The lncRNA HOXA11os regulates mitochondrial function in myeloid cells to maintain intestinal homeostasis

This study reveals a previously uncharacterized mechanism to restrict intestinal inflammation via a regulatory RNA transcribed from a noncoding genomic locus. We identified a novel transcript of the lncRNA HOXA11os specifically expressed in the distal colon that is reduced to undetectable levels in colitis. HOXA11os is localized to mitochondria under basal conditions and interacts with a core subunit of complex 1 of the electron transport chain (ETC) to maintain its activity. Deficiency of HOXA11os in colonic myeloid cells results in complex I deficiency, dysfunctional oxidative phosphorylation (OXPHOS), and the production of mitochondrial reactive oxygen species (mtROS). As a result, HOXA11os-deficient mice develop spontaneous intestinal inflammation and are hypersusceptible to colitis. Collectively, these studies identify a new regulatory axis whereby a lncRNA maintains intestinal homeostasis and restricts inflammation in the colon through the regulation of complex I activity.

Real-world treatment sequencing and survival in previously treated advanced renal cell carcinoma patients receiving nivolumab monotherapy: a UK retrospective cohort study

Background

The CheckMate 025 trial established nivolumab monotherapy as one of the standards of care in previously treated advanced or metastatic renal cell carcinoma (aRCC). However, supporting real-world data is lacking. This study investigated characteristics, treatment sequences and clinical outcomes of patients who received nivolumab monotherapy for previously treated aRCC in the UK.

Methods

This was a retrospective cohort study of aRCC patients treated with nivolumab at second line or later (2L +) at 4 UK oncology centres. Eligible patients commenced nivolumab (index date) between 01 March 2016 and 30 June 2018 (index period). Study data were extracted from medical records using an electronic case report form. Data cut-off (end of follow-up) was 31 May 2019.

Results

In total, 151 patients were included with median follow-up of 15.2 months. Mean age was 66.9 years, male preponderance (72.2%), and mostly Eastern Cooperative Oncology Group performance status grade 0–1 (71.5%). Amongst 112 patients with a known International Metastatic RCC Database Consortium score, distribution between favourable, intermediate, and poor risk categories was 20.5%, 53.6%, and 25.9% respectively.

The majority of patients (n = 109; 72.2%) received nivolumab at 2L, and these patients had a median overall survival (OS) of 23.0 months [95% confidence interval: 17.2, not reached]. All patients who received nivolumab at 2L had received TKIs at 1L. Amongst the 42 patients (27.8%) who received nivolumab in third line or later (3L +) the median OS was 12.4 months [95% CI: 8.8, 23.2]. The most common reasons for nivolumab discontinuation were disease progression (2L: 61.2%; 3L: 68.8%) and adverse events (2L: 34.7%; 3L: 28.1%).

Conclusion

This study provides real-world evidence on the characteristics, treatment sequences, and outcomes of aRCC patients who received 2L + nivolumab monotherapy in the UK. Nivolumab-specific survival outcomes were similar to those achieved in the CheckMate 025 trial.

AB0347 TREATMENT RESPONSE WITH ABATACEPT PLUS METHOTREXATE TREATMENT FOR RHEUMATOID ARTHRITIS: REAL-WORLD EVIDENCE FROM THE UK

Background

A previous real-world study has reported the characteristics, treatment patterns and clinical outcomes of patients with rheumatoid arthritis (RA) who received abatacept in UK clinical practice.1,2 However, many of the eligible population received abatacept monotherapy rather than as indicated. A subgroup analysis of patients treated with abatacept in combination with methotrexate (ABA + MTX) was therefore undertaken to explore the treatment effect in this specific patient population.

Objectives

Present a subgroup analysis describing the clinical outcomes of patients with RA treated with ABA + MTX in UK real-world clinical practice.

Methods

A multi-centre, retrospective observational study was undertaken in patients with RA treated with abatacept at any line of therapy between 1 January 2013 and 31 December 2017, across four UK centres. Data were collected from patient medical records from index date, defined as the date of first bDMARD initiation, to most recent RA clinic visit, death or end of study (31 December 2017). Clinical outcomes (disease activity and response to treatment) were measured using the 28-joint Disease Activity Score based on erythrocyte sedimentation rate (DAS28-ESR) and European League Against Rheumatism (EULAR) response criteria. Patients that received abatacept outside indication (i.e., without concomitant methotrexate) were retrospectively excluded from the analysis dataset. Statistical analyses for the ABA + MTX subgroup were repeated in line with the methodology previously reported.1,2

Results

This subgroup analysis included 133 patients, of 213 patients included in the original study, with RA that received ABA + MTX (mean age 54.6 years, 77.4% female, 7.5 years mean duration of RA at index date). At index date, 64.8% of patients were positive for both anti-citrullinated protein antibodies (ACPA) and rheumatoid factor (RF), where data were available. In total, 77.8% of patients were categorised with high disease activity at index, with mean DAS28-ESR of 6.2 (SD 1.1).

Irrespective of line of treatment (LOT), patients tended to have a more favourable distribution of good/moderate/no EULAR response when receiving ABA + MTX (31.8%/34.1%/34.1%; n=44) compared with receipt of other bDMARDs (12.7%/36.4%/50.9%; n=55) at 6 months. Similarly, a favourable distribution of good/moderate/no EULAR response in favour of those receiving ABA + MTX compared with other bDMARDs was observed at 12 months (30.6%/41.7%/27.8% versus 20.0%/35.0%/45.0%, respectively).

Patients receiving ABA + MTX remained on treatment for significantly longer than patients in receipt of other bDMARDs as first LOT (median time on treatment 53.4 vs 18.1 months; p<0.01). A similar trend was observed at second LOT, although differences were not statistically significant (median time on treatment 40.1 vs 19.7 months; p =0.08).

Conclusion

Patients with RA who received treatment with any bDMARDs, including ABA + MTX, experienced reduced disease activity. However, those receiving ABA + MTX persisted with treatment significantly longer than when receiving other bDMARDs.

References

[1]Choy, E. et al. Outcomes in rheumatoid arthritis patients treated with abatacept: a UK multi-centre observational study. BMC Rheumatology5, 3, doi:10.1186/s41927-020-00173-0 (2021).

