Low expression of nuclear Toll-like receptor 4 in laryngeal papillomas transforming into squamous cell carcinoma

TLR9 in the Human Papilloma Virus Infections: Friend or Foe?

Immune system plays dual roles during human papilloma virus (HPV) infections, from defense against the virus to induction or stimulation of the HPV-related cancers. It appears that various differences within the immune-related genes and the functions of the immunological parameters of the patients are the main factors responsible for the roles played by immune system during HPV infections. Toll-like receptors (TLRs) play key roles in the recognition of viruses and activation of immune responses. The molecules also can alter the target cell intracellular signaling and may participate in the transformation of the infected cells. TLR9 is the unique intracellular member of TLRs that recognize foreign DNA, including viral DNA. Thus, TLR9 may play significant roles in the defense against HPV and its related cancers. This review article discusses TLR9 antiviral and pathological roles during HPV infection.

Risk factors for the development of high-grade dysplasia and carcinoma in patients with laryngeal squamous cell papillomas: Large retrospective cohort study

BACKGROUND

The incidence and risk factors for the development of high-grade dysplasia (HG-D) and laryngeal squamous cell carcinoma (LSCC) were assessed in patients with laryngeal squamous cell papillomas (LSP).

METHODS

Clinical data, human papillomaviruses (HPV) typing, HPV E6/E7 mRNA in situ hybridization, and sequencing of host genes in LSP biopsies of 163 patients were analyzed.

RESULTS

Progression to HG-D and LSCC was identified in 21.5% and 4.3% of LSP patients, respectively. A more advanced age at LSP onset and lack of HPV infection were detected as risk factors for the development of HG-D and LSCC (P < .05). The identification of HG-D was associated with its progression to LSCC (P < .05). Host gene mutations were identified in 3 of 7 patients with LSCC.

CONCLUSIONS

The histological monitoring of LSP and HPV typing are necessary for early detection of epithelial changes. Further research is needed to elucidate the role of host gene mutations in LSCC transformation.

Abnormal Activation of Myeloid Dendritic Cells in JORRP Patients and Associated with Disease Activity

BACKGROUND

Representing the first line of host defense against virus infections and an essential link between innate and adaptive immune response, the role of dendritic cells (DCs) in peripheral blood of juvenile-onset recurrent respiratory papillomatosis (JORRP) patients and association with disease activity were still not established.

MATERIALS AND METHODS

In our present study, 28 JORRP patients and 28 age and sex matched healthy controls were enrolled. The percentage, phenotype and cytokine secretion of DC and was measured by flow cytometry. Plasma cytokine were detected by the enzyme-linked immunosorbent assay (ELISA).

RESULTS

We found that the percentage of myeloid DC (mDC) was significantly lower in JORRP patients compared to healthy controls and was negatively correlated with interval times, but not surgical times or disease onset. Moreover, the activation marker, CD40 and CD86 was significantly up-regulated on the surfaces of mDC in JORRP patients compared with healthy controls. Neither the percentage nor activation of plasmacytoid DC (pDC) showed statistical difference between JORRP patients and healthy controls. HLA-DR expression on both mDC and pDC was down-regulated in JORRP group and negatively correlated with surgical times. Antigen presenting ability of DC was greatly impaired in JORRP patients of higher number of operations and shorter interval time. Plasma IL-10 as well as IL-10 secreted by mDC was higher in JORRP patients compared with healthy control. Finally, we detected an up-regulated TLR2 and TLR4 expression on mDCs and TLR4 expression was positively correlated with HLA-DR expression on mDC of JORRP patients.

CONCLUSION

Our results demonstrate an abnormal TLR2 and TLR4 expression in mDCs may contribute to suppressive immune response to HPV6 or HPV11 infection and associated with disease activity in JORRP patients.

Expression of toll-like receptors in non-endemic nasopharyngeal carcinoma

Background

Nasopharyngeal carcinoma (NPC) is a malignant disease with an enigmatic etiology. NPC associates with Epstein-Barr virus (EBV) and human papillomaviruses (HPVs), while immunological factors also play a role in carcinogenesis. Toll-like receptors (TLRs) are pattern recognition receptors that participate in the immunological defence against pathogens, but their functions are also linked to cancer.

Methods

In our whole population-based study, we retrieved 150 Finnish NPC cases and studied their tumour samples for TLR1, TLR2, TLR4, TLR5, TLR7, and TLR9 expressions by immunohistochemistry, and for the presence of EBV and high-risk HPVs with EBV RNA and HPV E6/E7 mRNA in situ hybridizations. In addition, we analyzed the TLR expression patterns according to age, tumour histology, EBV/HPV status, and outcome.

Results

We found that all TLRs studied were highly expressed in NPC. Viral status of the tumours varied, and 62% of them were EBV-positive, 14% HPV-positive, and 24% virus-negative. The tumours with strong TLR2^nucl or TLR5 expression were mostly virus-negative or HPV-positive keratinizing squamous cell carcinomas, and the patients with these tumours were significantly older than those with mild or negative TLR2^nucl/TLR5 expression. In Kaplan-Meier analysis, the patients with strong TLR5 expression had worse survival compared to the patients with negative or mild TLR5 expression, but the results were linked to other patient and tumour characteristics. In multivariable-adjusted Cox regression analysis, the patients with positive TLR7 tumour expression had better overall survival than those with no TLR7 expression. The 5-year overall survival rates according to TLR7 expression were 66% (mild), 52% (moderate or strong), and 22% (negative).

