DKK1 Promotes Epithelial-Mesenchymal Transition and Cisplatin Resistance in Gastric Cancer via Activation of the PI3K/AKT Pathway.

Chemotherapy is a classical method of cancer treatment. Cisplatin-based chemotherapy is a traditional and essential therapeutic approach in gastric cancer treatment. However, the development of drug resistance during treatment is a major obstacle that limits their further application, and molecular changes have occurred in the development of drug resistance. Here, we found that Dickkopf-related protein 1 (DKK1) is highly expressed in gastric cancer and related to poor prognosis in gastric cancer patients through public database mining. Next, we also identified that DKK1 is highly expressed in CDDP-resistant gastric cancer cell lines, supporting the notion that DKK1 is a necessary regulator of CDDP resistance. In terms of mechanistic research, our data reveal that DKK1 was able to activate the PI3K/AKT pathway and affect epithelial-to-mesenchymal transition, further contributing to CDDP resistance. Genetic knockdown and pharmacological inhibition of DKK1 recovered CDDP sensitivity both in vitro and in vivo. Therefore, our study highlights the potential of targeted inhibition of DKK1 to reverse CDDP resistance and alleviate metastatic properties in gastric cancer.

LMX1A inhibits C-Myc expression through ANGPTL4 to exert tumor suppressive role in gastric cancer.

Our research group has showed that the LIM homeobox transcription factor 1 alpha (LMX1A) is inactivated in gastric cancers. Overexpression of LMX1A inhibits tumor growth. However, the mechanisms remains unclear. Considering LMX1A as a transcription factor, a comparison of RNA-seq between gastric cancer cells (GCCs) and GCCs with LMX1A overexpressed was performed to identify genes transcriptionally activated by LMX1A. Among the potential LMX1A target genes, angiopoietin-like 4 (ANGPTL4) has been reported to be an important tumor suppressor and thus was selected for further validation and research. Both LMX1A and ANGPTL4 showed downregulated expression in gastric cancer samples. More importantly, the expression of LMX1A is positively correlated with ANGPTL4, without including other family members in gastric cancer cell lines. What's more, knockdown of ANGPTL4 rescued the tumor suppressive phenotype of LMX1A overexpression, which indicated that LMX1A upregulates ANGPTL4 to exert its role. Mechanistically, we found that LMX1A inhibited the expression of the oncogene C-Myc, which is alleviated by ANGPTL4 knockdown. In general, our results showed that LMX1A exerts its tumor suppressive role by activating ANGPTL4 to inhibit C-Myc.

Synthesis of phosphatidylcholine in rats with oleic acid-induced pulmonary edema and effect of exogenous pulmonary surfactant on its De Novo synthesis.

In mammals, oleic acid (OA) induces pulmonary edema (PE), which can initiate acute lung injury (ALI) and lead to acute respiratory distress syndrome (ARDS). Pulmonary surfactant (PS) plays a key role in a broad range of treatments for ARDS. The aim of the present investigation was to assess changes in the synthesis of phosphatidylcholine (PC) from choline and determine the effect of exogenous PS on its de novo synthesis in rats with OA-induced PE. Experimental rats were randomized into three groups, including a control group, OA-induced PE group, and OA-induced group treated with exogenous PS (OA-PS). Twenty-four rats were sacrificed 4 h after induction of the OA model, and tissue was examined by light and electron microscopy to assess the severity of ALI using an established scoring system at the end of the experiment. After 15 µCi 3H-choline chloride was injected intravenously, eight rats in each group were sacrificed at 4, 8, and 16 h. The radioactivity of 3H incorporated into total phospholipid (TPL) and desaturated phosphatidylcholine (DSPC) was measured in bronchoalveolar lavage fluid (BALF) and lung tissue (LT) using a liquid scintillation counter and was expressed as counts per minute (CPM). Results showed that TPL, DSPC, and the ratio of DSPC/total protein (TP) in lung tissue decreased 4 h after challenge with OA, but the levels recovered after 8 and 16 h. At 8 h after injection, 3H-TPL and 3H-DSPC radioactivity in the lungs reached its peak. Importantly, 3H-DSPC CPM were significantly lower in the PS treatment group (LT: Control: 62327 ± 9108; OA-PE: 97315 ± 10083; OA-PS: 45127 ± 10034, P < 0.05; BALF: Control: 7771 ± 1768; OA-PE: 8097 ± 1799; OA-PE: 3651 ± 1027, P < 0.05). Furthermore, DSPC secretory rate (SR) in the lungs was significantly lower in the PS treatment group at 4 h after injection (Control: 0.014 ± 0.003; OA-PE: 0.011 ± 0.004; OA-PS: 0.023 ± 0.006, P < 0.05). Therefore, we hypothesize that exogenous PS treatments may adversely affect endogenous de novo synthetic and secretory phospholipid pathways via feedback inhibition. This novel finding reveals the specific involvement of exogenous PS in endogenous synthetic and secretory phospholipid pathways during the treatment of ARDS. This information improves our understanding of how PS treatment is beneficial against ARDS and opens new opportunities for expanding its use.

