Deregulation and epigenetic modification of BCL2-family genes cause resistance to venetoclax in hematologic malignancies.

The BCL2 inhibitor venetoclax has been approved to treat different hematological malignancies. Because there is no common genetic alteration causing resistance to venetoclax in chronic lymphocytic leukemia (CLL) and B-cell lymphoma, we asked if epigenetic events might be involved in venetoclax resistance. Therefore, we employed whole-exome sequencing, methylated DNA immunoprecipitation sequencing, and genome-wide clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 screening to investigate venetoclax resistance in aggressive lymphoma and high-risk CLL patients. We identified a regulatory CpG island within the PUMA promoter that is methylated upon venetoclax treatment, mediating PUMA downregulation on transcript and protein level. PUMA expression and sensitivity toward venetoclax can be restored by inhibition of methyltransferases. We can demonstrate that loss of PUMA results in metabolic reprogramming with higher oxidative phosphorylation and adenosine triphosphate production, resembling the metabolic phenotype that is seen upon venetoclax resistance. Although PUMA loss is specific for acquired venetoclax resistance but not for acquired MCL1 resistance and is not seen in CLL patients after chemotherapy-resistance, BAX is essential for sensitivity toward both venetoclax and MCL1 inhibition. As we found loss of BAX in Richter's syndrome patients after venetoclax failure, we defined BAX-mediated apoptosis to be critical for drug resistance but not for disease progression of CLL into aggressive diffuse large B-cell lymphoma in vivo. A compound screen revealed TRAIL-mediated apoptosis as a target to overcome BAX deficiency. Furthermore, antibody or CAR T cells eliminated venetoclax resistant lymphoma cells, paving a clinically applicable way to overcome venetoclax resistance.

Osimertinib and anti-HER3 combination therapy engages immune dependent tumor toxicity via STING activation in trans.

Over the past decade, immunotherapy delivered novel treatments for many cancer types. However, lung cancer still leads cancer mortality, and non-small-cell lung carcinoma patients with mutant EGFR cannot benefit from checkpoint inhibitors due to toxicity, relying only on palliative chemotherapy and the third-generation tyrosine kinase inhibitor (TKI) osimertinib. This new drug extends lifespan by 9-months vs. second-generation TKIs, but unfortunately, cancers relapse due to resistance mechanisms and the lack of antitumor immune responses. Here we explored the combination of osimertinib with anti-HER3 monoclonal antibodies and observed that the immune system contributed to eliminate tumor cells in mice and co-culture experiments using bone marrow-derived macrophages and human PBMCs. Osimertinib led to apoptosis of tumors but simultaneously, it triggered inositol-requiring-enzyme (IRE1α)-dependent HER3 upregulation, increased macrophage infiltration, and activated cGAS in cancer cells to produce cGAMP (detected by a lentivirally transduced STING activity biosensor), transactivating STING in macrophages. We sought to target osimertinib-induced HER3 upregulation with monoclonal antibodies, which engaged Fc receptor-dependent tumor elimination by macrophages, and STING agonists enhanced macrophage-mediated tumor elimination further. Thus, by engaging a tumor non-autonomous mechanism involving cGAS-STING and innate immunity, the combination of osimertinib and anti-HER3 antibodies could improve the limited therapeutic and stratification options for advanced stage lung cancer patients with mutant EGFR.

Surgical management of complicated and medically refractory inflammatory bowel disease during pregnancy.

AIM: The medical management of inflammatory bowel disease (IBD) in pregnancy and the puerperium is well defined. Data on surgical management of complicated IBD in this setting are lacking. This study aimed to determine the optimal surgical strategy for medically refractory IBD during pregnancy and the puerperium. METHOD: Three databases were systematically reviewed to identify all published series or case reports of women undergoing surgery for Crohn's disease (CD) or ulcerative colitis (UC) while pregnant or during the puerperium. RESULTS: Thirty-two papers were identified, including 86 patients. Nearly one-fifth (18%) of cases were de novo presentations and intervention was required at all stages of pregnancy. UC refractory to medical treatment and perforated small bowel CD were the commonest indications for surgery. Operations used included colectomy, colectomy with mucous fistula and Turnbull-blowhole colostomy for complicated UC and open or laparoscopic small bowel resection with stoma formation for CD. Surgical intervention during the third trimester universally resulted in the onset of labour. Endoscopic and radiological interventions were rarely employed. In studies after 1980 there was no maternal or foetal mortality but there was an almost 50% preterm delivery rate. CONCLUSION: Surgical management of complicated IBD during pregnancy and the puerperium needs to be tailored to disease severity, the type of complications and foetal status. It should involve gastroenterologists, colorectal surgeons, obstetricians and neonatal specialists in a multidisciplinary manner within a single unit.

