Influences of Pre-formed Donor-Specific Anti-Human Leukocyte Antigen Antibodies in Living-Donor Renal Transplantation: Results With Graft Immunocomplex Capture Fluorescence Analysis.

BACKGROUND: Advances in immunosuppressants enable organ transplantation for sensitized patients. However, influences of pre-formed donor-specific anti-human leukocyte antigen (HLA) antibodies (DSA) have not been fully understood in renal transplantation (RT). On the other hand, immunocomplex capture fluorescence analysis (ICFA) is a reliable method to detect donor-specific anti-HLA antibodies and HLA antigen complexes. Graft ICFA can detect DSA in an allograft (g-DSA). METHODS: To elucidate the consequences of pre-formed DSA, 198 patients who underwent living-donor RT were enrolled for this study (observation period: 57.8 ± 34.9 months); 187 patients in the DSA- group (excluding ABO-incompatible cases) and 11 patients in the DSA+ group. Before RT, all DSA+ patients had undergone rituximab administration and plasmapheresis. For a graft ICFA, the biopsy specimen (1 × 105 cells) was dissolved, and HLA antigens were captured by anti-HLA beads. Finally, DSA-HLA complexes were detected by means of PE-conjugated anti-human IgG antibodies and analyzed by use of a Luminex system. A ratio (sample/blank beads, mean of fluorescence intensity) was calculated: ≥1.0 was determined as positive g-DSA. RESULTS: There were no significant differences in 5-year graft survival (87.9%/100% in the DSA-/DSA+ groups, respectively). In terms of antibody-mediated rejection (AMR), within 1 month after RT, pathologically determined AMR occurred 3.2% and 63.4% in the DSA- and DSA+ groups, respectively (P < .0001). However, interestingly, more than half of them (57.1%) indicated only subclinical AMR, that is, no fluctuation of S-Cr. As representative of 2 cases of subclinical AMR, g-DSA deposition could be confirmed (1.15 ± 0.04) at 1 hour after reperfusion by graft ICFA. Furthermore, g-DSA shifted to 2.20 ± 0.98 at 3 weeks after transplantation, along with a decline in s-DSA mean of fluorescence intensity (1718-506.5). CONCLUSIONS: Although pathologically determined AMR occurred more frequently in pre-formed DSA+ recipients, it can be argued that a successful de-sensitization protocol inhibits further production of DSA and graft destruction.

Regulation of alternative splicing of Bcl-x by BC200 contributes to breast cancer pathogenesis.

BC200 is a long non-coding RNA (lncRNA) that has been implicated in the regulation of protein synthesis, yet whether dysregulation of BC200 contributes to the pathogenesis of human diseases remains elusive. In this study, we show that BC200 is upregulated in breast cancer; among breast tumor specimens there is a higher level of BC200 in estrogen receptor (ER) positive than in ER-negative tumors. Further experiments show that activation of estrogen signaling induces expression of BC200. To determine the significance of ER-regulated BC200 expression, we knockout (KO) BC200 by CRISPR/Cas9. BC200 KO suppresses tumor cell growth in vitro and in vivo by expression of the pro-apoptotic Bcl-xS isoform. Mechanistically, BC200 contains a 17-nucleotide sequence complementary to Bcl-x pre-mRNA, which may facilitate its binding to Bcl-x pre-mRNA and recruitment of heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1, a known splicing factor. Consequently, hnRNP A2/B1 interferes with association of Bcl-x pre-mRNA with the Bcl-xS-promoting factor Sam68, leading to a blockade of Bcl-xS expression. Together, these results suggest that BC200 plays an oncogenic role in breast cancer. Thus, BC200 may serve as a prognostic marker and possible target for attenuating deregulated cell proliferation in estrogen-dependent breast cancer.

Regulation of breast tumorigenesis through acid sensors.

