bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2987: Comparison of the anticancer effects of Mitomycin-C and 5-Fluorouracil on novel periocular sebaceous carcinoma cell lines
Authors: Lang Steven H. , Gallo Ryan A. , Zhang Michelle G. , Tse David T. , Pelaez Daniel , Rong Andrew J.
Published: July 2021

Background: Sebaceous carcinoma (SC) is a highly malignant and potentially lethal neoplasm that most commonly arises from the ocular adnexa. Surgical management is the current mainstay of treatment; however, globe sparing tumor control is often complicated by pagetoid (or intraepithelial) invasion. Topical mitomycin-c (MMC) or 5-fluorouracil (5-FU) have been used as adjunctive medical therapy on the basis of their success in treating other ocular neoplasms. Yet, little is known of their effects on SC tumorgenicity. Here, we characterized effects of MMC and 5-FU in SC in vitro.

Methods: Periocular SC tissue samples were collected from two patients with histologically confirmed disease. This study was approved by the University of Miami Institutional Review Board and was conducted in a Health Insurance Portability and Accountability Act of 1996—compliant manner. Molecular characterization of the SC cells was done by immunocytochemistry and whole exome sequencing. SC cells were treated with MMC and 5-FU. The cytotoxic effects were evaluated using a viability assay and the kinetics of these effects were investigated by measuring cell proliferation over time. Migration capability of SC cells after drug treatment was examined by wound healing assays.

Results: Two SC cell lines, called Bascom Palmer 50 and 52 (BP50 and BP52), were established. Both cell lines retain the immunophenotypic and molecular features of SC. MMC reduced cell viability in both cell lines in a dose-dependent manner. MMC decreased SC cell proliferation and reduced overall cell number significantly compared to the untreated controls in a dose-dependent manner. MMC also inhibited SC migration capacity significantly. Conversely, 5-FU treatment did not affect cell viability or migration capacity in a dose-dependent fashion. While treatment with high-dose 5-FU inhibited SC proliferation, it did not reduce cell number below baseline.

Conclusions: We successfully generated SC cell lines and characterized the effects of MMC and 5-FU on these lines. Clinical medical management of periocular SC has been based of empirical data. Our findings suggest that MMC possess superior cytotoxic and cytostatic activity against SC compared to 5-FU in vitro. Taken together, these preliminary findings indicate that MMC may be more efficacious than 5-FU in the treatment of periocular SC. Currently, investigations are underway to identify novel therapeutic targets and test their efficacy in our cell lines.

Citation Format: Steven H. Lang, Ryan A. Gallo, Michelle G. Zhang, David T. Tse, Daniel Pelaez, Andrew J. Rong. Comparison of the anticancer effects of Mitomycin-C and 5-Fluorouracil on novel periocular sebaceous carcinoma cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2987.
Abstract 2988: Characterization of 3D models of human breast, prostate and colorectal cancer
Authors: Hudson Katie , Cross Neil , Jordan-Mahy Nicola , Leyland Rebecca
Published: July 2021

Tumorigenic expression of programmed death-ligand 1 (PD-L1) and its receptor PD-1 is found in many cancers, though the intrinsic roles of these proteins and how immunotherapy treatment may affect these pathways needs to be fully explored across human cancers. One platform to assess the expression and regulation of these proteins is 3D cell culture, which is thought to more closely mimic the architecture of solid tumors and more closely recapitulate in vivo human tumors in terms of cell heterogeneity, immunological and tumorigenic marker expression and treatment response, to investigate PD-L1/PD-1 signaling in cancer cells. Human breast (MDA-MB-231 and MCF-7), prostate (LNCaP and PC3) and colorectal (SW480 and SW620) cancer cell lines were cultured in both scaffold-free and scaffold-based 3D cell culture models to facilitate the formation of spheroids that display cell heterogeneity. 3D cancer models were analyzed by microscopy, qPCR and flow cytometry to assess the viability of spheroids, and measure any alterations in immunological and tumorigenic markers at mRNA and protein level, respectively, compared to their 2D monolayer counterparts. Breast, prostate and colorectal cancer cells cultured in 3D were highly viable over time and displayed significantly altered levels of immunological and tumorigenic marker expression at mRNA and/or protein level compared to their 2D monolayer counterparts. Importantly, PD-L1 expression changed in a 3D environment which may be linked to the increased cell-cell and cell-ECM interactions; increased expression of PD-L1 regulatory genes/proteins; or hypoxic regions that establish in 3D spheroids. The significantly altered expression levels of immunological and tumorigenic markers in a 3D cell culture environment is more likely to mimic that of an in vivo human tumor than standard 2D cell culture; allowing for optimized in vitro evaluation of the role of tumorigenic PD-L1/PD-1 and how immunotherapy treatment may affect these pathways.

