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.

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.

[Leiomyosarcoma of the spermatic cord: a case report].

A 63-year-old man presented with painless hard swelling of left scrotal contents. Left orchiectomy with high ligation of the spermatic cord was done with clinical diagnosis of testicular tumor. Histopathologically, this tumor was diagnosed as leiomyosarcoma, primarily, arising from the spermatic cord. After operation, prophylactic radiotherapy (60Co, 5,890 rad) was given locally. There has been neither local recurrence nor metastasis for 10 months after operation. This is the 18th case of leiomyosarcoma of the spermatic cord in Japan.

[Sipple's syndrome: a case report].

A 41-year-old woman was hospitalized for evaluation of diabetes mellitus and hypertension. The hormonal and radiological examinations revealed that she had pheochromocytoma of bilateral adrenal gland and medullary carcinoma of thyroid gland. Therefore, she was diagnosed as having Sipple's syndrome. She had no definite familial history, but her two sisters, already dead, had been strongly suspected of having had pheochromocytoma. First, bilateral adrenalectomy was performed and secondly, total thyroidectomy, excision of parathyroid and cervical lymph node dissection were performed. Histopathological diagnosis was pheochromocytoma of bilateral adrenal gland, medullary carcinoma of thyroid gland and chief cell hyperplasia of parathyroid gland. We report a case of Sipple's syndrome, which probably is the 88th case in Japan, with the review of the previous Japanese literature.

[Retroperitoneal cavernous hemangioma: a case report].

A 55-year-old man was shot at the age of 50. At that time CT revealed a mass near the spleen. Thereafter, CT did not reveal any growth of the mass, but to examine the mass in detail he was hospitalized to our department. The mass was diagnosed as left adrenal cavernous hemangioma, since, on aortography, it was typical cavernous hemangioma and fed mainly from the left inferior phrenic artery. The mass was resected with the spleen, thoracic wall, and part of diaphragma. At the operation the left adrenal gland was identified to be intact. Histopathological diagnosis was retroperitoneal cavernous hemangioma. This is the 19th case of retroperitoneal cavernous hemangioma in the Japanese literature.

[Preoperative localization of enlarged parathyroid glands by 99mTc-MIBI scintigraphy].

BACKGROUND: Recent studies have shown that 99mTc-methoxy-isobutyl-isonitrile (99mTc-MIBI), a new agent for myocardial perfusion imaging, can be successfully applied to parathyroid imaging. We evaluated the efficacy of 99mTc-MIBI scintigraphy for preoperative localization of enlarged parathyroid glands in patients with hyperparathyroidism. PATIENTS AND METHODS: From June 1994 to September 1996, 24 patients with biochemical confirmation of hyperparathyroidism were studied with 99mTc-MIBI scintigraphy prior to operation. Eleven patients had primary hyperparathyroidism (PHPT) and 13 had secondary hyperparathyroidism (SHPT) associated with chronic renal failure, including one patient with recurrent disease after subtotal parathyroidectomy. A positive 99mTc-MIBI scan for an enlarged gland was defined as an area of persistent focal uptake on the delayed image acquired at 150 min after intravenous injection of 600 MBq of 99mTc-MIBI. RESULTS: Of 11 patients with PHPT, 10, were found to have solitary parathyroid adenomas at surgery and one patient had primary hyperplasia. 99mTc-MIBI scintigraphy accurately detected 9 of 10 adenomas and 2 of 3 hyperplastic glands with no false positive results. Both of the two glands that were not detected by 99mTc-MIBI weighed 200 mg. The mean weight of the 11 glands that were visualized was 1264 mg (range 300 approximately 4300 mg). The sensitivity and predictive value positive for PHPT were 84.6% and 100%, respectively. In 13 patients with SHPT, all of 49 parathyroid glands were identified during surgery, with 43 hyperplastic glands and 6 normal-size glands. Of 43 hyperplastic glands, 28 were detected by 99mTc-MIBI and there was significant difference between the mean weight of these 28 glands (999 mg, range 290 approximately 2630 mg) and that of the 15 nonimaged hyperplastic glands (283 mg, range 90 approximately 540 mg). None of the six normal glands were imaged with 99mTc-MIBI. One patient had a false positive scan caused by a thyroid nodule. The sensitivity and predictive value positive for SHPT were 65.1% and 96.6%, respectively. CONCLUSION: 99mTc-MIBI scintigraphy is an excellent imaging method for localization of enlarged parathyroid glands in patients with hyperparathyroidism, especially with PHPT. However, it has the difficulty to demonstrate enlarged glands smaller than 300 mg in weight.

Antitumor effect of irinotecan hydrochloride (CPT-11) on human renal tumors heterotransplanted in nude mice.

