Survivin expression in juvenile-onset recurrent respiratory papillomatosis

Expanded Basal Compartment and Disrupted Barrier in Vocal Fold Epithelium Infected with Mouse Papillomavirus MmuPV1

Laryngeal infection with low-risk human papillomaviruses can cause recurrent respiratory papillomatosis (RRP), a disease with severe effects on vocal fold epithelium resulting in impaired voice function and communication. RRP research has been stymied by limited preclinical models. We recently reported a murine model of laryngeal MmuPV1 infection and disease in immunodeficient mice. In the current study, we compare quantitative and qualitative measures of epithelial proliferation, apoptosis, differentiation, and barrier between mice with MmuPV1-induced disease of the larynx and surrounding tissues and equal numbers of uninfected controls. Findings supported our hypothesis that laryngeal MmuPV1 infection recapitulates many features of RRP. Like RRP, MmuPV1 increased proliferation in infected vocal fold epithelium, expanded the basal compartment of cells, decreased differentiated cells, and altered cell–cell junctions and basement membrane. Effects of MmuPV1 on apoptosis were equivocal, as with RRP. Barrier markers resembled human neoplastic disease in severe MmuPV1-induced disease. We conclude that MmuPV1 infection of the mouse larynx provides a useful, if imperfect, preclinical model for RRP that will facilitate further study and treatment development for this intractable and devastating disease.

OGFOD1 negatively regulated by miR-1224-5p promotes proliferation in human papillomavirus-infected laryngeal papillomas

Laryngeal papillomas (LP) is a difficult disease to manage due to its frequent recurrence, airway compromise, and risk of cancer. Recently, growing evidence indicates the aberrant expression of OGFPD1, a stress granule protein, links closely to the development of tumorigenesis; however, little is known about its role in LP progression. Here, we investigated the tumor promoting action of OGFOD1 in LP. The transcriptional and translational levels of OGFOD1 were significantly up-regulated in LP tissues and cells. Moreover, OGFOD1 promoted viability and proliferation, and inhibited LP cells apoptosis. We further revealed that OGFOD1 was directly targeted by miR-1224-5p, which was significantly down-regulated in LP. Overexpression of the miR-1224-5p suppressed OGFOD1-induced cell proliferation and viability, and promoted apoptosis of LP. In accordance, knockdown of miR-1224-5p inversed the inhibitory effects. In confederation of the central involvement of OGFOD1 in LP progression, targeting the miR-1224-5p/OGFOD1 pathway might provide a novel strategy for LP treatment.

Reduction of p38 mitogen-activated protein kinase and cyclooxygenase-2 signaling by isoflurane inhibits proliferation and apoptosis evasion in human papillomavirus-infected laryngeal papillomas

Human laryngeal papilloma (LP) is a human papillomavirus-induced hyperplastic tumor of the respiratory tract, which is characterized by rapid growth and apoptosis resistance. Isoflurane (ISO) inhibits proliferation and elicits apoptosis in cancer cells. The results of the present study found that the mRNA and protein levels of cyclooxygenase-2 (COX2) were higher in LP tissues than in normal laryngeal samples, and prostaglandin E₂ (PGE₂) production was increased in LP cells, as determined by quantitative polymerase chain reaction, western blot and radioimmunoassay analyses. Notably, the increase in COX2 and PGE₂ levels was significantly abrogated in the ISO-treated LP cells. The inhibitory effects of ISO on COX2 expression and activity depended on the inactivation of p38 mitogen-activated protein kinase (MAPK) in LP cells. By inhibiting the COX2 activity of LP cells, ISO treatment markedly suppressed cell viability and proliferation, as determined using Cell Counting Kit-8, flow cytometry and 5-ethynyl-20-deoxyuridine incorporation assays. Furthermore, ISO treatment promoted cell apoptosis, as demonstrated by flow cytometry, nucleosomal fragmentation and caspase-3 activity assays. Collectively, the present results suggest that COX2 is critical in the progression of LP, and ISO is a potential agent for LP therapy by impeding p38 MAPK/COX2 signaling.

