CHEMORESISTANCE RELATED TO HYPOXIA ADAPTATION IN MESOTHELIOMA CELLS FROM TUMOR SPHEROIDS

BACKGROUND

Hypoxia has been noted as a key factor for induction and maintenance of cancer stemness thereby leading to therapy resistance. Three-dimensional (3D) spheroid models demonstrate a heterogeneity of hypoxic regions replicating the in vivo situation within tumors. Utilizing an established 3D spheroid model, we investigated whether extrinsic hypoxia reinforced chemoresistance in malignant pleural mesothelioma (MPM) spheroids.

MATERIALS AND METHODS

Tumor spheres were generated from Meso-1 (a typical human MPM cell line) cells having high spheroid-forming ability. To induce hypoxia condition, we utilized a hypoxia chamber with regulation of O2 and CO2 levels. Cell viability was estimated by a WST-8 assay. Real-time polymerase chain reaction and Western blot were performed to evaluate the expression at mRNA and protein levels.

RESULTS

Compared with cells cultured in the two-dimensional monolayer model, tumor sphere cells showed elevated mRNA levels of cancer stemness markers (CD26, CD44 and ABCG2) and protein levels of the stemness and hypoxia adaptation markers (ABCG2, ALDH1A1 and HIFs). Correlating with this, 3D spheroid cells were more resistant to permetrexed and topotecan than the two-dimensional cells, indicative of their potential for hypoxic adaptation. Furthermore, significantly stronger resistance to both chemotherapeutic agents was observed in spheroid cells upon hypoxic challenge compared to spheroid cells under normoxia.

CONCLUSION

From the present data, it is concluded that hypoxia adaptation of MPM cells from tumor spheres could enhance their chemoresistance.

Deshima 2.0: Rapid Redshift Surveys and Multi-line Spectroscopy of Dusty Galaxies

We present a feasibility study for the high-redshift galaxy part of the Science Verification Campaign with the 220-440 GHz deshima 2.0 integrated superconducting spectrometer on the ASTE telescope. The first version of the deshima 2.0 chip has been recently manufactured and tested in the lab. Based on these realistic performance measurements, we evaluate potential target samples and prospects for detecting the [CII] and CO emission lines. The planned observations comprise two distinct, but complementary objectives: (1) acquiring spectroscopic redshifts for dusty galaxies selected in far-infrared/mm-wave surveys; (2) multi-line observations to infer physical conditions in dusty galaxies.

P5305Oxidized high-density lipoprotein is associated with progression of coronary artery calcification

Introduction

As a residual cardiovascular risk, high-density lipoprotein (HDL) is of great interest in lipid management. Native HDL has an anti-atherogenic role, while oxidized HDL (oxHDL) has atherogenic property because of reduced anti-inflammatory properties compared with native HDL. Meanwhile, recent studies showed that rapid progression of coronary artery calcification (CAC), a marker of subclinical atherosclerosis, was associated with greater incidence of cardiovascular events. However, the role of oxHDL in the pathogenesis of CAC remains unclear.

Purpose

The purpose of this study was to examine the association between the annual change in oxHDL and the progression of CAC (Agatston score) in a substudy of prospective multicenter randomized study.

Methods

In the principal study, patients with a CAC score of 1 to 999 were treated with pitavastatin with/without eicosapentaenoic acid. Measurement of CAC with MDCT and a blood test were performed at baseline and at the 1-year follow-up. The principal study showed 30–40% of annual change in CAC in all patients and no difference in the progression of CAC among treatment groups. In this substudy (n=140), patients were divided into 2 groups: CAC progression (change in Agatston score of >0, n=103) and no CAC progression (n=37). The serum concentration of oxHDL was measured using an antibody against oxidized human apoA-I with ELISA. The difference in oxHDL between patients with hypercholesterolemia and healthy subjects (n=30) was also evaluated.

Results

OxHDL levels were significantly lower in healthy subjects than in patients with hypercholesterolemia (150 [107–176] and 167 [132–246], respectively; median [25th-75th percentile], U/ml) (p=0.006). The baseline log-transformed oxHDL level was correlated with total cholesterol (r=0.21, p=0.01), HDL-cholesterol (r=0.33, p<0.01), and triglycerides (r=−0.21, p=0.01), but not correlated with age, body mass index, hemoglobinA1c, LDL-cholesterol, serum creatinine, or high-sensitivity C-reactive protein. After treatment, the oxHDL level significantly decreased from 167 (132–246) at baseline to 122 (103–149) (median [25th–75th percentile], U/ml) (p<0.001). The annual change in CAC was significantly positively associated with changes in oxHDL (r=0.17, p=0.04), triglycerides (r=0.17, p=0.04), and hsCRP (r=0.22, p=0.01) but not associated with changes in LDL-C or HDL-C. Multiple logistic analysis demonstrated that the decrease in oxHDL per 10 U/ml was independently associated with CAC progression after adjusting for variables including baseline oxHDL, LDL-cholesterol, Agatston score and current smoking (odds ratio, 0.95; 95% confidence interval, 0.90–0.99; p=0.04).

Conclusion

The decrease in oxHDL is associated with the attenuation of CAC progression, suggesting that oxHDL is a potential target for preventing atherosclerosis.

