Citations

ABSTRACT Microbiota-modulating strategies, including probiotic administration, have been tested for the treatment of chronic gastrointestinal diseases despite limited information regarding their mechanisms of action. We previously demonstrated that patients with active celiac disease have decreased duodenal expression of elafin, a human serine protease inhibitor, and supplementation of elafin by a recombinant Lactococcus lactis strain prevents gliadin-induced immunopathology in the NOD/DQ8 mouse model of gluten sensitivity. The commensal probiotic strain Bifidobacterium longum NCC2705 produces a serine protease inhibitor (Srp) that exhibits immune-modulating properties. Here, we demonstrate that B. longum NCC2705, but not a srp knockout mutant, attenuates gliadin-induced immunopathology and impacts intestinal microbial composition in NOD/DQ8 mice. Our results highlight the beneficial effects of a serine protease inhibitor produced by commensal B. longum strains. IMPORTANCE Probiotic therapies have been widely used to treat gastrointestinal disorders with variable success and poor mechanistic insight. Delivery of specific anti-inflammatory molecules has been limited to the use of genetically modified organisms, which has raised some public and regulatory concerns. By examining a specific microbial product naturally expressed by a commensal bacterial strain, we provide insight into a mechanistic basis for the use of B. longum NCC2705 to help treat gluten-related disorders.

Assessment of tumor-infiltrating lymphocytes (TILs) in histopathologic specimens can provide important prognostic information in diverse solid tumor types, and may also be of value in predicting response to treatments. However, implementation as a routine clinical biomarker has not yet been achieved. As successful use of immune checkpoint inhibitors and other forms of immunotherapy become a clinical reality, the need for widely applicable, accessible, and reliable immunooncology biomarkers is clear. In part 1 of this review we briefly discuss the host immune response to tumors and different approaches to TIL assessment. We propose a standardized methodology to assess TILs in solid tumors on hematoxylin and eosin sections, in both primary and metastatic settings, based on the International Immuno-Oncology Biomarker Working Group guidelines for TIL assessment in invasive breast carcinoma. A review of the literature regarding the value of TIL assessment in different solid tumor types follows in part 2. The method we propose is reproducible, affordable, easily applied, and has demonstrated prognostic and predictive significance in invasive breast carcinoma. This standardized methodology may be used as a reference against which other methods are compared, and should be evaluated for clinical validity and utility. Standardization of TIL assessment will help to improve consistency and reproducibility in this field, enrich both the quality and quantity of comparable evidence, and help to thoroughly evaluate the utility of TILs assessment in this era of immunotherapy.

Abstract We sought to understand the comprehensiveness of consumer-oriented information describing the availability of shared access to adult patient portals from publicly reported information on institutional websites of 20 large and geographically diverse health systems. All 20 health systems reported that they offer patients the ability to share access to their patient portal account with a family member or friend; however, the comprehensiveness of information regarding registration procedures, features, and terminology varied widely. Half of the systems (n = 10) reported having shared access available on their patient portal registration webpage. Few systems (n = 2) reported affording patients the ability to differentiate specific role-based privileges. No systems reported uptake of shared access among adult patients, which was variably described as “proxy,” “caregiver,” “parental,” or “delegate” access. Findings suggest that engaging families through health information technology will require greater efforts to promote awareness and differentiate privileges that respect patients’ choice and control in information-sharing preferences.

Assessment of the immune response to tumors is growing in importance as the prognostic implications of this response are increasingly recognized, and as immunotherapies are evaluated and implemented in different tumor types. However, many different approaches can be used to assess and describe the immune response, which limits efforts at implementation as a routine clinical biomarker. In part 1 of this review, we have proposed a standardized methodology to assess tumor-infiltrating lymphocytes (TILs) in solid tumors, based on the International Immuno-Oncology Biomarkers Working Group guidelines for invasive breast carcinoma. In part 2 of this review, we discuss the available evidence for the prognostic and predictive value of TILs in common solid tumors, including carcinomas of the lung, gastrointestinal tract, genitourinary system, gynecologic system, and head and neck, as well as primary brain tumors, mesothelioma and melanoma. The particularities and different emphases in TIL assessment in different tumor types are discussed. The standardized methodology we propose can be adapted to different tumor types and may be used as a standard against which other approaches can be compared. Standardization of TIL assessment will help clinicians, researchers and pathologists to conclusively evaluate the utility of this simple biomarker in the current era of immunotherapy.

