Gliomas are tumours arising mostly from astrocytic or oligodendrocytic precursor cells. These tumours are classified according to the updated WHO classification from 2021 in 4 grades depending on ...molecular and histopathological criteria. Despite novel multimodal therapeutic approaches, the vast majority of gliomas (WHO grade III and IV) are not curable. The circadian clock is an important regulator of numerous cellular processes and its dysregulation had been found during the progression of many cancers, including gliomas.
In this study, we explore expression patterns of clock-controlled genes in low-grade glioma (LGG) and glioblastoma multiforme (GBM) and show that a set of 45 clock-controlled genes can be used to distinguish GBM from normal tissue. Subsequent analysis identified 17 clock-controlled genes with a significant association with survival. The results point to a loss of correlation strength within elements of the circadian clock network in GBM compared to LGG. We further explored the progression patterns of mutations in LGG and GBM, and showed that tumour suppressor APC is lost late both in LGG and GBM. Moreover, HIF1A, involved in cellular response to hypoxia, exhibits subclonal losses in LGG, and TERT, involved in the formation of telomerase, is lost late in the GBM progression. By examining multi-sample LGG data, we find that the clock-controlled driver genes APC, HIF1A, TERT and TP53 experience frequent subclonal gains and losses.
Our results show a higher level of disrgulation at the gene expression level in GBM compared to LGG, and indicate an association between the differentially expressed clock-regulated genes and patient survival in both LGG and GBM. By reconstructing the patterns of progression in LGG and GBM, our data reveals the relatively late gains and losses of clock-regulated glioma drivers. Our analysis emphasizes the role of clock-regulated genes in glioma development and progression. Yet, further research is needed to asses their value in the development of new treatments.
Aneuploidy, chromosomal instability, somatic copy-number alterations, and whole-genome doubling (WGD) play key roles in cancer evolution and provide information for the complex task of phylogenetic ...inference. We present MEDICC2, a method for inferring evolutionary trees and WGD using haplotype-specific somatic copy-number alterations from single-cell or bulk data. MEDICC2 eschews simplifications such as the infinite sites assumption, allowing multiple mutations and parallel evolution, and does not treat adjacent loci as independent, allowing overlapping copy-number events. Using simulations and multiple data types from 2780 tumors, we use MEDICC2 to demonstrate accurate inference of phylogenies, clonal and subclonal WGD, and ancestral copy-number states.
Bladder cancer (BC) is the most common malignant disease of the urinary tract. Recurrent high grade non muscle invasive BC carries a serious risk for progression and subsequent metastases. The most ...common preclinical mouse model for bladder cancer relies on administration of N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) to mice. BBN-induced tumors in mice recapitulate the histology of human BC and were characterized with an overexpression of markers typical for basal-like cancer subtype in addition to a high mutational burden with frequent mutations in Trp53, similar to human muscle invasive BC.
Bladder cancer was induced in C57BL/6J male mice by administering the BBN in the drinking water. A thorough histopathological analysis of bladder specimen during and post BBN treatment was performed at 2, 4, 16, 20 and 25 weeks. RNA sequencing and qPCR was performed to assess the levels of expression of immunologically relevant genes at 2 weeks and 20 weeks during and post BBN treatment.
We characterized the dynamics of the inflammatory response in the BBN-induced BC in mice. The treatment with BBN had gradually induced a robust inflammation in the first 2 weeks of administration, however, the inflammatory response was progressively silenced in the following weeks of the treatment, until the progression of the primary carcinoma. Tumors at 20 weeks were characterized with a marked upregulation of IL18 when compared to premalignant inflammatory response at 2 weeks. In accordance with this, we observed an increase in expression of IFNγ-responsive genes coupled to a pronounced lymphocytic infiltrate during the early stages of malignant transformation in bladder. Similar to human basal-like BC, BBN-induced murine tumors displayed an upregulated expression of immunoinhibitory molecules such as CTLA-4, PD-L1, and IDO1 which can lead to cytotoxic resistance and tumor escape.
