Immunohistochemical studies of caveolin-3 in germ cell tumors of the testis

BACKGROUND/AIM: Caveolin, which is a major constructive component of the caveolar membranes, plays a key role in transcytosis of molecules into cells and regulation of several signal transductions. Caveolin has three isoforms, and recent studies suggest that in some malignant tumors an alteration of caveolin-1 expression correlates with oncogenetic changes. Caveolins have been reported to be negative regulators of inducible nitric oxide synthase (iNOS) which can provoke an antitumor response via infiltrating immune cells. The aim of this study was to examine the expressions of caveolin-1 and caveolin-3 (which is a caveolin-1 homologue localized predominantly in muscle tissue) in testicular cancer. METHODS: We evaluated the expressions of caveolin-1, caveolin-3, and iNOS in 16 seminoma and 10 non-seminoma testicular cancer specimens as well as normal testicular tissue, using a streptavidin-biotin bridge technique on cryostat sections. The expression of caveolin-3 was confirmed by slot-blot analysis. Tumor-infiltrating immune cells were also studied immunohistochemically, and the correlation between the number of immune cells and caveolin-3 concentrations was calculated. RESULTS: Immunohistochemistry revealed that caveolin-3, but not caveolin-1, was frequently expressed in seminomas (12 positive out of 16 specimens) without positive staining in their normal counterparts or in nonseminomatous germ cell tumors, except for muscle components in the teratoma. iNOS was not expressed in any tissues examined. Samples with high levels of caveolin-3 tended to have higher degrees of tumor-infiltrating immune cells, although this finding was not statistically significant. CONCLUSION: This is the first report demonstrating the involvement of caveolin-3 in germ cell tumors.     

Online parameter identification of second-order systemic circulation model using the delta operator

To develop effective medical care with the artificial heart, we proposed a new method that can calculate the time varying and unmeasured hemodynamics of the human body from measured physiological data: aortic pressure, aortic flow, and pump flow in real time. This method comprises first, the second order of systemic circulation model, which consists of aortic compliance (Ca), aortic resistance (Ra), aortic inertia (L), and total peripheral resistance (Rp); and second, system identification using the delta operator. In the computer simulation, we confirmed the effectiveness of this method. During the animal experiment with the left ventricular assist system, the physiological parameters could be identified online: mean Ra = 0.04 mm Hg s/ml, mean Ca = 0.65 mm Hg/ml, mean L = 0.004 mm Hg s(2)/ml, and mean Rp = 0.3 mm Hg s/ml. This new method efficiently identified the physiological parameters, which are important not only to support the medical care but also to develop the control method adapted to the physiological behavior.     

Sleep habits of students attending elementary schools,and junior and senior high schools in Akita prefecture

It is widely accepted that students in Japan sleep fewer hours than what they actually need. However, epidemiological data on sleep habits among students are scarce. The sleep habits and related problems among 1650 students in Akita prefecture were studied. The results revealed that schoolchildren attending elementary schools seemed to sleep for a sufficient number of hours, whereas students attending junior or senior high schools were not sleeping enough. In particular, approximately half of the students attending senior high schools answered that they slept 6 h or less on weekdays and nodded off during classes more than twice a week.     

Transformation by inorganic arsenic compounds of normal Syrian hamster embryo cells into a neoplastic state in which they become anchorage-independent and cause tumors in newborn hamsters

Arsenic is a known human carcinogen, but little evidence exists for its carcinogenicity in animals. In order to investigate the ability of inorganic arsenics to transform normal cells into a neoplastic state, mass cultures of normal, diploid Syrian hamster embryo (SHE) cells exposed to various concentrations of sodium arsenite or sodium arsenate for 48 hr were continually passaged and tested for neoplastic transformation, as determined by anchorage-independent growth in semisolid agar and tumorigenicity in newborn hamsters. Twenty-one of 22 (96%) untreated, control cultures senesced by 20 passages. While 1 culture escaped senescence, it did not acquire the ability to either grow in semisolid agar or form tumors in animals. Ten of 14 (71%) cultures exposed to sodium arsenite or sodium arsenate escaped senescence. Nine of the 10 (90%) arsenic-treated immortal cultures acquired the anchorage-independent phenotype. Five of 5 anchorage-independent cultures examined were tumorigenic. Two of 3 morphologically transformed colonies induced by sodium arsenate also acquired the ability to grow in semisolid agar when isolated. Amplification of the c-myc or c-Ha-ras oncogene was detected in 3 of 5 and 4 of 5 tumorigenic cell lines, respectively. Both c-myc and c-Ha-ras were amplified even in a preneoplastic, anchorage-dependent cell line, but neither was amplified in 6 of 9 anchorage-independent cell lines. Overexpression of c-myc and c-Ha-ras mRNA was observed in most of the neoplastically transformed cell lines but not in the preneoplastic cell line. Experiments using the methylation-sensitive restriction endonuclease isoschizomers HpaII and MspI revealed hypomethylation of c-myc and c-Ha-ras in the 5'-CCGG sequence of arsenic-exposed cell lines but not in the parental SHE cells or a spontaneously transformed cell line. Thus, inorganic arsenics induce neoplastic transformation of normal, diploid mammalian cells. Overexpression of oncogenes by DNA hypomethylation may participate in the arsenic-induced neoplastic transformation of mammalian cells.     

