MCF-7 Cells Research Articles

Azobenzene-Tagged Photopeptides Exhibiting Excellent Selectivity and Light-Induced Cytotoxicity in MCF-7 Cells over HeLa and A549.

The precise regulation of proteasome activity has become a focal point in current research, particularly its implications in cancer treatment. Bortezomib is used for treating multiple myeloma and is found to be ineffective against solid tumors. A spatiotemporal control over the proteasome is one of the solutions to resolve these issues using external stimuli, such as light. Thus, we designed and synthesized azobenzene-containing tripeptide vinyl sulfones 1, 2, 3, and 4, as the azobenzene moiety can impart E↔Z isomerism upon exposure to UV light. Further, the hydrophobicity of these peptides was fine-tuned by systematically varying the size of hydrophobic amino acids at the P1, P2, and P3 positions. The light-induced Z isomers of these photopeptides showed excellent cellular potency in HeLa, MCF-7, and A549 cell lines. Photopeptide 4 with valine at the proximal position, phenylalanine at P2, and leucine at the P1 positions exhibited 19.3- and 6.6-fold cellular potency in MCF-7 and A549 cells, respectively.

Signature analysis of high-throughput transcriptomics screening data for mechanistic inference and chemical grouping.

High-throughput transcriptomics (HTTr) uses gene expression profiling to characterize the biological activity of chemicals in in vitro cell-based test systems. As an extension of a previous study testing 44 chemicals, HTTr was used to screen an additional 1,751 unique chemicals from the EPA's ToxCast collection in MCF7 cells using 8 concentrations and an exposure duration of 6 h. We hypothesized that concentration-response modeling of signature scores could be used to identify putative molecular targets and cluster chemicals with similar bioactivity. Clustering and enrichment analyses were conducted based on signature catalog annotations and ToxPrint chemotypes to facilitate molecular target prediction and grouping of chemicals with similar bioactivity profiles. Enrichment analysis based on signature catalog annotation identified known mechanisms of action (MeOAs) associated with well-studied chemicals and generated putative MeOAs for other active chemicals. Chemicals with predicted MeOAs included those targeting estrogen receptor (ER), glucocorticoid receptor (GR), retinoic acid receptor (RAR), the NRF2/KEAP/ARE pathway, AP-1 activation, and others. Using reference chemicals for ER modulation, the study demonstrated that HTTr in MCF7 cells was able to stratify chemicals in terms of agonist potency, distinguish ER agonists from antagonists, and cluster chemicals with similar activities as predicted by the ToxCast ER Pathway model. Uniform manifold approximation and projection (UMAP) embedding of signature-level results identified novel ER modulators with no ToxCast ER Pathway model predictions. Finally, UMAP combined with ToxPrint chemotype enrichment was used to explore the biological activity of structurally related chemicals. The study demonstrates that HTTr can be used to inform chemical risk assessment by determining in vitro points of departure, predicting chemicals' MeOA and grouping chemicals with similar bioactivity profiles.

Resveratrol inhibits Cell Cycle Dynamics, Caspase Activation, and Programmed Cell Death: Implications for Cancer Treatment in MCF-7 Cells"

Resveratrol inhibits Cell Cycle Dynamics, Caspase Activation, and Programmed Cell Death: Implications for Cancer Treatment in MCF-7 Cells"

Novel benzenesulfonamide-aroylhydrazone conjugates as carbonic anhydrase inhibitors that induce MAPK/ERK-mediated cell cycle arrest and mitochondrial-associated apoptosis in MCF-7 breast cancer cells

