Intermittent Theta-Burst Stimulation Over the Suprahyoid Muscles Motor Cortex Facilitates Increased Degree Centrality in Healthy Subjects

Theta-burst stimulation (TBS), a variant of repetitive transcranial magnetic stimulation (rTMS), can potentially benefit the treatment of swallowing disorders. However, the after-effects of TBS on the swallowing motor cortex remain uncertain. The newly developed graph-based analysis of the centrality approach has been increasingly used to explore brain networks. The purpose of this study was to identify degree centrality (DC) alterations in the brain network after different TBS protocols were performed over the suprahyoid muscles motor cortex in healthy subjects. A total of 40 right-handed healthy subjects (mean age: 23.73 ± 2.57 years, range: 21–30, 20 females) were included in this study and randomly assigned to two groups, including the continuous TBS (cTBS) group and the intermittent TBS (iTBS) group. All of the subjects underwent resting-state functional magnetic resonance imaging (rs-fMRI) scanning before and after TBS implementation. Compared to the baseline, cTBS resulted in increased DC values in the left inferior frontal gyrus (P < 0.01). In the iTBS group, decreased DC was observed in the left cerebellum and left medial frontal gyrus; However, increased DC was observed in several brain areas including the right superior temporal gyrus, right superior frontal gyrus, right postcentral gyri and left paracentral lobule (P < 0.01). These results indicated that cTBS mainly results in increasing DC in the ipsilateral. However, iTBS is capable of facilitating the excitability of the swallowing motor cortex and increasing the connectivity of multiple brain regions, including the bilateral sensorimotor network, and might have therapeutic potential in the treatment of swallowing disorders.

Abstract B102: Factors contributing to precancerous polyp detection in initial screening colonoscopies

Background: The incidence of colorectal cancer is persistently higher in Black/African Americans than other races in the United States. It is less clear whether Black/African Americans are at higher risk for colonic precancerous polyps, which represent an earlier stage in colorectal adenoma-carcinoma progression.

Methods: A retrospective chart review was performed on initial average-risk screening colonoscopies on patients (age 45-75 years) during 2012 at 3 institutions. Multivariable logistic regression models were used to examine the relationship between potential risk factors and the detection of precancerous polyps.

Results: Of the 2,225 initial screening colonoscopies, 1,495 (67.2%) were performed on Black/African Americans and 566 (25.4%) on Caucasian non-Hispanic patients. The mean age of initial colonoscopies was 57.1 y and 56.0 y for Black and Caucasian patients, respectively. Male patients represented 32.0% and 42.8% of the Black and Caucasian patients, respectively. Obese patients represented 41.4% and 31% of Black and Caucasian patients. A higher percentage (30%) of the Black patients were diagnosed with diabetes mellitus compared to Caucasians (11%). Multivariable logistic regression revealed that performance of the colonoscopy by academic gastroenterologists was associated with higher precancerous polyp detection compared to contractual nonacademic gastroenterologists (OR 1.69 95% CI 1.32-2.17, p&lt;0.0001). Because of this observation, a physician feedback program was initiated, and as of 2017 the polyp detection rates at all three institutions reached 25%. In addition, multivariable analysis also identified older age (OR 1.03/year 95% CI 1,01-1,04 p= 0.0006), male sex (OR 1.60 95%CI 1.32-2.00 p&lt;0.0001), current smoking (1.52 95% CI 1.32-2.17 p&lt;0.0001) and diabetes mellitus (OR 1.27 95% CI 0.99-1.63 p = 0.062) as associated with higher precancerous colon polyp detection or adenoma detection rate (ADR). Neither race, ethnicity, BMI, nor insurance was significantly associated with detection rates.

Conclusions: It is imperative that metrics of polyp detection rates be routinely monitored to ensure that all patients have access to high-quality screening colonoscopies. A prospective observational cohort study will help further identify factors associated with precancerous polyp detection, now that variations in operator detection rates have been addressed.

Citation Format: Yakira David, Lorenzo Ottaviano, Jihye Park, Sadat Iqbal, Michelle Likhtshteyn, Samir Kumar, Helen Lyo, Ayanna Lewis, Brandon Lung, Jesse Frye, Li Huang, Ellen Li, Jie Yang, Laura Martello, Shivakumar Vignesh, Joshua Miller, Evan Grossman. Factors contributing to precancerous polyp detection in initial screening colonoscopies [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr B102.

