Lifetime Exposure to Cigarette Smoke, B Cell Tumor Immune Infiltration, and Immunoglobulin Abundance in Ovarian Tumors

BACKGROUND

Cigarette smoke exposure has been linked to systemic immune dysfunction, including for B cell and immunoglobulin (Ig) production, and poor outcomes in ovarian cancer patients. No study has evaluated the impact of smoke exposure across the lifecourse on B cell infiltration and Ig abundance in ovarian tumors.

METHODS

We measured markers of B and plasma cells and Ig isotypes using multiplex immunofluorescence on 395 ovarian cancer tumors in the Nurses' Health Study (NHS)/NHSII. We conducted beta-binomial analyses evaluating odds ratios (OR) and 95% confidence intervals (CI) for positivity of immune markers by cigarette exposure among cases and Cox proportional hazards models to evaluate hazard ratios (HR) and 95%CI for developing tumors with low (

RESULTS

There were no associations between smoke exposure and B cell or IgM infiltration in ovarian tumors. Among cases, we observed higher odds of IgA+ among ever smokers (OR: 1.54, 95%CI: 1.14, 2.07) and ever smokers with no parental smoke exposure (OR: 2.03, 95%CI: 1.18, 3.49) versus never smokers. Women with parental cigarette smoke exposure versus not had higher risk of developing ovarian cancer with low IgG+ (HR: 1.51, 95%CI: 1.10, 2.09), while ever versus never smokers had a lower risk (HR: 0.74, 95%CI: 0.56,0.99).

CONCLUSIONS

Ever smoking was associated with increased odds of IgA in ovarian tumors.

IMPACT

IgA has been associated with improved ovarian cancer outcomes, suggesting that although smoking is associated with poor outcomes in ovarian cancer patients, it may lead to improved tumor immunogenicity.

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Grants

• P01 CA087969 NCI NIH HHS
• U01 CA176726 NCI NIH HHS

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Affiliation(s)

Cassandra A Hathaway Moffitt Cancer Center, Tampa, FL, United States
Mary K Townsend Moffitt Cancer Center, Tampa, FL, United States
Tianyi Wang Moffitt Cancer Center, Tampa, FL, United States
Christine Vinci Moffitt Cancer Center, Tampa, FL, United States
Danielle E Jake-Schoffman University of Florida, Gainesville, Florida, United States
Jonathan L Hecht Harvard Medical School, Boston, MA, United States
Daryoush Saeed-Vafa Moffitt Cancer Center, Tampa, FL, United States
Carlos Moran Segura Moffitt Cancer Center, Tampa, FL, United States
Jonathan V Nguyen Moffitt Cancer Center, Tampa, FL, United States
Jose R Conejo-Garcia Duke University School of Medicine, Durham, NC, United States
Brooke L Fridley Moffitt Cancer Center, Tampa, FL, United States
Shelley S Tworoger Oregon Health & Science University School of Medicine, Portland, OR, United States

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The relationship of lifetime history of depression on the ovarian tumor immune microenvironment

BACKGROUND

Depression is associated with a higher ovarian cancer risk. Prior work suggests that depression can lead to systemic immune suppression, which could potentially alter the anti-tumor immune response.

METHODS

We evaluated the association of pre-diagnosis depression with features of the anti-tumor immune response, including T and B cells and immunoglobulins, among women with ovarian tumor tissue collected in three studies, the Nurses' Health Study (NHS; n = 237), NHSII (n = 137) and New England Case-Control Study (NECC; n = 215). Women reporting depressive symptoms above a clinically relevant cut-point, antidepressant use, or physician diagnosis of depression at any time prior to diagnosis of ovarian cancer were considered to have pre-diagnosis depression. Multiplex immunofluorescence was performed on tumor tissue microarrays to measure immune cell infiltration. In pooled analyses, we estimated odds ratios (OR) and 95% confidence intervals (CI) for the positivity of tumor immune cells using a beta-binomial model comparing those with and without depression. We used Bonferroni corrections to adjust for multiple comparisons.

