DUSP16 promotes cancer chemoresistance through regulation of mitochondria-mediated cell death

Drug resistance is a major obstacle to the treatment of most human tumors. In this study, we find that dual-specificity phosphatase 16 (DUSP16) regulates resistance to chemotherapy in nasopharyngeal carcinoma, colorectal cancer, gastric and breast cancer. Cancer cells expressing higher DUSP16 are intrinsically more resistant to chemotherapy-induced cell death than cells with lower DUSP16 expression. Overexpression of DUSP16 in cancer cells leads to increased resistance to cell death upon chemotherapy treatment. In contrast, knockdown of DUSP16 in cancer cells increases their sensitivity to treatment. Mechanistically, DUSP16 inhibits JNK and p38 activation, thereby reducing BAX accumulation in mitochondria to reduce apoptosis. Analysis of patient survival in head & neck cancer and breast cancer patient cohorts supports DUSP16 as a marker for sensitivity to chemotherapy and therapeutic outcome. This study therefore identifies DUSP16 as a prognostic marker for the efficacy of chemotherapy, and as a therapeutic target for overcoming chemoresistance in cancer.

Light-independent M1 macrophage polarization by photosensitizer-loaded protein corona on gold nanorods

Aim: To establish a light-independent functionality of gold nanorods (AuNRs) with a human serum (HS) protein corona loaded with photosensitizer Chlorin e6 (AuNR-HS-Ce6) in M1 polarization of macrophages. Methods: RT-qPCR and ELISA were used to determine gene and protein expression, respectively. Uptake of AuNR-HS-Ce6 was determined via flow cytometry, inductively coupled plasma mass spectrometry and fluorescence microscopy. Cell viability was determined using PrestoBlue^® cell viability assay. Results: An increase in M1 gene and protein expression was observed in AuNR-HS-Ce6-treated macrophages. Delivery of high Ce6 payload via AuNR-HS-Ce6 was the primary contributor toward M1 polarization. Finally, DLD-1 cells treated with conditioned media from AuNR-HS-Ce6-treated macrophages showed significantly reduced proliferation. Conclusion: Our study suggests an immunomodulatory potential of Ce6 in inducing light-independent M1 polarization outside of its role as a photosensitizer.

Protective Function of Mitogen-Activated Protein Kinase Phosphatase 5 in Aging- and Diet-Induced Hepatic Steatosis and Steatohepatitis

Nonalcoholic fatty liver disease is currently the most common liver disease and is a leading cause of liver-related morbidity and mortality. However, its pathogenesis remains largely unclear. We previously showed that mice deficient in mitogen-activated protein kinase (MAPK) phosphatase 5 (MKP5) spontaneously developed insulin resistance and glucose intolerance, which are associated with visceral obesity and adipose tissue inflammation. In this study, we discovered that mice deficient in MKP5 developed more severe hepatic steatosis and steatohepatitis with age or with feeding on a high-fat diet (HFD) compared to wild-type (WT) mice, and this was associated with increased expression of proinflammatory cytokines and collagen genes. Increased p38 activation in MKP5 knockout (KO) liver compared to that in WT liver was detected, which contributed to increased expression of lipid droplet-associated protein cell death-inducing DFF45-like effector A (CIDEA) and CIDEC/fat-specific protein 27 but not CIDEB through activating transcription factor 2 (ATF2). In addition, MKP5 KO liver had higher peroxisome proliferator-activated receptor gamma (PPARγ) expression compared with WT liver. On the other hand, overexpression of MKP5 or inhibition of p38 activation in hepatocytes resulted in reduced expression of PPARγ. Inhibition of p38 resulted in alleviation of hepatic steatosis in KO liver in response to HFD feeding, and this was associated with reduced expression of CIDEA, CIDEC, and proinflammatory cytokines. Conclusion: MKP5 prevents the development of nonalcoholic steatohepatitis by suppressing p38-ATF2 and p38-PPARγ to reduce hepatic lipid accumulation, inflammation, and fibrosis.

