ALDH1A1-related stemness in high-grade serous ovarian cancer is a negative prognostic indicator but potentially targetable by EGFR/mTOR-PI3K/aurora kinase inhibitors

Poor chemotherapy response remains a major treatment challenge for high-grade serous ovarian cancer (HGSC). Cancer stem cells are the major contributors to relapse and treatment failure as they can survive conventional therapy. Our objectives were to characterise stemness features in primary patient-derived cell lines, correlate stemness markers with clinical outcome and test the response of our cells to both conventional and exploratory drugs. Tissue and ascites samples, treatment-naive and/or after neoadjuvant chemotherapy, were prospectively collected. Primary cancer cells, cultured under conditions favouring either adherent or spheroid growth, were tested for stemness markers; the same markers were analysed in tissue and correlated with chemotherapy response and survival. Drug sensitivity and resistance testing was performed with 306 oncology compounds. Spheroid growth condition HGSC cells showed increased stemness marker expression (including aldehyde dehydrogenase isoform I; ALDH1A1) as compared with adherent growth condition cells, and increased resistance to platinum and taxane. A set of eight stemness markers separated treatment-naive tumours into two clusters and identified a distinct subgroup of HGSC with enriched stemness features. Expression of ALDH1A1, but not most other stemness markers, was increased after neoadjuvant chemotherapy and its expression in treatment-naive tumours correlated with chemoresistance and reduced survival. In drug sensitivity and resistance testing, five compounds, including two PI3K-mTOR inhibitors, demonstrated significant activity in both cell culture conditions. Thirteen compounds, including EGFR, PI3K-mTOR and aurora kinase inhibitors, were more toxic to spheroid cells than adherent cells. Our results identify stemness markers in HGSC that are associated with a decreased response to conventional chemotherapy and reduced survival if expressed by treatment-naive tumours. EGFR, mTOR-PI3K and aurora kinase inhibitors are candidates for targeting this cell population. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

IFN-alpha regulates Toll-like receptor-mediated IL-27 gene expression in human macrophages

IL-27 is a novel member of the IL-12 cytokine family. IL-27 has pro- and anti-inflammatory properties, and it controls the responses of adaptive immunity. It promotes the differentiation of na?ve Th cells and suppresses the effector functions of Th17 cells. Biologically active IL-27 is a heterodimer composed of EBV-induced gene 3 (EBI3) and p28 proteins. We report that TLR-dependent expression of IL-27 in human macrophages is mediated by IFN-alpha. Stimulation of macrophages with agonists for TLR3 {polyinosinic:polycytidylic acid [poly(I:C)]}, TLR4 (LPS), or TLR7/8 (R848) results in concurrent expression of EBI3 and p28. The p28 expression is inhibited with neutralizing anti-IFN-alpha antibodies. Unlike poly(I:C), LPS, and R848, TLR2 agonist (S)-[2,3-bis(palmitoyloxy)-(2RS)-propyl]-N-palmitoyl-(R)-Cys-(S)-Ser(S)-Lys4-OH trihydrochloride does not stimulate macrophages to produce IFN-alpha, and therefore, it is not able to turn on the expression of p28. There is an IFN-stimulated response element (ISRE) in the p28 gene promoter. IFN-alpha enhances the expression of IFN regulatory factor 1 (IRF-1) in macrophages and induces binding of IRF-1 to the p28 ISRE site. The data provide a mechanistic basis for the IFN-alpha-mediated activation of IL-27. The data emphasize a role of IFN-alpha in immune responses, which rely on the recognition of pathogens by TLRs.     

Ictal localization by source analysis of infraslow activity in DC-coupled scalp EEG recordings