RESULTS

We observed no statistically significant association between depression status and any immune markers at the Bonferroni corrected p-value of 0.0045; however, several immune markers were significant at a nominal p-value of 0.05. Specifically, there were increased odds of having recently activated cytotoxic (CD3+CD8+CD69+) and exhausted-like T cells (CD3+Lag3+) in tumors of women with vs. without depression (OR = 1.36, 95 %CI = 1.09-1.69 and OR = 1.24, 95 %CI = 1.01-1.53, respectively). Associations were comparable when considering high grade serous tumors only (comparable ORs = 1.33, 95 %CI = 1.05-1.69 and OR = 1.25, 95 %CI = 0.99-1.58, respectively). There were decreased odds of having tumor infiltrating plasma cells (CD138+) in women with vs. without depression (OR = 0.54, 95 %CI = 0.33-0.90), which was similar among high grade serous carcinomas, although not statistically significant. Depression was also related to decreased odds of having naïve and memory B cells (CD20+: OR = 0.54, 95 %CI = 0.30-0.98) and increased odds of IgG (OR = 1.22, 95 %CI = 0.97-1.53) in high grade serous carcinomas.

CONCLUSION

Our results provide suggestive evidence that depression may influence ovarian cancer outcomes through changes in the tumor immune microenvironment, including increasing T cell activation and exhaustion and reducing antibody-producing B cells. Further studies with clinical measures of depression and larger samples are needed to confirm these results.

Measurement of Ovarian Tumor Immune Profiles by Multiplex Immunohistochemistry: Implications for Epidemiologic Studies

BACKGROUND

Despite the immunogenic nature of many ovarian tumors, treatment with immune checkpoint therapies has not led to substantial improvements in ovarian cancer survival. To advance population-level research on the ovarian tumor immune microenvironment, it is critical to understand methodologic issues related to measurement of immune cells on tissue microarrays (TMA) using multiplex immunofluorescence (mIF) assays.

METHODS

In two prospective cohorts, we collected formalin-fixed, paraffin-embedded ovarian tumors from 486 cases and created seven TMAs. We measured T cells, including several sub-populations, and immune checkpoint markers on the TMAs using two mIF panels. We used Spearman correlations, Fisher exact tests, and multivariable-adjusted beta-binomial models to evaluate factors related to immune cell measurements in TMA tumor cores.

RESULTS

Between-core correlations of intratumoral immune markers ranged from 0.52 to 0.72, with more common markers (e.g., CD3+, CD3+CD8+) having higher correlations. Correlations of immune cell markers between the whole core, tumor area, and stromal area were high (range 0.69-0.97). In multivariable-adjusted models, odds of T-cell positivity were lower in clear cell and mucinous versus type II tumors (ORs, 0.13-0.48) and, for several sub-populations, were lower in older tissue (sample age > 30 versus ≤ 10 years; OR, 0.11-0.32).

CONCLUSIONS

Overall, high correlations between cores for immune markers measured via mIF support the use of TMAs in studying ovarian tumor immune infiltration, although very old samples may have reduced antigenicity.

IMPACT

Future epidemiologic studies should evaluate differences in the tumor immune response by histotype and identify modifiable factors that may alter the tumor immune microenvironment.

Abstract 3008: Association between distress and the tumor immune microenvironment in women with ovarian cancer

Various forms of distress, most notably depression, increase ovarian cancer risk. Prior work suggests depression can lead to systemic immune suppression; moreover, after ovarian cancer diagnosis, ongoing depression can lower tumor T cell infiltration. Here, we evaluated the relationship between pre-diagnosis depression and the ovarian tumor immune microenvironment.

