Molecluar Mechanism Of Transcription Factor NFATc1 Affecting Cell Division In Colon Cancer By Activating MDM2

Colon cancer,as one of the most malignant cancers,ranks in the top three in both incidence and mortality rates.The existing clinical colon cancer treatments are still unclear.Therefore,it is crucial to further investigate the mechanism of colon cancer development and discover new oncogenes using for targeted therapy.The result of TCGA database analysis showed that NFATc1 was significantly upregulated in clinical colon cancer tissues,and high expression of NFATc1 was associated with a significant decline in prognosis.This suggests that NFATc1 plays a critical role in the development of colon cancer.The result of the immunohistochemical staining of clinical colon cancer tissue samples showed that the expression of NFATc1 was significantly higher in cancer tissue than in adjacent tissue.Through xenograft experiments,we verified that knocking down NFATc1 significantly decreased the tumor proliferation rate of colon cancer cells HCT116.Further cell experiments showed that knocking down NFATc1 significantly reduced the proliferation and migration rates of colon cancer cells,indicating that NFATc1 plays a critical role in the development of colon cancer.Cell cycle out of control is one of the main characteristics of tumor cells.That’s also the main reason for accelerated tumor cell proliferation.Therefore,we first examined the changes in cell cycle-related phenotypes after NFATc1 knocking down.Flow cytometry analysis revealed that the number of cells accumulated in the G1 phase significantly increased after knocking down NFATc1;chromosome staining of the nucleus in the G1 phase showed a significant decrease in micronuclei;chromosome count of dividing cells showed a significant decrease in the number of abnormal chromosome cells.These results collectively indicate that NFATc1 affects multiple stages of the cell division cycle and thus affects the development of colon cancer.The double luciferase reporter gene experiment and Ch IP experiment confirmed that NFATc1 promoted the transcription activity of MDM2 by binding to TTTCCA sites from-303 to-307 of MDM2.In addition,we further confirmed through rescue experiments that NFATc1 promotes the occurrence and development of colon cancer by activating MDM2.Because the activation of calcium channels plays an indispensable role in the occurrence and development of tumors.NFATc1 is one of the calcium channel related genes,and calcium channel inhibitors can inhibit NFATc1 translocation to the nucleus and prevent it from combining with the target gene to play a role.Nifedipine(NIFE)is a dihydropyridine L-type calcium channel blocker.In 2001,it was reported in The Lancet that a patient with metastatic colon cancer was completely relieved after receiving high-dose NIFE treatment.However,the mechanism of how NIFE inhibits the development of this colon cancer patient is still unclear.By using this drug and combining the molecular mechanism found above,we further explore whether NIFE can inhibit the occurrence and development of colon cancer by inhibiting NFATc1/MDM2 pathway.And further combined with oxaliplatin,a commonly used clinical colon cancer drug,for joint treatment.The double luciferase reporter gene experiment and Ch IP experiment confirmed that NFATc1 promoted the transcription activity of MDM2 by binding to TTTCCA sites from-303 to-307 of MDM2 promoter.In addition,rescue experiments confirmed that NFATc1 promotes the occurrence and development of colon cancer by activating MDM2.Because the activation of calcium channels plays an indispensable role in the occurrence and development of tumors.NFATc1 is one of the calcium channel related genes,and calcium channel inhibitors can inhibit NFATc1 translocation to the nucleus and prevent it from combining with the target gene to play a role.Nifedipine(NIFE)is a dihydropyridine L-type calcium channel blocker.In 2001,it was reported in The Lancet that a patient with metastagtic colon cancer was completely relieved after receiving high-dose NIFE treatment.However,the mechanism of how NIFE inhibits the development of this colon cancer patient is still unclear.By using this drug and combining the molecular mechanism found above,we further explore whether NIFE can inhibit the development of colon cancer by inhibiting NFATc1/MDM2 pathway.And further result investigated that NIFE cotreated with oxaliplatin,a commonly used clinical colon cancer drug,can improve the therapeutic effect.Base on the above results,NFATc1 can inhibit p53/p21 pathway by activating MDM2,and affect the normal operation of colon cancer cell cycle.NIFE can inhibit the development of colon cancer by targeting NFATc1/MDM2 pathway.The molecular mechanism of NIFE as an antitumor drug was clarified,which provided a theoretical basis for NFATc1 as a new target of antitumor drugs.