Acute Aortic Dissection Type A in Younger Patients (< 60 Years Old) - Does Full Arch Replacement Provide Benefits Compared to Limited Approach?

ABSTRACT Introduction: Acute aortic dissection Stanford type A (AADA) is a surgical emergency associated with high morbidity and mortality. Although surgical management has improved, the optimal therapy is a matter of debate. Different surgical strategies have been proposed for patients under 60 years old. This paper evaluates the postoperative outcome and the need for secondary aortic operation after a limited surgical approach (proximal arch replacement) vs. extended arch repair. Methods: Between January 2000 and January 2018, 530 patients received surgical treatment for AADA at our hospital; 182 were under 60 years old and were enrolled in this study - Group A (n=68), limited arch repair (proximal arch replacement), and group B (n=114), extended arch repair (> proximal arch replacement). Results: More pericardial tamponade (P=0.005) and preoperative mechanical resuscitation (P=0.014) were seen in Group A. More need for renal replacement therapy (P=0.047) was seen in the full arch group. Mechanical ventilation time (P=0.022) and intensive care unit stay (P<0.001) were shorter in the limited repair group. Thirty-day mortality was comparable (P=0.117). New onset of postoperative stroke was comparable (Group A four patients [5.9%] vs. Group B 15 patients [13.2%]; P=0.120). Long-term follow-up did not differ significantly for secondary aortic surgery. Conclusion: Even though young patients received only limited arch repair, the outcome was comparable. Full-arch replacement was not beneficial in the long-time follow-up. A limited approach is justified in the cohort of young AADA patients. Exemptions, like known Marfan syndrome and the presence of an intimal tear in the arch, should be considered.

Acute Aortic Dissection Type A in Younger Patients (< 60 Years Old) - Does Full Arch Replacement Provide Benefits Compared to Limited Approach?

INTRODUCTION: Acute aortic dissection Stanford type A (AADA) is a surgical emergency associated with high morbidity and mortality. Although surgical management has improved, the optimal therapy is a matter of debate. Different surgical strategies have been proposed for patients under 60 years old. This paper evaluates the postoperative outcome and the need for secondary aortic operation after a limited surgical approach (proximal arch replacement) vs. extended arch repair. METHODS: Between January 2000 and January 2018, 530 patients received surgical treatment for AADA at our hospital; 182 were under 60 years old and were enrolled in this study - Group A (n=68), limited arch repair (proximal arch replacement), and group B (n=114), extended arch repair (> proximal arch replacement). RESULTS: More pericardial tamponade (P=0.005) and preoperative mechanical resuscitation (P=0.014) were seen in Group A. More need for renal replacement therapy (P=0.047) was seen in the full arch group. Mechanical ventilation time (P=0.022) and intensive care unit stay (P<0.001) were shorter in the limited repair group. Thirty-day mortality was comparable (P=0.117). New onset of postoperative stroke was comparable (Group A four patients [5.9%] vs. Group B 15 patients [13.2%]; P=0.120). Long-term follow-up did not differ significantly for secondary aortic surgery. CONCLUSION: Even though young patients received only limited arch repair, the outcome was comparable. Full-arch replacement was not beneficial in the long-time follow-up. A limited approach is justified in the cohort of young AADA patients. Exemptions, like known Marfan syndrome and the presence of an intimal tear in the arch, should be considered.

Onset of pain to surgery time in acute aortic dissections type A: a mandatory factor for evaluating surgical results?