Relationship Between Stress Coping Mechanisms and Depression in Kidney Transplant Recipients

BACKGROUND

It has been reported that transplant recipients are exposed to physical and psychosocial stresses even after transplant surgery and exhibit psychological disorders such as depression.

PURPOSE

In this study, we extracted trends concerning how recipients of kidney transplants cope with stress, and we also examined how they cope with depression and its countermeasures.

METHOD

We administered questionnaire surveys to 109 kidney transplant recipients. These included items on personal attributes, medical information, depression, and stress-coping type scales. Statistical analysis was performed using factor analysis and multiple regression analysis.

RESULTS

Fifteen out of 109 (13.8%) were found to be high-risk patients for depression based on responses to the questionnaire using the depression scale. We extracted 2 factors of stress-coping type, namely Factor 1, "Directly coping with the problem," of patients who try to directly resolve the problem in a positive manner and Factor 2, "Stress-release while avoiding the problem," for those who relieve their feelings in response to the stress without resolving the problem itself. When multiple regression analysis was conducted with the depression scale as the dependent variable and the stress-coping factor as the independent variable, Factor 1 tended to be associated with reduced depression and Factor 2 with increased depression.

CONCLUSIONS

Results showed that to improve the mental health of those who receive kidney transplants, it is necessary to examine the depression and stress-coping types of such patients at an early stage and carry out education on stress-coping, focusing on resolving the actual problem.

The Effect of Three-Dimensional Preoperative Simulation on Liver Surgery

Background

In the past decade, three-dimensional (3D) simulation has been commonly used for liver surgery. However, few studies have analyzed the usefulness of this 3D simulation. The aim of this study was to evaluate the effect of 3D simulation on the outcome of liver surgery.

Methods

We retrospectively analyzed 240 consecutive patients who underwent liver resection. The patients were divided into two groups: those who received 3D preoperative simulation (“3D group”, n = 120) and those who did not undergo 3D preoperative simulation (“without 3D group”, n = 120). The perioperative outcomes, including operation time, blood loss, maximum aspartate transaminase level, length of postoperative stay, postoperative complications and postoperative mortality, were compared between the two groups. The predicted resected liver volume was compared with the actual resected volume.

Results

The median operation time for the 3D group was 36 min shorter than that for the without 3D group (P = 0.048). There were no significant differences in other outcomes between the two groups. A subgroup analysis revealed that the operation time of repeated hepatectomy and segmentectomy for the 3D group was shorter than that for the without 3D group (P = 0.03). There was a strong correlation between the predicted liver volume and the actual resected liver weight (r = 0.80, P < 0.001).

Conclusion

These findings demonstrate that 3D preoperative simulation may reduce the operation time, particularly for repeated hepatectomy and segmentectomy.

Antisense RNA transcripts in the blood may be novel diagnostic markers for colorectal cancer

Numerous genetic studies have been conducted regarding the occurrence of colorectal cancer (CRC) and the prognosis using microarrays. However, adequate investigations into the diagnostic application of microarrays have yet to be performed. The simplicity and accuracy of diagnosis and prognosis tracking are important requirements for its processes, and the use of blood cells for diagnosis is considered to be suitable to meet these requirements. The patients involved in the study were 28 preoperative patients with CRC and 6 healthy individuals who served as controls. RNA was extracted from the blood cells of the patients and analyzed using a sense/antisense RNA custom microarray. In the patients with CRC, the expression levels of 20 sense RNA and 20 antisense RNA species were identified as being significantly altered compared with that of the healthy volunteers (P<0.05; fold-change, >2.0). Cluster analysis of these RNA species revealed that the top 10 antisense RNAs significantly clustered patients with cancer and healthy individuals separately. Patients with stage I or II CRC exhibited significant changes in the expression levels of 33 sense and 39 antisense RNA species, as compared with healthy volunteers (P<0.01; fold-change >2.0). Cluster analysis demonstrated that patients with stage I or II CRC and healthy volunteers formed separate clusters only among the top 20 antisense RNA species. A tracking study of expression levels of haloacid dehalogenase-like hydrolase domain-containing 1 (HDHD1) antisense RNA was performed and a significant difference was identified between the CRC and healthy groups revealing that the levels at one week and three months following surgical removal of the cancerous tissue, decreased to almost same levels of the healthy individuals. The results of the current study indicate that HDHD1 antisense RNA may serve as a potential biomarker for the prognosis of CRC.

Three-dimensional simulation of pancreatic surgery showing the size and location of the main pancreatic duct

PURPOSE

We performed three-dimensional (3D) surgical simulation of pancreatic surgery, including the size and location of the main pancreatic duct on the resected pancreatic surface.

METHODS

The subjects of this retrospective analysis were 162 patients who underwent pancreatic surgery. This cohort was sequentially divided into a "without-3D" group (n = 81) and a "with-3D" group (n = 81). We compared the pancreatic duct diameter and its location, using nine sections in a grid pattern, with the intraoperative findings. The perioperative outcomes were also compared between patients who underwent pancreaticoduodenectomy (PD) and those who underwent distal pancreatectomy (DP).

