Cervical nitric oxide release and persistence of high-risk human papillomavirus in women

High-risk human papillomavirus infection and cervical cytopathology: relationship with cervical nitric oxide levels

BACKGROUND

Nitric oxide (NO) may contribute to the persistence of high-risk human papillomavirus (hrHPV) infection, which has been linked to the development of premalignant lesions and cervical cancer. Our study aimed to examine the relationship between cervical NO metabolite (NOx) levels, hrHPV infection, and cytopathological findings. Additionally, we assessed cervical NOx levels as a biomarker for predicting hrHPV infection and epithelial atypia.

METHODS

The study involved 74 women who attended the Gynecology and Obstetrics outpatient clinics at Cairo University Hospitals between November 2021 and August 2022. Cervical samples were subjected to Pap testing, assessment of NOx levels by the Griess method, and detection of hrHPV DNA by real-time polymerase chain reaction.

RESULTS

High-risk HPV was detected in 37.8% of women. EA was found in 17.1% of cases, with a higher percentage among hrHPV-positive than negative cases (35.7% vs. 4.3%, p = 0.001). The most prevalent hrHPV genotype was HPV 16 (89.3%). The cervical NOx level in hrHPV-positive cases was significantly higher (37.4 µmol/mL, IQR: 34.5-45.8) compared to negative cases (2.3 µmol/mL, IQR: 1.2-9.8) (p = < 0.001). Patients with high-grade atypia showed significantly higher NOx levels (38.0 µmol/mL, IQR: 24.6-94.7) in comparison to NILM and low-grade atypia cases (5.0 µmol/mL, IQR: 1.6-33.3 and 34.5 µmol/mL, IQR: 11.7-61.7, respectively) (p = 0.006). Although the NOx levels among hrHPV-positive cases with low-grade atypia (40.4 µmol/mL, IQR: 33.3‒61.8) were higher than those with NILM (36.2 µmol/mL, IQR: 35.7‒44.0) and high-grade atypia (38.0 µmol/mL, IQR: 24.6‒94.7), the difference was not significant (p = 0.771). ROC curve analysis indicated that the cervical NOx cut-off values of > 23.61 µmol/mL and > 11.35 µmol/mL exhibited good diagnostic accuracy for the prediction of hrHPV infection and EA, respectively.

CONCLUSIONS

The high prevalence of hrHPV infection, particularly HPV 16, in our hospital warrants targeted treatment and comprehensive screening. Elevated cervical NOx levels are associated with hrHPV infection and high-grade atypia, suggesting their potential use as biomarkers for predicting the presence of hrHPV and abnormal cytological changes.

Regulation of pleiotropic physiological roles of nitric oxide signaling

Nitric Oxide (NO) is a highly diffusible, ubiquitous signaling molecule and a free radical that is naturally synthesized by our body. The pleiotropic effects of NO in biological systems are due to its reactivity with different molecules, such as molecular oxygen (O₂), superoxide anion, DNA, lipids, and proteins. There are several contradictory findings in the literature pertaining to its role in oncology. NO is a Janus-faced molecule shown to have both tumor promoting and tumoricidal effects, which depend on its concentration, duration of exposure, and location. A high concentration is shown to have cytotoxic effects by triggering apoptosis, and at a low concentration, NO promotes angiogenesis, metastasis, and tumor progression. Upregulated NO synthesis has been implicated as a causal factor in several pathophysiological conditions including cancer. This dichotomous effect makes it highly challenging to discover its true potential in cancer biology. Understanding the mechanisms by which NO acts in different cancers helps to develop NO based therapeutic strategies for cancer treatment. This review addresses the physiological role of this molecule, with a focus on its bimodal action in various types of cancers.

Chemoradiation therapy changes oral microbiome and metabolomic profiles in patients with oral cavity cancer and oropharyngeal cancer

BACKGROUND

Patients with oral cavity cancer (OCC) and oropharyngeal cancer (OPC) are often seen with locoregionally advanced disease requiring complex multimodality treatments. These treatments may have detrimental effects on the oral microbiome, which is critical to maintaining physiological balance and health.

