Exposure of environmental trace elements in prostate cancer patients: A multiple metal analysis

Prostate cancer (PCa) is the second leading cause of cancer-related deaths among men. To elucidate the connection between trace elements (arsenic: As, cadmium: Cd, lead: Pb, chromium: Cr, and nickel: Ni) and the risk of PCa, we analyzed trace element levels in the serum, urine, and tissues of PCa patients, while also examining their smoking status. We correlated these levels with their smoking habits. Notably, levels of Cd (P ≤ 0.05) and As (P ≤ 0.01) were significantly higher in the tumor tissue than in adjacent tissues. No significant differences were observed in the levels of Pb, Cr and Ni. Additionally, urinary Cd levels in 70% and arsenic levels in 2.3% of the PCa cohort were markedly higher than the CDC-reported cutoff (Cd ≤ 0.185 μg/L & As ≤100 μg/L). None displayed elevated levels of urinary Pb, Cr, and Ni. Conversely, in serum samples, the concentration of arsenic exceeded the CDC-determined limit (As ≤1.0 μg/L) in 31.69% of PCa patients. However, only 7.04% of patients had higher serum Cd levels than the CDC standard values (Cd ≤ 0.315 μg/L), while all PCa patients exceeded the Cr CDC limit (Cr ≤ 0.16 μg/L) and the Ni CDC limit (Ni ≤ 0.2 μg/L). On the contrary, no significant differences were observed in serum Pb (Pb ≤ 35.0 μg/L). Our findings establish a positive link between Cd and arsenic tissue concentrations and the risk of PCa. Subsequent studies are essential to determine whether elevated trace element levels pose a risk for the development of prostate carcinogenesis. Interestingly, among the PCa cohort comprising smokers, notably higher Cd levels were observed only in tumor tissues (P ≤ 0.01) and urine (P ≤ 0.05) compared to other elements or in other specimens.

Identification of risk factors and prediction models for secondary malignant neoplasms (SMNs)-free survival and SMNs-specific survival in testicular cancer survivors

OBJECTIVE

This research endeavored to determine the key demographic and pathological factors tied to secondary malignant neoplasms (SMNs) in survivors of testicular cancer and to develop a predictive model.

METHOD

A total of 53,309 testicular cancer patients from the SEER national database (1975-2016) were included in our analysis. The primary outcome measured was SMNs-free survival, defined as the duration from testicular cancer diagnosis to the detection of a non-testicular malignancy. The secondary outcome was SMN-specific survival, defined as the period from testicular cancer diagnosis until the patient's death due to SMNs.

FINDINGS

Of the patients in the SEER cohort, 2978 (5.6%) developed non-testicular cancer SMNs. Higher age, receipt of chemotherapy, and radiation treatment were all significantly associated with the development of SMNs in survivors of testicular cancer (all p < 0.001). Kaplan-Meier analysis revealed a worse SMNs-free survival and poor SMN-specific survival in patients who underwent radiation therapy (both p < 0.001). Multivariable Cox regression analysis found non-Hispanic Black ethnicity, higher age, chemotherapy, and radiation therapy to be significantly associated with worse SMNs-free survival (p = 0.002, p < 0.001, p < 0.001, and p < 0.001, respectively), while lymphoma histology was associated with better SMNs-free survival (p < 0.001). The most common SMN types in patients receiving radiation therapy were prostate, lung, and bladder cancers. Predictive nomograms for SMNs-free survival and SMNs-specific survival were developed, with a C-index of 0.776 and 0.824, respectively.

CONCLUSION

The age of diagnosis, non-Hispanic Black ethnicity, lymphoma histology, and treatment history with chemotherapy and radiation therapy were identified as prognostic factors for SMNs-free survival.

Molecular interplay between NOX1 and autophagy in cadmium-induced prostate carcinogenesis

Chronic exposure to cadmium (Cd), a class I carcinogen, leads to malignant transformation of normal prostate epithelial cells (RWPE-1). The constant generation of Cd-induced ROS and resulting ER stress induces cellular responses that are needed for cell survival, and autophagy has an important role in this process. However, the mechanisms that regulate Cd-induced ROS and how these differ in terms of acute and chronic cadmium exposure remain unexplained. Here, we show that acute or chronic Cd exposure facilitates NOX1 assembly by activating its cytosolic regulators p47phox and p67phox in RWPE-1 cells. Upregulation of NOX1 complex proteins and generation of ROS activates unfolded protein response (UPR) via phosphorylation of protein kinase RNA-like endoplasmic reticulum kinase (PERK), eukaryotic initiation factor 2 alpha (eIF2α), and selective translation of activating transcription factor 4 (ATF4). Chronic Cd exposure constantly activates NOX1 complex and generates consistent ROS and ER stress that led to defective autophagy, wherein ATG5 expression is downregulated in contrast to acute Cd exposure. As a result, selective/defective autophagy creates depletion of autophagosome-lysosome fusion that gives a survival advantage to transforming cells, which is not available to RWPE-1 cells acutely exposed to Cd. Knockdown of key molecules in a lockstep manner directly affects the most downstream autophagy pathways in transforming cells. Overall, this study demonstrates that assembly of NOX1 complex proteins is indispensable for Cd-induced persistent ROS and controls ER stress-induced defective autophagy in mice and humans.

Urolithin A analog inhibits castration-resistant prostate cancer by targeting the androgen receptor and its variant, androgen receptor-variant 7

We investigated the efficacy of a small molecule ASR-600, an analog of Urolithin A (Uro A), on blocking androgen receptor (AR) and its splice variant AR-variant 7 (AR-V7) signaling in castration-resistant prostate cancer (CRPC). ASR-600 effectively suppressed the growth of AR+ CRPC cells by inhibiting AR and AR-V7 expressions; no effect was seen in AR- CRPC and normal prostate epithelial cells. Biomolecular interaction assays revealed ASR-600 binds to the N-terminal domain of AR, which was further confirmed by immunoblot and subcellular localization studies. Molecular studies suggested that ASR-600 promotes the ubiquitination of AR and AR-V7 resulting in the inhibition of AR signaling. Microsomal and plasma stability studies suggest that ASR-600 is stable, and its oral administration inhibits tumor growth in CRPC xenografted castrated and non-castrated mice. In conclusion, our data suggest that ASR-600 enhances AR ubiquitination in both AR+ and AR-V7 CRPC cells and inhibits their growth in vitro and in vivo models.

Abstract 3998: Discovery of a small molecule inhibitor for triple-negative breast cancer (TNBC)

Introduction: Little progress has been made towards developing alternative therapeutic strategies for triple-negative breast cancer (TNBC). Aberrant Notch1 activation, particularly in breast cancer stem cells (BCSCs) in TNBC tumors, enhances this cancer's aggressivity and resistance and consequently contributes to the poor overall survival of patients with TNBC. In contrast, inhibition of Notch1 has been shown to suppress TNBC growth. Thus, Notch1 presents as an attractive target for inhibiting TNBC growth. This study aims to overcome the limitations of current Notch1 inhibitors and identify a more specific inhibitor.

Methods: Small molecule screening was performed using structure-activity relationship (SAR) studies, and molecular docking and isothermal calorimetric (ITC) assays were used to determine the target sites of our rationally designed Notch1 inhibitor on the Notch1 receptor. The therapeutic potential of the identified small molecule Notch1 inhibitor was determined on BCSC and TNBC (ALDH+, BCSC, ALDH-, MDA-MB-231) cell lines using molecular studies and in vivo assays.

Results: We identified ASR490, a small molecule that binds to the NRR (the activation switch of the Notch receptor) of Notch1. Molecular docking studies indicated a strong interaction between ASR490 and the NRR domain with binding energy of -52.55 kcal/mol. Residue-wise interaction analysis estimated three hydrogen-bond interactions between ASR490 and NRR residues Asn-1483, Glu-1673, and Gly-1664 mediated by water molecules. The finding was further confirmed using biophysical assays (thermal shift assay and isothermal calorimetric analysis) using recombinant Notch1 protein. In vitro results demonstrated that ASR490 significantly inhibited TNBC growth (p &lt;0.001) at nM concentrations, with an IC50 of 760 nM at 24h. Further, the inhibitory effect was confirmed by TNBC’s colony-forming abilities. Western blot analysis confirmed that ASR490 downregulated the expressions of NICD (the active form of Notch1) and its downstream effectors Hey-1 and HES1 by ubiquitinating NRR of Notch1. ASR490 was found to be non-toxic to healthy cells. Moreover, ASR490 exhibited a maximum tolerated dose of more than 100 mg/kg body weight in mice and abrogated TNBC tumor growth in vivo xenograft models.

