bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5253: SMO as a predicted biomarker on immunotherapy and correlated with immune infiltrates in mCRC
Authors: Cai Jinlin , Fan Dandan , Chen Yaoxu , Huang Mengli
Published: June 2022

Background: Colorectal cancer has become a common gastrointestinal tumor. Immune checkpoint inhibitors (ICIs) including pembrolizumab, nivolumab, ipilimumab have shown durable responses and have been approved by FDA. However, ICIs demonstrate antitumor effects only in a fraction of patients, and research exploring the association between gene mutation and clinical benefit is limited. SMO, a gene encodes Smoothened protein, which is an important signal converter in Sonic Hedgehog (SHH) signal pathway. Studies have shown that CTLA-4 expressing CD3+ lymphocytes were observed in atypical and malignant meningioma and tumors harboring SMO mutation, suggested that SMO may be related to immune microenvironment and tumor immunity, but the association between SMO mutation and TMB or survival in metastatic Colorectal Cancer(mCRC) is unknown.

Methods: Genomic and survival data of mCRC patients administrated with ICIs were retrieved from publicly accessible data (Pancancer.Samstein2018.NGS.1661) and the association between SMO mutation overall survival (OS) were analyzed using Kaplan-Meier curves and log-rank tests. The association between SMO mutation and TMB was also analyzed in this public immunotherapy-treated cohort, Wilcoxon test was used for the comparison of TMB. In addition, Genomic, immune cell infiltration data of 149 patients with Rectum Adenocarcinoma (READ) was obtained from The Cancer Genome Atlas (TCGA). The correlation analysis between immune cell infiltration and SMO mutation status was further analyzed by CIBERSORT. Statistical significance was set at p=0.05.

Results: 7.3% (8/109) patients in the clinical cohort harbored SMO mutation. Survival analysis in the public cohort demonstrated that SMO mutation resulted in significantly longer OS (10.5 vs 8 months; HR, 0; p=0.035) in mCRC patients treated with ICIs. Moreover, SMO mutation is associated with higher TMB in public cohort (p<0.0001). Furthermore, the correlation analysis between immune infiltration and SMO mutation status in mCRC which was analysed in TCGA shows that M1 macrophages, CD8 T cells, Gamma Delta T cells increased significantly (p=0.048, p=0.043, p=0.002).

Conclusions: This study shows that SMO mutation may serve as a potential positive biomarker of ICIs in melanoma since it relatively correlated with higher TMB. In addition, the up regulation of M1 macrophages, CD8 T cells, as well as the Gamma Delta T cells may be another potential mechanism for the better efficacy of ICIs in patients with SMO mutation.

Citation Format: Jinlin Cai, Dandan Fan, Yaoxu Chen, Mengli Huang. SMO as a predicted biomarker on immunotherapy and correlated with immune infiltrates in mCRC [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 5253.
Abstract 5278: Cancer WHIRI research: Improving the early cancer pathway for indigenous NZ peoples
Authors: Scott Nina , Ruka Myra , Jones Amy R.
Published: June 2022

Background: Māori, Indigenous peoples of New Zealand (NZ) are twice as likely to die after a diagnosis of cancer compared to non-Māori. Cancer pathways are not designed for Māori health gain and are not pandemic resilient. Māori receive delayed poorer quality treatment and those with comorbidities are undertreated [1]. Existing inequities from time of referral to cancer services through to treatment were exacerbated by the COVID-19 response in Aotearoa NZ. Coordination of care is crucial for Māori patients and whānau (family), but poorly developed along this early part of the cancer pathway. In addition, care quality is not well monitored, and the current pathway is vulnerable to changes created by pandemic conditions.

Aims: This study seeks to co-design, implement and evaluate a holistic cultural and clinical cancer service that is patient and whānau centred; the Whānau Hauora Integrated Response Initiative (WHIRI) programme. This comprehensive, pandemic resilient, racism-free, hauora (wellbeing) enhancing and responsive model of care will be designed for the early part of the secondary care cancer pathway.

Design and Method: The WHIRI programme includes navigation, a holistic whānau/family hauora assessment tool, proactive management by a team of clinicians and a team responsible for making systems changes. WHIRI was launched mid-pandemic (early 2020) for kaumātua (elderly Māori) with long-term conditions and ran for 3 months. During COVID we found that WHIRI had the potential to change hospital systems and improve experiences for patients and whānau. WHIRI ensures the provision of best-practice timely treatment for Māori patients and could make large gains in closing the survival gap between Māori and non-Māori in the short- to medium-term, leading to reductions in Māori cancer deaths. We plan to redesign WHIRI into a cancer programme that functions effectively in all COVID levels using qualitative Kaupapa Māori methodology. Key to this methodology is partnerships with patients, whānau, cancer clinicians, Māori navigators and The Cancer Control Agency New Zealand. We will present our methods and co-design model of cancer care. We will outline the potential to expand the model nationally with reach from primary care all the way through to palliative care. It will also provide a platform for future research to measure the impact of WHIRI on cancer and whānau care. 1. Hill S, Sarfati D, Blakely T, Robson B, Purdie G, Chen J, et al. Survival disparities in Indigenous and non-Indigenous New Zealanders with colon cancer: the role of patient comorbidity, treatment and health service

