A panel of KSHV mutants in the polycistronic kaposin locus for precise analysis of individual protein products

Investigation of key miRNAs and Target-mRNA in Kaposi's sarcoma using bioinformatic methods

Kaposi's sarcoma (KS) is the second most common tumor in human immunodeficiency virus (HIV) infected patients worldwide. While many miRNAs have been confirmed to be involved in KS biological processes, no relevant studies have combined miRNA and mRNA expression profiles using KS patient tissue biopsies. In this study, we performed transcriptome sequencing on tumor and normal tissues from four KS patients and identified differentially expressed mRNA and miRNA, further performed target gene prediction and enrichment analysis. 19,551 target-mRNAs were identified by predicting 106 miRNAs, with 553 overlapping with 571 significantly differentially expressed mRNAs. Enrichment analysis showed significant involvement of the Ubiquitin-mediated proteolysis pathway. Additionally, the miRNA-mRNA interaction network was established, and the topological score of Cytohubba's algorithm was calculated for comparison with three other datasets. The Mutual Clustering Coefficient (MCC) scoring ranking placed ZBTB34, NFIB, and RORA as the top three mRNAs, while hsa-miR-16-5p, hsa-miR-27a-3p, hsa-miR-340-5p, hsa-miR-182-5p, and hsa-miR-186-5p ranked as the top five miRNAs. Hsa-miR-101-3p is the only miRNA that appears both in the top 10 MCC scores and at the intersection of the other two datasets. Finally, qRT-PCR was used to validate the findings at the cellular level. In summary, the miRNA analysis results indicated that hsa-miR-101-3p could be used as a potential diagnostic or therapeutic marker in future studies. Moreover, the mRNA analysis results suggested that the histone binding pathways involved in mRNAs and ubiquitin-related biological processes were closely associated with KS and could serve as promising biomarkers for the diagnosis and treatment of this disease.

Variation within major internal repeats of KSHV in vivo

Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of Kaposi's sarcoma (KS), yet the viral genetic factors that lead to the development of KS in KSHV-infected individuals have not been fully elucidated. Nearly, all previous analyses of KSHV genomic evolution and diversity have excluded the three major internal repeat regions: the two origins of lytic replication, internal repeats 1 and 2 (IR1 and IR2), and the latency-associated nuclear antigen (LANA) repeat domain (LANAr). These regions encode protein domains that are essential to the KSHV infection cycle but have been rarely sequenced due to their extended repetitive nature and high guanine and cytosine (GC) content. The limited data available suggest that their sequences and repeat lengths are more heterogeneous across individuals than in the remainder of the KSHV genome. To assess their diversity, the full-length IR1, IR2, and LANAr sequences, tagged with unique molecular identifiers (UMIs), were obtained by Pacific Biosciences' single-molecule real-time sequencing (SMRT-UMI) from twenty-four tumors and six matching oral swabs from sixteen adults in Uganda with advanced KS. Intra-host single-nucleotide variation involved an average of 0.16 per cent of base positions in the repeat regions compared to a nearly identical average of 0.17 per cent of base positions in the remainder of the genome. Tandem repeat unit (TRU) counts varied by only one from the intra-host consensus in a majority of individuals. Including the TRU indels, the average intra-host pairwise identity was 98.3 per cent for IR1, 99.6 per cent for IR2 and 98.9 per cent for LANAr. More individuals had mismatches and variable TRU counts in IR1 (twelve/sixteen) than in IR2 (two/sixteen). There were no open reading frames in the Kaposin coding sequence inside IR2 in at least fifty-five of ninety-six sequences. In summary, the KSHV major internal repeats, like the rest of the genome in individuals with KS, have low diversity. IR1 was the most variable among the repeats, and no intact Kaposin reading frames were present in IR2 of the majority of genomes sampled.