bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract PO-001: HDAC6 inhibitors sensitize non-mesenchymal triple-negative breast cancer cells to cysteine deprivation
Authors: Alothaim Tahiyat , Charbonneau Morgan , Tang Xiaohu (Mark)
Published: April 2021

Triple-negative breast cancer (TNBC) accounts for 15% ~ 20% of overall breast cancer cases and exhibits earlier age of onset, high metastasis, and aggressiveness with poor clinical outcomes shown by higher relapse and lower survival rates than other types of breast cancer. TNBC contributes to the major mortality of breast cancer patients. Treatments of TNBC patients are still limited to surgery, chemotherapy, or radiation since the absence of cell receptors makes targeted hormonal therapies impossible. Targeting cysteine-dependence is an emergent strategy to treat the mesenchymal TNBC. However, many TNBC cells are non-mesenchymal and irresponsive to cysteine deprivation. To overcome such resistances, three selective HDAC6 inhibitors (Tubacin, CAY10603, and Tubastatin A), identified by epigenetic compound library screening, can synergize with cysteine deprivation to induce cell death in the non-mesenchymal TNBC. Despite the efficacy of the HDAC6 inhibitor, knockout of HDAC6 did not mimic the synthetic lethality induced by its inhibitors, particularly tubacin, indicating that HDAC6 is not the actual target of HDAC6 inhibitor in this context. Instead, transcriptomic profiling showed that tubacin triggers an extensive gene transcriptional program in combination with erastin, a cysteine transport blocker. Notably, the zinc-related gene response and an increase of labile zinc were induced in cells by the combination treatment. We found that the disturbance of cellular zinc homeostasis was driven by PKCγ activation, which revealed that the PKCγ signaling pathway is required for HDAC6 inhibitor-mediated synthetic lethality. Overall, our study identifies a novel function of HDAC6 inhibitors that function as potent sensitizers of cysteine deprivation. HDAC6 inhibitors are capable to overcome cysteine independence in non-mesenchymal tumor cells, which allows the application of targeted cysteine-dependence therapy in various subtypes of breast cancer.

Citation Format: Tahiyat Alothaim, Morgan Charbonneau, Xiaohu (Mark) Tang. HDAC6 inhibitors sensitize non-mesenchymal triple-negative breast cancer cells to cysteine deprivation [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-001.
Abstract PO-007: 18O-substituted nucleosides combined with proton beam: “Theranostic transformation.”
Authors: Rich Tyvin , Pan Dongfeng , Chordia Mahendra , Keppel Cynthia , Jung Mira , Pang Dalong , Beylin David , Grindrod Scott , Dritschilo Anatoly
Published: April 2021

Therapeutic protons (PRT) cause atomic transmutation of 18O to 18F producing positrons and release neutrons. We hypothesize that targeted production of 18F may be achieved with an 18O containing nucleoside that incorporates into DNA and when exposed to PRT alters local chemical behavior. PRT radiation sensitization (RS) was tested in SQ20-B squamous carcinoma and PC3 prostate cancer cells treated with 18O substituted C2-18O-thymidine (18O-TD), C2-18O-Uridine (18O-UD) and also the thymidine analogs IUdR and substituted 5’-18O-5-iododeoxyuridine (18O-IUdR). Proton RS data are reported for Log phase cells exposed to these substituted nucleosides at physiologic concentrations of 5 -10 µM for 48 hours and re-plated in fresh media. PRT 24 hours later delivered 1 to 9 Gy using an 85 MeV beam at the Bragg peak. Survival fractions were determined by colony assays in triplicate for combined treatment vs. PRT alone. The single hit multi-target model was applied to demonstrate RS with dose modification factors of 1.2 for 18O-TD, 1.3 for IUdR, and 1.5 for 18O-IUdR. RS was not seen with 18O-TD, 18O-UD, or H218O irradiated with gamma rays, nor those treated with 18O-UD or H218O combined with PRT (no changes in D0). PRT of H218O with 10 Gy yielded positron emission tomography images in vitro initiated >45 minutes after PRT with a decay signal with T1/2 of ~111 min. We conclude that 18O-substituted nucleosides activated by therapeutic PRT create in situ 18F that may open up new strategies for RS. A wide PRT therapeutic window could result from the metabolic, physical, and chemical effects of “theranostic transmutation” with 18O labelled nucleosides.

Citation Format: Tyvin Rich, Dongfeng Pan, Mahendra Chordia, Cynthia Keppel, Mira Jung, Dalong Pang, David Beylin, Scott Grindrod, Anatoly Dritschilo. 18O-substituted nucleosides combined with proton beam: “Theranostic transformation.” [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-007.
Abstract PO-016: Changes in the expression levels of DNAJAs in triple negative breast cancer cells exposed to cytotoxic chemotherapy
Authors: Freeny Devon
Published: April 2021

