P4-02-08: Obesity-Induced Aromatase Expression in the Breast Microenvironment Promotes Estrogen Receptor Activity Independent of Circulating Estradiol Levels

Epidemiological studies indicate that obesity increases the risk of postmenopausal breast cancer by approximately 50%. In the past, researchers have hypothesized that elevated estrogen synthesis by the peripheral adipose tissue may be the principal mediator of breast tumorigenesis in this population, which primarily develops estrogen receptor alpha (ERα) positive breast cancer. However, obesity is also accompanied by an elevation in growth factor and cytokine signaling, and these pathways have been linked to tumorigenesis. In addition, certain growth factor and cytokine family members can promote aromatase expression in both the epithelial and stromal tumor compartments. Consequently, we hypothesized that obesity increases the risk of postmenopausal breast cancer via elevated aromatase expression and/or activity in the local mammary tissue.

To test our hypothesis, we investigated how ERa activity in mammary epithelial cells was influenced by adipose stromal cells (ASC) cultured under obesity-associated conditions, including high cell density and exposure to elevated levels of circulating growth factors and cytokines. For the latter condition, sera was obtained from postmenopausal women, pooled by BMI category (lean: 18.5−24.9; obese: ≥30), and applied to the ASC, which were originally derived from women undergoing reduction mammoplasty. High ASC density was achieved via the protocol previously published by Dr. Li. Preliminary data indicated that both elevated cell density and sera from obese postmenopausal women induces greater aromatase expression in ASC, indicating that multiple factors may be contributing to the increased local aromatase expression seen with obesity. We are currently exploring the signaling pathways responsible for obesity's upregulation of ASC aromatase expression and will present these results at the meeting. Intriguingly, exposure to conditioned media from both the high density and obese sera-exposed ASC enhanced ERa activity in MCF-7 mammary epithelial cells, independent from exogenous estradiol but dependent on the presence of androgens, suggesting an important role for the aromatase enzyme in this observation. To expand on this finding, we plan to investigate the effect of ASC conditioned media on different markers of cancer aggression, including proliferation and survival, and assess the degree to which these effects depend on estradiol. Through further examination of obesity's impact on signaling pathways in both the epithelial and stromal tumor compartments, we ultimately hope to identify more effective chemopreventive and therapeutic regimens for the high-risk obese postmenopausal population.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-02-08.

Analysis of altered proteins related to blast crisis in chronic myeloid leukemia by proteomic study

INTRODUCTION

Chromic myeloid leukemia (CML) blast crisis (BC) and imatinib (IM) resistance is a significant barrier to the effective treatment of the disease.

METHODS

Expression profiles of differential proteins were identified, and new biomarkers or pathways related to BC in CML were screened through proteomic analysis. Total proteins from primary bone marrow cells of CML patients in chronic phase (CP) and BC were separated via two-dimensional (2D) polyacrylamide gel electrophoresis and then analyzed by imagemaster 5.0 software to detect differential protein spots which were already identified by mass spectrometry. Based on the variation of the whole expression profile, some key proteins were picked out for Western blot to confirm the accuracy of proteomics data. Moreover, related signal pathways involving those proteins were investigated.

RESULTS

The result indicated that thirteen protein points between CML-CP and CML-BC were successfully determined. Results from Western blot of RhoA, hnRNPK, ANXA1, PSMB4, and LTA4H were similar to those from 2D polyacrylamide gel electrophoresis. Most of those proteins were involved in the proteosome pathway and the small G-protein pathway.

CONCLUSION

A group of proteins associated with BC can be obtained and the result of this study might provide clues for further research.

First Report of Little cherry virus 2 in Flowering and Sweet Cherry Trees in China

