• Journal of Cancer Prevention
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• v.23 no.4
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• pp.170-175
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• 2018

Background: Human hepatocellular carcinoma (HCC) is a common liver tumor and the main cause of cancer-related death. Tyrosine kinase inhibitors, such as imatinib and GNF5 which were developed to treat chronic myelogenous leukemia, regulate the progression of various cancers. The aim of this study was to confirm the anti-tumor activity of tyrosine kinase inhibitors through regulation of S-phase kinase-associated protein 2 (Skp2), an important oncogenic factor in various cancer cells, in human hepatocarcinoma SK-HEP1 cells. Methods: Cell viability and colony formation assays were conducted to evaluate the effects of imatinib, GNF5 and GNF2 on the growth of SK-HEP1 cells. Using immunoblot analysis, we assessed change of the activation of caspases, PARP, Akt, mitogen-activated protein kinases, and Skp2/p27/p21 pathway by imatinib and GNF5 in SK-HEP1 cells. Using sh-Skp2 HCC cells, the role of Skp2 in the effects of imatinib and GNF5 was evaluated. Results: Imatinib and GNF5 significantly inhibited the growth of SK-HEP1 cells. Treatment of imatinib and GNF5 decreased Skp2 expression and Akt phosphorylation, and increased the expression of p27, p21, and active-caspases in SK-HEP1 cells. In sh-Skp2 HCC cells, cell growth and the expression of Skp2 were inhibited by more than in the mock group treated with imatinib and GNF5. Conclusions: These results suggest that the anti-growth activity of tyrosine kinase inhibitors may be associated with the regulation of p27/p21 and caspases through Skp2 blockage in HCC cells.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.2
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• pp.93-100
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• 2022

Objective: The impact of imatinib, a tyrosine kinase inhibitor, on ovarian follicles and several proteins related to follicular function and apoptosis was investigated in mice. Methods: Saline, cyclophosphamide (Cp; 50 or 75 mg/kg), or imatinib (7.5 or 15 mg/kg) was injected once intraperitoneally into female B6D2F1 mice (18 mice in each group). In multiple ovarian sections, the number of various types of follicles and the proportion of good-quality (G1) follicles were counted. The levels of six proteins (anti-Müllerian hormone [AMH], BCL-xL, BAX, acid sphingomyelinase [A-SMase], caspase-3, and α-smooth muscle actin [α-SMA]) within the whole ovaries were quantified using Western blots. Results: Compared to the saline group, a significant reduction of the primordial follicle count was observed in the group treated with imatinib 7.5 and 15 mg/kg, as well as in the group treated with Cp 75 mg/kg. Administration of Cp significantly decreased the proportion of G1 primordial follicles, but administration of imatinib did not. No differences in the AMH, anti-apoptotic BCLX-L, pro-apoptotic BAX, and A-SMase levels in the ovarian tissues were observed among the five groups. However, caspase-3 and α-SMA levels were significantly higher in the imatinib and Cp groups than in the saline group. Conclusion: The administration of imatinib to mice significantly reduced the primordial follicle count and increased the protein levels of caspase-3 and α-SMA. Our findings suggest that imatinib potentially exerts ovarian toxicity via apoptotic processes, similarly to Cp.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.11
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• pp.4555-4561
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• 2014

Background: Silencing due to methylation of suppressor of cytokine signaling-3 (SOCS-3), a negative regulator gene for the JAK/STAT signaling pathway has been reported to play important roles in leukemogenesis. Imatinib mesylate is a tyrosine kinase inhibitor that specifically targets the BCR-ABL protein and induces hematological remission in patients with chronic myeloid leukemia (CML). Unfortunately, the majority of CML patients treated with imatinib develop resistance under prolonged therapy. We here investigated the methylation profile of SOCS-3 gene and its downstream effects in a BCR-ABL positive CML cells resistant to imatinib. Materials and Methods: BCR-ABL positive CML cells resistant to imatinib (K562-R) were developed by overexposure of K562 cell lines to the drug. Cytotoxicity was determined by MTS assays and $IC_{50}$ values calculated. Apoptosis assays were performed using annexin V-FITC binding assays and analyzed by flow cytometry. Methylation profiles were investigated using methylation specific PCR and sequencing analysis of SOCS-1 and SOCS-3 genes. Gene expression was assessed by quantitative real-time PCR, and protein expression and phosphorylation of STAT1, 2 and 3 were examined by Western blotting. Results: The $IC_{50}$ for imatinib on K562 was 362nM compared to 3,952nM for K562-R (p=0.001). Percentage of apoptotic cells in K562 increased upto 50% by increasing the concentration of imatinib, in contrast to only 20% in K562-R (p<0.001). A change from non-methylation of the SOCS-3 gene in K562 to complete methylation in K562-R was observed. Gene expression revealed down-regulation of both SOCS-1 and SOCS-3 genes in resistant cells. STAT3 was phosphorylated in K562-R but not K562. Conclusions: Development of cells resistant to imatinib is feasible by overexposure of the drug to the cells. Activation of STAT3 protein leads to uncontrolled cell proliferation in imatinib resistant BCR-ABL due to DNA methylation of the SOCS-3 gene. Thus SOCS-3 provides a suitable candidate for mechanisms underlying the development of imatinib resistant in CML patients.

