Search

The disruption of polynucleotide kinase/phosphatase (PNKP) in colorectal cancer (CRC) cells deficient in phosphatase and tensin homolog (PTEN) is expected to lead to the loss of cell viability by a process known as synthetic lethality. In previous studies, we have reported on the encapsulation of a novel inhibitor of PNKP, namely, A83B4C63, in polymeric micelles and its activity in slowing the growth of PTEN-deficient CRC cells as well as subcutaneous xenografts. In this study, to enhance drug delivery and specificity to CRC tumors, the surface of polymeric micelles carrying A83B4C63 was modified with GE11, a peptide targeting epidermal growth factor receptor (EGFR) overexpressed in about 70% of CRC tumors. Using molecular dynamics (MD) simulations, we assessed the binding site and affinity of GE11 for EGFR. The GE11-modified micelles, tagged with a near-infrared fluorophore, showed enhanced internalization by EGFR-overexpressing CRC cells

Background: Gold nanorods (GNRs) are very promising agents with multiple applications in medicine and biology. However, the cytotoxic effects of GNRs have not been fully explored. Objective: Therefore, the main objective of this study was to determine the selective cytotoxic effect of GNRs towards several human tumor cell lines. Methods: To address this issue, three sizes of GNRs (10-nm, 25-nm, and 50-nm) were tested against two human tumor cell lines, namely, human hepatoma HepG2 and human prostate PC3 cancer cells. As GNRs are usually stored in soft tissues inside living bodies, we also tested the effect of GNRs on murine splenocyte viability. To determine if the GNRs displayed selective cytotoxicity towards cancer cells, active GNRs with the size showing the least cytotoxicity to splenocytes were then tested against a panel of 11 human tumor cell lines and two human non-tumor cell lines. Results: Our results showed that the most cytotoxic size of GNRs is 10-nm, followed by the 25-nm GNRs, while the 50-nm GNRs did not show a significant effect. In addition, the 25-nm GNRs were the least cytotoxic to splenocytes when tested for 24 and 48 h. These GNRs showed a selective cytotoxic effect to prostate cancer PC3 cells with median inhibitory concentration (IC50) = 8.3 + 0.37 μM, myeloblastic leukemia HL60 cells (IC50 = 19.7 + 0.89 μM), cervical cancer HeLa cells (IC50 = 24.6 + 0.37 μM), renal adenocarcinoma 786.0 cells (IC50 = 27.34 + 0.6 μM), and hepatoma HepG2 cells (IC50 = 27.79 + 0.03 μM) when compared to the effect on the non-tumor human cells; skin fibroblast BJ cell line (IC50 = 40.13 + 0.7 μM) or epithelial breast MCF10A cells (IC50 = 33.2 + 0.89 μM). High selectivity indices (SIs) were observed in GNRs-treated PC3 and HL60 cells with values ranging from 1.69 to 4.83, whereas moderate SIs were observed in GNRs-treated HeLa, 786.0, and HepG2 cells with values ranging from 1.19 to 1.63. Other cells did not show a similar selective effect, including human laryngeal HEp2 cells, colon HCT116, metastatic renal adenocarcinoma ACHN cells, and human breast cancer cells (MCF7, MDA-MB-231, and MDA-MB-468 cells). The effect of GNRs was confirmed using the colony formation assay and the effect was found to be cell cycle-specific. Finally, it was shown that laser treatment could potentiate the cytotoxic effect of the 25-nm GNRs. Conclusion: GNRs are selective cytotoxic agents and they have the potential to act as candidate anticancer agents.

A recent screen of 6,961 siRNAs to discover possible synthetic lethal partners of the DNA repair protein polynucleotide kinase/phosphatase (PNKP) led to the identification of the potent tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN). Here, we have confirmed the PNKP/PTEN synthetic lethal partnership in a variety of different cell lines including the PC3 prostate cancer cell line, which is naturally deficient in PTEN. We provide evidence that codepletion of PTEN and PNKP induces apoptosis. In HCT116 colon cancer cells, the loss of PTEN is accompanied by an increased background level of DNA double-strand breaks, which accumulate in the presence of an inhibitor of PNKP DNA 3′-phosphatase activity. Complementation of PC3 cells with several well-characterized mutated PTEN cDNAs indicated that the critical function of PTEN required to prevent toxicity induced by an inhibitor of PNKP is most likely associated with its cytoplasmic lipid phosphatase activity. Finally, we show that modest inhibition of PNKP in a PTEN knockout background enhances cellular radiosensitivity, suggesting that such a “synthetic sickness” approach involving the combination of PNKP inhibition with radiotherapy may be applicable to PTEN-deficient tumors. Mol Cancer Ther; 12(10); 2135–44. ©2013 AACR.