Objective: An acute aortic dissection type A (AADA) is a rare but life-threatening event. The mortality rate ranges between 18% to 28% and mortality is often within the first 24 h and up to 1%-2% per hour. Although the onset of pain to surgery time has not been a relevant factor in terms of research in the field of AADA, we hypothesize that a patient's preoperative conditions depend on the length of this time. Methods: Between January 2000 and January 2018, 430 patients received surgical treatment for acute aortic dissection DeBakey type I at our tertiary referral hospital. In 11 patients, the exact time point of initial onset of pain was retrospectively not detectable. Accordingly, a total of 419 patients were included in the study. The cohort was categorized into two groups: Group A with an onset of pain to surgery time < 6 h (n = 211) and Group B > 6 h (n = 208), respectively. Results: Median age was 63.5 years (y) ((IQR: 53.3-71.4 y); (67.5% male)). Preoperative conditions differed significantly between the cohorts. Differences were detected in terms of malperfusion (A: 39.3%; B: 23.6%; P: 0.001), neurological symptoms (A: 24.2%; B: 15.4%; P: 0.024), and the dissection of supra-aortic arteries (A: 25.1%; B: 16.8%; P: 0.037). In particular, cerebral malperfusion (A 15.2%: B: 8.2%; P: 0.026) and limb malperfusion (A: 18%, B: 10.1%; P: 0.020) were significantly increased in Group A. Furthermore, Group A showed a decreased median survival time (A: 1,359.0 d; B: 2,247.5 d; P: 0.001), extended ventilation time (A: 53.0 h; B: 44.0 h; P: 0.249) and higher 30-day mortality rate (A: 25.1%; B: 17.3%; P: 0.051). Conclusions: Patients with a short onset of pain to surgery time in cases of AADA present themselves not only with more severe preoperative symptoms but are also the more compromised cohort. Despite early presentation and emergency aortic repair, these patients show increased chances of early mortality. The "onset of pain to surgery time" should become a mandatory factor when making comparable surgical evaluations in the field of AADA.

Preoperative pericardial hematoma in patients with acute type A aortic dissection (AAAD): Do we need an adjusted treatment?

OBJECTIVE: An acute type A aortic dissection (AAAD) is a critical emergency and remains one of the most challenging diseases in cardiothoracic surgery. The existence of a pericardial hematoma caused by an aortic rupture can dramatically reduce the chances of survival (Jerzewski and Kulik in J Card Surg 29(4):529-530, 2014; Mehta et al. in Circulation 105(2):200-206, 2002; Gilon et al. in Am J Cardiol 103(7):1029-1031, 2009; Isselbacher et al. in Circulation 90(5):2375-2378, 1994). We assessed the surgical outcome of a high-risk group of patients with AAAD and a pericardial hematoma. METHODS: In this study we included 430 Patients (67% male; median age: 64 years) who received surgical treatment between January 2000 and January 2018 at our facility for acute aortic dissection DeBakey type I. We divided the cohort in two groups: Group A consisted of high-risk patients with a pericardial hematoma (n = 162) and Group B of patients without pericardial hematoma (n = 268). RESULTS: Patients with a preoperative pericardial hematoma had a significantly higher requirement for preoperative mechanical resuscitation (A: 21%; B: 1.5%; P: < 0.001) and were relevantly more frequently admitted to the operation theater with an intubated status (A: 19.8%; B: 8.6%; P: < 0.001). The incidence of visceral malperfusion differed significantly between both groups (A. 11.7%, B. 6:0%; P: 0.034). Limited aortic arch repair (proximal aortic arch replacement) was preferred in the high-risk group (A: 51.9%; B: 40.3%; P: 0.020). However, survival time was generally reduced in these patients (A: 7.5 y; B: 9.9 y). CONCLUSION: AAAD patients with preoperative pericardial hematoma present themselves in potentially lethal conditions, with a significantly higher rate of visceral malperfusion. Despite the existence of this risk factor, a limited arch repair was favored. We have proven that cardiac compression is associated with preoperative intubation and mechanical resuscitation. Patients with pericardial hematoma must be further evaluated for preoperative pericardial drainage. In the event of long transfer times to an aortic center a slow drainage should be discussed to prevent early mortality.

Stabilizing A Vascularized Autologous Matrix with Flexible Magnesium Scaffolds to Reconstruct Dysfunctional Left Ventricular Myocardium in a Large-Animal Feasibility Study.

