Diosgenin inhibits proliferation and migration of ovarian cancer cells and induce apoptosis via upregulation of PTEN.

Diosgenin, a natural steroidal sapogenin, has recently attracted a high amount of attention, as an effective anticancer agent in ovarian cancer. However, diosgenin mediated anticancer impacts are still not completely understood. Thus, the present study evaluated the effect of diosgenin on the proliferation, apoptosis, and metastasis of ovarian cancer cells. OVCAR-3 and SKOV-3 cells were treated with diosgenin, cellular viability was assessed by MTT assay and apoptosis was measured by ELISA and evaluated the protein expression levels of apoptotic markers through western blotting. Cell migration was examined by measuring the mRNA levels of genes involved in the cell invasion. The protein expression levels of main components of PI3K signaling were evaluated via western blotting. Diosgenin led to significant inhibition of cellular proliferation in a dose-dependent manner. It also induced apoptosis through upregulating pro-apoptotic markers and downregulating antiapoptotic mediators. In addition, OVCAR-3 cells exposure to diosgenin decreased cell migration and invasion. More importantly, diosgenin downregulated the expression levels of main proteins in PI3K signaling including PI3K, Akt, mTOR, and GSK3. Diosgenin inhibited the proliferation and migration of OVCAR-3 ovarian cancer cells and induced apoptosis, which may be mediated by targeting PI3K signaling.

Astragaloside IV inhibits idiopathic pulmonary fibrosis through activation of autophagy by miR-21-mediated PTEN/PI3K/AKT/mTOR pathway.

As the main active ingredient of Astragalus, Astragaloside IV (AS-IV) can ameliorate pulmonary fibrosis. In this experiment, we studied how AS-IV reduces idiopathic pulmonary fibrosis (IPF). Bleomycin (BLM) or TGF-ß1 was treated in mice or alveolar epithelial cells to mimic IPF in vivo as well as in vitro. ASV-IV alleviated levels of inflammatory cytokines and fibrosis markers in IPF model. Through detection of autophagy-related genes, ASV-IV was observed to induce autophagy in IPF. Besides, ASV-IV inhibited miR-21 expression in IPF models, and overexpression of miR-21 could reverse the protective potential of ASV-IV on IPF. PTEN was targeted by miR-21 and was up-regulated by ASV-IV in IPF models. In addition, levels of inflammatory cytokines and fibrosis markers, autophagy, as well as the PI3K/AKT/mTOR pathway regulated by ASV-IV could be neutralized after treatment with autophagy inhibitors, miR-21 mimics, or si-PTEN. Our study demonstrates that ASV-IV inhibits IPF through activation of autophagy by miR-21-mediated PTEN/PI3K/AKT/mTOR pathway, suggesting that ASV-IV could be acted to be a promising therapeutic method for IPF.

Endometriosis derived exosomal miR-301a-3p mediates macrophage polarization via regulating PTEN-PI3K axis.

This study aimed to explore the effects of endometriosis (EMS)-derived exosomes and miR-301a-3p on the polarization of macrophages and investigate the involved molecular mechanism. The exosomes were isolated from ectopic endometrial tissues of EMS patients and normal human serum (NHS). Results of transmission electron microscope and Nanoparticle Tracking Analysis showed that both EMS-exosomes and NHS-exosomes are about 80 nm microvesicles. Exosomal markers CD63 and TSG101 were abundantly expressed in both EMS-exosomes and NHS-exosomes. No negative marker Calnexin was detected in NHS-exosomes. A small amount of Calnexin was detected in EMS-exosomes. THP-1 cells differentiatee to macrophages by incubating with phorbol-12-myristate-13-acetate. Effects of the exosomes on the phagocytosis and polarization of macrophages were evaluated by PKH26 fluorescent labeling and flow cytometry, respectively. Compared with the NHS-exosomes group, the phagocytic capacity of macrophages was reduced and the polarization of macrophages to M2 macrophages was promoted after EMS-exosomes treatment. Results of western blot showed that compared with the NHS-exosomes group, the EMS-exosomes treatment significantly up-regulated the expression of phosphatidylinositol 3-kinase (PI3K) and down-regulated the expression of phosphatase and tensin homologue deleted on chromosome 10 (PTEN). miR-301a-3p mimic, negative control (NC) mimic, miR-301a-3p inhibitor and NC inhibitor were transfected into cells. Transfection efficiency was confirmed by RT-qPCR. Effects of the miR-301a-3p expression on the macrophages polarization and the expression of Arg-1, PTEN and PI3K in the macrophages were evaluated by flow cytometry and western blot, respectively. miR-301a-3p overexpression significantly enhanced the ability of EMS-exosomes-inducing M2 transformation of macrophages, promoted the expression of Arg-1 and PI3K, and inhibited the PTEN expression. miR-301a-3p inhibitor significantly reduced the expression of Arg-1 and PI3K and promoted the PTEN expression. In conclusion, EMS derived exosomal miR-301a-3p mediated macrophage polarization via regulating PTEN-PI3K axis.

