Immunogold localization of inositol 1, 4, 5-trisphosphate (InsP3) receptor in mouse cerebellar Purkinje cells using three monoclonal antibodies

Ultrastructural localization of InsP3 receptor in mouse cerebellar Purkinje cells was investigated by immunogold technique using three monoclonal antibodies (mab 10A6, 4C11 and 18A10). The epitopes of the three antibodies were numerously detected on the smooth endoplasmic reticulum (ER) (especially, on the stacks of flattened smooth ER, subsurface cisterns and spine apparatus), scantily on the rough ER and on the outer nuclear membrane, but were not detectable on either the plasmalemma, synaptic densities, mitochondria or Golgi apparatus. Not only mab 4C11 and 10A6 which bind to the N-terminal region of the receptor but also 18A10 which binds to the C-terminal region were localized on the cytoplasmic surface of the ER membranes. This indicates that the C terminus of InsP3 receptor is localized on the cytoplasmic surface of the ER. We noticed that gold particles are usually localized on the fuzzy structure of the cytoplasmic surface of smooth ER, which is suggested to correspond to the feet structure of the ryanodine receptor. In the Nissl body, gold particles were found not only on the ER membranes but also in the cytoplasmic matrix between the rough ER cisterns. We suggest that the peculiar structure of Nissl body, which is composed of parallel cisterns of rough ER, sandwiching a number of free polyribosomes between the cisternal elements, is due to the fact that the major proteins like InsP3 receptor are synthesized mostly on the free polyribosomes and become membrane bound only at the later stage of the biosynthesis.

No lengthening of life span in mice continuously exposed to gamma rays at very low dose rates

Late effects of continuous exposure to ionizing radiation are potential hazards to workers in radiation facilities as well as to the general public. Recently, low-dose-rate and low-dose effects have become a serious concern. Using a total of 4000 mice, we studied the late biological effects of chronic exposure to low-dose-rate radiation as assayed by life span. Two thousand male and 2000 female 8-week-old specific-pathogen-free (SPF) B6C3F1 mice were randomly divided into four groups (one nonirradiated control and three irradiated). Irradiation was carried out for approximately 400 days using (137)Cs gamma rays at dose rates of 21 mGy day(-1), 1.1 mGy day(-1) and 0.05 mGy day(-1) with total doses equivalent to 8000 mGy, 400 mGy and 20 mGy, respectively. All mice were kept under SPF conditions until they died spontaneously. Statistical analyses showed that the life spans of mice of both sexes irradiated with 21 mGy day(-1) (P < 0.0001) and of females irradiated with 1.1 mGy day(-1) (P < 0.05) were significantly shorter than those of the control group. Our results show no evidence of lengthened life span in mice continuously exposed to very low dose rates of gamma rays.

Cause of Death and Neoplasia in Mice Continuously Exposed to Very Low Dose Rates of Gamma Rays

Four thousand 8-week-old SPF B6C3F1 mice (2000 of each sex) were divided into four groups, one nonirradiated (control) and three irradiated. The irradiated groups were exposed to (137)Cs gamma rays at dose rates of 21, 1.1 and 0.05 mGy day(-1) for approximately 400 days with total doses equivalent to 8000, 400 and 20 mGy, respectively. All mice were kept until natural death, and pathological examination was performed to determine the cause of death. Neoplasms accounted for >86.7% of all deaths. Compared to the nonirradiated controls, the frequency of myeloid leukemia in males, soft tissue neoplasms and malignant granulosa cell tumors in females, and hemangiosarcoma in both sexes exposed to 21 mGy day(-1) were significantly increased. The number of multiple primary neoplasms per mouse was significantly increased in mice irradiated at 21 mGy day(-1). Significant increases in body weights were observed from 32 to 60 weeks of age in males and females exposed to 1.1 mGy day(-1) and 21 mGy day(-1), respectively. Our results suggest that life shortening (Tanaka et al., Radiat. Res. 160, 376-379, 2003) in mice continuously exposed to low-dose-rate gamma rays is due to early death from a variety of neoplasms and not from increased incidence of specific neoplasms.

