scholarly journals Effects of the surface charge of polyamidoamine dendrimers on cellular exocytosis and the exocytosis mechanism in multidrug-resistant breast cancer cells

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Jie Zhang ◽  
Mingjuan Li ◽  
Mingyue Wang ◽  
Hang Xu ◽  
Zhuoxiang Wang ◽  
...  

Abstract Background Polyamidoamine (PAMAM) dendrimer applications have extended from tumor cells to multidrug-resistant tumor cells. However, their transportation in multidrug-resistant tumor cells remains unclear. Herein, we investigated the exocytosis rule and mechanism of PAMAM dendrimers in multidrug-resistant tumor cells. Results Using a multidrug-resistant human breast cancer cell model (MCF-7/ADR), we performed systematic analyses of the cellular exocytosis dynamics, pathways and mechanisms of three PAMAM dendrimers with different surface charges: positively charged PAMAM-NH2, neutral PAMAM-OH and negatively charged PAMAM-COOH. The experimental data indicated that in MCF-7/ADR cells, the exocytosis rate was the highest for PAMAM-NH2 and the lowest for PAMAM-OH. Three intracellular transportation processes and P-glycoprotein (P-gp) participated in PAMAM-NH2 exocytosis in MCF-7/ADR cells. Two intracellular transportation processes, P-gp and multidrug resistance (MDR)-associated protein participated in PAMAM-COOH exocytosis. P-gp and MDR-associated protein participated in PAMAM-OH exocytosis. Intracellular transportation processes, rather than P-gp and MDR-associated protein, played major roles in PAMAM dendrimer exocytosis. PAMAM-NH2 could enter MCF-7/ADR cells by forming nanoscale membrane holes, but this portion of PAMAM-NH2 was eliminated by P-gp. Compared with PAMAM-OH and PAMAM-COOH, positively charged PAMAM-NH2 was preferentially attracted to the mitochondria and cell nuclei. Major vault protein (MVP) promoted exocytosis of PAMAM-NH2 from the nucleus but had no effect on the exocytosis of PAMAM-OH or PAMAM-COOH. Conclusions Positive charges on the surface of PAMAM dendrimer promote its exocytosis in MCF-7/ADR cells. Three intracellular transportation processes, attraction to the mitochondria and cell nucleus, as well as nuclear efflux generated by MVP led to the highest exocytosis observed for PAMAM-NH2. Our findings provide theoretical guidance to design a surface-charged tumor-targeting drug delivery system with highly efficient transfection in multidrug-resistant tumor cells. Especially, to provide more DNA to the nucleus and enhance DNA transfection efficiency in multidrug-resistant tumor cells using PAMAM-NH2, siRNA-MVP or an inhibitor should be codelivered to decrease MVP-mediated nuclear efflux. Graphical abstract

2021 ◽  
Vol 11 (2) ◽  
pp. 326-332
Author(s):  
Le Ma ◽  
Zhenyu Liu ◽  
Zhimin Fan

Breast cancer is one of the most prevailing cancers in females, while the cancerous heterogeneity hinders its early diagnosis and subsequent therapy. miR-143-3p is a critical mediator in malignancy development and tumorigenesis as a tumor suppressor. Its role in various tumor entities has been investigated, such as colon cancer and breast cancer. Using MCF-7 breast cancer cell model, we planned to explore the underlying mechanisms of miR-143/KLF-5 axis in retarding breast cancer cells growth. Bioinformatics analysis searched the target KLF5 of miR-143, and the miR-143-targeted mimic and inhibitor were employed to detect the changes of KLF5. After transfection of mimic miR-143, the CCK-8 reagent assessed cell proliferation. Based on optimal stimulation time, miR-143 stimulation model was established, followed by determining expression of KLF5, EGFR and PCNA via western blot and qPCR. Eventually, siRNA-KLF5 was applied to silencing KLF5 level to evaluate its role in MCF-7 cells. The transcription and translation levels of KLF5 were diminished in miR-143-mimic transfected MCF-7 cells, while enhanced in miR-143-inhibitor transfected MCF-7 cells. When MCF-7 cells were transfected with miR-143-mimic at different time points, 48 hours was found to be the optimal transfection time, with reduced transcription and translation levels of KLF5, EGFR and PCNA. The transcription and translation levels of PNCA and EGFR were declined after silencing KLF5 by siRNA. miR-143/KLF5 axis could retard the proliferation of MCF-7 breast cancer cells.


2021 ◽  
Vol 13 (7) ◽  
pp. 1295-1303
Author(s):  
Guangheng Liu ◽  
Xiangfeng Yang ◽  
Qiming Niu ◽  
Wenkui Sun

ABSTRACTA new type of difolate targeting nano-level ultrasound contrast agent ((folate molecule, FOL)2-TUAs) was prepared, so as to investigate its targeted binding effect with human breast cancer mammary carcinoma cells (MCF-7) in vitro. L-2-aminoadipic acid (L-2-AD) as a branch unit was inserted at the hydroxyl end of distearoyl phosphatidylethanolamine (DISP)-PEG2000-COOH to construct a tree structure. At this time, the free hydroxyl group in the distearoyl phosphatidylethanolamine (DISP)-PEG2000-COOH structure modified the FOL with the help of N-Hydroxysuccinimide/N,N'-dicyclohexylcarbodiimide (NHS/DCC). Each 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DISP-PEG2000) connected two FOLs to generate difolate targeted nanomaterials. Nano laser particle size (PS) and Zeta potential analyzer (ZPA) were applied to analyze the physical characteristics of the material such as PS and dispersion, and the enhanced development effect in vitro was detected by the ultrasonic diagnostic instrument. Besides, the targeted binding ability of the contrast agent based on this material to folate receptor (FR) overexpressing MCF-7 cells was analyzed by flow cytometry (FCM) and fluorescence microscope. In the experiment, hydrogen-1 nuclear magnetic resonance (1H NMR) demonstrated that (FOL)2-TUAs was successfully synthesized. The surface of this material was round and uniformly distributed without aggregation. According to the relative number of FOL molecules, non-targeted nano-agent (U-TUA), monofolate targeted nano-agent (FOL-TUA), and difolate targeted nano-agent ((FOL)2-TUA) were obtained. The in vitro imaging showed that different materials exhibited enhanced imaging effects in ultrasonic diagnostic equipment. FCM and fluorescence microscopy both indicated that the difolate TUA could achieve a good binding to MCF-7 cells. Most of the nano-agents were attached to the cell membrane, surrounded by red fluorophore, namely increasing the FOL content of DISP-PEG2000 chain could enhance the targeted binding ability of tumor cells.