The low extracellular pH in the microenvironment has been shown to promote tumor growth and metastasis; however, the underlying mechanism is poorly understood. Particularly, little is known how the tumor cell senses the acidic signal to activate the acidosis-mediated signaling. In this study, we show that breast cancer cells express acid-sensing ion channel 1 (ASIC1), a proton-gated cation channel primarily expressed in the nervous system. RNA interference, knockout and rescue experiments demonstrate a critical role for ASIC1 in acidosis-induced reactive oxidative species and NF-κB activation, two key events for tumorigenesis. Mechanistically, ASIC1 is required for acidosis-mediated signaling through calcium influx. We show that as a cytoplasmic membrane protein, ASIC1 is also associated with mitochondria, suggesting that ASIC1 may regulate mitochondrial calcium influx. Importantly, interrogation of the Cancer Genome Atlas breast invasive carcinoma data set indicates that alterations of ASIC1 alone or combined with other 4 ASIC genes are significantly correlated with poor patient survival. Furthermore, ASIC1 inhibitors cause a significant reduction of tumor growth and tumor load. Together, these results suggest that ASIC1 contributes to breast cancer pathogenesis in response to acidic tumor microenvironments, and ASIC1 may serve as a prognostic marker and a therapeutic target for breast cancer.

miR-509 suppresses brain metastasis of breast cancer cells by modulating RhoC and TNF-α.

The median survival time of breast cancer patients with brain metastasis is less than 6 months, and even a small metastatic lesion often causes severe neurological disabilities. Because of the location of metastatic lesions, a surgical approach is limited and most chemotherapeutic drugs are ineffective owing to the blood brain barrier (BBB). Despite this clinical importance, the molecular basis of the brain metastasis is poorly understood. In this study, we have isolated RNA from samples obtained from primary breast tumors and also from brain metastatic lesions followed by microRNA profiling analysis. Our results revealed that the miR-509 is highly expressed in the primary tumors, whereas the expression of this microRNA is significantly decreased in the brain metastatic lesions. MicroRNA target prediction and the analysis of cytokine array for the cells ectopically expressed with miR-509 demonstrated that this microRNA was capable of modulating the two genes essential for brain invasion, RhoC and TNF-α that affect the invasion of cancer cells and permeability of BBB, respectively. Importantly, high levels of TNF-α and RhoC-induced MMP9 were significantly correlated with brain metastasis-free survival of breast cancer patients. Furthermore, the results of our in vivo experiments indicate that miR-509 significantly suppressed the ability of cancer cells to metastasize to the brain. These findings suggest that miR-509 has a critical role in brain metastasis of breast cancer by modulating the RhoC-TNF-α network and that this miR-509 axis may represent a potential therapeutic target or serve as a prognostic tool for brain metastasis.

Long non-coding RNA UCA1 promotes breast tumor growth by suppression of p27 (Kip1).

Functional genomics studies have led to the discovery of a large amount of non-coding RNAs from the human genome; among them are long non-coding RNAs (lncRNAs). Emerging evidence indicates that lncRNAs could have a critical role in the regulation of cellular processes such as cell growth and apoptosis as well as cancer progression and metastasis. As master gene regulators, lncRNAs are capable of forming lncRNA-protein (ribonucleoprotein) complexes to regulate a large number of genes. For example, lincRNA-RoR suppresses p53 in response to DNA damage through interaction with heterogeneous nuclear ribonucleoprotein I (hnRNP I). The present study demonstrates that hnRNP I can also form a functional ribonucleoprotein complex with lncRNA urothelial carcinoma-associated 1 (UCA1) and increase the UCA1 stability. Of interest, the phosphorylated form of hnRNP I, predominantly in the cytoplasm, is responsible for the interaction with UCA1. Moreover, although hnRNP I enhances the translation of p27 (Kip1) through interaction with the 5'-untranslated region (5'-UTR) of p27 mRNAs, the interaction of UCA1 with hnRNP I suppresses the p27 protein level by competitive inhibition. In support of this finding, UCA1 has an oncogenic role in breast cancer both in vitro and in vivo. Finally, we show a negative correlation between p27 and UCA in the breast tumor cancer tissue microarray. Together, our results suggest an important role of UCA1 in breast cancer.