Intraoperative radiotherapy for advanced carcinoma of the pancreas

A detailed retrospective analysis of the efficacy of intraoperative radiotherapy (IOR) in advanced carcinoma of the pancreas is presented. During a 10-year period from 1973 through 1982, 70 patients with advanced carcinoma of the pancreas were treated by multimodal methods, separate or combined therapy of surgery, IOR, and chemotherapy in two different institutions. Among these, 33 patients underwent IOR, mostly combined with additive surgery. A single dose of 20.1 to 40.0 Gy with 8 to 25 meV electrons was delivered through radiation cones ranging from 6 to 10 cm in diameter. Excellent relief was noticed in 50% of the patients who had complained of pain. Among Stage IV patients, a significant difference of survival rate was observed between IOR and control groups (P less than 0.05); the mean survival time of the IOR group was 4.6 +/- 2.6 (SD) and that of the control group 2.5 +/- 1.4 (SD) months. Intraoperative radiotherapy proved to be effective in prolonging the survival of patients with advanced stage of the lesion.

Chromosomal instability associated with global DNA hypomethylation is associated with the initiation and progression of esophageal squamous cell carcinoma

BACKGROUND

Global DNA hypomethylation is associated with increased chromosomal instability and plays an important role in tumorigenesis. The methylation status of the long interspersed nuclear element-1 (LINE-1) element is a useful surrogate marker for global DNA methylation. Although LINE-1 hypomethylation is recognized as a poor prognostic marker, the correlation of LINE-1 methylation level with tumor suppressor gene mutation, chromosomal instability, and clinical significance in esophageal squamous cell carcinoma (ESCC) remains unclear.

METHODS

Using resected tumor tissues and the corresponding normal esophageal mucosa from 105 patients with ESCC, bisulfite pyrosequencing analysis was performed to quantify the LINE-1 methylation levels. p53 mutations in exons two to ten were detected by polymerase chain reaction direct sequencing. Chromosomal instability was assessed by single nucleotide polymorphism array comparative genomic hybridization analysis.

RESULTS

The LINE-1 methylation level of ESCC was significantly lower than matched normal mucosa. LINE-1 methylation levels of normal mucosa from the esophagus had a significant inverse correlation with both cigarette smoking and alcohol consumption of the study subjects. LINE-1 hypomethylation of ESCC was significantly associated with lymph node metastasis, lymphovascular invasion, the frequency of p53 mutation and poor survivability. The LINE-1 methylation levels in ESCC had a significant inverse association with the percentage of copy number alterations in the whole genome, mirroring chromosomal instability.

CONCLUSIONS

Our results suggested that whole genome hypomethylation caused by chronic inflammation could initiate carcinogenesis of esophageal squamous cells through chromosomal instability. In addition, chromosomal instability associated with the global hypomethylation might correlate highly with the progression of ESCC.

Discrimination of p53 immunohistochemistry-positive tumors by its staining pattern in gastric cancer

Immunohistochemistry staining of p53 is a cheap and simple method to detect aberrant function of p53. However, there are some discrepancies between the result of immunohistochemistry staining and mutation analysis. This study attempted to find a new definition of p53 staining by its staining pattern. Immunohistochemistry staining of p53 and TP53 gene mutation analysis were performed in 148 gastric cancer patients. Also SNP-CGH array analysis was conducted to four cases. Positive staining of p53 was observed in 88 (59.5%) tumors. Tumors with positive p53 staining showed malignant features compared to negative tumors. Mutation of TP53 gene was observed in 29 (19.6%) tumors with higher age and differentiated type. In positive p53 tumors, two types could be distinguished; aberrant type and scattered type. With comparison to TP53 gene mutation analysis, all the scattered type had wild-type TP53 gene (P = 0.0003). SNP-CGH array showed that scattered-type tumors had no change in the structure of chromosome 17. P53-scattered-type staining tumors may reflect a functionally active nonmutated TP53 gene. In interpretation of p53 immunohistochemistry staining, distinguishing p53-positive tumors by their staining pattern may be important in gastric cancer.

