No description available.

No description available.

Pro-migratory signals mediated by the tumor microenvironment contribute to the cancer progression cascade, including invasion, metastasis and resistance to therapy. Derived from in vitro studies, isolated molecular steps of cancer invasion programs have been identified but their integration into the tumor microenvironment and suitability as molecular targets remain elusive. The purpose of the study was to visualize central aspects of tumor progression, including proliferation, survival and invasion by real-time intravital microscopy. The specific aims were to monitor the kinetics, mode, adhesion and chemoattraction mechanisms of tumor cell invasion, the involved guidance structures, and the response of invasion zones to anti-cancer therapy. To reach deeper tumor regions by optical imaging with subcellular resolution, near-infrared and infrared excited multiphoton microscopy was combined with a modified dorsal skinfold chamber model. Implanted HT-1080 fibrosarcoma and B16/F10 and MV3 melanoma tumors developed zones of invasive growth consisting of collective invasion strands that retained cell-cell contacts and high mitotic activity while invading at velocities of up to 200 μm per day. Collective invasion occurred predominantly along preexisting tissue structures, including blood and lymph vessels, collagen fibers and muscle strands of the deep dermis, and was thereby insensitive to RNAi based knockdown and/or antibody-based treatment against β1 and β3 integrins, chemokine (SDF-1/CXCL12) and growth factor (EGF) signaling. Therapeutic hypofractionated irradiation induced partial to complete regression of the tumor main mass, yet failed to eradicate the collective invasion strands, suggesting a microenvironmentally privileged niche. Whereas no radiosensitization was achieved by interference with EGFR or doxorubicin, the simultaneous inhibition of β1 and β3 integrins impaired cell proliferation and survival in spontaneously growing tumors and strongly enhanced the radiation response up to complete eradication of both main tumor and invasion strands. In conclusion, collective invasion in vivo is a robust process which follows preexisting tissue structures and is mainly independent of established adhesion and chemoattractant signaling. Due to its altered biological response to irradiation, collective invasion strands represent a microenvironmentally controlled and clinically relevant resistance niche to therapy. Therefore supportive regimens, such as anoikisinduction by anti-integrin therapy, may serve to enhance radio- and chemoefficacy and complement classical treatment regimens. / Die Progression von Tumorerkrankungen, einschließlich Tumorinvasion, Metastasierung und Therapieresistenz wird unter anderem durch migrationsfördernde Signale aus der Tumorumgebung vermittelt. Zur bisherigen Aufklärung einzelner Schritte des Tumorinvasions- und Progressionsprogramms trugen dabei wesentlich In-vitro-Studien bei, jedoch erfordert die Darstellung der Relevanz molekularer Zielstrukturen und deren Funktion im Tumormikromilieu die Validierung in geeigneten In-vivo-Tumormodellen. Ziel dieser Studie war, zelluläre und molekulare Mechanismen der Tumorprogression inklusive Proliferation, Überleben und Invasion mittels Echtzeit-Intravitalmikroskopie darzustellen. Untersucht wurden insbesondere die Kinetik und Arten der Tumorzellinvasion, die zugrunde liegenden Adhäsionswege und pro-migratorischen Signale (EGF, SDF-1), beteiligte Leitstrukturen des Tumorstromas, und Strategien, therapeutisch gegen Invasionszonen vorzugehen. Um tiefe Tumorareale mittels subzellulär aufgelöster optischer Bildgebung zu erreichen, wurde nah-infrarote und infrarote Multiphotonenmikroskopie mit einem modifizierten Rückenkammermodell kombiniert. Orthotope Xeno- und Allotransplantate von HT-1080-Fibrosarkom- und B16/F10- oder MV3-Melanomzellen entwickelten dabei ausgeprägte invasive Wachstumszonen bestehend aus kollektiven Invasionssträngen mit intakten Zell-Zell-Kontakten und zeitgleicher Mitoseaktivität, die Geschwindigkeiten von bis zu 200 μm pro Tag erreichten. Diese kollektive Invasion orientierte sich bevorzugt entlang von Funktionsstrukturen der tiefen Dermis wie Blut- und Lymphgefäßen, Kollagenfasern und Muskelsträngen. RNAibasierende Herrunterregulation und/oder Injektion blockierender Antikörper gegen β1 und β3 Integrine, wie auch Inhibition von EGF führten nur zu minimaler Änderung der Invasionseffizienz. Therapeutische hypofraktionierte Bestrahlung induzierte partielle bis komplette Regression der Tumorhauptmasse, nicht jedoch der kollektiven Invasionsstränge, was auf eine kombinierte Invasions- und Resistenznische hinweist. Weder Doxorubicin noch gegen EGFR gerichtete Antikörper steigerten die Radiosensitivität, jedoch führte die simultane Inhibition von β1 und β3 Integrinen zu einer starken Hemmung von Proliferation und Überleben spontan wachsender Tumoren (Anoikis) und verstärkte die Strahlungssensitivität bis hin zum kompletten Verschwinden von sowohl Tumorhauptmasse wie auch Invasionsträngen. Kollektive Invasion ist somit ein wichtiger Invasionsmodus, der sich an vorbestehenden Gewebsstrukturen orientiert und unabhängig von Integrinen und EGF- und SDF-1-Signalen erfolgt. Die kollektiven Stränge entwickeln dabei eine vom Haupttumor verschiedene biologische Reaktion auf Bestrahlung und entsprechen damit einer durch die Mikroumgebung kontrollierten und von Integrinsignalen abhängenden Resistenznische. Somit könnte eine zusätzliche anti- Integrin-Therapie die Effizienz von Bestrahlung und Chemotherapie erhöhen und klassische Behandlungsschemen/-programme ergänzen.

