195 results on '"Ivana Bozic"'
Search Results
2. Successful Desensitization to Sorafenib and Imatinib—A Report of Two Cases and a Literature Review
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Natasa Kusic, Vesna Tomic Spiric, Snezana Arandjelovic, Aleksandra Peric Popadic, Ivana Bozic Antic, Milan Dimitrijevic, Rada Miskovic, Ljiljana Stefanovic, and Aleksandra Plavsic
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desensitization ,drug hypersensitivity reaction ,imatinib ,sorafenib ,Medicine - Abstract
Background: Drug desensitization allows for safe administration of a drug to a patient with a previous hypersensitivity reaction. Successful desensitization protocols have been described for different medications, including protocols for oncology patients. Few cases of desensitization to sorafenib and imatinib have been described in the literature so far. Objective: The objective of this paper is to describe the process of the sorafenib and imatinib drug hypersensitivity diagnosis and desensitization process in two patients. Methods: Two oncology patients who experienced non-immediate hypersensitivity reactions to sorafenib and imatinib underwent desensitization to these drugs. We designed a protocol for the first patient and used a modified protocol from the literature for the second patient. Results: By using a slow desensitization technique and gradual tapering of corticosteroids and antihistamines, both patients reached the target dose of the incriminated drug. Conclusions: Desensitization to sorafenib and imatinib can be an effective therapeutic option in patients with hypersensitivity to those medications, without alternative treatment options.
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- 2024
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3. Ultra-deep mutational landscape in chronic lymphocytic leukemia uncovers dynamics of resistance to targeted therapies
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David W. Woolston, Nathan D. Lee, Mazyar Shadman, Elena Latorre-Esteves, Xin Ray Tee, Jeanne Fredrickson, Brendan F. Kohrn, Chaitra Ujjani, Ashley Eckel, Brian Till, Min Fang, Jerald Radich, Ivana Bozic, Rosa Ana Risques, and Cecilia C.S. Yeung
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Diseases of the blood and blood-forming organs ,RC633-647.5 - Abstract
BTK inhibitors, Bcl-2 inhibitors, and other targeted therapies have significantly improved the outcomes of patients with chronic lymphocytic leukemia (CLL). With increased survivorship, monitoring disease and deciphering potential mechanisms of resistance to these agents are critical for devising effective treatment strategies. We used duplex sequencing, a technology that enables detection of mutations at ultra-low allelic frequencies, to identify mutations in five genes associated with drug resistance in CLL and followed their evolution in two patients who received multiple targeted therapies and ultimately developed disease progression on pirtobrutinib. In both patients we detected variants that expanded and reached significant cancer cell fractions (CCF). In patient R001, multiple known resistance mutations in both BTK and PLCG2 appeared following progression on zanubrutinib (BTK p.L528W, p.C481S; PLCG2 S707F, L845F, R665W, and D993H). In contrast, patient R002 developed multiple BTK mutations following acalabrutinib treatment, including known resistance mutations p.C481R, p.T474I and p.C481S. We found that pirtobrutinib was able to suppress, but not completely eradicate, BTK p.C481S mutations in both patients, but other resistance mutations such as mutations in PLCG2 and new BTK mutations increased while the patients were receiving pirtobrutinib. For example, BTK p.L528W in patient R001 increased in frequency more than 1,000-fold (from a CCF of 0.02% to 35%), and the CCF in p.T474I in patient R002 increased from 0.03% to 4.2% (more than 100-fold). Our data illuminate the evolutionary dynamics of resistant clones over the patients’ disease course and under selective pressure from different targeted treatments.
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- 2023
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4. Inferring parameters of cancer evolution in chronic lymphocytic leukemia.
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Nathan D Lee and Ivana Bozic
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Biology (General) ,QH301-705.5 - Abstract
As a cancer develops, its cells accrue new mutations, resulting in a heterogeneous, complex genomic profile. We make use of this heterogeneity to derive simple, analytic estimates of parameters driving carcinogenesis and reconstruct the timeline of selective events following initiation of an individual cancer, where two longitudinal samples are available for sequencing. Using stochastic computer simulations of cancer growth, we show that we can accurately estimate mutation rate, time before and after a driver event occurred, and growth rates of both initiated cancer cells and subsequently appearing subclones. We demonstrate that in order to obtain accurate estimates of mutation rate and timing of events, observed mutation counts should be corrected to account for clonal mutations that occurred after the founding of the tumor, as well as sequencing coverage. Chronic lymphocytic leukemia (CLL), which often does not require treatment for years after diagnosis, presents an optimal system to study the untreated, natural evolution of cancer cell populations. When we apply our methodology to reconstruct the individual evolutionary histories of CLL patients, we find that the parental leukemic clone typically appears within the first fifteen years of life.
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- 2022
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5. Estimating the transfer rates of bacterial plasmids with an adapted Luria-Delbrück fluctuation analysis.
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Olivia Kosterlitz, Adamaris Muñiz Tirado, Claire Wate, Clint Elg, Ivana Bozic, Eva M Top, and Benjamin Kerr
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Biology (General) ,QH301-705.5 - Abstract
To increase our basic understanding of the ecology and evolution of conjugative plasmids, we need reliable estimates of their rate of transfer between bacterial cells. Current assays to measure transfer rate are based on deterministic modeling frameworks. However, some cell numbers in these assays can be very small, making estimates that rely on these numbers prone to noise. Here, we take a different approach to estimate plasmid transfer rate, which explicitly embraces this noise. Inspired by the classic fluctuation analysis of Luria and Delbrück, our method is grounded in a stochastic modeling framework. In addition to capturing the random nature of plasmid conjugation, our new methodology, the Luria-Delbrück method ("LDM"), can be used on a diverse set of bacterial systems, including cases for which current approaches are inaccurate. A notable example involves plasmid transfer between different strains or species where the rate that one type of cell donates the plasmid is not equal to the rate at which the other cell type donates. Asymmetry in these rates has the potential to bias or constrain current transfer estimates, thereby limiting our capabilities for estimating transfer in microbial communities. In contrast, the LDM overcomes obstacles of traditional methods by avoiding restrictive assumptions about growth and transfer rates for each population within the assay. Using stochastic simulations and experiments, we show that the LDM has high accuracy and precision for estimation of transfer rates compared to the most widely used methods, which can produce estimates that differ from the LDM estimate by orders of magnitude.
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- 2022
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6. The evolutionary landscape of chronic lymphocytic leukemia treated with ibrutinib targeted therapy
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Dan A. Landau, Clare Sun, Daniel Rosebrock, Sarah E. M. Herman, Joshua Fein, Mariela Sivina, Chingiz Underbayev, Delong Liu, Julia Hoellenriegel, Sarangan Ravichandran, Mohammed Z. H. Farooqui, Wandi Zhang, Carrie Cibulskis, Asaf Zviran, Donna S. Neuberg, Dimitri Livitz, Ivana Bozic, Ignaty Leshchiner, Gad Getz, Jan A. Burger, Adrian Wiestner, and Catherine J. Wu
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Science - Abstract
In a subset of patients with chronic lymphocytic leukemia (CLL) treated with targeted agents, such as ibrutinib, drug resistant subclones emerge. Here, the authors report on transcriptional changes in CLL patients treated with ibrutinib and identify early clonal shifts associated with evolution of resistant clones.
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- 2017
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7. Pharmacogenomics: Recent Progress, Sex Gender Differences, Translation Into Clinical Practice, Application in Pediatrics and Future Perspectives
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Martina Smolic, Ivana Bozic, Tea Omanovic, Lucija Kuna, Tomislav Kizivat, Robert Smolic, and Aleksandar Vcev
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pharmacogenomics ,medicine ,clinical ,pediatrics ,Medicine - Abstract
Pharmacogenomics is a promising field which increasingly influences medicine and biomedical research in many areas. Aim of this article is to provide a comprehensive review of recent progress in the understanding of the genetic polymorphisms and their influence on interindividual variability in drug response. Also, main variabilites in drug response according to sex gender differences will be discussed. Translation of pharmacogenomics into clinical practice and the challenges of reaching the goal of individualized medicine are also discussed. The role of pharmacogenetic tests in pediatrics has not been well defined yet, but it is clear that those tests could help in resolving some issues regarding administration of drugs to children. At the end, main ethical, social and regulatory issues regarding translation of pharmacogenomics into clinical practice and future perspectives in the field will be shown.
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- 2017
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8. Reconstructing metastatic seeding patterns of human cancers
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Johannes G. Reiter, Alvin P. Makohon-Moore, Jeffrey M. Gerold, Ivana Bozic, Krishnendu Chatterjee, Christine A. Iacobuzio-Donahue, Bert Vogelstein, and Martin A. Nowak
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Science - Abstract
Tumours frequently metastasize to multiple anatomical sites and understanding how these different metastases evolve may be important for therapy. Here, the authors develop a method—Treeomics—that can construct phylogenies from multiple metastases from next-generation sequencing data.
