The growth arrest-specific gene CCN5 is deficient in human leiomyomas and inhibits the proliferation and motility of cultured human uterine smooth muscle cells.

Uterine fibroids (leiomyomas) are a major women's health problem. Currently, the standard for treatment remains hysterectomy, since no other treatment modalities can reduce both symptoms and recurrence. As leiomyomas are benign neoplasias of smooth muscle cells, we sought to understand the regulation of uterine smooth muscle cell mitogenesis by CCN5, a growth arrest-specific gene in vascular smooth muscle cells which is induced and maintained by heparin treatment. Using autologous human myometrial and leiomyoma smooth muscle cells, we demonstrate that the proliferation and motility of both cell types are inhibited by the overexpression of CCN5. Surprisingly, we show that even though CCN5 is induced by heparin in vascular smooth muscle cells, treatment with heparin does not induce CCN5 expression in human uterine smooth muscle cells. Furthermore, we examine CCN5 mRNA expression in 10 autologous pairs of human myometrial and leiomyoma tissues and determine that CCN5 is down-regulated in 100% of the leiomyoma tissues analysed when compared to their normal myometrial counterparts. Thus, our data strongly suggest that CCN5 may exert an important function in maintaining the normal uterine phenotype and that loss of the anti-proliferative protein CCN5 from normal myometrium may account, at least in part, for tumorigenesis.

Sequential hydrolysis of swine carcass samples and determination of amino acid concentrations using pre-column derivatization with phenyl isothiocyanate.

Comparing amino acid (AA) retention levels in pig carcass to true ileal digestible AA intake provides an estimate of the marginal efficiency of AA utilization. Accurate analysis of AA levels in the carcass samples is critical. However, the standard 24 h of hydrolysis does not always provide maximum AA values. A study was carried out to investigate the effect of hydrolysis time on AA measurements in pig carcass. Correction factors to standardize AA levels to 24 h of hydrolysis were also determined. Ground carcass samples were hydrolysed with 6 mol litre-1 hydrochloric acid (HCl) in a 110 °C oven for nine different time periods. Pre-column derivatization with phenyl isothiocyanate (PITC) was used to determine AA concentrations in all of the samples. Hydrolysis time significantly affected (P < 0.001) AA levels. The highest levels (P > 0.05) of valine, isoleucine, serine, glycine, threonine, alanine, arginine, proline, histidine and phenylalanine were not observed with 24 h hydrolysis. Therefore, correction factors and sequential hydrolysis curves are important for these amino acids. In conclusion, the effect of hydrolysis time should be considered in amino acids analysis. © 2000 Society of Chemical Industry.