scholarly journals High ROS Production by Celecoxib and Enhanced Sensitivity for Death Ligand-Induced Apoptosis in Cutaneous SCC Cell Lines

2021 ◽  
Vol 22 (7) ◽  
pp. 3622
Author(s):  
Jiaqi Zhu ◽  
Stefanie May ◽  
Claas Ulrich ◽  
Eggert Stockfleth ◽  
Jürgen Eberle
Keyword(s):  
Cell Viability ◽  
Cell Lines ◽  
Therapeutic Potential ◽  
Checkpoint Inhibitors ◽  
Critical Role ◽  
Ros Production ◽  
Enhanced Sensitivity ◽  
Caspase Inhibition ◽  
Inflammatory Drugs ◽  
Induced Apoptosis

Incidence of cutaneous squamous cell carcinoma (cSCC) and actinic keratosis has increased worldwide, and non-steroidal anti-inflammatory drugs as celecoxib are considered for treatment. We show here strong anti-proliferative effects of celecoxib in four cSCC cell lines, while apoptosis and cell viability largely remained unaffected. Impeded apoptosis was overcome in combinations with agonistic CD95 antibody or TNF-related apoptosis-inducing ligand (TRAIL), resulting in up to 60% apoptosis and almost complete loss of cell viability. Proapoptotic caspase cascades were activated, and apoptosis was suppressed by caspase inhibition. TRAIL receptor (DR5) and proapoptotic Bcl-2 proteins (Puma and Bad) were upregulated, while anti-apoptotic factors (survivin, XIAP, cFLIP, Mcl-1, and Bcl-w) were downregulated. Strongly elevated levels of reactive oxygen species (ROS) turned out as particularly characteristic for celecoxib, appearing already after 2 h. ROS production alone was not sufficient for apoptosis induction but may play a critical role in sensitizing cancer cells for apoptosis and therapy. Thus, the full therapeutic potential of celecoxib may be better used in combinations with death ligands. Furthermore, the immune response against cSCC/AK may be improved by celecoxib, and combinations with checkpoint inhibitors, recently approved for the treatment of cSCC, may be considered.

scholarly journals Clinical Impact and Therapeutic Opportunity of Insulin Receptor Substrates 1/2 in Acute Myeloid Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1512-1512
Author(s):  
Juan Luiz Coelho-Silva ◽  
Diego Antonio Pereira-Martins ◽  
Josiane Lilian Schiavinato ◽  
Eduardo Magalhães Rego ◽  
João Agostinho Machado-Neto ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Acute Myeloid Leukemia ◽  
Cell Viability ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Annexin V ◽  
Ros Production ◽  
Insulin Receptor Substrates ◽  
Induced Apoptosis ◽  
Acute Myeloid

