Ruxolitinib-loaded poly-ɛ-caprolactone (PCL) nanoparticles inhibit JAK2/STAT5 signaling in BT474 breast cancer cells by downregulating Bcl-2 and Mcl-1.

BACKGROUND: JAK/STAT signaling plays an important role in regulating cell proliferation. Reducing proliferation and inducing cell death with gene-specific inhibitors such as ruxolitinib, Receptor tyrosine kinases (RTK) inhibitor targeting JAK1/2, are therapeutic approaches. The use of nanoparticles can reduce the toxicity and side effects of drugs, as they act directly on cancer cells and can selectively increase drug accumulation in tumor cells. Poly-ɛ-caprolactone (PCL) is a polymer that is frequently used in drug development. In this study, Rux-PCL-NPs were synthesized to increase the effectiveness of ruxolitinib. In addition, this study aimed to determine the effect of Rux-PCL-NPs on JAK/STAT signaling and apoptotic cell death. METHODS AND RESULTS: Rux-PCL-NPs were synthesized by nanoprecipitation. The Rux-PCL-NPs had a spherical and mean particle size of 219 ± 88.66 nm and a zeta potential of 0.471 ± 0.453 mV. In vitro cytotoxicity and antiproliferative effects were determined by MTT and soft agar colony formation assays, respectively. The effects of ruxolitinib, PCL-NPs, and Rux-PCL-NPs on apoptosis and the JAK/STAT pathway in cells were examined by western blot analysis. PCL-NPs did not have a toxic effect on the cells. The IC50 value of Rux-PCL-NPs was decreased 50-fold compared to that of ruxolitinib. Rux-PCL-NPs promoted cell death by downregulating JAK2 and STAT5, thereby inhibiting the JAK/STAT pathway. CONCLUSIONS: Our results revealed that Rux-PCL-NPs, which increased the efficacy of ruxolitinib, regulated apoptosis and the JAK2/STAT5 pathway.

Transcriptome profiling and proteomic validation reveals targets of the androgen receptor signaling in the BT-474 breast cancer cell line.

BACKGROUND: Accumulating evidence suggests that the androgen receptor (AR) and its endogenous ligands influence disease progression in breast cancer (BCa). However, AR-mediated changes in BCa differ among the various BCa subtypes according to their hormone receptor profile [i.e., presence/absence of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2, (HER2)]. Thus, we explored the androgen-regulated transcriptomic changes in the ER+PR+HER2+ BCa cell line, BT-474, and compared them with PR-mediated changes. METHODS: We performed RNA sequencing analysis in treated BT-474 cells with dihydrotestosterone (DHT) and progesterone. Validation of the top ten differentially androgen-regulated genes and a number of other genes found in enriched signaling pathways was performed by qRT-PCR in BT-474 and other BCa cell lines. In addition, a parallel reaction monitoring targeted proteomic approach was developed to verify selected transcripts at the protein level. RESULTS: In total 19,450 transcripts were detected, of which 224 were differentially regulated after DHT treatment. The increased expression of two well-known androgen-regulated genes, KLK2 (p < 0.05) and KLK3 (p < 0.001), confirmed the successful androgen stimulation in BT-474 cells. The transcription factor, ZBTB16, was the most highly upregulated gene, with ~ 1000-fold change (p < 0.001). Pathway enrichment analysis revealed downregulation of the DNA replication processes (p < 0.05) and upregulation of the androgen signaling and fatty acid metabolism pathways (p < 0.05). Changes related to progesterone treatment showed opposite effects in gene expression than DHT treatment. Similar expression profiles were observed among other BCa cell lines expressing high levels of AR (ZR75.1 and MBA-MB-453). The parallel reaction monitoring targeted proteomic analysis further confirmed that altered protein expression (KLK3, ALOX15B) in the supernatant and cell lysate of DHT-treated BT-474 cells, compared to control cells. DISCUSSION: Our findings suggest that AR modulates the metabolism of BT-474 cells by affecting the expression of a large number of genes and proteins. Based on further pathway analysis, we suggest that androgen receptor acts as a tumor suppressor in the BT-474 cells.