PDF file, 110K, Supplementary Figure S1. Determination of ROS production in PTEN+/+ and PTEN-/- cells; Supplementary Figure S2. Cell proliferation assay of the PC3 derived cell lines.

A genetic screen using a library of 6,961 siRNAs led to the identification of SHP-1 (PTPN6), a tumor suppressor frequently mutated in malignant lymphomas, leukemias, and prostate cancer, as a potential synthetic lethal partner of the DNA repair protein polynucleotide kinase/phosphatase (PNKP). After confirming the partnership with SHP-1, we observed that codepletion of PNKP and SHP-1 induced apoptosis. A T-cell lymphoma cell line that is SHP-1 deficient (Karpas 299) was shown to be sensitive to a chemical inhibitor of PNKP, but resistance was restored by expression of wild-type SHP-1 in these cells. We determined that while SHP-1 depletion does not significantly impact DNA strand-break repair, it does amplify the level of reactive oxygen species (ROS) and elevate endogenous DNA damage. The ROS scavenger WR1065 afforded protection to SHP-1–depleted cells treated with the PNKP inhibitor. We propose that codisruption of SHP-1 and PNKP leads to an increase in DNA damage that escapes repair, resulting in the accumulation of cytotoxic double-strand breaks and induction of apoptosis. This supports an alternative paradigm for synthetic lethal partnerships that could be exploited therapeutically. Cancer Res; 72(22); 5934–44. ©2012 AACR.

Supplementary Table 1 from Pathways of Proliferation and Antiapoptosis Driven in Breast Cancer Stem Cells by Stem Cell Protein Piwil2

PDF file - 2MB

Supplementary Table 2 from Pathways of Proliferation and Antiapoptosis Driven in Breast Cancer Stem Cells by Stem Cell Protein Piwil2

Supplementary Figures 1-7 from Pathways of Proliferation and Antiapoptosis Driven in Breast Cancer Stem Cells by Stem Cell Protein Piwil2

Supplementary Figure Legends 1-7 from Pathways of Proliferation and Antiapoptosis Driven in Breast Cancer Stem Cells by Stem Cell Protein Piwil2

The ERCC1–XPF 5′–3′ DNA endonuclease complex is involved in the nucleotide excision repair pathway and in the DNA inter-strand crosslink repair pathway, two key mechanisms modulating the activity of chemotherapeutic alkylating agents in cancer cells. Inhibitors of the interaction between ERCC1 and XPF can be used to sensitize cancer cells to such drugs. We tested recently synthesized new generation inhibitors of this interaction and evaluated their capacity to sensitize cancer cells to the genotoxic activity of agents in synergy studies, as well as their capacity to inhibit the protein–protein interaction in cancer cells using proximity ligation assay. Compound B9 showed the best activity being synergistic with cisplatin and mitomycin C in both colon and lung cancer cells. Also, B9 abolished the interaction between ERCC1 and XPF in cancer cells as shown by proximity ligation assay. Results of different compounds correlated with values from our previously obtained in silico predictions. Our results confirm the feasibility of the approach of targeting the protein–protein interaction between ERCC1 and XPF to sensitize cancer cells to alkylating agents, thanks to the improved binding affinity of the newly synthesized compounds.

The heterodimer of DNA excision repair protein ERCC-1 and DNA repair endonuclease XPF (ERCC1-XPF) is a 5'-3' structure-specific endonuclease essential for the nucleotide excision repair (NER) pathway, and it is also involved in other DNA repair pathways. In cancer cells, ERCC1-XPF plays a central role in repairing DNA damage induced by chemotherapeutics including platinum-based and cross-linking agents; thus, its inhibition is a promising strategy to enhance the effect of these therapies. In this study, we rationally modified the structure of F06, a small molecule inhibitor of the ERCC1-XPF interaction (Molecular Pharmacology, 84, 2013 and 12), to improve its binding to the target. We followed a multi-step computational approach to investigate potential modification sites of F06, rationally design and rank a library of analogues, and identify candidates for chemical synthesis and in vitro testing. Our top compound, B5, showed an improved half-maximum inhibitory concentration (IC50 ) value of 0.49 µM for the inhibition of ERCC1-XPF endonuclease activit, and lays the foundation for further testing and optimization. Also, the computational approach reported here can be used to develop DNA repair inhibitors targeting the ERCC1-XPF complex.