Negative regulation of lncRNA GAS5 by miR-21.

In addition to protein-coding genes, the human genome makes a large amount of noncoding RNAs, including microRNAs and long noncoding RNAs (lncRNAs). Both microRNAs and lncRNAs have been shown to have a critical role in the regulation of cellular processes such as cell growth and apoptosis, as well as cancer progression and metastasis. Although it is well known that microRNAs can target a large number of protein-coding genes, little is known whether microRNAs can also target lncRNAs. In the present study, we determine whether miR-21 can regulate lncRNA expression. Using the lncRNA RT-PCR (reverse transcription-polymerase chain reaction) array carrying 83 human disease-related lncRNAs, we show that miR-21 is capable of suppressing the lncRNA growth arrest-specific 5 (GAS5). This negative correlation between miR-21 and GAS5 is also seen in breast tumor specimens. Of interest, GAS5 can also repress miR-21 expression. Whereas ectopic expression of GAS5 suppresses, GAS5-siRNA increases miR-21 expression. Importantly, there is a putative miR-21-binding site in exon 4 of GAS5; deletion of the miR-21-binding site abolishes this activity. Experiments with in vitro cell culture and xenograft mouse model suggest that GAS5 functions as a tumor suppressor. We further show that the biotin-labeled GAS5-RNA probe is able to pull down the key component (AGO2) of the RNA-induced silencing complex (RISC) and we subsequently identify miR-21 in this GAS5-RISC complex, implying that miR-21 and GAS5 may regulate each other in a way similar to the microRNA-mediated silencing of target mRNAs. Together, these results suggest that miR-21 targets not only tumor-suppressive protein-coding genes but also lncRNA GAS5.

Elevated lipogenesis in epithelial stem-like cell confers survival advantage in ductal carcinoma in situ of breast cancer.

Upregulation of lipogenesis is a hallmark of cancer and blocking the lipogenic pathway is known to cause tumor cell death by apoptosis. However, the exact role of lipogenesis in tumor initiation is as yet poorly understood. We examined the expression profile of key lipogenic genes in clinical samples of ductal carcinoma in situ (DCIS) of breast cancer and found that these genes were significantly upregulated in DCIS. We also isolated cancer stem-like cells (CSCs) from DCIS.com cell line using cell surface markers (CS24(-)CD44(+)ESA(+)) and found that this cell population has significantly higher tumor-initiating ability to generate DCIS compared with the non-stem-like population. Furthermore, the CSCs showed significantly higher level of expression of all lipogenic genes than the counterpart population from non-tumorigenic breast cancer cell line, MCF10A. Importantly, ectopic expression of SREBP1, the master regulator of lipogenic genes, in MCF10A significantly enhanced lipogenesis in stem-like cells and promoted cell growth as well as mammosphere formation. Moreover, SREBP1 expression significantly increased the ability of cell survival of CSCs from MCF10AT, another cell line that is capable of generating DCIS, in mouse and in cell culture. These results indicate that upregulation of lipogenesis is a pre-requisite for DCIS formation by endowing the ability of cell survival. We have also shown that resveratrol was capable of blocking the lipogenic gene expression in CSCs and significantly suppressed their ability to generate DCIS in animals, which provides us with a strong rationale to use this agent for chemoprevention against DCIS.

Metallothionein-III prevents neuronal death and prolongs life span in amyotrophic lateral sclerosis model mice.

Defect of metallothionein-III (MT-III) has been reported to be a contributor to the progression of amyotrophic lateral sclerosis (ALS). We explored the expression and effects of MT-III on the motor neurons of spinal cords of ALS model mice (G93A Cu/Zn superoxide dismutase (SOD-1) mutant-transgenic (Tg) mice) using a retrograde viral delivery system. Once-weekly injection of the adenovirus encoding LacZ or MT-III gene was started at the age of 20 weeks, which was the mean age of ALS onset. Gene expression was detected in the motor neurons of the lumbar spinal cord. At 160 days of age (14 days after injection), the mean numbers of Nissl-stained α neurons were 15.42±5.32, 16.50±1.35, and 24.75±4.01 in 5-µm sections of the lumbar hemispinal cord from the untreated group, LacZ group, and MT-III group, respectively. The mean durations of illness were 15.20±5.30 days, 10.33±4.27 days, and 25.71±7.67 days in the untreated group, LacZ group, and MT-III group, respectively. The mean life spans were 163.20±7.72 days, 159.50±3.27 days, and 178.14±12.97 days in the untreated group, LacZ group, and MT-III group, respectively. We demonstrated that MT-III prevents the loss of motor neurons of ALS model mice and prolongs the life span, even when the administration is started at the time of onset.

