scholarly journals Mechanisms and Clinical Applications of Genome Instability in Multiple Myeloma

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Antonia Cagnetta ◽  
Davide Lovera ◽  
Raffaella Grasso ◽  
Nicoletta Colombo ◽  
Letizia Canepa ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Genomic Instability ◽  
Molecular Basis ◽  
Genome Instability ◽  
Dna Recombination ◽  
Clinical Applications ◽  
Response To Treatment ◽  
Chromosomal Segregation ◽  
Telomere Function ◽  
Mitotic Regulation

Ongoing genomic instability represents a hallmark of multiple myeloma (MM) cells, which manifests largely as whole chromosome- or translocation-based aneuploidy. Importantly, although it supports tumorigenesis, progression and, response to treatment in MM patients, it remains one of the least understood components of malignant transformation in terms of molecular basis. Therefore these aspects make the comprehension of genomic instability a pioneering strategy for novel therapeutic and clinical speculations to use in the management of MM patients. Here we will review mechanisms mediating genomic instability in MM cells with an emphasis placed on pathogenic mutations affecting DNA recombination, replication and repair, telomere function and mitotic regulation of spindle attachment, centrosome function, and chromosomal segregation. We will discuss the mechanisms by which genetic aberrations give rise to multiple pathogenic events required for myelomagenesis and conclude with a discussion of the clinical applications of these findings in MM patients.

scholarly journals Telomere Architecture Correlates with Aggressiveness in Multiple Myeloma

Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1969
Author(s):  
Aline Rangel-Pozzo ◽  
Pak Yu ◽  
Sadhana LaL ◽  
Yasmin Asbaghi ◽  
Luiza Sisdelli ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Disease Progression ◽  
Genomic Instability ◽  
Clinical Decision Making ◽  
Three Dimensional ◽  
Clinical Decision ◽  
Response To Treatment ◽  
Average Intensity ◽  
Patient Response ◽  
Smoldering Multiple Myeloma

The prognosis of multiple myeloma (MM), an incurable B-cell malignancy, has significantly improved through the introduction of novel therapeutic modalities. Myeloma prognosis is essentially determined by cytogenetics, both at diagnosis and at disease progression. However, for a large cohort of patients, cytogenetic analysis is not always available. In addition, myeloma patients with favorable cytogenetics can display an aggressive clinical course. Therefore, it is necessary to develop additional prognostic and predictive markers for this disease to allow for patient risk stratification and personalized clinical decision-making. Genomic instability is a prominent characteristic in MM, and we have previously shown that the three-dimensional (3D) nuclear organization of telomeres is a marker of both genomic instability and genetic heterogeneity in myeloma. In this study, we compared in a longitudinal prospective study blindly the 3D telomeric profiles from bone marrow samples of 214 initially treatment-naïve patients with either monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), or MM, with a minimum follow-up of 5 years. Here, we report distinctive 3D telomeric profiles correlating with disease aggressiveness and patient response to treatment in MM patients, and also distinctive 3D telomeric profiles for disease progression in smoldering multiple myeloma patients. In particular, lower average intensity (telomere length, below 13,500 arbitrary units) and increased number of telomere aggregates are associated with shorter survival and could be used as a prognostic factor to identify high-risk SMM and MM patients.

Dysregulated Apurinic/Apyrimidinic Endonucleases (Ape1 and Ape2) Lead to Genetic Instability in Multiple Myeloma.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1418-1418
Author(s):  
Masood A. Shammas ◽  
Hemant Koley ◽  
Sima Shah ◽  
Ramesh B. Batchu ◽  
Pierfrancesco Tassone ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Homologous Recombination ◽  
Genomic Instability ◽  
Cell Lines ◽  
Plasma Cells ◽  
Dna Recombination ◽  
Endonuclease Activity ◽  
Single Nucleotide ◽  
Genetic Changes

