Cytokine receptor IL27RA is an NF-κB-responsive gene involved in CD38 upregulation in multiple myeloma

Multiple myeloma (MM) shows constitutive activation of canonical and noncanonical nuclear factor κB (NF-κB) signaling via genetic mutations or tumor microenvironment (TME) stimulations. A subset of MM cell lines showed dependency for cell growth and survival on the canonical NF-κB transcription factor RELA alone, suggesting a critical role for a RELA-mediated biological program in MM pathogenesis. Here, we determined the RELA-dependent transcriptional program in MM cell lines and found the expression of the cell surface molecules interleukin-27 receptor-α (IL-27Rα) and the adhesion molecule JAM2 to be responsive to RELA at the messenger RNA and protein levels. IL-27Rα and JAM2 were expressed on primary MM cells at higher levels than on healthy long-lived plasma cells (PCs) in the bone marrow. IL-27 activated STAT1, and to a lesser extent STAT3, in MM cell lines and in PCs generated from memory B cells in an IL-21-dependent in vitro PC differentiation assay. Concomitant activity of IL-21 and IL-27 enhanced differentiation into PCs and increased the cell-surface expression of the known STAT target gene CD38. In accordance, a subset of MM cell lines and primary MM cells cultured with IL-27 upregulated CD38 cell-surface expression, a finding with potential implications for enhancing the efficacy of CD38-directed monoclonal antibody therapies by increasing CD38 expression on tumor cells. The elevated expression of IL-27Rα and JAM2 on MM cells compared with that on healthy PCs may be exploited for the development of targeted therapeutic strategies that modulate the interaction of MM cells with the TME.

An MYC-Driven Vicious Circuit Is a Targetable Achilles' Heel in Lymphoma

SUMMARY

In this issue of Blood Cancer Discovery, Nakanishi et al. uncover a critical role for the elevated activity of the translation initiation factor eIF5A in the malignant growth of MYC-driven lymphoma. eIF5A is posttranslationally modified by hypusination through MYC oncoprotein-mediated hyperactivation of the polyamine-hypusine circuit, which may represent a promising therapeutic target because an enzyme of this circuit that is required for hypusinating eIF5A proved to be essential for lymphoma development. See related article by Nakanishi et al., p. 294 (4).

Oncolytic virus treatment differentially affects the CD56dim and CD56bright NK cell subsets in vivo and regulates a spectrum of human NK cell activity

Natural killer (NK) cells protect against intracellular infection and cancer. These properties are exploited in oncolytic virus (OV) therapy, where antiviral responses enhance anti-tumour immunity. We have analysed the mechanism by which reovirus, an oncolytic dsRNA virus, modulates human NK cell activity. Reovirus activates NK cells in a type I interferon (IFN-I) dependent manner, inducing STAT1 and STAT4 signalling in both CD56dim and CD56bright NK cell subsets. Gene expression profiling revealed the dominance of IFN-I responses and identified induction of genes associated with NK cell cytotoxicity and cell cycle progression, with distinct responses in the CD56dim and CD56bright subsets. However, reovirus treatment inhibited IL-15 induced NK cell proliferation in an IFN-I dependent manner and was associated with reduced AKT signalling. In vivo, human CD56dim and CD56bright NK cells responded with similar kinetics to reovirus treatment, but CD56bright NK cells were transiently lost from the peripheral circulation at the peak of the IFN-I response, suggestive of their redistribution to secondary lymphoid tissue. Coupled with the direct, OV-mediated killing of tumour cells, the activation of both CD56dim and CD56bright NK cells by antiviral pathways induces a spectrum of activity that includes the NK cell-mediated killing of tumour cells and modulation of adaptive responses via the trafficking of IFN-γ expressing CD56bright NK cells to lymph nodes.

