Lineage fate of ductular reactions in liver injury and carcinogenesis.

Ductular reactions (DRs) are observed in virtually all forms of human liver disease; however, the histogenesis and function of DRs in liver injury are not entirely understood. It is widely believed that DRs contain bipotential liver progenitor cells (LPCs) that serve as an emergency cell pool to regenerate both cholangiocytes and hepatocytes and may eventually give rise to hepatocellular carcinoma (HCC). Here, we used a murine model that allows highly efficient and specific lineage labeling of the biliary compartment to analyze the histogenesis of DRs and their potential contribution to liver regeneration and carcinogenesis. In multiple experimental and genetic liver injury models, biliary cells were the predominant precursors of DRs but lacked substantial capacity to produce new hepatocytes, even when liver injuries were prolonged up to 12 months. Genetic modulation of NOTCH and/or WNT/β-catenin signaling within lineage-tagged DRs impaired DR expansion but failed to redirect DRs from biliary differentiation toward the hepatocyte lineage. Further, lineage-labeled DRs did not produce tumors in genetic and chemical HCC mouse models. In summary, we found no evidence in our system to support mouse biliary-derived DRs as an LPC pool to replenish hepatocytes in a quantitatively relevant way in injury or evidence that DRs give rise to HCCs

CCL2/MCP-I Genotype-Phenotype Relationship in Latent Tuberculosis Infection

Among the known biomarkers, chemokines, secreted by activated macrophages and T cells, attract groups of immune cells to the site of infection and may determine the clinical outcome. Association studies of CCL-2/MCP-1 -2518 A/G functional SNP linked to high and low phenotypes with tuberculosis disease susceptibility have shown conflicting results in tuberculosis. Some of these differences could be due the variability of latent infection and recent exposure in the control groups. We have therefore carried out a detailed analysis of CCL-2 genotype SNP -2518 (A/G transition) with plasma CCL-2 levels and related these levels to tuberculin skin test positivity in asymptomatic community controls with no known exposure to tuberculosis and in recently exposed household contacts of pulmonary tuberculosis patients. TST positivity was linked to higher concentrations of plasma CCL2 (Mann Whitney U test; p = 0.004) and was more marked when the G allele was present in TST+ asymptomatic controls (A/G; p = 0.01). Recent exposure also had a significant effect on CCL-2 levels and was linked to the G allele (p = 0.007). Therefore association studies for susceptibility or protection from disease should take into consideration the PPD status as well as recent exposure of the controls group used for comparison. Our results also suggest a role for CCL-2 in maintaining the integrity of granuloma in asymptomatic individuals with latent infection in high TB burden settings. Therefore additional studies into the role of CCL-2 in disease reactivation and progression are warranted

Protein Kinase C Iota Regulates Pancreatic Acinar-to-Ductal Metaplasia

Pancreatic acinar-to-ductal metaplasia (ADM) is associated with an increased risk of pancreatic cancer and is considered a precursor of pancreatic ductal adenocarcinoma. Transgenic expression of transforming growth factor alpha (TGF-α) or K-rasG12D in mouse pancreatic epithelium induces ADM in vivo. Protein kinase C iota (PKCι) is highly expressed in human pancreatic cancer and is required for the transformed growth and tumorigenesis of pancreatic cancer cells. In this study, PKCι expression was assessed in a mouse model of K-rasG12D-induced pancreatic ADM and pancreatic cancer. The ability of K-rasG12D to induce pancreatic ADM in explant culture, and the requirement for PKCι, was investigated. PKCι is elevated in human and mouse pancreatic ADM and intraepithelial neoplastic lesions in vivo. We demonstrate that K-rasG12D is sufficient to induce pancreatic ADM in explant culture, exhibiting many of the same morphologic and biochemical alterations observed in TGF-α-induced ADM, including a dependence on Notch activation. PKCι is highly expressed in both TGF-α- and K-rasG12D-induced pancreatic ADM and inhibition of PKCι significantly reduces TGF-α- and K-rasG12D-mediated ADM. Inhibition of PKCι suppresses K-rasG12D–induced MMP-7 expression and Notch activation, and exogenous MMP-7 restores K-rasG12D–mediated ADM in PKCι-depleted cells, implicating a K-rasG12D-PKCι-MMP-7 signaling axis that likely induces ADM through Notch activation. Our results indicate that PKCι is an early marker of pancreatic neoplasia and suggest that PKCι is a potential downstream target of K-rasG12D in pancreatic ductal metaplasia in vivo