METHODS

The effects of different OCC and OPC treatment types on the oral microbiome and metabolomic profiles for 24-month post-treatment in patients with OCC and OPC were investigated using 16S rRNA gene amplicon next-generation sequencing and gas chromatography-mass spectrometry (GC-MS), respectively.

RESULTS

Chemoradiation resulted in oral dysbiosis with specific depletion of genera which regulate the enterosalivary nitrate-nitrite-nitric oxide pathway. These data also correlate with the oral metabolomic profiles with nitric oxide-related precursor, modulator, or catalyst significantly downregulated in saliva samples from patients' postchemoradiation.

CONCLUSIONS

Together, we have shown that oral dysbiosis due to the effects of chemoradiation could potentially have an impact on OCC and OPC patient's quality of life post-treatment.

The role of TLRs in cervical cancer with HPV infection: a review

The main cause of cervical cancer is persistent infection with high-risk human papilloma virus (HR-HPV), but not all human papilloma virus (HPV) infections lead to cervical cancer. The key factors that determine the outcome of HPV infection remain poorly understood, and how the host immune system protects against HPV infection is unclear. Toll-like receptors (TLRs) are a group of pattern recognition receptors present in the cytoplasm and cell membrane, and can specifically recognize pathogen-associated molecular patterns. As the key molecules of innate and acquired immunity, TLRs not only play important roles in the immune defense against infectious diseases, but also are involved in the occurrence and development of a variety of malignant tumors. In cervical cancer caused by HR-HPV infection, TLRs have been found to regulate the local immune microenvironment. The role of TLRs in HR-HPV infection and HPV-induced cervical cancer and its relationship with HPV vaccine are reviewed in this article.

Involvement of the Toll-Like Receptor/Nitric Oxide Signaling Pathway in the Pathogenesis of Cervical Cancer Caused by High-Risk Human Papillomavirus Infection

Human papillomavirus (HPV) can activate Toll-like receptor (TLR)/nitric oxide (NO) signaling pathways; however, whether the TLR/NO pathway is involved in cervical cancer caused by high-risk HPV (HR-HPV) remains unclear. In this study, 43 HR-HPV-positive patients with cervical cancer (CC group), 39 HR-HPV-positive patients with a healthy cervix (HR-HPV group), and 33 HR-HPV-negative controls were recruited. NO concentration in cervical canal and expression of inducible NO synthase (iNOS) in cervical tissues were detected. Expressions of key TLR/NO pathway genes (TLR3/4/7/8, NF-κB p65, and iNOS) in cervical epithelial cells were detected by quantitative reverse transcription PCR. Expressions of TLR4, NF-κB p65, and iNOS in CaSki, HeLa, and C33a cells were determined by Western blot. NO concentration in cervical canal of CC group was significantly higher than in other groups (P < 0.05). Positive rates of iNOS in cervical tissues were 72.1%, 28.2%, and 3.1% in the CC group, HR-HPV group, and controls, respectively (P < 0.05). Levels of TLR3, TLR4, TLR7, TLR8, NF-κB p65, and iNOS in cervical epithelial cells were higher in CC group than in other groups (P < 0.05). Both mRNA and protein levels of TLR4, NF-κB p65, and iNOS were higher in HPV-positive HeLa and CaSki cells than in HPV-negative C33a cells (P < 0.05). Together, these results suggest that TLR/NO signaling pathway may be involved in pathogenesis of cervical cancer caused by HR-HPV.

Correlation of plasma nitrite/nitrate levels and inducible nitric oxide gene expression among women with cervical abnormalities and cancer

