Overexpression of metastasis-associated MTA1 in oral squamous cell carcinomas: correlation with metastasis and invasion.

Metastasis-associated protein 1 (MTA1) is physiologically expressed at low levels in human tissues. Its expression is associated with progression of solid cancers and is common in cancer cell lines. This study investigated whether MTA1 was expressed in squamous cell carcinoma (SCC) and would be a useful metastatic marker. Specimens from 38 patients with oral SCC were stained using the avidin-biotin-peroxidase technique with polyclonal antibodies against MTA1. Human SCC cell lines SAS, HSC2, OSC19 and OSC20 were analysed for MTA1 mRNA expression. MTA1 expression in control tissues was significantly lower than in carcinomas. MTA1 protein expression was detected in 33 of 38 SCC tissues from patients. Histologically, MTA1 protein production was strongly associated with cancer cell invasion, and clinically there was a correlation between lymph node metastasis and MTA1 protein production. Among the cancer cell lines, HSC2 showed the lowest mRNA expression, and OSC20 showed the highest MTA1 mRNA expression. In the Matrigel invasion assay, the HSC2 cell line showed the lowest invasion and the OSC20 cell line showed the highest invasion. RNAi-mediated MTA1 silencing in the OSC20 cells decreased the invasion index. MTA1 expression in oral SCC may be associated with increased invasive ability, which may cause lymph node metastasis.

Augmentation of lung antineutrophil elastase capacity with recombinant human alpha-1-antitrypsin.

To evaluate the potential use of recombinant DNA-produced alpha-1-antitrypsin (alpha-1-AT) to augment the lung antineutrophil elastase defenses in alpha-1-AT deficiency, we compared the kinetics of intravenously administered recombinant produced alpha-1-AT (r alpha-1-AT) and purified normal human plasma alpha-1-AT (p alpha-1-AT) in the blood and lung of rhesus monkeys. The r alpha-1-AT was produced in yeast transformed with an expressing plasmid containing a full-length human alpha-1-AT complementary deoxyribonucleic acid and purified to greater than 99% homogeneity. The r alpha-1-AT has a molecular weight of 45,000, no carbohydrates, and is identical in sequence to normal plasma alpha-1-AT except for an additional N-terminal acetylmethionine. Despite its lack of carbohydrates, the r alpha-1-AT inhibited human neutrophil elastase with an association rate constant similar to that of p alpha-1-AT. Rhesus monkeys were infused intravenously with 120 mg/kg of r alpha-1-AT (n = 13) or p alpha-1-AT (n = 12) and the serum, urine, and lung epithelial lining fluid (ELF) concentrations of these molecules quantified at various intervals.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrastructural and biochemical studies of the effect of polychlorinated biphenyl on mouse parotid gland cells.

These effects of polychlorinated biphenyl (PCB) were examined by light and electron microscopy and biochemical analysis of lysosomal enzyme activities. Several experimental protocols with dosage schedules of either 0.2, 2.0, or 20 mg/kg of PCB were used. Typical histological changes were observed in mice given 2 mg/kg of PCB in a single injection. There were no remarkable changes until 4 days after PCB administration; marked cytoplasmic vacuolation was observed in parotid acinar cells at 7 days. The activities of lysosomal enzymes increased after the PCB injection and their maximum values appeared consistently at 4 days after the treatment; the increases were threefold for acid phosphatase, twofold for beta-glucuronidase, threefold for cathepsin D, fivefold for cathepsin H and twofold for cathepsin L. As vacuolation was preceded by a large increase in lysosomal enzyme activities and the vacuoles co-localized with lysosomes, it is suggested that an increase in these activities induced by PCB may be closely related to the development of vacuolation in the parotid acinar cells as a subacute effect of PCB.

Juvenile hyaline fibromatosis complicated with oral squamous cell carcinoma: a case report.

