Sulforaphane Increases The Sensitivity And Apoptotic Effect Of Paclitaxel In MyD88~+ Human Ovarian Cancer Cells

Background and objectives:Ovarian cancer is one of the common malignant tumor of female reproductive system.The mortality rate of ovarian cancer ranks first among gynecological tumors.It is difficult to detect in early stage,and it is often diagnosed in advanced stage.Tumor cytoreductive surgery and adjuvant chemotherapy are the basic treatments for ovarian cancer.At present,paclitaxel combined with carboplatin intravenous chemotherapy is the first-line chemotherapy regimen for ovarian cancer,and drug resistance leads to the shortening of progression-free survival and low survival rate of ovarian cancer patients.Paclitaxel mainly relies on TLR4/MyD88 signaling pathway,which causes the release of many cytokines,promotes the proliferation of tumors and leads to chemotherapy resistance.Some studies have found that sulforaphane and cysteine residues in the extracellular domain of MD-2 form adducts,which inhibit the formation of TLR4/MD-2 dimer,thus blocking the downstream signal transduction of NF-KB cells and the secretion of pro-inflammatory cytokines such as IL-6 in the TLR4/MyD88 signaling pathway.It can be inferred that sulforaphane can block the chemotherapeutic resistance induced by paclitaxel activating TLR4/MyD88 signaling pathway,which may enhance the sensitivity of ovarian cancer cells to paclitaxel and increase the apoptosis of cancer cells.The purpose of this study is to further confirm that sulforaphane can increase the sensitivity of ovarian cancer cells to paclitaxel and the apoptosis of cancer cells by dectecting cell viability and apoptosis,in order to find new therapeutic drugs or chemosensitizers for ovarian cancer,and provide a new way to solve the problem of low survival rate of ovarian cancer caused by paclitaxel resistance,and to improve the prognosis and overall survival rate of ovarian cancer patients..Methods:1?The concentration range of sulforaphane was investigated by using crystal violet assay,and respectively determined the survival rate of OVCAR-3 and A2780cells induced by sulforaphane and paclitaxel after 72 hours.2?The inhibitory effect of paclitaxel combined with sulforaphane on growth of human ovarian cancer OVCAR-3 and A2780 cells by using crystal violet assay,and compared the growth inhibition of paclitaxel combined with sulforaphane and paclitaxel alone.3?The apoptotic rate of human ovarian cancer OVCAR 3 and A2780 cells treated with sulforaphane,paclitaxel and paclitaxel combined with sulforaphane at different time by using flow cytometry,and compared the apoptotic rates of paclitaxel combined with sulforaphane with paclitaxel alone.Results:1?The viabilitive rate of human ovarian cancer A2780?OVCAR-3 cells decreased with the respectively increase of sulforaphane and paclitaxel concentration.The IC₂₀0 value of A2780 and OVCAR-3 cells treated with sulforaphane for 72 hours were respectively 2.231±0.318?mol/L and 2.374±0.227?mol/L;IC₅₀0 value were8.780±1.698?mol/L and 10.970±1.540?mol/L.There was no significant difference in IC₅₀0 values between the two cell lines treated with sulforaphane?P>0.05?.The IC₂₀value of paclitaxel treated human ovarian cancer A2780 and OVCAR-3 cells for 72hours were respectively 0.0027±0.0001?mol/L and 0.0047±0.0005?mol/L,IC₅₀0 value were 0.028±0.004?mol/L and 0.044±0.004?mol/L.The results showed that the IC₅₀values of ovarian cancer A2780 cells treated with paclitaxel were significantly lower than that of ovarian cancer OVCAR-3 cells?P<0.05?,indicating that paclitaxel had stronge rgrowth inhibition to ovarian cancer A2780 cells than that OVCAR-3 cells.2?In OVCAR-3 cells,the IC₅₀0 value of paclitaxel combined with sulforaphane(IC₂₀)was 0.032±0.003?mol/L after 72 hours incubated.The IC₅₀0 value of paclitaxel combined with sulforaphane(IC₂₀)was significantly lower than that of paclitaxel alone?0.044±0.004?mol/L??P<0.05?.It illustrated that sulforaphane can increase cytotoxicity of paclitaxel on OVCAR-3 cells.In A2780 cells,the IC₅₀0 value of paclitaxel was 0.025±0.004?mol/L after 72 hours incubated by paclitaxel combined with sulforaphane(IC₂₀).The IC₅₀0 value of paclitaxel combined group was not different from that of paclitaxel alone?0.028±0.004?mol/L??P>0.05?.These results suggest that sulforaphane does not increase the cytotoxicity of paclitaxel to A2780cells.3?The apoptotic cells of A2780 and OVCAR-3 cells treated with paclitaxel(IC₅₀)gradually increased over time?P<0.05??The total apoptotic rates of A2780 cells treated with paclitaxel(IC₅₀)were 8.23%and 18.44%respectively after 15 hours and30 hours,and those of OVCAR-3 cells treated with paclitaxel(IC₅₀)were 8.14%and14.27%respectively.The results showed that there was no significant difference in apoptotic rate between the two cell lines A2780 and OVCAR-3 after 15 hours?P>0.05?,but the apoptotic rate of A2780 after 30 hours was significantly higher than that of OVCAR-3?P<0.05?,suggesting that paclitaxel has a stronger apoptotic effect on ovarian cancer A2780 cells.There was no significant difference in apoptotic changes of human ovarian cancer A2780 and OVCAR-3 cells treated with sulforaphane(IC₂₀)over time?P>0.05?.In OVCAR-3 cells,the apoptotic rate of paclitaxel(IC₅₀) combined with sulforaphane(IC₂₀)was significantly higher than that of paclitaxel (IC₅₀)alone group?P<0.05?,while in A2780 cells,the apoptotic effects of paclitaxel combined with sulforaphane and single drug group had no significant difference?P>0.05?.The results showed that sulforaphane could enhance the apoptotic effect of paclitaxel on OVCAR-3 cells,and A2780 cells had no such effect..Conclusions:Sulforaphane and paclitaxel have dose-dependent growth inhibition and time-dependent apoptosis-promoting effects to human ovarian cancer A2780 cells?MyD88-negative?and OVCAR-3 cells?MyD88-positive?,and paclitaxel has stronger growth inhibition and apoptosis-promoting effects to ovarian cancer MyD88-negative cell lines.Sulforaphane can significantly improve the sensitivity and apoptotic effect of paclitaxel to MyD88-positive ovarian cancer cells.