Reg I-knockout mice reveal its role in regulation of cell growth that is required in generation and maintenance of the villous structure of small intestine

Reg I (regenerating gene product I) is a growth factor that plays a central role in the generation and regeneration of the gastric mucosal architecture. On the other hand, mouse Reg I mRNA is expressed at the highest levels in the small intestine among the gastrointestinal tissues. In the current study, with the aim to clarify the role of Reg I protein in the small intestine, the temporal and spatial pattern of Reg I expression and the phenotype of Reg I-knockout mice in the tissue were examined. In the wild-type mice, immunohistochemistry localized Reg I protein expression in absorptive cells located in the lower half of the intestinal villi. Reg I expression was undetectable until embryonic day 13 (E13), when the fetal intestine still lacks villous structure; however, it dramatically increased at E17 along with the formation and maturation of the fetal intestinal villi. In the small intestine of the adult Reg I-knockout mice, less densely packed, round-shaped aberrant morphology of the absorptive cells was observed light microscopically, and electron microscopical examination revealed a strikingly loose connection of these cells to the basement membrane. Antiproliferating cell nuclear antigen staining and anti-Ki67 staining demonstrated the marked decrease in the number of proliferating cells in the small intestinal mucosa of the knockout mice. The cell migration speed visualized by one shot labeling of 5-bromodeoxyuridine was significantly slower in the knockout mice. These phenotypes of Reg I-knockout mice emerged, in accordance with the temporal pattern of Reg I expression described above, from E17. Reg I was considered to be a regulator of cell growth that is required to generate and maintain the villous structure of the small intestine.

Neutralization of interleukin-2 retards the growth of mouse renal cancer

OBJECTIVE

To examine the significance of the thymus and the neutralization of interleukin-2 (IL-2) in treating renal cancer, as the involvement of immunoregulatory cells in tumour development in vivo is well known, naturally occurring CD25+ CD4+ T cells possess potent immunoregulatory functions, and they are of thymic origin dependent on IL-2.

MATERIALS AND METHODS

We first tested activity against mouse renal cell carcinoma (RENCA) cells by adoptively transferring splenocytes of euthymic Balb/c mice depleted of CD25+ cells into athymic Balb/c nude mice bearing established macroscopic RENCA tumours. Second, we tested the anti-RENCA activity in euthymic mice bearing macroscopic RENCA tumours by neutralizing IL-2.

RESULTS

The intravenous administration of CD25+ cell-depleted splenocytes of euthymic Balb/c mice initiated the retardation of macroscopic RENCA tumours subcutaneously established in athymic Balb/c mice. The tumour site showed massive lymphocyte infiltration of mainly CD4+ T cells. By eliminating either the CD4+ cells, CD8+ cells, or natural killer (NK) cells with antibodies after the adoptive transfer of CD25+ cell-depleted splenocytes of euthymic Balb/c mice, macroscopic RENCA tumour retardation was abrogated. The growth of macroscopic RENCA tumour established in euthymic Balb/c mice was also retarded with IL-2 neutralization alone by anti-IL-2 monoclonal antibody (mAb), as well as co-administration of anti-IL-2 mAb and anti-CD25 mAb compared with that of the controls given vehicle. After tumour inoculation, peri- and intratumoral infiltration of CD4+ and CD8+ T cells was very prominent in RENCA tumours in hosts given anti-IL-2 mAb, regardless of the administration of anti-CD25 mAb. Two x 10(5) units of recombinant human IL-2 reverted the retardation of RENCA tumour growth caused by the anti-IL-2 mAb. IL-2 neutralization alone in euthymic Balb/c mice with no tumour inoculation did not suppress splenic CD25+ CD4+ T cells.

CONCLUSION

Both the intravenous administration of CD25+ cell-depleted splenocytes of euthymic Balb/c mice into athymic Balb/c nude mice and IL-2 blocking with anti-IL-2 mAb in euthymic Balb/c mice retarded the growth of macroscopic RENCA tumours in vivo.

Evaluation of modified crystal violet chromoendoscopy procedure using new mucosal pit pattern classification for detection of Barrett's dysplastic lesions

BACKGROUND

Pit pattern diagnosis is important for endoscopic detection of dysplastic Barrett's lesions, though using magnification endoscopy can be difficult and laborious. We investigated the usefulness of a modified crystal violet chromoendoscopy procedure and utilised a new pit pattern classification for diagnosis of dysplastic Barrett's lesions.

