Capillary-driven horseshoe vortex forming around a micro-pillar

HYPOTHESIS

Horseshoe vortices are known to emerge around large-scale obstacles, such as bridge pillars, due to an inertia-driven adverse pressure gradient forming on the upstream-side of the obstacle. We contend that a similar flow structure can arise in thin-film Stokes flow around micro-obstacles, such as used in textured surfaces to improve wettability. This could be exploited to enhance mixing in microfluidic devices, typically limited to creeping-flow regimes.

EXPERIMENTS

Numerical simulations based on the Navier-Stokes equations are carried out to elucidate the flow structure associated with the wetting dynamics of a liquid film spreading around a 50 μm diameter micro-pillar. The employed multiphase solver, which is based on the volume of fluid method, accurately reproduces the wetting dynamics observed in current and previous (Mu et al., Langmuir, 2019) experiments.

FINDINGS

The flow structure within the liquid meniscus forming at the foot of the micro-pillar evinces a horseshoe vortex wrapping around the obstacle, notwithstanding that the Reynolds number in our system is extremely low. Here, the adverse pressure gradient driving flow reversal near the bounding wall is caused by capillarity instead of inertia. The horseshoe vortex is entangled with other vortical structures, leading to an intricate flow system with high-potential mixing capabilities.

A nationwide survey on gynecologic endoscopic surgery in Japan, 2014-2016

AIM

Since 2014, Japan Society of Gynecologic and Obstetric Endoscopy and minimally invasive therapy (JSGOE) conducted a nationwide survey on gynecologic endoscopic surgery. We aimed to evaluate the current status and complications associated with endoscopic surgery by Japan gynecologic and obstetric endoscopy-database registry system (JOE-D).

METHODS

Electrical medical records concerning the endoscopic surgery were generated from the daily use of reporting system. The subjects were all patients who underwent gynecologic endoscopic surgery. In addition to assessment of actual numbers, diagnosis, and operative methods, adverse events were registered.

RESULTS

Total 203 970 patients performed laparoscopic, hysteroscopic and falloposcopic surgery for 3 years, 2014-2016. The numbers of endoscopic surgeries conducted in 2016 were increased more than 67 000, 13 000 or 450 cases, respectively. Incidence rates of complications involving these three types of surgeries in each year were approximately 3.1%. Incidences of intraoperative complications were relatively high in malignant diseases, laparoscopic-assisted vaginal hysterectomy (LAVH) and myomectomy (LAM). In total laparoscopic hysterectomy/laparoscopic hysterectomy (TLH/LH) performed from 2014 to 2016, ureteral injury as intra and postoperative complication occurred in 0.35%. In the past 3 years, the rates of vascular injury, urinary tract, and bowel injury as intraoperative complications caused by laparoscopic surgery were approximately 0.1%. In the hysteroscopic surgery, the rates of total intra- and postoperative complications were 0.78%.

CONCLUSION

We exhibited the current status by the nationwide survey of gynecologic endoscopic surgery all over Japan. Severe intra or postoperative complications were identified over the 3 years at a rate of 0.04%.

Serum CA 125 Level after Neoadjuvant Chemotherapy is Predictive of Prognosis and Debulking Surgery Outcomes in Advanced Epithelial Ovarian Cancer

Recently, neoadjuvant chemotherapy followed by interval debulking surgery (NACT-IDS) has been recommended for selected patients with International Federation of Gynecology and Obstetrics (FIGO) stage III or IV disease and bulky tumors. The aim of this study was to evaluate associations between post-NACT serum CA 125 levels, surgical outcomes, and clinical outcomes in patients with advanced epithelial ovarian cancer. We retrospectively analyzed 107 patients with FIGO stage III or IV ovarian cancer who were treated with NACT-IDS at the Gynecology Department of Kanagawa Cancer Center between January 2001 and December 2012. Serum CA 125 levels after NACT were significantly lower in the complete/optimal IDS group compared to the suboptimal IDS group (mean±standard deviation: 48.1±27.6 vs. 346.5±295.2 U/mL, p<0.01). Patients with low preoperative CA 125 levels (<35 U/mL) had a higher probability of optimal IDS (78.1±41.9% vs. 33.3±19.2%, p<0.01) and longer progression-free survival (mean±standard deviation: 30.4±14.3 months vs. 21.3±7.3 months, p<0.05) than patients with high CA 125 levels (>100 U/mL). Patients with low CA 125 levels (<35 U/mL) had a higher probability of complete/optimal IDS and longer progression-free survival compared to patients with high CA 125 levels (>100 U/mL).

Allelic Imbalance in Regulation of ANRIL through Chromatin Interaction at 9p21 Endometriosis Risk Locus

Genome-wide association studies (GWASs) have discovered numerous single nucleotide polymorphisms (SNPs) associated with human complex disorders. However, functional characterization of the disease-associated SNPs remains a formidable challenge. Here we explored regulatory mechanism of a SNP on chromosome 9p21 associated with endometriosis by leveraging “allele-specific” functional genomic approaches. By re-sequencing 1.29 Mb of 9p21 region and scrutinizing DNase-seq data from the ENCODE project, we prioritized rs17761446 as a candidate functional variant that was in perfect linkage disequilibrium with the original GWAS SNP (rs10965235) and located on DNase I hypersensitive site. Chromosome conformation capture followed by high-throughput sequencing revealed that the protective G allele of rs17761446 exerted stronger chromatin interaction with ANRIL promoter. We demonstrated that the protective allele exhibited preferential binding affinities to TCF7L2 and EP300 by bioinformatics and chromatin immunoprecipitation (ChIP) analyses. ChIP assays for histone H3 lysine 27 acetylation and RNA polymerase II reinforced the enhancer activity of the SNP site. The allele specific expression analysis for eutopic endometrial tissues and endometrial carcinoma cell lines showed that rs17761446 was a cis-regulatory variant where G allele was associated with increased ANRIL expression. Our work illuminates the allelic imbalances in a series of transcriptional regulation from factor binding to gene expression mediated by chromatin interaction underlie the molecular mechanism of 9p21 endometriosis risk locus. Functional genomics on common disease will unlock functional aspect of genotype-phenotype correlations in the post-GWAS stage.

