bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4943: SP-1-39 as a novel tubulin inhibitor overcomes taxane resistance in castration-resistant prostate cancer model
Authors: Wang Rui , Hartman Kelli L. , Pochampally Satyanarayana , Miller Duane D. , Li Wei
Published: April 2023

Colchicine binding site inhibitors have proven to have potent anti-cancer efficacy in many cancer types. Inhibition of tubulin polymerization, a popular mechanism of action for anti-cancer activities, will be activated once the inhibitor interacts with the colchicine binding site. We have previously developed and reported a potent tubulin inhibitor (SB-216). One of its derivatives, the compound SP-1-39, a pyrimidine dihydroquinoxalinone derivative, has been recently designed to further improve the potency and therapeutic properties. Here, we examined the impact of SP-1-39 on preclinical prostate cancer models in vitro and in vivo. EBI competition assay confirmed that SP-1-39 binds to colchicine-binding site and inhibits the formation of EBI:β-tubulin adduct. The anti-proliferation abilities of SP-1-39 was tested against melanoma, breast cancer, pancreatic cancer, prostate cancer, and paclitaxel-resistant prostate cancer cell lines by MTS assay, and defined IC50 values of 0.2-4 nmol/L. Other in vitro results showed SP-1-39 disrupted microtubule network, induced cell cycle arrest at G2/M phase, and caused apoptosis in paclitaxel-resistant human prostate cancer cells (PC-3/TxR). For in vivo study, 2.5mg/kg SP-1-39 significantly attenuated tumor growth in PC-3/TxR xenograft mouse model, inhibited angiogenesis, and overcame taxane resistance. Our findings demonstrate the preclinical therapeutic efficacy and safety of SP-1-39, and provide support for further exploration of novel tubulin inhibitors as anti-cancer agent for cancer therapy.

Citation Format: Rui Wang, Kelli L. Hartman, Satyanarayana Pochampally, Duane D. Miller, Wei Li. SP-1-39 as a novel tubulin inhibitor overcomes taxane resistance in castration-resistant prostate cancer model. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4943.
Abstract 497: HX301, a first-in-class ARK5i, demonstrates antitumor activity in preclinical HCC models with high ARK5/Myc expression
Authors: Jiao Zhihua , Wang Jingjing , Ke Hang , Zhang Faming , Li Henry
Published: April 2023

Introduction: Hepatocellular carcinoma (HCC) is an aggressive malignance of high mortality (6th most common worldwide) with few treatment options. Current drug treatments, including chemo-/target therapies (e.g., sorafenib), are usually ineffective among advanced HCC and with high toxicity. ARK5, or NUAK1, a novel AMP-activated protein kinase (AMPK) family member 5, is found overexpressed in many malignancies including HCC and usually associated with poor prognosis, as well as drug resistance. For example, doxorubicin, first-line chemotherapy for TACE, and transarterial chemoembolization for advanced HCC. In addition, ARK5 is found to be vitally involved in oncoprotein Myc-driven oncogenesis (metabolic homeostasis/cell survival), particularly in tumors under nutrition/oxygen-deprivations, including HCC. HX301 is a clinical stage first-in-class (FIC) ARK5 inhibitor (ARK5i) and other kinase activities (e.g., CDK4/6, CSF1R, etc.). In this study we evaluate HX301 antitumor activity in HCC over-expressing both ARK5 and c-Myc.

Methods: A panel of subcutaneous HCC patient-derived xenografts (PDXs) were genomically profiled by whole transcriptome sequencing by RNAseq, and several selected models with different expression of ARK5 and c-myc expression were assessed pharmacologically using daily dosing of 100mg/kg HX301. Subcutaneous tumor responses to HX301 were calculated by tumor growth inhibition (TGI).

Results: HCC PDX models LI1035, LI6610 both had high expression of ARK5 and Myc genes, whereas LI6650 had lower expression level of Myc than LI1035 and LI6610. LI6652 had lower expression level of ARK5 than LI1035 and LI6610. The log2 FPKM values of ARK5 and Myc in model of LI1035 was 3.9284 and 4.8177, 3.6629 and 5.3658 for LI6610, 3.1228 and -0.0556 for LI6650, -0.3538 and 6.5785 for LI6652. The TGI for LI1035 and LI6610 was 64% (P = 0.0293) and 62% (P = 0.0257) respectively whereas in comparison a smaller TGI of 44% (P = 0.034) was observed in LI6650. In the model of LI6652, TGI for HX301 was 58%, but a statistically significant difference was not observed when comparing the treatment group with the vehicle group (P = 0.138).

Conclusions: Our preliminary results demonstrate that HX301 had strong antitumor activity in HCC PDX models expressing both ARK5 and c-Myc. HX301 has the potential to be a first-in-class ARK5i candidate for the treatment of advanced HCC with high expression of c-Myc, warranting further clinical investigation.

