Spliceosome-Associated MicroRNAs Identified in Breast Cancer Cells Act on Nuclear Targets and Are Potential Indicators for Tumorigenicity

AbstractMicroRNAs (miRNAs) act as negative regulators of gene expression in the cytoplasm. Previous studies identified miRNAs associated with the spliceosome. Here we study three breast-derived cell-lines with increased tumorigenicity (from MCF-10A to MCF-7 and MDA-MB-231) and compared their miRNA sequences at the spliceosome fraction (SF). We report that the SF-miRNAs expression, identity, and pre-miRNA segmental composition vary across these cell-lines. The expression of the majority of the abundant SF-miRNAs (e.g. miR-100, miR-30a, and let-7 members) shows an opposite trend in view of the literature and breast cancer large cohorts. The results suggest that SF-miRNAs act in the nucleus on alternative targets than in the cytoplasm. One such miRNA is miR-7704 whose genomic position overlaps HAGLR, a cancer-related lncRNA. We found an inverse expression of miR-7704 and HAGLR in the tested cell lines. Moreover, inhibition of miR-7704 caused an increase in HAGLR expression. Furthermore, increasing miR-7704 levels attenuated the MDA-MB-231 cell-division rate. While miR-7704 acts as oncomiR in breast cancer patients, it has a tumor-suppressing function in SF, with HAGLR being its nuclear target. Manipulating miR-7704 levels is a potential lead for altering tumorigenicity. Altogether, we report on the potential of manipulating SF-miRNAs as an unexplored route for breast cancer therapeutics.

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Antiestrogen-resistant human breast cancer cells require activated Protein Kinase B/Akt for growth

Endocrine Related Cancer ◽

10.1677/erc.1.00946 ◽

2005 ◽

Vol 12 (3) ◽

pp. 599-614 ◽

Cited By ~ 57

Author(s):

T Frogne ◽

J S Jepsen ◽

S S Larsen ◽

C K Fog ◽

B L Brockdorff ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Patients ◽

Cell Lines ◽

Human Breast Cancer ◽

Neutralizing Antibodies ◽

Breast Cancer Cells ◽

Resistant Cell ◽

Breast Cancer Patients ◽

Human Breast ◽

Mcf 7

Development of acquired resistance to antiestrogens is a major clinical problem in endocrine treatment of breast cancer patients. The IGF system plays a profound role in many cancer types, including breast cancer. Thus, overexpression and/or constitutive activation of the IGF-I receptor (IGF-IR) or different components of the IGF-IR signaling pathway have been reported to render breast cancer cells less estrogen dependent and capable of sustaining cell proliferation in the presence of antiestrogens. In this study, growth of the antiestrogen-sensitive human breast cancer cell line MCF-7 was inhibited by treatment with IGF-IR-neutralizing antibodies. In contrast, IGF-IR-neutralizing antibodies had no effect on growth of two different antiestrogen-resistant MCF-7 sublines. A panel of antiestrogen-resistant cell lines was investigated for expression of IGF-IR and either undetectable or severely reduced IGF-IR levels were observed. No increase in insulin receptor substrate 1 (IRS-1) or total PKB/Akt (Akt) was detected in the resistant cell lines. However, a significant increase in phosphorylated Akt (pAkt) was found in four of six antiestrogen-resistant cell lines. Overexpression of pAkt was associated with increased Akt kinase activity in both a tamoxifen- and an ICI 182,780-resistant cell line. Inhibition of Akt phosphorylation by the phosphatidylinositol 3-kinase (PI3-K) inhibitor wortmannin or the Akt inhibitor SH-6 (structurally modified phosphatidyl inositol ether liquid analog PIA 6) resulted in a more pronounced growth inhibitory effect on the antiestrogen-resistant cells compared with the parental cells, suggesting that signaling via Akt is required for antiestrogen-resistant cell growth in at least a subset of our antiestrogen-resistant cell lines. PTEN expression and activity was not decreased in cell lines overexpressing pAkt. Our data demonstrate that Akt is a target for treatment of antiestrogen-resistant breast cancer cell lines and we suggest that antiestrogen-resistant breast cancer patients may benefit from treatment targeted to inhibit Akt signaling.

