The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its Omicron subvariants drastically amplifies transmissibility, infectivity, and immune escape, mainly due to their resistance to most neutralizing antibodies. Thus, exploring the mechanisms underlying antibody evasion is crucial. Although the full-length native form of antibody, immunoglobulin G (IgG), offers valuable insights into the neutralization, structural investigations primarily focus on the fragment of antigen-binding (Fab). Here, we employ single-particle cryo-electron microscopy (cryo-EM) to characterize a W328-6H2 antibody, in its native IgG form complexed with severe acute respiratory syndrome (SARS), severe acute respiratory syndrome coronavirus 2 wild-type (WT) and Omicron variant BA.1 spike protein (S). Three high-resolution structures reveal that the full-length IgG forms a centered head-to-head dimer of trimer when binds fully stoichiometrically with both SARS and WT S, while adopting a distinct offset configuration with Omicron BA.1 S. Combined with functional assays, our results suggest that, beyond the binding affinity between the RBD epitope and Fab, the higher-order architectures of S trimer and full-length IgG play an additional role in neutralization, enriching our understanding of enhanced neutralization by SARS-CoV-2 antibodies.

The 2003 severe acute respiratory syndrome coronavirus (SARS-CoV-1) causes more severe disease than SARS-CoV-2, which is responsible for COVID-19. However, our understanding of antibody response to SARS-CoV-1 infection remains incomplete. Herein, we studied the antibody responses in 25 SARS-CoV-1 convalescent patients. Plasma neutralization was higher and lasted longer in SARS-CoV-1 patients than in severe SARS-CoV-2 patients. Among 77 monoclonal antibodies (mAbs) isolated, 60 targeted the receptor-binding domain (RBD) and formed 7 groups (RBD-1 to RBD-7) based on their distinct binding and structural profiles. Notably, RBD-7 antibodies bound to a unique RBD region interfaced with the N-terminal domain of the neighboring protomer (NTD proximal) and were more prevalent in SARS-CoV-1 patients. Broadly neutralizing antibodies for SARS-CoV-1, SARS-CoV-2, and bat and pangolin coronaviruses were also identified. These results provide further insights into the antibody response to SARS-CoV-1 and inform the design of more effective strategies against diverse human and animal coronaviruses.

Abstract Background The occurrence and progression of various solid tumors are associated with the melanoma-associated antigen A (MAGE-A) family. Although it was demonstrated that demethylation at the promoter region usually causes the over-expression of the MAGE-A family, there has been very few research about the detailed mechanisms of how the genetic modification of promoter region promotes MAGE-A expression.Methods A new non-coding RNA (ncRNA) with the ability of binding with melanoma-associated antigen-A6 (MAGE-A6) promoter region was discovered. The expression consistency between MAGE-A6 and this novel ncRNA in different MAGE-A6 highly expressed malignant cell lines was analyzed by RT-qPCR. The full length of this ncRNA was acquired through RACE and were subsequently named as MAGEA6-DT1. Then up- and down-regulation of MAGEA6-DT1 in human malignant melanoma cells were achieved by lentivirus transduction and siRNA transfection respectively and the transcription and expression of MAGE-A6 was detected by RT-qPCR and Western Blot for verifying MAGE-A6 expression regulating function of MAGEA6-DT1. The exact binding site of MAGEA6-DT1 in MAGE-A6 promoter region was analyzed by dual-luciferase reporter system assay after MAGEA6-DT1 transfection in 293T cells. Moreover, by DNA methylation analysis, we tested whether MAGEA6-DT1 has the ability of MAGE-A6 expression regulation by manipulating its promoter region’s methylation. Finally, RNA pull-down assay was performed to identify the functional binding partner of MAGEA6-DT1.Results MAGEA6-DT1 was identified as a long non-coding RNA (lncRNA) with the length of 771 nucleotides and was abnormally expressed in consistency with MAGE-A6 among various cancer cell lines. Manipulation of MAGEA6-DT1 expression level would positively regulates MAGE-A6 expression. Specific binding site of MAGEA6-DT1 located near the enhancer of MAGE-A6, and its function was revealed to demethylate DNA near its binding site, probably with the assistance of relevant binding partners.Conclusion MAGEA6-DT1, as a lncRNA abnormally expressed in different malignant cell lines, could positively regulate MAGE-A6 expression via specifically combining with and subsequently demethylating MAGE-A6 enhancer. This function may be assisted by some of its binding protein such as DNA (cytosine-5)-methyltransferase 1 (DNMT1).

