Background
Hepatosteatosis is the earliest stage in the pathogenesis of nonalcoholic fatty (NAFLD) and alcoholic liver disease (ALD). As NAFLD is affecting 10–24% of the general population and ...approximately 70% of obese patients, it carries a large economic burden and is becoming a major reason for liver transplantation worldwide. ALD is a major cause of morbidity and mortality causing 50% of liver cirrhosis and 10% of liver cancer related death. Increasing evidence has accumulated that gut-derived factors play a crucial role in the development and progression of chronic liver diseases.
Methods
A selective literature search was conducted in Medline and PubMed, using the terms “nonalcoholic fatty liver disease,” “alcoholic liver disease,” “lipopolysaccharide,” “gut barrier,” and “microbiome.”
Results
Gut dysbiosis and gut barrier dysfunction both contribute to chronic liver disease by abnormal regulation of the gut-liver axis. Thereby, gut-derived lipopolysaccharides (LPS) are a key factor in inducing the inflammatory response of liver tissue. The review further underlines that endotoxemia is observed in both NAFLD and ALD patients. LPS plays an important role in conducting liver damage through the LPS-TLR4 signaling pathway. Treatments targeting the gut microbiome and the gut barrier such as fecal microbiota transplantation (FMT), probiotics, prebiotics, synbiotics, and intestinal alkaline phosphatase (IAP) represent potential treatment modalities for NAFLD and ALD.
Conclusions
The gut-liver axis plays an important role in the development of liver disease. Treatments targeting the gut microbiome and the gut barrier have shown beneficial effects in attenuating liver inflammation and need to be further investigated.
Hepatic ischemia-reperfusion injury (IRI) represents a major challenge during liver surgery, liver preservation for transplantation, and can cause hemorrhagic shock with severe hypoxemia and trauma. ...The reduction of blood supply with a concomitant deficit in oxygen delivery initiates various molecular mechanisms involving the innate and adaptive immune response, alterations in gene transcription, induction of cell death programs, and changes in metabolic state and vascular function. Hepatic IRI is a major cause of morbidity and mortality, and is associated with an increased risk for tumor growth and recurrence after oncologic surgery for primary and secondary hepatobiliary malignancies. Therapeutic strategies to prevent or treat hepatic IRI have been investigated in animal models but, for the most part, have failed to provide a protective effect in a clinical setting. This review focuses on the molecular mechanisms underlying hepatic IRI and regeneration, as well as its clinical implications. A better understanding of this complex and highly dynamic process may allow for the development of innovative therapeutic approaches and optimize patient outcomes.
Background
The formation of neutrophil extracellular traps (NETs) was initially discovered as a novel immune response against pathogens. Recent studies have also suggested that NETs play an important ...role in tumor progression. This review summarizes the cellular mechanisms by which NETs promote distant metastasis and discusses the possible clinical applications targeting NETs.
Method
The relevant literature from PubMed and Google Scholar (2001–2021) have been reviewed for this article.
Results
The presence of NETs has been detected in various primary tumors and metastatic sites. NET-associated interactions have been observed throughout the different stages of metastasis, including initial tumor cell detachment, intravasation and extravasation, the survival of circulating tumor cells, the settlement and the growth of metastatic tumor cells. Several in vitro and in vivo studies proved that inhibiting NET formation resulted in anti-cancer effects. The biosafety and efficacy of some NET inhibitors have also been demonstrated in early phase clinical trials.
Conclusions
Considering the role of NETs in tumor progression, NETs could be a promising diagnostic and therapeutic target for cancer management. However, current evidence is mostly derived from experimental models and as such more clinical studies are still needed to verify the clinical significance of NETs in oncological settings.
