摘要
Objective: To analyze the current adherence to imatinib in patients with gastrointestinal stromal tumors (GIST) in China and its influencing factors. Methods: A cross-sectional survey was conducted. Study period: from October 1, 2020 to November 31, 2020. Study subjects: GIST patients taking imatinib who were diagnosed and treated in public tertiary level A general hospitals or oncology hospitals; those who had not been pathologically diagnosed, those who never received imatinib, or those who had taken imatinib in the past but stopped afterwards were excluded. The Questionnaire Star online surgery platform was used to design a questionnaire about the adherence to adjuvant imatinib therapy of Chinese GIST patients. The link of questionnaire was sent through WeChat. The questionnaire contained basic information of patients, medication status and Morisky Medication Adherence Scale. Results: A total of 2162 questionnaires from 31 provinces, autonomous regions, and municipalities were collected, of which 2005 were valid questionnaires, with an effective rate of 92.7%. The survey subjects included 1104 males and 901 females, with a median age of 56 (22-91) years old. Working status: 609 cases (30.4%) in the work unit, 729 cases (36.4%) of retirement, 667 cases of flexible employment or unemployment (33.3%). Education level: 477 cases (23.8%) with bachelor degree or above, 658 cases (32.8%) of high school, 782 cases (39.0%) of elementary or junior high school, 88 cases (4.4%) without education. Marital status: 1789 cases (89.2%) were married, 179 cases (8.9%) divorced or widowed, 37 cases (1.8%) unmarried. Two hundred and ninety-four patients (14.7%) had metastasis when they were first diagnosed, including 203 liver metastases, 52 peritoneal metastases, and 39 other metastases. One thousand eight hundred and sixty-nine patients underwent surgical treatment, of whom 1642 (81.9%) achieved complete resection. The median time of taking imatinib was 25 (1-200) months. Common adverse reactions of imatinib included 1701 cases (84.8%) of periorbital edema, 1031 cases (51.4%) of leukopenia, 948 cases (47.3%) of fatigue, 781 cases (39.0%) of nausea and vomiting, 709 cases (35.4%) of rash, and 670 cases (33.4%) of lower extremity edema. The score of the Morisky Medication Adherence Scale showed that 392 cases (19.6%) had poor adherence, 1023 cases (51.0%) had moderate adherence, and 590 cases (29.4%) had good adherence. Univariate analysis showed that gender, age, work status, economic income, residence, education level, marriage, the duration of taking medication and adverse reactions were associated with adherence to adjuvant imatinib therapy (all P<0.05). Multivariate analysis showed that female (OR=1.264, P=0.009), non-retirement (OR=1.454, P=0.001), monthly income ≤4000 yuan (OR=1.280, P=0.036), township residents (OR=1.332, P=0.005), unmarried or divorced or widowed (OR=1.362, P=0.026), the duration of imatinib medication >36 months (OR=1.478, P<0.001) and adverse reactions (OR=1.719, P=0.048) were independent risk factors for poor adherence to adjuvant imatinib. Among patients undergoing complete resection, 324 (19.7%) had poor adherence, 836 (50.9%) had moderate adherence, and 482 (29.4%) had good adherence. Meanwhile, 55 patients with good adherence (11.4%) developed recurrence after surgery, 121 patients with moderate adherence (14.5%) developed recurrence, 61 patients with poor adherence (18.8%) developed recurrence, and the difference was statistically significant (P=0.017). Conclusions: The adherence to adjuvant therapy with imatinib in Chinese GIST patients is relatively poor. Females, non-retirement, monthly income ≤4000 yuan, township residents, unmarried or divorced or widowed, the duration of imatinib medication >36 months, and adverse reactions are independently associated with poor adherence of GIST patients. Those with poor adherence have a higher risk of recurrence after surgery. Positive interventions based on the above risk factors are advocated to improve the prognosis of patients with GIST.
