GCN2 kinase activation by ATP-competitive kinase inhibitors

Small-molecule kinase inhibitors represent a major group of cancer therapeutics, but tumor responses are often incomplete. To identify pathways that modulate kinase inhibitor response, we conducted a genome-wide knockout (KO) screen in glioblastoma cells treated with the pan-ErbB inhibitor neratinib. Loss of general control nonderepressible 2 (GCN2) kinase rendered cells resistant to neratinib, whereas depletion of the GADD34 phosphatase increased neratinib sensitivity. Loss of GCN2 conferred neratinib resistance by preventing binding and activation of GCN2 by neratinib. Several other Food and Drug Administration (FDA)-approved inhibitors, such erlotinib and sunitinib, also bound and activated GCN2. Our results highlight the utility of genome-wide functional screens to uncover novel mechanisms of drug action and document the role of the integrated stress response (ISR) in modulating the response to inhibitors of oncogenic kinases.

Ibrutinib Unmasks Critical Role of Bruton Tyrosine Kinase in Primary CNS Lymphoma

Bruton tyrosine kinase (BTK) links the B-cell antigen receptor (BCR) and Toll-like receptors with NF-κB. The role of BTK in primary central nervous system (CNS) lymphoma (PCNSL) is unknown. We performed a phase I clinical trial with ibrutinib, the first-in-class BTK inhibitor, for patients with relapsed or refractory CNS lymphoma. Clinical responses to ibrutinib occurred in 10 of 13 (77%) patients with PCNSL, including five complete responses. The only PCNSL with complete ibrutinib resistance harbored a mutation within the coiled-coil domain of CARD11, a known ibrutinib resistance mechanism. Incomplete tumor responses were associated with mutations in the B-cell antigen receptor-associated protein CD79B. CD79B-mutant PCNSLs showed enrichment of mammalian target of rapamycin (mTOR)-related gene sets and increased staining with PI3K/mTOR activation markers. Inhibition of the PI3K isoforms p110α/p110δ or mTOR synergized with ibrutinib to induce cell death in CD79B-mutant PCNSL cells.Significance: Ibrutinib has substantial activity in patients with relapsed or refractory B-cell lymphoma of the CNS. Response rates in PCNSL were considerably higher than reported for diffuse large B-cell lymphoma outside the CNS, suggesting a divergent molecular pathogenesis. Combined inhibition of BTK and PI3K/mTOR may augment the ibrutinib response in CD79B-mutant human PCNSLs. Cancer Discov; 7(9); 1018-29. ©2017 AACR.See related commentary by Lakshmanan and Byrd, p. 940This article is highlighted in the In This Issue feature, p. 920.

Molecular Pathways: Isocitrate Dehydrogenase Mutations in Cancer

IDH1 and IDH2 are homodimeric enzymes that catalyze the conversion of isocitrate to α-ketoglutarate (α-KG) and concomitantly produce reduced NADPH from NADP(+) Mutations in the genes encoding IDH1 and IDH2 have recently been found in a variety of human cancers, most commonly glioma, acute myeloid leukemia (AML), chondrosarcoma, and intrahepatic cholangiocarcinoma. The mutant protein loses its normal enzymatic activity and gains a new ability to produce the "oncometabolite" R(-)-2-hydroxyglutarate (R-2-HG). R-2-HG competitively inhibits α-KG-dependent enzymes which play crucial roles in gene regulation and tissue homeostasis. Expression of mutant IDH impairs cellular differentiation in various cell lineages and promotes tumor development in cooperation with other cancer genes. First-generation inhibitors of mutant IDH have entered clinical trials, and have shown encouraging results in patients with IDH-mutant AML. This article summarizes recent progress in our understanding of the role of mutant IDH in tumorigenesis.Clin Cancer Res; 22(8); 1837-42. ©2016 AACR.