Recurrent respiratory papillomatosis: a complex defect in immune responsiveness to human papillomavirus-6 and -11

Recurrent respiratory papillomatosis (RRP) is a rare disease of the larynx caused by infection with human papillomaviruses (HPV) -6 or -11, associated with significant morbidity and on occasion mortality. Here we summarize our current understanding of the permissive adaptive and innate responses made by patients with RRP that support chronic HPV infection and prevent immune clearance of these viruses. Furthermore, we provide new evidence of T(H)2-like polarization in papillomas and blood of patients with RRP, restricted CD4 and CD8 Vbeta repertoires, the effect of HPV-11 early protein E6 on T-cell alloreactivity, enriched Langerhans cell presence in papillomas, and evidence that natural killer cells are dysfunctional in RRP. We review the immunogenetic mechanisms that regulate the dysfunctional responses made by patients with RRP in response to HPV infection of the upper airway. In addition, we are identifying T-cell epitopes on HPV-11 early proteins, in the context of human leukocyte antigen (HLA) class II alleles enriched in RRP that should help generate a therapeutic vaccine. Taken together, RRP is a complex, multigene disease manifesting as a tissue and HPV-specific, immune deficiency that prevents effective clearance and/or control of HPV-6 and -11 infection.

ProEx C Stain Analysis in Recurrent Respiratory Papillomatosis

Objectives:

We evaluated the presence and pattern of ProEx C stain, a marker for the proliferative capacity of cells, in laryngeal tissues, including benign, malignant, and recurrent respiratory papilloma (RRP) specimens, and compared it to hematoxylin and eosin staining for the presence of dysplasia.

Methods:

We performed a retrospective study with chart review.

Results:

A total of 26 specimens (9 benign, 7 malignant, 10 RRP) representing 21 patients were stained. ProEx C stained positive in the nuclei of laryngeal tissue, consistent with its localization in cervical cytology specimens. Seven of 9 benign and 7 of 10 RRP specimens stained positive. The benign specimens were mostly polyps. The malignant specimens were either well or moderately differentiated squamous cell carcinoma, and they stained strongly and diffusely. In benign and RRP specimens, the basal layer typically stained positive. Other areas of epithelium stained weakly in benign specimens and variably in RRP specimens. Current analysis of hematoxylin and eosin—stained RRP specimens revealed that 30% of specimens had at least moderate dysplasia and 80% exhibited viral changes (koilocytosis).

Conclusions:

ProEx C is a clean and reliable stain in laryngeal tissue, and stains positive in RRP. This study could not definitively correlate positive ProEx C staining in areas of greater dysplasia, although a trend was observed. Further studies are necessary to determine whether ProEx C can be used in triage of cases of clinically aggressive RRP for closer follow-up or frequent operative intervention.

Immune dysregulation and tumor-associated gene changes in recurrent respiratory papillomatosis: a paired microarray analysis

Recurrent respiratory papillomas (RRP) are benign airway tumors, caused primarily by human papillomaviruses (HPV) types 6 and 11. The disease is characterized by multiple recurrences after surgical removal, with limited effective therapy. To identify novel targets for future therapy, we established transcriptional profiles for actively growing papillomas compared with autologous, clinically normal, laryngeal epithelia (adjacent tissue). Total ribonucleic acid (RNA) from 12 papillomas and 12 adjacent tissues were analyzed by microarray, and the matched sets of tissues compared by paired t test, to identify differentially expressed genes in papilloma tissues while minimizing variations intrinsic to individual patients. Quantitative polymerase chain reaction (PCR) was used to confirm the relative expression levels for a subset of genes. Within the 109 differentially expressed transcripts whose expression varied at least three-fold were two large groups of genes with related functions. The first group consisted of 18 genes related to host defense, including both innate and adaptive immunity. The second group contained 37 genes that likely contribute to growth of papillomas as benign tumors, since the altered pattern of expression also had been reported previously in many cancers. Our results support our previous studies that document a systemic T(H)2-like adaptive immune response in RRP, and suggest that there is a role for altered innate immunity in RRP as well. We propose that HPV 6 and 11 infection establishes a tumorigenic microenvironment characterized by alteration of both innate inflammatory signals and adaptive immune responses that prevent effective T(H)1-like response, in conjunction with altered expression of numerous genes that regulate cellular growth and differentiation.