A large number of variants associated with human complex diseases have been discovered by genome-wide association studies (GWASs). These discoveries have been anticipated to be translated into the definitive understanding of disease pathogeneses; however, functional characterization of the disease-associated SNPs remains a formidable challenge. Here we explored regulatory mechanism of a variant on chromosome 9p21 associated with endometriosis, a common gynecological disorder. By scrutinizing linkage disequilibrium structure and DNase I hypersensitive sites across the risk locus, we prioritized rs17761446 as a candidate causal variant. The results of our “allele-specific” functional genomic approaches sheds light on regulatory mechanisms underlying 9p21 endometriosis risk locus, in which preferential bindings of TCF7L2 and its coactivator EP300 to the protective G allele of rs17761446 lead to stronger chromatin interaction with the promoter of ANRIL, which in turn activate transcription of the non-coding RNA. Motivated by the fact that TCF7L2 was a key transcription factor of Wnt signaling pathway, we postulated that the induction of Wnt signaling activated expression levels of ANRIL and cell cycle inhibitors, CDKN2A/2B. Functional genomics on common disease will unlock functional aspect of genotype-phenotype correlations in the post-GWAS stage.

P16-positive continuous minimal deviation adenocarcinoma and gastric type adenocarcinoma in a patient with Peutz-Jeghers syndrome

We report a case of Peutz-Jeghers syndrome (PJS) in a 33-year-old female patient with synchronous uterine cervical minimal deviation adenocarcinoma (MDA) and gastric type adenocarcinoma (GTA). The patient was diagnosed with PJS at the age of 10. At the time of consultation, she complained of watery discharge. Magnetic resonance imaging of the pelvis showed a poorly circumscribed mass in the uterine cervix. Histologically, both MDA and GTA components, as well as their transitional area, were observed. Both components were diffusely positive for MUC6, CK7 and, robustly, for p16. Moreover, the components were negative for ER, PgR and CEA, while HIK1083 and CK20 positive cells were found focally. Ki-67 labeling index in the MDA component was 5% while that in the GTA component was 50%. This case of GTA accompanied by MDA in a patient with PJS is distinct from the single previously-reported comparable case of which we are aware, with respect to the overexpression of p16 protein, an event considered rare in these tumors, and the continuity between the MDA and GTA components. This continuity favors the hypothesis that GTA arises from the dedifferentiation of MDA.

miR-200a, miR-200b and miR-429 are onco-miRs that target the PTEN gene in endometrioid endometrial carcinoma

Endometrioid endometrial carcinoma (EEC) is a common malignancy of the female genital tract. However, no adequate biomarker is currently available for predicting the prognosis of this cancer. Recent studies have revealed dysregulated expression of several microRNAs (miRNAs) in various cancer tissues, and therefore, these cancer-associated miRNAs (also called onco-miRs) could be promising prognostic biomarkers of cancer progression or metastasis. In this study, in order to identify onco-miRs and their possible targets involved in EEC, we performed microarray-based integrative analyses of miRNA and mRNA expression in specimens excised from EEC lesions and adjacent normal endometrial tissues. Using integrated statistical analyses, we identified miR-200a, miR-200b and miR-429 as highly up-regulated onco-miRs in EECs. Conversely, we detected expression of a tumor-suppressor gene, phosphatase and tensin homolog (PTEN), which was predicted in silico using a miRNA-targeting mRNA prediction algorithm, as a target of the three miRNAs and which was down-regulated in EECs. Furthermore, these miRNAs were validated to target PTEN experimentally using luciferase assays and real-time polymerase chain reaction. These results suggest that the occurrence of EEC is, at least in part, mediated by miRNA-induced suppression of PTEN expression.

Proteomic identification of autoantibodies in sera from patients with ovarian cancer as possible diagnostic biomarkers

BACKGROUND/AIM

Accumulating evidence shows that various types of cancers induce a specific immune response resulting in the production of antibodies against self-components (autoantibodies). The aim of the present study was to identify antigens for autoantibodies in sera from patients with ovarian cancer, especially clear cell carcinoma (CCC), as novel diagnostic markers for the disease.

MATERIALS AND METHODS

The reactivity of individual sera from patients was examined by two-dimensional (2-D) immunoblotting using lysates of CCC cell lines, ES-2 and RMG-1, as antigens to identify autoantigens. ELISA was established to quantitatively measure autoantibody titer of patients' sera.

RESULTS

Autoantibodies against RhoGDI were induced in sera of ovarian cancer patients. Elevated levels of autoantibodies against heterogeneous nuclear ribonucleoprotein L (hnRNPL) and a mitochondrial protein, dihydrolipoamide dehydrogenase (DLD), were detected in patients with CCC.

CONCLUSION

Autoantibodies against RhoGDI and hnRNPL and DLD may serve as novel diagnostic markers for ovarian cancer and CCC, respectively.

An automated rapid detection system using the quenching probe method for detecting interleukin 28B and inosine triphosphatase single nucleotide polymorphisms in chronic hepatitis C

Single nucleotide polymorphisms (SNPs) in the interleukin 28B gene (IL28B) are good pretreatment predictors of anti-hepatitis C virus (HCV) therapy with interferon. SNPs of the inosine triphosphatase (ITPA) gene are associated with reduced haemoglobin levels during treatment with ribavirin. The i-densy™ (Arkray, Inc.), which is based on the quenching probe (QP) method, automatically detects target genes in blood samples by fluorescence quenching within 100 min. Using a QP and primer set, a gene amplification response is generated that can quickly and easily detect a specific gene's arrangement by fluorometry. The present study was conducted to compare the utility of i-densy (QP method) with that of conventional direct sequencing (DS) for detecting SNPs in the IL28B and ITPA genes in chronic hepatitis C patients. Between June 2011 and January 2012, 73 consecutive patients underwent genotyping of IL28B, and 54 patients underwent genotyping of ITPA. All of the patients were seropositive for HCV-RNA. The IL28B and ITPA genotypes were tested for bi-allelic polymorphisms in rs8099917 (T/T, T/G and G/G; minor allele, G) and rs1127354 (C/C, C/A and A/A; minor allele, A), respectively. The results obtained with the QP method were identical to those obtained with the conventional DS method. The frequency of the IL28B genotypes TT, GT and GG were 74%, 24.7% and 1.4%, respectively, and those of the ITPA genotypes CC, AC and AA were 68.5%, 29.6% and 1.9%, respectively. These results indicate that the i-densy using the QP method can automatically, quickly and easily identify genotypes of IL28B and ITPA.

