Joachim Woenckhaus

Genomic gain of PIK3CA and increased expression of p110alpha are associated with progression of dysplasia into invasive squamous cell carcinoma.

PIK3CA, encoding the catalytic subunit p110α of phosphatidylinositol 3‐kinase (PI3K), is activated in malignant diseases. However, the role of the PIK3CA gene aberrations for tumourigenesis of head and neck squamous cell carcinoma (HNSCC) is to date unclear. The present study was designed to determine the genomic aberration of PIK3CA in invasive HNSCC and dysplastic precursor lesions by fluorescence in situ hybridization (FISH) with a YAC probe, containing the PIK3CA gene, on isolated interphase nuclei from histomorphologically well‐defined regions of formalin‐fixed tissue sections and to compare these data with protein and mRNA expression of p110α. The mRNA and protein levels of p110α were assessed, respectively, by in situ hybridization and immunohistochemistry on consecutive tissue sections. Copy number gains at 3q26 were observed in one of six low‐to‐moderate dysplasias (17%) and in seven of nine high‐grade dysplasias (78%), as well as in 11 carcinomas (100%). In addition, one of seven high‐grade dysplasias (14%) and 6 of 11 carcinomas (55%) had amplifications of 3q26. The majority of cases with copy number gain in more than 50% of the cells and/or amplification in more than 10% of cells showed increased p110α mRNA and protein expression, whereas only two cases (18%) (one high‐grade dysplasia and one carcinoma) with no gain or low‐level gain displayed increased p110α protein expression. These data suggest that 3q26 copy number gain and amplification represent early genomic aberrations in HNSCC carcinogenesis. In addition, p110α mRNA and protein expression in HNSCC may be regulated by these genomic aberrations as well as by epigenetic events. Copyright

Prognostic value of PIK3CA and phosphorylated AKT expression in ovarian cancer

Disrupted phosphatidylinositol 3-kinase (PI3K) activity and its effect on the downstream target AKT plays an important role in malignant diseases. Gain and/or amplification of PIK3CA gene, encoding the catalytic subunit of phosphatidylinositol 3-kinase (p110α) and its increased expression are associated with enhanced PI3K activity in ovarian cancer cell lines. In this study, ovarian carcinomas with documented clinical outcome were assessed for genetic aberrations at the 3q26.3 locus, including PIK3CA, by fluorescence in situ hybridization. PIK3CA amplification was evaluated by quantitative real-time PCR with respect to a control gene situated at 3q13. The expression of p110α, phosphorylated AKT (pAKT) and the proliferation marker Ki-67 were immunohistochemically investigated. PIK3CA amplification and Ki-67 index were strong predictors for an early tumour-associated death. p110α expression correlated with 3q26.3 gain and Ki-67 index but not with the patient outcome. No relationship could be observed between p110α and pAKT or between pAKT and disease outcome. It is interesting to note that cases with a nuclear pAKT immunoreactivity showed a trend of improved overall survival. Our results underline the prognostic significance of PIK3CA in ovarian carcinoma and argue against a simple linear model of PIK3CA gain/amplification followed by PI3K activation and consecutive AKT phosphorylation in ovarian carcinoma.

Expression of PTEN in malignant and non-malignant human prostate tissues: comparison with p27 protein expression

The role of the putative tumour suppressor PTEN in prostate carcinogenesis is controversial. There are conflicting data regarding the rate of its gene inactivation, the role of transcriptional and post‐transcriptional factors, as well as its relationship to tumour progression and to the potential downstream regulator, the cell‐cycle inhibitor p27. The present study has assessed the in situ expression of PTEN mRNA and protein in 26 prostate intraepithelial neoplasias (PINs), 58 primary prostate carcinomas, and 15 metastases. Although there was a correlation between PTEN mRNA and protein expression, mRNA detection exceeded detection of protein in 19% of PINs and 30% of all invasive tumours. Using RT‐PCR and western blotting on microdissected tissue, this discrepancy was attributed, at least in part, to transcription of the PTEN pseudo‐gene, which lacks introns. Total or partial loss of PTEN protein occurred with tumour progression but this association was not statistically significant. Analysing the relationship between PTEN and p27 protein expression on consecutive sections by immunohistochemistry, the results do not support a direct link between the two oncosuppressors, other than an associated loss of expression in advanced tumour stages. However, in the basal cells of prostate glands and in most PINs, an inverse relationship was observed between PTEN and p27. This may reflect the existence of a functional balance that controls the cell cycle in prostatic epithelium and that is probably disturbed in invasive tumour cells. Copyright