Citation Format: Nina Scott, Myra Ruka, Amy R. Jones. Cancer WHIRI research: Improving the early cancer pathway for indigenous NZ peoples [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 5278.
Abstract 5286: RNase7-guided anti-ROS1 targeted therapy for hepatocellular carcinoma
Authors: Liu Chunxiao , Zha Zhengyu , Zhou Chenhao , Yu Dihua , Ren Ning , Hung Mien-Chien
Published: June 2022

Oncogenic activation of c-ros oncogene 1 (ROS1) kinase due to gene fusion by chromosomal rearrangements was found in multiple cancers. The anti-ROS1 fusion gene is a successful therapeutic target with a 72% objective response rate in ROS1-rearranged NSCLC patients. However, it has yet to be determined whether wild-type ROS1 plays a role in cancer development or could serve as a therapeutic target as its ligand was unknown. Our study unexpectedly identified that RNase7, a RNase superfamily protein, is specifically pulled down by ROS1 and acts as a ROS1 ligand. In HCC patient-derived xenograft and an orthotopic mouse model of HCC, we found that crizotinib, an FDA-approved ROS1 inhibitor, exhibits potent anti-tumor activity in the mice harboring RNase7-expressing tumors. In addition, clinical data analysis indicated that ROS1 and RNase7 co-expression occurs in about 30% of HCC patients and is highly correlated with poorer survival. The plasma level of RNase7 is positively correlated with phosphorylated ROS1 in HCC patients. Our current report provides a rationale to choose RNase7 as a potential plasma biomarker to stratify HCC patients for anti-ROS1 targeted therapy.

Citation Format: Chunxiao Liu, Zhengyu Zha, Chenhao Zhou, Dihua Yu, Ning Ren, Mien-Chien Hung. RNase7-guided anti-ROS1 targeted therapy for hepatocellular carcinoma [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 5286.
Abstract 5287: Aggregation of HER2 receptors on the tumor cell surface induced by a novel anti-HER2 bispecific antibody led to enhanced tumor cell growth inhibition
Authors: Deng Lan , Zhao Jie , Meng Xiaoqing , Xiao Aotian , Zhu Zhenping , Huang Haomin
Published: June 2022

Trastuzumab, an anti-HER2 monoclonal antibody developed by Roche, is now a standard of care for treating HER2 overexpressing cancers. However, patients treated with trastuzumab generally develop resistance to the drug within a year after initiation of the treatment. Pertuzumab, another anti-HER2 monoclonal antibody developed by Roche, targets the domain 2 of the HER2 excellular domain (ECD) instead of the domain 4 to which trastuzumab binds and demonstrates enhanced antitumor activities when combined with trastuzumab. Here, we developed a tetravalent bispecific antibody (BsAb) which targets the domain 2 and 4 of the HER2 ECD simultaneously. Using time-lapse microscopy, we showed that the BsAb induced aggregation of HER2 on NCI-N87 tumor cells, possibly indicating that the receptors could be crosslinked by the BsAb intermolecularly. Furthermore, the tetravalent BsAb induced aggregation faster than did the bivalent BsAb. Importantly, the tetravalent BsAbs exhibited superior tumor cell growth inhibition to that of the two parental monoclonal antibodies alone or combined. In line with the aggregation rates, the tetravalent BsAb was also more potent in inhibiting tumor cell growth than that of the bivalent BsAb. Thus we provide a piece of evidence that the BsAbs targeting two distinct domains of HER2 simultaneously might induce the receptor aggregation which might associate with the enhanced inhibition of tumor cell growth.

Citation Format: Lan Deng, Jie Zhao, Xiaoqing Meng, Aotian Xiao, Zhenping Zhu, Haomin Huang. Aggregation of HER2 receptors on the tumor cell surface induced by a novel anti-HER2 bispecific antibody led to enhanced tumor cell growth inhibition [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 5287.
Abstract 5308: Therapeutical antibody against CD25 mediating depletion of regulatory T cells without interruption of IL-2 signaling enhances antitumor immunity
Authors: Peng Hao , Hu Shuangshuang , Li Yuli , Ding li , Ning Jinying , Wu Guojin
Published: June 2022

Regulatory T cell or suppressor T cell in tumor diminishes immune response to immunotherapy. CD25, the high-affinity receptor subunit for interleukin (IL)-2, is highly expressed on Treg and considered a selective target for Treg depletion. However, CD25 is also expressed on activated effector T cells (Teff), and antibodies against CD25 with blocking IL-2 signaling have limited antitumor activity. Here we developed a humanized antibody against CD25 (H3F1-4V2) without blocking IL-2 signaling. This antibody was derived from hybridoma of mice immunized with CD25-mFc. Two CD25 antibodies Daclizumab and RG6292 were applied as reference antibodies, and Daclizumab blocked IL-2 signaling, and RG6292 did not block IL-2 signaling. H3F1-4V2 had higher affinity to 293T cells overexpressing human CD25 than Daclizumab (EC50=0.4nM vs 0.45nM), with lower Kd (0.88nM vs 1.5nM). Because of high affinities, H3F1-4V2 and Daclizumab both efficiently depleted Treg from PBMC in vitro, while RG6292 depleted Treg with weaker ability because of low affinity to CD25. In the Teff, downstream signaling of IL-2 was analyzed, and Daclizumab significantly decreased pSTAT5, while RG6292 and H3F1-4V2 kept the pSTAT5 level intact. PBMC was cultured in the presence of CD25 antibodies, and Daclizumab inhibited T cell proliferation (ki67+%) and activation (Granzyme B+%), but not for RG6292 and H3F1-4V2. At last, these CD25 antibodies were tested in humanized mice whose CD25 was replaced with human CD25, and MC38 tumor cells were transplanted into these mice.H3F1-4V2 completely suppressed tumor growth, while RG6292 also suppressed tumor growth with weaker efficiency and Daclizumab had little effect on tumor growth. These results suggested H3F1-4V2 was the best candidate targeting CD25 for cancer therapy.

