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1.
Head Neck ; 31(4): 503-12, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19156833

ABSTRACT

BACKGROUND: Sentinel node biopsy (SNB) has been proposed for staging of N0 neck in oral/oropharyngeal carcinomas. It is claimed that SNB may be superior to selective neck dissection (SND) with respect to quality of life (QOL) and postoperative morbidity. METHODS: Twenty-four patients after SNB and 25 patients after SND (levels I-III) were enrolled. QOL and psychosocial variables were assessed by the health-related EORTC QLQ-C30 questionnaire, the disease-specific EORTC QLQ-H&N35 module, the Hospital Anxiety and Depression Scale, and a fear of progression questionnaire. The functional status was evaluated by scores for cervical scar, extent of lymphedema (Miller score), sensory function, function of facial and hypoglossal nerve, cervical spine, and shoulder (Constant score). RESULTS: Health-related QOL measurement revealed no differences between the 2 groups. Disease-specific QOL scores showed fewer swallowing problems in SNB patients (p = .043). SNB patients felt less fear of progression, experienced significantly less impairment from cervical scars, and had less sensory dysfunction and better shoulder function. CONCLUSION: Functional outcome after SNB is significantly better than after SND; however, this is not reflected in the scores of QOL questionnaires.


Subject(s)
Carcinoma, Squamous Cell/surgery , Mouth Neoplasms/surgery , Neck Dissection/adverse effects , Oropharyngeal Neoplasms/surgery , Postoperative Complications , Quality of Life , Sentinel Lymph Node Biopsy/adverse effects , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Mouth Neoplasms/psychology , Neck , Oropharyngeal Neoplasms/psychology , Shoulder Pain/etiology , Surveys and Questionnaires
2.
Strahlenther Onkol ; 184(3): 157-62, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18330512

ABSTRACT

PURPOSE: The aim of this prospective study was to investigate how often and at which dose levels gustatory disturbances appear during radiotherapy of the tongue and to which extent permanent gustatory deficiencies occur. PATIENTS AND METHODS: The study included 44 patients treated by definitive irradiation for malignant head-and-neck tumors. In 22 patients the posterior two thirds of the tongue (group 1), and in the other 22 patients the entire tongue (group 2) were exposed to radiation. The control group comprised 30 patients with non-small cell lung cancer receiving definitive radiation therapy (group 3). The dose distribution in the tongue area was calculated using CT-based three-dimensional planning. Before, during and after irradiation the gustatory function was determined by means of gustometry and correlated with the corresponding results of enoral inspection and the patients' subjective statements on gustatory function. RESULTS: The gustatory ability of the control group was not affected, whereas patients in the locally irradiated groups in parallel with enoral mucositis suffered from loss of gustatory function after a total dose of 20 Gy with a maximum between 40 and 60 Gy. Supportive measures had little influence on acute side effects. The gustatory disturbances regressed within 8 weeks after radiotherapy in patients with partial-tongue irradiation and almost completely after 6 months in patients with entire-tongue irradiation. CONCLUSION: The severity of gustatory disturbances and the longer recovery time in patients with entire-tongue irradiation suggest an influence of the volume exposed. Therefore, reduction of the highly exposed tongue volume by intensity-modulated radiotherapy opens up possibilities for a reduction of this undesirable side effect.


Subject(s)
Head and Neck Neoplasms/radiotherapy , Taste Buds/radiation effects , Tongue Neoplasms/radiotherapy , Aged , Carcinoma, Non-Small-Cell Lung/radiotherapy , Data Interpretation, Statistical , Dose Fractionation, Radiation , Follow-Up Studies , Humans , Lung Neoplasms/radiotherapy , Middle Aged , Prospective Studies , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted , Recovery of Function , Risk Factors , Taste/radiation effects , Taste Buds/physiology , Time Factors , Tongue/radiation effects
3.
Hum Pathol ; 38(2): 228-38, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17020778

