The Extracellular Release Of DAMPs By Tumor Cells Affected Tumor Biological Behaviours

Development of an invasive cancer was not simply a result of the geneticchanges in the tumor cells but also the result of genetic and epigenetic changes withinthe host.Host cells,including inflammatory cells,endothelial cells,and fibroblasts,ware recruited and activated in the microenvironment of transformed cells.The tumormicroenvironment was characterized by both secreted and released factors from thetumor cells,associated with qualitative differences in the infiltrating leukocytes,recruited stem cells,and promotion of reparative angiogenesis and stromagenesis.Thedevelopment of a tumor over many years typically lead to reciprocal alternations inthe host and the tumor,enabling tumor growth.We had hypothesized that chronicunscheduled tumor cell death(necrosis)resulted in the release of DAMPs into thetumor microenvironment and systemic circulation.These DAMPs,best exemplifiedby the molecule HMGB1,lead to subsequent activation of innate immune effectorsand establishment of a chronic inflammatory state that favored tumor progression,growth,and metastasis.What DAMPs are had been a matter of conjecture for a decade,but severalpromising candidates had been revealed in the last few years:(i)the nuclear proteinHMGB1;(ii)the S100 family of molecules;(iii)the purinergic metabolites ATP,adenosine monophosphate,adenosine,and uric acid;and(iv)heat shock proteins.These factors were usually found in the cytosol and,when released into theextracellular space,resulted in significant host responses,acting on specializedreceptors including TLR-2,TLR-4,and RAGE.Besides these molecules,RNA andDNA-neucleoprotein complex were likely released.It had been proved that DAMPs could recruit inflammatory cells,which promoted wound healing.Toll-like receptors(TLRs),which recognized a variety ofDAMPs were centrally involved in the initiation of the innate and adaptive immuneresponses.However,recent evidence showed that functional TLRs were alsoexpressed on a wide variety of tumors suggesting that tumor cell TLR signaling maybe directly and continually activated by DAMPs.Our experiment is aim to reveal howDAMPs affect tumor progression in vivo and in vitro.This experiments weresubdivided into four parts.Partâ… Regulatory Effect and Mechanism of Recombinant HSP70 on tumorbiological behaviours.We incubated tumor cells with recombinant HSP70 in vitro.HSP70 could enhance the proliferation of tumor cells in vitro,and lead to resistance toapoptosis,but had little effect on the invasion ability.The downstream signalingmolecules of the TLRs signal pathway was activated dramatically.Nevertheless,theactivity of MMPs was unregulated by HSP70.Partâ…¡Regulatory Effect and Mechanism of Freeze-thawing Supernatant ofTumor Cells on Tumor Biological Behaviours.The mixture was prepared from tumorcells by freezing-thawing cells.We found that freeze-thawing supernatant couldenhance the proliferation of tumor cells in vitro,and facilitated the invasion ability oftumor cells dramatically.The downstream signaling molecules of the TLRs signalpathway was activated,too.Partâ…¢Promoting Effect of Freeze-thawing Supernatant on H22 Tumor Growthand Apoptosis-resistance.It was observed that the interaction of freeze-thawingsupernatant with H22 cells could promote tumor growth in vivo.Besides,thefreeze-thawing supernatant could promote the proliferation of H22 cells and lead toresistance to apoptosis in vitro.Partâ…£HSP70 Interact with HMGB-1 in Tumor Progression.This experimentwas aim to investigate the relationship of HSP70 and HMGB-1 in DAMPs and thelikely mechanism.Activation of TLR4 ligands of LPS and HSP70 of tumor cellsinduced HMGB-1 releasing.Besides these,freeze-thawing supernatant had the sameeffect.Interestedly,LPS and freeze-thawing supernatant could also stimulate theexpression of HSP70 in tumor cells and enhanced the releasing of HSP70 by tumorcells.