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Diphenylarsinic acid (DPAA) is a non-natural pentavalent organic arsenic and was detected in well water in Kamisu, Ibaraki, Japan in 2003. Individuals that had consumed this arsenic-contaminated water developed cerebellar symptoms such as myoclonus. We previously revealed that DPAA exposure in rats in vitro and in vivo specifically affected astrocytes rather than neurons among cerebellar cells. Here, we evaluated adverse effects of DPAA in cultured normal human cerebellar astrocytes (NHA), which were compared with those in normal rat cerebellar astrocytes (NRA) exposed to DPAA at 10 μM for 96 h, focusing on aberrant activation of astrocytes; increase in cell viability, activation of MAP kinases (ERK1/2, p38MAPK, and SAPK/JNK) and transcription factors (CREB, c-Jun, and c-Fos), upregulation of oxidative stress-responsive factors (Nrf2, HO-1, and Hsp70), and also hypersecretion of brain cytokines (MCP-1, adrenomedullin, FGF-2, CXCL1, and IL-6) as reported in NRA. While DPAA exposure at 10 μM for 96 h had little effect on NHA, a higher concentration (50 μM for 96 h) and longer exposure (10 μM for 288 h) induced similar aberrant activation. Moreover, exposure to DPAA at 50 μM for 96 h or 10 μM for 288 h in NHA induced hypersecretion of cytokines induced in DPAA-exposed NRA (MCP-1, adrenomedullin, FGF-2, CXCL1, and IL-6), and IL-8 besides into culture medium. These results suggested that aberrantly activated human astrocytes by DPAA exposure might play a pivotal role in the pathogenesis of cerebellar symptoms, affecting adjacent neurons, microglia, brain blood vessels, or astrocyte itself through these brain cytokines in human.

PlexinA1 (PlxnA1) is a transmembrane receptor for semaphorins, a large family of proteins that act as axonal guidance cues during nervous system development. However, there are limited studies on PlxnA1 function in neurobehavior. The present study examined if PlxnA1 deficiency leads to behavioral abnormalities in BALB/cAJ mice. PlxnA1 knockout (KO) mice were generated by homologous recombination and compared to wild type (WT) littermates on a comprehensive battery of behavioral tests, including open field assessment of spontaneous ambulation, state anxiety, and grooming, home cage grooming, the wire hang test of muscle strength, motor coordination on the rotarod task, working memory on the Y maze alternation task, cued and contextual fear conditioning, anxiety on the elevated plus maze, sociability to intruders, and sensory processing as measured by prepulse inhibition (PPI). Measures of motor performance, working memory, fear memory, and sociability did not differ significantly between genotypes, while PlxnA1 KO mice displayed excessive self-grooming, impaired PPI, and slightly lower anxiety. These results suggest a crucial role for PlxnA1 in the development and function of brain regions controlling self-grooming and sensory gating. PlxnA1 KO mice may be a valuable model to investigate the repetitive behaviors and information processing deficits characteristic of many neurodevelopmental and psychiatric disorders.

The corpus callosum (CC) is the biggest commissure that links cerebral hemispheres. Guidepost structures develop in the cortical midline during CC development and express axon guidance molecules that instruct neurons regarding the proper direction of axonal elongation toward and across the cortical midline. Neuropilin-1 (Npn1), a high affinity receptor for class 3 semaphorins (Sema3s) localized on cingulate pioneering axons, plays a crucial role in axon guidance to the midline through interactions with Sema3s. However, it remains unclear which type of Plexin is a component of Sema3 holoreceptors with Npn1 during the guidance of cingulate pioneering axons. To address the role of PlexinA1 in CC development, we examined with immunohistochemistry the localization of PlexinA1, Npn1, and Sema3s using embryonic brains from wild-type (WT) and PlexinA1-deficient (PlexinA1 knock-out (KO)) mice with a BALB/cAJ background. The immunohistochemistry confirmed the expression of PlexinA1 in callosal axons derived from the cingulate and neocortex of the WT mice on embryonic day 17.5 (E17.5) but not in the PlexinA1 KO mice. To examine the role of PlexinA1 in the navigation of callosal axons, the extension of callosal axons toward and across the midline was traced in brains of WT and PlexinA1 KO mice at E17.5. As a result, callosal axons in the PlexinA1 KO brains had a significantly lower incidence of midline crossing at E17.5 compared with the WT brains. To further examine the role of PlexinA1 in CC development, the CC phenotype was examined in PlexinA1 KO mice at postnatal day 0.5 (P0.5). Most of the PlexinA1 KO mice at P0.5 showed agenesis of the CC. These results indicate the crucial involvement of PlexinA1 in the midline crossing of callosal axons during CC development in BALB/cAJ mice.

Diphenylarsinic acid (DPAA) was detected as the primary compound responsible for the arsenic poisoning that occurred in Kamisu, Ibaraki, Japan, where people using water from a well that was contaminated with a high level of arsenic developed neurological (mostly cerebellar) symptoms and dysregulation of regional cerebral blood flow. To understand the underlying molecular mechanism of DPAA-induced cerebellar symptoms, we focused on astrocytes, which have a brain-protective function. Incubation with 10 µM DPAA for 96 h promoted cell proliferation, increased the expression of antioxidative stress proteins (heme oxygenase-1 and heat shock protein 70), and induced the release of cytokines (MCP-1, adrenomedullin, FGF2, CXCL1, and IL-6). Furthermore, DPAA overpoweringly increased the phosphorylation of three major mitogen-activated protein kinases (MAPKs) (ERK1/2, p38MAPK, and SAPK/JNK), which indicated MAPK activation, and subsequently induced expression and/or phosphorylation of transcription factors (Nrf2, CREB, c-Jun, and c-Fos) in cultured rat cerebellar astrocytes. Structure-activity relationship analyses of DPAA and other related pentavalent organic arsenicals revealed that DPAA at 10 µM activated astrocytes most effective among organic arsenicals tested at the same dose. These results suggest that in a cerebellum exposed to DPAA, abnormal activation of the MAPK-transcription factor pathway and irregular secretion of these neuroactive, glioactive, and/or vasoactive cytokines in astrocytes can be the direct/indirect cause of functional abnormalities in surrounding neurons, glial cells, and vascular cells: This in turn might lead to the onset of cerebellar symptoms and disruption of cerebral blood flow.

