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1.
Mol Pharm ; 15(7): 2698-2713, 2018 07 02.
Article in English | MEDLINE | ID: mdl-29787277

ABSTRACT

Tamoxifen administration enhanced overall disease-free survival and diminished mortality rates in cancer patients. However, patients with breast cancer often fail to respond for tamoxifen therapy due to the development of a drug-resistant phenotype. Functional analysis and molecular studies suggest that protein mutation and dysregulation of survival signaling molecules such as epidermal growth factor receptor, vascular endothelial growth factor receptor 2, and Akt contribute to tamoxifen resistance. Various strategies, including combinatorial therapies, show chemosensitize tamoxifen-resistant cancers. Based on chemotoxicity issues, researchers are actively investigating alternative therapeutic strategies. In the current study, we fabricate a mesoporous silica gold cluster nanodrug delivery system that displays exceptional tumor-targeting capability, thus promoting accretion of drug indices at the tumor site. We employ dual drugs, ZD6474, and epigallocatechin gallate (EGCG) that inhibit EGFR2, VEGFR2, and Akt signaling pathways since changes in these signaling pathways confer tamoxifen resistance in MCF 7 and T-47D cells. Mesoporous silica gold cluster nanodrug delivery of ZD6474 and EGCG sensitize tamoxifen-resistant cells to apoptosis. Western and immune-histochemical analyses confirmed the apoptotic inducing properties of the nanoformulation. Overall, results with these silica gold nanoclusters suggest that they may be a potent nanoformulation against chemoresistant cancers.


Subject(s)
Antineoplastic Agents/pharmacology , Breast Neoplasms/drug therapy , Drug Carriers/chemistry , Drug Resistance, Neoplasm/drug effects , Animals , Antineoplastic Agents/therapeutic use , Apoptosis/drug effects , Breast Neoplasms/pathology , Catechin/analogs & derivatives , Catechin/pharmacology , Catechin/therapeutic use , Cell Line, Tumor , Cell Proliferation/drug effects , Chemical Engineering , ErbB Receptors/metabolism , Female , Gold/chemistry , Humans , Metal Nanoparticles/chemistry , Mice, Nude , Piperidines/pharmacology , Piperidines/therapeutic use , Porosity , Proto-Oncogene Proteins c-akt/metabolism , Quinazolines/pharmacology , Quinazolines/therapeutic use , Silicon Dioxide/chemistry , Tamoxifen/pharmacology , Tamoxifen/therapeutic use , Treatment Outcome , Vascular Endothelial Growth Factor Receptor-2/metabolism , Xenograft Model Antitumor Assays
2.
Oncogene ; 37(33): 4546-4561, 2018 08.
Article in English | MEDLINE | ID: mdl-29743594

ABSTRACT

Although there is a strong correlation between multinucleated cells (MNCs) and cancer chemo-resistance in variety of cancers, our understanding of how multinucleated cells modulate the tumor micro-environment is limited. We captured multinucleated cells from triple-negative chemo-resistant breast cancers cells in a time frame, where they do not proliferate but rather significantly regulate their micro-environment. We show that oxidatively stressed MNCs induce chemo-resistance in vitro and in vivo by secreting VEGF and MIF. These factors act through the RAS/MAPK pathway to induce chemo-resistance by upregulating anti-apoptotic proteins. In MNCs, elevated reactive oxygen species (ROS) stabilizes HIF-1α contributing to increase production of VEGF and MIF. Together the data indicate, that the ROS-HIF-1α signaling axis is very crucial in regulation of chemo-resistance by MNCs. Targeting ROS-HIF-1α in future may help to abrogate drug resistance in breast cancer.


Subject(s)
Drug Resistance, Neoplasm/physiology , Reactive Oxygen Species/metabolism , Triple Negative Breast Neoplasms/metabolism , Breast/metabolism , Cell Line, Tumor , Female , Humans , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Macrophage Migration-Inhibitory Factors/metabolism , Signal Transduction/physiology , Tumor Microenvironment/physiology , Vascular Endothelial Growth Factor A/metabolism
3.
Langmuir ; 33(31): 7649-7659, 2017 08 08.
Article in English | MEDLINE | ID: mdl-28701038

