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1.
J Pathol ; 258(2): 121-135, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35723032

RESUMO

Tumour-associated macrophages (TAMs) abundantly infiltrate high-grade gliomas and orchestrate immune response, but their diversity in isocitrate dehydrogenase (IDH)-differential grade 4 gliomas remains largely unknown. This study aimed to dissect the transcriptional states, spatial distribution, and clinicopathological significance of distinct monocyte-derived TAM (Mo-TAM) and microglia-derived TAM (Mg-TAM) clusters across glioblastoma-IDH-wild type and astrocytoma-IDH-mutant-grade 4 (Astro-IDH-mut-G4). Single-cell RNA sequencing was performed on four cases of human glioblastoma and three cases of Astro-IDH-mut-G4. Cell clustering, single-cell regulatory network inference, and gene set enrichment analysis were performed to characterize the functional states of myeloid clusters. The spatial distribution of TAM subsets was determined in human glioma tissues using multiplex immunostaining. The prognostic value of different TAM-cluster specific gene sets was evaluated in the TCGA glioma cohort. Profiling and unbiased clustering of 24,227 myeloid cells from glioblastoma and Astro-IDH-mut-G4 identified nine myeloid cell clusters including monocytes, six Mo/Mg-TAM subsets, dendritic cells, and proliferative myeloid clusters. Different Mo/Mg-TAM clusters manifest functional and transcriptional diversity controlled by specific regulons. Multiplex immunostaining of subset-specific markers identified spatial enrichment of distinct TAM clusters at peri-vascular/necrotic areas in tumour parenchyma or at the tumour-brain interface. Glioblastoma harboured a substantially higher number of monocytes and Mo-TAM-inflammatory clusters, whereas Astro-IDH-mut-G4 had a higher proportion of TAM subsets mediating antigen presentation. Glioblastomas with a higher proportion of monocytes exhibited a mesenchymal signature, increased angiogenesis, and worse patient outcome. Our findings provide insight into myeloid cell diversity and its clinical relevance in IDH-differential grade 4 gliomas, and may serve as a resource for immunotherapy development. © 2022 The Pathological Society of Great Britain and Ireland.


Assuntos
Astrocitoma , Neoplasias Encefálicas , Glioblastoma , Glioma , Astrocitoma/genética , Astrocitoma/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Glioblastoma/genética , Glioblastoma/patologia , Glioma/genética , Humanos , Isocitrato Desidrogenase/genética , Mutação , Macrófagos Associados a Tumor
2.
Lab Invest ; 102(12): 1304-1313, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35882906

RESUMO

Glioma progression is accompanied with increased tumor tissue stiffness, yet the underlying mechanisms are unclear. Herein, we employed atomic force microscopy analysis to show that tissue stiffness was higher in isocitrate dehydrogenase (IDH)-wild type gliomas than IDH-mutant gliomas. Bioinformatic analyses revealed that tissue inhibitor of metalloproteinase-1 (TIMP1) was one of the preferentially upregulated genes in IDH-wild type gliomas as compared to IDH-mutant gliomas, and its higher expression indicated worse prognosis of glioma patients. TIMP1 intensity determined by immunofluorescence staining on glioma tissues positively correlated with glioma tissue stiffness. Mechanistically, TIMP1 expression was positively correlated with the gene expression of two predominant extracellular matrix components, tenascin C and fibronectin, both of which were also highly expressed in IDH-wild type gliomas. By introducing IDH1-R132H-containing vectors into human IDH1-wild type glioma cells to obtain an IDH1-mutant cell line, we found that IDH1 mutation increased the TIMP1 promoter methylation through methylation-specific PCR. More importantly, IDH1-R132H mutation decreased both the expression of TIMP1, fibronectin, tenascin C, and the tumor tissue stiffness in IDH1-mutant glioma xenografts in contrast to IDH1-wild type counterparts. Moreover, TIMP1 knockdown in IDH-wild type glioma cells inhibited the expression of tenascin C and fibronectin, and decreased tissue stiffness in intracranial glioma xenografts. Conclusively, we revealed an IDH mutation status-mediated mechanism in regulating glioma tissue stiffness through modulating TIMP1 and downstream extracellular matrix components.