Triple Negative Breast Cancer (TBNC) lacking biological targets results in limited therapeutic options and leads to high mortality rates. The last therapy is Doxorubicin (Cytotoxic chemotherapeutic drug), an anti-tumor therapeutic alternative; which has bad side effects (cardiotoxicity), due to dose dependence, leading to drug resistance. There are three primary mechanisms of action for doxorubicin: Intercalation into DNA, which directly affects transcription and replication. Inhibition of topoisomerase II activity during the double-strand break, which prevents the binding portion of the ligation reaction that topoisomerase II catalyzes, by stabilizing the DNA-topoisomerase II alpha complex. Lastly, generating free radicals as it cycles between its quinone and semi-quinone structures during metabolic reactions, which generates reactive oxygen species. Research says heat shock proteins (HSPs) help to protect cells using heat-shock response. Several HSPs have been tested, with limited knowledge of HSP40s (DNAJAs). We will determine which DNAJA (1 to 4) assists in the survival response to doxorubicin by observing the domains and expression of the proteins being exposed to chemotherapy. The J domain has shown to be a critical area for increasing cell sensitivity while reducing cardiotoxicity. Expression levels were analyzed via RT-PCR and Western Blots, and relevant domains via COSMIC database. In conclusion the first step to reducing cardiotoxicity with chemotherapeutics is by modifying HSP40 functionality in human cancer cells, providing an alternative to hypersensitization to chemotherapy, allowing for lower dosage with less side effects.

Citation Format: Devon Freeny. Changes in the expression levels of DNAJAs in triple negative breast cancer cells exposed to cytotoxic chemotherapy [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-016.
Abstract PO-023: Impact of a novel Ku-DNA binding inhibitor on the IR-induced DNA damage response
Authors: Mendoza-Munoz Pamela , Gavande Navnath S. , VanderVere-Carozza Pamela S. , Pawelczak Katherine S. , Dynlacht Joseph R. , Garrett Joy , Turchi John J.
Published: April 2021

The DNA-dependent protein kinase (DNA-PK) plays a critical role in the non-homologous end joining (NHEJ) double stand break (DSB) repair pathway and the DNA damage response (DDR). Consequently, blocking DNA-PK kinase activity is a novel anti-cancer therapeutic strategy in combination with ionizing radiation (IR). Towards developing a series of a new class of DNA-PK inhibitors, our laboratory has exploited the mechanism of DNA-PK activation which requires binding to DNA termini via the Ku 70/80 heterodimer. We recently reported the development of Ku-DNA binding inhibitors (Ku-DBi’s) that act via this novel mechanism of action to inhibit DNA-PK catalytic kinase activity. Ku-DBi’s display nanomolar activity in vitro, possess cellular DNA-PK and NHEJ inhibitory activity and sensitize non-small cell lung cancer (NSCLC) cells to chemotherapeutics bleomycin and etoposide. In this study, we demonstrate that pre-incubation of our novel Ku-DBi’s can potentiate the cellular effects of IR. We demonstrate that the increase in IR sensitivity is preceded by a decrease in DNA-PKcs autophosphorylation events at the S2056 (pS2056) cluster. Using a combination of Western blot and immunofluorescence assays in the NSCLC NCI-H460 cell line, Ku-DBi 245 treatment in combination with IR showed a significant reduction of phosphorylation of DNA-PKcs at S2056 compared to IR alone. Analysis of gH2A.X also showed an inhibition of the DDR as a function of 245 treatment, evidenced by reduction of S139 phosphorylation. These results demonstrate that Ku-DBi 245 blocks DNA-break dependent DNA-PKcs autophosphorylation, resulting in an increased in radiation sensitivity. These data are consistent with Ku-DBi’s possessing a novel mechanism of action that abrogates autophosphorylation of DNA-PKcs and DDR signaling as part of an anticancer therapeutic strategy in combination with IR.

Citation Format: Pamela Mendoza-Munoz, Navnath S. Gavande, Pamela S. VanderVere-Carozza, Katherine S. Pawelczak, Joseph R. Dynlacht, Joy Garrett, John J. Turchi. Impact of a novel Ku-DNA binding inhibitor on the IR-induced DNA damage response [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-023.
Abstract PO-024: Paclitaxel induced apoptosis through ROS production and eliminated cellular senescence in PC9-MET cells
Authors: Mohiuddin Md , Kasahara Kazuo
Published: April 2021

Background: Paclitaxel is used as first-line and subsequent therapy for the treatment of various cancers. However, the mechanisms by which paclitaxel exerts its anticancer activity against non-small cell lung cancer (NSCLC) are not well understood. This study aimed to investigate paclitaxel's role in cell proliferation, apoptosis, and cellular senescence of PC9-MET (gefitinib-resistant) cells and reveal the underlying mechanisms. Methods: PC9-MET cells were treated with paclitaxel for 72 h and then evaluated by cell viability assay, Giemsa staining, DAPI staining, apoptosis assay, SA-β-Gal staining, ROS assay, TUNEL assay and western blotting. Results: Our results revealed that paclitaxel significantly reduced the viability of PC9-MET cells and induced morphological signs of apoptosis. The apoptotic effects of paclitaxel were observed by increased levels of cleaved caspase-3, cleaved caspase-9 and cleaved PARP. Additionally, paclitaxel increased ROS production, leading to DNA damage. Importantly, paclitaxel eliminated cellular senescence, which was observed by SA-β-Gal staining. Conclusion: In light of these findings, paclitaxel could be a promising agent for cancer treatment against human PC9-MET (gefitinib-resistant) cells.

