Differentiating Thyroid Follicular Adenoma from Follicular Carcinoma via G-Protein Coupled Receptor-Associated Sorting Protein 1 (GASP-1).

Follicular neoplasms are classified as benign or malignant depending on the presence or absence of capsular and/or vascular invasion. Due to incomplete capsular penetration or equivocal vascular invasion, the evaluation of these features can be challenging using histologic examination. In the current study, we analyzed the involvement of G-protein coupled receptor-associated sorting protein 1 (GASP-1) in the development and progression of thyroid neoplasms. Affinity-purified anti-GASP-1 polyclonal antibodies were used for routine immunohistochemistry (IHC) analysis. Thyroid tissue microarrays containing normal thyroid tissue, follicular adenoma, follicular carcinoma, papillary thyroid carcinoma, and anaplastic carcinoma were analyzed. We found that the level of GASP-1 expression can differentiate follicular adenoma from follicular carcinoma. When numerous cases were scored for GASP-1 expression by a board-certified pathologist, we found that GASP-1 expression is 7-fold higher in thyroid malignant neoplasms compared to normal thyroid tissue, and about 4-fold higher in follicular carcinoma compared to follicular adenoma. In follicular adenoma tissues, we observed the presence of many mini-glands that are enriched in GASP-1 and some mini-glands contain as few as three cells. GASP-1 IHC also possesses several advantages over the conventional H&E and can be used to identify early thyroid cancer and monitor cancer progression.

Purification and cloning of a Delta class glutathione S-transferase displaying high peroxidase activity isolated from the German cockroach Blattella germanica.

A highly active glutathione S-transferase was purified from adult German cockroaches, Blattella germanica. The purified enzyme appeared as a single band of 24 kDa by SDS/PAGE, and had a different electrophoretic mobility than, a previously identified Sigma class glutathione S-transferase (Bla g 5). Kinetic study of 1-chloro-2,4-dinitrobenzene conjugation revealed a high catalytic rate but common substrate-binding and cosubstrate-binding affinities, with V(max), k(cat), K(m) for 1-chloro-2,4-dinitrobenzene and K(m) for glutathione estimated to be 664 micromol x mg(-1) x min(-1), 545 s(-1), 0.33 mm and 0.76 mm, respectively. Interestingly, this enzyme possessed the highest activity for cumene hydroperoxide among insect glutathione S-transferases reported to date. Along with the ability to metabolize 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane and 4-hydroxynonenal, this glutathione S-transferase may play a role in defense against insecticides as well as oxidative stress. On the basis of the amino acid sequences obtained from Edman degradation and MS analyses, a 987-nucleotide cDNA clone encoding a glutathione S-transferase (BggstD1) was isolated. The longest ORF encoded a 24 614 Da protein consisting of 216 amino acid residues. The sequence had close similarities ( approximately 45-60%) to that of Delta class glutathione S-transferases, but had only 14% identity to Bla g 5. The putative amino acid sequence contained matching peptide fragments of the purified glutathione S-transferase. ELISA showed that BgGSTD1 bound to serum IgE obtained from patients with cockroach allergy, indicating that the protein may be a cockroach allergen.

Cytotoxicity of a Quinone-containing Cockroach Sex Pheromone in Human Lung Adenocarcinoma Cells.

The cytotoxic effects of blattellaquinone (BTQ), a sex pheromone produced by adult female German cockroaches, have been studied using human lung adenocarcinoma A549 cells. 1,4-Benzoquinone (BQ), a toxic chemical implicated in benzene toxicity, was used as a reference compound. Both BQ and BTQ showed comparable toxicity toward A549 cells, with LD50 values estimated to be 14 and 19 microM, respectively. These two compounds increased the formation of an oxidized fluorescent probe, 2',7'-dichlorofluorescein, but had no effect on the cellular GSSG level. Interestingly, BTQ increased the level of 8-epi-prostaglandin F2alpha and was 4-fold more efficient in depleting cellular GSH content than BQ. Of the five GSH adducts of BTQ isolated, three were identified as mono-GSH conjugates, and the other two were di-conjugates. Mass spectrometric and NMR analyses of the di-conjugates showed that the second GSH molecule displaced the isovaleric acid moiety, potentially via a nucleophilic substitution reaction. The ability of BTQ to conjugate a second GSH molecule without quinone regeneration indicated that it may be a more effective cross-linking agent than BQ. Future experiments may be needed to evaluate the overall safety of BTQ before the commercialization of the compound as a cockroach attractant.