Hypoxia-induced Jagged2 promotes breast cancer metastasis and self-renewal of cancer stem-like cells.

Notch signaling is often and aberrantly activated by hypoxia during tumor progression; however, the exact pathological role of hypoxia-induced Notch signaling in tumor metastasis is as yet poorly understood. In this study, we aimed to define the mechanism of Notch-ligand activation by hypoxia in both primary tumor and bone stromal cells in the metastatic niche and to clarify their roles in tumor progression. We have analyzed the expression profiles of various Notch ligands in 779 breast cancer patients in GEO database and found that the expression of Jagged2 among all five ligands is most significantly correlated with the overall- and metastasis-free survival of breast cancer patients. The results of our immunohistochemical (IHC) analysis for Jagged2 in 61 clinical samples also revealed that both Jagged2 and Notch signaling were strongly upregulated at the hypoxic invasive front. Activation of Jagged2 by hypoxia in tumor cells induced EMT and also promoted cell survival in vitro. Notably, a γ-secretase inhibitor significantly blocked Notch-mediated invasion and survival under hypoxia by promoting expression of E-cadherin and inhibiting Akt phosphorylation. Importantly, Jagged2 was also found to be upregulated in bone marrow stroma under hypoxia and promoted the growth of cancer stem-like cells by activating their Notch signaling. Therefore, hypoxia-induced Jagged2 activation in both tumor invasive front and normal bone stroma has a critical role in tumor progression and metastasis, and Jagged2 is considered to be a valuable prognostic marker and may serve as a novel therapeutic target for metastatic breast cancer.

Low-dose pretreatment with clorgyline decreases the levels of 3-methoxy-4-hydroxyphenylglycol in the striatum and nucleus accumbens and attenuates methamphetamine-induced conditioned place preference in rats.

The effect of treating rats with clorgyline, an irreversible monoamine oxidase-A (MAO-A) inhibitor, on methamphetamine (METH)-induced conditioned place preference (CPP) was investigated. Administering rats with METH (1.0 mg/kg i.p.) every other day during two conditioning sessions (i.e., saline/METH conditioning with no clorgyline pretreatment) induced a significant CPP compared with saline/saline conditioning. Pretreatment of the rats with clorgyline at a dose of 0.1 mg/kg (i.p.), but not 1.0 or 10 mg/kg, attenuated the METH-induced CPP. Neurochemical analysis using high-performance liquid chromatography revealed that the tissue levels of monoamines and their metabolites were not significantly affected by treatment with 0.1 mg/kg clorgyline except for the levels of 3-methoxy4-hydroxyphenylglycol (MHPG) in the striatum and nucleus accumbens (NAc). Clorgyline at doses of 1.0 or 10 mg/kg significantly affected the tissue levels of 3,4-dihydroxyphenylacetic acid, norepinephrine (NE), MHPG, and serotonin in the cerebral cortex and those of all monoamines and metabolites examined in the striatum and NAc. A significant decrease in the MHPG/NE ratio in the striatum and NAc was apparent in the rats pretreated with 0.1 mg/kg clorgyline. Overall, the present study demonstrated that low-dose clorgyline attenuated METH-induced CPP in rats.

Measuring the frequency of a Sr optical lattice clock using a 120 km coherent optical transfer.

