Exosomes: A Forthcoming Era of Breast Cancer Therapeutics.

Despite the recent advancements in therapeutics and personalized medicine, breast cancer remains one of the most lethal cancers among women. The prognostic and diagnostic aids mainly include assessment of tumor tissues with conventional methods towards better therapeutic strategies. However, current era of gene-based research may influence the treatment outcome particularly as an adjunct to diagnostics by exploring the role of non-invasive liquid biopsies or circulating markers. The characterization of tumor milieu for physiological fluids has been central to identifying the role of exosomes or small extracellular vesicles (sEVs). These exosomes provide necessary communication between tumor cells in the tumor microenvironment (TME). The manipulation of exosomes in TME may provide promising diagnostic/therapeutic strategies, particularly in triple-negative breast cancer patients. This review has described and highlighted the role of exosomes in breast carcinogenesis and how they could be used or targeted by recent immunotherapeutics to achieve promising intervention strategies.

Cancer immunotherapy: a promising dawn in cancer research.

Cancer is a highly proliferative disease, which is caused due to the loss of regulation of cell cycle and apoptosis, DNA damage, faulty repair system etc. The cancer microenvironment plays a pivotal role in disease progression as they contain different types of innate and adaptive immune cells. The most important molecules that establish a correlation between inflammation, innate immunity, adaptive immunity, and cancer are the molecules released by inflammatory cells in cancer microenvironment. These molecules secreted by the immune cells, which might activate a pro-tumorigenic and anti-tumorigenic response in cancer. In inflammatory microenvironment, the equilibrium state of immunosuppressive and immunostimulatory signals are important in tumor suppression. The immunotherapeutic approaches could be more effective in cancer treatment. However, advancement in immunobiology and cancer are improving the prospects of immunotherapy alone and/or in combination with the conventional therapies. Thus, the review attempts to highlight a promising and futuristic immunotherapeutic approach in combination with conventional treatment modalities.

Differential expression of Ets-1 in breast cancer among North Indian population.

Breast cancer is a highly aggressive disease contributing to high mortality rate among females across the globe owing to wide geographical variations, change in lifestyle along with rapid tumor growth, drug resistance, and high metastasis rate. To understand the molecular and genetic basis of breast cancer progression; we studied the role of E26 transformation-specific-1 (Ets-1) transcription factor which is implicated to have a role in carcinogenesis like invasion, metastasis, angiogenesis, etc. Our findings revealed an overexpression of Ets-1 gene in 75 breast cancer tumors as compared with their normal adjacent tissues. The findings significantly established a co-relation between Ets-1 expression in breast cancer tissue with hormonal receptor profiles and ductal-lobular histological subtypes in Indian population. In addition, a differential expression pattern of Ets-1 was observed between high, moderate, and low grades of breast cancer patients. The present study demonstrates a crucial role of Ets-1 transcription factor which may serve as a potential biomarker for breast carcinogenesis.

Simultaneous knockdown of uPA and MMP9 can reduce breast cancer progression by increasing cell-cell adhesion and modulating EMT genes.

In cancer progression, proteolytic enzymes like serine proteases and metalloproteinases degrade the basement membrane enabling the tumor cells to invade the adjacent tissues. Thus, invasion and metastasis are augmented by these enzymes. Simultaneous silencing of uPA and MMP9 in breast cancer cells decreased the wound healing, migratory, invasive and adhesive capacity of the cells. After simultaneous down regulation, cells were seen to be arrested in the cell cycle. There was a remarkable increase in the expression of cell to cell adhesion molecule E-cadherin, and decrease in Vimentin and Snail expression. In addition, there was a significant decrease in the expression of the stem cell marker Oct-4. In the breast tumor samples it has been observed that, tumors, expressing higher level of uPA and MMP9, express less amount of E-cadherin. It has also been observed that few tumors also show, Vimentin positive in the ductal epithelial area. Thus, our model can help for checking the aggressive tumor invasion by blocking of uPA and MMP9. Our present observations also give the concept of the presence of aggressive epithelial cells with mesenchymal nature in the tumor micro-environment, altering the expression of EMT genes.