Analyses were conducted among women with ovarian cancer in the Nurses’ Health Study (NHS; n=250), NHSII (n=122) and New England Case-Control Study (NEC; n=215). Self-report of depressive symptoms, antidepressant use, or physician diagnosis were used to define depression status. Multiplex immunofluorescence assays were performed on tumor tissue microarrays to measure infiltration of T cells, immune checkpoints, B cells, and immunoglobulins in the tumor area. In pooled analyses, we estimated odds ratios (OR) and 95% confidence intervals (CI) for positivity of tumor immune cells using a beta-binomial model within a repeated measures framework comparing those with and without depression.

Depression was not associated with abundance of CD3+ T cells, CD3+CD8+ cytotoxic T cells, or CD3+CD4+ T helper cells. However, we observed significantly increased odds of having recently activated cytotoxic (CD3+CD8+CD69+) and exhausted T cells (CD3+Lag3+) in tumors of women with vs. without depression (OR=1.34, 95%CI=1.08-1.65 and OR=1.25, 95%CI=1.02-1.53, respectively). Associations were comparable considering only high grade serous tumors (comparable ORs=1.31, 95%CI=1.04-1.65 and OR=1.25, 95%CI=1.00-1.56, respectively). No associations were observed for total B cells (CD19+) and naïve or memory B cells (CD20+). However, there were significantly decreased odds of having tumor infiltrating plasma cells (CD138+) in women with vs. without depression (OR=0.54, 95%CI=0.33-0.89). Among high grade serous carcinomas, the association with plasma cells was similar, though not statistically significant, and depression was related to decreased odds of having naïve and memory B cells (OR=0.56, 95%CI=0.32-0.97) and increased odds of IgG (OR=1.26, 95%CI=1.01-1.58).

Unexpectedly, we observed that immune cells indicative of T cell activation were higher in ovarian tumors of depressed vs. non-depressed women. This may be due to increased inflammation in women with depressive symptomology. Conversely, analyses of plasma cells suggested a reduced adaptive tumor immune response for women with vs. without depression. These results suggest depression may influence ovarian cancer outcomes through changes in the tumor immune microenvironment and that interventions to improve distress in ovarian cancer patients may be a potential strategy to improve outcomes.

Citation Format: Cassandra A. Hathaway, Mary K. Townsend, Jose R. Conejo-Garcia, Brooke L. Fridley, Carlos Moran Segura, Jonathan V. Nguyen, Naoko Sasamoto, Daryoush Saeed-Vafa, Kathryn L. Terry, Laura D. Kubzansky, Shelley S. Tworoger. Association between distress and the tumor immune microenvironment in women with ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3008.

Lifetime Exposure to Cigarette Smoke and Risk of Ovarian Cancer by T-cell Tumor Immune Infiltration

BACKGROUND

Exposure to cigarette smoke, particularly in early life, is modestly associated with ovarian cancer risk and may impact systemic immunity and the tumor immune response. However, no studies have evaluated whether cigarette smoke exposure impacts the ovarian tumor immune microenvironment.

METHODS

Participants in the Nurses' Health Study (NHS) and NHSII reported on early life exposure to cigarette smoke and personal smoking history on questionnaires (n = 165,760). Multiplex immunofluorescence assays were used to measure markers of T cells and immune checkpoints in tumor tissue from 385 incident ovarian cancer cases. We used Cox proportional hazards models to evaluate HRs and 95% confidence intervals (CI) for developing ovarian tumors with a low (<median) or high (≥median) immune cell percentage by cigarette exposure categories.

RESULTS

Women exposed versus not to cigarette smoke early in life had a higher risk of developing ovarian cancer with low levels of T cells overall (CD3+: HR: 1.54, 95% CI: 1.08-2.20) and recently activated cytotoxic T cells (CD3+CD8+CD69+: HR: 1.45, 95% CI: 1.05-2.00). These findings were not statistically significant at the Bonferroni-corrected P value of 0.0083. Adult smoking was not significantly associated with tumor immune markers after Bonferroni correction.

