PTEN Protein Research Articles

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

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. 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. 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). 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.

Replication Study: A coding-independent function of gene and pseudogene mRNAs regulates tumour biology

As part of the Reproducibility Project: Cancer Biology we published a Registered Report (Khan et al., 2015), that described how we intended to replicate selected experiments from the paper "A coding-independent function of gene and pseudogene mRNAs regulates tumour biology" (Poliseno et al., 2010). Here we report the results. We found PTEN depletion in the prostate cancer cell line DU145 did not detectably impact expression of the corresponding pseudogene PTENP1. Similarly, depletion of PTENP1 did not impact PTEN mRNA levels. The original study reported PTEN or PTENP1 depletion statistically reduced the corresponding pseudogene or gene (Figure 2G; Poliseno et al., 2010). PTEN and/or PTENP1 depletion in DU145 cells decreased PTEN protein expression, which was similar to the original study (Figure 2H; Poliseno et al., 2010). Further, depletion of PTEN and/or PTENP1 increased DU145 proliferation compared to non-targeting siRNA, which was in the same direction as the original study (Figure 2F; Poliseno et al., 2010), but not statistically significant. We found PTEN 3'UTR overexpression in DU145 cells did not impact PTENP1 expression, while the original study reported PTEN 3'UTR increased PTENP1 levels (Figure 4A; Poliseno et al., 2010). Overexpression of PTEN 3'UTR also statistically decreased DU145 proliferation compared to controls, which was similar to the findings reported in the original study (Figure 4A; Poliseno et al., 2010). Differences between the original study and this replication attempt, such as level of knockdown efficiency and cellular confluence, are factors that might have influenced the results. Finally, where possible, we report meta-analyses for each result.

Overexpression of PTEN regulated by miR-19b and miR-494 in the villous of recurrent spontaneous abortion patients

Recurrent spontaneous abortion (RSA) can be attributed to multiple factors, and abnormal invasion and apoptosis of trophoblast cells have attracted extensive attention. Our study aimed to investigate the expression of PTEN and miRNAs with potential regulatory relationships in the placental villi of RSA patients. Nineteen RSA patients and sixteen healthy women at reproductive age undergoing induced abortion (IA) were enrolled in the present study. The expression of PTEN and miRNAs were investigated using real-time polymerase chain reaction (PCR) and Western blotting, further verification between PTEN and potential miRNAs used cell culture and transfection, and luciferase activity assays were used to determine whether PTEN is directly regulated by potential miRNA. The results indicated that both PTEN mRNA and protein expression levels were upregulated in RSA patients, but a significant difference was only observed in protein expression level (p < 0.001). Through real-time PCR pre-scanning, the results of nine potential miRNAs revealed three significantly upregulated miRNAs (miR-494, miR-146a, and miR-21) and one significantly downregulated miRNA (miR-19b). The results of further verification regarding miR-19b and miR-494 suggested that upregulated miR-19b, cooperating with downregulated miRNA-494, could inhibit PTEN expression. In conclusion, the findings suggest that the overexpression of PTEN plays an important role in the pathogenesis of RSA, with miR-19b directly regulating PTEN and working with miR-494, all of which participating in abnormal effects of villous’ trophoblastic cell may be a critical event.

Co-delivery of AKT3 siRNA and PTEN Plasmid by Antioxidant Nanoliposomes for Enhanced Antiproliferation of Prostate Cancer Cells.

Globally, prostate cancer is the fifth major cancer type and the second leading cause of cancer-related death in men. In 2018, about 1.3 million prostate cancer cases were reported worldwide. It is reported that loss of PTEN (tumor suppressor gene) expression leads to hyperactivation of the PI3K/AKT pathway and thus induces uncontrolled cell proliferation. Loss or mutation in regular PTEN expression is reported to occur in ∼30% of primary prostate cancer cases and ∼65% of metastatic cancer cases. Restoring the PTEN expression could inhibit the PI3K/AKT/mTOR signaling pathway, thus avoid the growth of prostate cancer cells. In this work, we have synthesized a multifunctional nanoliposomal formulation incorporating PTEN plasmid, AKT3 siRNA, and antioxidant cerium oxide nanoparticles (CeNPs). The nanoliposomes were able to successfully internalize in prostate cancer (PC-3) cells, restore the expression of PTEN protein, and knock down AKT3 mRNA. Further, the multifunctional nanoliposomes induce DNA damage and apoptosis in prostate cancer cells. The investigation of the PI3K/AKT/mTOR signaling pathway revealed that PTEN protein and apoptosis-specific proteins are overexpressed, leading to the inhibition of oncoproteins and, thus, prostate cancer.

