Molecular Targeting of H/MDM-2 Oncoprotein in Human Colon Cancer Cells and Stem-like Colonic Epithelial-derived Progenitor Cells.

BACKGROUND/AIM: We have tested whether the anticancer peptide, PNC-27, that kills cancer cells but not normal cells by binding to cancer cell membrane HDM-2 forming pores, kills CD44+ colon cancer stem cells. MATERIALS AND METHODS: Flow cytometry determined the CD44 and HDM-2 expression on six-colon cancer cell lines and one normal cell line (CCD-18Co). MTT, LDH release, annexin V binding and caspase 3 assays were used to assess PNC-27-induced cell death. Bioluminescence imaging measured PNC-27 effects on in vivo tumor growth. RESULTS: High percentages of cells in all six tumor lines expressed CD44. PNC-27 co-localized with membrane HDM-2 only in the cancer cells and caused total cell death (tumor cell necrosis, high LDH release, negative annexin V and caspase 3). In vivo, PNC-27 caused necrosis of tumor nodules but not of normal tissue. CONCLUSION: PNC-27 selectively kills colon cancer stem cells by binding of this peptide to membrane H/MDM-2.

Anti-Cancer Tumor Cell Necrosis of Epithelial Ovarian Cancer Cell Lines Depends on High Expression of HDM-2 Protein in Their Membranes.

OBJECTIVE: Patients with epithelial ovarian cancers experience the highest fatality rates among all gynecological malignancies which require development of novel treatment strategies. Tumor cell necrosis was previously reported in a number of cancer cell lines following treatment with a p53-derived anti-cancer peptide called PNC-27. This peptide induces necrosis by transmembrane pore formation with HDM-2 protein that is expressed in the cancer cell membrane. We aimed to extend these studies further by investigating expression of membrane HDM-2 protein in ovarian cancer as it relates to susceptibility to PNC-27. PROCEDURES: Herein, we measured HDM-2 membrane expression in two ovarian cancer cell lines (SKOV-3 and OVCAR-3) and a non-transformed control cell line (HUVEC) by flow cytometric and western blot analysis. Immunofluorescence was used to visualize colocalization of PNC-27 with membrane HDM-2. Treatment effects with PNC-27 and control peptide were assessed using a MTT cell proliferation assay while direct cytotoxicity was measured by lactate dehydrogenase (LDH) release and induction of apoptotic markers; annexin V and caspase-3. RESULTS: HDM-2 protein was highly expressed and frequently detected in the membranes of SKOV-3 and OVCAR-3 cells; a prominent 47.6 kDa HDM-2 plasma membrane isoform was present in both cell lines whereas 25, 29, and 30 kDa isoforms were preferentially expressed in OVCAR-3. Notably, PNC-27 colocalized with HDM-2 in the membranes of both cancer cell lines that resulted in rapid cellular necrosis. In contrast, no PNC-27 colocalization and cytotoxicity was observed with non-transformed HUVEC demonstrating minimal expression of membrane HDM-2. CONCLUSIONS: Our results suggest that HDM-2 is highly expressed in the membranes of these ovarian cancer cell lines and colocalizes with PNC-27. We therefore conclude that the association of PNC-27 with preferentially expressed membrane HDM-2 isoforms results in the proposed model for the formation of transmembrane pores and epithelial ovarian cancer tumor cell necrosis, as previously described in a number of solid tissue and hematologic malignancies.

Patient-specific predictors of failure to rescue after pancreaticoduodenectomy.

BACKGROUND: Failure to rescue (FTR) is a recently described outcome metric for quality of care. However, predictors of FTR have not been adequately investigated, particularly after pancreaticoduodenectomy. We aim to identify predictors of FTR after pancreaticoduodenectomy. METHODS: We reviewed all patients who developed serious morbidity after pancreaticoduodenectomy from 2005 to 2012 in the ACS-NSQIP database. Logistic regression was used to identify preoperative and postoperative risks for 30-day mortality within a development cohort (randomly selected 80%). A score was created using weighted beta coefficients. Predictive accuracy was assessed on the validation cohort (remaining 20%) using a receiver operator characteristic curve and calculating the area under the curve (AUC). RESULTS: The FTR rate was 7.2% after pancreaticoduodenectomy (n = 5,027). We identified 5 independent risk factors: age ≥65 and albumin ≤3.5 g/dL, preoperatively; and development of shock, renal failure, and reintubation, postoperatively. The generated score had an AUC = 0.83 (95% CI, 0.77-0.89) in the validation cohort. Using the score: 1*Albumin ≤3.5 g/dL + 2*Age ≥ 65 + 2*Shock + 5*Renal failure + 5*Reintubation, FTR rates increased with increasing score (p < 0.001). CONCLUSION: FTR rates have previously been shown to be associated with hospital factors. We show that FTR is also associated with preoperative and postoperative patient-specific factors.

