scholarly journals Evolutionary dynamics of imatinib-treated leukemic cells by stochastic approach

Open Physics ◽  
2009 ◽  
Vol 7 (3) ◽  
Author(s):  
Nicola Pizzolato ◽  
Davide Valenti ◽  
Dominique Adorno ◽  
Bernardo Spagnolo

AbstractThe evolutionary dynamics of a system of cancerous cells in a model of chronic myeloid leukemia (CML) is investigated by a statistical approach. Cancer progression is explored by applying a Monte Carlo method to simulate the stochastic behavior of cell reproduction and death in a population of blood cells which can experience genetic mutations. In CML front line therapy is represented by the tyrosine kinase inhibitor imatinib which strongly affects the reproduction of leukemic cells only. In this work, we analyze the effects of a targeted therapy on the evolutionary dynamics of normal, first-mutant and cancerous cell populations. Several scenarios of the evolutionary dynamics of imatinib-treated leukemic cells are described as a consequence of the efficacy of the different modelled therapies. We show how the patient response to the therapy changes when a high value of the mutation rate from healthy to cancerous cells is present. Our results are in agreement with clinical observations. Unfortunately, development of resistance to imatinib is observed in a fraction of patients, whose blood cells are characterized by an increasing number of genetic alterations. We find that the occurrence of resistance to the therapy can be related to a progressive increase of deleterious mutations.

Cancers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 946 ◽  
Author(s):  
Paola Del Bianco ◽  
Camilla Stagni ◽  
Silvia Giunco ◽  
Alessio Fabozzi ◽  
Lisa Elefanti ◽  
...  

Resistance is a major challenge in the management of mitogen-activated protein kinase inhibitor (MAPKi)-treated metastatic melanoma. Tumor genetic alterations can cause MAPK pathway reactivation, leading to lack of response and poor outcome. Characterization of the mutational profile in patients with melanoma might be crucial for patient-tailored treatment choices. Mutations in the promoter region of the telomerase reverse transcriptase gene (TERTprom) lead to increased TERT expression and telomerase activity and are frequent in BRAFV600 mutant melanoma. Reportedly, TERTprom, and BRAFV600 mutations cooperate in driving cancer progression and aggressiveness. We evaluated the effect of the TERTprom status on the clinical outcome in 97 MAPKi-treated melanoma patients. We observed that patients with the c.-146C > T mutation showed a significantly worse progression-free survival (PFS) compared to those carrying the c.-124C > T mutation and a two-fold increased risk of progression (median 5.4 vs. 9.5 months; hazard ratio (HR) 1.9; 95% confidence interval (CI) 1.2–3.2; p = 0.013). This trend was also observed for the overall survival (OS); melanoma patients with the c.-146C > T mutation showed a poorer prognosis compared to those with the c.-124C > T mutation (median 13.3 vs. 25.5 months; HR 1.9, 95% CI 1.1–3.3, p = 0.023). Our results disclose a different correlation of the two TERTprom mutations with MAPKi-treated melanoma patient outcome, highlighting a different impact of the pathway blockade.


Author(s):  
Alireza Farahinia ◽  
W.J. Zhang ◽  
Ildiko Badea

Separation and interpretation of rebellious Circulating Tumor Cells (CTCs) originating from the primary tumor or cancer tissue plays a significant role in diagnostics, cancer progression analyses, suitable medicine exploration, and treatment proficiency examination. Cancer metastasis occurs when CTCs spread throughout the body and invade healthy tissues, leading to new tumors in that area. Although a dramatic rate of deaths begins from spreading CTCs around the body, valuable measures have been made to control their development. However, the first step is separating these harmful cells from the bloodstream and investigating their features. Having examined the characteristics of CTCs as cancer’s main strength, researchers can introduce complementary treatments that can affect cancerous cells without damaging the healthy cells. Therefore, according to their unique characteristics, numerous techniques have been established for continuous and fast separation and sorting of CTCs. Nevertheless, few separators enjoy the efficient performance and appropriate accuracy and can be produced in mass numbers due to the available fabrication equipment. Microfabrication advancements enable separators to combine the advantages of active and passive methods in a small-scale platform for probing individual cells and separation purposes. Reduction in reagents, sample volume, analysis time, and less harmfulness to patients are some of the motivations that encourage researchers to employ microfluidic instruments for CTCs separation from other blood cells over the last two decades. However, microfabrication limitations mean effective separators, and the diagnostic option they provide, are not readily available. Addressing these limitations requires optimizing the design and fabrication of separators such that they are reduced in their size and fabrication cost, while also maintaining high-throughput separating capability. The emergence of the Lab-On-a-Chip (LOC) and then Lab-On-a-CD (LOCD) technologies, having more inherent benefits than conventional microfluidic devices, has created new opportunities and become increasingly widespread in recent years. Evidence suggests that employing single methodologies or integrating approaches without sufficient understanding of potential outcomes is unlikely to result in successful diagnostic results. This paper contributes an extensive review of several separation systems, including fundamental theories and experimental details, and describes detailed operating principles and device performance.


Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3465
Author(s):  
Aya Saleh ◽  
Ruth Perets

Mutations in tumor suppressor gene TP53, encoding for the p53 protein, are the most ubiquitous genetic variation in human ovarian HGSC, the most prevalent and lethal histologic subtype of epithelial ovarian cancer (EOC). The majority of TP53 mutations are missense mutations, leading to loss of tumor suppressive function of p53 and gain of new oncogenic functions. This review presents the clinical relevance of TP53 mutations in HGSC, elaborating on several recently identified upstream regulators of mutant p53 that control its expression and downstream target genes that mediate its roles in the disease. TP53 mutations are the earliest genetic alterations during HGSC pathogenesis, and we summarize current information related to p53 function in the pathogenesis of HGSC. The role of p53 is cell autonomous, and in the interaction between cancer cells and its microenvironment. We discuss the reduction in p53 expression levels in tumor associated fibroblasts that promotes cancer progression, and the role of mutated p53 in the interaction between the tumor and its microenvironment. Lastly, we discuss the potential of TP53 mutations to serve as diagnostic biomarkers and detail some more advanced efforts to use mutated p53 as a therapeutic target in HGSC.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Verônica R. de Melo Costa ◽  
Julianus Pfeuffer ◽  
Annita Louloupi ◽  
Ulf A. V. Ørom ◽  
Rosario M. Piro

Abstract Background Introns are generally removed from primary transcripts to form mature RNA molecules in a post-transcriptional process called splicing. An efficient splicing of primary transcripts is an essential step in gene expression and its misregulation is related to numerous human diseases. Thus, to better understand the dynamics of this process and the perturbations that might be caused by aberrant transcript processing it is important to quantify splicing efficiency. Results Here, we introduce SPLICE-q, a fast and user-friendly Python tool for genome-wide SPLICing Efficiency quantification. It supports studies focusing on the implications of splicing efficiency in transcript processing dynamics. SPLICE-q uses aligned reads from strand-specific RNA-seq to quantify splicing efficiency for each intron individually and allows the user to select different levels of restrictiveness concerning the introns’ overlap with other genomic elements such as exons of other genes. We applied SPLICE-q to globally assess the dynamics of intron excision in yeast and human nascent RNA-seq. We also show its application using total RNA-seq from a patient-matched prostate cancer sample. Conclusions Our analyses illustrate that SPLICE-q is suitable to detect a progressive increase of splicing efficiency throughout a time course of nascent RNA-seq and it might be useful when it comes to understanding cancer progression beyond mere gene expression levels. SPLICE-q is available at: https://github.com/vrmelo/SPLICE-q


Blood ◽  
2005 ◽  
Vol 105 (7) ◽  
pp. 2733-2740 ◽  
Author(s):  
Baijun Fang ◽  
Chunmei Zheng ◽  
Lianming Liao ◽  
Qin Han ◽  
Zhao Sun ◽  
...  

AbstractOverwhelming evidence from leukemia research has shown that the clonal population of neoplastic cells exhibits marked heterogeneity with respect to proliferation and differentiation. There are rare stem cells within the leukemic population that possess extensive proliferation and self-renewal capacity not found in the majority of the leukemic cells. These leukemic stem cells are necessary and sufficient to maintain the leukemia. Interestingly, the BCR/ABL fusion gene, which is present in chronic myelogenous leukemia (CML), was also detected in the endothelial cells of patients with CML, suggesting that CML might originate from hemangioblastic progenitor cells that can give rise to both blood cells and endothelial cells. Here we isolated fetal liver kinase-1–positive (Flk1+) cells carrying the BCR/ABL fusion gene from the bone marrow of 17 Philadelphia chromosome–positive (Ph+) patients with CML and found that these cells could differentiate into malignant blood cells and phenotypically defined endothelial cells at the single-cell level. These findings provide direct evidence for the first time that rearrangement of the BCR/ABL gene might happen at or even before the level of hemangioblastic progenitor cells, thus resulting in detection of the BCR/ABL fusion gene in both blood and endothelial cells.


