Stable knockdown of clusterin by vectorbased RNA interference in a human breast cancer cell line inhibits tumour cell invasion and metastasis

OBJECTIVE

Overexpression of the clusterin (CLU) gene occurs in breast cancer and is associated with lymph node metastasis. The present study explored the effect of CLU silencing on invasion and metastasis, and the relationship between CLU expression and the extracellular signal-regulated kinase (ERK) / matrix metalloproteinase-9 (MMP) signalling pathway in human breast cancer cells.

METHODS

A pcDNA3.1-based RNA interference approach was used to knockdown the CLU gene in MDA-231 cells (MDA-231-CLUi); control MDA-231 cells were transfected with an empty vector (MDA-231-Vec). Reverse transcription-polymerase chain reaction was used to assess CLU and MMP-9 mRNA levels, and Western blotting was used to analyse CLU, MMP-9 and ERK protein levels. Metastatic potential was evaluated using in vitro and in vivo models of invasion and metastasis.

RESULTS

Compared with MDA-231-Vec cells, the MDA-231-CLUi cells demonstrated reduced migration and invasion in vitro and decreased metastatic potential in vivo. Reintroduction and reexpression of the CLU gene into the MDA-231-CLUi cells restored the invasive phenotype. MMP-9 mRNA and protein levels were reduced in MDA-231-CLUi cells, and there was a correlation between activated ERK and CLU and MMP-9 protein levels.

CONCLUSION

CLU may regulate the aggressive behaviour of human breast cancer cells through modulation of ERK signalling and MMP9 expression.

Molecular Characterization of Fusarium Head Blight Pathogens Sampled from a Naturally Infected Disease Nursery Used for Wheat Breeding Programs in China

Fusarium head blight (FHB) is an important disease of wheat and barley worldwide. The disease is primarily caused by members of the Fusarium graminearum species complex, consisting of at least 14 phylogenetically distinct species. To determine the population structure of the FHB pathogens in a naturally infected disease nursery located at Jianyang, Fujian province, China, 160 isolates of the F. graminearum complex were recovered from symptomatic wheat spike samples collected in two consecutive years (2008 and 2009) and characterized using species- and chemotype-specific polymerase chain reaction as well as variable number tandem repeat (VNTR) markers. All isolates analyzed were identified as F. asiaticum except for one isolate, which was identified as F. avenaceum. Among the 159 F. asiaticum isolates, 126 (79%) isolates were of the nivalenol (NIV) type while 29 (18%) isolates were of the 15-acetyl deoxynivalenol type and only 4 (3%) isolates were of the 3-acetyl deoxynivalenol type. The 10 VNTR markers revealed 124 distinct haplotypes and 76 polymorphic alleles across the whole population. The two subpopulations (FA-08 and FA-09) grouped based on the year of collection exhibited low genetic differentiation (F_st = 0.032) and high gene flow (N_m = 15.13). However, a significant genetic differentiation was found within the NIV-type isolates as revealed by the Structure software. The pairwise linkage disequilibrium tests did not support the hypothesis of random mating in the population because half (48.8%) of the locus pairs showed a linkage disequilibrium (P > 0.05). Our results suggest that FHB in this nursery was caused by a genetically homogenous and non-random mating population of F. asiaticum in 2008 and 2009, which consisted of all three trichothecene types with various levels of aggressiveness.

Virulence profile and genetic structure of a North Dakota population of Pyrenophora teres f. teres, the causal agent of net form net blotch of barley

A Pyrenophora teres f. teres population in North Dakota was analyzed for virulence variation and genetic diversity using 75 monospore isolates that were collected across a 4-year period (2004 to 2007) from two North Dakota State University agricultural experiment stations at Fargo and Langdon. Pathogenicity tests by inoculation onto 22 barley differential lines at seedling stage revealed 49 pathotypes, indicating a wide range of pathogenic diversity. Two-way analysis of variance of disease ratings revealed a significant difference in the virulence among isolates and in the resistance among barley lines, as well as in the interactions between the two. 'CI5791', 'Algerian', and 'Heartland' were three barley lines showing a high level of seedling resistance to all North Dakota isolates tested; however, many previously reported resistance genes have been overcome. Forty multilocus genotypes were identified from this set of isolates by genotyping at 13 simple-sequence repeat loci. High percentages of clonal cultures were detected in the samplings from 2005 and 2007 in Fargo and 2005 in Langdon. Using a clone-corrected sample set, the mean gene diversity (h) was estimated to be 0.58, approximately the same for both locations. The calculated Wright's F(ST) value is small (0.11) but was significantly >0, indicating a significant differentiation between the Fargo and Langdon populations. In the gametic disequilibrium test, only 3 of 78 possible pairwise comparisons over all isolates showed significant (P < 0.05) nonrandom association, suggesting a random mating mode. Our results suggest that the populations from the two locations are derived from a common source and undergo frequent recombination. This research provides important information for barley breeders regarding development and deployment of cultivars with resistance to net form net blotch in this region.

