Protein biomarkers for radiation injury and testing of medical countermeasure efficacy: promises, pitfalls, and future directions

INTRODUCTION

Radiological/nuclear accidents, hostile military activity, or terrorist strikes have the potential to expose a large number of civilians and military personnel to high doses of radiation resulting in the development of acute radiation syndrome and delayed effects of exposure. Thus, there is an urgent need for sensitive and specific assays to assess the levels of radiation exposure to individuals. Such radiation exposures are expected to alter primary cellular proteomic processes, resulting in multifaceted biological responses.

AREAS COVERED

This article covers the application of proteomics, a promising and fast developing technology based on quantitative and qualitative measurements of protein molecules for possible rapid measurement of radiation exposure levels. Recent advancements in high-resolution chromatography, mass spectrometry, high-throughput, and bioinformatics have resulted in comprehensive (relative quantitation) and precise (absolute quantitation) approaches for the discovery and accuracy of key protein biomarkers of radiation exposure. Such proteome biomarkers might prove useful for assessing radiation exposure levels as well as for extrapolating the pharmaceutical dose of countermeasures for humans based on efficacy data generated using animal models.

EXPERT OPINION

The field of proteomics promises to be a valuable asset in evaluating levels of radiation exposure and characterizing radiation injury biomarkers.

A Dominant-Negative Mutant of ANXA7 Impairs Calcium Signaling and Enhances the Proliferation of Prostate Cancer Cells by Downregulating the IP3 Receptor and the PI3K/mTOR Pathway

Annexin A7/ANXA7 is a calcium-dependent membrane fusion protein with tumor suppressor gene (TSG) properties, which is located on chromosome 10q21 and is thought to function in the regulation of calcium homeostasis and tumorigenesis. However, whether the molecular mechanisms for tumor suppression are also involved in the calcium- and phospholipid-binding properties of ANXA7 remain to be elucidated. We hypothesized that the 4 C-terminal endonexin-fold repeats in ANXA7 (GX(X)GT), which are contained within each of the 4 annexin repeats with 70 amino acids, are responsible for both calcium- and GTP-dependent membrane fusion and the tumor suppressor function. Here, we identified a dominant-negative triple mutant (DNTM/DN-ANXA7J) that dramatically suppressed the ability of ANXA7 to fuse with artificial membranes while also inhibiting tumor cell proliferation and sensitizing cells to cell death. We also found that the [DNTM]ANA7 mutation altered the membrane fusion rate and the ability to bind calcium and phospholipids. In addition, in prostate cancer cells, our data revealed that variations in phosphatidylserine exposure, membrane permeabilization, and cellular apoptosis were associated with differential IP3 receptor expression and PI3K/AKT/mTOR modulation. In conclusion, we discovered a triple mutant of ANXA7, associated with calcium and phospholipid binding, which leads to the loss of several essential functions of ANXA7 pertinent to tumor protection and highlights the importance of the calcium signaling and membrane fusion functions of ANXA7 for preventing tumorigenesis.

MK2 nonenzymatically promotes nuclear translocation of caspase-3 and resultant apoptosis

We have previously identified mitogen-activated protein kinase-activated protein kinase 2 (MK2) is required for caspase-3 nuclear translocation in the execution of apoptosis; however, little is known of the underlying mechanisms. Therefore, we sought to determine the role of kinase and nonkinase functions of MK2 in promoting nuclear translocation of caspase-3. We identified two non-small cell lung cancer cell lines for use in these experiments based on low MK2 expression. Wild-type, enzymatic and cellular localization mutant MK2 constructs were expressed using adenoviral infection. Cell death was evaluated by flow cytometry. In addition, cell lysates were harvested for protein analyses. Phosphorylation of caspase-3 was determined using two-dimensional gel electrophoresis followed by immunoblotting and in vitro kinase assay. Association between MK2 and caspase-3 was evaluated using proximity-based biotin ligation assays and co-immunoprecipitation. Overexpression of MK2 resulted in nuclear translocation of caspase-3 and caspase-3-mediated apoptosis. MK2 directly phosphorylates caspase-3; however, phosphorylation status of caspase-3 or MK2-dependent phosphorylation of caspase-3 did not alter caspase-3 activity. The enzymatic function of MK2 was dispensable in nuclear translocation of caspase-3. MK2 and caspase-3 associated together and a nonenzymatic function of MK2, chaperoned nuclear trafficking, is required for caspase-3-mediated apoptosis. Taken together, our results demonstrate a nonenzymatic role for MK2 in the nuclear translocation of caspase-3. Furthermore, MK2 may function as a molecular switch in regulating the transition between the cytosolic and nuclear functions of caspase-3.

Tumor MK2 transcript levels are associated with improved response to chemotherapy and patient survival in non-small cell lung cancer

Non-small cell lung cancers (NSCLCs) demonstrate intrinsic resistance to cell death, even after chemotherapy. Previous work suggested defective nuclear translocation of active caspase-3 in observed resistance to cell death. We have identified mitogen-activated protein kinase-activated protein kinase 2 (MK2; encoded by the gene MAPKAPK2) is required for caspase-3 nuclear translocation in the execution of apoptosis in endothelial cells. The objective was to determine MK2 expression in NSCLCs and the association between MK2 and clinical outcomes in patients with NSCLC. Clinical and MK2 mRNA data were extracted from two demographically distinct NSCLC clinical cohorts, North American (The Cancer Genome Atlas, TCGA) and East Asian (EA). Tumor responses following first round of chemotherapy were dichotomized as clinical response (complete response, partial response, and stable disease) or progression of disease. Multivariable survival analyses were performed using Cox proportional hazard ratios and Kaplan-Meier curves. NSCLC exhibited lower MK2 expression than SCLC cell lines. In patients, lower tumor MK2 transcript levels were observed in those presenting with late-stage NSCLC. Higher MK2 expression was associated with clinical response following initial chemotherapy and independently associated with improved 2-yr survival in two distinct cohorts, 0.52 (0.28-0.98) and 0.1 (0.01-0.81), TCGA and EA, respectively, even after adjusting for common oncogenic driver mutations. Survival benefit of higher MK2 expression was unique to lung adenocarcinoma when comparing across various cancers. This study implicates MK2 in apoptosis resistance in NSCLC and suggests prognostic value of MK2 transcript levels in patients with lung adenocarcinoma.

Integrated In Silico Analysis of Proteogenomic and Drug Targets for Pancreatic Cancer Survival

Pancreatic cancer remains a major health concern, being among the deadliest forms of cancer with over 80% of the patients presenting with metastatic disease. According to the American Cancer Society, for all stages of pancreatic cancer combined, the 5-year survival rate is less than 10%. Genetic research on pancreatic cancer has generally been focused on familial pancreatic cancer, which is only 10% of all pancreatic cancer patients. This study focuses on finding genes that impact the survival of pancreatic cancer patients which can be used as biomarkers and potential targets to develop personalized treatment options. We used cBioPortal platform using NCI-initiated The Cancer Genome Atlas (TCGA) dataset to find genes that were altered differently in different ethnic groups which can serve as potential biomarkers and analyzed the genes' impact on patient survival. MD Anderson Cell Lines Project (MCLP) and genecards.org were also utilized to identify potential drug candidates that can target the proteins encoded by the genes. The results showed that there are unique genes that are associated with each race category which may influence the survival outcomes of patients, and their potential drug candidates were identified.

Discovery of a Hidden Proinflammatory Signaling Proteome Using a Large-Scale, Targeted Antibody Microarray Platform

Dynamic post-translational processes regulate protein expression in eukaryotic cells. However, the processes are difficult to assess on a proteomic scale because protein levels actually reflect the sum of individual biosynthesis and degradation rates. These rates are presently hidden from the conventional proteomic technologies. We present here a novel and dynamic, antibody microarray-based time-resolved approach to simultaneously measure not only the total protein changes but also the rates of biosynthesis of low abundance proteins in the proteome of lung epithelial cells. In this chapter, we describe the feasibility of this technique by investigating the complete proteomic kinetics of 507 low abundance proteins in cultured cystic fibrosis (CF) lung epithelial cells using ³⁵[S] methionine or ³²[P] and the consequences of repair by gene therapy with [wildtype] CFTR. This novel antibody microarray-based technology identifies relevant, hidden proteins whose regulation by the CF genotype would never have been detected by simple measurements of total proteomic masses.

Stress signaling and STAT1 activation characterize the keratinocytic gene expression pattern in Hidradenitis suppurativa

BACKGROUND

The pathogenetic factors generating the innate immune signal necessary for T cell activation, initiation and chronification of Hidradenitis suppurativa (HS, also known as Acne inversa) are still poorly understood. Emerging evidence suggests that a defective keratinocyte function critically contributes to HS disease development and progression.

OBJECTIVES

To elucidate the role of keratinocytes in HS lesion formation, we compared the transcriptomes of lesional and perilesional epidermis isolated from HS patients by RNA sequencing (RNA Seq).

METHODS

Pairwise-matched lesional and perilesional HS skin samples of five different donors were obtained and epidermal keratinocytes freshly isolated and processed for RNA extraction and RNA seq. Lesionally regulated genes were analyzed by large scale promotor analysis and functional annotation clustering to identify epidermally overrepresented transcription factor binding sites and functionally related gene groups. Results were experimentally validated with independent epidermal isolates of patient-matched lesional and perilesional HS skin employing qRT-PCR, cell culture, immunoblot, and immunostaining.

RESULTS

We show that HS is characterized by a strong epidermal stress state evident by a significant overrepresentation of an AP-1-driven gene signature and a substantial activation of the stress-activated cJun N-terminal kinase (JNK) pathway in lesional epidermis. Additionally, our data reveal a strong induction of STAT1 activation in lesional HS epidermis that likely results from IFNγ production and triggered expression of key inflammatory genes coordinating innate immune activation and the adaptive T cell response in HS.