CONCLUSIONS

These results suggest early life cigarette smoke exposure may modestly increase risk of developing ovarian tumors with low abundance of total T cells and recently activated cytotoxic T cells.

IMPACT

Future research should focus on understanding the impact of exposures throughout the life course on the ovarian tumor immune microenvironment.

Combined nivolumab and ipilimumab with or without stereotactic body radiation therapy for advanced Merkel cell carcinoma: a randomised, open label, phase 2 trial

BACKGROUND

Merkel cell carcinoma is among the most aggressive and lethal of primary skin cancers, with a high rate of distant metastasis. Anti-programmed death receptor 1 (anti-PD-1) and programmed death ligand 1 (PD-L1) monotherapy is currently standard of care for unresectable, recurrent, or metastatic Merkel cell carcinoma. We assessed treatment with combined nivolumab plus ipilimumab, with or without stereotactic body radiotherapy (SBRT) in patients with advanced Merkel cell carcinoma as a first-line therapy or following previous treatment with anti-PD-1 and PD-L1 monotherapy.

METHODS

In this randomised, open label, phase 2 trial, we randomly assigned adults from two cancer sites in the USA (one in Florida and one in Ohio) to group A (combined nivolumab and ipilimumab) or group B (combined nivolumab and ipilimumab plus SBRT) in a 1:1 ratio. Eligible patients were aged at least 18 years with histologically proven advanced stage (unresectable, recurrent, or stage IV) Merkel cell carcinoma, a minimum of two tumour lesions measureable by CT, MRI or clinical exam, and tumour tissue available for exploratory biomarker analysis. Patients were stratified by previous immune-checkpoint inhibitor (ICI) status to receive nivolumab 240 mg intravenously every 2 weeks plus ipilimumab 1 mg/kg intravenously every 6 weeks (group A) or the same schedule of combined nivolumab and ipilimumab with the addition of SBRT to at least one tumour site (24 Gy in three fractions at week 2; group B). Patients had to have at least two measurable sites of disease so one non-irradiated site could be followed for response. The primary endpoint was objective response rate (ORR) in all randomly assigned patients who received at least one dose of combined nivolumab and ipilimumab. ORR was defined as the proportion of patients with a complete response or partial response per immune-related Response Evaluation Criteria in Solid Tumours. Response was assessed every 12 weeks. Safety was assessed in all patients. This trial is registered with ClinicalTrials.gov, NCT03071406.

FINDINGS

50 patients (25 in both group A and group B) were enrolled between March 14, 2017, and Dec 21, 2021, including 24 ICI-naive patients (13 [52%] of 25 group A patients and 11 [44%] of 25 group B patients]) and 26 patients with previous ICI (12 [48%] of 25 group A patients and 14 [56%] of 25 group B patients]). One patient in group B did not receive SBRT due to concerns about excess toxicity. Median follow-up was 14·6 months (IQR 9·1-26·5). Two patients in group B were excluded from the analysis of the primary endpoint because the target lesions were irradiated and so the patients were deemed non-evaluable. Of the ICI-naive patients, 22 (100%) of 22 (95% CI 82-100) had an objective response, including nine (41% [95% CI 21-63]) with complete response. Of the patients who had previously had ICI exposure, eight (31%) of 26 patients (95% CI 15-52) had an objective response and four (15% [5-36]) had a complete response. No significant differences in ORR were observed between groups A (18 [72%] of 25 patients) and B (12 [52%] of 23 patients; p=0·26). Grade 3 or 4 treatment-related adverse events were observed in 10 (40%) of 25 patients in group A and 8 (32%) of 25 patients in group B.

INTERPRETATION

First-line combined nivolumab and ipilimumab in patients with advanced Merkel cell carcinoma showed a high ORR with durable responses and an expected safety profile. Combined nivolumab and ipilimumab also showed clinical benefit in patients with previous anti-PD-1 and PD-L1 treatment. Addition of SBRT did not improve efficacy of combined nivolumab and ipilimumab. The combination of nivolumab and ipilimumab represents a new first-line and salvage therapeutic option for advanced Merkel cell carcinoma.

