BRCA1 subcellular localization regulated by PI3K signaling pathway in triple-negative breast cancer MDA-MB-231 cells and hormone-sensitive T47D cells.
Ontology highlight
ABSTRACT:
SUBMITTER: Ma B
PROVIDER: S-EPMC7874579 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:The intracellular kinase MEKK2 (mitogen-activated protein kinase/extracellular-signal-regulated kinase kinase kinase 2) is an upstream regulator of JNK (c-Jun N-terminal kinase), but additional functions for MEKK2 have not been well defined. Silencing MEKK2 expression in invasive breast tumour cells markedly inhibits xenograft metastasis, indicating that MEKK2 controls tumour cell function required for tumour progression. In our previous investigation of MEKK2 function, we discovered that tumour cell attachment to fibronectin recruits MEKK2 to focal adhesion complexes, and that MEKK2 knockdown is associated with stabilized focal adhesions and significant inhibition of tumour cell migration. In the present study we investigate MEKK2 function in focal adhesions and we report that MEKK2 physically associates with the LD1 motif of the focal adhesion protein paxillin. We reveal that MEKK2 induces paxillin ubiquitylation, and that this function requires both the paxillin LD1 motif and MEKK2 kinase activity. Finally, we demonstrate that MEKK2 promotes paxillin redistribution from focal adhesions into the cytoplasm, but does not promote paxillin degradation. Taken together, our results reveal a novel function for MEKK2 as a regulator of ubiquitylation-dependent paxillin redistribution in breast tumour cells.
| S-EPMC4467534 | biostudies-literature
Project description:Standardized treatment guidelines and effective drugs are not available for human triple-negative breast cancer (TNBC). Many efforts have recently been exerted to investigate the efficacy of natural compounds as anticancer agents owing to their low toxicity. However, no study has examined the effects of isobavachalcone (IBC) on the programmed cell death (PCD) of human triple-negative breast MDA-MB-231 cancer cells. In this study, IBC substantially inhibited the proliferation of MDA-MB-231 cells in concentration- and time-dependent manners. In addition, we found that IBC induced multiple cell death processes, such as apoptosis, necroptosis, and autophagy in MDA-MB-231 cells. The initial mechanism of IBC-mediated cell death in MDA-MB-231 cells involves the downregulation of Akt and p-Akt-473, an increase in the Bax/Bcl-2 ratio, and cleaved caspases-3 induced apoptosis; the upregulation of RIP3, p-RIP3 and MLKL induced necroptosis; as well as a simultaneous increase in LC3-II/I ratio induced autophagy. In addition, we observed that IBC induced mitochondrial dysfunction, thereby decreasing cellular ATP levels and increasing reactive oxygen species accumulation to induce PCD. These results suggest that IBC is a promising lead compound with anti-TNBC activity.
| S-EPMC9612085 | biostudies-literature
Project description:Triple-Negative Breast Cancer (TNBC) is a particularly aggressive subtype among breast cancers (BCs), characterized by anoikis resistance, high invasiveness, and metastatic potential as well as Epithelial-Mesenchymal Transition (EMT) and stemness features. In the last few years, our research focused on the function of MCL1, an antiapoptotic protein frequently deregulated in TNBC. Here, we demonstrate that MCL1 inhibition by A-1210477, a specific BH3-mimetic, promotes anoikis/apoptosis in the MDA-MB-231 cell line, as shown via an increase in proapoptotic markers and caspase activation. Our evidence also shows A-1210477 effects on Focal Adhesions (FAs) impairing the integrin trim and survival signaling pathways, such as FAK, AKT, ERK, NF-κB, and GSK3β-inducing anoikis, thus suggesting a putative role of MCL1 in regulation of FA dynamics. Interestingly, in accordance with these results, we observed a reduction in migratory and invasiveness capabilities as confirmed by a decrease in metalloproteinases (MMPs) levels following A-1210477 treatment. Moreover, MCL1 inhibition promotes a reduction in EMT characteristics as demonstrated by the downregulation of Vimentin, MUC1, DNMT1, and a surprising re-expression of E-Cadherin, suggesting a possible mesenchymal-like phenotype reversion. In addition, we also observed the downregulation of stemness makers such as OCT3/4, SOX2, NANOG, as well as CD133, EpCAM, and CD49f. Our findings support the idea that MCL1 inhibition in MDA-MB-231 could be crucial to reduce anoikis resistance, aggressiveness, and metastatic potential and to minimize EMT and stemness features that distinguish TNBC.