Mesenchymal stem cell-originated exosomal circDIDO1 suppresses hepatic stellate cell activation by miR-141-3p/PTEN/AKT pathway in human liver fibrosis.

Liver fibrosis is a common pathologic stage of the development of liver failure. It has showed that exosomes loaded with therapeutic circRNAs can be manufactured in bulk by exosome secreted cells in vitro, thus enabling personalized treatment. This study aimed to investigate the role of exosome-based delivery of circDIDO1 in liver fibrosis. Levels of genes and proteins were examined by qRT-PCR and Western blot. Cell proliferation, apoptosis, and cell cycle were analyzed by using cell counting kit-8 (CCK-8) assay, EdU assay, and flow cytometry, respectively. The binding between circDIDO1 and miR-141-3p was confirmed by dual-luciferase reporter, RNA pull-down and RIP assays. Exosomes were isolated by ultracentrifugation, and qualified by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and Western blot. CircDIDO1 overexpression or miR-141-3p inhibition suppressed the proliferation, reduced pro-fibrotic markers, and induced apoptosis as well as cell cycle arrest in hepatic stellate cells (HSCs) by blocking PTEN/AKT pathway. Mechanistically, circDIDO1 acted as an endogenous sponge for miR-141-3p, further rescue experiments showed that circDIDO1 suppressed HSC activation by targeting miR-141-3p. Extracellular circDIDO1 could be incorporated into exosomes isolated from mesenchymal stem cells (MSCs), and transmitted to HSCs to restrain HSC activation. Clinically, low levels of serum circDIDO1 in exosome were correlated with liver failure, and serum exosomal circDIDO1 had a well diagnostic value for liver fibrosis in liver failure patients. Transfer of circDIDO1 mediated by MSC-isolated exosomes suppressed HSC activation through the miR-141-3p/PTEN/AKT pathway, gaining a new insight into the prevention of liver fibrosis in liver failure patients.

Non-small cell lung cancer cell-derived exosomal miR-17-5p promotes osteoclast differentiation by targeting PTEN.

Aberrant activity of bone resorbing osteoclasts plays a key role in the development of osteoporosis and cancer bone metastasis. The identification of novel and specific targets will be helpful for the development of new therapeutic strategies for bone metastasis in lung cancer. Herein, we examined microRNAs in tumor cell-derived exosomes to investigate the communication between the bone environment and tumor cells. TCGA database analysis showed that the level of miR-17-5p increased in non-small cell lung cancer tissues compared with non-tumor tissues. To investigate the function of exosomes in inducing osteoclastogenesis, osteoclast precursors were incubated with exosomes isolated from non-small cell lung cancer cell line, as well as receptor activator of NF-KB ligand and M-CSF to induce osteoclastogenesis. We found that exosomal miR-17-5p is upregulated in a non-small cell lung cancer cell line with bone metastasis compared with the original cell line. Overexpression of miR-17-5p enhanced the osteoclastogenesis of RAW264.7 cells. PTEN was identified as a direct target of miR-17-5p and showed negative effects on osteoclastogenesis. Importantly, treatment of LY294002 (an inhibitor of the PI3K/Akt pathway) attenuated miR-17-5p-mediated osteoclastogenesis effects. Taken together, our findings demonstrated that miR-17-5p promotes osteoclastogenesis through the PI3K/Akt pathway via targeting PTEN in lung cancer.

Co-administration of apigenin with doxorubicin enhances anti-migration and antiproliferative effects via PI3K/PTEN/AKT pathway in prostate cancer cells.

