Alin Moldovan - Academia.edu (original) (raw)

Papers by Alin Moldovan

Research paper thumbnail of Correction to: New insights in gene expression alteration as effect of doxorubicin drug resistance in triple negative breast cancer cells

An amendment to this paper has been published and can be accessed via the original article.

Research paper thumbnail of Hsa-miR-125b Therapeutic Role in Colon Cancer Is Dependent on the Mutation Status of the TP53 Gene

Colon cancer is the third most common cancer type worldwide and is highly dependent on DNA mutati... more Colon cancer is the third most common cancer type worldwide and is highly dependent on DNA mutations that progressively appear and accumulate in the normal colon epithelium. Mutations in the TP53 gene appear in approximately half of these patients and have significant implications in disease progression and response to therapy. miR-125b-5p is a controversial microRNA with a dual role in cancer that has been reported to target specifically TP53 in colon adenocarcinomas. Our study investigated the differential therapeutic effect of miR-125b-5p replacement in colon cancer based on the TP53 mutation status of colon cancer cell lines. In TP53 mutated models, miR-125b-5p overexpression slows cancer cells’ malignant behavior by inhibiting the invasion/migration and colony formation capacity via direct downregulation of mutated TP53. In TP53 wild type cells, the exogenous modulation of miR-125b-5p did not significantly affect the molecular and phenotypic profile. In conclusion, our data sho...

Research paper thumbnail of ff ects of Low-Dose Irradiation on Human Saliva : A Surface-Enhanced Raman Spectroscopy Study

Biological effects of low-dose ionizing radiation (IR) have been unclear until now. Saliva, becau... more Biological effects of low-dose ionizing radiation (IR) have been unclear until now. Saliva, because of the ease of collection, could be valuable in studying low-dose IR effects by means of surface-enhanced Raman spectroscopy (SERS). The objective of our study was to compare the salivary SER spectra recorded before and after low-dose IR exposure in the case of pediatric patients (PP). Unstimulated saliva was collected from ten PP before and after irradiation with a cone beam computed tomography (CBCT) machine used for diagnostic purposes. The SERS measurements have been recorded on dried saliva samples using a solid nanosilver plasmonic substrate synthesized using an original method developed in our laboratory. The experimental results showed that salivary SER spectra are dominated by three vibrational bands (441,735 and 2107 cm−1) that can be assigned to bending and stretching vibrations of salivary thiocyanate (SCN-). After exposure, an immediate increase of vibrational bands assig...

Research paper thumbnail of The silent healer: miR-205-5p up-regulation inhibits epithelial to mesenchymal transition in colon cancer cells by indirectly up-regulating E-cadherin expression

Cell death & disease, Jan 19, 2018

EMT represents the dominant program within advanced stages of colon cancer, where cells acquire m... more EMT represents the dominant program within advanced stages of colon cancer, where cells acquire migratory characteristics in order to invade secondary tissues and form metastasis. Where the majority of the therapeutic strategies are concentrated on the reduction of the tumor mass through different apoptotic mechanisms, the present study advocates an important role for miR-205-5p in impairment of colon cancer cells migration and restoration of the epithelial phenotype. Upon identification of a homogenous downregulated profile for miR-205-5p in colon adenocarcinoma patients, functional studies demonstrated that experimental upregulation of this sequence is able to significantly raise the levels of E-cadherin through direct inhibition of ZEB1. Moreover, the elevation in CDH1 expression was translated into functional parameters where cells lost their invasion and migratory characteristics and formed homogenous clusters through adhesion interactions. Survival analysis of colon adenocarci...

Research paper thumbnail of Exosome-carried microRNA-based signature as a cellular trigger for the evolution of chronic lymphocytic leukemia into Richter syndrome

Critical reviews in clinical laboratory sciences, Jan 21, 2018

Even if considered a cumulative and not a proliferative CD5+ B-cell neoplasm, chronic lymphocytic... more Even if considered a cumulative and not a proliferative CD5+ B-cell neoplasm, chronic lymphocytic leukemia (CLL) has a proliferation rate higher than that recognized earlier, especially in the lymphoid tissues. Some patients with CLL develop a clinical syndrome entitled Richter syndrome (RS). Understanding CLL genetics and epigenetics may help to elucidate the molecular basics of the clinical heterogeneity of this type of malignancy. In the present project we aimed to identify a microRNA species that can predict the evolution of therapy-resistant CLL towards RS. In the first phase of our study, microRNA-19b was identified as a possible target, and in the second phase, we transfected three different CLL cell lines with microRNA-19b mimic and inhibitor and assessed the potential role on leukemia cells in vitro. The mechanism by which miR-19b acts were identified as the upregulation of Ki67 and downregulation of p53. This was further supported through RT-PCR and western blotting on CLL...

Research paper thumbnail of Quantifying Cytosolic Cytochrome c Concentration Using Carbon Quantum Dots as a Powerful Method for Apoptosis Detection

Pharmaceutics

Background: Cytochrome c (Cyt c) is a key biomarker for early apoptosis, and many methods were de... more Background: Cytochrome c (Cyt c) is a key biomarker for early apoptosis, and many methods were designed to detect its release from mitochondria. For a proper evaluation of these programed cell death mechanisms, fluorescent nanoparticles are excellent candidates due to their valuable optical properties. Among all classes of nanoparticles developed thus far, carbon-based quantum dots bring qualitative and efficient imaging strategies for biomedical applications as a consequence of their biocompatibility and low cytotoxicity. Methods: In this study, we synthesized carbon quantum dots smaller than 5 nm from sodium citrate and polyethylene imine. These nanoparticles were rigorously characterized, and their quenching capacity in apoptotic events was assessed in A549 cells treated with staurosporine and etoposide. For the evaluation of Cyt c release, a phenomenon directly correlated with apoptotic events, we ran a semiquantitative analysis using confocal laser scanning microscopy. Results:...

