scholarly journals Evidence for Enhanced Exosome Production in Aromatase Inhibitor-Resistant Breast Cancer Cells

2020 ◽  
Vol 21 (16) ◽  
pp. 5841
Author(s):  
Giuseppina Augimeri ◽  
Giusi La Camera ◽  
Luca Gelsomino ◽  
Cinzia Giordano ◽  
Salvatore Panza ◽  
...  

Aromatase inhibitors (AIs) represent the standard anti-hormonal therapy for post-menopausal estrogen receptor-positive breast cancer, but their efficacy is limited by the emergence of AI resistance (AIR). Exosomes act as vehicles to engender cancer progression and drug resistance. The goal of this work was to study exosome contribution in AIR mechanisms, using estrogen-dependent MCF-7 breast cancer cells as models and MCF-7 LTED (Long-Term Estrogen Deprived) subline, modeling AIR. We found that exosome secretion was significantly increased in MCF-7 LTED cells compared to MCF-7 cells. MCF-7 LTED cells also exhibited a higher amount of exosomal RNA and proteins than MCF-7 cells. Proteomic analysis revealed significant alterations in the cellular proteome. Indeed, we showed an enrichment of proteins frequently identified in exosomes in MCF-7 LTED cells. The most up-regulated proteins in MCF-7 LTED cells were represented by Rab GTPases, important vesicle transport-regulators in cancer, that are significantly mapped in “small GTPase-mediated signal transduction”, “protein transport” and “vesicle-mediated transport” Gene Ontology categories. Expression of selected Rab GTPases was validated by immunoblotting. Collectively, we evidence, for the first time, that AIR breast cancer cells display an increased capability to release exosomes, which may be associated with an enhanced Rab GTPase expression. These data provide the rationale for further studies directed at clarifying exosome’s role on endocrine therapy, with the aim to offer relevant markers and druggable therapeutic targets for the management of hormone-resistant breast cancers.

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Mariana A. Callero ◽  
Andrea I. Loaiza-Pérez

Many estrogen-receptor- (ER-) expressing breast cancers become refractory to ER-based therapies. New antitumor drugs like aminoflavone (AF) and benzothiazoles (Bzs) have been developed and have exquisite antitumor activity in ER+MCF-7 and T47D cells and in a MCF-7 nude mouse model. ER(−) breast cancer cells like MDA-MB-231 are less susceptible. We previously found in MCF-7 cells that these drugs activate the aryl hydrocarbon receptor (AhR) via translocation to the nucleus, induction of AhR-specific DNA binding activity, and expression of CYP1A1, whose transcription is controlled by the AhR-ARNT transcription factor. CYP1A1 metabolizes AF and Bz to a species which directly or after further metabolism damages DNA. In contrast an AhR-deficient variant of MCF-7 or cells with predominantly nuclear AhR expression, such as MDA-MB 231, are resistant. Thus, these drugs, unlike other neoplastic agents, require AhR-mediated signaling to cause DNA damage. This is a new treatment strategy for breast cancers with intact AhR signaling.


2019 ◽  
Vol 2 (3) ◽  
pp. e201900304 ◽  
Author(s):  
Ulrich Blache ◽  
Edward R Horton ◽  
Tian Xia ◽  
Erwin M Schoof ◽  
Lene H Blicher ◽  
...  

Mesenchymal stromal cells (MSCs) are key contributors of the tumour microenvironment and are known to promote cancer progression through reciprocal communication with cancer cells, but how they become activated is not fully understood. Here, we investigate how breast cancer cells from different stages of the metastatic cascade convert MSCs into tumour-associated MSCs (TA-MSCs) using unbiased, global approaches. Using mass spectrometry, we compared the secretomes of MCF-7 cells, invasive MDA-MB-231 cells, and sublines isolated from bone, lung, and brain metastases and identified ECM and exosome components associated with invasion and organ-specific metastasis. Next, we used synthetic hydrogels to investigate how these different secretomes activate MSCs in bioengineered 3D microenvironments. Using kinase activity profiling and RNA sequencing, we found that only MDA-MB-231 breast cancer secretomes convert MSCs into TA-MSCs, resulting in an immunomodulatory phenotype that was particularly prominent in response to bone-tropic cancer cells. We have investigated paracrine signalling from breast cancer cells to TA-MSCs in 3D, which may highlight new potential targets for anticancer therapy approaches aimed at targeting tumour stroma.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2568-2568 ◽  
Author(s):  
Masahiko Zuka ◽  
Yunchao Chang ◽  
Zhaoyi Wang ◽  
James R. Berenson ◽  
Thomas F. Deuel

