Proteomic Study Of Tumor Microenvironment Regulating Malignant Progression Of Tumor Cells P62-PCK2 Plays An Important Role And Dexamethasone Antagonistic Therapy

Background&objective:The relationship between tumor microenvironment(TME)and tumor cell(TC)is very complex and has been the focus of researchers.For advanced tumors,there have been many reports that TME plays a role in promoting malignant progression of TC,but the molecular mechanism of its occurrence is well known,and the target molecules studied are also diverse,but most of them do not come from big data,s screening,there are inevitable limitations.With the rapid development of sequencing technology,the superiority of the new generation of sequencing in oncology research has been highly valued by tumor researchers.The purpose of this paper is to study the important protein molecules and their role of TME in regulating the malignant progression of TC under the guidance of proteomics.Materials and methods:Firstly,human hepatoma cell line HepG2(purchased from Shanghai Chinese Academy of Sciences)and human uveal melanoma cell line 92.1(from the Institute of ear and Eye,University of Pittsburgh,USA)were inoculated in situ and heterotopic in nude mice expressing green fluorescent protein(GFP).(provided by the Experimental Animal Center of Suzhou University,IVC system)HepG2-1,92.1A and 92.1 B were monoclonal from ascites and tumor tissue after tumorigenesisin liver,orbit and brain.Using traditional cell biology methods,it was proved that it was more malignant than its parents' HepG2 and 92.1 in vitro,and then Hangzhou Jingjie Biotechnology Co.,Ltd.was commissioned to make protein chips,and then GO,KEGG and interaction network mapping were used.P62 and PCK2 were selected from 19 common differential proteins as target proteins for further study,and their functions were verified in vitro and in tumor-bearing mice.the therapeutic experiments were carried out with dexamethasone(DEX)and lovastatin.Results and analysis:The results of Werstem Blot showed that the expression of P62 and PCK2 upregulated and downregulated by 1.505 and 0.597,respectively,compared with the parent TC,which was consistent with the data provided by the protein chip database.The results showed that the two proteins were opposite to each other and played a positive and negative regulatory role.P62siRNA and lovastatin were then used to target the target cells in vitro and dexamethasone(DEX)in vitro and in vivo.As a result,in addition to the reversal of the target protein expression(such as the downregulate of P62 expression and the upregulate of PCK2 expression),the malignant phenotype of TC is inhibited.The antitumor effect of lovastatin could also be improved by dexamethasone.In particular,the effect of DEX is to inhibit the aerobic glycolysis of TC by up-regulating PCK2,and at the same time,the proliferation of TC is inhibited.Compared with the control group,the role of DEX in tumor-bearing mice not only reduced the tumor weight,but also inhibited a large number of inflammatory cells infiltrating into TME,and was consistent with the decrease of tumor tissue necrosis.Conclusion and prospect:For the first time,proteomics research method was used to optimize and confirm the positive and negative regulation of P62 and PCK2 on the malignant progression of hepatoma and melanoma cells induced by TME,respectively.The higher the expression of P62 in the clinical tissue specimens of TCGA database,the worse the prognosis of the patients,while the higher the expression of PCK2,the better the prognosis.The antitumor effect of lovastatin can be improved by dexamethasone,which provides a basis for further synchronous in vivo treatment of both TME and TC.The main purpose of DEX in anticancer treatment is to control inflammatory reactive edema,only as a temporary rescue measure.Although it has been reported that the inhibitory effect of DEX on TC is achieved by inhibiting glucose metabolism,it is not advocated for sustained use because of its inhibitory effect on innate immune response.Only the author(Yuantao Wu,Cancer Management and Res 2019)recently reported for the first time that the role of DEX in breast cancer and liver cancer models in mice with normal iumune function is not only to inhibit the proliferation of TC,but also to regulate the upregulate of the proportion of CD4+T cells and CD8+T cells in positive immune cells.The downregulate of the proportion of Treg and MDSC in negative immune cells indicates that DEX still has anti-tumor effect in normal tumor-bearing mice,which provides a basis for combining DEX into a new anticancer regimen in the future.