A 45-year-old woman was referred because of swelling of the palate, gingival hypertrophy, and multiple cutaneous tumors. She had many cutaneous tumors, which covered most of her body, and she also displayed contractures of the major joints. Maxillary and mandibular gingival hypertrophy, malposition of the teeth, and swelling of the hard palate were the oral findings. The histopathologic features of the cutaneous and gingival tumors were consistent with hyaline fibromatosis, and the swelling of the palate proved to be a squamous cell carcinoma. The carcinoma was treated with tegafur/uracil and seemed to respond to this therapy.

Malignant lymphoma of the mandible: report of a case.

Extranodal malignant lymphoma is relatively rare. When it occurs in the oral region, it is sometimes misdiagnosed as inflammatory disease. This report details a case of malignant lymphoma that involved the fight mandibular region.

Clinicopathological risk factors for local recurrence in oral squamous cell carcinoma.

Local recurrence of oral squamous cell carcinoma (OSCC) after primary surgery has been considered to be a poor prognostic entity in terms of survival rate. The purpose of this study is to evaluate the incidence of local recurrence and to identify significant risk factors for the local recurrence in OSCC. The authors retrospectively reviewed records for 187 patients who underwent radical surgery for OSCC. The local recurrence rate was 16.0% (30/187 patients) in this study. The survival rate of patients with local recurrence was 33.3%, which was significantly lower than that (94.3%) of patients without local recurrence. Pattern of invasion (POI), neoadjuvant chemotherapy (NAC), and the status of the surgical margin were identified as factors influencing local recurrence. In particular, NAC and the status of the surgical margin were independent risk factors by multivariate analysis. The deep margin was resected at a close site in many NAC-treated patients, suggesting that NAC may lead to local recurrence and poor outcomes. No efficacy of NAC was observed, suggesting that the standard treatment of oral cancers is surgery alone.

RNAi-mediated down-regulation of alpha-actinin-4 decreases invasion potential in oral squamous cell carcinoma.

alpha-actinin-4, originally identified as an actin-binding protein associated with cell motility, invasion, and metastasis of cancer cells, appears to be overexpressed in various human epithelial carcinomas, including colorectal, breast, esophageal, ovarian, and non-small cell lung carcinomas. The authors evaluated whether alpha-actinin-4 might be appropriate as a molecular target for cancer gene therapy. In 64 primary oral squamous cell carcinomas (OSCCs) and 10 normal oral mucosal specimens, and in seven human OSCC cell lines, alpha-actinin-4 expression was evaluated immunologically and correlations with clinicopathologic factors were examined. Overexpression of alpha-actinin-4 was detected in 38 of 64 oral squamous cell carcinomas (70%); significantly more frequently than in normal oral mucosa. The expression of alpha-actinin-4 was significantly associated with invasion potential defined by the Matrigel invasion assay. Cancer cell lines with higher alpha-actinin-4 expression had greater invasive potential. An RNAi-mediated decrease in alpha-actinin-4 expression reduced the invasion potential. These results indicated that the overexpression of alpha-actinin-4 was associated with an aggressive phenotype of OSCC. The study indicated that alpha-actinin-4 could be a potential molecular target for gene therapy by RNAi targeting for OSCC.

Nucleotide sequence of the triose phosphate isomerase gene of Saccharomyces cerevisiae.

The gene coding for the glycolytic enzyme triose phosphate isomerase (TPI1) was isolated from a yeast library in the shuttle vector pYE13. Selecting for a deletion mutant of the plasmid which enhances expression of the otherwise dormant yeast gene in E. coli facilitated the identification of the coding region. The DNA sequences of the wild type and mutant genes were determined by chemical methods. The 5' flanking region of the wild-type TPI1 resembles the analogous regions of the yeast genes coding for two other glycolytic enzymes. The sequence of the deletion mutant indicates that, upstream from -65 in the 5' flanking region, 3.3 kilobases have been lost from entirely within the yeast insert. The mutation reduces enzyme activity by tenfold in yeast, and its implications for the expression of the gene in yeast and E. coli are discussed. The amino acid sequence deduced from the nucleotide order is consistent with the electron density map of the protein as well as the sequence of its N-terminal 16 amino acids and amino acid composition. The amino acid sequence is approximately 50% homologous with the triose phosphate isomerases from rabbit, chicken, and coelacanth and 37% homologous with the Bacillus stearothermophilus enzyme. Residues which are thought to be catalytically important are conserved.

