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Background: Adrenomedullin (AM) has pluripotent activities and is involved in the regulation of vasomotor tone, cell differentiation and embryogenesis. However, the expression and pathophysiological role of AM has not been determined in human renal cell carcinoma (RCC)., Methods: Twenty-six RCC specimens and three cultured human RCC cell lines (A498, SN12C and KPK-13) were analyzed. Expression of AM was determined by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) analysis. The correlation between AM expression and microvessel count (MVC) in RCC specimens was examined to determine if AM plays a role in tumor angiogenesis. The correlation between the expression of AM and vascular endothelial growth factor (VEGF) was also investigated. Lastly, the effect of hypoxia upon the mRNA expression of AM, VEGF and hypoxia inducible factor-1 (HIF-1) by RCC cell lines was determined., Results: Immunohistochemistry indicated that AM and VEGF were primarily localized in the cytosol of RCC cells. AM and VEGF mRNA were detected in all RCC specimens and cultured RCC cell lines analyzed by RT-PCR. There was a positive correlation between AM mRNA expression and MVC (r = 0.516, P = 0.0062), and between VEGF mRNA expression and MVC (r = 0.485, P = 0.0111). We also observed a positive correlation between AM mRNA expression and VEGF mRNA expression (r = 0.552, P = 0.0029). Hypoxia significantly induced AM and VEGF mRNA expression, although the increase of the AM mRNA level (10.6-26.7 fold) was markedly greater than that of the VEGF mRNA level (1.5-1.9 fold)., Conclusion: These results suggest that hypoxia-induced AM plays a part in tumor angiogenesis in conjunction with VEGF and facilitates human RCC growth under hypoxic conditions.

Purpose: The usefulness of laparoscopy-assisted total nephroureterectomy for patients with renal pelvic and lower ureteral cancer is evaluated., Material: Seven patients with renal pelvic cancer and four with lower ureteral cancer performed laparoscopy-assisted total nephroureterectomy from May 1997 to December 2000 (Ten males and one female, mean age 68.5 year-old)., Method: Of the 11 patients, the initial one received preoperative embolization of the renal artery. Under general anesthesia laparoscopy-assisted total nephroureterectomy underwent via transperitoneal approach in three patients and retroperitoneal approach in eight. After the kidney was completely dissected under laparoscopic procedure, it was delivered en bloc with ureter from the skin incision in the lower abdomen., Result: Two patients needed conversion to open surgery. The mean operating time of nine patients except for conversion cases was 272 minutes and the mean blood loss was 313 ml. There was no major complication associated with laparoscopic procedure. There was no significant difference in both complication and recurrence rate between laparoscopy-assisted total nephroureterectomy and open surgery., Conclusion: Laparoscopy-assisted total nephroureterectomy is an useful procedure for the treatment of patients with renal pelvic and lower ureteral cancer because it enables us to remove out the kidney and ureter from one small lower abdominal incision.

A 49-year-old woman had been on hemodialysis for 18 years. She presented with left back pain and macrohematuria. Radiologic studies demonstrated a left renal tumor with acquired cystic disease of the kidney. Her serum erythropoietin (EPO) level was 78.4 U/L despite no history of EPO supplementation. Left radical nephrectomy was performed. Pathologic examination revealed EPO-producing renal cell carcinoma. After surgery, the patient's serum EPO level decreased markedly to 15.1 U/L. The measurement of serum EPO levels may be useful for detecting and monitoring a recurrence of renal cell carcinoma with acquired cystic disease of the kidney in patients on long-term hemodialysis.

Objective: To investigate the role of vascular endothelial growth factor (VEGF) in tumour angiogenesis in renal cell carcinoma (RCC)., Materials and Methods: The expression of VEGF was examined in tissue samples from 25 patients with RCC using the reverse-transcriptase polymerase chain reaction (RT-PCR). Cellular localization of VEGF was studied in normal kidney and RCC tissues. Tube formation by human omental microvascular endothelial (HOME) cells co-cultured with A498 RCC cells was quantified in a three-dimensional collagen gel using computer-image analysis., Results: RT-PCR detected VEGF m-RNA in tissue from 20 of 25 patients with RCC. An immunohistochemical study revealed that VEGF was primarily localized in the cytosol of normal renal tubule cells and RCC cells. Tube formation by HOME cells was increased in the presence of A498 cells overexpressing VEGF mRNA, induced by exogenous VEGF in a dose-dependent manner and completely inhibited by an anti-VEGF antibody., Conclusion: VEGF, which is produced and released from RCC cells, may elicit tumour angiogenesis by inducing microvessel tubulogenesis in patients with RCC. The co-culture system may be useful for screening inhibitors of tumour angiogenesis in RCC.