Analyzing Blood Cells of High-Risk Myelodysplastic Syndrome Patients Using Interferometric Phase Microscopy and Fluorescent Flow Cytometry

Myelodysplastic syndromes (MDSs) are a group of potentially deadly diseases that affect the morphology and function of neutrophils. Rapid diagnosis of MDS is crucial for the initiation of treatment that can vastly improve disease outcome. In this work, we present a new approach for detecting morphological differences between neutrophils isolated from blood samples of high-risk MDS patients and blood bank donors (BBDs). Using fluorescent flow cytometry, neutrophils were stained with 2',7'-dichlorofluorescin diacetate (DCF), which reacts with reactive oxygen species (ROS), and Hoechst, which binds to DNA. We observed that BBDs possessed two cell clusters (designated H and L), whereas MDS patients possessed a single cluster (L). Later, we used FACS to sort the H and the L cells and used interferometric phase microscopy (IPM) to image the cells without utilizing cell staining. IPM images showed that H cells are characterized by low optical path delay (OPD) in the nucleus relative to the cytoplasm, especially in cell vesicles containing ROS, whereas L cells are characterized by low OPD in the cytoplasm relative to the nucleus and no ROS-containing vesicles. Moreover, L cells present a higher average OPD and dry mass compared to H cells. When examining neutrophils from MDS patients and BBDs by IPM during flow, we identified ~20% of cells as H cells in BBDs in contrast to ~4% in MDS patients. These results indicate that IPM can be utilized for the diagnosis of complex hematological pathologies such as MDS.

On-chip label-free cell classification based directly on off-axis holograms and spatial-frequency-invariant deep learning

We present a rapid label-free imaging flow cytometry and cell classification approach based directly on raw digital holograms. Off-axis holography enables real-time acquisition of cells during rapid flow. However, classification of the cells typically requires reconstruction of their quantitative phase profiles, which is time-consuming. Here, we present a new approach for label-free classification of individual cells based directly on the raw off-axis holographic images, each of which contains the complete complex wavefront (amplitude and quantitative phase profiles) of the cell. To obtain this, we built a convolutional neural network, which is invariant to the spatial frequencies and directions of the interference fringes of the off-axis holograms. We demonstrate the effectiveness of this approach using four types of cancer cells. This approach has the potential to significantly improve both speed and robustness of imaging flow cytometry, enabling real-time label-free classification of individual cells.

Sperm Inspection for In Vitro Fertilization via Self-Assembled Microdroplet Formation and Quantitative Phase Microscopy

We present a new method for the selection of individual sperm cells using a microfluidic device that automatically traps each cell in a separate microdroplet that then individually self-assembles with other microdroplets, permitting the controlled measurement of the cells using quantitative phase microscopy. Following cell trapping and droplet formation, we utilize quantitative phase microscopy integrated with bright-field imaging for individual sperm morphology and motility inspection. We then perform individual sperm selection using a single-cell micromanipulator, which is enhanced by the microdroplet-trapping procedure described above. This method can improve sperm selection for intracytoplasmic sperm injection, a common type of in vitro fertilization procedure.

Real-Time Stain-Free Classification of Cancer Cells and Blood Cells Using Interferometric Phase Microscopy and Machine Learning

We present a method for real-time visualization and automatic processing for detection and classification of untreated cancer cells in blood during stain-free imaging flow cytometry using digital holographic microscopy and machine learning in throughput of 15 cells per second. As a preliminary model for circulating tumor cells in the blood, following an initial label-free rapid enrichment stage based on the cell size, we applied our holographic imaging approach, providing the quantitative optical thickness profiles of the cells during flow. We automatically classified primary and metastatic colon cancer cells, where the two types of cancer cells were isolated from the same individual, as well as four types of blood cells. We used low-coherence off-axis interferometric phase microscopy and a microfluidic channel to image cells during flow quantitatively. The acquired images were processed and classified based on their morphology and quantitative phase features during the cell flow. We achieved high accuracy of 92.56% for distinguishing between the cells, enabling further automatic enrichment and cancer-cell grading from blood. © 2020 International Society for Advancement of Cytometry.