Stacks of flattened smooth endoplasmic reticulum highly enriched in inositol 1,4,5-trisphosphate (InsP3) receptor in mouse cerebellar Purkinje cells

By immunogold electron microscopy we have shown that in mouse cerebellar Purkinje cells fixed by perfusion with formaldehyde-glutaraldehyde solution, the InsP3 receptor are numerously detected on the stacks of flattened cisterns (OTSU et al, (1990) Cell Struct. Funct., 15: 163-173). In the present experiment we investigated distribution, structure and properties of the stacks by conventional electronmicroscopy, lectin cytochemistry and immunoelectron microscopy. The size and number of stacks were variable depending on their intracellular localization; short stacks with 2-4 parallel cisterns predominate in the perikaryon, long stacks with 4-15 cisterns in the proximal dendrite, and long stacks with 3-4 cisterns in the distal dendrites. The flattened cisterns bind with concanavalin A but not with wheat-germ agglutinin and may contain KDEL proteins loaded with Lys-Asp-Glu-Leu at their C-terminin in their lumens, indicating that the cisterns are derived from ER membranes. The electron dense materials sandwiched between the cisternal membranes are composed of small particles, short cylindrical in shape and approximately 20 nm in diameter, and markedly labeled with anti InsP3R antibody. We suggest that they correspond to the tetramer of the InsP3R or their related molecules. It is not clear whether the stacks of flattened cisterns exist per se in the Purkinje cells or smooth ER existing in singlet in vivo in the Purkinje cells forms stacks during fixation. It is strongly suggested, however, that the smooth ER membranes covered by the InsP3R or their related molecules can easily interact and stack each other in the Purkinje cells.

Clinical significance of surgical resection for the recurrence of esophageal cancer after radical esophagectomy

BACKGROUND

This study aimed to clarify the clinical significance of surgical resection for recurrent lesions after esophagectomy for esophageal cancer.

METHODS

Recurrence was detected in 113 of 365 consecutive patients who underwent surgical resection for esophageal cancer, and some treatment was performed for recurrence in 100 of the 113 patients. The treatments were classified into two groups: chemotherapy and/or radiation with surgery (surgery group, n = 14) and chemotherapy and/or radiation without surgery (no surgery group, n = 86). The outcomes were retrospectively analyzed.

RESULTS

Of the 14 patients in the surgery group, 3 underwent repeated resection. Thus, a total of 22 resections were performed for these patients. The resected organs were the lymph nodes in nine patients, the lungs in six patients, local recurrence in two patients, subcutaneous recurrence in two patients, the liver in one patient, the brain in one patient, and the parotid gland in one patient. Among the 22 recurrent cases, 20 involved solitary lesions or multiple lesions located in a small resectable region. When the two groups were compared, the surgery group showed a more favorable prognosis in terms of both survival after esophagectomy (median survival time, 103.3 vs 23.1 months; p = 0.0060) and survival after initial recurrence (92.1 vs 12.2 months; p = 0.0057).

CONCLUSIONS

Multimodal treatment provides a significant benefit for patients with recurrence after esophagectomy for esophageal cancer. Surgical intervention should be aggressively included in the treatment strategy when the recurrent lesion is solitary or localized.

Observation of strong low-lying E1 strength in the two-neutron halo nucleus 11Li

An exclusive measurement has been made of the Coulomb dissociation of the two-neutron halo nucleus 11Li at 70 MeV/nucleon at RIKEN. Strong low-energy (soft) E1 excitation is observed, peaked at about Ex = 0.6 MeV with B(E1) = 1.42(18) e2fm2 for Erel < or = 3 MeV, which was largely missed in previous measurements. This excitation represents the strongest E1 transition ever observed at such low excitation energies. The spectrum is reproduced well by a three-body model with a strong two-neutron correlation, which is further supported by the E1 non-energy-weighted cluster sum rule.

