Response of granulocyte-committed progenitors from patients with chronic myeloid leukemia to humoral regulators release by macrophages in agar diffusion chamber culture

We investigated the responsiveness of granulocyte-committed progenitors (CFU-G/D) from patients with chronic myeloid leukemia (CML) and healthy subjects to stimulating and inhibiting activities released by murine macrophages in diffusion chamber culture. CFU-G/D from CML demonstrate a normal response to macrophage-derived stimulation. The responsiveness of CFU-G/D from patients with CML to indomethacin-sensitive inhibition was significantly suppressed. In this regard no difference between CFU-G/D from bone marrow and blood of patients with CML could be observed. Colonies formed both by CFU-G/D from healthy subjects and CML consisted exclusively of cells of granulocyte line: from myeloblasts up to polymorphonuclear granulocytes. Similar cellular composition of colonies could be noted during macrophage-derived stimulation and inhibition of CFU-G/D growth. In conclusion, we have demonstrated that CML CFU-G/D which proliferate and differentiate in diffusion chamber culture show a normal response to macrophage-derived stimulation but are less sensitive to indomethacin-dependent inhibition.     

Chemiluminescence,suppression and cytotoxicity in peripheral blood mononuclear cells from solid tumor cancer patients

Summary Chemiluminescence, indomethacin-sensitive suppression, and adherent cell cytotoxicity were measured in peripheral blood mononuclear cells (PBMC) from normal subjects and solid tumor cancer patients. These functions were found to be differentially affected by malignant disease. In cancer patients with disseminated disease, indomethacin-sensitive suppression and chemiluminescence emission were increased to a level significantly higher than normal without a concurrent increase in adherent cell cytotoxic function. In cancer patients with at most minimum residual diseases, the levels of chemiluminescence, indomethacin-sensitive suppression, and adherent cell cytotoxicity found were comparable to those of the normal study population. In vitro stimulation of cells from patients with disseminated disease by phorbol myristic acetate (PMA) increased chemiluminescence overcame the suppressive effects of indomethacin-sensitive suppressor cells, and increased adherent cell cytotoxicity; in cells from patients with at most minimum residual disease, PMA increased chemiluminescence and cytotoxicity without influencing the activity of indomethacin-sensitive suppressor cells. Vaccination of lung cancer patients with Freund's complete adjuvant or Freund's complete adjuvant plus tumor antigen extracts led to increased levels of chemiluminescence and increased levels of adherent cell cytotoxicity without altering indomethacin-sensitive regulatory cell function.     

Dasatinib preferentially induces apoptosis by inhibiting Lyn kinase in nilotinib-resistant chronic myeloid leukemia cell line

Nilotinib is approved for treatment of newly diagnosed chronic myeloid leukemia (CML) and it is shown superiority over imatinib in first-line treatment for patients of CML. In this study, we established a nilotinib-resistant cell line, K562NR, and evaluated the resistance to nilotinib and efficacy of dasatinib. We found activation of Lyn plays a dominant role in survival of the nilotinib-resistant cell line. We found dasatinib induces the apoptosis of nilotinib-resistant cells and inhibits Lyn kinase activity. This novel nilotinib-resistant CML cell line may help to explore novel therapy for CML.     

Role of hematopoietic cells-precursors in the regeneration of hematopoiesis after cytostatic action]

Cyclophosphamide was injected at a dose of 150 mg/kg once to CBA mice and caused expressed hypoplasia of bone marrow hemopoiesis (decreased myelokaryocyte count, CFU-S and CFU-D) from day 1 of the experiment. The rise of CFU-S (8) and CFU-S (12) to a baseline level was noted on day 4 (the time of intensive regeneration processes), whereas CFU-D levels did not change. It is suggested that cytostatic action may trigger "shunt" hemopoiesis mechanisms which enhance differentiation of primitive hemopoietic cells and proliferative activity of mature hemopoietic elements.     

