Seasonal variations in male mice at the time of sexual maturation

The sexual maturation of male mice reared under constant laboratory conditions was studied in animals born in different months of the year. The body weights were significantly affected by the month of birth. Males born in March and May were heavier at 4 and 5 weeks of age than those born in autumn and winter. As indicated by the relative weights of accessory glands, males born in spring matured earlier compared with animals born in other months of the year. Variation in the relative testicular weights during maturation was not influenced by the month of birth. Female mice also showed a significant relationship between the month of birth and sexual maturation. Females born in March reached puberty, as measured by the age of vaginal opening and first oestrus, earlier than those born in other months of the year.

C3435T Polymorphism of the ABCB1 Gene in Polish Patients with Inflammatory Bowel Disease: A Case-Control and Meta-Analysis Study

P-glycoprotein encoded by the ABCB1 gene constitutes a molecular barrier in the small and large bowel epithelium, and its different expression may influence susceptibility to inflammatory bowel disease (IBD). We aimed to assess the contribution of the C3435T polymorphism to disease risk in the Polish population. A total of 100 patients (50 Crohn's disease (CD), 50 ulcerative colitis (UC)) and 100 healthy controls were genotyped for the single nucleotide polymorphism (SNP) C3435T by using the PCR-RFLP method. Patients were classified on the basis of disease phenotype and the specific treatment used. A meta-analysis was carried out of our results and those from previously published Polish studies. There was no significant difference in allele and genotype frequencies in IBD patients compared with controls. For CD patients, a lower frequency of TT genotype in those with colonic disease, a lower frequency of T allele, and a higher frequency of C allele in those with luminal disease were observed, whereas for UC patients, a lower frequency of CT genotype was observed in those with left-sided colitis. A meta-analysis showed a tendency towards higher prevalence of CC genotype in UC cases. These results indicate that the C3435T variants may confer a risk for UC and influence disease behaviour.

Luminol-chemiluminescence in free peritoneal cells in hemorrhagic shock in rats treated with PAF-receptor-antagonist BN 52021

The activity of rat peritoneal cells were assessed by the phorbol mirystinian acetate (PMA)-induced luminol chemiluminescence (LCL). Results in control groups (0 - no manipulation, and I - carotid artery cannulation) were compared with those in the untreated hemorrhagic shock (group II), in the shock treated with the standard polyelectrolyte solution (PES) (group III), and in shock treated with PAF receptor-antagonist BN 52021 + PES (group IV). The maximal and the most rapid LCL was observed in the group treated with BN 52021 (group IV), while chemiluminescent response in the the untreated shock (group II) and in shock treated with PES was minimally expressed and late. The findings indicate for a rapid activation of peritoneal cells during ca 1 hour of hemorrhagic shock. This leads to exhausting their ability to the superoxide anion generation 15 minutes later. Peritoneal cells obtained from the group treated with the BN 52021 revealed a preserved ability to the respiratory burst. It can be concluded that BN 52021 effectively inhibits activation of the PC during hemorrhagic shock.

Abstract PD3-15: Novel cFlip inhibitor suppresses chemotherapy-induced breast cancer stem cell activity through blocking HIF1-α

Background: The emergence of the cancer stem cell (CSC) hypothesis has helped to explain previously poorly understood clinical concepts such as metastases, late tumour recurrence and resistance to chemotherapy. Triple Negative Breast Cancer (TNBC) has the worst prognosis of all types of breast cancer with a more frequent relapse rate and reduced length of survival in metastatic disease. It has been shown to contain a higher proportion of CSCs than other types of breast cancer. Paclitaxel, a taxane in widespread use in breast cancer, induces apoptosis in a ligand-independent manner through the extrinsic apoptosis pathway. cFLIP is both an antagonist of this apoptosis pathway and has the ability to form aggregates that interfere with the ubiquitylation and subsequent degradation of both HIF1α and β-catenin- two molecules involved in CSC-signalling. Using a novel compound targeted against cFLIP, we wanted to assess whether its combination with paclitaxel effectively targeted CSCs, particularly in TNBC.

Methods: In vitro experiments were used to assess the effect on cell viability, mammosphere formation and ALDH+ of both chemotherapy and our novel agent, OH14. We then used siRNA-mediated knockdown of cFLIP to confirm an on-target effect. Annexin V assays were used to assess apoptosis and both Western blotting and qPCR was used to examine the effect of paclitaxel and OH14 on protein levels and gene expression of CSC-signalling pathways. Athymic mice were used to in serial dilution experiments and for in vivo treatmenst with paclitaxel and OH14 on a TNBC cell line.

Results: We established an in vitro model demonstrating that a wide range of chemotherapeutic agents (FEC, Paclitaxel and Docetaxel) increased CSC-like behaviour and the ALDH+ population in a broad range of breast cancer cell lines. A mathematical model demonstrated that chemotherapy increased the absolute number of CSCs after treatment suggesting that CSC-like signaling was being induced. OH14, our novel compound, sensitised Triple Negative Breast Cancer (TNBC) cell lines to paclitaxel by increasing its apoptotic effect but had a more profound effect on mammosphere formation and ALDH positivity. This suggests that it preferentially targets CSCs. Serial dilution experiments demonstrated that chemotherapy increased the tumour forming potential of a TNBC cell line in vivo and that this effect was abrogated with OH14. Treatment of the same cell line in vivo demonstrated that paclitaxel +/- OH14 successfully targeted tumours but that the paclitaxel tumours recurred whereas those subject to combined treatment remained undetectable. Further experiments examining CSC signalling showed that HIF1α-mediated signalling was increased by paclitaxel and abrogated by the addition of OH14.