Citation Format: Hao Peng, Shuangshuang Hu, Yuli Li, li Ding, Jinying Ning, Guojin Wu. Therapeutical antibody against CD25 mediating depletion of regulatory T cells without interruption of IL-2 signaling enhances antitumor immunity [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 5308.
Abstract 5318: Humanized STC10 is a monoclonal antibody to BTN1A1, a novel immunotherapeutic target to be evaluated in a planned phase 1 study
Authors: Howie Lynn Jackson , Chung Ezra M. , Kim Young-Seung , Jung Yujin , Jung Hyunjin , Yoo Stephen
Published: June 2022

Butyrophilin 1A1 (BTN1A1) is a novel immune checkpoint protein that exhibits an expression pattern mutually exclusive to that of PD-1/PD-L1 and may represent a promising therapeutic target for tumors that are anti-PD-1/PD-L1 antibody refractory. BTN1A1 was identified as a potential stress-inducible candidate immune checkpoint using the STCube in vivo immune target discovery platform. Additional analyses revealed that BTN1A1 was highly expressed in multiple human tumor types including urothelial carcinoma and NSCLC, with no overlap between BTN1A1 and PD-1/PDL-1 expression patterns. Mouse studies demonstrated that an anti-BTN1A1 antibody exhibited antitumor activity both as a single agent and in combination with anti-PD-1/PD-L1 or radiation therapy. A humanized anti-BTN1A1 antibody, hSTC810, was developed and found to suppress tumor growth in A549 CDX humanized murine models. Further studies identified Galectin 9 (Gal9) as a BTN1A1 receptor that can form a three protein complex with BTN1A1 and PD-1, thereby suppressing T cell receptor signaling and T cell activation. As high Gal9 expression levels are correlated with poor prognosis in multiple cancers, our results highlight this BTN1A1-Gal9-PD-1 axis as a novel therapeutic target for immunotherapeutic drug development. Given these findings, a first in human study of hSTC810 is in development to evaluate the safety profile of this therapy and to identify a dose for its further evaluation as an anticancer therapy. PK modeling including allometric scaling was performed to conduct simulations to predict the PK profile of hSTC810 after IV administration in humans and to identify possible doses needed to achieve tumor concentrations corresponding to the minimum anticipated biological effect level (MABEL) of 20% receptor occupancy (RO), 80% RO, or 95% RO. The partition coefficient was used to predict concentrations at the tumor site based on predicted serum concentrations. Simulations were performed for 100 subjects after the administration of multiple Q2W doses. The dose of 0.1 mg/kg was predicted to have <20% RO, 0.3 mg/kg to have ~21-35% RO, 1 mg/kg to have ~47-65% RO and 15 mg/kg to have ~93-96% RO at steady state. We anticipate beginning study enrollment in the first quarter of 2022 at sites in the United States sand South Korea. The study is a standard 3+3 dose-escalation with a dose of 0.3 mg/kg for a single patient followed by a starting dose of 1 mg/kg.

Citation Format: Lynn Jackson Howie, Ezra M. Chung, Young-Seung Kim, Yujin Jung, Hyunjin Jung, Stephen Yoo. Humanized STC10 is a monoclonal antibody to BTN1A1, a novel immunotherapeutic target to be evaluated in a planned phase 1 study [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 5318.
Abstract 5322: The antitumor activity and immumodulatory effect of a novel phosphodiesterase 10 inhibitor
Authors: Gazi Md Yeashin , Brandle Caitlin , Okoko Ogacheko , Chen Xi , Keeton Adam , Maxuitenko Yulia , Piazza Gary , Zhou Gang
Published: June 2022

Phosphodiesterase 10 (PDE10) is overexpressed in several types of cancer, including lung, breast and colon cancers. It has been proposed that inhibitors targeting PDE10 may exhibit antitumor activities. Previous studies have shown that PDE10 inhibition can selectively activate cGMP-dependent protein kinase to suppress oncogenic β-catenin signaling in colon cancer cells. However, the impact of PDE10 inhibitors on tumor cell immunogenicity has not been examined. Here we report the antitumor activity and immunomodulatory effect of a novel PDE10 inhibitor (ADT030) in preclinical models. We show that administration of ADT030 significantly inhibited the growth of murine colorectal cancer CT26. In a metastatic breast tumor model (4T1), ADT030 administration not only delayed the growth of the primary tumor but also reduced tumor metastasis, resulting in prolonged mouse survival. Immunological analysis revealed profound reduction of MDSCs in mice, and improved T cell tumor infiltration and function after ADT030 treatment. Moreover, the combination of ADT030 and anti-PD-1 antibody therapy led to further improved tumor growth control and mouse survival. These results implicate PDE10 as a promising therapeutic target and its inhibition may enhance the efficacy of cancer immunotherapy.

