| Thyroid cancer is the most common malignant tumor in the human endocrine system,and it occurs mostly in women.In recent years,the incidence of thyroid cancer in China and the world has increased year by year,and it has become one of the killers threatening human life,especially women's health.Most patients with thyroid cancer have a good prognosis after surgery and radioactive iodine,but a small number of patients still have poor prognosis due to tumor heterogeneity,and there is no clear treatment plan.In order to improve the prognosis of patients,the development of accurate and effective targeted treatment programs has become a hot spot in thyroid cancer research.At present,the clinical application of epigenetics in the treatment of cancer has received extensive attention.Many tumor tissues undergo changes in epigenetic modifications such as DNA methylation,histone modification,non-coding RNA regulation,and chromosomal remodeling,which are closely related to tumor development.In theory,epigenetic modification can be reversed under certain conditions,and this feature has important significance in the treatment of tumors.MOF is a member of the MYST family of histone acetyltransferases,also known as MYST1.MOF plays a biological role mainly in the formation of MSL protein complexes and NSL protein complexes.It can specifically catalyze the acetylation of histone 4 at 16th lysine and also catalyze non-histones such as p53 at position 120th lysine.Studies have shown that MOF plays an important role in embryonic development,DNA damage repair,tumor development and maintenance of chromosome stability.It has been reported that MOF expression is significantly up-regulated in primary non-small cell lung cancer tissues.While,MOF expression shows a downward trend in primary cancer tissues such as gastric cancer,hepatocellular carcinoma,and colorectal cancer.These suggest that MOF plays different roles in different tumors.However,the role and molecular mechanism of MOF in thyroid cancer is not clear,which provides a broad research prospect for our research and new insights for targeted therapy of thyroid cancer.Research purposes:The expression levels of MOF in thyroid cancer were determined by human thyroid cancer tissue microarray,paracancerous and cancerous pathological tissues of thyroid cancer patients as well as thyroid cancer cell lines;BHP-10-3 and TT2609 thyroid cancer cell lines were studied.MOF was knocked down by the method of lentivirus infection in the two cell lines,and the effect of MOF on various life activities of thyroid cancer cells was studied.The relationship between VEGFR2 and MOF expression was determined in thyroid cancer cells lines with knockdown of MOF,and we explored its molecular mechanism.Research methods:1.Using the purchased tissue chip of thyroid cancer,immunohistochemical staining method to determine the expression level of MOF in thyroid cancer tissue;using 20 clinical samples collected and thyroid cancer cell lines,through Western Blot methods to determine the expression level of MOF in thyroid cancer;2.BHP-10-3 and TT2609 cells were infected with the interfering MOF and the control interfering virus,respectively,and the monoclonal cells and the control monoclonal cell strain stably knocking down the MOF were obtained by screening and expanding the culture by puromycin.The effects of knockdown of MOF on proliferation and cell cycle of thyroid cancer cells were determined by CCK8,EdU staining,colony formation and flow cytometry;3.Using the above two BHP-10-3 and TT26909 cell lines and control cell lines stably knocking down MOF,Annexin V FITC-PI double staining flow cytometry and detection of apoptosis-related proteins were performed to determine knockdown of MOF;4.The expression levels of VEGFR2 in BHP-10-3 and TT26909 cells were detected by qRT-PCR and Western Blot.The interaction between MOF and VEGFR2 was verified by ChIP research with MOF antibody.The interference between MOF and VEGFR2 was detected by Western Blot.Changes in PI3K/AKT signaling pathway-related proteins downstream of VEGFR2 in BHP-10-3 and TT2609 cell lines;5.BHP-10-3 and TT2609 cells were treated with histone acetyltransferase inhibitor MG149.After inhibiting MOF activity,the changes of VEGFR2 and its downstream PI3K/AKT signaling pathway-related proteins were detected by Western Blot.Results:1.In thyroid cancer tissue microarray,thyroid cancer clinical samples,thyroid cancer cell lines,the expression of MOF is significantly higher than normal tissues and cells;2.After using lentivirus to interfere with MOF expression in BHP-10-3 and TT2609 cell lines,cell proliferation ability was significantly weakened,and the cell cycle was blocked in the G1 phase;3.Compared with the control cell line,the apoptosis level of two thyroid cancer cell lines with knock down of MOF increased significantly;4.Compared with the control cell line,the expression level of VEGFR2 was down-regulated in two thyroid cancer cell lines with knock down of MOF,and phosphorylated AKT expression was down-regulated.ChIP experiment indicates that MOF can be enriched in the VEGFR2 promoter region;5.After MG149 inhibited the function of MOF in BHP-10-3 and TT2609 cells,the expression of VEGFR2 protein was down-regulated,and phosphorylated AKT expression was down-regulated.Conclusion:1.MOF plays an important role in thyroid cancer,and it is highly expressed in most thyroid cancer tissues and cell lines;2.Knock down of MOF in thyroid cancer cell lines significantly reduced cell proliferation rate and increased cell apoptosis level;3.MOF can interact with the VEGFR2 gene promoter at the transcriptional level to mediate the PI3K/AKT pathway,and has an influence on the proliferation and apoptosis of thyroid cancer cells. |
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