RESULTS

There were no significant differences in the main pancreatic duct diameter between the 3D-simulated values and the operative findings. The 3D-simulated main pancreatic duct location was consistent with its actual location in 80 % of patients (65/81). In comparing the PD and DP groups, the intraoperative blood loss was 1174 ± 867 and 817 ± 925 ml in the without-3D group, and 828 ± 739 and 307 ± 192 ml in the with-3D group, respectively (p = 0.024, 0.026).

CONCLUSION

The 3D surgical simulation provided useful information to promote our understanding of the pancreatic anatomy, including details on the size and location of the main pancreatic duct.

Postcomparison of [(18) F]-fluorodeoxyglucose uptake in the brain after short-term bright light exposure and no intervention

OBJECTIVE

Bright light therapy is widely used as the treatment of choice for seasonal affective disorder. Nonetheless, our understanding of the mechanisms of bright light is limited and it is important to investigate the mechanisms. The purpose of this study is to examine the hypothesis that bright light exposure may increase [(18) F]-fluorodeoxyglucose (FDG) uptake in olfactory bulb and/or hippocampus which may be associated neurogenesis in the human brain.

METHOD

A randomized controlled trial comparing 5-day bright light exposure + environmental light (bright light exposure group) with environmental light alone (no intervention group) was performed for 55 participants in a university hospital. The uptake of [(18) F]FDG in olfactory bulb and hippocampus using FDG positron emission tomography was compared between two groups.

RESULTS

There was a significant increase of uptake in both right and left olfactory bulb for bright light exposure group vs. no intervention group. After adjustment of log-transformed illuminance, there remained a significant increase of uptake in the right olfactory bulb.

CONCLUSION

The present findings suggest a possibility that 5-day bright light exposure may increase [(18) F]FDG in the right olfactory bulb of the human brain, suggesting a possibility of neurogenesis. Further studies are warranted to directly confirm this possibility.

The Tight Adaptation at Pancreatic Anastomosis Without Parenchymal Laceration: An Institutional Experience in Introducing and Modifying the New Procedure

BACKGROUND

Among the types of pancreatic anastomosis used after pancreatoduodenectomy (PD), Blumgart type reconstruction has rapidly been distributed for its theoretical reasonableness, including secure tight adaptation of jejunal wall and pancreatic parenchyma without cause of parenchymal laceration. The clinical appropriateness of our modified Blumgart method was demonstrated by comparing to that of Kakita method.

METHODS

Retrospective analysis of 156 patients underwent elective open PD, reconstructed former 78 patients with the Kakita method, utilizing a full-thickness penetrating suture for tight stump adhesion. The later 78 patients were treated with the modified Blumgart method, which involved clamping the pancreatic parenchymal stump by the jejunal seromuscular layers with horizontal mattress-type penetration sutures. Evaluated variables were the rate of pancreatic fistula (PF) and the length of postoperative hospital stay (POHS).

RESULTS

The rate of ISGPF grade B+C PF was 29/78 (37.2%) in the Kakita group and 16/78 (20.5%) in the Blumgart group (P=0.033). The median POHS for the Kakita group was 23 days, whereas that for the Blumgart group was 16 days (P<0.001), one of the shortest value among Japanese high-volume centers. There was no perioperative intensive hemorrhage or deaths in either group.

CONCLUSION

A unique concept of Blumgart pancreatic anastomosis, i.e., utilizing the jejunum as an interstitial cushion to prevent pancreatic laceration at the knot site, has become realistic through a simple "one step" modification. This technique, also providing flexible handling space at main pancreatic duct anastomosis, should contribute to the improved PF prevention and shortening the POHS.

The Eltrombopag antitumor effect on hepatocellular carcinoma

Currently, sorafenib is the only available chemotherapeutic agent for advanced hepatocellular carcinoma (HCC), but it cannot be used in patients with liver cirrhosis (LC) or thrombocytopenia. In these cases, sorafenib is likely effective if given in combination with treatments that increase the number of platelets, such as thrombopoietin (TPO) receptor agonists. Increasing the platelet count via TPO treatment resulted in reduction of LC. Eltrombopag (EP), a TPO receptor agonist, has been reported to have antitumor effects against certain cancers, despite their lack of TPO receptor expression. We hypothesized that EP may possess antitumor activity against HCC in addition to its ability to suppress hepatic fibrosis by increasing the platelet count. In the present study, the antitumor activity of EP was examined by assessing the inhibition of cell proliferation and then ascertaining the ability of iron supplementation to reverse these effects in HepG2, Hep3B and Huh7 cells. In addition, a cell cycle assay was performed using flow cytometry, and signal transduction was evaluated by analyzing cell cycle-related protein expression. The results of EP were compared with those of the most common iron chelator, deferoxamine (DFO). The combined effect of EP and sorafenib was also assessed. The results revealed that EP exerts antitumor activity in HCC that is mediated by the modulation of intracellular iron content. EP suppressed the expression of the cell cycle-related protein cyclin D1 and elicited cell cycle arrest in the G0/G1 phase. The activity of EP was comparable to that of DFO in HCC, and EP did not compete with sorafenib at low concentrations. In conclusion, our findings suggest that EP is a good candidate chemotherapeutic agent for the treatment of HCC in patients with LC and thrombocytopenia.