P5-13-14: Drug-Metabolizing Enzyme Polymorphisms and Clinical Outcome of Anthracycline-Based Chemotherapy in Chinese Han Breast Cancer Patients

Background

Anthracycline is one of the most effective drugs in the treatment of breast cancer and many of our most effective treatment regimens include anthracycline. Its efficacy can be influenced by cellular detoxification mechanisms involving drug metabolism and transport pathways. This study aimed to assess whether the functional polymorphisms in drug-metabolizing enzymes (MnSOD, CAT and GSTs) and transporter MDR1 may predict anthracycline treatment-related outcomes in Chinese Han breast cancer patients.

Material and methods: Genotyping was performed by allele-specific oligonucleotide ligation reaction (MnSOD T47C, CAT C-262T, GSTP1 A313G), multiplex PCR (GSTM1 null, GSTT1 null), and PCR-RFLP (MDR1 C3435T, G2677T/A and C1236T). Based on 153 evaluable patients received anthracycline-based neoadjuvant chemotherapy for breast cancer, the associations of these genotypes or their haplotypes with clinical response and recurrence-free survival (RFS) were analyzed.

Results: Of the 153 cases, the patients with GSTP1 313AA genotype had inferior response rates relative to those with AG or GG genotype (58.4% vs 77.8% or 100.0%; χ2=4.922, P=0.027). Moreover, the response rate of the combination of GSTP1 AA with both GSTT1 present and GSTM1 present was 44%, which was also lower comparing with the other groups (70.3%; χ2=6.454, P=0.011). A similar result was noticed for MDR1 3435 TT genotype, which had a significantly worse chemotherapy response compared with wild-type C allele carrier (33.3% vs 71.2%; χ2=11.586, P=0.001). Further, the response rate of the patients with 3435T-2677T, 3435T-1236T or 3435T-2677T-1236T haplotypes was lower than that of the patients with the other corresponding haplotypes (P=0.018, 0.011 and 0.019, respectively), too. Of note, the patients with both the adverse genotypes of GSTP1 314AA and MDR 3435TT shown the worst treatment efficacy in all (14.3%;χ2=26.33, P=0.000). Mean follow-up time of the 149 patients (4 patients lost) was 51 months. The recurrence rate in the patients with GSTP1 313AA or/and MDR 3435TT in the first three years was 39.0% (41/105), higher significantly than those with no adverse genotype [15.9% (7/44); OR=0.725, 95%Cl: 0.594−0.885, P=0.006]. Kaplan-Meier survival analysis showed that the patients with no adverse genotype were associated with reduced hazard of relapse (long-rank test, P&lt;0.01), compared to those with 1 or 2 adverse genotypes.

Conclusion: Polymorphisms in GSTs and MDR1 genes may help to predict clinical response and RFS of anthracycline-based chemotherapy in breast cancer, but further validation is required. These results provide support for a polygenic pathway approach for assessing the predictive potential of polymorphisms in treatment outcomes.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-13-14.

Complement inhibition enables renal allograft accommodation and long-term engraftment in presensitized nonhuman primates

Protection against humoral injury mediated by donor-specific antibodies (DSA), also known as accommodation, may allow for long-term allograft survival in presensitized recipients. In the present study, we determined the role of complement in renal allograft accommodation in donor skin-presensitized nonhuman primates under conventional immunosuppression. Donor skin allografts were transplanted to presensitized recipients 14 days prior to renal transplantation. Renal allografts not receiving any immunosuppressive treatment developed accelerated rejection with predominantly humoral injury, which was not prevented using conventional cyclosporine (CsA) triple therapy. Inhibition of complement activation with the Yunnan-cobra venom factor (Y-CVF) successfully prevented accelerated antibody-mediated rejection and resulted in successful accommodation and long-term renal allograft survival in most presensitized recipients. Accommodation in this model was associated with the prevention of the early antibody responses induced against donor antigens by complement inhibition. Some antiapoptotic proteins and complement regulatory proteins, including Bcl-2, CD59, CD46 and clusterin, were upregulated in the surviving renal allografts. These results suggest that the complement inhibition-based strategy may be valuable alternative in future clinical cross-match positive or ABO-incompatible transplantation.