A series of novel 4-alkylthio-2-chloro-5-[(2-arylmethylidene)hydrazinecarbonyl]benzenesulfonamide derivatives 3–22 were synthesized and evaluated for their inhibitory activity against human carbonic anhydrase isozymes hCA I, hCA II, hCA IX, and hCA XII. These compounds showed varying degrees of activity against the studied isoenzymes. However, the importance of substituent choice in designing potent carbonic anhydrase inhibitors is highlighted by the strong inhibition profiles of compounds 3 and 10 against hCA IX and the low average KI values for compounds 9 and 10 (134 nM and 77 nM, respectively). All the synthesized compounds were evaluated for their antiproliferative activity toward HeLa, HCT-116, and MCF-7 cell lines. Compounds 9 and 19 exhibited significant activity, particularly against the MCF-7 cell line (IC50 values of 4 μM and 6 μM, respectively). Notably, compound 9 demonstrated a high selectivity index (SI = 8.2) for MCF-7 cells. The antiproliferative effects of compounds 9 and 19 were linked to the induction of cell cycle arrest and apoptosis via the mitochondrial pathway and involved the activation of the MAPK/ERK signaling pathway. Inhibition of MAPK/ERK activity reduced the compounds’ ability to induce cell cycle arrest and apoptosis, indicating the critical role of this pathway. These findings suggest that compounds 9 and 19 are promising candidates for further development as specific and potent anticancer agents targeting the MAPK/ERK pathway.

Novel RGD-Decorated Micelles Loaded with Doxorubicin for Targeted Breast Cancer Chemotherapy

Nanotechnology has emerged as a promising innovative avenue for therapeutic intervention in cancer research. However, achieving satisfactory accumulation of nanoparticles in the tumor and fabricating optimized nanoparticles remain challenging. In this work, we developed a novel polymeric micelle system to actively target integrin receptors, which are usually overexpressed in breast cancer. We first synthesized a targeted peptide-modified cyclic (Arg-Gly-Asp-D-Phe-Cys) (c(RGDfc))-polyethylene glycol-acitretin amphipathic conjugate (RPA) and prepared doxorubicin (DOX)-loaded RPADm (RPA@DOX) micelles with a high drug loading content of more than 11%. Compared with unmodified DOX-containing micelles, RPADm demonstrated increased cytotoxicity and cellular uptake by MCF-7 cells. Importantly, competitive binding experiments confirmed that the observed enhancement effect was attributed to the modification of c(RGDfc) on the surface of the micelles. Furthermore, due to its active tumor-targeting ability, compared with the other DOX-based formulations, the RPADm exhibited the highest tumor distribution and strongest therapeutic efficacy in MCF-7 tumor-bearing nude mice. Additionally, the safety evaluation experiments revealed that the DOX-loaded micelles had no obvious systemic toxicity. These results suggest that the developed micelles modified with c(RGDfc) are promising candidates for tumor-active targeting therapies.

Differential Effects of Punicic Acid on Cytotoxicity and Peroxiredoxin Expression in MCF-7 Breast Cancer and MCF-10A Normal Cells.

The pomegranate fruit has been associated with a variety of human health benefits based on its antioxidant and anti-inflammatory properties. Punicic acid (PA) is an omega-5 long chain polyunsaturated fatty acid that constitutes approximately 65-80% of the oil from pomegranate seeds and has been found to possesses anti-cancer activity in various cancer types. To better understand its cell specificity, we investigated the effects of punicic acid on both the MCF-7 human breast cancer cell line as well as the non-cancerous MCF-10A breast epithelial line. We treated both cell types with different concentrations of punicic acid and measured viable cell density, cytotoxicity and apoptosis, as well as peroxiredoxin (Prdx) antioxidant expression. We found that punicic acid was cytotoxic to both lines, but MCF-10A cells demonstrated higher levels of cytotoxicity and sensitivity to lower concentrations. We further demonstrated that cytotoxicity was associated with apoptosis in both lines. Using real time PCR, we demonstrated induction of all six Prdx mRNAs in MCF-7 cells, ranging from a 1.4-fold increase with 2 μg/ml, to over a 5-fold increase with 10 μg/ml. In stark contrast, MCF-10A cells exhibited considerably higher induction of all six Prdx mRNAs at 10μg/ml, exceeding a 30-fold induction of Prdx1, Prdx2 and Prdx5. Our data are the first to demonstrate differential cytotoxicity and Prdx regulation by punicic acid in these two cell lines. These results may provide important insight into cell-specific mechanisms of punicic acid in breast cancer.