CONCLUSIONS

Our data implicate a key role of stress signaling and JAK/STAT1 activation in disease progression of HS and suggest interference with JAK/STAT1 signaling as a potentially promising therapeutic approach for HS.

Abstract 5862: Racial disparities in pancreatic cancer: A quantitative proteo-genomic analysis

Pancreatic cancer remains a major health concern, being among the most deadly forms of cancer. It is the seventh most common cancer, yet it is the third leading cause of cancer deaths in the United States. It is estimated that in 2021, 48,220 patients will die from pancreatic cancer. Risk factors for pancreatic cancer include smoking, diabetes, obesity, chronic pancreatitis, and family history. Over 80% of the patients present with metastatic disease. Despite advances in chemotherapy, the average survival remains less than 5 years even after surgery. Genetic research on pancreatic cancer has generally only focused on familial pancreatic cancer, which is only 10% of all pancreatic cancer patients. This study focuses on finding genes that impact the survival of pancreatic cancer patients based on race, with the goal of finding genes that are race specific and can be used as biomarkers and potential targets to develop personalized treatment options. All datasets for pancreatic cancer in cBioPortal were used for this study. The data were then stratified based on race information for the patients. Three (3) racial categories, 1) White 2) African American and Black, and 3) Asian were chosen. Our analysis finds that White, African Americans and Asians have distinct copy number alterations, more specifically amplifications in specific genes, with GATA6, RECQL4, and MIB1 being only altered in White patients, PKD1L1, GARS1, and NEUROD6 only altered in Black & African American patients, and the entire 4p16.3 cytoband of genes (39 in total), only altered in Asian patients. Patients with alterations in these unique genes also had poor survival. Using the Protein Atlas, MD Anderson Cell Lines Project (MCLP) dataset and genecards.org data, we identified potential drug candidates that target the proteins encoded by these genes. Our study clearly demonstrates that race specific genetic alterations exist in pancreatic cancer and provides a foundation for the development of race specific diagnostic/prognostic biomarkers and targeted therapeutic options with better survival outcomes.

Citation Format: Digonto Chatterjee, Jack Hester, Meera Srivastava, Alakesh Bera. Racial disparities in pancreatic cancer: A quantitative proteo-genomic analysis [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 5862.

Abstract 5828: Functional role of long non-coding RNA YTHDF3-AS1 in breast cancer

Breast cancer (BrCa) is the most common form of cancer in women worldwide, impacting nearly 2.1 million women each year. Importantly, current treatment options for metastatic breast cancer fail to elicit an anti-tumor response, leading to a 5-year survival rate below 30%. While most classes of therapy focus on inhibiting or targeting specific proteins, long non-coding RNAs (lncRNAs) offer a unique, relatively untapped, source of potential therapeutic targets. Ongoing experiments are evaluating the regulatory role of the lncRNA YTHDF3-AS1 (ENSG00000270673), which has the potential to develop into a novel therapeutic intervention of BrCa. Through genome-wide analysis, we found that YTHDF3-AS1 expression correlates with essential developmental regulatory genes such as CA3, VPS28, EXOSC4, and TM2D2 and according to pathway analysis is likely linked with the Wnt pathway. Additionally, TCGA data reveals that over 5% of patients with BrCa have an increased copy number of YTHDF3-AS1. Although the role of YTHDF3-AS1 has yet to be explored, YTHDF3 expression was recently shown to be a critical driver of breast cancer metastasis. Of note, YTHDF3-AS1 is upstream of the protein-coding region, but within the promoter region of the YTHDF3 gene. Mechanistically, this allows the lncRNA YTHDF3-AS1 to potentially upregulate the expression of the protein-coding YTHDF3 gene, as two known functions of antisense lncRNAs describe the ability to 1) induce nearby gene expression through binding to the promoter region and 2) stabilize the RNA product of the nearby gene through binding to the 5’UTR. Interestingly, this manner of relationship between antisense (or "divergent") lncRNAs and their protein-coding partner was shown to be highly prevalent in pluripotent stem cells, with the downregulation of both the antisense and protein-coding transcripts following differentiation. Together, our preliminary analysis and previous literature suggest that the lncRNA YTHDF3-AS1 may contribute to the upregulation of YTHDF3, which is a known metastatic promoting protein. Our current study aims to determine the functional role of YTHDF3-AS1 in BrCa oncogenesis, with an emphasis on the mechanistic actions of this lncRNA for the development of future therapeutic approaches.

Citation Format: Alakesh Bera, Surya Radhakrishnan, Eric Russ, Diya Biswas, Madhan Subramanian, Harvey B. Pollard, Hai Hu, Craig D. Shriver, Roopa Biswas, Meera Srivastava. Functional role of long non-coding RNA YTHDF3-AS1 in breast cancer [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 5828.

Circulating Cell-free DNA in Serum as a Marker for the Early Detection of Tumor Recurrence in Breast Cancer Patients

BACKGROUND/AIM

Circulating cell-free DNA (cfDNA) isolated from serum by noninvasive procedures can serve as a potential biomarker for the early detection of many cancers. The aim of this study was to implement a simple, yet effective quantitative method for measuring the cfDNA in serum and to investigate the relationship between cfDNA and the occurrence of recurrence in breast cancer (BrCa) patients.

PATIENTS AND METHODS

A total of 240 cases were selected, which comprised different subtypes of BrCa patients and control individuals. We selected 20 serum samples from patients which showed recurrence after 4-7 years of disease-free survival. SYBR green was used as a reporter molecule to estimate the amount of cfDNA in these serum samples.

RESULTS

A global Wilcoxon analysis was performed to compare the cfDNA abundance between non-recurrent and recurrent patients. The amount of cfDNA was higher in recurrent patients (recurrent vs. non-recurrent ratio=1.3; p=0.03; AUC=0.76) compared to non-recurrent patients. The data between normal/healthy controls and non-recurrent patients indicated no significant differences (n=20 in each group, healthy to non-recurrent ratio=1.03; p=0.20; AUC=0.61).

CONCLUSION

We implemented a straightforward one-step technique to measure the amount of cfDNA in serum, which can translate into a clinical diagnostic tool in the near future. The high levels of cfDNA in the serum of recurrent BrCa patients compared to non-recurrent BrCa patients indicates a possible uncovered role for circulating genetic information, which either contributes to the cancer recurrence phenomenon or at the very least, serves as an identifier for the potential of recurrence.

Abstract P092: A novel approach to target drug-resistance in thyroid cancer by regulating Annexin 7 (ANXA7)/p21 axis

Thyroid cancer is the most common endocrine malignancy in the United States. The survival rate of thyroid cancer patients is high. However, there is a group of patients with poor prognosis due to the development of drug resistance. Differential expression and mutation of the BRAF, Met, and p53 genes have been correlated with the progression and aggressiveness of this cancer, and over 60% of thyroid cancer patients were found to have a V600E mutation in BRAF. ANXA7 is a multifunctional protein that has been found to act as a tumor suppressor in many cancers. In this study, we focused on the expression of ANXA7 in relation to the BRAF mutation and its functional role in regulating thyroid cancer progression, aggressiveness, and drug-sensitivity. High-throughput RNA-seq and protein array studies indicated a lower ANXA7 protein expression linked with thyroid cancer. Additionally, ANXA7 was found to be lower in the thyroid cancer cell lines with the BRAF mutation. To test ANXA7’s role in regulating drug-sensitivity, thyroid cancer cells were treated with different BRAF and MEK inhibitors. Both groups of inhibitor treatment on the thyroid cancer cells resulted in an increase in ANXA7 expression, a decrease in Ph-ERK, and an increase in apoptotic markers. We also found that the cyclin-dependent kinase inhibitor p21 is a novel regulator of BRAF mediated chemoresistance, and elevation of both p21 and ANXA7 through the combination of drugs resulted in a synergistic effect in the apoptotic pathway. Together, these results provide new insights into thyroid malignancy and its drug resistance mechanism involving the ANXA7/p21/BRAF/MAPK pathway. Future translational-based approaches with high-throughput functional screenings are necessary to develop a novel and effective ANXA7-based therapeutic strategy for thyroid cancer.

Citation Format: Surya Radhakrishnan, Alakesh Bera, Narayanan Puthillathu, Nahbuma Gana, Madhan Subramanian, Eric Russ, Anubhuti Paria, Swarnarup Paria, Stephen Rothwell, Harvey B. Pollard, Meera Srivastava. A novel approach to target drug-resistance in thyroid cancer by regulating Annexin 7 (ANXA7)/p21 axis [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P092.

Neuronal inclusions resembling Negri bodies in the thalamus of a red kangaroo (Macropus rufus)

Eosinophilic intracytoplasmic neuronal inclusions resembling Negri bodies, but not associated with lyssaviral infection, were detected in the ventrolateral thalamus of a young-adult, male red kangaroo (Macropus rufus). Similar neuronal inclusions, also with a regional distribution in the brain, have been reported as an incidental, possibly age-related finding in other animal species.

Proteomic Analysis of Inflammatory Biomarkers Associated With Breast Cancer Recurrence

INTRODUCTION

Breast cancer is the most frequent cancer detected for women, and while our ability to treat breast cancer has improved substantially over the years, recurrence remains a major obstacle. Standard screening for new and recurrent breast cancer involves clinical breast imaging. However, there is no clinically approved noninvasive body fluid test for the early detection of recurrent breast cancer. Materials and Method: In this study, we analyzed serum samples from both recurrent and nonrecurrent breast cancer patients by different proteomics methods to identify biomarkers in patients with recurrence of disease.