Ferulic Acid Ameliorates Lipopolysaccharide-Induced Barrier Dysfunction via MicroRNA-200c-3p-Mediated Activation of PI3K/AKT Pathway in Caco-2 Cells.

Intestinal barrier dysfunction is an important clinical problem in various acute and chronic pathological conditions. Ferulic acid (FA) can attenuate the intestinal epithelial barrier dysfunction, however, the underlying mechanism remains unclear. The present study aimed to uncover the protective effect of FA on intestinal epithelial barrier dysfunction in a Caco-2 cell model of lipopolysaccharide (LPS) stimulation and the underlying mechanism. Caco-2 cells were pretreated with FA and then exposed to LPS stimulation. The barrier function of Caco-2 cells was evaluated by measuring trans-epithelial resistance (TER) and 4-kDa fluorescein isothiocyanate (FITC)-dextran (FD4) flux, and analyzing the tight junction protein expression and structure. The results showed that decreased TER and increased FITC-FD4 flux were observed in Caco-2 cells stimulated with LPS, but these effects were attenuated by FA pretreatment. FA pretreatment inhibited LPS-induced decrease in occludin and ZO-1 mRNA and protein expression. LPS stimulation decreased miR-200c-3p expression, whereas this decrease was inhibited by FA pretreatment. Furthermore, overexpression of miR-200c-3p strengthened the protective effects of FA on LPS-induced Caco-2 cell barrier dysfunction by decreasing epithelial permeability, increasing occludin and ZO-1 protein expression, and maintaining of ZO-1 protein distribution, while suppression of miR-200c-3p reversed the protective effects of FA. LPS treatment increased the expression of PTEN protein and decreased expression of phosphorylated PI3K and AKT proteins. However, pretreatment of FA inhibited expression of PTEN protein and promoted activation of PI3K/AKT signaling pathway in the LPS-treated Caco-2 cells, and this regulatory effect of FA on the PTEN/PI3K/AKT signaling pathway was strengthened or weakened by miR-200c-3p overexpression or suppression, respectively. Our findings suggested that in Caco-2 cells, FA promotes activation of PI3K/AKT pathway by miR-200c-3p-mediated suppression of the negative mediator PTEN, which, in turn, maintains TJ function and thus ameliorates LPS-induced intestinal epithelial barrier dysfunction.

The expression change of OTUD3-PTEN signaling axis in glioma cells.

BackgroundOTU domain-containing protein 3 (OTUD3), as a deubiquitinase (DUB) belonging to the ovarian tumor protease (OTU) family, has been reported to suppress tumor via OTUD3-PTEN signaling axis. Glioma is the most common primary intracranial tumor with high invasiveness and poor prognosis. Although less than half of the patients have phosphatase and tension homologue deleted in chromosome 10 (PTEN) mutations or homozygous deletions, two-thirds of glioma possess diminished PTEN expression. Hence, it is conceivable that other obscure mechanisms may cause the decreased expression of the PTEN protein.MethodsOTUD3 expression was assessed in human normal and glioma tissues at The Cancer Genome Atlas (TCGA) database (https://www.cancer.gov/) and Genotype-Tissue Expression (GTEx) database (https://commonfund.nih.gov/GTex). The mRNA levels of OTUD3 in C6 cells and primary astrocytes were detected using real-time fluorescence quantitative PCR. Western blot was performed to assay PTEN and OTUD3 protein expression in C6 cells and primary astrocytes. By generating Kaplan-Meier curves, we predicted the association between OTUD3 expression and prognosis in glioma patients.Results(I) OTUD3 transcription was markedly downregulated in glioma based on microarray data for gene expression between human gliomas and normal brain samples. (II) The mRNA levels of OTUD3 in C6 cells was significantly lower than that of in primary astrocytes. (III) The expressions of protein PTEN and OTUD3 in C6 cells were significantly decreased when compared with primary astrocytes. (IV) Glioma patients with high expression of OTUD3 had a longer survival time than patients with low expression.ConclusionsOur present findings demonstrated that low expression of OTUD3 in glioma may be involved in PTEN related glioma and may contribute to patient survival.