METHODS

A total of 1,030 patients suspected of having a columnar lined oesophagus were examined, of whom 816 demonstrated a crystal violet-stained columnar lined oesophagus. The early group of patients underwent 0.05% crystal violet chromoendoscopy, while the later group was examined using 0.03% crystal violet with 3.0% acetate. A targeted biopsy of the columnar lined oesophagus was performed using crystal violet staining after making a diagnosis of closed or open type pit pattern with a newly proposed system of classification. The relationship between type of pit pattern and histologically identified dysplastic Barrett's lesions was evaluated.

RESULTS

Dysplastic Barrett's lesions were identified in biopsy samples with an open type pit pattern with a sensitivity of 96.0%. Further, Barrett's mucosa with the intestinal predominant mucin phenotype was closely associated with the open type pit pattern (sensitivity 81.9%, specificity 95.6%).

CONCLUSIONS

The new pit pattern classification for diagnosis of Barrett's mucosa was found to be useful for identification of cases with dysplastic lesions and possible malignant potential using a crystal violet chromoendoscopic procedure.

Oncolytic herpes simplex virus vector g47delta in combination with androgen ablation for the treatment of human prostate adenocarcinoma

PURPOSE

The use of oncolytic herpes simplex virus type 1 is a promising stategy for cancer treatment. We constructed herpes simplex virus type 1 vector G47Delta by deleting the alpha47 gene and the promoter region of US11 from G207. We now report studies demonstrating the potential of G47Delta as a therapeutic modality for prostate cancer in combination with androgen ablation.

EXPERIMENTAL DESIGN

The cytopathic activities of G47Delta at low multiplicities of infection was tested in human prostate cancer cell lines LNCaP, PC-3, and DU145 in vitro. Two androgen-dependent mouse s.c. tumor models, murine TRAMP and human HONDA, were used to investigate the in vivo efficacy of G47Delta in combination with androgen ablation.

RESULTS

G47Delta at low multiplicities of infection showed more rapid tumor cell killing than G207 in LNCaP and DU145 in vitro and showed a 22-fold higher virus yield in a single-step growth experiment. In vivo, G47Delta treatment resulted in reduced tumor growth of established s.c. TRAMP and HONDA tumors and inhibited the growth of recurrent HONDA tumors that once regressed by androgen ablation therapy. In both TRAMP and HONDA tumor xenografts, the combination therapy of G47Delta with androgen ablation led to significantly enhanced inhibition of the tumor growth and prolonged survival.

CONCLUSIONS

These results suggest that oncolytic virus therapy with G47Delta can be usefully combined with androgen ablation therapy for the treatment of prostate cancer.

Triple combination of oncolytic herpes simplex virus-1 vectors armed with interleukin-12, interleukin-18, or soluble B7-1 results in enhanced antitumor efficacy

Conditionally replicating herpes simplex virus-1 (HSV-1) vectors are promising therapeutic agents for cancer. Insertion of therapeutic transgenes into the viral genome should confer desired anticancer functions in addition to oncolytic activities. Herein, using bacterial artificial chromosome and two recombinase-mediated recombinations, we simultaneously created four "armed" oncolytic HSV-1, designated vHsv-B7.1-Ig, vHsv-interleukin (IL)-12, vHsv-IL-18, and vHsv-null, which express murine soluble B7.1 (B7.1-Ig), murine IL-12, murine IL-18, and no transgene, respectively. These vHsv vectors possess deletions in the gamma34.5 genes and contain the green fluorescent protein gene as a histochemical marker and the immunostimulatory transgene inserted in the deleted ICP6 locus. The vHsv showed similar replicative capabilities in vitro. The in vivo efficacy was tested in A/J mice harboring s.c. tumors of syngeneic and poorly immunogenic Neuro2a neuroblastoma. The triple combination of vHsv-B7.1-Ig, vHsv-IL-12, and vHsv-IL-18 exhibited the highest efficacy among all single vHsv or combinations of two viruses. Combining 1 x 10(5) plaque-forming units each of the three armed viruses showed stronger antitumor activities than any single armed virus at 3 x 10(5) plaque-forming units in inoculated tumors as well as in noninoculated remote tumors. Studies using athymic mice indicated that this enhancement of antitumor efficacy was likely mediated by T-cell immune responses. The combined use of multiple oncolytic HSV-1 armed with different immunostimulatory genes may be a useful strategy for cancer therapy.

