Publication Date:
2018-11-29
Description:
Background Monoclonal gammopathy of undetermined significance (MGUS) is an asymptomatic condition arising from clonal plasma cells and has the risk of transformation to multiple myeloma (MM). Dysregulated expression of microRNAs (miRs) has been well demonstrated in MM, but miRs are not as well characterized in MGUS. We previously found an increased risk for MGUS in Vietnam veterans exposed to Agent Orange and its contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Here we report the effect of age on serum levels of 13 miRs in MGUS cases and controls from that study cohort. Methods The study base population comprised 958 US veterans who participated in the 2002 follow-up of the Air Force Health Study (AFHS). A total of 49 MGUS cases were identified by using their serum stored at the AFHS 2002 follow-up (Landgren O et al. JAMA Oncology, 2015). The current study included 47 MGUS cases and 85 controls. The controls were selected from the veterans who did not have MGUS, did not have a history of tumors, and whose TCDD level was below the third quartile value among the study base. Quantitative real-time PCR (qPCR) was used to determine the serum levels of 13 miRs (let-7a, let-7i, miR-16, miR-20a, miR-21, miR-34a, miR-106b, miR-146a, miR-181a, miR-192, miR-205, miR-335 and miR-361) that were previously shown to be dysregulated in MM or other cancers . The cycle threshold (Ct) values obtained from qPCR were normalized by using spiked-in cel-miR-39 as a control. Univariate rank regression was used to examine the relationships between relative expression of each miR and age, and each miR and MGUS status (MGUS vs control); each miR-MGUS relation was also examined with adjustment for age. All miR values were analyzed in log2 units. Continuously distributed age was summarized by the median and interquartile range (IQR): age variation with MGUS status was assessed with Kruskal-Wallis test. All statistical testing was two-sided with a significance level of p
Print ISSN:
0006-4971
Electronic ISSN:
1528-0020
Topics:
Biology
,
Medicine
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