Novel hybrid laparoscopic sacrocolpopexy for pelvic organ prolapse with a severe paravaginal defect

Abdominal sacrocolpopexy is the gold standard for treating pelvic organ prolapse (POP) because of safety and durable good results. More recently laparoscopic sacrocolpopexy (LSC), a less invasive approach, has become popular. Although these surgeries are versatile and can treat almost all patients with POP, these techniques have shortcomings. Specifically, reinforcement of lateral vaginal defects are not very strong, thus patients with POP and a severe paravaginal defect are not good candidates for abdominal or laparoscopic sacrocolpopexy. To overcome this problem, we developed a novel type of LSC, which can reinforce severe paravaginal defects by using a reversed T-shaped anterior mesh combining the advantage of transvaginal mesh surgery. We refer to this novel surgery as 'hybrid LSC'. Thus far, eight patients have successfully undergone this surgery. Hybrid LSC is a simple and secure method, and is an alternative treatment for POP with a severe paravaginal defect.

Evaluation of laparoendoscopic single-site gynecologic surgery with a multitrocar access system

OBJECTS

Laparoendoscopic single-site surgery (LESS) is an ideal approach for gynecologic surgery and yields better cosmetic results. However, a standard umbilical approach with LESS is not appropriate for gynecologic surgery requiring intra-abdominal suturing and dissection requiring traction. Therefore, we have developed a new multitrocar access system for gynecologic LESS. The purpose of this study was to evaluate the efficacy of gynecologic LESS using this access system.

METHODS

This access system consists of one 12-mm trocar, two 5-mm trocars, and a 5-mm flexible laparoscope. Two 5-mm trocars with small port heads were inserted cross-wise on opposite sides of the sleeve of the centrally positioned 12-mm trocar to maintain triangulation. Thirty-eight patients with various gynecologic conditions underwent LESS with this access system. The results of these surgeries were retrospectively compared to those of conventional laparoscopic procedures.

RESULTS

Of the 38 LESS procedures performed with this access system, none was up-converted, converted to an open laparotomy, or required blood transfusion. The Salpingo-oophorectomy with LESS had several benefits, such as no extension of the skin incision of the trocar site and no leakage of the contents of the ovarian cyst into the peritoneal cavity, over that with conventional laparoscopy. A comparison of LESS (11 patients) and conventional laparoscopy (16 patients) for total hysterectomy showed no significant difference in total blood loss (234.0 mL vs. 221.6 mL) or the weight of the resected uterus (276.0 g vs. 285.0 g), although the mean total operative time was greater with LESS (199.0 min vs. 168.5 min).

CONCLUSION

Our multitrocar access system is safe and secure, and can be adapted for various gynecologic surgeries involving complicated procedures. LESS with this access system achieves results comparable to those of conventional laparoscopy with 4 ports, although the operative time is longer.

Novel hybrid mesh surgery combines sacrocolpopexy with transvaginal mesh placement for pelvic organ prolapse

Mesh surgeries, such as sacrocolpopexy and transvaginal mesh surgery, are commonly used to treat pelvic organ prolapse. Although mesh surgeries have a high success rate, they are unsuitable for some patients. For a patient with pelvic organ prolapse and highly calcified multiple fibroids, we performed hybrid sacrocolpopexy combined with transvaginal mesh surgery with a method modified for the patient's condition. Three months after surgery, the results were highly satisfactory. This approach is simple, secure, and versatile for patients who are not good candidates for conventional mesh surgeries. This novel hybrid mesh surgery is an option for treating various types of pelvic organ prolapse.

Gasless laparoscopically assisted myomectomy using a wound retraction system

INTRODUCTION

The purpose of this study was to elucidate the feasibility of gasless laparoscopically assisted myomectomy (LAM) using a wound retraction system. This method treats symptomatic uterine myomas by combining laparoscopy with a mini-laparotomy to enucleate myoma nodules and to close the uterine myometrium.

METHODS

This study includes 275 patients who underwent gasless LAM. For patients with fewer than three myoma nodules, the location of the largest nodule was classified as anterior, fundal, or posterior. The operative outcomes, intraoperative and postoperative courses, and complications were examined.

RESULTS

All operations were performed satisfactorily, and no conversions to laparotomy were required. None of the patients developed serious complications. The mean blood loss and operating time were 190.3 mL and 152.2 minutes, respectively. The mean myoma size was 8.9 cm, and the mean number of myomas per patient was 2.8. The average postoperative hospital stay was 5.7 days. There were no significant differences in resected myoma size, blood loss, and surgical duration with respect to the location of the largest nodule.

CONCLUSION

Gasless LAM with a wound retractor is feasible and allows surgeons to perform myomectomy safely and cost-effectively, without requiring advanced laparoscopic surgical skills and while maintaining minimum invasiveness.

A case of tumor lysis syndrome following chemotherapy for a uterine epithelioid leiomyosarcoma with focal rhabdomyosarcomatous differentiation

Tumor lysis syndrome (TLS) is a potential complication characterized by hyperuricemia, hyperphosphatemia, hyperkalemia and hypocalcemia due to massive necrosis of malignant cells after cytotoxic therapy. This fatal complication occurs frequently in tumors with hematological malignancies, such as acute lymphoblastic leukemia and Burkitt's lymphoma, and in other tumors with high proliferative rates and tumor burdens. TLS is rarely associated with the treatment of solid tumors. Herein, we report a case of TLS following the initial administration of effective chemotherapy for an epithelioid leiomyosarcoma with focal rhabdomyosarcomatous differentiation of the uterus.

Amyloidogenic and non-amyloidogenic transthyretin Asn 90 variants

Recently, a new transthyretin (TTR) variant was described in the normal Portuguese and German populations. The same substitution was found associated with familial amyloidotic polyneuropathy (FAP) in an American family of Italian origin. Comparative isoelectric focusing studies showed a difference in the mobility pattern between the non-pathogenic and pathogenic variants. However, comparative DNA sequencing between them did not reveal any additional mutation. Comparative isoelectric focusing between the variants and TTR Asn 90 produced by recombinant techniques indicated that the non-pathogenic variant has the electrophoretic behaviour expected for the mutation. We suggest that an as yet unknown post-translational modification may have occurred in the FAP-associated Asn 90 variant, turning it into an amyloidogenic molecule.

Serial histologic observation of endometrial adenocarcinoma treated with high-dose progestin until complete disappearance of carcinomatous foci--review of more than 25 biopsies from five patients

This study aimed to document chronologic histologic changes of endometrial biopsies from patients with endometrial adenocarcinoma on high-dose progestin therapy. Seven patients with presumptive FIGO stage IA endometrial adenocarcinoma treated with medroxyprogesterone acetate 600 mg/day were investigated retrospectively. Good response was defined as complete disappearance of carcinoma foci within 16 weeks of treatment and poor response as the presence of residual foci at 16 weeks. Two patients were poor responders and were excluded from the study, while five good responders were analyzed. Hematoxylin and eosin (H&E)-stained slides were reviewed and analyzed based on nine histologic features to describe the histology observed commonly in good responders. All the five good responders showed relatively uniform morphologic changes during the high-dose progestin therapy and the common histology was described as follows. The first change was swelling of the neoplastic glandular epithelial cells with pale vacuolated cytoplasm and round to oval nuclei. Mitotic arrest was also observed. Next, the epithelia were disrupted by lymphoplasmocytic infiltration and replaced by low cuboidal epithelium with or without squamous or morular metaplasia. The stromal area increased with predecidual changes. The final morphology was small atrophic glands scattered in predecidual stroma with dilated vessels. Therefore, the morphologic change of the endometrial biopsy observed in earlier stage of treatment might be able to predict good response to high-dose progestin therapy.

