Thiazolidenediones induce tumour-cell apoptosis through the Akt-GSK3β pathway

WHAT IS KNOWN AND OBJECTIVE

Prostate cancer is a major health threat for men. Thiazolidenediones (TZDs) are synthetic ligands of the peroxisome proliferator-activated receptor γ (PPARγ), and previous studies have shown that TZDs induce apoptosis of prostate cancer cells independently of PPARγ activation. However, the exact mechanism of these effects remains unknown. Our objective was to investigate the effects of TZDs on apoptosis and on the serine/threonine kinase pathway, Akt, and glycogen synthase kinase 3β (GSK3β).

METHODS

LNCaP cells, a type of prostate cancer cells (derived from left supraclavicular lymph node of human prostrate carcinoma), were cultured in DMEM medium, and cell viability was evaluated with a colorimetric assay using MTT level. The total and phosphorylated protein level of Akt and GSK3β were detected by Western blotting.

RESULTS AND DISCUSSION

The apoptosis-inducing effect of TZDs on prostate cancer cells involves the inhibition of Akt phosphorylation. Furthermore, TZDs induce inactivation of GSK3β, a multifunctional kinase that mediates essential events promoting prostate cancer development and acquisition of androgen independence. In addition, the GSK3β inhibitor lithium chloride sensitizes prostate cancer cells to TZDs cytotoxicity.

WHAT IS NEW AND CONCLUSION

Our data suggest that modulation of Akt-GSK3β pathway is involved in the cell death pathway engaged by TZDs in prostate cancer cells. This reveals another possible mechanism of TZDs on apoptosis in prostate cancer. Inhibition of the Akt-GSK3β cascade may be a useful approach in prostate cancer.

Abstract P3-12-08: Molecular Breast Cancer Subtypes in Women from Northeast China: Eight-Year Retrospective Study about Clinicopathologic Features and Survival

Background and objectives: Analysis of gene expression has identified various molecular subtypes. These molecular subtypes defined by immunohistochemistry expression of estrogen receptor (ER) or progesterone receptor (PR) and human epidermal growth factor receptor 2 (Her2) : luminal A, luminal B, basal cell-like and HER2-expresing. This study evaluates clinical and pathologic features and survival of the four molecular subtypes in premenopausal and postmenopausal women from northeast China.

Methods: A retrospective analysis of 1214 women diagnosed with breast cancer from 2000 to 2007 in Breast Surgery Department, First Hospital of Jilin University. Four molecular breast cancer subtypes defined as: luminal A (ER+ and/or PR+, HER2-), luminal B (ER+ and/or PR+, HER2+), basal-like (ER-, PR-, HER2-), and HER2-expresing, (ER-, PR-, and HER2+). We examined the prevalence of breast cancer subtypes and analyzed the associations with patient clinicopathologic features: age, menopausal status, tumor size, lymph node status, stage of cancer at diagnosis, histological characteristics, and breast cancer-specific survival.

Results: Among the all cases, the luminal A subtype was the most prevalent in our study sample (56.0%) compared with basal -like (18.5%), luminal B (13.7%), and HER2-expresing subtypes (11.8%). The four molecular subtypes differed significantly by menopausal status (P=0.011), age (P<0.001) and lymph node status (P<0.001). Luminal A subtype was more likely to with Stage II breast cancer (P<0.001) and most present with size of 2.1-5 cm (P<0.001). The luminal B and the HER2-expresing subtypes presented an increased association with more aggressive clinical course when compared with others subtypes. The estimated median follow-up period for all subjects was 54 months (range, 1 month to 120 months). The 8-year overall survival for all patients was 81.3% (95%CI, 79.4-83.7) and disease-free survival was 77.8% (95% CI, 75.4-79.9). The Kaplan-Meier curve showed breast cancer-specific survival differed significantly among the molecular subtypes (P < 0.03), with the luminal B and HER2-expresing subtypes having the poorest outcome.