RESULTS

Comparative data analysis identified several histone deacetylase (HDAC) proteins, which were found at significantly higher levels in the serum of recurrent breast cancer patients: HDAC9 (C-term) (P = 0.0035), HDAC5 (C-term) (P = 0.013), small ubiquitin-like modifier 1 (N-term) (P = 0.017), embryonic stem cell-expressed Ras (inter) (P = 0.018), and HDAC7 (C-term) (P = 0.020). Chronic inflammation plays a critical role in the development of the breast cancer recurrence, and we identified several proinflammatory cytokines that were present at elevated levels only in recurrent breast cancer patient serum.

CONCLUSIONS

Our data indicated that the epigenetic regulation of inflammatory processes plays a critical role in breast cancer recurrence. The identified proteins could lay the groundwork for the development of a serum-based breast cancer recurrence assay.

Liver Function Enzymes are Potential Predictive Markers for Kidney Allograft Dysfunction

Introduction

Biopsy of the allograft is the gold standard for assessing kidney allograft dysfunction. The aim of our pilot study was to identify serum biomarkers that could obviate the need for biopsy.

Materials and Methods

We conducted a study to identify the biomarkers in the serum from different groups of chronic kidney disease (CKD) patients and kidney transplanted patients vs. healthy individuals. The four groups (n=25 in each group) were as follows: 1) Patients with unstable kidney allograft transplants requiring biopsy for cause, 2) Patients with stable kidney allograft transplants, 3) Patients with CKD not on immunosuppressive therapy and, 4) healthy subjects. We measured the activity and level of serum alkaline phosphatase (ALP) and other liver enzymes (alanine transaminase (ALT) and aspartate transaminase (AST)) as potential serum biomarkers in acute allograft dysfunction.

Results

We found that ALP correlated with allograft biopsy findings, liver function, and clinical outcomes and possibly graft survival. Additionally, AST and ALT were higher in patients with graft rejection compared to non-rejected and stable kidney transplants. Moreover, the low Pearson correlations (r- values) between ALP level with age (r=0.179), gender, body mass index (r=0.236), creatinine (r=0.044) or estimated glomerular filtration rate (r=0.048) suggest that ALP may be an independent biomarker which is relatively unaffected by other individual-level variables.

Conclusion

ALP may be a putative biomarker to predict kidney allograft function and rejection. Data also indicated that liver function plays an important role for the overall success of kidney transplantation.

Abstract S01-03: A prediction of prostate cancer deaths spiking by SARS-CoV-2 infection

COVID-19 is a global issue, with over 6.25 million cases in 213 countries and territories on June 1, 2020. Although this virus infects all groups, data indicate that the risk for severe disease and death is much higher in older men, which coincides with the same group of patients at risk for prostate cancer. A recent Italian study investigated the prevalence and severity of COVID-19 in men with prostate cancer. This study indicated that of a total of 4,532 men with COVID-19, from the Veneto region of Italy, 9.5% (n=430) had cancer and out of those around 30% (n=118) had prostate cancer. Data also indicated that male cancer patients had a 1.8-fold increased risk of COVID-19 infection and developed a more severe disease. Interestingly, they observed that the prostate cancer patients (n=4) treated with androgen-deprivation therapy (ADT) were less likely to develop COVID-19, and in those who were infected, the disease was less severe. In this current study, we focused on determining the genetic basis of the higher COVID-19 prevalence and severity in male patients and particularly for prostate cancer patients. Researchers found two genes that are essential for severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2). ACE2 is a SARS-CoV-2 receptor, whereas the serine protease, TMPRSS2, primes the virus for cell entry through cleavage of the viral spike protein (S). The expression of TMPRSS2 is significantly high in normal prostate tissue and is regulated in large part by an androgen response element in the promoter region. Therefore, we decided to investigate the status of these two genes in various tumors from The Cancer Genome Atlas (TCGA) database using the cBioportal platform. We analyzed over 46,000 tumor samples from 176 studies and found that aggressive metastatic prostate cancer, including neuroendocrine prostate cancer (NEPC), has significantly higher amplification (copy number alteration) of the ACE2 and TMPRSS2 genes compared to other cancers. Next, we focused on drugs that could simultaneously target ACE2 or TMPRSS2 and oncogenic pathways and would be beneficial for prostate cancer patients infected with SARS-CoV-2. Although several inhibitors are validated in literature for both ACE2 and TMPRSS2, very limited studies were performed to see the effect on cancer cells. Therefore, we analyzed a cytotoxic effect database of over 130,000 drugs on NCI-60 cell lines with COMPARE algorithm and found two relevant compounds, NSC-148958 (FT-701) and NSC-280594 (triciribine phosphate), which target ACE2 and TMPRSS2, respectively. Computational data are currently validating different prostate cancer cell-lines and their response to these drugs. In summary, our findings provide the premise that men who are at risk for or diagnosed with prostate cancer may be more susceptible to severe infection and death in response to SARS-CoV-2 due to the high expression of ACE2 and TMPRSS2, and triciribine phosphate and FT-701 could be a therapeutic intervention to target co-occurrence of COVID-19 and prostate cancer.

Citation Format: Alakesh Bera, Eric Russ, Digonto Chatterjee, John Karaian, Madhan Subramanian, Sreejato Chatterjee, Surya Radhakrishnan, Michael Eklund, Harvey Pollard, Meera Srivastava. A prediction of prostate cancer deaths spiking by SARS-CoV-2 infection [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2020 Jul 20-22. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(18_Suppl):Abstract nr S01-03.

Abstract 4322: EXOSC4, a novel gene at chromosome 8q24 loci is linked with breast cancer progression and is a prognostic marker for breast cancer survival

The chromosome 8q24 gene contains functional risk loci for multiple cancers, including prostate, colon, and breast. Breast cancer (BrCa) is one of the deadliest diseases among women. Our previous studies using TCGA clinical survival data (Cell. 2018; 173(2):400-416.e11) indicated that several genes are contributed significantly towards the survival of patients with BrCa. Over 75 such most significant genes were screened for further studies in terms of their contribution towards BrCa patient's survival. We found two genes (EXOSC4 and VPS28) with over 10% genetic copy number alterations located at chromosome 8q24 gene loci. Exosome Component 4 (EXOSC4) is located at 8q24.3 and associated with a non-catalytic component of the RNA exosome complex, which has 3' to 5' exoribonuclease activity. It also participates in cellular RNA processing and degradation events. However, the functional role of EXOSC4 towards BrCa progression or survival remains unknown. To understand the molecular basis of an elevated level of EXOSC4 in BrCa propagation, we screened the expression of this protein in different BrCa cell-lines. We also compared the expression of VPS28 within same cell lines. Data indicated that EXOSC4 was co-expressed with VPS28 and Myc, and was also secreted into extracellular space. Therefore, we next evaluated the level of EXOSC4 in patient's serum samples by reverse phase protein array (RPPA). We have well defined and categorized BrCa patients serum samples (n=240) from the Clinical Breast Care Project. The data indicated that the elevated level of EXOSC4 is associated with worse overall survival. In addition, results also showed that the high level of EXOSC4 is linked with breast cancer recurrence.In summary, through multiple modality studies we have confirmed the copy number alteration of EXOSC4 is associated with BrCa patient survival. Once validated, serum level of EXOSC4 could be a predictive biomarker for BrCa progression and survival. Additional experiments are ongoing to evaluate the regulatory role of the EXOSC4 gene which has the potential to develop into a novel therapeutic intervention of BrCa.

Funding Sources: This work was supported by the grant to Dr. Meera Srivastava (DoD, DAMD17-03-1-0107). The work was also supported by the Collaborative Health Initiative Research Program (CHIRP) funding (CHIRP ID# IAA-A-HL-14-007).

Disclaimers: The contents of this publication are the sole responsibility of the author(s) and do not necessarily reflect the views, opinions or policies of The Uniformed Services University of the Health Sciences (USUHS), The Henry M. Jackson Foundation (HJF), the Department of Defense (DoD), the Departments of the Army, Navy, or Air Force. Correspondence: Email: meera.srivastava@usuhs.edu

Citation Format: Alakesh Bera, John Karaian, Madhan Subramanian, Michael Eklund, Eric Russ, Harvey B. Pollard, Hai Hu, Craig D. Shriver, Meera Srivastava. EXOSC4, a novel gene at chromosome 8q24 loci is linked with breast cancer progression and is a prognostic marker for breast cancer survival [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 4322.

Abstract 4846: A quantitative proteo-genomic analysis for targeted therapies in the management of bladder cancer survival

Bladder cancer is the most common type of urothelial carcinoma (UC), and it represents about 5% of all new cancers in the United States. The diagnostics, treatment, and five-year survival rates of this cancer have seen no significant improvements for nearly last three decades. Due to the lack of development of new treatment options, bladder cancer poses a bigger threat than many other cancers. In this current study, we have analyzed over 400 patients' proteo-genomic sequencing and expression data from The Cancer Genome Atlas (TCGA) project using the cBioportal platform. We found two genes, TP53 and CDKN2A, which were significantly altered in the bladder cancer patient samples. The mutations and copy number alteration (CNA) of TP53 were present in more than 50% of patient samples, while CDKN2A was deleted in approximately 40% of patient samples. However, we found that patients with CDKN2A deletion significantly contributed to patient survival compared to TP53 mutational inactivation. Based on this finding, we further analyzed the survival associated genetic alterations in only those patient samples that have the CDK2NA deletion. Analyses indicated that bladder cancer patients with the CDKN2A gene deletion have differential expression of PIK3CA, RPS6KB1, CCND1, and TFRC and worse prognosis. Next, we analyzed protein level expression data using MD Anderson cell line project (MCLP portal) database and found that phospho-RPS6KB1 (p70-S6K_pT389) and CCND1 (Cyclin D1) were the least expressed proteins in bladder cancer cell lines compared to over fifteen different types of cancer cell lines. Additionally, data analyses of The Cancer Therapeutics Response Portal (CTRP) and MCLP database, we found two drugs- hyperforin and CD437 which have the highest Spearman's Rho correlation with CCND1 and RPS6KB1, respectively, with significantly low p-values. Importantly, these drugs sensitize the cell lines that have low CCND1 and RPS6KB1, respectively, and would likely be beneficial for patient survival. Next, we validated our findings in three bladder cancer cell lines, T24, 5637, and HT1376. We monitored the expression of the above proteins in these bladder cancer cell-lines and compared them with other cancer cell lines. Experimental data found a strong agreement with our high throughput cell-line and patient data analysis. Besides, both hyperforin and CD437 drugs exhibit a strong cytotoxic effect on all three bladder cell lines. Furthermore, hyperforin and CD437 were found to increase the expression of CDKN2A in addition to increasing CCND1 and RPS6KB1, respectively. In summary, we characterized four different genes PIK3CA, RPS6KB1, CCND1, and TFRC, which are associated with CDKN2A mediated survival in bladder cancer. Our findings also provide a novel therapeutic approach for bladder cancer patients.

