Receptor-interacting protein 1(RIPK1) has an essential role in the signaling pathways triggered by death receptors through activation of NF-κB and regulation of caspase-dependent apoptosis and RIPK3/mixed lineage kinase domain-like protein(MLKL)-mediated necroptosis. We examined the effect of RIPK1 antisense knockdown on the immune-mediated liver injury in C57BL/6 mice caused by α-galactosylceramide (αGalCer), a specific activator for invariant NKT cells. We found that knockdown of RIPK1 markedly exacerbated αGalCer-mediated liver injury and induced lethality. This was associated with increased hepatic inflammation and massive apoptotic death of hepatocytes as indicated by TUNEL staining and caspase-3 activation. Pretreatment with either zVAD.fmk, a pan-caspase inhibitor, or neutralizing Abs against TNF, almost completely protected against the exacerbated liver injury and lethality. Primary hepatocytes isolated from RIPK1 knockdown mice were sensitized to TNF-induced cell death that was completely inhibited by adding zVAD.fmk. Unexpectedly, the exacerbated liver injury was not due to impaired hepatic NF-κB activation in terms of IκBα phosphorylation and degradation in both in vivo and in vitro studies. Lack of RIPK1 kinase activity by either pretreatment with necrostatin-1, a RIPK1 kinase inhibitor, or in the RIPK1 kinase-dead knock-in (RIPK1D138N) mice, did not exacerbate αGalCer-mediated liver injury. Furthermore, both RIPK3 and MLKL knockout mice behaved similarly as wild type control mice in response to αGalCer with or without knockdown of RIPK1, excluding a switch to RIPK3/MLKL-mediated necroptosis. Our findings for the first time revealed a critical kinase-independent platform role of RIPK1 in protecting against TNF/caspase-dependent apoptosis of hepatocytes in immune-mediated liver injury.
We aimed to reveal clinicopathological features and explore survival-related factors of colorectal signet ring cell carcinoma (SRCC). A population-based study was carried out to investigate colorectal SRCC by using data extracted from the surveillance, epidemiology and end results (SEER) database between 2004 and 2015. In total, 3,278 patients with colorectal SRCC were identified, with a median age of 63 (12–103) years old. The lesions of most patients (60.49%) were located in the cecum–transverse colon. In addition, 81.27% patients had advanced clinical stage (stage III/IV), and 76.69% patients had high pathological grade. The 3–, 5–year cancer‐specific survival and overall survival rate was 35.76%, 29.32% and 32.32%, 25.14%. Multivariate analysis revealed that primary site in cecum–transverse colon, married, received surgery, lymph node dissections ≥ 4 regional lymph nodes were independent favorable prognostic. Meanwhile, aged ≥ 65 years, higher grade, tumor size ˃5 cm and advanced AJCC stage were associated with poor prognosis. Patient age, tumor grade, marital status, tumor size, primary tumor location, AJCC stage, surgery and number of dissected lymph node had significant correlation with prognosis of colorectal SRCC.
Numerous genetic alterations associated with cancer progression have the potential to serve as biomarkers for the early diagnosis of cancer. Numerous studies have suggested that claudin proteins, which are the primary components of tight junction structures, are associated with the regulation of cell polarity and cell differentiation. To investigate the expression profiles of the tight junction proteins claudin-2, −5, −7 and −8 in gastric carcinoma, immunohistochemical analysis, western blotting and reverse transcription-quantitative polymerase chain reaction analysis was used to detect the expression profiles of these claudin proteins in gastric carcinoma tissues and in homologous non-neoplastic mucosal tissues. According to the present study, the expression levels of claudin-7 and claudin-8 were downregulated, while the expression of claudin-5 was upregulated in gastric carcinoma tissues compared with in non-neoplastic mucosal tissues. Additionally, no notable difference was observed between claudin-2 expression in gastric carcinoma tissues and non-neoplastic mucosae. Correlations between claudin-7 and −8 expression and lymphatic metastasis in gastric carcinoma tissues were additionally reported. In summary, the present study revealed the distinct expression profiles of claudin-5, −7 and −8 in non-neoplastic mucosal tissues and gastric carcinoma tissues. Furthermore, the expression of these claudin proteins was highly associated with metastatic progression and prognosis in patients with gastric carcinoma, and had predictive value for the metastasis and survival of patients with gastric carcinoma.
These findings suggest that silencing β-catenin gene may induce the changes of cell cycle and cyclin B1 and cyclin C protein expression. Wnt/β-catenin signaling pathway probably takes part in the genesis and development of HCC through regulating cell cycle and the expression of cyclin B1 and cyclin C.
The retinoid-interferon-induced mortality-19 (GRIM-19) gene has been identified as a negative regulator associated with tumor development. The current study created a model of an orthotopically implanted hepatocarcinoma tumor to verify the inhibitory effect of GRIM-19 in vivo. After treatment with GRIM-19 carried by attenuated Salmonella, transplanted tumors were measured with an Imaging System. The expression of GRIM-19, Stat3/ p-Stat3, cyclinD1, CDK4, PCNA, Bax/Bcl-2, cleaved caspase-9/3, VEGF, and MMP-2/9 was determined using immunohistochemistry and Western blot analysis. The cell cycle was assessed using flow cytometry (FCM). Apoptosis was determined using FCM and a TUNEL assay. Results indicated that GRIM-19 overexpression resulted in inhibition of peritoneal metastasis, induction of cell cycle arrest, and apoptosis in vivo. In addition, the expression of Stat3/p-Stat3 was down-regulated by GRIM-19. These results suggest that GRIM-19 overexpression could suppress the growth of orthotopically implanted hepatocarcinoma tumors by reversing the regulation of the Stat3 signaling pathway. This approach could potentially be a powerful treatment for hepatocarcinoma.
In this study, a sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of demethylzeylasteral in rat plasma. Electrospray ionization was operated in the negative ion mode while demethylzeylasteral and oleanolic acid (internal standard) were measured by selected reaction monitoring (demethylzeylasteral: m/z 479.2 → 436.0; oleanolic acid: m/z 454.9 → 407.2). This LC-MS/MS method had good selectivity, sensitivity, accuracy and precision. The pharmacokinetic profiles of demethylzeylasteral were subsequently examined in Wistar rats after oral or intravenous administration.
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