Red Sea Sponge Callyspongia siphonella Extract Induced Growth Inhibition and Apoptosis in Breast MCF-7 and Hepatic HepG-2 Cancer Cell Lines in 2D and 3D Cell Cultures.

Introduction: The increasing incidence of cancer diseases necessitates the urgent exploration of new bioactive compounds. One of the trends in drug discovery is marine sponges which is gaining significant support due to the abundant production of natural pharmaceutical compounds obtained from marine ecosystems. This study evaluates the anticancer properties of an organic extract from the Red Sea sponge Callyspongia siphonella (C. siphonella) on HepG-2 and MCF-7 cancer cell lines. Methods: C. siphonella was collected, freeze-dried, and extracted using a methanol-dichloromethane mixture. The extract was analyzed via Liquid Chromatography-Mass Spectrometry. Cytotoxic effects were assessed through cell viability assays, apoptosis detection, cell cycle analysis, mitochondrial membrane potential assays, scratch-wound healing assays, and 3D cell culture assays. Results: Fifteen compounds were identified in the C. siphonella extract. The extract showed moderate cytotoxicity against MCF-7 and HepG-2 cells, with IC50 values of 35.6 ± 6.9 µg/mL and 64.4 ± 8 µg/mL, respectively, after 48 hours of treatment. It induced cell cycle arrest at the G2/M phase in MCF-7 cells and the S phase in HepG-2 cells. Apoptosis increased significantly in both cell lines, accompanied by reduced mitochondrial membrane potential. The extract inhibited cell migration, with notable reductions after 24 and 48 hours. In 3D cell cultures, the extract had IC50 values of 5.1 ± 2 µg/mL for MCF-7 and 166.4 ± 27 µg/mL for HepG-2 after 7 days of treatment, showing greater potency in MCF-7 spheres compared to HepG-2 spheres. Discussion and Conclusion: The anticancer activity is attributed to the bioactive compounds. The C. siphonella extract's ability to induce apoptosis, disrupt mitochondrial membrane potential, and arrest the cell cycle highlights its potential as a novel anticancer agent. Additional research is required to investigate the underlying mechanism by which this extract functions as a highly effective anticancer agent.

Optimization of atorvastatin and quercetin-loaded solid lipid nanoparticles using Box-Behnken design.

Aim: The study explores the synergistic potential of atorvastatin (ATR) and quercetin (QUER)- loaded solid lipid nanoparticles (SLN) in combating breast cancer. Materials & methods: SLNs were synthesized using a high-shear homogenization method and optimized using Box-Behnken design. The SLNs were characterized and evaluated for their in vitro anticancer activity. Results: The optimized SLN exhibited narrow size distribution (PDI = 0.338 ± 0.034), a particle size of 72.5 ± 6.5 nm, higher entrapment efficiency (<90%), sustained release and spherical surface particles. The in vitro cytotoxicity studies showed a significant reduction in IC50 values on MDA-MB-231 cell lines. Conclusion: We report a novel strategy of repurposing well-known drugs and encapsulating them into SLNs as a promising drug-delivery system against breast cancer.

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Slow Sulfide Donor GYY4137 Increased the Sensitivity of Two Breast Cancer Cell Lines to Paclitaxel by Different Mechanisms.

Paclitaxel (PTX) is a chemotherapeutic agent affecting microtubule polymerization. The efficacy of PTX depends on the type of tumor, and its improvement would be beneficial in patients' treatment. Therefore, we tested the effect of slow sulfide donor GYY4137 on paclitaxel sensitivity in two different breast cancer cell lines, MDA-MB-231, derived from a triple negative cell line, and JIMT1, which overexpresses HER2 and is resistant to trastuzumab. In JIMT1 and MDA-MB-231 cells, we compared IC50 and some metabolic (apoptosis induction, lactate/pyruvate conversion, production of reactive oxygen species, etc.), morphologic (changes in cytoskeleton), and functional (migration, angiogenesis) parameters for PTX and PTX/GYY4137, aiming to determine the mechanism of the sensitization of PTX. We observed improved sensitivity to paclitaxel in the presence of GYY4137 in both cell lines, but also some differences in apoptosis induction and pyruvate/lactate conversion between these cells. In MDA-MB-231 cells, GYY4137 increased apoptosis without affecting the IP3R1 protein, changing the morphology of the cytoskeleton. A mechanism of PTX sensitization by GYY4137 in JIMT1 cells is distinct from MDA-MB-231, and remains to be further elucidated. We suggest different mechanisms of action for H2S on the paclitaxel treatment of MDA-MB-231 and JIMT1 breast cancer cell lines.