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- 2017
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9. On measuring selection in cancer from subclonal mutation frequencies.
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Ivana Bozic, Chay Paterson, and Bartlomiej Waclaw
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Biology (General) ,QH301-705.5 - Abstract
Recently available cancer sequencing data have revealed a complex view of the cancer genome containing a multitude of mutations, including drivers responsible for cancer progression and neutral passengers. Measuring selection in cancer and distinguishing drivers from passengers have important implications for development of novel treatment strategies. It has recently been argued that a third of cancers are evolving neutrally, as their mutational frequency spectrum follows a 1/f power law expected from neutral evolution in a particular intermediate frequency range. We study a stochastic model of cancer evolution and derive a formula for the probability distribution of the cancer cell frequency of a subclonal driver, demonstrating that driver frequency is biased towards 0 and 1. We show that it is difficult to capture a driver mutation at an intermediate frequency, and thus the calling of neutrality due to a lack of such driver will significantly overestimate the number of neutrally evolving tumors. Our approach provides quantification of the validity of the 1/f statistic across the entire range of relevant parameter values. We also show that our conclusions remain valid for non-exponential models: spatial 3d model and sigmoidal growth, relevant for early- and late stages of cancer growth.
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- 2019
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10. Clonal evolution in patients with chronic lymphocytic leukaemia developing resistance to BTK inhibition
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Jan A. Burger, Dan A. Landau, Amaro Taylor-Weiner, Ivana Bozic, Huidan Zhang, Kristopher Sarosiek, Lili Wang, Chip Stewart, Jean Fan, Julia Hoellenriegel, Mariela Sivina, Adrian M. Dubuc, Cameron Fraser, Yulong Han, Shuqiang Li, Kenneth J. Livak, Lihua Zou, Youzhong Wan, Sergej Konoplev, Carrie Sougnez, Jennifer R. Brown, Lynne V. Abruzzo, Scott L. Carter, Michael J. Keating, Matthew S. Davids, William G. Wierda, Kristian Cibulskis, Thorsten Zenz, Lillian Werner, Paola Dal Cin, Peter Kharchencko, Donna Neuberg, Hagop Kantarjian, Eric Lander, Stacey Gabriel, Susan O’Brien, Anthony Letai, David A. Weitz, Martin A. Nowak, Gad Getz, and Catherine J. Wu
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Science - Abstract
The BTK inhibitor ibrutinib is used to treat chronic lymphocytic leukaemia, however some patients develop resistance to the drug. Here, the authors use genomic analyses to examine the clonal evolution of 5 patients that develop resistance to ibrutinib.
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- 2016
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11. The (not so) immortal strand hypothesis
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Cristian Tomasetti and Ivana Bozic
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Biology (General) ,QH301-705.5 - Abstract
Background: Non-random segregation of DNA strands during stem cell replication has been proposed as a mechanism to minimize accumulated genetic errors in stem cells of rapidly dividing tissues. According to this hypothesis, an “immortal” DNA strand is passed to the stem cell daughter and not the more differentiated cell, keeping the stem cell lineage replication error-free. After it was introduced, experimental evidence both in favor and against the hypothesis has been presented. Principal findings: Using a novel methodology that utilizes cancer sequencing data we are able to estimate the rate of accumulation of mutations in healthy stem cells of the colon, blood and head and neck tissues. We find that in these tissues mutations in stem cells accumulate at rates strikingly similar to those expected without the protection from the immortal strand mechanism. Significance: Utilizing an approach that is fundamentally different from previous efforts to confirm or refute the immortal strand hypothesis, we provide evidence against non-random segregation of DNA during stem cell replication. Our results strongly suggest that parental DNA is passed randomly to stem cell daughters and provides new insight into the mechanism of DNA replication in stem cells.
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- 2015
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12. Quantifying Clonal and Subclonal Passenger Mutations in Cancer Evolution.
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Ivana Bozic, Jeffrey M Gerold, and Martin A Nowak
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Biology (General) ,QH301-705.5 - Abstract
The vast majority of mutations in the exome of cancer cells are passengers, which do not affect the reproductive rate of the cell. Passengers can provide important information about the evolutionary history of an individual cancer, and serve as a molecular clock. Passengers can also become targets for immunotherapy or confer resistance to treatment. We study the stochastic expansion of a population of cancer cells describing the growth of primary tumors or metastatic lesions. We first analyze the process by looking forward in time and calculate the fixation probabilities and frequencies of successive passenger mutations ordered by their time of appearance. We compute the likelihood of specific evolutionary trees, thereby informing the phylogenetic reconstruction of cancer evolution in individual patients. Next, we derive results looking backward in time: for a given subclonal mutation we estimate the number of cancer cells that were present at the time when that mutation arose. We derive exact formulas for the expected numbers of subclonal mutations of any frequency. Fitting this formula to cancer sequencing data leads to an estimate for the ratio of birth and death rates of cancer cells during the early stages of clonal expansion.
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- 2016
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13. Evolutionary dynamics of cancer in response to targeted combination therapy
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Ivana Bozic, Johannes G Reiter, Benjamin Allen, Tibor Antal, Krishnendu Chatterjee, Preya Shah, Yo Sup Moon, Amin Yaqubie, Nicole Kelly, Dung T Le, Evan J Lipson, Paul B Chapman, Luis A Diaz Jr, Bert Vogelstein, and Martin A Nowak
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mathematical biology ,cancer ,stochastic process ,targeted therapy ,genetic ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
In solid tumors, targeted treatments can lead to dramatic regressions, but responses are often short-lived because resistant cancer cells arise. The major strategy proposed for overcoming resistance is combination therapy. We present a mathematical model describing the evolutionary dynamics of lesions in response to treatment. We first studied 20 melanoma patients receiving vemurafenib. We then applied our model to an independent set of pancreatic, colorectal, and melanoma cancer patients with metastatic disease. We find that dual therapy results in long-term disease control for most patients, if there are no single mutations that cause cross-resistance to both drugs; in patients with large disease burden, triple therapy is needed. We also find that simultaneous therapy with two drugs is much more effective than sequential therapy. Our results provide realistic expectations for the efficacy of new drug combinations and inform the design of trials for new cancer therapeutics.
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- 2013
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14. Clonal interactions in cancer: Integrating quantitative models with experimental and clinical data
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Nathan D. Lee, Kamran Kaveh, and Ivana Bozic
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Cancer Research - Published
- 2023
15. Waiting times in a branching process model of colorectal cancer initiation
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Ruibo Zhang, Obinna A. Ukogu, and Ivana Bozic
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Ecology, Evolution, Behavior and Systematics - Abstract
We consider a multi-type branching process model for the initiation of colorectal cancer, which progresses through a complex sequence of driver mutations. The model incorporates the relative fitness advantages conferred by driver mutations, which leads us to consider non-dividing sub-populations, and the effects of neutral and advantageous mutations. We analyze large-time limits to approximate the population sizes of sub-clones founded by neutral or advantageous mutations, and use the results to compute the waiting time distributions for the incidence of novel mutations in colorectal cancer initiation. Analytic waiting time distributions, including the distribution of waiting time to malignancy, are in good agreement with results from Monte Carlo simulations of the model. The approach presented here can be extended to other multi-type branching process models where population growth rates of consecutive types are non-decreasing.