Effects of hormone deprivation and 2-methoxyestradiol combination therapy on hormone-dependent prostate cancer in vivo

2-Methoxyestradiol (2-ME) has potent antiproliferative effects on cancer cells. Its utility alone or in combination with other therapies for treating prostate cancer, however, has not been fully explored. Androgen-dependent and independent human prostate cancer cells were examined in vivo for their response to combination therapy. Efficacy was assessed by terminal deoxynucleotide transferase-mediated dUTP nick-end labeling assay and measuring microvessel density (MVD) in excised tumors. Animals harboring hormone-dependent tumors treated with 2-ME alone, androgen deprivation therapy alone, or the combination of the two had a 3.1-fold, 5.3-fold, and 10.1-fold increase in apoptosis, respectively. For hormone-independent tumors, treatment with 2-ME resulted in a 2.43-fold increase in apoptosis and a 73% decrease in MVD. 2-ME was most effective against hormone-dependent tumors in vivo and combination therapy resulted in a significant increase in efficacy compared to no treatment controls and trended toward greater efficacy than either 2-ME or androgen deprivation alone. Combination therapy should be investigated further as an additional therapeutic option for early prostate cancer.

Triple Gene-Deleted Oncolytic Herpes Simplex Virus Vector Double-Armed with Interleukin 18 and Soluble B7-1 Constructed by Bacterial Artificial Chromosome–Mediated System

Conditionally replicating herpes simplex virus type 1 (HSV-1) vectors are promising therapeutic agents for cancer. Certain antitumor functions may be added to oncolytic activities of recombinant HSV-1 vectors by inserting transgenes into the viral genome. Because conventional homologous recombination techniques had required time-consuming processes to create "armed" oncolytic HSV-1 vectors, we established an innovative construction system using bacterial artificial chromosome and two recombinase systems (Cre/loxP and FLPe/FRT). Using G47Delta, a safe and efficacious oncolytic HSV-1 with triple gene mutations, as the backbone, this system allowed a rapid generation of multiple vectors with desired transgenes inserted in the deleted ICP6 locus. Four oncolytic HSV-1 vectors, expressing murine interleukin 18 (mIL-18), soluble murine B7-1 [B7-1-immunoglobulin (B7-1-Ig)], both, or none, were created simultaneously within 3 months. In vitro, all newly created recombinant vectors exhibited virus yields and cytopathic effects similar to the parental G47Delta. In two immunocompetent mouse tumor models, TRAMP-C2 prostate cancer and Neuro2a neuroblastoma, the vector expressing both mIL-18 and B7-1-Ig showed a significant enhancement of antitumor efficacy via T-cell-mediated immune responses. The results show that "arming" with multiple transgenes can improve the efficacy of oncolytic HSV-1 vectors. The use of our system may facilitate the development and testing of various armed oncolytic HSV-1 vectors.

Complete nucleotide sequence of the mitochondrial DNA from Kluyveromyces lactis

The total nucleotide sequence of the mitochondrial genome of the yeast Kluyveromyces lactis was determined. The DNA is a circular molecule of 40,291 base pairs, with 26.1% GC. It contains a set of protein- and RNA-coding genes equivalent to those of the Saccharomyces cerevisiae mitochondrial genome. The genome size is about one half of that of S. cerevisiae mitochondrial DNA. The difference in size is due essentially to a reduced proportion of intergenic and intronic sequences. The coding sequences occupy about one third of the genome, the rest being composed of AT-rich sequences and numerous short GC-rich clusters that are dispersed mostly in the non-coding regions and a few within coding sequences. The presence of these GC clusters is a characteristic feature common to K. lactis and S. cerevisiae mitochondrial DNA, although their sequence patterns are different. The absence of the NADH dehydrogenase subunit genes distinguishes this yeast and S. cerevisiae from the typically aerobic species. The genetic code appears to be that of the standard fungal mitochondrial genomes, with UGA as a tryptophan codon. There are only 22 transfer RNA genes, those corresponding to CUN and CGN codons being missing. CUN codons are absent in the protein-coding sequences. There are five CGN codons within the open reading frames, but they are located exclusively in the introns, rendering them untranslatable. Introns are found only the genes in KlCOX1 and LrRNA. The transcription promoter motif known in S. cerevisiae and several other yeast species is also present. All genes are transcribed from the same strand, except those on a single 7-kilobase pairs segment (EMBL Accession No. AY654900).