Prostate cancer is one of the leading cancers in men, and new approaches are needed for its treatment. The aim of this study was to investigate the effect of co-administration of naturally occurring flavone apigenin and doxorubicin to androgen-insensitive prostate cancer cells. METHODS: The effect of the treatment on survival and migration of human PC3 cells was evaluated by MTT and scratch assay, respectively. Apoptosis and cell cycle distribution were detected by image-based cytometry. mRNA and protein expression were determined by real-time quantitative polymerase chain reaction and Western blot, respectively. RESULTS: Apigenin and doxorubicin dose-dependently inhibited cell survival, and co-administration of both agents significantly induced cell death via upregulating the mRNA expression of caspases, Bax and cytochrome c, and downregulating Bcl-XL. Combination therapy caused cell cycle arrest by upregulating the expression of p21 and p27. The treatment modality inhibited cell migration via downregulating Snail, Twist and MMPs in which doxorubicin was ineffective. Apigenin dephosphorylated Akt strongly, significantly suppressed ERK phosphorylation, and increased PTEN expression 4.5-fold. The combination of apigenin and doxorubicin inhibited PI3K and AKT phosphorylation more strongly than a single administration. CONCLUSIONS: Our data indicate that a combination of the natural flavone apigenin with doxorubicin might have a potential in treatment of castration-resistant prostate cancer.

Novel Therapies for Metastatic Triple-Negative Breast Cancer: Spotlight on Immunotherapy and Antibody-Drug Conjugates.

Background: Triple-negative breast cancer (TNBC) is a biologically heterogeneous disease that is often associated with worse outcomes compared with other subtypes such as hormone receptor-positive tumors and HER2-positive tumors. While chemotherapy remains the mainstay of standard therapy for metastatic TNBC (mTNBC), several novel treatments have been developed over the past few years. In this review article, we review the major developments in the management of patients with mTNBC. Summary: The combination of chemotherapy and immunotherapy is a potential therapeutic option for PD-L1-positive mTNBC, as the FDA recently approved atezolizumab (Tecentriq) and pembrolizumab (Keytruda) in combination with chemotherapy. Also, 2 targeted therapies-olaparib (Lynparza) and talazoparib (Talzenna)-are FDA approved for the management of mTNBC with germline BRCA mutations, and sacituzumab govitecan, an anti-Trop2 antibody-drug conjugate (ADC), was recently approved for previously treated mTNBC. A number of promising therapies are on the horizon, including AKT inhibitors for PI3K-altered TNBC as well as other ADCs. Key Message: The successful clinical development of immunotherapies, PARP inhibitors, and ADCs for the management of mTNBC has improved the survival outcome of patients. Over the coming years, the therapeutic developments in precision medicine will likely change the mTNBC landscape, and might make the current definition of TNBC as breast cancer that is estrogen receptor negative, progesterone receptor negative, and HER2 negative obsolete.

Silencing of miR-302b-3p alleviates isoflurane-induced neuronal injury by regulating PTEN expression and AKT pathway.

Isoflurane (ISO) is an anesthesia and can result in neuron injury. A previous study has indicated that microRNA-302b-3p (miR-302b-3p) exerts a crucial function in modulating cerebral ischemia/reperfusion damage-induced neuronal injury. We sought to examine the role of miR-302b-3p in ISO-induced neuronal injury. In the present study, the effects of miR-302b-3p on ISO-induced neuron injury were investigated by MTT and TUNEL assays. We discovered that ISO stimulation led to miR-302b-3p upregulation and neuronal injury. MiR-302b-3p silencing exerted protective effects against ISO induced neuronal injury. In addition, phosphatase and tensin homologue deleted on chromosome 10 (PTEN) was a direct downstream target gene of miR-302b-3p. MiR-302b-3p targets the 3'UTR of PTEN to inhibit its mRNA expression, and further reduces its protein expression. Silencing of PTEN partially reversed the protecting effects of silenced miR-302b-3p on ISO-induced injury of hippocampal neurons. Further, miR-302b-3p activated the AKT signaling pathway in neurons exposed to ISO by downregulation of PTEN. Finally, in vivo studies revealed that silencing of miR-302b-3p alleviates ISO-induced injury and spatial memory impairment of rats partly by upregulation of PTEN. Overall, our findings indicated that miR-302b-3p targets PTEN to activate the AKT pathway, and silencing of miR-302b-3p plays a neuroprotective role in ISO-induced neuronal injury by the PTEN/AKT pathway, suggesting miR-302b-3p as a crucial target for ISO-induced neuronal injury.

