ABSTRACT
Objective: To explore the effects and molecular mechanism of the selective JAK1inhibitor SHR0302 and Ruxolitinib on myeloproliterative neoplasms (MPN) cell line SET2 and primary cells in vitro. Methods: Cell proliferation was detected by CCK8 kit. Colony forming experiment was conducted to evaluate erythroid burst colony formation unit (BFU-E) of primary cells from MPN patients. Multi-factor kits were used to detect six inflammatory cytokines. Phosphorylated proteins of Jak-Stat signaling pathway were tested by Western blot. Results: At different time points after treated with SHR0302 and Ruxolitinib, the inhibition of cell proliferation was dose dependent by both drugs (P<0.01) . The inhibitory rates of 2.5 μmol/L SHR0302 and 0.1 μmol/L Ruxolitinib on SET2 cells for 72 h were comparable, i.e. (59.94±0.60) % and (64.00±0.66) %, respectively, suggesting that the inhibitory effect of SHR0302 was weaker than that of Ruxolitinib. Similarly, both SHR0302 and Ruxolitinib inhibited BFU-E in primary marrow cells from MPN patients in a dose-dependent manner. SHR0302 1.0 μmol/L produced similar degree of inhibition compared to Ruxolitinib 0.2 μmol/L. Except IL-12, the expression of other 5 cytokines (IL-6, TNF-α, IL-1β, IL-2, IL-8) was significantly inhibited by 1.6 μmol/L SHR0302 in SET2 cells at 24 h (P<0.01) , while Ruxolitinib 1.0 μmol/L had the same effect. Several phosphorylated molecules of Jak-Stat signaling pathway were significantly inhibited by SHR0302 in SET2 cells only for 3 h. P-stat1 (Tyr701) , p-stat3 (Tyr705) were down-regulated when treated with SHR0302 1.0 μmol/L (P<0.05) , p-jak1 (tyr1022/1023) and p-stat5 (Tyr694) were inhibited at 5.0 μmol/L (P<0.05) . Ruxolitinib significantly inhibited the downstream STAT protein at 0.1 μmol/L. Again, the inhibitory effect of SHR0302 on protein expression was weaker than that of Ruxolitinib. Conclusion: SHR0302 can effectively inhibit the proliferation of MPN cell line and patients' primary cells, as well as the expression of inflammatory factors. The molecular mechanism is possibly related to the down-regulation of phosphorylated proteins of Jak-Stat signaling pathway. Overall, the anti-proliferative and anti-inflammatory effects of SHR0302 are weaker than those of Ruxolitinib.
Subject(s)
Humans , Anti-Inflammatory Agents , Cell Line , Cell Proliferation/drug effects , Histone-Lysine N-Methyltransferase , Janus Kinase 1 , Nitriles , Pyrazoles , Pyrimidines , Sulfuric AcidsABSTRACT
<p><b>OBJECTIVE</b>To summarize the clinical characteristics of peripheral blood, immune phenotypes, fusion genes and cytogenetics of patients with t(8;21) acute myeloid leukemia(AML) through the retrospective analysis of 586 patients with t(8;21) AML from 15 blood disease research centers in Northern area of China.</p><p><b>METHODS</b>The factors affecting prognosis of patients with t(8;21) AML were investigated by using univariate and multivariate COX regression.</p><p><b>RESULTS</b>The immune type of t(8;21) AML patients was mainly with HLA-DR, CD117, CD34, MPO, CD38, CD13and CD33(>95%), part of them with CD19and CD56; the most common accompanied mutation of t(8;21) AML patients was C-KIT mutation (37.8%); in addition to t(8;21) ectopic, the most common chromosomal abnormality was sex chromosome deletions (38.9%). The univariate analysis revealed a significant survival superiority of OS and PFS in t(8;21) AML patients of WBC≤3.5×10/L without C-KIT mutation, the newly diagnosed ones achieved HSCT(P<0.05), only survival superiority on OS in t(8;21) AML patients with extramedullary infiltration and CD19 positive; the results of multivariate analysis showed a significant survival superiority on OS and PFS in t(8;21) AML patients with WBC≤3.5×10/L(P<0.05).