Unraveling the potential clinical utility of circulating tumor DNA detection in colorectal cancer-evaluation in a nationwide Danish cohort.

BACKGROUND: Increasingly, circulating tumor DNA (ctDNA) is proposed as a tool for minimal residual disease (MRD) assessment. Digital PCR (dPCR) offers low analysis costs and turnaround times of less than a day, making it ripe for clinical implementation. Here, we used tumor-informed dPCR for ctDNA detection in a large colorectal cancer (CRC) cohort to evaluate the potential for post-operative risk assessment and serial monitoring, and how the metastatic site may impact ctDNA detection. Additionally, we assessed how altering the ctDNA-calling algorithm could customize performance for different clinical settings. PATIENTS AND METHODS: Stage II-III CRC patients (N = 851) treated with a curative intent were recruited. Based on whole-exome sequencing on matched tumor and germline DNA, a mutational target was selected for dPCR analysis. Plasma samples (8 ml) were collected within 60 days after operation and-for a patient subset (n = 246)-every 3-4 months for up to 36 months. Single-target dPCR was used for ctDNA detection. RESULTS: Both post-operative and serial ctDNA detection were prognostic of recurrence [hazard ratio (HR) = 11.3, 95% confidence interval (CI) 7.8-16.4, P < 0.001; HR = 30.7, 95% CI 20.2-46.7, P < 0.001], with a cumulative ctDNA detection rate of 87% at the end of sample collection in recurrence patients. The ctDNA growth rate was prognostic of survival (HR = 2.6, 95% CI 1.5-4.4, P = 0.001). In recurrence patients, post-operative ctDNA detection was challenging for lung metastases (4/21 detected) and peritoneal metastases (2/10 detected). By modifying the cut-off for calling a sample ctDNA positive, we were able to adjust the sensitivity and specificity of our test for different clinical contexts. CONCLUSIONS: The presented results from 851 stage II-III CRC patients demonstrate that our personalized dPCR approach effectively detects MRD after operation and shows promise for serial ctDNA detection for recurrence surveillance. The ability to adjust sensitivity and specificity shows exciting potential to customize the ctDNA caller for specific clinical settings.

Cell specific quantitative iron mapping on brain slices by immuno-µPIXE in healthy elderly and Parkinson's disease.

Iron is essential for neurons and glial cells, playing key roles in neurotransmitter synthesis, energy production and myelination. In contrast, high concentrations of free iron can be detrimental and contribute to neurodegeneration, through promotion of oxidative stress. Particularly in Parkinson's disease (PD) changes in iron concentrations in the substantia nigra (SN) was suggested to play a key role in degeneration of dopaminergic neurons in nigrosome 1. However, the cellular iron pathways and the mechanisms of the pathogenic role of iron in PD are not well understood, mainly due to the lack of quantitative analytical techniques for iron quantification with subcellular resolution. Here, we quantified cellular iron concentrations and subcellular iron distributions in dopaminergic neurons and different types of glial cells in the SN both in brains of PD patients and in non-neurodegenerative control brains (Co). To this end, we combined spatially resolved quantitative element mapping using micro particle induced X-ray emission (µPIXE) with nickel-enhanced immunocytochemical detection of cell type-specific antigens allowing to allocate element-related signals to specific cell types. Distinct patterns of iron accumulation were observed across different cell populations. In the control (Co) SNc, oligodendroglial and astroglial cells hold the highest cellular iron concentration whereas in PD, the iron concentration was increased in most cell types in the substantia nigra except for astroglial cells and ferritin-positive oligodendroglial cells. While iron levels in astroglial cells remain unchanged, ferritin in oligodendroglial cells seems to be depleted by almost half in PD. The highest cellular iron levels in neurons were located in the cytoplasm, which might increase the source of non-chelated Fe3+, implicating a critical increase in the labile iron pool. Indeed, neuromelanin is characterised by a significantly higher loading of iron including most probable the occupancy of low-affinity iron binding sites. Quantitative trace element analysis is essential to characterise iron in oxidative processes in PD. The quantification of iron provides deeper insights into changes of cellular iron levels in PD and may contribute to the research in iron-chelating disease-modifying drugs.

Trends in progression-free survival (PFS) and time to progression (TTP) over time within first-line aromatase inhibitors trials in hormone receptor-positive advanced breast cancer.