Citation Format: Md Mohiuddin, Kazuo Kasahara. Paclitaxel induced apoptosis through ROS production and eliminated cellular senescence in PC9-MET cells [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-024.
Abstract PO-025: Radiation-induced and FACS-sorted senescent tdTOMp16+ cells upregulate profibrotic genes in C57BL/6 stromal target cells
Authors: Mukherjee Amitava , Epperly Michael , Shields Donna , Hou Wen , Fisher Renee , Hamade Diala , Greenberger Joel S.
Published: April 2021

Acute Radiation Syndrome and the multiorgan failure from delayed effects of acute radiation exposure present challenging consequences of radiation terrorism or a radiological accident. Recent research suggests that radiation-induced cellular senescence plays an important role in radiation-induced pulmonary fibrosis (RIPF), and that clearance of senescent cells (SCs) could be an effective therapeutic strategy. However, the identification and targeted removal of only senescent cells using drugs have been difficult. Here we have established a bone-marrow stromal cell line from a tdTOMp16+ mouse. We show that 5 Gy irradiation induces ~9% cellular senescence in tdTOMp16+ stromal line after 10 days and can be isolated as a pure population of red tdTOMp16+ cells by FACS sorting. To confirm that these irradiated and then sorted red cells are senescent, we cultured them as single cells in 96-well plates and followed for four weeks. None of the 960 irradiated red cells we plated divided after 2 weeks, 137 of these cells remained intact and assumed large and flat cellular morphology. In contrast, 50 of 800 cells that were irradiated but didn’t turn red, divided, as did 104 of 560 nonirradiated control cells (0 Gy) divided. There was significant upregulation of senescent cell markers including SA-ß-gal, p16, and p21 in the irradiated and sorted red cells when compared to irradiated nonred cells. Sorted irradiated red, non-irradiated, or irradiated non-red cells were placed on the top well of transwells. There was a significant induction of fibrotic genes Ctgf, Tgf- ß, collagen 1a, and collagen 3 in C57/B6 stromal target cells in the bottom layer by irradiated red cells, but not the other cell populations irradiated non-red. Thus, radiation-induced biomarkers of fibrosis are induced by senescent cells.

Citation Format: Amitava Mukherjee, Michael Epperly, Donna Shields, Wen Hou, Renee Fisher, Diala Hamade, Joel S. Greenberger. Radiation-induced and FACS-sorted senescent tdTOMp16+ cells upregulate profibrotic genes in C57BL/6 stromal target cells [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-025.
Abstract PO-026: DNA damage response and repair characterization in CHK2-deficient cancers
Authors: Muñoz-Maldonado Carmen , Quintin Aurélie , Aebersold Daniel M. , Zimmer Yitzhak , Medová Michaela
Published: April 2021

Double strand breaks (DSBs) are the most lethal DNA lesions as they can result in chromosomal rearrangements or loss of genetic material. To detect and repair DNA, cells have developed the DNA damage response, a cascade of proteins in which the checkpoint kinase 2 (CHK2) is involved. CHK2-deficient cancers, such as breast, prostate or colon, might have a compromised response to ionizing radiation (IR), arresting cell cycle at checkpoints or inducing apoptosis in presence of irreparable damage. To understand how the lack of CHK2 is affecting DNA damage response and repair, the human isogenic HCT116 colorectal cancer cell lines proficient (CHK2 WT) and deficient (CHK2 KO) for CHK2 have been characterized. Cell cycle distribution and γH2AX foci formation were assessed by flow cytometry and immunofluorescence, respectively, to determine the differences in cell cycle checkpoints and DSBs infliction and resolution upon IR. Traffic Light Reporter, complemented by immunofluorescence of RAD51 foci, was employed in both CHK2 WT and KO cell lines to identify the preferred DSB repair pathway. Our results indicate that CHK2-proficient and -deficient cell lines do not exhibit significant differences in cell cycle distribution upon IR. On the other hand, CHK2 KO cells display a significant increase in γH2AX foci per cell compared to the CHK2 WT. Upon 1Gy of IR, cells lacking CHK2 increment the number of foci per cell, indicating that DSBs detection occurs independently of the CHK2 status. Furthermore, the Traffic Light Reporter revealed higher homologous recombination (HR) to non-homologous end-joining (NHEJ) ratio in the CHK2 KO cells as compared to their CHK2 WT counterparts, suggesting that the lack of CHK2 stimulates a shift in the DSBs repair pathway choice. These results contrast with the RAD51 foci formation, which seems to be compromised in the CHK2 KO cells in both treated and untreated conditions as compared to the CHK2-proficient cells. Our results suggest that CHK2 status considerably affects cellular DNA damage response and these differences in execution of DNA repair could be exploited in CHK2-deficient cancers.

Citation Format: Carmen Muñoz-Maldonado, Aurélie Quintin, Daniel M. Aebersold, Yitzhak Zimmer, Michaela Medová. DNA damage response and repair characterization in CHK2-deficient cancers [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-026.
Abstract PO-038: Hide and Seq: Radiation-induced immunogenicity of patient tumors revealed by single cell analysis
Authors: Chow Jacky L. , Hoffend Nicholas , Gaudieri Madeline , Abrams Scott , Schwaab Thomas , Singh Anurag , Muhitch Jason
Published: April 2021