Oxovanadium-based inhibitors can drive redox-sensitive cytotoxicity in neuroblastoma cells and synergise strongly with buthionine sulfoximine

In a wide range of neuroblastoma-derived lines oxovanadium compounds such as bis(maltolato)oxovanadium(IV) (BMOV) are cytotoxic. This is not explained by oxidative stress or inhibition of ion channels. Genotoxicity is unlikely given that a p53 response is absent and p53-mutant lines are also sensitive. Cytotoxicity is inhibited by N-acetyl cysteine and glutathione ester, indicating that BMOV action is sensitive to cytoplasmic redox and thiol status. Significantly, combining BMOV with glutathione synthesis inhibition greatly enhances BMOV-induced cell death. This combination treatment triggers high AKT pathway activation, highlighting the potential functional importance of PTP inhibition by BMOV. AKT activation itself, however, is not required for cytotoxicity. Oxovanadium compounds may thus represent novel leads as p53-independent therapeutics for neuroblastoma.

An inhibitor of mutant IDH1 delays growth and promotes differentiation of glioma cells

The recent discovery of mutations in metabolic enzymes has rekindled interest in harnessing the altered metabolism of cancer cells for cancer therapy. One potential drug target is isocitrate dehydrogenase 1 (IDH1), which is mutated in multiple human cancers. Here, we examine the role of mutant IDH1 in fully transformed cells with endogenous IDH1 mutations. A selective R132H-IDH1 inhibitor (AGI-5198) identified through a high-throughput screen blocked, in a dose-dependent manner, the ability of the mutant enzyme (mIDH1) to produce R-2-hydroxyglutarate (R-2HG). Under conditions of near-complete R-2HG inhibition, the mIDH1 inhibitor induced demethylation of histone H3K9me3 and expression of genes associated with gliogenic differentiation. Blockade of mIDH1 impaired the growth of IDH1-mutant--but not IDH1-wild-type--glioma cells without appreciable changes in genome-wide DNA methylation. These data suggest that mIDH1 may promote glioma growth through mechanisms beyond its well-characterized epigenetic effects.

Tyrosine phosphatase inhibitors combined with retinoic acid can enhance differentiation of neuroblastoma cells and trigger ERK- and AKT-dependent, p53-independent senescence

Retinoic acid (RA)-induced differentiation therapy is partially successful in neuroblastoma treatment. We found that a novel combination of vanadium-based PTP inhibitors with RA induced extensive differentiation in neuroblastoma cells. In contrast to RA alone, this led to either permanent differentiation or senescence after 14days of combined treatment followed by chemical removal. Senescence was dependent in part on synergistic AKT and ERK activation. p21 was also strongly induced, but in contrast to oncogene-induced senescence, p53 was not activated. Vanadium-based inhibitors thus serve strongly to enhance RA's ability to drive differentiation and a novel form of senescence in neuroblastoma cells.

Efficacy of palonosetron (PAL) compared to other serotonin inhibitors (5-HT3R) in preventing chemotherapy-induced nausea and vomiting (CINV) in patients receiving moderately or highly emetogenic (MoHE) treatments: Systematic review and meta-analysis