Abstract B059: African American pancreatic cancer microRNAs profile to identify links to drug resistance and tumor progression

Pancreatic cancer is a deadly disease with only 8% of the patients surviving 5 years (1). Recent data published for African Americans (AA) showed that this population has the highest death rate and shortest survival of any racial/ethnic group in the US for most cancers (2). The causes of this disparity are unknown; some of them may be socioeconomic as well as barriers to high-quality cancer prevention, early detection, and treatment information and services. It is clear that there is a gap between AA and Caucasian Americans (CA) concerning the development and death from pancreatic cancer. We hypothesize that there also are molecular differences in the tumors from AA and CA patients that contribute to this disparity. Importantly, The Cancer Genome Atlas (TCGA) numbers for pancreatic cancer reveals that only 7 out of 185 cases of pancreatic cancer are from African American patients. This clearly shows a prominent under-representation of tumor-related genetic information for the AA population. MicroRNAs (miRNAs) are able to regulate dozens of targets, especially those involved in cancer, making them a potential tool to study differences between populations. It is known that patients develop drug resistance against gemcitabine and one factor could be due to differential expression of miRNAs (3). The analysis of potential miRNA differences in AA and CA tumors would be a starting point to study the function(s) and mechanisms to understand the gap between these populations. We analyzed the tumor miRNAs expression of the TCGA 7 AA patients and compared the expression with 10 CA patients from TCGA to understand the main differences in expression between the two sets of samples. Using R studio, we found 26 miRNAs significantly different between CA and AA tumors. Some of them are involved in pathways related with tumor progression, cell invasion and tumor growth. We are interested in miRNAs involved in upregulating drug resistance against gemcitabine such as miR21, miR 155, or miR 196 as well as those miRNAs that dowregulate resistance to treatment like miR148, miR200 or miR34. Importantly, these miRNAs have been defined only in CA pancreatic tumor samples. We are collecting retrospective pancreatic cancer cases at SUNY Downstate Medical Center and Kings County Hospital Center to study the expression of miRNAs using Illumina technology in our AA population in Brooklyn, NY. These tissues will be matched for age, gender, body mass index, and for stage and site of disease to the best of our ability. Adjacent normal tissues will serve as standard controls. We will use CA PDAC cases from TCGA for comparison. This work is in progress. In conclusion, we found in our analysis 26 miRNAs differentially expressed between AA and CA using TCGA data. We expect to see a difference in expression of miRNAs using samples from our patient population. In addition, we are interested to see if our patients have a different expression pattern of miRNAs related to drug resistance and if this could explain the poor response often seen in AA PDAC patients.

Citation Format: Maria Munoz-Sagastibelza, Mohamed Alshal, Sayed Imtiaz, Jenny E. Paredes Sanchez, Mubarak Akadri, Raavi Gupta, Maksim Agaronov, Ellen Li, Jovanny Zabaleta, Laura Martello-Rooney. African American pancreatic cancer microRNAs profile to identify links to drug resistance and tumor progression [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr B059.

SAT0408 UTILITY OF CAROTID ULTRASOUND AND FRAMINGHAM RISK SCORE ON DISCRIMINATING CORONARY ARTERY DISEASE IN PATIENTS WITH PSORIATIC ARTHRITIS (PsA)

Background:

While carotid ultrasound (US) has been advocated for cardiovascular (CV) risk screening in patients with rheumatoid arthritis as various traditional scores underestimate CV risk, whether subclinical carotid atherosclerosis (SCA) is associated with coronary atherosclerosis on coronary computed tomography angiography (CCTA) in patients with psoriatic arthritis (PsA) remains uncertain.

Objectives:

This study aimed to identify carotid US parameters which can discriminate PsA patients with coronary artery disease (CAD) and obstructive CAD (O-CAD), and determine the utility in combination with Framingham Risk Score (FRS).