Prognostic value of c-erbB2 expression in breast cancer

BACKGROUND AND OBJECTIVES: An overexpression of c-erbB2 has been reported to be associated with a poor clinical outcome in breast cancer, however, its prognostic value remains controversial especially in patients with node negative breast cancer, and regarding the estrogen receptor (ER) status. METHODS: Immunohistochemical staining for c-erbB2 was performed on the primary breast cancer from 698 Japanese patients with a mean follow-up duration of 54 months. RESULTS: The c-erbB2 expression was positive in 120 (17.2%) of 698 cases, which inversely correlated with the ER status. Both univariate and multivariate analyses indicated the c-erbB2 expression to be a significant prognostic factor for the disease-free survival (DFS) and overall survival (OS), while the same effect was also seen in the patient groups with node negative as well as node positive breast cancer. A univariate analysis also indicated a subgroup with the positive c-erbB2 and negative ER to have both a worse DFS and OS than the other subgroups. The patients with positive c-erbB2 had a significantly worse DFS and OS than the patients with negative c-erbB2 in all patient groups stratified according to the adjuvant therapies, while the prognostic significance of c-erbB2 on DFS was also found in the patients with the node negative breast cancer who received adjuvant tamoxifen alone. CONCLUSIONS: The c-erbB2 expression is an independent significant factor for breast cancer and the prognostic significance remains in the node negative as well as node positive breast cancer, while the same effect was also found in all subgroups stratified according to the adjuvant therapies. In addition, the combination of c-erbB2 and ER made it possible to identify the subgroup with the worst clinical outcome.     

Growth inhibitory effect of paradicsompaprika in cancer cell lines

We investigated whether components of paradicsompaprika have direct antitumor effects or inhibitory effects on cancer growth, using its water extract. We applied collagen gel droplet embedded culture drug sensitivity test (CD-DST) as a screening method, which was developed based on the characteristics of cell culture on collagen matrix. Colon adenocarcinoma cells, epithelial cells of lung cancer, and cervical cancer cells were used. Paradicsompaprika is classified as Capsiucum annume L. var. grossum of Solanaceae. It is the first of the Hungarian species that was planted in Japan. It is available as TOMA-P in Japan. TOMA-P contains abundant carotenoids including capsanthin and beta-carotene. Water extract of paradicsompaprika was added to each cell at each concentration, and the mixture was cultured for 24 h and 7 days. The inhibitory effects against lung cancer and cervical cancer were observed concentration- and time-dependently. The effect was more prominent against lung cancer. The growth of bowel cancer cells was observed after the 7-day exposure of paradicsompaprika at the concentrations below the highest concentration compared to the control. At the highest concentration, the growth inhibition was not different between the 24-h exposure and the 7-day exposure, which suggests that tumor dormancy was induced. Results of the present study suggest that the water extract of paradicsompaprika can be a candidate of a new anticancer agent. Fat soluble component of paradicsompaprika, capsanthin is regarded as an anti-promoter of cancer. Thus, paradicsompaprika possesses chemopreventive and inhibitory effects on cancer cells.     

Prediction of cell kill kinetics of anticancer agents using the collagen gel droplet embedded-culture drug sensitivity test

A vital component of chemotherapy is selecting effective anticancer agents for the patient and determining an appropriate dose and administration regimen. Prediction of the drug sensitivity of each patient and cell kill kinetics of the drug may improve the outcome of treatment and avoid unnecessary dosing of the drug. For this reason, the development and clinical application of anticancer drug sensitivity tests and cell kill kinetics tests which successfully reflect clinical outcomes are required. In the present study, we tried to establish a cell kill kinetics test through the use of new anticancer agents: paclitaxel, docetaxel, SN-38, vinorelbine, and gemcitabine. These agents were studied at concentrations close to their clinical doses using a collagen gel droplet embedded-culture drug sensitivity test (CD-DST). It is thought that the mechanism, by which the anticancer agents used in this study exert their effects is dependent on the cell cycle; however, the cell kill kinetics of these agents at clinical concentrations has not yet been clarified in vitro. We investigated the drug sensitivity and cell kill kinetics of these new anticancer agents against a human colon cancer strain. Results of this study suggest that the test method established by us can predict drug sensitivity and cell kill kinetics of the agents, and can be a useful tool in deciding appropriate treatment regimen for individual patients.