Abstract Multiple myeloma (MM) is associated with significant genomic instability. Homologous recombination (HR), which is elevated in MM, is considered to be responsible for this instability. As endonucleases play an important role in mediating HR, here we have evaluated the role of endonuclease in biology and progression of MM. Gene expression profile using Affymetrix U133 array showed > 2 fold elevation of Ape1 or Ape2 or both in 5 of 6 MM cell lines and 12 of 15 patient samples. Immunocytochemistry confirmed upregulation of Ape1 protein in MM cell lines. A Plasmid degradation assay confirmed significantly elevated endonuclease activity in MM cells compared to normal plasma cells. To identify the pre-dominating endonuclease activity, the degradation assay was carried out in the presence of specific endonuclease inhibitors. Harmane and methoxyamine (MA), specific inhibitors of apurinic/apyrimidinic endonucleases effectively inhibited significant endonuclease activity, while other endonuclease inhibitors ACPD and FK506 had minimal effects, confirming predominant role of apurinic/apyrimidinic endonucleases (APE) in mediating increased endonuclease activity in MM. We investigated the role of elevated APE endonuclease activity on DNA recombination and subsequent genomic re-arrangements. Using a plasmid-based assay we have previously demonstrated significantly elevated homologous recombination (HR) in MM. Inhibition of endonuclease by methoxyamine suppressed HR activity by 85 ± 2% in MM cells. Next, we evaluated whether inhibition of HR by methoxyamine can affect the frequency of acquisition of new genetic changes in MM cells using single nucleotide polymorphism (SNP) arrays (Affymetrix) as indicator of genomic instability. In three independent experiments, methoxyamine reduced the acquisition of new loss of heterozygocity (LOH) loci by an average of 71%. These data suggest that the dysregulated APE endonucleases contribute significantly to the genomic instability, acquisition of new mutations and progression of MM and provides the rationale for targeting endonuclease activity to prevent disease progression including development of drug resistance.

Molecular Basis of Genomic Instability and Progression in Multiple Myeloma: Potential Role of Apurinic (Apyrimidinic) Endonuclease.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1561-1561
Author(s):  
Masood A. Shammas ◽  
Hemanta Koley ◽  
Paola Neri ◽  
Pierfrancesco Tassone ◽  
Ramesh B. Batchu ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Genomic Instability ◽  
Cell Lines ◽  
Molecular Basis ◽  
Endonuclease Activity ◽  
Ap Endonuclease ◽  
Myeloma Cells ◽  
Genome Wide ◽  
New Mutations

Abstract Genetic instability is a prominent feature of most cancers including multiple myeloma (MM) and is responsible for ongoing accrual of mutational changes which may lead to development of drug resistance and metastasis. The molecular basis for the generation of genetic diversity in MM is therefore extremely important to understand carcinogenesis and to identify novel targets for treatment. As genomic rearrangements require excision of DNA, we hypothesized that an elevated endonuclease activity may induce recombination and subsequent genomic instability in cancer cells. We developed a plasmid degradation assay that confirmed significantly elevated endonuclease activity in MM cells compared to normal plasma cells. To identify the pre-dominating endonuclease the degradation assay was carried out in the presence of specific endonuclease inhibitors, which identified apurinic/apyrimidinic endonuclease (Ape1 and Ape2) as the predominant endonucleases in mediating increased endonuclease activity in MM. Gene expression analysis confirmed > 2 fold elevation of Ape1 or Ape2 or both in 5 of 6 MM cell lines and 12 of 15 patient samples. Both immunocytochemistry and western blot analyses confirmed upregulation of Ape1 protein in all MM cell lines and patient samples. Next, we investigated the role of elevated APE endonuclease activity in DNA recombination and subsequent genomic re-arrangements. Using a plasmid-based assay we have previously demonstrated significantly elevated homologous recombination (HR) in MM. To investigate the role of elevated AP endonuclease activity in MM, we cultured myeloma cells in the presence of methoxyamine (MX), which specifically inhibits AP endonuclease activity, and evaluated its effect on HR activity and genome-wide appearance of new mutations. Exposure of intact myeloma cells to MX resulted in > 90% inhibition of HR activity and a significant (71±10.9%; p<0.05) reduction in the appearance of new mutations compared to untreated cells, as assessed by genome-wide loss of heterozygosity (LOH) assay (Affymetrix). We also evaluated the effects of overexpression of Ape1 & 2 in normal fibroblasts which have low endonuclease activity. The transgenic upregulation of AP endonucleases (Ape1 and Ape2) in normal cells led to a significant increase in the lecombination activity, leading to a marked mutational instability as indicated by the appearance of over 20,063 and 20,143 new LOH loci per 100,000 polymorphic regions examined throughout the genome, at population doublings 25 and 50 respectively. Mutational instability was also associated with chromosomal instability confirmed by spectral karyotyping of these cells showing significant numerical and structural chromosomal abnormalities. These changes were associated with indefinite growth of cells and formation of tumors when injected in SCID mice. These data suggest that elevated AP endonuclease may be responsible for mutational and chromosomal instabilities, leading to progression of myeloma.