Citation Format: Zhihua Jiao, Jingjing Wang, Hang Ke, Faming Zhang, Henry Li. HX301, a first-in-class ARK5i, demonstrates antitumor activity in preclinical HCC models with high ARK5/Myc expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 497.
Abstract 4971: Identification of statins as a potential treatment for ovarian cancer
Authors: Reilly Brendan M. , Miseirvitch Sarah J. , Walker Sarah R.
Published: April 2023

Late-stage diagnoses make ovarian cancer extremely hard to treat. This leads to ovarian cancer accounting for 5% of female cancer deaths and 2.5% of female cancer incidence. Since there are few options for early detection of ovarian cancer, targeted therapies could lead to better outcomes. One target that has been implicated in ovarian cancer, is the transcription factor Signal Transducer and Activator of Transcription 3 (STAT3). STAT3 function is associated with tumor growth, metastasis, drug resistance, angiogenesis, and resistance to apoptosis. These many STAT3 controlled, cancer-associated cellular functions, make it an ideal and versatile target for cancer therapy. Using the Broad institute’s online C.L.U.E. tool and a STAT3 gene signature, we identified statin drugs as potential inhibitors of STAT3 activity. To assess the ability of statins to inhibit STAT3, we treated ovarian cancer spheroids with statins and analyzed STAT3 activity. We have found that statins do not induce a change in the phosphorylation of STAT3 on either tyrosine 705 or serine 727 residues, the two major sites of phosphorylation on STAT3. However, there are other poorly understood post-translational modifications of STAT3, that have previously shown effects on STAT3 function, that may be involved. Importantly, we have observed that statin treatment reduces the viability of Ovcar8 and Heya8 ovarian cancer cell spheroids. We also found that statin treatment induced apoptosis of ovarian spheroids by measuring Annexin V staining. A major problem for ovarian cancer patients is metastasis. Our preliminary evidence suggests that statins reduce the ability of ovarian cancer spheroids to clear a mesothelial monolayer of cells, an early step in ovarian cancer metastasis. There are several membrane-associated signaling proteins, including RAF and RAS, that affect STAT3 activity. Both Ovcar8 and Heya8 spheroids showed a decrease in cell viability with statin treatment, which is partially rescued by geranylgeranyl pyrophosphate (GGPP), a downstream metabolite in the mevalonate pathway. The partial recovery by GGPP indicates a mechanism involving the prenylation of membrane associated proteins. This data shows statins may provide effective treatments for ovarian cancer and defining the mechanisms behind the effects of statins may lead to better therapies and outcomes for ovarian cancer patients

Citation Format: Brendan M. Reilly, Sarah J. Miseirvitch, Sarah R. Walker. Identification of statins as a potential treatment for ovarian cancer . [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4971.
Abstract 4988: A tailored platform enables BRAF-targeted drug discovery and precision medicine
Authors: Qi Hui , Wang Fuyang , Han Bingrui , Wang Xiaomin , Qiang Xiangnan , Zhang Zhixiang , Gu Qingyang
Published: April 2023

Mutant BRAF, one of the most frequently mutated serine/threonine kinase, drives tumorigenesis via activating MAPK signaling across various tumor types. Expanded genomic and mechanistic studies over the past two decades have revealed the heterogeneity regarding BRAF mutation status and characterized a classification system for BRAF mutations based on their mode of action. Class I (V600 mutants) and class II (K601 mutants, G469A/V/R, etc) BRAF mutants function as RAS-independent active monomers or dimers to amplify MAPK signaling, whereas class III (G466 mutants, D594 mutants, G469E, etc) mutants, which are kinase impaired or dead, promote MAPK signaling via enhanced RAS binding and subsequent CRAF activation. To date, combination therapies of BRAF and MEK inhibitors have been approved for treatment of patients harboring class I BRAF mutations, while viable therapeutic options for those with class II and III BRAF mutations are still ambiguous. Therefore, developing new drugs and personalized therapeutic strategies directing different classes of BRAF mutations, especially class II and III subtypes, have become vital in the war against BRAF-mutant tumors. To enable BRAF-targeted drug discovery and precision medicine, we developed a tailored platform based on the classification of BRAF mutations, which integrates whole exome sequencing (WES) for identification of mutant BRAF subtypes with in vivo efficacy evaluation in patient-derived tumor xenograft (PDX) models. Our platform covers all three classes of BRAF mutants, such as V600E/G469A/D594N/G469E. Moreover, this platform faithfully recapitulate the responses of multiple targeted therapies, such as BRAF, MEK and EGFR inhibitors, reported for treating BRAF-mutant tumors in preclinical and clinical studies, highlighting the potential translation values. Taken together, the platform reported in this study empowers the discovery of novel BRAF inhibitors that can be translated into clinical trials and provides personalized therapeutic options for patients who have poorly responded to standard clinical therapies.

Citation Format: Hui Qi, Fuyang Wang, Bingrui Han, Xiaomin Wang, Xiangnan Qiang, Zhixiang Zhang, Qingyang Gu. A tailored platform enables BRAF-targeted drug discovery and precision medicine. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4988.
Abstract 5010: Inhibition of discoidin domain receptor 1 (DDR1) as a new therapeutic strategy for osteosarcoma
Authors: Wang Jinglu , Walker Robert , Hornicek Francis , Duan Zhenfeng
Published: April 2023

