Smad4 regulates TGF-ß1-mediated hedgehog activation to promote epithelial-to-mesenchymal transition in pancreatic cancer cells by suppressing Gli1 activity.

Pancreatic cancer (PC) is an aggressive and metastatic gastrointestinal tumor with a poor prognosis. Persistent activation of the TGF-ß/Smad signaling induces PC cell (PCC) invasion and infiltration via epithelial-to-mesenchymal transition (EMT). Hedgehog signaling is a crucial pathway for the development of PC via the transcription factors Gli1/2/3. This study aimed to investigate the underlying molecular mechanisms of action of hedgehog activation in TGF-ß1-triggered EMT in PCCs (PANC-1 and BxPc-3). In addition, overexpression and shRNA techniques were used to evaluate the role of Smad4 in TGF-ß1-treated PCCs. Our data showed that TGF-ß1 promoted PCC invasion and infiltration via Smad2/3-dependent EMT. Hedgehog-Gli signaling axis in PCCs was activated upon TGF-ß1 stimulation. Inhibition of hedgehog with cyclopamine effectively antagonized TGF-ß1-induced EMT, thereby suggesting that the hedgehog signaling may act as a downstream cascade signaling of TGF-ß1. As a key protein that assists the nuclear translocation of Smad2/3, Smad4 was highly expressed in PANC-1 cells, but not in BxPc-3 cells. Conversely, Gli1 expression was low in PANC-1 cells, but high in BxPc-3 cells. Furthermore, knockdown of Smad4 in PANC-1 cells by shRNA inhibited TGF-ß1-mediated EMT and collagen deposition. Overexpression of Smad4 did not affect TGF-ß1-mediated EMT due to the lack of significant increase in nuclear expression of Smad4. Importantly, Gli1 activity was upregulated by Smad4 knockdown in PANC-1 cells and downregulated by Smad4 overexpression in BxPc-3 cells, indicating that Gli1 may be a negative target protein downstream of Smad4. Thus, Smad4 regulates TGF-ß1-mediated hedgehog activation to promote EMT in PCCs by suppressing Gli1 activity.

Targeted inhibition of mTOR by BML-275 induces mitochondrial-mediated apoptosis and autophagy in prostate cancer.

Prostate cancer (PCa) is the most frequently diagnosed cancer among men and the second leading cause of death in Western countries. Clinically, screening drugs and develop developing new therapeutics to treat PCa is of great significance. In this study, BML-275 was demonstrated to exert potent antitumor effects in PCa by antagonizing mTOR activity. In cultured PCa cells, BML-275 treatment reduced the expression levels of c-Myc and survivin, promoted the activation of p53, and thereby induced p21/cyclin D1/CDK4/6-dependent cell cycle G1/S arrest. As a result, BML-275 inhibited cellular proliferation and induced mitochondrial-mediated apoptosis. In addition, BML-275 treatment triggered autophagy. Interestingly, EACC-mediated suppression of autophagy did not affect BML-275-induced proliferation and apoptosis. Nude mouse tumorigenic experiments also confirmed that BML-275 inhibited PCa growth, induced PCa cell apoptosis and autophagy. Mechanistically, the activities of PI3K/AKT and AMPK pathways were downregulated by BML-275 treatment in vitro and in vivo. Importantly, mTOR, a common downstream negative protein of PI3K/AKT and AMPK signaling, was induced to inactivate, which may be associated with the induction of apoptosis and autophagy. The pharmacological activation of mTOR by MHY1485 abolished the induction of apoptosis and autophagy of BML-275. Molecular docking results showed that BML-275 can bind to the FKRP12-rapamycin binding site on mTOR protein, and thereby may have the same inhibitory activity on mTOR as rapamycin. Thus, these findings indicated that BML-275 induces mitochondrial-mediated apoptosis and autophagy in PCa by targeting mTOR inhibition. BML-275 may be a potential candidate for the treatment of PCa.

P3H4 is correlated with clinicopathological features and prognosis in bladder cancer.

BACKGROUND: Genetic alterations play a significant role in the progression of bladder cancer. Identifying novel biomarkers to personalize the therapeutic regimen and evaluate the prognosis of patients with bladder cancer is vital. Prolyl 3-hydroxylase family member 4 (P3H4) is significantly involved in several types of human cancer. However, the effect of P3H4 in bladder cancer remains unknown. METHODS: The mRNA expression of P3H4 was measured in 44 paired tumors and adjacent normal tissues by using real-time reverse transcription-polymerase chain reaction. RNA-Seq data of 389 patients with bladder cancer were downloaded to investigate the effect of P3H4 on bladder cancer from The Cancer Genome Atlas (TCGA) project. RESULTS: P3H4 was overexpressed in bladder cancer compared with the adjacent normal tissue both in our tissue samples and TCGA samples. The mRNA expression of P3H4 was significantly related to several clinicopathological factors of bladder cancer, including age, race category, histologic grade, tumor histologic subtype, and AJCC stage. The high P3H4 expression group had a shorter overall survival (OS) than the low P3H4 expression group. Univariate Cox regression analysis showed that age, angiolymphatic invasion, lymph node metastasis, tumor histologic subtype, metastasis, AJCC stage, and P3H4 were significantly related to OS. Moreover, multivariate Cox analysis revealed that P3H4, as well as age and AJCC stage, was an independent predictor of poor OS. CONCLUSION: Given its tumorigenic role, P3H4 may serve as a promising tumor-promoting gene in bladder cancer.