Three-dimensional imaging identified the accessory bile duct in a patient with cholangiocarcinoma

The development of diagnostic imaging technology, such as multidetector computed tomography (MDCT) and magnetic resonance cholangiopancreatography (MRCP), has made it possible to obtain detailed images of the bile duct. Recent reports have indicated that a 3-dimensional (3D) reconstructed imaging system would be useful for understanding the liver anatomy before surgery. We have investigated a novel method that fuses MDCT and MRCP images. This novel system easily made it possible to detect the anatomical relationship between the vessels and bile duct in the portal hepatis. In this report, we describe a very rare case of extrahepatic cholangiocarcinoma associated with an accessory bile duct from the caudate lobe connecting with the intrapancreatic bile duct. We were unable to preoperatively detect this accessory bile duct using MDCT and MRCP. However, prior to the second operation, we were able to clearly visualise the injured accessory bile duct using our novel 3D imaging modality. In this report, we suggest that this imaging technique can be considered a novel and useful modality for understanding the anatomy of the portal hepatis, including the hilar bile duct.

Three-dimensional imaging identified the accessory bile duct in a patient with cholangiocarcinoma

The development of diagnostic imaging technology, such as multidetector computed tomography (MDCT) and magnetic resonance cholangiopancreatography (MRCP), has made it possible to obtain detailed images of the bile duct. Recent reports have indicated that a 3-dimensional (3D) reconstructed imaging system would be useful for understanding the liver anatomy before surgery. We have investigated a novel method that fuses MDCT and MRCP images. This novel system easily made it possible to detect the anatomical relationship between the vessels and bile duct in the portal hepatis. In this report, we describe a very rare case of extrahepatic cholangiocarcinoma associated with an accessory bile duct from the caudate lobe connecting with the intrapancreatic bile duct. We were unable to preoperatively detect this accessory bile duct using MDCT and MRCP. However, prior to the second operation, we were able to clearly visualise the injured accessory bile duct using our novel 3D imaging modality. In this report, we suggest that this imaging technique can be considered a novel and useful modality for understanding the anatomy of the portal hepatis, including the hilar bile duct.

Two γ-ray bursts from dusty regions with little molecular gas

Long-duration γ-ray bursts are associated with the explosions of massive stars and are accordingly expected to reside in star-forming regions with molecular gas (the fuel for star formation). Previous searches for carbon monoxide (CO), a tracer of molecular gas, in burst host galaxies did not detect any emission. Molecules have been detected as absorption in the spectra of γ-ray burst afterglows, and the molecular gas is similar to the translucent or diffuse molecular clouds of the Milky Way. Absorption lines probe the interstellar medium only along the line of sight, so it is not clear whether the molecular gas represents the general properties of the regions where the bursts occur. Here we report spatially resolved observations of CO line emission and millimetre-wavelength continuum emission in two galaxies hosting γ-ray bursts. The bursts happened in regions rich in dust, but not particularly rich in molecular gas. The ratio of molecular gas to dust (<9-14) is significantly lower than in star-forming regions of the Milky Way and nearby star-forming galaxies, suggesting that much of the dense gas where stars form has been dissipated by other massive stars.

Peritransplant absolute lymphocyte count as a predictive factor for advanced recurrence of hepatitis C after liver transplantation

Lymphocytes play an active role in natural immunity against hepatitis C virus (HCV). We hypothesized that a lower absolute lymphocyte count (ALC) may alter HCV outcome after liver transplantation (LT). The aim of this study was to investigate the impact of peritransplant ALC on HCV recurrence following LT. A total of 289 LT patients between 2005 and 2011 were evaluated. Peritransplant ALC (pre-LT, 2-week, and 1-month post-LT) and immunosuppression were analyzed along with recipient and donor factors in order to determine risk factors for HCV recurrence based on METAVIR fibrosis score. When stratifying patients according to pre- and post-LT ALC (<500/μL versus 500-1,000/μL versus >1,000/μL), lymphopenia was significantly associated with higher rates of HCV recurrence with fibrosis (F2-4). Multivariate Cox regression analysis showed posttransplant ALC at 1 month remained an independent predictive factor for recurrence (P = 0.02, hazard ratio [HR] = 2.47 for <500/μL). When peritransplant ALC was persistently low (<500/μL pre-LT, 2-week, and 1-month post-LT), patients were at significant risk of developing early advanced fibrosis secondary to HCV recurrence (F3-4 within 2 years) (P = 0.02, HR = 3.16). Furthermore, severe pretransplant lymphopenia (<500/μL) was an independent prognostic factor for overall survival (P = 0.01, HR = 3.01). The use of rabbit anti-thymocyte globulin induction (RATG) had a remarkable protective effect on HCV recurrence (P = 0.02, HR = 0.6) despite its potential to induce lymphopenia. Subgroup analysis indicated that negative effects of posttransplant lymphopenia at 1 month (<1,000/μL) were significant regardless of RATG use and the protective effects of RATG were independent of posttransplant lymphopenia.

CONCLUSION

Peritransplant ALC is a novel and useful surrogate marker for prediction of HCV recurrence and patient survival. Immunosuppression protocols and peritransplant management should be scrutinized depending on peritransplant ALC.

