Postoperative Restrictive Opioid Protocols and Durable Changes in Opioid Prescribing and Chronic Opioid Use

Importance

Changes in postsurgical opioid prescribing practices may help reduce chronic opioid use in surgical patients.

Objective

To investigate whether postsurgical acute pain across different surgical subspecialties can be managed effectively after hospital discharge with an opioid supply of 3 or fewer days and whether this reduction in prescribed opioids is associated with reduced new, persistent opioid use.

Design, Setting, and Participants

In this prospective cohort study with a case-control design, a restrictive opioid prescription protocol (ROPP) specifying an opioid supply of 3 or fewer days after discharge from surgery along with standardized patient education was implemented across all surgical services at a tertiary-care comprehensive cancer center. Participants were all patients who underwent surgery from August 1, 2018, to July 31, 2019.

Main Outcomes and Measures

Main outcomes were the rate of compliance with the ROPP in each surgical service, the mean number of prescription days and refill requests, type of opioid prescribed, and rate of conversion to chronic opioid use determined via a state-run opioid prescription program. Postsurgical complications were also measured.

Results

A total of 4068 patients (mean [SD] age, 61.0 [13.8] years; 2528 women [62.1%]) were included, with 2017 in the pre-ROPP group (August 1, 2018, to January 31, 2019) and 2051 in the post-ROPP group (February 1, 2019, to July 31, 2019). The rate of compliance with the protocol was 95%. After implementation of the ROPP, mean opioid prescription days decreased from a mean (SD) of 3.9 (4.5) days in the pre-ROPP group to 1.9 (3.6) days in the post-ROPP group (P < .001). The ROPP implementation led to a 45% decrease in prescribed opioids after surgery (mean [SD], 157.22 [338.06] mean morphine milligram equivalents [MME] before ROPP vs 83.54 [395.70] MME after ROPP; P < .001). Patients in the post-ROPP cohort requested fewer refills (367 of 2051 [17.9%] vs 422 of 2017 [20.9%] in the pre-ROPP cohort; P = .02). There was no statistically significant difference in surgical complications. The conversion rate to chronic opioid use decreased following ROPP implementation among both opioid-naive patients with cancer (11.3% [143 of 1267] to 4.5% [118 of 2645]; P < .001) and those without cancer (6.1% [19 of 310] to 2.7% [16 of 600]; P = .02).

Conclusions and Relevance

In this cohort study, prescribing an opioid supply of 3 or fewer days to surgical patients after hospital discharge was feasible for most patients, led to a significant decrease in the number of opioids prescribed after surgery, and was associated with a significantly decreased conversion to long-term opioid use without concomitant increases in refill requests or significant compromises in surgical recovery.

Abstract 1093: BRD9 inhibition overcomes epithelial to mesenchymal transition (EMT)-associated tyrosine kinase inhibitor (TKI) tolerance in epidermal growth factor receptor (EGFR) mutant lung cancer

Advanced lung cancer patients that present with activating mutations in the epidermal growth factor receptor (EGFR) are treated with EGFR tyrosine kinase inhibitors (EGFR TKIs). While initially effective, all patients eventually develop therapeutic resistance and experience disease progression. Strategies to prevent EGFR TKI resistance are needed to improve patient outcomes. We chronically exposed H1975 cells (EGFR-L858R/T790M) to EGFR TKI osimertinib to study emergence of resistance. H1975 cells that were expanded under drug treatment (designated H1975OR) acquired an EMT phenotype and were re-sensitized to EGFR TKI upon prolonged drug withdrawal. These features led us to classify H1975OR as a model of drug tolerance rather than a model of stable drug resistance. Bulk RNA-sequencing revealed significant dysregulation of chromatin modifying genes in H1975OR. Bromodomain containing protein 9 (BRD9) was among the set of significantly upregulated chromatin regulators and was selected for further investigation as a mediator of drug tolerance. Although BRD9 is known to control stemness and EMT, its role in promoting EMT-associated TKI resistance is unknown. To test the contribution of BRD9 to EGFR TKI tolerance, pharmacological inhibition of BRD9 by the selective inhibitor, I-BRD9 significantly increased sensitivity to TKI in models with EMT phenotypes (IC50 reduced 3-4 fold). In contrast, I-BRD9 did not affect TKI sensitivity in two models where EGFR TKI resistance was genetically fixed. To gain mechanistic insights, H1975OR cells were treated with osimertinib +/-I-BRD9 and subjected to RNA-sequencing. Combination of osimertinib with I-BRD9 resulted in a significant decrease in EMT-related genes, including MMP9, Zeb2, PDGFRb and IL6. Further, use of I-BRD9 in these models diminished the mesenchymal phenotype, as measured in cell invasion assays. Genetic knockdown of BRD9 via shRNA phenocopied effects of I-BRD9 treatment, supporting BRD9 as the therapeutic target of I-BRD9 in our cell line models. To further establish a role for BRD9 in the emergence of drug tolerant cells, we exposed treatment naïve H1975 cells to EGFR TKI ± I-BRD9. I-BRD9 significantly decreased the size of the EGFR TKI tolerant population. In time course studies, I-BRD9 also delayed onset of TKI resistance. In conclusion, our data identifies BRD9 as a novel mediator of EMT-associated EGFR-TKI tolerance in EGFR-mutant lung cancer. Our data further implicates BRD9 inhibition as a novel strategy to delay the emergence of drug tolerant cells that eventually give rise to stable drug resistance. This work was supported by the Roswell Park Alliance Foundation and National Cancer Institute (NCI) grant P30CA016056 involving the use of Roswell Park Comprehensive Cancer Center’s Genomics and Bioinformatics Shared Resources.

Citation Format: Hannah Calkins, Tatiana Shaurova, David W. Goodrich, Mukund Seshadri, Candace S. Johnson, Pamela A. Hershberger. BRD9 inhibition overcomes epithelial to mesenchymal transition (EMT)-associated tyrosine kinase inhibitor (TKI) tolerance in epidermal growth factor receptor (EGFR) mutant lung 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 1093.

The Influence of Vitamin D on Mammographic Density: Results from CALGB 70806 (Alliance) a Randomized Clinical Trial

Current therapies for breast cancer prevention only prevent estrogen receptor positive (ER+) disease and toxicity limits use of these agents. Vitamin D is a potential prevention therapy for both ER+ and ER- disease and is safe with few side effects. This study evaluates the effect of 1-year of vitamin D supplementation on mammographic density (MD), a biomarker of breast cancer risk in a multicenter randomized controlled trial. Premenopausal women with ≥25% MD and no history of cancer were randomly assigned to 2,000 international units (IU) of vitamin D or placebo orally daily for 1 year. Change in percent MD was evaluated using Cumulus software after all participants completed treatment. Three hundred women enrolled between January 2011 and December 2013 with a mean age of 43 and diverse ethnicity [14% Hispanic, 12% African American (AA)]. Supplementation significantly increased vitamin D levels compared with placebo (14.5 ng/mL vs. -1.6 ng/mL; P < 0.0001) with all participants on the vitamin D arm achieving vitamin D sufficiency at 12 months. Vitamin D was safe and well tolerated. After adjustment for baseline MD, the mean between-arm difference (vitamin D vs. placebo) at 1 year was -0.75 (-0.26, 1.76; P = 0.56). A greater effect was seen for women with ≥50% MD and AA women, although neither reached significance. This randomized controlled trial demonstrated significant improvement in vitamin D levels with 2,000 IU for 1 year, with 100% of supplemented women achieving sufficiency. However, a null effect was seen regarding change in MD for premenopausal women (the primary outcome of the study). PREVENTION RELEVANCE: Current therapies for breast cancer prevention only prevent estrogen receptor positive (ER+) disease and are underutilized due to toxicity and side effects. Vitamin D is a potential prevention therapy for both ER+ and ER- disease and is safe with few side effects.

Vitamin D3 Metabolites Demonstrate Prognostic Value in EGFR-Mutant Lung Adenocarcinoma and Can be Deployed to Oppose Acquired Therapeutic Resistance

EGFR tyrosine kinase inhibitors (EGFR TKIs) are the standard of care treatment for patients with EGFR-mutant lung adenocarcinoma (LUAD). Although initially effective, EGFR TKIs are not curative. Disease inevitably relapses due to acquired drug resistance. We hypothesized that vitamin D metabolites could be used with EGFR TKIs to prevent therapeutic failure. To test this idea, we investigated the link between serum 25-hydroxyvitamin D3 (25(OH)D3) and progression-free survival (PFS) in patients with EGFR-mutant LUAD that received EGFR TKIs (erlotinib n = 20 and afatinib n = 1). Patients who were 25(OH)D3-sufficient experienced significantly longer benefit from EGFR TKI therapy (mean 14.5 months) than those with 25(OH)D3 insufficiency (mean 10.6 months, p = 0.026). In contrast, 25(OH)D3 had no prognostic value in patients with KRAS-mutant LUAD that received cytotoxic chemotherapy. To gain mechanistic insights, we tested 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) activity in vitro. 1,25(OH)2D3 promoted epithelial differentiation and restored EGFR TKI sensitivity in models of EGFR TKI resistance that were associated with epithelial–mesenchymal transition (EMT). 1,25(OH)2D3 was ineffective in a non-EMT model of resistance. We conclude that vitamin D sufficiency portends increased PFS among EGFR-mutant LUAD patients that receive EGFR TKIs, and that vitamin D signaling maintains drug efficacy in this specific patient subset by opposing EMT.

The phenomenon of para-Fluorophenylpiperazine (pFPP) in combination with the synthetic cannabinoid AMB-FUBINACA in seized plant material in New Zealand

New psychoactive substances have emerged as a vast and diverse group of illicit drugs over the past decade, with synthetic cannabinoids comprising the largest of the categories. Commonly, a single synthetic cannabinoid is applied to plant material, creating a product that is designed to be smoked by the user. The clandestine preparation process can result in an unevenly distributed product, with varying concentration within and between plant materials. This investigation describes the novel co-detection of the synthetic cannabinoid AMB-FUBINACA, with the piperazine para-fluorophenylpiperazine (pFPP), in a number of plant material samples analysed in New Zealand in 2017. Of 157 samples of plant material containing AMB-FUBINACA, pFPP was detected in 55 of them. A range of pFPP concentrations was observed between the plant material samples, as well as intra-batch variation. The presence of both drugs may be designed to enhance, prolong or balance the psychoactive effects caused from smoking the plant material. However the intended purpose has not been verified. This is the first reported combination of a synthetic cannabinoid and a piperazine in plant material.