Feasibility of Non-invasive Measurement of Tumour NAD(H) by In Vivo Phosphorus-31 Magnetic Resonance Spectroscopy.

Importance of the redox status of nicotinamide adenine dinucleotide (NAD), including its oxidized (NAD+) and reduced (NADH) forms, has been shown in many biological processes. However, NAD(H) redox status assessment is traditionally limited to biochemical assays in vitro or optical redox imaging (ORI) for superficial tissues in vivo and for deep tissues ex vivo. In recent years, phosphorous-31 magnetic resonance spectroscopy (31P-MRS) was utilized to quantify NAD+, NADH, and the redox ratio NAD+/NADH in normal tissues in vivo. The quantification is based on the spectral fitting of the upfield shoulder of the αATP peak that contains signals of NAD+ (a quartet) and NADH (a singlet), assuming pH-independence of peak positions. To evaluate the feasibility of measuring tumour NAD(H) redox status in vivo, we fitted single voxel 31P-MR spectra of subcutaneous mouse xenografts of human breast cancer cell lines acquired on a 9.4-T horizontal bore preclinical MR scanner. We found larger variations in the chemical shift offsets of NAD+ and NADH from αATP in these tumours than the literature values of normal tissues. Furthermore, our 31P-MR spectra of αATP, NAD+, and NADH solution phantoms indicated that the chemical shift of αATP and thus the offsets between NAD(H) and αATP were pH dependent. Therefore, whether tumour pH should be incorporated into the spectral fitting model should be further evaluated. Additionally, spectral resolution and signal-to-noise ratio should be improved by optimising 31P-MRS protocols, increasing data acquisition time, and using a more sensitive coil for signal detection.

ONC201-Induced Mitochondrial Dysfunction, Senescence-like Phenotype, and Sensitization of Cultured BT474 Human Breast Cancer Cells to TRAIL.

ONC201, the anticancer drug, targets and activates mitochondrial ATP-dependent caseinolytic peptidase P (ClpP), a serine protease located in the mitochondrial matrix. Given the promise of ONC201 in cancer treatment, we evaluated its effects on the breast ductal carcinoma cell line (BT474). We showed that the transient single-dose treatment of BT474 cells by 10 µM ONC201 for a period of less than 48 h induced a reversible growth arrest and a transient activation of an integrated stress response indicated by an increased expression of CHOP, ATF4, and GDF-15, and a reduced number of mtDNA nucleoids. A prolonged exposure to the drug (>48 h), however, initiated an irreversible loss of mtDNA, persistent activation of integrated stress response proteins, as well as cell cycle arrest, inhibition of proliferation, and suppression of the intrinsic apoptosis pathway. Since Natural Killer (NK) cells are quickly gaining momentum in cellular anti-cancer therapies, we evaluated the effect of ONC201 on the activity of the peripheral blood derived NK cells. We showed that following the ONC 201 exposure BT474 cells demonstrated enhanced sensitivity toward human NK cells that mediated killing. Together our data revealed that the effects of a single dose of ONC201 are dependent on the duration of exposure, specifically, while short-term exposure led to reversible changes; long-term exposure resulted in irreversible transformation of cells associated with the senescent phenotype. Our data further demonstrated that when used in combination with NK cells, ONC201 created a synergistic anti-cancer effect, thus suggesting its possible benefit in NK-cell based cellular immunotherapies for cancer treatment.

A basal level of γ-linolenic acid depletes Ca2+ stores and induces endoplasmic reticulum and oxidative stresses to cause death of breast cancer BT-474 cells.