Abstract The hematological malignancy acute myeloid leukemia (AML) interacts closely with osteoblasts within the protective bone marrow microenvironment. The bone marrow microenvironment protects tumor cells from chemotherapies, which can prevent sufficient eradication of tumor cells. To study the role of osteoblasts in the bone marrow microenvironment, our lab utilized a co-culture model of osteoblasts (MC3T3 osteoblast cell line) and acute myelogenous leukemia cells (KG1a AML cell line or AML patient samples from bone marrow aspirates). Osteoblasts were cultured with AML cells, or AML cells were cultured alone; AML cells were challenged with the standard chemotherapeutic agent cytarabine (Ara-C) at doses of 0µM, 0.1µM, 0.5µM, 1µM, 5µM, or 10µM in the presence or absence of osteoblasts; and AML cells were assayed by flow cytometry to assess cell death via annexin-V staining. Our lab has previously found that differentiating osteoblasts protect AML cells from an apoptosis inducing agent naturally present in the bone marrow. We now show that osteoblasts are also capable of protecting AML cells from the standard chemotherapeutic cytarabine. In addition, we have found that treatment of osteoblasts with the histone deacetylase inhibitor (HDACi) suberoylanilide hydroxamic acid (SAHA) prevents these treated osteoblasts from protecting AML cells from cytarabine treatment, which is consistent with our lab’s previous findings that HDACi treatment inhibits protection of AML cells from an apoptosis inducing agent naturally present in the bone marrow. We have preliminary data that indicates that TAZS89A over-expression, a constitutively active form of TAZ, which is a transcriptional modulator that regulates osteoblast differentiation, may be sufficient to inhibit osteoblast mediated protection of AML cells from cytarabine. This finding would be consistent with the HDACi manipulated Nherf1-protein phosphatase 1α-TAZ signaling pathway that we have previously found to be sufficient to inhibit protection of AML cells from an apoptosis inducing agent naturally present in the bone marrow. Overall, these studies have delivered insights into the role of osteoblasts in protecting AML cells from chemotherapy in the bone marrow microenvironment and begun the characterization of mechanisms and targets responsible for the protective effects of osteoblasts. Manipulating differentiating osteoblasts within the bone marrow microenvironment therapeutically could aid in more complete destruction of the tumor cell burden and improve patient survival. Citation Format: Rosalie M. Sterner, Kimberly N. Kremer, Amel Dudakovic, Jennifer J. Westendorf, Andre J. van Wijnen, Karen E. Hedin. Osteoblasts protect AML cells from cytarabine-induced death [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5930. doi:10.1158/1538-7445.AM2017-5930