Limited-angle tomographic phase microscopy utilizing confocal scanning fluorescence microscopy

We present a multimodal imaging technique, combining tomographic phase microscopy with limited angular projection range and number, and two-channel spinning-disk confocal scanning fluorescence microscopy. This technique allows high-accuracy 3D refractive index (RI) profiling of live cells in spite of the missing projections. The cellular outer shape and its interior organelles measured by the confocal fluorescence imaging not only specify the cell in molecular levels, but also provide the 3D distributions of the whole cell as well as its organelles. We take these additional 3D morphological details as constraints in Gerchberg-Papoulis-based optical diffraction tomography algorithm. We then obtain an accurate 3D RI tomogram, even with a sparse angular range having a small number of perspective projections, otherwise providing low-accuracy RI reconstruction. Then, we obtain both cellular molecular specificity and inner RI values of the cell and its organelles. We compare the reconstructed 3D RI profiles of various samples, demonstrating the superiority of the proposed technique.

Label-free discrimination and selection of cancer cells from blood during flow using holography-induced dielectrophoresis

We present a method for label-free imaging and sorting of cancer cells in blood, which is based on a dielectrophoretic microfluidic chip and label-free interferometric phase microscopy. The chip used for imaging has been embedded with dielectrophoretic electrodes, and therefore it can be used to sort the cells based on the decisions obtained during the cell flow by the label-free quantitative imaging method. Hence, we obtained a real-time, automatic, label-free imaging flow cytometry with the ability to sort the cells during flow. To validate our model, we combined into the label-free imaging interferometer a fluorescence imaging channel that indicated the correctness of the label-free sorting. We have achieved above 98% classification success and 69% sorting accuracy at flow rates of 4 to 7 μL hr^-1 . In the future, this method is expected to help in label-free sorting of circulating tumor cells in blood following an initial state-of-the-art cell enrichment.

Real-Time Stain-Free Classification of Cancer Cells and Blood Cells Using Interferometric Phase Microscopy and Machine Learning

We present a method for real-time visualization and automatic processing for detection and classification of untreated cancer cells in blood during stain-free imaging flow cytometry using digital holographic microscopy and machine learning in throughput of 15 cells per second. As a preliminary model for circulating tumor cells in the blood, following an initial label-free rapid enrichment stage based on the cell size, we applied our holographic imaging approach, providing the quantitative optical thickness profiles of the cells during flow. We automatically classified primary and metastatic colon cancer cells, where the two types of cancer cells were isolated from the same individual, as well as four types of blood cells. We used low-coherence off-axis interferometric phase microscopy and a microfluidic channel to image cells during flow quantitatively. The acquired images were processed and classified based on their morphology and quantitative phase features during the cell flow. We achieved high accuracy of 92.56% for distinguishing between the cells, enabling further automatic enrichment and cancer-cell grading from blood. © 2020 International Society for Advancement of Cytometry.

Cell and nucleus refractive-index mapping by interferometric phase microscopy and rapid confocal fluorescence microscopy

We present a multimodal technique for measuring the integral refractive index and the thickness of biological cells and their organelles by integrating interferometric phase microscopy (IPM) and rapid confocal fluorescence microscopy. First, the actual thickness maps of the cellular compartments are reconstructed using the confocal fluorescent sections, and then the optical path difference (OPD) map of the same cell is reconstructed using IPM. Based on the co-registered data, the integral refractive index maps of the cell and its organelles are calculated. This technique enables rapidly measuring refractive index of live, dynamic cells, where IPM provides quantitative imaging capabilities and confocal fluorescence microscopy provides molecular specificity of the cell organelles. We acquire human colorectal adenocarcinoma cells and show that the integral refractive index values are similar for the whole cell, the cytoplasm and the nucleus on the population level, but significantly different on the single cell level.

High-resolution 4-D acquisition of freely swimming human sperm cells without staining

We present a new acquisition method that enables high-resolution, fine-detail full reconstruction of the three-dimensional movement and structure of individual human sperm cells swimming freely. We achieve both retrieval of the three-dimensional refractive-index profile of the sperm head, revealing its fine internal organelles and time-varying orientation, and the detailed four-dimensional localization of the thin, highly-dynamic flagellum of the sperm cell. Live human sperm cells were acquired during free swim using a high-speed off-axis holographic system that does not require any moving elements or cell staining. The reconstruction is based solely on the natural movement of the sperm cell and a novel set of algorithms, enabling the detailed four-dimensional recovery. Using this refractive-index imaging approach, we believe that we have detected an area in the cell that is attributed to the centriole. This method has great potential for both biological assays and clinical use of intact sperm cells.