The melanoma antigen gene family A (MAGEA) family of proteins comprises of cancer-testis antigens that are highly expressed in a number of tumours but are minimally expressed in normal cells. Due to its expression characteristics, this protein family has become a popular target for anti-cancer drugs and immunotherapy research over recent years. Although, elevated expression levels of MAGEA6 has been found in different types of tumours, there remains to be insufficient information on the function of MAGEA6 and its associated gene regulation pathways. The present study used Transwell, Cell Counting Kit-8 and wound healing assays to analyse the effects of MAGEA6 on Eca109 cell invasion, migration and proliferation. The main functions and pathways involved in MAGEA6 were predicted by Illumina Hiseq screening for mutually regulated genes and core genes. Eca109 cell line with a high expression of MAGEA6 was a stable cell line obtained by transfection in the early stage, and this cell line was used in subsequent experiments. Transcriptome sequencing was performed on this cell line and the Eca109 cell line that normally expressed MAGEA6. It was revealed that a high expression of MAGEA6 conferred a significant stimulating effect on cell proliferation whilst also significantly increasing cell invasion and migration. Transcriptomic analysis identified 14 differentially expressed genes and 13 core regulatory genes closely associated with MAGEA6 expression regulation, such as methylsterol monooxygenase 1 (MSMO1). The present study suggest that MAGEA6 positively regulated MSMO1 expression, which may serve an oncogenic role in cells through this regulatory effect. Overall, this provided a novel route of investigation for an in-depth study of the regulatory function of MAGEA6.

Human papillomavirus is an important cancer factor in many cancers. E6E7 is the important viral oncogene and plays an important role. It is known that its function is to regulate p53 and pRb. In this paper, in situdetection was performed to determine the interaction between them; the research provides visual evidence of their interaction. Research methods: In situ PLA reaction was used to detect the relationship between two different protein. Results: The quantity of the HPV18E6 expression is much higher than the expression of HPV18E7 protein in HeLa and EC109 cells; the interaction between p53-E6 and pRb-E7 was clearly observed and this effect could be visualized by this method. Conclusion: Interaction of the HPV18E6 protein combined with p53 protein and HPV18E7 protein combined with pRb protein could be visualized in cell.

The development of esophageal cancer accompanied by the presence of human papillomavirus (HPV) DNA into the host genome. By evaluating the expression of this virus for tumor cell origin and also their cell grows and migrations, we examined esophageal cancer clonality in the context of intra-tumor heterogeneity. In this research, we have checked the expression of HPV18 E6 and E7 in different single cell clones by the manual cell picking method in the HPV positive esophageal cancer (EC109), EC109 cell line used as a negative control, and Hela cell line used as the positive control. Quantitative real-time PCR (QRT-PCR) was run to detect the expression levels of HPV E6 and E7, Cell Counting Kit-8 (CCK-8) assay was used to examine cell proliferation, invasion assays performed using Costar chambers and wounding assay to study cell migrations in vitro. We investigated the intra-tumor heterogeneity of HPV E6 and E7 in esophageal cancer and the evaluation of the growth and migrations at the clonal level, using 10 single cell clones. In particular clones, C7 & C10 displayed a highly variable expression in both HPV E6 and E7 and weak in four clones (C1, C3, C4, and C9) consequently, the cell invasion, proliferation, and migration increase with increasing the level of HPV expression and inverse. In conclusion, the resulting based on single cell cloning showed the relationship between HPV and cell growth and migration in esophageal cancer. Future study in HPV DNA integration needed to explore the mains specific integration site of HPV DNA in esophageal cancer and molecular monitoring of the HPV for future prevention researches and also effective therapeutic strategies.

