Natsuki Takaha

Molecular cloning and functional expression of gicerin, a novel cell adhesion molecule that binds to neurite outgrowth factor

Gicerin is an integral membrane glycoprotein of about 82 kd that is transiently expressed in the developing CNS. Gicerin was first identified as a binding protein for neurite outgrowth factor (NOF), a member of the laminin family of extracellular matrix proteins. By isolating and sequencing a gicerin cDNA, we have found that this protein is a novel member of the immunoglobulin superfamily. The deduced protein (584 amino acids) consists of five immunoglobulin-like loop structures in an extracellular domain, a single transmembrane region, and a short cytoplasmic tail. Cells transfected stably with gicerin cDNA adhered to NOF and aggregated with each other, indicating that gicerin exhibits both heterophilic and homophilic adhesion activities.

Bacillus Calmette–Guérin Perfusion Therapy for the Treatment of Transitional Cell Carcinoma in situ of the Upper Urinary Tract

Objectives: The aim of this study is to evaluate the efficacy and safety of intrarenal bacillus Calmette–Guérin (BCG) instillation as a treatment for transitional cell carcinoma in situ (CIS) of the upper urinary tract.Methods: Diagnostic criteria of upper urinary tract CIS were (1) positive urinary cytology, (2) negative multiple random biopsy of the bladder and prostatic urethra, (3) negative radiographic findings in the upper urinary tract and (4) two serial positive cytologies in selective ipsilateral urine sampling from the pyeloureteral system. Eleven patients diagnosed as having upper urinary tract CIS were enrolled in this study. Thus, 11 renal units were treated with BCG instillation. After placing a 6–french Double–J stent, BCG (80 mg) in 40 ml saline was instilled into the bladder weekly, 6 times in total as one course.Results: At the end of one course, 9 cases showed negative urinary cytology. Among these 9 cases, 2 showed recurrence in the upper urinary tract after 4 months and 8 months of disease–free interval, respectively. These 2 cases have received an additional course of BCG instillation, but the urinary cytology did not normalize. Mean recurrence–free time was 19.6 months. Of the other 7 cases who responded to the first course of instillation, 6 cases were alive with no evidence of the disease. The remaining patient died of rectal cancer with no evidence of transitional cell carcinoma (TCC). Of the 2 cases who showed positive urinary cytology even after the first course, 1 underwent nephroureterectomy. The other case was diagnosed as having malignant lymphoma 3 months after the end of this instillation therapy, and he died of malignant lymphoma. As side effects, 8 cases (72.7%) showed bladder irritability, and 4 presented fever higher than 38°C. However, no patient needed antitubercular treatment.Conclusion: As for the short–term response, BCG instillation for the treatment of upper urinary tract CIS is considered to be effective and safe. Longer follow–up and further experience with this treatment are required.

Expression and Functional Analysis of a Novel Isoform of Gicerin, an Immunoglobulin Superfamily Cell Adhesion Molecule

We have cloned a novel cDNA of gicerin, a cell adhesion molecule belonging to the immunoglobulin superfamily. Both gicerin isoforms share the same extracellular domain, which has five immunoglobulin-like loop structures and a transmembrane domain as s-gicerin, but differ in the cytoplasmic tail domain. As the newly identified form has a larger cytoplasmic domain than the previously reported form, we refer to them as l-gicerin and s-gicerin, respectively. l-gicerin is transcribed from a distinct mRNA containing an inserted sequence not found in s-gicerin mRNA which caused a frameshift for the coding region for a cytoplasmic domain. Previous studies demonstrated that gicerin showed a doublet band of 82 and 90 kDa in chicken gizzard smooth muscle. We report that the 82-kDa protein corresponds to s-gicerin and the 90-kDa protein to l-gicerin. We also found that the two gicerin isoforms are expressed differentially in the developing nervous system. Functional analysis of these gicerin isoforms in stable transfectants revealed that they had differ in their homophilic adhesion properties, as well as in heterophilic cell adhesion assayed with neurite outgrowth factor. In addition, these isoforms have neurite-promoting activity by their homophilic adhesion, but differ in their ability to promote neurite outgrowth.