Methods:

Ninety-one PsA patients (56 males; age: 50±11years, disease duration: 9.4±9.2years) without overt CV diseases were recruited. Carotid intima-media thickness (cIMT), presence of plaque and total plaque area (TPA) were determined by high-resolution US. CAD was defined as the presence of any coronary plaque on CCTA. O-CAD was defined as >50% stenosis of the lumen. FRS <10% indicates low CV risk, 10-19% indicates intermediate risk while ≥20% indicates high risk (1).

Results:

Thirty-five (38%) patient had carotid plaque. Fifty-five (60%) patients had CAD and 9 (10%) patients had O-CAD. 53 (58%), 25 (17%) and 13 (14%) were classified as low, moderate and high CV risk according to the FRS respectively. FRS underestimated the CV risk as only 11/55 (20%) of subjects with CAD were correctly identified as having high CV risk by FRS (Figure 1). Fifteen patients out of 53 (28%) with low CV risk based on FRS were reclassified as high CV risk by the presence of carotid plaque. Nine out of these 15 (60%) had CAD and 1/15 (6.7%) had O-CAD. Concerning the carotid ultrasound parameters, cIMT (mean and maximum) and TPA were increased in both the CAD+ and O-CAD+ group compared to those without CAD or O-CAD (Table 1). Multivariate logistic regression analysis revealed that mean cIMT (OR=1.06, 95% CI:1.01-1.11,p=0.013) was an independent explanatory variables associated with CAD. Meanwhile, mean cIMT (OR=1.06, 95%CI: 1.01-1.11,p=0.013) maximum cIMT (OR=1.06, 95%CI: 1.00-1.13,p=0.043), and TPA (OR=1.55, 95%CI: 1.01-2.36,p=0.043) were independent explanatory variables associated with O-CAD after adjusting for covariates. Based on Receiver Operating Curve (ROC) analysis, an optimal cut off for FRS at 5% and mean cIMT at 0.62mm yield 63% sensitivity and 73% specificity for the presence of CAD (AUC: 0.71,p=0.001).

Table 1.

Relationship between carotid ultrasound parameters and the presence and extent of coronary artery disease on coronary computed tomography angiography.

Coronary artery diseaseNo (n=37)Yes (n=54)pMean carotid IMT, mm0.63±0.120.69±0.10.017Maximum carotid IMT, mm0.77±0.170.84±0.140.040Carotid Plaque, n, %Absence2646.4%3053.6%0.156Presence1131.4%2468.6%Total plaque area, mm20.0[0,6]0.0[0, 10.8]0.059Obstructive coronary artery diseaseNo (n=82)Yes (n=9)pMean carotid IMT, mm0.65±0.120.76±0.070.011Maximum carotid IMT, mm0.80±0.160.93±0.140.020Carotid Plaque, n, %Absence5393.0%47.0%0.235Presence2985.3%514.7%Total plaque area, mm20.0[0, 7.0]6.0[0, 15.3]0.103

IMT-intima media thickness; coronary computed tomography angiography.

Conclusion:

Increased cIMT and TPA were associated with CAD and O-CAD in PsA patients while the presence of carotid plaque alone was insufficient to discriminate patient with or without CAD. A combination of US parameters should be considered for CV risk stratification in patients with PsA.

References:

[1]Ford ES et al.,J Am Coll Cardiol. 2004;43(10):1791-6.

Disclosure of Interests:

Isaac T. Cheng: None declared, Ka Tat Wong: None declared, Edmund Li: None declared, Priscilla C Wong: None declared, Billy Tin Lok Lai: None declared, Cheuk Wan Yim: None declared, Shirley King Yee Ying: None declared, Kitty Yan Kwok: None declared, Martin Li: None declared, Tena K. Li: None declared, Jack Jock Wai Lee: None declared, Alex Pui Wai Lee: None declared, Lai-Shan Tam Grant/research support from: Janssen, Pfizer, Novartis, Speakers bureau: Abbvie, Lilly, Sanofi

Abstract C118: Tumor immune response in colon cancer African American patients and its role in cancer disparities

Introduction: Colorectal cancer (CRC) is the third most common cancer among African Americans (AA) and when compared to Caucasian Americans (CA), they present more advanced CRC disease and lower survival rates. Our previous findings suggest that this may be related to the differential expression in genes linked to cell recruitment and immune response. Therefore, we aimed to investigate the cellular antitumor activity and mutational profile of colon tumors from AAs. We also examined the secretion of cytokines characteristic of immune responses by different effector T helper cells (Th) subsets in AA and CA patients, as well as cell lines, to see if these differences play a role in the health disparities observed between these populations. Lastly, we observed the expression of the Program Death Ligand 1 (PD-L1) in response to the cytokines IL-17A and TNF-α in a microsatellite-unstable (MSI) AA and a microsatellite-stable (MSS) CA colon cancer cell line.