Robust preclinical investigations into radiation-induced immunogenicity has led to increased enthusiasm for combining radiation with immunotherapy. Promising results in a limited number of patients treated with radiotherapy and immune-activating strategies has supported the initiation of over 150 ongoing clinical trials. Yet, due to reduced availability of patient samples following treatment, tumor tissue in particular, there has been sparse investigation of the impact of radiation on immunogenicity in human malignancies. While murine models have revealed important insights into understanding radiation-induced immunogenic mechanisms, inherent differences in radiation sensitivity between mice and humans limit translation to patients. To determine the impact of radiation on patient tumor cells we analyzed samples from renal cell carcinoma (RCC) patients treated with stereotactic body radiation therapy (SBRT) in a pilot study (NCT01892930). Previous data showed radiation induced surface presentation of tumor-associated antigens in resected irradiated tumors. Bulk transcriptomic data of in situ-irradiated tumors showed evidence of immune activation, including increased interferon-gamma (IFNG) signaling, as well as increased T cell clonality and higher abundance of T cells clones with similar binding affinities predicted by dominant motif analysis. We hypothesized that the tumor response to in situ irradiation included increased transcript abundance for tumor antigen genes and antigen-presentation machinery, as well as a response to IFNG signaling. Tumor cell comparisons following single-cell RNA sequencing uncovered RCC cell-specific responses to in situ irradiation. Irradiated RCC tumor cells expressed higher levels of genes encoding MUC-1 and carbonic anhydrase 9, as well as higher expression of calreticulin and genes encoding MHC class 1 molecules: HLA-A, HLA-B, and HLA-C; furthermore, gene set enrichment identified enhancement of antigen processing and presentation pathways. Additionally, irradiated tumor cells expressed higher levels of the IFNG receptor, its downstream targets, and the enrichment of several interferon response gene sets. Collectively, these results indicate radiation may improve tumor recognition through both increased antigen expression and surface presentation as well as sensitize tumor cells to immunogenic cytokines and T cell-mediated cytolysis in human malignancies, such as RCC.

Citation Format: Jacky L. Chow, Nicholas Hoffend, Madeline Gaudieri, Scott Abrams, Thomas Schwaab, Anurag Singh, Jason Muhitch. Hide and Seq: Radiation-induced immunogenicity of patient tumors revealed by single cell analysis [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-038.
Abstract PO-039: Radiation therapy enhances anti-tumor activity of a MET CAR T-based immunotherapy approach for glioblastoma multiforme
Authors: Hovhannisyan Lusine , Aebersold Daniel M. , Maher John , Ochsenbein Adrian F. , Riether Carsten , Medova Michaela , Zimmer Yitzhak
Published: April 2021

Glioblastoma multiforme (GBM) is the most prevalent primary malignant brain tumor, which has an aggressive phenotype and mostly fatal recurrence after standard therapy. MET, the hepatocyte growth factor (HGF) receptor is a relevant target for GBM treatment as it is expressed in up to 50% of cases and its expression, which may be induced by radiation therapy (RT), can potentially contribute to RT-resistance of GBM stem cells, and tumor recurrence. MET-based chimeric antigen (CAR) T cell therapy is currently being evaluated in several solid tumor working settings. A combination of T cell-based therapies with RT may improve the efficacy of the CAR T cell therapy through by the RT-induced immune activation via release of cytokines and induction of antigen expression, similarly as has been observed when combining RT with immune checkpoint inhibitors. Here we investigated the combination of MET-targeting CAR T cells with RT for GBM treatment, hypothesizing enhanced anti-tumor effects. The current study used a panel of MET-proficient and MET-deficient human GBM and GBM stem-like cell lines. Cells have been irradiated with a single dose of 0, 2, 5, or 10 Gy and RT impact on MET expression has been assessed at various time points after RT administration. Results show MET increase after RT in some cell lines. To test MET-targeting CAR T effect on the GBM cell lines, CAR constructs that are based on HGF-MET binding elements have been introduced into virus-producing cells and used for human T cells transduction to generate MET-targeting CAR T cells. CAR T cells co-cultured with GBM cell lines in vitro have specifically and significantly decreased viability of MET-positive cancer cells. Data resulting from combination of RT and CAR T cells treatment suggest that radiation exhibits an enhancement of CAR T cells anti-tumor killing activity, indicating a synergism between the two modalities. In conclusion, our data are the first to indicate the efficacy of a MET-based CAR T immunotherapy approach in GBM cell lines. The results also demonstrate a basis for the combination of a MET CAR T modality together with RT. The mechanisms for understanding the interaction between RT and the MET CAR T cells are under investigation.

Citation Format: Lusine Hovhannisyan, Daniel M. Aebersold, John Maher, Adrian F. Ochsenbein, Carsten Riether, Michaela Medova, Yitzhak Zimmer. Radiation therapy enhances anti-tumor activity of a MET CAR T-based immunotherapy approach for glioblastoma multiforme [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-039.
Abstract PO-041: An immunologic niche of antigen presenting cells and stem-like CD8+ T-cells is present in non-small cell lung cancer brain metastases
Authors: Jansen Caroline S. , del Balzo Luke , Prabhu Roshan , Logan Suzanna , Chappa Prasanthi , Patel Kirtesh , Wilkinson Scott , Lake Ross , Shu Hui-Kuo G. , Zhong Jim , Dhere Vishal , Olson Jeffrey , Sowalsky Adam G. , Khan Mohammad K. , Kissick Haydn T. , Buchwald Zachary S.
Published: April 2021

