Up-regulation of interleukin-17 expression by human papillomavirus type 16 E6 in nonsmall cell lung cancer

Narciclasine induces colon carcinoma cell apoptosis by inhibiting the IL-17A/Act1/TRAF6/NF-κB signaling pathway

IL-17 A is a promoter of colorectal cancer initiation and progression. Narciclasine is a polyhydroxy alkaloid compound isolated from Narcissus plants, which has potent anti-inflammatory and antitumor actions. The effects of narciclasine on colorectal tumors were evaluated, with a focus on IL-17 A. Narciclasine reduced the growth of HCT-116 and SW-480 colon cancer cells in vitro and in vivo in murine xenografts. The results of flow cytometry on JC-1 and Annexin V/PI revealed that narciclasine significantly reduced the mitochondrial membrane potential and induced apoptosis, findings confirmed by western blotting results of reduced Bcl-2 and enhanced Bax expression, as well as accumulation of cleaved Caspase-3, Caspase-8, Caspase-9, and cytoplasmic Cytochrome-c. After narciclasine incubation, IL-17 A, Act1, and TRAF6 were down-regulated, while p-P65 (Ser536) accumulated in the cytoplasm, a finding confirmed by laser scanning confocal microscopy. IL17A substitution could partly reverse these narciclasine effects while they were elevated by IL17A silencing. Moreover, IL-17 A, Act1, and TRAF6 were significantly expressed to greater extents in human colorectal cancer compared to normal adjacent tissue specimens and were closely linked with a poor prognosis. This study provided evidence that narciclasine may be a useful therapeutic drug for colorectal cancer treatment through its actions in down-regulating the L-17A/Act1/TRAF6/NF-κB anti-apoptotic signaling pathway.

The association between human papillomavirus and lung cancer: A Mendelian randomization study

BACKGROUND

To investigate the causal relationship between human papillomavirus (HPV) and lung cancer, we conducted a study using the two-sample Mendelian randomization (TSMR).

METHOD

Data from genome-wide association studies (GWAS) were analyzed with HPV E7 Type 16 and HPV E7 Type 18 as exposure factors. The outcome variables included lung cancer, small cell lung cancer, adenocarcinoma and squamous cell lung cancer. Causality was estimated using inverse variance weighted (IVW), MR-Egger and weighted median methods. Heterogeneity testing, sensitivity analysis, and multiple validity analysis were also performed..

RESULTS

The results showed that HPV E7 Type 16 infection was associated with a higher risk of squamous cell lung cancer (OR = 7.69; 95% CI:1.98-29.85; p = 0.0149). HPV E7 Type 18 infection significantly increased the risk of lung adenocarcinoma (OR = 0.71; 95% CI: 0.38-1.31; p = 0.0079) and lung cancer (OR = 7.69; 95% CI:1.98-29.85; p = 0.0292). No significant causal relationship was found between HPV E7 Type 16 and lung adenocarcinoma, lung cancer, or small cell lung carcinoma, and between HPV E7 Type 18 and squamous cell lung cancer or small cell lung carcinoma.

CONCLUSIONS

This study has revealed a causal relationship between HPV and lung cancers. Our findings provide valuable insights for further mechanistic and clinical studies on HPV-mediated cancer.

The emerging role of human papillomavirus in lung cancer

Lung cancer stands as one of the most lethal diseases and is the foremost cause of cancer-related mortalities worldwide. The pathophysiology of lung cancer is multifaceted, and it includes multiple cell signaling pathways and other complex factors such as oxidative stress and genetics. The association of HPV with lung carcinogenesis was first proposed in 1979, and since then, scientists worldwide have been putting forward several hypotheses to establish a relationship between this virus and lung cancer. Although studies have reported the presence of HPV in lung cancer, the exact mechanism of entry and the route of transmission have not been elucidated clearly till date. Numerous studies across the globe have detected differentially expressed HPV oncoproteins in lung cancer patients and found their association with the critical cell signaling pathways that leads to the development and progression of lung cancer. Many reports have also provided evidence stating the involvement of HPV in determining the survival status of lung cancer patients. The present review recapitulates the studies evincing the association of HPV and lung cancer, its route of transmission and mechanism of action; the detection of the virus and treatment opportunities for HPV-positive lung cancer; and the severity associated with this disease. Therefore, this will provide an explicit idea and would help to develop preventive measures and specific as well as effective treatment for HPV-associated lung carcinogenesis.

