Abstract P1-02-09: Targeting breast cancer stem cell state equilibrium through modulation of redox signaling

Breast cancer stem cells (BCSCs) maintain the plasticity to transition between quiescent mesenchymal- (M) and proliferative epithelial-like (E) states, but how this plasticity is regulated under metabolic/oxidative stress is poorly understood. Here, we show that M- and E-BCSCs exhibit markedly different sensitivities to the inhibitors of glycolysis and redox metabolism. Metabolic/Oxidative stress generated by 2DG/H2O2 or hypoxia promotes ROSlo M-BCSCs transition to their ROShi E-state. This transition is reversed by the antioxidant N-acetyl cysteine and facilitated by the activation of the AMPK-HIF1α axis. Moreover, E-BCSCs exhibit robust expression of NRF2/NFE2L2 and a wide variety of NRF2 downstream antioxidant responsive genes including the family of drug transporters and detoxification enzymes, NADPH production as well as the thioredoxin (TXN) and glutathione (GSH) antioxidant pathways. Suppression of NRF2 activity by a small-molecular inhibitor Trigonelline or shNRF2 mediated knockdown significantly decreased ALDH+ E- but not CD24-CD44+ M-BCSCs. This specific vulnerability of E-BCSCs to the inhibition of NRF2-mediated antioxidant defenses was also observed following inhibition of the downstream TXN and GSH antioxidant pathways, which promotes ROS-mediated differentiation and subsequent apoptosis of E-BCSCs. Co-inhibition of glycolysis and TXN/GSH pathways synergistically suppressed tumor growth and tumor initiating potential in two patient-derived xenograft models of triple negative breast cancer by eliminating both M- and E-BCSCs. Together, our studies reveal novel cellular and molecular mechanisms demonstrating how modulation of redox signaling regulates the equilibrium of two distinct BCSC states. These studies define the metabolic vulnerabilities of M- and E-BCSCs, and also provide a novel therapeutic approach to collectively target these distinct CSC states. As the CSC state equilibrium may be similarly regulated across a spectrum of tumors with diverse oncogenic drivers, this approach may have broad therapeutic applicability.

Citation Format: Luo M, Shang L, Brooks M, Jiagge E, Zhu Y, Conley S, Fath MA, Harouaka R, Merajver SD, Spitz DR, Wicha MS. Targeting breast cancer stem cell state equilibrium through modulation of redox signaling [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-02-09.

Plasminogen activator inhibitor-1 regulates the vascular expression of vitronectin

Essentials Vitronectin (VN) is produced by smooth muscle cells (SMCs) and promotes neointima formation. We studied the regulation of vascular VN expression by plasminogen activator inhibitor-1 (PAI-1). PAI-1 stimulates VN gene expression in SMCs by binding LDL receptor-related protein 1. Stimulation of VN gene expression may be a mechanism by which PAI-1 controls vascular remodeling.

SUMMARY

Background Increased expression of vitronectin (VN) by smooth muscle cells (SMCs) promotes neointima formation after vascular injury, and may contribute to chronic vascular diseases, such as atherosclerosis. However, the molecular regulation of vascular VN expression is poorly defined. Given the overlapping expression profiles and functions of VN and plasminogen activator inhibitor (PAI)-1, we hypothesized that PAI-1 regulates vascular VN expression. Objectives To determine whether PAI-1 regulates VN expression in SMCs and in vivo. Methods The effects of genetic alterations in PAI-1 expression, pharmacologic PAI-1 inhibition and recombinant PAI-1 on SMC VN expression were studied, and vascular VN expression in wild-type (WT) and PAI-1-deficient mice was assessed. Results VN expression was significantly lower in PAI-1-deficient SMCs and significantly increased in PAI-1-overexpressing SMCs. PAI-1 small interfering RNA and pharmacologic PAI-1 inhibition significantly decreased SMC VN expression. Recombinant PAI-1 stimulated VN expression by binding LDL receptor-related protein-1 (LRP1), but another LRP1 ligand, α2 -macroglobulin, did not. As compared with WT controls, carotid artery VN expression was significantly lower in PAI-1-deficient mice and significantly higher in PAI-1-transgenic mice. In a vein graft (VG) model of intimal hyperplasia, VN expression was significantly attenuated in PAI-1-deficient VGs as compared with WT controls. The plasma VN concentration was significantly decreased in PAI-1-deficient mice versus WT controls at 4 weeks, but not at 5 days or 8 weeks, after surgery. Conclusions PAI-1 stimulates SMC VN expression by binding LRP1, and controls vascular VN expression in vivo. Autocrine regulation of vascular VN expression by PAI-1 may play important roles in vascular homeostasis and pathologic vascular remodeling.

