OBJECTIVE: To investigate the expression level and clinical significance of Wilms' tumor 1 (WT1) in bone marrow of patients with myelodysplastic syndromes (MDS). METHODS: The clinical data of 147 MDS patients who accepted real-time quantitative polymerase chain reaction (RT-PCR) to detect the expression level of WT1 in bone marrow before treated in Nanfang Hospital, Southern Medical University from January 2017 to April 2021 were retrospectively analyzed. According to the expression level of WT1, the patients were divided into WT1⁺ group and WT1^- group, their clinical characteristics and prognosis were analyzed. RESULTS: The positive rate of WT1 in 147 MDS patients was 82.3%. There were significant differences in bone marrow blast count, aberrant karyotypes, WHO 2016 classification, and IPSS-R stratification between WT1⁺ group and WT1^- group (all P<0.05). Furthermore, the higher the malignant degree of MDS subtype and the risk stratification of IPSS-R, the higher expression level of WT1. Compared with WT1^- group, there were no differences in overall survival (OS) time and the time of transformation to AML in WT1⁺ group (both P>0.05). In patients who did not accept transplantation, the median OS time of WT1⁺ patients was significantly shorter than that of WT1^- patients (P=0.049). Besides, regarding WT1⁺ group, patients who underwent transplantation had longer OS time and lower mortality than those who received hypomethylating agents (P=0.002, P=0.005). CONCLUSION WT1 expression level directly reflects the disease progression, and it is also associated with prognosis of MDS patients.
Bone Marrow/metabolism* ; Humans ; Myelodysplastic Syndromes/diagnosis* ; Prognosis ; Retrospective Studies ; WT1 Proteins/metabolism*

Cell Proliferation ; drug effects ; DNA Methylation ; drug effects ; Humans ; K562 Cells ; Stilbenes ; pharmacology ; WT1 Proteins ; metabolism

The Wilms' tumor gene (WT1) is a transcription factor involved in tumorigenesis, especially in leukemogenesis. However, the role of WT1 expression in nonmalignant hematopoietic cells remains unclear. Furthermore, due to alternative splicing at two sites: 17 amino acid residues of exon 5 (+17AA) and 3 amino acid residues (+KTS) between exons 9 and 10, WT1 gene has four main isoforms (17AA+/KTS+, 17AA+/KTS-, 17AA-/KTS+, 17AA-/KTS-, abbreviation: +/+, +/-, -/+, -/-). The isoforms probably existed in hematopoietic cells, which make the research more complex. The aim of study was to elucidate the expression and its isoforms of WT1 gene in different cell subsets of healthy bone marrow donors. The fluorescence RT-PCR detection system was established to measure the expressions of full-length WT1, WT1 (+17AA) and WT1 (+KTS) in CD34(+)CD38(-) (stem cell), CD34(+)CD38(+) (progenitor cell), CD15(+)CD11b(+) (granulocyte), CD33(+)CD14(+) (monocyte), CD20(+)CD5(-) (B-lymphocyte) and CD20(-)CD5(+) (T-lymphocyte) subsets from 18 normal human bone marrow samples. The results showed that WT1 expressed in CD34(+)CD38(-), CD34(+)CD38(+), CD15(+)CD11b(+) and CD33(+)CD14(+), but not in CD20(+)CD5(-) and CD20(-)CD5(+) subsets. The highest expression was in CD34(+)CD38(-), but decreased gradually in CD15(+)CD11b(+) and CD33(+)CD14(+) subsets. WT1 (+17AA), WT1 (+KTS) and WT1 (+/+) isoforms were predominant in CD34(+)CD38(-) and CD34(+)CD38(+) primitive subsets, while in CD15(+)CD11b(+) and CD33(+)CD14(+) the dominant isoforms were WT1 (-17AA), WT1 (-KTS) and WT1 (-/-). It is concluded that the expression of WT1 in normal bone marrow decreases gradually with cell differentiation. Hematopoietic cells may adjust the ratios of WT1 isoforms to inhibit or promote cell differentiation.
Antigens, CD34 ; analysis ; Bone Marrow Cells ; metabolism ; Cell Differentiation ; Gene Expression Regulation ; Humans ; Protein Isoforms ; metabolism ; WT1 Proteins ; metabolism

OBJECTIVETo investigate the expression of the Wilms' tumor 1 (WT1) mRNA in childhood myelodysplastic syndrome (MDS), and to evaluate WT1 as a tool to differentiate MDS from aplastic anemia(AA).

METHODSThe quantitative expression of WT1 transcript by using real-time quantitative polymerase chain reaction (RQ-PCR) was performed in the bone marrow samples of 36 childhood MDS and 49 childhood AA, the samples were collected from September 2008 to December 2011.