Assuntos
Neoplasias Encefálicas , Glioma , Humanos , Isocitrato Desidrogenase/genética , Isocitrato Desidrogenase/metabolismo , Fibronectinas/genética , Neoplasias Encefálicas/metabolismo , Tenascina/genética , Inibidor Tecidual de Metaloproteinase-1/genética , Glioma/metabolismo , Mutação , Matriz Extracelular/metabolismo
3.
Lab Invest ; 102(7): 722-730, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34963686

RESUMO

Glioma stem cells (GSCs) are self-renewing tumor cells with multi-lineage differentiation potential and the capacity of construct glioblastoma (GBM) heterogenicity. Mitochondrial morphology is associated with the metabolic plasticity of GBM cells. Previous studies have revealed distinct mitochondrial morphologies and metabolic phenotypes between GSCs and non-stem tumor cells (NSTCs), whereas the molecules regulating mitochondrial dynamics in GBM cells are largely unknown. Herein, we report that carnitine palmitoyltransferase 1A (CPT1A) is preferentially expressed in NSTCs, and governs mitochondrial dynamics and GSC differentiation. Expressions of CPT1A and GSC marker CD133 were mutually exclusive in human GBMs. Overexpression of CPT1A inhibited GSC self-renewal but promoted mitochondrial fusion. In contrast, disruption of CPT1A in NSTCs promoted mitochondrial fission and reprogrammed NSTCs toward GSC feature. Mechanistically, CPT1A overexpression increased the phosphorylation of dynamin-related protein 1 at Ser-637 to promote mitochondrial fusion. In vivo, CPT1A overexpression decreased the percentage of GSCs, impaired GSC-derived xenograft growth and prolonged tumor-bearing mice survival. Our work identified CPT1A as a critical regulator of mitochondrial dynamics and GSC differentiation, indicating that CPT1A could be developed as a molecular target for GBM cell-differentiation strategy.


Assuntos
Neoplasias Encefálicas , Carnitina O-Palmitoiltransferase , Glioblastoma , Glioma , Dinâmica Mitocondrial , Animais , Neoplasias Encefálicas/metabolismo , Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/metabolismo , Linhagem Celular Tumoral , Glioblastoma/metabolismo , Glioma/metabolismo , Humanos , Camundongos , Células-Tronco Neoplásicas/metabolismo
4.
Tumour Biol ; 35(4): 3731-41, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24318973

RESUMO

Gastric carcinoma (GC) is one of the most common malignancies worldwide. To identify the candidate carcinoma-related biomarker in GC, comparative proteome technique was performed in resected GC tissues and matched adjacent non-cancerous gastric tissues (ANGT). As a result, S100A2 was successfully identified to be down-regulated significantly in GC compared with ANGT. Western blot analysis validated decreased expression of S100A2, and its expression level was related with the degree of tumor differentiation and status of lymph node metastasis in GC. Furthermore, immunohistochemistry analysis showed S100A2 down-expression was significantly associated with poor differentiation (P < 0.05), advanced depth of invasion (P < 0.05) and lymph node metastasis (P < 0.05) in GC. Kaplan-Meier curves showed that the relapse-free probability and the overall survival rate were significantly decreased with S100A2 expression decreasing (P < 0.05). Cox regression analysis indicated S100A2 down-expression was a negative independent prognostic biomarker for GC. A supplement of S100A2 protein by S100A2 expression vector significantly decreased the number of invaded cancer cells MGC-803. However, knockdown of S100A2 expression by siRNA interference compromised the invasion ability of MGC-803 cells. Moreover, S100A2 negatively regulated MEK/ERK signaling pathway, and activation of this signaling pathway by S100A2 down-regulation increased in vitro invasion of MGC-803 cells. In conclusion, this study demonstrated the clinical significance of S100A2 expression in GC, and loss of S100A2 expression contributes to GC development and progression. Therefore, the determination of S100A2 expression levels contributes to predict the outcome of GC patients.


