L1 Region Research Articles

YY1 is a transcriptional activator of the mouse LINE-1 Tf subfamily.

Long interspersed element type 1 (LINE-1, L1) is an active autonomous transposable element in human and mouse genomes. L1 transcription is controlled by an internal RNA polymerase II promoter in the 5' untranslated region (5'UTR) of a full-length L1. It has been shown that transcription factor YY1 binds to a conserved sequence at the 5' end of the human L1 5'UTR and primarily dictates where transcription initiates. Putative YY1-binding motifs have been predicted in the 5'UTRs of two distinct mouse L1 subfamilies, Tf and Gf. Using site-directed mutagenesis, in vitro binding and gene knockdown assays, we experimentally tested the role of YY1 in mouse L1 transcription. Our results indicate that Tf, but not Gf subfamily, harbors functional YY1-binding sites in 5'UTR monomers and YY1 functions as a transcriptional activator for the mouse Tf subfamily. Activation of Tf transcription by YY1 during early embryogenesis is also supported by a reanalysis of published zygotic knockdown data. Furthermore, YY1-binding motifs are solely responsible for the synergistic interaction between Tf monomers, consistent with a model wherein distant monomers act as enhancers for mouse L1 transcription. The abundance of YY1-binding sites in Tf elements also raise important implications for gene regulation across the genome.

Comparative Analysis of HPV16 Variants in the Untranslated Regulatory Region, L1, and E6 Genes among Vaccinated and Unvaccinated Young Women: Assessing Vaccine Efficacy and Viral Diversity.

HPV16 is occasionally detected in vaccinated women who received the bivalent HPV16/18 vaccine, usually at low viral loads. This study explored potential differences in HPV16 variants between vaccinated and unvaccinated women. HPV16-postive viral loads were detected in 1.9% (17/875) and 13% (162/760) of vaccinated and unvaccinated women, respectively, showcasing the vaccine's high efficacy. The L1, E6, and URR regions of HPV16 were sequenced from genital swabs from 16 vaccinated and 25 unvaccinated women in the HAVANA (HPV Among Vaccinated And Non-vaccinated Adolescents) study. The majority of HPV16 variants from vaccinated and unvaccinated women clustered similarly with sub-lineages A1 and A2. Additionally, a separate cluster within lineage A was found, with the variants sharing the L1-located SNP A753G (synonymous) and the URR-located SNP T340C, which did not occur in the other variants. Furthermore, four variants from vaccinated women had relatively long branches, but were not characterized by specific SNPs. The frequency of G712A in the URR was the only SNP observed to be marginally higher among vaccinated women than unvaccinated women. Non-synonymous SNPs T266A in the FG-loop of L1 and L83V in E6 were common among variants from vaccinated and unvaccinated women, but present in similar frequencies. In conclusion, the detection of HPV16 in vaccinated (and unvaccinated) women seemed to be the result of random circulation within this study population.

Identification of the protease inhibitory domain of Trichinella spiralis novel cystatin (TsCstN).

The Trichinella spiralis novel cystatin (TsCstN) inhibits cathepsin L (CatL) activity and inflammation of macrophages during lipopolysaccharide (LPS) induction. To identify the protease inhibitory region, this study applied an in silico modeling approach to simulate truncation sites of TsCstN (Ts01), which created four truncated forms, including TsCstN∆1-39 (Ts02), TsCstN∆1-71 (Ts03), TsCstN∆1-20, ∆73-117 (Ts04), and TsCstN∆1-20, ∆42-117 (Ts05). The superimposition of these truncates modeled with AlphaFold Colab indicated that their structures were more akin to Ts01 than those modeled with I-TASSER. Moreover, Ts04 exhibited the closest resemblance to the structure of Ts01. The recombinant Ts01 (rTs01) and truncated proteins (rTs02, rTs03, and rTs04) were successfully expressed in a prokaryotic expression system while Ts05 was synthesized, with sizes of approximately 14, 12, 8, 10, and 2.5 kDa, respectively. When determining the inhibition of CatL activity, both rTs01 and rTs04 effectively reduced CatL activity in vitro. Thus, the combination of the α1 and L1 regions may be sufficient to inhibit CatL. This study provides comprehensive insights into TsCstN, particularly regarding its protein function and inhibitory domains against CatL.