Citation Format: Md Yeashin Gazi, Caitlin Brandle, Ogacheko Okoko, Xi Chen, Adam Keeton, Yulia Maxuitenko, Gary Piazza, Gang Zhou. The antitumor activity and immumodulatory effect of a novel phosphodiesterase 10 inhibitor [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 5322.
Abstract 5347: miR-15a & miR-20b enhance sorafenib sensitivity of hepatocellular carcinoma through repressing CDC37L1 and consequent PPIA downregulation
Authors: Li Li , Yu Shijun , Chen Jingde , Quan Ming , Gao Yong , Li Yandong
Published: June 2022

Sorafenib is a classical targeted drug for the treatment of advanced hepatocellular carcinoma (HCC), but intrinsic resistance severely limits its therapeutic effects. In the present study, we aimed to identify crucial genes in HCC cells that affect sorafenib resistance by a CRISPR/Cas9 genome-scale screening. Among the candidates, two miRNAs, miR-15a and miR-20b, were finally identified as the essential sorafenib-sensitizing genes of HCC cells. In parallel, Cell Counting Kit-8 (CCK-8) assay,colony formation assays and flow cytometric analysis were carried out to assess cell proliferation and survival, whereas tumor growth in vivo was assessed using xenograft models. The results indicated that the deficiency of miR-15a and miR-20b contributed to sorafenib resistance of HCC cells. By combination of various bioinformatics tools, Cell division cycle 37 like 1 (CDC37L1) was identified as a common target gene of miR-15a and miR-20b. Further cellular and molecular biology experiments demonstrated CDC37L1 was negatively regulated by the two miRNAs, and CDC37L1 could enhance sorafenib resistance of HCC in vitro and in vivo. Mechanistically, we carried out SDS-PAGE and silver staining assays followed by mass spectrometry to analyze the immunoprecipitated proteins of CDC37L1. Our findings indicated that CDC37L1, as a cochaperone, effectively increased the expression of PPIA through strengthen the binding between HSP90 and PPIA. Additionally, CDC37L1 and PPIA expression were examined in a tissue microarray containing 80 pairs of HCC and normal tissues derived from patients who received sorafenib treatment via immunohistochemistry (IHC) staining, the results revealed a positive association between CDC37L1 and PPIA expression, and high expression of CDC37L1 and PPIA predicted worse prognosis of HCC patients after sorafenib therapy. Taken together, our findings suggest that both miR-15a and miR-20b play sorafenib-sensitizing roles in HCC by facilitating the complex of CDC37L1/HSP90/PPIA.

Citation Format: Li Li, Shijun Yu, Jingde Chen, Ming Quan, Yong Gao, Yandong Li. miR-15a & miR-20b enhance sorafenib sensitivity of hepatocellular carcinoma through repressing CDC37L1 and consequent PPIA downregulation [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 5347.
Abstract 535: Development of a liquid biopsy assay to longitudinally monitor changes in mutations’ allelic frequency in response to treatment with KB-0742
Authors: Amara Suha Naffar-Abu , Noe Christina , Hood Tressa , Paganini Sara , MacKenzie Crystal , Day Melinda A. , Kumar Pavan
Published: June 2022

Liquid biopsies analyzing cell-free DNA (cfDNA) released by tumors are emerging as a powerful noninvasive sampling approach. As opposed to single-site solid tumor biopsy, liquid biopsies allow for better representation of the tumor mutational landscape. In the clinic, liquid biopsies are utilized for early detection of disease, to help inform treatment decisions, to monitor for disease recurrence, and to identify potential resistance mechanisms. Here we describe our approach to developing a liquid biopsy assay that will allow us to monitor, in real time, longitudinal changes in mutations’ allelic frequency in patients with solid tumors. Our approach combines two powerful technologies: next-generation sequencing, that enables the identification of a broad array of mutations, and droplet digital PCR (ddPCR) that provides speed and a cost-effective advantage to monitor mutations in cfDNA obtained from patient plasma samples.

In order to maximize the effectiveness of using liquid biopsy assays in our clinical trial, we prioritized developing an approach that enabled us to meet the following criteria: 1) generating a baseline and end-of-treatment mutational profile for each patient using either a tumor tissue sample or liquid biopsy to identify both driver and potential resistance mutation markers, 2) longitudinal sampling and real-time analysis over the course of treatment, 3) high assay sensitivity to detect low frequency alleles, 4) overall cost-effectiveness, and 5) ability to examine allelic frequency of multiple mutations of interest from limited input of cfDNA isolated from plasma.

Assay development included custom quantification of cfDNA and optimization of a pre-amplification step, which amplified the material allowing us to analyze multiple mutations of interest while ensuring that the quantitative nature of the assay was not impacted. For each individual mutation, gBlocks™ and/or cell-line−derived cfDNA were utilized to optimize annealing temperature and time, cycle number, and input amount to attain an assay with a target 0.1% limit of detection. These customized mutation assays can potentially serve as an accelerated cost-effective surrogate approach, compared to imaging, to monitor in real time the response to KB-0742 (CDK9i) in the ongoing phase 1/2 clinical trial NCT04718675.