Effect of Bmi-1 Silencing on the Proliferation of K562/ADM Cells in vitro and in vivo

To investigate the effect of Bmi-1 gene silencing on the proliferation of K562/ADM cells in vitro and in vivo and to explore its possible molecular mechanism. The small interference RNA (siRNA) sequences of Bmi-1 were transfected into K562/ADM cells for decreasing the expression of Bmi-1. The effect of Bmi-1 silencing on the proliferation of K562/ADM cells in vitro and in vivo was detected by using MTT method, cell colony-forming test and tumoriganicity of nude mice; the expression of Bmi-1, PTEN and PAKT proteins was detected by Wertern blot. The immunohistochemistry assay was used to analyze the expression of Bmi-1 and Ki-67. The Bmi-1 silencing could significantly inhibit the proliferation activity of K562/ADM cells, the cell colony-forming ability and tumorigenicity were reduced. LY294002 decreased p-AKT expression, cell colony-forming ability and tumorigenicity. Bpv reduced the PTEN expression but increased p-AKT expression and restored the colony-forming ability and tumorigenesis of K562/ADM-S1-Bpv cells. Bmi-1-siRNA dramatically suppressed the Bmi-1 and Ki-67 protein levels in xenograft tumor tissue. Bmi-1 can mediate the proliferation of K562/ADM cell, the PTEN/p-AKT might be involved in this pathway.

MiR-29b-3p Reverses Cisplatin Resistance by Targeting COL1A1 in Non-Small-Cell Lung Cancer A549/DDP Cells.

ObjectiveTo investigate the expression of miR-29b-3p in tissues and cells of non-small-cell lung cancer (NSCLC) and its effect on cisplatin resistance in NSCLC cells and its mechanism.MethodsThe mRNA expression of miR-29b-3p and COL1A1 in NSCLC tissue, cell line A549 and cisplatin-resistant cell line A549/DDP was detected by RT-qPCR. MiR-29b-3p Mimics was transfected into A549/DDP cells, and the cell viability, proliferation, apoptosis and related protein expression were detected by CCK-8, flow cytometry and Western blot. Also, luciferase reporter gene assay was used to verify the targeting relationship between miR-29b-3p and COL1A1. Moreover, COL1A1 overexpression lentivirus and miR-29b-3p mimics (Mimics+COL1A1) were simultaneously transfected into A549/DDP cells, and then the cell viability and related protein expression were measured.ResultsIn NSCLC tissue and its cell line, miR-29b-3p was downregulated and COL1A1 was upregulated (P<0.05). After A549/DDP cell was transfected by mimics, its cell viability and proliferation rate decreased, apoptosis rate and the expression of tumor suppressor gene PTEN and apoptosis-related protein BAX were increased (P<0.05), which could be reversed by Mimics+COL1A1 co-transfection. Luciferase reporter gene assay indicated that COL1A1 was the target gene of miR-29b-3p.ConclusionAll in all, miR-29b-3p can reverse the cisplatin resistance of A549/DDP cells by inhibiting the expression of COL1A1 gene and increasing the expression of PTEN and BAX.

PTEN activation contributes to neuronal and synaptic engulfment by microglia in tauopathy

Phosphatase and tensin homolog (PTEN) regulates synaptic density in development; however, whether PTEN also regulates synapse loss in a neurodegenerative disorder such as frontotemporal lobar degeneration with Tau deposition (FTLD-Tau) has not been explored. Here, we found that pathological Tau promotes early activation of PTEN, which precedes apoptotic caspase-3 cleavage in the rTg4510 mouse model of FTLD-Tau. We further demonstrate increased synaptic and neuronal exposure of the apoptotic signal phosphatidylserine that tags neuronal structures for microglial uptake, thereby linking PTEN activation to synaptic and neuronal structure elimination. By applying pharmacological inhibition of PTEN's protein phosphatase activity, we observed that microglial uptake can be decreased in Tau transgenic mice. Finally, we reveal a dichotomous relationship between PTEN activation and age in FTLD-Tau patients and healthy controls. Together, our findings suggest that in tauopathy, PTEN has a role in the synaptotoxicity of pathological Tau and promotes microglial removal of affected neuronal structures.

The importance of preexisting drug resistance due to overexpression of P-glycoprotein for the formation of resistance to bortezomib

Objective of the study. In our work we investigated the effect of pre-existing drug resistance by the mechanism of activation of ABC transporters – P-glycoprotein (Pgp) overexpression – on the development of resistance to the proteasome inhibitor bortezomib.Materials and methods. Cultures RPMI8226 and K562 / i-S9 (with Pgp overexpression) and their bortezomib-resistant sublines RPMI8226 / btz-6 and K562 / i-S9vlc were used as models. The methods used were MTT test, flow cytometry, Western blot and real-time polymerase chain reaction using the Human Signal Transduction Pathway Finder system.Results. The expression of the main PI3K-AKT and NF-κB signaling pathways did not change in RPMI8226 / btz-6 subline cells. However, AKT kinase expression was significantly increased and PTEN protein expression was reduced in K562 / i-S9vlc cells with Pgp-overexpression. Significant changes in gene expression (42 %) were found in RPMI8226 / btz-6 cells related to a number of main signaling pathways in the tumor cell, namely: activation of 3–4 genes in signaling pathways related to hypoxia, oxidative stress, PPAR and p53. The highest activation in these cells was found in the TGFβ signaling pathway. In resistant K562 / i-S9vlc cells, expression of only 5 genes (10 %) increased: Fas, HMOX1, CPT2, ICAM, and SOCS3. Three genes were also identified that changed in both resistant sublines: Fas, HMOX1 and CPT2. Further, we showed that in the RPMI8226 / btz-6 subline, along with changes in the expression of signal transduction genes, there is a large pool of CD138-negative cells, and in the K562 / i-S9vlc subline, the number of cells expressing CD34 increases and the number of CD13 decreases.Conclusion. We found that different signaling pathways are involved in the formation of resistance to bortezomib in the absence of Pgp expression and its overexpression. In addition, a cell line without activated resistance pathways requires more extensive rearrangements in the signal system to acquire resistance to bortezomib. However, in both cases, bortezomib leads to a change in the immunophenotype of the cells – to the appearance of dedifferentiated subpopulations.

