Insulin-like growth factor 2 targets IGF1R signaling transduction to facilitate metastasis and imatinib resistance in gastrointestinal stromal tumors

BACKGROUND Gastrointestinal stromal tumors(GISTs)are typical gastrointestinal tract neoplasms.Imatinib is the first-line therapy for GIST patients.Drug resistance limits the long-term effectiveness of imatinib.The regulatory effect of insulin-like growth factor 2(IGF2)has been confirmed in various cancers and is related to resistance to chemotherapy and a worse prognosis.AIM To further investigate the mechanism of IGF2 specific to GISTs.METHODS IGF2 was screened and analyzed using Gene Expression Omnibus(GEO:GSE225819)data.After IGF2 knockdown or overexpression by transfection,the phenotypes(proliferation,migration,invasion,apoptosis)of GIST cells were characterized by cell counting kit 8,Transwell,and flow cytometry assays.We used western blotting to evaluate pathway-associated and epithelial-mesenchymal transition(EMT)-associated proteins.We injected transfected cells into nude mice to establish a tumor xenograft model and observed the occurrence and metastasis of GIST.RESULTS Data from the GEO indicated that IGF2 expression is high in GISTs,associated with liver metastasis,and closely related to drug resistance.GIST cells with high expression of IGF2 had increased proliferation and migration,invasiveness and EMT.Knockdown of IGF2 significantly inhibited those activities.In addition,OEIGF2 promoted GIST metastasis in vivo in nude mice.IGF2 activated IGF1R signaling in GIST cells,and IGF2/IGF1R-mediated glycolysis was required for GIST with liver metastasis.GIST cells with IGF2 knockdown were sensitive to imatinib treatment when IGF2 overexpression significantly raised imatinib resistance.Moreover,2-deoxy-D-glucose(a glycolysis inhibitor)treatment reversed IGF2 overexpressionmediated imatinib resistance in GISTs.CONCLUSION IGF2 targeting of IGF1R signaling inhibited metastasis and decreased imatinib resistance by driving glycolysis in GISTs.

The Combination Effect of Daphne Extract and Imatinib on the Antiproliferative Activity of the K562 Cell Line

Background: Herbal medicine is well-known among the ancient medical sciences. Healing properties have been observed in some species of Daphne plant. The effect of Daphne plant extract on the K562 cell line has been previously studied, and Gleevec is a well-known and effective medicine for the treatment of chronic myelogenous leukemia. Material and Methods: In this study, the simultaneous effects of using herbal medicine and a target therapy medicine on the K562 cell line were investigated. The presence of some species of Daphne in Iran motivated us to evaluate the cytotoxic effect of Daphne mucronata on human leukemia cancer cells. The antiproliferative activity of the dichloromethane extract of Daphne mucronate (Thymelaeaceae), a new anticancer medicinal plant, was evaluated. Cell viability was quantitated by MTT assay. Apoptotic and necrotic changes in the cell membrane were examined using flow cytometry. Changes in Bax and Bcl2 gene expression were investigated using real-time PCR. The MIC and the IC50 of the crude extract were calculated, and the MIC and IC50 of the Daphne extract in combination of imatinib were tested in the K-562 cell line. Results: K-562 cells responded to the extract treatments in a dose-dependent manner, and the increase in the expression of Bcl2 and decrease in the expression of the Bax gene intensified with increasing extract concentration. Flow cytometry revealed that most of the cells underwent necrosis. Conclusion: Daphne extract effectively decreased the viability of the K562 cell line. The necrotic effect of the Daphne extract was evaluated, and an increase in the gene expression of Bcl2 was observed in cells exposed to the Daphne extract. The combination of Daphne extracts with imatinib enhances the cytotoxic effect of imatinib.