BACKGROUND: Over the last 20 years, aromatase inhibitors (AI) have been tested in clinical trials as first-line therapy for hormone receptor-positive (HR-positive) advanced breast cancer (ABC), firstly as experimental arms, when they proved to be effective, and recently as control arms. This analysis aims to evaluate trends in progression-free survival (PFS) and time to progression (TTP) over time. PATIENTS AND METHODS: A literature review was conducted using the MEDLINE database to identify randomized controlled phase II or III trials which reported PFS or TTP of at least one arm using first-line AI HR-positive ABC patients. A linear correlation was used to access the association between the year of the first patient enrolled and the observed PFS/TTP. RESULTS: The search retrieved 19 trials, accounting for 4552 postmenopausal patients divided into 21 separate AI treatment arms. The PFS/TTP increased from 6 to 9 months in the earlier trials to 13-16 months in the current era, representing an absolute gain of approximately 7 months, without the addition of any other drug. Our analysis showed a positive correlation between the year of the first patient enrolled in these trials and median PFS/TTP reported (R 2 = 0.34; p < 0.01). No correlation was found between the year of the first patient included in these trials and other potential prognostic factors such as visceral metastasis at baseline (R 2 = 0.26; p = 0.20) or exposure to adjuvant therapy (R 2 = 0.05; p = 0.18). CONCLUSION: Patients treated with first-line AIs in the more recently conducted trials have longer PFS/TTP when compared to their counterparts treated with the same drugs in older studies. These findings have important implications for the estimation of sample size and follow-up periods for the planning of future trials as well as in the translation of the results into clinical practice decisions.

Depolarizing chloride gradient in developing cochlear nucleus neurons: underlying mechanism and implication for calcium signaling.

Precise regulation of the chloride homeostasis crucially determines the action of inhibitory transmitters GABA and glycine and thereby endows neurons or even discrete neuronal compartments with distinct physiological responses to the same transmitters. In mammals, the signaling mediated by GABAA/glycine receptors shifts during early postnatal life from depolarization to hyperpolarization, due to delayed maturation of the chloride homeostasis system. While the activity of the secondary active, K(+)-Cl(-)-extruding cotransporter KCC2, renders GABA/glycine hyperpolarizing in auditory brainstem nuclei of altricial rodents, the mechanisms contributing to the initially depolarizing transmembrane gradient for Cl(-) in respective neurons remained unknown. Here we used gramicidin-perforated patch recordings, non-invasive Cl(-) and Ca(2+) imaging, and immunohistochemistry to identify the Cl(-)-loading transporter that renders depolarizing effects of GABA/glycine in early postnatal life of spherical bushy cells in the cochlear nucleus of gerbil. Our data identify the 1Na(+):1K(+):2Cl(-) cotransporter 1 (NKCC1) as the major Cl(-)-loader responsible for depolarizing action of GABA/glycine at postnatal days 3-5 (P3-5). Extracellular GABA/muscimol elicited calcium signaling through R-, L-, and T-type channels, which was dependent on bumetanide- and [Na(+)]e-sensitive Cl(-) accumulation. The "adult like", low intracellular Cl(-) concentration is established during the second postnatal week, through a mechanism engaging the NKCC1-down regulation between P5 and P15 and ongoing KCC2-mediated Cl(-)-extrusion.

A high resolution genomic portrait of bladder cancer: correlation between genomic aberrations and the DNA damage response.

One major challenge in cancer research is to understand the complex interplay between the DNA damage response (DDR), genomic integrity, and tumor development. To address these issues, we analyzed 43 bladder tumor genomes from 22 patients using single nucleotide polymorphism (SNP) arrays, and tissue expression of multiple DDR proteins, including Timeless and its interaction partner Tipin. The SNP profiles confirmed and extended known copy number alterations (CNAs) at high resolution, showed clustering of CNAs at nine common fragile sites, and revealed that most metachronous tumors were clonally related. The occurrence of many novel uniparental disomy regions (UPDs) was of potential functional importance in some tumors because UPDs spanned mutated FGFR3 and PIK3CA alleles, and also homozygous deletion of the CDKN2A tumor suppressor locus. The DDR signaling as evaluated by phospho-epitope-specific antibodies against Ser139-phosphorylated H2A histone family member X (γH2AX), ataxia telangiectasia mutated (ATM), and ATM- and Rad3-related (ATR) was commonly activated in tumors with both moderate and high extent of accumulated genomic aberrations, the latter tumors showing a more frequent loss of ATM expression. Strikingly, the tumor genomes exhibiting the most complex alterations were associated with a high Ki67-proliferation index, abundant Timeless but not Tipin expression, aberrant p53 expression, and homozygous CDKN2A deletions. Of clinical relevance, evaluation of a tissue microarray (TMA; n=319) showed that abundant Timeless expression was associated with risk of progression to muscle-invasive disease (P<0.0005; hazard ratio, 2.4; 95% confidence interval, 1.6-3.8) and higher T stage (P<0.05). Univariate analysis confirmed this association (P=0.006) in an independent cohort (n=241) but statistical significance was not reached in a multivariate model. Overall, our results are consistent with DDR activation preceding the accumulation of genomic aberrations. Tumors with extensive genomic rearrangements were associated with inactivation of CDKN2A, excessive proliferation, and robust Timeless expression, the latter also correlating with the risk of disease progression. Moreover, we provide evidence to suggest that UPDs likely contribute to bladder tumorigenesis.

