A combination of STI571 and BCR-ABL1 siRNA with overexpressed p15INK4B induced enhanced proliferation inhibition and apoptosis in chronic myeloid leukemia

p15INK4B, a cyclin-dependent kinase inhibitor, has been recognized as a tumor suppressor. Loss of or methylation of the p15INK4B gene in chronic myeloid leukemia (CML) cells enhances myeloid progenitor formation from common myeloid progenitors. Therefore, we examined the effects of overexpressed p15INK4B on proliferation and apoptosis of CML cells. Overexpression of p15INK4B inhibited the growth of K562 cells by downregulation of cyclin-dependent kinase 4 (CDK4) and cyclin D1 expression. Overexpression of p15INK4B also induced apoptosis of K562 cells by upregulating Bax expression and downregulating Bcl-2 expression. Overexpression of p15INK4B together with STI571 (imatinib) or BCR-ABL1 small interfering RNA (siRNA) also enhanced growth inhibition and apoptosis induction of K562 cells. The enhanced effect was also mediated by reduction of cyclin D1 and CDK4 and regulation of Bax and Bcl-2. In conclusion, our study may provide new insights into the role of p15INK4B in CML and a potential therapeutic target for overcoming tyrosine kinase inhibitor resistance in CML.

Expression of Fas, bcl-2, Caspase 3 and Annexin-V in NB4 cell line treated with STI571 in vitro / 白血病·淋巴瘤

Objective To explore molecular mechanisms of apoptosis induced by STI571 in human acute promyelocytie 1eukemia cell lines NB4.nethods The expression of Annexin-V,Fas,Caspase-3 and bcl-2 in NB4 cells were detected by FCM after the treatment of STI571 at(0.5,1.0,5.0 μmol/L)ranging for 24 h,48 h and 72 h.Results With the increasing dose of STI571,the expression of bcl-2,Caspase-3,Annexin-V,Fas in NB4 changed from(10.22±0.62)declining to (5.82±0.52),from(42.21±1.02)ascending to(52.35±0.83),from(25.A2±1.21)ascending to(37.84±0.63),from(18.21±0.81)to(21.41±1.02)respectively.With the dealing time increasing(24,48,72 h),the expression of bcl-2,Caspase-3,Annexin-V,Fas in NB4,changed from (5.81±0.52)declining to(2.51±0.43),from(52.31±0.83)ascending to(69.51±1.12),from(37.81±0.93)ascending to(78.62±0.83),from(23.41±0.73)to(26.53±1.02)respectively.Conclusion STI571 can enhance the apoptosis program to Ni4 in a time-dependence and dose-dependence manner,but no change to Fas was observed.

STI 571 potentiates the sensitivity of non-small cell lung cancer cell line A549 to cytotoxic effects of cisplatin in vitro / 肿瘤

Objective: This study was designed to compare the effects of STI 571 on proliferation, cell phases, and apoptosis between A549 and cisplatin-resistant A549 cells (A549/DDP) and detect the expressions of STI 571-related receptors in non-small cell lung cancer (NSCLC) tissues. Methods: A549 and cisplatin-resistant A549 cells (A549/DDP) were cultured in vitro. The cell proliferation was measured by MTT assay. Cell cycle distribution and apoptosis induced by STI 571, cisplatin and their combination were detected by flow cytometry in NSCLC cell lines. The expressions of platelet-derived growth factor receptor (PDGFRs) -α and-β and c-KIT in the non-small cell lung cancer cell lines and tissues were investigated by immunocytochemistry and immunchistochemistry, respectively. Kaplan-Meier survival curves were used to compare the correlation of PDGFR-α and-β expression with total survival of NSCLC patients. Results: STI 571 inhibited proliferation of A549/DDP cells, sensitized them to cisplatin chemotherapy, increased the cell number in G2/M and S phase, and induced apoptosis. However, STI 571 at the concentration below 10 μmol/L had no effect on the proliferation of A549 cells. Both A549 and A549/DDP cells expressed PDGFR-α and-β, but c-KIT expression was only observed in A549/DDP cells. The expression rates of PDGFR-α and-β were 65.5% and 69% in pulmonary adenocarcinoma, similar to those in squamous carcinoma (70.4% and 74.1%). Only one case of squamous carcinoma expressed c-Kit (3.7%). The PDGFR-α or β-positive patients had similar 3-year survival rates and overall survival time with the PDGFRα or β-negative patients. Conclusion: ST1 571 could suppress proliferation of A549/DDP cells, induce apoptosis and increase the sensitivity of A549/DDP to cisplatin. The levels of PDGFRα and β expression did not correlate with the prognosis of NSCLC patients.