We demonstrate a precision frequency measurement using a phase-stabilized 120 km optical fiber link over a physical distance of 50 km. The transition frequency of the (87)Sr optical lattice clock at the University of Tokyo is measured to be 429228004229874.1(2.4) Hz referenced to international atomic time. The results demonstrate the excellent functions of the intercity optical fiber link and the great potential of optical lattice clocks for use in the redefinition of the second.

Spinal anterior horn cells in sporadic amyotrophic lateral sclerosis show ribosomal detachment from, and cisternal distention of the rough endoplasmic reticulum.

AIMS: Sporadic amyotrophic lateral sclerosis (ALS) is a progressive and invariably fatal disease involving the upper and lower motor neurones of adult humans. Among the neuropathological features of the disease, abnormalities in the protein-synthesizing system in motor neurones of the brainstem and spinal cord, such as a decrease of cytoplasmic RNA and rough endoplasmic reticulum (rER) (chromatolysis), defective editing of the Q/R site of the glutamate receptor subunit GluR2 mRNA, fragmentation of the Golgi apparatus and accumulation of ubiquitinated inclusions and abnormal TdP-43 protein have been reported to be essential for the degeneration. In relation to these features, although the possibility of ER stress has been reported in motor neurones of the brainstem and spinal cord of ALS patients, the rER itself has not been a main target of ultrastructural investigation. METHODS: The present study examined the rER, ultrastructurally and quantitatively in the spinal anterior horn cells (AHCs) of 21 Japanese patients with sporadic ALS and eight Japanese control subjects. RESULTS AND CONCLUSIONS: It was found that: (i) the rER cisternae in AHCs showing central chromatolysis were fragmented, but retained their width and had normally attached ribosomes, and (ii) the rER cisternae in shrunken AHCs were irregularly distended with detachment of the ribosomes, thus suggesting that (iii) ribosomal detachment was related to rER distention.

Adenoviral GDNF gene transfer enhances neurofunctional recovery after recurrent laryngeal nerve injury.

To assess the possibility of gene therapy for recurrent laryngeal nerve (RLN) injury, we examined functional and histological recovery after glial cell line-derived neurotrophic factor (GDNF) gene transfer in a rat RLN crush model. Adenoviral vector encoding beta-galactosidase gene (AxCALacZ) or human GDNF gene (AxCAhGDNF) was injected into the crush site of the RLN. Neurons in the nucleus ambiguus on the crushed side were labeled with X-gal or GDNF immnohistochemistry after AxCALacZ or AxCAhGDNF injection. Reverse transcription-polymerase chain reaction analysis revealed expression of human GDNF mRNA transcripts in brainstem tissue containing the nucleus ambiguus on the crushed side after AxCAhGDNF injection. Animals injected with AxCAhGDNF displayed significantly improved motor nerve conduction velocity of the RLN and recovery rate of vocal fold movement at 2 and 4 weeks after treatment as compared to controls. AxCAhGDNF-injected animals showed a significantly larger axonal diameter and improved remyelination in crushed RLN as compared to controls. Adenoviral GDNF gene transfer may thus promote laryngeal function recovery after RLN injury. Inoculation of adenoviral vector containing the GDNF gene at the site of damage soon after nerve injury may assist patients with laryngeal paralysis caused by nerve injury during head and neck surgery.

A truncated isoform of the PP2A B56gamma regulatory subunit reduces irradiation-induced Mdm2 phosphorylation and could contribute to metastatic melanoma cell radioresistance.

