Tension Homolog Research Articles

Exosomes from nicotine-stimulated macrophages accelerate atherosclerosis through miR-21-3p/PTEN-mediated VSMC migration and proliferation.

Rationale: During the development of atherosclerosis, macrophages secrete exosomes that regulate vascular smooth muscle cells (VSMCs); however, whether nicotine, a major constituent of cigarettes, can modulate this communication in the context of atherogenesis remains to be further studied. In this study, we hypothesized that nicotine induces macrophages to secrete atherogenic exosomes containing microRNAs (miRNAs) to mediate cell-to-cell crosstalk and encourage proatherogenic phenotypes of VSMCs.Methods: In an in vivo study, nicotine was administered subcutaneously to 8-week-old male ApoE-/- mice fed a high-fat diet (HFD) for 12 weeks. Oil red O and hematoxylin and eosin (HE) were used to stain atherosclerotic lesions. Lesion macrophages, VSMCs and exosomes were stained for CD68, α-smooth muscle actin (α-SMA) and CD9, and plaque exosomes were observed by transmission electron microscopy (TEM). Exosomes derived from control macrophages (M-Exos) and from nicotine-treated macrophages (NM-Exos) were isolated by ultracentrifugation, purified by sucrose density gradient centrifugation and characterized based on specific morphology and surface markers. The IVIS® Spectrum in vivo imaging system showed the biodistribution of NM-Exos and M-Exos in circulation. Chitosan hydrogel-incorporated exosomes were applied to simulate exosome secretion in situ. Scratch wound assay, transwell assay and EdU staining were conducted to assess the effects of NM-Exos on the migration and proliferation of mouse VSMCs. RNA-seq was performed to determine the miRNA profiles of M-Exos and NM-Exos. Quantitative real-time PCR (qRT-PCR) analysis was conducted to detect the expression levels of miRNAs and mRNAs. The roles of the candidate miRNA and its target gene were assessed using specific RNA inhibitors, siRNAs and miRNA mimics. Western blotting was used to detect candidate protein expression levels. A dual-luciferase reporting system was utilized to confirm the binding of a specific miRNA to its target gene.Results: Nicotine induced atherosclerotic lesion progression and resulted in plaque exosome retention in vivo. The biodistribution of NM-Exos showed that plaque-resident exosomes might be secreted in situ. VSMCs cocultured in vitro with nicotine-stimulated macrophages presented an increased capacity for migration and proliferation, which was exosome-dependent. In addition, isolated NM-Exos helped promote VSMC migration and proliferation. miRNA profiling showed that miR-21-3p was enriched in NM-Exos, and this miRNA was shown to play a key role in regulating NM-Exos-induced effects by directly targeting phosphatase and tension homologue (PTEN).Conclusion: Exosomal miR-21-3p from nicotine-treated macrophages may accelerate the development of atherosclerosis by increasing VSMC migration and proliferation through its target PTEN.

Analysis of PTEN expression and promoter methylation in Uyghur patients with mild type 2 diabetes mellitus.

Phosphatase and tension homolog deleted on chromosome 10 (PTEN) was considered as a promising target in type 2 diabetes mellitus (T2DM) because of its negative effects on insulin resistance. Alteration in DNA methylation is thought to play a role in the pathogenesis of T2DM. The aim of the present study was to quantitatively evaluate the promoter methylation of PTEN in Uyghur patients with mild T2DM. We evaluated methylation levels in 21 CpG sites from −2515 bp to −2186 bp relative to the translation initiation site in 55 cases of T2DM and 50 cases of normal glucose tolerance (NGT) using the MassARRAY spectrometry. In addition, PTEN mRNA and protein levels were measured by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and western blotting to determine whether DNA methylation alterations were responsible for PTEN expression. Compared with NGT groups, the PTEN mRNA expression was significantly higher in Uyghur patients with mild T2DM groups. We also showed that PTEN protein expression was upregulated in Uyghur patients with mild T2DM groups, but the level of protein kinase B (AKT) was downregulated. PTEN methylation in T2DM patients was significantly lower than that in NGT groups. In addition, 2 CpG units demonstrated a significant difference between the NGT and Uyghur patients with mild T2DM groups. Furthermore, there was a negative association between promoter methylation and PTEN expression. Together, these findings suggest that epigenetic inactivation of PTEN plays an important role in Uyghur patients with mild T2DM. The aberrant methylation of CpG sites within the PTEN promoter may serve as a potential candidate biomarker for T2DM in the Uyghur population.

