Differential effects of doxorubicin treatment on cell cycle arrest and Skp2 expression in breast cancer cells

Synchronized Chemotherapy/Photothermal Therapy/Sonodynamic Therapy of Human Triple-Negative and Estrogen Receptor-Positive Breast Cancer Cells Using a Doxorubicin-Gold Nanoclusters-Albumin Nanobioconjugate

OBJECTIVE

Novel strategies for treating triple-negative breast cancer (TNBC) are ongoing because of the lack of standard-of-care treatment. Nanoframed materials with a protein pillar are considered a valuable tool for designing multigoals of energy-absorbing/medication cargo and are a bridge to cross-conventional treatment strategies.

METHODS

Nanobioconjugates of gold nanoclusters-bovine serum albumin (AuNCs-BSA) and doxorubicin-AuNCs-BSA (Dox-AuNCs-BSA) were prepared and employed as a simultaneous double photosensitizer/sonosensitizer and triple chemotherapeutic/photosensitizer/sonosensitizer, respectively.

RESULTS

The highly stable AuNCs-BSA and Dox-AuNCs-BSA have ζ potentials of -29 and -18 mV, respectively, and represent valuable photothermal and sonodynamic activities for the combination of photothermal therapy and sonodynamic therapy (PTT/SDT) and synchronized chemotherapy/photothermal therapy/sonodynamic therapy (CTX/PTT/SDT) of human TNBC cells, respectively. The efficiency of photothermal conversion of AuNCs-BSA was calculated to be a promising value of 32.9%. AuNCs-BSA and Dox-AuNCs-BSA were activated on either laser light irradiation or ultrasound exposure with the highest efficiency on the combination of both types of radiation. CTX/PTT/SDT of MCF-7 and MDA-MB-231 breast cancer cell lines by Dox-AuNCs-BSA were evaluated with the MTT cell proliferation assay and found to progress synergistically.

CONCLUSION

Results of the MTT assay, detection of the generation of intracellular reactive oxygen species and occurrence of apoptosis in the cells confirmed that CTX/PTT/SDT by Dox-AuNCs-BSA was attained with lower needed doses of the drug and improved tumor cell ablation, which would result in the enhancement of therapeutic efficacy and overcoming of therapeutic resistance.

SKping cell cycle regulation: role of ubiquitin ligase SKP2 in hematological malignancies

SKP2 (S-phase kinase-associated protein 2) is a member of the F-box family of substrate-recognition subunits in the SCF ubiquitin-protein ligase complexes. It is associated with ubiquitin-mediated degradation in the mammalian cell cycle components and other target proteins involved in cell cycle progression, signal transduction, and transcription. Being an oncogene in solid tumors and hematological malignancies, it is frequently associated with drug resistance and poor disease outcomes. In the current review, we discussed the novel role of SKP2 in different hematological malignancies. Further, we performed a limited in-silico analysis to establish the involvement of SKP2 in a few publicly available cancer datasets. Interestingly, our study identified Skp2 expression to be altered in a cancer-specific manner. While it was found to be overexpressed in several cancer types, few cancer showed a down-regulation in SKP2. Our review provides evidence for developing novel SKP2 inhibitors in hematological malignancies. We also investigated the effect of SKP2 status on survival and disease progression. In addition, the role of miRNA and its associated families in regulating Skp2 expression was explored. Subsequently, we predicted common miRNAs against Skp2 genes by using miRNA-predication tools. Finally, we discussed current approaches and future prospective approaches to target the Skp2 gene by using different drugs and miRNA-based therapeutics applications in translational research.

Does insulin make breast cancer cells resistant to doxorubicin toxicity?

The effects of insulin on the doxorubicin (Dox) sensitivity of breast cancer cell line MCF-7 and its Dox-resistant counterpart MCF-7/Dox were studied and glucose metabolism, content of essential minerals, and the expression of several microRNAs in these cells upon exposure to insulin and Dox were compared. Cell viability colorimetric assay, colorimetric enzymatic technique, flow cytometry, immunocytochemical techniques, inductively-coupled plasma atomic emission spectroscopy, and quantitative polymerase chain reaction were used in the study. We found that insulin in high concentration significantly suppressed Dox toxicity, especially in parental MCF-7 cell line. The increase in proliferative activity triggered by insulin in MCF-7 but not MCF-7/Dox cells occurred in the setting of the increased level of specific binding sites for insulin and increased glucose uptake. Insulin treatment of MCF-7 cells in low and high concentrations resulted in the increase of Mg, Ca, and Zn content while in DOX-resistant cells, only Mg content increased upon exposure to insulin. High concentration of insulin increased the expression of kinase Akt1, P-glycoprotein 1 (P-gp1) and DNA excision repair protein ERCC-1 in MCF-7 cells, while in MCF-7/Dox cells, Akt1 expression decreased, and cytoplasmic expression of P-gp1 increased. In addition, insulin treatment affected expression of miR-122-5p, miR-133a-3p, miR-200b-3p, and miR-320a-3p. The decreased manifestation of biological effects of insulin in Dox-resistant cells could be partly explained by the different patterns of energy metabolism in MCF-7 cells and their Dox-resistant counterpart.

MAP3K1 expression is associated with progression and poor prognosis of hormone receptor-positive, HER2-negative early-stage breast cancer

PURPOSE

In this study, we assessed whether the overexpression of MAP3K1 promotes the proliferation, migration, and invasion of breast cancer cells, which affect the prognosis of hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative early stage breast cancer.

METHODS

Two HR-positive, HER2-negative breast cancer cell lines (MCF7 and T-47D) overexpressing MAP3K1 were transfected with two MAP3K1 short hairpin RNA plasmids (shMAP3K1 [#3] and shMAP3K1 [#5]). The proliferation, migration, and invasion of these cells were then examined. We assessed whether shMAP3K1 affects the cell cycle, levels of downstream signaling molecules (ERK, JNK, p38 MAPK, and NF-κB), and sensitivity to chemotherapeutic and hormonal agents. To assess the anti-tumor effect of MAP3K1 knockdown in the breast cancer orthotopic model, MCF7 and T-47D cells treated with or without shMAP3K1 (#3) and shMAP3K1 (#5) were inoculated into the mammary fat pads of mice. In total, 182 patients with HR-positive, HER2-negative T1 and T2 breast cancer and 0-3 nodal metastases were included. Additionally, 73 patients with T1 and T2 breast cancer and negative nodes who received adjuvant endocrine therapy alone were selected as an independent validation cohort.

RESULTS

In both cell lines, shMAP3K1 (#3) and shMAP3K1 (#5) significantly reduced cell growth, migration, and invasion by downregulating MMP-9 and by blocking the G2/M phase of the cell cycle and its regulatory molecule cyclin B1. Moreover, both shMAP3K1 (#3) and shMAP3K1 (#5) downregulated ERK-, JNK-, p38 MAPK-, and NF-κB-dependent gene transcription and enhanced the sensitivity of both cell lines to doxorubicin, docetaxel, and tamoxifen. We observed that both shMAP3K1 (#3) and shMAP3K1 (#5) inhibited tumor growth compared with that in the scrambled group of MCF7 and T-47D cell orthotopic tumors. Patients with MAP3K1 overexpression exhibited significantly poorer 10-year disease-free survival (DFS) (70.4% vs. 88.6%, p = 0.003) and overall survival (OS) (81.9% vs. 96.3%, p = 0.001) than those without MAP3K1 overexpression. Furthermore, phospho-ERK (p < 0.001) and phospho-JNK (p < 0.001) expressions were significantly associated with MAP3K1 expression, and both phospho-ERK and phospho-JNK expressions were significantly correlated with poor 10-year DFS and OS. These biological findings, including a significant association between DFS and OS, and the expressions of MAP3K1, phospho-ERK, and phospho-JNK were further validated in an independent cohort. Multivariate analysis identified MAP3K1 expression as an independent poor prognostic factor for DFS and OS.

CONCLUSION

Our results indicate that the overexpression of MAP3K1 plays a major role in the poor prognosis of HR-positive, HER2-negative early stage breast cancer.