The opening of the mouse vaginal cavity to the skin is a postnatal tissue remodeling process that occurs at approximately five weeks of age for the completion of female genital tract maturation at puberty. The tissue remodeling process is primarily composed of a hormonally triggered apoptotic process predominantly occurring in the epithelium of the distal section of the vaginal cavity. However, the detailed mechanism underlying the apoptotic induction remains to be elucidated. In the present study, it was observed that the majority of BALB/c mice lacking the class 4 semaphorin, semaphorin 4D (Sema4D), developed imperforate vagina and hydrometrocolpos resulting in a perpetually unopened vaginal cavity regardless of a normal estrogen level comparable with that in wild‑type (WT) mice. Administration of β‑estradiol to infant Sema4D‑deficient (Sema4D‑/‑) mice did not induce precocious vaginal opening, which was observed in WT mice subjected to the same β‑estradiol administration, excluding the possibility that the closed vaginal phenotype was due to insufficient estrogen secretion at the time of vaginal opening. In order to assess the role of Sema4D in the postnatal vaginal tissue remodeling process, the expression of Sema4D and its receptor, plexin‑B1, was examined as well as the level of apoptosis in the vaginal epithelia of five‑week‑old WT and Sema4D‑/‑ mice. Immunohistochemical analyses confirmed the localization of Sema4D and plexin‑B1 in the mouse vaginal epithelia. Terminal deoxynucleotidyl transferase dUTP nick end labeling assay and immunohistochemistry detecting activated caspase‑3 revealed significantly fewer apoptotic cells in situ in the vaginal mucosa of five‑week‑old Sema4D‑/‑ mice compared with WT mice. The addition of recombinant Sema4D to Sema4D‑/‑ vaginal epithelial cells in culture significantly enhanced apoptosis of the vaginal epithelial cells, demonstrating the apoptosis‑inducing activity of Sema4D. The experimental reduction of plexin‑B1 expression in vaginal epithelial cells demonstrated the integral role of plexin‑B1 in Sema4D‑induced apoptotic cell death. These results suggest a non‑redundant role of Sema4D in the postnatal tissue remodeling process in five‑week‑old BALB/c mice, which involves the induction of vaginal epithelial cell apoptosis through Sema4D binding to plexin‑B1.

Objective We attempted to investigate whether dehydroepiandrosterone sulfate (DHEA-S) levels are associated with remission of major depressive disorder by assessing scores on the 17-Item Structured Interview Guide for the Hamilton Depression before and after antidepressant treatment. Methods Plasma DHEA-S levels in 24 patients diagnosed with major depressive disorder on the basis of Diagnostic and Statistical Manual of Mental Disorders, fourth edition (text revision) before and after antidepressant treatment, and 24 healthy, gender-matched, and age-matched controls were measured using a radioimmunoassay kit. Results Plasma DHEA-S levels in patients were significantly higher than those in healthy controls. In patients who achieved remission after antidepressant treatment, plasma DHEA-S levels significantly declined compared with the levels before treatment. A significant correlation was observed between changes in DHEA-S levels and Absence of Depressive and Anxious Mood scores, which are calculated from the 2-Item Structured Interview Guide for the Hamilton Depression rating as follows: severity of depressive mood and anxiety in patients before and after antidepressant treatment. Conclusions These findings suggest that plasma DHEA-S levels can be used as a putative indicator of the state of remission in patients with major depressive disorder. Copyright © 2014 John Wiley & Sons, Ltd.

Recent investigations have suggested that semaphorins, which are known repulsive axon guidance molecules, may play a crucial role in maintaining brain homeostasis by regulating microglial activity. Sema3A, secreted in higher amounts from injured neurons, is considered to suppress excessive inflammatory responses by inducing microglial apoptosis through its binding to Plexin-A1 receptors on activated microglia. To clarify the in vivo role of Plexin-A1-mediated signaling in lipopolysaccharide (LPS)-induced injury in mouse brain, we examined the neuroinflammatory changes initiated by LPS administration to the cerebral ventricles of wild-type (WT) and Plexin-A1-deficient (−/−) mice. WT mice administered LPS exhibited a significantly higher expression of COX-2, iNOS, IL-1β and TNF-α in the hippocampus, and a significantly greater ventricular enlargement and intracerebral infiltration of leukocytes, as compared with the saline-treated group. By contrast, Plexin-A1−/− mice administered LPS did not exhibit a significantly increased expression of COX-2, iNOS, IL-1β or TNF-α in the hippocampus as compared with the saline-treated group. Plexin-A1−/− mice administered LPS did not show significant increases in ventricle size or infiltration of leukocytes into the brain, as compared with the saline-treated group. In WT, but not in the Plexin-A1−/− primary microglia treated with LPS, Sema3A induced significantly more nitric oxide production than in the immunoglobulin G control. These results revealed the crucial role of the Sema3A-Plexin-A1 interaction in the Toll-like receptor 4-mediated signaling of the LPS-induced activation of microglia. Thus, results of the present study revealed the essential role of Plexin-A1 in the development of LPS-induced neuroinflammation in mice, suggesting the possible application of microglial control of the semaphorin-plexin signaling system to the treatment of LPS-induced encephalopathy and other psychiatric diseases associated with neuroinflammation.

Using seven monoclonal SN38-resistant subclones established from ME180 human cervical squamous cell carcinoma cells, we examined the demethylation effects of 5-aza-2'-deoxycytidine (5-aza-CdR) on the SN38-sensitivity of the cells as well as the expression of death-associated protein kinase (DAPK) in the SN38-resistant cells. The DAPK expression levels were evaluated among parent ME180 cells, SN38-resistant ME180 cells and cisplatin-resistant ME180 cells by methylation-specific DAPK-PCR, quantitative RT-PCR and western blot analysis. The SN38-resistant cells co-treated with SN38 and 5-aza-CdR strongly exhibited enhanced SN38-sensitivities resembling those found in the parent cells. In the SN38-resistant subclones, no relationships were found between the restored SN38 sensitivity and hypermethylation of the DAPK promoter, DAPK mRNA expression, DAPK protein expression and induction of DAPK protein after 5-aza-CdR treatment, unlike the strong suppression of 5-aza-CdR-induced DAPK protein expression in the cisplatin-resistant subclones. These findings indicate that reversibly methylated molecules, but not DAPK, may regulate SN38 resistance, and that demethylating agents can be strong sensitizing anticancer chemotherapeutic drugs for SN38-resistant cancers.