Epidemiological distribution of high-risk human papillomavirus genotypes and associated factors among patients with esophageal carcinoma at Bugando medical center in Mwanza, Tanzania

BackgroundEsophageal carcinoma is a growing concern in regions that have a high incidence of human papillomavirus (HPV) infection such as East Africa. HPV, particularly the high-risk genotypes, is increasingly recognized as a risk factor for esophageal carcinoma. We set out to investigate the prevalence and associated factors of high-risk HPV in formalin-fixed paraffin-embedded (FFPE) tissue blocks with esophageal carcinoma at Bugando Medical Center, a tertiary referral hospital in Mwanza, Tanzania, East Africa.MethodsA total of 118 esophageal carcinoma FFPE tissue blocks, collected from January 2021 to December 2022, were analyzed. Genomic DNA was extracted from these tissues, and multiplex polymerase chain reaction (PCR) was performed to detect HPV using degenerate primers for the L1 region and type-specific primers for detecting HPV16, HPV18, and other high-risk HPV genotypes. Data were collected using questionnaires and factors associated with high-risk HPV genotypes were analyzed using STATA version 15 software.ResultsOf the 118 patients’ samples investigated, the mean age was 58.3 ± 13.4 years with a range of 29–88 years. The majority of the tissue blocks were from male patients 81/118 (68.7%), and most of them were from patients residing in Mwanza region 44/118 (37.3%). Esophageal Squamous Cell Carcinoma (ESCC) was the predominant histological type 107/118 (91.0%). Almost half of the tissue blocks 63/118 (53.3%) tested positive for high-risk HPV. Among these, HPV genotype 16 (HPV16) was the most common 41/63 (65.1%), followed by HPV genotype 18 (HPV18) 15/63 (23.8%), and the rest were other high-risk HPV genotypes detected by the degenerate primers 7/63 (11.1%). The factors associated with high-risk HPV genotypes were cigarette smoking (p-value < 0.001) and alcohol consumption (p-value < 0.001).ConclusionA substantial number of esophageal carcinomas from Bugando Medical Center in Tanzania tested positive for HPV, with HPV genotype 16 being the most prevalent. This study also revealed a significant association between HPV status and cigarette smoking and alcohol consumption. These findings provide important insights into the role of high-risk HPV in esophageal carcinoma in this region.

Spinal cord nephroblastoma in a Chihuahua

AbstractA 2‐year‐old, male, neutered chihuahua was referred to the neurology service with a 3‐week history of progressive weakness of both pelvic limbs. A myelo‐computed tomography and high field magnetic resonance imaging of the thoracolumbar vertebral column identified a large, focal, intradural‐extramedullary mass in the T12–L1 region of the vertebral canal. Histopathological analysis was compatible with a spinal cord nephroblastoma. The dog was treated with toceranib, but was euthanased due to lack of improvement. To the authors’ knowledge, this is the first report of a spinal cord nephroblastoma in a chihuahua and the first report that describes the use of toceranib for this tumour type.

Regional bias in monolingual English language models

In Natural Language Processing (NLP), pre-trained language models (LLMs) are widely employed and refined for various tasks. These models have shown considerable social and geographic biases creating skewed or even unfair representations of certain groups. Research focuses on biases toward L2 (English as a second language) regions but neglects bias within L1 (first language) regions. In this work, we ask if there is regional bias within L1 regions already inherent in pre-trained LLMs and, if so, what the consequences are in terms of downstream model performance. We contribute an investigation framework specifically tailored for low-resource regions, offering a method to identify bias without imposing strict requirements for labeled datasets. Our research reveals subtle geographic variations in the word embeddings of BERT, even in cultures traditionally perceived as similar. These nuanced features, once captured, have the potential to significantly impact downstream tasks. Generally, models exhibit comparable performance on datasets that share similarities, and conversely, performance may diverge when datasets differ in their nuanced features embedded within the language. It is crucial to note that estimating model performance solely based on standard benchmark datasets may not necessarily apply to the datasets with distinct features from the benchmark datasets. Our proposed framework plays a pivotal role in identifying and addressing biases detected in word embeddings, particularly evident in low-resource regions such as New Zealand.

