Humoral hypercalcemia of malignancy

Effects of recombinant human parathyroid hormone (1-34)on cell proliferation, chemokine expression and the Hedgehog pathway in keratinocytes

Psoriasis is an autoimmune disease involving the excessive proliferation of keratinocytes mediated by T‑cells. Parathyroid hormone (PTH) has been identified as an essential factor in the treatment of psoriasis. In the present study, the mechanism underlying the effect of recombinant human parathyroid hormone (rhPTH) (1‑34) in keratinocytes was investigated. The effects of rhPTH (1‑34) on cell proliferation, cell cycle, and the secretion and expression of C‑X‑C motif chemokine 11 (CXCL11) and components of the Hedgehog signaling pathway were examined in HaCaT cells by MTT assay, flow cytometric analysis, ELISA and gene chip analysis. The data showed that rhPTH (1‑34) significantly inhibited keratinocyte proliferation at concentrations >8x10‑7 mol/l. rhPTH (1‑34) induced G1 phase arrest of the cell cycle in the keratinocytes. The secretion of CXCL11 in tumor necrosis factor (TNF)‑α‑induced keratinocytes was downregulated by rhPTH (1‑34) in a dose‑dependent manner, compared with that in keratinocytes treated with TNF‑α alone. It was also found that rhPTH (1‑34) inhibited the expression of CXCL11 in the HaCaT cells. rhPTH (1‑34) also affected the Hedgehog signaling pathway specifically by regulating the expression of associated genes. In conclusion, these data suggested that rhPTH (1‑34) inhibited cell proliferation, and the secretion and expression of CXCL11 in HaCaTs. rhPTH (1‑34) also altered the expression of associated genes in the Hedgehog pathway. Therefore, rhPTH (1‑34) can be considered as a novel therapeutic agent for the treatment of psoriasis.

Establishment of two human small cell lung cancer cell lines: the evidence of accelerated production of parathyroid hormone-related protein with tumor progression

Two small cell lung cancer (SCLC) cell lines have been established from malignant effusions obtained from an SCLC patient with hypercalcemia during a 3-month follow-up period. The two cell lines established were shown to transcribe the parathyroid hormone-related protein (PTHrP) gene and to constantly secrete fairly large amounts of PTHrP into the culture medium. The efficiency of PTHrP gene transcription and secretion was greater in the cell line established in the late stage (KOT-2) as compared with that obtained in the early stage (KOT-1). Immunohistochemical studies showed that these cells also coexpress neuroendocrine (NE) products such as chromogranin A and neuron-specific enolase (NSE).

Humoral Hypercalcemia of Hepatocellular Carcinoma Associated with Elevated Levels of Parathyroid-Hormone-Related-Peptide

Parathyroid-hormone-related-peptide (PTHrP) has been shown to be important in the pathogenesis of hypercalcemia of malignancy. The malignancies most commonly associated with hypersecretion of PTHrP include squamous cell carcinoma and breast cancer. The pathogenesis of hypercalcemia associated with hepatocellular carcinoma was evaluated in this study. Two male patients with hepatocellular carcinoma were found to have severe hypercalcemia at initial presentation. PTHrP was measured with radioimmunoassay in these two patients before treatment as well as in nine other patients with hepatocellular carcinoma but without hypercalcemia. The levels were markedly elevated in the two patients with hypercalcemia (29.3 and 32.1 pM), but were less than 5 pM in the nine patients without hypercalcemia. These results suggest that PTHrP was important in the pathogenesis of hypercalcemia associated with hepatocellular carcinoma in these men.

Hepatic localization of a fibrosarcoma in a child with a liver transplant

Two years after an orthotopic liver transplantation, a multifocal hepatic tumor with lymphonodular metastases, identified as a fibrosarcoma, developed in a 4-year-old girl being treated with cyclosporine. On a needle biopsy sample, genetic typing of the HLA-DR group revealed that tumoral cells were from the recipient.