Research paper thumbnail of Correction to: New insights in gene expression alteration as effect of doxorubicin drug resistance in triple negative breast cancer cells

Journal of Experimental & Clinical Cancer Research

An amendment to this paper has been published and can be accessed via the original article.

Research paper thumbnail of New insights in gene expression alteration as effect of doxorubicin drug resistance in triple negative breast cancer cells

Journal of Experimental & Clinical Cancer Research

Background Triple negative breast cancer (TNBC) is a heterogeneous disease with aggressive behavi... more Background Triple negative breast cancer (TNBC) is a heterogeneous disease with aggressive behavior and an unfavorable prognosis rate. Due to the lack of surface receptors, TNBC must be intensely investigated in order to establish a suitable treatment for patients with this pathology. Chemoresistance is an important reason for therapeutic failure in TNBC. Method The aim of this study was to investigate the effect of doxorubicin in TNBC cell lines and to highlight cellular and molecular alterations after a long exposure to doxorubicin. Results The results revealed that doxorubicin significantly increased the half maximal inhibitory concentration (IC50) values at P12 and P24 compared to parenteral cells P0. Modifications in gene expression were investigated through microarray technique, and for detection of mutational pattern was used Next Generation Sequencing (NGS). 196 upregulated and 115 downregulated genes were observed as effect of multiple dose exposure, and 15 overexpressed ge...

Research paper thumbnail of New perspectives in triple-negative breast cancer therapy based on treatments with TGFβ1 siRNA and doxorubicin

Molecular and Cellular Biochemistry

Triple-negative breast cancer (TNBC), which accounts for 10–20% of all breast cancers, has the wo... more Triple-negative breast cancer (TNBC), which accounts for 10–20% of all breast cancers, has the worst prognosis. Although chemotherapy treatment is a standard for TNBC, it lacks a specific target. Therefore, new therapeutic strategies are required to be investigated. In this study, a combined doxorubicin (DOX) and small interfering RNA (siRNA) therapy is proposed as therapeutic strategy for targeting TGFβ1 gene. Hs578T cell line is used as in vitro model for TNBC, wherein TGFβ1siRNA therapy is employed to enhance therapeutic effects. Cell proliferation rate is measured using an MTT test, and morphological alterations are assed using microscopically approached, while gene expression is determined by qRT-PCR analysis. The combined treatment of TGFβ1siRNA and DOX reduced levels of cell proliferation and mitochondrial activity and promoted the alteration of cell morphology (dark-field microscopy). DOX treatment caused downregulation of six genes and upregulation of another six genes. The combined effects of DOX and TGFβ1siRNA resulted in upregulation of 13 genes and downregulation of four genes. Silencing of TGFβ1 resulted in activation of cell death mechanisms in Hs578T cells, to potentiate the effects of DOX, but not in an additive manner, due to the activation of genes involved in resistance to therapy (ABCB1 and IL-6).

Research paper thumbnail of Inhibitory Effect of CAPE and Kaempferol in Colon Cancer Cell Lines—Possible Implications in New Therapeutic Strategies

International Journal of Molecular Sciences, Mar 9, 2019

Background: Phytochemicals are natural compounds synthesized as secondary metabolites in plants a... more Background: Phytochemicals are natural compounds synthesized as secondary metabolites in plants and represent an important source of molecules with therapeutic applications. Attention is accorded to their potential in anti-cancer therapies as single agents or adjuvant treatment. Herby, we evaluated the in vitro effects of a panel of natural compounds with focus on caffeic acid phenethyl ester (CAPE) and Kaempferol for the treatment of human colon cancer. Methods: We exposed two human colon cancer cell lines, RKO and HCT-116, followed by functional examination of cell viability, cell proliferation and invasion, cell cycle, apoptosis, and autophagy. Modifications in gene expression were investigated through microarray and detection of existing mutations and finding of new ones was done with the help of Next Generation Sequencing (NGS). Results: Both CAPE and Kaempferol inhibit cell proliferation, motility and invasion, and stimulate apoptosis and autophagy, concomitant with modifications in coding and noncoding genes' expression. Moreover, there are pathogenic mutations that are no longer found upon treatment with CAPE and Kaempferol. Conclusions: Our findings indicate that CAPE and Kaempferol have the ability to negatively influence the development and advancement of colon cancer in vitro by specifically altering the cells at the molecular level; this activity can be exploited in possible adjuvant therapies once the optimal dose concentration with minimal side effects but with cancer inhibitory activity is set in vivo.