[2]Henning, S. et al. AB0295 CHANGE IN DISEASE ACTIVITY AND TREATMENT RESPONSE AFTER ABATACEPT TREATMENT FOR RHEUMATOID ARTHRITIS: REAL-WORLD EVIDENCE FROM THE UK. Annals of the Rheumatic Diseases79, 1446-1447, doi:10.1136/annrheumdis-2020-eular.1069 (2020).

Acknowledgements

This analysis was supported by Bristol-Myers Squibb.

Disclosure of Interests

Ernest Choy Speakers bureau: Abbvie, Amgen, Bristol Myer Squibbs, Chugai Pharma, Eli Lilly, Galapagos, Gilead, Janssen, Novartis, Pfizer, Regeneron, Roche, Sanofi, and UCB, Consultant of: Abbvie, Amgen, Biogen, Biocon, Chugai Pharma, Eli Lilly, Gilead, Janssen, Merck Serono, Novartis, Pfizer, Regeneron, Roche, R-Pharm and Sanofi, Grant/research support from: Bio-Cancer, Biogen, Novartis, Pfizer, Roche, Sanofi and UCB, Sadie Henning Shareholder of: Bristol Myers Squibb, Employee of: Yes, Bristol Myers Squibb, Marie Brazil Shareholder of: Bristol Myers Squibb, Employee of: Currently an employee of Bristol Myers Squibb, Kevin Pollock Shareholder of: Yes - Bristol Myers Squibb, Speakers bureau: Yes - Merck Sharp & Dohme and Glaxo Smith Kline, Consultant of: Yes - Merck Sharp & Dohme, Employee of: Yes – currently employed by Bristol Myers Squibb, Lara Groves Grant/research support from: I am an employee of Health Economics and Outcomes Research Ltd., Cardiff, UK, who received fees from Bristol Myers Squibb in relation to this study, Daniel Sugrue Grant/research support from: I am an employee of Health Economics and Outcomes Research Ltd., Cardiff, UK, who received fees from Bristol Myers Squibb in relation to this study, John Houghton Grant/research support from: I am an employee of Health Economics and Outcomes Research Ltd., Cardiff, UK, who received fees from Bristol Myers Squibb in relation to this study

Dysbiosis exacerbates colitis by promoting ubiquitination and accumulation of the innate immune adaptor STING in myeloid cells

Alterations in the cGAS-STING DNA-sensing pathway affect intestinal homeostasis. We sought to delineate the functional role of STING in intestinal inflammation. Increased STING expression was a feature of intestinal inflammation in mice with colitis and in humans afflicted with inflammatory bowel disease. Mice bearing an allele rendering STING constitutively active exhibited spontaneous colitis and dysbiosis, as well as progressive chronic intestinal inflammation and fibrosis. Bone marrow chimera experiments revealed STING accumulation in intestinal macrophages and monocytes as the initial driver of inflammation. Depletion of Gram-negative bacteria prevented STING accumulation in these cells and alleviated intestinal inflammation. STING accumulation occurred at the protein rather than transcript level, suggesting post-translational stabilization. We found that STING was ubiquitinated in myeloid cells, and this K63-linked ubiquitination could be elicited by bacterial products, including cyclic di-GMP. Our findings suggest a positive feedback loop wherein dysbiosis foments the accumulation of STING in intestinal myeloid cells, driving intestinal inflammation.

HIV-1-induced cytokines deplete homeostatic innate lymphoid cells and expand TCF7-dependent memory NK cells

Human immunodeficiency virus 1 (HIV-1) infection is associated with heightened inflammation and excess risk of cardiovascular disease, cancer and other complications. These pathologies persist despite antiretroviral therapy. In two independent cohorts, we found that innate lymphoid cells (ILCs) were depleted in the blood and gut of people with HIV-1, even with effective antiretroviral therapy. ILC depletion was associated with neutrophil infiltration of the gut lamina propria, type 1 interferon activation, increased microbial translocation and natural killer (NK) cell skewing towards an inflammatory state, with chromatin structure and phenotype typical of WNT transcription factor TCF7-dependent memory T cells. Cytokines that are elevated during acute HIV-1 infection reproduced the ILC and NK cell abnormalities ex vivo. These results show that inflammatory cytokines associated with HIV-1 infection irreversibly disrupt ILCs. This results in loss of gut epithelial integrity, microbial translocation and memory NK cells with heightened inflammatory potential, and explains the chronic inflammation in people with HIV-1.

100 Prevalence of Cognitive Impairment in Vascular Surgery Patients: Preliminary Results of A Systematic Review and Meta-Analysis

Introduction

Single-centre studies have shown a high prevalence of undiagnosed cognitive impairment in patients undergoing vascular surgery. The aim of this meta-analysis was to estimate the pooled prevalence of cognitive impairment in vascular surgery patients.

Methods

A systematic review and meta-analysis was performed of studies reporting cognitive impairment in vascular surgery patients (PROSPERO registration: CRD42019134684). Databases searched included: Medline, Embase, Emcare, CINAHL, PsychINFO and Scopus. Studies were excluded if they: did not use a validated cognitive assessment tool, included patients with asymptomatic or sub-threshold (for treatment) disease, or excluded patients with cognitive impairment. Quality of included studies was assessed using Newcastle-Ottawa scores (NOS), risk of bias was assessed using the ROBINS-E tool, and quality of evidence assessed using GRADE criteria. A pooled estimate of prevalence was calculated using the inverse-variance method separately for carotid artery disease (CAD), lower extremity arterial disease (LEAD), and studies including patients with multiple vascular surgery presentations. Data were pooled using random effects models and estimated prevalence presented with 95% confidence intervals (95%CI). Subgroup analyses were performed by cognitive assessment tool used.

Authors of 24 studies meeting inclusion criteria that did not report numbers of cognitively impaired patients were contacted to enable inclusion: responses are awaited.

Results

After de-duplication of search results, 7,169 records were screened and 11 studies (911 patients) included in the meta-analysis. Nine studies were deemed high quality (NOS ≥7) however 8 studies had a serious risk of bias. Only one study explicitly stated provision for recruiting patients without capacity. Six different tools were used to assess cognitive function (MoCA, MMSE, ACE-R, HDS-R, Mini-Cog and a global cognitive score). Two studies found an association of cognitive impairment with post-op delirium whilst one did not, and a further study showed an association with increased length of stay.