Schleimhautveränderungen im Kehlkopf

ZusammenfassungHintergrundOptische Kohärenztomographie (OCT) und Hochfrequenzultraschall sind vielversprechende Methoden in der Frühdiagnostik von Kehlkopftumoren. In der Literatur fehlen jedoch verlässliche Angaben zur Epitheldicke von präkanzerösen und kanzerösen Läsionen der Stimmlippen.Patienten und MethodenIn der vorliegenden Studie wurde die Epithelbreite bei verschiedenen gut- und bösartigen Stimmlippenveränderungen lichtmikroskopisch bestimmt.ErgebnisseDie morphometrische Epithelvermessung ergab eine zunehmende Verdickung des Epithels über die verschiedenen Schweregrade der Dysplasie bis zum mikroinvasiven Karzinom, wobei eine zusätzlich vorliegende Entzündung keinen wesentlichen Einfluss auf die Gesamtepitheldicke hatte. Bei der mittelgradigen Dysplasie wurde eine doppelte, bei der schweren Dysplasie und dem Carcinoma in situ eine dreifache und beim mikroinvasiven Karzinom sogar eine sechsfache Zunahme der mittleren Epitheldicke gegenüber der normalen Schleimhaut gemessen. Gutartige Läsionen wie Reinke-Ödeme, Polypen, chronische Laryngitis und Papillome hingegen wiesen lediglich eine leichte Epithelverdickung auf.SchlussfolgerungenDurch Bestimmung der Epitheldicke in vivo mittels OCT oder Hochfrequenzultraschall lassen sich möglicherweise Rückschlüsse auf die Dignität einer laryngealen Läsion ziehen.AbstractBackgroundOptical coherence tomography (OCT) and high-frequency ultrasound are promising new methods in the early diagnosis of laryngeal cancer. However, no reliable values are given in the literature for epithelial thickness in early laryngeal cancer and its precursor lesions of the vocal folds.Patients and methodsIn the present study, epithelial thickness in different benign and malignant lesions of the vocal folds was determined histologically using a normal white light microscope.ResultsThe vocal fold mucosa showed progressive thickening over the different grades of dysplasia up to microinvasive carcinoma, while additional inflammation did not have any significant influence on the total epithelial thickness. In moderate dysplasia, however, the mean thickness of the epithelium was found to be double that of normal mucosa, and in severe dysplasia and carcinoma in situ, as much as three times that of normal mucosa. In the presence of microinvasive carcinoma, the average thickness of the epithelium was found to be as much as six times that in healthy mucosa. On the other hand, in case of benign lesions such as Reinke’s edema, polyps, chronic laryngitis, and papillomas there was only slight epithelial thickening.ConclusionsDetermination of epithelial thickness by OCT or high-frequency ultrasound may allow conclusions on whether or not a laryngeal lesion is malignant.

Loss of heterozygosity at 12p13 and loss of p27KIP1 protein expression contribute to melanoma progression.

Little is known about the mechanisms causing p27KIP1 decrease in melanomas. Therefore, we performed loss of heterozygosity (LOH) analysis with polymerase chain reaction at seven different loci surrounding the p27KIP1/CDKN1B gene at 12p13 and direct DNA sequencing analysis of all exons. Furthermore, the immunohistochemical expression of p27KIP1 and Ki-67 was investigated. Only two mutations in the sequence of p27KIP1/CDKN1B were detected, but the number of tumours showing LOH at 12p13 increased significantly with the parameters of tumour progression (pT level, P=0.018; Breslow index, P=0.01; Clark level, P<0.001), with a more aggressive tumour growth (radial versus vertical growth, P=0.018) and tumour subtype (superficial spreading melanomas versus nodular melanomas versus metastases, P<0.001). p27KIP1 protein expression decreased with the Clark level (P=0.026) and the pT level (P=0.045). No correlation between LOH affecting 12p13 and p27KIP1 protein decrease in melanomas was stated. This does not exclude the participation of p27KIP1/CDKN1B in p27KIP1 protein decrease, since protein expression is regulated at various cellular levels; but it could also suggest that other tumour suppressors are situated in the same region as p27KIP1/CDKN1B. Taken together, our data shows that loss of p27KIP1 protein expression and LOH at 12p13 contribute to tumour progression in melanoma.

