Humoral hypercalcemia of malignancy: some enigmas on the clinical features.
Humoral hypercalcemia of malignancy (HHM) is a common paraneoplastic syndrome mediated by tumor-derived parathyroid hormone-related peptide (PTHRP), which bears structural and functional similarities to PTH. Thus the clinical features of HHM are very similar to those of primary hyperparathyroidism (1 degree HPT), a prototype of humoral hypercalcemia caused by PTH. On the other hand, HHM syndrome differs from 1 degree HPT in several aspects, including serum 1,25(OH)2D levels, acid-base balance, and bone remodeling process, the reason of which remains largely unknown. We approached these questions using a unique animal model of HHM, nude rats implanted with PTHRP-overproducing human carcinomas. In this review we will summarize the results and discuss the implications in understanding the disease mechanism.
Ikeda
K
K
Fourth Department of Internal Medicine, University of Tokyo School of Medicine, Japan.
Ogata
E
E
D000818:Animals; D006801:Humans; D006934:Hypercalcemia / Q000209:etiology*; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics; D009369:Neoplasms / Q000097:blood*; D009374:Neoplasms, Experimental / Q000097:blood; D010257:Paraneoplastic Syndromes / Q000097:blood*; D010281:Parathyroid Hormone / Q000737:chemistry; D044162:Parathyroid Hormone-Related Protein; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry / Q000235:genetics; D051381:Rats
D009363:Neoplasm Proteins; C470121:PTHLH protein, human; D010281:Parathyroid Hormone; D044162:Parathyroid Hormone-Related Protein; D011506:Proteins