FEN1 Inhibition as a Potential Novel Targeted Therapy against Breast Cancer and the Prognostic Relevance of FEN1.

To improve breast cancer treatment and to enable new strategies for therapeutic resistance, therapeutic targets are constantly being studied. Potential targets are proteins of DNA repair and replication and genomic integrity, such as Flap Endonuclease 1 (FEN1). This study investigated the effects of FEN1 inhibitor FEN1-IN-4 in combination with ionizing radiation on cell death, clonogenic survival, the cell cycle, senescence, doubling time, DNA double-strand breaks and micronuclei in breast cancer cells, breast cells and healthy skin fibroblasts. Furthermore, the variation in the baseline FEN1 level and its influence on treatment prognosis was investigated. The cell lines show specific response patterns in the aspects studied and have heterogeneous baseline FEN1 levels. FEN1-IN-4 has cytotoxic, cytostatic and radiosensitizing effects, expressed through increasing cell death by apoptosis and necrosis, G2M share, senescence, double-strand breaks and a reduced survival fraction. Nevertheless, some cells are less affected by the cytotoxicity and fibroblasts show a rather limited response. In vivo, high FEN1 mRNA expression worsens the prognosis of breast cancer patients. Due to the increased expression in breast cancer tissue, FEN1 could represent a new tumor and prognosis marker and FEN1-IN-4 may serve as a new potent agent in personalized medicine and targeted breast cancer therapy.

Targeting cholesterol impairs cell invasion of all breast cancer types.

BACKGROUND: Breast cancer clinical outcome relies on its intrinsic molecular subtype and mortality is almost exclusively due to metastasis, whose mechanism remains unclear. We recently revealed the specific contribution of plasma membrane cholesterol to the invasion of malignant MCF10CAIa but not premalignant MCF10AT and normal MCF10A cell lines in 2D, through invadopodia formation and extracellular matrix (ECM) degradation. In the present study, we address the impact of breast cancer subtypes, mutations and aggressiveness on cholesterol implication in breast cancer cell invasion and 3D spheroid invasion and growth. METHODS: We used nine breast cancer cell lines grouped in four subtypes matching breast tumor classification. Four of these cell lines were also used to generate 3D spheroids. These cell lines were compared for cell invasion in 2D and 3D, spheroid growth in 3D, gelatin degradation, cortactin expression, activation and subcellular distribution as well as cell surface cholesterol distribution and lipid droplets. The effect of plasma membrane cholesterol depletion on all these parameters was determined in parallel and systematically compared with the impact of global matrix metalloproteinase (MMP) inhibition. RESULTS: The six invasive cell lines in 2D were sensitive to partial cholesterol depletion, independently of their subtype, aggressiveness or mutation. Nevertheless, the effect was stronger in the three cell lines able to degrade gelatin. 3D spheroid invasion was also reduced after cholesterol depletion in all breast cancer subtypes tested. Notably, targeting cholesterol was more powerful than MMP inhibition in reducing invasion in both 2D and 3D culture models. Moreover, cholesterol depletion in the six invasive cell lines impaired cortactin distribution in the perinuclear region where invadopodia localized. Breast cancer cell line aggressiveness relied on cholesterol-enriched domains at the ECM-free side and intracellular lipid droplets. Furthermore, the three gelatin-degrading cell lines were characterized by increased cholesterol-enriched submicrometric domains at their ECM-contact side. CONCLUSION: Together, our data suggest cell surface cholesterol combined with lipid droplet labeling as a breast cancer cell aggressiveness marker. They also open the way to test other cholesterol-targeting drugs in more complex models to further evaluate whether cholesterol could represent a strategy in breast cancer therapy.