FUNDING

Bristol Myers Squibb Rare Population Malignancy Program.

Racial Differences in the Tumor Immune Landscape and Survival of Women with High-Grade Serous Ovarian Carcinoma

BACKGROUND

Tumor-infiltrating lymphocytes (TIL) confer a survival benefit among patients with ovarian cancer; however, little work has been conducted in racially diverse cohorts.

METHODS

The current study investigated racial differences in the tumor immune landscape and survival of age- and stage-matched non-Hispanic Black and non-Hispanic White women with high-grade serous ovarian carcinoma (HGSOC) enrolled in two population-based studies (n = 121 in each racial group). We measured TILs (CD3+), cytotoxic T cells (CD3+CD8+), regulatory T cells (CD3+FoxP3+), myeloid cells (CD11b+), and neutrophils (CD11b+CD15+) via multiplex immunofluorescence. Multivariable Cox proportional hazard regression was used to estimate the association between immune cell abundance and survival overall and by race.

RESULTS

Overall, higher levels of TILs, cytotoxic T cells, myeloid cells, and neutrophils were associated with better survival in the intratumoral and peritumoral region, irrespective of tissue compartment (tumor, stroma). Improved survival was noted for T-regulatory cells in the peritumoral region and in the stroma of the intratumoral region, but no association for intratumoral T-regulatory cells. Despite similar abundance of immune cells across racial groups, associations with survival among non-Hispanic White women were consistent with the overall findings, but among non-Hispanic Black women, most associations were attenuated and not statistically significant.

CONCLUSIONS

Our results add to the existing evidence that a robust immune infiltrate confers a survival advantage among women with HGSOC; however, non-Hispanic Black women may not experience the same survival benefit as non-Hispanic White women with HGSOC.

IMPACT

This study contributes to our understanding of the immunoepidemiology of HGSOC in diverse populations.

Genomic and Single-Cell Landscape Reveals Novel Drivers and Therapeutic Vulnerabilities of Transformed Cutaneous T-cell Lymphoma

ABSTRACT

Cutaneous T-cell lymphoma (CTCL) is a rare cancer of skin-homing T cells. A subgroup of patients develops large cell transformation with rapid progression to an aggressive lymphoma. Here, we investigated the transformed CTCL (tCTCL) tumor ecosystem using integrative multiomics spanning whole-exome sequencing (WES), single-cell RNA sequencing, and immune profiling in a unique cohort of 56 patients. WES of 70 skin biopsies showed high tumor mutation burden, UV signatures that are prognostic for survival, exome-based driver events, and most recurrently mutated pathways in tCTCL. Single-cell profiling of 16 tCTCL skin biopsies identified a core oncogenic program with metabolic reprogramming toward oxidative phosphorylation (OXPHOS), cellular plasticity, upregulation of MYC and E2F activities, and downregulation of MHC I suggestive of immune escape. Pharmacologic perturbation using OXPHOS and MYC inhibitors demonstrated potent antitumor activities, whereas immune profiling provided in situ evidence of intercellular communications between malignant T cells expressing macrophage migration inhibitory factor and macrophages and B cells expressing CD74.

SIGNIFICANCE

Our study contributes a key resource to the community with the largest collection of tCTCL biopsies that are difficult to obtain. The multiomics data herein provide the first comprehensive compendium of genomic alterations in tCTCL and identify potential prognostic signatures and novel therapeutic targets for an incurable T-cell lymphoma. This article is highlighted in the In This Issue feature, p. 1171.

