Obesogenic high-fat diet heightens aerobic glycolysis through hyperactivation of oncogenic KRAS

Oncogenic KRAS plays a vital role in controlling tumor metabolism by enhancing aerobic glycolysis. Obesity driven by chronic consumption of high-fat diet (HFD) is a major risk factor for oncogenic KRAS-mediated pancreatic ductal adenocarcinoma (PDAC). However, the role of HFD in KRAS-mediated metabolic reprogramming has been obscure. Here, by using genetically engineered mouse models expressing an endogenous level of KRASG12D in pancreatic acinar cells, we demonstrate that hyperactivation of KRASG12D by obesogenic HFD, as compared to carbohydrate-rich diet, is responsible for enhanced aerobic glycolysis that associates with critical pathogenic responses in the path towards PDAC. Ablation of Cox-2 attenuates KRAS hyperactivation leading to the reversal of both aggravated aerobic glycolysis and high-grade dysplasia under HFD challenge. Our data highlight a pivotal role of the cooperative interaction between obesity-ensuing HFD and oncogenic KRAS in driving the heightened aerobic glycolysis during pancreatic tumorigenesis and suggest that in addition to directly targeting KRAS and aerobic glycolysis pathway, strategies to target the upstream of KRAS hyperactivation may bear important therapeutic value.

Influence of Crohn's disease related polymorphisms in innate immune function on ileal microbiome

We have previously identified NOD2 genotype and inflammatory bowel diseases (IBD) phenotype, as associated with shifts in the ileal microbiome ("dysbiosis") in a patient cohort. Here we report an integrative analysis of an expanded number of Crohn's disease (CD) related genetic defects in innate immune function (NOD2, ATG16L1, IRGM, CARD9, XBP1, ORMDL3) and composition of the ileal microbiome by combining the initial patient cohort (Batch 1, 2005-2010, n = 165) with a second consecutive patient cohort (Batch 2, 2010-2012, n = 118). These combined patient cohorts were composed of three non-overlapping phenotypes: 1.) 106 ileal CD subjects undergoing initial ileocolic resection for diseased ileum, 2.) 88 IBD colitis subjects without ileal disease (predominantly ulcerative colitis but also Crohn's colitis and indeterminate colitis, and 3.) 89 non-IBD subjects. Significant differences (FDR < 0.05) in microbiota were observed between macroscopically disease unaffected and affected regions of resected ileum in ileal CD patients. Accordingly, analysis of the effects of genetic and clinical factors were restricted to disease unaffected regions of the ileum. Beta-diversity differed across the three disease categories by PERMANOVA (p < 0.001), whereas no significant differences in alpha diversity were noted. Using negative binomial models, we confirmed significant effects of IBD phenotype, C. difficile infection, and NOD2 genotype on ileal dysbiosis in the expanded analysis. The relative abundance of the Proteobacteria phylum was positively associated with ileal CD and colitis phenotypes, but negatively associated with NOD2R genotype. Additional associations with ORMDL3 and XBP1 were detected at the phylum/subphylum level. IBD medications, such as immunomodulators and anti-TNFα agents, may have a beneficial effect on reversing dysbiosis associated with the IBD phenotype. Exploratory analysis comparing microbial composition of the disease unaffected region of the resected ileum between 27 ileal CD patients who subsequently developed endoscopic recurrence within 6-12 months versus 34 patients who did not, suggested that microbial biomarkers in the resected specimen helped stratify patients with respect to risk of post-surgical recurrence.

