| BackgroundRenal cell carcinoma(RCC),or simply "kidney cancer" for short,is a malignant carcinomaoriginating from urinary tubule epithelium in renal parenchyma.It accounts for 2%-3%of adult malignancies and 80%-90%of all renal malignancies.Due to the popularization of health checkups and the application of imaging techniques such as ultrasound and CT,the proportion of localized renal cancer in kidney cancer patients has exceeded 50%.Patients with the typical renal cancer triad including clinical manifestations of hematuria,pain and mass only accounts for 6%-10%of all RCC patients,but these patients are usually at an advanced stage when they seek medical treatment,and the prognosis is poor.The etiology and pathogenesis of kidney cancer are still not completely clear,but the occurrence and development of RCC are closely related to the function of the human immune system.Among them,cellular immunity mediated by CD4+helper T cell(helper T cell,Th cell)plays an important role in the occurrence of RCC.Th22 cells are a new type of CD4+helper T cell subset that has attracted more attention in recent years.Th22 cells secrete IL-22 and TNF-α.The receptors expressed by Th22 cells include chemokine receptor 6(CCR6),CCR4,and CCR10.CCR6+CCR4+CCR10+is the phenotypic characteristic of Th22 cells.The key transcriptional regulator for differentiation is the aryl hydrocarbon receptor(AHR),but Th22 cells cannot express or only lowly express the transcription factor of Th17 and Th1 cells,namely retinoic acid related orphan receptor-c(RORC)and T-bet.With the assistance of IL-6,TNF-α and other cytokines,and under the regulation of RORC,the initial CD4+T lymphocytes expresse specific transcription factor AHR and differentiate into Th22 cell phenotypes,then produce effector factors IL-22,and finally differentiate into Th22 cells.The main cytokine synthesized and secreted by Th22 cells is IL-22,which belongs to the IL-10 cytokine family.The related functions of Th22 cells are also mainly realized through the action of IL-22.By participating in regulating the biological properties of epithelial cells,IL-22 plays a particularly important role in many autoimmune diseases as systemic lupus erythematosus,psoriasis,rheumatoid arthritis,and certain infectious diseases or tumors.Further,the difference of its effect is closely related to the microenvironment.Th17 cells are also one of the newer helper T cell subsets,which mainly secrete cytokine IL-17,but can also secrete IL-22 and other cytokines in a small amount.In recent years,many studies have conducted in-depth discussions on the differentiation and regulation mechanisms of Th17 cells.It has been confirmed that Th17 cells can exert specific immunoregulatory effects under the cooperation of other immune cells.Increased function or expression of related cytokines may cause serious immune-related diseases or malignant tumors.Studies have suggested that the occurrence of a variety of malignant tumors,including gastric cancer,liver cancer,colorectal cancer,leukemia,etc.,is related to the increase in the proportion or function of Th17 cells.In addition,the increased expression of Th17 cells in the peripheral blood of RCC patients may promote the local progression and distant metastasis of the tumor.However,the mechanism of Th17 cells in the occurrence and development of RCC is not yet fully understood,and it is necessary to do further research.Th1 cells are a subset of CD4+T cells discovered earlier and are involved in the differentiation and immune regulation of many tumors.Th1 cells mainly secrete interferon-γ(IFN-γ)and IL-2,thereby activating CD8+lymphocytes and natural killer cells.It has been proven to inhibit tumor growth in a variety of tumors.Studies have shown that the decrease in the number of Th1 cells in the peripheral blood of patients with kidney cancer will weaken the body’s anti-tumor function,promote the immune escape of tumor cells in the body,and accelerate the progression of kidney cancer.The newly discovered helper T lymphocyte subsets and their special role in cellular immunity have opened up new research directions for the pathogenesis and treatment of tumors.In recent years,the research on the role of Th22 cells and their effector cytokines in certain autoimmune diseases and some tumors such as lung cancer,hepatocellular