Impact of Amplified Oncogenes on Salivary Gland Carcinomas.

In normal epithelia, proto-oncogenes regulate critical intra- or intercellular functions, including cell growth and proliferation, apoptosis, and signaling transduction from the cell periphery (extracellular space) to the nucleus mediated by different pathways. Oncogenes are the mutated or amplified forms of the corresponding proto-oncogenes that are crucially involved in cell neoplastic and malignant transformation during carcinogenesis. Salivary gland carcinomas (SGCs) demonstrate a variety of histogenetic types. They are characterized by a broad spectrum of chromosomal and gene alterations. In particular, amplifications in specific genes [human epidermal growth factor receptor 2 (HER2), human epidermal growth factor receptor 4 (HER4), epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), Mouse double minute 2 homolog (MDM2), androgen receptor (AR), programmed death (ligand 1 (PD-L1), neurogenic differentiation factor 2 (NEUROD2), phosphatidylinositol 3,4,5-trisphosphate-dependent RAC exchanger 1 protein (PREX1), cyclin-dependent kinase4/6 (CDK4/6), proline-rich acidic protein 1 (PRAP1), kell antigen system (KEL), glutamate receptor subunit epsilon 2 (GRIN2D), Ewing sarcoma RNA-binding protein 1 (EWSR1), MYC proto-oncogene (MYC)] combined or not with chromosomal numerical imbalances (aneuploidy/ polysomy/monosomy) form different genetic signatures affecting the response to monoclonal antibody-based, oncologicaly targeted regimens. Different SGC histotypes demonstrate specific combinations of mutated/amplified genes that modify their clinicohistological features. In the current molecular review, we present the most important amplified oncogenes and their impact on the biological behavior of SGCS.

Calpain-mediated Mechanoptosis in Breast Adenocarcinoma.

Calpains belong to a family of important calcium-dependent cysteine proteases. They are involved in intracellular processes including cytoskeleton disorganization and substrate proteolysis. They also enhance apoptosis and cell to cell adhesion. Calpains demonstrate also a mechanosensory function in neoplastic and malignant cells due to their implication in mechanoptosis. This is a specific type of apoptotic death induced by strong external mechanical stimuli. Anti-cytoskeleton rigidity inhibition strategies based on calpain induction lead to increased apoptosis of tumor transformed cells. Elevated intracellular calcium concentration mediated by specific receptors and channels activates calpains. In the current molecular review, we explored the role of calpains in calcium-dependent signa transduction pathways in breast adenocarcinoma in conjunction with novel agents that activate their important anti-tumor functions.

DNA Mismatch Repair System Imbalances in Breast Adenocarcinoma.

DNA mismatch repair system (MMR) is considered a leading genetic mechanism in stabilizing DNA structure and maintaining its function. DNA MMR is a highly conserved system in bacteria, prokaryotic, and eukaryotic cells, and provides the highest protection to DNA by repairing micro-structural alterations. DNA MMR proteins are involved in the detection and repair of intra-nucleotide base-to-base errors inside the complementary DNA strand recognizing the recently synthesized strand from the parental template. During DNA replication, a spectrum of errors including base insertion, deletion, and miss-incorporation negatively affect the molecule's structure and its functional stability. A broad spectrum of genomic alterations such as promoter hyper methylation, mutation, and loss of heterozygosity (LOH) in MMR genes including predominantly hMLH1, hMSH2, hMSH3, hMSH6, hPMS1, and hPMS2 lead to their loss of base-to-base error repairing procedure. Microsatellite instability (MSI) refers to the DNA MMR gene alterations that are observed in a variety of malignancies of different histological origins. In the current review, we present the role of DNA MMR deficiency in breast adenocarcinoma, a leading cancer-based cause of death in females worldwide.

ALK Protein Expression Patterns in Squamous Cell Carcinoma of the Oral Cavity.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is characterized by a broad spectrum of genomic imbalances, including gross chromosomal (polysomy/aneuploidy) ones as well as specific gene alterations. Aberrant expression of anaplastic lymphoma kinase (ALK) seems to be a useful molecular marker for discriminating patients based on genetic signatures in a variety of solid malignancies, such as lung carcinoma. Our aim was to analyze ALK protein expression patterns in a series of OSCCs. MATERIALS AND METHODS: Fifty (n=50) OSCC tissue sections were analyzed by implementing an ALK-based immunohistochemistry protocol. Digital image analysis was performed for measuring the corresponding protein expression levels. RESULTS: ALK overexpression was observed in 14/50 (28%) OSCC tissue sections, whereas the rest 36/50 (72%) demonstrated low expression levels. ALK expression was negatively associated with grade (p=0.027) and stage (p=0.0028) of the examined cases. CONCLUSION: Abnormal ALK expression in subsets of patients with OSCC seems to be related to an aggressive phenotype (advanced stage/progressive dedifferentiation). ALK protein overexpression may be used as a significant marker for applying targeted therapeutic regimens.

