ABSTRACT
The immunosuppressive nature of the tumor microenvironment is a critical problem that should be considered before the design of immunotherapies. Interleukin (IL)-6 and its related downstream molecules such as signal transducer and activator of transcription (STAT)3 play an important role in the cancer progression, which can be considered as potential therapeutic targets. In the present study, we generated the active-targeted hyaluronate (HA) recoated N, N, N-trimethyl chitosan (TMC) nanoparticles (NPs) to deliver IL-6- and STAT3-specific small interfering RNAs (siRNAs) to the CD44-expressing cancer cells. We utilized the interaction between HA and CD44 to increase the specificity and efficacy of cellular uptake in NPs. The results showed that the synthesized NPs had efficient physicochemical characteristics, high transfection efficiency, low toxicity, and controlled siRNA release. siRNA-loaded NPs significantly inhibited the IL-6/STAT3 expression, which was associated with blockade of proliferation, colony formation, migration, and angiogenesis in cancer cells. These findings imply the potential of HA-TMC NPs as potent vectors in gene therapy and their application for the silencing of IL-6 and STAT3, as a novel anti-cancer combination therapeutic strategy, for the first time.
Subject(s)
Breast Neoplasms/therapy , Chitosan/chemistry , Interleukin-6/genetics , Neovascularization, Pathologic/therapy , STAT3 Transcription Factor/genetics , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Proliferation/drug effects , Cell Survival/drug effects , Chitosan/pharmacology , Female , Gene Expression Regulation, Neoplastic/drug effects , Humans , Hyaluronan Receptors/genetics , Hyaluronic Acid/chemistry , Interleukin-6/antagonists & inhibitors , Nanoparticles/chemistry , Neovascularization, Pathologic/genetics , Neovascularization, Pathologic/pathology , RNA, Small Interfering/chemistry , RNA, Small Interfering/genetics , RNA, Small Interfering/pharmacology , STAT3 Transcription Factor/antagonists & inhibitors , Tumor Microenvironment/drug effectsABSTRACT
Introduction: Chronic myelogenous leukemia (CML) is a myeloproliferative disorder caused by the Philadelphia chromosome translocation, at (9; 22), which results in BCR-ABL fusion tyrosine kinase oncoprotein. This fusion induces down-regulation of miR-155. Upregulation of miR-155 can influence cell fate via the effect on p27kip1 and apoptosis. The aim of this study was to induce apoptosis in K562 CML cell line by overexpression of miR-155. Methods: The K562 cell line was transfected with pLenti-III-pre mir155-GFP constructs through electroporation. Then, overexpression of miR-155 as well as the expression level of p27kip1 and c-Myc was analyzed by quantitative PCR (qPCR). The level of p27 (Kip1) protein expression was measured by Western blot and the Annexin V method was carried out to investigate apoptosis. Results: Flow cytometric analysis results of K562 cells transfected with pLenti-III-pre mir155-GFP construct showed a significant increase in cell apoptosis. Gene expression and protein level of p27kip1 were upregulated. However, there was no change in c-Myc expression profile. Conclusion: miR-155 could be a promising approach to aid in the treatment of CML. However, further studies are required in this respect.
