Centrality index scoring provides a clinically useful measure of tumor centrality. This system may allow improved clinical and radiological assessment of kidney tumors, and improved reporting of quantitative tumor site.

No abstract

Mammalian target of rapamycin (mTOR) signaling has been associated with aggressive tumor growth in many cancer models, although its role in urothelial carcinoma (UCC) has not been extensively explored. Expression of phosphorylated mTOR (P-mTOR) and a downstream target, ribosomal S6 protein (P-S6), was identified in 74% (90/121) and 55% (66/121) of muscle-invasive UCCs, respectively. P-mTOR intensity and %positive cells were associated with reduced diseasespecific survival (P ‫؍‬ 0.04, P ‫؍‬ 0.08, respectively). Moreover, P-mTOR intensity corresponded to increased pathological stage (P < 0.01), and mTOR activity was associated with cell migration in vitro. In addition, mTOR inhibition via rapamycin administration reduced cell proliferation in UCC cell lines RT4, T24, J82, and UMUC3 in a dose-dependent manner to 6% of control levels and was significant at 1 nmol/L in J82, T24, and RT4 cells (P < 0.01, P < 0.01, P ‫؍‬ 0.03, respectively) and at 10 nmol/L in UMUC3 cells (P ‫؍‬ 0.03). Reduced proliferation corresponded with reduced P-S6 levels by Western blot, and effects were ablated by pretreatment of cells with mTOR-specific siRNA. No effects of rapamycin on apoptosis were identified by TUNEL labeling or PARP cleavage. Administration of rapamycin to T24-xenografted mice resulted in a 55% reduction in tumor volume (P ‫؍‬ 0.03) and a 40% reduction in proliferation (P < 0.01) compared with vehicle-injected mice. These findings indicate that mTOR pathway activation frequently occurs in UCC and that mTOR inhibition may be a potential means to reduce UCC growth. (Am J Pathol

Human epidermal growth factor receptor-2 (HER2) is a well-recognized growth-promoting factor in cancer, although its application to urothelial carcinoma has been limited because of a low frequency of gene amplification. We evaluated HER2 protein expression and gene amplification in micropapillary carcinoma, a rare but highly aggressive variant of urothelial carcinoma by dual-color in situ hybridization. Gene amplification was defined by a HER2:CHR17 ratio of Z2.2; low and high levels of amplification were further defined as o2.5 and Z2.5, respectively. Immunohistochemistry was used to determine HER2 protein expression using the American Society of Clinical Oncology/College of American Pathologists Guidelines of HER2 staining. Protein expression, gene amplification, and chromosome 17 aneusomy were compared by Jonchkeere-Terpstra and Cochran-Armitage trend tests. In all, 19 of the 20 micropapillary carcinoma samples yielded usable dual-color in situ hybridization and immunohistochemistry results for evaluation. Overall, 68% (n ¼ 13) demonstrated HER2 protein expression of 2 þ to 3 þ staining. Gene amplification was present in 42% of samples (n ¼ 8), with 100% correlation with 2 þ and 3 þ protein expression. Gene amplification and protein expression were significantly associated (P ¼ 0.01). Overall, 53% of samples (n ¼ 10) had aneusomy of chromosome 17. Chromosome 17 aneusomy was present in approximately half of the samples evaluated, suggesting inherent genomic instability in this variant of urothelial carcinoma. However, increased HER2:CHR17 ratios demonstrate increased HER2 expression due to amplification in the majority of micropapillary carcinomas. These results suggest that HER2-targeted therapy may be successful on the genomic level in patients with this disease.

The signaling networks regulating antimicrobial activity during urinary tract infection (UTI) are incompletely understood. Interleukin-6 (IL-6) levels increase with UTI severity, but the specific contributions of IL-6 to host immunity against bacterial uropathogens are unknown. To clarify this we tested whether IL-6 activates the Stat3 transcription factor, to drive a program of antimicrobial peptide gene expression in infected urothelium during UTI. Transurethral inoculation of uropathogenic Escherichia coli led to IL-6 secretion, urothelial Stat3 phosphorylation, and activation of antimicrobial peptide transcription, in a Toll-like receptor 4-dependent manner in a murine model of cystitis. Recombinant IL-6 elicited Stat3 phosphorylation in primary urothelial cells in vitro, and systemic IL-6 administration promoted urothelial Stat3 phosphorylation and antimicrobial peptide expression in vivo. IL-6 deficiency led to decreased urothelial Stat3 phosphorylation and antimicrobial peptide mRNA expression following UTI, a finding mirrored by conditional Stat3 deletion. Deficiency in IL-6 or Stat3 was associated with increased formation of intracellular bacterial communities, and exogenous IL-6 reversed this phenotype in IL-6 knockout mice. Moreover, chronic IL-6 depletion led to increased renal bacterial burden and severe pyelonephritis in C3H/HeOuJ mice. Thus, IL-6/Stat3 signaling drives a transcriptional program of antimicrobial gene expression in infected urothelium, with key roles in limiting epithelial invasion and ascending infection.