Ral GTPase Activation by Downregulation of RalGAP Enhances Oral Squamous Cell Carcinoma Progression.

Ral small GTPases, consisting of RalA and RalB, are members of the Ras family. Their activity is upregulated by RalGEFs. Since several RalGEFs are downstream effectors of Ras, Ral is activated by the oncogenic mutant Ras. Ral is negatively regulated by RalGAP complexes that consist of a catalytic α1 or α2 subunit and its common partner ß subunit and similarly regulate the activity of RalA as well as RalB in vitro. Ral plays an important role in the formation and progression of pancreatic and lung cancers. However, the involvement of Ral in oral squamous cell carcinoma (OSCC) is unclear. In this study, we investigated OSCC by focusing on Ral. OSCC cell lines with high Ral activation exhibited higher motility. We showed that knockdown of RalGAPß increased the activation level of RalA and promoted the migration and invasion of HSC-2 OSCC cells in vitro. In contrast, overexpression of wild-type RalGAPα2 in TSU OSCC cells attenuated the activation level of RalA and inhibited cell migration and invasion. Real-time quantitative polymerase chain reaction analysis of samples from patients with OSCC showed that RalGAPα2 was downregulated in oral cancer tissues as compared with normal epithelia. Among patients with OSCC, those with a lower expression of RalGAPα2 showed a worse overall survival rate. A comparison of DNA methylation and histone modifications of the RalGAPα2 gene in OSCC cell lines suggested that crosstalk among DNA methylation, histone H4Ac, and H3K27me2 was involved in the downregulation of RalGAPα2. Thus, activation of Ral GTPase by downregulation of RalGAP expression via a potential epigenetic mechanism may enhance OSCC progression.

Downregulation of Ral GTPase-activating protein promotes tumor invasion and metastasis of bladder cancer.

The small GTPase Ral is known to be highly activated in several human cancers, such as bladder, colon and pancreas cancers. It is reported that activated Ral is involved in cell proliferation, migration and metastasis of bladder cancer. This protein is activated by Ral guanine nucleotide exchange factors (RalGEFs) and inactivated by Ral GTPase-activating proteins (RalGAPs), the latter of which consist of heterodimers containing a catalytic α1 or α2 subunit and a common ß subunit. In Ras-driven cancers, such as pancreas and colon cancers, constitutively active Ras mutant activates Ral through interaction with RalGEFs, which contain the Ras association domain. However, little is known with regard to the mechanism that governs aberrant activation of Ral in bladder cancer, in which Ras mutations are relatively infrequent. Here, we show that Ral was highly activated in invasive bladder cancer cells due to reduced expression of RalGAPα2, the dominant catalytic subunit in bladder, rather than increased expression of RalGEFs. Exogenous expression of wild-type RalGAPα2 in KU7 bladder cancer cells with invasive phenotype, but not mutant RalGAPα2-N1742K lacking RalGAP activity, resulted in attenuated cell migration in vitro and lung metastasis in vivo. Furthermore, genetic ablation of Ralgapa2 promoted tumor invasion in a chemically-induced murine bladder cancer model. Importantly, immunohistochemical analysis of human bladder cancer specimens revealed that lower expression of RalGAPα2 was associated with advanced clinical stage and poor survival of patients. Collectively, these results are highly indicative that attenuated expression of RalGAPα2 leads to disease progression of bladder cancer through enhancement of Ral activity.

Production of active MMP7 in E. coli and its application for metalloproteinase inhibitors screening.

MMP-7 is the smallest metalloproteinase. Its unregulated activities and existence in serum are recently known to be tightly related with life-threatening disease such as cardiac disease and several cancers. The protein production is thought to be useful for its characterization and antibody generation. Although many attempts at bacterial expressions have been conducted, they were recovered as insoluble and inactive protein. In this study, after soluble expression, single-step purification and conversion to active protease, it was applied for the screening secretory metalloproteinase inhibitors in conditioned media of human cancer cells.

Identification of protein kinase Calpha as an essential, but not sufficient, cytosolic factor for Ca2+-induced alpha- and dense-core granule secretion in platelets.