Phosphoinositid-3-Kinase- (PI3-K) Expression

ZusammenfassungPhospoinositid-3-Kinase (PI3-K) ist ein heterodimeres Enzym und in die Regulation von Zellzyklus, Apoptose, Zelladhäsion und Zellmotilität eingebunden. Es wird als Proto-Onkogen in humanen Karzinomen diskutiert. In der vorliegenden Arbeit wurde die PI3-K-Expression in normalem Plattenepithel der Mundhöhle, Dysplasien, Carcinomata in situ, invasiven Karzinomen und Lymphknotenmetastasen immunhistologisch untersucht. Die stärkste Immunreaktivität für die regulatorische p85α- und die katalytische p110α-Untereinheit wurde in invasiven Tumoren und Metastasen gefunden. Carcinomata in situ zeigten eine herdförmige Reaktion, Dysplasien und normales Epithel reagierten überwiegend negativ. Zusätzlich hemmte der PI3-K-Inhibitor LY294002 die Proliferations- und Invasionsfähigkeit der humanen HNSCC-Zelllinie CAL-27 und induzierte die Apoptose in vitro.Unsere Ergebnisse deuten darauf hin, dass PI3-K ein Malignitäts- und Invasionsmarker beim Plattenepithelkarzinom des oberen Aerodigestivtraktes (HNSCC) ist. Wir schlagen vor, PI3-K als Proto-Onkogen in das vorläufige Mehrschrittkanzerogenesemodell des HNSCC aufzunehmen. PI3-K ist darüber hinaus ein potenzielles Ziel pharmakologischer Intervention.AbstractPhosphoinositide 3-kinase (PI3-K) is a heterodimeric enzyme involved in the regulation of mitogenesis, apoptosis, cell adhesion, and motility. PI3-K was suggested as a protooncogene in human cancer. To determine the expression of PI3-K during cancerogenesis and tumor invasion of HNSCC, we investigated normal and dysplastic epithelium of the oral cavity, squamous cell carcinoma and lymph node metastasis by immunohistochemistry. The strongest immunoreactivity for p85α and p110α was found in invasive tumors and their metastases. Carcinomas in situ showed a focal positivity. Dysplasias and normal epithelium reacted predominantly negatively. The PI3-K inhibitor LY294002 inhibited proliferation and invasion of the HNSCC cell line CAL-27 and induced apoptosis in vitro.Our data suggest PI3-K as a marker of malignancy and tumor invasion. We suggest including PI3-K in the multistep carcinogenesis model of HNSCC. In addition, PI3-K is a potential target for pharmacological intervention.

[Mucosal lesions in the larynx: predictive value of new imaging modalities for a histological diagnosis]

ZusammenfassungHintergrundOptische Kohärenztomographie (OCT) und Hochfrequenzultraschall sind vielversprechende Methoden in der Frühdiagnostik von Kehlkopftumoren. In der Literatur fehlen jedoch verlässliche Angaben zur Epitheldicke von präkanzerösen und kanzerösen Läsionen der Stimmlippen.Patienten und MethodenIn der vorliegenden Studie wurde die Epithelbreite bei verschiedenen gut- und bösartigen Stimmlippenveränderungen lichtmikroskopisch bestimmt.ErgebnisseDie morphometrische Epithelvermessung ergab eine zunehmende Verdickung des Epithels über die verschiedenen Schweregrade der Dysplasie bis zum mikroinvasiven Karzinom, wobei eine zusätzlich vorliegende Entzündung keinen wesentlichen Einfluss auf die Gesamtepitheldicke hatte. Bei der mittelgradigen Dysplasie wurde eine doppelte, bei der schweren Dysplasie und dem Carcinoma in situ eine dreifache und beim mikroinvasiven Karzinom sogar eine sechsfache Zunahme der mittleren Epitheldicke gegenüber der normalen Schleimhaut gemessen. Gutartige Läsionen wie Reinke-Ödeme, Polypen, chronische Laryngitis und Papillome hingegen wiesen lediglich eine leichte Epithelverdickung auf.SchlussfolgerungenDurch Bestimmung der Epitheldicke in vivo mittels OCT oder Hochfrequenzultraschall lassen sich möglicherweise Rückschlüsse auf die Dignität einer laryngealen Läsion ziehen.AbstractBackgroundOptical coherence tomography (OCT) and high-frequency ultrasound are promising new methods in the early diagnosis of laryngeal cancer. However, no reliable values are given in the literature for epithelial thickness in early laryngeal cancer and its precursor lesions of the vocal folds.Patients and methodsIn the present study, epithelial thickness in different benign and malignant lesions of the vocal folds was determined histologically using a normal white light microscope.ResultsThe vocal fold mucosa showed progressive thickening over the different grades of dysplasia up to microinvasive carcinoma, while additional inflammation did not have any significant influence on the total epithelial thickness. In moderate dysplasia, however, the mean thickness of the epithelium was found to be double that of normal mucosa, and in severe dysplasia and carcinoma in situ, as much as three times that of normal mucosa. In the presence of microinvasive carcinoma, the average thickness of the epithelium was found to be as much as six times that in healthy mucosa. On the other hand, in case of benign lesions such as Reinke’s edema, polyps, chronic laryngitis, and papillomas there was only slight epithelial thickening.ConclusionsDetermination of epithelial thickness by OCT or high-frequency ultrasound may allow conclusions on whether or not a laryngeal lesion is malignant.