| S-EPMC10342057 | biostudies-literature
Project description:Breast cancer remains a leading cause of death in women worldwide. Although breast cancer therapies have greatly advanced in recent years, many patients still develop tumour recurrence and metastasis, and eventually succumb to the disease due to chemoresistance. Citral has been reported to show cytotoxic effect on various cancer cell lines. However, the potential of citral to specifically target the drug resistant breast cancer cells has not yet been tested, which was the focus of our current study.The cytotoxic activity of citral was first tested on MDA-MB-231 cells in vitro by MTT assay. Subsequently, spheroids of MDA-MB-231 breast cancer cells were developed and treated with citral at different concentrations. Doxorubicin, cisplatin and tamoxifen were used as positive controls to evaluate the drug resistance phenotype of MDA-MB-231 spheroids. In addition, apoptosis study was performed using AnnexinV/7AAD flowcytometry. Aldefluor assay was also carried out to examine whether citral could inhibit the ALDH-positive population, while the potential mechanism of the effect of citral was carried out by using quantitative real time- PCR followed by western blotting analysis.Citral was able to inhibit the growth of the MDA-MB-231 spheroids when compared to a monolayer culture of MDA-MB-231 cells at a lower IC50 value. To confirm the inhibition of spheroid self-renewal capacity, the primary spheroids were then cultured to additional passages in the absence of citral. A significant reduction in the number of secondary spheroids were formed, suggesting the reduction of self-renewal capacity of these aldehyde dehydrogenase positive (ALDH+) drug resistant spheroids. Moreover, the AnnexinV/7AAD results demonstrated that citral induced both early and late apoptotic changes in a dose-dependent manner compared to the vehicle control. Furthermore, citral treated spheroids showed lower cell renewal capacity compared to the vehicle control spheroids in the mammosphere formation assay. Gene expression studies using quantitative real time PCR and Western blotting assays showed that citral was able to suppress the self-renewal capacity of spheroids and downregulate the Wnt/?-catenin pathway.The results suggest that citral could be a potential new agent which can eliminate drug-resistant breast cancer cells in a spheroid model via inducing apoptosis.
| S-EPMC5809808 | biostudies-literature
Project description:Since bone metastatic breast cancer is an incurable disease, causing significant morbidity and mortality, understanding of the underlying molecular mechanisms would be highly valuable. Here, we describe in vitro and in vivo evidence for the importance of serine biosynthesis in the metastasis of breast cancer to bone. We first characterized the bone metastatic propensity of the MDA-MB-231(SA) cell line variant as compared to the parental MDA-MB-231 cells by radiographic and histological observations in the inoculated mice. Genome-wide gene expression profiling of this isogenic cell line pair revealed that all the three genes involved in the L-serine biosynthesis pathway, phosphoglycerate dehydrogenase (PHGDH), phosphoserine aminotransferase 1 (PSAT1), and phosphoserine phosphatase (PSPH) were upregulated in the highly metastatic variant. This pathway is the primary endogenous source for L-serine in mammalian tissues. Consistently, we observed that the proliferation of MDA-MB-231(SA) cells in serine-free conditions was dependent on PSAT1 expression. In addition, we observed that L-serine is essential for the formation of bone resorbing human osteoclasts and may thus contribute to the vicious cycle of osteolytic bone metastasis. High expression of PHGDH and PSAT1 in primary breast cancer was significantly associated with decreased relapse-free and overall survival of patients and malignant phenotypic features of breast cancer. In conclusion, high expression of serine biosynthesis genes in metastatic breast cancer cells and the stimulating effect of L-serine on osteoclastogenesis and cancer cell proliferation indicate a functionally critical role for serine biosynthesis in bone metastatic breast cancer and thereby an opportunity for targeted therapeutic interventions. Parental MDA-MB-231 cells and MDA-MB-231(SA) cells were cultured in cell culture flasks. RNA was isolated in order to compare the gene expression profiles of these cell variants. Total of two samples. No replicates.
| S-ECPF-GEOD-20085 | biostudies-other
Project description:BackgroundEnhanced motility of cancer cells is a critical step in promoting tumor metastasis. Lysophosphatidic acid (LPA), representing the major mitogenic activity in serum, stimulates migration in various types of cancer cells. However, the underlying signaling mechanisms for LPA-induced motility of cancer cells remain to be elucidated.Methodology/principal findingsIn this study, we found that LPA dose-dependently stimulated migration of MDA-MB-231 breast cancer cells, with 10 µM being the most effective. LPA also increased ERK activity and the MEK inhibitor U0126 could block LPA-induced ERK activity and cell migration. In addition, LPA induced PAK1 activation while ERK activation and cell migration were inhibited by ectopic expression of an inactive mutant form of PAK1 in MDA-MB-231 cells. Furthermore, LPA increased PI3K activity, and the PI3K inhibitor LY294002 inhibited both LPA-induced PAK1/ERK activation and cell migration. Moreover, in the breast cancer cell, LPA treatment resulted in remarkable production of reactive oxygen species (ROS), while LPA-induced ROS generation, PI3K/PAK1/ERK activation and cell migration could be inhibited by N-acetyl-L-Cysteine, a scavenger of ROS.Conclusions/significanceTaken together, this study identifies a PI3K/PAK1/ERK signaling pathway for LPA-stimulated breast cancer cell migration. These data also suggest that ROS generation plays an essential role in the activation of LPA-stimulated PI3K/PAK1/ERK signaling and breast cancer cell migration. These findings may provide a basis for designing future therapeutic strategy for blocking breast cancer metastasis.