Upon activation, platelets release many active substances. Here, we have analyzed the mechanism governing Ca(2+)-induced secretion of von Willebrand factor stored in alpha-granules and 5-hydroxytryptamine in dense-core granules in permeabilized human platelets. Both secretions were dependent on ATP and cytosol. An essential factor for both granule secretions was purified from rat brain cytosol and identified to be protein kinase Calpha (PKCalpha) by partial amino acid sequencing. Purified PKCalpha efficiently stimulated both secretions in the presence of cytosol, whereas PKCalpha alone did not support the secretion of either type of granules, suggesting that PKCalpha is not a sufficient factor. Finally, in human platelet cytosol fractionated by a gel filtration column, the stimulatory activity for dense-core granule secretion paralleled with the concentration of PKC, suggesting that PKC could also be such a stimulatory factor in platelet cytosol. Thus, we identified PKCalpha as an essential, but not sufficient, cytosolic factor for the Ca(2+)-induced secretions of both alpha- and dense-core granules in platelets.

Small GTPase Rho regulates thrombin-induced platelet aggregation.

Platelets play essential roles in hemostasis and thrombosis by aggregating with each other. However, the molecular mechanism governing platelet aggregation is not yet fully understood. Here, we established an assay system using platelets permeabilized with streptolysin-O to analyze mechanism of the thrombin-induced aggregation, focusing upon a controversial issue in the field whether small GTPase Rho regulates the aggregation. Incubation of the permeabilized platelets with Rho GDP-dissociation inhibitor, an inhibitory regulator for Rho family GTPases, extracted Rho family proteins extensively from the plasma and intracellular membranes, and inhibited the thrombin-induced aggregation. Incubation of the permeabilized platelets with botulinum exoenzyme C3, which specifically inhibits Rho function by ADP-ribosylating it, abolished the thrombin-induced aggregation. Thus, Rho is involved in thrombin-induced aggregation of platelets.

Molecular dissection of alpha- and dense-core granule secretion of platelets.

Upon activation, platelets release many active substances stored in alpha- and dense-core granules. However, the molecular mechanisms governing the regulated exocytosis are not yet fully understood. We have established an assay system using streptolysin-O-permeabilized platelets to analyze the Ca2+-induced secretions of von Willebrand factor stored in alpha-granules and [3H]5-hydroxytryptamine (5-HT) in dense-core granules. Using the assay, we found that small GTPase Rab4 regulates alpha-, but not dense-core, granule secretion in platelets. Furthermore, we purified a cytosolic essential protein and currently are analyzing its function.

Small GTPase Rab4 regulates Ca2+-induced alpha-granule secretion in platelets.

Upon activation, platelets release many active substances stored in alpha- and dense-core granules. However, the molecular mechanisms governing regulated exocytosis are not yet fully understood. Here, we have established an assay system using permeabilized platelets to analyze the Ca(2+)-induced exocytosis of both types of granules, focusing on RabGTPases. Incubation with Rab GDP dissociation inhibitor, an inhibitory regulator of RabGTPases, reduced membrane-bound RabGTPases extensively, and caused strong inhibition of the Ca(2+)-induced secretion of von Willebrand factor (vWF) stored in alpha-granules, but not that of [(3)H]5-hydroxytryptamine (5-HT) in dense-core granules. Specifically, Rab4 co-fractionated with vWF and P-selectin (an alpha-granule marker) upon separation of platelet organelles by density gradient centrifugation. Incubation of the permeabilized platelets with cell extracts expressing the dominant negative mutant of His-tagged Rab4S22N, but not with those of similar mutant His-Rab3BT36N, inhibited the vWF secretion, whereas neither of the cell extracts affected the [(3)H]5-HT secretion. Importantly, the inhibition of vWF secretion was rescued by depleting the cell extracts of the His-Rab4S22N with nickel beads. Thus, in platelets, the regulatory mechanisms governing alpha- and dense-core granule secretions are distinct, and Rab4 is an essential regulator of the Ca(2+)-induced exocytosis of alpha-granules.

Squamous cell carcinoma of the external auditory canal: two cases treated with high dose rate 192Ir remote afterloading system (RALS).