Isolation of the mouse Tsll1 and Tsll2 genes, orthologues of the human TSLC1-like genes 1 and 2 (TSLL1 and TSLL2)

We have recently identified the human TSLL1 and TSLL2 genes, which are highly homologous to the human lung tumor suppressor gene, TSLC1. Loss of expression of the TSLL1 or TSLL2 in several cancers suggests that these genes could also act as tumor suppressors. Here, we report the isolation of the mouse orthologous genes, Tsll1 and Tsll2. The Tsll1 and Tsll2 cDNAs contain a single open reading frame of 1188 and 1164 bp encoding a putative immunoglobulin-like cell adhesion molecules of 396 and 388 amino acids, which display 95% and 98% identity with those of human TSLL1 and TSLL2, respectively. The Tsll1 and Tsll2 genes are both composed of nine exons and mapped on mouse chromosome 1q H2-H4 and on 7q A3-B2, respectively, both of which conserve syntenies with human chromosomes 1q and 19q. Like the human TSLL1, the mouse Tsll1 was expressed exclusively in the brain and neurogenic cells, while Tsll1 expression was lost in one of four rodent neuroblastoma cell lines. Tsll2 was expressed in the brain and several organs including the kidney and liver, whereas loss of Tsll2 expression was detected in some rodent cancer cells derived from these tissues. Furthermore, both murine TSLL1 and TSLL2 proteins were expressed on the plasma membrane, especially at the cell-cell attached site. These data, together with their strong conservation during the vertebrate evolution, suggest that TSLL1and TSLL2 could play an important role in cell-cell interaction as well as in tumor suppression.

Association of a lung tumor suppressor TSLC1 with MPP3, a human homologue of Drosophila tumor suppressor Dlg

We have previously identified the tumor suppressor in lung cancer 1 (TSLC1) gene as a novel tumor suppressor in human non-small cell lung cancer (NSCLC) by functional complementation. TSLC1 encodes a membrane glycoprotein belonging to an immunoglobulin superfamily and participates in cell adhesion. A truncating mutation of the TSLC1 corresponding to its cytoplasmic domain in a primary NSCLC tumor suggests that this domain is important for tumor suppressor activity. Here, we report that TSLC1 directly associates with MPP3, one of the human homologues of a Drosophila tumor suppressor gene, Discs large (Dlg). This interaction was dependent on the presence of a PDZ-binding motif at the carboxyl terminus of TSLC1. Furthermore, TSLC1 and MPP3 were colocalized at the cell-cell attachment sites in both a low and a high cell density. The MPP3 gene was expressed in normal lung as well as in many tissues examined except for peripheral blood lymphocytes but lost its expression in one of the nine NSCLC cell lines. These results suggest that TSLC1 and MPP3 are involved in the same cascade of cell-cell interaction, and that the disruption of this cascade might lead cells to malignant growth and tumor formation in lung cancer.

Promoter methylation of the TSLC1 gene in advanced lung tumors and various cancer cell lines

We previously identified TSLC1, a tumor suppressor gene in human nonsmall cell lung cancer (NSCLC). TSLC1 belongs to immunoglobulin superfamily molecules and is involved in cell adhesion. Loss of TSLC1 expression was strongly correlated with the promoter hypermethylation in several NSCLC cell lines. Here, we examined the methylation status of the TSLC1 gene promoter in 48 primary NSCLC tumors by bisulfite SSCP in combination with bisulfite sequencing. Six CpG sites around the promoter regions were significantly methylated in 21 of 48 primary NSCLC tumors (44%). Promoter methylation was more likely to be observed in relatively advanced tumors with TNM classification of pT2, pT3 or pT4 (19 of 33, 58%) than in those with pT1 (2 of 15, 13%), suggesting that alteration of TSLC1 would be involved in the progression of human NSCLC. Loss of TSLC1 expression was also observed in 20 of 46 (43%) human cancer cell lines, including those from esophageal (3 of 3), gastric (8 of 9), ovarian (2 of 5), endometrial (2 of 2), breast (1 of 3), colorectal (2 of 8) and small cell lung cancers (2 of 10). Combined analysis of promoter methylation and the allelic state in these cell lines indicated that the TSLC1 gene was often silenced not only by mono-allelic methylation associated with loss of the other allele but also through bi-allelic methylation. These results suggest that alteration of TSLC1 would be involved in advanced NSCLC as well as in many other human cancers.