Methods: Using IHC, we evaluated the cell recruitment and activation of T and natural killer cells in AA tumors. For mutational analysis, we utilized the TruSight Tumor 170 RUO kit (Illumina). ELISA assays (RayBiotech) were used to examine the secretion of cytokines linked to Th subsets (Th1, Th2, Th17) and inflammation in plasma from the AA and CA CRC patients, as well as in supernatants from the AA and CA colon cancer cell lines. Western blots were used to observe the expression of PD-L1 in the in vitro models.

Results: ELISAs of plasma of CA and AA patients revealed a differential Th cytokines production patterns between early-stages (I, II) and late-stage (III) disease. The MSI AA cell line showed an increase on PD-L1 protein expression in response to IL-17A and TNF-α with an additive effect when combined in equal concentrations. Lastly, the mutational sequencing allowed us to further investigate the potential alterations that are responsible for the differences that we observed in gene expression between AAs and CAs in our RNA and cytokine expression profiling.

Conclusions: Our results indicate that the immune profiles of AA patients differ from CA in terms of cytokines' production; AAs expressed elevated IL-17A, whereas CA expressed elevated IFN-γ, the latter indicative of Th1 immunity that has a more favorable prognosis. As such, these differences could be used as biomarkers and to guide therapeutic strategy for these populations. The mutational sequencing will help us to elucidate the impaired tumor immune response in AAs with colon cancer when compared to CAs that we observed in terms of cell recruitment and cytokine secretion in our previous findings. Importantly, our data indicate that IL-17A and TNF-α promote the protein production of PD-L1 in an MSI AA cell line, which may result in the impairment of T cells' antitumor activity. Taken together, the differences in the immunologic profiles in AA when compared to CA suggest a deficiency of the appropriate immune defense mechanisms in this population that may contribute to the cancer health disparities among CRC patients.

Citation Format: Jenny E. Paredes, Ping Ji, Jone Garai, Marzia Spagnardi, Maria Munoz-Sagastibelza, Sayed Imtiaz, Gayle Mendez, Mubarak Akadri, Raavi Gupta, Mohamed Alshal, Maksim Agaronov, Henry Talus, Ellen Li, Jovanny Zabaleta, Laura Martello-Rooney, Jennie Williams. Tumor immune response in colon cancer African American patients and its role in cancer disparities [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C118.

Adjuvant chemotherapy for patients with gastric neuroendocrine carcinomas or mixed adenoneuroendocrine carcinomas

BACKGROUND

The aim of this study was to evaluate whether adjuvant chemotherapy is associated with improved survival in patients with resectable gastric neuroendocrine carcinomas (G-NECs) or mixed adenoneuroendocrine carcinomas (G-MANECs).

METHODS

The study included patients with G-NECs or G-MANECs who underwent surgery in one of 21 centres in China between 2004 and 2016. Propensity score matching analysis was used to reduce selection bias, and overall survival (OS) in different treatment groups was estimated by the Kaplan-Meier method.

RESULTS

In total, 804 patients with resectable G-NECs or G-MANECs were included, of whom 490 (60·9 per cent) received adjuvant chemotherapy. After propensity score matching, OS in the chemotherapy group was similar to that in the no-chemotherapy group. Among patients with G-NECs, survival in the fluorouracil (5-FU)-based chemotherapy group and the non-5-FU-based chemotherapy group was similar to that in the no-chemotherapy group. Similarly, etoposide plus cisplatin or irinotecan plus cisplatin was not associated with better OS in patients with G-NECs. Among patients with G-MANECs, OS in the non-5-FU-based chemotherapy group was worse than that in the no-chemotherapy group. Patients with G-MANECs did not have better OS when platinum-based chemotherapy was used.

