RESUMO
Long non-coding RNA KCNQ1OT1 is highly expressed in a variety of tumors, but there are few studies in gastric cancer and the results are inconsistent. The relevant research of its specific mechanism in gastric cancer is also scarce. Through the analysis of several TCGA public databases, we found that KCNQ1OT1 was generally highly expressed in gastric cancer, and the prognosis of gastric cancer patients with a high expression of KCNQ1OT1 was poor. The expression of KCNQ1OT1 is closely related to many clinical factors of gastric cancer, especially the mutation of TP53, and its expression is significantly related to immune cell infiltration. KCNQ1OT1 is generally highly expressed in gastric cancer cell lines. Knockdown of KCNQ1OT1 can inhibit the proliferation of gastric cancer cell lines. Co- expression network analysis showed that its expression was closely related to tumor metabolism. Glutaminase 1 (GLS1) is generally highly expressed in gastric cancer, which is closely related to a poor prognosis. There is a significant correlation between the expression of KCNQ1OT1 and GLS1. Knockdown of KCNQ1OT1 can inhibit the expression of GLS1 mRNA, and overexpression of GLS1 can partially rescue the proliferation of gastric cancer cells caused by knockdown of KCNQ1OT1. Therefore, we speculate that KCNQ1OT1 may regulate the growth of gastric cancer cells through GLS1. Our study explored the role of KCNQ1OT1 in gastric cancer through bioinformatics database and experiments, suggesting that KCNQ1OT1 may promote the development of gastric cancer by regulating glutamine metabolism, which provides a new target for the clinical research on targeted treatment in gastric cancer.
RESUMO
BackgroundRapid spread of SARS-CoV-2 in Wuhan prompted heightened surveillance in Guangzhou and elsewhere in China. Modes of contact and risk of transmission among close contacts have not been well estimated. MethodsWe included 4950 closes contacts from Guangzhou, and extracted data including modes of contact, laboratory testing, clinical characteristics of confirmed cases and source cases. We used logistic regression analysis to explore the risk factors associated with infection of close contacts. ResultsAmong 4950 closes contacts, the median age was 38.0 years, and males accounted for 50.2% (2484). During quarantine period, 129 cases (2.6%) were diagnosed, with 8 asymptomatic (6.2%), 49 mild (38.0%), and 5 (3.9%) severe to critical cases. The sensitivity of throat swab was 71.32% and 92.19% at first to second PCR test. Among different modes of contact, household contacts were the most dangerous in catching with infection of COVID-19, with an incidence of 10.2%. As the increase of age for close contacts and severity of source cases, the incidence of COVID-19 presented an increasing trend from 1.8% (0-17 years) to 4.2% (60 or over years), and from 0.33% for asymptomatic, 3.3% for mild, to 6.2% for severe and critical source cases, respectively. Manifestation of expectoration in source cases was also highly associated with an increased risk of infection in their close contacts (13.6%). Secondary cases were in general clinically milder and were less likely to have common symptoms than those of source cases. ConclusionsIn conclusion, the proportion of asymptomatic and mild infections account for almost half of the confirmed cases among close contacts. The household contacts were the main transmission mode, and clinically more severe cases were more likely to pass the infection to their close contacts. Generally, the secondary cases were clinically milder than those of source cases.
