It’s over for Charlie Brown, Snoopy and the rest of the “Peanuts” gang. Charles M. Schulz, 77, creator of the comic strip “Peanuts,” announced on Tuesday that he will retire. Schulz, who earlier this month was diagnosed with cancer, is currently undergoing treatment for the disease. “He’s sad about it,” his wife, Jean Schulz, told the Associated Press. Publication of the popular strip will cease on Jan. 4, after the last original strip runs. Schulz became a cartoonist following a stint in the Army. He responded to a “Do you like to draw?” ad and was soon selling cartoons to the Saturday Evening Post. The syndicated comic strip “Peanuts” debuted in 1950 and was an international hit, running in more than 2,600 newspapers and becoming the basis of numerous TV specials, including the 1965 Emmy-winning “A Charlie Brown Christmas.”