• Molecules and Cells
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• v.39 no.12
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• pp.869-876
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• 2016

Cantharidin (CTD) is an active compound isolated from the traditional Chinese medicine blister beetle and displayed anticancer properties against various types of cancer cells. However, little is known about its effect on human chronic myeloid leukemia (CML) cells, including imatinib-resistant CML cells. The objective of this study was to investigate whether CTD could overcome imatinib resistance in imatinib-resistant CML cells and to explore the possible underlying mechanisms associated with the effect. Our results showed that CTD strongly inhibited the growth of both imatinib-sensitive and imatinib-resistant CML cells. CTD induced cell cycle arrest at mitotic phase and triggered DNA damage in CML cells. The ATM/ATR inhibitor CGK733 abrogated CTD-induced mitotic arrest but promoted the cytotoxic effects of CTD. In addition, we demonstrated that CTD downregulated the expression of the BCR-ABL protein and suppressed its downstream signal transduction. Real-time quantitative PCR revealed that CTD inhibited BCR-ABL at transcriptional level. Knockdown of BCR-ABL increased the cell-killing effects of CTD in K562 cells. These findings indicated that CTD overcomes imatinib resistance through depletion of BCR-ABL. Taken together, CTD is an important new candidate agent for CML therapy.

• Clinical and Experimental Pediatrics
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• v.54 no.3
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• pp.111-116
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• 2011

Childhood chronic myelogenous leukemia (CML) is a rare hematologic disease, with limited literature on the methods of treatment. Previously, allogeneic hematopoietic stem cell transplantation (HSCT) was considered the only curative treatment for this disease. Treatment with imatinib, a selective inhibitor of the BCR-ABL tyrosine kinase (TKI), has resulted in prolonged molecular response with limited drug toxicity. Imatinib is now implemented in the primary treatment regimen for children, but the paucity of evidence on its ability to result in permanent cure and the potential complications that may arise from long-term treatment with TKIs have prevented imatinib from superseding HSCT as the primary means of curative treatment in children. The results of allogeneic HSCT in children with CML are similar to those observed in adults; HSCT-related complications such as transplant-related mortality and graft-versus-host disease remain significant challenges. An overall consensus has been formed with regards to the need for HSCT in patients with imatinib resistance or those with advanced-phase disease. However, issues such as when to undertake HSCT in chronic-phase CML patients or how best to treat patients who have relapsed after HSCT are still controversial. The imatinib era calls for a reevaluation of the role of HSCT in the treatment of CML. Specific guidelines for the treatment of pediatric CML have not yet been formulated, underscoring the importance of prospective studies on issues such as duration of imatinib treatment, optimal timing of HSCT and the type of conditioning utilized, possible treatment pre-and post-HSCT, and the role of second-generation TKIs.

• CELLMED
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• v.13 no.12
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• pp.44.1-44.7
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• 2023

Objective: A case of reducing adverse effects associated with imatinib using Cyaplex F. Methods: The 52-year-old female with past medical history of stage 1 triple-positive breast cancer 10 years ago, and current metastatic melanoma has been complaining adverse effects after imatinib was started. Results: After OCNT was initiated, the patient's headache and muscle pain have been much tolerable and her AST/CPK levels were returned close to her baseline. Conclusion: OCNT may reduce side effects caused by Imatinib and help patient to stay with the current chemotherapy regimen.

