News

A review of human carcinogens—Part B: biological agents

Non-Hodgkin's lymphoma incidence rates vary between European and Asian populations. The reasons remain unclear. This two-sample two-step Mendelian randomisation (MR) study aimed to investigate the causal relationship between anthropometric indicators (AIs) and diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) and the possible mediating role of basal metabolic rate (BMR) in Europe.

We used the following AIs as exposures: body mass index (BMI), whole-body fat mass (WBFM), whole-body fat-free mass (WBFFM), waist circumference(WC), hip circumference(HC), standing height (SH), and weight(Wt). DLBCL and FL represented the outcomes, and BMR was a mediator. A two-sample MR analysis was performed to examine the association between AIs and DLBCL and FL onset. We performed reverse-MR analysis to determine whether DLBCL and FL interfered with the AIs. A two-step MR analysis was performed to determine whether BMR mediated the causality.

WBFFM and SH had causal relationships with FL. A causal association between AIs and DLBCL was not observed. Reverse-MR analysis indicated the causal relationships were not bidirectional. Two-step MR suggested BMR may mediate the causal effect of WBFFM and SH on FL.

We observed a causal relationship between WBFFM and SH and the onset of FL in Europeans, Which may explain the high incidence of follicular lymphoma in Europeans.

EBV latent membrane protein 1 (LMP-1) is an important oncogene involved in the induction and maintenance of EBV infection and the activation of several cell survival and proliferative pathways. The genetic diversity of LMP-1 has an important role in immunogenicity and tumorigenicity allowing escape from host cell immunity and more metastatic potential of LMP-1 variants. This study explored the evolutionary of LMP-1 in EBV-infected patients at an advanced stage of nasopharyngeal carcinoma (NPC). Detection of genetic variability in LMP-1 genes was carried out using Sanger sequencing. Bioinformatic analysis was conducted for translation and nucleotide alignment. Phylogenetic analysis was used to construct a Bayesian tree for a deeper understanding of the genetic relationships, evolutionary connections, and variations between sequences. Genetic characterization of LMP-1 in NPC patients revealed the detection of polymorphism in LMP-1 Sequences. Motifs were identified within three critical LMP-1 domains, such as PQQAT within CTAR1 and YYD within CTAR2. The presence of the JACK3 region at specific sites within CTAR3, as well as repeat regions at positions (122−132) and (133–143) within CTAR3, was also annotated. Additionally, several mutations were detected including 30 and 69 bp deletions, 33 bp repeats, and 15 bp insertion. Although LMP-1 strains appear to be genetically diverse, they are closely related to 3 reference strains: prototype B95.8, Med- 30 bp deletion, and Med + 30 bp deletion. In our study, one of the strains harboring the 30 bp deletion had both bone and bone marrow metastasis which could be attributed to the fact that LMP-1 is involved in tumor metastasis, evasion and migration of NPC cells. This study provided valuable insights into genetic variability in LMP-1 sequences of EBV in NPC patients. Further functional studies would provide a more comprehensive understanding of the molecular characteristics, epidemiology, and clinical implications of LMP-1 polymorphisms in EBV-related malignancies.

To suit the needs of the human papillomaviruses (HPV) community comprehensively, a range of commercial HPV tests with different performance characteristics are required. Four periodic inventories of commercial HPV molecular tests present in the global market were published previously in 2010, 2012, 2015 and 2020. For the fifth inventory, data were retrieved from internal files and a detailed search using the main bibliographic databases as well as general internet search without period or language restrictions was performed in December 2023. At least 264 distinct HPV tests (and 511 test variants) were available globally in December 2023. A small 2020–2023 net increase in total numbers was observed, but with a strong introduction/withdrawal dynamic: 86 new distinct HPV tests (and 141 variants) were introduced and 76 tests (and 55 variants) were withdrawn from the market in the last four years. Although quality improvement of some tests was recorded, half of all HPV tests are still without a single peer-reviewed publication, and 79 % of tests are without published evidence that demonstrate performance characteristics are in line with requirements agreed in the HPV community. Only a relatively small pool of tests fulfill the operational/performance characteristics required to meet the global cervical cancer screening challenge. Although clinical and analytical performance characteristics of many commercial HPV tests are largely unknown, such tests are used worldwide in daily clinical practice and research, with potentially deleterious consequences. Due to this long-lasting unfavorable situation, significant scope for improvement persists for both manufacturers of HPV tests and the HPV community.