Osteosarcoma is the most common type of bone cancer. Current management for osteosarcoma includes neoadjuvant chemotherapy and surgery. Unfortunately, some patients eventually develop recurrent or metastatic diseases and treatment options are extremely limited. Discoidin domain receptor 1 (DDR1) is a unique collagen-activated tyrosine kinase that participates in various human diseases, including cancer. DDR1 promotes the adhesion, proliferation, differentiation, migration, and metastasis of cancer cells. However, the expression and function of DDR1 remain unknown in osteosarcoma. The purpose of this study is to assess the expression, clinical prognostic relationship, and functional roles of DDR1 in osteosarcoma. The correlation between DDR1 expression in tumor tissues and clinicopathological features and prognosis was assessed via immunohistochemical staining of a unique tissue microarray (TMA) constructed from osteosarcoma specimens. Furthermore, DDR1 expression in osteosarcoma cell lines was determined by Western blot. DDR1-specific siRNA and a highly selective DDR1 inhibitor, 7rh, were applied to determine the impact of DDR1 expression on osteosarcoma cell growth and proliferation. In addition, the effect of DDR1 inhibition on clonogenicity was evaluated using a clonogenic assay, and a 3D cell culture model was used to mimic DDR1 effects in an in vivo environment. The results demonstrate that higher DDR1 expression significantly correlates with recurrence, metastasis, and shorter overall survival in osteosarcoma patients. The expression of DDR1 is also inversely correlated to the response to neoadjuvant chemotherapy. Therapeutically, DDR1 knockdown with siRNA or selective inhibition with 7rh decreases the proliferation and growth of osteosarcoma cells. In conclusion, our study supports DDR1 expression as an independent predictor of poor prognosis and a promising therapeutic target for osteosarcoma.

Citation Format: Jinglu Wang, Robert Walker, Francis Hornicek, Zhenfeng Duan. Inhibition of discoidin domain receptor 1 (DDR1) as a new therapeutic strategy for osteosarcoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5010.
Abstract 5016: IL-6 influences PIM1 expression in renal cell carcinoma
Authors: Meza Kimberly S. , Holder Sheldon L.
Published: April 2023

Renal cell carcinoma (RCC) is the most common kidney neoplasm, accounting for over 430,000 new cases worldwide and 179,000 deaths annually. The overexpression of the proviral integration site for moloney murine leukemia virus 1 (PIM1) kinase is associated with poor clinical outcomes in patients with RCC. PIM1 is a constitutively active effector serine/threonine kinase with roles in tumor progression including cell proliferation, apoptosis, invasion, and migration. Yet, the mechanisms underlying PIM1 expression and its function in RCC are not fully delineated. IL-6 is a pleiotropic cytokine involved in the activation of the JAK/STAT signaling cascade. High serum IL-6 levels are implicated in the poor prognosis of RCC patients and are hypothesized to contribute to RCC invasion and metastasis. PIM1 is shown to be transcriptionally regulated downstream of JAK/STAT signaling and an IL-6/STAT3/PIM1 axis exists in pancreatic cancer. We thus hypothesize that this pathway also regulates expression of PIM1 in RCC. Here, we explore the levels of PIM1 in RCC and identify potential signaling pathways influencing PIM1 expression. Our results show five RCC cell lines, 769-P, 786-O, ACHN, CAKI-1, and RCC-4 cells overexpress PIM1 relative to normal renal proximal tubule epithelial cells. In RCC cell lines, IL-6 secretion correlates with PIM1 protein levels. Treatment with ruxolitinib, a JAK1/2 inhibitor, leads to a dose and concentration dependent decrease in PIM1 levels. We then tested whether incubation with an IL-6 neutralizing antibody is sufficient to regulate PIM1 protein levels. Indeed, use of an IL-6 antibody resulted in decreased pJAK2 protein and PIM1 protein. Our initial studies suggest that differential expression of PIM1 among RCC cell lines may be linked to autocrine IL-6 signaling. Interestingly, 769-P cells demonstrate increased PIM1 levels but do not secrete IL-6 and neither ruxolitinib treatment nor incubation with an IL-6 neutralizing antibody appear to affect PIM1 levels. Therefore, an IL-6/JAK-independent pathway resulting in increased PIM1 protein levels likely exists in 769-P cells. Further investigation is required to elucidate the contexts of PIM1 regulatory pathways in order to develop novel targeted anti-cancer strategies in RCC.

Citation Format: Kimberly S. Meza, Sheldon L. Holder. IL-6 influences PIM1 expression in renal cell carcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5016.
Abstract 5024: Role of protein kinase C ζ and ι inhibitors on ovarian cancer cell lines in combination with cisplatin
Authors: Marzan Mahfuza , Oishee Nuzhat Nowshin , Khalid Khandker Mohammad , Acevedo-Duncan Mildred
Published: April 2023

Ovarian cancer causes more death than any other cancers of the female reproductive system. Current treatment strategies are surgical removal of cancerous parts and chemotherapy with platinum drugs (e.g. cisplatin, carboplatin) or taxols. However, recurrence of cancer with drug resistance is frequent. Previously two inhibitors; ICA-1S (5-amino-1-((1R,2S,3S,4R)-2,3-dihydroxy-4-methylcyclopentyl)-1H-imidazole-4-carboxamide and ζ-stat (8-hydroxy-1,3,6- naphthalenetrisulfonic acid) specific for two atypical protein kinases, PKC-ι and PKC-ζ respectively have been reported. These inhibitors have an anticancer effect in different cancers, including clear-cell ovarian cancer. Our aim was to find if cisplatin has any synergistic effect with ICA-1S and ζ-stat on ovarian cancer cell proliferation, migration, and apoptosis. Ovarian cancer cell line ES-2, which has mutation in p53 gene was used in this study. After 72 hours of treatment with ICA-1S (10 µM) and ζ-stat (10 µM), proliferation of ES-2 cell line was inhibited by 42.5% and 23.5% respectively compared to control. When combined with cisplatin (0.5 µM), the inhibition of cell proliferation increased to 67% for ζ-stat and 65.8% for ICA-1S (N=3 trials) which is synergistic. Wound healing assay with ES-2 cells showed that ICA-1S and cisplatin inhibited the migration of ES-2 cells separately as well as in combination. SDS-PAGE and subsequent western blotting showed that ICA-1S monotherapy and combination with cisplatin reduced the expression mutant p53, PI3K, AKT, Bcl2, and phopho-BAD. IP with PKC ζ beads showed the association of PKC ζ with PKC-ι and p53 in ES-2 cell line. As mutation in p53 is quite frequent in ovarian cancer with gain of function, ICA-1S may have an advantageous role in inhibiting mutated p53 regulated pathway. Inhibition of ES-2 cell line with ICA-1S and ζ-stat also suggested that PKC-ι and PKC ζ play important roles in ovarian cancer and may augment traditional chemotherapy. Further study on the pathway affected by aPKC inhibitors combined with cisplatin would be investigated through WST, western blotting and immunoprecipitation assay.

