Mobilities of a drop and an encapsulated squirmer.

We have analyzed the dynamics of a spherical, uniaxial squirmer which is located inside a spherical liquid drop at general position [Formula: see text]. The squirmer is subject to an external force and torque in addition to the slip velocity on its surface. We have derived exact analytical expressions for the linear and rotational velocity of the squirmer as well as the linear velocity of the drop for general, non-axisymmetric configurations. The mobilities of both, squirmer and drop, are in general anisotropic, depending on the orientation of [Formula: see text], relative to squirmer axis, external force or torque. We discuss their dependence on the size of the squirmer, its distance from the center of the drop and the viscosities. Our results provide a framework for the discussion of the trajectories of the composite system of drop and enclosed squirmer.

Controlled locomotion of a droplet propelled by an encapsulated squirmer.

We work out the propulsion of a viscous drop which is driven by two mechanisms: the active velocity of an encapsulated squirmer and an externally applied force acting on the squirmer. Of particular interest is the existence of a stable comoving state of drop and squirmer, allowing for controlled manipulation of the viscous drop by external forcing. The velocities of droplet and squirmer, as well as the conditions for a stable comoving state are worked out analytically for the axisymmetric configuration with a general displacement of the squirmer from the center of the droplet.

Self-propulsion of droplets driven by an active permeating gel.

We discuss the flow field and propulsion velocity of active droplets, which are driven by body forces residing on a rigid gel. The latter is modelled as a porous medium which gives rise to permeation forces. In the simplest model, the Brinkman equation, the porous medium is characterised by a single lengthscale [Formula: see text] --the square root of the permeability. We compute the flow fields inside and outside of the droplet as well as the energy dissipation as a function of [Formula: see text]. We furthermore show that there are optimal gel fractions, giving rise to maximal linear and rotational velocities. In the limit [Formula: see text], corresponding to a very dilute gel, we recover Stokes flow. The opposite limit, [Formula: see text], corresponding to a space filling gel, is singular and not equivalent to Darcy's equation, which cannot account for self-propulsion.

[The pathology of adverse events with immune checkpoint inhibitors]. / Pathologie der Nebenwirkungen von Immune-Checkpoint-Inhibitoren.

BACKGROUND: Immunotherapy has gained importance with the development of new effective cancer treatments. Immune checkpoint inhibitors (ICI) are monoclonal antibodies that promote T­cell mediated tumor immune rejection. Checkpoint blockade also carries the risk of inducing autoimmune reactions ("immune related adverse events", irAEs). The diagnosis and classification of irAEs constitute a new and important field in pathology. AIM: Practice-oriented review of the diagnosis and classification of irAEs. MATERIALS AND METHODS: Structured, selective literature review based on PubMed und UpToDate ® online. RESULTS: The most common irAEs affect the skin, the gastrointestinal tract, the liver, and the respiratory system. The correct diagnosis and classification of irAEs by an interdisciplinary care team is essential for appropriate therapy and the prevention of long-term sequelae. Other important irAEs affect the endocrine organs, the heart, the joints, the kidneys and the nervous system. Because of their rarity and/or limited options for bioptic diagnosis, only limited data on the morphology and pathophysiology of these irAEs are currently available. Autopsies carried out after ICI therapy constitute an important element of quality control and allow better documentation of the incidence and pathogenesis of irAEs. DISCUSSION: Pathology plays a central role in the diagnosis and treatment of irAEs. Future studies may contribute to a better mechanistic understanding of irAEs for individualized knowledge-based risk assessment.

The immune system and cancer evasion strategies: therapeutic concepts.

The complicated interplay between cancer and the host immune system has been studied for decades. New insights into the human immune system as well as the mechanisms by which tumours evade immune control have led to the new and innovative therapeutic strategies that are considered amongst the medical breakthroughs of the last few years. Here, we will review the current understanding of cancer immunology in general, including immune surveillance and immunoediting, with a detailed look at immune cells (T cells, B cells, natural killer cells, macrophages and dendritic cells), immune checkpoints and regulators, sialic acid-binding immunoglobulin-like lectins (Siglecs) and other mechanisms. We will also present examples of new immune therapies able to reverse immune evasion strategies of tumour cells. Finally, we will focus on therapies that are already used in daily oncological practice such as the blockade of immune checkpoints cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed death-1 (PD-1) in patients with metastatic melanoma or advanced lung cancer, or therapies currently being tested in clinical trials such as adoptive T-cell transfer.