ABSTRACT

The therapeutic index of poorly water-soluble drugs is often hampered due to poor pharmacokinetics, reduced blood retention, and lack of effective drug concentrations in the tumor region. In order to overcome these issues, drugs are often delivered by use of delivery vehicles to provide an enhanced therapeutic index. Gold nanoparticles synthesized in micellar networks of amphiphilic block copolymer (AuNM) provide an efficient nanocarrier for tissue- and site-specific drug delivery owing to their low cytotoxicity and immunogenicity. AuNM is formed by exploiting the properties of both inorganic Au material and an amphiphilic polymer of poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEG-PPG-PEG). We further functionalized AuNM with the FDA-approved dual tyrosine kinase inhibitor ZD6474 and studied the physicochemical properties of the conjugate ZD6474-AuNM. Both AuNM and ZD6474-AuNM, with a diameter of ∼70 nm, were very stable at physiological pH. Conversely, at an acidic pH of 5.2, a slow sustained-release profile of ZD6474 was evident from AuNM, which could provide a method of facilitating release of the drug in an acidic tumor environment. In vitro, in triple-negative breast cancer cells, ZD6474-AuNM inhibited tumor cell proliferation, migration, and invasion and induced apoptosis. There was no detectable lysis of red blood cells observed when they were treated with AuNM and ZD6474-AuNM, confirming hemocompatibility. To reinforce the possibility of AuNM serving as a delivery vehicle, AuNM was conjugated with the IR680 dye for tracking, and this conjugate was systemically delivered in female nude mice bearing MDA-MB-231 human breast cancer xenografts. Fluorescence signal was retained in the tumor region in a temporal manner as compared to other organs, indicating passive retention of AuNM in the tumor locale. Moreover, delivery of ZD6474-AuNM in nude mice bearing MDA-MB-231 xenografts led to decreased tumor size as compared to the control group. The promising safety, targeting, and therapeutic results of systemic delivery of ZD6474 by AuNM provide an attractive alternative method for treating patients with metastatic breast cancer.


Subject(s)
Metal Nanoparticles , Animals , Breast Neoplasms , Cell Line, Tumor , Female , Gold , Humans , Mice , Mice, Nude , Micelles , Piperidines , Polyethylene Glycols , Protein Kinase Inhibitors , Protein-Tyrosine Kinases , Quinazolines
4.
Mol Pharm ; 12(12): 4214-25, 2015 Dec 07.
Article in English | MEDLINE | ID: mdl-26505213

ABSTRACT

Akt overexpression in cancer causes resistance to traditional chemotherapeutics. Silencing Akt through siRNA provides new therapeutic options; however, poor in vivo siRNA pharmacokinetics impede translation. We demonstrate that acidic milieu-sensitive multilamellar gold niosomes (Nio-Au) permit targeted delivery of both Akt-siRNA and thymoquinone (TQ) in tamoxifen-resistant and Akt-overexpressing MCF7 breast cancer cells. Octadecylamine groups of functionalized gold nanoparticles impart cationic attribute to niosomes, stabilized through polyethylene glycol. TQ's aqueous insolubility renders its encapsulation within hydrophobic core, and negatively charged siRNA binds in hydrophilic region of cationic niosomes. These niosomes were exploited to effectively knockdown Akt, thereby sensitizing cells to TQ. Immunoblot studies revealed enhanced apoptosis by inducing p53 and inhibiting MDM2 expression, which was consistent with in vivo xenograft studies. This innovative strategy, using Nio-Au to simultaneously deliver siRNA (devoid of any chemical modification) and therapeutic drug, provides an efficacious approach for treating therapy-resistant cancers with significant translational potential.


Subject(s)
Benzoquinones/pharmacology , Breast Neoplasms/drug therapy , Drug Resistance, Neoplasm/drug effects , Gold/administration & dosage , Nanoparticles/administration & dosage , Proto-Oncogene Proteins c-akt/metabolism , RNA, Small Interfering/genetics , Apoptosis/drug effects , Breast Neoplasms/genetics , Cell Line, Tumor , Female , Humans , MCF-7 Cells , Tamoxifen/pharmacology
5.
Biomed Pharmacother ; 74: 124-32, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26349973