A novel quinazoline derivative exhibits potent anticancer cytotoxicity via apoptosis and inhibition of angiogenesis in DMBA-induced mammary gland carcinoma.

Mammary gland carcinoma is one of the most prevalent and deadly diseases among women globally. It is a type of solid malignant tumor. In this malignant tumor, the microenvironment becomes hypoxic in rapidly proliferating cancer cells. These cells undergo adaptive changes through the expression of hypoxia-inducible factor-1alpha (HIF-1α) which is regulated by factor inhibiting HIF-1α (FIH-1). Considering this, we hypothesized that the chemical activation of FIH-1 would inhibit the hypoxic activity of HIF-1α in mammary gland carcinoma. A library of 67,609 chemical compounds was virtually screened against FIH-1 based on Lipinski's rule from the ZINC database. The BBAP-8 has been selected based on an excellent docking score (-8.352 Kcal/mol), favorable ADMET, and potential FIH-1 activator profile. Further, its in-vitro cytotoxicity and apoptotic activity were scrutinized against MCF-7 cells and in-vivo activity against 7,12-dimethylbenz[a]anthracene (DMBA) induced mammary gland carcinoma in Wistar rats. It exhibited significant cytotoxicity (IC50 = 16.59 ± 0.49 μM) and activated apoptosis when scrutinized through DAPI, AO/EB, and JC-1 staining. Also, oral administration of BBAP-8 restored hemodynamic changes, normalized tissue architecture, and corrected metabolic abnormalities. The western blot analysis and mRNA expression analysis validated that BBAP-8 has the potential to activate FIH-1 with the downregulation of GLUT-1, VEGF, and Twist-1. Moreover, BBAP-8 fostered apoptosis, when evaluated through BCL-2, BAX, Caspase-8, and Caspase-3. Based on research findings, this implies that BBAP-8 activates FIH-1 and can be effective in chemotherapeutic treatment of mammary gland carcinoma.

Discovery and Development of HDAC Inhibitors: Approaches for the Treatment of Cancer a Mini-review.

Histone deacetylase (HDAC) inhibitors have emerged as promising cancer therapeutics due to their ability to induce differentiation, cell cycle arrest, and apoptosis in cancer cells. In the present review, we have described the systemic discovery and development of HDAC inhibitors. Researchers across the globe have identified various small molecules like benzo[d][1,3]dioxol derivatives, belinostat analogs, pyrazine derivatives, quinazolin-4-one-based derivatives, 2,4-imidazolinedione derivatives, acridine hydroxamic acid derivatives, coumarin derivatives, tetrahydroisoquinoline derivatives, thiazole-5-carboxamide, salicylamide derivatives, β-peptoid-capped HDAC inhibitors, quinazoline derivatives, benzimidazole and benzothiazole derivatives, and β- elemene scaffold containing HDAC inhibitors. Most of the scaffolds have shown attractive IC50 (μM) in various cell lines like HDAC1, HDAC2, HDAC6, PI3K, HeLa, MDA-MB-231, MCF-10A, MCF-7, U937, K562 and Bcr-Abl cell lines.

Uncovering the therapeutic potential of green pea waste in breast cancer: a multi-target approach utilizing LC-MS/MS metabolomics, molecular networking, and network pharmacology

