Understanding the role of the tumor microenvironment during cancer progression and metastasis is complicated by interactions between cells, the extracellular matrix (ECM), and a variety of biomolecules. Using a synthetic strategy, we investigated proteolytic modes of migration for HT-1080 fibrosarcoma cells in an environment that limited confounding extracellular influences. A large percentage of HT-1080s migrated through a Rho kinase (ROCK)-dependent rounded morphology with a leading edge protrusion that defined the direction of migration, and migration was only weakly dependent on the adhesive peptide RGDS. HT-1080s migrating in thiol-ene hydrogels are more rounded and exhibit much more invasive behavior than dermal fibroblasts. Our results indicate that HT-1080s have the capacity to migrate through a mechanism that is distinct from mesenchymal cells, with significant amoeboid character even when utilizing a proteolytic migration strategy. The migration mode observed here provides insight into the invasiveness of metastatic cells in vivo and demonstrates the potential of a synthetic strategy for investigating complex biological problems.
Objective-Uterine leiomyoma produce an extracellular matrix (ECM) that is abnormal in its volume, content, and structure. Alterations in ECM can modify mechanical stress on cells, leading to activation of Rho-dependent signaling. Here we sought to determine whether the altered ECM produced by leiomyoma was accompanied by an altered state of mechanical homeostasis.Study Design-Measurement of the mechanical response in paired leiomyoma and myometrium, immunogold, confocal microscopy, and immunohistochemical analyses.Results-Leiomyoma were significantly stiffer than matched myometrium. The increased stiffness was associated with a moderate increase in total sulfated glycosaminoglycan content and a slight increase in hydroxyproline. Levels of the Rho-GEF, AKAP13, were increased and subcellular localization was altered in leiomyoma. Phosphorylation of p38MAPK was greater in leiomyoma extracts. Conclusions-Leiomyoma
We conclude that normal changes in the pelvis after uncomplicated term vaginal delivery include enlargement of the uterus, intrauterine blood, widening of the symphysis and sacroiliac joints, and gas in the sacroiliac joints.
Here, we describe an engineering approach to quantitatively compare migration, morphologies, and adhesion for tumorigenic human fibrosarcoma cells (HT-1080s) and primary human dermal fibroblasts (hDFs) with the aim of identifying distinguishing properties of the transformed phenotype. Relative adhesiveness was quantified using self-assembled monolayer (SAM) arrays and proteolytic 3-dimensional (3D) migration was investigated using matrix metalloproteinase (MMP)-degradable poly(ethylene glycol) (PEG) hydrogels (“synthetic extracellular matrix” or “synthetic ECM”). In synthetic ECM, hDFs were characterized by vinculin-containing features on the tips of protrusions, multipolar morphologies, and organized actomyosin filaments. In contrast, HT-1080s were characterized by diffuse vinculin expression, pronounced β1-integrin on the tips of protrusions, a cortically-organized F-actin cytoskeleton, and quantitatively more rounded morphologies, decreased adhesiveness, and increased directional motility compared to hDFs. Further, HT-1080s were characterized by contractility-dependent motility, pronounced blebbing, and cortical contraction waves or constriction rings, while quantified 3D motility was similar in matrices with a wide range of biochemical and biophysical properties (including collagen) despite substantial morphological changes. While HT-1080s were distinct from hDFs for each of the 2D and 3D properties investigated, several features were similar to WM239a melanoma cells, including rounded, proteolytic migration modes, cortical F-actin organization, and prominent uropod-like structures enriched with β1-integrin, F-actin, and melanoma cell adhesion molecule (MCAM/CD146/MUC18). Importantly, many of the features observed for HT-1080s were analogous to cellular changes induced by transformation, including cell rounding, a disorganized F-actin cytoskeleton, altered organization of focal adhesion proteins, and a weakly adherent phenotype. Based on our results, we propose that HT-1080s migrate in synthetic ECM with functional properties that are a direct consequence of their transformed phenotype.