Effect on Cell Cycle Progression by N-Myc Knockdown in SK-N-BE(2) Neuroblastoma Cell Line and Cytotoxicity with STI-571 Compound / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Neuroblastoma is a common tumor in childhood, and generally exhibits heterogeneity and a malignant progression. MYCN expression and amplification profiles frequently correlate with therapeutic prognosis. Although it has been reported that MYCN silencing causes differentiation and apoptosis in human neuroblastoma cells, MYCN expression influences the cytotoxic potential of chemotherapeutic drugs via the deregulation of the cell cycle. STI-571 may constitute a promising therapeutic agent against neuroblastoma, particularly in cases in which c-Kit is expressed preferentially in MYCN-amplified neuroblastoma. MATERIALS AND METHODS: To determine whether STI-571 exerts a synergistic effect on cytotoxicity with MYCN expression, we assessed apoptotic cell death and cell cycle distribution after 72 h of exposure to STI-571 with or with out treatment of SK-N-BE(2) neuroblastoma cells with MYCN siRNA. RESULTS: MYCN siRNA-treated SK-N-BE(2) cells did not affect apoptosis and cells were arrested in G0/G1 phase after STI-571 treatment. CONCLUSIONS: siRNA therapy targeted to MYCN may not be effective when administered in combination with STI-571 treatment in cases of neuroblastoma. Therefore, chemotherapeutic drugs that target S or G2-M phase may prove ineffective when applied to cells arrested in the G0/1 phase as the result of MYCN knockdown and STI-571 treatment.

The study about apoptosis of STI571 on NB4 in vitro / 肿瘤研究与临床

Objective This study was designed to explore the influence about apoptosis of STI571 on NB4.Methods After NB4 cells were treated with STI571 in different concentration(0.5,1.0,5.0umol/L)at indicated time(24h,48h,72h)(1)morphological observation:To determine cell morphology by light microscope.(2)MTT assay:Inhibition of proliferation was measured with a colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-dipheny tetrazolium bromide(MYa3 assay.(3)Flow cytometric analysis:The expression of survivin and smac were measured on NB4 by FCM.Results Morphological observation showed characteristic apoptosis changes.MTT assay showed that STI at (0.5,1.0,5.0 μmol/L) range for 24 h,48 h and 72 h can markedly inhibit the proliferation of NB4 cells in a dose-dependent manner as well as a time-dependent manner(P＜0.05).FCM showed the expression of survivin decrease and smac increase.Conclusion STI571 In Vitro inhibits proliferation of NB4.

A Case of Drug Eruption with Periorbital Edema and Exfoliative Dermatitis Induced by Imatinib Mesylate (STI571, Gleevec(TM)) / 대한피부과학회지

STI571 (imatinib mesylate, Gleevec(TM)), a selective inhibitor of the bcr-abl, c-kit, platelet-derived growth factor receptor tyrosine kinases, is a new anticancer drug used for chronic myelogenous leukemia and gastrointestinal stromal tumors. Cutaneous adverse reactions of periorbital edema and exfoliative dermatitis related to STI571 are rare and there have been no previous reports in the Korean literature. We herein report a case of periorbital edema and exfoliative dermatitis due to STI571 and discuss the possible mechanism of periorbital edema related to STI571.

A Clinical and Histopathological Study of Drug Eruptions Caused by STI571 / 대한피부과학회지

BACKGROUND: STI571, which is a selective inhibitor of the BCR-ABL tyrosine kinase, is a promising new drug for the treatment of patients with chronic myelogenous leukemia. But it has been noted that this drug is frequently associated with an adverse cutaneous reaction. OBJECTIVE: The purpose of this study was to find the clinical and histopathological characteristics of drug eruptions caused by STI571. METHOD: We reviewed the clinical records of 10 patients diagnosed as drug erupions caused by STI571. RESULT: The mean age was 36.4 years and it was observed predominantly in females as the sex ratio of 7: 3. The most common clinical type was exanthematous eruption(70%), and followed by erythema multiforme-like eruption(20%), urticarial eruption(10%). In most cases(90%), the distribution was generalized, which involved trunk and extremities. The mean latent period was 17.1 days and peak incidence(70%) was noted between 1 and 2 weeks. Commonly associated adverse effects included fever(60%) and diarrhea(30%). Histopathologically, common findings included perivascular inflammatory cell infiltration(100%), eosinophil(80%), exocytosis(80%). CONCLUSION: Because drug eruptions caused by STI571 are dose-related and develop with a high frequency, we need a careful monitoring of patients who are treated with STI571, especially with a high dose.

