Social and Biological Determinants in Lung Cancer Disparity

Lung cancer remains a leading cause of death in the United States and globally, despite progress in treatment and screening efforts. While mortality rates have decreased in recent years, long-term survival of patients with lung cancer continues to be a challenge. Notably, African American (AA) men experience significant disparities in lung cancer compared to European Americans (EA) in terms of incidence, treatment, and survival. Previous studies have explored factors such as smoking patterns and complex social determinants, including socioeconomic status, personal beliefs, and systemic racism, indicating their role in these disparities. In addition to social factors, emerging evidence points to variations in tumor biology, immunity, and comorbid conditions contributing to racial disparities in this disease. This review emphasizes differences in smoking patterns, screening, and early detection and the intricate interplay of social, biological, and environmental conditions that make African Americans more susceptible to developing lung cancer and experiencing poorer outcomes.

Sustained usage of an app-based clinical-decision making aid for the management of atherosclerotic cardiovascular disease

Background

Complexity of therapies for atherosclerotic cardiovascular disease (ASCVD) risk reduction represents a challenge for clinicians and may lead to poor uptake of these therapies.

Purpose

The goal of this project was to design an easy-to-use, point-of-care tool to risk stratify ASCVD patients and provide individualized guidance for clinicians to incorporate these agents.

Methods

Based on the REACH registry trial and predictive modeling (including 49,689 patients with ASCVD in 44 countries), we designed and implemented an app for secondary risk assessment. Using demographic and comorbidity profiles, this tool was used to calculate an individual's 20-month risk of cardiovascular events and mortality. It also provided graphical comparison to an age-matched control with optimized cardiovascular risk profile to illustrate the modifiable residual risk. The app then utilized the patient's risk profile to provide specific guidance for possible therapeutic interventions SGLT2-inhibitors, GLP1-agonists, PCSK9-inhibitors, Vascular-dose Rivaroxaban, and Icosapent Ethyl. Additionally, it identified individuals who qualified for cardiac rehabilitation or may benefit from smoking cessation interventions, including counselling or pharmacological therapies.

We launched a pilot test of the “Residual Cardiovascular Risk: Assessment and Management Guide” app at a regional cardiac center. 240 referring physicians (including family doctors, emergency physicians, internists, and cardiologists) were invited by email or fax to utilize the app. Feedback was solicited from all users three months into the test period. Following this, no further marketing of the app was performed for all users. Usage data was recorded using Google Analytics over a 12-month period and analyzed in 4-month increments.

Results

From January to December 2021, our app was used to risk stratify 1576 patients. A total of 47 individual users utilized the app over this period. From January to April, the app was used on average 160 times monthly. From May to August, it was used 115 times monthly. From September to December, it was used 118 times monthly. Twenty-four physicians provided feedback; 100% affirmed the functionality, ease of use, and utility of the tool. The app was described as “useful for discussions with patients”, “helpful to optimize patients” and “similar to a mini-cardiology consult”. User suggestions resulted in further improvements to the app, including integration of reports into Electronic Medical Records.

Conclusions

The early success of this app demonstrates a need for simple, accessible, and individualized guidance for management of ASCVD patients to improve uptake of guideline-based medical therapies. This tool demonstrates sustained usage among clinicians, as well as subjective utility in aiding therapeutic decision making. Future clinical research will focus on the ability of this tool to impact physician prescribing patterns and clinical outcomes.

Funding Acknowledgement

Type of funding sources: None.

Abstract 518: Association of CC chemokines with breast cancer disparity

Despite recent advances, breast cancer (BrCa) still affects many women, and the impact is disproportional in African Americans (AA) and European Americans (EA). Addressing socioeconomic and behavioral status has not been enough to reduce disparity, suggesting racial difference in BrCa biology. Our laboratory was the first to show the involvement of CC chemokines in BrCa. In this study, using ONCOMINE, TCGA, bc-GenExMiner, KMplotter, and antibody microarray, we examined the association of CC chemokines in BrCa outcomes and disparity. We show over-expression of CCL5, CCL7, CCL11, CCL17, CCL20, CCL22, and CCL25 in BrCa tissues. High mRNA levels of CCL7, CCL8, CCL17, CCL20, and CCL25 predicted a decrease in overall survival (OS). CCL7 and CCL8 were associated with decreased relapse-free survival. Expression of CCL17 and CCL25 was associated with decreased OS in AA. In EA, CCL8 was associated with decreased OS. Expression of CCL5, CCL7, CLC8, CCL17, CCL20, and CCL25 was highest in TNBC. The expression of CCL11 and CCL22 was associated with HER2 expression. CCL7, CCL8, CCL17, CCL20, and CCL25 were elevated in AAs. Since CCL25 showed a significant association with decreased OS in AA, we examined the expression of CCR9, which is the only receptor for CCL25, and CCR9-mediated signaling in BrCa cell lines derived from AA and EA. Our data show higher expression of CCR9 in AA than EA and distinct molecular cascade in cells derived from AA than EA. Furthermore, higher CCR9 expressing cells showed poor response to Carboplatin upon CCR9 activation. In conclusion, our data suggest the association of distinct CC-chemokines in BrCa progression, OS, and disparate disease outcome in AA compared to EA patients implying CCR9 signaling to be a potential target for improving chemotherapeutic response.

Citation Format: Hina Mir, Briana A. Brock, Rajeev Samant, Shailesh Singh. Association of CC chemokines with breast cancer disparity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 518.

Hydrogen sulphide infiltration downregulates oxidative metabolism and extends postharvest life of banana

Hydrogen sulphide (H₂ S) has emerged as a potential regulator of plant defence against different abiotic stresses. As a climacteric fruit, banana undergoes oxidative stresses shortly after harvest, resulting in faster ripening and senescence. This work examines the effects of vacuum infiltrated H₂ S on ripening inhibition of banana. Banana fruits were vacuum infiltrated with 1 mm H₂ S. Effects on oxidative stress markers, physiological changes, bioactive compounds and antioxidant potentials were examined during storage at 25 °C and 75-80% RH. Results indicate that treated fruits were less affected by oxidative stress, as evident by lower accumulation of ROS (superoxide and peroxide ions), elevated phenols content and antioxidant capacity. The ripening inhibitory effects of H₂ S delayed chlorophyll loss and reduced ethylene and CO₂ production. H₂ S infiltration also reduced MDA accumulation and electrolytic leakage, resulting in longer shelf life. Vacuum infiltration with H₂ S had a protective effect on postharvest banana through overcoming the deleterious effect of ROS and strengthening antioxidant potential. Thus, this method could be promising for enhanced preservation of banana during storage.

CXCR6-CXCL16 Axis Promotes Breast Cancer by Inducing Oncogenic Signaling

Simple Summary

Breast cancer (BrCa) is the second leading cause of cancer-related deaths in American women, and its incidence is on the rise. Insufficient understanding of the mechanisms leading to BrCa limits the effectiveness of the treatment. In this article, we show the importance of a chemokine axis-CXCR6/CXCL16 in supporting BrCa progression. We have delineated BrCa-promoting mechanisms induced by this chemokine axis at the molecular level. This work projects the therapeutic significance of CXCR6/CXCL16 signaling for the treatment of BrCa.

Abstract

Precise mechanisms underlying breast cancer (BrCa) metastasis are undefined, which becomes a challenge for effective treatments. Chemokine signaling instigates the trafficking of cancer cells in addition to leukocytes. This study aimed to ascertain the clinical and biological significance of the CXCR6/CXCL16 signaling axis in the pathobiology of BrCa. Our data show a higher expression of CXCR6 in BrCa cell lines and tissues. Stage-III BrCa tissues express significantly higher CXCR6 compared to stage-II tissues. The ligand, CXCL16, could remain tethered to the cell surface, and, after proteolytic shedding of the ectodomain, the N-terminal fragment is released, converting it to its oncogenic, soluble form. Like CXCR6, N-terminal CXCL16 and ADAM-10 were significantly higher in stage-III than stage-II, but no significant difference was observed in the C-terminal fragment of CXCL16. Further, stimulation of the CXCR6/CXCL16 axis activated Src, FAK, ERK1/2, and PI3K signaling pathways, as per antibody microarray analysis, which also underlie CXCL16-induced F-actin polymerization. The CXCR6/CXCL16 axis induces cytoskeleton rearrangement facilitating migration and invasion and supports BrCa cell survival by activating the PI3K/Akt pathway. This study highlights the significance of the CXCR6/CXCL16 axis and ADAM10 as potential therapeutic targets for advanced-stage BrCa.