Role of miR-92a-3p/PTEN axis in regulation of pancreatic cancer cell proliferation and metastasis.

To explore the effect of miR-92a-3p on the proliferation and metastasis of pancreatic cancer cells via targeting phosphatase and tension homolog deleted on chromosome ten (PTEN). MiR-92a-3p expression and PTEN protein levels were quantified in a normal pancreatic cells (HPDE6-C7) and 5 pancreatic cancer cell lines (Panc-1, BxPC-3, AsPC-1,MIA Paca-2, and Capan-2) by real-time PCR and Western blotting, respectively. BxPC-3 and Panc-1 cells were selected for further experiment. After transfection of normal control (NC) mimics (NC mimics group), miR-92a-3p mimics (miR-92a-3p mimics group), NC inhibitor or miR-92a-3p inhibitor (NC inhibitor group or miR-92a-3p inhibitor group), the proliferation of BxPC-3 and Panc-1 cells was measured by cell counting kit-8 (CCK-8), and the migration of them was measured by Transwell assay, and the levels of PTEN protein were measured by Western blotting. In addition, wild-type PTEN 3'-UTR (wt-PTEN 3'UTR) and mutant-type PTEN 3'-UTR (mut-PTEN 3'UTR) luciferase reporter vectors were constructed and co-transfected with NC mimics, miR-92a-3p mimic, NC inhibitor or miR-92a-3p inhibitor into 293T tool cells, and then the dual luciferase reporter assay was performed to examine the regulative correlation between miR-92a-3p and PTEN. The BxPC-3 cells were divided into 4 groups: a NC inhibitor+si-NC group, a miR-92a-3p inhibitor+si-NC group, a NC inhibitor+si-PTEN group, and a miR-92a-3p inhibitor+si-PTEN group. The Panc-1 cells were also assigned into 4 groups: a NC mimics+NC group, a miR-92a-3p mimics+si-NC group, a NC mimics+ PTEN group, and a miR-92a-3p mimics+PTEN group. The proliferation of Panc-1 cells was measured by CCK-8; the cell migration was measured by Transwell assay, and the levels of PTEN protein were measured by Western blotting. The miR-92a-3p was highly expressed in pancreatic cancer cell lines (allP<0.01), while the PTEN protein levels were lower in pancreatic cancer cell lines (allP<0.05)compared with that in the HPDE6-C7 cells. Compared with the NC mimics group, the cell viability of BxPC-3 and Panc-1 cells were both increased in the miR-92a-3p mimics group (bothP<0.01); compared with the inhibitor group, the cell viability of BxPC-3 and Panc-1 cells were both decreased in the miR-92a-3p inhibitor group (bothP<0.01). Compared with the NC mimics group, the cell number of BxPC-3 and Panc-1 cells through micropores were increased in the miR-92a-3p mimics group (bothP<0.01); compared with the inhibitor group, the cell number of BxPC-3 and Panc-1 cells through micropores were decreased in the miR-92a-3p inhibitor group (bothP<0.01). Compared with NC mimics group, the activity of dual luciferaseof wt-PTEN3'-UTR was inhibited in the miR-92a-3p mimics group (P<0.01); compared with the NC inhibitor group, the activity of dual luciferase of wt-PTEN3'-UTR was promoted in the miR-92a-3p inhibitor group (P<0.01). Compared with the miR-92a-3p inhibitor+si-NC group, the suppressive effects of miR-92a-3p on the proliferation and metastasis of BxPC-3 cells was restored in the miR-92a-3p inhibitor+si-PTEN group; while compared with the miR-92a-3p mimics+NC group, the positive effects of miR-92a-3p overexpression on the proliferation and metastasis of Panc-1 cells was restored in the miR-92a-3p mimics+PTEN group. The highly expressed miR-92a-3p in pancreatic cancer cells can decrease the protein levels of PTEN, thereby enhancing the proliferation and metastasis activity of pancreatic cancer cells.