Esophageal carcinoma (EC) is the sixth most deadly of all cancers. It is among the most malignant cancers due to its highly aggressive nature and low survival rate. The incidence of EC is high in Asia, particularly in Southern areas including China, Iran and Japan. There is a large body of evidence to suggest an association between the melanoma antigen gene (MAGE) family and the initiation of cancer; however, there is no clear evidence to suggest an association between EC and MAGE. Discovery of the chemical and physiological processes relevant to the occurrence of EC is vital for clinicians to diagnose and treat this highly aggressive cancer. The present study focused on the association of EC with the expression of MAGE family member A6 (MAGEA6) at the mRNA and protein levels using gene chip, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry. The expression of MAGEA6 in human esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) tissue samples were compared with those in paracancerous tissue. The result of the gene chip assay revealed that as the generation grew, there was a significant increase in MAGEA6 transcription in the esophageal epithelial cell line, SHEE Different ESC cell lines also exhibited a significantly higher transcription of MAGEA6 compared with the HaCaT cell line, as determined via reverse transcription-quantitative PCR. An higher positive rate of MAGEA6 expression in ESCC and EAC tissues was also revealed when compared with paracancerous tissues, as determined via immunohistochemistry. The results indicated that MAGEA6 is highly transcribed and expressed in the development of EC and may therefore serve as a novel biomarker for the diagnosis or treatment of EC.

The aim of this study was to detect the presence and mutation of human papillomavirus 18 E5 gene in esophageal carcinoma tissue specimens from Tangshan region, a high-incidence area of China. 94 esophageal carcinoma tissue specimens with diagnosis of HPV18 positive were obtained by a pathology department in Tangshan, from 2011 to 2013. DNA of all 94 samples was extracted, and the quality of the DNA extraction was tested by a beta-globin PCR. Type-specific PCR was performed to detect the presence of HPV18 E5 gene in extracted DNA of tissue specimens. The PCR products of E5 gene were sequenced and the mutation sites were analyzed. Our results showed that the quality of DNA extraction in these tissue samples were 100% qualified. 34/94(36%) of specimens could detect the presence of HPV18 E5 DNA sequences, and 4/34(12%) of samples occurred sequence mutation. 3/4(75%) of the mutations happened in the initiation codon sites. This study revealed that HPV18 E5 may play an important role in progression of esophageal carcinoma.

OBJECTIVE:The incidence of the upper gastrointestinal tumor has increased rapidly during recent decades. The relationship between local water pollution and the tumor is still not much clear, so this study was conducted to further investigate the local water pollution and its influence on the malignant cell transformation. Prevalence of human papillomavirus (HPV) in local esophageal cancer (EC) patients was also analyzed in Shenqiu County for the first time.METHODS:Two-step cell transformation was used to study different sources of water in the malignant cell transformation, and the existence of 3-methylcholanthrene (3-MC) in water was analyzed from the river and shallow and deep wells. HPV DNA in tissue samples of EC patients was detected by polymerase chain reaction (PCR) and HPV diagnostic kit.RESULTS:The river water has higher cytotoxicity than the shallow well water and induced significant cell malignant transformation, while deep well water has not shown the malignant cell transformation. In Huaihe River water, the 3-MC concentration was found higher than shallow and deep wells. An HPV infection rate was found high in patients with esophageal cancer.CONCLUSION:Long-term consumption of polluted water can induce malignant cell transformation, and the presence of HPV may be an important cause of cancer.

Esophageal cancer is one of the leading malignancies globally and long non-coding RNAs (lncRNAs) have been proved to have an important role in different malignancies including esophageal cancer. However their role in disease progression is still not clear. The objective of the study was to investigate the expression and role of LINC01234 in progression of esophageal cancer cells. LncRNA LINC01234 was found to be upregulated in esophageal cancer cells by chip sequencing. The expression level of LINC01234 was detected from different esophageal cancer cell lines by qRT-PCR. After this, the LINC01234 knockdown effects on cell proliferation, migration, invasion, and apoptosis were evaluated by cell proliferation assay, wound healing assay, invasion assay, and flow cytometric analysis in vitro. Expression of lncRNA LINC01234 was found to be markedly upregulated in the CEC2 cell line. Furthermore, cell proliferation, migration and invasion were significantly (P < 0.05) suppressed as compared to negative control while apoptotic rate was also found increased as a result of the knockdown of LINC01234. Significantly upregulated expression of LINC01234 in CEC2 cells and downregulated expression after knockdown is observed. The impact of LINC01234 knockdown on cell migration, invasion, proliferation and apoptosis indicated that LINC01234 may represent a new marker and a potential therapeutic target for esophageal cancer.