The surgical reconstruction of dysfunctional myocardium is necessary for patients with severe heart failure. Autologous biomaterials, such as vascularized patch materials, have a regenerative potential due to in vivo remodeling. However, additional temporary mechanical stabilization of the biomaterials is required to prevent aneurysms or rupture. Degradable magnesium scaffolds could prevent these life-threatening risks. A left ventricular transmural defect was reconstructed in minipigs with a piece of the autologous stomach. Geometrically adaptable and degradable scaffolds made of magnesium alloy LA63 were affixed on the epicardium to stabilize the stomach tissue. The degradation of the magnesium structures, their biocompatibility, physiological remodeling of the stomach, and the heart's function were examined six months after the procedure via MRI (Magnetic Resonance Imaging), angiography, µ-CT, and light microscopy. All animals survived the surgery. Stable physiological integration of the stomach patch could be detected. No ruptures of the grafts occurred. The magnesium scaffolds showed good biocompatibility. Regenerative surgical approaches for treating severe heart failure are a promising therapeutic alternative to the currently available, far from optimal options. The temporary mechanical stabilization of viable, vascularized grafts facilitates their applicability in clinical scenarios.

Impact of preoperative malperfusion on postoperative outcomes in type A aortic dissection - importance of serum lactate estimation in ongoing malperfusion.

INTRODUCTION: Acute type A aortic dissection (ATAAD) is one of the most critical emergencies in cardiovascular surgery. Additional complications such as organ malperfusion can significantly decrease the chances of survival. Despite promptly performed surgical treatment, impaired organ perfusion may persist, thus close postoperative monitoring is recommended. But, is there a surgical consequence due to the existence of a preoperatively known malperfusion and is there a correlation between pre-, peri- and postoperative levels of serum lactate and proven malperfusion? METHODS: Between 2011 and 2018, 200 patients (66% male; median age: 62.5 years; interquartile range: +/-12.4 years) that received surgical treatment at our institution for an acute dissection DeBakey type I were enrolled in this study. The cohort was divided into two groups according to the preoperative existence of malperfusion and non-malperfusion. At least one kind of malperfusion occurred in 74 patients (Group A: 37%), while 126 patients (Group B: 63%) showed no evidence of malperfusion. Furthermore, lactate levels of both cohorts were differentiated into four periods: preoperative, intraoperative, 24 hours after surgery, and 2-4 days after surgery. RESULTS: The patients' status differed significantly prior to surgery. Group A (malperfusion) showed an elevated requirement for mechanical resuscitation (A: 10.8%; B: 5.6%; p: 0.173), were significantly more often admitted in an intubated state (A: 14.9%; B: 2.4%; p: 0.001) and showed higher incidences of stroke (A: 18.9% (n = 149); B: 3.2% (n = 4); p: 0.001). Levels of serum lactate from the preoperative period until days 2-4 were significantly increased in the malperfusion cohort at all times. CONCLUSIONS: Preexisting malperfusion due to ATAAD may significantly increase the chance of early mortality in patients with ATAAD. Serum lactate levels were a reliable marker for inadequate perfusion from admission until day 4 after surgery. Despite this, early intervention survival in this cohort remains limited.

Simulation of Aerosol and Droplet Spread during Upper Airway and Gastrointestinal Endoscopy.

BACKGROUND AND AIMS: Aerosols and droplets are the main vectors in transmission of highly contagious SARS-CoV-2. Invasive diagnostic procedures like upper airway and gastrointestinal endoscopy have been declared as aerosol-generating procedures. Protection of healthcare workers is crucial in times of the COVID-19 pandemic. METHODS: We simulated aerosol and droplet spread during upper airway and gastrointestinal endoscopy with and without physico-mechanical barriers using a simulation model. RESULTS: A clear plastic drape as used for central venous access markedly reduced visualized aerosol and droplet spread during endoscopy. CONCLUSION: A simple and cheap drape has the potential to reduce aerosol and droplet spread during endoscopy. In terms of healthcare worker protection, this may be important particularly in low- or moderate-income countries.

