The present invention provides methods for treating cancer using GRK2 inhibitors such as small molecule inhibitors of GRK2 among others. The invention also features compositions containing GRK2 inhibitors, methods of diagnosing patients with GRK2-associated cancer and methods of predicting the response of cancer in a subject to treatment with GRK2 inhibitors.

This invention is generally related to novel compositions for treating or preventing heart failure. Specifically, the disclosure provides a composition comprising an amino-terminal domain of Beta.adrenergic receptor kinase-1 (Beta.ARKnt) peptide, or a nucleic acid encoding Beta.ARKnt. Further disclosed are methods of using the compositions for treating or preventing heart failure in a subject or for altering Beta.-adrenergic receptor (Beta.AR) density in a subject.

Methods of alleviating the symptoms of hemoglobinopathies, including, but not limited to, sickle cell disease, -thalassemia, and hemoglobin H disease are provided. In some embodiments, the methods comprise administering an inhibitor selected from a -arrestin1/2 inhibitor and/or a GRK2 inhibitor to the subject. Methods of inhibiting adhesion of sickle red blood cells to endothelial cells and adhesion to and activation of leukocytes are also provided.