BCR-ABL oncoprotein stimulates cell proliferation and inhibits apoptosis in chronic myeloid leukemia (CML). For cure, imatinib is a widely used tyrosine kinase inhibitor, but developing chemotherapeutic resistance has to be overcome. In this study, we aimed to determine differing genome-wide microRNA (miRNA) and messenger RNA (mRNA) expression profiles in imatinib resistant (K562/IMA-3 μM) and parental cells by targeting STAT5A via small interfering RNA (siRNA) applications. After determining possible therapeutic miRNAs, we aimed to check their effects upon cell viability and proliferation, apoptosis, and find a possible miRNA::mRNA interaction to discover the molecular basis of imatinib resistance. We detected that miR-2278 and miR-1245b-3p were most significantly regulated miRNAs according to miRNome array. Upregulating miR-2278 expression resulted in the inhibition of resistant leukemic cell proliferation and induced apoptosis, whereas miR1245b-3p did not exhibit therapeutic results. Functional analyses indicated that AKT2, STAM2, and STAT5A mRNAs were functional targets for miR-2278 as mimic transfection decreased their expressions both at transcriptional and translational level, thus highlighting miR-2278 as a tumor suppressor. This study provides new insights in discovering the mechanism of imatinib resistance due to upregulating the tumorsuppressor hsa-miR-2278 which stands for a functional therapeutic approach, inhibited leukemic cell proliferation, induced apoptosis, and regain of chemotherapeutic drug response in CML therapy.

The objective of the study was to investigate the cytotoxic and apoptotic effects of Methotrexate (MTX)-loaded chitosan (CS) on LNCaP prostate cancer cell line in vitro. For this purpose, CS nanoparticles (NPs) were synthesized through ionic gelation method and MTX was loaded into the carrier with encapsulation. SEM images of the CS NPs have revealed that they have size of about 85 nm in mono-disperse manner. Drug loading yield was found to be 95.7 % with 470 μg drug/mg NP loading capacity. In vitro drug release study showed that MTX was released in a controlled manner. Cell viability was detected by using trypan blue dye exclusion test and WST-1 cell proliferation assay was performed to show cytotoxic effects of the CS, the MTX and the MTX-loaded NP. IC50 values of CS, MTX and MTX-loaded NPs were assigned from the cell survival plot and were determined as 67.18 μM, 20.21 μM and 2.94 μM at the 72nd hour, respectively. As for apoptosis analysis results, following to MTX-loaded CS treatment of LNCAP cells, apoptotic cell percent was detected as 39.3 % at the 72nd hour, that is, MTX-loaded CS induces 1.85-fold increase in apoptotic cell percent in comparison with that of MTX- induced apoptosis.

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Background: Dysregulation of the cell cycle is one of the main causes of melanomagenesis. Genome-wide studies showed that expression of Aurora -A and -B significantly has been upregulated in melanoma. However, there is no FDA approved drug targeting aurora kinases in the treatment of melanoma. In addition, the development of resistance to chemotherapeutic agents in the treatment of melanoma and, as a result, the relapse due to heterogeneous cell groups in patients is a second phenomenon that causes treatment failure. Therefore, there is an urgent need for therapeutic alternatives targeting both melanoma and melanoma cancer stem cells (MCSCs) in treatments. At this stage, cell cycle regulators become promising targets. Objective: In this study, we aimed to identify the effects of Aurora kinase inhibitor CCT137690 on the cytotoxicity, apoptosis, cell cycle, migration, and colony formation and expression changes of genes related to proliferation, cell death and cell cycle in melanoma and melanoma cancer stem cell. In addition, we investigated the apoptotic and cytostatic effects of CCT137690 in normal fibroblast cells. Methods: We evaluated the cytotoxic effect of CCT137690 in MCSCs, NM2C5 referring as melanoma model cells and WI38 cells by using the WST-1 test. The effect of CCT137690 on apoptosis was detected via Annexin V and JC-1 method; on cell cycle progression by cell cycle test; on gene expression by using RT-PCR, on migration activity by wound healing assay and clonal growth by clonogenic assay in NM2C5 cells and MCSCs. The effects of CCT137690 in WI-38, referring as healthy fibroblast cell, were assessed through Annexin V and cell cycle method. Results: CCT137690 was determined to have a cytotoxic and apoptotic effect in MCSCs and melanoma. It caused polyploidy and cell cycle arrest at the G2/M phase in MCSCs and melanoma cells. The significant decrease in the expression of MMP2, MMP7, MMP10, CCNB1, IRAK1, PLK2 genes, and the increase in the expression of PTEN, CASP7, p53 genes were detected. Conclusion: Aurora kinases inhibitor CCT137690 displays promising anticancer activity in melanoma and especially melanoma cancer stem cells. The effect of CCT137690 on melanoma and MCSC may provide a new approach to treatment protocols.

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