Abstract 2428: Emodin enhances efficacy of Oxaliplatin and 5 Fluorouracil in colon cancer by promoting cell cycle arrest

Dysregulation of cellular proliferation and evasion of apoptosis are key contributors to colon cancer (CoCa) development. Chemotherapeutic agents such as 5-Fluorouracil (5FU) and Oxaliplatin (OxT) which are frequently offered to treat CoCa are known to target cells in S and G2 phase of cell cycle. Cancer cells often overcome the effects of 5FU and OxT by deregulating cell cycle in response to these drugs. Therefore, to improve the cytotoxic effect of these chemotherapeutic agents it is important to keep CoCa cells in S and G2 phase. Hence, understanding the molecular mechanisms involved in CoCa cell-cycle progression and chemotherapeutic response could provide strategies for developing effective treatment options. Hence, in this study, we determined the effect of natural agent “Emodin” on CoCa cell-cycle regulation and its ability to increase the efficacy of 5FU and OxT by cell cycle regulation. The effects of Emodin, 5FU, and OxT as a single agent or in combination on CoCa (DLD-1, COLO-201, HCT116 p53WT, and HCT116 p53-/-) cell viability were determined by MTT assays. Combination index of Emodin, 5FU, and OxT were evaluated using Calcusyn. Emodin-induced changes in molecules involved in cell-cycle regulation and proliferation were analyzed via RT-PCR and confirmed by western blot (WB) analysis. Cell-cycle distribution with Emodin treatment alone and in combination with 5FU and OxT were assessed via flow cytometry and WB. Collectively, our data shows that Emodin alone was able to decrease cell survival and induced apoptosis in CoCa cells. Furthermore, cytotoxic ability of 5FU and OxT was increased when combined with Emodin as compared to when these chemotherapeutic drugs were given as single agents Emodin-induced cell-cycle regulation resulted in increased expression of tumor suppressor genes such as p21, p27 and p53, modulated cyclin/cyclin-dependent kinase expression, and induced cell-cycle arrest. Emodin also negatively impacted several signaling pathways associated with cell growth and differentiation. Overall, this study demonstrates that Emodin could be a promising adjuvant to either 5-Fluorouracil or Oxaliplatin in the treatment of CoCa.

Citation Format: Ian T. Saunders, Dexter Ezeagwu, Naresh Kumar, Hina Mir, Shailesh Singh. Emodin enhances efficacy of Oxaliplatin and 5 Fluorouracil in colon cancer by promoting cell cycle arrest [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2428.

Abstract B082: Association of CXCR6/CXCL16 axis in triple-negative breast cancer and racial disparity

Breast cancer (BrCa) is the most common cancer in women worldwide and remains an important global health issue. The American Cancer Society recorded 252,710 new cases of BrCa in the United States in 2017, with 40,610 deaths. Though the incidence of BrCa is higher in Caucasian American (CA), African American (AA) women are often diagnosed with more aggressive TNBC at a younger age. Also, in absence of targeted therapies, cytotoxic chemotherapy remains the backbone of treatment for TNBC. But the median survival of women with advanced TNBC remains dismal. Androgen receptor (AR) has emerged as a potential target for treating TNBC; higher AR expression is a favorable prognostic factor associated with a lower clinical stage, lower histologic grade, and lower mitotic score. Several novel anti-androgenic agents alone or in combination with other agents are currently under investigation. Unfortunately, anti-AR therapies are not as beneficial in AA since AR is often low or missing in AA TNBC. Also, outcome of TNBC in AA is worse than CA, which suggests racial differences in the molecular landscape of TNBC between the two races. Hence, defining the molecular differences in TNBC between racial/ethnic groups is vital in order to effectively reduce the observed disparity in BrCa outcome. There are strong indications of a positive linkage between chemokine, cancer and metastasis. Chemokine receptor CXCR6 and its natural ligand CXCL16 are overexpressed in many cancer cells. We have shown that CXCR6 and CXCL16 axis promotes cancer by cytoskeleton rearrangement and its significance in etiopathogenesis of BrCa is well established. Goal of this study was to establish the association of CXCR6/CXCL16 axis in BrCa disparity using TCGA data and BrCa cell lines. We show overexpression of CXCR6 and CXCL16 in BrCa tissues and cell lines. Expression was higher in AA TNBC compared to CA TNBC cell lines. TCGA data confirms higher CXCR6 and CXCL16 expression in AA compared to CA BrCa and inverse association between androgen receptor (AR) and CXCR6 expression. Low AR expression was found in TNBC expressing high CXCR6 and CXCL16. In addition to this, differential phosphorylation status of signaling molecules down stream of CXCR6 in AA and CA TNBC cells was observed. In conclusion, our work highlights association of CXCR6/CXCL16 in race specific biological differences and emphasizes the potential of CXCR6/CXCL16 as a target to reduce the racial gap in TNBC outcome.

Citation Format: Hina Mir, Jeronay K Thomas, Neeraj Kapur, Anita T Johnson, Shailesh Singh. Association of CXCR6/CXCL16 axis in triple-negative breast cancer and racial disparity [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B082.

Abstract C113: Antibody microarray analysis of signaling networks regulated by the CCR9/CCL25 axis in African American and Caucasian American triple-negative breast cancer

Therapeutic outcome of breast cancer (BrCa) is impeded due to the intratumoral heterogeneity, as well as differences among cancer-bearing individuals. Triple-negative breast cancer (TNBC) is a highly aggressive subtype that disproportionally affects African-American (AA) women. However, the molecular basis of racial disparity in therapeutic response and clinical outcome of TNBC in AA compared to Caucasian American (CA) patients is still obscure. Our group was the first to show the involvement of CCR9 and its natural ligand, CCL25 in cancer progression and therapeutic response, including BrCa. In this study, using proteomic and bioinformatics approach we have quantified the race-specific differences in biologic pathways modulated by the CCR9/CCL25 in TNBC cells. The difference in signaling cascades following CCR9 activation by CCL25 in BrCa cell derived from AA and CA were determined using cancer signaling phospho-protein antibody microarray, which featured 269 antibodies. A heat map was generated to visualize differences in phosphorylation status among cell line derived from AA and CA patients, as well as differences between the cell lines after CCL25 treatment. Graphics of biologic functions and oncogenic signaling networks, which were altered by CCR9/CCL25 axis, were produced using GeneMANIA and Ingenuity Pathway Analysis (IPA) software. Cells derived from AA (MDA-MB-468), show activation/phosphorylation of GSK3α, Elk-1, p70S6K, BCL-2, MEK2, NFkB and STAT3 involved in cell survival and migration. However, cells derived from CA (MDA-MB-231) show activation/phosphorylation of VEGFR2, CTNNB1, FAK, and SHC, suggesting involvement of distinct pathway supporting cell survival following CCR9 activation. Hence, our data suggest that CCR9/CCL25 contributes to the race-specific difference in signaling pathways and these race-specific differences in the biology of TNBC could be the reasons for the disparity in disease and therapeutic outcome.

Citation Format: Jeronay King Thomas, Neeraj Kapur, Hina Mir, Dominique N. Gales, James W. Lillard Jr., Shailesh Singh. Antibody microarray analysis of signaling networks regulated by the CCR9/CCL25 axis in African American and Caucasian American triple-negative breast cancer [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 C113.

Racial Differences in Immunological Landscape Modifiers Contributing to Disparity in Prostate Cancer

Prostate cancer affects African Americans disproportionately by exhibiting greater incidence, rapid disease progression, and higher mortality when compared to their Caucasian counterparts. Additionally, standard treatment interventions do not achieve similar outcome in African Americans compared to Caucasian Americans, indicating differences in host factors contributing to racial disparity. African Americans have allelic variants and hyper-expression of genes that often lead to an immunosuppressive tumor microenvironment, possibly contributing to more aggressive tumors and poorer disease and therapeutic outcomes than Caucasians. In this review, we have discussed race-specific differences in external factors impacting internal milieu, which modify immunological topography as well as contribute to disparity in prostate cancer.

Abstract 1883: Ovarian cancer cells overcome the cytotoxic effect of cisplatin by hyper activating CCR9-mediated signaling in response to cisplatin

Ovarian cancer (OC) has highest mortality rate among the gynecological malignancies. Chemotherapies, in combination with surgery, are standard treatment offered to the patients with advanced OC. Although 80% patients initially respond to platinum-based chemotherapy, clinical responses remain short-lived due to chemoresistance. Most patients experience relapse and 50-60% of them die within 5 years. Therefore, development of novel therapies for OC remains a high priority. Hence, the major focus of this study is to define the biology of CCR9, which is highly expressed in OC in response to platinum drug. Effect of cisplatin on CCR9 expression and impact of CCR9 activation on molecular and cellular changes involved in overcoming the effect of cisplatin was determined by flow cytometric and western blot analyses. Our data show higher expression of CCR9 and CCL25 in OC cells in response to cisplatin treatment. Additionally, our data show higher expression and activation of estrogen receptor-α (ER- α) in OC cell after CCR9 activation. In addition to this, we show CCR9-mediated expression of Smoothened (SMO) known to support stem cell like phenotype by activating Hedgehog signaling and co-expression of CD44 and CCR9 as well as higher CD44 expression in OC cells following CCL25 treatment. CCR9-CCL25 axis promoted epithelial to mesenchymal transition. These observations strongly show an association of CCR9-CCL25 axis in OC pathogenesis, therapeutic resistance, and chemotherapeutic efficacy.