Background Pisum sativum(PS) is a universal legume plant utilized for both human and animal consumption, particularly its seeds, known as green peas. The processing of PS in food industries and households produces a significant amount of waste that needs to be valorized.MethodsIn this study, the metabolite profiles of the 70% ethanolic extracts of PS wastes, namely peels (PSP) and a combination of leaves and stems (PSLS), were investigated by liquid chromatography-electrospray ionization-quadrupole time-of-flight tandem mass spectrometry (LC-ESI-QTOF-MS/MS) followed by molecular networking.ResultsDifferent classes of metabolites were identified, being flavonoids and their derivatives, along with phenolic acids, the most abundant categories. Additionally, a comprehensive network pharmacology strategy was applied to elucidate potentially active metabolites, key targets, and the pathways involved in cytotoxic activity against breast cancer. This cytotoxic activity was investigated in MCF-7 and MCF-10a cell lines. Results revealed that PSLS extract exhibited a potent cytotoxic activity with a good selectivity index (IC50 = 17.67 and selectivity index of 3.51), compared to the reference drug doxorubicin (IC50 = 2.69 µg/mL and selectivity index of 5.28). Whereas PSP extract appeared to be less potent and selective (IC50 = 32.92 µg/mL and selectivity index of 1.62). A similar performance was also observed for several polyphenolics isolated from the PSLS extract, including methyl cis p-coumarate, trans p-coumaric acid, and liquiritigenin/ 7-methyl liquiritigenin mixture. Methyl cis p-coumarate showed the most potent cytotoxic activity against MCF-7 cell line and the highest selectivity (IC50 = 1.18 µg/mL (6.91 µM) and selectivity index of 27.42). The network pharmacology study revealed that the isolated compounds could interact with several breast cancer-associated protein targets including carbonic anhydrases 1, 2, 4, 9, and 12, as well as aldo-keto reductase family 1 member B1, adenosine A3 receptor, protein tyrosine phosphatase non-receptor type 1, and estrogen receptor 2.ConclusionThe uncovered therapeutic potential of PSLS and its metabolite constituents pave the way for an efficient and mindful PS waste valorization, calling for further in-vitro and in-vivo research.Graphical

Fluorescent Microscopy Investigation of Cytotoxic Impact on MCF-7 Cell Line Treated With Zinc Nanoparticles Synthesized From Jania rubens.

Zinc nanoparticles (ZnNPs) are a viable option in a number of disciplines, including cancer treatment, due to their special features. Among the several techniques for synthesizing ZnNP, biosynthesis with natural extracts is a highly effective and environmentally benign method, especially for uses in biomedicine. Using an aqueous extract of the marine red seaweed Jania rubens, we created a unique biosynthetic technique in this study to manufacture ZnNPs. The produced ZnNPs have a characteristic flower-like form, as seen by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effective production of ZnNPs and the involvement of biomolecules in the synthesis process were validated by energy-dispersive X-ray spectroscopy (EDAX) and Fourier transform infrared spectroscopy (FTIR) techniques. Using the MTT assay, the cytotoxic effects of the biosynthesized ZnNPs were evaluated, indicating their ability to inhibit MCF-7 breast cancer cells. Furthermore, ZnNPs' cytotoxicity against MCF-7 cells was validated by live/dead imaging experiments, which supported the MTT results.

Evaluation of Antioxidant and Breast Cancer Cytotoxicity of Beta vulgaris and Daucus carota Methanol Extracts

Breast cancer is the world's most frequent malignancy among women. Many dietary antioxidants have been shown to help prevent oxidative stress, which has been linked to a variety of diseases, including cancer. Many chronic diseases, such as cancer, can be avoided by eating fruits and vegetables on a regular and balanced basis. The current study's goal is to assess the antioxidant and cytotoxic capabilities of methanolic extracts of Beta vulgaris and Daucus carota against MCF-7 human breast cancer cell lines. Therefore, the aim of the present study was to determine the phytochemical components, antioxidant capacity, total phenolic & flavonoid contents in the methanolic extracts of Beta vulgaris and Daucus carota. Further, MTT assay against breast cancer cell line (MCF-7) was performed for the evaluation of cytotoxic activity. The majority of secondary metabolites were found in both the aqueous and methanolic extracts of Beta vulgaris and Daucus carota. Beta vulgaris and Daucus carota have different total phenolic and flavonoid contents. TLC results showed many spots having different Rf values. Moreover, we observe comparable cytotoxic activity in both the extracts against MCF-7 cell lines. Our results reveal that the methanolic extracts of Beta vulgaris and Daucus carota has effective phytochemical constituents, antioxidant and anticancer activity. The total phenolic and flavonoid contents vary between Beta vulgaris and Daucus carota. Further studies are needed to evaluate the chemopreventive potentials of the Beta vulgaris and Daucus carota extract when used alone or in combination with doxorubicin to mitigate the toxic side-effects of the latter.

