PubMed | Peoples Hospital of Zhangqiu Jinan, Peoples Hospital of Laiwu Laiwu and Qingdao Women and Childrens Hospital Qingdao
Type: Journal Article | Journal: International journal of clinical and experimental medicine | Year: 2016
Up-regulation of clusterin is associated with the survival and progression of various malignancies, and down-regulation of clusterin promotes apoptosis and inhibits invasion. The aim of this study was to explore the effect of clusterin small interference RNA (siRNA) on the proliferation, apoptosis and invasion of HL-60 acute myeloid leukemia (AML) cells.siRNA transfection was performed using Lipofectamine2000 reagent. Relative protein expressions were quantified by Western blot. Trypan blue assay was performed to assess tumor cell proliferation after siRNA transfection. The cytotoxic effect of clusterin siRNA on leukemic cells was measured using MTT assay. Apoptosis was detected using fluorescence microscopy assay. Migration and invasion was detected after clusterin was silenced.Clusterin siRNA clearly lowered clusterin protein levels in a time- dependent manner, leading to marked inhibition of cell survival, proliferation and invasion. Furthermore, clusterin down-regulation significantly enhanced the extent of HL-60 apoptotic cells.Our results suggest that the down-regulation of clusterin by siRNA can effectively trigger apoptosis and inhibit the proliferation and invasion of leukemic cells. Therefore, clusterin siRNA may be a potent adjuvant in AML therapy.
PubMed | Peoples Hospital of Weifang Weifang, Peoples Hospital of Zhangqiu Jinan and Peoples Hospital of Laiwu Laiwu
Type: Journal Article | Journal: International journal of clinical and experimental medicine | Year: 2015
Clusterin (CLU) is known as a multifunctional protein involved in a variety of physiological processes including lipid transport, epithelial cell differentiation, tumorigenesis, and apoptosis. Our recent study has demonstrated that knockdown of clusterin sensitizes pancreatic cancer cell lines to gmcitabine treatment. However the details of this survival mechanism remain undefined. Of the various downstream targets of CLU, we examined activation of the NF-kB transcription factor and subsequent transcriptional regulation of BCL-2 gene in pancreatic cancer cell MIA-PaCa-2. The MIA-PaCa-2 cells were transfected with an antisense oligonucleotide (ASO) against clusterin, which led to a decreased protein level of the antiapoptotic gene BCL-2. Furthermore, inhibition of CLU decreased the function of NF-kB, which is capable of transcriptional regulation of the BCL-2 gene. Inhibiting this pathway increased the apoptotic effect of gmcitabine chemotherapy. Re-activated NF-kB resulted in attenuation of ASO-induced effects, followed by the bcl-2 upregulation, and bcl-2 re-inhibition resulted in attenuation of Re-activated NF-kB -induced effects. Animals injected with ASO CLU in MIA-PaCa-2 cells combined with gmcitabine treatment had fewer tumors than gmcitabine or ASO CLU alone. These findings suggest that knockdown of CLU sensitized MIA-PaCa-2 cells to gmcitabine chemotherapy through modulating NF-Kb/bcl-2 pathway.