[Effects of Different Concentrations of Lanthanum on the Growth and Uptake of Pb by Maize Grown Under Moderate Lead Stress]

A greenhouse pot experiment was conducted to investigate the effects of different concentrations of lanthanum (0 mg·kg^-1, 50 mg·kg^-1, 200 mg·kg^-1 and 800 mg·kg^-1) on growth, nutrient uptake, C:N:P stoichiometry, and La and Pb uptake by maize (Zea mays L.) under moderate lead stress (200 mg·kg^-1) and evaluate the interaction of rare earth elements and heavy metals in the soil-plant system. The aim was to provide basic data and a theoretical basis for the remediation of rare earth element and heavy metal-co-contaminated soils in a rare earths mining area. The results indicate that the concentrations of CH₃COONH₄-EDTA-extractable La and Pb significantly increase and decrease, respectively, with increasing La concentrations of the soils. The shoot dry weights of maize significantly decreases by 17.90% to 81.17% and the root to shoot ratio of maize significantly increases by 21.74% to 86.96% with increasing La concentrations of the soils. With increasing La concentrations in soils, the root P contents of maize significantly decrease by 19.16% to 89.68%. The shoot P and N contents significantly decrease by 65.51% to 91.98% and 48.27% to 76.58%, respectively, when the exogenous application of La is 200 mg·kg^-1 and 800 mg·kg^-1, respectively. The increasing La concentrations in soils significantly increase the C:P and N:P ratios and shoot and root La concentrations of maize. The shoot and root Pb concentrations of maize significantly increase by 52.61% to 99.01% and 15.99% to 44.34%, respectively, with increasing La concentrations. Overall, the increasing La concentrations in soils significantly decrease the K, Ca, and Mg contents of maize. The results demonstrate that the presence of rare earth elements aggravates the phytotoxicity of heavy metals to plant and ecological risks. Further research should focus on the effects and mechanisms of rare earth elements on the heavy metal uptake by plants.

The catalytic mechanism of S-acyltransferases: acylation is triggered on by a loose transition state and deacylation is turned off by a tight transition state

The reaction of S-acyltransferase is characterized by a loose transition state.

Orkambi® and amplifier co-therapy improves function from a rare CFTR mutation in gene-edited cells and patient tissue

The combination therapy of lumacaftor and ivacaftor (Orkambi^®) is approved for patients bearing the major cystic fibrosis (CF) mutation: ΔF508. It has been predicted that Orkambi^® could treat patients with rarer mutations of similar “theratype”; however, a standardized approach confirming efficacy in these cohorts has not been reported. Here, we demonstrate that patients bearing the rare mutation: c.3700 A>G, causing protein misprocessing and altered channel function—similar to ΔF508‐CFTR, are unlikely to yield a robust Orkambi^® response. While in silico and biochemical studies confirmed that this mutation could be corrected and potentiated by lumacaftor and ivacaftor, respectively, this combination led to a minor in vitro response in patient‐derived tissue. A CRISPR/Cas9‐edited bronchial epithelial cell line bearing this mutation enabled studies showing that an “amplifier” compound, effective in increasing the levels of immature CFTR protein, augmented the Orkambi^® response. Importantly, this “amplifier” effect was recapitulated in patient‐derived nasal cultures—providing the first evidence for its efficacy in augmenting Orkambi^® in tissues harboring a rare CF‐causing mutation. We propose that this multi‐disciplinary approach, including creation of CRISPR/Cas9‐edited cells to profile modulators together with validation using primary tissue, will facilitate therapy development for patients with rare CF mutations.

Successful creation of pancreatic cancer organoids by means of EUS-guided fine-needle biopsy sampling for personalized cancer treatment

BACKGROUND AND AIMS

Pancreatic cancer organoids are tumor models of individualized human pancreatic ductal adenocarcinoma (PDA), created from surgical specimens and used for personalized treatment strategies. Unfortunately, most patients with PDA are not operative candidates. Creation of human PDA organoids at the time of initial tumor diagnosis is therefore critical. Our aim was to assess the feasibility of creating human PDA organoids by EUS fine-needle biopsy (EUS-FNB) sampling in patients with PDA.

METHODS

In this prospective clinical trial in patients referred to evaluate a pancreatic mass, EUS-FNA was performed for initial onsite diagnosis. Two additional needle passes were performed with a 22-gauge FNB needle for organoid creation. Primary outcome was successful isolation of organoids within 2 weeks of EUS-FNB sampling (P0, no passages), confirmed by organoid morphology and positive genotyping.