Pooled estimate of prevalence of cognitive impairment in CAD patients was 38% (95%CI 17%, 62%; 7 studies), and in “vascular surgery patients” was 61% (95%CI 47%, 74%, 3 studies). Only one study reported prevalence of cognitive impairment in LEAD patients alone of 19% (95%CI 14%, 24%). Quality of evidence was moderate to very low.

Conclusions

Cognitive impairment is highly prevalent in vascular surgery patients highlighting the need for close collaboration between vascular surgeons and geriatricians.

Initiation of inflammatory tumorigenesis by CTLA4 insufficiency due to type 2 cytokines

CTLA4 insufficiency is genetically associated with stomach cancer. Miska et al. demonstrate that CTLA4 insufficiency causes stomach cancer by autoimmune inflammation, an effect largely attributed to type 2 cytokine stimulation of stomach mucosal cells. These findings suggest preventive strategies against tumor initiation by controlling type 2 inflammation while preserving type 1 immunity.

Genetically predisposed CTLA4 insufficiency in humans is associated with gastric cancer development, which is paradoxical to the prototypical role of CTLA4 in suppressing antitumor immunity. CTLA4 is a critical immune checkpoint against autoimmune disorders. Autoimmunity has been implicated in protumor or antitumor activities. Here, we show that CTLA4 insufficiency initiates de novo tumorigenesis in the mouse stomach through inflammation triggered by host-intrinsic immune dysregulation rather than microbiota, with age-associated progression to malignancy accompanied by epigenetic dysregulation. The inflammatory tumorigenesis required CD4 T cells, but not the T_H1 or T_H17 subsets. Deficiencies in IL-4 and IL-13 or IL-4 receptor α broke the link between inflammation and initiation of tumorigenesis. This study establishes the causality of CTLA4 insufficiency in gastric cancer and uncovers a role of type 2 inflammation in initiating gastric epithelial transformation. These findings suggest possible improvement of immune therapies by blocking tumorigenic type 2 inflammation while preserving antitumor type 1 immunity.

Does sensory relearning improve tactile function after carpal tunnel decompression? A pragmatic, assessor-blinded, randomized clinical trial

Despite surgery for carpal tunnel syndrome being effective in 80%-90% of cases, chronic numbness and hand disability can occur. The aim of this study was to investigate whether sensory relearning improves tactile discrimination and hand function after decompression. In a multi-centre, pragmatic, randomized, controlled trial, 104 patients were randomized to a sensory relearning ( n = 52) or control ( n = 52) group. A total of 93 patients completed a 12-week follow-up. Primary outcome was the shape-texture identification test at 6 weeks. Secondary outcomes were touch threshold, touch localization, dexterity and self-reported hand function. No significant group differences were seen for the primary outcome (Shape-Texture Identification) at 6 weeks or 12 weeks. Similarly, no significant group differences were observed on secondary outcomes, with the exception of self-reported hand function. A secondary complier-averaged-causal-effects analysis showed no statistically significant treatment effect on the primary outcome. Sensory relearning for tactile sensory and functional deficits after carpal tunnel decompression is not effective.

LEVEL OF EVIDENCE

II.

Spatial variability in photosynthetic and heterotrophic activity drives localized δ13C org fluctuations and carbonate precipitation in hypersaline microbial mats

Modern laminated photosynthetic microbial mats are ideal environments to study how microbial activity creates and modifies carbon and sulfur isotopic signatures prior to lithification. Laminated microbial mats from a hypersaline lagoon (Guerrero Negro, Baja California, Mexico) maintained in a flume in a greenhouse at NASA Ames Research Center were sampled for δ(13) C of organic material and carbonate to assess the impact of carbon fixation (e.g., photosynthesis) and decomposition (e.g., bacterial respiration) on δ(13) C signatures. In the photic zone, the δ(13) C org signature records a complex relationship between the activities of cyanobacteria under variable conditions of CO2 limitation with a significant contribution from green sulfur bacteria using the reductive TCA cycle for carbon fixation. Carbonate is present in some layers of the mat, associated with high concentrations of bacteriochlorophyll e (characteristic of green sulfur bacteria) and exhibits δ(13) C signatures similar to DIC in the overlying water column (-2.0‰), with small but variable decreases consistent with localized heterotrophic activity from sulfate-reducing bacteria (SRB). Model results indicate respiration rates in the upper 12 mm of the mat alter in situ pH and HCO3- concentrations to create both phototrophic CO2 limitation and carbonate supersaturation, leading to local precipitation of carbonate minerals. The measured activity of SRB with depth suggests they variably contribute to decomposition in the mat dependent on organic substrate concentrations. Millimeter-scale variability in the δ(13) C org signature beneath the photic zone in the mat is a result of shifting dominance between cyanobacteria and green sulfur bacteria with the aggregate signature overprinted by heterotrophic reworking by SRB and methanogens. These observations highlight the impact of sedimentary microbial processes on δ(13) C org signatures; these processes need to be considered when attempting to relate observed isotopic signatures in ancient sedimentary strata to conditions in the overlying water column at the time of deposition and associated inferences about carbon cycling.

Mesenchymal stem cells induce epithelial proliferation within the inflamed stomach

