Radiation-resistant Cells Research Articles

Role of the p53/miR-34a/SIRT1 Feedback Loop in Metformin-induced Radiosensitivity of Colorectal Cancer Cells.

Metformin induces radiation sensitivity in cancer cells, including colorectal cancer cells; however, the exact molecular mechanisms underlying its radiosensitive effects are not yet known. In this study, we investigated the role of the p53/miR-34a/SIRT1 pathway in the radiosensitivity of colon cancer cells. The study was carried out from 2020 to 2022 at the Qazvin University of Medical Science's Cellular and Molecular Research Center. Two colorectal cancer cell lines (SW480 and SW620) obtained from primary and secondary tumors derived from a single patient were used as the study samples. After subjecting the cells to 50 Gy of radiation, we generated radioresistant cell lines. Resistant cells were treated with 50 μM metformin. Metformin-treated and untreated resistant cells constituted the study groups. The expression levels of miR-34-a and Sirtunin1 (SIRT1) were evaluated using Quantitative Real-time PCR. The rates of cell proliferation and apoptosis were assessed using a Cell Counting Kit-8 (CCK-8) assay and flow cytometry. Western blot analysis was performed to quantify the expression of proteins. For statistical analysis, the Student's ttest was carried out to examine the mean differences between the two groups, and analysis of variance (ANOVA) was used to examine additional groups. Our results showed that the expression of miR-34-a was downregulated (0.29 ± 0.11) in radiation-resistant cancer cells (P <0.001), while the expression of SIRT-1 was upregulated (4.5 ± 0.25) (P <0.001). Metformin increased the radiosensitivity of colon cancer cells in a time- and dose-dependent manner. Treatment with 50 μM metformin after 48h caused decreased cell viability and increased apoptosis in resistant cells. We observed downregulation of SIRT-1 (1.1 ± 0.45) and upregulation of miR-34-a (4.3 ± 1.3) (P <0.001) in metformin-treated cells. In contrast, western blotting results showed the upregulation of acetylated P53 in metformin-treated cells. Metformin function was reversed by SIRT1 inhibitors or by transfection with miR-34-a overexpressing plasmids. Based on these results, one of the radiosensitivity mechanisms of metformin in colorectal cancer is the modulation of the p53/miR-34a/SIRT1 loop.

NF2 loss-of-function and hypoxia drive radiation resistance in grade 2 meningiomas.

World Health Organization Grade 2 meningiomas (G2Ms) often recur and resist therapies. G2Ms with histopathological necrosis have been associated with worse local control (LC) following radiation therapy, but the drivers and biomarkers of radiation resistance in G2Ms remain unknown. We performed genetic sequencing and histopathological analysis of 113 G2Ms and investigated the role of genetic and microenvironmental factors on clonogenic survival following ionizing radiation. We performed transcriptional profiling of our in vitro model and 18 human G2M tumors by bulk RNA sequencing as well as eight G2Ms by single nuclei RNA sequencing. NF2 loss-of-function (LOF) mutations were associated with necrosis in G2Ms (p = .0127). Tumors with NF2 mutation and necrosis had worse post-radiation LC compared to NF2 wildtype tumors without necrosis (p = .035). Under hypoxic conditions, NF2 knockdown increased radiation resistance in vitro (p < .001). Bulk RNA sequencing revealed NF2- and hypoxia-specific changes and a 50-gene set signature specific to radiation resistant, NF2 knockdown and hypoxic cells, which distinguished NF2 mutant/necrotic patient G2Ms by unsupervised clustering. Enrichment analysis revealed downregulation of apoptosis pathway genes and upregulation of proliferation-associated genes and genes normally downregulated after UV radiation exposure in NF2-mutant/necrotic tumor cells, which were validated with functional assays. NF2 LOF in the setting of hypoxia confers radiation resistance through transcriptional programs that reduce apoptosis and promote proliferation. These pathways may identify tumors resistant to radiation and represent therapeutic targets that in the future could improve LC in patients with radiation resistant G2Ms.

B7-H3 CAR-T cell therapy combined with irradiation is effective in targeting bulk and radiation-resistant chordoma cancer cells

BackgroundChordoma is a slow-growing, primary malignant bone tumor that arises from notochordal tissue in the midline of the axial skeleton. Surgical excision with negative margins is the mainstay of treatment,...