Opisthorchiasis is one of the most serious trematodiases in Russia, where the world's largest focus is located in the Ob basin. Temperature is an important factor affecting the metabolism of cold-blooded animals. It determines the development of the causative agent of opisthorchiasis, Opisthorchis felineus, and the success of infection of an intermediate host, the snail Bithynia troschelii. In the present study, the effect of water temperature on the development of the liver fluke O. felineus in the host snail was assessed, as was the temperature threshold at which B. troschelii hibernation initiates. Adult uninfected B. troschelii individuals collected from natural bodies of water were infected with O. felineus and maintained at different temperatures of water (18–30 °C, intervals of 3 °C) in the laboratory. Each snail was fed with embryonated uterine eggs of O. felineus at 24 °C. O. felineus infection in snails was detected using polymerase chain reaction (PCR) using specific primers. The prevalence of O. felineus infection in B. troschelii depends on the water temperature in which the snails are maintained. The highest infection rate of 45.2 % ± 12.1 % was observed at 27 °C (p ≥ 0.1). The longest lifespan of infected and uninfected B. troschelii was recorded at water temperatures of 24 and 27 °C. The snails were more successfully infected at the beginning of the warm season. Among the infected individuals, the majority (up to 85 %) were large snails. Cercarial shedding was not detected in experimentally infected snails. Apparently, this is due to the natural physiological state of Bithynia snails during the autumn–winter diapause, when opisthorchiids development in snails stops. At 10 °C, complete hibernation of all B. troschelii snails was observed, and infection by the trematodes became impossible. The highest prevalence of infection was recorded at 27 °C, suggesting that during climate warming, an increase in opisthorchiid infection of snails may occur, which must be considered when epidemiological measures are planned.

The risk of developing cervical squamous lesions in women with multiple high-risk human papillomavirus (hrHPV) infections is uncertain. The aim of this retrospective study was to investigate the type-specific attribution and phylogenetic effects of single and multiple hrHPV subtypes in cervical squamous lesions. All cases with cervical histopathologic diagnosis and human papillomavirus (HPV) genotyping results in the 6 months preceding biopsy from October 2018 to December 2022 were studied and analyzed. Over the study period, 70,361 cases with histopathologic follow-up and prior HPV genotyping were identified. The hrHPV-positive rate was 55.6% (39,104/70,361), including single hrHPV detected in 27,182 (38.6%), 2 types of hrHPV detected in 8158 (11.6%), and 3 types of hrHPV detected in 2486 (3.5%). Among 16,457 cases with a histologically diagnosed squamous lesion (cervical intraepithelial neoplasia 1: 11411; cervical intraepithelial neoplasia 2/3: 4192; squamous cell carcinoma: 854 cases), the prevalence of single hrHPV infection increased, but the rate of multiple concomitant hrHPV infections showed negative association as the degree of squamous lesions increased. Among women with a single HPV16 infection, cervical intraepithelial neoplasia 2/3 and squamous cell carcinoma (CIN2+) diagnostic rate was 30.6%, and it increased to 47.6% when coinfected with HPV33 (P < .001) but significantly decreased when coinfected with all other hrHPV types (P < .05). By comparing CIN2+ diagnostic rates in 40 most common 2 types of hrHPV infections with related single hrHPV infection, CIN2+ rates were decreased in 12 combinations (30.0%), equivalent in 26 combinations (65.0%), and increased in 2 combinations (5.0%). The cases with 3 types of HPV infections reduced the risk for CIN2+ compared with related single HPV infections. HPV16+52+53, HPV16+52+68, HPV16+52+51, HPV16+39+52, and HPV16+58+53 significantly decreased the risk of CIN2+ compared with HPV16 single infection (P < .05). This study demonstrates that multiple hrHPV infections are not associated with cumulatively higher risk for CIN2+ development, suggesting that oncogenic progression of multiple hrHPV-associated cervical squamous lesions is neither synergistic nor a cumulative effect at the phylogenetic level, possibly a way of competitive interference.

Human papillomavirus (HPV)-associated cancers, including oropharyngeal squamous cell carcinoma (HPV + OPSCC), cervical cancer, and squamous cell carcinoma of the anus (HPV + SCCA), release circulating tumor HPV DNA (ctHPVDNA) into the blood. The diagnostic performance of ctHPVDNA detection depends on the approaches used and the individual assay metrics. A comparison of these approaches has not been systematically performed to inform expected performance, which in turn affects clinical interpretation. A meta-analysis was performed using Ovid MEDLINE, Embase, and Web of Science Core Collection databases to assess the diagnostic accuracy of ctHPVDNA detection across cancer anatomic sites, detection platforms, and blood components. The population included patients with HPV + OPSCC, HPV-associated cervical cancer, and HPV + SCCA with pretreatment samples analyzed by quantitative PCR (qPCR), digital droplet PCR (ddPCR), or next-generation sequencing (NGS). Thirty-six studies involving 2986 patients met the inclusion criteria. The sensitivity, specificity, and quality of each study were assessed and pooled for each analysis. The sensitivity of ctHPVDNA detection was greatest with NGS, followed by ddPCR and then qPCR when pooling all studies, whereas specificity was similar (sensitivity: ddPCR > qPCR, P < 0.001; NGS > ddPCR, P = 0.014). ctHPVDNA from OPSCC was more easily detected compared with cervical cancer and SCCA, overall (P = 0.044). In conclusion, detection platform, anatomic site of the cancer, and blood component used affects ctHPVDNA detection and must be considered when interpreting results. Plasma NGS-based testing may be the most sensitive approach for ctHPVDNA overall.