Inhibition of Nrf2 promotes the antitumor effect of Pinelliae rhizome in papillary thyroid cancer

We previously reported that Xiaotan Sanjie (XTSJ) decoction can prevent the progression of gastric cancer in vitro and in vivo. Pinelliae rhizome (PR), one component of XTSJ decoction, has an inhibitory effect on the growth and proliferation of tumor cells. The present study investigated the underlying mechanisms of action of PR. Using the human papillary thyroid cancer cell lines, TPC-1 and BCPAP, we found that XTSJ decoction and PR alone decreased cell viability to a similar extent in both cell lines, whereas treatment with XTJS decoction without PR [PR (−)] had a lesser effect. PR treatment inhibited the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) in a dose-dependent manner. To investigate the role of Nrf2 in the PR-mediated effects of XTSJ, knockdown of Nrf2 in the tumor cell lines using Nrf2 siRNA (siNrf2) was performed and transfected cells were treated with PR. Silencing of Nrf2 amplified the effects on autophagy, cell viability, apoptosis, and colony formation. Similar results were obtained following treatment with the autophagy inhibitor 3-methyladenine (3-MA). Furthermore, treatment with PR, siNrf2, and/or 3-MA inhibited the MAPK pathway, and analysis of the MAPK pathway components confirmed the role of this pathway in the PR-mediated cellular effects. In mice implanted with siNrf2-transfected cells, the effects of PR were amplified. Taken together, these findings indicate that PR is critical for the inhibitory effects of XTSJ decoction on tumor cell viability and that downregulation of Nrf2 promotes the antitumor effects of PR on papillary thyroid cancer cells.     

Long noncoding RNA FOXD3-AS1 promotes colon adenocarcinoma progression and functions as a competing endogenous RNA to regulate SIRT1 by sponging miR-135a-5p

More and more documents have proved that the abnormal expression of long noncoding RNAs (lncRNAs) are correlated with the initiation and progression of colorectal cancer (CRC). lncRNA FOXD3-AS1 has been reported in glioma for its oncogenic property. According to the survival analysis of The Cancer Genome Atlas database, FOXD3-AS1 upregulation implied lower survival rate of patients with CRC. Quantitative real-time polymerase chain reaction showed the overexpression of FOXD3-AS1 in both CRC tissues and cells. The Kaplan–Meier method demonstrated the prognostic value of FOXD3-AS1 for patients with CRC. To explore the effect of FOXD3-AS1 on CRC progression, loss-of-function experiments were carried out, whose results indicated that knockdown of FOXD3-AS1 suppressed cell proliferation, migration, and invasion, inhibited cell cycle and promoted cell apoptosis in vitro. In vivo experiments affirmed that FOXD3-AS1 affected tumor growth. FOXD3-AS1 expression was enriched in the cytoplasm of CRC cells. Mechanism experiments revealed that FOXD3-AS1 served as a competing endogenous RNA to upregulate SIRT1 by sponging miR-135a-5p. In addition, SIRT1 silencing also restrained cell proliferation and motility. Rescue assays revealed the biological function of FOXD3-AS1/miR-135a-5p/SIRT1 axis in CRC progression. In conclusion, FOXD3-AS1 promotes CRC progression by regulating miR-135a-5p/SIRT1 axis, shedding lights on the way to CRC treatments.     

A single nuclear polymorphism in let-7g binding site affects the doubling time of thyroid nodule by regulating KRAS-induced cell proliferation

As an indicator for the malignancy of thyroid nodules (TN), the doubling time of TN was studied in this study to evaluate the effect of rs712 polymorphism on the progression of TN. In addition, we aimed to study the potential molecular mechanisms underlying the pathological effect of rs712 polymorphism upon TN. A Taqman method was used to genotype the patients according to their rs712 polymorphism. Real-time polymerase chain reaction, western blot, Terminal deoxynucleotidyl transferase dUTP nick end labeling assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay was conducted to study the correlation between KRAS expression and the pathological effect of rs712 polymorphism. In-silicon analysis and luciferase assay were utilized to establish the regulatory relationship between let-7g and KRAS. KRAS messenger RNA (mRNA)/protein levels in the GG group were upregulated with a decreased apoptosis index. KRAS mRNA was validated to be a virtual target of let-7g. In addition, the mRNA/protein level of KRAS as well as cell proliferation index was decreased in primary thyroid cancer cells genotyped as TT/TG and transfected with KRAS small interfering RNA (siRNA)/let-7g precursors. The cell apoptosis index was evidently elevated in the KRAS siRNA/let-7g precursors group compared with that in the scramble controls. Moreover, KRAS mRNA/protein only showed slight reduction when GG-genotyped primary thyroid cancer cells were transfected by let-7g precursors. Additionally, let-7g precursors exhibited no significant effect on cell proliferation index or cell apoptosis in GG cells. Rs712 polymorphism T>G in the 3′-untranslated region of KRAS interrupts the interactions between let-7g and KRAS mRNA, leading to a higher cell proliferation index and reduced doubling time of TN.     

