Metka Volavšek

Cadherin–catenin complex and transcription factor Snail-1 in spindle cell carcinoma of the head and neck

Spindle cell carcinoma (SpCC) is a biphasic tumor composed of squamous cell carcinoma (SCC) and a malignant spindle cell component. There is mounting evidence that SpCC is a monoclonal neoplasm originating from a stem cell giving rise to both components. We tested the hypothesis that spindle cell phenotype might be related to the cadherin–catenin complex, which forms adherens junctions between cells. We analyzed the immunohistochemical expression of E- and N-cadherin, α-, β- and γ-catenin, and Snail-1, a transcription repressor of E-cadherin, in 30 cases of SpCC, and 30 cases of SCC of the head and neck. In SpCC, cadherin and catenin expression was similar in the SCC component, whereas in the spindle cell component, loss of E-cadherin and neo-expression of N-cadherin was found in 19 cases, loss of cadherins in seven, and their co-expression in four cases. Catenin expression were altered in 18 SpCCs. Snail-1 was found in 19 SpCC cases. In SCC, E-cadherin and catenins were expressed in all cases, and N-cadherin focally in five cases. Snail-1 was observed in the stroma. To summarize, in SpCC, there is an altered expression of the cadherin–catenin complex, associated with morphological transition from epithelial to spindle cell phenotype. These features are reminiscent of epithelial–mesenchymal transition (EMT). Our study thus indicates that EMT might play an important role in the pathogenesis of SpCC. This conclusion is further supported by our finding of Snail-1 expression, a potent inducer of EMT, in more than half SpCC cases.

Inflammatory myofibroblastic tumour of paranasal sinuses with fatal outcome: reactive lesion or tumour?

Inflammatory myofibroblastic tumours (IMTs) are clinicopathologically distinctive but biologically controversial entities, which have been described in the lungs, abdomen, retroperitoneum, and extremities, but rarely affect the head and neck region. IMT usually follows a benign clinical course after radical excision, but invasive, locally recurrent, and metastatic forms of abdominal and mediastinal IMT have also been described. This report describes a case of IMT of the paranasal sinuses with a fatal outcome. A 22 year old woman was admitted to hospital as a result of epistaxis. Computed tomography scan and magnetic resonance imaging showed an expansive process in the paranasal sinuses, extending into the nasal cavity, orbita, and endocranium. The tumour progressed despite several surgical procedures. Radiotherapy, corticosteroids, and chemotherapy were unsuccessful, and the patient died four years after diagnosis, as a result of extensive intracranial spread of the tumour. This is the first known case of an IMT of the head and neck region with a fatal outcome. It shows that the aggressive behaviour of IMTs is not limited to abdominal and mediastinal locations, and supports recent observations that at least a subset of IMTs represents true neoplasia rather than reactive myofibroblastic proliferation.

Evaluation of a new grading system for laryngeal squamous intraepithelial lesions—a proposed unified classification

To verify the applicability, reproducibility and predictive value of a proposed unified classification (amended Ljubljana classification) for laryngeal squamous intraepithelial lesions (SILs).

ATP2A3 gene is involved in cancer susceptibility

The sarco/endoplasmatic reticulum calcium-ATPase (SERCA) translocates Ca(2+) from cytosol to the lumen of the ER and thus regulates Ca(2+) homeostasis, perturbations of which have been suggested to contribute to cancer. We have previously detected an increased number of alterations in the ATP2A2 gene in various cancer types and in the ATP2A3 gene in head and neck squamous cell carcinoma. Here, we further analyzed the ATP2A3 gene in colon, lung, and CNS cancers. We identified a statistically significant increase of alterations in each (colon cancer, p=0.0052, lung cancer, p=0.0026, CNS tumors, p=0.0045) cancer type, and all 3 types together (p=0.0016). Epigenetic study of the ATP2A3 gene indicated an unchanged methylation status, whereas expression of the ATP2A3 gene was normal for exon 14 mutations and reduced in connection with a nucleotide change in intron VI in all studied cancer types. Identification of a significant number of alterations in cancer patients suggests that ATP2A3 is involved in increased cancer susceptibility in humans. The mostly normal expression and methylation status of the ATP2A3 gene, as well as the absence of somatic alterations, further suggest that the ATP2A3 gene may not act as a classical tumor suppressor gene, but rather haplo-insufficiency of this gene may be enough to change the cell and tissue environment in such a way to predispose to cancer development.