Induction of drug metabolizing enzymes by polychlorinated biphenyl in the parotid gland and relation to changes in vitamin A content and morphological changes.

The relationship between the morphological changes and vitamin A content during the development of acute toxicity induced by polychlorinated biphenyl (PCB) in mouse parotid glands was investigated. PCB was administered intraperitoneally at a single dose of 2 mg/kg. Ultrastructural studies revealed remarkable morphological changes in the rough endoplasmic reticulum, nucleus, Golgi apparatus and the secretory granules at 7 days after the administration of PCB. The activities of adenosine monophosphatase (AMPase) and alkaline phosphatase were increased 1 day after PCB administration. Then the activity of NADPH-cytochrome c reductase increased 4 days after PCB administration. Subsequently, the vitamin A content of the parotid glands significantly decreased at 7 days compared with the control. These sequential changes in enzyme activities implied that the decrease of vitamin A content in the parotid glands may be partly due to catabolism of vitamin A by increased activities of microsomal enzymes induced by PCB. In conclusion, it is suggested that PCB also induces drug metabolizing enzymes in the parotid gland cells and that the acute toxicity of PCB on this tissue may occur, at least partly, through the reduction of vitamin A not only by the secondary effect from liver impairment but also by the locally accelerated catabolism of vitamin A in the mouse parotid gland.

Cloning of genes that complement yeast hexokinase and glucokinase mutants.

Genes complementing the glucose-negative fructose-negative Saccharomyces cerevisiae triple mutant strain (hxkl hxk2 glk1), which lacks hexokinase PI, hexokinase PII, and glucokinase, were obtained from a pool of yeast DNA in the multicopy plasmid YEp13.

Sequence of the Ampullariella sp. strain 3876 gene coding for xylose isomerase.

The nucleotide sequence of the gene coding for xylose isomerase from Ampullariella sp. strain 3876, a gram-positive bacterium, has been determined. A clone of a fragment of strain 3876 DNA coding for a xylose isomerase activity was identified by its ability to complement a xylose isomerase-defective Escherichia coli strain. One such complementation positive fragment, 2,922 nucleotides in length, was sequenced in its entirety. There are two open reading frames 1,182 and 1,242 nucleotides in length, on opposite strands of this fragment, each of which could code for a protein the expected size of xylose isomerase. The 1,182-nucleotide open reading frame was identified as the coding sequence for the protein from the sequence analysis of the amino-terminal region and selected internal peptides. The gene initiates with GTG and has a high guanine and cytosine content (70%) and an exceptionally strong preference (97%) for guanine or cytosine in the third position of the codons. The gene codes for a 43,210-dalton polypeptide composed of 393 amino acids. The xylose isomerase from Ampullariella sp. strain 3876 is similar in size to other bacterial xylose isomerases and has limited amino acid sequence homology to the available sequences from E. coli, Bacillus subtilis, and Streptomyces violaceus-ruber. In all cases yet studied, the bacterial gene for xylulose kinase is downstream from the gene for xylose isomerase. We present evidence suggesting that in Ampullariella sp. strain 3876 these genes are similarly arranged.

High-affinity peptide ligands to prostate-specific antigen identified by polysome selection.

We have used the polysome-selection method to isolate peptide ligands that bind with high affinity to Prostate-Specific Antigen (PSA), an important prostate-cancer marker. Two random libraries, each encoding approximately 10(12) random peptides, were transcribed into RNA and translated in vitro. Polysomes were panned by affinity selection of the nascent peptides against immobilized PSA. Over 30% of the selected species had significant affinity for PSA; the dissociation constant of the complex formed by the best isolate with PSA was < 10(-9) M. Formation of streptavidin conjugates of selected peptides improved their affinities and, in one case, virtually eliminated non-specific binding. The polysome-selection method can be used to produce high-affinity peptide ligands of potential use in diagnostic and therapeutic procedures.