Inactivation of TIF1γ Cooperates with KrasG12D to Induce Cystic Tumors of the Pancreas

Inactivation of the Transforming Growth Factor Beta (TGFβ) tumor suppressor pathway contributes to the progression of Pancreatic Ductal AdenoCarcinoma (PDAC) since it is inactivated in virtually all cases of this malignancy. Genetic lesions inactivating this pathway contribute to pancreatic tumor progression in mouse models. Transcriptional Intermediary Factor 1 gamma (TIF1γ) has recently been proposed to be involved in TGFβ signaling, functioning as either a positive or negative regulator of the pathway. Here, we addressed the role of TIF1γ in pancreatic carcinogenesis. Using conditional Tif1γ knockout mice (Tif1γlox/lox), we selectively abrogated Tif1γ expression in the pancreas of Pdx1-Cre;Tif1γlox/lox mice. We also generated Pdx1-Cre;LSL-KrasG12D;Tif1γlox/lox mice to address the effect of Tif1γ loss-of-function in precancerous lesions induced by oncogenic KrasG12D. Finally, we analyzed TIF1γ expression in human pancreatic tumors. In our mouse model, we showed that Tif1γ was dispensable for normal pancreatic development but cooperated with Kras activation to induce pancreatic tumors reminiscent of human Intraductal Papillary Mucinous Neoplasms (IPMNs). Interestingly, these cystic lesions resemble those observed in Pdx1-Cre;LSL-KrasG12D;Smad4lox/lox mice described by others. However, distinctive characteristics, such as the systematic presence of endocrine pseudo-islets within the papillary projections, suggest that SMAD4 and TIF1γ don't have strictly redundant functions. Finally, we report that TIF1γ expression is markedly down-regulated in human pancreatic tumors by quantitative RT–PCR and immunohistochemistry supporting the relevance of these findings to human malignancy. This study suggests that TIF1γ is critical for tumor suppression in the pancreas, brings new insight into the genetics of pancreatic cancer, and constitutes a promising model to decipher the respective roles of SMAD4 and TIF1γ in the multifaceted functions of TGFβ in carcinogenesis and development

The role of host genetic factors in respiratory tract infectious diseases:systematic review, meta-analyses and field synopsis

Host genetic factors have frequently been implicated in respiratory infectious diseases, often with inconsistent results in replication studies. We identified 386 studies from the total of 24,823 studies identified in a systematic search of four bibliographic databases. We performed meta-analyses of studies on tuberculosis, influenza, respiratory syncytial virus, SARS-Coronavirus and pneumonia. One single-nucleotide polymorphism from IL4 gene was significant for pooled respiratory infections (rs2070874; 1.66 [1.29-2.14]). We also detected an association of TLR2 gene with tuberculosis (rs5743708; 3.19 [2.03-5.02]). Subset analyses identified CCL2 as an additional risk factor for tuberculosis (rs1024611; OR = 0.79 [0.72-0.88]). The IL4-TLR2-CCL2 axis could be a highly interesting target for translation towards clinical use. However, this conclusion is based on low credibility of evidence - almost 95% of all identified studies had strong risk of bias or confounding. Future studies must build upon larger-scale collaborations, but also strictly adhere to the highest evidence-based principles in study design, in order to reduce research waste and provide clinically translatable evidenc

Expanded analyses of NAPOLI-1: Phase 3 study of nal-IRI (MM-398), with or without 5-fluorouracil (5FU) and leucovorin (LV), versus 5-fluorouracil and leucovorin (5FU/LV), in metastatic pancreatic cancer (mPAC) previously treated with gemcitabine-based therapy