Separation of polyvinyl chloride (PVC) from automobile shredder residue (ASR) by froth flotation with ozonation

The purpose of this study is to develop froth flotation to separate polyvinyl chloride (PVC) from automobile shredder residue (ASR) plastic mixtures of variable composition. Some polymers in ASR polymer mixtures have similar density and hydrophobicity with PVC and thus selective flotation of PVC from ASR polymer mixtures cannot be achieved. The present study focused on the surface modification of PVC with ozonation, and then the modified PVC can be separated from other polymers by the following froth flotation. The results of this study indicate that the selective recovery of PVC from real ASR polyethylene tetra pethelate (PET), polymethyl methacrylate (PMMA), polybutyl methacralate (PBMA), ethyl acrylate (EA), polycarbonate (PC) and rubber mixtures can be accomplished in a three-step process involving a gravity separation, ozonation and froth flotation. The rubber was removed from other heavy ASR (PVC, PET, PMMA, PBMA, EA and PC) polymers by froth flotation without mixing. It was found that ozonation process produced the desired difference in contact angle required (from 89.5 to 73.0 degrees ) for separation of PVC from other heavy ASR polymers, whereas the contact angles of other polymers was slightly decreased. The most of the load ASR, i.e. about 72.4% is floated away and 27.6% was settled down. The highest component 96.7% of PVC was recovered in the settled fraction. As a result of this research effort, the surface modification of PVC with ozonation can be efficiently useful to separate the PVC from other similar density ASR mixed polymers.

Endometrial aspiration cytology for diagnosis of peritoneal lesions in extrauterine malignancies

OBJECTIVE

To evaluate the usefulness of endometrial aspiration cytology for assessing malignant cells of extrauterine origin.

STUDY DESIGN

Endometrial cytology was performed on 224 patients with primary ovarian cancer, 10 with fallopian tube cancer and 45 with peritoneal tumors.

RESULTS

Of 224 patients with ovarian cancer, 53 (23.7%) had positive endometrial cytology. Positive rates were: stage I, 4.3%; stage II, 25.0%; stage III, 39.7%; stage IV, 34.5%. Histologic positive rates were: serous, 28.7%; mucinous, 11.4%; clear cell, 23.1%; endometrioid and unclassifiable adenocarcinomas, 28.0%. Of 5 patients with ovarian cancer, 2 were asymptomatic, but aspiration cytology was positive. Of 10 patients with fallopian tube cancer, 9 (90.0%) had positive endometrial cytology. The positive rate on endometrial cytology was 56.7% in stomach cancer, 60.0% in breast cancer and 20.0% in colon cancer. Of 1,209 women with stomach cancer, 30 (2.4%) displayed ovarian metastasis. Of these, 7 (23.3%) had Krukenberg's tumor; endometrial cytology was positive in 1 (14.3%). In 7 of 17 patients with positive endometrial cytology, clinical diagnosis was made before stomach cancer therapy.

CONCLUSION

Endometrial aspiration cytology is useful for identifying nongynecologic malignant cells, diagnosing ovarian and fallopian tube cancers, and determining peritoneal dissemination and metastasis originating from gastrointestinal and breast cancers.

Heavy metals removal from automobile shredder residues (ASR)

The fate of heavy metals during a separation process for automobile shredder residues (ASR) was investigated. A washing method to remove heavy metals from the ASR was also investigated. Although the separation process was not designed for removal of heavy metals, but for the recovery of reusable materials, the heavy metal content in the ASR was efficiently decreased. The concentrations of Pb, Cr and Cd in ASR were effectively reduced by a nonferrous metals removal process, and the As concentration was reduced by the removal of light dusts during the separation process. Five heavy metals (As, Se, Pb, Cr, Cd) remaining in the ASR after the separation process satisfied the content criteria of the Environmental Quality Standards for Soil (EQSS), while the concentrations of As, Se, Pb in the leachate from the remaining ASR did not satisfy the elution criteria of the EQSS. After additional washing of the remaining ASR with a pH 1 acid buffer solution, the As, Se, and Pb concentrations satisfied the EQSS for elution. These results indicate that an ASR residue can be safely recycled after a separation process, followed by washing at acidic pH.

Genetic variations and haplotype structures of the ABCB1 gene in a Japanese population: an expanded haplotype block covering the distal promoter region, and associated ethnic differences

As functional ABCB1 haplotypes were recently reported in the promoter region of the gene, we resequenced the ABCB1 distal promoter region, along with other regions (the enhancer and proximal promoter regions, and all 28 exons), in a total of 533 Japanese subjects. Linkage disequilibrium (LD) analysis based on 92 genetic variations revealed 4 LD blocks with the same make up as previously described (Blocks -1, 1, 2 and 3), except that Block 1 was expanded to include the distal promoter region, and that a new linkage between polymorphisms -1,789G>A in the distal promoter region and IVS5 + 123A>G in intron 5 was identified. We re-assigned Block 1 haplotypes, and added novel haplotypes to the other 3 blocks. The reported promoter haplotypes were further classified into several types according to tagging variations within Block 1 coding or intronic regions. Our current data reconfirm the haplotype profiles of the other three blocks, add more detailed information on functionally-important haplotypes in Block 1 and 2 in the Japanese population, and identified differences in haplotype profiles between ethnic groups. Our updated analysis of ABCB1 haplotype blocks will assist pharmacogenetic and disease-association studies carried out using Asian subjects.

