Michihiko Hasegawa

Prevention of renal cell carcinoma by active vitamin D3.

A bstractWe studied the serum levels of 1,25-dihydroxyvitamin D [1,25(OH)2D (Vit D)] in patients with renal cell carcinoma (RCC) and the influence of 1,25(OH)2D3 (Vit D3) on gap junctional intercellular communication (GJIC) during carcinogenesis. The serum Vit D levels were measured by a competitive protein-binding assay using the chromatographic method. Using the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay, noncytotoxic concentrations of Vit D3 and the tumor promoters N-nitrosodimethylamine (NDMA) and N-ethyl-N-hydroxyethylnitrosamine (EHEN) were tested against cultured human renal proximal tubular cells (HRPTCs). GJIC function was assayed by the scrape-loading dye transfer technique. Cx43 mRNA expression was also examined by the reverse transcriptase-polymerase chain reaction (RT-PCR). Serum Vit D levels in patients with RCC were lower than those in controls (p < 0.001). Patients with T3 to T4 (rapid-growth) tumors had lower levels of Vit D than did patients with T1 to T2 (slow-growth) tumors (p < 0.001). Vit D3 enhanced the GJIC function of HRPTCs (p < 0.05), whereas NDMA and EHEN suppressed it (p < 0.05). When the cells were treated with tumor promoters and Vit D3 simultaneously, the GJIC functions remained at pretreatment levels. We also demonstrated Cx43 mRNA expression in RPTECs treated with EHEN and VitD3 simultaneously. These data suggest that a decrease in the serum Vit D level is one of the risk factors for development and progression of RCC, and Vit D3 may prevent RCC by preserving GJIC during carcinogenesis.

Prevalence of renal cell carcinoma: A nation-wide survey in Japan, 2002

Objective:  To investigate the incidence of renal cell carcinoma, classified by sex, age group and region in Japan, following a 5‐year interval after a previous survey performed in 1997.

Primary mucosa‐associated lymphoid tissue‐type lymphoma arising in the kidney

Abstract:  We report a case of primary low‐grade lymphoma of mucosa‐associated lymphoid tissue (MALT) arising from the kidney in a 30‐year‐old man with an abdominal mass in the right flank detected by ultrasonography. Radical nephrectomy was performed under a preliminary diagnosis of renal cell carcinoma. The final histological diagnosis was MALT‐type lymphoma. To the best of our knowledge, only five reports of primary MALT‐type lymphoma in the kidney have been published in the literature so far. All cases were surgically treated and only one case went on to chemotherapy postoperatively.

Surgical outcomes of partial nephrectomy for renal cell carcinoma : A joint study by the Japanese Society of Renal Cancer

Objective:  A joint study was undertaken by the Japanese Society of Renal Cancer to investigate the present status of partial nephrectomy in Japan and to speculate about what may be the indications for partial nephrectomy in patients with renal cell carcinoma.