Comparative Expression Analysis of TP53 Tumor Suppressor and MDM2 Oncogene in Colorectal Adenocarcinoma.

Background/Aim: The tumor protein 53 (TP53) tumor suppressor protein (17p13.1) acts as a significant regulator for the cell cycle normal function. The gene is frequently mutated in colorectal adenocarcinoma (CRC) patients and is associated to poor prognosis and low response rates to chemo-targeted therapy. Our purpose was to correlate TP53 expression with Mouse Double Minute 2 Homolog (MDM2), a proto-oncogene (12q14.3) and a major negative regulator in the TP53-MDM2 auto-regulatory pathway. Materials and Methods: A total of forty (n=40) colorectal adenocarcinoma (CRC) cases were included in this study. An immunohistochemistry-based assay was implemented by using anti-TP53 and anti-MDM2 antibodies in the corresponding tissue sections. Additionally, a digital image analysis assay was implemented for objectively measuring TP53/MDM2 immunostaining intensity levels. Results: TP53 protein overexpression was detected in 27/40 (67.5%), whereas MDM2 overexpression in 28/40 (70%) cases. Interestingly, in 21/40 (52.5%) cases, a combined TP53/MDM2 co-expression was detected, whereas in 6/40 (15%), a combined loss of expression was identified (overall co-expression: p=0.119). p53 overexpression was significantly correlated to grade of the examined cases (p=0.001), whereas MDM2 to stage and max diameter of the malignancies (p=0.001 and 0.024, respectively). Conclusion: TP53/MDM2 over expression is a frequent and significant genetic event in CRCs associated with an aggressive biological behavior, as a result of increased dedifferentiation grade and advanced stage/elevated tumor volume, respectively. MDM2 oncogene overactivation combined with mutated and overexpressed TP53 is observed in sub-groups of patients leading to specific gene/protein signatures - targets for personalized chemotherapeutic approaches.

Mutational Signatures in Salivary Gland Carcinomas.

Salivary gland carcinomas belong to the head and neck carcinoma super category of malignancies. They are characterized by histopathological diversity and comprise a variety of entities and subtypes. Mucoepidermoid, adenoid cystic and salivary duct carcinomas represent the most prominent malignancies. Concerning their corresponding genetic background, a broad spectrum of gene and chromosomal imbalances has been detected. Point mutations and deletions, amplifications and translocations, combined or not with chromosomal aneuploidy/polysomy/monosomy, create a landscape of specific genetic signatures that affect the biological behavior of these tumors and modify response rates to potential targeted therapeutic strategies. In the current molecular review, we focused on the categorization and description of the most important mutational signatures in salivary gland carcinomas.

P53/MDM2 Complex-Based Targeted Strategies in Colon Adenocarcinoma.

In the current molecular review, we describe the mechanisms of TP53/MDM2 deregulation and their impact on the colon adenocarcinoma molecular substrate and phenotype. Among the genes that are critically altered in carcinogenesis, the TP53 tumor suppressor gene is of major importance. The TP53 gene (gene locus: 17p13.1) regulates the cell cycle by controlling the G1/S and G2/M checkpoints securing the normal sequence of cell cycle phases. Furthermore, it is involved in apoptosis programmed cell death. The gene is mutated or epigenetically altered in all epithelial malignancies, including colon adenocarcinoma. Additionally, Mouse Double Minute 2 Homolog (MDM2), a proto-oncogene (12q14.3), acts as a major negative regulator for p53 expression in the p53-MDM2 auto-regulatory pathway. MDM2 binds directly to p53 and represses its transcriptional activity, promoting p53 degradation. CONCLUSION: In colon adenocarcinoma, MDM2 oncogene overexpression directly influences p53 oncoprotein expression levels.

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.

Epigenetic Mechanisms in Breast Adenocarcinoma: Novel DNA Methylation Patterns.