Haplotype structures of the UGT1A gene complex in a Japanese population

Genetic polymorphisms of UDP-glucuronosyltransferases (UGTs) are involved in individual and ethnic differences in drug metabolism. To reveal co-occurrence of the UGT1A polymorphisms, we first analyzed haplotype structures of the entire UGT1A gene complex using the polymorphisms from 196 Japanese subjects. Based on strong linkage disequilibrium between UGT1A8 and 1A10, among 1A9, 1A7, and 1A6, and between 1A3 and 1A1, the complex was divided into five blocks, Block 8/10, Block 9/6, Block 4, Block 3/1, and Block C, and the haplotypes for each block were subsequently determined/inferred. Second, using pyrosequencing or direct sequencing, additional 105 subjects were genotyped for 41 functionally tagged polymorphisms. The data from 301 subjects confirmed the robustness of block partitioning, but several linkages among the haplotypes with functional changes were found across the blocks. Thus, important haplotypes and their linkages were identified among the UGT1A gene blocks (and segments), which should be considered in pharmacogenetic studies.

Gasless Laparoscopic Surgery Using a New Intra-abdominal Fan Retractor System: An Experience of 500 Cases

AIM

The aim of this study is to report the feasibility of a newly developed intra-abdominal fan retractor system for use in gynecologic laparoscopic surgery.

METHODS

Five hundred women undergoing gasless laparoscopic surgery using the abdominal wall lifting device were included in the study. The intraoperative and postoperative courses, and complications were examined.

RESULTS

The intra-abdominal retractor system provided adequate exposure in all cases, except for one patient with morbid obesity. Neither the presence of the intra-abdominal retractor blades nor the mechanical arm interfered with the placement of instruments during surgery. No complications related to the use of gasless laparoscopy were encountered in this study period.

CONCLUSION

The new intra-abdominal fan retractor system is feasible in gynecologic laparoscopic surgery.

Frequent somatic mutations in PTEN and TP53 are mutually exclusive in the stroma of breast carcinomas

We have recently shown that loss of heterozygosity of specific markers, including those at 10q23, 17p13-p15 and 16q24, can occur in the stromal and epithelial compartments of primary invasive breast carcinomas. Here, we demonstrate high frequencies of somatic mutations in TP53 (encoding tumor protein p53) and PTEN (encoding phosphate and tensin homolog) in breast neoplastic epithelium and stroma. Mutations in TP53 and PTEN are mutually exclusive in either compartment. In contrast, mutations in WFDC1 (16q24, encoding WAP four-disulfide core domain 1) occur with low frequency in the stroma.

Gene fusion involving HMGIC is a frequent aberration in uterine leiomyomas

HMGIC, a high-mobility-group protein gene encoding an architectural transcription factor, was recently identified as the target of gene fusion in a variety of human benign mesenchymal tumors; some of these events were chromosomal translocations involving 12q13-15. HMGIC consists of three DNA-binding domains (encoded by exons 1-3), a spacer, and an acidic carboxyl-terminal regulatory domain (exons 4-5). To determine the spectrum and nature of the aberrations in uterine myomas in Japanese patients, we systematically examined the tumors of 45 patients for all possible types of gene fusions involving HMGIC, by means of 3'-rapid amplification of cDNA ends (RACE) and reverse transcriptase-polymerase chain reaction (RT-PCR) experiments. HMGIC gene fusions were found in 16 (36%) of the tumors; aberrant splicings to five cryptic sequences located in introns of the HMGIC gene were found in 11 of these cases, and translocations causing juxtaposition to other genes, such as COX6C and RA D51B, were found in 5. In all fusion transcripts, the first two or three exons of HMGIC were fused to ectopic sequences. Our results suggest that a fusion event, resulting in the separation of the DNA-binding domains of HMGIC from the spacer and the acidic carboxyl-terminal regulatory domain, is a common tumorigenic mechanism in the development of uterine myomas.

Comparison of the essential oils of Glehnia littoralis from Northern and Southern Japan

The essential oils from aerial and root parts of Glehnia littoralis were investigated by GC and GC-MS, and 125 compounds were identified. Plants were obtained from Northern and Southern Japan, and samples from the same locations were cultivated either exposed or unexposed to sunlight. The main constituents of the essential oils were found to be alpha-pinene (0.03-13.40%), limonene (0.15-10.71%), beta-phellandrene (0.03-22.93%), germacrene B (0.27-8.33%), spathulenol (0.24-6.50%), beta-oplopenone (0.06-6.47%), panaxynol (0.38-24.58%), propyl octanoate (3.44-27.85%), hexadecanoic acid (0.45-27.80%), and linoleic acid (0.16-17.56%). Terpenoid compounds were found in higher concentrations in the Northern type oils than in the Southern types, whereas the concentration of polyacetylenic compounds was higher in one of the Southern samples, except from the aerial parts of those cultivated exposed. Consequently, the constitution of the essential oils from G. littoralis could be separated into Northern and Southern types.

Germline mutations in BMPR1A/ALK3 cause a subset of cases of juvenile polyposis syndrome and of Cowden and Bannayan-Riley-Ruvalcaba syndromes

Juvenile polyposis syndrome (JPS) is an inherited hamartomatous-polyposis syndrome with a risk for colon cancer. JPS is a clinical diagnosis by exclusion, and, before susceptibility genes were identified, JPS could easily be confused with other inherited hamartoma syndromes, such as Bannayan-Riley-Ruvalcaba syndrome (BRRS) and Cowden syndrome (CS). Germline mutations of MADH4 (SMAD4) have been described in a variable number of probands with JPS. A series of familial and isolated European probands without MADH4 mutations were analyzed for germline mutations in BMPR1A, a member of the transforming growth-factor beta-receptor superfamily, upstream from the SMAD pathway. Overall, 10 (38%) probands were found to have germline BMPR1A mutations, 8 of which resulted in truncated receptors and 2 of which resulted in missense alterations (C124R and C376Y). Almost all available component tumors from mutation-positive cases showed loss of heterozygosity (LOH) in the BMPR1A region, whereas those from mutation-negative cases did not. One proband with CS/CS-like phenotype was also found to have a germline BMPR1A missense mutation (A338D). Thus, germline BMPR1A mutations cause a significant proportion of cases of JPS and might define a small subset of cases of CS/BRRS with specific colonic phenotype.

Genetic model of multi-step breast carcinogenesis involving the epithelium and stroma: clues to tumour-microenvironment interactions

Although numerous studies have reported that high frequencies of loss of heterozygosity (LOH) at various chromosomal arms have been identified in breast cancer, differential LOH in the neoplastic epithelial and surrounding stromal compartments has not been well examined. Using laser capture microdissection, which enables separation of neoplastic epithelium from surrounding stroma, we microdissected each compartment of 41 sporadic invasive adenocarcinomas of the breast. Frequent LOH was identified in both neoplastic epithelial and/or stromal compartments, ranging from 25 to 69% in the neoplastic epithelial cells, and from 17 to 61% in the surrounding stromal cells, respectively. The great majority of markers showed a higher frequency of LOH in the neoplastic epithelial compartment than in the stroma, suggesting that LOH in neoplastic epithelial cells might precede LOH in surrounding stromal cells. Furthermore, we sought to examine pair-wise associations of particular genetic alterations in either epithelial or stromal compartments. Seventeen pairs of markers showed statistically significant associations. We also propose a genetic model of multi-step carcinogenesis for the breast involving the epithelial and stromal compartments and note that genetic alterations occur in the epithelial compartments as the earlier steps followed by LOH in the stromal compartments. Our study strongly suggests that interactions between breast epithelial and stromal compartments might play a critical role in breast carcinogenesis and several genetic alterations in both epithelial and stromal compartments are required for breast tumour growth and progression.