Effects of switching from calcium carbonate to lanthanum carbonate on bone mineral metabolism in hemodialysis patients

Phosphate binders are useful for the treatment of hyperphosphatemia in hemodialysis (HD) patients. This study was performed to examine the effects of switching from calcium carbonate (CC) to lanthanum carbonate (LC) on bone mineral metabolism and inflammatory markers in HD patients. We conducted 29 stable HD patients receiving CC, which was replaced by LC and followed-up for 12 weeks. Patients underwent determinants of blood chemistries such as serum calcium (Ca), phosphorus, parathyroid hormone (PTH) and vitamin D status, and interleukin-6 (IL-6) mRNA levels in whole blood cells were evaluated by real-time PCR just before and after the treatment with LC. Corrected Ca [corrected] levels were significantly reduced, but serum phosphorus levels (P levels) were unchanged after LC treatment. Switching to LC increased whole-PTH, osteocalcin, 1,25(OH)(2) D(3) levels and 1,25(OH)(2) D(3)/25(OH)D(3) ratio. 1,25(OH)(2) D(3)/25(OH)D(3) ratio was negatively correlated with HD duration. Furthermore, whole blood cell IL-6 mRNA levels were significantly reduced by LC treatment. We provided that the switching from CC to LC improved Ca overload and ameliorated vitamin D and inflammatory status in HD patients. These observations suggest that LC may play a protective role for the progression of atherosclerosis and vascular calcification in these patients.

Polypeptide N-acetylgalactosaminyl transferase 3 independently predicts high-grade tumours and poor prognosis in patients with renal cell carcinomas

BACKGROUND

The polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts) family of enzymes regulates the initial steps of mucin-type O-glycosylation. N-acetylgalactosaminyltransferases might show novel patterns of GalNAc-T glycosylation on tumour-derived proteins, which could influence cancer biology, but its mechanisms are unclear. We investigated the association of GalNAc-T3 and -T6 expressions with clinicopathological features and prognoses of patients with renal cell carcinomas (RCCs).

METHODS

Expressions of GalNAc-T3/6 and cell-adhesion molecules were analysed immunohistochemically in 254 paraffin-embedded tumour samples of patients with RCC.

RESULTS

Of 138 GalNAc-T3+ cases, 46 revealed significant co-expression with GalNAc-T6. N-acetylgalactosaminyltransferases-3+ expression showed a close relationship to poor clinical performance and large tumour size, or pathologically high Fuhrman's grading, and presence of vascular invasion and necrosis. The GalNAc-T3-positivity potentially suppressed adhesive effects with a significantly low β-catenin expression. Univariate and multivariate analyses showed the GalNAc-T3+ group, but not the GalNAc-T6+ group, to have significantly worse survival rates.

CONCLUSION

N-acetylgalactosaminyltransferases-3 expression independently predicts high-grade tumour and poor prognosis in patients with RCC, and may offer a therapeutic target against RCC.

Activation of the human multidrug resistance-1 (mdr1) gene promoter in response to inhibitors of DNA topoisomerases

The multidrug resistance (MDR1) gene encodes a Mr 170,000 energy-dependent membrane efflux pump termed P-glycoprotein, and the P-glycoprotein is often expressed in various human tumors before and after cancer chemotherapy. In this study, we have established a human cancer KB cell line (Kst-6) which stably expressed the CAT gene (pMDRCAT1) driven by the human MDR1 promoter. Exposure to inhibitors of DNA topoisomerase I (camptothecin: CPT-11) and II (etoposide: VP-16 and teniposide: VM-26) could efficiently induce CAT activities in both time- and dose-dependent manners. However, CAT activity could not be significantly induced when treated with an ATP-antagoist, novobiocin. Northern blot analysis showed about 5-fold increase in CAT mRNA levels in Kst-6 cells treated with CPT-11 or VP-16, but not with novobiocin. Proximal MDR1 promoter-binding activities of transacting factor were augmented in nuclear extracts from KB cells treated with CPT-11, VM-26, and VP-16.

Prognostic significance of BAF57 expression in patients with endometrial carcinoma

This study was conducted to elucidate the prognostic significance of BAF57 in patients with endometrial carcinoma. We investigated the relationship between the immunohistochemical expression of BAF57 and various clinicopathological variables in 111 endometrial carcinomas. Both univariate and multivariate regression analyses were performed. The correlations between the BAF57 expression and the other variables including estrogen receptor (ER) and p53 were examined. The high nuclear BAF57 expression was detected in 42 (37.8%) endometrial carcinomas, and 69 (62.2%) endometrial carcinomas were defined as having low nuclear BAF57 expression. The BAF57 expression was significantly associated with the surgical stage, grade of the tumor, myometrial invasion, lympho-vascular space invasion (LVSI) and lymph node metastasis. The 10-year overall survival rates of patients with low and high BAF57 expression were 96.9% and 58.2%, respectively (p<0.001). A multivariate analysis identified BAF57 expression as an independent prognostic factor. The BAF57 expression was significantly correlated with p53 expression (r=0.312, P=0.001), but was not correlated with ER expression (r= -0.141, P=0.14). The high BAF57 expression is an independent marker of poor prognosis of the patients in endometrial carcinomas. The inhibition of BAF57 activity may be one of the candidates for endometrial cancer therapy, especially therapy for aggressive tumors showing overexpression of p53.