Gamma-linolenic acid (GLA), a natural fatty acid obtained from oils of various vegetables and seeds, has been demonstrated as an anticancer agent. In this work, we investigated the anticancer effects of GLA on breast cancer BT-474 cells. GLA at 30 µM, a concentration reportedly within the range of circulating concentrations in clinical studies, caused apoptotic cell death. GLA caused an elevation in mitochondrial Ca2+ level and a decrease in mitochondrial membrane potential. GLA treatment depleted cyclopiazonic acid (CPA)-sensitive Ca2+ store and triggered substantial Ca2+ influx. Intracellular Ca2+ release triggered by GLA was suppressed by 3 µM xestospongin C (XeC, IP3 receptor-channel blocker) and 100 µM ryanodine (ryanodine receptor-channel blocker), suggesting that the Ca2+ release was via IP3 receptor-channel and ryanodine receptor-channel. Increased expressions of p-eIF2α and CHOP were observed in GLA-treated cells, suggesting GLA-treated cells had increased expressions of p-eIF2α and CHOP, which suggest endoplasmic reticulum (ER) stress. In addition, GLA elicited increased production of reactive oxygen species. Taken together, our results suggest a basal level of GLA induced apoptotic cell death by causing Ca2+ overload, mitochondrial dysfunction, Ca2+ store depletion, ER stress, and oxidative stress. This is the first report to show that GLA caused Ca2+ store depletion and ER stress. GLA-induced Ca2+ store depletion resulted from opening of IP3 receptor-channel and ryanodine receptor-channel.

Design and Characterization of Liposomal Methotrexate and Its Effect on BT-474 Breast Cancer Cell Line.

Background: Breast cancer is the most common type of cancer among women worldwide. Traditional treatments, including chemotherapy, surgery, mastectomy, and radiotherapy, are commonly used. Because of the limitation of the aforementioned methods, novel treatment strategies are needed. Methotrexate is a chemotherapeutic drug, which is commonly used to treat breast cancer. Because of the side effects of the free drug, the liposomal form of the drug is suggested. Methods: Liposomal methotrexate was prepared and the encapsulation efficiency was measured. Moreover, the particle size and the zeta potential were measured. The liposome morphology was confirmed using transmission electron microscopy. The MTT assay was done to examine the cytotoxicity of free and encapsulated methotrexate on BT-474 cell line. The Annexin-V/PI dual staining assay was performed to assess the apoptosis in BT-474 breast cancer cells via the flow cytometry method. Results: The transmission electron microscopy results confirmed the integrated and spherical structure of the nanoparticles. The results of drug release showed that in acidic pH (5.4), more than 90% of the drug was released after 24 hours, which was higher than 2 other pHs. Furthermore, the IC50 value of liposomal methotrexate was determined as 2.15 and 0.82 mg/mL for 24 and 48 hours. The flow cytometry results confirmed that liposomal methotrexate had a greater cytotoxic effect on cancer cells compared with free methotrexate. Conclusion: Because of the advantages of liposomal based nanocarriers, in this study, liposomal methotrexate could be suggested as an appropriate candidate to treat breast cancer.

Anti-HER2 induced myeloid cell alterations correspond with increasing vascular maturation in a murine model of HER2+ breast cancer.

BACKGROUND: Therapy targeted to the human epidermal growth factor receptor type 2 (HER2) is used in combination with cytotoxic therapy in treatment of HER2+ breast cancer. Trastuzumab, a monoclonal antibody that targets HER2, has been shown pre-clinically to induce vascular changes that can increase delivery of chemotherapy. To quantify the role of immune modulation in treatment-induced vascular changes, this study identifies temporal changes in myeloid cell infiltration with corresponding vascular alterations in a preclinical model of HER2+ breast cancer following trastuzumab treatment. METHODS: HER2+ tumor-bearing mice (N = 46) were treated with trastuzumab or saline. After extraction, half of each tumor was analyzed by immunophenotyping using flow cytometry. The other half was quantified by immunohistochemistry to characterize macrophage infiltration (F4/80), vascularity (CD31 and α-SMA), proliferation (Ki67) and cellularity (H&E). Additional mice (N = 10) were used to quantify differences in tumor cytokines between control and treated groups. RESULTS: Immunophenotyping showed an increase in macrophage infiltration 24 h after trastuzumab treatment (P ≤ 0.05). With continued trastuzumab treatment, the M1 macrophage population increased (P = 0.02). Increases in vessel maturation index (i.e., the ratio of α-SMA to CD31) positively correlated with increases in tumor infiltrating M1 macrophages (R = 0.33, P = 0.04). Decreases in VEGF-A and increases in inflammatory cytokines (TNF-α, IL-1ß, CCL21, CCL7, and CXCL10) were observed with continued trastuzumab treatment (P ≤ 0.05). CONCLUSIONS: Preliminary results from this study in a murine model of HER2+ breast cancer show correlations between immune modulation and vascular changes, and reveals the potential for anti-HER2 therapy to reprogram immunosuppressive components of the tumor microenvironment. The quantification of immune modulation in HER2+ breast cancer, as well as the mechanistic insight of vascular alterations after anti-HER2 treatment, represent novel contributions and warrant further assessment for potential clinical translation.

