Rocker Joan Jett signed an autograph Wed., March 17, in front of the Bowery Hotel, where the after party was held for the premiere of “The Runaways” at the Landmark Sunshine Cinema, on E. Houston St. Starring Dakota Fanning and Kristen Stewart, the film portrays the pioneering girl group through the eyes of Jett and lead singer Cherie Currie during the mid-1970s, charting the band’s rise to stardom.