scholarly journals Effects of endoplasmic reticulum stress on the autophagy, apoptosis, and chemotherapy resistance of human breast cancer cells by regulating the PI3K/AKT/mTOR signaling pathway

Tumor Biology ◽  
2017 ◽  
Vol 39 (5) ◽  
pp. 101042831769756 ◽  
Author(s):  
Jia-Teng Zhong ◽  
Jian Yu ◽  
Hai-Jun Wang ◽  
Yu Shi ◽  
Tie-Suo Zhao ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Cell Viability ◽  
Human Breast Cancer ◽  
Chemotherapy Resistance ◽  
Mtor Signaling Pathway ◽  
Human Breast ◽  
Diphenyltetrazolium Bromide ◽  
Mcf 7

Nowadays, although chemotherapy is an established therapy for breast cancer, the molecular mechanisms of chemotherapy resistance in breast cancer remain poorly understood. This study aims to explore the effects of endoplasmic reticulum stress on autophagy, apoptosis, and chemotherapy resistance in human breast cancer cells by regulating PI3K/AKT/mTOR signaling pathway. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to detect the cell viability of six human breast cancer cell lines (MCF-7, ZR-75-30, T47D, MDA-MB-435s, MDA-MB-453, and MDA-MB-231) treated with tunicamycin (5 µM), after which MCF-7 cells were selected for further experiment. Then, MCF-7 cells were divided into the control (without any treatment), tunicamycin (8 µ), BEZ235 (5 µ), and tunicamycin + BEZ235 groups. Cell viability of each group was testified by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Western blotting was applied to determine the expressions of endoplasmic reticulum stress and PI3K/AKT/mTOR pathway–related proteins and autophagy- and apoptosis-related proteins. Monodansylcadaverine and Annexin V–fluorescein isothiocyanate/propidium iodide staining were used for determination of cell autophagy and apoptosis. Furthermore, MCF-7 cells were divided into the control (without any treatment), tunicamycin (5 µM), cisplatin (16 µM), cisplatin (16 µM) + BEZ235 (5 µM), tunicamycin (5 µM) + cisplatin (16 µM), and tunicamycin (5 µM) + cisplatin (16 µM) + BEZ235 groups. Cell viability and apoptosis were also evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and Annexin V–fluorescein isothiocyanate/propidium iodide staining. In MCF-7 cells treated with tunicamycin, cell viability decreased significantly, but PEAK, eIF2, and CHOP were upregulated markedly and p-PI3K, p-AKT, and p-MTOR were downregulated in dose- and time-dependent manners. In the tunicamycin + BEZ235 group, the cell viability was lower and the apoptosis rate was higher than those of the control and monotherapy groups. Compared with the cisplatin group, the tunicamycin + cisplatin group showed a relatively higher growth inhibition rate; the growth inhibition rate substantially increased in the tunicamycin + cisplatin + BEZ235 group than the tunicamycin + cisplatin group. The apoptosis rate was highest in tunicamycin + cisplatin + BEZ235 group, followed by tunicamycin + cisplatin group and then cisplatin group. Our study provide evidence that endoplasmic reticulum stress activated by tunicamycin could promote breast cancer cell autophagy and apoptosis and enhance chemosensitivity of MCF-7 cells by inhibiting the PI3K/AKT/mTOR signaling pathway.

RSK2 protects human breast cancer cells under endoplasmic reticulum stress through activating AMPKα2-mediated autophagy

Oncogene ◽  
2020 ◽  
Vol 39 (43) ◽  
pp. 6704-6718
Author(s):  
Lan-Ya Li ◽  
Xi-Sha Chen ◽  
Kuan-Song Wang ◽  
Yi-Di Guan ◽  
Xing-Cong Ren ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Cancer Cells ◽  
Human Breast Cancer ◽  
Breast Cancer Cells ◽  
Human Breast Cancer Cells ◽  
Human Breast

scholarly journals Cytotoxic activity of crude saponins from Gaultheria trichophylla against human breast cancer cells MCF-7 and MDA-MB-468

2015 ◽  
Vol 10 (2) ◽  
pp. 443
Author(s):  
Fiaz Alam ◽  
Qazi Najam us Saqib ◽  
Abdul Waheed
Keyword(s):  
Breast Cancer ◽  
Cell Viability ◽  
Crude Extract ◽  
Human Breast Cancer ◽  
Neutral Red ◽  
Breast Cancer Cell Lines ◽  
Dependent Manner ◽  
Human Breast ◽  
Uptake Assay ◽  
Mcf 7