Association among plasma 1,25(OH)2 D, ratio of 1,25(OH)2 D to 25(OH)D, and prostate cancer aggressiveness

BACKGROUND

African-American (AA) men tend to present with more aggressive prostate cancer (Gleason score >7) than European-American (EA) men. Vitamin D and its metabolites are implicated in prostate cancer biology with vitamin D deficiency, indicated by its metabolite levels in serum or plasma, usually observed in AA men.

OBJECTIVE

To determine if 1, 25-dihydroxy vitamin D3 [1,25(OH)2 D] plasma levels in AA and EA prostate cancer patients alter the risk of having aggressive prostate cancer.

DESIGN

Research subjects from the North Carolina-Louisiana Prostate Cancer Project (AA n = 435 and EA n = 532) were included. Plasma metabolites 1,25(OH)2 D and 25-hydroxyvitamin D3 [25(OH)D] were measured using liquid chromatography with tandem mass spectrophotometry. Research subjects were classified into low (Gleason sum < 7, stage T1-T2, and Prostate-specific antigen (PSA) < 9 ng/mL) or high (Gleason sum > 8 or Gleason sum = 7 with 4 + 3, or PSA > 20 ng/mL, or Gleason sum = 7 and stage T3-T4) aggressive disease.

RESULTS

Research subjects in the second and third tertiles of plasma levels of 1, 25(OH)2 D had lower odds of high aggressive prostate cancer (AA [ORT2vsT1 : 0.66, 95%CI: 0.39-1.12; ORT3vsT1 : 0.83, 95%CI: 0.49-1.41] and EA [ORT2vsT1 : 0.68, 95%CI: 0.41-1.11; ORT3vsT1 : 0.67, 95%CI: 0.40-1.11]) compared with the first tertile, though confidence intervals included the null. Greater 1,25(OH)2 D/25(OH)D molar ratios were associated with lower odds of high aggressive prostate cancer more evidently in AA (ORQ4vsQ1 : 0.45, CI: 0.24-0.82) than in EA (ORQ4vsQ1 : 0.64, CI: 0.35-1.17) research subjects.

CONCLUSIONS

The 1,25(OH)2 D/25(OH)D molar ratio was associated with decreased risk of high aggressive prostate cancer in AA men, and possibly in EA men. Further studies analyzing vitamin D polymorphisms, vitamin D binding protein levels, and prostatic levels of these metabolites may be useful. These studies may provide a better understanding of the vitamin D pathway and its biological role underlying health disparities in prostate cancer.

Vitamin D3 enhances the response to cisplatin in bladder cancer through VDR and TAp73 signaling crosstalk

Background

Vitamin D₃ (VitD) deficiency is linked to increased incidence and worse survival in bladder cancer (BCa). In addition to cystectomy, patients are treated with cisplatin‐based chemotherapy, however 30%‐50% of patients do not benefit from this treatment. The effects of VitD deficiency on response to chemotherapy remain unknown.

Methods

To test effects of VitD supplementation on the response to cisplatin we analyzed patient serum VitD levels and correlated that with survival. In vivo, VitD deficient mice were treated with cisplatin, with or without pretreatment with the active VitD metabolite, 1,25 dihydroxyvitamin D₃ (1,25D₃). Lastly, using BCa cell lines, T24 and RT‐112, the mechanism of action of 1,25D₃ and cisplatin combination treatment was determined by apoptosis assays, as well as western blot and RT‐PCR.

Results

In this study, we determined that low serum 25 hydroxyvitamin D₃ (25D₃) levels was significantly associated with worse response to cisplatin. Pretreating deficient mice with 1,25D₃, reduced tumor volume compared to cisplatin monotherapy. In vitro, 1,25D₃ pretreatment increased the apoptotic response to cisplatin. 1,25D₃ pretreatment increased expression of TAp73 and its pro‐apoptotic targets, in a VDR dependent manner. VDR and its transcriptional targets were induced after 1,25D₃ treatment and further increased after the combination of 1,25D₃ and cisplatin in a TAp73 dependent manner.

Conclusions

Our data suggest that VitD deficiency could be a biomarker for poor response to cisplatin, and pretreating with VitD can increase the apoptotic response to cisplatin through VDR and TAp73 signaling crosstalk.

Capacity fade in high energy silicon-graphite electrodes for lithium-ion batteries

A silicon-graphite blended anode is paired with a high capacity LiFePO4 reference/counter electrode to track irreversibility and lithium inventory. The LiFePO4 electrode provides a reliable, flat potential for dQ dV-1 analysis of LixSi and LixC electrochemical reactions. We relate this electrochemistry to the morphological and physical changes taking place.

Relationship between Fear of Falling and Preceived Difficulty with Grocery Shopping

Fear of falling is associated with self-imposed restrictions of basic and instrumental activities of daily living (ADL/IADL), leading greater risk for functional decline and falls. The inability to independently grocery shop, a food-related IADL, negatively affects nutritional status and survival among seniors. Thus, this study examined the relationship between the fear of falling and difficulty with grocery shopping among seniors (n=98, mean age=82, 83% female), taking into account their functional capacity. Demographic profile, eating problems, physical fitness (mobility, balance, endurance, leg strength), and fear of falling (balance confidence, falls efficacy) were measured. Fifty-six percent of participants reported difficulty with grocery shopping. Those who reported difficulty had significantly lower scores for dynamic balance, balance confidence and fall efficacy compared to those who did not. This study revealed a relationship between the fear of falling and perceived difficulty with grocery shopping. Interventions should address fear of falling among the frail seniors.

Genomic profiling is predictive of response to cisplatin treatment but not to PI3K inhibition in bladder cancer patient-derived xenografts

Purpose

Effective systemic therapeutic options are limited for bladder cancer. In this preclinical study we tested whether bladder cancer gene alterations may be predictive of treatment response.

Experimental design

We performed genomic profiling of two bladder cancer patient derived tumor xenografts (PDX). We optimized the exome sequence analysis method to overcome the mouse genome interference.

Results

We identified a number of somatic mutations, mostly shared by the primary tumors and PDX. In particular, BLCAb001, which is less responsive to cisplatin than BLCAb002, carried non-sense mutations in several genes associated with cisplatin resistance, including MLH1, BRCA2, and CASP8. Furthermore, RNA-Seq analysis revealed the overexpression of cisplatin resistance associated genes such as SLC7A11, TLE4, and IL1A in BLCAb001. Two different PIK3CA mutations, E542K and E545K, were identified in BLCAb001 and BLCAb002, respectively. Thus, we tested whether the genomic profiling was predictive of response to a dual PI3K/mTOR targeting agent, LY3023414. Despite harboring similar PIK3CA mutations, BLCAb001 and BLCAb002 exhibited differential response, both in vitro and in vivo. Sustained target modulation was observed in the sensitive model BLCAb002 but not in BLCAb001, as well as decreased autophagy. Interestingly, computational modelling of mutant structures and affinity binding to PI3K revealed that E542K mutation was associated with weaker drug binding than E545K.

Conclusions

Our results suggest that the presence of activating PIK3CA mutations may not necessarily predict in vivo treatment response to PI3K targeted therapies, while specific gene alterations may be predictive for cisplatin response in bladder cancer models and, potentially, in patients as well.

1,25D3 differentially suppresses bladder cancer cell migration and invasion through the induction of miR-101-3p

Metastasis is the major cause of bladder cancer death. 1,25D₃, the active metabolite of vitamin D, has shown anti-metastasis activity in several cancer model systems. However, the role of 1,25D₃ in migration and invasion in bladder cancer is unknown. To investigate whether 1,25D₃ affects migration and invasion, four human bladder cell lines with different reported invasiveness were selected: low-invasive T24 and 253J cells and highly invasive 253J-BV and TCCSUP cells. All of the four bladder cancer cells express endogenous and inducible vitamin D receptor (VDR) as examined by immunoblot analysis. 1,25D₃ had no effect on the proliferation of bladder cancer cells as assessed by MTT assay. In contrast, 1,25D₃ suppressed migration and invasion in the more invasive 253J-BV and TCCSUP cells, but not in the low-invasive 253J and T24 cells using “wound” healing, chemotactic migration and Matrigel-based invasion assays. 1,25D₃ promoted the expression of miR-101-3p and miR-126-3p in 253J-BV cells as examined by qRT-PCR. miR-101-3p inhibitor partially abrogated and pre-miR-101-3p further suppressed the inhibition of 1,25D₃ on migration and invasion in 253J-BV cells. Further, 1,25D₃ enhanced VDR recruitment to the promoter region of miR-101-3p using ChIP-qPCR assay. 1,25D₃ enhanced the promoter activity of miR-101-3p as evaluated by luciferase reporter assay. Taken together, 1,25D₃ suppresses bladder cancer cell migration and invasion in two invasive/migration competent lines but not in two less invasive/motile lines, which is partially through the induction of miR-101-3p expression at the transcriptional level.

Abstract 1086: Vitamin D3 increases the response to cisplatin in bladder cancer through VDR and TAp73 pathway crosstalk

Neoadjuvant cisplatin-based chemotherapy is used to treat muscle invasive bladder cancer (MIBC); however the relative 5-year survival of advanced disease is only 15%. The two major pitfalls of neoadjuvant chemotherapy are delaying cystectomy in patients with poor response to cisplatin, and the lack of available biomarkers to identify these patients. Previous studies in our lab showed that pretreatment of preclinical bladder cancer models with 1,25 dihydroxyvitamin D3 (1,25D3), the active metabolite of vitamin D3, enhances the apoptotic response to cisplatin. Mechanistic understanding can provide insight into potential markers for response to 1,25D3 and cisplatin combination therapy in patients. Greater than 50% of MIBCs harbor p53 mutations; however p53 status has not been linked to clinical response to cisplatin. We previously determined that TAp73, a pro-apoptotic p53 family member protein induced after DNA damage, is required for the response to 1,25D3 and cisplatin. In two bladder cancer cell lines with mutant p53, T24 and RT-112, we identified signaling crosstalk between the vitamin D receptor (VDR) and TAp73. Treatment with 1,25D3 and cisplatin, compared to either alone, results in greatest increase of TAp73 mRNA and protein, 2-fold (T24) and 15-fold (RT-112), as well as TAp73 transcriptional target BAX, 3-fold (T24), and 4-fold (RT-112). TAp73 and BAX induction is lost in cells transfected with VDR siRNA, indicating a requirement for VDR. Cells treated with 1,25D3 and cisplatin, compared to either alone, also show the greatest increase of VDR mRNA and protein, 3-fold (T24) and 4-fold (RT-112). CYP24A1, a VDR target gene, has the greatest induction after the combination treatment as well, with an increase of approx. 60-fold (T24), and 100-fold (RT-112). CYP24A1 induction requires TAp73, determined using TAp73 shRNA. These data demonstrate that VDR signaling is enhanced by cisplatin treatment, and TAp73 signaling is enhanced by 1,25D3. We expanded these findings in vivo by treating mice on a vitamin D3 sufficient diet (1,000 IU) or a vitamin D3 deficient diet (25 IU) with 5 mg/kg of cisplatin (IP, q.wk for 3 weeks). Initially, mice on both diets respond to cisplatin treatment, as evidence by a 30% reduction in tumor volume. After the second cycle of treatment, tumors in the deficient mice stopped responding and returned to their initial tumor volume within 24 days. In the sufficient mice, tumors continued to respond to cisplatin with a maximum reduction of 50%. This was maintained for approximately 40 days after treatment. Further study will determine the molecular response to confirm our in vitro mechanism. Our work suggests that vitamin D3 is important in and can increase the response to cisplatin, it also provides rationale for investigating TAp73 protein levels and serum vitamin D3 levels as potential markers to determine patients’ likelihood of responding to cisplatin.