Assuntos
Fatores Quimiotáticos/fisiologia , Proteínas S100/fisiologia , Neoplasias Gástricas/patologia , Adulto , Idoso , Fatores Quimiotáticos/análise , Fatores Quimiotáticos/genética , Feminino , Humanos , Imuno-Histoquímica , Sistema de Sinalização das MAP Quinases , Masculino , Pessoa de Meia-Idade , Quinases de Proteína Quinase Ativadas por Mitógeno/fisiologia , Invasividade Neoplásica , Prognóstico , Proteínas S100/análise , Proteínas S100/genética , Estômago/química , Neoplasias Gástricas/mortalidade
5.
J Res Med Sci ; 18(8): 704-6, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24379848

RESUMO

BACKGROUND: The objective of this study is to optimize the effective dose of heparin and ligustrazine hydrochloride injection (LHI) for drug combination. MATERIALS AND METHODS: The animal clinical study of LHI was performed by the rat's model of induced arteriovenous shunt thrombosis. Experimental animals were grouped into several groups and separately treated with both LHI (20, 40, 80 mg/kg, i.p.) and heparin (60, 55, and 50 U/kg; 5000 U/ml; Sigma, i.v). The study had used thrombus weight, protein concentration in thrombus homogenate, inhibition rate of thrombosis, and plasma anti-thrombin activity as indications. RESULTS: The group combination (50, 80) got the result of 100% antithrombotic activity with 0 ± 0 mg of thrombus weight, 14 ± 3 µg/ml of protein concentration in thrombus homogenate and 1.5 ± 0.04 U/ml of plasma anti-thrombin activity. Its anti-thrombotic effect was much better than individual groups treated with LHI in a dose of 0 mg/kg and group of combination (0, 80) (P < 0.05) while antithrombotic effect of 55 and 60 U/kg heparin alone was only 37-58%. Therefore, the group of combination (50, 80) was optimal for 100% antithrombotic activity. CONCLUSION: Optimal combined doses of LHI and heparin preventing blood coagulation were determined and the results were available. It may give some hint for the further clinical application on human.

6.
World J Clin Cases ; 11(28): 6688-6697, 2023 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-37901001

RESUMO

BACKGROUND: Antinuclear antibodies (ANAs) are crucial in diagnosing autoimmune diseases, mainly systemic lupus erythematosus (SLE). This study aimed to compare the performance of chemiluminescence assay (CLIA) and line immunoassay (LIA) in detecting ANAs in patients with autoimmune diseases, evaluate their diagnostic accuracy for SLE, and develop a novel diagnostic model using CLIA-detected antibodies for SLE. Specimens from patients with autoimmune diseases and physical examination specimens were collected to parallel detect specific antibodies. Individual antibodies' diagnostic performance and a model combining multiple antibodies were assessed. The findings provide valuable insights into improving the diagnosis of SLE through innovative approaches. AIM: To compare the performance of CLIA and LIA in detecting ANAs in patients with autoimmune diseases, assess their accuracy for SLE, and develop a novel diagnostic model using CLIA-detected antibodies for SLE. METHODS: Specimens have been obtained from 270 patients with clinically diagnosed autoimmune disorders, as well as 130 physical examination specimens. After that, parallel detection of anti-double-stranded DNA (dsDNA) antibody, anti-histone (Histone) antibody, anti-nucleosome (Nuc) antibody, anti-Smith (Sm) antibody, anti-ribosomal P protein (Rib-P) antibody, anti-sicca syndrome A (Ro60) antibody, anti-sicca syndrome A (Ro52) antibody, anti-sicca syndrome (SSB) antibody, anti-centromere protein B (Cenp-B) antibody, anti-DNA topoisomerase 1 (Scl-70) antibody, anti-histidyl tRNA synthetase (Jo-1) antibody, and anti-mitochondrial M2 (AMA-M2) antibody was performed using CLIA and LIA. The detection rates, compliance rates, and diagnostic performance for SLE were compared between the two methodologies, followed by developing a novel diagnostic model for SLE. RESULTS: CLIA and LIA exhibited essentially comparable detection rates for anti-dsDNA antibody, anti-Histone antibody, anti-Nuc antibody, anti-Sm antibody, anti-Rib-P antibody, anti-Ro60 antibody, anti-Ro52 antibody, anti-SSB antibody, anti-Cenp-B antibody, anti-DNAScl-70 antibody, anti-Jo-1 antibody and anti-AMA-M2 antibody (P > 0.05). The two methods displayed identical results for the detection of anti-dsDNA antibody, anti-Histone antibody, anti-Nuc antibody, anti-Sm antibody, anti-Ro60 antibody, anti-Ro52 antibody, anti-SSB antibody, anti-Cenp-B antibody, anti-Scl-70 antibody, and anti-AMA-M2 antibody (Kappa > 0.7, P < 0.05), but showed a moderate agreement for the detection of anti-Rib-P antibody and anti-Jo-1 antibody (Kappa = 0.671 and 0.665; P < 0.05). In addition, the diagnostic performance of these antibodies detected by both methods was similar for SLE. The diagnostic model's area under the curve values, sensitivity, and specificity, including an anti-dsDNA antibody and an anti-Ro60 antibody detected by CLIA, were 0.997, 0.962, and 0.978, respectively. These values were higher than the diagnostic performance of individual antibodies. CONCLUSION: CLIA and LIA demonstrated excellent overall consistency in detecting ANA profiles. A diagnostic model based on CLIA-detected antibodies can successfully contribute to developing a novel technique for detecting SLE.