Increased sensitivity to platinum drugs of cancer cells with acquired resistance to trabectedin.

BACKGROUND: In order to investigate the mechanisms of acquired resistance to trabectedin, trabectedin-resistant human myxoid liposarcoma (402-91/T) and ovarian carcinoma (A2780/T) cell lines were derived and characterised in vitro and in vivo. METHODS: Resistant cell lines were obtained by repeated exposures to trabectedin. Characterisation was performed by evaluating drug sensitivity, cell cycle perturbations, DNA damage and DNA repair protein expression. In vivo experiments were performed on A2780 and A2780/T xenografts. RESULTS: 402-91/T and A2780/T cells were six-fold resistant to trabectedin compared with parental cells. Resistant cells were found to be hypersensitive to UV light and did not express specific proteins involved in the nucleotide excision repair (NER) pathway: XPF and ERCC1 in 402-91/T and XPG in A2780/T. NER deficiency in trabectedin-resistant cells was associated with the absence of a G2/M arrest induced by trabectedin and with enhanced sensitivity (two-fold) to platinum drugs. In A2780/T, this collateral sensitivity, confirmed in vivo, was associated with an increased formation of DNA interstrand crosslinks. CONCLUSIONS: Our finding that resistance to trabectedin is associated with the loss of NER function, with a consequent increased sensitivity to platinum drugs, provides the rational for sequential use of these drugs in patients who have acquired resistance to trabectedin.

No evidence of transfusion transmission of Adenovirus and Epstein-Barr virus infections in paediatric recipients post-bone marrow transplant.

Adenovirus and Epstein-Barr virus can cause significant morbidity and mortality in paediatric patients post-bone marrow transplant. The source of infection is thought to be either reactivation of latent viruses or primary infection. We have investigated whether transfusion of blood components from viraemic donors could provide a route of primary infection in these patients and sought the prevalence of viraemia in the blood donor population from England. In 32 linked donor/recipient samples and 300 unselected blood donors, we found no evidence to suggest that these infections in paediatric bone marrow transplant recipients had been acquired from transfused blood components.

Fatal herpes simplex virus hepatitis following neoadjuvant chemoradiotherapy and anterior resection for rectal cancer.

We describe the case of a young patient who contracted fatal herpes simplex virus hepatitis following neoadjuvant chemoradiotherapy and anterior resection for rectal cancer. The rarity and non-specific presentation of this treatable disease, which masqueraded as the sequelae of postoperative sepsis, resulted in a diagnosis following death. Features that should prompt inclusion of herpes simplex virus hepatitis in the differential diagnoses are suggested and the case is a reminder of how neoadjuvant therapy may subtly alter a patient's immunocompetency.

Selenium homocholic acid taurocholate scanning, selenium-75-labeled bile acid, a novel method for testing the function of the terminal ileum in small bowel transplant recipients: a pilot study.