Sequence variation and genetic diversity in the giant panda

About 336-444 bp mitochondrial D-loop region and tRNA gene were sequenced for 40 individuals of the giant panda which were collected from Mabian, Meigu, Yuexi, Baoxing, Pingwu, Qingchuan, Nanping and Baishuijiang, respectively. 9 haplotypes were found in 21 founders. The results showed that the giant panda has low genetic variations, and that there is no notable genetic isolation among geographical populations. The ancestor of the living giant panda population perhaps appeared in the late Pleistocene, and unfortunately, might have suffered bottleneck attacks. Afterwards, its genetic diversity seemed to recover to some extent.

Liposomes containing (-)-gossypol-enriched cottonseed oil suppress Bcl-2 and Bcl-xL expression in breast cancer cells

PURPOSE

We have demonstrated that (-)-gossypol-enriched cottonseed oil [(-)-GPCSO] can down-regulate Bcl-2 expression in MCF-7 and primary cultured human breast cancer epithelial cells (PCHBCECs). However, this agent has not been evaluated in vivo due to its limited solubility. We aimed to develop liposomes containing (-)-GPCSO to suppress Bcl-2/Bcl-xL expression.

METHODS

(-)-GPCSO liposomes were prepared and evaluated for effects on breast cancer cell viability, MDA-MB-231 xenograft tumor growth, cellular Bcl-2 and Bcl-xL mRNA levels, and chemosensitivity to paclitaxel.

RESULTS

(-)-GPCSO liposomes prepared had excellent stability. Cytotoxicity of (-)-GPCSO liposomes was significantly reduced compared to (-)-GPCSO in culture medium. Bcl-2 and Bcl-xL mRNA expression was down-regulated by (-)-GPCSO in culture medium or (-)-GPCSO liposomes in MDA-MB-231 cells. In PCHBCECs, Bcl-2 and Bcl-xL expression were down-regulated by (-)-GPCSO liposomes. (-)-GPCSO in culture medium induced only a mild reduction in Bcl-xL. In the MDA-MB-231 xenograft tumor model, (-)-GPCSO liposomes exhibited tumor-suppressive activity and significantly reduced intratumoral Bcl-2 and Bcl-xL expression. Cytotoxicity of paclitaxel was increased by pretreatment with (-)-GPCSO liposomes in MDA-MB-231 and PCHBCECs.

CONCLUSIONS

Findings suggest that (-)-GPCSO liposomes warrant continued investigation as a chemosensitizer for breast cancers exhibiting Bcl-2-/Bcl-xL-mediated drug resistance.

Zeranol induces cell proliferation and protein disulfide isomerase expression in mammary gland of ACI rat

BACKGROUND

Zeranol is a non-steroidal anabolic growth promoter with potent estrogenic activity that is widely used as a growth promoter in the US beef industry. Consumption of beef derived from Zeranol-implanted cattle may be a risk factor for breast cancer. Protein disulfide isomerase (PDI) has been studied extensively as a key enzyme involving in the formation of the correct pattern of disulfide bonds in newly synthesized proteins. The relationship between PDI expression and cancer development has attracted interest of cancer researchers in recent years.

MATERIALS AND METHODS

We implanted ACI rats with 12 mg Zeranol pellet and harvested the mammary tissues and tumor at day 110 after implantation and investigated the effect of Zeranol-implantation on cell proliferation by histological examination and proliferation in vitro. We also evaluated PDI mRNA expression in primary epithelial cells isolated from normal mammary glands and primary tumor cells from tumor specimens using real-time RT-PCR. To further confirm, we also evaluated the effect of Zeranol on PDI mRNA expression in primary epithelial cells isolated from normal mammary gland of ACI rats.

