Invasion/chemotaxis- and extravasation-chip models for breast cancer bone metastasis.

Bone is one of the most frequently targeted organs in metastatic cancers including the breast. Breast cancer bone metastasis often results in devastating outcomes as limited treatment options are currently available. Therefore, innovative methods are needed to provide earlier detection and thus better treatment and prognosis. Here, we present a new approach to model bone-like microenvironments to detect invasion and extravasation of breast cancer cells using invasion/chemotaxis (IC-) and extravasation (EX-) chips, respectively. Our results show that the behaviors of MDA-MB-231 breast cancer cells on IC- and EX-chip models correlate with their in vivo metastatic potential. Our culture model constitutes cell lines representing osteoblasts, bone marrow stromal cells, and monocytes embedded in three-dimensional (3D) collagen I-based extracellular matrices of varying composition and stiffness. We show that collagen I offers a better bone-like environment for bone cells and matrix composition and stiffness regulate the invasion of breast cancer cells. Using in situ contactless rheological measurements under cell culture conditions, we show that the presence of cells increased the stiffness values of the matrices up to 1200 Pa when monitored for five days. This suggests that the cellular composition has a significant effect on regulating matrix mechanical properties, which in turn contribute to the invasiveness. The platforms we present here enable the investigation of the underlying molecular mechanisms in breast cancer bone metastasis and provide the groundwork of developing preclinical tools for the prediction of bone metastasis risk.

c-Met activation promotes extravasation of hepatocellular carcinoma cells into 3D-cultured hepatocyte cells in lab-on-a-chip device.

Activation of c-Met signaling is associated with an aggressive phenotype and poor prognosis in hepatocellular carcinoma (HCC); however, its contribution to organ preference in metastasis remains unclear. In this study, using a Lab on a Chip device, we defined the role of aberrant c-Met activation in regulating the extravasation and homing capacity of HCC cells. Our studies showed that (i) c-Met overexpression and activation direct HCC cells preferentially towards the hepatocytes-enriched microenvironment, and (ii) blockage of c-Met phosphorylation by a small molecule inhibitor attenuated extravasation and homing capacity of HCC cells. These results, thus, demonstrate the role of c-Met signaling in regulating the colonization of HCC cells preferentially in the liver.

Cancer Stem Cells in Tumor Modeling: Challenges and Future Directions.

Microfluidic tumors-on-chips models have revolutionized anticancer therapeutic research by creating an ideal microenvironment for cancer cells. The tumor microenvironment (TME) includes various cell types and cancer stem cells (CSCs), which are postulated to regulate the growth, invasion, and migratory behavior of tumor cells. In this review, the biological niches of the TME and cancer cell behavior focusing on the behavior of CSCs are summarized. Conventional cancer models such as three-dimensional cultures and organoid models are reviewed. Opportunities for the incorporation of CSCs with tumors-on-chips are then discussed for creating tumor invasion models. Such models will represent a paradigm shift in the cancer community by allowing oncologists and clinicians to predict better which cancer patients will benefit from chemotherapy treatments.

On-chip determination of tissue-specific metastatic potential of breast cancer cells.

Metastasis is one of the major obstacles for breast cancer patients. Limitations of current models demand the development of custom platforms to predict metastatic potential and homing choices of cancer cells. Here, two organ-on-chip platforms, invasion/chemotaxis (IC-chip) and extravasation (EX-chip) were used for the quantitative assessment of invasion and extravasation towards specific tissues. Lung, liver and breast microenvironments were simulated in the chips using tissue-specific cells embedded in matrigel. In the IC-chip, invasive MDA-MB-231, but not noninvasive MCF-7 breast cancer cells invaded into lung and liver microenvironments. In the EX-chip, MDA-MB-231 cells extravasated more into the lung compared to the liver and breast microenvironments. In addition, lung-specific MDA-MB-231 clone invaded and extravasated into the lung microenvironment more efficiently than the bone-specific clone. Both invasion/chemotaxis and extravasation results were in agreement with published clinical data. Collectively, our results show that IC-chip and EX-chip, simulating tissue-specific microenvironments, can distinguish different in vivo metastatic phenotypes, in vitro. Determination of tissue-specific metastatic potential of breast cancer cells is expected to improve diagnosis and help select the ideal therapy.