ABSTRACT

Tamoxifen resistance is a multifaceted phenomenon, characterized by the constitutive activation of multiple signaling cascades that provide an additional survival advantage to cells. Ground studies related to reverse the tamoxifen resistance by employing chemotherapeutic drugs that specifically inhibit proteins, those of aberrantly expressed, are required. Seminal studies showed that p38 signaling and VEGF play crucial role in acquiring resistance to tamoxifen. In this view, we had chosen paclitaxel, a mitotic inhibitor with anti-proliferative effects against a wide array of cancers in this study. Further to mitigate the undesirable complications of paclitaxel (PAC), we employed this drug in combination along with BI2536 (BI), a PLK inhibitor for this study to sensitize the tamoxifen resistant cells to apoptosis. MCF 7/TAM and T-47D/TAM cells were treated with PAC, BI and in combination (BI-PAC) evaluated for its anticancer activity through apoptotic and western blot analysis. Modulatory effects of BI-PAC on p38 inactivation were affirmed through immunofluorescence and drug potential studies. Results reveal that cells were subjected to apoptosis on drug(s) treatment which was confirmed through cytotoxicity, annexin studies. Further, the anti-proliferative effects of the drug(s) were affirmed through nuclear morphological and TUNEL assays. Immunoblot results revealed the upregulation of proapoptotic Bax, cleaved caspase 9 along with Bcl-2, MDM2, Cox-2, and P-Gly down regulation after 24h drug treatments. Moreover, phospho studies further construed the rationale behind the apoptosis and deduced the inactivation of p38 and NF-κB role in inducing apoptosis in drug treated cells. The efficacy of drug combinations in inactivating p38 was evaluated through drug potential studies. Further, BI-PAC treatments showed inhibition of p38 mediated senescence in tamoxifen resistant cells. Overall, our observations provide a new therapeutic combination that sensitizes tamoxifen resistant cells to apoptosis by specifically targeting p38 signaling and its downstream molecules and subsequently reduces extracellular VEGF levels.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Apoptosis/drug effects , Breast Neoplasms/drug therapy , Drug Resistance, Neoplasm/drug effects , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Breast Neoplasms/pathology , Cell Line, Tumor , Cellular Senescence/drug effects , Down-Regulation/drug effects , Female , Humans , In Situ Nick-End Labeling , NF-kappa B/metabolism , Paclitaxel/administration & dosage , Pteridines/administration & dosage , Signal Transduction/drug effects , Tamoxifen/administration & dosage , Up-Regulation/drug effects , Vascular Endothelial Growth Factor A/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism
6.
Sci Rep ; 5: 11760, 2015 Jul 06.
Article in English | MEDLINE | ID: mdl-26145450

ABSTRACT

Low pH in the tumor micromilieu is a recognized pathological feature of cancer. This attribute of cancerous cells has been targeted herein for the controlled release of chemotherapeutics at the tumour site, while sparing healthy tissues. To this end, pH-sensitive, hollow ZnO-nanocarriers loaded with paclitaxel were synthesized and their efficacy studied in breast cancer in vitro and in vivo. The nanocarriers were surface functionalized with folate using click-chemistry to improve targeted uptake by the malignant cells that over-express folate-receptors. The nanocarriers released ~75% of the paclitaxel payload within six hours in acidic pH, which was accompanied by switching of fluorescence from blue to green and a 10-fold increase in the fluorescence intensity. The fluorescence-switching phenomenon is due to structural collapse of the nanocarriers in the endolysosome. Energy dispersion X-ray mapping and whole animal fluorescent imaging studies were carried out to show that combined pH and folate-receptor targeting reduces off-target accumulation of the nanocarriers. Further, a dual cell-specific and pH-sensitive nanocarrier greatly improved the efficacy of paclitaxel to regress subcutaneous tumors in vivo. These nanocarriers could improve chemotherapy tolerance and increase anti-tumor efficacy, while also providing a novel diagnostic read-out through fluorescent switching that is proportional to drug release in malignant tissues.


Subject(s)
Antineoplastic Agents, Phytogenic/chemistry , Drug Carriers/chemistry , Metal Nanoparticles/chemistry , Paclitaxel/chemistry , Zinc Oxide/chemistry , Animals , Antineoplastic Agents, Phytogenic/administration & dosage , Antineoplastic Agents, Phytogenic/toxicity , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Survival/drug effects , Disease Progression , Female , Humans , Hydrogen-Ion Concentration , Metal Nanoparticles/ultrastructure , Mice , Mice, Inbred BALB C , Mice, Nude , Microscopy, Fluorescence , Paclitaxel/administration & dosage , Paclitaxel/toxicity , Transplantation, Heterologous
7.
Tumour Biol ; 36(12): 9829-37, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26159854

ABSTRACT

Despite the recent advances in diagnostic and therapeutic strategies, oral squamous cell carcinoma (OSCC) remains a major health burden. Protein biomarker discovery for early detection will help to improve patient survival rate in OSCC. Mass spectrometry-based proteomics has emerged as an excellent approach for detection of protein biomarkers in various types of cancers. In the current study, we have used 4-Plex isobaric tags for relative and absolute quantitation (iTRAQ)-based shotgun quantitative proteomic approach to identify proteins that are differentially expressed in cancerous tissues compared to normal tissues. The high-resolution mass spectrometric analysis resulted in identifying 2,074 proteins, among which 288 proteins were differentially expressed. Further, it was noticed that 162 proteins were upregulated, while 125 proteins were downregulated in OSCC-derived cancer tissue samples as compared to the adjacent normal tissues. We identified some of the known molecules which were reported earlier in OSCC such as MMP-9 (8.4-fold), ZNF142 (5.6-fold), and S100A7 (3.5-fold). Apart from this, we have also identified some novel signature proteins which have not been reported earlier in OSCC including ras-related protein Rab-2A isoform, RAB2A (4.6-fold), and peroxiredoxin-1, PRDX1 (2.2-fold). The immunohistochemistry-based validation using tissue microarray slides in OSCC revealed overexpression of the RAB2A and PRDX1 gene in 80 and 68 % of the tested clinical cases, respectively. This study will not only serve as a resource of candidate biomarkers but will contribute towards the existing knowledge on the role of the candidate molecules towards disease progression and therapeutic potential.


