15-LOX-1 has diverse roles in the resensitization of resistant cancer cell lines to doxorubicin.

Lipoxygenases (LOXs) are a family of enzymes that can oxygenate polyunsaturated fatty acids. As a member of the family, 15-lipoxygenase-1 (15-LOX-1) specifically metabolizes arachidonic acid and linoleic acid. 15-LOX-1 can affect physiological and pathophysiological events via regulation of the protein-lipid interactome, alterations in intracellular redox state and production of lipid metabolites that are involved in the induction and resolution of inflammation. Although several studies have shown that 15-LOX-1 has an antitumorigenic role in many different cancer models, including breast cancer, the role of the protein in cancer drug resistance has not been established yet. In this study, we, for the first time, aimed to show the potential role of 15-LOX-1 in acquired doxorubicin (DOX) resistance in MCF7 and HeLa cancer cell lines. Our results show that ALOX15 was transcriptionally downregulated in DOX-resistant cells compared with their drug-sensitive counterparts. Moreover, overexpression of ALOX15 in the drug-resistant cells resulted in resensitization of those cells to DOX in a cell-dependent manner. 15-LOX-1 expression could induce apoptosis by activating PPARγ and enhance the accumulation of DOX in drug-resistant MCF7 cells by altering cellular motility properties, and membrane dynamics. However, HeLa DOX cells did not show any of these effects but were susceptible to cell death when treated with 13(S)-HODE. These results underline the role and importance of 15-LOX-1 in cancer drug resistance, and points to novel mechanisms as a therapeutic approach to overcome cancer drug resistance.

Transcriptome analysis of Rhodobacter capsulatus grown on different nitrogen sources.

This study investigated the effect of different nitrogen sources, namely, ammonium chloride and glutamate, on photoheterotrophic metabolism of Rhodobacter capsulatus grown on acetate as the carbon source. Genes that were significantly differentially expressed according to Affymetrix microarray data were categorized into Clusters of Orthologous Groups functional categories and those in acetate assimilation, hydrogen production, and photosynthetic electron transport pathways were analyzed in detail. Genes related to hydrogen production metabolism were significantly downregulated in cultures grown on ammonium chloride when compared to those grown on glutamate. In contrast, photosynthetic electron transport and acetate assimilation pathway genes were upregulated. In detail, aceA encoding isocitrate lyase, a unique enzyme of the glyoxylate cycle and ccrA encoding the rate limiting crotonyl-CoA carboxylase/reductase enzyme of ethylmalonyl-coA pathway were significantly upregulated. Our findings indicate for the first time that R. capsulatus can operate both glyoxylate and ethylmalonyl-coA cycles for acetate assimilation.

Resistance to anticancer drugs permanently alters electrophoretic mobility of cancer cell lines.

Electrophoretic mobility is a physical phenomenon defining the mobility of charged particles in a solution under applied electric field. As charged biological systems, living cells including both prokaryotes and eukaryotes have been assessed in terms of electrophoretic mobility to decipher their electrochemical structure. Moreover, determination of electrophoretic mobility of living cancer cells have promoted the advance exploration of the nature of the cancer cells and separation of cancer cells from normal ones under applied electric field. However, electrophoretic mobility of drug-resistant cells has not yet been examined. In the present study, we determined the electrophoretic mobility of drug-resistant cancer cell lines for both suspension and adherent cells and compared with those of drug-sensitive counterparts. We showed that resistance to anticancer drugs alters the electrophoretic mobility in a permanent manner, even lasting without any exposure to anticancer agents for a long time period. We also studied the cellular morphologies of adherent cells where the cellular invaginations and protrusions were increased in drug-resistant adherent cells, which could be direct cause of altered surface charge and electrophoretic mobility as a result. These findings could be helpful in terms of understanding the electrophysiological and physicochemical background of drug resistance in cancer cells and developing systems to separate drug-sensitive cells from drug-resistant ones.

