Valproic Acid (VPA) in Combination with Knockdown of AKT3 and PI3KCA Genes Inhibits Proliferation, Induces Apoptosis and Autophagy in T98G and U87MG Glioblastoma Multiforme Cells

Purpose: Glioblastoma Multiforme (GBM) is a heterogenous and highly vascularized brain tumor that avoid apoptosis due to P-glycoprotein (P-gp) mediated multi-drug resistance. Therefore, development of new therapeutic strategies that induce apoptosis, inhibit proliferation, and overcome multi-drug resistance is urgently warranted. We examined the efficacy of combination of Valproic Acid (VPA) and knockdown of AKT3 and PI3KCA genes in human glioblastoma T98G and U87MG cell lines. Material and Methods: T98G and U87MG cells were transfected with AKT3 or PI3KCA siRNAs. Transfection efficiency was assessed using Flow Cytometry (FC) and fluorescence microscopy. The influence of AKT3 and PI3KCA siRNAs in combination with VPA on T98G and U87MG cell viability, proliferation, apoptosis and autophagy was evaluated as well. Alterations in the mRNA expression of apoptosis-related genes (CASP3 and Bid) were analyzed using QRT-PCR. Results: The transfection of T98G and U87MG cells with AKT3 or PI3KCA siRNAs and exposition on VPA led to a significant reduction in cell viability, the accumulation of subG1-phase cells and a reduced fraction of cells in the S and G2/M phases, apoptosis or necrosis induction and induction of autophagy. Conclusions: The siRNA-induced AKT3 and PI3KCA mRNA knockdown in combination with VPA may offer a novel therapeutic strategy to more effective control the growth of human GBM cells. Thus, knockdown of these genes in combination with valproic acid inhibits proliferation, induces apoptosis and autophagy in T98G and U87MG cells, but further studies are necessary to confirm a positive phenomenon for the treatment of GBM.

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Berberine Improves Chemo-Sensitivity to Cisplatin by Enhancing Cell Apoptosis and Repressing PI3K/AKT/mTOR Signaling Pathway in Gastric Cancer

Frontiers in Pharmacology ◽

10.3389/fphar.2020.616251 ◽

2020 ◽

Vol 11 ◽

Author(s):

Yingying Kou ◽

Bending Tong ◽

Weiqing Wu ◽

Xiangqing Liao ◽

Min Zhao

Keyword(s):

Gastric Cancer ◽

Drug Resistance ◽

Multidrug Resistance ◽

Cell Viability ◽

Cancer Cells ◽

Cell Apoptosis ◽

Mtor Signaling ◽

Multi Drug Resistance ◽

Gastric Cancer Cells

Gastric cancer is one of the most common malignancies ranks as the second leading cause of cancer-related mortality in the world. Cisplatin (DDP) is commonly used for gastric cancer treatment, whereas recurrence and metastasis are common because of intrinsic and acquired DDP-resistance. The aim of this study is to examine the effects of berberine on the DDP-resistance in gastric cancer and explore the underling mechanisms. In this study, we established the DDP-resistant gastric cancer cells, where the IC50 values of DDP in the BGC-823/DDP and SGC-7901/DDP were significantly higher than that in the corresponding parental cells. Berberine could concentration-dependently inhibited the cell viability of BGC-823 and SGC-7901 cells; while the inhibitory effects of berberine on the cell viability were largely attenuated in the DDP-resistant cells. Berberine pre-treatment significantly sensitized BGC-823/DDP and SGC-7901/DDP cells to DDP. Furthermore, berberine treatment concentration-dependently down-regulated the multidrug resistance-associated protein 1 and multi-drug resistance-1 protein levels in the BGC-823/DDP and SGC7901/DDP cells. Interestingly, the cell apoptosis of BGC-823/DDP and SGC-7901/DDP cells was significantly enhanced by co-treatment with berberine and DDP. The results from animals also showed that berberine treatment sensitized SGC-7901/DDP cells to DDP in vivo. Mechanistically, berberine significantly suppressed the PI3K/AKT/mTOR in the BGC-823/DDP and SGC-7901/DDP cells treated with DDP. In conclusion, we observed that berberine sensitizes gastric cancer cells to DDP. Further mechanistic findings suggested that berberine-mediated DDP-sensitivity may be associated with reduced expression of drug transporters (multi-drug resistance-1 and multidrug resistance-associated protein 1), enhanced apoptosis and repressed PI3K/AKT/mTOR signaling.