The ternary complex of Mn2+, synthetic decapeptide DP1 (DEHGTAVMLK), and orthophosphate is a superb antioxidant

Mn2+ coordinated by orthophosphate (Pi), metabolites, or peptides acts as a superoxide dismutase (SOD), and these Mn antioxidant complexes are universally accumulated in extremely radiation-resistant cell types across the tree of life. This behavior prompted design of decapeptide DP1 (DEHGTAVMLK) as a Mn2+ ligand, and development of a highly potent Mn2+-antioxidant (MDP) containing [Pi] = 25 mM, and [DP1] = 3 mM, the ratio found in the radioresistant bacterium Deinococcus radiodurans, with [Mn2+] = 1 mM. MDP is an exceptional antioxidant, both in vitro and in vivo, and has reinvigorated the development of radiation-inactivated whole-cell vaccines. This study investigates the nature of the active Mn2+ complex in MDP. We measure the affinity of DP1 for the substitutionally labile Mn2+ ion using isothermal-titration calorimetry (ITC) and use changes in the Mn2+ solution EPR spectrum to determine affinities of Mn2+ for DP1 and for Pi, and to monitor Mn2+ ligation while titrated with the fixed Pi/DP1 ratio of MDP, 25/3, using ENDOR/ESEEM to characterize DP1 ligation to Mn2+. In parallel, 1H NMR of DP1 was used to monitor binding interactions between Pi and DP1, and DP1 binding to the diamagnetic Ca2+. We report: i) DP1 forms an extremely weak, dynamic Mn2+ complex (Ka ≈ 40 M-1) ii) Mn2+ binds Pi much more strongly (Ka ≈ 390 M-1) as shown previously, but iii) DP1 and Pi jointly bind to Mn2+ in MDP to form a ternary Mn2+ (Pi) (DP1) complex with greater formation-constant than Pi alone (Kaapp ≈ 670 M-1). It is this ternary complex that is the superb antioxidant in MDP.

Enhancing Radiation-induced Reactive Oxygen Species Generation Through Mitochondrial Transplantation in Human Glioblastoma.

Glioblastoma (GBM) is the most aggressive primary brain malignancy in adults, with high recurrence rates and resistance to standard therapies. This study explores mitochondrial transplantation as a novel method to enhance the radiobiological effect (RBE) of ionizing radiation (IR) by increasing mitochondrial density in GBM cells, potentially boosting reactive oxygen species (ROS) production and promoting radiation-induced cell death. Using cell-penetrating peptides (CPPs), mitochondria were transplanted into GBM cell lines U3020 and U3035. Transplanted mitochondria were successfully incorporated into recipient cells, increasing mitochondrial density significantly. Mitochondrial chimeric cells demonstrated enhanced ROS generation post-irradiation, as evidenced by increased electron paramagnetic resonance (EPR) signal intensity and fluorescent ROS assays. The transplanted mitochondria retained functionality and viability for up to 14 days, with mitochondrial DNA (mtDNA) sequencing confirming high transfection and retention rates. Notably, mitochondrial transplantation was feasible in radiation-resistant GBM cells, suggesting potential clinical applicability. These findings support mitochondrial transplantation as a promising strategy to overcome therapeutic resistance in GBM by amplifying ROS-mediated cytotoxicity, warranting further investigation into its efficacy and mechanisms in vivo .

RRFERV stabilizes TEAD1 expression to mediate nasopharyngeal cancer radiation resistance rendering tumor cells vulnerable to ferroptosis.