AZGP1 is androgen responsive and involved in AR-induced prostate cancer cell proliferation and metastasis

Alpha-2-glycoprotein 1, zinc-binding (AZGP1), known as zinc-alpha-2-glycoprotein (ZAG), is a multifunctional secretory glycoprotein and relevant to cancer metastasis. Little is known regarding the underlying mechanisms of AZGP1 in prostate cancer (PCa). In the present study, we report that AZGP1 is an androgen-responsive gene, which is involved in AR-induced PCa cell proliferation and metastasis. In clinical specimens, the expression of AZGP1 in PCa tissues is markedly higher than that in adjacent normal tissues. In cultures, expression of AZGP1 is upregulated by the androgen-AR axis at both messenger RNA and protein levels. Furthermore, Chip-Seq assay identifies canonical androgen-responsive elements (AREs) at AZGP1 enhancer; and dual-luciferase reporter assays reveal that the AREs is highly responsive to androgen whereas mutations of the AREs abolish the reporter activity. In addition, AZGP1 promotes G1/S phase transition and cell cycle progress by increasing cyclin D1 levels in PCa cells. Functional studies demonstrate that knocking down endogenous AZGP1 expression in LNCaP and CWR22Rv1 cells largely weaken androgen/AR axis-induced cell migration and invasion. In vivo xenotransplantation tumor experiments also show that AZGP1 involves in androgen/AR axis-mediated PCa cell proliferation. Taken together, our study implicates for the first time that AZGP1 is an AR target gene and is involved in androgen/AR axis-mediated cell proliferation and metastasis in primary PCa.     

Lipopolysaccharide-induced proliferation and glycolysis in airway smooth muscle cells via activation of Drp1

Abnormal airway smooth muscle cells (ASMCs) proliferation is an important pathological process in airway remodeling contributes to increased mortality in asthma. Mitochondrial dynamics and metabolism have a central role in the maintenance of the cell function. In this study, lipopolysaccharide (LPS)-induced ASMCs proliferative model was used to investigate the effect of mitochondria on the proliferation of ASMCs and the possible mechanism. We used cell and molecular biology to determine the effect of dynamin-related protein 1 (Drp1) on LPS-mediated ASMCs cell cycle progression and glycolysis. The major findings of the current study are as follows: LPS promoted an increased mitochondrial fission and phosphorylation of Drp1 at Ser616 (p-Drp1 Ser616). LPS-induced ASMCs proliferation and cell cycle progression, which was significantly inhibited application of Drp1 RNA interfering. Glycolysis inhibitor 2-deoxyglucose (2-DG) depressed ASMCs proliferative process induced by LPS stimulation. LPS caused mitochondrial metabolism disorders and aerobic glycolysis in a dependent on Drp1 activation. These results indicated that Drp1 may function as a key factor in asthma airway remodeling by mediating ASMC proliferation and cell cycle acceleration through an effect on mitochondrial metabolic disturbance.     

