Expression Of CD44V6 And Nm23-H1 Protein, DNA Ploidy Analysis In Renal Cell Carcinoma And Its Clinical Significance

Objective: CD44 belongs to adhesion molecule family; it is a polymorphic family of widely distributed transmembrane glycoproteins that play an important role in lymphocyte homing, lymphocyte activation, cell-cell adhesion or cell-matrix interaction and tumor metastasis. Studies to date have shown that expression of CD44 and its variant isoforms is associated with aggressive behavior in various tumors, Especially CD44V6 has a role in tumor progression and development in various tumours. nm23 is a candidate tumor suppressor gene; nm23-H1 may play an important role in tumor metastasis. The mechanism in carcinogenesis of renal cell carcinoma (RCC) is undetermined. The study of the expression of CD44V6 and nm23-H1 protein in RCC is an important way to reveal the mechanism of RCC. Expression of CD44V6 and nm23-H1 in RCC were mostly detected by immunohistochemistry and reverse-transcription polymerase chain reaction (RT-PCR). In this study, the expression of CD44V6, nm23-H1 protein and DNA ploidy in RCC tisssues were detected by flow cytometry (FCM) to study their relations and the relation to the development and the biological characteristics of RCC. Methods: Fresh samples of 35 renal cell carcinoma and 35 corresponding paratumor tissues were obtained from 35 patients (27 men and 8 women, mean age 55.4 years, range from 33 to 79 years) with RCC who underwent radical nephrectomy at the Forth Hospital of Hebei Medical Univercity between 2002 and 2003. Meanwhile 5 normal renal tissues were used as control. Cell type of RCC: clear cell type 24 cases, granular cell type 3 cases, mixed-cell type 5 cases, sarcomatoid type 3 cases. According to Robson staging : stage Ⅰ 4 cases, stage Ⅱ 20 cases, stage Ⅲ 5 cases, stage Ⅳ 6 cases. According to Fuhrman grading: grade Ⅰ~Ⅱ 27 cases, grade Ⅲ 8 cases. 7 cases had renal vein or inferior vena cava thrombe. Single cell suspensions were made and labeled with fluorescence by indirect immunofluorescence technique and studied by FCM, the results were anlysised by computer. Fluorescence Index (FI) was defined as the quantitative expression index of CD44V6 and nm23-H1 protein, the FI value more than 1.0 should be considered positive expression, whereas negative expression. DNA ploidy levels was expressed by DNA Index (DI), the DI value within 1.00±0.16 should be considered DNA diploid, whereas DNA aneuploid.Results: 1. The positive expression rate of CD44V6 protein was 82.9% in renal cell carcinoma and 14.3% in corresponding paratumor tissues, the difference was statistically significant (P<0.01). Quantitative expressing FI of CD44V6 protein in RCC (1.10±0.13) were significantly higher than those in corresponding paratumor tissues (0.95±0.10), it has remarkable difference in statistics (P<0.001). 2. The positive expression of nm23-H1 protein was 48.6% in RCC and 91.4% in corresponding paratumor tissues, the difference was significant (P<0.05). Quantitative expressing FI of nm23-H1 protein in RCC (1.00±0.09) were significantly lower than those in corresponding paratumor tissues (1.09±0.08), it has remarkable difference in statistics (P<0.001). 3. Aneuploid ratios was 77.1% in RCC and 14.3% in corresponding paratumor tissues, the difference was significant in statistics (P<0.05). DNA index in renal cell carcinoma (1.28±0.18) was significantly higher than that in corresponding paratumor tissues (1.08±0.13), it has remarkable difference in statistics (P<0.001). 4. Quantitative expressing FI of CD44V6 protein in tumors sized larger than 30 mm (1.13±0.11), Robson Ⅲ~Ⅳ staging (1.21±0.08), with vasculular invasion (1.22±0.07) and metastasis (1.23±0.11) were significantly higher than those in tumors sized less than 30 mm (1.00±0.09), RobsonⅠ~Ⅱstaging (1.05±0.09), without vasculular invasion (1.07±0.10) and metastasis (1.07±0.10), it has remarkable difference in statistics (P<0.05). The expression of CD44V6 protein was not significantly related to sex, age, histological grade, clinical sympotom and cell type of RCC. 5. Quantitative expressing FI of nm23-H1 protei...