SQSTM1/p62 Knockout by Using the CRISPR/Cas9 System Inhibits Migration and Invasion of Hepatocellular Carcinoma

Migration and invasion play crucial roles in the progression of hepatocellular carcinoma (HCC), but the underlying mechanisms are not clear. Analysis of clinical samples indicates that SQSTM1/p62 is highly expressed in HCC and seriously affects the prognosis of patients. Subsequently, we showed that SQSTM1/p62 knockout using the CRISPR/Cas9 system led to impaired migration and invasion of HCC, upregulated Keap1, and promoted the inhibitory effect of Keap1 on Nrf2. Then, the inactivation of Nrf2 inhibited the expression of matrix metalloproteinases (MMPs), thus attenuating the migration and invasion of HCC. We also found that SQSTM1/p62 knockout significantly inhibited migration and invasion in a lung metastasis model of nude mice with HCC. Furthermore, we found that cisplatin not only significantly inhibited the expression of SQSTM1/p62 but also slowed down the migration and invasion of HCC, while the inflammatory microenvironment accelerated the migration and invasion of HCC. These results suggest for the first time that SQSTM1/p62 knockout inhibits the migration and invasion of HCC through the Keap1/Nrf2/MMP2 signaling pathway. SQSTM1/p62 may be developed into a key drug target to regulate the migration and invasion of HCC cells.

Resveratrol suppresses lung cancer by targeting cancer stem-like cells and regulating tumor microenvironment

Increasing evidence indicate that cancer stem cells (CSCs) are the key driver of tumor initiation and recurrence. The cellular and soluble components of the tumor microenvironment (TME) impact on cancer initiation and progression, such as cytokines and chemokines. Thus, targeting CSCs and TME is a novel anti-cancer approach. Resveratrol (RES), a bioactive phytochemical extracted from various plants, exhibits tumor-suppressing activities in lung cancer, yet the mechanism remains poorly understood. Our data showed that the expression level of IL-6 was positively correlated with the presence of lung cancer stem-like cells (LCSCs) in human lung cancer tissues. In vitro results showed that IL-6 was highly elevated in lung cancer sphere-forming cells and could enhance the stemness of LCSCs, including tumor sphere formation ability, the percentage of CD133 positive cells, and the expression of LCSC specific markers (CD133, ALDH1A1 and Nanog). Simultaneously, our results confirmed that RES effectively inhibited LCSC properties, downregulated Wnt/β-catenin signaling and reduced IL-6 level in vitro and in vivo. Furthermore, we found RES treatment attenuated the activation of Wnt/β-catenin signaling by LiCl (GSK3β agonist). IL-6-promoted LCSC properties and Wnt/β-catenin signaling was also reversed by RES. Taken together, these data illustrated that RES inhibited lung cancer by targeting LCSCs and IL-6 in TME. The novel findings from this study provided evidence that RES exhibited multi-target effects on suppression of lung cancer and could be a novel potent cancer-preventive compound.

Correlation of serum interleukin 17 and macrophage migration inhibitory factor levels with clinical response to intralesional Candida antigen and their potential use as predictors of clinical outcome in patients with multiple common warts

BACKGROUND

Candida antigen injection is one of the most widely used intralesional immunotherapy in the treatment of warts. It acts through the induction of systemic immune response. The pattern of cytokines production may play an integral role in its mechanism of action.

AIM

To investigate the possible relation between serum levels of IL17 and MIF, and the clinical response to intralesional Candida antigen in multiple common warts.

METHODS

A total of 90 patients with multiple common warts were divided into 2 groups. Sixty patients received intralesional Candida antigen injection into the largest wart, controlled against thirty patients who had intralesional saline, as placebo. The injection was done at a 2-week interval for 5 doses. Blood samples were obtained from both groups, and serum levels of IL17A and MIF were estimated at baseline and 2 weeks after the last session using ELISA kits.

RESULTS

Complete clearance of warts was statistically higher in the Candida antigen group (40% of the patients) compared to the saline group (p < 0.05). The serum levels of IL17 had significantly declined from baseline, while the level of MIF had risen after intralesional Candida antigen injection, but not in the saline group. At a cutoff level of 316 pg/ml, IL17 had a sensitivity of 83.3% to predict therapeutic response.

CONCLUSION

IL17A and MIF may have possible roles in the mechanism of action of Candida antigen in the treatment of common warts. At a certain level, serum IL17A may be a potential predictor of response to treatment.

Interleukin-17-A multifaceted cytokine in viral infections

Viral infections are a major threat to the human population due to the lack of selective therapeutic measures. The morbidity and mortality reported worldwide are very alarming against viral pathogens. The proinflammatory environment is required for viral inhibition by initiating the host immune response. The host immune response fights these pathogens by secreting different cytokines. Interleukin-17 (IL-17) a proinflammatory cytokine mainly produced by T helper type 17 cells, plays a vital role in the regulation of host immune response against various pathogens, including viruses. However, dysregulated production of IL-17 induces chronic inflammation, autoimmune disorders, and may lead to cancer. Recent studies suggest that IL-17 is not only involved in the antiviral immune response but also promotes virus-mediated illnesses. In this review, we discuss the protective and pathogenic role of IL-17 against various viral infections. A detailed understanding of IL-17 during viral infections could contribute to improve therapeutic measures and enable the development of an efficient and safe IL-17 based immunotherapy.