Long noncoding RNAs (lncRNAs) regulate various essential biological processes, including cell proliferation, differentiation, apoptosis, migration, and invasion. However, in nasopharyngeal carcinoma (NPC), the clinical significance and mechanisms of lncRNAs in malignant progression are unknown. RNA sequencing and bioinformatic analysis were used to determine the potential function of RRFERV (radiation-resistant but ferroptosis vulnerable), and its biological effects were investigated using in vitro and in vivo experiments. Western blotting, quantitative real-time reverse transcription PCR, RNA immunoprecipitation (RIP) assays, and flow cytometry detected RRFERV expression. Ferroptosis and lipid peroxidation were added to evaluate the relationship between it and radiotherapy resistance. LncRNA-RRFERV was both highly expressed in NPC tissues and radiation-resistant cells. RRFERV is associated with poor clinical outcomes of NPC patients and stabilizes TEAD1 by competitive binding with microRNA-615-5p and microRNA-1293. RRFERV-TEAD1 signaling axis leads to malignant progression and radiotherapy resistance of NPC. Furthermore, we observed that NPC radiotherapy resistance cells exist in a fragile oxidative stress equilibrium, which makes them more sensitive to ferroptosis inducers. Surprisingly, we found that RRFERV-TEAD1 signaling axis also plays a key role in mediating the lipid peroxidation levels of NPC radiotherapy resistance cells through transcriptional activation of ACSL4/TFRC. RRFERV serves as an independent prognostic factor in NPC. During the malignant progression of NPC caused by high expression of RRFERV, ferroptosis can be induced to effectively kill cancer cells and reverse the radiotherapy resistance of NPC cells, suggesting a potential treatment approach for recurrent and refractory NPC.

Targeting MGST1 Makes Non-Small Cell Lung Cancer Cells Sensitive to Radiotherapy by Epigenetically Enhancing ALOX15-Mediated Ferroptosis.

Ferroptosis is closely related to radiotherapy resistance in multiple can-cers. Herein, the role of microsomal glutathione S-transferase 1 (MGST1) in regulating ferropto-sis and radiotherapy resistance in non-small cell lung cancer (NSCLC) was investigated. Radiation-resistant NSCLC cells (NCI-1299-IR and HCC827-IR cells) were estab-lished. After exposure to X-ray, cell proliferation and survival were assessed by colony formation assay and CCK-8 assay, and lipid ROS level was examined by the fluorophore BODIPY™ 581/591 C11. MDA, GSH, and Fe2+ levels were measured by ELISA kits. The molecular interac-tion was analyzed using ChIP and MSP assays. Our results showed that RSL3 treatment greatly enhanced the radiotherapy sensitivity of NCI-1299-IR and HCC827-IR cells. It was subsequently revealed that MGST1 was highly ex-pressed in NCI-1299-IR and HCC827-IR cells than its parent cells, and silencing of MGST1 re-duced radioresistance of NCI-1299-IR and HCC827-IR cells by facilitating ferroptosis. Mechanis-tically, MGST1 knockdown greatly reduced HO-1 and DNMT1/3A protein levels, leading to re-duced DNA methylation on the ALOX15 promoter region, thereby epigenetically upregulating ALOX15 expression. As expected, the promoting effects of MGST1 silencing on radiosensitivity and ferroptosis in radiation-resistant NSCLC cells were strikingly eliminated by ALOX15 knock-down. MGST1 knockdown epigenetically enhanced radiotherapy sensitivity of NCSLC cells by promoting ALOX15-mediated ferroptosis through regulating the HO-1/DNMT1 pathway.

Coumarin-Based Aldo-Keto Reductase Family 1C (AKR1C) 2 and 3 Inhibitors.

A series of 7-substituted coumarin derivatives have been characterized as pan-aldo-keto reductase family 1C (AKR1C) inhibitors. The AKR1C family of enzymes are overexpressed in numerous cancers where they are involved in drug resistance development. 7-hydroxy coumarin ethyl esters and their corresponding amides have high potency for AKR1C3 and AKR1C2 inhibition. Coumarin amide 3 a possessed IC50 values of 50 nM and 90 nM for AKR1C3 and AKR1C2, respectively, and exhibits 'drug-like' metabolic stability and half-life in human and mouse liver microsomes and plasma. Compound 3 a was employed as a chemical tool to determine pan-AKR1C2/3 inhibition effects both as a radiation sensitizer and as a potentiator of chemotherapy cytotoxicity. In contrast to previously reported pan-AKR1C inhibitors, 3 a demonstrated no radiation sensitization effect in a radiation-resistant prostate cancer cell line model. Pan-AKR1C inhibition also did not potentiate the in vitro cytotoxicity of ABT-737, daunorubicin or dexamethasone, in two patient-derived T-cell ALL and pre-B-cell ALL cell lines. In contrast, a highly selective AKR1C3 inhibitor, compound K90, enhanced the cytotoxicity of both ABT-737 and daunorubicin in the T-cell ALL cell line model. Thus, the inhibitory profile required to enhance chemotherapeutic cytotoxicity in leukemia may be AKR1C isoform and drug specific.