HPV Detection in Breast Tumors and Associated Risk Factors in Northeastern Brazil.

Breast cancer risk factors include lifestyle, genetic-hormonal influences, and viral infections. Human papillomavirus (HPV), known primarily as the etiological agent of cervical cancer, also appears active in breast carcinogenesis, as evidenced in our study of 56 patients from northeastern Brazil. We assessed the clinical and sociodemographic characteristics, correlating them with various breast cancer tumor types. HPV detection involved amplifying the L1 region, with viral load measured using the E2/E6 ratio and viral activity indicated by E5 oncogene expression. Predominantly, patients over 56 years of age with healthy lifestyles showed a high incidence of invasive ductal carcinoma and triple-negative breast cancer. HPV was detected in 35.7% of cases, mostly HPV16, which is associated with high viral loads (80 copies per cell) and significant E5 expression. These results hint at a possible link between HPV and breast carcinogenesis, necessitating further studies to explore this association and the underlying viral mechanisms.

Structural insights into instability of the nucleosome driven by histone variant H3T

The testis-specific histone variant H3T plays a crucial role in chromatin reorganization during spermatogenesis by destabilizing nucleosomes. However, the structure basis for the nucleosome instability driven by H3T is not fully understand. In this study, we determinate the crystal structure of H3T-H4 in complex with histone chaperone ASF1a at 2.8 Å resolution. Our findings reveal that H3T-H4 binds ASF1a similarly to the conventional H3.1-H4 complex. However, significant structural differences are observed in the H3 α1 helix, the N- and C-terminal region of α2, and N-terminal region of L2. These differences are driven by H3T-specific residues, particularly Val111. Unlike the smaller Ala111 in H3.1, we find that bulkier residue Val111 fits well within the ASF1-H3T-H4 complex, but is difficult to arrange in nucleosome structure. Given that H3.1-Ala111/H3T-Val111 is located at the DNA binding and tetramerization interface of H3–H4, it is likely that Ala111Val substitution will lead to the instability of the corresponding area in nucleosome, contributing to instability of H3T-containing nucleosome. These structural findings may elucidate the role of H3T in chromatin reorganization during spermatogenesis.

Differential long-term bivalent HPV vaccine cross-protection by variants in the Costa Rica HPV vaccine trial

The AS04-adjuvanted human papillomavirus (HPV)16/18 vaccine, an L1-based vaccine, provides strong vaccine efficacy (VE) against vaccine-targeted type infections, and partial cross-protection to phylogenetically-related types, which may be affected by variant-level heterogeneity. We compared VE against incident HPV31, 33, 35, and 45 detections between lineages and SNPs in the L1 region among 2846 HPV-vaccinated and 5465 HPV-unvaccinated women through 11-years of follow-up in the Costa Rica HPV Vaccine Trial. VE was lower against HPV31-lineage-B (VE=60.7%;95%CI = 23.4%,82.8%) compared to HPV31-lineage-A (VE=94.3%;95%CI = 83.7%,100.0%) (VE-ratio = 0.64;95%CI = 0.25,0.90). Differential VE was observed at several lineage-associated HPV31-L1-SNPs, including a nonsynonymous substitution at position 6372 on the FG-loop, an important neutralization domain. For HPV35, the only SNP-level difference was at position 5939 on the DE-loop, with significant VE against nucleotide-G (VE=65.0%;95%CI = 28.0,87.8) but not for more the common nucleotide-A (VE=7.4%;95%CI = −34.1,36.7). Because of the known heterogeneity in precancer/cancer risk across cross-protected HPV genotype variants by race and region, our results of differential variant-level AS04-adjuvanted HPV16/18 vaccine efficacy has global health implications.