Schleimhautveränderungen im Kehlkopf@@@Mucosal lesions in the larynx: Prädiktionswert neuerer bildgebender Verfahren für eine histologische Diagnose@@@Predictive value of new imaging modalities for a histological diagnosis

ZusammenfassungHintergrundOptische Kohärenztomographie (OCT) und Hochfrequenzultraschall sind vielversprechende Methoden in der Frühdiagnostik von Kehlkopftumoren. In der Literatur fehlen jedoch verlässliche Angaben zur Epitheldicke von präkanzerösen und kanzerösen Läsionen der Stimmlippen.Patienten und MethodenIn der vorliegenden Studie wurde die Epithelbreite bei verschiedenen gut- und bösartigen Stimmlippenveränderungen lichtmikroskopisch bestimmt.ErgebnisseDie morphometrische Epithelvermessung ergab eine zunehmende Verdickung des Epithels über die verschiedenen Schweregrade der Dysplasie bis zum mikroinvasiven Karzinom, wobei eine zusätzlich vorliegende Entzündung keinen wesentlichen Einfluss auf die Gesamtepitheldicke hatte. Bei der mittelgradigen Dysplasie wurde eine doppelte, bei der schweren Dysplasie und dem Carcinoma in situ eine dreifache und beim mikroinvasiven Karzinom sogar eine sechsfache Zunahme der mittleren Epitheldicke gegenüber der normalen Schleimhaut gemessen. Gutartige Läsionen wie Reinke-Ödeme, Polypen, chronische Laryngitis und Papillome hingegen wiesen lediglich eine leichte Epithelverdickung auf.SchlussfolgerungenDurch Bestimmung der Epitheldicke in vivo mittels OCT oder Hochfrequenzultraschall lassen sich möglicherweise Rückschlüsse auf die Dignität einer laryngealen Läsion ziehen.AbstractBackgroundOptical coherence tomography (OCT) and high-frequency ultrasound are promising new methods in the early diagnosis of laryngeal cancer. However, no reliable values are given in the literature for epithelial thickness in early laryngeal cancer and its precursor lesions of the vocal folds.Patients and methodsIn the present study, epithelial thickness in different benign and malignant lesions of the vocal folds was determined histologically using a normal white light microscope.ResultsThe vocal fold mucosa showed progressive thickening over the different grades of dysplasia up to microinvasive carcinoma, while additional inflammation did not have any significant influence on the total epithelial thickness. In moderate dysplasia, however, the mean thickness of the epithelium was found to be double that of normal mucosa, and in severe dysplasia and carcinoma in situ, as much as three times that of normal mucosa. In the presence of microinvasive carcinoma, the average thickness of the epithelium was found to be as much as six times that in healthy mucosa. On the other hand, in case of benign lesions such as Reinke’s edema, polyps, chronic laryngitis, and papillomas there was only slight epithelial thickening.ConclusionsDetermination of epithelial thickness by OCT or high-frequency ultrasound may allow conclusions on whether or not a laryngeal lesion is malignant.