Iron metabolism and drug resistance in cancer.

Iron is an essential inorganic element for various cellular events. It is directly associated with cell proliferation and growth; therefore, it is expected that iron metabolism is altered in tumor cells which usually have rapid growth rates. The studies on iron metabolism of tumor cells have shown that tumor cells necessitated higher concentrations of iron and the genes of iron uptake proteins were highly over-expressed. However, there are limited number of studies on overall iron metabolism in drug-resistant tumor cells. In this article, we evaluated the studies reporting the relationship between drug resistance and iron metabolism and the utilization of this knowledge for the reversal of drug resistance. Also, the studies on iron-related cell death mechanism, ferroptosis, and its relation to drug resistance were reviewed. We focus on the importance of iron metabolism in drug-resistant cancer cells and how alterations in iron metabolism participate in drug-resistant phenotype.

Single-stage photofermentative biohydrogen production from sugar beet molasses by different purple non-sulfur bacteria.

Biohydrogen production via fermentative routes offers considerable advantages in waste recycling and sustainable energy production. This can be realized by single-stage dark or photofermentative processes, or by a two-stage integrated process; the latter offering the higher production yields due to complete conversion of sugar substrates into H2 and CO2. However, problems arising from the integration of these two processes limit its scale-up and implementation. Hence, high efficiency one-step fermentative biohydrogen production processes from sugar-rich wastes are preferable. In this study, different strains of purple non-sulfur bacteria were investigated for their biohydrogen production capacity on pure sucrose and sugar beet molasses, and the feasibility of single-stage photofermentative biohydrogen production was evaluated. A single-stage photofermentation process was carried out using four different strains of purple non-sulfur bacteria (Rhodobacter capsulatus DSM 1710, R. capsulatus YO3, Rhodobacter sphaeroides O.U.001, and Rhodopseudomonas palustris DSM 127) on different initial sucrose concentrations. The highest hydrogen yield obtained was 10.5 mol H2/mol of sucrose and the maximum hydrogen productivity was 0.78 mmol/L h by Rp. palustris on 5 mM sucrose. A hydrogen yield of 19 mol H2/mol sucrose, which represents 79% of theoretical yield, and a maximum hydrogen productivity of 0.55 mmol/L h were obtained by Rp. palustris from sugar beet molasses. The yield was comparable to those values obtained in two-stage processes. The present study demonstrates that single-stage photofermentation using purple non-sulfur bacteria on sucrose-based wastes is promising.

Long-term biological hydrogen production by agar immobilized Rhodobacter capsulatus in a sequential batch photobioreactor.

In this study, agar immobilization technique was employed for biological hydrogen production using Rhodobacter capsulatus DSM 1710 (wild type) and YO3 (hup-mutant) strains in sequential batch process. Different agar and glutamate concentrations were tested with defined nutrient medium. Agar concentration 4% (w/v) and 4 mM glutamate were selected for bacterial immobilization in terms of rate and longevity of hydrogen production. Acetate concentration was increased from 40 to 60-100 and 60 mM gave best results with both bacterial strains immobilized in 4% (w/v) agar. Cell concentration was increased from 2.5 to 5 mg dcw mL-1 agar and it was found that increasing cell concentration of wild-type strain caused decrease in yield and productivity while these parameters improved by increasing cell concentration of mutant strain. Also, the hydrogen production time has extended from 17 days up to 60 days according to the process conditions and parameters. Hydrogen production by immobilized photosynthetic bacteria is a convenient technology for hydrogen production as it enables to produce hydrogen with high organic acid concentrations comparing to suspended cultures. Besides, immobilization increases the stability of the system and allowed sequential batch operation for long-term application.

Label-free detection of multidrug resistance in K562 cells through isolated 3D-electrode dielectrophoresis.