TNF-ɑ induces mitochondrial dysfunction to drive NLRP3/Caspase-1/GSDMD-mediated pyroptosis in MCF-7 cells

Pyroptosis is a gasdermin-mediated pro-inflammatory form of programmed cell death (PCD). Tumor necrosis factor-ɑ (TNF-ɑ) is an inflammatory cytokine, and some studies have shown that TNF-ɑ can cause pyroptosis of cells and exert anti-tumor effects. However, whether TNF-ɑ exerts anti-tumor effects on breast cancer cells by inducing pyroptosis has not been reported. In this study, to explore the impact of TNF-ɑ on pyroptosis in breast cancer cells, we treated MCF-7 cells with TNF-ɑ and found that TNF-ɑ induced cell death. Moreover, we observed that the dead cells were swollen with obvious balloon-like bubbles, which was a typical sign of pyroptosis. Further studies have found that the anti-tumor effect of TNF-ɑ on breast cancer cells in vitro was achieved through the canonical pyroptosis pathway. In addition, TNF-ɑ-induced pyroptosis in MCF-7 cells was associated with mitochondrial dysfunction, in which mitochondrial membrane potential was decreased and mitochondrial ROS production was increased. After inhibiting ROS production, the activation effect of TNF-ɑ on NLRP3/Caspase-1/GSDMD pathway was weakened, and the inhibitory effect of TNF-ɑ on the growth of MCF-7 cells in vitro was also decreased, further confirming the involvement of ROS in TNF-ɑ-induced pyroptosis. Overall, our study revealed a new mechanism by which TNF-ɑ exerts an anti-tumor effect by inducing pyroptosis in MCF-7 cells through the ROS/NLRP3/Caspase-1/GSDMD pathway, which may provide new therapeutic ideas for the treatment of breast cancer.

New Chlorine-Containing Sesquiterpenoid from Artemisia Blepharolepis.

One new chlorinated sesquiterpenoid (compound 1, ablepharolide) and twenty-one known compounds were obtained from the aerial parts of Artemisia blepharolepis. Their structures were established by spectroscopic methods and the absolute configuration was further determined by single-crystal X-ray diffraction analysis for ablepharolide. Ablepharolide is a rare sesquiterpenoid with a 4-methyl-7-isopropyl-9-ethyl-perhydroindene skeleton that incorporates a chlorine atom. It significantly inhibited the growth of MCF-7 cells with IC50 value of 8.34±0.77 μM. Further investigations demonstrated that ablepharolide induced morphological changes in MCF-7 cells, inhibited proliferation in a time- and dose-dependent manner. Furthermore, western blot analysis revealed that ablepharolide induced a significant increase in cleaved caspase-8, cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP) in MCF-7 cells. All of these results supported that ablepharolide induced exogenous apoptosis in MCF-7 cells.

PH-responsive magnetic CuFe2O4-PMAA nanogel conjugated with amino-modified lignin for controlled breast cancer drug delivery

In this study, a novel magnetic and pH-responsive nanocarrier was developed, incorporating both natural and synthetic polymers, for delivering curcumin (CUR) to breast cancer cells. For this purpose, CuFe2O4@poly(methacrylic acid) (CuFe2O4@PMAA) nanogel was developed and conjugated with amino-modified lignin (Lignin-adipic acid dihydrazide conjugate, Lig-ADH) to achieve the CuFe2O4@PMAA@Lig-ADH nanocarrier. The morphology, structure, and physical properties of the synthesized nanomaterials were examined using a range of techniques, including transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray (EDX), and vibrating sample magnetometer (VSM). The synthesized nanocarrier exhibited a spherical shape, with an average diameter of approximately 15 nm, and demonstrated good magnetic responsiveness. Moreover, the in vitro drug release was found to be pH-dependent, with an increased release rate in acidic conditions. To evaluate cytotoxicity, the survival of MCF-7 cells was measured using the MTT assay for 24 h. Notably, the synthesized CuFe2O4@PMAA@Lig-ADH@CUR and CUR exhibited significant cytotoxic effects, effectively eliminating MCF-7 cells with IC50 values of 39.80 µg/mL and 4.27 µg/mL, respectively. Also, the significant intracellular uptake of NPs was confirmed by FITC and DAPI staining after 4 h. This research highlighted the potential of CuFe2O4@PMAA@Lig-ADH@CUR as a highly effective nano-delivery system and demonstrated a straightforward method for utilizing renewable lignin.

