bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1513: FASN inhibition-induced BRCAness as a therapeutic option for castration-resistant prostate cancer (CRPC)
Authors: Ribeiro Caroline Fidalgo , Rodrigues Silvia D. , Bastos Debora C. , Pakula Hubert , Zadra Giorgia , Foiani Marco , Loda Massimo 
Published: June 2022

Abstract
Androgen deprivation therapy (ADT) is the primary treatment for prostate cancer. However, resistance to ADT invariably develops, leading to castration-resistant prostate cancer (CRPC). Prostate cancer progression is marked by overexpression of fatty acid synthase (FASN) and increased de novo synthesis of fatty acids. Importantly, the majority of normal tissues have low expression of FASN and rely mostly on exogenous lipids, making FASN an interesting therapeutic target for prostate cancer. Previously our group evaluated the effects of inhibiting FASN in prostate cancer, with especially promising results in CRPC models. We observed that FASN inhibition decreases DNA damage repair capability by transcriptionally modulating homologous recombination (BRCAness) and non-homologous end joining repair pathways, which leads to increased DNA damage and apoptosis. Key enzymes involved in DNA repair pathways are reduced at the protein level, and the addition of exogenous palmitate, the product of FASN, is able to rescue their expression to normal levels. Interestingly, genes involved in the synthesis of ceramide are upregulated after FASN blockade, with consequent increased cellular levels of ceramides, dihydroceramides and sphingomyelin. Additionally, we observed increased acyl chain unsaturation levels in these lipid species, in line with the uptake of polyunsaturated fatty acids (PUFA) observed when de novo lipogenesis is blocked. The inhibition of ceramide synthesis, both through genetic knock-down with siRNA or pharmacologically with an inhibitor of serine palmitoyltransferase, is capable of partially rescuing the DNA damage induced by FASN inhibition, suggesting a role of ceramides in DNA damage response modulation. Next, we investigated the synergistic effect of combining FASN inhibitor with PARP inhibitor and observed a higher inhibition of cell growth in prostate cancer cell lines in comparison to either drug alone. Human CRPC organoids when treated with PARP and FASN inhibitor in combination showed reduced diameter, as well as reduced cell proliferation, when compared with each agent alone. Overall, our data demonstrate that targeting de novo lipogenesis can increase the therapeutic efficacy of PARP inhibitors and benefit prostate cancer patients that do not harbor BRCA mutations, by pharmacologically downregulating DNA damage repair pathways, particularly HR.
Citation Format: Caroline Fidalgo Ribeiro, Silvia D. Rodrigues, Debora C. Bastos, Hubert Pakula, Giorgia Zadra, Marco Foiani, Massimo Loda. FASN inhibition-induced BRCAness as a therapeutic option for castration-resistant prostate cancer (CRPC) [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 1513.
Abstract 1516: The role of protein tyrosine kinases in DNA mismatch repair
Authors: Daniels Hannah , Knicely Breanna , Goellner Eva M. 
Published: June 2022

Abstract
The DNA mismatch repair (MMR) pathway and its regulation are necessary for genomic stability. Cells deficient in MMR exhibit increased expansion and contraction of short repeat sequences in the genome, termed microsatellite instability (MSI). Loss of MMR also results in resistance to certain classes of DNA damaging chemotherapeutics. The standard treatment option for most patients includes chemotherapy, which has toxic side effects. Immunotherapy has recently been utilized as a treatment for various cancers. MSI-high cancers respond better to immunotherapy treatment compared to microsatellite stable (MSS) cancers. This increased response is believed to be due to the higher mutation frequencies associated with the MSI-high tumors, which lead to greater neoantigen production. The primary proteins required for MMR are known, however regulation of the pathway is not well understood. The MLH1 protein is critical for MMR and is required for the excision licensing of the daughter DNA strand. Loss or mutation of MLH1 leads to defective MMR, increased mutation frequency, and MSI. Recent studies by our laboratory and others have shown that treatment with a tyrosine kinase inhibitor, Imatinib, leads to decreased MLH1 protein expression, and resistance to MMR-dependent apoptosis. These observations suggest a link between Imatinib-sensitive protein tyrosine kinases (PTKs) and the regulation of MMR. We show that MLH1 protein reduction is not occurring at the mRNA level and is thought to be post-transcriptional. We have identified the Imatinib sensitive target most likely responsible for the MLH1 reduction phenotype. We show that the target protein and MLH1 have a physical interaction that likely prevents degradation targeting of MLH1 by the Hsp70 chaperone. A detailed understanding of MMR regulation by PTKs would significantly advance the knowledge in the field of MMR and have important implications for immunotherapy strategies.
Citation Format: Hannah Daniels, Breanna Knicely, Eva M. Goellner. The role of protein tyrosine kinases in DNA mismatch repair [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 1516.
Abstract 152: Discovery and characterization of GSK3 allosteric activators
Authors: Varghese Reeba P. , Thorne Curtis A. 
Published: June 2022