Differential expression profiles of sense and antisense transcripts between HCV-associated hepatocellular carcinoma and corresponding non-cancerous liver tissue

Recent studies have demonstrated that natural antisense transcripts, which are complementary sequences to messenger RNA, have important cellular functions such as the stabilization and silencing of mRNA. However, the possible contribution of antisense transcripts in hepatocellular carcinoma (HCC) development has not been described. Therefore, we simultaneously investigated the sense and antisense transcripts of HCC and non-cancerous tissues to explore the possible contribution of antisense transcripts to HCC progression. RNA was prepared from 15 HCV-associated HCCs and from 6 corresponding non-cancerous tissues and was subjected to expression profile analysis of sense and antisense transcripts using a human custom microarray. Differential expression of 161 sense and 25 antisense transcripts was observed with more than 2-fold between HCC and non-cancerous tissue (p<0.001). The expression of the sense and antisense transcripts was used to cluster cancer and non-cancerous tissues, and the cancer and non-cancerous tissues were found to be clearly separated into different clusters. Additionally, the sense and antisense expression profiles were analyzed with regard to HCC differentiation (p<0.001), resulting in 71 sense and 43 antisense transcripts. These unique transcripts did not overlap with those found in the discrimination of HCC from non-cancerous tissues. When the HCC tissues were clustered by transcript expression, the antisense transcripts resulted in clustering of HCC that was consistent with grouping based on histology. These findings strongly indicate that the antisense transcripts together with the sense transcripts are involved in liver tumorigenesis.

P4-01-15: Alteration of Y-box Binding Protein-1 Expression Modifies the Response to Endocrine Therapy in Estrogen Receptor Positive Breast Cancer

Y-box binding protein-1 (YB-1) plays an important role in tumor progression and drug resistance. This study examined whether YB-1 is involved in the alteration of response to endocrine therapy in ER-positive breast cancer cells. MCF7 cells that stably expressed YB-1 (MCF7-YB-1) and vector control cells (MCF7-vector) were established. These cells were used to analyze the expression of the factors related to the ER and growth factor receptor signaling pathways, response to the antiestrogens (tamoxifen and fulvestrant), and estrogen responsive element (ERE) activity. The effect of knocking down endogenous YB-1 expression was tested in wild-type MCF7 cells. In addition, the expression of the YB-1 and the factors related to the ER and growth factor receptor signaling pathways were evaluated in the clinical breast cancers treated with preoperative chemotherapy. The expression of HER2, AIB1, p-Erk and c-Myc were increased in the MCF7-YB-1 cells. In contrast, knocking down of YB-1 decreased the expression of these factors, but increased the expression of ERα in the wild-type MCF7 cells. Furthermore, sensitivity to antiestrogens was decreased in the MCF7-YB-1 in comparison to those in the MCF7-vector cells. In the MCF7-YB-1 cells, the expression levels of p-Erk and c-Myc were continuously upregulated when the cells were treated either with tamoxifen or fulvestrant. The ERE activity was decreased in the MCF7-YB-1 cells in comparison to the MCF7-vector cells, and the ERE activity of the MCF7-YB-1 cells was inhibited by fulvestrant at a lower concentration than that which inhibited the ERE activity of the MCF7-vector cells. In the ER-positive clinical breast cancers treated with preoperative chemotherapy, significantly more of the specimens that showed increased or positive nuclear YB-1 expression after the chemotherapy were positive for HER2 expression. These data suggest that alteration of YB-1 may modify the crosstalk between the ER pathway and HER2 pathway in ER-positive breast cancer cells, and consequently may alter the response to endocrine therapy in these cells.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-01-15.

Overexpression of GalNAc-transferase GalNAc-T3 promotes pancreatic cancer cell growth

O-linked glycans of secreted and membrane-bound proteins have an important role in the pathogenesis of pancreatic cancer by modulating immune responses, inflammation and tumorigenesis. A critical aspect of O-glycosylation, the position at which proteins are glycosylated with N-acetyl-galactosamine on serine and threonine residues, is regulated by the substrate specificity of UDP-GalNAc:polypeptide N-acetylgalactosaminyl-transferases (GalNAc-Ts). Thus, GalNAc-Ts regulate the first committed step in O-glycosylated protein biosynthesis, determine sites of O-glycosylation on proteins and are important for understanding normal and carcinoma-associated O-glycosylation. We have found that one of these enzymes, GalNAc-T3, is overexpressed in human pancreatic cancer tissues and suppression of GalNAc-T3 significantly attenuates the growth of pancreatic cancer cells in vitro and in vivo. In addition, suppression of GalNAc-T3 induces apoptosis of pancreatic cancer cells. Our results indicate that GalNAc-T3 is likely involved in pancreatic carcinogenesis. Modification of cellular glycosylation occurs in nearly all types of cancer as a result of alterations in the expression levels of glycosyltransferases. We report guanine the nucleotide-binding protein, α-transducing activity polypeptide-1 (GNAT1) as a possible substrate protein of GalNAc-T3. GalNAc-T3 is associated with O-glycosylation of GNAT1 and affects the subcellular distribution of GNAT1. Knocking down endogenous GNAT1 significantly suppresses the growth/survival of PDAC cells. Our results imply that GalNAc-T3 contributes to the function of O-glycosylated proteins and thereby affects the growth and survival of pancreatic cancer cells. Thus, substrate proteins of GalNAc-T3 should serve as important therapeutic targets for pancreatic cancers.