Antibody-based immunotherapy for ovarian cancer: where are we at?

Cytoreductive surgery and chemotherapy continue to be the mainstay of ovarian cancer treatment. However, as mortality from advanced ovarian cancer remains very high, novel therapies are required to be integrated into existing treatment regimens. Immunotherapy represents an alternative and rational therapeutic approach for ovarian cancer based on a body of evidence supporting a protective role of the immune system against these cancers, and on the clinical success of immunotherapy in other malignancies. Whether or not immunotherapy will have a role in the future management of ovarian cancer is too early to tell, but research in this field is active. This review will discuss recent clinical developments of selected immunotherapies for ovarian cancer which fulfil the following criteria: (i) they are antibody-based, (ii) target a distinct immunological pathway, and (iii) have reached the clinical trial stage. Specifically, the focus is on Catumaxomab (anti-EpCAM×anti-CD3), Abagovomab, Oregovomab (anti-CA125), Daclizumab (anti-CD25), Ipilimumab (anti-CTLA-4), and MXD-1105 (anti-PD-L1). Catumaxomab has reached phase III clinical trials and exhibits promise with reports, showing that it can cause a significant and sustained reduction in ascites. Phase I-III clinical trials continue to be conducted on the other antibodies, some of which have had encouraging reports. We will also provide our perspective on the future of immunotherapy for ovarian cancer, and how it may be best employed in treatment regimens.

Acute toxoplasmosis mimicking melanoma metastases: review of conditions causing false-positive results on (18)F-FDG PET/CT.

Invasive malignant melanoma is the most common fatal form of skin cancer. Fluorine-18-fluorodeoxyglucose positron emission tomography-computed tomography demonstrates a very high sensitivity and specificity for the detection of melanoma metastases. Here, we report an unusual case of toxoplasma lymphadenitis in a male adult patient mimicking a malignant cervical lymphadenopathy. Toxoplasmosis is a zoonosis caused by the intracellular parasite Toxoplasma gondii, which is usually asymptomatic in immunocompetent hosts.

[Cancer immunotherapy - novel perspectives]. / Neue Perspektiven in der immunologischen Krebstherapie.

The concept of cancer immune surveillance dates back decades and is based on the hypothesis that the immune system can suppress the development or progression of spontaneous malignancies. Immunotherapy strategies include antitumor monoclonal antibodies, cancer vaccines, adoptive transfer of ex vivo activated T and natural killer cells, and administration of antibodies that either costimulate immune cells or block immune inhibitory pathways. Sipuleucel-T is the first anticancer vaccine that improved overall survival in a randomized clinical study in patients with metastatic castration-resistant prostate cancer. Similarly, ipilimumab, a monoclonal antibody blocking cytotoxic T-lymphocyte antigen 4 (CTLA-4), showed an overall survival benefit and durable tumor responses in pretreated and previously untreated patients with metastatic melanoma. In Switzerland, ipilimumab is approved for second line treatment in metastatic melanoma. These recent positive results of clinical trials with novel immunoactive drugs raised expectations that immunotherapy will play a crucial role in the anticancer treatment of the next decade.

Targeting immunoliposomes to EGFR-positive glioblastoma.

