Investigation of the Effectiveness of Oleuropein in a Three-Dimensional In Vitro Hepatocellular Tumor Sphere Model.

OBJECTIVES: This study was conducted to examine the dose-related effects over time of oleuropein on the proliferation and area of tumor spheroids in hepatocellular carcinoma cells. MATERIALS AND METHODS: We examined the possible effects of 100 to 500 µM dose concentrations of oleuropein on HepG2 cell proliferation using a real-time cell analyzer. A 3-dimensional hepatocellular carcinoma tumor spheroid model was established by seeding HepG2 cells at a density of 160 cells/well in custom 96-well microplates with low attachment surfaces and culturing for 3 days. Tumor spheres were treated with increasing oleuropein doses for 72 hours, and images were captured every 24 hours. The dose-dependent effects of oleuropein on tumor sphere size were analyzed by measuring the area of tumor spheres with ImageJ software. We conducted oleuropein viability and cytotoxicity analyses using calcein acetoxymethyl ester-based and propidium iodide-based staining in the tumor model. RESULTS: Oleuropein inhibited cell proliferation; as the dose concentration of oleuropein increased, so did its capacity to inhibit cell proliferation (P < .001). The size of untreated tumor spheres increased at 72 hours (P < .001). However, treatment with 100 to 500 µM oleuropein reduced tumor size by 63.56% to 88.06% compared with untreated cells at the end of 72 hours (P < .001). With increasing concentrations, oleuropein inhibited the viability of tumor spheres, eliminating necrotic death caused by tumor hypoxia. CONCLUSIONS: Overall, oleuropein reduced the size of tumors by inhibiting tumor proliferation and viability. In this context, oleuropein could be a candidate molecule for further extensive studies to reduce hepatocellular carcinoma tumors to meet Milan criteria for liver transplant.

Olea europaea L. Leaf Extract Attenuates Temozolomide-Induced Senescence-Associated Secretion Phenotype in Glioblastoma.

Objectives: The purpose of this study was to investigate the effect of Olea europaea L. leaf extract (OLE) on senescence and senescence-associated secretory phenotype (SASP) caused by temozolomide (TMZ) in glioblastoma (GB). Materials and Methods: A senescence ß-galactosidase assay and a colony formation assay were used to determine the effects of OLE, TMZ, and OLE + TMZ on the cellular senescence and aggressiveness of GB cell lines T98G and U87MG. mRNA expression levels of p53, a senescence factor, interleukin (IL)-6, matrix metalloproteinases (MMP)-9, and nuclear factor kappa B1 (NF-κB1) as SASP factors and Bcl-2 and Bax as senolytic markers were assessed using quantitative reverse transcription-real-time polymerase chain reaction. Cells were double-stained with acridine orange and propidium iodide to observe the cell morphology. Results: TMZ increased the senescence rate of GB cells (p<0.001). Besides, OLE + TMZ reduced the proportion of senescent cells (p<0.001) and their capability to form colonies compared to TMZ-only-treated cells. Additionally, OLE + TMZ co-treatment elevated the mRNA expression levels of MMP-9, IL-6, NF-κB1, p53, and the Bax/Bcl-2 ratio compared to TMZ-only treatment. Especially in U87MG cells, involvement of OLE in TMZ treatments increased more than six times in the Bax/Bcl-2 ratio compared to TMZ-only, which induced the apoptosis-like morphological features (p<0.0001). Conclusion: Collectively, our findings presented the inhibitory effect of OLE on TMZ-mediated SASP-factor production in GB and, accordingly, its potential contribution to elongate the time of recurrence.

Olea europaea Leaf Phenolics Oleuropein, Hydroxytyrosol, Tyrosol, and Rutin Induce Apoptosis and Additionally Affect Temozolomide against Glioblastoma: In Particular, Oleuropein Inhibits Spheroid Growth by Attenuating Stem-like Cell Phenotype.