Glycolysis and Fatty Acid Oxidation Inhibition Improves Survival in Glioblastoma

Glioblastoma (GBM) is the most aggressive adult glioma with a median survival of 14 months. While standard treatments (safe maximal resection, radiation, and temozolomide chemotherapy) have increased the median survival in favorable O(6)-methylguanine-DNA methyltransferase (MGMT)-methylated GBM (~21 months), a large proportion of patients experience a highly debilitating and rapidly fatal disease. This study examined GBM cellular energetic pathways and blockade using repurposed drugs: the glycolytic inhibitor, namely dicholoroacetate (DCA), and the partial fatty acid oxidation (FAO) inhibitor, namely ranolazine (Rano). Gene expression data show that GBM subtypes have similar glucose and FAO pathways, and GBM tumors have significant upregulation of enzymes in both pathways, compared to normal brain tissue (p < 0.01). DCA and the DCA/Rano combination showed reduced colony-forming activity of GBM and increased oxidative stress, DNA damage, autophagy, and apoptosis in vitro. In the orthotopic Gl261 and CT2A syngeneic murine models of GBM, DCA, Rano, and DCA/Rano increased median survival and induced focal tumor necrosis and hemorrhage. In conclusion, dual targeting of glycolytic and FAO metabolic pathways provides a viable treatment that warrants further investigation concurrently or as an adjuvant to standard chemoradiation for GBM.

Controlled infection with a therapeutic virus defines the activation kinetics of human natural killer cells in vivo

Human natural killer (NK) cells play an important role in anti-viral immunity. However, studying their activation kinetics during infection is highly problematic. A clinical trial of a therapeutic virus provided an opportunity to study human NK cell activation in vivo in a controlled manner. Ten colorectal cancer patients with liver metastases received between one and five doses of oncolytic reovirus prior to surgical resection of their tumour. NK cell surface expression of the interferon-inducible molecules CD69 and tetherin peaked 24-48 h post-infection, coincident with a peak of interferon-induced gene expression. The interferon response and NK cell activation were transient, declining by 96 h post-infection. Furthermore, neither NK cell activation nor the interferon response were sustained in patients undergoing multiple rounds of virus treatment. These results show that reovirus modulates human NK cell activity in vivo and suggest that this may contribute to any therapeutic effect of this oncolytic virus. Detection of a single, transient peak of activation, despite multiple treatment rounds, has implications for the design of reovirus-based therapy. Furthermore, our results suggest the existence of a post-infection refractory period when the interferon response and NK cell activation are blunted. This refractory period has been observed previously in animal models and may underlie the enhanced susceptibility to secondary infections that is seen following viral infection.

Human tumour immune evasion via TGF-β blocks NK cell activation but not survival allowing therapeutic restoration of anti-tumour activity

Immune evasion is now recognized as a key feature of cancer progression. In animal models, the activity of cytotoxic lymphocytes is suppressed in the tumour microenvironment by the immunosuppressive cytokine, Transforming Growth Factor (TGF)-β. Release from TGF-β-mediated inhibition restores anti-tumour immunity, suggesting a therapeutic strategy for human cancer. We demonstrate that human natural killer (NK) cells are inhibited in a TGF-β dependent manner following chronic contact-dependent interactions with tumour cells in vitro. In vivo, NK cell inhibition was localised to the human tumour microenvironment and primary ovarian tumours conferred TGF-β dependent inhibition upon autologous NK cells ex vivo. TGF-β antagonized the interleukin (IL)-15 induced proliferation and gene expression associated with NK cell activation, inhibiting the expression of both NK cell activation receptor molecules and components of the cytotoxic apparatus. Interleukin-15 also promotes NK cell survival and IL-15 excluded the pro-apoptotic transcription factor FOXO3 from the nucleus. However, this IL-15 mediated pathway was unaffected by TGF-β treatment, allowing NK cell survival. This suggested that NK cells in the tumour microenvironment might have their activity restored by TGF-β blockade and both anti-TGF-β antibodies and a small molecule inhibitor of TGF-β signalling restored the effector function of NK cells inhibited by autologous tumour cells. Thus, TGF-β blunts NK cell activation within the human tumour microenvironment but this evasion mechanism can be therapeutically targeted, boosting anti-tumour immunity.

The evolution of robotic general surgery

Surgical robotics in general surgery has a relatively short but very interesting evolution. Just as minimally invasive and laparoscopic techniques have radically changed general surgery and fractionated it into subspecialization, robotic technology is likely to repeat the process of fractionation even further. Though it appears that robotics is growing more quickly in other specialties, the changes digital platforms are causing in the general surgical arena are likely to permanently alter general surgery. This review examines the evolution of robotics in minimally invasive general surgery looking forward to a time where robotics platforms will be fundamental to elective general surgery. Learning curves and adoption techniques are explored. Foregut, hepatobiliary, endocrine, colorectal, and bariatric surgery will be examined as growth areas for robotics, as well as revealing the current uses of this technology.