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- 2023
16. In VivoModeling of CLL Transformation to Richter Syndrome Reveals Convergent Evolutionary Paths and Therapeutic Vulnerabilities
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Elisa ten Hacken, Tomasz Sewastianik, Shanye Yin, Gabriela Brunsting Hoffmann, Michaela Gruber, Kendell Clement, Livius Penter, Robert A. Redd, Neil Ruthen, Sébastien Hergalant, Alanna Sholokhova, Geoffrey Fell, Erin M. Parry, Julien Broséus, Romain Guieze, Fabienne Lucas, María Hernández-Sánchez, Kaitlyn Baranowski, Jackson Southard, Heather Joyal, Leah Billington, Fara Faye D. Regis, Elizabeth Witten, Mohamed Uduman, Binyamin A. Knisbacher, Shuqiang Li, Haoxiang Lyu, Tiziana Vaisitti, Silvia Deaglio, Giorgio Inghirami, Pierre Feugier, Stephan Stilgenbauer, Eugen Tausch, Matthew S. Davids, Gad Getz, Kenneth J. Livak, Ivana Bozic, Donna S. Neuberg, Ruben D. Carrasco, and Catherine J. Wu
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General Medicine - Abstract
Transformation to aggressive disease histologies generates formidable clinical challenges across cancers, but biological insights remain few. We modeled the genetic heterogeneity of chronic lymphocytic leukemia (CLL) through multiplexed in vivo CRISPR-Cas9 B-cell editing of recurrent CLL loss-of-function drivers in mice and recapitulated the process of transformation from indolent CLL into large cell lymphoma [i.e., Richter syndrome (RS)]. Evolutionary trajectories of 64 mice carrying diverse combinatorial gene assortments revealed coselection of mutations in Trp53, Mga, and Chd2 and the dual impact of clonal Mga/Chd2 mutations on E2F/MYC and interferon signaling dysregulation. Comparative human and murine RS analyses demonstrated tonic PI3K signaling as a key feature of transformed disease, with constitutive activation of the AKT and S6 kinases, downmodulation of the PTEN phosphatase, and convergent activation of MYC/PI3K transcriptional programs underlying enhanced sensitivity to MYC/mTOR/PI3K inhibition. This robust experimental system presents a unique framework to study lymphoid biology and therapy.Significance:Mouse models reflective of the genetic complexity and heterogeneity of human tumors remain few, including those able to recapitulate transformation to aggressive disease histologies. Herein, we model CLL transformation into RS through multiplexed in vivo gene editing, providing key insight into the pathophysiology and therapeutic vulnerabilities of transformed disease.This article is highlighted in the In This Issue feature, p. 101
- Published
- 2022
17. Data from In Vivo Modeling of CLL Transformation to Richter Syndrome Reveals Convergent Evolutionary Paths and Therapeutic Vulnerabilities
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Catherine J. Wu, Ruben D. Carrasco, Donna S. Neuberg, Ivana Bozic, Kenneth J. Livak, Gad Getz, Matthew S. Davids, Eugen Tausch, Stephan Stilgenbauer, Pierre Feugier, Giorgio Inghirami, Silvia Deaglio, Tiziana Vaisitti, Haoxiang Lyu, Shuqiang Li, Binyamin A. Knisbacher, Mohamed Uduman, Elizabeth Witten, Fara Faye D. Regis, Leah Billington, Heather Joyal, Jackson Southard, Kaitlyn Baranowski, María Hernández-Sánchez, Fabienne Lucas, Romain Guieze, Julien Broséus, Erin M. Parry, Geoffrey Fell, Alanna Sholokhova, Sébastien Hergalant, Neil Ruthen, Robert A. Redd, Livius Penter, Kendell Clement, Michaela Gruber, Gabriela Brunsting Hoffmann, Shanye Yin, Tomasz Sewastianik, and Elisa ten Hacken
- Abstract
Transformation to aggressive disease histologies generates formidable clinical challenges across cancers, but biological insights remain few. We modeled the genetic heterogeneity of chronic lymphocytic leukemia (CLL) through multiplexed in vivo CRISPR-Cas9 B-cell editing of recurrent CLL loss-of-function drivers in mice and recapitulated the process of transformation from indolent CLL into large cell lymphoma [i.e., Richter syndrome (RS)]. Evolutionary trajectories of 64 mice carrying diverse combinatorial gene assortments revealed coselection of mutations in Trp53, Mga, and Chd2 and the dual impact of clonal Mga/Chd2 mutations on E2F/MYC and interferon signaling dysregulation. Comparative human and murine RS analyses demonstrated tonic PI3K signaling as a key feature of transformed disease, with constitutive activation of the AKT and S6 kinases, downmodulation of the PTEN phosphatase, and convergent activation of MYC/PI3K transcriptional programs underlying enhanced sensitivity to MYC/mTOR/PI3K inhibition. This robust experimental system presents a unique framework to study lymphoid biology and therapy.Significance:Mouse models reflective of the genetic complexity and heterogeneity of human tumors remain few, including those able to recapitulate transformation to aggressive disease histologies. Herein, we model CLL transformation into RS through multiplexed in vivo gene editing, providing key insight into the pathophysiology and therapeutic vulnerabilities of transformed disease.This article is highlighted in the In This Issue feature, p. 101
- Published
- 2023
18. Supplementary Figures from In Vivo Modeling of CLL Transformation to Richter Syndrome Reveals Convergent Evolutionary Paths and Therapeutic Vulnerabilities
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Catherine J. Wu, Ruben D. Carrasco, Donna S. Neuberg, Ivana Bozic, Kenneth J. Livak, Gad Getz, Matthew S. Davids, Eugen Tausch, Stephan Stilgenbauer, Pierre Feugier, Giorgio Inghirami, Silvia Deaglio, Tiziana Vaisitti, Haoxiang Lyu, Shuqiang Li, Binyamin A. Knisbacher, Mohamed Uduman, Elizabeth Witten, Fara Faye D. Regis, Leah Billington, Heather Joyal, Jackson Southard, Kaitlyn Baranowski, María Hernández-Sánchez, Fabienne Lucas, Romain Guieze, Julien Broséus, Erin M. Parry, Geoffrey Fell, Alanna Sholokhova, Sébastien Hergalant, Neil Ruthen, Robert A. Redd, Livius Penter, Kendell Clement, Michaela Gruber, Gabriela Brunsting Hoffmann, Shanye Yin, Tomasz Sewastianik, and Elisa ten Hacken
- Abstract
Supplementary file contains a PDF version of supplementary figures S1-S7 and associated figure legends.
- Published
- 2023
19. Supplementary Tables from In Vivo Modeling of CLL Transformation to Richter Syndrome Reveals Convergent Evolutionary Paths and Therapeutic Vulnerabilities
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Catherine J. Wu, Ruben D. Carrasco, Donna S. Neuberg, Ivana Bozic, Kenneth J. Livak, Gad Getz, Matthew S. Davids, Eugen Tausch, Stephan Stilgenbauer, Pierre Feugier, Giorgio Inghirami, Silvia Deaglio, Tiziana Vaisitti, Haoxiang Lyu, Shuqiang Li, Binyamin A. Knisbacher, Mohamed Uduman, Elizabeth Witten, Fara Faye D. Regis, Leah Billington, Heather Joyal, Jackson Southard, Kaitlyn Baranowski, María Hernández-Sánchez, Fabienne Lucas, Romain Guieze, Julien Broséus, Erin M. Parry, Geoffrey Fell, Alanna Sholokhova, Sébastien Hergalant, Neil Ruthen, Robert A. Redd, Livius Penter, Kendell Clement, Michaela Gruber, Gabriela Brunsting Hoffmann, Shanye Yin, Tomasz Sewastianik, and Elisa ten Hacken
- Abstract
Supplementary file contains all supplementary tables S1-S16 in Excel format in the order in which they appear in the text.
- Published
- 2023
20. A simple stochastic model for cell population dynamics in colonic crypts
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Konstantinos Mamis, Ruibo Zhang, and Ivana Bozic
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The questions of how healthy colonic crypts maintain their size, and how homeostasis is disrupted by driver mutations, are central to understanding colorectal tumorigenesis. We propose a three-type stochastic branching process, which accounts for stem, transit-amplifying (TA) and fully differentiated (FD) cells, to model the dynamics of cell populations residing in colonic crypts. Our model is simple in its formulation, allowing us to easily estimate all but one of the model parameters from the literature. Fitting the single remaining parameter, we find that model results agree well with data from healthy human colonic crypts, capturing the considerable variance in population sizes observed experimentally. Importantly, our model predicts a steady state population in healthy colonic crypts for relevant parameter values. We show thatAPCandKRASmutations, the most significant early alterations leading to colorectal cancer, result in increased steady-state populations in mutated crypts, in agreement with experimental results. Finally, our model predicts a simple condition for unbounded growth of cells in a crypt, corresponding to colorectal malignancy. This is predicted to occur when the division rate of TA cells exceeds their differentiation rate, with implications for therapeutic cancer prevention strategies.