Citation Format: Mahfuza Marzan, Nuzhat Nowshin Oishee, Khandker Mohammad Khalid, Mildred Acevedo-Duncan. Role of protein kinase C ζ and ι inhibitors on ovarian cancer cell lines in combination with cisplatin. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5024.
Abstract 5025: Reduced level of protein kinase C iota renders human glioblastoma less invasive and induces apoptosis via modulating Tak1/NF-κB pathway
Authors: Khalid Khandker Mohammad , Ratnayake Wishrawana S. , Dey Avijit , Oishee Nuzhat N. , Marzan Mahfuza , Acevedo-Duncan Mildred
Published: April 2023

Glioblastoma (GBM) is characterized by poor therapeutic response and overall survival. It is the most aggressive form of primary brain tumor with a tendency to invade surrounding healthy brain tissues, rendering them largely incurable. In this study, small-interference RNA was used to knock down the expression of protein kinase C PKC-ι. The reduced PKC-ι expression impaired the phosphorylation of LIM kinase 1/2 (LIMK), which is a critical step in cofilin recycling and actin polymerization. Additionally, there was a down-regulation of matrix metalloprotease-9 expression in LN-229 and U87G cells, which coincided with decreased invasion. Therefore, PKC-ι regulates both cytoskeleton rearrangement and cell adhesion, which contributed to cell migration. Silencing of PKC-ι also dampened Transforming growth factor-β (TGF-β)-activated kinase 1 (Tak1) level. TAK1 is an essential component in genotoxic stresses-induced NF-κB-activation and mitogen-activated protein kinase (MAPK)-pathways in GBM. TAK1, when activated, forms a complex with TAB1-3 (Tak1 binding proteins). Our data reveal, reduced Tak1 level after silencing PKC-ι interferes with complex formation and reduces NF-κB-activation. Diminished PKC-ι level also reduces activation of Tak1/JNK axis. This deactivation exerts an anti-oncogenic effect on glioblastoma via suppression of Akt1, c-Myc, and STAT3. This implies PKC-ι may have a crucial role in the activation of Tak1. Reduced migration and invasion in glioblastoma cells upon inhibition of PKC-ι was further confirmed by Scratch assay and Boyden assay. These results indicate that PKC-ι is involved in the control of glioblastoma cell migration and invasion. PKC-ι is a central component of multiple converging and bifurcating pathways and is a potential therapeutic target against GBM survival and infiltration.

Citation Format: Khandker Mohammad Khalid, Wishrawana S. Ratnayake, Avijit Dey, Nuzhat N. Oishee, Mahfuza Marzan, Mildred Acevedo-Duncan. Reduced level of protein kinase C iota renders human glioblastoma less invasive and induces apoptosis via modulating Tak1/NF-κB pathway. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5025.
Abstract 5029: Determining the biological function of TNK1
Authors: Kohler Emmalee , Lopez-Palacios Tania , Chan Tsz-Yin , Egbert Christina , Truman Jacob , Ashworth Spencer , Vaughan Alec , Andersen Joshua , Madhusanka D.
Published: April 2023

Thirty-eight-negative kinase 1 (TNK1) is a poorly characterized member of the ACK family of non-receptor tyrosine kinases, which we recently identified as a driver of cell survival in a subset of primary hematological malignancies. However, the biological function of TNK1 is not well understood. We also found that TNK1 is unusual among kinases for the presence of a functional ubiquitin association (UBA) domain on its C-terminus. We discovered that the TNK1 UBA domain binds to poly-ubiquitin with high affinity and has no apparent preference for ubiquitin chain length or linkage type. Interestingly, the UBA domain is important for TNK1 function, given that deletion of the UBA domain (TNK1 ΔUBA) alters its localization and phospho-substrate network, while also weakening the oncogenic activity of TNK1 in cell transformation assays. Based on these data, we hypothesized that the UBA domain tethers TNK1 to its substrates. To test this hypothesis, we performed quantitative phospho-tyrosine proteomics using murine pro-B cells transformed with either TNK1 full length or TNK1 ΔUBA and identified TANK-binding kinase 1 (TBK1) as a putative UBA-dependent TNK1 substrate. TBK1 is a serine/threonine kinase involved in the regulation of inflammation, autophagy, and NF-ĸB signaling. During the selective autophagic degradation of misfolded proteins (aggrephagy), TBK1 phosphorylates p62 at S403 to increase its affinity to ubiquitin, and thereby increases p62-mediated recruitment of misfolded proteins into the condensate. Unchecked growth of ubiquitin condensates can overwhelm the size capacity of autophagosomes, potentially causing misfolded proteins to become proteotoxic aggregates. Our preliminary data suggest a model in which active TNK1 accumulates at ubiquitin condensates to phosphorylate and inhibit TBK1. Based on these data, we propose that TNK1 acts as a kinase sensor of poly-ubiquitin to control the TBK1-mediated growth of ubiquitin condensates.