Abstract Background: Patients (pts) with CLL/SLL who use unmutated IGHV (u-CLL) have a less favorable outcome with standard chemotherapy than pts who use mutated IGHV (m-CLL). Ibrutinib (ibr) inhibits B-cell receptor signaling through Bruton’s tyrosine kinase and has robust clinical activity against CLL. This integrated analysis of 3 phase 3 studies examined the impact of IGHV status on ibr- and comparator (comp)-treated pts. Methods: Pooled data from 3 studies of ibr (420 mg/d) in CLL/SLL pts (RESONATE: relapsed/refractory [R/R] pts, ibr vs ≤ 24 weeks ofatumumab; RESONATE-2: treatment-naïve [TN] pts ≥ 65 yrs of age [no del17p], ibr vs ≤ 12 cycles chlorambucil; HELIOS: R/R pts [no del17p], ≤ 6 cycles bendamustine-rituximab with ibr vs placebo) were analyzed by IGHV status. Analyses included Kaplan-Meier method (overall survival [OS]; progression-free survival [PFS]); log-rank test (group comparisons); and Cox multivariate analysis (prognostic factors; Table). Results: For 491 ibr- (366 u-CLL, 125 m-CLL) and 494 comp-treated (351 u-CLL, 143 m-CLL) pts with IGHV data, baseline characteristics were similar for u-CLL vs m-CLL, except for the proportions of pts who were TN (17 vs 31%), had bulky disease (60 vs 37%), or had CLL cells with del11q (32 vs 16%). Median follow up was 21.4 mos for ibr and 20.6 mos for comp. PFS and OS were similar for u-CLL and m-CLL ibr-treated pts; u-CLL had poorer outcomes than m-CLL in comp-treated pts, which remained after adjustment for prognostic factors (Table). Ibr treatment was more effective than comp regardless of IGHV status. Incidence of adverse events (AEs) was similar between groups. For ibr vs comp pts (u-CLL/m-CLL): serious AEs: 49% (50%/47%) vs 36.5% (37%/35%); AEs that led to discontinuation: 12% (11%/15%) vs 13% (13%/14%); death within 30 days of last dose: 5% (6%/3%) vs 5% (6%/2%). Conclusions: U-CLL was an adverse predictor of outcome for comp-treated, but not for ibr-treated pts. Table.Efficacy Outcomes in Ibr- and Comparator-Treated Patients by IGHV Mutation StatusIbrutinib (N=491)Comparator (N =494)u-CLL (n=717)m-CLL (n=268)u-CLL(n=366): m-CLL(n=125)u-CLL(n=351): m-CLL(n=143)Ibr(n=366): Comp(n=351)Ibr (n=125): Comp (n=143)PFS24-month rate HR78%:81%10%:32%78%:10%81%:32%0.93a1.99a0.12b0.21bp = 0.78p < 0.0001p < 0.0001p <0.0001Adjusted HRc1.02a1.94a0.11b0.17bp = 0.93p < 0.0001p < 0.0001p < 0.0001OS24-month rate HR88%:89%78%:87%88%:78%89%:87%0.95a1.96a0.49b0.85b,ep = 0.86p = 0.02p < 0.01p = 0.66Adjusted HRc1.21a2.10a0.49bNAp =0.57p = 0.01p < 0.001Response ratesu-CLLm-CLLu-CLLm-CLLIbrCompIbrCompORR, %d8990475189479051p = 0.96p = 0.36p < 0.0001p < 0.0001CR, %d221546224156p = 0.10p = 0.44p < 0.0001p = 0.01CI, confidence interval; CR, complete response; HR, hazard ratio; ORR, overall response rate; NA, not applicable. aHR < 1 favors unmutated. bHR < 1 favors ibrutinib. cMultivariate Cox model adjusted for age, sex, current Rai stage, baseline ECOG performance status score, del11q, del17p, number of prior therapies, and cytopenias. dp value is from a Cochran-Mantel-Haenszel chi-square test. eInsufficient number of events prevents meaningful analysis, only 13 and 16 events observed in ibr and comp groups, respectively, and 46 (32%) pts in comp arm crossed over to ibr arm; interpret results with caution. Citation Format: Thomas J. Kipps, Graeme Fraser, Steven Coutre, Jennifer R. Brown, Jacqueline C. Barrientos, Paul M. Barr, John C. Byrd, Susan M. O'Brien, Marie-Sarah Dilhuydy, Stephen Devereux, Ulrich Jaeger, Carol Moreno, Paula Cramer, Stephan Stilgenbauer, Asher A. Chanan-Khan, Michelle Mahler, Mariya Salman, Mei Cheng, Anil Londhe, Joi Ninomoto, Angela Howes, Danelle James, Michael Hallek. Unmutated IGHV is not an adverse predictor of outcome to therapy with ibrutinib in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT158. doi:10.1158/1538-7445.AM2017-CT158

Abstract Addressing underrepresentation of minorities and women as research participants has largely focused on clinical trials, while little is known about attitudes and knowledge regarding other types of biomedical research, e.g., epidemiologic and genetic studies. These types of studies are essential for advances in cancer research, including development of targeted therapies for women and minorities. As part of an academic/community partnership between Mayo Clinic and The Links, Incorporated, a national volunteer service organization of professional African American women, this study sought to: (1) examine attitudes regarding participation in research involving access to the medical record, genetic studies/biobanking, and clinical trials; and (2) develop and evaluate a novel, targeted online educational program addressing these 3 types of biomedical research. Initial qualitative inquiry via 3 focus groups (n=34) found that most women associated health-related research with clinical trials; few women were familiar with other study types. Women expressed more concerns about how information is collected, used, and shared by investigators than with personal mistreatment in research regardless of study type (genetic research (GEN), chart review (CR), clinical trial (CT)) or the kind of information (social, health, genetic) collected. The importance of investigator transparency regarding the significance of the disease in African Americans, research funding source, the investigator’s agenda, and commitment to the population being studied was emphasized. Qualitative results informed development of the educational program. A total of 244 Links members completed the program (77% response rate) and answered pre- and post-assessments of intentions, attitudes and knowledge. The percent of women indicating that they “definitely” or “probably” intend to participate in research increased from 9.4% to 19.5% and 27.1% to 49.8%, respectively, after program completion. Agreement with the statement “research in the U.S. is ethical” increased from 52.9% to 74.4%. Factual knowledge related to each of the 3 study types also increased. Prior to completing the program many women reported “little or no understanding” of the 3 types of studies (66% GEN, 62.9% CR, 40.7% CT) whereas after program completion, these numbers decreased to 24.9%, 18.4%, and 15.5%, respectively. While few women rated their opinion of the study types as “very positive” prior to beginning the program (14.3% GEN, 15.0% CR, 28.6% CT), upon completion these proportions increased and equalized (42.8% GEN, 43.0% CR, 42.5% CT). Two-month follow-up will evaluate longer-term impact including knowledge dissemination, visiting clinicaltrials.gov, and enrolling in ResearchMatch. An online education-to-action program targeting professional African American women improved knowledge, perceptions of research ethics, and intent to participate in biomedical research. Citation Format: Carmen Radecki Breitkopf, Karen P. Williams, Jennifer L. Ridgeway, Alice L. Strong Simmons, Monica W. Parker, Michele Y. Halyard, Sharonne N. Hayes. Linking education to action: A program to increase research participation among African American women [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4233. doi:10.1158/1538-7445.AM2017-4233

