Project description:We studied the lncRNA and mRNA expression in 6 advanced resected GA (ARGA) tissues using a lncRNA microarray chip. Among 22,870 lncRNAs expressed in ARGA and paired non-neoplastic tissues (non-GA), 1,769 and 1,710 were up- or down- regulated, respectively in all 6 ARGA tissues (≥2.0-fold, p<0.05).
Project description:In this study, we presented a new HER2 protein detection method based on mass spectrometry selected reaction monitoring (MS-SRM), determined the upper and lower limits of HER2 expression detection, and validated the method. We conducted a retrospective study on 118 formalin-fixed paraffin-embedded (FFPE) tissues from patients with advanced gastric adenocarcinoma in northern China.
Project description:Cancer cells have wide variety of gene expression profile. The objective of the study is to reveal the cancer-associated gene expression profile. Microarray analysis was used to investigate gene expression of cancer cells. Both gastric and pancreatic cancer tissues were surgically resected and total RNA was purified from these tissues by a conventional method.
Project description:COVID-19 typically manifests as a respiratory illness but several clinical reports described gastrointestinal (GI) symptoms. This is particularly true in children, whom GI symptoms are frequent and viral shedding outlasts viral clearance from the respiratory system. These observations raise the question of whether the virus can replicate within the stomach. Here we show the novel derivation of gastric organoids from fetal, pediatric and adult biopsies and prove their value as in vitro models for SARS-CoV-2 infection. To facilitate infection, we induced a reversed polarity in our organoids (RP-GOs). The pediatric RP-GOs are fully susceptible to infection with SARS-CoV-2, while the viral replication is significantly lower in organoids of fetal and adult origin. Transcriptomic analysis shows a moderate innate antiviral response and the lack of differentially expressed genes belonging to the interferon family. Collectively, we show how the virus can efficiently infect gastric epithelium, suggesting that the stomach might have an active role in fecal-oral SARS-CoV-2 transmission.
Project description:Sonic Hedgehog (SHH) signaling is a key regulator of embryonic development and tissue homeostasis, and is involved in gastrointestinal (GI) cancer progression. Here we show that SHH gene expression is down-regulated by chemotherapy drugs. The 139Kb upstream enhancer is specifically targeted by the immediate early gene EGR1.
Project description:Gastrointestinal (GI) motility disorders affect millions of people worldwide, yet remain poorly treated due to insufficient knowledge of the molecular networks controlling GI motility. Interstitial cells of Cajal (ICC) are critical GI pacemaker cells, and abnormalities in ICC are implicated in GI motility disorders. Nevertheless, human ICC are poorly characterised, largely due to difficulties in accessing sufficient numbers for research. Two cell surface proteins have been identified as ICC markers: the receptor tyrosine kinase, KIT; and the calcium-activated chloride channel, Anoctamin-1 (ANO1). Anti-KIT antibodies have been used to purify mouse ICC via flow cytometry. Here, we performed single-cell RNA sequencing of KIT-sorted, primary human gastric ICC to better understand networks controlling human ICC biology.
Project description:Protein-based targeting reagents, such as antibodies and non-antibody scaffold proteins, are rapidly inactivated in the upper gastrointestinal (GI) tract. Hydrochloric acid in gastric juice denatures proteins and activates pepsin, concentrations of which reach 1 mg/mL in the mammalian stomach. Here we present gastrobodies, a protein scaffold derived from Kunitz soybean trypsin inhibitor (SBTI). SBTI is highly resistant to the challenges of the upper GI tract, including digestive proteases, pH 2 and bile acids. Computational prediction of SBTI’s evolvability identified two nearby loops for randomization, to create a potential recognition surface which was experimentally validated by alanine scanning. We established display of SBTI on full-length pIII of M13 phage. Phage selection of gastrobody libraries against the glucosyltransferase domain of Clostridium difficile toxin B (GTD) identified hits with nanomolar affinity and enzyme inhibitory activity. Anti-GTD binders retained high stability to acid, digestive proteases and heat. We use mass spectrometry to identify cut sites outside of the gastrobody.