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Antineoplastic Agents/therapeutic use , Chemotherapy, Adjuvant , Cross-Sectional Studies , Gastrointestinal Stromal Tumors/drug therapy , Imatinib Mesylate/therapeutic use , Neoplasm Recurrence, Local/drug therapy摘要
Gefitinib is used as a first-line treatment for advanced non-small cell lung cancer (NSCLC). Unfortunately, most NSCLC patients inevitably develop gefitinib resistance during treatment. In addition to EGFR mutation status, the mechanisms involved are largely unknown. In this study, we showed that miR-124, a tumor suppressor, was significantly down-regulated in gefitinib-resistant NSCLC patients and cell lines compared with gefitinib-sensitive patients and cell lines. In addition, the miR-124 depletion induced gefitinib resistance, and miR-124 overexpression sensitized gefitinib-resistant cells to gefitinib. Mechanistic analysis revealed that miR-124 decreased SNAI2 and STAT3 expression by directly targeting their 3'UTRs and that knocking down SNAI2 or STAT3 partly reversed the gefitinib resistance induced by miR-124 depletion. Our data demonstrate that the miR-124 plays a new critical role in acquired resistance to gefitinib and that the manipulation of miR-124 might provide a therapeutic strategy for reversing acquired gefitinib resistance.
Subject(s)
Humans , 3' Untranslated Regions , Antineoplastic Agents , Pharmacology , Therapeutic Uses , Carcinoma, Non-Small-Cell Lung , Drug Therapy , Genetics , Metabolism , Cell Line, Tumor , Drug Resistance, Neoplasm , Genetics , HEK293 Cells , Lung Neoplasms , Drug Therapy , Genetics , Metabolism , MicroRNAs , Genetics , Quinazolines , Pharmacology , Therapeutic Uses , STAT3 Transcription Factor , Genetics , Metabolism , Snail Family Transcription Factors , Genetics , Metabolism摘要
5-aminosalicylic acid (5-ASA) is drug of choice for the treatment of ulcerative colitis (UC). In this study, the efficacy of topical versus oral 5-ASA for the treatment of UC was examined as well as the action mechanism of this medication. A flexible tube was inserted into the rat cecum to establish a topical administration model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced UC. A total of 60 rats were divided into sham operation group (receiving an enema of 0.9% saline solution instead of the TNBS solution via the tube), model group, topical 5-ASA group, oral Etiasa group (a release agent of mesalazine used as positive control) and oral 5-ASA group (n=12 each). Different treatments were administered 1 day after UC induction. The normal saline (2 mL) was instilled twice a day through the tube in the sham operation group and model group. 5-ASA was given via the tube in the topical 5-ASA group (7.5 g/L, twice per day, 100 mg/kg), and rats in the oral Etiasa group and oral 5-ASA group intragastrically received Etiasa (7.5 g/L, twice per day, 100 mg/kg) and 5-ASA (7.5 g/L, twice per day, 100 mg/kg), respectively. The body weight was recorded every day. After 7 days of treatment, blood samples were drawn from the heart to harvest the sera. Colonic tissues were separated and prepared for pathological and related molecular biological examinations. The concentrations of 5-ASA were detected at different time points in the colonic tissues, feces and sera in different groups by using the high pressure liquid chromatography (HPLC). The results showed that the symptoms of acute UC, including bloody diarrhea and weight loss, were significantly improved in topical 5-ASA-treated rats. The colonic mucosal damage, both macroscopical and histological, was significantly relieved and the myeloperoxidase activity was markedly decreased in rats topically treated with 5-ASA compared with those treated with oral 5-ASA or Etiasa. The mRNA and protein expression of IL-1β, IL-6, and TNF-α was down-regulated in the colonic tissue of rats topically treated with 5-ASA, significantly lower than those from rats treated with oral 5-ASA or Etiasa. The concentrations of 5-ASA in the colonic tissue were significantly higher in the topical 5-ASA group than in the oral 5-ASA and oral Etiasa groups. It was concluded that the topical administration of 5-ASA can effectively increase the concentration of 5-ASA in the colonic tissue, decrease the expression of proinflammatory cytokines, alleviate the colonic pathological damage and improve the symptoms of TNBS-induced acute UC in rats.
