C57BL/6 mice are one of the most commonly used mouse strains in research, especially in kidney injury studies. However, C57BL/6 mice are resistant to chronic kidney disease-associated pathologies, particularly the development of glomerulosclerosis and interstitial fibrosis. Our lab and others developed a more clinically relevant dosing regimen of cisplatin (7 mg/kg cisplatin once a week for four weeks, mice euthanized at Day 24) that leads to the development of progressive kidney fibrosis in FVB/n mice. However, we found that treating C57BL/6 mice with this same dosing regimen does not result in kidney fibrosis. In this study, we demonstrate that increasing the dose of cisplatin to 9 mg/kg once a week for four weeks is sufficient to consistently induce fibrosis in C57BL/6 mice while maintaining animal survival. In addition, we present that cohorts of C57BL/6 mice purchased from Jackson one year apart and mice bred in house display variability in renal outcomes following repeated low dose cisplatin treatment. In depth analyses of this intra-animal variability revealed CCL2 as a marker of cisplatin-induced kidney injury through correlation studies. In addition, significant immune cell infiltration was observed in the kidney after four doses of 9 mg/kg cisplatin, contrary to what has been previously reported. These results indicate that multiple strains of mice can be used with our repeated low dose cisplatin model with dose optimization. Results also indicate that littermate control mice should be used with this model to account for population variability.

the tumor microenvironment (tMe) is composed of a heterogeneous biological ecosystem of cellular and non-cellular elements including transformed tumor cells, endothelial cells, immune cells, activated fibroblasts or myofibroblasts, stem and progenitor cells, as well as the cytokines and matrix that they produce. The constituents of the TME stroma are multiple and varied, however cancer associated fibroblasts (CAF) and their contribution to the TME are important in tumor progression. CAF are hypothesized to arise from multiple progenitor cell types, including mesenchymal stem cells. Currently, isolation of tMe stroma from patients is complicated by issues such as limited availability of biopsy material and cell stress incurred during lengthy adaptation to atmospheric oxygen (20% O2) in cell culture, limiting pre-clinical studies of patient tumor stromal interactions. Here we describe a microenvironment mimetic in vitro cell culturing system that incorporates elements of the in vivo lung environment, including lung fibroblast derived extracellular matrix and physiological hypoxia (5% O2). Using this system, we easily isolated and rapidly expanded stromal progenitors from patient lung tumor resections without complex sorting methods or growth supplements. These progenitor populations retained expression of pluripotency markers, secreted factors associated with cancer progression, and enhanced tumor cell growth and metastasis. An understanding of the biology of these progenitor cell populations in a tMe-like environment may advance our ability to target these cells and limit their effects on promoting cancer metastasis.

The complex interactions between subclinical changes to hepatic extracellular matrix (ECM) in response to injury and tumor-associated macrophage microenvironmental cues facilitating metastatic cell seeding remain poorly understood. This study implements a combined computational modeling and experimental approach to evaluate tumor growth following hepatic injury, focusing on ECM remodeling and interactions with local macrophages. Experiments were performed to determine ECM density and macrophage-associated cytokine levels. Effects of ECM remodeling along with macrophage polarization on tumor growth were evaluated via computational modeling. For primary or metastatic cells in co-culture with macrophages, TNF-α levels were 5× higher with M1 vs. M2 macrophages. Metastatic cell co-culture exhibited 10× higher TNF-α induction than with primary tumor cells. Although TGFβ1 induction was similar between both co-cultures, levels were slightly higher with primary cells in the presence of M1. Simulated metastatic tumors exhibited decreased growth compared to primary tumors, due to high local M1-induced cytotoxicity, even in a highly vascularized microenvironment. Experimental analysis combined with computational modeling may provide insight into interactions between ECM remodeling, macrophage polarization, and liver tumor growth.

Taxanes are a class of chemotherapeutic drug that act to disrupt microtubule function and cause mitotic arrest and cell death. These drugs are commonly used for cancer treatment, however their effectiveness is dependent on the presence of a functioning spindle assembly checkpoint (SAC). As a result, it is possible for cancer cells to become resistant to microtubule disrupting drugs by inactivating the SAC. The anaphase promoting complex/cyclosome (APC/C) is an E3 ubiquitin ligase that acts as the master regulator of cell cycle progression.Inhibition of the APC/C should result in disruption of the cell cycle, resulting in arrest during mitosis and/or pseudo-G1. Previous in silico studies of the APC/C structure identified compounds that potentially bind to the APC/C subunit ANAPC2. Three of these compounds (#8, 10, and 11) were tested on A2780/CP70 and SKOV3 ovarian carcinoma cells and tGM24 telomerase immortalized human fibroblasts. Cell morphology was observed during treatment with the compounds and showed signs of mitotic and apoptotic cells in a dose dependent manner. While all compounds showed the predicted effects, effects were more pronounced with compounds 10 and 11 than compound 8. Mitotic index determinations revealed a significant mitotic delay in both cancer cells and fibroblasts treated with compounds 8, 10, and 11. Compounds 10 and 11 were more potent than compound 8 in inhibition of colony forming ability for all three cell lines. Fibroblasts showed some resistance to compound 8, however fibroblasts exposed to compound 11 showed complete inhibition of cell growth without characteristic morphological signs of apoptosis. All three compounds induced apoptosis in ovarian cancer cells, as indicated by increased caspase 3 activity, but not in fibroblasts. These results indicate that compounds targeting the APC/C can induce mitotic arrest and kill ovarian cancer cells while sparing normal cells.

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