Human Adenocarcinoma MCF-7 Cells Research Articles

Antiproliferative activity of ruthenium complex II against human cancer cell in vitro

Despite significant advancements in cancer treatment, there is a constant need for new and effective therapeutic options. One such potential weapon in the fight against cancer is ruthenium complex II. In this article, we synthesized, characterized, and studied the activity of dithiocyanato-N-bis[8-(diphenylphosphino)quinoline]ruthenium (II) [Ru(N-P)2(NCS)2] against MCF-7 human adenocarcinoma cells and the MRC-5 cell lines from fetal lung fibroblast-like cells as normal cells, as well as the mechanisms of action and selectivity. This study demonstrated that [Ru(N-P)2(NCS)2] has cytotoxic activity against MCF-7 with IC50 values of 7.56 µg/ml and cytotoxic activity against MRC-5 cell lines with IC50 values of 576.6 µg/ml. [Ru(N-P)2(NCS)2] showed more selective cytotoxic activity against MCF-7 cancer cell lines than MRC-5 normal cell lines. . This study demonstrated the potent apoptotic activity of ruthenium complex II by determining the activation of caspase-3, highlighting its potential as a therapeutic agent in cancer treatment. The [Ru(N-P)2(NCS)2] is considered promising for researchers investigating putative biological activities, particularly antitumor and immune-related activity.

Multi-sensitive functionalized niosomal nanocarriers for controllable gene delivery in vitro and in vivo

MicroRNAs, which can contribute to numerous cellular functions through post-transcriptional silencing, have become well-documented candidates for cancer treatment applications, particularly in chemo-resistant cancers. Herein, several formulations were examined to optimize the essential parameters, and the niosomal formulation consisting of cholesterol:tween-80:DOTAP:PEG with 9:69:15:7 ratio had the best physicochemical parameters including spherical shape, high entrapment efficiency, small diameter (81 ± 0.65 nm), and appropriate positive charge (23 ± 0.64 mV). Here, we aimed to design a system with increased delivery efficiency which was tested by the encapsulation of miR-34a within niosome NPs and assessed the nano-niosomal delivery of miR-34a as a tumor suppressor in MCF-7 human adenocarcinoma cells. The results showed that our novel niosome systems with non-ionic surfactants can successfully eliminate cancer cells by increasing the expression of p53 and reducing the expression of NF-κB. In comparison with the free dispersion of miR-34a, the lysis of a nano-sized delivery system demonstrated a better cytotoxicity effect against cancer cells. Similar results were obtained by performing in vivo test on the 4T1 xenografted Balb/C mouse tumor model and the miR-34a-loaded niosomes displayed a better reduction in tumor size by improving approximately + 13% in tumor inhabitation rate while maintaining the bodyweight close to the first day. Therefore, it is concluded that miR-34a delivery via niosomes has high potential as a tumor suppressor and a reliable procedure for breast cancer treatment.Graphical

Iodine-131 induces cell death by downregulation of antiapoptotic genes in MCF-7 human adenocarcinoma cells

Aims: Radioiodine ( 131 I) is the most common radionuclide which possesses favorable nuclear characteristics for targeted therapy in cancer management. There are several therapeutic radiopharmaceuticals labeled with 131 I used in clinics, but the basic mechanism describing the cause of induced cell death is limited in literature. Hence, the aim of the present study is to find a plausible mechanism of cellular toxicity and involvement of antiapoptotic gene in induction of cell death due to 131 I. Materials and Methods: The effect of 131 I on cell death was studied by incubating MCF-7 cell line with different amount of 131 I radioactivity for 6 h followed by washing and extended the incubation for 48 h. Cells were harvested and cell viability was assessed by lactate dehydrogenase (LDH) release and trypan blue dye uptake. Apoptosis study was carried out with enzyme-linked immunosorbent assay method. Reverse transcriptase polymerase chain reaction was carried out to find expression of antiapoptotic genes, viz., BCL-2 and BCL XL . Results: It was found that release of LDH was Dose and time dependent, and 35% cell death was estimated by trypan blue with 37 MBq of 131 I radioactivity at 48 h of incubation. Enrichment factor of apoptotic DNA was 3.2 with 37 MBq of 131 I at 48 h. Densitometric analysis of BCL-2 and BCL XL showed that there is downregulation of genes expression, which confirmed apoptotic cell death. Conclusions: 131 I induces apoptosis in MCF-7 cell line by the downregulation of antiapoptotic gene BCL-2 and BCL XL when exposed for longer time periods.