Downregulation of MALAT1 in triple-negative breast cancer cells.

Background: MALAT1 is one of the most abundant nuclear long non-coding RNAs, which has been found to be elevated in various types of cancers. However, conflicting reports on MALAT1 in breast cancer cell lines challenge understanding of MALAT1's involvement in breast cancer progression. Aim: Measurement of normalized relative quantity (NRQ) of MALAT1 transcripts in cell lines representing triple-negative breast cancer (TNBC) and luminal breast cancer. Materials and methods: The studies were performed using cell lines representing luminal breast cancer (T47D, MCF-7), TNBC (MDA-MB-468, CAL-51, MDA-MB-231), and MCF-10A cell line of normal breast epithelial cells. Total RNA was isolated from six independent cell cultures of each line, treated with DNase I, and used to synthesize complementary DNA, which was used in quantitative real-time PCR (qPCR) assays. Four MALAT1 fragments and reference genes CCSER2, ANKRD17, PUM1, GAPDH were amplified. Results: Geometric means of the NRQ of MALAT1 in breast cancer cell lines had the shortest 95% confidence intervals when CCSER2 was used for normalization. MALAT1 major transcript levels thus estimated in TNBC cell lines were found to be statistically significantly reduced compared to levels in both MCF-10A cells and luminal breast cancer cell lines, while MALAT1 minority splice variants were found to be increased in almost all breast cancer cell lines. Conclusion: CCSER2-normalized qPCR results indicate MALAT1 downregulation in cell lines representing the more aggressive breast cancer subtype compared to both the normal breast epithelial cell line and the estrogen receptor-positive breast cancer cell lines.

Evaluation of Cytotoxicity of the Methanolic Extract of Red Sea Marine Sponge Xestospongia Testudinaria and Its Related Compounds Against MCF-7 Human Breast Cancer Cells.

Background: Breast cancer is a leading cause of death and one of the most common fatal medical conditions in the world. Chemical compounds of various types have been identified in the Red Sea marine sponge Xestospongia testudinaria, including sterol esters, sterols, indole alkaloids, and brominated polyunsaturated fatty acids. These compounds have demonstrated promising biological features, which in cludes anti-inflammatory, cancer preventive, and antioxidant capacities. Methods: The cytotoxic potential of Xestospongia testudinaria was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and morphological alterations in MCF-7 cell line. Furthermore, the flow cytometry was also utilized to assess apoptosis and identify changes in the cell cycle; besides, cell migration was assessed by scratch wound-healing assay. Results: A significant dose-dependent decrease in the percentage of MCF-7 cell viability was observed with IC50 39.8 ug/mL. Functional studies were performed on MCF-7 to show that Xestospongia testudinaria raises apoptotic cell death and induces growth arrest at the G1/G0 while inhibiting cell migration in scratch assay. Conclusion: These results demonstrated that Xestospongia testudinaria extract has an inhibitory effect on breast cancer cells proliferation, migration and induce apoptosis. Thus, it holds great promise as a potential treatment for breast cancer.

An insight into the cytotoxic, antimicrobial, antioxidant, and biocontrol perspective of novel Iron(III) complexes of substituted benzimidazoles: Inhibition kinetics and molecular simulations.

Mononuclear complexes [FeCl3L2(OH2)] (L = L1, L2) were designed and synthesized by combining FeCl3 with 2-(3'-Aminophenylbenzimidazole) (L1) and 2-[(3'-N-Salicylidinephenyl)benzimidazole] (L2) and were characterized by physico-analytical strategies. The redox properties of the complexes were disclosed by the cyclic voltammetric method. Further, the interactions of complexes with proteins were studied by performing molecular docking engaging protein models of common cancer therapeutic targets to foresee their affinity to bind to these proteins. The complexes evidenced better protein-ligand docking (-8.4 and -9.0 kcal mol-1) and higher binding energies than their ligands. However, the L1 complex displayed improved binding free energy (-33.576 ± 1.01 kcal mol-1) compared to the other complexes and individual ligands. These compounds were screened for in vitro cytotoxic assays against triple-negative breast cancer cell lines (MDA-MB-468 cells), anti-inflammatory, antimicrobial, and antioxidant properties. The in vitro study complemented the in silico assay; therefore, these compounds may be a viable choice for expanding anticancer therapy. Additionally, the L2 showed better biocontrol activity owing to the enhanced growth of Trichoderma and inhibited the growth of Fusarium oxysporum.Communicated by Ramaswamy H. Sarma.