Role of Point-of-Care Lung and Inferior Vena Cava Ultrasound in Clinical Decisions for Patients Presenting to the Emergency Department With Symptoms of Acute Decompensated Heart Failure.

OBJECTIVES: This prospective study was performed to evaluate the diagnostic role of point-of-care lung ultrasound (LUS) and inferior vena cava (IVC) ultrasound in patients with acute decompensated heart failure (ADHF). METHODS: A prospective cohort study was conducted between January 2018 and November 2018 on patients with a diagnosis of ADHF in the emergency department (ED). On admission, LUS findings, inspiratory and expiratory IVC diameters, and the inferior vena cava collapsibility index (IVCCI) were obtained. After therapeutic interventions, third-hour changes in LUS and the IVC index and the treatment response were assessed. RESULTS: Eighty patients were enrolled. Forty-six (58%) patients had an ejection fraction (EF) greater than 40%, and 34 (42%) had an EF of less than 40%. Significant differences were detected between the admission and third-hour inspiratory IVC diameter, expiratory IVC diameter, and IVCCI (P = .001). There was no correlation between the EF and inspiratory IVC diameter (r = -0.03; P = .976), expiratory IVC diameter (r = -109; P = .336), or IVCCI (r = -0.72; P = .523) and between the B-type natriuretic peptide level and inspiratory IVC diameter (r = -0.58; P = .610), expiratory IVC diameter (r = -0.33; P = .774), or IVCCI (r = -0.78; P = .493) either. A comparison of admission and third-hour numbers of B-lines on LUS imaging showed a significant decrease in the number of B-lines in all zones at the end of 3 hours (P = .001). A significant difference existed between the hospitalized and discharged patients with respect to IVC diameters and number of B-lines. CONCLUSIONS: In the ED setting, an assessment of B-lines and measurement of IVC diameters are better markers than the B-type natriuretic peptide level, EF, or chest x-ray for diagnosis of ADHF and can be used to make decisions for hospitalization or discharge from the ED.

Breast cancer cells and macrophages in a paracrine-juxtacrine loop.

Breast cancer cells (BCC) and macrophages are known to interact via epidermal growth factor (EGF) produced by macrophages and colony stimulating factor-1 (CSF-1) produced by BCC. Despite contradictory findings, this interaction is perceived as a paracrine loop. Further, the underlying mechanism of interaction remains unclear. Here, we investigated interactions of BCC with macrophages in 2D and 3D. While both BCC and macrophages showed invasion/chemotaxis to fetal bovine serum, only macrophages showed chemotaxis to BCC in custom designed 3D cell-on-a-chip devices. These results were in agreement with gradient simulation results and ELISA results showing that macrophage-derived-EGF was not secreted into macrophage-conditioned-medium. Live cell imaging of BCC in the presence and absence of iressa showed that macrophages but not macrophage-derived-matrix modulated adhesion and motility of BCC in 2D. 3D co-culture experiments in collagen and matrigel showed that BCC changed their multicellular organization in the presence of macrophages. In custom designed 3D co-culture cell-on-a-chip devices, macrophages promoted and reduced migration of BCC in collagen and matrigel, respectively. Furthermore, adherent but not suspended BCC endocytosed EGFR when in contact with macrophages. Collectively, our data revealed that macrophages showed chemotaxis towards BCC whereas BCC required direct contact to interact with macrophage-derived-EGF. Therefore, we propose that the interaction between cancer cells and macrophages is a paracrine-juxtacrine loop of CSF-1 and EGF, respectively.

Comparison of the Effects of Cigarette Smoking on Male and Female Vocal Folds.