BACKGROUND: We assessed the capacity of epidermal growth factor receptor (EGFR)-targeted immunoliposomes to deliver cargo to brain tumor tissue in patients with relapsed glioblastoma harboring an EGFR amplification. We aimed to assess the tolerability and effectiveness of anti-EGFR immunoliposomes loaded with doxorubicin (anti-EGFR ILs-dox) in glioblastoma multiforme patients. PATIENTS AND METHODS: Patients with EGFR-amplified, relapsed glioblastoma were included in this phase I pharmacokinetic trial. Patients received up to four cycles of anti-EGFR ILs-dox. Twenty-four hours later, plasma and cerebrospinal fluid (CSF) samples were obtained. In addition, we also treated three patients with anti-EGFR ILs-dox before resection of their relapsed glioblastoma. Doxorubicin concentrations were measured in plasma, CSF, and tumor tissue. Safety and efficacy parameters were also obtained. RESULTS: There were no or negligible levels of doxorubicin found in the CSF demonstrating that anti-EGFR ILs-dox are not able to cross the blood-brain barrier (BBB). However, significant levels were detected in glioblastoma tissue 24 h after the application, indicating that the disruption of BBB integrity present in high-grade gliomas might enable liposome delivery into tumor tissue. No new safety issues were observed. The median progression-free survival was 1.5 months and the median overall survival was 8 months. One patient undergoing surgery had a very long remission suggesting that neoadjuvant administration may have a positive effect on outcome. CONCLUSIONS: We clearly demonstrate that anti-EGFR-immunoliposomes can be targeted to EGFR-amplified glioblastoma and cargo-in this case doxorubicin-can be delivered, although these immunoliposomes do not cross the intact BBB. (The GBM-LIPO trial was registered as NCT03603379).

Long-term outcomes of operable stage III NSCLC in the pre-immunotherapy era: results from a pooled analysis of the SAKK 16/96, SAKK 16/00, SAKK 16/01, and SAKK 16/08 trials.

BACKGROUND: Chemoradiotherapy with durvalumab consolidation has yielded excellent results in stage III non-small-cell lung cancer (NSCLC). Therefore, it is essential to identify patients who might benefit from a surgical approach. MATERIAL AND METHODS: Data from 437 patients with operable stage III NSCLC enrolled in four consecutive Swiss Group for Clinical Cancer Research (SAKK) trials (16/96, 16/00, 16/01, 16/08) were pooled and outcomes were analyzed in 431 eligible patients. All patients were treated with three cycles of induction chemotherapy (cisplatin/docetaxel), followed in some patients by neoadjuvant radiotherapy (44 Gy, 22 fractions) (16/00, 16/01, 16/08) and cetuximab (16/08). RESULTS: With a median follow-up time of 9.3 years (range 8.5-10.3 years), 5- and 10-year overall survival (OS) rates were 37% and 25%, respectively. Overall, 342 patients (79%) underwent tumor resection, with a complete resection (R0) rate of 80%. Patients (n = 272, 63%) with R0 had significantly longer OS compared to patients who had surgery but incomplete resection (64.8 versus 19.2 months, P < 0.001). OS for patients who achieved pathological complete remission (pCR) (n = 66, 15%) was significantly better compared to resected patients without pCR (86.5 versus 37.0 months, P = 0.003). For patients with pCR, the 5- and 10-year event-free survival and OS rates were 45.7% [95% confidence interval (CI) 32.8% to 57.7%] and 28.1% (95% CI 15.2% to 42.6%), and 58.2% (95% CI 45.2% to 69.2%) and 45.0% (95% CI 31.5% to 57.6%), respectively. CONCLUSION: We report favorable long-term outcomes in patients with operable stage III NSCLC treated with neoadjuvant chemotherapy with cisplatin and docetaxel ± neoadjuvant sequential radiotherapy from four prospective SAKK trials. Almost two-third of the patients underwent complete resection after neoadjuvant therapy. We confirm R0 resection and pCR as important predictors of outcome.

Integrated functional and spatial profiling of tumour immune responses induced by immunotherapy: the iPROFILER platform.