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Background: Chemotherapy-induced nausea and vomiting (CINV) are frequent side effects of cancer treatment, with negative effects on quality of life. CINV may be acute (occurring within 24 hours after the chemotherapy) or delayed (up to 7 days after it). There are currently five serotonin inhibitors (5-HT3R) available on the market. PAL has the longer half-life, but there are controversies regarding if a better control of CINV (particularly delayed) is obtained with it. This controversy is reflected in recommendations of practice guidelines. Objective: To perform a systematic review and meta-analysis of all randomized controlled trials comparing a single intravenous dose of PAL 0,25mg with other 5-HT3R in patients receiving MoHE chemotherapy. Methods: We searched several databases, including MEDLINE, EMBASE, LILACS, and CENTRAL. The primary endpoints were the incidence of acute and delayed nausea and vomiting. The side effects of each treatment were analyzed. A subgroup analysis on the impact of added corticosteroids was performed.The results of individual studies were pooled in a meta-analysis, using the RevMan 5.1 software. The results are expressed as Risk Ratio (RR) and the correspondent 95% Confidence Interval (CI). Results: We included 4 studies, with 1,298 patients. PAL was compared to ondansetron, granisetron and dolasetron. Patients in PAL group had less nausea, either acute (RR=0.75; CI= 0.64 to 0.88; P = 0.0004) or delayed (RR= 0.73; CI= 0.66 to 0.82; P < 0.00001). They also had less acute vomiting (RR = 0.78; CI= 0.67 to 0.90; P = 0.0008) and delayed vomiting (RR= 0.75; CI= 0.67 to 0.84; P < 0.00001). There were no statistical differences in side effects like headache (RR = 0.83; P = 0.29), dizziness (RR = 0.40; P = 0.12), constipation (RR = 1.35; P = 0.30) or diarrhea (RR = 0.67; P = 0.44). Patients receiving PAL presented less nausea and vomiting regardless of the use of corticoids. There was no statistical heterogeneity in the analises. Conclusions: PAL was more effective than the other 5-HT3R in preventing acute and delayed CINV in patients receiving MoHE treatments, regardless of the use of concomitant corticosteroids.

[Table: see text]

Laparoscopic adrenalectomy for malignancy

Background

Controversy exists as to whether laparoscopic adrenalectomy should be performed for malignant or potentially malignant tumours affecting the adrenals.

Methods

This was a retrospective analysis of all patients undergoing laparoscopic adrenalectomy at this institution from 1993 to 1999. Patients were classified by their preoperative diagnosis and analysed with respect to their final pathological diagnosis, operation and postoperative course.

Results

Some 121 patients underwent 133 laparoscopic adrenalectomies. Preoperative classification was type I (benign disease; 67 patients), type II (possibly malignant disease; 46 patients) and type III (malignant disease; eight patients). After operation, 11 patients had malignancy on pathological diagnosis including all eight patients with known preoperative malignancy (one adrenocortical carcinoma (3 × 3 cm) presenting as a virilizing tumour, two neuroblastomas, one lymphoma, one bilateral staged adrenalectomy for metastatic colon cancer, two metastatic lung cancers and one metastatic renal cell carcinoma). One patient with adrenocortical cancer (8 × 6 cm) had incorrect preoperative classification by cytology (type I; oncocytoma). Two of 14 patients with Cushing's adrenal tumour (type II) had adrenocortical cancer (12 × 9 cm and 3 × 3 cm). Mean length of stay was 1·8 days in patients with malignancy. No procedure was converted to open adrenalectomy and no significant complications were encountered. Only the four patients with adrenocortical carcinoma had a recurrence (two required open re-resection 3 months and 2 years after initial operation, one had laparoscopic re-resection 2 years after operation for local recurrence and one presented with recurrence 1 year after operation).

Conclusion

Forty-five per cent of patients undergoing laparoscopic adrenalectomy may be classified as having potentially malignant disease (type II or III). Most malignant tumours of the adrenals can be treated laparoscopically, but adrenocortical carcinomas are at high risk of recurrence after laparoscopic adrenalectomy.

Bisphosphonates in multiple myeloma

BACKGROUND

Multiple myeloma is a disease characterized by the neoplastic proliferation of a clone of plasma cells that can lead to bone destruction. Bisphosphonates are specific inhibitors of osteoclastic activity. Therefore, there is a pharmacological basis for their use in multiple myeloma. However, the exact clinical role of bisphosphonates in multiple myeloma remains unclear.

OBJECTIVES

Primary: to determine whether adding bisphosphonates to standard therapy in multiple myeloma decreases skeletal-related morbidity (pathological fractures), skeletal-related mortality and overall mortality. Secondary: to determine the effects of bisphosphonates on pain, quality of life and incidence of hypercalcemia.