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Spliceosome-Associated microRNAs Signify Breast Cancer Cells and Portray Potential Novel Nuclear Targets

International Journal of Molecular Sciences ◽

10.3390/ijms21218132 ◽

2020 ◽

Vol 21 (21) ◽

pp. 8132

Author(s):

Shelly Mahlab-Aviv ◽

Keren Zohar ◽

Yael Cohen ◽

Ayelet R. Peretz ◽

Tsiona Eliyahu ◽

...

Keyword(s):

Breast Cancer ◽

Cell Line ◽

Cell Lines ◽

Suppressor Gene ◽

Breast Cancer Patients ◽

Human Breast ◽

Cancerous Cell ◽

Nuclear Targets ◽

Tumorigenic Cell Line ◽

Mcf 7

MicroRNAs (miRNAs) act as negative regulators of gene expression in the cytoplasm. Previous studies have identified the presence of miRNAs in the nucleus. Here we study human breast cancer-derived cell-lines (MCF-7 and MDA-MB-231) and a non-tumorigenic cell-line (MCF-10A) and compare their miRNA sequences at the spliceosome fraction (SF). We report that the levels of miRNAs found in the spliceosome, their identity, and pre-miRNA segmental composition are cell-line specific. One such miRNA is miR-7704 whose genomic position overlaps HAGLR, a cancer-related lncRNA. We detected an inverse expression of miR-7704 and HAGLR in the tested cell lines. Specifically, inhibition of miR-7704 caused an increase in HAGLR expression. Furthermore, elevated levels of miR-7704 slightly altered the cell-cycle in MDA-MB-231. Altogether, we show that SF-miR-7704 acts as a tumor-suppressor gene with HAGLR being its nuclear target. The relative levels of miRNAs found in the spliceosome fractions (e.g., miR-100, miR-30a, and let-7 family) in non-tumorigenic relative to cancer-derived cell-lines was monitored. We found that the expression trend of the abundant miRNAs in SF was different from that reported in the literature and from the observation of large cohorts of breast cancer patients, suggesting that many SF-miRNAs act on targets that are different from the cytoplasmic ones. Altogether, we report on the potential of SF-miRNAs as an unexplored route for cancerous cell state.

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Characterising the Response of Human Breast Cancer Cells to Polyamine Modulation

Biomolecules ◽

10.3390/biom11050743 ◽

2021 ◽

Vol 11 (5) ◽

pp. 743

Author(s):

Oluwaseun Akinyele ◽

Heather M. Wallace

Keyword(s):

Breast Cancer ◽

Cell Proliferation ◽

Cell Growth ◽

Cancer Cells ◽

Cell Lines ◽

Cancer Cell ◽

Breast Cancer Cells ◽

Growth Responses ◽

Cancer Management ◽

Mcf 7

Breast cancer is a complex heterogeneous disease with multiple underlying causes. The polyamines putrescine, spermidine, and spermine are polycationic molecules essential for cell proliferation. Their biosynthesis is upregulated in breast cancer and they contribute to disease progression. While elevated polyamines are linked to breast cancer cell proliferation, there is little evidence to suggest breast cancer cells of different hormone receptor status are equally dependent on polyamines. In this study, we characterized the responses of two breast cancer cells, ER+ (oestrogen receptor positive) MCF-7 and ER- MDA-MB-231 cell lines, to polyamine modulation and determined the requirement of each polyamine for cancer cell growth. The cells were exposed to DFMO (a polyamine pathway inhibitor) at various concentrations under different conditions, after which several growth parameters were determined. Exposure of both cell lines to DFMO induced differential growth responses, MCF-7 cells showed greater sensitivity to polyamine pathway inhibition at various DFMO concentrations than the MDA-MB-231 cells. Analysis of intracellular DFMO after withdrawal from growth medium showed residual DFMO in the cells with concomitant decreases in polyamine content, ODC protein level, and cell growth. Addition of exogenous polyamines reversed the cell growth inhibition, and this growth recovery appears to be partly dependent on the spermidine content of the cell. Similarly, DFMO exposure inhibits the global translation state of the cells, with spermidine addition reversing the inhibition of translation in the breast cancer cells. Taken together, these data suggest that breast cancer cells are differentially sensitive to the antitumour effects of polyamine depletion, thus, targeting polyamine metabolism might be therapeutically beneficial in breast cancer management based on their subtype.