Alterations in genes encoding sarcoplasmic-endoplasmic reticulum Ca2+ pumps in association with head and neck squamous cell carcinoma

Recent studies have suggested that a perturbation of intracellular Ca(2+) homeostasis or signaling could contribute to cancer development. The purpose of this study was to evaluate whether germline variants of the ATP2A2 and ATP2A3 genes might act as susceptibility alleles in head and neck squamous cell carcinoma. In both genes, we identified eight different alterations in 11 patients with head and neck squamous cell carcinoma (11/79; P = 0.0002, odds ratio = 0.054, 95% confidence interval = 0.0069-0.4236). We also detected low expression level of both genes in connection with some of alterations, but could not correlate low expression level with methylation in the promoter region of either gene. The results suggest that Ca(2+) pumps of sarcoplasmic-endoplasmic reticulum are involved in an increased susceptibility to develop head and neck squamous cell carcinoma in humans.

Distribution and prognostic significance of cell cycle proteins in squamous carcinoma of the larynx, hypopharynx and adjacent epithelial hyperplastic lesions.

Alterations of cell cycle proteins contribute to the development and biological behaviour of malignant tumours. We evaluated the distribution and prognostic significance of immunohistochemically detected proteins p53, p21, Rb, and cyclin D1 in 101 laryngeal and hypopharyngeal squamous cell carcinomas (SCC) and adjacent epithelial hyperplastic lesions (EHL). Protein expression was correlated with tumour grade and stage. Varying patterns of protein expression were found in SCC. A significant correlation (p<0.05) was found between Rb expression and tumour grade. Different grades of EHL exhibited randomly distributed p53 and cyclin D1 positive cell clusters with no association to the pattern of their expression in SCC. Our study demonstrated derailment of cell cycle regulation in almost all cases of SCC of the larynx and hypopharynx. However, only cyclin D1 expression had an independent prognostic value for cancer-specific survival. The results also suggest that Rb gene inactivation, although rare, might be more important in the development of SCC than previously thought.

Low microsatellite instability and high loss of heterozygosity rates indicate dominant role of the suppressor pathway in squamous cell carcinoma of head and neck and loss of heterozygosity of 11q14.3 correlates with tumor grade

Loss of heterozygosity (LOH) and microsatellite instability (MSI) have been recognized as important events in squamous cell carcinoma of the head and neck (HNSCC), suggesting involvement of both suppressor and mutator pathways. We analyzed 153 HNSCC with 8 Bethesda reference panel markers and 14 microsatellite markers selected from chromosomal regions known to harbor either tumor-suppressor genes or oncogenes. A combination of multiplex fluorescence-based polymerase chain reaction and automatic fragment analysis was performed. LOH was observed in 78% of all tumors. 2% to 17% LOH frequency was observed with Bethesda reference panel markers comparing to higher 8% to 48% LOH in chromosomal areas 3p, 9p, 11q, and 17p. LOH of 11q14.3 correlated with tumor grade. The proportions of high- and low-MSI tumors were 3% and 10%, respectively, but no mutation was identified in MLH1 and MSH2 mismatch repair genes. These results indicate the dominant role of the suppressor in comparison with the mutator pathway in HNSCC carcinogenesis.

Extraneural metastases of anaplastic oligodendroglial tumors

Extraneural metastases of malignant gliomas are rare. According to the literature, they tend to appear in glioblastoma patients, but are exceptionally rare in anaplastic oligodendroglioma. We report on an anaplastic oligodendroglioma and an anaplastic oligoastrocytoma that metastasized to cervical lymph nodes and bones. Both patients were women aged 54 and 30 years, and the metastases appeared following craniotomy. In the first patient, metastases to cervical lymph nodes developed one year after surgery, and, despite adjuvant therapy, recurred in the same location several times. Fine needle aspiration biopsy (FNAB) of the cervical lymph node prior to neck dissection suggested a possible metastatic primitive neuroepithelial tumor. In the second case, metastases to the sacrum and femur developed after surgery for a recurrent anaplastic oligoastrocytoma. Our two cases reconfirm a rare but definite ability not only of glioblastoma but also of anaplastic oligodendroglioma, namely to metastasize to extraneural sites. It is important to bear this in mind, particularly in cases when the history of primary brain tumor is unavailable. In such instances, the correct diagnosis of the metastatic lesion may be extremely difficult if not impossible.