</p><p><b>CONCLUSION</b>The clinical features of t(8;21) AML patients in China are similar to those in other countries, WBC≤3.5×10/L is a good prognostic factor while the C-KIT mutation is a poor one in t(8;21) AML patients.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expressions of GRα, GRβ, GRγ, GRp and heat shock protein 90 (HSP90) in primary immune thrombocytopenia (ITP) patients and their correlations with glucocorticoid resistance.</p><p><b>METHODS</b>The expressions of glucocorticoid receptors (GRα, GRβ, GRγ, GRp) mRNA and HSP90 in peripheral blood mononuclear cells of 40 newly diagnosed ITP patients and 29 healthy volunteers were examined by real time PCR. Of them, 28 patients received glucocorticoid (GC) therapy divided into GC sensitive group (GCS) and GC resistant group (GCR) according to GC response. GRα, GRβ, GRγ, GRp, HSP90 mRNA and HSP90/GRα were analyzed in paired groups.</p><p><b>RESULTS</b>The expression of HSP90 mRNA was significantly decreased in ITP patients \[0.91(0.48 - 2.21)\] than in normal subjects \[1.41(0.83 - 2.61)\] (P < 0.05). There were no significant differences in mRNA expressions of GRα, GRβ, GRγ, GRp and HSP90/GRα between ITP patients and normal controls. The expression of GRα mRNA in GCS patients was significant higher than in GCR patients (P < 0.05). Moreover, no significant differences in mRNA expressions of GRβ, GRγ, GRp and HSP90 and the ratio of HSP90 to GRα were observed between GCS and GCR patients.</p><p><b>CONCLUSION</b>The expression of HSP90 mRNA decreased in adult ITP patients. GC resistance in adult ITP patients was associated with reduced expression of GRα. The very low expression of GRβ mRNA may be not involved in GC resistance in adult ITP.</p>
Subject(s)
Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Young Adult , Case-Control Studies , Glucocorticoids , Metabolism , HSP90 Heat-Shock Proteins , Genetics , Metabolism , RNA, Messenger , Genetics , Receptors, Glucocorticoid , Metabolism , Thrombocytopenia , MetabolismABSTRACT
<p><b>BACKGROUND</b>Chromosomal abnormalities have been shown to play an important prognostic role in multiple myeloma (MM). Interphase fluorescence in situ hybridization (i-FISH) has been much more effective to identify cytogenetic aberrations in MM than conventional cytogenetic technique (CC). To clearly determine the cytogenetic features of Chinese MM patients and identify their prognostic implications, we designed a multicenter study based on i-FISH including 672 patients from 52 hospitals in China.</p><p><b>METHODS</b>All 672 patients were systematically screened for the following genomic aberrations: del(13q), IgH rearrangement, del(p53) and 1q21 amplifications.</p><p><b>RESULTS</b>The analysis showed that the chromosomal changes were detected in 22.1% patients by CC and in 82.3% patients by i-FISH. The most common abnormalities by CC were chromosome 1 aberrations (48.4%), -13/13q- (37.6%), hyperdiploidy (36.6%), hypodiploidy (30.1%) and IgH rearrangements (23.7%). The most frequent abnormalities by FISH was del(13q), which was found in 60.4% patients, whereas IgH rearrangement, 1q21 amplification and p53 deletions were detected in 57.6%, 49.0% and 34.7% cases, respectively. By statistical analysis, -13/13q- by CC was associated with low level of platelet (P = 0.015), hyperdiploidy was associated with low level of serum albumin (P = 0.028), and IgH rearrangement by FISH was associated with high level of β2 microglobulin (P = 0.019). Moreover, 1q21 amplification and del(p53) by FISH conferred a high incidence of progressive disease (PD) after initial therapy. Metaphase detection of IgH rearrangements and chromosome 1 aberrations concurrently was associated with a short progression free survival (PFS) (P = 0.036). No significant prognostic implications of other cytogenetic abnormalities were found associated with overall survival and PFS.</p><p><b>CONCLUSIONS</b>Chinese MM patients had similar cytogenetic abnormalities compared with the previous reported studies. However, the prognostic significance of FISH aberrations were not clearly determined and further study is required.</p>