Contexte: Sema4D/CD100 est un type de semaphorine de classe 4 qui joue des roles cruciaux dans le guidage des cones de croissance dans les neurones en developpement. Sema4D est largement exprime dans tout le systeme nerveux central de l'embryon chez la souris et il est localise selectivement aux oligodendrocytes et a la myeline du cerveau apres la naissance. Cependant, il n'y a pas de preuve directe de l'implication de Sema4D dans le developpement du reseau neuronal qui est crucial pour le fonctionnement neurocomportemental. Dans cette etude, nous avons examine si un deficit en Sema4D entraine un developpement comportemental anormal. Methodes: Des souris de phenotype sauvage et des souris deficientes en Sema4D ont ete soumises a des analyses comportementales, dont le test du champ ouvert, de l'adhesive tape removal, du rotarod et du labyrinthe aqueux. Resultats: Les tests de champ ouvert ont montre que les souris ayant un deficit en Sema4D avaient une activite locomotrice accrue et passaient un pourcentage moindre du temps dans le centre du champ. Dans les tests de l'adhesive tape removal et du rotarod, qui evaluent la coordination motrice et l'equilibre, les souris ayant un deficit en Sema4D ont presente une performance significativement superieure, ce qui est en faveur d'un comportement moteur facilite. Les souris ayant un deficit en Sema4D et les souris de type sauvage ont appris avec succes la tâche du labyrinthe aqueux qui consistait a localiser une plate-forme de sauvetage dissimulee et ont egalement fait preuve d'une memoire precise de la position de la plate-forme lorsque le test etait repete apres avoir retire la plate-forme. De plus, la vitesse de nage des souris ayant un deficit en Sema4D etait significativement superieure a cette des souris de type sauvage, ce qui est en faveur d'un comportement moteur accelere. Couclusion: Nos analyses comportementales chez la souris ont demontre que les souris ayant un deficit en Sema4D ont une activite motrice accrue, ce qui est en faveur du role crucial que joue Sema4D dans le processus de developpement nerveux des structures centrales, soit un role facilitant sur le comportement moteur chez la souris.

Semaphorins and their receptors have diverse functions in axon guidance, organogenesis, vascularization and/or angiogenesis, oncogenesis and regulation of immune responses1,2,3,4,5,6,7,8,9,10,11. The primary receptors for semaphorins are members of the plexin family2,12,13,14. In particular, plexin-A1, together with ligand-binding neuropilins, transduces repulsive axon guidance signals for soluble class III semaphorins15, whereas plexin-A1 has multiple functions in chick cardiogenesis as a receptor for the transmembrane semaphorin, Sema6D, independent of neuropilins16. Additionally, plexin-A1 has been implicated in dendritic cell function in the immune system17. However, the role of plexin-A1 in vivo, and the mechanisms underlying its pleiotropic functions, remain unclear. Here, we generated plexin-A1-deficient (plexin-A1−/−) mice and identified its important roles, not only in immune responses, but also in bone homeostasis. Furthermore, we show that plexin-A1 associates with the triggering receptor expressed on myeloid cells-2 (Trem-2), linking semaphorin-signalling to the immuno-receptor tyrosine-based activation motif (ITAM)-bearing adaptor protein, DAP12. These findings reveal an unexpected role for plexin-A1 and present a novel signalling mechanism for exerting the pleiotropic functions of semaphorins.

Tail DNA genotyping of fetal and neonatal mice from C/EBPbeta heterozygous parents was performed to determine whether the decreased number of surviving C/EBPbeta mutants was caused by prenatal or postnatal death. Eighty-four 3-week-old mice born of heterozygous parents had significantly lower numbers of C/EBPbeta-deficient offspring than the expected Mendelian ratio (29.8%+/+, 65.5%+/-, 4.76%-/-, P0.05). The genotypes of 72 fetal mice from intercrossed heterozygotes showed approximately the expected 1:2:1 Mendelian ratio (18.1% +/+, 52.8% +/-, 29.2% -/-, P0.05). No difference in the proportions by sex could be detected in these perinates. This data indicates that C/EBPbeta-deficient mice have unknown lethal problems between the embryonic stage and weaning.

Attempts at protein transduction into specific restricted brain areas have remained unsuccessful. We attempted targeted, direct in vivo protein transduction by microinjecting beta-galactosidase (beta-gal) with hemagglutinating virus of Japan envelope (HVJ-E) vector into the rat nucleus tractus solitarius (NTS). The medulla oblongata including the NTS was removed 6h post-injection and cryostat sections were histochemically stained to detect beta-gal enzymatic activity. beta-gal-positive cells were present in these sections as was beta-gal activity determined by colorimetric analysis. beta-gal-positive cells were not present in the rats microinjected only beta-gal protein without HVJ-E vector. Our findings suggest that direct in vivo protein transduction into specific restricted brain areas is possible. The type of targeted delivery system we present may have wide applications in the administration of therapeutic proteins to the central nervous system.

SummaryThe class IV semaphorin Sema4A provides a costimulatory signal to T cells. To investigate the possible developmental and regulatory roles of Sema4A in vivo, we generated Sema4A-deficient mice. Although Sema4A-deficient mice develop normally, DCs and T cells from knockout mice display poor allostimulatory activities and T helper cell (Th) differentiation, respectively. Interestingly, in addition to its expression on DCs, Sema4A is upregulated on Th1-differentiating cells, and it is necessary for in vitro Th1 differentiation and T-bet expression. Consequently, in vivo antigen-specific T cell priming and antibody responses against T cell-dependent antigens are impaired in the mutant mice. Additionally, Sema4A-deficient mice exhibit defective Th1 responses. Furthermore, reconstitution studies with antigen-pulsed DCs reveal that DC-derived Sema4A is important for T cell priming, while T cell-derived Sema4A is involved in developing Th1 responses. Collectively, these results indicate a nonredundant role of Sema4A not only in T cell priming, but also in the regulation of Th1/Th2 responses.

Ghrelin is a gut-brain peptide and its endocrine activities are mediated by GH secretagogue receptor (GHSR)-1a. Des-acyl ghrelin does not activate GHSR-1a and is devoid of endocrine activities. While the microinjection of ghrelin into rat nucleus tractus solitarii (NTS) elicited hypotensive effects, this was not the case upon injection into GHSR-expressing rostral ventrolateral medulla or caudal ventrolateral medulla. To make clear the reason of the discrepancy between receptor distribution and neuronal responses, we examined the cardiovascular response of rats microinjected with des-acyl ghrelin into NTS. Intra-NTS injection of des-acyl ghrelin significantly reduced mean arterial pressure and heart rate. The hypotensive and bradycardic activity evoked by des-acyl ghrelin was not significantly different from that of native ghrelin. These results suggest that des-acyl ghrelin contribute to the regulation of cardiovascular control and that a receptor other than GHSR-1a exists in NTS.

