Nasopharyngeal Cells Research Articles

The Effects of Severe Symptoms of SARS-CoV-2 Infections on the Anti/Proapoptotic Molecules: A 6-Month Cohort Study.

The plausible effects of SARS-CoV-2 infection on the expression of anti/proapoptotic molecules have been suspected. This cohort study examined the expression of p53, Bcl-2, Bid, Bak, and Bax molecules, the genes associated with induction or inhibition of apoptosis, in the SARS-CoV-2-infected patients with severe and mild symptoms in an Iranian population. In this 6-month cohort study, the expression of p53, Bcl-2, Bid, Bak, and Bax molecules was evaluated at onset of diagnosis, 24 h after symptom onset, and 6 months later in the nasopharyngeal cells of SARS-CoV-2-infected hospitalized patients and outpatients in comparison with healthy controls using the real-time PCR technique. At the onset of the study, the relative expression of p53, Bcl-2, Bid, Bak, and Bax significantly increased in the SARS-CoV-2-infected hospitalized patients and decreased after 6 months. The healthy controls showed potential positive correlations among the molecules, but the patients did not show these correlations. Since SARS-CoV-2 needs host cell survival, it appears that the virus induces the expression of Bcl-2 as an antiapoptotic molecule, and the host cells upregulate the proapoptotic molecules to neutralize the effects. Dysregulation of correlation expression of the molecules among the patients proved that SARS-CoV-2 affects the expression of the molecules involved in apoptosis. SARS-CoV-2 could be considered an important factor that regulates the expression of several molecules participating in cancer pathogenesis.

The association between infectious agents and breast cancer: a review of the epidemiologic evidence.

Several viruses have been casually linked to human cancers, including cervical, nasopharyngeal, liver, sarcoma, and Merkel cell carcinomas. However, the etiologic contribution of viral infections to breast cancer, the number one incident cancer among women worldwide, is not well established. Among studies exploring associations of viruses with breast cancer, potential linkages have been identified between breast cancer and five viruses: beta retrovirus, (i.e., mouse mammary tumor virus), human papillomavirus, Epstein Barr virus. bovine leukemia virus, and human cytomegalovirus. In this review, we provide a comprehensive evaluation of epidemiological ecologic, case-control, case-only, and cohort studies investigating these associations. Wediscuss results from several existing reviews and meta-analyses, evaluate epidemiological studies published in the past five years, and assess the relationship between these viruses and breast tumor clinicopathological factors. The strongest epidemiological evidence for a viral role in breast cancer exists for MMTV and HPV, though limitations include lack of prospective studies for MMTV and potential detection bias in HPV studies. Viral detection challenges have limited studies of EBV and HCMV. Fewer studies have evaluated BLV, and though it has been associated with higher risk of breast cancer, sample sizes are quite small. CONCLUSION: While epidemiologic evidence exists for an association between these five viruses and breast cancer, various methodological issues and lack of prospective studies preclude robustconclusions. Future research should prioritize establishing a temporal relationship between infection and disease, minimizing misclassification of detection assays, and further exploring the influence of co-infections.

Ultrastructural, metabolic and genetic characteristics of determinants facilitating the acquisition of macrolide resistance by Streptococcus pneumoniae

AimsTo investigate the molecular events associated with acquiring macrolide resistance genes [mefE/mel (Mega) or ermB] in Streptococcus pneumoniae (Spn) during nasopharyngeal colonization. Methods and resultsGenomic analysis of 128 macrolide-resistant Spn isolates revealed recombination events in genes of the conjugation apparatus, or the competence system, in strains carrying Tn916-related elements. Studies using confocal and electron microscopy demonstrated that during the transfer of Tn916-related elements in nasopharyngeal cell biofilms, pneumococcal strains formed clusters facilitating their acquisition of resistance determinants at a high recombination frequency (rF). Remarkably, these aggregates comprise both encapsulated and nonencapsulated pneumococci that span extracellular and intracellular compartments. rF assessments showed similar rates regardless Mega was associated with large integrative and conjugative elements (ICEs) (>23 kb) or not (∼5.4 kb). The rF for Mega Class IV(c) insertion region (∼53 kb) was three orders of magnitude higher than the transformation of the capsule locus. Metabolomics studies of the microenvironment created by colonization of human nasopharyngeal cells revealed a link between the acquisition of ICEs and the pathways involving nicotinic acid and sucrose. ConclusionsPneumococcal clusters, both extracellular and intracellular, facilitate macrolide resistance acquisition, and ICEs were acquired at a higher frequency than the capsule locus. Metabolic changes could serve as intervention targets.