A Clinical and Histopathological Study of Drug Eruptions Caused by STI571 / 대한피부과학회지

BACKGROUND: STI571, which is a selective inhibitor of the BCR-ABL tyrosine kinase, is a promising new drug for the treatment of patients with chronic myelogenous leukemia. But it has been noted that this drug is frequently associated with an adverse cutaneous reaction. OBJECTIVE: The purpose of this study was to find the clinical and histopathological characteristics of drug eruptions caused by STI571. METHOD: We reviewed the clinical records of 10 patients diagnosed as drug erupions caused by STI571. RESULT: The mean age was 36.4 years and it was observed predominantly in females as the sex ratio of 7: 3. The most common clinical type was exanthematous eruption(70%), and followed by erythema multiforme-like eruption(20%), urticarial eruption(10%). In most cases(90%), the distribution was generalized, which involved trunk and extremities. The mean latent period was 17.1 days and peak incidence(70%) was noted between 1 and 2 weeks. Commonly associated adverse effects included fever(60%) and diarrhea(30%). Histopathologically, common findings included perivascular inflammatory cell infiltration(100%), eosinophil(80%), exocytosis(80%). CONCLUSION: Because drug eruptions caused by STI571 are dose-related and develop with a high frequency, we need a careful monitoring of patients who are treated with STI571, especially with a high dose.

Accelerated Phase Chronic Myeloid Leukemia in Complete Molecular Response with STI571 / 대한혈액학회지

STI571 is an effective agent for the patients with chronic myeloid leukemia (CML). But, complete molecular response with STI571 is rarely reported in accelerated phase CML. Here we report a patient with accelerated phase CML who achieved complete molecular response with STI571. A 60-year old female patient visited emergency room with syncope. Her white blood cell count was 30,800/microliter (basophil 23%), hemoglobin 8.9g/dL, and platelet counts 2,748,000/microliter. Bone marrow was hypercellular with increase in megakaryocyte and basophils (15%). She was diagnosed as an accelerated phase CML. Seven days after stopping hydroxyurea, we used STI571 in a daily oral dose of 600mg. Generalized edema and skin rash were observed 15 days after treatment (all grade 1) and were controlled well with conservative management. Complete hematologic and cytogenetic responses were achieved after 1 month and 3 months of therapy with STI571 respectively. Complete molecular response was simultaneously proven by conventional reverse transcriptase PCR and real-time PCR analysis. The patient still remained in complete hematologic, cytogenetic, and molecular responses for 24 months. Treatment with STI571 was well tolerated and rapid hematologic improvement was observed. This case shows STI571 can induce complete molecular response as well as cytogenetic response in accelerated phase CML.

Clinical and Molecular Response of STI571 in Patients with Advanced Chronic Myelogenous Leukemia / 대한혈액학회지

BACKGROUND: STI571, a potent and specific inhibitor of the BCR-ABL tyrosine kinase, causes arrest of growth or apoptosis in leukemic cells that express BCR-ABL. We evaluated the therapeutic effects and clinical events after the STI571 treatment in advanced chronic myelogenous leukemia (CML). METHODS: STI571 was administered orally to 24 patients with CML in accelerated phase (AP) (N=17) or blast crisis (BC) (N=7) with a daily dose of 600mg. Adverse events were observed, and hemotologic, cytogenetic, and molecular responses were evaluated on 1 month of STI571 treatment. RESULTS: Hematologic responses were observed in 20 of 24 patients with higher complete hematologic responses in AP (35.3%) compared to BC (14.3%). Partial cytogenetic responses were observed in 2 cases. Fluorescence in situ hybridization showed significant decrease in the percentage of BCR-ABL positive cells, but all still remained above the upper limit of normal range at the time of analysis. No significant changes were observed in BCR-ABL transcripts after treatment by reverse transcription polymerase chain reaction (PCR) and real-time quantitative PCR. Non- hematologic adverse events after STI571 treatment were minimal, whilst hematologic ones were significant with higher frequency in BC rather than AP. CONCLUSION: STI571 induced rapid and significant hematologic responses in patients with advanced CML and adverse events were tolerable. The fact that no responses were achieved in some of these advanced cases underlies the importance of earlier treatment with STI571 to prolong the survival.