Role of interleukin-17 in human papillomavirus infection and associated malignancies

Human papillomavirus infection is among the leading viral infections in the world, causing severe mortality and morbidity. The virus mainly targets the female genital tract-cervix, vulva, anus but it is also reported to infect the lungs and oropharyngeal region of the body. The host immune response plays a vital role in the persistence of viral infection. Interleukin 17 (IL-17) is mainly secreted by Th17 cells and mediates the immune response that enhances the disease severity in HPV infection. IL-17 is reported to promote lesions and tumour progression by creating a hyperinflammatory condition leading to cancer. The current minireview summarizes the pathogenic role of IL-17 in HPV infection and HPV-induced malignancies. Further study on IL-17 associated pathology of HPV infection would be useful in developing therapeutic measures.

Possible Oncogenic Viruses Associated with Lung Cancer

Lung cancer is the most common cause of cancer death worldwide. Tobacco smoking is the most predominant etiology for lung cancer. However, only a small percentage of heavy smokers develop lung cancer, which suggests that other cofactors are required for lung carcinogenesis. Viruses have been central to modern cancer research and provide profound insights into cancer causes. Nevertheless, the role of virus in lung cancer is still unclear. In this article, we reviewed the possible oncogenic viruses associated with lung cancer.

Association of human papillomavirus infection and inflammation in cervical cancer

Human papillomavirus (HPV) associated cancers, and in particular cervical cancer, are considered to be directly stimulated by HPV oncogenes. Alternatively, these types of cancers could also be indirectly stimulated by HPV-induced chronic inflammations, which in turn are also caused by HPV oncogenes activity. Chronic inflammation is associated with repeated tissue injury and development of mutations in the vital tumor suppressor genes. Thus, it is important to understand that the persistent HPV infection and its associated chronic inflammation is responsible for the progression of HPV-induced cancers. HPV E5, E6 and E7 could upregulate the expression of cyclooxygenase (COX)-2 and prostaglandin (PG) E2 followed by the activation of the COX-PG pathway. This pathway is assumed to be the main cause of HPV-induced inflammation. Additionally, HPV oncogenes could have an impact on the upregulation of pro-inflammatory cytokines in HPV-positive patients. The upregulation of such cytokines accelerates the incidence of inflammation following HPV infection. Other factors such as microRNAs, which are involved in the inflammation pathways and aging, give rise to the increased level of pro-inflammatory cytokines and could also be responsible for the acceleration of HPV-induced inflammation and consequent cervical cancer. In this review, the exact roles of HPV oncogenes in the occurrence of inflammation in cervical tissue, and the effects of other factors in this event are evaluated.

Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Induces Interleukin-17 Production via Activation of the IRAK1-PI3K-p38MAPK-C/EBPβ/CREB Pathways

Porcine reproductive and respiratory syndrome virus (PRRSV) is widely prevalent in pigs, resulting in significant economic losses worldwide. A compelling impact of PRRSV infection is severe pneumonia. In the present study, we found that interleukin-17 (IL-17) was upregulated by PRRSV infection. Subsequently, we demonstrated that PI3K and p38MAPK signaling pathways were essential for PRRSV-induced IL-17 production as addition of phosphatidylinositol 3-kinase (PI3K) and p38MAPK inhibitors dramatically reduced IL-17 production. Furthermore, we show here that deleting the C/EBPβ and CREB binding motif in porcine IL-17 promoter abrogated its activation and that knockdown of C/EBPβ and CREB remarkably impaired PRRSV-induced IL-17 production, suggesting that IL-17 expression was dependent on C/EBPβ and CREB. More specifically, we demonstrate that PRRSV nonstructural protein 11 (nsp11) induced IL-17 production, which was also dependent on PI3K-p38MAPK-C/EBPβ/CREB pathways. We then show that Ser74 and Phe76 amino acids were essential for nsp11 to induce IL-17 production and viral rescue. In addition, IRAK1 was required for nsp11 to activate PI3K and enhance IL-17 expression by interacting with each other. Importantly, we demonstrate that PI3K inhibitor significantly suppressed IL-17 production and lung inflammation caused by HP-PRRSV in vivo, implicating that higher IL-17 level induced by HP-PRRSV might be associated with severe lung inflammation. These findings provide new insights onto the molecular mechanisms of the PRRSV-induced IL-17 production and help us further understand the pathogenesis of PRRSV infection.IMPORTANCE Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) associated with severe pneumonia has been one of the most important viral pathogens in pigs. IL-17 is a proinflammatory cytokine that might be associated with the strong inflammation caused by PRRSV. Therefore, we sought to determine whether PRRSV infection affects IL-17 expression, and if so, determine this might partially explain the underlying mechanisms for the strong inflammation in HP-PRRSV-infected pigs, especially in lungs. Here, we show that PRRSV significantly induced IL-17 expression, and we subsequently dissected the molecular mechanisms about how PRRSV regulated IL-17 production. Furthermore, we show that Ser74 and Phe76 in nsp11 were indispensable for IL-17 production and viral replication. Importantly, we demonstrated that PI3K inhibitor impaired IL-17 production and alleviated lung inflammation caused by HP-PRRSV infection. Our findings will help us for a better understanding of PRRSV pathogenesis.