Citation Format: Hina Mir, Neeraj Kapur, Shailesh Singh. Ovarian cancer cells overcome the cytotoxic effect of cisplatin by hyper activating CCR9-mediated signaling in response to cisplatin [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 1883.

Abstract 2494: Emodin inhibits colon cancer by altering BCL-2 family proteins and cell survival pathways

The therapeutic outcome of colon cancer (CoCa) is often compromised due to the development of chemoresistance and toxicities associated with current therapeutics. Hence, identification of less toxic and efficacious agent is needed to treat CoCa. In this study, we tested the effect of natural agent, Emodin (6-methyl-1,3,8-trihydroxyanthraquinone) isolated from Asian plant rhubarb, on CoCa cell death and survival. Effects of Emodin on CoCa (DLD-1 and COLO-201) cell viability and death was determined by MTT and Annexin-V assays, respectively. Apoptosis-specific protein antibody array was used to define the Emodin induced molecular mechanisms involved in cell death vs. survival and results were confirmed by western blot analysis. Mitochondrial membrane potential and the expression/localization of Bcl-2 family protein were assessed via flow cytometry and WB, respectively. Our data show Emodin decreased the viability of CoCa cells and induced apoptotic cell death in a time and dose-dependent manner. Emodin-induced apoptosis resulted in increased death receptor expression, modulated caspase activation, and an imbalance in the Bax/Bcl-2 ratio. Changes in Bcl-2 family protein expression and localization correlated with loss in mitochondrial membrane potential. Emodin also negatively impacted MAPK/JNK, PI3K/AKT, NF-kB and STAT signaling pathways, which are associated with cell growth, differentiation, and Bcl-2 family expression or function. Modulation of cell survival and apoptotic pathways by Emodin and specifically the impact on Bcl-2 projects Emodin significance as promising therapeutic agent for CoCa treatment.

Citation Format: Ian T. Saunders, Neeraj Kapur, Hina Mir, Shailesh Singh. Emodin inhibits colon cancer by altering BCL-2 family proteins and cell survival pathways [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 2494.

Abstract 4237: CC chemokines are differentially expressed in breast cancer and are associated with racial disparity

Despite recent advances in diagnosis and treatment Breast cancer (BrCa) still impacts women’s lives and this impact is disproportional in African Americans (AA) compared to European Americans (EA). Addressing socioeconomic and behavioral status has not reduced the race-specific gap in BrCa outcome, suggesting contribution of biological differences in BrCa disparity. We have previously shown involvement of chemokines in the pathogenesis of BrCa. In this study, we have determined the expression of CC chemokines in BrCa tissues and normal tissues utilizing the ONCOMINE database. Further, we determined clinical parameters associated with the CC chemokines overexpressed in BrCa tissues using The Cancer Genome Atlas (TCGA). Additionally, using Bc-GenExMiner and KMplotter we determined the effects of CC chemokines on reoccurrence, overall and relapse-free survival. Our analysis shows overexpression of CCL5, CCL7, CCL11, CCL17, CCL20, CCL22 and CCL25 mRNA in BrCa tissues compared to normal. Overexpression of CCL21 and CCL22 were significantly correlated with metastatic recurrence. High mRNA levels of CCL7, CCL8, CCL17, CCL20 and CCL25 predicted a decrease in overall survival and CCL7 and CCL8 expression showed a trend in decreased relapse-free survival. Furthermore, overexpression of CCL17 and CCL25 was associated with decreased overall survival in AA whereas in EA, CCL8 was associated with a decrease in overall survival. Interestingly, expression of CCL5, CCL8, CCL17, CCL20 and CCL25 were highest in TNBC tissues. Expression of CCL11 and CCL22 were associated with HER2. In addition to these, there was an association with CC chemokines expression with age in BrCa. Higher CCL11 expression was noted in younger women and CCL8, CCL20, CCL22 and CCL25 expression was higher in older women. Furthermore, CCL25 was significantly elevated and CCL8 was nearly significant in AA tissues when compared to EA. Expression of CCL7, CCL8, and CCL25 were associated with stage. In conclusion, our analysis suggests an association of CC chemokines in BrCa progression, overall survival and observed disparity in disease outcome between AA and EA patients.

Citation Format: Jeronay K. Thomas, Hina Mir, Neeraj Kapur, Shailesh Singh. CC chemokines are differentially expressed in breast cancer and are associated with racial disparity [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 4237.

Abstract 4288: Race specific differences in G-protein decoupling from CCR9 in prostate cancer cells contribute to the differences in docetaxel response

Current treatment approaches have failed to reduce racial disparity in treatment outcome of prostate cancer (PCa) primarily due to the race-specific difference in the biology of PCa. Therefore, identification of race-specific molecular differences is needed to address the disparity in treatment outcome. In this study, we have determined the race-specific differences in CCR9 signaling. Phospho-proteomic profile of key pro-survival molecules following CCL25 treatment in African American (AA) and European American (EA) PCa cells was determined using antibody microarray and validated by western blot analyses. Coupling and decoupling of G-protein(s) with CCR9 in response to CCL25, which determines downstream signaling of CCR9 was ascertained by immunoprecipitation assay (IPA). Cell viability and apoptosis in response to a taxane drug docetaxel (DTX), with/without CCL25 stimulation and CCR9-blockade, were examined using MTT and flow cytometry, respectively. Levels of pro-apoptotic proteins were determined by western blot analyses. Our data show differential G-protein(s) decoupling from CCR9 in AA and EA cells. CCR9-activation dissociated Gαi2/3/Gαq/ Gα13/Gβ1γ7 –proteins in AA cells compared to Gαs/Gβ2γ9 and Gα13/Gαs/G β1/β3γ7 in EA cells, respectively, contribute to different molecular mechanisms supporting cell survival in cell lines derived from two races. Race-specific G-protein signaling in PCa cells, following CCL25 stimulation, is reflected into hyper-activation of molecules involved in PI3K/Akt and MEK/Erk1/2 signaling, which are associated with PCa aggressiveness in AA cells compared to EA counterparts. Further, activation of CCR9-CCL25 axis significantly influences the therapeutic response of PCa cells against DTX, which is highly compromised in AA cells compared to EA cells following CCL25 stimulation. However, this protective effect of CCL25 was abrogated after CCR9 blockade. Inhibition of MEK/Erk1/2 axis significantly improved DTX-induced cell death in AA cells, suggesting the importance of this axis in reducing drug response. Further, stimulation with CCL25, exclusively downregulated cleaved caspase-7, 8 and Bim in response to DTX in AA cells. In all, differential decoupling of G-proteins from CCR9 controls the downstream signaling and therefore determines disparity associated with PCa outcome and offer novel race-specific therapeutic targets for PCa.

Citation Format: Neeraj Kapur, Hina Mir, Shailesh Singh. Race specific differences in G-protein decoupling from CCR9 in prostate cancer cells contribute to the differences in docetaxel response [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 4288.

Emodin inhibits colon cancer by altering BCL-2 family proteins and cell survival pathways

Background

Currently offered therapeutics to treat colon cancer (CoCa) are toxic when given at maximum tolerated dose to achieve optimal clinical response. Hence, less toxic therapeutic intervention is needed to treat CoCa. In this study, we investigated the effect of a natural agent, Emodin, on CoCa.

Methods

Cell viability (MTT) assay was used to determine the effect of Emodin on human CoCa and colon epithelial cells. Flow cytometric analysis was used to determine Emodin induced cell death. Antibody microarray and western blot analyses were used to determine Emodin induced molecular changes involved in cell death. Change in mitochondrial membrane potential in response to Emodin was determined by flow cytometric analysis. Expression and localization of Bcl-2 family proteins were assessed by western blot analysis.

Results

Emodin decreased viability of CoCa cells and induced apoptosis in a time and dose-dependent manner compared to vehicle-treated control without significantly impacting normal colon epithelial cells. Emodin activated caspases, modulated Bcl-2 family of proteins and reduced mitochondrial membrane potential to induce CoCa cell death. Further, changes in Bcl-2 family protein expression and localization correlated with loss in mitochondrial membrane potential. Signaling (MAPK/JNK, PI3K/AKT, NF-κβ and STAT) pathways associated with cell growth, differentiation, and Bcl-2 family expression or function were negatively regulated by Emodin.