Inhibition of pulmonary carcinoma proliferation or metastasis of miR-218 via down-regulating CDCP1 expression

OBJECTIVE

Pulmonary carcinoma is one common malignant tumor with a high risk of recurrence and metastasis. Non-small cell lung cancer (NSCLC) is the most common subtype. As one tumor biomarker, microRNA (miR) has tissue sensitivity and can facilitate oncogene or inhibit tumor suppressor gene. MiR-218 has abnormal expression and can work as one molecular marker for tumors. However, its expression and function mechanism in lung cancer cells have not been fully illustrated.

MATERIALS AND METHODS

In vitro cultured pulmonary adenoma A549 cells and normal bronchial epithelial cell line 16HBE were tested for miR-218 expression. A549 cells were transfected with miR-218 mimic or negative controls, followed by real-time PCR quantifying for miR-218. MTT method was used to test cell proliferation, whilst Transwell chamber was adopted for measuring cell invasion. Dual luciferase reporter gene assay (DLRGA) was used to test target relationship between miR-218 and CDCP1. Western blot was used to test CDCP1 expression.

RESULTS

MiR-218 was down-regulated in A549 cells compared to 16HBE (p<0.05). Transfection of miR-218 mimic significantly facilitated miR-218 expression, inhibited tumor proliferation or invasion. As the target gene of miR-218, CDCP1 expression was suppressed by miR-218 over-expression (p<0.05 compared to control group).

CONCLUSIONS

MiR-218 inhibits NSCLC proliferation or metastasis via down-regulating CDCP1, and can work as one novel molecular target for lung cancer diagnosis.

PyMIF enhances the inflammatory response in a rodent model by stimulating CD11b(+) Ly6C(+) cells accumulation in spleen

Macrophage migration inhibitory factor (PMIF) expressed by Plasmodium parasites has been proved to be similar to the mammalian MIF in both structure and biological activity and is a critical upstream regulator in antimalaria innate immunity. In this work, using a genetically modified (MIF-KO) strain of highly lethal rodent Plasmodium yoelii 17XL (Py17XL), we found that PyMIF could increase the secretion of pro-inflammatory factors by eliciting the CD11b(+) Ly6C(+) cells accumulated in the spleen of infected mouse. In addition, the chemotactic effect of PyMIF was demonstrated to associate with cell receptors CXCR2, CXCR4 and the cell surface markers ICAM-1, LFA-4.

Therapy of tacrolimus combined with corticosteroids in idiopathic membranous nephropathy

We evaluated the efficacy and safety of tacrolimus (TAC) combined with corticosteroids in treating patients with idiopathic membranous nephropathy (IMN). One hundred seventy-seven biopsy-proven IMN patients were recruited in this retrospective clinical study. Sixty patients received TAC (target blood concentration of 4–8 ng/mL) and 117 patients received daily cyclophosphamide (CYC, 100 mg) combined with prednisone. Remission rates at the end of the first, second and third month in the TAC group were significantly higher than that in the CYC group (1st: 35.0 vs 19.7%, P<0.05; 2nd: 56.7 vs 38.5%, P<0.05; 3rd: 76.7 vs 59.0%, P<0.05). In the first 3 months, daily urinary protein and serum albumin in the TAC group obtained a better improvement than that in the CYC group (P<0.05). At the end of the sixth and the twelfth month, the remission rates, daily urinary protein and serum albumin were all comparable between the two groups (P>0.05). No significant difference of relapse rate between the groups was found (16.3 vs 12.0%, P>0.05). Patients were more likely to develop glucose intolerance in the TAC group. The TAC regimen obtained more benefits in treating IMN patients, especially in the first 3 months, than the CYC regimen.

Indoor human thermal adaptation: dynamic processes and weighting factors

In this study, we explore the correlations between indoor climate change and human thermal adaptation, especially with regard to the timescale and weighting factors of physiological adaptation. A comparative experiment was conducted in China where wintertime indoor climate in the southern region (devoid of space heating) is much colder than in the northern region (with pervasive district heating). Four subject groups with different indoor thermal experiences participated in this climate chamber experiment. The results indicate that previous indoor thermal exposure is an important contributor to occupants' physiological adaptation. More specifically, subjects acclimated to neutral-warm indoors tended to have stronger physiological responses and felt more uncomfortable in moderate cold exposures than those adapted to the cold. As for the driving force of thermal adaptation, physiological acclimation is an important aspect among all the supposed adaptive layers. However, the physiological adaptation speed lags behind changes in the overall subjective perception.