Blood ◽  
2004 ◽  
Vol 103 (6) ◽  
pp. 2299-2307 ◽  
Author(s):  
Masayuki Okada ◽  
Souichi Adachi ◽  
Tsuyoshi Imai ◽  
Ken-ichiro Watanabe ◽  
Shin-ya Toyokuni ◽  
...  

Abstract Caspase-independent programmed cell death can exhibit either an apoptosis-like or a necrosis-like morphology. The ABL kinase inhibitor, imatinib mesylate, has been reported to induce apoptosis of BCR-ABL–positive cells in a caspase-dependent fashion. We investigated whether caspases alone were the mediators of imatinib mesylate–induced cell death. In contrast to previous reports, we found that a broad caspase inhibitor, zVAD-fmk, failed to prevent the death of imatinib mesylate–treated BCR-ABL–positive human leukemic cells. Moreover, zVAD-fmk–preincubated, imatinib mesylate–treated cells exhibited a necrosis-like morphology characterized by cellular pyknosis, cytoplasmic vacuolization, and the absence of nuclear signs of apoptosis. These cells manifested a loss of the mitochondrial transmembrane potential, indicating the mitochondrial involvement in this caspase-independent necrosis. We excluded the participation of several mitochondrial factors possibly involved in caspase-independent cell death such as apoptosis-inducing factor, endonuclease G, and reactive oxygen species. However, we observed the mitochondrial release of the serine protease Omi/HtrA2 into the cytosol of the cells treated with imatinib mesylate or zVAD-fmk plus imatinib mesylate. Furthermore, serine protease inhibitors prevented the caspase-independent necrosis. Taken together, our results suggest that imatinib mesylate induces a caspase-independent, necrosis-like programmed cell death mediated by the serine protease activity of Omi/HtrA2.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e13557-e13557
Author(s):  
Manish Sharma ◽  
Anitha Singareddy ◽  
Surabhi Bajpai ◽  
Jayant Narang ◽  
Michael O'Connor ◽  
...  

e13557 Background: Lung cancer is the leading cause of cancer death in the world including more than 160,000 deaths in the US. The purpose of the study was to determine whether inter reader variability in Sum of Diameters (SOD) of tumor burden has any correlation with variability in end point assessment in lung cancer progression. RECIST 1.1 is based on the SOD of target lesions seen on imaging studies. Response criteria for evaluation of target lesions include - Complete response (CR), Partial response (PR), Progressive disease (PD) and Stable disease (SD). The key determinant of patient response is based on Target Lesion response which in turn is determined by SOD. Inter reader variability study plays an important role in the development of reliable diagnostic tools and understanding of imaging outcomes given the confounding factors like effusion, atelectasis and consolidation in lung cancer that affect Target Lesion selection. Methods: Retrospective analysis of 470 patients was carried out using RECIST 1.1. Double read with adjudication is the preferred read model for submission studies where images are read by two independent reviewers blinded to treatment allocation. As per RECIST 1.1, lesions were measured in the longest diameter for non-nodal and short axis for nodal lesions. This was followed by the calculation of SOD for total tumor burden. If these two primary reviewers disagree, then a third radiologist, the “adjudicator”, reviews the assessments performed by the first two radiologists and selects between the more accurate one. For further analysis, patients were divided into 2 groups, the one with no adjudication i.e. agreement between both readers and the second group with adjudication i.e. disagreement between both readers and ANOVA was used to perform analysis of Variance. Results: Of 470 patients, 332 patients with disagreement were adjudicated, while there was agreement on 138 patients assessments between both readers. SOD of baseline visits for all patients was assessed using ANOVA - single factor with following results: F ratio of 4.76 for Disagreement group was more than F crit (3.86) with P-value 0.03, while for Agreement group F value was less than F crit. Conclusions: There is a direct relationship of variability in SOD at baseline between two readers to the possibility of disagreement in their end point assessment. Additional rules around selection and measurement of Target Lesions should be proposed in protocol to reduce variability and improve endpoint assessment outcomes.[Table: see text]


Blood ◽  
2005 ◽  
Vol 106 (12) ◽  
pp. 3958-3961 ◽  
Author(s):  
Jörg Cammenga ◽  
Stefan Horn ◽  
Ulla Bergholz ◽  
Gunhild Sommer ◽  
Peter Besmer ◽  
...  