Subject(s)
Adult , Female , Humans , Male , Middle Aged , China , Chromosome Aberrations , Chromosomes, Human, Pair 1 , Genetics , Cytogenetic Analysis , In Situ Hybridization, Fluorescence , Karyotyping , Multiple Myeloma , Genetics , PathologyABSTRACT
To explore the conventional cytogenetic (CC) characteristics and the partial molecular cytogenetic characteristics of multiple myeloma (MM), R banding technique was used for karyotype analysis in 53 cases of MM, and fluorescence in situ hybridization(FISH) technique was used for molecular cytogenetic analysis in 20 cases out of them. The results showed that the rate of chromosome abnormality was 32.1% in 53 cases. Among these abnormalities, 82.4% were involved in 3 or more than 3 chromosome aberrations, the mode of chromosome was from 44 to 90. The chromosome karyotype abnormality was involved in all of 24 chromosomes, and 70.6% chromosome aberrations involved at least one of 1q21 amplification, 13q14 deletion, 17p13 deletion and 14q32 translocation. Some uncommon structural aberrations were observed, such as t(11;16)(p11;p13) and some chromosome abnormalities were often revealed in acute or chronic leukemia. FISH detection showed that the results of 3 in 12 cases of MM with normal karyotype were positive; the results of 5 in 8 cases of MM with abnormal karyotype were positive. It is concluded that the abnormal chromosome karyotype was relatively complex in most cases of MM showing obvious heterogenicity. Detected rate of chromosome abnormalities in MM can be raised by FISH, though FISH technique has its limitations. If CC analysis and FISH technique are combined, it will be useful to raise the identification capability in detection of abnormal chromosomes in the cytogenetic study of MM.
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Chromosome Aberrations , Cytogenetic Analysis , Methods , In Situ Hybridization, Fluorescence , Multiple Myeloma , GeneticsABSTRACT
This study was purposed to investigate the immunophenotype characteristics in multiple myeloma (MM) cells and their significance. The expressions of CD138, CD38, CD56, CD117, HLA-DR, CD3, CD7, CD13, CD33, CD19, CD20, CD22, CD34 in myeloma cells from 31 MM patients were detected by using CD45/SSC immunofluorescent flow cytometry and were confirmed with morphologic observation of myeloma cells. The results indicated that the proportion of myeloma cells detected by morphologic examination was 10%-68%, the proportion of myeloma cells detected by CD45/SSC gating was 9.72%-67.77%. The antigen positive expression rate in myeloma cells was as follows: CD138 61.29%, CD38 100%, CD56 46.15%, CD13 70.00%, CD33 29.03%, HLA-DR 74.19%, CD117 33.33%; the other antigen expressions were negative. It is concluded that the use of CD45/SSC gating technique can identify multiple myeloma cells. The proportion of myeloma cells gated was close to the result of morphological examination. The myeloma cells mainly express the antigens CD138, CD88, CD56, while the expressions of CD117, CD13, CD33 were seen in some MM patients. Myeloma cells don't express antigens of B- and T-lymphocytes, which suggest the heterogenicity of multiple antigens expressed by myeloma cells. However, the biological significance of antigen expression in myeloma cells is worthy to be further investigated.