The effects of Olea europaea leaf extract (OLE) phenolics, including oleuropein (OL), hydroxytyrosol (HT), tyrosol (TYR), and rutin against glioblastoma (GB), independently and in combination with temozolomide (TMZ), were investigated in T98G and A172 cells. Cell growth was assessed by WST-1, real-time cell analysis, colony formation, and cell cycle distribution assays. A dual acridine orange propidium iodide (AO/PI) staining and annexin V assay determined cell viability. A sphere-forming assay, an intracellular oxidative stress assay, and the RNA expression of CD133 and OCT4 investigated the GB stem-like cell (GSC) phenotype. A scratch wound-healing assay evaluated migration capacity. OL was as effective as OLE in terms of apoptosis promotion (p < 0.001) and GSC inhibition (p < 0.001). HT inhibited cell viability, GSC phenotype, and migration rate (p < 0.001), but its anti-GB effect was less than the total effect of OLE alone. Rutin decreased reactive oxygen species production and inhibited colony formation and cell migration (p < 0.001). TYR demonstrated the least effect. The additive effects of OL, HT, TYR and rutin with TMZ were significant (p < 0.001). Our data suggest that OL may represent a novel therapeutic approach against GB cells, while HT and rutin show promise in increasing the efficacy of TMZ therapy.

Blood-Based Biomarkers in Afp Normal/Stable Hepatocellular Carcinoma: Diagnostic and Prognostic Relevance of Mir-10b for Patients on Liver Transplant List.

BACKGROUND: As a diagnostic criteria of hepatocellular carcinoma (HCC), the exact threshold of alpha-fetoprotein (AFP) is controversial. In additional, not all HCC tumors are AFP positive or secrete elevated amounts of AFP into the serum. However, the diagnosis of HCC is quite important on the liver transplant list. Therefore, the purpose of this study was to investigate the expression of circulating micro RNAs (miRNAs) in AFP-stable HCC patients. Thus, we aimed to determine a diagnostic biomarker in these patients. METHODS: Sixteen miRNAs were evaluated using a real-time quantitative reverse transcription polymerase chain reaction system in AFP-stable HCC and AFP-trending HCC patients. RESULTS: In our study, 46.7% (n = 28) of the patients diagnosed with HCC had stable/normal AFP levels. We detected that high expression of miR-24, miR-10b and the low expression of miR-143 were independently and significantly associated with HCC in AFP-stable compared with AFP trending (P < .05). Additionally, we demonstrated that the overexpression of miR-10b was associated with poor disease-free survival in HCC (P = 0.001). CONCLUSIONS: Although more clinical validations are needed for the diagnosis of HCC, our current results indicate that the coexistence of high expression of miR-10b and miR-24 may help clinicians adjust in the diagnosis of HCC in patients who are on the liver transplant list but awaiting biopsy for the diagnosis of HCC.

Early-stage colon cancer with high MALAT1 expression is associated with the 5-Fluorouracil resistance and future metastasis.

BACKGROUND: This study aimed to investigate the role of long noncoding RNA (LncRNA) expression profiles to predict relapse and 5-FU response in patients with stage I/II colon cancer (CC). METHODS AND RESULTS: The expression level of 15 LncRNA was analyzed in stage I/II colon tumors of 126 CC patients. To confirm the findings in-vitro, 5FU-resistant HT29 cells were generated by subjecting HT-29 cells to the increasing concentrations of 5FU for 6 months. The 5FU resistance was observed in WST-1 and Annexin V analyses. The colony formation and wound healing assays were assessed to determine the metastatic properties of the cells. Expression levels of LncRNAs and mRNA of EMT-related genes were determined by RT-PCR. The role of LncRNA on metastasis and 5FU sensitivity were confirmed in pcDNA3.0-PTENP1 and si-MALAT1 expressed 5FU-resistant HT29 cell lineages. RESULTS: High MALAT1 (p = 0.0002) and low PTENP1 (p = 0.0044) expressions were significantly associated with 5-FU resistance and tumor relapse in stage I/II CC. The invasiveness and colony-forming characteristics of 5-FU-resistant cell lineages were higher as compared to the parent HT-29. Moreover, the expression of MALAT1 (p = 0.0009) was increased while the expression of PTENP1 (p = 0.0158) decreased in 5FU-resistant-HT-29 cells. Si-MALAT1 treatment increased cell sensitivity to 5FU, whereas it decreased invasive behaviors of 5 FU-resistant-HT-29 cells. CONCLUSION: MALAT1 may be a biomarker in predicting recurrence in early-stage CC. Our findings suggest that a cell-based therapy to target MALAT1 could be established for these patients to prevent metastasis and 5-FU resistance.