Breast adenocarcinoma is a leading cause of death in females worldwide. A broad spectrum of genetic and epigenetic alterations has been already identified and reported in millions of examined cancerous substrates, evidence of a high-level genomic heterogeneity that characterizes these malignancies. Concerning epigenetic changes and imbalances that critically affect progression and prognosis in the corresponding patients, DNA methylation, histone modifications (acetylation), micro-RNAs (miRs) alterations and chromatin re-organization represent the main mechanisms. Referring to DNA methylation, promoter hyper-hypo methylation in critical tumour suppressor and oncogenes is implicated in normal epithelia transformation to their neoplastic and finally malignant cyto-phenotypes. The current review is focused on the different methylation patterns and mechanisms detected in breast adenocarcinoma and their impact on the corresponding groups of patient response to specific chemotherapeutic regimens and life span prognosis.

P53 Suppressor Gene Tissue Microarray-based Protein Expression Analysis in Meningiomas.

BACKGROUND/AIM: Meningiomas represent the main intracranial primary central nervous system (CNS) tumour in adults worldwide. Oncogenes' over-activation combined with suppressor genes' silencing affect negatively the biological behavior of these neoplasms. This study aimed to explore the impact of p53 suppressor gene expression in meningiomas' clinic-pathological features based on a combination of sophisticated techniques. MATERIALS AND METHODS: Fifty (n=50) meningiomas were included in the study, comprising a broad spectrum of histopathological subtypes. An immunohistochemistry assay was applied on tissue microarray cores followed by digital image analysis. RESULTS: p53 protein over-expression (high staining intensity levels) was observed in 27/50 (54%) cases, whereas the rest (23/50-/46%) demonstrated moderate to low levels of the protein. p53 over-expression was statistically significantly correlated to the mitotic index of the examined cases (p-value=0.001). Interestingly, the atypical/anaplastic group of histotypes demonstrated the strongest p53 expression rates compared to the others (p-value=0.001). CONCLUSION: p53 overexpression is observed in a broad spectrum of meningiomas. High expression levels lead to an aggressive biological behavior of the malignancy (combined with increased mitotic rates), especially in atypical and anaplastic sub-types that also have a high recurrence rate.

Caspase 8 Expression Patterns in Meningiomas: A Tissue Microarray Digital Image Analysis.

BACKGROUND: Caspases (cysteine-aspartic proteases) represent a family of enzymes that critically influence cell homeostasis by being involved in inflammation and apoptosis mechanisms. Meningiomas demonstrate the most common intracranial primary central nervous system tumors in adults worldwide. AIM: Our purpose was to explore the role of caspase 8 expression in meningiomas' pathological features. MATERIALS AND METHODS: A total of 50 meningioma cases were included in the study, comprising a broad spectrum of histopathological sub-types. An immunohistochemistry assay was applied on tissue microarray cores followed by digital image analysis. RESULTS: Overexpression of caspase 8 protein was observed in 21/50 (42%) cases, whereas the rest of them (29/50, 58%) demonstrated moderate to low levels of the molecule. Caspase 8 overall expression was statistically significantly correlated to grade of the examined tumors and to mitotic index (p=0.001,p=0.002, respectively). CONCLUSIONS: Caspase 8 aberrant expression is observed in meningiomas associated with their differentiation grade and mitotic activity. Targeted therapeutic strategies focused on enhancing caspase 8 expression and also inducing the overall apoptotic activity should be a very promising approach in rationally handling sub-groups of meningioma patients.

Secretory Phospholipase A2 Digital Expression Analysis in Colon Adenocarcinoma.

BACKGROUND/AIM: Phospholipases A2 represent a family of enzymes that regulate the metabolism of phospholipids by hydrolyzing them into fatty acids. Secretory phospholipase A2 (SPLA2) catalyzes the calcium-dependent 2-acyl groups hydrolysis to produce 3-sn-phosphoglycerides. This study aimed to investigate SPLA2 expression in colon adenocarcinoma (CA). MATERIALS AND METHODS: Thirty (n=30) formalin-fixed, paraffin-embedded primary CA tissue sections were used and analyzed. Immunohistochemistry was performed using an anti-SPLA2 antibody. Digital image analysis was also implemented for evaluating objectively the corresponding protein expression levels. RESULTS: Increased SPLA2 protein expression (high & moderate immunostaining levels) was observed in 23/30 (76.6%) cases, whereas 7/30 (23.4%) CA tissues demonstrated low protein levels. High expression levels were detected in 9/30 (30%) cases. SPLA2 overall expression was strongly associated with tumor diameter (p=0.004), whereas other statistically significant associations were not observed (stage: p=0.971, inflammatory infiltration: p=0.795; carcinoma location: p=0.340; differentiation grade: p=0.748; sex: p=0.369; ulceration: p=0.433). CONCLUSION: SPLA2 over-expression is observed in significant subsets of CAs correlating with advanced tumor growth progression (increased diameter). SPLA2 seems to influence endogenous cell responses by its crucial enzymatic activity and can potentially be a biomarker for monitoring CA patients.

