This is what I got on internet -
1. Go to settings app.
2. After opening the settings app go to personal -> Accounts section. Open accounts.
3. There you might see several accounts configured based on the apps which you might have installed on your device. In my case I saw several accounts for few apps namely Google, WhatsApp, Telegram etc. Exactly on this screen you will also see an account named UCNews.
4. I simply removed the UC News account from there.
After the removal of the UC News account, the UC news app will not be reinstalled on its own.