Chrysophanol selectively represses breast cancer cell growth by inducing reactive oxygen species production and endoplasmic reticulum stress via AKT and mitogen-activated protein kinase signal pathways.

Breast cancer is a leading lethal gynecological cancer. Although many tumor markers and target genes have been studied in breast cancer, its incidence is increasing. Recently, the therapeutic effects of natural phytochemicals have been studied in various cancers as adjuvants. Chrysophanol is an anti-inflammatory, anti-angiogenetic, and anti-tumor anthraquinone but has not been widely studied in cancers. Here, we verified the anti-cancer effects and cellular mechanism of chrysophanol in human breast cancer cells (BT-474 and MCF-7). Chrysophanol selectively inhibited cell proliferation and induced apoptosis of breast cancer cells but not of normal mammary ductal epithelial cells, MCF-12A. Additionally, chrysophanol increased loss of mitochondrial membrane potential and cytosolic calcium levels to activate pro-apoptotic proteins, Bax, Bak, and cytochrome c, in both cell lines. Reactive oxygen species (ROS) overproduction by chrysophanol resulted in endoplasmic reticulum (ER) stress, leading to an increase in PERK, eIF2α, GADD153, and IRE1α levels in BT-474 and MCF-7 cells. These ER stress proteins increased by chrysophanol were repressed by co-treatment with N-acetyl-L-cysteine, an ROS inhibitor. Western blotting showed that chrysophanol down-regulated ERK1/2, AKT, P70S6K, and S6 in both cell lines. However, P38 and JNK activities decreased in BT-474 cells and increased in MCF-7 cells. Additionally, co-treatment with ERK1/2 (U0126) or an AKT inhibitor (LY294002) plus chrysophanol reduced cell proliferation, whereas P38 (SB203580) and a JNK inhibitor (SP600125) showed synergic effects only in BT-474 cell lines. These results show that chrysophanol has anti-cancer effects on human breast cancer cells, specifically through mitochondrial apoptosis and ER stress induction.

Docetaxel-loaded nanostructured lipid carriers functionalized with trastuzumab (Herceptin) for HER2-positive breast cancer cells.

The aim of the present study was to prepare Herceptin targeted nanostructured lipid carriers (NLCs) of docetaxel (DTX). Herceptin was conjugated by chemical and physical methods to NLCs prepared by solvent extraction technique followed by probe sonication. Different types of fatty amines were used in construction of NLCs. The NLCs were characterized for their antibody coupling efficiency, particle size, zeta potential, polydispersity index, drug entrapment efficiency and drug release profiles. The toxicity of NLCs on MDA-MB-468 (HER2 negative receptor) and BT-474 (HER2 positive) breast cancer cell lines was evaluated by MTT assay. Also their cellular uptake was studied by flow-cytometry and fluorescent microscopy. The results showed the NLCs containing stearyl amine had the lowest particle size, the highest zeta potential and antibody coupling efficiency values. Herceptin binding to NLCs led to reduction in zeta potential and drug entrapment efficiency while, particle size increased. The NLCs containing spermine(SP) released DTX slower than other fatty amines. Non-conjugated nanoparticles containing DTX had more toxicity than the free DTX on both cell lines. Herceptin targeted NLCs caused more mortality on BT-474 cells than MDA-MB-468 cells. Flow-cytometry studies revealed enhanced cellular uptake of nanoparticles chemically conjugated by Herceptin on the BT-474 cells. DTX loaded in chemically conjugated NLCs to Herceptin showed more cytotoxic effects than the physically coated nanoparticles. The Herceptin conjugated NLCs seem promising in oriented delivery of DTX to HER2 positive breast cancer cells.