Abstract
The intestinal epithelium undergoes constant regeneration and is tightly regulated. Disruption of its homeostasis can result in the development of colorectal cancer (CRC). Glycogen synthase kinase 3 (GSK3) is a kinase that plays a central role in multiple signaling pathways, including cellular proliferation, where it inhibits the activity of its substrates. GSK3 dynamics can be described as a multiple input multiple output system. Numerous upstream growth factors can regulate and thus inhibit GSK3 from acting on its many substrates. Mutations in these growth signaling pathways (e.g., Wnt and KRAS) have been well established to have a role in CRC progression. Therefore, aberrantly activated signaling due to these proteins are presumed to result in the constitutive inhibition of GSK3 activity in CRC, thus making it an ideal therapeutic target. The aim of this study is to discover an allosteric GSK3 small molecule activator that can restore GSK3 kinase activity within CRC. Method: We screened 50,000 small molecule compounds using a luciferase-based in-vitro kinase assay. We are further confirming our top hits using both chemical and cell-based assays. For the cell-based assays, we test the compounds in human colonic epithelial cells (HCEC) and its three isogenic cell lines, which mimic CRC progression, and monitor changes in GSK3 kinase activity indirectly, via changes in its substrate protein levels, and directly via a live-cell GSK3 specific reporter. In addition, the top hits are also tested in both normal colon and CRC organoids. Results: Prior to running our large screen, we performed various optimization steps to determine the ideal condition for our screening assay. Our screening assay scored a Z-Score of 0.5 and higher, which indicated that it was a high-quality screening assay. Additionally, we have developed two cell-based orthogonal HTS assays. One using immunofluorescence and single-cell quantification of 24 GSK3 substrates from various pathways in our cell lines. Second, we engineered a GSK3 live-cell reporter and expressed it in the HCEC cells and three isogenic cell lines and organoid models. Impact: There is a need for advancements in preventative or therapeutic targets against CRC. Research indicates that suppression of GSK3 enzymatic activity decreases sensitivity to certain chemotherapeutic and targeted therapies. Therefore, restoring GSK3 enzymatic activity in CRC may re-sensitize tumors to other targeted therapies and establish GSK3 as a potential therapeutic target.
Citation Format: Reeba P. Varghese, Curtis A. Thorne. Discovery and characterization of GSK3 allosteric activators [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 152.
Abstract 1523: Beta-2 adrenergic receptor and mu opioid receptor interact to increase the aggressiveness in triple negative breast cancer cells through activation of GSK3 signaling
Authors: Rousseau Bénédicte , Murugan Sengottuvelan , Palagani Ajay , Sarkar Dipak K. 
Published: June 2022