Propofol Affects Non-Small-Cell Lung Cancer Cell Biology By Regulating the miR-21/PTEN/AKT Pathway In Vitro and In Vivo.

BACKGROUND: Propofol is a common sedative-hypnotic drug traditionally used for inducing and maintaining general anesthesia. Recent studies have drawn attention to the nonanesthetic effects of propofol, but the potential mechanism by which propofol suppresses non-small-cell lung cancer (NSCLC) progression has not been fully elucidated. METHODS: For the in vitro experiments, we used propofol (0, 2, 5, and 10 µg/mL) to treat A549 cells for 1, 4, and 12 hours and Cell Counting Kit-8 (CCK-8) to detect proliferation. Apoptosis was measured with flow cytometry. We also transfected A549 cells with an microribonucleic acid-21 (miR-21) mimic or negative control ribonucleic acid (RNA) duplex and phosphatase and tensin homolog, deleted on chromosome 10 (PTEN) small interfering ribonucleic acid (siRNA) or negative control. PTEN, phosphorylated protein kinase B (pAKT), and protein kinase B (AKT) expression were detected using Western blotting, whereas miR-21 expression was examined by real-time polymerase chain reaction (RT-PCR). In vivo, nude mice were given injections of A549 cells to grow xenograft tumors; 8 days later, the mice were intraperitoneally injected with propofol (35 mg/kg) or soybean oil. Tumors were then collected from mice and analyzed by immunohistochemistry and Western blotting. RESULTS: Propofol inhibited growth (1 hour, P = .001; 4 hours, P ≤ .0001; 12 hours, P = .0004) and miR-21 expression (P ≤ .0001) and induced apoptosis (1 hour, P = .0022; 4 hours, P = .0005; 12 hours, P ≤ .0001) in A549 cells in a time and concentration-dependent manner. MiR-21 mimic and PTEN siRNA transfection antagonized the suppressive effects of propofol on A549 cells by decreasing PTEN protein expression (mean differences [MD] [95% confidence interval {CI}], -0.51 [-0.86 to 0.16], P = .0058; MD [95% CI], 0.81 [0.07-1.55], P = .0349, respectively), resulting in an increase in pAKT levels (MD [95% CI] = -0.82 [-1.46 to -0.18], P = .0133) following propofol exposure. In vivo, propofol treatment reduced NSCLC tumor growth (MD [95% CI] = -109.47 [-167.03 to -51.91], P ≤ .0001) and promoted apoptosis (MD [95% CI] = 38.53 [11.69-65.36], P = .0093). CONCLUSIONS: Our study indicated that propofol inhibited A549 cell growth, accelerated apoptosis via the miR-21/PTEN/AKT pathway in vitro, suppressed NSCLC tumor cell growth, and promoted apoptosis in vivo. Our findings provide new implications for propofol in cancer therapy and indicate that propofol is extremely advantageous in surgical treatment.

Statins activate the NLRP3 inflammasome and impair insulin signaling via p38 and mTOR.

Statins lower cholesterol and risk of cardiovascular disease. Statins can increase blood glucose and risk of new-onset diabetes. It is unclear why statins can have opposing effects on lipids versus glucose. Statins have cholesterol-independent pleiotropic effects that influence both insulin and glucose control. Statin lowering of isoprenoids required for protein prenylation promotes pancreatic ß-cell dysfunction and adipose tissue insulin resistance. Protein prenylation influences immune function and statin-mediated adipose tissue insulin resistance involves the NLR family pyrin domain-containing 3 (NLRP3) inflammasome and IL-1ß. However, the intracellular cues that statins engage to activate the NLRP3 inflammasome and those responsible for IL-1ß-mediated insulin resistance in adipose tissue have not been identified. We hypothesized that stress kinases or components of the insulin signaling pathway mediated statin-induced insulin resistance. We tested the associations of p38, ERK, JNK, phosphatase, and tensin homolog (PTEN), and mTOR in statin-exposed adipose tissue from WT and IL-1ß-/- mice. We found that statins increased phosphorylation of p38 in WT and IL-1ß-/- mice. Statin activation of p38 upstream of IL-1ß led to priming of this NLRP3 inflammasome effector in macrophages. We found that mTORC1 inhibition with low doses of rapamycin (2 or 20 nM) lowered macrophage priming of IL-1ß mRNA and secretion of IL-1ß caused by multiple statins. Rapamycin (20 nM) or the rapalog everolimus (20 nM) prevented atorvastatin-induced lowering of insulin-mediated phosphorylation of Akt in mouse adipose tissue. These results position p38 and mTOR as mediators of statin-induced insulin resistance in adipose tissue and highlight rapalogs as candidates to mitigate the insulin resistance and glycemic side effects of statins.