Dielectrophoresis (DEP), a technique used to separate particles based on different sizes and/or dielectric properties under nonuniform electric field, is a promising method to be applied in label-free, rapid, and effective cell manipulation and separation. In this study, a microelectromechanical systems-based, isolated 3D-electrode DEP device has been designed and implemented for the label-free detection of multidrug resistance in K562 leukemia cells, based on the differences in their cytoplasmic conductivities. Cells were hydrodynamically focused to the 3D-electrode arrays, placed on the side walls of the microchannel, through V-shaped parylene-C obstacles. 3D-electrodes extruded along the z-direction provide uniformly distributed DEP force through channel depth. Cell suspension containing resistant and sensitive cancer cells with 1:100 ratio was continuously flown through the channel at a rate of 10 µL/min. Detection was realized at 48.64 MHz, the cross-over frequency of sensitive K562 cells, at which sensitive cells flow with the fluid, while the resistant ones are trapped by positive DEP force. Device can be operated at considerably low voltages (<9 Vpp ). This is achieved by means of a very thin (0.5 µm) parylene coating on electrodes, providing the advantages offered by the isolation of electrodes from the sample, while the working voltage can still be kept low. Results prove that the presented DEP device can provide an efficient platform for the detection of multidrug resistance in leukemia, in a label-free manner.

Characterization of the distribution of rotational torque on electrorotation chips with 3D electrodes.

This is a study of in-plane and out-of-plane distribution of rotational torque (ROT-T) and effective electric field (EEF) on electrorotation (ER) devices with 3D electrodes using finite element modeling (FEM) and experimental method. The objective of this study is to investigate electrical characteristics of the ER devices with five different electrode geometries and obtain an optimum structure for ER experiments. Further, it provides a comparison between characteristics of the 3D electrodes and traditionally used 2D electrodes. 3D distributions of EEF were studied by the time-variant FEM. FEM results were verified experimentally by studying the rotation of biological cells. The results show that the variations of ROT-T and EEF over the measurement area of the devices are considerably large. This can potentially lead to misinterpretation of recorded data. Therefore, it is essential to specify the boundaries of the measurement area with minimum deviation from the central EEF. For this purpose, FE analyses were utilized to specify the optimal region. Thereby, with confining the measurements to these regions, the dependency of ROT-T on the spatial position of the particles can be eliminated. Comparisons have been made on the sustainability of the EEF and ROT-T distributions for each device, to find an optimum design. Analyses of the devices prove that utilization of the 3D electrodes eliminate irregularities of EEF and ROT-T along the z-axis. The Results show that triangular electrodes provide the highest sustainability for the in-plane ROT-T and EEF distribution, while the oblate elliptical and circular electrodes have the lowest variances along the z-axis.

Protein kinase D2 silencing reduced motility of doxorubicin-resistant MCF7 cells.

Success of chemotherapy is generally impaired by multidrug resistance, intrinsic resistance, or acquired resistance to functionally and structurally irrelevant drugs. Multidrug resistance emerges via distinct mechanisms: increased drug export, decreased drug internalization, dysfunctional apoptotic machinery, increased DNA damage repair, altered cell cycle regulation, and increased drug detoxification. Several reports demonstrated that multidrug resistance is a multifaceted problem such that multidrug resistance correlates with increased aggressiveness and metastatic potential. Here, we tested the involvement of protein kinase D2, a serine/threonine kinase that was previously implicated in proliferation, drug resistance, and motility in doxorubicin-resistant MCF7 (MCF7/DOX) cell line, which served as an in vitro model for drug resistance and invasiveness. We showed that basal level activity of protein kinase D2 (PKD2) was higher in MCF7/DOX cells than parental MCF7 cells. To elucidate the roles of PKD2 MCF7/DOX, PKD2 expression was reduced via small interfering RNA (siRNA)-mediated knockdown. Results showed that acquired resistance of MCF7/DOX to doxorubicin was not affected by PKD2 silencing, while motility of MCF7/DOX cells was reduced. The results implied that PKD2 silencing might inhibit migration of MCF7/DOX cells without affecting chemoresistance significantly.