Modulation of wheatgrass (Triticum aestivum Linn) toxicity against breast cancer cell lines by simulated microgravity.

This study scrutinizes the effects of simulated microgravity on the antioxidant and cytotoxic potential, along with the phytochemical content of wheatgrass (Triticum aestivum Linn). To imitate microgravity, wheatgrass seeds were germinated in a 3D-clinostat at different rotations per minute (5, 10, 15, and 20 rpm), together with terrestrial gravity control, over 10 days. After germination, the methanolic extracts were analyzed using UPLC-Triple Quad LCMS for their phytochemical composition and tested for their hydrogen peroxide, nitric oxide, and DPPH scavenging activities. The cytotoxic effects of these extracts were evaluated against normal skin fibroblasts, normal breast cells (MCF-10), and breast cancer cells (MCF-7 and MDA-231). The findings showed an extended root growth in wheatgrass germinated under microgravity (WGM) compared to under gravity (WGG). Additionally, WGM extracts demonstrated increased H2O2-, NO-, and DPPH-scavenging activities and a higher content of polyphenols and flavonoids than WGG extracts. These effects were amplified with an increase in clinostat rotations. Moreover, WGM extracts were found to contain a unique set of bioactive compounds (compounds that were detected in the microgravity-germinated wheatgrass but were either absent or present in lower concentrations in wheatgrass germinated under standard gravity conditions.), including pyridoxine, apigenin, and tocopherol, among others, which were absent in WGG. The UPLC-Triple Quad LCMS analysis revealed these unique bioactive compounds in WGM. Notably, WGM extracts showed enhanced cytotoxic effects against normal skin fibroblasts, normal MCF-10, MCF-7, and breast cancer MDA-231 cell lines, with increased cytotoxicity correlating with the number of clinostat rotations. Particularly, WGM extract (at 20 rpm) demonstrated significantly stronger cytotoxicity against MCF-7 breast cancer cells. Further in-depth gene expression analysis of MCF-7 cells exposed to WGM revealed a significant downregulation of genes integral to breast cancer pathways, tyrosine kinase signaling, and DNA repair, complemented by upregulation of certain cell survival and cytotoxic genes. These alterations in genetic pathways associated with cell survival, hormone responses, and cancer progression may elucidate the enhanced cytotoxicity observed in WGM extracts. Our findings underscore the potential of microgravity as a tool to enhance the cytotoxic capabilities of wheatgrass against cancer cell lines, presenting a promising direction for future research in the field of space biology and its implications for terrestrial health.

2-Alkyl-Substituted-4-Amino-Thieno[2,3-d]Pyrimidines: Anti-Proliferative Properties to In Vitro Breast Cancer Models.

Thienopyrimidines are structural analogs of quinazolines, and the creation of new 2-alkyl derivatives of ethyl 4-aminothienopyrimidine-6-carboxylates for the study of their anti-proliferative properties is of great pharmacological interest. Some 2-alkyl-4-amino-thieno[2,3-d]pyrimidines 2-5 were synthesized, and their cyto- and phototoxicity against BALB 3T3 cells were established by an in vitro 3T3 NRU test. The obtained results indicate that the tested compounds are not cytotoxic or phototoxic, and that they are appropriate to be studied for their anti-proliferative and anti-tumor properties. The anti-proliferative potential of the compounds was investigated on MCF-7 and MDA-MB-231 cancer cells, as well as a MCF-10A cell line (normal human mammary epithelial cells). The most toxic to MCF-7 was thienopyrimidine 3 with IC50 13.42 µg/mL (IC50 0.045 µM), followed by compound 4 (IC50 28.89 µg/mL or IC50 0.11 µM). The thienopyrimidine 4 revealed higher selectivity to MCF-7 and lower activity (IC50 367 µg/mL i.e., 1.4 µM) than compound 3 with MCF-10A cells. With respect to MDA-MB-231 cells, ester 2 manifested the highest effect with IC50 52.56 µg/mL (IC50 0.16 µM), and 2-ethyl derivative 4 revealed IC50 62.86 µg/mL (IC50 0.24 µM). It was estimated that the effect of the substances on the cell cycle progression was due to cell cycle arrest in the G2 stage for MDA-MB-231, while arrest in G1 was detected for the estrogen (ER)-positive MCF-7 cell line. The tested compound's effects on the change of the zeta potential in the tumorigenic cells utilized in this study were determined. The calculation which we performed of the physicochemical properties and pharmacokinetic parameters influencing the biological activity suggested high intestinal absorption, as well as drug-likeness.