Neuroprotective effects of andrographolide on chronic cerebral hypoperfusion-induced hippocampal neuronal damage in rats possibly via PTEN/AKT signaling pathway.

To explore the potential effects of andrographolide on chronic cerebral hypoperfusion (CCH)-induced neuronal damage as well as the underlying mechanisms. Rat CCH model was established by 2-vessel occlusion (2VO). The CCH rats received andrographolide treatment for 4 weeks. The neuron loss was detected by using neuronal nuclei (NeuN) immunofluorescent staining. The expression levels of phospho-phosphatase and tensin homolog deleted on chromosome ten (p-PTEN), protein kinase B (AKT), p-AKT, and cysteinyl aspartate specific proteinase-3 (Caspase-3) proteins were accessed by Western blotting. Moreover, the neuronal apoptosis of hippocampus tissues was detected via terminal deoxynucleotidyl transferase- mediated dUTP nick end labeling (TUNEL) staining. CCH reduced the number of NeuN-positive cells, while the number was significant increased after andrographolide treatment. CCH increased the proteins expression level of p-PTEN, Caspase-3, and decreased the p-AKT, which were reversed by andrographolide treatment. Furthermore, andrographolide treatment also down-regulated CCH-induced TUNEL-apoptosis rate. Our results suggest that the PTEN/AKT pathway may be modulated by andrographolide and the damaging effects of CCH on hippocampus may be ameliorated by andrographolide treatment. Andrographolide may act as a potential therapeutic approach for chronic ischemic insults.

Mangiferin Alleviates Renal Interstitial Fibrosis in Streptozotocin-Induced Diabetic Mice through Regulating the PTEN/PI3K/Akt Signaling Pathway.

Renal interstitial fibrosis is considered to be the typical manifestation of diabetic nephropathy (DN). Mangiferin has shown positive effect on the prevention or treatment of diabetes and its complications. The aim of this study was to explore the inhibitive effect and mechanism of mangiferin on renal interstitial fibrosis in diabetic mice. Streptozotocin- (STZ-) induced diabetic mice were treated with mangiferin (15, 30, and 60 mg/kg/d) for 4 weeks. The morphology of kidneys was observed by Masson's trichrome staining, and the biochemical parameters (fasting blood glucose (FBG), triglyceride (TG), total cholesterol (TC), blood urea nitrogen (BUN), serum creatinine (SCr), and urine protein) were determined by kits. In addition, the levels of inflammatory cytokines (tumor necrosis factor-α (TNF-α), interleukin- (IL-) 6, and IL-1ß), antioxidant enzymes (SOD, CAT, and GSH-Px), MDA, and ROS were assessed. Furthermore, the expressions of fibronectin (FN), collagen I (Col I), and α-SMA were measured by immunohistochemistry. Regulations of TGF-ß1 and the PTEN/PI3K/Akt pathway were detected by Western blotting. Treatment with mangiferin significantly ameliorated renal dysfunction in diabetic mice, as evidenced by the increase in body weight and decreases in FBG, TG, TC, BUN, SCr, urine protein, and the kidney to body weight ratio (KW/BW). Furthermore, mangiferin treatment prevented renal interstitial fibrosis evidenced by decreases in the positive expression of FN, Col I, and α-SMA, in comparison with morphological changes in the renal tissue. Meanwhile, mangiferin increased antioxidant enzymes, reduced the TNF-α, IL-6, and IL-1ß, as well as MDA and ROS. Additionally, mangiferin administration also downregulated TGF-ß1, upregulated PTEN, and decreased the phosphorylation of both PI3K and Akt. These findings demonstrate that mangiferin may reduce inflammation and oxidative stress in DN, thereby inhibiting the renal interstitial fibrosis by reducing the TGF-ß1-mediated elevation of Col I, FN, and α-SMA through the PTEN/PI3K/Akt pathway.