- Published
- 2023
21. Knowledge, attitudes and beliefs regarding HIV among medical students in Zagreb, Croatia
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Dominik Ljubas, Hana Škornjak, and Ivana Božičević
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HIV ,PLWHA ,Knowledge ,Attitudes ,Medical students ,Prevention ,Special aspects of education ,LC8-6691 ,Medicine - Abstract
Abstract Background Medical students, as future health-care providers (HCPs) play a significant role in shaping attitudes towards people living with HIV/AIDS (PLWHA) and should possess adequate knowledge of this infection. The study aim was to assess knowledge about HIV among medical students of the University of Zagreb School of Medicine, and to determine the level of discriminatory attitudes towards PLWHA. Methods We assessed knowledge about epidemiology, treatment, and prevention of HIV by using closed-ended and multiple-choice questions. Likert-scale questions were employed to determine attitudes towards PLWHA. Bivariate and multivariate ordinal logistic regression was used to assess correlates of certain discriminatory attitudes. Results 561 medical students participated, with 46.7% attending preclinical courses. Overall, 42.1% of students think they received sufficient information on HIV/AIDS during elementary and high school education. Among clinical students, 42.6%, 20.8% and 11.8% estimated accurately transmission risk after a needle injury, unprotected vaginal, and anal intercourse, respectively. 66.8% of clinical students were aware that treatment can prevent AIDS, while 58.7% and 69.8% were familiar with the rationale of using pre-exposure (PrEP) and post-exposure prophylaxis (PEP). In the multivariate analysis, individuals lacking infectology course attendance (aOR = 1.45; CI: 1.00–2.09) and those unaware of transmission routes (aOR = 1.49; CI: 1.06–2.09) showed higher odds of advocating HIV status disclosure compared to those who did not yet attend an infectology course. Students supporting extra protection for handling PLWHA bodily fluids were more likely to support refusal to treat PLWHA (aOR = 1.80; CI: 1.22–2.69) compared to those who did not support that opinion. Males were more inclined to state that they would refuse to treat PLWHA (aOR = 1.66; CI: 1.11–2.50) and disclose their HIV status (aOR = 1.62; CI: 1.17–2.27) than females. Overestimating needle injury transmission risk raised treatment refusal likelihood (aOR = 2.22; CI = 1.29–3.92) compared to those accurately informed of this risk. Conclusion Results indicate lack of knowledge of HIV transmission risks after specific exposures and about PrEP, PEP and treatment effectiveness. Gender and knowledge about HIV transmission risks influence students’ attitudes towards PLWHA. Medical education should be focused on fostering correct attitudes and addressing stigma, which undermines prevention and treatment outcomes of PLWHA.
- Published
- 2024
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22. TTP: Tool for Tumor Progression.
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Johannes G. Reiter, Ivana Bozic, Krishnendu Chatterjee, and Martin A. Nowak
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- 2013
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23. Overweight and obesity in polycystic ovary syndrome: association with inflammation, oxidative stress and dyslipidaemia
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Djuro P Macut, Biljana Kastratovic-Kotlica, Vesna Spasojevic-Kalimanovska, Svetlana Ignjatović, Jelena Vekic, Ivana Bozic-Antic, Jelena Kotur-Stevuljevic, Iva Perovic Blagojevic, Dusan Ilic, Zoran Andrić, Aleksandra Zeljkovic, Milica M. Miljkovic-Trailovic, and Jelica Bjekic-Macut
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030213 general clinical medicine ,medicine.medical_specialty ,Medicine (miscellaneous) ,030204 cardiovascular system & hematology ,medicine.disease_cause ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Internal medicine ,PCOS ,medicine ,oxidative stress ,Obesity ,2. Zero hunger ,Nutrition and Dietetics ,medicine.diagnostic_test ,biology ,business.industry ,dyslipidemia ,Paraoxonase ,nutritional and metabolic diseases ,medicine.disease ,Malondialdehyde ,Polycystic ovary ,PON1 ,Endocrinology ,chemistry ,inflammation ,biology.protein ,lipids (amino acids, peptides, and proteins) ,Lipid profile ,business ,Dyslipidemia ,Oxidative stress ,Lipoprotein - Abstract
Objective: Polycystic ovary syndrome (PCOS) is associated with altered lipid profile and increased small, dense LDL particles (sdLDL). Considering that paraoxonase 1 (PON1) is an anti-oxidative enzyme located on high-density lipoprotein (HDL) particles, the aim of this study was to investigate the connection between oxidative stress (OS) and PON1 activity with lipoprotein subclasses in PCOS depending on obesity. Methods: In 115 PCOS patients lipoprotein subclasses distributions were determined by gradient gel electrophoresis. OS status was assessed by total oxidative status (TOS), advanced oxidation protein products (AOPP), malondialdehyde (MDA), prooxidant-Antioxidant balance (PAB), total antioxidant status (TAS) and superoxide dismutase (SOD) and PON1 activity. Results: Overweight/obese PCOS patients (n=55) had increased OS compared to normal weight patients (n=60). In addition, overweight/obese group had lower HDL size and higher proportion of HDL 3a subclasses (P
- Published
- 2021
24. Predictive Vaccinology: Optimisation of Predictions Using Support Vector Machine Classifiers.
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Ivana Bozic, Guanglan Zhang, and Vladimir Brusic
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- 2005
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25. Thyrotoxicosis after the cessation of amiodarone treatment
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Ivana Bozic Antic
- Published
- 2022
26. Effect of hyperglycemia and hyperinsulinemia on glutathione peroxidase activity in non-obese women with polycystic ovary syndrome
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Savic-Radojevic, Ana, Antic, Ivana Bozic, Coric, Vesna, Bjekic-Macut, Jelica, Radic, Tanja, Zarkovic, Milos, Djukic, Tatjana, Pljesa-Ercegovac, Marija, Panidis, Dimitrios, Katsikis, Ilias, Simic, Tatjana, and Macut, Djuro
- Published
- 2015
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27. Somatostatin receptor scintigraphy in the follow up of neuroendocrine neoplasms of appendix
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Djuro Macut, Dragana Sobic-Saranovic, Sanja Ognjanovic, Ivana Bozic Antic, Jelena Saponjski, Vera Artiko, and Djordje Pavlovic
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endocrine system ,Pathology ,medicine.medical_specialty ,Somatostatin receptor scintigraphy ,Appendix ,digestive system ,03 medical and health sciences ,0302 clinical medicine ,Retrospective Study ,medicine ,business.industry ,Follow up ,General Medicine ,Carcinoid ,digestive system diseases ,3. Good health ,surgical procedures, operative ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,Nuclear medicine ,Radionuclide ,030211 gastroenterology & hepatology ,business ,hormones, hormone substitutes, and hormone antagonists - Abstract
BACKGROUND Neuroendocrine tumors of appendix (ANETs) known as carcinoids, are rare endocrine neoplasms originated from enterochromaffin cells of gastrointestinal tract. ANETs are the third most frequent (16.7%) gastrointestinal neuroendocrine tumors, with the incidence of 0.08-0.2 cases/100000 during one year. Incidental ANETs occur in 0.2%-0.7% of emergency surgical resections because of suspected appendicitis which is usually the first manifestation of ANET. Although there are a lot of papers about application of somatostatin receptor scintigraphy in gastrointestinal neuroendocrine tumors, there are very rare sporadic cases described about ANETs particularly. AIM To establish the role of somatostatin receptor scintigraphy (SRS) in the management of patients with neuroendocrine tumors of appendix (ANET). METHODS The total of 35 patients was investigated, 23 females and 12 males, average age (43.7 ± 17.3 years). All patients had histological diagnosis of ANET (34 carcinoids of appendix and one tubular carcinoid). Majority of tumors have been found incidentally during surgery of: Acute appendicitis (n = 15), perforated appendicitis (n = 2), ileus (n = 3), hysterectomy (n = 3), ruptured ovarian cyst (n = 2), caecal volvulus (n = 1), while 9 patients had diagnosis of appendiceal tumor before the surgery. Seventeen patients had tumor grade (G) G1, 12 G2 and 6 G3. The right hemicolectomy was performed in 13, while the rest of the patients had appendectomy only. SRS was done early (2 h) and late (24 h) after i.v. application of 740 MBq technetium-99m ethylenediamine-N, N'-diacetic acid Hydrazinonicotinyl-Tyr3-Octreotide (technetium-99m-Tektrotyd, Polatom, Poland). SRS was performed for restaging in all the patients after surgery. RESULTS There were 12 true positive (TP), 19 true negative, 3 false positive and 1 false negative SRS result. Sensitivity of the method was 92.31%, specificity was 86.36%, positive predictive value was 80.00%, negative predictive value was 95.00% and accuracy 88.57%. Receiver operating characteristics analysis showed that SRS scintigraphy is a good test for detection TP cases [area under the curve of 0.850, 95% confidence interval (CI): 0.710-0.990, P < 001]. Single photon emission computed tomography contributed diagnosis in 7 TP findings. In 10 patients Krenning score was 4 and in 2 was 3. In 8 patients SRS significantly changed the management of the patients (in two surgery was repeated, in 4 somatostatin analogues and in two peptide receptor radionuclide therapy). Median progression-free survival in SRS positive patients was 52 months (95%CI: 39.7-117.3 mo) while in SRS negative patients it was 60 months (95%CI: 42.8-77.1 mo), without statistically significant difference between the two groups (P = 0.434). CONCLUSION In conclusion, our results confirmed the value of SRS in the follow-up of the patients with ANET after surgery, if recurrences or metastases are suspected.