Abstract
Breast cancer is the world’s leading cause of cancer mortality in women worldwide. It has been shown that body stress hormones, such as norepinephrine, and opioid peptides interact to control the growth and progression of this cancer. Opioid and beta-adrenergic receptors are recently shown to cross talk via formation of receptor heterodimers to control cellular functions in various cell systems. However, the underlying cell signaling mechanism remains unclear. To determine the effect of the interaction of the two systems in breast cancer, we employed triple-negative breast cancer (TNBC) cell lines MDA-MB-231 and MDA-MB-468, CRISPR, chemical inhibition or activation and, PCR Array technology to study aggressive tumor phenotype and signaling cascades. We found that knock down of the beta-adrenergic (B2AR) or mu-opioidergic receptor (MOR) system via the CRISPR technique or pharmacological agents induces a less aggressive phenotype in triple negative breast cancer cells both in vitro and in vivo, with the effect being potentiated when both receptor systems were inhibited together. The mRNA expression study using a PCR Array targeting Cancer Stem Cell genes shows that B2AR or MOR activated the glycogen synthase kinase 3 (GSK3) signaling cascade. The GSK3 inactivation in MDA-MB-231 and MDA-MB-468 cells induced similar phenotypic changes as was done by the inhibition of B2AR and/or MOR, while a GSK3 activation by wortmannin reversed the effects of B2AR and/or MOR knockdown on these cells. GSK3 inactivation also prevents B2AR agonist norepinephrine or MOR agonist DAMGO from affecting MDA-MB-231 and MDA-MB-468 cell proliferation. These data identify a role of B2AR and MOR interaction in the control of breast cancer cell growth and establish a possible role of the GSK3 signaling system in mediation of these two receptors’ cross talk. (Supported by NIH grant R01 CA20863201).
Citation Format: Bénédicte Rousseau, Sengottuvelan Murugan, Ajay Palagani, Dipak K. Sarkar. Beta-2 adrenergic receptor and mu opioid receptor interact to increase the aggressiveness in triple negative breast cancer cells through activation of GSK3 signaling [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 1523.
Abstract 1524: Expression of GDNF and its receptors in glioblastoma
Authors: Ewald Jesper D. , Knudsen Arnon M. , Kristensen Bjarne W. 
Published: June 2022

Abstract
Introduction: Glioblastoma is the most aggressive primary brain cancer and one of the most lethal types of cancer overall. Despite multimodal treatment strategies, the prognosis is poor with a median survival of approx. 15 months. Although neurotrophic factors are of major importance in the nervous system, their role in brain cancer is still not fully understood. We focused on the glial cell line-derived neurotrophic factor (GDNF), which has been shown to play a role in growth and migration in glioblastoma. The aim of this study was to investigate the expression of GDNF and it primary receptor GFRA1, as well as the other GDNF family receptors GFRA2-4 and RET.
Methods: Tissue sections from 10 glioblastoma patients were stained with antibodies against GDNF and each of the receptors. GDNF stainings were performed on frozen tissue slides, while receptor stainings were performed on formalin-fixed paraffin-embedded tissue sections. The area fractions of positive staining were quantified with a software-based classifier. Double immunofluorescence stainings with the different markers and Iba1 as well as GFAP were performed to assess expression in microglia/macrophages and tumor cells, respectively.
Results: GDNF staining was observed in five of ten patient specimens, whereas GFRA1 and GFRA2 staining was observed in all samples. GFRA1 and GFRA2 staining was seen in the membrane and cytoplasm with a mean area fraction of GFRA1 staining at 31% (range: 7-56%), and a mean area fraction of GFRA2 staining at 3% (range: 0.2-7%). GFRA3, GFRA4 and RET were not expressed in glioblastoma tissue. Double immunofluorescence stainings demonstrated co-expression of GFRA1 and GFAP, while co-expression of GFRA1 and IBA1 was limited.
Conclusion and perspectives: Our results suggest that GDNF and GFRA1 are widely expressed in glioblastoma tumor tissue, but GFRA2 is also expressed and may play a role in glioblastoma biology. Additional stainings are being established to clarify cellular expression and expression levels of GDNF and its receptors.
Citation Format: Jesper D. Ewald, Arnon M. Knudsen, Bjarne W. Kristensen. Expression of GDNF and its receptors in glioblastoma [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 1524.
Abstract 1526: Circulatory insulin-like growth factor 1 predicts metastasis in triple-negative breast cancer
Authors: Akter Salima , Faruque Mithila , Akhter Hajara , Bhowmik Mousumi , Hasan Mohammad Nazmul , Sultana Lipika , Khan Imran , Mia Mamun , Rahman Md. Mustafizur , Chaudhury Habib Sadat , Rafiqul Islam S. , Nahar Kamrun , Choi Tae Gyu , Kim Sung Soo 
Published: June 2022

