The present invention relates to the field of diagnostic and treatment of cancer, particularly melanoma, pancreatic cancer, kidney cancer and colon cancer. In particular, the invention relates to an antibody directed specifically to CD146-positive tumors and its applications, particularly for use as a medicament for the prevention and/or treatment of cancer, for use in a method of diagnostic or prognostic of a cancer, or for use as a radiotracer when labelled with a radioactive element.