Hepatocellular carcinoma (HCC) or hepatoma is the fifth most common cancer and the third most common cause of cancer-related deaths worldwide. Early detection of HCC still remains challenge. Patients with late-stage HCCs have very limited therapeutic options and relatively poor prognosis. Therefore, recognition of useful tumor marker for the diagnosis of HCC may aid in the management with this lethal malignancy, and designing effective therapies. In our previous study, through in silico data mining of numerous available cDNA microarray databases, the CDC28 protein kinase regulatory subunit 1B (CKS1B) transcript was found to be frequently upregulated in HCCs and the gene is strongly associated in clinical aggressiveness. Moreover, gain of chromosome 1q copy is one of the most frequently detected alterations in HCC and 1q21 is the most frequent minimal amplifying region. Mammalian CKS1B gene, a member of the highly conserved cyclin kinase subunit 1 protein family, mapped to 1q21.2-q22, which interacts with cyclin-dependent kinases and frequently up-regulated in human HCC specimens, and this gene also has been reported to play oncogenic roles in other human cancers. Furthermore, this gene was identified as an essential cofactor of S-phase kinase-associated protein 2 (SKP2) in the SKP2-containing SKP1-Cullin1-F-box ubiquitin ligase complex¡Vmediated ubiquitination of the cell cycle inhibitor protein cyclin-dependent kinases 1A (p27kip1) that leads to the proteasomal degradation of p27kip1. In the present study, our results indicate that CKS1B overexpression may contribute to hepatocarcinogenesis by enhancing the cellular tumorigenic potential. In addition, CKS1B was correlated with the HCC-derived cells proliferation, and CKS1B knockdown significantly inhibited the tumorigenic potential of HCC-derived cells. In this study, we examined that CKS1B knockdown and overexpressed in HCC cells significantly changed the expression of genes known to participate in various cellular processes, including, apoptosis, cell cycle, proliferation, viability, invasion, and migration, implying that CKS1B may play considerable and diverse roles in hepatocarcinogenesis.

Lung cancer is the leading cause of death in Taiwan cancer patients. The cancer cells are capable of spreading by metastasis and invasion. When tumors spread to distant parts of the body, it is difficult to treat by surgery. In this study, we discovered the novel anti-invasion drugs DMHMPC and DE-DMPC that can inhibit the metastasis and invasion of human lung cancer cell A549. From screening of a chemical library of 420 small molecule compounds using Boyden chamber and MTT assay, the compound DMHMPC and DE-DMPC showed the inhibitory activity toward the invasiveness but not proliferation in human lung cancer cell A549. The results of wound healing assay also showed that DMHMPC and DE-DMPC inhibited the motility of A549 in a dose dependent manner. Moreover, the results of growth curve assay and colony formation assay also showed that DMHMPC and DE-DMPC are not effect proliferation in A549. Together, these results suggested that DMHMPC and DE-DMPC could be the potential drugs to inhibit the invasion of cancer cells that may lead to the new avenue of the cancer prevention therapy.

