Aspects of the present invention relate to methods and reagents for increasing chemosensitivity to platinum-based chemotherapy. In one aspect, a method of increasing chemosensitivity to platinum-based chemotherapy is provided, comprising administering to a patient in need thereof an effective amount of an endotrophin-neutralizing agent. The agent can be a monoclonal antibody, or fragment thereof, capable of binding to the C5 domain of the alpha3 chain of collagen VI. In some embodiments, the method can further include administering an effective amount of thiazolidinedione to said patient.