Analysis of DNA methylation patterns in the tumor immune microenvironment of metastatic melanoma.

The presence of immune cells in the tumor microenvironment has been associated with response to immunotherapies across several cancer types, including melanoma. Despite its therapeutic relevance, characterization of the melanoma immune microenvironments remains insufficiently explored. To distinguish the immune microenvironment in a cohort of 180 metastatic melanoma clinical specimens, we developed a method using promoter CpG methylation of immune cell type‐specific genes extracted from genome‐wide methylation arrays. Unsupervised clustering identified three immune methylation clusters with varying levels of immune CpG methylation that are related to patient survival. Matching protein and gene expression data further corroborated the identified epigenetic characterization. Exploration of the possible immune exclusion mechanisms at play revealed likely dependency on MITF protein level and PTEN loss‐of‐function events for melanomas unresponsive to immunotherapies (immune‐low). To understand whether melanoma tumors resemble other solid tumors in terms of immune methylation characteristics, we explored 15 different solid tumor cohorts from TCGA. Low‐dimensional projection based on immune cell type‐specific methylation revealed grouping of the solid tumors in line with melanoma immune methylation clusters rather than tumor types. Association of survival outcome with immune cell type‐specific methylation differed across tumor and cell types. However, in melanomas immune cell type‐specific methylation was associated with inferior patient survival. Exploration of the immune methylation patterns in a pan‐cancer context suggested that specific immune microenvironments might occur across the cancer spectrum. Together, our findings underscore the existence of diverse immune microenvironments, which may be informative for future immunotherapeutic applications.

PTEN Loss and Cyclin A2 Upregulation Define a PI3K/AKT Pathway Activation in Helicobacter pylori-induced MALT and DLBCL Gastric Lymphoma With Features of MALT.

Helicobacter pylori infection is strongly associated with primary gastric diseases, such as extranodal mucosa-associated lymphoid tissue (MALT) lymphoma, diffuse large B-cell lymphoma (DLBCL) with histologic evidence of MALT origin, and gastric carcinoma. The cytotoxin-associated gene A (CagA) protein behaves as a bacterial oncoprotein, promoting tumorigenesis via dysregulation of the phosphatidylinositol 3-kinase/AKT pathway (PI3K/AKT). We investigated the molecular mechanisms of PI3K/AKT pathway dysregulation in H. pylori-induced MALT and DLBCL gastric lymphoma. Immunohistochemical assays for CagA, phospho(p)-S473-AKT, PTEN, SHIP, and cyclin A2 proteins were performed on samples from 23 patients with H. pylori-positive MALT lymphoma and 16 patients with H. pylori-positive gastric DLBCL. We showed that CagA localization is correlated with the activation of the AKT pathway in both MALT and DLBCL lymphoma cells. Interestingly, we found a close association between the loss of PTEN, the overexpression of cyclin A2, and the phosphorylation of AKT in gastric MALT and DLBCL tumor cells.

MicroRNA-21 may be involved in the therapeutic effects of Galla chinensis ointment on keloid.

ObjectiveGalla chinensis ointment can inhibit the proliferation of keloid fibroblasts and decrease keloid formation. We investigated whether Galla chinensis ointment inhibits keloid fibroblast proliferation through expression of microRNA-21, phosphorylated (p)-phosphatidylinositol 3-kinase (p-PI3K), chromosome 10 neutropenic protein phosphatase (PTEN), protein kinase B (p-Akt), and mammalian target of rapamycin (p-mTOR).MethodsA keloid mouse model and human keloid-derived fibroblasts were developed and treated with Galla chinensis. Immunohistochemistry, western blot, and reverse transcription-PCR were used to detect miR-21, PI3K, PTEN, Akt, and mTOR in keloid tissues.Resultsp-Akt and p-mTOR were highly expressed in the control group, PTEN was highly expressed in the treatment group, and p-PI3K was highly expressed in keloid tissue in both groups. Galla chinensis reduced miR-21 expression and increased PTEN mRNA expression in keloid fibroblasts compared with the control group, resulting in increased PTEN protein and decreased p-Akt and p-mTOR protein. Galla chinensis had no effect on p-PI3K.ConclusionGalla chinensis might inhibit proliferation of keloid fibroblasts by upregulating PTEN, thus inhibiting expression of miR-21 and downregulating p-Akt and p-mTOR expression. These results confirm the effect of Galla chinensis ointment on fibroblasts and suggest that it could be used to manage keloids clinically.

