Characterization of Toll-like receptor transcriptome in squamous cell carcinoma of cervix: A case-control study

The HPV viral regulatory mechanism of TLRs and the related treatments for HPV-associated cancers

Infection with human papillomavirus (HPV) typically leads to cervical cancer, skin related cancers and many other tumors. HPV is mainly responsible for evading immune tumor monitoring in HPV related cancers. Toll like receptors (TLRs) are particular pattern recognition molecules. When the body is facing immune danger, it can lead to innate and direct adaptive immunity. TLR plays an important role in initiating antiviral immune responses. HPV can affect the expression level of TLR and interfere with TLR related signaling pathways, resulting in sustained viral infection and even carcinogenesis. This paper introduces the HPV virus and HPV related cancers. We discussed the present comprehension of TLR, its expression and signaling, as well as its role in HPV infection. We also provided a detailed introduction to immunotherapy methods for HPV related diseases based on TLR agonists. This will provide insights into methods that support the therapeutic method of HPV related conditions with TLR agonists.

Lactobacillus gasseri LGV03 isolated from the cervico-vagina of HPV-cleared women modulates epithelial innate immune responses and suppresses the growth of HPV-positive human cervical cancer cells

Persistent human papillomavirus (HPV) infections is necessary for the development of cervical cancers. An increasing number of retrospective studies have found the depletion of Lactobacillus microbiota in the cervico-vagina facilitate HPV infection and might be involved in viral persistence and cancer development. However, there have been no reports confirming the immunomodulatory effects of Lactobacillus microbiota isolated from cervico-vaginal samples of HPV clearance in women. Using cervico-vaginal samples from HPV persistent infection and clearance in women, this study investigated the local immune properties in cervical mucosa. As expected, type I interferons, such as IFN-α and IFN-β, and TLR3 globally downregulated in HPV+ persistence group. Luminex cytokine/chemokine panel analysis revealed that L. jannaschii LJV03, L. vaginalis LVV03, L. reuteri LRV03, and L. gasseri LGV03 isolated from cervicovaginal samples of HPV clearance in women altered the host's epithelial immune response, particularly L. gasseri LGV03. Furthermore, L. gasseri LGV03 enhanced the poly (I:C)-induced production of IFN by modulating the IRF3 pathway and attenuating poly (I:C)-induced production of proinflammatory mediators by regulating the NF-κB pathway in Ect1/E6E7 cells, indicating that L. gasseri LGV03 keeps the innate system alert to potential pathogens and reduces the inflammatory effects during persistent pathogen infection. L. gasseri LGV03 also markedly inhibited the proliferation of Ect1/E6E7 cells in a zebrafish xenograft model, which may be attributed to an increased immune response mediated by L. gasseri LGV03.

Design and optimisation of a small-molecule TLR2/4 antagonist for anti-tumour therapy

In anti-tumour therapy, the toll-like receptor 2/4 (TLR2/4) signalling pathway has been a double-edged sword. TLR2/4 agonists are commonly considered adjuvants for immune stimulation, whereas TLR2/4 antagonists demonstrate more feasibility for anti-tumour therapy under specific chronic inflammatory situations. In individuals with cancer retaliatory proliferation and metastasis after surgery, blocking the TLR2/4 signalling pathway may produce favourable prognosis for patients. Therefore, here, we developed a small-molecule co-inhibitor that targets the TLR2/4 signalling pathway. After high-throughput screening of a compound library containing 14 400 small molecules, followed by hit-to-lead structural optimisation, we finally obtained the compound TX-33, which has effective inhibitory properties against the TLR2/4 signalling pathways. This compound was found to significantly inhibit multiple pro-inflammatory cytokines released by RAW264.7 cells. This was followed by TX-33 demonstrating promising efficacy in subsequent anti-tumour experiments. The current results provide a novel understanding of the role of TLR2/4 in cancer and a novel strategy for anti-tumour therapy.

Expression of p16, p53, and TLR9 in HPV-Associated Head and Neck Squamous Cell Carcinoma: Clinicopathological Correlations and Potential Prognostic Significance

Purpose

To investigate the association of human papillomavirus (HPV) status with p16, p53, and TLR9 expression in head and neck squamous cell carcinoma (HNSCC) and to evaluate these proteins as potential surrogate prognostic markers.