Total flavonoids from Smilax glabra Roxb blocks epithelial-mesenchymal transition and inhibits renal interstitial fibrosis by targeting miR-21/PTEN signaling.

Smilax glabra Roxb, a traditional Chinese herb, has been widely used in folk medicine. The current study was performed to investigate the protective effect of S. glabra Roxb extract, pure total flavonoids from Smilax glabra Roxb (PTFS), on renal interstitial fibrosis (RIF) and its underlying mechanism. First, a surgical model of unilateral ureteral obstruction was established in rats to induce RIF. Then, rats were grouped and treated with PTFS at different concentration. Second, HK-2 cells underwent an epithelial-mesenchymal transition (EMT) by the addition of transforming growth factor-β1 (TGF-β1). Additionally, HK-2 cells after inducing for EMT were transfected with microRNA-21 (miR-21) mimic or inhibitor. These HK-2 cells were grouped and treated with PTFS at different concentration. Finally, real-time polymerase chain reaction and Western blot analysis were performed to detect the expression of possible signaling factor involved in RIF in renal tissues or HK-2 cells after PTFS treatment. In vivo and in vitro experiments indicated that PTFS treatment could decrease the expression of α-smooth muscle actin (α-SMA; mesenchymal marker) and increase the expression of E-cadherin (epithelial marker) in both messenger RNA and protein level. Moreover, PTFS also attenuated the expression of TGF-β1/Smad signaling in both renal tissues and HK-2 cells that underwent EMT. Overexpression or inhibition of miR-21 in HK-2 cells activated or blocked the PI3K/Akt signaling via targeting phosphatase and tension homolog (PTEN), and then promoted or suppressed the progress of TGF-β1-induced EMT by regulating the expression of α-SMA and E-cadherin. Furthermore, PTFS treatment inhibited TGF-β1-induced EMT progress by blocking miR-21/PTEN/PI3K/Akt signaling. PTFS has strong anti-EMT and antifibrosis effects both in vitro and in vivo. The mechanism underlying these effects may be related to inhibition of TGF-β1/Smad, and their downstream miR-21/PTEN signaling, leading to blocks of EMT process during RIF.

Expressions and prognostic significance of PTEN and PD-1 protein in patients with classical Hodgkin's lymphoma

目的分析肿瘤免疫耐受信号通路的重要因子PD-1和PTEN在经典型霍奇金淋巴瘤（CHL）患者中的表达及其与患者临床特征和预后的相关性。方法回顾性分析2003年2月至2013年8月诊治的56例CHL患者的临床资料。采用免疫组织化学染色法检测CHL患者PD-1和PTEN蛋白的表达，采用原位杂交法检测EBV及EBV编码的小mRNA（EBER），并结合患者的临床特征与生存状态进行相关性分析。结果①56例患者中，男34例，女22例，中位年龄25（7~71）岁，PTEN阳性者11例（19.64%），PD-1阳性者14例（25.00%）。②PTEN和PD-1表达呈正相关（rs=0.320，P=0.016）；PTEN表达与Ann Arbor分期、IPS评分和有无大包块（≥5 cm）明显相关，PD-1仅与有无大包块相关（P值均<0.05）。③中位随访43（5~86）个月，多因素分析结果显示：年龄≥45岁（P<0.001）、IPS评分>2分（P=0.026）、EBER阳性（P=0.004）、PTEN蛋白高表达（P=0.035）是影响患者5年总生存的不良预后因素，也是影响5年无进展生存的不良预后因素（P值分别为0.007、0.014、0.002、0.024）。结论肿瘤免疫逃逸信号通路因子PTEN与CHL患者的预后相关，对CHL患者的预后判断有一定作用，同时也为CHL的免疫治疗提供了新思路和理论依据。

Down-regulation of miR-192 protects against rat ischemia-reperfusion injury after myocardial infarction.