RESULTS

Thirty-seven patients with 38 PDA tumors were enrolled. Successful isolation of organoids (P0) was achieved in 33 of 38 tumors (87%). Establishment of PDA organoid lines for ≥5 passages of growth (P5, five passages) was reached in 25 of 38 tumors (66%). In the single patient with successful P5 FNB sampling-derived and P5 surgically derived organoids, there was identical matching of specimens. There were no serious adverse events. Two patients developed bleeding at the EUS-FNB puncture site requiring hemostasis clips.

CONCLUSIONS

Pancreatic cancer organoids can be successfully and rapidly created by means of EUS-FNB sampling using a 22-gauge needle at the time of initial diagnosis. Successful organoid generation is essential for precision medicine in patients with pancreatic cancer in whom most are not surgically resectable. (Clinical trial registration number: NCT03140592.).

Organoid Profiling Identifies Common Responders to Chemotherapy in Pancreatic Cancer

Pancreatic cancer is the most lethal common solid malignancy. Systemic therapies are often ineffective, and predictive biomarkers to guide treatment are urgently needed. We generated a pancreatic cancer patient-derived organoid (PDO) library that recapitulates the mutational spectrum and transcriptional subtypes of primary pancreatic cancer. New driver oncogenes were nominated and transcriptomic analyses revealed unique clusters. PDOs exhibited heterogeneous responses to standard-of-care chemotherapeutics and investigational agents. In a case study manner, we found that PDO therapeutic profiles paralleled patient outcomes and that PDOs enabled longitudinal assessment of chemosensitivity and evaluation of synchronous metastases. We derived organoid-based gene expression signatures of chemosensitivity that predicted improved responses for many patients to chemotherapy in both the adjuvant and advanced disease settings. Finally, we nominated alternative treatment strategies for chemorefractory PDOs using targeted agent therapeutic profiling. We propose that combined molecular and therapeutic profiling of PDOs may predict clinical response and enable prospective therapeutic selection.Significance: New approaches to prioritize treatment strategies are urgently needed to improve survival and quality of life for patients with pancreatic cancer. Combined genomic, transcriptomic, and therapeutic profiling of PDOs can identify molecular and functional subtypes of pancreatic cancer, predict therapeutic responses, and facilitate precision medicine for patients with pancreatic cancer. Cancer Discov; 8(9); 1112-29. ©2018 AACR.See related commentary by Collisson, p. 1062This article is highlighted in the In This Issue feature, p. 1047.

Gasoline exhaust damages spermatogenesis through downregulating α6-integrin and β1-integrin in the rat model

The health influence of air pollution has been an international public health concern. Increasing evidence has suggested that air pollution has been associated with decreased sperm quality. However, the underlying molecular mechanisms are still not fully elucidated. We aimed to verify whether gasoline exhaust leads to reproductive impairment by injuring spermatogonial stem cells and explore its underlying molecular mechanism. Twenty male Sprague-Dawley rats were randomly divided into two groups: the exposure group (n = 10) and the control group (n = 10). After 6-month exposure, the sperm count and morphology were determined. The histological changes in the seminiferous tubules were examined by HE staining. The expression of α6-integrin and β1-integrin was assessed with Quantitative RT-PCR, Western blot and Immunohistochemical staining. Compared with control group, male rats exposed to gasoline exhaust showed significantly reduced sperm count, increased sperm abnormality rate and the total number of spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids were decreased. (all p < .01). The expression levels of α6-integrin and β1-integrin in the exposure group were significantly lower than those in the control group (all p < .01). Our study showed that exposure to gasoline exhaust caused impairment to spermatogonial stem cells through downregulating α6-integrin and β1-integrin.

Production and Characterization of a Tumor-Specific Monoclonal Antibody Act19 Recognizing an Epitope Distinctive from Sialosyl-Tn on the TAG72 Antigen

Aims

A murine monoclonal antibody ACT19 directed at the TAG72 tumor-associated antigen, which was originally defined by the B72.3 antibody, was established.