BACKGROUND: Cancer immunotherapy elicits functional activation and changes in immune cell distribution in cancer. Tumour heterogeneity is a reason for treatment failure but is difficult to capture in experimental settings. This proof-of-principle study describes the integrated functional and digital spatial profiling platform iPROFILER to capture in-situ immune activation patterns with high precision. MATERIALS AND METHODS: iPROFILER combines an algorithm-based image analysis approach for spatial profiling with functional analyses of patient-derived tumour fragments (PDTFs). This study utilized a folate receptor 1 (FOLR1)xCD3 bispecific antibody in dual-affinity re-targeting (DART) format as a tool for inducing T-cell responses in patient tumour samples, and an in-depth investigation of the immune perturbations induced in the tumour microenvironment was performed. RESULTS: Ex-vivo DART stimulation induces upregulation of multiple activation markers in CD4+ and CD8+ T-cell populations and secretion of pro-inflammatory cytokines in FOLR1-positive tumour specimens. This response was reduced or absent in tissue samples that did not express FOLR1. Immunological responses were driven by a strong induction of interferon gamma (IFNγ) and IFNγ-induced chemokines suggestive of activation of cytotoxic or Th1-like T cells. Ex-vivo DART treatment led to a numerical increase in effector T cells and an upregulation of immune activation markers in the tumour microenvironment as captured by digital image analysis. Analysis of immune activation in tumour and stromal regions further supported the potential of the platform to measure local differences in cell-type-specific activation patterns. CONCLUSIONS: iPROFILER effectively combines functional and spatial readouts to investigate immune responses ex vivo in human tumour samples.

MAGE-C1/CT-7 expression in plasma cell myeloma: sub-cellular localization impacts on clinical outcome.

Plasma cell myelomas (PMs) have a poor prognosis. Cancer-testis (CT) antigens are immunogenic proteins, representing potential targets for tumor vaccination strategies. The expression of the CT antigens GAGE, MAGE-A4, MAGE-C1/CT-7, and NY-ESO-1 was investigated on paraffin-embedded bone marrow biopsies from 219 PM and 8 monoclonal gammopathy of undetermined significance (MGUS) patients. The frequency and prognostic impact of these CT antigens were compared with known morphological prognostic markers (i.e. Mib1 labeling index) and the presence of the translocations t(4;14)(p16.3; q32) and t(11;14)(q13;q32). We show that MAGE-C1/CT-7 is the most prevalent CT antigen, expressed in 57% of PMs in a high percentage of tumor cells. While MAGE-C1/CT-7 was absent in non-malignant plasma cells, plasma cells of patients with MGUS did express MAGE-C1/CT-7, but no other CT antigens. MAGE-C1/CT-7 was more frequently expressed in PMs with an elevated proliferation rate (Mib1 >10%) compared to PMs with a low proliferation rate (Mib1

Diffraction from the beta-sheet crystallites in spider silk.

We analyze the wide-angle X-ray scattering from oriented spider silk fibers in terms of a quantitative scattering model, including both structural and statistical parameters of the beta-sheet crystallites of spider silk in the amorphous matrix. The model is based on kinematic scattering theory and allows for rather general correlations of the positional and orientational degrees of freedom, including the crystallite's size, composition and dimension of the unit cell. The model is evaluated numerically and compared to experimental scattering intensities allowing us to extract the geometric and statistical parameters. We show explicitly that for the experimentally found mosaicity (width of the orientational distribution) intercrystallite effects are negligible and the data can be analyzed in terms of single-crystallite scattering, as is usually assumed in the literature.

Mechanical properties of spider dragline silk: humidity, hysteresis, and relaxation.

Spider silk is well-known for its outstanding mechanical properties. However, there is a significant variation of these properties in literature and studies analyzing large numbers of silk samples to explain these variations are still lacking. To fill this gap, the following work examines the mechanical properties of major ampullate silk based on a large ensemble of threads from Nephila clavipes and Nephila senegalensis. In addition, the effect of relative humidity (RH) on the mechanical properties was quantified. The large effect of RH on the mechanical properties makes it plausible that the variation in the literature values can to a large extent be attributed to changes in RH. Spider silk's most remarkable property-its high tenacity-remains unchanged. In addition, this work also includes hysteresis as well as relaxation measurements. It is found that the relaxation process is well described by a stretched exponential decay.

Clinical significance of cyclooxygenase-2 (COX-2) in multiple myeloma.