Research paper thumbnail of PEGylated Gold Nanoparticles with Interesting Plasmonic Properties Synthesized Using an Original, Rapid, and Easy-to-Implement Procedure

In this letter, we report a new, one-step, rapid, and easy-to-implement method for the synthesis ... more In this letter, we report a new, one-step, rapid, and easy-to-implement method for the synthesis of PEGylated gold nanoparticles (PEG-AuNPs) having a narrow size distribution and very interesting plasmonic properties. Unmodified polyethylene glycol molecules with a molecular weight of 1000 g/mole (PEG1000) have been employed as reducing and capping agents for the synthesis of spherical gold nanoparticles having an average diameter of 35 nm, within a few minutes. The novelty of the herein proposed synthesis method consists in the fact that the synthesis takes place inside of a sealed bottle flask containing aqueous solutions of PEG1000, tetrachloroauric(III) acid (HAuCl 4), and NaOH, placed in the center of a microwave oven, capable to provide a very uniform temperature environment. It turned out that, during the very short synthesis procedure (2 minutes), PEG 1000 suffers an oxidative transformation in such a manner that its terminal alcohol groups (-CH 2-OH) are transformed in carboxylate ones (-COO −). The as-synthesized PEG-AuNPs possess very interesting plasmonic properties allowing the detection of different molecules by means of SER spectroscopy performed either in liquid droplets or on solid spots. As a consequence of their unique plasmonic properties, the SER spectra acquired using this new class of nanoparticles on different molecules of interest (methylene blue, rhodamine 6G, doxorubicin, and 5-fluorouracil) are highly reproducible, making them ideal candidates for further use as SERS substrates.

Research paper thumbnail of Gold nanorods: from anisotropy to opportunity. An evolution update

Nanomedicine

Gold nanoparticles have drawn attention to nanomedicine for many years due to their physicochemic... more Gold nanoparticles have drawn attention to nanomedicine for many years due to their physicochemical properties, which include: good stability; biocompatibility; easy surface chemistry and superior magnetic; and last, electronic properties. All of these properties distinguish gold nanoparticles as advantageous carriers to be exploited. The challenge to develop new gold nanostructures has led to anisotropy, a new property to exploit for various medical applications: diagnostic and imaging strategies as well as therapeutic options. Gold nanorods are the most studied anisotropic gold nanoparticles because of the presence of two absorption peaks according to their longitudinal and transversal plasmon resonances. The longitudinal surface plasmonic resonance can provide the absorption in the near-infrared region and this is an important aspect of using gold nanorods for medical purposes.

Research paper thumbnail of Inhibitory Effect of CAPE and Kaempferol in Colon Cancer Cell Lines—Possible Implications in New Therapeutic Strategies

International Journal of Molecular Sciences

Background: Phytochemicals are natural compounds synthesized as secondary metabolites in plants a... more Background: Phytochemicals are natural compounds synthesized as secondary metabolites in plants and represent an important source of molecules with therapeutic applications. Attention is accorded to their potential in anti-cancer therapies as single agents or adjuvant treatment. Herby, we evaluated the in vitro effects of a panel of natural compounds with focus on caffeic acid phenethyl ester (CAPE) and Kaempferol for the treatment of human colon cancer. Methods: We exposed two human colon cancer cell lines, RKO and HCT-116, followed by functional examination of cell viability, cell proliferation and invasion, cell cycle, apoptosis, and autophagy. Modifications in gene expression were investigated through microarray and detection of existing mutations and finding of new ones was done with the help of Next Generation Sequencing (NGS). Results: Both CAPE and Kaempferol inhibit cell proliferation, motility and invasion, and stimulate apoptosis and autophagy, concomitant with modificati...

Research paper thumbnail of In vitro study of BSA gel/polyelectrolite complexes core shell microcapsules encapsulating doxorubicin for antitumoral targeted treatment

International Journal of Polymeric Materials and Polymeric Biomaterials

Abstract The aim of this study is to develop core shell microcapsules of bovine serum albumin (BS... more Abstract The aim of this study is to develop core shell microcapsules of bovine serum albumin (BSA) gel with a complex polyelectrolite multilayer shell of natural polysaccharides with opposite charges, pectin (P), chitosan (Chi), and hyaluronic acid (HA) respectively, encapsulating Doxorubicin (Dox) as a carrier for targeted anti-tumoral treatment of hepatic cell carcinoma (HCC). A sacrificial CaCO3 template method was used in order to obtain microcapsules with a BSA gel core and a layer-by-layer (Lbl) deposition technique of polyelectrolite complexes formed between P/Chi in the inner layers and HA/Chi in the outer shell layers. The preformed microcapsules, BSA gel/P/Chi/HA, noted as ms, have been applied for Dox encapsulation (ms-Dox). Dox encapsulation and release in different pH media were studied in order to elucidate the interactions between pH dependently charged species involved in the Dox loading/releasing processes. The structure characterization of ms/ms-Dox was evaluated by FTIR and UV-Vis spectroscopy, X-ray diffraction, thermal analy sis, optical microscopy, confocal laser scanning microscopy, and scanning electron microscopy. The in vitro study for citotoxicity assessment on normal and tumoral cells of both ms and ms-Dox was performed using mesenchymal stem cells (MSCs) and Hep2G HCC cell lines. Results of physical-chemical analyses confirm the successful encapsulation of Dox in ms, and the in vitro biological study recommends ms-Dox as a candidate for future in vivo research as a targeted anti-tumoral treatment modality applications. Graphical Abstract

Research paper thumbnail of Aberrant miRNAs expressed in HER-2 negative breast cancers patient