Citation Format: Brittany L. Bunch, Donald Trump, Candace S. Johnson. Vitamin D3 increases the response to cisplatin in bladder cancer through VDR and TAp73 pathway crosstalk [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 1086. doi:10.1158/1538-7445.AM2017-1086

Abstract 1190: Pretreatment with 1,25 dihydroxyvitamin D3 modulates p73 levels and activity to increase pro-apoptotic effects of cisplatin in bladder cancer

Cisplatin-based combination chemotherapy is the standard treatment for advanced bladder cancer. While there is a substantial initial response rate and occasional complete response, long term control is uncommon. There is a substantial need to develop new therapeutic approaches to bladder cancer. 1,25 dihydroxyvitamin D3 (1,25D3), the active metabolite of vitamin D, enhances the anti-tumor effects of cisplatin in preclinical bladder cancer models. We sought to evaluate the mechanism of 1,25D3 potentiation of cisplatin cytotoxicity through in vitro studies in bladder cancer cell lines. Our studies suggest that enhanced cytotoxicity is mediated through modulation of p73. In a clonogenic assay, the surviving fraction after treatment with 1,25D3 (0.1 uM) for 24 hrs followed by cisplatin (0.1 ug/ml) for 48 hrs increases from 64% to 97% in T24 cells transfected with shRNA targeting p73. The ratio of the pro-apoptotic TAp73 isoform to the anti-apoptotic ΔNp73 isoform is important in determining cellular response to cisplatin. Our studies demonstrate that pretreatment with 1,25D3 followed by cisplatin significantly increases the ratio of TA/ΔNp73 mRNA transcripts 2-fold and increases BAX, the transcriptional target of TAp73, approximately 3-fold. Protein levels of TAp73 and BAX are also increased 2- and 3-fold, respectively, as determined by western blot. Protein stability of TAp73 was determined following cycloheximide treatment for 1, 2, and 4 hrs. After 4 hrs of cycloheximide treatment, protein levels of TAp73 decrease by approximately 50% in all treatment groups except the 1,25D3 and cisplatin group, in which the level of TAp73 protein was maintained. This suggests an increase in TAp73 protein stability after treatment. Using a TransAm p53 binding assay after p53 immunodepletion, 1,25D3 and cisplatin treatment increases DNA binding of TAp73 approximately 2-fold. Protein levels of TAp73 upstream activators, c-Abl and p38, also increase approximately 2-fold after 1,25D3 treatment, suggesting a mechanism of action for increased stability and activation of TAp73. Lastly, pharmacologic inhibition of p38 activation using SB203580 prevents the synergistic effects of 1,25D3 and cisplatin. Taken together, these data suggest that the mechanism of synergy for 1,25D3 and cisplatin combination therapy is through an increase in TAp73 stability and pro-apoptotic transcriptional activity. These findings suggest that 1,25D3 may have potential to be used in combination with cisplatin to increase the apoptotic response. Further studies are being performed to confirm the effects of treatment in an in vivo model, looking both at short term molecular response and long term therapeutic response to treatment. Supported by NCI grants CA067267 and CA016056.

Citation Format: Brittany L. Bunch, Candace S. Johnson, Donald L. Trump. Pretreatment with 1,25 dihydroxyvitamin D3 modulates p73 levels and activity to increase pro-apoptotic effects of cisplatin in bladder cancer. [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 1190.

Whole-genome sequencing of a malignant granular cell tumor with metabolic response to pazopanib

Granular cell tumors are an uncommon soft tissue neoplasm. Malignant granular cell tumors comprise <2% of all granular cell tumors, are associated with aggressive behavior and poor clinical outcome, and are poorly understood in terms of tumor etiology and systematic treatment. Because of its rarity, the genetic basis of malignant granular cell tumor remains unknown. We performed whole-genome sequencing of one malignant granular cell tumor with metabolic response to pazopanib. This tumor exhibited a very low mutation rate and an overall stable genome with local complex rearrangements. The mutation signature was dominated by C>T transitions, particularly when immediately preceded by a 5' G. A loss-of-function mutation was detected in a newly recognized tumor suppressor candidate, BRD7. No mutations were found in known targets of pazopanib. However, we identified a receptor tyrosine kinase pathway mutation in GFRA2 that warrants further evaluation. To the best of our knowledge, this is only the second reported case of a malignant granular cell tumor exhibiting a response to pazopanib, and the first whole-genome sequencing of this uncommon tumor type. The findings provide insight into the genetic basis of malignant granular cell tumors and identify potential targets for further investigation.

Vitamin D Signaling Modulators in Cancer Therapy

The antiproliferative and pro-apoptotic effects of 1α,25-dihydroxycholecalciferol (1,25(OH)2D3, 1,25D3, calcitriol) have been demonstrated in various tumor model systems in vitro and in vivo. However, limited antitumor effects of 1,25D3 have been observed in clinical trials. This may be attributed to a variety of factors including overexpression of the primary 1,25D3 degrading enzyme, CYP24A1, in tumors, which would lead to rapid local inactivation of 1,25D3. An alternative strategy for improving the antitumor activity of 1,25D3 involves the combination with a selective CYP24A1 inhibitor. The validity of this approach is supported by numerous preclinical investigations, which demonstrate that CYP24A1 inhibitors suppress 1,25D3 catabolism in tumor cells and increase the effects of 1,25D3 on gene expression and cell growth. Studies are now required to determine whether selective CYP24A1 inhibitors+1,25D3 can be used safely and effectively in patients. CYP24A1 inhibitors plus 1,25D3 can cause dose-limiting toxicity of vitamin D (hypercalcemia) in some patients. Dexamethasone significantly reduces 1,25D3-mediated hypercalcemia and enhances the antitumor activity of 1,25D3, increases VDR-ligand binding, and increases VDR protein expression. Efforts to dissect the mechanisms responsible for CYP24A1 overexpression and combinational effect of 1,25D3/dexamethasone in tumors are underway. Understanding the cross talk between vitamin D receptor (VDR) and glucocorticoid receptor (GR) signaling axes is of crucial importance to the design of new therapies that include 1,25D3 and dexamethasone. Insights gained from these studies are expected to yield novel strategies to improve the efficacy of 1,25D3 treatment.

Genetic variations in vitamin D-related pathways and breast cancer risk in African American women in the AMBER consortium

Studies of genetic variations in vitamin D-related pathways and breast cancer risk have been conducted mostly in populations of European ancestry, and only sparsely in African Americans (AA), who are known for a high prevalence of vitamin D deficiency. We analyzed 24,445 germline variants in 63 genes from vitamin D-related pathways in the African American Breast Cancer Epidemiology and Risk (AMBER) consortium, including 3,663 breast cancer cases and 4,687 controls. Odds ratios (OR) were derived from logistic regression models for overall breast cancer, by estrogen receptor (ER) status (1,983 ER positive and 1,098 ER negative), and for case-only analyses of ER status. None of the three vitamin D-related pathways were associated with breast cancer risk overall or by ER status. Gene-level analyses identified associations with risk for several genes at a nominal p ≤ 0.05, particularly for ER- breast cancer, including rs4647707 in DDB2. In case-only analyses, vitamin D metabolism and signaling pathways were associated with ER- cancer (pathway-level p = 0.02), driven by a single gene CASR (gene-level p = 0.001). The top SNP in CASR was rs112594756 (p = 7 × 10(-5), gene-wide corrected p = 0.01), followed by a second signal from a nearby SNP rs6799828 (p = 1 × 10(-4), corrected p = 0.03). In summary, several variants in vitamin D pathways were associated with breast cancer risk in AA women. In addition, CASR may be related to tumor ER status, supporting a role of vitamin D or calcium in modifying breast cancer phenotypes.

Vitamin D Repletion Reduces the Progression of Premalignant Squamous Lesions in the NTCU Lung Squamous Cell Carcinoma Mouse Model

The chemopreventive actions of vitamin D were examined in the N-nitroso-tris-chloroethylurea (NTCU) mouse model, a progressive model of lung squamous cell carcinoma (SCC). SWR/J mice were fed a deficient diet (D) containing no vitamin D3, a sufficient diet (S) containing 2,000 IU/kg vitamin D3, or the same diets in combination with the active metabolite of vitamin D, calcitriol (C; 80 μg/kg, weekly). The percentage (%) of the mucosal surface of large airways occupied by dysplastic lesions was determined in mice after treatment with a total dose of 15 or 25 μmol NTCU (N). After treatment with 15 μmol NTCU, the percentages of the surface of large airways containing high-grade dysplastic (HGD) lesions were vitamin D-deficient + NTCU (DN), 22.7% [P < 0.05 compared with vitamin D-sufficient +NTCU (SN)]; DN + C, 12.3%; SN, 8.7%; and SN + C, 6.6%. The extent of HGD increased with NTCU dose in the DN group. Proliferation, assessed by Ki-67 labeling, increased upon NTCU treatment. The highest Ki-67 labeling index was seen in the DN group. As compared with SN mice, DN mice exhibited a three-fold increase (P < 0.005) in circulating white blood cells (WBC), a 20% (P < 0.05) increase in IL6 levels, and a four-fold (P < 0.005) increase in WBC in bronchial lavages. Thus, vitamin D repletion reduces the progression of premalignant lesions, proliferation, and inflammation, and may thereby suppress development of lung SCC. Further investigations of the chemopreventive effects of vitamin D in lung SCC are warranted.