2D or Synthetic 2D? A Reader Study of Visualization of Amorphous Calcifications

OBJECTIVE

Some vendors have created algorithms that generate synthetic 2D (s2D) images from a digital breast tomosynthesis (DBT) dataset to reduce the radiation from obtaining a separate 2D digital mammography (DM). This study evaluated the visibility of amorphous calcifications on 2D DM versus s2D on screening mammography.

METHODS

This IRB-approved, retrospective, reader study included screening mammograms from 36 women who received screening DBT exams where both 2D DM and s2D images were obtained: 28 screening mammograms that were eventually given BI-RADS category 4 or 5 for amorphous calcifications and 8 BI-RADS category 1 or 2 screening exams. Two rounds of interpretation were conducted with a six-week washout period. Cases were randomized to display either the 2D DM or s2D images, which were then alternated in the second round. Four fellowship-trained breast radiologists determined whether a study merited recall for calcifications. If so, they rated calcification visibility on a scale of 1 to 5. McNemar chi-square tests were conducted to assess differences in recall rates and Wilcoxon signed rank tests were used to examine shifts in visibility.

RESULTS

There was no difference in detection rates of amorphous calcifications between 2D DM and s2D, which were 75.9% and 75.0%, respectively (P = 1.000). Collectively, amorphous calcifications were more visible on s2D than 2D DM, with mean visibility scores of 3.4 versus 3.0, respectively (P = 0.005).

CONCLUSION

Synthetic 2D did not change identification of amorphous calcifications compared to 2D DM, and readers considered them more visible on average.

Abstract PO-034: Non-random spatial clustering of tumor associated macrophages is associated with poor survival in metastatic RCC patients receiving immunotherapy

INTRODUCTION Tumor associated macrophages (TAM) stimulate tumor proliferation and facilitate immune escape via production of immunosuppressive cytokines. We hypothesize that non-random spatial clustering of TAMs within the tumor is associated with poor survival in RCC patients. METHODS Primary and metastatic tumor specimens were obtained from 39 patients with metastatic RCC who received immunotherapy (IT). 29 patients (74.3%) also received targeted therapy (TT) at some point during their disease course. Sections from the tumor compartment underwent immunohistochemical (IHC) staining for pan-macrophage marker CD68, and M2 markers CD163 and CD206. Digital pathologic analysis was used to convert the digital images to spatial point pattern plots (PPP). A probability density function (PDF) for the distance between cells was calculated under the assumption that cells can be located anywhere in the slide with equal probability. The PDF was then compared to empirical histograms of cells derived from the PPP. Deviations from the PDF, the expected random distribution, reveal evidence of cell clustering or dispersion. We assessed deviations with the Kolmogorov-Smirnov (KS) test. Patients were stratified by the median value into high and low KS groups, and survival outcomes were compared between the two groups using a Cox regression. A high KS statistic indicates a good fit between the two curves (in this case, randomness), and a low KS statistic indicates a poor fit (in this case, dispersion or clustering). RESULTS Among primary tumor specimens, spatial clustering of CD68+ cells was associated with worse overall survival (OS) (HR -1.7, p=0.015), worse OS from IT initiation (HR -1.5, p=0.025), and no difference in OS from TT initiation (HR -0.4, p=0.48). Among metastatic tumor specimens, spatial clustering of CD68+ cells was not associated with any of the three survival outcomes (OS: HR 0.9, p=0.11; OS from IT: HR 0.7, p=0.20; OS from TT: HR 0.0, p=0.97). Spatial clustering of CD163+ cells was not associated with any of the three survival outcomes for either primary and metastatic sites. Spatial clustering of CD206+ cells was not associated with any of the three survival outcomes for either primary and metastatic sites. CONCLUSION Non-random spatial clustering of CD68+ TAMs in the primary tumor specimen was associated with worse survival, driven primarily by worse survival from initiation of immunotherapy. These findings corroborate prior reports of TAMs eliciting an immunosuppressive effect on the tumor-immune microenvironment, introduce novel methodology for quantifying spatial heterogeneity, and demonstrate the novel finding of a clinically significant effect of TAM spatial clustering on overall survival.