Zfp462 deficiency causes anxiety-like behaviors with excessive self-grooming in mice

Zfp462 is a newly identified vertebrate-specific zinc finger protein that contains nearly 2500 amino acids and 23 putative C2H2-type zinc finger domains. So far, the functions of Zfp462 remain unclear. In our study, we showed that Zfp462 is expressed predominantly in the developing brain, especially in the cerebral cortex and hippocampus regions from embryonic day 7.5 to early postnatal stage. By using a piggyBac transposon-generated Zfp462 knockout (KO) mouse model, we found that Zfp462 KO mice exhibited prenatal lethality with normal neural tube patterning, whereas heterozygous (Het) Zfp462 KO (Zfp462^+/- ) mice showed developmental delay with low body weight and brain weight. Behavioral studies showed that Zfp462^+/- mice presented anxiety-like behaviors with excessive self-grooming and hair loss, which were similar to the pathological grooming behaviors in Hoxb8 KO mice. Further analysis of grooming microstructure showed the impairment of grooming patterning in Zfp462^+/- mice. In addition, the mRNA levels of Pbx1 (pre-B-cell leukemia homeobox 1, an interacting protein of Zfp462) and Hoxb8 decreased in the brains of Zfp462^+/- mice, which may be the cause of anxiety-like behaviors. Finally, imipramine, a widely used and effective anti-anxiety medicine, rescued anxiety-like behaviors and excessive self-grooming in Zfp462^+/- mice. In conclusion, Zfp462 deficiency causes anxiety-like behaviors with excessive self-grooming in mice. This provides a novel genetic mouse model for anxiety disorders and a useful tool to determine potential therapeutic targets for anxiety disorders and screen anti-anxiety drugs.

Serum soluble RAGE level inversely correlates with left ventricular hypertrophy in essential hypertension patients

Soluble receptor for advanced glycation end-products (sRAGE) acts as a decoy to prevent interaction between RAGE and its pro-inflammatory ligands. sRAGE levels have been found to decrease in chronic inflammatory diseases, including hypertension. However, few data have been reported concerning the association between serum sRAGE levels and hypertensive left ventricular hypertrophy (LVH). Fasting blood samples were obtained from 209 essential hypertensive patients, and sRAGE levels were measured using a commercially available double-sandwich enzyme-linked immunosorbent assay kit. All patients underwent complete transthoracic echocardiographic examination. LVH was defined as a left ventricular mass index >115 g/m(2) for men and >95 g/m(2) for women. Eighty-one hypertensive patients (38.76%) were categorized in the LVH(+) group. Age (P = 0.009), hypertension duration (P = 0.013), triglyceride levels (P = 0.028), and systolic blood pressure (P = 0.026) were higher, and sRAGE and high-density lipoprotein cholesterol levels were lower in the LVH(+) group compared with the LVH(-) group. Multivariate logistic regression analysis showed that sRAGE level [odds ratio (OR) = 0.916; 95% confidence interval (CI) = 0.864-0.984; P = 0.003], hypertension duration (OR = 1.024; 95%CI = 1.003-1.052; P = 0.027), and triglyceride level (OR = 1.017; 95%CI = 1.005-1.039; P = 0.018) were independent predictors of LVH in hypertensive patients. In conclusion, serum sRAGE level was inversely associated with LVH in hypertensive patients.

Distribution of common pathogens in patients with pyogenic liver abscess in China: a meta-analysis

Pyogenic liver abscess (PLA) is a potentially life-threatening disease in many parts of the world, especially in Asia. The aim of this study was to quantify the proportion of common pathogens in patients with PLA in China, using a meta-analysis method based on systematic review of published studies. Several electronic databases were searched to identify the studies reporting the pathogens of PLA. We performed a meta-analysis to calculate the pooled proportion of pathogens and subgroup analysis among the included studies using R 3.1.1 software. In total, 183 studies were included in our final analysis, Klebsiella spp (54 %), Escherichia spp (29 %), Enterobacter spp (9 %), Proteus spp (6 %) and Pseudomonas spp (5 %) comprised the major gram-negative bacteria. Gram-positive bacteria mainly included Staphylococcus spp (13 %), Streptococcus spp (8 %) and Enterococcus spp (7 %). The distribution of pathogens in PLA patients were different in different economic regions in China. The proportion of Klebsiella spp had an upward tendency in recent years compared to other pathogens. In addition, the proportion of common pathogens in PLA patients with diabetes mellitus (DM) were carried out indicating that the dominant pathogens were Klebsiella spp (66 %), Escherichia spp (21 %) and Enterobacter spp (11 %). This meta-analysis showed that the main pathogens of PLA were Klebsiella spp, Escherichia spp, Staphylococcus spp, and Enterobacter spp in China. To ensure a precise estimate of the epidemiology of the pathogens, further large-scale or even a population-based study is needed.