ABSTRACT

Protein microarrays are of increasing importance for high-throughput screening of fresh tissues. In our study, protein microarrays were generated by printing antibodies onto membranes to characterize protein profiles expressed by head and neck squamous cell carcinomas (HNSCCs). Cellular proteomes of 30 matched normal squamous epithelial cells and carcinoma specimens were analyzed after tissue microdissection using microarrays composed of 83 different antibodies. As controls, Western blot analysis and tissue microarrays (TMAs) containing 98 HNSCC specimens were used. Of the 83 proteins examined, 14 showed differential expression between HNSCCs and normal epithelium. The protein microarray approach revealed an upregulation of 8 proteins and a downregulation of 6 proteins. Bag-1, Cox-2, Hsp-70, Stat3, pescadillo, MMP-7 (matrilysin), IGF-2, and cyclin D1 were identified to be significantly upregulated, whereas suppressor of cytokine signaling 1, thrombospondin, TGF-beta1, Jun, Fos, and Fra-2 were downregulated. The differential expression of these proteins was confirmed using Western blot and TMA. Upon correlation of differentially regulated proteins with the clinicopathologic data of our patients, MMP-7 (matrilysin) was found to be associated with survival in univariate, but not multivariate, analysis. These data indicate that our protein arrays provide protein information in a systematic, reproducible, and also high-throughput fashion.


Subject(s)
Biomarkers, Tumor/analysis , Carcinoma, Squamous Cell/pathology , Head and Neck Neoplasms/pathology , Protein Array Analysis/methods , Blotting, Western , Carcinoma, Squamous Cell/metabolism , Cyclin D1/analysis , Head and Neck Neoplasms/metabolism , Humans , Immunohistochemistry , Kaplan-Meier Estimate , Matrix Metalloproteinase 7/analysis , Multivariate Analysis , Proteome/analysis , Reproducibility of Results , STAT3 Transcription Factor/analysis , Tissue Array Analysis
4.
Cytometry A ; 69(7): 582-7, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16807892

ABSTRACT

AIM: To evaluate slide-based cytometry in screening for and following up of carcinoma of the upper aerodigestive tract using swabs for a minimal-invasive approach. METHODS: Laser scanning cytometry (LSC) was used for multiparametric analysis of cells stained for cytokeratin and DNA to determine the DNA-index (DI) of the tumor cells. Histograms with 0.95 < DI < 1.05 and 1.9 < DI < 2.1 were defined as DNA euploid and any other DI as DNA aneuploid. After subsequent HE-staining, single cells were relocalized in order to document morphology. Conventional cytology was also performed on a subset of the slides. Routine histopathology of parallel biopsies served as gold standard in all cases. RESULTS: 115 swabs from 109 patients were obtained from the entire upper aerodigestive tract. 16 swabs were classified as insufficient for LSC. In the remaining 99 specimens, 1 benign lesion was misclassified as malignant, while 61 of the 75 malignant lesions were correctly identified. This corresponds to predictive values of 98.4% and 62.2% for the detection of malignant and benign samples by LSC. CONCLUSION: This pilot study demonstrates the validity of LSC screening for the identification of tumor malignancy in the upper aerodigestive tract from swab collected cytological material.


Subject(s)
Laser Scanning Cytometry/methods , Mouth Neoplasms/diagnosis , Respiratory Tract Neoplasms/diagnosis , Humans , Mouth Neoplasms/pathology , Pilot Projects , Predictive Value of Tests , Respiratory Tract Neoplasms/pathology
5.
Oncogene ; 24(44): 6699-708, 2005 Oct 06.
Article in English | MEDLINE | ID: mdl-16007169