Monocyte-derived factors including PLA2G7 induced by macrophage-nasopharyngeal carcinoma cell interaction promote tumor cell invasiveness

The non-keratinizing undifferentiated subtype of nasopharyngeal carcinoma (NPC) is a malignancy characterized by an intimate relationship between neoplastic cells and a non-neoplastic lymphoid component. Tumor-associated macrophages (TAMs) foster tumor progression through production of soluble mediators that support proliferation, angiogenesis, survival and invasion of malignant cells. However, the role of macrophages in the progression of NPC remains poorly understood. This study aims to investigate the functional and phenotypic changes that occur to macrophages in macrophage-NPC cell co-culture systems, and how these changes influence tumor cells. We found that monocytes, including THP-1 cells and primary human monocytes, co-cultured with C666-1 NPC cells upregulate expression of pro-inflammatory cytokines at the early stages, followed by the induction of metastasis-related genes and interferon-stimulated genes at the later stage of coculture, indicating that TAMs are “educated” by NPC cells for cancer progression. Importantly, the induction of these factors from the TAMs was also found to enhance the migratory capabilities of the NPC cells. We have also identified one of these macrophage-derived factor, phospholipase A2 Group 7 (PLA2G7), to be important in regulating tumor cell migration and a novel tumor-promoting factor in NPC. Further studies to characterize the role of PLA2G7 in tumor metastasis may help determine its potential as a therapeutic target in NPC.

Regulatory Roles of MAPK Phosphatases in Cancer

The mitogen-activated protein kinases (MAPKs) are key regulators of cell growth and survival in physiological and pathological processes. Aberrant MAPK signaling plays a critical role in the development and progression of human cancer, as well as in determining responses to cancer treatment. The MAPK phosphatases (MKPs), also known as dual-specificity phosphatases (DUSPs), are a family of proteins that function as major negative regulators of MAPK activities in mammalian cells. Studies using mice deficient in specific MKPs including MKP1/DUSP1, PAC-1/DUSP2, MKP2/DUSP4, MKP5/DUSP10 and MKP7/DUSP16 demonstrated that these molecules are important not only for both innate and adaptive immune responses, but also for metabolic homeostasis. In addition, the consequences of the gain or loss of function of the MKPs in normal and malignant tissues have highlighted the importance of these phosphatases in the pathogenesis of cancers. The involvement of the MKPs in resistance to cancer therapy has also gained prominence, making the MKPs a potential target for anti-cancer therapy. This review will summarize the current knowledge of the MKPs in cancer development, progression and treatment outcomes.

A refined agonist pharmacophore for protease activated receptor 2

Protease activated receptor 2 (PAR(2)) is a G protein-coupled receptor implicated in inflammation and cancer. Only a few peptide agonists are known with greater potency than the native agonist SLIGRL-NH(2). Here we report 52 peptide agonists of PAR(2), 26 with activity at sub-micromolar concentrations, and one being iodinated for radioligand experiments. Potency was highest when the N- or C-termini of SLIGRL-NH(2) were modified, pointing to a new ligand pharmacophore model that may aid development of drug-like PAR(2) modulators.

A comparison of ON-PUMP vs OFF-PUMP coronary artery bypass surgery among low, intermediate, and high-risk patients: the Hartford Hospital experience

BACKGROUND

Off-pump coronary artery bypass (OP-CAB) graft surgery is being used with increasing frequency. This study was designed to compare OP-CAB outcomes with conventional surgical revascularization using cardiopulmonary bypass (CPB) in patients with varying risk categories at a high-volume center.

METHODS AND RESULTS

Between 1/1/1999 and 1/31/2001, bypass surgery was performed on 1,312 patients, including 348 OP-CAB cases and 964 CPB cases. Compared to CPB cases, OP-CAB patients were more likely to be female and had a lower incidence of three vessel coronary artery disease, prior percutaneous intervention, and prior bypass surgery. Postoperatively, OP-CAB patients had a lower incidence of renal failure and prolonged ventilatory support, as well as a lower composite endpoint of inhospital mortality, perioperative myocardial infarction, cerebrovascular accident, and/or renal failure. In addition, OP-CAB patients required fewer transfusions and had a shorter total length of hospital stay. In general, morbidity and mortality increased in both OP-CAB and CPB groups with increasing Parsonnet score.