Abstract A011: Enhanced Radiosensitivity of Pancreatic Cancer Achieved through Inhibition of Cyclin-Dependent Kinase 1

Abstract Introduction: One of the major challenges in treating Pancreatic Ductal Adenocarcinoma (PDAC) is overcoming radioresistance. This study investigates the targeting of Cyclin-dependent kinase-1 (CDK1) through both genetic and pharmaceutical inhibition as a strategy to increase the radiosensitivity of PDAC cells. Methods: We conducted mass spectrometry and phosphoproteomics analyses to compare engineered radiation-resistant PDAC cell lines (MIA PaCa-2 and PANC-1) with their parental controls. Additionally, we examined the TCGA PDAC database to correlate clinical outcomes, such as overall survival (OS), with CDK1 mRNA expression levels in PDAC patients. Furthermore, we developed a microRNA-based TET-on inducible shRNA to specifically inhibit CDK1 expression in PDAC cell lines. In an orthotopic PDAC model, we evaluated the radiation sensitivity of PDAC tumors with or without doxycycline treatment. We also employed a selective CDK1 inhibitor, RO-3306, to target CDK1 activation, followed by in vitro experiments using immunoblotting, immunocytochemistry, and clonogenic assays. Results: Our phosphoproteomics analysis revealed a significant increase in phospho-CDK1 (Tyr15) levels in the radiation-resistant cell lines. High CDK1 expression was associated with poorer OS in PDAC patients. Additionally, we observed heightened CDK1 phosphorylation at the threonine tyrosine 14 (Tyr14) residue following radiation exposure. Through our in vivo and in vitro experiments, we demonstrated that CDK1 inhibition, in conjunction with radiation therapy, delayed tumor growth and enhanced radiosensitivity in PDAC cells. Treatment with RO-3306 caused a substantial shift of cells into the G2/M phase and disrupted DNA repair post-radiation exposure, further enhancing radiosensitivity. Conclusion: Our findings underscore the critical role of CDK1 in PDAC radioresistance. Targeting CDK1 in combination with radiotherapy shows promise for future exploration as a potential treatment strategy in PDAC. Citation Format: Stetson Van Matre, Saaimatul Huq, Lokesh Akana, Oscar Zuniga, Henrique Rodrigues, Adam Wolfe. Enhanced Radiosensitivity of Pancreatic Cancer Achieved through Inhibition of Cyclin-Dependent Kinase 1 [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A011.

Enhanced radiosensitivity of pancreatic cancer achieved through inhibition of Cyclin-dependent kinase 1

Background and purposeOvercoming radioresistance is a critical challenge in pancreatic ductal adenocarcinoma (PDAC). Our study investigates the targeting of Cyclin-dependent kinase-1 (CDK1) through genetic and pharmaceutical inhibition to radiosensitize PDAC cells. Materials and MethodsMass spectrometry and phosphoproteomics were used to analyze engineered radiation-resistant PDAC cell lines (MIA PaCa-2 and PANC-1) compared to parental controls. The TCGA PDAC database was queried for clinical outcomes and patients were dichotomized based on the median CDK1 mRNA expression. We generated a microRNA-based TET-on inducible shRNA to inhibit CDK1 expression in two PDAC cell lines. We used an orthotopic model of PDAC to test the radiation sensitivity of PDAC tumors with or without doxycycline treatment. We targeted CDK1 activation with a selective CDK1 inhibitor, RO-3306, followed by in vitro experiments employing immunoblotting, immunocytochemistry, and clonogenic assays. ResultsPhosphoproteomics analysis revealed that phospho-CDK1 (Tyr15) was significantly elevated in the resistant clones. We found that high CDK1 expression was associated with worse OS in PDAC patients. Radiation exposure increased CDK1 phosphorylation. In MIA PaCa-2 and PANC-1 cells, CDK1 inhibition synergized with radiation therapy to delay tumor growth in vivo. CDK1 inhibition via. RO-3306 resulted in a significant shift of cells into the G2/M phase and disrupted DNA repair after radiation exposure. In vitro, pre-treatment with RO-3306 led to enhanced radiosensitivity of PDAC cells. ConclusionCDK1 plays a crucial role in PDAC radioresistance. Targeting CDK1 with radiotherapy holds promise for further investigation in PDAC treatment.

