Relationship between morphometric analysis of nucleolar organizer regions and cell proliferation in acute leukemias

Lorand-Metze, Irene; Carvalho, Marcelo A.; Metze, Konradin

doi:10.1002/(sici)1097-0320(19980501)32:1<51::aid-cyto7>3.0.co;2-i

Cited by 25 publications

(19 citation statements)

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“…Coomassie blue R-250 (Sigma) was the stain used. Molecular mass standards used were 200, 116, 97,66,45,31, and 21 kd from Bio-Rad. Gels were electroblotted, 55 blots were incubated with rabbit antiubiquitin antibody (Sigma; 1:200) and then goat antirabbit IgG-HRP (1:3000, Bio-Rad).…”

Section: Protein Ubiquitinationmentioning

confidence: 99%

“…31,32,45 AgNORs accumulate in cells when duplication time decreases, 32 and therefore the finding of increased AgNOR number or area of distribution indicates that cells are actively proliferating. 32,66 To our knowledge, this technique has never been used to study T-cell turnover and cell-cycle control in HIV infection.In healthy individuals, most lymphocytes contain only one AgNOR dot and express low levels of cyclin B1. Consistent with these findings, PBLs from uninfected individuals are diploid and metabolically inactive, thus confirming their G0 state.…”

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confidence: 99%

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Abnormal intracellular kinetics of cell-cycle-dependent proteins in lymphocytes from patients infected with human immunodeficiency virus: a novel biologic link between immune activation, accelerated T-cell turnover, and high levels of apoptosis

Cannavò

Paiardini

Galati

et al. 2001

Blood

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Human immunodeficiency virus (HIV)-infection is characterized by loss of CD4؉ T cells associated with high levels of immune activation, T-cell proliferation, and lymphocyte apoptosis. To investigate the role of intrinsic perturbations of cellcycle control in the immunopathogenesis of acquired immunodeficiency syndrome (AIDS), we studied the expression of cellcycle-dependent proteins in lymphocytes from HIV-infected patients. Cyclin B1 expression, Nucleolar Organizer Regions (NORs) number, and NORs area of distribution were all consistently increased in HIV-infected patients, but returned to normal after effective antiretroviral therapy, suggesting that viral replication is directly implicated in the genesis of the observed changes. Analysis of cyclin B1 intracellular turnover showed that the increased cyclin B1 expression is (1) caused by defective degradation in the presence of normal rates of synthesis, and (2) is temporally associated with decreased levels of ubiquitination. After in vitro activation of lymphocytes from healthy individuals, cyclin B1 and cdc25 expression and ubiquitination, p34 cdc2 activity, NORs morphology, and C23/nucleolin localization showed a 72-to 96-hour cyclic pattern that led to a biologic state similar to baseline. On the contrary, complex but consistent changes of the same indices followed activation of T lymphocytes from HIVinfected patients, resulting in a 5-fold increase in apoptosis. Overall, our data indicate that a profound dysregulation of cellcycle control is present in lymphocytes from HIV-infected patients. This finding may provide a novel biologic link between immune activation, accelerated lymphocyte turnover, and increased apoptosis during HIV infection. IntroductionHuman immunodeficiency virus (HIV)-infection induces a progressive depletion of CD4 ϩ T lymphocytes and high susceptibility to opportunistic infections. 1 The mechanisms of HIV-induced CD4 ϩ T-cell loss include the virus-mediated killing of infected cells as well as the death of uninfected bystander cells. 1,2 Among the indirect mechanisms that have been implicated in the lymphocyte depletion of patients with acquired immunodeficiency syndrome (AIDS), increased level of apoptosis may be significant. In HIV-infected patients, increased susceptibility to apoptotic cell death has been shown in CD4 ϩ and CD8 ϩ T lymphocytes and appears to be correlated with the general state of immune activation. [3][4][5][6] Interestingly, both increased propensity to apoptosis and overall levels of immune activation are reversed by the institution of effective anti-HIV therapy. 7,8 It is therefore likely that an abnormal relationship between T-cell activation/proliferation and occurrence of apoptosis may play a significant role in the lymphocyte depletion in the HIV-infected patient. 9,10 Lymphocyte activation in response to extrinsic signals ultimately results in either progression through the cell cycle, or activation of proapoptotic pathway(s). 11,12 Although influenced by many factors, the fate of activated T cells is e...