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Antigens, CD , Allergy and Immunology , Flow Cytometry , Immunophenotyping , Multiple Myeloma , Allergy and ImmunologyABSTRACT
<p><b>OBJECTIVE</b>To explore the value of fluorescence in situ hybridization (FISH) technique in diagnosis of variant Ph chromosome translocation (VT) and Ph chromosome-negative chronic myelocytic leukemia (CML).</p><p><b>METHODS</b>Nine CML patients with VT and 2 Ph chromosome-negative CML patients confirmed by R banding were assayed with dual color-dual fusion BCR/ABL probe by FISH.</p><p><b>RESULTS</b>The 9 patients with VT involved chromosomes 1, 3, 5, 12, 13, 15, 17 and 21 besides chromosomes 9 and 22, and some of them showed recurrent aberrations; FISH results were positive and the signal feature was 2R2G1Y. The 2 Ph-negative CML patients had normal karyotypes; FISH was positive and the signal feature was 1R1G2Y and 1R1G1Y respectively.</p><p><b>CONCLUSION</b>FISH can provide better diagnosis for CML with VT and Ph-negative CML. Abnormal karyotype and marker gene changes can be assessed based on the signal feature of the positive cell. So FISH is a complementary method to banding technique in diagnosis of CML.</p>
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Chromosomes , Genetics , Fusion Proteins, bcr-abl , Genetics , In Situ Hybridization, Fluorescence , Methods , Leukemia, Myelogenous, Chronic, BCR-ABL Positive , Diagnosis , Genetics , Leukemia, Myeloid, Chronic, Atypical, BCR-ABL Negative , Diagnosis , Genetics , Philadelphia Chromosome , Translocation, GeneticABSTRACT
<p><b>OBJECTIVES</b>To identify the nonmuscle myosin heavy chain 9 (MYH9) gene mutation site in a May-Hegglin anomaly(MHA) patient, and to analyze the genotype of her relatives to exclude the inherit correlation between the proband and her family members.</p><p><b>METHODS</b>Inclusion bodies in neutrophils of the proband were examined by transmission electron microscope, and giant platelets by scanning electron microscope. The mutation "hot spot" on the MYH9 gene of the proband and her family members was amplified with polymerase chain reaction(PCR), and then sequenced in both directions to identify the mutant site.</p><p><b>RESULTS</b>(1) The proband manifested with the typical MHA triad of giant platelet, thrombocytopenia and Dohle-like inclusion bodies in neutrophil. However, all of the proband's family members had no such anomaly. (2) Transmission electron microscope and scanning electron microscope confirmed that giant platelets and neutrophils inclusion bodies existed in the proband peripheral blood cells. (3) There was a missense mutation 5797 C-->T in the exon 40 of MYH9 gene which led to Arg changing into termination codon (Arg1933 stop). The proband also had a heterozygous mutation 4876A-->G in exon 33. There was no abnormal finding in the sites mentioned above in her mother, while her father carried the homozygous 4876A-->G mutation.</p><p><b>CONCLUSIONS</b>This MHA case is a sporadic one, in whose family a mode for autosomal dominant inheritance can not be established. The 5797C-->T substitution in MYH9 gene is a pathogenic mutation, however, 4876A-->G is simply a polymorphism.</p>
Subject(s)
Adult , Female , Humans , Hearing Loss, Sensorineural , Molecular Motor Proteins , Genetics , Mutation , Myosin Heavy Chains , Genetics , Polymorphism, Genetic , Thrombocytopenia , Blood , GeneticsABSTRACT
This study was aimed to investigate the effect of plasmid-mediated RNAi targeting hTERT on blocking hTERT gene and inhibiting telomerase activity in leukemia cell line K562. For inhibiting hTERT mRNA, three siRNA strands were chemosynthesized and transfected into K562 cells, two effective and specific siRNA strands were chosen. Then plasmid pSUPER-U6-Kan rhTERT-1, pSUPER-U6-Kan rhTERT-2 targeting hTERT mRNA were constructed and transfected into K562 cells by liposome. The expression of hTERT mRNA, telomerase activity and cell apoptosis were detected at 48 hours and 72 hours. The results showed that three chemosynthesized strands began to significantly inhibit target gene expression at 48 hours, but the inhibiting rates were different. The inhibiting effect disappeared after 72 hours. After plasmid pSUPER-U6-Kan rhTERT -1 (P-1 group) and pSUPER-U6-Kan rhTERT -2 (P-2 group) were transfected into K562 cells, the expressions of hTERT mRNA both decreased in the two groups. The