OBJECTIVETo investigate the expression of platelet derived growth factor-BB (PDGF-BB) and microvessel density (MVD) marked with CD34 in clear cell renal cell carcinoma (CCRCC) and explore their relevance to clinicopathologic features and prognoses of patients.

METHODSExpressions of PDGF-BB and CD34 in the tissue samples of 100 clear cell renal cell carcinomas were detected by immunohistochemical (IHC) SP staining. The microvessel density (MVD) was counted using Weidner's method. For PDGF-BB assessment, the staining intensity and the proportion of positive tumor cells were analyzed. Staining was considered immunoreactive when brown granules were identified in the cytoplasm or nuclei of tumor cells. Staining intensity and the proportion of positively stained tumor cells in lesions was scored for further analysis. Statistical analysis was performed using the software SPSS 18.0.

RESULTSThe MVD value marked by CD34 in the 100 cancer tissues was (105.49 ± 37.95) profiles/HPF. The median value of MVD in the entire cohort was used as the cut-off point for low MVD group (42 cases) and high MVD group (58 cases). The MVD of the low and high MVD groups was (75.12 ± 22.41) profiles/ HPF and (135.86 ± 22.91) profiles/HPF, respectively, with a statistically significant difference (P < 0.001). MVD was significantly correlated with the tumor T staging, histopathological grading and postoperative metastasis in CCRCC (P < 0.05, respectively). Among the 100 CCRCC cases, there were 38 cases with low PDGF-BB expression and 62 cases with high PDGF-BB expression, and the expression of PDGF-BB was significantly correlated with tumor diameter, T staging, histopathological grading and postoperative metastasis in the CCRCC (P < 0.05, respectively). Kaplan-Meier survival analysis showed that the cancer specific survival (CSS) in CCRCC patients with high expression of MVD and PDGF-BB was significantly better than that in the group with low MVD and low PDGF-BB expression (P < 0.001, respectively). Expression of PDGF-BB protein was positively associated with the MVD assessed by Spearman's correlation and factor analysis (r = 0.461, P < 0.001).

CONCLUSIONSignificantly increased MVD and PDGF-BB expression detected in CCRCC patients indicate a better tumor grading and staging, and a longer survival time.

Antigens, CD34 ; metabolism ; Carcinoma, Renal Cell ; blood supply ; metabolism ; pathology ; Female ; Follow-Up Studies ; Humans ; Kidney Neoplasms ; blood supply ; metabolism ; pathology ; Male ; Microvessels ; metabolism ; pathology ; Middle Aged ; Neoplasm Grading ; Neoplasm Metastasis ; Neoplasm Staging ; Proto-Oncogene Proteins c-sis ; metabolism ; Treatment Outcome

OBJECTIVETo study the effect of platelet derived growth factor-B and its receptor expression on the proliferation of renal cell carcinoma ACHN cells in vitro and in vivo.

METHODSPDGF-B gene was transfected into human renal carcinoma cell line ACHN cells, and the proliferation capability of ACHN cells transfected with or without PDGF-B was assessed by MTT assay. The effect of PDGF-B on the expression of p-PDGFR-β in endothelial cells and vascular smooth muscle cells (VSMC) was detected by Western blot. ACHN cells transfected with PDGF-B were injected into mice (untransfected ACHN as control) to induce tumor formation. Immunohistochemical staining was used to detect the expression of Ki-67 in tumor cells and the tumor volume was measured to compare the tumor growth in the two groups.

RESULTSThe PDGF-B expression of ACHN cells in transfected group was significantly increased than that in the untransfected group. MTT assay showed that the proliferation capability of ACHN cells in the transfected and untransfected groups had no significant differences at different time points (P>0.05). The expression of p-PDGFR-β in VSMC was significantly increased when cultured with PDGF-B overexpression culture medium. The mean tumor size of the PDGF-B group and control group was (0.305±0.108) cm(3) and (0.577±0.218) cm(3), respectively (P=0.007). Ki-67-positive tumor cells were (41.00±5.34)/HPF in the PDGF-B-transfected group and (55.80±2.95)/HPF in the untransfected group (P=0.001).

CONCLUSIONPDGF-B overexpression may up-regulate p-PDGFR-β expression of VSMC in renal cell carcinoma, and inhibit the tumor cell proliferation and tumor growth through paracrine signaling.

Animals ; Carcinoma, Renal Cell ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Kidney Neoplasms ; metabolism ; pathology ; Mice ; Proto-Oncogene Proteins c-sis ; Receptor, Platelet-Derived Growth Factor beta ; genetics ; metabolism