Oral Combination of Cyclophosphamide, Uracil plus Tegafur and Estramustine for Hormone-Refractory Prostate Cancer

Objective: To evaluate the clinical usefulness of an oral combination of cyclophosphamide, uracil plus tegafur (UFT) and estramustine in the treatment of patients with hormone-refractory prostate cancer (HRPC). Methods: Twenty-one patients were treated with oral administration of cyclophosphamide (100 mg/day), UFT (400 mg/day) and estramustine phosphate (560 mg/day). The median age of the patients was 70 years. Twelve patients had symptomatic bone metastasis, 6 had asymptomatic bone metastasis, 5 had lymph node metastasis, while 2 had only biochemical progression evaluated by prostate-specific antigen (PSA). Results: Twelve (57%) out of 21 patients showed a PSA decline of 50% or greater. The median response duration was 7 months (range 2–15 months). Among the 20 patients assessable for bone pain, 2 (10%) improved, 12 (60%) remained stable and 6 (30%) progressed. Among the 10 patients assessable for bone metastasis, 1 (10%) improved, 5 (50%) were stable and 4 (40%) progressed on bone scan. Among 3 patients assessable for measurable disease (lymph node metastasis), 2 (67%) showed partial response and 1 (33%) progression. Most toxicities were mild. Conclusions: The combination of cyclophosphamide, UFT and estramustine is an active and well-tolerated regimen for HRPC. To evaluate the survival benefit, further randomized studies are required.

Nuclear matrix localization of high mobility group protein I(Y) in a transgenic mouse model for prostate cancer

Nuclear shape and the underlying nuclear structure, the nuclear matrix in cancer cells. Since the NM composition is considered to maintain nuclear shape and architecture, nuclear matrix proteins (NMPs) may be involved in transformation. Our laboratory has recently characterized a subset of NMPs that are associated with prostate cancer development in the transgenic adenocarcinoma of mouse prostate (TRAMP) model. One of the identified NMPs, E3E, has a similar molecular weight (22 kDa) with a protein known as HMGI(Y). HMGI(Y) belongs to a group of non‐histone and chromatin‐associated proteins, high‐mobility‐group (HMG) proteins, and it has been shown to associate with the NM. HMGI(Y) has been reported to be elevated in different types of cancer including prostate cancer. In this study, we examined the expression of HMGI(Y) protein in the NMP composition of the TRAMP model during the progression from normal to neoplasia. The expression of HMGI(Y) in the NMP extracts of three prostatic epithelial cell lines derived from a 32‐week TRAMP mouse: TRAMP‐C1, TRAMP‐C2, and TRAMP‐C3 was also examined. Using both one‐dimensional and high‐resolution two‐dimensional immunoblot analyses, we found that: (i) HMGI(Y) is a nuclear matrix protein expressed as two protein bands with MW of 22–24 kDa and (ii) HMGI(Y) expression is correlated with neoplastic and malignant properties in late stage TRAMP prostate tumors. Overall, these findings support the evidence that HMGI(Y) can be utilized as a marker and prognostic tool for prostate cancer.

Extracellular matrix proteins with neurite promoting activity and their receptors.

Characteristic features of the nervous system converge into network formation during the development. The neurons recognize precisely their target cells and form synapses, and these steps are complex, but well organized spatially and temporally. The neurite promotion from the neurons is one of the most important events for synapse formation. It is well known that extracellular matrix proteins such as laminin and their receptors, and cell adhesion molecules such as NCAM participate in cell migration and synaptic formation. We have isolated a neurite outgrowth factor (NOF) which promotes neurite outgrowth from various neurons and belongs to laminin family, and also its receptor which is identified to be an immunoglobulin superfamily protein by cDNA cloning. This ligand-receptor system is a unique example that a receptor with immunoglobulin-like structure interacts with an extracellular matrix protein.