Polymeric micellar nanoparticles represent versatile and biocompatible platforms for targeted drug delivery. However, tracking their biodistribution, stability, and clearance profile in vivo is challenging. The goal of this study was to prepare surface-modified micelles with peptide GE11 for targeting the epidermal growth factor receptor (EGFR). In vitro fluorescence studies demonstrated significantly higher internalization of GE11 micelles into EGFR-expressing HCT116 colon cancer cells versus EGFR-negative SW620 cells. Azo coupling chemistry of tyrosine residues in the peptide backbone with aryl diazonium salts was used to label the micelles with radionuclide 64Cu for positron emission tomography (PET) imaging. In vivo analysis of 64Cu-labeled micelles showed prolonged blood circulation and predominant hepatobiliary clearance. The biodistribution profile of EGFR-targeting GE11 micelles was compared with nontargeting HW12 micelles in HCT116 tumor-bearing mice. PET revealed increasing tumor-to-muscle ratios for both micelles over 48 h. Accumulation of GE11-containing micelles in HCT116 tumors was higher compared to HW12-decorated micelles. Our data suggest that the efficacy of image-guided therapies with micellar nanoparticles could be enhanced by active targeting, as demonstrated with cancer biomarker EGFR.

Introduction: Allostatic load (AL) is a composite measure of chronic stress including cardiovascular, immune, and metabolic biomarkers. AL has previously been associated with health disparities in cardiovascular disease, metabolic syndrome, and certain malignancies. However, there are no prior publications to the best of our knowledge evaluating the association of AL and clinical outcomes in patients with advanced prostate cancer (PCa). Methods: We identified 139 subjects with metastatic or biochemically recurrent (BCR) PCa treated at the University of Illinois Hospital and Health Sciences System between January 2015 and May 2022. Subjects were assigned AL scores based on retrospective assessment of 9 biomarkers (systolic and diastolic blood pressure, heart rate, alkaline phosphatase, albumin, creatinine, body mass index, glucose, white blood cell count) collected at the time of diagnosis of advanced disease. Subjects were assigned a total AL score whereby each of the individual 9 biomarkers were given a value of 0 or 1 if threshold value was met. Results: Of the 139 subjects, the median age at PCa diagnosis was 63. The majority were African American (65.4%), 14.4% were Hispanic or Latino, 12.2% were white and non-Hispanic or Latino, and race/ethnicity was other or unknown for 7.9%. A majority (62.6%) had localized or regional nodal disease at diagnosis but later developed metastases or BCR, while 37.4% had de novo metastatic disease. Those with de novo metastatic disease had a higher mean AL score compared to those who had localized or regional nodal disease at diagnosis (2.62 vs. 2.08, p=0.03). Nearly all of the subjects (98.6%) received androgen deprivation therapy (ADT) while 1.4% had surgical castration. Most (66.2%) had local therapies such as surgery or radiation prior to or in addition to ADT. A minority (39.6%) developed castrate-resistant disease while 60.4% did not. For subjects who developed castrate-resistant disease, median time to castrate-resistance was 31 months. Those who developed castrate-resistant disease had a higher mean AL score compared to those who did not (2.58 vs. 2.08, p=0.03). In the study population, 25.9% had a low sum Gleason score (≤7) at diagnosis, 46.0% had a high sum Gleason score (≥8) at diagnosis, and 28.1% did not have a Gleason score available at diagnosis. Subjects with a high sum Gleason score had higher mean AL compared to those with low sum Gleason scores, though this finding did not reach statistical significance (2.47 vs. 1.94, p=0.06). In our study, 32 out of 139 subjects had at least one biomarker missing from their records and therefore not included in the subject’s AL score. The most common biomarkers missing were albumin and alkaline phosphatase. Discussion: In our pilot, single-institution study, higher AL may be associated with more aggressive phenotypes of PCa including de novo metastatic disease, earlier progression to castrate-resistance, and higher Gleason scores. Prospective studies are needed to further validate the role AL plays in PCa aggressiveness. Citation Format: Michael Weinfeld, Ryan Nguyen, Frank Weinberg, Vijayakrishna Gadi, Natalie Reizine. Increased allostatic load is associated with castrate-resistance and de novo metastatic disease in prostate cancer [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr C032.

