Supplementary Materialsviruses-12-00042-s001. of papillomavirus oncogene transcripts assay (APOT) and mRNA mapping, and manifestation of viral oncogenes Fenofibric acid was performed by qPCR. The methylation of E2BSs was significantly higher in tumors with an integrated, in comparison to extrachromosomal, form of the viral genome. No mutations were detected in the E2BSs. The viral oncogenes were equally expressed in samples with an integrated and extrachromosomal form of the virus. Only the Fenofibric acid nucleotide variants were identified in the E2 gene. No proposed mechanism of E2 inactivation was confirmed in tonsillar tumors with an extrachromosomal form of the HPV genome. The expression of E6/E7 genes seems to be sufficient to initiate and maintain the carcinogenic process = 0.034 for E2BS2-4 area and = 0.028 for E2BS1) (Figure 2). In our group of samples, we have noticed a much higher methylation level at repressive E2BS2-4 sites compared to E2BS1 regardless of the viral genome status. Open in a separate window Figure 1 CpG nucleotide positions in the HPV16 long control region (LCR), as compared with the HPV16 reference sequence (GenBank: “type”:”entrez-nucleotide”,”attrs”:”text”:”K02718.1″,”term_id”:”333031″K02718.1). Open in a separate window Figure 2 CpG methylation levels of activating E2BS1 and repressive E2BS2-4. Numbers of methylated sequences were compared between samples with extrachromosomal/mixed or integrated viral genomes both for activating E2BS1 and repressive E2BS2-4. The difference was statistically significant for both areas (= 0.028 for E2BS1 and = 0.034 for E2BS2-4). Table 2 Methylation analysis results. Numbers of methylated (M) and unmethylated (U) sequences for each CpG of different E2BSs. Samples are divided according to their HPV genome status into extrachromosomal, mixed and integrated. Excluded from analysis were sequences of samples Fenofibric acid ORL187 (CpG 7452 and 7460) and ORL125 (CpG 7859, 37, 43, 52 and 58) due to low number of sequences analyzed (<200 sequences). = 0.075) difference between samples with the extrachromosomal/mixed and integrated Rabbit Polyclonal to GNG5 form of the genome (range 2 10?2 to 183, average copy number 49 per cell and median 16.84; range 2 10?1 to 23, average copy number five per cell, and median 0.65, respectively) (Figure 3). Furthermore, we observed no correlation between the viral fill and methylation level in the repressive E2BS2-4 area (Spearman rank relationship, = 0.400, = 0.750 for integrated genome examples and = 0.175, = 0.588 for extrachromosomal/mixed genome examples). Open in a separate window Figure 3 HPV16 viral load evaluation. Comparison of E6 gene copy numbers relative to RNase P copy number in tumors with extrachromosomal/mixed and integrated form of the viral genome. The difference was not statistically significant (= 0.075). 3.4. Quantification of Viral E6/E7 Oncogene Transcripts The more abundant of the two HPV16 transcripts was the E6*I, while the E6/7 FL transcript showed a lower expression level (Figure 4). The transcription level of the two oncogene transcripts did not differ significantly between the samples with the integrated and extrachromosomal/mixed form of the viral genome (= 0.208 for E6*I mRNA, and = 0.959 for E6/7 FL mRNA, respectively). We further evaluated if there was a correlation between the mRNA expression of the E6*I transcript and Fenofibric acid viral load, both in samples with the extrachromosomal/mixed and integrated viral genome. No correlation was observed for either extrachromosomal/mixed genome samples or integrated genome samples (= ?0.258, = 0.394; = 0.3, = 0.683, respectively). Open in a separate window Figure 4 E6/7 oncogene transcription levels. Number of spliced E6 transcripts (E6*I, a) and full length E6 transcripts (E6 FL, b) in samples with extrachromosomal/mixed and integrated HPV16 genomes normalized to HPRT mRNA. The difference is not statistically significant (= 0.208 for E6*I and = 0.959 for E6 FL). To verify the results of previous studies, the effect of the methylation status on viral transcription was also investigated. Again, there was no correlation between the average percentage of the methylated sequences of repressive E2BS2-4 and E6*I mRNA levels for the two groups of samples with different forms of the viral genome (Spearman rank correlation, = 0.077, = 0.817 for extrachromosomal/mixed genome samples and = ?0.6, = 0.417 for integrated genome samples). 3.5. E2 and LCR Variations Evaluation Viral LCR of 18 examples was sequenced to detect mutations in E2BSs. Except for test ORL 104, which fits using the D lineage variant, all examples belonged to probably the most common A variant lineage. In these A variant examples, 11 different sequences variants had been detected, but non-e of these was localized in the E2BSs. Probably the most abundant polymorphism was the G to A changeover at placement 7518, recognized in 13/17 examples, and related to a YY1 transcription element binding site (Desk 3). We examined the E6*I mRNA level in examples with sequences variant at placement 7518 (= 13) and the ones with a crazy type nucleotide (= 4), and discovered no variations in transcription.