Subject(s)
Animals , Male , Rats , Administration, Oral , Administration, Topical , Anti-Inflammatory Agents, Non-Steroidal , Pharmacology , Colitis, Ulcerative , Drug Therapy , Colon , Metabolism , Pathology , Down-Regulation , Drug Administration Schedule , Gene Expression , Immunohistochemistry , Interleukin-1beta , Genetics , Metabolism , Interleukin-6 , Genetics , Metabolism , Intestinal Mucosa , Metabolism , Pathology , Mesalamine , Pharmacology , Peroxidase , Metabolism , Rats, Wistar , Reverse Transcriptase Polymerase Chain Reaction , Time Factors , Treatment Outcome , Trinitrobenzenesulfonic Acid , Tumor Necrosis Factor-alpha , Genetics , Metabolism摘要
5-aminosalicylic acid (5-ASA) is drug of choice for the treatment of ulcerative colitis (UC). In this study, the efficacy of topical versus oral 5-ASA for the treatment of UC was examined as well as the action mechanism of this medication. A flexible tube was inserted into the rat cecum to establish a topical administration model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced UC. A total of 60 rats were divided into sham operation group (receiving an enema of 0.9% saline solution instead of the TNBS solution via the tube), model group, topical 5-ASA group, oral Etiasa group (a release agent of mesalazine used as positive control) and oral 5-ASA group (n=12 each). Different treatments were administered 1 day after UC induction. The normal saline (2 mL) was instilled twice a day through the tube in the sham operation group and model group. 5-ASA was given via the tube in the topical 5-ASA group (7.5 g/L, twice per day, 100 mg/kg), and rats in the oral Etiasa group and oral 5-ASA group intragastrically received Etiasa (7.5 g/L, twice per day, 100 mg/kg) and 5-ASA (7.5 g/L, twice per day, 100 mg/kg), respectively. The body weight was recorded every day. After 7 days of treatment, blood samples were drawn from the heart to harvest the sera. Colonic tissues were separated and prepared for pathological and related molecular biological examinations. The concentrations of 5-ASA were detected at different time points in the colonic tissues, feces and sera in different groups by using the high pressure liquid chromatography (HPLC). The results showed that the symptoms of acute UC, including bloody diarrhea and weight loss, were significantly improved in topical 5-ASA-treated rats. The colonic mucosal damage, both macroscopical and histological, was significantly relieved and the myeloperoxidase activity was markedly decreased in rats topically treated with 5-ASA compared with those treated with oral 5-ASA or Etiasa. The mRNA and protein expression of IL-1β, IL-6, and TNF-α was down-regulated in the colonic tissue of rats topically treated with 5-ASA, significantly lower than those from rats treated with oral 5-ASA or Etiasa. The concentrations of 5-ASA in the colonic tissue were significantly higher in the topical 5-ASA group than in the oral 5-ASA and oral Etiasa groups. It was concluded that the topical administration of 5-ASA can effectively increase the concentration of 5-ASA in the colonic tissue, decrease the expression of proinflammatory cytokines, alleviate the colonic pathological damage and improve the symptoms of TNBS-induced acute UC in rats.
摘要
This study aimed to examine the effect of the 24 N-terminal amino acids (N24) of p55PIK, a regulatory subunit of phosphatidylinositol 3-kinase (PI3K), on the endotoxin lipopolysaccharide (LPS)-stimulated release of the cytokines (CKs) by HaCaT cells. The fusion protein, trans-acting activator of transcription (TAT)-N24 (an experimental peptide, EP) containing the N24 of PI3K-p55PIK, was constructed, and TAT-N24 fusion peptide was expressed and identified in BL21 E·coli. HaCaT cells (a human keratinocyte cell line) was cultured and stimulated by LPS at 100 ng/mL for 1, 2, 4, 8, 16 or 24 h, or by LPS at 10, 100 ng/mL, 1, 10 or 100 μg/mL of for 4 h. Changes in the protein and mRNA levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-8 (IL-8) released by HaCaT cells following EP intervention were determined by enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (PCR). Immunofluorescence confocal laser scanning microscopy was utilized to detect the protein expression and translocation of the p65 subunit of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB p65) in HaCaT cells. The expression of the NF-κB inhibitor alpha (IκB-α) protein in LPS-stimulated HaCaT cells after the EP intervention was measured by Western blotting. The results showed that EP treatment increased TNF-α secretion from HaCaT cells. EP at certain concentrations could effectively inhibit the LPS-stimulated release of TNF-α, IL-6 and IL-8 from HaCaT cells. The ELISA assay demonstrated that the concentrations of TNF-α, IL-6 and IL-8 in the supernatants of LPS-stimulated cells were reduced from 208.06±30.18, 86.4±9.78 and 260.59±54.05 pg/mL to 121.78±22.26, 53.18±7.36 and 125.08±35.17 pg/mL, respectively, in the supernatants of cells treated by LPS and EP combined. Real-time PCR also revealed that the expression of the three pro-inflammatory CKs was significantly decreased after EP intervention. Immunofluorescence confocal laser scanning microscopy showed that NF-κB p65 protein was primarily expressed in the cytoplasm of non-stimulated HaCaT cells. After LPS stimulation, NF-κB p65 was translocated into the nucleus, and the nuclear expression of this protein increased. The nuclear NF-κB p65 protein expression was inhibited after the addition of EP. Western blotting showed that IκB-α expression began to decrease 30 min after LPS stimulation and declined to a trough 4 h later. IκB-α expression began to gradually recover 16 h after LPS stimulation but remained at a lower-than-normal level at 24 h. Greater IκB-α expression was found in cells treated with LPS and EP combined than those treated with LPS alone. It was concluded that EP can effectively inhibit the LPS-stimulated expression of TNF-α, IL-6, and IL-8, which involves the inhibition of the hydrolysis of IκB-α and thereby blockage of the nuclear translocation of NF-κB p65.