Citation Format: Katie Hudson, Neil Cross, Nicola Jordan-Mahy, Rebecca Leyland. Characterization of 3D models of human breast, prostate and colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2988.
Abstract 299: Self-assembling peptide hydrogel for delivery and conversion of temozolomide in glioblastoma treatment
Authors: Pitz Megan , Nukovic Alexandra , Elpers Margaret , Wilde Sarah , Alexander-Bryant Angela
Published: July 2021

Traditional treatment methods for glioblastoma multiforme (GBM) including resection, radiation, and chemotherapy have been largely unsuccessful, with a current 5-year survival rate of 5.6%. In this project we examine the potential of nanosized self-assembling peptide hydrogels to locally deliver and convert temozolomide (TMZ), an FDA-approved pH-sensitive prodrug, for GBM treatment. The peptide hydrogel is designed to load TMZ into the hydrophobic regions of the hydrogels, and during hydrogel degradation in vivo, convert TMZ into its active form. Hydrogel characterization, drug loading and conversion, and cellular uptake and viability are examined to determine the in vitro efficacy of this delivery method. A combination of dynamic light scattering (DLS), scanning electron microscopy (SEM), and circular dichroism (CD) are used to characterize size and structure of the hydrogels. Loading and conversion of TMZ are quantified using UV-Vis spectroscopy. Fluorescent imaging and cell viability assays are used to determine uptake and anti-cancer effects of the drug-loaded hydrogels on glioblastoma cells. Our results show high uptake in drug-resistant T98G and non-resistant LN-18 glioblastoma cell lines using several of our tunable peptide formulations. CD has shown that all peptide formulations form mostly beta-sheet and random structures during self-assembly. SEM and DLS show that peptide hydrogels formed in a water solvent are more polydisperse than hydrogels in a PBS solvent. Using a pH-meter, we have shown that as the peptides in PBS degrade, there is an increase in local pH. Additionally, TMZ conversion is observed to occur more quickly in drug-loaded hydrogels than TMZ alone. Preliminary cell viability studies have shown that unassembled peptides are not cytotoxic; some of the assembled peptide hydrogels are cytotoxic while others maintain greater than 80% viability when compared to untreated cells. Future studies for the project will include cell viability assays with the most promising peptide formulations loaded with TMZ to determine efficacy of the delivery and conversion system. Finally, this project will culminate in an in vivo study to confirm the overall anti-cancer effect of the drug-loaded peptide hydrogels in a tumor model of GBM. Acknowledgements: This research was supported in part by the National Science Foundation EPSCoR Program under NSF Award # OIA-1655740, the National Institute of Health Award # P30GM131959, and National Science Foundation's Graduate Research Fellowship Program.

Citation Format: Megan Pitz, Alexandra Nukovic, Margaret Elpers, Sarah Wilde, Angela Alexander-Bryant. Self-assembling peptide hydrogel for delivery and conversion of temozolomide in glioblastoma treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 299.
Abstract 2990: In vitro drug sensitivity screening platform for primary chronic lymphocytic leukemia (CLL) patient samples
Authors: Vishwakarma Bandana Ajay , Wesa Amy
Published: July 2021

Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults. It is characterized by proliferation and accumulation of monoclonal, small, mature CD5+ B-cells in peripheral blood, bone marrow and secondary lymphoid organs. The current treatment regimens have improved overall survival but CLL patients will eventually experience relapse. The disease is still incurable making it a necessity to discover and screen for new drugs. Patient derived CLL specimens undergo spontaneous apoptosis when grown in culture and is a major limitation to screening for new therapeutic drugs. We have established an in vitro culture conditions which supports growth and proliferation of patient derived primary CLL cells. Champions has a bank of primary CLL patient samples across different Rai stage, genetic mutations and relapsed and refractory cases. We tested nine CLL samples (models) for proliferation. All nine models proliferated 1.5 to 9.6-fold in the optimized media in 6 days, as measured using CellTiter-Glo. Flow cytometric analysis showed that the CLL cells mostly retained the primary phenotypic characteristic CD5+CD10-Cd19+CD20+ even after being in the culture for 6 days. Next, we screened for sensitivity of primary CLL patient samples (N=9) against known standard of care (SOC) drugs venetoclax, ibrutinib, idelalisib, chlorambucil and cytarabine. Primary PBMC patient samples were seeded in 96 well plates in the enriched media and treated with respective drugs over a concentration range over 5 logs. Drug sensitivity was assessed using CellTiter-Glo® luminescent cell viability assay on day 6. Our in vitro assay indicated varied sensitivity of patient samples to approved standard of care drugs. A relapsed bendamustine pre-treated patient sample was sensitive to all the SOC drugs tested. In addition to drug response, whole exome sequencing and RNAseq are being conducted on these samples, to compare mutational analyses with drug responsiveness. With clinically annotated patient-derived CLL samples, WES and RNAseq plus drug response to standard of care provides a comprehensive ex vivo platform for the preclinical testing of drug candidates, which may not only provide information on agent efficacy, but that can permit potential biomarker mining and exploration of patient selection criteria for investigational new agents in CLL.