Abstract Background: The identification of biological and clinical prognostic factors in acute myeloid leukemia (AML) allowed the definition of patient subgroups and the realization of risk-adapted and targeted treatment strategies. Insulin-like growth factor 1 receptor/Insulin Receptor Substrates (IGF1R/IRS) pathway plays an important role in the development of neoplasia. IRS1/2 activates AKT/mTOR and MAPK pathways, through their interaction with PI3K and GRB2, culminating in increasing cell proliferation. NT157 is an allosteric inhibitor of IGF1R-IRS1/2 signaling that showed antineoplastic effects in preclinical studies of solid tumors. However, IRS1/2 clinical function and NT157 effects were not assessed in AML. Aims: To investigate IRS1 and IRS2 mRNA expression in AML patients and their impact in clinical outcomes, and to analyze the effects of the NT157 in AML cell lines. Material and methods: Comparison of IRS1 (probe nº 204686) and IRS2 (probe nº209184_s) expression from 581 AML patients and 8 CD34+ cells from healthy subjects were analyzed using data from Amazonia! Platform. For survival analysis, IRS1 and IRS2 mRNA expression levels from 173 AML patients (92 male - median age 58 years [range: 18-65]) were obtained from TCGA AML study available online on CBioPortal for Cancer Genomics. NB4, NB4-R2, Kasumi-1 and THP1 cell lines were submitted to NT157 (0.5, 1.0, 2.0, 4.0, 8.0 or 16 µM) 72 hours and evaluated for cell viability (MTT assay), apoptosis (Annexin V/PI), cell cycle (PI), ROS production (DCFDA), mitochondria staining (MitoTracker), and protein expression/activation (western blot). Bone marrow mononuclear cells (BMMC) were obtained from 4 AML patients at diagnosis and submitted to cytotoxic assays. Statistical analyzes were performed using ANOVA, Mann-Whitney or Kruskal-Wallis and Spearman correlation tests, as appropriate. For survival analysis, Kaplan-Meyer curves were compared with the log-rank test. Cox regression analysis was also applied. Results: IRS1 expression, but not IRS2, predicted outcomes. Reduced IRS1 expression showed poorer disease-free survival (DFS) (survival median time [MT]: 10.1 months [mos] vs. 28.4 mos, P<0.001; Hazard ratio [HR]: 0.51 [CI95:0.32 - 0.79]) and overall survival (OS) (MT: 14.5 mos vs. 27.4 mos, P=0.009; HR: 0.61 [CI95:0.42 - 0.88]). IRS1 expression independently predicted poorer DFS (HR: 0.59 [CI95: 0.36 - 0.79]; P= 0.03) using cytogenetic risk stratification, age and leukocytes as confounders. Of note, IRS1 level was positively correlated with proapoptotic CD27 (r=0.51; P<0.001) and with IL17RA (r=0.62; P<0.001) related to CD34 cell differentiation. IRS2 expression was upregulated in AML harboring t(15;17) (n=36; P<0.01) and inv(16) (n=37; P=0.01) in comparison to CD34+. In NB4, NB4-R2 and Kasumi-1 cells, NT157≥0.5µM reduced cell viability (P<0.05) and increased apoptosis (P<0.05). The mean percentage of annexin V+ cells for control, NT157 2.5, 5 and 10µM were 11, 47, 73 and 75% for NB4, 11, 41, 69 and 75% for NB4-R2 and 17, 45, 61 and 64% for Kasumi-1, respectively. In TP53-null cell line THP1, NT157 reduced cell viability at doses higher than 2µM (P<0.05) and induced apoptosis at 10µM (9.1 vs. 25%; P<0.05). NT157 induced ROS production in NB4 (fold-increase of mean fluorescence intensity [MFI]: 25.8 and 24.8), NB4-R2 (MFI: 26.7 and 31.4), Kasumi-1 (MFI: 5.8 and 6.6) and THP1 (MFI: 1.8 and 4.1) at 5 and 10µM (all P<0.05) and increased mitochondrial mass in NB4 (MFI: 3.9 and 3.7), NB4-R2 (MFI: 2.6 and 2.9), Kasumi-1 (MFI: 3.2 and 4.7) and THP-1 (MFI: 2.6 and 2.2) (all P<0.05). NT157 also modulated cell cycle progression, as evidenced by G2/M arrest in THP-1 and sub-G0/G1 in other cell lines (P<0.05). The IGF1R-IRS1/2 inhibitor NT157 reduced activation/expression of IGF1R (Tyr1135), IRS1/2 (Tyr612), AKT1/2/3 (Ser473), P70S6K (Thr421/Ser424), 4EBP1 (Thr70), ERK1/2 (Thr185/Tyr187) and induced DNA damage (increased γH2AX). NT157 did not induce autophagy, as demonstrated by non-degradation of p62 and lack of conversion of LC3BI into LC3BII in cell lines tested. NT157≥0.5 µM reduced cell viability and induced apoptosis in BMMC from 4 AML patients in a dose dependent manner (P<0.05). Conclusions: In AML, downregulation of IRS1 predicted dismal prognosis and the IGF1R-IRS1/2 inhibitor NT157 exerted an antineoplastic activity, downregulated PI3K/AKT and MAPK signaling. IRS1/2 arises as a promising therapeutic target for AML patients. Disclosures No relevant conflicts of interest to declare.

scholarly journals Inhibition of the Myocardin-Related Transcription Factor Pathway Increases Efficacy of Trametinib in NRAS-Mutant Melanoma Cell Lines

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2012
Author(s):  
Kathryn M. Appleton ◽  
Charuta C. Palsuledesai ◽  
Sean A. Misek ◽  
Maja Blake ◽  
Joseph Zagorski ◽  
...  
Keyword(s):  
Cell Lines ◽  
Melanoma Cell ◽  
Therapeutic Potential ◽  
Mapk Pathway ◽  
Mek Inhibitor ◽  
Intrinsic Resistance ◽  
Primary Resistance ◽  
Induced Apoptosis ◽  
Melanoma Cell Lines