Conclusion: Our results demonstrate ASR490 as a potential therapeutic agent that abolishes Notch1 signaling in TNBC and BCSCs by specifically targeting Notch1 NRR. Further investigation is required for the clinical translational potential of this agent.

Citation Format: Uttara Saran, Balaji Chandrasekaran, Ashish Tyagi, Amandeep Singh, Murali K. Ankem, Arun K. Sharma, Chendil Damodaran. Discovery of a small molecule inhibitor for triple-negative breast cancer (TNBC) [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 3998.

Abstract 425: Selective ubiquitination of androgen receptor and its splice variants inhibits castration resistant prostate cancer

Introduction: The primary driver of castration-resistant prostate cancer (CRPC) is the Androgen receptor (AR). Drugs such as Abiraterone or Enzalutamide that target the Ligand Binding Domain (LBD) of AR are largely ineffective on AR splice variants (AR-SVs) that lack LBD and retain the N-terminal Domain (NTD) of AR. AR continues to function through other stimuli (ex: growth factors), leading to disease relapse and progression. Moreover, AR-SVs are known to heterodimerize with AR full length (AR-FL). Hence, treatment strategies that target both AR-FL and AR-NTD are needed for the complete remission of CRPC. Through structure-activity relationship (SAR) studies based on naturally occurring Urolithin A (UroA) structure, we have developed a novel small molecule UroBoc that directly binds to the NTD and inhibits CRPC growth.

Methods: To analyze the binding of UroBoc to AR-NTD, we performed differential scanning fluorimetry and measured saturation transfer difference (STD) in NMR spectroscopic studies. In addition, we investigated the effect of UroBoc on CRPC by western blotting, immunofluorescence, Immunoprecipitation, and performed Xenograft studies in castrated/non-castrated mice models.

Results: UroBoc treatment shifted the melt temperature (ΔTm) of purified NTD by 12-15 °C (median of 13.5 °C) in differential scanning fluorimetry. Moreover, STD effects observed were 30-18%, indicating a significant binding to NTD in our NMR studies. UroBoc inhibits the growth of AR+ CRPC, including enzalutamide resistant cells, at 800nM concentration, which is 40 times lower than that of the parent compound, UroA. At this concentration, UroBoc is non-toxic to normal prostate epithelial cells or other cancer cells. Interestingly, UroBoc also inhibited AR, AR-SV and PSA expressions in AR-FL (LNCaP, C42B) and AR-V7 (22-RV1) CRPC cell lines. Molecular studies suggested that UroBoc selectively promotes ubiquitination and subsequent degradation of AR and AR-V7 by proteasome activation. Remarkably, UroBoc failed to inhibit AKT, mTOR, PTEN and hormonal receptors such as estrogen and progesterone receptors suggesting AR could be a direct target for UroBoc. Further, in vivo studies revealed that oral administration of UroBoc inhibits tumor growth in CRPC in both castrated and non-castrated mice models.

Conclusion: Our results suggest that the novel UroBoc selectively degrades AR, AR-SV and overcomes enzalutamide resistance in preclinical CRPC models. We believe performing PK/PD studies will confirm the translation potential of UroBoc as a therapy for CRPC.

Citation Format: Ashish Tyagi, Balaji Chandrasekaran, Uttara Saran, Murali K. Ankem, Nikolay Dokholyan, Jyh M. Lin, Arun K. Sharma, Chendil Damodaran. Selective ubiquitination of androgen receptor and its splice variants inhibits castration resistant prostate 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 425.

Abstract 745: Molecular landscape of arsenic-induced bladder carcinogenesis

Introduction: Epidemiological, pre-clinical, and clinical studies have linked chronic arsenic (sodium arsenite: NaAsO2) exposure to a myriad of adverse health dysfunctions including the development of bladder cancer (BCa). However, most of the studies on arsenic-induced BCa have been performed on either unsuitable cell lines or using a higher concentration of arsenic (mM), which does not reflect exposure levels in a real-world setting. We used the telomerase reverse transcriptase (HU-hTERT1) immortalized normal bladder epithelial and a median physiological concentration of NaAsO2 (250 nM: 33 mg/L), to determine the transcriptomic and phenotypic changes during malignant transformation of HU-hTERT1 cells.

Methods: HU-hTERT1 cells were exposed to 250nM arsenic for 12 months. To analyze the effect of arsenic exposure we performed cell viability, cellular proliferation, and clonogenic assays. RNA Seq data was used to perform pathway enrichment analysis, Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, and protein-protein interaction (PPI) studies.

Results: BCa patients had significantly higher (4-5 fold) levels of arsenic (20-50 mg/L) in their urine when compared to their healthy counterparts (&lt;8 mg/L). Acute exposure to high concentration of (&gt; 400nM) inhibited the HU-hTERT1 growth, whereas concentrations less than 400nM did not adversely affect the viability of these cells. HU-hTER1 cells began forming colonies after six months of chronic NaAsO2 exposure, with the number of colonies increasing concurrently with the exposure time. GO and KEGG analysis showed a total of 2174 genes that are differentially expressed in arsenic-treated HU-hTER1 transforming cells (0 vs 12 months). The upregulated genes (1392) were involved in cellular response to unfolded protein, response to endoplasmic reticulum stress, proteasome-mediated ubiquitin-dependent protein degradation, autophagy signaling, and tumor angiogenesis(P&lt;0.05). Interestingly, the PPI analysis demonstrated a significant upregulation in histone modification of genes. These genes were enriched for the binding sites of transcription factors that are key regulators of carcinogenic pathways including ataxia-telangiectasia mutated (ATM) kinase and cell cycle regulatory pathways demonstrating a novel link between NaAsO2 exposure and BCa.

Conclusion: An in vitro model of NaAsO2-induced malignant transformation was developed. Identifying precise molecular events that lead to arsenic-induced malignant transformation of normal urothelial cells would be an important step in defining therapy for BCa.

Citation Format: Ajit Kumar Navin, Vaibhav Shukla, Balaji Chandrasekaran, Ashish Tyagi, Uttara Saran, Murali K. Ankem, Chendil Damodaran. Molecular landscape of arsenic-induced bladder carcinogenesis [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 745.

Abstract 2999: Activation of NFKB is responsible for defective autophagy in cadmium-induced transformation of prostate cells

Background: Evidence from the epidemiological, laboratory and clinical studies suggest that chronic exposure to cadmium (Cd) leads to the development and progression of prostate cancer (CaP). Previously, we reported defective autophagy due to upregulation of Placenta Specific 8 (Plac8) (a phagosome and lysosome fusion regulator) is responsible for Cd-induced transformation of normal prostate epithelial cells. This study mechanistically dissects the upstream signaling that regulates Plac8 function, which drives defective autophagy during Cd-induced transformation.

Methods: To examine the molecular interaction between NFκB and Plac8, we developed NFκB/Plac8 overexpression and knockdown in normal prostate epithelial cells (RWPE-1) and cadmium transformed prostate epithelial cells lines (CTPE). In addition, we performed phenotypic, and molecular analysis including promoter-based studies, western blot, and in vivo analysis to determine the interaction between Plac8 and p65 in Cd-exposed prostate epithelial cells.

Results: Our results confirmed that overexpression of Plac8 in normal prostate epithelial cells mimics Cd-transformed prostate cells (CTPE) and induces defective autophagy by regulating autophagy-related genes (ATGs) and an enhanced autophagic flux. Conversely, either NFκB or Plac8 knockdown in CTPE cells abrogates autophagy signaling. Further, Cd-exposure failed to induce defective autophagy signaling in transformed cells. Silencing p65 either by genetically or pharmacological inhibitors downregulated Plac8 expression and its survival function in CTPE cells. Hence, we investigated the interaction between NFκB and Plac8 by promoter-based analysis. We found NFκB binding site in the Plac8 promoter, and mutating NFκB binding sites in the Plac8 promoter showed a decline in luciferase activity confirming our hypothesis that NFκB activation is necessary for Plac8 activation and autophagy signaling in CTPE cells. Finally, we confirmed that silencing Plac8 significantly inhibited the tumor growth of CTPE cells compared to vehicle control. Our ongoing studies on xenotransplanted stably knockdown of p65 in CTPE cells may confirm that NFκB activation is responsible for Plac8 function and tumor growth in mice models.