ABSTRACT

The suppressors of cytokine signaling (SOCS) are inhibitors of cytokine signaling that function via the Janus kinase (JAK)/signal transducers and activators of transcription (STAT) pathway. Recently, methylation of SOCS-1 and SOCS-3 has been implicated in the tumorigenesis of liver and lung cancer. This study was performed to elucidate the role of SOCS-1 and SOCS-3 in squamous cell carcinoma of the head and neck (HNSCC) and its precursor lesions. HNSCC of 94 patients and corresponding normal mucosa, lymph node metastases as well as 16 high- and 21 low-grade squamous cell dysplasias were studied by using methylation-specific PCR (MSP) for the SOCS-1 and SOCS-3 promoter after microdissection. The presence of SOCS-3 mRNA transcripts was confirmed by semiquantitative real-time PCR, and the SOCS-3 protein was analysed immunohistochemically. SOCS-3 hypermethylation was found in 85/94 HNSCC (90%) and in 10/16 high-grade and 9/21 low-grade dysplasias (63 and 43%, respectively). SOCS-1 promoter hypermethylation was detected in 10/94 HNSCC samples (11%) and in 2/16 high-grade and 1/21 low-grade dysplasias (13 and 5%, respectively). Lymph node metastases exhibited an identical methylation status as the primary tumors. Methylation of the SOCS-3 promoter correlated with downregulation of SOCS-3 transcripts and protein expression in these tumors and various cell lines. In the cell lines tested, SOCS-3 and SOCS-1 transcripts increased upon treatment with the demethylation compound 5-aza-2-deoxycytidine (5-AZA-DC). Overexpression of wild-type SOCS-3 in carcinoma cells with methylated SOCS-3 resulted in the induction of apoptosis and growth suppression as well as downregulation of STAT3, bcl-2 as well as bcl-xL. Our data suggest that promoter methylation and subsequent transcript downregulation of SOCS-3 transcripts and, to a much lesser extent, SOCS-1 are involved in the multistep carcinogenesis of HNSCC. During its involvement in tumor growth, restoration of SOCS-3 may hold treatment potential for HNSCC.


Subject(s)
Carcinoma, Squamous Cell/metabolism , Cell Division/physiology , Head and Neck Neoplasms/metabolism , Repressor Proteins/metabolism , Transcription Factors/metabolism , Base Sequence , Carcinoma, Squamous Cell/pathology , DNA Methylation , DNA Primers , Head and Neck Neoplasms/pathology , Humans , Intracellular Signaling Peptides and Proteins , Methylation , RNA, Messenger/genetics , Repressor Proteins/genetics , Repressor Proteins/physiology , Suppressor of Cytokine Signaling 1 Protein , Suppressor of Cytokine Signaling 3 Protein , Suppressor of Cytokine Signaling Proteins , Transcription Factors/genetics , Transcription Factors/physiology , Tumor Cells, Cultured
6.
Eur J Cancer ; 41(3): 445-52, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15770781

ABSTRACT

The aim of our study was to evaluate slide-based cytometry in screening for laryngeal cancer using swabs a minimally invasive approach. Laser scanning cytometry (LSC) was used for the multiparametric analysis of cells stained for cytokeratin and DNA to determine the DNA-index (DI) of the tumour cells. Histograms with DI < 0.95, 1.05 < DI < 1.9, and 2.1 < DI were defined as DNA aneuploid. After subsequent haemotoxylin-eosin (HE)-staining, single cells were re-localised and an analysis by conventional cytology was performed. Additionally, routine histopathology of parallel biopsies was obtained in all cases. Fifty one swabs from 49 lesions were analyzed. Seven and 17 swabs, were classified as insufficient for LSC and cytology, respectively. One and two benign lesions, were misclassified as malignant, respectively. Out of 34 malignant lesions, LSC detected 25 and cytology 14. LSC was superior to cytology in all of the statistical parameters tested. This pilot study demonstrates the validity of LSC for the preoperative detection of malignancy in laryngeal tumours using swabs.


Subject(s)
Laryngeal Neoplasms/pathology , Algorithms , Biopsy, Needle/standards , DNA, Neoplasm/analysis , Humans , Laryngeal Neoplasms/surgery , Laser Scanning Cytometry/standards , Pilot Projects , Predictive Value of Tests , Preoperative Care/standards , Specimen Handling
7.
Dig Dis ; 22(3): 292-5, 2004.
Article in English | MEDLINE | ID: mdl-15753612

ABSTRACT

INTRODUCTION: Pancreatitis and parotitis share several etiological, pathohistological and functional similarities. It arose from recent pancreatitis research that some cases of chronic pancreatitis are associated with mutations of the serine protease inhibitor, Kazal type-1 (SPINK1). We tested the hypothesis that the pancreatitis-associated N34S mutation of SPINK1 is also a risk factor for chronic parotitis. METHODS: Reverse-transcriptase polymerase chain reaction was used to investigate SPINK1 transcription in the parotid gland. Forty-five blocks of formalin-fixed, paraffin wax-embedded tissues with chronic parotitis of unknown cause were analyzed for the SPINK1-N34S mutation. RESULTS: The SPINK1 gene is transcribed in the parotid gland. Two of the 45 patients (4.4%) with chronic parotitis carried the N34S mutation heterozygously. Of 82 healthy blood donors, 3 subjects (3.7%) were identified as carrying this mutation heterozygously (p = 0.83). CONCLUSION: The SPINK1-N34S mutation is not associated with chronic parotitis.