Cidofovir modulated gene expression in recurrent respiratory papillomatosis

OBJECTIVE

Recurrent respiratory papillomatosis (RRP) is a benign aerodigestive tract neoplasm. Cidofovir, an antiviral drug, has demonstrated efficacy in slowing and/or reducing RRP recurrence. This investigation examined the differential gene expression of RPP before and after cidofovir use in vivo.

METHODS

Papillomas were harvested from two patients pre- and post-cidofovir treatment. RNA was extracted from the tissues and separate Serial Analysis of Gene Expression (SAGE) libraries created. Overall gene expression as well as relative gene expression in the four libraries was compared.

RESULTS

Over 19,000 tags were found in each of the libraries, with over 6000 unique transcripts identified in the pre-treatment and over 6000 identified in the post-cidofovir libraries of both patient 1 and 2. Following cidofovir treatment, the greatest up-regulation was in gene families associated with cell proliferation, metabolism, transport and response to biotic stimuli. Post-treatment up-regulation was seen in numerous specific genes, such as Interferon Regulatory Factor 7 (P=0.000014), which has been associated with virus-host interactions, passive viral induction of host immune response, and response to DNA damage stimulus. Down-regulation was demonstrated in gene families associated with transcription, regulation of nucleic acid metabolism, and signal transduction.

DISCUSSION

Creation of RRP SAGE libraries demonstrates a broad list of genes expressed in RRP, as well as significant differences in gene expression after exposure to cidofovir, potentially allowing for a more thorough understanding of important genetic pathways in RRP treatment. In addition, over 1400 unique transcripts were identified, which will facilitate new gene discovery in RRP research.

Detection of human papillomavirus and relevant tumor suppressors and oncoproteins in laryngeal tumors

PURPOSE

The mechanism of larynx oncogenesis is complex and controlled by various factors, most of them involved in cell proliferation and apoptosis. In this study, we evaluated the levels of two suppressor proteins (pRb and p53) and two oncogenic proteins (c-Myc and Bcl-2), as well as the apoptotic levels and the presence of human papillomavirus (HPV) in both tumor types.

EXPERIMENTAL DESIGN

Low- or high-risk HPV viral DNA was determined by PCR and in situ PCR; the level of cellular proteins was examined by immunohistochemistry; the presence of apoptotic cells was evaluated by in situ cell death detection.

RESULTS

Most laryngeal papillomatosis samples contained low-risk HPV determined by both techniques. However, 25% of laryngeal carcinoma samples were positive for HPV employing PCR or in situ PCR. In papillomatosis, pRb and p53 levels were higher than in normal larynxes, whereas laryngeal cancer presented the lowest levels. c-Myc oncogene expression was very low in normal and cancer tissues but highly increased in papillomatosis. Bcl-2 expression was low and showed no significant difference between laryngeal papillomatosis and normal larynxes. By contrast, Bcl-2 was clearly up-regulated in cancer. Normal larynx samples and those from laryngeal papillomatosis exhibited similar relatively high numbers of apoptotic cells, whereas in malignant tumors, these cells were scarce.

CONCLUSION

Our results suggest that HPV is an important risk factor in papillomatosis and in some malignant larynx tumors with a strong participation of cellular genes, specifically involved in proliferation and apoptosis. In benign papillomatosis lesions but not in larynx cancer, high p53 activity might preserve the apoptosis process. In larynx cancer, low p53 levels and high bcl-2 expression may be playing an important role to block apoptosis.

Up-regulation of Rac1 by epidermal growth factor mediates COX-2 expression in recurrent respiratory papillomas

Recurrent respiratory papillomas are epithelial tumors of the airway caused by human papillomaviruses. We previously reported that the epidermal growth factor receptor (EGFR) is overexpressed in papilloma cells, that cyclooxygenase-2 (COX-2) is induced, and that COX-2 expression in primary papilloma cells requires activation of the EGFR but not Erk. Rac1, a member of the Rho family of GTPases, is a key signaling element that is known to control multiple pathways downstream of the EGFR. Here we report that Rac1 is overexpressed in papilloma cells compared with normal laryngeal epithelial cells and that the increased levels of Rac1 are mediated by EGFR activation. Transfecting cells with Rac1-specific siRNA suppressed COX-2 expression. Surprisingly, Rac1 mediated phosphorylation of p38 mitogen-activated kinase in papilloma cells but not normal cells, and inhibition of p38 with the specific inhibitor SB202190 suppressed COX-2 expression in papilloma cells but had no effect on low-level COX-2 expression in normal cells. Thus, the signaling cascades that regulate COX-2 expression are different in HPV-infected papilloma cells, with a significant contribution by the EGFR-- Rac1-->p38 pathway.