Quantitative phase imaging by wide-field interferometry with variable shearing distance uncoupled from the off-axis angle

We introduce a new shearing interferometry module for digital holographic microscopy, in which the off-axis angle, which defines the interference fringe frequency, is not coupled to the shearing distance, as is the case in most shearing interferometers. Thus, it enables the selection of shearing distance based on the spatial density of the sample, without losing spatial frequency content due to overlapping of the complex wave fronts in the spatial frequency domain. Our module is based on a 4f imaging unit and a diffraction grating, in which the hologram is generated from two mutually coherent, partially overlapping sample beams, with adjustable shearing distance, as defined by the position of the grating, but with a constant off-axis angle, as defined by the grating period. The module is simple, easy to align, and presents a nearly common-path geometry. By placing this module as an add-on unit at the exit port of an inverted microscope, quantitative phase imaging can easily be performed. The system is characterized by a 2.5 nm temporal stability and a 3.4 nm spatial stability, without using anti-vibration techniques. We provide quantitative phase imaging experiments of silica beads with different shearing distances, red blood cell fluctuations, and cancer cells flowing in a micro-channel, which demonstrate the capability and versatility of our approach in different imaging scenarios.

Stain-free interferometric phase microscopy correlation with DNA fragmentation stain in human spermatozoa

Acridine orange (AO) staining is used to diagnose DNA fragmentation status in sperm cells. Interferometric phase microscopy (IPM) is an optical imaging method based on digital holographic microscopy that provides quantitative morphological and refractive index imaging of cells in vitro without the need for staining. We have imaged sperm cells using stain-free IPM in order to estimate different cellular parameters, such as acrosome dry mass and size, in addition to an embryologist evaluation according to the World Health Organization (WHO)-2010 criteria. Following this, the same sperm cells were stained by AO, imaged using a fluorescence confocal microscope and assessed by the AO-emitted color, forming five DNA fragmentation groups. These DNA fragmentation groups were correlated with the embryologist-based classification and the IPM-based morphological parameters. Our results indicate on significant differences in the IPM-based parameters between groups with different fragmentation levels. Based on the validation with AO, we conclude that stain-free IPM images analyzed digitally may assist in selecting sperm cells with intact DNA prior to intracytoplasmic sperm injection. This information may potentially increase percentage of successful pregnancies.

Simultaneous off-axis multiplexed holography and regular fluorescence microscopy of biological cells

We present a new technique for obtaining simultaneous multimodal quantitative phase and fluorescence microscopy of biological cells, providing both quantitative phase imaging and molecular specificity using a single camera. Our system is based on an interferometric multiplexing module, externally positioned at the exit of an optical microscope. In contrast to previous approaches, the presented technique allows conventional fluorescence imaging, rather than interferometric off-axis fluorescence imaging. We demonstrate the presented technique for imaging fluorescent beads and live biological cells.

Simultaneous three-wavelength unwrapping using external digital holographic multiplexing module

We present an external interferometric setup that is able to simultaneously acquire three wavelengths of the same sample instance without scanning or multiple exposures. This setup projects onto the monochrome digital camera three off-axis holograms with rotated fringe orientations, each from a different wavelength channel, without overlap in the spatial-frequency domain, and thus allows the full reconstruction of the three complex wavefronts from the three wavelength channels. We use this new setup for three-wavelength phase unwrapping, allowing phase imaging of thicker objects than possible with a single wavelength, but without the increased level of noise. We demonstrate the proposed technique for micro-channel profiling and label-free cell imaging.