PI3K/Akt/HIF-1α signaling pathway mediates HPV-16 oncoprotein-induced expression of EMT-related transcription factors in non-small cell lung cancer cells

Background: Our previous studies have demonstrated that human papillomaviruse (HPV)-16 oncoproteins promoted epithelial-mesenchymal transition (EMT), leading to non-small cell lung cancer (NSCLC) progression, but the underlying molecular mechanisms still remain unclear. PI3K/Akt/HIF-1α signaling pathway has been reported to mediate hypoxia-induced EMT. In this study, we further explored the role of PI3K/Akt/HIF-1α signaling pathway in HPV-16 oncoprotein-induced EMT in NSCLC cells.

Methods: A549 and NCI-H460 NSCLC cells were transiently transfected with pEGFP-HPV-16 E6 or E7 constructs. Western blotting and RT-qPCR were respectively performed to determine the protein and mRNA expression of EMT-related transcription factors. HPV-16 E6 or E7-transfected NSCLC cells were co-transfected with specific HIF-1α-siRNA or pretreated with different concentrations of LY294002, a specific PI3K inhibitor, followed by the analysis of expression of EMT-related transcription factors. The correlation between HIF-1α and EMT-related transcription factors in NSCLC tissues was analyzed by immunohistochemical staining and Spearman rank correlation coefficient.

Results: HPV-16 E6 and E7 oncoproteins upregulated the expression of Slug and Twist1, the EMT-related transcription factors, at both protein and mRNA levels in A549 and NCI-H460 cells. The co-transfection with specific HIF-1α-siRNA, but not the non-specific (NS)-siRNA, significantly abrogated HPV-16 oncoprotein-induced upregulation of ZEB1, Snail1, Slug, and Twist1 at both protein and mRNA levels. Additionally, pretreatment with LY294002 obviously blocked HPV-16 E6- and E7-induced Snail1, Slug, and Twist1 protein expression in A549 and NCI-H460 cells. Further analysis of clinical specimens showed that HIF-1α protein was strongly expressed in NSCLC tissues, which was positively correlated with ZEB1, Snail1, Slug, and Twist1 protein expression.

Conclusions: PI3K/Akt/HIF-1α may contribute to the progression of HPV-associated NSCLC via mediating the expression of EMT-related transcription factors in NSCLC cells.

Interleukin‑17A and heparanase promote angiogenesis and cell proliferation and invasion in cervical cancer

Interleukin‑17A (IL‑17A) is a CD4 T-cell-derived pro-inflammatory cytokine that is involved in human cervical tumorigenesis. Heparanase (HPSE) is an endo-glycosidase expressed in mammals, which has been confirmed to be associated with cervical cancer invasion. In the present study, it was hypothesized that IL‑17A and HPSE are key proteins promoting tumor angiogenesis and cell proliferation and invasion in cervical cancer. The expression of IL‑17A and HPSE in cervical cancer tissues was detected by immunohistochemical staining. In addition, the expression of IL‑17A and HPSE was down- and upregulated via RNAi and human recombinant proteins, and MTT and Transwell assays were performed to examine cervical cancer cell proliferation and invasion, respectively. Flow cytometry analysis was also performed to detect cell cycle distribution, and the levels of target mRNA and protein were evaluated by reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. IL‑17A and HPSE were highly expressed in cervical cancer tissues, and microvessel density was notably higher in the IL‑17A-positive group. IL‑17A and/or HPSE recombinant protein promoted the proliferation and invasion of cervical cancer cells, increased the proportion of cells in the G2/M phase, and enhanced the mRNA and protein expression of human papillomavirus E6, P53, vascular endothelial growth factor and CD31, whereas downregulation of IL‑17A and/or HPSE exerted the opposite effects. Furthermore, downregulation of IL‑17A and/or HPSE was found to inhibit the expression of nuclear factor (NF)-κB P65. In summary, IL‑17A and HPSE may promote tumor angiogenesis and cell proliferation and invasion in cervical cancer, possibly via the NF-κB signaling pathway. These findings may lead to the identification of new diagnostic markers and therapeutic targets.