SEARCH STRATEGY

We searched MEDLINE (1966 - June 2001), LILACS (1982 - June 2001), EMBASE (1974 - December 2000) and the Cochrane Controlled Trials Register (all years, latest Issue 03/2001) to identify all randomized trials in multiple myeloma. All of these references were accessed in order to identify trials related to the use of bisphosphonates in myeloma. All relevant references in each article were also scanned. We also performed a handsearch of relevant meeting proceedings from 1993 to 2000. Additionally, manufacturers of bisphosphonates and researchers in the field were contacted.

SELECTION CRITERIA

Randomised trials with a parallel design on the use of bisphosphonate in myeloma compared with placebo or no treatment as a control group.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial eligibility, methodological quality and abstracted data. A third reviewer checked all data after the extraction was completed. Statistical heterogeneity was tested using random and fixed effect models. All pooled data are reported using Peto odds ratios and, when appropriate, as absolute risk reduction and the number needed to treat to prevent or to cause a pathological event.

MAIN RESULTS

Eleven trials were included with 1113 patients analysed in bisphosphonates groups, and 1070 analysed in control groups. There was no significant statistical heterogeneity among trials for the endpoints selected for comparison in this review. The pooled analysis of the published evidence demonstrated the beneficial effect of bisphosphonates on prevention of pathological vertebral fractures [OR=0.59 (95% confidence interval (CI) 0.45-0.78); P=0.0001] and on amelioration of pain [OR = 0.59 (95%CI 0.46-0.76); P=0.00005]. However, the analysis of the effect of bisphosphonates on pain was based on clinically heterogeneous data and must be interpreted with caution. Although there was no statistical heterogeneity between groups, the benefit was most apparent with clodronate and pamidronate. In absolute terms, the result may be interpreted to mean that 10 (95%CI 7-20) patients with multiple myeloma should be treated to prevent one vertebral fracture, and 11 (95%CI 7-28) to prevent one patient experiencing pain. We found no significant effect of bisphosphonates on mortality, on the reduction of non-vertebral fractures or on the incidence of hypercalcemia. There were no significant adverse effects associated with the administration of bisphosphonates. Our results are based on the extraction of published data, which were sometimes poorly reported, and thus the results should be understood as the best possible summation of available evidence.

REVIEWER'S CONCLUSIONS

Adding bisphosphonates to the treatment of myeloma reduces pathological vertebral fractures and pain but - from the published evidence - not mortality. On current evidence, clodronate or pamidronate may be the preferred agents.

Mitochondrial activity in XTC.UC1 cells derived from thyroid oncocytoma

Thyroid oncocytoma is characterized by the presence of oncocytes containing abnormally large numbers of mitochondria. However, the relationship between the abundance of mitochondria and the pathogenesis of the tumors is unknown. Recently, a new cell line, named XTC.UC1, has been derived from a metastasis of thyroid oncocytoma. We have studied the metabolism and the gene expression profile of the mitochondria in XTC.UC1 cells, using B-CPAP cells as controls. There were no signs of mitochondrial respiratory chain defects or uncoupling between the respiratory chain and adenosine triphosphate (ATP) production. In XTC.UC1 cells, mtDNA transcripts were increased more than fivefold than in controls, in parallel with a 3.6-fold increase in mtDNA content. Finally, in spite of the glycolytic metabolism induced by the culture medium, the mitochondria of XTC.UC1 cells possess the phenotype of oncocytic cells with hypertrophic mitochondria, higher respiratory enzyme activity and higher mtDNA content than in controls. XTC.UC1 cells may therefore offer a useful model for investigating the coordination of the nuclear and mitochondrial genomes, in the context of thyroid tumors.

Nausea and vomiting following thyroid and parathyroid surgery

STUDY OBJECTIVES

To determine the incidence of postoperative nausea and vomiting (PONV) following thyroid and parathyroid surgery. To determine whether PONV is reduced when propofol is used for maintenance of anesthesia as compared to isoflurane and to evaluate the costs and resource consumption associated with these two anesthetic regimens.

DESIGN

Randomized, prospective study.

SETTING

University-affiliated hospital--a referral center for endocrinologic surgery.