We report two cases of early-stage external auditory canal cancer treated by intracavitary irradiation with a high dose rate (HDR) 192Ir remote afterloading system (RALS) for preoperative treatment. A 6-Fr catheter for the HDR 192Ir remote afterloader, fixed by a plastic earplug, was inserted into the external auditory canal in two cases (case 1, T2N0M0; case 2, T1N0M0). The total intracavitary radiation dosages were 50 Gy (10 Gy/2 Fr/wk for 5 wks) for case 1, and 42 Gy (15 Gy/5 Fr/wk for 3 wks) for case 2. No external irradiation was given in either case. Surgical resection was performed in both cases, three to four weeks after irradiation. Histopathological examination confirmed the post-irradiation changes of necrosis, hyalinosis, and calcification, although vivid cancer cells remained. In preoperative irradiation of external auditory cancer, this method, although limited to treating early-stage cancers, may be a modality of choice for its efficacy and less severe side effects.

[Reproductive and developmental toxicity study of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na (1). Fertility study in rats].

Fertility study of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na), a novel neutrophil elastase inhibitor, was conducted in Sprague-Dawley (SD) rats. ONO-5046.Na was administered intravenously at doses of 18.75, 37.5 and 75 mg/kg/day to male rats from 64 prior to mating, through the mating period and until necropsy, and to female rats from 15 days prior to mating until Day 7 of gestation, in order to examine its effects on fertility and reproductive performance of males and females and the development of their fetuses. There were no changes attributable to ONO-5046.Na in general signs, body weight, food consumption or autopsy findings in males and females. No drug-related changes were observed in estrous cycles, copulation and fertility indices in males and females. Pituitary weight of dams was decreased in each of the ONO-5046.Na treated groups, but no histopathological changes were observed in the pituitary. In the cesarean section findings in dams, ONO-5046.Na had no effects on the number of corpola lutea, the number of live fetuses, the implantation ratio, the resorbed and dead fetus ratio, fetal or placental weight, or the incidences of external, skeletal or visceral anomalies of the fetuses. From these results, it is considered that the NOAEL of ONO-5046.Na is 75 mg/kg/day for general and reproductive toxicity in males and females and for developmental toxicity in their fetuses.

[Reproductive and developmental toxicity study of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na) (2). Study for effects on pre- and postnatal development in rats, including maternal function].

Prenatal and postnatal toxicity of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na), a novel inhibitor of human neutrophil elastase, was studied in Sprague-Dawley (SD) rats. ONO-5046.Na was injected intravenously at doses of 0, 18.75, 37.5 and 75 mg/kg/day to pregnant rats from day 7 of pregnancy to day 20 after delivery. All pregnant rats were allowed to deliver naturally for postnatal examination of their offspring. No adverse effects on dams were observed in clinical signs, body weight change, food consumption, pregnant, delivery or lactating performances. ONO-5046.Na did not affect the postnatal development of offspring, including birth index, survival index, physical and functional development, motor activity, emotionality, learning ability and reproductive performance. From these results, it is considered that the NOAEL of ONO-5046.Na is 75 mg/kg/day for dams and their offspring.

[Reproductive and developmental toxicity study of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na) (3). Teratogenicity study in rabbits].

Teratogenicity of sodium N[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino]benzoyl] aminoacetate tetrahydrate (ONO-5046.Na), a novel inhibitor of human neutrophil elastase, was studied. ONO-5046.Na was injected intravenously at doses of 0, 7.5, 15 and 30 mg/kg/day to pregnant Kbl: NZW rabbits from day 6 to day 18 of pregnancy. All female rabbits were sacrificed on day 29 of pregnancy and their fetuses were examined. There were no clinical signs or death attributable to ONO-5046.Na. One dam in the control group and 3 dams in the 30 mg/kg/day group aborted. Body weight gain in the 15 and 20 mg/kg/day groups and food intake in the 30 mg/kg/day group were decreased during the administration period. These changes had recovered by the end of the study. Kidney weight was increased in the 30 mg/kg/day group. There were no effects of ONO-5046.Na in necropsy findings at cesarean section in dams at any dose levels. Developmental toxicity of ONO-5046.Na was not found at any dose levels. From these results, it is considered that the NOAEL of ONO-5046.Na is 7.5 mg/kg/day for pregnant animals and 30 mg/kg/day for fetuses.

Relationship of serum testosterone level with proliferating cell nuclear antigen and nm23 protein in human prostatic carcinoma tissue.