Methods

This was done by immunizing mice with the bovine mucin followed by the selection of hybridomas secreting antibodies with the desired specificity. In order to better characterize this antibody, its immunoreactivity was compared to that of the B72.3 antibody.

Results

The data showed that the ACT19 antibody bound specifically to the TAG72 antigen as the B72.3 antibody did. However, there were some differences between ACT19 and B72.3. Firstly, the immunoreactivity of ACT19 for the bovine mucin was lower than that of B72.3. Secondly, the immunoreactivity of ACT19 for the TAG72 antigen was not inhibited by N-acetylgalactosamine, nor was that of B72.3. Thirdly, ACT19 did not compete the binding reactivity of B72.3 for the TAG72 antigen. This suggests that the epitope defined by ACT19 is different from the sialosyl-Tn epitope recognized by B72.3. Immunoperoxidase staining of various tumors, normal and embryonic tissues for ACT19 was carried out. For the various tumors, only adenocarcinomas from the colon and stomach showed remarkable positivity. All the normal tissues were negative, except for weak positivity involving the zona reticularis of the adrenal cortex, and intestinal goblet cells. Embryonic tissues showed a wide spectrum of positivity with staining of the small and large intestine, stomach and renal tubules.

Conclusions

The ACT19 antibody appears to be a useful marker for colon and stomach cancers, and this additional anti-TAG72 antibody may be useful in conjunction with the B72.3 antibody in pathology and clinical application.

Abstract P2-09-23: Diffusion-weighted MRI improves imaging prediction of response in the I-SPY 2 trial

Background: The I-SPY 1 TRIAL demonstrated that functional tumor volume (FTV) measured by dynamic contrast-enhanced (DCE) MRI during neoadjuvant chemotherapy (NAC) predicts both pathologic complete response (pCR) and recurrence free survival1. In addition to DCE, the I-SPY 2 TRIAL is testing whether diffusion weighted MRI (DWI), a non-contrast method that characterizes water mobility and cellularity by measuring the apparent diffusion coefficient (ADC), acquired during the same MRI exam as DCE, can provide valuable distinct information about tumor response. We hypothesize that combining FTV and ADC can improve the predictive performance of breast MRI.

Methods: I-SPY 2 includes women with stage II or III breast cancer with tumor size ≥ 2.5 cm. A sub-cohort of I-SPY 2 patients from 2 graduated experimental drug arms2,3 (N=115 of 263): veliparib-carboplatin (VC, N=38), neratinib (N=37) and their controls (treated with paclitaxel or paclitaxel + trastuzumab, N=40), were included in this study: 148 patients were excluded due to missing imaging data or poor DWI quality. Each patient had four MRI exams: pre-treatment (T1), early treatment (after 3 weekly cycles of experimental drugs, T2), between regimen (T3), and pre-surgery (T4). FTV and ADC were measured for the whole tumor at T1, T2, and T3. Percent change of FTV (ΔFTV) and ADC (ΔADC) at T2 and T3 compared to T1 were analyzed as predictors of pCR. The predictive performance of ΔFTV, ΔADC and their combination was evaluated using a logistic regression model treating pCR as the binary outcome. Odds ratios were estimated for each 10% decrease of ΔFTV and 10% increase of ΔADC to reach pCR. The likelihood ratio test was used to evaluate the effect of variables in the logistic model. The statistical significance level for all testing was set at 0.05.

Results: Out of 115 patients included in this analysis, 36 (31%) reached pCR. The combined model using ΔFTV+ΔADC showed statistically significant improvement over the single predictor ΔFTV alone (p=0.038 for the period T1 to T2 and p&lt;0.001 for the period T1 to T3). The odds ratio estimates represent a 27% increase in odds for each 10% increase in ΔADC after accounting for ΔFTV at T2 and 38% increase at T3 (see Table 1).