<p>This study was conducted to evaluate <em>Gaultheria trichophylla</em> crude extract and respective saponins fraction against human breast cancer cell lines. In MTT assay, cell viability was inhibited by <em>G. trichophylla</em> crude extract (500 µg/mL) and saponins (200 µg/mL) in a dose dependent manner with maximum inhibition of (82% and 85%) and (71% and 42%) against MCF-7 and MDA MB-468, respectively. In neutral red uptake assay, the cell viability was inhibited by crude extract and saponins (100 µg/mL) in a similar manner with maximum inhibitions of (96% and 93%) and (87% and 61%) against MCF-7 and MDA MB-468, respectively, with respect to 91% and 93% inhibition by actinomycin-D (4 µM). The DAPI (4',6-diamidino-2-phenylindole) (10 µg/mL) staining of MCF-7 cells treated with crude saponins showed shrunken nuclei with apparent nuclear fragmentation indicating apoptosis and in contrast, MDA MB-468 showed necrosis mode of cell death. The study exhibited that the <em>G. trichophylla</em> provides new evidences to further explore this plant for the novel targets in anticancer drug development.</p>

Long Noncoding RNA LINC00261 Induces Chemosensitization to Tamoxifen in Human Breast Cancer

2020 ◽  
Vol 10 (6) ◽  
pp. 789-797
Author(s):  
Zhaoyan Shi ◽  
Weidong Xiao ◽  
Meifang Hu
Keyword(s):  
Breast Cancer ◽  
Protein Expression ◽  
Human Breast Cancer ◽  
Noncoding Rna ◽  
Quantitative Polymerase Chain Reaction ◽  
Chemotherapy Resistance ◽  
Migration And Invasion ◽  
Human Breast ◽  
Mcf 7

Breast cancer (BC) is one of the most prevalent and mortal malignancies in women worldwide, and tamoxifen is the mainstay treatment of breast cancer and the development of resistance represents a major obstacle for a cure. Long non-coding RNAs (LncRNAs) LINC00261 have been identified to serve a key role in the development of several tumors. However, the role of LINC00261 in breast cancer and chemotherapy resistance remains largely unknown. To investigate the role of LINC00261 in BC cells, LINC00261 was upregulated in MCF-7-TAM cells by transfecting with LINC00261 plasmid (pcDNA-LINCC00261). Subsequently, cell viability and drug sensitivity were measured using the CCK-8 assay. Reverse transcription-quantitative polymerase chain reaction (qRT-PCR) was performed to detect the level of LINC00261 in BC cells. Cell migration, invasion, and apoptosis were detected by Transwell, Scratch Test and Flow cytometry, respectively. Additionally, the associated protein expression was detected using Western blot. The results demonstrated that LINC00261 was significantly down-regulated in BC cells, especially in MCF-7-TAM cells. Overexpression of LINC00261 inhibited cell proliferation, migration, and invasion in MCF-7-TAM cells. Further, an abundant of LINC00261 sensitized breast cancer cells to tamoxifen and reduced tamoxifen-induced apoptosis in MCF-7-TAM cells. Finally, LINC00261 significantly regulated the protein expression of drug-resistant genes and the protein expression related to tumor metastasis and cell apoptosis. Therefore, this study revealed that LINC00261 induces chemosensitization to tamoxifen in human breast cancer, it may be a useful biomarker and potential therapeutic target.

Nanoparticle-Aptamer: An Effective Growth Inhibitor for Human Cancer Cells

2009 ◽  
Author(s):  
Kok Hao Chen ◽  
Jong Hyun Choi
Keyword(s):  
Breast Cancer ◽  
Growth Inhibition ◽  
Cell Viability ◽  
Cancer Cells ◽  
Human Breast Cancer ◽  
Breast Cancer Cells ◽  
Semiconductor Nanocrystals ◽  
Human Breast ◽  
Dna Concentration ◽  
Mcf 7