甲异靛联合imatinib对CML K562细胞的促凋亡作用

目的研究甲异靛联合imatinib促进K562细胞凋亡的作用。方法K562细胞经imatinib或/和甲异靛处理48h后,采用流式细胞术检测细胞凋亡相关指标(线粒体跨膜电位和AnnexinV/PI)的改变,ELISA方法检测caspase3活性改变,Westernblot检测凋亡相关蛋白(cytC,cIAP1,procaspase3和PARP)的改变。结果与单用组相比,20μmol/L甲异靛与0.3μmol/Limatinib联合应用后,线粒体跨膜电位下降细胞比例明显升高,cytC释放入胞浆,caspase3酶原形式procaspase3减少,caspase3活性升高,其底物PARP被降解,AnnexinV水平升高。结论甲异靛与imatinib合用可协同促进K562细胞凋亡。

Combination of Rapamycin and Imatinib in Treating Refractory Chronic Myeloid Leukemia Myeloid Blast Crisis:a Case Report

HRONIC myeloid leukemia （CML） is characterized by the presence of the BCR/ABL fusion gene, which is the result of a reciprocal translo cation between chromosomes 9 and 22, calledPhiladelphia （Ph） chromosome. Imatinib mesylate （imatinib）, a specific small molecular inhibitor of BCR/ABL, could improve the prognosis of CML and is now the standard drug applied in all phases of this disease} Despite the efficacy of imatinib, the development of resistance and the persistence of minimal residual disease have seriously impaired the efficiency of this medicine. Resistance may develop through several different mechanisms, such as mutations in the Abl kinase domain, BCR/ABL overexpression, or compensatory phosphatidylinositol 3 kinase （PI3K）/Akt/ mammalian target of rapamycin （mTOR） activation.2,3 Rapamycin, with mTOR as a potential therapeutic target, has been studied in patients with hematologic malignancies. Here we report a case of refractory CML myeloid blast crisissuccessfully treated by the combination of rapamycin and imatinib.

Imatinib治疗转移性、不能手术切除的胃肠间质瘤

1文献类型治疗2证据水平2b3文献来源Demetri G D, Mehren M V, Blanke C D, et al.Efficacy and safety of imatinib mesylate in advanced gastrointestinal stromal tumors [J]. N Engl J Med,2002。

动力学方法研究Imatinib与蛋白激酶的结合构象与结合自由能

对imatinib两种典型复合物晶体结构imatinib-Abl与imatinib-c-Kit进行比对分析,并利用MM/PBSA方法计算imatinib与Abl、c-Kit、c-Src、p38及Syk等激酶的结合自由能.计算结果表明,imatinib与上述激酶结合时,范德华作用对结合自由能有主要贡献;其中,imatinib与激酶c-Kit结合自由能最低;imatinib与非活性构象激酶的结合自由能明显低于与活性构象激酶的结合自由能.

胃肠间质瘤患者中Imatinib血药浓度与治疗疗效的相关性

目的检测中国晚期胃肠间质瘤(GIST)患者中伊马替尼(Imatinib)血药浓度,并分析血药浓度与治疗疗效的相关性。方法收集112例接受Imatinib治疗超过28 d的GIST患者的117份血浆样本,用HPLC-MS/MS法检测血浆中Imatinib浓度。分析Imatinib血药浓度与治疗疗效的相关性。结果高剂量组(600 mg/d)患者的血药浓度较低剂量组(400 mg/d)明显升高(P<0.001)。服药时间为1～2年患者的血药浓度(平均值1 268 ng/mL)较服药时间小于1年的患者(平均值1 845 ng/mL)明显降低(P<0.05)。随着血药浓度的增加有效率也随之增加,血药浓度低、中及高水平组的有效率分别为50%、67.5%及66.7%。结论 Imatinib血药浓度与服药剂量及服药时间明显相关;Imatinib治疗有效率随着血药浓度的增高呈增加趋势。