RESULTS(1) The positive rate of WT1 in severe AA (SAA) was 0, 14.3% in chronic AA (CAA), 58.6% in refractory cytopenia (RC), 100% in refractory anemia with excessive blast (RAEB) and 97.5% in acute myeloid leukemia (AML). The mean level of WT1 in SAA, CAA, RC, RAEB and AML was 0.041%, 0.357%, 7.037%, 12.680% and 24.210%, respectively. The positive rate of WT1 in RC patients was higher than that of SAA (P = 0.000) and CAA (P = 0.001). (2) The positive rate of WT1 in patients with hypoplastic MDS was 66.7% and was higher than that of SAA (P = 0.000) and CAA (P = 0.001). The mean level of WT1 in patients with hypoplastic MDS was (3.022 ± 5.040)% and higher than that of SAA \[(0.041 ± 0.047)%, P = 0.000\] and CAA\[(0.351 ± 0.479)%, P = 0.002\].

CONCLUSIONSThe level of WT1 in childhood MDS was higher than that of childhood AA. The degree of WT1 expression in MDS increased during disease progression. WT1 is a useful tool for differentiating the childhood hypoplastic MDS from AA.

Adolescent ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Myelodysplastic Syndromes ; genetics ; metabolism ; pathology ; WT1 Proteins ; genetics ; metabolism

Humans ; Infant ; Kidney Neoplasms ; metabolism ; pathology ; surgery ; Male ; Mucin-1 ; metabolism ; Nephrectomy ; Precancerous Conditions ; metabolism ; pathology ; surgery ; Vimentin ; metabolism ; WT1 Proteins ; metabolism ; Wilms Tumor ; metabolism ; pathology ; surgery

OBJECTIVETo investigate the expression of WT1 gene in myelodysplastic syndrome (MDS) and to explore its clinical implications.

METHODSExpression of WT1 mRNA was detected in 53 patients with myelodysplastic syndrome and 10 healthy subjects by reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTWT1 gene was expressed in all MDS patients. The positive rate and expression level in MDS patients were higher than those in healthy subjects. The positive rates of WT1 expression in MDS-RAEB and MDS-RAEB-t groups were higher than those in MDS-RA and MDS-RAS groups. The expression level was gradually increased from MDS-RA and MDS-RAS groups to MDS-RAEB and MDS-RAEB-t groups.

CONCLUSIONThe expression of WT1 gene might be associated with the development of MDS, and it can be used for risk assessment and monitor of disease progression and therapeutic effects in MDS patients.

Adolescent ; Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Myelodysplastic Syndromes ; genetics ; metabolism ; Prognosis ; RNA, Messenger ; biosynthesis ; WT1 Proteins ; biosynthesis ; genetics

To study the cellular changes and the potential role of CD2-associated protein (CD2AP) in podocyte differentiation, conditionally immortalized murine podocyte cell line was cultured in RPMI 1640 medium under permissive condition at 33 °C. After transfection with CD2AP small interfering RNA (siRNA) the cells were shifted to non-permissive condition at 37 °C. Simultaneously, untransfected cells were taken as differentiation control. The podocyte proliferation rate was determined by MTT method. The expressions of CD2AP, WT1, synaptopodin and nephrin mRNAs were examined by RT-PCR. CD2AP, WT1 and nephrin protein expressions were examined by Western blot. The distribution of CD2AP, nephrin, F-actin and tubulin in differentiated and undifferentiated podocytes was detected by laser scanning confocal microscopy. The results showed: (1) CD2AP, WT1 and nephrin were stably expressed in differentiated and undifferentiated podocytes while synaptopodin was only expressed in differentiated podocytes. (2) CD2AP and nephrin mRNA and protein expressions were up-regulated during podocyte differentiation (P<0.05). (3) CD2AP and tubulin were distributed in the cytoplasm and perinulcear region in undifferentiated podocytes, and F-actin was predominantly localized to a cortical belt and paralleled to the cell axis. Under differentiation condition, CD2AP distribution profile was presented as peripheral accumulation, tubulin took on fascicular style and F-actin extended into foot processes in podocytes. CD2AP colocalized with nephrin and F-actin in undifferentiated podocytes. (4) After transfection with CD2AP siRNA, the expression of CD2AP was partially inhibited and cell growth was arrested; Synaptopodin, the differentiation podocyte marker, was apparently down-regulated; The differentiation of podocytes was delayed. The results demonstrate that podocyte differentiation is accompanied by cytoskeleton rearrangement and cell morphology change. CD2AP might play an essential role in podocyte differentiation.
Actins ; metabolism ; Adaptor Proteins, Signal Transducing ; physiology ; Animals ; Cell Differentiation ; Cell Line ; Cytoskeletal Proteins ; physiology ; Cytoskeleton ; metabolism ; Membrane Proteins ; metabolism ; Mice ; Microfilament Proteins ; metabolism ; Podocytes ; cytology ; RNA, Small Interfering ; Transfection ; WT1 Proteins ; metabolism