Semiconductor nanocrystals have unique optical properties due to quantum confinement effects, and a variety of promising approaches have been devised to interface the nanomaterials with biomolecules for bioimaging and therapeutic applications. Such bio-interface can be facilitated via a DNA template for nanoparticles as oligonucleotides can mediate the aqueous-phase nucleation and capping of semiconductor nanocrystals.[1,2] Here, we report a novel scheme of synthesizing fluorescent nanocrystal quantum dots (NQDs) using DNA aptamers and the use of this biotic/abiotic nanoparticle system for growth inhibition of MCF-7 human breast cancer cells for the first time. Particularly, we used two DNA sequences for this purpose, which have been developed as anti-cancer agents: 5-GGT GGT GGT GGT TGT GGT GGT GGT GG-3 (also called, AGRO) and 5-(GT)15-3.[3–5] This study may ultimately form the basis of unique nanoparticle-based therapeutics with the additional ability to optically report molecular recognition. Figure 1a shows the photoluminescence (PL) spectra of GT- and AGRO-passivated PbS QD that fluoresce in the near IR, centered at approximately 980 nm. A typical synthesis procedure involves rapid addition of sodium sulfide in the mixture solution of DNA and Pb acetate at a molar ratio of 2:4:1. The resulting nanocrystals are washed to remove unreacted DNA and ions by adding mixture solution of NaCl and isopropanol, followed by centrifugation. The precipitated nanocrystals are collected and re-suspended in aqueous solution by mild sonication. Optical absorption measurements reveal that approximately 90 and 77% of GT and AGRO DNA is removed after the washing process. The particle size distribution in Figure 1b suggests that the GT sequence-capped PbS particles are primarily in 3–5 nm diameter range. These nanocrystals can be easily incorporated with mammalian cells and remain highly fluorescent in sub-cellular environments. Figure 1c serially presents an optical image of a MCF-7 cell and a PL image of the AGRO-capped QD incorporated with the cell. Figure 1. (a) Normalized fluorescence spectra of PbS QD synthesized with GT and AGRO sequences, which were previously developed as anti-cancer agents. The DNA-capped QD fluoresce in the near IR centered at ∼980 nm. (b) TEM image of GT-templated nanocrystals ranging 3–5 nm in diameter. (c) Optical image of an MCF-7 human breast cancer cell after a 12-hour exposure to aptamer-capped QD. (d) PL image of AGRO-QD incorporated with the cell, indicating that these nanocrystals remain highly fluorescent in sub-cellular environments. One immediate concern for interfacing inorganic nanocrystals with cells and tissue for labeling or therapeutics is their cytotoxicity. The nanoparticle cytotoxicity is primarily determined by material composition and surface chemistry, and QD are potentially toxic by generating reactive oxygen species or by leaching heavy metal ions when decomposed.[6] We examined the toxicity of aptamer-passivated nanocrystals with NIH-3T3 mouse fibroblast cells. The cells were exposed to PbS nanocrystals for 2 days before a standard MTT assay as shown in Figure 2, where there is no apparent cytotoxicity at these doses. In contrast, Pb acetate exerts statistically significant toxicity. This observation suggests a stable surface passivation by the DNA aptamers and the absence of appreciable Pb2+ leaching. Figure 2. Viability of 3T3 mouse fibroblast cells after a 2-day exposure to DNA aptamer-capped nanocrystals. There is no apparent dose-dependent toxicity, whereas a statistically significant reduction in cell viability is observed with Pb ions. Note that Pb acetate at 133 μM is equivalent to the Pb2+ amount that was used for PbS nanocrystal synthesis at maximum concentration. Error bars are standard deviations of independent experiments. *Statistically different from control (p&lt;0.005). Finally, we examined if these cyto-compatible nanoparticle-aptamers remained therapeutically active for cancer cell growth inhibition. The MTT assay results in Figure 3a show significantly decreased growth of breast cancer cells incorporated with AGRO, GT, and the corresponding templated nanocrystals, as anticipated. In contrast, 5-(GC)15-3 and the QDs synthesized with the same sequence, which were used as negative controls along with zero-dose control cells, did not alter cell viability significantly. Here, we define the growth inhibition efficacy as (100 − cell viability) per DNA of a sample, because the DNA concentration is significantly decreased during the particle washing. The nanoparticle-aptamers demonstrate 3–4 times greater therapeutic activities compared to the corresponding aptamer drugs (Figure 3b). We speculate that when a nanoparticle-aptamer is internalized by the cancer cells, it forms an intracellular complex with nucleolin and nuclear factor-κB (NF-κB) essential modulator, thereby inhibiting NF-κB activation that would cause transcription of proliferation and anti-apoptotic genes.[7] The nanoparticle-aptamers may more effectively block the pathways for creating anti-apoptotic genes or facilitate the cellular delivery of aptamers via nanoparticle uptake. Our additional investigation indicates that the same DNA capping chemistry can be utilized to produce aptamer-mediated Fe3O4 nanocrystals, which may be potentially useful in MRI and therapeutics, considering their magnetic properties and biocompatibility. In summary, the nanoparticle-based therapeutic schemes developed here should be valuable in developing a multifunctional drug delivery and imaging agent for biological systems. Figure 3. Anti-proliferation of MCF-7 human breast cancer cells with aptamer-passivated nanocrystals. (a) Viability of MCF-7 cells exposed to AGRO and GT sequences, and AGRO-/GT-capped QD for 7 days. The DNA concentration was 10 uM, while the particles were incubated with cells at 75 nM. (b) Growth inhibition efficacy is defined as (100 − cell viability) per DNA to correct the DNA concentration after particle washing.