Nucleic acid mediated activation of a short prokaryotic Argonaute immune system

A short prokaryotic Argonaute (pAgo) TIR-APAZ (SPARTA) defense system, activated by invading DNA to unleash its TIR domain for NAD(P)+ hydrolysis, was recently identified in bacteria. We report the crystal structure of SPARTA heterodimer in the absence of guide-RNA/target-ssDNA (2.66 Å) and a cryo-EM structure of the SPARTA oligomer (tetramer of heterodimers) bound to guide-RNA/target-ssDNA at nominal 3.15–3.35 Å resolution. The crystal structure provides a high-resolution view of SPARTA, revealing the APAZ domain as equivalent to the N, L1, and L2 regions of long pAgos and the MID domain containing a unique insertion (insert57). Cryo-EM structure reveals regions of the PIWI (loop10-9) and APAZ (helix αN) domains that reconfigure for nucleic-acid binding and decrypts regions/residues that reorganize to expose a positively charged pocket for higher-order assembly. The TIR domains amass in a parallel-strands arrangement for catalysis. We visualize SPARTA before and after RNA/ssDNA binding and uncover the basis of its active assembly leading to abortive infection.

Cloning, Expression, and Bioinformatics Modeling of Human Papillomavirus Type 52 L1/L2 Chimeric Protein in Escherichia coli BL21 (DE3)

Human papillomavirus (HPV) L1 major capsid protein generates a highly immunogenic virus like particles (VLPs), which have been used as the main component of its prophylactic vaccine. However, the neutralizing antibodies against L1 VLPs are mostly type specific and may not be effective to prevent infection from different strains of HPV. On the other hand, HPV L2 minor capsid protein has low antigenic variation, thus can induce cross-neutralization. This study aims to obtain HPV 52 L1/L2 chimeric protein, which is designed based on HPV type 52 as one of the most circulated high-risk types in Indonesia, to develop a broad-spectrum HPV vaccine. Substitution of HPV 52 H4 helix L1 region with an HPV 52 L2 epitope was carried out using overlap extension PCR. HPV 52 L1/L2 chimeric gene was constructed into pET-SUMO expression vector and expressed in Escherichia coli BL21 (DE3). Bioinformatics modeling suggested that L2 epitope was located inside of the loop region in monomer form, and on the contrary, it was located outside of the pentamer surface. Furthermore, B cell and T cell epitopes predictions were conducted using Immune Epitope Database (IEDB) analysis. The B cell epitopes prediction revealed eleven potential epitopes, whereas the T cell epitopes prediction showed seven potential epitopes for each MHC class I and MHC class II. This study showed that HPV 52 L1/L2 chimeric protein has the potential to induce cross-neutralizing antibodies and can be developed as a promising candidate for a new HPV vaccine.

Assessment of body composition in breast cancer patients: concordance between transverse computed tomography analysis at the fourth thoracic and third lumbar vertebrae.

Specific body composition markers derived from L3 axial computed tomography (CT) images predict clinical cancer outcomes, including chemotherapy toxicity and survival. However, this method is only applicable to those undergoing lumbar (L3) CT scanning, which is not universally conducted in early breast cancer cases. This study aimed to evaluate CT analysis at T4 as a feasible alternative marker of body composition in breast cancer. All patients participated in the Investigating Outcomes from Breast Cancer: Correlating Genetic, Immunological, and Nutritional (BeGIN) Predictors observational cohort study (REC reference number: 14/EE/1297). Staging chest-abdomen-pelvic CT scan images from 24 women diagnosed with early breast cancer at University Hospital Southampton were analysed. Adipose tissue, skeletal muscle, and muscle attenuation were measured from the transverse CT slices' cross-sectional area (CSA) at T4 and L3. Adipose tissue and skeletal muscle area measurements were adjusted for height. Spearman's rank correlation coefficient analysis was used to determine concordance between body composition measurements using CT analysis at L3 and T4 regions. Derived estimates for total adipose tissue, subcutaneous adipose tissue, and intramuscular adipose tissue mass following adjustment for height were highly concordant when determined from CSAs of CT slices at T4 and L3 (Rs = 0.821, p < 0.001; Rs = 0.816, p < 0.001; and Rs = 0.830, p < 0.001). In this cohort, visceral adipose tissue (VAT) and skeletal muscle estimates following height adjustment were less concordant when measured by CT at T4 and L3 (Rs = 0.477, p = 0.039 and Rs = 0.578, p = 0.003). The assessment of muscle attenuation was also highly concordant when measured by CT at T4 and L3 (Rs = 0.840, p < 0.001). These results suggest that the CT analysis at T4 and L3 provides highly concordant markers for total adipose, subcutaneous adipose, and intramuscular adipose estimation, but not VAT, in this breast cancer population. High concordance between T4 and L3 was also found when assessing skeletal muscle attenuation. Lower concordance was observed for the estimates of skeletal muscle area, potentially explained by differences in the quantity and proportions of axial and appendicular muscle between the thorax and abdomen. Future studies will determine the value of T4 metrics as predictive tools for clinical outcomes in breast cancer.