Funding: This work was supported by the DoD grant to Dr. Srivastava (DAMD17-03-1-0107) and by CHIRP funding (CHIRP ID# IAA-A-HL-14-007).

Disclaimers: The contents of this publication are the sole responsibility of the author(s) and do not necessarily reflect the views, opinions or policies of The Uniformed Services University of the Health Sciences (USUHS), The Henry M. Jackson Foundation (HJF), the Department of Defense (DoD), the Departments of the Army, Navy, or Air Force. *Correspondence: meera.srivastava@usuhs.edu OR alakesh.bera.ctr@usuhs.edu.

Citation Format: Sreejato Chatterjee, John Karaian, Madhan Subramanian, Eric Russ, Michael Eklund, Harvey B. Pollard, Meera Srivastava, Alakesh Bera. A quantitative proteo-genomic analysis for targeted therapies in the management of bladder cancer survival [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 4846.

Abstract A073: TGF-beta receptor type-2 expression regulates breast cancer progression and is a prognostic marker for racial disparities

Transforming growth factor β (TGFβ) is one of the most important signaling pathways associated with cellular proliferation, and its dysregulation can lead to tumor development. TGFβ can act as either a tumor suppressor or a tumor promoter depending upon the cellular context and genetic alterations. TGFβ receptor type-2 (TGFβR2) is the ligand-binding receptor, and data shows that the aberration of TGFβR2 is associated with many different cancers including colon, gastric, biliary, pulmonary, and ovarian cancers. In this study, we focused on uncovering the functional role of TGFβR2 in regulating breast cancer (BrCa) progression. First, we analyzed the genomic alterations of TGFβR2 in a sample set from The Cancer Genome Atlas (TCGA, n=1084) on the cBioprotal platform. We focused on obtaining genetic modifications, including mutations and copy number alteration. Data indicated that almost 25% of the patient’s samples having TGFβ amplified copy number; however, only less than one percent patients have amplified copy of TGFβR2 and other TGFβ receptors, within across this sample set. Next, we have screened the level of TGFβR2 protein expression in different BrCa cell-lines. We found that the elevated level of TGFβR2 is associated with the most aggressive triple-negative MDA-MB-231 cells. It is also found that the TGFβR2 is secreted into extracellular space. Therefore, we next evaluated the expression level of TGFβR2 in patient’s serum samples. We have well defined and categorized BrCa patients serum samples (n=240) from the Clinical Breast Care Project led by Walter Reed National Military Medical Center, Bethesda. The differential expression level of TGFβR2 in serum indicated that the elevated level of TGFβR2 is associated with BrCa patients compared with healthy individuals. Furthermore, the serum level of TGFβR2 is higher in the African American patient population when compared to Caucasian patients, and most significant differences were found within Luminal B1 sub-type BrCa cases. To better understand the mechanism of the higher level of TGFβR2 protein expression, in association with aggressiveness, we hypothesized that increased levels of TGFβ ligand are inducing the expression of the receptor (TGFβR2) and eventually stimulating the oncogenic pathway. We have used a series of BrCa cell lines and incubated them with different concentrations of TGFβ ligand. The level of TGFβR2 protein was increased in BrCa cell lines after TGFβ ligand treatment. Increased levels of TGFβ2 ligand induces the expression of the relevant receptor. In summary, we quantified the expression levels of TGFβR2 in patients’ serum samples, which can be used to create a set of stage and race-specific candidate protein biomarkers for BrCa. We also found that the increased level of TGFβ ligand-induced the expression of the TGFβR2 receptor. We can also conclude that TGFβR2 is an important biomarker and possibly plays a role in racial disparities in breast cancer progression.

Citation Format: Alakesh Bera, John Karaian, Harvey B Pollard, Hai Hu, Craig D Shriver, Meera Srivastava. TGF-beta receptor type-2 expression regulates breast cancer progression and is a prognostic marker for racial disparities [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 A073.

A randomized, phase 1, placebo-controlled trial of APG-157 in oral cancer demonstrates systemic absorption and an inhibitory effect on cytokines and tumor-associated microbes

BACKGROUND

Although curcumin's effect on head and neck cancer has been studied in vitro and in vivo, to the authors' knowledge its efficacy is limited by poor systemic absorption from oral administration. APG-157 is a botanical drug containing multiple polyphenols, including curcumin, developed under the US Food and Drug Administration's Botanical Drug Development, that delivers the active components to oromucosal tissues near the tumor target.

METHODS

A double-blind, randomized, placebo-controlled, phase 1 clinical trial was conducted with APG-157 in 13 normal subjects and 12 patients with oral cancer. Two doses, 100 mg or 200 mg, were delivered transorally every hour for 3 hours. Blood and saliva were collected before and 1 hour, 2 hours, 3 hours, and 24 hours after treatment. Electrocardiograms and blood tests did not demonstrate any toxicity.

RESULTS

Treatment with APG-157 resulted in circulating concentrations of curcumin and analogs peaking at 3 hours with reduced IL-1β, IL-6, and IL-8 concentrations in the salivary supernatant fluid of patients with cancer. Salivary microbial flora analysis showed a reduction in Bacteroidetes species in cancer subjects. RNA and immunofluorescence analyses of tumor tissues of a subject demonstrated increased expression of genes associated with differentiation and T-cell recruitment to the tumor microenvironment.

CONCLUSIONS

The results of the current study suggested that APG-157 could serve as a therapeutic drug in combination with immunotherapy.

LAY SUMMARY

Curcumin has been shown to suppress tumor cells because of its antioxidant and anti-inflammatory properties. However, its effectiveness has been limited by poor absorption when delivered orally. Subjects with oral cancer were given oral APG-157, a botanical drug containing multiple polyphenols, including curcumin. Curcumin was found in the blood and in tumor tissues. Inflammatory markers and Bacteroides species were found to be decreased in the saliva, and immune T cells were increased in the tumor tissue. APG-157 is absorbed well, reduces inflammation, and attracts T cells to the tumor, suggesting its potential use in combination with immunotherapy drugs.

Digitoxin Inhibits Epithelial-to-Mesenchymal-Transition in Hereditary Castration Resistant Prostate Cancer

Castration Resistant Prostate Cancer (CRPC) is thought to be driven by a collaborative mechanism between TNFα/NFκB and TGFβ signaling, leading to inflammation, Epithelial-to-Mesenchymal-Transition (EMT), and metastasis. Initially, TGFβ is a tumor suppressor, but in advanced metastatic disease it switches to being a tumor promoter. TGFBR2 may play a critical role in this collaboration, as its expression is driven by NFκB and it is the primary receptor for TGFβ. We have previously reported that the cardenolide drug digitoxin blocks TNFα/NFκB-driven proinflammatory signaling. We therefore hypothesized that digitoxin might break the collaborative process between NFκB and TGFβ by also inhibiting expression of TGFBR2. We therefore tested whether TGFβ-driven EMT and resulting metastases would be suppressed. Here we show, in vitro, that digitoxin inhibits NFκB-driven TGFBR2 expression, as well as Vimentin, while elevating E-cadherin expression. Digitoxin also significantly reduces HSPB1 mRNA and the HSPB1/RBFOX2 mRNA ratio in PC3 cells. In vivo, in a syngeneic, immune competent rat model of metastatic CRPC, we show that digitoxin also suppresses Tgfbr2 expression, as well as expression of other genes classically driven by NFκB, and of multiple EMT genes associated with metastasis. Concurrently, digitoxin suppresses tumor growth and metastasis in these animals, and prolongs survival. Gross tumor recurrence following tumor resection also appears prevented in ca 30% of cases. While the existence of a collaboration between NFκB and TGFβ to drive EMT and metastasis has previously been appreciated, we show here, for the first time, that chronic, low concentrations of digitoxin are able to block CRPC tumor progression, EMT and the ensuing metastatic disease.