imatinib对大鼠SAH后早期颅脑损伤的影响

目的研究imatinib对蛛网膜下腔出血后早期颅脑损伤的作用及相关机制。方法收集160只Wistar大鼠,先将98只大鼠分为假手术组(n=20)、SAH组(n=26)、SAH+imatinib组(n=26)、SAH+imatinib+LY294002组(n=26)。采用血管内穿刺法制作SAH模型,假手术组不刺破血管,其余操作相同。再将30只SAH大鼠分为control si RNA组(n=10)、c-Abl si RNA组(n=10)和c-Abl si RNA+imatinib组(n=10)。计算各组大鼠的病死率,采用Western blot检测p-PDGFRα、c-Abl、p-Akt、p-GSK3β蛋白水平,Tunel荧光法检测神经元凋亡,评价出血后24、72 h各组大鼠SAH严重程度、神经评分;另取32只大鼠用于检测出血后48 h脑组织含水量,伊文思蓝检测血-脑屏障通透性变化。结果 imatinib显著降低出血后24 h病死率及神经元凋亡,减轻脑水肿,减少出血后48 h伊文思蓝渗出,提高72 h后神经评分(P <0.05),但不减少出血量。出血24 h后pPDGFRα、c-Abl蛋白表达显著增加,p-Akt、p-GSK3β表达稍增加(P <0.05),imatinib显著下调p-PDGFRα、c-Abl表达,上调p-Akt、p-GSK3β的表达(P <0.05),LY294002可拮抗imatinib作用(P <0.05)。沉默c-Abl基因表达,p-GSK3β、p-Akt的表达显著增加,神经元凋亡明显减少(P <0.05),在此基础上使用imatinib对p-GSK3β、p-Akt蛋白表达及凋亡无影响(P>0.05)。结论 imatinib减轻SAH早期颅脑损伤,改善神经功能,可能与抑制c-Abl、增加Akt/GSK3β磷酸化有关。

Efficacy of imatinib dose escalation in Chinese gastrointestinal stromal tumor patients

AIM： To investigate the efficacy and safety of imatinib dose escalation in Chinese patients with advanced gas- trointestinal stromal tumor （GIST）.

A validated UPLC–MS/MS method for simultaneous determination of imatinib, dasatinib and nilotinib in human plasma

A sensitive, rapid, simple and economical ultra-performance liquid chromatography-tandem mass spectrometric method （UPLC-MS/MS） was developed and validated for simultaneous determination of imatinib, dasatinib and nilotinib in human plasma using gliquidone as internal standard （IS）. Liquid-liquid extraction method with ethyl acetate was used for sample pre-treatment. The separation was performed on an Xtimate Phenyl column using isocratic mobile phase consisting of A （aqueous phase： 0.15% formic acid and 0.05% ammonium acetate） and B （organic phase： aeetonitrile） （A：B=40：60, v/v）. The flow rate was 0.25 mL/min and the total run time was 6 min. The multiple reaction monitoring （MRM） transitions, m/z 494.5-394.5 for imatinib, 488.7-401.5 for dasatinib, 530.7-289.5 for nilotinib and 528.5-403.4 for IS, were chosen to achieve high selectivity in the simultaneous analyses. The method exhibited great improvement in sensitivity and good linearity over the concentration range of 2.6-5250.0 ng/mL for imatinib, 2.0-490.0 ng/mL for dasatinib, and 2.4-4700.0 ng/mL for nilotinib. The method showed acceptable results on sensitivity, specificity, recovery, precision, accuracy and stability tests. This UPLC-MS/MS assay was successfully used for human plasma samples analysis and no significant differences were found in imatinib steady-state trough concentrations among the SLC22A5 -1889T 〉 C or SLCOIB3 699G 〉 A genotypes （P 〉 0.05）. This validated method can provide support for clinical therapeutic drug monitoring and pharmacokinetic investigations of these three tyrosine kinase inhibitors （TKIs）.

Effect of PDGF-Rb antagonist imatinib on endometrial injury repairing in mouse model

Objective: To study the effects of PDGF-Rb antagonists imatinib on endometrial injury repairing in the mouse model. Methods: The cultured MSCs cells from male mice were marked with Brd U in vitro, and then transplanted to the female mice which suffered from radiation injury through tail vein, PDGF-Rb antagonists imatinib was injected through abdominal cavity. Four groups were arranged, which were radiation transplantation group, normal control group, imatinib intervention group and radiation control group. Brd U incorporation, SRY expression and MVD status were detected in uterus of mice. Results: SRY gene was negative expressed in normal control group and radiation control group. SRY gene presented positive in radiation transplantation group and imatinib intervention group; Brd U incorporation showed negative in radiation control group and normal control group which died in the early stage in mice; the incorporation of Brd U was higher in radiation transplantation group compared with imatinib intervention group; CD34 was positive on the uterus of all the four groups,which showed highest in radiation control group and lowest in radiation control group; The MVD in imatinib intervention group was lower than radiation control group; the difference of MVD was significantly compared with normal control group(P<0.05). Conclusions: PDGF-Rb antagonists imatinib could inhibit the repairing function of MSCs in the endometrial lesions in mice.