Conclusion: Luminal A breast tumor appeared the better outcome than the others three subtypes and the shortest survival was HER2-expresing subtype. The poor clinical outcomes of luminal B subtype with women from northeast China were different from those of Western women could contribute to the poor prognosis of breast cancer observed in this cohort of patients and some of them couldn't accept molecular targeted therapy with trastuzumab by poor economic situations.

Figure available in online version.

Abstract P6-05-05: Signaling Pathways Activated in Her 2 and ER Negative Breast Cancers

Introduction: Breast cancer is the most common cancer in women (192,370 new cases in 2009) and the second leading cause of cancer death (40,000) among women in USA. Current multimodality treatment of breast cancer is based on the level of ER expression and Her 2 gene amplification. However, no effective treatment is currently available for breast cancers with low level expression of ER and no amplification of Her 2 gene. The aim of this study is to identify protein pathways activated in the breast cancer with negative expression of ER and Her 2. Method: Protein Pathway Array was used to assess the level of protein expression and phosphorylation in 71 paired fresh frozen breast samples (tumor and adjacent benign tissue). A total 159 antibodies were evaluated which represent most important signal transduction pathways involved in proliferation, apoptosis, angiogenesis, invasion and metastasis. Several potential therapeutic kinase proteins were also assessed. Results: A total 20 proteins (PCNA, phospho-PTEN, cyclin B1 cyclin E1, CDK6, E-cadherin, NFkB, ect) were differentially expressed between normal and tumor tissues based on the statistical analysis. In Her 2 negative tumors (n=37), 3 proteins were differentially expressed and among them, 2 were up-regulated (CDK6 and HSD1) and 1 was down-regulated (IGF). In ER negative tumors (n=18), 4 proteins (HSD, SK, TDP and Slug) was up-regulated and 1 proteins were down-regulated (E-cadherin). In triple negative tumors (n=13), one protein (E-cadherin) down-regulated and 2 proteins (TDP and HSD) were up-regulated. Furthermore, based on the expression pattern of these proteins, tumors negative for both ER and Her 2 (n=15) can be clustered into 3 groups

Figure 1: Subclassification of breast cancers negative for ER and Her-2 based protein pattern.

Hierarchical clustering analysis of 20 differentially expressed proteins in

15 ER/Her-2 negative breast cancers. The cancers can be separated into 3 subtypes. Red indicates overexpression, green underexpression, black no change, and gray no expression. Each column represents a protein. Each row represents a sample.

Conclusion: Our study showed that distinct sets of signaling pathways activated in ER and Her 2 negative breast cancers. The increased expression of cell cycle progression proteins in Her 2 negative tumors suggests activation of cell proliferation via different growth promotion pathway. Similarly, different cell proliferation pathways are also activated in ER negative tumors. This finding may be used to design future clinical trial based on the activation of different signaling pathways.

Calcitonin impairs the anabolic effect of PTH in young rats and stimulates expression of sclerostin by osteocytes

The therapeutic goal of increasing bone mass by co-treatment of parathyroid hormone (PTH) and an osteoclast inhibitor has been complicated by the undefined contribution of osteoclasts to the anabolic activity of PTH. To determine whether active osteoclasts are required at the time of PTH administration, we administered a low dose of the transient osteoclast inhibitor salmon calcitonin (sCT) to young rats receiving an anabolic PTH regimen. Co-administration of sCT significantly blunted the anabolic effect of PTH as measured by peripheral quantitative computer tomography (pQCT) and histomorphometry in the femur and tibia, respectively. To determine gene targets of sCT, we carried out quantitative real time PCR and microarray analysis of metaphyseal samples 1.5, 4 and 6.5h after administration of a single injection of PTH, sCT or PTH+sCT. Known targets of PTH action, IL-6, ephrinB2 and RANKL, were not modified by co-administration with sCT. Surprisingly, at all time points, we noted a significant upregulation of sclerostin mRNA by sCT treatment, as well as down-regulation of two other osteocyte gene products, MEPE and DMP1. Immunohistochemistry confirmed that sCT administration increased the percentage of osteocytes expressing sclerostin, suggesting a mechanism by which sCT reduced the anabolic effect of PTH. Neither mRNA for CT receptor (Calcr) nor labeled CT binding could be detected in sclerostin-enriched cells differentiated from primary calvarial osteoblasts. In contrast, osteocytes freshly isolated from calvariae expressed a high level of Calcr mRNA. Furthermore immunohistochemistry revealed co-localization of CT receptor (CTR) and sclerostin in some osteocytes in calvarial sections. Taken together these data indicate that co-treatment with sCT can blunt the anabolic effect of PTH and this may involve direct stimulation of sclerostin production by osteocytes. These data directly implicate calcitonin as a negative regulator of bone formation through a previously unsuspected mechanism.