CONCLUSION

There was no survival benefit in patients who received adjuvant chemotherapy for G-NECs or G-MANECs.

Atmospheric mercury accumulation rate in northeastern China during the past 800 years as recorded by the sediments of Tianchi Crater Lake

An evaluation of the history of anthropogenic mercury (Hg) emissions is needed to quantify total atmospheric Hg emissions since the Industrial Revolution. Thus more long-term records of Hg accumulation rate from natural archives are needed. In the present study, a sediment core from Tianchi Lake, a crater lake in northeastern China, was used to reconstruct atmospheric Hg accumulation rates during the past 800 years. The results show that both Hg concentration and Hg accumulation rate began to increase from 29.5 to 40.2 ng g^-1 and from 1.44 to 2.26 μg m^-2 yr^-1, respectively, at ~ 1750 AD, synchronous with the initiation of the Industrial Revolution. The Hg accumulation rate and Hg concentration increased significantly at ~ 1850 AD, and subsequently, there were two prominent peaks, at ~ 1940 AD and ~ 1980 AD, which are temporally consistent with the Second World War and the peak in commercial usage of Hg, respectively. The Hg accumulation rate and Hg concentration decreased after ~ 1980 AD, possibly because of the decrease in the global Hg background at that time. Differences in regional Hg emissions and atmospheric circulation may be responsible for the different trends in Hg accumulation rate after ~ 1980 AD in the Tibetan Plateau and northeastern China. Our results provide new data for evaluating natural and anthropogenic Hg emissions to the atmosphere in China.

Elevation of long non-coding RNA GAS5 and knockdown of microRNA-21 up-regulate RECK expression to enhance esophageal squamous cell carcinoma cell radio-sensitivity after radiotherapy

OBJECTIVE

Lately, lncRNAs have been proposed to function in the radio-sensitivity of tumor cells, yet the role of lncRNA GAS5 in that of esophageal squamous cell carcinoma (ESCC) has scarcely been studied. This study aims to examine GAS5's effects on ESCC cell radio-sensitivity.

METHODS

GAS5, miR-21 and RECK expression in radiation-sensitive and radiation-resistant ESCC tissues, and TE-1 and TE-1-R cells was determined. TE-1 and TE-1-R cells were treated with pcDNA-GAS5 or miR-21 inhibitors to figure out their roles in ESCC cell proliferation, radio-sensitivity, and apoptosis via gain- and loss-of-function experiments.

RESULTS

We found underexpressed GAS5 and RECK, and overexpressed miR-21 in ESCC. GAS5 elevation and miR-21 inhibition reduced viability and the colony formation ability, and enhanced the apoptosis of ESCC cells under radiation.

CONCLUSION

Our study reveals that GAS5 elevation up-regulates RECK expression by down-regulating miR-21 to increase ESCC cell apoptosis after radiation therapy, thus enhancing cell radio-sensitivity.

Oncogenic KRAS Reduces Expression of FGF21 in Acinar Cells to Promote Pancreatic Tumorigenesis in Mice on a High-Fat Diet

BACKGROUND & AIMS

Obesity is a risk factor for pancreatic cancer. In mice, a high-fat diet (HFD) and expression of oncogenic KRAS lead to development of invasive pancreatic ductal adenocarcinoma (PDAC) by unknown mechanisms. We investigated how oncogenic KRAS regulates the expression of fibroblast growth factor 21, FGF21, a metabolic regulator that prevents obesity, and the effects of recombinant human FGF21 (rhFGF21) on pancreatic tumorigenesis.

METHODS

We performed immunohistochemical analyses of FGF21 levels in human pancreatic tissue arrays, comprising 59 PDAC specimens and 45 nontumor tissues. We also studied mice with tamoxifen-inducible expression of oncogenic KRAS in acinar cells (Kras^G12D/+ mice) and fElas^CreERT mice (controls). Kras^G12D/+ mice were placed on an HFD or regular chow diet (control) and given injections of rhFGF21 or vehicle; pancreata were collected and analyzed by histology, immunoblots, quantitative polymerase chain reaction, and immunohistochemistry. We measured markers of inflammation in the pancreas, liver, and adipose tissue. Activity of RAS was measured based on the amount of bound guanosine triphosphate.