Serum Biomarkers for Racial Disparities in Breast Cancer Progression

African American (AA) women are often diagnosed with more aggressive breast cancers and have worse survival outcomes than their Caucasian American (CA) counterparts. However, a comprehensive understanding of this disparity remains unclear. In this study, we attempted to identify the race-specific non-invasive protein biomarkers that may particularly benefit interventions aimed at reducing the risk of recurrence and metastasis in breast cancers (BrCa). Our technical strategy has been to discover candidate protein biomarkers in patient sera using a high throughput antibody microarray platform. A total of 240 subjects were selected, composed of controls and all immunohistochemistry-based subtypes of breast cancer cases, subdivided by pre- and post-menopausal status and by race. A global Wilcoxon analysis comparing no-cancer controls and cancer patients identified Pyk2, SAPK/JNK, and phosphatase and tensin homolog as present in higher concentrations in cancer patient serum. A paired t-test revealed that c-kit and Rb are significantly over-represented in AA cancer serum when compared to CA cancer serum. Interestingly, VEGFR2, a protein linked to BrCa metastasis and poor prognosis, was significantly over-represented in AA cancer serum compared to AA controls; however, this was not found in CA cancer serum compared to CA controls, suggesting a possible explanation for the higher incidence of aggressive BrCa in AA versus CA patients. Through examining race-specific differences in the protein landscape of BrCa patient serum, the identified proteins could lay the groundwork for the development of an all-inclusive "liquid mammogram test."

Functional imaging of tumor vasculature using iodine and gadolinium-based nanoparticle contrast agents: a comparison of spectral micro-CT using energy integrating and photon counting detectors

Advances in computed tomography (CT) hardware have propelled the development of novel CT contrast agents. In particular, the spectral capabilities of x-ray CT can facilitate simultaneous imaging of multiple contrast agents. This approach is particularly useful for functional imaging of solid tumors by simultaneous visualization of multiple targets or architectural features that govern cancer development and progression. Nanoparticles are a promising platform for contrast agent development. While several novel imaging moieties based on high atomic number elements are being explored, iodine (I) and gadolinium (Gd) are particularly attractive because of their existing approval for clinical use. In this work, we investigate the in vivo discrimination of I and Gd nanoparticle contrast agents using both dual energy micro-CT with energy integrating detectors (DE-EID) and photon counting detector (PCD)-based spectral micro-CT. Simulations and phantom experiments were performed using varying concentrations of I and Gd to determine the imaging performance with optimized acquisition parameters. Quantitative spectral micro-CT imaging using liposomal-iodine (Lip-I) and liposomal-Gd (Lip-Gd) nanoparticle contrast agents was performed in sarcoma bearing mice for anatomical and functional imaging of tumor vasculature. Iterative reconstruction provided high sensitivity to detect and discriminate relatively low I and Gd concentrations. According to the Rose criterion applied to the experimental results, the detectability limits for I and Gd were approximately 2.5 mg ml^-1 for both DE-EID CT and PCD micro-CT, even if the radiation dose was approximately 3.8 times lower with PCD micro-CT. The material concentration maps confirmed expected biodistributions of contrast agents in the blood, liver, spleen and kidneys. The PCD provided lower background signal and better simultaneous visualization of tumor vasculature and intratumoral distribution patterns of nanoparticle contrast agent compared to DE-EID decompositions. Preclinical spectral CT systems such as this could be useful for functional characterization of solid tumors, simultaneous quantitative imaging of multiple targets and for identifying clinically-relevant applications that benefit from the use of spectral imaging. Additionally, it could aid in the development nanoparticles that show promise in the developing field of cancer theranostics (therapy and diagnostics) by measuring vascular tumor biomarkers such as fractional blood volume and the delivery of liposomal chemotherapeutics.

Abstract P4-01-26: Circulating cell-free DNA in serum as a marker for the early detection of tumor recurrence in breast cancer patients

Background: Quantitative estimation of circulating cell-free DNA (cfDNA) isolated from serum by noninvasive procedures can serve as a potential biomarker for the early detection of many cancers. However, a simple, straightforward technique is unavailable to estimate the cfDNA in clinical labs. Moreover, the prognostic value of cfDNA in patients with breast cancer (BrCa) is currently under debate. The aim of this study was to develop a simple yet effective quantitative method for measuring the cfDNA in serum and to eventually investigate the relationship between cfDNA and the occurrence of recurrence in BrCa patients.

Methods: A total of 240 patient cases (n=240) were selected and are comprised of different subtypes of breast cancer patients and control individuals. We selected 21 serum samples from patients which showed recurrence after 4-7 years of disease-free survival. For the compare studies, each of the recurrent and non-recurrent serum samples was incubated with the SYBR Green I (2 μM). A standard graph was also made with known DNA concentration to calculate the amount of cfDNA in these recurrent and non-recurrent serum samples. Additionally, a comparative study was also performed with the serum of patients with non-recurrent BrCa versus healthy patients.

Results: We develop a simple fluorescent based measuring technique which can easily estimate the cfDNA in one step. SYBR Green binds to DNA, and as a result, the fluorescence of SYBR Green increases substantially. Global Wilcoxon analyses were performed to compare the cfDNA amount between non-recurrent and recurrent patients. There is a significant difference in fluorescent intensities between recurrent patients' samples versus non-recurrent patients which are directly proportional to the cfDNA levels. The amount of cfDNA is higher in recurrent patient (ratio is 1.3 up; p= 0.03; AUC=0.76) compared to similar non-recurrent patients. While we compared the fluorescence data between normal/healthy patients versus non-recurrent is turned out as non-significant (healthy to non-recurrent ratio = 1.03; p= 0.20, AUC=0.61).

Conclusion: In this current study, we developed a straightforward one-step technique to measure the amount of cfDNA in serum, which can easily translate into a clinical diagnostic tool. To the best of our knowledge, this is the first report which demonstrates serum cfDNA as an early detection marker for recurrent breast cancer patients. The relatively high level of cfDNA in the serum of recurrent breast cancer patients compared to non-recurrent breast cancer patients indicates an uncovered circulating genetic information which triggers the cancer recurrence pathway to relapse cancer in the near future.

Citation Format: Bera A, Eidelman O, Russ E, Landa A, Karaian J, Eklund M, Hu H, Pollard HB, Shriver CD, Srivastava M. Circulating cell-free DNA in serum as a marker for the early detection of tumor recurrence in breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-01-26.

Tissue microarray analysis delineate potential prognostic role of Annexin A7 in prostate cancer progression

Background

Annexin A7 (ANXA7) is a member of the multifunctional calcium or phospholipid-binding annexin gene family. While low levels of ANXA7 are associated with aggressive types of cancer, the clinical impact of ANXA7 in prostate cancer remains unclear. Tissue microarrays (TMA) have revealed several new molecular markers in human tumors. Herein, we have identified the prognostic impact of ANXA7 in a prostate cancer using a tissue microarray containing 637 different specimens.

Methods

The patients were diagnosed with prostate cancer and long-term follow-up information on progression (median 5.3 years), tumor-specific and overall survival data (median 5.9 years) were available. Expression of Ki67, Bcl-2, p53, CD-10 (neutral endopeptidase), syndecan-1 (CD-138) and ANXA7 were analyzed by immunohistochemistry.

Results

A bimodal distribution of ANXA7 was observed. Tumors expressing either high or no ANXA7 were found to be associated with poor prognosis. However, ANXA7 at an optimal level, in between high and no ANXA7 expression, had a better prognosis. This correlated with low Ki67, Bcl-2, p53 and high syndecan-1 which are known predictors of early recurrence. At Gleason grade 3, ANXA7 is an independent predictor of poor overall survival with a p-value of 0.003. Neoadjuvant hormonal therapy, which is known to be associated with overexpression of Bcl-2 and inhibition of Ki67 LI and CD-10, was found to be associated with under-expression of ANXA7.

Conclusions

The results of this TMA study identified ANXA7 as a new prognostic factor and indicates a bimodal correlation to tumor progression.

High ANXA7 Potentiates Eucalyptol Toxicity in Hormone-refractory Prostate Cancer

BACKGROUND/AIM

Our studies showed that ANXA7 is a novel tumor suppressor gene that is lost in various aggressive forms of prostate cancer. However, little is known about the role of ANXA7 in the anticancer drug treatment towards different cancers.

MATERIALS AND METHODS

The expression of ANXA7 was measured in the 60 cancer cell lines of the NCI-60 ADS project and correlated with the enhanced sensitivity to over 30,000 natural and synthetic compounds.

RESULTS

Eucalyptol showed a high positive correlation with ANXA7 expression and castration-resistant prostate cancer cell death occurred very effectively in response to the combination of eucalyptol and overexpressed wt-ANXA7 than either agent alone. The synergistic effects of ANXA7 and eucalyptol resulted in concordant changes in gene expression profiles particularly of Ras family members, MDM4, NF-ĸB and VEGF.

CONCLUSION

Overexpression of ANXA7 enhances eucalyptol cytotoxicity in prostate cancer cell lines.

Abstract 2797: Synthesis and evaluation of derivatives of selective inhibitor ERGi USU, for ERG-positive prostate cancer cells

Introduction and objectives:

Prostate cancer is the most frequently diagnosed non-skin malignancy and third leading cause of cancer related deaths among men in the United States. Currently, early detected organ confined prostate cancer (CaP) is managed by active surveillance, surgery or radiation therapy. A significant subset of patients (20% to 40%) experience biochemical recurrence after definitive treatment. New AR axis inhibitors (abiraterone and enzalutamide) are leading to significant improvements in treatment of late stages of CaP. However, sustained therapeutic response remains a challenge due to high mutation load at late stages of the disease. Thus, there is an urgent need for evaluating new therapeutic targets for early stages of CaP. ERG oncoprotein and ERG dependent pathways are promising targets for early stage cancer therapy. Previously identified ERGi-USU from our laboratory, demonstrated remarkable exclusivity for inhibiting ERG protein and cell growth of ERG positive tumor cells in both in vitro and in vivo. With comprehensive structure activity relationship (SAR) studies, we generated new derivatives with substituents around the core structure to further enhance efficacy.

Methods: Cell growth inhibition of small molecules was validated with established prostate cancer cell lines and normal prostate/endothelial derived cell panel. Preferential species-specific binding of ERGi-USU to human RIOK2 was confirmed by tryptophan fluorescence quenching assay.