Targeted delivery of paclitaxel drug using polymer-coated magnetic nanoparticles for fibrosarcoma therapy: in vitro and in vivo studies

Fibrosarcoma is a rare type of cancer that affects cells known as fibroblasts that are malignant, locally recurring, and spreading tumor in fibrous tissue. In this work, an iron plate immersed in an aqueous solution of double added deionized water, supplemented with potassium permanganate solution (KMnO₄) was carried out by the pulsed laser ablation in liquid method (PLAIL). Superparamagnetic iron oxide nanoparticles (SPIONs) were synthesized using different laser wavelengths (1064, 532, and 266 nm) at a fluence of 28 J/cm² with 100 shots of the iron plate to control the concentration, shape and size of the prepared high-stability SPIONs. The drug nanocarrier was synthesized by coating SPION with paclitaxel (PTX)-loaded chitosan (Cs) and polyethylene glycol (PEG). This nanosystem was functionalized by receptors that target folate (FA). The physiochemical characteristics of SPION@Cs-PTX-PEG-FA nanoparticles were evaluated and confirmed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-Ray diffraction (XRD), atomic force microscopy (AFM), and dynamic light scattering (DLS) methods. Cell internalization, cytotoxicity assay (MTT), apoptosis induction, and gene expression of SPION@Cs-PTX-PEG-FA were estimated in fibrosarcoma cell lines, respectively. In vivo studies used BALB/c tumor-bearing mice. The results showed that SPION@Cs-PTX-PEG-FA exhibited suitable physical stability, spherical shape, desirable size, and charge. SPION@Cs-PTX-PEG-FA inhibited proliferation and induced apoptosis of cancer cells (P < 0.01). The results of the in vivo study showed that SPION@Cs-PTX-PEG-FA significantly decreased tumor size compared to free PTX and control samples (P < 0.05), leading to longer survival, significantly increased splenocyte proliferation and IFN-γ level, and significantly decreased the level of IL-4. All of these findings indicated the potential of SPION@Cs-PTX-PEG-FA as an antitumor therapeutic agent.

Doxorubicin-An Agent with Multiple Mechanisms of Anticancer Activity

Doxorubicin (DOX) constitutes the major constituent of anti-cancer treatment regimens currently in clinical use. However, the precise mechanisms of DOX's action are not fully understood. Emerging evidence points to the pleiotropic anticancer activity of DOX, including its contribution to DNA damage, reactive oxygen species (ROS) production, apoptosis, senescence, autophagy, ferroptosis, and pyroptosis induction, as well as its immunomodulatory role. This review aims to collect information on the anticancer mechanisms of DOX as well as its influence on anti-tumor immune response, providing a rationale behind the importance of DOX in modern cancer therapy.

A comparative study of 5- fluorouracil, doxorubicin, methotrexate, paclitaxel for their inhibition ability for Mpro of nCoV: Molecular docking and molecular dynamics simulations

A new corona virus (nCoV) is aetiological agent responsible for the viral pneumonia epidemic. Three is no specific therapeutic medicines available for the treatment of this condition and also effective treatment choices are few. In this work author tried to investigate some repurposing drug such as 5- fluorouracil, doxorubicin, methotrexate and paclitaxel against the main protease (Mpro) of nCoV by the computational model. Molecular docking was performed to screen out the best compound and doxorubicin was found to have minimum binding energy −121.89 kcal/mol. To further study, MD simulations were performed at 300 K and the result successfully corroborate the energy obtained by molecular docking. Temperature dependent MD simulation of the best molecule that is doxorubicin obtained from docking result was performed to check the variation in structural changes in Mpro of nCoV at 290 K, 310 K, 320 K and 325 K. It is sound that doxorubicin binds effectively with Mpro of nCoV at 290 K. Further ADME properties of the 5- fluorouracil, doxorubicin, methotrexate and paclitaxel were also evaluated to understand the bioavailability.

Sampling and Analysis of Low-Molecular-Weight Volatile Metabolites in Cellular Headspace and Mouse Breath

Volatile compounds, abundant in breath, can be used to accurately diagnose and monitor a range of medical conditions. This offers a noninvasive, low-cost approach with screening applications; however, the uptake of this diagnostic approach has been limited by conflicting published outcomes. Most published reports rely on large scale screening of the public, at single time points and without reference to ambient air. Here, we present a novel approach to volatile sampling from cellular headspace and mouse breath that incorporates multi-time-point analysis and ambient air subtraction revealing compound flux as an effective proxy of active metabolism. This approach to investigating breath volatiles offers a new avenue for disease biomarker discovery and diagnosis. Using gas chromatography mass spectrometry (GC/MS), we focus on low molecular weight, metabolic substrate/by-product compounds and demonstrate that this noninvasive technique is sensitive (reproducible at ~1 µg cellular protein, or ~500,000 cells) and capable of precisely determining cell type, status and treatment. Isolated cellular models represent components of larger mammalian systems, and we show that stress- and pathology-indicative compounds are detectable in mice, supporting further investigation using this methodology as a tool to identify volatile targets in human patients.

Development and evaluation of core-shell nanocarrier system for enhancing the cytotoxicity of doxorubicin/ metformin combination against breast cancer cell line

Breast cancer is the most invasive and life-threatening cancer in women. The treatment options are usually a combination of mastectomy, radiation therapy, hormonal therapy and chemotherapy. As a standard practice, doxorubicin (DOX) is one of the commonly used drugs for breast cancer treatment. However, DOX is known to have many harmful adverse effects including its cardiotoxicity. Hence, recent reports used metformin (MET), an anti-diabetic drug, as an adjuvant therapy to decrease the severity of DOX's adverse effects and to improve its ultimate therapeutic outcome. The current study is aimed at co-loading and enhancing the encapsulation efficiency of the hydrophilic DOX and MET in poly(lactic-co-glycolic acid) (PLGA) nanocapsules (NCs) with oil core for breast cancer treatment. The NCs were developed by single emulsification-solvent diffusion technique, and were optimized through using two types of oils, pluronics and PLGA (50:50) of different molecular weights followed by various physicochemical characterizations. The obtained DOX/MET-loaded NCs showed the size and polydispersity index (PDI) of 203.0 ± 3.4 nm and 0.081 ± 0.03, respectively with a surface charge of -2.15 ± 0.2 mV. The entrapment efficiency of DOX and MET were about 93.7% ± 2.9 and 70% ± 1.6, respectively. The developed PLGA core-shell NCs successfully sustained the DOX/MET release for more than 30 days. The in-vitro results showed a significant enhancement in DOX cytotoxic effect as well as a duplication in its apoptotic effect upon addition of MET for both free DOX/MET combination and DOX/MET-loaded PLGA NCs against MCF-7. Besides, flow cytometry demonstrated that the DOX/MET-loaded NCs possess their antitumor effect by preventing DNA replication and cell division. This study provides a promising facile, rapid and reproducible single emulsification-solvent diffusion technique for improving the encapsulation and release of hydrophilic drugs in nanocapsules for biomedical applications.

Intranasal Delivery in Glioblastoma treatment: Prospective Molecular Treatment Modalities

Glioblastoma multiforme (GBM) is rare and fatal glioma with limited treatment options. Treatments provide minimal improvement in prognosis and only 6.8% of GBM patients have a life expectancy greater than five years. Surgical resection of this malignant glioma is difficult due to its highly invasive nature and follow-up radiotherapy with concomitant temozolomide, the currently approved standard of care, and will only extend the life of patients by a few months. It has been nearly two decades since the approval of temozolomide and there have been no clinically relevant major breakthroughs since, painting a dismal picture for patients with GBM. Although the future of GBM management seems bleak, there are many new treatment options on the horizon that propose methods of delivery to circumvent current limitations in the standard of care, i.e., the blood brain barrier and treatment resistance mechanisms. The nose is a highly accessible non-invasive route of delivery that has been incorporated into many investigational studies within the past five years and potentially paves the path to a brighter future for the management of GBM. Intranasal administration has its limitations however, as drugs can be degraded and/or fail to reach the site of action. This has prompted many studies for implementation of nanoparticle systems to overcome these limitations and to accurately deliver drugs to the site of action. This review highlights the advances in intranasal therapy delivery and impact of nanotechnology in the management of GBM and discusses potential treatment modalities that show promise for further investigation.