Juvenile recurrent respiratory papillomatosis: still a mystery disease with difficult management

Juvenile recurrent respiratory papillomatosis (RRP) is the most common benign neoplastic disease of the larynx in children and adolescents and has a significant impact on patients and the health care system with a cost ranging from $60,000 to $470,000 per patient. The aim of this paper is to review the current literature on RRP and summarize the recent advances. RRP is caused by human papillomavirus (HPV; mainly by types 6 and 11). Patients suffer from wart-like growths in the aerodigestive tract. The course of the disease is unpredictable. Although spontaneous remission is possible, pulmonary spread and malignant transformation have been reported. Surgical excision, including new methods like the microdebrider, aims to secure an adequate airway and improve and maintain an acceptable voice. Repeated recurrences are common and thus overenthusiastic attempts to eradicate the disease may cause serious complications. When papillomas recur, old and new adjuvant methods may be tried. In addition, recent advances in immune system research may allow us to improve our treatment modalities and prevention strategies. A new vaccine is under trial to prevent HPV infection in women; the strongest risk factor for juvenile RRP is a maternal history of genital warts (transmitted from mother to child during delivery). Better understanding of the etiology of the disease and the knowledge of all available therapies is crucial for the best management of the affected patients.

Up-regulation of Rac1 by epidermal growth factor mediates COX-2 expression in recurrent respiratory papillomas

Recurrent respiratory papillomas are epithelial tumors of the airway caused by human papillomaviruses. We previously reported that the epidermal growth factor receptor (EGFR) is overexpressed in papilloma cells, that cyclooxygenase-2 (COX-2) is induced, and that COX-2 expression in primary papilloma cells requires activation of the EGFR but not Erk. Rac1, a member of the Rho family of GTPases, is a key signaling element that is known to control multiple pathways downstream of the EGFR. Here we report that Rac1 is overexpressed in papilloma cells compared with normal laryngeal epithelial cells and that the increased levels of Rac1 are mediated by EGFR activation. Transfecting cells with Rac1-specific siRNA suppressed COX-2 expression. Surprisingly, Rac1 mediated phosphorylation of p38 mitogen-activated kinase in papilloma cells but not normal cells, and inhibition of p38 with the specific inhibitor SB202190 suppressed COX-2 expression in papilloma cells but had no effect on low-level COX-2 expression in normal cells. Thus, the signaling cascades that regulate COX-2 expression are different in HPV-infected papilloma cells, with a significant contribution by the EGFR-- Rac1-->p38 pathway.

Epidermal growth factor-induced cyclooxygenase-2 expression is mediated through phosphatidylinositol-3 kinase, not mitogen-activated protein/extracellular signal-regulated kinase kinase, in recurrent respiratory papillomas

PURPOSE

Recurrent respiratory papillomas, caused by human papillomaviruses, are premalignant tumors that overexpress the epidermal growth factor receptor (EGFR). The goals of this study were as follows: (a) to evaluate the expression of cyclooxygenase-2 (COX-2) in papillomas, (b) to investigate the role of EGFR signaling in COX-2 expression, and (c) to determine whether COX-2 activity is important for the growth of papilloma cells.

EXPERIMENTAL DESIGN

Immunohistochemistry, Western blotting, and real-time PCR were used to determine levels of COX-2 in papilloma and normal laryngeal tissue. Explant cultures of both normal laryngeal and papilloma cells were used to define the signaling pathways that regulate COX-2 expression and investigate the potential of targeting COX-2 as a strategy to suppress papilloma growth.