Adenosquamous Carcinoma of the Penis

Adenosquamous carcinoma is a rare, highly malignant tumor with histological features of squamous cell carcinoma and adenocarcinoma. Both growth patterns may be admixed or separated but they are always clearly distinct.’ To our knowledge this neoplasm, which occurs most frequently in the upper digestive tract,2.3 has been reported only recently in the penk4 CASE REPORT A 30-year-old man had a 10 X 8 mm. ulcerated lesion on the dorsal glans penis 5 months in duration. Local excision histologically revealed adenosquamous carcinoma, and partial amputation of the penis and bilateral regional lymphadenectomy were done. No residual neoplastic tissue was found in the penis. However, inguinal, iliac and obturator lymph nodes on the left side showed metastases. Diagnostic evaluation revealed no distant metastases. Bilateral inguinal lymph node metastases recurred 5 months later. At the same time significant dysphagia developed, although the patient had never experienced difficult swallowing. X-ray and esophagoscopy revealed 2 tumors in the proximal and distal thirds of the esophagus, respectively, that were histologically pure squamous cell carcinomas with keratinization. The patient received chemotherapy with local irradiation to the esophagus and inguinal region. During therapy, severe pancytopcnia and hemorrhagic diathesis developed, and he died of sepsis within 2 weeks. Histologically the penile tumor, which infiltrated the cavernous bodies, showed large areas of prly differentiated squamous cell carcinoma with several foci of keratinization (part A of figure). “his area of the tumor exhibited a continuous growth pattern with the carcinoma in situ of the surface epithelium. In deeper areas of the tumor glandular structures with mucus secreting cells were found (part B of figure). Squamous and glandular elements were observed in the lymph node metastases. Accepted for publication November 1, 1996. Autopsy revealed massive residual neoplastic involvement of inguinal soft tissues and diffuse infiltration of the esophageal wall with large ulcerations in the proximal and distal third of the esophagus. In addition, there were metastases in 1 paraesophageal lymph node and in several thoracic and lumbar vertebrae, as well as micrometastases in the left lung. Histologically all tumors were similar and showed features of squamow cell carcinoma with extensive keratinization. Glandular formations or much production was not observed. DISCUSSION The concurrence of adenosquamous carcinoma of the penis and squamous carcinoma of the esophagus in a young man is distinctly unusual and several explanations may be considered. In our opinion the clinical presentation and carcinoma in situ adjacent to invasive carcinoma suggest an origin in the glans surface epithelium and rule out the possibility of esophageal carcinoma metastatic to the penis. The occurrence of 2 independent primary carcinomas is possible but seems highly unlikely considering the young age of the patient.

Presence of activating KRAS mutations correlates significantly with expression of tumour suppressor genes DCN and TPM1 in colorectal cancer

BackgroundDespite identification of the major genes and pathways involved in the development of colorectal cancer (CRC), it has become obvious that several steps in these pathways might be bypassed by other as yet unknown genetic events that lead towards CRC. Therefore we wanted to improve our understanding of the genetic mechanisms of CRC development.MethodsWe used microarrays to identify novel genes involved in the development of CRC. Real time PCR was used for mRNA expression as well as to search for chromosomal abnormalities within candidate genes. The correlation between the expression obtained by real time PCR and the presence of the KRAS mutation was investigated.ResultsWe detected significant previously undescribed underexpression in CRC for genes SLC26A3, TPM1 and DCN, with a suggested tumour suppressor role. We also describe the correlation between TPM1 and DCN expression and the presence of KRAS mutations in CRC. When searching for chromosomal abnormalities, we found deletion of the TPM1 gene in one case of CRC, but no deletions of DCN and SLC26A3 were found.ConclusionOur study provides further evidence of decreased mRNA expression of three important tumour suppressor genes in cases of CRC, thus implicating them in the development of this type of cancer. Moreover, we found underexpression of the TPM1 gene in a case of CRCs without KRAS mutations, showing that TPM1 might serve as an alternative path of development of CRC. This downregulation could in some cases be mediated by deletion of the TPM1 gene. On the other hand, the correlation of DCN underexpression with the presence of KRAS mutations suggests that DCN expression is affected by the presence of activating KRAS mutations, lowering the amount of the important tumour suppressor protein decorin.