DJ-1-phosphate and tension homology deleted on chromosome ten/phosphatidylinositol-3-kinase/protein kinase B (PTEN/PI3K/AKT) signaling pathway plays a role in the regulation of ischemic reperfusion (I-R) injury. Bioinformatics analysis demonstrated that there is a complementary binding site between microRNA-192 (miR-192) and the 3'-UTR of DJ-1 mRNA. This study investigated the role of miR-192 in regulating DJ-1-PTEN/PI3K/AKT signaling pathway and myocardial I-R injury. miR-122 and DJ-1 mRNA expressions in myocardial tissue were detected by Real-time PCR (RT-PCR). DJ-1, PTEN, and phosphorylated AKT (p-AKT) protein expressions were tested by Western blot. Reactive oxygen species (ROS) content was measured by flow cytometry. Malondialdehyde (MDA) content and superoxide dismutase (SOD) enzyme activity were detected by the kits. I-R treatment was performed at 72 h after transfection. Cell apoptosis was evaluated with flow cytometry. Compared with sham group, miR-192, PTEN expressions and MDA content were significantly increased (p<0.05), while DJ-1, p-AKT levels and SOD activities were significantly reduced (p<0.05) in myocardial tissue of I-R group. Compared with control, I-R treatment significantly up-regulated miR-192 level, significantly decreased DJ-1 and p-AKT proteins, significantly elevated PTEN expression, and significantly induced apoptosis and ROS production in H9C2 cells (p<0.05). Transfection of miR-192 inhibitor significantly enhanced DJ-1 level, declined PTEN expression, elevated p-AKT level, and restrained apoptosis, ROS production and MDA content, and promoted SOD activity in H9C2 cells under I-R condition. The expression of miR-192 increased significantly, while the expression of DJ-1 reduced obviously during I-R injury after myocardial infarction. Down-regulation of miR-192 markedly enhanced DJ-1 expression and PTEN/PI3K/AKT pathway activity, inhibited cell apoptosis and ROS generation, and reduced I-R injury in cardiomyocytes.

The effect of optic nerve axotomy on retinal PTEN/mTOR activity of adult rat

Objective To investigate the effect of optic nerve axotomy (ONA) on phosphate and tension homology deleted on chromsome ten (PTEN)/mammalian target of rapamycin (mTOR) activity of adult rat retina. Methods Right ONA models of adult rats were established by crushing optic nerve and evaluated with FluoroGold™ labeling retinal ganglion cells (RGCs) retrogradely.The left eyes were intact and served as normal control group. The expression of PTEN and phosphorylated ribosomal protein S6 (pS6), biochemical marker of mTOR activity, were measured with Western blotting assay and immunofluorescence respectively at 7 and 14 days after ONA. Results The completeness of ONA was confirmed by FluoroGold™ retrograde labeling. Compared with normal control group, the expression of PTEN of experimental group was significantly increased at 7 and 14 days after ONA (P=0.0065, 0.0219), meanwhile the expression of pS6 of experimental group was significantly decreased (P=0.0003, 0.0000). Conclusion ONA can stimulate the expression of PTEN and subsequently diminish the mTOR activity of adult rat retina. Key words: Axotomy, optic nerve; PTEN, retina; mTOR

Polymeric nanoparticles decorated with BDNF-derived peptide for neuron-targeted delivery of PTEN inhibitor

Biodegradable nanoparticles (PEG-PCL) decorated with tetra peptides (IKRG) on the surface were evaluated for their potential to deliver drugs into neurons for neural regeneration. The chosen 4-amino-acid peptide sequence was reported previously to mimic the function of BDNF (brain-derived neurotrophic factor) and target TrkB receptors that are present in abundance in neurons. Enhanced uptake for peptide-modified nanoparticles was observed in TrkB-positive PC12 cells but not in TrkB-negative HeLa cells. The modified nanoparticles were internalized selectively into neurons of dorsal root ganglion (DRG) and at a significantly higher rate. VO-OHpic, an inhibitor of PTEN (Phosphatase and tension homolog deleted on chromosome 10), was encapsulated into the modified nanoparticles and released over 14 days. Prolonged and enhanced neural regenerative effect, as confirmed by increased pAKT expression and increased neurite density, was observed when DRGs were treated with drug-containing nanoparticles. This was attributed to the increased and targeted cellular uptake and sustainable release by the peptide-modified nanoparticles. Furthermore, nanoparticle encapsulation was found to reduce the cytotoxicity of the free drug to the neurons. Our findings support that the BDNF-derived peptide modified PEG-PCL nanoparticles are promising carriers for localized and controlled drug delivery to peripheral neurons.