RESULTS

We observed a palpable mammary tumor in one of three Zeranol-implanted ACI rats at day-110 post Zeranol-implantation. Zeranol-implantation significantly promoted the cell proliferation of primary mammary epithelial and stromal cells isolated from the mammary gland of normal ACI rats. PDI mRNA is over-expressed in primary tumor cells isolated from the tumor specimen and in Zeranol-treated primary cultured epithelial cells from the mammary gland of normal ACI rats.

CONCLUSION

These findings suggest that up-regulated expression of PDI may play a critical role in mammary tumorigenesis and cell proliferation in response to Zeranol. Our findings implicate PDI as a biomarker for mammary tumorigenesis.

Abstract 33: Microarray analysis of zeranol induced gene expression in primary cultured human breast cancer epithelial cells

Zeranol (Z) is a nonsteroidal mycotoxin with potent estrogenic activity. Z is one of six growth promoters approved by the FDA for use in the U.S. beef industry to accelerate weight gain, improve feed efficiency and increase the lean meat-to-fat ratio. Recently, the safety meat products from Z-implanted beef has been questioned on the basis that increased exposure of bioactive Z residues may have adverse health implications. Our previous study showed that serum, meat and meat extracts derived from beef cattle implanted with Z significantly stimulated the proliferation of primary cultured human normal and cancerous breast epithelial cells, primary cultured human breast pre-adipocytes, and human breast cancer cell lines. However, little is known about the mechanisms of Z stimulation on the growth of different types of breast cells. To systematically investigate gene expression patterns in primary cultured human breast cancer epithelial cells (PCHBCECs) after Z treatment, we performed DNA microarray analysis. After PCHBCECs were isolated from breast cancer tissue, they were treated with 30 nM Z or 0.1% DMSO, as a vehicle control, for 48 hr, and then mRNA was isolated and purified for gene expression analysis using the Human Genome U133 Plus 2.0 Array TM (Affymetrix Co. Ltd) in the Microarray Shared Resources at The Ohio State University Comprehensive Cancer Center. DNA microarray data were generated on the basis of the criteria of signal intensity and signal ratio. Our results showed that 10 genes were down-regulated and 25 genes were up-regulated in PCHBCECs treated with 30 nM Z as compared to the controls. Among the genes regulated by Z were, limb-bud and heart (LBH) and annexin-1 (ANXA1) which were decreased 2.27 and 2 fold, respectively and human HMG-CoA synthase 1 (HMGCS1) and methyltransferase like 7A (METTL7A) which were up-regulated to 3.8 and 3.25 fold, respectively compared with the controls. Our preliminary data also showed that Z decreased the expression of several tumor suppressor genes, such as protein tyrosine phosphatase γ (PTPγ), p16, p21, and increased DNMT1 expression in PCHBCECs which suggests epigenetic modification of Z in their promoter regions. Our results indicate that long term consumption of beef products with low level of Z or its metabolites might have adverse health effects on human breast. Further validation of our DNA microarray results is in progress in our laboratory (Supported by NIH R01Grant ES 015212).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 33. doi:10.1158/1538-7445.AM2011-33

Abstract 3956: Differential miR-141 expression in primary cultured human breast cancer epithelium (PCHBCEs) and normal adjacent part epithelium (PCHBNEs) correlates with tumor suppressor protein tyrosine phosphataseγ (PTPγ)

MicroRNAs (miR) have been shown to be extensively involved in tumorigenesis by post-transcriptional inhibition of oncogenes and/or tumor-suppressor genes. The purpose of our study is to investigate the difference in miRNA expression between cancer epithelium and epithelium from normal breast adjacent tissues. The clinical samples were procured from the Tissue Procurement Program at the Ohio State University Comprehensive Cancer Hospital from breast cancer patients who underwent partial or complete mastectomy. The miRNA profiling for one pair of PCHBCEC and PCHBNEC from the same patient was carried out, and the difference of miRNA expression and potential target genes were further verified by realtime qPCR in 7 pairs of clinical samples. The miRNA profiling showed that 24 miRNAs (let-7a, let-7c, let-7f, let-7g, miR-24, miR-28, miR-29a, miR-29c, miR-30a-5p, miR-30d, miR-92, miR-125a, miR-126*, miR-132, miR-135a, miR-135b, miR-137, miR-141, miR-182, miR-200c, miR-339, miR-365, miR-425-5p, miR-391, p&lt;0.05) are statistically up-regulated in cancer while only 1 miRNA (miR-221) is down-regulated. Based on the magnitude of change and predicted target, we selected miR-141 for further validation. Compared with its normal adjacent counterpart, 4 PCHBCECs had lower miR-141 while 2 were up-regulated and 1 unaltered. Further validation on gene expression of the samples confirmed the negative correlation of miR-141 with its putative target PTPγ. Our comparison of PCHBCECs and PCHBNECs under the same genetic background demonstrated a distinct expression of miRNAs. The dysregulation of miR-141 was shown to result in modulation of the potential tumor-suppressor gene PTPγ which might have an impact on the etiological process of tumor lesion and discriminate cancer epithelial cells from their surrounding normal breast epithelial compartments. Our results implicate that miR-141 might serve as molecular biomarker for therapy of human breast cancer patients. (Supported by NIH R01 Grant ES 015212).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3956. doi:10.1158/1538-7445.AM2011-3956