Citation Format: Bandana Ajay Vishwakarma, Amy Wesa. In vitro drug sensitivity screening platform for primary chronic lymphocytic leukemia (CLL) patient samples [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2990.
Abstract 3001: Multicellular structures of serous ovarian cancer nature isolated from pleural effusions are sufficient to recreate peritoneal carcinomatosis in immunosuppressed mice
Authors: Goyeneche Alicia A. , Sunassee Ashwyna , Ritch Sabrina J. , Koch Michael , Bell Maria , Gao Zu-hua , Telleria Carlos M.
Published: July 2021

High-grade serous ovarian cancer (HGSOC) is a lethal disease often diagnosed in grade III International Federation of Gynecology and Obstetrics (FIGO) upon colonization of the peritoneal cavity, or in grade IV FIGO when it colonizes the pleural cavity. When in the pleural cavity, the disease often manifests with accumulation of pleural effusions containing multicellular structures (MCS). In this work, we studied whether MCS isolated from a pleural effusion of a patient that did not respond to chemotherapy are sufficient to cause peritoneal carcinomatosis in immunosuppressed mice when implanted orthotopically. Nude mice were injected intraperitoneally with MCS isolated from the pleural effusions of a heavily treated patient. We determined the time taken for the disease to develop, the tissues targeted, presence or absence of ascites, the macroscopic and microscopic disease appearance, and the expression of standard biomarkers of HGSOC. We contrasted the histopathology of the tumors recreated in mice against that of the original tumor taken during diagnostic surgery. MCS from pleural effusions were sufficient to recreate disease in the mice, which reached their humane-endpoint seven months following MCS injection (n=3). The animals developed abundant cellular peritoneal ascites. In addition, macro and microscopic discrete disease was observed in the fat surrounding the ovaries, the omental-pancreatic area, the peritoneal wall, a lymph node, the diaphragm, and the lung. The histopathology of the disease showed infiltrating papillary architecture, areas with cells arranged in a solid pattern, and tumor nests with slit-like lumens that stained positive for mutant p53, p16, and WT1. Our results provide proof of principle that MCS isolated from pleural effusions of a HGSOC patient are sufficient to recreate peritoneal carcinomatosis in nude mice, depicting most morphological features found at postoperative diagnosis.

Citation Format: Alicia A. Goyeneche, Ashwyna Sunassee, Sabrina J. Ritch, Michael Koch, Maria Bell, Zu-hua Gao, Carlos M. Telleria. Multicellular structures of serous ovarian cancer nature isolated from pleural effusions are sufficient to recreate peritoneal carcinomatosis in immunosuppressed mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3001.
Abstract 3011: Cancer of Unknown Primary: novel therapeutic opportunities from patient-derived cell cultures and in vivo models
Authors: Laprovitera Noemi , Fumarola Claudia , Porcellini Elisa , Cairo Stefano , Gallerani Giulia , Gelsomino Francesco , Salamon Irene , Naddeo Maria , Ardizzoni Andrea , Cavazzoni Andrea , Ferracin Manuela
Published: July 2021

Patients with occult primary cancer or cancer of unknown primary (CUP) carry the double burden of an aggressive disease and reduced access to therapies, which are typically tumor-type oriented. Moreover, experimental in-vitro and in-vivo models summing up CUP features and heterogeneity are currently unavailable.

We derived and expanded two CUP cell lines, and corresponding patient-derived xenografts (PDXs), from ascites tumor cells. CUP cell lines, one spontaneously growing as organoid, and PDXs were subjected to histological, immune-phenotypical, molecular and genomic (CNV and target sequencing) characterization to show their ability to recapitulate the original tumor. MicroRNA profile and genomic information were used to identify a possible primary site and patient-specific therapeutic approaches. Data on CUP most frequently altered genes were used to design a custom CUP-specific, 92-gene panel for target NGS analysis with Sure Select XS technology (Agilent Technology).

Drug-screening assays were performed in vitro and in vivo on two models targeting the most promising actionable pathways. We obtained unexpected and promising results on drug combinations efficacy. This study brings personalized therapy closer to CUP patients and paves the way to future applications of personalized medicine for metastatic patients with adverse prognosis.

This work was supported by grants from the Italian Association for Cancer Research (AIRC) to MF (IG 18464).

Citation Format: Noemi Laprovitera, Claudia Fumarola, Elisa Porcellini, Stefano Cairo, Giulia Gallerani, Francesco Gelsomino, Irene Salamon, Maria Naddeo, Andrea Ardizzoni, Andrea Cavazzoni, Manuela Ferracin. Cancer of Unknown Primary: novel therapeutic opportunities from patient-derived cell cultures and in vivo models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3011.
Abstract 3027: Role of BCOR in retinoblastoma
Authors: Zhang Michelle Garying , Owens Dawn , Kurtenbach Stefan , Kuznetsov Jeffim , Fields Matthew , Pelaez Daniel , Harbour James W.
Published: July 2021

Retinoblastoma, which is usually initiated by the biallelic mutational inactivation of RB1, is the most common primary eye cancer in children and is fatal if left untreated. While retinoblastoma is initially sensitive to chemotherapy, it demonstrates a strong propensity for therapeutic escape, which is a leading cause of ocular morbidity, eye loss, and reduced survival. This problem is exacerbated by a poor understanding of how retinoblastoma progresses after the initial loss of RB1. Genomic analysis of primary retinoblastoma tumors has revealed the corepressor BCOR as the second most common target of mutations in retinoblastoma. Here, we explored the role of BCOR in normal retinal development to provide insights into its role in retinoblastoma. Mass spectrometry following immunoprecipitation of wildtype BCOR in primary retinoblastoma cells revealed novel BCOR interacting proteins in the Polycomb and MiDAC epigenetic complexes. Subsequent studies revealed potential functional consequences of BCOR mutation that may promote retinoblastoma progression. This work reveals new insights the role of epigenetic deregulation in retinoblastoma progression, and they nominate new candidates for therapeutic intervention.