[Prevalence and risk factors of hypertension among residents of 30 years or above years old in Pengzhou city of Sichuan province]

OBJECTIVE

To investigate the prevalence and risk factors of hypertension among residents in Pengzhou city of Sichuan province.

METHODS

Among 20 townships in Pengzhou city of Sichuan Province, 14 townships were selected using a clustered sampling based on the economic level and distance. The registered residents in the selected townships aged 30-79 years were recruited for a comprehensive survey from 2004 to 2007. A total of 55 687 residents (21 315 males and 34 372 females) were selected based on a face to face questionnaire interview and physical examination; the patient group included 14 151 residents with hypertension and the control group had 41 536 residents without hypertension were selected. Multivariate logistic regression model was used to investigate the influence factors for hypertension. OR (95%CI) values were calculated. Different levels of risk exposure factors were transformed into the risk scores using a statistical model.

RESULTS

The prevalence rate of hypertension was 25.41% among residents aged 30 years or above in Pengzhou (14 151/55 687), 28.95% (6 170/21 315) for male residents and 23.22% (7 981/34 372) for female residents. Multivaraite logistic regression analysis showed that main risk factors for hypertension in male residents were age, low educational level, widower, low household income, no medical insurance, no fresh fruits intake, high body mass index (BMI), high waist to hip ratio, and low physical activity, which was less than 3 metabolic equivalent of task (MET) level, among which the highest three riskswere (not including the social demographic characteristics) BMI≥28 kg/m(2), waist to hip ratio ≥0.90, and not consuming fresh fruits. OR (95% CI) values for these three key factors were 3.74 (3.27-4.28), 1.34 (1.24-1.44), and 1.27 (1.14-1.41), respectively. The corresponding risk scores for these factors were 2.993, 1.102, and 1.237, respectively. Main risk factors for hypertension in female residents were age, working hours, no medical insurance, fewer number of family members, no fresh fruits intake, smoking, never drinking tea, no dairy products intake, high BMI, highwaist to hip ratio and low physical activity, among which the highest three risks were (not including the social demographic characteristics) BMI ≥28 kg/m(2), MET level, and waist to hip ratio ≥0.85. OR (95% CI) values for these three key factors were 3.30 (3.02-3.60), 1.35 (1.22-1.51), and 1.33 (1.23-1.44), respectively. The corresponding risk scores for these factors were 2.390, 1.263, and 1.051, respectively.

CONCLUSION

The prevalence rate of hypertension among the residents over 30 years of age in Pengzhou city was 25.41%. The main risk factors were age, not consuming fresh fruits, high BMI, high waist to hip ratio, and low MET level.

Synthesis of cyclic monothiocarbonates via the coupling reaction of carbonyl sulfide (COS) with epoxides

Two guanidine bases were used as organocatalysts for the synthesis of cyclic monothiocarbonates via the coupling reaction of carbonyl sulfide (COS) and epoxides.

De novo assembly, functional annotation, and marker development of Asian pear (Pyrus pyrifolia) fruit transcriptome through massively parallel sequencing

This study investigated the Asian pear transcriptome using the RNA-Seq normalized fruit cDNA library to create a transcriptomic resource for unigene and marker discovery. Following the removal of lowquality reads, 127,085,054 trimmed reads were assembled de novo to yield 37,649 non-redundant unigenes with an average length of 599 bp. Alternative splicing events were detected in 4121 contigs. A total of 30,560 single nucleotide polymorphisms (SNPs) and 7443 simple sequence repeat (SSR) makers were obtained. Approximately 21,449 (56.9%) unigenes were categorized into three gene ontology groups; 3682 (9.8%) were classified into 25 cluster of orthologous groups; and 10,451 (27.8%) were assigned to six Kyoto Encyclopedia of Genes and Genomes pathways. Differentially expressed genes were investigated using the reads per kilobase of the exon model per million reads methodology. A total of 546 unigenes showed significant differences in expression levels at different fruit developmental stages. Gene ontology categories associated with various aspects, including carbohydrate metabolic processes, transmembrane transport, and signal transduction, were enriched with genes with divergent expressions. These Pyrus pyrifolia transcriptome data provide a rich resource for the discovery and identification of new genes. Furthermore, the numerous putative SSRs and SNPs detected in this study will be important resources for the future development of a linkage map or of marker-assisted breeding programs for the Asian pear.