Radiation-induced YAP/TEAD4 binding confers non-small cell lung cancer radioresistance via promoting NRP1 transcription

Despite the importance of radiation therapy as a non-surgical treatment for non-small cell lung cancer (NSCLC), radiation resistance has always been a concern, due to poor patient response and prognosis. Therefore, it is crucial to uncover novel targets to enhance radiotherapy and investigate the mechanisms underlying radiation resistance. Previously, we demonstrated that NRP1 was connected to radiation resistance in NSCLC cells. In the present study, bioinformatics analysis of constructed radiation-resistant A549 and H1299 cell models revealed that transcription coactivator YAP is a significant factor in cell proliferation and metastasis. However, there has been no evidence linking YAP and NRP1 to date. In this research, we have observed that YAP contributes to radiation resistance in NSCLC cells by stimulating cell proliferation, migration, and invasion. Mechanistically, YAP dephosphorylation after NSCLC cell radiation. YAP acts as a transcription co-activator by binding to the transcription factor TEAD4, facilitating TEAD4 to bind to the NRP1 promoter region and thereby increasing NRP1 expression. NRP1 has been identified as a new target gene for YAP/TEAD4. Notably, when inhibiting YAP binds to TEAD4, it inhibits NRP1 expression, and Rescue experiments show that YAP/TEAD4 influences NRP1 to regulate cell proliferation, metastasis and leading to radiation resistance generation. According to these results, YAP/TEAD4/NRP1 is a significant mechanism for radioresistance and can be utilized as a target for enhancing radiotherapy efficacy.

Modulation of epithelial-mesenchymal transition by gemcitabine: Targeting ionizing radiation-induced cellular senescence in lung cancer cell

Ionizing radiation, a standard therapeutic approach for lung cancer, often leads to cellular senescence and the induction of epithelial-mesenchymal transition (EMT), posing significant challenges in treatment efficacy and cancer progression. Overcoming these obstacles is crucial for enhancing therapeutic outcomes in lung cancer management. This study investigates the effects of ionizing radiation and gemcitabine on lung cancer cells, with a focus on induced senescence, EMT, and apoptosis. Human-derived A549, PC-9, and mouse-derived Lewis lung carcinoma cells exposed to 10 Gy X-ray irradiation exhibited senescence, as indicated by morphological changes, β-galactosidase staining, and cell cycle arrest through the p53-p21 pathway. Ionizing radiation also promoted EMT via TGFβ/SMAD signaling, evidenced by increased TGFβ1 levels, altered EMT marker expressions, and enhanced cell migration. Gemcitabine, a first-line lung cancer treatment, was shown to enhance apoptosis in senescent cells caused by radiation. It inhibited cell proliferation, induced mitochondrial damage, and triggered caspase-mediated apoptosis, thus mitigating EMT in vitro. Furthermore, in vivo studies using a lung cancer mouse model revealed that gemcitabine, combined with radiation, significantly reduced tumor volume and weight, extended survival, and suppressed malignancy indices in irradiated tumors. Collectively, these findings demonstrate that gemcitabine enhances the therapeutic efficacy against radiation-resistant lung cancer cells, both by inducing apoptosis in senescent cells and inhibiting EMT, offering potential improvements in lung cancer treatment strategies.

Abstract 1109: LINC01770 stabilizes TEAD1 expression to mediates nasopharyngeal cancer radiation resistance rendering tumor cells vulnerable to ferroptosis