Leptin and zeranol up-regulate cyclin D1 expression in primary cultured normal human breast pre-adipocytes

Adipocytes account for more than 90% of human breast volume and secrete adipocytokines, which play a role in breast cancer development. Among the adipocytokines is leptin, which is secreted mainly by adipocytes and plays a key role in breast cancer development. Leptin expression is up-regulated in both obese and breast cancer patients, and promotes breast cancer cell growth. Exposure to environmental estrogens has also been found to be directly related to the development of breast cancer. Zeranol (Z) is a non-steroidal anabolic growth promoter with estrogenic activity that is widely used in the US beef industry due to its commercial benefits. Gossypol is a natural compound extracted from cottonseed that inhibits breast cancer growth, and is potentially a chemopreventive food component. This study focused on Z and bio-active Z-containing sera (ZS) collected from Z-implanted beef, and evaluated their adverse health risk to humans. We hypothesized that Z increases the risk of breast cancer in obese women. A cell proliferation assay, ELISA analysis, RT-PCR and Western blotting were performed to investigate the interaction of leptin, Z and (-)-gossypol in primary cultured normal human breast pre-adipocytes. The results indicated that Z and ZS stimulated the growth of pre-adipocytes isolated from normal human breast tissues by up-regulating cyclin D1 expression, while (-)-gossypol reversed this effect.

Climatology of persistent deep stable layers in Utah's Salt Lake Valley, USA

Abstract. The characteristics of winter season persistent deep stable layers (PDSLs) over Utah's Salt Lake Valley are examined using 30-year twice daily rawinsonde soundings. The results highlight the basic climatological characteristics of the PDSLs, including the strengths of the inversion, the frequency of the occurrence, and the duration of the events. The data analyses also reveal linear trend, interannual variability, as well as the relationship between the interannual variability of PDSLs and the variability of large-scale circulations. Finally, the study investigates the large-scale atmosphere conditions accompanying the formation and destruction of the PDSL episodes.

In vitro transformation of MCF-10A cells by sera harvested from heifers two months post-Zeranol implantation

Among many risk factors of breast cancer, estrogens and non-estrogenic endocrine disruptors are considered to play critical roles in human breast carcinogenesis. Zeranol (Z) is a non-steroidal agent with potent estrogenic activity and has been widely used as an FDA approved beef growth promoter in the US. Recently, concerns have been raised about the potential adverse health risk by consumption of products containing biologically active Z and its metabolites. By utilizing cell proliferation assay, soft agar assay, quantitative real-time PCR and Western blotting analysis, we examined the potentially tumorigenic activity of bio-active Z containing sera harvested from heifers two months post Z-implantation and the underlying mechanisms. Our results showed that the growth of MCF-10A exposed to 0.2, 1 and 5% Z-containing serum (ZS) treatment for 3 weeks was 1.3, 1.75 and 1.8-fold faster compared to that of the control sera. After further investigation, we found that ZS increased cyclin D1 and decreased p53 expression at the mRNA and protein levels in MCF-10A compared to the controls. More importantly, treatment of 1% Z-containing sera for 21 days stimulated MCF-10A cells anchorage-independent colony formation in soft agar which illustrates its capability of inducing human normal breast epithelial cell neoplastic transformation. Our experimental results suggest that long-term exposure of low levels of Z and its metabolites contained in beef products might be a potential risk factor in human breast cancer initiation and development.