carcinoma,colorectal cancer,and gastric cancer has received continuous attention.However,there are not many studies on Th22 cells differentiation,regulation and its relationship with tumor progression in the tumor microenvironment.Further,the relative conclusions are still not uniform.So far,there is no relevant research on the expression changes of Th22 cells in the peripheral blood of RCC patients.Therefore,it is necessary to do further research on Th22 cells in renal cell carcinoma,so as to clarify the differentiation of Th22 subsets in the peripheral blood of renal cell carcinoma and explore the status of Th22 cell subset in the pathogenesis process of RCC patients.In view of the role of Th17 and Th1 cells in tumor immunity and the internal connection between Th17、Th1 and Th22 cells in the differentiation process,it is necessary to explore the possible role of the three types of cells in the pathogenesis of RCC by studing the expression changes of Th17、Th1 cells and their relationship with Th22 cells in RCC patients.Objectives1.Clarify the expression level of Th22 subsets and the possible mechanism of action in the peripheral blood of RCC patients.2.Analyze the level of the functional cytokine IL-22 of Th22 cells in the plasma of RCC patients,and explore the role of Th22 cells in the pathogenesis of RCC.3.Detect the ratio of Th17 and Th1 cells in the peripheral blood of RCC patients and analyze the correlation between Th17、Th1、and Th22 cells.4.Study the relative quantitative expression of the transcription factor AHR for Th22 cell differentiation and the transcription factor RORC mRNA for Th17 cell differentiation,and explore the potential biological mechanism of Th22 and Th17 cells in RCC.Materials and Methods1.Thirty-two newly diagnosed RCC patients were selected and thirty healthy volunteers as the normal control group.2.Flow cytometry was used to detect the frequency of Th22,Th1 and Th17 cells in the total CD3+CD8-lymphocytes in RCC patients and healthy controls’ peripheral blood.3.Enzyme-linked immunoadsorbent assay(ELISA)was used to detect the level of IL-22 cytokine in the plasma of RCC patients and healthy controls.4.Real-time fluorescent quantitative reverse transcription polymerase chain reaction(RT-PCR)technology was applied to detect expression status of the key transcription factor AHR required for Th22 cell differentiation,and the key transcription factor required for Th17 cell differentiation RORC mRNA expression.5.Statistical analysis:Data are expressed as mean±standard error(mean±SEM)or median(range).The comparison between the two groups was analyzed by Wilcoxon rank sum test.In correlation analysis,Spearman correlation test was used for non-normally distributed data,and Pearson correlation test was used for normally distributed data.GraphPad Prism 6.0 software(from GraphPad,San Diego,CA,United States)and SPSS 17.0 software(from SPSS,Inc.,Chicago,IL,USA)software was used for statistical analysis.P<0.05 was considered as statistically significancy.Results1.The level of Th22 subsets in peripheral blood of RCC patients(1.97 ± 0.32%)was significantly higher than that of healthy controls(0.75±0.05%;P<0.001).2.The level of IL-22 cytokine(27.38±0.75 pg/ml)in the peripheral blood of RCC patients was significantly higher than that in the healthy control group(20.06± 0.54 pg/ml;P<0.0001).3.There was a positive correlation between Th22 cells and IL-22 levels in the peripheral blood of RCC patients(r=0.4277,P<0.05),but no correlation was found in the healthy control group,(r=-0.1361,P=0.4734).4.The level of Th17 cells in peripheral blood of RCC patients(3.18 ± 0.40%)was significantly higher than that of healthy controls(1.27±0.13%,P<0.001).5.Th22 and Th17 cells showed a positive correlation in the peripheral blood of RCC patients(r=0.4816,P<0.01),but no correlation was found in healthy controls peripheral blood(r=-0.1311,P=0.4900).Also no correlation between Th22 and Th1 cells in RCC patients(r=0.1644,P=0.3686)and healthy controls(r=0.0247,P=0.8967)was found.6.The relative quantitative expression of AHR mRNA in RCC patients(0.47 ±0.07%)was significantly higher than that in healthy controls(0.23 ± 0.05%,P<0.05).The expression level of RORC mRNA in RCC patients(0.38±0.06%)was also significantly higher than that of healthy