Cervical cancer is caused by infection with high risk human papillomavirus (HR-HPV). Inducible nitric oxide synthase (iNOS), a soluble factor involved in chronic inflammation, may modulate cervical cancer risk among HPV infected women. The aim of the study was to measure and correlate plasma nitrite/nitrate levels with tissue specific expression of iNOS mRNA among women with different grades of cervical lesions and cervical cancer. Tissue biopsy and plasma specimens were collected from 120 women with cervical neoplasia or cancer (ASCUS, LSIL, HSIL and invasive cancer) and 35 women without cervical abnormalities. Inducible nitric oxide synthase (iNOS) mRNA from biopsy and plasma nitrite/nitrate levels of the same study subjects were measured. Single nucleotide polymorphism (SNP) analysis was performed on the promoter region and Ser608Leu (rs2297518) in exon 16 of the iNOS gene. Differences in iNOS gene expression and plasma nitrite/nitrate levels were compared across disease stage using linear and logistic regression analysis. Compared to normal controls, women diagnosed with HSIL or invasive cancer had a significantly higher concentration of plasma nitrite/nitrate and a higher median fold-change in iNOS mRNA gene expression. Genotyping of the promoter region showed three different variations: A pentanucleotide repeat (CCTTT) n, -1026T > G (rs2779249) and a novel variant -1153T > A. These variants were associated with increased levels of plasma nitrite/nitrate across all disease stages. The higher expression of iNOS mRNA and plasma nitrite/nitrate among women with pre-cancerous lesions suggests a role for nitric oxide in the natural history of cervical cancer.

Cervical nitric oxide metabolite levels and clinical variables as predictive factors of high-grade cervical intraepithelial neoplasia

PURPOSE

To create a prediction model of high-grade cervical intraepithelial neoplasia (CIN) based on clinical variables and the cervical nitric oxide metabolite (NOx) levels of study participants.

METHODS

This comparative study included 694 women undergoing colposcopy due to abnormal pap smear results. On the basis of the cervical biopsy results, the women were divided into the ≤ CIN 1 or CIN 2-3 group. The two groups were compared in terms of cervical NOx levels and clinical variables. Univariate, multivariate, and receiver-operating characteristic curve analysis were performed.

RESULTS

Multivariate analysis showed that CIN 2-3 associated with more than two cervical biopsies [odds ratio (OR) = 5.16], high-grade squamous intraepithelial lesion cytology (OR = 16.19), condom non-use (OR = 4.28), cervical NOx levels ≤ 99.9 μmol/L (OR = 16.62), more than four lifetime male sexual partners (OR = 10.56), and age at first coitus of ≤ 15 years old (OR = 3.54). This combined model had a sensitivity of 86.49 %, a specificity of 90.74 %, a positive predictive value of 64.0 %, and a negative predictive value of 97.2 %.

CONCLUSIONS

In the present sample, high-grade CIN associated with decreased cervical NOx levels. Thus, along with some clinical variables, cervical NOx levels may be an additional marker of cervical dysplasia.

High-risk human papillomavirus-induced expression of endothelial and inducible nitric oxide synthase in human uterine cervix

INTRODUCTION

Levels of nitric oxide metabolites are elevated in the cervical fluid of women with high-risk human papillomavirus (hrHPV). To elucidate the origin of this elevation we studied the cervical expression and localization of endothelial and inducible nitric oxide synthases (eNOS, iNOS) in women.

MATERIAL AND METHODS

Expression of eNOS and iNOS was studied by Western blotting in the uterine cervixes of 86 women with (n = 41) and without (n = 45) hrHPV infection. The localization of eNOS and iNOS in cervical cells was studied by immunohistochemistry in 32 randomly selected women.

RESULTS

Expression of eNOS and iNOS (in mean [95% CI] density units relative to actin) was higher in women with hrHPV versus those without (eNOS: 33.8 [22.5-45.1] versus 20.2 [6.1-34.3], P = 0.007; iNOS: 12.0 [7.1-16.9]) versus 5.6 [2.0-9.2], P = 0.003). Smoking reduced 64% eNOS (P = 0.001) and 68% iNOS (P = 0.008) in women with hrHPV. Endothelial NOS was localized in the vascular endothelium, while iNOS was present in basal squamous epithelial cells. Low-grade histological lesions were accompanied by elevated expression of both eNOS and iNOS.

CONCLUSIONS

High-risk HPV-associated elevation in cervical fluid nitric oxide metabolites results from both eNOS and iNOS stimulation. However, smoking seems to suppress this stimulation in hrHPV-infected women.