Journal of Experimental & Clinical Cancer Research

Background: Breast cancer is a highly heterogeneous pathology, exhibiting a number of subtypes co... more Background: Breast cancer is a highly heterogeneous pathology, exhibiting a number of subtypes commonly associated with a poor outcome. Due to their high stability, microRNAs are often regarded as non-invasive cancer biomarkers, having an expression pattern specific for their 'cell of origin'. Method: Triple negative breast cancer (TNBC: ER-, PR-, Her-2-) and double positive breast cancer (DPBC: ER+, PR+, Her-2) miRNA expression patterns were obtained by analysis of the TCGA (The Cancer Genome Atlas) data, followed by PCR-array analysis on plasma samples from 20 TNBC patients, 14 DPBC patients and 11 controls. Results: Three downregulated and nine upregulated miRNAs were obtained from the TNBC analysis. Five overexpressed miRNAs were identified in the DPBC group. Four of the dysregulated miRNAs (miR-10a, miR-125b, miR-210 and miR-489) were common for both groups. The cluster miR-17-92 (miR-17, miR-20a, miR-20b, and miR-93), along with miR-130, miR-22 and miR-29a/c, were found to differentiate between TNBC and DPBC. A panel of five transcripts (miR-10a, miR-125, miR-193b, miR-200b and miR-489) was validated in a new set of plasma samples. The overlapping of TCGA and plasma profiling data revealed miR-200b, miR-200c, miR-210 and miR-29c as common signature. MiR-200b was validated on additional normal and tumor tissue samples. The expression level of this transcript from the TCGA data was correlated with lung and bone metastatic genes. Conclusion: The miR-200b presents a great potential for the future advancements in the diagnostic/prognostic and therapeutic approach of TNBC, along with other coding or non-coding transcripts. However, this needs to be further integrated in a regulatory network that acts in conjunction with other markers that affect the patients' prognosis or response to therapy.

Research paper thumbnail of The silent healer: miR-205-5p up-regulation inhibits epithelial to mesenchymal transition in colon cancer cells by indirectly up-regulating E-cadherin expression

Cell death & disease, Jan 19, 2018

EMT represents the dominant program within advanced stages of colon cancer, where cells acquire m... more EMT represents the dominant program within advanced stages of colon cancer, where cells acquire migratory characteristics in order to invade secondary tissues and form metastasis. Where the majority of the therapeutic strategies are concentrated on the reduction of the tumor mass through different apoptotic mechanisms, the present study advocates an important role for miR-205-5p in impairment of colon cancer cells migration and restoration of the epithelial phenotype. Upon identification of a homogenous downregulated profile for miR-205-5p in colon adenocarcinoma patients, functional studies demonstrated that experimental upregulation of this sequence is able to significantly raise the levels of E-cadherin through direct inhibition of ZEB1. Moreover, the elevation in CDH1 expression was translated into functional parameters where cells lost their invasion and migratory characteristics and formed homogenous clusters through adhesion interactions. Survival analysis of colon adenocarci...

Research paper thumbnail of CHARACTERIZATION OF As2S3 THIN SURFACE FILMS USING SEM AND AFM METHODS

UPB Scientific Bulletin, Series A: Applied Mathematics and Physics

In this paper we report several experimental results concerning the characterization of As2S3 thi... more In this paper we report several experimental results concerning the characterization of As2S3 thin films using scanning electron microscopy (SEM), and atomic force microscopy (AFM). The chalcogenide films were obtained by vacuum thermal deposition. The SEM and AFM analysis of the surfaces emphasized that in the above mentioned thin films, the nanometric structure of the surface is uniform and continuous, without cracks and has a roughness of about 10 nm. From the SEM analysis in fracture of the sample fabricated by the deposition of the As2S3 thin films on glass, we determined their thickness of about 150-160 nm. We highlighted its good adherence to the substrate and the absence of the holes between film and substrate. The investigation of the silver thin (50 nm) films obtained by pulsed laser deposition show the column and island surface topography that may induce light scattering and produce broadening of plasmonic dip. Further development should be done in order to increase surfa...

Research paper thumbnail of Small versus Large Iron Oxide Magnetic Nanoparticles: Hyperthermia and Cell Uptake Properties

Molecules, Oct 13, 2016

Efficient use of magnetic hyperthermia in clinical cancer treatment requires biocompatible magnet... more Efficient use of magnetic hyperthermia in clinical cancer treatment requires biocompatible magnetic nanoparticles (MNPs), with improved heating capabilities. Small (~34 nm) and large (~270 nm) Fe 3 O 4-MNPs were synthesized by means of a polyol method in polyethylene-glycol (PEG) and ethylene-glycol (EG), respectively. They were systematically investigated by means of X-ray diffraction, transmission electron microscopy and vibration sample magnetometry. Hyperthermia measurements showed that Specific Absorption Rate (SAR) dependence on the external alternating magnetic field amplitude (up to 65 kA/m, 355 kHz) presented a sigmoidal shape, with remarkable SAR saturation values of~1400 W/g MNP for the small monocrystalline MNPs and only 400 W/g MNP for the large polycrystalline MNPs, in water. SAR values were slightly reduced in cell culture media, but decreased one order of magnitude in highly viscous PEG1000. Toxicity assays performed on four cell lines revealed almost no toxicity for the small MNPs and a very small level of toxicity for the large MNPs, up to a concentration of 0.2 mg/mL. Cellular uptake experiments revealed that both MNPs penetrated the cells through endocytosis, in a time dependent manner and escaped the endosomes with a faster kinetics for large MNPs. Biodegradation of large MNPs inside cells involved an all-or-nothing mechanism.