Subject(s)
Humans , Amino Acids , Metabolism , Cell Line , Cytokines , Metabolism , Endotoxins , Metabolism , Inflammation , Metabolism , Phosphatidylinositol 3-Kinases , Metabolism摘要
The forkhead family members of transcription factors (FoxOs) are expected to be potential cancer-related drug targets and thus are being extremely studied recently. In the present study, FoxO3a, one major member of this family, was identified to be down-regulated in colorectal cancer through micro-array analysis, which was confirmed by RT-PCR and Western blot in 28 patients. Moreover, immunohistochemistry (IHC) showed that the expression levels of FoxO3a were remarkably reduced in 99 cases of primary colorectal cancer, liver metastasis, and even in metaplastic colorectal tissue. IHC also revealed an exclusion of FoxO3a from the nucleus of most cells of tumor-associated tissues. Silencing FoxO3a by siRNA led to elevation of G2-M phase cells. We conclude that the downregulation of FoxO3a may greatly contribute to tumor development, and thus FoxO3a may represent a novel therapeutic target in colorectal cancer.
摘要
This study aimed to examine the effect of the 24 N-terminal amino acids (N24) of p55PIK, a regulatory subunit of phosphatidylinositol 3-kinase (PI3K), on the endotoxin lipopolysaccharide (LPS)-stimulated release of the cytokines (CKs) by HaCaT cells. The fusion protein, trans-acting activator of transcription (TAT)-N24 (an experimental peptide, EP) containing the N24 of PI3K-p55PIK, was constructed, and TAT-N24 fusion peptide was expressed and identified in BL21 E·coli. HaCaT cells (a human keratinocyte cell line) was cultured and stimulated by LPS at 100 ng/mL for 1, 2, 4, 8, 16 or 24 h, or by LPS at 10, 100 ng/mL, 1, 10 or 100 μg/mL of for 4 h. Changes in the protein and mRNA levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-8 (IL-8) released by HaCaT cells following EP intervention were determined by enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (PCR). Immunofluorescence confocal laser scanning microscopy was utilized to detect the protein expression and translocation of the p65 subunit of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB p65) in HaCaT cells. The expression of the NF-κB inhibitor alpha (IκB-α) protein in LPS-stimulated HaCaT cells after the EP intervention was measured by Western blotting. The results showed that EP treatment increased TNF-α secretion from HaCaT cells. EP at certain concentrations could effectively inhibit the LPS-stimulated release of TNF-α, IL-6 and IL-8 from HaCaT cells. The ELISA assay demonstrated that the concentrations of TNF-α, IL-6 and IL-8 in the supernatants of LPS-stimulated cells were reduced from 208.06±30.18, 86.4±9.78 and 260.59±54.05 pg/mL to 121.78±22.26, 53.18±7.36 and 125.08±35.17 pg/mL, respectively, in the supernatants of cells treated by LPS and EP combined. Real-time PCR also revealed that the expression of the three pro-inflammatory CKs was significantly decreased after EP intervention. Immunofluorescence confocal laser scanning microscopy showed that NF-κB p65 protein was primarily expressed in the cytoplasm of non-stimulated HaCaT cells. After LPS stimulation, NF-κB p65 was translocated into the nucleus, and the nuclear expression of this protein increased. The nuclear NF-κB p65 protein expression was inhibited after the addition of EP. Western blotting showed that IκB-α expression began to decrease 30 min after LPS stimulation and declined to a trough 4 h later. IκB-α expression began to gradually recover 16 h after LPS stimulation but remained at a lower-than-normal level at 24 h. Greater IκB-α expression was found in cells treated with LPS and EP combined than those treated with LPS alone. It was concluded that EP can effectively inhibit the LPS-stimulated expression of TNF-α, IL-6, and IL-8, which involves the inhibition of the hydrolysis of IκB-α and thereby blockage of the nuclear translocation of NF-κB p65.