Serum derived from zeranol-implanted ACI rats promotes the growth of human breast cancer cells in vitro

BACKGROUND

Zeranol (Z) is a non-steroidal anabolic growth promoter with potent estrogenic activity that is widely used as a growth promoter in the US beef industry. Consumption of beef derived from zeranol-implanted cattle may be a risk factor for breast cancer.

MATERIALS AND METHODS

The effect of serum on the proliferation of human breast cancer MCF-7 cell line and primary cultured human breast epithelial cells (PCHBECs) was investigated. ACI rats were implanted with 12 mg zeranol pellet and the serum was harvested at day 110 after implantation. The effect of zeranol-serum on mRNA expression of cell cycle regulating gene (cyclin D1) and tumor suppressor genes (p53, and p21) was evaluated using real-time RT-PCR.

RESULTS

The serum derived from ACI rats 110 days post-zeranol implantation significantly promoted the proliferation of MCF-7 cells and primary cultured human breast epithelial cells compared to control serum. Zeranol-serum up-regulated cyclin D1 and down-regulated p53 and p21 expression in PCHBECs compared with control serum.

CONCLUSION

Bio-active zeranol metabolites contained in meat produced from cattle after zeranol implantation may be a risk factor for breast cancer.

Antioxidant properties of peptide fractions from silver carp (Hypophthalmichthys molitrix) processing by-product protein hydrolysates evaluated by electron spin resonance spectrometry

Silver carp processing by-product protein is usually discarded as an industrial solid waste. In this study the protein was recovered using a pH-shift method, after which seven commercial proteases were separately employed to prepare antioxidative hydrolysates. Among the hydrolysates, pepsin hydrolysates, which had the highest free radical-scavenging activity, were further separated into five peptide fractions, SCPH-I (>10kDa), SCPH-II (5-10kDa), SCPH-III (3-5kDa), SCPH-IV (1-3kDa), and SCPH-V (<1kDa), by using ultrafiltration. The antioxidative properties of the peptide fractions were investigated, using a free radical-scavenging assay, by electron spin resonance. The results show that SCPH-V had the highest scavenging effects on DPPH (1,1-diphenyl-2-picrylhydrazyl), hydroxyl and superoxide anion radicals. SCPH-V had potent antioxidant activity in the prevention of the peroxidation of linoleic acid and alleviation of H2O2-induced oxidative stress in human intestinal epithelial caco-2 cells. The results indicated that the antioxidant capacity of silver carp by-product hydrolysates could be enhanced by ultrafiltration.

Aromatase expression in leptin-pretreated human breast pre-adipocytes is enhanced by zeranol and suppressed by (-)-gossypol

BACKGROUND

Obesity is associated with an increased risk of estrogen-dependent breast cancer. Recently, concerns have been raised regarding the role of zeranol (Z), a non-steroidal anabolic growth promoter with potent estrogenic activity widely used in the U.S.A. beef industry, as a possible contributor to an increased incidence of human breast cancer. This study hypothesized that obese individuals may be at greater risk of developing zeranol-induced breast cancer.

MATERIALS AND METHODS

The aromatase mRNA expression level of three cell types isolated from adipose tissues were assayed by RT-PCR, and the cell proliferation of primary cultured human normal breast pre-adipocytes (HNBPADs) was investigated using the CellTiter96® non-radioactive method. The effects of Z and gossypol on aromatase expression of leptin-pretreated HNBPADs were evaluated by RT-PCR.

RESULTS

HNBPADs expressed higher aromatase than primary cultured human breast epithelial cells and stromal cells. Z enhanced the mitogenic activity of leptin and increased aromatase expression in HNBPADs. Moreover, (-)-gossypol counteracted Z- and leptin-induced cell proliferation and aromatase expression.

CONCLUSION

These results suggested that bioactive Z metabolites contained in meat produced from Z-implanted beef cattle may increase estrogen biosynthesis in obese individuals by increasing aromatase expression and estrogen production, which will promote cell sensitivity and increase breast cancer cell growth.