Research paper thumbnail of Correction to: New insights in gene expression alteration as effect of doxorubicin drug resistance in triple negative breast cancer cells

An amendment to this paper has been published and can be accessed via the original article.

Research paper thumbnail of Hsa-miR-125b Therapeutic Role in Colon Cancer Is Dependent on the Mutation Status of the TP53 Gene

Colon cancer is the third most common cancer type worldwide and is highly dependent on DNA mutati... more Colon cancer is the third most common cancer type worldwide and is highly dependent on DNA mutations that progressively appear and accumulate in the normal colon epithelium. Mutations in the TP53 gene appear in approximately half of these patients and have significant implications in disease progression and response to therapy. miR-125b-5p is a controversial microRNA with a dual role in cancer that has been reported to target specifically TP53 in colon adenocarcinomas. Our study investigated the differential therapeutic effect of miR-125b-5p replacement in colon cancer based on the TP53 mutation status of colon cancer cell lines. In TP53 mutated models, miR-125b-5p overexpression slows cancer cells’ malignant behavior by inhibiting the invasion/migration and colony formation capacity via direct downregulation of mutated TP53. In TP53 wild type cells, the exogenous modulation of miR-125b-5p did not significantly affect the molecular and phenotypic profile. In conclusion, our data sho...

Research paper thumbnail of ff ects of Low-Dose Irradiation on Human Saliva : A Surface-Enhanced Raman Spectroscopy Study

Biological effects of low-dose ionizing radiation (IR) have been unclear until now. Saliva, becau... more Biological effects of low-dose ionizing radiation (IR) have been unclear until now. Saliva, because of the ease of collection, could be valuable in studying low-dose IR effects by means of surface-enhanced Raman spectroscopy (SERS). The objective of our study was to compare the salivary SER spectra recorded before and after low-dose IR exposure in the case of pediatric patients (PP). Unstimulated saliva was collected from ten PP before and after irradiation with a cone beam computed tomography (CBCT) machine used for diagnostic purposes. The SERS measurements have been recorded on dried saliva samples using a solid nanosilver plasmonic substrate synthesized using an original method developed in our laboratory. The experimental results showed that salivary SER spectra are dominated by three vibrational bands (441,735 and 2107 cm−1) that can be assigned to bending and stretching vibrations of salivary thiocyanate (SCN-). After exposure, an immediate increase of vibrational bands assig...

Research paper thumbnail of The silent healer: miR-205-5p up-regulation inhibits epithelial to mesenchymal transition in colon cancer cells by indirectly up-regulating E-cadherin expression

Cell death & disease, Jan 19, 2018

EMT represents the dominant program within advanced stages of colon cancer, where cells acquire m... more EMT represents the dominant program within advanced stages of colon cancer, where cells acquire migratory characteristics in order to invade secondary tissues and form metastasis. Where the majority of the therapeutic strategies are concentrated on the reduction of the tumor mass through different apoptotic mechanisms, the present study advocates an important role for miR-205-5p in impairment of colon cancer cells migration and restoration of the epithelial phenotype. Upon identification of a homogenous downregulated profile for miR-205-5p in colon adenocarcinoma patients, functional studies demonstrated that experimental upregulation of this sequence is able to significantly raise the levels of E-cadherin through direct inhibition of ZEB1. Moreover, the elevation in CDH1 expression was translated into functional parameters where cells lost their invasion and migratory characteristics and formed homogenous clusters through adhesion interactions. Survival analysis of colon adenocarci...

Research paper thumbnail of Exosome-carried microRNA-based signature as a cellular trigger for the evolution of chronic lymphocytic leukemia into Richter syndrome

Critical reviews in clinical laboratory sciences, Jan 21, 2018

Even if considered a cumulative and not a proliferative CD5+ B-cell neoplasm, chronic lymphocytic... more Even if considered a cumulative and not a proliferative CD5+ B-cell neoplasm, chronic lymphocytic leukemia (CLL) has a proliferation rate higher than that recognized earlier, especially in the lymphoid tissues. Some patients with CLL develop a clinical syndrome entitled Richter syndrome (RS). Understanding CLL genetics and epigenetics may help to elucidate the molecular basics of the clinical heterogeneity of this type of malignancy. In the present project we aimed to identify a microRNA species that can predict the evolution of therapy-resistant CLL towards RS. In the first phase of our study, microRNA-19b was identified as a possible target, and in the second phase, we transfected three different CLL cell lines with microRNA-19b mimic and inhibitor and assessed the potential role on leukemia cells in vitro. The mechanism by which miR-19b acts were identified as the upregulation of Ki67 and downregulation of p53. This was further supported through RT-PCR and western blotting on CLL...

Research paper thumbnail of Quantifying Cytosolic Cytochrome c Concentration Using Carbon Quantum Dots as a Powerful Method for Apoptosis Detection

Pharmaceutics

Background: Cytochrome c (Cyt c) is a key biomarker for early apoptosis, and many methods were de... more Background: Cytochrome c (Cyt c) is a key biomarker for early apoptosis, and many methods were designed to detect its release from mitochondria. For a proper evaluation of these programed cell death mechanisms, fluorescent nanoparticles are excellent candidates due to their valuable optical properties. Among all classes of nanoparticles developed thus far, carbon-based quantum dots bring qualitative and efficient imaging strategies for biomedical applications as a consequence of their biocompatibility and low cytotoxicity. Methods: In this study, we synthesized carbon quantum dots smaller than 5 nm from sodium citrate and polyethylene imine. These nanoparticles were rigorously characterized, and their quenching capacity in apoptotic events was assessed in A549 cells treated with staurosporine and etoposide. For the evaluation of Cyt c release, a phenomenon directly correlated with apoptotic events, we ran a semiquantitative analysis using confocal laser scanning microscopy. Results:...