Farnesoid X receptor (FXR, NR1H4) is a ligand-activated nuclear receptor, which regulates bile acid, lipid and glucose metabolism. Due to these functions, FXR has been investigated as a potential ...drug target for the treatment of liver diseases, such as primary biliary cholangitis and non-alcoholic steatohepatitis. Based on the previously described four splice variants, it has been suggested that alternative promoter usage and splicing may have an impact on total FXR activity as a result of encoding functionally diverse variants. Here we aimed for a systematic analysis of human hepatic FXR splice variants. In addition to the previously described FXRα1–4, we identified four novel splice variants (FXRα5–8) in human hepatocytes, which resulted from previously undetected exon skipping events. These newly identified isoforms displayed diminished DNA binding and impaired transactivation activities. Isoform FXRα5, which suppressed the transactivation activity of the functional isoform FXRα2, was further characterized as deficient in heterodimerization, coactivator recruitment and ligand binding. These findings were further supported by molecular dynamics simulations, which offered an explanation for the behavior of this isoform on the molecular level. FXRα5 exhibited low uniform expression levels in nearly all human tissues. Our systematic analysis of FXR splice variants in human hepatocytes resulted in the identification of four novel FXR isoforms, which all proved to be functionally deficient, but one novel variant, FXRα5, also displayed dominant negative activity. The possible associations with and roles of these novel isoforms in human liver diseases require further investigation.
•Four novel splice variants of farnesoid X receptor, FXRα5-8, were identified.•Novel isoforms display impaired transactivation and DNA-binding properties.•FXRα5 with disrupted ligand-binding domain exhibits dominant negative activity.•Molecular dynamics simulations explain FXRα5 loss-of function on the molecular level.•Dominant negative isoform FXRα5 shows low expression levels in healthy tissues.
Background The need for adjuvant chemotherapy after resection of ampullary cancer (PapCa) remains undefined. Recent data suggest that a different epithelial origin of PapCa might be associated with ...different tumor biology. The aim of the present study was to assess the clinical value of morphologic and immunohistochemic subclassification of PapCa into intestinal-type (IT) and pancreaticobiliary-type (PT) to predict chemotherapy response and overall survival (OS). Methods Via a prospective database, 112 PapCa were identified, of which 95 could be included in the present study. Those were compared with 206 matching patients with periampullary pancreatic cancer (ie, pancreatic ductal adenocarcinoma, PDAC). IT and PT PapCa were classified morphologically, and tissue microarray was prepared with immunohistochemistry for CK7, CK20, MUC2, CDX2, ß-Catenin, and Villin. Multivariate survival analysis was performed. Results OS of PT patients was less compared with IT patients (25 vs 98 months; P < .001), whereas it was comparable with patients with PDAC (25 vs 14 months; P = .123). PT patients receiving adjuvant gemcitabine chemotherapy featured improved OS (32 vs 13 months; P = .013), whereas gemcitabine tended to be associated with decreased OS in IT patients (35 vs 112 months; P = .193). Besides histopathologic classification, expression of CK7 and MUC2 were important prognostic variables. PT patients with CK7-positivity or MUC2-negativity were segregated into an even poorer prognostic group. Conclusion PapCa is not a separate tumor entity. We demonstrate important differences between IT-PapCa and PT-PapCa not only in long-term survival but also in response to adjuvant gemcitabine. Tumor biology and clinical course of PT tumors resemble those of PDAC. PT tumors should therefore be treated like PDAC.
Our preliminary studies identified a small population side population (SP) cells in pancreatic cancer cells with stem cell-like properties, which were able to induce fast and aggressive tumor ...formation in nude mice. Gene expression analysis showed a significant difference in the expression of more than 1,300 genes in SP cells, among which a highly significant difference in microRNA expression of miR-21 and miR-221 between SP and NSP cells was identified. SP cells were identified and characterized by flow cytometry using Hoechst 33342 dye staining from a highly metastatic human pancreatic cancer cell line (L3.6pl). Antagomir transfection was performed using miRNA-21 and miRNA-221 antisense oligonucleotides (ASOs) and followed by detection of cell apoptosis, cell cycle progression, chemosensitivity, and invasion. Sorted SP cells from gemcitabine-resistant L3.6pl cells (L3.6pl
Gres
-SP) cells were orthotopically implanted in nude mice with or without miRNA-21 and miRNA-221 ASOs mono- and combination therapy. The administration of antagomir-21 and antagomir-221 significantly reduced the SP cell fraction, decreased SP cell differentiation, and downstream gene regulation, and thereby induced reduction of L3.6pl cell proliferation, invasion, and chemoresistance against gemcitabine and 5-Fluorouracil. Combination of ASOs therapy against miRNA-21 and miRNA-221 significantly inhibited primary tumor growth and metastasis compared to single antagomir treatment, especially, in L3.6pl
Gres
-SP-induced pancreatic tumor growth in vivo. These findings further indicate that the inhibition of miR-21 and miR-221 appear particularly suitable to target stem-like subpopulations and address their specific biological function to promote tumor progression in pancreatic cancer.