Abstract Background: Long noncoding RNAs (lncRNAs) regulate various essential biological processes, including cell proliferation, differentiation, apoptosis, migration, and invasion. However, in nasopharyngeal carcinoma (NPC), the clinical significance and mechanisms of lncRNAs in malignant progression are unknown. Methods: LINC01770 expression was determined using quantitative real-time reverse transcription PCR, and its prognostic value was evaluated using Kaplan-Meier survival analysis. RNA sequencing and bioinformatic analysis were used to determine the potential function of LINC01770, and its biological effects were investigated using in vitro and in vivo experiments. Mass spectrometry-coupled RNA pull-down assays and western blotting identified LINC01770 interacting proteins, followed by confirmation using RNA immunoprecipitation (RIP) assays. Ferroptosis and lipid peroxidation were detected using flow cytometry. Results: LINC01770 was overexpressed in NPC tissues according to microarray screening. Patients with NPC showing high LINC01770 expression experienced shorter survival and worse prognosis. In vitro and in vivo experiments suggested that knockdown of LINC01770 expression significantly inhibited the proliferation, migration, and invasion of NPC cells. Sequencing and functional complementation experiments showed that LINC01770 regulates the proliferation and metastasis of NPC through TEA domain transcription factor 1 (TEAD1). Meanwhile, RIP and PCR experiments suggested that LINC01770 and TEAD1 were common targets of microRNAs miR-615-5p and miR-1293. Overexpression of LINC01770 promoted ferroptosis in vitro and in vivo through the TEAD1/Acyl-CoA synthetase long chain family member 4 (ACSL4)/transferrin receptor (TFRC) pathway. Conclusions: LINC01770 is a prognostic biomarker for NPC and participates in the regulation of TEAD1 signaling pathway through competitive binding to miRNA-615-5p and miRNA-1293, resulting in NPC metastasis and progression. Radiation resistant cells are in a delicate balance between lipid peroxidation and increased vulnerability to ferroptosis, suggesting that ferroptosis could be used to kill NPC cells and reverse their radiotherapy resistance during the malignant progression of NPC caused by high expression of LINC01770. Thus, inducing ferroptosis could be used to treat recurrent and refractory NPC. Citation Format: Qingqing Xu, Ciming Sun, Suixian Zhang, Xuan Li, Lei Chen, Ming Chen. LINC01770 stabilizes TEAD1 expression to mediates nasopharyngeal cancer radiation resistance rendering tumor cells vulnerable to ferroptosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1109.

Abstract 3930: The therapeutic implications of consensus genomic subtypes of gastric adenocarcinoma

Abstract Background: Gastric adenocarcinoma (GAC) is heterogeneous lethal disease in genomic and clinical level. Although the clinical relevance of genomic and molecular subtypes of GAC has been demonstrated, differences in classification methods have made it difficult to use these findings in clinical applications. We aim to examine a consensus of genomic subtypes and correlate them with clinical outcomes. Method: We collected genomic data from 2527 GAC tumors and divided the data into discovery (n = 1427) and validation sets (n = 1100). A cluster of clusters approach (COCA) was used to find consensus subtypes of gastric tumors. We constructed the GAC predictor of the integrated consensus subtype with 120 genes (GPICS120) and applied it to the validation data set in order to validate the clinical significance of the new subtypes. By analyzing genomic and proteomic data we evaluated each subtype's potential response rate to standard and experimental treatments such radiation therapy, targeted therapy, and immunotherapy and further validated their functional significance in cell line models. Results: We identified 6 clinically and molecularly distinct genomic consensus subtypes (CGSs) by integrating 8 previously established genomic subtypes. CGS1 is characterized by worst prognosis, remarkably high stem cell characteristics, high IGF1 expression, and low genomic alterations. CGS2 showed canonical epithelial gene expression patterns. CGS3 and CGS4 are characterized by high copy number alterations and low immune activity. CGS5 has highest mutation burden and moderately elevated immune activity that is characteristics of MSI-high tumors. The majority of CGS6 tumors have extremely high methylation, high immune activity, and are EBV-positive. The most intriguing finding is that CGS1 is the most responsive to immunotherapy whereas CGS3 is significantly associated with benefit of chemoradiation therapy due to high basal level of ferroptosis. Furthermore, we showed that ferroptosis inducer statin sensitized radiation-resistant GAC cells to ionizing radiation, suggesting that statin can be used to enhance the efficacy of chemoradiation in GAC and it would warrant further investigation in preclinical models. Conclusion: Consensus subtype is robust classification system and can serve as the basis for future clinical trials as well as pre-clinical research into targeted subtype-based therapies. Citation Format: Yun Seong Jeong, Young-Gyu Eun, Sung Hwan Lee, Sang-Hee Kang, Sun Young Yim, Eui Hyun Kim, Joo Kyung Noh, Bo Hwa Sohn, Ju-Seog Lee. The therapeutic implications of consensus genomic subtypes of gastric adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3930.

