Kinetics and persistence of cellular and humoral immune responses to SARS-CoV-2 vaccine in healthcare workers with or without prior COVID-19.

SARS-CoV-2 vaccines are highly efficient against severe forms of the disease, hospitalization and death. Nevertheless, insufficient protection against several circulating viral variants might suggest waning immunity and the need for an additional vaccine dose. We conducted a longitudinal study on the kinetics and persistence of immune responses in healthcare workers vaccinated with two doses of BNT162b2 mRNA vaccine with or without prior SARS-CoV-2 infection. No new infections were diagnosed during follow-up. At 6 months, post-vaccination or post-infection, despite a downward trend in the level of anti-S IgG antibodies, the neutralizing activity does not decrease significantly, remaining higher than 75% (85.14% for subjects with natural infection, 88.82% for vaccinated after prior infection and 78.37% for vaccinated only). In a live-virus neutralization assay, the highest neutralization titres were present at baseline and at 6 months follow-up in persons vaccinated after prior infection. Anti-S IgA levels showed a significant descending trend in vaccinated subjects (p < 0.05) after 14 weeks. Cellular immune responses are present even in vaccinated participants with declining antibody levels (index ratio 1.1-3) or low neutralizing activity (30%-40%) at 6 months, although with lower T-cell stimulation index (p = 0.046) and IFN-γ secretion (p = 0.0007) compared to those with preserved humoral responses.

The association between lncRNA H19 and EZH2 expression in patients with EBV-positive laryngeal carcinoma.

OBJECTIVE: Laryngeal cancer is the second most common malignancy in the head and neck, with Epstein-Barr virus infection as a risk factor. Our aim is to evaluate correlations between the expression of lncRNA H19 and EBV infection in laryngeal cancer and H19 involvement in neoplastic progression through EZH2 association. MATERIALS AND METHODS: 30 paired laryngeal tissue specimens (neoplastic and non-neoplastic) were included in the study. Nucleic acid isolation and cDNA synthesis was performed according to the manufacturer's protocol. EBV DNA and expression of lytic (BZLF1) and latent (LMP1) forms of infection were assessed in PCR assays; expression levels of H19 and EZH2 were quantified in qRT-PCR. Data was analysed using GraphPad Prism 5.0. RESULTS: Higher H19 relative expression in neoplastic vs paired non-neoplastic samples was found (p < 0.0001) with a significant increase in EBV DNA positive neoplasms (p = 0.0434). An inverse correlation between H19 and EZH2 expression levels was noticed in EBV positive cases. Additionally, increased levels of H19 in LMP1 positive samples compared with those positive for BZLF1 was found (p = 0.0593). CONCLUSIONS: lncRNA H19 and EZH2 significantly contribute to the development of laryngeal carcinoma, being correlated with EBV infection markers.

Alterations of regulatory factors and DNA methylation pattern in thyroid cancer.

PURPOSE: DNA methylation plays an important role in thyroid oncogenesis. The aim of this study was to investigate the connection between global and local DNA methylation status and to establish the levels of important DNA methylation regulators (TET family and DNMT1) in thyroid tumours: follicular adenoma-FA, papillary thyroid carcinoma-PTC (classic papillary thyroid carcinoma-cPTC and papillary thyroid carcinoma follicular variant fvPTC). METHODS: Global DNA methylation profile in thyroid tumours tissue (41 paired samples) was assessed by 5-methylcytosine and 5-hydroxymethylcytosine levels evaluation (ELISA), along with TETs and DNMT1 genes expression quantification. Also, it was investigated for the first time TET1 and TET2 promoter's methylation in thyroid tumours. BRAF V600E mutation and RET/PTC translocation testing were performed on all investigated samples. In vitro studies upon DNA methylation in K1 thyroid cancer cells were performed with demethylating agents (5-AzaC and vitamin C). RESULTS: TET1 and TET2 displayed a significantly reduced gene expression level in PTC, while DNMT1 gene presented a high level of expression. PTC samples presented increased levels of 5-methylcytosine and low levels of 5-hydroxymethylcytosine. 5-methylcytosine levels were associated with TET1/TET2 expression levels. TET1 gene expression was significantly lower in patients positive for BRAF mutation and with RET/PTC rearrangement. TET2 gene was found hypermethylated in thyroid carcinoma patients overall, especially in PTC-follicular variant samples (p= 0.0002), where TET2 gene expression levels were significantly reduced (p= 0.0031). Furthermore, the data indicate for all thyroid cancer patients a good sensitivity (81.08%) and specificity (86.49%) regarding the use of TET1 (p< 0.0001), and TET2 (71.79%, 64.10%, p= 0.0001) hypermethylation as biomarkers for thyroid oncogenesis. CONCLUSIONS: These results suggest that TET1/TET2 gene expression and methylation may serve as potential diagnostic tools for thyroid neoplasia. Our study showed that the methylation of TET1 increases in malignant thyroid tumours. fvPTC patients presented lower methylation levels compared to cPTC and could be a discriminatory factor between two cancer types and benign lesions. TET2 is a poorer discriminator between FA and fvPTC, but it can be useful for cPTC identification. K1-cells treated with demethylating agents showed a demethylation effect, especially upon TET2 gene. The cumulative effect of L-AA and 5-AzaC proved to have a potent combined demethylating effect on genes promoter's activation and could open new perspectives for thyroid cancer therapy.