- Published
- 2020
28. Delineating the evolutionary dynamics of cancer from theory to reality
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Ivana Bozic and Catherine J. Wu
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Cancer Research ,Response to therapy ,Computer science ,Theoretical models ,Cancer ,Context (language use) ,Patient data ,Computational biology ,medicine.disease ,Oncology ,Cancer evolution ,medicine ,Evolutionary dynamics ,Human cancer - Abstract
Uncovering and quantifying the laws of the evolutionary dynamics of cancer, in particular in the context of specific genetic lesions and in individual patients, has the potential to revolutionize precision oncology. Recent technological advances in the study of human cancer have increased access to in vivo human data and have thereby facilitated the confirmation or refutation of existing theoretical models. In this Perspective, we discuss recent work at the intersection of quantitative mathematical models of cancer evolution and patient data that provides insights into different stages of tumor evolution, including premalignant and malignant progression and response to therapy. Bozic and Wu discuss how quantitative mathematical models elucidate the various stages of tumor evolution, from premalignancy to malignant progression, and the response to therapy.
- Published
- 2020
29. A mechanistic mathematical model of initiation and malignant transformation in sporadic vestibular schwannoma
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X. Hoad, Ivana Bozic, Miriam J. Smith, D. G. R. Evans, and Chay Paterson
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Vestibular system ,Cancer Research ,Mutation rate ,medicine.medical_treatment ,Point mutation ,Loss of Heterozygosity ,Neuroma, Acoustic ,Models, Theoretical ,Biology ,Schwannoma ,Malignancy ,medicine.disease ,Malignant transformation ,Radiation therapy ,Loss of heterozygosity ,Cell Transformation, Neoplastic ,Oncology ,medicine ,Cancer research ,Humans ,Neurilemmoma - Abstract
Background A vestibular schwannoma (VS) is a relatively rare, benign tumour of the eighth cranial nerve, often involving alterations to the gene NF2. Previous mathematical models of schwannoma incidence have not attempted to account for alterations in specific genes, and could not distinguish between nonsense mutations and loss of heterozygosity (LOH). Methods Here, we present a mechanistic approach to modelling initiation and malignant transformation in schwannoma. Each parameter is associated with a specific gene or mechanism operative in Schwann cells, and can be determined by combining incidence data with empirical frequencies of pathogenic variants and LOH. Results This results in new estimates for the base-pair mutation rate u = 4.48 × 10−10 and the rate of LOH = 2.03 × 10−6/yr in Schwann cells. In addition to new parameter estimates, we extend the approach to estimate the risk of both spontaneous and radiation-induced malignant transformation. Discussion We conclude that radiotherapy is likely to have a negligible excess risk of malignancy for sporadic VS, with a possible exception of rapidly growing tumours.
- Published
- 2021
30. Individual and environmental correlates of childhood maltreatment and exposure to community violence: Utilizing a latent profile and a multilevel meta-analytic approach
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Michelle Cinguina, Dylan G. Gee, Arielle R. Baskin-Sommers, Jutta Joormann, Suzanne Estrada, and Ivana Bozic
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business.industry ,Lived experience ,05 social sciences ,Community violence ,Mental health ,03 medical and health sciences ,Psychiatry and Mental health ,0302 clinical medicine ,Meta-analysis ,Individual data ,Medicine ,Anxiety ,0501 psychology and cognitive sciences ,medicine.symptom ,business ,Psychosocial ,030217 neurology & neurosurgery ,Applied Psychology ,Depression (differential diagnoses) ,050104 developmental & child psychology ,Clinical psychology - Abstract
BackgroundChildhood maltreatment (CM) and exposure to community violence (ETV) are correlated with physical/mental health and psychosocial problems. Typically, CM and ETV are examined separately, by subtypes within category, or collapsed across both into one category of adversity. Consequently, research is limited in identifying subgroups of individuals with different amounts of exposure to both CM and ETV. Accordingly, we lack sufficient understanding of the extent to which problems associated with CM and ETV vary based on the amount (i.e. dose) of exposure to both of these experiences.MethodsWe used 20 samples (28,300 individuals) to estimate person-centered profiles of CM and ETV occurrence and co-occurrence within each sample. An individual data multilevel meta-analytic framework was used to determine the average effect size across samples for different profiles and conditional probability correlations within sociodemographic, neighborhood, health, mental health, and psychosocial domains.ResultsThe profile characterized by high levels of CM and high levels of ETV correlated with stressful life events, depression and anxiety symptoms, and general indicators of externalizing behaviors. CM predominant profiles were associated with mental health diagnoses and treatment. ETV predominant profiles associated with risk-taking/violent behavior and neighborhood-level disadvantage. However, nuance based on the dose of CM or ETV was evident.ConclusionsIt is important to identify subgroups based on the amount of exposure to CM and ETV. These subgroups have differential relationships with correlates across domains. Greater delineation and description of the lived experience will allow for more precision in addressing the burden of childhood adversity.
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- 2021
31. Growth dynamics in naturally progressing chronic lymphocytic leukaemia
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Wandi Zhang, Kanti R. Rai, John G. Gribben, Kristen E. Stevenson, Gad Getz, Catherine J. Wu, Oriol Olive, Alicia Wong, Laura Z. Rassenti, Stacey M. Fernandes, Jennifer R. Brown, Reaha Goyetche, Ivana Bozic, Johannes G. Reiter, Amaro Taylor-Weiner, Carrie Cibulskis, Thomas J. Kipps, Donna Neuberg, Daniel Rosebrock, Ignaty Leshchiner, Chip Stewart, Martin A. Nowak, Michael J. Keating, Dimitri Livitz, Michaela Gruber, Jing Sun, and Jeffrey M. Gerold
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Male ,0301 basic medicine ,Lymphoma ,Disease ,Somatic evolution in cancer ,Cohort Studies ,0302 clinical medicine ,Recurrence ,hemic and lymphatic diseases ,2.1 Biological and endogenous factors ,Chronic ,Aetiology ,Cancer ,Leukemia ,Multidisciplinary ,High-Throughput Nucleotide Sequencing ,Hematology ,Lymphocytic ,Local ,030220 oncology & carcinogenesis ,Disease Progression ,Female ,Evolution ,General Science & Technology ,Biology ,Article ,Evolution, Molecular ,03 medical and health sciences ,Rare Diseases ,Breast cancer ,Clinical Research ,Genetics ,medicine ,Humans ,Gene ,Cell Proliferation ,Lymphocytic leukaemia ,Human Genome ,Disease progression ,B-Cell ,Molecular ,Reproducibility of Results ,medicine.disease ,Leukemia, Lymphocytic, Chronic, B-Cell ,Clone Cells ,Neoplasm Recurrence ,030104 developmental biology ,Immunology ,Neoplasm Recurrence, Local - Abstract
How the genomic features of a patient’s cancer relate to individual disease kinetics remains poorly understood. Here we used the indolent growth dynamics of chronic lymphocytic leukaemia (CLL) to analyse the growth rates and corresponding genomic patterns of leukaemia cells from 107 patients with CLL, spanning decades-long disease courses. We found that CLL commonly demonstrates not only exponential expansion but also logistic growth, which is sigmoidal and reaches a certain steady-state level. Each growth pattern was associated with marked differences in genetic composition, the pace of disease progression and the extent of clonal evolution. In a subset of patients, whose serial samples underwent next-generation sequencing, we found that dynamic changes in the disease course of CLL were shaped by the genetic events that were already present in the early slow-growing stages. Finally, by analysing the growth rates of subclones compared with their parental clones, we quantified the growth advantage conferred by putative CLL drivers in vivo. Analysis of growth dynamics in a dataset from 107 patients with chronic lymphocytic leukaemia (CLL) reveals both exponential and logistic patterns of growth, which are associated with differences in genetic attributes and clinical outcomes.