Association between XRCC3 Thr241Met polymorphism and laryngeal cancer susceptibility in Turkish population.

DNA repair systems are essential for normal cell function. Genetic alterations in the DNA repair genes such as X-ray repair cross-complementing group 3 (XRCC3), can cause a change in protein activity which results in cancer susceptibility. The aim of this study was to investigate the association of XRCC3 Thr241Met single nucleotide polymorphism (SNP), smoking and alcohol consumption with the risk of laryngeal cancer in Turkish population. The frequencies of Thr241Met SNP were studied in 58 laryngeal cancer cases (SSC) and 67 healthy individuals. Genomic DNA was isolated from peripheral blood samples of both controls and laryngeal cancer cases. Thr241Met SNP was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The genotype and allele frequencies of Thr241Met polymorphism were not statistically significant between the laryngeal cancer and control groups. Carrying mutant allele was not associated with the risk of laryngeal cancer. On the other hand, smoking and chronic alcohol consumption were associated with the risk of laryngeal cancer but there is no association between Thr241Met, smoking and alcohol consumption in laryngeal cancer cases. These results indicate that Thr241Met polymorphism was not associated with the development of laryngeal cancer in Turkish population. However, it should be kept in mind that the association of a polymorphism with cancer susceptibility can differ due to several factors such as cancer type, selection criteria, ethnic differences and size of the studied population.

Hydrogen production by hup(-) mutant and wild-type strains of Rhodobacter capsulatus from dark fermentation effluent of sugar beet thick juice in batch and continuous photobioreactors.

Photofermentative production of hydrogen is a promising and sustainable process; however, it should be coupled to dark fermentation to become cost effective. In order to integrate dark fermentation and photofermentation, the suitability of dark fermenter effluents for the photofermentative hydrogen production must be demonstrated. In this study, thermophilic dark fermenter effluent (DFE) of sugar beet thick juice was used as a substrate in photofermentation process to compare wild-type and uptake hydrogenase-deficient (hup (-)) mutant strains of Rhodobacter capsulatus by means of hydrogen production and biomass growth. The tests were conducted in small-scale (50 mL) batch and large-scale (4 L) continuous photobioreactors in indoor conditions under continuous illumination. In small scale batch conditions, maximum cell concentrations were 0.92 gdcw/L c and 1.50 gdcw/L c, hydrogen yields were 34 % and 31 %, hydrogen productivities were 0.49 mmol/(L c·h) and 0.26 mmol/(Lc·h), for hup (-) and wild-type cells, respectively. In large-scale continuous conditions, maximum cell concentrations were 1.44 gdcw/L c and 1.87 gdcw/L c, hydrogen yields were 48 and 46 %, and hydrogen productivities were 1.01 mmol/(L c·h) and 1.05 mmol/(L c·h), for hup (-) and wild-type cells, respectively. Our results showed that Rhodobacter capsulatus hup (-) cells reached to a lower maximum cell concentration but their hydrogen yield and productivity were in the same range or superior compared to the wild-type cells in both batch and continuous operating modes. The maximum biomass concentration, yield and productivity of hydrogen were higher in continuous mode compared to the batch mode with both bacterial strains.

Synthesis of Magnetic Fe3O4-Chitosan Nanoparticles by Ionic Gelation and Their Dye Removal Ability.

The aim of this study was to synthesize magnetic Fe3O4 chitosan nanoparticles (m-Fe3O4-CNs) by ionic gelation method and use them as adsorbent for the removal of Bromothymol Blue (BB) from aqueous solutions. Also, the effect of various parameters on the preparation of m-Fe3O4-CNs was investigated in this study. The nanoparticles were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier transform infrared (FTIR) spectroscopy and vibrating sample magnetometry (VSM). Adsorption of BB on m-Fe3O4-CNs was studied in a batch reactor at different experimental conditions such as adsorbent dosage, pH, contact time, initial BB concentration and temperature. Kinetic behaviors, equilibrium isotherms and thermodynamics of the adsorption process were investigated in detail. The Langmuir adsorption isotherm model and pseudo-second-order kinetic model well fitted the adsorption experimental results. The thermodynamic parameters showed that the adsorption was a spontaneous, favorable and exothermic process in nature.