MAC: identifying and correcting annotation for multi-nucleotide variations

Background

Next-Generation Sequencing (NGS) technologies have rapidly advanced our understanding of human variation in cancer. To accurately translate the raw sequencing data into practical knowledge, annotation tools, algorithms and pipelines must be developed that keep pace with the rapidly evolving technology. Currently, a challenge exists in accurately annotating multi-nucleotide variants (MNVs). These tandem substitutions, when affecting multiple nucleotides within a single protein codon of a gene, result in a translated amino acid involving all nucleotides in that codon. Most existing variant callers report a MNV as individual single-nucleotide variants (SNVs), often resulting in multiple triplet codon sequences and incorrect amino acid predictions. To correct potentially misannotated MNVs among reported SNVs, a primary challenge resides in haplotype phasing which is to determine whether the neighboring SNVs are co-located on the same chromosome.

Results

Here we describe MAC (Multi-Nucleotide Variant Annotation Corrector), an integrative pipeline developed to correct potentially mis-annotated MNVs. MAC was designed as an application that only requires a SNV file and the matching BAM file as data inputs. Using an example data set containing 3024 SNVs and the corresponding whole-genome sequencing BAM files, we show that MAC identified eight potentially mis-annotated SNVs, and accurately updated the amino acid predictions for seven of the variant calls.

Conclusions

MAC can identify and correct amino acid predictions that result from MNVs affecting multiple nucleotides within a single protein codon, which cannot be handled by most existing SNV-based variant pipelines. The MAC software is freely available and represents a useful tool for the accurate translation of genomic sequence to protein function.

Abstract LB-158: P73, a potential marker for chemoresponsiveness to cisplatin therapy and survival in muscle invasive bladder cancer (MIBC)

Intrinsic and/or acquired resistance to cisplatin is a major obstacle in the treatment of advanced bladder cancer (BC). It is important to find markers that predict tumor responsiveness to cisplatin-based chemotherapy. P73, a p53 homologue, plays an important role in cisplatin sensitivity. TAp73, a major isoform of p73, utilizes an extrinsic promoter (P1) and is pro-apoptotic. We utilized Illumina 450K methylation arrays to interrogate over 150 BC patient samples and found 9 distinct CpGs in the P1 promoter region that were hypermethylated in tumors compared to adjacent normal tissues (p&lt;.05). To determine the functional link between promoter methylation and transcriptional regulation of TAp73, we treated BC cell lines (253J, HT1376, and T24) with DNA hypomethylating agent decitabine (DAC) at various doses (0,1,5 μM). We found that a 10-20% decrease in methylation across 5 interrogated CpG sites resulted in a two fold increase in TAp73 expression. We hypothesize that demethylation of the P1 promoter increases TAp73 expression, sensitizing BC cells to cisplatin. To test this, T24 cells were pretreated with DAC (2μM), followed by cisplatin treatment (0.5μg/mL). Clonogenicity of T24 was measured, as well as changes in p73 methylation and expression. Results show a decrease in clonogenic potential following combination therapy. T24 treated with DAC alone or in combination with cisplatin showed a 15% decrease in P1 promoter methylation, while the same was not seen in cells treated with cisplatin alone. Treatment with DAC and cisplatin did not have a clear effect on TAp73 mRNA expression. We are investigating whether TAp73 protein expression reflects the effects of DAC. To determine the clinical value of TAp73 protein expression we utilized tissue microarrays (TMAs) of 354 BC patients. Immunohistochemical staining was assigned H-score indicating intensity of TAp73 expression and percentage of positive nuclei. Results showed lower TAp73 expression to be associated with patient samples of higher tumor grade and staging (p&lt;.001), suggesting that TAp73 expression is lost as the disease progresses from superficial to advanced BC. Consequently, low TAp73 protein expression was associated with shorter overall survival (p&lt;.05). To further investigate clinical utility of TAp73 promoter methylation and expression, we analyzed tumor samples from 24 patients treated with cisplatin in a neoadjuvant setting. Results showed hypermethylation in tumor compared with non-tumor samples (p&lt;.05), but no significant difference in mRNA expression was observed. Studies continue to focus on understanding the mechanism of cisplatin resistance in the context of epigenetic dysregulation and utilization of DAC as a potentiating agent of cispatin-based chemotherapy in muscle invasive BC.

Supported by NCI grants CA067267 and CA016056.

Citation Format: Rebecca D. Greenspan, Nithya Krishnan, Carl Morrison, Angela Omilian, Wiam Bshara, Amber Worral, Kristopher Attwood, Donald L. Trump, Anna Woloszynska-Read, Candace S. Johnson. P73, a potential marker for chemoresponsiveness to cisplatin therapy and survival in muscle invasive bladder cancer (MIBC). [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 LB-158. doi:10.1158/1538-7445.AM2015-LB-158

Abstract 5095: 1,25D3 inhibits migration and invasion through miR-101-3p in human bladder cancer cells

Bladder cancer is the fourth most common cancer diagnosed and eighth leading cause of cancer death in men. Metastasis is the primary reason for mortality. The 5-year survival rates for localized and metastatic bladder cancers are 94% and 6%, respectively. Therefore, more effective strategies to prevent and inhibit bladder cancer invasion and metastasis are needed to prolong survival. Epidemiological and experimental studies support a role for 1,25(OH) 2D3 (1,25D3) in cancer prevention and treatment. More recently, 1,25D3 has also been reported to inhibit tumor cell invasion and metastasis in several model systems. To study the anti-tumor effect of 1,25D3 in bladder cancer, we selected four human bladder cell lines including T24, 253J, 253J-BV and TCC-SUP cells. 253J-BV is a metastatic line generated from 253J cells through a series of orthotopic inoculation. Vitamin D receptor was expressed and induced by 1,25D3 in all four cell lines. However, treatment with 1,25D3 did not significantly affect the proliferation of the bladder cancer cell lines. To investigate the impact of 1,25D3 on bladder cancer cell migration and invasion, the cells were treated with control EtOH or 1,25D3 in the wound healing assay or chamber-based migration or invasion assays. 1,25D3 suppressed migration and invasion of 253J-BV and TCC-SUP cells but neither 253J nor T24 cells. MiRNAs play critical regulatory roles in cancer cell migration and invasion. We selected 253J and 253J-BV cells for further investigation of the role of miRNAs in 1,25D3 regulation of migration and invasion. Our previous PCR panel studies showed that 1,25D3 differentially regulated miRNA expression profiles in 253J and 253J-BV cells. From the markedly regulated miRNAs, we chose miR-101-3p and miR-126-3p to examine their potential contribution to the inhibition of migration and invasion by 1,25D3. 1,25D3 induced the expression of miR-101-3p and reduced miR-126-3p expression in 253J-BV cells but not 253J cells. To investigate the role of the two miRNAs, we employed pre-miR and miRNA inhibitors. Transfection with miR-101-3p inhibitor vector suppressed migration and invasion in 253J-BV cells. In addition, miR-101-3p inhibitor rescued 1,25D3-induced inhibition of migration and invasion in 253J-BV cells. On the other hand, pre-miR-101-3p transfection followed by 1,25D3 treatment resulted in further reduction of migration and invasion in 253J-BV cells. However, transfection with miR-126-3p inhibitor or pre-miR-126-3p did not alter 1,25D3-inhibition of migration and invasion in 253J-BV cells. These results indicate that 1,25D3 suppresses migration and invasion through the induction of miR-101-3p in human bladder cancer 253J-BV cells.

Citation Format: Yingyu Ma, Wei Luo, Rachel Pratt, Donald L. Trump, Candace S. Johnson. 1,25D3 inhibits migration and invasion through miR-101-3p in human bladder cancer cells. [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 5095. doi:10.1158/1538-7445.AM2015-5095

Abstract LB-039: 1,25 dihydroxyvitamin D3 and cisplatin combination modulate p73 in bladder cancer

Cisplatin-based combination chemotherapy is the standard approach to therapy of advanced bladder cancer. While there is a substantial initial response rate and occasional complete response, long term control is not common. There is a need to develop new therapeutic approaches to bladder cancer. 1,25 dihydroxyvitamin D3 (1,25D3), the active metabolite of vitamin D, enhances the anti-tumor effects of cisplatin in preclinical bladder cancer models. We evaluated the mechanism of 1,25D3 potentiation of cisplatin cytotoxicity through in vitro studies in bladder cancer cell lines. Our studies suggest that enhanced cytotoxicity is mediated through modulation of p73. The ratio of the pro-apoptotic TAp73 isoform to the anti-apoptotic ΔNp73 isoform is important in determining cellular response to cisplatin. Our studies demonstrate that pretreatment with 1,25D3 (0.5 uM) for 24 hrs followed by cisplatin (0.75 ug/ml) for 48 hrs increases the ratio of TA/ΔNp73 mRNA transcripts 2-fold in the T24 bladder cancer cell line, and increases TAp73's transcriptional target, BAX approximately 3-fold compared to cisplatin alone. Protein levels of p73 and BAX, are also increased with 1,25D3 pretreatment followed by cisplatin in T24 cells as determined by western blot. Using a TransAm p53 binding assay after p53 immunodepletion, cisplatin treatment was found to decrease TAp73 functional ability to bind DNA by approximately half, although this has not yet been determined to be statistically significant. 1,25D3 pretreatment followed by cisplatin prevents the decrease in TAp73 DNA binding found after cisplatin alone. These data suggest an increase in TAp73 pro-apoptotic functional abilities resulting from 1,25D3 pretreatment followed by cisplatin in T24 cells. These findings suggest that 1,25D3 may have potential to be used in combination with cisplatin to increase the apoptotic response. Further studies are being performed to determine the requirement of TAp73 in 1,25D3 potentiation of cisplatin cytotoxicity by using T24 cells transfected with TAp73 shRNA in assays previously used to determine synergism, ie. MTT, clonogenic, and apoptosis assays. Supported by NCI grants CA067267 and CA016056.