Citation Format: Suha Naffar-Abu Amara, Christina Noe, Tressa Hood, Sara Paganini, Crystal MacKenzie, Melinda A. Day, Pavan Kumar. Development of a liquid biopsy assay to longitudinally monitor changes in mutations’ allelic frequency in response to treatment with KB-0742 [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 535.
Abstract 5350: OBX02-011, a reversible fourth-generation EGFR-TKI, overcomes C797S-mediated resistance in non-small cell lung cancer
Authors: Kim Da-Som , Choi Yun Jung , Sung Young Hoon , Kim Dong Ha , Lee Chae Won , Lm Kyungtaek , Lee Hyeonjeong , Kim Sung-Eun , Lee Sunho , Ji Wonjun , Choi Chang-Min , Lee Jae Cheol , Rho Jin Kyung
Published: June 2022

Osimertinib, an irreversible, third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) that is initially developed to overcome EGFR T790M mutation, and use as standard therapy in patients with advanced non-small cell lung cancer (NSCLC) including EGFR activating mutations as well as EGFR T790M mutation. Despite remarkable efficacy of osimertinib, this therapy is limited by the emergence of acquired resistance, like other EGFR-TKIs. Since epidermal growth factor receptor mutation C797S was founded as the factor of acquired resistance to osimertinib, drug targeting the clinically relevant C797S mutation has not yet been developed. Here, we reported the discovery and preclinical efficacy of OBX02-011, fourth EGFR-TKI targeting overcome EGFR C797S mutation. Compared with the approved EGFR-TKIs, this agent showed potent anticancer effects and the inhibition of EGFR-related signaling in various models including EGFR C797S mutation. Additionally, we evaluated the efficacy of OBX02-011 in transgenic models (EGFRL858R+T790M+C797S), showing the enhanced survival, and inhibition of tumor growth and EGFR activity. Collectively, our data suggest that OBX02-011 may be promising new EGFR-TKI to overcome C797S-mediated resistance in NSCLC.

Citation Format: Da-Som Kim, Yun Jung Choi, Young Hoon Sung, Dong Ha Kim, Chae Won Lee, Kyungtaek Lm, Hyeonjeong Lee, Sung-Eun Kim, Sunho Lee, Wonjun Ji, Chang-Min Choi, Jae Cheol Lee, Jin Kyung Rho. OBX02-011, a reversible fourth-generation EGFR-TKI, overcomes C797S-mediated resistance in non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5350.
Abstract 5357: mTOR kinase inhibitor AZD8055 reverses acquired rapamycin resistance in prostate cancer cells
Authors: Dai Yao , Siemann Dietmar
Published: June 2022

The mTOR pathway is frequently over-activated in human cancers. However, classic allosteric mTOR inhibitors rapamycin only exerts limited clinical benefits. It has been shown that prostate cancer are able to acquire resistance after rapamycin treatment for a period of time. Such secondary resistance remains as major concerns in rapamycin-based anti-cancer therapies that may inevitably lead to therapeutic failure. In the current study, we evaluated treatment effects of ATP-competitive dual mTOR kinase inhibitor AZD8055 on cancer cells that have acquired resistance to rapamycin, and underpinning molecular mechanisms. To establish cells with acquired rapamycin resistance, PTEN-mt prostate cancer PC-3 cells were gradually treated with increasing concentrations of rapamycin (up to 10 μM) until the cells were completely unresponsive to rapamycin (PC-3RR). Cell proliferation was determined by MTT assay and clonogenic survival was tested by colony formation assay. m7G pull-down assay was employed to detect the cap-dependent translation. mTOR downstream pathways, including p-S6K (T389)/p-S6 (S235/236), p-4EBP1 (T37/S46) and p-Akt (S473) were detected by Western Blotting. PC-3RR cells essentially failed to respond to rapamycin, with IC50 values greater than 1 μM. However, AZD8055 suppressed PC-3RR proliferation in a dose dependent manner, with IC50 < 30 nM. Similarly, clonogenic capacity was impaired by AZD8055 to a greater extent than was the case for rapamycin. At the molecular level, AZD8055, but not rapamycin, strongly prevents the dissociation of 4E-BP1 from eIF4E. Further, while the p-S6K and p-S6 pathway was potently inhibited by both agents, AZD8055 displayed more striking inhibition on p-4E-BP1 and p-Akt than rapamycin. Interestingly, similar to rapamycin, AZD8055 slightly increased p-Akt (T308), suggesting the existence of the PI3K-mediated feedback loop. These findings indicate that AZD8055 significantly inhibits malignant functions in cancer cells that are highly resistant to rapamycin. Such effects are likely to be associated with the deactivation of rapamycin-insensitive mTOR downstream pathways. These data provide preliminary evidence for future evaluation of ATP-competitive mTOR inhibitors in cancer models that are resistant to rapamycin analogs.

Citation Format: Yao Dai, Dietmar Siemann. mTOR kinase inhibitor AZD8055 reverses acquired rapamycin resistance in prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5357.
Abstract 5362: Targeting PIK3CB in glioblastoma
Authors: Fromherz Marc R. , Pridham Kevin J. , Sheng Zhi
Published: June 2022

Background: Glioblastoma (GBM) is the most common and one of the most lethal malignant brain tumors in existence. The poor prognosis of this disease is due in part to tumor recurrence and temozolomide (TMZ) resistance, for which PI3K/AKT pathway overactivation has been implicated. Our work is to demonstrate that p110β inhibition could represent a therapeutic target in sensitizing recurrent tumors to TMZ therapy, and demonstrate the utility of personalized GBM treatments.