Left Ventricular Wall Reconstruction with Autologous Vascularized Tunica Muscularis of Stomach in a Porcine Pilot Model.

INTRODUCTION: Surgical replacement of dysfunctional cardiac muscle with regenerative tissue is an important option to combat heart failure. But, current available myocardial prostheses like a Dacron or a pericardium patch neither have a regenerative capacity nor do they actively contribute to the heart's pump function. This study aimed to show the feasibility of utilizing a vascularized stomach patch for transmural left ventricular wall reconstruction. METHODS: A left ventricular transmural myocardial defect was reconstructed by performing transdiaphragmatic autologous transplantation of a vascularized stomach segment in six Lewe minipigs. Three further animals received a conventional Dacron patch as a control treatment. The first 3 animals were followed up for 3 months until planned euthanasia, whereas the observation period for the remaining 3 animals was scheduled 6 months following surgery. Functional assessment of the grafts was carried out via cardiac magnetic resonance tomography and angiography. Physiological remodeling was evaluated histologically and immunohistochemically after heart explantation. RESULTS: Five out of six test animals and all control animals survived the complex surgery and completed the follow-up without clinical complications. One animal died intraoperatively due to excessive bleeding. No animal experienced rupture of the stomach graft. Functional integration of the heterotopically transplanted stomach into the surrounding myocardium was observed. Angiography showed development of connections between the gastric graft vasculature and the coronary system of the host cardiac tissue. CONCLUSIONS: The clinical results and the observed physiological integration of gastric grafts into the cardiac structure demonstrate the feasibility of vascularized stomach tissue as myocardial prosthesis. The physiological remodeling indicates a regenerative potential of the graft. Above all, the connection of the gastric vessels with the coronary system constitutes a rationale for the use of vascularized and, therefore, viable stomach tissue for versatile tissue engineering applications.

SOCIUS Mentoring-A Novel Course to Encourage Students for a Career as Surgical Oncologists.

Surgical disciplines are affected by an increasing shortage of young doctors. Studies show that formerly interested students decide against a career in surgical disciplines at the end of their studies or during practical year. Measures to counteract this development are urgently needed. As a joint project between gynecology, urology, and general surgery, SOCIUS mentoring was designed to prepare and encourage students for a career in surgical oncology. The structured curriculum of SOCIUS mentoring contains six modules, including surgical skills, soft skills, mentoring, theory, clinical visitation, and congress participation and runs over one year. Effects on confidence towards physician skills and plans for a future career were evaluated with questionnaires. After participation, students reported increased confidence in surgical and soft skills. In addition, participants noted that they have specified their career goals and gained more confidence in surgery, as well as seeing more development potential for a career in surgery. We describe the implementation of a novel extracurricular program for motivated students that combines individual mentoring with surgical and soft skills training. Due to its modular structure, this concept can easily be transferred to other disciplines. SOCIUS mentoring, with its combination of mentoring and skills training, is a promising measure to prepare and motivate students for their surgical career and thus counteract the shortage of young talent.

Improving Emergency Department Patient-Physician Conversation Through an Artificial Intelligence Symptom-Taking Tool: Mixed Methods Pilot Observational Study.