Conclusions

Ability of Emodin to impact molecular pathways involved in cell survival and apoptosis highlight the potential of this agent as a new and less toxic alternative for CoCa treatment.

Prostate cancer cells hyper-activate CXCR6 signaling by cleaving CXCL16 to overcome effect of docetaxel

Molecular reprogramming in response to chemotherapeutics leads to poor therapeutic outcomes for prostate cancer (PCa). In this study, we demonstrated that CXCR6-CXCL16 axis promotes DTX resistance and acts as a counter-defense mechanism. After CXCR6 activation, cell death in response to DTX was inhibited, and blocking of CXCR6 potentiated DTX cytotoxicity. Moreover, in response to DTX, PCa cells expressed higher CXCR6, CXCL16, and ADAM-10. Furthermore, ADAM-10-mediated release of CXCL16 hyper-activated CXCR6 signaling in response to DTX. Activation of CXCR6 resulted in increased GSK-3β, NF-κB, ERK1/2 phosphorylation, and survivin expression, which reduce DTX response. Finally, treatment of PCa cells with anti-CXCR6 monoclonal antibody synergistically or additively induced cell death with ∼1.5-4.5 fold reduction in the effective concentration of DTX. In sum, our data imply that co-targeting of CXCR6 would lead to therapeutic enhancement of DTX, leading to better clinical outcomes for PCa patients.

Higher CXCL16 exodomain is associated with aggressive ovarian cancer and promotes the disease by CXCR6 activation and MMP modulation

Ovarian cancer (OvCa) is the leading cause of death from gynecological malignancies. Five-year survival rate of OvCa ranges from 30–92%, depending on the spread of disease at diagnosis. Role of chemokines is well appreciated in cancer, including OvCa. However, their precise role is understudied. Here, we show clinical and biological significance of CXCR6-CXCL16 and ADAM10 in OvCa. Expression of CXCR6 and N-terminal CXCL16 was significantly higher in serous carcinoma tissues compared to endometrioid. OvCa cells (SKOV-3 and OVCAR-3) also showed higher expression of CXCR6 than normal ovarian epithelial cells (IOSE-7576) while CXCL16 was higher in SKOV-3 than IOSE-7576. Furthermore, N-terminal CXCL16 was higher in conditioned media of OvCa cells than IOSE-7576. Compared to OVCAR-3, SKOV-3 cells, which had higher CXCL16, expressed significantly higher transcripts of ADAM10, a protease that cleaves CXCL16. OVCAR-3 cells showed higher CXCR6 specific migration whereas SKOV-3 cells showed more invasion. Difference in invasive potential of these cells was due to modulation of different MMPs after CXCL16 stimulation. Higher CXCR6 expression in serous papillary carcinoma tissues suggests its association with aggressive OvCa. Increased migration-invasion towards CXCL16 implies its role in metastatic spread. Therefore, CXCR6-CXCL16 axis could be used to differentiate between aggressive versus non-aggressive disease and as a target for better prognosis.

Cinnamtannin B-1 inhibits cell survival molecules and induces apoptosis in colon cancer

Colon cancer patients receiving chemotherapy continue to be burdened with therapeutic failure and adverse side effects, yielding a need to develop more effective treatments. The present study investigates Cinnamtannin B-1 (CTB-1) as a potential low-toxicity therapeutic alternative for colon cancer. CTB-1-treated DLD-1, COLO 201 and HCT-116 (WT p53 and p53 null) colon cancer cells and CCD 841 CoN normal colon epithelial cells were assessed for changes in survival using MTT assay. The effects of CTB-1 on cell cycle progression and the apoptosis of colon cancer cells were measured using flow cytometry and/or immunofluorescence. The expression profiles of cell survival molecules, particularly apoptotic proteins, in the colon cancer cells were evaluated following CTB-1 treatment via antibody array, then validated by western blot analysis. Additionally, the potential synergy between CTB-1 and 5-fluorouracil (5-FU), a conventional chemotherapeutic agent used in the treatment of colon cancer, against colon cancer cells was assessed using MTT assay and Calcusyn software. The results revealed that CTB-1 signifi-cantly decreased the survival of the DLD-1, COLO 201 and HCT-116 cells in a time and/or dose-dependent manner, with minimal cytotoxicity to normal colon cells. CTB-1 treatment was shown to induce cell cycle arrest and apoptosis of DLD-1 and COLO 201 cells. Of note, CTB-1 modulated the expression of several cell survival molecules, which tend to be deregulated in colon cancer, including p53, a key transcription factor involved in apoptosis. The downstream regulation of Bcl-2 and Bak expression, as well as cytochrome c release into the cytosol, was also observed following CTB-1 treatment. Furthermore, CTB-1 was shown to significantly enhance the potency of 5-FU via a synergistic drug interaction. This study reveals for the first time, to the best of our knowledge, the ability of CTB-1 to decrease the survival of colon cancer cells through pro-apoptotic mechanisms and display synergy with conventional chemotherapy, demonstrating the potential therapeutic benefit of CTB-1 in colon cancer.

Abstract 2590: Race-specific differential expression of CCL25 and CCR9 in triple-negative breast cancer

Breast cancer (BrCa) is the second leading cause of cancer-related deaths among women. Therapeutic intervention of the disease is impeded due to the heterogeneity contributed by inter- and intra-tumoral diversity, as well as difference among cancer-bearing individuals. Triple-negative breast cancer (TNBC) is a hormone-independent and highly aggressive subtype that disproportionally affects African-American (AA) women. However, the molecular basis of racial disparity in therapeutic response and clinical outcome in AA and Caucasian (CA) patients is still obscure. Our group was the first to show the involvement of CCR9 and its natural ligand, CCL25 in cancer progression and therapeutic response, including breast cancer. In this study, we have shown the association of CCR9 and CCL25 with TNBC. Both CCR9 and CCL25 are highly expressed in TNBC cells (MDA-MB-468 and MDA-MB-231) compared to other BrCa subtypes (MCF-7, MDA-MB-361, SKBr-3). Expression of this receptor-ligand pair was significantly elevated in TNBC cells derived from AA compared to those derived from CA patients. RNA-Seq based transcriptome data obtained from The Cancer Genome Atlas (TCGA) confirmed these results. Further, phospho-proteomic profiling of cancer signaling molecules showed race specific hyper-activation of GSK-3α, GSK-3β and NF-κB in AA derived cells. These molecules are known to provide the survival advantage to cancer cells. These findings, therefore, highlight significance of CCR9 and its association with the disparity in observed in TNBC. Hence, CCR9 targeted approach to address the disparity in the therapeutic outcome of TNBC seems to be promising.

Citation Format: Jeronay King, Neeraj Kapur, Hina Mir, Dominique N. Gales, James W. Lillard, Shailesh Singh. Race-specific differential expression of CCL25 and CCR9 in triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2590.

Abstract 312: Emodin inhibits colon cancer by modulating apoptotic and cell survival signals

Colon cancer remains a formidable health care concern and is the third most common cancer among men and women. Late diagnosis and development of resistance to chemotherapeutic regimens significantly impact overall outcome and survival. Various phytochemicals have been shown to have promising anti-cancer properties. Consequently, such natural agents are emerging as an alternative treatment modality for various cancers, including colon cancer. In this study, we have tested the effect of Emodin, an anthraquinone derivative of rhubarb, on human colon cancer cell lines. Our antibody microarray data and pathway analysis indicated that Emodin induced apoptosis in colon cancer cells by triggering both intrinsic and extrinsic apoptotic pathways. These effects of Emodin were associated with modulation of death receptor expression, changes in mitochondrial membrane integrity, and DNA degradation. Further, western blot analysis confirmed that Emodin significantly increased pro-apoptotic proteins (Bak, Bax, Bad) as well as activated caspase-3 and -8. Additionally, Emodin reduced ERK1/2, NF-κB, and STATs at transcript and protein levels, suggesting it also interferes with cell survival. Hence, the ability of Emodin to induce apoptosis and inhibit cell survival by altering molecular pathways underscore its potential as chemo-preventive as well as -therapeutic agent in combination with conventional chemotherapy.

Citation Format: Ian T. Saunders, Neeraj Kapur, Hina Mir, Shailesh Singh. Emodin inhibits colon cancer by modulating apoptotic and cell survival signals [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 312.