Hansen solubility parameters (HSP) for prescreening formulation of solid lipid nanoparticles (SLN): in vitro testing of curcumin-loaded SLN in MCF-7 and BT-474 cell lines.

Curcumin, a phenolic compound from turmeric rhizome (Curcuma longa), has many interesting pharmacological effects, but shows very low aqueous solubility. Consequently, several drug delivery systems based on polymeric and lipid raw materials have been proposed to increase its bioavailability. Solid lipid nanoparticles (SLN), consisting of solid lipid matrix and a surfactant layer can load poorly water-soluble drugs, such as curcumin, deliver them at defined rates and enhance their intracellular uptake. In the present work, we demonstrate that, despite the drug's affinity to lipids frequently used in SLN production, the curcumin amount loaded in most SLN formulations may be too low to exhibit anticancer properties. The predictive curcumin solubility in solid lipids has been thoroughly analyzed by Hansen solubility parameters, in parallel with the lipid-screening solubility tests for a range of selected lipids. We identified the most suitable lipid materials for curcumin-loaded SLN, producing physicochemically stable particles with high encapsulation efficiency (>90%). Loading capacity of curcumin in SLN allowed preventing the cellular damage caused by cationic SLN on MCF-7 and BT-474 cells but was not sufficient to exhibit drug's anticancer properties. But curcumin-loaded SLN exhibited antioxidant properties, substantiating the conclusions that curcumin's effect in cancer cells is highly dose dependent.

Large-Scale Analysis of Breast Cancer-Related Conformational Changes in Proteins Using SILAC-SPROX.

Proteomic methods for disease state characterization and biomarker discovery have traditionally utilized quantitative mass spectrometry methods to identify proteins with altered expression levels in disease states. Here we report on the large-scale use of protein folding stability measurements to characterize different subtypes of breast cancer using the stable isotope labeling with amino acids in cell culture and stability of proteins from rates of oxidation (SILAC-SPROX) technique. Protein folding stability differences were studied in a comparison of two luminal breast cancer subtypes, luminal-A and -B (i.e., MCF-7 and BT-474 cells, respectively), and in a comparison of a luminal-A and basal subtype of the disease (i.e., MCF-7 and MDA-MB-468 cells, respectively). The 242 and 445 protein hits identified with altered stabilities in these comparative analyses included a large fraction with no significant expression level changes. This suggests thermodynamic stability measurements create a new avenue for protein biomarker discovery. A number of the identified protein hits are known from other biochemical studies to play a role in tumorigenesis and cancer progression. This not only substantiates the biological significance of the protein hits identified using the SILAC-SPROX approach, but it also helps elucidate the molecular basis for their disregulation and/or disfunction in cancer.

Trastuzumab improves tumor perfusion and vascular delivery of cytotoxic therapy in a murine model of HER2+ breast cancer: preliminary results.

To employ in vivo imaging and histological techniques to identify and quantify vascular changes early in the course of treatment with trastuzumab in a murine model of HER2+ breast cancer. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was used to quantitatively characterize vessel perfusion/permeability (via the parameter K (trans) ) and the extravascular extracellular volume fraction (v e ) in the BT474 mouse model of HER2+ breast cancer (N = 20) at baseline, day one, and day four following trastuzumab treatment (10 mg/kg). Additional cohorts of mice were used to quantify proliferation (Ki67), microvessel density (CD31), pericyte coverage (α-SMA) by immunohistochemistry (N = 44), and to quantify human VEGF-A expression (N = 29) throughout the course of therapy. Longitudinal assessment of combination doxorubicin ± trastuzumab (N = 42) tested the hypothesis that prior treatment with trastuzumab will increase the efficacy of subsequent doxorubicin therapy. Compared to control tumors, trastuzumab-treated tumors exhibited a significant increase in K (trans) (P = 0.035) on day four, indicating increased perfusion and/or vessel permeability and a simultaneous significant increase in v e (P = 0.01), indicating increased cell death. Immunohistochemical and ELISA analyses revealed that by day four the trastuzumab-treated tumors had a significant increase in vessel maturation index (i.e., the ratio of α-SMA to CD31 staining) compared to controls (P < 0.001) and a significant decrease in VEGF-A (P = 0.03). Additionally, trastuzumab dosing prior to doxorubicin improved the overall effectiveness of the therapies (P < 0.001). This study identifies and validates improved perfusion characteristics following trastuzumab therapy, resulting in an improvement in trastuzumab-doxorubicin combination therapy in a murine model of HER2+ breast cancer. This data suggests properties of vessel maturation. In particular, the use of DCE-MRI, a clinically available imaging method, following treatment with trastuzumab may provide an opportunity to optimize the scheduling and improve delivery of subsequent cytotoxic therapy.