Citation Format: Michelle Garying Zhang, Dawn Owens, Stefan Kurtenbach, Jeffim Kuznetsov, Matthew Fields, Daniel Pelaez, James W. Harbour. Role of BCOR in retinoblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3027.
Abstract 303: Surface modification of paclitaxel-loaded nanoparticles based on polydopamine with pH sensitive property for targeted therapy in hepatocellular carcinoma
Authors: Wu Mingfang , Xia Xinming , Sun Danna , Zhong Chen
Published: July 2021

Drug-loaded nanocarrier is a promising treatment for targeted therapy in hepatocellular carcinoma (HCC) due to their sustained release and outstanding tumor-targeting properties. Nevertheless, a limitation of current nanocarriers is the contradiction between multiple functions and favorable biocompatibility, owing to most of functional substances are non-biological. In this study, we introduced a targeting arginine-glycine-aspartic acid (RGD)-peptide on the surface of polydopamine (PDA)-ploy (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) to develop a novel nanoparticle, which were employed as a drug delivery system loaded with paclitaxel (PTX) for HCC therapy. Paclitaxel-loaded PHBV nanoparticles (PHBV-PTX-NPs) were prepared by emulsion solvent evaporation. As a gatekeeper, the pH-sensitive coating was formed by self-polymerization of dopamine. The RGD and PDA coated nanoparticles were combined through the Michael addition. The chemical structures and properties of these nanoparticles were characterized by dynamic light scattering-autosizer, transmission electron microscope, fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetry and X-ray photoelectron spectroscopy. As expected, these RGD-PDA-PHBV-PTX-NPs achieved excellent targeting efficiency, which was revealed by the cellular uptake and cytotoxicity assay in HCC cells. Compared with that of free PTX, the RGD-PDA-PHBV-PTX-NPs showed more superior antitumor efficacy in the xenograft mouse model. Notably, in addition to efficient anticancer activities, RGD-PDA-PHBV-PTX-NPs exhibited lower toxicity than PTX to normal hepatocytes and mouse in vitro and in vivo, respectively. These studies suggest the potential beneficial use of RGD-PDA-PHBV-PTX-NPs in future HCC-targeted therapy with drug-loaded nanocarriers.

Citation Format: Mingfang Wu, Xinming Xia, Danna Sun, Chen Zhong. Surface modification of paclitaxel-loaded nanoparticles based on polydopamine with pH sensitive property for targeted therapy in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 303.
Abstract 3042: Generation, characterization and functional validation of novel preclinical models for human pediatric glioma
Authors: Zohar Or , Moshe Itai , Britta Ismer , Jones David T. , Friedmann-Morvinski Dinorah
Published: July 2021

Tumors of the central nervous system are the most common form of childhood malignancy, and remain the leading cause of cancer-related morbidity and mortality in children. Despite extensive efforts, the efficacy of the traditional treatments is limited and the overall prognosis is poor. In recent years it has become apparent that pediatric gliomas differ from their adult counterparts, explaining in part why the therapies extrapolated from adult gliomas have failed, and further supporting the need to understand the biology of the childhood disease. Deep sequencing studies on brain tumor specimens within various cancer genome consortia (e.g. ICGC PedBrain, TCGA) has yielded a wealth of information about molecular aberrations that had accumulated in tumors. This has unravelled a considerable degree of heterogeneity and thus resulted in the delineation of different molecular subgroups. Furthermore, it has provided comprehensive insights into tumor genomes deduction. Nevertheless, validation of oncogenically relevant genes and therapeutically actionable targets in an in vivo context still remains a major challenge in the process of developing novel treatment approaches. We have generated state-of-the-art in vivo methodologies based on somatic gene transfer for generating animal models faithfully recapitulating the molecular and clinical characteristics of the respective human counterpart. In this study, we focused on NTRK2 fusions and FGFR1 mutations and characterized the tumors obtained by either in utero electroporation or lentiviral injection into postnatal (P0-P1) mice. Tumor derived cell lines grown in stem cell media were tested for conventional therapies (e.g. TMZ) and screening of available small inhibitor compounds. In addition, we have characterized the tumor microenvironment of these lesions, mainly the infiltrating immune cell populations. This study thus represents an important contribution to the understanding of pediatric glioma biology as well as to translational efforts in developing new treatment approaches for these malignant tumors.

Citation Format: Or Zohar, Itai Moshe, Ismer Britta, David T. Jones, Dinorah Friedmann-Morvinski. Generation, characterization and functional validation of novel preclinical models for human pediatric glioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3042.
Abstract 3046: In situ analysis of microenvironmental glycogen in Ewing's sarcoma patient samples by mass spectrometry imaging
Authors: Young Lyndsay E. , Conroy Lindsey R. , Clarke Harrison A. , Allison Derek B. , Drake Richard R. , Gentry Matthew S. , Sun Ramon C.
Published: July 2021