RESULTS

COX-2 levels were markedly increased in papillomas. In vitro studies suggested that overexpression in papillomas reflected activation of EGFR-->phosphatidylinositol 3-kinase signaling. Treatment with prostaglandin E2 (PGE2) induced COX-2, whereas celecoxib, a selective COX-2 inhibitor, suppressed levels of COX-2, suggesting a positive feedback loop. Moreover, treatment with PGE2 stimulated papilloma cell growth, whereas celecoxib suppressed proliferation and induced apoptosis.

CONCLUSIONS

Overexpression of COX-2 in papillomas seems to be a consequence of enhanced EGFR-->phosphatidylinositol 3-kinase signaling. We propose a positive feedback loop for COX-2 expression, with induction of COX-2 resulting in enhanced PGE2 synthesis and further expression of COX-2 that contributes to the growth of papillomas in vivo. These data strengthen the rationale for evaluating whether nonsteroidal anti-inflammatory drugs, prototypic COX inhibitors, will be useful in the management of respiratory papillomas.

Survivin: a bifunctional inhibitor of apoptosis protein

Survivin is a recently discovered protein belonging to the inhibitor of apoptosis (IAP) gene family. IAP molecules are characterized by both the presence of a zinc-binding fold termed the baculoviral IAP repeat and the ability to suppress apoptosis. In addition to inhibiting apoptosis, survivin is essential for proper cell division. Survivin is expressed during embryonal development but is absent in most normal, terminally differentiated tissues. Survivin is also upregulated in a variety of human cancers, and its expression in tumors is associated with a more aggressive phenotype, shorter survival times, and a decreased response to chemotherapy. The exact mechanism behind the ability of survivin to inhibit apoptosis is still unclear. Furthermore, it is not known why this protein is upregulated in cancer. The purpose of this article is to provide an overview of the current knowledge of survivin, including its role in cell division and its expression in normal and neoplastic tissues. Although much of the current research in this field is focused on human medicine, this area also has potential significance for veterinary species.

Overview of recurrent respiratory papillomatosis

PURPOSE OF REVIEW

The purpose of this article is to review recent literature regarding pediatric recurrent respiratory papillomatosis (RRP) published within the last year. By reviewing and assessing these articles, a more clear understanding regarding the etiology and management of pediatric RRP can be obtained, allowing physicians to better care for their pediatric RRP patients.

RECENT FINDINGS

Pediatric RRP continues to be an extremely difficult management problem for otolaryngologists. This disease process continues to be a significant burden on the health care system and is a significant cause of morbidity in affected patients and their families. The incidence of RRP continues to be approximately 3.96 per 100,000 in the pediatric population. It has been noted recently that approximately 7 of every 1000 children born to mothers with vaginal condyloma develop pediatric RRP. Although the mainstay of surgical management has traditionally been the CO2 laser, newer surgical techniques have demonstrated efficacy in the management of pediatric RRP patients, including powered instrumentation and the pulse-dye laser. The traditional adjuvant medical therapies used for pediatric RRP continue to be commonly used, including interferon-alpha2a, retinoic acid, and indol-3-carbinol/diindolylmethane (I3C/DIM). Recently cidofovir has demonstrated efficacy in selected patients. In addition, current research regarding vaccine therapy for pediatric RRP has shown promise. Basic science research in the field of immunology has demonstrated multiple defects in cell-mediated immunity, which has shed further light on the etiology of pediatric RRP.

SUMMARY

Pediatric RRP continues to be a highly morbid disease process. New surgical and medical therapies offer hope for better control of this disease in affected patients. Recent advances in immunologic research offer the hope of immune system modulation and augmentation as potential future treatment modalities to better control this disease process.

Survivin study: what is the next wave?

Survivin, a novel member of inhibitor of apoptosis (IAP) protein family, is aberrantly expressed in cancer but undetectable in normal, differentiated adult tissues. Current studies suggest that survivin is implicated in both control of apoptosis and regulation of cell division. However, due to some inconsistent observations on survivin subcellular localization, there is debate about survivin's function in regulating apoptosis, cell division, or both. This review will discuss concepts, experimental methods, and interesting results that unify the different notions about survivin localization and function or point out gaps of knowledge about controversial issues. The author also intends to review various aspects of survivin studies, which were not emphasized or sufficiently discussed in previous reviews on survivin, and update recent developments that may reveal new applications of disease-oriented therapeutics in the coming years.