A novel zinc(II) and hydrogen sulphate selective fluorescent "turn-on" chemosensor based on isonicotiamide: INHIBIT type's logic gate and application in cancer cell imaging.

We have developed a novel isonicotiamide-based fluorescent "turn-on" chemosensor 1 for the selective detection of Zn(2+) and HSO4(-). The sensor 1 can detect Zn(2+) and HSO4(-) with a detection limit down to the nanomolar level by forming a complex in 1 : 1 stoichiometry in the presence of other anions and 2 : 1 in presence of cations in aqueous solution. Density functional theory calculations on 1 and the 1-Zn(2+)/HSO4(-) complexes are consistent with the experimental results. We have successfully utilized the above cation and anion for the fabrication of INHIBIT molecular logic gates. Furthermore the receptor 1 successfully detected the Zn(2+) and HSO4(-) ions in HeLa cells cultured in Zn(2+) and HSO4(-) enriched medium.

Pyrrole-coupled salicylimine-based fluorescence "turn on" probe for highly selective recognition of Zn²âº ions in mixed aqueous media: Application in living cell imaging.

Cation sensing behaviour of a pyrrole-based derivative (2-hydroxyl 3 methyl 6 isopropyl benzaldehyde}-3,4-dimethyl-1H-pyrrole-2-carbohydrazide (receptor 3) has been explored and is found to be selective towards Zn(2+) over a variety of tested cations. The receptor 3 has shown high selectivity and sensitivity towards Zn(2+) over the other alkali, alkaline earth and transition metal ions. In the presence of Zn(2+), absorption band of receptor 3 has shown the red shift. The sensing behaviour has been suggested to continue via enhancement process which has further been supported by UV-vis absorption and theoretical density functional theory (DFT) calculations indicating the formation of a 1:1 complex between the pyrrole based receptor 3 and Zn(2+). The present work is presenting a highly selective dual channel colorimetric sensor for zinc with great sensitivity. The developed sensor was successfully applied to image intracellular Zn(2+) in living cells.

Innate adjuvant receptor Toll-like receptor 3 can promote breast cancer through cell surface.

Toll-like receptor 3 has been targeted in different cancers for adjuvant therapy. The ligand-mediated effects of TLR-3 on cancer cells are discordant. In the present work, we have addressed the hypothesis possibility of cell membrane-bound action of TLR-3 in breast cancer to justify its pro-tumor effect. TLR-3 was stimulated by Poly (I:C) on the surface of human breast cancer cells MCF-7 and MDA-MB-231 for up to 72 h. To check the cell survival and growth, thiazol blue tetrazolium bromide (MTT) assay, apoptosis assay, and cell cycle analysis were carried out. For changes in the metastatic properties, in vitro colony formation assay, scratch-wound healing assay and adhesion assay were also done. Using real-time PCR and immunocytochemistry, expression of E-cadherin, was studied. To determine the affect of cytoplasmic stimulation, Poly (I:C) was delivered with lipid transfection reagent. The results of the aforesaid experiments showed that there was a gradual increase of cellular survivability, growth, and metastasis after the cell surface stimulation of TLR-3 with Poly (I:C). Interestingly, E-cadherin expression was increased both at transcriptional and translational level. On the other hand, when Poly (I:C) was delivered in the cytoplasm by lipid transfecting medium, the cells survivability was decreased. For the first time, in the present work, we are convincingly reporting the functional evidence that TLR-3 induces cell survivability and metastasis through cell surface. The present work may help for the proper understanding of the adjuvant therapy of breast cancer.

A novel phthalazine based highly selective chromogenic and fluorogenic chemosensor for Co(2+) in semi-aqueous medium: application in cancer cell imaging.

A new phthalazine based chemosensor was developed for the highly selective and sensitive detection of Co(2+) in the mixed solvent system, CH3CN-H2O (1 : 1, v/v). In the presence of Co(2+), the colour of the solution changed from yellow to green; the absorption maxima of was red-shifted from 383 nm to 435 nm, and the fluorescence of at 550 nm was significantly enhanced. The sensor showed a detection limit down to 25 nM by forming a complex species with Co(2+) in 1 : 1 stoichiometry. Furthermore, by means of confocal laser scanning microscopy experiments, it has demonstrated that it can be used as a fluorescent probe for monitoring Co(2+) in living cells.