摘要
The forkhead family members of transcription factors (FoxOs) are expected to be potential cancer-related drug targets and thus are being extremely studied recently. In the present study, FoxO3a, one major member of this family, was identified to be down-regulated in colorectal cancer through micro-array analysis, which was confirmed by RT-PCR and Western blot in 28 patients. Moreover, immunohistochemistry (IHC) showed that the expression levels of FoxO3a were remarkably reduced in 99 cases of primary colorectal cancer, liver metastasis, and even in metaplastic colorectal tissue. IHC also revealed an exclusion of FoxO3a from the nucleus of most cells of tumor-associated tissues. Silencing FoxO3a by siRNA led to elevation of G2-M phase cells. We conclude that the downregulation of FoxO3a may greatly contribute to tumor development, and thus FoxO3a may represent a novel therapeutic target in colorectal cancer.
Subject(s)
Female , Humans , Male , Cell Cycle Checkpoints , Colon , Metabolism , Pathology , Colorectal Neoplasms , Metabolism , Pathology , Down-Regulation , Forkhead Box Protein O3 , Forkhead Transcription Factors , Metabolism , Liver Neoplasms , Metabolism , Pathology , Metaplasia , Metabolism , Pathology , Rectum , Metabolism , Pathology , Tumor Cells, Cultured摘要
<p><b>OBJECTIVE</b>To investigate fluorescence in situ hybridization labeled with quantum dots (QDs) for the detection of human papillomavirus 16/18 (HPV16/18) infection in cervical carcinoma patients.</p><p><b>METHODS</b>A total of 80 biopsy samples of squamous carcinoma of cervix were assayed for HPV 16/18 infection by using quantum dot labeled fluorescent in situ hybridization (QD-FISH) and chromogenic in situ hybridization (CISH) techniques, respectively. The results obtained by using two different methods were statistically analyzed.</p><p><b>RESULTS</b>The positive rate for HPV16/18 by QD-FISH was 88.8% (71/80), higher than that (80.0%) by CISH, however, the result was statistically not significant (P=0.127). The positive detection rates for HPV16/18 by using both methods increased coincidentally with raising of the tumor grading stage.</p><p><b>CONCLUSION</b>The sensitivity and specificity of HPV infection detectable by QD-FISH is higher than that by the CISH technique.</p>
Subject(s)
Adult , Female , Humans , Middle Aged , Carcinoma, Squamous Cell , Pathology , Virology , Uterine Cervical Dysplasia , Pathology , Virology , Chromogenic Compounds , Human papillomavirus 16 , Human papillomavirus 18 , In Situ Hybridization, Fluorescence , Methods , Papillomavirus Infections , Virology , Quantum Dots , Sensitivity and Specificity , Uterine Cervical Neoplasms , Pathology , Virology摘要
<p><b>OBJECTIVE</b>To elucidate the effect of hSav1 expression on Mst1-mediated apoptosis in HeLa cells.</p><p><b>METHODS</b>Plasmids pCMV-HA-hSav1 and pcDNA/4TO-Flag-Mst1 were constructed and cotransfected into HeLa cells. Triple immunofluorescent labeling of hSav1, Mst1 and nucleus was performed to determine their subcellular localization. Plasmids pCMV-HA-hSav1 and/or pcDNA/4TO-Flag-Mst1 were transfected into HeLa cells, and 36 hours later cisplatin (50 micromol/L) as a pro-apoptotic agent was added for 14 hours. Cell apoptosis was analyzed by annexin V/PI assay.</p><p><b>RESULTS</b>Plasmids pCMV-HA-hSav1 and pcDNA/4TO-Flag-Mst1 were constructed and the authenticity of constructs was verified by sequencing. The binding in vitro showed that hSav1 could be detect from the anti-Mst1 immunoprecipitation complex. The immunofluorescent labeling showed that hSav1 and Mst1 had the same localization in cells. Overexpressed protein hSav1 did not induce a significant cell apoptosis. However, co-expression of hSav1 with Mst1 resulted in a significant increase of apoptosis above the level seen with Mst1 alone (24.5% +/- 2.4% vs. 39.3% +/- 4.0%, P < 0.05).</p><p><b>CONCLUSION</b>Our findings indicate that hSav1 is a newly identified protein that interacts with Mst1 and augments Mst1-mediated apoptosis.</p>