Transcriptional Profiling of Hydrogen Production Metabolism of Rhodobacter capsulatus under Temperature Stress by Microarray Analysis.

Biohydrogen is a clean and renewable form of hydrogen, which can be produced by photosynthetic bacteria in outdoor large-scale photobioreactors using sunlight. In this study, the transcriptional response of Rhodobacter capsulatus to cold (4 °C) and heat (42 °C) stress was studied using microarrays. Bacteria were grown in 30/2 acetate/glutamate medium at 30 °C for 48 h under continuous illumination. Then, cold and heat stresses were applied for two and six hours. Growth and hydrogen production were impaired under both stress conditions. Microarray chips for R. capsulatus were custom designed by Affymetrix (GeneChip®. TR_RCH2a520699F). The numbers of significantly changed genes were 328 and 293 out of 3685 genes under cold and heat stress, respectively. Our results indicate that temperature stress greatly affects the hydrogen production metabolisms of R. capsulatus. Specifically, the expression of genes that participate in nitrogen metabolism, photosynthesis and the electron transport system were induced by cold stress, while decreased by heat stress. Heat stress also resulted in down regulation of genes related to cell envelope, transporter and binding proteins. Transcriptome analysis and physiological results were consistent with each other. The results presented here may aid clarification of the genetic mechanisms for hydrogen production in purple non-sulfur (PNS) bacteria under temperature stress.

Detection of XRCC1 gene polymorphisms in Turkish head and neck squamous cell carcinoma patients: a comparative analysis with different populations.

PURPOSE: X-ray repair cross-complementing (XRCC1) is one of the most important genes for the maintenance of genomic integrity and protection of cells from DNA damage. Although tobacco and alcohol consumption are the major risk factors for the development of head and neck squamous cell carcinoma (HNSCC), sequence variation in XRCC1 gene may alter HNSCC susceptibility. Reports on the relationship between HNSCC and polymorphisms in XRCC1 gene have been inconsistent so far. The aim of this study was to investigate the association of XRCC1 Arg194Trp and Arg399Gln single nucleotide polymorphisms (SNP), smoking and alcohol consumption with the risk of HNSCC in Turkish population and also to compare to these results with the ones from both Turkish and different populations in the literature. The frequencies of Arg194Trp and Arg399Gln SNPs were studied in 55 HNSCC and 69 healthy individuals. METHODS: Genomic DNA was isolated from peripheral blood and SNP was genotyped by PCR-RFLP method. RESULTS: The genotype and allele frequencies of both polymorphisms were not statistically different between the HNSCC and control groups. On the other hand, smoking and chronic alcohol consumption were associated with risk of HNSCC, but there was no association between Arg194Trp, Arg399Gln polymorphisms, smoking and alcohol consumption in HNSCC cases. CONCLUSION: These results indicate that both Arg194Trp and Arg399Gln polymorphisms were not associated with the development of HNSCC in Turkish population. In addition, the allele frequencies of polymorphisms were in line with other Turkish population results that were studied previously. However, compared to different populations, there were marked differences in allele frequencies.

Polyhydroxybutyrate-coated magnetic nanoparticles for doxorubicin delivery: cytotoxic effect against doxorubicin-resistant breast cancer cell line.