ST6GALNAC1 promotes the invasion and migration of breast cancer cells via the EMT pathway.

BACKGROUND: A specific sialyl-transferases called ST6GALNAC1 has been proven to up-regulate abnormal O-glycosylation, which is strongly associated with tumorigenesis and cancer progression. However, the precise pathological outcome of ST6GALNAC1 expression in breast cancer cells remains unknown. Therefore, our study aims to investigate the functional role of ST6GALNAC1 and its impact on the epithelial-mesenchymal transition (EMT) pathway in breast cancer cells. METHODS: Plasmids with siRNA were used to construct ST6GALNAC1 knockoff (si-ST6GALNAC1) MDA-MB-231 and MDA-MB-453 cells, while lentiviruses were used to construct ST6GALNAC1 over-expression (oe-ST6GALNAC1) MCF-7 and BT474 cells. Transfer efficiency was verified by Western Blot. Then we selected transfected cells and assessed the changes in cell proliferation, invasion, migration, and EMT markers. RESULTS: The expression of ST6GALNAC1 significantly enhanced cell migration and invasion, which was confirmed by Wound Scratch Assay and Transwell Assay. Particularly, ST6GALNAC1 expression directly induced the EMT signaling pathway. E-cadherin was markedly decreased in oe-ST6GALNAC1 cells, accompanied by an up-regulation of mesenchymal markers including N-cadherin, snail, and ZEB1. However, no significant correlation was found between ST6GALNAC1 expression and cell proliferation. All of the outcomes were reversely validated in si-ST6GALNAC1 cells. CONCLUSIONS: The expression of ST6GALNAC1 promotes cell migration and invasion probably by triggering the molecular process of the EMT pathway in breast cancer cells, which may provide new clues for designing novel molecular targeted drugs in breast cancer treatment.

Autophagy-targeted nanoparticles in breast carcinoma: A systematic review.

Breast cancer is a commonly known cancer type and the leading cause of cancer death among females. One of the unresolved problems in cancer treatment is the increased resistance of the tumor to existing treatments, which is a direct result of apoptotic defects. Calculating an alternative to cell death (autophagy) may be the ultimate solution to maximizing cancer cell death. Our aim in this study was to investigate the potential of free nanoparticles (un-drug-loaded) in the induction or inhibition of autophagy and consider this effect on the therapy process. When the studies met the inclusion criteria, the full texts of all relevant articles were carefully examined and classified. Of the 25 articles included in the analysis, carried out on MCF-7, MDA-MB-231, MDA-MB-231-TXSA, MDA-MB-468, SUM1315, and 4T1 cell lines. Twenty in vitro studies and five in vivo/in vitro studies applied five different autophagy tests: Acridine orange, western blot, Cyto-ID Autophagy Detection Kit, confocal microscope, and quantitative polymerase chain reaction. Nanoparticles (NPs) in the basic format, including Ag, Au, Y2 O3 , Se, ZnO, CuO, Al, Fe, vanadium pentoxide, and liposomes, were prepared in the included articles. Three behaviors of NPs related to autophagy were seen: induction, inhibition, and no action. Screened and presented data suggest that most of the involved free NPs (metallic NPs) in this systematic review had reactive oxygen species-mediated pathways with autophagy induction (36%). Also, PI3K/Akt/mTOR and MAPK/ERK signaling pathways were mentioned in just four studies (16%). An impressive percentage of studies (31%) did not examine the NP-related autophagy pathway.