Human mesenchymal stem cells (hMSCs) are effective in treating disorders resulting from an inflammatory or heightened immune response. The hMSCs derived from induced pluripotent stem cells (ihMSCs) share the characteristics of tissue derived hMSCs but lack challenges associated with limited tissue sources and donor variation. To meet the expected future demand for ihMSCs, there is a need to develop scalable methods for their production at clinical yields while retaining immunomodulatory efficacy. Herein, we describe a platform for the scalable expansion and rapid harvest of ihMSCs with robust immunomodulatory activity using degradable gelatin methacryloyl (GelMA) microcarriers. GelMA microcarriers were rapidly and reproducibly fabricated using a custom microfluidic step emulsification device at relatively low cost. Using vertical wheel bioreactors, 8.8 to 16.3-fold expansion of ihMSCs was achieved over 8 days.Complete recovery by 5-minute digestion of the microcarriers with standard cell dissociation reagents resulted in >95% viability. The ihMSCs matched or exceeded immunomodulatory potential in vitro when compared with ihMSCs expanded on monolayers. This is the first description of a robust, scalable, and cost-effective method for generation of immunomodulatory ihMSCs, representing a significant contribution to their translational potential.
Here, we demonstrate the flexibility of peptide-functionalized poly(ethylene glycol) (PEG) hydrogels for modeling tumor progression. The PEG hydrogels were formed using thiol-ene chemistry to incorporate a matrix metalloproteinase-degradable peptide crosslinker (KKCGGPQG↓IWGQGCKK) permissive to proteolytic remodeling and the adhesive CRGDS peptide ligand. Tumor cell function was investigated by culturing WM239A melanoma cells on PEG hydrogel surfaces or encapsulating cells within the hydrogels, and either as monocultures or indirect (non-contact) cocultures with primary human dermal fibroblasts (hDFs). WM239A cluster size and proliferation rate depended on the shear elastic modulus for cells cultured on PEG hydrogels, while growth was inhibited by coculture with hDFs regardless of hydrogel stiffness. Cluster size was also suppressed by hDFs for WM239A cells encapsulated in PEG hydrogels, which is consistent with cells seeded on top of hydrogels. Notably, encapsulated WM239A clusters and single cells adopted invasive phenotypes in the hDF coculture model, which included single cell and collective migration modes that resembled invasion from human melanoma patient-derived xenograft tumors encapsulated in equivalent PEG hydrogels. Our combined results demonstrate that peptide-functionalized PEG hydrogels provide a useful platform for investigating aspects of tumor progression in 2D and 3D microenvironments, including single cell migration, cluster growth and invasion.
Two antigen detection systems (MicroTrak [MT], Syva Co., Palo Alto, Calif.; and Chlamydiazyme [CZ], Abbott Laboratories, North Chicago, Ill.) were compared with semiquantitative culture for diagnosis of chlamydial infection in 1,059 patients. Cultures were done on microtiter plates and blind passaged once. Culture-negative but CZor MT-positive specimens were recultured. True positives were positive by either initial or repeat cultures. Of 827 nonpregnant and 231 pregnant patients, 9.1 and 12.1%, respectively, had positive cultures. Overall sensitivity of the initial culture was 48.5% without passage and 86.4% with passage. The sensitivity of CZ was 67%. The sensitivity of MT in our laboratory was 50%; however, further review of these specimens by Syva employees gave a combined sensitivity of 71.6%. MT and CZ were more sensitive for pregnant patients (MT, 84.6%; CZ, 85.7%) than for nonpregnant patients (MT, 65.5%; CZ, 60.0%). Ail the tests had specificities above 95%. Of the specimens that were positive after initial culture without subculture, MT-negative specimens had a mean of 3.7 inclusions in culture, and MT-positive specimens had a mean of 24.8 (P = 0.002); CZ-negative specimens had a mean of 4.3 inclusions, and CZ-positive specimens had a mean of 20.0 (P = 0.026). In addition, cultures of specimens from pregnant patients had more inclusions than did those from gynecology patients, but this was not statistically significant (P = 0.096). No method is ideal; however, MT and CZ were less sensitive than was this culture system for detecting chlamydial infection in patients in gynecology clinics and were of comparable sensitivity for pregnant patients.
Despite claims that exposure to fragranced products may trigger ocular and respiratory symptoms among asthmatics, we found no evidence that 30 min of exposure to one of two fragranced aerosols elicited objective adverse effects in the ocular or nasal mucosa of mild and moderate asthmatics. While physiological mechanisms of fragrance impact may yet be responsible for some of the adverse reports among asthmatics following fragrance exposure, such reports may also reflect a non-physiological locus of symptom perception triggered by other sensory cues.
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