CONCLUSIONS

OP-CAB surgery is a safe and effective alternative to conventional coronary artery bypass graft (CABG) surgery, with a lower incidence of major in-hospital adverse clinical events and a decreased requirement for medical resources. Adverse OP-CAB outcomes correlate well with pre-operative Parsonnet Score.

Long-term survivors of heart transplantation: the Hartford Hospital experience

Heart transplantation has been a clinical program at Hartford Hospital for the past 15 years, resulting in 206 transplants. The five-year survival rate is 69% and is 43% at 10 years. The first recipient is surviving and has had full rehabilitation. Thirteen patients have survived 10 years or more. Advances in immunosuppression are ongoing and will result in further long-term survivors. Graft vasculopathy and lack of organ donation are current problems.

A better long-term outcome in cardiac transplant recipient with a history of previous open heart operations

OBJECTIVE

To investigate the effect of previous open heart operations (POHO) on the outcome of heart transplantation (HTX).

METHODS

Between November 1984 and May 1996, HTX was performed on 151 patients at Hartford Hospital. Among them, 61 patients had previous open heart operations (POHO) (group A), and 90 did not (group B). The average follow-up period was 1615 +/- 1185 days for group A and 1330 +/- 1125 days for group B. The recipient age was 55 +/- 10 years for group A and 48 +/- 12 years for group B (P < 0.01). There were 17 patients (26%) in group A and 14 (50%) in group B who were over 60 years of age. There was more coronary artery disease (74% versus 37%, P < 0.001) as etiology, and more diabetics in group A (P < 0.02).

RESULTS

The time for cardiopulmonary bypass (133 +/- 20 min versus 106 +/- 18 min, P < 0.01) and aortic clamp time (73 +/- 16 min versus 61 +/- 13 min, P < 0.01) were longer in group A. The operative mortality (within 30 days) was 0 and 2.2%, and the cumulative deaths were 16 (26%) and 43 (48%) respectively for group A and group B (P < 0.01). The causes of death were (group A vs group B): infection (31% vs 26%), rejection (13% vs 28%, P < 0.05), malignancy (25% vs 16%), cardiac event (6% vs 14%) and others (25% vs 16%). In patients over 60, there were 4 deaths (24%) in group A and 7 (50%) in group B. The difference was not significant. No patients died of rejection in this subgroup. The actuarial survival rates in group A versus group B were: 1 year, 93% versus 83%; 2 years, 85% versus 74%; 3 years, 81% versus 71%; 5 years, 76% versus 58%; and 10 years, 57% versus 24% (P < 0.01).

CONCLUSION

The survival rate in patients who had POHO is much higher than that in patients who had HTX as their primary operation.

Retrograde flush and cold storage for twenty-two to twenty-five hours lung preservation with and without prostaglandin E1

BACKGROUND

Our previous study showed that retrograde flush through the left atrium is better than antegrade flush in 6-hour lung preservation. Whether it is feasible in long-term lung preservation is not clear. Several studies suggested that prostaglandin E1 may not be necessary in retrograde flush because of the low vascular resistance on the venous side. This study evaluates the effects of retrograde flush and prostaglandin E1 in 24-hour lung preservation.

METHODS

Canine donor lungs were retrograde flushed with University of Wisconsin solution. Group A (n = 7) was pretreated with prostaglandin E1. No prostaglandin E1 was used in group B (n = 7). After flush and cold storage at 4 degrees C for 22 to 25 hours, left lung allotransplantation was performed. Measurements were taken before transplantation (baseline), and at 10, 30, 60, and 120 minutes after transplantation while the right pulmonary artery was occluded.