Several biological and clinical considerations suggest the involvement of cyclooxygenase-2 (COX-2), the key enzyme of prostaglandin (PG) synthesis, in the pathogenesis and progression of haematological malignancies. Despite the wealth of data concerning COX-2 expression, only limited information is available on multiple myeloma (MM). Using standard immunohistochemistry we therefore evaluated COX-2 protein expression in samples from 57 patients with a primary diagnosis of MM. Time to progression and a variety of clinicopathological features were evaluated by the Kaplan-Meier method and the Cox regression model. In addition, COX-2 expression was evaluated by staining bone marrow from healthy donors and 11 patients with MGUS. Overall, 31 MM samples (54%) expressed COX-2. Positivity for COX-2 was unrelated to stage or clinical or molecular features of the disease. However, patients with COX-2 positive tumours experienced a significantly shorter time to progression (17 vs 30 months, p = 0.037). In summary, COX-2 is frequently expressed in MM and correlates with shorter progression-free survival.

Establishment of micrometastatic carcinoma cell lines: a novel source of tumor cell vaccines.

BACKGROUND: Cancer cells of microscopic metastases can be envisaged as ideal constituents for the development of a genetically modified, autologous tumor cell vaccine. However, their extremely low number has thus far blocked this approach. PURPOSE: The aim of this study was to culture micrometastatic tumor cells present in bone marrow of patients with various forms of epithelial cancer and to thereby establish immortalized cell lines. METHODS: Bone marrow aspirates from the upper iliac crest of 152 patients with cancer of the prostate, kidney, lung, breast, or colorectum were cultured at 1 x 10(7) to 6 x 10(7) mononuclear cells (MNC) per flask in fetal calf serum-containing RPMI-1640 medium supplemented with 10 ng/mL epidermal growth factor and 10 ng/mL basic fibroblast growth factor. The proliferation of epithelial cells on extracellular matrix-coated plates was monitored by sampling and staining aliquots with cytokeratin-specific antibodies. After 3-6 weeks in culture, the cells were transferred to Petri dishes, and 200-300 epithelial cells per plate were microinjected with DNA encoding for the simian virus 40 (SV40) large T antigen. Cells were screened at various time points for expression of large T antigen and epithelial markers, such as cytokeratins, prostate-specific antigen, prolactin-inducible protein, or intestinal-specific annexin; their bone marrow-seeking potential was tested in immunodeficient SCID (i.e., severe combined immunodeficiency) mice given subcutaneous transplants of the immortalized cells. RESULTS: Prior to culture, more than 90% of all samples presented with fewer than 10 tumor cells per 8 x 10(5) MNC. In 68 cases (44.7%), the established culture conditions allowed a two to four log transient expansion of these cells with rather small differences among the tumor types studied. Epidermal growth factor and basic fibroblast growth factor were found to be essential for this culture system. After microinjection of the propagated cells with T-antigen DNA, permanent cell lines were obtained; some of these cell lines (prostate and lung cancer cell lines) are now beyond culture passage 80. The cells showed no notable changes in the pattern of expressed epithelial antigens and were able to disseminate into bone marrow in SCID mice. CONCLUSIONS: This procedure allows the selective immortalization of micrometastatic carcinoma cells. Integration of SV40 DNA and expression of T antigen did not substantially change the epithelial phenotype of the propagated cells. IMPLICATIONS: The established system will allow an in-depth molecular analysis of human micrometastatic cancer cells and could become a useful source for the generation of autologous tumor cell vaccines.

[Molecular targeted therapy]. / Molekular zielgerichtete Therapie.

Until recently, cancer therapy was based on three modalities: surgery, radiotherapy, and cytostatic chemotherapy. In most instances treatment of solid tumors was a surgical domain. For patients with incomplete resection or relapse after surgery, radiotherapy and chemotherapy usually offered only partial response and mostly of limited duration. By the mid-1990s visions of antibody-based therapies, vaccination strategies, and even gene-specific therapies existed but seemed far from clinical practice. United States Federal Drug Administration approval of the humanized antibody rituximab (1997) and the tyrosine kinase inhibitor imatinib (2001) has changed perceptions of oncologic treatment. These drugs turned visions into reality and led the pharmaceutical industry, clinicians, and patients to new perspectives. This article gives an overview of the development of this fourth modality in cancer therapy, so-called targeted therapy.