The molecular pathogenesis of leukemia is poorly understood. Earlier studies have shown both Wilms' tumor 1 suppressor gene (WT1) and CML28 abnormally expressed in malignant diseases of the hematopoietic system and WT1 played an important role in leukemogenesis. However, the relationship between molecular CML28 and WT1 has not been reported. Here we described the use of small interfering RNA (siRNA) against WT1 and CML28 in leukemic cell line K562 to examine the interaction between CML28 and WT1. WT1 and CML28 gene expression in transfected K562 cells was detected by using RQ-PCR and Western blotting. K562 cells transfected with WT1-siRNA could greatly decrease both mRNA and protein expression levels of WT1 and CML28. In contrast, CML28-siRNA did not exert effect on WT1. Further, subcellular co-localization assay showed that the two proteins could co-localize in the cytoplasm of K562 cells, but WT1/CML28 complexes were not detected by using immunoprecipitation. It was suggested that there exists the relationship between CML28 and WT1. CML28 may be a downstream target molecule of WT1 and regulated by WT1, which will provide important clues for further study on the role of CML28 and WT1 in leukemic cells.
Antigens, Neoplasm ; metabolism ; Cell Line, Tumor ; Exosome Multienzyme Ribonuclease Complex ; metabolism ; Humans ; K562 Cells ; Leukemia, Erythroblastic, Acute ; metabolism ; Neoplasm Proteins ; metabolism ; Protein Interaction Mapping ; RNA-Binding Proteins ; metabolism ; Subcellular Fractions ; metabolism ; WT1 Proteins ; metabolism

OBJECTIVETo establish a one-step real-time quantitative RT-PCR assay for detecting the expression of WT1 mRNA, which allows detection of the minimal residue disease and prognostic prediction in leukemic patients.

METHODSWT1 gene fragment was amplified from the RNAs extracted from K562 cells using one-step RT-PCR. The quantitative standard were constructed by pMD 18-T vector cloning, and a Taqman-MGB fluorescent probe and a pair of primers were used to establish the one-step real-time fluorescence quantitative RT-PCR assay for WT1 gene detection. The sensitivity, repeatability and stability of this assay were evaluated and verified.

RESULTSThe sensitivity of this assay reached the 10(-4) level. The standard template of 1.0 x 10(6)-1.0 x 10(2) copies/ml were amplified by the one-step real-time fluorescence quantitative RT-PCR assay , and the Ct value was strongly correlated (r=0.998) to the logarithm of the initial template concentration. The repetition Ct value and both the inter-tube and inter-batch coefficients of variation (CV%) were less than 8%.

CONCLUSIONThe one-step real-time fluorescence quantitative RT-PCR assay has good sensitivity, repeatability and specificity, and the one-step completion of the reverse transcription and PCR processes may reduce the operational complexities and the possibility of contamination.

Humans ; K562 Cells ; Leukemia ; metabolism ; RNA, Messenger ; analysis ; metabolism ; Reproducibility of Results ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Sensitivity and Specificity ; WT1 Proteins ; analysis ; metabolism

OBJECTIVETo explore the changes in expression of WT1 gene and ration of its isomers during phorbol ester (TPA) induced differentiation of leukemia cell line K562 by fluorescence quantitative RT-PCR and analysis the relationship between different isomers and hematogenic cell differentiation.

METHODSThe degree of cellular maturation were verified by NBT reduction test and immunophenotyping. Expression of WT1 gene was determined by fluorescence quantitative RT-PCR during differentiation of K562 cell line. The relative ratio of the four splicing variants WT1 ( + / + ), WT1 ( + / - ), WT1 ( - / + ), WT1 ( - / - ) were calculated.

RESULTSDuring the differentiation of K562 cell, the NBT reduction rate and the CD9 positive rate both increased significantly (P < 0. 05). The expression of WT1 gene decreased immediately to (1.67 +/- 0.45) x 10(-3) from (4.67 +/- 1.11) x 10(-3), and then increased again to (4.64 +/- 1.53) x 10(-3) at 96 hours. The ratio of WT1 ( + / + ) was decreased gradually, from 0 hour (39.65 +/- 19.46)% to 96 hour (15.25 +/- 7.27)%. While the ratio of WT1( - / - ) was increased, from 0 hour (15.38 +/- 11.34)%, to 96 hour (37.60 +/- 11.90)%. The other two isomers ratios did not change significantly.

CONCLUSIONDuring the TPA induced differentiation of K562 cell, there are two high expression levels of WT1 gene. Before differentiation, the majority is WT1 ( + / + ), and after differentiation, is WT1 ( - / - ). It indicates that WT1 gene may activate or inhibit cell differentiation by regulating the ratio of its four splicing variants.

Cell Differentiation ; drug effects ; genetics ; Gene Expression ; drug effects ; Humans ; K562 Cells ; Phorbol Esters ; pharmacology ; Protein Isoforms ; genetics ; metabolism ; WT1 Proteins ; genetics ; metabolism