Methylation of tumour suppressor genes associated with thyroid cancer.

BACKGROUND: Thyroid carcinoma is the most common endocrine malignancy worldwide. Changes in DNA methylation can cause silencing of normally active genes, especially tumour suppressor genes (TSG) or activation of normally silent genes. OBJECTIVE: The aim of this study is to evaluate the degree of promoter methylation for a panel of markers for thyroid neoplasms and to establish their relationship with thyroid oncogenesis. METHODS: To generate a comprehensive DNA methylation signature of TSGs involved in thyroid neoplasia, we use Human TSG EpiTect Methyl II Signature PCR Array-Qiagen for 24 samples (follicular adenomas and papillary thyroid carcinomas) compared with normal thyroid tissue. We extended the evaluation for three TSGs (TP73, WIF1, PDLIM4) using qMS-PCR. Statistical analysis was performed with GraphPad Prism. RESULTS: We noted four important genes NEUROG1, ESR1, RUNX3, MLH1, which presented methylated promoter in tumour samples compared to normal. We found new characteristic of thyroid tumours: methylation of TP73, WIF1 and PDLIM4 TSGs, which can contribute to thyroid neoplasia. A significant correlation between BRAF V600E mutation and RET/PTC rearrangements with TIMP3 and CDH13, RARB methylation, respectively was observed. CONCLUSIONS: TSGs promoter hypermethylation is a hallmark of cancer and a test that uses methylation quantification method is suitable for diagnosis and prognosis of thyroid cancer.

Comparative molecular approaches in Prader-Willi syndrome diagnosis.

Prader-Willi and Angelman syndromes are two distinct neurogenetic disorders caused by chromosomal deletions, uniparental disomy or loss of the imprinted gene expression in the 15q11-q13 region. PWS results from the lack of the paternally expressed gene contribution in the region. The aim of our study was to compare a new molecular approach based on the quantification of the expression of non-imprinted bi-allelic gene (NIPA1 and OCA2) with in house MS-PCR and the MS-MLPA test. Blood samples were collected from 12 patients, clinical criteria positives for Prader-Willi syndrome. DNA and RNA samples were isolated from white blood cells. Epigenetic changes at SNRPN gene locus were evaluated by MS-PCR technique. The expression levels of two non-imprinted genes (NIPA1 and OCA2) were evaluated in qReal-Time PCR, in order to identify type 1 and type 2 deletions. SALSA MS-MLPA kit ME028 was used to detect copy number changes and to analyze CpG islands methylation of the 15q11 region. MS-MLPA test confirmed that 8/12 patients presented different types of deletion at the SNRPN gene level (promoter, introns, and exons) and 4/8 displayed type 1 or type 2 deletion. In children with 15q11-13 deletions, the decreased level of NIPA1and OCA2 gene expression is related to chromosomal abnormality in the investigated area. The deletions were confirmed by MS-MLPA analysis, thus recommending NIPA1 and OCA2 gene expression as an alternate method to investigate deletions.

E5HPV16 mRNA EXPRESSION PATTERN ANALYSIS IN PATIENTS WITH CERVICAL LESIONS IN VIRAL STATUS CONTEXT.

Human papilloma virus (HPV) may cause mostly transient infections of cutaneous and mucous epithelia. Persistent HPV genital infections may induce pre-malignant or malignant lesions. While E6 and E7 HPV genes' malignant character is known, E5 is still under debate. We evaluated the possible role of E5 gene in cervix oncogenesis, in patients with abnormal cytology and HPV1 6 positive, in the context of viral status correlated with potential targets (p21, EGFR). HPV DNA was detected and genotyped using Linear Array HPV Genotyping Test (Roche Molecular Biochemicals, Mannheim, Germany) and E2, E6, E5 HPV16, p21 and EGFR transcripts levels were investigated by qRT-PCR. Our results indicate a significantly high E5 expression in low grade cytology, expression correlated with a moderated E6 and low p21 levels. All HSIL specimens presented integrated/mixed viral forms; mixed forms presented moderate E5 expression, high levels of p21 correlates with E6 oncogene high expression. These findings indicate a potential role for E5 pattern of expression in discriminating be-tween lesions that may progress to cancer.