Seed targeting with tiny anti-miR-1297 inhibits EMT in melanoma cells

MicroRNAs (miRNAs) are small, noncoding RNAs that have tissue- and cell-specific expression. They have the ability to regulate the malignant proliferation and transformation of tumour cells. The research focussed on the expression and role of miR-1297 in melanoma. We firstly found that miR-1297 is up-regulated in melanoma tissues and cell lines. Functionally, phosphatase and tension homology deleted on chromsome ten gene (PTEN) was used as a potential target for miR-1297 and detected using Western blotting and immunohistochemistry (IHC). We then used chemical synthesis of anti-miR1297 to explore the influence on melanoma cells and examined the effects on A375 cell proliferation using MTT and western blotting methods. The results showed that anti-miR-1297 transfected A375 cells could inhibit the growth. Furthermore, transfection with anti-miR-1297 reduced PTEN protein expression and partially restrained A375 cells proliferation, migration and reversed Epithelial–Mesenchymal Transition (EMT) progression. In conclusion, we tentatively put forward that miR-1297 might be the key oncomiR in melanoma, and seed-targeted anti-miR-1297 might serve as a new tactic for miR-1297-based therapies.

MicroRNA-126 regulates the phosphatidylinositol-3 kinase (PI3K)/protein kinase B (AKT) pathway in SLK cells in vitro and the expression of its pathway members in Kaposi's sarcoma tissue.

In vitro, microRNA-126 (miR-126) inhibits SLK cell proliferation, inhibits the cell cycle, induces cell apoptosis, and reduces cell invasiveness. Double luciferase assays have shown that phosphatidylinositol-3 kinase (PI3K) is the miR-126 target in SLK cells. We aimed to investigate the influence of miR-126 on the phosphate and tension homology deleted on chromosome ten (PTEN)/PI3K/protein kinase B (AKT) pathway members in SLK cells and to determine the expression of these pathway members in Kaposi's sarcoma (KS). The mimic and inhibitor of miR-126 were transfected into SLK cells and PTEN and AKT1 expression was assayed in SLK cells by real-time quantitative PCR and western blotting. PTEN, AKT1, phosphorylated (P)-PTEN, and phosphorylated (P)-AKT expression in KS and paraneoplastic skin were assayed by immunohistochemistry. AKT1 expression was downregulated in SLK cells that overexpressed miR-126, while there was no significant difference in PTEN expression between SLK cells overexpressing miR-126 and those in which its expression was knocked down. PTEN and AKT1 were expressed in KS and paraneoplastic skin but P-AKT was not. Interestingly, P-PTEN was not expressed in paraneoplastic skin but it was expressed in 90% of KS biopsies (P < .05). P-PTEN expression was also significantly higher in visceral than in cutaneous KS (P = .01) and was higher in indoor than in outdoor workers (P = .018). In vitro, miR-126 negatively regulated AKT1 expression but no regulation of PTEN expression was evident. Results indicated that in KS, PTEN is activated and may therefore be a potential therapeutic target for KS. In addition, these results also indicate that sunlight may not be the cause of KS.

Multifarious Biologic Loaded Liposomes that Stimulate the Mammalian Target of Rapamycin Signaling Pathway Show Retina Neuroprotection after Retina Damage.

A common event in optic neuropathies is the loss of axons and death of retinal ganglion cells (RGCs) resulting in irreversible blindness. Mammalian target of rapamycin (mTOR) signaling pathway agonists have been shown to foster axon regeneration and RGC survival in animal models of optic nerve damage. However, many challenges remain in developing therapies that exploit cell growth and tissue remodeling including (i) activating/inhibiting cell pathways synergistically, (ii) avoiding tumorigenesis, and (iii) ensuring appropriate physiological tissue function. These challenges are further exacerbated by the need to overcome ocular physiological barriers and clearance mechanisms. Here we present liposomes loaded with multiple mTOR pathway stimulating biologics designed to enhance neuroprotection after retina damage. Liposomes were loaded with ciliary neurotrophic factor, insulin-like growth factor 1, a lipopeptide N-fragment osteopontin mimic, and lipopeptide phosphatase tension homologue inhibitors for either the ATP domain or the c-terminal tail. In a mouse model of N-methyl-d-aspartic acid induced RGC death, a single intravitreal administration of liposomes reduced both RGC death and loss of retina electrophysiological function. Furthermore, combining liposomes with transplantation of induced pluripotent stem cell derived RGCs led to an improved electrophysiological outcome in mice. The results presented here show that liposomes carrying multiple signaling pathway modulators can facilitate neuroprotection and transplant electrophysiological outcome.