Polypeptide N-acetylgalactosaminyltransferase 6 expression in pancreatic cancer is an independent prognostic factor indicating better overall survival

BACKGROUND

The family of polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts) is responsible for the altered glycosylation in cancer. The purpose of our study was to investigate the clinical significance of two isoforms, GalNAc-T6 and -T3, and their correlation with the prognosis of pancreatic cancer.

METHODS

Immunohistochemistry was used to analyse GalNAc-T6 and -T3 expressions in 70 clinicopathologically characterised pancreatic cancer cases.

RESULTS

Positive expressions of GalNAc-T6 and -T3 were immunohistochemically identified in 51% (36 of 70) and in 77% (54 of 70) of patients, respectively. A close relationship was noted between GalNAc-T6 positive expression and pathological well/moderate differentiated type (P=0.001), small tumour size (P=0.044), absence of vascular invasion (P=0.009), and low stage of the American Joint Committee on Cancer systems (P=0.043). The expression of GalNAc-T3 significantly correlated with good differentiation (P=0.001), but not with other clinicopathologic features. Furthermore, univariate and multivariate analyses revealed that GalNAc-T6 expression was an independent prognosis indicator for the disease, whereas GalNAc-T3 expression had no impact on clinical outcome, even though 33 of 36 GalNAc-T6-positive cases also had a positive expression of GalNAc-T3 (P=0.001, r=0.356).

CONCLUSION

Both GalNAc-T6 and -T3 expressions correlated significantly with tumour differentiation, whereas only GalNAc-T6 expression predicted prognosis in pancreatic cancer.

Comprehensive expressional analyses of antisense transcripts in colon cancer tissues using artificial antisense probes

Background

Recent studies have identified thousands of sense-antisense gene pairs across different genomes by computational mapping of cDNA sequences. These studies have shown that approximately 25% of all transcriptional units in the human and mouse genomes are involved in cis-sense-antisense pairs. However, the number of known sense-antisense pairs remains limited because currently available cDNA sequences represent only a fraction of the total number of transcripts comprising the transcriptome of each cell type.

Methods

To discover novel antisense transcripts encoded in the antisense strand of important genes, such as cancer-related genes, we conducted expression analyses of antisense transcripts using our custom microarray platform along with 2376 probes designed specifically to detect the potential antisense transcripts of 501 well-known genes suitable for cancer research.

Results

Using colon cancer tissue and normal tissue surrounding the cancer tissue obtained from 6 patients, we found that antisense transcripts without poly(A) tails are expressed from approximately 80% of these well-known genes. This observation is consistent with our previous finding that many antisense transcripts expressed in a cell are poly(A)-. We also identified 101 and 71 antisense probes displaying a high level of expression specifically in normal and cancer tissues respectively.

Conclusion

Our microarray analysis identified novel antisense transcripts with expression profiles specific to cancer tissue, some of which might play a role in the regulatory networks underlying oncogenesis and thus are potential targets for further experimental validation. Our microarray data are available at http://www.brc.riken.go.jp/ncrna2007/viewer-Saito-01/index.html.

Identification of natural antisense transcripts involved in human colorectal cancer development

Natural antisense transcripts (NATs) constitute a class of non-coding RNAs that have emerged as important regulators of gene expression. However, involvement of NATs in colorectal cancer (CRC) development has not been reported to date. In the present study, the up- and down-regulation of NATs were investigated in human CRC for their possible involvement in CRC development. Total RNAs isolated from 51 CRC tissues, 9 corresponding non-cancerous tissues and 19 liver metastatic tissues from surgically resected samples were subjected to expression analysis using a custom-microarray containing human sense/antisense probes for ca. 21,000 genes. Comparing CRC tissues with non-cancerous tissues, we identified 415 NATs differentially expressed in CRC and non-cancerous tissues to a significant degree (p<0.001, fold change >4.0 or ≤4.0). When a hierarchical clustering was performed on CRC and non-cancerous samples using these 415 NATs, the samples were separately clustered. Principal component analysis with the same NATs showed clear separation of CRC and non-cancerous samples using the first two principal components (PC1, 80%; PC2, 10%). To validate the expression results obtained from the microarray, the expressions of the 3 selected NATs were examined by strand-specific RT-qPCR, revealing that these expression profiles were consistent with those obtained from microarray analysis. In addition, the NAT expression patterns were found to be different between primary tumors with liver metastasis and those without liver metastasis. In conclusion, these findings taken together indicated that NATs identified in the present study would be involved in CRC development as well as possibly in its metastasis.