Targeting EGFR in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) represents a specific, aggressive pathological entity included in the Head and Neck Carcinoma (HNC) family of malignancies. NPC is derived from the nasopharyngeal epithelia expressing a high invasive and metastatic potential affecting negatively patients' prognosis due to poor survival rates. Concerning pathogenetic factors implicated in its rise and progression, Epstein-Barr virus (EBV) latent but persistent infection is considered the main one. Novel therapeutic strategies are based on targeting specific molecules such as epidermal growth factor receptor (EGFR) by applying anti-EGFR monoclonal antibodies (mABs) that block their natural ligands interrupting also aberrant signal transduction to nucleus. Anti-EGFR therapies combined or not with radiotherapy seem to be a very promising tool in handling the corresponding patients with NPC that demonstrate specific genetic signatures. In the current article, we focused on presenting EGFR expression in NPC combined with novel anti-EGFR agents.

Reconstructing carcinoma of the lip commissure and buccal mucosa: an oncosurgical alternative approach.

PURPOSE: To describe a new technique of surgical treatment of the lip commissure or buccal mucosa carcinomas, where we use local flaps (skin, buccal mucosa) of the sliding type. METHODS: According to the current technique, the ectomy ranges horizontally and in a cuneiform shape towards the side of the buccal cavity, and in the whole thickness of the layer (skin - mucosa), where the neoplastic focus is enclosed. RESULTS: The difference in our technique consists of the following: To the vertical bi-cuneiform part of the wound a horizontal cuneiform part (with the top showing upwards) is added, with extent and width analogous to those of the cancerous injury (tri-cuneiform ectomy). The width of the gap across its horizontal part is larger on the side of the mucosa (continuous line), compared to the one along the side of the skin (punctuated line), since the mucosa, as a more versatile tissue, can be sutured easily, in contrast to the buccal skin, which is of greater thickness and shows lack of versatility, so that it can be pulled on with difficulty in order to be sutured. The planning of the injury, according to our described technique, facilitates the broad ectomy of the intraoral injuries in the area of the lip commissure and the buccal mucosa, with immediate suture of the flaps (buccal and skin gap), and the occlusion of the wound by primary intention. CONCLUSIONS: Using this specific technique, in the cases of extended injuries infiltrating the skin or the subcutaneous tissue, the harming use of transposition (sliding or free) flaps is avoided.

Micro-RNAs signatures in papillary thyroid carcinoma.

Among biomarkers that should be useful for a molecular discrimination of patients regarding treatment strategies and prognosis in solid malignancies, novel micro-RNAs (miRs) are under investigation. Quite recently, miRs are considered very promising and significant genetic markers for categorizing patients by their molecular characteristics, as well as extending their complicated genetic signatures. miRs are short, non-coding RNAs consisting of 20-25 nucleotides located at intra- or inter-gene regions. Functional miRs mediate a positive regulation of posttranscriptional gene silencing. Their deregulation in cancer cells due to genetic (e.g., mutations, translocations), epigenetic (e.g., DNA hyper-methylation of tumor suppressor genes, extensive genomic DNA hypo-methylation, aberrant histone modification patterns) and transcriptional alterations lead to a loss of miRs-mediated repression of target mRNA. Interestingly, a biphasic role of miRs in cancers of different histogenetic origin has been confirmed. In some of them, their upregulation is correlated with an increased oncogenic activity, whereas in others, the same miR type acts as a suppressor agent. Thyroid carcinoma comprises different histological subtypes, such as papillary thyroid carcinoma (PTC), follicular thyroid carcinoma (FTC), anaplastic thyroid cancer (ATC), and medullary thyroid carcinoma. In the current molecular review, we explored the role of a specific fraction of miRs in PTC subtype by categorizing them according to their up- or down-regulation status.

Impact of Chromosome 9 Numerical Imbalances in Oral Squamous Cell Carcinoma: A Pilot Grid-Based Centromere Analysis.