Molecular Prevalence of Human Papillomavirus Types 16 and 18 in Oral Squamous Cell Carcinoma using Real-time PCR.

Human papillomavirus(HPV) has been established as a causative agent in the development of oral squamous cell carcinoma (OSCC). Specifically, HPV types 16 and 18 are known to be prevalent in oral cancers. This cross-sectional study aimed to determine the prevalence of HPV types 16 and 18 in OSCC cases in Qazvin province, Iran. Thirty-eight paraffin-embedded samples of OSCC were selected, and DNA extraction was performed using the Roche High Pure FFPE DNA isolation kit. The quality of the extracted DNA was assessed through PCR amplification of the human β-Globin gene. The HPV detection was carried out using SYBR green-based real-time PCR with GP5+ and GP6+ primers targeting the L1 region of HPV. The HPV genotyping was conducted on positive samples using specific primers. Statistical analysis was performed between HPV infection in OSCC and age, sex, and anatomical location. This study analyzed 38 biopsy specimens obtained from male and female OSCC patients, with an average age of 64 years. Among these samples, 13 tested positive for HPV, resulting in a prevalence rate of 34.2%. The age group with the highest HPV infection rate was 61-70 (10.5%) years. Notably, HPV type 16 was detected in 21.0% of samples, HPV type 18 in 10.5%, and other viral subtypes in 2.6%. No statistically significant correlation was found between HPV prevalence and gender or age. The findings indicated that 34.2% of OSCC samples in the Qazvin province harbor HPV, with types 16 and 18 being the most common in tumors affecting the tongue. Additionally, no association was observed between HPV infection and age or gender. To address HPV as a risk factor for OSCC, public health initiatives such as vaccination, awareness campaigns, and accessible healthcare services should be implemented. They are, furthermore, incorporating HPV DNA testing into practice.

Long-term prediction by DNA methylation of high-grade cervical intraepithelial neoplasia: Results of the ARTISTIC cohort.

Methylation markers have shown potential for triaging high-risk HPV-positive (hrHPV+) women to identify those at increased risk of invasive cervical cancer (ICC). Our aim was to assess the performance of the S5 DNA methylation classifier for predicting incident high-grade cervical intraepithelial neoplasia (CIN) and ICC among hrHPV+ women in the ARTISTIC screening trial cohort. The S5 classifier, comprising target regions of tumour suppressor gene EPB41L3 and L1 and L2 regions of HPV16, HPV18, HPV31, and HPV33, was assayed by pyrosequencing in archived hrHPV+ liquid-based samples from 343 women with high-grade disease (139 CIN2, 186 CIN3, and 18 ICC) compared to 800 hrHPV+ controls. S5 DNA methylation correlated directly with increasing severity of disease and inversely with lead time to diagnosis. S5 could discriminate between hrHPV+ women who developed CIN3 or ICC and hrHPV+ controls (p <.0001) using samples taken on average 5 years before diagnosis. This relationship was independent of cytology at baseline. The S5 test showed much higher sensitivity than HPV16/18 genotyping for identifying prevalent CIN3 (93% vs. 61%, p = .01) but lower specificity (50% vs. 66%, p <.0001). The S5 classifier identified most women at high risk of developing precancer and missed very few prevalent advanced lesions thus appearing to be an objective test for triage of hrHPV+ women. The combination of methylation of host and HPV genes enables S5 to combine the predictive power of methylation with HPV genotyping to identify hrHPV-positive women who are at highest risk of developing CIN3 and ICC in the future.