The Ras/MEK/ERK pathway has been the primary focus of targeted therapies in melanoma; it is aberrantly activated in almost 80% of human cutaneous melanomas (≈50% BRAFV600 mutations and ≈30% NRAS mutations). While drugs targeting the MAPK pathway have yielded success in BRAFV600 mutant melanoma patients, such therapies have been ineffective in patients with NRAS mutant melanomas in part due to their cytostatic effects and primary resistance. Here, we demonstrate that increased Rho/MRTF-pathway activation correlates with high intrinsic resistance to the MEK inhibitor, trametinib, in a panel of NRAS mutant melanoma cell lines. A combination of trametinib with the Rho/MRTF-pathway inhibitor, CCG-222740, synergistically reduced cell viability in NRAS mutant melanoma cell lines in vitro. Furthermore, the combination of CCG-222740 with trametinib induced apoptosis and reduced clonogenicity in SK-Mel-147 cells, which are highly resistant to trametinib. These findings suggest a role of the Rho/MRTF-pathway in intrinsic trametinib resistance in a subset of NRAS mutant melanoma cell lines and highlight the therapeutic potential of concurrently targeting the Rho/MRTF-pathway and MEK in NRAS mutant melanomas.

Distinct Apoptotic Responses Imparted by c-myc and max

Blood ◽  
1998 ◽  
Vol 92 (3) ◽  
pp. 1003-1010 ◽  
Author(s):  
Chadd E. Nesbit ◽  
Saijun Fan ◽  
Hong Zhang ◽  
Edward V. Prochownik
Keyword(s):  
Cell Death ◽  
Cell Lines ◽  
Ectopic Expression ◽  
Drug Induced ◽  
Enhanced Sensitivity ◽  
Contrast Enhanced ◽  
Apoptotic Pathways ◽  
American Society ◽  
Induced Apoptosis ◽  
Cytokine Deprivation

Abstract The c-myc oncoprotein accelerates programmed cell death (apoptosis) after growth factor deprivation or pharmacological insult in many cell lines. We have shown that max, the obligate c-myc heterodimeric partner protein, also promotes apoptosis after serum withdrawal in NIH3T3 fibroblasts or cytokine deprivation in interleukin-3 (IL-3)-dependent 32D murine myeloid cells. We now show that c-myc– and max-overexpressing 32D cells differ in the nature of their apoptotic responses after IL-3 removal or treatment with chemotherapeutic compounds. In the presence of IL-3, c-myc overexpression enhances the sensitivity of 32D cells to Etoposide (Sigma, St Louis, MO), Adriamycin (Pharmacia, Columbus, OH), and Camptothecin (Sigma), whereas max overexpression increases sensitivity only to Camptothecin. Drug treatment of c-myc–overexpressing cells in the absence of IL-3 did not alter the spectrum of drug sensitivity other than to additively accelerate cell death. In contrast, enhanced sensitivity to Adriamycin, Etoposide, and Taxol (Bristol-Meyers Squibb, Princeton, NJ) was revealed in max-overexpressing cells concurrently deprived of IL-3. Differential rates of apoptosis were not strictly correlated with the ability of the drugs to promote G1 or G2/M arrest. Ectopic expression of Bcl-2 or Bcl-XL blocked drug-induced apoptosis in both cell lines. In contrast, whereas Bcl-2 blocked apoptosis in both cell lines in response to IL-3 withdrawal, Bcl-XL blocked apoptosis in max-overexpressing cells but not in c-myc–overexpressing cells. These results provide mechanistic underpinnings for the idea that c-myc and max modulate distinct apoptotic pathways. © 1998 by The American Society of Hematology.

scholarly journals Cytotoxic Constituents of the Bark of Hypericum roeperianum towards Multidrug-Resistant Cancer Cells

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Michel-Gael F. Guefack ◽  
Francois Damen ◽  
Armelle T. Mbaveng ◽  
Simplice Beaudelaire Tankeo ◽  
Gabin T. M. Bitchagno ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Cell Lines ◽  
Cancer Cell ◽  
Colon Adenocarcinoma ◽  
Cancer Cell Lines ◽  
Multidrug Resistant ◽  
Leukemia Cells ◽  
Ros Production ◽  
Cytotoxic Effects ◽  
Induced Apoptosis