7.
Cell Res ; 31(10): 1072-1087, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34239070

RESUMO

Glioblastoma (GBM) is a prevalent and highly lethal form of glioma, with rapid tumor progression and frequent recurrence. Excessive outgrowth of pericytes in GBM governs the ecology of the perivascular niche, but their function in mediating chemoresistance has not been fully explored. Herein, we uncovered that pericytes potentiate DNA damage repair (DDR) in GBM cells residing in the perivascular niche, which induces temozolomide (TMZ) chemoresistance. We found that increased pericyte proportion correlates with accelerated tumor recurrence and worse prognosis. Genetic depletion of pericytes in GBM xenografts enhances TMZ-induced cytotoxicity and prolongs survival of tumor-bearing mice. Mechanistically, C-C motif chemokine ligand 5 (CCL5) secreted by pericytes activates C-C motif chemokine receptor 5 (CCR5) on GBM cells to enable DNA-dependent protein kinase catalytic subunit (DNA-PKcs)-mediated DDR upon TMZ treatment. Disrupting CCL5-CCR5 paracrine signaling through the brain-penetrable CCR5 antagonist maraviroc (MVC) potently inhibits pericyte-promoted DDR and effectively improves the chemotherapeutic efficacy of TMZ. GBM patient-derived xenografts with high CCL5 expression benefit from combined treatment with TMZ and MVC. Our study reveals the role of pericytes as an extrinsic stimulator potentiating DDR signaling in GBM cells and suggests that targeting CCL5-CCR5 signaling could be an effective therapeutic strategy to improve chemotherapeutic efficacy against GBM.


Assuntos
Glioblastoma , Animais , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Glioblastoma/tratamento farmacológico , Camundongos , Comunicação Parácrina , Pericitos , Temozolomida/farmacologia , Temozolomida/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto
8.
World J Stem Cells ; 12(6): 500-513, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32742567

RESUMO

BACKGROUND: With continuous advancement of industrial society, environmental pollution has become more and more serious. There has been an increase in infertility caused by environmental factors. Nonylphenol (NP) is a stable degradation product widely used in daily life and production and has been proven to affect male fertility. However, the underlying mechanisms therein are unclear. Thus, it is necessary to study the effect and mechanism of NP on spermatogonial stem cells (SSCs). AIM: To investigate the cytotoxic effect of NP on SSCs via the phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway. METHODS: SSCs were treated with NP at 0, 10, 20 or 30 µmol. MTT assay was performed to evaluate the effect of NP on the proliferation of SSCs. Flow cytometry was conducted to measure SSC apoptosis. The expression of Bad, Bcl-2, cytochrome-c, pro-Caspase 9, SOX-2, OCT-4, Nanog, Nanos3, Stra8, Scp3, GFRα1, CD90, VASA, Nanos2, KIT, PLZF and PI3K/AKT/mTOR-related proteins was observed by western blot, and the mRNA expression of SOX-2, OCT-4 and Nanog was detected by quantitative reverse transcription polymerase chain reaction. RESULTS: Compared with untreated cells (0 µmol NP), SSCs treated with NP at all concentrations showed a decrease in cell proliferation and expression of Bcl-2, Nanog, OCT-4, SOX-2, Nanos3, Stra8, Scp3, GFRα1, CD90, VASA, Nanos2, KIT, and PLZF (P < 0.05), whereas the expression of Bad, cytochrome-c, and pro-Caspase 9 increased significantly (P < 0.05). We further examined the PI3K/AKT/mTOR pathway and found that the phosphorylation of PI3K, AKT, mTORC1, and S6K was significantly decreased by NP at all concentrations compared to that in untreated SSCs (P < 0.05). NP exerted the greatest effect at 30 µmol among all NP concentrations. CONCLUSION: NP attenuated the proliferation, differentiation and stemness maintenance of SSCs while promoting apoptosis and oxidative stress. The associated mechanism may be related to the PI3K/AKT/mTOR pathway.

