The Research Of The Expression Of VEGF-C And VEGFR-3in Renal Cell Carcinoma And The Relationship With Lymph Node Metastasis

Objective:To investigate the function and its significance of VEGF-C/VEGFR-3system in the renal cell carcinoma(RCC),The relationship between itsexpression levels with1ymphatic vessel density(LVD) and lymph nodemetastasis have also been investigate. To further clarify the mechanism ofRCC lymphangiogenesis and its relationship with RCC biology behavior,provide new targets for RCC targeted therapy.Methods:Collected in July2012to September2013from renal cell carcinoma(RCC)40cases surgical removal of the specimen,all are single,preoperativeroutine urinary tract ultrasound,CT or MRI,18cases of them reserves thenephron sparing surgery,and22cases underwent radical nephrectomy,and thepatients with lymph node metastasis were radical nephrectomy with regionallymph node cleaning technique.In patients with male25cases,female15cases.With an average age of51.9years (24~65years old).Specimens wereconfirmed by pathology for RCC,Clear cell carcinoma of the37cases,papillary adenocarcinoma in2cases,color cell carcinoma in1case,preoperative did not receive radiation and chemotherapy andimmunotherapy.10cases of renal tissue that from the tumor edge more than5cm as controls.Surgical resection specimens were divided into two,one ofthem stored in the refrigerator minus80degrees;and another one with4%paraformaldehyde fixed, conventional paraffin embedding, set aside.Staging in1997, the WHO standards:20cases of high differentiation,11cases ofmoderately differentiated,9cases of poorly differentiated or undifferentiated.Tumor stage in2002AJCC kidney cancer clinical stage:Ⅰperiod in22cases,Ⅱ period in6cases, Ⅲ period in11cases, Ⅳperiod in1case.29cases without lymph node metastasis,there are11cases with the renalhilum lymph node metastasis.Then the levels of expression of vascularendothelial growth factor-c(VEGF-C)by RT-PCR and its correlation with LVDand lymph node metastasis were assessed in40samples of RCC and10normal renal tissues.In40samples of RCC,the lymphatic vesselsimmunostained with monoclonal antibodies against vascular endothelialgrowth factor receptor-3(VEGFR-3)and LVD were evaluated in both intra-andperi-tumoral areas.We used SPSS17.0statistical software,the comparisonbetween groups using t test, and chi-square test, rank data using rank andinspection,P<0.05for the difference was statistically significant.Results:1. The express of VEGF-C mRNAThrough the RT-PCR analysis,the expression of VEGF-C mRNA in10cases of normal renal tissue are a small,the relative expression level was0.250±0.104.The expression level of VEGF-C mRNA in40casesof RCC tissue was0.576±0.191(P<0.001).With lymph nodemetastasis group and without lymph node metastasis group VEGF-CmRNA relative expression levels were0.693±0.174and0.532±0.181,Therewas a significance different of VEGF-C mRNA between lymph nodemetastasis and without lymph node metastasis group(P<0.05).The expressionVEGF-C mRNA has no relationship with age, gender, pathologicalclassification,but closely related to clinical stages and lymph node metastasis(P<0.05).2. The express of VEGF-C in normal renal tissues and RCCThe positive rate of VEGF-C in the normal renal tissue group(30.0%)wassignificantly lower than that in the RCC(85.0%,p<0.01).The positive rate ofVEGF-C in the lymph node metastasis group was significantly higher thanthat in the without lymph node metastasis group(p<0.05) and there was nodifference between the well differentiated group and the poor differentiated group(p>0.05). The positive expression of VEGF-C in RCC had relations withtumor stage(p<0.05).3. The LVD of intra-and peri-tumoral areas and its relationship withtumor lymph node metastasisImmunohistochemical results show positive VEGFR-3protein stainingmainly in lymphatic vessel endothelial cell cytoplasm and (or) coated,Presenta tan.Visible within the tumor lymphatic vessel is small,meanwhile around thetumor lymphatic vessels in functional expansion,and has the expansionpipe.At the same time, some tiny capillaries (with RBC)and malpighian tubeskin cells have brown staining,This Prompt that VEGFR-3not only express inlymphatic endothelial cells of RCC,also express in the tiny capillaries andmalpighian tube skin cells.The LVD of peri-tumoral areas is14.16±2.58,higher than thatintra-tumoral areas of9.74±2.48and10.27±2.92of normal renal tissues,thedifference was statistically significant (P<0.01).There was no statisticallysignificant difference between LVD in tumor and normal renal tissues.Westudied11cases of RCC for lymph node metastases,the LVD of intra-andperi-tumoral areas are12.01±2.14and2.14±1.86,Significantly higher than that withoutlymph node metastasis group8.88±2.03and2.03±2.03(P<0.01).Conclusions:Compared with controls,RCC specimens had higher mRNA expressionlevels of VEGF-C（P<0.001).VEGF-C mRNA expression in lymph nodemetastasis group is higher than without lymph node metastasis.Ⅲ and Ⅳstage RCC had higher mRNA expression of VEGF-C compared with ⅠandⅡ stage.The positive rate of VEGF-C in the normal renal tissue group wassignificantly lower than that in the RCC group.The positive rate of VEGF-Cin the lymph node metastasis group was significantly higher than that in thewithout lymph node metastasis group.The VEGF-C in RCC, such astranscription and translation level is to ascend.By immunohistochemicalstaining VEGFR-3we know that pre-tumor existing functional expansionlymphatic,by statistical analysis,LVD was higher in peri-tumoral areas thanthe central tumor and normal tissue,and that lymphatic infiltration also increased significantly.It is suggested that in RCC,VEGF-C/VEGFR-3pathway can contribute to lymphangiogenesis in peri-tumor,lymphaticinvasion of tumor and lymph node metastasis.It is plays an important role incarcinogenesis and development of RCC.