In this study, polyhydroxybutyrate (PHB)-coated magnetic nanoparticles (MNPs) were prepared by coprecipitation of iron salts (Fe and Fe) by ammonium hydroxide. Characterizations of PHB-coated MNPs were performed by Fourier transform infrared spectroscopy, x-ray diffraction, dynamic light scattering, thermal gravimetric analysis, vibrating sample magnetometry, and transmission electron microscopy analyses. Doxorubicin was loaded onto PHB-MNPs, and the release efficiencies at different pHs were studied under in vitro conditions. The most efficient drug loading concentration was found about 87% at room temperature in phosphate-buffered saline (pH 7.2). The drug-loaded MNPs were stable up to 2 months in neutral pH for mimicking physiological conditions. The drug release studies were performed with acetate buffer (pH 4.5) that mimics endosomal pH. Doxorubicin (60%) released from PHB-MNPs within 65 hours. Doxorubicin-loaded PHB-MNPs were about 2.5-fold more cytotoxic as compared with free drug on resistant Michigan Cancer Foundation-7 (human breast adenocarcinoma, MCF-7) cell line (1 µM doxorubicin) in vitro. Therefore, doxorubicin-loaded PHB-MNPs lead to overcome the drug resistance.

Different types of cell cycle- and apoptosis-related gene expressions alter in corticosteroid-, vincristine-, and melphalan-resistant u-266 multiple myeloma cell lines.

OBJECTIVE: Hemophilia B is caused by coagulation defects in the factor IX gene located in Xq27.1 on the X chromosome. A wide range of mutations, showing extensive molecular heterogeneity, have been described in hemophilia B patients. Our study was aimed at genetic analysis and prenatal diagnosis of hemophilia B in order to further elucidate the pathogenesis of the hemophilia B pedigree in China. MATERIALS AND METHODS: Polymerase chain reaction amplification and direct sequencing of all the coding regions was conducted in hemophilia B patients and carriers. Prenatal diagnosis of the proband was conducted at 20 weeks. RESULTS: We identified the novel point mutation 10.389 A>G, located upstream of the intron 3 acceptor site in hemophilia B patients. The fetus of the proband's cousin was identified as a carrier. CONCLUSION: Our identification of a novel mutation in the F9 gene associated with hemophilia B provides novel insight into the pathogenesis of this genetically inherited disorder and also represents the basis of prenatal diagnosis.

Differential synergistic effects of palbociclib and doxorubicin on doxorubicin-resistant cancer cells with diverse tumor origins.

Palbociclib is a dual inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6). Palbociclib has frequently been studied in breast cancer cells and has also been linked to function of P-glycoprotein (P-gp), main protein responsible for cancer drug resistance. However, the effect of Palbociclib on cancer drug resistance and specifically doxorubicin-resistant cells overexpressing P-gp have limitedly been studied in the literature. Here, we aimed to decipher the possible synergistic effects of Palbociclib and Doxorubicin combination treatment in doxorubicin-resistant not only breast cancer, which has restrictedly been studied previously, but leukemia and cervical cancer cell lines in the presence of sensitive counterparts to totally explore the mechanistic properties of the Palbociclib in cancer drug resistance. Our results underlined that Palbociclib differentially displayed synergistic effect with doxorubicin in a cell type-specific manner and increased the efficacy of Doxorubicin in Doxorubicin-resistant cells. As a monotherapy, palbociclib has been shown to decrease the expression of MDR-1 in doxorubicin-resistant cells, and when used in combination with doxorubicin, it has been shown to increase the accumulation of doxorubicin in the cell and consequently induce apoptosis. This is the first report that proposes the Palbociclib as a candidate for combination therapy to limit the Doxorubicin resistance in different cancer origins in clinics.

Preparation and evaluation of polymer based microcarriers for all-trans-retinoic acid.

Polymeric biomaterials are being investigated for the last several years because of their controllable properties. In this study, it was aimed to prepare and evaluate the atRA carrying system using Poly(lactide-co-glycolide) (PLGA). Microparticles were characterized in terms of morphology and encapsulation efficiency. Release studies were performed for the evaluation of drug release rates. Cytotoxicity tests were implemented on MCF-7 Human breast cancer cell line for the investigation of drug and polymer toxicity. The microparticles were found smooth and spherical in shape. However, as the loaded drug amount increased, the sizes of microparticles also increased and the size distribution became less uniform. The sizes of atRA-loaded microparticles ranged between 1-10 µm. The encapsulation efficiency of atRetinoic acid (all-trans-Retinoic acid) was achieved approximately %90. Approximately, 45% of atRA was released from atRA-loaded microparticles by the end of 4-5 days. Cell growth inhibition was observed after 4 days of incubation of cells with PLGA microparticles.