Fluorescent Silica Nanoparticles Targeting Mitochondria: Trafficking in Myeloid Cells and Application as Doxorubicin Delivery System in Breast Cancer Cells

Fluorescent silica nanoparticles (SiNPs) appear to be a promising imaging platform, showing a specific subcellular localization. In the present study, we first investigated their preferential mitochondrial targeting in myeloid cells, by flow cytometry, confocal microscopy and TEM on both cells and isolated mitochondria, to acquire knowledge in imaging combined with therapeutic applications. Then, we conjugated SiNPs to one of the most used anticancer drugs, doxorubicin (DOX). As an anticancer agent, DOX has high efficacy but also an elevated systemic toxicity, causing multiple side effects. Nanostructures are usually employed to increase the drug circulation time and accumulation in target tissues, reducing undesired cytotoxicity. We tested these functionalized SiNPs (DOX-NPs) on breast cancer cell line MCF-7. We evaluated DOX-NP cytotoxicity, the effect on the cell cycle and on the expression of CD44 antigen, a molecule involved in adhesion and in tumor invasion, comparing DOX-NP to free DOX and stand-alone SiNPs. We found a specific ability to release a minor amount of CD44+ extracellular vesicles (EVs), from both CD81 negative and CD81 positive pools. Modulating the levels of CD44 at the cell surface in cancer cells is thus of great importance for disrupting the signaling pathways that favor tumor progression.

A Novel Role for RNF126 in the Promotion of G2 Arrest via Interaction With 14-3-3σ

PURPOSE

Cell cycle checkpoints and DNA repair are important for cell survival after exogenous DNA damage. Both rapid blockage of G2 to M phase transition in the cell cycle and the maintenance of relatively slow G2 arrest are critical to protect cells from lethal ionizing radiation (IR). Checkpoint kinase 1 is pivotal in blocking the transition from G2 to M phases in response to IR. The 14-3-3σ protein is important for IR-induced G2 arrest maintenance in which p53-dependent 14-3-3σ transcription is involved. It has been demonstrated that Ring finger protein 126 (RNF126), an E3 ligase, is required to upregulate checkpoint kinase 1 expression. Thus, our goal was to study the role of RNF126 in the G2/M phase checkpoint.

METHODS AND MATERIALS

The transition from G2 to M phases and G2 accumulation in response to IR were determined by flow cytometry through staining with phospho-histone H3 (pS10) antibody and propidium iodide, respectively. The interaction of RNF126 and 14-3-3σ was determined by GST-pulldown and coimmunoprecipitation assays. The stability of RNF126 and 14-3-3σ was determined by cycloheximide-based stability assay and ubiquitination detection by coimmunoprecipitation. The sequestering of cyclin-dependent kinase 1 and cyclin B1 from the nucleus was determined by immunofluorescence staining.

RESULTS

RNF126 knockdown had no impact on the IR-induced transient blockage of G2 to M but impaired IR-induced G2 arrest maintenance in cells with or without wild-type p53. Mechanistically, RNF126 binds 14-3-3σ and prevents both proteins from ubiquitination-mediated degradation. Last, RNF126 is required for enforcing the cytoplasmic sequestration of cyclin B1 and cyclin-dependent kinase 1 proteins in response to IR.

CONCLUSIONS

RNF126 promotes G2 arrest via interaction with 14-3-3σ in response to IR. Our study revealed a novel role for RNF126 in promoting G2 arrest, providing a new target for cancer treatment.

Targeting Oxidative Stress, NLRP3 Inflammasome, and Autophagy by Fraxetin to Combat Doxorubicin-Induced Cardiotoxicity

Doxorubicin belongs to the class of anthracycline antibiotics that is widely used in the treatment protocols of a wide range of malignancies. The major deleterious effect of doxorubicin use is the possible occurrence of cardiotoxicity. This study aimed to delineate the possible effects of targeting oxidative stress, NLRP3 inflammasome, and autophagy by fraxetin on doxorubicin-induced cardiac dysfunction in rats. In a model of doxorubicin-induced cardiotoxicity, the effects of different doses of fraxetin were assessed by determination of biochemical, histopathological, immunohistochemical, and electron microscopic changes. Fraxetin, in a dose-dependent manner, was found to have the ability to mitigate the harmful effects of oxidative stress and inflammation on myocardial muscles with significant decrease in NLRP3 inflammasome, augmentation of autophagy, and amelioration of the apoptotic signaling pathways. In addition, fraxetin, in a dose-dependent manner, had the ability to combat the echocardiographic, histopathological, immunohistochemical, and electron microscopic changes induced by doxorubicin in cardiomyocytes. As a result, fraxetin may be put into consideration as a new adjuvant line of therapy on the way to mitigate doxorubicin-induced cardiotoxicity.

Suppression of Estrogen Receptor Alpha Inhibits Cell Proliferation, Differentiation and Enhances the Chemosensitivity of P53-Positive U2OS Osteosarcoma Cell

Osteosarcoma is a highly malignant musculoskeletal tumor that is commonly noticed in adolescent children, young children, and elderly adults. Due to advances in surgery, chemotherapy and imaging technology, survival rates have improved to 70–80%, but chemical treatments do not enhance patient survival; in addition, the survival rate after chemical treatments is still low. The most obvious clinical feature of osteosarcoma is new bone formation, which is called “sun burst”. Estrogen receptor alpha (ERα) is an essential feature of osteogenesis and regulates cell growth in various tumors, including osteosarcoma. In this study, we sought to investigate the role of ERα in osteosarcoma and to determine if ERα can be used as a target to facilitate the chemosensitivity of osteosarcoma to current treatments. The growth rate of each cell clone was assayed by MTT and trypan blue cell counting, and cell cycle analysis was conducted by flow cytometry. Osteogenic differentiation was induced by osteogenic induction medium and quantified by ARS staining. The effects of ERα on the chemoresponse of OS cells treated with doxorubicin were evaluated by colony formation assay. Mechanistic studies were conducted by examining the levels of proteins by Western blot. The role of ERα on OS prognosis was investigated by an immunohistochemical analysis of OS tissue array. The results showed an impaired growth rate and a decreased osteogenesis ability in the ERα-silenced P53(+) OS cell line U2OS, but not in P53(−) SAOS2 cells, compared with the parental cell line. Cotreatment with tamoxifen, an estrogen receptor inhibitor, increased the sensitivity to doxorubicin, which decreased the colony formation of P53(+) U2OS cells. Cell cycle arrest in the S phase was observed in P53(+) U2OS cells cotreated with low doses of doxorubicin and tamoxifen, while increased levels of apoptosis factors indicated cell death. Moreover, patients with ER−/P53(+) U2OS showed better chemoresponse rates (necrosis rate > 90%) and impaired tumor sizes, which were compatible with the findings of basic research. Taken together, ERα may be a potential target of the current treatments for osteosarcoma that can control tumor growth and improve chemosensitivity. In addition, the expression of ERα in osteosarcoma can be a prognostic factor to predict the response to chemotherapy.

Albumin-Based Nanoparticles for the Delivery of Doxorubicin in Breast Cancer

Albumin-based nanoparticles are an emerging platform for the delivery of various chemotherapeutics because of their biocompatibility, safety, and ease of surface modification for specific targeting. The most widely used method for the preparation of albumin nanoparticles is by desolvation process using glutaraldehyde (GLU) as a cross-linker. However, limitations of GLU like toxicity and interaction with drugs force the need for alternative cross-linkers. In the present study, several cross-linking systems were evaluated for the preparation of Bovine Serum Albumin (BSA) nanoparticles (ABNs) encapsulating Doxorubicin (Dox). Based on the results obtained from morphological characterization, in vitro release, and therapeutic efficacy in cells, N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP)-modified ABNs (ABN-SPDP) was chosen. Since ABN-SPDP are formed with disulfide linkage, the drug release is facilitated under a highly reducing environment present in the tumor sites. The cytotoxicity studies of those ABN-SPDP were performed in three different breast cell lines, highlighting the mechanism of cell death. The Dox-encapsulated ABN-SPDP showed toxicity in both the breast cancer cells (MCF-7 and MDA-MB-231), but, remarkably, a negligible effect was observed in non-tumoral MCF-10A cells. In addition to the hydrophilic Dox, this system could be used as a carrier for hydrophobic drugs like SN38. The system could be employed for the preparation of nanoparticles based on human serum albumin (HSA), which further enhances the feasibility of this system for clinical use. Hence, the albumin nanoparticles developed herein present an excellent potential for delivering various drugs in cancer therapy.

