Hisao Mano

Expression of human placenta alkaline phosphatase in placenta during pregnancy

To clarify the expression of PLAP during the course of pregnancy, the amount of PLAP mRNA and its activity in normal placental villi were measured. Both PLAP and its mRNA were found in placentae of as early as 7 weeks of gestation, and they continued to increase throughout pregnancy. But they showed different patterns of increase. The amount of PLAP mRNA began to increase dramatically around 13th week and probably continued to increase gradually until term. PLAP activity per gram of villi showed a gradual increase from around 13th week and a marked increase was observed after about 20th week. PLAP levels in sera from pregnant women were also measured, and they showed a pattern of increase imilar to that of PLAP activity per gram of villi. The continuous increase in the expression of PLAP throughout pregnancy suggests that PLAP may play a role in feto-maternal metabolism and placental differentiation.

Autocrine mechanism of epidermal growth factor in choriocarcinoma cell proliferation

We examined four choriocarcinoma cell lines, NaUCC-1, NaUCC-3, NaUCC-4 and BeWo, for the presence of epidermal growth factor (EGF) by enzyme immunoassay and reverse transcription and polymerase chain reaction, and for EGF receptor (EGFR) by 125I-EGF binding assay. Specific EGF binding and EGF proteins were detected in these four choriocarcinoma cell lines. On the cell lines examined, NaUCC-4 had the greatest EGF binding capacity (18 x 10(5) sites/cell) and the highest amount of immunoreactive EGF (142 pg/ml). These results prompted us to assess the significance of EGF/EGFR autocrine mechanism in NaUCC-4 cells. Low doses of exogenous EGF stimulated 3H-thymidine incorporation, and monoclonal antibodies against EGF or EGFR dose-dependently inhibited 3H-thymidine incorporation. On the other hand, these antibodies did not significantly affect hCG production. These results suggested that EGF might function in an autocrine manner to stimulate proliferation rather than differentiation of NaUCC-4 choriocarcinoma cells.

Tumoricidal effect of human macrophage-colony-stimulating factor against human-ovarian-carcinoma-bearing athymic mice and its therapeutic effect when combined with cisplatin

The effect of human macrophage-colony-stimulating factor (hM-CSF) on tumoricidal activity was examined in athymic mice bearing the human ovarian cancer cell line, HRA, injected intraperitoneally (i.p.). The survival period and survival rate in the groups treated daily with hM-CSF were significantly longer (P<0.01) than in the untreated group. The peritoneal cell smears showed that ascitic tumor cells were markedly decreased in the hM-CSF-treated groups, and macrophages phagocytosed tumor cells, indicating a contact-mediated direct cytolysis. The combined therapeutic effects of cisplatin and hM-CSF on HRA-bearing athymic mice were also studied. The mean survival period was 25.4, 47.2, 42.4 and 67.4 days, respectively, in the untreated group, and in the groups treated with cisplatin alone, with hM-CSF alone, and with combined cisplatin and hM-CSF. The survival period and rate were significantly longer (P<0.01) in the group treated with combined cisplatin and hM-CSF than in those treated with cisplatin or hM-CSF alone, indicating the therapeutic effectiveness of the combined use. Morever, hM-CSF is effective against granulocytopenia due to bone marrow suppression caused by cisplatin. Our data demonstrate that hM-CSF administered i.p. has a tumoricidal activity in athymic mice bearing human ovarian cancer i.p., which is mediated by activated macrophages, and that the combined administration of cisplatin and hM-CSF has a significant therapeutic effect.

Prophylactic effect of bestatin on the onset of invasive mole — clinical and fundamental studies

This study was performed to determine whether bestatin (Ubenimex) has clinical prophylactic effects on the onset of invasive mole and a direct inhibitory effect on the growth of hydatidiform molar cells. A total of 49 patients with hydatidiform mole treated at Nagoya University Hospital from 1984 to 1990 were randomly divided into two groups, a bestatin administered-group and a bestatin non-administered group. Patients in the bestatin group were given 30 mg of bestatin orally and daily for three months just after their molar deliveries. There was no significant difference in age, gravidity, parity and gestational weeks between the two groups. There was also no significant difference in the duration of human chorionic gonadotropin (hCG) negative conversion in patients without invasive mole between the two groups. However, the incidence of invasive mole in the bestatin group (2/25, 8%) was significantly lower than that of the non-bestatin group (7/24, 29.2%). Nevertheless, there was no significant difference between the two groups in such immunological parameters as PHA skin test, PPD skin test, PHA stimulation index (PHA-SI), white blood cell (WBC) count lymphocytes % per WBC, OKT 3% per lymphocytes, OKT 4% per lymphocytes, OKT4/OKT8 and Leu 11% per lymphocytes. In vitro studies were performed with primary cultured hydatidiform moles. The result was that bestatin inhibited the secretion of hCG and3H-thymidine uptake of hydatidiform molar cells. Thus, a possibility was suggested that bestatin directly inhibits the growth of hydatidiform molar cells and prevents the onset of invasive mole.