Increased BATF expression is associated with the severity of liver damage in patients with chronic hepatitis B

T helper (Th) 17 cells have a critical role in the pathogenesis of chronic hepatitis B virus (HBV) infection, and basic leucine zipper transcription factor, ATF-like (BATF) is a newly identified transcriptional factor regulating the differentiation of Th17 cells. However, its precise role in patients with chronic hepatitis B remains unclear. Sixty chronic hepatitis B (CHB) patients, twenty-two acute-on-chronic hepatitis B liver failure (ACHBLF) patients and seventeen healthy controls were included in our study. Both peripheral and intrahepatic expressions of BATF were analyzed by flow cytometry, quantitative real-time polymerase chain reaction and immunohistochemical staining. Peripheral BATF mRNA and protein expression levels were higher in CHB patients than those in healthy controls. Particularly in ACHBLF patients, the BATF mRNA and protein levels were further increased over those in CHB patients. Intrahepatic BATF-positive infiltrating cells were enriched in portal area of CHB patients, and more positive cells were found in patients with higher inflammation grade. Peripheral BATF expression was positively correlated with serum parameters of liver injury and plasma HBV DNA load. Furthermore, a positive correlation was found between the frequency of BATF-positive CD3+ T cells and the increased Th17 response in chronic HBV-infected patients. BATF over-expression might augment Th17 cell response and relate to the disease progression of CHB.

The Role of Interleukin-17 in Lung Cancer

Tumour-associated inflammation is a hallmark of malignant carcinomas, and lung cancer is a typical inflammation-associated carcinoma. Interleukin-17 (IL-17) is an important inflammatory cytokine that plays an important role in chronic inflammatory and autoimmune diseases and in inflammation-associated tumours. Numerous studies have shown that IL-17 directly or indirectly promotes tumour angiogenesis and cell proliferation and that it inhibits apoptosis via the activation of inflammatory signalling pathways. Therefore, IL-17 contributes to the metastasis and progression of lung cancer. Research advances with respect to the role of IL-17 in lung cancer will be presented as a review in this paper.

Effect of human papillomavirus 16 oncoproteins on oncostatin M upregulation in oral squamous cell carcinoma

Human papillomavirus (HPV) infection modulates several host cytokines contributing to cancer development. Oncostatin M (OSM), an IL-6 family cytokine, acts to promote cell senescence and inhibit growth. Its dysregulation promotes cell survival, cell proliferation and metastasis in various malignancies. The effect of HPV on OSM dysregulation has not been investigated. To elucidate this, immunohistochemistry was used on formalin-fixed, paraffin-embedded oral squamous cell carcinoma (OSCC) tissues: HPV-positive (50) and HPV-negative (50) cases. Immortalized human cervical keratinocytes expressing HPV16E6 (HCK1T, Tet-On system) were used to demonstrate the role of HPV16E6 in OSM expression. In addition, a vector containing HPV16E6/E7 was transiently transfected into oral cancer cell lines. Cell viability, cell-cycle progression and cell migration were evaluated using flow cytometry and a wound healing assay, respectively. The results showed various intensities of OSM expression in OSCC. Interestingly, the median percentages of strongly stained cells were significantly higher in HPV-positive OSCCs than in HPV-negative OSCCs. To explore the role of HPV oncoproteins on OSM expression, the expression of HPV16E6 in the HCK1T Tet-On condition was induced by doxycycline and HPV16E6 was found to significantly upregulate levels of OSM mRNA and protein, with concomitant upregulation of c-Myc. In addition, the levels of OSM mRNA and protein in E6/E7 transiently transfected oral cancer cells also gradually increased in a time-dependent manner and these transfected cells showed greater viability and higher migration rates and cell-cycle progression than controls. This result demonstrates that HPV16 oncoproteins upregulate OSM and play an important role to promote OSCC development.

Candidate Soluble Immune Mediators in Young Women with High-Risk Human Papillomavirus Infection: High Expression of Chemokines Promoting Angiogenesis and Cell Proliferation

BACKGROUND

The causal interpretation of cervical immune response to Human Papillomavirus (HPV) infection is complex and poorly characterized mainly due to the delicate balance that exists between viral infection, increase of inflammatory cytokines and host risk factors. This study aims to explore the significance of cervical immune mediators associated to cell survival, angiogenesis and interaction with immune response, in predicting the risk to develop HPV-related intraepithelial lesions.

METHODS

A panel of 48 cytokines and growth factors were explored in a selected cohort of 168 immunocompetent women including 88 diagnosed with low (LSIL) or high (HSIL) squamous intraepithelial lesions of the cervix and 80 with normal cervical cytology (NIL). HPV genotyping was performed by Linear Array HPV test and the soluble concentration of 48 immune molecules was analyzed using the Bio-Plex platform.

RESULTS

The prevalence of single HR-HPV infection was 30% in NIL and 100% in LSIL and HSIL women. The expression of 13 cytokines, including interleukins IL-6, IL-3, IL-12p40, IL-12p70, IL-16, IL-18, LIF, of chemokines CCL7 (MCP-3), CXCL9 (MIG), CXCL12 (SDF-1α) and of the tropic factors VEGF, G-CSF, M-CSF were significantly associated with the presence of infection, with levels being higher in women with precancerous lesions compared to NIL HPV negative women. Only the growth factor GM-CSF was positively associated with the cytological abnormalities.

CONCLUSIONS

The ability of HR-HPV to escape from innate immune recognition and to orchestrate the production of specific inflammatory and growth factors, involved in early inflammatory response and in the cell-proliferating phase of intraepithelial damage, was documented in women before the development of cervical lesions.