The global cancer burden remains a serious concern with the alarming incidence of one in eight men and one in eleven women dying in developing countries. This situation is aggravated by the multidrug resistance (MDR) of cancer cells that hampers chemotherapy. In this study, the cytotoxicity of the methanol extract (HRB), fractions (HRBa, HRBb, and HRBa1-5), and compounds from the bark of Hypericum roeperianum (HRB) was evaluated towards a panel of 9 cancer cell lines. The mode of action of the HRB and trichadonic acid (1) was also studied. Column chromatography was applied to isolate the constituents of HRB. The cytotoxicity of botanicals and phytochemicals was evaluated by the resazurin reduction assay (RRA). Caspase-Glo assay was used to evaluate the activity of caspases, and reactive oxygen species (ROS) (H2DCFH-DA) were assessed by flow cytometry. Phytochemicals isolated from HRB were trichadonic acid (1), fridelan-3-one (2), 2-hydroxy-5-methoxyxanthone (3), norathyriol (4), 1,3,5,6-tetrahydroxyxanthone (5), betulinic acid (6), 3′-hydroxymethyl-2′-(4″-hydroxy-3″,5″-dimethoxyphenyl)-5′,6′:5,6-(6,8-dihydroxyxanthone)-1′,4′-dioxane (7), and 3′-hydroxymethyl-2′-(4″-hydroxy-3″,5″-dimethoxyphenyl)-5′,6′:5,6-(xanthone)-1′,4′-dioxane (8). Botanicals HRB, HRBa, HRBa2-4, HRBb, and doxorubicin displayed cytotoxic effects towards the 9 tested cancer cell lines. The recorded IC50 values ranged from 11.43 µg/mL (against the P-glycoprotein (gp)-overexpressing CEM/ADR5000 leukemia cells) to 26.75 µg/mL (against HCT116 (p53+/+) colon adenocarcinoma cells) for the crude extract HRB. Compounds 1, 5, and doxorubicin displayed cytotoxic effects towards the 9 tested cancer cell lines with IC50 values varying from 14.44 µM (against CCRF-CEM leukemia cells) to 44.20 µM (against the resistant HCT116 (p53−/−) cells) for 1 and from 38.46 µM (against CEM/ADR5000 cells) to 112.27 µM (against the resistant HCT116 (p53−/−) cells) for 5. HRB and compound 1 induced apoptosis in CCRF-CEM cells. The apoptotic process was mediated by enhanced ROS production for HRB or via caspases activation and enhanced ROS production for compound 1. This study demonstrated that Hypericum roeperianum is a potential source of cytotoxic phytochemicals such as trichadonic acid and could be further exploited in cancer chemotherapy.

scholarly journals Neuroprotective Effects of Alpha-Mangostin on MPP+-Induced Apoptotic Cell Death in Neuroblastoma SH-SY5Y Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Prachya Janhom ◽  
Permphan Dharmasaroja
Keyword(s):  
Cell Death ◽  
Cell Viability ◽  
Caspase 3 ◽  
Nuclear Dna ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Concomitant Treatment ◽  
Ros Production ◽  
Cellular Models ◽  
Induced Apoptosis

In vitrostudies have shown that extracts from mangosteen (Garcinia mangostanaLinn.) act as antioxidants and cytoprotective agents against oxidative damage. The protective effect of alpha-mangostin, the major xanthone found in the pericarp of the mangosteen, in cellular models of Parkinson’s disease (PD), has not been investigated. This study aims to investigate whether alpha-mangostin could protect SH-SY5Y neuroblastoma cells from MPP+-induced apoptosis. The effects of alpha-mangostin on MPP+-induced cell death were evaluated with a cell viability assay, staining for nuclear DNA morphology, flow cytometry for apoptotic cells and reactive oxygen species (ROS) production, quantitative real-time PCR for the expression of p53, Bax, and Bcl-2, and western blot analysis for cleaved caspase-3. Concomitant treatment with alpha-mangostin attenuated the effect of MPP+on cell viability and apoptotic cell death. Alpha-mangostin reduced ROS formation induced by MPP+. Bax/Bcl-2 expression ratio and expression of p53 were significantly lower in cells cocultured with alpha-mangostin and MPP+. The cotreated cells showed a significant decrease in activated caspase-3 compared with MPP+treatment alone. Our data suggest that cytoprotection of alpha-mangostin against MPP+-induced apoptosis may be associated with the reduction of ROS production, modulating the balance of pro- and antiapoptotic genes, and suppression of caspase-3 activation.