Subject(s)
Biomarkers, Tumor/biosynthesis , Carcinoma, Squamous Cell/genetics , Mouth Neoplasms/genetics , Peroxiredoxins/biosynthesis , rab GTP-Binding Proteins/biosynthesis , Aged , Biomarkers, Tumor/genetics , Carcinoma, Squamous Cell/pathology , Female , Gene Expression Regulation, Neoplastic , Humans , Male , Middle Aged , Mouth Neoplasms/pathology , Peroxiredoxins/genetics , Proteome/genetics , Proteomics , Tandem Mass Spectrometry , rab GTP-Binding Proteins/genetics
8.
J Mater Chem B ; 3(1): 90-101, 2015 Jan 07.
Article in English | MEDLINE | ID: mdl-32261929

ABSTRACT

Single drug therapies for cancer are often suboptimal and may not provide long term clinical benefits. To overcome this obstacle for effective treatment the applications of two or more drugs are preferable. A limitation of multidrug use is the varying pharmacokinetics of different drugs. To overcome these impediments, we designed and synthesized multi-layered polyvinyl alcohol tethered hollow manganese ferrite nanocarriers capable of encapsulating two drugs with unique attributes of sensitivity towards tumor acidic milieu, mono-dispersive, compactness and high encapsulation efficiency. We encapsulated tamoxifen and diosgenin in the peripheral and subsequent inner layers of multilayered nanocarriers. In vitro and in vivo studies evaluated the nanocarrier uptake and retention ability of the tumor through magnetic saturation studies and elucidated the molecular mechanisms mediating drug(s)-induced apoptosis. The acidity of the tumor environment triggers extracellular dissociation of the peripheral coats resulting in release of tamoxifen blocking the estrogen receptor. The partially degraded nanocarriers localize intracellularly through endosomal escape and release diosgenin. Nanocarrier treatment reduced the cellular levels of Bcl2 and p53, while increasing the levels of Bim. This delivery system successfully embodies the sequential release of drugs and may provide a therapeutic strategy for sequentially affecting multiple targets in advanced cancers.

9.
J Cell Physiol ; 230(3): 620-9, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25164250

ABSTRACT

Radiotherapy remains a prime approach to adjuvant therapies in patients with early and advanced breast cancer. In spite of therapeutic success, metastatic progression in patients undergoing therapy, limits its application. However, effective therapeutic strategies to understand the cellular and molecular machinery in inhibiting radiation-induced metastatic progression, which is poorly understood so far, need to be strengthened. Ionizing radiation was known to prompt cancer cell's metastatic ability by eliciting Transforming Growth Factor-beta (TGF-ß), a key regulator in epithelial-mesenchymal transdifferentiation and radio-resistance. In this viewpoint, we employed thymoquinone as a radiosensitizer to investigate its migration and invasion reversal abilities in irradiated breast cancer cell lines by assessing their respective attributes. The role of metastasis regulatory molecules like TGF-ß, E-cadherin, and integrin αV and its downstream molecules were determined using RT-PCR, western blotting, immunofluorescence, and extracellular TGF-ß levels affirmed through ELISA assays. These studies affirmed the TGF-ß restoring ability of thymoquinone in radiation-driven migration and invasion. Also, results demonstrated that the epithelial markers E-cadherin and cytokeratin 19 were downregulated whereas mesenchymal markers like integrin αV, MMP9, and MMP2 were upregulated by irradiation treatment; however thymoquinone pre-sensitization has reverted the expression of these proteins back to control proteins expression. Here, paclitaxel was chosen as an apoptosis inducer in TGF-ß restored cells and confirmed its cytotoxic effects in radiation alone and thymoquinone sensitized irradiated cells. We conclude that this therapeutic modality is effective in preventing radiation-induced epithelial-mesenchymal transdifferentiation and concomitant induction of apoptosis in breast cancer.