Methods

Expression of p16, p53, and TLR9 was assessed by immunohistochemistry, and HPV status was analyzed by in situ hybridization in 85 tumors of patients with HNSCC. Chi-square test was performed to evaluate the correlations of HPV infection with p16, p53, and TLR9 expression. Kaplan–Meier method and Cox regression analyses were applied to evaluate the associations between the expression levels of these proteins and patient outcomes.

Results

Overall, 24 of the 85 HNSCC specimens were associated with HPV infection. High expression of p16, p53, and TLR9 in tumor cells was observed in 31.76%, 61.18%, and 49.41% of the specimens, respectively. p16 showed a higher diagnostic odds ratio for the prediction of HPV DNA positivity than p53 and TLR9. Improved 5-year overall and disease-free survival correlated with HPV positivity and high p16, low p53, and low TLR9 expression. Associations with improved outcomes were also observed for marker combinations high p16/low p53 and high p16/low p53/low TLR9. In a multivariate analysis, the high p16/low p53 signature showed the lowest hazard ratio regarding death.

Conclusion

The expression of p16, p53, and TLR9 in HNSCC is associated with HPV status. High p53 and TLR9 expression may be related to poor outcomes. The two-marker signature high p16/low p53 in tumor cells is a reliable tool for patient survival prognostication in HNSCC.

The role of Toll-like receptors (TLRs) in virus-related cancers: a mini review

The modulation of the host innate immune system is a well-established carcinogenesis feature of several tumors, including human Epstein-Barr (EBV) and Papillomavirus-(HPV) related cancers. These viruses are able to interrupt the initial events of the immune response, including the expression of Toll-like receptors (TLRs), cytokines, and inflammation. The aim of the study is to review current data and summarize knowledge on the TLRs and their role in the development of cancer, especially viral-related cancers (EBV and HPV). Research work shows a correlation between the TLRs polymorphism and the development of oropharyngeal and gastric cancer (GC), especially related to viral infections. Many studies suggest the important role for TLRs in inflammatory, autoimmune disease and human cancers. However, further efforts are necessary to draw a precise conclusion.

Understanding HLA-G driven journey from HPV infection to cancer cervix: Adding missing pieces to the jigsaw puzzle

Human Papillomavirus (HPV) is a vital risk-factor for cancer cervix. However, persistent HPV infection results in cervical cancer in only a minority. Probably, HPV subdues the host immune response for persistence, which includes augmentation of HLA-G and plausibly aids in progression to cervical cancer. HLA-G, which comprises of membrane and soluble form, downregulates the host's immune response and generate tolerance. The current study aimed to analyze both forms of HLA-G in fresh tissue and plasma of women with HPV-infected and uninfected cervix and cancer cervix using Western blot and ELISA. The study cohort included 30 women with cervical carcinoma and equal number with normal cervix and 6 with HPV infected cervix. We observed a significant upregulation of membranous HLA-G expression in HPV infected cervix and cervical carcinoma (P < 0.001). Interestingly, the pairwise comparison of HLA-G tissue protein expression of the normal cervix and cervical carcinoma, as well as the normal cervix with HPV infected cervix, was significant (P < 0.001). Levels of soluble HLA-G were significantly raised in carcinoma cervix. We observed a progressive increase in HLA-G protein expression in HPV infected cervix and cervical carcinoma. These findings compel us to hypothesize that the upregulation of HLA-G expression favors the persistence of HPV in a microenvironment of a submissive host response. This progressive upregulation further leads to cervical cancer. Thus elimination of HPV infection seems to be a desirable proposition to prevent cervical cancer. In the absence of antiviral therapy for HPV, exploration of HLA-G antibody-based therapeutic strategies appear promising.

HPV Induces Changes in Innate Immune and Adhesion Molecule Markers in Cervical Mucosa With Potential Impact on HIV Infection

While most HPV infections are asymptomatic and clear spontaneously, persistent infection with high-risk HPVs is associated with cervical cancer and with increased risk of HIV acquisition. Although several hypotheses have been proposed to explain this phenomenon, none has been confirmed. Our aim was to investigate the expression of host factors involved in the susceptibility to HIV infection among HPV-infected women. Cervical samples were collected to characterize the expression levels of HIV susceptibility markers in the mucosa of HPV-infected compared with HPV-uninfected women. No differences in the frequency of CCR5+, integrin α4β7+, activated and memory CD4+ T-cell were detected between the groups. We additionally evaluated the expression levels of genes involved in innate immune responses and in cell adhesion. HPV infected patients expressed higher levels of TLR9 and lower levels of pattern recognition receptors that recognize RNA (TLR3, TLR7, and MDA5/IFIH1). We also detected an impaired IFN pathway, with an increased Type I IFN and a decreased IFNα2 receptor expression. HPV+ samples displayed reduced expression of genes for adherens and tight junctions. Taken together, these results suggest that although HPV infection does not result in the recruitment/activation of susceptible CD4+ T-cell in the female genital tract, it leads to changes in the innate antiviral immune responses and in cell adhesion that are likely to favor HIV infection.