expression of hTERT mRNA in P-1 group was 0.39+/-0.13 at 48 hours, 0.57+/-0.32 at 72 hours. The expression of hTERT mRNA in P-2 group was 0.55+/-0.20 at 48 hours, 0.88+/-0.23 at 72 hours. Telomerase activity in P-1 group was 0.42+/-0.07 at 48 hours, 0.31+/-0.08 at 72 hours; the telomerase activity in group P-2 was 0.49+/-0.27 at 48 hours, 0.39+/-0.03 at 72 hours while telomerase activities in both groups were significantly lower than that in negative control group (0.88+/-0.30, 0.88+/-0.32). At 48 hours, the apoptosis rates in P-1 group (18.39+/-3.08%) and P-2 group (15.5+/-3.59%) were significantly higher than that in negative control group (7.64+/-3.73%). At 72 hours the apoptosis rate in P-1 group (13.2+/-1.18%) and in P-2 group (12.86+/-3.09%) had no significant difference as compared with negative control group (8.07+/-0.19%). It is concluded that RNAi targeting hTERT inhibits the expression of hTERT mRNA, and therefore inhibits telomerase activity. The inhibiting effect is closely correlated with target site. The si-hTERT-1 effect is better than si-hTERT-2, while si-hTERT-3 almost has no effect at all. The effective time of plasmid-induced RNAi is obviously longer than that of chemosynthesized siRNA. The former is longer than 72 hours, while the latter is only 48 hours. After the telomerase activity is inhibited, cell apoptosis increases a little than control group at 48 hours. At 72 hours cell apoptosis has no difference with control group. It is supposed that some cells can be induced to differentiation when telomerase activity has been down regulated.
Subject(s)
Humans , Apoptosis , Genetics , Down-Regulation , K562 Cells , Plasmids , Genetics , RNA Interference , RNA, Messenger , Genetics , Metabolism , RNA, Small Interfering , Genetics , Telomerase , Genetics , Metabolism , TransfectionABSTRACT
The study was supposed to investigate the inhibitory effect of antisense phosphorothioate oligodeoxynucleotide (ASPSODN) targeting hTERT mRNA on gene of interest in K562 cells and influence of ASPSODN on telomerase activity and apoptosis of K562 cells. Human leukemia cell line K562 was transfected by liposome with ASPSODN and SPSODN (sense phosphorothioate oligodeoxynucleotide) at different concentrations (0.2, 0.6, 1.0 micromol/L). At the same time, blank control, liposome control and SPSODN groups were designed for comparison. The transfected cells were collected and detected at 24 and 48 hours; the expression of target gene hTERT mRNA and telomerase activity were detected by RT-PCR and TRAP-ELISA respectively, and cell apoptosis was assayed by flow cytometry. The results showed that after K562 cells were transfected for 24 hours, the expression of hTERT mRNA had no difference between liposome control (0.80+/-0.24), 0.2 micromol/L ASPSODN (0.69+/-0.12), 0.2 micromol/L SPSODN (0.72+/-0.25) and blank control (0.85+/-0.28), but the expression of hTERT mRNA in 0.6 micromol/L ASPSODN group (0.42+/-0.16) remarkably decreased as compared with liposome control group, 0.6 micromol/L SPSODN (0.69 +/- 0.26) had no obvious effect on the expression of hTERT mRNA, the expression of hTERT mRNA in 1.0 micromol/L ASPSODN and SPSODN groups both decreased; mortality of K562 cells transfected by liposome with 1.0 micromol/L ASPSODN and SPSODN remarkably increased. After 24 hours, telomerase relative activity of K562 cells showed no significant difference between blank control (88.9%) and liposome control (77.7%). The telomerase relative activities of K562 cells treated with 0.2, 0.6, 1.0 micromol/L ASPSODN were 60.6%, 52%, 58.2% respectively. There was significant difference as compared with blank control; 0.6 micromol/L ASPSODN showed significant difference (p=0.037), as compared with liposome control group. The telomerase relative activities in K562 cells treated with 0.2, 0.6, 1.0 micromol/L SPSODN were 76.1%, 72.2%, 65.7% respectively, but the telomerase relative activities of K562 cells in 0.2, 0.6 micromol/L SPSODN groups was not inhibited obviously. When K562 cells were treated for 48 hours, telomerase relative activity of K562 cells in each ASPSODN groups restored. It showed that telomerase relative activities of K562 cells treated with 0.2, 0.6, 1.0 micromol/L ASPSODN were 84.1%, 82.3%, 79.6% respectively, while telomerase relative activities of K562 cells treated with 0.2, 0.6, 1.0 micromol/L SPSODN for 48 hours were 74.8%, 74.5%, 