Abstract Pleiotrophin (PTN, Ptn) is an 18 kD cytokine that is expressed in many human breast cancers and its gene is inappropriately expressed in cell lines derived from these breast cancers. To study the siginificance of inappropriate expression of Ptn in human breast cancer cells on surrounding stromal cells, we first compared nude mouse xenografts of MCF-7 and MCF-7-Ptn cells. MCF-7-Ptn cells lack the Receptor Protein Tyrosine Phosphatase (RPTP)b/z, the PTN receptor, and thus are not responsive to PTN through autocrine or paracrine stimulation. The MCF-7-Ptn cell xenografts grew rapidly whereas MCF-7 cells xenografts were barely detectable 6 weeks after injection. MCF-7-Ptn cells that were co-injected with equal numbers of NIH3T3 cells grew even more rapidly in the flanks of the nude mice. Surprisingly, the MCF-7-Ptn cell explants developed a morphological phenotype remarkably similar to that of the human invasive ductal carcinoma. We then co-cultured MCF-7 cells that express Ptn (MCF-7-Ptn cells) with NIH 3T3 cells. Secretion of PTN from MCF-7-Ptn cells induced formation of sharply defined clusters of MCF-7-Ptn cells, termed “epithelial islands”, that were surrounded by dense fibrous bands interspersed with NIH 3T3 cells that morphologically closely resemble carcinoma associated fibroblasts (CAFs). A striking increase in tropoelastin and expression of type IV procollagen mRNA was identified in NIH3T3 cells co-cultured with MCF-7-Ptn cells. Furthermore, different markers often resulting from stromal cell-carcinoma cell interactions in breast cancer, including protein kinase C (PKC)-d, and both human and murine matrix metalloproteinase (MMP) 9 were identified either in cells or in the culture media taken from MCF-7-Ptn/NIH3T3 cell co-cultures. The induction of these biochemical and morphological features in the co-cultures of MCF-7-Ptn and NIH3T3 cells was demonstrated to be Ptn expression dependent, PTN-secretion dependent, and NIH3T3 cell dependent. The data suggest that PTN secretion alone from human breast cancer cells with inappropriate expression of Ptn is sufficient to markedly remodel the microenvironment of the breast cancer cell and induce a morphological transition of the MCF-7-Ptn cells and NIH3T3 cells to patterns resembling breast carcinomas through activation of the PTN/RPTPb/z signaling pathway in NIH3T3 cells and reciprocal signaling between the carcinoma stromal cells and the PTN secreting breast cancer cells.


2009 ◽  
Vol 390 (7) ◽  
Author(s):  
Aurélie Cazet ◽  
Sophie Groux-Degroote ◽  
Béatrice Teylaert ◽  
Kyung-Min Kwon ◽  
Sylvain Lehoux ◽  
...  

Abstract The disialoganglioside GD3 is an oncofetal marker of a variety of human tumors including melanoma and neuroblastoma, playing a key role in tumor progression. GD3 and 9-O-acetyl-GD3 are overexpressed in approximately 50% of invasive ductal breast carcinoma, but no relationship has been established between disialoganglioside expression and breast cancer progression. In order to determine the effect of GD3 expression on breast cancer development, we analyzed the biosynthesis of gangliosides in several breast epithelial cell lines including MDA-MB-231, MCF-7, BT-20, T47-D, and MCF10A, by immunocytochemistry, flow cytometry, and real-time PCR. Our results show that, in comparison to tumors, cultured breast cancer cells express a limited pattern of gangliosides. Disialogangliosides were not detected in any cell line and GM3 was only observed at the cell surface of MDA-MB-231 cells. To evaluate the influence of GD3 in breast cancer cell behavior, we established and characterized MDA-MB-231 cells overexpressing GD3 synthase. We show that GD3 synthase expressing cells accumulate GD3, GD2, and GT3 at the cell surface. Moreover, GD3 synthase overexpression bypasses the need of serum for cell growth and increases cell migration. This suggests that GD3 synthase overexpression may contribute to increasing the malignant properties of breast cancer cells.