BACKGROUND: There has been a paucity of antitumor drugs that are active against renal tumors. Irinotecan hydrochloride (CPT-11), a DNA topoisomerase type 1 inhibitor, has demonstrated antitumor activity against human tumors, however, no antitumor effect of CPT-11 on renal tumors has been reported. The antitumor effect of CPT-11 was investigated on 2 human renal tumors (OUR-10 and OUR-20) heterotransplanted into nude mice. METHODS: Tumor-bearing nude mice were given daily intraperitoneal injections of multiple anticancer drugs suspended in 0.2 mL of phosphate-buffered saline (PBS) 3 times at 3-day intervals. Control mice were injected with 0.2 mL of PBS. The antitumor effects were evaluated by calculating the T/C ratio (treated tumors/controls) of the tumor volume. RESULTS: Among the 10 anticancer drugs tested, 50 mg/kg of CPT-11 showed an active antitumor effect on OUR-20 (T/C ratio 34). However, all drugs tested on OUR-10 failed to show antitumor activity. CONCLUSION: Since CPT-11 was effective in 1 of 2 renal tumors examined without severe toxicity, this drug could be a candidate for chemotherapy of renal cell carcinoma.

Soluble Fas in serum from patients with renal cell carcinoma.

OBJECTIVES: Fas/APO- 1 is an apoptosis-signaling cell-surface receptor belonging to the tumor necrosis factor receptor family. The Fas-Fas ligand system plays an important role in cytotoxic T-lymphocyte-mediated or natural killer cell-mediated cytotoxicity against tumor cells. Soluble Fas (sFas), generated by alternative splicing, has been reported to antagonize the interaction of cell-surface Fas with Fas ligand. This study examined the level of sFas in the serum of patients with renal cell carcinoma (RCC) and investigated the correlation between the sFas level and clinicopathologic parameters of RCC. METHODS: Using reverse transcriptase-polymerase chain reaction, we examined the production of sFas messenger RNA (mRNA) from the cultured human RCC cell lines ACHN and OUR-10 and from surgical specimens. We also measured sFas levels in the serum of 31 patients with RCC before and after nephrectomy using an sFas-specific enzyme-linked immunosorbent assay. RESULTS: mRNA of sFas was identified both in cultured ACHN cells and human RCC tissues, although mRNA of wild-type Fas was exclusively predominant. The level of sFas in the serum of patients with RCC was significantly higher than that of normal controls, but sFas was not detectable in the supernatant of cultured renal cancer cells. Preoperative and postoperative serum sFas levels did not clearly correlate with the patients' age or sex or with histologic stage, grade, or cell type of RCC. The serum sFas level in patients with RCC correlated with tumor size. In 24 of the 31 cases, radical nephrectomy reduced the serum sFas level within 3 months. CONCLUSIONS: Our results suggest that the elevated serum sFas level in patients with RCC might not be derived from the tumor itself but might reflect an immune response to the tumor burden. Serum sFas may be a useful indicator of tumor burden in patients with RCC.

The expression of gicerin, a cell adhesion molecule, in regenerating process of collecting ducts and ureters of the chicken kidney following infection with a nephrotropic strain of infectious bronchitis virus.

Gicerin is a novel cell adhesion molecule belonging to the immunoglobulin super-family. In this study, we examined the relationship between the expression of gicerin, and the regenerating process of collecting ducts and ureters of chickens with interstitial nephritis caused by a nephrotropic strain of infectious bronchitis virus (IBV). Immunohistochemical analysis showed that gicerin expression was found on the epithelial cells of collecting ducts and ureters in the embryonic kidneys, but was undetected in these regions following hatching. In the IBV-infected kidneys, gicerin was undetected in the degenerative epithelia of collecting ducts and ureters during the acute stage of infection, but became strongly re-expressed in these regions in the regenerating stage, and gicerin expression then became undetectable in the completely repaired epithelia. These findings suggest that gicerin expression is strictly regulated for use in the epithelial regeneration, as well as development of collecting ducts and ureters of chicken.

Involvement of gicerin, a cell adhesion molecule, in tracheal development and regeneration.