RESULTS

Pancreatic tissues of mice expressed high levels of FGF21 compared with liver tissues. FGF21 and its receptor proteins were expressed by acinar cells. Acinar cells that expressed Kras^G12D/+ had significantly lower expression of Fgf21 messenger RNA compared with acinar cells from control mice, partly due to down-regulation of PPARG expression-a transcription factor that activates Fgf21 transcription. Pancreata from Kras^G12D/+ mice on a control diet and given injections of rhFGF21 had reduced pancreatic inflammation, infiltration by immune cells, and acinar-to-ductal metaplasia compared with mice given injections of vehicle. HFD-fed Kras^G12D/+ mice given injections of vehicle accumulated abdominal fat, developed extensive inflammation, pancreatic cysts, and high-grade pancreatic intraepithelial neoplasias (PanINs); half the mice developed PDAC with liver metastases. HFD-fed Kras^G12D/+ mice given injections of rhFGF21 had reduced accumulation of abdominal fat and pancreatic triglycerides, fewer pancreatic cysts, reduced systemic and pancreatic markers of inflammation, fewer PanINs, and longer survival-only approximately 12% of the mice developed PDACs, and none of the mice had metastases. Pancreata from HFD-fed Kras^G12D/+ mice given injections of rhFGF21 had lower levels of active RAS than from mice given vehicle.

CONCLUSIONS

Normal acinar cells from mice and humans express high levels of FGF21. In mice, acinar expression of oncogenic KRAS significantly reduces FGF21 expression. When these mice are placed on an HFD, they develop extensive inflammation, pancreatic cysts, PanINs, and PDACs, which are reduced by injection of FGF21. FGF21 also reduces the guanosine triphosphate binding capacity of RAS. FGF21 might be used in the prevention or treatment of pancreatic cancer.

Apelin attenuates depressive-like behavior and neuroinflammation in rats co-treated with chronic stress and lipopolysaccharide

Several experimental studies have proved that activation of neuroinflammation pathways may contribute to the development of depression, a neuropsychiatric disorder disease. Our previous studies have shown the antidepressant properties of apelin, but the mechanism was unkown. This study was performed to verify whether the antidepressant effect of apelin was related to its anti-inflammation effect in the central nervous system. To achieve our aim, we selected the co-treatment of chronic stress and LPS to induced an inflammatory process in rats. The effect of this co-treatment was evaluated through the expression of inflammatory markers and glial cell activation. LPS injection co-treated with unpredictable chronic mild stress resulted in the activation of microglial cell and astrocyte, expression of inflammatory markers and depressive behaviors. Treatment with apelin significantly attenuates the deleterious effects in these rats. Our results showed that apelin improved depressive phenotype and decreased the activation of glial cells in stress co-treatment group. The down-regulations of p-NF-κB and p-IKKβ suggested that the effects are possibly mediated by inhibition of the NF-κB-mediated inflammatory response. These findings speculated that intracerebroventricular injection of apelin could be a therapeutic approach for the treatment of depression, and the antidepressant function of apelin may closely associated with its alleviation in neuroinflammation.

Salubrinal enhances eIF2α phosphorylation and improves fertility in a mouse model of Classic Galactosemia

Loss of galactose-1 phosphate uridylyltransferase (GALT) activity in humans results in Classic Galactosemia, and the GalT-deficient (GalT^-/-) mouse mimics the patient condition. GalT^-/- ovaries display elevated endoplasmic reticulum (ER) stress marker, BiP, and downregulated canonical phosphatidylinositol 3-kinase (Pi3k)/protein kinase B (Akt) growth/pro-survival signaling. Numbers of primordial follicles are reduced in the mutants, recapitulating the accelerated ovarian aging seen in human patients. We previously found that oral administration of the compound Salubrinal (an eIF2α phosphatase inhibitor), resulted in reduction of ovarian BiP expression, rescued Pi3k/Akt signaling, and a doubling of primordial follicles in GalT^-/- adults. Here, we further characterized galactosemic stress in GalT^-/- mice versus wild-type (WT) controls, and examined whether Salubrinal treatment improved broader reproductive parameters. We assessed the expression levels of factors of the unfolded protein response (UPR), and found that BiP, phospho-Perk, and phospho-eIF2α were all elevated in GalT^-/- ovaries. However, neither IKK activation (NFκB pathway) nor alternative Xbp1 splicing downstream of ER membrane protein Ire1α activation was induced, suggesting an Xbp1-independent UPR in galactosemic stress. Moreover, Salubrinal treatment significantly increased the number of ovulated eggs in mutant animals after gonadotrophic superovulation. Salubrinal treatment also normalized estrus cycle stage lengths and resulted in significantly larger litter sizes than vehicle-treated mutants. Overall, we show that Salubrinal protects against galactosemia-induced primordial follicle loss in a fashion that includes suppressing the de-phosphorylation of eIF2α, and that intervention in this way significantly improves and extends ovarian function, fertility, and fecundity.