Subject(s)
Carrier Proteins/genetics , Parotid Gland/metabolism , Parotitis/genetics , Chronic Disease , DNA/genetics , Genetic Markers , Humans , In Vitro Techniques , Mutation/genetics , Parotid Gland/pathology , Parotitis/metabolism , Parotitis/pathology , RNA/genetics , Reverse Transcriptase Polymerase Chain Reaction , Trypsin Inhibitor, Kazal Pancreatic
8.
Lab Invest ; 83(12): 1771-6, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14691295

ABSTRACT

The v-raf murine sarcoma viral homolog B1 (BRAF) gene, one of the human isoforms of RAF, is activated by Ras, leading to cooperative effects in cells responsive to growth factor signals. Recently, somatic missense mutations of the BRAF gene have been detected in more than 66% of malignant melanomas of the skin. We analyzed 42 malignant melanomas of the uvea, 3 corresponding liver metastases, and 10 cutaneous melanomas for possible BRAF mutations: after microdissection, mutation analysis of BRAF and KRAS was performed. The expression of extracellular-regulated kinase 1 and 2 (ERK1/2), an important downstream point of convergence in the Ras-RAF-MEK-Erk pathway, was analyzed immunohistochemically. Interestingly, we failed to detect activating BRAF mutations in uvea melanomas and their corresponding liver metastases. There were no mutations of BRAF in corresponding non-neoplastic uvea specimens, although we detected three BRAF mutations in sporadic cutaneous melanoma that led to a substitution of valine by glutamic acid at position 599 (V599E). KRAS mutations were detected in 1 of 10 cutaneous melanoma but not in uveal or metastatic melanoma. Despite the lack of activating mutations in the BRAF gene, we identified constitutively activated ERK in almost all (86%) uveal melanoma tissues tested but not in corresponding normal retina or uveal cells. Our data indicate that BRAF gene mutations are rare to absent events in uveal melanoma. The finding of activated Erk suggests a causative role for MAPK activation in uveal melanoma independent of activating BRAF or RAS mutations.


Subject(s)
Melanoma/genetics , Mitogen-Activated Protein Kinase 1/biosynthesis , Mitogen-Activated Protein Kinases/biosynthesis , Mutation , Uveal Neoplasms/genetics , Humans , Melanoma/enzymology , Melanoma/secondary , Mitogen-Activated Protein Kinase 3 , Uveal Neoplasms/enzymology , Uveal Neoplasms/pathology
9.
Pathol Res Pract ; 199(6): 391-7, 2003.
Article in English | MEDLINE | ID: mdl-12924439

ABSTRACT

The multistep process of tumorigenesis has not been decoded to date, although numerous investigations into probable molecular changes have meanwhile been conducted. However, not only DNA changes or loss of alleles cause deregulation of gene function, but also epigenetic alterations (e.g. methylation) result in functional loss. The INK4a-ARF (CDKN2A) locus, located on chromosome 9p21, encodes two functionally distinct tumor suppressor genes, p14ARF and p16INK4a, which play active roles in the p53 and Rb tumor suppressive pathways. We therefore examined not only p16 and p14 proteins, but also alterations of the INK4a-ARF locus, including methylation and loss of heterozygosity in benign and malignant tumors of the head and neck (squamous cell carcinomas and pleomorphic adenomas). In benign pleomorphic adenomas, methylation of p14ARF was found in 1 out of 42 (2%) cases, whereas alterations of p16INK4a occurred in 12/42 (29%) pleomorphic adenomas. In HNSCC, methylation of p16INK4a occurred in 16 out of 50 (32%) carcinomas. P14ARF was found to be methylated in 8 out of 50 cases (16%). Our results demonstrate that alterations of the INK4a-ARF locus are frequent and important events not only in the carcinogenesis of malignant, but also in benign tumors.