CLEC3B inhibits proliferation and radioresistance and induces apoptosis in BT549 breast cancer cells

Among all breast cancer subtypes, triple-negative breast cancer (TNBC) has the worst prognosis due to its resistance to treatment, including radiotherapy. The purpose of this study was to screen and validate potential targets related to radioresistance in TNBC. First, a radiation-resistant TNBC cell model, was generated using BT549 cells through fractionated radiation (30 Gy in total, 10 fractions). Then, mRNA sequencing was used to screen potential target genes related to radioresistance. Furthermore, bioinformatics, proteomics and genomics methods were used to screen and validate the key target genes. The results showed that BT549 cells that had undergone fractionated radiation, namely, BT549R cells, had greater proliferation and radioresistance and a lower apoptosis rate than parental BT549 cells. C-type lectin domain family 3 member B (CLEC3B) was identified as a potential key target gene related to radioresistance. The expression of CLEC3B was closely related to the radioresistance of breast cancer and the survival of breast cancer patients. Downregulation of CLEC3B increased cell viability and radioresistance and reduced apoptosis in BT549R cells, which could be reversed by dihydroartemisinin (DHA). The overexpression of CLEC3B with or without DHA treatment inhibited the activity of the PI3K/AKT signaling pathway. DHA increased the expression of CLEC3B in a concentration-dependent manner. In summary, our study illustrated that the downregulation of CLEC3B increased radioresistance in BT549 breast cancer cells and that this effect could be reversed by DHA.

Small molecule inhibitor azd1480 reverses radiotherapy resistance in NSCLC by targeting JAK2/STAT3 pathway

Purpose: To investigate the effect of small molecule inhibitor AZD1480 on radiotherapy resistance in non-small cell lung cancer (NSCLC), and the involvement of Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway in the process.&#x0D; Methods: Radiation-resistant cell lines A549-20F, A549-30F, A549-40F and H460, H46040F, H460- 40F, and H460-40F were established, and expressions of proteins related to JAK/STAT pathway, mitogen-activated protein (MAPK) pathway and transforming growth factor-β (TGF- β) were assayed. The JAK2V617FH460 overexpression cell line and JAK2H460 cell line were established, and expressions of ATGL and CPT1A were compared. The H460 cells and H460-40F cells were treated with JAK2 small molecule inhibitor AZD1480, and the expressions of ATGL, CPT1A and JAK2/STAT3 pathway-related proteins were compared. The survival and proliferation of cell lines were also compared. &#x0D; Results: The JAK/STAT pathway was significantly enriched, and MAPK and TGF-β were up-regulated. In H460 cells, JAK2/STAT3 route was obvious, suggesting that radiotherapy activated JAK2/STAT3 pathway in NSCLC cells. Significant down-regulations of p- JAK2Y1007, JAK2, p-STAT3s727, STAT3, ATGL and CPT1A proteins expressions were seen in H460 + AZD1480 group, relative to H460 group, but protein levels of p-JAK2Y1007, JAK2, p-STAT3s727, STAT3, ATGL and CPT1A were significantly lower in H460-40F + AZD1480 group than in H460-40F group (p &lt; 0.05). The survival and proliferation rates were significantly lower in A549 + AZD1480 group than in A549 and A549-40F groups (p &lt; 0.05).&#x0D; Conclusion: Radiotherapy up-regulates the expressions of ATGL and CPT1A in NSCLC cells by activating the JAK2/STAT3 pathway, while AZD1480, a small molecule inhibitor, reverses the radiation resistance of NSCLC by targeting JAK2/STAT3 pathway and key enzymes of lipid metabolism. Therefore, azd1480 may enhance clinical treatment efficacy in NSCLC patients by reducing radiation resistance.

A robust radiation resistant SRAM cell for space and military applications

Many charged particles in space, including α-particles, neutrons, heavy ions, electrons, and photons, wreak havoc on the stability and reliability of memory circuits. In addition, these high-energy particles produce an ion track within the memory chip, which disrupts the storage bit. Standard 6T SRAM cannot withstand this upset condition. This paper presents a novel RRS-14T radiation-resistant SRAM memory cell with redundant nodes and a polar design to address the soft error issue. The performance of the proposed RRS-14T memory cell is compared to the performance of existing radiation-resistant memory cells, such as RHS-14T, RHMC-12T, NRHC-14T, QCCS-12T, HRRT-13T, and RHBD-13T. The RRS-14T cell protects against single and multiple-node disruptions. The read stability of the proposed RRS-14T memory cell is 2.83x/ 1.5x/ 2.10x/ 1.34x/ 3.38x/ 1.68x greater than the existing RHS-14T/ RHMC-12T/ NRHC-14T/ QCCS-12T/ HRRT-13T/ RHBD-13T memory cells. Moreover, 1.08x/ 1.27x/ 1.06x/ 1.05x/ 1.16x/ 1.07x larger write trip voltage than RHS-14T/ RHMC-12T/ NRHC-14T/ QCCS-12T/ HRRT-13T/ RHBD-13T memory cells. In addition, the write access time, hold power, and critical charge are enhanced when the supply voltage is at 1 V.