Synthesis of gold nanoparticles using Ginkgo biloba leaf extract and its in vitro anticancer effects on nasopharyngeal carcinoma cells

Green synthesis of gold nanoparticles (AuNPs) using Ginkgo biloba leaf aqueous extract was optimized by response surface methodology to yield monodispersed, crystalline nanoparticles of 18 ± 4 nm diameter. Fourier transform infrared spectroscopy confirmed capping by flavonoids, terpenoids and polyphenols providing stability for over 6 months. The biosynthesized AuNPs exhibited promising in vitro dose and time-dependent antiproliferative effects against human nasopharyngeal carcinoma CNE1 cells with IC50 reducing from 65.7 to 39.2 μg/mL over 24–72 hrs. Distinct cytoplasmic damage was observed under microscope. Treatment with 50 μg/mL AuNPs for 48 hrs dramatically upregulated pro-apoptotic Bax, Caspase-3 and p53 by 8.7, 6.5 and 4.3 fold respectively while downregulating anti-apoptotic Bcl-2 by 11.2 fold, indicating apoptosis induction via mitochondrial intrinsic pathway. The green fabricated G. biloba AuNPs displayed preferential toxicity towards carcinoma cells compared to normal fibroblasts, indicating potential for targeted nasopharyngeal cancer therapy.

Detection of cytotoxic effects of carboplatin in human nasopharyngeal carcinoma epithelioid cell line CNE-1 by Raman spectroscopy combined with multivariate statistical analysis

Raman spectroscopy combined with multivariate analysis was used to examine the molecular mechanism of carboplatin toxicity in human nasopharyngeal carcinoma epithelioid cell line CNE-1. Multivariate analysis was performed through principal component analysis combined with linear discriminant analysis, through which a diagnostic algorithm that could discriminate between the control and treatment groups was generated. Compared with the control group (0 μmol/L, 0 hour), the 2 protein Raman peaks (1002 cm−1 and 1659 cm−1) and the 2 deoxyribonucleic acid Raman peaks (1303 cm−1 and 1338 cm−1) in the treatment group decreased with increasing carboplatin concentrations as well as with increasing treatment durations. Using principal component analysis combined with linear discriminant analysis, the discrimination accuracy, sensitivity, and specificity between the control group and the cell groups treated at 12 and 16 μmol/L carboplatin for 24 hours were all 100%, suggesting that 16 μmol/L is suitable as the therapeutic dosing. Using the same method, the discrimination accuracy, sensitivity, and specificity between the control group and the cell groups that were treated with 12 μmol/L carboplatin for 24 and 36 hours were all 100%, indicating that 24 hours could be suitable treatment duration. These results suggest that Raman spectroscopy combined with multivariate statistical analysis could be a useful tool for assessing carboplatin-induced cytotoxicity in human nasopharyngeal carcinoma cells.

Rapid intracellular pH measurement based on electroporation- surface-enhanced Raman scattering

In this study, electroporation-surface-enhanced Raman scattering (SERS) was applied to rapidly measure intracellular pH. The generation of a sensitive SERS probe for measuring pH in the range of 6.0–8.0 was accomplished through the conjugation of the pH-sensitive molecule 4-mercaptobenzoic acid (4-MBA) to the surface of gold nanoparticles (Au NPs) through its thiol functional group. This bioprobe was then rapidly introduced into nasopharyngeal carcinoma CNE-1 cells by electroporation, followed by SERS scanning and the fitting of intensity ratios of each detection point’s Raman peaks at 1423 cm−1 and 1072 cm−1, to create the pH distribution map of CNE-1 cells. The electroporation-SERS assay introduces pH bioprobes into a living cell in a very short time and disperses the nanoprobe throughout the cytoplasm, ultimately enabling rapid and comprehensive pH analysis of the entire cell. Our work demonstrates the potential of electroporation-SERS for the biochemical analysis of live cells.