Polymorphisms and haplotypes of TLR4, TLR9 and CYP1A1 genes possibly interfere with high-risk human papillomavirus infection and cervical cancer susceptibility in Jharkhand, India

BACKGROUND

Expression and single nucleotide polymorphisms (SNPs) of TLR4/9 and CYP1A1 genes are vital for cervical squamous cell carcinoma (CSCC) but considerably vary in different populations.

METHODS

A total of 255-subjects from Jharkhand (130-cases, 125-controls) were utilized to obtain the expression/SNP status of TLR4/9, CYP1A1, and E6 (HPV16/18) by RT-PCR, WB, and allele-specific-PCR followed by sequencing.

RESULTS

Over-expression of TLR4/9 and high infection of HPV16/18(78.5%) were found to be associated with CSCC. Among the seven SNPs(p1-p7) tested, the CT-genotype (p3:rs1927911; OR = 2.142; p = 0.004) and 'T'-allele (p3; OR = 1.694; p = 0.0061) of TLR4; CC-genotype (p4:rs5743836; OR = 3.307; p = 0.0018), 'C'-allele (p4; OR = 1.895; p = 0.0009), GA-genotype (p5:rs352140; OR = 2.064; p = 0.0172), AA-genotype (p5; OR = 2.602; p = 0.0021) and 'A'-allele (p5; OR = 1.939; p = 0.0002) of TLR9; and the TC-genotype (p6:rs4646903; OR = 1.967; p = 0.0452) and GG-genotype (p7:rs1048943; OR = 2.336; p = 0.0287) and 'G'-allele (p7; OR = 1.685; p = 0.0082) of CYP1A1 were associated with an increased-risk of CSCC. Similarly, the p3:CT-genotype (OR = 1.993; p = 0.0134); p4:CC-genotype (OR = 3.071; p = 0.0057) and 'C'-allele (OR = 1.838; p = 0.0029); p5:AA-genotype (OR = 2.231; p = 0.0147) and 'A'-allele (OR = 1.756; p = 0.0032); p6:TC-genotype (OR = 2.370; p = 0.02); and the p7:GG-genotype (OR = 2.255; p = 0.0488) and 'G'-allele (OR = 1.691; p = 0.0118) showed an association with HPV16/18 infection. Conversely, TLR4 (p1-p2-p3:A-G-T; OR = 3.361; p = 0.029), TLR9 (p4-p5:C-A; OR = 1.786; p = 0.032) and CYP1A1 (p6-p7:C-G; OR = 1.783; p = 0.033) haplotypes with CSCC susceptibility was observed, whereas the TLR4 (p1-p2-p3:A-C-C; OR = 0.4675; p = 8.E-3) and TLR9 (p4-p5:T-G; OR = 0.3937; p = 0.00) haplotypes showed protection against the development of CSCC. Further, though p1:rs10759931 and p2:rs11536889 were found to be insignificant, the p3:CT-genotype, p5:GA/AA-genotype, and p7:GG-genotype were associated with elevated protein; the p4:CC-genotype and p6:TC-genotype were associated with increased mRNA compared to their respective-wild-type-groups.

CONCLUSION

The present study revealed an association between TLR4/9 and CYP1A1 polymorphisms with increased HPV16/18 infection susceptibility and CSCC risk among the women of Jharkhand state.