Abstract 5441: Regulation of AKT phosphorylation by GSK3β and PTEN to control chemoresistance in breast cancer

Abstract Background Chemotherapy is an important element in the treatment paradigm for breast cancers. However, the resistance of cancer cells to chemotherapeutic agents frequently results in the subsequent recurrence and metastasis. AKT phosphorylation is highly expressed or over-expressed in chemoresistant tumor samples. However, the precise molecular mechanism involved in AKT phosphorylation-related chemoresistance in breast cancer remains unknown. The aim of the present study was to assess whether the role of AKT phosphorylation in the cell viability and chemoresistance of breast cancer. Methodology/Principal Findings We developed two taxol resisted breast cancer cells: TAX Resis HepG2 and TAX Resis HepG2 SMMC7721. Western blot and immunofluorescence analysis indicated that glycogen synthase kinase 3 beta (GSK3β), phosphorylated phosphatase and tension homologue (p-PTEN) and phosphorylation of AKT (p-AKT) were highly expressed in taxol resisted HepG2 and SMMC7721 cells. The increase of GSK3β phosphorylated and inactivated PTEN, thereby enhanced phosphatidylinositide 3-kinases (PI3K)/Akt signaling. The increase in GSK3β, p-PTEN and p-AKT was associated with cell viability by MTT assay. Annexin-V-PI assay and transwell analysis were indicated that GSK3β knockdown with lentiviral shRNA (shRNA-GSK3β) promoted the apoptosis and suppressed the migration ability of Taxol resisted HepG2 and SMMC7721 cells, and both effects were reversed by activating p-AKT via PTEN inhibitor bpV(pic). Conclusions In conclusion, AKT phosphorylation manipulated by GSK3β and PTEN were correlated with cell viability, migration and apoptosis in Taxol resisted HepG2 and SMMC7721 cells, which may promote chemoresistance of breast cancer. Furthermore, functions of GSK3β can modulate cell viability via the PTEN/PI3K/Akt signaling pathway and induce chemoresistance, serving as a valuable molecular target for treatment of breast cancer. Citation Format: Chunyi Gao, Guohua Wang, Zhenglin Jiang. Regulation of AKT phosphorylation by GSK3β and PTEN to control chemoresistance in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5441.

MiR-150-3p targets SP1 and suppresses the growth of glioma cells.

Glioma has been considered as one of the most prevalent and common malignancy of the nervous system; however, the underlying mechanisms that are responsible for the occurrence and development of glioma still remain largely unknown. Amounting evidence highlights the critical regulatory function of miRNAs in carcinogenesis. Here, we showed that the expression of miR-150-3p was significantly decreased in glioma tissues and cell lines. Suppressed expression of miR-150-3p was associated with the lymph node metastasis of the glioma patients. Overexpression of miR-150-3p significantly inhibited the proliferation of glioma cells. Molecular study uncovered that the transcription factor specificity protein 1 (SP1) was identified as one of the targets of miR-150-3p. Highly expressed miR-150-3p in glioma cells significantly decreased both the mRNA and protein levels of SP1. Consistently, the abundance of phosphatase and tension homolog deleted on chromosome ten (PTEN), a negative downstream target of SP1, was increased with the ectopic miR-150-3p. Collectively, these results suggested that miR-150-3p suppressed the growth of glioma cells partially via regulating SP1 and possibly PTEN.