F10, a subline of the B16 mouse melanoma cell line, is itself the parent of the more metastatic BL6 line. BL6 cells differ from F10 cells by an alteration of the gene encoding the B56gamma regulatory subunit of protein phosphatase 2A (PP2A), which results in mRNA encoding a truncated variant of the subunit (deltagamma1). Expression of deltagamma 1 protein is detectable only when BL6 cells are transplanted into mice and then gamma-irradiated. Recently, B56gamma subunit-containing PP2A holoenzymes have shown to dephosphorylate Mdm2, a negative regulator of p53. Thus, we assessed whether the expression of deltagamma1 affects irradiation-induced phosphorylation of Mdm2 and radioresistance of melanoma cells by perturbing the regulation of p53. Western blot analyses revealed that irradiated COS-7 and NIH3T3 cells stably expressing deltagamma1 showed significantly less irradiation-induced Mdm2 phosphorylation. Mdm2 phosphorylation reduces the ability of Mdm2 to target p53 for degradation, which probably explained why p53 protein levels in NIH3T3 cells expressing deltagamma1 were not significantly elevated by irradiation, unlike in wild-type cells. This was also true for F10 cells transfected with deltagamma1 (F10deltagamma1) when the cells expressed deltagamma1 after being irradiated in vivo. p53 mRNA levels in irradiated wild-type and deltagamma 1-expressing cells were both only slightly elevated, suggesting that Mdm2 regulates p53 levels by a post-transcriptional mechanism. p53-mediated induction of the pro-apoptotic gene encoding Bax was also significantly lower in F10deltagamma1 cells irradiated in vivo. Moreover, F10deltagamma1 and BL6 cells were less apoptotic than F10 cells when the cells were irradiated in vivo. The p53 in F10 cells appears to be as functional as that in NIH3T3 cells because irradiation-induced expression of p53-target genes was comparable in both cells. Collectively, deltagamma1 appears to reduce irradiation-induced Mdm2 phosphorylation, which then blocks irradiation-stimulated p53 accumulation. Defects, such as deltagamma1, in PP2A may thus contribute to melanoma cell radioresistance.

Postischemic administration of Sendai virus vector carrying neurotrophic factor genes prevents delayed neuronal death in gerbils.

Sendai virus (SeV) vector-mediated gene delivery of glial cell line-derived neurotrophic factor (GDNF) and nerve growth factor (NGF) prevented the delayed neuronal death induced by transient global ischemia in gerbils, even when the vector was administered several hours after ischemia. Intraventricular administration of SeV vector directed high-level expression of the vector-encoded neurotrophic factor genes, which are potent candidates for the treatment of neurodegenerative diseases. After occlusion of the bilateral carotid arteries of gerbils, SeV vector carrying GDNF (SeV/GDNF), NGF (SeV/NGF), brain-derived neurotrophic factor (SeV/BDNF), insulin-like growth factor-1 (SeV/IGF-1) or vascular endothelial growth factor (SeV/VEGF) was injected into the lateral ventricle. Administration of SeV/GDNF, SeV/NGF or SeV/BDNF 30 min after the ischemic insult effectively prevented the delayed neuronal death of the hippocampal CA1 pyramidal neurons. Furthermore, the administration of SeV/GDNF or SeV/NGF as late as 4 or 6 h after the ischemic insult also prevented the death of these neurons. These results indicate that SeV vector-mediated gene transfer of neurotrophic factors has high therapeutic potency for preventing the delayed neuronal death induced by transient global ischemia, and provides an approach for gene therapy of stroke.

Regionally specific modulation of brain apolipoprotein E in the mouse during the estrous cycle and by exogenous 17beta estradiol.

Studies have suggested that 17beta estradiol (E2) can modify apolipoprotein E (apoE) expression. The current study determined if apoE protein varied in different regions of the mouse brain as a function of the estrous cycle and if E2 could increase apoE protein expression. In this study apoE concentration was lowest on estrus in the hippocampus, cingulate cortex and frontal cortex. In contrast, apoE concentration was highest on estrus in the olfactory bulb and cerebellum. There were no differences in the striatal apoE expression throughout the estrous cycle. Exogenous E2 significantly raised tissue levels of apoE in the olfactory bulb and cerebellum at 5 days after treatment. There was a slight, but nonsignificant increase in cortical expression of apoE and no change in striatum. Immunocytochemical localization studies found estrogen receptor alpha (ERalpha) and estrogen receptor beta (ERbeta) in cortical neurons and glia. In the cerebellum and olfactory bulb, ERbeta was seen primarily in glia. ERalpha was not observed in the cerebellum and was rare in the olfactory bulb. Neither ERalpha nor ERbeta was seen in the striatum. Our data show regional differences in the production of apoE throughout the estrous cycle. In addition, exogenous E2 has regionally specific effects on apoE expression. Regional variability in apoE production appears to vary as a function of the estrogen receptor subtype.