Molecular variants of human papilloma virus 16 E2, E4, E5, E6 and E7 genes associated with cervical neoplasia in Romanian patients.

The aim of this study was to identify and associate the sequence variations of human Papillomavirus 16 (HPV16) genes from women who live in two different areas of Romania and associate them with malignant progression. One hundred twenty-four HPV16-positive cervical isolates were collected, and the E2, E4, E5, E6 and E7 viral genes were sequenced. Two new missense mutations in the E6 gene (C279G and A305C) were found (together or alone, in association with other mutations) in 44 of 124 cases. The most frequently simultaneously mutated genes were E4/E2 hinge, E5 and E6 (p = 0.0004) in squamous cell carcinoma (SCC) samples. Also, for SCC patients, the best-correlated mutation patterns were obtained for E4/E2 hinge-E5 (r = 0.7984; p < 0.0001). No sample was found to have all of the investigated viral genes concurrently mutated. Phylogenetic analysis was performed to characterize the viral variants. Similar results were found for SCC and cervical intraepithelial neoplasia III (CINIII) cases. After all of the target gene sequences were assembled, all patients were found to be infected with viruses of the HPV16- European-German (EG) lineage, and two clusters were identified, the first (55/96 variants) from Moldavia and the second (41/96 variants) from Bucharest. The distinct cluster derived from EG in Moldavia could partially explain the increased frequency of SCC in this area. This study has generated a comprehensive set of sequence variation data on HPV16 circulating in Romania to join the existing data and highlight the important role of HPV16 variants during cervical carcinogenesis.

Methylenetetrahydrofolate reductase (MTHFR) polymorphisms and promoter methylation in cervical oncogenic lesions and cancer.

The aim of this study was to investigate the role of methylenetetrahydrofolate reductase (MTHFR) polymorphisms and MTHFR methylation pattern in cervical lesions development among women from Romania, a country with high prevalence of human papillomavirus (HPV) cervical infections. To achieve this goal, blood samples and cervical cytology specimens (n = 77)/tumour tissue specimens (n = 23) were investigated. As control, blood and negative cytological smears (n = 50) were used. A statistically significant association was found between T allele of C677T polymorphism and cervical lesions, heterozygote women presenting a threefold increased risk (normal/cervical lesions and tumours: wild homozygote 34/41 (0.68/0.41), heterozygote 14/51 (0.28/0.51), mutant homozygote 2/8 (0.04/0.08); OR = 3.081, P = 0.0035). Using χ square test for the control group, the HPV-negative and HPV-positive patients with cervix lesions, a significant correlation between viral infection and T allele of C677T polymorphism (P = 0.0287) was found. The MTHFR promoter was methylated in all HGSIL and tumour samples, significant differences being noted between HPV-positive samples, control group and cases of cervical dysplastic lesions without HPV DNA (P < 0. 0001) and between samples from patients with high-risk (hr)HPV versus low-risk (lr)HPV (P = 0.0026). No correlations between polymorphisms and methylation were observed. In Romania, individuals carrying T allele are susceptible for cervical lesions. MTHFR promoter methylation is associated with cervical severity lesions and with hrHPV.

Mitochondrial DNA mutations in patients with HRHPV-related cervical lesions.

High risk human papillomaviruses (hr-HPV) are known to be the etiological agents of cervical cancer disease. On the other hand, other cofactors are considered to be important in cervix carcinogenesis. Mutations in mitochondrial DNA (mtDNA) as well as alterations in mtDNA content have been reported in numerous cancers examined to date. The D-loop region has been shown to be a mutational "hot spot" in human cancer. In order to evaluate the role of mtDNA mutations in cervical lesions progression, cervical specimens (from 79 women, 29-65 years old) were investigated. DNA was isolated (High Pure PCR Template, Roche Diagnostics) from cervical cells from patients with different cytology (normal cervical epithelium, ASCUS-Atypical Squamous Cells of Undetermined Significance, LGSIL-Low-Grade Intraepithelial Lesion, HGSIL-High-Grade Intraepithelial Lesion and SCC-Squamous Cell Carcinoma) and tested for HPV DNA presence (Linear Array HPV Genotyping Test, Roche Diagnostics). To elucidate a causative role of mtDNA in cervical lesions, mtDNA mutations were investigated using Mutector mtDNA kit (TrimGen Corporation). In patients with normal and ASCUS cytology, mtDNA mutations were absent. 16.66% of LGSIL patients presented mutations in D-loop region whereas 28.57% HGSIL cases showed mutations in mtDNA. Mutations were detected in 66.66% cases of SCC cases. These studies provide strong evidence that instability in the D-loop region of mtDNA may be involved in cervical dysplasia. We suggested that mtDNA mutations may play a role in cervical precursor lesions and cancer but their role in the mechanism of carcinogenesis remains to be solved.