RESULTS

After 120 minutes of reperfusion, the oxygen tension and carbon dioxide tension were 643 +/- 24 and 37 +/- 3 mm Hg in group A and 600 +/- 29 and 37 +/- 3 mm Hg in group B, respectively (p = NS). Pulmonary artery pressure (group A vs group B) was 20 +/- 1 versus 28 +/- 2 mm Hg (p < 0.01); right atrium pressure: 4 +/- 1 versus 8 +/- 1 mm Hg (p < 0.01); left pulmonary vascular resistance: 1109 +/- 51 versus 1525 +/- 133 dyne.sec.cm-5 (p < 0.05); airway resistance: 22 +/- 1 versus 24 +/- 1 cm H2O/L/sec (p = NS); lung dynamic compliance: 30 +/- 1 versus 26 +/- 1 cc/cm (p < 0.05) respectively. As compared with the baseline (19 +/- 1), airway resistance was significantly increased after 2 hours of reperfusion in group B (p < 0.05). Electron microscopy revealed that type I pneumocytes, capillary endothelial cells, and epithelial cells of bronchi were well preserved and the contents of lamellar bodies of type II pneumocyte were reduced.

CONCLUSIONS

Canine lung was well preserved by retrograde flush and cold storage with University of Wisconsin solution after 24 hours preservation. Pretreatment of prostaglandin E1 is helpful in reducing pulmonary vascular resistance and airway resistance and improving lung dynamic compliance.

Organ transplantation at the Hartford Transplant Center

Over 1,243 organ transplants have been performed at the Hartford Transplant Center over the past two decades. Survival in kidney, heart, liver, and pancreas patients is at or above the national average. Hartford was one of the first centers to use triple immunosuppression, which significantly improved survival in kidney transplantation. For recipients of kidneys from living related donors and cadaveric kidneys, two-year actuarial graft survival has been 98% and 83%, respectively, over the last five years. For heart and liver transplants, two-year survival has been 79% and 67%, respectively. Despite high success rates at most transplant centers, donor organs remain scarce. This problem needs to be addressed through increased cooperative efforts in the health-care community and the general public.

Retrograde versus antegrade flush in canine left lung preservation for six hours

BACKGROUND

Retrograde flush through the left atrium is now used by some investigators in clinical lung preservation. However, to date there are no studies which compare its result with that of routine antegrade flush.

METHODS

Mongrel dogs were divided into two groups: antegrade group (n = 7) and retrograde group (n = 8). After flush and 6 hours of cold storage in Euro-Collins solution, the left lung was transplanted in weight matched recipients, and their right pulmonary artery was then clamped at 10-, 30-, 60-, and 120-minute intervals for 10 minutes to test the lung function. The ultrastructure of lungs in both groups were also studied.

RESULTS

Results showed the following (antegrade group versus retrograde group): the wet/dry ratio of the transplanted lung was 7.14 +/- 0.15 versus 6.33 +/- 0.20 (p < 0.01); the arterial oxygen tension (mm Hg) was 389 +/- 42 versus 534 +/- 23 (p < 0.05) and 370 +/- 51 versus 580 +/- 37 (p < 0.01) at 60 and 120 minutes, respectively. The peak airway pressure (cm H2O) was 23.4 +/- 0.8 versus 20.6 +/- 0.6 (p < 0.05) and 23.7 +/- 0.6 versus 21.3 +/- 0.8 (p < 0.05) at 10 and 60 minutes, respectively. Electron microscopic studies showed that at the end of preservation, type I and type II pneumocytes and capillaries were normal in both groups. Occluded capillaries with red blood cells were found in the antegrade group. After reperfusion, damaged epithelium and thicker air-blood barrier were found in the antegrade group.

CONCLUSIONS

Retrograde flush offers a better lung preservation with less edema, decreased airway resistance, and improved oxygenation as compared with the antegrade group in 6 hours lung preservation.