Conclusion: In conclusion, our results suggest that NFκB transcriptionally regulates Plac8 function, which drives pro-survival autophagy signaling in Cd-transformed prostate epithelial cells.

Citation Format: Vaibhav Shukla, Ashish Tyagi, Venkatesh Kolluru, Uttara Saran, Balaji Chandrasekaran, Murali K. Ankem, Chendil Damodaran. Activation of NFKB is responsible for defective autophagy in cadmium-induced transformation of prostate cells [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 2999.

Diagnostic molecular markers predicting aggressive potential in low-grade prostate cancer

Currently, clinicians rely on clinical nomograms to stratify progression risk at the time of diagnosis in patients with prostate cancer (CaP). However, these tools may not accurately distinguish aggressive potential in low-grade CaP. The current study determined the diagnostic potential of 3 molecular markers (ROCK1, RUNX3, and miR-301a) in terms of their ability to identify which low-grade tumors are likely to progress. Real-time PCR and immunohistochemical analysis were used to assess ROCK1, RUNX3, and miR-301a expression profiles in 118 serum and needle biopsy specimens. Expressions of ROCK1 and miR-301a were found to be significantly higher in Gleason 6 and 7 CaP as compared to BPH, while an inverse trend was observed with RUNX3. Further, incorporation of all 3 molecular markers significantly improved clinical nomograms' diagnostic accuracy and correlated with disease progression. Hence, in conclusion, the inclusion of these 3 molecular markers identified aggressive phenotype and predicted disease progression in low-grade CaP tumors at the time of diagnosis.

The role of autophagy in metal-induced urogenital carcinogenesis

Environmental and/or occupational exposure to metals such as Arsenic (As), Cadmium (Cd), and Chromium (Cr) have been shown to induce carcinogenesis in various organs, including the urogenital system. However, the mechanisms responsible for metal-induced carcinogenesis remain elusive. We and others have shown that metals are potent inducers of autophagy, which has been suggested to be an adaptive stress response to allow metal-exposed cells to survive in hostile environments. Albeit few, recent experimental studies have shown that As and Cd promote tumorigenesis via autophagy and that inhibition of autophagic signaling suppressed metal-induced carcinogenesis. In light of the newly emerging role of autophagic involvement in metal-induced carcinogenesis, the present review focuses explicitly on the mechanistic role of autophagy and potential signaling pathways involved in As-, Cd-, and Cr-induced urogenital carcinogenesis.

ASR490, a Small Molecule, Overrides Aberrant Expression of Notch1 in Colorectal Cancer

Notch1 activation triggers significant oncogenic signaling that manifests as enhanced metastatic potential and tumorigenesis in colorectal cancer. Novel small-molecule inhibitors, mainly plant-derived analogs, have low toxicity profiles and higher bioavailability. In this study, we have developed a small molecule, ASR490, by modifying structure of naturally occurring compound Withaferin A. ASR490 showed a growth-inhibitory potential by downregulating Notch1 signaling in HCT116 and SW620 cell lines. Docking studies and thermal shift assays confirmed that ASR490 binds to Notch1, whereas no changes in Notch2 and Notch3 expression were seen in colorectal cancer cells. Notch1 governs epithelial-to-mesenchymal transition signaling and is responsible for metastasis, which was abolished by ASR490 treatment. To further confirm the therapeutic potential of ASR490, we stably overexpressed Notch1 in HCT-116 cells and determined its inhibitory potential in transfected colorectal cancer (Notch1/HCT116) cells. ASR490 effectively prevented cell growth in both the vector (P = 0.005) and Notch1 (P = 0.05) transfectants. The downregulation of Notch1 signaling was evident, which corresponded with downregulation of mesenchymal markers, including N-cadherin and β-catenin and induction of E-cadherin in HCT-116 transfectants. Intraperitoneal administration of a 1% MTD dose of ASR490 (5 mg/kg) effectively suppressed the tumor growth in control (pCMV/HCT116) and Notch1/HCT116 in xenotransplanted mice. In addition, downregulation of Notch1 and survival signaling in ASR-treated tumors confirmed the in vitro results. In conclusion, ASR490 appears to be a potent agent that can inhibit Notch1 signaling in colorectal cancer.

A Survey of Usage of Penile Prosthesis

BACKGROUND

Implantation of an inflatable penile prosthesis (IPP) has high success and satisfaction rates, but there remains a paucity of evidence examining non-usage of IPP and reasons for discontinuation.

AIM

To identify how frequent patients use their prosthesis and their personal reasons for no longer using it.

METHODS

We conducted a survey of all patients who underwent an IPP implantation by a single surgeon over a 6-year period, between 2012 and 2018. After application of inclusion and exclusion criteria, a total of 114 patients formed the final cohort. Patients were initially surveyed via mail with a questionnaire; those who did not respond were surveyed via telephone. The factors determining patient selection for IPP implantation included suitability for general anesthesia, manual dexterity to use the device by the patient or their partner on a demonstration device, and presence of refractory erectile dysfunction, HbA1C lower than 8.5, or need for a revision of a previously placed IPP. Universally, a 3-piece AMS 700 Series implant was placed via the penoscrotal approach. Data were analyzed with Pearson chi square test, and survivability of the device was assessed with Kaplan-Meier survival curve.

OUTCOMES

The main outcomes of this study are the frequency of IPP usage and reasons for discontinuation.

RESULTS

The survey participation rate was 97%. The mean age of patient was 64 years (range 34-83 years), and the mean time between surgery and completion of survey was 2.98 years (range 0.25-7.4 years). Kaplan-Meier curve demonstrated that 68% of the patients were using the IPP at 5 years after implantation. Using the age 70 years as a cutoff, 18 (22%) patients younger than 70 years and 14 (42%) patients older than 70 years discontinued using the IPP (P = .029). The commonest reasons for discontinuation were poor health to engage in sexual activity (2.6%), loss of companion (19%), loss of interest in sex (2.6%), and device malfunction with no further interest in revision of prosthesis (14%).

CLINICAL IMPLICATIONS

The clinical implication of this study was improved patient selection for device implantation.

STRENGTHS AND LIMITATIONS

To our knowledge, no other study has investigated reasons for patients no longer using their prosthesis. Our study has several limitations including that it is a cross-sectional analysis, our survey is not validated, this is a single-surgeon experience, we have a small sample size, and we did not differentiate between virgin implant and reimplantation.

CONCLUSION

Our study shows a high rate (28%) of non-usage of IPP, more so in men older than the age of 70 years in the first 5 years of implantation. Knoll P, Rai S, Talluri S, et al. A Survey of Usage of Penile Prosthesis. J Sex Med 2020;17:2287-2290.

ASR488, a novel small molecule, activates an mRNA binding protein, CPEB1, and inhibits the growth of bladder cancer

Due to a lack of mechanistic insights, muscle-invasive bladder cancer (MIBC) remains incurable and is one of the most lethal types of cancer in the United States. The present study investigated changes in the molecular signatures of MIBC cells (TCCSUP and HT1376) after treatment with a novel small molecule, ASR488, to gain knowledge of the mechanisms that inhibited MIBC cell growth. ASR488 treatment initiated apoptotic signaling in MIBC cells. Pathway enrichment analysis was used to analyze the changes in function of differentially expressed genes. Gene Ontology analysis, as well as Kyoto Encyclopedia of Genes and Genomes analysis, was also performed. These analyses along with reactome pathway enrichment analyses indicated that the genes upregulated in the ASR488-treated cells are involved in focal adhesion, neurotrophin signaling, p53 signaling, endoplasmic reticulum functioning in terms of protein processing, and pathways related to bladder cancer. The genes downregulated in ASR488-treated MIBC cells were mainly involved in DNA replication, mismatch repair, RNA degradation, nucleotide excision repair and TGFβ signaling (P<0.05). Furthermore, reverse transcription-quantitative PCR analysis revealed an increase in transcripts of the most upregulated genes in ASR 488-treated MIBC cells: CPEB1 (36-fold), IL11 (30-fold), SFN (20.12-fold) and CYP4F11 (15.8-fold). In conclusion, the analysis of biological functions of the most differentially expressed genes revealed possible mechanisms that may be associated with the aggressiveness of MIBC.