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- 2019
32. Novel Mutations in Serbian MEN1 Patients: Genotype-Phenotype Correlation
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Svetozar Damjanovic, Milan Petakov, Ivana Bozic Antic, Bojana Popovic, Tatjana Isailovic, Tamara Bogavac, Dusan Ilic, Valentina Elezovic Kovacevic, Ivana Milicevic, Djuro Macut, and Sanja Ognjanovic
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endocrine system ,030213 general clinical medicine ,medicine.medical_specialty ,endocrine system diseases ,phenotype ,genotype ,030209 endocrinology & metabolism ,Genetic analysis ,Gastroenterology ,lcsh:Biochemistry ,Cancer syndrome ,03 medical and health sciences ,0302 clinical medicine ,Pituitary adenoma ,Internal medicine ,Genotype ,medicine ,lcsh:QD415-436 ,MEN1 ,fenotip ,Multiple endocrine neoplasia ,novel mutations ,Original Paper ,men 1 ,business.industry ,Point mutation ,medicine.disease ,3. Good health ,novootkrivene mutacije ,genotip ,business ,Primary hyperparathyroidism - Abstract
Summary Background: Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant cancer syndrome characterized by the occurrence of primary hyperparathyroidism (PHPT), pituitary adenoma (PA) and pancreatic neuroendocrine tumor (pNET). Whether the underlying mutations in MEN1 gene predict clinical presentation of affected heterozygotes or not, is still a matter of a debate. Methods: Clinical and genetic analysis of 90 consecutive MEN1 patients was performed in a retrospective, single – center study. Results: MEN1 mutation was found in 67 (74.4%) patients belonging to 31 different families. Twenty nine different heteozygous mutations were found, including 6 novel point mutations (W220G, 941delG, 1088del7, 1184insA, 1473del10, 1602del17) and one large deletion of exon 8. Truncating mutations predicted development of pNETs (OR=5.8, 95% CI 1.7 – 19.7%) and PHPT (OR=4.3, 95% CI 1.5 – 12.4%). Conclusions: Large number of novel mutations among MEN1 patients confirmed previously reported data. PNETs and PHPT were more frequent in patients with truncating mutations.
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- 2019
33. Acute Response to Endurance Exercise Stress: Focus on Catabolic/anabolic Interplay Between Cortisol, Testosterone, and Sex Hormone Binding Globulin in Professional Athletes
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Tatjana Isailovic, Valentina Elezovic Kovacevic, Dejana Popovic, Djuro Macut, Tamara Bogavac, Mirjana M. Vijatovic Petrovic, Svetozar Damjanovic, Ivana Bozic Antic, Dusan Ilic, Bojana Popovic, and Sanja Ognjanovic
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030213 general clinical medicine ,medicine.medical_specialty ,Anabolism ,catabolic/anabolic ,030209 endocrinology & metabolism ,endurance exercise ,lcsh:Biochemistry ,03 medical and health sciences ,0302 clinical medicine ,Sex hormone-binding globulin ,Endurance training ,Internal medicine ,Medicine ,Endocrine system ,lcsh:QD415-436 ,Treadmill ,Permissive ,Testosterone ,Original Paper ,biology ,business.industry ,Athletes ,biology.organism_classification ,sex hormone binding globulin ,Endocrinology ,testosterone ,biology.protein ,business - Abstract
Endocrine system plays a major role in both permissive and regulatory activities in order to adequately respond to physical stress of exercise. But level and direction of activation depend on many factors and are not easily interpreted.We tested a group of male professional athletes (21 water polo players and 15 wrestlers), together with 20 sedentary controls matched by age. All participants took a continuous progressive exercise stress test on a treadmill until exhaustion and plateau of oxygen consumption (VOCortisol levels significantly increased in both groups, but the response between S and MAX was more pronounced in controls (p=0.036). The athletes had significantly higher levels of cortisol in all points in test, except during R (p=0.118), when their cortisol levels gradually started to decline. Significant increase in total testosterone was in great deal a consequence of increase in SHBG level (p0.01 for both). Consequently, calculated free testosterone significantly decreased during test (p=0.008), and the drop was more pronounced in athletes. This was in concordance with significant correlation between SHBG and cortisol level demonstrated in athletes, but not in controls.It seems that high intensity endurance exercise favors catabolic response, but the level of response highly depends on a previous level of training.Endokrini sistem ima i permisivnu i regulatornu ulogu kako bi se adekvatno odgovorilo na fizički stress prouzrokovan vežbanjem. Ali nivo i smer aktivacije zavise od mnogih faktora i nisu jednostavni za interpretaciju.Testirali smo grupu muških profesionalnih sportista (21 vaterpolista i 15 rvača), i 20 sedentarnih kontrola upa renih prema godinama. Sproveden je ergospirome trijski test do iscrpljenosti i platoa potrošnje kiseonika (VONivo kortizola je značajno porastao u obe grupe, ali je odgovor između S i MAX bio naglašeniji kod kontrola (p=0,036). Sportisti su imali značajno više vrednosti kortizola u svim tačkama testa, izuzev tokom R (p=0,118), s obzirom da su njihove vrednosti kortizola počele da opadaju. Značajan porast vrednosti ukupnog testosterona je u velikoj meri bio posledica porasta nivoa SHBG (p0,01 za oba). Posledično, izračunate vrednosti slobodnog testosterona su značajno opadale tokom testa (p=0,008), a pad je bio izraženiji kod sportista. Ovaj rezultat je u skladu sa demonstriranom značajnom korelacijom između SHBG i korti zola kod sportista, ali ne i kod kontrola.Naši rezultati ukazuju da trening izdržljivosti visokog intenziteta favorizuje katabolički odgovor, ali nivo odgovora značajno zavisi od nivoa utreniranosti.
- Published
- 2019
34. Quantification of the Selective Advantage of Driver Mutations Is Dependent on the Underlying Model and Stage of Tumor Evolution
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Ivana Bozic
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Cancer Research ,Oncology ,Neoplasms ,Mutation ,Tumor Microenvironment ,Humans ,Neoplasm Staging - Abstract
Measuring the selective fitness advantages provided by driver mutations has the potential to facilitate a precise quantitative understanding of cancer evolution. However, accurately measuring the selective advantage of driver mutations has remained a challenge in the field. Early studies reported small selective advantages of drivers, on the order of 1%, whereas newer studies report much larger selective advantages, as high as 1,200%. In this article, we argue that the calculated selective advantages of cancer drivers are dependent on the underlying mathematical model and stage of cancer evolution and that comparisons of numerical values of selective advantage without regard for the underlying model and stage can lead to spurious conclusions.
- Published
- 2021
35. Estimating the rate of plasmid transfer with an adapted Luria–Delbrück fluctuation analysis
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Olivia Kosterlitz, Adamaris Muñiz Tirado, Claire Wate, Clint Elg, Ivana Bozic, Eva M. Top, and Benjamin Kerr
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education.field_of_study ,Plasmid ,Transfer (computing) ,Conjugative plasmid ,Population ,Limiting ,Biological system ,education ,Mathematics - Abstract
To increase our basic understanding of the ecology and evolution of conjugative plasmids, we need a reliable estimate of their rate of transfer between bacterial cells. However, accurate estimates of plasmid transfer have remained elusive due to biological and experimental complexity. Current methods to measure transfer rate can be confounded by many factors. A notable example involves plasmid transfer between different strains or species where the rate that one type of cell donates the plasmid is not equal to the rate at which the other cell type donates. Asymmetry in these rates has the potential to bias or constrain current transfer estimates, thereby limiting our capabilities for estimating transfer in microbial communities. Inspired by the classic fluctuation analysis of Luria and Delbrück, we develop a novel approach, the Luria-Delbrück method (‘LDM’), for estimating plasmid transfer rate. Our new approach embraces the stochasticity of conjugation departing from the current deterministic population dynamic methods. In addition, the LDM overcomes obstacles of traditional methods by not being affected by different growth and transfer rates for each population within the assay. Using stochastic simulations and experiments, we show that the LDM has high accuracy and precision for estimation of transfer rates compared to the most widely used methods, which can produce estimates that differ from the LDM estimate by orders of magnitude.Significance StatementConjugative plasmids play significant roles in the ecology and evolution of microbial communities. Notably, antibiotic resistance genes are often encoded on conjugative plasmids. Thus, conjugation—the transfer of a plasmid copy from one cell to another—is a common way for antibiotic resistance to spread between important clinical pathogens. For both public health modeling and a basic understanding of microbial population biology, accurate estimates of this fundamental rate are of great consequence. We show that widely used methods can lead to biased estimates, deviating from true values by several orders of magnitude. Therefore, we developed a new approach, inspired by the classic fluctuation analysis of Luria and Delbrück, for accurately assessing the rate of plasmid conjugation under a variety of conditions.
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- 2021
36. Abstract IA020: Dynamics of response and resistance to cancer therapy
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Ivana Bozic
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Cancer Research ,Oncology - Abstract
Despite the effectiveness of many cancer therapies in reducing tumor burden for significant amounts of time in a subset of patients, primary and acquired resistance to treatment remain one of the biggest challenges in the effort to cure cancer. Successful management, or prevention, of resistance requires deciphering the mechanisms by which it arises, and in particular whether it stems from pre-existing cell populations or arises de novo during therapy. Using evolutionary principles and mathematical techniques together with patient data, we aim to develop a precise mathematical understanding of the dynamics of response and resistance to various cancer therapies, including targeted therapies and immunotherapy. Our work shows that therapies that maximize the killing rate of cancer cells may not be optimal, and that instead the parameters determining the fraction of resistant cells and their growth rate have a larger effect on the long-term control of cancer. Citation Format: Ivana Bozic. Dynamics of response and resistance to cancer therapy [abstract]. In: Proceedings of the AACR Special Conference on the Evolutionary Dynamics in Carcinogenesis and Response to Therapy; 2022 Mar 14-17. Philadelphia (PA): AACR; Cancer Res 2022;82(10 Suppl):Abstract nr IA020.