New bedside long-term DC-coupled EEG techniques have demonstrated that infraslow (<0.5 Hz) activity lateralizes temporal lobe seizures (Vanhatalo, S., Holmes, M.D., Tallgren, P., Voipio, J., Kaila, K., Miller, J.W., 2003a. Very slow EEG responses indicate the laterality of temporal lobe seizures: a DC-EEG study. Neurology 60, 1098-1104). However, even high amplitude infraslow activity is difficult to localize by simple visual inspection if there is overlying faster EEG activity or slow artifact. In this study, we address this with improved DC-coupled EEG recording and analysis techniques and also extend observation to both temporal and extratemporal seizures. Recordings were performed during presurgical evaluation of medically intractable epilepsy, with 20 seizures in 11 patients analyzed. A commercial DC-coupled recording device was used, with sintered Ag/AgCl electrodes in a standard 10-10 system array, with additional anterior temporal and subtemporal electrodes. Seizures were localized with a software package by means of source montage analysis. Infraslow signals occurred with all seizures, often with amplitude orders of magnitude higher than conventional frequencies (0.5 to 70 Hz). The most reliable method to localize these signals and distinguish them from artifacts used a source montage after low-pass filtering below 0.5 Hz. Five of the eight patients who received epilepsy surgery had follow-up documenting significant seizure reduction, and infraslow signal analysis correctly localized the region of seizure onset in all five, while conventional noninvasive EEG recording and analysis localized only three of the five. Several seizures were also analyzed using principle component analysis source localization methods, with the results less consistently localizing than source montage analysis. DC-coupled EEG recordings give clinically useful information to noninvasively localize the seizure focus. The value of this method is increased by source analysis tools that reveal localized changes more clearly than direct visual inspection.     

Depressive symptoms in the congenital long QT syndrome

Background. A proportion of patients with congenital long QT syndrome (LQTS) experience potentially life-threatening cardiac arrhythmias.

Aim. To examine whether depressive symptoms are related to arrhythmic events among symptomatic and asymptomatic LQTS patients, and syncope events among their relatives not carrying the family's LQTS-causing mutation.

Methods. The participants were 569 molecularly defined LQTS mutation carriers and 622 non-carrier relatives from the Finnish LQTS registry. Depressive symptoms were self-rated with a revised version of the Beck Depression Inventory.

Results. LQTS patients with arrhythmic events scored higher on depressive symptoms than those without (P=0.011) or the control group (P=0.005). In addition, in the binary logistic regression analysis including symptomatic and asymptomatic LQTS mutation carriers, depressive symptoms showed an age- and sex-adjusted association of odds ratio (OR) 1.40 (95% confidence interval (CI) 1.12–1.74) with symptomatic status of LQTS. In similar analysis including non-carriers of the LQTS mutation, there was no association between depressive symptoms and history of syncope events OR 1.23 (95% CI 0.99–1.53).

Conclusion. Our results from this relatively large genotyped LQTS patient cohort indicate that depressive symptoms are associated with arrhythmic events in LQTS patients. Whether depressive symptoms are causally related to arrhythmias in LQTS remains uncertain.     

Germline variation in TP53 regulatory network genes associates with breast cancer survival and treatment outcome

Germline variation in the TP53 network genes PRKAG2, PPP2R2B, CCNG1, PIAS1 and YWHAQ was previously suggested to have an impact on drug response in vitro. Here, we investigated the effect on breast cancer survival of germline variation in these genes in 925 Finnish breast cancer patients and further analyzed five single nucleotide polymorphisms (SNPs) in PRKAG2 (rs1029946, rs4726050, rs6464153, rs7789699) and PPP2R2B (rs10477313) for 10‐year survival in breast cancer patients, interaction with TP53 R72P and MDM2‐SNP309, outcome after specific adjuvant therapy and correlation to tumor characteristics in 4,701 invasive cases from four data sets. We found evidence for carriers of PRKAG2‐rs1029946 and PRKAG2‐rs4726050 having improved survival in the pooled data (HR 0.53, 95% CI 0.3–0.9; p = 0.023 for homozygous carriers of the rare G‐allele and HR 0.85, 95% CI 0.7–0.9; p = 0.049 for carriers of the rare G allele, respectively). PRKAG2‐rs4726050 showed a significant interaction with MDM2‐SNP309, with PRKAG2‐rs4726050 rare G‐allele having a dose‐dependent effect for better breast cancer survival confined only to MDM2 SNP309 rare G‐allele carriers (HR 0.45, 95% CI 0.2–0.7; p = 0.001). This interaction also emerged as an independent predictor of better survival (p = 0.047). PPP2R2B‐rs10477313 rare A‐allele was found to predict better survival (HR 0.82, 95% CI 0.6–0.9; p = 0.018), especially after hormonal therapy (HR 0.66, 95% CI 0.5–0.9; p = 0.048). These findings warrant further studies and suggest that genetic markers in TP53 network genes such as PRKAG2 and PPP2R2B might affect prognosis and treatment outcome in breast cancer patients.