Chronic exposure to cadmium induces a malignant transformation of benign prostate epithelial cells

Epidemiological evidence suggests that cadmium (Cd) is one of the causative factors of prostate cancer, but the effect of Cd on benign prostatic hyperplasia (BPH) remains unclear. This study aimed to determine whether Cd exposure could malignantly transform BPH1 cells and, if so, to dissect the mechanism of action. We deciphered the molecular signaling responsible for BPH1 transformation via RNA-sequencing and determined that Cd induced the expression of zinc finger of the cerebellum 2 (ZIC2) in BPH1 cells. We noted Cd exposure increased ZIC2 expression in the Cd-transformed BPH1 cells that in turn promoted anchorage-independent spheroids and increased expression of stem cell drivers, indicating their role in stem cell renewal. Subsequent silencing of ZIC2 expression in transformed cells inhibited spheroid formation, stem cell marker expression, and tumor growth in nude mice. At the molecular level, ZIC2 interacts with the glioma-associated oncogene family (GLI) zinc finger 1 (GLI1), which activates prosurvival factors (nuclear factor NFκB, B-cell lymphoma-2 (Bcl2), as well as an X-linked inhibitor of apoptosis protein (XIAP)) signaling in Cd-exposed BPH1 cells. Conversely, overexpression of ZIC2 in BPH1 cells caused spheroid formation confirming the oncogenic function of ZIC2. ZIC2 activation and GLI1 signaling induction by Cd exposure in primary BPH cells confirmed the clinical significance of this oncogenic function. Finally, human BPH specimens had increased ZIC2 versus adjacent healthy tissues. Thus, we report direct evidence that Cd exposure induces malignant transformation of BPH via activation of ZIC2 and GLI1 signaling.

Abstract 2598: Developing small molecule inhibitors that target androgen receptor signaling in castration-resistant prostate cancer

The transcription factor, androgen receptor (AR) is a key driver and plays an important role in prostate cancer. Androgen ablation therapy and brachytherapy remains the standard treatment of advanced prostate cancer, but unfortunately, it is not curative, and eventually the disease returns as lethal castration-resistant prostate cancer (CRPC). Previously we have reported that Urolithin A (Uro A), a natural compound, inhibits AR signaling and suppresses the growth of CRPC. Now, we have developed a series of pro-drug conjugates of Uro A and our initial structure-activity relationship (SAR) studies led to the identification of three small molecules as lead compounds. Hence, we investigated the effects of all three compounds and dissected their molecular mechanism in cell culture and mouse models of CRPC. All the three compounds more effectively inhibited the growth CRPC cell lines than the parent compound Uro A. Based on their IC50 concentration; we identified a novel compound (ASR-600) that demonstrated better efficacy by inhibiting AR signaling in CRPC cell lines than the parental compound Uro A. The model system and molecular dynamics (MD) stimulation studies suggest that ASR600 bind to the ligand-binding domains of AR and blocks the conformation changes, that allows AR to phosphorylate and degrade in the cytosol. Further, our thermal shift assay confirmed ASR 600 binds to AR in presence and absence of Dihydrotestostreone. Our ongoing in vivo studies, may suggest whether oral administration of ASR-600 effectively inhibits the tumor growth raised from CRPC cell lines (C4-2B, 22RV1 and enzalutamide resistance C4-2B) in xenografted mice. These observations provide a rationale for devising novel therapeutic agent based on ASR 600 for the treatment of CRPC

Citation Format: Balaji Chandrasekaran, Ashish Tyagi, Venkatesh Kolluru, Aakash M. Vadhanam, Becca von Baby, Suresh Gorle, Suman Sirimulla, Srinivasa R. Ramisetti, Arun K. Sharma, Murali K Ankem, Chendil damodaran. Developing small molecule inhibitors that target androgen receptor signaling in castration-resistant prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2598.

The chemopreventive effect of withaferin A on spontaneous and inflammation-associated colon carcinogenesis models

Chemopreventive effects and associated mechanisms of withaferin A (WA) against intestinal and colon carcinogenesis remain unknown. We investigated the chemopreventive effect of WA on transgenic adenomatous polyposis coli (APCMin/+) mouse and chemically induced azoxymethane/dextran sodium sulfate (AOM/DSS) models of intestinal and colon carcinogenesis. Oral WA administration (4 and 3 mg/kg) inhibited tumor initiation and progression of intestinal polyps formation in APCMin/+ mice and colon carcinogenesis in the AOM/DSS mouse model. WA-administered mice showed a significant reduction in both number [duodenum, 33% (P > 0.05); jejunum, 32% (P < 0.025); ileum, 43% ( P < 0.001); and colon 59% (P < 0.01] and size of polyps in APCMin/+ mice compared with the respective controls. Similarly, tumor multiplicity was significantly reduced (P < 0.05) in the colon of WA-administered AOM/DSS mice. Pathological analysis showed reduced adenomas and tissue inflammation in WA-administered mouse models. Molecular studies suggested that WA inhibited the expression of inflammatory (interluekin-6, tumor necrosis factor-alpha and cyclooxygenase-2), pro-survival (pAKT, Notch1 and NF-κB) markers in APCMin/+ and AOM/DSS models. The results suggest that WA is a potent agent for preventing colon carcinogenesis and further investigation is required to show clinical utility of the agent.

Suppression of Notch1 and AKT mediated epithelial to mesenchymal transition by Verrucarin J in metastatic colon cancer

Epithelial to mesenchymal transition (EMT) in colorectal cancer (CRC) has been attributed to activation of AKT and Notch1 signaling pathways. As EMT corresponds to increased aggressiveness of CRC, approaches that prevent metastasis by targeting AKT/Notch1 pathways are at the forefront of current research paradigms. This study examined the anti-metastatic potential of Verrucarin J (VJ), a small molecule, in CRC cells overexpressing AKT and Notch1. VJ significantly inhibited AKT/HCT 116 cell growth by acting on the AKT/NFκB/Bcl-2 signaling axis and initiated apoptotic signaling as was evident from increased expression of pro-apoptotic markers such as cleaved PARP, cleaved caspase 3, and cleaved caspase 9. Also, VJ inhibited the cell growth in AKT/Notch1-overexpressing CRC cells and abrogated EMT. The down-regulation of AKT and Notch1 signaling was apparent in immunoblot analysis and corresponded with down-regulation of mesenchymal markers including Snail, and β-catenin. Intraperitoneal administration of VJ in control (pCMV/HCT 116) and AKT/HCT 116 mice significantly suppressed AKT-induced tumor growth in a xenograft model. In addition, down-regulation of prosurvival markers as well as AKT and Notch1 was observed in the immunohistochemical analysis of the xenografted tumors. In conclusion, our study substantiates the role of AKT and Notch1 in cell proliferation, angiogenesis, and EMT of CRC cells and demonstrates that VJ may be a viable therapeutic option to counter AKT-induced cell proliferation and tumor outgrowth in CRC.

Abstract 4810: Targeting androgen receptor in combination with cisplatin: Effective treatment strategy for muscle invasive bladder cancer

Background: Bladder cancer is one of the major causes of cancer death in US and worldwide. Cisplatin is a key component of chemotherapeutic regimens employed in the treatment of advanced bladder cancer. The role of androgen and androgen receptor (AR) signaling in bladder cancer remains uncharacterized.

Aim: The aim of the study is to delineate the role of AR in bladder cancer and to determine whether combination of AR inhibitor, enzalutamide (Enz) and cisplatin-based therapies effectively inhibit the growth of muscle invasive bladder cancer (MIBC).

Methods: AR expression was determined in 75 human bladder cancer specimens and in a panel of bladder cancer cell lines. Cells grown in charcoal stripped media supplemented with dihydrotestosterone (DHT) were treated with cisplatin, enzalutamide (AR inhibitor), or a combination of both. Cellular/phenotypic analysis including MTT assay, apoptotic assay, migration as well as invasion assays and molecular analysis including western blotting, real time PCR analysis were performed. Isobologram analysis for the combination was performed and analyzed with CompuSyn. Experiments were repeated in triplicates and analyzed with unpaired Student's t-test and one way ANOVA *p≤0.05, **p≤0.01, ***p≤0.001.

Results: AR expression was seen in around 40% of bladder cancer patients. Inhibition of AR signaling by enzalutamide effectively inhibited the growth of AR+ MIBC cells. Interestingly, enzalutamide in combination with cisplatin (Enz + Cis) synergistically inhibited the proliferation of MIBC cells, TCCSUP (CI: 0.42, 1.25 + 5 μM) and J82 (CI: 0.79, 2.5 + 5 μM) at low concentrations of enzalutamide and cisplatin resp.. The molecular studies revealed the induction of DNA damage markers (pATM, pATR, pChk1, pHis) and enhanced expression of the pro-apoptotic genes (Bax, caspases-3 and PARP) in Enz+Cis treated AR+ MIBC cells. In addition, we demonstrated abrogation of invasive and migratory potential with Enz+Cis treatment, by downregulation of the mesenchymal markers (N-cadherin, slug, β-catenin, and vimentin) in both cell lines. Our studies suggest combination of Enz + Cis may be effective in patients with AR+ MIBC.