INTRODUCTION: The terminal ileum (TI) is important for the active reabsorption of bile salts and is the site of allograft rejection; disruption of enterohepatic circulation (EHC) may give insights to inflammatory and other physiologic processes at the TI. SUBJECTS AND METHODS: Four children aged 5 to 12 years who had received small bowel transplantation (SBTx), 3 recovering from post-transplant lymphoproliferative disease (PTLD) and 1 with acute rejection, were studied. Two of the 4 had stoma reversal. Another child (15 years) with progressive familial intrahepatic cholestasis (PFIC) and pruritus, despite liver transplantation and biliary diversion, was studied. Selenium homocholic acid taurocholate scanning ((75)SeHCAT) capsule was given orally (n = 3) or via introducer during endoscopy (n = 2); a baseline whole-body gamma camera scan was done 4 hours later and on days 1 to 5. RESULTS: The normal 3-day bile salt retention is 30% to 70% of baseline and normal adult biological half-life, t½ is 62 ± 17 hours. The results in children with a stoma were very low (0.1% at 7.6 hours; 5% at 17 hours). The children with reversed stoma had retention and t½ closer to the reference range (18% at 29 hours; 22% at 33 hours). The child with PFIC + biliary diversion had an initial very high gamma emission from the stoma bag suggesting excellent reabsorption of bile salts from his TI, but retention was 0.6% and t½ 9.8 hours, demonstrating efficient biliary diversion. CONCLUSION: These results confirm children with stomas malabsorb bile acids, which can be ameliorated after stoma closure. SeHCAT demonstrated that the biliary diversion was working well and may be helpful in preoperative assessment of abnormal EHC. The role of SeHCAT in SBTx requires further evaluation.

The success of rectus and gracilis muscle flaps in the treatment of chronic pelvic sepsis and persistent perineal sinus: a systematic review.

AIM: Chronic pelvic sepsis is a challenging problem, which may require muscle flaps to fill the pelvic cavity. The aim of this systematic review was to determine the relative success of rectus and gracilis flaps used for this purpose. METHOD: A systematic review was conducted to identify papers that reported the outcome of rectus or gracilis myocutaneous flaps in the treatment of persistent perineal sinuses or chronic pelvic sepsis. Reports of muscle flaps used for reconstruction or treatment of fistula in the absence of chronic sepsis were excluded. A successful outcome was defined as complete perineal healing within 12 months of surgery. RESULTS: The review identified 19 studies reporting the outcome of 73 rectus and 87 gracilis flaps. Their respective success was 84% and 64%. Heterogeneity of the underlying cases did not allow for direct comparison of the flaps. Full healing of the flaps was generally achieved within 3 months. Donor site morbidity was minimal. CONCLUSION: The surgical treatment of chronic pelvic sepsis should be tailored to the individual, but the rectus flap has a reasonable success rate with little morbidity.

Outcomes of asymptomatic anastomotic leaks found on routine postoperative water-soluble enema following anterior resection for cancer.

BACKGROUND: The incidence and consequence of an anastomotic leak associated with low anterior resection for cancer mandates covering stoma in most cases. A water-soluble enema is often performed to assess anastomotic integrity prior to stoma reversal. The functional outcome following reversal in patients with occult radiologically detected leaks is poorly defined. The goal of the present study was to determine the functional outcome in patients with a radiologically detected anastomotic leak who subsequently underwent stoma reversal. METHODS: This case control study used patients with and without radiologically detected occult anastomotic leak having undergone reversal of covering stomata. The study group was matched with controls for age, gender, procedure, tumor stage, and adjuvant/neoadjuvant therapy. Validated fecal incontinence quality of life (FIQL), Cleveland Clinic Fecal Incontinence Score (CCFIS), and the Memorial Sloan-Kettering Cancer Center (MSKCC) Bowel Function Index (BFI) were used. Patient satisfaction, medication use, and ancillary procedures prior to closure were also recorded. RESULTS: Thirteen patients with radiologically detected occult anastomotic leaks and 13 matched controls were identified from a prospectively maintained database. The FIQL, CCFIS, and MSKCC BFI scores were significantly reduced in those with occult leaks. The mean number of radiological and surgical interventions was significantly greater in the patients with occult leaks. Antidiarrheal and bulking agent use, as well as patient satisfaction, were the same for both groups. Only one patient in the occult leak group would not undergo stoma reversal again. CONCLUSIONS: Reversal of a defunctioning ileostomy in the presence of an occult radiological leak can be associated with poorer functional outcomes, but patient satisfaction is undiminished.

Influence of enhanced recovery after surgery pathways and laparoscopic surgery on health-related quality of life.