The effect of miRNA-34a antisense oligonucleotide on non-small cell lung cancer cell line HCC827

Objective To investigate the effect of antisense oligonucleotides of miRNA-34a on non-small cell lung cancer (NSCLC) and its molecular mechanism. Methods The expression of miRNA-34a in human non-small cell lung cancer cell line HCC827 and human normal lung cell MRC-5 was detected by real time fluorescence quantitative polymerase chain reaction (qRT-PCR). HCC827 cells were divided into three groups: blank control group, negative control group, anti-sense oligonucleotide group(liposome 2000 transfected anti-sense oligonucleotide miRNA-34a); cell counting kit-8 (CCK-8) method was used to detect cell proliferation, Jimsa staining was used to detect cell cloning ability, Transwell test was used to detect cell migration and invasion ability; RT-PCR and Western blot were used to detect phosphatase and tensin homolog (PTEN), phosphorylation-protein kinase B (p-Akt), phosphatidylinositol-3-kinase (PI3K) mRNA and protein expression. Results The relative expression of miRNA34a in HCC827 cells was significantly higher than that in human normal lung cells (P 0.05). At 48 h, 72 h and 96 h, the proliferation level of HCC827 cells in anti-sense oligonucleotide miRNA-34a group was significantly lower than that in negative control group and blank control group (P<0.05). The cell cloning rate of antisense oligonucleotide miRNA-34a group was significantly lower than that of negative control group and blank control group (P<0.01). The number of migration and invasion of HCC827 cells in antisense oligonucleotide RNA-34a group was significantly lower than that in negative control group and blank control group (P<0.01). The relative expression of PTEN mRNA and protein in antisense oligonucleotide miRNA-34a group was significantly higher than that in negative control group and blank control group (P<0.05); the relative expression of p-Akt, PI3K mRNA and protein in antisense oligonucleotide miRNA-34a group were significantly lower than that in negative control group and blank control group (P<0.05). Conclusions The expression level of miRNA-34a in human non-small cell lung cancer cells is significantly higher than that in human normal lung cells. Antisense oligonucleotides of miRNA-34a can inhibit the proliferation, cloning, migration and invasion of human non-small cell lung cancer cells. The mechanism may be related to the negative regulation of PTEN/p-Akt/PI3K signaling pathway. Key words: Oligonucleotides, antisense; miRNA-34a; Carcinoma, non-small-cell lung; Cell line, tumor

Study on the mechanism of inhibiting invasion of human laryngeal squamous cell carcinoma Hep-2 and TU212 cells after the downregulation of miRNA-106b

Objective To investigate the effect of miRNA-106b (miR-106b) on human laryngeal squamous cell carcinoma Hep-2 and TU212 cells and its mechanism. Methods Hep-2 and TU212 cells were divided into miR-106b inhibitory sequence transfected group (the experimental group), miR-106b competitive negative sequence transfected group (the negative control group) and non-intervention group (the blank group). The inhibitory effect of miR-106b inhibitory sequence on the expression of miR-106b was verified by using reverse transcription quantitative polymerase chain reaction (qRT-PCR). Whether phosphatase and tensin homolog (PTEN) was the target gene of miR-106b was analyzed by using bioinformatics and luciferase report vector. PTEN small interfering RNA (siRNA) was used to inhibit the expression of PTEN in Hep-2 and TU212 cells. Transwell method and Western blot were used to detect the change of invasion ability of Hep-2 and TU212 cells after miR-106b silencing or the PTEN intervening, and the expression change of PTEN, epithelial cadherin and vimentin. Results The relative expression levels of miR-106b in Hep-2 and TU212 cells in the experimental group were 0.110 ± 0.037 and 0.074 ± 0.009, respectively, which were lower than those in the negative control group (1.013±0.059 and 1.035±0.062, respectively; all P < 0.05). In Transwell experiments, the number of invasive cells in each field of Hep-2 and TU212 cells in the experimental group was less than that in the negative control group [(37.09±4.02) vs. (95.65±4.77), (29.16±2.49) vs. (103.19±6.08), all P < 0.05]. The bioinformatics analysis results showed that 3'-UTR region of PTEN mRNA was complementary to 3'-UTR region of miR-106b. Dual-luciferase reporter system analysis showed that the luciferase reporter activity of wild-type PTEN gene transfected with miR-106b was decreased to (22.84±2.68)%, and that of mutant PTEN gene transfected with miR-106b was almost unchanged [(92.08±3.44)%], and the difference was statistically significant (P < 0.001). The expression level of PTEN protein of Hep-2 and TU212 cells in the experimental group was higher than that in the negative control group. Transwell method showed that the number of invasive cells in each field of Hep-2 and TU212 cells in the experimental group with the inhibition of PTEN expression was more than that in the experimental group without the inhibition of PTEN expression [(65.08±3.57) vs. (26.72±2.58), (57.38±4.96) vs. (31.81±2.97), all P < 0.05]. Western blot showed that the expression level of epithelial-cadherin was up-regulated and vimentin was down-regulated of Hep-2 and TU212 cells in the experimental group with the inhibition of PTEN expression. Conclusions The human laryngeal squamous cell carcinoma Hep-2 and TU212 cell miR-106b can influence the downstream invasion-related protein of PTEN and change the cell invasion ability through the targeted regulation of PTEN expression. Key words: Laryngeal neoplasms; Carcinoma, squamous cell; Neoplasm invasiveness; RNA interference; miRNA-106b; Phosphatase and tensin homolog