Background: Non-small cell lung cancer (NSCLC) patients with brain metastases have a very poor prognosis. The first line treatments for NSCLC brain metastases are typically surgery and pre- or post-operative stereotactic radiosurgery (SRS) or SRS alone. However, subsequent intra-cranial failure and death is common. Importantly, we have previously shown that a unique immune niche in genitourinary malignancies correlates with the risk for disease recurrence. Accordingly, here we investigated whether this immune niche was present in brain metastases, whether it correlated with patient outcomes, and whether it was modulated by SRS. Methods: Formalin fixed paraffin embedded brain metastases were stained by immunofluorescence for CD8, PD-1, TCF-1, MHC-II and DAPI. Following successful image acquisition using fluorescent whole slide scanning, we used a custom quantitative analysis pipeline to measure the cellularity, relative cellular locations, local cellular density, and marker staining intensity. Results: We identified immune niches consisting of both stem-like TCF-1+ CD8+ T-cells and antigen presenting cells (MHC-II+) in brain metastases. TCF-1+ CD8+ T-cells were found at in areas of higher MHC-II+ cell density than the TCF-1 CD8+negative T-cells. The amount of tumor issue occupied by immune niches correlated with TCF1+ CD8+ T-cell infiltration, as well as with total CD8+ T-cell and MHC-II+ cell infiltration. Importantly, we found that higher MHC-II+ cell density correlated with longer overall survival in this cohort of patients. Additionally, we found this immune niche is preserved following pre-operative SRS. Conclusions: Our study is the first to demonstrate stem-like CD8+ T-cells in brain metastases and that these cells form an immune niche similar to those described extra-cranial tumor sites. Additionally, we report that the immune niche is preserved following SRS, which is highly clinically relevant to the use of combinatorial strategies between SRS and checkpoint blockade.

Citation Format: Caroline S. Jansen, Luke del Balzo, Roshan Prabhu, Suzanna Logan, Prasanthi Chappa, Kirtesh Patel, Scott Wilkinson, Ross Lake, Hui-Kuo G. Shu, Jim Zhong, Vishal Dhere, Jeffrey Olson, Adam G. Sowalsky, Mohammad K. Khan, Haydn T. Kissick, Zachary S. Buchwald. An immunologic niche of antigen presenting cells and stem-like CD8+ T-cells is present in non-small cell lung cancer brain metastases [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-041.
Abstract PO-056: Sonographic and photoacoustic monitoring of radiation-induced parenchymal and vascular injury to salivary glands
Authors: Bolookat Eftekhar Rajab , Vincent-Chong Vui King , Singh Anurag K. , Seshadri Mukund
Published: April 2021

Salivary gland dysfunction is a common side effect of radiation therapy (RT) in patients with head and neck cancer and is a consequence of direct damage to glandular parenchyma along with inflammatory changes and vascular injury following radiation. However, dynamic functional imaging of changes in salivary gland vascularity and oxygenation following RT has not been previously reported. Here, we employed bimodal photoacoustic imaging (PAI) with co-registered ultrasound (US) to non-invasively monitor radiation-induced parenchymal and vascular injury to salivary glands in vivo. Experimental imaging studies revealed parenchymal damage on B-mode US and early increase in vascular resistance on contrast-enhanced US (within 24h following radiation). Notably, this was accompanied by a reduction in oxygen consumption of salivary glands on dynamic PAI following parasympathetic stimulation with pilocarpine. Temporal kinetics of radiation-induced vascular injury was dependent on the host immune status and correlates with stimulated salivary secretion. These findings demonstrate the ability of US-PAI to monitor the dynamic changes in neurovascular coupling of salivary glands following radiation injury and highlight its potential utility to identify drugs or therapeutic approaches that could protect or mitigate radiation-induced vascular damage.

Citation Format: Eftekhar Rajab Bolookat, Vui King Vincent-Chong, Anurag K. Singh, Mukund Seshadri. Sonographic and photoacoustic monitoring of radiation-induced parenchymal and vascular injury to salivary glands [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-056.
Abstract PO-058: Acute total body ionizing radiation induces long-term cardiac effects and immediate changes in oxidative carbonylation of cardiac troponin T in the rat
Authors: Rosen Elliot
Published: April 2021

Radiation-induced heart disease represents a significant health risk in the event of an accidental radiation exposure as well as to cancer patients who receive acute doses of irradiation as part of radiation therapy. We utilized the Wistar-Kyoto and spontaneously hypertensive rat models, previously shown to demonstrate drug-induced cardiomyopathy, to evaluate the acute and long-term effects of sub-lethal total body irradiation at two, four, and fifty-two weeks. We examined irreversible oxidative protein carbonylation in the heart immediately following irradiation. Both males and females sustained reduced growth and anemic conditions over a one-year period as reflected by reduced body weight and low red blood cell count. Increased inflammation was detected via elevated IL-6 serum levels selectively in males at four weeks. Serum cardiac troponin T and I analyses revealed signs of cardiomyopathy at earlier timepoints, but high variability was observed, especially at one year. Echocardiography at two weeks following 5.0 Gy treatment revealed inflammation and a decrease in cardiac output in the short term, but significant differences were not observed at the one-year timepoint. Cardiac output was decreased in both males and females after two weeks, and statistically significant in females. Following 10.0 Gy irradiation, the heart tissue showed an increase in total protein oxidative carbonylation accompanied by DNA damage indicated γ-H2AX. Using proteomic analyses, several novel proteins showed a marked carbonylation profile including those associated with mitochondrial homeostasis and cardiac contractility, most notably, cardiac troponin T. Overall, we present findings of acute oxidative protein, DNA damage, and long-term cardiomyopathy in the irradiated animals, along with oxidative proteomic markers of acute damage.

