The Imbalance In The Complement System And Its Possible Physiological Mechanisms In Patients With Lung Cancer

Background: Lung Cancer is one of the most malignant tumors with the highest morbidity and mortality in the world,and it is a serious threat to human health.As a functional bridge between innate and adaptive immune responses,complement system plays critical roles in tumorigenesis.It inhibits tumorigenesis on the one hand by promoting acute inflammation and tumor cell lysis,but on the other hand promotes tumor growth by stimulating chronic inflammation and immunosuppression.Consistent with the conflicting effects of the complement system in tumor formation,the plasma concentration of complement protein is significantly different from that in lung cancer patients.In recent years,many studies have been conducted on complement and cancer(including lung cancer).However,few prospective epidemiological studies have investigated the imbalanced complement system and its possible physiological mechanisms in lung cancer patients.Therefore,we integrated data available in the database to compare complement and complement-associated expression profiles from lung cancer patients(involved in the complement cascade by direct interaction with complement proteins).Then,we assessed their level in lung cancer tissue through biological techniques such as i TRAQ proteomics.Finally,we can study the possible physiological mechanisms of the imbalanced complement system in patients through cell co-culture,in order to provide an important theoretical basis for the diagnosis,treatment and prognosis of patients with clinical lung cancer.Objective: Using public database data to determine the imbalance of the complement system in lung adenocarcinoma;tissue samples from patients with clinical lung cancer use i TRAQ proteomics to detect the expression levels of C3,C9 and other complement protein components in tissues;In vitro,QSG7701 was co-cultured with LTP-?-2,NCI-H1703,and A549,respectively,to explore the effect of lung cancer cells on the synthesis of complement protein in normal hepatocytes;The supernatant after co-culture was collected to further investigate whether hepatocyte synthesis and secretion of complement protein components are positively correlated to explore the potential physiological mechanisms of the lung adenocarcinoma complement system.Methods: 1.We obtained proteomics data and transcriptomics data from public databases,screened for differentially expressed complement genes,and then extracted expression values for complement levels in related publications,and calculated median,mean,and standard deviation.2.The tissues of twenty clinical patients with primary lung cancer and the adjacent tissues were collected and homogenized for sample preparation and protein extraction.The company used i TRAQ proteomics to analyze 20 pairs of complement protein components in primary lung cancer tissues and adjacent tissues.Comprehensive bioinformatics data and proteomics data were used to screen out ten key complement components.The lung cancer tissues and adjacent tissues of two clinical patients were further verified by RT-q PCR and Western-blot.3.Normal hepatocytes QSG-7701 were co-cultured with A549,LTP-?-2,and NCI-H1703,respectively.After 24 hours and 48 hours,we got the m RNAs and proteins from the lower QSG-7701 cells.The RT-q PCR and Western-blot method were used to detect the m RNA and protein expression levels of complement.Then,co-culture was carried out by using QSG-7701,A549 and HBE,we got the co-culture supernatant after 24 hours and which were detected with Western-blot for the expression level of the complement protein component.Results: 1.We analyzed the proteogenomic profiles of complement and complement-related components,identified the differential expressions of 39 complement and 24 complement-related proteins.Microarray-based datasets identified 33 complement and 17 complement-related components with decreased m RNA levels in lung cancer tissues.In accordance with the decreased m RNA levels,the protein levels of 27 complement and 16 complement-related components were also reduced in lung cancer tissue.Conversely,the levels of 33 complement and complement-related proteins were increased in serum of lung cancer patients.2.With i TRAQ proteomic methods,we detected 31 decreased and 2 increased complement and complement-related proteins in lung adenocarcinoma tissues compared to its adjacent normal lung tissues.The decreased levels of 10 components(C3,C4,C5,C4 BPA,C4BPB,C6,C7,C9,CFH and CFI)in lung cancer tissues were further confirmed by q RT-PCR and western blotting.3.Co-culture results showed that in addition to the slightly reduced level of C4 BPB m RNA,in QSG-7701 co-cultured with lung cancer cells,other complement components were significantly elevated in m RNA and protein levels.The level of complement protein in the co-culture supernatant of QSG-7701 and A549 cells was compared with QSG-7701 and HBE.Consistent with the increased synthesis of complement protein in co-cultured QSG-7701 hepatocytes,complement protein secretion was also increased in co-culture supernatants of QSG-7701 and A549 when compared to controls.Conclusion: 1.The prevalence of an imbalanced complement system accompanied with the physiological disturbances of lung cancer patients and Equilibrium is nothing but a temporary,relative,unity of opposites.The decreased complement levels in lung cancer tissues could cause the depression of complement-dependent immune and immune escape of cancer cells.2.As an organic whole,the coupled conflict roles of complement immunity in cancer tissues and serum of patients may runs through the growth of lung cancer in patients.