Many viruses infect Prunus spp. and cause diseases on them. During a survey of stone fruit trees in 2008 and 2009, flowering cherry (Prunus serrulata) and sweet cherry (P. avium) trees with foliar chlorosis and reddening, stem deformity, and tree stunting were observed in private orchards in Anning and Fumin counties of Yunnan Province. Some sweet cherry trees with severe symptoms yielded small and few fruits and had to be removed. Leaf samples were collected from 68 flowering cherry and 30 sweet cherry trees, either symptomatic or asymptomatic, from private orchards and community gardens in Kunming and counties Anning, Chenggong, Fumin, Jinning, Ludian and Yiliang. Total nucleic acids were extracted with a CTAB extraction method and tested by reverse transcription (RT)-PCR assay using virus-specific primers. Little cherry virus 2 (LChV-2), Cherry virus A (CVA), Prunus necrotic ringspot virus (PNRSV), and Prune dwarf virus (PDV) were detected and infection rates were 68.4, 16.3, 9.2, and 7.1%, respectively. Infection of LChV-2 was common in all counties except Ludian where the orchards were healthy. Of 68 infected trees, 29 were found to be infected with LChV-2 and CVA, PDV or PNRSV. LChV-2 was detected in this study by RT-PCR using a pair of novel primers, LCV2-1 (5'-TTCAATATGAGCAGTGTTCCTAAC-3') and LCV2-4 (5'-ACTCGTCTTGTGACATACCAGTC-3'), in 59 flowering cherry (87%) and 8 sweet cherry (27%) trees, respectively. The primer pair was designed according to alignment of three available LChV-2 sequences (GenBank Nos. NC_005065, AF416335, and AF333237) to amplify the partial RNA-dependent RNA polymerase gene (ORF1b) of 781 bp. The amplicons of selected samples (Anning26 and Yiliang60) were sequenced directly and sequences of 651 bp (GenBank No. HQ412772) were obtained from both samples. Pairwise comparisons and phylogenetic analysis of the sequences show that the two isolates are identical to one another and share 92 to 96% at the amino acid (aa) sequence level to those of other isolates available in the GenBank database. The sequence data confirm that these isolates are a strain of LChV-2 and genetic variation among different strains is relatively high (2). Biological and serological assays are not available for the LChV-2 detection; therefore, the LChV-2 infections of these trees were further confirmed by RT-PCR using primer pair LCV2-5 (5'-TGTTTGTGTCATGTTGTCGGAGAAG-3') and LCV2-6 (5'-TGAATACCCGAGAACAAGGACTC-3'), which amplified the helicase domain (ORF1a) of ~451 bp. The amplicons from samples Anning26 and Yiliang60 were cloned and sequenced. The 408-bp sequences (excluding primer sequences) were 92 to 98% identical at the aa sequence level to those of other isolates, confirming again their viral origin. LChV-2 (genus Ampelovirus, family Closteroviridae) (4) has been associated with little cherry disease (LChD), a widespread viral disease of sweet and sour cherries (1,3). The virus is transferred between geographic areas mainly by propagated materials. Ornamental and sweet cherries are important crops in China and LChD has the potential to cause significant economic losses. Thus, certified clean stock should be used to establish new orchards. To our knowledge, this is the first report of LChV-2 in cherries in China. References: (1) N. B. Bajet et al. Plant Dis. 92:234, 2008. (2) W. Jelkmann et al. Acta Hortic. 781:321, 2008. (3) B. Komorowska and M. Cieslińska, Plant Dis. 92:1366, 2008. (4) M. E. Rott and W. Jelkmann. Arch. Virol. 150:107, 2005.

Association of CD247 with systemic lupus erythematosus in Asian populations

OBJECTIVE

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease with complex genetic inheritance. CD247 (CD3Z, TCRZ) plays a vital role in antigen recognition and signal transduction in antigen-specific immune responses, and is known to be involved in SLE pathogenesis. Weak disease association was reported for genetic variants in this gene in Caucasian studies for SLE, Crohn's disease and systemic sclerosis, but its role as a genetic risk factor was never firmly established.

METHODS

In this study, using a collection of 612 SLE patients and 2193 controls of Chinese ethnicity living in Hong Kong in a genome-wide study, single nucleotide polymorphisms (SNPs) in and around CD247 were identified as being associated with SLE. The two most significant SNPs in this locus were selected for further replication using TaqMan genotyping assay in 3339 Asian patients from Hong Kong, Mainland China, and Thailand, as well as 4737 ethnically and geographically matched controls.

RESULTS

The association of CD247 with SLE in Asian populations was confirmed (rs704853: odds ratio [OR] = 0. 81, p = 2.47 × 10(-7); rs858543: OR = 1.10, p = 0.0048). Patient-only analysis suggested that rs704853 is also linked to oral ulcers, hematologic disorders and anti-double-stranded DNA (dsDNA) antibody production.

CONCLUSION

A significant association between variants in CD247 and SLE was demonstrated in Asian populations. Understanding the involvement of CD247 in SLE may shed new light on disease mechanisms and development of new treatment paradigms.