Citation Format: Emmalee Kohler, Tania Lopez-Palacios, Tsz-Yin Chan, Christina Egbert, Jacob Truman, Spencer Ashworth, Alec Vaughan, Joshua Andersen, D. Madhusanka. Determining the biological function of TNK1. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5029.
Abstract 504: BPI-472372: a potent and orally bioavailable small molecule inhibitor of CD73 for cancer immunotherapy
Authors: Han Han , Yang Xiaofeng , Zhao Ying , Wang Jin , Yang Xiang , Ju Xuepeng , Zhao Jiayu , Zou Zhengyao , Chen Haibo , Liu Xiaoyun , Guo Jing , Yang Cheng , Lan Hong , Wu Hao , Ding Lieming , Wang Jiabing
Published: April 2023

CD73, also known as ecto-5'-nucleotidase, plays a major role in converting extracellular adenosine monophosphate (AMP) to immunosuppressive adenosine. It is frequently overexpressed across a variety of cancers. High adenosine level in the tumor microenvironment, predominantly signaling through the A2a/A2b receptors, suppresses innate and adaptive immune responses and mediates tumor immune evasion. CD73 overexpression is correlated with poor prognosis in several tumor types. Inhibition of CD73 to reduce adenosine production is a promising therapeutic approach for the treatment of cancer. Both monoclonal antibodies and small molecule inhibitors are being explored to target CD73. Small molecule CD73 inhibitor with good balance of activity and ADME properties are rare. Here we present BPI-472372, a potent, selective, and orally bioavailable small molecule CD73 inhibitor. It strongly inhibits both soluble and cell-bound CD73, with no off-target activity on other related nucleotidases (NTPDases 1/2/3/5), nor on a large panel of enzymes, receptors, and ion channels. BPI-472372 reversed AMP-induced CD4+ T cell suppression in a dose-dependent manner. In vivo, BPI-472372 exhibited anti-tumor effect in MC38 syngeneic mouse model with no visible adverse effect. Moreover, enhanced tumor growth inhibition activity was observed when BPI-472372 was combined with durvalumab (anti-PD-L1) in humanized PD-L1 syngeneic MC38 model. BPI-472372 exhibited desirable drug-like properties including high permeability, low hepatocytes clearance, and adequate oral exposure across multiple pre-clinical species. GLP toxicity study indicated that BPI-472372 was well tolerated at high dose following 4 weeks repeated administration in both mouse and dog. Taken together, BPI-472372 is a potent and orally bioavailable small molecule CD73 inhibitor with single agent anti-tumor efficacy, favorable ADME properties, and a wide therapeutic index.

Citation Format: Han Han, Xiaofeng Yang, Ying Zhao, Jin Wang, Xiang Yang, Xuepeng Ju, Jiayu Zhao, Zhengyao Zou, Haibo Chen, Xiaoyun Liu, Jing Guo, Cheng Yang, Hong Lan, Hao Wu, Lieming Ding, Jiabing Wang. BPI-472372: a potent and orally bioavailable small molecule inhibitor of CD73 for cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 504.
Abstract 5044: Antitumor activity comparison of two somatostatin receptor ligands radiolabeled with Lutetium-177 (SSO110 and DOTA-TATE) alone or combined with chemotherapy in mice bearing AR42J SST2-positive tumors
Authors: Raguin Olivier , Krüger Marcel , Provent Peggy , Cay Funda , Marie dit chatel Elodie , Lux Marie , Lezmi Stéphane , Meyer-Losic Florence , Plas Pascale , Pais Ben , Berthet Cyril
Published: April 2023

Only a limited number of studies have compared the therapeutic effects of repetitive cycles of radiolabeled somatostatin (SST) analogues or assessed potential synergy of these analogues with chemotherapy agents.

Hence, a comparison was conducted in an in vivo AR42J tumor model with an SST2 antagonist, [177Lu]Lu-satoreotide tetraxetan ([177Lu]LuSSO110), and a SST2 agonist, [177Lu]Lu-DOTA-TATE. The efficacy of treatment combining [177Lu]Lu-satoreotide tetraxetan with capecitabine plus temozolomide was also assessed.

Swiss Nude mice were xenografted with AR42J tumor cells. For the evaluation of the tumor response to radiation therapy, animals received one weekly dose of [177Lu]LuSSO110 or [177Lu]Lu-DOTA-TATE for four consecutive weeks. For combined treatments, animals received one weekly dose of [177Lu]LuSSO110 at 20 MBq for four consecutive weeks in association with daily doses of capecitabine and temozolomide (CAPTEM).

Weekly treatment for four consecutive weeks with [177Lu]LuSSO110 at 15 MBq revealed a significantly reduced tumor growth, with 68 days to reach a tumor volume of 850 mm3, compared to [177Lu]Lu-DOTA-TATE at 15 MBq or 30 MBq, with, respectively, 43 days and 48 days. This was associated with a 3.5 fold higher tumor uptake of [177Lu]LuSSO110 (15 MBq) compared to [177Lu]Lu-DOTA-TATE, with no or mild effects on body weight, hematological toxicity, or renal toxicity.