scholarly journals Critical role of caveolin-1 in aflatoxin B1-induced hepatotoxicity via the regulation of oxidation and autophagy

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Qingqiang Xu ◽  
Wenwen Shi ◽  
Pan Lv ◽  
Wenqi Meng ◽  
Guanchao Mao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Viability ◽  
Aflatoxin B1 ◽  
Cell Apoptosis ◽  
Critical Role ◽  
Hepatic Cell ◽  
Hepatocellular Injury ◽  
Caveolin 1 ◽  
Induced Apoptosis

AbstractAflatoxin B1 (AFB1) is a potent hepatocarcinogen in humans and exposure to AFB1 is known to cause both acute and chronic hepatocellular injury. As the liver is known to be the main target organ of aflatoxin, it is important to identify the key molecules that participate in AFB1-induced hepatotoxicity and to investigate their underlying mechanisms. In this study, the critical role of caveolin-1 in AFB1-induced hepatic cell apoptosis was examined. We found a decrease in cell viability and an increase in oxidation and apoptosis in human hepatocyte L02 cells after AFB1 exposure. In addition, the intracellular expression of caveolin-1 was increased in response to AFB1 treatment. Downregulation of caveolin-1 significantly alleviated AFB1-induced apoptosis and decreased cell viability, whereas overexpression of caveolin-1 reversed these effects. Further functional analysis showed that caveolin-1 participates in AFB1-induced oxidative stress through its interaction with Nrf2, leading to the downregulation of cellular antioxidant enzymes and the promotion of oxidative stress-induced apoptosis. In addition, caveolin-1 was found to regulate AFB1-induced autophagy. This finding was supported by the effect that caveolin-1 deficiency promoted autophagy after AFB1 treatment, leading to the inhibition of apoptosis, whereas overexpression of caveolin-1 inhibited autophagy and accelerated apoptosis. Interestingly, further investigation showed that caveolin-1 participates in AFB1-induced autophagy by regulating the EGFR/PI3K-AKT/mTOR signaling pathway. Taken together, our data reveal that caveolin-1 plays a crucial role in AFB1-induced hepatic cell apoptosis via the regulation of oxidation and autophagy, which provides a potential target for the development of novel treatments to combat AFB1 hepatotoxicity.

Combination of a Spicamycin Analogue KRN5500 and Chemotherapeutic Agents Synergistically Enhances Their Cytotoxicity in Human Myeloma Cells.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4783-4783
Author(s):  
Hirokazu Miki ◽  
Shuji Ozaki ◽  
Osamu Tanaka ◽  
Shiro Fujii ◽  
Shingen Nakamura ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Cell Growth ◽  
Cell Lines ◽  
Therapeutic Potential ◽  
Flow Cytometric Analysis ◽  
Human Tumor ◽  
Chemotherapeutic Agents ◽  
Dependent Manner ◽  
Induced Apoptosis ◽  
Rpmi 8226