Subject(s)
Adenoma, Pleomorphic/genetics , Carcinoma, Squamous Cell/genetics , Cyclin-Dependent Kinase Inhibitor p16/genetics , DNA, Neoplasm , Head and Neck Neoplasms/genetics , Tumor Suppressor Protein p14ARF/genetics , Chromosomes, Human, Pair 9/genetics , CpG Islands , DNA Methylation , DNA Mutational Analysis , DNA Primers , Genes, p53/genetics , Humans , Loss of Heterozygosity , Polymerase Chain Reaction , Retrospective Studies
10.
Oncogene ; 22(30): 4757-9, 2003 Jul 24.
Article in English | MEDLINE | ID: mdl-12879021

ABSTRACT

The RAF/MEK/ERK (MAPK) signal transduction cascade is an important mediator of a number of cellular fates including growth, proliferation and survival. The BRAF gene, one of the human isoforms of RAF, is activated by oncogenic RAS, leading to cooperative effects in cells responding to growth factor signals. This study was performed to elucidate a possible function of BRAF in squamous cell carcinoma of the head and neck (HNSCC). Mutations of BRAF and KRAS2 were evaluated in 89 HNSCC and corresponding normal mucosa by direct DNA sequencing analyses after microdissection. The results obtained were correlated with histopathological variables. Activating BRAF missense mutations were identified in 3/89 HNSCC (3%). KRAS2 mutations were found in five out of 89 (6%) HNSCC examined. There were no mutations of KRAS2 and BRAF in non-neoplastic mucosa. We failed to observe a correlation between BRAF or KRAS2 mutations and histopathological factors. Our data indicate that BRAF gene mutations are relatively rare events in HNSCC. Although uncommon, BRAF mutations may identify a subset of patients with HNSCC sensitive to targeted therapy.


Subject(s)
Carcinoma, Squamous Cell/genetics , Head and Neck Neoplasms/genetics , Mutation , Oncogene Proteins/genetics , Cell Division , Cell Survival , Humans , Mutation, Missense , Protein Isoforms , Protein Structure, Tertiary , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins B-raf , Proto-Oncogene Proteins p21(ras) , Sequence Analysis, DNA , Signal Transduction , ras Proteins
11.
Cytometry B Clin Cytom ; 53(1): 20-5, 2003 May.
Article in English | MEDLINE | ID: mdl-12717687

ABSTRACT

BACKGROUND: To minimize hospitalization and morbidity for a patient with a solid tumor of a salivary gland, malignancy must be confirmed or excluded as soon as possible. This information cannot be obtained preoperatively by existing standard procedures. Minimal-invasive approaches with adequate diagnostic analysis represent a promising precondition for optimized therapy. METHODS: For fine needle aspirate biopsies (FNABs), laser scanning cytometry (LSC) offers a semi-automated slide-based technology for objective and quantitative analysis. We have established an assay for FNABs from salivary gland tumors. FNAB cells were stained for cytokeratin and DNA followed by LSC analysis. The cells were subsequently HE-stained and were relocalized on the slide. The LSC analysis quantitatively determines the DNA index (DI) of the tumor cells taking leukocytes as internal DNA diploid standard. Histograms with 0.95 < DI < 1.05 and 1.9 2.5 (i.e., 5c exceeding rate, 5cER) was calculated. Samples with DNA aneuploid peaks or with 5cER > 5% were classified as malignant. Routine histopathology was performed as a control. RESULTS: FNABs from 51 solid salivary gland tumors (41 parotid gland, six submandibular, four parapharyngeal) were analyzed with this assay. Eleven of 14 malignant tumors were DNA aneuploid by LSC analysis. All benign tumors showed diploid DNA content. The positive predictive value for malignancy was 1.0, the negative predictive value was 0.93, the correlation with routine histopathology was highly significant (p = 7.6 x 10(-9), Fisher's exact test). The calculated specificity of LSC analysis was 1.0 and the sensitivity was 0.79. CONCLUSIONS: This pilot study demonstrates the validity of slide-based cytometry for the preoperative prediction of malignancy in solid tumors being inaccessible for incision biopsy but suitable for FNABs such as those of the parotid gland.