Abstract
Background and aims: Aberrant insulin-like growth factor (IGFs) signaling is directly implicated in oncogenesis and metastasis in various solid tumors including breast cancer. Targeting the IGF axis may provide an insight into the mechanism of cancer stemness and therapy resistance. The present study aims to explore the association of the circulatory levels of these proteins in aggressive triple-negative breast cancer (TNBC) in Bangladesh.
Methods: A total of 165 BC patients were recruited in the present study where 42 were TNBC subjects (selected based on their complete hormonal profile). Data were collected from retrospective information. Anthropometric and biochemical parameters were measured by standard methods. Serum IGF1, IGFBP1, and insulin were estimated by ELISA.
Results: TNBC subjects showed significantly higher levels of circulatory IGF1 (185 vs 145, p=0.004), while patients who had distant metastasis showed increased levels of IGF1, IGFBP1, and alkaline phosphatase (ALP) [178 vs 153, p=0.001; 6.44 vs 3.05, and 140 vs 88, p&lt;0.05; metastatic vs non-metastatic BC respectively]. In addition, serum IGF1 was positively associated with serum insulin levels and IGFBP1 was associated with ALP, SGPT, CA15.3, and duration of OCP (p&lt;0.05). In multivariate regression, IGF1 was found to be a significant predictor of breast cancer survival after adjusting confounding variables.
Conclusion: High serum levels of IGF1 may contribute to metastasis in basal breast cancer in a Bangladeshi population. These results need to be confirmed in larger TNBC survivor cohorts.
Citation Format: Salima Akter, Mithila Faruque, Hajara Akhter, Mousumi Bhowmik, Mohammad Nazmul Hasan, Lipika Sultana, Imran Khan, Mamun Mia, Md. Mustafizur Rahman, Habib Sadat Chaudhury, Islam S. Rafiqul, Kamrun Nahar, Tae Gyu Choi, Sung Soo Kim. Circulatory insulin-like growth factor 1 predicts metastasis in triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1526.
Abstract 153: An unbiased in vitro screen for activating ERBB4 mutations
Authors: Chakroborty Deepankar , Ojala Veera K. , Knittle Anna M. , Kurppa Kari J. , Elenius Klaus 
Published: June 2022

Abstract
Introduction: Cancer tissues harbor thousands of mutations, and a given oncogene may be mutated at hundreds of sites across different samples. The discovery of most of the currently known driver mutations has been facilitated by their accumulation in mutation hotspots within their respective genes. However, a vast majority of mutations in cancer tissues are rare and their functional significance remains unknown. Several lines of in vitro and clinical evidence also indicate that there is a significant number of, as yet unidentified, activating driver mutations which could serve as predictive markers in oncology. Here, we performed an unbiased functional screen to identify potential activating mutations of ERBB4, a frequently mutated member of the epidermal growth factor receptor family.
Method: To identify functional driver mutations of ERBB4, the previously published pipeline, in vitro screen for activating mutations (iSCREAM) [1], was utilized. iSCREAM is a functional genetics screen based on the expression of random cDNA variants and the ability of driver mutations to promote cellular growth in vitro. The expression library encoding randomly mutated ERBB4 variants was retrovirally introduced into murine lymphoid Ba/F3 cells, that normally require interleukin-3 (IL-3) for survival but can exploit ectopic expression of activated variants of oncogenic kinases to compensate for the deficiency of exogenous IL-3. When expressed under an appropriate promoter, the wild-type ERBB4 receptor failed to promote IL-3-independent survival in the presence of the neuregulin-1 ligand, while the cells expressing activating mutations readily proliferated. The identity and frequency of the activating ERBB4 mutations were subsequently determined from the proliferating cell pool using targeted next-generation sequencing.
Results: Ten candidate activating mutations were identified out of the over 7000 random ERBB4 missense or nonsense mutations present in the original library. The candidate activating mutations were individually characterized using functional assays both in vitro and in vivo, as well as by structural analyses. The activating mutation were sensitive to clinically used pan-ERBB tyrosine kinase inhibitors afatinib, dacomitinib and neratinib.
Conclusions: A subset of ERBB4 missense mutations are activating and sensitive to tyrosine kinase inhibitor drugs.
Citation Format: Deepankar Chakroborty, Veera K. Ojala, Anna M. Knittle, Kari J. Kurppa, Klaus Elenius. An unbiased in vitro screen for activating ERBB4 mutations [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 153.
Abstract 1531: CD146 couples and sequesters regulatory kinases to control breast cancer cell state plasticity
Authors: Balcioglu Ozlen , Gates Brooke L. , Freeman David W. , Hagos Berhane M. , Spike Benjamin T. 
Published: June 2022