The aim of the research is to investigate the expression of the cell cycle relative proteins (P53, P16, Cyclin D1, and Ki67) in Esophageal Cancer (EC) patients of the Chaoshan area, China. In China, Chaoshan has the high incidence of EC. Different areas have shown different rate for expression of these proteins in EC. We investigated the expression of p53, p16, cyclinD1, and ki67 for the first time in Chaoshan. In this research, DNA was extracted from formalin fixed and paraffin embedded tissues of esophageal cancer (EC) patients. The expression level of proteins cycle was detected by using immunohistochemistry (IHC). And the data was checked by χ2 test or Fisher’s exact test of SPSS17.0. The positive immunohistochemical staining of p53, p16, cyclinD1, and ki67 were observed in 65.7% 39.2%, 69.1%, and 83.5% specimens respectively. There was a positive correlation between p53 positive staining and p16, cyclinD1, ki67 staining at p was considered between the expression of p16 and cyclinD1 and there was no correlation observed between p16 and ki67. In Conclusion, this study demonstrated the high expression of p53, Cyclin D1 and Ki67 and low expression of P16 and the association of these cell cycle relative proteins in esophageal cancer are new data in Chaoshan area of China. Geographical distribution of EC on the molecular basis is revealed in this research.

Cancers are multifactorial but the advancement in research in the recent decades have drawn attention towards lncRNAs as they are proven to play important function as biological regulators. LINC01234, CASC9 are important long non coding RNAs (lncRNAs). They are not extensively studied therefore, their role in esophageal cancer as well as in other cancers is still not clear. There are few studies about LINC01234 and CASC9 for their role in esophageal cancer. The objective of the study was to investigate the expression of LINC01234 and CASC9 in different cell lines. Our lab cultured and maintained model esophageal cancer cells which were obtained after transformation of human embryonic esophageal epithelial cells into malignant cells by HPV18 E6E7. After this, elevated expression of LINC01234 was found in Gene Chip showing that it may have some role in causing esophageal cancer. For further verification, qRT-PCR was used for the detection of expression level of LINC01234 in different cell lines. Furthermore, expression of CASC9 was also investigated by qRT-PCR in different cell lines. Expression of LINC01234 and CASC9 was markedly high in esophageal cancer cell lines as compared to other cell lines while high expression of LINC01234 was also found in one lung cancer cell line. These lncRNAs may be used as biomarker and potential therapeutic target for esophageal cancer intervention by further exploration of their functions.

Aims: The integration preferences of human papillomavirus (HPV) have been intensively studied and contested over recent years. To disclose the integration preferences of high-risk HPV in cervical cancer, HPV transcriptional sites and features in different cervical cancer cell lines were identified.Main methods: In this study, three cervical cancer cell lines (CaSki, HeLa, and SiHa) were subjected for HPV genome status determination by amplification of papillomavirus oncogene transcripts (APOT) assay. The numbers of viral copies in human genomes and numbers of viral-human fusion mRNAs in three HPV-integrated cervical cancer cell lines were measured and analysed.Key findings: The results revealed that the gene desert region 8q24 of the HPV type 18 integrated HeLa cell line and the 13q21-22 region of the HPV type 16 integrated CaSki and SiHa cell lines were hotspots for HPV integration, and the numbers of viral copies in the human genomes of the three cell lines that we detected were not in accordance with those reported in previous studies.Significance: Integration of the HPV genome into the host cell chromosome suggests that persistent HPV infection is vital for malignant cell transformation and carcinogenesis. This study provides information to benefit health care professionals seeking more comprehensive and accurate diagnostics for HPV-related disease"? Please check, and amend as necessary. (C) 2015 Elsevier Inc. All rights reserved.