Bone marrow-derived mesenchymal stem cells (MSCs) sustain cancer cells by creating a microenvironment favorable for tumor growth. In particular, MSCs have been implicated in gastric cancer development. There is extensive evidence suggesting that Hedgehog signaling regulates tumor growth. However, very little is known regarding the precise roles of Hedgehog signaling and MSCs in tumor development within the stomach. The current study tests that hypothesis that Sonic Hedgehog (Shh), secreted from MSCs, provides a proliferative stimulus for the gastric epithelium in the presence of inflammation. Red fluorescent protein-expressing MSCs transformed in vitro (stMSCs) were transduced with lentiviral constructs containing a vector control (stMSC(vect)) or short hairpin RNA (shRNA) targeting the Shh gene (stMSC(ShhKO)). Gastric submucosal transplantation of wild-type MSCs (wtMSCs), wild-type MSCs overexpressing Shh (wtMSC(Shh)), stMSC(vect), or stMSC(ShhKO) cells in C57BL/6 control (BL/6) or gastrin-deficient (GKO) mice was performed and mice analyzed 30 and 60 days posttransplantation. Compared with BL/6 mice transplanted with wtMSC(Shh) and stMSC(vect) cells, inflamed GKO mice developed aggressive gastric tumors. Tumor development was not observed in mouse stomachs transplanted with wtMSC or stMSC(ShhKO) cells. Compared with stMSC(ShhKO)-transplanted mice, within the inflamed GKO mouse stomach, Shh-expressing stMSC(vect)- and wtMSC(Shh)-induced proliferation of CD44-positive cells. CD44-positive cells clustered in gland-like structures within the tumor stroma and were positive for Patched (Ptch) expression. We conclude that Shh, secreted from MSCs, provides a proliferative stimulus for the gastric epithelium that is associated with tumor development, a response that is sustained by chronic inflammation.

NOD-scidIl2rg (tm1Wjl) and NOD-Rag1 (null) Il2rg (tm1Wjl) : a model for stromal cell-tumor cell interaction for human colon cancer

BACKGROUND/AIMS

Stromal cells and the extracellular environment are vital to human tumors, influencing growth and response to therapy. Human tumor cell lines lack stroma and transplantation into immunodeficient mice does not allow meaningful analyses of the effects of stroma on tumor cell growth. Studies of xenografts of primary human tumor fragments in nude mice and in early scid mouse models were constrained by poor tumor growth accompanied by host-versus-graft reactivity, dramatically altering tumor architecture and tumor microenvironment. In contrast, severely immunodeficient NOD-scid and NOD-Rag1 (null) strains carrying the IL2rg (null) mutation (NSG and NRG) support the growth of many types of human primary tumors.

METHODS/RESULTS

We compared the take rate, growth and architectural preservation of 10 clinically distinct primary human colon cancers in NOD-scid, NOD-Rag1 (null) , NSG and NRG mice and determined the contribution of mouse and human cells to the stroma during tumor proliferation and expansion in secondary hosts and tumor response to treatment with 5-fluorouracil (5-FU). NSG and NRG mice more readily support growth of human primary colon tumor fragments than do NOD-scid, NOD-Rag1 (null) mice and maintain tumor architectural integrity in the primary recipient and through subsequent transplant generations. The human colon tumors were responsive to treatment with 5-FU. Human stromal cells in the primary graft were replaced by mouse-derived fibroblasts in a dynamic process during subsequent passages.

CONCLUSION

Human colon cancer xenografts propagated in NSG and NRG mice maintain structural fidelity while replacing human stromal cells with murine stromal cells.

Sonic hedgehog mediates the proliferation and recruitment of transformed mesenchymal stem cells to the stomach

Studies using Helicobacter-infected mice show that bone marrow-derived mesenchymal stem cells (MSCs) can repopulate the gastric epithelium and promote gastric cancer progression. Within the tumor microenvironment of the stomach, pro-inflammatory cytokine interferon-gamma (IFNγ) and Sonic hedgehog (Shh) are elevated. IFNγ is implicated in tumor proliferation via activation of the Shh signaling pathway in various tissues but whether a similar mechanism exists in the stomach is unknown. We tested the hypothesis that IFNγ drives MSC proliferation and recruitment, a response mediated by Shh signaling. The current study uses transplantation of an in vitro transformed mesenchymal stem cell line (stMSC^vect), that over-expresses hedgehog signaling, in comparison to non-transformed wild-type MSCs (wtMSCs), wtMSCs transfected to over-express Shh (wtMSC^Shh), and stMSCs transduced with lentiviral constructs containing shRNA targeting the Shh gene (stMSC^ShhKO). The effect of IFNγ on MSC proliferation was assessed by cell cycle analysis in vitro using cells treated with recombinant IFNγ (rmIFNγ) alone, or in combination with anti-Shh 5E1 antibody, and in vivo using mice transplanted with MSCs treated with PBS or rmIFNγ. In vitro, IFNγ significantly increased MSC proliferation, a response mediated by Shh that was blocked by 5E1 antibody. The MSC population collected from bone marrow of PBS- or IFNγ-treated mice showed that IFNγ significantly increased the percentage of all MSC cell lines in S phase, with the exception of the stMSCs^ShhKO cells. While the MSC cell lines with intact Shh expression were recruited to the gastric mucosa in response to IFNγ, stMSCs^ShhKO were not. Hedgehog signaling is required for MSC proliferation and recruitment to the stomach in response to IFNγ.

Abstract LB-285: Regulation of therapy resistance in slow-cycling cancer cells

Tumor recurrence after chemotherapy is a major cause of patient morbidity and mortality. Recurrences are thought to be due in part to small subsets of cancer cells that are better able to survive traditional forms of chemotherapy and thus drive tumor re-growth. The ability to isolate and better characterize these therapy-resistant cells is critical for the future development of targeted therapies aimed at achieving more robust and long-lasting responses. Slow-cycling stem cells are integral components of adult epithelial tissues and are required for tissue maintenance. These slow-cycling cells are inherently resistant to traditional forms of chemotherapy that primarily target actively cycling cells. Using a novel application for the proliferation marker CFSE, we have identified populations of slow-cycling, label-retaining cells (LRCs) in primary tumors and cancer cell lines. As predicted, quiescent LRCs exhibit a multi-fold increase in chemoresistance but retain the ability to re-enter the cell cycle. We further demonstrate the innovative application of CFSE to live sort slow-cycling tumor cells and begin to explore the mechanisms behind LRC resistance and survival. Using RT-PCR and immunoblotting, we have observed consistent over-expression of the CDK5 activator, p35, in LRCs of both primary tumor xenografts and in-vitro sphere cultures. While p35 is known to play an active role in neurogenesis, cell migration, and apoptosis within the developing brain, its role in tumor biology remains unclear. Manipulation of p35 expression affects cell cycle distribution, extent of the LRC pool, and cell survival when challenged with traditional forms of chemotherapy. Additionally, we demonstrate that alterations in p35 expression alters downstream CDK5 signaling and the activation state of BCL2. Combined, our data suggest a model whereby the CDK5/p35 complex acts to slow cell cycling speed and change expression of BCL2, promoting resistance to chemotherapy. Future p35 targeting, in combination with traditional forms of chemotherapy, may help to reduce recurrence rates and increase long-term patient survival.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-285. doi:1538-7445.AM2012-LB-285