In AR42J tumor-bearing mice treated once a week for four consecutive weeks, [177Lu]LuSSO110 (15 MBq) associated with CAPTEM regimen did

not significantly increase the median time to reach a tumor volume of 1000 mm3 as compared to treatment with [177Lu]Lu-satoreotide alone: 50.7 vs 42.2 days, respectively. The association of the two treatments only led to mild weight losses.

Repeated administrations of [177Lu]LuSSO110 were able to potentiate peptide receptor radionuclide therapy with a higher tumor uptake and longer median survival compared to [177Lu]Lu-DOTA-TATE. The The combination of [177Lu]Lu-satoreotide with capecitabine and temozolomide did not show any synergy, but no antagonism was observed either.

Citation Format: Olivier Raguin, Marcel Krüger, Peggy Provent, Funda Cay, Elodie Marie dit chatel, Marie Lux, Stéphane Lezmi, Florence Meyer-Losic, Pascale Plas, Ben Pais, Cyril Berthet. Antitumor activity comparison of two somatostatin receptor ligands radiolabeled with Lutetium-177 (SSO110 and DOTA-TATE) alone or combined with chemotherapy in mice bearing AR42J SST2-positive tumors. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5044.
Abstract 5050: Case report: A 17-year-old patient developed glioblastoma secondary to intracranial germ cell tumor and was stabilized with chemoradiotherapy combined with Tumor Treating Fields
Authors: Li Shaoqun , Lai Mingyao , Li Hainan , Li Juan , Zhou Jiangfen , Hu Qingjun , Ye Minting , Ai Ruyu , Zhu Junqiao , Huang Lijun , Cai Linbo
Published: April 2023

Background: Germ Cell Tumor (GCT) is a rare intracranial tumor occurring in children and young adults. Some patients with GCT are curable with radiotherapy and chemotherapy. Due to long-term survival, the tumor secondary to radiotherapy is of concern. The treatment of the secondary tumor is less elaborated and worth exploring.

Case Presentation: Here we report a patient with GCT who developed radiotherapy-induced glioblastoma. He was diagnosed as pineal gland GCT at the age of 12. Afterwards, he underwent a set of treatments, including chemotherapy, radiotherapy, and surgery. Unfortunately, after 5 years of tumor-free survival, he developed an intracranial mass involved the right thalamus and brainstem, around pineal region. The GCT recurrence was firstly considered, however, the failure of 7 cycles of chemotherapy drew attention. Then brain biopsy underwent by ROSA robot showed high-grade glioma. Next Generation Sequencing showed IDH-wildtype, MGMT methylation, CDKN2A/B homozygous deletion, EGFR amplification, the +7/−10 signature, which supported the diagnosis of glioblastoma. Resection operation is not applicable for this patient as the involvement of thalamus and brainstem. Considering the difficulty of treatment and poor prognosis of glioblastoma, re-radiotherapy is a feasible choice. Chemoradiotherapy with Tumor Treating Fields (TTFields) is a innovative try for secondary glioblastoma in a 17-year-old patient. After the combination therapy, the intracranial mass went regression and the patient has lived for more than 1 years.

Conclusions: For the patients with brain tumor who anticipate long-term survival, the secondary tumor after radiotherapy is of concern. Secondary Glioblastoma is rare and difficult to treat. Chemoradiotherapy with TTFields is a feasible and safe treatment option for some patients, but we need more evidence to support.

Citation Format: Shaoqun Li, Mingyao Lai, Hainan Li, Juan Li, Jiangfen Zhou, Qingjun Hu, Minting Ye, Ruyu Ai, Junqiao Zhu, Lijun Huang, Linbo Cai. Case report: A 17-year-old patient developed glioblastoma secondary to intracranial germ cell tumor and was stabilized with chemoradiotherapy combined with Tumor Treating Fields. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5050.
Abstract 5068: Nintedanib enhances antitumor effects of anti-PD-1 therapies through inhibition of immunosuppressive cells in tumor microenvironment
Authors: Suzuki Ryo , Watanabe Satoshi , Shono Kunihiro , Masuda Takaaki , Sekiya Tomoki , Goto Yuka , Fujisaki Toshiya , Arita Masashi , Ohtsubo Aya , Shoji Satoshi , Tanaka Tomohiro , Nozaki Koichiro , Kondo Rie , Saida Yu , Hokari Satoshi , Ohashi Riuko , Shima Kenjiro , Kimura Yosuke , Aoki Nobumasa , Ohshima Yasuyoshi , Koya Toshiyuki , Kikuchi Toshiaki
Published: April 2023

Background: Although programmed cell death-1 (PD-1) inhibitors have achieved promising and durable responses in patients with several types of cancer, many patients show intrinsic resistance to PD-1 inhibitors. Extensive studies have demonstrated that immunosuppressive cells are induced in tumor microenvironment and inhibit antitumor effects of PD-1 inhibitors. The aim of current study is to investigate whether nintedanib, which targets multi-tyrosine kinase including vascular endothelial growth factor, fibroblast growth factor, and platelet-derived growth factor, reduced immunosuppressive cells in tumor microenvironment and augments antitumor effects of PD-1 inhibitors.

Method: Mice were inoculated subcutaneously with CT26 murine colon carcinoma or MC38 murine colon carcinoma and were treated with nintedanib (50 mg/kg), αPD-1mAbs (10 mg/kg) or nintedanib plus αPD-1mAbs. The tumor size was measured in 2 perpendicular dimensions 3 times per week. Types of cells infiltrating into tumors and immune status of tumor-draining lymph nodes were assessed using flow cytometry and immunohistochemistry (IHC).