Mémoire DIS : Biologie médicale : Nantes : 2002. / Mémoire : 2002NANT1DIS. Bibliogr. f. 84-93.

This thesis introduces a workflow to accomplish invasion-consistent Nuclear Magnetic Resonance (NMR) measurement interpretations. Magnetic resonance measurements are affected by mud-filtrate invasion because the radial depth of investigation (DOI) of NMR logging tools is very shallow (approximately 1 to 4 inches). This characteristic indicates that identification of in-situ fluid saturations from NMR measurements is uncertain. Calculation of fluid saturations from apparent electrical resistivities and nuclear logs does not guarantee a precise estimation of the fluid distributions. Free water in the reservoir displaced by oil based mud (OBM) poses more challenges in the estimation of in-situ fluid saturations. To mitigate this ambiguity, I construct layer-by-layer static and dynamic reservoir models. The common stratigraphic framework (CSF) proposed by Voss et al. (2009) was used to construct the earth model. Appraisal of static petrophysical properties is based on the iterative adjustments to minimize the discrepancy between available well logs and their numerical simulations. Evaluation of dynamic petrophysical properties can be achieved with the simulation of mud-filtrate invasion. This simulation can assess accurate fluid saturations at specific radial distances. In addition, numerically simulated apparent resistivity and nuclear logs are in agreement with measured logs. Algorithms are also developed to cross-validate NMR measurements based on the assumption of spherically shaped water-wet pores. The algorithms need all petrophysical parameters and fluid saturations yielded from the dynamic model as inputs. Various NMR parameter changes were tested to validate this algorithm. Examples of NMR responses include wettability change and kerogen contained in nano-scale pores. For the field case examples, two 15 meter-thick depth intervals in oil- and gas-bearing siliciclastic formations were selected. Two-dimensional (2D) NMR simulations were performed with petrophysical parameters provided from the numerical simulation of mud-filtrate invasion. The 2D NMR maps are more favorable in fluid typing than conventional NMR T₂ distributions because they contrast fluid diffusion coefficient. Comparisons of simulation results to inversion results confirm the validity of the workflow introduced in this thesis for the quantification of virgin reservoir fluids and mud-filtrate saturations. Finally, forward modeling and inversion processes are applied to 2D NMR data. The reconstructed echo decay sequences are more advantageous than raw measurements because of their higher signal to noise ratio (SNR). Linear inversion using these echo decay sequences provides proton density distribution functions of D-T₂ and T₁-T₂ maps. Application of inversion to the two field cases measured from two different radial depths verifies the validity of the NMR interpretations. / text

No description available.

Cancer cell metastasis is induced by actin-dependent cell migration and is affected by cytoskeletal remodelling proteins. FMNL2 is one such protein which promotes colorectal cancer (CRC) cell metastasis and amoeboid style invasion of melanoma cells. FMNL2 mRNA is subject to alternative splicing and studies suggest that the resulting encoded proteins are likely to differ in their regulation, subcellular localization and activity. We identified four FMNL2 isoforms (ITM, YHY, PMR and TQS) expressed in non-invasive (SW480) and invasive (SW620) CRC cells, as well as in highly invasive A375 amoeboid melanoma cells. qPCR data suggests that an “invasive” isoform (TQS) may be preferentially expressed in highly invasive and amoeboid cell lines. Boyden chamber invasion assay results show that FMNL2 knockdown inhibits amoeboid style invasion in two melanoma cell lines and that TQS is the most efficient isoform at rescuing the invasive phenotype. This study provides a further understanding of FMNL2’s role in invasion and metastasis and identifies specific targets for the development of future antimetastatic therapies.

Ulm, Univ., Diss., 2007.