- Published
- 2022
37. Exploring attitudes towards digital advertisements on social networks: The case study of the Nišava and Pčinja districts
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Miloš Stojanović, Ivana Božić Miljković, Pavle Mitić, and Anja Veličković
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paid ads ,advertising ,social networks ,consumers ,Economics as a science ,HB71-74 - Abstract
This paper aims to analyze the importance of paid advertising on social networks in the territory of Nišava and Pčinja districts. For this reason, a survey was conducted, which included 294 respondents. Data were processed in the SPPS software package, using tests of independence, contingency, one-factor analysis of variance, and post-hoc tests. The results showed that the majority of respondents from the south of Serbia ignore paid ads on social networks. Also, the study led us to the conclusion that paid advertising affects men and women equally, but also that it has the greatest impact on the population over 50 years old, while it has the least impact on respondents up to 30 years old, as well as that there is a strong connection between the level of education and clicks on paid ads. The results showed that respondents who do not open ads do not do so because they do not notice them, but also that highly educated people open ads for informative reasons and to get to know the advertised business.
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- 2023
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38. Gonadal dysfunction in male patients with neuroendocrine tumors
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Popovic, Bojana, primary, Antic, Ivana Bozic, additional, Isailovic, Tatjana, additional, Bogavac, Tamara, additional, Ilic, Dusan, additional, Kovacevic, Valentina Elezovic, additional, Opalic, Milica, additional, Ognjanovic, Sanja, additional, and Macut, Djuro, additional
- Published
- 2021
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39. Hyperprogression of Merkel cell carcinoma during immunotherapy
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Ivana, Bozic-Antic, primary, Jovanovic, Marko, additional, Petkovic, Ana, additional, Micev, Marjan, additional, Popovic, Bojana, additional, Ognjanovic, Sanja, additional, Tatjana, Isailovic, additional, Ilic, Dusan, additional, Bogavac, Tamara, additional, Opalic, Milica, additional, Valentina, Elezovic-Kovacevic, additional, and Macut, Djuro, additional
- Published
- 2021
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40. Inferring parameters of cancer evolution from sequencing and clinical data
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Nicole Lee and Ivana Bozic
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Mutation rate ,Cancer evolution ,Genomic Profile ,Mutation (genetic algorithm) ,medicine ,Cancer ,Computational biology ,Patient data ,Biology ,medicine.disease ,Carcinogenesis ,medicine.disease_cause ,Event (probability theory) - Abstract
As a cancer develops, its cells accrue new mutations, resulting in a heterogeneous, complex genomic profile. We make use of this heterogeneity to derive simple, analytic estimates of parameters driving carcinogenesis and reconstruct the timeline of selective events following initiation of an individual cancer. Using stochastic computer simulations of cancer growth, we show that we can accurately estimate mutation rate, time before and after a driver event occurred, and growth rates of both initiated cancer cells and subsequently appearing subclones. We demonstrate that in order to obtain accurate estimates of mutation rate and timing of events, observed mutation counts should be corrected to account for clonal mutations that occurred after the founding of the tumor, as well as sequencing coverage. We apply our methodology to reconstruct the individual evolutionary histories of chronic lymphocytic leukemia patients. Fitting our model to longitudinal patient data reveals strengths and weaknesses of using an exponential model of cancer growth with constant mutation rate to estimate parameters of cancer evolution.
- Published
- 2020
41. Correlation of chromogranin a and standard metabolic parameters in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs)
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Valentina Elezovic-Kovacevic, Djuro Macut, Dusan Ilic, Tamara Bogavac, Sanja Ognjanovic, Ivana Bozic-Antic, Bojana Popovic, and Tatjana Isailovic
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Correlation ,Pathology ,medicine.medical_specialty ,biology ,business.industry ,biology.protein ,Medicine ,Chromogranin A ,In patient ,Neuroendocrine tumors ,business ,medicine.disease - Published
- 2020
42. Association of the subclinical hypercorticism and BclI glucocorticoid receptor polymorphism with bone mineral density in women with adrenal incidentalomas
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Sanja Ognjanovic, Tamara Bogavac, Djuro Macut, Tatjana Isailovic, Antic Ivana Bozic, Bojana Popovic, Dusan Ilic, Jadranka Antic, Svetozar Damjanovic, and Kovacevic Valentina Elezovic
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Bone mineral ,medicine.medical_specialty ,Endocrinology ,business.industry ,Internal medicine ,Medicine ,GLUCOCORTICOID RECEPTOR POLYMORPHISM ,business ,Subclinical infection - Published
- 2020
43. Cortisol response to acute stress is dependent on previous stress exposure and sex of the examined humans
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Antic Ivana Bozic, Tamara Bogavac, Dejana Popovic, Sanja Ognjanovic, Djuro Macut, Tatjana Isailovic, Svetozar Damjanovic, Marko Banovic, Kovacevic Valentina Elezovic, Dusan Ilic, and Bojana Popovic
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Stress exposure ,business.industry ,Physiology ,Medicine ,Acute stress ,business - Published
- 2020
44. Modelling CAR T-cell Therapy with Patient Preconditioning
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Ivana Bozic and Katherine Lacy Owens
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medicine.medical_specialty ,Chemotherapy ,business.industry ,medicine.medical_treatment ,Standard treatment ,Medical practice ,Context (language use) ,Chimeric antigen receptor ,Blood cancer ,Regimen ,medicine ,CAR T-cell therapy ,Intensive care medicine ,business - Abstract
The Federal Drug Administration (FDA) approved the first Chimeric Antigen Receptor T-cell (CAR T-cell) therapies for the treatment of several blood cancers in 2017, and efforts are underway to broaden CAR T technology to address other cancer types. Standard treatment protocols incorporate a preconditioning regimen of lymphodepleting chemotherapy prior to CAR T-cell infusion. However, the connection between preconditioning regimens and patient outcomes is still not fully understood. Optimizing patient preconditioning plans and reducing the CAR T-cell dose necessary for achieving remission could make therapy safer. In this paper, we test treatment regimens consisting of sequential administration of chemotherapy and CAR T-cell therapy on a system of differential equations that models the tumor-immune interaction. We use numerical simulations of treatment plans from within the scope of current medical practice to assess the effect of preconditioning plans on the success of CAR T-cell therapy. Model results affirm clinical observations that preconditioning can be crucial for some patients, not just to reduce side effects, but to even achieve remission at all. We demonstrate that preconditioning plans using the same CAR T-cell dose and the same total concentration of chemotherapy can lead to different patient outcomes due to different delivery schedules. Results from sensitivity analysis of the model parameters suggest that making small improvements in the effectiveness of CAR T-cells in attacking cancer cells, rather than targeting the recruitment and longevity of CAR T-cells, will significantly reduce the minimum dose required for successful treatment. Our modeling framework represents a starting point for evaluating the efficacy of patient preconditioning in the context of CAR T-cell therapy.
- Published
- 2020
45. Mathematical Model of Colorectal Cancer Initiation
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Hans Clevers, Ivana Bozic, Chay Paterson, and Hubrecht Institute for Developmental Biology and Stem Cell Research
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Mutation rate ,Genes, APC ,Carcinogenesis ,Colorectal cancer ,medicine.disease_cause ,law.invention ,Cancer evolution ,Proto-Oncogene Proteins p21(ras) ,Proto-Oncogene Proteins p21(ras)/genetics ,Genes, APC/physiology ,Immune system ,Theoretical ,Mutation Rate ,law ,Models ,Genotype ,Medicine ,Humans ,p53/genetics ,ras ,Mutation ,Multidisciplinary ,Oncogene ,business.industry ,APC/physiology ,Driver mutations ,Cancer ,Colonic Neoplasms/genetics ,Oncogenes ,Biological Sciences ,Models, Theoretical ,Genes, p53 ,medicine.disease ,Colorectal Neoplasms/genetics ,Genes, p53/genetics ,Genes, ras ,Stochastic model ,Genes ,Colonic Neoplasms ,Cancer research ,Disease Progression ,Suppressor ,Tumor Suppressor Protein p53/genetics ,KRAS ,Carcinogenesis/genetics ,Tumor Suppressor Protein p53 ,Colorectal Neoplasms ,business - Abstract
Quantifying evolutionary dynamics of cancer initiation and progression can provide insights into more effective strategies of early detection and treatment. Here we develop a mathematical model of colorectal cancer initiation through inactivation of two tumor suppressor genes and activation of one oncogene, accounting for the well-known path to colorectal cancer through loss of tumor suppressors APC and TP53, and gain of the KRAS oncogene. In the model, we allow mutations to occur in any order, leading to a complex network of incomplete mutational genotypes on the way to colorectal cancer. We parametrize the model using experimentally measured parameter values, many of them only recently available, and compare its predictions to epidemiological data on colorectal cancer incidence. We find that the reported incidence of colorectal cancer can be recovered using a mathematical model of colorectal cancer initiation together with experimentally measured mutation rates in colorectal tissues and proliferation rates of premalignant lesions. We demonstrate that the order of driver events in colorectal cancer is determined by the combined effect of the rates at which driver genes are mutated and the fitness effects they provide. Our results imply that there may not be significant immune suppression of untreated benign and malignant colorectal lesions.