Ewing's sarcoma (ES) is a rare pediatric cancer of the bone and soft tissues affecting adolescents and young adults, with peak incidence from ages 10 to 15 years. A clinical feature of ES is the accumulation of Periodic acid-Schiff positive (PAS+) aggregates. PAS+ staining in ES histopathology analysis has been speculated to be glycogen accumulation, however, this has not been confirmed. To interrogate these aggregates, we developed a novel workflow for the high-sensitive detection of in situ glycogen via enzymatic release of glycogen substrates coupled to matrix assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) from formalin-fixed patient tissues. We utilized this method to study the nature of PAS+ staining in a cohort of ES patient samples surgically removed from tibia, rib, chest, shoulder, abdomen and testicle tissues. Using this innovative technique, we discovered profound intra-tumoral glycogen accumulation compared to adjacent stroma, normal, muscle and/or necrotic tissue. Further, intra-tumoral glycogen also has an increased phosphate content and distinct chain length profile compared to normal glycogen found in adjacent and patient-matched tissue. Notably, genetic manipulation and pharmacological inhibition of glycogen synthesis, or removal of glycogen phosphates, blunted ES tumor growth in xenografted mouse models. These findings suggest an important role of ES glycogen aggregates in tumor growth. Together, application of this novel MALDI-IMS technique, and the insights provided by formalin-fixed ES patient samples, reveals a distinct role of ES glycogen aggregates and uncovers a new therapeutic opportunity for this rare pediatric cancer.

Citation Format: Lyndsay E. Young, Lindsey R. Conroy, Harrison A. Clarke, Derek B. Allison, Richard R. Drake, Matthew S. Gentry, Ramon C. Sun. In situ analysis of microenvironmental glycogen in Ewing's sarcoma patient samples by mass spectrometry imaging [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3046.
Abstract 3049: Tumor treating fields induce DNA damage and apoptosis in medulloblastoma
Authors: Nitta Ryan T. , Li Gordon
Published: July 2021

Medulloblastoma (MB) is the most common malignant brain tumor in children and accounts for approximately 20% of all pediatric central nervous system tumors. Current multimodal treatment has led to a 70-90% five-year overall survival rate, however, the prognosis for patients with tumor dissemination and recurrent MB remains poor. Additionally, the majority of survivors exhibit long-term neurocognitive and neuroendocrine complications because of the cytotoxic drugs and high dose radiation. Consequently, more effective and less toxic treatments are necessary in order to raise the quality of life for these young patients. Tumor Treating Fields (TTFields) are an exciting new therapeutic opportunity for MB. TTFields are low intensity, alternating electric fields that disrupt cell division through physical interactions with key molecules during mitosis. The side effects from TTFields treatments are incredibly low, making it an ideal candidate for MB therapy. Currently TTFields were found to increase the survival of adult brain tumor patients by dysregulating the cytoskeletal network leading to mitotic arrest and as well as other varied multi-modal mechanisms of action. To determine if TTFields can be an effective treatment for MB, we conducted an in vitro study treating multiple MB cell lines with TTFields. We discovered that TTFields treatment reduced MB cell growth (Daoy, Med1-MB, D425, and D283) with an optimal frequency of 200-250 kHz. We also observed that TTFields treatment dysregulated actin polymerization that corresponded with a reduction in cell motility and invasion. TTFields treatment also caused DNA damage (γH2AX, 53BP1) that correlated with an increase in apoptotic cells. To expand on these initial findings, we conducted a combinatorial study with the small molecule inhibitor, CX-4945. CX-4945 is an inhibitor to casein kinase 2 and is currently being used in a phase I clinical trial to treat recurrent MB (NCT03904862). We discovered that CX-4945 enhanced the growth reduction of TTFields treatment. In addition, combining CX-4945 and TTFields increased the number of cells with dysregulated actin which correlated with a decrease in MB migration and invasion. Our findings demonstrate that TTFields may be a novel and less toxic method to treat MB patients.

Citation Format: Ryan T. Nitta, Gordon Li. Tumor treating fields induce DNA damage and apoptosis in medulloblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3049.
Abstract 308: Therapeutic implications of silver nanoparticles in the management of skin cancer
Authors: Dasari Shaloam R. , Tchounwou Paul B. , Yedjou Clement G. , Brodell Robert T. , Cruse Allison
Published: July 2021

Skin cancer (SC) is the most common carcinoma affecting 3 million people annually in the United Sates and millions of people worldwide. It is classified as melanoma skin cancer (MSC) and non-melanoma skin cancer (NMSC). NMSC represents approximately 80% of NMSC and includes squamous cell carcinoma (SCC) and basal cell carcinoma (BCC). MSC, however, has a higher mortality rate than SC because of its ability to metastasize. SC is a major health problem in the United States with significant morbidity and mortality in the Caucasian population. Treatment options for SC include cryotherapy, excisional surgery, Mohs surgery, curettage and electrodessication, radiation therapy, photodynamic therapy, immunotherapy, and chemotherapy. Treatments are chosen based on the type of skin cancer and the potential for side effects. Novel targeted therapies are being used with increased frequency for large tumors and for metastatic disease. The objective of this review is to highlight new chemotherapeutic agents that utilize silver nanoparticles in the management of SC. A scoping literature search on PubMed, Google Scholar, and Cancer Registry websites revealed that traditional chemotherapeutic drugs have little effect against SC after the cancer has metastasized. Following a discussion of SC biology, epidemiology, and treatment options, this review focuses on the mechanisms of advanced technologies that use silver nanoparticles in SC treatment regimens.