Sublethal hyperthermia enhances anticancer activity of doxorubicin in chronically hypoxic HepG2 cells through ROS-dependent mechanism

Thermal ablation in combination with transarterial chemoembolization (TACE) has been reported to exert a more powerful antitumor effect than thermal ablation alone in hepatocellular carcinoma patients. However, the underlying mechanisms remain unclear. The purpose of the present study was to evaluate whether sublethal hyperthermia encountered in the periablation zone during thermal ablation enhances the anticancer activity of doxorubicin in chronically hypoxic (encountered in the tumor area after TACE) liver cancer cells and to explore the underlying mechanisms. In the present study, HepG2 cells precultured under chronic hypoxic conditions (1% oxygen) were treated in a 42°C water bath for 15 or 30 min, followed by incubation with doxorubicin. Assays were then performed to determine intracellular uptake of doxorubicin, cell viability, apoptosis, cell cycle, mitochondrial membrane potential (MMP), reactive oxygen species (ROS), and total antioxidant capacity. The results confirmed that sublethal hyperthermia enhanced the intracellular uptake of doxorubicin into hypoxic HepG2 cells. Hyperthermia combined with doxorubicin led to a greater inhibition of cell viability and increased apoptosis in hypoxic HepG2 cells as compared with hyperthermia or doxorubicin alone. In addition, the combination induced apoptosis by increasing ROS and causing disruption of MMP. Pretreatment with the ROS scavenger N-acetyl cysteine significantly inhibited the apoptotic response, suggesting that cell death is ROS-dependent. These findings suggested that sublethal hyperthermia enhances the anticancer activity of doxorubicin in hypoxic HepG2 cells via a ROS-dependent mechanism.

Interleukin-32θ Triggers Cellular Senescence and Reduces Sensitivity to Doxorubicin-Mediated Cytotoxicity in MDA-MB-231 Cells

The recently discovered interleukin (IL)- 32 isoform IL-32θ exerts anti-metastatic effects in the breast tumor microenvironment. However, the involvement of IL-32θ in breast cancer cell proliferation is not yet fully understood; therefore, the current study aimed to determine how IL-32θ affects cancer cell growth and evaluated the responses of IL-32θ-expressing cells to other cancer therapy. We compared the functions of IL-32θ in triple-negative breast cancer MDA-MB-231 cells that stably express IL-32θ, with MDA-MB-231 cells transfected with a mock vector. Slower growth was observed in cells expressing IL-32θ than in control cells, and changes were noted in nuclear morphology, mitotic division, and nucleolar size between the two groups of cells. Interleukin-32θ significantly reduced the colony-forming ability of MDA-MB-231 cells and induced permanent cell cycle arrest at the G1 phase. Long-term IL-32θ accumulation triggered permanent senescence and chromosomal instability in MDA-MB-231 cells. Genotoxic drug doxorubicin (DR) reduced the viability of MDA-MB-231 cells not expressing IL-32θ more than in cells expressing IL-32θ. Overall, these findings suggest that IL-32θ exerts antiproliferative effects in breast cancer cells and initiates senescence, which may cause DR resistance. Therefore, targeting IL-32θ in combination with DR treatment may not be suitable for treating metastatic breast cancer.

Bimetallic Au@Pd nanodendrite system incorporating multimodal intracellular imaging for improved doxorubicin antitumor efficiency

The sufficient accumulation of drugs is crucial for efficient treatment in a complex tumor microenvironment. Drug delivery systems (DDS) with high surface area and selective cytotoxicity present a novel approach to mitigate insufficient drug loading for improved therapeutic response. Herein, a doxorubicin-conjugated bimetallic gold-core palladium-shell nanocarrier with multiple dense arrays of branches (Au@PdNDs.PEG/DOX) was characterized and its efficacy against breast adenocarcinoma (MCF-7) and lung adenocarcinoma (A549) cells were evaluated. Enhanced darkfield and hyperspectral imaging (HSI) microscopy were used to study the intracellular uptake and accumulation of the DOX-loaded nanodendrites A fascinating data from a 3D-CytoViva fluorescence imaging technique provided information about the dynamics of localization and distribution of the nanocarrier. In vitro cytotoxicity assays indicated that Au@PdNDs.PEG/DOX inhibited the proliferative effects of MCF-7 cells at equivalent IC₅₀ dosage compared to DOX alone. The nanocarrier triggered higher induction of apoptosis proved by a time-dependent phosphatidylserine V release, cell cycle arrest, and flow cytometry analysis. Moreover, the cell cycle phase proportion increase suggests that the enhanced apoptotic effect induced by Au@PdNDs.PEG/DOX was via a G2/M phase arrest. Thus, this study demonstrated the potential of dendritic nanoparticles to improve DOX therapeutic efficiency and plasmonic-mediated intracellular imaging as a suitable theranostic platform for deployment in nanomedicine.

Combining Dextran Conjugates with Stimuli-Responsive and Folate-Targeting Activity: A New Class of Multifunctional Nanoparticles for Cancer Therapy

Nanoparticles with active-targeting and stimuli-responsive behavior are a promising class of engineered materials able to recognize the site of cancer disease, targeting the drug release and limiting side effects in the healthy organs. In this work, new dual pH/redox-responsive nanoparticles with affinity for folate receptors were prepared by the combination of two amphiphilic dextran (DEX) derivatives. DEXFA conjugate was obtained by covalent coupling of the polysaccharide with folic acid (FA), whereas DEXssPEGCOOH derived from a reductive amination step of DEX was followed by condensation with polyethylene glycol 600. After self-assembling, nanoparticles with a mean size of 50 nm, able to be destabilized in acidic pH and reducing media, were obtained. Doxorubicin was loaded during the self-assembling process, and the release experiments showed the ability of the proposed system to modulate the drug release in response to different pH and redox conditions. Finally, the viability and uptake experiments on healthy (MCF-10A) and metastatic cancer (MDA-MB-231) cells proved the potential applicability of the proposed system as a new drug vector in cancer therapy.

In vitro to Clinical Translation of Combinatorial Effects of Doxorubicin and Abemaciclib in Rb-Positive Triple Negative Breast Cancer: A Systems-Based Pharmacokinetic/Pharmacodynamic Modeling Approach

Background

Doxorubicin (DOX) and its pegylated liposomal formulation (L_DOX) are the standard of care for triple-negative breast cancer (TNBC). However, resistance to DOX often occurs, motivating the search for alternative treatment approaches. The retinoblastoma protein (Rb) is a potential pharmacological target for TNBC treatment since its expression has been associated with resistance to DOX-based therapy.

Methods

DOX (0.01–20 μM) combination with abemaciclib (ABE, 1–6 μM) was evaluated over 72 hours on Rb-positive (MDA-MB-231) and Rb-negative (MDA-MB-468) TNBC cells. Combination indices (CI) for DOX+ABE were calculated using Compusyn software. The TNBC cell viability time-course and fold-change from the control of phosphorylated-Rb (pRb) protein expression were measured with CCK8-kit and enzyme-linked immunosorbent assay. A cell-based pharmacodynamic (PD) model was developed, where pRb protein dynamics drove cell viability response. Clinical pharmacokinetic (PK) models for DOX, L_DOX, and ABE were developed using data extracted from the literature. After scaling cancer cell growth to clinical TNBC tumor growth, the time-to-tumor progression (TTP) was predicted for human dosing regimens of DOX, ABE, and DOX+ABE.

Results

DOX and ABE combinations were synergistic (CI<1) in MDA-MB-231 and antagonistic (CI>1) in MDA-MB-468. The maximum inhibitory effects (Imax) for both drugs were set to one. The drug concentrations producing 50% of Imax for DOX and ABE were 0.565 and 2.31 μM (MDA-MB-231) and 0.121 and 1.61 μM (MDA-MB-468). The first-orders rate constants of abemaciclib absorption (k_a) and doxorubicin release from L_DOX (k_Rel) were estimated at 0.31 and 0.013 h⁻¹. Their linear clearances were 21.7 (ABE) and 32.1 L/h (DOX). The estimated TTP for intravenous DOX (75 mg/m2 every 21 days), intravenous L_DOX (50 mg/m² every 28 days), and oral ABE (200 mg twice a day) were 125, 31.2, and 8.6 days shorter than drug-free control. The TTP for DOX+ABE and L_DOX+ABE were 312 days and 47.5 days shorter than control, both larger than single-agent DOX, suggesting improved activity with the DOX+ABE combination.