Associations of single nucleotide polymorphisms in precursor-microRNA (miR)-125a and the expression of mature miR-125a with the development and prognosis of autoimmune thyroid diseases

It is important to search the biomarker to predict the development and prognosis of autoimmune thyroid diseases (AITDs) such as Hashimoto's disease (HD) and Graves' disease (GD). MicroRNA (miR) bind directly to the 3' untranslated region of specific target mRNAs to suppress the expression of proteins, promote the degradation of target mRNAs and regulate immune response. miR-125a is known to be a negative regulator of regulated upon activation normal T cell expressed and secreted (RANTES), interleukin (IL)-6 and transforming growth factor (TGF)-β; however, its association with AITDs remains unknown. To clarify the association between AITDs and miR-125a, we genotyped the rs12976445 C/T, rs10404453 A/G and rs12975333 G/T polymorphisms in the MIR125A gene, which encodes miR-125a, using direct sequencing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods in 155 patients with GD, 151 patients with HD and 118 healthy volunteers. We also examined the expression of miR-125a in peripheral blood mononuclear cells (PBMCs) from 55 patients with GD, 79 patients with HD and 38 healthy volunteers using quantitative real-time PCR methods. We determined that the CC genotype and C allele of the rs12976445 C/T polymorphism were significantly more frequent in patients with HD compared with control subjects (P < 0·05) and in intractable GD compared with GD in remission (P < 0·05). The expression of miR-125a was correlated negatively with age (P = 0·0010) and down-regulated in patients with GD compared with control subjects (P = 0.0249). In conclusion, miR-125a expression in PBMCs and the rs12976445 C/T polymorphism were associated with AITD development and prognosis.

Gastric Cancer Patients with High PLK1 Expression and DNA Aneuploidy Correlate with Poor Prognosis

Gastric cancer is the fourth most common cancer worldwide. Although it is important to identify patients at high risk for a poor outcome, factors correlating with prognosis in gastric cancer are largely unknown. Here, we focus on the correlations among expression of Polo-like kinase 1 (PLK1), DNA ploidy, and clinical outcome in gastric cancer patients. Gastric cancer specimens were analyzed from 207 consecutive patients. Patients were classified into two groups according to tumor PLK1 expression and DNA content, and an analysis of their clinical outcomes was carried out. Prognoses of patients with PLK1-high tumors were worse than those of patients with PLK1-low tumors, but the differences were not statistically significant. In cell lines, overexpression of PLK1 induced centrosome amplification and multipolar spindles, potentially leading to DNA aneuploidy. Indeed, high expression of PLK1 was also associated with DNA aneuploidy in clinical gastric cancer specimens. Patients with both high PLK1 expression and DNA aneuploidy had poor recurrence-free survival, whereas PLK1 expression and DNA ploidy status alone were not significantly associated with outcome. Here, we provide clinical evidence that high expression of PLK1 could have detrimental effects in tumors with DNA aneuploidy, which may increase the risk of recurrence in gastric cancer patients.

Mitotic checkpoint regulator RAE1 promotes tumor growth in colorectal cancer

Microtubules are among the most successful targets for anticancer therapy because they play important roles in cell proliferation as they constitute the mitotic spindle, which is critical for chromosome segregation during mitosis. Hence, identifying new therapeutic targets encoding proteins that regulate microtubule assembly and function specifically in cancer cells is critical. In the present study, we identified a candidate gene that promotes tumor progression, ribonucleic acid export 1 (RAE1), a mitotic checkpoint regulator, on chromosome 20q through a bioinformatics approach using datasets of colorectal cancer (CRC), including The Cancer Genome Atlas (TCGA). RAE1 was ubiquitously amplified and overexpressed in tumor cells. High expression of RAE1 in tumor tissues was positively associated with distant metastasis and was an independent poor prognostic factor in CRC. In vitro and in vivo analysis showed that RAE1 promoted tumor growth, inhibited apoptosis, and promoted cell cycle progression, possibly with a decreased proportion of multipolar spindle cells in CRC. Furthermore, RAE1 induced chemoresistance through its anti-apoptotic effect. In addition, overexpression of RAE1 and significant effects on survival were observed in various types of cancer, including CRC. In conclusion, we identified RAE1 as a novel gene that facilitates tumor growth in part by inhibiting apoptosis and promoting cell cycle progression through stabilizing spindle bipolarity and facilitating tumor growth. We suggest that it is a potential therapeutic target to overcome therapeutic resistance of CRC.