HDAC3 inhibition disrupts the assembly of meiotic apparatus during porcine oocyte maturation

Histone deacetylases (HDACs) are involved in a wide array of biological processes. However, the role of HDAC3 in porcine oocytes remains unclear. In the current study, we examine the effects of HDAC3 inhibition on porcine oocyte maturation using RGFP966, a selective HDAC3 inhibitor. We find that suppression of HDAC3 activity prevents not only the expansion of cumulus cells but also the meiotic progression of oocytes. It is interesting to note that HDAC3 displays a spindle-like distribution pattern as the porcine oocytes enter meiosis. In line with this, confocal microscopy reveals the high frequency of spindle defects and chromosomal congression failure in metaphase oocytes exposed to RGFP966. Moreover, HDAC3 inhibition results in the hyperacetylation of α-tubulin during oocyte meiosis. These findings indicate that HDAC3 activity might control the microtubule stability via the deacetylation of tubulin, which is critical for maintaining the proper spindle assembly, accurate chromosome separation, and orderly meiotic progression during porcine oocyte maturation.     

microRNA-448 inhibits stemness maintenance and self-renewal of hepatocellular carcinoma stem cells through the MAGEA6-mediated AMPK signaling pathway

Hepatocellular carcinoma (HCC) occurs mainly in patients with chronic liver disease and cirrhosis. Increasing evidence has identified the involvement of microRNAs (miRNAs) acting as essential regulators in the progression of HCC. As predicted by microarray analysis, miR-448 might potentially affect HCC progression by regulating the melanoma-associated antigen (MAGEA). Therefore, the present investigation focused on exploring whether or not miR-448 and MAGEA6 were involved in the self-renewal and stemness maintenance of HCC stem cells. The interaction among miR-448, MAGEA6, and the AMPK signaling pathway was evaluated. It was noted that miR-448 targeted and downregulated MAGEA6, thus activating the AMP-activated protein kinase (AMPK) signaling pathway in HCC. Furthermore, for the purpose of exploring the functional relevance of MAGEA6 and miR-448 on the sphere formation, colony formation, and invasion and migration of HCC stem cells, the CD133⁺CD44 ⁺ HCC stem cells were sorted and treated with the mimic or inhibitor of miR-448, small interfering RNA (siRNA) against MAGEA6 or an AMPK activator AICAR. MAGEA6 silencing or miR-448 overexpression was demonstrated to inhibit the abilities of sphere formation, colony formation, cell migration, and invasion of HCC cells. Afterwards, a rescue experiment was conducted and revealed that MAGEA6 silencing reversed the effects of miR-448 inhibitor on stemness maintenance and self-renewal of HCC stem cells. Finally, after the in vivo experiment was carried out, miR-448 was observed to restrain the tumor formation and stemness in vivo. Altogether, miR-448 activates the AMPK signaling pathway by downregulating MAGEA6, thus inhibiting the stemness maintenance and self-renewal of HCC stem cells, which identifies miR-448 as a new therapeutic strategy for HCC.     

Irisin attenuates oxidized low-density lipoprotein impaired angiogenesis through AKT/mTOR/S6K1/Nrf2 pathway

It is known that irisin increases total body energy expenditure, decreases body weight, and enhances insulin sensitivity. Although previous studies have demonstrated that irisin induces vascular endothelial cell (EC) angiogenesis, the molecular mechanisms underlying irisin-induced angiogenesis under conditions reflecting atherosclerosis are not known. The aim of the present study is to investigate whether irisin could inhibit oxidized low-density lipoprotein (oxLDL) impaired angiogenesis. We investigated the effect of irisin on angiogenesis in vitro by evaluating cell viability, cell migration, and the capacity to form capillary-like tubes using human umbilical vein endothelial cells and human microvascular endothelial cells (HUVECs and HMEC-1) that were treated with oxLDL. We also evaluated the effects of irisin on angiogenesis in vivo by Matrigel plug angiogenesis assay and in a chicken embryo membrane (CAM) model. Our results demonstrated that irisin increased oxLDL-treated EC viability as well as migration and tube formation. Moreover, oxLDL inhibited angiogenic response in vivo, both in the Matrigel plug angiogenesis assay and in the CAM model, and was attenuated by irisin. Furthermore, irisin decreased apoptosis, inflammatory cytokines, and intracellular reactive oxygen species (ROS) levels in oxLDL-treated EC. In addition, we found that irisin upregulated pAkt/mTOR/Nrf2 in oxLDL-treated EC. Both mTOR/Nrf2 shRNA and LY294002 could inhibit the protective effect of irisin. Taken together these results, they suggested that irisin attenuates oxLDL-induced vascular injury by activating the Akt/mTOR/Nrf2 pathway. Our findings suggest that irisin attenuates oxLDL-induced blood vessel injury.