A comparison of 10% pentastarch and 5% albumin in patients undergoing open-heart surgery

Colloids are useful in cardiac surgery to increase preload and improve cardiac output without the risks associated with blood transfusions. Pentastarch is a new low-molecular weight hydroxyethyl starch compound under investigation for this purpose. The authors compared, in a randomized fashion, 12 patients who received pentastarch and 17 patients who received albumin for volume expansion after open-heart surgery. During the 24-hour study period there was no significant difference between the two groups with respect to systemic blood pressure, mean arterial pressure, cardiac index, right atrial pressure, and pulmonary capillary wedge pressure, with the exception of a higher mean arterial pressure and systolic blood pressure at 4 hours in the albumin group and higher heart rate at 12 hours in the pentastarch group. In addition, postoperative prothrombin time, partial thromboplastin time, fibrinogen, platelets, and factor VIII levels were not significantly different between the two groups. There were no complications attributed to colloid administration. The hemodynamic parameters were further evaluated in a subset of 6 pentastarch and 9 albumin patients who received the first 500 mL of colloid in a similar time frame and under similar clinical conditions. The patients who received pentastarch showed a significantly greater increase in cardiac index than did the patients who received albumin. No significant change in other parameters were noted between the two groups. The authors conclude that pentastarch is as safe as albumin and may be a more effective volume expander than albumin when used in open-heart surgery patients.

Traumatic intramyocardial dissection secondary to significant blunt chest trauma: a case report

The case of a patient with delayed mitral regurgitation and right coronary artery traumatic injury in association with intramyocardial dissection without rupture or pseudoaneurysm is presented. These findings evolved secondary to blunt chest trauma and were confirmed by cardiac ultrasound scanning, magnetic resonance imaging, and cardiac catheterization. Successful surgical correction was facilitated with this combination of diagnostic testing.

Single-pump techniques for assisted circulation in cardiogenic shock: experimental evaluation and case report

Acute cardiogenic shock or bridging to transplantation often involves the need for circulatory and cardiac support systems that are more effective than the intraaortic balloon pump. Biventricular failure, which is present in many cases, is generally treated with total cardiac replacement or with a complex of pumps and oxygenator that makes application difficult. With the goal of developing a universally applicable method of cardiac and circulatory support, we undertook a series of canine experiments designed to evaluate the effect of various treatment methods on survival, hemodynamics, and metabolic function. The series involved 123 dogs, in which cardiogenic shock was induced by means of multiple coronary artery ligations. The individual animals were then subjected to bypass, treated medically, or left untreated, depending on random selection. Each treatment lasted for 4 hours and was followed by a 2-hour period of observation. The following single-pump methods were tested: 1) left ventricular (LV) bypass, 2) left atrial (LA) bypass, 3) left ventricular and right atrial (LV + RA) bypass, 4) left atrial and right atrial (LA + RA) bypass, 5) LV + RA bypass, plus treatment with substrates (cysteine and ribose), and 6) LV + RA bypass, plus treatment with fluosol. Each bypass system incorporated a single reservoir and a centrifugal pump, and blood was returned to a femoral artery. Medical therapy consisted of either 1) treatment with sodium nitroprusside alone or 2) treatment with substrates alone. With respect to survival and hemodynamic effects (as reflected by oxygen consumption), LV + RA bypass and LA + RA bypass proved superior. During the posttreatment period, LV + RA bypass was associated with the highest survival rates and, therefore, with the most satisfactory recovery of myocardial or cardiac function. Despite the limited desaturation produced during venous shunting from the right atrium, perfusion of the entire body and consumption of oxygen were least in the LV + RA bypass group. The addition of substrates, or even of fluosol, caused a reduction in oxygen consumption. Our experience also includes one clinical case in which LA + RA bypass was used to support a 57-year-old man for 32 hours, after left atrial bypass alone proved inadequate. The dual-chamber technique brought about an improvement not only in hemodynamics but also in blood-gas values and pH. On the basis of this case and the canine experiments, we conclude that LV + RA and LA + RA bypass techniques offer safe, effective means of long-term temporary support for patients in severe cardiogenic shock.