Conclusion: Combination of cisplatin and AR inhibition effectively inhibit bladder tumor growth and migration, and hold promise as synergetic therapies for AR+ bladder cancer patients.

Citation Format: Ashish Tyagi, Balaji Chandersekaran, Samarpit Rai, Houda Alatassi, Ahmed Q. Haddad, Murali K. Ankem, Chendil Damodaran. Targeting androgen receptor in combination with cisplatin: Effective treatment strategy for muscle invasive bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4810.

Abstract 1328: Cadmium-induced endoplasmic reticulum stress causes defective autophagy in human prostate carcinogenesis

Introduction: Exposure to cadmium (Cd) is associated with a spectrum of human pathogenesis including the prostate cancer (CaP). A clear dose-response relation between Cd-exposure and CaP have been reported in men exposed to Cd. However, the molecular mechanism underlying the malignant cell transformation following Cd exposure is yet to be determined. One of the possible mechanisms is that Cd causes endoplasmic reticulum (ER) stress, which further induces defective autophagy that plays a cytoprotective role in response to the misfolded and unfolded proteins that are formed during cellular transformation. Hence, the goal of this study is to investigate the underlying mechanism of how Cd causes malignant cell transformation (from normal to cancer cells) and on the development of tumorigenesis by the Cd-transformed cells.

Methods: Normal prostate epithelial cells (RWPE-1) and Cd (10µM)-transforming prostate epithelial cells and cadmium-transformed prostate epithelial cells (CTPE) were utilized. Overexpression and/or silence ER-sensors, EGFR, and p62 were performed in above mention cell lines and subjected to cell viability, apoptosis, autophagy functional studies and Western blot analyses. For statistical analysis, data were analyzed using Student's ‘t' test with a p-value less than 0.05 considered significant.

Results: Our preliminary results suggest that during cellular transformation, Cd exposure induced ER-stress, which triggered the phosphorylation of stress transducers including protein kinase R-like ER Kinase (PERK) and e1F2-α (eukaryotic translation initiation factor 2A-alpha). Phosphorylation resulted in the activation of ATF4 (Activating Transcription Factor 4) and autophagy induction thus enhancing protection of Cd-damaged cells. Further, inhibition of stress inducers (ATF4) or p62 by siRNA blocked the Cd-induced defective autophagy resulted in growth inhibition in transforming cells. Interestingly, in Cd-transformed cells, blocking EGFR activation by siRNA or pharmacological inhibitors significantly inhibited the growth, but not in the transforming cells suggesting that EGFR activation plays a critical role only after cellular transformation. Further, xenograft tumor tissues generated by Cd-transformed cells expressed high levels of ATF-4, EGFR, p62 and LC3B in correlation with in vitro findings. Moreover, increased expression of the proteins (ATF-4, EGFR, p62, and LC3B) in human CaP specimens correlates with Gleason sum in comparison with benign prostatic hyperplasia and “normal” adjacent tissues.

Conclusions: The results suggest that ER stress responsible for the defective autophagy in Cd-induced transformation. This study highlights the better understanding of the complex interrelationship among prostate cancer phenotypes and the molecular, cellular, biochemical, and pathological changes associated with Cd and prostate cancer.

Citation Format: Venkatesh Kolluru, Ashish Tyagi, Balaji Chandrasekaran, Murali K. Ankem, Chendil Damodaran. Cadmium-induced endoplasmic reticulum stress causes defective autophagy in human prostate carcinogenesis [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 1328.

Oral administration of withaferin A inhibits carcinogenesis of prostate in TRAMP model

We previously reported that withaferin A (WA), a natural compound, deters prostate cancer by inhibiting AKT while inducing apoptosis. In the current study, we examined its chemopreventive efficacy against carcinogenesis in the prostate using the transgenic adenocarcinoma of mouse prostate (TRAMP) model. Two distinct sets of experiments were conducted. To determine whether WA delays tumor progression, it was given before cancer onset, at week 6, and until week 44. To determine its effect after the onset of prostate cancer, it was given from weeks 12 to 35. In both strategies, oral administration of WA effectively suppressed tumor burden when compared to vehicle-treated animals. No toxicity was seen in treated animals at gross pathological examination. Western blot analysis and immunohistochemistry of tumor sections revealed that in TRAMP controls, AKT and pAKT were highly expressed while nuclear FOXO3a and Par-4 were downregulated. On the contrary, treated mice showed inhibition of AKT signaling and activation of FOX03a-Par-4-induced cell death. They also displayed inhibition of mesenchymal markers such as β-catenin, vimentin, and snail as well as upregulation of E-cadherin. Because expressions of the angiogenic markers factor VIII and retic were downregulated, an anti-angiogenic role of WA is suggested. Overall, our results suggest that WA could be a promising anti-cancer agent that effectively inhibits carcinogenesis of the prostate.

Withaferin-A suppress AKT induced tumor growth in colorectal cancer cells

The oncogenic activation of AKT gene has emerged as a key determinant of the aggressiveness of colorectal cancer (CRC); hence, research has focused on targeting AKT signaling for the treatment of advanced stages of CRC. In this study, we explored the anti-tumorigenic effects of withaferin A (WA) on CRC cells overexpressing AKT in preclinical (in vitro and in vivo) models. Our results indicated that WA, a natural compound, resulted in significant inhibition of AKT activity and led to the inhibition of cell proliferation, migration and invasion by downregulating the epithelial to mesenchymal transition (EMT) markers in CRC cells overexpressing AKT. The oral administration of WA significantly suppressed AKT-induced aggressive tumor growth in a xenograft model. Molecular analysis revealed that the decreased expression of AKT and its downstream pro-survival signaling molecules may be responsible for tumor inhibition. Further, significant inhibition of some important EMT markers, i.e., Snail, Slug, β-catenin and vimentin, was observed in WA-treated human CRC cells overexpressing AKT. Significant inhibition of micro-vessel formation and the length of vessels were evident in WA-treated tumors, which correlated with a low expression of the angiogenic marker RETIC. In conclusion, the present study emphasizes the crucial role of AKT activation in inducing cell proliferation, angiogenesis and EMT in CRC cells and suggests that WA may overcome AKT-induced cell proliferation and tumor growth in CRC.

Induction of Plac8 promotes pro-survival function of autophagy in cadmium-induced prostate carcinogenesis

Chronic exposure to cadmium is known to be a risk factor for human prostate cancer. Despite over-whelming evidence of cadmium causing carcinogenicity in humans, the specific underlying molecular mechanisms that govern metal-induced cellular transformation remain unclear. Acute exposure (up to 72 h) to cadmium induces apoptosis in normal prostate epithelial cells (RWPE-1), while chronic exposure (>1 year) transforms these cells to a malignant phenotype (cadmium-transformed prostate epithelial cells; CTPE). Increased expression of autophagy-regulated genes; Plac8, LC3B and Lamp-1; in CTPE cells was associated with cadmium-induced transformation. Increased expression of Plac8, a regulator of autophagosome/autolysosome fusion, facilitates the pro-survival function of autophagy and upregulation of pAKT^(ser473) and NF-κβ, to allow CTPE to proliferate. Likewise, inhibition of Plac8 suppresses CTPE cell growth. Additionally, overexpression of Plac8 in RWPE-1 cells induces resistance to cadmium toxicity. Pharmacological inhibitors and an inducer of autophagy failed to affect Plac8 expression and CTPE cell viability, suggesting a unique role for Plac8 in cadmium-induced prostate epithelial cell transformation. These results support a role for Plac8 as an essential component in the cadmium-induced transformation of normal prostate epithelial cells to a cancerous state.

Inhibition of autophagy prevents cadmium-induced prostate carcinogenesis

BACKGROUND

Cadmium, an established carcinogen, is a risk factor for prostate cancer. Induction of autophagy is a prerequisite for cadmium-induced transformation and metastasis. The ability of Psoralidin (Pso), a non-toxic, orally bioavailable compound to inhibit cadmium-induced autophagy to prevent prostate cancer was investigated.

METHODS

Psoralidin was studied using cadmium-transformed prostate epithelial cells (CTPE), which exhibit high proliferative, invasive and colony forming abilities. Gene and protein expression were evaluated by qPCR, western blot, immunohistochemistry and immunofluorescence. Xenograft models were used to study the chemopreventive effects in vivo.