PTEN PDZ-binding domain suppresses mammary carcinogenesis in the MMTV-PyMT breast cancer model

Phosphatase and tension homolog (PTEN) is a potent tumor suppressor that possesses a PDZ-binding domain (PDZ-BD) at the end of its carboxyl terminus, whose functions during tumorigenesis remains unclear. Here, we crossed a mouse strain with germline deletion of PTEN PDZ-BD with MMTV-PyMT breast cancer model, and found that knockout (KO) mice display normal development of mammary glands, but have both increased breast tumorigenicity and lung metastasis. Orthotopic allograft experiments suggest the loss of PTEN PDZ-BD in breast cancer cells rather than in tumor microenvironment plays a prominent role in increasing tumor burden. Through RNA-sequencing, we observed a significant downregulation of myoepithelial marker genes in both KO primary breast cancer and orthotopic allografts. Moreover, these myoepithelial marker genes are significantly downregulated in human breast cancer tissues, and are associated with poorer clinical prognosis. In addition, several homeobox genes were also identified to be downreguated in KO breast cancer, whose expressions showed significant positive correlation with myoepithelial marker genes. Overall, our findings suggest a novel tumor suppressive role of PTEN PDZ-BD in a murine model of breast cancer, and the mechanism involves the dysregulation of homeobox genes which may result in defective myoepithelial differentiation in breast cancer cells.

Lipid Binding Preferences of the Alternatively Translated Region of PTEN-Long

PTEN-Long is a 576-amino acid translational variant of phosphatase and tension homolog on chromosome ten (PTEN), a tumor suppressor gene and antagonist to phosphoinositide-3-kinase (PI3K) signaling. PTEN-Long (PTEN-L) exhibits an alternative translation region (ATR) with an additional 173 N-terminal amino acids at the N-terminal end to the normal PTEN open reading frame. PTEN-L is secreted from cells, can exist outside the cell and shows activity towards PI(3,4,5)P3 after cell entry. Therefore, PTEN-L may have therapeutic uses by restoring a functional tumor suppressor protein to tumor cells. The mechanism by which PTEN-L enters cells is currently not understood. The ATR region of PTEN-L is evolutionary conserved and contains a polyarginine stretch with homology to cell permeable peptides (such as HIV TAT). This suggests that PTEN-L may be able to traverse the plasma membrane passively, but it hasn’t been proven. The N-terminal ATR part of PTEN-L is intrinsically disordered, which we confirmed using CD and FTIR spectroscopy. Our FTIR studies did not reveal any observable structural change of PTEN-L ATR upon lipid binding to PC, PS, PI and PI(4,5)P2 containing vesicles. However, we found that the integrity of model lipid bilayers composed of PS are compromised upon interaction with PTEN-L's ATR and we are further studying this with lipid leakage experiments. The lipid binding preferences of the ATR part of PTEN-L, as well as the full-length protein are being investigated using surface plasmon resonance (SPR). This study aims to gain insight on understanding PTEN-L's ATR membrane interactions at the molecular level.

MiR-106b promotes cell invasion and metastasis via PTEN mediated EMT in ESCC.

MicroRNA (miR)-106b serves an essential function in a variety of human cancer types, particularly in the process of invasion and metastasis. However, the function and mechanism of miR-106b in the invasion and metastasis of esophageal squamous cell carcinoma (ESCC) has remained elusive. In the present study, it was demonstrated that miR-106b was upregulated in ESCC tissues and cell lines. Furthermore, miR-106b expression in ESCC tissues was positively associated with lymphatic metastasis. Inhibition of miR-106b in EC-1 and EC9706 cells decreased not only the invasion and metastasis ability but also the proliferation ability of EC-1 and EC9706 cells. In addition, miR-106b had the ability to induce epithelial-to-mesenchymal transition (EMT) in EC-1 and EC9706 cells. In terms of the underlying mechanism, it was revealed that miR-106b promoted the invasion, metastasis and proliferation ability of EC-1 and EC9706 cells by directly targeting phosphatase and tension homolog (PTEN). Furthermore, miR-106b induced EMT in EC-1 and EC9706 cells by suppressing the expression of PTEN. In summary, the present study revealed that miR-106b contributed to invasion and metastasis in ESCC by regulating PTEN mediated EMT. Downregulation of miR-106b may be a novel strategy for preventing tumor invasion and metastasis.

Expression and clinical significance of serum MMP-7 and PTEN levels in patients with acute myeloid leukemia.