Subject(s)
Benzoquinones/administration & dosage , Breast Neoplasms/drug therapy , Epithelial-Mesenchymal Transition/drug effects , Transforming Growth Factor beta/biosynthesis , Apoptosis/drug effects , Breast Neoplasms/pathology , Breast Neoplasms/radiotherapy , Cell Line, Tumor , Cell Transdifferentiation/drug effects , Female , Humans , Paclitaxel/administration & dosage , Radiation , Radiotherapy/adverse effects
10.
Biosens Bioelectron ; 55: 44-50, 2014 May 15.
Article in English | MEDLINE | ID: mdl-24361421

ABSTRACT

The present work reports the impedance characteristics of MCF-7 cell lines treated with anticancer drug ZD6474 to evaluate the cytotoxic effect on cellular electrical behaviour using miniature impedance sensors. Four types of impedance sensing devices with different electrode geometries are fabricated by microfabrication technology. The frequency response characteristics of drug treated cells are studied to evaluate cytotoxic effect of ZD6474 and also to assess the frequency dependent sensitivity variation with electrode area. A significant variation in magnitude of measured impedance data is obtained for drug treated samples above 10 µM dose indicating prominent effect of ZD6474 which results in suppression of cell proliferation and induction of apoptosis process. The results obtained by impedimetric method are correlated well with conventional in vitro assays such as flow cytometry, cell viability assays and microscopic imaging. Finally an empirical relation between cell impedance, electrode area and drug dose is established from impedance data which exhibits a negative correlation between drug doses and impedance of cancer cells.


Subject(s)
Biological Assay/instrumentation , Biosensing Techniques/instrumentation , Breast Neoplasms/drug therapy , Breast Neoplasms/physiopathology , Dielectric Spectroscopy/instrumentation , Drug Evaluation, Preclinical/instrumentation , Piperidines/administration & dosage , Quinazolines/administration & dosage , Antineoplastic Agents/administration & dosage , Apoptosis/drug effects , Breast Neoplasms/diagnosis , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Equipment Design , Equipment Failure Analysis , Female , Humans , MCF-7 Cells , Reproducibility of Results , Sensitivity and Specificity , Treatment Outcome
11.
Mol Cancer ; 12(1): 122, 2013 Oct 20.
Article in English | MEDLINE | ID: mdl-24138843

ABSTRACT

BACKGROUND: The hypoxic environment of tumor region stimulated the up regulation of growth factors responsible for angiogenesis and tumor proliferation. Thus, targeting the tumor vasculature along with the proliferation by dual tyrosine kinase inhibitor may be the efficient way of treating advanced breast cancers, which can be further enhanced by combining with radiotherapy. However, the effectiveness of radiotherapy may be severely compromised by toxicities and tumor resistance due to radiation-induced adaptive response contributing to recurrence and metastases of breast cancer. The rational of using ZD6474 is to evaluate the feasibility and efficacy of combined VEGFR2 and EGFR targeting with concurrent targeted and localized UV-B phototherapy in vitro breast cancer cells with the anticipation to cure skin lesions infiltrated with breast cancer cells. MATERIALS AND METHODS: Breast cancer cells were exposed to UV-B and ZD6474 and the cell viability, apoptosis, invasion and motility studies were conducted for the combinatorial effect. Graphs and statistical analyses were performed using Graph Pad Prism 5.0. RESULTS: ZD6474 and UV-B decreased cell viability in breast cancers in combinatorial manner without affecting the normal human mammary epithelial cells. ZD6474 inhibited cyclin E expression and induced p53 expression when combined with UV-B. It activated stress induced mitochondrial pathway by inducing translocation of bax and cytochrome-c. The combination of ZD6474 with UV-B vs. either agent alone also more potently down-regulated the anti-apoptotic bcl-2 protein, up-regulated pro-apoptotic signaling events involving expression of bax, activation of caspase-3 and caspase-7 proteins, and induced poly (ADP-ribose) polymerase resulting in apoptosis. ZD6474 combined with UV-B inhibited invasion of breast cancer cells in vitro as compared to either single agent, indicating a potential involvement of pro-angiogenic growth factors in regulating the altered expression and reorganization of cytoskeletal proteins in combinatorial treated breast cancer cells. Involvement of combination therapy in reducing the expression of matrix metalloprotease was also observed. CONCLUSIONS: Collectively, our studies indicate that incorporating an anti-EGFR plus VEGFR strategy (ZD6474) with phototherapy (UV-B), an alternative approach to the ongoing conventional radiotherapy for the treatment of infiltrating metastatic breast cancer cells in the skin and for locally recurrence breast cancer than either approach alone.


Subject(s)
Breast Neoplasms/therapy , ErbB Receptors/metabolism , Piperidines/pharmacology , Quinazolines/pharmacology , Ultraviolet Rays , Vascular Endothelial Growth Factor Receptor-2/metabolism , Apoptosis/drug effects , Apoptosis/radiation effects , Caspase 3/metabolism , Caspase 7/metabolism , Cell Movement/drug effects , Cell Movement/radiation effects , Cell Proliferation , Cell Survival/drug effects , Cell Survival/radiation effects , Combined Modality Therapy , Cytoskeleton/metabolism , ErbB Receptors/antagonists & inhibitors , Female , Humans , MCF-7 Cells , Matrix Metalloproteinase 9/metabolism , Membrane Potential, Mitochondrial/drug effects , Membrane Potential, Mitochondrial/radiation effects , Molecular Targeted Therapy , Phototherapy , Ultraviolet Therapy , Vascular Endothelial Growth Factor A/metabolism , Vascular Endothelial Growth Factor Receptor-2/antagonists & inhibitors
12.
Life Sci ; 93(21): 783-90, 2013 Nov 13.
Article in English | MEDLINE | ID: mdl-24044882

