Inactive ERBB Receptors Cooperate With Reactive Oxygen Species To Suppress Cancer Progression

The ERBB receptors are a family of heterodimerization partners capable of driving transformation and metastasis. While the therapeutic targeting of single receptors has proven efficacious, optimal targeting of this receptor family should target all oncogenic members simultaneously. The juxtamembrane domains of ERBB1, ERBB2, and ERBB3 are highly conserved and control various aspects of ERBB-dependent biology. In an effort to block those functions, we have targeted this domain with decoy peptides synthesized in tandem with a cell-penetrating peptide, termed EJ1. Treatment with EJ1 induces cell death, promotes the formation of inactive ERBB multimers, and results in simultaneous reduction of ERBB1, ERBB2, and ERBB3 activation. Treatment also results in the activation of myosin light chain–dependent cell blebbing while inactivating CaMKII signaling, coincident with the induction of cell death. EJ1 also directly translocates to mitochondria, correlating with a loss of mitochondrial membrane potential and production of reactive oxygen species. Finally, treatment of a mouse model of breast cancer with EJ1 results in the inhibition of tumor growth and metastasis without associated toxicities in normal cells. Overall, these data demonstrate that a portion of the ERBB jxm domain, when used as an intracellular decoy, can inhibit tumor growth and metastasis, representing a novel anticancer therapeutic.     

Medullary thymic epithelial cell depletion leads to autoimmune hepatitis

TRAF6, an E3 ubiquitin protein ligase, plays a critical role in T cell tolerance by regulating medullary thymic epithelial cell (mTEC) development. mTECs regulate T cell tolerance by ectopically expressing self-antigens and eliminating autoreactive T cells in the thymus. Here we show that mice with mTEC depletion due to conditional deletion of Traf6 expression in murine thymic epithelial cells (Traf6ΔTEC mice) showed a surprisingly narrow spectrum of autoimmunity affecting the liver. The liver inflammation in Traf6ΔTEC mice exhibited all the histological and immunological characteristics of human autoimmune hepatitis (AIH). The role of T cells in AIH establishment was supported by intrahepatic T cell population changes and AIH development after transfer of liver T cells into immunodeficient mice. Despite a 50% reduction in natural Treg thymic output, peripheral tolerance in Traf6ΔTEC mice was normal, whereas compensatory T regulatory mechanisms were evident in the liver of these animals. These data indicate that mTECs exert a cell-autonomous role in central T cell tolerance and organ-specific autoimmunity, but play a redundant role in peripheral tolerance. These findings also demonstrate that Traf6ΔTEC mice are a relevant model with which to study the pathophysiology of AIH, as well as autoantigen-specific T cell responses and regulatory mechanisms underlying this disease.     

Erratum: Analysis of Infections Occurring in Breast Cancer Patients after Breast Conserving Surgery Using Mesh

[This corrects the article on p. 328 in vol. 14, PMID: 22323921.].     

Meta‐analysis of simultaneous versus staged resection for synchronous colorectal liver metastases

Aim: There is no clear consensus on the optimal timing of surgical resection for synchronous colorectal liver metastases (SCLM). This study is a meta‐analysis of the available evidence. Methods: Systematic review and meta‐analysis of trials comparing outcomes following simultaneous resection with staged resection for SCLM published from 1990 to 2010 in PubMed, Embase, Ovid and Medline. Pooled odds ratios (OR) or weighted mean differences (WMD) with 95% confidence intervals (95% CI) were calculated using either the fixed effects or random effects model. Results: Nineteen non‐randomized controlled trials (NRCT) studies were included in this analysis. These studies included a total of 2724 patients: 1116 underwent simultaneous resection and 1608 underwent staged resection. Meta‐analysis showed that shorter hospital stay (P < 0.001) and lower total complication rate (P < 0.001) were observed in patients undergoing simultaneous resection group. The overall survival rate in the simultaneous resection group did not statistically differ with that in the staged resection group at 1 year (P = 0.13), 3 years (P = 0.26), 5 years (P = 0.38), as well as the 1, 3 and 5 years disease‐free survival rates (respectively, P = 0.55; P = 0.16; P = 0.12). No significant difference was noted between the two groups in terms of mortality (P = 0.16), intraoperative blood loss (P = 0.06) and recurrence (P = 0.47). Conclusion: Simultaneous resection is safe and efficient in the treatment of patients with SCLM while avoiding a second laparotomy. In selected patients, simultaneous resection might be considered as the preferred approach. However, the findings have to be carefully interpreted due to the lower level of evidence and the existence of heterogeneity.