9.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 36(6): 804-7, 2005 Nov.
Artigo em Zh | MEDLINE | ID: mdl-16334558

RESUMO

OBJECTIVE: To investigate the effect of truncated PDGF-alpha receptor on proliferation expression of c-sis mRNA of pulmonary artery vascular smooth muscular cells(VSMC). METHODS: Tissue mass culture was done to get vascular smooth muscular cells of pulmonary artery. Different concentrations of truncated PDGF-alpha receptor and adenoviral recombined body (Ad5CMV-PalphaRtr, ACP) were added into the cultures. VSMC proliferation curves were obtained using MTT test. The expression of c-sis mRNA was detected by PCR. RESULTS: ACP at 5 ml/L and 10 ml/L concentrations restrained the proliferation of VSMC apparently with the peak of cell growth being attenuated or eliminated. The curve presented ascending tendency only after 7 days. Affected by 5 ml/L ACP, PDGF-BB exerted no significant accelerating effect on the proliferation of VSMC. The expression of c-sis mRNA was up-regulated under the effect of ACP. Affected by 5 ml/L ACP and PDGF-BB, the expression of c-sis mRNA was down-regulated. CONCLUSION: ACP at 5 ml/L and 10 ml/L concentration powerful inhibitor of cellular proliferation for pulmonary artery VSMC. It can increase c-sis mRNA expression significantly and the increase seems to be ACP dosage dependent.


Assuntos
Músculo Liso Vascular/metabolismo , Proteínas Proto-Oncogênicas c-sis/biossíntese , Artéria Pulmonar/citologia , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/fisiologia , Animais , Animais Recém-Nascidos , Proliferação de Células , Células Cultivadas , Feminino , Masculino , Músculo Liso Vascular/patologia , Proteínas Proto-Oncogênicas c-sis/genética , Artéria Pulmonar/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Suínos
10.
PLoS One ; 10(5): e0126176, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25946186

RESUMO

Recent studies found that TIPE2 was involved in cancer development. However, little is known about TIPE2 in lung cancer. Our study aims to clarify the role of TIPE2 in lung carcinogenesis. We examined the expression of TIPE2 in lung squamous cancer (LSC), small cell lung cancer and lung adenocarcinoma (AdC) tissues and found that TIPE2 expression was lost in small cell lung cancer, compared with adjacent non-tumor tissues. Overexpression of TIPE2 significantly inhibited the growth of lung cancer cell H446 in vitro and even suppressed tumor formation in vivo. Flow cytometry analysis found TIPE2 overexpression promoted apoptosis of H446. In TIPE2 over-expression cells, caspase-3, caspase-9, and Bax were significantly up-regulated while Bcl-2 was down-regulated. Moreover, coincident results were shown by immunohistochemistry in tumors from nude mice. TIPE2 inhibited the phosphorylation of Akt, while promoting the phosphorylation of P38, but had no effect on IκBα and ERK pathway. Taken together, TIPE2 promoted lung cancer cell apoptosis through affecting apoptosis-related molecules caspase-3, caspase-9, Bcl-2 and Bax, possibly via regulating P38 and Akt pathways, indicating that TIPE2 might be a novel marker for lung cancer diagnosis and therapy.