Imatinib as preoperative therapy in Chinese patients with recurrent or metastatic GISTs

Objective： Imatinib has dramatically altered the options for management of patients with gastrointestinal stromal turnouts. However, it has become clear that secondary resistance to the drug develops during long- term therapy. The purpose of our study was to retrospectively analyze safety and long-term outcomes in Chinese patients with recurrent or metastatic GISTs treated with imatinib preoperatively. Methods： Between June 2003 and June 2011, 22 patients underwent surgery for recurrent or metastatic GISTs after preoperative treatment with imatinib. Results： Complete resection was accomplished in 8 of the 10 responsive disease （RD） patients （80%）, and in 3 of the 12 patients （25%） who had progression disease （PD）. The amount of blood loss during the operation in PD patients was higher than in RD patients. There was 1 hospital death in PD group related to surgery, while the other patients recovered with conservative therapy because complications were mild. The difference in median PFS between patients with RD and those with PD was significant （24.8 vs. 2.81 months, P〈0.001）. The difference in 2-year OS rate between patients with RE） and those with PD was not significant （100% vs. 87.5%, P〉0.05）. Conclusions： Our study indicates that surgical intervention can improve the PFS of Chinese patients with recurrent or metastatic GISTs responsive to imatinib, but does not prolong OS as well as in patients who develop imatinib resistance. Surgical resection following imatinib treatment is feasible and can be considered for patients with advanced GISTs responsive to imatinib.

光谱及分子模拟法对HSA和BSA与酪氨酸激酶抑制剂Imatinib相互作用的比较分析

研究一种酪氨酸激酶抑制剂(tyrosine kinase inhibitor,TKI)伊马替尼(imatinib,IMA)与人血清清蛋白(HSA)及牛血清清蛋白(BSA)的相互作用,比较分析HSA和BSA与IMA相互作用机制的差异.模拟生理条件下,计算机模拟技术结合荧光光谱和紫外光谱法,研究IMA与蛋白质的作用机制.分子模建IMA与血清清蛋白的结合模型,表明伊马替尼与蛋白质的相互作用力为疏水作用力,兼有氢键作用.光谱结果表明,IMA与HSA和BSA的相互作用表现为静态结合过程,结合强度较强,IMA与HSA和BSA分子的结合距离r值较小,说明发生了能量转移现象.IMA对HSA和BSA的结构域微区构象产生影响,使结合位域的疏水性发生改变.荧光相图技术解析出IMA与HSA和BSA反应构象型态的变迁为"二态"模型.HSA与IMA相互作用的热力学参数表明,IMA与HSA之间是以疏水作用为主的分子间作用,而IMA与BSA之间的作用力为氢键和范德华力,兼有少量的疏水作用力.光谱实验与计算机模拟结果基本一致,可为研究IMA与HSA和BSA相互作用本质提供一定参考.

Pathologic complete response confirmed by surgical resection for liver metastases of gastrointestinal stromal tumor after treatment with imatinib mesylate

A 39-year-old male underwent distal gastrectomy for a high grade gastrointestinal stromal tumor(GIST) . Computed tomography(CT) and magnetic resonance imaging(MRI) 107 mo after the operation,revealed a cystic mass(14 cm in diameter) and a solid mass(9 cm in diameter) in the right and left lobes of the liver,respectively. A biopsy specimen of the solid mass showed a liver metastasis of GIST. The patient received imatinib mesylate(IM) treatment,400 mg/day orally. Following the IM treatment for a period of 35 mo,the patient underwent partial hepatectomy(S4 + S5) . The effect of IM on the metastatic lesions was interpreted as pathologic complete response(CR) . Pathologically verified cases showing therapeutic efficacy of IM have been rarely reported.