Citation Format: Shaloam R. Dasari, Paul B. Tchounwou, Clement G. Yedjou, Robert T. Brodell, Allison Cruse. Therapeutic implications of silver nanoparticles in the management of skin cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 308.
Abstract 3082: Synergistic inhibition of TNBC cell growth by novel doxorubicin/salinomycin-encapsulated dual drug-nanoparticles
Authors: Mohammad Anees , Tiwari Sachchidanand , Mehrotra Neha , Korczak Bozena , Appajosyula Sireesh , Laumas Steve , Kharbanda Surender M. , Singh Harpal
Published: July 2021

Triple negative breast cancer (TNBC) is an aggressive subtype with limited treatment options and a worse clinical outcome as compared with other breast cancer subtypes. Doxorubicin (DOX) is considered to be one of the most effective agents in the treatment. Unfortunately, resistance to DOX is very common due to drug efflux mediated by overexpression of ABC transporter. Recent studies suggest that cancer stem cells (CSCs) play an important role in tumorigenesis and biology of TNBC. Targeting CSCs may be a promising, novel strategy for the treatment of this aggressive disease. Recent studies have shown that salinomycin (SAL) preferentially targets the viability of CSCs. In the present study, SAL and DOX were co-encapsulated in polylactic acid (PLA)-based block copolymeric nanoparticles (NPs) (novel Quatramer Technology) to efficiently co-deliver these agents to treat TNBC cells. Generated SAL-DOX co-encapsulated dual drug NPs showed an average diameter of 91 ± 2 nm, zeta potential of -9.4 ± 1.1mV and PDI of less than 0.1. Both of these anti-cancer agents showed slow and sustained release profile in non-physiological buffer (PBS, pH 7.4) from these dual drug-encapsulated NPs. Additionally, multiple ratios (DOX:SAL = 3:1, 1:1, 1:3) were encapsulated to generate diverse dual drug NPs. The results demonstrate that, in contrast to 1:1 and 1:3, treatment of TNBC cells with 3:1 ratio of DOX:SAL dual drug NPs, was associated with significant inhibition of growth in vitro and more interestingly, was synergistic as compared to either agent alone. The IC50 of DOX and SAL in single drug-encapsulated NPs is 0.56 uM and 3.56 uM respectively. Importantly, the IC50 of DOX and SAL in dual drug-encapsulated NPs is 0.13 uM and 0.034 uM respectively. Furthermore, bi-weekly treatment of BALB/c wild-type mice harboring EAT cells (as syngeneic mouse model) with DOX-SAL (3:1) dual drug NPs at a dose of 3 mg/kg i.v. resulted in significant tumor growth inhibition (TGI). The TGI effect was synergistic with dual-NPs as compared to either agent alone. The TGI by dual drug NPs was without any significant effect on the body weights of the mice. These results demonstrate that a novel dual drug NP formulation of DOX and SAL in a unique ratio (3:1) represents an approach for successful targeting of CSCs and bulk tumor cells in TNBC and potentially other cancer types.

Citation Format: Anees Mohammad, Sachchidanand Tiwari, Neha Mehrotra, Bozena Korczak, Sireesh Appajosyula, Steve Laumas, Surender M. Kharbanda, Harpal Singh. Synergistic inhibition of TNBC cell growth by novel doxorubicin/salinomycin-encapsulated dual drug-nanoparticles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3082.
Abstract 3084: KLF8 is a required downstream effector of OGT/O-GlcNAcylation in regulating breast cancer stem-like cells
Authors: Minh Giang Le , Akella Neha M. , Dhameliya Tejsi , Reginato Mauricio J.
Published: July 2021

One of the main challenges in treating breast cancer is the intra-tumor heterogeneity, which, partly, is maintained and promoted by a sub-population of breast cancer cells called breast cancer stem-like cells (BCSCs). BCSCs shares traits of mammary stem cells, capable of self-renewing and differentiating, while promotes invasion, metastasis, drug resistance and relapse. BCSCs are highly adaptive, capable of reprogramming metabolism and signaling activity in response to tumor microenvironment. One key component of cell nutrient sensing mechanism, linking alteration in metabolism to cell signaling, is O-GlcNAc transferase (OGT). OGT is responsible to adding O-GlcNAc moieties to target nuclear, cytoplasmic and mitochondrial proteins from UDP-GlcNAc - final product of the hexosamine biosynthetic pathway. This modification is termed O-GlcNAcylation and both OGT and O-GlcNAcylation are upregulated in many cancers. Recently, we showed that OGT/O-GlcNAcylation is enriched in BCSCs, promoting the stemness and tumorigenesis of breast cancer cells in vitro and in vivo. RNA-seq analysis of BCSC-enriched mammospheres with OGT overexpression revealed Kruppel-like-factor 8 (KLF8) as a downstream target of OGT in promoting BCSCs. Here, we showed that KLF8 expression in breast cancer cells is regulated by OGT at protein and mRNA level. Knockdown of KLF8 reduced mammosphere forming efficiency (MFE) and NANOG expression in breast cancer cells, while overexpressing KLF8 increased MFE, NANOG+ and CD44H/CD24L BCSC population. Importantly, KLF8 knockdown abolished the effect of elevated OGT and O-GlcNAcylation in breast cancer cell MFE and BCSC population, while KLF8 overexpression rescued OGT inhibition in MFE and BCSC population. suggesting that KLF8 is required in promoting BCSCs. Interestingly, KLF8 knockdown in breast cancer cell reduced OGT expression, while KLF8 overexpression increased OGT and O-GlcNAcylation, suggesting a possible feed-forward loop between OGT and KLF8 in promoting BCSCs. Supporting the idea that KLF8 and OGT are critical for breast cancer progression, breast cancer patient survival was lower with high KLF8 or OGT levels. Furthermore, overexpression of KLF8 showed increase in resistance to paclitaxel in triple-negative breast cancer cells in vitro, suggesting a possible role of KLF8 in promoting chemotherapy resistance in breast cancer[LM1] . Together, our results suggested that KLF8 is a downstream target of OGT/O-GlcNAcylation in promoting breast cancer stem-like cells population.