Epigenetically silenced LINC02381 functions as a tumor suppressor by regulating PI3K-Akt signaling pathway

Recent advances have revealed that lncRNAs play important roles in tumorigenesis. However, only a small number of functional lncRNAs have been well characterized, particularly in colorectal cancer. Therefore, more extensive studies are needed to identify and characterize these lncRNAs to better understand cancer progression. In the present study, using available RNA-seq data, we found that LINC02381 (NR_026656.1) differentially expresses in CRC tissues compared to normal pairs. Consistently, RT-qPCR results showed that LINC02381 was down regulated in CRC tissues and also in different cancerous cell lines. CRC cells treatment with de-methylating and chemotherapy agents indicated that DNA methylation of LINC02381 may be responsible for the transcriptional silencing of LINC02381 in colorectal cancer cells. Then, the functional changes of the cells in response to LINC02381 alteration were assessed and the data indicated that LINC02381 up-regulation suppressed cell viability and proliferation while increasing the apoptosis in CRC-originated cell lines. Mechanistically, LINC02381 overexpression was increased PTEN protein levels but decreased phospho-Akt levels. Finally, we proposed a hypothesized model for PI3K signaling regulation by LINC02381. Altogether, the result of this study suggests that LINC02381 might have suppressive effects on human colorectal cancer tumorigenesis partly by regulating PI3K signaling pathway.

Deep learning-based approach for automated assessment of PTEN status.

294 Background: PTEN loss is associated with adverse outcomes in prostate cancer and has the potential to be clinically implemented as a prognostic biomarker. Deep learning algorithms applied to digital pathology can provide automated and objective assessment of biomarkers. The objective of this work was to develop an artificial intelligence (AI) system for automated detection and localization of PTEN loss in prostate cancer samples. Methods: Immunohistochemistry (IHC) was used to measure PTEN protein levels on prostate tissue microarrays (TMA) from two institutions (in-house n=272 and external n=125 patients). TMA cores were visually scored for PTEN loss by pathologists and, if present, spatially annotated. In-house cohort (N=1239 cores) were divided into 70/20/10 training/validation/testing sets. Two algorithms were developed: a) Class I=core-based, to label each core for biomarker status and b) Class II=pixel-based, to spatially distinguish areas of PTEN loss within each core. ResNet101 architecture was used to train a multi-resolution ensemble of classifiers at 5x, 10x, and 20x for Class I task and a single classifier at simulated 40x for Class II segmentation. Results: For Class I algorithm, accuracy of PTEN status was 88.3% and 93.4% in validation and testing cohorts, respectively (Table). AI-based probability of PTEN loss was higher in cores with complete loss vs partial loss. Accuracy was improved to 90.7% in validation and 93.5% in test cohorts using the Class II region-based algorithm, with median dice scores 0.833 and 0.831, respectively. Direct application to external set demonstrated a high false positive rate. Loading trained model and conservatively re-training (“fine-tuning”) on 48/320 external cohort cores improved accuracy to 93.4%. Conclusions: Results demonstrate feasibility and robustness for fully automated detection and localization of PTEN loss in prostate cancer tissue samples and possibility for time/cost-effectiveness of sample processing/scoring in research and clinical laboratories.[Table: see text]

Abstract P1-09-08: Development and characterization of PTEN IHC assay for testing breast cancer patients specimens