scholarly journals Early, On-Treatment Levels and Dynamic Changes of Genomic Instability in Circulating Tumor DNA Predict Response to Treatment and Outcome in Metastatic Breast Cancer Patients

Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1331
Author(s):  
Adriana Aguilar-Mahecha ◽  
Josiane Lafleur ◽  
Susie Brousse ◽  
Olga Savichtcheva ◽  
Kimberly A. Holden ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Metastatic Breast Cancer ◽  
Genomic Instability ◽  
Metastatic Cancer ◽  
Metastatic Breast ◽  
Circulating Tumor Dna ◽  
Response To Treatment ◽  
Breast Cancer Patients ◽  
T1 And T2 ◽  
Tumor Dna

Background: Circulating tumor DNA (ctDNA) offers high sensitivity and specificity in metastatic cancer. However, many ctDNA assays rely on specific mutations in recurrent genes or require the sequencing of tumor tissue, difficult to do in a metastatic disease. The purpose of this study was to define the predictive and prognostic values of the whole-genome sequencing (WGS) of ctDNA in metastatic breast cancer (MBC). Methods: Plasma from 25 patients with MBC were taken at the baseline, prior to treatment (T0), one week (T1) and two weeks (T2) after treatment initiation and subjected to low-pass WGS. DNA copy number changes were used to calculate a Genomic Instability Number (GIN). A minimum predefined GIN value of 170 indicated detectable ctDNA. GIN values were correlated with the treatment response at three and six months by Response Evaluation Criteria in Solid Tumours assessed by imaging (RECIST) criteria and with overall survival (OS). Results: GIN values were detectable (>170) in 64% of patients at the baseline and were significantly prognostic (41 vs. 18 months OS for nondetectable vs. detectable GIN). Detectable GIN values at T1 and T2 were significantly associated with poor OS. Declines in GIN at T1 and T2 of > 50% compared to the baseline were associated with three-month response and, in the case of T1, with OS. On the other hand, a rise in GIN at T2 was associated with a poor response at three months. Conclusions: Very early measurements using WGS of cell-free DNA (cfDNA) from the plasma of MBC patients provided a tumor biopsy-free approach to ctDNA measurement that was both predictive of the early tumor response at three months and prognostic.

scholarly journals Drug resistance in multiple myeloma associated with high in vitro incorporation of 3H-thymidine

Blood ◽  
1981 ◽  
Vol 58 (3) ◽  
pp. 471-476
Author(s):  
V Hofmann ◽  
SE Salmon ◽  
BG Durie
Keyword(s):  
Multiple Myeloma ◽  
Tumor Regression ◽  
Alkylating Agents ◽  
Cell Mass ◽  
Bone Marrow Aspiration ◽  
Labeling Index ◽  
Response To Treatment ◽  
Survival Duration ◽  
Thymidine Uptake