Abstract 5080: ADAM10 promotes breast cancer via CXCL16 constitutive cleavage and CXCR6 signaling

Despite the survival of breast cancer (BrCa) patients, there is still demand to better understand metastasis as the obvious mark for most aggressive breast cancers. Recent evidence highlighted the possible involvement of chemokines and their cognate receptors in BrCa progression and metastasis. Expression and functional role of CXCR6 and CXCL16 have been investigated in different types of cancer. ADAM10 is also known to regulate the metastatic process by the proteolytic shedding of CXCL16 creating a soluble form of CXCL16. High levels of soluble CXCL16 could support tumor progression by promoting migration and invasion of CXCR6 expressing BrCa cells. Here, we demonstrate the significance of CXCR6-CXCL16 axis in BrCa progression. In addition to increased CXCR6 expression, our tissue microarray analysis (TMA) showed increased expression of CXCL16 and ADAM10 in BrCa tissues. BrCa cell lines (MCF-7 and MBA-231) also showed higher expression of ADAM10 as compared to the normal epithelial cells (MCF-10A). Further, these BrCa cells showed increased migration and invasion towards CXCL16 gradient that is due to high expression of CXCR6 and ADAM10. Hence, our findings suggest the clinical and biological significance of ADAM10 and soluble CXCL16 in BrCa progression. We also highlight the potential of ADAM10 and soluble CXCL16 as prognostic markers and new therapeutic target for BrCa.

Citation Format: Dominique N. Gales, Hina Mir, Neeraj Kapur, James W. Lillard, Shailesh Singh. ADAM10 promotes breast cancer via CXCL16 constitutive cleavage and CXCR6 signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5080.

Abstract 1924: Role of CXCL16 and ADAM10 in ovarian cancer pathogenesis

Ovarian cancer is the leading cause of death from gynecological malignancies. The five-year survival rate of ovarian cancer ranges from 30 to 92%, depending on the severity of the disease. Our laboratory has shown the role of chemokines and chemokines receptors in cancer, including ovarian cancer. In this study, we have shown higher expression of CXCR6, which is the only receptor of chemokine CXCL16, in ovarian cancer cell lines and clinical samples. We have tested the biological significance of CXCR6 and soluble CXCL16 (sCXCL16) using ovarian cancer cell lines in vitro. We show higher migratory and invasive potential of high CXCR6 expressing ovarian cancer cell lines in the response of sCXCL16. Migratory and invasive potential in response to sCXCL16 was significantly inhibited when CXCR6 and CXCL16 interaction was blocked using anti-CXCR6 monoclonal antibody. ADAM10 basal mRNA level was higher in cells with high migratory and invasive potential. Similar to cell lines, higher expression of CXCR6 and CXCL16, as well as ADAM10, was observed in tissue, which showed a positive correlation with tumor stage. These results suggest the clinical and biological significance of CXCR6-CXCL16 axis in the pathogenesis of ovarian cancer. Therefore, therapeutics directed to the CXCR6-CXCL16 axis may provide better therapeutic outcome and overall survival.

Citation Format: Hina Mir, Neeraj Kapur, James W. Lillard, Shailesh Singh. Role of CXCL16 and ADAM10 in ovarian cancer pathogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1924.

Abstract 4803: CXCR6-directed therapeutic approach potentiates efficacy of docetaxel in prostate cancer

Development of chemo-resistance negatively impacts therapeutic outcome of advanced prostate cancer (PCa). Molecular mechanism used by cancer cells to overcome therapeutic effect is still undefined. Here, we demonstrate the influence of CXCR6/CXCL16 mediated molecular signals on the efficacy of docetaxel (DTX). Out data showed poor DTX efficacy on PCa cells (LNCaP, PC3, and DU145) after stimulating CXCR6 with soluble CXCL16, while significant improvement in cytotoxic effect of DTX was observed after CXCR6 blockade using anti-CXCR6 monoclonal antibody. Interestingly, CXCR6, CXCL16, and ADAM-10, a metalloproteinase involved in CXCL16 cleavage from PCa cell membranes, were significantly elevated in response to DTX treatment. This was further confirmed on xenograft tumor by immunohistochemistry. Further, phospho-proteomic profiling and western blot analysis showed activation of pro-survival molecules: GSK-3β, NFκB, ERK/1/2, and survivin following soluble CXCL16 treatment. Activation of CXCR6-CXCL16 axis also inhibited expression of the epithelial marker (E-cadherin) while increased expression of mesenchymal markers (β-catenin, α-SMA, vimentin, snail), which highlights the role of CXCR6 in promoting mesenchymal phenotype that is known to have a significant impact on cancer progression and therapeutic outcome. Thus, our study shows that CXCR6-CXCL16 signaling instigates chemotherapeutic resistance by increasing pro-survival signaling and promoting mesenchymal phenotype. Hence, combining CXCR6 blockade with DTX would be a better treatment option for advanced, drug-resistant PCa.

Citation Format: Neeraj Kapur, Hina Mir, Guru Sonpavde, James W. Lillard, Shailesh Singh. CXCR6-directed therapeutic approach potentiates efficacy of docetaxel in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4803.

Phosphorylation hotspot in the C-terminal domain of occludin regulates the dynamics of epithelial junctional complexes

The apical junctional complex (AJC), which includes tight junctions (TJs) and adherens junctions (AJs), determines the epithelial polarity, cell-cell adhesion and permeability barrier. An intriguing characteristic of a TJ is the dynamic nature of its multiprotein complex. Occludin is the most mobile TJ protein, but its significance in TJ dynamics is poorly understood. On the basis of phosphorylation sites, we distinguished a sequence in the C-terminal domain of occludin as a regulatory motif (ORM). Deletion of ORM and expression of a deletion mutant of occludin in renal and intestinal epithelia reduced the mobility of occludin at the TJs. ORM deletion attenuated Ca2+ depletion, osmotic stress and hydrogen peroxide-induced disruption of TJs, AJs and the cytoskeleton. The double point mutations T403A/T404A, but not T403D/T404D, in occludin mimicked the effects of ORM deletion on occludin mobility and AJC disruption by Ca2+ depletion. Both Y398A/Y402A and Y398D/Y402D double point mutations partially blocked AJC disruption. Expression of a deletion mutant of occludin attenuated collective cell migration in the renal and intestinal epithelia. Overall, this study reveals the role of ORM and its phosphorylation in occludin mobility, AJC dynamics and epithelial cell migration.

Abstract 5252: Quercetin inhibits prostate cancer by modulating ROS and key regulators of apoptosis and cell survival

Long latency and indolent nature of prostate cancer (PCa) provides a window of opportunity for preventive interventions using natural and synthetic agents. Hence, the focus of this study was to ascertain the chemopreventive role of Quercetin, a bioflavonoid, commonly used to treat prostatitis. Human PCa cells (LNCaP, DU145 and PC3) were treated with different concentrations of Quercetin and its effect on cell survival and apoptosis was determined by MTT assay. Human PCa cells treated with Quercetin showed significant reduction in cell viability and proliferation compared with untreated controls, which was dose and time dependent. In addition to this our FACS analysis showed higher percentage of apoptotic cells after Quercetin treatment compared to untreated cells. Quercetin induced apoptosis in PCa cells is a cumulative effect of modulation of key apoptotic proteins, changes in mitochondrial membrane potential and ROS production. Our results demonstrate that Quercetin is a potent chemopreventive agent, which may improve outcomes of PCa by inhibiting mechanisms involved in tumor progression.

Citation Format: Ashley B. Ward, Hina Mir, Neeraj Kapur, Guru Sonpavde, Shailesh Singh. Quercetin inhibits prostate cancer by modulating ROS and key regulators of apoptosis and cell survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5252. doi:10.1158/1538-7445.AM2017-5252

Abstract 2328: Race specific hyper-activation of CCR9-mediated survival signals and its impact on efficacy of docetaxel in prostate cancer

Current approaches to treat and manage prostate cancer (PCa) have failed to reduce racial disparity primarily due to undefined molecular mechanism. We have shown higher expression of chemokine receptor-9 in PCa cells and CCR9 expression was higher in PCa cells (MDA-PCa-2b) derived from African American (AA) patient compared to PCa cells derived form European American (EA) patients (LNCaP and PC3). Using antibody microarray we observed hyper activation of survival molecules and down-regulation of apoptotic molecules in AA PCa cells compared to EA PCa cell lines, following CCL25 stimulation. Comparative heat map analysis showed significant increase (~2-3 fold) in phosphorylation of pro-survival proteins in AA cells compared to EA cells treated with CCL25, which was further confirmed by western blot analysis. Furthermore, CCL25 treated PCa cells showed decreased expression of pro-apoptotic proteins (Bim, Bid, Bak), which was significantly abrogated by CCR9 shRNA. This effect was more pronounced in AA cells compared to EA cells. Efficacy of docetaxel (DTX) was higher after CCR9 blockade in presence of CCL25 compared to cells treated with CCL25 without blocking CCR9. Improvement in efficacy of DTX was due to inhibition of cell survival and activation of pro-apoptotic signals following CCR9 blockade. These observations suggest potential involvement of CCR9 mediated molecular pathways in disparity associated with outcome of PCa.