Influence of mature and immature myeloid cells on lymphocyte reactivity in chronic myelocytic leukemia

Summary Earlier studies have shown anergy in chronic myeloid leukemia (CML), and it is known that myeloid cells influence lymphocyte responses. Therefore, lymphocytes from CML patients who had received no cytostatics for 2 weeks were stimulated in 89 tests with PHA and ConA. In 39 control tests, normal lymphocytes were used.Lymphocytes from CML patients were significantly less (p<0.05) markedly stimulated than normal ones. Lymphocytes from CML patients with more than 10×10⁹ white blood cells (WBC) per liter blood were inhibited to a greater degree than those from patients with a normal WBC count.When normal lymphocytes were stimulated with PHA in the presence of mononuclear cells from the blood of CML patients (mostly leukemic myelocytes), their response was significantly (p<0.05) inhibited. Inhibition with leukemic myelocytes was significantly (p<0.05) greater than that with mature granulocytes from CML patients. The latter did not seem to have an inhibitory effect.We suggest that patients with manifest CML are anergic to some extent because leukemic myelocytes have a suppressor effect.Visiting scientist and Anna Villa Rusconi Fellow, on secondment from Institute of Medical Pathology, University of Ferrara, Italy     

Detection of an antigen, associated with cells during the blast crisis of chronic myeloleukemia, in a cytotoxic test using xenogenic antibodies]

The immune antimyeloblast serum (AMS) was obtained from horses immunized with white blood cells from patients suffering from chronic myeloid leukemia (CML) at the blast crisis stage; the serum was completely absorbed with normal red blood cells and white blood cells (WBC). The absorbed antiserum remained cytotoxic to blast cells from 20 of 42 patients with CML at the blast crisis stage. AMS failed to react with the WBC from patients with CML in its chronic phase, and from patients with other types of leukemia Morphological studies indicated a possibility of identification of the antigen associated with myeloblasts from the blood of patients with CML blast crisis, by means to AMS.     

Natural killer cell immunodeficiency in patients with chronic myelogenous leukemia. IV. Interleukin-1 deficiency, gamma-interferon deficiency and the restorative effects of short-term culture in the presence of interleukin-2 on natural killer cytotoxicity, natural killer-target binding and production of natural killer cytotoxic factor

We report herein that defective natural killer (NK) cell cytotoxicity, NK cytotoxic factor (NKCF) production and NK target binding ability of patients with chronic myelogenous leukemia (CML) are functionally restorable after short-term culture (less than 1 week) with recombinant interleukin-2 (rIL-2). We have previously reported that, despite normal to increased numbers of CD16+ large granular lymphocytes, fluorescence-activated-cell-sorted NK cells from CML patients are profoundly defective in NK cell activity and are unable to lyse the CML blast-crisis-derived, NK-sensitive target K562. Since we and others have also previously shown that the defective NK cytotoxicity from CML patients is restorable after 1-4 weeks of incubation with rIL-2, we therefore deemed it important to study the kinetics of IL-2-mediated NK restoration at earlier time intervals (less than 1 week). In the present report, we have demonstrated a significant restoration of NK cell cytotoxicity in CML patients against K562 after 5 days of short-term culture with rIL-2. In addition, recovery of NKCF production and restoration of target-binding capacity to normal levels by NK cells from CML patients were also observed after short-term (less than 1 week) rIL-2 treatment. Finally, we have demonstrated in the present report that adherent cells and peripheral-blood lymphoid cells from CML patients, as compared to normal controls, are unable to produce IL-1 beta and interferon-gamma, respectively, after stimulation with phorbol myristate acetate (IL-1 beta) and phytohemagglutinin-M (interferon-gamma).     

The BCR/ABL transgene causes abnormal NK cell differentiation and can be found in circulating NK cells of advanced phase chronic myelogenous leukemia patients.

NK cells from the blood of chronic myelogenous leukemia (CML) patients are progressively decreased in number as the disease progresses from chronic phase to blast crisis. We hypothesize that BCR/ABL may be directly responsible by interfering with NK cell differentiation. CD34(+)HLA-DR(+) cells from CML patients were studied for their capacity to differentiate into NK cells. The NK cell cloning frequency was significantly decreased from CML CD34(+)HLA-DR(+) cells compared with cells from normal donors, yet CD34(+)HLA-DR(+) cells gave rise to BCR/ABL(+) NK cells in some patients. This finding prompted us to further investigate circulating NK cells from the blood of CML patients. CD56(+)CD3(-) NK cells were sorted from CML patients and examined by fluorescence in situ hybridization (FISH). In contrast to chronic phase CML, significant numbers of NK cells from advanced phase CML patients were BCR/ABL(+), whereas T cells were always BCR/ABL(-) regardless of the disease stage. To test the effects of BCR/ABL as the sole genetic abnormality, BCR/ABL was transduced into umbilical cord blood CD34(+) cells, and NK development was studied. p210-enhanced green fluorescence protein-transduced cells gave rise to significantly decreased numbers of NK cells compared with enhanced green fluorescence protein transduction alone. In addition, the extrinsic addition of BCR/ABL-transduced autologous CD34(+) cells suppressed the NK cell differentiation of normal umbilical cord blood CD34(+)CD38(-) cells. This study provides the first evidence that BCR/ABL is responsible for the altered differentiation of NK cells and that the NK cell lineage can be involved with the malignant clone in advanced stage CML.     