Ramping up the Spallation Neutron Source beam power with the H- source using 0 mg Cs/day

This paper describes the ramp up of the beam power for the Spallation Neutron Source by ramping up the pulse length, the repetition rate, and the beam current emerging from the H(-) source. Starting out with low repetition rates (< or = 10 Hz) and short pulse lengths (< or = 0.2 ms), the H(-) source and low-energy beam transport delivered from Lawrence Berkeley National Laboratory exceeded the requirements with almost perfect availability. This paper discusses the modifications that were required to exceed 0.2 ms pulse length and 0.2% duty factor with acceptable availability and performance. Currently, the source is supporting neutron production at 1 MW with 38 mA linac beam current at 60 Hz and 0.9 ms pulse length. The pulse length will be increased to approximately 1.1 ms to meet the requirements for neutron production with a power between 1 and 1.4 MW. A medium-energy beam transport (MEBT) beam current of 46 mA with a 5.4% duty factor has been demonstrated for 32 h. A 56 mA MEBT beam current with a 4.1% duty factor has been demonstrated for 20 min at the conclusion of a 12-day production run. This is close to the 59 mA needed for 3 MW neutron productions. Also notable is the Cs(2)CrO(4) cesium system, which dispenses approximately 10 mg of Cs during the startup of the ion source, sufficient for producing the required 38 mA for 4 weeks without significant degradation.

The continued development of the Spallation Neutron Source external antenna H- ion source

The U.S. Spallation Neutron Source (SNS) is an accelerator-based, pulsed neutron-scattering facility, currently in the process of ramping up neutron production. In order to ensure that the SNS will meet its operational commitments as well as provide for future facility upgrades with high reliability, we are developing a rf-driven, H(-) ion source based on a water-cooled, ceramic aluminum nitride (AlN) plasma chamber. To date, early versions of this source have delivered up to 42 mA to the SNS front end and unanalyzed beam currents up to approximately 100 mA (60 Hz, 1 ms) to the ion source test stand. This source was operated on the SNS accelerator from February to April 2009 and produced approximately 35 mA (beam current required by the ramp up plan) with availability of approximately 97%. During this run several ion source failures identified reliability issues, which must be addressed before the source re-enters production: plasma ignition, antenna lifetime, magnet cooling, and cooling jacket integrity. This report discusses these issues, details proposed engineering solutions, and notes progress to date.

Control system for the Spallation Neutron Source H- source test facility Allison scanner

Spallation Neutron Source is currently in progress of a multiyear plan to ramp ion beam power to the initial design power of 1.4 MW. Key to reaching this goal is understanding and improving the operation of the H(-) ion source. An Allison scanner was installed on the ion source in the test facility to support this improvement. This paper will discuss the hardware and the software control system of the installed Allison scanner. The hardware for the system consists of several parts. The heart of the system is the scanner head, complete with associated bias plates, slits, and signal detector. There are two analog controlled high voltage power supplies to bias the plates in the head, and a motor with associated controller to position the head in the beam. A multifunction data acquisition card reads the signals from the signal detector, as well as supplies the analog voltage control for the power supplies. To synchronize data acquisition with the source, the same timing signal that is used to trigger the source itself is used to trigger data acquisition. Finally, there is an industrial personal computer to control the rest of the hardware. Control software was developed using National Instruments LABVIEW, and consists of two parts: a data acquisition program to control the hardware and a stand alone application for offline user data analysis.