Subject(s)
Adenoma, Pleomorphic/pathology , Microscopy, Confocal , Parotid Neoplasms/pathology , Adenoma, Pleomorphic/genetics , Aneuploidy , Biopsy, Needle , DNA, Neoplasm/analysis , Humans , Parotid Neoplasms/genetics , Pilot Projects , Ploidies , Predictive Value of Tests , Prognosis , Submandibular Gland Neoplasms/genetics , Submandibular Gland Neoplasms/pathology
12.
Virchows Arch ; 441(5): 428-36, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12447671

ABSTRACT

The tumor-suppressor protein p53 has recently been shown to belong to a family that includes two structurally related proteins, p63 and p73. In contrast to p53, p63 and p73 play an essential role in epithelial development, stem cell identity and cellular differentiation. Salivary gland tumors carry a wide spectrum of histopathological forms, which may share a common single-cell origin from the epithelial progenitor basal duct cells and have a different tendency of malignant progression. This study was performed to examine the expression of p53, p63, and p73 in benign salivary gland tumors. Expression and mutation of p53, p73, and p63 were examined by direct DNA sequencing, reverse transcription PCR using isoform-specific primers, and by immunohistochemistry in normal parotid tissue ( n=10), and various tumors of the salivary gland (42 pleomorphic adenomas, 12 myoepitheliomas, 8 basal cell adenomas, 5 oncocytomas, 5 canalicular adenomas, and 20 adenolymphomas). In normal parotid tissue the expression of p63 and p73 was restricted to few basal and myoepithelial cells. Ductal luminal and acinus cells were completely negative for the expression of all three family members. In contrast, in salivary gland tumors, strong nuclear staining for p63 and p73 was observed. Myoepithelial and basaloid cells and the basal epithelial layer of adenolyphomas and oncocytomas were positive for p63 and also, to a lesser extent, to p73. Mutations of p53 were detected in 4 of 42 (10%) pleomorphic adenomas, in 3 of 12 (25%) myoepitheliomas, and in 1 of 8 (13%) basal cell adenomas but not in other tumors. We failed to detect specific mutations of p63 and p73. Using isoform-specific PCR, we found that all isoforms of p63 were expressed in normal parotid tissue whereas the pleomorphic adenomas, myoepitehliomas, and basal cell adenomas dominantly expressed the transactivation-incompetent truncated isoforms. Our data indicate that p63 and p73 are upregulated in salivary gland tumors and may serve as a marker of epithelial and myoepithelial progenitor cells in salivary glands. The prevalence of p53 mutations and the observation of the expression of DeltaNp63 isoforms only in pleomorphic adenomas, myoepitheliomas, and also basal cell adenomas may reflect their possible malignant potential.


Subject(s)
Adenoma, Pleomorphic/metabolism , DNA-Binding Proteins/biosynthesis , Membrane Proteins , Nuclear Proteins/biosynthesis , Parotid Neoplasms/metabolism , Phosphoproteins/biosynthesis , Trans-Activators/biosynthesis , Tumor Suppressor Protein p53/biosynthesis , Adenoma, Pleomorphic/pathology , DNA Mutational Analysis , DNA Primers/chemistry , DNA, Neoplasm/analysis , DNA-Binding Proteins/genetics , Fluorescent Antibody Technique, Indirect , Gene Expression Profiling , Genes, Tumor Suppressor , Immunoenzyme Techniques , Nuclear Proteins/genetics , Oligonucleotide Array Sequence Analysis , Parotid Neoplasms/pathology , Phosphoproteins/genetics , RNA, Messenger/metabolism , RNA, Neoplasm/analysis , Retrospective Studies , Reverse Transcriptase Polymerase Chain Reaction , Trans-Activators/genetics , Tumor Protein p73 , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Proteins
13.
J Pathol ; 198(3): 326-34, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12375265