Citation Format: Neeraj Kapur, Hina Mir, Guru Sonpavde, Shailesh Singh. Race specific hyper-activation of CCR9-mediated survival signals and its impact on efficacy of docetaxel in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2328. doi:10.1158/1538-7445.AM2017-2328

Abstract 1263: Andrographolide inhibits prostate cancer by suppressing cytokine involved in promoting epithelial to mesenchymal transition

Mesenchymal phenotypes are responsible for cancer progression and poor therapeutic response. Hence, approaches targeting mesenchymal phenotype or inhibiting epithelial to mesenchymal transition will significantly prevent cancer progression or improve therapeutic outcome. Using in vitro models and molecular approaches we have shown that Andrographolide (AG), a compound isolated from Andrographis paniculata, shows promising effect on mesenchymal cells. It disposes PCa cells towards epithelial phenotype by modulating E-cadherin, ZEB-1, SNAIL and TWIST. In addition to these, significant inhibition in IL-6, which is known to be a poor prognostic maker, was observed in PCa cells treated with AG compared to untreated cells. This reduction in IL-6 could be due to AG induced suppression of SOCS (Suppressor of cytokine signaling) molecules. Therefore, our data underscores the ability of AG to impede cancer growth by impacting EMT and rationalizes its application as a potent therapeutic agent.

Citation Format: Hina Mir, Neeraj Kapur, Guru Sonpavde, Shailesh Singh. Andrographolide inhibits prostate cancer by suppressing cytokine involved in promoting epithelial to mesenchymal transition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1263. doi:10.1158/1538-7445.AM2017-1263

Andrographolide inhibits prostate cancer by targeting cell cycle regulators, CXCR3 and CXCR7 chemokine receptors

Despite state of the art cancer diagnostics and therapies offered in clinic, prostate cancer (PCa) remains the second leading cause of cancer-related deaths. Hence, more robust therapeutic/preventive regimes are required to combat this lethal disease. In the current study, we have tested the efficacy of Andrographolide (AG), a bioactive diterpenoid isolated from Andrographis paniculata, against PCa. This natural agent selectively affects PCa cell viability in a dose and time-dependent manner, without affecting primary prostate epithelial cells. Furthermore, AG showed differential effect on cell cycle phases in LNCaP, C4-2b and PC3 cells compared to retinoblastoma protein (RB(-/-)) and CDKN2A lacking DU-145 cells. G2/M transition was blocked in LNCaP, C4-2b and PC3 after AG treatment whereas DU-145 cells failed to transit G1/S phase. This difference was primarily due to differential activation of cell cycle regulators in these cell lines. Levels of cyclin A2 after AG treatment increased in all PCa cells line. Cyclin B1 levels increased in LNCaP and PC3, decreased in C4-2b and showed no difference in DU-145 cells after AG treatment. AG decreased cyclin E2 levels only in PC3 and DU-145 cells. It also altered Rb, H3, Wee1 and CDC2 phosphorylation in PCa cells. Intriguingly, AG reduced cell viability and the ability of PCa cells to migrate via modulating CXCL11 and CXCR3 and CXCR7 expression. The significant impact of AG on cellular and molecular processes involved in PCa progression suggests its potential use as a therapeutic and/or preventive agent for PCa.

Abstract 1701: CCR6 associates with colon cancer metastasis

Despite established benefits of screening, colon cancer remains a leading cause of cancer death in the U.S. Majority of colon cancer deaths result from metastasis. Effective treatments are not available for advanced disease because molecular mechanisms of initiation and progression of this disease are yet to be defined. Chemokine-chemokine receptor interaction plays an important role in cancer progression. In this study, using colon cancer tissue microarray, we have shown that expression of CCR6 was significantly higher in advanced colon cancer (p<0.0001) with distant and regional lymph node metastasis as compared to non-metastatic and adjacent normal tissues. Expression of CCR6 was further confirmed in cell lines derived from Dukes's type C and type D colon cancer patients using flow cytometric analysis. Like tissues, CCR6 expression was significantly (p<0.0001) higher in colon cancer cell lines compared to normal colon epithelial cells. Furthermore, colon cancer cells showed higher migratory potential toward chemotactic gradient of its only known natural ligand, CCL20. Cell proliferation was also inhibited in presence of CCL20. Significant decrease in E-cadherin, increased expression of vimentin, β-catenin, N-cadherin, α-SMA, SNAIL and ZEB1 was observed following CCL20 treatment. These results suggest the importance of CCR6-CCL20 axis in the etiopathogenesis of colon cancer and highlight its potential as therapeutic target.

Citation Format: Neeraj Kapur, Hina Mir, Clarence E. Clark, Uma Krishnamurti, Derrick J. Beech, James W. Lillard, Shailesh Singh. CCR6 associates with colon cancer metastasis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1701.

Abstract 5254: Andrographolide prevents prostate cancer by targeting CXCR3/CXCR7 and regulators of cell cycle

Despite state of the art cancer diagnostics and therapies offered in clinics, prostate cancer (PCa) remains the second leading cause of cancer-related deaths in men. Hence, more robust therapeutic/preventive regimes are required to combat this lethal disease. In the current study, we have tested the efficacy of andrographolide (AG), a bioactive diterpenoid isolated from Andrographis paniculata, against PCa. This natural agent selectively affects PCa cell viability in a dose and time-dependent manner, without affecting primary prostate epithelial cells. Furthermore, AG showed differential effect on phases of cell cycle in LNCaP, C4-2b and PC3 cell lines compared to retinoblastoma protein (RB-/-) lacking DU-145 cells. This agent blocked the G2/M transition in LNCaP, C4-2b and PC3 whereas DU-145 cells failed to transit G1/S phase. This difference was primarily due to switching of the activation states of cell cycle regulators in these cell lines. AG induced its effect mainly via cyclin A2 and B1 in LNCaP, C4-2b and PC3 cell lines; whereas, cyclin E related regulation was affected in DU-145 cells. Phosphorylation status of Wee1, a nuclear kinase belonging to the Ser/Thr family and CDC2 was also affected by AG. Intriguingly, AG affected cell viability and the ability of PCa cells to migrate via modulating CXCL11 and CXCR3 and CXCR7 expression. The significant impact of AG on cellular and molecular processes involved in PCa progression suggest this agent has potential to be used as a therapeutic and/or preventive modality.

Citation Format: Hina Mir, Neeraj Kapur, Rajesh Singh, Guru Sonpavde, James W. Lillard, Shailesh Singh. Andrographolide prevents prostate cancer by targeting CXCR3/CXCR7 and regulators of cell cycle. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5254.

Chronic ethanol feeding promotes azoxymethane and dextran sulfate sodium-induced colonic tumorigenesis potentially by enhancing mucosal inflammation

Background

Alcohol consumption is one of the major risk factors for colorectal cancer. However, the mechanism involved in this effect of alcohol is unknown.

Methods

We evaluated the effect of chronic ethanol feeding on azoxymethane and dextran sulfate sodium (AOM/DSS)-induced carcinogenesis in mouse colon. Inflammation in colonic mucosa was assessed at a precancerous stage by evaluating mucosal infiltration of neutrophils and macrophages, and analysis of cytokine and chemokine gene expression.

Results

Chronic ethanol feeding significantly increased the number and size of polyps in colon of AOM/DSS treated mice. Confocal microscopic and immunoblot analyses showed a significant elevation of phospho-Smad, VEGF and HIF1α in the colonic mucosa. RT-PCR analysis at a precancerous stage indicated that ethanol significantly increases the expression of cytokines IL-1α, IL-6 and TNFα, and the chemokines CCL5/RANTES, CXCL9/MIG and CXCL10/IP-10 in the colonic mucosa of AOM/DSS treated mice. Confocal microscopy showed that ethanol feeding induces a dramatic elevation of myeloperoxidase, Gr1 and CD68-positive cells in the colonic mucosa of AOM/DSS-treated mice. Ethanol feeding enhanced AOM/DSS-induced suppression of tight junction protein expression and elevated cell proliferation marker, Ki-67 in the colonic epithelium.

Conclusion

This study demonstrates that chronic ethanol feeding promotes colonic tumorigenesis potentially by enhancing inflammation and elevation of proinflammatory cytokines and chemokines.