Increased levels of vascular endothelial growth factor and advanced glycation end products in aqueous humor of patients with diabetic retinopathy.

Clinical studies have shown a relationship between diabetic retinopathy and vascular endothelial growth factor (VEGF) levels in ocular fluid. Advanced glycation end products (AGEs) have been implicated in diabetes complications, including diabetic retinopathy. Nepsilon-(carboxymethyl) lysine (CML) is a glycoxidation product that may be a marker of oxidative stress. In this study, we used enzyme-linked immunosorbent assays to determine the levels of VEGF, non-CML AGE and CML in the aqueous humor and serum of 82 Japanese patients with type 2 diabetes and 60 non-diabetic subjects. VEGF, non-CML AGE, and CML concentrations in aqueous humor and serum were then compared with the severity of diabetic retinopathy. Immunohistochemical detection analysis of non-CML AGE and CML was also performed using retinal tissues from patients with progressive diabetic retinopathy. Aqueous levels of VEGF, non-CML AGE and CML increased along with the progression of diabetic retinopathy compared to age-matched controls. After coagulation therapy, the VEGF, non-CML AGE, and CML levels were significantly reduced. Immunostaining showed diffuse co-localization of non-CML AGE and CML around microvessels and in the glial cells of proliferative membranes from patients with progressive diabetic retinopathy. These findings suggest that glycation and glycoxidation reactions (or oxidation, as revealed by CML) may contribute to both the onset and progression of diabetic retinopathy.     

Evaluation of monocyte-derived dendritic cells, T regulatory and Th17 cells in chronic myeloid leukemia patients treated with tyrosine kinase inhibitors

Immunotherapy with dendritic cells (DC) may constitute a new and advantageous option for patients with chronic myeloid leukemia (CML) who respond to therapy with tyrosine kinase inhibitors (TKI), but do not reach complete cytogenetic or molecular remission. In this study, we evaluated the immunophenotype of DC generated from monocytes (Mo-DC) of patients with CML and the influence of TKI therapy on the results of CML-DC generation. We also measured the percentages of T regulatory cells (Tregs) as well as Th17 cells in 19 untreated patients suffering from CML, and in 28 CML patients treated with TKI. We found that DC can be reliably generated from the peripheral blood CD14+ cells of untreated CML patients. But we observed a persistent expression of CD14 monocyte marker on DC from CML patients, together with lower percentages of Mo-DC with expression of CD1a (p = 0.002), CD80 (p = 0.0005), CD83 (p = 0.0004), and CD209 (p = 0.02) compared to healthy donors. There was an adverse correlation between WBC count and the percentage of Mo-DC with co-expression of CD80 and CD86 (R = -0.63; p = 0.03). In patients treated with TKI, we observed higher efficacy of DC generation in seven-day cultures, compared to untreated patients. Expression of CD209 on DC was higher in patients treated with TKI (0.02). The duration of TKI therapy correlated adversely with MFI for CD1a (R = -0.49; p = 0.006) and positively with MFI for CD83 (R = 0.63; p = 0.01). Percentages of CD4+CD25highFoxP3+ cells (p = 0.0002) and Th17 cells (p = 0.02) were significantly higher in untreated CML patients compared to healthy controls. There was a significant correlation between the percentage of Treg cells and the percentage of peripheral blood basophiles (R = 0.821; p = 0.02). There were no changes in Tregs or Th17 cell percentages in CML patients after six months of TKI therapy. However, the expression of intracellular IL-17 in Th17 cells correlated negatively with the time of TKI therapy in the whole group of treated patients (R = -0.516; p = 0.04). We noted a correlation between IL-6 serum level and peripheral blood WBC count (R = 0.492; p = 0.04). There was also an inverse correlation between the serum level of IL-6 and the duration of TKI therapy (R = -0.66; p = 0.03). Taken together, our data shows that mature DC can be generated from CML patients treated with TKI, and that the yield of Mo-DC is higher in patients treated with TKI than in patients with active disease. This should encourage further trials with DC immunotherapy in patients with cytogenetic response after TKI therapy. We also found increased frequencies of T regulatory and Th17 cells in CML patients, which might suggest their potential role in immunity against this disease. Further studies are needed to determine if manipulation of these cell populations might improve the results of DC immunotherapy.     