Reconstruction options following pancreaticoduodenectomy after Roux-en-Y gastric bypass: a systematic review.

BACKGROUND: Obesity is a risk factor for pancreatic cancer which may be treated with Roux-en-Y gastric bypass and represents an increasing morbidity. Post-RYGB anatomy poses considerable challenges for reconstruction after pancreaticoduodenectomy (PD), a growing problem encountered by surgeons. We characterize specific strategies used for post-PD reconstruction in the RYGB patient. METHODS: PubMed search was performed using MeSH terms "Gastric Bypass" and "Pancreaticoduodenectomy" between 2000 and 2018. Articles reporting cases of pancreaticoduodenectomy in post-RYGB patients were included and systematically reviewed for this study. RESULTS: Three case reports and five case series (25 patients) addressed PD after RYGB; we report one additional case. The typical post-gastric bypass PD patient is a woman in the sixth decade of life, presenting most commonly with pain (69.2%) and/or jaundice (53.8%), median 5 years after RYGB. Five post-PD reconstructive options are reported. Among these, the gastric remnant was resected in 18 cases (69.2%), with reconstruction of biliopancreatic drainage most commonly achieved using the distal jejunal segment of the pre-existing biliopancreatic limb (73.1%). Similarly, in the eight cases where the gastric remnant was spared (30.8%), drainage was most commonly performed using the distal jejunal segment of the biliopancreatic limb (50%). Among the 17 cases reporting follow-up data, median was 27 months. CONCLUSION: Reconstruction options after PD in the post-RYGB patient focus on resection or preservation gastric remnant, as well as creation of new biliopancreatic limb. Insufficient data exists to make recommendations regarding the optimal reconstruction option, yet surgeons must prepare for the possible clinical challenge. PD reconstruction post-RYGB requires evaluation through prospective studies.

Multidisciplinary strategies in bloodless medicine and surgery for patients undergoing pancreatectomy.

BACKGROUND: Bloodless pancreatic surgery (BPS) is rarely performed and/or reported. We aim to characterize perioperative and anesthetic strategies in BPS. MATERIALS AND METHODS: A literature search was performed on MEDLINE looking for case reports/case series using search terms ("Jehovah's Witness" [All Fields]) AND ("Pancreatic Surgery" [All Fields] OR "Pancreaticoduodenectomy" [All Fields] OR "Distal Pancreatectomy" [All Fields]). Data regarding categorical variables are reported as proportions and quantitative continuous variables as medians with ranges or means with standard deviation. Forty-one patients requiring BPS are reported in the literature with three additional cases from our institution (n = 44). The data analyzed included clinicopathologic factors, BPS strategies, patient complications, and in-hospital mortality. RESULTS: The most common procedure and diagnosis were pancreaticoduodenectomy (n = 34, 77.3%) and pancreatic ductal adenocarcinoma (n = 12, 27.3%), respectively. Transfusion reduction strategies in BPS fell into three categories: preoperative, intraoperative, and postoperative. Preoperative strategies included iron supplementation (n = 24, 54.5%) and erythropoietin administration (n = 14, 41.2%). Intraoperative strategies included acute normovolemic hemodilution (n = 30, 68%) and cell saver (n = 4, 9.1%). Postoperative strategies included erythropoietin (n = 16, 48.5%) and iron supplementation (n = 16, 48.5%). Complications occurred in 21 (60%) patients. There was no in-hospital mortality among the 44 patients in this cohort. CONCLUSIONS: A broad spectrum of bloodless medicine and surgery practices were used based on patient selection, multidisciplinary practice, and preference. With careful perioperative and anesthetic management, BPS can be performed with good outcomes.

Emerging Role of MDM2 as Target for Anti-Cancer Therapy: A Review.

The mouse/murine protein, MDM2, and its human homolog, HDM2, are important negative regulators of the p53 tumor suppressor protein. In normal, untransformed cells, MDM2 levels are tightly regulated to control expression of p53 and apoptosis. Conversely, MDM2 expression appears inherently higher in multiple types of cancer cells, thereby supporting its role as a suppressor of p53 pro-apoptotic activity. MDM2 amplification ranges between two- and ten-fold as reported in brain, breast, lung, and soft tissue tumors. MDM2 regulates p53 by two mechanisms: acting as a physical blockade of the transcriptional activation domain and E3 ubiquitin ligase. In addition to its relationship with p53, MDM2 behaves as an independent oncogene. These inherent characteristics make MDM2 a promising target for developing anti-cancer therapies. Investigators are now exploring both p53- dependent and independent cancer cell death pathways by targeting MDM2. Disrupting MDM2-p53 interaction with resultant increase in p53 induces cancer cell cycle arrest and apoptosis. Targeting over-expressed MDM2 on cancer cell membranes disrupts membrane integrity by pore formation, causing membrane destabilization and rapid cancer cell-specific necrosis. In this review, evidence supporting the evolving role of MDM2 as an anti-cancer target and a molecular-based tumor biomarker will be discussed.