Slow-cycling therapy-resistant cancer cells

Tumor recurrence after chemotherapy is a major cause of patient morbidity and mortality. Recurrences are thought to be secondary to small subsets of cancer cells that are better able to survive traditional forms of chemotherapy and thus drive tumor regrowth. The ability to isolate and better characterize these therapy-resistant cells is critical for the future development of targeted therapies aimed at achieving more robust and long-lasting responses. Using a novel application for the proliferation marker carboxyfluorescein diacetate, succinimidyl ester (CFSE), we have identified a population of slow-cycling, label-retaining tumor cells in both in vitro sphere cultures and in vivo xenograft models. Strikingly, label-retaining cells exhibit a multifold increase in ability to survive traditional forms of chemotherapy and reenter the cell cycle. Further, we demonstrate the innovative application of CFSE to live sort slow-cycling tumor cells and validate their chemoresistance and tumorigenic potential.

A multiplex technology platform for the rapid detection of relevant mutations in the EGFR signaling pathway

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Background: Determination of the mutational status of key gene effectors along the EGFR signaling pathway plays a critical role in the management of metastatic colorectal cancer (mCRC) and other cancer types. We previously reported the rapid, multiplex, and sensitive detection of 7 common KRAS mutations in mCRC FFPE specimens using the Signature KRAS Mutations (RUO) kit. We show here that the same technology platform can be applied to the detection of additional clinically relevant mutations in the EGFR, BRAF, KRAS, NRAS and HRAS genes.

Methods: Mutation panels were designed for multiplex PCR amplification of an internal control gene and discrete mutation regions in independent target genes. PCR products were hybridized on a liquid bead array carrying target-specific probes and sorted by flow cytometry using a Luminex 200 system. Genomic DNA was extracted from cell lines and representative flash frozen, FFPE or FNA clinical specimens using laboratory-validated extraction methods.

Results: Using model plasmids and cell lines we developed specific assays for distinct mutations in KRAS codon 12/13, KRAS 3' UTR (rs61764370), BRAF codon 600/601, HRAS codon 12/61, NRAS codon 61, and EGFR exon 19/20/21. The various assays reached 0.1 to 5% analytical sensitivity and could be further combined in multiplex panels relevant to specific applications. The Signature KRAS/BRAF Mutations (RUO) kit, an assay for 12 KRAS mutations in codon 12/13 and BRAF V600E, was validated in over 250 mCRC FFPE specimens with >99% agreement with clinically validated methods. Specific detection of these 13 mutations and 6 HRAS/NRAS mutations was also demonstrated in thyroid nodule FNA specimens. Single-well detection of EGFR deletions in exon 19 together with the point mutations L858R and T790M was also successfully evaluated in lung specimens.

Conclusions: The Signature technology platform is a specific, sensitive and flexible tool for the assessment of various mutations in different tissue types. The development and validation of broader mutation panels would likely facilitate the rapid molecular characterization of individual tumor specimens and the optimization of personalized treatments for mCRC and other cancer types.

[Table: see text]

Mutations in bone marrow-derived stromal stem cells unmask latent malignancy

Neoplastic epithelia may remain dormant and clinically unapparent in human patients for decades. Multiple risk factors including mutations in tumor cells or the stromal cells may affect the switch from dormancy to malignancy. Gene mutations, including p53 mutations, within the stroma of tumors are associated with a worse clinical prognosis; however, it is not known if these stromal mutations can promote tumors in genetically at-risk tissue. To address this question, Apc(Min/+) and Apc(Min/+) Rag2(-/-) mice, which have a predilection to mammary carcinoma (as well as wild-type (wt) mice), received mesenchymal stem cells (MSC) with mutant p53 (p53MSC) transferred via tail vein injection. In the wt mouse, p53MSC circulated in the periphery and homed to the marrow cavity where they could be recovered up to a year later without apparent effect on the health of the mouse. No mammary tumors were found. However, in mice carrying the Apc(Min/+) mutation, p53MSC homed to mammary tissue and significantly increased the incidence of mammary carcinoma. Tumor necrosis factor (TNF)-alpha-dependent factors elaborated from mesenchymal cells converted quiescent epithelia into clinically apparent disease. The increased cancer phenotype was completely preventable with neutralization of TNF-alpha or by transfer of CD4(+) regulatory T cells from immune competent donors, demonstrating that immune competency to regulate inflammation was sufficient to maintain neoplastic dormancy even in the presence of oncogenic epithelial and stromal mutations. The significant synergy between host immunity and mesenchymal cells identified here may restructure treatments to restore an anticancer microenvironment.

Human Barrett's adenocarcinoma of the esophagus, associated myofibroblasts, and endothelium can arise from bone marrow-derived cells after allogeneic stem cell transplant

This study characterizes the contribution of bone marrow-derived cells (BMDCs) to Barrett's adenocarcinoma of the esophagus using a mouse surgical model of disease and human specimens. Transplantation of bone marrow expressing beta galactosidase into a wild-type mouse, followed by surgical esophagojejunostomy, allowed tracking of BMDCs into the surgical anastomosis and resulting Barrett's metaplasia. Human tissue from a male patient who had been transplanted with female bone marrow and later developed esophageal adenocarcinoma allowed us to tract donor-derived cells into the tumor. Using a combination of antibodies directed against beta-galactosidase (animal studies) and X/Y fluorescent in situ hybridization (FISH) (human studies), combined with specific lineage staining directed against epithelial, fibroblast, endothelial, and leukocyte markers, we show that bone marrow cells contribute to both the epithelial and stromal component of esophageal adenocarcinoma. These findings demonstrate that BMDCs can generate cancer-associated fibroblasts as well as contribute directly to epithelial cells in cancer of the esophagus.