Death-associated protein kinase (DAPK) is a calcium/calmodulin-dependent serine/threonine kinase localized to renal tubular epithelial cells. To elucidate the contribution of DAPK activity to apoptosis in renal ischemia-reperfusion (IR) injury, wild-type (WT) mice and DAPK-mutant mice, which express a DAPK deletion mutant that lacks a portion of the kinase domain, were subjected to renal pedicle clamping and reperfusion. After IR, DAPK activity was elevated in WT kidneys but not in mutant kidneys (1785.7 +/- 54.1 pmol/min/mg versus 160.7 +/- 60.6 pmol/min/mg). Furthermore, there were more TUNEL-positive nuclei and activated caspase 3-positive cells in WT kidneys than in mutant kidneys after IR (24.0 +/- 5.9 nuclei or 9.4 +/- 0.6 cells per high-power field [HPF] versus 6.3 +/- 2.2 nuclei or 4.4 +/- 0.7 cells/HPF at 40 h after ischemia). In addition, the increase in p53-positive tubule cells after IR was greater in WT kidney than in mutant kidneys (9.9 +/- 1.4 cells/HPF versus 0.8 +/- 0.4 cells/HPF), which is consistent with the theory that DAPK activity stabilizes p53 protein. Finally, serum creatinine levels after IR were higher in WT mice than in mutant mice (2.54 +/- 0.34 mg/dl versus 0.87 +/- 0.24 mg/dl at 40 h after ischemia). Thus, these results indicate that deletion of the kinase domain from DAPK molecule can attenuate tubular cell apoptosis and renal dysfunction after IR injury.

Neuromedin U (NMU) is a brain-gut peptide with potent contractile effects on the uterus and smooth muscle. Intracerebroventricular injection of NMU reportedly decreased food intake and body-weight gain in the rat. We evaluated the effects of NMU delivered by microinjection into the rat nucleus tractus solitarius (NTS) on cardiovascular responses. At the concentrations used (5, 10 or 50 pmol), the intra-NTS injection of NMU in artificial cerebrospinal fluid produced a significant reduction in both the mean arterial pressure and heart rate. The hypotensive responses were dose dependent. Our findings suggest that NMU may act as a neurotransmitter or neuromodulative substance that causes excitation of neurons in the NTS and that it may play a role in cardiovascular regulation in vivo.

A new mutant, the Wakayama epileptic rat (WER), exhibiting both spontaneous absence-like behavior and tonic-clonic convulsions, was identified in a colony of Wistar rats. To determine clear seizure characteristics of this mutant strain, we analyzed the mode of inheritance of the convulsion and observed patterns of electroencephalogram (EEG) during the seizures. F1 progeny were produced between the founder male and normal females of the same colony. Animals were monitored through the inbreeding course to analyze genetic control of epileptic behavior. EEGs were recorded using affected animals in the F3-4 and post F13 generations. After the F2 generation, affected rats spontaneously exhibited both absence-like immobile behavior and tonic-clonic convulsions. The absence-like seizures were characterized by motor arrest and head droop. The tonic-clonic convulsions began with neck and forelimb clonus, wild jumping/running, and opisthotonic posturing, and evolved to tonic, then clonic convulsions. Most convulsion onsets occurred between 25-70 days of age. Mating experiments revealed that 0%(0/18) of the animals in F1, 10%(3/26) in F2, 17%(1/6) in backcross progeny and 86% (100/116) in progeny of crosses between epileptic rats showed tonic-clonic convulsions. Ictal cortical EEGs were characterized by 4-6 (5.1 +/- 0.4, mean +/- SD) Hz spike-and-wave complexes in the absence-like seizures and by low-voltage fast waves in the tonic-clonic convulsions. This new mutant rat spontaneously exhibited both absence-like and tonic-clonic seizures. The tonic-clonic seizure was inherited as an autosomal recessive trait with 86% incidence. Thus, the new mutant rat may become a useful model for studying human inherited epilepsies.

Diphenylarsinic acid (DPAA) was a major compound found in the arsenic poisoning incident that occurred in Kamisu, Ibaraki, Japan in 2003. People exposed to DPAA via contaminated well water suffered from several neurological disorders, including cerebellar symptoms. We previously reported that DPAA induces cellular activation in cultured rat cerebellar astrocytes, dose-dependent promotion of cell growth (low DPAA), cell death (high DPAA), and increased phosphorylation of mitogen-activated protein (MAP) kinases (p38MAPK, SAPK/JNK, and ERK1/2). Moreover, DPAA induces up-regulation of oxidative stress-counteracting proteins, activation of CREB phosphorylation, increased protein expression of c-Jun and c-Fos, and aberrant secretion of brain-active cytokines (MCP-1, adrenomedullin, FGF2, CXCL1, and IL-6). Here, we explored the role of MAP kinases in DPAA-induced activation of astrocytes using specific MAP kinase signaling inhibitors [SB203580 (p38MAPK), SP600125 (SAPK/JNK), SCH772984 (ERK1/2), and U0126 (MEK1/2, a kinase for ERK1/2)]. DPAA-induced activation of MAP kinases had little contribution to DPAA-induced cell growth and death. On the other hand, a power relationship among MAP kinases was also observed, in which p38MAPK suppressed DPAA-induced SAPK/JNK and ERK1/2 activation, whereas ERK1/2 and MEK1/2 facilitated p38MAPK and SAPK/JNK activation. In addition, SAPK/JNK had minimal effects on the activation of other MAP kinases. DPAA-induced activation of transcription factors and secretion of brain-active cytokines were submissively but intricately dominated by MAP kinases. Collectively, our results indicate that DPAA-induced activation of MAP kinases is neither a cell growth-promoting response nor a cytoprotective one but leads to transcriptional disruption and aberrant secretion of brain-active cytokines in cerebellar astrocytes.

We attempted to investigate whether dehydroepiandrosterone sulfate (DHEA-S) levels are associated with remission of major depressive disorder by assessing scores on the 17-Item Structured Interview Guide for the Hamilton Depression before and after antidepressant treatment.Plasma DHEA-S levels in 24 patients diagnosed with major depressive disorder on the basis of Diagnostic and Statistical Manual of Mental Disorders, fourth edition (text revision) before and after antidepressant treatment, and 24 healthy, gender-matched, and age-matched controls were measured using a radioimmunoassay kit.Plasma DHEA-S levels in patients were significantly higher than those in healthy controls. In patients who achieved remission after antidepressant treatment, plasma DHEA-S levels significantly declined compared with the levels before treatment. A significant correlation was observed between changes in DHEA-S levels and Absence of Depressive and Anxious Mood scores, which are calculated from the 2-Item Structured Interview Guide for the Hamilton Depression rating as follows: severity of depressive mood and anxiety in patients before and after antidepressant treatment.These findings suggest that plasma DHEA-S levels can be used as a putative indicator of the state of remission in patients with major depressive disorder. Copyright © 2014 John WileySons, Ltd.

The class IV semaphorin CD100/Sema4D differentially utilizes two distinct receptors: plexin-B1 in nonlymphoid tissues, such as brain and kidney, and CD72 in lymphoid tissues. We have generated CD100-deficient mice and demonstrated that they have functional defects in their immune system, without apparent abnormalities in other tissues. The number of CD5 + B-1 cells was considerably decreased in the mutant mice, whereas conventional B cells and T cells appeared to develop normally. In vitro proliferative responses and immunoglobulin production were reduced in CD100-deficient B cells. The humoral immune response against a T cell–dependent antigen and in vivo priming of T cells were also defective in the mutant mice. These results demonstrate nonredundant and essential roles of CD100-CD72 interactions in the immune system.