RESULTS

Cadmium-transformed prostate epithelial cells were treated with Pso resulting in growth inhibition, without causing toxicity to normal prostate epithelial cells (RWPE-1). Psoralidin-treatment of CTPE cells inhibited the expression of Placenta Specific 8, a lysosomal protein essential for autophagosome and autolysosome fusion, which resulted in growth inhibition. Additionally, Pso treatment caused decreased expression of pro-survival signalling proteins, NFκB and Bcl2, and increased expression of apoptotic genes. In vivo, Pso effectively suppressed CTPE xenografts growth, without any observable toxicity. Tumours from Pso-treated animals showed decreased autophagic morphology, mesenchymal markers expression and increased epithelial protein expression.

CONCLUSIONS

These results confirm that inhibition of autophagy by Pso plays an important role in the chemoprevention of cadmium-induced prostate carcinogenesis.

Targeting aberrant expression of Notch-1 in ALDH+ cancer stem cells in breast cancer

We have previously reported that high aldehyde dehydrogenase (ALDH) enzyme activity in breast cancer cells results in breast cancer stem cell (BCSC) properties by upregualting Notch-1 and epithelial mesenchymal markers. This results in chemoresistance in breast cancer. Here, we examined the functional and clinical significance of ALDH expression by measuring the ALDH levels in breast cancer tissues by immunohistochemistry. There was a significantly higher ALDH expression in higher grade breast cancer tumor tissues (Grade- II and III) versus normal breast tissues. Injection of BCSC (ALDH⁺ and CD44⁺ /CD22^- ) cells resulted in aggressive tumor growth in athymic mice versus ALDH^- cells. The ALDH⁺ and CD44⁺ /CD22^- tumors grow rapidly and are larger than ALDH^- tumors which were slow growing and smaller. Molecularly, ALDH⁺ tumors expressed higher expression of Notch-1 and EMT markers than ALDH^- tumors. Oral administration of the naturally occurring Psoralidin (Pso, 25 mg/kg of body weight) significantly inhibited the growth in ALDH⁺ and ALDH^- tumors as well. Psoralidin inhibited Notch-1 mediated EMT activation in ALDH⁺ and ALDH^- tumors-this confirms our in vitro findings. Our results suggest that Notch-1 could be an attractive target and inhibition of Notch-1 by Psoralidin may prevent pathogenesis of breast cancer as well as metastasis. © 2016 Wiley Periodicals, Inc.

miR-301a expression: A prognostic marker for prostate cancer

PURPOSE

The diagnosis and treatment of prostate cancer (CaP) continues to be challenging, as prostate-specific antigen (PSA) appears to be overly sensitive and biopsy is the only reliable method for confirmation. Hence, the goal of the study is to identify a biomarker that could distinguish malignant cancer from benign prostatic hyperplasia (BPH) during the early diagnosis of the disease.

MATERIALS AND METHODS

A total of 75 formalin fixed paraffin embedded (FFPE) with matching controls, 4 paired metastatic tumors, 6 fresh tumor tissues and BPH (13 cases) with their clinical diagnosis were selected for this study. Prostate cancer cell lines and normal prostate epithelial cell lines were obtained from ATCC and subjected to phenotypic analysis.

RESULTS

We observed significant differential expression of miR-301a in CaP samples in comparison to BPH and adjacent benign samples. The overexpression of miR-301a activates the invasion/migration of CaP cells. In contrast, silencing miR-301a expression inhibited the colony-forming ability, adhesion, invasion and migration of CaP cells. Similarly, the overexpression of miR-301a increased cell motility in normal RWPE-1 prostate epithelial cells. Our results suggest that miR-301a is differentially expressed between BPH and CaP specimens and that the expression of miR-301a correlates with biochemical recurrence and/or metastasis in CaP patients.

CONCLUSIONS

The expression of miR-301a could be a potential marker for metastasis in CaP patients. Detecting miR-301a expression during diagnosis will avoid wait and watch timelines, thus preventing morbidity.

Abstract 5253: Oral administration of Withaferin-A effectively suppresses prostate carcinogenesis in PTEN-Knockout mice

Androgen ablation therapy alone or in combination with radiation therapy is the mainstay for prostate cancer (CaP), which is initially effective in de-bulking the tumor volume, however, eventually these patients will progress to a castration-resistant prostate cancer (CRPC), which requires more aggressive chemotherapies. Treating CRPC with second generation androgen -ablation based therapies like enzalutamide and abiraterone exhibit only a short window of therapeutic benefit resulting in chemoresistance. Hence, there is an immediate need for identification of novel targets to eradicate CRPC effectively. We and others have reported targeting AKT activation could efficiently suppress the growth of CRPC cells; in fact a number of clinical trials have shown some promise that AKT could be an attractive target for CRPC. In fact, clinical studies from our lab have suggested that AKT activation predominantly occurs in Gleason stage specific manner suggesting identification of novel drugs to inhibit AKT activation is imperative. Our earlier finding suggests that Withaferin-A (WA), an herbal molecule effectively inhibits the growth of CRPC cells by downregulating AKT activation and its downstream pro-survival events. Present study investigated whether oral administration of WA may inhibit tumor development in Pten conditional knockout mice [(Pten-loxp/loxp:PB-Cre4+) (Pten-KO)] which will be a unique and appropriate preclinical model to study the AKT driven prostate tumor. Oral administration of WA for 45 weeks effectively prevented the tumor growth without any significant signs of toxicity to organs in Pten-KO mice. Vehicle and WA (5mg/kg body weight) were orally given up to 45 weeks. Gross pathological studies suggested a significant inhibition of growth and micro metastasis in WA-treated mice as compared to the vehicle treated mice. On microscopic examination of the prostatic tissue, we found that the WA-treated tumors showed more necrosis than the control group and some of the tumors were more differentiated than the controls in the same group. All the organs were completely submitted for histological evaluation. None of the WA-treated mice organs showed any metastatic lesion on the other hand, we found discrete metastasis to lungs in the control tumors. Our ongoing immunohistochemistry analysis may corroborate our in vitro findings that down regulation of AKT and epithelial-to-mesenchymal transition (EMT) markers such as β-catenin, snail, and vimentin in WA treated tumors as compared to the control mice. Overall, these results provide important scientific evidence in support of AKT signaling as a target to inhibit CRPC as well as metastatic CRPC.

Citation Format: Chendil Damodaran, Suman Suman, Trinath P. Das, Houda Alatassi, Murali K. Ankem. Oral administration of Withaferin-A effectively suppresses prostate carcinogenesis in PTEN-Knockout mice. [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 5253.

Activation of AKT negatively regulates the pro-apoptotic function of death-associated protein kinase 3 (DAPK3) in prostate cancer

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This is the first study that demonstrates the inverse correlation of AKT activation and down-regulation of tumor suppressor protein, DAPK-3, in CaP cell lines as well as human prostate tumor tissues that correlate with disease progression.

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Either silencing AKT or overexpressing DAPK-3 induces apoptosis in Castration Resistant Prostate Cancer cells.

The activation of AKT governs many signaling pathways and promotes cell growth and inhibits apoptosis in human malignancies including prostate cancer (CaP). Here, we investigated the molecular association between AKT activation and the function of death-associated protein kinase 3 (DAPK3) in CaP. An inverse correlation of pAKT and DAPK3 expression was seen in a panel of CaP cell lines. Inhibition of AKT by wortmannin/LY294002 or overexpression of DAPK3 reverts the proliferative function of AKT in CaP cells. On the other hand, ectopic expression of AKT inhibited DAPK3 function and induced proliferation of CaP cells. In addition, AKT over-expressed tumors exhibit aggressive growth when compared to control vector in xenograft models. The immunohistochemistry results revealed a down-regulation of DAPK3 expression in AKT over-expressed tumors as compared to control tumors. Finally, we examined the expression pattern of AKT and DAPK3 in human CaP specimens – the expected gradual increase and nuclear localization of pAKT was seen in higher Gleason score samples versus benign hyperplasia (BPH). On the contrary, reduced expression of DAPK3 was seen in higher Gleason stages versus BPH. This suggests that inhibition of DAPK3 may be a contributing factor to the carcinogenesis of the prostate. Understanding the mechanism by which AKT negatively regulates DAPK3 function may suggest whether DAPK3 can be a therapeutic target for CaP.