Integral refractive index imaging of flowing cell nuclei using quantitative phase microscopy combined with fluorescence microscopy

We suggest a new multimodal imaging technique for quantitatively measuring the integral (thickness-average) refractive index of the nuclei of live biological cells in suspension. For this aim, we combined quantitative phase microscopy with simultaneous 2-D fluorescence microscopy. We used 2-D fluorescence microscopy to localize the nucleus inside the quantitative phase map of the cell, as well as for measuring the nucleus radii. As verified offline by both 3-D confocal fluorescence microscopy and 2-D fluorescence microscopy while rotating the cells during flow, the nucleus of cells in suspension that are not during division can be assumed to be an ellipsoid. The entire shape of a cell in suspension can be assumed to be a sphere. Then, the cell and nucleus 3-D shapes can be evaluated based on their in-plain radii available from the 2-D phase and fluorescent measurements, respectively. Finally, the nucleus integral refractive index profile is calculated. We demonstrate the new technique on cancer cells, obtaining nucleus refractive index values that are lower than those of the cytoplasm, coinciding with recent findings. We believe that the proposed technique has the potential to be used for flow cytometry, where full 3-D refractive index tomography is too slow to be implemented during flow.

Localized measurements of physical parameters within human sperm cells obtained with wide-field interferometry

We developed a new method to identify the separate cellular compartments in the optical path delay (OPD) maps of un-labeled spermatozoa. This was conducted by comparing OPD maps of fixed, un-labeled spermatozoa to bright field images of the same cells following labeling. The labeling enabled us to identify the acrosomal and nuclear compartments in the corresponding OPD maps of the cells. We then extracted the refractive index maps of fixed cells by dividing the OPD maps of spermatozoa by the corresponding thickness maps of the same cells, obtained with AFM. Finally, the dry mass of the head, nucleus and acrosome of un-labeled immobile spermatozoa, was measured. This method provides the ability to quantitatively measure the dry mass of cellular compartments within human spermatozoa. We expect that these measurements will assist label-free selection of sperm cells for fertilization.

Rapid 3D Refractive-Index Imaging of Live Cells in Suspension without Labeling Using Dielectrophoretic Cell Rotation

A major challenge in the field of optical imaging of live cells is achieving rapid, 3D, and noninvasive imaging of isolated cells without labeling. If successful, many clinical procedures involving analysis and sorting of cells drawn from body fluids, including blood, can be significantly improved. A new label-free tomographic interferometry approach is presented. This approach provides rapid capturing of the 3D refractive-index distribution of single cells in suspension. The cells flow in a microfluidic channel, are trapped, and then rapidly rotated by dielectrophoretic forces in a noninvasive and precise manner. Interferometric projections of the rotated cell are acquired and processed into the cellular 3D refractive-index map. Uniquely, this approach provides full (360°) coverage of the rotation angular range around any axis, and knowledge on the viewing angle. The experimental demonstrations presented include 3D, label-free imaging of cancer cells and three types of white blood cells. This approach is expected to be useful for label-free cell sorting, as well as for detection and monitoring of pathological conditions resulting in cellular morphology changes or occurrence of specific cell types in blood or other body fluids.

Evaluation of the ornithogenic influence on the trophic state of East Mediterranean wetland ecosystem using trend analysis

The Great Rift Valley portion of the East African-Eurasian Migratory Flyway is extremely important globally because of the numbers (>500 million) and diversity of seasonal traveling birds. The construction of the Agmon wetland (1.1km(2)) in the Hula Valley, Israel in 1994 and a change in crop type and rotation has attracted increasing number of Eurasian cranes (Grus grus) to winter in the wetland (>40,000 in 2014). The birds are fed in an area of 100ha and roost during the night in the wetland for protection from predators. Feeding practices have yielded an eco-tourism bonanza with over 400,000 visitors annually. However, this practice may have negative impacts on the trophic state of the wetland. We performed trend analyses using monthly means of selected constituents collected from mid-1994 to 2014. The temporal distribution of TN and TP concentrations in the inlets did not change with time. The concentrations of TN and TP in the outlet increased significantly during the earlier monitoring period. Kendall-Theil regression showed that TP concentrations in the outlet increased significantly from a monthly mean of 180μgL(-1) in 2010 to a monthly mean of 260μgL(-1) in 2014. Similarly, the results of chlorophyll a concentrations in the outlet showed a sharp upturn in the latter part of the series from a mean of 66mgL(-1) in 2010 to a mean of 122mgL(-1) in 2014. The concurrent increase of TP and chlorophyll a, the two most important parameters affecting a waterbody trophic index coincided with the observed increase in the number of roosting cranes in the wetland. Hence, we assume that the continued increases in TP concentrations could transform the wetland from a mild eutrophic to a permanent hypereutrophic state. Reducing the number of roosting cranes may prevent this from happening.

