Enzymatic activity of type 1 iodothyronine deiodinase in selected liver tumors

Development of a new thiol-reactive prosthetic group for site-specific labeling of biomolecules with radioactive iodine

In this report, we describe the radiosynthesis of a new thiol-targeting prosthetic group for efficient radioactive iodine labeling of biomolecules. Radioiodination using the precursor 3 was performed to obtain ¹²⁵I-labeled tetrazole 4b with high radiochemical yield (73%) and radiochemical purity. Using the radiolabeled 4b, a single free cysteine containing peptide and human serum albumin were labeled with ¹²⁵I in modest-to-good radiochemical yields (65-99%) under mildly reactive conditions. A biodistribution study of [¹²⁵I]7 in normal ICR mice exhibited lower thyroid uptake values than those of ¹²⁵I-labeled human serum albumin prepared via a traditional radiolabeling method. Thus, [¹²⁵I]7 could be employed as an effective radiotracer for molecular imaging and biodistribution studies. The results clearly demonstrate that 4b has the potential to be effectively implemented as a prosthetic group in the preparation of radiolabeled biomolecules.

Role of thyroid hormones in the neoplastic process: an overview

Thyroid hormones (TH) are critical regulators of several physiological processes, which include development, differentiation and growth in virtually all tissues. In past decades, several studies have shown that changes in TH levels caused by thyroid dysfunction, disruption of deiodinases and/or thyroid hormone receptor (TR) expression in tumor cells, influence cell proliferation, differentiation, survival and invasion in a variety of neoplasms in a cell type-specific manner. The function of THs and TRs in neoplastic cell proliferation involves complex mechanisms that seem to be cell specific, exerting effects via genomic and nongenomic pathways, repressing or stimulating transcription factors, influencing angiogenesis and promoting invasiveness. Taken together, these observations indicate an important role of TH status in the pathogenesis and/or development of human neoplasia. Here, we aim to present an updated and comprehensive picture of the accumulated knowledge and the current understanding of the potential role of TH status on the different hallmarks of the neoplastic process.

Contribution of mammalian selenocysteine-containing proteins to carcinogenesis

Oxidative stress caused by a sharp growth of free radicals in the organism is a major cause underlying the occurrence of all kinds of malignant formations. Selenium is an important essential trace element found in selenoproteins in the form of selenocysteine, an amino acid differing from cysteine for the presence of selenium instead of sulfur and making such proteins highly active. To date the role of selenium has been extensively investigated through studying the functions of selenoproteins in carcinogenesis. Analysis of the obtained results clearly demonstrates that selenoproteins can act as oncosuppressors, but can also, on the contrary, favor the formation of malignant tumors.

Prognostic significance of cyclooxygenase-2 expression in patients with hepatocellular carcinoma: a meta-analysis

INTRODUCTION

Cyclooxygenase-2 (COX-2) is believed to be an important enzyme in the carcinogenesis of hepatocellular carcinoma (HCC). However, it is still controversial whether COX-2 expression can be regarded as a prognostic factor for HCC patients. We performed a systematic review and meta-analysis of studies assessing the clinical and prognostic significance of COX-2 expression in HCC.

MATERIAL AND METHODS

Identification and review of publications assessing clinical or prognostic significance of COX-2 expression in HCC until November 1, 2014. A meta-analysis was performed to clarify the association between COX-2 expression and clinical outcomes.

RESULTS

A total of 11 publications met the criteria and included 943 cases. Analysis of these data showed that COX-2 expression was not significantly correlated with capsular formation (OR = 0.84, 95% confidence interval (CI): 0.46-1.55, p = 0.58), tumor TNM stage (OR = 0.73, 95% CI: 0.23-2.33, p = 0.59), vascular invasion (OR = 1.04, 95% CI: 0.25-4.35, p = 0.96), tumor size (OR = 0.78, 95% CI: 0.21-2.86, p = 0.71), or tumor differentiation degree (OR = 1.08, 95% CI: 0.42-2.79, p = 0.87). However, in the identified studies, COX-2 expression was strongly associated with high alpha-fetoprotein level (OR = 1.83, 95% CI: 1.01-3.33, p = 0.05), HBsAg status (OR = 1.85, 95% CI: 1.13-3.03, p = 0.01), decreased overall survival (relative risk (RR): 1.54, 95% CI: 1.18-2.02, p = 0.001) and decreased disease-free survival (RR = 1.49, 95% CI: 1.22-1.81, p < 0.001).

CONCLUSIONS

This meta-analysis shows that COX-2 expression in HCC is associated with decreased overall and disease-free survival and thus marks a worse prognosis. Nevertheless, more large sample and well-designed studies are warranted to confirm this finding.