The aim of this study was to examine the changes of serum matrix metalloproteinase-7 (MMP-7) and phosphatase and tension homolog (PTEN) in patients with acute myeloid leukemia (AML) at different time points following treatment. The levels of serum MMP-7 and PTEN were measured from 80 AML patients with a diagnosis of peripheral blood, immune cell phenotype, and bone marrow puncture cytology examination. Among these, there were 20 cases of complete remission, 20 cases of primary untreated patients, 21 cases of incomplete remission, and 19 cases of relapse after remission. In addition, 20 healthy adults with normal physical examination results were enrolled as the control group. Patients were divided into different groups according to the treatment period. Serum MMP-7 and PTEN levels in patients and the healthy control group were measured using an ELISA. Compared with the control group, the levels of MMP-7 of 20 primary untreated patients were significantly increased (P<0.05), while there was no significant difference for the levels of PTEN in the incomplete remission group. A comparison between the control and complete remission groups revealed that the levels of MMP-7 and PTEN in the serum samples of 21 cases of patients with incomplete remission were significantly increased (P<0.05). In addition, the content of MMP-7 in 19 patients in relapse after remission group was significantly higher (P<0.05) than that of the complete remission and healthy control groups, while the levels of serum PTEN did not show significant changes. In conclusion, the level of serum MMP-7 and PTEN in AML patients was closely related to the clinical stage and the degree of disease. The combination of MMP-7 and PTEN may provide theoretical support for the accurate diagnosis, understanding of efficacy, prognosis and improvement of survival rate of AML.

Omega-3 Polyunsaturated Fatty Acids Time-Dependently Reduce Cell Viability and Oncogenic MicroRNA-21 Expression in Estrogen Receptor-Positive Breast Cancer Cells (MCF-7)

The omega-3 polyunsaturated fatty acid (n-3 PUFA), α-linolenic acid (ALA), and its metabolites, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), independently reduce the growth of breast cancer cells in vitro, but the mechanisms, which may involve microRNA (miRNA), are still unclear. The expression of the oncomiR, miR-21, is reduced by DHA treatment, but the effects of ALA on miR-21, alone or combined with EPA and DHA under physiologically relevant concentrations, have not been investigated. The effects of ALA alone and +/−EPA and DHA at the blood molar ratios seen in either humans (1.0:1.0:2.5, ALA:EPA:DHA) or mice (1.0:0.4:3.1, ALA:EPA:DHA) post flaxseed oil consumption (containing ALA) were assessed in vitro in MCF-7 breast cancer cells. Cell viability and the expression of miR-21 and its molecular target, phosphatase and tension homolog (PTEN, gene and protein), at different time points, were examined. At 1, 3, 48 and 96 h ALA alone and 24 h animal ratio treatments significantly reduced MCF-7 cell viability, while 1 and 3 h ALA alone and human and animal ratio treatments all significantly reduced miR-21 expression, and 24 h animal ratio treatment reduced miR-21 expression; these effects were not associated with changes in PTEN gene or protein expressions. We showed for the first time that ALA alone or combined with EPA and DHA at levels seen in human and animal blood post-ALA consumption can significantly reduce cell viability and modulate miR-21 expression in a time- and concentration-dependent manner, with the animal ratio containing higher DHA having a greater effect. The time dependency of miR-21 effects suggests the significance of considering time as a variable in miRNA studies, particularly of miR-21.

Benefit of everolimus as a monotherapy for a refractory breast cancer patient bearing multiple genetic mutations in the PI3K/AKT/mTOR signaling pathway.