Conclusion

The developed translational systems-based PK/PD model provides an in vitro-to-clinic modeling platform for DOX+ABE in TNBC. Although model-based simulations suggest improved outcomes with combination over monotherapy, tumor relapse was not prevented with the combination. Hence, DOX+ABE may not be an effective treatment combination for TNBC.

Liposomes co-encapsulating doxorubicin and glucoevatromonoside derivative induce synergic cytotoxic response against breast cancer cell lines

Cancer is one of the main causes of death in the world and thus a global public health problem. Among the treatments available for cancer are surgery, radiotherapy, and chemotherapy. Currently, there is increased interest in the combination of two or more antitumor agents to achieve a synergistic effect in cancer therapy. Doxorubicin (DOX), a chemotherapeutic which has a potent antineoplastic action, has been used in the treatment of various tumors. However, the use of DOX is limited, mainly due to the cardiotoxicity. Therefore, nanostructured systems, such as liposomes, have been developed to carry this drug and target the tumor region, since tumor tissues present enhanced permeability and retention for nanosystems. Cardiac glycosides, such as digitoxin, have recently shown great antitumor potential despite the low therapeutic index which may limit their use. Furthermore, some compounds of this class have low water solubility, which makes their in vivo administration difficult. In this context, liposomes represent a valid strategy to carry simultaneously antitumor drugs allowing their intravenous administration. In this study, liposomes loaded with glucoevatromonoside containing peracetylated glucose hydroxyl groups (GEVPG) and DOX at molar ratio of 1:1 (SpHL-GEVPG:DOX 1:1) were developed, and their chemical and physicochemical properties were evaluated. This formulation presented a combination index (CI) lower than 1 at inhibitory concentration of 90 % growth (IC₉₀) for three human breast tumor lines evaluated (0.52 ± 0.39 for MDA-MB-231, 0.19 ± 0.13 for MCF-7, and 0.99 ± 0.09 for SKBR-3). These results indicate a synergistic cytotoxic effect of the GEVPG and DOX combination encapsulated in liposomes. In addition, SpHL-GEVPG:DOX 1:1 presented selectivity towards these cancer cells. Long-term in vitro cytotoxicity studies demonstrated that MDA-MB-231 surviving cells after treatment with SpHL-GEVPG:DOX 1:1 did not recover proliferation capacity after 21 d. From the studies of cell cycle and death pathway evaluation, it was observed that SpHL-GEVPG:DOX 1:1 arrested the cell cycle in the G2/M phase and similarly induced apoptosis and necrosis. However, SpHL-GEVPG:DOX at molar ratio of 1:1 showed lower induction of both apoptotic and necrotic pathways compared to free DOX and SpHL-DOX, suggesting that the mechanism of death involved may not be related to necrosis or apoptosis. Lastly, SpHL-GEVPG:DOX 1:1 showed a good storage stability for 90 d at 4 °C. Therefore, the results of the present work indicate the potential use of SpHL-GEVPG:DOX 1:1 as a new anticancer formulation.

The Impact of [C16Pyr][Amp] on the Aggressiveness in Breast and Prostate Cancer Cell Lines

Breast (BrCa) and prostate (PCa) cancers are the most common malignancies in women and men, respectively. The available therapeutic options for these tumors are still not curative and have severe side effects. Therefore, there is an urgent need for more effective antineoplastic agents. Herein, BrCa, PCa, and benign cell lines were treated with two ionic liquids and two quinoxalines and functional experiments were performed-namely cell viability, apoptosis, cytotoxicity, and colony formation assays. At the molecular level, an array of gene expressions encompassing several molecular pathways were used to explore the impact of treatment on gene expression. Although both quinoxalines and the ionic liquid [C2OHMIM][Amp] did not show any effect on the BrCa and PCa cell lines, [C16Pyr][Amp] significantly decreased cell viability and colony formation ability, while it increased the apoptosis levels of all cell lines. Importantly, [C16Pyr][Amp] was found to be more selective for cancer cells and less toxic than cisplatin. At the molecular level, this ionic liquid was also associated with reduced expression levels of CPT2, LDHA, MCM2, and SKP2, in both BrCa and PCa cell lines. Hence, [C16Pyr][Amp] was shown to be a promising anticancer therapeutic agent for BrCa and PCa cell lines.

Identifying the Responses from the Estrogen Receptor-Expressed MCF7 Cells Treated in Anticancer Drugs of Different Modes of Action Using Live-Cell FTIR Spectroscopy

Recently, we have shown that changes in Fourier transform infrared (FTIR) spectra of living MDA-MB-231 cells (a triple negative cell line) upon exposure to anticancer drugs reflect the changes in the cellular compositions which are correlated to the modes of action of drugs. In the present study, MCF7 cells (an estrogen receptor expressing breast cancer cell line) were exposed to three anticancer drugs belonging to two well-characterized anticancer classes: selective estrogen receptor modulators (SERMs) and DNA-intercalating agent. First, we evaluated if the changes in the spectrum of cells are according to the modes of action of drugs and the characteristics of the MCF7 cell line in the same way as the MDA-MB-231 cell. Living MCF7 cells were treated in the three drugs at half maximal inhibitory concentration (IC50), and the difference spectra were analyzed using principal component analysis (PCA). The results demonstrated clear separation between tamoxifen/toremifene (SERM)-treated cells from the doxorubicin (DNA-intercalator)-treated and untreated cells (control). Tamoxifen and toremifene induced similar spectral changes in the cellular compositions of MCF7 cells and lead to the clustering of these two drugs in the same quadrant of the principal component 1 (PC1) versus PC2 score plots. The separation is mostly attributed to their similar modes of actions. However, doxorubicin-treated MCF7 cells highlighted spectral changes that mainly occur in bands at 1085 and 1200-1240 cm^-1, which could be associated with the DNA-intercalation effects of the drug. Second, the pairwise PCA at various individual time points was employed to investigate whether the spectral changes of MCF7 and MDA-MB-231 cells in response to the IC50 of tamoxifen/toremifene and doxorubicin are dependent on the characteristics of the cell lines. The estrogen-expressing MCF7 cells demonstrated significant differences in response to the SERMs in comparison to the triple negative MDA-MB-231 cells, suggesting that different modes of action have taken place in the two tested cell lines. In contrast, the doxorubicin-treated MDA-MB-231 and MCF7 cells show similar changes in 1150-950 cm^-1, which indicates that the DNA intercalation effect of doxorubicin is found in both cell lines. The results have demonstrated that live-cell FTIR analysis is sensitive to the different modes of action from the same drugs on cells with different characteristics.

Intranasal delivery of cancer-targeting doxorubicin-loaded PLGA nanoparticles arrests glioblastoma growth

Glioblastoma multiforme (GBM) is the most aggressive form of brain tumour and treatment is very challenging. Despite the recent advances in drug delivery systems, various approaches that allow sufficient deposition of anti-cancer drugs within the brain remain unsuccessful due to limited drug delivery throughout the brain. In this study, we utilised an intranasal (IN) approach to allow delivery of anti-cancer drug, encapsulated in PLGA nanoparticles (NPs). PLGA NPs were modified with the RGD ligand to enable A_vβ₃ expressing tumour-specific delivery. IN delivery of RGD-conjugated-doxorubicin (DOX)-loaded-PLGA-nanoparticles (RGD-DOX-NP) showed cancer-specific delivery of NP and inhibition of brain tumour growth compared to the free-DOX or non-modified DOX-NP in the C6-implanted GBM model. Further, IN treatment with RGD-DOX-NP induces apoptosis in the tumour region without affecting normal brain cells. Our study provides therapeutic evidence to treat GBM using a non-invasive IN approach, which may further be translated to other brain-associated diseases.

Small extracellular vesicles convey the stress-induced adaptive responses of melanoma cells

Exosomes are small extracellular vesicles (sEVs), playing a crucial role in the intercellular communication in physiological as well as pathological processes. Here, we aimed to study whether the melanoma-derived sEV-mediated communication could adapt to microenvironmental stresses. We compared B16F1 cell-derived sEVs released under normal and stress conditions, including cytostatic, heat and oxidative stress. The miRNome and proteome showed substantial differences across the sEV groups and bioinformatics analysis of the obtained data by the Ingenuity Pathway Analysis also revealed significant functional differences. The in silico predicted functional alterations of sEVs were validated by in vitro assays. For instance, melanoma-derived sEVs elicited by oxidative stress increased Ki-67 expression of mesenchymal stem cells (MSCs); cytostatic stress-resulted sEVs facilitated melanoma cell migration; all sEV groups supported microtissue generation of MSC-B16F1 co-cultures in a 3D tumour matrix model. Based on this study, we concluded that (i) molecular patterns of tumour-derived sEVs, dictated by the microenvironmental conditions, resulted in specific response patterns in the recipient cells; (ii) in silico analyses could be useful tools to predict different stress responses; (iii) alteration of the sEV-mediated communication of tumour cells might be a therapy-induced host response, with a potential influence on treatment efficacy.