Opposite association of two PPARG variants with cancer: overrepresentation of H449H in endometrial carcinoma cases and underrepresentation of P12A in renal cell carcinoma cases

Peroxisome proliferator activated receptor gamma (PPARgamma) is a nuclear hormone receptor that has been shown to regulate differentiation and cell growth. Studies of the differentiative effects of PPARgamma agonists on several cancer cell lines led to the hypothesis that dysfunction of PPARgamma contributes to tumorigenesis. These functional observations were strengthened by genetic evidence: somatic loss-of-function mutations in PPARG, encoding PPARgamma, in sporadic colorectal carcinomas and somatic translocation of PAX8 and PPARG in follicular thyroid carcinoma. Recently overrepresentation of the H449H variant was found in a cohort of American patients with glioblastoma multiforme. The glioblastoma multiforme data suggest that PPARG contributes common, low-penetrance alleles for cancer susceptibility. To test this hypothesis in a broader range of cancers we examined a series of carcinomas of the cervix, endometrium, ovary, prostate, and kidney for germline sequence variation in PPARG. In addition to the two common sequence variants, P12A and H449H, there were five other sequence variants. P12A alleles were underrepresented in renal cell carcinoma patients compared to country-of-origin race-matched controls (3.75% vs. 12.1%, P<0.04). In contrast, the H449H variant was overrepresented in individuals with endometrial carcinoma compared to controls (14.4% vs. 6.25%, P<0.02). These observations lend genetic evidence consistent with our hypothesis that PPARG serves as a common, low-penetrance susceptibility gene for cancers of several types, especially those epidemiologically associated with obesity and fat intake.

Is arterial surgery advisable for patients over 80 years of age?

BACKGROUND

Recently life expectancy has become longer and longer. The purpose of this study was to analyse whether arterial surgery for patients over 80 years of age is advisable.

METHODS

During the last 14 years, 527 patients, 50 of whom were over 80 and 477 of whom were under 80 years of age, received graft replacement or bypass surgery. They suffered from ruptured abdominal aortic aneurysm (R-AAA, n=21), non-ruptured abdominal aortic aneurysm (N-R AAA, n=133) or arteriosclerosis obliterans (ASO, n=373). Complications such as cerebrovascular disease, ischemic heart disease, respiratory and kidney dysfunction, and risk factors for ASO were also checked.

RESULTS

All of the patients over 80 with R-AAA (n=3/3) and 50% of the patients under 80 with R-AAA (n=9/18) died during their stay in the hospital. However, none of the N-R AAA patients over 80 (n=0/7) and only one of the 126 N-R AAA patients (0.8%) under 80 died. For the patients over 80 with ASO, the graft patency rate was better than the patients survival rate. There were no age-specific factors that should condemn arterial surgery for patients over 80 years of age.

CONCLUSIONS

Arterial surgery should not be ruled out on the basis of age alone.

Frequent loss of PTEN expression is linked to elevated phosphorylated Akt levels, but not associated with p27 and cyclin D1 expression, in primary epithelial ovarian carcinomas

PTEN (MMAC1/TEP1), a tumor suppressor gene on chromosome subband 10q23.3, is variably mutated and/or deleted in a variety of human cancers. Germline mutations in PTEN, which encode a dual-specificity phosphatase, have been implicated in at least two hamartoma tumor syndromes that exhibit some clinical overlap, Cowden syndrome and Bannayan-Riley-Ruvalcaba syndrome. Among several series of ovarian cancers, the frequency of loss of heterozygosity (LOH) of markers flanking and within PTEN, is approximately 30 to 50%, and the somatic intragenic PTEN mutation frequency is <10%. In this study, we screened primary adenocarcinomas of the ovary for LOH of polymorphic markers within and flanking the PTEN gene and for intragenic mutations of the PTEN gene and compared them to PTEN expression using immunohistochemistry. Furthermore, we sought to detect the expression of the presumed downstream targets of PTEN, such as P-Akt, p27, and cyclin D1 by immunohistochemistry. LOH at 10q23 was observed in 29 of 64 (45%) cases. Of the 117 samples, 6 somatic intragenic PTEN mutations, 1 germline mutation, and 1 novel polymorphism were found in 7 (6%) patients. Immunostaining of 49 ovarian cancer samples revealed that 13 (27%) were PTEN immunostain-negative, 25 (51%) had reduced staining, and the rest (22%) were PTEN expression-positive. Among the 44 informative tumors assessed for 10q23 LOH and PTEN immunostaining, there was an association between 10q23 LOH and decreased or absent staining (P = 0.0317). Of note, there were five (11%) tumors with neither mutation nor deletion that exhibited no PTEN expression and 10 (25%) others without mutation or deletion but had decreased PTEN expression. Among the 49 tumors available for immunohistochemistry, 28 (57%) showed P-Akt-positive staining, 24 (49%) had decreased p27 staining, and cyclin D1 was overexpressed in 35 (79%) cases. In general, P-Akt expression was inversely correlated with PTEN expression (P = 0.0083). These data suggest that disruption of PTEN by several mechanisms, allelic loss, intragenic mutation, or epigenetic silencing, all contribute to epithelial ovarian carcinogenesis, and that epigenetic silencing is a significant mechanism. The Akt pathway is prominently involved, but clearly not in all cases. Surprisingly, despite in vitro demonstration that p27 and cyclin D1 lies downstream of PTEN and Akt, there was no correlation between p27 and cyclin D1 expression and PTEN or P-Akt status. Thus, in vivo, although PTEN and Akt play a prominent role in ovarian carcinogenesis, p27 and cyclin D1 might not be the primary downstream targets. Alternatively, these observations could also suggest that pathways involving other than Akt, p27 and cyclin D1 that lie downstream of PTEN play roles in ovarian carcinogenesis.