Table 1 The odds ratio of ΔFTV and ΔADC with 95% confidence intervalTreatment time pointΔFTV aloneΔADC aloneΔADC adjusted for ΔFTVEarly treatment (T2)1.19 (1.05, 1.36)1.33 (1.06, 1.70)1.27 (1.01, 1.63)Bwteeen regimen (T3)1.41 (1.12, 1.98)1.44 (1.24, 1.71)1.38 (1.18, 1.64)

Conclusion: The addition of ADC to standard FTV MRI may help refine the prediction of treatment response. Evaluation of the method by cancer subtype in a larger cohort is ongoing.

References

1. Hylton NM, Gatsonis CA, Rosen MA, et al. Neoadjuvant Chemotherapy for Breast Cancer: Functional Tumor Volume by MR Imaging Predicts Recurrence-free Survival-Results from the ACRIN 6657/CALGB 150007 I-SPY 1 TRIAL. Radiology. 2016;279(1):44-55.

2. Rugo HS, Olopade OI, DeMichele A, et al. Adaptive Randomization of Veliparib-Carboplatin Treatment in Breast Cancer. N Engl J Med. 2016;375(1):23-34.

3. Park JW, Liu MC, Yee D, et al. Adaptive Randomization of Neratinib in Early Breast Cancer. N Engl J Med. 2016;375(1):11-22.

Citation Format: Li W, Wilmes LJ, Newitt DC, Jones EF, Gibbs J, Poon M, Li E, Partridge SC, Kornak J, Esserman LJ, Hylton NM. Diffusion-weighted MRI improves imaging prediction of response in the I-SPY 2 trial [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-09-23.

Impaired granulocyte-macrophage colony-stimulating factor bioactivity accelerates surgical recurrence in ileal Crohn’s disease

AIM

To examine the relationship between elevated granulocyte-macrophage colony-stimulating factor (GM-CSF) auto-antibodies (Ab) level and time to surgical recurrence after initial surgery for Crohn’s disease (CD).

METHODS

We reviewed 412 charts from a clinical database at tertiary academic hospital. Patients included in the study had ileal or ileocolonic CD and surgical resection of small bowel or ileocecal region for management of disease. Serum samples were analyzed for serological assays including GM-CSF cytokine, GM-CSF Ab, ASCA IgG and IgA, and genetic markers including SNPs rs2066843, rs2066844, rs2066845, rs2076756 and rs2066847 in NOD2, rs2241880 in ATG16L1, and rs13361189 in IRGM. Cox proportional-hazards models were used to assess the predictors of surgical recurrence.

RESULTS

Ninety six percent of patients underwent initial ileocecal resection (ICR) or ileal resection (IR) and subsequently 40% of patients required a second ICR/IR for CD. GM-CSF Ab level was elevated at a median of 3.81 mcg/mL. Factors predicting faster time to a second surgery included elevated GM-CSF Ab [hazard ratio (HR) 3.52, 95%CI: 1.45-8.53, P = 0.005] and elevated GM-CSF cytokine (HR = 2.48, 95%CI: 1.31-4.70, P = 0.005). Factors predicting longer duration between first and second surgery included use of Immunomodulators (HR = 0.49, 95%CI: 0.31-0.77, P = 0.002), the interaction effect of low GM-CSF Ab levels and smoking (HR = 0.60, 95%CI: 0.45-0.81, P = 0.001) and the interaction effect of low GM-CSF cytokine levels and ATG16L1 (HR = 0.65, 95%CI: 0.49-0.88, P = 0.006).

CONCLUSION

GM-CSF bioavailability plays a critical role in maintaining intestinal homeostasis. Decreased bioavailability coupled with the genetic risk markers and/or smoking results in aggressive CD behavior.