Surgical resection for esophageal cancer synchronously or metachronously associated with head and neck cancer

BACKGROUND

Esophageal cancer is frequently associated with head and neck cancer, and esophagectomy is usually difficult in such a case. The purpose of this study was to clarify the clinical significance of esophagectomy for patients with esophageal cancer associated either synchronously or metachronously with head and neck cancer.

METHODS

The clinical outcomes of surgical resections for esophageal cancer were compared between 26 patients with head and neck cancer (double cancer group) and 176 without head and neck cancer (control group).

RESULTS

Staged operations were performed in 5 patients in the double cancer group, while microvascular anastomosis as well as a muscle flap was added for 3 and 4 patients, respectively. The mortality and morbidity of the double cancer group were 0 and 35 %, respectively, which were not significantly different from those of the control group (3 and 31 %, respectively). There were no significant differences in overall survival in the double cancer and control groups, which had 5-year survival rates of 59 and 49 %, respectively.

CONCLUSIONS

Esophagectomy can be an effective treatment when techniques are adopted that are appropriate for each case, such as staged operations, muscular flaps, and microvascular anastomosis, even in patients with double cancers of the esophagus and the head and neck.

Location of the Neutron Dripline at Fluorine and Neon

A search for the heaviest isotopes of fluorine, neon, and sodium was conducted by fragmentation of an intense ^{48}Ca beam at 345  MeV/nucleon with a 20-mm-thick beryllium target and identification of isotopes in the large-acceptance separator BigRIPS at the RIKEN Radioactive Isotope Beam Factory. No events were observed for ^{32,33}F, ^{35,36}Ne, and ^{38}Na and only one event for ^{39}Na after extensive running. Comparison with predicted yields excludes the existence of bound states of these unobserved isotopes with high confidence levels. The present work indicates that ^{31}F and ^{34}Ne are the heaviest bound isotopes of fluorine and neon, respectively. The neutron dripline has thus been experimentally confirmed up to neon for the first time since ^{24}O was confirmed to be the dripline nucleus nearly 20 years ago. These data provide new keys to understanding the nuclear stability at extremely neutron-rich conditions.

Nucleus ^{26}O: A Barely Unbound System beyond the Drip Line

The unbound nucleus ^{26}O has been investigated using invariant-mass spectroscopy following one-proton removal reaction from a ^{27}F beam at 201  MeV/nucleon. The decay products, ^{24}O and two neutrons, were detected in coincidence using the newly commissioned SAMURAI spectrometer at the RIKEN Radioactive Isotope Beam Factory. The ^{26}O ground-state resonance was found to lie only 18±3(stat)±4(syst)  keV above threshold. In addition, a higher lying level, which is most likely the first 2^{+} state, was observed for the first time at 1.28_{-0.08}^{+0.11}  MeV above threshold. Comparison with theoretical predictions suggests that three-nucleon forces, pf-shell intruder configurations, and the continuum are key elements to understanding the structure of the most neutron-rich oxygen isotopes beyond the drip line.

Effect of EGFR and p-AKT Overexpression on Chromosomal Instability in Gastric Cancer

BACKGROUND

Molecular profiling in gastric cancer (GC) is important for diagnosis and treatment. In this study, we investigated signal transduction pathways that might induce chromosomal instability in GC.

METHODS

Epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), and p-AKT expression were analyzed using immunohistochemistry, and chromosomal instability was assessed by DNA aneuploidy using laser scanning cytometry, in a total of 202 GC cases.