Zeranol may increase the risk of leptin-induced neoplasia in human breast

Breast cancer and obesity are serious health problems and their relationship has been studied for many years. Leptin is mainly secreted by adipocytes and plays a key role in breast cancer development. Leptin expression is up-regulated in obese individuals and promotes breast cancer cell growth. On the other hand, exposure to environmental estrogens has been found to be directly related to breast cancer. Zeranol (Z) is a non-steroidal anabolic growth promoter used in the beef industry in the US. This study focused on the evaluation of Z and Z-containing sera (ZS) and its adverse health risk to human consumption of Z-containing meat produced from Z-implanted beef cattle. We hypothesized that Z increases the risk of breast neoplasia in women, particularly in obese women. A cell proliferation assay, ELISA analysis, RT-PCR and Western blot analysis were conducted. Our study demonstrated that Z and ZS collected from Z-implanted heifers stimulated the proliferation of primary cultured human normal breast epithelial cells (HNBECs) by up-regulating cyclin D1 expression. Leptin increased the sensitivity of HNBECs to Z, and Z increased the ability of HNBECs to secrete leptin. These results suggest an interaction between leptin and Z in HNBECs. Furthermore, Z may play a role in leptin-induced breast neoplasia.

Serum harvested from heifers one month post-zeranol implantation stimulates MCF-7 breast cancer cell growth

Breast cancer is a serious disease in the US. Numerous risk factors have been linked to this disease. The safety of using growth promoters, such as zeranol, remains under debate due to the lack of sufficient in vitro and in vivo evidence. Using CellTiter 96(™) Aqueous Non-Radioactive Cell Proliferation assay, real-time PCR and Western blot analysis, we evaluated the effects of sera harvested from experimental and control heifers before and after one month of zeranol implantation on the growth of human breast cancer cell line MCF-7 as well as the involved mechanisms. We found that sera harvested from the heifers following one month of zeranol implantation were more mitogenically potent in stimulating the proliferation of MCF-7 cells when compared to sera harvested from the same heifers before zeranol implantation and the control heifers. Further investigation found that dextran-coated charcoal suppressed the stimulating effect of the sera on MCF-7 cell growth. The mechanisms involved in the MCF-7 cell proliferation stimulated by zeranol-containing sera may include up-regulation of cyclin D1 and down-regulation of p53 and p21 expression at the mRNA and protein levels in the cells. The results suggest that the consumption of beef products containing biologically active residues of zeranol or its metabolites is a risk linked to breast cancer development. Further investigation is required in order to clarify this critical issue.

CHARMM general force field: A force field for drug-like molecules compatible with the CHARMM all-atom additive biological force fields

The widely used CHARMM additive all-atom force field includes parameters for proteins, nucleic acids, lipids, and carbohydrates. In the present article, an extension of the CHARMM force field to drug-like molecules is presented. The resulting CHARMM General Force Field (CGenFF) covers a wide range of chemical groups present in biomolecules and drug-like molecules, including a large number of heterocyclic scaffolds. The parametrization philosophy behind the force field focuses on quality at the expense of transferability, with the implementation concentrating on an extensible force field. Statistics related to the quality of the parametrization with a focus on experimental validation are presented. Additionally, the parametrization procedure, described fully in the present article in the context of the model systems, pyrrolidine, and 3-phenoxymethylpyrrolidine will allow users to readily extend the force field to chemical groups that are not explicitly covered in the force field as well as add functional groups to and link together molecules already available in the force field. CGenFF thus makes it possible to perform "all-CHARMM" simulations on drug-target interactions thereby extending the utility of CHARMM force fields to medicinally relevant systems.

A one-year investigation of the relationship between serum GH levels and the growth of F(4) transgenic and non-transgenic common carp Cyprinus carpio

It has been demonstrated that growth hormone (GH) transgenic fish often posses a trait for fast growth. Here, we investigated the growth of F(4)'all-fish' GH transgenic carp Cyprinus carpio and their serum GH levels for a year. The results showed that F(4) all-fish GH transgenic carp were significantly larger in body mass (c. two-fold, P < 0.001) and body length (c. 1.3 fold, P < 0.001), compared with the non-transgenic group. The discrepancy of serum GH levels between the transgenic carp group and control group is 54 fold, when the water temperature was 12-34 degrees C. When the water temperature decreased to 3.5 degrees C in January, the discrepancy was 256 fold. The serum GH level of the transgenic group was relatively constant, while that of control varied greatly based on month and water temperature. The changes of growth rates between the transgenic group and the control group were similar for a year. Taken together, the results indicated that F(4) all-fish GH transgenic carp had not only higher and constant serum GH levels but also a significant fast-growing effect, compared with the control. To our knowledge, this is the first report on a one-year investigation of growth trait and serum growth hormone level in F(4) all-fish GH transgenic carp.