B6 Mouse Strain: The Best Fit for LPS-Induced Interstitial Cystitis Model.

Interstitial cystitis (IC) is a chronic inflammatory disease characterized by bladder pain and increased urinary frequency. Although the C57BL/6J (B6) and FVB/NJ (FVB) mouse strains are commonly used as animal models for studies involving the urinary system, few reports have compared their lower urinary tract anatomy, despite the importance of such data. Our study aimed to characterize bladder function changes in FVB and B6 mouse strains with lipopolysaccharide (LPS)-induced IC, to understand mouse model-based bladder research. The bladder function parameters were measured by cystometrogram. Histological assay was examined by hematoxylin and eosin stain, Masson's trichrome stain, and immunofluorescence staining. Results indicated that the two strains in the control group exhibited different bladder structures and functions, with significant anatomical differences, including a larger bladder size in the FVB than in the B6 strain. Furthermore, cystometry tests revealed differences in bladder function pressure. LPS-treated B6 mice presented significant changes in peak pressure, with decreased intercontraction intervals; these results were similar to symptoms of IC in humans. Each strain displayed distinct characteristics, emphasizing the care required in choosing the appropriate strain for bladder-model studies. The results suggested that the B6 mouse strain is more suitable for IC models.

Effect of Dietary Omega-3 Fatty Acids on Tumor-Associated Macrophages and Prostate Cancer Progression.

BACKGROUND: Preclinical and clinical studies suggest that a fish oil-based diet may play a role in delaying the progression of prostate cancer through a number of different mechanisms involving inflammatory pathways. Given the importance of tumor-associated macrophages (TAMs) in carcinogenesis, we hypothesized that a fish oil-based diet will inhibit TAM infiltration and delay the growth of prostate cancer. METHODS: Androgen sensitive mouse prostate cancer (MycCaP) allograft tumors were grown in fully immunocompetent FVB mice fed a high- fat fish oil (omega-3) or corn oil (omega-6) diet. Gene expression of markers for immune cell populations, cytokines, chemokines, and signaling pathways were determined by real-time PCR and western blot in tumor tissue. Cell proliferation and apoptosis in vitro were measured by MTS assay and flow cytometry. RESULTS: Tumor volumes were significantly smaller in mice in ω-3 versus the ω-6 group (P = 0.048). Gene expression of markers for M1 and M2 macrophages (F4/80, iNOS, ARG1), associated cytokines (IL-6, TNF alpha, IL-10), and the chemokine CCL-2 were also lower in the omega-3 group. Correlative in vitro studies were performed in M1 and M2 polarized macrophages and mirrored the in vivo findings. Dietary fish oil and in vitro omega-3 fatty acid administration reduced protein expression of transcription factors in the nuclear factor kappa B pathway leading to a significant decrease in gene expression of downstream targets (Bcl-2, BCL-XL, XIAP, survivin) in MycCap cells. CONCLUSIONS: These findings underscore the potential of fish oil in modulating the clinical course of human prostate cancer through the immune system. Further preclinical and clinical studies are warranted evaluating fish oil-based therapies for inhibiting the recruitment and function of M1 and M2 tumor infiltrating macrophages. Prostate 76:1293-1302, 2016. © 2016 Wiley Periodicals, Inc.

Modeling Human Prostate Cancer Metastasis in Mice via Resection of Subcutaneous Allografts.

The 5-year survival rate for patients diagnosed with distant metastatic prostate cancer in the United States is 30.6%. Therefore, there is a great need to develop in vivo model systems to study prostate cancer metastasis and to test potential therapeutics. Most murine prostate cancer metastatic models involve intracardiac or intraosseous implantation of cancer cells, which bypass the early stages of tumor cell migration and invasion. Herein we provide a detailed protocol for a novel method of resecting subcutaneous prostate cancer allografts in immunocompetent mice to produce spontaneous metastases and describe a pilot study using this method of tumor resection. Intact male FVB/NCrl mice (n = 9) were inoculated subcutaneously with Myc-CaP cells. Tumors were surgically resected, and mice were monitored for tumor recurrence. Animals were euthanized or died, and a full set of tissues was collected for histopathologic examination. Tumors took an average of 44 days (range 23-61) to reach 1.7 cm in any direction. All tumors were resectable, and resection of the tumors increased the study length by 70 days (range 30-121). One mouse was euthanized early of an unrelated cause, and of eight remaining mice, four developed tumor recurrence at the site of resection. One mouse developed bone metastases, one mouse developed metastases to the abdominal cavity, and two mice showed signs of local invasion. This study demonstrates that resection of subcutaneous Myc-CaP cell allografts in mice results in local tumor recurrence and the development of distant metastases, providing a new model system to study prostate cancer metastasis in vivo.

Liquid chromatography-tandem mass spectrometry assay for the EGFR inhibitor pelitinib in plasma.

A bioanalytical liquid chromatography-tandem mass spectrometry assay for the tyrosine kinase inhibitor pelitinib was developed and validated in plasma. Acetonitrile containing the internal standard erlotinib was used to precipitate proteins. The extract was diluted with water and then directly injected onto the sub-2µm particle, bridged ethylsilica hybrid trifunctional bonded C18 column. A gradient consisting of 0.02% (v/v) formic acid in a methanol-water mixture was used. The ionization mode of the electrospray interface was positive and the analyte was detected by a triple quadrupole mass spectrometer in the selected reaction monitoring mode. The calibration range of the assay was 1-200ng/ml. The within day precision, the between day precision, and the accuracy were 3.5-7.4%, 4.5-8.6%, and 94.0-104.8%, respectively. The stability of the drug was sufficient under all relevant conditions. The validated assay was used to measure drug levels in wild-type FVB mice and pharmacokinetic parameters were assessed.