Lysophosphatidic acid (LPA) acts on LPA2 receptor to mediate multiple pathological effects that are associated with tumorigenesis. The absence of LPA2 attenuates tumor progression in rodent models of colorectal cancer, but whether overexpression of LPA2 alone can lead to malignant transformation in the intestinal tract has not been studied. In this study, we expressed human LPA2 in intestinal epithelial cells (IECs) under control of the villin promoter. Less than 4% of F1-generation mice had germline transmission of transgenic (TG) human LPA2; as such only 3 F1 mice out of 72 genotyped had TG expression. These TG mice appeared anemic with hematochezia and died shortly after birth. TG mice were smaller in size compared with the wild type mouse of the same age and sex. Morphological analysis showed that TG LPA2 colon had hyper-proliferation of IECs resulting in increased colonic crypt depth. Surprisingly, TG small intestine had villus blunting and decreased IEC proliferation and dysplasia. In both intestine and colon, TG expression of LPA2 compromised the terminal epithelial differentiation, consistent with epithelial dysplasia. Furthermore, we showed that epithelial dysplasia was observed in founder mouse intestine, correlating LPA2 overexpression with epithelial dysplasia. The current study demonstrates that overexpression of LPA2 alone can lead to intestinal dysplasia.
Lysophosphatidic acid (LPA) acts on LPA2 receptor to mediate multiple pathological effects that are associated with tumorigenesis. The absence of LPA2 attenuates tumor progression in rodent models of colorectal cancer, but whether overexpression of LPA2 alone can lead to malignant transformation in the intestinal tract has not been studied. In this study, we expressed human LPA2 in intestinal epithelial cells (IECs) under control of the villin promoter. Less than 4% of F1-generation mice had germline transmission of transgenic (TG) human LPA2; as such only 3 F1 mice out of 72 genotyped had TG expression. These TG mice appeared anemic with hematochezia and died shortly after birth. TG mice were smaller in size compared with the wild type mouse of the same age and sex. Morphological analysis showed that TG LPA2 colon had hyper-proliferation of IECs resulting in increased colonic crypt depth. Surprisingly, TG small intestine had villus blunting and decreased IEC proliferation and dysplasia. In both intestine and colon, TG expression of LPA2 compromised the terminal epithelial differentiation, consistent with epithelial dysplasia. Furthermore, we showed that epithelial dysplasia was observed in founder mouse intestine, correlating LPA2 overexpression with epithelial dysplasia. The current study demonstrates that overexpression of LPA2 alone can lead to intestinal dysplasia.
The RNA polymerase II transcription cycle is often divided into three major stages: initiation, elongation, and termination. Research over the last decade has blurred these divisions and emphasized the tightly regulated transitions that occur as RNA polymerase II synthesizes a transcript from start to finish. Transcription termination, the process that marks the end of transcription elongation, is regulated by proteins that interact with the polymerase, nascent transcript, and/or chromatin template. The failure to terminate transcription can cause accumulation of aberrant transcripts and interfere with transcription at downstream genes. Here, we review the mechanism, regulation, and physiological impact of a termination pathway that targets small noncoding transcripts produced by RNA polymerase II. We emphasize the Nrd1-Nab3-Sen1 pathway in yeast, in which the process has been extensively studied. The importance of understanding small RNA termination pathways is underscored by the need to control noncoding transcription in eukaryotic genomes.
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Shishir Maithel;
J Gerry;
LM Postlewait;
J Prescott;
T Wang;
JA Glenn;
J Phay;
K Keplinger;
RC Fields;
L Jin;
S Weber;
AI Salem;
J Sicklick;
S Gad;
A Yopp;
J Mansour;
Q Duh;
N Seiser;
CC Solorzano;
CM Kiernan;
K Votanopoulos;
EA Levine;
I Hatzaras;
R Shenoy;
TM Pawlik;
G Poultsides
Background: Lymph node metastasis is an established predictor of poor outcome for adrenocortical carcinoma (ACC); however, routine lymphadenectomy during surgical resection of ACC is not widely performed and its therapeutic role remains unclear. Methods: Patients undergoing margin-negative resection for localized ACC were identified from a multi-institutional database. Patients were stratified into 2 groups based on the surgeon’s effort or not to perform a lymphadenectomy as documented in the operative note. Clinical, pathologic, and outcome data were compared between the 2 groups. Results: Of 120 patients who met inclusion criteria from 1993 to 2014, 32 (27 %) underwent lymphadenectomy. Factors associated with lymphadenectomy were tumor size (12 vs. 9.5 cm; p = .007), palpable mass at presentation (26 vs. 12 %; p = .07), suspicious lymph nodes on preoperative imaging (44 vs. 7 %; p < .001), and need for multivisceral resection (78 vs. 36 %; p < .001). Median number of lymph nodes harvested was higher in the lymphadenectomy group (5.5 vs. 0; p < .001). In-hospital mortality (0 vs. 1.3 %; p = .72) and grade 3/4 complication rates (0 vs. 12 %; p = .061) were not significantly different. Patients who underwent lymphadenectomy had improved overall survival (5-year 76 vs. 59 %; p = .041). The benefit of lymphadenectomy on overall survival persisted on multivariate analysis (HR = 0.17; p = .006) controlling for adverse preoperative and intraoperative factors associated with lymphadenectomy, such as tumor size, palpable mass, irregular tumor edges, suspicious nodes on imaging, and multivisceral resection. Conclusions: In this multicenter study of adrenocortical carcinoma patients undergoing R0 resection, the surgeon’s effort to dissect peritumoral lymph nodes was independently associated with improved overall survival.