Citation Format: Gregory J. Kimmel, Nicholas H. Chakiryan, Youngchul Kim, Ali J. Hajiran, Ahmet M. Aydin, Jonathan V. Nguyen, Carlos M. Moran-Segura, Jasreman Dhillon, Philipp Altrock, Brandon J. Manley. Non-random spatial clustering of tumor associated macrophages is associated with poor survival in metastatic RCC patients receiving immunotherapy [abstract]. In: Proceedings of the AACR Virtual Special Conference on Tumor Heterogeneity: From Single Cells to Clinical Impact; 2020 Sep 17-18. Philadelphia (PA): AACR; Cancer Res 2020;80(21 Suppl):Abstract nr PO-034.

Beyond BRCA: Review of Hereditary Syndromes Predisposing to Breast Cancer

The majority of our hereditary breast cancer genes incur not only an increased risk for breast cancer but for other malignancies as well. Knowing whether an individual carries a pathogenic variant in a hereditary breast cancer gene can affect not only screening for the patient but for his or her family members as well. Identifying and appropriately testing individuals via multigene panels allows for risk reduction and early surveillance in at-risk individuals. Radiologists can serve as first-line identifiers of women who are at risk of having an inherited predisposition to breast cancer because they are interacting with all women receiving routine screening mammograms, and collecting family history suggestive of the presence of a mutation. We outline here the 11 genes associated with high breast cancer risk discussed in the National Comprehensive Cancer Network Genetic/Familial High-Risk: Breast and Ovarian (version 3.2019) as having additional breast cancer screening recommendations outside of annual mammography to serve as a guide for breast cancer screening and risk reduction, as well as recommendations for surveillance of nonbreast cancers.

JAK/STAT pathway inhibition overcomes IL7-induced glucocorticoid resistance in a subset of human T-cell acute lymphoblastic leukemias

While outcomes for children with T-cell acute lymphoblastic leukemia (T-ALL) have improved dramatically, survival rates for patients with relapsed/refractory disease remain dismal. Prior studies indicate that glucocorticoid (GC) resistance is more common than resistance to other chemotherapies at relapse. In addition, failure to clear peripheral blasts during a prednisone prophase correlates with an elevated risk of relapse in newly diagnosed patients. Here we show that intrinsic GC resistance is present at diagnosis in early thymic precursor (ETP) T-ALLs as well as in a subset of non-ETP T-ALLs. GC-resistant non-ETP T-ALLs are characterized by strong induction of JAK/STAT signaling in response to interleukin-7 (IL7) stimulation. Removing IL7 or inhibiting JAK/STAT signaling sensitizes these T-ALLs, and a subset of ETP T-ALLs, to GCs. The combination of the GC dexamethasone and the JAK1/2 inhibitor ruxolitinib altered the balance between pro- and anti-apoptotic factors in samples with IL7-dependent GC resistance, but not in samples with IL7-independent GC resistance. Together, these data suggest that the addition of ruxolitinib or other inhibitors of IL7 receptor/JAK/STAT signaling may enhance the efficacy of GCs in a biologically defined subset of T-ALL.

Redox reactivity of guanyl radicals in plasmid DNA

PURPOSE

It has been previously argued that gamma-irradiation of plasmid DNA in the presence of thiocyanate ions produces products recognized by the E. coli base excision-repair endonuclease formamidopyrimidine-DNA N-glycosylase (FPG), and there that derive from an intermediate guanyl radical species. The wish was to characterize the reactivity of this intermediate with reducing agents.

MATERIALS AND METHODS

Aqueous solutions of plasmid DNA containing either bromide or thiocyanate (10(-3) to 10(-1) mol dm(-3)) and also one of six other additives (azide, ferrocyanide, iodide, nitrite, promethazine, tryptophan, 10(-7) to 10(-3) mol dm(-3)) were subjected to 137Cs gamma-irradiation (662 keV). After irradiation, the plasmid was incubated with FPG. Strand break yields before and after incubation were determined by agarose gel electrophoresis under neutral conditions.

