Inhibitory Effect Of Long Chain Non Coding RNA MALAT-1 Gene On Human Laryngeal Squamous Cell Carcinoma Hep-2 Cells

Objective: Laryngeal cancer,a type of head and neck cancer,ranks second among all respiratory system tumors.About 2 percent of respiratory malignancies are laryngeal carcinomas.The current treatment for laryngeal cancer includes surgical treatment.Radiotherapy and chemotherapy.Surgery is the most commonly used treatment for laryngeal cancer.The principle of surgical treatment is to preserve the vocal function of the larynx as much as possible with the complete removal of the tumor,with a view to improving the quality of life of patients with laryngeal cancer after surgery.In the past 20 years,clinical treatment of laryngeal cancer has not been satisfactory,according to an epidemiological survey.Therefore,the mechanism of laryngeal carcinogenesis and development at molecular level will be helpful to improve the diagnosis and treatment of laryngeal carcinoma.In this study,we investigated the inhibitory effect of knockout of long chain non-coding RNA MALAT-1 gene on Hep-2 cells of human laryngeal squamous cell carcinoma at the molecular level.Methods: The expression of MALAT1 in Fa Du-Hep-2 and CNE-2Z cells of nasopharyngeal carcinoma（NPC）was detected by real-time polymerase chain reaction（RT-PCR）with immortalized nasopharyngeal epithelial cell line NP-69 as reference.The expression of MALAT1 was detected by RT-PCR in Hep-2 cells transfected with shmalat1 lentivirus.The effect of MALAT-1 on cell proliferation was determined by proliferation rate analysis.Cell cycle and apoptosis were analyzed by flow cytometry.The migration of Hep-2 cells was detected by Transwell chamber.Finally,Matri was used to detect the migration of Hep-2 cells.Gel invasion assay was used to evaluate the invasiveness of Hep-2 cells transfected with shmalat1 and sh Ctrl lentivirus.Results: Using RT-PCR to detect the expression of Hep-2 and Fa Du,nasopharyngeal carcinoma cell line CNE-2Z MALAT1,found that compared with NP-69,Fa Du cells,the expression of Hep-2 and MALAT1 in nasopharyngeal carcinoma CNE-2Z cells increased significantly.By flow cytometry to evaluate Hep-2 cells in different cell cycle phases.Compared with the MOCK and sh Ctrl cell number,MALAT1-sh RNA lentivirus transfected S cells phase cells increased significantly.Knockdown of MALAT1 Hep-2 cell clone ability was significantly impaired,decreased An average of 124 cells were observed in the cells treated with 7.5.sh Ctrl lentivirus,while 115 clones were observed in the MALAT1 knockout cells.Compared with the untransfected MOCK cells or sh Ctrl cells,the apoptosis of Hep-2 cells with MALAT1 knockout increased significantly（P < 0.01）,and inhibited the migration of Hep-2 cells and the invasion of Hep-2 cells.The apoptosis of Hep-2 cells with MALAT1 knockout was significantly increased by 4.83% ±0.15%（P < 0.01）,and inhibited the migration of Hep-2 cells and invasion of Hep-2 cells.Transwell invasion assay.Transwell migration results showed that the migration ability of 24 h after the attack,the migration,and MOCK cells（202 + 6.6）and sh Ctrl cells（170 + 3.8）compared to the number of cells was significantly reduced（118 + 1.6,P <0.01）.Using scratch test evaluated by migration sh MALAT1 or sh Ctrl lentivirus transfected Hep-2 cells after.MOCK-treated,24 h cell scratch migration process after the restoration of29 + 3.In addition,sh Ctrl-treated cells repaired 24 ±3.0 cells.However,the scratches of sh MALAT1 transfected with lentivirus were narrowed only 14 ±0.2%（P < 0.01）.Conclusion: 1.The MALAT1 expression of Hep-2 cells transfected with shmalat1 lentivirus decreased 91.5%.Therefore,shmalat1 lentivirus could effectively affect the expression of MALAT1 and knock out MALAT1 to inhibit the proliferation of Hep-2 cells.2.Compared with MOCK and sh Ctrl cells,the number of S phase cells transfected with MALAT1-sh RNA lentivirus increased significantly（P < 0.01）.In addition,the percentage of cells in G₂ / M phase decreased（P < 0.01）.Due to the loss of MALAT1,the cells were blocked in S phase.3.The ability of knockout MALAT1 to inhibit the cloning of Hep-2 cells was determined by clone formation assay.The cloning ability of Hep-2 cells with knockout MALAT1 was significantly impaired,and the average number of cells treated with MALAT1 decreased by about 7.5.sh Ctrl lentivirus,and an average of 124 cells were observed.115 cloned cells were observed in MALAT1 knockout cells.4.The quantitative analysis of apoptosis by flow cytometry showed that compared with untransfected MOCK cells or sh Ctrl cells,5.74% ±0.22% of Hep-2 cells knocked out MALAT1 cells,the apoptosis of Hep-2 cells was significantly accelerated by 4.83% ±0.15%（P < 0.01）.5.The migration and invasion of Hep-2 cells with knockout MALAT1 were damaged,indicating that MALAT1 plays an important role in these processes of Hep2 cells.6.The low expression of MALAT1 inhibited the migration of Hep-2 cells and confirmed the important role of MALAT1 in the migration of Hep-2 cells.