RESULTS

The rate of EGFR expression and p-AKT expression was 70.3 and 34.2 %, respectively, in GC patients. In total, 57.5 % of GC patients exhibited DNA aneuploidy, and p-AKT positively correlated with EGFR and HER2 (p = 0.0127 and p = 0.00031, respectively). Patients with EGFR overexpressing GC showed shorter disease-specific survival than the other cases (hazard ratio 2.00, 95 % confidence interval 1.19-3.53; p = 0.0104). Moreover, EGFR and p-AKT expression was significantly correlated with DNA aneuploidy (p = 0.0002 and p = 0.0302, respectively).

CONCLUSIONS

Our data showed that both EGFR and p-AKT overexpression were clearly associated with DNA aneuploidy. Aneuploidy could be a useful marker for therapies that target EGFR.

Discovery of ^{60}Ca and Implications For the Stability of ^{70}Ca

The discovery of the important neutron-rich nucleus _{20}^{60}Ca_{40} and seven others near the limits of nuclear stability is reported from the fragmentation of a 345  MeV/u ^{70}Zn projectile beam on ^{9}Be targets at the radioactive ion-beam factory of the RIKEN Nishina Center. The produced fragments were analyzed and unambiguously identified using the BigRIPS two-stage in-flight separator. The eight new neutron-rich nuclei discovered, ^{47}P, ^{49}S, ^{52}Cl, ^{54}Ar, ^{57}K, ^{59,60}Ca, and ^{62}Sc, are the most neutron-rich isotopes of the respective elements. In addition, one event consistent with ^{59}K was registered. The results are compared with the drip lines predicted by a variety of mass models and it is found that the models in best agreement with the observed limits of existence in the explored region tend to predict the even-mass Ca isotopes to be bound out to at least ^{70}Ca.

Probing the Symmetry Energy with the Spectral Pion Ratio

Many neutron star properties, such as the proton fraction, reflect the symmetry energy contributions to the equation of state that dominate when neutron and proton densities differ strongly. To constrain these contributions at suprasaturation densities, we measure the spectra of charged pions produced by colliding rare isotope tin (Sn) beams with isotopically enriched Sn targets. Using ratios of the charged pion spectra measured at high transverse momenta, we deduce the slope of the symmetry energy to be 42<L<117  MeV. This value is slightly lower but consistent with the L values deduced from a recent measurement of the neutron skin thickness of ^{208}Pb.

Oxysterol binding protein-like 3 (OSBPL3) is a novel driver gene that promotes tumor growth in part through R-Ras/Akt signaling in gastric cancer

Gastric cancer (GC) is one of the most lethal malignant tumors. To improve the prognosis of GC, the identification of novel driver genes as therapeutic targets is in urgent need. Here, we aimed to identify novel driver genes and clarify their roles in gastric cancer. OSBPL3 was identified as a candidate driver gene by in silico analysis of public genomic datasets. OSBPL3 expression was analyzed by RT-qPCR and immunohistochemistry in GC cells and tissues. The biological functions and mechanisms of OSBPL3 in GC were examined in vitro and in vivo using GC cells. The association between OSBPL3 expression and clinical outcome in GC patients was also evaluated. Overexpression of OSBPL3 was detected in GC cells with OSBPL3 DNA copy number gains and promoter hypomethylation. OSBPL3-knockdown reduced GC cell growth in vitro and in vivo by inhibiting cell cycle progression. Moreover, an active Ras pull-down assay and western blotting demonstrated that OSBPL3 activates the R-Ras/Akt signaling pathway in GC cells. In a clinical analysis of two GC datasets, high OSBPL3 expression was predictive of a poor prognosis. Our findings suggest that OSBPL3 is a novel driver gene stimulating the R-Ras/Akt signaling pathway and a potential therapeutic target in GC patients.

