Deregulation of p53/survivin apoptotic markers correlated to PTEN expression in pterygium neoplastic cells.

PURPOSE: Pterygium is a distinct clinicopathological entity characterized by degenerated and neoplastic-like features. Concerning its rise on normal conjunctiva epithelia, the role of specific gene deregulations including apoptotic/anti-apoptotic factors and significant suppressor genes in signaling transduction pathways is under investigation. In the current study, we co-analyzed p53, survivin and PTEN proteins in pterygia and normal conjunctiva. METHODS: Using a liquid-based cytology assay, 50 cell specimens were obtained by a smooth scraping on conjunctiva epithelia and fixed accordingly. Among them, 38 were pterygia and the remaining (n=12) normal epithelia (control group). Immunocytochemistry assays were implemented on the corresponding slides by applying ani-p53, survivin, and PTEN antibodies. Digital image analysis was performed for evaluating objectively the corresponding immunostaining intensity levels. RESULTS: The majority of the examined pterygia cases overexpressed the markers p53:22/38-57.9%, survivin:30/38-78.9%, and PTEN:25/38-65.7%. Interestingly, overall p53/PTEN co-expression was found to be statistically significant (p=0.022). CONCLUSIONS: Survivin overexpression leads to an increased anti-apoptotic activity playing a central molecular role in the pathogenesis and progression of pterygia. Furthermore, although p53 expression is observed in these lesions, its impact seems to be low compared to survivin's influence on them. Additionally, the role of PTEN in the process is potentially significant providing a suppressor balance to the p53/ survivin complex.

HPV infection in oropharyngeal squamous cell carcinomas: correlation with tumor size.

PURPOSE: Human papillomavirus (HPV) is implicated in carcinogenesis of a variety of epithelia, including oropharyngeal and laryngeal. High risk (HR) HPV persistent infection in head and neck squamous cell carcinomas (HNSCC) is a significant event, but its influence regarding the prognosis and survival in these patients remains under consideration. Our aim was to analyze a series of oropharyngeal (OP) SCCs at the HPV DNA level, correlating them to the survival status of the corresponding patients. METHODS: Using HPV DNA polymerase chain reaction (PCR) microarray technology, 28 formalin-fixed, paraffinembedded primary OPSCCs were cored and analyzed. RESULTS: Positive DNA amplicons for HPV infection were detected in 3 SCC cases (sub types: HPV 31/35/70). Interestingly, HPV persistent infection was associated with larger tumors (p=0.029) which also affected survival status (p=0.007) in the corresponding patients. Overall survival was also significantly dependent on the stage of the malignancies (p=0.022). Furthermore, tumor size was significantly and negatively correlated with age (p=0.015), meaning that younger patients will probably develop larger tumors. CONCLUSIONS: HPV-depended OPSCCs - although not so common as the laryngeal ones, but still not so rare in the rural population in Greece - are characterized by a combination of specific features. Our results showed that survival was adversely effected by the stage of the disease and tumor size and indirectly by the presence of HPV - especially in young adults - while the combined surgery/radiotherapy/ chemotherapy therapy seems to prolong survival. Additionally, HPV co-existence seems to be associated with larger tumors and poor survival.

Numerical Imbalances of Chromosome 7 in Oral Squamous Cell Carcinoma.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is an aggressive neoplasm. Many chromosomal and gene alterations have been identified in OSCC, including structural and numerical changes. In this study, we implemented a molecular assay of chromosome 7 (Chr7) in order to investigate the level of its numerical instability in OSCC. MATERIALS AND METHODS: Using tissue microarray technology, 30 primary OSCCs were cored and re-embedded into one recipient block. Chromogenic in situ hybridization assay was performed based on Chr7 centromeric probedetection. RESULTS: Chr 7 numerical analysis detected polysomy (trisomy/ tetrasomy) in 4/30 (13.3%) of the examined tissue OSCC cores. Statistical significance was assessed correlating Chr7 numerical aberrations with stage (p=0.015), especially detected in cases not related to human papillomavirus (HPV) (p=0.01). CONCLUSION: Although Chr7 polysomy is a relatively rare gross genetic event in OSSC, it affects their biological behavior leading toa progressively aggressive phenotype (advanced stage). Furthermore, Chr7 polysomy is observed more frequently in non-viral (HPV) cases.

Molecular aspects in HPV-dependent laryngeal and oropharyngeal carcinoma.

Human papillomavirus (HPV)-mediated cervical carcinogenesis represents a well analyzed model of viral implication in epithelial malignant transformation. Mechanisms of high risk (HR) HPV-related infection seem to demonstrate a similar action regarding its implication in head and neck (HN) carcinomas, predominantly in squamous cell carcinoma (SCC) histological type. The prevalence of HR HPV subtypes - mainly HPV16 - is characterized by a broad geographic heterogeneity. Furthermore, HPV-associated HNSCCs demonstrate differences regarding sexual, molecular, epidemiological, and prognostic features compared to alcohol and tobacco dependent ones. Based on these differences, HPV-derived HNSCC appear to be a specific well-defined entity mostly affecting young to middle-aged - male mainly - non-smokers. This is a strong reason of detecting an increased HR-HPV DNA levels -due to viral transmission - in oropharyngeal and laryngeal anatomic regions. Additionally, different response rates to chemoradiation and targeted therapeutic regimens are another significant field for handling these SCC malignancies in the corresponding patients. In the current special article we explored the role of HPV-related carcinogenesis in oropharyngeal and laryngeal SCC focused on the latest molecular aspects.

ki-67 and Topoisomerase IIa proliferation markers in colon adenocarcinoma.

