ABSTRACT
BACKGROUND/AIM: Malignant pleural mesothelioma (MPM) is an intractable cancer, and causes of its malignant transformation are not well known. Adenosine deaminase acting on RNA (ADAR) is an RNA-editing enzyme that converts adenosine into inosine in double-stranded RNAs potentially involved in malignant development. MATERIALS AND METHODS: To examine the role of ADAR1 and ADAR2 in MPM, small interfering RNAs (siRNAs) against ADAR1 or ADAR2 were used. RESULTS: Transfection of siRNA against ADAR2 suppressed proliferation, motility, and invasiveness of MPM cells expressing both ADAR1 and ADAR2; however, siRNA against ADAR1 did not affect these cellular activities. Overexpression of ADAR2, that was incapable of binding to RNA, suppressed growth, motility, and invasion of MPM cells. However, overexpression of ADAR2 that had no enzyme activity did not alter the malignant properties of MPM cells. CONCLUSION: Enhancement of the malignant characteristics of cultured MPM cells via ADAR2 was independent of RNA-editing activity.
Subject(s)
Adenosine Deaminase/metabolism , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Mesothelioma/genetics , Mesothelioma/metabolism , RNA Editing , RNA-Binding Proteins/metabolism , Adenosine Deaminase/biosynthesis , Adenosine Deaminase/genetics , Cell Line, Tumor , Cell Movement/physiology , Cell Proliferation/physiology , Humans , Lung Neoplasms/enzymology , Lung Neoplasms/pathology , Mesothelioma/enzymology , Mesothelioma/pathology , Mesothelioma, Malignant , RNA, Small Interfering/administration & dosage , RNA, Small Interfering/genetics , RNA-Binding Proteins/biosynthesis , RNA-Binding Proteins/genetics , TransfectionABSTRACT
BACKGROUND: The unmet medical needs of individuals with very rare diseases are high. The clinical trial designs and evaluation methods used for 'regular' drugs are not applicable in the clinical development of ultra-orphan drugs (<1000 patients) in many cases. In order to improve the clinical development of ultra-orphan drugs, we examined several points regarding the efficient evaluations of drug efficacy and safety that could be conducted even with very small sample sizes, based on the review reports of orphan drugs approved in Japan. RESULTS: The clinical data packages of 43 ultra-orphan drugs approved in Japan from January 2001 to December 2014 were investigated. Japanese clinical trial data were not included in the clinical data package for eight ultra-orphan drugs, and non-Japanese clinical trial data were included for six of these eight drug. Japanese supportive data that included retrospective studies, published literature, clinical research and Japanese survey results were clinical data package attachments in 22 of the 43 ultra-orphan drugs. Multinational trials were conducted for three ultra-orphan drugs. More than two randomized controlled trials (RCTs) were conducted for only 11 of the 43 ultra-orphan drugs. The smaller the number of patients, the greater the proportion of forced titration and optional titration trials were conducted. Extension trials were carried out for enzyme preparations and monoclonal antibodies with high ratio. Post-marketing surveillance of all patients was required in 36 of the 43 ultra-orphan drugs. For ultra-orphan drugs, clinical endpoints were used as the primary efficacy endpoint of the pivotal trial only for two drugs. The control groups in RCTs were classified as follows: placebo groups different dosage groups, and active controls groups. Sample sizes have been determined on the basis of feasibility for some ultra-orphan drugs. We provide "Draft Guidance on the Clinical Development of Ultra-Orphan Drugs" based on this research. CONCLUSIONS: The development of ultra-orphan drugs requires various arrangements regarding evidence collection, data sources and the clinical trial design. We expect that this draft guidance is useful for ultra-orphan drugs developments in future.
Subject(s)
Orphan Drug Production/methods , Humans , Japan , Rare Diseases/drug therapy , Retrospective StudiesABSTRACT
The mechanism of action on biomolecules of N2 gas plasma, a novel sterilization technique, remains unclear. Here, the effect of N2 gas plasma on protein structure was investigated. BSA, which was used as the model protein, was exposed to N2 gas plasma generated by short-time high voltage pulses from a static induction thyristor power supply. N2 gas plasma-treated BSA at 1.5 kilo pulses per second showed evidence of degradation and modification when assessed by Coomassie brilliant blue staining and ultraviolet spectroscopy at 280 nm. Fourier transform infrared spectroscopy analysis was used to determine the protein's secondary structure. When the amide I region was analyzed in the infrared spectra according to curve fitting and Fourier self-deconvolution, N2 gas plasma-treated BSA showed increased α-helix and decreased ß-turn content. Because heating decreased α-helix and increased ß-sheet content, the structural changes induced by N2 gas plasma-treatment of BSA were not caused by high temperatures. Thus, the present results suggest that conformational changes induced by N2 gas plasma are mediated by mechanisms distinct from heat denaturation.