N-[4-(Benzyloxy)-3-methoxybenzyl)]adamantane-1-amine (DZH2), a dual CCR5 and CXCR4 inhibitor as a potential agent against triple negative breast cancer.

DZH2, a dual inhibitor of the chemokine receptors CCR5 and CXCR4, was discovered from virtual screening for CCR5 antagonists. In specific Ca2+ chemokine signaling assays, DZH2 displayed low micromolar IC50 values at both chemokine receptors. Its binding to intracellular allosteric binding sites of CCR5 and CXCR4 was confirmed by MD simulations and binding free-energy calculations. DZH2 is superior to the CCR5 antagonist maraviroc in terms of its inhibitory activity on the growth of two breast cancer cell lines. In MCF7 and MDA-MB-231 cells, DZH2 was a >100-fold more potent inhibitor of cell viability compared to maraviroc. DZH2 (6.7 µM) reduced migration of MDA-MB-231 cells to 4% compared to 50% inhibition of migration caused by maraviroc (780 µM). Also, DZH2 was a significantly more potent inhibitor of colony formation in MDA-MB-231 cells than maraviroc. In MCF10 cells, DZH2 caused no alteration in the gene expression with respect to cellular pathways mediating cell death, indicating its selectivity to breast cancer cells.

Investigation of Apoptotic and Anticancer Effects of 2-substituted Benzothiazoles in Breast Cancer Cell Lines: EGFR Modulation and Mechanistic Insights.

Benzothiazole derivatives, a class of heterocyclic compounds, exhibited diverse biological activities influenced by substituents in the thiazole ring. This study aimed to synthesize these compounds with two functional groups to investigate their potential as anticancer agents, particularly against breast cancer. While previous research demonstrated the efficacy of 2-substituted benzothiazoles against glioma and cervical and pancreatic cancer cells, there is a gap in studies targeting breast cancer. The synthesized compounds were tested in vitro using MCF-7, MDA-MB-231, and MCF-10A cell lines, with Doxorubicin as the positive control. Various assays were conducted, including Annexin V/PI, cell cycle analysis, wound healing, and measurement of mitochondrial membrane potential. Protein expression of EGFR and transcription levels of apoptosis-related genes (Bax and Bcl-xL) and cancer progression-related genes (JAK, STAT3, ERK, AKT, mTOR) were analyzed. Additionally, the balance between antioxidants and oxidants was evaluated by measuring TAS and TOS levels. Our findings revealed that benzothiazole compounds significantly inhibited breast cancer cell growth by reducing cell motility, disrupting mitochondrial membrane potential, and inducing cell cycle arrest in the sub-G1 phase. These compounds increased reactive oxygen species accumulation, leading to cell death. Furthermore, they decreased EGFR protein levels, increased Bax gene transcription, and downregulated the expression of genes such as JAK, STAT3, ERK, AKT, and mTOR. In conclusion, benzothiazole derivatives exhibited potent inhibitory effects on breast cancer in vitro by promoting apoptosis, downregulating EGFR activity, and modulating key signaling pathways, including JAK/STAT, ERK/MAPK, and PI3K/Akt/mTOR. These results highlighted the potential of benzothiazole derivatives as novel therapeutic agents for breast cancer treatment.