AIM: This study set out to compare the postoperative health related quality of life (HQoL) of patients undergoing elective open colorectal surgery using a well-established enhanced recovery after surgery (ERAS) pathway with those undergoing laparoscopic surgery without an established an ERAS pathway. METHOD: Using a power calculation, it was estimated that 40 patients would be required in each group. HQoL of the two groups was prospectively assessed using SF-12 (Short Form 12) and EORTC QLQ 30 (European Organisation of Research and Treatment of Cancer, Quality of Life Questionnaire) preoperatively, and at 2 and 6 weeks after discharge. RESULTS: Data were collected from 83 patients, 41 in the laparoscopic group and 42 in the open-ERAS group. There was a significant difference between the median length of stay of the open-ERAS (5 days) and laparoscopic (7 days, P = 0.028) groups. There were no significant differences between the HQoL score of the two groups at any stage. In both groups, the majority of HQoL scores had improved considerably by 6 weeks. CONCLUSION: Laparoscopic and open-ERAS surgery have a similar impact on postoperative HQoL. HQoL tends to improve by the 6-week stage.

Developing a national 'low risk' febrile neutropenia framework for use in children and young people's cancer care.

PURPOSE: A Delphi study was undertaken to develop a framework guidance that would rationalise and standardise the care of children with febrile neutropenia (FNP) across the UK. METHODS: A mailed Delphi survey was undertaken with health professionals working in children's cancer units. The survey employed two rounds of feedback on 22 practice statements drawn from a systematic review of clinical evidence. Consensus was assumed for any statement where 80+ % of respondents indicated that they "agreed" or "strongly agreed". RESULTS: Consensus was reached on 21 of the 22 practice statements in round 1 that were categorised into six areas: definition of fever and neutropenia, initial management and choice of antibiotic, defining low-risk patients, strategy in low-risk patients and alternative approaches. Consensus could not be reached on whether patients needed to be afebrile to be suitable for discharge and the required length of outpatient antibiotic treatment. CONCLUSIONS: A Delphi survey allowed the successful development of a national framework for identification and management of children with FNP. The use of an existing well-functioning professional network was key in this project's success.

Balloon dilatation of benign rectal anastomotic strictures -- a review.

BACKGROUND: The occurrence of anastomotic stricture at the level of the rectum gives rise to three broad therapeutic options, namely major pelvic and abdominal revisional surgery, faecal diversion (stoma), or local revision by transanal approaches (including endoscopic and fluoroscopic). This article updates the current evidence and focuses on the results of the balloon dilatation technique. METHODS: A Medline search was carried out using the search terms (dilatation OR dilatation) AND (stricture OR strictures OR stenosis OR stenotic) AND (rectum OR rectal). In an effort to lessen publication bias, articles included at least 10 patients who were consecutively referred for treatment. RESULTS/CONCLUSION: This review would suggest that probably relatively short strictures have been chosen for balloon dilatation and that the results have had a very low major morbidity (0.45%) and mortality (0%) rate.

Prognostic significance of lymph node ratio in patients undergoing abdominoperineal resection of rectum.

BACKGROUND: Lymph node ratio (LNR) has been shown to be an independent prognostic factor in stage III colorectal cancer. Abdominoperineal resection (APR) of rectum is historically associated with poorer oncological outcomes compared to other colorectal resections, and significance of LNR in this group of patients has not been studied. OBJECTIVE: Our aim was to determine impact of LNR on oncological outcomes in a series of patients with rectal cancers undergoing APR. PATIENTS AND METHODS: A series of patients who had undergone APR and had lymph node metastasis were identified from a prospectively maintained clinical, histopathological and radiological database. LNR was calculated, and Cox regression was used to determine the impact of factors affecting local recurrence, distal metastases and overall survival. RESULTS: Fifty-eight (42 males) patients were identified to have rectal cancer with lymph node involvement. LNR was an independent predictor of distal metastasis and overall survival at cutoff levels of 0.17, 0.41 and 0.69. CONCLUSION: Lymph node ratio is an independent predictor of survival outcomes in patients with stage III tumours undergoing APR. LNR may help improve stratification of this group of patients.

The use of a two-gene sequencing approach to accurately distinguish between the species within the Mycobacterium abscessus complex and Mycobacterium chelonae.

