Latest Publications

@article{jirik_blind_2019,

title = {Blind deconvolution estimation of an arterial input function for small animal DCE-MRI.},

author = {Radovan Jiřík and Torfinn Taxt and Ondřej Macíček and Michal Bartoš and Jiří Kratochvíla and Karel Souček and Eva Dražanová and Lucie Krátká and Aleš Hampl and Zenon Jr Starčuk},

doi = {10.1016/j.mri.2019.05.024},

issn = {1873-5894 0730-725X},

year  = {2019},

date = {2019-10-01},

journal = {Magnetic resonance imaging},

volume = {62},

pages = {46–56},

abstract = {PURPOSE: One of the main obstacles for reliable quantitative dynamic contrast-enhanced (DCE) MRI is the need for accurate knowledge of the arterial input function (AIF). This is a special challenge for preclinical small animal applications where it is very difficult to measure the AIF without partial volume and flow artifacts. Furthermore, using advanced pharmacokinetic models (allowing estimation of blood flow and permeability-surface area product in addition to the classical perfusion parameters) poses stricter requirements on the accuracy and precision of AIF estimation. This paper addresses small animal DCE-MRI with advanced pharmacokinetic models and presents a method for estimation of the AIF based on blind deconvolution. METHODS: A parametric AIF model designed for small animal physiology and use of advanced pharmacokinetic models is proposed. The parameters of the AIF are estimated using multichannel blind deconvolution. RESULTS: Evaluation on simulated data show that for realistic signal to noise ratios blind deconvolution AIF estimation leads to comparable results as the use of the true AIF. Evaluation on real data based on DCE-MRI with two contrast agents of different molecular weights showed a consistence with the known effects of the molecular weight. CONCLUSION: Multi-channel blind deconvolution using the proposed AIF model specific for small animal DCE-MRI provides reliable perfusion parameter estimates under realistic signal to noise conditions.},

note = {Place: Netherlands},

keywords = {*Magnetic Resonance Imaging, Algorithms, Animals, Arterial input function, Arteries/*diagnostic imaging, Blind deconvolution, Computer Simulation, Computer-Assisted/*methods, Contrast Media/*pharmacokinetics, DCE-MRI, Humans, Image Processing, Inbred BALB C, Mice, Necrosis/pathology, Perfusion, Pharmacokinetics, Regression Analysis, Reproducibility of Results, Signal-To-Noise Ratio},

pubstate = {published},

tppubtype = {article}

}

@article{remsik_trop-2_2018,

title = {Trop-2 plasticity is controlled by epithelial-to-mesenchymal transition.},

author = {Ján Remšík and Lucia Binó and Zuzana Kahounová and Gvantsa Kharaishvili and Šárka Šimecková and Radek Fedr and Tereza Kucírková and Sára Lenárt and Ximena Maria Muresan and Eva Slabáková and Lucia Knopfová and Jan Bouchal and Milan Král and Petr Beneš and Karel Soucek},

doi = {10.1093/carcin/bgy095},

issn = {1460-2180 0143-3334},

year  = {2018},

date = {2018-12-01},

journal = {Carcinogenesis},

volume = {39},

number = {11},

pages = {1411–1418},

abstract = {The cell surface glycoprotein Trop-2 is commonly overexpressed in carcinomas and represents an exceptional antigen for targeted therapy. Here, we provide evidence that surface Trop-2 expression is functionally connected with an epithelial phenotype in breast and prostate cell lines and in patient tumor samples. We further show that Trop-2 expression is suppressed epigenetically or through the action of epithelial-to-mesenchymal transition transcription factors and that deregulation of Trop-2 expression is linked with cancer progression and poor patient prognosis. Moreover, our data suggest that the cancer plasticity-driven intratumoral heterogeneity in Trop-2 expression may significantly contribute to response and resistance to therapies targeting Trop-2-expressing cells.},

note = {Place: England},

keywords = {Animals, Antigens, Breast Neoplasms/mortality/*pathology, Cadherins/biosynthesis, Carcinoma/*pathology, CD/biosynthesis, Cell Adhesion Molecules/genetics/*metabolism, Cell Line, Disease Progression, DNA Methylation/genetics, Epithelial Cells/*metabolism, Epithelial-Mesenchymal Transition/physiology, Female, Humans, Inbred BALB C, Male, Mice, Neoplasm/genetics/*metabolism, Prostatic Neoplasms/mortality/*pathology, Tumor, Xenograft Model Antitumor Assays},