Conclusions

TLRs are highly expressed in non-endemic NPC. Intensity of TLR2 and TLR5 expressions correlate with viral status, and TLR7 seems to be an independent prognostic factor of non-endemic NPC.

TLR4 Polymorphisms and Expression in Solid Cancers

Toll-like receptors (TLRs) are a type of pattern-recognition receptor (PRR) that are part of the innate immune system known to recognize pathogen-associated molecular patterns and thereby play a crucial role in host immune response. Among the various known TLRs, TLR4 is one of the most extensively studied PRRs expressed by immune, certain nonimmune, and tumor cells. When TLR4 binds with the bacterial lipopolysaccharide, it induces production of proinflammatory cytokines, chemokines, and effector molecules as part of the immune response. Continuous exposure to pathogens and TLR4 signaling results in chronic inflammation that may further lead to malignant transformation. TLR4 is a highly polymorphic gene, and genetic variations are known to influence host immune response, leading to dysregulation of signaling pathway, which may affect an individual's susceptibility to various diseases, including cancer. Furthermore, TLR4 expression in different tumor types may also serve as a marker for tumor proliferation, differentiation, metastasis, prognosis, and patient survival. This review aims to summarize various reports related to TLR4 polymorphisms and expression patterns and their influences on different cancer types with a special focus on solid tumors.

Squamous Cell Carcinoma Originating from Adult Laryngeal Papillomatosis: Case Report and Review of the Literature

Background

The malignant transformation of laryngeal papillomatosis (LP) into squamous cell carcinoma (SCC) can occur in up to 4% of LP cases. The low-risk HPV types 6 and 11 are those that are most commonly related to LP; however, high-risk HPV types may be present. The present study reviews the literature on cases of malignant transformation of LP in adults and reports a clinical case.

Case Report

A 47-year-old male patient exhibiting hoarseness for 4 months presented an exophytic lesion in the right palatine tonsil and a digitiform-like lesion in the right vocal fold. The biopsy revealed a well-differentiated SCC in the vocal cord, which showed a transition zone with a squamous papillomatous lesion. By using the chromogenic in situ hybridization (CISH) test, both lesions showed a positive result for high-risk HPV types 16 and 18 and negative for low-risk HPV types 6 and 11. The final diagnosis was SCC arising from LP. The patient underwent surgical treatment. After 36 months of follow-up, no signs of recurrence were observed.

Results

The literature review revealed 25 cases of malignant transformation into SCC of LP with adult onset. Of these, only 9 cases were assessed by CISH and/or PCR for HPV identification, of which 7 were positive. The current study focuses on the eighth case, suggesting the involvement of the high-risk HPV types in its pathogenesis.

Conclusions

LP is considered a benign lesion with the potential for malignant transformation, which reinforces the need for its early diagnosis and the constant monitoring of patients with LP.

Serum matrix metalloproteinase 8 and tissue inhibitor of metalloproteinase 1: Potential markers for malignant transformation of recurrent respiratory papillomatosis and for prognosis of laryngeal cancer

BACKGROUND

Biomarkers that could predict malignant transformation of recurrent respiratory papillomatosis (RRP) would be useful in patient follow-up. We investigated whether serum matrix metalloproteinase 8 (MMP-8) and tissue inhibitor of metalloproteinase 1 (TIMP-1) could predict malignant transformation of RRP and whether they associate with survival in laryngeal squamous cell carcinoma (LSCC) without preexisting RRP.

METHODS

We analyzed serum MMP-8 (S-MMP-8) and serum TIMP-1 (s-TIMP-1) in 114 patients: 55 were treated for RRP and 59 for LSCC without preexisting RRP. Five patients with RRP developed LSCC during follow-up.

RESULTS

Elevated S-MMP-8 level in RRP was associated with malignant transformation (P = .01). Compared to patients with RRP, S-MMP-8 in patients with LSCC was significantly higher (P < .001). Increased S-TIMP-1 level in LSCC was associated with poor overall survival (P = .02) and recurrence-free survival (P = .05).

CONCLUSION

In RRP, high S-MMP-8 may predict malignant transformation. In LSCC, elevated S-TIMP-1 is connected to poor survival.

Toll-like receptors 1, 2, 4 and 6 in esophageal epithelium, Barrett's esophagus, dysplasia and adenocarcinoma

Background

Toll-like receptors (TLRs) recognize microbial and endogenous ligands and have already shown to play a role in esophageal cancer. In this study, we evaluated especially TLRs that sense bacterial cell wall components in Barrett's esophagus, dysplasia and esophageal adenocarcinoma.