Citation Format: Brittany L. Bunch, Anna Woloszynska-Read, Donald L. Trump, Candace S. Johnson. 1,25 dihydroxyvitamin D3 and cisplatin combination modulate p73 in bladder 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 LB-039. doi:10.1158/1538-7445.AM2015-LB-039

Impact of Short-term 1,25-Dihydroxyvitamin D3 on the Chemopreventive Efficacy of Erlotinib against Oral Cancer

Activation of the epidermal growth factor receptor (EGFR) pathway is an early event in head and neck carcinogenesis. As a result, targeting EGFR for chemoprevention of head and neck squamous cell carcinomas (HNSCC) has received considerable attention. In the present study, we examined the impact of 1,25(OH)2D3, the active metabolite of the nutritional supplement vitamin D on the chemopreventive efficacy of the EGFR inhibitor, erlotinib, against HNSCC. Experimental studies were conducted in patient-derived xenografts (PDX) and the 4-nitroquinoline-1-oxide (4NQO) carcinogen-induced model of HNSCC. Short-term treatment (4 weeks) of PDX-bearing mice with 1,25(OH)2D3 and erlotinib resulted in significant inhibition of tumor growth. Noninvasive MRI enabled longitudinal monitoring of disease progression in the 4NQO model with 100% of control animals showing evidence of neoplastic lesions by 24 weeks. Among the experimental groups, animals treated with the combination regimen showed the greatest reduction in tumor incidence and volume (P < 0.05). Combination treatment was well tolerated and was not associated with any significant change in body weight. Histopathologic assessment revealed a significant reduction in the degree of dysplasia with combination treatment. Immunoblot analysis of whole tongue extracts showed downregulation of phospho-EGFR and phospho-Akt with the combination regimen. These results highlight the potential of 1,25(OH)2D3 to augment the efficacy of erlotinib against HNSCC. Further optimization of schedule and sequence of this combination regimen along with investigation into the activity of less calcemic analogues or dietary vitamin D is essential to fully realize the potential of this approach.

Association between Plasma 25-Hydroxyvitamin D, Ancestry and Aggressive Prostate Cancer among African Americans and European Americans in PCaP

BACKGROUND

African Americans (AAs) have lower circulating 25-hydroxyvitamin D3 [25(OH)D3] concentrations and higher prostate cancer (CaP) aggressiveness than other racial/ethnic groups. The purpose of the current study was to examine the relationship between plasma 25(OH)D3, African ancestry and CaP aggressiveness among AAs and European Americans (EAs).

METHODS

Plasma 25(OH)D3 was measured using LC-MS/MS (Liquid Chromatography Tandem Mass Spectrometry) in 537 AA and 663 EA newly-diagnosed CaP patients from the North Carolina-Louisiana Prostate Cancer Project (PCaP) classified as having either 'high' or 'low' aggressive disease based on clinical stage, Gleason grade and prostate specific antigen at diagnosis. Mean plasma 25(OH)D3 concentrations were compared by proportion of African ancestry. Logistic regression was used to calculate multivariable adjusted odds ratios (OR) and 95% confidence intervals (95%CI) for high aggressive CaP by tertile of plasma 25(OH)D3.

RESULTS

AAs with highest percent African ancestry (>95%) had the lowest mean plasma 25(OH)D3 concentrations. Overall, plasma 25(OH)D3 was associated positively with aggressiveness among AA men, an association that was modified by calcium intake (ORT 3vs.T1: 2.23, 95%CI: 1.26-3.95 among men with low calcium intake, and ORT 3vs.T1: 0.19, 95%CI: 0.05-0.70 among men with high calcium intake). Among EAs, the point estimates of the ORs were <1.0 for the upper tertiles with CIs that included the null.

CONCLUSIONS

Among AAs, plasma 25(OH)D3 was associated positively with CaP aggressiveness among men with low calcium intake and inversely among men with high calcium intake. The clinical significance of circulating concentrations of 25(OH)D3 and interactions with calcium intake in the AA population warrants further study.

1α,25(OH)2D3 differentially regulates miRNA expression in human bladder cancer cells

Bladder cancer is the fourth most commonly diagnosed cancer in men and eighth leading cause of cancer-related death in the US. Epidemiological and experimental studies strongly suggest a role for 1α,25(OH)2D3 in cancer prevention and treatment. The antitumor activities of 1α,25(OH)2D3 are mediated by the induction of cell cycle arrest, apoptosis, differentiation and the inhibition of angiogenesis and metastasis. miRNAs play important regulatory roles in cancer development and progression. However, the role of 1α,25(OH)2D3 in the regulation of miRNA expression and the potential impact in bladder cancer has not been investigated. Therefore, we studied 1α,25(OH)2D3-regulated miRNA expression profiles in human bladder cancer cell line 253J and the highly tumorigenic and metastatic derivative line 253J-BV by miRNA qPCR panels. 253J and 253J-BV cells express endogenous vitamin D receptor (VDR), which can be further induced by 1α,25(OH)2D3. VDR target gene 24-hydroxylase was induced by 1α,25(OH)2D3 in both cell lines, indicating functional 1α,25(OH)2D3 signaling. The miRNA qPCR panel assay results showed that 253J and 253J-BV cells have distinct miRNA expression profiles. Further, 1α,25(OH)2D3 differentially regulated miRNA expression profiles in 253J and 253J-BV cells in a dynamic manner. Pathway analysis of the miRNA target genes revealed distinct patterns of contribution to the molecular functions and biological processes in the two cell lines. In conclusion, 1α,25(OH)2D3 differentially regulates the expression of miRNAs, which may contribute to distinct biological functions, in human bladder 253J and 253J-BV cells. This article is part of a Special Issue entitled '17th Vitamin D Workshop'.

SCNVSim: somatic copy number variation and structure variation simulator

Background

Somatically acquired structure variations (SVs) and copy number variations (CNVs) can induce genetic changes that are directly related to tumor genesis. Somatic SV/CNV detection using next-generation sequencing (NGS) data still faces major challenges introduced by tumor sample characteristics, such as ploidy, heterogeneity, and purity. A simulated cancer genome with known SVs and CNVs can serve as a benchmark for evaluating the performance of existing somatic SV/CNV detection tools and developing new methods.

Results

SCNVSim is a tool for simulating somatic CNVs and structure variations SVs. Other than multiple types of SV and CNV events, the tool is capable of simulating important features related to tumor samples including aneuploidy, heterogeneity and purity.

Conclusions

SCNVSim generates the genomes of a cancer cell population with detailed information of copy number status, loss of heterozygosity (LOH), and event break points, which is essential for developing and evaluating somatic CNV and SV detection methods in cancer genomics studies.

Serum microRNA expression patterns that predict early treatment failure in prostate cancer patients

We aimed to identify microRNA (miRNA) expression patterns in the serum of prostate cancer (CaP) patients that predict the risk of early treatment failure following radical prostatectomy (RP). Microarray and Q-RT-PCR analyses identified 43 miRNAs as differentiating disease stages within 14 prostate cell lines and reflectedpublically available patient data. 34 of these miRNA were detectable in the serum of CaP patients. Association with time to biochemical progression was examined in a cohort of CaP patients following RP. A greater than two-fold increase in hazard of biochemical progression associated with altered expression of miR-103, miR-125b and miR-222 (p <.0008) in the serum of CaP patients. Prediction models based on penalized regression analyses showed that the levels of the miRNAs and PSA together were better at detecting false positives than models without miRNAs, for similar level of sensitivity. Analyses of publically available data revealed significant and reciprocal relationships between changes in CpG methylation and miRNA expression patterns suggesting a role for CpG methylation to regulate miRNA. Exploratory validation supported roles for miR-222 and miR-125b to predict progression risk in CaP. The current study established that expression patterns of serum-detectable miRNAs taken at the time of RP are prognostic for men who are at risk of experiencing subsequent early biochemical progression. These non-invasive approaches could be used to augment treatment decisions.

Abstract 238: Vitamin D sufficiency slows the progression of dysplasic lesions in the NTCU mouse model of lung squamous cell carcinoma

Progress has recently been made in identifying populations at risk for lung cancer using genetic, clinical and demographic information. The N-nitroso-tris-chloroethylurea (NTCU) mouse model, in which animals develop premalignant histopathology similar to that seen in humans, is used to examine the potential efficacy of chemoprevention agents to be utilized in at risk populations. We identified 25 µl of 40 mM NTCU /week as the optimal dosing regimen in SWR/J mice for chemoprevention studies.  At this dose, topical treatments of NTCU induce predominantly low-grade dysplastic lesions by 15 weeks (w) and high-grade dysplastic (HGD) lesions by 25 w in the large airways. Additionally we found that NTCU stimulates a state of chronic inflammation associated with the development of dysplasias.

Epidemiologic studies indicate that there is an inverse relationship between vitamin D and the risk and prognosis of lung cancer. Vitamin D acts through the vitamin D receptor to promote cellular differentiation and inhibit proliferation and inflammation. The effect of vitamin D on cancer progression was tested in the NTCU model, using dietary vitamin D3 (0 or 2000 IU/kg) alone and in combination with intraperitoneal injections of the active metabolite of vitamin D, calcitriol (80 ug/kg). Female mice were randomized to 6 treatment groups (n=15 mice/group/time point (15 and 25 w)). Disease was evaluated by enumerating the percentage of HGD lesions, per the total area in serial H&E sections of the lung. The percentage of HGD lesions in the large airways was reduced in the vitamin D sufficient mice (SN) (8.72%, P&lt;0.05), SN + calcitriol (SN+C) (6.59%, P&lt;0.05) and the vitamin D deficient + calcitriol (DN+C) (12.3% P&lt;0.05) groups compared to the DN (22.67%) group after 15 w of NTCU. The percentage of HGD lesions in the SN groups remained significantly less than the DN (35.5%) and DN+C (21.3%) groups, with little increase in the SN (8.43% P&lt;0.05) and SN+C (11.81% not significant (NS)) groups after 25 w.

Furthermore, there was a significant increase in proliferation associated with increased HGD. Following 25 w of NTCU treatment there was a 2-fold increase in Ki-67 staining all groups compared all groups after 15 w of NTCU. However, the was 30% more Ki-67staining in the DN (P&lt;0.001) group and addition of calcitriol reduced proliferation by 12% and 6% in the DN+C (P&lt;0.01) and SN+C (NS) groups. Moreover, vitamin D deficiency was associated with an increased systemic and local inflammation marked by a 3-fold increase in circulating white blood cells (WBCs) (P&lt;0.05), a 20% increase in IL-6 levels (P&lt;0.05) and a 4 -fold increase in WBCs in bronchial lavages (P&lt; 0.05) in the DN group. In conclusion this study indicates that vitamin D deficiency promotes the development of dysplasia, increases proliferation and inflammation, which is likely promote the development of frank squamous cell carcinoma. Supported by NIH/NCCAM F31AT0006487 (Mazzilli) NIH/NCI CA067267 (Johnson)  

Citation Format: Sarah A. Mazzilli, Mary E. Reid, Paul N. Bogner, Kristopher Attwood, Pamela A. Hershberger, Donald L. Trump, Candace S. Johnson. Vitamin D sufficiency slows the progression of dysplasic lesions in the NTCU mouse model of lung squamous cell carcinoma. [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 238. doi:10.1158/1538-7445.AM2014-238

Computational methods for detecting copy number variations in cancer genome using next generation sequencing: principles and challenges

Accurate detection of somatic copy number variations (CNVs) is an essential part of cancer genome analysis, and plays an important role in oncotarget identifications. Next generation sequencing (NGS) holds the promise to revolutionize somatic CNV detection. In this review, we provide an overview of current analytic tools used for CNV detection in NGS-based cancer studies. We summarize the NGS data types used for CNV detection, decipher the principles for data preprocessing, segmentation, and interpretation, and discuss the challenges in somatic CNV detection. This review aims to provide a guide to the analytic tools used in NGS-based cancer CNV studies, and to discuss the important factors that researchers need to consider when analyzing NGS data for somatic CNV detections.