67.9% respectively. Telomerase activity of K562 cells could not be inhibited by 0.2 and 0.6 micromol/L SPSODN. After culturing for 48 hours, the cell apoptosis rates of K562 in 0.6 micromol/L ASPSODN, 0.6 micromol/L SPSODN, liposome control and blank control groups were (4.82+/-0.39)%, (1.83+/-0.34)%, 1.84+/-1.04)%, (1.07+/-0.74)% respectively. There was difference between ASPSODN and SPSODN groups (p<0.05), but the significant difference was found in ASPSODN group as compared with liposome control and blank control (p<0.01). It is concluded that the ASPSODN targeting hTERT can specifically inhibit the expression of hTERT mRNA in K562 cells and significantly suppress the telomerase activity of K562 cells at 0.6 micromol/L, which inhibitory time is short. The ASPSODN at high concentration (1.0 micromol/L) shows definite cytotoxicity. 0.6 micromol/L of ASPSODN significantly induces cell apoptosis, while no such effect was seen in SPSODN group.
Subject(s)
Humans , Apoptosis , K562 Cells , Oligonucleotides, Antisense , Pharmacology , Telomerase , Genetics , MetabolismABSTRACT
To evaluate the significance of immunologic classification for typing of acute leukemia (AL). 68 cases of AL were classified by morphologic and immunologic typings. The results showed that the consistency rate was 94.1% between morphology and immunology, and 4 morphologic misdiagnosed cases were corrected by immunology; CD13 and CD33 were special myeloid lineage-associated antigens; AML-M(3) was often CD34 low-expressed and HLA-DR-negative; CD14 was often expressed in AML-M(4) and M(5); lymphoid lineage-associated antigens (CD7) were easily found in ANLL, and myeloid lineage-associated antigens were also found in ALL. In conclusion, immunologic classification can improve the accuracy in acute leukemia diagnosis. The diagnosis of some special AL, such as acute unidentified leukemia (AUL), AML-M(0) and so on, must rely on immunologic classification.
Subject(s)
Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Antigens, CD , Antigens, CD34 , Antigens, CD7 , Antigens, Differentiation, Myelomonocytic , CD13 Antigens , Immunophenotyping , Leukemia, Myeloid, Acute , Classification , Allergy and Immunology , Lipopolysaccharide Receptors , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Classification , Allergy and Immunology , Sialic Acid Binding Ig-like Lectin 3ABSTRACT
This study was aimed to investigate the modulating effects on telomere length and telomerase activity in K562 cells treated by arsenic trioxide, ginseng saponin, beta-elemene alone or in combination with cyclophosphamide (CTX) and to explore the possible mechanism and new therapy for acute leukemia. Human erythroleukemic cell line K562 was co-cultured with the above-mentioned drugs. Cells were collected after 24, 48 and 72 hours for further detection. Telomere length and telomerase activity were detected by Southern-blot and PCR-ELISA respectively. The effects of these drugs were observed at different concentrations and exposure time. The results showed that (1) ginseng saponin, arsenic trioxide, beta-elemene, or CTX could completely inhibit the telomerase activity of K562 cells at proper concentrations and exposure time. The inhibiting effects were enhanced when the three former drugs were used with CTX. Telomerase activity decreased proportionally with the concentrations and length of time. (2) viability of K562 cells was decreased after being co-cultured with arsenic trioxide, ginseng saponin, beta-elemene and CTX. The level of inhibition depends on the concentration and exposure time. (3) telomere length of K562 cells was 5.36 +/- 0.18 kb. After being co-cultured with those drugs for 72 hours, telomere length was 5.90 kb -6.50 kb, significantly longer than that of control (5.18 - 5.35 kb). It is concluded that arsenic trioxide, ginseng saponin, and beta-elemene can inhibit the growth and telomerase activity of K562 cells. The inhibiting effects were enhanced when they were used in combination with CTX. The depression of telomerase activity may be one of the mechanisms of anti-tumor effect. Less dosage and shorter course can be expected when arsenic trioxide, ginseng saponin, and beta-elemene are used in combination with CTX. When telomerase activity was depressed, the telomere length prolonged a little, indicating K562 cell line may extend telomeres by some alternative way other than telomerase activation.