Chemical Profiling and Bioactivity Assessment of Helichrysum italicum (Roth) G. Don. Essential Oil: Exploring Pure Compounds and Synergistic Combinations.

Helichrysum italicum (Roth) G. Don., immortelle, is a plant species used in ethnomedicine and the food industry as a spice added to food, beverages, and bakery products. It has been shown to possess various biological activities, such as antioxidant and antibacterial activity, making it useful as a natural preservative. We investigated the phytochemical profile and biological activity of H. italicum essential oils from wild-grown plant material collected from natural habitats in the Republic of Croatia and Bosnia and Herzegovina. Using high-resolution scanning electron microscopy (SEM), a visual investigation of plant organs (stem, leaf, and flower) was performed, confirming the presence of essential oil reservoirs on the surface of all examined plant organs. Essential oils were isolated by hydrodistillation in the Clevenger apparatus. The chemical composition of the essential oils was determined using the GC-MS analytical technique. Cytotoxic activity tests were performed in vitro on three cell lines: skin (fibroblast), lung, and breast cancer. Using statistical tools, the synergistic and selective effects of H. italicum essential oil on healthy and tumor cells were correlated to chemical composition and cytotoxic activity. The synergistic and antagonistic effects of H. italicum essential oil's individual components were simulated by testing pure compounds and their mixture of cytotoxic activity on fibroblasts and breast cancer cells. The results confirm that essential oil's biological activity is much greater than the sum of the effects of its components. The present data are novel contributions to the body of knowledge on the biological activity of this species used in the food industry.

WNT-Conditioned Mechanism of Exit from Postchemotherapy Shock of Differentiated Tumour Cells.

BACKGROUND: the present study aims to prove or disprove the hypothesis that the state of copy number aberration (CNA) activation of WNT signalling pathway genes accounts for the ability of differentiated tumour cells to emerge from postchemotherapy shock. METHODS: In the first step, the CNA genetic landscape of breast cancer cell lines BT-474, BT-549, MDA-MB-231, MDA-MD-468, MCF7, SK-BR-3 and T47D, which were obtained from ATCC, was examined to rank cell cultures according to the degree of ectopic activation of the WNT signalling pathway. Then two lines of T47D with ectopic activation and BT-474 without activation were selected. The differentiated EpCAM+CD44-CD24-/+ cells of these lines were subjected to IL6 de-differentiation with formation of mammospheres on the background of cisplatin and WNT signalling inhibitor ICG-001. RESULTS: it was found that T47D cells with ectopic WNT signalling activation after cisplatin exposure were dedifferentiated to form mammospheres while BT-474 cells without ectopic WNT-signalling activation did not form mammospheres. The dedifferentiation of T47D cells after cisplatin exposure was completely suppressed by the WNT signalling inhibitor ICG-001. Separately, ICG-001 reduced, but did not abolish, the ability to dedifferentiate in both cell lines. CONCLUSIONS: these data support the hypothesis that the emergence of differentiated tumour cells from postchemotherapy shock after chemotherapy is due to ectopic activation of WNT signalling pathway genes.

Chemical Composition and Biological Activity of Salvia officinalis L. Essential Oil.

In our study, we investigated the chemical composition and cytotoxic activity of essential oils isolated from Dalmatian sage (Salvia officinalis L.) collected along the Adriatic coast of Croatia. Scanning electron microscopy (SEM) was used to examine the morphology of the stem and leaf surfaces. Essential oil excretory glands were detected on both the leaves and stem surfaces. The essential oils were isolated by hydrodistillation, and their chemical composition was determined by gas chromatography and mass spectrometry (GC-MS). Sage essential oils were mixtures of terpene compounds, among which the most common were: α- and ß-thujone, camphor, and 1,8-cineol. Cytotoxic activity was tested using MTS assay on multiple cell lines: normal and immortalized fibroblasts (HF77FA and HDF-Tert), immortalized lung line (BEAS-2B), and breast adenocarcinoma (MDA-MB-231). The growth of treated cells was determined relative to control conditions without treatment. The immortalized lung line was the least resistant to the activity of the essential oils, whereas immortalized fibroblasts were the most resistant. Statistical analysis has connected the cytotoxic effect and chemical composition of the studied essential oils. To the best of our knowledge, this work is the first testing of the cytotoxic activity of S. officinalis EO's on the BEAS-2B, HF77FA, and HDF-Tert cell lines. The presented data on essential oil chemical composition and cytotoxic effect on 4 types of human cells supports pharmacotherapeutic potential this plant is known to have.