OBJECTIVE: To elucidate the biological significance of proliferating cell nuclear antigen (PCNA) and nm23 immunoreactivity in prostatic carcinoma (PC) tissue, both expressions were immunohistochemically analyzed, and the results were compared with the change of the serum testosterone (T) level. METHODS: The paraffin-embedded materials obtained from 49 untreated PC and 16 hormonally refractory PC (hr-PC) were used. Of the 49 untreated PC, 35 received luteinizing hormone-releasing hormone (LH-RH) analogue treatment, while 14 received a cisplatin-based chemotherapy. The immunohistochemistry of PCNA and nm23 protein was performed using an anti-PCNA monoclonal antibody (PC-10) and an antihuman nm23 polyclonal antibody (OA-11-890), respectively. The serum T level was measured by means of radioimmunoassay. RESULTS: In both untreated PC and hr-PC, the immunoreactivity of nm23 protein significantly correlated with the PCNA expression. Both PCNA expression and nm23 protein immunoreactivity were higher in poorly differentiated PC than those observed in well-differentiated PC, while no significant difference in the serum T level was observed between poorly and well-differentiated PCs. On the other hand, both PCNA expression and nm23 protein immunoreactivity were significantly higher in hr-PC than those observed in untreated PC, whereas the serum T level was significantly lower in hr-PC. In 35 PCs treated with LH-RH analogue, no significant difference in both PCNA expression and nm23 protein immunoreactivity was found between those specimens obtained before and at 3 months after the treatment, while a significant reduction of the serum T level was noted at 3 months after the treatment. Similarly, in 14 PCs treated with a cisplatin-based chemotherapy, the same change of PCNA expression and nm23 protein immunoreactivity as observed in LH-RH analogue treatment was found, while no significant difference of the serum T level was found. CONCLUSIONS: These findings appear to indicate that (1) nm23 protein immunoreactivity is interrelated with cellular proliferation in PC tissue and (2) alteration of the serum T level during a short period was not enough to explain the essential change of cellular proliferation of PC tissue, but might reflect other aspects of tumor growth such as apoptosis.

Immunohistochemical analysis of estramustine binding protein with particular reference to proliferative activity in human prostatic carcinoma.

BACKGROUND: The estramustine binding protein (EMBP) specifically binds to estramustine and was first discovered in the rat ventral prostate. However, the physiological property of EMBP in the human prostate still remains to be elucidated. To elucidate whether EMBP is interrelated with cellular proliferation in human prostatic carcinoma (PC), the change in EMBP immunostaining during luteinizing hormone-releasing hormone (LH-RH) analog administration or during Cis-platinum-based chemotherapy, and the difference in EMBP immunostaining between hormone refractory (hr-PC) and untreated PC were analyzed. METHODS: Forty-six patients with histologically proven untreated PCs (34 were treated with LH-RH analog and 12 were treated with chemotherapy as an initial therapy) and 14 with hr-PC were used in this study. PC tissues were obtained before and 3 months after the initial therapy. The changes in immunostainings for EMBP, proliferating cell nuclear antigen (PCNA), and nm23 protein were compared with the change in serum prostate-specific antigen (PSA) level and the histological response during the treatment. RESULTS: The increased EMBP expression was observed in tumors with high histological grade and high clinical stage as well as in hr-PC. In untreated PC, EMBP expression weakly correlated with PCNA or nm23 protein immunoreactivity. In PC receiving LH-RH analog, EMBP expression was significantly reduced after treatment, however, no significant changes were observed in PCNA or nm23 protein immunoreactivity. In addition, EMBP expression before the treatment significantly correlated with the serum PSA change, while PCNA expression and nm23 protein immunoreactivity did not. On the other hand, no significant relationship was observed between histological changes induced by the LH-RH analog and immunostainings for EMBP, PCNA, and nm23 protein before treatment. In PC patients receiving chemotherapy, immunostainings for EMBP, PCNA, and nm23 protein were not significantly changed during the treatment. EMBP immunoreactivity was significantly higher in hr-PC than in untreated PC with paralleled change of PCNA expression and nm23 protein immunoreactivity. CONCLUSIONS: These observations indicate that EMBP is androgen regulated in some PCs. However, EMBP expression is demonstrated even in hr-PC and is interrelated with cellular proliferation especially in hr-PC.