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- 2020
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46. Models of Drug Induced Liver Injury (DILI) – Current Issues and Future Perspectives
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Edgar Kralj, Margareta Mrso, Kristina Bojanic, Martina Smolić, Robert Smolić, Ivana Bozic, Lucija Kuna, George Y. Wu, and Tomislav Kizivat
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0301 basic medicine ,Drug ,medicine.medical_specialty ,Web of science ,media_common.quotation_subject ,Clinical Biochemistry ,MEDLINE ,Scopus ,Models, Biological ,Article ,Cell Line ,03 medical and health sciences ,preclinical ,Medicine ,Animals ,Humans ,Intensive care medicine ,media_common ,Pharmacology ,drug evaluation studies ,evidence-based toxicology ,liver injury ,drug-induced ,side effects ,Tissue Engineering ,business.industry ,Liver failure ,Drug evaluation studies ,Genomics ,Evidence-based toxicology ,030104 developmental biology ,Liver ,Models, Animal ,Research development ,Chemical and Drug Induced Liver Injury ,business ,Biomarkers - Abstract
BACKGROUND: Drug-induced Liver Injury (DILI) is an important cause of acute liver failure cases in the United States, and remains a common cause of withdrawal of drugs in both preclinical and clinical phases. METHODS: A structured search of bibliographic databases - Web of Science Core Collection, Scopus and Medline for peer-reviewed articles on models of DILI was performed. The reference lists of relevant studies was prepared and a citation search for the included studies was carried out. In addition, the characteristics of screened studies were described. RESULTS: One hundred and six articles about the existing knowledge of appropriate models to study DILI in vitro and in vivo with special focus on hepatic cell models, variations of 3D co-cultures, animal models, databases and predictive modeling and translational biomarkers developed to understand the mechanisms and pathophysiology of DILI are described. CONCLUSION: Besides descriptions of current applications of existing modeling systems, associated advantages and limitations of each modeling system and future directions for research development are discussed as well.
- Published
- 2018
47. The evolutionary landscape of chronic lymphocytic leukemia treated with ibrutinib targeted therapy
- Author
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Wandi Zhang, Carrie Cibulskis, Joshua A Fein, Clare Sun, Sarangan Ravichandran, Catherine J. Wu, Jan A. Burger, Mohammed Farooqui, Mariela Sivina, Gad Getz, Sarah E. M. Herman, Adrian Wiestner, Ivana Bozic, Ignaty Leshchiner, Donna Neuberg, Dimitri Livitz, Daniel Rosebrock, Julia Hoellenriegel, Chingiz Underbayev, Asaf Zviran, Delong Liu, and Dan A. Landau
- Subjects
0301 basic medicine ,Male ,medicine.medical_treatment ,Chronic lymphocytic leukemia ,General Physics and Astronomy ,Targeted therapy ,chemistry.chemical_compound ,0302 clinical medicine ,Piperidines ,immune system diseases ,hemic and lymphatic diseases ,Antineoplastic Combined Chemotherapy Protocols ,Agammaglobulinaemia Tyrosine Kinase ,Longitudinal Studies ,Molecular Targeted Therapy ,lcsh:Science ,Exome ,Exome sequencing ,Aged, 80 and over ,Multidisciplinary ,biology ,Cell cycle ,Middle Aged ,Protein-Tyrosine Kinases ,Prognosis ,3. Good health ,Gene Expression Regulation, Neoplastic ,Leukemia ,Treatment Outcome ,030220 oncology & carcinogenesis ,Ibrutinib ,Disease Progression ,Female ,Rituximab ,Signal Transduction ,Adult ,Science ,Down-Regulation ,General Biochemistry, Genetics and Molecular Biology ,Article ,Clonal Evolution ,03 medical and health sciences ,Exome Sequencing ,medicine ,Bruton's tyrosine kinase ,Humans ,Aged ,Phospholipase C gamma ,Adenine ,General Chemistry ,medicine.disease ,Leukemia, Lymphocytic, Chronic, B-Cell ,030104 developmental biology ,Pyrimidines ,chemistry ,Drug Resistance, Neoplasm ,Mutation ,Cancer research ,biology.protein ,Pyrazoles ,lcsh:Q - Abstract
Treatment of chronic lymphocytic leukemia (CLL) has shifted from chemo-immunotherapy to targeted agents. To define the evolutionary dynamics induced by targeted therapy in CLL, we perform serial exome and transcriptome sequencing for 61 ibrutinib-treated CLLs. Here, we report clonal shifts (change >0.1 in clonal cancer cell fraction, Q, In a subset of patients with chronic lymphocytic leukemia (CLL) treated with targeted agents, such as ibrutinib, drug resistant subclones emerge. Here, the authors report on transcriptional changes in CLL patients treated with ibrutinib and identify early clonal shifts associated with evolution of resistant clones.
- Published
- 2017
48. Somatostatin receptor scintigraphy in the follow up of neuroendocrine neoplasms of appendix
- Author
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Saponjski, Jelena, primary, Macut, Djuro, additional, Sobic-Saranovic, Dragana, additional, Ognjanovic, Sanja, additional, Antic, Ivana Bozic, additional, Pavlovic, Djordje, additional, and Artiko, Vera, additional
- Published
- 2020
- Full Text
- View/download PDF
49. Resisting Resistance
- Author
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Ivana Bozic and Martin A. Nowak
- Subjects
0301 basic medicine ,03 medical and health sciences ,Cancer Research ,030104 developmental biology ,0302 clinical medicine ,Oncology ,030220 oncology & carcinogenesis ,Cell Biology - Abstract
Targeted therapies, immunotherapies, and improved chemotherapies are being developed to reduce the suffering and mortality that come from human cancer. Although these approaches, and in particular combinations of them, are expected to succeed eventually to a large degree, they all suffer one obstacle: Populations of replicating cells move away—typically in a high-dimensional space—from any opposing selection pressure they encounter. They evolve resistance. It is possible, however, to develop a precise mathematical understanding of the problem and to design treatment strategies that prevent resistance if possible or manage resistance otherwise. In this article, we present the fundamental equations that characterize the evolution of resistance. We provide formulas for the probability that resistant cells exist at the start of therapy, for the average number and sizes of resistant clones, and for the probability of successful combination treatment. We also demonstrate that developing new therapies that only maximize the killing rate of cancer cells may not be optimal, and that instead the parameters determining the fraction of resistant cells and their growth rate have a larger effect on the long-term control of cancer. These mathematical tools inform the search process for optimal therapies that aim to cure cancer.
- Published
- 2017
50. Knowledge of French language and culture: A precondition for improving economic relations between Serbia and France
- Author
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Ivana Bozic-Miljkovic, Danijel Zivkovic, and Svetlana Mihic
- Subjects
Intercultural competence ,media_common.quotation_subject ,Language barrier ,French ,Complementarity (physics) ,language.human_language ,Precondition ,Friendship ,Intercultural relations ,Economy ,Political science ,language ,Economic system ,Business communication ,media_common - Abstract
France is one of the largest economies of the world and one of the most influential countries of the EU, and its centuries-old friendship with Serbia and a strategic position in the Western Balkans and the complementarity of economies represent a good basis for the development of bilateral economic relations. However, despite the great potential for cooperation, mutual cooperation results to date are not at a high level. One of the reasons may well be just the language barrier and the lack of knowledge of French market culture. The aim of this paper is to present forms of economic cooperation between Serbia and France, to emphasize the importance of the knowledge of French language and intercultural competence as a prerequisite for cooperation, at least in the initial marketing terms. In this paper, we will give a brief historical overview of the French economic relations, and by employing a complementary analysis we will present the mutual trade between the two countries, and we will as well point out the importance of knowing the French language and French culture to the employees who have plans for successful cooperation with French partners.
- Published
- 2017
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