Rituximab based therapy followed by autologous stem cell transplantation leads to superior outcome and high rates of PCR negativity in patients with indolent B-cell lymphoproliferative disorders

Autologous stem cell transplantation (ASCT) and rituximab based therapy represent effective treatments of indolent B-cell lymphoproliferative disorders (B-LPDs) that often induce molecular remission (MR). We assessed the impact of MR after treatment on prognosis of 57 patients with indolent B-LPDs. We also evaluated the impact of therapy on patients' outcome. Failure to achieve MR was identified as an independent risk factor regardless of treatment modality. PCR positive patients had shorter progression free survival (PFS) in contrast with patients in MR after rituximab (median 0.75 and 2.5 years respectively; p=0.006) or patients in MR after rituximab followed by ASCT (median 3.3 years; p=0.0032). PCR positive patients had a 5-year overall survival (OS) of only 40% compared to a 5-year OS of 76% for PCR negative patients after rituximab (p=0.0186) and 86% PCR negative patients after rituximab with ASCT (p=0.003). All nine patients transplanted with PCR positive graft relapsed (p=0.0023) with shorter PFS (p=0.0008). Rituximab based therapy induced MR in 25 (64%) compared to 18 (100%) patients after rituximab followed by ASCT (p=0.0025). We observed no difference in PFS between the transplant group (3.3 years) and rituximab based treatment (1.9 years), but the 5-year OS of patients with transplant was 85 and 59% respectively (p=0.0271). Patients with indolent B-LPDs who achieve MR have better prognosis. Rituximab based therapy induces MR in high number of patients, which can be further improved by ASCT and patients have an excellent outcome. PCR positive harvest represents a high risk of relapse after ASCT.

Human and mouse colon cancer utilizes CD95 signaling for local growth and metastatic spread to liver

BACKGROUND & AIMS

Analysis of clinical colon cancer specimens show alterations in the CD95 (Fas Ag/Fas L) pathway as tumors progress from local to metastatic disease, suggesting that this pathway may play a role in invasive behavior of colon cancer. However, direct causality between these alterations and clinical disease progression has not been shown.

METHODS

Surgically resected metastatic colon cancer samples were evaluated for Fas Ag/L and apoptosis. Alterations in the Fas-signaling pathway found in human samples were recreated through a series of staged transfection experiments in the MC38 mouse colon cancer cell line and the effects on growth tested in vitro and in vivo.

RESULTS

Expression of FLICE-like inhibitory protein confers apoptosis resistance, increasing the incidence of primary tumors through a survival advantage by avoiding apoptosis and inducing Fas-mediated proliferation. Coexpression of Fas L enables colon cancer cells to metastasize to the liver from local tumors as well as from intravenous injection of cells. MC38-FasL/FLICE-like inhibitory protein colon cancer cells induce apoptosis in hepatocytes via activation of type II Fas Ag signaling, thus creating a niche conducive to tumor growth and fueling their own growth via Fas proliferative signaling.

CONCLUSIONS

Alterations in the Fas Ag pathway which inhibit apoptosis and increase Fas-mediated proliferation directly increase local colon cancer growth, and enhance metastasis to the liver. Delineating points in the pathway responsible for growth and metastasis will offer targets that may be exploited for therapy.

T-bet knockout prevents Helicobacter felis-induced gastric cancer

Helicobacter infection is the primary risk factor for gastric cancer, with the cytokine environment within the gastric mucosa the strongest predictor of disease risk. Elevated TNF-alpha, IL-1beta, and low IL-10 are associated with the highest risk. In this study, we used C57BL/6 mice to identify T-bet as a central regulator of the cytokine environment during Helicobacter felis infection. We infected male and female C57BL/6 and C57BL/6-T-bet knockout (KO) litter mates with H. felis and examined the bacterial colonization, immune response, and mucosal damage at varying time points. T-bet KO mice maintained infection for 15 mo at similar levels to wild-type mice. Infection and immune response did not differ between male and female mice. Despite sustained infection, T-bet KO mice respond with a blunted Th1 response associated with preservation of parietal and chief cells and protection from the development of gastric cancer. Unexpectedly, T-bet KO mice develop a gastric environment that would not be expected based on the phenotype of T-bet KO CD4 cells alone. T-bet KO mice respond to H. felis infection with a markedly blunted IL-1beta and TNF-alpha and elevated IL-10 levels. Activity of this one master regulator modulates the expression of the key gastric mucosal cytokines associated with gastric cancer and may be a target for therapy to restore immune balance clinically in patients at risk for gastric cancer.

Helicobacter-based mouse models of digestive system carcinogenesis

Animal models are necessary to reproduce the complex host, microbial and environmental influences associated with infectious carcinogenesis of the digestive system. Today, mouse models are preferred by most researchers because of cost efficiencies, rapid reproduction, choice of laboratory reagents, and availability of genetically engineered mutants to study specific gene functions in vivo. Mouse models have validated the once-provocative hypothesis that Helicobacter pylori infection is a major risk factor for gastric carcinoma, dispelling early skepticism over the pathogenic nature of this organism in the human stomach. Enterohepatic Helicobacter spp. induce inflammatory bowel disease and colorectal carcinoma in susceptible mouse strains, permitting study of host immunity and microbial factors at the cellular and molecular level. H. hepaticus is the only proven infectious hepatocarcinogen of mice and has been used to explore mechanisms of inflammation-associated liver cancer as seen in human chronic viral hepatitis. For example, this model was used to identify for the first time a potential mechanism for male-predominant liver cancer risk independent of circulating sex hormones. Helicobacter-based mouse models of digestive system carcino-genesis are used to investigate the basic biology of inflammation-associated human cancers and to evaluate therapeutic interventions at the discovery level. Because of exciting advances in genetic engineering of mice, in vivo imaging, and system-wide genomics and proteomics, these models will provide even more information in the future. This chapter introduces the mouse as a model species; summarizes important models of inflammation-associated cancer incited by murine Helicobacter infection; and describes methods for the collection, sampling, and histologic grading of mouse digestive system tissues.