PATIENTS

118 ASA physical status I and II patients, aged 18 years and older, undergoing elective thyroid or parathyroid surgery.

INTERVENTIONS

Patients received either isoflurane (0.5 to 1.3% end-tidal) or propofol (50 to 200 micrograms/kg/min) for maintenance of anesthesia. All patients received propofol for induction of anesthesia, succinylcholine or vecuronium, nitrous oxide, and fentanyl. Prophylactic antiemetics were not administered. Postoperative pain was treated with ketorolac, fentanyl, or acetaminophen.

MEASUREMENTS AND MAIN RESULTS

Signs and symptoms of nausea and vomiting were graded on a four point scale as 1 = no nausea; 2 = mild nausea; 3 = severe nausea; 4 = retching and/or vomiting. Grades 3 and 4 were grouped together as PONV. The combined incidence of PONV was 54% over the 24-hour postoperative evaluation period. PONV was significantly more common in patients receiving isoflurane than propofol for maintenance of anesthesia (64% vs. 44%). In women (n = 87), the incidence of PONV was significantly greater in those patients who received isoflurane than those who received propofol for maintenance (71% vs. 42%). However, in men (n = 31), there was no significant difference in PONV between anesthetic regimens (47% with isoflurane vs. 50% with propofol). There were no differences in the duration of stay in the postanesthesia care unit, time to discharge from the hospital, or local wound complications (hematomas) between groups. The use of propofol for maintenance of anesthesia was associated with an additional cost, relative to the isoflurane group, of $54.26 per patient.

CONCLUSION

Patients undergoing thyroid or parathyroid surgery are at high risk for the development of PONV. Propofol for maintenance of anesthesia, although more expensive than isoflurane, reduces the rate of PONV in women.

The role of growth factors in proliferation and invasion of thyroid cancer

A growing literature has established the close association between tumor progression and growth regulatory aberrations in cancer cells. Most studies have focused on the phenomenon, that advanced tumors or metastases have lost the sensitivity to growth inhibitors. Metastasis are the primary cause of death in patients with differentiated thyroid cancer. Proliferation and differentiation of the thyroid was supposed to be under the major control of only a single hormone (thyroid stimulating hormone). However, we and others have shown that a complex network of various growth factors regulates growth and invasion of thyroid cancer cells. Our findings highlight two aberrations of growth regulation which may favour progression of malignancy and acquisition of metastatic competence: i) resistence to growth factor inhibitors and ii) growth autonomy of metastatic thyroid cancer cells.

Clinical reactivation of herpes simplex virus type 2 infection in seropositive pregnant women with no history of genital herpes

OBJECTIVE

To determine the risk for genital herpes and asymptomatic herpes simplex virus (HSV) shedding in late pregnancy and delivery in a population of HSV type 2 (HSV-2)-seropositive but previously asymptomatic pregnant women.

DESIGN

A prospective inception cohort study.

PARTICIPANTS

A total of 1355 pregnant women with no history of genital herpes referred from three private obstetrics practices between November 1985 and June 1988.

MAIN OUTCOME MEASURES

Confidential questionnaires evaluated sexual risk factors in relation to HSV-2 serologic status as determined by Western blot analysis. Herpes simplex virus shedding was determined by viral culture of the cervix and vulva and of any suspicious lesions.

RESULTS

Antibody to HSV-2 was detected in 439 of 1355 pregnant women (32%) with no history of genital herpes. Asymptomatic HSV shedding was detected in 5 of 1160 cultures (0.43%) obtained in late pregnancy and during delivery. A first episode of clinical genital herpes was recognized by 43 of 264 HSV-2-seropositive women (16%) during their pregnancy.

CONCLUSIONS

Serologic evidence of unknown HSV-2 infection was common in pregnant women without a history of genital herpes. Asymptomatic viral shedding in these women occurred at a rate similar to that seen in women with symptomatic genital HSV-2 infection. To improve recognition of genital herpes near term, obstetricians should counsel pregnant women about the high prevalence and mild and diverse symptoms of genital HSV-2 infection.