BACKGROUND: Establishing rapport and empathy between patients and their health care provider is important but challenging in the context of a busy and crowded emergency department (ED). OBJECTIVE: We explore the hypotheses that rapport building, documentation, and time efficiency might be improved in the ED by providing patients a digital tool that uses Bayesian reasoning-based techniques to gather relevant symptoms and history for handover to clinicians. METHODS: A 2-phase pilot evaluation was carried out in the ED of a German tertiary referral and major trauma hospital that treats an average of 120 patients daily. Phase 1 observations guided iterative improvement of the digital tool, which was then further evaluated in phase 2. All patients who were willing and able to provide consent were invited to participate, excluding those with severe injury or illness requiring immediate treatment, with traumatic injury, incapable of completing a health assessment, and aged <18 years. Over an 18-day period with 1699 patients presenting to the ED, 815 (47.96%) were eligible based on triage level. With available recruitment staff, 135 were approached, of whom 81 (60%) were included in the study. In a mixed methods evaluation, patients entered information into the tool, accessed by clinicians through a dashboard. All users completed evaluation Likert-scale questionnaires rating the tool's performance. The feasibility of a larger trial was evaluated through rates of recruitment and questionnaire completion. RESULTS: Respondents strongly endorsed the tool for facilitating conversation (61/81, 75% of patients, 57/78, 73% of physician ratings, and 10/10, 100% of nurse ratings). Most nurses judged the tool as potentially time saving, whereas most physicians only agreed for a subset of medical specialties (eg, surgery). Patients reported high usability and understood the tool's questions. The tool was recommended by most patients (63/81, 78%), in 53% (41/77) of physician ratings, and in 76% (61/80) of nurse ratings. Questionnaire completion rates were 100% (81/81) by patients and 96% (78/81 enrolled patients) by physicians. CONCLUSIONS: This pilot confirmed that a larger study in the setting would be feasible. The tool has clear potential to improve patient-health care provider interaction and could also contribute to ED efficiency savings. Future research and development will extend the range of patients for whom the history-taking tool has clinical utility. TRIAL REGISTRATION: German Clinical Trials Register DRKS00024115; https://drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00024115.

Train early and with deliberate practice: simple coronary surgery simulation platform results in fast increase in technical surgical skills in residents and students.

OBJECTIVES: The amount of intense and focused training with the specific goal to improve performance (i.e. deliberate practice) is a predictor of expert-level performance in multiple domains of psychomotor skill learning. Simulation training improves surgical skills in cardiac surgery. We established a training programme that enables early surgical exposure and assessment. We investigated the training effects in coronary surgery simulations in trainees with different levels of surgical experience. METHODS: The early surgical exposure and assessment programme comprises a low- and high-fidelity simulation, self-organized training, instructed workshops and a stepwise challenge increase. Performance was assessed with a multidimensional skill matrix using video recordings. Two groups of trainees [students (N = 7), 1-/2-year residents (N = 6)] completed introductory training (pretraining, level 1) and two 3-week training periods (levels 2 and 3). Fellows (N = 6) served as controls. Residents and students underwent deliberate practice training with specific training targets. Fellows performed regularly scheduled coronary surgery cases. Entry and exit assessments were conducted for levels 2 and 3. RESULTS: Fellows did not improve overall performance. Residents and students showed significant improvements in both technical accuracy and completion times. Residents reached an overall performance level comparable to fellows. Students reached similar accuracy of surgical skills with longer completion times [level 3 exit score/time: fellows 27 (24-29)/min; residents 27 (21-30)/min, P = 0.94; students 17 (17-25)/min, P = 0.068]. CONCLUSIONS: Deliberate practice training resulted in a fast and substantial increase in surgical skills in residents and students. Unexperienced residents reach performance levels of fellows. Deliberate practice simulation programmes should be a mandatory component of surgical training.

Engineering of biodegradable magnesium alloy scaffolds to stabilize biological myocardial grafts.