Expression of c-kit receptor in human cholangiocarcinoma and in vivo treatment with imatinib mesilate in chimeric mice

AIM： To investigate the c-kit expression in biliary tract cancer cell lines and histological sections from patients with extrahepatic cholangiocarcinoma （CC） and to evaluate the efficacy of in vitro and in vitro treatment with imatinib mesilate. METHODS： The protein expression of c-kit in the human biliary tract cancer cell lines Mz-ChA-2 and EGI-1 and histological sections from 19 patients with extrahepatic CC was assessed by immunoblotting, immunocytochemistry, and immunohistochemistry. The anti-proliferative effect of imatinib mesilate on biliary tract cancer cell lines Mz-ChA-2 and EGI-1 was studied in vitro by automated cell counting. In addition, immunodeficient NMRI mice （Taconic^TM） were subcutaneously injected with 5 × 10^6 cells of cell lines MzChA-2 and EGI-1. After having reached a tumour volume of 200 mm^3, daily treatment was started intraperitoneally with imatinib mesilate at a dose of 50 mgikg or normal saline （NS）. Tumor volume was calculated with a Vernier caliper. After 14 d, mice were sacrificed with tumors excised and tumor mass determined.RESULTS： Immunoblotting revealed presence of c-kit in Mz-ChA-2 and absence in EGI-1 cells. Immunocytochemistry with c-kit antibodies displayed a cytoplasmatic and membraneous localization of receptor protein in Mz-ChA-2 cells and absence of c-kit in EGI-1 cells, c-kit was expressed in 7 of 19 （37%） extrahepatic humanCC tissue samples, 2 showed a moderate and 5 a rather weak immunostaining. Imatinib mesilate at a low concentration of 5 μmoliL caused a significant growth inhibition in the c-kit positive cell line Mz-ChA-2 （31%）, but not in the c-kit negative cell line EGI-1 （0%） （P〈0.05）. Imatinib mesilate at an intermediate concentration of 10 μmoliL inhibited cellular growth of both cell lines （51% vs 57%）. Imatinib mesilate at a higher concentration of 20 μmoliL seemed to have a general toxic effect on both cell lines. The IC50 values were 9.7 μmoliL and 11 μmoliL, respectively. After 14 d of in vitro treatment with imatinib mesilate, using the chimeric mouse model, c-kit positive Mz-ChA-2 tumors had a significantly reduced volume and mass as compared to NS treatment （P〈 0.05）. In contrast to that, treatment of mice bearing c-kit negative EGI-1 tumors did not result in any change of tumor volume and mass as compared to NS treatment. CONCLUSION： c-kit expression is detectable at a moderate to low protein level in biliary tract cancer. Imatinib mesilate exerts marked effects on tumor growth in vitro andin vitro dependent on the level of c-kit expression.

Early detection of response to imatinib therapy for gastrointestinal stromal tumor by using 18F-FDG-positron emission tomography and computed tomography imaging

A 41-year old female with metastatic gastrointestinal stromal tumor was referred to 18F-FDG-positron emission tomography and computed tomography （PET/CT） scan before and after one-month treatment with imatinib （Glivec, Gleevec, Novartis, Basel, Switzerland）, a tyrosine kinase inhibitor （400 mg/d）. Metabolic response was evaluated before and after one month of therapy. The decrease of the maximum standardised uptake value （SUV） was 79% （from 9.8 to 2.1）. Positron emission tomography demonstrated complete metabolic response after one-month of imatinib treatment. Additionally, the previous lesion was compared with the coronal computerized tomographic image. There was no difference in the size of the tumor before and after therapy according to CT images. However, metabolic activity was inhibited. 18F-FDG-PEr is a valuable method for the detection of response to one-month imatinib treatment in patients with gastrointestinal stromal tumors.

Imatinib-induced fatal acute liver failure

Imatinib mesylate is a drug that has been approved for treatment of chronic myeloid leukemia (CML) in blast crisis, accelerated or chronic phase, and also for advanced gastrointestinal stromal tumors. Severe hepatic toxicity and three deaths from hepatic failure have been reported. We report the case of a 51-year-old woman who was admitted to our institution with severe acute hepatitis. She was diagnosed with CML and began treatment with imatinib mesylate at a dose of 400 mg/d. Five months after beginning treatment, she developed severe hepatitis associated with coagulopathy, and was admitted to our institution. She had been consuming acetaminophen 500-1000 mg/d after the onset of symptoms. She had a progressive increase in bilirubin level and a marked decrease of clotting factor Ⅴ. Five days after admission, grade Ⅱ encephalopathy developed and she was referred for liver transplantation. Her clinical condition progressively deteriorated, and 48 h after being referred for transplantation she suffered a cardiac arrest and died. This report adds concern about the possibility of imatinib-mesylate-induced hepatotoxicity and liver failure, particularly in the case of concomitant use with acetaminophen. Liver function tests should be carefully monitored during treatment and, with the appearance of any elevation of liver function tests, treatment should be discontinued.