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ERβ-induced MFN2 inhibits the migration and invasiveness of breast cancer cells by inhibiting the P-AKT signaling pathway

10.21203/rs.3.rs-17183/v1 ◽

2020 ◽

Author(s):

Mengyu Wei ◽

Jun Hao ◽

Xiaomei Liao ◽

Yinfeng Liu ◽

Ruihuan Fu ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Cells ◽

Cancer Cell ◽

Breast Cancer Cell ◽

Breast Cancer Cells ◽

Akt Pathway ◽

Cancer Cell Migration ◽

Breast Cancer Patients ◽

Human Breast ◽

Mcf 7

Abstract Background Mitofusin 2 (MFN2) is localized on the outer membrane of mitochondria and is closely related to the migration of malignant tumor cells. Estrogen receptor β (ERβ) plays an anticancer role in breast cancer. Our previous experiments showed that ERβ can induce MFN2 expression, which then inhibits breast cancer cell migration. However, the exact mechanism by which ERβ-induced MFN2 inhibits breast cancer cell migration is unknown. Methods In this study, immunohistochemistry was first used to detect the expression of MFN2 in breast cancer tissues, and its relationship with the clinicopathological characteristics and prognosis of breast cancer patients was analyzed. MCF-7 and MDA-MB-231 cells were transfected with ERβ and MFN2 knockdown or expression plasmids. Western blot was used to detect the effects of ERβ on MFN2 and MFN2 on P-AKT473 and MMP2; the P-AKT pathway inhibitor LY294002 was administered to cells transfected with MFN2 knockdown plasmids, Western blot, immunocytofluorescence, and a wound healing assay revealed the effect of MFN2 on its downstream signaling pathway and the migration of breast cancer cells. Results This study found that the expression of MFN2 is related to the molecular type and prognosis of breast cancer patients ( P <0.05). The positive expression rate of MFN2 in triple-negative breast cancer was significantly lower than that in the HER2 + and luminal types. However, MFN2 expression was unrelated to age, tumor size, lymph node metastasis, TNM stage, histological type and grade ( P >0.05); ERβ positively regulated MFN2 expression and reduced the migration of both MCF-7 and MDA-MB-231 cells, while MFN2 knockdown increased the expression of P-AKT473 and MMP2. In contrast, the overexpression of MFN2 inhibited the expression of P-AKT473 and MMP2. These results showed that in MFN2 knockdown cells treated with LY294002, P-AKT473 and MMP2 expression levels were reversed. The reversal of P-AKT473 and MMP2 expression levels inhibits the invasiveness of human breast cancer cells. Conclusion MFN2 is related to the molecular subtype and prognosis of breast cancer. In human breast cancer MCF-7 and MDA-MB-231 cells, ERβ-induced MFN2 can inhibit the P-AKT pathway, which inhibits the invasiveness and migration of both breast cancer cell lines.

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The role of miRNAs 34a, 146a, 320a and 542 in the synergistic anticancer effects of methyl 2-(5-fluoro-2-hydroxyphenyl)-1H- benzo[d]imidazole-5-carboxylate (MBIC) with doxorubicin in breast cancer cells

PeerJ ◽

10.7717/peerj.5577 ◽

2018 ◽

Vol 6 ◽

pp. e5577 ◽

Cited By ~ 4

Author(s):

Mohadeseh Hasanpourghadi ◽

Nazia Abdul Majid ◽

Mohd Rais Mustafa

Keyword(s):