A postmenopausal patient with a diagnosis of estrogen receptor (ER) (+), progesterone receptor (PR) (+), and human epidermal growth factor receptor-2 (HER2) (-) breast cancer was reported. The patient refused surgery and was resistant to conventional chemotherapy regimens. Computed tomography and the circulating tumor cell test indicated that the patient’s tumor burden increased rapidly even after several chemotherapy sessions. Multiple genetic aberrances in the phosphatidylinositol3-kinases (PI3K) signaling pathway were detected via next-generation sequencing (NGS)-based liquid biopsy, including a p. G1007R missense mutation in exon 21 of PIK3CA (33.61%), a p.L70fs frameshift mutation in exon 3 of phosphatase and tension homolog deleted on chromosome ten (PTEN) (49.14%), and a p. D1542Y missense mutation in exon 32 of mammalian target of rapamycin (mTOR) (1.66%). Therefore, only the mTOR inhibitor everolimus was administered to the patient. Partial remission (PR) was observed after 2 months, and sustained stable disease (SD) was observed after a year and a half. Subsequent sequencing showed that the mutation ratio of PIK3CA decreased to 4.17%, and that the PTEN and mTOR mutations disappeared, which revealed the significant curative effect of everolimus. We report the first case of successful monotherapy treatment using everolimus in a patient with advanced breast cancer bearing mutations in genes involved in the PI3K/ARK/mTOR signaling pathway. The success of this case highlights the invaluable clinical contribution of NGS-based liquid biopsy, as it successfully provided an optimal therapeutic target for the patient with advanced breast cancer.

Association of PTEN expression with biochemical recurrence in prostate cancer: results based on previous reports.

PurposeAmong men, prostate cancer (PCa) is one of the most commonly diagnosed cancers and the leading cause of cancer death worldwide. Phosphatase and tension homolog (PTEN) acts as a negative regulator of the phosphatidylinositol 3-kinase (PIK3)/Akt pathway and suppresses tumor progression. Meanwhile, PTEN is frequently deleted in PCa. Identifying the specific molecular markers of biochemical recurrence (BCR) in PCa patients is critical in clinical practice. Our systematic review summarizes the evidence about the PTEN expression and BCR rate in PCa patients.MethodsTo clarify the impact of PTEN expression on the PCa BCR rate, a systematic review and meta-analysis was performed by searching the PubMed, Embase, and Web of Science databases, to identify the relevant literature. The analysis of pooled data was performed with Stata 12. The combined odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were evaluated by the fixed-effects or random-effects models. The combined sensitivity and publication bias were also estimated.ResultsIn total, nine articles containing ten independent cohort studies, including 2,154 cases with positive expression of PTEN and 1,006 PTEN deletion cases, were deemed eligible for the meta-analysis. Overall, the positive expression of PTEN was associated with a significantly lower BCR rate (OR =0.521, 95% CI: 0.431–0.630). Subgroup analysis stratified by race revealed that in multiple races (OR =0.215, 95% CI: 0.072–0.648) and Caucasian (OR =0.469, 95% CI: 0.373–0.591) races, positive expression of PTEN showed a significant association with lower BCR rate. Subgroup analysis also showed the significant result in different sample sizes.ConclusionPTEN deletion has a relationship with a higher BCR rate in PCa compared with positive expression of PTEN.

Lack of relationship between PTEN 32-bp and TP53 16-bp Ins/Del polymorphisms and chronic hepatitis B virus infection.

TP53 and phosphate and tension homolog (PTEN) are two tumor suppressor genes that regulate cell proliferation, migration, and death. P53 and PTEN deficiency has been associated with hepatic fibrosis, a prominent pathological feature associated with chronic hepatitis B (CHB). The present study is aimed to assess the association of PTEN 32-bp Ins/Del (rs34421660) and TP53 16-bp Ins/Del polymorphisms with CHB infection susceptibility. A total of 411 subjects were recruited in this case-control study of 213 patients with CHB infection and 198 healthy individuals as controls. PTEN and TP53 deletions were detected by polymerase chain reaction method. We found no significant association between PTEN 32-bp Ins/Del polymorphism and the risk for CHB using either of codominant (Ins/Del vs. Ins/Ins: P=0.427; Del/Del vs. Ins/Ins: P=0.235), dominant (Ins/Del+Del/Del vs. Ins/Ins P=0.343) or recessive genetic model (Del/Del vs. Ins/Ins+Ins/Del: P=0.516). At allelic level although the PTEN Del variant allele was more common in CHB patients compared to controls (55 vs. 51), but the difference did not reach the statistical significant range (OR 0.87, P=0.327). Similarly, no association was observed between TP53 16-bp Ins/Del and the risk for CHB infection at both genotype and allele levels (P>0.05). In summary, our study demonstrated that the PTEN 32-bp and TP53 16-bp Ins/Del polymorphisms did not affect the risk of CHB infection in the Iranian population.