ABSTRACT

Pleomorphic adenomas of the parotid gland are benign tumours composed of epithelial and mesenchymal cells. The INK4a-ARF (CDKN2A) locus on chromosome 9p21 encodes two tumour suppressor proteins, p16(INK4a) and p14(ARF), which act as upstream regulators of the Rb-CDK4 and p53 pathways. To study the contribution of each pathway in pleomorphic adenomas, this study analysed alterations of p14(ARF), p16(INK4a), p53, and pRb in these tumours. After microdissecting the different histological components, 42 pleomorphic adenomas of the parotid gland were analysed for INK4a-ARF inactivation by DNA sequence analysis, methylation-specific PCR (MSP), restriction enzyme-related polymerase chain reaction (RE-PCR), mRNA expression, microsatellite analysis, and immunohistochemistry. In addition, microdeletion of p14(ARF) and p16(INK4a) were assessed by differential PCR. The status of p53 and Rb was examined by direct sequencing and immunohistochemistry. Using microdissection, it was possible to examine the tumour components, i.e. epithelial, mesenchymal, and transitional, separately after immunohistochemical identification. Methylation of p14(ARF) was found in 1/42 cases and alterations of p16(INK4a) occurred in 12/42 of pleomorphic adenomas, which correlated with loss of mRNA transcription. Microdeletions or specific mutations of either exon were not detected. Methylation was detected exclusively in the epithelial and transitional components and not within the mesenchymal part of the tumour. p53 mutations were detected in 4/42 adenomas, also occurring solely in the epithelial components of the tumours. pRb was detected immunohistochemically in 40/42 adenomas. In normal, corresponding parotid tissue, p14(ARF), p16(INK4a), p53, and pRb alterations were not observed. The observation that alterations of p14(ARF) and p16(INK4a), and also p53 mutations, occurred exclusively in the epithelial and transitional components of pleomorphic adenoma supports the theory that these areas are prone to malignant transformation to carcinoma in adenoma.


Subject(s)
Adenoma, Pleomorphic/genetics , Cyclin-Dependent Kinase Inhibitor p16/genetics , Parotid Neoplasms/genetics , Tumor Suppressor Protein p14ARF/genetics , Adenoma, Pleomorphic/metabolism , Chromosomes, Human, Pair 9/genetics , DNA Methylation , DNA Mutational Analysis , DNA, Neoplasm/genetics , Genes, p53 , Humans , Microsatellite Repeats , Mutation , Neoplasm Proteins/metabolism , Parotid Neoplasms/metabolism , RNA, Messenger/genetics , RNA, Neoplasm/genetics , Retinoblastoma Protein/metabolism , Retrospective Studies , Reverse Transcriptase Polymerase Chain Reaction
14.
Virchows Arch ; 441(2): 133-42, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12189502

ABSTRACT

BACKGROUND: The INK4a-ARF (CDKN2A) locus, located on chromosome 9p21, encodes two functionally distinct tumor suppressor genes, p14(ARF) and p16(INK4a), that play active roles in the p53 and Rb tumor suppressive pathways, respectively. We analyzed the alterations of p14(ARF), p16(INK4a) and p53 to study the contribution of each pathway in tumorigenesis of 29 patients with primary and consecutive (second primary) squamous cell carcinoma of the head and neck (HNSCC), with a total of 68 carcinomas. METHODS: After microdissection, the DNA of 29 primary and 39 consecutive squamous cell carcinomas was analyzed for INK4a-ARF inactivation and p53 mutation by means of DNA sequence analysis, methylation-specific polymerase chain reaction (MSP), restriction-enzyme-related polymerase chain reaction (RE-PCR), multiplex RT-PCR and immunohistochemistry. In addition, microdeletions of p14(ARF) and p16(INK4a) were assessed using differential PCR. RESULTS: Altogether inactivation (methylation, loss of heterozygosity and mutation of exon 1beta) of p14(ARF) was found in 29 of all 68 (43%) carcinomas, with a significant difference in primary [8 of 29 (28%)] relative to second primary carcinomas [21 of 39 (54%)]. Methylation of p16(INK4a) occurred in 22 of 68 (32%) carcinomas with an even distribution among primary and consecutive tumors. Only two (secondary) carcinomas showed simultaneous promoter methylation of p14(ARF) and p16 (INK4a). Mutations of p53 were found in 32 of 68 HNSCCs (44%), evenly distributed among primary and recurrent carcinomas. p14(ARF) alterations showed no relationship to p53 mutations. CONCLUSIONS: Our data indicate that the INK4a-ARF-/p53 pathway was disrupted in 58 of 68 (84%) primary and recurrent tumors, either by p53 mutations or by INK4a-ARF inactivation. p14(ARF) methylation occurred independently of p16(INK4a) alterations and showed no correlation to p53 mutations. The significantly higher rate of p14(ARF) alterations in recurrent (respective second primary) carcinomas suggests a further acquired genetic aberration during the development of the recurrent carcinomas.