Synergistic Attention-Guided Cascaded Graph Diffusion Model for Complementarity Determining Region Synthesis.

Complementarity determining region (CDR) is a specific region in antibody molecules that binds to antigens, where a small portion of residues undergoes particularly pronounced variations. Generating CDRs with high affinity and specificity is a pivotal milestone in accelerating drug development for daunting and unresolved diseases. However, existing approaches predominantly center on characterizing the attributes of residues through sequential generation models, thus falling short in effectively modeling the intricate spatial correlations among residues and frequently succumbing to the trap of generating sequences that exhibit a high degree of arbitrariness. In this article, we propose a novel synergistic attention-guided cascaded graph diffusion model, termed GraphCas, which offers a pathway for optimized generation of high-affinity CDRs. Our approach is the first cascaded-based graph diffusion model for CDR synthesis. Specifically, we design a graph propagation algorithm with a relation-aware synergistic attention mechanism, enabling the targeted acquisition of structural insights from diverse protein sequences and bolstering the global information representation of the graph by precisely localizing to long-range key residue sites. We design a cascaded conditional enhanced diffusion approach, providing the capability to incorporate additional control constraints into the input. Experimental results demonstrate that GraphCas can generate photo-realistic CDRs and achieve performance comparable to top-tier approaches. In particular, GraphCas reduces the RMSD by nearly 0.42 units in the H1 region and improves the ERRAT by 9.36% points in the L1 region.

Aspirin in a new role in human body

In 1897, German chemist Felix Hoffman synthesized acetylsalicylic acid, known as aspirin, which revolutionized its widespread modern use for pain relief. Aspirin acts as an inhibitor of cyclooxygenase-1 (COX-1) and has a modifying effect on the enzymatic activity of cyclooxygenase-2 (COX-2). It inhibits the production of prostaglandins, crucial for various physiological processes, and has been linked to a reduced risk of pre-eclampsia and preterm delivery before 34 weeks of pregnancy. However, aspirin's COX-1 inhibition is irreversible and long-lasting, requiring new enzymes to replace those acetylated. Low-dose aspirin has been reported to increase bone mineral density (BMD) in elderly individuals, coinciding with the growing prevalence of osteoporosis. However, a definitive connection between the use of low-dose aspirin and BMD remains elusive. A study examined the relationship between low-dose aspirin use and BMD in adults aged 50 to 80. A higher BMD in the femur, intertrochanter, and L1 regions compared to those who do not use aspirin was reported. However, the abstract acknowledges limitations and emphasizes the need for future research, including randomized controlled trials, to establish a causal relationship between low-dose aspirin use and enhanced bone density.

HPV16 Intratypic Variants in Head and Neck Cancers: A North American Perspective.

Human papillomavirus (HPV) is the major causative agent for cervical and many head and neck cancers (HNCs). HPVs randomly acquire single nucleotide polymorphisms (SNPs) that may become established via positive selection. Within an HPV type, viral isolates differing by <2% in the L1 region are termed "variants" and classified based on combinations of SNPs. Studies in cervical cancer demonstrate clear differences between HPV16 intratypic variants in terms of persistence of infection, tumor histology, cancer risk, and death. Much less is known about the frequency of HPV16 variants in HNC, and their effects on clinical outcomes. We combined HPV16 positive (HPV16+) HNC samples from a local Southwestern Ontario, Canada cohort with those from the Cancer Genome Atlas to create a larger North American cohort of 149 cases with clinical data and determined the distribution of intratypic variants and their impact on clinical outcomes. Most isolates were lineage A, sublineage A1, or A2, with roughly half exhibiting the T350G polymorphism in E6. Univariable analysis identified significant differences between 350T and 350G intratypic variants in clinical T, N, and O staging, as well as disease-free survival. Multivariable analysis failed to identify any clinical factor as a statistically significant covariate for disease-free survival differences between 350T and 350G. Significant differences in several measures of B-cell mediated immune response were also observed between 350T and 350G intratypic variants. We suggest that HPV genetic variation may be associated with HNC clinical characteristics and may have prognostic value.