Hyperoside protects human kidney­2 cells against oxidative damage induced by oxalic acid.

The majority of renal calculi (kidney stones) are calcium stones. Oxidative damage to renal tubular epithelial cells induced by reactive oxygen species (ROS) is the predominant cause of calcium oxalate stone formation. Hyperoside (Hyp) is a flavonol glycoside extracted from medicinal plants and appears to exhibit potent antioxidant activity in various cells. The aim of the present study was to investigate the protective effect of Hyp on renal cells exposed to oxidative stress simulated by oxalic acid (OA), and to determine whether the underlying mechanism involves the nuclear factor E2­related factor2 (Nrf2)­antioxidative response element signaling pathway. The study determined the indicators of high oxidative stress, including ROS and hydrogen peroxide (H2O2) in human kidney­2 cells and the results demonstrated that the levels of ROS, as evaluated by flow cytometry, and H2O2 were significantly increased following treatment with OA (5 mmol/l) for 24 h (OA group), compared with those in the untreated control group. The increased activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in these cells explained this observation, as it is a major source of ROS. The results demonstrated that, in the OA group, the adhesion of calcium oxalate crystals and lactate dehydrogenase (LDH) were significantly increased, and MTT assay demonstrated that cell viability was inhibited, compared with the control, which indicated that severe injury of cells was induced by OA. However, when the cells were pre­treated with Hyp prior to treatment with OA (drug group), the levels of ROS and H2O2, and the activities of NADPH oxidase and LD were increased, and the adhesion of calcium oxalate crystals to cells was reduced, compared with the OA group. Western blot analysis and reverse transcription­quantitative polymerase chain reaction demonstrated that the protein and mRNA expression levels of Nrf2, heme oxygenase­1 (HO­1) and NAD(P)H: quinineoxidoreductase 1 (NQO1) in the Hyp groups were significantly increased, compared with those in the OA group, with the exception of Nrf2 mRNA. These results suggested that Hyp had a marked protective effect on renal cells against the oxidative damage and cytotoxicity simulated by OA. This is the first report, to the best of our knowledge, demonstrating that the ability of Hyp to enhance the endogenous functions of antioxidation and detoxification in cells may involve the Nrf2/HO­1/NQO1 pathway.

Study on the autophagy of prostate cancer PC-3 cells induced by oridonin.

To investigate the mechanism of oridonin (ORI)-induced autophagy in prostate cancer PC-3 cells, PC-3 cells cultured in vitro were treated with ORI, and the inhibitory ratio of ORI on PC-3 cells was assayed by 3-4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide. The ultrastructural changes of the cells were observed under light microscope, scanning electron microscope (SEM), and transmission electron microscope (TEM). Acridine orange (AO) staining was used to observe the acidic vesicular organelles (AVOs). The level of autophagy-related proteins, MAP1-LC3, was detected by Western Blot, and RT-PCR was used to detect the level of mRNA of beclin 1. After ORI treatment, the proliferation of PC-3 cells was inhibited significantly in a concentration and time-dependent manner. SEM examination revealed cellular shrinkage and disappearance of surface microvilli in ORI-treated cells. Under TEM examination, the nuclei exhibited chromatin condensation and the appearance of a large number of autophagosomes with double-membrane structure in cytoplasm. AO staining showed the existence of AVOs. The expression of LC3 and the mRNA level of beclin 1 was increased by ORI. Furthermore, autophagy inhibitor 3-methyladenine reversed the increase of beclin 1 mRNA. The growth of PC-3 cells was inhibited, and autophagy was induced by ORI, indicating ORI may have a potential antitumor effect.

[Autophagy of prostate cancer PC-3 cells under the induction of oridonin].

OBJECTIVE: To investigate the mechanism of oridonin (ORI)-induced autophagy in prostate cancer PC-3 cells. METHODS: The PC-3 cells cultured in vitro were treated with ORI. The inhibitory ratio of oridonin In PC-3 cells was assayed by MTT. The ultrastructural cellular changes were observed under light microscope, scanning electron microscope (SEM) and transmission electron microscope (TEM). AO staining was used to observe the acidic vesicular organelles (AVOs). The level of MAP1-LC3 was detected by Western blot and reverse transcriptase polymerase chain reaction (RT-PCR) used to detect the level of mRNA of beclin 1. RESULTS: After oridonin treatment, the proliferation of PC-3 cells was inhibited significantly in a concentration and time-dependent manner. The SEM examination revealed cellular shrinkage and the disappearance of surface microvilli after ORI treatment. And on the TEM examination, the nuclei exhibited chromatin condensation and the appearance of a large number of autophagosome with double-membrane structure in cytoplasm. AO staining showed the existence of AVOs. Simultaneously, the expressions of autophagy-related proteins, MAP-LC3 and the mRNA level of beclin 1 were elevated by ORI. The autophagy inhibitor 3-MA reversed the elevation of beclin 1 mRNA. CONCLUSION: The growth of PC-3 cells is inhibited. And cellular is induced by oridonin with a potential anti-tumor effect.