The promising role of monoclonal antibodies for gastric cancer treatment

Diagnostic value of exosome derived long noncoding RNA in gastric cancer in Chinese population: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Objective to systematically evaluate the diagnostic value of long noncoding RNA (lncRNA) in gastric cancer (GC) in the Chinese population.

METHODS

PubMed, Web of Science, EMBASE, Cochrane Library, CNKI, and Wanfang Database were searched. According to the search strategy and inclusion and exclusion criteria, 2 staff members screened the relevant kinds of literature from January 2010 to December 2020 and extracted the relevant data. Revman5.3, Meta-Disc1.4, and Stata15.1 software were used to analyze the relationship between lncRNA from exosomes and the diagnosis of GC. The combined values of sensitivity (SEN), specificity (SPE), positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio (DOR) and their corresponding 95% confidence intervals (CIs) were calculated. The summary receiver operating characteristic curve was drawn and the area under the ROC curve (AUC) value was calculated.

RESULTS

In 9 studies, 1314 samples were included, including 792 cases in the case group and 522 cases in the control group. The combined SEN was 0.82 (95% CI: 0.77-0.86), the combined SPE was 0.78 (95% CI: 0.72-0.83), the combined positive likelihood ratio was 3.7 (95% CI: 2.9-4.6), the negative likelihood ratio was 0.23 (95% CI: 0.18-0.29), and the DOR was 16 (95% CI: 12-23), AUC was 0.87 (95% CI: 0.84-0.90). Subgroup analysis showed that the SEN, SPE, likelihood ratio, DOR, and AUC of plasma-derived lncRNA in the diagnosis of GC were better than those of serum.

CONCLUSIONS

Exosome-derived lncRNA may be a new potential biomarker for the clinical diagnosis of GC.

H. pylori effects on ghrelin axis: Preliminary change in gastric pathogenesis

Ghrelin and its receptors are present in the stomach, suggesting that the ghrelin axis plays an essential role in gastrointestinal complications. This investigation aimed to explore the effects of H. pylori infection and gastritis on serum ghrelin and ghrelin axis gene expression. In this study, we enrolled 68 adult ambulatory people referred for upper gastrointestinal endoscopy. The individuals were classified into three groups based on H. pylori infection and gastritis. Total serum ghrelin and tissue gene expression were tested with ELISA and quantitative RT-PCR, respectively. Serum ghrelin and mRNA expression were significantly lower in H. pylori-positive with gastritis subjects compared with both H. pylori-negative with and without gastritis. Growth hormone secretagogue receptor1a mRNA expression was not different between groups while GHSR1b expression was significantly higher in patients with H. pylori infection and gastritis. We propose the ghrelin axis intermediaries, such as GHSR1b, as a potential clinical target for gastric disorders.

Attribution of Ghrelin to Cancer; Attempts to Unravel an Apparent Controversy

Ghrelin is an endogenous peptide hormone mainly produced in the stomach. It has been known to regulate energy homeostasis, stimulate secretion of growth hormone, and mediate many other physiologic effects. Various effects attributed to ghrelin contribute to many aspects of cancer development and progression. Accordingly, a large body of evidence has emerged about the association of ghrelin with several types of cancer in scales of cell-line, animal, and human studies. However, existing data are controversial. This controversy occurs in two main domains: one is the controversial results in local effects of ghrelin on different types of human cancer cell-lines; the second is the apparent disagreement in the results of in-vitro and clinical studies that investigated ghrelin association to one type of cancer. These inconsistencies have hampered the indications to consider ghrelin as a potential tumor biomarker or therapeutic agent in cancer patients. Previous studies have reviewed different parts of current literature about the ghrelin-cancer relationship. Although they have highlighted these controversial results in various ways, no specific recommendations have been given to address it. In this study, we comprehensively reviewed in-vitro, in-vivo, and clinical studies and attempted to use the following approaches to unravel the inconsistencies detected: (a) to distinguish local and systemic effects of ghrelin in interpreting its summary clinical role in each cancer; (b) scrutinizing factors that regulate local effects of ghrelin and could justify different effects of ghrelin on different cancer cell-lines. These approaches could have notable implications for future in-vitro and clinical studies.