Increased accumulation of the glycoxidation product Nepsilon-(carboxymethyl)lysine in hearts of diabetic patients: generation and characterisation of a monoclonal anti-CML antibody

Heart failure is a condition closely linked to diabetes. Hyperglycaemia amplifies the generation of a major advanced glycation end product Nepsilon-(carboxymethyl)lysine (CML), which has been associated with the development of vascular and inflammatory complications. An increased accumulation of CML in hearts of diabetic patients may be one of the mechanisms related to the high risk of heart failure. Therefore, we investigated the localization of CML in diabetic hearts. To investigate the presence and accumulation of CML in tissues, a monoclonal anti-CML antibody was generated and characterised. With this novel monoclonal antibody against CML, the localization of CML was investigated by immunohistochemistry, in heart tissue of controls (n = 9) and heart tissue of diabetic patients (n = 8) without signs of inflammation or infarction. In addition, in the same subjects we studied the presence of CML in renal and lung tissues. CML staining was approximately sixfold higher in hearts from diabetic patients as compared to control hearts (2.0 +/- 0.3 and 0.3 +/- 0.2 A.U., respectively, P < 0.01). CML deposition was localized in the small intramyocardial arteries in endothelial cells and smooth muscle cells, but not in cardiomyocytes. These arteries did not show morphological abnormalities. The intensity of staining between arteries at the epicardial, midcardial and endocardial side did not vary significantly within patients. In renal tissues, CML staining was most prominent in tubules and in atherosclerotic vessels, without differences in intensity between controls and diabetic patients. In non-infected lungs, no CML was detected. In conclusion, CML adducts are abundantly present in small intramyocardial arteries in the heart tissue of diabetic patients. The accumulation of CML in diabetic hearts may contribute to the increased risk of heart failure in hyperglycaemia.     

MYC in chronic myeloid leukemia: induction of aberrant DNA synthesis and association with poor response to imatinib

Untreated chronic myeloid leukemia (CML) progresses from chronic phase to blastic crisis (BC). Increased genomic instability, deregulated proliferation, and loss of differentiation appear associated to BC, but the molecular alterations underlying the progression of CML are poorly characterized. MYC oncogene is frequently deregulated in human cancer, often associated with tumor progression. Genomic instability and induction of aberrant DNA replication are described as effects of MYC. In this report, we studied MYC activities in CML cell lines with conditional MYC expression with and without exposure to imatinib, the front-line drug in CML therapy. In cells with conditional MYC expression, MYC did not rescue the proliferation arrest mediated by imatinib but provoked aberrant DNA synthesis and accumulation of cells with 4C content. We studied MYC mRNA expression in 66 CML patients at different phases of the disease, and we found that MYC expression was higher in CML patients at diagnosis than control bone marrows or in patients responding to imatinib. Further, high MYC levels at diagnosis correlated with a poor response to imatinib. MYC expression did not directly correlate with BCR-ABL levels in patients treated with imatinib. Overall our study suggests that, as in other tumor models, MYC-induced aberrant DNA synthesis in CML cells is consistent with MYC overexpression in untreated CML patients and nonresponding patients and supports a role for MYC in CML progression, possibly through promotion of genomic instability.     

Exosomes derived from imatinib-resistant chronic myeloid leukemia cells mediate a horizontal transfer of drug-resistant trait by delivering miR-365

Chronic myeloid leukemia (CML) is a malignant disorder of hematopoietic stem/progenitor cells. Majority of patients can be effectively treated with tyrosine kinase inhibitors (TKIs) such as imatinib, but a portion of patients will develop drug resistance. Accumulated evidences have identified exosomes in cancer as promoters of tumor progression. Herein, we found that exosomes derived from imatinib resistant CML cells can be internalized into sensitive CML cells and confer drug-resistance traits. We also demonstrated a significant higher level of miR-365 in exosomes derived from drug-resistant CML cells compared with those from sensitive ones using microarray and qRT-PCR. The imatinib sensitive CML cells transfected with pre-miR-365 displayed lower chemosensitivity and apoptosis rate compared with controls. We further confirmed that exosomal transfer of miR-365 induced drug resistance by inhibiting expression of pro-apoptosis protein in sensitive CML cells. In conclusion, our study reveals that exosomes mediate a horizontal transfer of drug-resistant trait in chronic myeloid leukemia cell by delivering miR-365.     