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The Effects of TiO2 Nanoparticles on Cisplatin Cytotoxicity in Cancer Cell Lines

International Journal of Molecular Sciences ◽

10.3390/ijms21020605 ◽

2020 ◽

Vol 21 (2) ◽

pp. 605 ◽

Cited By ~ 3

Author(s):

Basma Salama ◽

El-Said El-Sherbini ◽

Gehad El-Sayed ◽

Mohamed El-Adl ◽

Koki Kanehira ◽

...

Keyword(s):

Drug Resistance ◽

Cancer Cells ◽

Hepg2 Cells ◽

Titanium Dioxide Nanoparticles ◽

Membrane Receptors ◽

Multi Drug Resistance ◽

A431 Cells ◽

Glycoprotein P ◽

P Glycoprotein ◽

Low Expression

There have been many studies on improving the efficacy of cisplatin and on identifying safe compounds that can overcome multi-drug resistance (MDR) acquired by cancer cells. Our previous research showed that polyethylene glycol-modified titanium dioxide nanoparticles (TiO2 PEG NPs) affect cell membrane receptors, resulting in their aggregation, altered localization and downregulation. TiO2 PEG NPs may affect P-glycoprotein (P-gp), a membrane efflux channel involved in MDR. In this study, we investigated the effect of TiO2 PEG NPs on cisplatin cytotoxicity. We used HepG2 cells, which highly express P-gp and A431 cells, which show low expression of P-gp. The results showed that 10 µg/mL 100 nm TiO2 PEG NPs increased intracellular cisplatin levels and cytotoxicity in HepG2 cells but not in A431 cells. TiO2 PEG NPs treatment decreased the expression level of P-gp in HepG2 cells. Our findings indicate that TiO2 PEG NPs enhance cisplatin cytotoxicity by down regulating P-gp and that TiO2 PEG NPs are promising candidates for inhibiting P-gp and reversing drug resistance acquired by cancer cells.

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Knockdown ofAKT3(PKBγ) andPI3KCASuppresses Cell Viability and Proliferation and Induces the Apoptosis of Glioblastoma Multiforme T98G Cells

BioMed Research International ◽

10.1155/2014/768181 ◽

2014 ◽

Vol 2014 ◽

pp. 1-12 ◽

Cited By ~ 13

Author(s):

Monika Paul-Samojedny ◽

Renata Suchanek ◽

Paulina Borkowska ◽

Adam Pudełko ◽

Aleksander Owczarek ◽

...

Keyword(s):

Glioblastoma Multiforme ◽

Cell Viability ◽

Poor Prognosis ◽

Therapeutic Strategy ◽

Inhibitory Effect ◽

Therapeutic Strategies ◽

Human Brain Tumor ◽

Qrt Pcr ◽

Wide Range ◽

Human Gbm

Glioblastoma multiforme (GBM) is the most malignant and invasive human brain tumor that is difficult to treat and has a very poor prognosis. Thus, new therapeutic strategies that target GBM are urgently needed. The PI3K/AKT/PTEN signaling pathway is frequently deregulated in a wide range of cancers. The present study was designed to examine the inhibitory effect ofAKT3orPI3KCAsiRNAs on GBM cell growth, viability, and proliferation.T98G cells were transfected withAKT3and/orPI3KCAsiRNAs. AKT3 and PI3KCA protein-positive cells were identified using FC and Western blotting. The influence of specific siRNAs on T98G cell viability, proliferation, cell cycle, and apoptosis was evaluated as well using FC. Alterations in the mRNA expression ofAKT3,PI3KCA, and apoptosis-related genes were analyzed using QRT-PCR. Knockdown ofAKT3and/orPI3KCAgenes in T98G cells led to a significant reduction in cell viability, the accumulation of subG1-phase cells and, a reduced fraction of cells in the S and G2/M phases. Additionally, statistically significant differences in the BAX/BCL-2 ratio and an increased percentage of apoptotic cells were found. The siRNA-inducedAKT3andPI3KCAmRNA knockdown may offer a novel therapeutic strategy to control the growth of human GBM cells.