WHipple-ABACUS, a simple, validated risk score for 30-day mortality after pancreaticoduodenectomy developed using the ACS-NSQIP database.

BACKGROUND: Pancreaticoduodenectomy needs simple, validated risk models to better identify 30-day mortality. The goal of this study is to develop a simple risk score to predict 30-day mortality after pancreaticoduodenectomy. METHODS: We reviewed cases of pancreaticoduodenectomy from 2005-2012 in the American College of Surgeons-National Surgical Quality Improvement Program databases. Logistic regression was used to identify preoperative risk factors for morbidity and mortality from a development cohort. Scores were created using weighted beta coefficients, and predictive accuracy was assessed on the validation cohort using receiver operator characteristic curves and measuring area under the curve. RESULTS: The 30-day mortality rate was 2.7% for patients who underwent pancreaticoduodenectomy (n = 14,993). We identified 8 independent risk factors. The score created from weighted beta coefficients had an area under the curve of 0.71 (95% confidence interval, 0.66-0.77) on the validation cohort. Using the score WHipple-ABACUS (hypertension With medication + History of cardiac surgery + Age >62 + 2 × Bleeding disorder + Albumin <3.5 g/dL + 2 × disseminated Cancer + 2 × Use of steroids + 2 × Systemic inflammatory response syndrome), mortality rates increase with increasing score (P < .001). CONCLUSION: While other risk scores exist for 30-day mortality after pancreaticoduodenectomy, we present a simple, validated score developed using exclusively preoperative predictors surgeons could use to identify patients at risk for this procedure.

Palliative Surgery for Advanced Cancer: Identifying Evidence-Based Criteria for Patient Selection: Case Report and Review of Literature.

BACKGROUND: Criteria for selecting patients with advanced cancer for palliative surgery (PS) remains poorly defined. Decision making for PS requires realistic treatment goals with well-defined criteria. Here we discuss a 71-year-old Jehovah's Witness with advanced stage renal cell carcinoma (RCC) who presented with profound anemia due to intractable bleeding from gastric metastasis. After repeated attempts with endoscopic and angiographic management, she underwent surgical palliation. Through this case, we developed 10-item evidence-based criteria for selecting patients for PS. OBJECTIVE: The study objective was to provide a review of pertinent literature for PS and identify evidence-based criteria for patient selection. These criteria were relevant for selecting this patient with metastatic RCC and may prove beneficial for selecting advanced cancer patients for PS. METHODS: A MEDLINE search revealed 175 publications relevant to PS. Among these, 17 articles defining patient selection criteria (PSC) were reviewed. A frequency-based analysis of each criterion was performed. Another search returned 30 cases of RCC gastric metastases from 25 published reports. Outcome analysis was determined by the Kaplan-Meier actuarial method. RESULTS: Ten criteria were identified: symptom control, prognosis, preoperative performance status, quality of life (QoL), tumor burden amenable to palliation, procedure-related morbidity and mortality, feasibility of nonsurgical therapies, anticipated hospitalization, requirement for additional palliation, and cost. This patient met all inclusion criteria and underwent a successful gastrectomy. Median survival for patients with RCC gastric metastasis was 20 months. CONCLUSIONS: This report illustrates an example of implementation of evidence-based criteria for selecting advanced cancer patients for PS. Validation of these criteria is warranted.

Pancreatic mucinous cystic neoplasm in a transgender patient.

BACKGROUND: Cystic pancreatic lesions are increasingly more frequent detected clinical entities. Mucinous cystic neoplasm (MCN) is a hormone-related pancreatic tumor (HRTP) with a strong predominance in young and middle-aged females. CASE PRESENTATION: Here, we present the case of a 31-year-old surgically transgendered female-to-male patient with a history of alcoholic pancreatitis, on chronic testosterone therapy. He was found to have a pancreatic MCN and underwent distal pancreatectomy and splenectomy. CONCLUSION: To our knowledge, this is the first reported case of a transgender patient with a history of hormone replacement therapy (HRT) and pancreatic MCN. We consider possible mechanisms for the pathogenesis to explain this patient's neoplasm.

Dialysis within 24 hours of transplant does not improve graft function.