Increased MAGE-C Family Gene Expression Levels as a Biomarker of Colon Cancer Through the Demethylation Mechanism

Background/Objectives: Colon cancer (CC) in Saudi Arabia is associated with a high death rate and is commonly identified at a more progressive stage. Therefore, it is critical to identify and characterize potential novel cancer-specific biomarkers to enhance early CC diagnosis. The goal was to assess their potential use as cancer biomarkers for the early detection and improvement of CC treatment. Methods: MAGE-C1, MAGE-C2, and MAGE-C3 family gene expression levels were examined using RT-PCR and qRT-PCR assays in 26 adjacent normal colon (NC) and CC tissue samples from male and female Saudi patients. Using several cell lines and the qRT-PCR technique, epigenetic control was also investigated to determine whether reduced treatment with 5-aza-2′-deoxycytidine, which reduces DNA methyltransferase, can increase the expression of the MAGE-C gene. The expression levels, promoter methylation, and prognostic significance of MAGE-C1, MAGE-C2, and MAGE-C3 genes across various cancers were analyzed using The Cancer Genome Atlas (TCGA) data. Additionally, the prognostic significance of these genes was assessed through Kaplan–Meier survival analysis. Results: The RT-PCR results showed that MAGE-C1, MAGE-C2, and MAGE-C3 gene expressions were significantly higher in the CC and NC tissues. The MAGE-C1 expression level was the highest in CC tissues (p < 0.0001), followed by MAGE-C3 (p = 0.0004) and MAGE-C2 (p = 0.0020) in descending order. The 5-aza-2′-deoxycytidine treatment significantly increased the mRNA expression levels of the MAGE-C1, MAGE-C2, and MAGE-C3 genes in HCT116, Caco-2, MCF-7, and MCF-10A cells. Expression analyses of TCGA samples revealed significant upregulation of these genes in several cancer types, with notable differences between normal, tumor, and metastatic tissues. Promoter methylation indicates hypomethylation in cancerous tissues. Survival analyses show that high expression levels of MAGE-C1 correlate with better prognosis, while MAGE-C3 is associated with poorer outcomes. Conclusions: These results demonstrate that MAGE-C genes are viable prospective biomarkers of CC controlled by hypomethylating drugs, consequently offering a possible treatment target for CC in a specific population.

Beyond endocrine resistance: estrogen receptor (ESR1) activating mutations mediate chemotherapy resistance through the JNK/c-Jun MDR1 pathway in breast cancer.

All patients with metastatic breast cancer (MBC) expressing estrogen receptor-α (ESR1) will eventually develop resistance to endocrine therapies. In up to 40% of patients, this resistance is caused by activating mutations in the ligand-binding domain (LBD) of ESR1. Accumulating clinical evidence indicate adverse outcomes for these patients, beyond that expected by resistance to endocrine therapy. Here we aimed to study the role of ESR1 mutations in conferring chemoresistance in BC cells. MCF-7 cells harboring Y537S and D538G ESR1 mutations (mut-ER) were employed to study the response to chemotherapy drugs, paclitaxel and doxorubicin, using viability and apoptotic assay in vitro, and tumor growth in vivo. JNK/c-Jun/MDR1 pathway was studied using qRT-PCR, western-blot, gene-reporter and ChIP assays. MDR1 expression was analyzed in clinical samples using IHC. Cell harboring ESR1 mutations displayed relative chemoresistance compared to WT-ER, evidenced by higher viability and reduced apoptosis as well as resistance to paclitaxel in vivo. To elucidate the underlying mechanism, MDR1 expression was examined and elevated levels were observed in mut-ER cells, and in clinical BC samples. MDR1 is regulated by the c-Jun pathway, and we showed high correlation between these two genes in BC using TCGA databases. Accordingly, we detected higher JNK/c-Jun expression and activity in ESR1-mutated cells, as well as increased occupancy of c-Jun in MDR1 promoter. Importantly, JNK inhibition decreased MDR1 expression and restored sensitivity to chemotherapy. Taken together, these data indicate that ESR1 mutations confer chemoresistance through activation of the JNK/MDR1 axis. These finding suggest a novel treatment option for BC tumors expressing ESR1 mutations.