Analysis of cases of cervical cystic lymph node metastasis with an unknown primary misdiagnosed as branchial cleft carcinoma

Objectives: To analyze the location, discovery time and possible causes of cases of cervical cystic lymph node metastasis with an unknown primary misdiagnosed as branchial cleft carcinoma. Methods: A retrospective analysis was performed on clinical and pathological data of 15 patients misdiagnosed as branchiogenic carcinoma at Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College between January 2000 and December 2020. Results: Among the 15 patients, 6 were nasopharyngeal squamous cell carcinoma, 4 tonsil squamous cell carcinoma, 2 tongue root squamous cell carcinoma, 2 hypopharyngeal squamous cell carcinoma and 1 thyroid papillary carcinoma. The median time from the diagnosis of branchial cleft carcinoma to the discovery of primary lesions was 3.58 months (0-76 months). The causes of misdiagnosis might be the lack of experience in the diagnosis and treatment of branchial cleft carcinoma, and not enough attention to comprehensive examination and close follow-up. Conclusions: Different from oropharyngeal cancer reported internationally, the proportion of misdiagnosed cases with nasopharyngeal carcinoma as the primary site in the current article is higher. As a country with a high incidence of nasopharyngeal carcinoma, the examination of nasopharynx should not be taken lightly. Most hidden cases can be found in the comprehensive examination in a short time, while a few cases need long-term follow-up. Finding the primary sites should not rely too much on imaging examination, and we cannot ignore the importance of clinical physical examination.

Nasopharyngeal carcinoma cell screening based on nuclear targeting Surface-Enhanced Raman Scattering (SERS) detection

BackgroundNasopharyngeal carcinoma (NPC) is a malignant epithelial carcinoma arising from the nasopharyngeal mucosal lining. Diagnosis of NPC at early stage can improve the outcome of patients and facilitate reduction in cancer mortality. The most significant change between cancer cells and normal cells is the variation of cell nucleus. Therefore, accurately detecting the biochemical changes in nucleus between cancer cells and normal cells has great potential to explore diagnostic molecular markers for NPC. Highly sensitive surface-enhanced Raman scattering (SERS) could reflect the biochemical changes in the process of cell cancerization at the molecular level. However, rapid nuclear targeting SERS detection remains a challenge. ResultsA novel and accurate nuclear-targeting SERS detection method based on electroporation was proposed. With the assistance of electric pulses, nuclear-targeting nanoprobes were rapidly introduced into different NPC cells (including CNE1, CNE2, C666 cell lines) and normal nasopharyngeal epithelial cells (NP69 cell line), respectively. Under the action of nuclear localization signaling peptides (NLS), the nanoprobes entering cells were located to the nucleus, providing high-quality nuclear SERS signals. Hematoxylin and eosin (H&E) staining and in situ cell SERS imaging confirmed the excellent nuclear targeting performance of the nanoprobes developed in this study. The comparison of SERS signals indicated that there were subtle differences in the biochemical components between NPC cells and normal nasopharyngeal cells. Furthermore, SERS spectra combined with principal component analysis (PCA) and linear discriminant analysis (LDA) were employed to diagnose and distinguish NPC cell samples, and high sensitivity, specificity, and accuracy were obtained in the screening of NPC cells from normal nasopharyngeal epithelial cells. SignificanceTo the best of our knowledge, this is the first study that employing nuclear-targeting SERS testing to screen nasopharyngeal carcinoma cells. Based on the electroporation technology, nanoprobes can be rapidly introduced into living cells for intracellular biochemical detection. Nuclear-targeting SERS detection can analyze the biochemical changes in the nucleus of cancer cells at the molecular level, which has great potential for early cancer screening and cytotoxicity analysis of anticancer drugs.

Nasopharyngeal carcinoma with non-squamous phenotype may be a variant of nasopharyngeal squamous cell carcinoma after inhibition of EGFR/PI3K/AKT/mTOR pathway.