To gain a clue to whether the transcription factor CCAAT/enhancer-binding protein β (C/EBPβ) is implicated in mouse behavior, the water maze performance of C/EBPβ(-/-) mice was compared with the performance of their wild type (WT) controls. The escape latencies of C/EBPβ(-/-) mice increased along with the number of trials within all training sessions in the hidden-platform tasks. Even in the visible-platform tasks, their escape latencies did not decrease along with the number of trials. The unusual performance in C/EBPβ(-/-) mice during later trials may allow us to presume that they suffer certain emotional vulnerability to stress from the water-maze training, although the involvement of other factors such as motor or immune system should be also considered.

The CCAAT/enhancer binding proteins related activating transcription factor, C/ATF, is a mouse leucine-zipper transcription factor which is structurally homologous to ApCREB2, a suppressor integral to long-term synaptic plasticity in Aplysia. To gain a clue to whether C/ATF is involved in long-term plasticities of brain, we examined if the expression levels of C/ATF are modulated by cAMP, an inducer crucial for memory formation in Aplysia, Drosophila and mice. Our in situ hybridization analysis revealed the expression of C/ATF mRNA in hippocampal neurons. C/ATF protein levels increased after the cAMP signal stimulation in hippocampal neurons, while C/ATF mRNA levels remained constant. The human activating transcription factor 4 (hATF4), another homolog of ApCREB2, interacts with multiple domains of the coactivator CREB-binding protein (CBP), resulting in the potentiation of its ability to activate transcription. As expected, C/ATF was found to interact with three domains of CBP including CREB binding domain or kinase-inducible interaction (KIX) domain, the third cysteine-histidine-rich region (CH3 domain) and the nuclear receptor coactivator p160/SRC-1-interacting domain. Interestingly, C/ATF was further found to interact strongly with CREB binding protein/p300 (CBP/p300) CH1 domain. Mammalian two hybrid assays indicated that the interaction between C/ATF and CBP/p300 can occur in mammalian cells, and that the p300 CH1 domain is critical for the interaction. Thus, C/ATF may be implicated in transcription-dependent phase of hippocampal long-term plasticities through the modulation of its protein level under cAMP signal and the interaction with signal integrator, CBP/p300.

A recent study showed that both 5-fluorouracil (5FU)-stimulated apoptosis and Fas-mediated apoptosis in human endometrial adenocarcinoma cells are enhanced by targeted knockdown of endogenous death-associated protein kinase (DAPK) with DAPK small-interfering RNAs. Therefore, we investigated the DAPK survival signals in three 5FU-resistant subclones. DAPK knockdown did not enhance 5FU-stimulated or Fas-mediated apoptosis in any of the three 5FU-resistant subclones, but the subclones acquired resistance to VP16-stimulated cell death that was DAPK-independent. Semi-quantitative flow cytometric analyses showed that there was no differential expression in nine cell surface antigens, including Fas, and six intracellular molecules, including DAPK, that may regulate cell death or survival between the parent cells and 5FU-resistant cells. DAPK mRNA and protein were expressed in the 5FU-resistant subclones at similar levels to the parent cells. These results indicate that acquisition of 5FU-resistance may be accompanied by impairment of common apoptotic signals regulating both DAPK-dependent and DAPK-independent pathways.

Targeted knockdown of the death-associated protein kinase (DAPK) expression in the endometrial adenocarcinoma HHUA cells reportedly induces cell death by enhancing the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis in an autocrine/paracrine manner. This suggests that endogenous DAPK is a potential candidate for a molecularly targeted anticancer therapy for patients with endometrial adenocarcinoma. To investigate the role of endogenous DAPK in anticancer drug sensitivity, we examined effects on cellular anticancer drug sensitivities of transfections with 5 different specific DAPK small-interfering RNAs (siRNAs) into HHUA cells. DAPK siRNA transfections strongly enhanced 5-fluorouracil (5FU)-sensitivity, but not etoposide-sensitivity, of HHUA cells compared with control siRNA-transfected cells. These results indicate that etoposide-stimulated cell death signals may share or include TRAIL-mediated apoptotic signals, and that 5FU-stimulated cell death signals may be independent from TRAIL-mediated apoptotic signals induced by DAPK siRNA transfections. Moreover, 5FU-combined chemotherapy with DAPK siRNA transfection may show stronger anticancer effects on patients with endometrial adenocarcinoma than does chemotherapy alone.

Several endometrial signal transducer and activator of transcription 3 (STAT3)-activating cytokines are reported to be essential for blastocyst implantation, with inhibition of STAT3 activation in the endometrium also reported to prevent implantation. To investigate STAT3 signals in endometrial epithelial cells, the activation and inactivation effects of STAT3 signals were examined in the human endometrial epithelial cell line HHUA, which is thought to retain many of the intracellular signaling pathways found in normal human endometrial epithelial cells. Five STAT3-activating cytokines, IL-11, IL-10, LIF, oncostatin M and leptin, enhanced the Fas-mediated apoptosis of the HHUA cells without any increase in cell surface Fas antigen expression. STAT3 siRNA transfection suppressed STAT3 expression in HHUA cells and significantly inhibited Fas-mediated cell death. These results indicate that intracellular apoptotic signals in HHUA cells are constitutively activated and regulated by STAT3-mediated signals. This apoptosis-promoting effect of STAT3 in HHUA cells is completely different from many previous reports demonstrating anti-apoptotic effects by STAT3 activation. The STAT3 signals in HHUA cells may be specific to the human endometrial epithelial cell lineage in the regulation of blastocyst implantation.

We recently showed that targeted knockdown of death-associated protein kinase (DAPK) expression induces apoptosis in the human endometrial adenocarcinoma cell line HHUA. To investigate the possibility that DAPK may represent a molecular target for anticancer therapies for advanced uterine cancers, we examined the effects of DAPK siRNA transfections on the viability of five different human uterine cancer cell lines. The five uterine cell lines comprised three differentiated endometrial adenocarcinomas, one leiomyosarcoma and one carcinosarcoma. Cell death assays showed that the DAPK siRNA transfection significantly increased the cell death in all five uterine cancer cells examined. Ribonuclease protection assays did not show any remarkable changes in the bcl-2 family gene expressions after the DAPK siRNA transfection in HHUA cells. Since DAPK-mutant mice were reported to be fertile and do not show lethality, DAPK may play a central role in the immortalization and carcinogenesis of uterine cancer cells, possibly without bcl-2 family-related apoptotic regulation. These results indicate that DAPK can be a convincing candidate for molecularly targeted anticancer therapies for patients with various types of advanced uterine cancers, including carcinosarcoma and leiomyosarcoma.

