ABSTRACT
BACKGROUND AND AIM: Tumor progression and distant metastasis are the main causes of deaths in gastric cancer. Growing evidence revealed that circular RNAs (circRNAs) play critical role in the pathology of malignant disease, the role of circRNAs in gastric cancer progression and metastasis is still unknown. METHODS: Differentially expressed circRNAs was identified by circRNA microarray and validated by quantitative reverse transcription polymerase reaction. The biological function of circTNIK was evaluated by in vitro and in vivo experiments after ectopic expression or siRNA mediated knockdown of circTNIK. The interaction between circTNIK and miR-138-5p was determined by luciferase activity assay, RNA immunoprecipitation, and fluorescence in situ hybridization assays. RESULTS: circTNIK rather than linear TINK mRNA was significantly upregulated in gastric cancer tissues, cell lines compared with normal controls. Higher circTNIK expression was correlated with aggressive tumor phenotypes and poor overall survival in gastric cancer patients. Ectopic circTNIK expression promoted cell proliferation, invasion, tumorigenesis, and metastasis in gastric cancer cells whereas knockdown of circTNIK inhibited cell proliferation, invasion, tumorigenesis, and metastasis in gastric cancer cells. Importantly, circTNIK functions as a molecular sponge for miR-138-5p to regulate the expression of ZEB2. CONCLUSIONS: Overall, our study demonstrates how circTNIK regulates gastric cancer progression and metastasis by sponging miR-138-5p to modulate the expression of ZEB2. CircTNIK might be used as a prognostic biomarker in gastric cancer patients.
Subject(s)
MicroRNAs , Stomach Neoplasms , Humans , RNA, Circular/genetics , MicroRNAs/genetics , MicroRNAs/metabolism , Stomach Neoplasms/pathology , In Situ Hybridization, Fluorescence , Cell Line, Tumor , Carcinogenesis/genetics , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic/genetics , Cell Movement , Zinc Finger E-box Binding Homeobox 2/genetics , Zinc Finger E-box Binding Homeobox 2/metabolismABSTRACT
Introduction: Gastric cancer (GC) complicated by bone marrow metastasis (BMM) and disseminated intravascular coagulation (DIC) represents poor prognosis and most of these patients would die in a few months. Active treatment strategies such as chemotherapy are effective in restoring coagulation function and prolonging patients' survival time. Immunotherapy including programmed death protein 1 (PD-1) or programmed death protein ligand 1 (PD-L1) inhibitors has emerged as a first-line treatment of gastric cancer. However, the efficacy of PD-1 inhibitor-based treatment strategies in these patients remains unknown. Case description: Herein, we presented two cases of advanced gastric cancer (AGC) complicated by BMM and DIC, in which two patients received chemotherapy and PD-1 inhibitor as the first-line treatment. Both of them achieved a partial response after treatment, and the coagulation function was restored. The patient who discontinued the PD-1 inhibitor after 6 months experienced DIC relapse, whereas the other patient who maintained the PD-1 inhibitor treatment cycle remained responsive after 10 months. Conclusions: We speculate that PD-1 inhibitor-based treatment strategies are effective and safe in prolonging survival against gastric cancer with BMM and DIC, and the coagulation function is well controlled by the treatment with a combination of immunotherapy and chemotherapy.
ABSTRACT
BACKGROUND: Signet ring cell carcinoma (SRCC) is a specific type of gastric cancer. The clinicopathological and molecular characteristics that can be used to predict the response to anti-PD-1 therapy for these patients are still not clear. METHODS: Patients with advanced SRCC who received first-line anti-PD-1-based treatment were enrolled in this study. The clinicopathological characteristics of these patients were obtained from their medical records. The molecular features of these patients were analyzed by means of a next-generation-sequencing-based panel. The predictive significance of clinicopathological and molecular features for efficacy was analyzed. RESULTS: A total of 71 patients with measurable lesions were included in this study, among which 46 patients had enough tissues for next-generation sequencing. The overall objective response rate (ORR) was 46.4%. ORR was significantly higher in mismatch repair (MMR)-deficient (dMMR) patients than in MMR-proficient (pMMR) patients, in patients with lymph node metastasis only than those with other metastasis sites, and in patients with an Eastern Cooperative Oncology Group performance status (ECOG PS) of 0 than with a PS of 1 or 2. The progression-free survival was significantly longer in patients with dMMR, lymph node metastasis only, PD-L1 combined positive score (CPS) ≥ 5, and CDH1 wild type. CONCLUSIONS: Several clinicopathological and molecular features are associated with anti-PD-1 treatment efficacy in SRCC, which might be used to identify patients who can benefit most from these therapies.