Subject(s)
Humans , Arsenicals , Pharmacology , Cyclophosphamide , Pharmacology , Drug Synergism , K562 Cells , Oxides , Pharmacology , Panax , Chemistry , Saponins , Pharmacology , Sesquiterpenes , Pharmacology , Telomerase , Metabolism , TelomereABSTRACT
The aim was to explore the modulating and inhibiting effects of arsenic trioxide, ginseng saponin and beta-elemene on telomere length and telomerase activity in K562 cell line, and to study their anti-tumor mechanism and seek new method of therapy for acute leukemia. Human erythroleukemia cell line K562 was co-cultured with arsenic trioxide, ginseng saponin, beta-elemene separately, cells were collected after 24, 48 and 72 hours for further detecting. Telomere length and telomerase activity were detected by the methods of Southern-blot and PCR-ELISA respectively. The effects of these drugs on telomere length and telomerase activity were observed at different concentrations and length of time. The results showed that (1) telomerase activity of K562 cells decreased after co-cultured with arsenic trioxide, ginseng saponin and beta-elemene. The inhibiting effects depended on drug concentrations and length of time. When co-cultured at proper concentration and period of time, telomerase activity could be inhibited; (2) viability of K562 cells decreased after co-cultured with arsenic trioxide, ginseng saponin and beta-elemene, the inhibiting effect depends on drug concentrations and length of time; (3) after co-cultured with arsenic trioxide, ginseng saponin, and beta-elemene for 72 hours, telomere length of K562 cell line prolonged a little. It is concluded that (1) arsenic trioxide, ginseng saponin and beta-elemene can inhibit telomerase activity in K562 cell line, the suppression of telomerase activity may be one of the mechanisms of anti-tumor effect; (2) arsenic trioxide, ginseng saponin and beta-elemene can inhibit the growth of K562 cell line, the inhibiting effect depends on concentration and time; (3) when telomerase activity was suppressed, the telomere length prolonged a little, indicating that in K562 cell line may exist another mechanism to regulate telomere length, except telomerase activation.
Subject(s)
Humans , Arsenicals , Pharmacology , Cell Survival , K562 Cells , Oxides , Pharmacology , Panax , Saponins , Pharmacology , Sesquiterpenes , Pharmacology , Telomerase , Metabolism , TelomereABSTRACT
To explore the change of telomerase activity in acute leukemia (AL) cells and its relationship with cell cycle, PCR-ELISA was used to detect telomerase activity of bone marrow cells from 148 AL patients, including 92 cases with acute non-lymphocytic leukemia (ANLL) and 56 cases with acute lymphocytic leukemia (ALL). Thirty-six patients without bone marrow disorders were detected as normal control. The cell cycle of 16 patients and 4 controls was detected with flow cytometry. The results showed that the positive rate of telomerase was 71.6% (106/148) in the cells from AL patients, which was higher than that in the control group 5.6% (2/36). It was 88.9% (32/36) in the relapse group and 81.3% (61/75) in the untreated group. Both rates were higher than that in the CR group (35.1%, 13/37). There was no significant difference in the ALL and ANLL groups. The cell number in various phases of cell cycle had no significant difference between telomerase positive and negative groups. It was concluded that the activation of telomerase was very common in acute leukemia cells. Telomerase positive rate was closely associated with the different stages and progress of acute leukemia, and it might be a molecular marker for increased proliferation of leukemic cells during the process of the disease. Activation of telomeras had no correlation with cell number in different phases of cell cycle, while telomerase activity is modulated by other biological factors in addition to cell cycle.