ABSTRACT

AIM: Thymoquinone (TQ), the predominant bioactive constituent of black seed oil (Nigella Sativa), has been shown to possess antineoplastic activity against multifarious tumors. However, the meticulous mechanism of TQ on Akt mediated survival pathway is still unrevealed in breast cancer. Here, we investigated TQ's mechanism of action against PI3K/Akt signaling and its downstream targets by modulating proteins translational machinery, leading to apoptosis in cancer cells. MAIN METHODS: MDA-MB-468 and T-47D cells were treated with TQ and evaluated for its anticancer activity through phase distribution and western blot. Modulatory effects of TQ on Akt were affirmed through kinase and drug potential studies. KEY FINDINGS: Studies revealed G1 phase arrest till 24h incubation with TQ while extended exposure showed phase shift to subG1 indicating apoptosis, supported by suppression of cyclin D1, cyclin E and cyclin dependent kinase inhibitor p27 expression. Immunoblot and membrane potential studies revealed mitochondrial impairment behind apoptotic process with upregulation of Bax, cytoplasmic cytochrome c and procaspase-3, PARP cleavage along with Bcl-2, Bcl-xL and survivin downregulation. Moreover, we construed the rationale behind mitochondrial dysfunction by examining the phosphorylation status of PDK1, PTEN, Akt, c-raf, GSK-3ß and Bad in TQ treated cells, thus ratifying the involvement of Akt in apoptosis. Further, the consequential effect of Akt inhibition by TQ is proven by translational repression through deregulated phosphorylation of 4E-BP1, eIF4E, S6R and p70S6K. SIGNIFICANCE: Our observations for the first time may provide a new insight for the development of novel therapies for Akt overexpressed breast cancer by TQ.


Subject(s)
Apoptosis/drug effects , Benzoquinones/pharmacology , Breast Neoplasms/pathology , Cyclin D1/biosynthesis , G1 Phase Cell Cycle Checkpoints/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Proto-Oncogene Proteins c-akt/antagonists & inhibitors , Antineoplastic Agents, Phytogenic/pharmacology , Apoptosis Regulatory Proteins/drug effects , Apoptosis Regulatory Proteins/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Female , Humans , MCF-7 Cells , Membrane Potential, Mitochondrial/drug effects , Molecular Targeted Therapy , Protein Biosynthesis/drug effects , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction/drug effects
13.
BMC Cancer ; 13: 273, 2013 Jun 03.
Article in English | MEDLINE | ID: mdl-23731702

ABSTRACT

BACKGROUND: Tamoxifen (TAM) is widely used in the chemotherapy of breast cancer and as a preventive agent against recurrence after surgery. However, extended TAM administration for breast cancer induces increased VEGF levels in patients, promoting new blood vessel formation and thereby limiting its efficacy. Celecoxib (CXB), a selective COX-2 inhibitor, suppresses VEGF gene expression by targeting the VEGF promoter responsible for its inhibitory effect. For this study, we had selected CXB as non-steroidal anti-inflammatory drug in combination with TAM for suppressing VEGF expression and simultaneously reducing doses of both the drugs. METHODS: The effects of CXB combined with TAM were examined in two human breast cancer cell lines in culture, MCF7 and MDA-MB-231. Assays of proliferation, apoptosis, angiogenesis, metastasis, cell cycle distribution, and receptor signaling were performed. RESULTS: Here, we elucidated how the combination of TAM and CXB at nontoxic doses exerts anti-angiogenic effects by specifically targeting VEGF/VEGFR2 autocrine signaling through ROS generation. At the molecular level, TAM-CXB suppresses VHL-mediated HIF-1α activation, responsible for expression of COX-2, MMP-2 and VEGF. Besides low VEGF levels, TAM-CXB also suppresses VEGFR2 expression, confirmed through quantifying secreted VEGF levels, luciferase and RT-PCR studies. Interestingly, we observed that TAM-CXB was effective in blocking VEGFR2 promoter induced expression and further 2 fold decrease in VEGF levels was observed in combination than TAM alone in both cell lines. Secondly, TAM-CXB regulated VEGFR2 inhibits Src expression, responsible for tumor progression and metastasis. FACS and in vivo enzymatic studies showed significant increase in the reactive oxygen species upon TAM-CXB treatment. CONCLUSIONS: Taken together, our experimental results indicate that this additive combination shows promising outcome in anti-metastatic and apoptotic studies. In a line, our preclinical studies evidenced that this additive combination of TAM and CXB is a potential drug candidate for treatment of breast tumors expressing high levels of VEGF and VEGFR2. This ingenious combination might be a better tailored clinical regimen than TAM alone for breast cancer treatment.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Autocrine Communication/drug effects , Breast Neoplasms/metabolism , Neovascularization, Pathologic , Receptors, Vascular Endothelial Growth Factor/metabolism , Vascular Endothelial Growth Factor A/metabolism , Animals , Blotting, Western , Celecoxib , Cell Line, Tumor , Cell Proliferation/drug effects , Female , Humans , Mice , Neovascularization, Pathologic/chemically induced , Pyrazoles/administration & dosage , Reactive Oxygen Species/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction/drug effects , Sulfonamides/administration & dosage , Tamoxifen/administration & dosage , Tamoxifen/adverse effects , Transfection , Xenograft Model Antitumor Assays
14.
ACS Appl Mater Interfaces ; 5(11): 5232-8, 2013 Jun 12.
Article in English | MEDLINE | ID: mdl-23730930