controls(0.18±0.03%,P<0.05).Conclusions1.There is a abnormally high expression of Th22 cell subset and its functional cytokine IL-22 in peripheral blood of RCC patients.2.Th17 cells are abnormally expressed in RCC,and have a certain coordination effect with Th22 cells.3.Th22 cells may play a certain role in the pathogenesis of RCC through its functional cytokine IL-22 under the action of AHR.RORC plays a key role in the differentiation of Th17 cells in the peripheral blood of RCC patients,and regulates the differentiation of Th22 cells in RCC.4.The abnormal expression of Th22 and Th17 cells in the peripheral blood and IL-22 in the plasma of RCC patients may play a role in the pathogenesis of RCC.The in-depth discussion of the specific mechanism of Th22 and Th17 cells in the pathogenesis of RCC may hopefully provide a new idea for the treatment of RCC.BackgroundRCC is one of the most common urinary tract tumors.The incidence of kidney cancer in our country is increasing rapidly,and it is second only to bladder cancer,ranking second in urinary system tumors.However,about 30%of kidney cancer patients present with local or distant metastases at the time of diagnosis.Kidney cancer is not sensitive to chemotherapy drugs.The objective response rate of traditional cytokine IFN-α or IL-2 treatment is only 5-27%,and the median progression-free survival is only 3-5 months.So the most patients are unable to obtain satisfactory curative effect.In recent years,targeted drugs such as sorafenib and sunitinib have achieved certain effects in the treatment of RCC,but there are also unresolved problems such as drug resistance and serious adverse reactions.Thus,the long-term survival rate of advanced kidney cancer is low and the prognosis is poor.As the current assessment of renal cancer metastasis and clinical progress mainly relies on imaging examinations such as CT or MRI,the progress and prognosis of the tumor cannot be judged as soon as possible.Therefore,the discovery of meaningful clinical detection indicators has important clinical significance for the early diagnosis and progress of kidney cancer.CD4+ T cells and their secreted cytokines play a very important role in tumor immune regulation,differentiation,and tumor progression.Th17 and Th22 cells are two newly discovered Th cells in recent years.Recent studies have shown that Th22 and Th17 cells are related to the occurrence and development of a variety of autoimmune diseases and tumors.In particular,Th22 cells have received more attention due to their unique cell phenotype and biological characteristics.Our previous studies have shown that the related cellular immune abnormalities involved in Th22 and Th17 cells may play a role in the pathogenesis of RCC,but the value of the role of Th22 and Th17 cells in the progression and prognosis of RCC still needs to be further clarified.We judged the staging and grading of RCC patients included in this study based on the 2017 American Joint Committee on Cancer(AJCC)renal cancer TNM staging and staging combination standards and the 2016 WHO/International Society of Urological Pathology(ISUP)nuclear grading standards.The RCC patients are grouped according to different stages and grades.The differences in Th22,Th17,Th1 cells and plasma IL-22 levels between the groups are analyzed to futher explore the relationship between Th22,Th17,Th1 cells and the clinical progress of RCC.We also used the Kaplan-Meier survival curve to analyze the impact of Th22,Th17,and Th1 cells on the overall survival of RCC patients,and explored the prognostic value of these cells in RCC.Objectives1.Clarify the changes in the expression levels of Th22,Th17,and Th1 cell subsets in the peripheral blood of RCC patients with different clinical stages and pathological grades.2.Analyze the correlation between the proportion of Th22,Th17,and Th1 cells in peripheral blood of RCC patients and the stage and histological grade of renal cancer.3.Study the clinical value of Th22,Th17,and Th1 cell subsets on the overall survival of RCC patients.4.Evaluate the value of Th22 and Th17 cells as tumor markers in the clinical progress and prognosis of RCC.Materials and Methods1.The results of flow cytometry analysis of Th22,Th17,and Th1 cells of the 32 RCC patients in the first part of the study were collected and the ELISA test results of