Treatment guided by ERCC1, RRM1, and BRCA1 protein expression in patients with advanced-stage NSCLC

e19094

Purpose: We investigated whether Treatment Guided by ERCC1,RRM1 and BRCA1 protein expression levels could improve clinical outcomes in Patients With Advanced-Stage NSCLC. Experimental Design: Eligibility: Main inclusion criteria: Stage IV or stage IIIB NSCLC; Eastern Cooperative Oncology Group(ECOG) performance status (PS) 0–1; Measurable disease; Adequate bone marrow, kidney, liver function. Main exclusion criteria: previous NSCLC therapy; Central nervous system metastasis; Requiring immediate intervention or Untreated with radiation within 28 days of study regimen initiation. Previously untreated patients with Stage IV or stage IIIB NSCLC(N=180): Standard chemotherapy group(N=60): Cisplatin 75mg/m2 Day1+Vinorelbine 25mg/m2 Days 1,8 every 28 days; Individualized chemotherapy group (N=120) (ERCC1,RRM1 and BRCA1 protein expression assayed with IHC); Low ERCC1 protein expression subgroup: Cisplatin 75mg/m2 Day1+Vinorelbine 25mg/m2 Days 1,8 every 28 days; High ERCC1 protein subgroup: Vinorelbine 25mg/m2 Days 1,8+Gemcitabine 1250mg/m2 Days 1,8 every 28 days. Description of Current Analysis: ERCC1,RRM1 and BRCA1 protein expression assayed with IHC; Assigned treatment based on ERCC1 protein expression; Primary endpoint: overall response rate; Secondary endpoints: Overall survival (OS), Progression-free survival (PFS). Enrollment progress (As of time Dec-31–2008): See Table .

[Table: see text]

No significant financial relationships to disclose.

Effect of zoledronic acid combined with cisplatin and paclitaxel on inhibition of non-small cell lung cancer cell lines

e19095

Backgrounds: Recent studies reported that zoledronic acid, a biphosphonate with proposed apoptotic activity, could cause a direct antitumor effect. Our prior study [J Clin Oncol 26: 2008 (May 20 suppl; abstr 19116)] reported that Zoledronic acid combined with Cisplatin shows significantly synergistic antitumor effects on lung cancer cell line A549 and subcutaneous implanted tumor on nude mice. Investigate whether zoledronic acid, augmented the cytotoxicity of cisplatin and/or paclitaxel in A549 lung cancer cell line. Methods: This cell line was subjected to different concentrations of the above chemotherapeutic agents and zoledronic acid. Cytotoxicity was assessed by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrasodium bromide) assay. Flow cytometry was used to examine cell cycle,cell apoptosis rate. Results: Zoledronic acid in in 50 micromolar (mM) concentration augmented the cytotoxicity by cisplatin in 10μmol/L and paclitaxel in 5μmol/L. Zoledronic acid could inhibit the proliferation of lung cancer cells in vitro,which was associated with arresting of G1 phase and inducing apoptosis by a time-dependent and dose-dependentmanner. The apoptosis rate of cell increased after zoledronic acid combined with cisplatin and/or paclitaxel. Conclusions: Zoledronic acid can induce apoptosis and block cell cycle of lung cancer cells. Zoledronic acid has also shown synergistic antitumor effects when combined with cisplatin and/or paclitaxel. The clinical potential of this finding should be further studied.

No significant financial relationships to disclose.

Evaluation of clinically selected patients (pts) with advanced non-small cell lung cancer (NSCLC) recruited in China in a phase III, randomized, open-label, first-line study in Asia of gefitinib (G) versus carboplatin/paclitaxel (C/P) (IPASS)