ABSTRACT

Recently, photoresponsive nanoparticles have received significant attention because of their ability to provide spatial and temporal control over the drug release. In the present work, we report for the first time photoresponsive multifunctional magnetic nanoparticles (MNPs) fabricated using coumarin-based phototrigger and Fe/Si MNPs for controlled delivery of anticancer drug chlorambucil. Further, newly fabricated photoresponsive multifunctional MNPs were also explored for cell luminescence imaging. In vitro biological studies revealed that coumarin tethered Fe/Si MNPs of ~9 nm size efficiently delivered the anticancer drug chlorambucil into cancer cells and thereby improving the drug action to kill the cancer cells upon irradiation. Such multifunctional MNPs with strong fluorescence, good biocompatibility and efficient photocontrolled drug release ability will be of great benefit in the construction of light-activated multifunctional nano drug delivery systems.


Subject(s)
Antineoplastic Agents, Alkylating/pharmacokinetics , Breast Neoplasms/drug therapy , Chlorambucil/pharmacokinetics , Drug Delivery Systems/methods , Hymecromone/analogs & derivatives , Metal Nanoparticles/chemistry , Antineoplastic Agents, Alkylating/chemistry , Apoptosis/drug effects , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Cycle/drug effects , Cell Division/drug effects , Cell Line, Tumor , Chlorambucil/chemistry , Female , Humans , Hydrogen-Ion Concentration , Hymecromone/chemistry , Hymecromone/pharmacokinetics , Light , Magnetic Fields , Metal Nanoparticles/radiation effects , Microscopy, Electron, Transmission , Photochemical Processes , Ultraviolet Rays
15.
PLoS One ; 8(4): e61342, 2013.
Article in English | MEDLINE | ID: mdl-23613836

ABSTRACT

X-linked inhibitor of apoptosis protein (XIAP) is constitutively expressed endogenous inhibitor of apoptosis, exhibit its antiapoptotic effect by inactivating key caspases such as caspase-3, caspase-7 and caspase-9 and also play pivotal role in rendering cancer chemoresistance. Our studies showed the coadministration of TQ and TAM resulting in a substantial increase in breast cancer cell apoptosis and marked inhibition of cell growth both in vitro and in vivo. Anti-angiogenic and anti-invasive potential of TQ and TAM was assessed through in vitro studies. This novel combinatorial regimen leads to regulation of multiple cell signaling targets including inactivation of Akt and XIAP degradation. At molecular level, TQ and TAM synergistically lowers XIAP expression resulting in binding and activation of caspase-9 in apoptotic cascade, and interfere with cell survival through PI3-K/Akt pathway by inhibiting Akt phosphorylation. Cleaved caspase-9 further processes other intracellular death substrates such as PARP thereby shifting the balance from survival to apoptosis, indicated by rise in the sub-G1 cell population. This combination also downregulates the expression of Akt-regulated downstream effectors such as Bcl-xL, Bcl-2 and induce expression of Bax, AIF, cytochrome C and p-27. Consistent with these results, overexpression studies further confirmed the involvement of XIAP and its regulatory action on Akt phosphorylation along with procaspase-9 and PARP cleavage in TQ-TAM coadministrated induced apoptosis. The ability of TQ and TAM in inhibiting XIAP was confirmed through siRNA-XIAP cotransfection studies. This novel modality may be a promising tool in breast cancer treatment.