Proteolytic activation of the cytotoxic phenotype during human NK cell development

NK cells induce apoptosis in target cells via the perforin-mediated delivery of granzyme molecules. Cytotoxic human NK cells can be generated by IL-15-mediated differentiation of CD34(+) cells in vitro and these cultures have been used extensively to analyze the development of the NK cell surface phenotype. We have used NK cell differentiation in vitro together with protease-deficient human NK cells to analyze the acquisition of the cytotoxic phenotype. Granzymes are synthesized as inactive zymogens and are proteolytically activated by the cysteine protease cathepsin C. Cathepsin C is also synthesized as a zymogen and activated by proteolysis. We show that human NK cells generated in vitro undergo granule exocytosis and induce the caspase cascade in target cells. IL-15 and stem cell factor (IL-15 plus SCF) induced the expression of the granzyme B and perforin genes and the activation of cathepsin C and granzyme B zymogens. Perforin activation is also mediated by a cysteine protease and IL-15 plus SCF-mediated differentiation was accompanied by perforin processing. However, cathepsin C-deficient human NK cells revealed that perforin processing could occur in the absence of cathepsin C activity. The combination of IL-15 plus SCF is therefore sufficient to coordinate the development of the NK cell surface phenotype with the expression and proteolytic activation of the cytotoxic machinery, reflecting the central role of IL-15 in NK cell development.

Expression of murine killer immunoglobulin-like receptor KIRL1 on CD1d-independent NK1.1(+) T cells

Three mouse killer immunoglobulin-like receptors (KIRs), namely, KIR3DL1, KIRL1, and KIRL2, have recently been identified in C56BL/6 (B6) mice. However, only two Kir genes are found in the B6 mouse genome sequence data base. To clarify this discrepancy, we cloned Kir cDNAs from multiple strains of mice. Sequencing of the cDNA clones showed that the Kir3dl1 gene is found in C3H/HeJ and CBA/J but not in B6 mice. Analysis of the single nucleotide polymorphism data base suggested that Kir3dl1 is the C3H/HeJ and CBA/J allele of Kirl1. We generated mAb to the recombinant KIRL1 protein to investigate its expression pattern. The anti-KIRL1 mAb bound to NK1.1(+) T cells but only very weakly or at undetectable levels to other lymphocytes including natural killer (NK) cells and conventional T cells. Among NK1.1(+) T cells, conventional NK T cells stained with CD1d tetramer did not significantly bind anti-KIRL1 mAb, whereas CD1d-tetramer-negative subset was KIRL1-positive. Furthermore, the expression of KIRL1 is readily detected on NK1.1(+) T cells from beta(2)-microglobulin-deficient B6 mice. Thus, KIRL1 is predominantly expressed on CD1d-independent NK1.1(+) T cells.

Traumatic diaphragmatic hernia presenting as a tension fecopneumothorax

Diaphragmatic injury with accompanying hernia is a well-documented complication associated with both penetrating and blunt trauma. It occurs in approximately 3% of abdominal injuries with a 2:1 ratio of penetrating to blunt trauma. Diagnosis requires a high index of suspicion since diaphragmatic injury can only reliably be ruled out by direct visualization, i.e., laparoscopy. Hence, delayed presentation with complications secondary to the injury is not uncommon. We discuss a case of a young man who presented in respiratory distress six years after a stab wound to the left chest. The patient was hypoxic, with a chest X-ray (CXR) demonstrating a pneumothorax with effusion. A chest tube was placed with a rush of air and foul-smelling purulent drainage. Work-up revealed incarcerated transverse colon in a diaphragmatic hernia. Celiotomy demonstrated necrotic colon in the chest with gross fecal contamination in both the chest and abdomen. The diaphragmatic defect was closed and a Hartmann's procedure performed. The patient did well postoperatively except for the development of an empyema, which resolved with conservative management. Our patient is the eleventh reported case of a tension fecopneumothorax resulting from traumatic diaphragmatic herniation. This paper reviews all cases including the diagnostic work-up, operative approach, and ex ected postoperative course of this unusual condition.

