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.

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.

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.

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.

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.

Assessing the clinical utility of Wnt pathway markers in colorectal cancer

PURPOSE

β-catenin and AXIN2 play an important role in the Wnt signaling pathway. The aim of this study was to investigate β-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

β-catenin overexpression in the nucleus was associated with advanced N stage CRCs (p=0.04). Multivariate Cox regression analysis showed that β-catenin overexpression is an independent prognostic factor for overall survival (OS). A positive correlation between β-catenin location and AXIN2 mRNA was observed.

CONCLUSIONS

Nuclear β-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.

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.

Strangulated intestinal hernia through a drain site

INTRODUCTION

Intra-abdominal drains have been widely used in order to prevent intra-abdominal fluid accumulation and detection of anastomotic leakage.

PRESENTATION OF CASE

We herein report a case of small bowel herniation followed by strangulation in an 82 year old woman who had undergone sigmoidectomy for colorectal cancer.

DISCUSSION

Although several complications related to drain usage such as drainsite infection, hemorrhage and intestinal perforation may occur, intestinal incarceration through drain site is rarely reported.

CONCLUSION

Drains must be used with caution and only if indicated. Careful insertion, regular post-operative or post-removal inspection is strongly recommended.

Multicystic nephroma in an elderly man. Case report

Multicystic nephroma is a relatively rare tumor of the kidney presenting unclear histological origin. Abdominal mass is a common onset sign in children while abdominal flank pain or abdominal discomfort, hematuria and recurrent urinary tract infections usually affect adults. Preoperative diagnosis is impossible especially in the adult variant of the tumor where clear cells carcinoma with cystic degeneration must always be suspected. We herein report a case of a 77 year old man complaining of flank abdominal pain and recurrent episodes of urinary tract infection due to a right-sided multicystic nephroma successfully treated with nephrectomy.

Primary retroperitoneal mucinous cystadenoma of borderline malignancy in a male patient. Case report and review of the literature

BACKGROUND

Primary retroperitoneal mucinous cystadenoma of borderline malignancy represents a rare tumor, with unclear histogenesis, concerning almost exclusively women. Only two cases concerning male patients have been reported.

CASE REPORT

We herein report a case of a 37 year old man undergone laparotomy for a sizable retroperitoneal tumor resulting after the histological examination to a primary retroperitoneal mucinous cystadenoma of borderline malignancy.

CONCLUSION

This is the third case of primary retroperitoneal mucinous cystadenoma of borderline malignancy in a male patient reported in the literature. The preoperative diagnosis is impossible. Laparotomy constitutes the only diagnostic and curative approach.

Multiarticular chronic tophaceous gout with severe and multiple ulcerations: a case report

Introduction

Gout is a common inflammatory arthritis caused by articular precipitation of monosodium urate crystals. It usually affects the first metatarsophalangeal joint of the foot and less commonly other joints, such as wrists, elbows, knees and ankles.

Case presentation

We report the case of a 75-year-old Caucasian man with tophaceous multiarticular gout, soft-tissue involvement and ulcerated tophi on the first metatarsophalangeal joint of the left foot, on the first interphalangeal joint of the right foot and on the left thumb.

Conclusion

Ulcers due to tophaceous gout are currently uncommon considering the positive effect of pharmaceutical treatment in controlling hyperuricemia. Surgical treatment is seldom required for gout and is usually reserved for cases of recurrent attacks with deformities, severe pain, infection and joint destruction.

Stercoral perforation of the sigmoid colon. A case report and brief review of the literature

Stercoral perforation of the colon due to fecaloma is a rare disease and less than 100 cases have been described in the literature. The disease mainly involves the rectosigmoid colon. The condition is correlated with longstanding decubitus, chronic constipation, abuse of laxatives and/or constipating agents (anticholinergics, neuroleptics, etc). We report a case of 82-year old woman who presented a covered colonic perforation due to fecaloma, related with a history of longstanding decubitus because of senile dementia, chronic constipation and use of anticholinergic drugs.

Sclerosing Mesenteritis: Diverse clinical presentations and dissimilar treatment options. A case series and review of the literature

Sclerosing mesenteritis (SM) is a rare pathological condition affecting the mesentery. It is a benign, non-specific inflammation of the adipose tissue of the mesentery of the small intestine and colon. It is characterized by a variable amount of chronic fibrosis. Its etiology is unknown, the pathogenesis is obscure, while the pathological characteristics of the disease are unspecific. The initial clinical presentation varies from typically asymptomatic to that of an acute abdomen. The diagnosis is suggested by computed tomography but is usually confirmed by surgical biopsies. Treatment is largely empirical; it is decided upon on the basis of the clinical condition of the patient, and usually a few specific drugs are used. Surgical resection is sometimes attempted for definitive therapy, although the surgical approach is often limited. We will present five cases of SM as well as a review of the available literature in order to state and compare a variety of clinical presentations, diverse possible etiologies and dissimilar treatment options.

Traumatic mesenteric cyst after blunt abdominal trauma

Mesenteric cysts are rare abdominal tumors of unclear histologic origin, usually asymptomatic. Post-traumatic mesenteric cyst usually results as a consequence of a mesenteric lymphangitic rupture or a hematoma followed by absorption and cystic degeneration. The preoperative histological and radiological diagnosis is difficult. We present the case of a 45-year-old male patient with sizable, palpable abdominal tumor, the gradual swelling of which the patient himself combined with the blunt abdominal trauma he acquired from an opponent's knee in a football game 5 months ago.

Multifocal pyomyositis and meningitis after bone marrow biopsy in a diabetic patient

Primary or tropical pyomyositis is a subacute infection of the skeletal muscle complicated by abscess formation. The disease is rare in the temperate climates and often misdiagnosed because of the vague clinical presentation. We herein report a case of a 38-year-old diabetic patient with a history of recent bone marrow biopsy presented multifocal primary pyomyositis complicated by meningitis.

Multiple giant diverticula of the jejunum causing intestinal obstruction: report of a case and review of the literature

Multiple diverticulosis of jejunum represents an uncommon pathology of the small bowel. The disease is usually asymptomatic and must be taken into consideration in cases of unexplained malabsorption, anemia, chronic abdominal pain or discomfort. Related complications such as diverticulitis, perforation, bleeding or intestinal obstruction appear in 10-30% of the patients increasing morbidity and mortality rates. We herein report a case of a 55 year-old man presented at the emergency department with acute abdominal pain, vomiting and fever. Preoperative radiological examination followed by laparotomy revealed multiple giant jejunal diverticula causing intestinal obstruction. We also review the literature for this uncommon disease.