2004 ◽  
Vol 279 (44) ◽  
pp. 45855-45864 ◽  
Author(s):  
Xiaojian Wang ◽  
Nan Li ◽  
Bin Liu ◽  
Hongying Sun ◽  
Taoyong Chen ◽  
...  

The phosphatidylethanolamine (PE)-binding proteins (PEBPs) are an evolutionarily conserved family of proteins with pivotal biological functions. Here we describe the cloning and functional characterization of a novel family member, human phosphatidylethanolamine-binding protein 4 (hPEBP4). hPEBP4 is expressed in most human tissues and highly expressed in tumor cells. Its expression in tumor cells is further enhanced upon tumor necrosis factor (TNF) α treatment, whereas hPEBP4 normally co-localizes with lysosomes, TNFα stimulation triggers its transfer to the cell membrane, where it binds to Raf-1 and MEK1. L929 cells overexpressing hPEBP4 are resistant to both TNFα-induced ERK1/2, MEK1, and JNK activation and TNFα-mediated apoptosis. Co-precipitation andin vitroprotein binding assay demonstrated that hPEBP4 interacts with Raf-1 and MEK1. A truncated form of hPEBP4, lacking the PE-binding domain, maintains lysosomal co-localization but has no effect on cellular responses to TNFα. Given that MCF-7 breast cancer cells expressed hPEBP4 at a high level, small interfering RNA was used to silence the expression of hPEBP4. We demonstrated that down-regulation of hPEBP4 expression sensitizes MCF-7 breast cancer cells to TNFα-induced apoptosis. hPEBP4 appears to promote cellular resistance to TNF-induced apoptosis by inhibiting activation of the Raf-1/MEK/ERK pathway, JNK, and PE externalization, and the conserved region of PE-binding domain appears to play a vital role in this biological activity of hPEBP4.


2017 ◽  
Vol 39 (3) ◽  
pp. 203-211 ◽  
Author(s):  
V F Chekhun ◽  
N Yu Lukianova ◽  
S V Chekhun ◽  
N O Bezdieniezhnykh ◽  
T V Zadvorniy ◽  
...  

Aim: To search for additional molecular-biological markers of cancer stem cell (CSC) involved in the development of intra-tumor heterogeneity for the detection of features of the breast cancer (BC) pathogenesis. Materialts and Methods: Expression of estrogen receptors (ER), progesterone receptors (PR), Her2/neu, E- and N-cadherin, CD24, CD44, Bcl-2, Bax, Slug, P-gp, glutathioneS-transferase (GST) and metallothionein in cell lines was determined by the immunocytochemical method. Expression of ER, PR, Her2/neu, CD24 and CD44 in the surgical material of BC patients were determined by the immunohistochemical method. The levels of the miRNA were determined using real-time polymerase chain reaction. Results: Cells of high-grade malignancy (HGM), MDA-MB-231 and MDA-MB-468 are characterized by high expression of stem cell markers compared to the cells of low-grade malignancy (LGM), T47D and MCF-7: CD44 levels in T47D and MCF-7 cells were in range of 72–79 points, which is significantly lower than in HGM cells (p < 0.05). Also, HGM cells with the properties of CSC were characterized by high expression of antiapoptotic proteins, the transcription factor Slug, and low levels of proapoptotic protein Bax (p < 0.05) compared to LGM cells. In cells with CSC characteristics an increased expression of transferrin and its receptor, ferritin, fentorin and hepcidin was revealed indicating activation of the endogenous iron metabolism. The characteristic feature of HGM cells with CSC phenotype were the increased levels of oncogenic miR-221, -155 and -10b by 60%, 92% and 78%, respectively, and decreased levels of oncosuppressive miR-29b, -34a and -200b by 8.4 ± 0.3, 4.6 ± 0.2, and 3.4 ± 0.6 times compared to MCF-7 line cells. It has been established that the development of resistance to cytostatics is accompanied by increased aggressiveness of tumor cells, loss of expression of hormonal receptors and acquiring of stem phenotype. In particular, increased expression of P-gp was observed in BC cells during the development of resistance to doxorubicin, of GST during the development of resistance to cisplatin along with increased CD44 expression (p < 0.05). We have revealed the relation between the presence of cells with the CSC phenotype (CD44+CD24-/low) and clinical and pathological characteristics of BC patients, their survival and BC sensitivity to neoadjuvant therapy (p > 0.05). Conclusions: The dependence between the expression of CSC markers and the degree of malignancy of tumor cells, development of resistance to cytostatics in vitro was established as well as the predictive value of the detection of the CSC for the individual prognosis of the BC course and sensitivity of the tumors to the treatment.


1995 ◽  
Vol 96 (2) ◽  
pp. 1026-1034 ◽  
Author(s):  
S Scala ◽  
A Budillon ◽  
Z Zhan ◽  
Y S Cho-Chung ◽  
J Jefferson ◽  
...  

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