Despite the recent advances in bladder cancer therapy which include the use of checkpoint inhibitors, the treatment options for patients with locally advanced and metastatic BC remain limited. BBN-induced BC in mice displays an immunological profile which shares similarities with human MIBC thus representing an optimal model for preclinical studies on immunomodulation in management of BC.
Circadian rhythms regulate various processes in the human body, including drug metabolism. Chronotherapy optimizes treatment timing based on the circadian rhythm of the individual patient, such that ...the treatment efficacy is maximized, and adverse effects are minimized. It has been explored in different cancers with varying conclusions. Glioblastoma multiforme (GBM) is the most aggressive type of brain tumour with a very dismal prognosis. In recent years, there has been very little success in designing successful therapies to fight this disease. Chronotherapy offers the opportunity to leverage existing treatments to extend patient survival and to increase their quality of life. Here, we discuss recent advances in using chronotherapy regimens in the treatment of GMB, such as radiotherapy, temozolomide (TMZ) and bortezomib, as well as discuss novel treatments with drugs of short half-life or circadian phase specific activity, and examine the therapeutic potential of new approaches that target elements of the core circadian clock.
Intratumor heterogeneity reflects an ongoing evolution among cells of a single tumor. It is one of the leading causes of drug resistance in cancer treatments. Therefore, to address this issue, it is ...important to understand and successfully model tumor evolution within a single patient.Previous work has failed to successfully address the evolution of tumors whose drivers are structural changes in the genome, such as somatic copy number alterations (SCNAs). This work addresses the challenge of characterizing tumor evolution as a result of such changes.We use a phylogenetic approach to analyze multiregion datasets in a large pancancer cohort. We investigate frequent SCNAs at different stages of tumor development, and introduce a new method, MEDICC2, which reconstructs tumor evolution within a single patient.In this work, we characterized frequent SCNAs that occur early in tumor development. Due to the structure of the cohort, the characterization of subclonal SCNAs remains inconclusive. Our new method, MEDICC2, accepts higher copy number states and takes into account wholegenome doubling, a frequent event in tumors, which allows for a more precise modeling of tumor evolution.
Chromosomal instability in cancer consists of dynamic changes to the number and structure of chromosomes
. The resulting diversity in somatic copy number alterations (SCNAs) may provide the variation ...necessary for tumour evolution
. Here we use multi-sample phasing and SCNA analysis of 1,421 samples from 394 tumours across 22 tumour types to show that continuous chromosomal instability results in pervasive SCNA heterogeneity. Parallel evolutionary events, which cause disruption in the same genes (such as BCL9, MCL1, ARNT (also known as HIF1B), TERT and MYC) within separate subclones, were present in 37% of tumours. Most recurrent losses probably occurred before whole-genome doubling, that was found as a clonal event in 49% of tumours. However, loss of heterozygosity at the human leukocyte antigen (HLA) locus and loss of chromosome 8p to a single haploid copy recurred at substantial subclonal frequencies, even in tumours with whole-genome doubling, indicating ongoing karyotype remodelling. Focal amplifications that affected chromosomes 1q21 (which encompasses BCL9, MCL1 and ARNT), 5p15.33 (TERT), 11q13.3 (CCND1), 19q12 (CCNE1) and 8q24.1 (MYC) were frequently subclonal yet appeared to be clonal within single samples. Analysis of an independent series of 1,024 metastatic samples revealed that 13 focal SCNAs were enriched in metastatic samples, including gains in chromosome 8q24.1 (encompassing MYC) in clear cell renal cell carcinoma and chromosome 11q13.3 (encompassing CCND1) in HER2
breast cancer. Chromosomal instability may enable the continuous selection of SCNAs, which are established as ordered events that often occur in parallel, throughout tumour evolution.
In an experimental design involving two auditorily presented competing commands (one to each ear), 144 right-handed subjects (72 male and 72 female) were asked to provide motor responses. Half of ...each group of subjects was responding with their right hand and the other half with the left. The test was applied in the subjects’ native language (Croatian) and in English, which they had learned as a foreign language. Ear advantage was determined by calculating laterality indices from the order of responding to the commands. On average, right-ear advantage was found in all conditions. Analysis of results revealed the effect of the active hand in Croatian (with significant decrease in the right-ear advantage when using the left hand). The same trend failed to reach significance in English. In responses to English stimuli, there was a significant effect of gender (with men exhibiting a lower right-ear advantage than women). The same trend was not significant for Croatian stimuli. The consistently lower right-ear advantage found in male subjects is contrary to the traditional assumptions that men are more lateralized than women and warrants further investigation.