Breast Cancer ◽

Cell Lines ◽

Cancer Cell ◽

Breast Cancer Cell ◽

Breast Cancer Cells ◽

Cancer Cell Lines ◽

Human Breast Cancer Cell ◽

Breast Cancer Cell Lines ◽

Human Breast ◽

Mcf 7

Combination Index (CI) analysis suggested that MBIC and doxorubicin synergistically inhibited up to 97% of cell proliferation in ER+/PR+MCF-7 and triple negative MDA-MB-231 breast cancer cell lines. Moreover, treatment of the breast cancer cells with the combined drugs resulted in lower IC50 values in contrast to the individual drug treatment. Small noncoding microRNAs (miRNA) may function as non-mutational gene regulators at post-transcriptional level of protein synthesis. In the present study, the effect of the combined treatment of MBIC and doxorubicin on the expression level of several miRNAs including miR-34a, miR-146a, miR-320a and miR-542 were evaluated in MCF-7 and MDA-MB-231 breast cancer cell lines. These miRNAs have the potential to alter the protein level of survivin, the anti-apoptotic protein and reduce the metastatic activity in human breast cancer cell lines by interfering with the nuclear accumulation of NF-κB. Our results demonstrated the several fold changes in expression of miRNAs, which is drug and cell line dependent. This finding demonstrated a functional synergistic network between miR-34a, miR-320a and miR-542 that are negatively involved in post-transcriptional regulation of survivin in MCF-7 cells. While in MDA-MB-231 cells, changes in expression level of miR-146a was correlated with inhibition of the nuclear translocation of NF-κB. The overall result suggested that alteration in protein level and location of survivin and NF-κB by miR-34a, miR-320a, miR-146a and miR-542, remarkably influenced the synergistic enhancement of combined MBIC and doxorubicin in treatment of aggressive and less aggressive human breast cancer cell lines.

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Comparison of the effect of rhodium citrate-associated iron oxide nanoparticles on metastatic and non-metastatic breast cancer cells

Cancer Nanotechnology ◽

10.1186/s12645-019-0052-1 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 3

Author(s):

Natalia Lemos Chaves ◽

Danilo Aquino Amorim ◽

Cláudio Afonso Pinho Lopes ◽

Irina Estrela-Lopis ◽

Julia Böttner ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Cells ◽

Cell Lines ◽

Breast Cancer Cells ◽

Human Tumor ◽

Metastatic Breast ◽

Cytotoxic Action ◽

Dependent Manner ◽

Metastatic Cells ◽

Mcf 7

Abstract Background Nanocarriers have the potential to improve the therapeutic index of currently available drugs by increasing drug efficacy, lowering drug toxicity and achieving steady-state therapeutic levels of drugs over an extended period. The association of maghemite nanoparticles (NPs) with rhodium citrate (forming the complex hereafter referred to as MRC) has the potential to increase the specificity of the cytotoxic action of the latter compound, since this nanocomposite can be guided or transported to a target by the use of an external magnetic field. However, the behavior of these nanoparticles for an extended time of exposure to breast cancer cells has not yet been explored, and nor has MRC cytotoxicity comparison in different cell lines been performed until now. In this work, the effects of MRC NPs on these cells were analyzed for up to 72 h of exposure, and we focused on comparing NPs’ therapeutic effectiveness in different cell lines to elect the most responsive model, while elucidating the underlying action mechanism. Results MRC complexes exhibited broad cytotoxicity on human tumor cells, mainly in the first 24 h. However, while MRC induced cytotoxicity in MDA-MB-231 in a time-dependent manner, progressively decreasing the required dose for significant reduction in cell viability at 48 and 72 h, MCF-7 appears to recover its viability after 48 h of exposure. The recovery of MCF-7 is possibly explained by a resistance mechanism mediated by PGP (P-glycoprotein) proteins, which increase in these cells after MRC treatment. Remaining viable tumor metastatic cells had the migration capacity reduced after treatment with MRC (24 h). Moreover, MRC treatment induced S phase arrest of the cell cycle. Conclusion MRC act at the nucleus, inhibiting DNA synthesis and proliferation and inducing cell death. These effects were verified in both tumor lines, but MDA-MB-231 cells seem to be more responsive to the effects of NPs. In addition, NPs may also disrupt the metastatic activity of remaining cells, by reducing their migratory capacity. Our results suggest that MRC nanoparticles are a promising nanomaterial that can provide a convenient route for tumor targeting and treatment, mainly in metastatic cells.