Objective: We aim to develop a more effective treatment for TMZ resistant GBM patients. We hypothesize that a p110β inhibitor will sensitize resistant GBM cell lines to TMZ therapy. We intend to support this hypothesis by demonstrating that the p110β inhibitor TGX-221 in combination with TMZ will provide a significantly greater level of cytotoxicity on TMZ resistant GBM cell lines than TGX-221 or TMZ monotherapy alone. We also intend to provide further evidence for this therapy by utilizing it to overcome TMZ resistance in glioblastoma stem cells (GSC’s).

Methods: We compared the cytotoxicity of TMZ, TGX-221, and a TMZ/TGX-221 combination therapy on p110β-high/TMZ resistant and p110β-low/TMZ sensitive GBM cell lines. Cell viability was determined using the MTS assay. We then tested these reagents on normal human astrocytes to determine any potential dose-limiting off-target effects. Lastly, we tested these reagents using human-derived GSC’s.

Results: A statistically significant difference (p < 0.01) in cell viability was found using the TMZ/TGX-221 combination therapy as compared to either TMZ or TGX-221 alone in our TMZ resistant SF295 cells, and a significant different was found between the combination therapy and TMZ monotherapy in our TMZ resistant U87MG cells. No significant difference was found between treatments in our TMZ sensitive A172 cells or normal human astrocytes.

Conclusions: The results of our GBM cell line experiments provide support that combination TMZ/TGX-211 is superior in cytotoxicity to either monotherapy alone in TMZ resistant cell lines. This indicates that TGX-211, through p110β inhibition, is able to sensitize resistant cell lines to TMZ therapy. More experiments are ongoing to determine if this effect will also be demonstrated in human-derived GSC’s.

Citation Format: Marc R. Fromherz, Kevin J. Pridham, Zhi Sheng. Targeting PIK3CB 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 5362.
Abstract 5374: Amentoflavone induces apoptosis and promotes G1 phase cell cycle arrest through regulating p53 pathway in HT29 human colorectal cancer
Authors: Ku Hsiang-Ju , Chang Yuan , Chiang I-Tsang , Hsu Fei-Ting
Published: June 2022

Amentoflavone (AF) is a nature diflavonoid compound that could extract from Ginkgo biloba and Chamaecyparis obtusa. AF had been proven with many biological properties, including anti-oxidant activity, anti-inflammatory, and could also inhibit NF-κB mediating apoptosis to achieve anti-tumor effects in hepatocellular carcinoma. p53, a tumor suppressor gene that could inhibit cell division and proliferation through regulating with cell cycle and apoptosis related molecules. Patients with p53 gene mutation were often resistant to current standard treatment in clinic. Several studies also reported that the activation of p53 could induce apoptosis in colorectal cancer (CRC). Currently, there is no study determine whether AF can inhibit the growth of colorectal cancer by upregulating p53 gene expression. The aim of this study was to investigate the anticancer effect and the underlying mechanism of AF in CRC in vitro and in vivo. First, we indicated the cytotoxic effect was induced by AF in human CRC (HT29) cells. The suppression of metastasis ability including migration and invasion were found to be suppressed by AF treatment group using transwell assay. Also, in colony formation assay, AF inhibited the proliferation of CRC cells. The tumor suppressor gene p53 was upregulating with AF treatment, and the cell cycle related protein, such as CyclinD1 and CDK4 were all downregulated by AF which identified by Western blotting assay. Additionally, AF induced apoptosis in CRC cells were detected by Western blotting and flow cytometry with cleaved caspase-3, -8, -9 and Annexin V/PI assay. Moreover, Western blotting results indicated that DNA damage proteins (cleaved PARP-1 and ATM) were upregulated by AF. The nucleus translocation of caspase-dependent mitochondria initiated apoptotic protein (EndoG and AIF) were induced by AF in CRC cells. In animal experiments, the CRC tumors volume were effectively reduced in AF treatment groups as compared to non-treated control. In summary, AF mediated anti-CRC effects, such as inhibiting cell proliferation, suppressing migration/invasion ability, inducing apoptosis and triggering DNA damage is associated with the induction of p53.

Citation Format: Hsiang-Ju Ku, Yuan Chang, I-Tsang Chiang, Fei-Ting Hsu. Amentoflavone induces apoptosis and promotes G1 phase cell cycle arrest through regulating p53 pathway in HT29 human colorectal 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 5374.
Abstract 5407: Targeting NRF2 using specific inhibitor brusatol sensitized esophageal adenocarcinoma cells to cisplatin through inducing ferroptosis
Authors: Peng Dunfa , Hu Tianling , Chen Lei , Lu Heng , Zhu Shoumin , El-Rifai Wael
Published: June 2022

Background: The incidence rate of the esophageal adenocarcinoma (EAC) has increased rapidly among men during the past four decades in the USA and western countries while the 5 year survival rate is still below 20%. Traditional chemotherapy is still the main stream strategy in treatment of EAC patients. However, chemo-resistance usually develops that finally leads to failure of treatments. NFE2-related factor 2 (NRF2) is the master regulator of cellular anti-oxidant properties that maintains cell viability and cellular homeostasis. Overexpression of NRF2 in human cancers are associated with drug-resistance and poor prognosis.