Impact of peroxiredoxin-6 expression on colon adenocarcinoma.

PURPOSE: Peroxiredoxins (Prdxs) represent a family of proteins that act as antioxidant enzymes and are involved in a variety of metabolic functions including mainly the intracellular hydrogen peroxide (H2O2) levels reduction. Especially, Prdx-6 protein encoded by the PRDX6 gene (1q25.1) regulates also phospholipid modifications and induces response to oxidative stress and injuries. Our aim was to investigate the expression of Prdx-6 in colon adenocarcinoma (CA). METHODS: A series of 30 formalin-fixed, paraffin-embedded primary CAs tissue sections were used and analyzed. Immunohistochemistry was performed using an anti-Prdx-6 antibody. Digital image analysis was also implemented for evaluating objectively the protein expression levels on the corresponding stained cells. RESULTS: Prdx-6 protein overexpression (increased immunostaining levels) was observed in 12/30 (40%) cases, whereas 18/30 (60%) CA tissues demonstrated low to moderate protein levels, respectively. Prdx-6 overall expression was strongly associated with the stage of the examined tumors (p=0.011), whereas other statistical significances were not assessed (inflammatory infiltration: p=0.364; carcinoma location: p=0.93; differentiation grade: p=0.517; tumor diameter: p=0.983; ulceration: p=0.622). CONCLUSIONS: Prdx-6 overexpression is observed in a significant subset of CAs correlating with aggressive biological behavior (advanced stage). Prdx-6 is a crucial enzyme for oxidative stress/injury endogenous cell response and should be an interesting agent as a biomarker and potential therapeutic target.

Silibinin Effect on Fas/FasL, HMGB1, and CD45 Expressions in a Rat Model Subjected to Liver Ischemia-Reperfusion Injury.

PURPOSE: We investigated the hepatoprotective effect of Silibinin (SLB) to ischemia-reperfusion (I/R) rat model, by evaluating the histological expression of the tissue markers Fas/FasL, HMGB-1 and CD45, and SLB pharmacokinetics. METHODS: Seventy-three Wistar-type male rats were randomized in 11 groups: Sham control group (open-close laparotomy); four I/R control groups (laparotomy, 45 min vascular occlusion, reperfusion, euthanasia after 60, 120, 180, and 240 min); four SLB (Si) groups (laparotomy, 45 min vascular occlusion, IV administration of SLB, reperfusion, euthanasia after 60, 120, 180, and 240 min); two SLB pharmacokinetics (PK) groups (IV administration of SLB, euthanasia after 45 and 240 min). RESULTS: Fas/FasL increased with reperfusion time in I/R control groups and decreased in the Si groups, reaching, respectively, the highest and lowest values at 240 min of reperfusion (p <.0001). HMGB1 and CD45 increased with time in the I/R control groups up to 240 min and decreased in the Si groups, approaching zero expression after 180 and 60 min, respectively. Pharmacokinetic data showed higher liver accumulation and slower plasma elimination of SLB in ischemic animals. CONCLUSIONS: The hepatoprotective effect of SLB was demonstrated through the reduction of the expression of Fas/FasL, HMGB-1 and CD45 in liver tissue under I/R conditions, and in the pharmacokinetic study. The results document the efficacy of silibinin in the protection of the liver, and are particularly encouraging for its use in hepatic surgery.

Assessing the clinical utility of Wnt pathway markers in colorectal cancer.