Relationship between serum HBV-RNA levels and intrahepatic viral as well as histologic activity markers in entecavir-treated patients.

BACKGROUND & AIMS: In diagnostics, serum hepatitis B virus (HBV)-RNA levels are valuable when the HBV-DNA load in circulation is effectively suppressed by nucleos(t)ide analogue (NUC) therapy. This study aimed to determine the intrahepatic viral replication activity reflected in serum HBV-RNA and whether HBV-RNA contributes to liver histological changes in patients treated with NUC. METHODS: A cross-sectional set of serum and liver biopsy samples was obtained from patients treated with entecavir, who had undetectable levels of serum HBV-DNA. The correlations between serum HBV-RNA concentration and levels of peripheral and intrahepatic viral replicative forms, as well as histological scores, were analyzed. Quasispecies of serum HBV-RNA and intrahepatic viral replicative forms were examined by deep sequencing. HBV-RNA-positive hepatocytes were visualized by in situ hybridization. RESULTS: Serum HBV-RNA was detected in 35 of 47 patients (74.47%, 2.33-4.80log10copies/ml). These levels correlated not only with the intrahepatic HBV-RNA level and the ratio of intrahepatic HBV-RNA to covalently closed circular DNA (cccDNA), but also with the histological scores for grading and staging. Regarding quasispecies, serum HBV-RNA was dynamic and more genetically homogenous to simultaneously sampled intrahepatic HBV-RNA than to the cccDNA pool. In situ histology revealed that HBV-RNA-positive hepatocytes were clustered in foci, sporadically distributed across the lobules, and co-localized with hepatitis B surface antigen. CONCLUSION: Serum HBV-RNA levels reflect intrahepatic viral transcriptional activity and are associated with liver histopathology in patients receiving NUC therapy. Our study sheds light on the nature of HBV-RNA in the pathogenesis of chronic HBV infection and has implications for the management of chronic hepatitis B during NUC therapy. LAY SUMMARY: Serum HBV-RNA levels are indicative of the intrahepatic transcriptional activity of covalently closed circular DNA and are associated with liver histological changes in patients with chronic B hepatitis who are receiving nucleos(t)ide analogue therapy.

Phylogeographical Analysis Reveals Distinct Sources of HIV-1 and HCV Transmitted to Former Blood Donors in China.

Historically, coinfection of HIV and hepatitis C virus (HCV) was frequent among Chinese former blood donors (FBDs). This is largely due to ignorance/lack of education regarding appropriate sterilizing techniques and/or the availability of single-use needles and equipment. Although HCV shares identical transmission routes with HIV, the source of HCV in the Chinese blood donor population still remains unknown. In this study, we investigated the evolution and transmission of HCV and HIV in the Chinese FBD group. Similar to previous reports, two HCV subtypes (HCV 1b and 2a) and one HIV subtype (Thai-B) were identified in FBDs. The HCV 1b subtype had a similar evolutionary rate of 1.9 × 10-3 substitutions/site/year to that of HIV (2.06 × 10-3 substitutions/site/year), while the HCV 2a subtype had a faster evolutionary rate of 3.8 × 10-3 substitutions/site/year. Phylogeographical analysis indicated that the introduction of HCV 1b into FBDs was estimated to be earlier than that of HCV 2a and HIV (late 1970s vs. late 1980s). Bayesian Skyline Plot (BSP) analysis further confirmed our findings, showing that HCV 1b infections breached a fast exponential growth from 1991 to 1998, while the HCV 2a infections had a fast exponential growth that occurred in around 1996-2001. Overall, this investigation helps to better understand HCV transmission in China and supports improvements of HCV prevalence control.

Roles of CEACAM1 in cell communication and signaling of lung cancer and other diseases.

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is a broadly-expressed immunoglobulin-like cell adhesion molecule with a wide range of biological functions to regulate cell signaling. The present article mainly focuses on the role of CEACAM1 as a therapeutic target in lung diseases and discusses the potential of therapeutic strategies targeting CEACAM1. The article overviews the structure and its sub-types, biological function, and potential roles of CEACAM1 in lung diseases. Alterations of CEACAM1 expression and CEACAM1-S/CEACAM1-L ratio promote the growth and metastasis of non-small cell lung carcinoma (NSCLC). Moreover, CEACAM1 mediates bacterial adherence and transcellular transcytosis, resulting in the suppression of immune cell activities and inflammatory responses, which may trigger acute exacerbation of chronic obstructive pulmonary disease (AECOPD). CEACAM1 plays a critical role in the development of NSCLC and AECOPD and can be a diagnostic biomarker and therapeutic target in lung diseases.