Abstract 152: Gene expression and mutational load in colon tumors from African American patients

Colorectal cancer (CRC) is the third most common cancer among African Americans (AA) and when compared to Caucasian Americans (CA), they present with more advanced disease and lower survival rates. Our previous findings suggest that this may be related to the differential expression of genes linked to cell recruitment and immune response. Therefore, we aimed to investigate if differences in the cellular anti-tumor immune activity in AA and CA patients play a role in the disparate cancer progression observed between these populations. Our approach includes examining gene expression and immune cell recruitment at the tumor site and secretion of cytokines characteristic of effector T helper cells (Th) subsets in plasma. Lastly, we observed the expression of several proteins involved in apoptosis, stress, and drug resistance in response to treatment with 5-FU in two microsatellite unstable (MSI) CRC cell lines, one from an AA and one from a CA patient, and a microsatellite stable (MSS) CA colon cancer cell line.

Methods: We performed whole transcriptome sequencing in colon tumors, utilizing the NextSeq 500/550 High Output Kit v2.5 (Illumina). ELISA assays (RayBiotech) were used to examine the secretion of cytokines linked to Th subsets (Th1, Th2, Th17) and inflammation in plasma. Using IHC we evaluated the cell recruitment and activation of T and Natural Killer cells in colon tumors and by MetaCore we correlated gene expression to immune-oncology pathways. Western blots were used to evaluate the expression of cleaved caspase 3, phospho-JNK and RRM1 in the in-vitro models.

Results: ELISAs of plasma from CA and AA patients revealed a differential Th cytokines production patterns between early stage (I, II) and late stage (III) disease. Our gene expression results indicate that the immune profiles of AA patients differ from CA in the expression of 36 key genes and cytokines related to cellular anti-tumor activity, including FOXP3, Granzyme B and IL-17A, suggestive of more favorable prognosis in the CA tumors. Lastly, the MSI AA cell line showed sensitivity to 5-FU in terms of protein expression when compared to the CA cell lines.

Conclusions: Our gene expression findings demonstrated the differential expression of immunological pathways involved in immune-surveillance, cancer progression and antigen presentation in colon tumors from these two ethnicities. These results were in accordance with the systemic cytokines’ expression patterns observed in plasma and cell recruitment to the tumor sites. Importantly, our data indicates that treatment with 5-FU chemotherapy promotes apoptosis and stress in the MSI AA cell line but fails to produce the same effect in the CA cell lines at the same concentrations. Taken together, the differences in the immunological profiles in AA when compared to CA suggests a deficiency of the appropriate immune defense mechanisms in this population that may contribute to the cancer disparities among CRC patients.

Citation Format: Jenny Paredes, Jone Garai, Ping Ji, Sayed Imtiaz, Marzia Spagnardi, Maria Munoz-Sagastibelza, Mubarak Akadri, Raavi Gupta, Mohamed Alshal, Maksim Agaronov, Henry Talus, Ellen Li, Jennie Williams, Jovanny Zabaleta, Laura Martello-Rooney. Gene expression and mutational load in colon tumors from African American patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 152.

