Alli revealed in July that he was sexually abused at the age of six and sold drugs aged eight in a shocking childhood, which created issues that eventually led him to enter rehab earlier this year.
"I think it was extremely brave of Dele to come out and give the interview he gave," said Kane.
"We've known each other for a period of time but I didn't know the extent of what he had been through in his life, for sure.
"It was eye-opening for me to hear that. I texted him afterwards and said how much I think what he did will help a lot of people as well feel comfortable in sharing their feelings and sharing what they've been through."
Alli revealed in his interview that Kane was "brutally honest" as one of the players "that didn't approve of what I was doing" as he tried various coping methods including taking sleeping pills before seeking professional help.
"I caught up with Dele in the summer but that was before the interview," continued Kane. "He seemed to be on a good track. I know he's been working hard to get fit. I can't wait to hopefully see him back out playing football again. I think he is definitely in a better place now.
"He's still got a lot of time left in his career and I'm one person who really hopes he can get back on track and see him playing week in, week out."
Asked whether he had started speaking any German, Kane added: "It hasn't really come along any further yet, to be honest. I'm due to start lessons when I get back, the teacher was away for a little while.
"I'm fully open to trying to learn the language. I've been told it is extremely tough but I want to take in the culture as much as possible and even if I get a word here and there, that would be nice."