Neovascularization occurring in atherosclerotic plaque leads to acceleration of plaque growth through increased leukocyte infiltration and reactive oxygen species (ROS) production. Sema4D (CD100), a class IV semaphorin, not only plays a crucial role in axon guidance but also functions in the neovascularization process of tumor growth. To clarify the roles of Sema4D in the progression of atherosclerosis and neovascularization of atherosclerotic plaque, we analyzed the effect of Sema4D gene deletion from apolipoprotein E (ApoE)-deficient mice in the development of atherosclerosis. Lipid staining demonstrated significant decreases in plaque areas in the aortas of 6-month-old Sema4D-/- ApoE-/- mice compared with 6-month-old ApoE-/- mice. Thus, the Sema4D gene knockout in ApoE-deficient mice was found to slow the progression of atherosclerosis. Immunohistochemical analyses confirmed the expression of Sema4D protein in infiltrating lymphoid cells in atherosclerotic plaque and plexin-B1 receptor in neovascular endothelial cells within the plaque. Furthermore, there were significant decreases in the degree of neovascularization in the plaque areas of Sema4D-/- ApoE-/- mice compared with ApoE-/- mice as revealed by both isolectin B4 and CD31 staining. The number of infiltrating macrophages in Sema4D-/- ApoE-/- mice plaques was also significantly less than those in ApoE-/- mice. These findings suggest that Sema4D is involved in the progression phase of atherosclerosis by accelerating intimal neovascularization, resulting in enhanced macrophage infiltration in atherosclerotic plaques.

Death-associated protein kinase (DAPK) is a serine/threonine kinase that participates in the modulation of apoptosis and tumor suppression. Our previous study revealed high levels of DAPK protein expression in differentiated endometrial adenocarcinoma cells. To clarify the role of DAPK in human endometrial adenocarcinomas, we down-regulated endogenous DAPK expression in HHUA cells, a well-differentiated endometrial adenocarcinoma cell line, using specific small-interfering RNAs (siRNAs). The suppression of endogenous DAPK expression triggered apoptosis in HHUA cells, as evidenced by an increase in the sub-G1 DNA content in flow cytometric analyses. The apoptosis induced by the DAPK siRNA transfections was caspase-dependent, as characterized by the activations of caspase-3, -8 and -9. RNase protection assays detected higher levels of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), DR4 and DR5 transcripts in the DAPK siRNA-transfected HHUA cells than in the control siRNA-transfected cells. Consistent with these findings, enzyme-linked immunosorbent assays revealed that the DAPK siRNA transfections significantly increased the secretion of TRAIL protein from the cells. Treatment with recombinant human TRAIL protein dose-dependently suppressed the cell viability of HHUA cells. The present findings reveal that down-regulation of endogenous DAPK expression in HHUA cells induces caspase-dependent apoptosis, possibly through increased TRAIL, DR4 and DR5 signaling, thereby suggesting that DAPK expression is essential for HHUA cell survival. Consequently, endogenous DAPK mRNA may represent a potential candidate for molecularly targeted anticancer therapies.

Semaphorins are a family of secreted and membrane-bound proteins known as axonal pathfinders. Sema4A, a member of class 4 semaphorins, induces growth cone collapse of hippocampal neurons. The binding of Sema4A to growth cones indicates the presence of receptors transmitting signals through the intracellular effectors to induce growth cone collapse in hippocampal neurons. Transfection experiments of the candidate receptor genes into COS-7 cells demonstrated that Sema4A binds to axonal guidance receptors Plexin-B1, -B2 and -B3. To identify the functional Sema4A receptor and the signal transduction machinery, COS-7 cell contraction assay was performed, in which intracellular signal transmission induced by Sema4A triggered cell contraction. Expression vectors encoding plexins and Rnd1, a Rho family GTPase, were transfected into COS-7 cells, and a proportion of contracted cells among the transfectants was determined after incubation with Sema4A. The results demonstrated that the combination of Rnd1 and Plexin-B1, -B2 or -B3 induced significant cell contraction, indicating that B-type plexins transmit an intracellular signal of Sema4A through Rnd1. To further study the mechanism of B-type plexin-mediated signaling in Sema4A-induced growth cone collapse, mouse hippocampal neurons transfected with a control or expression plasmid encoding a constitutively active mutant of R-Ras (R-RasQL) were stimulated with Sema4A, followed by the assessment of growth cone collapse. Expression of R-RasQL significantly blocked Sema4A-induced growth cone collapse in the hippocampal neurons compared with the control plasmid. Sema4A thus induces growth cone collapse through the down-regulation of R-Ras activity in mouse hippocampal neurons.

We have previously identified two species of the low-affinity human Fc receptor for IgE, Fc epsilon RIIa and Fc epsilon RIIb, which differ only in a short stretch of amino acids at the N-terminal cytoplasmic end. Their differential expressions on B cells and monocytes suggest that Fc epsilon RIIa and Fc epsilon RIIb are involved in B-cell function and IgE-mediated immunity, respectively. Here we show that Fc epsilon RII-mediated endocytosis is observed only in Fc epsilon RIIa-expressing cells, whereas IgE-dependent phagocytosis is observed only in Fc epsilon RIIb-expressing cells, demonstrating the functional difference between Fc epsilon RIIa and Fc epsilon RIIb. Furthermore, site-directed mutagenesis revealed that the tyrosine residue in the Fc epsilon RIIa-specific region is important for endocytosis, and the Asn-Pro residues in the Fc epsilon RIIb-specific region are required for phagocytosis. These findings suggest that endocytosis and phagocytosis are functionally separable phenomena involving distinct amino acid residues.

Although death-associated protein kinase (DAPK) is a Ca 2+ /calmodulin-regulated serine/threonine kinase that plays important roles in various types of apoptotic cell death, there have been no reports of its tissue distributions and functions in female reproductive organs. By comparing C57BL/6 wild-type mice with DAPK-mutant mice lacking the 74-amino acid catalytic kinase domain of DAPK, the cellular distributions and biological functions of DAPK in murine ovaries were investigated. In situ hybridization analyses with sense and antisense riboprobes revealed that DAPK mRNA was selectively and highly expressed in granulosa cells in the ovaries of both types of mice. There were no significant differences in the body weights, ovarian weights and unstimulated ovarian follicular numbers between the wild-type and DAPK-mutant mice. Intraperitoneal injection of CPT-11, an anticancer topoisomerase I inhibitor that causes granulosa cell-specific apoptosis partly through Fas-Fas ligand (FasL) interactions in MCH mice, induced follicular apoptosis in both the wild-type and DAPK-mutant mice. However, the numbers of apoptotic follicles were significantly reduced in the DAPK-mutant mice. The Fas and FasL expression levels in the CPT-11-injected mice did not differ significantly between the wild-type and DAPK-mutant mice. These results indicate that DAPK positively regulates intracellular signaling pathways for CPT-11-induced granulosa cell apoptosis.