• Development and Reproduction
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• v.21 no.2
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• pp.139-150
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• 2017

Metformin is the most commonly prescribed anti-diabetic drug with relatively minor side effect. Substantial evidence has suggested that metformin is associated with decreased cancer risk and anticancer activity against diverse cancer cells. The tyrosine kinase inhibitor imatinib has shown powerful activity for treatment of chronic myeloid leukemia and also induces growth arrest and apoptosis in colorectal cancer cells. In this study, we tested the combination of imatinib and metformin against HCT15 colorectal cancer cells for effects on cell viability, cell cycle and autophagy. Our data show that metformin synergistically enhances the imatinib cytotoxicity in HCT15 cells as indicated by combination and drug reduction indices. We also demonstrate that the combination causes synergistic down-regulation of pERK, cell cycle arrest in S and $G_2/M$ phases via reduction of cyclin B1 level. Moreover, the combination resulted in autophagy induction as revealed by increased acidic vesicular organelles and cleaved form of LC3-II. Inhibition of autophagic process by chloroquine led to decreased cell viability, suggesting that induction of autophagy seems to play a cell protective role that may act against anticancer effects. In conclusion, our present data suggest that metformin in combination with imatinib might be a promising therapeutic option in colorectal cancer.

• Tuberculosis and Respiratory Diseases
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• v.71 no.3
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• pp.210-215
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• 2011

Imatinib mesylate, a selective inhibitor of BCR-ABL kinase activity, has demonstrated significant clinical efficacy in the treatment of chronic myeloid leukemia (CML) and gastrointestinal stromal tumors (GISTs). It has become the standard of treatment for these diseases. Although the toxicity profile of imatinib is superior to that of interferon or other cytotoxic agents, some adverse events including edema, gastrointestinal toxicities and hematologic toxicities are commonly observed in the patients treated by imatinib. We present two cases of imatinib induced interstitial pneumonitis during the treatment of a chronic phase of CML.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2447-2451
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• 2013

Objective: To study changes of tumor associated carbohydrate antigen (TACAs) expression and mRNA levels for tumor associated glycosyltransferases, and assess subcellular localizations of N-acetyl galactosyltransferases (GalNAc-Ts) in the K562 leukemia cell line after imatinib treatment. Methods: RT-PCR was performed to analyze the expression of glycosyltransferases which synthesize O-glycan in tumor-associated carbohydrate antigens (TCTAs). The expression of Tn antigen, T antigen and sialyl T antigen on K562 cell membranes was measured by flow cytometry after treatment with different concentrations of imatinib. Co-localization of GalNAc-Ts and ER (endoplasmic reticulum) was determined by confocal laser scanning microcopy. Results: Transcript expression levels of several glycosyltransferases related to TCTAs were decreased after imatinib ($0-0.3{\mu}M$) treatment. Expression of Tn antigen and T antigen was increased while that of sialyl T antigen was decreased. Co-localization of GalNAc-Ts and ER was reduced by $0.2{\mu}M$ of imatinib. Conclusion: Imatinib inhibited the expression of O-glycan related TACAs and several related glycosyltransferases, while decreasing the co-localization of GalNAc-Ts and ER and normalizing O-glycosylation in the K562 human leukemia cell.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7555-7559
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• 2015

Background: CML includes 30% of all leukemias, and occurs from childhood to old age. The present study was a retrospective analysis of chronic phase CML patients registered to a Hematology Clinic in Kermanshah, Iran, with checking of treatment options. Materials and Methods: Between 2002 and 2014, 85 CML patients referred to our hematology clinic were enrolled in our study. We surveyed age, sex, B-symptoms, splenomegaly, Sokal score, Hasford score, treatment and survival in all patients. Philadelphia chromosome analysis was conducted for each patient by conventional cytogenetics. We compared treatment in the patients with three drugs, imatinib, hydroxyurea (HU) and interferon alpha (IFN-${\alpha}$). Results: The mean age of the patients at diagnosis was $47.5{\pm}14.5years$ (range, 23-82 years), with 43 (50.6%) being male. Some 13 (15.3%) were referred to our clinic for the first time with B-symptoms and 44 patients (51.8%) had splenomegaly. The Sokal score for 77 (90.6%) was low, 4 (4.7%) was intermediate and 4(4.7%) was high, but Hasford (Euro) scores for all patients were low. The 5-year survival rate for treated patients with imatinib, imatinib plus HU and imatinib plus HU plus IFN-${\alpha}$ was 90.5%, 81.1% and 55.6%, respectively Conclusions: The results show that imatinib therapy alone provides better survival in CML patients compared to HU or IFN-${\alpha}$. Combinations of IFN-${\alpha}$ and/or HU with imatinib probably reduce survival.