Research paper thumbnail of Correction to: New insights in gene expression alteration as effect of doxorubicin drug resistance in triple negative breast cancer cells

Journal of Experimental & Clinical Cancer Research

An amendment to this paper has been published and can be accessed via the original article.

Research paper thumbnail of New insights in gene expression alteration as effect of doxorubicin drug resistance in triple negative breast cancer cells

Journal of Experimental & Clinical Cancer Research

Background Triple negative breast cancer (TNBC) is a heterogeneous disease with aggressive behavi... more Background Triple negative breast cancer (TNBC) is a heterogeneous disease with aggressive behavior and an unfavorable prognosis rate. Due to the lack of surface receptors, TNBC must be intensely investigated in order to establish a suitable treatment for patients with this pathology. Chemoresistance is an important reason for therapeutic failure in TNBC. Method The aim of this study was to investigate the effect of doxorubicin in TNBC cell lines and to highlight cellular and molecular alterations after a long exposure to doxorubicin. Results The results revealed that doxorubicin significantly increased the half maximal inhibitory concentration (IC50) values at P12 and P24 compared to parenteral cells P0. Modifications in gene expression were investigated through microarray technique, and for detection of mutational pattern was used Next Generation Sequencing (NGS). 196 upregulated and 115 downregulated genes were observed as effect of multiple dose exposure, and 15 overexpressed ge...

Research paper thumbnail of New perspectives in triple-negative breast cancer therapy based on treatments with TGFβ1 siRNA and doxorubicin

Molecular and Cellular Biochemistry

Triple-negative breast cancer (TNBC), which accounts for 10–20% of all breast cancers, has the wo... more Triple-negative breast cancer (TNBC), which accounts for 10–20% of all breast cancers, has the worst prognosis. Although chemotherapy treatment is a standard for TNBC, it lacks a specific target. Therefore, new therapeutic strategies are required to be investigated. In this study, a combined doxorubicin (DOX) and small interfering RNA (siRNA) therapy is proposed as therapeutic strategy for targeting TGFβ1 gene. Hs578T cell line is used as in vitro model for TNBC, wherein TGFβ1siRNA therapy is employed to enhance therapeutic effects. Cell proliferation rate is measured using an MTT test, and morphological alterations are assed using microscopically approached, while gene expression is determined by qRT-PCR analysis. The combined treatment of TGFβ1siRNA and DOX reduced levels of cell proliferation and mitochondrial activity and promoted the alteration of cell morphology (dark-field microscopy). DOX treatment caused downregulation of six genes and upregulation of another six genes. The combined effects of DOX and TGFβ1siRNA resulted in upregulation of 13 genes and downregulation of four genes. Silencing of TGFβ1 resulted in activation of cell death mechanisms in Hs578T cells, to potentiate the effects of DOX, but not in an additive manner, due to the activation of genes involved in resistance to therapy (ABCB1 and IL-6).

Research paper thumbnail of Inhibitory Effect of CAPE and Kaempferol in Colon Cancer Cell Lines—Possible Implications in New Therapeutic Strategies

International Journal of Molecular Sciences, Mar 9, 2019

Background: Phytochemicals are natural compounds synthesized as secondary metabolites in plants a... more Background: Phytochemicals are natural compounds synthesized as secondary metabolites in plants and represent an important source of molecules with therapeutic applications. Attention is accorded to their potential in anti-cancer therapies as single agents or adjuvant treatment. Herby, we evaluated the in vitro effects of a panel of natural compounds with focus on caffeic acid phenethyl ester (CAPE) and Kaempferol for the treatment of human colon cancer. Methods: We exposed two human colon cancer cell lines, RKO and HCT-116, followed by functional examination of cell viability, cell proliferation and invasion, cell cycle, apoptosis, and autophagy. Modifications in gene expression were investigated through microarray and detection of existing mutations and finding of new ones was done with the help of Next Generation Sequencing (NGS). Results: Both CAPE and Kaempferol inhibit cell proliferation, motility and invasion, and stimulate apoptosis and autophagy, concomitant with modifications in coding and noncoding genes' expression. Moreover, there are pathogenic mutations that are no longer found upon treatment with CAPE and Kaempferol. Conclusions: Our findings indicate that CAPE and Kaempferol have the ability to negatively influence the development and advancement of colon cancer in vitro by specifically altering the cells at the molecular level; this activity can be exploited in possible adjuvant therapies once the optimal dose concentration with minimal side effects but with cancer inhibitory activity is set in vivo.

