The Expression of hsp-miRNA-200b-3p and -200c-3p in Human Cytomegalovirus-infected Formalin-Fixed, Paraffin-Embedded Tissues

BACKGROUND: Human cytomegalovirus (HCMV), which exist as asymptomatic latent status, can cause the tissue invasive disease through reactivation in various immunocompromised conditions. Hsp-microRNA has a specific function of post transcriptional suppression through binding with 3’ untranslated region (UTR) of mRNA. In previous study, hsp-miR-200b-3p and -200c-3p had high probability of conjugation with 3’UTR of mRNA encoded by HCMV UL 122–123 region, which translate the immediate early protein 2 (IE2) protein. IE2 (pp86) plays an essential role to initiate and regulate viral early (E) gene activation as well as propagate the subsequent steps of HCMV lytic replication. This study was aimed to evaluate whether HCMV-infected tissue had a lower expression level of hsp-miR-200b-3p and -200c-3p. METHODS: We had collected the formalin-fixed, paraffin-embedded tissues (FFPEs) with cytopathic pathologic findings as well as positive immunohistochemical stain (IHC) test for HCMV (N = 111). The HCMV-uninfected normal tissues (N = 77) were selected among FFPEs with neither infection nor inflammation as well as negative HCMV IHC test. We performed TaqMan(®) MicroRNA real-time RT-PCR to measure the expression levels of hsp-miR-200b-3p and -200c-3p and TaqMan(®) real-time PCR for HCMV UL83 region to measure HCMV viral load in each FFPE. We utilized the standard curves consisting of mirVana(TM) miRNA mimics corresponding to each of two miRNAs, ranging from 10(6) to 10(1) copies/µL and HCMV NIBSC 09/162 strain, ranging from 5 X 10(6) to 5 X 10(1) IU/mL. RESULTS: The levels of hsp-miR-200b-3p and -200c-3p were strongly correlated with r=0.844 (P < 0.001). The expressions levels of hsp-miR-200b-3p in HCMV-infected FFPEs (log(10) 3.50 ± 0.13 copies/µL) were significantly lower than normal tissues (log(10) 5.24 ± 0.12 copies/µL of input RNA, P < 0.001). Also, HCMV-infected FFPEs were significantly lower levels of hsp-miR-200c-3p compared than normal tissues (log(10) 5.28 ± 0.18 vs. 7.81 ± 0.11 copies/µL of input RNA, P = 0.025). The levels of miR-200b-3p and -200c-3p had the significant inverse correlation with HCMV VL (200b-3p, spearman r=-0.392, P < 0.001 and 200c-3p, spearman r=-0.355, P < 0.001). CONCLUSION: The low expression of hsp-miRNA-200b-3p and -200c-3p could play a pathophysiologic role of development of HCMV tissue-invasive disease. DISCLOSURES: All authors: No reported disclosures.