Subject(s)
Carcinoma, Squamous Cell/genetics , Cyclin-Dependent Kinase Inhibitor p16/genetics , Genes, p53 , Head and Neck Neoplasms/genetics , Neoplasms, Second Primary/genetics , Tumor Suppressor Protein p14ARF/genetics , Biomarkers, Tumor/analysis , Carcinoma, Squamous Cell/chemistry , Carcinoma, Squamous Cell/secondary , Cyclin-Dependent Kinase Inhibitor p16/analysis , DNA Methylation , DNA Primers/chemistry , DNA, Neoplasm/analysis , Head and Neck Neoplasms/chemistry , Head and Neck Neoplasms/pathology , Humans , Immunohistochemistry , Mutation , Neoplasm Recurrence, Local , Neoplasms, Second Primary/chemistry , Neoplasms, Second Primary/pathology , RNA, Messenger/analysis , RNA, Neoplasm/analysis , Reverse Transcriptase Polymerase Chain Reaction , Tumor Suppressor Protein p14ARF/analysis
15.
Int J Cancer ; 99(1): 22-8, 2002 May 01.
Article in English | MEDLINE | ID: mdl-11948487

ABSTRACT

The tumour-suppressor protein p53 belongs to a family that includes 2 structurally related proteins, p63 and p73. Because of their structural homology, it has been hypothesized that both homologues serve as "spare mechanisms" in p53 mutations to regulate the cell cycle by inducing apoptosis. We investigated the mutational and protein expression status of p53 in correlation to its homologues, p73 and p63, in primary and recurrent squamous cell carcinomas of the head and neck (HNSCC) and corresponding nonneoplastic mucosa. Expression and mutation of p53 and its homologues p63 (including the 2 major isotypes TAp63 and DeltaNp63) and p73 was examined by direct DNA sequencing and immunohistochemistry in 29 primary and 39 recurrent (secondary) HNSCCs after microdissection. Our results were correlated with pathohistologic stage and grade. p53 mutations were detected in 32/68 (47%) carcinomas of 17 patients, with a discordant mutation pattern of primary and consecutive tumours in all cases. Positive immunostaining for p63 was found in 55/68 (81%) carcinomas of 29 patients. Immunohistochemistry revealed p73 protein expression in 32/68 (47%) tumours. In normal mucosa, p63 and p73 were expressed in 40/68 (59%) and 12/68 (18%) cases, respectively. We failed to detect specific mutations of p73 or p63 in primary and recurrent carcinoma of the head and neck. p73 and p63 were rarely mutated in HNSCC, but both were expressed in a subset of tumours. The lack of correlation between p73/p63 and p53 protein expression suggests that neither p73 nor p63 can replace p53 when it is mutated.


Subject(s)
Carcinoma, Squamous Cell/metabolism , DNA-Binding Proteins/genetics , Head and Neck Neoplasms/metabolism , Membrane Proteins , Neoplasm Recurrence, Local/metabolism , Nuclear Proteins/genetics , Phosphoproteins/genetics , Trans-Activators/genetics , Tumor Suppressor Protein p53/genetics , Carcinoma, Squamous Cell/genetics , Carcinoma, Squamous Cell/pathology , DNA Mutational Analysis , DNA Primers/chemistry , DNA, Neoplasm/analysis , DNA-Binding Proteins/metabolism , Gene Expression , Genes, Tumor Suppressor , Head and Neck Neoplasms/genetics , Head and Neck Neoplasms/pathology , Humans , Immunoenzyme Techniques , Neoplasm Recurrence, Local/genetics , Neoplasm Recurrence, Local/pathology , Neoplasm Staging , Nuclear Proteins/metabolism , Phosphoproteins/metabolism , RNA, Messenger/metabolism , RNA, Neoplasm/genetics , Reverse Transcriptase Polymerase Chain Reaction , Trans-Activators/metabolism , Transcription Factors , Tumor Protein p73 , Tumor Suppressor Protein p53/metabolism , Tumor Suppressor Proteins
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