Subject(s)
Humans , Apoptosis , Cell Cycle Proteins , Genetics , Metabolism , Cytoplasm , Metabolism , HeLa Cells , Hepatocyte Growth Factor , Genetics , Metabolism , Plasmids , Proto-Oncogene Proteins , Genetics , Metabolism , Transfection摘要
<p><b>OBJECTIVE</b>To explore a method which can remove the gastric mucus in order to prepare mucous membrane single cell suspension for the research of cytomics.</p><p><b>METHODS</b>Enzymology was used to remove the mucus gel and to separate mucous layer from the normal fresh gastric tissue. The mucous layer was broken to prepare single cell suspension with machine method. Expression of major cyclins in mucous layer cells was examined by cytoimmunochemistry, flow cytometry(FCM) and confocal microscopy.</p><p><b>RESULTS</b>The 0.1% pepsin could dissolve the mucus gel and 1.2-2.4 U/L dispase could separate the mucous layer completely. The single mucous cell suspension was prepared successfully. FCM results from mucous single cell suspension revealed that expression of cyclin D(3), B(1) was obvious, that of cyclin D(2) was weak and that of cyclin D(1), A, E was the least. Similar results were found with confocal microscopy.</p><p><b>CONCLUSIONS</b>Single cell suspension from mucous layer can be easily prepared by pepsin and dispase. Cyclins schedule expression in vivo is different from cyclins schedule expression in vitro.</p>
Subject(s)
Humans , Cell Line , Cell Proliferation , Cyclins , Metabolism , Flow Cytometry , Gastric Mucins , Metabolism , Gastric Mucosa , Cell Biology , Metabolism , Mucous Membrane , Cell Biology , Metabolism摘要
<p><b>OBJECTIVE</b>To explore the molecular elements responsible for the enhanced apoptotic susceptibility in U937 cells mediated by silencing atactic telangiectasis mutation (ATM) gene.</p><p><b>METHODS</b>Two U937 cell mutants, U937-ASPI3K (ATM gene negative) and U937-pZEOSV2 (+) (ATM gene positive) were used as a cell model system. Apoptosis was examined by measuring free nucleosome concentrations in U937 cells. Western blotting was employed to measure nuclear protein abundances of cdc25A, cdc25B, cdc25C, total p34cdc2, p34cdc2 (Thr161) or p34cdc2 (Thr14, Tyr15). RT-PCR was used to estimate cdc25 transcript levels.</p><p><b>RESULTS</b>U937-ASPI3K exhibited an enhanced apoptotic susceptibility to lower dosage of irradiation, which could not be blocked by protein synthesis inhibitor. Protein serine-theronine phosphatase inhibitor or cyclin-dependent kinase (CDK) inhibitors could abolish the enhancement. Upon irradiation, p34cdc2 in U937-pZEOSV2 (+) was in an inactive state owing to phosphorylation of Thr 14 and Tyr15, which was associated with a dramatic decrease of nuclear cdc25A, cdc25B and cdc25C poteins. In contrast, p34cdc2 in U937-ASPI3K was in an active state owing to the low phosphorylation of Thr14 and Tyr15, which was associated with constant nuclear cdc25A, cdc25B and cdc25C protein abundance before and after irradiation. The responsive decrease of nuclear cdc25 proteins occurred at the post-transcription level.</p><p><b>CONCLUSION</b>Silencing ATM gene blocks the irradiation induced responsive decrease of nuclear cdc25 proteins, resulting in an abnormal activation p34cdc2 is the critical molecular mechanism for the enhanced apoptotic responses.</p>