Mycobacterium abscessus [M. abscessus (sensu lato) or M. abscessus complex] comprises three closely related species: M. abscessus (sensu stricto), hereafter referred to as M. abscessus, M. bolletii and M. massiliense. We describe here an accurate and robust method for distinguishing M. chelonae from M. abscessus, M. bolletii and M. massiliense, using polymerase chain reaction (PCR) and the sequencing of house-keeping gene targets (hsp65 and rpoB). Sequencing of the sodA gene is of little additional value in discriminating between species, but M. massiliense can be rapidly identified by amplification of the truncated erm(41) gene without the need for amplicon sequencing. We have applied the method to 81 isolates from 40 patients from two hospitals, the majority of whom were cystic fibrosis (CF) patients. Of these patients, 21 had previously been identified as M. chelonae and 59 as M. abscessus complex using commercial line probe assays. We identified these as 46 M. abscessus isolates, 20 M. massiliense isolates, five M. bolletii isolates and nine M. chelonae isolates and confirmed the one M. fortuitum isolate. This is the first study that has identified the individual members of the M. abscessus complex in a UK cohort of mainly CF patients.

Mechanism of cell death resulting from DNA interstrand cross-linking in mammalian cells.

DNA interstrand cross-links (ICLs) are critical cytotoxic lesions produced by cancer chemotherapeutic agents such as the nitrogen mustards and platinum drugs; however, the exact mechanism of ICL-induced cell death is unclear. Here, we show a novel mechanism of p53-independent apoptotic cell death involving prolonged cell-cycle (G(2)) arrest, ICL repair involving HR, transient mitosis, incomplete cytokinesis, and gross chromosomal abnormalities resulting from ICLs in mammalian cells. This characteristic 'giant' cell death, observed by using time-lapse video microscopy, was reduced in ICL repair ERCC1- and XRCC3-deficient cells. Collectively, the results illustrate the coordination of ICL-induced cellular responses, including cell-cycle arrest, DNA damage repair, and cell death.

Virological investigations in sudden unexpected deaths in infancy (SUDI).

Previous studies have implicated viral infections in the pathogenesis of sudden unexpected death in infancy (SUDI), and routine virological investigations are recommended by current SUDI autopsy protocols. The aim of this study is to determine the role of post-mortem virology in establishing a cause of death. A retrospective review of 546 SUDI autopsies was carried out as part of a larger series of >1,500 consecutive paediatric autopsies performed over a 10-year period, 1996-2005, in a single specialist centre. Virological tests were performed as part of the post-mortem examination in 490 (90%) of the 546 SUDI autopsies, comprising 4,639 individual virological tests, of which 79% were performed on lung tissue samples. Diagnostic methods included immunofluorescence assays (using a routine respiratory virus panel; 98% of cases), cell culture (61%), rapid culture techniques such as the DEAFF test for CMV (55%), PCR (13%), electron microscopy (10%), and others. Virus was identified in only 18 cases (4%), viz. five cases of enterovirus, four of RSV, three of HSV and CMV, and one each of adenovirus, influenza virus and HIV. In seven of the 18 cases the death was classified as due to viral infection, whilst of the remaining 11 cases, death was due to bacterial infection in five, a non-infective cause in one and unexplained in five. Virus was identified in 33% of deaths due to probable viral infections, but also in 6% of SUDI due to bacterial infections, and in 2% of SUDI due to known non-infective causes and unexplained SUDI. When predominantly using immunofluorescence, virus is identified in only a small proportion of SUDI autopsies, resulting in a contribution to the final cause of death in <2% of SUDI post-mortem examinations. Routine post-mortem virological analysis by means of an immunofluorescence respiratory virus panel appears to be of limited benefit in SUDI for the purposes of determining cause of death. Application of a broader panel using more sensitive detection techniques may reveal more viruses, although their contribution to the final cause of death requires further exploration.

The histopathologic and molecular basis for the diagnosis of histiocytic sarcoma and histiocyte-associated lymphoma of mice.

Histiocytic sarcoma (HS) and histiocyte-associated lymphoma (HAL) of mice are difficult to distinguish histologically. Studies of multiple cases initially diagnosed as HS or HAL allowed us to define HS as round, fusiform, or mixed cell types that were F4/80+, Mac-2+, and PAX5-; that lacked markers for other sarcomas; and that had immune receptor genes in germline configuration. Two other subsets had clonal populations of lymphocytes. The first, HAL, featured malignant lymphocytes admixed with large populations of normal-appearing histiocytes. The second appeared to be composites of lymphoma and HS. Several cases suggestive of B myeloid-lineage plasticity were also observed.