Regulation of the centrosome cycle

The centrosome, consisting of mother and daughter centrioles surrounded by the pericentriolar matrix (PCM), functions primarily as a microtubule organizing center (MTOC) in most animal cells. In dividing cells the centrosome duplicates once per cell cycle and its number and structure are highly regulated during each cell cycle to organize an effective bipolar spindle in the mitotic phase. Defects in the regulation of centrosome duplication lead to a variety of human diseases, including cancer, through abnormal cell division and inappropriate chromosome segregation. At the end of mitosis the daughter centriole disengages from the mother centriole. This centriole disengagement is an important licensing step for centrosome duplication. In S phase, one new daughter centriole forms perpendicular to each centriole. The centrosome recruits further PCM proteins in the late G2 phase and the two centrosomes separate at mitotic entry to form a bipolar spindle. Here, we summarize research findings in the field of centrosome biology, focusing on the mechanisms of regulation of the centrosome cycle in human cells.

Inhibition of invasion by glycogen synthase kinase-3 beta inhibitors through dysregulation of actin re-organisation via down-regulation of WAVE2

Cancer cell invasion is a critical phenomenon in cancer pathogenesis. Glycogen synthase kinase-3β (GSK-3β) has been reported to regulate cancer cell invasion both negatively and positively. Thus, the net effect of GSK-3β on invasion is unclear. In this report, we showed that GSK-3β inhibitors induced dysregulation of the actin cytoskeleton and functional insufficiency of focal adhesion, which resulted in suppressed invasion. In addition, WAVE2, an essential molecule for actin fibre branching, was down-regulated after GSK-3β inhibition. Collectively, we propose that the WAVE2-actin cytoskeleton axis is an important target of GSK-3β inhibitors in cancer cell invasion.

Aggressive surgical treatment with bony pelvic resection for locally recurrent rectal cancer

BACKGROUND

In the current era of total mesorectal excision, local relapse remains a main cause of recurrence. Although standard treatment for locally recurrent rectal cancer (LRRC) has not been established, R0 resection represents the only potentially curative treatment. However, extended surgery accompanying bony pelvic resection is technically demanding and is still challenging.

METHODS

Studied were 35 patients with LRRC who underwent combined resection of bony pelvis between August 2006 and October 2013. Safety and prognostic factors for survival were analyzed. Median follow-up was 33 months.

RESULTS

Sacrectomy was performed in 32 patients and 3 patients underwent combined resection of the pubis and ischium. The dominant operative procedure was total pelvic exenteration in 30 (86%) patients. R0 resection was achieved in 27 (77%) patients. No patients died. Pelvic sepsis was the most frequent complication (40%). Recurrence developed in 20 (57%), with the lung the most frequent site (10 patients). Three-year local relapse-free survival (LRFS) and disease-free survival (DFS) were 72.1% and 32.7%, respectively. On multivariate analysis, R1 resection was the only independent risk factor for local recurrence (p = 0.010), and concomitant liver metastasis and initial non sphincter-preserving surgery were independent predictors of worse DFS (p = 0.008 and p = 0.042, respectively).

CONCLUSIONS

Aggressive surgical treatment combined with bony resection for carefully selected patients with LRRC was safe with a high rate of R0 resection and favorable LRFS. However, DFS was not satisfactory even after R0 resection and the main cause was lung metastasis. Preventing distant recurrence might be a key to improve survival.

Missense variants of the alanine: glyoxylate aminotransferase 2 gene correlated with carotid atherosclerosis in the Japanese population