Abstract Background: Phosphatase and tensin homolog (PTEN) is a tumor suppressor gene that is a major negative regulator of the Phosphatidylinositol 3-kinase (PI3K) pathway. Loss of PTEN protein expression has been mechanistically linked to tumor progression. Blocking the PI3K pathway might inhibit the growth and proliferation of cells that have deletions in PTEN. Thus characterization of PTEN expression in patient tumor samples may assist prediction of potential response to PI3K inhibitor therapies. Methods: We developed and validated an immunohistochemical assay on Ventana BenchMark XT to detect PTEN in formalin fixed and paraffin-embedded (FFPE) tissue by utilizing a rabbit monoclonal antibody (clone 138G6) from Cell Signaling Technologies that recognizes the carboxy-terminal domain of PTEN. PTEN immunohistochemical staining was performed on 1577 breast tumor specimens to determine PTEN protein loss. A subset of these cases (n=663) was also assessed for PTEN mutation. Results: Cellular localization of PTEN expression was observed in both the cytoplasm and the nucleus. Both cellular compartments were scored and used in the staining intensity determination. We observed that PTEN staining is sensitive to variation in tissue handling, fixation and antigen retrieval. PTEN staining was affected significantly by antigen retrieval method. Optimal staining conditions were determined to be 1:60 antibody dilution using Citrate pH 6.0 as antigen retrieval buffer. In a cohort of 1577 hormone receptor positive HER2-negative locally advanced or metastatic breast cancer patients, loss of PTEN protein was observed in 8.6% (135/1577) of patients. There was a positive correlation between PTEN mutation rate (17 out of 66 PTEN IHC positive cases vs 14 out of 587 negative cases) and loss of PTEN protein expression. PTEN loss was observed to correlate with better clinical response to PI3K inhibitor. Conclusions: Pre-analytical handling of samples is important for PTEN IHC staining. PTEN mutations and insertions/deletions contribute to PTEN protein loss. This study validates a simple method to interrogate PTEN status in clinical specimens and supports the utility of this test in selecting patients who are likely to respond to PI3K inhibitor treatment. Citation Format: Hua Gong, Emmanuel Pacia, Sharmila Manjeshwar, Beiru Chen, Xun Li, Bashar Dabbas, Jelveh Lameh, Naveen Babbar, Shabnam Tangri. Development and characterization of PTEN IHC assay for testing breast cancer patients specimens [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-09-08.

Abstract P5-01-20: Blood-based detection of PTEN loss and pathway alterations for personalized treatment of breast cancer

Abstract Introduction: Loss of function of the PTEN tumour suppressor, which leads to elevated PI3K/Akt pathway activation, is one of the common events in breast cancer. Although the mechanisms of PTEN loss of function are diverse, the most frequently observed events are PTEN gene deletion or mutation, resulting in little or no PTEN protein expression measured by tissue-based immunohistochemical staining. Tissue-based immunostaining or genetic analysis could be challenging due to its invasive nature, whereas a robust assay for blood-based detection of copy number loss has been lacking. The aim of this pilot study was to explore the pattern of genetic alterations of PTEN and its downstream PI3K-AKT pathways in breast cancer using a minimally-invasive, blood-based next generation sequencing (NGS) technology. Methods: Plasma samples were prepared from a cohort of 244 breast cancer (BC) samples of all stages. Cell-free DNA (cfDNA) was extracted from plasma sample and further analyzed using the PredicinePLUS™ NGS 180-gene panel. Specifically, cfDNA was enriched for targeted regions using a hybridization-based protocol, and sequenced using Illumina sequencer. Mutational profiling was analyzed using Predicine’s proprietary DeepSea bioinformatics platform with focus on coding exonic regions of genes of interests in PTEN, PI3K and AKT pathway. Results: cfDNA-based PTEN copy number loss was detected in 7/244 BC samples, whereas PTEN mutations were found in 19 out of 244 BC samples leading to loss of PTEN. Specifically, there are frameshift variants (p.Ile8MetfsTer16 and p.Arg130GlnfsTer4), stop gain variant (p.Arg233Ter, p.Glu242Ter), start lost variant (p.Met1?), inframe deletion variants (p.Ile101del), frameshift deletion variant (p.Ile168SerfsTer11), missense variants (p.Cys136Arg, p.Ile122Asn, p.Phe206Leu, p.Pro30Leu, p.Leu318Phe). Along the PI3K-AKT pathway, we also observed activating mutations in AKT1 (E17K only) in 12/244 samples, PIK3CA (p.His1047Arg, p.Glu545Lys, p.Glu542Lys, etc) in 99/244 samples, PIK3CB variants (p.Gly1031Trp, p.Arg153Cys, p.Tyr888Ter, p.Ser890Cys) in 4/244 samples. Interestingly, PTEN loss and PI3K/AKT pathway alterations were not mutually exclusive events in breast cancer. Conclusions: This study demonstrated the capacity of blood-based detection of gene deletion and genomic variants associated with loss of PTEN function in breast cancer. The findings further revealed the mutational spectra of PTEN-PI3K-AKT pathway alterations that could lead to better understanding of the biological mechanisms of PTEN loss in breast cancer. This blood-based liquid biopsy assay may ultimately result in improvement of precision diagnostics for biomarker-driven treatment options and patient prognosis in breast cancer. Citation Format: Pan Du, Eric Jia, Zhixin Zhao. Blood-based detection of PTEN loss and pathway alterations for personalized treatment of breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-01-20.