Results: RNA sequencing data revealed that nintedanib decreased gene expression related to endothelial mesenchymal transition, angiogenesis and coagulation. Flow cytometry showed that nintedanib significantly decreased the percentage of myeloid-derived suppressor cells and cancer-associated fibroblast in tumor tissues. Both of flow cytometry and IHC analysis showed that nintedanib significantly increased IFN-ϒ+CD4+ and CD8+ T cells infiltrating in tumors. In addition, nintedanib plus αPD-1mAbs significantly retarded tumor progression.

Conclusion: Nintedanib decreased immunosuppressive cells, increased effector T cells, and enhanced anti-tumor effects of αPD-1mAbs. Based on these findings, there are possibility that nintedanib improves clinical outcomes of cancer patients treated with PD-1 inhibitors.

Citation Format: Ryo Suzuki, Satoshi Watanabe, Kunihiro Shono, Takaaki Masuda, Tomoki Sekiya, Yuka Goto, Toshiya Fujisaki, Masashi Arita, Aya Ohtsubo, Satoshi Shoji, Tomohiro Tanaka, Koichiro Nozaki, Rie Kondo, Yu Saida, Satoshi Hokari, Riuko Ohashi, Kenjiro Shima, Yosuke Kimura, Nobumasa Aoki, Yasuyoshi Ohshima, Toshiyuki Koya, Toshiaki Kikuchi. Nintedanib enhances antitumor effects of anti-PD-1 therapies through inhibition of immunosuppressive cells in tumor microenvironment. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5068.
Abstract 5184: Anti-HVEM mAb therapy improves antitumoral immunity both in vitro and in vivo, in a novel transgenic mouse model expressing human HVEM and BTLA molecules challenged with HVEM expressing tumors
Authors: GORVEL Laurent , Demerle Clemence , Mello Marielle , Pastor Sonia , Degos Clara , Zarubica Ana , Angelis Fabien , Fiore Frederic , Nunes Jacques , Malissen Bernard , Greillier Laurent , Guittard Geoffrey , Luche Herve , Barlesi Fabrice , Olive Daniel
Published: April 2023

TNFRF-14/HVEM is the ligand for BTLA and CD160 negative immune co-signaling molecules as well as viral proteins. Its expression is dysregulated with an overexpression in tumors and a connection with tumors of adverse prognosis. We developed C57BL/6 mouse models co-expressing human huBTLA and huHVEM as well as antagonistic monoclonal antibodies (mAbs) that completely prevent the interactions of HVEM with its ligands. Here, we show that the anti-HVEM18-10 mAb increases primary human αβ-T cells activity alone (CIS-activity) or in the presence of HVEM-expressing lung or colorectal cancer cells in vitro (TRANS-activity). Anti-HVEM18-10 synergizes with anti-PD-L1 mAb to activate T cells in the presence of PDL-1 positive tumors, but is sufficient to trigger T cell activation in the presence of PD-L1 negative cells. In order to better understand HVEM18-10 effect in vivo and especially disentangle its CIS and TRANS effects, we developed a knock-in (KI) mouse model expressing human BTLA (huBTLA+/+) and a KI mouse model expressing both human BTLA and human HVEM (huBTLA+/+/huHVEM+/+ (DKI)). In vivo pre-clinical experiments performed in both mouse models showed that HVEM18-10 treatment was efficient to decrease human HVEM+ tumor growth. In the DKI model, anti-HVEM 18-10 treatment induces a decrease of exhausted CD8+ T cells and regulatory T cells and an increase of Effector memory CD4+ T cells within the tumor. Interestingly, mice which completely rejected tumors (± 20%) did not develop tumors upon re-challenge in both settings, therefore showing a marked T cell-memory phenotype effect. Altogether, our preclinical models validate anti-HVEM18-10 as a promising therapeutic antibody to use in clinics as a monotherapy or in combination with existing immunotherapies (anti-PD1/anti-PDL-1/anti-CTLA-4).

Citation Format: Laurent GORVEL, Clemence Demerle, Marielle Mello, Sonia Pastor, Clara Degos, Ana Zarubica, Fabien Angelis, Frederic Fiore, Jacques Nunes, Bernard Malissen, Laurent Greillier, Geoffrey Guittard, Herve Luche, Fabrice Barlesi, Daniel Olive. Anti-HVEM mAb therapy improves antitumoral immunity both in vitro and in vivo, in a novel transgenic mouse model expressing human HVEM and BTLA molecules challenged with HVEM expressing tumors. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5184.
Abstract 5200: Novel Immuno-Oncology drugs evaluation by humanised immune cells and cancer co-inoculated models
Authors: Xie Bin , Hou Xin , Chen Hanglu , Yang Pengfei , Zhou Yanbin , Wen Danyi
Published: April 2023

Currently more and more immunotherapeutic drugs and engineered cells have been developed to use human immune system against cancer. While humanized peripheral blood mononuclear cell reconstitution in immune deficient mice is a forward-straight model for evaluating therapeutic antibodies, this conventional model has several drawbacks to hinder its widespread use, including the graft-versus-host-disease happened after one month of reconstitution, insufficient immune cell infiltration from reconstituted circulatory system and hardly retention of functional innate immune cells, such as macrophages and nature killer cells. To overcome this, LIDE has developed a specific human immune cell and cancer cell co-inoculation model. Cancer-priming PBMC and/or its derivates were well mixed with the fresh cancer cells in MatriGel, co-transferring into NCG mice to form a relatively “hot tumor” tissue for immunotherapy, including drugs targeting T cells, dendritic cells and macrophages. Additionally, we also take advantage of human IL15 transgenic mice to study the function of ex vivo expanded NK cells. This novel method has successfully helped evaluate biological function of immune checkpoint blockers and immune agonists in multiple cancers, such as melanoma, breast cancer, lung cancer, hepatocellular carcinoma and ovarian cancer.