Result: Based on SAR of the parental ERGi-USU, 90 new ERGi-USU derivatives were designed using structure based predictions. Of these, 37 compounds were prioritized for chemical synthesis and biological evaluations using assays that were developed earlier in our laboratory. We completed primary screen of these compounds in cell culture models. Among these one compound (ERGi-USU-6) inhibited the growth of ERG positive prostate cancer cells with remarkable improvement IC50=70 nM. This value is in the range of current FDA approved drugs. The result also confirmed the high selectivity of ERGi-USU-6 for the inhibition of ERG positive cancer cell growth. Further, mechanistic studies revealed ERGi-USU binding and disruption of the atypical RIOK2 kinase basic function of ribosome biogenesis, due to initiation of ribosomal stress, cell cycle arrest and apoptosis in ERG positive VCaP cells. We also demonstarte preferential binding of ERGi-USU to human RIOK2 by tryptophan fluorescence quenching assay.

Conclusion: The ERGi-USU-6, derivative of ERGi-USU showed improved efficacy in selectively inhibiting the growth of ERG positive cancer cells. Since ERG is a prostate cancer causing oncogene that affects approximately one third of CaP patients world-wide, early therapeutic intervention with ERGi-USU derivatives may prevent the development of late stage disease in prostate cancer patients.

Citation Format: Charles Peter Xavier, Ahmed A. Mohamed, Nishat Seraj, Vineet Kumar, Taduru Sreenath, Inger L. Rosner, Gyorgy Petrovics, Meera Srivastava, Clifton L. Dalgard, Sanjay V. Malhotra, Nicole A. LaRonde, Albert Dobi, Shiv Srivastava. Synthesis and evaluation of derivatives of selective inhibitor ERGi USU, for ERG-positive prostate cancer cells [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 2797.

Identification of a Small Molecule That Selectively Inhibits ERG-Positive Cancer Cell Growth

Oncogenic activation of the ETS-related gene (ERG) by recurrent gene fusions (predominantly TMPRSS2-ERG) is one of the most validated and prevalent genomic alterations present in early stages of prostate cancer. In this study, we screened small-molecule libraries for inhibition of ERG protein in TMPRSS2-ERG harboring VCaP prostate cancer cells using an In-Cell Western Assay with the highly specific ERG-MAb (9FY). Among a subset of promising candidates, 1-[2-Thiazolylazo]-2-naphthol (NSC139021, hereafter ERGi-USU) was identified and further characterized. ERGi-USU selectively inhibited growth of ERG-positive cancer cell lines with minimal effect on normal prostate or endothelial cells or ERG-negative tumor cell lines. Combination of ERGi-USU with enzalutamide showed additive effects in inhibiting growth of VCaP cells. A screen of kinases revealed that ERGi-USU directly bound the ribosomal biogenesis regulator atypical kinase RIOK2 and induced ribosomal stress signature. In vivo, ERGi-USU treatment inhibited growth of ERG-positive VCaP tumor xenografts with no apparent toxicity. Structure-activity-based derivatives of ERGi-USU recapitulated the ERG-selective activity of the parental compound. Taken together, ERGi-USU acts as a highly selective inhibitor for the growth of ERG-positive cancer cells and has potential for further development of ERG-targeted therapy of prostate cancer and other malignancies.Significance: A highly selective small-molecule inhibitor of ERG, a critical driver of early stages of prostate cancer, will be imperative for prostate cancer therapy. Cancer Res; 78(13); 3659-71. ©2018 AACR.

Cyclin E and FGF8 are downstream cell growth regulators in distinct tumor suppressor effects of ANXA7 in hormone-resistant cancer cells of breast versus prostate origin

Tumor suppressor function of Annexin-A7 (ANXA7) was demonstrated by cancer-prone phenotype in Anxa7(+/-) mice and ANXA7 profiling in human cancers including prostate and breast. Consistent with its more evident in vivo tumor suppressor role in prostate cancer, wild-type(wt)-ANXA7 in vitro induced similar G2-arrests, but reduced survival more drastically in prostate cancer cells compared to breast cancer cells (DU145 versus MDA-MB-231 and -435). In all three hormone-resistant cancer cell lines, wt-ANXA7 abolished the expression of the oncogenic low-molecular weight (LMW) cyclin E which was for the first time encountered in prostate cancer cells. Dominant-negative nMMM-ANXA7 (which lacks phosphatidylserine liposome aggregation properties) failed to abrogate LMW-cyclin E and simultaneously induced fibroblast growth factor 8 (FGF8) in DU145 that was consistent with the continuing cell cycle progression and reduced cell death. Adenoviral vector alone induced FGF8 in MDA-MB-231/435 cell lines, but not in DU145 cells. Our data indicated that the LMW-Cyclin E expressions in breast cancer and prostate cancer cell-lines were differentially regulated by wild-type and dominant-negative ANXA7 isoforms, demonstrating a different survival mechanism utilized by breast cancer cells. Conventional tumor suppressor p53 failed to completely abolish FGF8 and LMW-cyclin E in breast cancer cells, which were eventually translated into their survival. Thus, ANXA7 tumor suppression could modulate FGF8 and cyclin E expression, and control implying more specific associations with the annexin properties of ANXA7 in prostate tumorigenesis.

ZnxFe3−xO4 (0.01 ≤ x ≤ 0.8) nanoparticles for controlled magnetic hyperthermia application

Stable temperature was attained during magnetic hyperthermia by Zn substituted magnetite nanoparticles.

Abstract 1183: Structure-activity studies and biological evaluations of ERGi-USU, a highly selective inhibitor for ERG-positive prostate cancer cells

Introduction and objectives: While new prostate cancer (CaP) treatments (Abiraterone and Enzalutamide) have improved survival in castration-resistant prostate cancer (CRPC), their benefits are short-lived and drug resistance develops likely due to numerous adaptive mutations. Therefore it is a critical to develop effective novel inhibitors to target other signaling pathways that promote or contribute to prostate tumorigenesis. Accumulating evidence has established the androgen regulated TMPRSS2-ERG fusion as a common oncogenic driver that contributes to the early development and progression of over half of CaP. Therefore, ERG oncoprotein and ERG dependent pathways are promising targets for CaP therapy in early stages when cancer is most responsive to treatment. We previously identified a small molecule inhibitor, ERGi-USU, which selectively inhibits ERG protein and cell growth in ERG positive tumor cell lines and mouse xenograft models. In an effort to further develop ERGi-USU with enhanced efficacy we performed detailed structure-activity relationship (SAR) evaluation of ERGi-USU core structure and developed new derivatives.

Methods: Based on SAR of the core structure of ERGi-USU, 48 new derivatives were designed and synthesized by substitutions with alkyl, alkoxy, cycloalkyl, heterocycloalkyl, aryl, heteroaryl or hydroxyl groups. The new ERGi-USU derivatives were evaluated for inhibition of cell growth and ERG protein levels in the TMPRSS2-ERG fusion harboring CaP cell line, VCaP. Four of these compounds have been selected for evaluation of ERG selectivity by defining IC50 in ERG positive malignant cells (VCaP, KG1, MOLT-4 and COLO320), ERG negative CaP cell line (LNCaP) or ERG positive normal primary endothelium-derived cells (HUVEC).

Result: Like parental compound, four new ERGi-USU derivatives exhibited inhibition of cell growth and ERG protein levels in ERG positive VCaP, KG1, MOLT-4 and COLO320 cell lines, with no or minimal effects on LNCaP and HUVEC cells. One of the new derivatives (ERGi-USU#6) showed increased efficacy for cell growth inhibition (IC50=0.074µM) compared to the parental ERGi-USU (IC50=0.200µM). Other three new compounds showed similar IC50 as the ERGi-USU.

Conclusion: Comprehensive evaluation of ERGi-USU derivatives along with parental compound has continued to underscore selective inhibition of ERG positive tumor cells by these small molecules.

Citation Format: Ahmed A. Mohamed, Charles P. Xavier, Gauthaman Sukumar, Samuel D. Banister, Vineet Kumar, Shyh-Han Tan, Shilpa Katta, Lakshmi Ravindranath, Muhammad Jamal, Taduru Sreenath, David G. McLeod, Gyorgy Petrovics, Albert Dobi, Meera Srivastava, Sanjay Malhotra, Clifton Dalgard, Shiv Srivastava. Structure-activity studies and biological evaluations of ERGi-USU, a highly selective inhibitor for ERG-positive prostate cancer cells [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 1183. doi:10.1158/1538-7445.AM2017-1183

Synergistic Activity with NOTCH Inhibition and Androgen Ablation in ERG-Positive Prostate Cancer Cells

The oncogenic activation of the ETS-related gene (ERG) due to gene fusions is present in over half of prostate cancers in Western countries. Because of its high incidence and oncogenic role, ERG and components of ERG network have emerged as potential drug targets for prostate cancer. Utilizing gene expression datasets, from matched normal and prostate tumor epithelial cells, an association of NOTCH transcription factors with ERG expression status was identified, confirming that NOTCH factors are direct transcriptional targets of ERG. Inhibition of ERG in TMPRSS2-ERG-positive VCaP cells led to decreased levels of NOTCH1 and 2 proteins and downstream transcriptional targets and partially recapitulated the phenotypes associated with ERG inhibition. Regulation of NOTCH1 and 2 genes by ERG were also noted with ectopic ERG expression in LNCaP (ERG-negative prostate cancer) and RWPE-1 (benign prostate-derived immortalized) cells. Furthermore, inhibition of NOTCH by the small-molecule γ-secretase inhibitor 1, GSI-1, conferred an increased sensitivity to androgen receptor (AR) inhibitors (bicalutamide and enzalutamide) or the androgen biosynthesis inhibitor (abiraterone) in VCaP cells. Combined treatment with bicalutamide and GSI-1 showed strongest inhibition of AR, ERG, NOTCH1, NOTCH2, and PSA protein levels along with decreased cell growth, cell survival, and enhanced apoptosis. Intriguingly, this effect was not observed in ERG-negative prostate cancer cells or immortalized benign/normal prostate epithelial cells. These data underscore the synergy of AR and NOTCH inhibitors in reducing the growth of ERG-positive prostate cancer cells.Implications: Combinational targeting of NOTCH and AR signaling has therapeutic potential in advanced ERG-driven prostate cancers. Mol Cancer Res; 15(10); 1308-17. ©2017 AACR.