Oxidative Stress: A Promising Target for Chemoprevention

Cancer is a leading cause of death worldwide, and treating advanced stages of cancer remains clinically challenging. Epidemiological studies have shown that oxidants and free radicals induced DNA damage is one of the predominant causative factors for cancer pathogenesis. Hence, oxidants are attractive targets for chemoprevention as well as therapy. Dietary agents are known to exert an anti-oxidant property which is one of the most efficient preventive strategy in cancer progression. In this article, we highlight dietary agents can potentially target oxidative stress, in turn delaying, preventing, or treating cancer development. Some of these agents are currently in use in basic research, while some have been launched successfully into clinical trials.

Natural Products That Target Cancer Stem Cells

The cancer stem cell model suggests that tumor initiation is governed by a small subset of distinct cells with stem-like character termed cancer stem cells (CSCs). CSCs possess properties of self-renewal and intrinsic survival mechanisms that contribute to resistance of tumors to most chemotherapeutic drugs. The failure to eradicate CSCs during the course of therapy is postulated to be the driving force for tumor recurrence and metastasis. Recent studies have focused on understanding the unique phenotypic properties of CSCs from various tumor types, as well as the signaling pathways that underlie self-renewal and drug resistance. Natural products (NPs) such as those derived from botanicals and food sources may modulate vital signaling pathways involved in the maintenance of CSC phenotype. The Wingless/Integrated (WNT), Hedgehog, Notch and PI3K/AKT/mTOR pathways have all been associated with quiescence and self-renewal of CSCs, as well as execution of CSC function including differentiation, multidrug resistance and metastasis. Recent studies evaluating NPs against CSC support the epidemiological evidence linking plant-based diets with reduced malignancy rates. This review covers the key aspects of NPs as modulators of CSC fate.

Abstract 4114: Chemopreventive and chemotherapeutic effect of Withaferin-A on in vivo models of prostate cancer

Several groups have emphasized on the functional role of phytochemicals in chemoprevention and chemotherapy of prostate cancer (CaP). In this study we have focused on Withaferin A (WA) a bioactive compound derived from Withania somnifera, which has been extensively used in Asian and African traditional medicine system. In our in vitro studies, WA inhibits the growth of CRPC cells by targeting AKT mediated pro-survival signaling and simultaneously activating FOXO3a dependent apoptosis in CaP cell lines. The objective of the present study was to evaluate the in vivo efficacy of WA on both xenograft and transgenic adenocarcinoma of mouse prostrate (TRAMP) models. DU-145 and C4-2B CaP cells stably overexpressing AKT were xenografted in nude mice and WA (5mg/kg body weight) was orally administered along with control groups fed with oil alone for 4-5 weeks. AKT-overexpressing tumors showed 2-3-fold faster growth than pCMV-expressing tumors and oral administration of WA significantly reduced AKT-induced tumor growth. Immunohistochemistry of tumor sections revealed high expression of AKT, pAKT and down regulation of nuclear FOXO3a in tumor sections derived from AKT-overexpressing tumors. On the contrary, WA treated controls as well as AKT over expressed tumor sections clearly revealed that WA reverted FOXO3a mediated apoptotic signaling by down regulating AKT activation. In addition, activation of AKT has emerged as a central feature of epithelial-mesenchymal transition (EMT). Our results also revealed elevated expression of important EMT related transcription factors and genes such as snail, slug, β-catenin, vimentin, and MMPs and decrease in the expression of E-cadherin expression in AKT overexpressing tumors. Simultaneously, WA treatment of pCMV and AKT-overexpressing tumors showed decrease in the expression of these EMT markers and increase in the expression of E-cadherin.

Similarly, TRAMP mice were randomized into controls and WA (oral gavage-3mg/kg body weight) for 31 weeks. Control and WA-treated mice were sacrificed periodically at 11, 20, 27 and 31 weeks. Histopathological examination revealed both the groups (control and WA-treated) showed prostatic hyperplasia with no signs of metastasis up to 20 weeks. However, 58.3% mice in the control group showed metastasis to lungs, liver or kidneys, whereas in the treatment group 16.6% mice showed metastasis in 31 weeks. Molecular analysis showed higher expression of phosphorylated AKT, FOXO3a, along with EMT markers like β-catenin, snail, vimentin and down regulation of E-cadherin expression in control-TRAMP tumors. On the other hand, WA-treated tumor tissues revealed low expression of pAKT and pFOXO3a in WA treated mice. Also, low expression of β-catenin; snail, vimentin and upregulation of E-cadherin in WA treated mice was observed. These results potentiate the chemopreventive and chemotherapeutic effects of WA in CaP and steers the clinical translation of this biomolecule.

Citation Format: Suman Suman, Trinath P. Das, Murali K. Ankem, Chendil Damodaran. Chemopreventive and chemotherapeutic effect of Withaferin-A on in vivo models of prostate cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4114. doi:10.1158/1538-7445.AM2015-4114

Targeting Notch Signaling in Colorectal Cancer

The activation of Notch signaling is implicated in tumorigenesis in the colon due to the induction of pro-survival signaling in colonic epithelial cells. Chemoresistance is a major obstacle for treatment and for the complete eradication of colorectal cancer (CRC), hence, the inhibition of Notch is an attractive target for CRC and several groups are working to identify small molecules or monoclonal antibodies that inhibit Notch or its downstream events; however, toxicity profiles in normal cells and organs often impede the clinical translation of these molecules. Dietary agents have gained momentum for targeting several pro-survival signaling cascades, and recent studies demonstrated that agents that inhibit Notch signaling result in growth inhibition in preclinical models of CRC. In this review, we focus on the importance of Notch as a preventive and therapeutic target for colon cancer and on the effect of WA on this signaling pathway in the context of colon cancer.

Inferior vena cava filter penetration into right proximal ureter

Inferior vena cava (IVC) filter penetration into the renal collecting system is an infrequent event. We report a case of IVC filter penetration into the right proximal ureter resulting in gross hematuria, hydronephrosis and stone formation.

Laparoendoscopic single-site varicocele repair in adolescents-initial experience at a single institution

BACKGROUND AND PURPOSE

Laparoendoscopic single-site (LESS) varicocele repair is a modification of standard laparoscopic varicocele repair that uses a single port. We describe our initial experience with LESS varicocele repair.

PATIENTS AND METHODS

During a 1-year period, all patients who presented for varicocele repair underwent LESS repair. We evaluated our initial experience by determining operative time, operative and postoperative complications, and overall cost of the procedure.

RESULTS

A total of 11 adolescents underwent LESS varicocele repair. There were no intraoperative complications, and there were no conversions to open surgery or traditional laparoscopy. Estimated blood loss was minimal, and mean operative time was 66.9 minutes (range 48-91 min). The varicocele was corrected in all cases. During the 4 to 14 month follow-up, there was no recurrence, testis atrophy, or hernia in any patient. One subclinical hydrocele developed postoperatively that has not been repaired.

CONCLUSION

Our experience with LESS varicocele repair in adolescents suggests it to be a safe and effective method for varicocele repair in adolescents.

Laparoendoscopic single site orchiopexy

We report a laparoendoscopic single site orchiopexy in a 2-year-old boy with a right nonpalpable testis. Diagnostic laparoscopy using a 5-mm port revealed a right intraabdominal testis. The 5-mm port site was extended to accommodate the smallest commercially available triport, and orchiopexy was performed. The operative time was 55 minutes, and the estimated blood loss was minimal. There were no complications, and surgical and cosmetic results were excellent. Laparoendoscopic single site surgery is a feasible technique for orchiopexy of the nonpalpable testis.

Pediatric single-port-access nephrectomy for a multicystic, dysplastic kidney

Major urologic surgery via a single port has emerged as the latest progression in laparoscopy and robotics. While current literature highlights the single-port approach to the surgical treatment of cholecystitis, appendicitis and varicoceles, this technique has never been employed to perform a nephrectomy on a child. We herein report a case of a pediatric patient who underwent nephrectomy via single-port-access.

Examination of laparoscopic retrieval bag washings for malignant cells after hand-assisted laparoscopic radical nephrectomy and intact specimen removal

OBJECTIVES

Port site metastases after hand-assisted laparoscopic radical nephrectomy have been described in the literature. There is no uniform agreement among urologists regarding the use of a retrieval bag before intact specimen removal. The aim of this study was to determine whether LapSac renal extraction bag washings contain malignant cells.