Set-point for parathyroid hormone release increases with postmaturational aging in the rat

The plasma concentration of immunoreactive PTH (iPTH) increases with postmaturational aging in both humans and animals. In the present study we determined the basal, maximally stimulated, and maximally suppressed levels of iPTH and the concentration of whole blood ionized calcium sufficient to produce half-maximal suppression of the plasma concentration of iPTH (set-point for PTH release) in male Fischer 344 rats aged 3, 6, 12, 18, 24, and 28 months. Basal iPTH increased 2.3-fold from 3 to 28 months of age, whereas basal blood ionized calcium remained unchanged. The set-point for PTH release increased steadily and significantly (P < 0.001) from 1.19 +/- 0.09 mM at 3 months to 1.37 +/- 0.13 mM at 24 months and then declined slightly to 1.32 +/- 0.11 mM at 28 months of age. Basal iPTH correlated significantly with set-point. Neither maximally stimulated nor maximally suppressed iPTH levels showed any significant change with advancing age. These results suggest that the age-related increase in basal plasma iPTH in the rat may be in part a consequence of an increase in the set-point for PTH release.

A new method with high sensitivity and specificity for localization of abnormal parathyroid glands

A novel method for localization of abnormal parathyroid glands involving color-processing of nuclear scintigrams of the neck after injection of Thallium-201 and Technetium pertechnetate is presented with surgical correlation. Preoperative localization of single parathyroid adenomas was successful in 88% of previously unoperated patients and in 85.7% of those with adenomas not located at previous surgery. Eighty-three per cent of glands with secondary hyperplasia, 66% of glands with primary hyperplasia, and one carcinoma were localized. No abnormal studies were seen in non-hyperparathyroid hypercalcemia, and no false positive studies were seen. Localization appeared related to larger adenomas (300-5000 mg), although one of 60 mg was localized. Color-comparison dual-isotype scintigraphy was useful for localization of parathyroid adenomas and hyperplastic glands and exceeded the reported sensitivity of either ultrasonography or computerized tomography. It deserves wider evaluation in preoperative management of at least hyperparathyroidism of the primary or persistent types.

Localization of parathyroid adenoma by computed tomography

Sixteen consecutive patients with the clinical diagnosis of hyperparathyroidism, nine with and seven without previous surgery, had computed tomography (CT) examinations preoperatively to evaluate the use of CT in localizing parathyroid adenomas. The patients were scanned at 5 mm intervals from the level of the hyoid bone to the lung apex. Scanning of the mediastinum was performed at 10 mm intervals from apex to lung base. Computed tomography correctly identified prospectively the site of the adenoma in 10 of 13 patients (77%), with surgically proven adenomas. In retrospect, all 13 adenomas could be identified. One false positive diagnosis of adenoma was made. Our study suggests that CT may be beneficial in the preoperative localization of parathyroid tumors, particularly in ectopic locations.

Successful treatment of adrenal metastases from large-cell carcinoma of the lung

Although on a weight basis the adrenal gland is the most common site of extranodal spread from lung cancer, antemortem diagnosis and successful therapy of adrenal metastasis are rare. We have treated two patients with apparently solitary metastases in the adrenal gland from large-cell carcinomas of the lung using a combination of adrenalectomy and vigorous therapy to the primary site. Both patients experienced symptomatic relief, and, in contrast to the expected short survival in lung cancer with distant metastasis, they remain well six years and 14 years after treatment.

Persistent and recurrent hyperparathyroidism

During the past 11 years at Hammersmith Hospital 11 patients have had parathyroid operations following a previous neck exploration. Six had persistent hyperparathyroidism and 5 had recurrent hyperparathyroidism with a “lucid interval” of biochemical normality of from 5 months to 11 years. Sucessful results were obtained in 9 of the 11 patients after a total of 29 operations, 4 of which were combined with sternotomy. The reasons for failure at operation and the medical and surgical management of these patients are reviewed.