pubstate = {published},

tppubtype = {article}

}

@article{jirik_blind_2014,

title = {Blind deconvolution in dynamic contrast-enhanced MRI and ultrasound.},

author = {Radovan Jiřík and Karel Souček and Martin Mézl and Michal Bartoš and Eva Dražanová and František Dráfi and Lucie Grossová and Jiří Kratochvíla and Ondřej Macíček and Kim Nylund and Aleš Hampl and Odd Helge Gilja and Torfinn Taxt and Zenon Jr Starčuk},

doi = {10.1109/EMBC.2014.6944569},

issn = {2694-0604 2375-7477},

year  = {2014},

date = {2014-01-01},

journal = {Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference},

volume = {2014},

pages = {4276–4279},

abstract = {This paper is focused on quantitative perfusion analysis using MRI and ultrasound. In both MRI and ultrasound, most approaches allow estimation of rate constants (Ktrans, kep for MRI) and indices (AUC, TTP) that are only related to the physiological perfusion parameters of a tissue (e.g. blood flow, vessel permeability) but do not allow their absolute quantification. Recent methods for quantification of these physiological perfusion parameters are shortly reviewed. The main problem of these methods is estimation of the arterial input function (AIF). This paper summarizes and extends the current blind-deconvolution approaches to AIF estimation. The feasibility of these methods is shown on a small preclinical study using both MRI and ultrasound.},

note = {Place: United States},

keywords = {Animals, Cell Line, Contrast Media/*pharmacokinetics, Experimental/diagnostic imaging/metabolism, Gadolinium DTPA/*pharmacokinetics, Humans, Inbred BALB C, Magnetic Resonance Imaging/methods, Mice, Neoplasm Transplantation, Neoplasms, Tissue Distribution, Tumor, Ultrasonography},

pubstate = {published},

tppubtype = {article}

}

@article{knopfova_c-myb_2012,

title = {c-Myb regulates matrix metalloproteinases 1/9, and cathepsin D: implications for matrix-dependent breast cancer cell invasion and metastasis.},

author = {Lucia Knopfová and Petr Beneš and Lucie Pekarčíková and Markéta Hermanová and Michal Masařík and Zuzana Pernicová and Karel Souček and Jan Smarda},

doi = {10.1186/1476-4598-11-15},

issn = {1476-4598},

year  = {2012},

date = {2012-03-01},

journal = {Molecular cancer},

volume = {11},

pages = {15},

abstract = {BACKGROUND: The c-Myb transcription factor is essential for the maintenance of stem-progenitor cells in bone marrow, colon epithelia, and neurogenic niches. c-Myb malfunction contributes to several types of malignancies including breast cancer. However, the function of c-Myb in the metastatic spread of breast tumors remains unexplored. In this study, we report a novel role of c-Myb in the control of specific proteases that regulate the matrix-dependent invasion of breast cancer cells. RESULTS: Ectopically expressed c-Myb enhanced migration and ability of human MDA-MB-231 and mouse 4T1 mammary cancer cells to invade Matrigel but not the collagen I matrix in vitro. c-Myb strongly increased the expression/activity of cathepsin D and matrix metalloproteinase (MMP) 9 and significantly downregulated MMP1. The gene coding for cathepsin D was suggested as the c-Myb-responsive gene and downstream effector of the migration-promoting function of c-Myb. Finally, we demonstrated that c-Myb delayed the growth of mammary tumors in BALB/c mice and affected the metastatic potential of breast cancer cells in an organ-specific manner. CONCLUSIONS: This study identified c-Myb as a matrix-dependent regulator of invasive behavior of breast cancer cells.},

note = {Place: England},

keywords = {Animals, Breast Neoplasms/genetics/*metabolism, Cathepsin D/genetics/*metabolism, Cell Line, Cell Movement/genetics/physiology, Electrophoresis, Female, Humans, Immunoblotting, Inbred BALB C, Matrix Metalloproteinase 1/genetics/*metabolism, Matrix Metalloproteinase 9/genetics/*metabolism, Mice, Neoplasm Metastasis/genetics/physiopathology, Polyacrylamide Gel, Proto-Oncogene Proteins c-myb/genetics/*metabolism, Real-Time Polymerase Chain Reaction, RNA, Small Interfering, Tumor},

pubstate = {published},

tppubtype = {article}

}