Persistence of the Z=28 Shell Gap Around ^{78}Ni: First Spectroscopy of ^{79}Cu

In-beam γ-ray spectroscopy of ^{79}Cu is performed at the Radioactive Isotope Beam Factory of RIKEN. The nucleus of interest is produced through proton knockout from a ^{80}Zn beam at 270  MeV/nucleon. The level scheme up to 4.6 MeV is established for the first time and the results are compared to Monte Carlo shell-model calculations. We do not observe significant knockout feeding to the excited states below 2.2 MeV, which indicates that the Z=28 gap at N=50 remains large. The results show that the ^{79}Cu nucleus can be described in terms of a valence proton outside a ^{78}Ni core, implying the magic character of the latter.

Relative biological effectiveness of carbon ions for causing fatal liver failure after partial hepatectomy in mice

To evaluate the acute phase damage to liver by carbon ions, BALB/c mice were irradiated with carbon ions or X-rays after two-thirds partial hepatectomy, and their survival was followed. The 50% lethal dose within 60 days (LD50/60) was 42.2 +/- 0.25 Gy (standard error) for X-rays, and 22.7 +/- 0.25 Gy for carbon ions. The relative biological effectiveness (RBE) of carbon ions was 1.86 (95% confident limits: 1.69-2.04) as calculated from the LD50/60. Mice irradiated at much higher doses, 60 Gy of X-rays or 24 Gy of carbon ions, showed significantly higher serum ammonia levels and lower serum albumin levels than normal, suggesting hepatic failure as a cause of death. Hepatocytes showed karyorrhexis and karyolysis in carbon ion irradiated and spotty necrosis in X-ray irradiated mice, suggesting nuclear damage. Mice irradiated with LD50 of X-rays or carbon ions had a remarkably lower bromodeoxyuridine (BrdU) labeling index and mitotic index than control. Treatments with both BrdU and vincristine showed that none of the hepatocytes that synthesized DNA after irradiation completed mitosis, indicating G2 arrest. The liver weight of irradiated mice significantly decreased depending on the dose. Carbon ions as well as X-rays damaged hepatocytes directly and suppressed liver regeneration leading to fatal liver failure.

Cancer-associated Fibroblast-derived Spondin-2 Promotes Motility of Gastric Cancer Cells

BACKGROUND/AIM

Peritoneal dissemination (PD) occurs frequently in gastric cancer (GC) and is fatal. The interactions between tumor cells and stromal cells are critical for cancer progression. Our aim was to identify a novel PD-associated gene derived from stromal cells in GC.

MATERIALS AND METHODS

Among the candidate PD-associated genes identified in our previous study, we focused on spondin-2 (SPON2), an extracellular matrix-secreted protein. Clinicopathological and prognostic analyses of SPON2 mRNA expression were performed using GC datasets. Localization of SPON2 expression was assessed by immunohistochemistry. In vitro migration assay and immunofluorescence staining were also conducted using GC cell lines.

RESULTS

SPON2 was expressed in and secreted from cancer-associated fibroblasts in GC. High expression of SPON2 in tumor tissues was correlated with PD, tumor size and poor prognosis in GC. The motility of GC cells was increased by treatment with a SPON2 recombinant protein in vitro.

CONCLUSION

Cancer-associated fibroblast-derived SPON2 may promote PD, in part, by facilitating GC cell motility and serve as a predictive marker for PD in GC.

Halo structure of the island of inversion nucleus 31Ne

The cross sections for single-neutron removal from the very neutron-rich nucleus 31Ne on Pb and C targets have been measured at 230 MeV/nucleon using the RIBF facility at RIKEN. The deduced large Coulomb breakup cross section of 540(70) mb is indicative of a soft E1 excitation. Comparison with direct-breakup model calculations suggests that the valence neutron of 31Ne occupies a low-l orbital (most probably 2p(3/2)) with a small separation energy (S(n) approximately < 0.8 MeV), instead of being predominantly in the 1f(7/2) orbital as expected from the conventional shell ordering. These findings suggest that 31Ne is the heaviest halo system known.