Research paper thumbnail of PEGylated Gold Nanoparticles with Interesting Plasmonic Properties Synthesized Using an Original, Rapid, and Easy-to-Implement Procedure

In this letter, we report a new, one-step, rapid, and easy-to-implement method for the synthesis ... more In this letter, we report a new, one-step, rapid, and easy-to-implement method for the synthesis of PEGylated gold nanoparticles (PEG-AuNPs) having a narrow size distribution and very interesting plasmonic properties. Unmodified polyethylene glycol molecules with a molecular weight of 1000 g/mole (PEG1000) have been employed as reducing and capping agents for the synthesis of spherical gold nanoparticles having an average diameter of 35 nm, within a few minutes. The novelty of the herein proposed synthesis method consists in the fact that the synthesis takes place inside of a sealed bottle flask containing aqueous solutions of PEG1000, tetrachloroauric(III) acid (HAuCl 4), and NaOH, placed in the center of a microwave oven, capable to provide a very uniform temperature environment. It turned out that, during the very short synthesis procedure (2 minutes), PEG 1000 suffers an oxidative transformation in such a manner that its terminal alcohol groups (-CH 2-OH) are transformed in carboxylate ones (-COO −). The as-synthesized PEG-AuNPs possess very interesting plasmonic properties allowing the detection of different molecules by means of SER spectroscopy performed either in liquid droplets or on solid spots. As a consequence of their unique plasmonic properties, the SER spectra acquired using this new class of nanoparticles on different molecules of interest (methylene blue, rhodamine 6G, doxorubicin, and 5-fluorouracil) are highly reproducible, making them ideal candidates for further use as SERS substrates.

Research paper thumbnail of Gold nanorods: from anisotropy to opportunity. An evolution update

Nanomedicine

Gold nanoparticles have drawn attention to nanomedicine for many years due to their physicochemic... more Gold nanoparticles have drawn attention to nanomedicine for many years due to their physicochemical properties, which include: good stability; biocompatibility; easy surface chemistry and superior magnetic; and last, electronic properties. All of these properties distinguish gold nanoparticles as advantageous carriers to be exploited. The challenge to develop new gold nanostructures has led to anisotropy, a new property to exploit for various medical applications: diagnostic and imaging strategies as well as therapeutic options. Gold nanorods are the most studied anisotropic gold nanoparticles because of the presence of two absorption peaks according to their longitudinal and transversal plasmon resonances. The longitudinal surface plasmonic resonance can provide the absorption in the near-infrared region and this is an important aspect of using gold nanorods for medical purposes.

Research paper thumbnail of Inhibitory Effect of CAPE and Kaempferol in Colon Cancer Cell Lines—Possible Implications in New Therapeutic Strategies

International Journal of Molecular Sciences

Background: Phytochemicals are natural compounds synthesized as secondary metabolites in plants a... more Background: Phytochemicals are natural compounds synthesized as secondary metabolites in plants and represent an important source of molecules with therapeutic applications. Attention is accorded to their potential in anti-cancer therapies as single agents or adjuvant treatment. Herby, we evaluated the in vitro effects of a panel of natural compounds with focus on caffeic acid phenethyl ester (CAPE) and Kaempferol for the treatment of human colon cancer. Methods: We exposed two human colon cancer cell lines, RKO and HCT-116, followed by functional examination of cell viability, cell proliferation and invasion, cell cycle, apoptosis, and autophagy. Modifications in gene expression were investigated through microarray and detection of existing mutations and finding of new ones was done with the help of Next Generation Sequencing (NGS). Results: Both CAPE and Kaempferol inhibit cell proliferation, motility and invasion, and stimulate apoptosis and autophagy, concomitant with modificati...

Research paper thumbnail of In vitro study of BSA gel/polyelectrolite complexes core shell microcapsules encapsulating doxorubicin for antitumoral targeted treatment

International Journal of Polymeric Materials and Polymeric Biomaterials

Abstract The aim of this study is to develop core shell microcapsules of bovine serum albumin (BS... more Abstract The aim of this study is to develop core shell microcapsules of bovine serum albumin (BSA) gel with a complex polyelectrolite multilayer shell of natural polysaccharides with opposite charges, pectin (P), chitosan (Chi), and hyaluronic acid (HA) respectively, encapsulating Doxorubicin (Dox) as a carrier for targeted anti-tumoral treatment of hepatic cell carcinoma (HCC). A sacrificial CaCO3 template method was used in order to obtain microcapsules with a BSA gel core and a layer-by-layer (Lbl) deposition technique of polyelectrolite complexes formed between P/Chi in the inner layers and HA/Chi in the outer shell layers. The preformed microcapsules, BSA gel/P/Chi/HA, noted as ms, have been applied for Dox encapsulation (ms-Dox). Dox encapsulation and release in different pH media were studied in order to elucidate the interactions between pH dependently charged species involved in the Dox loading/releasing processes. The structure characterization of ms/ms-Dox was evaluated by FTIR and UV-Vis spectroscopy, X-ray diffraction, thermal analy sis, optical microscopy, confocal laser scanning microscopy, and scanning electron microscopy. The in vitro study for citotoxicity assessment on normal and tumoral cells of both ms and ms-Dox was performed using mesenchymal stem cells (MSCs) and Hep2G HCC cell lines. Results of physical-chemical analyses confirm the successful encapsulation of Dox in ms, and the in vitro biological study recommends ms-Dox as a candidate for future in vivo research as a targeted anti-tumoral treatment modality applications. Graphical Abstract

Research paper thumbnail of Aberrant miRNAs expressed in HER-2 negative breast cancers patient