N-(2-hydroxyphenyl) acetamide (NA-2) elicits potent antitumor effect against human breast cancer cell line (MCF-7)

Breast cancer is the most dominating malignancy in females worldwide. Treatment with conventional chemotherapeutics is associated with severe adverse effects. Thus need of new compounds, with better therapeutic potential and lesser side effects still exist. In this context the present study is planned to investigate therapeutic potential of anti-inflammatory compound N-(2- hydroxyphenyl) acetamide (NA-2) against breast cancer cells (MCF-7). The compound was selected on the basis of its reported anti-inflammatory, anti-arthritic and anti-glioblastoma activities in our previous studies. MTT, Annexin-V-FITC and wound healing assays were used to analyze the effect of compound on growth inhibition, apoptosis and metastasis. While flow cytometry, RT-PCR and immunocytochemistry techniques were used to assess the effect of NA-2 on cell cycle arrest, and expression of apoptotic markers (Bax and Bcl-2) at both mRNA and protein level respectively. Data analysis revealed that NA-2 significantly inhibits growth of MCF-7 cells after 48 h treatment (IC₅₀ = 1.65 mM). NA-2 also delayed the wound healing process, arrested cell cycle at G0/G1 phase and induced apoptosis by enhancing Bax/Bcl-2 ratio. We concluded that NA-2 possesses strong anticancer activity against MCF-7 cells, which is mediated through different mechanisms, making it a useful molecule for the development of new antitumor drugs.

Telomerase Inhibitor TMPyP4 Alters Adhesion and Migration of Breast-Cancer Cells MCF7 and MDA-MB-231

Human telomeres were one of the first discovered and characterized sequences forming quadruplex structures. Association of these structures with oncogenic and tumor suppressor proteins suggests their important role in cancer development and therapy efficacy. Since cationic porphyrin TMPyP4 is known as G-quadruplex stabilizer and telomerase inhibitor, the aim of the study was to analyze the anticancer properties of this compound in two different human breast-cancer MCF7 and MDA-MB-231 cell lines. The cytotoxicity of TMPyP4 alone or in combination with doxorubicin was measured by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromid) and clonogenic assays, and the cell-cycle alterations were analyzed by flow cytometry. Telomerase expression and activity were evaluated using qPCR and telomeric repeat amplification protocol (TRAP) assays, respectively. The contribution of G-quadruplex inhibitor to protein pathways engaged in cell survival, DNA repair, adhesion, and migration was performed using immunodetection. Scratch assay and functional assessment of migration and cell adhesion were also performed. Consequently, it was revealed that in the short term, TMPyP4 neither revealed cytotoxic effect nor sensitized MCF7 and MDA-MB-231 to doxorubicin, but altered breast-cancer cell adhesion and migration. It suggests that TMPyP4 might substantially contribute to a significant decrease in cancer cell dissemination and, consequently, cancer cell survival reduction. Importantly, this effect might not be associated with telomeres or telomerase.

Plug-and-Play Continuous Gas Flow Assembly of Cysteine-Inserted AuCu Nanobimetals for Folate-Receptor-Targeted Chemo-Phototherapy

Conjugatable nanobimetals exhibiting broadband light absorption for use as phototherapeutic platforms were assembled via a plug-and-play continuous gas flow route. Electrically produced AuCu nanobunches (NBs) under nitrogen gas flow were directly injected into cysteine (cys) solution through gas pressurization to mechanically spray the solution (AuCu into cys droplets). The sprayed droplets were then exposed to 185 nm UV light (higher photon energy [6.2 eV] than the work functions of Au [5.1 eV] and Cu [4.7 eV]) to initiate photoionization of AuCu NBs for subsequent electrostatic reaction with the SH^- group of cys to form cys-inserted AuCu (AuCu-cys) platforms in a single-pass gas stream. These platforms exhibited broadband light absorption spectra because of hybridized interparticle plasmonic coupling and could be conjugated to folic acid (FA) when dispersed in FA solution to form highly dispersible, biocompatible, and cancer-targetable AuCu-cys-FA. This material was suitable for use in targeted phototherapy of folate-receptor (FR)-rich cancers via FR-mediated endocytosis, and loading doxorubicin (DOX) into AuCu-cys-FA (i.e., AuCu-cys-DOXFA) facilitated chemo-phototherapy because of photoresponsive anticancer drug release upon induction of hyperthermia.

Induction of cell cycle arrest and inflammatory genes by combined treatment with epigenetic, differentiating, and chemotherapeutic agents in triple-negative breast cancer

Background

A combination of entinostat, all-trans retinoic acid, and doxorubicin (EAD) induces cell death and differentiation and causes significant regression of xenografts of triple-negative breast cancer (TNBC).

Methods

We investigated the mechanisms underlying the antitumor effects of each component of the EAD combination therapy by high-throughput gene expression profiling of drug-treated cells.

Results

Microarray analysis showed that entinostat and doxorubicin (ED) altered expression of genes related to growth arrest, inflammation, and differentiation. ED downregulated MYC, E2F, and G2M cell cycle genes. Accordingly, entinostat sensitized the cells to doxorubicin-induced growth arrest at G2. ED induced interferon genes, which correlated with breast tumors containing a higher proportion of tumor-infiltrating lymphocytes. ED also increased the expression of immune checkpoint agonists and cancer testis antigens. Analysis of TNBC xenografts showed that EAD enhanced the inflammation score in nude mice. Among the genes differentially regulated between the EAD and ED groups, an all-trans retinoic acid (ATRA)-regulated gene, DHRS3, was induced in EAD-treated xenografts. DHRS3 was expressed at lower levels in human TNBC metastases compared to normal breast or primary tumors. High expression of ED-induced growth arrest and inflammatory genes was associated with better prognosis in TNBC patients.

Conclusions

Entinostat potentiated doxorubicin-mediated cell death and the combination induced inflammatory signatures. The ED-induced immunomodulation may improve immunotherapy. Addition of ATRA to ED may potentiate inflammation and contribute to TNBC regression.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-1068-x) contains supplementary material, which is available to authorized users.

Doxorubicin induces an extensive transcriptional and metabolic rewiring in yeast cells

Doxorubicin is one of the most effective chemotherapy drugs used against solid tumors in the treatment of several cancer types. Two different mechanisms, (i) intercalation of doxorubicin into DNA and inhibition of topoisomerase II leading to changes in chromatin structure, (ii) generation of free radicals and oxidative damage to biomolecules, have been proposed to explain the mode of action of this drug in cancer cells. A genome-wide integrative systems biology approach used in the present study to investigate the long-term effect of doxorubicin in Saccharomyces cerevisiae cells indicated the up-regulation of genes involved in response to oxidative stress as well as in Rad53 checkpoint sensing and signaling pathway. Modular analysis of the active sub-network has also revealed the induction of the genes significantly associated with nucleosome assembly/disassembly and DNA repair in response to doxorubicin. Furthermore, an extensive re-wiring of the metabolism was observed. In addition to glycolysis, and sulfate assimilation, several pathways related to ribosome biogenesis/translation, amino acid biosynthesis, nucleotide biosynthesis, de novo IMP biosynthesis and one-carbon metabolism were significantly repressed. Pentose phosphate pathway, MAPK signaling pathway biological processes associated with meiosis and sporulation were found to be induced in response to long-term exposure to doxorubicin in yeast cells.