Tumor-Specific Peptide, Selected from a Phage Peptide Library, Enhances Antitumor Activity of Lactaptin.

A recombinant analogue of lactaptin (RL2), a new potential anticancer molecule, induces apoptosis in cultured tumor cells. The tumor suppression efficacy of RL2 was shown against mouse hepatoma-1 cells and MDA-MB-231 human breast adenocarcinoma cells. The RL2-based therapeutic drug lactaptin is distributed evenly throughout the organism, which reduces its antitumor efficacy. In the current study, we obtained a genetic construct that allows production of the recombinant fusion protein T3-RL2, consisting of RL2 and T3 peptide (YTYDPWLIFPAN), in E. coli cells. T3 peptide was selected from a phage peptide library as a result of two screenings: in vitro using MDA-MB-231 cell culture and in vivo using a mouse xenograft model of breast cancer MDA-MB-231. It was shown that the displayed peptide T3 provides binding and internalization of phage particles by MDA-MB-231 cells and their specific accumulation in MDA-MB-231 tumor tissue. In addition, based on the nucleotide sequences coding RL2 and the known tumor-targeting peptide iRGD, we obtained genetic constructs that provide synthesis of fusion proteins RL2-iRGD and RL-iRGD-His. We studied the cytotoxic activity of fusion proteins T3-RL2, RL2-iRGD and RL-iRGD-His in vitro using MDA-MB-231 and MCF-7 human adenocarcinoma cells. The in vitro results showed that the fusion proteins inhibit proliferation of both cell cultures, and their cytotoxic activity is higher than that of RL2. In vivo experiments on the study of the antitumor efficacy of the obtained fusion proteins demonstrated that T3-RL2 protein significantly inhibits MDA-MB-231 tumor growth in a xenograft model compared with RL2, while the antitumor effect of RL2-iRGD and RL-iRGD-His proteins is comparable to the effect of RL2.

Artificial Analogues of Circulating Box C/D RNAs Induce Strong Innate Immune Response and MicroRNA Activation in Human Adenocarcinoma Cells.

Fragments of small nucleolar RNAs (snoRNAs) were found among various non-coding RNAs (ncRNAs) circulating in human blood. Currently, the function of such cell-free sno-derived-RNAs is not clearly defined. This work is aimed at identifying regulatory pathways controlled by extracellular snoRNAs. In order to determine the molecular targets and pathways affected by artificial snoRNAs, we performed Illumina array analysis of MCF-7 human adenocarcinoma cells transfected with box C/D RNAs. The genes related to the innate immune response and apoptotic cascades were found to be activated in transfected cells compared with control cells. Intriguingly, the transfection of MCF-7 cells with artificial box C/D snoRNAs also increased the transcription of several microRNAs, such as mir-574, mir-599 and mir-21. Our data demonstrated that extracellular snoRNAs introduced into human cells may function as gene expression modulators, with activation of microRNA genes being one of the regulatory mechanisms.

The influence of recombinant nucleophosmin 1 on artificial RNA internalization into human adenocarcinoma MCF-7 cells

In this study we obtained and characterized the recombinant analogue of multifunctional nucleolar phosphoprotein nucleophosmin 1 (NPM1) involved in crucial cellular processes such as transcription, reparation and mitosis. The influence ofnucleophosmin 1 on extrcellular RNAs accumulation in human adenocarcinoma cells MCF-7 was analyzed. It was found that incubation of AluY RNA (n > 300 nt), U24 snoRNA analogues (n ~ 80 nt) with Npm1-His6 resulted in RNA-protein non-covalent complexes formation, but not in case of the short oligoribonucleotide (n = 22 nt). It was shown that interaction of AluY RNA analogue with Npm1-His6 significantly increases transfection efficacy of the RNA into MCF-7 human cells. Altogether, these data allow us to conclude, that nucleophosmin 1 not only binds RNA with complex secondary structure, but also promotes uptake and internalization of such RNA by human cells.