RESULTS

The very high yields of FPG-sensitive sites in the presence of SCN- or Br- decreased significantly with increasing concentrations of all of the six additives, with promethazine and tryptophan being the most efficient additives, and azide and iodide the least.

CONCLUSIONS

From the results it is possible to estimate values of the rate constants for the reduction of the DNA guanyl radical (5 x 10(5), 2 x 10(5), 10(7) and 10(7) dm3 mol(-1) s(-1) for ferrocyanide, nitrite, promethazine and tryptophan respectively).

In vitro and in vivo evaluation of effects of sodium caprate on enteral peptide absorption and on mucosal morphology

Sodium salts of medium-chain fatty acids, sodium caprate (C10) in particular, have been used as absorption-enhancing agents to promote transmucosal drug absorption. In this study, we conducted both in vitro and in vivo experiments to investigate the effects of C10 on intestinal permeabilities and mucosal morphology. Mucosal addition of C10 (13-25 mM) reduced the transepithelial electric resistance (TEER) of cultured monolayers of the human intestinal cell line Caco-2 by 40-65% and, upon removal of C10, a marked tendency of TEER recovery was recorded. C10 added mucosally at 13-50 mM increased the transports of mannitol and polyethylene glycol (PEG) 900 across Caco-2 in a dose-dependent manner. In contrast, the transport of a model D-decapeptide was maximally enhanced with 20-25 mM C10. No noticeable morphological alteration of the Caco-2 monolayers was observed after a 1-h mucosal pretreatment with C10. Co-delivery with C10 (0.05-0.5 mmol/kg) into the rat terminal ileum increased the D-decapeptide bioavailability (BA) dose-dependently. With 0.5 mmol/kg C10 co-administered, D-decapeptide percent BA was elevated from 2 to 11%. Following a 1-h incubation with 0.5 mmol/kg C10 (in liquid or powder form) non-invasively delivered into the rectal lumen, no signs of histological change in the rectal mucosa were detected. These results demonstrate that C10 can promote intestinal absorption of a small peptide without causing detrimental alterations of the intestinal mucosa. C10 thus seems to be a good candidate as an enhancing agent for improving the oral BA of small therapeutic peptides.

Enhancement of intestinal model compound transport by DS-1, a modified Quillaja saponin

DS-1, a modified Quillaja saponin, has recently been shown to promote the absorption of insulin and aminoglycoside antibiotics via the ocular and nasal route. The purpose of this study is to investigate the effect of DS-1 on intestinal permeability, the mechanism of its action, and reversibility of the effect. The permeation-enhancing activity of DS-1 was evaluated in cultured monolayers of the Caco-2 intestinal epithelial cells by examining its effect on the transepithelial electric resistance (TEER) and on transport of mannitol and a model D-decapeptide. Mucosal addition of DS-1 promptly reduced the TEER of the Caco-2 monolayers, and a propensity of recovery of the TEER was observed upon its removal. DS-1 added at 0.01-0.1% (w/v) increased the transports of both mannitol and D-decapeptide in a dose-dependent manner; a relatively "flat" concentration-dependence was seen at 0.1-0.2%. Visualization studies conducted by confocal laser scanning microscopy (CLSM) seem to suggest that DS-1 enhances the Caco-2 permeability mainly via a transcellular route. Histological examination failed to reveal noticeable morphological alterations in the cell monolayers pretreated with DS-1. The integrity of the Caco-2 monolayers, as assessed by their permeability to mannitol, was found to be recoverable following the mucosal pretreatment of DS-1. These results suggest that DS-1 is an efficacious intestinal permeation-enhancing agent with low adverse effect on the epithelial viability and barrier function.