Iron doped β-Tricalcium phosphate: Synthesis, characterization, hyperthermia effect, biocompatibility and mechanical evaluation

The ability of β-Tricalcium phosphate [β-TCP, β-Ca₃(PO₄)₂] to host iron at its structural lattice and its associated magnetic susceptibility, hyperthermia effect, biocompatibility and mechanical characteristics is investigated. The studies revealed the ability of β-Ca₃(PO₄)₂ to host 5.02mol% of Fe³⁺ at its Ca²⁺(5) site. Excess Fe³⁺ additions led to the formation of trigonal Ca₉Fe(PO₄)₇ and moreover a minor amount of CaFe₃(PO₄)₃O crystallization was also observed. A gradual increment in the iron content at β-Ca₃(PO₄)₂ results in the simultaneous effect of pronounced hyperthermia effect and mechanical stability. However, the presence of CaFe₃(PO₄)₃O contributes for the reduced hyperthermia effect and mechanical stability of iron substituted β-Ca₃(PO₄)₂. Haemolytic tests, cytotoxicity tests and ALP gene expression analysis confirmed the biocompatibility of the investigated systems.

Talking to children about their HIV status: a review of available resources, tools, and models for improving and promoting pediatric disclosure

As children living with HIV (CLHIV) grow into adolescence and adulthood, caregivers and healthcare providers are faced with the sensitive challenge of when to disclose to a CLHIV his or her HIV status. Despite WHO recommendations for CLHIV to know their status, in countries most affected by HIV, effective resources are often limited, and national guidance on disclosure is often lacking. To address the need for effective resources, gray and scientific literature was searched to identify existing tools and resources that can aid in the disclosure process. From peer-reviewed literature, seven disclosure models from six different countries were identified. From the gray literature, 23 resources were identified including children's books (15), job aides to assist healthcare providers (5), and videos (3). While these existing resources can be tailored to reflect local norms and used to aid in the disclosure process, careful consideration must be taken in order to avoid damaging disclosure practices.

Structural analysis and magnetic induced hyperthermia of Fe3+and Mn2+substituted β-Ca3(PO4)2

Fe³⁺/Mn²⁺co-substitutions in β-Ca₃(PO₄)₂elicit a good hyperthermia effect and biocompatible features.

Transcriptome and Proteome Analyses of TNFAIP8 Knockdown Cancer Cells Reveal New Insights into Molecular Determinants of Cell Survival and Tumor Progression

Tumor necrosis factor-α-inducible protein 8 (TNFAIP8) is the first discovered oncogenic and an anti-apoptotic member of a conserved TNFAIP8 or TIPE family of proteins. TNFAIP8 mRNA is induced by NF-kB, and overexpression of TNFAIP8 has been correlated with poor prognosis in many cancers. Downregulation of TNFAIP8 expression has been associated with decreased pulmonary colonization of human tumor cells, and enhanced sensitivities of tumor xenografts to radiation and docetaxel. Here we have investigated the effects of depletion of TNFAIP8 on the mRNA, microRNA and protein expression profiles in prostate and breast cancers and melanoma. Depending on the tumor cell type, knockdown of TNFAIP8 was found to be associated with increased mRNA expression of several antiproliferative and apoptotic genes (e.g., IL-24, FAT3, LPHN2, EPHA3) and fatty acid oxidation gene ACADL, and decreased mRNA levels of oncogenes (e.g., NFAT5, MALAT1, MET, FOXA1, KRAS, S100P, OSTF1) and glutamate transporter gene SLC1A1. TNFAIP8 knockdown cells also exhibited decreased expression of multiple onco-proteins (e.g., PIK3CA, SRC, EGFR, IL5, ABL1, GAP43), and increased expression of the orphan nuclear receptor NR4A1 and alpha 1 adaptin subunit of the adaptor-related protein complex 2 AP2 critical to clathrin-mediated endocytosis. TNFAIP8-centric molecules were found to be predominately implicated in the hypoxia-inducible factor-1α (HIF-1α) signaling pathway, and cancer and development signaling networks. Thus TNFAIP8 seems to regulate the cell survival and cancer progression processes in a multifaceted manner. Future validation of the molecules identified in this study is likely to lead to new subset of molecules and functional determinants of cancer cell survival and progression.

"Soldier's Heart": A Genetic Basis for Elevated Cardiovascular Disease Risk Associated with Post-traumatic Stress Disorder

"Soldier's Heart," is an American Civil War term linking post-traumatic stress disorder (PTSD) with increased propensity for cardiovascular disease (CVD). We have hypothesized that there might be a quantifiable genetic basis for this linkage. To test this hypothesis we identified a comprehensive set of candidate risk genes for PTSD, and tested whether any were also independent risk genes for CVD. A functional analysis algorithm was used to identify associated signaling networks. We identified 106 PTSD studies that report one or more polymorphic variants in 87 candidate genes in 83,463 subjects and controls. The top upstream drivers for these PTSD risk genes are predicted to be the glucocorticoid receptor (NR3C1) and Tumor Necrosis Factor alpha (TNFA). We find that 37 of the PTSD candidate risk genes are also candidate independent risk genes for CVD. The association between PTSD and CVD is significant by Fisher's Exact Test (P = 3 × 10^-54). We also find 15 PTSD risk genes that are independently associated with Type 2 Diabetes Mellitus (T2DM; also significant by Fisher's Exact Test (P = 1.8 × 10^-16). Our findings offer quantitative evidence for a genetic link between post-traumatic stress and cardiovascular disease, Computationally, the common mechanism for this linkage between PTSD and CVD is innate immunity and NFκB-mediated inflammation.

Molecular Characterization of Pro-Inflammatory Cytokines Interleukin-1β and Interleukin-8 in Asian Elephant (Elephas maximus)

Interleukin (IL)-1β and IL-8 are pro-inflammatory cytokines produced primarily by monocytes and macrophages in response to a variety of microbial and nonmicrobial agents. As yet, no molecular data have been reported for IL-1β and IL-8 of the Asian elephant. In the present study, we have cloned and sequenced the cDNA encoding IL-1β and IL-8 of the Asian elephant. The open reading frame (ORF) of Asian elephant IL-1β is 789 bp in length, encoded a propeptide of 263 amino acid polypeptide. The predicted protein revealed the presence of IL-1 family signature motif and an ICE cut site. Whereas, IL-8 contained 321 bp of open reading frame. Interestingly, the predicted protein sequence of 106 aa, contains an ELR motif immediately upstream of the CQC residues, common in all vertebrate IL-8 molecules. Identity levels of the nucleic acid and deduced amino acid sequences of Asian elephant IL-1β ranged from 68.48 (Squirrel monkey) to 98.57% (African elephant), and 57.78 (Sheep) to 98.47% (African elephant), respectively, whereas that of IL-8 ranged from 72.9% (Human) to 87.8% (African elephant), and 63.2 (human, gorilla, chimpanzee) to 74.5% (African elephant, buffalo), respectively. The phylogenetic analysis based on deduced amino acid sequenced showed that the Asian elephant IL-1β and IL-8 were most closely related to African elephant. Molecular characterization of these two cytokines, IL-1β and IL-8, in Asian elephant provides fundamental information necessary to progress the study of functional immune responses in this animal and gives the potential to use them to manipulate the immune response as recombinant proteins.

ZrxFe3−xO4 (0.01 ≤ x ≤ 1.0) nanoparticles: a possible magnetic in vivo switch

AC field controlled temperature during magnetic hyperthermia for ZrxFe_3−xO₄ (0.01 ≤ x ≤ 1.0) based ferrofluids. The unexpected behavior observed despite their high magnetization (~50 Am² kg⁻¹) and Curie temperature (T_C > 300 °C).

Abstract 5058: Silencing of NOTCH signaling enhances the sensitivity of ERG positive prostate cancer cells to AR inhibitors

Introduction: Androgen receptor (AR) signaling plays a critical role in all the stages of prostate cancer (CaP) ranging from organ confined to castration-resistant (CRPC) phases. Although androgen deprivation therapy (ADT) remains the mainstay treatment for advanced CaP, the inevitable transition from androgen- sensitive to CRCP presents the most significant challenge in CaP therapy. Androgen dependent expression of oncogenic ETS related gene (ERG) in half of all CaP in western countries plays critical role in the tumorigenesis of CaP through regulation of cancer specific signaling pathways. We found that NOTCH transcription factors are common targets of ERG in ERG positive cancer cells. NOTCH signaling pathway is an important signaling pathway in the development of drug-resistant tumor growth. In the current study we evaluated the combinatorial effects of NOTCH and AR inhibitors in the context of ERG positive prostate cancer cells.

Methods: ERG, NOTCH1, NOTCH2 and downstream targets of NOTCH transcription factors were analyzed by Western blot assays. Dose and time kinetics of combining NOTCH inhibitor (γ-Secretase inhibitor 1, GSI-1) and AR inhibitors (Bicalutamide, Enzalutamide, and Abiraterone) were assessed in a panel of ERG positive or ERG negative CaP cells. Trypan blue exclusion, methylthiazole tetrazolium (MTT), or ApoTox-Glo™ Triplex assays were used to asses cell proliferation, apoptosis and drug cytotoxicity.