The role of Toll-like receptor 4 signaling pathway in ovarian, cervical, and endometrial cancers

Toll-like receptors (TLRs) are critical sensors related to inflammation and tumorigenesis. Among all subtypes, the TLR4 is a highly described transmembrane protein involved in the inflammatory process. The TLR4/myeloid differentiation factor 88 (MyD88) signaling pathway has been implicated in oncogenic events in several tissues and is associated with survival of patients. Through activation, TLR4 recruits adaptor proteins, i.e., MyD88 or TRIF, to triggers canonical and non-canonical signaling pathways that result in distinct immune responses. In most cancer cells, uncontrolled TLR4 signaling modifies the tumor microenvironment to proliferate and evade immune surveillance. By contrast, TLR4 activation can produce antitumor activities, thereby inhibiting tumor growth and enhancing the proper immune response. We review herein recent approaches on the role of the TLR4 signaling pathway and discuss potential candidates for gynecological cancer therapies; among these agents, natural and synthetic compounds have been tested both in vitro and in vivo. Since TLR4 ligands have been investigated as effective immune-adjuvants in the context of these aggressive malignancies, we described how TLR4 signaling controls part of the tumor-related inflammatory process and which are the new targeting molecules implicated in the regulation of tumorigenicity in ovarian, cervical, and endometrial cancers.

TLR4: An Important Molecule Participating in Either Anti-Human Papillomavirus Immune Responses or Development of Its Related Cancers

It has been reported that human papillomavirus (HPV) is a main cause of cervical cancer. Immune system plays key roles in the HPV infection clearance. Additionally, the roles played by immune responses in development of cancers have been documented previously. Toll-like receptors (TLRs) are the main surface or intravesicular receptors driving innate immunity, which either participate in the fight against infectious agents or participate in the progression of cancers. Thus, it has been hypothesized that the molecules may be part of the HPV/cancers puzzle. TLR4 is a unique member of TLRs family that uses both well-known TLRs related intracellular signaling pathways. Furthermore, the roles played by TLR4 against several viruses and also their related complications, such as tumors, have been demonstrated. Thus, it has been hypothesized that TLR4 may play a key role in HPV infection and its related complications. This review article collected the information regarding the mentioned plausible roles by TLR4.

Human papillomavirus 16 infection alters the Toll-like receptors and downstream signaling cascade: A plausible early event in cervical squamous cell carcinoma development

OBJECTIVE

Toll-like receptors constitute an important component of innate immune mechanism. HPV is a known etiological factor of cervical cancer and is known to interfere with the expression of TLRs and downstream signaling pathway. It remains poorly understood whether HPV modulates the expression of TLRs. Hence, understanding HPV mediated immune alterations might aid in identifying novel therapeutic targets. The aim was to study the relative gene expression of TLRs & downstream signaling pathway in cervical carcinoma.

METHODS

Cervical squamous cell carcinoma (CSCC) and normal cervical tissues were obtained. Subsequent to HPV genotyping, mRNA expression profiling using PCR Array was performed. Protein expression of relevant genes with western blot was studied. Levels of cytokines in cervicovaginal washes were estimated using a Luminex multiplex platform.

RESULTS

All cases of cervical cancer were HR-HPV positive and predominant subtype was HPV16 (71.1%). Significant TLR4 upregulation and TLR2,7 downregulation were observed in HR-HPV infected cervix. TLR4,7 demonstrated low expression in CSCC. Molecules from cancer allied pathways; RELA, AKT, CDKN2A, and MDM2 demonstrated upregulation in CSCC. Protein expression data corroborated with gene expression profile. A diminished level of Th1 cytokines TNF-α, IFN-ɣ, IL-17, and IL-12 was observed in CSCC. Significantly increased levels of IL-1β, IL-6 and IL-2 were detected in HR-HPV infected cervix. Kaplan Meier curve demonstrated high TLR4 and low TLR7 expression was associated with poor prognosis.

CONCLUSION

The study demonstrates the HPV mediated dampening of the innate immune response in CSCC and provides support for exploring potential TLR2, 7 agonists as an adjunct therapy in CSCC patients.

Therapeutic potential of toll-like receptors in treatment of gynecological cancers

Toll-like receptors (TLRs) play an important role in the innate and adaptive immune system. They are expressed in various regions of the female reproductive tract, and their regulation may be involved in the pathogenesis of gynecological lesions. There is growing evidence that ligands for several TLRs are potentially anticancer agents, some of which have already been approved by the FDA, and these compounds are now undergoing clinical evaluation. There is a rationale for using these ligands as adjuvants in the treatment or prevention of gynecological cancer. Some TLR agonists that are of potential interest in the treatment of gynecological lesions include imiquimod, motolimod, cervarix, and CpG-oligodeoxynucleotides (ODNs). In this review, we outline the different functions of TLRs in gynecological cancer with particular emphasis on the value of TLR agonists as a potential therapeutic target in the treatment of gynecological cancer. © 2019 IUBMB Life, 71(5):549-564, 2019.

