Cat Women of the Moon: Classic Sci-Fi « Movie from 1953

Somewhere in the near future, the people of Earth send an expedition to the moon. Deep within a remote cave they encounter the last remaining survivors of a 2 million year old race - the Cat Women.

Existing in the only location that still has breathable air, the era of the Cat Women will soon come to an end. But now they have an escape route. They plot to steal Earth's spaceship and migrate.