Detection and controlled depletion of cancer cells using photothermal phase microscopy

We present a dual-modality technique based on wide-field photothermal (PT) interferometric phase imaging and simultaneous PT ablation to selectively deplete specific cell populations labelled by plasmonic nanoparticles. This combined technique utilizes the plasmonic reaction of gold nanoparticles under optical excitation to produce PT imaging contrast by inducing local phase changes when the excitation power is weak, or ablation of selected cells when increasing the excitation power. Controlling the entire process is carried out by dynamic quantitative phase imaging of all cells (labelled and unlabelled). We demonstrate our ability to detect and specifically ablate in vitro cancer cells over-expressing epidermal growth factor receptors (EGFRs), labelled with plasmonic nanoparticles, in the presence of either EGFR under-expressing cancer cells or white blood cells. The latter demonstration establishes an initial model for depletion of circulating tumour cells in blood. The proposed system is able to image in wide field the label-free quantitative phase profile together with the PT phase profile of the sample, and provides the ability of both detection and selective cell ablation in a controlled environment. Quantitative phase imaging with molecular specificity and specific cell depletion. (a) Label-free quantitative phase profiles of mixed population of EGFR(+) /EGFR(-) cancer cells. (b) When weak modulated PT excitation is applied, selective phase contrast is generated in the modulation frequency only for the EGFR(+) cancer cells labelled with plasmonic nanoparticles. (c) When stronger modulated PT excitation is applied, selective ablation of the EGFR(+) cancer cells labelled with plasmonic nanoparticles occurs. White scalebars represent 10 µm upon sample.

Targeting ErbB-1 and ErbB-4 in irradiated head and neck cancer: results of in vitro and in vivo studies

BACKGROUND

ErbB oncogenes have a major role in cancer. The role of ErbB-4 in cancer cell biology and the effect of anti-ErbB-1 and anti-ErbB-4 monoclonal antibodies were evaluated in this study.

METHODS

ErbB-4 expression and binding was evaluated by Western blot, enzyme-linked immunosorbent assay (ELISA), fluorescent microscopy, and flow cytometry. Cell survival was measured by XTT assay. Tumor progression was followed up in nude mice model.

RESULTS

High ErbB-1 levels in head and neck cancer cell lines were determined, whereas ErbB-4 expression varied. Specific antibody binding to the cells was demonstrated. High ErbB-4 expressing squamous cell carcinoma 1 (SCC-1) cells proliferated faster and generated faster growing tumors in mice. Cetuximab and mAb-3 reduced cell survival proportional to ErbB-1 and ErbB-4 expression. Combination of antibodies with irradiation was most effective in reducing cell survival and tumor growth.

CONCLUSION

ErbB-4 plays a role in head and neck cancer cell biology. Anti-ErbB-4 targeted therapy can serve as a new strategy against head and neck cancer when combined with established treatments.

The chemokine CCL5 as a potential prognostic factor predicting disease progression in stage II breast cancer patients

PURPOSE

The aim of this study was to determine the prognostic value of the chemokine CCL5, considered as a promalignancy factor in breast cancer, in predicting breast cancer progression and to evaluate its ability to strengthen the prognostic significance of other biomarkers.

EXPERIMENTAL DESIGN

The expression of CCL5, alone and in conjunction with estrogen receptor (ER)-alpha, ER-beta, progesterone receptor (PR), and HER-2/neu (ErbB2), was determined in breast tumor cells by immunohistochemistry. The study included 142 breast cancer patients, including individuals in whom disease has progressed.

RESULTS

Using Cox proportional hazard models, univariate analysis suggested that, in stage I breast cancer patients, CCL5 was not a significant predictor of disease progression. In contrast, in stage II patients, the expression of CCL5 (CCL5(+)), the absence of ER-alpha (ER-alpha(-)), and the lack of PR expression (PR(-)) increased significantly the risk for disease progression (P = 0.0045, 0.0041, and 0.0107, respectively). The prognostic strength of CCL5, as well as of ER-alpha(-), improved by combining them together (CCL5(+)/ER-alpha(-): P = 0.0001), being highly evident in the stage IIA subgroup [CCL5(+)/ER-alpha(-) (P = 0.0003); ER-alpha(-) (P = 0.0315)]. In the stage II group as a whole, the combinations of CCL5(-)/ER-alpha(+) and CCL5(-)/PR(+) were highly correlated with an improved prognosis. Multivariate analysis indicated that, in stage II patients, ER-alpha and CCL5 were independent predictors of disease progression.