Methods

TLRs 1, 2, 4 and 6 were stained immunohistochemically and assessed in esophageal specimens from patients with esophageal dysplasia (n = 30) or adenocarcinoma (n = 99). Structures and lesions were evaluated including normal esophagus (n = 88), gastric (n = 67) or intestinal metaplasia (n = 51) without dysplasia, and low-grade (n = 42) or high-grade dysplasia (n = 37), and esophageal adenocarcinoma (n = 99).

Results

We found TLR1, TLR2, TLR4 and TLR6 expression in all lesions. TLR expression increased in Barrett's mucosa and dysplasia. There was profound increase of TLR expression from gastric- to intestinal-type columnar epithelium. In cancers, high nuclear and cytoplasmic staining of TLR4 associated with metastatic disease and poor prognosis.

Conclusions

TLR1, TLR2, TLR4 and TLR6 are upregulated during malignant changes of esophageal columnar epithelium. Increased TLR4 expression associates with advanced stage and poor prognosis in esophageal adenocarcinoma.

TLR4 as a negative regulator of keratinocyte proliferation

TLR4 is an innate immune receptor with expression in human skin, keratinocytes as well as squamous cell carcinoma (SCC) of the skin. In the present study we investigate the role of TLR4 as a negative regulator of keratinocyte proliferation. We present here that the expression of TLR4 increased with the differentiation of cultured keratinocytes in a passage-dependent manner or under calcium-rich conditions. Moreover, the down-regulation of TLR4 by specific knockdown increased the proliferation of HaCaT keratinocytes in vitro. In addition, subcutaneously injected HaCaT keratinocytes with shTLR4 formed growing tumors in nude mice. In contrast, we observed lower proliferation and increased migration in vitro of the SCC13 cell line stably overexpressing TLR4 in comparison to SCC13 TLR4 negative cells. In vivo, SCC13 TLR4-overexpressing tumors showed delayed growth in comparison to TLR4 negative tumors. The overexpression of TLR4 in SCC13 tumor cells was followed by phosphorylation of ERK1/2 and JNK and increased expression of ATF3. In gene expression arrays, the overexpression of TLR4 in tumor cells correlated with gene expression of ATF-3, IL-6, CDH13, CXCL-1 and TFPI. In summary, TLR4 negatively regulates the proliferation of keratinocytes and its overexpression reduces tumor growth of SCC cells.

The Expression of Toll-like Receptors in Normal Human and Murine Gastrointestinal Organs and the Effect of Microbiome and Cancer

Toll-like receptors (TLRs) are innate immune receptors expressed in all parts of the alimentary tract. However, analyses comparing expression in different segments and data on germ-free animals are lacking. Alimentary tract cancers show increased TLR expression. According to the field effect concept, carcinogenetic factors induce subtle cancer predisposing alterations in the whole organ. We studied TLR1 to TLR9 expression in all segments of the alimentary tract from cancer patients’ tumor-adjacent normal mucosa, healthy organ donors, and conventional and germ-free mice by using immunohistochemistry and quantitative PCR. All TLRs were expressed in all segments of the alimentary tract. Expression was most intensive in the small intestine in humans and conventional mice, but germ-free mice showed less expression in the small intestine. TLR expression levels were similar in cancer patients and organ donors. We provide systematic baseline data on the TLR expression in the alimentary tract. Normal epithelium adjacent to tumor seems to have similar TLR expression compared with healthy tissues suggesting absence of any field effect in TLR expression. Accordingly, specimens from cancer patients’ normal tumor-adjacent tissue can be used as control tissues in immunohistochemical TLR studies in gastrointestinal cancer.

Expression profile analysis of head and neck squamous cell carcinomas using data from The Cancer Genome Atlas

Head and neck squamous cell carcinoma (HNSCC) is the major histological type of head and neck cancer and no curative treatments are currently available. Using advanced sequencing technologies, The Cancer Genome Atlas (TCGA) has produced large-scale sequencing data, which provide unprecedented opportunities to reveal molecular mechanisms of cancer. The present study analyzed the mRNA and micro (mi)RNA expression data of HNSCC and normal control tissues released by the TCGA database using a bioinformatics approach to explore underlying molecular mechanisms. The mRNA and miRNA expression data were downloaded from the TCGA database and differentially expressed genes (DEGs) and miRNAs (DEMs) between HNSCC and normal head and neck tissues were identified using TwoClassDif. Subsequently, the gene functions and pathways which are significantly altered in HNSCC were identified using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Regulatory networks among DEGs and DEMs were then constructed, and transcription factors (TFs) potentially regulating the DEGs and DEMs were determined and a TF - miRNA - gene network was established. A total of 2,594 significant DEGs (1,087 upregulated and 1,507 downregulated), and 25 DEMs (8 upregulated and 17 downregulated) were identified in HNSCC compared with normal control samples. These DEGs were significantly enriched in GOs and KEGG pathways such as mitosis, cell cycle, Wnt, JAK/STAT and TLR signaling pathway. CPBP, NF-AT1 and miR-1 were situated in the central hub of the TF - miRNA - gene network, underlining their central roles in regulatory processes specific for HNSCC. The present study enhanced the current understanding of the molecular mechanisms underlying HNSCC and may offer novel strategies for its prevention, diagnosis and treatment.