In multiple myeloma, tumor cell mass and labeling index correlate with subsequent survival duration, but do not predict for response to treatment. In the present study was have autoradiographically measured the incorporation of 3H-thymidine as determined by the number of grains over the myeloma nuclei in bone marrow aspiration samples. In 33/37 patients with less than 50% tumor regression or progressive disease, the pretreatment grain count was greater than or equal to 20/myeloma nucleus. Conversely, values of less than 20 were found in 27/29 patients who had greater than or equal to 50% cell mass reduction. Survival duration was significantly better than (p less than 0.001) in patients with grain counts less than 20. Sixty percent of the patients with both a low labeling index (less than or equal to 3%) and grain count (less than 20) were alive at 48 mo, whereas 15/17 patients with a high labeling index and grain count had a median survival of less than 6 mo. In a subset of 22 patients, there as a significant correlation between in vitro resistance to melphalan, adriamycin, and vincristine as tested in the myeloma stem cell colony assay system and a grain count of greater than 20. We can only speculate as to the reasons for the increased 3H-thymidine uptake by myeloma cells resistant to treatment, however, it could be associated with accumulation of excess DNA and /or increased unscheduled DNA synthesis following injury from alkylating agents.

scholarly journals EFFECTS OF GENOME INSTABILITY IN LYMPHOCYTES AND BUCCAL EPITHELIOCYTES OF CHILDREN FROM THE CITY WITH BIG PULP AND PAPER INDUSTRY

2019 ◽  
Vol 98 (12) ◽  
pp. 1392-1401
Author(s):  
V. V. Yurchenko ◽  
Faina I. Ingel ◽  
N. A. Urtseva ◽  
E. K. Krivtsova ◽  
L. V. Akhaltseva
Keyword(s):  
Genomic Instability ◽  
Genome Instability ◽  
Micronucleus Test ◽  
Paper Industry ◽  
Paper Mill ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Pulp And Paper Mill ◽  
Buccal Epithelial Cells ◽  
The City

Introduction. Analysis of literature has shown genotoxicants (mutagens and carcinogens) to be present in the atmospheric emissions of pulp and paper industry (PPI). Moreover, among PPI workers from different countries, there was identified an additional risk of cancer, which suggests its high probability among residents of the cities where the PPI is located. The recognized index of genotoxic effects is an increased level of genome instability, which is determined, in particular, in the micronucleus test. The scope of the study - the comparative analysis of the effects of genomic instability in the two tissues - blood lymphocytes cultured with Cytochalasin B, and buccal epithelial cells in the second grade school children (8-9 years old, boys and girls), whose schools were located at different distances from the pulp and paper mill. Material and methods. The study was carried out in the city of Koryazhma, the Arkhangelsk Region (42000 citizens), where the pulp and paper plant as the city-forming industry was located. For the analysis, we subdivided the territories on which the schools were located, into 3 groups according to their distance from the pulp and paper mill. The effects of genomic instability were determined by cytome analysis in the micronucleus test. Results. Cytome analysis of cultivated lymphocytes demonstrated that levels of genome instability indices (including cell frequencies with micronuclei and nucleoplasm bridges, apoptosis, as well as changes in the spectrum of cell populations) to decrease along with the rising the distance between the pulp and paper mill and schools where the children go. In buccal epithelial cells, the manifestations of genomic instability effects were less systematic, which did not allow making a definitive conclusion. At the same time, in both tests, gender differences in the results of cytome analysis were revealed (for example, the alteration of frequency of lymphocytes with genetic damage dependence on the distance between schools and the PPI was more pronounced among boys). Conclusion. According to the results of this study and taking into consideration the data of literature, we hypothesized that the discovering of gender dimorphism in the effects of genome instability may indicate the presence of toxic and/or genotoxic compounds in an environment.

scholarly journals Implementation of Accurate and Fast DNA Cytometry by Confocal Microscopy in 3D