Fusion of a sequence from HEI10 (14q11) to the HMGIC gene at 12q15 in a uterine leiomyoma

Uterine leiomyoma, a benign smooth-muscle tumor of the myometrium, is the most commonly encountered neoplasm in women of reproductive age. Band q15 of chromosome 12 is often rearranged in benign mesenchymal tumors such as uterine leiomyomas, and the HMGIC gene, encoding a protein of the high-mobility-group (HMG), is present in that region. Using 3' rapid amplification of cDNA ends (3'RACE) experiments, we isolated an ectopic sequence that was fused to HMGIC in a uterine leiomyoma. Cloning of the fusion cDNA identified a gene termed rising dbl quote, left (low)homo sapiens enhancer of invasion 10" (HEI10) as the fusion partner. Radiation hybrid mapping revealed that the normal location of HEI10 is at 14q11. In the fusion transcript the first two exons of the HMGIC gene, which encode DNA-binding domains, were fused to the 3' portion of the HEI10 gene. This rearrangement implicates HMGIC in the tumorigenesis of uterine leiomyoma, and suggests that its fusion HMGIC product may play a role in mesenchymal differentiation.

Three aberrant splicing variants of the HMGIC gene transcribed in uterine leiomyomas

Cytogenetic aberrations involving chromosome region 12q13-15 occur frequently among benign mesenchymal tumors in humans, e.g., pleomorphic adenomas of the parotid gland, pulmonary chondroid hamartomas, lipomas, or uterine leiomyomas. HMGIC, a gene encoding a protein of the high-mobility group, has been identified as a target of those events. Using the 3' rapid amplification of cDNA ends (RACE) technique, we identified six different fusion transcripts of the HMGIC gene among 13 uterine leiomyomas; three of these variants had not been described before. Radiation-hybrid mapping located all three of the novel fusion transcripts in the same chromosomal region as the HMGIC gene. Cloning of the entire HMGIC gene in a genomic contig of P1-derived artificial chromosomes and cosmids revealed that the 3' portion of each novel fusion transcript contained cryptic exonic sequences (designated a, b, and c) present in intron 3 of the HMGIC gene. Thus, aberrant alternative splicing was responsible for abnormal HMGIC isoforms in those myomas. Identification of these novel variants suggested that aberrant splicing can join chromosomal translocation and inversion as a mechanism for producing abnormal HMGIC transcripts, and that separation of the DNA binding domains of HMGIC from its acidic carboxyl-terminal regulatory domain can lead to development of benign mesenchymal tumors.

Cultured keratinocytes from plectin/HD1-deficient epidermolysis bullosa simplex showed altered ability of adhesion to the matrix

Epidermolysis bullosa simplex associated with late onset of muscular dystrophy has been found to show defective expression of plectin, an intracytoplasmic protein in hemidesmosomes. In this report, we examined ability of cell-to-matrix attachment of cultured keratinocytes derived from a case with this disease by various cell biological methods, and compared it to that of normal keratinocytes. In cell adhesion assay, the patient keratinocytes showed more prominent short-time cell adhesion than normal keratinocytes. In contrast, the patient keratinocytes could be detached much easier than normal keratinocytes in cell detachment assay by treatment with dispase. In phagokinetic track assay, no apparent difference of cell migration was observed between the patient and normal keratinocytes. These results indicate that plectin-deficiency may up-regulate short-term cell contact and reduce stable cell-matrix adhesion at the epidermal basement membrane zone.

[A case of left occipital lobe hemorrhage in a patient with progressive systemic sclerosis: evaluation of cerebral angiography and histology]

Involvement of the central nervous system is uncommon in progressive systemic sclerosis, with only 2 reported cases associated with intracerebral hemorrhage detected by neuroimaging. A 55-year-old woman with a 10-year history of scleroderma presented with left occipital lobe hemorrhage manifesting as headache and vomiting. She had no signs of hypertension, diabetes mellitus and hyperlipidemia. CT and MRI, on admission, showed left occipital lobe hemorrhage with ventricular rupture and acute left subdural hematoma. Serial cerebral angiography was performed on day 0, day 7 and day 14, and found no evidence of aneurysm, arteriovenous multiformation or tumor stain in the left occipital lobe. However, the bilateral anterior cerebral arteries showed increasing segmental narrowing suggestive of vasculitis. Histological examination of a section from the brain cortex adjacent to the hemorrhage revealed no evidence of vasculitis, fibrinoid degeneration or amyloid deposition. Focal vasculitis may have occurred secondary to the homorrhagic lesion.

Biallelic inactivating mutations and an occult germline mutation of PTEN in primary cervical carcinomas

A tumor suppressor gene on chromosome sub-band 10q23.3, PTEN, is frequently mutated or deleted in a variety of human cancers. Germline mutations in PTEN, that encodes a dual-specificity phosphatase, have been implicated in two hamartoma-tumor syndromes that exhibit some clinical overlap, Cowden syndrome and Bannayan-Zonana syndrome. Although cervical cancer is not a known component of these two syndromes, loss of heterozygosity (LOH) of markers on chromosome arm 10q is frequently observed in cervical cancers. To determine the potential role that PTEN mutation may play in cervical tumorigenesis, we screened 20 primary cervical cancers for LOH of polymorphic markers within and flanking the PTEN gene, and for intragenic mutations in the entire coding region and exon-intron boundaries of the PTEN gene. LOH was observed in 7 of 19 (36.8%) cases. Further, one sample may have homozygous deletion. Three (15%) intragenic mutations were found: two were somatic missense mutations in exon 5, that encodes the phosphatase motif, and an occult germline intronic sequence variant in intron 7, that we show to be associated with aberrant splicing. All three samples with the mutations also had LOH of the wild-type allele. These data indicate that disruption of PTEN by allelic loss or mutation may contribute to tumorigenesis in cervical cancers. In cervical cancer, unlike some other human primary carcinomas, e.g., those of the breast and thyroid, biallelic structural PTEN defects seem necessary for carcinogenesis. Further, one in 20 unselected cervical carcinomas was found to have a germline PTEN mutation; it is unclear whether the patient with this mutation had Cowden disease or a related syndrome.

Molecular cloning and characterization of three novel cytochrome P450 2D isoforms, CYP2D20, CYP2D27, and CYP2D28 in the Syrian hamster (Mesocricetus auratus)

We cloned three novel cytochrome P450 (CYP) 2D cDNAs in the Syrian hamster (Mesocricetus auratus). Each clone contained an open reading frame of 1500 nucleotides encoding a protein of 500 amino acids. The deduced amino acid sequences of these had high identities with those of the other CYP2D members, therefore, the clones were assigned as CYP2D20, CYP2D27, and CYP2D28. Northern blot analysis showed that the CYP2D27 mRNA was expressed in liver, but not in kidney, small intestine, and brain, while the CYP2D20 and CYP2D28 mRNAs were not detected in these tissues examined. The expression of CYP2D27 mRNA in liver did not show sex difference and was not induced by either 3-methylcholanthrene or phenobarbital treatment. We characterized the enzyme activities of recombinant CYP2D27 expressed in COS-7 cells. The CYP2D27 protein had the bufuralol 1'-hydroxylase and debrisoquine 4-hydroxylase activities that are specific to the CYP2D subfamily.