Results: Prostate cancer cell lines with endogenous or ectopic expression of ERG showed upregulation of NOTCH1 and NOTCH2. The NOTCH inhibitor, GSI-1 conferred an increased sensitivity to all tested AR inhibitors (Bicalutamide, Enzalutamide, and Abiraterone) with bicalutamide showing the most robust inhibition of AR, ERG, NOTCH1, NOTCH2, PSA, decreased cell growth and enhanced apoptosis in ERG positive VCaP cells. This observation was not seen in ERG negative LNCaP cells or in ERG positive primary endothelial cells.

Conclusions: NOTCH inhibitor enhanced sensitivity of AR inhibitors in ERG positive VCaP cells growth. The combination of the GSI-1 with AR inhibitors has shown synergistic effect when compared to single agent treatment. Taken together, our study suggests that NOTCH inhibitors may enhance the actions of AR inhibitors in the treatment of ERG positive prostate cancers. Inhibition of AR and NOTCH signaling may offer new opportunities in assessing ERG targeted therapy for prostate cancer.

Citation Format: Ahmed A. Mohamed, Shyh-Han Tan, Shilpa Katta, Charles P. Xavier, Lakshmi Ravindranath, Wei Huang, Hua Li, Meera Srivastava, Shashwat Sharad, Taduru Sreenath, Gyorgy Petrovics, Albert Dobi, Shiv Srivastava. Silencing of NOTCH signaling enhances the sensitivity of ERG positive prostate cancer cells to AR inhibitors. [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 5058. doi:10.1158/1538-7445.AM2015-5058

Homology and enzymatic requirements of microhomology-dependent alternative end joining

Nonhomologous DNA end joining (NHEJ) is one of the major double-strand break (DSB) repair pathways in higher eukaryotes. Recently, it has been shown that alternative NHEJ (A-NHEJ) occurs in the absence of classical NHEJ and is implicated in chromosomal translocations leading to cancer. In the present study, we have developed a novel biochemical assay system utilizing DSBs flanked by varying lengths of microhomology to study microhomology-mediated alternative end joining (MMEJ). We show that MMEJ can operate in normal cells, when microhomology is present, irrespective of occurrence of robust classical NHEJ. Length of the microhomology determines the efficiency of MMEJ, 5 nt being obligatory. Using this biochemical approach, we show that products obtained are due to MMEJ, which is dependent on MRE11, NBS1, LIGASE III, XRCC1, FEN1 and PARP1. Thus, we define the enzymatic machinery and microhomology requirements of alternative NHEJ using a well-defined biochemical system.

Personalized Radioproteomics: Identification of a Protein Biomarker Signature for Preemptive Rescue by Tocopherol Succinate in CD34+ Irradiated Progenitor Cells Isolated from a Healthy Control Donor

Tocopherol succinate (TS) has been shown to protect mice against acute radiation syndrome, however, its exact mechanism of action and its possible use in humans has not yet been evaluated. Our approach has been to test the radioprotectant properties of TS on CD34-positive stem cells from healthy volunteers. We hypothesize that a radioproteomics strategy can identify a drug-dependent, personalized proteomics signature for radioprotection. To directly test the radioproteomics hypothesis, we treated human CD34-positive stem cells with 20 μM TS for 24 h, and then exposed the cells to 2 Gy of cobalt-60 gamma-radiation. We isolated protein from all cultures and used a high throughput Antibody Microarray (AbMA) platform to measure concentrations of 725 low abundance proteins. As an in vivo control, we also tested mouse CD34-positive stem cells using the same preemptive TS paradigm on progenitor colony forming units. TS pretreatment of in vitro or in vivo CD34-positive stem cells rescued radiation-induced loss of colony-forming potential of progenitors. We identified 50 of 725 proteins that could be preemptively rescued from radiation-induced reduction by pretreatment with TS. Ingenuity Pathway Analysis (IPA) reveals that the modified proteins fall into categories dominated by epigenetic regulation, DNA repair, and inflammation. Our results suggest that radioproteomics can be used to develop personalized medicine for radioprotection using protein signatures from primary CD34-positive progenitors derived from the patient or victim prior to radiation exposure. The protective effect of TS may be due to its ability to preemptively activate epigenetic mechanisms relevant to radioprotection and to preemptively activate the programs for DNA repair and inflammation leading to cell survival.

Reduced PARP1 as a Serum Biomarker for Graft Rejection in Kidney Transplantation

A serum proteomics platform enabling expression Profiling in transplantation-associated clinical subsets gives an opportunity to identify non-invasive biomarkers that can accurately predict transplant outcome. In this study, we attempted to identify candidate serum biomarkers that could predict kidney allograft rejection/injury, regardless of its etiological and therapeutic heterogeneity. Using serum samples collected from kidney transplantation patients and healthy controls, we first employed Clontech-500 Ab microarrays to Profile acute rejection (AR) and chronic graft injury (CGI) versus stable graft function (SF) and normal kidneys (NK). Using GenePattern analysis of duplicate arrays on pooled samples, we identified gender-independent biomarkers PARP1, MAPK1, SRP54, DP1, and p57 (FDR ≈ 25%), the concordant downregulation of which represented a detrimental Profile common for both rejection/ injury types (AR-CGI). The reverse phase arrays qualified a 2-fold upregulation of PARP1 with an ROC of 0.87 in individual samples from patients with SF vs. AR-CGI rendering serum PARP1 as a biomarker for early prognosis. Ingenuity Pathways Analysis (IPA) connected PARP1 to some other markers (MAPK1), elucidating their possible interactions and connections to the immune response and graft-versus-host disease signaling. The downregulation of serum PARP1 in the damaged graft tissues, represents a perspective non-invasive marker, predicting the failing kidney graft, regardless of rejection/injury causes or gender. Thus, the successful identification of PARP1 as a bio-marker in limited patient cohorts demonstrates that serum proteomics platform empowered by the GenePattern- and IPA-based Bioinformatics algorithm can guarantee a successful development of the clinically applicable prognostic biomarker panel.

Rapid profiling and structural characterization of bioactive compounds and their distribution in different parts of Berberis petiolaris Wall. ex G. Don applying hyphenated mass spectrometric techniques

RATIONALE

Berberis petiolaris Wall. is a lesser known medicinal plant, belonging to the family Berberidaceae. The genus Berberis is known for many biological activities such as anti-microbial, anti-inflammatory and anti-diarrheal, etc. There are not many reports of the isolation of components from Berberis petiolaris. This study aims to seek identification, characterization and quantification of components.

METHODS

A method was developed for rapid screening of phytochemicals using high-pressure liquid chromatography hyphenated with quadrupole time-of-flight mass spectrometry (HPLC/ESI-QTOF-MS/MS). Suitable collision-induced dissociation mass spectrometry (CID-MS/MS) methods were developed for structural investigation of alkaloids, flavanoids and other classes of compounds using nine reference standards for authentication. Multiple reaction monitoring (MRM) methods were developed for quantitative study of five constituents using triple quadrupole-linear ion trap mass spectrometry (UPLC/QqLIT-MS/MS).

RESULTS

On the basis of HPLC retention behavior and fragmentation pathways obtained by high-resolution MS and MS/MS, 32 compounds were identified and characterized in different parts of Berberis petiolaris. Quantitative studies of chlorogenic acid, magnoflorine, jatrorrhizine, palmatine and berberine were also completed successfully.

CONCLUSIONS

Rapid and accurate HPLC/ESI-QTOF-MS/MS and UPLC/ESI-QqLIT-MS/MS methods were established for identification, characterization and quantification of phytochemicals in the ethanolic extract of Berberis petiolaris. These methods, therefore, can be used for studies on phytochemical variation in different parts of the plant. Principle components analysis (PCA) may be used for plant part discrimination.

Abstract 3909: Cisplatin resistant head and neck cancer cells are susceptible to growth inhibition by CDF curcumin

Head and neck (H&N) cancer is the sixth most common type of cancer, with about 650,000 new cases in the world every year. Platinum-based agents (cisplatin/carboplatin) are the most common chemotherapeutic agents for H&N cancer; however the five year survival rate is only 50% and development of drug resistance is one of the major challenges for effective therapy. Thus, development of new strategies to overcome drug resistance will help in H&N cancer treatment. Our studies using H&N cancer cisplatin resistant cell lines in vitro have indicated that Cancer Stem cell (CSC) specific markers such as CD44 and cytokines (IL-8, IL-10) are up-regulated during the development of drug resistance. Furthermore, our in vitro studies indicated that the treatment of drug resistant cell lines with a novel synthetic curcumin analog known as CDF in liposomal encapsulation (liposomal CDF) resulted in statistically significant growth inhibition (p<0.05). Similarly, our studies in a nude mouse xenograft drug resistant H&N cancer tumor model showed that treatment with liposomal CDF (1 mg/100 µl in saline, i.v. injection 5 days a week for 3 weeks) resulted in greater than 50% tumor growth inhibition. The CDF treated cell lines and xenograft tumors showed a statistically significant reduction in the expression of CD44 (p<0.05), indicating an inhibitory effect of CDF on cancer stem cells, which is consistent with previously published data on other tumor models. These results demonstrate that CDF can be useful for the treatment of drug resistant H&N cancer.

Citation Format: Saroj K. Basak, Alborz Zinabadi, Natarajan Venkatesan, Victor M. Duarte, Clifton L. Dalgard, Meera Srivastava, Marilene B. Wang, Fazlul H. Sarkar, Eri S. Srivatsan. Cisplatin resistant head and neck cancer cells are susceptible to growth inhibition by CDF curcumin. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3909. doi:10.1158/1538-7445.AM2014-3909