Phenotypic characteristics of cell lines derived from disseminated cancer cells in bone marrow of patients with solid epithelial tumors: establishment of working models for human micrometastases.

Bone marrow (BM) is a clinically relevant site of micrometastatic disease in patients with solid epithelial tumors. It is, therefore, important to establish suitable models that allow the in-depth characterization of disseminated tumor cells present at low frequencies of 10(-5)-10(-6) nucleated BM cells. The aim of this study was to assess common phenotypic features of nine tumor cell lines established from BM of patients with cancer of the prostate (four cell lines), breast (two cell lines), lung (two cell lines), and colon (one cell line) using immunocytochemistry, flow cytometry, and reverse transcription-PCR. All cell lines stained positive for both cytokeratins, the epithelial intermediate filaments, and the epithelial cell adhesion molecule E-cadherin, and they lacked markers of BM-derived cells. The tumor origin of the cell lines was supported by the expression of the ErbB2 oncogene (seven of nine) and MAGE mRNA (eight of eight). All cell lines coexpressed cytokeratin and vimentin, the mesenchymal intermediate filament, indicating an epithelial-mesenchymal transition of micrometastatic cells. The invasive phenotype of the immortalized cells was also reflected by the consistent expression of several metastasis-associated adhesion molecules, including alpha5 (eight of nine), alpha6 (five of nine), alphaV (nine of nine), beta1 (nine of nine), and beta3 (nine of nine) integrin subunits and the Mr 67,000 laminin receptor (seven of nine). Contrary to our expectations, metastasis-promoting CD44 variant isoforms were only detected on two lines, whereas all cell lines expressed MUC18/melanoma cell adhesion molecule and intercellular adhesion molecule-1, two members of the immunoglobulin superfamily of adhesion molecules that are not frequently found on primary carcinoma cells. The consistent expression of various epithelial and tumor-associated antigens provides evidence that the established cell lines are derived from disseminated cancer cells present in the BM. The invasive phenotype of the immortalized cells was mirrored by their epithelial-mesenchymal transition and the expression of several metastasis-associated molecules, which might be potential candidates for novel therapeutic targets.

Limitations of reverse-transcriptase polymerase chain reaction analyses for detection of micrometastatic epithelial cancer cells in bone marrow.

PURPOSE: This study was designed to evaluate the potential of reverse-transcriptase polymerase chain reaction (RT-PCR) analyses for the detection of micrometastatic carcinoma cells in bone marrow (BM). PATIENTS AND METHODS: The specificity of RT-PCR assays with primers specific for various tumor-associated and organ-specific mRNA species was examined by analysis of 53 BM aspirates from control patients with no epithelial malignancy. In addition, BM samples from 63 patients with prostate cancer (n = 53) or breast cancer (n = 10) were analyzed by RT-PCR with primers specific for prostate-specific antigen (PSA) mRNA. As a reference method, all samples were analyzed simultaneously by an established immunocytochemical assay, using monoclonal antibodies (mAbs) against cytokeratins (CK) for tumor-cell detection. RESULTS: Seven of eight marker species could be detected in a considerable number of BM samples from control patients: epithelial glycoprotein-40 (EGP-40; 53 of 53 samples), desmoplakin I (DPI I; five of five), carcinoembryonic antigen (CEA; five of 19), erb-B2 (five of seven), erb-B3 (six of seven), prostate-specific membrane antigen (PSM; four of nine), and CK18 (five of seven). Only PSA mRNA was not detected in any of the 53 control BM samples. In serial dilution experiments, the PSA RT-PCR assay was able to detect five LNCaP prostate carcinoma cells in 4 x 10(6) BM cells. CK-positive cells were found in 20 patients (37.7%) with prostate cancer, while PSA mRNA was found in only 15 (28.3%; P = .04). Moreover, despite the recent observation that PSA is also expressed in mammary carcinomas, none of the 10 CK-positive BM samples were PSA mRNA-positive. CONCLUSION: Limiting factors in the detection of micrometastatic tumor cells by RT-PCR are (1) the illegitimate transcription of tumor-associated or epithelial-specific genes in hematopoietic cells, and (2) the deficient expression of the marker gene in micrometastatic tumor cells.