Human topoisomerase II-alpha is highly expressed in sinonasal-inverted papilloma, but not in inflammatory polyp

Advances in recurrence and malignant transformation of sinonasal inverted papillomas

Sinonasal inverted papilloma (SIP) is a benign tumor of the nasal cavity and sinus. SIP is characterized by aggressive malignant transformation and a high rate of recurrence. Inadequate removal of the tumor during surgery is one of the most significant contributors to SIP recurrence. A growing body of evidence suggests that molecular alteration in SIP, including human papilloma virus infections, single nucleotide polymorphisms of key genes, deregulation of signaling pathways and immunological changes, may lead to SIP occurrence and malignant transformation. However, the extent to which these molecular mechanisms contribute to SIP pathology and transformation remains unclear due to limited research. Further studies are warranted to elucidate the primary dependent factors that contribute to SIP etiology. The present article reviewed risk factors of progression and recurrence of SIP, including outdoor and industrial occupational exposure, smoking, septal deviation, SIP location, recurrent cases, stage of SIP-associated squamous cell carcinoma and choice of surgical method.

TOP2Ahigh is the phenotype of recurrence and metastasis whereas TOP2Aneg cells represent cancer stem cells in prostate cancer

Recurrence and metastasis are the main causes of death for prostate cancer patients and cancer stem cells (CSCs) are proposed to play important roles in cancer recurrence and metastasis. It is generally thought that genes upregulated in recurrent/metastatic disease are likely biomarkers of CSCs. Hence we analyzed multiple microarray datasets on prostate tumor tissues to identify upregulated genes associated with cancer recurrence/metastasis, and tried to explore whether those genes were true biomarkers of prostate CSCs. Our results indicated that TOP2A was the most highly upregulated gene in recurrent/metastatic prostate cancer, and its high expression was positively correlated with poor prognosis in patients. Using a promoter reporter system, we unexpectedly discovered enrichment of CSCs in TOP2A^neg cells. Compared to TOP2A^high cells, TOP2A^neg cells formed spheres and tumors more efficiently, and became enriched in the presence of stresses. Analysis of cell divisions by time lapse imaging indicated that more slow-cycling cells were observed in TOP2A^neg cells while the proportion of abnormal divisions was higher in TOP2A^high cells. Our studies demonstrate that TOP2A^high is the phenotype of recurrence/metastasis but TOP2A^neg cells show slow cycling and have CSCs properties in prostate cancer, which has significant implications for prostate cancer therapy.

14-3-3 gene expression exerts isoform-dependent functions in sinonasal pathophysiology

The expression profiles of 14-3-3β and θ isoforms, known to exert both oncogenic and antiapoptotic effects, were assessed in different entities of nasal pathophysiology. Flow cytometry and immunohistochemistry were used on paraffin-embedded sections of 51 inverted papillomas (IP), 26 nasal polyps (NP), 9 polyps with IP (NPIP) and 10 specimens of normal epithelium (NE). 14-3-3β expression was significantly upregulated in IP as compared with both NP (p=0.015) and NE (p=0.002). 14-3-3β was also increased in NPIP as compared with NE (p=0.008). 14-3-3β cytoplasmic staining was more pronounced in basal cells of the respiratory epithelium although serous glands and the vascular system were often positive as well. High 14-3-3β immunopositivity in IP patients concurred with increased proliferative activity shown by PCNA immunostaining (p=0.04). Expression of 14-3-3θ was also found increased in IP and NPIP patients, compared to NP (p=0.005, p=0.002 respectively) and NE (p=0.004 and p=0.001 respectively). 14-3-3θ cytoplasmic immunopositivity was detected in columnar epithelium, particularly in basal and subluminal cells, whereas no immunoreactivity was observed in NP and NE. Our results demonstrate differential expression of 14-3-3β and θ isoforms in sinonasal pathophysiology, supporting their implication, respectively, in the proliferative and inflammatory process engaged in the formation of IP.

Skull base inverted papilloma: a comprehensive review

Skull base inverted papilloma (IP) is an unusual entity for many neurosurgeons. IP is renowned for its high rate of recurrence, its ability to cause local destruction, and its association with malignancy. This paper is a comprehensive review of the reports, studies, and reviews published in the current biomedical literature from 1947 to September 2010 and synthesize this information to focus on its potential invasion to the base of the skull and possible intradural extension. The objective is to familiarize the clinician with the different aspects of this unusual disease. The role of modern diagnostic tools in medical imaging in order to assess clearly the limits of the tumors and to enhance the efficiency and the safety in the choice of a surgical approach is pointed out. The treatment guidelines for IP have undergone a complex evolution that continues today. Radical excision of the tumour is technically difficult and often incomplete. Successful management of IP requires resection of the affected mucosa which could be achieved with open surgery, endoscopic, or combined approach. Radio and chemotherapy were used for certain indications. More optimally research would be a multicenter randomized trials with large size cohorts.