Long non-coding RNAs as a predictive markers of group 3 medulloblastomas.

ObjectiveThe appropriate treatments for the different molecular subgroups of medulloblastomas are challenging to determine. Hence, this study aimed to examine the expression profiles of long non-coding RNAs (LncRNAs) to determine a marker that may be important for treatment selection in these subgroups.MethodsChanges in the expression of LncRNAs in the tissues of patients with medulloblastoma, which are classified into four subgroups according to their clinical characteristics and gene expression profiles, were examined via reverse transcription polymerase chain reaction. Moreover, there association with patient prognosis was evaluated.ResultsThe expression levels of MALAT1 and SNGH16 were significantly higher in patients with group 3 medulloblastoma than in those with other subtypes. Patients with high expression levels of MALAT1 and SNGH16 had a relatively shorter overall survival than those with low expression levels.ConclusionsPatients with group 3 medulloblastoma have a high MALAT1 level, which is associated with poor prognosis. Therefore, MALAT1 can be a new therapeutic target in medulloblastoma.

Coexistence of TERT C228T mutation and MALAT1 dysregulation in primary glioblastoma: new prognostic and therapeutic targets.

Objective: This study was designed to conduct molecular classification based on IDH1/2, TERT, ATRX, and DAXX changes in pediatric and adult primary glioblastoma (GB) and to analyze the potential interaction of LncRNA MALAT1 in the determined homogeneous subgroups.Methods: We analyzed the expression profiles of ATRX/DAXX and MALAT1 using the qRT-PCR method and IDH and TERT mutation status using DNA sequencing analysis in 85 primary pediatric and adult GB patients.Results: IDH1 mutation was observed in 5 (5.88%) and TERT mutation in 65 (76.47%) primary pediatric and adult GB patients. ATRX and DAXX were detected in 18 (21.18%) and 7 (8.24%) patients. TERT mutation and loss of ATRX/DAXX were associated with short overall survival (p < 0.001, p < 0.001, respectively). Patients carrying especially TERT C228T mutation had worse prognosis (p < 0.001). Six subgroups were obtained from the genetic analysis. Among the subgroups, MALAT1 was highly expressed in group A that had a single TERT mutation as compared to that in groups D and E (p = 0.001 and p < 0.001, respectively); further, high MALAT1 expression was associated with worse prognosis in patients with C228T mutation (p < 0.001).Conclusions: Our findings highlight that the presence of TERT C228T mutation and expression of MALAT1 can be used as primary targets during the follow-up of primary GB patients and in the development of new treatment strategies.

NEAT1 Is a Novel Oncogenic LncRNA and Correlated with miR-143 in Pediatric Oligodendrogliomas.

INTRODUCTION: The noncoding RNAs (ncRNAs) play a role in biological processes of various cancers including gliomas. The majority of these transcripts are uniquely expressed in differentiated tissues or specific glioma types. Pediatric oligodendroglioma (POG) is a rare subtype of diffuse glioma and accounts for <1% of pediatric brain tumors. Because histologically POG resembles adult OG, the same treatment is applied as adults. However, the significance in predicting outcomes in POG patients is unclear. In this study, we aimed to investigate the prognostic significance of expression -profiles of microRNA (miRNA) and long noncoding RNA -(LncRNA) in POGs. METHODS: We investigated the levels of 13 known miRNAs and 6 LncRNAs in tumor samples from 9 patients with primary POG by using RT-PCR and analyzed their association with outcomes. RESULTS: The expression levels of miR-21, miR-106a, miR-10b, and LncRNA NEAT1 were higher, and the expression level of miR-143 was lower in POG tissues compared with normal brain tissues (p = 0.006, p = 0.032, p = 0.034, p = 0.002, and p = 0.001, respectively). High levels of NEAT1 and low expression of miR-143 were associated with decreased probability of short disease-free survival (p = 0.018 and p = 0.022, respectively). DISCUSSION: NEAT1 and miR-143 levels could serve as reciprocal prognostic predictors of disease progression in patients with POG. New treatment models to regulate the expression levels of NEAT1 and miR-143 will bring a new approach to the therapy of POG.

Inhibitory Effects of Olea europaea Leaf Extract on Mesenchymal Transition Mechanism in Glioblastoma Cells.

