Mechanism Of Notch1 Pathway In SUP-B15 Cell Apoptosis Induced By JQ1

Objective:With the Philadelphia chromosome(Ph+) acute lymphocytic leukemia(acute lymphoblastic leukemia, ALL) is a relatively special in the biology of acute leukemia, is originated from B department or T lymphoid progenitor cells and chromosome 22 pairs of chromosomes long arms and long arm to chromosome 9 reciprocal translocation after the BCR- ABL fusion gene of tumor diseases.Ph(+) ALL belong to high-risk leukemia and low response rate, alleviate the time is short, the prognosis is poor.The Ph(+) there are three kinds of the main treatment of ALL: standard chemotherapy, tyrosinase inhibitor,allogeneic hematopoietic stem cell transplantation.Response rate is low, long-term regular chemotherapy patients relieve time is short, long body can not tolerate.With the advent of tyrosine kinase inhibitors, BCR ABL fusion gene in targeted therapy of chronic myelogenous leukemia(chronic myelocytic leukemia, CML) made a great success, then for the treatment of Ph + ALL greatly improves the response rate of disease, but in the process of clinical medication gradually discovered the body resistance.Allogeneic hematopoietic stem cell transplantation as a suitable donor, less expensive, only a minority of patients can transplant.Therefore,to find effective cytotoxic drugs and potential molecular targets is very urgent.In recent years, study abroad JQ1(bromine structure domain protein inhibitors) inhibits chronic myelogenous leukemia(CML) BCR-ABLT315 I gene mutations in the cell proliferation, but the study found that CML chronic phase into acute stage was due to the activation of MSI2- Numb- Notch1 pathway.Ph + ALL also have similar to CML BCR- ABL fusion gene.So JQ1 whether has the inhibitory effect on the Ph+ ALL cells, JQ1 can cut MSI2- Numb- Notch1 pathway to reach the role ofanti-tumor, the study reported for the first at home and abroad.his study observed by the method of in vitro experiments JQ1 SUP- B15 Ph+ ALL cell lines to the person on cell apoptosis inducing effect and of Notch1 pathway MSI2, Notch1, Hes1 gene, discuss in JQ1Ph(+) ALL possible antitumor mechanism, for the treatment of Ph(+) ALL provide new treatments.Methods:1.The experiment adopted four methyl azo thiazole blue method test(determined by MTT method) to detect different concentrations single-agent JQ1 role SUP-B15 cell line proliferation inhibition.2.Experiments using flow cytometry to detect different concentrations single drug JQ1 to SUP-B15 cell cycle of change.3.Real-time fluorescent quantitative polymerase chain reaction(RT-PCR) method to detect different concentration single-agent JQ1 SUP-B15 cell lines MSI2, Notch1, Hes1,Bcr- Ablm RNA expression level decrease.Results:1.The four methyl azo thiazole blue(determined by MTT method to detect the results showed that different concentrations of single-agent JQ1(1μmol/L, 2μmol/L, 4μmol/L)and SUP- B15 cell culture together after 24 h, 48 h, 72 h, SUP- B15 inhibition of cell growth has obvious phenomenon.At 0-4 mol/L concentration range, JQ1 cell growth inhibition rate of the experimental group with the extension of elevated JQ1 drug concentration and action time, dose- time dependence.At the same time, compared with control group, with statistical significance2.Flow cytometry detection SUP- B15 cell cycle result shows: compared with control group, different concentrations of single-agent JQ1(1μmol/L, 2μmol/L, 4μmol/L), after 48 h SUP- B15 cells can induce cell block in S phase, a dose dependent, at the same time,compared with control group, with statistical significance(P < 0.05).3.Real-time fluorescent quantitative polymerase chain reaction(RT-PCR) method to detect the results showed that different concentrations of single drug JQ1(1μmol/L,2μmol/L, 4μmol/L) to SUP- B15 cells after 48 h, with the increase of concentration of JQ1,MSI2, Notch1, Hes1, Bcr- Ablm RNA expression level gradually reduce, in dose dependent, at the same time, compared with control group, the difference was statistically significant(P < 0.05).Conclusions:1.JQ1 can obviously inhibit the growth of SUP- B15 cells, can induce the apoptosis of SUP- B15 cells effectively.2.JQ1 can make SUP- B15 cell block S phase of the cell and a dose dependent, which affects the growth of cells.3.JQ1 may cause the Notch1 signaling pathway in key genes MSI2, Notch1, Hes1 transcription level gradually reduce and a dose dependent, prompt JQ1 to Ph+ ALL cell lines SUP-B15 cell growth inhibition was done by Notch1 signaling pathways, the mechanism is one of JQ1 antitumor mechanism.