IL-22 were also collected.2.The staging and grading of RCC patients included in this study were judged based on the 2017 American Joint Committee on Cancer(AJCC)renal cancer TNM staging and staging combination standards and the 2016 WHO/International Society of Urological Pathology(ISUP)nuclear grading standards.Analyze the detection results of Th22,Th17,Th1 cells,and plasma IL-22 with the corresponding clinicopathological stages and histological grades of RCC patients to observe the Th22,Th17,Th1 cells and plasma IL-22 of RCC patients with different stages and grades.The relationship between these cells and the occurrence and development of RCC was also analyzed.3.Analyze the overall correlation between Th22,Th17,Th1 cells,and plasma IL-22 levels with RCC pathological stage and nuclear grade.4.The Kaplan-Meier survival curve was used to analyze the differences in overall survival among RCC patients with different expression levels of Th22,Th17 and Th1 cells,and to explore the prognostic value of Th22,Th17 and Th1 cells for RCC patients.5.Statistical analysis:Spearman correlation test was used for non-normally distributed data.Pearson correlation test was used for normally distributed data.The Kaplan-Meier method was used to analyze the cumulative survival time,and the log-rank test was used to compare the differences between groups.All statistical analysis used GraphPad Prism 6.0 software(GraphPad,San Diego,CA,United States)and SPSS 17.0(SPSS,Inc.,Chicago,IL,USA)software.P<0.05 was considered statistically significant.Results1.RCC patients with stage Ⅲ、Ⅳ had a significantly higher percentage of circulating Th22 cells than patients with stage Ⅰ、Ⅱ(2.70± 0.61%vs.1.34±0.22%,P<0.05).Furthermore,the IL-22 concentration in stage Ⅲ、Ⅳ patients was significantly elevated compared to patients in stage Ⅰ、Ⅱ(30.02±0.94 pg/mL vs.25.06±0.81,P<0.01).RCC patients with stage Ⅲ、Ⅳ also had a significantly higher percentage of circulating Th17 cells than patients with stage Ⅰ、Ⅱ(4.07±0.68%vs.2.40±0.40%,P<0.05).No significant difference was found between the percentage of Thl cells and tumor stage(18.95±1.65%vs.17.31±1.71%,P=0.4933).2.RCC patients with grade Ⅲ、Ⅳ had a significantly higher percentage of circulating Th22 cells than patients with grade Ⅰ、Ⅱ(3.17 ± 0.84%vs.1.42± 0.20%,P<0.05).The IL-22 concentration in grade Ⅲ、Ⅳ patients was significantly elevated compared to patients with grade Ⅰ、Ⅱ(29.90± 1.17 pg/mL vs.26.24 ±0.86,P<0.05).RCC patients with grade Ⅲ、Ⅳ also had a significantly higher percentage of circulating Th17 cells than patients with grade Ⅰ、Ⅱ(4.66 ± 0.90%vs.2.51 ± 0.36%,P<0.05).Nevertheless,there was no significant difference between the percentage of Th1 cells and tumor grade(18.98 ± 2.16%vs.17.62± 1.43%,P=0.6004).3.A positive correlation was found between Th22 cells and tumor stage or grade in RCC patients(r=0.6114,P<0.01;r=0.3865,P<0.05).Meanwhile,there was also a positive correlation between Th17 cells and tumor stage or grade in RCC patients(r=0.4861,P<0.01;r=0.4646,P<0.01).Nevertheless,there was no significant correlation between Thl cells and tumor stage or grade in RCC patients(r=0.3003,P=0.0949;r=0.1265,P=0.4904).4.Compared with patients with low Th22 cell percentage(<1.9%,mean),RCC patients with high Th22 cell percentage(≥1.9%,mean)have a lower 24-month survival rate curve,though this difference was not statistically significant.When comparing RCC patients with high Th17 cell percentage(≥3.1%,mean)and low Th17 cell percentage(<3.1%,mean),a similar survival rate trend was obtained.However,no similar survival trend was found between RCC patients with high Th1 cell percentage(≥18.0%,mean)and low Th1 cell percentage(<18.0%,mean).Conclusions1.The abnormal expression of Th22,Th17 cells and the cytokine IL-22 in the peripheral blood of RCC patients may promote the clinical progress of RCC.2.The levels of Th22,Th17 cells and cytokine IL-22 in the peripheral blood of RCC patients may be related to the malignancy of RCC.3.Detecting the expression levels of Th22 cells and their cytokine IL-22 in the peripheral blood of RCC patients is promising for judging the malignant progression and prognosis.Further studies on the mechanism of Th22 cells in RCC may provide references for early implementation of individualized treatments for RCC patients. |
PDF Full Text Request