8041^

Background: The IRESSA Pan Asia Study (IPASS) demonstrated superiority of G vs C/P for progression-free survival (PFS) in 1,217 chemonaïve, never/light ex-smokers with WHO PS 0–2, adenocarcinoma histology and stage IIIB/IV NSCLC. PFS favored C/P initially then G, likely driven by different outcomes according to EGFR mutation (M) status. Planned analyses of pts recruited in China are reported. Methods: 372 pts in China (31% of overall population) were randomized to G 250 mg/day (n=184) or C (AUC 5 or 6)/P (200 mg/m2) (n=188). Primary objective was to assess PFS in ITT population; a treatment by country interaction test (China vs other) was performed. Secondary endpoints were overall survival (OS), objective response rate (ORR, RECIST), QoL (FACT-L, TOI), symptom improvement (LCS) and tolerability. Results: PFS results for pts in China did not significantly differ from other pts (interaction test p=0.4265). G demonstrated numerically longer PFS vs C/P; effect was not constant over time, favoring C/P initially then G. Preliminary OS (28% maturity; follow-up ongoing) was similar for G and C/P. ORR was significantly higher with G (45%) than C/P (30%). QoL improvement rates were higher with G than C/P (FACT-L 44 vs 34%; TOI 45 vs 25%); symptom improvement rates were similar (LCS 48 vs 42%). G had a more favorable tolerability profile than C/P. Conclusions: For pts in China, efficacy and tolerability data were generally consistent with the overall population. G demonstrated improved efficacy (PFS and ORR), similar OS, higher QoL and similar symptom improvement rates and more favorable tolerability profile compared with C/P in chemonaïve, never/light ex-smokers with advanced NSCLC and adenocarcinoma histology. In IPASS, EGFR mutation status appeared to be a strong predictive biomarker for G efficacy compared with C/P.

[Table: see text]

[Table: see text]

ASCO Conflict of Interest Policy and Exceptions

In compliance with the guidelines established by the ASCO Conflict of Interest Policy (J Clin Oncol. 2006 Jan 20;24[3]:519–521) and the Accreditation Council for Continuing Medical Education (ACCME), ASCO strives to promote balance, independence, objectivity, and scientific rigor through disclosure of financial and other interests, and identification and management of potential conflicts. According to the ASCO Conflict of Interest Policy, the following financial and other relationships must be disclosed: employment or leadership position, consultant or advisory role, stock ownership, honoraria, research funding, expert testimony, and other remuneration (J Clin Oncol. 2006 Jan 20;24[3]:520). The ASCO Conflict of Interest Policy disclosure requirements apply to all authors who submit abstracts to the Annual Meeting.

For clinical trials that began accrual on or after April 29, 2004, ASCO's Policy places some restrictions on the financial relationships of principal investigators (J Clin Oncol. 2006 Jan 20;24[3]:521). If a principal investigator holds any restricted relationships, his or her abstract will be ineligible for placement in the 2009 Annual Meeting unless the ASCO Ethics Committee grants an exception. Among the circumstances that might justify an exception are that the principal investigator (1) is a widely acknowledged expert in a particular therapeutic area; (2) is the inventor of a unique technology or treatment being evaluated in the clinical trial; or (3) is involved in international clinical oncology research and has acted consistently with recognized international standards of ethics in the conduct of clinical research. NIH-sponsored trials are exempt from the Policy restrictions. Abstracts for which authors requested and have been granted an exception in accordance with ASCO's Policy are designated with a caret symbol (^) in the Annual Meeting Proceedings.

For more information about the ASCO Conflict of Interest Policy and the exceptions process, please visit www.asco.org/conflictofinterest .

Expression of Estrogen Sulfotransferase 1E1 and Steroid Sulfatase in Breast Cancer: A Immunohistochemical Study

It is known that the steroid sulfatase (STS) and the estrogen sulfotransferase (EST1E1) are commonly expressed in human breast carcinomas. STS and EST1E1 combined action could maintain the equilibrium between sulfated (inactive) and unconjugated (active) estrogens, which might have effects on development of hormone dependent breast cancer.

We studied the expression of the STS and EST1E1 in 88 breast carcinomas and 57 adjacent non-malignant tissues by immunohistochemistry. The results were correlated with the tumor expression of estrogen receptor α (ER-α) and β (ER-β), progesterone receptor A (PR-A) and B (PR-B) and the proliferation marker CDC47, the tumoral type and stage and the age at surgery.

STS expression was higher in carcinoma specimens than in adjacent normal tissues, although not to a significant level (p = 0.064) and it was positively associated with CDC47 expression (p < 0.05). These observations support the hypothesis that STS is overexpressed in breast cancer and associated with a worse prognosis.