Multiple genetic alterations are required to induce acute myelogenous leukemia (AML). Mutations in the extracellular domain of the KIT receptor are almost exclusively found in patients with AML carrying translocations or inversions affecting members of the core binding factor (CBF) gene family and correlate with a high risk of relapse. We demonstrate that these complex insertion and deletion mutations lead to constitutive activation of the KIT receptor, which induces factor-independent growth of interleukin-3 (IL-3)–dependent cells. Mutation of the evolutionary conserved amino acid D419 within the extracellular domain was sufficient to constitutively activate the KIT receptor, although high expression levels were required. Dose-dependent growth inhibition and apoptosis were observed using either the protein tyrosine kinase inhibitor imatinib mesylate (STI571, Gleevec) or by blocking the phosphoinositide-3-kinase (PI3K)–AKT pathway. Our data show that the addition of kinase inhibitors to conventional chemotherapy might be a new therapeutic option for CBF-AML expressing mutant KIT.


Blood ◽  
1994 ◽  
Vol 83 (12) ◽  
pp. 3449-3456 ◽  
Author(s):  
C Wada ◽  
S Shionoya ◽  
Y Fujino ◽  
H Tokuhiro ◽  
T Akahoshi ◽  
...  

Abstract Tumorigenesis has been shown to proceed through a series of genetic alterations involving protooncogenes and tumor-suppressor genes. Investigation of genomic instability of microsatellites has indicated a new mechanism for human carcinogenesis in hereditary nonpolyposis colorectal cancer and sporadic cancer and this instability has been shown to be related to inherited predisposition to cancer. This study was conducted to determine whether such microsatellite instability is associated with the evolution of chronic myelogenous leukemia (CML) to the blast crisis. Nineteen CML patients clinically progressing from the chronic phase to accelerated phase or blast crisis and 20 other patients in the CML chronic phase were studied. By polymerase chain reaction assay, DNAs for genomic instability in five separate microsatellites in chromosome arms 5q (Mfd27), 17p (Mfd41), 18q (DCC), 3p (CI3–9), and 8p (LPL) were examined. Differences in unrelated microsatellites of chronic and blastic phase DNAs in 14 of 19 patients (73.7%) were demonstrated. Somatic instability in five microsatellites, Mfd27, Mfd41, DCC, CI3–9, and LPL, was detected in 2 of 19 (10.5%), 8 of 19 (42.1%), 11 of 19 (57.9%), 4 of 17 (23.5%), and 4 of 17 (23.5%) cases. In 10 of 19 cases (52.6%), genetic instability in at least two of five microsatellites was observed and was categorized as replication error (RER+) phenotype. CML evolution cases with myeloid, lymphoid, and mixed phenotypes and the blast crisis and accelerated phase showed somatic instability in a number of microsatellites. No alterations in leukemic cells at the chronic phase could be detected in any microsatellites. These data indicate instability of microsatellites (RER+) but not familial predisposition to possibly be a late genetic event in the evolution of CML to blast crisis. In the microsatellite of the DCC gene, complicated alterations in band patterns caused by instability as well as loss of heterozygosity (LOH) were observed in 13 of 19 cases (68.4%): instability in 9 cases, instability plus LOH in 2 cases, and only LOH in 2 cases. These highly frequent alterations in microsatellites, including instability and LOH, suggesting that secondary events due possibly to loss of fidelity in replication and repair machinery may be significantly associated with CML evolution.


Blood ◽  
1975 ◽  
Vol 45 (4) ◽  
pp. 485-493
Author(s):  
MT Aye ◽  
JE Till ◽  
EA McCulloch

Peripheral blood cells from three patients with acute leukemic have been studied using a suspension culture method previously described.1 Cytogenetic studies in two of the patients permitted the identification of the proliferating cells in the cultures as being derived from a leukemic population. Cell separation studies using velocity sedimentation supported the concept that growth of the leukemic cells in culture is dependent on an interaction between two populations of leukemic cells.


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