CONCLUSIONS

CCL5 could be considered as a biomarker for disease progression in stage II breast cancer patients, with the CCL5(+)/ER-alpha(-) combination providing improved prediction of disease progression, primarily in the stage IIA subgroup.

ErbB-4 may control behavior of prostate cancer cells and serve as a target for molecular therapy

PURPOSE

To assess ErbB-4 expression in advanced human prostate cancer (PC) cell lines, the role of ErbB-4 in motility, migration, and proliferative/tumorigenic potential of PC cells, and efficacy of anti-ErbB-4 monoclonal antibody (Mab) treatment on PC cells in vitro and tumor growth in vivo.

MATERIALS AND METHODS

Established advanced human PC cell lines (PC-3, Cl-1, and Du-145) were evaluated for ErbB-4 expression. Several Cl-1 cell line clones expressing various levels of ErbB-4 were isolated, their motility, migration capacity, and in vitro proliferation as well as survival following Mab treatment were evaluated. Tumorigenicity and proliferation capacity of these clones in vivo and efficacy of Mab treatment on tumor growth were estimated by measurements of subcutaneous tumors developed in nude mice.

RESULTS

PC cell lines studied express ErbB-4. Both PC-3 and Du-145 cell lines express high ErbB-4 levels; only 50% of Cl-1 cells express ErbB-4 with large heterogeneity. Cl-1 sub-clones highly expressing ErbB-4 showed increased cell motility, migration, and proliferation rate in vitro and enhanced growth in vivo, compared to clones with low ErbB-4 expression. Mab treatment inhibited the growth of cells expressing high but not low ErbB-4 levels in vitro and decreased the growth of subcutaneous tumors in nude mice generated by ErbB-4 highly expressing cells.

CONCLUSIONS

High expression of ErbB-4 in prostate cancer Cl-1 cell clones correlated with high proliferative and migration capacity and high tumorigenic potential. The inhibitory effect of Mab on cell proliferation and on subcutaneous tumor growth suggests ErbB-4's potential as a target for molecular anticancer therapy.

Antibody internalization studied using a novel IgG binding toxin fusion

Targeted therapy encompasses a wide variety of different strategies, which can be divided into direct or indirect approaches. Direct approaches target tumor-associated antigens by monoclonal antibodies (mAbs) binding to the relevant antigens or by small-molecule drugs that interfere with these proteins. Indirect approaches rely on tumor-associated antigens expressed on the cell surface with antibody-drug conjugates or antibody-based fusion proteins containing different kinds of effector molecules. To deliver a lethal cargo into tumor cells, the targeting antibodies should efficiently internalize into the cells. Similarly, to qualify as targets for such drugs newly-discovered cell-surface molecules should facilitate the internalization of antibodies that bind to them. Internalization can be studied be several biochemical and microscopy approaches. An undisputed proof of internalization can be provided by the ability of an antibody to specifically deliver a drug into the target cells and kill it. We present a novel IgG binding toxin fusion, ZZ-PE38, in which the Fc-binding ZZ domain, derived from Streptococcal protein A, is linked to a truncated Pseudomonas exotoxin A, the preparation of complexes between ZZ-PE38 and IgGs that bind tumor cells and the specific cytotoxicity of such immunocomplexes is reported. Our results suggest that ZZ-PE38 could prove to be an invaluable tool for the evaluation of the suitability potential of antibodies and their cognate cell-surface antigens to be targeted by immunotherapeutics based on armed antibodies that require internalization.

MUC1 gene overexpressed in breast cancer: structure and transcriptional activity of the MUC1 promoter and role of estrogen receptor alpha (ERalpha) in regulation of the MUC1 gene expression

BACKGROUND

The MUC1 gene encodes a mucin glycoprotein(s) which is basally expressed in most epithelial cells. In breast adenocarcinoma and a variety of epithelial tumors its transcription is dramatically upregulated. Of particular relevance to breast cancer, steroid hormones also stimulate the expression of the MUC1 gene. The MUC1 gene directs expression of several protein isoforms, which participate in many crucial cell processes. Although the MUC1 gene plays a critical role in cell physiology and pathology, little is known about its promoter organization and transcriptional regulation. The goal of this study was to provide insight into the structure and transcriptional activity of the MUC1 promoter.