Targeting EGFR/HER2 tyrosine kinases with a new potent series of 6-substituted 4-anilinoquinazoline hybrids: Design, synthesis, kinase assay, cell-based assay, and molecular docking.

Coexpression of EGFR and HER2 has been found in many tumors such as breast, ovarian, colon and prostate cancers, with poor prognosis of the patients. Herein, our team has designed and synthesized new eighteen compounds with 6-substituted 4-anilinoquinazoline core to selectively inhibit EGFR/HER2 tyrosine kinases. Twelve compounds (8a-8d, 9a, 9c, 9d, 10a, 10c, 11b, 14, and 15) showed nanomolar range of IC50 values on EGFR and/or HER2 kinases. Accordingly, a detailed structure activity relationship (SAR) was established. A molecular docking study demonstrated the favorable binding modes of 8d, 9b, 9d and 10d at the ATP active site of both kinases. A kinase selectivity profile performed for compound 8d showed great selectivity for EGFR and HER2. In addition, 8d, 9c, and 9d exerted selective promising cytotoxic activity over BT-474 cell line with IC50 values of 2.70, 1.82 and 1.95 µM, respectively. From these results, we report analogs 8d, 9c, and 9d as promising candidates for the discovery of well-balanced compounds in terms of the kinase inhibitory potency and antiproliferative activity.

Lead Optimization of 2-Cyclohexyl-N-[(Z)-(3-methoxyphenyl/3-hydroxyphenyl) methylidene]hydrazinecarbothioamides for Targeting the HER-2 Overexpressed Breast Cancer Cell Line SKBr-3.

Lead derivatives of 2-cyclohexyl-N-[(Z)-(3-methoxyphenyl/3-hydroxyphenyl) methylidene]hydrazinecarbothioamides 1-18 were synthesized, characterized and evaluated in vitro against HER-2 overexpressed breast cancer cell line SKBr-3. All the compounds showed activity against HER-2 overexpressed SKBr-3 cells with IC50 = 17.44 ± 0.01 µM to 53.29 ± 0.33 µM. (2Z)-2-(3-Hydroxybenzylidene)-N-(3-methoxyphenyl)hydrazinecarbothioamide (12, IC50 = 17.44 ± 0.01 µM) was found to be most potent compound of this series targeting HER-2 overexpressed breast cancer cells compared to the standard drug 5-fluorouracil (5-FU) (IC50 = 38.58 ± 0.04 µM). Compound 12 inhibited the cellular proliferation via DNA degradation.

Synergistic effects of ozone with doxorubicin on the proliferation, apoptosis and metastatic profile of luminal-B type human breast cancer cell line.