Crotamine-based recombinant immunotoxin targeting HER2 for enhanced cancer cell specificity and cytotoxicity.

Crotamine, one of the major toxins present in the venom of the South American rattlesnake Crotalus durissus terrificus, exhibits potent cytotoxic properties and has been suggested for cancer therapy applications. However, its selectivity for cancer cells needs to be improved. This study designed and produced a novel recombinant immunotoxin, HER2(scFv)-CRT, composed of crotamine and single-chain Fv (scFv) derived from trastuzumab targeting human epidermal growth factor receptor 2 (HER2). The recombinant immunotoxin was expressed in Escherichia coli and purified using various chromatographic techniques. The cytotoxicity of HER2(scFv)-CRT was assessed in three breast cancer cell lines, demonstrating enhanced specificity and toxicity in HER2-expressing cells. These findings suggest that the crotamine-based recombinant immunotoxin has the potential to expand the repertoire of recombinant immunotoxin applications in cancer therapy.

PARP Inhibition Sensitizes Breast Cancer Cells to Eribulin.

BACKGROUND: Poly(ADP-ribose) polymerases 1 and 2 (PARP1, 2), and 3 mediate protein modifications that facilitate the recruitment of DNA repair factors to single and double strand breaks. PARP3 is unique in that it is also required for efficient mitotic progression and stabilization of the mitotic spindle. Eribulin, an anti-microtubule agent used clinically to treat breast cancer, exerts its cytotoxicity by altering microtubule dynamics resulting in cell cycle arrest and apoptosis. Herein, we hypothesize that the pan PARP inhibitor olaparib has the potential to enhance the cytotoxicity of eribulin by halting mitosis through inhibition of PARP3. METHODS: The effect of olaparib on eribulin cytotoxicity was assessed using the Sulforhodamine (SRB) assay, with two triple negative breast cancer cell lines and an estrogen receptor positive (ER+)/human epidermal growth factor receptor 2 negative (HER2-) breast cancer cell line. Alteration by the treatments on PARP3 activity and microtubule dynamics were assessed utilizing a chemiluminescent enzymatic assay and immunofluorescence, respectively. The effect of the treatments on cell cycle progression and apoptosis induction were assessed by flow cytometry using propidium iodide and Annexin V staining, respectively. RESULTS: Our results demonstrate that non-cytotoxic concentrations of olaparib sensitize breast cancer cells regardless of ER status. Mechanistically, our results indicate that olaparib potentiates eribulin-induced cell cycle arrest at the G2/M boundary, PARP3 inhibition and microtubule destabilizing resulting in mitotic catastrophe and apoptosis. CONCLUSIONS: In breast cancer (regardless of ER status) settings, treatment outcomes could be improved by the incorporation of olaparib in eribulin treatment regimens.

Effect of aspirin on the TNF-α-mediated cell survival and death pathways in breast cancer.