Imatinib mesylate in clinically suspected gastric stromal tumors

Gastrointestinal stromal tumors （GISTs） occur most frequently in the stomach.Diagnosis of gastric GIST is not always clear before surgery.Flexible endoscopy may suggest the nature of the lesion （a bulky tumor with preserved mucosa）; however,biopsy is rarely diagnostic.Therefore,diagnostic medication with safe drugs may provide a feasible way under such conditions after an informed consent is obtained.Based on the excellent efficacy of imatinib mesylate （IM） in the treatment of GIST,we successfully applied it in the diagnostic medication of two patients with clinically suspected gastric stromal tumors.In conclusion,the diagnostic medication with IM can be an alternative option for patients with suspected GIST that can not be confirmed pathologically.

Long-term survival of a case with multiple liver metastases from duodenal gastrointestinal stromal tumor drastically reduced by the treatment with imatinib and hepatectomy

Constitutive activation of KIT receptor tyrosine kinase is a critical factor in the pathogenesis of gastrointestinal stromal tumors （GISTs）. But there is little information on whether combination of imatinib mesylate （IM） and surgical treatment can prolong survival in the cases with unresectable multiple liver metastases. We report a case of postoperative recurrence of GIST treated by the tyrosine kinase inhibitor IN and surgical treatment. The initial complete response （CR） to treatment continued for 18 mo, but single liver metastasis showed regrowth in the left hepatic lobe during IN treatment. After partial resection of the recurrent tumor, postoperative course was uneventful and the patient has survived without recurrence for 24 too. Currently, imatinib is the first- line therapy for non-resectable GISTs, but a single agent therapy often leads to tumor resistance. Even if tolerance to imatinib occurs, a combination of imatinib and surgical treatment can prolong survival in some cases as reported here. However, further studies on a large number of cases of recurrent GIST are necessary to evaluate the effectiveness of IN treatment combined with surgery.

Advanced gastrointestinal stromal tumor patients with complete response after treatment with imatinib mesylate

AIM： Most gastrointestinal stromal tumors （GISTs） express constitutively activated mutant isoforms of kit kinase or platelet-derived growth factor receptor alpha （PDGFRA）, which are potential therapeutic targets for imatinib mesylate （Glivec）. Partial response occurred in almost two thirds of GIST patients treated with Glivec. However, complete response （CR） after Glivec therapy was sporadically reported. Here we illustrated advanced GIST patients with CR after Glivec treatment. METHODS： Between January 2001 and June 2005, 42 advanced GIST patients were treated with Glivec. Patients were administered 400 mg of Glivec in 100-mg capsules, taken orally daily with food. The response of the tumor to Glivec was evaluated after one month, three months, and every three months thereafter or whenever medical need was indicated. Each tumor of patients was investigated for mutations of kit or PDGFRA. RESULTS： The median follow-up time of the 42 ad-vanced GIST patients treated with Glivec was 16.9 months （range, 1.0- 47.0 months）. Overall, 3 patients had complete response CR （7.1%）, 26 partial response （67.8%）, 5 stationary disease （11.9%）, and 3 progressive disease （11.9%）. The median duration of Glivec administration for the three patients was 36 months （range, 23-36 months）. The median time to CR after Glivec treatment was 20 months （range, 9-26 months）. Deletion and insertion mutations of c-kit exon 11 and insertion mutation of c-kit exon 9 were found in two cases and one case, respectively. CONCLUSION： Complete response （CR） can be achieved in selected advanced GIST patients treated with Glivec. The median time to CR after Glivec treatment was 20 months. Deletion and insertion mutations of kit exon 11 and insertion mutation of kit exon 9 contribute to the genetic features in these selected cases.