Inhibition of DNA repair enzymes is an attractive target for increasing the efficacy of DNA damaging chemotherapies. The ERCC1-XPF heterodimer is a key endonuclease in numerous single and double strand break repair processes, and inhibition of the heterodimerization has previously been shown to sensitize cancer cells to DNA damage. In this work, the previously reported ERCC1-XPF inhibitor 4 was used as the starting point for an

New disruptors of the ERCC1-XPF interaction interaction have a synergistic effect with traditional NER inhibitors, in p53 positive cells. Furthermore, the synergy can be resumed in p53 negative cells upon reactivation of the TP53 gene.

the main purpose of this study was to identify new selective antitumor agents.several hydrazonoyl chlorides (HCs) were synthesized and human tumor cell line viability was determined using the MTT assay. Tumor development was assessed using Ehrlich ascites carcinoma (EAC)-bearing mice.our results showed that 2-oxo-N-phenyl-2-(phenylamino)acetohydrazonoyl chloride (compound 4; CPD 4) and 2-oxo-2-(phenylamino)-N-(p-tolyl)acetohydrazonoyl chloride (CPD 5) were the most cytotoxic HCs to human cervical tumor HeLa (IChydrazonoyl chlorides can be considered as hit compounds for the development of new antitumor agents.

Citrus volkameriana Pasq. (Family: Rutacea) is a very common edible and medicinal plant growing in several places in the world including Egypt. We previously studied the toxicity of components of the leaves; however, the peel oil has not been fully analyzed. In the current study, peel oil of C. volkameriana was prepared by hydro-distillation method, and was analyzed for its components using gas chromatography and gas chromatography–mass spectrometry. The recovered oil was formulated as oil in water emulsion using a wet gum technique with gum acacia as an emulsifier. Two compounds were selected from the identified oil components, emulsified using the same technique, and tested for their cytotoxicity along with the emulsified oil on five human tumor cell lines, as well as on one human non-tumorigenic epithelial breast cell line. Our results showed that limonene (68.5%) was found to be the major oil constituent, followed by γ-terpinene (11.3%). Other minor oil components include thymol methyl ether (4%), 4-terpineol (2.9%), cymol (2.4%) and α-pinene (2.1%). The oil showed a very strong cytotoxic effect on the five human tumor cells tested with the highest effect on human hepatoma HepG2 cells (IC50 = 0.038 μL/mL), followed by the effect on human laryngeal carcinoma HEp2 cells (IC50 = 0.045 μL/mL), human breast adenocarcinoma MCF7 cells (IC50 = 0.075 μL/mL), human lung carcinoma A549 cells (IC50 = 0.093 μL/mL), and human cervical cancer Hela cells (IC50 = 0.13 μL/mL). In contrast, the oil showed a lower cytotoxic effect on the non-tumorigenic breast MCF10A cells (IC50 = 0.106 μL/mL). D-limonene possessed similar cytotoxic results as the oil, suggesting a vital role in the cytotoxic effect obtained with the oil. Furthermore, α-pinene showed a strong cytotoxic effect on MCF7 cells (IC50 = 0.072 μL/mL) with a weaker effect on the MCF10A cells (IC50 = 0.185 μL/mL). In conclusion, Citrus volkameriana peel oil and its components have the potential to act as promising cytotoxic agents.