Nasopharyngeal carcinoma (NPC) is a cancerous tumor that develops in the nasopharynx epithelium and typically has squamous differentiation. The squamous phenotype is evident in immunohistochemistry, with diffuse nuclear positivity for p63 and p40. Nonetheless, a few NPCs have been identified by clinicopathological diagnosis that do not exhibit the squamous phenotype; these NPCs are currently referred to as non-squamous immunophenotype nasopharyngeal carcinomas (NSNPCs). In a previous work, we have revealed similarities between the histological appearance, etiology, and gene alterations of NSNPC and conventional NPC. According to ultrastructural findings, NSNPC still falls under the category of non-keratinized squamous cell carcinoma that is undifferentiated. NSNPC has an excellent prognosis and a low level of malignancy, according to a retrospective investigation. Based on prior research, we investigated the molecular mechanism of NSNPC not expressing the squamous phenotype and its biological behavior. IHC was used to determine the expression of EGFR, PI3K, AKT, p-AKT, mTOR, p-mTOR, Notch, STAT3 and p-STAT3 in a total of 20 NSNPC tissue samples and 20 classic NPC tissue samples. We obtained human NPC cell lines (CNE-2,5-8F) and used EGFR overexpression plasmid and shRNAs to transfect them. To find out whether mRNA and proteins were expressed in the cells, we used Western blotting and qRT-PCR. Cell biological behavior was discovered using the CCK-8 assay, cell migration assay, and cell invasion assay. EGFR, PI3K, p-AKT and p-mTOR proteins were lowly expressed in NSNPC tissues by immunohistochemistry, compared with classical NPC. In the classical NPC cell lines CNE-2 and 5-8F, overexpression EGFR can up-regulate the expression of p63 through the PI3K/AKT/mTOR pathway, and promote the proliferation, migration, and invasion of nasopharyngeal carcinoma cells. At the same time, knockout of EGFR can down-regulate p63 expression through the PI3K/AKT/mTOR pathway, and inhibit the proliferation, migration, and invasion of nasopharyngeal carcinoma cells. The lack of p63 expression in NSNPC was linked with the inhibition of the EGFR/PI3K/AKT/mTOR pathway, and NSNPC may be a variant of classical NPC.

Evaluation of Integrated SARS-CoV-2 Genome Presence in PBMC, Oropharyngeal, and Nasopharyngeal Samples of COVID-19 Patients

Background: Persistent detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in individuals who have recovered from coronavirus disease 2019 (COVID-19) remains an unexplained phenomenon warranting further study. Recent research suggests that this RNA could be the result of transcription from an integrated SARS-CoV-2 genome. Objectives: This study aimed to investigate the presence of the DNA form of the SARS-CoV-2 genome in oropharyngeal, nasopharyngeal, and peripheral blood mononuclear cell (PBMC) samples from COVID-19 patients with prolonged viral detection. Methods: We examined the presence of the reverse-transcribed viral genome in samples from eighty COVID-19 patients, including 40 outpatients (group 1), 40 hospitalized patients (group 2), and 40 healthy individuals (group 3), using a TaqMan® based real-time RT-PCR assay. Results: The mean ages of groups 1, 2, and 3 were 36.1 ± 11.0, 61.6 ± 18.4, and 39.0 ± 8.7, respectively. The molecular tests did not detect viral DNA forms, which may be produced during the SARS-CoV-2 life cycle, in the examined samples. Conclusions: Although no evidence of integrated viral DNA was found in this study, further research is essential to confirm these findings and explore the underlying mechanisms of prolonged SARS-CoV-2 RNA presence in recovered COVID-19 patients.

Prevalence and antibiotic susceptibility pattern of Streptococcus pneumoniae amongst residents of Obong Ntak in Etim Ekpo Local Government of Akwa Ibom State, Nigeria

Streptococcus pneumonia is among the major causative agents of respiratory tract infections and colonizes the nasopharyngeal cells of asymptomatically healthy individuals. Prevalence and antibiotics sensitivity of Streptococcus pneumonia amongst residents in a rural setting was evaluated. A total of 250 nasal swab samples (125 males and 125 females) were collected using sterile swab sticks. Administration of open-ended questionnaires, culture of the samples, identification of isolates, antimicrobial sensitivity test and determination of prevalence rate were all done using standard protocols. Out of the 250 samples collected, 35 were positive for S. pneumonia giving an overall prevalence of 14%. Based on sex, the prevalence rates were 15% and 20% for males and females, respectively. Prevalence rates of 12.5%, 13.7%, 12.7% and 25% were recorded for age groups of 10-20, 21-40, 41-60 and >60 years, respectively. The presence of S. pneumoniae based on the health status of the participants showed that the prevalence rates were 20% and 11.70% for clinically ill and clinically healthy individuals, respectively. The resistance profile to the test antibiotics were 22.9%, 22.9%, 11.4%, 100%, 100%, 34.3%, 34.3%, 100%, 54.3% and 77.1% respectively to perfloxacin, septrin, ciprofloxacin, amoxacilin, zinacef, gentamicin, erythromycin, ampliclox, streptomycin and rocephin. Ciprofloxacin was the most effective antibiotic followed by perfloxacin and septrin. Our isolates showed 100% multi-drug resistance and is a cause for concern.