OBJECTIVE: Regenerative bioprostheses are being investigated for replacement of dysfunctional myocardium worldwide. The aim of this study was to develop a degradable magnesium structure to mechanically support the delicate biological grafts during the early remodeling phase. METHODS: Sheets of magnesium alloys (LA33, LA63 and AX30) were manufactured into scaffolds by abrasive water jet cutting. Thereafter, their surface properties, corrosion kinetics, and breakage behaviors were investigated. RESULTS: The magnesium alloy LA63 sheets proved superior to the other alloys in terms of load cycles (lc) until break of the specimens (LA63: >10 Mio lc; AX30: 676,044±220,016 lc; LA33: 423,558±210,063 lc; p<0.01). Coating with MgF led to better protection than coating with MagPass. Less complex, yet sufficiently flexible scaffolds were less prone to early breakage. A slow traverse rate during water jet cutting resulted in the lowest burr, but in a widening of the kerf width from 615±11 µm at 500 mm/min to 708±33 µm at 10 mm/min (p<0.01). CONCLUSION: The findings on alloy composition, coating, structural geometry and manufacturing parameters constitute a basis for clinically applicable magnesium scaffolds. The use of stabilized, regenerative myocardium prostheses could save the patients from severe morbidity and eventually death.

Surgical site infections--economic consequences for the health care system.

PURPOSES: Unfortunately, surgical site infections (SSIs) are a quite common complication and represent one of the major causes of postoperative morbidity and mortality, and may furthermore lead to enormous additional costs for hospitals and health care systems. METHODS: In order to determine the estimated costs due to SSIs, a MEDLINE search was performed to identify articles that provide data on economic aspects of SSIs and compared to findings from a matched case-control study on costs of SSIs after coronary bypass grafting (CABG) in a German tertiary care university hospital. RESULTS: A total of 14 studies on costs were found. The additional costs of SSI vary between $3,859 (mean) and $40,559 (median). Median costs of a single CABG case in the recently published study were $49,449 (€36,261) vs. $18,218 (€13,356) in controls lacking infection (p < 0.0001). The median reimbursement from health care insurance companies was $36,962 (€27,107) leading to a financial loss of $12,482 (€9,154) each. CONCLUSION: Costs of SSIs may almost triple the individual overall health care costs and those additional charges may not be sufficiently covered. Appropriate measures to reduce SSI rates must be taken to improve the patient's safety. This should also diminish costs for health care systems which benefits the entire community.

ΔNp73ß is oncogenic in hepatocellular carcinoma by blocking apoptosis signaling via death receptors and mitochondria.

BACKGROUND & AIMS: p73 belongs to the p53 family of transcription factors known to regulate cell cycle and apoptosis. The Trp73 gene has two promoters that drive the expression of two major p73 isoform subfamilies: TA and ΔN. In general, TAp73 isoforms show proapoptotic activities, whereas members of the N-terminally truncated (ΔN) p73 subfamily that lack the transactivation domain show antiapoptotic functions. We found that upregulation of ΔNp73 in hepatocellular carcinoma (HCC) correlated with reduced survival. Here, we investigated the molecular mechanisms accounting for the oncogenic role of ΔNp73 in HCC. RESULTS: ΔNp73ß can directly interfere with the transcriptional activation function of the TA (containing the transactivation domain) isoforms of the p53 family and consequently inhibit transactivation of proapoptotic target genes. Interference of ΔNp73ß with apoptosis-/chemosensitivity takes place at several levels of apoptosis signaling. ΔNp73ß negatively regulates the genes encoding for the death receptors CD95, TNF-R1, TRAIL-R2 and TNFRSF18. Furthermore, ΔNp73ß represses the genes encoding caspase-2, -3, -6, -8 and -9. Concomitantly, ΔNp73ß inhibits apoptosis emanating from mitochondria. CONCLUSIONS: Thus, ΔNp73 expression in HCC selects against both the death receptor and the mitochondrial apoptosis activity of the TA isoforms. Our data suggest that ΔNp73 isoforms repress apoptosis-related genes of the extrinsic and intrinsic apoptosis signaling pathways thereby contributing to chemoresistance. The clinical importance of these data is evidenced by our finding that the ΔNp73ß target gene signature can predict the prognosis of patients suffering from HCC.

