Her2 alterations in muscle-invasive bladder cancer: Patient selection beyond protein expression for targeted therapy.

Although the introduction of novel targeted agents has improved patient outcomes in several human cancers, no such advance has been achieved in muscle-invasive bladder cancer (MIBC). However, recent sequencing efforts have begun to dissect the complex genomic landscape of MIBC, revealing distinct molecular subtypes and offering hope for implementation of targeted therapies. Her2 (ERBB2) is one of the most established therapeutic targets in breast and gastric cancer but agents targeting Her2 have not yet demonstrated anti-tumor activity in MIBC. Through an integrated analysis of 127 patients from three centers, we identified alterations of Her2 at the DNA, RNA and protein level, and demonstrate that Her2 relevance as a tumor driver likely may vary even within ERBB2 amplified cases. Importantly, tumors with a luminal molecular subtype have a significantly higher rate of Her2 alterations than those of the basal subtype, suggesting that Her2 activity is also associated with subtype status. Although some of our findings present rare events in bladder cancer, our study suggests that comprehensively assessing Her2 status in the context of tumor molecular subtype may help select MIBC patients most likely to respond to Her2 targeted therapy.

Bcl-2 predicts response to neoadjuvant chemotherapy and is overexpressed in lymph node metastases of urothelial cancer of the bladder.

PURPOSE: To assess whether Bcl-2, an inhibitor of the apoptotic cascade, can predict response to neoadjuvant chemotherapy in patients with urothelial cancer of the bladder (UCB). METHODS: Bcl-2 expression was analyzed in 2 different tissue microarrays (TMAs). One TMA was constructed of primary tumors and their corresponding lymph node (LN) metastases from 152 patients with chemotherapy-naive UCB treated by cystectomy and pelvic lymphadenectomy (chemotherapy-naive TMA cohort). The other TMA was constructed of tumor samples obtained from 55 patients with UCB before neoadjuvant chemotherapy (transurethral resection of the bladder cancer) and after cystectomy with pelvic lymphadenectomy (residual primary tumor [ypT+], n = 38); residual LN metastases [ypN+], n = 24) (prechemotherapy/postchemotherapy TMA cohort). Bcl-2 overexpression was defined as 10% or more cancer cells showing cytoplasmic immunoreactivity. RESULTS: In both TMA cohorts, Bcl-2 overexpression was significantly (P<0.05) more frequent in LN metastases than in primary tumors (chemotherapy-naive TMA group: 18/148 [12%] in primary tumors vs. 39/143 [27%] in metastases; postchemotherapy TMA: ypT+7/35 [20%] vs. ypN+11/19 [58%]). In the neoadjuvant setting, patients with Bcl-2 overexpression in transurethral resection of the bladder cancer specimens showed significantly (P = 0.04) higher ypT stages and less regression in their cystectomy specimens than did the control group, and only one-eighth (13%) had complete tumor regression (ypT0 ypN0). In survival analyses, only histopathological parameters added significant prognostic information. CONCLUSIONS: Bcl-2 overexpression in chemotherapy-naive primary bladder cancer is related to poor chemotherapy response and might help to select likely nonresponders.

Quantitative expression of RIG-like helicase, NOD-like receptor and inflammasome-related mRNAs in humans and mice.

The cell-type-, organ- and species-specific expression of the surface and endosomally located Toll-like receptors are well described but little is known about the respective expression profiles of cytosolic pattern recognition molecules. We therefore determined the mRNA expression levels of 15 cytosolic pattern recognition molecules in 11 solid organs of human and mice. Human organs revealed lower mRNA levels of most molecules as in spleen but at least 2-fold higher were inflammasome-related NOD, leucine-rich repeat and pyrin domain-containing protein 1-3 (NLRP1-3) and -12 in brain, LGP2, retinoic acid-inducible gene I (RIG-I) and NLRP10 in liver, NLRP10 in small intestine, LGP2, RIG-I, NAIP, NLRP2 and -3 in testis and RIG-I, NLRP2 and -10 in muscle. In mice, most organs also expressed lower mRNA levels compared with spleen. Only NLRP6 in liver, NAIP and NLRP6 in small intestine, LGP2, nucleotide-binding oligomerization domain 1 (NOD1), NLRP1, -2, -6, -10 and -12 in colon and MDA5, RIG-I, NLRC4, NOD1, -2, NLRP1, -2, -6, -10 and -12 mRNA levels in kidney were higher. Resting human and mouse monocytes and T cells expressed most molecules and produced IL-1 beta and CCL5/RANTES upon activation. However, murine monocytes strongly up-regulated, whereas human monocytes down-regulated receptor expression upon activation. These data suggest that the cell-type-, organ- and species-specific expression and regulation need to be considered in the design and interpretation of related studies.

Lack of SIGIRR/TIR8 aggravates hydrocarbon oil-induced lupus nephritis.

Multiple genetic factors contribute to the clinical variability of spontaneous systemic lupus erythematosus (SLE) but their role in drug-induced SLE remain largely unknown. Hydrocarbon oil-induced SLE depends on mesothelial cell apoptosis and Toll-like receptor (TLR)-7-mediated induction of type I interferons. Hence, we hypothesized that TIR8/SIGIRR, an endogenous TLR inhibitor, prevents oil-induced SLE. Sigirr-deficient dendritic cells expressed higher TLR7 mRNA levels and TLR7 activation resulted in increased IL-12 production in vitro. In vivo, lack of SIGIRR increased surface CD40 expression on spleen CD11c(+) dendritic cells and MX-1, TNF, IL-12, BAFF and BCL-2 mRNA expression 6 months after pristane injection. Spleen cell counts of CD4(-)/CD8(-) 'autoreactive' T cells and B220(+) B cells were also increased in Sigirr(-/-) mice. Serum autoantibody analysis revealed that Sigirr deficiency specifically enhanced the production of rheumatoid factor (from 4 months of age) and anti-snRNP IgG (from 5 months of age), while anti-Smith IgG or anti-dsDNA IgG were independent of the Sigirr genotype. This effect was sufficient to significantly aggravate lupus nephritis in Sigirr-deficient mice. Structure model prediction identified the BB loop of SIGIRR's intracellular TIR domain to interact with TLR7 and MyD88. BB loop deletion was sufficient to completely abrogate SIGIRR's inhibitory effect on TLR7 signalling. Thus, TIR8/SIGIRR protects from hydrocarbon oil-induced lupus by suppressing the TLR7-mediated activation of dendritic cells, via its intracellular BB loop.