scholarly journals Chitosan-Coated Halloysite Nanotubes As Vehicle for Controlled Drug Delivery to MCF-7 Cancer Cells In Vitro

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2837
Author(s):  
Emmanuel Nyankson ◽  
Shadrack O. Aboagye ◽  
Johnson Kwame Efavi ◽  
Benjamin Agyei-Tuffour ◽  
Lily Paemka ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Viability ◽  
Breast Cancer Cell ◽  
Human Breast Cancer ◽  
Trypan Blue ◽  
Halloysite Nanotubes ◽  
Human Breast Cancer Cell ◽  
Human Breast ◽  
Mcf 7

The aim of the work is to improve the release properties of curcumin onto human breast cancer cell lines using coated halloysite nanotubes (HNTs) with chitosan as a polycation. A loading efficiency of 70.2% (w/w) was attained for loading 4.9 mg of the drug into 0.204 g bed volume of HNTs using the vacuum suction method. Results acquired from Brunauer-Emmett-Teller (BET), Fourier-transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), scanning electron spectroscopy (SEM), zeta potential, and thermogravimetric analysis (TGA) indicated the presence of the drug and the biopolymer in and around the nanotubes. The release properties of drug-loaded HNTs (DLHNTs) and chitosan-coated drug-loaded HNTs (DLHNTs-CH) were evaluated. The release percentages of DLHNTs and DLHNTs-CH after 6 h were 50.7 and 37%, respectively. Based on the correlation coefficients obtained by fitting the release nature of curcumin from the two samples, the Korsmeyer-Peppas model was found to be the best-fitted model. In vitro cell viability studies were carried out on the human breast cancer cell line MCF-7, using the MTT and trypan blue exclusion assays. Prior to the Trypan blue assay, the IC50 of curcumin was determined to be ~30 µM. After 24 h of incubation, the recorded cell viability values were 94, 68, 57, and 51% for HNTs, DLHNTs-CH, DLHNTs, and curcumin, respectively. In comparison to the release studies, it could be deducted that sustained lethal doses of curcumin were released from the DLHNTs-CH within the same time. It is concluded from this work that the “burst release” of naked drugs could be slowly administered using chitosan-coated HNTs as potential drug carriers.

scholarly journals Deoxyrhapontigenin, a Natural Stilbene Derivative Isolated From Rheum undulatum L. Induces Endoplasmic Reticulum Stress–Mediated Apoptosis in Human Breast Cancer Cells

2016 ◽  
Vol 15 (4) ◽  
pp. NP44-NP52 ◽  
Author(s):  
Thamizhiniyan Venkatesan ◽  
Min-Ji Jeong ◽  
Young-Woong Choi ◽  
Eun-Jin Park ◽  
Samy Korany El-Desouky ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Cancer Cells ◽  
Human Breast Cancer ◽  
Breast Cancer Cells ◽  
Human Breast Cancer Cells ◽  
Human Breast ◽  
Rheum Undulatum ◽  
Mcf 7

Although current chemotherapeutic agents are active at the beginning of therapy, the most common risk is the development of resistance during later stages in almost all cancer types including breast cancer. Hence, investigation of novel drugs is still a priority goal for cancer treatment. The objective of the present study is to investigate the anticancer effect of a derivative of stilbene, deoxyrhapontigenin (DR) isolated from Rheum undulatum L. root extracts against the chemoresistant MCF-7/adr and its parental MCF-7 human breast cancer cells. The morphological images indicate that DR induces an extensive cytoplasmic vacuolation in breast cancer cells. Mechanistic investigations revealed that DR treatment causes endoplasmic reticulum (ER) dilation and upregulated the expression of ER stress markers GRP78, IRE1α, eIF2α, CHOP, JNK, and p38. Subsequently, we also identified that DR increases the levels of apoptotic fragment of PARP (89 kDa) in breast cancer cells. Blocking the expression of one of the components of the ER stress–mediated apoptosis pathway, CHOP using siRNA significantly decreased DR-induced apoptotic cleavage of PARP. In summary, the present study suggests that the induction of ER stress–mediated apoptosis by DR may account for its cytotoxic effects in human breast cancer cells.

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