Novel gene fusion of COX6C at 8q22-23 to HMGIC at 12q15 in a uterine leiomyoma

Cytogenetic analyses have shown that aberrations involving 12q13-15 are frequent chromosomal changes in a variety of human benign mesenchymal tumors, e.g., pleomorphic adenomas of the parotid gland, pulmonary chondroid hamartomas, lipomas, and uterine leiomyomas. Recently, the high-mobility group protein gene HMGIC was identified as the target gene affected by the 12q13-15 aberrations. Using 3' rapid amplification of cDNA ends experiments, we isolated novel ectopic sequences fused to HMGIC in a uterine leiomyoma. Cloning of the fusion cDNA identified the human cytochrome c oxidase subunit VIc (COX6C) gene on 8q22-23 as the fusion partner of HMGIC. Nucleotide sequences of the fusion transcript revealed that the first 3 exons of the HMGIC gene, encoding the 3 DNA binding domains, was fused to the exon 2 of the COX6C gene. The identification of a gene rearrangement suggests a role for HMGIC in tumorigenesis of uterine leiomyoma and suggests a possible involvement of HMGIC in mesenchymal differentiation. Genes Chromosomes Cancer 27:303-307, 2000.

Cloning and expression analysis of a new member of the cytochrome P450, CYP2A15 from the Chinese hamster, encoding testosterone 7alpha-hydroxylase

We cloned a new cytochrome P450 cDNA encoding testosterone 7alpha-hydroxylase in the Chinese hamster, designated CYP2A15 which shares significant amino acid sequence homology with members of the CYP2A subfamily. The CYP2A15 cDNA was isolated by screening a liver cDNA library and the sequence contains an open reading frame of 1482 nucleotides encoding a polypeptide of 493 amino acids with a calculated molecular mass of 56,295 Da. This is flanked by a 5'-untranslated region of 2 bp and a 3' untranslated region of 191 bp including the poly(A) tail. We determined the catalytic activity of CYP2A15 using microsomes obtained by transient expression of its cDNA in transfected COS-7 cells. The heterologously expressed CYP2A15 was found to hydroxylate testosterone at position 7alpha in a reconstituted system. RT-PCR experiments revealed that the mRNA of CYP2A15 was expressed in liver, but not detected in kidney, lung, or small intestine. The expression of CYP2A15 mRNA was slightly induced by treatment with either rifampicin or 3-methylcholanthrene.

Molecular cloning, heterologous expression, and characterization of a novel member of CYP2A in the Syrian hamster

The cDNA clone coding for a novel cytochrome P-450 2A subfamily member (CYP2A16) was isolated from a Syrian hamster liver cDNA library. The deduced amino acid sequence of CYP2A16 showed more than 90% identity with those of rat CYP2A3 and mouse CYP2A4/5. The catalytic activity of CYP2A16 was determined by transient expression of its cDNA in transfected COS7 cells and CYP2A16 was found to have the testosterone 2 beta-, 15 alpha-, and 15 beta-hydroxylases, coumarin 7-hydroxylase, and ethoxycoumarin O-deethylase activities. These enzymatic characteristics of CYP2A16 are different from those of other Syrian hamster CYP2A subfamily members, CYP2A8 and CYP2A9. Northern blot analysis showed that CYP2A16 was expressed in kidney and lung while most of the other CYP2A subfamily members have been reported to be expressed in liver and olfactory. These observations indicated that the Syrian hamster CYP2A16 had unique properties compared with those of other CYP2A subfamily members.

Two target regions of allelic loss on chromosome 9 in urinary-bladder cancer

Allelic losses on chromosome 9 are common in a wide variety of human tumors; moreover, two predisposing loci for some inherited cancer syndromes, i.e., familial malignant melanoma and Gorlin syndrome, have been identified on this chromosome. To define the location of putative tumor suppressor genes involved in cancer of the urinary bladder, 85 bladder cancers were examined for allelic loss at 18 microsatellite loci on chromosome 9. Correlations were also sought between loss of heterozygosity on chromosome 9 and several clinicopathological parameters. Allelic loss was observed in 54 of the tumors (64%) and deletion mapping identified two target regions; one at an interval on 9p21 flanked by D9S736 and D9S165, and the other at an interval on 9q31-34 flanked by D9S58 and D9S61. No subtle mutation was detected in the PTCH gene which lies in the latter interval. Allelic loss on chromosome 9 was observed frequently in low grade and non-invasive tumors as well as in tumors of more advanced phenotype. Inactivation of tumor suppressor genes lying in either of two regions of common deletion identified on chromosome 9 might affect carcinogenic mechanisms at an early stage of tumor development in the urinary bladder.

A novel positive regulatory element that enhances hamster CYP2A8 gene expression mediated by xenobiotic responsive element

CYP2A8 is a major form of cytochrome P-450 inducible by 3-methylcholanthrene in Syrian hamster liver. To identify DNA elements necessary for the transcriptional activation of the CYP2A8 gene, we analyzed the regulatory region of the CYP2A8 gene and conducted transient transfection experiments of CYP2A8-luciferase fusion plasmids in primary cultures of hamster hepatocytes. We analyzed up to -5 kb of the 5'-flanking region and found the region sufficient for the 3-methylcholanthrene-inducible gene expression. This region contained a consensus sequence for xenobiotic responsive element (XRE) between -2366 and -2349, which was shown to be essential for induction of the gene expression. Furthermore, we found a novel positive regulatory element for XRE-mediated gene expression (PREX) located upstream of the XRE. This element is not identified in any genes inducible by 3-methylcholanthrene so far reported. Without PREX, the XRE-mediated promoter activity was enhanced nearly 10-fold, whereas with PREX, the activity was enhanced 20-fold over the basal level. Gel mobility shift assays revealed specific binding of nuclear proteins to PREX. Mutations and deletions of PREX caused a loss of the binding and promoter-enhancing activities, respectively. Moreover, transient expression experiments showed that the enhancing activity of PREX was not observed in Drosophila Schneider's line 2 cells, which were shown to lack the PREX binding proteins.