OBJECTIVE: Luminal-B type human breast cancer cell line (BT-474) to assess the synergistic effects of ozone applied after chemotherapeutic treatment with various dosages of doxorubicin, and compare the results with the effects on L929 fibroblast cell line. METHODS: Doxorubicin (1-50 M) was added to each cell lines and left to sit for 24 h at 37 °C. Then, as combination groups, half of the groups were incubated with 30 g/mL ozone for 25 min. Tumor necrosis factor alpha (TNF-α), transforming growth factor beta (TGF-ß), and matrix metalloproteinase-2 and - 9 (MMP-2 and MMP-9) levels were measured using the MTT test, flow cytometry, and immunocytochemistry, respectively. RESULTS: When compared to simply doxorubicin-applied cells without ozone treatment, each dose of doxorubicin + ozone treatment considerably boosted L929 viability but significantly decreased BT-474 viability. Additionally, the combination increased the apoptotic impact of doxorubicin on BT-474 but not L929 (P < 0.001). TGF-, MMP-2, and MMP-9 levels of L929 after combination were substantially higher than those of the other groups (P < 0.01). Doxorubicin's effect on BT-474's protein levels, which had significantly decreased in comparison to those of the other groups, was reversed by the combination treatment (P < 0.05). CONCLUSION: Doxorubicin's anti-proliferative and apoptotic effects were enhanced by ozone treatment in BT-474 cells, but it also repaired and healed healthy fibroblast cells that had been harmed by the cytotoxicity of the chemotherapy drug. If doxorubicin and ozone treatment are coupled, BT-474 cells may develop resistance to it through expressions of TNF-α, TGF-ß, MMP-2, and MMP-9.

Unveiling the mechanisms underlying photothermal efficiency of gold shell-isolated nanoparticles (AuSHINs) on ductal mammary carcinoma cells (BT-474).

Gold nanoparticles are valuable photothermal agents owing to their efficient photothermal conversion, photobleaching resistance, and potential surface functionalization. Herein, we combined bioinspired membranes with in vitro assays to elicit the molecular mechanisms of gold shell-isolated nanoparticles (AuSHINs) on ductal mammary carcinoma cells (BT-474). Langmuir and Langmuir-Schaefer (LS) films were handled to build biomembranes from BT-474 lipid extract. AuSHINs incorporation led to surface pressure-area (π-A) isotherms expansion, increasing membrane flexibility. Fourier-transform infrared spectroscopy (FTIR) of LS multilayers revealed electrostatic AuSHINs interaction with head portions of BT-474 lipid extract, causing lipid chain disorganization. Limited AuSHINs insertion into monolayer contributed to hydroperoxidation of the unsaturated lipids upon irradiation, consistently with the surface area increments of ca. 2.0%. In fact, membrane disruption of irradiated BT-474 cells containing AuSHINs was confirmed by confocal microscopy and LDH leakage, with greater damage at 2.2 × 1013 AuSHINs/mL. Furthermore, the decrease in nuclei dimensions indicates cell death through photoinduced damage.

Folic Acid-Modified Ibrutinib-Loaded Silk Fibroin Nanoparticles for Cancer Cell Therapy with Over-Expressed Folate Receptor.

The anticancer drug ibrutinib (IB), also known as PCI-32765, is a compound that irreversibly inhibits Bruton's tyrosine kinase (BTK) and was initially developed as a treatment option for B-cell lineage neoplasms. Its action is not limited to B-cells, as it is expressed in all hematopoietic lineages and plays a crucial role in the tumor microenvironment. However, clinical trials with the drug have resulted in conflicting outcomes against solid tumors. In this study, folic acid-conjugated silk nanoparticles were used for the targeted delivery of IB to the cancer cell lines HeLa, BT-474, and SKBR3 by exploiting the overexpression of folate receptors on their surfaces. The results were compared with those of control healthy cells (EA.hy926). Cellular uptake studies confirmed total internalization of the nanoparticles functionalized by this procedure in the cancer cells after 24 h, compared to nanoparticles not functionalized with folic acid, suggesting that cellular uptake was mediated by folate receptors overexpressed in the cancer cells. The results indicate that the developed nanocarrier can be used for drug targeting applications by enhancing IB uptake in cancer cells with folate receptor overexpression.

Mass spectroscopy-based proteomics and metabolomics analysis of triple-positive breast cancer cells treated with tamoxifen and/or trastuzumab.

