Disease modifying effects of the amyloid-beta protofibril-selective antibody mAb158 in aged Tg2576 transgenic mice.

Amyloid beta (Aß) peptides, which aggregate to form neocortical plaques in Alzheimer's disease, exist in states that range from soluble monomers and oligomers/protofibrils to insoluble fibrillar amyloid. The present study evaluated the effects of mAb158, a mouse monoclonal antibody version of lecanemab that preferentially binds to soluble Aß protofibrils, in aged transgenic mice (Tg2576) with Aß pathology. Female Tg2576 mice (12 months old) received weekly intraperitoneal mAb158 (35 mg/kg) or vehicle for 4 weeks or for 18 weeks, with or without a subsequent 12-week off-treatment period. Aß protofibril levels were significantly lower in mAb158-treated animals at both 4 and 18 weeks, while longer treatment duration (18 weeks) was required to observe significantly lower Aß42 levels in insoluble brain fractions and lower Aß plaque load. Following the off-treatment period, comparison of the vehicle- and mAb158-treated mice demonstrated that the Aß protofibril levels, insoluble Aß42 levels and Aß plaque load remained significantly lower in mAb158-treated animals, as compared with age-matched controls. However, there was a significant increase of brain accumulation of both the Aß protofibril levels, insoluble Aß42 levels and Aß plaque load after treatment cessation. Thus, repeated mAb158 treatment of aged Tg2576 mice first reduced Aß protofibril levels within 4 weeks of treatment, which then was followed by a reduction of amyloid plaque pathology within 18 weeks of treatment. These effects were maintained 12 weeks after the final dose, indicating that mAb158 had a disease-modifying effect on the Aß pathology in this mouse model. In addition, brain accumulation of both Aß protofibril levels and amyloid pathology progressed after discontinuation of the treatment which supports the importance of continued treatment with mAb158 to maintain the effects on Aß pathology.

Challenging conventional karyotyping by next-generation karyotyping in 281 intensively treated patients with AML.

Although copy number alterations (CNAs) and translocations constitute the backbone of the diagnosis and prognostication of acute myeloid leukemia (AML), techniques used for their assessment in routine diagnostics have not been reconsidered for decades. We used a combination of 2 next-generation sequencing-based techniques to challenge the currently recommended conventional cytogenetic analysis (CCA), comparing the approaches in a series of 281 intensively treated patients with AML. Shallow whole-genome sequencing (sWGS) outperformed CCA in detecting European Leukemia Net (ELN)-defining CNAs and showed that CCA overestimated monosomies and suboptimally reported karyotype complexity. Still, the concordance between CCA and sWGS for all ELN CNA-related criteria was 94%. Moreover, using in silico dilution, we showed that 1 million reads per patient would be enough to accurately assess ELN-defining CNAs. Total genomic loss, defined as a total loss ≥200 Mb by sWGS, was found to be a better marker for genetic complexity and poor prognosis compared with the CCA-based definition of complex karyotype. For fusion detection, the concordance between CCA and whole-transcriptome sequencing (WTS) was 99%. WTS had better sensitivity in identifying inv(16) and KMT2A rearrangements while showing limitations in detecting lowly expressed PML-RARA fusions. Ligation-dependent reverse transcription polymerase chain reaction was used for validation and was shown to be a fast and reliable method for fusion detection. We conclude that a next-generation sequencing-based approach can replace conventional CCA for karyotyping, provided that efforts are made to cover lowly expressed fusion transcripts.

Integrated transcriptomic and genomic analysis improves prediction of complete remission and survival in elderly patients with acute myeloid leukemia.

Relevant molecular tools for treatment stratification of patients ≥65 years with acute myeloid leukemia (AML) are lacking. We combined clinical data with targeted DNA- and full RNA-sequencing of 182 intensively and palliatively treated patients to predict complete remission (CR) and survival in AML patients ≥65 years. Intensively treated patients with NPM1 and IDH2R172 mutations had longer overall survival (OS), whereas mutated TP53 conferred lower CR rates and shorter OS. FLT3-ITD and TP53 mutations predicted worse OS in palliatively treated patients. Gene expression levels most predictive of CR were combined with somatic mutations for an integrated risk stratification that we externally validated using the beatAML cohort. We defined a high-risk group with a CR rate of 20% in patients with mutated TP53, compared to 97% CR in low-risk patients defined by high expression of ZBTB7A and EEPD1 without TP53 mutations. Patients without these criteria had a CR rate of 54% (intermediate risk). The difference in CR rates translated into significant OS differences that outperformed ELN stratification for OS prediction. The results suggest that an integrated molecular risk stratification can improve prediction of CR and OS and could be used to guide treatment in elderly AML patients.