Prosopis juliflora (Sw.), DC induces apoptosis and cell cycle arrest in triple negative breast cancer cells: in vitro and in vivo investigations

Plant originated drugs/formulations are extensively prescribed by the physicians as a complementary therapy for treating various human ailments including cancer. In this study Prosopis juliflora leaves methanol extract was prepared and exposed to human breast cancer cell lines i.e. MDA-MB-231 and MCF-7 and human keratinocytes HaCaT as a representative of normal cells. Initially, a series of in vitro experiments like cell proliferation, migration, colony formation, cell cycle arrest and inhibition of angiogenesis. After confirmation of the efficient and selective activity against triple negative breast cancer cell line, we further evaluated the possible mechanism of inducing cell death and experiments like detection of reactive oxygen species, caspases and poly (ADP-ribose) polymerase cleavage study and Annexin V assay were performed. We also evaluated in vivo anti tumorigenic activity of the P. juliflora leaves by using 4T1 cells (a triple negative mouse origin breast cancer cell line) and BALB/c xenograft mouse model. In vitro experiments revealed that methanol extract of Prosopis juliflora leaves possess impressive anti-breast cancer activity more specifically against triple negative breast cancer cells, while the in vivo studies demonstrated that P. juliflora leaves extract significantly suppressed the 4T1 induced tumor growth. Present investigations clearly focus the significance of P. juliflora as an important resource for finding novel leads against triple negative breast cancer. The results may also act as a ready reference towards developing P. juliflora based formulation as an alternative and complementary medicine for the management of breast cancer.

Schedule dependent synergy of gemcitabine and doxorubicin: Improvement of in vitro efficacy and lack of in vitro-in vivo correlation

Combination chemotherapy is commonly used to treat late stage cancer; however, treatment is often limited by systemic toxicity. Optimizing drug ratio and schedule can improve drug combination activity and reduce dose to lower toxicity. Here, we identify gemcitabine (GEM) and doxorubicin (DOX) as a synergistic drug pair in vitro for the triple negative breast cancer cell line MDA‐MB‐231. Drug synergy and caspase activity were increased the most by exposing cells to GEM prior to DOX in vitro. While the combination was more effective than the single drugs at inhibiting MDA‐MB‐231 growth in vivo, the clear schedule dependence observed in vitro was not observed in vivo. Differences in drug exposure and cellular behavior in vivo compared to in vitro are likely responsible. This study emphasizes the importance in understanding how schedule impacts drug synergy and the need to develop more advanced strategies to translate synergy to the clinic.

A hyaluronic acid conjugate engineered to synergistically and sequentially deliver gemcitabine and doxorubicin to treat triple negative breast cancer

Combination chemotherapy is commonly used to treat advanced breast cancer. However, treatment success is often limited due to systemic toxicity. To improve therapeutic efficacy, polymer drug conjugates carrying synergistic pairs of chemotherapy drugs can be used to reduce drug administration dose. Here, we systematically evaluated the effect of temporal scheduling of doxorubicin (DOX) and gemcitabine (GEM) on drug synergy. Hyaluronic acid (HA) drug conjugates with distinct linkers conjugating both DOX and GEM were synthesized to control relative release kinetics of each drug. We show that polymer conjugates that release GEM faster than DOX are more effective at killing triple negative breast cancer cells in vitro. We further show that the optimal dual drug conjugate more effectively inhibits the growth of an aggressive, orthotopic 4T1 tumor model in vivo than free DOX and GEM and the single drug HA conjugates. The dual drug HA conjugate can inhibit 4T1 tumor growth in vivo during treatment through both intravenous and non-local subcutaneous injections. These results emphasize the importance of understanding the effect release rates have on the efficacy of synergistic drug carriers and motivate the use of HA as a delivery platform for multiple cancer types.

A Critical Review on the Effect of Docosahexaenoic Acid (DHA) on Cancer Cell Cycle Progression

Globally, there were 14.1 million new cancer diagnoses and 8.2 million cancer deaths in 2012. For many cancers, conventional therapies are limited in their successes and an improved understanding of disease progression is needed in conjunction with exploration of alternative therapies. The long chain polyunsaturated fatty acid, docosahexaenoic acid (DHA), has been shown to enhance many cellular responses that reduce cancer cell viability and decrease proliferation both in vitro and in vivo. A small number of studies suggest that DHA improves chemotherapy outcomes in cancer patients. It is readily incorporated into cancer cell membranes and, as a result there has been considerable research regarding cell membrane initiated events. For example, DHA has been shown to mediate the induction of apoptosis/reduction of proliferation in vitro and in vivo. However, there is limited research into the effect of DHA on cell cycle regulation in cancer cells and the mechanism(s) by which DHA acts are not fully understood. The purpose of the current review is to provide a critical examination of the literature investigating the ability of DHA to stall progression during different cell cycle phases in cancer cells, as well as the consequences that these changes may have on tumour growth, independently and in conjunction with chemotherapy.

Induction of accelerated senescence by the microtubule-stabilizing agent peloruside A

Chemotherapeutic agents can induce accelerated senescence in tumor cells, an irreversible state of cell cycle arrest. Paclitaxel, a microtubule-stabilizing agent used to treat solid tumors of the breast, ovary, and lung and discodermolide, another stabilizing agent from a marine sponge, induce senescence in cultured cancer cells. The aim of this study was to determine if the microtubule-stabilizing agent peloruside A, a polyketide natural product from a marine sponge, can induce accelerated senescence in a breast cancer cell line MCF7. Doxorubicin, a DNA-damaging agent, paclitaxel, and discodermolide were used as positive controls. Senescence-associated-β-galactosidase activity was increased by peloruside A, similar to paclitaxel, discodermolde, and doxorubicin, with a potency heirarchy of doxorubicin > paclitaxel > discodermolide > peloruside, based on IC₂₅ concentrations that inhibit proliferation. Clonogenic survival was significantly decreased by peloruside A, similar to doxorubicin and the two other microtubule-stabilizing agents. The tumor suppressor protein p53 increased after treatment, whereas pRb decreased in response to all four compounds. It was concluded that in addition to apoptosis, peloruside A causes accelerated senescence in a subpopulation of MCF7 cells that contributes to its potential anticancer activity in a breast cancer cell line.

Original research paper. Hydrazinyldiene-chroman-2,4-diones in inducing growth arrest and apoptosis in breast cancer cells: Synergism with doxorubicin and correlation with physicochemical properties

This study evaluates the effects of previously synthesized hydrazinyldiene-chroman-2,4-diones on cell proliferation and apoptosis, cell cycle distribution and migration capacity of MCF-7 breast cancer cells in synergy with doxorubicin. Physicochemical properties of the synthesized compounds were correlated with their structure and activity. Significant cell viability decrease in comparison with the effect of doxorubicin alone and the reference 4-hydroxycoumarin was observed when combination treatment comprising doxorubicin and the title compounds was applied. Synergistic effect with doxorubicin was also observed in down-regulation of phospho-Thr308Akt levels, confirming reduced proliferation and increased apoptosis. Combined treatment increased the percentage of cells arrested at the G2/M stage. Additive inhibition of cell migration was also observed, pointing to the possibility of reducing the risk of metastases. With their solubility profile and log D7.4, all the synthesized compounds follow Lipinski's rule of five for good permeability (absorption) potential.

Dual-Targeting Magnetic PLGA Nanoparticles for Codelivery of Paclitaxel and Curcumin for Brain Tumor Therapy

Chemotherapy is one of the most important strategies for glioma treatment. However, the "impermeability" of the blood-brain barrier (BBB) impedes most chemotherapeutics from entering the brain, thereby rendering very few drugs suitable for glioma therapy, letting alone application of a combination of chemotherapeutics. Thereby, there is a pressing need to overcome the obstacles. A dual-targeting strategy was developed by a combination of magnetic guidance and transferrin receptor-binding peptide T7-mediated active targeting delivery. The T7-modified magnetic PLGA nanoparticle (NP) system was prepared with co-encapsulation of the hydrophobic magnetic nanoparticles and a combination of drugs (i.e., paclitaxel and curcumin) based on a "one-pot" process. The combined drugs yielded synergistic effects on inhibition of tumor growth via the mechanisms of apoptosis induction and cell cycle arrest, displaying significantly increased efficacy relative to the single use of each drug. Dual-targeting effects yielded a >10-fold increase in cellular uptake studies and a >5-fold enhancement in brain delivery compared to the nontargeting NPs. For the in vivo studies with an orthotopic glioma model, efficient brain accumulation was observed by using fluorescence imaging, synchrotron radiation X-ray imaging, and MRI. Furthermore, the antiglioma treatment efficacy of the delivery system was evaluated. With application of a magnetic field, this system exhibited enhanced treatment efficiency and reduced adverse effects. All mice bearing orthotopic glioma survived, compared to a 62.5% survival rate for the combination group receiving free drugs. This dual-targeting, co-delivery strategy provides a potential method for improving brain drug delivery and antiglioma treatment efficacy.