Quantitative Assessment of Philadelphia Chromosome Using Interphase/Hypermetaphase FISH and Toxicity after STI571 Treatment in Chronic Myelogenous Leukemia / 대한혈액학회지

BACKGROUND: Chronic Myelogenous Leukemia (CML) is the first proven disease in which gene abnormality, t(9;22)(q34;q11) can cause the disease to occur in humans. Recently, targeted therapy with STI571 (GleevecTM), signal transduction inhibitor for BCR-ABL kinase was developed and can induce cytogenetic remission in patients with CML. Hypermetaphase-FISH (HMF)/Interphase-FISH (I-FISH, Fluorescence in situ hybridization) aiming specific chromosomal abnormalities are unambiguous quantitative molecular genetic methods for individual Philadelphia (Ph1) chromosome positive cells. We evaluated the change of Ph1 chromosome in CML patients during STI571 therapy using HMF/I- FISH. METHODS: Twenty one patients with CML were treated with STI571 which was provided from Norvatis pharmaceutical company as Expanded Access Program for Compassionate Use from May 2001 at the doses of 200-600 mg/day orally. Median age of this cohort was 37 years old and median follow up duration was 113 days (48~165 days). HMF or I-FISH using bone marrow or peripheral blood were performed on the sample at baseline, day 14, day 28 and then monthly. RESULTS: Complete cytogenetic responses which were assessed by HMF/I-FISH counting several hundreds cells were found in 8 of 21 patients. Among them, 4 of 10 chronic phase, 2 of 2 accelerate phase and 2 of 8 blastic crisis patients achieved cytogenetic complete response. One patient with blastic crisis was relapsed after achieving cytogenetic complete response. Grade III-IV thrombocytopenia and neutropenia were noticed in 8 and in 7 patients respectively, but there were no major bleeding episodes nor neutropenic fever. CONCLUSION: BCR-ABL tyrosine kinase inhibitor, STI571 was tolerable for patients with CML. The majority of patients achieved hematologic remission and 8 out of 21 patients achieved complete cytogenetic response regardless of their disease stage. Cytogenetic response of Ph1 chromosome can be quantified accurately with HMF/I-FISH.

Inhibitory effect of STI571 in combination with chemotheraputic drug on a multi-drug resistant leukemia cell line expressing bcr-abl / 中国癌症杂志

Purpose: To study new treatment of leukemia with both bcr-abl and mdrl positive. Methods: We detected the effect of STI571 ( 1 ?mol/L), an inhibitor of tyrosine kinase, in combination respectively with vincristine (VCR), daunorubicin (DNR), homoharringtonin( HHT) ( 10-4,10-5, 10-6, 10-7,10-8 mol/L) and DNR + arabinoside cytosine (Ara-C) of 1 mmol/L on a high tumorigenicity in nude mice multi drug-resistant leukemia cell line ( K562-n/VCR) by MTT method. Results: IC50 of VCR and VCR + STI571 were 127.28 ?mol/L, 1. 37 ?mol/L respectively, and synergistic interaction on K562-n/VCR cells was 93. 04-fold. IC50 of DNR and DNR + STI571 were 6. 96?mol/L, 0. 30?mol/L respectively, synergistic interaction was 23. 35-fold. IC50 of HHT and HHT + STI571 were 156.70?mol/L, 7.916?mol/L respectively, synergistic interaction was 19. 80-fold. IC50 of DNR + Ara-C and DNR + Ara-C + STI571 were 0. 10 ?mol/L, 0. 015 ?mol/L respectively, the synergistic interaction was 464-fold. Chemotheraputic agents have not intensive cytotoxic effect on K562-n/VCR cells, but the cytotoxic effect became greater when combined with STI571. Conclusions: Combination of STI571 with DNR, VCR, HHT and DNR + Ara-C had a greater synergistic inhibiting effect on K562-n/ VCR cells . The combinations of STI571 and these Chemotheraputic agents would display synergistic activity in bcr-abl and mdrl positive leukemia cells.