Oral squamous cell carcinoma (OSCC) is considered an aggressive malignancy, mainly due to its increased propensity to provide local and distant lymph node metastases. Gross chromosome instability (CI; polysomy/aneuploidy/monosomy), combined or not with specific gene alterations, is implicated in the development and progression of solid malignancies, including OSCC. In order to further study the relationship between these genetic alterations and the aggressive biological behavior of OSCCs, we investigated the frequency and impact of chromosome 9 numerical imbalances in these tumors. Fifty (n = 50) formalin-fixed, paraffin-embedded primary OSCC tissue sections were used. Chromogenic in situ hybridization (CISH) was implemented for detecting chromosome 9 (CEN-centromere enumeration) numerical alterations. Concerning the screening process in CISH slides, a novel, real-time reference and calibration grid platform was implemented. Chromosome 9 polysomy was observed in 8/50 (16%) tissue sections, whereas the rest of them demonstrated a normal, diploid pattern (42/50; 84%). Chromosome 9 polysomy was associated with the grade of differentiation of the examined tumors (p = 0.036). Chromosome 9 numerical imbalances (polysomy) were observed in sub-groups of OSCCs correlating with a progressive dedifferentiation of the malignant tissues. Concerning the implementation of the proposed grid-based platform as described above on CISH slides, it provides a novel, fast, and accurate screening mapping mechanism for detecting chromosome numerical imbalances.

mdm2 oncogene in laryngeal squamous cell carcinoma.

Laryngeal squamous cell carcinoma (LSCC) demonstrates increasing rates worldwide due to viral-related (High Risk Human Papilloma Virus-HR HPV) persistent infection, cigarette and alcohol consumptions. Gross chromosomal alterations and specific gene aberrations-such as amplifications, deletions, point mutations-combined or not with epigenetic changes are responsible for the progressive transformation of normal squamous epithelia to their malignant phenotype. Among oncogenes that are implicated in the development and progression of LSCC, mouse double minute 2 homolog / murine double minute 2 (mdm2) seems to be an interesting marker for the biological behavior of the malignancy. Mdm2 is a proto-oncogene (gene locus: 12q14.3), encodes for a nuclear-localized E3 ubiquitin ligase, and acts as a major negative regulator in p53-mdm2 auto-regulatory pathway. Mdm2 directly binds to p53 and represses its transcriptional activity and promotes p53 proteasomal degradation. Aberrant mdm2 overexpression is a frequent observation in breast carcinomas, whereas there are limited data regarding LSCC. In the current molecular review we explored the role and specific aspects of mdm2 gene in LSCC.

c-Jun/c-Fos complex in laryngeal squamous cell carcinoma.

During laryngeal carcinogenesis, a variety of genomic imbalances are involved in hyperplastic and dysplastic laryngeal epithelia as early or progressive genetic events, respectively. Oncogenes' overactivation is a crucial genetic event in malignant and pre-malignant neoplastic epithelia. Especially, deregulation of crucial pathways including transcription factors - such as c-Fos and c-Jun - leads to an aberrant expression of other crucial genes responsible for cell homeostasis. Upregulation of c-Fos and c-Jun proto-oncogenes -due to increased copy numbers (amplification) or intra-genic point mutations- seems to be correlated with aggressive biological behaviour in laryngeal squamous cell carcinomas (LSCCs). In the current special molecular article we explored the role of c-Fos/c-Jun complex deregulation in LSCC.

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.

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.

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.

p53 mutations in oral cavity carcinoma.

Head and neck squamous cell carcinoma (HNSCC) includes a variety of SCCs derived from the anatomic regions of the oral and nasal cavity and also of the pharynx and larynx. Oral cavity SCC (OCSCC) demonstrates an increasing rate due to viral -related (High Risk Human Papilloma Virus-HR HPV) persistent infection, cigarette smoking and alcohol consumption. Gross chromosomal alterations (polysomy, aneuploidy) and specific gene aberrations such as amplifications, deletions, point mutations combined or not with epigenetic ones (promoter methylations and miRNA deregulations) are responsible for the progressive transformation of normal squamous epithelia to the corresponding malignant. In the majority of OCSCC cases, critical genes, such as p53 are found to be inactivated, leading to an overactivated cell cycle correlated to carcinogenetic process. P53 (gene location: 17p13.1) is a suppressor gene acting as a key regulator of the cell's genomic stability, function and homeostasis. P53 aberrant overexpression is frequently observed in OCSCC tissues as a result of point mutation or deletion. In the current special article we explored the role of the p53 gene deregulation - especially focused on its mutation status - in OCSCCs.