OBJECTIVES: Aspirin is an anti-inflammatory drug commonly used as an analgesic and in cardiovascular disorders. However, many studies have highlighted its anti-cancer properties, especially in colorectal, lung, head and neck, and breast cancers. In this work, we tried to study the effect of aspirin on the TNF-α-mediated cell survival and death pathways in two cell lines representing two different subtypes of breast cancer. TNF-α-mediated stimulation of a cell can result in its proliferation via the NF-κB pathway or its death via either apoptosis or a programmed form of necrosis called necroptosis. The latter is believed to come into the picture only when apoptosis is inhibited. METHODS: In this work, we studied the effect of aspirin on the TNF-α-mediated cell survival pathway and observed a decrease in expression of the NF-κB pathway regulators, its nuclear translocation, and phosphorylation in a dose-dependent manner. The effect of aspirin on the TNF-α-mediated cell death showed significant cytotoxicity at the higher doses (5-20 mM) of aspirin in both the breast cancer cell lines. The effect of aspirin on necroptosis was investigated after stimulating the cells with TNF-α and inhibiting apoptosis using Z-VAD-FMK. RESULTS: Though no significant effect was noted in breast cancer cell lines, the above protocol successfully induced necroptosis in L929, i.e., a positive control cell line for necroptosis having an intact necroptosis machinery. Even when combined with the chemotherapeutic drugs, the above regime failed to induce any significant necroptosis in breast cancer cells but was found effective in L929. CONCLUSIONS: Overall, the findings show that while aspirin has the potential to inhibit the TNF-α-mediated cell survival pathway, it does not help sensitize breast cancer cells to necroptotic cell death induction.

Synthesis and Structure-Activity Relationship Studies of Novel Aryl Sulfonamides and Their Activity against Human Breast Cancer Cell Lines.

A series of structural analogs of aryl sulfonamide hybrid compounds were synthesised and their cytotoxic activity was evaluated against three human breast cancer cell lines (MCF-7, MDA-MB-231 and Hs 578T). The compounds were designed through electronic, hydrophobic and steric modifications using the chemical structure of N-{4-[(2-hydroxy-3-methoxy-5-propylphenyl)sulfamoyl]phenyl}acetamide (referred to as compound 7) as a starting point to then assess a structure-activity relationship (SAR) study. From the data generated, we observed that compounds 9, 10 and 11 (which have modifications in the substituents of the aryl sulfonamide), efficiently reduced the cell viability of MCF-7 and MDA-MB-231 cell cultures. Based on initial data, we selected compounds 10 and 11 for further investigations into their antiproliferative and/or cytotoxic profile against MDA-MB-231 cells, and we noted that compound 10 was the most promising compound in the series. Compound 10 promoted morphological changes and altered the dynamics of cell cycle progression in MDA-MB-231 cells, inducing arrest in G1/S transition. Taken together, these results show that the dihydroeugenol-aryl-sulfonamide hybrid compound 10 (which has an electron withdrawing nitro group) displays promising antiproliferative activity against MDA-MB-231 cell lines.

Antitumor activity of the protein kinase inhibitor 1-(ß-D-2'-deoxyribofuranosyl)-4,5,6,7-tetrabromo- 1H-benzimidazole in breast cancer cell lines.

BACKGROUND: The protein kinases CK2 and PIM-1 are involved in cell proliferation and survival, the cell cycle, and drug resistance, and they are found overexpressed in virtually all types of human cancer, including breast cancer. In this study, we investigated the antitumor activity of a deoxynucleoside derivative, the protein kinase inhibitor compound 1-(ß-D-2'-deoxyribofuranosyl)-4,5,6,7-tetrabromo-1H-benzimidazole (K164, also termed TDB), inter alia CK2 and PIM-1, on breast cancer cell lines (MDA-MB-231, MCF-7, and SK-BR-3). METHODS: An evaluation of the cytotoxic and proapoptotic effects, mitochondrial membrane potential (ΔΨm), and cell cycle progression was performed using an MTT assay, flow cytometry, and microscopic analysis. The Western blotting method was used to analyze the level of proteins important for the survival of breast cancer cells and proteins phosphorylated by the CK2 and PIM-1 kinases. RESULTS: The examined compound demonstrated the inhibition of cell viability in all the tested cell lines and apoptotic activity, especially in the MCF-7 and SK-BR-3 cells. Changes in the mitochondrial membrane potential (ΔΨm), cell cycle progression, and the level of the proteins studied were also observed. CONCLUSIONS: The investigated CK2 and PIM-1 kinase inhibitor K164 is a promising compound that can be considered a potential agent in targeted therapy in selected types of breast cancer; therefore, further research is necessary.