Isolation and genome-wide expression and methylation characterization of CD31+ cells from normal and malignant human prostate tissue

Endothelial cells (ECs) are an important component involved in the angiogenesis. Little is known about the global gene expression and epigenetic regulation in tumor endothelial cells. The identification of gene expression and epigenetic difference between human prostate tumor-derived endothelial cells (TdECs) and those in normal tissues may uncover unique biological features of TdEC and facilitate the discovery of new anti-angiogenic targets. We established a method for isolation of CD31⁺ endothelial cells from malignant and normal prostate tissues obtained at prostatectomy. TdECs and normal-derived ECs (NdECs) showed >90% enrichment in primary culture and demonstrated microvascular endothelial cell characteristics such as cobblestone morphology in monolayer culture, diI-acetyl-LDL uptake and capillary-tube like formation in Matrigel^®. In vitro primary cultures of ECs maintained expression of endothelial markers such as CD31, von Willebrand factor, intercellular adhesion molecule, vascular endothelial growth factor receptor 1, and vascular endothelial growth factor receptor 2. We then conducted a pilot study of transcriptome and methylome analysis of TdECs and matched NdECs from patients with prostate cancer. We observed a wide spectrum of differences in gene expression and methylation patterns in endothelial cells, between malignant and normal prostate tissues. Array-based expression and methylation data were validated by qRT-PCR and bisulfite DNA pyrosequencing. Further analysis of transcriptome and methylome data revealed a number of differentially expressed genes with loci whose methylation change is accompanied by an inverse change in gene expression. Our study demonstrates the feasibility of isolation of ECs from histologically normal prostate and prostate cancer via CD31⁺ selection. The data, although preliminary, indicates that there exist widespread differences in methylation and transcription between TdECs and NdECs. Interestingly, only a small proportion of perturbed genes were overlapped between American (AA) and Caucasian American (CA) patients with prostate cancer. Our study indicates that identifying gene expression and/or epigenetic differences between TdECs and NdECs may provide us with new anti-angiogenic targets. Future studies will be required to further characterize the isolated ECs and determine the biological features that can be exploited in the prognosis and therapy of prostate cancer.

Combined effects of circulating levels of 25-hydroxyvitamin d and Th1 and th2 cytokines on breast cancer estrogen receptor status

Vitamin D has been recognized for its immune-modulating properties. We have previously found that levels of 25OHD, and cytokines including IL5, IFNα2, and TNFα, are also associated with estrogen receptor (ER) negative breast cancer in younger women. Thus, we hypothesized that there may be interactions between vitamin D and the immune system in influencing breast cancer ER status, which was tested in 490 women with incident breast cancer. There was no correlation of the levels of 25OHD with any cytokine, and their associations with tumor ER negative status were independent of each other. However, premenopausal women with low 25OHD and high TNFα levels had the highest likelihood of having ER negative cancer (odds ratio [OR] = 7.32, 95% confidence interval [CI] = 2.44-21.98), with evidence of synergy between the two (relative excess risk due to interaction [RERI] = 5.46, p for additive interaction = 0.14, and p for multiplicative interaction = 0.09). There were similar synergistic associations between 25OHD and IL5, and several IFNα2 to Th2 cytokine ratios. This is the first study to provide evidence of interactions between vitamin D and the immune system in relation to breast cancer ER status, which may inform combinational use of vitamin D and anti-inflammatory drugs for cancer prevention and therapy.

Low 25(OH) vitamin D3 levels are associated with adverse outcome in newly diagnosed, intensively treated adult acute myeloid leukemia

BACKGROUND

Several studies have suggested that low 25(OH) vitamin D3 levels may be prognostic in some malignancies, but no studies have evaluated their impact on treatment outcome in patients with acute myeloid leukemia (AML).

METHODS

Vitamin D levels were evaluated in 97 consecutive, newly diagnosed, intensively treated patients with AML. MicroRNA expression profiles and single nucleotide polymorphisms (SNPs) in the 25(OH) vitamin D3 pathway genes were evaluated and correlated with 25(OH) vitamin D3 levels and treatment outcome.

RESULTS

Thirty-four patients (35%) had normal 25(OH) vitamin D3 levels (32-100 ng/mL), 34 patients (35%) had insufficient levels (20-31.9 ng/mL), and 29 patients (30%) had deficient levels (<20 ng/mL). Insufficient/deficient 25(OH) vitamin D3 levels were associated with worse relapse-free survival (RFS) compared with normal vitamin D3 levels. In multivariate analyses, deficient 25(OH) vitamin D3 , smoking, European Leukemia Network genetic group, and white blood cell count retained their statistical significance for RFS. Several microRNAs and SNPs were associated with 25(OH) vitamin D3 levels, although none remained significant after multiple test corrections; one 25(OH) vitamin D3 receptor SNP, rs10783219, was associated with a lower complete remission rate (P = .0442) and with shorter RFS (P = .0058) and overall survival (P = .0011).

CONCLUSIONS

It remains to be determined what role microRNA and SNP profiles play in contributing to low 25(OH) vitamin D3 level and/or outcome and whether supplementation will improve outcomes for patients with AML.

Induction and Maintenance of Systemic Acquired Resistance by Acibenzolar-S-Methyl in Three Cultivated Tobacco Types

Induction and maintenance of systemic acquired resistance (SAR) in 'N' gene containing burley, flue-cured, and oriental tobacco cultivars were assessed by monitoring decreases in the number of local lesions caused by Tobacco mosaic virus (TMV) following treatment with acibenzolar-S-methyl (ASM). Leaf samples were collected from lower, middle, and top positions on seedlings at 3-day intervals over 21 days following ASM treatment and subsequent inoculation with TMV under laboratory conditions. Local lesion number for each leaf was recorded 7 days postinoculation. Reductions in TMV local lesion numbers on ASM-treated versus nontreated tobacco varied over time, and differed for each tobacco type. Based on reduced local lesion numbers, SAR was induced in burley and flue-cured tobacco by 3 and 6 days postinoculation, respectively, while oriental tobacco responded by 9 days. SAR was maintained in burley tobacco from 3 to 9 days after ASM application, and from 9 to 15 days after application in oriental tobacco. ASM treatment reduced local lesion numbers in flue-cured tobacco significantly at 6, 12, and 21 days postapplication, but not at 15 and 18 days after treatment. The SAR response was similar among lower, middle, and top leaves with no effect of ASM on response by leaf position, although TMV local lesion numbers were greater on lower leaves than on middle and top leaves 6 days after treatment, but significantly less on lower leaves 18 days after treatment compared to middle and top leaves.

24-Hydroxylase in cancer: impact on vitamin D-based anticancer therapeutics

The active vitamin D hormone 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) plays a major role in regulating calcium homeostasis and bone mineralization. 1,25(OH)2D3 also modulates cellular proliferation and differentiation in a variety of cell types. 24-Hydroxylase, encoded by the CYP24A1 gene, is the key enzyme which converts 1,25(OH)2D3 to less active calcitroic acid. Nearly all cell types express 24-hydroxylase, the highest activity being observed in the kidney. There is increasing evidence linking the incidence and prognosis of certain cancers to low serum 25(OH)D3 levels and high expression of vitamin D 24-hydroxylase, supporting the idea that elevated CYP24A1 expression may stimulate degradation of vitamin D metabolites including 25(OH)D3 and 1,25(OH)2D3. The over expression of CYP24A1 in cancer cells may be a factor affecting 1,25(OH)2D3 bioavailability and anti-proliferative activity pre-clinically and clinically. The combination of 1,25(OH)2D3 with CYP24A1 inhibitors enhances 1,25(OH)2D3 mediated signaling and anti-proliferative effects and may be useful in overcoming effects of aberrant CYP24A1 expression. This article is part of a Special Issue entitled 'Vitamin D Workshop'.

Role of androgen and vitamin D receptors in endothelial cells from benign and malignant human prostate

Forty years ago, Judah Folkman (Folkman. N Engl J Med 285: 1182-1186, 1971) proposed that tumor growth might be controlled by limiting formation of new blood vessels (angiogenesis) needed to supply a growing tumor with oxygen and nutrients. To this end, numerous "antiangiogenic" agents have been developed and tested for therapeutic efficacy in cancer patients, including prostate cancer (CaP) patients, with limited success. Despite the lack of clinical efficacy of lead anti-angiogenic therapeutics in CaP patients, recent published evidence continues to support the idea that prostate tumor vasculature provides a reasonable target for development of new therapeutics. Particularly relevant to antiangiogenic therapies targeted to the prostate is the observation that specific hormones can affect the survival and vascular function of prostate endothelial cells within normal and malignant prostate tissues. Here, we review the evidence demonstrating that both androgen(s) and vitamin D significantly impact the growth and survival of endothelial cells residing within prostate cancer and that systemic changes in circulating androgen or vitamin D drastically affect blood flow and vascularity of prostate tissue. Furthermore, recent evidence will be discussed about the expression of the receptors for both androgen and vitamin D in prostate endothelial cells that argues for direct effects of these hormone-activated receptors on the biology of endothelial cells. Based on this literature, we propose that prostate tumor vasculature represents an unexplored target for modulation of tumor growth. A better understanding of androgen and vitamin D effects on prostate endothelial cells will support development of more effective angiogenesis-targeting therapeutics for CaP patients.

Abstract LB-12: Plasma 25-hydroxyvitamin D levels are associated with aggressive prostate cancer among African Americans in the North Carolina-Louisiana Prostate Cancer Project (PCaP)

Background: Experimental and ecological studies support links between vitamin D and prostate cancer prevention and prognosis. Given the lower levels of circulating 25-hydroxyvitamin D [25(OH)D] and higher prostate cancer incidence and mortality among African Americans compared to other racial/ethnic groups, the aim of this investigation was to examine the relationship between plasma 25(OH)D levels and prostate cancer aggressiveness among African and European Americans.