Interleukin-17 acts as double-edged sword in anti-tumor immunity and tumorigenesis

Interleukin-17 (IL-17), a proinflammatory cytokine, mainly produced by Th17 cells, participates in both innate and adaptive immune responses and is involved in various diseases, including infectious diseases, autoimmune disorders and cancer. Emerging evidence indicates that IL-17 not only has an oncogenic role in tumorigenesis by regulating tumor angiogenesis and enhancing tumor immune evasion but also exerts anti-tumor functions by enhancing natural killer (NK) cells and cytotoxic T lymphocytes (CTLs) activation and through the recruitment of neutrophils, NK cells and CD4⁺ and CD8⁺ T cells to tumor tissue. In this review, we provide an overview on the basic biology of IL-17 and recent findings regarding its enigmatic double-edged features in tumorigenesis, with special attention to the roles of IL-17 produced by tumor cells interacting with other factors in the tumor microenvironment.

The role of the PI3K/Akt/mTOR signalling pathway in human cancers induced by infection with human papillomaviruses

Infection with Human papillomaviruses (HPVs) leads to the development of a wide-range of cancers, accounting for 5% of all human cancers. A prominent example is cervical cancer, one of the leading causes of cancer death in women worldwide. It has been well established that tumor development and progression induced by HPV infection is driven by the sustained expression of two oncogenes E6 and E7. The expression of E6 and E7 not only inhibits the tumor suppressors p53 and Rb, but also alters additional signalling pathways that may be equally important for transformation. Among these pathways, the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signalling cascade plays a very important role in HPV-induced carcinogenesis by acting through multiple cellular and molecular events. In this review, we summarize the frequent amplification of PI3K/Akt/mTOR signals in HPV-induced cancers and discuss how HPV oncogenes E6/E7/E5 activate the PI3K/Akt/mTOR signalling pathway to modulate tumor initiation and progression and affect patient outcome. Improvement of our understanding of the mechanism by which the PI3K/Akt/mTOR signalling pathway contributes to the immortalization and carcinogenesis of HPV-transduced cells will assist in devising novel strategies for preventing and treating HPV-induced cancers.

Human papillomavirus infection correlates with inflammatory Stat3 signaling activity and IL-17 level in patients with colorectal cancer

Background

Colorectal cancer (CRC) is a major burden of public health and healthcare worldwide. Microbiota has been suggested in promoting chronic inflammation in the intestine which, in turn, promotes tumor development. This study focuses on possible correlations of human papillomavirus (HPV) infection with proinflammatory Stat3 signaling activities and the resulting levels of its downstream proinflammatory cytokine IL-17 in CRC patients.

Methods

HPV was examined using HPV Genotyping Chip technology and constitutively active Stat3 (p-Stat3) and IL-17 levels were tested using immunohistochemistry (IHC) in paraffin-embedded cancerous and adjacent normal tissues (ANT) from a cohort of 95 CRC patients. Correlation analyses were performed between HPV infection and clinicopathological characteristics, Stat3 activities and IL-17 levels among these CRC patients.

Results

Three major findings were observed: (1) HPV infection existed in a high rate of CRC cases (48.4%, 46/95), of which 45 cases (45/46, 97.8%) were high-risk HPV16-positive and only one case was HPV53-positive. (2) HPV infection correlated with poorer clinical stages (III+IV) of CRC. (3) HPV infection strongly correlated with both constitutively higher Stat3 activities (P<0.01) and higher IL-17 levels (P<0.01) only in CRC tissues but not in ANT tissues.

Conclusions

HPV infection is common in CRC patients suggesting potentially preventive effectiveness of HPV vaccination among high-risk young individuals. We have for the first time revealed a tri-lateral relationship among HPV infection, constitutive Stat3 activity and IL-17 level, whose collaborative act may orchestrate a proinflammatory microenvironment in the colorectum that, in turn, may promote carcinogenesis and possibly facilitate progression of CRC.

Human papillomavirus and host genetic polymorphisms in carcinogenesis: a systematic review and meta-analysis

BACKGROUND

As the role of human papillomavirus (HPV) in carcinogenesis continues to rise, the role of genetic factors that modify this risk have become increasingly important. In this study, we reviewed the literature for associations between polymorphisms and HPV in carcinogenesis.

OBJECTIVE

To identify any associations of genetic polymorphisms with oncogenic HPV in carcinogenesis and to evaluate the methodology used.

STUDY DESIGN

Systematic literature review of HPV, genetic polymorphisms, and cancer risk. Odds ratios (OR), interaction terms, and p-values were tabulated. Meta-analyses and measures of heterogeneity were estimated using RevMan 5.1.