Abstract Multiple myeloma (MM) is a plasma cell malignancy characterized by the accumulation of neoplastic plasma cells in the bone marrow. Although new classes of agents such as thalidomide, lenalidomide, and bortezomib have shown marked anti-MM activity in clinical settings, MM remains an incurable disease due to increased resistance to these agents. Therefore, alternative approaches are necessary to overcome drug resistance in MM. KRN5500 is a new derivative of spicamycin produced by Streptomyces alanosinicus (Kirin Pharma, Tokyo, Japan). This drug potently decreases protein synthesis and inhibits cell growth in human tumor cell lines both in vitro and in vivo. Several phase I studies of KRN5500 were conducted in patients with solid tumors, which showed Cmax values of 1000–3000 nM at the maximum tolerated doses. However, no objective anti-tumor response to KRN5500 alone was observed in these patients. In this study, we examined the anti-tumor activity of KRN5500 against MM cells and evaluated its therapeutic potential in combination with other anti-MM agents. MM cell lines and freshly-isolated MM cells were incubated with various concentrations of KRN5500 for 24 hours. Cell proliferation assay showed marked inhibition of cell growth in MM cells such as RPMI 8226, KMS12-BM, and UTMC-2 (IC50 = 10–40 nM), and U266, MM.1S, and primary MM cells (IC50 = 500–1000 nM). Importantly, a chemotherapy-resistant subclone of RPMI 8226 had a similar sensitivity to KRN5500. Annexin V/propidium iodide staining confirmed that KRN5500 induced apoptosis of MM cells in a dose- and time-dependent manner. Moreover, cleavage of poly (ADP-ribose) polymerase (PARP) was detected after 24 hours with only modest activation of caspase-8, -9, and -3 by immunoblotting. Flow cytometric analysis of anti-apoptotic proteins revealed that apoptosis induced by KRN5500 was associated with down-regulation of Mcl-1 and Bcl-2 expression. To determine the effect of KRN5500 on the unfolded protein response (UPR), splicing of XBP-1 mRNA was analyzed by reverse transcription-polymerase chain reaction. In response to stimulation with KRN5500, splicing of XBP-1 mRNA occurred after 24 hours in RPMI 8226 cells, suggesting that KRN5500-induced apoptosis is mediated in part by the inhibition of UPR. Furthermore, synergistic effects on MM cells were observed when KRN5500 was combined with anti-MM agents including melphalan, dexamethasone, and bortezomib. These results suggest that KRN5500 induces apoptosis in MM cells mainly by the caspase-independent pathway and that its unique mechanism of action provides a valuable therapeutic option to overcome drug resistance in patients with MM.

scholarly journals Oncolytic virotherapy promotes radiosensitivity in soft tissue sarcoma by suppressing anti-apoptotic MCL1 expression

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0250643
Author(s):  
Toshinori Omori ◽  
Hiroshi Tazawa ◽  
Yasuaki Yamakawa ◽  
Shuhei Osaki ◽  
Joe Hasei ◽  
...  
Keyword(s):  
Dna Damage ◽  
Soft Tissue ◽  
Soft Tissue Sarcoma ◽  
Ionizing Radiation ◽  
Combination Therapy ◽  
Cell Lines ◽  
Antitumor Effect ◽  
Therapeutic Potential ◽  
Subcutaneous Xenograft ◽  
Induced Apoptosis

Soft tissue sarcoma (STS) is a rare cancer that develops from soft tissues in any part of the body. Despite major advances in the treatment of STS, patients are often refractory to conventional radiotherapy, leading to poor prognosis. Enhancement of sensitivity to radiotherapy would therefore improve the clinical outcome of STS patients. We previously revealed that the tumor-specific, replication-competent oncolytic adenovirus OBP-301 kills human sarcoma cells. In this study, we investigated the radiosensitizing effect of OBP-301 in human STS cells. The in vitro antitumor effect of OBP-301 and ionizing radiation in monotherapy or combination therapy was assessed using highly radiosensitive (RD-ES and SK-ES-1) and moderately radiosensitive (HT1080 and NMS-2) STS cell lines. The expression of markers for apoptosis and DNA damage were evaluated in STS cells after treatment. The therapeutic potential of combination therapy was further analyzed using SK-ES-1 and HT1080 cells in subcutaneous xenograft tumor models. The combination of OBP-301 and ionizing radiation showed a synergistic antitumor effect in all human STS cell lines tested, including those that show different radiosensitivity. OBP-301 was found to enhance irradiation-induced apoptosis and DNA damage via suppression of anti-apoptotic myeloid cell leukemia 1 (MCL1), which was expressed at higher levels in moderately radiosensitive cell lines. The combination of OBP-301 and ionizing radiation showed a more profound antitumor effect compared to monotherapy in SK-ES-1 (highly radiosensitive) and HT1080 (moderately radiosensitive) subcutaneous xenograft tumors. OBP-301 is a promising antitumor reagent to improve the therapeutic potential of radiotherapy by increasing radiation-induced apoptosis in STS.

scholarly journals RDNA-14. RADIATION-INDUCED miR-4516 CONTRIBUTES TO RADIO-RESISTANCE AND PROMOTES AGGRESSIVE PHENOTYPE IN GLIOBLASTOMA