Citation Format: Giang Le Minh, Neha M. Akella, Tejsi Dhameliya, Mauricio J. Reginato. KLF8 is a required downstream effector of OGT/O-GlcNAcylation in regulating breast cancer stem-like cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3084.
Abstract 3085: Steroid receptor co-activators regulate metabolic kinases to drive therapy resistant ER+ breast cancer
Authors: Truong Thu Ha , Benner Elizabeth , Hagen Kyla M. , Temiz Nuri A. , Kerkvliet Carlos Perez , Wang Ying , Cortes-Sanchez Emilio , Yang Chieh-Hsiang , Pengo Thomas , Guillen Katrin P. , Welm Bryan E. , Telang Sucheta , Lange Carol A. , Ostrander Julie H.
Published: July 2021

Recurrence of metastatic breast cancer stemming from acquired endocrine and chemotherapy resistance remains a health burden for women with luminal (ER+) breast cancer. Disseminated ER+ tumor cells can remain viable but quiescent for years to decades. Contributing factors to metastatic spread include the maintenance and expansion of breast cancer stem cells (CSCs). Breast CSCs are poorly proliferative and frequently exist as a minority population in therapy resistant tumors. Our objective is to define novel signaling pathways that govern therapy resistance in ER+ breast cancer. In this study, we show that cytoplasmic complexes composed of steroid receptor (SR) co-activators, PELP1 and SRC-3, modulate breast CSC expansion through upregulation of the HIF-activated metabolic target genes PFKFB3 and PFKFB4. Seahorse metabolic assays demonstrated that cytoplasmic PELP1 influences cellular metabolism by increasing both glycolysis and mitochondrial respiration. PELP1 interacts with PFKFB3 and PFKFB4 proteins, and inhibition of PFKFB3 and PFKFB4 kinase activity blocks PELP1-induced tumorspheres and protein-protein interactions with SRC-3. PFKFB4 knockdown inhibited in vivo emergence of circulating tumor cell (CTC) populations in ER+ mammary intraductal (MIND) xenografts. Application of PFKFB inhibitors in combination with ER targeted therapies blocked tumorsphere formation in multiple models of advanced breast cancer, including tamoxifen (TamR) and paclitaxel (TaxR) resistant models and ER+ patient-derived organoids (PDxO). Together, our data suggest that PELP1, SRC-3, and PFKFBs cooperate to drive ER+ tumor cells that include CSCs and CTCs. Identifying non-ER pharmacological targets offers a useful approach to blocking metastatic escape from standard of care ER/estrogen (E2)-targeted strategies to overcome endocrine and chemotherapy resistance in ER+ breast cancer.

Citation Format: Thu Ha Truong, Elizabeth Benner, Kyla M. Hagen, Nuri A. Temiz, Carlos Perez Kerkvliet, Ying Wang, Emilio Cortes-Sanchez, Chieh-Hsiang Yang, Thomas Pengo, Katrin P. Guillen, Bryan E. Welm, Sucheta Telang, Carol A. Lange, Julie H. Ostrander. Steroid receptor co-activators regulate metabolic kinases to drive therapy resistant ER+ breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3085.
Abstract 3107: HSB-1216, A Novel Agent for the Treatment of Chemotherapy-Resistant ES-SCLC
Authors: Mohammad Anees , Tiwari Sachchidanand , Mehrotra Neha , Korczak Bozena , Laumas Steve , Appajosyula Sireesh , Singh Harpal , Kharbanda Surender M.
Published: July 2021

Small cell lung cancer (SCLC) is a highly malignant form of lung cancer that accounts for 15% of lung cancer cases. The tumor has a tendency to disseminate early resulting in ~ 85% patients being diagnosed with extensive stage disease (ES-SCLC). Chemotherapy has been the mainstay of treatment for many decades, until recently when immunotherapeutic agents have been approved as first-line agents. However, resistance to anti-cancer drugs represents the main cause of cancer-related deaths. Thus, new therapeutic approach to suppress chemotherapy-resistant ES-SCLC constitutes a significant unmet medical need. We have generated novel biodegradable QUATRAMERTM polymeric nanoparticles comprised of a polyethylene glycol (PEG)-polypropylene glycol (PPG)-PEG- polylactic acid (PLA)-tetra-block copolymer for the intracellular delivery of salinomycin (HSB-1216). Here we studied the HSB-1216 activity in a resistant SCLC cell line (NCI-H69AR). Compared to cisplatin and irinotecan, a second-line agent often used in ES-SCLC, HSB-1216 exhibited a ~7-fold and ~2-fold decrease in IC50in the aggressive and resistant variant of NCI-H69AR cell line and ~30-fold and ~18-fold decrease in a non-resistant NCI-H69 SCLC line. The tumorsphere formation assay has become an essential tool for quantifying cancer stem cells (CSC) and testing of anti-cancer agents. We used this assay to estimate an effect of HSB-1216 on NCI-H69AR tumorspheres .Our results demonstrated significant dose-dependent inhibition of tumorosphere formation in response to HSB-1216. In addition, exposure to HSB-1216 resulted in substantial decrease in number of CD44+/CD24- cells in comparison to untreated control. Furthermore, significant reduction in the expression of CSC markers such as ALDH1 and Oct3/Oct4 was seen when chemotherapy-resistant NCI-H69AR cells were treated with HSB-1216.Taken together, based on these findings, HSB-1216 is being developed as a novel agent in the treatment of second-line ES-SCLC in chemo-resistant tumors, where a gap exists in current standards of care. Further work of this novel agent is planned to outline its effect when combined with targeted and non-targeted therapies in both first- and third-line SCLC.