RESULTS

The cervix was the most frequently studied cancer site followed by the head and neck. Overall risk of cancer (cancer vs. control) was the most common comparison, whereas reports of initiation (pre-cancer vs. control) and progression (cancer vs. pre-cancer) were rare. Case-series and joint-effect of HPV and genotype on risk was evaluated frequently, but the independent effect of either risk factor alone was rarely provided. P53-Arg72Pro was the most commonly studied polymorphism studied. No consistent interaction was detected by meta-analysis in the HPV(+) [OR 0.98 (0.55-1.76)] or the HPV(-) [OR 1.10 (0.76-1.60)] subsets in head and neck cancer risk. Polymorphisms in genes known to encode proteins that physically interact with HPV were infrequently studied.

CONCLUSION

No consistent polymorphism-HPV interactions were observed. Study design, choice of candidate polymorphisms/genes, and a focus on overall risk rather than any specific portions of the carcinogenic pathway may have contributed to lack of significant findings.

Genetic dysregulation in recurrent respiratory papillomatosis

OBJECTIVES/HYPOTHESIS

Recurrent respiratory papillomatosis (RRP) is a devastating disease, caused by infection of the upper aerodigestive tract with human papillomavirus types 6 and 11. There is no cure for RRP, and surgical removal is the mainstay of treatment. The purpose of this project was to compare genes of cell cycle, apoptosis, and inflammatory cytokines in laryngeal papilloma versus normal tissue for a better understanding of the molecular mechanisms of the disease to discover novel therapies.

STUDY DESIGN

Basic science research study.

METHODS

Papilloma tissue was obtained from patients requiring surgical debridement. For comparison, normal mucosa was obtained from the excised uvula of patients undergoing uvulopalatopharyngoplasty. Total RNA was extracted from both groups and then probed using customized reverse transcriptase real time polymerase chain reaction gene arrays.

RESULTS

The custom arrays examine expression of 84 separate genes within the cell cycle, apoptosis, and inflammatory cytokine pathways. Our findings based on 11 papilloma samples run in comparison to normal mucosa shows that the MCL-1 gene of the apoptosis pathway is significantly downregulated. cytokine genes IL1-A, IL-8, IL-18, and IL-31 are also significantly dysregulated.

CONCLUSIONS

Genes of cell cycle and apoptosis are generally upregulated and downregulated, respectively, as expected in papilloma tissue, with MCL-1 achieving significance when compared to normal tissue. The finding of particular interest is that inflammatory cytokine genes were significantly downregulated, including IL1-A, IL-18, and IL-31. This finding may explain why patients infected with the virus are unable to mediate a T-cell immune clearance of their disease.

Role of innate immunity against human papillomavirus (HPV) infections and effect of adjuvants in promoting specific immune response

During the early stages of human papillomavirus (HPV) infections, the innate immune system creates a pro-inflammatory microenvironment by recruiting innate immune cells to eliminate the infected cells, initiating an effective acquired immune response. However, HPV exhibits a wide range of strategies for evading immune-surveillance, generating an anti-inflammatory microenvironment. The administration of new adjuvants, such as TLR (Toll-like receptors) agonists and alpha-galactosylceramide, has been demonstrated to reverse the anti-inflammatory microenvironment by down-regulating a number of adhesion molecules and chemo-attractants and activating keratinocytes, dendritic (DC), Langerhans (LC), natural killer (NK) or natural killer T (NKT) cells; thus, promoting a strong specific cytotoxic T cell response. Therefore, these adjuvants show promise for the treatment of HPV generated lesions and may be useful to elucidate the unknown roles of immune cells in the natural history of HPV infection. This review focuses on HPV immune evasion mechanisms and on the proposed response of the innate immune system, suggesting a role for the surrounding pro-inflammatory microenvironment and the NK and NKT cells in the clearance of HPV infections.

The ‘Trojan horse’ oncogenic strategy of HPVs in childhood

HPVs are considered to be the principal cause of cervical cancer worldwide. During the last decade, their possible oncogenic involvement has also been proposed in a substantial proportion of nongenital cancers, such as breast and lung cancer. The presence of high-risk HPVs in the neonatal oral mucosa supports the transmission of HPVs from the mother to her newborn. This review presents current evidence that supports the perinatal transmission of high-risk HPVs and suggests that this may be the initial step of the oncogenic strategy of high-risk HPVs in humans. The hypothesis that children are a unique reservoir of silent high-risk HPVs, analogously to the Trojan horse, should be investigated further.