BACKGROUND: Glioblastoma (GB) is the most aggressive form of brain tumor. Despite the current treatment methods, the survival rate of patients is very low. Therefore, there is a need to develop new therapeutic agents. The migration and invasion capacity of GB cells is related to mesenchymal transition (MT) mechanism. MATERIALS AND METHODS: The effect of OLE on MT was determined by analysis of the Twist, Snail, Zeb1, N-cadherin and E-cadherin genes in the EMT mechanism. The effect of OLE on cell migration was determined by wound healing test. RESULTS: 2 mg/ml OLE reduced Twist, Snail, Zeb1 and N-cadherin expression and the combination of OLE + TMZ (2 mg/ml OLE + 350 mM TMZ) increased E-cadherin and reduced Twist, Zeb1 and N-cadherin. In addition, co-treatment with OLE increased TMZ-induced anti-invasion properties thought suppressing transcription factors of MT mechanism. CONCLUSION: OLE can enhance the anti-MT activities of TMZ against GB and provide strong evidence that combined treatment with OLE and TMZ has the potential to be an effective alternative approach in GB therapy.

Long noncoding RNA MALAT1 may be a prognostic biomarker in IDH1/2 wild-type primary glioblastomas.

Primary glioblastoma (GB) is the most aggressive type of brain tumors. While mutations in isocitrate dehydrogenase (IDH) genes are frequent in secondary GBs and correlate with a better prognosis, most primary GBs are IDH wild-type. Recent studies have shown that the long noncoding RNA metastasis associated lung adenocarcinoma transcript-1 (MALAT1) is associated with aggressive tumor phenotypes in different cancers. Our aim was to clarify the prognostic significance of MALAT1 in IDH1/2 wild-type primary GB tumors. We analyzed IDH1/2 mutation status in 75 patients with primary GB by DNA sequencing. The expression of MALAT1 was detected in the 75 primary GB tissues and 5 normal brain tissues using reverse transcription quantitative PCR (RT-qPCR). The associations between MALAT1 expression, IDH1/2 mutation status, and clinicopathological variables of patients were determined. IDH1 (R132H) mutation was observed in 5/75 primary GBs. IDH2 (R172H) mutation was not detected in any of our cases. MALAT1 expression was significantly upregulated in primary GB vs. normal brain tissues (p = 0.025). Increased MALAT1 expression in IDH1/2 wild-type primary GBs correlated with patient age and tumor localization (p = 0.032 and p = 0.025, respectively). A multivariate analysis showed that high MALAT1 expression was an unfavorable prognostic factor for overall survival (p = 0.034) in IDH1/2 wild-type primary GBs. High MALAT1 expression may have a prognostic role in primary GBs independent of IDH mutations.

Overexpression of the Long Noncoding RNA HomeoboxA Transcript at the Distal Tip Predicts Poor Prognosis in a KRAS-Independent Manner in Periampullary Region Tumors.

OBJECTIVES: Periampullary region tumors (PRTs) are the fifth highest cause of cancer-related deaths worldwide. Although recent studies have highlighted the prognostic value of the long noncoding RNA HomeoboxA transcript at the distal tip (HOTTIP) in patients with pancreatic ductal adenocarcinoma, the relationship between HOTTIP and clinical outcome of all PRTs remains obscure. The aim of this study was to clarify the prognostic significance of HOTTIP in patients with all PRTs related to KRAS mutational status. METHODS: HomeoboxA transcript at the distal tip expression was detected in 100 PRT samples using quantitative real-time polymerase chain reaction. The associations between HOTTIP levels, clinicopathological factors, and patient prognosis were also analyzed. RESULTS: The expression of HOTTIP was found to be significantly upregulated by 32-fold (P = 0.031) in tumor tissues compared with normal tissues. The over expression of HOTTIP was related with presence of invasion and metastasis (P = 0.0467, P = 0.0256). In addition, increased HOTTIP expression was associated with poor prognosis independent of KRAS mutation (P < 0.001; n = 72). Moreover, multivariate analysis showed that high HOTTIP expression was an unfavorable prognostic factor for overall survival. CONCLUSIONS: Our findings indicate that high levels of HOTTIP expression have the potential to be an independent, unfavorable prognostic factor for patients with PRT.