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Evaluation of the Impact of Imprinted Polymer Particles on Morphology and Motility of Breast Cancer Cells by Using Digital Holographic Cytometry

Applied Sciences ◽

10.3390/app10030750 ◽

2020 ◽

Vol 10 (3) ◽

pp. 750 ◽

Cited By ~ 3

Author(s):

Megha Patel ◽

Marek Feith ◽

Birgit Janicke ◽

Kersti Alm ◽

Zahra El-Schich

Keyword(s):

Breast Cancer ◽

Sialic Acid ◽

Cancer Cells ◽

Cell Lines ◽

Cell Morphology ◽

Molecularly Imprinted Polymers ◽

Breast Cancer Cells ◽

Molecularly Imprinted ◽

Imprinted Polymers ◽

Mcf 7

Breast cancer is the second most common cancer type worldwide and breast cancer metastasis accounts for the majority of breast cancer-related deaths. Tumour cells produce increased levels of sialic acid (SA) that terminates the monosaccharide on glycan chains of the glycosylated proteins. SA can contribute to cellular recognition, cancer invasiveness and increase the metastatic potential of cancer cells. SA-templated molecularly imprinted polymers (MIPs) have been proposed as promising reporters for specific targeting of cancer cells when deployed in nanoparticle format. The sialic acid-molecularly imprinted polymers (SA-MIPs), which use SA for the generation of binding sites through which the nanoparticles can target and stain breast cancer cells, opens new strategies for efficient diagnostic tools. This study aims at monitoring the effects of SA-MIPs on morphology and motility of the epithelial type MCF-7 and the highly metastatic MDAMB231 breast cancer cell lines, using digital holographic cytometry (DHC). DHC is a label-free technique that is used in cell morphology studies of e.g., cell volume, area and thickness as well as in motility studies. Here, we show that MCF-7 cells move slower than MDAMB231 cells. We also show that SA-MIPs have an effect on cell morphology, motility and viability of both cell lines. In conclusion, by using DH microscopy, we could detect SA-MIPs impact on different breast cancer cells regarding morphology and motility.

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Molecular and chemical characterization by Fourier transform infrared spectroscopy of human breast cancer cells with estrogen receptor expressed and not expressed

Spectroscopy An International Journal ◽

10.1155/2010/498719 ◽

2010 ◽

Vol 24 (5) ◽

pp. 501-510 ◽

Cited By ~ 10

Author(s):

Leila Büttner Mostaço-Guidolin ◽

Luciana Sayuri Murakami ◽

Marina Ribeiro Batistuti ◽

Auro Nomizo ◽

Luciano Bachmann

Keyword(s):

Breast Cancer ◽

Fatty Acids ◽

Estrogen Receptor ◽

Cell Lines ◽

Human Breast Cancer ◽

Breast Cancer Cells ◽

Chemical Characterization ◽

Breast Cancer Cell Lines ◽

Human Breast ◽

Mcf 7

The present study was designed to identify and compare the infrared absorption spectra of two human breast cancer cell lines: MCF-7 (estrogen receptor expressed, ER+) and SKBr3 (estrogen receptor non-expressed, ER–). Comparison between SKBr3 and MCF-7 cells revealed differences in the following absorption band areas: 1087 cm–1(DNA), 1397 cm–1(CH3), 1543 cm–1(amide II), 1651 cm–1(amide I), 2924 cm–1(fatty acids). Additionally, peak shifts were observed at 1122 cm–1(RNA), 1397 cm–1(CH3), 1651 cm–1(amide I), 2851 cm–1(fatty acids) and 2962 cm–1(fatty acids). An analysis of the ratio between band areas was conducted, in order to obtain an index that could effectively distinguish between these two cell lines. The following ratios were found: 1650 cm–1/1540 cm–1, 1650 cm–1/1740 cm–1, 1650 cm–1/1084 cm–1and 1120 cm–1/1084 cm–1. This work demonstrates that it is possible to distinguish between MCF-7 and SKBr3 cells through differences in their FTIR spectra. This work enables distinction between two cell lines from the same breast cancer.

