Experimental Research For The Effect Of AuNRs And EGFRmAb/AuNRs Photothermal Treatment Of Subcutaneous Transplantable Hypopharyngeal Tumor In Nude Mice

Objective:Research the effect of AuNRs and EGFRmAb/AuNRs photothermal treatment of subcutaneous transplantable hypopharyngeal tumor in nude mice,and to explore the correlation between its’anti-tumor effect and PI3K/AKT,DNA injured signaling pathways.Methods:1.To establish a subcutaneous tumor model in nude mice by injection of human hypopharyngeal carcinoma cell lines Fadu.The nude mice were randomly divided into seven groups when the tumor volume approaching 200mm3:Group 1 injection of normal saline directly in tumor;Group2:injection of gold nanorods solution in tumor; Group3:NIR laser irradiation of tumor after intravenous injection of gold nanorods solution for 24h;Group4:NIR laser irradiation of tumor;Group5:NIR laser irradiation of tumor after direct injection of gold nanorods solution for 24h; Group6:injection of EGFRmAb;Goup7:NIR laser irradiation of tumor after direct injection of solution of EGFRmAb/AuNRs for 24h.Observe the growth of tumors, and draw its growth curve, eventually calculate the inhibitory rate for tumor growth.2.Flow cytometry and TUNEL assay were adopted for assessment of apoptosis of the transplanted tumor.3. Q-PCR assay to detect 7 different groups of tumor tissue of the expression of 3 types of mRNA (PTEN,akt,gsk3β) in Akt signaling pathways and 3 types of mRNA(ATR,chkl,p53) in DNA injured pathways.4. Different groups of tumor tissue of the expression of Akt signaling pathways protein (PTEN,p-akt,akt,gsk3β) and DNA injured protein (ATR,chkl,p-p53,p53) were measured by Western Blot.Results:1. Successfully cultivate Fadu cells,and establish a subcutaneous tumor model in nude mice.2. We found that the group 2,group 3 and group 4 all have no effect on tumor suppressor(P>0.05),but there were an obvious anti-tumor effect in group 5,group 6 and group 7, especially in group 7 (P<0.05),it had the highest anti-tumor rate.3. Flow cytometry and TUNEL shows that the group 5,group 6 and group 7 had an effect on inducing apoptosis,obviously the group 7(P<0.05)4. Q-PCR shows that the near-infrared photothermal effect of AuNRs and EGFRmAb/AuNRs and EGFRmAb probably exerted its control by means of inhibiting the expression of mRNA (akt,gsk3β) while activating PTEN mRNA in PI3K/AKT signaling pathway;and initiated DNA injured signaling pathway by activating mRNA (ATR,chk1,p53)5. Western blot manifests that the near-infrared photothermal effect of AuNRs and EGFRmAb/AuNRs and EGFRmAb probably initiated PI3K/Akt signaling pathway by means of inhibiting the expression of protein (p-akt, p-gsk3β)and activating PTEN protein; It exerted its control by means of activating protein (p-ATR, p53,p-chk1)and inhibiting p-p53 protein in DNA injured signaling pathway.Conclusions:1.The near-infrared photothermal effect of AuNRs and EGFRmAb/AuNRs and EGFRmAb all have an inhibitory effect on the growth of subcutaneous transplantable hypopharyngeal tumor in nude mice, the near-infrared photothermal effect of EGFRmAb/AuNRs is more significant.This finding is beginning to be emerge raising hope for photothermal treatment of tumors in vivo targeting.2.The near-infrared photothermal effect of AuNRs and EGFRmAb/AuNRs and EGFRmAb inhibits tumor cells proliferation and induce the apoptosis.Its mechanism is probably closely related to the PI3K/AKT and DNA injured signaling pathways.