[[abstract]]Question: Nal-IRI is a nanoliposomal encapsulated formulation of irinotecan. OS in the ITT population was significantly longer with nal-IRI+5FU/LV (n = 117) vs 5FU/LV (n = 119) (median OS was 6.1 m vs 4.2 m; unstratified HR = 0.67, log-rank test p = 0.012). Most frequent grade 3+ AEs included neutropenia, fatigue and GI-effects. Thes e expanded, pre-specified analyses have been presented. Methods: Patients with mPAC (n = 417) previously treated with gemcitabine-based therapy, were randomized 1:1:1 to receive: Nal-IRI (120 mg/m 2 ; IV 90 min) q3w; 5FU (2,000 mg/m 2 ; 24 h) + LV (200 mg/m 2 ; 30 min) ×4w followed by 2w rest; or combination of nal-IRI (80 mg/m 2 ; IV 90 min) prior to 5FU (2,400 mg/m 2 ; 46h) + LV (400 mg/m 2 ; 30min) q2w. Primary endpoint was OS. The ITT population included all randomized patients; the Per Protocol (PP) population included patients who received ≥80% of the target dose in the first 6 weeks and did not violate any in/ exclusion criteria. Results: Analysis of the PP populations confirmed the favorable OS of the combination nal-IRI+5FU/LV, which was also reflected by the PFS, ORR and CA19-9 levels. Median OS in the PP population for nal-IRI+5FU/ LV-arm was 8.9 m (n = 66) vs 5.1 m (n = 71) for 5FU/LV (unstratified HR = 0.57, log-rank test p = 0.011). The nal-IRI monotherapy arm did not show a statistically significant OS improvement over 5FU/LV. Analysis of subgroups, based on pretreatment characteristics including stage at diagnosis, time since initial histological diagnosis, prior lines of therapy, time since last prior therapy, and CA19-9, favored OS for the nal-IRI+5FU/ LV arm. Conclusions: Expanded analysis of the PP population and sensitivity analyses support the favorability of nal-IRI+5FU/LV over 5FU/LV, with amanageable safety profile

Subgroup analysis by measurable metastatic lesion (ML) number and selected lesion locations (LL) at baseline (BL) in NAPOLI-1: A phase III study of liposomal irinotecan (nal-IRI)+/- 5-fluorouracil/leucovorin (5-FU/LV) in patients (pts) with metastatic pan

[[abstract]]Background: We report a post hoc, exploratory analysis of pts with BL ML number and LL data who received nal-IRI+5-FU/LV, nal-IRI or 5-FU/LV in NAPOLI-1, a pivotal, phase 3 trial (NCT01494506). nal-IRI+5-FU/LV increased median OS (mOS) vs 5-FU/LV (6.1 vs 4.2 mo [HR=0.67; p=0.012]). Methods: ML (1, 2, 3, >3) and LL were recorded (local investigator) at BL. Pts with >1 LL were counted for each location. Results: 354 of 417 ITT pts had measurable BL ML and 1,080 LL were recorded. There was no clear trend in the percentage of pts with KPS ≥80 in 1- >3 ML (range 87%-95%) or LL (range 89%-94%) subgroups. ML 1 (n=81), 2 (n=65) and 3 (n=24) subgroups were small. nal-IRI+5-FU/LV significantly improved mOS vs. 5-FU/LV in pts with 2/>3 ML (n=184/24); nal-IRI+5-FU/LV had numerically higher mOS vs. 5-FU/LV for all LL (Table). nal-IRI+5-FU/LV had favourable median PFS (mPFS) vs. 5-FU/LV in pts with 1–>3 ML (range 2.0-4.2 vs. 1.4-1.9 mo; HR range 0.35-0.88) and for all LL (range 2.8-4.2 vs. 1.4-2.0 mo; HR range 0.39-0.55). Conclusions: Low pt numbers across groups and repeat counting of pts in LL subgroups preclude firm conclusions on treatment efficacy, pending further analyses. Allowing for these limitations, we detected no clear prognostic effect on outcomes of higher BL ML number or LL in NAPOLI-1 ITT pts. nal-IRI+5-FU/LV improved mOS vs. 5-FU/LV in some ML groups and across LL groups; improvement in mPFS vs. 5-FU/LV in the ITT population was maintained in all subgroups