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NLRP3 as Putative Marker of Ipilimumab-Induced Cardiotoxicity in the Presence of Hyperglycemia in Estrogen-Responsive and Triple-Negative Breast Cancer Cells

International Journal of Molecular Sciences ◽

10.3390/ijms21207802 ◽

2020 ◽

Vol 21 (20) ◽

pp. 7802 ◽

Cited By ~ 1

Author(s):

Vincenzo Quagliariello ◽

Michelino De Laurentiis ◽

Stefania Cocco ◽

Giuseppina Rea ◽

Annamaria Bonelli ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Cells ◽

Cell Lines ◽

Triple Negative Breast Cancer ◽

High Glucose ◽

Breast Cancer Cells ◽

Triple Negative ◽

Anticancer Efficacy ◽

Low Glucose ◽

Mcf 7

Hyperglycemia, obesity and metabolic syndrome are negative prognostic factors in breast cancer patients. Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment, achieving unprecedented efficacy in multiple malignancies. However, ICIs are associated with immune-related adverse events involving cardiotoxicity. We aimed to study if hyperglycemia could affect ipilimumab-induced anticancer efficacy and enhance its cardiotoxicity. Human cardiomyocytes and estrogen-responsive and triple-negative breast cancer cells (MCF-7 and MDA-MB-231 cell lines) were exposed to ipilimumab under high glucose (25 mM); low glucose (5.5 mM); high glucose and co-administration of SGLT-2 inhibitor (empagliflozin); shifting from high glucose to low glucose. Study of cell viability and the expression of new putative biomarkers of cardiotoxicity and resistance to ICIs (NLRP3, MyD88, cytokines) were quantified through ELISA (Cayman Chemical) methods. Hyperglycemia during treatment with ipilimumab increased cardiotoxicity and reduced mortality of breast cancer cells in a manner that is sensitive to NLRP3. Notably, treatment with ipilimumab and empagliflozin under high glucose or shifting from high glucose to low glucose reduced significantly the magnitude of the effects, increasing responsiveness to ipilimumab and reducing cardiotoxicity. To our knowledge, this is the first evidence that hyperglycemia exacerbates ipilimumab-induced cardiotoxicity and decreases its anticancer efficacy in MCF-7 and MDA-MB-231 cells. This study sets the stage for further tests on other breast cancer cell lines and primary cardiomyocytes and for preclinical trials in mice aimed to decrease glucose through nutritional interventions or administration of gliflozines during treatment with ipilimumab.

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Induction of multidrug resistance associated protein 2 in tamoxifen-resistant breast cancer cells

Endocrine Related Cancer ◽

10.1677/erc-06-0016 ◽

2007 ◽

Vol 14 (2) ◽

pp. 293-303 ◽

Cited By ~ 50

Author(s):

Hoo Kyun Choi ◽

Jin Won Yang ◽

Sang Hee Roh ◽

Chang Yeob Han ◽

Keon Wook Kang

Keyword(s):

Breast Cancer ◽

Multidrug Resistance ◽

Cancer Cells ◽

Transcriptional Activation ◽

Breast Cancer Cells ◽

Pregnane X Receptor ◽

Pi3 Kinase ◽

Gene Promoters ◽

Breast Cancer Patients ◽

Mcf 7

Acquired resistance to tamoxifen (TAM) is a serious therapeutic problem in breast cancer patients. The transition from chemotherapy-responsive breast cancer cells to chemotherapy-resistant cancer cells is mainly accompanied by the increased expression of multidrug resistance-associated proteins (MRPs). In this study, it was found that TAM-resistant MCF-7 (TAMR-MCF-7) cells expressed higher levels of MRP2 than control MCF-7 cells. Molecular analyses using MRP2 gene promoters supported the involvement of the pregnane X receptor (PXR) in MRP2 overexpression in TAMR-MCF-7 cells. Although CCAAT/enhancer-binding protein β was overexpressed continuously in TAMR-MCF-7 cells, this might not be responsible for the transcriptional activation of the MRP2 gene. In addition, the basal activities of phosphatidylinositol 3-kinase (PI3-kinase) were higher in the TAMR-MCF-7 cells than in the control cells. The inhibition of PI3-kinase significantly reduced both the PXR activity and MRP2 expression in TAMR-MCF-7 cells. Overall, MRP2 induction plays a role in the additional acquisition of chemotherapy resistance in TAM-resistant breast cancer.

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