Assuntos
Apoptose/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Adenocarcinoma de Pulmão , Animais , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Caspase 3/metabolismo , Caspase 9/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Regulação para Baixo , Xenoenxertos , Humanos , Imuno-Histoquímica , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Carcinoma de Pequenas Células do Pulmão/metabolismo , Carcinoma de Pequenas Células do Pulmão/patologia , Proteínas Supressoras de Tumor/metabolismo , Proteína X Associada a bcl-2/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
11.
Zhonghua Xue Ye Xue Za Zhi ; 24(4): 181-4, 2003 Apr.
Artigo em Zh | MEDLINE | ID: mdl-12864947

RESUMO

OBJECTIVE: To explore the effect of T(3) on the expression of transferrin receptor (TfR) and ferritin (Fn) in K562 cells and its possible mechanism. METHODS: Flow cytometry was used for the detection of TfR expression, radioimmunoassay for Fn expression, RNA/protein band shift assay for the binding activity of iron regulatory protein (IRP) and iron responsive elements (IRE), and RT-PCR for TfR and Fn mRNA levels. RESULTS: Different concentration of T(3) significantly increased Fn expression of K562 cells, especially at 100 nmol/L and 200 nmol/L (p < 0.05). However, T(3) had no effect on TfR expression. T(3) decreased the binding activity between IRP and IRE, particularly at concentration of 50 nmol/L. Different concentration of T(3) increased Fn-H mRNA level at different time point while it had no effect on TfR mRNA level. CONCLUSION: T(3) increased Fn expression of K562 cells through the possible mechanisms of either the post-transcriptional regulation or transcriptional modulation.


Assuntos
Ferritinas/biossíntese , Receptores da Transferrina/biossíntese , Tri-Iodotironina/farmacologia , Ferritinas/efeitos dos fármacos , Ferritinas/genética , Citometria de Fluxo , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Humanos , Células K562 , RNA Mensageiro/genética , Radioimunoensaio , Receptores da Transferrina/efeitos dos fármacos , Receptores da Transferrina/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
12.
Zhonghua Er Ke Za Zhi ; 41(7): 528-30, 2003 Jul.
Artigo em Zh | MEDLINE | ID: mdl-14746681

RESUMO

OBJECTIVE: Functionally, erythropoietin (EPO) can promote the proliferation and growth of erythroid progenitor cells, and it is widely used in the treatment of anemia in chronic diseases caused by tumor and inflammation. However, it is unclear whether EPO has any effect on tumor cell iron metabolism and tumor cell proliferation. The purpose of this study was to explore the effects of recombinant human EPO (rhEPO) on the expression of transferrin receptor (TfR, CD(71) antigen) of leukemic cell K562 and its relation to cell cycle. METHODS: In vitro culture of K562 cell was performed with additions of various concentrations of rhEPO and Fe. Treatments were terminated at 24 h and 72 h, respectively. Then each group of cells was incubated with FITC-IgG antibody to CD(71) or PI, a kind of DNA dye. And TfR expression and DNA synthesis status were analyzed by flow-cytometry. RESULTS: (1) The expression of TfR by K562 cells increased significantly when incubated for 72 h with different concentrations of rhEPO. The measurement values of 5 U/ml, 10 U/ml and 20 U/ml groups were 12.2 +/- 1.40, 10.7 +/- 0.99 and 11.1 +/- 0.90, respectively. They were markedly increased when compared with that of control group (6.27 +/- 0.11, P < 0.05). (2) When incubated with rhEPO (5 u/ml) alone or combined with FeCl(3) (100 micro mol/L), the percentages of cells in S phase were 51.1% and 59.6%, respectively. They significantly increased when compared with that of control group (42.9%, P < 0.05). CONCLUSIONS: Iron is very important for the proliferation of both normal cells and leukemic cells. It is essential to the activity of ribonucleotide reductase (RR). The authors hypothesized that rhEPO would increase the expression of TfR and intracellular iron content of leukemic cells, which would enhance the DNA synthesis and cell proliferation. Therefore, the clinical application of rhEPO to promote erythropoiesis of cancer patients should be cautious.


Assuntos
Eritropoetina/farmacologia , Receptores da Transferrina/metabolismo , Ciclo Celular/efeitos dos fármacos , Citometria de Fluxo , Humanos , Células K562 , Proteínas Recombinantes
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