Activity of cyclic nucleotide phosphodiesterases in granulocytes of chronic myelogenous leukemia (CML). A preliminary report

Cyclic 3':5'-adenosinmonophosphate phosphodiesterase (cAMP-PDE), high KM value type isoenzyme, and cyclic 3':5'-guanosino-monophosphate phosphodiesterase (cGMP-PDE), high KM value type isoenzyme, were determined in granulocytes of patients with chronic myelogenous leukemia (CML) in the chronic phase of the disease. Granulocyte cAMP-PDE activity was similar in the general group of CML patients to that in normal granulocytes; the cGMP-PDE, however, was somewhat higher. By dividing the CML general group into the "low leukocyte count" subgroup including granulocytes of patients with WBC number ranging from 10,300 to 40,000 per microliter (mean 22,000 per microliter), and the "high leukocyte count" subgroup including patients with leukocyte count above 40,000 per microliter (mean 67,000) remarkable differences in the activities of cyclic nucleotide phosphodiesterases between these subgroups could be found: cAMP-PDE activity for the high leukocyte count subgroups was significantly higher than for that in normals, and in CML-low leukocyte count subgroup. On the other hand, cGMP-PDE activity in granulocytes of the high leukocyte count subgroup was found to be remarkably lower than that in normals, in the low leukocyte count subgroup and general CML group. In CML patients the ratio of cAMP-PDE activity to cGMP-PDE activity was always considerably higher than that in controls. The obtained results suggest CML granulocytes to differ from normal ones in respect to their control of intracellular cyclic nucleotide levels. This difference is related to the accumulation of CML granulocytes.     

Splenic monocyte-macrophage dependent suppression of autologous granulocyte-progenitors growth in Hodgkin's disease

The studies described compare the effect of spleen cell suspensions from 11 patients with Hodgkin's disease (HD) and 5 healthy subjects on the clonal growth of autologous marrow granulopoietic progenitors in diffusion chamber culture (CFU-G/D). Adherent monocyte/macrophage fraction of splenocytes from HD suppresses the proliferation of autologous CFU-G/D. This inhibition was mediated by an indomethacin-sensitive humoral factor(s). Non-adherent lymphoid cells stimulated myeloid colony formation. Dose response curves demonstrated a markedly increased inhibitory-activity production already by low numbers of splenic monocytes/macrophages from HD whereas a comparable counts of monocytes/macrophages from the spleens of healthy subjects stimulated the CFU-G/D growth. These results may suggest a possible activation of splenic monocytes/macrophages with an enhanced prostaglandin-mediated suppressor activity release for local granulocytopoiesis in the spleens of patients with HD.     

TGF-beta1-induced PI3K/Akt/NF-kappaB/MMP9 signalling pathway is activated in Philadelphia chromosome-positive chronic myeloid leukaemia hemangioblasts

Overwhelming evidence from chronic myeloid leukaemia (CML) research indicates that patients harbour quiescent CML stem cells that are responsible for blast crisis. While the haematopoietic stem cell (HSC) origin of CML was first suggested over 30 years ago, recently CML-initiating cells beyond HSCs are also being investigated. We have previously isolated fetal liver kinase-1-positive (Flk1(+)) cells carrying the BCR/ABL fusion gene from the bone marrow of Philadelphia chromosome-positive (Ph(+)) patients with hemangioblast property. Here, we show that these cells behave abnormally comparing with the hemangioblasts in healthy donors. These Ph(+) putative CML hemangioblast up-regulated TGF-β1 and result in activating matrix metalloproteinase-9 to enhance s-KitL and s-ICAM-1 secretion. Further studies showed that phosphatidylinositol-3 kinase (PI3K)/Akt/nuclear factor-κB signalling pathway was involved in CML pathogenesis. These findings provide direct evidence for the first time that hemangioblasts beyond HSCs play a critical role in the progression of CML.