Citation Format: Bin Xie, Xin Hou, Hanglu Chen, Pengfei Yang, Yanbin Zhou, Danyi Wen. Novel Immuno-Oncology drugs evaluation by humanised immune cells and cancer co-inoculated models. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5200.
Abstract 5219: Telomere length distribution, metabolic trait association, and genome-wide association study among Singaporean cohorts
Authors: Nguyen Trang , Chan Penny , Lim Ives , Kennedy Brian , Karnani Neerja , Dorajoo Rajkumar , Ngeow Joanne
Published: April 2023

Leukocyte telomere length (LTL) is known as a heritable marker of cellular aging and is a risk factor for several chronic diseases. LTL distribution and association studies are essential in providing insights into telomere homeostasis, its relationship with different metabolic traits, and age-related conditions. Such studies have been underperformed in Asian population groups. Here we estimated LTL using whole-genome sequencing data in 8,045 Singaporean samples across three major ethnic groups - Chinese, Indian, and Malay divided into six cohorts: GUSTO, HELIOS, MEC, PRISM, SEED, and TTSH. LTLs were measured using TelSeq, with normalized LTL as phenotype in subsequent analyses. We demonstrated that average LTL was robustly longer in the childhood cohort (GUSTO) compared to the adult cohorts (P<1.19 × 10−195). We observed ethnicity differences in LTL where adult Singaporean Chinese samples had the longest LTL (5.08kb) as compared to Malay (4.87kb) and Indian (4.65kb) samples in our datasets (P<4.98 × 10−12). Our genetic association analyses replicated multiple variants previously reported to be associated with LTL (binomial P<0.00001) in Asian population groups, providing added confidence in the methodologies used. At the same time, we identified a novel East-Asian-specific novel variant beyond genome-wide association levels (meta P=2.05 × 10−08) at the COL28A1/MIOS gene loci to be associated with LTL in our study. Individual analysis of the GUSTO childhood dataset highlighted a second novel genome-wide hit at RAD17 gene locus to be associated with LTL in our study and indicated that the previously reported variant at the TINF2 locus may have significantly opposing effects (compared to adults) during early developmental stages. Gene-level burden analysis for rare variants (MAF <5%) in adult Chinese cohorts revealed potential cancer association with RET gene (SKAT, P=5.22 × 10−03) and MLH1 gene (SKAT, P=0.037), as well as telomere biology condition association with RECQL4 gene (CMC, P=0.0399, and VT, P=0.0379). Our findings have broadened the understanding of LTL distribution and the underlying associated genetic characteristics in both childhood and adult Singaporean populations.

Citation Format: Trang Nguyen, Penny Chan, Ives Lim, Brian Kennedy, Neerja Karnani, Rajkumar Dorajoo, Joanne Ngeow. Telomere length distribution, metabolic trait association, and genome-wide association study among Singaporean cohorts. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5219.
Abstract 5238: The functional role of promoter germline variants in breast cancer susceptibility genes
Authors: Arroyo Nelly Arlene , Godoy Lenin J. , Dutil Julie
Published: April 2023

It is estimated that inherited deleterious or pathogenic germline variants in high- to moderate- penetrance breast cancer (BC) susceptibility genes such as BRCA1, BRCA2, STK11, CDH1, ATM, PALB2, and CHEK2 may explain up to 27% of the BC cases. For the remaining cases, BC develops as a result of the complex interaction between environmental and lifestyle risk factors as well as inherited familial predisposition. While low penetrance genetic variants have limited impact on BC risk when taken individually, their combined effect on polygenic risk scores may provide a risk elevated enough to justify clinical actions. Most of the previous work in hereditary breast cancer research has focused on variants located in the coding region of the genes and as a result, there is an abundance of information on the functional interpretation of such variants, while information on regulatory variants remains limited. The goal of this study was to assess the functional impact of germline variants in the promoter region of BC susceptibility genes on gene expression level. Genes evaluated include CDH1, STK11, and bidirectional promoter genes ATM/NPAT and PALB2/DCTN5. A bioinformatics approach was developed to identify and prioritize variants based on conservation level and predicted binding of transcription regulatory proteins. Selected variants will be introduced into pGL3 constructs harboring the promoter of interest using site-directed mutagenesis followed by transfection into HEK293T cells. Dual-glo luciferase expression assays are used to measure levels of promoter activities. Expression levels from promoters containing genetic variants are compared with those from constructs containing the reference sequence. The reference constructs for STK11 and CDH1 containing the genes complete promoters demonstrated functional activity. For bidirectional promoters, forwards and reverse construct were tested. Forward ATM/NPAT and PALB2/DCTN5 constructs showed luciferase expression under the influence of ATM and DCTN5 respectively. Work is on the way to assess promoter activity of the reverse complement sequence of those promoters and determine the impact of 13 candidate variants on the strength of these promoters. At the clinical level, identifying germline variants that contribute to BC risk could help better define BC risk in women with negative hereditary cancer genetic test results.

Citation Format: Nelly Arlene Arroyo, Lenin J. Godoy, Julie Dutil. The functional role of promoter germline variants in breast cancer susceptibility genes. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5238.