Apoptotic and proliferative status in HPV (+) and HPV (-) inverted papilloma patients. Correlation with local recurrence and clinicopathological variables

Inverted papilloma (IP) is a rare sinonasal benign lesion characterized by aggressive biological behavior. Our aim was to evaluate the expression of various proliferation and apoptotic markers and the presence of HPV genotypes in paraffin sections gathered from surgically treated IP patients. Immunohistochemistry for PCNA, bax, cytochrome c and caspase-8 and flow cytometry for the detection of apoptosis, necrosis and ki67 expression were performed. The identification of various HPV subtypes was achieved by nested PCR amplification. Nasal polyps (NP) and specimens from normal nasal epithelium (NE) were used as controls. PCNA was more frequently expressed in IP compared to NE (p=0.04) and caspase-8 and bax staining were less frequently observed in IP compared to NP (p=0.004 and p=0.01 respectively) and NE (p=0.003 and p=0.01, respectively). IP and NP presented significantly higher Ki67 flow cytometry values compared to NE (p<0.001 and p=0.02 respectively). Cytochrome c was more frequently expressed in IP specimens with more prominent inflammation (p=0.02). A low HPV DNA detection rate was observed. Neither HPV status nor any of the apoptotic or proliferative markers studied was associated with the patients' clinicopathological characteristics. Increased Ki67 appeared to correlate with disease recurrence (p=0.01). Increased PCNA and Ki67 and decreased bax and caspase-8 expression indicate that cell proliferation is increased while apoptosis is inhibited in IP, explaining its biological behavior.

Histopathological changes of the nasal mucosa induced by smoking

Changes in the histopathology of the respiratory epithelium in response to cigarette smoking have been studied in depth in the lungs, but data on the nasal lining are lacking. The aim of the present retrospective study was to investigate the histological changes that occur in the nasal mucosa of smokers compared with non-smokers. The study group included 47 patients who underwent partial resection of the inferior turbinates. Archival nasal tissue samples were collected and examined by light microscopy: the number of goblet cells was counted, and the degree of inflammation, congestion, and edema was graded as mild, moderate, or severe. Epithelial thickness was measured as well. Findings were compared between smokers (n = 21) and non-smokers (n = 26). On statistical analysis, significant differences were found between the smokers and non-smokers in mean number of goblet cells in the nasal epithelium, 43.43 +/- 16.80 vs. 16.23 +/- 5.65 respectively (p < 0.0001), mean edema grade, 2.43 +/- 0.75 vs. 1.12 +/- 0.33 respectively (p < 0.0001), and mean epithelial thickness, 111.9 +/- 25.8 microm vs. 60.4 +/- 18.4 microm respectively (p < 0.0001). The corresponding mean values of congestion were 2 +/- 0.71 and 1.27 +/- 0.67 (p < 0.001), and of inflammation, 1.81 +/- 0.60 and 1.81 +/- 0.85 (NS). In conclusion, the histopathological findings in the nasal mucosa of smokers resemble reported findings in the bronchial respiratory epithelium. The main differences from non-smokers are greater goblet cell hyperplasia and thicker epithelium.

Sinonasal inverted papilloma: narrative review

BACKGROUND

Sinonasal inverted papilloma is a benign condition with the potential for recurrence and malignant change. Over the past few decades, numerous studies and reviews have addressed different aspects of this condition.

OBJECTIVE

To amalgamate the current literature on inverted papilloma, in order to review the evidence and consider the gaps in current knowledge.

METHODS

Retrospective, narrative review.

RESULTS

The reported incidence of inverted papilloma varies between centres and is affected by selection bias. The exact aetiology of inverted papilloma is not fully understood. Currently, there is no reliable histological or biological marker to predict the probability of recurrence or malignant transformation. There is no universally accepted staging system available for sinonasal inverted papilloma. Complete surgical removal of the tumour is the mainstay of treatment, but the method of choice depends on the extent of the disease, the skill of the surgeon and the technology available.

CONCLUSION

In order to compare different studies and to enable meta-analysis of the literature, there should be a universally accepted staging and classification system for sinonasal inverted papilloma. Further research on the aetiology of sinonasal inverted papilloma, and on biological markers for its recurrence and malignant transformation, is required. To enable meaningful future research, we would encourage multicentre participation with a consensus on management.