Longitudinal microbiome analysis of single donor fecal microbiota transplantation in patients with recurrent Clostridium difficile infection and/or ulcerative colitis

Background

Studies of colonoscopic fecal microbiota transplant (FMT) in patients with recurrent CDI, indicate that this is a very effective treatment for preventing further relapses. In order to provide this service at Stony Brook University Hospital, we initiated an open-label prospective study of single colonoscopic FMT among patients with ≥ 2 recurrences of CDI, with the intention of monitoring microbial composition in the recipient before and after FMT, as compared with their respective donor. We also initiated a concurrent open label prospective trial of single colonoscopic FMT of patients with ulcerative colitis (UC) not responsive to therapy, after obtaining an IND permit (IND 15642). To characterize how FMT alters the fecal microbiota in patients with recurrent Clostridia difficile infections (CDI) and/or UC, we report the results of a pilot microbiome analysis of 11 recipients with a history of 2 or more recurrences of C. difficile infections without inflammatory bowel disease (CDI-only), 3 UC recipients with recurrent C. difficile infections (CDI + UC), and 5 UC recipients without a history of C. difficile infections (UC-only).

Method

V3V4 Illumina 16S ribosomal RNA (rRNA) gene sequencing was performed on the pre-FMT, 1-week post-FMT, and 3-months post-FMT recipient fecal samples along with those collected from the healthy donors. Fitted linear mixed models were used to examine the effects of Group (CDI-only, CDI + UC, UC-only), timing of FMT (Donor, pre-FMT, 1-week post-FMT, 3-months post-FMT) and first order Group*FMT interactions on the diversity and composition of fecal microbiota. Pairwise comparisons were then carried out on the recipient vs. donor and between the pre-FMT, 1-week post-FMT, and 3-months post-FMT recipient samples within each group.

Results

Significant effects of FMT on overall microbiota composition (e.g., beta diversity) were observed for the CDI-only and CDI + UC groups. Marked decreases in the relative abundances of the strictly anaerobic Bacteroidetes phylum, and two Firmicutes sub-phyla associated with butyrate production (Ruminococcaceae and Lachnospiraceae) were observed between the CDI-only and CDI + UC recipient groups. There were corresponding increases in the microaerophilic Proteobacteria phylum and the Firmicutes/Bacilli group in the CDI-only and CDI + UC recipient groups. At a more granular level, significant effects of FMT were observed for 81 genus-level operational taxonomic units (OTUs) in at least one of the three recipient groups (p<0.00016 with Bonferroni correction). Pairwise comparisons of the estimated pre-FMT recipient/donor relative abundance ratios identified 6 Gammaproteobacteria OTUs, including the Escherichia-Shigella genus, and 2 Fusobacteria OTUs with significantly increased relative abundance in the pre-FMT samples of all three recipient groups (FDR < 0.05), however the magnitude of the fold change was much larger in the CDI-only and CDI + UC recipients than in the UC-only recipients. Depletion of butyrate producing OTUs, such as Faecalibacterium, in the CDI-only and CDI + UC recipients, were restored after FMT.

Conclusion

The results from this pilot study suggest that the microbial imbalances in the CDI + UC recipients more closely resemble those of the CDI-only recipients than the UC-only recipients.

Genetic differentiation of regional populations of the widespread Asiatic toad (Bufo gargarizans), as revealed by development of novel microsatellite markers

Dispersal is a key component of a species’ life history, by influencing population persistence, genetic structure, adaptation and maintenance of genetic diversity. The Asiatic toad (Bufo gargarizans) is a widespread species in east Asia. However, we still have no knowledge of what kind of geographical scale equates to genetic differentiation within B. gargarizans. In this study, the population genetics of B. gargarizans was studied at five localities, with the Yangtze River running through the sampling area, in order to detect the level of genetic differentiation and the natural barriers to the species’ dispersal on a small geographic scale, by means of the development and use of novel microsatellite loci. These markers revealed a relatively high level of genetic diversity. Distinct genetic structure among populations in B. gargarizans was observed, as described by genetic distance, AMOVA, PCA and Geneland results. A weak but significant positive correlation between genetic distance and geographical distance. The combination of these findings suggests that the Yangtze River and geographic distance may act as effective barriers for B. gargarizans. These results serve as benchmark data for understanding the impacts of dispersal barriers and continued landscape research on B. gargarizans.