Vertical transmission of Zika virus (ZIKV) leads with high frequency to congenital ZIKV syndrome (CZS), whose worst outcome is microcephaly. However, the mechanisms of congenital ZIKV neurodevelopmental pathologies, including direct cytotoxicity to neural progenitor cells (NPC), placental insufficiency, and immune responses, remain incompletely understood. At the cellular level, microcephaly typically results from death or insufficient proliferation of NPC or cortical neurons. NPCs replicate fast, requiring efficient DNA damage responses to ensure genome stability. Like congenital ZIKV infection, mutations in the polynucleotide 5’-kinase 3’-phosphatase (PNKP) gene, which encodes a critical DNA damage repair enzyme, results in recessive syndromes often characterized by congenital microcephaly with seizures (MCSZ). We thus tested whether there were any links between ZIKV and PNKP.Here we show that two PNKP phosphatase inhibitors or PNKP knockout inhibited ZIKV replication. PNKP relocalized from the nucleus to the cytoplasm in infected cells, co-localizing with the marker of ZIKV replication factories (RF) NS1 and resulting in functional nuclear PNKP depletion. Although infected NPC accumulated DNA damage, they failed to activate the DNA damage checkpoint kinases Chk1 and Chk2. ZIKV also induced activation of cytoplasmic CycA/CDK1 complexes, which trigger unscheduled mitotic entry. Inhibition of CDK1 activity inhibited ZIKV replication and the formation of RF, supporting a role of cytoplasmic CycA/CDK1 in RF morphogenesis. In brief, ZIKV infection induces mitotic catastrophe resulting from unscheduled mitotic entry in the presence of DNA damage. PNKP and CycA/CDK1 are thus host factors participating in ZIKV replication in NPC, and pathogenesis to neural progenitor cells.SignificanceThe 2015-2017 Zika virus (ZIKV) outbreak in Brazil and subsequent international epidemic revealed the strong association between ZIKV infection and congenital malformations, mostly neurodevelopmental defects up to microcephaly. The scale and global expansion of the epidemic, the new ZIKV outbreaks (Kerala state, India, 2021), and the potential burden of future ones pose a serious ongoing risk. However, the cellular and molecular mechanisms resulting in microcephaly remain incompletely understood. Here we show that ZIKV infection of neuronal progenitor cells results in cytoplasmic sequestration of an essential DNA repair protein itself associated with microcephaly, with the consequent accumulation of DNA damage, together with an unscheduled activation of cytoplasmic CDK1/Cyclin A complexes in the presence of DNA damage. These alterations result in mitotic catastrophe of neuronal progenitors, which would lead to a depletion of cortical neurons during development.

Tumour hypoxia negatively impacts therapy outcomes and continues to be a major unsolved clinical problem. Nitroimidazoles are hypoxia selective compounds that become entrapped in hypoxic cells by forming drug-protein adducts. They are widely used as hypoxia diagnostics and have also shown promise as hypoxia-directed therapeutics. However, little is known about the protein targets of nitroimidazoles and the resulting effects of their modification on cancer cells. Here, we report the synthesis and applications of azidoazomycin arabinofuranoside (N

Knockout of Pnkp in adult mice impairs the growth of hair follicle, spermatogonial, and neural progenitor populations., DNA repair proteins are critical to the maintenance of genomic integrity. Specific types of genotoxic factors, including reactive oxygen species generated during normal cellular metabolism or as a result of exposure to exogenous oxidative agents, frequently leads to “ragged” single-strand DNA breaks. The latter exhibits abnormal free DNA ends containing either a 5′-hydroxyl or 3′-phosphate requiring correction by the dual function enzyme, polynucleotide kinase phosphatase (PNKP), before DNA polymerase and ligation reactions can occur to seal the break. Pnkp gene deletion during early murine development leads to lethality; in contrast, the role of PNKP in adult mice is unknown. To investigate the latter, we used an inducible conditional mutagenesis approach to cause global disruption of the Pnkp gene in adult mice. This resulted in a premature aging-like phenotype, characterized by impaired growth of hair follicles, seminiferous tubules, and neural progenitor cell populations. These results point to an important role for PNKP in maintaining the normal growth and survival of these murine progenitor populations.

Introduction: Allostatic load (AL) is a multi-system measure of chronic stress shown to be an emerging framework for understanding disparities in cancer outcomes, but there have been no AL studies in lung cancer. Methods: We conducted a retrospective review of patients diagnosed with stage IV lung adenocarcinoma from 2016 - 2020 at the University of Illinois Hospital and Health System. An AL index included 9 biomarkers (systolic blood pressure, diastolic blood pressure, resting heart rate, BMI, albumin, eGFR, creatinine, glucose, and use of medications for hypertension, diabetes, or hypocholesteremia) with 1 point assigned for each biomarker meeting a pre-determined cutoff. AL was dichotomized between AL-high (5-9) and AL-low (0-4) with median progression-free survival of first-line therapy (mPFS1) and median overall survival (mOS) estimated for both groups with Kaplan-Meier curves. Rates of clinically actionable driver mutations (driver-POS), including EGFR, ALK, ROS1, BRAF V600e, RET, MET, NTRK, and KRAS G12C, were compared for both groups using chi-squared test. Mean AL was compared between those who were driver-POS and those who did not have a clinically actionable driver mutation (driver-NEG) using independent samples t-test. Results: A total of 61 patients were identified with 56% female and 74% former or current tobacco users. The cohort was 49% Black, 21% White, and 13% Hispanic or Latino. Mean AL at diagnosis was 3.3 (+/- 1.4). AL-high patients comprised 20% (12) of the cohort compared with 80% (49) AL-low. Between AL-high and AL-low cohorts, there was no statistically significant difference in mPFS1 (15 vs. 13 months, P = 0.98) and mOS (34 vs. 18 months, P = 0.33). Rates of driver-POS were lower in AL-high compared with AL-low (25% vs 69%, P Conclusions: Patients whose tumors did not have a clinically actionable driver mutation were associated with a higher AL, suggestive of higher chronic stress playing a role in more aggressive tumor biology. No statistically significant survival difference was observed in AL-high versus AL-low populations for mPFS1 and mOS. Larger, prospective trials are planned to correlate AL at diagnosis with clinical and biomarker data. AL, which serves as a measure of physiological dysfunction due to chronic stress associated with social disadvantage, may have implications for tumor biology and clinical outcomes in lung cancer. Citation Format: Ryan H. Nguyen, Michael Weinfeld, Mary Pasquinelli, Frank Weinberg, Natalie Reizine, Lawrence Feldman, Vijayakrishna K. Gadi. Allostatic load, tumor genomics, and outcomes in NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3663.