195 epidemiological, clinical, and evolutionary features of nasopharyngeal squamous cell carcinoma

195 epidemiological, clinical, and evolutionary features of nasopharyngeal squamous cell carcinoma

Farm animal exposure, respiratory illnesses, and nasal cell gene expression

BackgroundFarm exposures in early life reduce the risks for childhood allergic diseases and asthma. There is less information about how farm exposures relate to respiratory illnesses and mucosal immune development. ObjectiveWe hypothesized that children raised in farm environments have a lower incidence of respiratory illnesses over the first two years of life than non-farm children. We also analyzed whether farm exposures or respiratory illnesses were related to patterns of nasal cell gene expression. MethodsThe Wisconsin Infant Study Cohort included farm (n=156) and non-farm (n=155) families with children followed to age 2 years. Parents reported prenatal farm and other environmental exposures. Illness frequency and severity were assessed using illness diaries and periodic surveys. Nasopharyngeal cell gene expression in a subset of 64 children at age two years was compared to farm exposure and respiratory illness history. ResultsFarm vs. non-farm children had nominally lower rates of respiratory illnesses (rate ratio 0.82 [0.69,0.97]) with a stepwise reduction in illness rates in children exposed to 0, 1, or ≥2 animal species, but these trends were non-significant in a multivariable model. Farm exposures and preceding respiratory illnesses were positively related to nasal cell gene signatures for mononuclear cells and innate and antimicrobial responses. ConclusionsMaternal and infant exposure to farms and farm animals was associated with nonsignificant trends for reduced respiratory illnesses. Nasal cell gene expression in a subset of children suggests that farm exposures and respiratory illnesses in early life are associated with distinct patterns of mucosal immune expression.

An amplicon-based protocol for whole-genome sequencing of human respiratory syncytial virus subgroup A.

It is convenient to study complete genome sequences of human respiratory syncytial virus (hRSV) for ongoing genomic characterization and identification of highly transmissible or pathogenic variants. Whole genome sequencing of hRSV has been challenging from respiratory tract specimens with low viral loads. Herein, we describe an amplicon-based protocol for whole genome sequencing of hRSV subgroup A validated with 24 isolates from nasopharyngeal swabs and infected cell cultures, which showed cycle threshold (Ct) values ranging from 10 to 31, as determined by quantitative reverse-transcription polymerase chain reaction. MinION nanopore generated 3200 to 5400 reads per sample to sequence over 93% of the hRSV-A genome. Coverage of each contig ranged from 130× to 200×. Samples with Ct values of 20.9, 25.2, 27.1, 27.7, 28.2, 28.8, and 29.6 led to the sequencing of over 99.0% of the virus genome, indicating high genome coverage even at high Ct values. This protocol enables the identification of hRSV subgroup A genotypes, as primers were designed to target highly conserved regions. Consequently, it holds potential for application in molecular epidemiology and surveillance of this hRSV subgroup.

Lipoteichoic Acids Are Essential for Pneumococcal Colonization and Membrane Integrity.