Minimal optimal surgery without chemotherapy is often performed for patients with ovarian immature teratoma, which frequently occurs in young women who hope for future pregnancies. If tumors recur after the operation, anticancer drug chemotherapy is often administered, although few studies have highlighted differences between the recurrent and the primary tumor cells. Therefore, we have established experimental animal models of recurrent ovarian immature teratoma cells after optimal surgery and characterized the anticancer drug sensitivity and antigenicity of the recurrent tumors. Surgically-excised tumor cells of a grade II ovarian immature teratoma were cultured in vitro and transplanted into nude mice to establish stable cell lines. Differential drug sensitivity and antigenicity of the tumor cells were compared between the primary and the nude mouse tumors. Nude mouse tumor cells showed a normal 46XX karyotype. Cultured primary cells showed a remarkably high sensitivity to paclitaxel, docetaxel, adriamycin and pirarubicin, compared to peritoneal cancer cells obtained from a patient with ovarian adenocarcinomatous peritonitis. The drug sensitivity of teratoma cells to 5-fluorouracil, bleomycin or peplomycin was also significantly higher. However, there was no significant difference in sensitivity to platinum drugs between the primary teratoma and the peritoneal adenocarcinoma cells. As for nude mouse tumor cells, sensitivity to 12 anticancer drugs was significantly lower than that of the primary tumor cells, while there was little difference in sensitivity to carboplatin or peplomycin between the primary and nude mouse tumor cells. Flow cytometry showed that the expression of smooth muscle actin (SMA) significantly decreased in nude mouse tumor cells when compared to cultured primary cells. In conclusion, ovarian immature teratomas with normal karyotypes have a malignant potential to recur after minimal surgery. During nude mouse transplantation, SMA-overexpressing cells appeared to be selectively excluded and nude mouse tumor cells were less sensitive to the majority of anticancer drugs than the primary tumor cells. These results indicate that after optimal surgery for ovarian immature teratoma, recurrent cells can be more resistant to anticancer drugs than the primary tumors. Therefore, it is likely that adjuvant chemotherapy lowers the risk of ovarian immature teratomas recurring after optimal surgery. BEP and PBV regimens are frequently given to teratoma patients. However, paclitaxel/carboplatin or docetaxel/carboplatin, which are the most effective chemotherapy treatments for epithelial ovarian cancer patients, are considered to be an alternative regimen, especially in the prevention of reproductive toxicity.

Adrenomedullin 2 (AM2), a novel member of the calcitonin gene-related peptide family, has emerged as a multifunctional peptide controlling endocrine and cardiovascular functions and physiological behaviors. Both central and peripheral administration of AM2 can have profound effects on systemic and/or pulmonary circulation in mammals. However, the target nuclei of AM2 and the role of central AM2 in cardiovascular regulation remain unknown. In the present study, we microinjected AM2 into the rat nucleus tractus solitarius (NTS), the central termination site of baroreceptor afferents. Consistent with previous reports showing the hypertensive effect of intracerebroventricular administration of AM2, the direct microinjection of the peptide into the NTS increased arterial pressure as well as heart rate in rats. Importantly, this effect of AM2 on cardiovascular regulation was significantly attenuated by an antagonist of receptor components for AM2 that were abundant in the rat NTS. Our results indicate that AM2 may play an important role in the regulation of the cardiovascular system at the NTS level.

Systemic administration of urocortin I (Ucn I), a member of the corticotrophin-releasing factor (CRF) peptide family, modulates cardiovascular system. In the central nervous system, Ucn I is found in the nucleus tractus solitarii (NTS), which plays an important role in regulating arterial blood pressure (ABP) and heart rate (HR) in response to activation of the baroreceptor afferents. In this study, we examined the effects of Ucn I, which has a high affinity for both type 1 and type 2 CRF receptors (i.e. CRF-R1 and -R2), on cardiovascular functions at the level of the NTS. A specific agonist of CRF-R1 (i.e. CRF) and a specific agonist of CRF-R2 (i.e. Urocortin II) were also tested to identify the specific cardiovascular effects induced by individual activation of either CRF-R1 or -R2. We found that Ucn I microinjected into the rat NTS produced a significant reduction in both ABP and HR. Both agonists for CRF-R1 and -R2 microinjected into the NTS also reduced ABP and HR. Our results suggest that Ucn I in the NTS may play an important role in cardiovascular regulation and the cardiovascular effects of Ucn I may be mediated by activation of both CRF-R1 and -R2, which are known to be present in the NTS.

The Fc epsilon receptor II (Fc epsilon RII/CD23) has been proposed to have multiple functions as a membrane-bound or soluble molecule: a function in B cell growth and differentiation and a role in the effector phase of IgE-mediated immunity. We recently demonstrated the presence of two forms of Fc epsilon RII (Fc epsilon RIIa and Fc epsilon RIIb) whose structures differ only at their N-terminal cytoplasmic regions. The regulatory mechanisms of their expression strongly suggest that Fc epsilon RIIa and Fc epsilon RIIb function in B cells and in the effector cells of IgE-mediated immunity, respectively. To elucidate the function of soluble Fc epsilon RII/CD23 (sFc epsilon RII) the recombinant soluble molecule was produced. This recombinant receptor could competitively block the IgE binding of eosinophils, monocytes and even basophils and could inhibit the IgE-mediated function of effector cells such as monocytes. These findings suggested that sFc epsilon RII could competitively regulate the function of effector cells in IgE-mediated immunity and that the recombinant sFc epsilon RII could be applied clinically for the control of allergic reactions. The expression of Fc epsilon RII on Fc epsilon RII-negative B and T cell lines by cDNA transfection resulted in homocytic aggregation. The function of Fc epsilon RII on B cells as an adhesion molecule was also demonstrated.