Investigation of the Therapeutic Effects of Palbociclib Conjugated Magnetic Nanoparticles on Different Types of Breast Cancer Cell Lines.

Introduction: Drug targeting and controlled drug release systems in cancer treatment have many advantages over conventional chemotherapy in terms of limiting systemic toxicity, side effects, and overcoming drug resistance. Methods and Results: In this paper, fabricating nanoscale delivery system composed of magnetic nanoparticles (MNPs) covered with poly-amidoamine (PAMAM) dendrimers and using its advantages were fully used to help the chemotherapeutic drug, Palbociclib, effectively reach tumors, specifically and stay stable in the circulation longer. In order to determine whether conjugate selectivity can be increased for the specific drug type, we have reported different strategies for loading and conjugation of Palbociclib to different generations of magnetic PAMAM dendrimers. The best method leading to the highest amount of Palbociclib conjugation was chosen, and the characterization of the Palbociclib conjugated dendrimeric magnetic nanoparticles (PAL-DcMNPs) were performed. In vitro pharmacological activity of the conjugation was demonstrated by measuring the cell viability and lactate dehydrogenase (LHD) release. Obtained results indicated that PAL-DcMNPs treatment of the breast cancer cell lines, leads to an increase in cell toxicity compared to free Palbociclib. The observed effects were more evident for MCF-7 cells than for MDA-MB231 and SKBR3 cells, considering that viability decreased to 30% at 2.5 µM treatment of PAL-DcMNPs at MCF-7 cells. Finally, in Palbociclib and PAL-DcMNPs treated breast cancer cells, the expression levels of some pro-apoptotic and drug resistance related genes were performed by RT-PCR analysis. Conclusion: Our knowledge indicates that the proposed approach is novel, and it can provide new insight into the development of Palbociclib targeting delivery system for cancer treatment.

Two different docetaxel resistant MCF-7 sublines exhibited different gene expression pattern.

The objective of the present study was to investigate gene expression pattern of two docetaxel resistant MCF-7 breast carcinoma sublines step wisely selected in 30 and 120 nM docetaxel. Cell proliferation assay was performed in order to demonstrate development of docetaxel resistance. cDNA microarray analysis was performed using Affymetrix(®) Human Genome U133 Plus 2.0 Arrays in duplicate experiments. Quantitative and semi-quantitative gene expression analysis was also performed to confirm gene expression analysis for selected genes. XTT results demonstrated that 30 (MCF-7/30nM DOC) and 120 nM (MCF-7/120nM DOC) docetaxel selected cells were 13- and 47-fold resistant, respectively. cDNA microarray analysis demonstrated that expression profiles of MCF-7 and MCF-7/30nM DOC were more similar to each other where expression profile of MCF-7/120nM DOC was different as examined by line graphs and scatter plots. 2,837 and 4,036 genes were significantly altered in 30 and 120 nM docetaxel resistant sublines, respectively. Among these, 849 genes were altered in common in two docetaxel resistant sublines. Antiapoptotic gene expression (e.g., Bcl-2 and APRIL) were noticeably altered in MCF-7/30nM DOC. However, docetaxel resistance in MCF-7/120nM DOC were more complicated with the involvement of ECM related gene expression, cytokine and growth factor signaling, ROS metabolism and EMT related gene expression together with higher level of MDR1 expression. Expression profiles in 30 and 120 nM docetaxel resistant sublines changed gradually with increasing resistance index. Drug resistance development seems to be step wise event in MCF-7 cells.