Dominant negative (DeltaN) p63alpha induces drug resistance in hepatocellular carcinoma by interference with apoptosis signaling pathways.

p63 belongs to the family of p53-related transcription factors expressing a variety of isoforms. The Trp63 gene has two promoters that drive the expression of two major p63 isoform subfamilies. Isoforms of the TAp63 subfamily show pro-apoptotic activities, whereas members of the N-terminally truncated (DeltaN) p63 subfamily have anti-apoptotic functions. We have previously shown an important role for TAp63alpha in the induction of apoptosis and chemosensitivity of hepatocellular carcinoma (HCC). Here, we investigated the molecular mechanisms accounting for the oncogenic role of DeltaNp63alpha in HCC. DeltaNp63alpha can directly interfere with the transcriptional activation function of the TA (containing the transactivation domain) isoforms of the p53 family and consequently inhibit transactivation of pro-apoptotic target genes. DeltaNp63alpha negatively regulates the genes encoding for the death receptor CD95 and the pro-apoptotic Bcl-2 family member BAX. Thus, DeltaNp63alpha expression in HCC interferes with both the death receptor and the mitochondrial apoptosis activity of the TA isoforms. In addition and of clinical relevance, DeltaNp63alpha inhibits activation of p53 family target genes and apoptosis induced by chemotherapeutic drugs. Chemotherapeutic treatment induces expression of Bax, Bim, Noxa, Puma and Perp; this is antagonized by DeltaNp63alpha. Our data suggest that the DeltaNp63alpha isoform represses apoptosis-related genes of the extrinsic and intrinsic apoptosis signaling pathways, thereby contributing to chemoresistance of HCC.

Interference with the p53 family network contributes to the gain of oncogenic function of mutant p53 in hepatocellular carcinoma.

Whereas the hallmark of wild-type p53 is its tumor suppressor activity, tumor-associated mutant p53 proteins can exert novel anti-apoptotic gain-of-function activities, which confer a selective advantage upon tumor cells harboring such mutations. We investigated the molecular mechanisms of mutant p53 gain-of-function in hepatocellular carcinoma with special emphasis on the interaction of mutant p53 gain-of-function proteins with the p53 family members p63 and p73. Mutant forms of p53, namely the hot-spot mutants p53R143A, p53R175D, p53R175H, p53R248W, and p53R273H, acquire anti-apoptotic gain-of-function in hepatocellular carcinoma by repressing the activity of genes regulating both, the extrinsic apoptosis pathway initiated by ligation of death receptors and the intrinsic/mitochondrial apoptosis pathway. In the presence of mutated p53, the CD95L-CD95 apoptotic pathway is markedly attenuated. This is due to repression of CD95 gene transcription by mutant p53. In addition, these mutants repress the expression of the Bax gene and attenuate mitochondria-mediated apoptosis signaling. Furthermore, and of clinical relevance, these gain-of-function mutants are anti-apoptotic due to their inhibitory interaction with the pro-apoptotic p53 family members TAp63 and TAp73. p53 gain-of-function mutants significantly decrease activation of pro-apoptotic target genes by wild-type p53, TAp63, and TAp73. This contributes to the ability of cancer cells to withstand DNA damage-induced apoptosis. Interference with the interaction of p53 gain-of-function mutants with TAp63 or TAp73 may thus sensitize hepatocellular carcinoma to elimination by therapy.

Curcumin inhibits the growth, induces apoptosis and modulates the function of pituitary folliculostellate cells.