Green tea inhibits Helicobacter growth in vivo and in vitro

Helicobacter infection, one of the most common bacterial infections in man worldwide, is a type 1 carcinogen and the most important risk factor for gastric cancer. Helicobacter pylori bacterial factors, components of the host genetics and immune response, dietary cofactors and decreased acid secretion resulting in bacterial overgrowth are all considered important factors for induction of gastric cancer. Components found in green tea have been shown to inhibit bacterial growth, including the growth of Helicobacter spp. In this study, we assessed the bactericidal and/or bacteriostatic effect of green tea against Helicobacter felis and H. pylori in vitro and evaluated the effects of green tea on the development of Helicobacter-induced gastritis in an animal model. Our data clearly demonstrate profound growth effects of green tea against Helicobacter and, importantly, demonstrate that green tea consumption can prevent gastric mucosal inflammation if ingested prior to exposure to Helicobacter infection. Research in the area of natural food compounds and their effects on various disease states has gained increased acceptance in the past several years. Components within natural remedies such as green tea could be further used for prevention and treatment of Helicobacter-induced gastritis in humans.

A EuroPrevall review of factors affecting incidence of peanut allergy: priorities for research and policy

Peanuts are extensively cultivated around the world, providing a foodstuff that is both cheap to produce and nutritious. However, allergy to peanuts is of growing global concern, particularly given the severity of peanut-allergic reactions, which can include anaphylaxis and death. Consequently, it is important to understand the factors related to the prevalence of peanut allergy in order to inform efforts to ameliorate or pre-empt the condition. In this article we review evidence for the relevance of factors hypothesized to have some association with allergy prevalence, including both genetic and environmental factors. Although our analysis does indicate some empirical support for the importance of a number of factors, the key finding is that there are significant data gaps in the literature that undermine our ability to provide firm conclusions. We highlight these gaps, indicating questions that need to be addressed by future research.

The high prevalence of unrecognized anaemia in patients with diabetes and chronic kidney disease: a population-based study

BACKGROUND

Anaemia occurs early in the course of diabetes-related chronic kidney disease (CKD). There is little evidence about the prevalence of anaemia in people with diabetes. The aim of this study was to assess the prevalence of anaemia, by stage of CKD, in the general diabetic population.

METHODS

Haemoglobin (Hb) was measured on all glycated haemoglobin (HbA1c) samples and the most recent (< 4 months) estimated glomerular filtration rate (eGFR) was obtained. Anaemia (at treatment level) was defined as Hb < 110 g/l or the use of erythropoetic stimulating agents (ESA).

RESULTS

Twelve per cent (10-14%) of people had Hb < 110 g/l. The prevalence of anaemia increased progressively with worsening CKD. People with CKD stage 3 accounted for the largest number of people with anaemia; 18% (95% CI 13-24%) had Hb < 110 g/l. Those with eGFR < 60 ml/min/1.73 m2 and not on ESA or dialysis were four (2-7) times more likely than patients with better renal function to have Hb < 110 g/l. The relation between Hb and eGFR became approximately linear below an eGFR of 83 ml/min/1.73 m2, where, for every 1 ml/min/1.73 m2 fall in eGFR, there was a 0.4 (0.3-0.5) g/l fall in haemoglobin.

CONCLUSIONS

This study demonstrates that anaemia, at levels where treatment is indicated, occurs commonly in people with diabetes and CKD stage 3 or worse. The screening for anaemia in current diabetes management should be extended.

Spontaneous expression of embryonic factors and p53 point mutations in aged mesenchymal stem cells: a model of age-related tumorigenesis in mice

Aging is the single most common risk factor for cancer. Peripheral and marrow-derived stem cells are long lived and are candidate cells for the cancer-initiating cell. Repeated rounds of replication are likely required for accumulation of the necessary genetic mutations. Based on the facts that mesenchymal stem cells (MSC) transform with higher frequency than other cell types, and tumors in aged C57BL/6 mice are frequently fibrosarcomas, we used a genetically tagged bone marrow (BM) transplant model to show that aged mice develop MSC-derived fibrosarcomas. We further show that, with aging, MSCs spontaneously transform in culture and, when placed into our mouse model, recapitulated the naturally occurring fibrosarcomas of the aged mice with gene expression changes and p53 mutation similar to the in vivo model. Spontaneously transformed MSCs contribute directly to the tumor, tumor vasculature, and tumor adipose tissue, recruit additional host BM-derived cells (BMDC) to the area, and fuse with the host BMDC. Unfused transformed MSCs act as the cancer stem cell and are able to form tumors in successive mice, whereas fusion restores a nonmalignant phenotype. These data suggest that MSCs may play a key role in age-related tumors, and fusion with host cells restores a nonmalignant phenotype, thereby providing a mechanism for regulating tumor cell activity.

Investigation of DAZ and RBMY1 gene expression in human testis by quantitative real-time PCR

This study developed quantitative real-time PCR assays for the DAZ and RBMY1 genes to determine the copy number of RNA extracted from testicular biopsies from a cohort of normospermic controls (n=6) and azoospermic males (n=17) including two males with Y-chromosome microdeletions (AZFc and AZFb + c). All patients underwent testicular sperm extraction (TESE) for intracytoplasmic sperm injection (ICSI). Forty percent of the azoospermic cohort showed a significant reduction in the copies of at least one of the genes (DAZ P=0.003; RBMY1 P=0.009). The histopathology of these patients ranged from Sertoli cell only (SCO) to severe hypospermatogenesis with interstitial fibrosis. The patient with the AZFb + c deletion lacked expression of DAZ and RBMY1 and had a histopathology of SCO. The patient with the AZFc deletion had reduced expression of RBMY1 and no DAZ expression with a histopathology of spermatocyte arrest. The quantitative real-time PCR assays for DAZ and RBMY1 gave positive predictive values of 78% and 70%, respectively for the recovery of sperm from testicular biopsy.