Gutmann Acceptor Number (AN) values have been determined for Brønsted acid-ionic liquid mixtures, over a wide compositional range. Four systems of general formula C2mimA-HA (A(-) = bistriflamide, ...NTf2(-); triflate, OTf(-); mesylate, OMs(-); or acetate, OAc(-), C2mim(+) = 1-ethyl-3-methylimidazolium cation) were studied. A library of Brønsted acidic systems of varying acidity was constructed and the AN parameter was found to be a convenient approach for quantifying their acidity. HOAc, HOMs and HOTf, when dissolved in ionic liquids, were found to associate with the respective anions to form hydrogen-bonded anionic clusters, A(HA)x(-). In contrast, HNTf2 was solubilised as a discrete, undissociated molecule. AN values were sensitive to the presence of anionic clusters; acidity could be buffered to a particular AN by binding the solubilised acid in the anionic cluster form. Overall, a simple way to manipulate and quantify the Brønsted acidity of acid-ionic liquid mixtures was demonstrated, and measured AN values were related to liquid speciation.
Die Intra-Tumor-Heterogenität spiegelt eine kontinuierliche Entwicklung zwischen den Zellen eines einzelnen Tumors wider. Sie ist eine der Hauptursachen für Arzneimittelresistenz bei der ...Krebsbehandlung. Um dieses Problem anzugehen, ist es daher wichtig, die Tumorevolution innerhalb eines einzelnen Patienten zu verstehen und erfolgreich zu modellieren. ;
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Bisherige Arbeiten haben sich nicht erfolgreich mit der Evolution von Tumoren befasst, deren Treiber strukturelle Veränderungen im Genom sind, wie z. B. somatische Kopienzahlveränderungen (SCNAs). Diese Arbeit befasst sich mit der Herausforderung, die Tumorevolution als Folge solcher Veränderungen zu charakterisieren. ;
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Wir verwenden einen phylogenetischen Ansatz zur Analyse von multiregionalen Datensätzen in einer großen Pan-Krebs-Kohorte. Wir untersuchen häufige SCNAs in verschiedenen Stadien der Tumorentwicklung und führen eine neue Methode, MEDICC2, ein, die die Tumorevolution innerhalb eines einzelnen Patienten rekonstruiert. ;
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In dieser Arbeit haben wir häufige SCNAs charakterisiert, die früh in der Tumorentwicklung auftreten. Aufgrund der Struktur der Kohorte ist die Charakterisierung der subklonalen SCNAs nicht eindeutig. Unsere neue Methode, MEDICC2, akzeptiert höhere Kopienzahlzustände und berücksichtigt die Verdopplung des gesamten Genoms, ein häufiges Ereignis in Tumoren, was eine genauere Modellierung der Tumorevolution ermöglicht.
Intra-tumor heterogeneity reflects an ongoing evolution among cells of a single tumor. It is one of the leading causes of drug resistance in cancer treatments. Therefore, to address this issue, it is important to understand and successfully model tumor evolution within a single patient. ;
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Previous work has failed to successfully address the evolution of tumors whose drivers are structural changes in the genome, such as somatic copy number alterations (SCNAs). This work addresses the challenge of characterizing tumor evolution as a result of such changes. ;
;
We use a phylogenetic approach to analyze multi-region datasets in a large pan-cancer cohort. We investigate frequent SCNAs at different stages of tumor development, and introduce a new method, MEDICC2, which reconstructs tumor evolution within a single patient. ;
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In this work, we characterized frequent SCNAs that occur early in tumor development. Due to the structure of the cohort, the characterization of subclonal SCNAs remains inconclusive. Our new method, MEDICC2, accepts higher copy number states and takes into account whole-genome doubling, a frequent event in tumors, which allows for a more precise modeling of tumor evolution.
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