Shigeyuki Morioka

Different expression of alkaline phosphatase in subclones of human neoplastic salivary duct cell line

Human neoplastic salivary cell line (HSGc) and its subclones express alkaline phosphatase (AP) which is sensitive to L-phenylalanine but insensitive to L-homoarginine. Electrophoretic analysis demonstrates two distinct bands of AP, one (sb-1) is heat-stable and another (sb-2) is rather heat-labile and faster mobility than sb-1. The AP activity, especially sb-2, shows high level in less-differentiated clone (HSGc-C5) with increased growth rate but low level in nontumorigenic and well-differentiated clone (HSGc-E1) as compared to parent HSGc. This may suggest that the AP is a possible marker for identification of undifferentiated state in HSGc. This study also indicates that dibutyryl cAMP produces an increase of heat-labile AP in these clones.

Different contents of glycosaminoglycans in a human neoplastic salivary duct cell line and its subclone with a myoepithelial phenotype.

SummaryThe glycosaminoglycans (GAG) biosynthesized by a neoplastic human salivary duct cell line, HSGc, and by its nontumorigenic subclone, HSGc-E1, having a myoepithelial-like phenotype, were examined by incorporation of [3H]-acetate into GAG. The rate of GAG radiolabeling in HSGc-E1 was significantly greater than that in HSGc. The radiolabeled GAG recovered from HSGc-E1 showed a distribution of 22–32% in the cells and 68–78% secreted into the medium, while the amounts of GAG in the cells and medium of HSGc were equal. Two-dimensional electrophoresis of GAG extracted from the cells demonstrated that HSGc-E1 contained a much greater amount of heparan sulfate (HS, 53.5% of total), while HSGc synthesized hyaluronic acid (HA, 17.5%), HS 38.8%, chondroitin sulfate (Ch-S, 27.6%) and dermatan sulfate (DS, 16.1%). Moreover, treatment of HSGc with sodium butyrate or dibutyryl cyclic AMP (each is a potent inducer of differentiation to myoepithelial-like cells) strongly enhanced GAG synthesis, while dexamethasone (an inducer of differentiation to a more functional duct epithelium) did not stimulate GAG synthesis. These findings suggest that biosynthetic changes in the GAG content of neoplastic salivary cells are associated with their myoepithelial differentiation.

Serum a-1 -antitrypsin in patients with malignant tumors occurring in the oral region

In the present study, we have examined the immunoreactive levels of alpha-1-antitrypsin (AAT) and trypsin-inhibitory capacity (TIC) in the serum of patients with malignant tumors occurring in the oral region. AAT in the MFH group showed significantly high (468 +/- 129 mg/dl, mean +/- SD (n = 4)) as compared to those of other types of sarcoma groups (236 +/- 28 mg/dl, (n = 5)) and healthy controls (226 +/- 36 mg/dl, (n = 75)) (p less than 0.05). Patients with squamous cell carcinoma (SCC) also had increased levels of AAT (269 +/- 35 mg/dl, (n = 18)), but there was no significant difference among other groups including healthy controls. TIC of patients with MFH was higher (2.29 +/- 0.42 IU/ml, (n = 4)) than in the SCC group (1.44 +/- 0.25 IU/ml, (n = 18)), other sarcoma groups 1.21 +/- 0.16 IU/ml, (n = 5)) and controls (1.55 +/- 0.15 IU/ml, (n = 75)). These data suggest that the elevation of AAT and TIC would be helpful in the diagnosis of MFH.