The polyphenol curcumin (diferuloylmethane) is the active componenet of the spice plant Curcuma longa and has been shown to exert multiple actions on mammalian cells. We have studied its effect on folliculostellate (FS) TtT/GF mouse pituitary cells, representative of a multifunctional, endocrine inactive cell type of the anterior pituitary. Proliferation of TtT/GF cells was inhibited by curcumin in a monolayer cell culture and in the colony formation assay in soft agar. Fluorescence-activated cell-sorting (FACS) analysis demonstrated curcumin-induced cell cycle arrest at G(2)/M accompanied by inhibition of cyclin D(1) protein expression. Curcumin had a small effect on necrosis of TtT/GF cells, but it mainly stimulated apoptosis as demonstrated by FACS analysis (Annexin V-fluorescein isothiocyannate/7-aminoactinomycin D staining). Curcumin-induced apoptosis involved suppression of Bcl-2, stimulation of cleaved caspase-3 and induction of DNA fragmentation. Functional studies on FS cell-derived compounds showed that curcumin inhibited mRNA synthesis and release of angiogenic vascular endothelial growth factor-A (VEGF-A). Immune-like functions of FS cells were impaired since curcumin downregulated Toll-like receptor 4, reduced nuclear factor-kappaB expression and suppressed bacterial endotoxin-induced interleukin-6 (IL-6) secretion. The inhibitory action of curcumin on VEGF-A and IL-6 production was also found in primary rat pituitary cell cultures, in which FS cells are the only source of these proteins. The observed effects of curcumin on FS cell growth, apoptosis and functions may have therapeutic consequences for the intrapituitary regulation of hormone production and release as well as for pituitary tumor pathogenesis.

Chemotherapy-induced apoptosis in hepatocellular carcinoma involves the p53 family and is mediated via the extrinsic and the intrinsic pathway.

We investigated the downstream mechanisms by which chemotherapeutic drugs elicit apoptosis in hepatocellular carcinoma (HCC). Genomic signatures of HCC cell lines treated with different chemotherapeutic drugs were obtained. Analyses of apoptosis pathways were performed and RNA interference was used to evaluate the role of the p53 family. Endogenous p53, p63 and p73 were upregulated in response to DNA damage by chemotherapeutic drugs. Blocking p53 family function led to chemoresistance in HCC. Stimulation and blocking experiments of the CD95-, the TNF- and the TRAIL-receptor systems revealed that cytotoxic drugs, via the p53 family members as transactivators, can trigger expression of each of these death receptors and consequently sensitize HCC cells toward apoptosis. Furthermore, our findings demonstrate a link between chemotherapy, the p53 family and the mitochondrial apoptosis pathway in HCC. Chemotherapeutic treatment induces expression of proapoptotic Bcl-2 family members like Bax and BCL2L11 and the expression of Apaf1, BNIP1, Pdcd8 and RAD. Thus, upon DNA damage, p53, p63 and p73 promote apoptosis via the extrinsic and the intrinsic signaling pathway. In addition, not only proapoptotic genes were upregulated, but also genes known to exert antiapoptotic functions. Bleomycin-induced upregulation of BCL-XL/BCLXL1 and MDM2 suggests that it is the ratio of proapoptotic and antiapoptotic proteins that regulates the apoptosis response of HCC cells toward chemotherapy, thereby playing a decisive role between treatment sensitivity vs. drug resistance. The clinical importance of these data is evidenced by our finding that the bleomycin target gene signature can predict the prognosis of patients suffering from HCC.

Active transcription of the human FAS/CD95/TNFRSF6 gene involves the p53 family.

p63 and p73 express two main classes of isoforms: isoforms which contain the transactivation domain (TAp73 and TAp63) executing transcriptional activity and dominant-negative isoforms which are truncated at the NH2-terminus acting as operant inhibitors of TAp73, TAp63 and wild-type p53, and thus possessing oncogenic potential. Like wt p53, TAp63 and TAp73 isoforms transactivate target genes that activate apoptosis signaling pathways. In an attempt to understand how the CD95 gene is regulated by the p53 family, we investigated the contributions of a p53-responsive element (RE) within the first intron of the CD95 gene as well as three elements within the promoter. The intronic element conferred transcriptional activation by p53, TAp63 and TAp73 and cooperated with the p53-REs in the promoter of the CD95 gene. Cooperation between the p53-REs in the promoter and the intronic p53-binding site resulted in maximal transcriptional activation of the CD95 gene by the p53 family.