Vitamin A deficiency (VAD) is an important contributor to child morbidity and mortality. The prevalence of VAD, measured by retinol-binding protein (RBP) or retinol, is overestimated in populations with a high prevalence of inflammation. We aimed to quantify and adjust for the effect of inflammation on VAD prevalence in a nationally representative survey of Liberian children 6 to 35months of age. We compared five approaches to adjust RBP for inflammation and estimate VAD prevalence (defined as RBP<0.7μmol/L): (1) ignoring inflammation; (2) excluding individuals with inflammation (C-reactive protein (CRP) >5mg/L or alpha1-acid glycoprotein (AGP) >1g/)L; (3) multiplying each individual's RBP by an internal correction factor; (4) by an external correction factor; and (5) using regression (corrected RBP=exp(InRBP - β1(lnCRPobs-lnCRPref) - β2(lnAGPobs-lnAGPref)). Corrected RBP was based on a regression model where reference lnCRP and lnAGP were set to the maximum of the lowest decile. The unadjusted prevalence of VAD was 24.7%. Children with elevated CRP and/or AGP had significantly lower RBP concentrations than their apparently healthy peers (geometric mean RBP 0.79μmol/L (95% CI: 0.76, 0.82) vs. 0.95μmol/L (95% CI: 0.92, 0.97), P<0.001). Using approaches 2-5 resulted in a prevalence of VAD of 11.6%, 14.3%, 13.5% and 7.3%, respectively. Depending on the approach, the VAD prevalence is reduced 10-17 percentage points when inflammation is taken into account. Further quantification of the influence of inflammation on biomarkers of vitamin A status from other national surveys is needed to compare and recommend the preferred adjustment approach across populations.
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Himalee Sabnis;
Rama Amara;
Harriet Robinson;
S Kannanganat;
LS Wyatt;
S Gangadhara;
V Chamcha;
LS Chea;
PA Kozlowski;
CC LaBranche;
L Chennareddi;
B Lawson;
PBJ Reddy;
TM Styles;
TH Vanderford;
DC Montefiori;
B Moss
We tested, in rhesus macaques, the effects of a 500-fold range of an admixed recombinant modified vaccinia Ankara (MVA) expressing rhesus GM-CSF (MVA/GM-CSF) on the immunogenicity and protection elicited by an MVA/SIV macaque 239 vaccine. High doses of MVA/GM-CSF did not affect the levels of systemic envelope (Env)-specific Ab, but it did decrease the expression of the gut-homing receptor α4β7 on plasmacytoid dendritic cells (p < 0.01) and the magnitudes of Env-specific IgA (p = 0.01) and IgG (p < 0.05) in rectal secretions. The protective effect of the vaccine was evaluated using 12 weekly rectal challenges in rhesus macaques subgrouped by tripartite motif-containing protein 5a (TRIM5a) genotypes that are restrictive or permissive for infection by the challenge virus SIVsmE660. Eight of nine TRIM5a-restrictive animals receiving no or the lowest dose (1 × 10 5 PFU) of MVA/GM-CSF resisted all 12 challenges. In the comparable TRIM5α-permissive group, only 1 of 12 animals resisted all 12 challenges. In the TRIM5a-restrictive animals, but not in the TRIM5α-permissive animals, the number of challenges to infection directly correlated with the magnitudes of Env-specific rectal IgG (r = +0.6) and IgA (r = +0.6), the avidity of Env-specific serum IgG (r = +0.5), and Ab dependent cell-mediated virus inhibition (r = +0.6). Titers of neutralizing Ab did not correlate with protection. We conclude that 1) protection elicited by MVA/SIVmac239 is strongly dependent on the presence of TRIM5a restriction, 2) nonneutralizing Ab responses contribute to protection against SIVsmE660 in TRIM5a-restrictive animals, and 3) high doses of codelivered MVA/GM-CSF inhibit mucosal Ab responses and the protection elicited by MVA expressing noninfectious SIV macaque 239 virus-like particles.
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Shuguang Leng;
Guodong Wu;
Donna M. Klinge;
Cynthia L. Thomas;
Elia Casas;
Maria A. Picchi;
Christine A. Stidley;
Sandra J. Lee;
Seena Aisner;
Jill M. Siegfried;
Suresh Ramalingam;
Fadlo Khuri;
Daniel D. Karp;
Steven A. Belinsky
CT screening for lung cancer reduces mortality, but will cost Medicare ~2 billion dollars due in part to high false positive rates. Molecular biomarkers could augment current risk stratification used to select smokers for screening. Gene methylation in sputum reflects lung field cancerization that remains in lung cancer patients postresection. This population was used in conjunction with cancer-free smokers to evaluate classification accuracy of a validated eight-gene methylation panel in sputum for cancer risk. Sputum from resected lung cancer patients (n=487) and smokers from Lovelace (n=1380) and PLuSS (n=718) cohorts was studied for methylation of an 8-gene panel. Area under a receiver operating characteristic curve was calculated to assess the prediction performance in logistic regressions with different sets of variables. The prevalence for methylation of all genes was significantly increased in the ECOG-ACRIN patients compared to cancer-free smokers as evident by elevated odds ratios that ranged from 1.6 to 8.9. The gene methylation panel showed lung cancer prediction accuracy of 82-86% and with addition of clinical variables improved to 87-90%. With sensitivity at 95%, specificity increased from 25% to 54% comparing clinical variables alone to their inclusion with methylation. The addition of methylation biomarkers to clinical variables would reduce false positive screens by ruling out onethird of smokers eligible for CT screening and could increase cancer detection rates through expanding risk assessment criteria.