The Study Of Protective Effect Of CXCRI1/2Antagonist G31P On The Renal Injury Of Tumor-bearing Mice Model Induced By High-dose Cisplatin

Objective: Cisplatin (Cis-diammin-odichloroplatinum, DDP)is a cell cyclenon-specificic drugs, which could impair replication and transcription of DNA in cancer cells anddamage the cell membrane structure. Cisplatin is chemotherapeutics with strongbroad-spectrum anti-cancer activity and widely used for treating many solid tumorsin clinical including ovarian cancer, prostate cancer, testicular cancer, lung cancer,nasopharyngeal cancer, esophageal cancer, thyroid cancer and osteogenic sarcoma and soon, meanwhile side effects are also present, for example, renal toxicity andgastrointestinal tract reactions and also cause ear toxicity, neurotoxicity.Although cisplatin has strong toxicity, for the good therapeutic effect, it is still oneof the most commonly chemotherapy drugs. The anti-tumor activity and side effectsespecially the renal toxicity of cisplatin is in dose-dependent.Acute renal injury is the most serious complication of cisplatin treatment, andadvance into acute renal failure(ARF) finally.It is very important to study thepathogensis of ARF caused by cisplatin for increasing its dose of clinical application toimprove its anti-tumor effect. Cisplatin-induced ARF is related to cytokines, adhesionmolecules and inflammatory cells such as macrophages and neutrophils which infiltratinto renal tissue.Chemokines are an important class of cytokines, play a very important role in thedevelopment of inflammation. In the early stage of inflammation,neutrophils andmonocyte-macrophages recruit to the site of injury under the interaction of CXCchemokins with their receptors. Inflammatory cells release large amounts ofinflammatory mediators in the process of immune response, which also could aggravateinjury. This article aims to present new idea to prevent and reduce the cisplatin-inducedrenal injury by using CXCR1/CXCR2antagonist-G31P. G31P could suppress the hypernomic inflammatory reaction, reduce cisplatin-induced renal injury and preventfurther aggravated.Methods:210femal Kunming mice,16-18g, were randomly divided into sixgroups of DDP, DDP+G31P, sDDP(small dose DDP treated group), G31P, Ca(cancercontrol group), Normal(normal control group).(1) H22tumor mice model: Each ofDDP, DDP+G31P, sDDP, G31P, Ca groups was injected subcutaneously1×106H22cells.(2) Renal injury model: On the seventh day, half an hour before cisplatin injection,the mice of DDP, DDP+G31P group were treated with G31P (500μg/kg; s.c.), the othergroups were treated with isovolumic saline. G31P were injected every other day. Afterhalf an hour, DDP, DDP+G31P group were treated with cisplatin (12.5mg/kg; i.p.), andsDDP group with cisplatin (2mg/kg; i.p.), the other groups were treated with isovolumicsaline.(3) Collection of specimens: After successfully modeling, observed and recordedthe change of mice activity and weight. Sacrificed mice at6h,12h,24h,48h,72h and21d after modeling, we measured the blood serum urea nitrogen (BUN) and creatinine(SCR), weighted both kidneys, calculated the renal coefficient,and quantification ofIL-1, KC and MIP-2mRNA in kidney tissue was done using qPCR. On21th day, thesolid tumor tissues were weighed and detected VEGF-D expression withimmunohistostaining. Finally, inguinal lymph nodes were separated to check whethercancer metastasize using HE staining.Results:(1) Serum BUN and SCR: Serum BUN and SCR was increasing andreached to crest value at48h after injected DDP. Serum BUN and SCR separately8.22mmol/l and58.81μmol/l in DDP+G31P group was significantly lower than DDPgroup10.95mmol/l and67.26μmol/l（p<0.05）, similar with small-dose DDP group.(2) Renal coefficient: After treated with DDP, the renal coefficiensf was rising.The renal coefficiens11.13g/k g of DDP+G31P group was significantly lower than DDPgroup13.54g/kg（p<0.05）. And compared with sDDP group12.02g/kg, there is nodifference.(3)Renal inflammatory factor: The mRNA expression of IL-1β, KC, MIP-2wereincreasing for high-dose DDP induced renal injury. The expression of renalinflammatory in DDP+G31P group decreased significantly（p<0.05）.(4)Tumor weight: High-dose DDP significantly inhibited tumor growth, theweight of tumor was1.01g, which smaller than small-dose DDP treated group1.448gand G31P group1.67g. High-dose DDP combined with G31P was great more effectivefor inhibition of tumor growth, the weight of tumor was0.575g. While G31P could inhibit tumor growth, the tumor was1.67g, which was smaller than the cancer controlgroup2.06g.(5)The expression of tumor tissue VEGF-D and neoplasm metastasis: Comparedwith other groups, the expression of tumor tissue VEGF-D of high-dose DDP group andhigh-dose DDP+G31P group decreased and less tumor cells in inguinal lymph nodes.Conclusion：The increase of serum BUN and SCR, renal coefficient and thequantity of renal inflammatory indicated that high-dose cisplatin injured renal functionof tumor-bearing mice and inflammatory cells were recruited and produced largeamounts of inflammatory mediators during immune response. During renal injuryinduced by DDP, there was a severe secondary or multiple injury which eventuallyleading to severely renal injury. CXCR1/CXCR2antagonist-G31P competitively bindsCXCR1/CXCR2on neutropphils or other inflammatory cells, thus G31P can inhibit thedevelopment of inflammation and reduce the cisplatin-induced nephrotoxicity.Compared with high-dose DDP, high-dose DDP+G31P could inhibit tumor growthmore effectively and decrease nephrotoxicity significantly. In summary, this studyprovides a new idea for rising the dose of cisplatin in clinical, prevention and treatmentof cisplatin-induced renal injury.