Physicochemical and crystal structure analyses of the antidiabetic agent troglitazone

The antidiabetic agent troglitazone has two asymmetric carbons located at the chroman ring and the thiazolidine ring and is produced as a mixture of equal amounts of four optical isomers, 2R-5S, 2S-5R, 2R-5R, and 2S-5S. The crystalline powdered drug substance consists of two diastereomer pairs, 2R-5R/2S-5S and 2R-5S/2S-5R. There are many types of crystals obtained from various crystallization conditions. The X-ray structure analysis and the physicochemical analyses of troglitazone were performed. The solvated crystals of the 2R-5R/2S-5S pair were crystallized from several solutions: methanol, ethanol, acetonitrile, and dichloromethane. The ratio of solvent and troglitazone was 1 : 2 (L1/2-form). The monohydrate crystals were obtained from aqueous acetone solution (L1-form). On the other hand, only an anhydrate crystal of the 2R-5S/2S-5R pair was crystallized from various solutions (H0-form). The dihydrous mixed crystal (MA2-form) was obtained from a mixture of the two diastereomer pairs of 2R-5R/2S-5S and 2R-5S/2S-5R in equal amounts by the slow evaporation of aqueous acetone solution. The crystal structure of the MA2-form is similar to the H0-form. When the MA2 crystal was kept under low humidity, it was converted into the dehydrated form (MA0-form) with retention of the single crystal form. The structure of the MA0-form is isomorphous to the H0-form. The MA2-form was converted into the MA0-form and vice versa with retention of the single crystal under low and high humidity, respectively. The crystallization and storage conditions of the drug substances were successfully analyzed.

The Kluyver effect revisited

Yeast species can grow on various sugars. However, in many cases the growth on certain sugars (especially oligosaccharides) occurs only under aerobic conditions, and not in anaerobiosis or in the absence of respiration. Fermentation is blocked under these conditions. This apparent dependence of sugar utilization on the respiration has been called Kluyver effect, and such 'respiration-dependent' species are called Kluyver effect positive. A yeast may be Kluyver effect positive for some sugars and not for others. The physiological meaning and the molecular basis of the phenomenon are not clear. It has recently been reported that Kluyveromyces lactis, which is Kluyver effect positive for galactose and a few other sugars, could be converted into a Kluyver effect-negative form by introduction of relevant sugar transporter genes. Such results offer for the first time a direct support to the hypothesis that the immediate cause of the Kluyver effect may be the low level of sugar transporter activities which is not sufficient to sustain the high substrate flow necessary for fermentative growth, whereas the energy-efficient respiratory growth does not require a high rate of sugar uptake. We examined to what extent this sugar transporter theory of the Kluyver effect can be generalized.