A highly selective fluorescent 'turn-on' chemosensor for Zn(2+) based on a benzothiazole conjugate: their applicability in live cell imaging and use of the resultant complex as a secondary sensor of CN(-).

A benzothiazole derivative linked "off-on" multi-responsive and selective chemosensor has been synthesized and evaluated for cation recognition properties. The receptor shows a high sensitivity and selectivity for Zn(2+) through a 'turn-on' fluorescence response over the other tested cations with a detection limit as low as 0.67 µM. The receptor was successfully applied for the detection of Zn(2+) in live HeLa cells. Then, the Zn(2+) complex of receptor was also used for cyanide detection and recognition.

Highly selective turn-on fluorescent sensor for nanomolar detection of biologically important Zn2+ based on isonicotinohydrazide derivative: application in cellular imaging.

A new Zn(2+) selective chemosensor (3) was synthesized by condensation of commercially available substituted salicylaldehyde and isonicotinohydrazide, and characterized by single crystal X-ray crystallography. Receptor 3 with Zn(2+) exhibited a highly selective and pronounced enhancement in the fluorescence emission among different cations by forming a 2:1 complex. The receptor can detect Zn(2+) up to nanomolar level (6.75 nM) with good tolerance of other metal ions and can be used for in vitro cellular imaging.

"Turn-on" fluorescent chemosensor for zinc(II) dipodal ratiometric receptor: application in live cell imaging.

A dipodal ligand 2,2'-((ethane-1,2-diylbis(azanediyl))bis(ethane-1,1-diyl))diphenol was synthesized through a condensation reaction and was characterized with IR, (1)H NMR, (13)C-NMR, and mass spectroscopy. The receptor 2 has shown marked enhancement in fluorescence intensity (emission signal at 341 nm) on binding with Zn(2+) as compared to other surveyed metal ions. The sensor has shown dramatic changes in dual channel fluorescence emission with λmax at 300 and 341 nm. The successive addition of Zn(2+) to the solution of the sensor led to a blue shift of the peak maxima and interestingly upon addition of higher equivalents of Zn(2+) quenched the fluorescence intensity of the sensor, and ultimately the original fluorescent profile of sensor was restored. The structures of 2 and 3 were optimized with B3LYP/LanL2DZ basis sets. The receptor 2 successfully detect the Zn(2+) ion in HeLa cells cultured in Zn(2+) enriched medium.

"Turn-on" fluorescent dipodal chemosensor for nano-molar detection of Zn(2+): application in living cells imaging.

A malonohydrazide derivative bearing an imine and phenolic group was synthesized and had a high affinity and selectivity towards Zn(2+). The recognition properties of receptor 1 were evaluated using absorbance and fluorescence spectroscopy. The 1:1 stoichiometry of 1.Zn(2+) was confirmed from job's plot, mass spectra and density functional theory (DFT). The detection of Zn(2+) in intracellular environment of HeLa cell through confocal microscopy was successfully applied for live cell imaging.

A novel urea-linked dipodal naphthalene-based fluorescent sensor for Hg(II) and its application in live cell imaging.

A novel cell-permeable urea-linked dipodal naphthalene-based fluorescent receptor 1 (1,1'-(1,5,5-trimethyl-3-oxocyclohexane-1,2-diyl)bis(3-(naphthalen-2-yl)urea) was designed and synthesized. The cation recognition ability of 1 was evaluated with a library of metal ions in DMSO/H2O (9:1, v/v). The receptor showed a selective chromogenic and fluorescent turn-off response towards Hg(2+) among the surveyed metal ions. The developed sensor was successfully applied to image intracellular Hg(2+) in living cells and also for the determination of Hg(2+) content in real water samples. Moreover, the DFT calculations were performed to complement the experimental evidences.