Autoinflammatory disease with focus on NOD2-associated disease in the era of genomic medicine

Systemic autoinflammatory diseases (SAIDs) represent a spectrum of genetically heterogeneous inflammatory disorders. Some SAID-associated genes are located in chromosome 16, including familial Mediterranean fever gene (MEFV) and nucleotide-binding oligomerization domain 2 [NOD2] gene that are linked to Crohn's disease, Blau syndrome, and Yao syndrome. These disorders share overlapping clinical phenotypes, and genotyping is diagnostically helpful and distinctive. Using next generation sequencing in SAIDs, digenic variants or combinations of more genetic variants in different genes can be detected, and they may be related to the MEFV and NOD2 genes. These variants may contribute to heterogeneous phenotypes in an individual, complicating the diagnosis and therapy. An awareness of the clinical significance of the digenic or combined gene variants is important in the era of genomic medicine.

Intermittent Theta-Burst Stimulation Reverses the After-Effects of Contralateral Virtual Lesion on the Suprahyoid Muscle Cortex: Evidence From Dynamic Functional Connectivity Analysis

Contralateral intermittent theta burst stimulation (iTBS) can potentially improve swallowing disorders with unilateral lesion of the swallowing cortex. However, the after-effects of iTBS on brain excitability remain largely unknown. Here, we investigated the alterations of temporal dynamics of inter-regional connectivity induced by iTBS following continuous TBS (cTBS) in the contralateral suprahyoid muscle cortex. A total of 20 right-handed healthy subjects underwent cTBS over the left suprahyoid muscle motor cortex and then immediately afterward, iTBS was applied to the contralateral homologous area. All of the subjects underwent resting-state functional magnetic resonance imaging (Rs-fMRI) pre- and post-TBS implemented on a different day. We compared the static and dynamic functional connectivity (FC) between the post-TBS and the baseline. The whole-cortical time series and a sliding-window correlation approach were used to quantify the dynamic characteristics of FC. Compared with the baseline, for static FC measurement, increased FC was found in the precuneus (BA 19), left fusiform gyrus (BA 37), and right pre/post-central gyrus (BA 4/3), and decreased FC was observed in the posterior cingulate gyrus (PCC) (BA 29) and left inferior parietal lobule (BA 39). However, in the dynamic FC analysis, post-TBS showed reduced FC in the left angular and PCC in the early windows, and in the following windows, increased FC in multiple cortical areas including bilateral pre- and postcentral gyri and paracentral lobule and non-sensorimotor areas including the prefrontal, temporal and occipital gyrus, and brain stem. Our results indicate that iTBS reverses the aftereffects induced by cTBS on the contralateral suprahyoid muscle cortex. Dynamic FC analysis displayed a different pattern of alteration compared with the static FC approach in brain excitability induced by TBS. Our results provide novel evidence for us in understanding the topographical and temporal aftereffects linked to brain excitability induced by different TBS protocols and might be valuable information for their application in the rehabilitation of deglutition.

Confounders in Adenoma Detection at Initial Screening Colonoscopy: A Factor in the Assessment of Racial Disparities as a Risk for Colon Cancer

Background and Aims

The incidence and mortality of colorectal cancer is persistently highest in Black/African-Americans in the United States. While access to care, barriers to screening, and poverty might explain these findings, there is increased interest in examining biological factors that impact the colonic environment. Our group is examining biologic factors that contribute to disparities in development of adenomas prospectively. In preparation for this and to characterize a potential patient population, we conducted a retrospective review of initial screening colonoscopies in a cohort of patients.

Methods

A retrospective review was performed on initial average risk screening colonoscopies on patients (age 45-75 years) during 2012 at three institutions. Descriptive statistics and multivariable logistic regression models were used to examine the relationship between potential risk factors and the detection of adenomas.

Results

Of the 2225 initial screening colonoscopies 1495 (67.2%) were performed on Black/African-Americans and 566 (25.4%) on Caucasians. Multivariable logistic regression revealed that older age, male sex, current smoking and teaching gastroenterologists were associated with higher detection of adenomas and these were less prevalent among Black/African-Americas except for age. Neither race, ethnicity, BMI, diabetes mellitus, HIV nor insurance were associated with adenoma detection.

Conclusion

In this sample, there was no association between race and adenoma detection. While this may be due to a lower prevalence of risk factors for adenomas in this sample, our findings were confounded by a lower detection rate by consultant gastroenterologists at one institution. The study allowed us to rectify the problem and characterize patients for future trials.

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.