NF-kB Pathway Inhibitor Curcumin Reverses The Polarization Of M2 Macrophage By Low Dense Sorafenib

ObjectivesOur previous studies have confirmed that high expression of macrophage in peritumor area was negatively correlated with the prognosis of the patients with HCC.Furthermore,our studies also found that liposome or Zoledronic phosphonic acid could significantly enhance the therapeutic effect of sorafenib in the orthotopic liver cancer model by scavenging the macrophages.Our study has also confirmed that low dose Sorafenib promoted macrophages polarization to M2 macrophages(tumor associated macrophages),and some clinical studies showed that plasma levels of sorafenib in patients may decline over time.Therefore,we postulated that low dose Sorafenib induced M2 macrophage polarization may be associated with resistance of Sorafenib.It has been reported that polarization of M2 macrophages is associated with NF-kB signaling pathway.Our previous studies have also confirmed that low dose sorafenib activated the NF-kB signaling pathway by inhibiting the P50 enter nucleus and intervene the polarization of M2 macrophages,inhibiting the invasion and metastasis of HCC,and interfere with the drug resistance of sorafenib.Moreover,the NF-kB signaling pathway inhibitor Bay11-7082 can decrease the degree of lung metastasis in mice by reverse the pro-tumor effect of sorafenib treated macrophage.This study aimed to confirm if low dose Sorafenib could promote the polarization of M2 macrophages and invasion and metastasis of HCC in mice.Moreover,We hope to overcome the resistance of Sorafenib by interfering with the polarization of M2 macrophages by using curcumin,which is a NF-kB signaling pathway inhibitor that has been applied to clinical practice.Methods1,We established the orthotopic liver cancer model and randomly divided these mice into four groups including control group,sorafenib group,curcumin group and combination group.After 3 weeks of oral gavage,we sacrificed these mice and obtained tumor specimens and compared the differences of the diameter of tumors.2,We also obtained the peripheral blood and spleens of mice and compared the proportion of M1 and M2 macrophages in the peripheral blood and the single cellsuspension of the spleen by flow cytometry.Results1,In HCC samples,compared to the control group,the tumor diameter in sorafenib group tended decreased,and tumor diameter in combination group significantly decreased(P<0.05).Tumor diameter in the combination group also decreased significantly compared to that in sorafenib group.2,In peripheral blood,compared to the control group,the proportion of M1、M2、M1+M2 macrophages increased significantly in the sorafenib group(P<0.05),while the ratio of M2/M1 tends to increase in the sorafenib group.The proportion of M1 、 M2 、 M1+M2macrophages did not change significantly in the combination group,but the proportion of M2/M1 decreased significantly in the sorafenib group(P<0.05).3,In spleens,compared to the control group,the proportion of M1 、 M2 、 M1+M2macrophages did not change significantly in the sorafenib group,the ratio of M2/M1 decreased significantly in the sorafenib group(P<0.05).However,the proportion of M1、M2、M1+M2 macrophages increased significantly in the combination group(P<0.05),while the ratio of M2/M1 increased significantly in the sorafenib group(P<0.05).Conclusions1,In peripheral blood,Low dose Sorafenib causes M1,M2 and total macrophages increase significantly,and the polarization to M2 trend,it shrinks tumors but not significantly,suggesting that low dose Sorafenib may promote tumor invasion and metastasis via M2 polarization.2,In peripheral blood,curcumin combined with low dose Sorafenib make the trend of M1,M2 and total macrophages increasing significantly offset and reverse the trend of M2 polarization,the tumor is also reduced by inhibiting the invasion and metastasis of tumor cells which is caused by reversing M2 polarization via curcumin.3,In spleen,low dose sorafenib caused no significant change in proportion of M1,M2,M1+M2 macrophages and no polarization of M2 macrophage,and when combined with curcumin,the trend of polarization of M2 macrophages was significant.