The hydrophilic, polymeric chain of the lipoteichoic acid (LTA) of the Gram-positive pathobiont Streptococcus pneumoniae is covalently linked to the glycosylglycerolipid α-<sc>d</sc>-glucopyranosyl-(1,3)-diacylglycerol by the LTA ligase TacL, leading to its fixation in the cytoplasmic membrane. Pneumococcal LTA, sharing identical repeating units with the wall teichoic acids (WTA), is dispensable for normal growth but required for full virulence in invasive infections. Mutants deficient in TacL and complemented strains constructed were tested for their growth, resistance against oxidative stress, and susceptibility against antimicrobial peptides. Further, the membrane fluidity of pneumococci, their capability to adhere to lung epithelial cells, and virulence in a Galleria mellonella as well as intranasal mouse infection model were assessed. In the present study, we indicate that LTA is already indispensable for pneumococcal adherence to human nasopharyngeal cells and colonization in an intranasal mouse infection model. Mutants deficient for TacL did not show morphological defects. However, our analysis of pneumococcal membranes in different serotypes showed an altered membrane fluidity and surface protein abundance of lipoproteins in mutants deficient for LTA but not WTA. These mutants had a decreased membrane fluidity, exhibited higher amounts of lipoproteins, and showed an increased susceptibility to antimicrobial peptides. In complemented mutant strains, this defect was fully restored. Taken together, LTA is crucial for colonization and required to effectively protect pneumococci from innate immune defence mechanisms by maintaining the membrane integrity.

Nasopharyngeal carcinoma cell screening based on the electroporation-SERS spectroscopy

Nasopharyngeal carcinoma (NPC) is a malignant tumor in head and neck. Early diagnosis can effectively improve the survival rate of patients. Nasopharyngeal exfoliative cytology, as a convenient and noninvasive auxiliary diagnostic method, is suitable for the population screening of NPC, but its diagnostic sensitivity is low. In this study, an electroporation-based SERS technique was proposed to detect and screen the clinical nasopharyngeal exfoliated cell samples. Firstly, nasopharyngeal swabs was used to collected the nasopharyngeal exfoliated cell samples from NPC patients (n = 54) and healthy volunteers (n = 60). Then, gold nanoparticles, as the Raman scattering enhancing substrates, were rapidly introduced into cells by electroporation technique for surface-enhanced Raman scattering (SERS) detection. Finally, SERS spectra combined with principal component analysis (PCA) and linear discriminant analysis (LDA) were employed to diagnose and distinguish NPC cell samples. Raman peak assignments combined with spectral differences reflected the biochemical changes associated with NPC, including nucleic acid, amino acid and carbohydrates. Based on the PCA-LDA approach, the sensitivity, specificity and accuracy of 98.15 %, 96.67 % and 97.37 %, respectively, were achieved for screening NPC. This study offers valuable assistance for noninvasive NPC auxiliary diagnosis, and has grate potential in expanding the application of the SERS technique in clinical cell sample testing.

NAD(P)H:quinone Oxidoreductase 1 Is Involved in AZ-1-induced Apoptotic Effects in Nasopharyngeal Carcinoma TW01 Cells.

Current NPC treatment methods have improved the 5-year survival rates of patients; however, some patients do not benefit from the treatments. Therefore, the existing treatment methods or new drugs must be developed to improve the patient's prognosis. NAD (P)H:quinone oxidoreductase 1 (NQO1), an electron reductase highly expressed in various cancers, can convert aziridinyl-substituted quinone-derived compound into an alkylating agent, resulting in cell apoptosis. Therefore, a di-aziridinyl-substituted quinone-derived compound, AZ-1, was designed previously. The present study investigated whether AZ-1 has anticancer activities in NPC cells and explored the underlying mechanism. NPC-TW01 cells were used in the study, and 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide, colony formation, terminal deoxynucleotidyl transferase dUTP nick end labeling, and immunoblotting assays were performed to assess the cell viability, cell survival, DNA fragmentation, and protein expression, respectively. The results show that AZ-1 significantly inhibited the viability and survival of NPC-TW01 cells. AZ-1 also induced the expression of cleaved PARP, cleaved caspase-8, cleaved caspase-9, and cleaved caspase-3, and triggered DNA fragmentation in NPC-TW01 cells. In addition, AZ-1 induced γH2AX expression, a DNA damage marker, in NPC-TW01 cells. Treatment with dicoumarol, an NQO1 activity inhibitor, not only reversed AZ-1-induced cell viability inhibition but also decreased AZ-1-induced expression of γH2AX, cleaved caspase-8, cleaved caspase-9, and cleaved caspase-3. NQO1 reverses AZ-1-triggered cell viability inhibition, DNA damage, and apoptosis. The findings of this study may provide a basis for the possible clinical application of AZ-1 in the treatment of NPC to improve the prognosis of patients with NPC.