DJ-1-binding compound B enhances Nrf2 activity through the PI3-kinase-Akt pathway by DJ-1-dependent inactivation of PTEN.

DJ-1 was identified as an oncogene and also as a causative gene for a familial form of Parkinson disease (PD). DJ-1 plays various roles in anti-oxidative stress response. Superfluous oxidation of DJ-1 at cysteine residue 106 (C106), an inactive form of DJ-1, was observed in PD patients. DJ-1-binding compound B, which specifically bound to the C106 region of DJ-1, has been isolated and it has been shown to prevent oxidative stress-induced cell death through maintaining active forms of DJ-1 by inhibiting its superfluous oxidation. The molecular mechanism of the action of compound B, however, has not been fully elucidated. In this study, we found that compound B stimulated transcriptional activity of Nrf2 in H2O2-treated SH-SY5Y cells by inhibiting its degradation through the ubiquitin-proteasome system. Although Keap 1 is a major negative regulator of Nrf2, compound B strongly increased Nrf2 activity in Keap1-mutant A549 cells but not in PTEN-null PC3 and PTEN-knockout SH-SY5Y cells. Furthermore, treatment of cells with inhibitors of the PI3-kinase/Akt pathway inhibited the effect of compound B, and compound B increased the binding of PTEN to DJ-1 and decreased lipid phosphatase activity of PTEN concomitantly with increased oxidation of PTEN, an inactive form of PTEN. These results suggest that compound B enhances transcriptional activity of Nrf2 under an oxidative stress condition in a Keap1-independent manner and that its activity is elicited by activation of the PI3Kinase/Akt pathway with DJ-1-dependent inactivation of PTEN, leading to protection of oxidative stress-induced cell death.

In situ self-assembling Au-DNA complexes for targeted cancer bioimaging and inhibition.

Cancer remains one of the most challenging diseases to treat. For accurate cancer diagnosis and targeted therapy, it is important to assess the localization of the affected area of cancers. The general approaches for cancer diagnostics include pathological assessments and imaging. However, these methods only generally assess the tumor area. In this study, by taking advantage of the unique microenvironment of cancers, we effectively utilize in situ self-assembled biosynthetic fluorescent gold nanocluster-DNA (GNC-DNA) complexes to facilitate safe and targeted cancer theranostics. In in vitro and in vivo tumor models, our self-assembling biosynthetic approach allowed for precise bioimaging and inhibited cancer growth after one injection of DNA and gold precursors. These results demonstrate that in situ bioresponsive self-assembling GNC-PTEN (phosphatase and tensin homolog) complexes could be an effective noninvasive technique for accurate cancer bioimaging and treatment, thus providing a safe and promising cancer theranostics platform for cancer therapy.

Peroxiredoxin III Protects Tumor Suppressor PTEN from Oxidation by 15-Hydroperoxy-eicosatetraenoic Acid.

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a lipid and protein phosphatase that coordinates various cellular processes. Its activity is regulated by the reversible oxidation of an active-site cysteine residue by H2O2 and thioredoxin. However, the potential role of lipid peroxides in the redox regulation of PTEN remains obscure. To evaluate this, 15-hydroperoxy-eicosatetraenoic acid (15s-HpETE), a lipid peroxide, was employed to investigate its effect on PTEN using molecular and cellular-based assays. Exposure to 15s-HpETE resulted in the oxidation of recombinant PTEN. Reversible oxidation of PTEN was also observed in mouse embryonic fibroblast (MEF) cells treated with a 15s-HpETE and Lipofectamine mixture. The oxidative dimerization of thioredoxin was found simultaneously. In addition, the absence of peroxiredoxin III aggravated 15s-HpETE-induced PTEN oxidation in MEF cells. Our study provides novel insight into the mechanism linking lipid peroxidation to the etiology of tumorigenesis.