Methods and Results: NRF2 protein levels are higher in several EAC cell lines, as compared to BE cell lines (CPA, BAR10T) and normal esophageal squamous cell lines, using Western blot analysis. We confirmed NRF2 overexpression in primary EAC samples, using immunohistochemistry on a tissue microarray that contained 76 EACs. Brusatol is an NRF2 specific inhibitor originated from natural plant. Administration of Brusatol in EAC cells significantly inhibited NRF2 ARE luciferase activity and reduced gene expression of NRF2 target genes such as GR, HO1, GSTM2, GPX3 and GPX4, resulting in a significant increase in cellular ROS levels, which were further increased by treatment with CDDP with subsequent increase in cancer cell death. Further investigation revealed that Brusatol significantly increased lipid peroxidation levels as detected by immunofluorescence assay and flow cytometry and resulted in significant ferroptosis, in particular in combination with CDDP treatments. We confirmed that Brusatol in combination with CDDP significantly suppressed tumor growth in a xenografting mice model.

Conclusion: Constitutive overexpression of NRF2 in EAC cells favors tumor cell survival and drug resistance. NRF2 specific inhibitor may synergize with traditional chemotherapeutic drugs by inducing lipid peroxidation and ferroptosis in EAC.

Citation Format: Dunfa Peng, Tianling Hu, Lei Chen, Heng Lu, Shoumin Zhu, Wael El-Rifai. Targeting NRF2 using specific inhibitor brusatol sensitized esophageal adenocarcinoma cells to cisplatin through inducing ferroptosis [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 5407.
Abstract 5424: Selection of RP3D of xevinapant in combination with CRT in patients with LA SCCHN
Authors: Vugmeyster Yulia , Ravula Abhigyan , Rouits Elisabeth , Diderichsen Paul M. , Kleijn Huub J. , Goteti Kosalaram , Schroeder Andreas , Venkatakrishnan Karthik
Published: June 2022

Xevinapant, an antagonist of Inhibitor of Apoptosis Proteins (IAPs) showed significant improvement in locoregional control at 18 months (LRC18; primary endpoint), overall survival (OS) and progression-free survival (PFS) at an oral dose of 200 mg/day given on days 1-14 every 3 weeks in combination with CRT versus CRT with placebo in a phase II trial in patients with high-risk LA SCCHN (NCT02022098). In the dose escalation (DE) part of NCT02022098, 200 mg/day was the maximum tolerated dose and a trend of dose-response for efficacy in the 100-300 mg/day dose range was observed. The phase III TrilynX study of xevinapant plus CRT in patients with LA SCCHN is currently enrolling (NCT04459715). Here we present the integrated rationale for the recommended phase III dose (RP3D) of xevinapant 200 mg/day based on all available clinical and preclinical data and modeling and simulation (M&S).

At the RP3D, ~95% of the patients are projected to have free trough concentrations above in vitro IC50 for cIAP1 degradation (a pharmacodynamic [PD] marker), based on a population (pop) PK M&S. In patients, average free concentration over the dosing interval at RP3D is similar to that associated with maximal efficacy in preclinical SCCHN models. Pop PK/PD M&S

suggests that maximal cIAP1 degradation is maintained in PBMCs with 100-200 mg/day doses during the 14-day dosing period, with a trend of dose-response for the partial cIAP1 degradation at the end of the 3-week cycle.

Exposure response (E-R) analyses were conducted based on the pooled datasets of DE and randomized parts of study NCT02022098 (n=62 treated with xevinapant). Logistic regressions showed that probabilities of LRC18, overall response, complete response, and the composite safety endpoint of “mucositis and/or dysphagia” increase with increasing exposure (p<0.05). Statistically significant E-R relationships were not discernible for any other evaluated safety endpoints or for PFS, OS, or duration of LRC. However, patients in higher exposure subgroups showed a longer duration of LRC.

In summary, integration of preclinical pharmacology, clinical efficacy and safety profiles, clinical PK/PD, popPK, and E-R analyses support the RP3D selection of xevinapant at 200 mg/day administered on days 1-14 every 3 weeks with concomitant CRT, allowing for successive dose reductions to 150 mg and 100 mg for management of toxicities.

Citation Format: Yulia Vugmeyster, Abhigyan Ravula, Elisabeth Rouits, Paul M. Diderichsen, Huub J. Kleijn, Kosalaram Goteti, Andreas Schroeder, Karthik Venkatakrishnan. Selection of RP3D of xevinapant in combination with CRT in patients with LA SCCHN [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 5424.
Abstract 5447: Enhanced antitumoral effect of the glycosylated 4-methylumbelliferone in hepatocellular carcinoma
Authors: Weiz Gisela , Gonzalez Alina L. , Piccioni Flavia , Fusco Mariel , Gutiérrez Marco Diaz , Mazzolini Guillermo , Breccia Javier D. , Malvicini Mariana , Molejon Maria I.
Published: June 2022

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related death worldwide, and is particularly refractory to the available therapeutic drugs. Unfortunately, curative treatments such as surgery, liver transplantation, or ablation are reserved for early stages and can only be applied in less than 30% of the patients with HCC. Glycosylation can be a potent and interesting strategy for drug delivery to a specific target. We enzymatically synthesized a glycosylated derivative of the coumarin 4-methylumbelliferone (4MU), namely 4MUR.The antitumoral effect of 4MUR in comparison with the aglycone 4MU was evaluated onto liver cancer cells. Cellular toxicity was determined on murine liver tumor cell lines as well as non-hepatic tumoral cells. Tumor cell lines were significantly more sensitive than non-tumoral cells to the glycosylated molecule in a dose-dependent manner (p<0.05). 4MUR was incorporated mostly into tumoral cells by the interaction with the asialoglycoprotein receptor (ASGPR), which is overexpressed in liver tumor cells. Hyaluronic acid (HA) is the major component of the extracellular matrix (ECM). It is produced at the plasma membrane by three hyaluronan synthases (HAS1, 2 and 3), which couple glucuronic acid and N-acetylglucosamine into a linear polymer using the corresponding UDP-sugars (UDP-GlcUA and UDP-GlcNAc) as substrates. Unlike 4MUR, the glucuronidation of 4MU competitively inhibits chain elongation of HA. Furthermore, 4MUR treatment regulates the levels of HAS2 and HAS3 expression in the tumoral cell line. Finally, 4MUR treatment induced apoptosis cell death in tumoral cells. Our results suggest that the 4MUR is safe and effective against liver tumor cells via a specific targeting to ASGPR receptor and decreasing HA synthesis.