| S-EPMC3012724 | biostudies-literature
Project description:We have previously identified a novel Aurora-A-mediated Serine 379 (S379) phosphorylation of a poly(C)-binding protein, hnRNPK, the overexpression of which is frequently observed in various cancers. It is known that the oncogenic Aurora-A kinase promotes the malignancy of cancer cells. This study aims to investigate the unexplored functions of hnRNPK S379 phosphorylation using MDA-MB-231 cells, a triple negative breast cancer cell that has amplification of the Aurora-A kinase gene. Accordingly, we established two cell lines in which the endogenous hnRNPK was replaced with either S379D or S379A hnRNPK respectively. Notably, we found that a phosphorylation-mimic S379D mutant of hnRNPK suppressed cell migration and, conversely, a phosphorylation-defective S379A mutant promoted migration. Moreover, Twist was downregulated upon hnRNPK S379 phosphorylation, whereas β-catenin and MMP12 were increased when there was loss of hnRNPK S379 phosphorylation in MDA-MB-231 cells. Furthermore, S379A hnRNPK increases stability of β-catenin in MDA-MB-231 cells. In conclusion, our results suggest that hnRNPK S379 phosphorylation regulates migration via the EMT signaling pathway.
| S-EPMC6527834 | biostudies-other
Project description:To determine the effect ALDH1A3 expression on global gene expression in MDA-MB-231 cells and MDA-MB-468 cells In MDA-MB-231 cells, ALDH1A3 was overexperssed (have low endogenous levels of ALDH1A3) and compared to MSCV empty vector control. In MDA-MB-468 cells that have high endogenous levels of ALDH1A3, ALDH1A3 expresion was reduced with ALDH1A3 shRNA1 and compared to scramble shRNA control.
| S-ECPF-GEOD-49322 | biostudies-other
Project description:Shock waves are gaining interests in biological and medical applications. In this work, we investigated the mechanical characteristics of shock waves that affect cell viability. In vitro testing was conducted using the metastatic breast epithelial cell line MDA-MB-231. Shock waves were generated using a high-power pulse laser. Two different coating materials and different laser energy levels were used to vary the peak pressure, decay time, and the strength of subsequent peaks of the shock waves. Within the testing capability of the current study, it is shown that shock waves with a higher impulse led to lower cell viability, a higher detached cell ratio, and a higher cell death ratio, while shock waves with the same peak pressure could lead to different levels of cell damage. The results also showed that the detached cells had a higher cell death ratio compared to the attached cells. Moreover, a critical shock impulse of 5 Pa·s was found to cause the cell death ratio of the detached cells to exceed 50%. This work has demonstrated that, within the testing range shown here, the impulse, rather than the peak pressure, is the governing shock wave parameter for the damage of MDA-MB-231 breast cancer cells. The result suggests that a lower-pressure shock wave with a longer duration, or multiple sequential low amplitude shock waves can be applied over a duration shorter than the fundamental response period of the cells to achieve the same impact as shock waves with a high peak pressure but a short duration. The finding that cell viability is better correlated with shock impulse rather than peak pressure has potential significant implications on how shock waves should be tailored for cancer treatments, enhanced drug delivery, and diagnostic techniques to maximize efficacy while minimizing potential side effects.
| S-EPMC7272042 | biostudies-literature
Project description:Vasculogenic mimicry (VM) with the pattern of endothelial independent tubular structure formation lined by aggressive tumor cells mimics regular tumor blood vessels to ensure robust blood supply and correlates with the proliferation, invasion, metastasis, and poor prognosis of malignant tumors, which was demonstrated to be a major obstacle for resistance to antiangiogenesis therapy. Therefore, it is urgent to discover methods to abrogate the VM formation of tumors, which possesses important practical significance for improving tumor therapy. Brucine is a traditional medicinal herb extracted from seeds of Strychnos nux-vomica L. (Loganiaceae) exhibiting antitumor activity in a variety of cancer models. In the present study, the effect of brucine on vasculogenic mimicry and the related mechanism are to be investigated. We demonstrated that, in a triple-negative breast cancer cell line MDA-MB-231, brucine induced a dose-dependent inhibitory effect on cell proliferation along with apoptosis induction at higher concentrations. The further study showed that brucine inhibited cell migration and invasion with a dose-dependent manner. Our results for the first time indicated that brucine could disrupt F-actin cytoskeleton and microtubule structure, thereby impairing hallmarks of aggressive tumors, like migration, invasion, and holding a possibility of suppressing vasculogenic mimicry. Hence, the inhibitory effect of brucine on vasculogenic mimicry was further verified. The results illustrated that brucine significantly suppressed vasculogenic mimicry tube formation with a dose-dependent effect indicated by the change of the number of tubules, intersections, and mean length of tubules. The in-depth molecular mechanism of vasculogenic mimicry suppression induced by brucine was finally suggested. It was demonstrated that brucine inhibited vasculogenic mimicry which might be through the downregulation of erythropoietin-producing hepatocellular carcinoma-A2 and matrix metalloproteinase-2 and metalloproteinase-9.
| S-EPMC6339755 | biostudies-literature