Viral Modulation of TLRs and Cytokines and the Related Immunotherapies for HPV-Associated Cancers

The modulation of the host innate immune system is a well-established carcinogenesis feature of several tumors, including human papillomavirus- (HPV-) related cancers. This virus is able to interrupt the initial events of the immune response, including the expression of Toll-like receptors (TLRs), cytokines, and inflammation. Both TLRs and cytokines play a central role in HPV recognition, cell maturation and differentiation as well as immune signalling. Therefore, the imbalance of this sensitive control of the immune response is a key factor for developing immunotherapies, which strengthen the host immune system to accomplish an efficient defence against HPV and HPV-infected cells. Based on this, the review is aimed at exposing the HPV immune evasion mechanisms involving TLRs and cytokines and at discussing existing and potential immunotherapeutic TLR- and cytokine-related tools.

TLR9 gene polymorphism -1486T/C (rs187084) is associated with uterine cervical neoplasm in Mexican female population

PURPOSE

The aim of this work was to evaluate the association of single nucleotide polymorphisms in TLR9 (-1486 T/C [rs187084], -1237T/C [rs5743836] and G2848A [rs352140]) with HPV infection, squamous intraepithelial lesions, and uterine cervical neoplasm in a Mexican population. Additionally, the peripheral expression of TLR9 was evaluated to evaluate the differences in the TLR9 expression associated with every genotype in the locus -1486 of the TLR9 gene. The serum concentration of TLR9 was evaluated in a randomly selected subsample.

METHODS

Genotyping was performed using predesigned 5' endonuc lease assays and the association of the polymorphisms with the diagnosis groups were assessed by performing multinomial regression models. The relative expression of TLR9 in peripheral blood mononuclear cells was evaluated by real-time polymerase chain reaction and the association of the level of TLR9 expression with the diagnosis was evaluated by performing multinomial regression models. The serum concentration of TLR9 was evaluated in a subsample of patients diagnosed with uterine cervical neoplasm by ELISA.

RESULTS

The results showed that genotype TT in the -1486 locus of TLR9 was significantly associated with HPV infection (OR = 3.25, 95% CI 1.12-9.46), squamous intraepithelial cervical lesion (OR = 3.76, 95% CI 1.36-10.41), and uterine cervical neoplasm (OR = 5.30, 95% CI 1.81-15.55). Moreover, the highest level of TLR9 expression was significantly associated with a greater risk for developing squamous intraepithelial cervical lesion and uterine cervical neoplasm. The serum TLR9 concentration was higher in patients with uterine cervical cancer than in controls.

CONCLUSION

Our findings indicate that genotype TT in the -1486 locus of the TLR9 gene could comprise a risk genotype for HPV infection, squamous intraepithelial cervical lesion, and uterine cervical neoplasm in Mexican female population. Further studies with larger samples are needed to evaluate if the peripheral expression of TLR9 could be used as a biomarker of uterine cervical neoplasm progression.

A study of the expression and localization of toll-like receptors 2 and 9 in different grades of cervical intraepithelial neoplasia and squamous cell carcinoma

TLRs are important molecules of innate immune response, those play central role in host pathogen interaction and recognition through pathogen associated molecular patterns (PAMPs). Previous studies have indicated the role of TLRs in many human malignancy and cervical cancer in terms of viral recognition and inflammatory changes in-vivo. The objective of this study was to evaluate the expression and localization of toll-like receptor (TLR) 2 and TLR9 in preinvasive and invasive cervical cancer patients and to investigate its use as a probable diagnostic tool for better management cervical cancer. This single institution study includes individuals with normal, precancerous lesions, cervical intraepithelial neoplastic (CIN) and invasive squamous cell carcinoma (SCC) of the cervix. Upon confirmation by histopathology, fluorescence based immunohistochemistry was performed in all patients for TLR2 and TLR9, followed by semi-quantitative estimation of the staining intensity and grade of expression. The expression pattern of TLR2 and TLR9 does not vary greatly from normal to precancerous lesions, but a significant variation was observed in advance stages, i.e. squamous cell carcinoma of the uterine cervix. Additionally the expression increased marginally in higher grades. In spite of their low difference in expression along different stages of cervical cancer, both TLR2 and TLR9 could detect the disease at an advance stages as depicted by the receiver operator characteristics curve analysis.