EST1E1 was observed for the first time in the nuclei of epithelial and tumoral cells. Tumor expression of EST1E1 was positively correlated with ER-β (p < 0.01) and PR-B (p < 0.05), two steroid receptors already associated with an improve prognosis for breast cancer.

Controlling the STS overexpression in carcinomas could be a way to inhibit cancer growth. The significance of the association between EST1E1 and ER-β or PR-B should be further studied since these two receptors are transcription activators and may regulate the expression of protective enzymes like EST1E1.

Evaluation of response to neoadjuvant chemotherapy in primary breast cancer using PET

Abstract #4019

Purpose&#x2028; To estimate the usefulness of PET scan to assess the response of neoadjuvant chemotherapy, PET scan results were compared with conventional imaging modalities(US and MRI).&#x2028; Patients and Methods&#x2028; Fourty-one patients undergoing neoadjuvant chemotherapy between December 2004 and March 2008 were included. PET scan was performed before and after chemotherapy. Pathologic results were classified into two groups; pathological complete response(pCR) and non-pCR. Clinical responses were assessed with the results of imaging modalities such as post-chemotherapy size or pSUV(postTx), size difference between treatment(delta) and reduction rate(RR) of size or pSUV, and they are compared with postoperative pathologic results.&#x2028; Results&#x2028; 7 out of 41 patients (17.1%) had pCR. The results of US shows that postTx size (1.7±1.5cm) of pCR was not dfferent from those of non-pCR (3.6±3.0cm), and the delta (3.1±1.9cm) and RR (67.7±29.1%) of pCR were higher than those of non-pCR (1.3±1.3cm, 31.0±25.4%), respectively. As a result of MRI, postTx size, delta, RR of pCR was differ from those of non-pCR (1.0±1.7cm vs 2.8±1.7cm p&lt;0.05; 4.5±1.0cm vs 2.3±1.8cm, p&lt;0.05; 88.0±20.8% vs 44.6±24.7%, p&lt;0.01). In PET scan, only postTx pSUV of pCR was differ from that of non-pCR (1.4±1.3 vs 5.3±8.3cm, p&lt;0.05). As a result of receiver operating characteristic curve analyses for the prediction of pathological response of breast cancer, area under curve values (95% confidence interval) of US, MRI, PET for delta were 0.83(0.69∼0.98), 0.91(0.80∼1.01), 0.62(0.38∼0.86), and those of RR were 0.80(0.60∼0.99), 0.90(0.77∼1.02), 0.72(0.47∼0.96), respectively&#x2028; Conclusions&#x2028; We suggest that MRI is useful method to evaluate the response of neoadjuvant chemotherapy. Although PET scan shows less effective for evaluating the response of chemotherapy than MRI, PET scan with the ability to detect the distant metastatic lesions may be helpful to decide the proper management plans for advanced breast cancer.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4019.

Effects of Chinese Herb Danshen-Dahuang on Hippocampal Gene Expression of APP and PS1 in Rats with Alzheimer Disease

Aims:

To investigate the effect of Chinese herb Danshen-Dahuang on learning and memory ability in rats with Alzheimer disease (AD) induced by D-galactose and AlCl3 and its possible mechanisms.

Methods:

The AD model was produced by injecting D-galactose and AlCl3 intraperitoneally for 90 days. Since the 20th day of D-galactose and AlCl3 intraperitoneal injection, the rats in Danshen-Dahuang group had been treated with Danshen-Dahuang extraction by intragastric administration for 70 days. Subsequently,learning and memory ability of the mice was evaluated by Morris water maze and hippocampal gene expression of APP, PS1 was tested by reverse transcription polymerase chain reaction (RT-PCR).

Results:

Rats intragastric administration with Danshen-Dahuang, mice had shorter latency (P< 0.05) and less error times (P< 0.05) in water maze test compared with those in AD model group. At the same time, Danshen-Dahuang down regulated the expression of APP, PS1 mRNA (P< 0.05) in hippocampus.