Analysis of molecular intra-patient variation and delineation of a prognostic 12-gene signature in non-muscle invasive bladder cancer; technology transfer from microarrays to PCR.

BACKGROUND: Multiple clinical risk factors and genetic profiles have been demonstrated to predict progression of non-muscle invasive bladder cancer; however, no easily clinical applicable gene signature has been developed to predict disease progression independent of disease stage and grade. METHODS: We measured the intra-patient variation of an 88-gene progression signature using 39 metachronous tumours from 17 patients. For delineation of the optimal quantitative reverse transcriptase PCR panel of markers, we used 115 tumour samples from patients in Denmark, Sweden, UK and Spain. RESULTS: Analysis of intra-patient variation of the molecular markers showed 71% similar classification results. A final panel of 12 genes was selected, showing significant correlation with outcome. In multivariate Cox regression analysis, we found that the 12-gene signature was an independent prognostic factor (hazard ratio=7.4 (95% confidence interval: 3.4-15.9), P<0.001) when adjusting for stage, grade and treatment. Independent validation of the 12-gene panel and the determined cut-off values is needed and ongoing. CONCLUSION: Intra-patient marker variation in metachronous tumours is present. Therefore, to increase test sensitivity, it may be necessary to test several metachronous tumours from a patient's disease course. A PCR-based 12-gene signature significantly predicts disease progression in patients with non-muscle invasive bladder cancer.

Expression of MAGE-A3, NY-ESO-1, LAGE-1 and PRAME in urothelial carcinoma.

BACKGROUND: The potential for cancer-testis (CT) antigens as targets for immunotherapy in cancer patients has been heavily investigated, and currently cancer vaccine trials based on the CT antigens, MAGE-A3 and NY-ESO-1, are being carried out. METHODS: We used specific q-RT-PCR assays to analyse the expression of the CT genes MAGE-A3, NY-ESO-1 (CTAG1B), LAGE-1 (CTAG2) and PRAME in a panel of bladder tumours from 350 patients with long-term follow-up and detailed treatment information. RESULTS: Overall, 43% of the tumours expressed MAGE-A3, 35% expressed NY-ESO-1, 27% expressed LAGE-1 and 20% expressed PRAME. In all, 56% of the tumours expressed at least one of the CT genes analysed. Univariate Cox regression analysis of CT gene expression in non-muscle-invasive tumours showed that expression of MAGE-A3 (P=0.026), LAGE-1 (P=0.001) and NY-ESO-1 (P=0.040) was significantly associated with a shorter progression-free survival. In addition, we found that patients with tumours expressing PRAME responded poorly to chemotherapy (P=0.02, χ(2)-test). CONCLUSION: Cancer-testis genes are frequently expressed in bladder cancer and especially in tumours of high stage and grade. In addition, the CT gene expression may have both prognostic and predictive value. Development of specific immunotherapy against the CT antigens in bladder cancer may ultimately increase patient survival.

Cell analysis with the new Leipzig high-energy ion nanoprobe.

The high-energy ion nanoprobe LIPSION at the University of Leipzig has been in operation since 1998. The ultrastable, 3.5 MV SINLETRON accelerator supplies the H+ or He+ ion beam. A magnetic scanning system moves the focused beam across the sample. At present, a resolution of 41 +/- 4 nm in the low current mode and 300 nm at 5 pA can be achieved. The experimental chamber is equipped with electron-, energy dispersive X-ray-, and particle detectors. They can be used simultaneously to analyse the sample by means of PIXE (particle induced X-ray emission), RBS (Rutherford backscattering), and in the case of thin sections or monolayer samples STIM (scanning transmission ion microscopy). A goniometer allows the application of channeling measurements in single crystals in combination with these methods. In contrast to previous publication describing microbeam facility at LIPSION, the current biomedical research has concentrated on microscopy and tomography on chondrocytes in pig cartilages and fixed single endothelial cells (HUVEC). For the irradiation of single living cells, an external beam facility with irradiation platform, fast beamgate and mini-Petri dishes is under construction.

[Need for a substance abuse medicine qualified acute inpatient treatment program in alcohol dependence]. / Uber die Notwendigkeit einer suchtmedizinisch qualifizierten stationären Akutbehandlung bei Alkoholabhängigkeit.

Based on the fact that alcoholism is a mainly psychiatric/psychotherapeutic problem, qualified treatment regimens for the detoxification of addicts have been established at different places. However, a standard treatment hasn't emerged yet, neither for clinical application nor as a basis for discussion between health insurances and clinics. The following article describes essential quality criteria of a qualified acute treatment regimen for addicts. We use existing models and our own experiences of two clinics for the treatment of substances abuse with between 1300 and 1500 admissions each per year.