Gicerin is a novel cell adhesion protein that belongs to the immunoglobulin superfamily. Gicerin protein adheres to neurite outgrowth factor, an extracellular matrix protein in the laminin family, and also exhibits homophilic adhesion. In the present study, we investigated the involvement of gicerin and neurite outgrowth factor in tracheal development and regeneration. In an early embryonic stage, gicerin protein was highly expressed in tracheal epithelial cells, but not in loosely arranged mesenchymal cells. During development, mesenchymal cells become condensed around the tracheal epithelium and then differentiate into muscle and cartilage; high levels of gicerin expression were observed in these cells. In the later embryonic and posthatching stages, no gicerin expression was detected in tracheal epithelium or cartilage. In addition, expression of gicerin increased transiently in the tracheal epithelium during the regeneration after tracheitis induced by the infectious bronchitis virus. Furthermore, a polyclonal antibody against gicerin inhibited the epithelial regeneration in tracheal organ cultures. These findings suggest that glcerin plays an important role in both tracheal development and regeneration.

Purification and characterization of three MEKA-like proteins in liver: association of a 94 kDa protein with beta gamma subunits of G-proteins.

Retinal 32 kDa MEKA protein (rMEKA) exists in the photoreceptor cells and forms a complex with beta gamma subunit of transducin. Bovine liver contained three MEKA-like proteins (94 kDa, 35 kDa-a, 35 kDa-b) which reacted with a rMEKA antibody. Each protein was purified as a single band on a SDS-PAGE and used for a reconstitution experiment with alpha and beta gamma subunits of cerebral G-proteins (Go/i). The 94 kDa protein inhibited GTP-binding ability of G alpha by forming a complex with beta gamma subunit.

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 degrees 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 of gicerin in development, oncogenesis and regeneration of the chick kidney.

Neurite outgrowth factor, which promotes neurite extension from neuronal cells, is an extracellular matrix glycoprotein belonging to the laminin family. Gicerin is a protein that binds neurite outgrowth factor. Its cDNA cloning has revealed that it is a novel cell adhesion molecule belonging to the immunoglobulin super-family. Functional analysis demonstrates that gicerin possesses homophilic binding activity as well as heterophilic binding activity with neurite outgrowth factor. We examined the role and expression of neurite outgrowth factor and gicerin in chick kidney during development. In the embryonic kidney, gicerin was found to be highly expressed both on ureteric bud cells and metanephrogenic mesenchymal cells, when the mesenchymal cells become condensed to be converted into polarized epithelial cells. In the adult kidney, the expression of gicerin was decreased and restricted to the glomerulus, proximal tubule and medullary loop. On the other hand, neurite outgrowth factor was constitutively expressed in the basement membranes of tubules and the matrices of glomeruli during development. As some molecules which are expressed during embryogenesis and suppressed after maturation are re-expressed in tumor cells or tissues during regeneration, we also examined the expression of gicerin in chicken Wilms' tumor and regenerating kidney in interstitial nephritis. Gicerin was remarkably upregulated in Wilms' tumor and re-expressed in collecting ducts recovering from interstitial nephritis. These findings suggest that gicerin could play a role not only in normal renal development but also in oncogenesis and regeneration.

Low doses of oral dexamethasone for hormone-refractory prostate carcinoma.

BACKGROUND: Although glucocorticoids have been used to treat patients with hormone-refractory prostate carcinoma (HRPC), reports have varied regarding the types and doses of glucocorticoids used as well as their clinical benefits. In the current study, low doses of dexamethasone were investigated for their specific beneficial effects and the feasibility of long term treatment. METHODS: Thirty-seven patients diagnosed with HRPC were treated with oral dexamethasone (0.5-2 mg/day). The patients ranged in age from 53-89 years (median, 74 years). Thirty-two patients, including 6 with lymph node metastases, had bone involvement whereas only 5 patients were found to have elevated serum prostate specific antigen (PSA) levels. RESULTS: Twenty-three patients (62%) who received no other concomitant therapy demonstrated a decline in their serum PSA level of > or = 50%, which was confirmed by a second PSA value obtained > or = 4 weeks later. The median time to PSA progression was 9 months. Among 18 patients with bone pain, 11 (61%) had improvement and in 5 patients (28%) the pain became stable. Among 21 patients with interpretable bone scans, 4 (19%) showed improvement and 8 (38%) achieved stable disease. Both symptomatic and objective responses of bone metastases were correlated with declines in the serum PSA level of > or = 50%. Ten patients achieved an increase in their hemoglobin level of at least 2 g/dL. Patients whose PSA level declined by > or = 50% with therapy had significantly prolonged survival (median, 22 months). As pretreatment markers, a longer interval before the initial evidence of disease progression appeared was found to correlate significantly with posttherapy PSA declines of > or = 75%. All side effects of the glucocorticoids were reported to be mild. CONCLUSIONS: Low doses of dexamethasone were found to be beneficial in the treatment of HRPC, decreasing the severity of anemia and osseous disease as well as reducing serum PSA levels. A posttherapy serum PSA decline of > or = 50% appears to be a reliable marker of improved survival with this therapy.

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.

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

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.

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.