SmgGDS splice variants: Potential novel targets for breast cancer therapeutics

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Background: Breast cancer malignancy is promoted by the small GTPases K-Ras, Rap1, RhoA, and Rac1. We recently reported that the activity of these GTPases is regulated by two splice variants of SmgGDS, named SmgGDS-558 and SmgGDS-607. SmgGDS is overexpressed in lung and prostate cancer, but its role in breast cancer is unknown. Here we examine whether SmgGDS splice variants are expressed in breast cancer and promote breast cancer malignancy.

Methods: Immunohistochemical staining for SmgGDS was performed on archival human breast tumors (N=183) and normal breast tissue (N=22). Immunoblotting was used to detect SmgGDS splice variants in human breast cancer cell lines. siRNAs that silence different SmgGDS splice variants were used to examine the effects of SmgGDS knockdown on breast cancer cell spreading, cell proliferation via [3H]thymidine uptake, anchorage-independent cell growth using soft agar colony assays, and NF-kB activation using luciferase reporter assays.

Results: SmgGDS expression was detected in >65% of DCIS and invasive lobular and ductal carcinoma, and in 100% of metastatic tumors, but was detected in only 18% of normal breast tissue specimens (p<0.01). All tested cell lines expressed both SmgGDS splice variants. Silencing SmgGDS-558 or SmgGDS-607 with siRNA significantly diminished cell proliferation (100±2.0 vs. 11.3±1.0 vs. 50.5±2.2, p<0.05) in MCF-7 cells, with similar results in MDA-MB-231 and T47D cells. MCF-7 soft agar colony formation was significantly decreased 71% and 49% when SmgGDS-558 or SmgGDS-607 was silenced. MCF-7 cell spreading was promoted by silencing SmgGDS-558, but not SmgGDS-607. NF-kB activation was also decreased by 30% in resting and TNF-α-treated MCF-7 and MDA-MB-231 cells by silencing either splice variant.

Conclusions: SmgGDS is disproportionally expressed in human breast cancers. Reduction of SmgGDS-558 and SmgGDS-607 levels dramatically reduced breast cancer cell proliferation, soft agar colony formation, and NF-kB activation. Our results indicate that SmgGDS splice variants regulate breast cancer malignancy, most likely through their regulation of small GTPases. This study identifies SmgGDS splice variants as novel therapeutic targets in breast cancer.

Targeted gene silencing of TLR4 using liposomal nanoparticles for preventing liver ischemia reperfusion injury

RNAi-based therapy is a promising strategy for the prevention of ischemia-reperfusion injury (IRI). However, systemic administration of small interfering RNA (siRNA) may cause globally nonspecific targeting of all tissues, which impedes clinical use. Here we report a hepatocyte-specific delivery system for the treatment of liver IRI, using galactose-conjugated liposome nanoparticles (Gal-LipoNP). Heptocyte-specific targeting was validated by selective in vivo delivery as observed by increased Gal-LipoNP accumulation and gene silencing in the liver. Gal-LipoNP TLR4 siRNA treatment resulted in a significant decrease of serum alanine transferase (ALT) and aspartate transaminase (AST) in a hepatic IRI model. Histopathology displayed an overall reduction of the injury area in the Gal-LipoNP TLR4 siRNA treated mice. Additionally, neutrophil accumulation and lipid peroxidase-mediated tissue injury, detected by MPO, MDA and ROS respectively, were attenuated after Gal-LipoNP TLR4 siRNA treatment. Moreover, therapeutic effects of Gal-LipoNP TLR4 siRNA were associated with suppression of the inflammatory cytokines IL-1 and TNF-α. Taken together, this study is the first demonstration of liver IRI treatment using liver-specific siRNA delivery.

Curcumin improves insulin resistance in skeletal muscle of rats

BACKGROUND AND AIMS

Curcumin has been reported to lower plasma lipids and glucose in diabetic rats, and to decrease body weight in obese rats, which may partly be due to increased fatty acid oxidation and utilization in skeletal muscle.