Elevation and characteristics of Rab30 and S100a8/S100a9 expression in an early phase of liver regeneration in the mouse

Recent studies have revealed that cytokines, including TNFα and IL-6 play key roles in the priming phase of liver regeneration. However, further knowledge of molecular events in the priming phase is needed for more comprehensively understanding the initiation of liver regeneration. In the present study, we attempted to identify additional genes involved in an early phase (2-6 h post partial hepatectomy, PH). The expression of 71 genes was shown to be up-regulated more than 3-fold in the liver at 2 h and 6 h post PH, as compared to 0 h (normal livers) using microarray analysis. Among them, Rab30 and S100a8/S100a9, were identified as novel genes up-regulated over 20-fold at 2 h post PH as compared to normal liver, and were further examined by RT-qPCR to confirm microarray results. Rab30 showed no significant up-regulation in organs other than the liver, whereas S100a8/S100a9 showed significant up-regulation in other organs, such as the lung and spleen at 6 h post PH as compared to those of sham-operated mice, indicating the existence of a different up-regulation machinery between Rab30 and S100a8/S100a9. Their expression was further investigated in the liver at various developmental stages. Rab30 was shown to be expressed only in newborn liver, whereas S100a8/S100a9 was highly expressed in embryo stages, and exhibited the highest levels in newborn liver. These findings imply that Rab30 and S100a8/S100a9 are possibly involved in the functional switch from hematopoiesis support to metabolism in the newborn stage, but might play different roles in liver development. In conclusion, Rab30 and S100a8/S100a9 were indicated to play roles in the initiation of liver regeneration as well as possibly in the functional switch of the liver in the newborn stage.

Platelets prevent acute hepatitis induced by anti-fas antibody

BACKGROUND AND AIM

Platelets provide many functions in the body, especially to the liver. The purpose of this study is to investigate the effect of thrombocytosis with acute hepatitis induced by anti-Fas antibody and its mechanism.

METHODS

Acute hepatitis was induced by administration of anti-Fas antibody in normal and thrombocytotic C57BL6J mice. For thrombocytosis, thrombopoietin; PEG-rHuMGDF was injected 5 days before and just prior to administration of anti-Fas antibody. To investigate the mechanisms, hepatocyte cell line (AML12) and sinusoidal endothelial cell line (M1) were induced apoptosis by staurosporine. They were cultured with platelets or thrombopoietin. Examination items were as follows: platelet number, alanine aminotransferase (ALT), histological findings, TUNEL (TdT-mediated dUTP-biotin Nick End Labeling) staining, and the expression of proteins associated with apoptosis in vivo and in vitro.

RESULTS

Platelets were significantly increased in the thrombocytotic group (P < 0.01). Serum ALT levels were significantly reduced by thrombocytosis at 6, 24 and 72 h after the administration (P < 0.05). In histological findings, hemorrhagic necrosis was observed in the normal group, but not observed in the thrombocytotic group. TUNEL-positive hepatocytes were reduced and the expression of cleaved caspase-3 was significantly decreased in the thrombocytotic group. The phosphorylation of Akt, the increment of Bcl-xL and the decrease of cleaved caspase-3 were observed in AML12 cells cultured with platelets, but were not observed cultured with thrombopoietin. Platelets and thrombopoietin had no anti-apoptotic effect on M1 cells.

CONCLUSION

Increase of platelets has a preventative effect against acute hepatitis induced by the anti-Fas antibody. It is suggested that platelets have a direct protective effect against apoptosis of hepatocytes.

Increased Nuclear Localization of Transcription Factor Y-Box Binding Protein 1 Accompanied by Up-Regulation of P-Glycoprotein in Breast Cancer Pretreated with Paclitaxel

Purpose: The Y-box binding protein 1 (YB-1) regulates expression of P-glycoprotein (P-gp) encoded by the MDR1 gene. There have been no previous studies regarding the involvement of YB-1 in the development of resistance to paclitaxel. The present study was performed to examine how paclitaxel affects the localization and expression of YB-1 in breast cancer.Experimental Design: We evaluated the expression and localization of YB-1 and P-gp in breast cancer tissues obtained from 27 patients before and after treatment with paclitaxel. The effect of paclitaxel on localization of cellular YB-1 was examined by using GFP-YB-1. Interaction of YB-1 with the Y-box motif of the MDR1 promoters was studied by EMSA. The effects of paclitaxel on MDR1 promoter activity were examined by luciferase assay.Results: Of 27 breast cancer tissues treated with paclitaxel, nine (33%) showed translocation of YB-1 from the cytoplasm to the nucleus together with increased expression of P-gp during the course of treatment. Twelve breast cancer tissues (44%) showed neither translocation of YB-1 nor increased expression of P-gp. Nuclear translocation of YB-1 was correlated significantly with increased expression of P-gp (P=0.0037). Confocal analysis indicated that paclitaxel induced nuclear translocation of green fluorescent fused YB-1 in MCF7 cells. Furthermore, binding of YB-1 to the Y-box of MDR1 promoter was increased in response to treatment with paclitaxel. In addition, MDR1 promoter activity was significantly up-regulated by paclitaxel in MCF7 cells (p&lt; 0.001).Conclusions: The results of the present study suggested that YB-1 may be involved in the development of resistance to paclitaxel in breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1141.