[Reproductive and developmental toxicity studies of landiolol hydrochloride (ONO-1101) (2). Teratogenicity study in rats].

A teratogenicity study of landiolol hydrochloride (ONO-1101), a novel ultra short acting beta-blocker, was conducted in Sprague-Dawley (SD) rats. ONO-1101 was administered intravenously at a dose level of 0 (control), 25, 50 or 100 mg/kg/day to pregnant rats from day 7 to 17 of gestation, and effects of ONO-1101 on dams, fetuses and their offspring, were examined. In the 100 mg/kg/day group, hypoactivity, bradypnea, reddish lacrimation, clonic convulsion and loss of righting reflex were observed and 2 animals died. Food consumption in the 100 mg/kg/day group decreased during the treatment period. No drug-related changes were observed in dams for their body weights, necropsy findings or organ weights. Decrease in placental weight was seen in the 100 mg/kg/day group, but no effect was found in fetal weight. ONO-1101 had no effects on delivery and lactation. On day 4 after birth, viability of offspring were decrease in the 50 or 100 mg/kg/day group, and body weight of males were decreased in the 100 mg/kg/day group, but no change caused by the treatment was observed in growth of offspring thereafter. On skeletal examination in offsprings culled on day 4 after birth, increase in the incidence of unossificated talus were seen in the 50 or 100 mg/kg/day group. But no drug-related anomalies were observed in external, skeletal or visceral findings in fetuses. It was not also found any influence of ONO-1101 on external differentiations, functional, behavioral or learning abilities or reproductive performance in offspring. From the above results, it is estimated that the no-toxic dose level of ONO-1101 under these experimental conditions is 50 mg/kg/day for dams, and 25 mg/kg/day for their offspring.

[Reproductive and developmental toxicity studies of landiolol hydrochloride (ONO-1101) (4). Perinatal and postnatal study in rats].

A perinatal and postnatal study of landiolol hydrochloride (ONO-1101), a novel ultra short acting beta-blocker, was conducted in Sprague-Dawley(SD) rats. ONO-1101 was administered intravenously at a dose level of 0 (control), 25, 50 or 100 mg/kg/day from day 17 of gestation to day 20 after parturition to examine the effects on pregnancy, delivery, lactation and the effects on postnatal growth and development of offspring. In the 100 mg/kg/day group, hypoactivity, reddish lacrimation, clonic convulsion and bradypnea/apnea were observed after administration and 5 animals died in the treatment period, and body weight on day 21 and food consumption on day 14-21 of dam at weaning were lower than control group. In the 50 mg/kg/day group, reddish lacrimation was occasionally seen in some animals. ONO-1101 had no effects on pregnancy, delivery, lactation and necropsy findings or organ weights of dams. In the 100 mg/kg/day group, viability of offspring on day 4 after birth decreased and body weight gain of the suckling suppressed, but those changes recovered after weaning. On the skeletal examination of offspring culled on day 4 after birth, decrease in the mean number of osiffied phalanges of hindpaw and increase in the incidence of unossified talus bone were seen in the 100 mg/kg/day group, however, no delay of ossification was found form the weanling. There were no influence of ONO-1101 on external differentiation, functional, behavioral or learning abilities or reproductive performance in offspring. From the above results, it is estimated that the no-toxic dose level of ONO-1101 under these experimental conditions is 50 mg/kg/day for dam and offspring.

Cytology of Langerhans cell histiocytosis in effusions: a case report.

BACKGROUND: Langerhans cell histiocytosis is a relatively rare disorder of children, characterized by abnormal proliferation of Langerhans cells. There has been no report on the cytologic appearance of Langerhans cells in effusions. CASE: A 20-year-old had a 12-year history of the disease, since he was 8 years old. He had multiple mass lesions in the bones, lung and liver, and Langerhans cells appeared in the pleural fluid and ascites. They had indented, twisted or grooved nuclei, with a finely or coarsely granular chromatin pattern. Some of the nuclei were eccentrically located, and prominent nucleoli were occasionally seen. Immunohistochemically the cells showed positivity for S-100 protein. Electron microscopic examination revealed abortive Birbeck granules. CONCLUSION: The cytologic appearance was somewhat accentuated and different from that reported for other sites. Immunohistochemical staining for S-100 protein and/or electron microscopic examination should be employed.