Conclusions:

Danshen-Dahuang improves the learning and memory ability of AD rats, its mechanism may be related to the downregulated expression of APP, PS1 mRNA.

A Study on Personal Characteristics of the Freshman and Graduates of in Five Different Universities of Shanxi Province of China

Aims:

To study on Personal Characteristics of the freshman and graduates in five different universities.

Methods:

The 1022 freshman and 956 graduates from five different universities were tested with the Eysenck Personality Questiornaire (EPQ). They came from one was general university, two technological universities, one is medical university, one is agricultural university.

Results:

Distribution of freshman and graduates personal characteristics in various sexes and universities is different. There are 19% and 12% of freshman with some psychological problem were P type and N type respectively according to neuroticism scale of EPQ, 64% of that were unstable temperament; 31% of the freshman who were unstable temperament and 25% were mental health status was extroversion disposition. But in graduates are 42% and 34% ( P type and N type) respectively according to neuroticism scale of EPQ. Unstable temperament is 58% and mental health status was extroversion disposition is 39%.

Conclusion:

The freshman and graduates psychological health of Shanxi Province of China is poor and should be paid more attention. the psychological state is related to different universities. the freshman and graduates are associated with personal characteristics, unstable professions, emotional trouble and passive attitude to the value and so on.

Expression of 17beta-hydroxysteroid dehydrogenase type 2 and type 5 in breast cancer and adjacent non-malignant tissue: a correlation to clinicopathological parameters

Estrogens play an important role in the development and progression of breast cancer. 17beta-Hydroxysteroid dehydrogenase (17beta-HSD) type 2 and type 5 are involved in sex steroid metabolism. 17beta-HSD type 2 converts estradiol to estrone while 17beta-HSD type 5 converts androstenedione to testosterone. Using immunocytochemistry, we have studied the expression of 17beta-HSD type 2 and type 5 in 50 specimens of breast carcinoma and adjacent non-malignant tissues. The results were correlated with the estrogen receptor alpha (ERalpha) and beta (ERbeta), progesterone receptor A (PRA) and B (PRB), androgen receptor and CDC47 and with the tumor stage, tumor size, nodal status and menopausal status. 17beta-HSD type 2 was expressed in 20% and 17beta-HSD type 5 in 56% of breast cancer specimens. In adjacent normal tissues, both enzymes were highly expressed in almost all the patients. No significant association could be found between the expression of 17beta-HSD type 2 and 17beta-HSD type 5 and between the expression of each enzyme and the clinicopathological parameters studied. The decrease in 17beta-HSD type 2 and 17beta-HSD type 5 expressions in breast cancer may play a predominant role in the development and/or progression of the cancer by modifying the intratumoral levels of estrogens and androgens.

Efficient association study design via power-optimized tag SNP selection

Discovering statistical correlation between causal genetic variation and clinical traits through association studies is an important method for identifying the genetic basis of human diseases. Since fully resequencing a cohort is prohibitively costly, genetic association studies take advantage of local correlation structure (or linkage disequilibrium) between single nucleotide polymorphisms (SNPs) by selecting a subset of SNPs to be genotyped (tag SNPs). While many current association studies are performed using commercially available high-throughput genotyping products that define a set of tag SNPs, choosing tag SNPs remains an important problem for both custom follow-up studies as well as designing the high-throughput genotyping products themselves. The most widely used tag SNP selection method optimizes the correlation between SNPs (r(2)). However, tag SNPs chosen based on an r(2) criterion do not necessarily maximize the statistical power of an association study. We propose a study design framework that chooses SNPs to maximize power and efficiently measures the power through empirical simulation. Empirical results based on the HapMap data show that our method gains considerable power over a widely used r(2)-based method, or equivalently reduces the number of tag SNPs required to attain the desired power of a study. Our power-optimized 100k whole genome tag set provides equivalent power to the Affymetrix 500k chip for the CEU population. For the design of custom follow-up studies, our method provides up to twice the power increase using the same number of tag SNPs as r(2)-based methods. Our method is publicly available via web server at http://design.cs.ucla.edu.