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi209-vi210
Author(s):  
Ebin Sebastian ◽  
Tiantian Cui ◽  
Erica Hlavin Bell ◽  
Joseph McElroy ◽  
Benjamin Johnson ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Cell Viability ◽  
Cell Lines ◽  
Poor Prognosis ◽  
Radiation Treatment ◽  
Critical Role ◽  
Luciferase Reporter ◽  
Glioblastoma Cell ◽  
Clonogenic Assays ◽  
Glioblastoma Cell Lines

Abstract BACKGROUND Glioblastoma is the most aggressive brain tumor with poor prognosis despite the best available treatment. MicroRNAs (miRNAs) are emerging as promising, novel prognostic biomarkers and therapeutic targets in glioblastoma. In a previous study, we demonstrated that miR-4516 predicts poor prognosis and functions as an oncogene in glioblastoma. Aim of the current study is to examine the role miR-4516 in radiation resistance and identify downstream targets contributing to this phenotype METHODS Radiosensitization was evaluated by cell viability and clonogenic assays. Cell apoptosis was evaluated using flow cytometry and immunoblotting. Potential targets of miR-4516 were identified using bioinformatic analysis (Targetscan and miRDB) and confirmed by luciferase reporter assays. Results were validated using immunoblotting. miR-4516 expression in glioblastoma cell lines after radiation treatment was quantified by qRT-PCR. RESULTS Expression of miR-4516 was increased up to 15 fold following radiation treatment, peaking at around 15min-60 min in primary and established glioblastoma cell lines including GBM 08-387, GBM 30 and U87-MG. Furthermore, inhibition of miR-4516 sensitized GBM 08-387, GBM30 and U87-MG cells to radiation in comparison to control groups as determined by cell viability and clonogenic assays. Further, miR-4516 inhibition induced apoptosis in these cell lines following radiation treatment. While conducting mechanistic studies, we found that the tumor-promoting function of miR-4516 was, in part, mediated by inhibition of p21 and PTPN14, two direct targets of miR-4516 CONCLUSION Our data suggest that radiation induces the expression of miR-4516 in glioblastoma cell lines. This miRNA plays a critical role in radio-resistance and promotes aggressive phenotypes in glioblastoma and therefore, functional analyses of its target pathways may uncover novel therapeutically vulnerable target(s) in glioblastoma. FUNDING: R01CA108633, R01CA169368, RC2CA148190, U10CA180850-01(NCI), Brain Tumor Funders Collaborative Grant, and OSU-CCC (all to AC). The Ton and Patricia Bohnenn Fund for Neuro_Oncology Research (to PR).

scholarly journals miR193b Promotes Apoptosis of Gastric Cancer Cells via Directly Mediating the Akt Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Ruyue Tian ◽  
Hailun Jiang ◽  
Linlin Shao ◽  
Yang Yu ◽  
Qingdong Guo ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Critical Role ◽  
Pik3ca Mutation ◽  
Akt Pathway ◽  
Human Gastric Cancer ◽  
Tumor Type ◽  
Gastric Cancer Cells ◽  
Induced Apoptosis

Gastric cancer (GC) is one of the most common and fatal malignancies worldwide. MicroRNAs (miRNAs) play a critical role in tumor initiation, proliferation, and metastasis of gastric cancer. miR193b has been identified as a tumor suppressor in a variety of tumor types; however, its role in gastric cancer is yet to be determined. Here, we found a significant downregulation of miR193b expression in both human gastric cancer tissues (p<0.05) and human gastric cancer cell lines (p<0.01). Furthermore, the expression level of miR193b correlated with the tumor type, tumor size, and clinical stage (p<0.05). In vitro, miR193b overexpression inhibited cell survival and induced apoptosis in GC cell lines, indicating that miR193b plays a role in the development of gastric cancer. KRAS was verified as the target of miR193b, and KRAS overexpression attenuated miR193b-induced apoptosis (p<0.05). Moreover, we found that the Akt pathway negatively regulated miR193b, also affecting apoptosis. Further analyses indicated that PIK3CA mutation and KRAS amplification are two mutually exclusive pathways (p<0.01), and we hypothesize that both two pathways could result in the carcinogenic overactivation of KRAS. Thus, our results suggest that the Akt-miR193b-KRAS axis may act as a mechanism affecting apoptosis in gastric cancer cells.

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