OBJECTIVE: To investigate effects of smoking cigarette on male and female larynges and compare them. METHOD: Eighteen adult Wistar Albino rats were included to study; 9 were male and 9 female. The exposure groups each contained 6 rats, and the control groups 3 rats. Six male constituted group 1 and 6 female constituted group 2. Group 1 and 3 were exposed to smoke. Group 2 and 4 were composed of 3 males and 3 females, respectively. Smoke from 10 cigarettes was delivered in each of the morning and afternoon daily for 1 month. At the end of 4 weeks, all rats were sacrificed and their larynges were evaluated histopathologically. RESULTS: Microscobic evaluation of epithelium of vocal folds revealed no significant difference between study groups. There was also no difference between study and control groups. Subepitelial tissue showed no difference between study groups but angiogenesis and inflammation were higher in study groups. Epithelial analysis of false vocal folds showed significant difference between study groups. Female epithelium showed more hyperplastic and metaplastic changes. CONCLUSION: Cigarette smoke damaged both the vocal folds and false vocal folds. The female false vocal folds were more susceptible to damage than the males.

Cellular distribution of invadopodia is regulated by nanometer scale surface protein patterns.

Invadopodia are proteolytic structures formed by cancer cells. It is not known whether their cellular distribution can be regulated by the organization of the extracellular matrix or the organization of the golgi complex or whether they have an adhesion requirement. Here, we used electron beam lithography to fabricate fibronectin (FN) nanodots with isotropic and gradient micrometer scale spacings on K-casein and laminin backgrounds. Investigating cancer cells cultured on protein nanopatterns, we showed that (i) presence of FN nanodots on a K-casein background decreased percent of cells with neutral invadopodia polarization compared to FN control surfaces; (ii) presence of a gradient of FN nanodots on a K-casein background increased percent of cells with negative invadopodia polarization compared to FN control surfaces; (iii) polarization of the golgi complex was similar to that of invadopodia in agreement with a spatial link; (iv) local adhesion did not necessarily appear to be a prerequisite for invadopodia formation.

Diagnostic Value and Effect of Bedside Ultrasound in Acute Appendicitis in the Emergency Department.

OBJECTIVE: Early and accurate diagnosis of acute appendicitis (AA) with ultrasound (US) can minimize the morbidity and mortality of the patients. In this regard, US can help emergency physicians (EPs) in the diagnosing process and clinical decision making for AA. Therefore, we primarily aimed to evaluate the effectiveness of point-of-care US (POCUS) in clinical decision making of EPs for the diagnostic evaluation for AA in the emergency department (ED). METHODS: The study sample consisted of patients aged > 18 years who presented to the ED with abdominal pain and underwent diagnostic evaluation for AA. All patients were examined initially with POCUS by EPs and then with radiology-performed US (RADUS) by radiologists. Pre- and post-POCUS median diagnostic certainty values (MDCVs) for AA were determined with visual analog scale (VAS) scores (0 = not present, 100 = certainly present) by POCUS performers. Definitive diagnoses were determined by surgery, pathologic evaluation of appendectomy specimens, or clinical follow-up results. The sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) for POCUS and RADUS together with pre- and post-POCUS VAS scores for MDCVs were compared. RESULTS: A total of 264 patients were included into the final analysis and 169 (64%) had a diagnosis of AA. The sensitivity, specificity, PLR, and NLR of US examinations were 92.3% (95% confidence interval [CI] = 87.2%-95.8%), 95.8% (89.5%-98.8%), 21.9 (8.4-57.2), and 0.08 (0.05-0.1) for POCUS and 76.9% (69.8-83%), 97.8% (84.9-99.7%), 36.4 (9.25-144.3), and 0.24 (0.18-0.31) for RADUS, respectively. Pre-POCUS and post-POCUS VAS scores for MDCVs were 60 (interquartile range [IQR] = 50-65) and 95 (IQR = 20-98), respectively (p = 0.000). CONCLUSION: Point-of-care ultrasonography, when performed in ED for the diagnosis of AA, has high sensitivity and specificity and had a positive impact on the clinical decision making of EPs.