Patients with unresectable advanced carcinoma of the uterine cervix are usually treated with chemotherapy or chemoradiotherapy. In the present study, the optimal administration protocol for etoposide in chemotherapy and chemoradiotherapy for advanced cervical cancer patients was investigated in vitro using the radio-sensitive and anticancer drug-sensitive human cervical squamous cell carcinoma cell line ME180. Therapeutic doses of concurrent irradiation reduced the cellular etoposide sensitivity in a dose-dependent manner, while postirradiation-surviving subclones established from repeatedly irradiated ME180 cells showed significantly higher etoposide sensitivities than the non-irradiated parent cells. Of the 6 monoclonal etoposide-resistant subclones established from ME180 cells, 5 were significantly radio-resistant. Although the etoposide-resistant subclones were also significantly resistant to other anticancer drugs, such as cisplatin, carboplatin, nedaplatin, pirarubicin, paclitaxel and docetaxel, they were more sensitive to 5-fluorouracil, mitomycin C and SN38 than the parent cells. Flow cytometric analyses revealed that the etoposide-resistant subclones showed significantly increased cell surface expression of CD40 compared to the parent cells, which expressed undetectable levels of CD40. However, the expression of some integrin receptor subunits, such as CD29, CD49a and CD49f, was apparently reduced in the etoposide-resistant subclones. These results indicate that etoposide should be administered to advanced cervical squamous cancer patients after the completion of radiotherapy, rather than as a concurrent chemoradiotherapy. In order to kill surviving etoposide-resistant cancer cells more effectively, 5-fluorouracil, mitomycin C and irinotecan may be candidate combination drugs for use with etoposide. Differential expression of integrin receptors and CD40 may be involved in the acquisition of etoposide resistance by cervical squamous cancer cells.

The molecular mechanism for cisplatin (CDDP)-resistance of cancer cells has not yet been clarified, despite extensive studies. Here, we investigated whether death-associated protein (DAP) kinase, an apoptosis modulator, was involved in CDDP-resistance by examining the ME180 human cervical squamous cancer cell line and 6 monoclonal ME180-derived CDDP-resistant subclones. Co-treatment with CDDP and 5-aza-2'-deoxycytidine (5-aza-CdR), a demethylating agent, significantly enhanced the CDDP-sensitivities of the parent cells and CDDP-resistant subclones. Subsequent removal of 5-aza-CdR rapidly reversed the CDDP-sensitivity of the CDDP-resistant subclones to their original levels, whereas the parent cells retained the enhanced CDDP-sensitivity for at least 24 h. Quantitative RT-PCR revealed that the CDDP-resistant subclones expressed higher DNA methyltransferase (DNMT) mRNA levels than the parent cells, suggesting that increased DNMT expressions easily restored the CDDP-resistance of the CDDP-resistant subclones following 5-aza-CdR removal. Although the parent cells showed hypermethylation in the DAP kinase promoter region, corresponding methylated bands were not detected in 2 of the 6 CDDP-resistant subclones by methylation-specific PCR. All 6 CDDP-resistant subclones expressed higher DAP kinase mRNA levels than the parent cells, as evaluated by quantitative RT-PCR. Although DAP kinase protein expression was strongly suppressed in the parent cells and CDDP-resistant subclones, 5-aza-CdR treatment of the parent cells dose-dependently stimulated the DAP kinase protein expression, and this was synergistically enhanced by inhibiting histone deacetylation via trichostatin treatment in addition to 5-aza-CdR. However, DAP kinase protein expression in the CDDP-resistant subclones was not stimulated by treatment with 5-aza-CdR and/or trichostatin. These results indicate that post-transcriptional translation of DAP kinase mRNA is strongly suppressed and insensitive to treatment with 5-aza-CdR and trichostatin in the CDDP-resistant subclones established from ME180 human cervical squamous cancer cells. This CDDP-resistance is accompanied by molecular changes that disturb the post-transcriptional translation of the DAP kinase mRNA, and these molecular changes are transiently restored by demethylation.

To examine the possibility of a cervical squamous cell carcinoma-specific growth factor(s), previously suggested by clinical findings and in vitro culture experiments, we examined in vitro cultures and nude mouse transplantations of cervical squamous cell carcinoma cells obtained from a patient with a bulky cervical tumor without detectable distant metastases. The cancer cells did not proliferate without additional growth factors but remained viable in vitro. Fourteen weeks after transplantation of the tumor cells on their backs, 1 of the 3 nude mice developed large metastatic pelvic tumors without macroscopic metastatic lesions in their lungs or liver. When these pelvic tumor fragments were trans-planted onto the backs of other nude mice, ulcerated back tumors and larger metastatic pelvic tumors, but no macroscopic metastatic lesions in the lungs or liver, were observed. Histopathological examination of these pelvic tumors showed that all were the same squamous cell carcinoma as the primary tumor. These results indicate that cell proliferation of bulky cervical squamous cell carcinoma is strongly associated with a squamous cell carcinoma-specific growth factor(s) in a paracrine manner.

Irinotecan HCl (CPT-11) has frequently been used in chemotherapy or concurrent chemoradiotherapy for patients with advanced cervical cancer, although an effective protocol for chemoradiotherapy with CPT-11 has not yet been established. Using the radiosensitive human cervical squamous cell carcinoma cell line ME180 and SN38, a major active metabolite of CPT-11, both the SN38 effects on radiosensitivity and irradiation effects on SN38 sensitivity were investigated to optimize the chemoradiotherapy protocol for CPT-11. SN38 had no effect on radiosensitivity, and irradiation did not affect SN38 sensitivity. Moreover, 3 of 4 post-irradiation surviving subclones obtained from repeatedly irradiated ME180 cells showed no significant changes in their SN38 sensitivities compared with the non-irradiated parent cells. On the other hand, all 7 SN38-resistant subclones established from ME180 cells showed strong reduction in their radiosensitivities. These results suggest that CPT-11 should be administered to advanced cervical cancer patients after, but not before, standard radiotherapy, and concurrent administration of SN38 with radiotherapy should be avoided in order to prevent severe adverse effects, such as watery diarrhea, which is the main adverse effect of pelvic radiotherapy or CPT-11.

To investigate the interaction between anticancer drug resistance and radioresistance in cervical cancer cells, 3 single cell-derived cyclophosphamide-resistant subclones were established from the drug- and radiosensitive human cervical squamous cell carcinoma cell line ME180 by chronic exposure cultures with 4-hydroxy-cyclophosphamide followed by limiting dilution. The established cyclophosphamide-resistant subclones were also radio- and multidrug-resistant to 7 other anticancer drugs. Flow cytometric analysis revealed significantly increased levels of CD40 expression on the 3 resistant subclones, whereas no CD40 expression was found on the parent ME180 cells. However, there were no changes in the expression levels of CD29, CD49a-CD49f or CD59 between the parent cells and resistant subclones. A recombinant human soluble CD40 ligand had no effect on the proliferation of the resistant subclones. Irradiation had no effect on the 4-hydroxy-cyclophosphamide sensitivity of the parent cells. These results indicate that the established cyclophosphamide-resistant subclones have impaired cell death signals, which are common to both drug- and radiation-induced apoptosis, and cyclophosphamide may not be an adequate drug for use in concurrent chemoradiotherapy. Furthermore, CD40 activation signals may be associated with the multidrug- and radioresistance in these cyclophosphamide-resistant subclones.