JNK signaling prevents biliary cyst formation through a CASPASE-8-dependent function of RIPK1 during aging.

The c-Jun N-terminal kinase (JNK) signaling pathway mediates adaptation to stress signals and has been associated with cell death, cell proliferation, and malignant transformation in the liver. However, up to now, its function was experimentally studied mainly in young mice. By generating mice with combined conditional ablation of Jnk1 and Jnk2 in liver parenchymal cells (LPCs) (JNK1/2LPC-KO mice; KO, knockout), we unraveled a function of the JNK pathway in the regulation of liver homeostasis during aging. Aging JNK1/2LPC-KO mice spontaneously developed large biliary cysts that originated from the biliary cell compartment. Mechanistically, we could show that cyst formation in livers of JNK1/2LPC-KO mice was dependent on receptor-interacting protein kinase 1 (RIPK1), a known regulator of cell survival, apoptosis, and necroptosis. In line with this, we showed that RIPK1 was overexpressed in the human cyst epithelium of a subset of patients with polycystic liver disease. Collectively, these data reveal a functional interaction between JNK signaling and RIPK1 in age-related progressive cyst development. Thus, they provide a functional linkage between stress adaptation and programmed cell death (PCD) in the maintenance of liver homeostasis during aging.

Intra-tumoral budding in preoperative biopsy specimens predicts lymph node and distant metastasis in patients with colorectal cancer.

Tumor budding, a histological hallmark of epithelial-mesenchymal transition in colorectal cancer, is a parameter of tumor progression and according to the International Union Against Cancer/American Joint Committee on Cancer an 'additional' prognostic factor. The current definition of tumor budding is reserved for the invasive tumor front of colorectal cancer (so called peri-tumoral budding), but tumor buds can also be observed in small preoperative biopsy specimens. Whereas the prognostic value of peri-tumoral budding assessed in resection specimens has found wide acceptance, the value of budding in preoperative biopsies, which normally do not encompass the invasive tumor margin and hence can be called intra-tumoral budding, has not been systematically investigated yet. Therefore, the aim of this study is to assess the predictive value of intra-tumoral budding for lymph node and distant metastasis in preoperative biopsies. Preoperative biopsy samples and consecutive resection specimens from 72 patients with pathological information on TNM stage, vascular, lymphatic and perineural invasion, and tumor border configuration were used to evaluate intra-tumoral budding and peri-tumoral budding. Both parameters were scored semiquantitatively as 'high' (detectable at low power magnification × 2.5) and 'low' (occasional budding at intermediate magnification × 10, difficult to find or absent). In biopsy samples high intra-tumoral budding was observed in 12/72 patients (17%) and associated with high peri-tumoral budding in the corresponding resection specimens (P=0.008). Additionally, there was a correlation between high intra-tumoral budding and lymph node metastasis (P=0.034), distant metastasis (P=0.007) and higher tumor grade (P=0.025). Peri-tumoral budding was associated with higher N stage (P=0.004), vascular (P=0.046) and lymphatic invasion (P=0.019) as well as with an infiltrating tumor border (P<0.001), reflecting the predictive power of peri-tumoral budding for tumor progression. High intra-tumoral budding in preoperative biopsy samples of colorectal cancer patients predicts high peri-tumoral budding at the invasive margin and lymph node metastasis in the corresponding resection specimens as well as distant metastasis.

Enterocolic lymphocytic phlebitis of the cecal pole and appendix vermiformis with increase of IgG4-positive plasma cells.

Here we describe the clinicopathological course of a 20-year-old female patient with enterocolic lymphocytic phlebitis (ELP) of the appendix vermiformis and cecal pole with increase of IgG4-positive plasma cells. The patient presented with acute abdomen, suspicious of acute appendicitis. Diagnostic laparoscopy showed tumefaction of the cecal pole and appendix vermiformis. Histologic examination revealed mural thickening and a dense lymphoplasmocytic, partly obliterative infiltrate of the veins with sparing of the arteries, diagnostic of ELP. In addition, we found an elevated number of IgG4-positive plasma cells blended in with the lymphocytes. The IgG4-to-IgG ratio accounted for >40 %. This case meets the histopathological criteria requested for IgG4-related disease (IgG4-RD) and thus opens the possibility that ELP might be part of the IgG4-RD spectrum.