Methods: Plasma 25(OH)D was measured using LC/MS/MS in 537 African Americans and 663 European Americans with newly-diagnosed prostate cancer from PCaP. Men were classified as cases (high aggressiveness) if Gleason sum ≥8, or PSA &gt;20 ng/ml, or Gleason sum ≥7 AND clinical stage = T3c-T4c, or Gleason sum=7 with primary pattern 4. The comparison group (low aggressiveness) included men with Gleason sum &lt;7 AND Stage T1-T2 AND PSA &lt; 9 ng/ml. Plasma 25(OH)D was categorized into tertiles in each race based on distributions among the comparison groups. Odds ratios (OR) and 95% confidence intervals (95%CI) were calculated for cases by tertile of plasma 25(OH)D using logistic regression with adjustment for potential confounders.

Results: African Americans had significantly lower mean concentrations of 25(OH)D (17.7 ± 7.6 ng/ml) compared to European Americans (24.6 ± 9.6 ng/ml). The highest tertile (mean=25.79 ng/ml & median=24.29 ng/ml) and middle tertile (mean=16.09 ng/ml & median=15.83) of plasma 25(OH)D were positively associated with highly aggressive prostate cancer among African Americans after adjustment for age, season, education, physical activity, smoking status, and PSA screening history (OR=1.7, 95% CI=1.0, 2.8 and OR=1.8, 95%CI=1.1, 3.0, respectively). No significant associations were observed for European American men.

Conclusions: Plasma 25(OH)D was positively associated with prostate cancer aggressiveness among African Americans but not European Americans, such that subjects with highly aggressive prostate cancer had increased odds of having higher plasma 25(OH)D levels. Research samples were collected after diagnosis, so effects of treatment, extent of disease or associated processes (e.g. weight loss) on plasma 25(OH)D may explain the findings. Ongoing studies include analysis of vitamin D binding protein (DBP) in the plasma and genotyping of DBP affinity variants in PCaP subjects. This approach may help explain the racial differences found, since DBP may modulate the impact of vitamin D status on prostate cancer.

Citation Format: Anna Woloszynska-Read, Lenore Arab, John Adams, Jeannette T. Bensen, Elizabeth TH Fontham, James L. Mohler, Joseph Su, Fred Tabung, Hongmei Zhang, Donald L. Trump, Candace S. Johnson, Susan E. Steck. Plasma 25-hydroxyvitamin D levels are associated with aggressive prostate cancer among African Americans in the North Carolina-Louisiana Prostate Cancer Project (PCaP). [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-12. doi:10.1158/1538-7445.AM2013-LB-12

Abstract 3434: Inecalcitol, an analogue of 1,25D3, displays enhanced antitumor activity through the induction of apoptosis in a squamous cell carcinoma model system

Epidemiological data suggest an important role of vitamin D signaling in cancer progression, and experimental studies demonstrate that the active vitamin D metabolite 1α, 25-dihydroxyvitamin D3 (1,25D3) has broad spectrum anti-tumor activity. Hypercalcemia has often been suggested to limit the clinical application of these data. The 14-epi-analog of 1,25D3, inecalcitol (19-nor-14-epi-23-yne-1,25-(OH)2D3; TX522), was developed to have superagonistic anti-tumor activities but low hypercalcemia potential. We examined the anti-tumor activity of inecalcitol and the underlying mechanisms in a murine squamous cell carcinoma (SCC) model system. Compared to 1,25D3, inecalcitol showed enhanced vitamin D receptor (VDR)-mediated transcriptional activity. Inecalcitol suppressed SCC cell proliferation in a dose dependent manner with an IC50 value 30 times lower than that of 1,25D3. Both inecalcitol and 1,25D3 induced a comparable level of G0/G1 cell cycle arrest in SCC cells. The level of apoptosis induced by inecalcitol was markedly higher than that of 1,25D3. Apoptosis was mediated through the activation of the caspase 8/10- caspase 3 pathway. Further, inecalcitol markedly inhibited the mRNA and protein expression of c-IAP1 and XIAP compared to 1,25D3. In vivo, inecalcitol inhibits SCC tumor growth at 80 μg dose without hypercalcemia. Inecalcitol (320 μg) or 1,25D3 (0.312 μg) markedly inhibited tumor growth. Notably, inecalcitol induced a significantly higher level of apoptosis in the SCC xenograft model. We show that inecalcitol has potent anti-tumor activity in the SCC model system and this is associated with a stronger induction of apoptosis. These findings support the further development of inecalcitol in cancer treatment.

Citation Format: Yingyu Ma, Wei-Dong Yu, Alejandro A. Hidalgo, Wei Luo, Remi Delansorne, Candace S. Johnson, Donald L. Trump. Inecalcitol, an analogue of 1,25D3, displays enhanced antitumor activity through the induction of apoptosis in a squamous cell carcinoma model system. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3434. doi:10.1158/1538-7445.AM2013-3434

Serum vitamin D metabolites in colorectal cancer patients receiving cholecalciferol supplementation: correlation with polymorphisms in the vitamin D genes

Cholecalciferol (D₃) supplementation results in variable increases in serum 25(OH)D₃ levels, however, the influence of genetic polymorphisms on these variable responses is unclear. We measured serum 25(OH)D₃, 24,25(OH)₂D_3, 1,25(OH)₂D₃ and VDBP levels in 50 colorectal cancer (CRC) patients before and during 2,000 IU daily oral D₃ supplementation for six months and in 263 archived CRC serum samples. Serum PTH levels and PBMC 24-OHase activity were also measured during D₃ supplementation. TagSNPs in CYP2R1, CYP27A1, CYP27B1, CYP24A1, VDR, and GC genes were genotyped in all patients, and the association between these SNPs and serum vitamin D₃ metabolites levels before and after D₃ supplementation was analyzed. The mean baseline serum 25(OH)D₃ level was less than 32 ng/mL in 65 % of the 313 CRC patients. In the 50 patients receiving D₃ supplementation, serum levels of 25(OH)D₃ increased (p = 0.008), PTH decreased (p = 0.036) and 24,25(OH)₂D₃, 1,25(OH)₂D₃, VDBP levels and PBMC 24-OHase activity were unchanged. GC SNP rs222016 was associated with high 25(OH)D₃ and 1,25(OH)₂D₃ levels at baseline while rs4588 and rs2282679 were associated with lower 25(OH)D₃ and 1,25(OH)₂D₃ levels both before and after D₃ supplementation. CYP2R1 rs12794714 and rs10500804 SNPs were significantly associated with low 25(OH)D₃ levels after supplementation but not with baseline 25(OH)D₃. Our results show that D₃ supplementation increased 25(OH)D₃ levels in all patients. GC rs4588 and rs2283679 SNPs were associated with increased risk of vitamin D₃ insufficiency and suboptimal increase in 25(OH)D₃ levels after D₃ supplementation. Individuals with these genotypes may require higher D₃ supplementation doses to achieve vitamin D₃ sufficiency.

A phase I/II pharmacokinetic and pharmacogenomic study of calcitriol in combination with cisplatin and docetaxel in advanced non-small-cell lung cancer

BACKGROUND

Preclinical studies demonstrated antiproliferative synergy of 1,25-D3 (calcitriol) with cisplatin. The goals of this phase I/II study were to determine the recommended phase II dose (RP2D) of 1,25-D3 with cisplatin and docetaxel and its efficacy in metastatic non-small-cell lung cancer.

METHODS

Patients were ≥18 years, PS 0-1 with normal organ function. In the phase I portion, patients received escalating doses of 1,25-D3 intravenously every 21 days prior to docetaxel 75 mg/m(2) and cisplatin 75 mg/m(2) using standard 3 + 3 design, targeting dose-limiting toxicity (DLT) rate <33 %. Dose levels of 1,25-D3 were 30, 45, 60, and 80 mcg/m(2). A two-stage design was employed for phase II portion. We correlated CYP24A1 tagSNPs with clinical outcome and 1,25-D3 pharmacokinetics (PK).

RESULTS

34 patients were enrolled. At 80 mcg/m(2), 2/4 patients had DLTs of grade 4 neutropenia. Hypercalcemia was not observed. The RP2D of 1,25-D3 was 60 mcg/m(2). Among 20 evaluable phase II patients, there were 2 confirmed, 4 unconfirmed partial responses (PR), and 9 stable disease (SD). Median time to progression was 5.8 months (95 % CI 3.4, 6.5), and median overall survival 8.7 months (95 % CI 7.6, 39.4). CYP24A1 SNP rs3787554 (C > T) correlated with disease progression (P = 0.03) and CYP24A1 SNP rs2762939 (C > G) trended toward PR/SD (P = 0.08). There was no association between 1,25-D3 PK and CYP24A1 SNPs.

CONCLUSIONS

The RP2D of 1,25-D3 with docetaxel and cisplatin was 60 mcg/m(2) every 21 days. Pre-specified endpoint of 50 % confirmed RR was not met in the phase II study. Functional SNPs in CYP24A1 may inform future studies individualizing 1,25-D3.

Inecalcitol, an analog of 1,25D3, displays enhanced antitumor activity through the induction of apoptosis in a squamous cell carcinoma model system

Epidemiological data suggest an important role of vitamin D signaling in cancer development and progression, and experimental studies demonstrate that the active vitamin D metabolite 1α, 25-dihydroxyvitamin D₃ (1,25D₃) has broad spectrum antitumor activity. Hypercalcemia has often been suggested to limit the clinical application of these data. The 14-epi-analog of 1,25D₃, inecalcitol [19-nor-14-epi-23-yne-1,25-(OH)₂D₃; TX522], was developed to have superagonistic antitumor activities but low hypercalcemia potential. We examined the antitumor activity of inecalcitol and the underlying mechanisms in a murine squamous cell carcinoma (SCC) model system. In vitro, compared with 1,25D₃, inecalcitol showed enhanced vitamin D receptor (VDR)-mediated transcriptional activity. Inecalcitol suppressed SCC cell proliferation in a dose-dependent manner with an IC50 value 30 times lower than that of 1,25D₃. Both inecalcitol and 1,25D₃ induced a comparable level of G0/G₁ cell cycle arrest in SCC cells. The level of apoptosis induced by inecalcitol was markedly higher than that of 1,25D₃. Apoptosis was mediated through the activation of the caspase 8/10- caspase 3 pathway. Further, inecalcitol markedly inhibited the mRNA and protein expression of c-IAP1 and XIAP compared with 1,25D₃. In vivo, inecalcitol inhibits SCC tumor growth in a dose-dependent fashion. Notably, inecalcitol induced a significantly higher level of apoptosis in the SCC xenograft model. While in vitro inecalcitol demonstrates apparent enhanced VDR binding and antiproliferative effects compared to 1,25D₃, in vivo these advantages disappear; at doses of inecalcitol that have equivalent antitumor effects, similar hypercalcemia is seen. This may be explained by the pharmacokinetics of 1,25D₃ vs. inecalcitol and attributed to the much shorter serum half-life of inecalcitol.We show that inecalcitol has potent antitumor activity in the SCC model system, and this is associated with a strong induction of apoptosis. These findings support the further development of inecalcitol in cancer treatment.