Abstract
CD146 (Mcam; Muc18; s-endo; and gicerin) is an integral membrane glycoprotein originally identified in a human malignant melanoma, but mis-expressed in a wider variety of malignancies including breast cancer, where it has been implicated in controlling tumor growth and dissemination. The mechanisms by which CD146 conveys extracellular cues into malignant cellular outputs is not well understood, but its high-level expression in early development and normal mouse mammary stem cells, as well as expression in highly plastic adult pericytes (formerly known as mesenchymal stem cells) suggested to us that it may control cell state plasticity. We tested the role of CD146 in a plastic, stem cell-like mouse mammary tumor cell line derived from the MMTV-PyMT mouse (PY230). We identified domains in the CD146 cytoplasmic tail essential for controlling substrate utilization by upstream kinases in Akt, Mapk, Stat3, and integrin-related signaling pathways that alter cell state plasticity and tumorigenicity. This work suggests that MCAM plays a key role in controlling lineage plasticity in normal and neoplastic mammary cells with relevance for understanding tumor cell plasticity, progression and evasion of targeted cancer therapies.
Citation Format: Ozlen Balcioglu, Brooke L. Gates, David W. Freeman, Berhane M. Hagos, Benjamin T. Spike. CD146 couples and sequesters regulatory kinases to control breast cancer cell state plasticity [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 1531.
Abstract 1539: LKB1 down-modulation by miR-17 biologically and clinically mirrors LKB1-mutated NSCLC
Authors: Borzi Cristina , Ganzinelli Monica , Caiola Elisa , Colombo Marika , Centonze Giovanni , Boeri Mattia , Caleca Laura , Pastorino Ugo , Marabese Mirko , Milione Massimo , Broggini Massimo , Garassino Marina C. , Sozzi Gabriella , Moro Massimo 
Published: June 2022

Abstract
Introduction: In non-small cell lung cancer (NSCLC) LKB1 mutations combined with KRAS hyperactivation define a poor responsive, aggressive and disseminating phenotype. We recently unveiled the vulnerability of KRAS/LKB1 co-mutated (KL) patient-derived xenografts (PDXs) to metabolic stress-based treatments, and a clinical trial to test the efficacy of metformin and fasting-mimicking diet on KL NSCLC is currently ongoing in our Institute. Besides inactivating mutations, LKB1 functionality may be impaired by post-translation regulation. Because miR-17 is a potential epigenetic regulator of LKB1,we hypothesized that wild-type LKB1 (LKB1WT) NSCLC with high miR-17 expression may biologically and clinically mirror LKB1 mutated tumors.
Methods: NSCLC cell lines with different combinations of KRAS mutation and LKB1 deletion were selected, together with a panel of PDXs with high (LKB1WT/miR-17 high) or low (LKB1WT/miR-17 low) miR-17 expression. Taking advantage of series of NSCLC patients and PDXs, we retrospectively evaluated LKB1 and miR-17 expression levels in tumor tissue specimens. In addition, the TCGA dataset was interrogated for miR-17 expression and potential correlation with lung cancer clinical features.
Results: Direct targeting of miR-17 to LKB1 3’UTR was confirmed by luciferase reporter assay. We found that miR-17 overexpression in LKB1WT cell lines functionally impaired the LKB1/AMPK pathway, and prompted apoptotic response to metformin. Of note, LKB1WT/miR-17 high PDXs tumor cells showed a similar behavior upon metformin treatment. A retrospective analysis in patients with NSCLC revealed an inverse correlation between miR-17 and LKB1 expression, and highlighted a prognostic role of miR-17 expression in LKB1WT patients, further confirmed by TCGA data analysis.
Conclusions: We validated miR-17 as epigenetic regulator of LKB1 expression in NSCLC tumors. We propose a miR-17 expression score potentially exploitable to discriminate LKB1WT NSCLC patients with impaired LKB1 expression and poor outcome, eligible for energy-stress-based treatments.
Citation Format: Cristina Borzi, Monica Ganzinelli, Elisa Caiola, Marika Colombo, Giovanni Centonze, Mattia Boeri, Laura Caleca, Ugo Pastorino, Mirko Marabese, Massimo Milione, Massimo Broggini, Marina C. Garassino, Gabriella Sozzi, Massimo Moro. LKB1 down-modulation by miR-17 biologically and clinically mirrors LKB1-mutated NSCLC [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 1539.