Human papillomavirus up-regulates MMP-2 and MMP-9 expression and activity by inducing interleukin-8 in lung adenocarcinomas

Human papillomavirus (HPV) infection is associated with non-smoking female lung cancer. Our previous report demonstrated that HPV 16 promotes lung tumor cell progression by up-regulating interleukin-17 (IL-17). IL-17 and its downstream signaling mediator, interleukin-8 (IL-8), have been implicated to modulate a variety of pro-angiogenic factors and play important roles in tumor angiogenesis and metastasis. Accordingly, we hypothesized that HPV infection may potentiate tumorigenic and metastatic characteristics of the infected cells through IL-8. The goal of the present study was to determine whether HPV infection in lung adenocarcinoma cells can promote the expression of IL-8 and metalloproteinases (MMPs) to make the transformed cells equipped with angiogenic and metastatic characteristics. The expression of IL-8 and MMPs in HPV 16 E6-transfected H1299 cells was analyzed to examine the hypothesis. HPV 16 E6 up-regulates pro-angiogenic MMP-2 and MMP-9 through inducing IL-8 expression in lung cancer cells. The results indicate that, in addition to cell proliferation-related machinery, HPV infection promotes the expression and activities of angiogenic and metastatic molecules in lung adenocarcinoma cells. The cytokines induced by HPV infection may work together to confer the malignant and tumorigenic potentials on the infected cells by promoting machineries of growth, angiogenic and metastatic characteristics.

Anti-cancer versus cancer-promoting effects of the interleukin-17-producing T helper cells

Research on T helper 17 (Th17) cells with regard to immunoediting has revealed elusive results. Whereas enhanced Th17 response and related molecules such as interleukin (IL)-17, IL-21, IL-22, IL-23 and STAT3 accompanied tumor induction and progression, finding that tumor growth/stage was negatively correlated with increased infiltration of Th17 cells in the tumor mass has prompted elucidation of various antitumor mechanisms elicited by Th17 and their related molecules. The pro-tumor efficacy of Th17 response included promotion of neutrophilia and induction of angiogenic (e.g. VEGF, MMP2 and MMP9) and anti-apoptotic factors (e.g. Bcl-XL), as well as expansion and activation of myeloid-derived suppressor cells, which facilitate generation of tumor-specific regulatory T cells. Other tumor immunogenic settings revealed anti-tumor pathways including induction of cytotoxic activity, expression of MHC antigens, the ability Th17 cells to reside within the tumor, and to convert into IFN-γ producers. Notably, Th17 cell related molecules exert indirect pro- or anti-tumor effects via inducing viral persistence or mediating protective mechanisms against bacterial and viral infection. Herein, the recent literature revealing such immunoediting events mediated by Th17 cells and their associated molecules as delivered by various experimental regimens and observed in cancer patient are revised, with a focus on some proposed anti-cancer therapies.

Genetic variants of NOXA and MCL1 modify the risk of HPV16-associated squamous cell carcinoma of the head and neck

Abstracts

Increased frequency of circulating Th17 cells in acute-on-chronic hepatitis B liver failure

BACKGROUND

T helper (Th) 17 cells participate in the pathogenesis of liver diseases but their exact role in acute-on-chronic hepatitis B liver failure (ACHBLF) still remains obscure.

AIMS

This present study was aimed to characterize the circulating Th17 cells and to analyze their association with disease progression in ACHBLF.

METHODS

This retrospective study consisted of 40 ACHBLF patients, 40 chronic hepatitis B (CHB) patients and 20 healthy controls. The frequency of peripheral Th17 cells and IL-17 mRNA level in peripheral blood mononuclear cells (PBMCs) were estimated by flow cytometry and relative quantitative real-time polymerase chain reaction.

RESULTS

We found that the frequency of peripheral Th17 cells, as well as the level of IL-17 mRNA in PBMCs, was significantly increased in ACHBLF patients compared with CHB patients and healthy controls. In ACHBLF patients, the frequency of Th17 cells was positively correlated with serum total bilirubin (r = 0.392, P = 0.012) and model for end-stage liver disease scores (r = 0.383, P = 0.015), but negatively correlated with prothrombin activity (r = -0.317, P = 0.046). The same trend was observed as for relative expression of IL-17. Furthermore, the frequency of Th17 cells and IL-17 mRNA level were significantly elevated in non-survivors compared with survivors in ACHBLF patients.

CONCLUSIONS

These results suggested that Th17 cells as well as IL-17 might be related with disease severity and prognosis in ACHBLF patients.

Overexpression of human papillomavirus (HPV) type 16 oncoproteins promotes angiogenesis via enhancing HIF-1α and VEGF expression in non-small cell lung cancer cells

HPV-16 infection may play an important role in the development of non-small cell lung cancer (NSCLC) among never-smokers. Due to the critical role of angiogenesis in NSCLC development, we describe here the effect of HPV-16 oncoproteins on angiogenesis in NSCLC and the underlying mechanisms. We found that overexpression of HPV-16 E6 and E7 oncoproteins in NSCLC cells significantly promoted angiogenesis both in vitro and in vivo, and correspondingly, an enhanced expression of HIF-1α and VEGF, important pro-angiogenic factors in tumor angiogenesis. Meanwhile, overexpression of HPV-16 oncoproteins also led to HIF-1α-dependent increases in the secretion of several other pro-angiogenic factors, including IL-8. Our findings suggest that HPV-16 oncoproteins contribute to the development of NSCLC possibly by promoting HIF-1α/VEGF-mediated tumor angiogenesis.