A mutation in protein phosphatase type 2A as a cause of melanoma progression.

The BL6 subline was derived from the F10 line, which was derived from the B16 mouse melanoma cell line. BL6 cells are more invasive than F10 cells and differ genetically from F10 cells by an alteration of the gene encoding the B56gamma regulatory subunit of protein phosphatase 2A (PP2A). This alteration results in the transcription of mRNA encoding a truncated variant of the B56gamma1 isoform (Delta-gamma-1). Delta-gamma-1 is capable of targeting PP2A to the specific subcellular sites but incapable of promoting the dephosphorylation of specific substrates that is normally mediated by the B56gamma subunit-containing PP2A holoenzyme. It thus appears that activities of this type of holoenzymes decrease in cells expressing Delta-gamma-1. Recently, we found two possible ways how Delta-gamma-1 contributes to the enhanced metastatic potential of BL6 cells. The two ways seemed far away from each other: Delta-gamma-1 influenced both the nuclear and cytoplasmic functions of the cell. In the cytoplasm, Delta-gamma-1 localized at the Golgi complex and accelerated Golgi-mediated vesicle transport. On the other hand, Delta-gamma-1 disturbed the cell-cycle regulation. In response to gamma-irradiation, protein levels of Delta-gamma-1 were markedly increased in BL6 cells. Subsequently the integrity of cell-cycle checkpoint became more aberrant in BL6 cells than that in F10 cells. These two actions of Delta-gamma-1 could results in the enhancement of the malignant phenotypes of melanoma cells, as discussed in this review.

IGSF4: a new intercellular adhesion molecule that is called by three names, TSLC1, SgIGSF and SynCAM, by virtue of its diverse function.

Members of the immunoglobulin superfamily often play key roles in intercellular adhesion. IGSF4 is a novel immunoglobulin (Ig)-like intercellular adhesion molecule. Three Ig-like domains are included in the extracellular domain of IGSF4 and mediate homophilic or heterophilic interactions independently of Ca2+. The cytoplasmic domain of IGSF4 contains the binding motifs that connect to actin fibers. Since IGSF4 has been characterized by several independent research groups, this molecule is called by three names, TSLC1, SgIGSF and SynCAM. IGSF4 was first characterized as a tumor suppressor of non-small cell lung cancer and termed TSLC1, although how IGSF4 suppresses tumor growth remains unknown. Silencing of the IGSF4 gene was primarily achieved by allelic loss and promoter methylation in this type of cancers. Soon after this discovery, IGSF4 was found to have roles in adhesion of spermatogenic cells to Sertoli cells and mast cells to fibroblasts and termed SgIGSF. Other researchers revealed that IGSF4 drives synaptic formation of neural cells and termed it SynCAM.

Adenovirus-mediated overexpression of a gene prevents hearing loss and progressive inner hair cell loss after transient cochlear ischemia in gerbils.

The use of adenoviral vectors has recently provided a novel strategy for direct gene transfer into the cochlea. In this study, we assessed the utility of an adenoviral vector expressing glial-cell-derived neurotrophic factor (GDNF) in ischemia-reperfusion injury of the gerbil cochlea. The vector was injected through the round window 4 days before ischemic insult. The distribution of a reporter transgene was confirmed throughout the cochlea from the basal to the apical turn and Western blot analysis indicated significant upregulation of GDNF protein 11 days following virus inoculation. Hearing ability was assessed by sequentially recording compound action potentials (CAP), and the degree of hair cell loss in the organ of Corti was evaluated in specimens stained with rhodamine-phalloidin and Hoechst 33342. On the seventh day of ischemia, the CAP threshold shift and inner hair cell loss were remarkably suppressed in the Ad-GDNF group compared with the control group. These results suggest that adenovirus-mediated overexpression of GDNF is useful for protection against hair cell damage, which otherwise eventually occurs after transient ischemia of the cochlea.