RESULTS

Using TRANSFAC and TSSG soft-ware programs the transcription factor binding sites of the MUC1 promoter were analyzed and a map of transcription cis-elements was constructed. The effect of different MUC1 promoter regions on MUC1 gene expression was monitored. Different regions of the MUC1 promoter were analyzed for their ability to control expression of specific MUC1 isoforms. Differences in the expression of human MUC1 gene transfected into mouse cells (heterologous artificial system) compared to human cells (homologous natural system) were observed. The role of estrogen on MUC1 isoform expression in human breast cancer cells, MCF-7 and T47D, was also analyzed. It was shown for the first time that synthesis of MUC1/SEC is dependent on estrogen whereas expression of MUC1/TM did not demonstrate such dependence. Moreover, the estrogen receptor alpha, ERalpha, could bind in vitro estrogen responsive cis-elements, EREs, that are present in the MUC1 promoter. The potential roles of different regions of the MUC1 promoter and ER in regulation of MUC1 gene expression are discussed.

CONCLUSION

Analysis of the structure and transcriptional activity of the MUC1 promoter performed in this study helps to better understand the mechanisms controlling transcription of the MUC1 gene. The role of different regions of the MUC1 promoter in expression of the MUC1 isoforms and possible function of ERalpha in this process has been established. The data obtained in this study may help in development of molecular modalities for controlled regulation of the MUC1 gene thus contributing to progress in breast cancer gene therapy.

ErbB1–4 expression in prostate cancer patients and its correlation to patients’ ethnicity and outcome

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Background: ErbB family is involved in both cancer progression and treatment response in solid tumors. Few inconclusive studies reported on ErbB over-expression in prostate cancer. We investigated ErbB1–4 expression in prostate cancer patients and its correlation to patients ethnicity and outcome. Methods: ErbB expression was evaluated by immunohistochemistry of prostate cancer specimen using polyclonal antibody (Santa Cruz, CA). The staining was recorded as negative (0/+1), moderately positive (+2) and highly positive (+3). Kattan nomogram was used to predict 5-yr progression-free probability, assuming that all patients received external beam radiation therapy (a total dose of 78 Gy) and hormonal manipulation. Origin was counted in all 43 patients: Ashkenazic patients were defined as those who immigrated from East/West Europe or North America and Sephardic patients - from Middle East and North Africa. Results: ErbB1 (+2/+3) was over-expressed in 12 and 7 patients for a total of 19/43 (44%). ErbB2 over-expression (+2/+3) was not found in all patients. ErbB3 over-expression of +2 was seen in 2 patients and none had +3 (2/43, 5%). ErbB4 over-expression (+2/+3) was seen in 5 and 11 patients for a total of 16/43 (37%). 22 patients were Ashkenazic and 21 - Sephardic. ErbB1 over-expression in Ashkenazic and Sephardic groups was 9/22 (41%) and 10/21 (48%). ErbB4 over-expression in the two groups was 7/22 (32%) and 9/21 (43%). Kattan score of <80 was seen in 20/43 and <60 in 7/43 patients. ErbB1 over-expression was noted in 11/20 and in 4/7 patients. ErbB4 over-expression was seen in 7/20 and in 4/7 patients. In both ErbB1 and ErbB4 over-expression and Kattan nomogram of <80 and <60 the Sephardic ethnicity dominated-7/11 (64%), 3/4 (75%), 5/7 (71%) and 3/4 (75%). Conclusions: ErbB1 and ErbB4 over-expression is presented in 43% and 37% patients while ErbB3 was over-expressed in 5%; no over-expression of ErbB2 was observed. Ashkenazic and Sephardic ethnicity were evenly distributed in the over-expressed ErbB1 and ErbB4 patients. However, a tendency to a worse prognosis, based on Kattan nomogram, was seen in over-expressed ErbB1 and ErbB4 patients from Sephardic ethnicity. Further studies on ethnicity and ErbB prevalence and prognosis are warranted.

No significant financial relationships to disclose.