Relation between Erectile Dysfunction and Urinary Incontinence after Nerve-Sparing and Non-Nerve-Sparing Radical Prostatectomy

Introduction: We investigated the status of erectile function and urinary continence after radical prostatectomy to investigate a possible relation between them and then determined whether the status of postoperative urinary continence affected erectile function. Patients and Methods: Seventy-six patients who had no symptoms of erectile dysfunction or urinary incontinence preoperatively were included in this study. The postoperative status of erectile function and urinary continence was investigated using a self-reported patient questionnaire. Results: Thirteen of 27 patients (48.1%) who underwent nerve-sparing procedures maintained erectile function, while 7 of 49 patients (14.2%) who underwent non-nerve-sparing procedures maintained it postoperatively. None of the 27 patients in the nerve-sparing procedure group reported incontinence, whereas 3 of the 49 patients (6.1%) who underwent non-nerve-sparing procedures reported moderate incontinence. However, no significant correlation between the International Index of Erectile Function-5 score and the Incontinence Impact Questionnaire score was seen. Conclusion: No relation between the status of urinary continence and erectile function was shown, regardless of the nerve-sparing nature of the prostatectomy.

Nerve-sparing retroperitoneal lymph node dissection for advanced testicular cancer after chemotherapy

Background: Nerve‐sparing techniques are commonly used in retroperitoneal lymph node dissection (RPLND) in patients with early stage testicular germ cell tumors to preserve postoperative ejaculation. The indications for nerve‐sparing procedures have been extended to patients who have residual retroperitoneal tumor postchemotherapy with an increase in the incidence of local recurrence. Here, we report on 26 Japanese men with advanced testicular cancer who underwent nerve‐sparing RPLND after partially successful chemotherapy.

Adhesive activity of gicerin, a cell-adhesion molecule, in kidneys and nephroblastomas of chickens

Abstract Gicerin, a cell-adhesion molecule belonging to the immunoglobulin superfamily, has both homophilic and heterophilic binding activities to neurite outgrowth factor, an extracellular matrix molecule in the laminin family. Gicerin is thought to play a role in the normal development of chicken kidney, because it is expressed abundantly in the embryonic organ and only slightly in the mature organ. In this study, we have examined the adhesive activity of gicerin in the kidney to characterize its function in organogenesis. We have also examined the function of gicerin in chicken nephroblastomas (“embryonic nephromas”), which show various structures resembling those in embryonic kidneys. Immunohistochemically, the expression patterns of gicerin and neurite outgrowth factor in nephroblastomas are similar to those of embryonic kidneys. Cell-aggregation assays have shown that primary culture cells from both embryonic kidneys and nephroblastomas have strong aggregation activities, and that each aggregation is partially inhibited by gicerin antibody. In contrast, cells from adult kidney exhibit weak aggregation activity that is not inhibited by the antibody. In addition, ligand blot analysis has revealed that gicerins in embryonic kidney and nephroblastoma bind to purified neurite outgrowth factor, whereas extracts from adult kidney show no positive reaction. These findings suggest that the homophilic and heterophilic adhesive activities of gicerin are involved in the formation of both normal kidney and nephroblastoma.

Feasibility of Tri-Weekly Docetaxel-Based Chemotherapy for Elderly Patients (Age 75 and Older) with Castration-Resistant Prostate Cancer

Objectives: To evaluate the efficacy and safety of docetaxel-based chemotherapy for elderly metastatic castration-resistant prostate cancer (CRPC) patients aged 75 or higher. Methods: Twenty CRPC patients aged 75 or higher (older group) and 31 CRPC patients younger than 75 years (younger group) were treated by a regimen of docetaxel (70 mg/m2) once every 3 weeks. Adjustment for docetaxel dosage and period per cycle was subject to investigator’s judgment. Results: The median relative dose intensity of both groups was 0.84, while the median dose intensity and the number of treatment cycles of the younger and older groups were 14.6 versus 12.3 mg/m2/week (p = 0.021), and 9 versus 8 cycles (p = 0.15), respectively. In the older group, PSA response rate was 50%, median time to biochemical progression was 7.5 months, and median survival time was 15.5 months, without any significant difference compared to those of the younger group. No significant difference in the incidence of grade 3–4 adverse events was noted between both groups. All these parameters for efficacy are comparable to those reported for tri-weekly docetaxel regimen. Conclusions: Tri-weekly treatment by docetaxel (70 mg/m2) with proper adjustment might contribute to maintaining efficacy and safety of the treatment for elderly CRPC patients.