OBJECTIVES: Grafts from extended criteria donors, donors after cardiac death, and elderly donors have an increased risk of delayed graft function, lower graft survival, longer hospital stay, higher costs, and increased medical sequelae. A modifiable risk factor for delayed graft function may be the performance of dialysis on the same day as renal transplant. We reviewed our institutional experience to determine whether dialysis performed within 24 hours of engraftment increased the incidence or length of delayed graft function. MATERIALS AND METHODS: We retrospectively reviewed our kidney transplants performed between 2008 and 2012. Preemptive transplants, transplants associated with peritoneal dialysis, potassium > 5 mmol/L, or living donors, and cases with insufficient information were excluded. Data collected included demographic, biochemical, donor, operative, and outcome variables (length of stay, length of delayed graft function, rejection, and a composite unfavorable outcome comprising cardiac and infectious events). Transplants that were associated with hemodialysis within 24 hours before transplant (study group) were compared with the remainder of the cohort (control group). RESULTS: A total of 205 renal transplants were reviewed. There were 144 of 205 transplants (70.24%) in the study group, and the others comprised the control group. The rate of delayed graft function was 31% for the study group and 29% for control groups (P = .4959). Mean length of delayed graft function was 5.8 days for the study group and 6.1 days for control group (P = .7323). Delayed graft function risk factors such as donor age, terminal creatinine, and machine perfusion rate were similarly distributed across both groups. CONCLUSIONS: Normokalemic patients who did or did not undergo dialysis within 24 hours before transplant had equivalent incidence and duration of delayed graft function, graft outcomes, and patient outcomes. Therefore, dialysis within 24 hours before transplant is unnecessary in the setting of normokalemia.

The anti-cancer peptide, PNC-27, induces tumor cell necrosis of a poorly differentiated non-solid tissue human leukemia cell line that depends on expression of HDM-2 in the plasma membrane of these cells.

GOALS: We have developed the anti-cancer peptide, PNC-27, which is a membrane-active peptide that binds to the HDM-2 protein expressed in the cancer cell membranes of solid tissue tumor cells and induces transmembrane pore formation in cancer, but not in normal cells, resulting in tumor cell necrosis that is independent of p53 activity in these cells. We now extend our study to non-solid tissue tumor cells, in this case, a primitive, possible stem cell human leukemia cell line (K562) that is also p53-homozygously deleted. Our purpose was twofold: to investigate if these cells likewise express HDM-2 in their plasma membranes and to determine if our anti-cancer peptide induces tumor cell necrosis in these non-solid tissue tumor cells in a manner that depends on the interaction between the peptide and membrane-bound HDM-2. PROCEDURES: The anti-cancer activity and mechanism of PNC-27, which carries a p53 aa12-26-leader sequence connected on its carboxyl terminal end to a trans-membrane-penetrating sequence or membrane residency peptide (MRP), was studied against p53-null K562 leukemia cells. Murine leukocytes were used as a non-cancer cell control. Necrosis was determined by measuring the lactate dehydrogenase (LDH) release and apoptosis was determined by the detection of Caspases 3 and 7. Membrane colocalization of PNC-27 with HDM-2 was analyzed microscopically using fluorescently labeled antibodies against HDM-2 and PNC-27 peptides. RESULTS: We found that K562 cells strongly express HDM-2 protein in their membranes and that PNC-27 co-localizes with this protein in the membranes of these cells. PNC-27, but not the negative control peptide PNC-29, is selectively cytotoxic to K562 cells, inducing nearly 100 percent cell killing with LDH release. In contrast, this peptide had no effect on the lymphocyte control cells. CONCLUSIONS: The results suggest that HDM-2 is expressed in the membranes of non-solid tissue tumor cells in addition to the membranes of solid tissue tumor cells. Since K-562 cells appear to be in the stem cell family, the results suggest that early developing tumor cells also express HDM-2 protein in their membranes. Since PNC-27 induces necrosis of K-562 leukemia cells and co-localizes with HDM-2 in the tumor cell membrane as an early event, we conclude that the association of PNC-27 with HDM-2 in the cancer cell membrane results in trans-membrane pore formation which results in cancer cell death, as previously discovered in a number of different solid tissue tumor cells. Since K562 cells lack p53 expression, these effects of PNC-27 on this leukemia cell line occur by a p53-independent pathway.

Retroperitoneal Castleman's disease: advocating a multidisciplinary approach for a rare clinical entity.

BACKGROUND: Castleman's disease is a rare and poorly understood disease entity that may resemble more common conditions and represents a clinical challenge to the treating surgeon. CASE PRESENTATION: In this report, we describe a case of a 61-year-old Caucasian woman with a symptomatic retroperitoneal mass. The specimen obtained from her resection contained a protuberant encapsulated mass, exhibiting microscopic features consistent with localized, unicentric Castleman's disease. These characteristics included architectural features and immunohistochemical findings consistent with the hyaline vascular variant of Castleman's disease. CONCLUSION: We report a very rare case of a retroperitoneal hyaline vascular type of Castleman's disease. We discuss the diagnostic dilemma Castleman's disease may present to the surgeon, with an emphasis on multidisciplinary management of these patients. We also review current data on pathogenesis, treatment and outcomes.