PURPOSE: ß-catenin and AXIN2 play an important role in the Wnt signaling pathway. The aim of this study was to investigate ß-catenin and AXIN2 expression in colorectal cancer (CRC) and relate these findings with patients' clinicopathological features and prognosis. METHODS: 57 consecutive patients with surgically treated CRC were included in this study. Quantitative PCR and immunohistochemistry (IHC) analyses were performed to characterize the expression of the aforementioned markers in CRC tissues. RESULTS: ß-catenin overexpression in the nucleus was associated with advanced N stage CRCs (p=0.04). Multivariate Cox regression analysis showed that ß-catenin overexpression is an independent prognostic factor for overall survival (OS). A positive correlation between ß-catenin location and AXIN2 mRNA was observed. CONCLUSIONS: Nuclear ß-catenin is a valuable prognostic factor. AXIN2 is a component of the "Destruction Complex" and also a Wnt target gene. However, the clinical importance of AXIN2 expression in CRC remains unclear.

Human subcutaneous dirofilariasis caused by Dirofilaria immitis in a Greek adult.

Human dirofilariasis is a zoonotic infection caused by worms of the genus Dirofilaria. Most reported cases involve Dirofilaria repens, and D. immitis infection has been rarely reported. Canines act as a reservoir for the infection, while human infections are sporadic. Human dirofilariasis has been widely reported in South Europe; however, the worldwide distribution constantly changes. We herein report an extremely rare case of subcutaneous trunk dirofilariasis in a 45-year-old immunosuppressed woman, caused by D. immitis. The parasitic infection was detected using ultrasonography. The infection was confirmed by a polymerase chain reaction-based method and was attributed to D. immitis.

Sigmoid carcinoma localized in the sac of a right inguinoscrotal hernia.

The inguinoscrotal hernia with colonic malignancy in the sac presents rare but severe consequence. The most common side of this type of hernia is the left one while the most common part of the large bowel is the sigmoid colon. The clinical picture can be easily confused with simple inguinoscrotal hernia unless the clinician is alert to the presence of certain sinister symptoms and signs. We report an extremely rare case of a 91-year-old man presented with anemia who had a right inguinoscrotal hernia containing a sigmoid colon carcinoma.

Asymptomatic extraperitoneal inguinoscrotal hernia involving ureter: A case presentation and review of the literature.

An inguinoscrotal hernia is a common disorder that usually contains intraperitoneal organs (small intestine, colon, appendix, ovaries). Extraperitoneal ureteral herniation into an inguinoscrotal hernia is a rare condition and often associated with congenital abnormalities or postoperative anatomic changes. A high index of suspicion is needed in order to avoid intraoperative ureteric injuries. We herein report the case of a ureteric herniation into an inguinoscrotal hernia incidentally found during a scheduled hernia repair.

Persistent Coughing as the First Symptom of Primary Mucinous Appendiceal Adenocarcinoma.

Primary appendiceal adenocarcinomas are extremely rare entities. Preoperative diagnosis is very difficult and is mainly based on computed tomography (CT) scan findings. Furthermore, in many cases, difficulties in establishing an accurate intraoperative diagnosis have resulted in a two-stage surgical intervention. We herein report a case of a primary appendiceal mucinous adenocarcinoma in a 67-year-old Caucasian man who presented with atypical symptoms of persistent coughing and weight loss. The chest CT showed lesions with features favorable of malignancy. Further investigation with abdominal CT and colonoscopy revealed a large tumor of the cecum expanding to the ascending colon. Typical right hemicolectomy was performed and the histopathological examination confirmed mucinous adenocarcinoma of the appendix. As some cases are accidentally discovered, the presented case describes an extremely rare first presentation of this tumor and emphasizes that the preoperative diagnosis of appendiceal cancer is challenging due to the lack of specific symptoms and signs.

Rectus abdominis muscle malignant fibrous histiocytoma causing a large abdominal wall defect: reconstruction with biological mesh.

Malignant fibrous histiocytoma (MFH) is a common soft tissue sarcoma usually involving limbs and retroperitoneum. MFH of the rectus abdominis muscle is extremely rare. Surgery in similar cases leads to large abdominal wall defects needing reconstruction. Biological and synthetic laminar absorbable prostheses are available for the repair of hernia defects in the abdominal wall. They share the important feature of being gradually degraded in the host, resulting the formation of a neotissue. We herein report the case of an 84-year-old man with MFH of the rectus abdominis muscle which was resected and the large abdominal wall defect was successfully repaired with a biological mesh.