Citation Format: Elliot Rosen. Acute total body ionizing radiation induces long-term cardiac effects and immediate changes in oxidative carbonylation of cardiac troponin T in the rat [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-058.
Abstract PO-062: Why drug and radiation combination synergism or antagonism can be quantitatively determined with the mass-action law based pharmacodynamics equation, algorithm and computer simulation
Authors: Chou Ting-Chao
Published: April 2021

Biological system-analysis by the mass-action law with biophysical, biochemical and mathematical induction-and-deduction leads to the derivation of >300 reaction rate equations. These derived equations led to general biodynamics/pharmacodynamics and bioinformatics (MAL-BD/PD/BI) general paradigms for “Dose” and “Effect”. 1. Median-Effect Eq. (MEE) for single drug or entity, regardless, in vitro, in animals or in human, where Dm and m values signify the median-effect dose “potency” and “shape” (dynamic order), respectively. 2. Combination Index Eq. (CIE), where CI<1, =1, and >1 indicates synergism, additive effect and antagonism, respectively, in combinations. Since all terms in MEE and CIE are relativity ratios, they are dimensionless quantities. Therefore, MEE and CIE are fundamental MAL-BD/PD/BI/CI principle independent to entity’s physical nature (chemicals, biologicals, natural products, radiation, liquid, or gas); independent to unit (ug, nM, mg/ml. mg/kg, IU, rad or multiples of infection); and independent to mode or mechanism of actions (competitive, noncompetitive, uncompetitive, sequential, ordered, ping-pong or random). Comprehensive details are available in Chou TC, Pharmacol. Rev. 58: 621-681, 2006 (specifically on p.655 and p.660), It also discussed in Chou, Integrative Biol. 3: 548-559, 2011, and many more recent papers on chemotherapy and radiation therapy combinations, as indicated in Google scholars. The above 2006 Chou article, as of January 12, 2021, has 3,835 citations in 1,054 biomedical journals internationally, encompassing nearly all disciplines in biomedical sciences.

Citation Format: Ting-Chao Chou. Why drug and radiation combination synergism or antagonism can be quantitatively determined with the mass-action law based pharmacodynamics equation, algorithm and computer simulation [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-062.
Abstract PO-087: Novel high-throughput screen in a breast cancer cell line to identify potent radiosensitizers
Authors: Landry Madeleine R. , DuRoss Allison N. , Choi Eunseo , Jozic Antony , Nelson Dylan , Sun Conroy
Published: April 2021

There is a need for more broadly applicable radiosensitizers independent of disease state and DNA protein repair status. High throughput screens hold potential for identifying new classes of radiosensitizers from libraries of small molecules. Our group has developed an in vitro high throughput screen identifying radiosensitizers using high content imaging. Due to chromatin condensation, G2/M is acknowledged as the most radiosensitive phase of the cell cycle. We therefore dosed 4T1 breast cancer cells with a library of 1430 FDA approved drugs, then using the high content images, assessed ability to stall in G2/M. We initially eliminated drugs with less than 30% viability from consideration to negate toxicity effects on the CCI. With a CCI cutoff of two standard deviations from the mean, we attained a hit rate of 2.8% with 40 hits. The screen identified both known and novel radiosensitizers belonging to previously unidentified classes. This methodology of cell cycle analysis was confirmed by the more classical flow cytometry assay and a selected hit from the screen was assessed for radiosensitizing ability by clonogenic and γH2AX assays, and in vivo studies. Based on the clonogenic survival fractions, the radiation enhancement ratio was found to be >1 at all doses between 2-6 Gy for the selected drug, with the highest values at 4 and 5 Gy of 4.5. Furthermore, we found two 10 µM doses of the novel radiosensitizer paired with two fractions of 2 Gy was sufficient to significantly decrease 4T1 tumor volume growth in BALB/c mice.

Citation Format: Madeleine R. Landry, Allison N. DuRoss, Eunseo Choi, Antony Jozic, Dylan Nelson, Conroy Sun. Novel high-throughput screen in a breast cancer cell line to identify potent radiosensitizers [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-087.
Abstract PR-003: Radiosensitization by targeting the NPM1/RAD51 axis
Authors: Freeman Michael L. , Traver Geri , Sekhar Konjeti R. , Crooks Peter A.
Published: April 2021

NPM1 is a chaperone involved in base excision, translesion synthesis and homologous recombination (HR). In the presence of DNA DSBs pT199 NPM1 co-localizes with H2AX foci, a consequence of binding to K63-linked ubiquitinated histones that surround DSBs via its pT199 domain comprised of an acidic tract and adjacent ubiquitin interacting motif-like domain (1-3). SUMOlyated K263 NPM1 binds to and promotes Rad51 loading onto resected 3-prime DNA at the DSB. Failure to SUMOlyate K263NPM or inhibition of NPM1 reduces Rad51 filament formation, thus inhibiting HR (4). A major effort is underway to develop DNA damage response inhibitors. The novel chemical entity YTR107 is a 5-((N-benzyl-1H-indol-3-yl) methylene) pyrimidine-2, 4,6(1H,3H,5H) trione developed using forward chemical genetics and structure/function screening (5). Colony formation assays revealed that YTR107 radiosensitized 7 NSCLC lines (dose modifying factors of 1.5). Radiosensitization was NPM1-dependent as YTR107 did not radiosensitize an NPM1 null mouse embryo fibroblast cell line (3). Here we show that YTR107 inhibits radiation-induced NPM1 binding to Rad51, Rad 51 foci formation and repair of DNA DSBs.Tumor initiating cells (TICs) were radiosensitized by YTR107. YTR107 inhibited tumor growth (P = 0.027, 2-way ANOVA) and increased the survival of A549 tumor-bearing mice, determined 70 days after the last treatment. Survival of tumor-bearing mice was 60% for mice treated with YTR107and 2.2 Gy(q.d. x 7) vs 20% for mice treated with 2.2 Gy alone (q.d.x 7). Cox Proportional log rank hazard ratio for irradiated vs unirradiated tumor-bearing mice was 0.24 (P = 0.0034) while the log rank hazard ratio for YTR107 plus irradiation vs unirradiated (± YTR107) tumor-bearing mice was 0.17 (P = 0.0023). Thus, these data provide support for development of YTR107 as a therapeutic radiation sensitizer. Supported in part by R44CA228756.