The effect of bacterobilia on morbidity after pancreatoduodenectomy remains unclear. The aim of this study was to examine the influence of positive intraoperative bile cultures and perioperative ...antibiotic prophylaxis on morbidity measured using the Comprehensive Complication Index, a weighted composite of postoperative complications.
Intraoperative bile cultures of 182 patients who underwent pancreatoduodenectomy were obtained. We examined the effect of intraoperative bile cultures and perioperative antibiotic prophylaxis on the Comprehensive Complication Index and the occurrence of postoperative complications. To this aim, we performed general linear models controlling for relevant demographic and perioperative factors.
Positive (versus negative) intraoperative bile cultures were associated with a higher mean Comprehensive Complication Index (25.34 vs 16.81, P = .025). The mean Comprehensive Complication Index differed significantly between individuals with positive intraoperative bile cultures and bacterial strains not covered by perioperative antibiotic prophylaxis (26.2) versus positive intraoperative bile cultures and bacterial strains sensitive to perioperative antibiotic prophylaxis (22.7) (P = .045). Positive (versus negative) intraoperative bile cultures were associated with 4.75 times (95% confidence interval: 1.74–13.00, P = .002) greater odds of wound infections. The odds of wound infection were 1.93 times (95% confidence interval: .47–8.04) greater in those with positive intraoperative bile cultures and adequate perioperative antibiotic prophylaxis and 6.14 times (95% confidence interval: 2.17–17.35) greater in those with positive intraoperative bile cultures and inadequate perioperative antibiotic prophylaxis (versus negative intraoperative bile cultures) (P = .001).
Bacterobilia is associated with a significant increase in Comprehensive Complication Index and wound infections after pancreatoduodenectomy, which may be reduced by administration of a specific perioperative antibiotic prophylaxis. Acquisition of bile cultures sampled through the external conduit of patients with preoperative biliary drainage could help in selecting a specific perioperative antibiotic prophylaxis and patients with bile duct stents might benefit from broad spectrum perioperative antibiotic prophylaxis.
Sonography is often the first imaging procedure to be used in diagnostic investigation of the abdomen. The aim of this article is to provide a new interdisciplinary overview of recent groundbreaking ...advances in this modality.
A selective survey of the literature in PubMed was conducted. The literature search was carried out in 2021-2022 and included publications over the period 2004-2022.
The novel sonographic software techniques can be divided into algorithms that deal with conventional B-scan optimization and new programs that extend the scope of sonographic examination. The latter include elastography, contrast-enhanced sonography, and image fusion in combination with other cross-sectional imaging modalities. Elastography can be used to assess the presence of steatosis, fibrosis, or cirrhosis in patients with liver disease. One study reported diagnostic accuracy of 84-87% for the diagnosis of significant fibrosis (F2), 89-91% for the diagnosis of severe fibrosis (F3), and 92-93% for the diagnosis of liver cirrhosis (F4). Contrast-enhanced sonography is used for evaluation of tumors and trauma. A prospective multicenter study found sensitivity of 95.8% for the characterization of malignant lesions and specificity of 83.1% for benign lesions. Image fusion has the potential to improve the diagnostic assessment of parenchymatous organs, vascular conditions, and the prostate.
With continuous improvement of the B-scan and the development of high-frequency probes and novel investigation techniques, sonography has become established as an increasingly autonomous examination procedure.