Quality care and cost-effectiveness. An organized approach to problem solving

The reflexive approach to rising hospital costs and decreased revenue is to balance the budget by curtailing expenses. This places budgetary limitations on personnel, supplies, and equipment and ultimately has an impact on the quality of care. An alternative approach is to modify traditional practice patterns so that quality is preserved and costs are reduced. We reviewed elective class I and II coronary artery bypass graft surgery on a cost basis to identify potential problems. High costs in blood and blood-product usage were identified. An in-depth analysis of practice patterns was conducted, and comparisons were made between data from our hospital and other institutions. Modifications that improved quality and reduced costs were designed. Blood and blood-product usage was reduced from an average of 9.2 U to 3.4 U per case, resulting in an estimated cost avoidance of $111,286 per year. No cost advantage was observed with the use of cell savers, membrane oxygenators, or automated coagulation analysis in these routine short pump run surgeries. Though not cost-effective, the cell saver did allow the salvage of 2 U of blood per case. Mediastinal drainage systems (Sorenson) as well as reeducation regarding the safe, albeit low, hematocrit (no transfusions for hematocrits above 25% [0.25]) were effective in eliminating unnecessary use of potentially dangerous and expensive blood products.

Comparative penetration of cefonicid and cefazolin into the atrial appendage and pericardial fluid of patients undergoing open-heart surgery

The penetration of cefonicid and cefazolin into cardiac tissue was compared after a single 30-mg/kg dose in 30 patients undergoing aortocoronary artery bypass graft surgery. Samples of the right atrial appendage, pericardial fluid, and serum were obtained at various times and assayed for drug content. The concentrations of cefonicid in serum and the atrial appendage were at least twice those observed for cefazolin at a given time after a dose. The mean (+/- standard deviation) atrial appendage-serum ratio was 0.47 +/- 0.14 for cefonicid and 0.34 +/- 0.06 for cefazolin (P less than 0.005). Pericardial fluid concentrations of cefonicid were slightly lower than those observed in patients receiving cefazolin (P greater than 0.05). A single intravenous dose of cefonicid provides high and sustained concentrations in serum and cardiac tissue and thus may be useful in antibiotic prophylaxis of certain surgical procedures; however, further study of the efficacy of this agent in the prevention and treatment of infections associated with Staphylococcus spp. is needed.

Penetration of ceforanide and cefamandole into the right atrial appendage, pericardial fluid, sternum, and intercostal muscle of patients undergoing open heart surgery

Doses of 30 mg of ceforanide or cefamandole per kg were administered intravenously to 26 patients just before their chests were opened for coronary artery bypass or cardiac valve replacement surgery. Samples of right atrial appendage, pericardial fluid, plasma, aortic wall, intercostal muscle, and sternum were obtained at different times after the antibiotic was injected, and these samples were assayed for cephalosporin concentration. For ceforanide the pre-bypass plasma half-life was 2.5 h, and the atrial appendage half-life was 2.1 h; for cefamandole the pre-bypass plasma half-life was 0.75 h and the atrial appendage half-life was 0.72 h. At 3 h the concentrations of ceforanide and cefamandole in atrial appendages were 28.0 and 5.0 micrograms/g, respectively. Ceforanide achieved higher and more sustained concentrations in other tissues than cefamandole. Considering the minimal inhibitory concentrations of these drugs for staphylococci, cefamandole and ceforanide should provide adequate protection against infection by these organisms for the duration of the surgical procedure.

Infection of cardiac suture line after ventricular aneurysmectomy. Report of two cases

Two cases of sepsis following ventricular aneurysmectomy are presented. In both, the source of sepsis was an infected caridac suture line in which Teflon felt strips were used to reinforce the closure. One patient had a pseudoaneurysm and a chronic empyema of the left side of the chest, and the second had a ventriculocutaneous fistula. Early operation with removal of the foreign body is warranted in this major complication of a ventricular aneurysmectomy.