A dynein-associated photoreceptor protein prevents ciliary acclimation to blue light.

Light-responsive regulation of ciliary motility is known to be conducted through modulation of dyneins, but the mechanism is not fully understood. Here, we report a novel subunit of the two-headed f/I1 inner arm dynein, named DYBLUP, in animal spermatozoa and a unicellular green alga. This subunit contains a BLUF (sensors of blue light using FAD) domain that appears to directly modulate dynein activity in response to light. DYBLUP (dynein-associated BLUF protein) mediates the connection between the f/I1 motor domain and the tether complex that links the motor to the doublet microtubule. Chlamydomonas lacking the DYBLUP ortholog shows both positive and negative phototaxis but becomes acclimated and attracted to high-intensity blue light. These results suggest a mechanism to avoid toxic strong light via direct photoregulation of dyneins.

Establishment and characterization of a cisplatin-resistant cell line (IGSK-1) from a poorly differentiated gastric adenocarcinoma.

We successfully established a spontaneously cisplatin-resistant tumor cell line (designated as IGSK-1) derived from original gastric carcinoma. The patient was a 75-year-old Japanese woman. The histopathological diagnosis was gastric poorly differentiated adenocarcinoma accompanied with metastatic foci in lymph nodes, pT3, N2 M0, stage IIIB. The IGSK-1 cells grew as adhesive and monolayered cultures on the bottom of dishes. The susceptibility of the IGSK-1 cells to anti-cancer drugs was examined using oxygen electrode apparatus (Daikin, Tsukuba, JPN), and the results suggested TXL was effective, and CDDP, CPT-11 and 5-FU were not effective. Gastrin and somatostatin secretions were confirmed by immunohistochemical staining and also radioimmunoassay. Immunohistochemistry and radioimmunoassay for serotonin suggested the IGSK-1 cells might incorporate serotonin from the growth media. Spontaneously cisplatin-resistant gastric carcinoma cell line secreted gastrin and somatostatin is very important material for chemotherapy.

Establishment and characterization of EB virus-free normal B-lymphocyte and interleukin-6-producing poorly differentiated adenocarcinoma cell lines derived from gastric tumor tissue.

We successfully established two cell lines, an adenocarcinoma cell line (designated as HIGS) and Epstein-Barr virus-free normal B-lymphocyte cell line (designated as HIGS-BL), derived from a moderately to poorly differentiated adenocarcinoma of the stomach, and examined their characteristics. The tumor delivered to our laboratory from an operating room was cut into small pieces and cultured on the dishes. HIGS and HIGS-BL were established from each individual dish after the onset of primary culture. Although their culture methods were the same, the HIGS cell line was not established from the dishes growing HIGS-BL cells. In addition, HIGS-BL cells were scarcely observed in the HIGS cell dishes. Because of these factors, we have considered until now that HIGS-BL cells may inhibit the growth of HIGS cells or cause damage to HIGS cells by unknown mechanisms. Injection of HIGS-BL cells, other B-lymphocyte cell lines, or the conditioned media of HIGS-BL cells into nude mice bearing HIGS-grafted tumors was performed individually. When HIGS and HIGS-BL cells were co-cultured in the same dishes, HIGS-BL cells inhibited the proliferation of HIGS cells. The inhibition of grafted tumor growth was confirmed by the injection of not only the HIGS-BL cells but also the B-lymphocytes. Furthermore, this inhibition was only observed when the conditioned medium of B-lymphocytes was injected into the nude mice. These results suggested that the secretory products by general B-lymphocytes (including HIGS-BL) have some ability to inhibit the proliferation of HIGS cells. In addition, susceptibility tests to anti-cancer drugs suggested that HIGS cells were sensitive to CDDP, ADM and MMC, and HIGS-BL cells were sensitive to CDDP. If CDDP was used for chemotherapy in the patient, the drug produced atrophy of HIGS-BL cells. The study about HIGS and HIGS-BL cells reported the necessity for novel therapeutic approaches in oncotherapy.

Establishment and characterization of a human ovarian small cell carcinoma, hypercalcemic type, cell line (OS-1) secreting PTH, PthrP and ACTH--special reference to the susceptibility of anti-cancer drugs.

We successfully established a novel cell line (OS-1) derived from human ovarian small cell carcinoma, hypercalcemic type secreted PTH, PTH-rP and ACTH. The OS-1 cell line was established from metastatic focus of uterus. A patient was 25-year-old Japanese woman. The first she received left ovariectomy on April 2002. The histopathological diagnosis was ovarian small cell carcinoma, pT2c, Nx, Mx. Then on June 2003, metastatic focus of uterus was ectomied. A part of the recurrent tumor of uterus was cut into small pieces with razor blades, and dissociated with 0.1% trypsin-0.02% EDTA/ PBS(-) solution at room temperature. The single cells and small cell clusters were seeded into 60mm dishes and cultured in growth medium (GM: DMEM/F12 supplemented with 20% fetal bovine serum and 0.1% non-essential amino acids solution) at 37 degrees C, 4.7% CO2 in humidified air. Medium was exchanged twice a week. The OS-1 cells grew as floating cultures in the dishes. Radioimmunoassay of the conditioned media was revealed that the cultures secreted large amount of PTH, PTHrP and ACTH simultaneously. Susceptibilities of anti-cancer drugs to the OS-1 cells were examined using oxygen electrode meter (Daikin), and the results suggested VLB and TXL were effective, and CDDP, CPT-11, VP-16, VCR, CPA, MMC and CBDCA were not effective. In our knowledge, it is the first report that the cell line secreting PTH, PTHrP and ACTH was successfully established from ovarian small cell carcinoma, hypercalcemic type. We expect that OS-1 cell line contribute to study on the mechanism of ectopic hormone secretion and susceptibility of anti cancer drugs to the small cell carcinoma.