Alanine:glyoxylate aminotransferase 2 (AGXT2; EC 2.6.1.44) degrades asymmetric dimethylarginine (ADMA), a competitive inhibitor of nitric oxide (NO) synthase. Increased ADMA, reduced NO, and hypertension are shown in Agxt2 knockout mice. There are four single nucleotide polymorphisms (rs37370, rs37369, rs180749, and rs16899974) with which AGXT2 activity changes in humans and may be related to vulnerability of vascular sclerosis. To examine the relationship between them, we studied the functional haplotypes of the AGXT2 gene and decided their relationship with arteriosclerotic changes via carotid intima-media thickness (carotid IMT) in Japanese subjects. Genotyping of those polymorphisms and the carotid IMT in 1,426 Japanese subjects were then evaluated. Subjects with C-A-A-A haplotype (rs37370, rs37369, rs180749, rs16899974) showed low AGXT2 activity (P<0.0001; Pearson’s correlation coefficients: 0.497). The C-A-A-A haplotype was significantly associated with mean carotid IMT (P=0.049) and max carotid IMT (P=0.004). Subjects with two C-A-A-A haplotypes exhibited thicker mean carotid IMT (P=0.022) and maximum carotid IMT (P=0.001). In multiple regression analysis, subjects with two C-A-A-A haplotypes were independently and positively associated with mean carotid IMT (P=0.02) and maximum IMT (P=0.005) after correction. There was a significant correlation between the functional variants in the AGXT2 gene and carotid IMT in Japanese. The AGXT2 genotype may be an important factor underlying atherosclerosis.

S100A4, frequently overexpressed in various human cancers, accelerates cell motility in pancreatic cancer cells

S100A4, a member of the Ca(2+) dependent S100 protein family, is reported to associate with metastasis through regulation of the motility and invasiveness of cancer cells. A high level of S100A4 protein has been reported in a variety of cancers, including pancreatic cancer. However, its biological role in pancreatic carcinogenesis is largely unknown. We previously reported that S100A4 is frequently overexpressed and that RNAi-mediated knockdown induces apoptosis and suppression of cell growth, motility, and invasiveness. In this study, we analyzed the effects of forced expression of S100A4 in pancreatic cancer cell lines without S100A4-upregulation. We used two cell lines without upregulation of S100A4 (PCI-35 and PCI-43) as well as two cell lines with highly upregulated S100A4 as the control (MIA PaCa-2 and PAN-07-JCK). Cells did not show acceleration of their growth and invasiveness after forced expression of S100A4, but remarkable acceleration of cell motility was observed only in PCI-35 and PCI-43. We further performed microarray analyses using PCI-35 and PCI-43 with and without forced expression of S100A4 and identified 72 and 18 genes that were 2-fold or more upregulated or downregulated, respectively, in both cell lines after forced expression of S100A4. Our results suggest that S100A4 is crucial for cell motility in pancreatic cancer and that some downstream genes may play important roles in cell motility.

Production of antioxidant vitamins, beta-carotene, vitamin C, and vitamin E, by two-step culture of Euglena gracilis Z

Euglena gracilis Z is one of the few microorganisms which simultaneously produces antioxidant vitamins such as beta-carotene and vitamins C and E. Photoheterotrophically cultured E. gracilis Z produced larger levels of biomass but with a lower content of antioxidant vitamins than photoautotrophically grown cultures. For efficient production of these vitamins, a two-step culture was performed. Cells were grown photoheterotrophically and then transferred to photoautotrophic conditions. When E. gracilis Z cells were grown in fed-batch culture under photoheterotrophic conditions, their density reached 19 g/L after 145 h. Subsequent transfer of these cells to photoautotrophic conditions increased vitamin content, enhancing the total vitamin yields, which were 71.0 mg/L of beta-carotene, 30.1 mg/L of vitamin E, and 86.5 mg/L of vitamin C. (c) 1997 John Wiley & Sons, Inc.

Clinical outcome of recombinant human soluble thrombomodulin (rTM) for patients with disseminated intravascular coagulation (DIC) complicating advanced solid cancer: Retrospective analysis