2017 ◽  
Vol 37 (3) ◽  
Author(s):  
Shaonan Yu ◽  
Yan Chen ◽  
Xuefeng Li ◽  
Zhongli Gao ◽  
Guifeng Liu

Chemokine (C-X-C motif) receptor 4 (CXCR4) has been reported as a poor prognostic biomarker in human breast cancers, and has been suggested as a promising therapeutic target of breast cancer treatment. The present study aims to investigate the delivery efficiency of siRNA by chitosan into breast cancer cells, and then to examine the regulatory role by chitosan nanoparticle-delivered siRNA on CXCR4 expression and on the chemosensitivity of breast cancer cells. Our results demonstrated that the siRNA could be capsuled by chitosan into nanoparticles with a diameter of 80–110 nm, and with a zeta potential of 20–50 mV. The chitosan nanoparticle delivered siRNA efficiently into breast cancer MCF-7 cells significantly reduced the expression of CXCR4 in both mRNA and protein levels. Moreover, the reduced CXCR4 by chitosan nanoparticle-delivered siRNA was associated with increased sensitivity of breast cancer cells to cisplatin. Reduced growth and increased apoptosis of MCF-7 cells were observed in the CXCR4 siRNA group than in the control siRNA group. Taken together, our results present the treatment potential of chitosan nanoparticle-delivered siRNA targeting CXCR4 in breast cancers.


Endocrinology ◽  
2014 ◽  
Vol 155 (9) ◽  
pp. 3251-3261 ◽  
Author(s):  
Julia K. Blackmore ◽  
Sudipan Karmakar ◽  
Guowei Gu ◽  
Vaishali Chaubal ◽  
Liguo Wang ◽  
...  

Abstract The SMRT coregulator functions as a dual coactivator and corepressor for estrogen receptor-α (ERα) in a gene-specific manner, and in several studies its elevated expression correlates with poor outcome for breast cancer patients. A specific role of SMRT in breast cancer progression has not been elucidated, but SMRT knock-down limits estradiol-dependent growth of MCF-7 breast cancer cells. In this study, small-interfering RNA (siRNA) and short-hairpin RNA (shRNA) approaches were used to determine the effects of SMRT depletion on growth of ERα-positive MCF-7 and ZR-75–1 breast cancer cells, as well as the ERα-negative MDA-MB-231 breast cancer line. Depletion of SMRT inhibited growth of ERα-positive cells grown in monolayer but had no effect on growth of the ERα-negative cells. Reduced SMRT levels also negatively impacted the anchorage-independent growth of MCF-7 cells as assessed by soft agar colony formation assays. The observed growth inhibitions were due to a loss of estradiol-induced progression through the G1/S transition of the cell cycle and increased apoptosis in SMRT-depleted compared with control cells. Gene expression analyses indicated that SMRT inhibits apoptosis by a coordinated regulation of genes involved in apoptosis. Functioning as a dual coactivator for anti-apoptotic genes and corepressor for pro-apoptotic genes, SMRT can limit apoptosis. Together these data indicate that SMRT promotes breast cancer progression through multiple pathways leading to increased proliferation and decreased apoptosis.


Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 304
Author(s):  
Asal Jalal Abadi ◽  
Ali Zarrabi ◽  
Mohammad Hossein Gholami ◽  
Sepideh Mirzaei ◽  
Farid Hashemi ◽  
...  

MicroRNAs (miRNAs) are well-known regulators of biological mechanisms with a small size of 19–24 nucleotides and a single-stranded structure. miRNA dysregulation occurs in cancer progression. miRNAs can function as tumor-suppressing or tumor-promoting factors in cancer via regulating molecular pathways. Breast and lung cancers are two malignant thoracic tumors in which the abnormal expression of miRNAs plays a significant role in their development. Phosphatase and tensin homolog (PTEN) is a tumor-suppressor factor that is capable of suppressing the growth, viability, and metastasis of cancer cells via downregulating phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling. PTEN downregulation occurs in lung and breast cancers to promote PI3K/Akt expression, leading to uncontrolled proliferation, metastasis, and their resistance to chemotherapy and radiotherapy. miRNAs as upstream mediators of PTEN can dually induce/inhibit PTEN signaling in affecting the malignant behavior of lung and breast cancer cells. Furthermore, long non-coding RNAs and circular RNAs can regulate the miRNA/PTEN axis in lung and breast cancer cells. It seems that anti-tumor compounds such as baicalein, propofol, and curcumin can induce PTEN upregulation by affecting miRNAs in suppressing breast and lung cancer progression. These topics are discussed in the current review with a focus on molecular pathways.


2021 ◽  
Author(s):  
Atefeh Sharif Hoseini ◽  
Masoud Heshmati ◽  
Amin Soltani ◽  
Hedayatollah Shirzad ◽  
Morteza Sedehi ◽  
...  

