PubMed | Chest Hospital of Linyi Linyi and Peoples Hospital of Linyi Linyi
Type: Journal Article | Journal: International journal of clinical and experimental medicine | Year: 2016
Slug is an E-cadherin repressor and a suppressor of PUMA (p53 upregulated modulator of apoptosis) and it has recently been demonstrated that Slug plays an important role in controlling apoptosis. In this study, we examined whether Slugs ability to silence expression suppresses the growth of leukemia HL-60 cells and/or sensitizes leukemia HL-60 cells to adriamycin (ADR) through induction of apoptosis.SLUG siRNA was transfected into the HL-60 and HL-60(ADR) cell lines (an adriamycin resistant cell line). The stably SLUG siRNA transfected HL-60 and HL-60(ADR) cells was transiently transfected with PUMA siRNA. The mRNA and protein expression of SLUG and PUMA were determined by Quantitative real-time RT-PCR and Western blot assay. The effects of SLUG siRNA alone or combined with ADR or PUMA siRNA on growth and apoptosis in HL-60 and HL-60(ADR) cells was detected by MTT, ELISA and terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay.The results showed that SLUG was less expressed in the HL-60 cells, and high expressed in the HL-60(ADR) cells. Obvious down-regulation of SLUG mRNA and protein levels and up-regulation of PUMA mRNA and protein levels after SLUG siRNA transfection was showed in the HL-60(ADR) cells. Treatment with ADR induced SLUG mRNA and protein in the HL-60 cells. Significant positive correlation was observed between basal SLUG mRNA and protein and ADR sensitivity. SLUG gene silencing by SLUG siRNA transfection inhibited growth and induced apoptosis, and increased ADR killing of the HL-60 and HL-60(ADR) cell lines. After the SLUG siRNA transfected HL-60 and HL-60(ADR) cells was transiently transfected with PUMA siRNA, did not increase ADR killing of the HL-60 and HL-60(ADR) cell lines.SLUG level positively correlated with sensitivity to ADR. SLUG siRNA could effectively reduce SLUG expression and induce PUMA expression and restore the drug sensitivity of resistant leukemic cells to conventional chemotherapeutic agents.
PubMed | Guangdong Medical College, Southern Medical University, Linyi Blood Center Linyi and Peoples Hospital of Linyi Linyi
Type: Journal Article | Journal: International journal of clinical and experimental medicine | Year: 2015
The major surface lipoglycan of Mycobacterium tuberculosis (M. tb), mannose-capped lipoarabinomannan (ManLAM), is an immunosuppressive epitope of M. tb. Interleukin (IL)-37, is a newly identified anti-inflammatory cytokine, which reduces systemic and local inflammation. However, the correlation between ManLAM and IL-37 remains unknown. Therefore, in this study, we investigate the possible role and relative molecular mechanism of ManLAM in IL-37 production of human type II alveolar epithelial cells by using A549 cell line. Here, we report that M. tb induced IL-37 mRNA and protein expression in a time-dependent manner. We next fractionated components of M. tb using chloroform: methanol (C:M) and water. In sharp contrast to the C:M phase, water phase was mainly responsible for the production of IL-37. Since ManLAM is the major component of water phase, we found that ManLAM induced IL-37 mRNA and protein expression in a time and dose-dependent manner, while this activity was almost totally abolished by the ERK1/2 (U0126) and p38 (SB203580) inhibitor. ManLAM stimulation significantly induced ERK1/2 and p38 phosphorylation in A549 cells, as well as cell surface TLR2 expression. After interfering TLR2 expression, ERK1/2 and p38 phosphorylation levels were markedly decreased, and also IL-37 production. Though ManLAM also promoted TLR4 expression on A549 cells, TLR4 interference showed no influence on ManLAM-induced IL-37 production. Our results indicate that ManLAM induces IL-37 production in human type II alveolar epithelial cells via up-regulating TLR2/p38 or ERK1/2 pathway, and this provide an important evidence to explain the pathological role of ManLAM that contribute to the persistence of M. tb.