METHODS

We prospectively obtained washings from the LapSac retrieval bag after hand-assisted laparoscopic radical nephrectomy and intact specimen removal for renal cell carcinoma. In 30 consecutive cases, after removal of the kidney specimen from the LapSac, the LapSac was irrigated with 50 mL sterile Hank's balanced salt solution. These washings were sent for cytologic examination. Cytologic evaluation was performed with a Thin Prep and the Papanicolaou method.

RESULTS

We performed 30 hand-assisted laparoscopic radical nephrectomies for suspected renal cell carcinoma with the above protocol. One specimen was benign and one showed transitional cell carcinoma; these were excluded from the study. Six specimens were stage T1a, 17 were T1b, 1 was T2, 2 were T3a, and 2 were T3b. Histopathology revealed 27 specimens with clear cell renal cell carcinomas with Fuhrman grades from 1 to 4; 1 specimen showed chromophobe renal cell carcinoma. Margins were negative in all cases, and there were no gross or microscopic tumor violations. The cytologic results from 27 cases were negative and in 1 case with T3b renal cell carcinoma the LapSac washings were positive for malignant cells.

CONCLUSIONS

The preliminary findings from our study show that low-stage, low-grade tumors removed laparoscopically with minimal manipulation do not exfoliate cells into their LapSac retrieval bags.

Magnetic resonance imaging findings after laparoscopic renal cryoablation

OBJECTIVES

To assess the magnetic resonance imaging (MRI) appearance of renal masses after laparoscopic cryoablation.

METHODS

Between October 2000 and June 2004, 33 patients underwent laparoscopic cryoablation of 34 renal masses, 24 of whom (25 renal masses, size range 1.5 to 3.7 cm, mean 2.4) were followed up with MRI postoperatively. Postoperative MRI was done at 1, 3, and 6 months after ablation and every 6 months thereafter using a 1.5-T MRI scanner. T1-weighted dual-phase, coronal T1-weighted fat-saturated, and T2-weighted coronal and axial MRI was done before contrast administration. Postenhancement images were obtained in the coronal and axial planes during the arterial, venous, and delayed phases.

RESULTS

Patient follow-up data were available for at least 6 months and up to 48 months for 18 patients. On the first follow-up MRI study, six lesions had increased in size, five had decreased in size, and seven showed no change. Of the 18 patients, 7 had peripheral rim enhancement within 3 months of follow-up. Four resolved. One patient developed rim enhancement at 7 months postoperatively. Subsequent images revealed lesion enlargement with heterogeneous enhancement. Biopsy was positive for renal cell carcinoma. One patient developed nodular enhancement at 10 months with a decrease in lesion size. Watchful waiting was chosen because the patient had significant medical comorbidities.

CONCLUSIONS

Peripheral rim enhancement is a common finding on MRI immediately after laparoscopic renal cryoablation. Rim enhancement with an increase in lesion size or nodular enhancement is of more concern than rim enhancement alone. More data are necessary to understand the progression of renal lesions after cryoablation.

Third Prize:Prostaglandin E2-3 Receptor Is Involved in Ureteral Contractility in Obstruction

BACKGROUND AND PURPOSE

We previously found that prostaglandin (PG) E2 contracts acutely obstructed ureters while relaxing normal ureters. This study investigated the procontractile effects of the PG EP3 receptor in PGE(2)-mediated contractility in obstructed and normal porcine ureters.

MATERIALS AND METHODS

We created unilateral ureteral obstruction laparoscopically using titanium clips in farm pigs; the contralateral ureters were dissected as sham controls. Ureters were harvested 48 hours post-obstruction, cut into 5-mm segments, and suspended in water-jacketed tissue baths in Krebs buffer. Tissues were equilibrated for 1 hour, and spontaneous contractile rates were recorded. After 2 hours of incubation in Krebs (controls) or pertussis toxin (G(alpha)i signaling-protein inhibitor [EP-3 blockade]) 500 ng/mL, a concentration- response curve (10(-9) M-10(-5) M) to PGE(2), PGF(2), sulprostone (EP 3 agonist), or 0.01% ethanol (vehicle) was created (N = 4).

RESULTS

In the normal ureters, PGE(2) relaxed both pertussis toxin-treated and control tissues. In obstructed segments, PGE(2) increased contractions by 60%; this was reversed by pertussis toxin to a 67% reduction in contractile rate. In both obstructed and contralateral segments, sulprostone induced contractility in the controls; this was attenuated by pertussis toxin. The PGF(2) produced a contractile effect in both the controls and the pertussis toxin-treated segments, demonstrating the selectivity of pertussis toxin for EP3 receptors.

CONCLUSION

Our data indicate that the EP3 receptor is involved in hypercontractility during ureteral obstruction. However, it may not be the sole factor behind the condition-dependent effect of PGE(2).

Clinical utility of dual active deflection flexible ureteroscope during upper tract ureteropyeloscopy

OBJECTIVES

To evaluate the clinical utility of a dual active deflection ACMI DUR-8 Elite ureteroscope in a referral endourology practice.

METHODS

Retrospective chart review was performed on 54 consecutive patients who underwent flexible ureteroscopy by a single surgeon (S.Y.N.) from February to July 2003. Cases in which standard flexible ureteroscopes alone could complete the procedure, cases in which standard flexible ureteroscopy could not complete the procedure and the DUR-8 Elite ureteroscope did, and cases in which both ureteroscopes failed to complete the procedure were analyzed.

RESULTS

A total of 54 procedures were performed on 37 patients. Three cases were not analyzed because they were distal ureter procedures. Of the remaining 51 procedures, 6 were removed from analysis because they were second-look procedures. When classified by diagnosis, 27 patients had stones (79.4%), 5 had cancer (14.7%), and 1 had hematuria (2.9%). The global success rate was 91.1%. The average use rate of the DUR-8 was 28.9%, and the success rate using the DUR-8 Elite was 69.2% in those cases in which it was necessary. Of the 13 cases in which the DUR-8 was used, 61.5% were for lower pole pathologic findings. The DUR Elite use and success rate in the lower pole was 57.1% and 75%, respectively. A statistically significant association was found between the diagnosis and procedure location (P = 0.00128).

CONCLUSIONS

Our preliminary data indicate that the dual deflecting DUR-8 Elite ureteroscope may be helpful in cases in which the single deflection flexible instruments fail to access and treat upper urinary tract pathologic findings.

Routine pouchograms are not necessary after continent urinary diversion

OBJECTIVES

Pouchograms are routinely performed before catheter removal after continent urinary diversion at our institution. Our aim was to determine the necessity of pouchograms based on a review of our experience.

METHODS

A retrospective review of patient records and radiographic studies was done for patients undergoing radical cystectomy and continent urinary diversions between 1991 and 2001.

RESULTS

Seventy-two patients underwent continent urinary diversion (orthotopic, n = 59; cutaneous, n = 13) during the study period. All underwent pouchogram postoperatively (median 22 days; range 20 to 27). Six patients (8.3%) had a demonstrable radiographic leak; in 5 of the 6 patients, the urine leak was suspected on clinical grounds. Three patients (4.7%) developed urosepsis after pouchogram.

CONCLUSIONS

Our findings indicate that routine pouchograms before pouch activation after continent urinary diversion may not be necessary.

Urinary ascites secondary to forniceal rupture in a child with the Prune Belly Syndrome

Despite adequate bladder catheterization, a neonate with Prune Belly Syndrome developed urinary ascites secondary to forniceal rupture. Treatment consisted of bilateral cutaneous pyelostomies. Even though most children with Prune Belly Syndrome respond to lower urinary tract drainage, a cutaneous pyelostomy may be necessary when the ureters are tortuous and do not drain adequately following bladder decompression.

The surgical treatment of labial adhesions in pre-pubertal girls

STUDY OBJECTIVE

A review of our experience with the surgical treatment of labial adhesions refractory to medical treatment.

DESIGN

Retrospective review.

SETTING

University tertiary care hospital same-day surgery center.

PARTICIPANTS

Nine prepubertal females, age 3-6 yrs, presenting with thick, symptomatic labial adhesions refractory to medical management.

INTERVENTION

All patients underwent surgical lysis of labial adhesions under general anesthesia. Adhesions were incised sharply and the cut edges were reapproximated with 7-0 chromic suture by a pediatric urologist (JGB).

MAIN OUTCOME MEASURES

Duration of recurrence-free follow-up.

RESULTS

No patient had recurrence in an average of 8.6 months of follow-up. Surgery was well tolerated in all cases.

CONCLUSION

This technique effectively treats and prevents the recurrence of moderate to severe labial adhesions that are unresponsive to medical therapy.