Citation Format: Anees Mohammad, Sachchidanand Tiwari, Neha Mehrotra, Bozena Korczak, Steve Laumas, Sireesh Appajosyula, Harpal Singh, Surender M. Kharbanda. HSB-1216, A Novel Agent for the Treatment of Chemotherapy-Resistant ES-SCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3107.
Abstract 3112: Human melanocyte development and melanoma dedifferentiation at single cell resolution
Authors: Belote Rachel L. , Le Daniel , Maynard Ashley , Lang Ursula E. , Sinclair Adriane , Planells-Palop Vincente , Baskin Laurence S. , Tward Aaron D. , Darmanis Spyros , Judson-Torres Robert L.
Published: July 2021

In humans, epidermal melanocytes are responsible for skin pigmentation, defense against ultraviolet radiation, and the deadliest common skin cancer, melanoma. While there is substantial overlap in melanocyte development pathways between different model organisms, species dependent differences are frequent and the conservation of these processes in human skin remains unresolved. Thus, the biology of developing and adult human melanocytes remains largely uncharacterized. Here, we used a single-cell enrichment and RNA-sequencing pipeline to study human epidermal melanocytes derived directly from skin, capturing transcriptomes across different anatomic sites, developmental age, sexes, and multiple skin tones. Using donor-matched skin from distinct volar and non-volar anatomic locations, we uncovered subpopulations of melanocytes exhibiting site-specific enrichment that occurs during gestation and persists through adulthood. In addition, we identified human melanocyte differentiation transcriptional programs that are distinct from gene signatures generated from model systems. Finally, we use these programs to define patterns of dedifferentiation that are predictive of melanoma prognosis. Overall, the characterization of human melanocytes fresh from skin revealed new subpopulations, human-specific transcriptional programs, and valuable insights into melanoma dedifferentiation.

Citation Format: Rachel L. Belote, Daniel Le, Ashley Maynard, Ursula E. Lang, Adriane Sinclair, Vincente Planells-Palop, Laurence S. Baskin, Aaron D. Tward, Spyros Darmanis, Robert L. Judson-Torres. Human melanocyte development and melanoma dedifferentiation at single cell resolution [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3112.
Abstract 3116: Designing a model system for the study of CD44-Ezrin interactions in breast cancer progression and drug resistance
Authors: Birtch Rayanna Jane , Greer Peter , Gao Yan , Hoskin Victoria
Published: July 2021

Triple-negative breast cancer (TNBC) has the highest risk of relapse and is thought to be the most aggressive subtype of BC. This subtype is known to express high levels of the cancer stem cell (CSC) marker CD44. The tumor-initiating properties of CSC's, as well as their resistance to chemotherapy, contribute to the difficulty in successfully treating TNBCs.CD44 is a transmembrane glycoprotein that mediates communication between cells and the extracellular matrix. In doing so, it acts as a central node in several cancer-related signaling pathways through interactions with binding partners such as Ezrin to promote tumor growth, invasion and survival. Furthermore, expression of CD44 is associated clinically with positive lymph node status, recurrence and poor overall survival in BC. We aimed to validate CD44's role in these cancer promoting properties and develop a genetically tractable and engraftable TNBC cell model to study CD44 in the context of interactions with the Ezrin adaptor protein. We first hypothesize that disrupting CD44 expression will attenuate the metastatic and drug resistant potential of TNBC cells. To address this, we utilized CRISPR-Cas9 gene editing to knockout (KO) CD44 expression in the MDA-MB-231 human TNBC cell line and then subjected CD44 KO cells, KO cells rescued with wild type CD44, or the parental MDA-MB-231 cells to a variety of in vitro assays to assess proliferative, migratory and drug resistant potential, as well as mouse lung metastatic seeding in vivo. We show that the transmembrane glycoprotein CD44 plays an important role in cancer cell proliferation, migration, and chemotherapeutic resistance in vitro as well as having an essential role in metastatic seeding in vivo in the MDA-MB-231 cell model of TNBC. Our results validate the utility of this CRISPR-Cas9 KO and rescue TNBC cell model for the study of CD44 involvement in drug resistance and metastasis. More importantly we have set the stage for further investigating CD44's role in the context of interactions with the Ezrin adaptor protein.

Citation Format: Rayanna Jane Birtch, Peter Greer, Yan Gao, Victoria Hoskin. Designing a model system for the study of CD44-Ezrin interactions in breast cancer progression and drug resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3116.