Metabolic profiling of epithelial ovarian cancer cell lines: evaluation of harvesting protocols for profiling using NMR spectroscopy.

BACKGROUND: Metabolic profiling represents a novel technology for analyzing tumor cells. Epithelial ovarian carcinoma has a low survival rate due to the development of aggressive and chemotherapy-resistant cells. A tailored and reliable protocol is presented for profiling of chemoresistant cells using the cell line SKOV3 and a multiresistant subline SKOV3R. RESULTS: Harvesting protocols with cold methanol or MilliQ freeze/thaw cycles were compared. Increased reproducibility using MilliQ was evidenced. Importantly, both approaches resulted in similar profiles. Compared with parental SKOV3, the SKOV3R cells showed a significantly different profile. CONCLUSION: The MilliQ protocol is preferred owing to higher reproducibility and increased sample preparation options. The resulting metabolic profiles summarize metabolic alterations in chemoresistant cells consistent with a progressed and aggressive phenotype.

Expression of mitochondrial regulators PGC1α and TFAM as putative markers of subtype and chemoresistance in epithelial ovarian carcinoma.

Epithelial ovarian carcinoma (EOC), the major cause of gynaecological cancer death, is a heterogeneous disease classified into five subtypes. Each subtype has distinct clinical characteristics and is associated with different genetic risk factors and molecular events, but all are treated with surgery and platinum/taxane regimes. Tumour progression and chemoresistance is generally associated with major metabolic alterations, notably altered mitochondrial function(s). Here, we report for the first time that the expression of the mitochondrial regulators PGC1α and TFAM varies between EOC subtypes; furthermore, we have identified a profile in clear-cell carcinoma consisting of undetectability of PGC1α/TFAM, and low ERα/Ki-67. By contrast, high-grade serous carcinomas were characterised by a converse state of PGC1α/TFAM, ERα positivity and a high Ki-67 index. Interestingly, loss of PGC1α/TFAM and ERα was found also in a non-clear cell EOC cell line made highly resistant to platinum in vitro. Similar to clear-cell carcinomas, these resistant cells also showed accumulation of glycogen. Altogether, our data provide mechanistic insights into the chemoresistant nature of ovarian clear-cell carcinomas. Furthermore, these findings corroborate the need to take into account the diversity of EOC and to develop subtype specific treatment strategies.

Resveratrol induces SIRT1- and energy-stress-independent inhibition of tumor cell regrowth after low-dose platinum treatment.

PURPOSE: To investigate resveratrol (RSV) as a calorie restriction (CR) mimetic potentiator of platinum-based cancer drugs. METHODS: In ovarian carcinoma cell lines, the potentiating effects of RSV were assessed in sulforhodamine B-based growth assays and clonogenic assays. Flow cytometry was used to detect cell cycle effects, siRNA transfections for determining the involvement of SIRT1, and Western blotting for the assessment of altered protein expression and of autophagy. Intracellular ATP levels were detected with a commercial kit. RESULTS: Single-dose RSV co-treatment with cisplatin or carboplatin at inefficiently low doses had the clinically interesting effect of preventing regrowth of cancer cells after drug withdrawal. Of three cell lines tested, metastatic cells with low bioenergetic cellular index (i.e., more glycolytic) were particularly sensitive to combination treatment leading to PUMA induction, acute apoptosis, and autophagy. However, inhibition of regrowth and complete loss of clonogenicity was seen also without these events, in other cells. The underlying mechanism(s) was independent of effects reported to underlie the CR-mimetic cancer-preventive potential of RSV. Thus, SIRT1, estrogen receptors, AMPK activation or upregulation of mitobiogenesis, ß-F(1)-ATPase or PTEN were not involved, and ATP levels did not decrease. CONCLUSIONS: RSV is an excellent candidate for potentiation of platinum treatment, rather than a cancer therapeutic drug in its own right. While SIRT1-dependent and lifespan-promoting effects of RSV are well-documented and may dominate in normal cells, the observed potentiation of platinum drugs does not require these mechanisms. We suggest that the responses of cancer cells to RSV differ greatly from those of normal cells.