Engineered IGF-I expression induces glandular enlargement in the murine prostate

IGF-I has been implicated as a factor that may predispose one to prostate cancer and to benign prostatic hypertrophy (BPH). We established murine IGF-I transgenic mice under the control of rat probasin promoter and analysed the histology of the murine IGF-I-overexpressing prostate. Immunohistochemically, IGF-I was expressed in prostatic epithelial cells or basement membranes of the ventral, dorsal and lateral lobes in a line of IGF-I transgenic mice, but not in their control littermates. The anterior lobe did not express IGF-I. IGF-binding protein-3 (IGFBP-3), inhibitory to the mitogenic action of IGF-I, was detected in epithelial cells of prostatic ventral lobes, but not in those of the dorsal, lateral or anterior lobes of IGF-I transgenic mice. In controls, IGFBP-3 was not detected in epithelial cells of any prostatic lobe. Macroscopic prostatic size and the appearance of IGF-I transgenic mice were comparable with those of their control littermates of the same age. With a computed morphometric analysis, epithelial glands and intraglandular lumens in the prostatic lobes except the ventral lobe were smaller at 17 Months of age than at 14 Months both in IGF-I transgenic mice and controls. Glands and intraglandular lumens in the ventral prostatic lobes of IGF-I transgenic mice expressing more IGF-I protein in the prostate than controls were dense and enlarged similar to cysts compared with those of non-transgenic littermates without showing epithelial growth. Glands and lumens in the dorsal and lateral lobes of the IGF-I transgenic mice were also larger than controls at 14 and/or 17 Months of age. Glands in the anterior prostatic lobe of the IGF-I transgenic mice were not morphologically or morphometrically different from those of non-transgenic littermates. In conclusion, IGF-I transgenic mice under the control of rat probasin promoter showed more dense and enlarged epithelial glands in their prostatic ventral, dorsal and lateral lobes.

In Situ Observation of the Four-step Dehydration Process of the 1.BETA.-Methylcarbapenem Antibiotic CS-834 Crystal by X-Rays

The 1 beta-methylcarbapenem antibiotic CS-834 takes six crystalline forms depending on ambient conditions. The X-ray powder diffraction revealed that the dihydrate crystal (B2-form) was changed to the monohydrate (B1-form) through the intermediate form (B2'-form). The monohydrate form was then changed to the dehydrate (B0-form) through the intermediate B1'-form. The progress of the dehydration along the needle axis (c-axis) was observed under a microscope. When a single crystal of the B2-form was mounted on a diffractometer and the humidity was reduced, the crystal was gradually changed to the various dehydration forms with retention of the single crystal. The crystals of B2- to B0-forms form isostructures to each other except the solvent water molecules. In the crystal structure of the B1-form, the pivaloyloxymethyl moiety is disordered. One is nearly similar to that of the B2-form, while another is similar to that of the B0-form. Each crystal structure consists of a columnar arrangement of CS-834 along the c-axis, and the water molecules are located between the columns and form a characteristic hydrogen bond network. When the water molecules leave the crystal, the columns slide slightly following the slight conformational change in the pivaloyloxymethyl groups and are connected by another type of hydrogen bond network. Such a rearrangement of the hydrogen bond network should be a motive force of the phase change to the next step due to the dehydration. Since the hydrogen bond network extends along the c-axis, the dehydration proceeds along the c-axis as observed microscopically.

Physicochemical analyses of phase transition and dehydration processes of a new oral 1beta-methylcarbapenem antibiotic agent, CS-834

The characterizations of the anhydrate (A-form), monohydrate (B1-form), and dihydrate (B2-form) of CS-834 were investigated by powder X-ray diffraction, differential scanning calorimetry (DSC), thermogravimetry-differential thermal analysis (TG-DTA), infrared spectroscopy, and Karl Fischer moisture titration. The typical DSC curve of the B2-form showed five endothermic peaks at 35.0, 46.4, 56.2, 99.2, and 190.4 degrees C and an exothermic peak at 123.4 degrees C. In TG-DTA analysis, the three peaks at 35.0, 46.4, and 56.2 degrees C had a total weight loss of 7.3%, corresponding to the release of two water molecules. From morphological observation under thermomicroscopy, the endothermic peak at 99.2 degrees C was attributed to the melting of the dehydrous crystals (B0-form) and the exothermic peak at 123.4 degrees C to the recrystallization to the A-form crystals. The endothermic peak at 190.4 degrees C was due to the melting of the A-form crystals. After incubation for 6.0 h at 35, 50, 60, and 80 degrees C, the powder X-ray diffraction patterns of the B2-form indicated that it was converted into the A-form via the B1-form and B0-form. Thus CS-834 exists in homologous hydrous crystal forms in multiple-phase transformations with the dehydration of two water molecules.