Conclusion: cFLIP has a dual effect in both increasing apoptosis and targeting signaling in TNBC CSCs. In a breast cancer subtype in desperate need of novel therapeutic strategies, targeting cFLIP warrants further investigation and progression towards clinical trials.

Citation Format: Robinson T, Turnham D, Gruca A, Piggott L, Clarkson R. Novel cFlip inhibitor suppresses chemotherapy-induced breast cancer stem cell activity through blocking HIF1-α [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 PD3-15.

Influence of oxy-LDL and interleukin-8 on the platelet/PMNs adhesion and on chemotaxis-mediated induction of iNOS in neutrophils

Selectin-P expression on platelets stimulated with thrombin was measured in terms of formation of "rosettes" according to Jungi et al. [9]. Selectin-P-mediated platelet/PMNs adhesion was inhibited by iloprost (IC50 = 5.0 nM), sodium nitroprusside (NaNP, IC50 = 0.93 microM) and interleukin-8 (IL-8, IC50 = 88 ng/ml), but activated dose-dependently by oxy-LDL (3-15 micrograms/ml). Glycogen-induced peritonitis in rats up-regulated the iNOS activity measured by the 2,3-[3H]-citrulline formation by the abdominal cavity PMNs up to 6 h after insult. Pretreatment with IL-8 (3 micrograms/300 g iv) decreased the amount of PMNs in ascites as well as its iNOS activity. Chemotaxis mediated iNOS gene expression of PMNs were measured by Northern blot hybridization. IL-8 (100 ng/ml) did not influence the PMNs iNOS gene expression induced by chemotaxis. We conclude that the decrease in iNOS activity by IL-8 involves postranslational modification of the enzyme activity.

Assessment of incretins in oral glucose and lipid tolerance tests may be indicative in the diagnosis of metabolic syndrome aggravation

Incretins stimulated by oral meals are claimed to be protective for the pancreatic beta cells, to increase insulin secretion, to inhibit glucagon release, slow gastric emptying (glucagon-like peptide-1) and suppress appetite. Recently it has however been suggested that glucagon-like peptide-1 (GLP-1) is putative early biomarker of metabolic consequences of the obesity associated proinflammatory state. The study was aimed to compare the release of incretins and some of early markers of inflammation at the fasting and postprandial period induced by functional oral glucose as well as lipid load in healthy controls and patients with metabolic syndrome (MS) to see if functional tests may be helpful in searching for the inflammatory status of patients. Fifty patients with MS and 20 healthy volunteers (C) participated in this study. The 3-hour oral glucose (OGTT) and the 8-hour oral lipid (OLTT) tolerance tests were performed. At fasting leptin and adiponectin, as well as every 30 minutes of OGTT and every 2 hours of OLTT blood concentration of GLP-1, glucose-dependent insulinotropic polypeptide (GIP), glucose, insulin, triglycerides, free fatty acids, glutathione peroxidase, interleukin-6, sE-selectin, monocyte chemoattractant protein-1 (MCP1) and visfatin were measured. At fasting and during both OGTT and OLTT the level of incretins did not differ between the MS and the C group. Both glucose and lipids reach food activated incretins secretion. Glucose was the main GLP-1 release activator, while the lipid load activated evidently GIP secretion. A significantly larger AUC-GIP after the lipid-rich meal over the carbohydrate meal was observed, while statistically bigger value of AUC-GLP-1 was noticed in OGTT than in OLTT (P < 0.001) within each of the investigated groups. In patients with the highest fasting plasma GIP concentration (3(rd) tertile), IL-6, MCP-1, sE-selectin and visfatin blood levels were increased and correlated with glutathione peroxydase, leptin/adiponectin ratio, higher visfatin and interleukin-6 levels. The fat containing meals stimulate the long-lasting release of incretins, mainly GIP, parallel to the increase of the markers of low grade inflammation associating obesity in metabolic syndrome. The possibility of use of the postprandial (OLTT) GIP release measurement for the low grade inflammation progress in MS patients is suggested.

The N-Acetyltransferase 2 Polymorphism and Susceptibility to Inflammatory Bowel Disease: A Case-Control Study

The enzyme N-acetyltransferase 2 (NAT2) plays an important role in metabolism and detoxification of xenobiotics, including carcinogens and medications. We aimed to assess the contribution of the NAT2 polymorphism to susceptibility to inflammatory bowel disease (IBD) in the Polish population. The study involved 101 IBD patients and 100 healthy controls. The NAT2 gene mutations at positions 481T, 803G, 590A, and 857A were identified using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique on peripheral blood DNA samples. Carriers of the NAT2*5 allele had a greater chance of developing Crohn's disease (CD) (OR = 1.73, 95% CI 1.06-2.83). Also, the NAT2*4/5 genotype was more prevalent in CD patients (OR = 2.77, 95% CI 1.17-6.57). When compared to the control group, the prevalence of the NAT2*4/6 genotype in the IBD patient population was significantly lower (10.9% vs. 30.0%, p < 0.01). In the Polish population, polymorphism in the NAT2 gene may potentially alter susceptibility to IBD.