Aberrant cell proliferation is a major cause in the development and progression of carcinogenic process. Epithelia characterized by increased mitotic rates accumulate easily gross numerical and structural chromosomes (polysomy/aneuploidy) and specific gene (deletions, amplifications, point mutations, translocations) deregulations that lead to their progressive neoplastic and finally malignant transformation. Molecules that are critical for evaluating the proliferation status of the corresponding tissues include mainly ki-67 (cytogenetic band: 10q26.2), and also Topoisomerase IIa/Topo IIa (cytogenetic band: 17q21.2). Both of them demonstrate different expression patterns in every cell cycle phase and their estimated expression as Nuclear Labeling Index (NLI) is a very useful tool for assessing the aggressiveness of the examined pre- and malignant tissues. In fact, ki-67 expression increases as a cell progresses through the cell cycle, with highest expression being seen in G2/M phase cell, whereas Topo IIa is expressed in proliferating cells in the late S phase with a peak in G2-M phases. Concerning colon adenocarcinoma, high expression levels of them seem to correlate with advanced disease and also with modified response rates to specific chemotherapeutic agents, such as doxorubicin, an inhibitor of Topo IIa. In the current molecular review we explored the role of these proliferative markers in colon adenocarcinoma and their influence in the tumor biological behavior.

Deregulation of PTEN Expression in Laryngeal Squamous Cell Carcinoma Based on Tissue Microarray Digital Analysis.

BACKGROUND/AIM: Phosphatase and tensin homolog (PTEN) (gene locus: 10q23.3) -a tumor suppressor gene- is deleted, mutated or epigenetically hyper-methylated in a variety of malignancies. PTEN acts as a negative regulator in PI3K/AKT/mTOR signaling transduction pathway. Our aim was to investigate PTEN protein expression patterns in laryngeal squamous cell carcinomas (LSCC). MATERIALS AND METHODS: Using tissue microarray technology, fifty (n=50) primary LSCCs were cored and re-embedded into one recipient block. Immunohistochemistry and digital image analysis were implemented for evaluating protein expression levels. RESULTS: Abnormal protein expression (low to negative staining intensity values) was observed in 28/50 (56%) tissue cores. Overall PTEN expression was associated with the anatomical region of the malignancies (p=0.039), whereas a borderline correlation with the differentiation grade was also assessed (p=0.05). CONCLUSION: Aberrant expression of PTEN tumor-suppressor gene in LSCCs seems to affect their biological behavior. Well-differentiated tumors express moderate to high protein levels, an evidence of normal gene function, whereas loss of its expression correlates with a progressive tumor dedifferentiation. Additionally, loss of its expression is detected more frequently in specific anatomical regions of the larynx (glottis, predominantly, and partially supraglottis).

DNA mismatch repair deficiency in lung and oral cavity carcinomas: the role of histogenetic origin.

DNA mismatch repair system (DNA MMR) is a crucial genetic mechanism for DNA homeostasis in prokaryotic and eukaryotic cells. During DNA replication and also recombination, point intra-nucleotide errors including base deletion, insertion, and mis-incorporation happen. These raised abnormalities in the newly synthesized DNA strand could affect negatively the stability of the molecule and the function of the corresponding genes. DNA MMR proteins prevent these errors by recognizing and repairing them, securing directly the normal anatomy of the DNA double strand and indirectly the expression of the genes. Specific genomic alterations - mutations, loss of heterozygosity (LOH), or promoter hypermethylation - regarding the MMR genes (human homologues) hMLH1, hMSH2, hMSH3, hMSH6, hPMS1 and hPMS2 modify negatively their expression leading to loss of their function in repairing the corresponding base to base errors. The result known as microsatellite instability (MSI) was initially recognized in colonic carcinoma, especially in its inherited aspect - the Lynch syndrome -, the most common form of hereditary colon carcinoma. Since then, acquired deficiencies in specific DNA MMR genes have been detected in a broad spectrum of malignancies including different anatomic regions and histologies such as stomach, prostate, esophageal, endometrial, lung and head & neck. In the current special review we explored the role of DNA MMR deficiency in lung and oral cavity carcinomas in order to identify similarities and differences regarding the corresponding genes alterations.

mTOR deregulation in oral cavity squamous cell carcinoma.