HPV18 L1 and long control region sequences variation and E6/E7 differential expression in nasopharyngeal and cervical cancers: a comparative study

BackgroundThe role of high-risk human papillomaviruses (hr-HPVs) in cervical cancer (CC) pathogenesis has long been established. Knowledge about the involvement of hr-HPVs in the etiology of nasopharyngeal cancers (NPC) was not well appreciated until the early 2000s when a clear link began to emerge. However, it is not clear whether HPV oncogenesis in the different epithelial cancers is associated with L1 gene and long-control region (LCR) sequences variation. This study aimed to investigate the HPV18 L1 gene and LCR sequences variation in cervical and nasopharyngeal biopsies, and assessed E6 and E7 genes expression level in both cancers.MethodFour-hundred and three (403) formalin-fixed paraffin-embedded tissues originating from nasopharyngeal (NPC) (279) and cervical (CC) (124) sites were collected from a pathology laboratory, Pathologist Without Borders, Accra, Ghana. Haematoxylin and eosin staining was carried out to confirm the presence of cancer on prepared biopsy sections. DNA was extracted from the confirmed cancer biopsies, followed by PCR using MY09/GP5+ /6+ primers to detect the presence of HPV and specific primers for the amplification of L1 gene and LCR. Sanger sequencing was carried out to determine HPV genotypes, and L1 and LCR sequences variant of HPV18s in CC and NPC biopsies. The HPV18 E6/E7 mRNA expression pattern in both cancers was determined using RT-qPCR.ResultsMost of the NPC (45%) and CC (55%) biopsies were HPV18 positive. Comparison of HPV18 L1 sequences obtained from cervical and nasopharyngeal cancer tissues, the L1 sequences from the NPC were highly dissimilar with a 59–100% variation among themselves, and in relation to the reference strains. However, the L1 sequences from the CC were more similar with a 91.0–100% variation among the amplified sequences. Also, the LCR sequences from CC were quite different relative to that of NPC. Results for the differential expression of E6/E7 in the two cancers showed a higher fold change in E6 expression in the CC tissues than the NPC tissues while a reverse expression pattern was found for E7 gene.ConclusionThe current study reports for the first-time variations in HPV18 L1 and LCR sequences, and differential expression of E6/E7 genes in NPC compared to CC, suggesting a possible adaptation mechanism of the virus at different cancer sites.

The Study of Clinical Phenotypes and Analysis of Mutations in L1 Syndrome

The Study of Clinical Phenotypes and Analysis of Mutations in L1 Syndrome

Development of a simplified and cost-effective sample preparation method for genotyping of human papillomavirus by next-generation sequencing.

High-risk human papillomavirus (HPV) infection is the most common cause of cervical cancer, but low-risk HPV strains can sometimes also be involved. Although HPV genotyping techniques used in clinical diagnosis cannot detect low-risk HPV, next-generation sequencing (NGS) can detect both types. However, DNA library preparation is complicated and expensive. The aim of this study was to develop a simplified, cost-effective sample preparation procedure for HPV genotyping based on next-generation sequencing (NGS). After DNA extraction, a first round of PCR was performed using modified MY09/11 primers specific for the L1 region of the HPV genome, followed by a second round of PCR to add the indexes and adaptors. Then, the DNA libraries were purified and quantified, and high-throughput sequencing was performed using an Illumina MiSeq platform. The sequencing reads were compared with reference sequences for HPV genotyping. The limit of detection for HPV amplification was 100 copies/µl. Analysis of the correlation of pathological cytology with the HPV genotype in individual clinical samples showed that HPV66 was the most common genotype found in the normal stage, whereas HPV16 was the main genotype found in low-grade squamous intraepithelial lesions, high-grade squamous intraepithelial lesions, and cervical cancer. This NGS method can detect and identify several HPV genotypes with 92% accuracy and 100% reproducibility, and it shows potential as a simplified and cost-effective technique for large-scale HPV genotyping in clinical samples.