1.Koike A, Nishikawa H, Wu W, Okada Y, Venkitaraman AR, Ohta T.Cancer Res 2010;70:6746-56 2. Sekhar KR, Benamar M, Venkateswaran A, Sasi S, Penthala NR, Crooks PA, et al. Int J Radiat Oncol Biol Phys 2014;89:1106-14 3. Sekhar KR, Reddy YT, Reddy PN, Crooks PA, Venkateswaran A, McDonald WH, et al. Clin Cancer Res 2011;17:6490-9 4. Xu R, Yu S, Zhu D, Huang X, Xu Y, Lao Y, et al. Nat Commun 2019;10:3812 5. Reddy YT, Sekhar KR, Sasi N, Reddy PN, Freeman ML, Crooks PA. Bioorg Med Chem Lett 2010;20:600-2

Citation Format: Michael L. Freeman, Geri Traver, Konjeti R. Sekhar, Peter A. Crooks. Radiosensitization by targeting the NPM1/RAD51 axis [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PR-003.
Hollow Fiber and Nanofiber Membranes in Bioartificial Liver and Neuronal Tissue Engineering
Authors: Morelli Sabrina , Piscioneri Antonella , Salerno Simona , De Bartolo Loredana
Published: April 2021

To date, the creation of biomimetic devices for the regeneration and repair of injured or diseased tissues and organs remains a crucial challenge in tissue engineering. Membrane technology offers advanced approaches to realize multifunctional tools with permissive environments well-controlled at molecular level for the development of functional tissues and organs. Membranes in fiber configuration with precisely controlled, tunable topography, and physical, biochemical, and mechanical cues, can direct and control the function of different kinds of cells toward the recovery from disorders and injuries. At the same time, fiber tools also provide the potential to model diseases in vitro for investigating specific biological phenomena as well as for drug testing. The purpose of this review is to present an overview of the literature concerning the development of hollow fibers and electrospun fiber membranes used in bioartificial organs, tissue engineered constructs, and in vitro bioreactors. With the aim to highlight the main biomedical applications of fiber-based systems, the first part reviews the fibers for bioartificial liver and liver tissue engineering with special attention to their multifunctional role in the long-term maintenance of specific liver functions and in driving hepatocyte differentiation. The second part reports the fiber-based systems used for neuronal tissue applications including advanced approaches for the creation of novel nerve conduits and in vitro models of brain tissue. Besides presenting recent advances and achievements, this work also delineates existing limitations and highlights emerging possibilities and future prospects in this field.
Association between 10-Year Atherosclerotic Cardiovascular Disease Risk and Vascular Endothelial Function in Patients with Vasospastic Angina
Authors: Park Kyoung-Ha , Park Woo Jung , Kim Hyun-Sook , Jo Sang Ho , Kim Sung-Ai , Choi Hong-Mi , Suh Sang Won
Published: April 2021

Background: Endothelial dysfunction is a predictor of atherosclerotic cardiovascular disease (ASCVD) and plays an important role in vasospastic angina (VA). Objectives: This study evaluated whether flow-mediated dilation (FMD) is also a good marker of 10-year ASCVD risk (10Y-ASCVDR) in patients with VA. Methods: Based on their clinical history and coronary artery diameter stenosis (DS), patients were retrospectively enrolled into VA (DS <50% and positive ergonovine provocation), minor coronary artery disease (mCAD, DS <30%), and significant coronary artery disease (sCAD, DS ≥50%) groups. Endothelial function was evaluated by FMD. Results: Each group contained 50 patients. The 10Y-ASCVDR was significantly higher in the sCAD group than in the VA and mCAD groups (10.86 ± 7.30, 4.71 ± 4.04, and 4.77 ± 4.30, respectively, p < 0.001). The FMD was significantly higher in the mCAD group than in the VA and sCAD groups (6.37 ± 4.25, 3.10 ± 2.23, and 3.07 ± 1.89, respectively, p < 0.001). A significant correlation was found between the FMD and 10Y-ASCVD in the mCAD group (r = −0.622, p < 0.001) and the sCAD group (r = −0.557, p < 0.001) but not in the VA group (r = −0.193, p = 0.179). After adjusting for potential confounders such as BMI, C-reactive protein, maximal coronary stenosis, and brachial-ankle pulse wave velocity, multivariate analysis showed that FMD was independently associated with 10Y-ASCVDR in all patients. However, when looking only at the VA group, FMD did not correlate independently with 10Y-ASCVDR. Conclusions: Unlike mCAD and sCAD, we found no correlation between 10Y-ASCVDR and endothelial function in VA. Thus, our results support that FMD is not a good marker of atherosclerotic cardiovascular risk in VA.
Mechanical and Ablative Minimally Invasive Techniques for Male LUTS due to Benign Prostatic Obstruction: A Systematic Review according to BPH-6 Evaluation
Authors: Cantiello Francesco , Fimognari Deborah , Di Mauro Marina , Crocerossa Fabio , Carbonara Umberto , Ferro Matteo , De Cobelli Ottavio , Lucarelli Giuseppe , De Nunzio Cosimo , Morgia Giuseppe , Damiano Rocco , Autorino Riccardo , Porpiglia Francesco , Russo Giorgio Ivan
Published: April 2021