MiR-141-3p Enhanced Radiosensitivity of CRC Cells.

Colorectal cancer (CRC) is recognized as one of the frequently diagnosed malignancies, and numerous microRNAs (miRs) are identified to be active in CRC. This work aimed to clarify the effect of miR-141-3p on the radiosensitivity of CRC cells. Firstly, CRC cell lines were cultured and applied to construct radiation-resistant CRC cells via X-ray treatment. The expression levels of miR-141-3p and long non-coding RNA DLX6 antisense RNA 1 (lncRNA DLX6-AS1) in CRC cells were measured using real-time quantitative polymerase chain reaction. After transfection with miR-141-3p mimics and 24 h treatment with 6- MV X-ray (0, 2, 4, 6 Gy), the survival fraction (SF) and the colony formation ability of CRC cells were determined using the cell counting kit-8 and colony formation methods. The interactions between miR-141-3p and DLX6-AS1 were analyzed using the dual-luciferase assay. The impact of miR-141-3p on DLX6-AS1 stability was detected after adding actinomycin-D. The role of DLX6- AS1 in the radiosensitivity of CRC cells was explored by transfecting oe-DLX6-AS1 into radiation- resistant CRC cells overexpressing miR-141-3p. The relative expression levels of miR-141-3p were downregulated in CRC cells and further declined in radiation-resistant cells. Upregulation of miR-141-3p relative expression reduced SF and the colony formation ability while amplifying the radiosensitivity of radiation-resistant CRC cells. miR-141-3p directly bound to DLX6-AS1 to reduce DLX6-AS1 stability, and therefore downregulated DLX6-AS1 expression. DLX6-AS1 overexpression counteracted the role of miR- 141-3p overexpression in amplifying the radiosensitivity of radiation-resistant CRC cells. miR-141-3p binding to DLX6-AS1 significantly decreased DLX6-AS1 stability and expression, promoting the radiosensitivity of CRC cells.

Влияние ионизирующего излучения на активность антиоксидантных ферментов штамма Escherichia coli «ПЛ-6» при многократном облучении

The article presents the analysis of enzymatic activity of Escherichia coli “PL-6” cells following multiple gamma irradiation with increasing doses. For irradiation the stationary gamma ray unit “Researcher” (Co-60) with the dose rate of 36.7 Gy/min was used. Radiation doses to the bacterial cells increased from 3.5 to 10 kGy in 0.5 kGy increment, and from 10 to 30 kGy in 5 kGy increment. Unirradiated suspended bacterial cells were used as control. The irradiated cells enzymatic activity was estimated with the spectrophotometric method on the "MultiSkan Go" device (Thermo Fisher Scientific, Finland). The results of the study demonstrate the increase in the E. coli ”PL-6” cells radioresistance caused by gamma irradiation of the cells with gradually increased doses. Exposure of the bacteria to a higher gamma radiation dose caused decrease in the number of viable cells from 10Е+9 CFU/ml in the control culture sample to 10Е+2 CFU/ml after irradiation at a dose of 30 kGy. The most radiation-resistant cells were selected from cells undergone successive multiple irradiation with constantly increasing dose of ionizing radiation. The enzymes of the antioxidant system in irradiated cells exhibit increased specific activity as compared to the enzymes in control, unirradiated, cells. The activity of enzymes increases with an increase in the radiation dose. Catalase activity increased after multiple irradiation by 5 times and peroxidase activity increased by 4 times. To compare the results in the groups, the Student's t-test was applied at p&lt;0.05.

Radiation resistant chalcopyrite CIGS solar cells: proton damage shielding with Cs treatment and defect healing via heat-light soaking

Cu(In, Ga)Se2 (CIGS) solar cells are recognized as next-generation space technology due to their flexibility, lightweight nature, and excellent environmental stability.