Polyoxometalate SbW9 regulates proliferation and apoptosis of NSCLC cells via PTEN-dependent AKT signaling pathway.

OBJECTIVE: To explore the influence of polyoxometalate SbW9 on proliferation and apoptosis of non-small cell lung cancer (NSCLC) cells and its mechanism. MATERIALS AND METHODS: NSCLC cell lines A549 and PC9 were treated with 50 µM polyoxometalate. Then, the proliferation of NSCLC cells was detected via 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-t tetrazolium hydroxide (XTT) assay and colony formation assay; the apoptosis of NSCLC cells was detected via flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL); and the expression of apoptosis-related proteins, B-cell lymphoma-2 (Bcl-2), and Bcl-2 associated X protein (Bax), was detected via Western blotting. Moreover, the protein expression levels of phosphatase and tensin homolog deleted on chromosome ten (PTEN), phosphorylated-protein kinase B (P-AKT) and total AKT (T-AKT) were detected via Western blotting. RESULTS: The polyoxometalate inhibited the proliferation of A549 and PC9 cells in a concentration-dependent manner (5-100 µM) (p<0.05), and it (50 µM) also inhibited the proliferation of both cells in a time-dependent manner (0-72 h) (p<0.05). The results of colony formation assay revealed that the polyoxometalate (50 µM) could significantly inhibit the colony formation of A549 and PC9 cells (p<0.05). The results of flow cytometry and TUNEL staining showed that the polyoxometalate (50 µM) significantly induced the apoptosis of A549 and PC9 cells (p<0.05). According to further studies, the polyoxometalate (50 µM) inhibited the expression of anti-apoptotic gene Bcl-2 and promoted the expression of pro-apoptotic gene Bax. Besides, the Western blotting results manifested that the polyoxometalate could activate the expression of PTEN and inhibit the phosphorylation of downstream AKT (p<0.05). CONCLUSIONS: The polyoxometalate can activate the expression of PTEN to inhibit the phosphorylation of AKT, ultimately inhibiting the proliferation and inducing the apoptosis of NSCLC cells. Therefore, the polyoxometalate is expected to become a novel drug for the clinical treatment of NSCLC.

Ellagic acid, extracted from Sanguisorba officinalis, induces G1 arrest by modulating PTEN activity in B16F10 melanoma cells.

In Chinese medicine, herbal medicine is commonly used to treat individuals suffering from many types of diseases. We thus expected that some herbal medicines would contain promising compounds for cancer chemotherapy. Indeed, we found that Sanguisorba officinalis extracts strongly inhibit the growth of B16F10 melanoma cells, and we identified ellagic acid (EA) as the responsible ingredient. B16F10 cells treated with EA exhibited strong G1 arrest accompanied by accumulation of p53, followed by inactivation of AKT. Addition of a PTEN inhibitor, but not a p53 inhibitor, abrogated the EA-induced AKT inactivation and G1 arrest. The PTEN inhibitor also diminished EA-induced p53 accumulation. Furthermore, EA apparently increased the protein phosphatase activity of PTEN, as demonstrated by the reduced phosphorylation level of FAK, a protein substrate of PTEN. Furthermore, an in vitro PTEN phosphatase assay on PIP3 showed the direct modulation of PTEN activity by EA. These results suggest that EA functions as an allosteric modulator of PTEN, enhancing its protein phosphatase activity while inhibiting its lipid phosphatase activity. It is notable that a combination of EA and cisplatin, a widely used chemotherapy agent, dramatically enhanced cell death in B16F10 cells, suggesting a promising strategy in chemotherapy.

An update on PTEN modulators - a patent review.