2005 ◽  
Vol 27 (4) ◽  
pp. 225-230
Author(s):  
Lennert S. Ploeger ◽  
André Huisman ◽  
Jurryt van der Gugten ◽  
Dionne M. van der Giezen ◽  
Jeroen A. M. Beliën ◽  
...  
Keyword(s):  
Genomic Instability ◽  
Confocal Laser Scanning Microscopy ◽  
Dna Content ◽  
Laser Scanning ◽  
Clinical Applications ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Dna Cytometry ◽  
Tissue Sections

Background: DNA cytometry is a powerful method for measuring genomic instability. Standard approaches that measure DNA content of isolated cells may induce selection bias and do not allow interpretation of genomic instability in the context of the tissue. Confocal Laser Scanning Microscopy (CLSM) provides the opportunity to perform 3D DNA content measurements on intact cells in thick histological sections. Because the technique is technically challenging and time consuming, only a small number of usually manually selected nuclei were analyzed in different studies, not allowing wide clinical evaluation. The aim of this study was to describe the conditions for accurate and fast 3D CLSM cytometry with a minimum of user interaction to arrive at sufficient throughput for pilot clinical applications. Methods: Nuclear DNA was stained in 14 μm thick tissue sections of normal liver and adrenal stained with either YOYO-1 iodide or TO-PRO-3 iodide. Different pre-treatment strategies were evaluated: boiling in citrate buffer (pH 6.0) followed by RNase application for 1 or 18 hours, or hydrolysis. The image stacks obtained with CLSM at microscope magnifications of ×40 or ×100 were analyzed off-line using in-house developed software for semi-automated 3D fluorescence quantitation. To avoid sectioned nuclei, the top and bottom of the stacks were identified from ZX and YZ projections. As a measure of histogram quality, the coefficient of variation (CV) of the diploid peak was assessed. Results: The lowest CV (10.3%) was achieved with a protocol without boiling, with 1 hour RNase treatment and TO-PRO-3 iodide staining, and a final image recording at ×60 or ×100 magnifications. A sample size of 300 nuclei was generally achievable. By filtering the set of automatically segmented nuclei based on volume, size and shape, followed by interactive removal of the few remaining faulty objects, a single measurement was completely analyzed in approximately 3 hours. Conclusions: The described methodology allows to obtain a largely unbiased sample of nuclei in thick tissue sections using 3D DNA cytometry by confocal laser scanning microscopy within an acceptable time frame for pilot clinical applications, and with a CV small enough to resolve smaller near diploid stemlines. This provides a suitable method for 3D DNA ploidy assessment of selected rare cells based on morphologic characteristics and of clinical samples that are too small to prepare adequate cell suspensions.

scholarly journals Whole-Body Low-Dose Multidetector-Row CT in Multiple Myeloma: Guidance in Performing, Observing, and Interpreting the Imaging Findings

Life ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1320
Author(s):  
Antonio Pierro ◽  
Alessandro Posa ◽  
Costanzo Astore ◽  
Mariacarmela Sciandra ◽  
Alessandro Tanzilli ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Low Dose ◽  
Plasma Cells ◽  
Traditional Approach ◽  
Response To Treatment ◽  
Whole Body ◽  
Newly Diagnosed ◽  
Low Dose Ct ◽  
Lytic Lesions ◽  
Total Body

Multiple myeloma is a hematological malignancy of plasma cells usually detected due to various bone abnormalities on imaging and rare extraosseous abnormalities. The traditional approach for disease detection was based on plain radiographs, showing typical lytic lesions. Still, this technique has many limitations in terms of diagnosis and assessment of response to treatment. The new approach to assess osteolytic lesions in patients newly diagnosed with multiple myeloma is based on total-body low-dose CT. The purpose of this paper is to suggest a guide for radiologists in performing and evaluating a total-body low-dose CT in patients with multiple myeloma, both newly-diagnosed and in follow-up (pre and post treatment).

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