Shuhei Sumi

Telomerase activity in renal cell carcinoma

Telomerase activity has been shown to be increased in numerous tumors and cell lines, although to the authors knowledge there has been no previous assessment of telomerase activity in renal cell carcinoma (RCC). To examine whether telomerase activity could be used as a biochemical parameter for predicting the behavior of RCC, telomerase activity was quantified in RCC samples and correlated with clinicopathologic findings.

Studies of the Expression of Epidermal Growth Factor Receptor in Human Renal Cell Carcinoma: A Comparison of Immunohistochemical Method versus Ligand Binding Assay

We evaluated the expression of epidermal growth factor receptor (EGFR) in 21 patients with renal cell carcinoma (RCC) by immunohistochemical staining of frozen tumor sections using a monoclonal antibody for EGFR and by a ligand binding method using radiolabeled epidermal growth factor. EGFR was detected in 16 of the 21 cases by ligand binding, while 11 of the 21 cases were detected by immunohistochemical staining. A significant correlation was observed between the two methods in detecting EGFR (p < 0.0001). EGFR was detected by the ligand binding method in all patients who died of RCC. Four cases that were graded as EGFR-negative on immunohistochemistry died of RCC. Observations suggest the ligand binding method was more sensitive than the immunohistochemical method in detecting EGFR and forecasting patient survival.

A precursor form of human kidney γ-glutamyl transferase in normal and cancerous tissues, and its possible post-translational modification

We have found three molecular forms of human gamma-glutamyl transferase (GGT) in normal and renal cell carcinomatous tissues, and also have reported the marked differences in the sugar chains of GGTs between normal and cancerous tissues by serial lectin affinity chromatographies. In this study, the peptide maps of three purified GGTs (79 kDa, 50 kDa and 25 kDa) obtained by lysylendopeptidase digestion, the subcellular localization of GGTs, and the sugar chains of GGTs were compared between normal and cancerous tissues. According to the results, the total peptide bands of the digested 79 kDa component represented the sum of those of the digested 50 and 25 kDa components on 12.5% SDS-PAGE. In addition, C-terminal and N-terminal amino-acid sequences of the 79 kDa protein were the same as the sequences of light and heavy subunits, respectively, suggesting that the 79 kDa component is of the precursor form of the 50 kDa mature heavy and 25 kDa light subunits, respectively. On the other hand, the GGT activity in renal cell carcinomatous tissues was significantly increased in the microsomal fraction and decreased in the soluble fraction compared with that of normal tissues. Meanwhile, the sugar moiety of GGTs in the respective subcellular fractions was obviously different between normal and cancerous tissues. In particular, a reduced multiantennary complex type sugar chain and an elevated high-mannose or hybrid-type sugar chain in the microsomal fraction were observed in the GGT in cancerous tissues.

Serum levels of the carboxy-terminal propeptide of type I procollagen and the pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen as markers of bone metastases in patients with prostate carcinoma.

OBJECTIVESnTo evaluate serum levels of the carboxy-terminal propeptide of type I procollagen (PICP) and the pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen (ICTP) as possible markers of bone metastases in patients with prostate carcinoma (PCA) patients.nnnMETHODSnLevels of PICP and ICTP were measured by radioimmunoassay of serum from 29 patients with benign prostatic hyperplasia (BPH), 17 patients with PCA without bone metastases and 29 patients with PCA and bone metastases.nnnRESULTSnSerum levels of PICP in patients with PCA and bone metastases (mean +/- SD 304.3 +/- 365.9 ng/ml) were significantly higher than those in patients with BPH (95.6 +/- 27.1 ng/ml) and in patients with PCA without bone metastases (111.1 +/- 44.6 ng/ml). No significant difference was observed between the BPH and the PCA without bone metastases groups. Serum levels of ICTP were significantly higher in the PCA with (10.4 +/- 10.3 ng/ml) and without bone metastases groups (7.7 +/- 6.0 ng/ml) than in the BPH group (3.7 +/- 2.0 ng/ml). There was no significant difference between the PCA groups with and without bone metastases.nnnCONCLUSIONnSerum PICP levels correlate well with results of bone scans, while serum ICTP levels increase in patients with PCA regardless of the presence of bone metastases.

前立腺特異抗原 (PSA) 測定キット間の測定値の違いについての検討

PURPOSEnWe conducted this study to examine differences in characteristics of immunoreactivity for free PSA and alpha(1)-antichymotrypsin complex PSA (ACT-PSA) as well as in compositions and concentrations of PSA reference materials among commercially available PSA kits.nnnMETHODSnFractionated serum samples using a Sephacryl S-200 column were measured by Tandem-R, Delfia-PSA, Ab bead PSA, ACS-PSA, Markit-M and gamma-seminoprotein (gamma-Sm) kits. The calibrators of Tandem-R, Delfia-PSA, Ab bead PSA and Markit-M were fractionated by the same method and measured by Tandem-R. The calibrators of Delfia-PSA, Ab bead PSA and Markit-M and control serums of ACS-PSA were measured by Tandem-R.nnnRESULTSnAlthough the characteristic of immunoreactivity of Tandem-R, Delfia-PSA, and Ab bead PSA were found to be similar, they were not shown identical. ACS-PSA was proved to recognize free PSA greater than above three PSA kits, while Markit-M could scarcely detect free PSA. gamma-Sm recognized only free PSA. The calibrators of Tandem-R, Delfia-PSA, Ab bead PSA and Markit-M were proved to be only free PSA. The linear correlation was obtained between Tandem-R and Delfia-PSA or Ab bead PSA or Markit-M. The ratio of Delfia-PSA to Tandem-R, Ab bead PSA to Tandem-R and Markit-M to Tandem-R was 0.66, 0.93 and 2.2, respectively. With regard to relation of ACS-PSA and Tandem-R, two ratios of 0.22 and 0.25 were obtained between the two kits according to the different concentrations of control sera.nnnCONCLUSIONnThe present studies suggest that the difference in PSA values among the commercial PSA kits results from (1) different characteristics of immunoreactivity for ACT-PSA and free PSA among PSA kits, (2) compositions of PSA calibrators among the kits, and (3) different concentrations of PSA calibrators among the kits.