Transcriptional responses to direct and indirect TGFB1 stimulation in cancerous and noncancerous mammary epithelial cells

BackgroundTransforming growth factor beta (TGFβ) is important for the morphogenesis and secretory function of the mammary gland. It is one of the main activators of the epithelial–mesenchymal transition (EMT), a process important for tissue remodeling and regeneration. It also provides cells with the plasticity to form metastases during tumor progression. Noncancerous and cancer cells respond differently to TGFβ. However, knowledge of the cellular signaling cascades triggered by TGFβ in various cell types is still limited.MethodsMCF10A (noncancerous, originating from fibrotic breast tissue) and MCF7 (cancer, estrogen receptor-positive) breast epithelial cells were treated with TGFB1 directly or through conditioned media from stimulated cells. Transcriptional changes (via RNA-seq) were assessed in untreated cells and after 1–6 days of treatment. Differentially expressed genes were detected with DESeq2 and the hallmark collection was selected for gene set enrichment analysis.ResultsTGFB1 induces EMT in both the MCF10A and MCF7 cell lines but via slightly different mechanisms (signaling through SMAD3 is more active in MCF7 cells). Many EMT-related genes are expressed in MCF10A cells at baseline. Both cell lines respond to TGFB1 by decreasing the expression of genes involved in cell proliferation: through the repression of MYC (and the protein targets) in MCF10A cells and the activation of p63-dependent signaling in MCF7 cells (CDKN1A and CDKN2B, which are responsible for the inhibition of cyclin-dependent kinases, are upregulated). In addition, estrogen receptor signaling is inhibited and caspase-dependent cell death is induced only in MCF7 cells. Direct incubation with TGFB1 and treatment of cells with conditioned media similarly affected transcriptional profiles. However, TGFB1-induced protein secretion is more pronounced in MCF10A cells; therefore, the signaling is propagated through conditioned media (bystander effect) more effectively in MCF10A cells than in MCF7 cells.ConclusionsEstrogen receptor-positive breast cancer patients may benefit from high levels of TGFB1 expression due to the repression of estrogen receptor signaling, inhibition of proliferation, and induction of apoptosis in cancer cells. However, some TGFB1-stimulated cells may undergo EMT, which increases the risk of metastasis.

Transcriptomic analysis of cellular senescence induced by ectopic expression of ATF6α in human breast cancer cells.

The transcriptomic profile of cellular senescence is strongly associated with distinct cell types, the specific stressors triggering senescence, and temporal progression through senescence stages. This implies the potential necessity of conducting separate investigations for each cell type and a stressor inducing senescence. To elucidate the molecular mechanism that drives endoplasmic reticulum (ER) stress-induced cellular senescence in MCF-7 breast cancer cells, with a particular emphasis on the ATF6α branch of the unfolded protein response. We conducted transcriptomic analysis on MCF-7 cells by ectopic expression of ATF6α. Transcriptomic sequencing was conducted on MCF-7 cells at 6 and 9 hours post senescence induction through ATF6α ectopic expression. Comprehensive analyses encompassing enriched functional annotation, canonical pathway analysis, gene network analysis, upstream regulator analysis and gene set enrichment analysis were performed on Differentially Expressed Genes (DEGs) at 6 and 9 hours as well as time-related DEGs. Regulators and their targets identified from the upstream regulator analysis were validated through RNA interference, and their impact on cellular senescence was assessed by senescence-associated β-galactosidase staining. ATF6α ectopic expression resulted in the identification of 12 and 79 DEGs at 6 and 9 hours, respectively, employing criteria of a false discovery rate < 0.05 and a lower fold change (FC) cutoff |log2FC| > 1. Various analyses highlighted the involvement of the UPR and/or ER Stress Pathway. Upstream regulator analysis of 9 hour-DEGs identified six regulators and eleven target genes associated with processes related to cytostasis and 'cell viability and cell death of connective tissue cells.' Validation confirmed the significance of MAP2K1/2, GPAT4, and PDGF-BB among the regulators and DDIT3, PPP1R15A, and IL6 among the targets. Transcriptomic analyses and validation reveal the importance of the MAP2K1/2/GPAT4-DDIT3 pathway in driving cellular senescence following ATF6α ectopic expression in MCF-7 cells. This study contributes to our understanding of the initial molecular events underlying ER stress-induced cellular senescence in breast cancer cells, providing a foundation for exploring cell type- and stressor-specific responses in cellular senescence induction.