Abstract Bromodomain and extra-terminal (BET) proteins are recognized acetylated lysine of histone 4 and act as scaffolds to recruit many other proteins to promoters and at enhancers of active genes, especially at the super-enhancers of key genes, driving the transcription process and have been identified as potential therapeutic targets in breast cancer. However, the efficacy of BET inhibitors such as JQ1 in breast cancer therapy is impeded by IL-6 through an as yet defined mechanism. We investigated the interplay between IL-6 and JQ1 in MCF-7 and MDA-MB-231 human breast cancer cells. Here we demonstrate that the efficacy of JQ1 on the inhibition of cell growth and apoptosis was stronger in MDA-MB-231 cells than in MCF-7 cells. Further, MCF-7 cells, but not MDA-MB-231 cells, exhibited increased expression of CXCR4 following IL-6 treatment. JQ1 significantly reduced CXCR4 surface expression in both cell lines and diminished the effects of IL-6 pre-treatment on MCF-7 cells. While IL-6 suppressed the extension of breast cancer stem cells (BCSCs) in MCF-7 cells, JQ1 impeded its inhibitory effect. In addition, in MCF-7 cells JQ1 increased the number of senescent cells in a time-dependent manner. Analysis of gene expression indicated that JQ1 and IL-6 synergistically increase SNAIL expression and decrease c-MYC expression in MCF-7 cells. So, the BET proteins are promising, novel therapeutic targets in late-stage breast cancers.


2021 ◽  
Author(s):  
Chao Lv ◽  
Yun Huang ◽  
Rui Huang ◽  
Qun Wang ◽  
Hongwei Zhang ◽  
...  

Abstract Background: Signal transducer and activator of transcription 3 (STAT3) is constitutively activated in multiple malignant tumors. Compared with regular estrogen receptor (ER)-positive breast cancers, the patients with tamoxifen-resistant breast cancers often exhibit higher level of STAT3 phosphorylation. Narciclasine (Nar) possesses strong inhibiting effects against a variety of cancer cells, however, the underlying antitumor target(s)/mechanism(s) remains barely understood. Methods: Targets prediction of narciclasine was performed by combining connectivity map (CMAP) and drug affinity responsive target stability (DARTS) strategy. Molecular and biochemical methods were used to elucidate the distinct mechanisms of narciclasine targeting STAT3. The narciclasine nano-delivery system was synthesized by thin film hydration method. Xenograft models were established to determine antitumor activity of narciclasine and its liposome in vivo.Results: In this study, we successfully identified the STAT3 was the direct target of Nar through the combination strategies of CMAP and DARTS. In ER-positive breast cancer cells, Nar could suppress phosphorylation, activation, dimerization, and nuclear translocation of STAT3 by directly binding with the STAT3 SH2 domain. Additionally, Nar could also specifically promote total STAT3 degradation via proteasome pathway and reduce the STAT3 protein stability in tamoxifen-resistant breast cancer cells (MCF-7/TR). This distinct mechanism of Nar targeting STAT3 was mainly attributed to the various levels of reactive oxygen species (ROS) in regular and tamoxifen-resistant ER-positive breast cancer cells. Meanwhile, Nar loaded nanoparticles could markedly decrease the protein levels of STAT3 in tumor sites, resulting in significant MCF-7/TR xenograft tumor regression without obvious toxicity. Conclusions: Our findings successfully highlight the STAT3 as the direct therapeutic target of Nar in ER-positive breast cancer cells, especially Nar leaded STAT3 degradation as a promising strategy for the tamoxifen-resistant breast cancer treatment.


2019 ◽  
Author(s):  
Shengdi Guo ◽  
Xianxian Yao ◽  
Qin Jiang ◽  
Kuang Wang ◽  
Yuanying Zhang ◽  
...  

AbstractRecently, chemodynamic therapy (CDT) has represented a new approach for cancer treatment with low toxicity and side effects. Nonetheless, it has been a challenge to improve the therapeutic effect through increasing the amount of reactive oxygen species (ROS). Herein, we increased the amount of ROS agents in the Fenton-like reaction by loading dihydroartemisinin (DHA) which was an artemisinin (ART) derivative containing peroxide groups, into magnetic nanoparticles (MNP), thereby improving the therapeutic effect of CDT. Blank MNP were almost non-cytotoxic, whereas three MNP loading ART-based drugs, MNP-ART, MNP-DHA, and MNP-artesunate (MNP-AS), all showed significant killing effect on breast cancer cells (MCF-7 cells), in which MNP-DHA were the most potent. What’s more, the MNP-DHA showed high toxicity to drug-resistant breast cancer cells (MCF-7/ADR cells), demonstrating its ability to overcome multidrug resistance (MDR). The study revealed that MNP could produce ferrous ions under the acidic condition of tumor microenvironment, which catalyzed DHA to produce large amounts of ROS, leading to cell death. Further experiments also showed that the MNP-DHA had significant inhibitory effect on another two aggressive breast cancer cell lines (MDA-MB-231 and MDA-MB-453 cells), which indicated that the great potential of MNP-DHA for the treatment of intractable breast cancers.


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