[Effects of Arbuscular Mycorrhizal Fungi on the Growth and Uptake of La and Pb by Maize Grown in La and Pb-Contaminated Soil]

A greenhouse pot experiment was conducted to investigate the effects of arbuscular mycorrhizal (AM) fungi Claroideoglomus etunicatum (CE) and Rhizophagus intraradices (RI) on AM colonization rate, biomass, nutrient uptake, C:N:P stoichiometry, and the uptake and transport of lanthanum (La) and lead (Pb) by maize (Zea mays L.) grown in La-and Pb-contaminated soils (combined La-Pb concentrations of 50, 200, and 800 mg·kg^-1). The aim was to provide a scientific basis for the remediation of soils contaminated by rare earth elements and heavy metals. The results indicated that symbiotic associations were successfully established between the two isolates and maize, and the average AM colonization rate ranged from 26.7% to 95.8%. The increasing concentrations of La and Pb in soils significantly decreased the mycorrhizal colonization rate, biomass, and mineral nutrition concentrations of the maize, and significantly increased C:P and N:P ratios and the concentrations of La and Pb in shoots and roots of maize. The shoot and root dry weights of maize were significantly increased by 17.8%-158.9% with two AM fungi inoculations, while the P concentration of shoots and roots of the maize were significantly increased by 24.5%-153.8%. Inoculation with two AM fungi decreased the C:P and N:P ratios, consistent with the growth rate hypothesis. With AM fungi inoculation in three types of La-Pb co-contaminated soils, root Pb concentrations of the maize significantly increased by 51.3%-67.7%; shoot Pb concentrations of the maize significantly decreased by 16.0%-67.7%; and the transport rate of Pb from root to shoot of the maize decreased by 31.5%-54.7%. Meanwhile, inoculation with AM fungi significantly increased the shoot La concentrations in the maize grown in soils mildly contaminated with La-Pb, while it significantly decreased shoot La concentrations, increased root La concentrations of maize, and inhibited the transport of La from root to shoot of the maize grown in soils moderately contaminated with La-Pb, but had no significant effect in severely contaminated soils. The results showed that AM fungi had the potential to promote phytoremediation of soils contaminated with rare earth elements and heavy metals, with potential applications to revegetate such contaminated soil ecosystems.

Re: Genome-Wide Association Study Identifies African-Specific Susceptibility Loci in African Americans With Inflammatory Bowel Disease

BACKGROUND & AIMS

The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn’s disease (CD) cause significant morbidity and are increasing in prevalence among all populations, including African Americans. More than 200 susceptibility loci have been identified in populations of predominantly European ancestry, but few loci have been associated with IBD in other ethnicities.

METHODS

We performed 2 high-density, genome-wide scans comprising 2345 cases of African Americans with IBD (1646 with CD, 583 with UC, and 116 inflammatory bowel disease unclassified) and 5002 individuals without IBD (controls, identified from the Health Retirement Study and Kaiser Permanente database). Single-nucleotide polymorphisms (SNPs) associated at P < 5.0 × 10⁻⁸ in meta-analysis with a nominal evidence (P < .05) in each scan were considered to have genome-wide significance.

RESULTS

We detected SNPs at HLA-DRB1, and African-specific SNPs at ZNF649 and LSAMP, with associations of genome-wide significance for UC. We detected SNPs at USP25 with associations of genome-wide significance for IBD. No associations of genome-wide significance were detected for CD. In addition, 9 genes previously associated with IBD contained SNPs with significant evidence for replication (P < 1.6 × 10⁻⁶): ADCY3, CXCR6, HLA-DRB1 to HLA-DQA1 (genome-wide signifi-cance on conditioning), IL12B, PTGER4, and TNC for IBD; IL23R, PTGER4, and SNX20 (in strong linkage disequilibrium with NOD2) for CD; and KCNQ2 (near TNFRSF6B) for UC. Several of these genes, such as TNC (near TNFSF15), CXCR6, and genes associated with IBD at the HLA locus, contained SNPs with unique association patterns with African-specific alleles.