Low level measurement of (60)Co by gamma ray spectrometry using γ-γ coincidence

This paper presents the latest development of the laboratory to measure the natural and artificial massic activities in environmental samples. The measurement method of coincident emitters by gamma-gamma coincidence using an anti-Compton device and its digital electronics is described. Results obtained with environmental samples are shown. Despite its low efficiency, this method decreases detection limits of (60)Co for certain samples compared to conventional gamma-ray spectrometry due to its very low background.

Reciprocal positive regulation between Cx26 and PI3K/Akt pathway confers acquired gefitinib resistance in NSCLC cells via GJIC-independent induction of EMT

Gefitinib efficiency in non-small-cell lung cancer (NSCLC) therapy is limited due to development of drug resistance. The molecular mechanisms of gefitinib resistance remain still unclear. In this study, we first found that connexin 26 (Cx26) is the predominant Cx isoform expressed in various NSCLC cell lines. Then, two gefitinib-resistant (GR) NSCLC cell lines, HCC827 GR and PC9 GR, from their parental cells were established. In these GR cells, the results showed that gefitinib resistance correlated with changes in cellular EMT phenotypes and upregulation of Cx26. Cx26 was detected to be accumulated in the cytoplasm and failed to establish functional gap-junctional intercellular communication (GJIC) either in GR cells or their parental cells. Ectopic expression of GJIC-deficient chimeric Cx26 was sufficient to induce EMT and gefitinib insensitivity in HCC827 and PC9 cells, while knockdown of Cx26 reversed EMT and gefitinib resistance in their GR cells both in vitro and in vivo. Furthermore, Cx26 overexpression could activate PI3K/Akt signaling in these cells. Cx26-mediated EMT and gefitinib resistance were significantly blocked by inhibition of PI3K/Akt pathway. Specifically, inhibition of the constitutive activation of PI3K/Akt pathway substantially suppressed Cx26 expression, and Cx26 was confirmed to functionally interplay with PI3K/Akt signaling to promote EMT and gefitinib resistance in NSCLC cells. In conclusion, the reciprocal positive regulation between Cx26 and PI3K/Akt signaling contributes to acquired gefitinib resistance in NSCLC cells by promoting EMT via a GJIC-independent manner.

Type II deiodinase polymorphisms and serum thyroid hormone levels in patients with mild cognitive impairment

We investigated type II deiodinase (DIO2) polymorphisms and serum thyroid hormone levels in subjects with mild cognitive impairment (MCI) in a Uygur population. We studied the DIO2 Thr92Ala (rs225014) and ORFa-Gly3Asp (rs12885300) polymorphisms of 129 unrelated MCI cases and 131 matched controls. All subjects were genotyped using SNaPshot SNP genotyping assays. Serum thyroid hormone levels were measured by radioimmunoassay. Levels of serum triiodothyronine and thyroxine in the MCI group were significantly lower than those in the control group. Genotype and allele frequencies in the DIO2 gene between the MCI and control groups were not significantly different. There was no association in genotype and allele frequencies of Thr92Ala between genders in both groups. ORFa-Gly3Asp genotype and allele frequencies were significantly different in patients and controls by gender. The Asp allele was less frequent among male MCI patients compared to controls (odds ratio = 0.471, 95% confidence interval = 0.261-0.848). However, female Asp carriers were more frequent among MCI patients than among controls (odds ratio = 2.842, 95% confidence interval = 1.326-6.09). Serum levels of triiodothyronine and thyroxine were lower in individuals of the Ala/Ala genotype than in those with the Thr/Thr or Thr/Ala genotype. Serum levels of triiodothyronine were lower in male Gly/Gly carriers than in Gly/Asp or Asp/Asp carriers. Decreased serum levels of triiodothyronine and thyroxine may influence the incidence of MCI in the Uygur population. DIO2 gene polymorphisms may play a role in the incidence of MCI in male patients.