Computed tomography and ultrasonography in the diagnosis of appendicitis: when are they indicated?

HYPOTHESIS

Relative merits and indications exist for ultrasonography (US) and computed tomography (CT) in the diagnosis of appendicitis.

DESIGN

Prospective study.

SETTING

General community and tertiary care hospital.

METHODS

Ninety-nine patients (50 males and 49 females) were studied. Following consent, the initial disposition was recorded, designating the patient for operation, observation, or discharge from the hospital. Each patient was studied by CT and US. Studies were independently evaluated by 2 radiologists, and the results were designated as positive, negative, or equivocal. The surgeon reevaluated patients before and after learning the results of US and CT, recording whether the CT scan, US, or reexamination influenced the final disposition.

RESULTS

Fifty patients had appendicitis; 6 appendixes were perforated. The initial clinical impression called for 44 operations, 49 observations, and 6 discharges. Thirty-four patients had their treatment plan changed from the initial disposition. Ultrasonography did not affect the initial impression. In contrast, 18 patients were rediagnosed solely on CT scan findings. Seven patients were rediagnosed by reexamination. Of 44 patients initially designated for operation, the CT scan and reexamination spared 6 females from surgery; the negative appendectomy rate potentially decreased from 50% to 17% (P =.03). The CT scan, US, or reexamination failed to spare 2 males from exploration with negative results. Of the 49 patients initially designated for observation, 23 were rediagnosed after reevaluation, 13 were discharged from the hospital, and 10 underwent expedient operation. One patient was spared from inappropriate discharge from the hospital. The reliability of the CT scan was good, with high sensitivities and specificities. Equivocal scan results lowered the diagnostic value.

CONCLUSIONS

Selective use of a CT scan with a second examination can improve the diagnostic accuracy and management of suspected cases of appendicitis by (a) reducing the negative appendectomy rate in females, (b) moving patients from observation to earlier operation or discharge from the hospital, and (c) preventing inappropriate discharge of patients with appendicitis.

Metoclopramide versus ondansetron in prophylaxis of nausea and vomiting for laparoscopic cholecystectomy

BACKGROUND

Postoperative nausea and vomiting are significant problems in laparoscopic surgery. This double-blind, randomized, prospective trial compares the prophylactic use of metoclopramide, ondansetron, and placebo for the treatment of postoperative nausea and vomiting in patients undergoing outpatient laparoscopic cholecystectomy.

METHODS

Two hundred thirty-two patients aged 18 to 73 years were randomized into three groups. Patients received intravenously 10 mg of metoclopramide, 4 mg of ondansetron, or placebo in a double-blinded manner prior to surgery.

RESULTS

The incidence of nausea was 32% for metoclopramide, 45% for ondansetron, and 44% for placebo in the postanesthesia care unit or day surgery, which was not statistically significant. The incidence of vomiting was 8% for metoclopramide, 4% for ondansetron, and 22% for placebo in the postanesthesia care unit or day surgery. These differences were statistically significant when comparing both drugs to placebo but not when comparing both drugs to each other.

CONCLUSION

Prophylactic administration of metoclopramide or ondansetron significantly reduces the incidence of postoperative vomiting for laparoscopic cholecystectomy, but neither drug was found to be significantly more effective than the other. Metoclopramide is a more cost-effective treatment.

Preventing patient falls

Falls are among the most common, yet potentially preventable, adverse events experienced by patients in hospitals. Such serious outcomes as physical and emotional injury, increased dependence, admission to a long-term care facility, and poor quality of life can result from falling. Traditionally, elderly patients have been at highest risk for falling, with many falls resulting in serious injury. These injuries cost billions of dollars and expose hospitals and their staff to liability. As the elderly population continues to increase, it is imperative that falls and associated injuries be prevented whenever possible identification of nontraditional patients at high risk for falls is emerging in the professional literature. Nurses are the first line of care in prevention of falls. Educating nurses about risk factors, prevention strategies and application of fall index and fall injury statistics can improve the safety of fall-prone patients. Refining, modifying and individualizing fall risk factors and prevention interventions for traditional and nontraditional high-risk groups is a necessary focus for future research.