Peritumoral SPARC expression induced by exosomes from nasopharyngeal carcinoma infected Epstein-Barr virus: A poor prognostic marker.

Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC) cells have high metastatic potential. Recent research has revealed that the interaction of between tumor cells and the surrounding stroma plays an important role in tumor invasion and metastasis. In this study, we showed the prognostic value of expression of SPARC, an extracellular matrix protein with multiple cellular functions, in normal adjacent tissues (NAT) surrounding NPC. In the immunohistochemical analysis of 51 NPC biopsy specimens, SPARC expression levels were significantly elevated in the NAT of EBER (EBV-encoded small RNA)-positive NPC compared to that in the NAT of EBER-negative NPC. Moreover, increased SPARC expression in NAT was associated with a worsening of overall survival. The enrichment analysis of RNA-seq of publicly available NPC and NAT surrounding NPC data showed that high SPARC expression in NPC was associated with epithelial mesenchymal transition promotion, and there was a dynamic change in the gene expression profile associated with interference of cellular proliferation in NAT, including SPARC expression. Furthermore, EBV-positive NPC cells induce SPARC expression in normal nasopharyngeal cells via exosomes. Induction of SPARC in cancer-surrounding NAT cells reduced intercellular adhesion in normal nasopharyngeal structures and promoted cell competition between cancer cells and normal epithelial cells. These results suggest that epithelial cells loosen their own binding with the extracellular matrix as well as stromal cells, facilitating the invasion of tumor cells into the adjacent stroma by activating cell competition. Our findings reveal a new mechanism by which EBV creates a pro-metastatic microenvironment by upregulating SPARC expression in NPC.

Brief research report: OM-85 reduces SARS-COV-2 viral RNA expression in nasopharyngeal cells from COVID-19 patients

OM-85 is a bacterial lysate from common respiratory tract pathogens, with an excellent safety profile, widely used to prevent recurrent respiratory tract infections. Several studies have been reporting the immunomodulating properties and antiviral roles of OM-85. The COVID-19 pandemic, originating in 2019, has presented a significant global public health crisis. While effective vaccines have been developed, vaccination rates vary considerably, and numerous concerning viral variants continue to emerge. The challenge persists in creating early interventions to halt the progression of the disease to its severe stages. To examine the therapeutic effect of OM-85 after SARS-CoV-2 infection and compared to recombinant human (rhINF-β) we collected nasopharyngeal cells from COVID-19 patients. The cells were treated ex-vivo with OM-85 or hrINF-β and the response was analyzed after 24h for gene expression by real-time PCR. We found that OM-85 decreased the SARS-CoV-2 N1 gene expression and increased RIG-I (DDX58) in these cells. The expression of ACE2 was undetected in these samples. These data support the antiviral effect of OM-85 against SARS-CoV-2.

Nucleocapsid single point-mutation associated with drop-out on RT-PCR assay for SARS-CoV-2 detection

BackgroundSince its beginning, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has been a challenge for clinical and molecular diagnostics, because it has been caused by a novel viral agent. Whole-genome sequencing assisted in the characterization and classification of SARS-CoV-2, and it is an essential tool to genomic surveillance aiming to identify potentials hot spots that could impact on vaccine immune response and on virus diagnosis. We describe two cases of failure at the N2 target of the RT-PCR test Xpert® Xpress SARS-CoV-2.MethodsTotal nucleic acid from the Nasopharyngeal (NP) and oropharyngeal (OP) swab samples and cell supernatant isolates were obtained. RNA samples were submitted to random amplification. Raw sequencing data were subjected to sequence quality controls, removal of human contaminants by aligning against the HG19 reference genome, taxonomic identification of other pathogens and genome recovery through assembly and manual curation. RT-PCR test Xpert® Xpress SARS-CoV-2 was used for molecular diagnosis of SARS-CoV-2 infection, samples were tested in duplicates.ResultsWe identified 27 samples positive for SARS-CoV-2 with a nucleocapsid (N) gene drop out on Cepheid Xpert® Xpress SARS-CoV-2 assay. Sequencing of 2 of 27 samples revealed a single common mutation in the N gene C29197T, potentially involved in the failed detection of N target.ConclusionsThis study highlights the importance of genomic data to update molecular tests and vaccines.