Journal of Experimental & Clinical Cancer Research

Background: Breast cancer is a highly heterogeneous pathology, exhibiting a number of subtypes co... more Background: Breast cancer is a highly heterogeneous pathology, exhibiting a number of subtypes commonly associated with a poor outcome. Due to their high stability, microRNAs are often regarded as non-invasive cancer biomarkers, having an expression pattern specific for their 'cell of origin'. Method: Triple negative breast cancer (TNBC: ER-, PR-, Her-2-) and double positive breast cancer (DPBC: ER+, PR+, Her-2) miRNA expression patterns were obtained by analysis of the TCGA (The Cancer Genome Atlas) data, followed by PCR-array analysis on plasma samples from 20 TNBC patients, 14 DPBC patients and 11 controls. Results: Three downregulated and nine upregulated miRNAs were obtained from the TNBC analysis. Five overexpressed miRNAs were identified in the DPBC group. Four of the dysregulated miRNAs (miR-10a, miR-125b, miR-210 and miR-489) were common for both groups. The cluster miR-17-92 (miR-17, miR-20a, miR-20b, and miR-93), along with miR-130, miR-22 and miR-29a/c, were found to differentiate between TNBC and DPBC. A panel of five transcripts (miR-10a, miR-125, miR-193b, miR-200b and miR-489) was validated in a new set of plasma samples. The overlapping of TCGA and plasma profiling data revealed miR-200b, miR-200c, miR-210 and miR-29c as common signature. MiR-200b was validated on additional normal and tumor tissue samples. The expression level of this transcript from the TCGA data was correlated with lung and bone metastatic genes. Conclusion: The miR-200b presents a great potential for the future advancements in the diagnostic/prognostic and therapeutic approach of TNBC, along with other coding or non-coding transcripts. However, this needs to be further integrated in a regulatory network that acts in conjunction with other markers that affect the patients' prognosis or response to therapy.

Research paper thumbnail of The silent healer: miR-205-5p up-regulation inhibits epithelial to mesenchymal transition in colon cancer cells by indirectly up-regulating E-cadherin expression

Cell death & disease, Jan 19, 2018

EMT represents the dominant program within advanced stages of colon cancer, where cells acquire m... more EMT represents the dominant program within advanced stages of colon cancer, where cells acquire migratory characteristics in order to invade secondary tissues and form metastasis. Where the majority of the therapeutic strategies are concentrated on the reduction of the tumor mass through different apoptotic mechanisms, the present study advocates an important role for miR-205-5p in impairment of colon cancer cells migration and restoration of the epithelial phenotype. Upon identification of a homogenous downregulated profile for miR-205-5p in colon adenocarcinoma patients, functional studies demonstrated that experimental upregulation of this sequence is able to significantly raise the levels of E-cadherin through direct inhibition of ZEB1. Moreover, the elevation in CDH1 expression was translated into functional parameters where cells lost their invasion and migratory characteristics and formed homogenous clusters through adhesion interactions. Survival analysis of colon adenocarci...

Research paper thumbnail of CHARACTERIZATION OF As2S3 THIN SURFACE FILMS USING SEM AND AFM METHODS

UPB Scientific Bulletin, Series A: Applied Mathematics and Physics

In this paper we report several experimental results concerning the characterization of As2S3 thi... more In this paper we report several experimental results concerning the characterization of As2S3 thin films using scanning electron microscopy (SEM), and atomic force microscopy (AFM). The chalcogenide films were obtained by vacuum thermal deposition. The SEM and AFM analysis of the surfaces emphasized that in the above mentioned thin films, the nanometric structure of the surface is uniform and continuous, without cracks and has a roughness of about 10 nm. From the SEM analysis in fracture of the sample fabricated by the deposition of the As2S3 thin films on glass, we determined their thickness of about 150-160 nm. We highlighted its good adherence to the substrate and the absence of the holes between film and substrate. The investigation of the silver thin (50 nm) films obtained by pulsed laser deposition show the column and island surface topography that may induce light scattering and produce broadening of plasmonic dip. Further development should be done in order to increase surfa...

Research paper thumbnail of Small versus Large Iron Oxide Magnetic Nanoparticles: Hyperthermia and Cell Uptake Properties

Molecules, Oct 13, 2016

Efficient use of magnetic hyperthermia in clinical cancer treatment requires biocompatible magnet... more Efficient use of magnetic hyperthermia in clinical cancer treatment requires biocompatible magnetic nanoparticles (MNPs), with improved heating capabilities. Small (~34 nm) and large (~270 nm) Fe 3 O 4-MNPs were synthesized by means of a polyol method in polyethylene-glycol (PEG) and ethylene-glycol (EG), respectively. They were systematically investigated by means of X-ray diffraction, transmission electron microscopy and vibration sample magnetometry. Hyperthermia measurements showed that Specific Absorption Rate (SAR) dependence on the external alternating magnetic field amplitude (up to 65 kA/m, 355 kHz) presented a sigmoidal shape, with remarkable SAR saturation values of~1400 W/g MNP for the small monocrystalline MNPs and only 400 W/g MNP for the large polycrystalline MNPs, in water. SAR values were slightly reduced in cell culture media, but decreased one order of magnitude in highly viscous PEG1000. Toxicity assays performed on four cell lines revealed almost no toxicity for the small MNPs and a very small level of toxicity for the large MNPs, up to a concentration of 0.2 mg/mL. Cellular uptake experiments revealed that both MNPs penetrated the cells through endocytosis, in a time dependent manner and escaped the endosomes with a faster kinetics for large MNPs. Biodegradation of large MNPs inside cells involved an all-or-nothing mechanism.