Sohei Kitazawa

Serum matrix metalloproteinase-2 and its density in men with prostate cancer as a new predictor of disease extension.

We examined whether the serum matrix metalloproteinase‐2 (MMP‐2) level and MMP‐2 density could be predictors of the development and extension of prostate cancer. Serum samples were collected before any clinical treatment from 98 patients with prostate cancer and from 76 patients with benign prostatic hyperplasia (BPH). Control sera were obtained from 70 healthy men. The serum level of MMP‐2 was determined by 1‐step enzyme immunoassay. A newly defined MMP‐2 density parameter was determined by dividing the serum level of MMP‐2 by the prostate volume, which was measured by ultrasonography. The mean serum level of MMP‐2 in prostate cancer patients was significantly higher than in the control and BPH groups. Furthermore, the serum MMP‐2 levels in prostate cancer patients with metastasis were highly elevated compared with those without metastases. The MMP‐2 density in pathologically organ‐confined prostate cancer was significantly higher than that in BPH. There was a statistically significant difference in the MMP‐2 density between pT2N0M0 and pT1N0M0 prostate cancers. Moreover, the serum MMP‐2 level correlated well with the clinical course of prostate cancer with bone metastasis. Our results suggest that MMP‐2 plays an important role in the development and extension of prostate cancer and that the serum level of MMP‐2 and the MMP‐2 density indicate prostate cancer extension and are, therefore, useful for the followup of prostate cancer patients. Int. J. Cancer (Pred. Oncol.) 79:96–101, 1998.

Cloning and characterization of the murine ?3 integrin gene promoter: Identification of an interleukin-4 responsive element and regulation by STAT-6

Expression of the αvβ3 integrin by murine bone marrow macrophages is regulated by cytokines such as IL‐4 and GM‐CSF through transcriptional activation of the β3 subunit gene. To characterize the molecular mechanisms by which such regulation occurs, we isolated the murine β3 integrin promoter. To this end, we first cloned a full length β3 cDNA and used the 5′UTR and leader peptide coding sequence to identify genomic clones containing the β3 promoter region. The transcriptional start site, identified by primer extension and S1 nuclease assay, is 34 nt upstream of the translation initiation codon. A 1.1 kb fragment of the promoter region drives IL‐4 responsive transcription in transiently transfected murine bone marrow macrophages. Deletion analysis of the β3 promoter indicates the IL‐4 responsive element lies between −465 to −678 nt relative to the transcriptional start site. This promoter fragment contains two overlapping STAT consensus recognition sites and nuclear extracts from BMMs contain an IL‐4‐inducible DNA binding factor, identified by super shift analysis, as STAT‐6. Furthermore, an oligonucleotide which includes the two STAT recognition sites residing in the IL‐4 responsive region of the β3 promoter, competes for STAT‐6 binding. Confirming IL‐4 induction of the integrin subunit is specifically mediated by STAT‐6, β3 mRNA is not enhanced in BMMs derived from STAT‐6 deleted mice, which however, retain their capacity to respond to GM‐CSF. J. Cell. Biochem. 81:320–332, 2001.

TYPE IIA EARLY GASTRIC CANCER WITH PROLIFERATION OF XANTHOMA CELLS

Abstract: We report a type IIa early gastric cancer associated with xanthoma cell proliferation in a 61-year-old man. The patient was admitted to our hospital because of a gastric polyp detected at a medical checkup. An irregular protruding lesion with xanthoma cell proliferation was detected endoscopically. Histological examination showed a well differentiated tubular adenocarcinoma in the mucosa associated with xanthoma cell proliferation. The distribution of the xanthoma cells in the stroma corresponded closely with that of the cancer cells. Neither atypism nor mitotic figures were recognized in the xanthoma cells. In an immunohistochemical study, almost all the xanthoma cells were stained positive for α1-antitrypsin, while relatively few exhibited positive S-100 protein staining. Specific monocyte chemotactic and activating factor immunoreactivity was present only in the xanthoma cells, and not in the cancer cells. On the basis of these findings, it was speculated that the gastric cancer cells may have caused the xanthoma cell proliferation via an autocrine mechanism i.e., by a chemical mediator acting in a paracrine or juxtacrine manner.

In situ detection of parathyroid hormone-related protein in ovarian clear cell carcinoma

A case of ovarian clear cell carcinoma associated with hypercalcemia is reported. A 67-year-old woman developed the lung metastasis 8 months after primary surgery. The patient manifested symptoms of humoral hypercalcemia of malignancy (HHM) during the last 3 months of her clinical course. Serum and urinary C-terminus parathyroid hormone-related protein (PTHrP) levels were remarkably high. No increase in interleukin (IL) 1beta, tumor necrosis factor (TNF) alpha, vitamin D3 metabolites or intact PTH was detected. Pamidronate disodium treatment was transiently suppressed her serum calcium level. The patient died despite seven courses of chemotherapy. Autopsy showed multiorgan metastases and accelerated osteoclastic bone resorption; skeletal metastasis was not detected. Immunohistochemical analysis clearly showed the localization of PTHrP at both the primary and metastatic sites. The transcripts of PTHrP at pulmonary metastatic sites were revealed by in situ hybridization and the reverse transcription polymerase chain reaction (RT-PCR) method. PTHrP was the causative factor for HHM in this case. It is therefore suggested that hypercalcemia may have occurred after PTHrP production had overcome the homeostatic level during the terminal stage, although PTHrP production continued irrespective of the patients serum calcium level.

Integrins and osteoclast polarization

The osteoclast is the principal, if not exclusive, resorptive cell of the skeleton. It is of hematopoietic origin [1] and a polykaryon with the capacity to degrade both the organic and inorganic matrices of bone [2]. The discovery that the osteoclast is a member of the monocyte/macrophage family has prompted development of models whereby this cell can be generated, in culture, from a variety of species [3,4], These techniques have led to major insights into osteoclast physiology and the mechanisms by which the cell differentiates and resorbs bone. Our laboratory has, during the past two decades, focused on the mechanisms of osteoclastic bone resorption. We have demonstrated that the resorptive process involves hydration of carbon dioxide to carbonic acid that dissociates into bicarbonate ions and protons. The protons are transported, via an electrogenic R+ATPase, into an isolated microenvironment at the cell-bone interface [5]. To maintain intracellular pR neutrality, bicarbonate ions are exchanged, at the antiresorptive membrane, for chloride ions [6]. These pass through the cell and are extruded by a chloride channel, unique to the osteoclast, which is charge coupled to the R+ATPase [7]. The net result of this process is secretion of hydrochloric acid into this extracellular microenvironment, bringing the pR to approximately 4.5 [8]. This acidification process leads to mineral mobilization, thus exposing the organic matrix bone, consisting principally of collagen fibers [2] that are, in turn, degraded by a family of lysosomal enzymes of the cathepsin type [9]. It is clear from the above that physical intimacy between the osteoclast and bone matrix is required for bone degradation. Our attention therefore focused on the mechanisms by which the osteoclast recognizes and binds to bone. In this regard, integrins, a family of heterodimeric transmembrane proteins consisting of ()( and ß chains, are the major mediators of cell matrix attachment. Thus, we turned to characterizing the