MM.1S cells increased significantly after DKC1 knockdown.

[0071] RPMI8226 cells were treated with 0nM, 0.2nM, 0.4nM, and 0.8nM pyrazolomycin, respectively. After 72h, the cells were collected and centrifuged, and 100μL Binding Buffer was added to resuspend the cell pellet; Annexin V-PE and 7-AAD antibodies were added and incubated at room temperature for 10min; finally, 400μL Binding Buffer was added for flow cytometry detection.

[0072] The results are as follows Figure 8 As shown, Figures A to D show the apoptosis of RPMI8226 cells after treatment with 0nM, 0.2nM, 0.4nM, and 0.8nM pyrazolomycin, respectively, and Figure E shows the statistical results of the apoptosis ratio. Figure 8 It can be seen that after treatment with pyraclostrobin, the apoptosis rate of RPMI8226 cells increased significantly, which indicates that pyraclostrobin can promote the apoptosis of myeloma cells.

[0073] The stable cell lines (RPMI8226 overexpression and RPMI8226 MOCK-B) constructed in Example 1 were cultured in RPMI 1640 medium containing 10% FBS and 0% FBS for 24 h, 48 h, and 72 h, respectively; centrifuged, and 100 μL Binding Buffer was added to resuspend the cell pellet; Annexin V-PE and 7-AAD antibodies were continued to be added, and incubated at room temperature for 10 min; finally, 400 μL Binding Buffer was added, and flow cytometry detection was performed.

[0074] Cell apoptosis Fig. 9 As shown, Figures A to C show the cell apoptosis of RPMI8226 MOCK-B when cultured in medium containing 10% FBS for 24h, 48h and 72h, respectively; Figures D to F show the cell apoptosis of RPMI8226 overexpressed when cultured in medium containing 10% FBS for 24h, 48h and 72h, respectively; Figures G to I show the cell apoptosis of RPMI8226 MOCK-B when cultured in medium containing 0% FBS for 24h, 48h and 72h, respectively; Figures J to L show the cell apoptosis of RPMI8226 overexpressed when cultured in medium containing 0% FBS for 24h, 48h and 72h, respectively.

[0075] The statistical results of cell apoptosis ratio are as follows Fig.10 As shown, Figure A shows the apoptotic ratio of cells overexpressing RPMI8226 and RPMI8226MOCK-B when cultured in medium containing 0% FBS for 24 h, Figure B shows the apoptotic ratio of cells overexpressing RPMI8226 and RPMI8226 MOCK-B when cultured in medium containing 0% FBS for 48 h, and Figure C shows the apoptotic ratio of cells overexpressing RPMI8226 and RPMI8226 MOCK-B when cultured in medium containing 0% FBS for 72 h.

[0076] Depend on Figures 9-10 It was found that overexpression of DKC1 could inhibit apoptosis of myeloma cells under starvation (0% FBS) (cell stress) conditions.

[0077] Example 3: Construction and observation of a DKC1 stable knockdown myeloma mouse model

[0078] (1) Construction of a DKC1 stable knockdown myeloma mouse model

[0079] RPMI8226 knockdown cells in the logarithmic growth phase were selected for washing and counting. 8×10 6The cells were suspended in 100 μL RPMI 1640 medium, mixed with 100 μL matrix gel, and slowly injected into the subcutaneous part of the right forelimb of immunodeficient mice at an injection dose of 200 μL / mouse to construct a DKC1 stable knockdown myeloma mouse model as the experimental group;

[0080] RPMI8226 MOCK-A cells in the logarithmic growth phase were selected for washing and counting, and injected into immunodeficient mice according to the same method as above to construct a myeloma tumor-bearing mouse model as a control group.

[0081] When the tumor volume in the control group mice reached 150mm 3 After the tumor was formed, it was recorded as the 0th day of the experiment. Then, the long and short diameters of the tumors of the two groups of mice were measured in vitro with a vernier caliper every 2 days, and the tumor volume was calculated. When the long diameter of the tumor of a mouse in the control group exceeded 15 mm or there was no food and water, the measurement endpoint was taken, the mouse was dissected, and the tumor was taken, photographed and weighed.

[0082] The tumor volume calculation formula is: V = π / 6 × L × W 2 ; L represents the major diameter, and W represents the minor diameter.

[0083] The results are as follows Fig.11 As shown, Figure A is a photo of the tumors of the two groups of mice, Figure B shows the changes in the tumor volumes of the two groups of mice within 0 to 8 days after the start of the experiment, and Figure C shows the tumor weights of the two groups of mice after dissection.

[0084] Depend on Fig.11 It was found that compared with the control group, the myeloma formation time in mice after knockdown of DKC1 was later than that in the control group, the tumor growth rate was significantly slowed down, the tumor volume was significantly reduced, and the tumor weight was significantly reduced.

[0085] Example 4: The therapeutic effect of pyrazocin on myeloma

[0086] RPMI8226 cells in the logarithmic growth phase were selected for washing and counting. 8×10 6 The cells were suspended in 100 μL RPMI 1640 medium, mixed with 100 μL matrix gel, and slowly injected into the subcutaneous part of the right forelimb of immunodeficient mice at an injection dose of 200 μL / mouse to establish a myeloma-bearing mouse model.

[0087] When the tumor volume in the model mice reached 150mm 3 After the tumor was formed, it was recorded as day 0 of the experiment. The myeloma-bearing mice were randomly divided into a control group and a treatment group. The control group was given ddH 2 O, treatment group was given pyrazoline; pyrazoline was administered as follows: intraperitoneal injection, 5 mg / kg, once every 3 days.

[0088] According to the method described in Example 3, the tumor volumes of the two groups of mice were measured every 2 days. The measurement endpoint was when the long diameter of the tumor of a mouse exceeded 15 mm or the mouse had no access to food and water. The mouse was dissected, and the tumor was taken, photographed and weighed.

[0089] The results are as follows Fig.12 As shown, Figure A is a photo of the tumors of the two groups of mice, Figure B shows the changes in the tumor volumes of the two groups of mice within 0 to 12 days after the start of the experiment, and Figure C shows the tumor weights of the two groups of mice after dissection.

[0090] Depend on Fig.12 It was found that compared with the control group, the tumor growth rate in the mice in the treatment group was significantly slowed down and the tumor weight was significantly reduced, which shows that pyrazoline can slow down the progression of myeloma and effectively treat myeloma.

Claims

1. Use of a DKC1 inhibitor in the preparation of a drug for treating multiple myeloma, wherein the DKC1 inhibitor can inhibit the expression of DKC1, and the DKC1 inhibitor is siDKC1 or a lentivirus containing a siDKC1 sequence, and the sequence of the siDKC1 is GCTCAGTGGCTGTATGATA.

2. The use according to claim 1, characterized in that The accession number of the DKC1 mRNA sequence in GenBank is NM_001363.

5.

3. The use according to claim 1, characterized in that The DKC1 inhibitor treats multiple myeloma by inhibiting the proliferation of myeloma cells and promoting the apoptosis of myeloma cells.

4. The use according to claim 3, characterized in that The myeloma cells are RPMI8226 cells or MM.1S cells.

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