Design of dual stimuli responsive polymer modified magnetic nanoparticles for targeted anti-cancer drug delivery and enhanced MR imaging

Stimuli triggered release of DOX from dual responsive theranostic nanocarriers mimicking lysosomal conditions i.e. physiological temperature (37 °C) and acidic pH (5.5).

Evaluation of antioxidant and anticancer activity of extract and fractions of Nardostachys jatamansi DC in breast carcinoma

Background

Nardostachys jatamansi DC is a Himalayan medicinal herb that has been described in various traditional systems of medicine for its use in cancer. In view of its traditional claims, and chemical constituents, antioxidant and anticancer activities were evaluated in breast carcinoma.

Methods

Petroleum ether (NJPE), methanol extract (NJM) and subsequent diethyl ether (NJDE), ethyl acetate (NJEA) and aqueous (NJAQ) fractions of roots and rhizomes of N. jatamansi were prepared. Total phenolic, flavonoid content, and antioxidant activities were determined using suitable methods. Antiproliferative activity was assessed in estrogen receptor (ER)-positive (MCF-7) and ER-negative breast carcinoma (MDA-MB-231) cells by MTT and SRB assay. Cell cycle analysis, Hoechst staining, and clonogenic assay were employed to determine the mode of antiproliferative and pro-apoptotic activity in MDA-MB-231 cells.

Results

NJM/fractions exhibited prominent antioxidant activity with significant correlation between phenolic content and ABTS (IC₅₀) scavenging (R = −0.9680, P < 0.05), and total antioxidant capacity (R = 0.8396, P > 0.05). In MTT assay, NJM exhibited the highest antiproliferative activity (IC₅₀: 58.01 ± 6.13 and 23.83 ± 0.69 μg/mL in MCF-7 and MDA-MB-231 respectively). Among the fractions, NJPE and NJDE were found to be most potent in MCF-7 (IC₅₀: 60.59 ± 4.78 μg/mL) and MDA-MB-231 (IC₅₀: 25.04 ± 0.90 μg/mL) cells respectively. Statistical analyses revealed NJM and NJDE exhibited significantly higher (P < 0.05) cytotoxicity in MDA-MB-231 cells. Cell cycle analysis demonstrated that NJM, NJPE and NJEA caused G₂/M arrest while NJDE caused G₀/G₁ phase arrest in MDA-MB-231 cells. Further, NJM/fractions induced significant (P < 0.001) cell death by apoptosis characterized by apoptotic morphological changes in Hoechst staining and inhibited long-term proliferation (P < 0.001) of MDA-MB-231 cells in clonogenic assay. Lupeol and β-sitosterol were identified as anticancer principles in NJM/fractions by HPTLC.

Conclusion

Our results suggest that NJM/fractions possess significant antiproliferative potential which is mediated through cell cycle perturbation and pro-apoptotic effects in MDA-MB-231 cells. Moreover, this study highlights the antioxidant potential of NJM/fractions which can be attributed to the presence of phenols. NJDE emerged as the most potent fraction and further mechanistic and phytochemical investigations are under way to identify the active principles.

Cytotoxicity of Eupatorium cannabinum L. ethanolic extract against colon cancer cells and interactions with Bisphenol A and Doxorubicin

Background

Eupatorium cannabinum L. has long been utilized in traditional medicine, however no information is available regarding cellular effects of full extracts. Here we assessed the effects of E. cannabinum ethanolic extract (EcEE) on the colon cancer line HT29. Potential interactions with bisphenol A (BPA) a synthetic phenolic compound to which humans are generally exposed and a commonly used chemotherapeutic agent, doxorubicin (DOX) were also evaluated.

Methods

HT29 cells were exposed to different concentrations (0.5 to 50 μg/ml) of EcEE alone or in combination with BPA or DOX. Cell viability was analyzed through resazurin assay. Gene transcription levels for NCL, FOS, p21, AURKA and bcl-xl were determined through qRT-PCR. Cytological analysis included evaluation of nuclear and mitotic anomalies after DAPI staining, immunodetection of histone H3 lysine 9 acetylation (H3K9ac) and assessment of DNA damage by TUNEL assay.

Results

Severe loss of HT29 cell viability was detected for 50 μg/ml EcEE immediately after 24 h exposure whereas the lower concentrations assayed (0.5, 5 and 25 μg/ml) resulted in significant viability decreases after 96 h. Exposure to 25 μg/ml EcEE for 48 h resulted in irreversible cell damage leading to a drastic decrease in cell viability after 72 h recovery in EcEE-free medium. 48 h 25 μg/ml EcEE treatment also induced alteration of colony morphology, H3K9 hyperacetylation, transcriptional up regulation of p21 and down regulation of NCL, FOS and AURKA, indicating reduced proliferation capacity. This treatment also resulted in drastic mitotic and nuclear disruption accompanied by up-regulation of bcl-xl, limited TUNEL labeling and nuclear size increase, suggestive of a non-apoptocic cell death pathway. EcEE/BPA co-exposure increased mitotic anomalies particularly for the lowest EcEE concentration, although without major effects on viability. Conversely, EcEE/DOX co-exposure decreased cell viability in relation to DOX for all EcEE concentrations, without affecting the DOX-induced cell cycle arrest.

Conclusions

EcEE has cytotoxic activity on HT29 cancer cells leading to mitotic disruption and non-apoptotic cell death without severe induction of DNA damage. Interaction experiments showed that EcEE can increase BPA aneugenic effects and EcEE synergistic effects with DOX supporting a potential use as adjuvant in chemotherapeutic approaches.

CDK4 inhibition and doxorubicin mediate breast cancer cell apoptosis through Smad3 and survivin

Cyclin D1/CDK4 activity is upregulated in up to 50% of breast cancers and CDK4-mediated phosphorylation negatively regulates the TGFβ superfamily member Smad3. We sought to determine if CDK4 inhibition and doxorubicin chemotherapy could impact Smad3-mediated cell/colony growth and apoptosis in breast cancer cells. Parental and cyclin D1-overexpressing MCF7 cells were treated with CDK4 inhibitor, doxorubicin, or combination therapy and cell proliferation, apoptosis, colony formation, and expression of apoptotic proteins were evaluated using an MTS assay, TUNEL staining, 3D Matrigel assay, and apoptosis array/immunoblotting. Study cells were also transduced with WT Smad3 or a Smad3 construct resistant to CDK4 phosphorylation (5M) and colony formation and expression of apoptotic proteins were assessed. Treatment with CDK4 inhibitor/doxorubicin combination therapy, or transduction with 5M Smad3, resulted in a similar decrease in colony formation. Treating cyclin D overexpressing breast cancer cells with combination therapy also resulted in the greatest increase in apoptosis, resulted in decreased expression of anti-apoptotic proteins survivin and XIAP, and impacted subcellular localization of pro-apoptotic Smac/DIABLO. Additionally, transduction of 5M Smad3 and doxorubicin treatment resulted in the greatest change in apoptotic protein expression. Collectively, this work showed the impact of CDK4 inhibitor-mediated, Smad3-regulated tumor suppression, which was augmented in doxorubicin-treated cyclin D-overexpressing study cells.

3-Bromo-1-hydroxy-9,10-anthraquinone (BHAQ) inhibits growth and migration of the human breast cancer cell lines MCF-7 and MDA-MB231

Breast cancer is becoming more prominent in women today. As of now, there are no effective treatments in treating metastatic breast cancer. We have tested the cytotoxic and anti-migration effects of BHAQ, a synthesized anthraquinone, on two breast cancer cell lines, MCF-7 and MDA-MB231. Anthraquinones are an interesting class of molecules that display a wide spectrum of biological applications, including anticancer properties. Cellular inhibition was tested through a MTT assay, double acridine orange/propidium iodide staining and FACS cell cycle analysis. Inhibition of migration was tested by the wound healing method, and migration through a Boyden chamber. BHAQ was cytotoxic towards both cell lines in a dose dependent and possibly cell-dependent manner. Additionally, BHAQ also inhibited the migration of the highly metastatic MDA-MB231 cell line.