Direct association of TSLC1 and DAL-1, two distinct tumor suppressor proteins in lung cancer

The tumor suppressor gene TSLC1, which we recently identified in human non-small cell lung cancer, encodes a membrane glycoprotein of the immunoglobulin superfamily. Here, we report that TSLC1 directly associates with DAL-1, a gene product of another lung tumor suppressor belonging to the protein 4.1 family. TSLC1 additionally interacts with the actin filament through DAL-1 at the cell-cell attached site where the complex formation of TSLC1 and DAL-1 is dependent on the integrity of actin cytoskeleton. Redistribution of both TSLC1 and DAL-1 to the newly generated membrane ruffling areas suggests that these proteins are also involved in cell motility accompanying the actin rearrangement. Furthermore, restoration of TSLC1 expression strongly suppressed the metastasis of a human non-small cell lung cancer cell line, A549, from the spleen to the liver in nude mice. These findings, together with frequent loss of their expression in lung cancers, suggest that TSLC1 and DAL-1 play a critical role in the same pathway involved in the suppression of lung tumor formation and metastasis.

Relationship between perfectionism, personality disorders and agoraphobia in patients with panic disorder

OBJECTIVE

In earlier reports, we found that perfectionism might be involved in the development and/or maintenance of agoraphobia in panic disorder. The present report extends this work by examining the relationship between perfectionism and comorbidity with personality disorders in panic disorder patients with agoraphobia (PDA) and those without agoraphobia (PD).

METHOD

We examined comorbidity of personality disorders by Structured Clinical Interview for DSM-III-R Personality Disorders (SCID-II) and assessed perfectionism using multidimensional perfectionism scale in 56 PDA and 42 PD patients.

RESULTS

The PDA group met criteria for at least one personality disorder significantly more often than the PD group. With stepwise regression analyses, avoidant and obsessive-compulsive personality disorders emerged as significant indicators of perfectionism in patients with panic disorder.

CONCLUSION

These findings suggest that perfectionism in panic disorder patients may be more common in those with comorbid personality disorders, and may be an important target for preventive and therapeutic efforts.

The tumor suppressor protein TSLC1 is involved in cell-cell adhesion

TSLC1 is a tumor suppressor gene encoding a member of the immunoglobulin (Ig) superfamily. The significant homology of its extracellular domain with those of other Ig superfamily cell adhesion molecules (IgCAMs) has raised the possibility that TSLC1 participates in cell-cell interactions. In this study, the physiological properties of TSLC1 were investigated in Madin-Darby canine kidney (MDCK) cells expressing TSLC1 tagged with green fluorescent protein (GFP) as well as in the cells that express endogenous TSLC1. Biochemical analysis has revealed that TSLC1 is an N-linked glycoprotein with a molecular mass of 75 kDa and that it forms homodimers through cis interaction within the plane of the cell membranes. Confocal laser scanning microcopy of the cells expressing TSLC1 showed the localization patterns characteristic to adhesion molecules. At the beginning of cell attachment, TSLC1 accumulated in interdigitated structures at cell-cell boundaries, but, when cells reached a confluence, TSLC1 was distributed all along the cell membranes. In polarized cells, TSLC1 was recruited to the lateral membrane, implying trans interaction of TSLC1 between neighboring cells. In support of this notion, MDCK cells expressing TSLC1-GFP showed a significant level of cell aggregation in the absence or presence of Ca(2+) and Mg(2+). Taken together, these results indicate that TSLC1 mediates intracellular adhesion through homophilic interactions in a Ca(2+)/Mg(2+)-independent manner.

Identification of the Tslc1 gene, a mouse orthologue of the human tumor suppressor TSLC1 gene

We have recently identified the TSLC1 gene as a novel tumor suppressor in human non-small lung cancer on chromosome 11q23.2. TSLC1 encodes a membrane glycoprotein showing significant homology with immunoglobulin superfamily molecules. Here, we report the isolation of a mouse orthologous gene, Tslc1. The Tslc1 cDNA contains a single open reading frame of 1335 bp encoding a putative protein of 445 amino acids, and its expression was detected in all tissues examined. The Tslc1 gene is mapped on mouse chromosome 9, a synteny of human chromosome 11q, and is composed of ten exons, the exon-intron junctions being highly conserved between human and mouse. The predicted amino acids of mouse Tslc1 display 98% identity with that of human TSLC1. Furthermore, data base analysis indicates that the amino acid sequences corresponding to the cytoplasmic domain of Tslc1 are identical in five mammals and highly conserved in vertebrates, suggesting an important role of Tslc1 in normal cell-cell interaction.