METHODS AND RESULTS

Diabetic rats induced by high-fat diet plus streptozotocin (STZ, 30 mg/kg BW) were fed a diet containing 50, 150, or 250 mg/kg BW curcumin for 7 wk. Curcumin dose-dependently decreased plasma lipids and glucose and the dose 150 mg/kg BW appeared to be adequate to produce a significant effect. Curcumin supplementation reduced glucose and insulin tolerance measured as areas under the curve. L6 myotubes were treated with palmitate (0.25 mmol/L) in the presence of different levels of curcumin for 24 h in our in vitro experiment. Curcumin at 10 μmol/L was adequate to cause a significant increase in 2-deoxy-[(3)H]d-glucose uptake by L6 myotubes. Curcumin up-regulated expression of phosphorylated AMP-activated protein kinase (AMPK), CD36, and carnitine palmitoyl transferase 1, but down-regulated expression of pyruvate dehydrogenase 4 and phosphorylated glycogen synthase (GS) in both in vivo and in vitro studies. Moreover, curcumin increased phosphorylated acetyl COA carboxylase in L6 myotubes. The effects of curcumin on these enzymes except for GS were suppressed by AMPK inhibitor, Compound C. LKB1, an upstream kinase of AMPK, was activated by curcumin and inhibited by radicicol, an LKB1 destabilizer.

CONCLUSION

Curcumin improves muscular insulin resistance by increasing oxidation of fatty acid and glucose, which is, at least in part, mediated through LKB1-AMPK pathway.

Impulse control disorders in Chinese Parkinson's disease patients: the effect of ergot derived dopamine agonist

OBJECTIVE

We studied the prevalence and related risk factors of impulse control disorders in Chinese Parkinson's disease patients.

METHOD

We screened all non-demented Parkinson's disease patients attending our Parkinson's disease clinic from August 2009 to March 2010. The clinical characteristics of patients with impulse control disorders and those without were compared.

RESULTS

Of the 213 PD subjects screened, 15 (7.0%) with impulse control disorders were identified. Fourteen of these subjects were on both a dopamine agonist and Levodopa, and one was on Levodopa alone. Of the fourteen subjects on both a dopamine agonist and Levodopa, eleven were on bromocriptine and Levodopa; 10.5% of the subjects exposed to bromocriptine had impulse control disorder. Upon multivariate analysis, dose of dopamine agonist used, young age at onset of Parkinson's disease and a history of anxiety or depression were independent predictors for developing impulse control disorders.

CONCLUSIONS

7% of our Chinese PD subjects had impulse control disorders. When young Parkinson's disease patients with a history of anxiety or depression are treated with high dose of DA, they are at risk of developing impulse control disorders.

A random comparative study of terbinafine versus griseofulvin in patients with tinea capitis in Western China

OBJECTIVE

To compare the efficacy and safety of terbinafine with griseofulvin in the treatment of tinea capitis in Western China.

METHODS

Children (2-14 years of age) with clinically diagnosed and potassium hydroxide microscopy-confirmed tinea capitis were randomized into three groups: group GRI4 received 4 weeks of griseofulvin; group TBF2 received 2 weeks of terbinafine; and Group TBF4 received 4 weeks of terbinafine. Clinical and mycological evaluations were done in 0, 2, 4, and 8 weeks and 1 year after therapy started. The isolated pathogenic fungi were evaluated for in vitro susceptibility by detecting the minimal inhibitory concentration (MIC) against terbinafine, griseofulvin, itraconazole, and ketoconazole.

RESULTS

The clinical effectiveness rate of GRI4, TBF2, and TBF4 were 100% (95% CI-confidence interval: 82-100%), 96.3% (95% CI: 81-100%), and 100%(95% CI: 85-100%), respectively, at week 8 and 100% after 1 year for the 3 groups; clinical cure rates were 84.2%(95% CI: 77-99%), 85.2%(95% CI: 71-98%), and 78.3%(95% CI: 61-95%), respectively, at week 8 and 100% after 1 year for all agents; mycological cure rates were 100%(95% CI: 74-100%), 95.0%(95% CI: 74-100%), and 94.1%(95% CI: 50-93%) at week 8 and 100% after 1 year for the 3 groups. In vitro, all patient-derived cultures were sensitive to the four antifungal agents.

CONCLUSION

Data from the clinical trial and in vitro antifungal activity indicated that terbinafine is efficacious and well tolerated in the treatment for Trichophyton infections (T. violaceum; Arthroderma vanbreuseghemii; and T. tonsurans) of the scalp, i.e., a 2- to 4-week course of terbinafine is as effective as a 4-week course of griseofulvin; in fact, a 2-week course of terbinafine is sufficient. Terbinafine is an effective alternative to griseofulvin against tinea capitis of Trichophyton infections.