Abstract Introduction: Potent targeting of the androgen receptor (AR) in castration-resistant prostate cancer (CRPC) has altered the archetypal course of the disease, fueling the emergence of aggressive and incurable neuroendocrine prostate cancer (NEPC). Alarmingly, no targeted therapies exist for NEPC, which stems from our poor molecular understanding of the disease. What regulates the plasticity that allows cells to shed their dependence on the AR and re-emerge as “AR-indifferent” NEPC, especially under the pressure of modern AR pathway inhibitors (ARPIs) such as enzalutamide (ENZ)? Recent data suggest that neuroendocrine transdifferentiation is aligned with dynamic reprogramming of the epigenome by developmental regulators, like EZH2, making them attractive therapeutic targets. Method: To uncover reprogramming factors that are activated in response to AR pathway inhibition, we interrogated a panel of cell lines derived from ENZ-resistant prostate tumors by RNA-seq. Mirroring what is observed in a subset of patients who progress on ENZ, 25% of ENZ-resistant tumors and matched cell lines displayed reduction in canonical AR pathway activity and a NEPC phenotype. Gene set enrichment analysis revealed that these cells are enriched for a Polycomb/EZH2 signature and share a conserved transcriptional program with embryonic stem cells. In particular, we identified a distinct phosphorylated form of EZH2 (EZH2-T350), upregulated in AR-indifferent/NEPC cell lines and patient tumors, that was found to be indispensable for the emergence and maintenance of a stem-like state. Results: Blocking EZH2-T350 phosphorylation in AR-indifferent/NEPC cell lines yielded a marked reduction in expression of pluripotency transcription factors and stem-like features, including ALDH activity and spheroid formation capacity. Notably, EZH2-T350 was found to be sufficient and required for cells to enter a transient stem-like state, a pre-requisite for neuroendocrine transdifferentiation under the pressure of ARPIs both in vitro and in patient-derived prostate tumor xenografts. As our data revealed a strong association between EZH2 and AR in response to ENZ we performed ChIP-seq and observed extensive reprogramming of the AR cistrome, specifically at a core set of genes governing stem cell identity. EZH2 colocalized at the reprogrammed AR binding sites. Accordingly, treating AR-indifferent/NEPC cell lines with the EZH2 inhibitor GSK126 yielded a molecular subtype shift from PCS1 to AR-driven PCS2, and re-sensitized cells to ARPIs. Conclusion: Our findings establish the centrality of epigenetic reprogramming in driving the insurgence of a clinically aggressive neuroendocrine phenotype in response to AR pathway inhibition. Drugging the epigenome via EZH2 inhibition to reverse the NEPC state and re-sensitize tumors to our powerful arsenal of ARPIs has the potential to transform the treatment of prostate cancer. Citation Format: Alastair Davies, Musa Ahmed, Chiara Bostock, Anna Gleave, Kirsi Ketola, Fraser Johnson, Jennifer Bishop, Ladan Fazli, Haojie Huang, Hansen He, Amina Zoubeidi. EZH2 reprogramming confers intrinsic stem cell properties and developmental plasticity driving neuroendocrine prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5025. doi:10.1158/1538-7445.AM2017-5025