CONCLUSIONS

We performed a genome-wide association study of African Americans with IBD and identified loci associated with UC in only this population; we also replicated IBD, CD, and UC loci identified in European populations. The detection of variants associated with IBD risk in only people of African descent demonstrates the importance of studying the genetics of IBD and other complex diseases in populations beyond those of European ancestry.

Genome-Wide Association Study Identifies African-Specific Susceptibility Loci in African Americans With Inflammatory Bowel Disease

BACKGROUND & AIMS

The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn's disease (CD) cause significant morbidity and are increasing in prevalence among all populations, including African Americans. More than 200 susceptibility loci have been identified in populations of predominantly European ancestry, but few loci have been associated with IBD in other ethnicities.

METHODS

We performed 2 high-density, genome-wide scans comprising 2345 cases of African Americans with IBD (1646 with CD, 583 with UC, and 116 inflammatory bowel disease unclassified) and 5002 individuals without IBD (controls, identified from the Health Retirement Study and Kaiser Permanente database). Single-nucleotide polymorphisms (SNPs) associated at P < 5.0 × 10-8 in meta-analysis with a nominal evidence (P < .05) in each scan were considered to have genome-wide significance.

RESULTS

We detected SNPs at HLA-DRB1, and African-specific SNPs at ZNF649 and LSAMP, with associations of genome-wide significance for UC. We detected SNPs at USP25 with associations of genome-wide significance for IBD. No associations of genome-wide significance were detected for CD. In addition, 9 genes previously associated with IBD contained SNPs with significant evidence for replication (P < 1.6 × 10-6): ADCY3, CXCR6, HLA-DRB1 to HLA-DQA1 (genome-wide significance on conditioning), IL12B,PTGER4, and TNC for IBD; IL23R, PTGER4, and SNX20 (in strong linkage disequilibrium with NOD2) for CD; and KCNQ2 (near TNFRSF6B) for UC. Several of these genes, such as TNC (near TNFSF15), CXCR6, and genes associated with IBD at the HLA locus, contained SNPs with unique association patterns with African-specific alleles.

CONCLUSIONS

We performed a genome-wide association study of African Americans with IBD and identified loci associated with UC in only this population; we also replicated IBD, CD, and UC loci identified in European populations. The detection of variants associated with IBD risk in only people of African descent demonstrates the importance of studying the genetics of IBD and other complex diseases in populations beyond those of European ancestry.

Hypoxia promotes colon cancer dissemination through up-regulation of cell migration-inducing protein (CEMIP)

Hypoxic stress drives cancer progression by causing a transcriptional reprogramming. Recently, KIAA1199 was discovered to be a cell-migration inducing protein (renamed CEMIP) that is upregulated in human cancers. However, the mechanism of induction of CEMIP in cancer was hitherto unknown. Here we demonstrate that hypoxia induces CEMIP expression leading to enhanced cell migration. Immunohistochemistry of human colon cancer tissues revealed that CEMIP is upregulated in cancer cells located at the invasive front or in the submucosa. CEMIP localization inversely correlated with E-cadherin expression, which is characteristic of the epithelial-to-mesenchymal transition. Mechanistically, hypoxia-inducible-factor-2α (HIF-2α), but not HIF-1α binds directly to the hypoxia response element within the CEMIP promoter region resulting in increased CEMIP expression. Functional characterization reveals that CEMIP is a downstream effector of HIF-2α-mediated cell migration. Expression of CEMIP was demonstrated to negatively correlate with the expression of Jarid1A, a histone demethylase that removes methyl groups from H3K4me3 (an activation marker for transcription), resulting in altered gene repression. Low oxygen tension inhibits the function of Jarid1A, leading to increased presence of H3K4me3 within the CEMIP promoter. These results provide insight into the upregulation of CEMIP within cancer and can lead to novel treatment strategies targeting this cancer cell migration-promoting gene.