Subject(s)
Apoptosis/drug effects , Benzoquinones/pharmacology , Breast Neoplasms/enzymology , Breast Neoplasms/pathology , Proto-Oncogene Proteins c-akt/metabolism , Tamoxifen/pharmacology , X-Linked Inhibitor of Apoptosis Protein/metabolism , Animals , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Breast Neoplasms/blood supply , Cell Cycle/drug effects , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Cell Survival/drug effects , Dose-Response Relationship, Drug , Down-Regulation/drug effects , Drug Synergism , Female , Glycogen Synthase Kinase 3/metabolism , Glycogen Synthase Kinase 3 beta , Humans , Mice , Neoplasm Invasiveness , Neovascularization, Pathologic/drug therapy , Phosphorylation/drug effects , Signal Transduction/drug effects , Xenograft Model Antitumor Assays , bcl-Associated Death Protein/metabolism
16.
Eur J Cancer Prev ; 21(2): 205-15, 2012 Mar.
Article in English | MEDLINE | ID: mdl-21876437

ABSTRACT

Carcinogenesis is a multistep process exhibiting deregulation in multiple cellular signaling pathways. Therefore, specific agent based treatments that target only one pathway usually fail in cancer therapy. The combination treatments using chemotherapeutic agents with distinct molecular mechanisms are considered more promising for higher efficacy; however, using multiple agents contributes to added toxicity. However, the in-vitro and in-vivo studies in the last few decades have demonstrated that some phytochemicals derived from 'natural products' such as fruits, vegetables and certain spices, referred to as chemopreventive agents, including capsaicin, trans-anethole, thymoquinone, diosgenin, allicin, can not only reduce the risk of acquiring specific cancer but also have been shown to suppress cancer cell proliferation, inhibit growth factor signaling pathways, induce apoptosis, inhibit nuclear factor-κB, AP-1, Akt, MAPK, Wnt, Notch, p53, AR, ER, and JAK-STAT, etc., activation pathways, inhibit angiogenesis, suppress the expression of antiapoptotic proteins, and inhibit cyclooxygenase-2. This study describes the above active components of some of the major spices, their mechanisms of action and their potential in prevention of various cancers.


Subject(s)
Antineoplastic Agents, Phytogenic/therapeutic use , Neoplasms/drug therapy , Plant Extracts/therapeutic use , Spices , Animals , Antineoplastic Agents, Phytogenic/pharmacology , Capsaicin/pharmacology , Capsaicin/therapeutic use , Diosgenin/pharmacology , Diosgenin/therapeutic use , Humans , Models, Biological , Plant Extracts/chemistry , Plant Extracts/pharmacology , Signal Transduction/drug effects , Signal Transduction/physiology
17.
J Exp Ther Oncol ; 9(3): 187-99, 2011.
Article in English | MEDLINE | ID: mdl-22070050

ABSTRACT

Immunohistochemical markers have been proposed for thyroid cancer diagnosis and prognostic studies. Immunohistochemical analysis of CK-19, NF-kappaB, beta-catenin, E-cadherin and EGFR were done to evaluate their diagnostic and prognostic efficiencies in eighty eight cancer specimen (PTC-52, FTC-16, benign nodule-12 and MNG-8). CK-19 was positive in 91% (62/68) DTC, 98% (51/52) PTC, 69% (11/16) FTC and 15% (3/20) benign thyroid nodules. NF-kappaB was expressed 93% (63/68) DTC, in 96% (50/52) PTC, 81% (11/16) FTC and 15% (3/20) benign thyroid nodules. Both CK-19 and NF-kappaB were significantly differentiated DTC, PTC and FTC from benign thyroid nodule (p < 0.0001) with diagnostic accuracy of 89.74%, 94.4% and 77.4% for CK-19 and 91.0%, 90.5% and 83.5% respectively for NF-kappaB. Though CK-19 and NF-kappaB were equally sensitive but CK-19 was most specific in the diagnosis of DTC and PTC. The diagnostic accuracy of beta-catenin was 96% and 94% and accuracy of E-cadherin was 90.1% and 93.9% for the diagnosis of metastatic PTC and FTC respectively. EGFR showed 90% (18/20) of metastatic PTC (p < 0.0001) and sensitivity, specificity and accuracy were 90%, 71.8% and 78.85% respectively. CK-19 and NF-kappaB were accurately diagnosed in DTC, PTC and FTC whereas, NF-kappaB, E-cadherin, beta-catenin and EGFR were strongly expressed in invasive papillary thyroid cancers and FTC, thus can be important diagnostic and prognostic marker for FTC and metastatic PTC. This may be concluded that immunohistochemical expression of panel of markers CK-19, NF-kappaB, E-cadherin, beta-catenin and EGFR can be useful in diagnosis and prognosis of DTC.


Subject(s)
Biomarkers, Tumor/analysis , Carcinoma, Papillary/diagnosis , Thyroid Neoplasms/diagnosis , Cadherins/analysis , Carcinoma, Papillary/pathology , ErbB Receptors/analysis , Humans , Immunohistochemistry , Keratin-19/analysis , NF-kappa B/analysis , Prognosis , Sensitivity and Specificity , Thyroid Neoplasms/pathology , beta Catenin/analysis
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