Deamination of Adenosines in Extracellular RNA Spontaneously Internalized by Human Cells

Ribonucleic acids circulating in mammalian extracellular fluids as well as RNAs accumulating in culture medium condensed by mammalian cells are internalized by acceptor cells and distributed among cellular compartments. The internalized RNA can be involved in the induction and regulation of cellular processes as guide or signaling molecules. The internalization of RNA may be accompanied by covalent modifications influencing the stability and functionality of this RNA. To analyze nucleotide modifications introduced by human cells in internalized extracellular RNA, 5.8S rRNA of S. cerevisiae was used. It was shown that 5.8S rRNA of S. cerevisiae is captured by human adenocarcinoma MCF-7 cells from culture medium and delivered to cytoplasm and nuclei. Most of the internalized RNA was hydrolyzed to mono- and oligonucleotides. Full-length RNA uptake was detected by RT-PCR in the cytoplasm and in nuclei after the pulse addition of RNA to the culture medium. 5'-Inosine was the only detectable modified nucleotide in the hydrolysate of cell-internalized RNAs. Consequently, extracellular RNAs entering human cells were subjected to partial adenosine deamination. Sequencing of cDNA confirmed that full-length extracellular RNA that accumulated in the nucleus, but not in the cytoplasm, was partially edited by adenosine deaminases. The deamination revealed in nuclear-stored, full-length RNA was site-specific. Adenosines edited in S. cerevisiae 5.8S rRNA are stack-closing A-U pairs A53 and A96, as well as unpaired A44 and A65. Our data emphasize the participation of adenosine deaminases in capturing and intracellular trafficking of internalized RNAs.

Endoplasmic reticulum and Golgi apparatus are the preferential sites of Foscan localisation in cultured tumour cells.

Intracellular photosensitiser localisation significantly influences the mechanism of response to photodynamic therapy (PDT), since the primary sites of damage are closely related to the specific sensitiser distribution. Foscan® subcellular localisation in the MCF-7 human adenocarcinoma cell line has been studied by means of confocal microscopy and microspectrofluorometry. The fluorescence topographic profiles recorded after cells costained with Foscan® and organelle-specific fluorescent probes revealed that Foscan® presents low localisation in lysosomes and a weak accumulation in mitochondria. Alternatively, the Foscan® fluorescence topographic profile turned out to colocalise perfectly with that obtained for the endoplasmic reticulum (ER) and the Golgi apparatus. The patterns of fluorescence derived from confocal microscopy studies were consistent with predominant localisation of Foscan® in these organelles. Furthermore, evaluation of enzymatic activity of selected organelles immediately after laser light irradiation (650 nm) indicated the Golgi apparatus and ER as the primary damaged sites resulting from Foscan®-mediated PDT in the MCF-7 cell line. To our knowledge, this is the first study to demonstrate unambiguously that the ER and the Golgi apparatus are preferential sites of Foscan® accumulation.

Localization of a Negative Vitamin D Response Sequence in the Human Growth Hormone Gene

1,25-Dihydroxyvitamin D3 [1,25(OH)2 D3] exerts its biological effects by binding to the vitamin D receptor (VDR), which binds in turn to the vitamin D response elements located in the target gene's promoter. We have previously demonstrated that VDR binds in vitro with high affinity to the 5′-flanking sequence of the human growth hormone (hGH) gene. In this study, we analyzed the response to 1,25(OH)2 D3 of hGH-promoter constructs introduced by transfection into the MCF-7 human adenocarcinoma cell line. We found that the transcriptional activity of some of these constructs was markedly reduced by 1,25(OH)2 D3. Deletion analyses revealed that a 34-bp sequence located between positions −62 and −29 upstream of the transcription start site is sufficient for this repressive response. This conclusion was also confirmed by gel mobility shift assays. Our results indicate that vitamin D inhibits hGH gene transcription, directly or by interference with other transcription factors.