Citation Format: Gisela Weiz, Alina L. Gonzalez, Flavia Piccioni, Mariel Fusco, Marco Diaz Gutiérrez, Guillermo Mazzolini, Javier D. Breccia, Mariana Malvicini, Maria I. Molejon. Enhanced antitumoral effect of the glycosylated 4-methylumbelliferone in hepatocellular carcinoma [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 5447.
Abstract 5448: Synergistic antitumor effect of ONC201, radiotherapy and temozolomide in glioblastoma mouse orthotopic models
Authors: Zhou Lanlan , Wu Jinxuan Laura , Safran Howard P. , El-Deiry Wafik S.
Published: June 2022

Glioblastoma (GBM) is the most common and lethal primary brain tumor in adults with a median survival of just over a year and a two-year survival of about 30%. Only 10% of people survive five years of this grade IV cancer. Standard of care therapy comprises maximal safe surgical resection followed by adjuvant alkylating agent temozolomide (TMZ) and radiotherapy conferring a median survival time of 14.6 months compared with 12.1 months for GBM patients treated with radiotherapy alone. First-in-class small-molecule imipridone ONC201 has shown efficacy in glioblastoma models in vitro, in vivo, and ex vivo. It is also orally active and is administered once every week, a favorable dosing schedule for patients. We hypothesized that ONC201 may synergize with radiotherapy and Temozolomide in GBM in vitro and in vivo. We previously reported that ONC201 synergizes with radiotherapy and/or TMZ to inhibit cell viability and colony formation and induce ER stress and apoptosis in GBM cells. To pursue this promising combinational therapy in vivo, we established GBM mouse orthotopic models through intracranial injection of luciferase expressing GBM cells U-251-LUC with a KOPF model 940 small animal stereotaxic frame and a Stoelting Quintessential Stereotaxic Injector. Tumor formation was confirmed with bioluminescence imaging. Randomized treatment group mice have received weekly treatment of ONC201 (100 mg/kg p.o.) and/or radiotherapy (2 Gy local irradiation) and/or TMZ (20 mg/kg i.p.) for four weeks. We observed the triple combination of ONC201 and radiotherapy and TMZ significantly reduced tumor burden and prolonged survival compared to dual combinations in GBM mouse orthotopic model U-251-LUC. We are currently exploring the synergistic mechanisms of triple combination including TRAIL signaling pathway, ISR, dopamine receptors and mitochondrial ClpXP, and potential pharmacodynamic biomarkers from in vivo samples. Our study suggests that the investigational triple combination therapy of ONC201 and radiotherapy and TMZ is going to be an important option for patients with GBM.

Citation Format: Lanlan Zhou, Jinxuan Laura Wu, Howard P. Safran, Wafik S. El-Deiry. Synergistic antitumor effect of ONC201, radiotherapy and temozolomide in glioblastoma mouse orthotopic models [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 5448.
Abstract 5451: New organoselenium compounds with cytotoxic activity in vitro and in vivo towards colon cancer
Authors: Ramos-Inza Sandra , Aliaga Cesar , Raza Asif , Encío Ignacio , Sharma Arun , Sanmartín Carmen , Plano Daniel
Published: June 2022

Colon cancer is currently the third most common diagnosed cancer and the second leading cause of cancer death worldwide. The inclusion of a selenium atom (Se) in organic molecules has been shown to be a valid approximation in the design of novel chemotherapeutic agents with antitumoral activity. On the other hand, non-steroidal anti-inflammatory drugs (NSAIDs) have gained interest in recent years in terms of their chemopreventive and chemotherapeutic use for cancer treatment whether they are evaluated alone, as a combination therapy, or in the form of structurally modified analogs. Considering these findings, we have designed five novel NSAID derivatives containing Se in their structure. The cytotoxicity and selectivity of the new compounds were evaluated in a panel of 10 cancer cell lines including breast, prostate, lung, and colon cancer, and in two non-malignant cell lines. Compound 5 was the most cytotoxic derivative with IC50 values below 10 µM in all the cancer cell lines tested, and it was also the most selectively toxic towards cancer cells while sparing the non-malignant cell lines. The efficacy of compound 5 in vivo was assessed in a subcutaneous colon cancer xenograft mouse model and it showed a significant inhibition of the tumor growth. Taken together, this work supports that the novel Se-NSAID combination provides a feasible frame to develop new agents with potent antitumoral properties

Citation Format: Sandra Ramos-Inza, Cesar Aliaga, Asif Raza, Ignacio Encío, Arun Sharma, Carmen Sanmartín, Daniel Plano. New organoselenium compounds with cytotoxic activity in vitro and in vivo towards colon 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 5451.