PURPOSE: HER2-enriched breast cancer with high levels of hormone receptor expression, known as "triple positive" breast cancer, may represent a new entity with a relatively favourable prognosis against which the combination of chemotherapy, HER-2 inhibition, and endocrine treatment may be considered overtreatment. We explored the effect of the anticancer drugs tamoxifen and trastuzumab, both separately and in combination, on the integrated proteomic and metabolic profile of "triple positive" breast cancer cells (BT-474). METHOD: We employed ultra-high-performance liquid chromatography-quadrupole time of flight mass spectrometry using a Bruker timsTOF to investigate changes in BT-474 cell line treated with either tamoxifen, trastuzumab or a combination. Differentially abundant metabolites were identified using the Bruker Human Metabolome Database metabolite library and proteins using the Uniprot proteome for Homo sapiens using MetaboScape and MaxQuant, respectively, for identification and quantitation. RESULTS: A total of 77 proteins and 85 metabolites were found to significantly differ in abundance in BT-474 treated cells with tamoxifen 5 µM/and or trastuzumab 2.5 µM. Findings suggest that by targeting important cellular signalling pathways which regulate cell growth, apoptosis, proliferation, and chemoresistance, these medicines have a considerable anti-growth effect in BT-474 cells. Pathways enriched for dysregulation include RNA splicing, neutrophil degranulation and activation, cellular redox homeostasis, mitochondrial transmembrane transport, ferroptosis and necroptosis, ABC transporters and central carbon metabolism. CONCLUSION: Our findings in protein and metabolite level research revealed that anti-cancer drug therapy had a significant impact on the key signalling pathways and molecular processes in triple positive BT-474 cell lines.

Quantifying Tumor Heterogeneity via MRI Habitats to Characterize Microenvironmental Alterations in HER2+ Breast Cancer.

This study identifies physiological habitats using quantitative magnetic resonance imaging (MRI) to elucidate intertumoral differences and characterize microenvironmental response to targeted and cytotoxic therapy. BT-474 human epidermal growth factor receptor 2 (HER2+) breast tumors were imaged before and during treatment (trastuzumab, paclitaxel) with diffusion-weighted MRI and dynamic contrast-enhanced MRI to measure tumor cellularity and vascularity, respectively. Tumors were stained for anti-CD31, anti-ɑSMA, anti-CD45, anti-F4/80, anti-pimonidazole, and H&E. MRI data was clustered to identify and label each habitat in terms of vascularity and cellularity. Pre-treatment habitat composition was used stratify tumors into two "tumor imaging phenotypes" (Type 1, Type 2). Type 1 tumors showed significantly higher percent tumor volume of the high-vascularity high-cellularity (HV-HC) habitat compared to Type 2 tumors, and significantly lower volume of low-vascularity high-cellularity (LV-HC) and low-vascularity low-cellularity (LV-LC) habitats. Tumor phenotypes showed significant differences in treatment response, in both changes in tumor volume and physiological composition. Significant positive correlations were found between histological stains and tumor habitats. These findings suggest that the differential baseline imaging phenotypes can predict response to therapy. Specifically, the Type 1 phenotype indicates increased sensitivity to targeted or cytotoxic therapy compared to Type 2 tumors.

Quantifying the Effects of Combination Trastuzumab and Radiation Therapy in Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer.

Background: Trastuzumab induces cell cycle arrest in HER2-overexpressing cells and demonstrates potential in radiosensitizing cancer cells. The purpose of this study is to quantify combination trastuzumab and radiotherapy to determine their synergy. Methods: In vitro, HER2+ cancer cells were treated with trastuzumab, radiation, or their combination, and imaged to evaluate treatment kinetics. In vivo, HER2+ tumor-bearing mice were treated with trastuzumab and radiation, and assessed longitudinally. An additional cohort was treated and sacrificed to quantify CD45, CD31, α-SMA, and hypoxia. Results: The interaction index revealed the additive effects of trastuzumab and radiation in vitro in HER2+ cell lines. Furthermore, the results revealed significant differences in tumor response when treated with radiation (p < 0.001); however, no difference was seen in the combination groups when trastuzumab was added to radiotherapy (p = 0.56). Histology revealed increases in CD45 staining in tumors receiving trastuzumab (p < 0.05), indicating potential increases in immune infiltration. Conclusions: The in vitro results showed the additive effect of combination trastuzumab and radiotherapy. The in vivo results showed the potential to achieve similar efficacy of radiotherapy with a reduced dose when combined with trastuzumab. If trastuzumab and low-dose radiotherapy induce greater tumor kill than a higher dose of radiotherapy, combination therapy can achieve a similar reduction in tumor burden.