Inhibition of protein kinase CK2 reduces Cyp24a1 expression and enhances 1,25-dihydroxyvitamin D(3) antitumor activity in human prostate cancer cells

Vitamin D has broad range of physiological functions and antitumor effects. 24-Hydroxylase, encoded by the CYP24A1 gene, is the key enzyme for degrading many forms of vitamin D including the most active form, 1,25D(3). Inhibition of CYP24A1 enhances 1,25D(3) antitumor activity. To isolate regulators of CYP24A1 expression in prostate cancer cells, we established a stable prostate cancer cell line PC3 with CYP24A1 promoter driving luciferase expression to screen a small molecular library for compounds that inhibit CYP24A1 promoter activity. From this screening, we identified, 4,5,6,7-tetrabromobenzimidazole (TBBz), a protein kinase CK2 selective inhibitor as a disruptor of CYP24A1 promoter activity. We show that TBBz inhibits CYP24A1 promoter activity induced by 1,25D(3) in prostate cancer cells. In addition, TBBz downregulates endogenous CYP24A1 mRNA level in TBBz-treated PC3 cells. Furthermore, siRNA-mediated CK2 knockdown reduces 1,25D(3)-induced CYP24A1 mRNA expression in PC3 cells. These results suggest that CK2 contributes to 1,25D(3)-mediated target gene expression. Finally, inhibition of CK2 by TBBz or CK2 siRNA significantly enhances 1,25D(3)-mediated antiproliferative effect in vitro and in vivo in a xenograft model. In summary, our findings reveal that protein kinase CK2 is involved in the regulation of CYP24A1 expression by 1,25D(3) and CK2 inhibitor enhances 1,25D(3)-mediated antitumor effect.

OSAT: a tool for sample-to-batch allocations in genomics experiments

Background

Batch effect is one type of variability that is not of primary interest but ubiquitous in sizable genomic experiments. To minimize the impact of batch effects, an ideal experiment design should ensure the even distribution of biological groups and confounding factors across batches. However, due to the practical complications, the availability of the final collection of samples in genomics study might be unbalanced and incomplete, which, without appropriate attention in sample-to-batch allocation, could lead to drastic batch effects. Therefore, it is necessary to develop effective and handy tool to assign collected samples across batches in an appropriate way in order to minimize the impact of batch effects.

Results

We describe OSAT (Optimal Sample Assignment Tool), a bioconductor package designed for automated sample-to-batch allocations in genomics experiments.

Conclusions

OSAT is developed to facilitate the allocation of collected samples to different batches in genomics study. Through optimizing the even distribution of samples in groups of biological interest into different batches, it can reduce the confounding or correlation between batches and the biological variables of interest. It can also optimize the homogeneous distribution of confounding factors across batches. It can handle challenging instances where incomplete and unbalanced sample collections are involved as well as ideally balanced designs.

Abstract B33: Genome-wide methylation analyses reveal racial differences in blood DNA of prostate cancer patients from the North Carolina-Louisiana Prostate Cancer Project (PCaP) cohort

Epigenetic aberrations occur early in prostate carcinogenesis and contribute to disease progression. African American men experience the highest incidence and mortality from prostate cancer among all groups of men in the US. However, the role of epigenetics in prostate cancer health disparities in African American men has not been investigated thoroughly. Although prostate cancer health disparities are complex phenomena, evidence exists that biological mechanisms contribute to disparity. DNA methylation plays an important role in prostate cancer etiology and progression. Environment-gene interactions may differ between racial groups, in turn leading to variably altered methylomes. Genome-wide investigation of epigenetic variation between African Americans and European Americans may contribute to an understanding of the underlying mechanisms of these health disparities and help identify novel biomarkers of aggressive prostate cancer. We performed a pilot, new generation genome-wide DNA methylation profiling of peripheral blood cell (PBC) DNA from fourteen African Americans and twelve European Americans from the North Carolina-Louisiana Prostate Cancer Project (PCaP) cohort who were matched by age and disease stage. We utilized 450K Illumina methylation array for our studies. Interestingly, we found that African Americans and European Americans are separated into two distinct DNA methylation subgroups using a model-based cluster analysis. Global methylation analysis showed patterns of hypermethylation in African Americans when compared to European Americans, most significantly evident in non-CpG island promoter regions. We then examined gene candidates that were previously implicated in prostate cancer or differentially methylated in normal prostate tissues in African Americans versus European Americans. We identified several genes (e.g., NKX2, RAR-β, and TIMP3) with significant promoter DNA hypermethylation in African Americans when compared to European Americans; this suggests that PBC DNA may in part recapitulate methylation patterns seen in prostate tissue. Our findings demonstrate that racial differences in methylation patterns exist in the blood DNA of prostate cancer patients, which supports the concept that environment-gene interactions might differ among racial and ethnic groups. Furthermore, our findings suggest that future studies should take racial differences into account when searching for blood-based methylation biomarkers. Our ongoing work will explore whether such differences relate to more aggressive disease and poorer prostate cancer outcomes in African Americans when compared to men of European ancestry. (Funded by a grant to AWR from the DoD W81XWH1110308).

Citation Format: Anna Woloszynska-Read, Dan Wang, Song Liu, James L. Mohler, Donald L. Trump, Candace S. Johnson. Genome-wide methylation analyses reveal racial differences in blood DNA of prostate cancer patients from the North Carolina-Louisiana Prostate Cancer Project (PCaP) cohort. [abstract]. In: Proceedings of the Fifth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2012 Oct 27-30; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2012;21(10 Suppl):Abstract nr B33.

Regulation of motility, invasion, and metastatic potential of squamous cell carcinoma by 1α,25-dihydroxycholecalciferol

BACKGROUND

The active metabolite of vitamin D 1α,25-dihydroxycholecalciferol (1,25D(3) ) has exhibited broad-spectrum antitumor activity in xenograft animal models. However, its activity against metastatic disease has not been extensively investigated.

METHODS

Squamous cell carcinoma (SCC) or 1,25D(3) -resistant variant SCC-DR cells were treated with 1,25D(3) . Actin organization was examined by immunofluorescence assay. Cell migration was assessed by "wound" healing and chemotactic migration assays. Cell invasion was assessed by a Matrigel-based invasion assay and in situ zymography. Matrix metalloproteinase 2 (MMP-2) and MMP-9 expression and secretion were examined by immunoblot analysis and an enzyme-linked immunosorbent assay, respectively. E-cadherin expression was assessed by flow cytometry, immunoblot analysis, and immunohistochemistry. Knockdown of E-cadherin was achieved by small interfering RNA. An experimental metastasis mouse model was created by intravenous injection of tumor cells; and lung tumor development in the mice was assessed by magnetic resonance imaging, gross observation, and histology.

RESULTS

SCC cellular morphology and actin organization were altered by 10 nM 1,25D(3) . 1,25D(3) inhibited SCC cell motility and invasion, which were associated with reduced expression and secretion of MMP-2 and MMP-9, and 1,25D(3) promoted the expression of E-cadherin. These findings were not observed in SCC-DR cells. Knock down of E-cadherin rescued 1,25D(3) -inhibited cell migration. Intravenous injection of SCC or SCC-DR cells resulted in the establishment of extensive pulmonary lesions in saline-treated C3H mice. Treatment with 1,25D(3) resulted in a marked reduction in the formation of lung tumor colonies in mice that were injected with SCC cells, but not in mice that were injected with SCC-DR cells.

CONCLUSIONS

1,25D(3) suppressed SCC cell motility, invasion, and metastasis, partially through the promotion of E-cadherin-mediated cell-cell adhesion.

A phase I/II clinical trial of intravenous (I.V.) calcitriol with fixed doses of cisplatin and docetaxel in advanced non-small cell lung cancer

e18118

Background: In vitro and in vivo studies have demonstrated the antiproliferative effects of 1, 25 (OH)2D3 (calcitriol) as single agent and antitumor synergy with cisplatin. The goals of this Phase I/II study were to determine the maximum tolerated dose (MTD) of 1, 25 (OH)2 D3 in combination with cisplatin and docetaxel, and to evaluate the efficacy in patients (pts) with metastatic NSCLC.Methods: The study was a multicenter, open-label study in pts with metastatic NSCLC. Pts were adults 18 yrs., PS 0-1 with normal liver/kidney function. For the phase I study, pts (3–6 per cohort) received 1, 25 (OH)2 D3 I.V. every 21 days prior to docetaxel and cisplatin. The starting dose of 1,25 (OH)2D3 was 15 mcg/m2 at sequential ascending dose levels (DL) (15, 30, 60 and 80 mcg/m2) using a 3+3 design targeting a dose-limiting toxicity (DLT) rate of <33%. Docetaxel was administered at 75 mg/m2 and cisplatin 75mg/m2 following 1, 25 (OH)2 D3 for 4 cycles. We analyzed SNPs in the CYP24A1 gene.Results: 37 pts were enrolled (16 in phase I and 21 in phase II) with a median age of 54 (range 34–79) yrs.; M: F, 12:17. At the 80 mcg/m2 dose level, 2/4 pts had DLT of grade 4 neutropenia. There were no cases of hypercalcemia or azotemia. The MTD and recommended Phase II dose was 60 mcg/m2. Among 6 response-evaluable Phase I pts, and 21 phase II pts, there were: 2 confirmed partial responses (PR), 6 unconfirmed PRs and 10 pts with stable disease. The median time to progression was 6.9 months (95% CI 4.4, 12.9) and the median overall survival was 8.3 months (95% CI 5.8, 14.9). Of the CYP24A1 SNPs, the IVS4-308C>G was associated with progressive disease (Chi-Square=0.0062)Conclusions: The MTD of 1,25 (OH)2D3 in combination with docetaxel and cisplatin was 60 mcg/m2 IV every 21 days. Pre-specified endpoint of a 50% response rate was not met in the phase II study. However, disease control in 66% of patients argues for further study of 1,25 (OH)2D3 as maintenance therapy. The CYP24A1 polymorphism IVS4-308C>G may be associated with resistance to a 1,25 (OH)2D3 based therapeutic regimen