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Section: Protein Ubiquitinationmentioning

confidence: 99%

mentioning

confidence: 99%

Abnormal intracellular kinetics of cell-cycle-dependent proteins in lymphocytes from patients infected with human immunodeficiency virus: a novel biologic link between immune activation, accelerated T-cell turnover, and high levels of apoptosis

Cannavò

Paiardini

Galati

et al. 2001

Blood

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“…Discrete morphologic alterations of the nucleus and its substructures accompany functional and molecular changes of the cell. This is also true for benign and malignant hemopoesis [44-48]. …”

Section: Discussionmentioning

confidence: 99%

Molecular characteristics and chromatin texture features in acute promyelocytic leukemia

et al. 2012

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BackgroundAcute promyelocytic leukemia is a cytogenetically well defined entity. Nevertheless, some features observed at diagnosis are related to a worse outcome of the patients.MethodsIn a prospective study, we analyzed peripheral (PB) leukocyte count, immunophenotype, methylation status of CDKN2B, CDKN2A and TP73; FLT3 and NPM1 mutations besides nuclear chromatin texture characteristics of the leukemic cells. We also examined the relation of these features with patient’s outcome.ResultsAmong 19 cases, 4 had a microgranular morphology, 7 presented PB leukocytes >10x109/l, 2 had FLT3-ITD and 3 had FLT3-TKD (all three presenting a methylated CDKN2B). NPM1 mutation was not observed. PB leukocyte count showed an inverse relation with standard deviation of gray levels, contrast, cluster prominence, and chromatin fractal dimension (FD). Cases with FLT3-ITD presented a microgranular morphology, PB leukocytosis and expression of HLA-DR, CD34 and CD11b. Concerning nuclear chromatin texture variables, these cases had a lower entropy, contrast, cluster prominence and FD, but higher local homogeneity, and R245, in keeping with more homogeneously distributed chromatin. In the univariate Cox analysis, a higher leukocyte count, FLT3-ITD mutation, microgranular morphology, methylation of CDKN2B, besides a higher local homogeneity of nuclear chromatin, a lower chromatin entropy and FD were associated to a worse outcome. All these features lost significance when the cases were stratified for FLT3-ITD mutation. Methylation status of CDNK2A and TP73 showed no relation to patient’s survival.Conclusionin APL, patients with FLT3-ITD mutation show different clinical characteristics and have blasts with a more homogeneous chromatin texture. Texture analysis demonstrated that FLTD-ITD was accompanied not only by different cytoplasmic features, but also by a change in chromatin structure in routine cytologic preparations. Yet we were not able to detect chromatin changes by nuclear texture analysis of patients with the FTLD-TKD or methylation of specific genes.

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“…Nucleoli are very pronounced in some tumors, such as malignant melanoma, clear-cell carcinoma of the kidney, or Reed-Sternberg cells in Hodgkin's lymphoma, where they are useful diagnostic markers. Several objective and semiquantitative methods of analysis of nucleoli were developed, and these methods have been used to characterize this organelle and correlate it with the malignant or benign trait of the tumor (1)(2)(3)(4)(5)(6).…”

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Morphometry of nucleoli and expression of nucleolin analyzed by laser scanning cytometry in mitogenically stimulated lymphocytes

et al. 2001

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Relationship between morphometric analysis of nucleolar organizer regions and cell proliferation in acute leukemias

Cited by 25 publications

References 32 publications

Abnormal intracellular kinetics of cell-cycle-dependent proteins in lymphocytes from patients infected with human immunodeficiency virus: a novel biologic link between immune activation, accelerated T-cell turnover, and high levels of apoptosis

Abnormal intracellular kinetics of cell-cycle-dependent proteins in lymphocytes from patients infected with human immunodeficiency virus: a novel biologic link between immune activation, accelerated T-cell turnover, and high levels of apoptosis

Molecular characteristics and chromatin texture features in acute promyelocytic leukemia

Morphometry of nucleoli and expression of nucleolin analyzed by laser scanning cytometry in mitogenically stimulated lymphocytes

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