Introduction: A multitude of cellular and physiological functions have been attributed to the biological activity of PTEN (Phosphatase and tensin homolog) such as inhibiting angiogenesis, promoting apoptosis, preventing cell proliferation, and maintaining cellular homeostasis. Based on whether cell growth is needed to be initiated or to be inhibited, enhancing PTEN expression or seeking to inhibit it was pursued. Areas covered: Here the authors provide recent updates to their previous publication on 'PTEN modulators: A patent review', and discuss on new specificities that affirm the therapeutic potential of PTEN in promoting neuro-regeneration, stem cell regeneration, autophagy, bone and cartilage regeneration. Also, targeting PTEN appears to be effective in developing new treatment strategies for Parkinson's disease, Alzheimer's disease, macular degeneration, immune disorders, asthma, arthritis, lupus, Crohn's disease, and several cancer types. Expert opinion: PTEN mainly inhibits the PI3k/Akt pathway. However, the PI3k/Akt pathway can be activated by other signaling proteins. Thus, novel treatment strategies that can regulate PTEN alone, or combinational treatment approaches that can induce PTEN and simultaneously affect downstream mediators in the PI3K/Akt pathway, are needed, which were not investigated in detail. Commercial interests associated with molecules that regulate PTEN are discussed here, along with limitations and new possibilities to improve them.

Jarid2 enhances the progression of bladder cancer through regulating PTEN/AKT signaling.

AIMS: Jumonji AT-rich interactive domain 2 (Jarid2) is an interacting component of PRC2 which catalyzes methylation of H3K27 (H3K27me3) and causes the downregulation of PTEN. In the present study, we aimed to explore whether Jarid2 could interact with H3K27me3 to regulate PTEN expression in bladder cancer. MAIN METHODS: Jarid2 expression in bladder cancer tissues and cells were determined by western blotting and RT-PCR. CCK-8, flow cytometry, transwell chamber and in vivo xenograft assays were performed to assess cell growth, apoptosis, migration and tumorigenesis, respectively. Chromatin immunoprecipitation (ChIP) assay was used to assess the methylation of PTEN. KEY FINDINGS: Jarid2 expression was increased in bladder cancer tissues and cells. Downregulation of Jarid2 with shRNA transfection obviously inhibited the proliferation, migration and tumorigenesis of bladder cancer T24 and HT-1376 cells and induced cell apoptosis. Jarid2 downregulation decreased the expression of p-AKT and increased PTEN expression. Besides, Jarid2 down-regulation repressed the epithelial-mesenchymal transition (EMT), whereas knockdown of PTEN impaired this effect. Moreover, upregulation of Jarid2 increased the combination of PTEN promoter and H3K27me3, and 5-aza-CdR rescued it. Meanwhile, 5-aza-CdR administration abolished Jarid2 roles in the promotion of EMT process and AKT activation, as well as the reduction of PTEN expression. SIGNIFICANCE: Overall, the present study elaborated that Jarid2 facilitated the progression of bladder cancer through H3K27me3-mediated PTEN downregulation and AKT activation, which might provide a new mechanism for Jarid2 in promoting bladder cancer progression.

ROS play an important role in ATPR inducing differentiation and inhibiting proliferation of leukemia cells by regulating the PTEN/PI3K/AKT signaling pathway.

BACKGROUND: Acute myeloid leukemia (AML) is an aggressive and mostly incurable hematological malignancy with frequent relapses after an initial response to standard chemotherapy. Therefore, novel therapies are urgently required to improve AML clinical outcomes. 4-Amino-2-trifluoromethyl-phenyl retinate (ATPR), a novel all-trans retinoic acid (ATRA) derivative designed and synthesized by our team, has been proven to show biological anti-tumor characteristics in our previous studies. However, its potential effect on leukemia remains unknown. The present research aims to investigate the underlying mechanism of treating leukemia with ATPR in vitro. METHODS: In this study, the AML cell lines NB4 and THP-1 were treated with ATPR. Cell proliferation was analyzed by the CCK-8 assay. Flow cytometry was used to measure the cell cycle distribution and cell differentiation. The expression levels of cell cycle and differentiation-related proteins were detected by western blotting and immunofluorescence staining. The NBT reduction assay was used to detect cell differentiation. RESULTS: ATPR inhibited cell proliferation, induced cell differentiation and arrested the cell cycle at the G0/G1 phase. Moreover, ATPR treatment induced a time-dependent release of reactive oxygen species (ROS). Additionally, the PTEN/PI3K/Akt pathway was downregulated 24 h after ATPR treatment, which might account for the anti-AML effects of ATPR that result from the ROS-mediated regulation of the PTEN/PI3K/AKT signaling pathway. CONCLUSIONS: Our observations could help to develop new drugs targeting the ROS/PTEN/PI3K/Akt pathway for the treatment of AML.