A detailed analysis of the risk factors influencing local and distant breast cancer recurrence during adjuvant endocrine therapy

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Background: The ‘Arimidex’, Tamoxifen, Alone or in Combination (ATAC; ISRCTN18233230 ) trial compared the efficacy and safety of 5 years’ anastrozole, tamoxifen, or combination as adjuvant therapy for 9366 postmenopausal women with early invasive breast cancer. Here, risk factors influencing local and distant recurrences during the trial, independent of trial treatment, are assessed. Methods: The influence of standard baseline factors such as hormone receptor status, nodal involvement, tumor size, grade and age were evaluated on both local and distant recurrence rates. The use of other treatments (adjuvant chemotherapy, radiotherapy) and surgical status (mastectomy and axillary surgery) were also included. In addition, weight, body mass index, hysterectomy and prior hormone- replacement therapy were added. Cox models were used to analyze events by prognostic factors, and subsequently adjusted by country, before the production of confirmatory models. Results: For both local and distant recurrence, the highest risk correlated with poorer tumor differentiation, larger tumor size, increased nodal involvement and a negative hormone receptor status (see table ). While surgical status also affected the risk of developing a recurrence, previous treatments were less important, but residence in the USA showed a significant advantage. No association was seen with hysterectomy or weight for any recurrence. Conclusions: Although the pattern of risk varied for local and distant recurrence, tumor grade, size, and nodal involvement were the strongest risk factors for both. In comparison, the impact of previous treatments on hazard risk was lower. These data from a large international clinical trial confirm that women with less differentiated or larger tumors, and those with involved nodes, are at an increased risk of recurrence.

[Table: see text]

[Table: see text]

Homogeneity of mesothelial cells with lymphatic endothelium: expression of lymphatic endothelial markers by mesothelial cells

BACKGROUND

Mesothelial cell monolayers cover the serous cavities and internal organs, and provide a protective low-friction interface between apposed organs and tissues. The mesothelium also regulates inflammation, fluid and cell exchange, and tissue repair in these compartments and possibly tumor metastasis. In the present study, a stable pleural mesothelial cell line (MIM) was isolated and characterized, and the expression of several lymphatic specific markers by these cells examined.

METHODS AND RESULTS

MIM were isolated from mice stably expressing a temperature-sensitive SV40 large T antigen ('Immortomouse', strain: H-2K(b)-tsA58). These cells were compared with lymphatic endothelial cells (LEC) derived from the mesenteric adventitia of the Immortomouse. MIM and LEC expression of lymphatic-specific markers (Flt-4, LYVE-1, and Prox-1) was examined, and the tight junction protein (ZO-1) was studied by immunofluorescence and immunoblotting in these cells.

RESULTS

LYVE-1, Prox-1, and Flt-4 were detected in both MIM and LEC, with Prox-1 and LYVE-1 more strongly expressed on LEC than MIM. Conversely, Flt-4 was more densely expressed on MIM than on LEC. Spatially, ZO-1 was prominent at MIM junctions, but was less well organized in LEC.

CONCLUSION

MIM and LEC share several characteristic markers usually associated with lymphatic endothelium. MIM might be useful for studying the biology and pathology of mesothelial cells in vitro and help in the development of therapies for mesothelial-related diseases, such as mesothelioma and pleural effusion.

Gastrin-induced apoptosis contributes to carcinogenesis in the stomach

Hypergastrinemia in INS-GAS mice leads to accelerated carcinogenesis of the stomach, but the mechanisms have not been well defined. We investigated the possible role of gastrin-induced gastric cell apoptosis in the development of gastric cancer. We examined apoptosis and the expression of Bcl-2 family proteins in INS-GAS mice of different ages, as well as in gastrin-deficient (GAS-KO) mice after gastrin-17 (G-17) infusion. In addition, we studied the effects of the gastrin/cholecystokinin-2 (CCK-2) receptor antagonist YF476 and/or histamine H2 (H-2) receptor antagonist loxtidine on apoptosis and atrophy in INS-GAS mice with or without Helicobacter felis (H. felis) infection. INS-GAS mice had age-associated increases in Bax protein expression and decreases in Bcl-2 protein expression, along with increased glandular and epithelial cell apoptosis. At 8-week gastrin infusions in GAS-KO mice resulted in a similar pattern of altered Bax and Bcl-2 expression, followed by gastric cell apoptosis. H. felis infection of INS-GAS mice led to increased apoptosis and the development of atrophy, whereas treatment with either YF476 and/or loxtidine strongly inhibited both apoptosis and atrophy. In vitro studies with Fas-expressing RGM1 cells showed that gastrin stimulation alone directly induced apoptosis via gastrin/CCK-2 receptor and synergized with FasL stimulation. These results indicate that gastrin can induce apoptosis in gastric epithelial cells and contribute to the development of gastric carcinogenesis.

Comprehensive side-effect profile of anastrozole and tamoxifen as adjuvant treatment for early-stage breast cancer: long-term safety analysis of the ATAC trial

BACKGROUND

The Arimidex (anastrozole), Tamoxifen, Alone or in Combination (ATAC) trial was designed to compare the efficacy and safety of anastrozole with tamoxifen as adjuvant treatment for postmenopausal women with early-stage breast cancer. After an extended follow-up beyond the 5 years of treatment, we aimed to assess the safety, tolerability, and risk-benefit indices of these compounds.

METHODS

We analysed postmenopausal women (mean age 64 years [SD 9]) with localised breast cancer randomly assigned to anastrozole (n=3125) or tamoxifen (n=3116). Efficacy measures, including death and risk-benefit indices, were analysed by intention to treat. Safety analyses were based on treatment first received (n=3092 for anastrozole and n=3094 tamoxifen). We calculated a risk-benefit analysis using the two global indices for the Women's Health Initiative and for Disease-Free Survival and Serious Adverse Events. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN18233230.

FINDINGS

At median follow-up of 68 months (range 1-93), treatment-related adverse events occurred significantly less often with anastrozole than with tamoxifen (1884 [61%] vs 2117 [68%]; p<0.0001), as did treatment-related serious adverse events (146 [5%] vs 277 [9%]; p<0.0001) and adverse events leading to withdrawal (344 [11%] vs 442 [14%]; p=0.0002). Patients given anastrozole had significantly fewer overall events for the Global Index of the Women's Health Initiative (744 [24%] vs 851 [27%]; hazard ratio 0.85 [95% CI 0.77-0.94], p=0.001) and the Global Index of Disease-Free Survival and Serious Adverse Events (1453 [46%] vs 1594 [51%]; 0.88 [0.82-0.94]; p=0.0004).

INTERPRETATION

Anastrozole is tolerated better than tamoxifen by postmenopausal women with early-stage breast cancer, and results in fewer serious adverse events. Furthermore, it has a more favourable overall risk-benefit profile and lower recurrence rate than tamoxifen.