e19611

Background: Disseminated intravascular coagulation (DIC) is a syndrome characterized by the activation of coagulation leading to systemic microvascular thrombosis. DIC is frequently observed in patients with hematologic malignancy and often in patients with advanced cancer. Recombinant human soluble thrombomodulin (rTM) has been introduced as a new type of anti-DIC agent for clinical use in patients with hematological cancer or infectious disease. However, the efficacy for advanced solid cancer has not been elucidated. Methods: All patients with DIC complicating advanced solid cancer who were treated by rTM in Tohoku university hospital from December 2009 to November 2011 were enrolled in this retrospective study. DIC was diagnosed and scored according to the diagnostic criteria established by the Japanese Ministry of Health and Welfare (JMHW DIC criteria). Change in DIC score and period of overall survival (OS) after treatment of rTM (380U/kg/day) were evaluated. The Kaplan-Meier method was used to calculate OS. Results: Twenty-two patients (32% female) were enrolled. The median age was 61.5 (r: 32-82). The primary organs were 7 stomach, 3 colorectal, 2 esophageal and 10 other cancers. DIC score (63.6%), FDP (54.5%), PT-INR (45.4%), FBG (36.4%) were kept or improved in these patients between day 1 and day 5 in rTM treatment. Median OS (mOS) was 30 days (r: 2–301). Subgroup analyses revealed that mOS was longer in patients who underwent chemotherapy following rTM treatment than in patients who did not (114 days vs. 10 days, p = 0.0083). Patients with better ECOG PS (<2 vs. >3; 114 days vs. 15 day, p = 0.018), smaller number of chemotherapy treated before DIC (<2 vs. >3; 69 days vs. 6 days, p = 0.0008) also showed better mOS. No critical complication was observed. Conclusions: This study showed that rTM was effective and safe for patients with DIC complicating advanced solid cancer. PS and number of chemotherapy regimens could be predictive factor of rTM. We considered that rTM yield the chance of chemotherapy to advanced cancer patients with DIC by preventing deterioration of DIC.

DCK is frequently inactivated in acquired gemcitabine-resistant human cancer cells

Although gemcitabine is the most effective chemotherapeutic agent against pancreatic cancer, a growing concern is that a substantial number of patients acquire gemcitabine chemoresistance. To elucidate the mechanisms of acquisition of gemcitabine resistance, we developed gemcitabine-resistant cell lines from six human cancer cell lines; three pancreatic, one gastric, one colon, and one bile duct cancer. We first analyzed gemcitabine uptake using three paired parental and gemcitabine resistant pancreatic cancer cell lines (PK-1 and RPK-1, PK-9 and RPK-9, PK-59 and RPK-59) and found that uptake of gemcitabine was rapid. However, no DNA damage was induced in resistant cells. We further examined the microarray-based expression profiles of the cells to identify genes associated with gemcitabine resistance and found a remarkable reduction in the expression of deoxycytidine kinase (DCK). DCK is a key enzyme that activates gemcitabine by phosphorylation. Genetic alterations and expression of DCK were studied in these paired parental and derived gemcitabine-resistant cell lines, and inactivating mutations were found only in gemcitabine-resistant cell lines. Furthermore, siRNA-mediated knockdown of DCK in the parental cell lines yielded gemcitabine resistance, and introduction of DCK into gemcitabine-resistant cell lines invariably restored gemcitabine sensitivities. Mutation analyses were expanded to three other different paired cell lines, DLD-1 and RDLD-1 (colon cancer cell line), MKN-28 and RMKN-28 (gastric cancer cell line), and TFK-1 and RTFK -1 (cholangiocarcinoma cell line). We found inactivating mutations in RDLD-1 and RTFK-1 and decreased expression of DCK in RMKN-28. These results indicate that the inactivation of DCK is one of the crucial mechanisms in acquisition of gemcitabine resistance.

Internal Stress of ZnO thin Films Caused by Thickness Distribution and Crystallinity

The improvement of thickness distribution and crystallinity in ZnO thin films prepared by radio frequency (rf) planer magnetron sputtering has been studied. Optimum thickness distribution of less than ± 2.2% in a 3-inch wafer is obtained by changing the substrate angle to the ZnO target and is in accordance with cosine law. The c-axis orientation perpendicular to the silicon substrate is confirmed by x-ray diffraction. The stress of ZnO thin films is larger than 0.3GPa and its distribution is independent of the substrate angle that is set at a slant to the optimum angle for thickness distribution. These results indicate that thickness distribution of ZnO thin films heavily depends on the substrate angle, while the stress and its distribution are independent of the setting angle of the substrate. Stress distribution is attributed to the distribution of argon ions and sputtered molecules impinging a wafer.

