Research Of HSP70/HSP90 Rule Of The Expression After Hyperthermia And Inhibition Affect Hyperthermia Curative Effects In Nasopharyngeal Carcinoma In Vivo

OBJECTIVE To study constructing human nasopharyngeal carcinoma HNE1 cellculture and animal model. It provides the material basis. To study co-inhibition ofHSP70/HSP90 synergistically sensitizes nasopharyngeal carcinoma cells to thermotherapyand effect mechanism, which provide cooperation treatment theoretical basis. To studyHSP70/HSP90 inhibition availability of treating nasopharyngeal carcinoma for increasingmedicine curative effect, decreasing dosage and adverse reaction, and practice basis in vivo.METHODS: Exponential growth phase HNE1 cells were subcutaneously inoculated into theright legs of nude mice (6-8 weeks, female). Treatment was started when the volume of thetumor reached 50 mm3. Mice were grouped into6 groups (n = 9 or 11) randomly as follows:untreated, hyperthermia, 17-DMAG plus hyperthermia, quercetin plus hyperthermia,17-DMAG plus quercetin, and 17-DMAG plus quercetin together with hyperthermia. The17-DMAG(15 mg/kg) and quercetin (5 mg/kg) were administered as described previously,and the protocol was adjusted to combine with thermotherapy.. For better heat response invivo, the heat treatments with 43°C for 2 hours were performed2 hours after administration.The mice were then fixed. Heat treatments were performed through dipping the tumor-loadinglegs into preheated water. Tumors were harvested, weighed, and fixed with formalin for furtherexperiments. Tumor tissues were removed from tumor-bearing nude mice. Then cellularapoptosis analysis was performed using a terminal deoxynucleotidyl transferase dUTP nickend labeling (TUNEL) assay according to the manufacturer’s instructions.RESULTS In vivo,the weight of tumors from the group treated with 17-DMAG plus quercetin combined withhyperthermia showed a significant difference when compared with that of the group treatedwith hyperthermia alone, although the tumor-loaded mice were treated twice a week. Owingto the short period of treatment, significant differences were not found between 17-DMAG orquercetin alone plus heat treatment and heat treatment alone. Therefore, we concluded that theco-inhibition of HSP70/HSP90 showed more intensive activity in sensitizing HNE1 cells to heat treatment. To confirm this further, we detected cellular apoptosis with a TUNEL kit. Thecombination of co-inhibition of HSP70/HSP90 and heat treatment resulted in significantlyincreased tumor cell apoptosis. In addition, the treatments with 17-DMAG or quercetin alonewithout hyperthermia were also investigated. Both of the 2 groups showed similar tumorgrowth and little apoptosis with the untreated group (data not shown). Unlike the in vitroeffects, the combination of 17-DMAG plus quercetin without hyperthermia did not displaysignificant antitumor activity in vivo; this may be attributed to decreaseddosage.CONCLUSION our study not only suggests that the changes of the HSP expressionfollowed by thermotherapy are complicated and interactive but also supports the view that theco-inhibition of HSP70 and HSP90 is a preferable strategy for antagonizing activity of HSPsin tumor thermotherapy.