Epithelial-mesenchymal transition (EMT), angiogenesis, cell adhesion and extracellular matrix (ECM) interaction are essential for colorectal cancer (CRC) metastasis. Low grade mucinous neoplasia of ...the appendix (LAMN) and its advanced state low grade pseudomyxoma peritonei (lgPMP) show local aggressiveness with very limited metastatic potential as opposed to CRC. To better understand the underlying processes that foster or impede metastatic spread, we compared LAMN, lgPMP, and CRC with respect to their molecular profile with subsequent pathway analysis.
LAMN, lgPMP and (mucinous) CRC cases were subjected to transcriptomic analysis utilizing Poly(A) RNA sequencing. Successfully sequenced cases (LAMN n = 10, 77%, lgPMP n = 13, 100% and CRC n = 8, 100%) were investigated using bioinformatic and statistical tests (differential expression analysis, hierarchical clustering, principal component analysis and gene set enrichment analysis).
We identified a gene signature of 28 genes distinguishing LAMN, lgPMP and CRC neoplasias. Ontology analyses revealed that multiple pathways including EMT, ECM interaction and angiogenesis are differentially regulated. Fifty-three significantly differentially regulated gene sets were identified between lgPMP and CRC followed by CRC vs. LAMN (n = 21) and lgPMP vs. LAMN (n = 16). Unexpectedly, a substantial enrichment of the EMT gene set was observed in lgPMP vs. LAMN (FDR=0.011) and CRC (FDR=0.004). Typical EMT markers were significantly upregulated (Vimentin, TWIST1, N-Cadherin) or downregulated (E-Cadherin) in lgPMP. However, MMP1 and MMP3 levels, associated with EMT, ECM and metastasis, were considerably higher in CRC.
We show that the different tumor biological behaviour and metastatic spread pattern of midgut malignancies is reflected in a different gene expression profile. We revealed a strong activation of the EMT program in non-metastasizing lgPMP vs. CRC. Hence, although EMT is considered a key step in hematogenous spread, successful EMT does not necessarily lead to hematogenous dissemination. This emphasizes the need for further pathway analyses and forms the basis for mechanistic and therapy-targeting research.
The use of engineered mesenchymal stem cells (MSCs) as therapeutic vehicles for the treatment of experimental pancreatic and breast cancer has been previously demonstrated. The potential application ...of MSCs for the treatment of hepatocellular carcinoma (HCC) has been controversial. The general approach uses engineered MSCs to target different aspects of tumor biology, including angiogenesis or the fibroblast-like stromal compartment, through the use of tissue-specific expression of therapeutic transgenes. The aim of the present study was (1) to evaluate the effect of exogenously added MSCs on the growth of HCC and (2) the establishment of an MSC-based suicide gene therapy for experimental HCC.
Mesenchymal stem cells were isolated from bone marrow of C57/Bl6 p53(-/-) mice. The cells were injected into mice with HCC xenografts and the effect on tumor proliferation and angiogenesis was evaluated. The cells were then stably transfected with red fluorescent protein (RFP) or Herpes simplex virus thymidine kinase (HSV-Tk) gene under control of the Tie2 promoter/enhancer or the CCL5 promoter. Mesenchymal stem cells were injected intravenously into mice with orthotopically growing xenografts of HCC and treated with ganciclovir (GCV).
Ex vivo examination of hepatic tumors revealed tumor-specific recruitment, enhanced tumor growth, and increased microvessel density after nontherapeutic MSC injections. After their homing to the hepatic xenografts, engineered MSCs demonstrated activation of the Tie2 or CCL5 promoter as shown by RFP expression. Application of CCL5/HSV-TK transfected MSCs in combination with GCV significantly reduced tumor growth by 56.4% as compared with the control group and by 71.6% as compared with nontherapeutic MSC injections. CCL5/HSV-TK(+) transfected MSCs proved more potent in tumor inhibition as compared with Tie2/HSV-TK(+) MSCs.
Exogenously added MSCs are recruited to growing HCC xenografts with concomitant activation of the CCL5 or Tie2 promoters within the MSCs. Stem cell-mediated introduction of suicide genes into the tumor followed by prodrug administration was effective for treatment of experimental HCC and thus may help fill the existing gap in bridging therapies for patients suffering from advanced HCCs.
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