Signal transduction pathways consist of a variety of inter- and intra-cellular molecules. They act as supporting mechanisms for cell survival and homeostasis. Among them, the phosphatidylinositol 3-kinase (PI3K)/tumor suppressor phosphatase and tensin homologue deleted on chromosome ten (PTEN)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway plays a crucial role in regulating normal cell growth based on growth factor receptors (GFRs) interaction, including epidermal GFR (type II-HER2) and insulin GFR (IGF). mTOR protein acts as a serine-threonine kinase that belongs to the PI3K-related kinase family. It mediates protein and lipid synthesis, mitochondrial metabolism, biogenesis, proliferation and also negatively regulates autophagy. Two distinct multiprotein complexes have been mainly identified and cloned: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). mTOR is deregulated predominantly due to mutations, deletions, loss of heterozygosity (LOH) or abnormal phosphorylation of the upstream molecules inside the current pathway. Pure mTOR mutations are very rare. Development of specific inhibitors at the basis of targeted therapeutic strategies such as rapamycin (rapalogs) is an evolution in handling patients with mTOR abnormal overactivity. In the current special article we explored the role of the gene deregulation leading to abnormal protein expression in oral cavity squamous cell carcinoma (SCC).

Topoisomerase I deregulation in laryngeal squamous cell carcinomas based on tissue microarray analysis.

PURPOSE: Topoisomerases (types: I/IIa-b/IIIa-b) represent a super-family of nucleic enzymes involved in the DNA replication, transcription, recombination, and also chromosome topological formation. Topoisomerase's I (Topo I- gene location: 20q12) aberrant expression is a frequent genetic event in a variety of solid malignancies. Topo I inhibition promotes cell death due to DNA damage and for this reason it is a target for specific targeted chemotherapy (camptothecin, topotecan, irinotecan). Our aim was to investigate the role of abnormal Topo I protein expression in laryngeal squamous cell carcinomas (LSCC) in which there are very limited data regarding the influence of the marker. METHODS: Using tissue microarray (TMA) technology, 50 formalin-fixed, paraffin-embedded primary laryngeal SCCs were cored and re-pembedded into one recipient block. Immunohistochemistry was performed using anti- Topo I antibody. Digital image analysis was also implemented for evaluating objectively the protein expression levels on the corresponding stained nuclei. RESULTS: Topo I protein overexpression (moderate to high staining intensity values) was observed in 32/50 (64%) tissue cores, whereas low expression rates were detected in 18/50 (36%) cases. Topo I overall expression was strongly associated with the differentiation grade of the examined tumors (p=0.021). No other statistical correlations were identified. CONCLUSIONS: Topo I overexpression is observed in a significant subset of LSCCs affecting the level of differentiation in them. Additional molecular studies focused on the mechanism of Topo I gene/protein deregulation (i.e. amplification, abnormal epigenetic promoter methylation, mRNA aberrant expression) are necessary discriminating the eligible patients for applying specific chemotherapeutic strategies based on anti-Topo I agents.

Chromosome 7 Multiplication in EGFR-positive Lung Carcinomas Based on Tissue Microarray Analysis.

BACKGROUND/AIM: Epidermal growth factor receptor (EGFR) over-activation is observed in significant proportions of non-small cell lung carcinomas (NSCLC). Our aim was to investigate the role of chromosome 7 multiplication with regard to its influence in EGFR expression, combined or not with gene amplification. MATERIALS AND METHODS: Using tissue microarray technology, fifty (n=50) primary NSCLCs were cored and re-embedded into the final recipient block. Immunohistochemistry (IHC) and also chromogenic in situ hybridization (CISH) were performed. RESULTS: EGFR expression at any level was detected in 40/50 (80%) cores. Over-expression was observed in 23/40 (57.5%) cases. Gene amplification was identified in 11/50 (22%) cases whereas chromosome 7 polysomy in 8/50 (16%) cases. Pure chromosome 7 multiplication alone led to low or moderate levels of expression. Overall EGFR expression was correlated with gene (p=0.001) and interestingly with chromosome 7 centromere numerical imbalances (p=0.004). CONCLUSION: EGFR expression is associated not only with amplification, but also with chromosome 7 centromere multiple copies. Chromosome 7 multiplication -due to centromere region amplification or true polysomy- is critical for applying monoclonal antibody targeted therapeutic strategies excluding the pure non-amplified cases.

Novel molecular and metabolic aspects in osteosarcoma.

Osteosarcoma (OS) is the most frequent bone-forming malignancy in children and adolescents. Concerning its molecular landscape, there is no a direct relationship with a specific gene, but a combination of genetic events. A broad spectrum of activated oncogenes and downregulated suppressor genes has been already explored and considered crucial for its progressive pathogenesis. Mechanisms of gene deregulation include amplifications, point mutations, allelic losses and also epigenetic abnormalities such as aberrant promoter methylation. Although a significant progress in understanding the molecular nature of the OS has been achieved, its aggressive phenotype - characterized by high metastatic potential - remains unexplored. Novel targeted therapeutic strategies include monoclonal antibodies (mABs) and also tyrosine-kinase inhibitors (TKIs). Additionally, sophisticated and innovative diagnostic techniques, such as 18 fluorodeoxyglucose positron emission tomography plus CT (18F-FDG/PET/CT), provide critical data regarding its biological behavior. In the current paper, we present novel molecular and metabolic advances by analyzing OS genetic profile and biochemical microenvironment.