Occludin deficiency promotes ethanol-induced disruption of colonic epithelial junctions, gut barrier dysfunction and liver damage in mice

BACKGROUND

Disruption of epithelial tight junctions (TJ), gut barrier dysfunction and endotoxemia play crucial role in the pathogenesis of alcoholic tissue injury. Occludin, a transmembrane protein of TJ, is depleted in colon by alcohol. However, it is unknown whether occludin depletion influences alcoholic gut and liver injury.

METHODS

Wild type (WT) and occludin deficient (Ocln(-/-)) mice were fed 1-6% ethanol in Lieber-DeCarli diet. Gut permeability was measured by vascular-to-luminal flux of FITC-inulin. Junctional integrity was analyzed by confocal microscopy. Liver injury was assessed by plasma transaminase, histopathology and triglyceride analyses. The effect of occludin depletion on acetaldehyde-induced TJ disruption was confirmed in Caco-2 cell monolayers.

RESULTS

Ethanol feeding significantly reduced body weight gain in Ocln(-/-) mice. Ethanol increased inulin permeability in colon of both WT and Ocln(-/-) mice, but the effect was 4-fold higher in Ocln(-/-) mice. The gross morphology of colonic mucosa was unaltered, but ethanol disrupted the actin cytoskeleton, induced redistribution of occludin, ZO-1, E-cadherin and β-catenin from the junctions and elevated TLR4, which was more severe in Ocln(-/-) mice. Occludin knockdown significantly enhanced acetaldehyde-induced TJ disruption and barrier dysfunction in Caco-2 cell monolayers. Ethanol significantly increased liver weight and plasma transaminase activity in Ocln(-/-) mice, but not in WT mice. Histological analysis indicated more severe lesions and fat deposition in the liver of ethanol-fed Ocln(-/-) mice. Ethanol-induced elevation of liver triglyceride was also higher in Ocln(-/-) mice.

CONCLUSION

This study indicates that occludin deficiency increases susceptibility to ethanol-induced colonic mucosal barrier dysfunction and liver damage in mice.

Performance of rapid influenza diagnostic tests (QuickVue) for influenza A and B Infection in India

BACKGROUND

Rapid point-of-care (POC) tests provide an economical alternative for rapid diagnosis and treatment of influenza, especially in public health emergency situations.

OBJECTIVES

To test the performance of a rapid influenza diagnostic test, QuickVue (Quidel) as a POC test against a real-time polymerase chain reaction (RT-PCR) assay for detection of influenza A and B in a developing country setting.

STUDY DESIGN

In a prospective observational design, 600 patients with influenza-like illness (ILI) or with severe acute respiratory illness (SARI) who were referred to the Influenza Clinic of a tertiary care hospital in Srinagar, India from September 2012 to April 2013, were enrolled for diagnostic testing for influenza using QuickVue or RT-PCR. All influenza A-positive patients by RT-PCR were further subtyped using primers and probes for A/H1pdm09 and A/H3.

RESULTS

Of the 600 patients, 186 tested positive for influenza A or B by RT-PCR (90 A/H1N1pdm09, 7 A/H3 and 89 influenza B), whereas only 43 tested positive for influenza (influenza A=22 and influenza B=21) by QuickVue. Thus, the sensitivity of the QuickVue was only 23% (95% confidence interval, CI: 17.3-29.8) and specificity was 100% (95% CI: 99.1-100) with a positive predictive value (PPV) of 100% (95% CI 91.8-100) and a negative predictive value (NPV) of 74.3% (95% CI: 70.5-77.9) as compared to RT-PCR.

CONCLUSIONS

The high specificity of QuickVue suggest that this POC test can be a useful tool for patient management or triaging during a public health crisis but a low sensitivity suggests that a negative test result need to be further tested using RT-PCR.

Glutamine supplementation attenuates ethanol-induced disruption of apical junctional complexes in colonic epithelium and ameliorates gut barrier dysfunction and fatty liver in mice

Previous in vitro studies showed that glutamine (Gln) prevents acetaldehyde-induced disruption of tight junctions and adherens junctions in Caco-2 cell monolayers and human colonic mucosa. In the present study, we evaluated the effect of Gln supplementation on ethanol-induced gut barrier dysfunction and liver injury in mice in vivo. Ethanol feeding caused a significant increase in inulin permeability in distal colon. Elevated permeability was associated with a redistribution of tight junction and adherens junction proteins and depletion of detergent-insoluble fractions of these proteins, suggesting that ethanol disrupts apical junctional complexes in colonic epithelium and increases paracellular permeability. Ethanol-induced increase in colonic mucosal permeability and disruption of junctional complexes were most severe in mice fed Gln-free diet. Gln supplementation attenuated ethanol-induced mucosal permeability and disruption of tight junctions and adherens junctions in a dose-dependent manner, indicating the potential role of Gln in nutritional intervention to alcoholic tissue injury. Gln supplementation dose-dependently elevated reduced-protein thiols in colon without affecting the level of oxidized-protein thiols. Ethanol feeding depleted reduced protein thiols and elevated oxidized protein thiols. Ethanol-induced protein thiol oxidation was most severe in mice fed with Gln-free diet and absent in mice fed with Gln-supplemented diet, suggesting that antioxidant effect is one of the likely mechanisms involved in Gln-mediated amelioration of ethanol-induced gut barrier dysfunction. Ethanol feeding elevated plasma transaminase and liver triglyceride, which was accompanied by histopathologic lesions in the liver; ethanol-induced liver damage was attenuated by Gln supplementation. These results indicate that Gln supplementation ameliorates alcohol-induced gut and liver injury.

CCR9/CCL25 expression in non-small cell lung cancer correlates with aggressive disease and mediates key steps of metastasis

Poor clinical outcome of lung cancer (LuCa) is primarily due to lack of knowledge about specific molecules involved in its progression and metastasis. In this study, we for the first time show the clinical and biological significance of CC chemokine receptor-9 (CCR9) in non-small cell lung cancer (NSCLC). Expression of CCR9 and CCL25, the only natural ligand of CCR9, was significantly higher (p < 0.0001) in NSCLC tissues and serum respectively, compared to their respective controls. Interestingly, expression of both CCR9 and CCL25 was significantly higher in adenocarcinomas (ACs) compared to squamous cell carcinomas (SCCs) (p = 0.04, and p < 0.0001). Similar to tissues, AC and SCC cell lines were positive for CCR9 expression. Despite of marginal difference in CCR9 expression, AC cells showed higher migratory and invasive potential in response to CCL25, compared to SCC cells. This differential biological response of AC cells was primarily due to differential expression of matrix metalloproteinases and tissue inhibitor of metalloproteinases under the influence of CCL25. Our results suggest CCR9 as a potential target for developing new treatment modality for NSCLC. Additionally, differential serum CCL25 level in ACs and SCCs, two NSCLC subtypes, suggest its potential as a non-invasive diagnostic/prognostic biomarker.

Abstract 3499: Improving therapeutic efficacy of Docetaxel in breast cancer

Chemotherapy is the preferred choice for treatment of advance breast cancer (BrCa). In most cases, cytotoxic drugs are used at or near a maximum tolerated dose (MTD) to achieve maximum response and eradicate the neoplastic cells, at the same time MTD doses are often toxic and have severe side effects. Lower dose i.e. “optimal biological response modifier dose” (OBRMD) provides potentially beneficial responses, but is not capable of achieving optimal clinical response. Hence, the focus of this study was to achieve the optimal therapeutic outcome of Docetaxel (DTX) at a lower dose by using it in combination with Apigenin (API), a dietary flavonoid present in fruits and vegetables. Effect of DTX and API, either alone or in combination on BrCa cells viability and apoptosis was determined by MTT assay and flow cytometry, respectively. We further investigated the mechanism of enhanced efficacy of DTX using western blot analysis and real time qPCR. Significant decrease in cell viability was observed when cells were treated with low dose DTX in combination with API as compared to either of the agent used individually in MDA-MB-231, MDA-MB-468 and MCF 10A cells. Real time analysis showed that API up regulates pro-apoptotic molecules and down regulates anti-apoptotic molecules when using in combination with DTX. These findings suggest that Apigenin is capable of reducing the effective dose of docetaxel. Hence, this new modality may have better therapeutic outcome with minimal or no toxicity.