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Identification of multi-drug resistance gene (MDR1) in equine ileum

Ciência Rural ◽

10.1590/s0103-84782006000100048 ◽

2006 ◽

Vol 36 (1) ◽

pp. 298-300

Author(s):

Cláudio Corrêa Natalini ◽

Renata Lehn Linardi

Keyword(s):

Drug Resistance ◽

Mdr1 Gene ◽

Multi Drug Resistance ◽

Drug Elimination ◽

Glycoprotein P ◽

Future Studies ◽

Normal Tissues ◽

P Glycoprotein ◽

The Central Nervous System ◽

The Impact

P-glycoprotein (P-gp) is a membrane transporter encoded in the Multi-drug Resistance (MDR1) gene expressed in several normal tissues and over expressed in tumor cells. P-gp was already identified in different species but not yet in equine. MDR1 gene and P-gp are able to interfere with bioavailability and disposition of several drugs, altering pharmacokinetic and pharmacodinamic of drugs. The presence of the MDR1 and P-gp in the central nervous system blocks the entry of certain drugs in this tissue and reduces drug absorption and enhances drug elimination when P-gp and MDR1 are presented in the gastrointestinal tract. This study showed that the MDR1 gene is present in equine ileum. Future studies on the impact of the P-glycoprotein encoded gene MDR1 on drugs pharmacologic effects in horses are granted.

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MicroRNA-451 regulates chemoresistance in renal cell carcinoma by targeting ATF-2 gene

Experimental Biology and Medicine ◽

10.1177/1535370217701625 ◽

2017 ◽

Vol 242 (12) ◽

pp. 1299-1305 ◽

Cited By ~ 12

Author(s):

Xiang Sun ◽

Longhua Lou ◽

Kezhao Zhong ◽

Lijuan Wan

Keyword(s):

Renal Cell Carcinoma ◽

Drug Resistance ◽

Cell Viability ◽

Cell Carcinoma ◽

Cell Line ◽

Cell Lines ◽

Cell Apoptosis ◽

Renal Cell ◽

Luciferase Reporter ◽

Multi Drug Resistance

Renal cell carcinoma (RCC) is a malignant tumor, which severely threatens human’s life, moreover, the multi-drug resistance (MDR) under RCC undoubtedly strengthen the difficulties in the treatment. MiR-451 has been considered to play an important role in regulation of MDR in several cancers, but the role of it in MDR of RCC has not been explored. This study aims to explore the mechanism of miR-451 as a target to regulate chemotherapy resistance, which is crucial for further exploring novel therapy for RCC. Two human cell lines (ACHN and GRC-1) were performed in this study and adriamycin (ADM) was used to construct MDR cell lines. qRT-PCR was used to determine the mRNA expression of miR-451 and ATF-2. Weston blot was used to determine protein expression. MTT assay and flow cytometry were used for assessing cell viability and apoptosis, individually. Luciferase reporter assay was used to detect the targeting of miR-451 and ATF-2. Results presented that the expression of miR-451 was higher in low MDR cell line (ACHN) comparing with the high MDR cell line (GRC-1), while the expression of ATF-2 revealed an opposite results. MiR-451 targeted ATF-2 and regulated its expression. Overexpression of miR-451 strengthened drug resistance, decreased cell viability, and increased cell apoptosis of GRC-1 pretreated by ADM, while overexpressed ATF-2 reversed the effect induced by miR-451 overexpression. Then miR-451 knockdown improved drug susceptibility, decreased cell apoptosis, and increased cell viability of ACHN induced by ADM, however, ATF-2 suppression reversed the low rate of cell apoptosis and high rate of cell viability induced by miR-451 knockdown. Our results revealed that miR-451 regulates the drug resistance of RCC by targeting ATF-2 gene, which might be critical for overcoming MDR in RCC patients. Impact statement This is the first study to emphasize the expression of miR-451 on regulating multi-drug resistance (MDR) in renal cell carcinoma (RCC). Our study found that miR-451 regulates the drug resistance of RCC by targeting ATF-2, which might be critical for overcoming MDR in RCC patients. This study not only provides solid theory foundation for the clinical therapy, but also offers unique insights for the further RCC research. Furthermore, the study helps us to understand the mechanism of MDR, which was crucial for identifying the chemoresistance on several related tumors.

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