Transversal Type Piezoelectric Resonator Using ZnO Thin Film on Micro-Fabricated Elinver (Fe-Ni-Cr-Ti) Alloy

A transversal type 3.58MHz piezoelectric resonator has been fabricated using piezoelectric ZnO thin film on ELINVER (Fe-Ni-Cr-Ti ) alloy. The ZnO/ELINVER structure piezoelectric resonator has been designed to have 2 ppm temperature coefficient of frequency (TCF) per degree from -20 degrees to 80 degrees centigrade. The temperature coefficient of ELINVER alloy can be controlled to cancel the TCF of ZnO thin film by heat annealing. The ZnO thin film on ELINVER alloy shows c-axis orientation. The c-axis orientation of the ZnO thin film is strongly influenced by the surface roughness of the ELINVER alloy. The wet etching process has been adopted to shape the resonator made from ELINVER alloy substrate. The cross section of the resonator is a structure tapered about 10 degrees, created using different sized photo masks on each side of the ELINVER surface. The tapered cross section of the transversal type resonator greatly improves the frequency characteristics of the resonator. The electrical characteristics of the resonator after the improvement include a resonance frequency of 3.58MHz trimmed by a YAG laser, and resonance resistance of about 200 Ω. The temperature coefficient of frequency is about 1.5 ppm per degree at a temperature range of-20 degrees to 80 degrees centigrade.

Transmission Electron Microscopy Stjudy of Initerface Microstrucure in ZnO Thin Films Grown on Various Substrates (Glass,Au,Sl,α-Al2O3)

Zinc oxide (ZnO) thin films have been grown by radio frequency sputtering on glass, Al, Au and R cut sapphire substrates. Microstructures of the ZnO / substrate interface have been observed by transmission electron microscope. The purpose of this study is to elucidate the crystal growth mechanism of ZnO thin films using various substrates that have different crystallinity and crystal structures. An amorphous layer with a thickness of about 5 nm is observed at the ZnO/glass interface, and c axis orientation perpendicular to the substrate is observed on this amorphous layer. Mianstructurts at the ZnO/buffer metal interface, on the other hand, are significantly different from those of ZnO/glass interface. A thick amorphous layer of about 15 nm is observed at the ZnO/Al interface, presumably consisting of Al2O3 interface layer material. ZnO thin film grown on Au buffer layers is distinctly different from both ZnO on glass and Al. No amorphous layer is formed at the ZnO/Au interface, and c axis orientation begins directly from the Au surface. Epitaxially grown ZnO thin film is confirmed on a R-cut sapphire substrate. These results dearly demonstrate that ZnO thin films prepared by radio frequency sputtering are strongly influenced by the substrate surface crystallinity at the topmost layer of the substrate.

[Solitary fibrous tumor of the seminal vesicle]

A 56-year-old man presented to our hospital with a pelvic mass. The tumor was diagnosed to occur from right seminal vesicle and to be a benign solitary fibrous tumor by transrectal tumor biopsy. The tumor enlarged during follow up, and he under-went resection of the tumor.

Abstract 5295: S100A4 regulates tumor growth, motility, and invasion in pancreatic cancer

S100A4 protein belongs to the S100 subfamily, which has grown to be one of the large subfamilies of the EF-hand Ca2+-binding proteins, and overexpression of S100A4 is suggested to associate with cell proliferation, invasion, and metastasis. We observed frequent overexpression of S100A4 in pancreatic cancer cell lines by quantitative real-time RT-PCR and Western blotting. Tissue microarray analysis validated S100A4 overexpression in primary pancreatic cancer tissues, and overexpression of S100A4 associated with perineural invasion. We further analyzed RNAi-mediated knockdown to address the possibility of its use as a therapeutic target for pancreatic cancer. The specific knockdown of S100A4 strongly suppressed cell growth, induced G2 arrest and eventual apoptosis, and decreased cell migration. Furthermore, microarray analyses revealed that knockdown of S100A4 induced expression of the tumor suppressor genes PRDM2 and VASH1. We further established stably S100A4-expressing cell lines using two pancreatic cancer cell lines with low level of S100A4 expression; remarkable accelerated cell growth and motility was observed after induction of S100A4, whereas no change was observed in the control cells. Comparison of the expressional profiles after siRNA-mediated knockdown and expression vector-mediated induction is underway, and the results will also be demonstrated and discussed.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5295.