Citation Format: Jeronay King, Hina Mir, Neeraj Kapur, Shailesh Singh. Improving therapeutic efficacy of Docetaxel in breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3499. doi:10.1158/1538-7445.AM2015-3499

Abstract 5190: CCR6-mediated molecular mechanisms involved in colon cancer

Colon cancer is one of the leading causes of death due to cancer worldwide. Molecular mechanism of initiation and progression of this disease is yet to be defined. Chemokines and their corresponding receptors have been shown to play important role in progression of many cancers including colon. In this study we have demonstrated that CCR6 is highly expressed in colon cancer and is associated with key steps of metastasis. Cell migration, adhesion and invasion are the key features of cancer progression. This process initiates with the change of less motile epithelial phenotype to a more motile mesenchymal type, the phenomenon known as epithelial-mesenchymal transition (EMT). Interestingly, stimulation of colon cancer cell with CCL20, which is the only natural ligand for CCR6, showed significant decrease in E-cadherin. Furthermore, increased Vimentin, beta-Catenin, N-cadherin, alpha-Smooth Muscle Actin (αSMA) and Snail following CCL20 treatment implicates potential role of CCR6-CCL20 axis in transition to mesenchymal phenotype. Hence, strategies directed to this chemokine-receptor axis may improve therapeutic outcome of colon cancer.

Citation Format: Neeraj Kapur, Hina Mir, Rajesh Singh, Shailesh Singh. CCR6-mediated molecular mechanisms involved in colon cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5190. doi:10.1158/1538-7445.AM2015-5190

Abstract 5362: Andrographolide inhibits prostate cancer by modulating chemokine and cytokines

Treatment options for androgen independent prostate cancer (PCa) are limited. Hence, new treatment strategies are needed to treat/prevent hormone refractory advance disease. Major focus of this study was to develop non-toxic therapeutic/preventive option for PCa. Andrographolide (AG), a bioactive diterpenoid isolated from Andrographis paniculata showed dose and time dependent inhibition of PCa cells (PC3, DU145 and LNCaP). This inhibition in growth was due to selective modulation of chemokines and cytokines required for PCa cell growth and proliferation. Specifically, CXCR3 and CXCR7 expression was reduced after AG treatment. Interestingly, AG inhibited IL-6 expression, which is known to be associated with advance PCa and also highly produced by the aggressive PCa cell compared to less aggressive or normal prostatic epithelial cells. Hence, AG may be offered as a new therapeutic/preventive agent against PCa due to its ability to inhibit key chemokines and cytokines required for PCa progression and supporting hormone refractory PCa.

Citation Format: Hina Mir, Neeraj Kapur, Rajesh Singh, Guru Sonpavde, James W. Lillard, Shailesh Singh. Andrographolide inhibits prostate cancer by modulating chemokine and cytokines. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5362. doi:10.1158/1538-7445.AM2015-5362

Abstract 4107: CCR9/CCL25 mediates epithelial-mesenchymal transition in prostate cancer

Prostate cancer (PCa) is the second leading cause of cancer-related deaths in men, despite the treatment options offered in the clinics. Hence, it is important to further elucidate the molecular mechanisms of PCa progression in order to design more effective treatment strategies. PCa metastasis is a multi-step process that involves epithelial-mesenchymal transition (EMT), during which stationary epithelial cancer cells adopt a mesenchymal phenotype that better suits for survival and motility. We have previously shown that CCR9-expressing PCa cells migrate to and invade distal secondary sites under the influence of chemokine CCL25, its natural ligand. However, the precise molecular mechanisms facilitating EMT in PCa are still not fully understood. Here, we investigated the biological significance of CCR9/CCL25 signaling in inducing EMT in PCa. Modulation of several EMT markers was assessed by western blot and real time qPCR in metastatic PCa cell lines, with or without CCL25 activation. Our results show that following CCL25 stimulation, CCR9 signaling differentially modulates expression of the EMT markers E-cadherin and N-Cadherin in PCa cells, as compared to untreated controls. These findings suggest that the CCR9-CCL25 axis plays an important role in mediating EMT in PCa, thereby increasing the ability of PCa cells to metastasize.

Citation Format: Patrick P. Carriere, Hina Mir, Neeraj Kapur, Rajesh Singh, Guru Sonpavde, James W. Lillard, Shailesh Singh. CCR9/CCL25 mediates epithelial-mesenchymal transition in prostate cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4107. doi:10.1158/1538-7445.AM2015-4107

ALDH2 Deficiency Promotes Ethanol-Induced Gut Barrier Dysfunction and Fatty Liver in Mice

BACKGROUND

Acetaldehyde, the toxic ethanol (EtOH) metabolite, disrupts intestinal epithelial barrier function. Aldehyde dehydrogenase (ALDH) detoxifies acetaldehyde into acetate. Subpopulations of Asians and Native Americans show polymorphism with loss-of-function mutations in ALDH2. We evaluated the effect of ALDH2 deficiency on EtOH-induced disruption of intestinal epithelial tight junctions and adherens junctions, gut barrier dysfunction, and liver injury.

METHODS

Wild-type and ALDH2-deficient mice were fed EtOH (1 to 6%) in Lieber-DeCarli diet for 4 weeks. Gut permeability in vivo was measured by plasma-to-luminal flux of FITC-inulin, tight junction and adherens junction integrity was analyzed by confocal microscopy, and liver injury was assessed by the analysis of plasma transaminase activity, histopathology, and liver triglyceride.

RESULTS

EtOH feeding elevated colonic mucosal acetaldehyde, which was significantly greater in ALDH2-deficient mice. ALDH2(-/-) mice showed a drastic reduction in the EtOH diet intake. Therefore, this study was continued only in wild-type and ALDH2(+/-) mice. EtOH feeding elevated mucosal inulin permeability in distal colon, but not in proximal colon, ileum, or jejunum of wild-type mice. In ALDH2(+/-) mice, EtOH-induced inulin permeability in distal colon was not only higher than that in wild-type mice, but inulin permeability was also elevated in the proximal colon, ileum, and jejunum. Greater inulin permeability in distal colon of ALDH2(+/-) mice was associated with a more severe redistribution of tight junction and adherens junction proteins from the intercellular junctions. In ALDH2(+/-) mice, but not in wild-type mice, EtOH feeding caused a loss of junctional distribution of tight junction and adherens junction proteins in the ileum. Histopathology, plasma transaminases, and liver triglyceride analyses showed that EtOH-induced liver damage was significantly greater in ALDH2(+/-) mice compared to wild-type mice.

CONCLUSIONS

These data demonstrate that ALDH2 deficiency enhances EtOH-induced disruption of intestinal epithelial tight junctions, barrier dysfunction, and liver damage.

Cognitive workload modulation through degraded visual stimuli: a single-trial EEG study

OBJECTIVE

Our experiments explored the effect of visual stimuli degradation on cognitive workload.

APPROACH

We investigated the subjective assessment, event-related potentials (ERPs) as well as electroencephalogram (EEG) as measures of cognitive workload.

MAIN RESULTS

These experiments confirm that degradation of visual stimuli increases cognitive workload as assessed by subjective NASA task load index and confirmed by the observed P300 amplitude attenuation. Furthermore, the single-trial multi-level classification using features extracted from ERPs and EEG is found to be promising. Specifically, the adopted single-trial oscillatory EEG/ERP detection method achieved an average accuracy of 85% for discriminating 4 workload levels. Additionally, we found from the spatial patterns obtained from EEG signals that the frontal parts carry information that can be used for differentiating workload levels.

SIGNIFICANCE

Our results show that visual stimuli can modulate cognitive workload, and the modulation can be measured by the single trial EEG/ERP detection method.

Response of Dictyostelium discoideum to UV-C and involvement of poly (ADP-ribose) polymerase

OBJECTIVES

Radiation and chemical mutagens are direct DNA-damaging agents and ultraviolet (UV) radiation is frequently used in biological studies. Consequent to ozone depletion, UV-C could become a great challenge to living organisms on earth, in the near future. The present study has focused on the role of poly (ADP-ribose) polymerase (PARP) during UV-C-induced growth and developmental changes in Dictyostelium discoideum, a phylogenetically important unicellular eukaryote.

MATERIALS AND METHODS

Dictyostelium discoideum cells were exposed to different doses of UV-C and PARP activity, and effects of its inhibition were studied. Expression of developmentally regulated genes yakA, car1, aca, csA, regA, ctnA, ctnB, gp24, hspD and dsn were analysed using semiquantitative RT-PCR.

RESULTS

We report that the D. discoideum cells displayed PARP activation within 2 min of UV-C irradiation and there was increase in NO levels in a dose-dependent manner. UV-C-irradiated cells had impaired growth, delayed or blocked development and delayed germination compared to control cells. In our previous studies we have shown that inhibition of PARP recovered oxidative stress-induced changes in D. discoideum; however, intriguingly PARP inhibition did not correct all defects as effectively in UV-C-irradiated cells. This possibly was due to interplay with increased NO signalling.

CONCLUSIONS

Our results signify that UV-C and oxidative stress affected growth and development in D. discoideum by different mechanisms; these studies could provide major clues to complex mechanisms of growth and development in higher organisms.