The treatment of male lower urinary tract symptoms (LUTS) due to benign prostatic obstruction represents one of the major interesting aspects in urological clinical practice. Although transurethral resection of the prostate is still considered the surgical gold standard for treatment of benign prostatic hyperplasia with prostate volume <80 mL, various minimally invasive surgical treatments (MITs) have been developed to overcome the limitations of the “conventional” surgery. To date, there are no validated tools to evaluate the surgical outcomes of MITs; however, in the past, BPH-6 has been used for this purpose. In this systematic review, we evaluated the efficacy and safety of MITs according to BPH-6 score system. We focused our attention on MITs based on mechanical devices (prostatic urethral lift and the temporary implantable nitinol device) and techniques for prostate ablation (image guided robotic waterjet ablation and convective water vapor energy ablation). Evidence shows that MITs are capable of leading to an improvement in LUTS without having an overwhelming impact on complications and are a valid alternative to other treatments in patients who wish to preserve their sexual function or in case of inapplicability of conventional surgery. However, comparative studies between these techniques are still missing.
Swimming Exercise Ameliorates Hypertension-Induced Kidney Dysfunction via Alleviating Renal Interstitial Fibrosis and Apoptosis
Authors: Duan Yong-Chang , Shi Lin , Jin Zheng , Hu Meng , Huang Hao , Yan Tao , Zhang Kun-Ru
Published: April 2021

Background: Hypertensive nephropathy is one of the major causes of ESRD. Exercise has been considered a nonpathological therapy for hypertension and its complications, yet mechanisms remain unclear. We sought to investigate whether periodic swimming could ameliorate hypertension-induced kidney dysfunction and its underlying mechanisms. Methods: Four-week male spontaneously hypertensive rats (SHRs) were randomly divided into the hypertension group (SHR, n = 8) and exercise group (SE, n = 8, 60 min swimming/day, 6 days per week, for 8 weeks). Wistar-Kyoto rats (WKY, n = 8) were served as a sedentary normotensive group. Bodyweight and blood pressure (BP) were recorded weekly. After 8-week sedentary or swimming exercise, lipids profile, BUN, and Cr were measured. The renal interstitial fibrosis was examined by the histopathological analysis using Masson’s trichrome staining and hematoxylin and eosin staining. The kidney cell apoptosis was tested by TUNEL staining. The expressions of critical proteins responsible for the TGF-β1/Smad signaling of fibrosis, that is, TGF-β1, Smad2/3, and Smad7, as well as apoptosis related proteins, Bax and Bcl-2 in kidney cortex tissues were measured. Results: The 8-week swimming exercise reduced BP and bodyweight, lowered concentrations of BUN, and serum Cr, compared with SHR. Exercise remarkably inhibited hypertension-induced tubular degeneration, cellular cluster, and tubular cell swelling as well as glomerular degeneration in the kidney cortical tissues, attenuated renal interstitial fibrosis, and renal cell apoptosis. Moreover, expressions of TGF-β1, Smad2/3, and Bax were higher in the SHR than the WKY, which were significantly suppressed by the exercise. In contrast, hypertension-reduced expressions of Smad7 and Bcl-2 were enhanced by the swimming exercise. Strong correlations were found between kidney function indices, blood lipids, and key protein expressions. Conclusion: Our results demonstrate beneficial effects of the periodic swimming on ameliorating hypertension-induced kidney dysfunction highlighting the potential of swimming exercise as a nonpathological therapy for early prevention of hypertension-caused kidney diseases.
Are Demoralization and Insight Involved in Suicide Risk? An Observational Study on Psychiatric Inpatients
Authors: Berardelli Isabella , Innamorati Marco , Sarubbi Salvatore , Rogante Elena , Erbuto Denise , De Pisa Eleonora , Costanza Alessandra , Del Casale Antonio , Pasquini Massimo , Lester David , Pompili Maurizio
Published: April 2021

Introduction: Several features contribute to determining suicide risk. This study was designed with the aim of evaluating whether insight into illness and demoralization are involved in suicide risk (active suicidal ideation or behavior). Methods: For this purpose, in a sample of 100 adult psychiatric inpatients, we used the Columbia Suicide Severity Rating Scale to assess suicide risk, the Demoralization Scale for demoralization symptoms, and the Insight Scale to assess illness insight. We also investigated several demographic and clinical features, including gender, age, duration of untreated illness, previous suicide attempts, and nonsuicidal self-injurious behavior. Results: The results demonstrated that patients with higher scores on the insight-high dimension had 1.35 greater odds of having a higher suicide risk, and those with lifetime suicide attempts had 7.45 greater odds of having a higher suicide risk. Among the various clinical factors, the study indicated that only nonsuicidal self-harm behaviors in the last 3 months was a risk factor for suicide risk. Conclusions: The results indicated that greater illness insight is involved in suicide risk regardless of demoralization.