e14595 Background: Management of cancer-related pain with opioids is hypothesized to decrease efficacy of immune checkpoint inhibitors (ICIs) through immunosuppressive effects of opioids, such as down-regulation of major histocompatibility complex class II. There is limited evidence on how opioids affect outcomes in patients receiving ICIs. Methods: We identified 212 patients at the University of Illinois Hospital and Health Sciences System who received an ICI between January 1, 2015 and July 31, 2021. Overall survival (OS) and progression-free survival (PFS) were compared in patients who were not treated with opioids, patients treated with low-dose opioids (defined as less than 60 morphine milliequivalents per day), and patients treated with high-dose opioids (defined as at least 60 morphine milliequivalents per day). Results: Out of 212 patients who received an ICI, 98 (46.2%) received no opioids, 69 (32.6%) received low-dose opioids, and 45 (21.2%) received high-dose opioids. Among all patients, 105 (49.5%) died during the study duration. The overall median survival time was 23 (95% CI = 16, 38) months for the entire sample. Patients who received opioids at any dose had a median OS of 17 months compared to 37 months in those who received no opioids (HR = 1.53, p = 0.0385). When patients receiving opioids were further divided by dose, survival time was highest in those receiving no opioids, next highest in those receiving low-dose opioids, and lowest in those receiving high-dose opioids (37 months vs 18 months vs 10 months, p = 0.0515). Among all 212 patients, progression of disease occurred in 84 (39.6%) patients. The overall median time-to-progression was 24 months. There was no significant difference in median PFS between those treated with opioids (36 months) versus not (23 months, p = 0.156). Conclusions: We observed an association between opioid therapy, especially at higher doses, and decreased median OS in patients receiving ICIs. On the other hand, there was no statistical association between opioid therapy and median PFS. These data highlight a potential drug interaction in oncology care, and further analysis looking at duration of opioid use and ECOG PS is planned.[Table: see text]

Tumour hypoxia negatively impacts therapy outcomes and continues to be a major unsolved clinical problem. Nitroimidazoles are hypoxia selective compounds that become entrapped in hypoxic cells by forming drug-protein adducts. They are widely used as hypoxia diagnostics and have also shown promise as hypoxia-directed therapeutics. However, little is known about the protein targets of nitroimidazoles and the resulting effects of their modification on cancer cells. Here, we report the synthesis and applications of azidoazomycin arabinofuranoside (N3-AZA), a novel click-chemistry compatible 2-nitroimidazole, designed to facilitate (a) the LC-MS/MS-based proteomic analysis of 2-nitroimidazole targeted proteins in FaDu head and neck cancer cells, and (b) rapid and efficient labelling of hypoxic cells and tissues. Bioinformatic analysis revealed that many of the 62 target proteins we identified participate in key canonical pathways including glycolysis and HIF1A signaling that play critical roles in the cellular response to hypoxia. Critical cellular proteins such as the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and the detoxification enzyme glutathione S-transferase P (GSTP1) appeared as top hits, and N3-AZA adduct formation significantly reduced their enzymatic activities only under hypoxia. Therefore, GAPDH, GSTP1 and other proteins reported here may represent candidate targets to further enhance the potential for nitroimidazole-based cancer therapeutics., Highlights • Azidoazomycin arabinofuranoside (N3-AZA) is a novel hypoxia-targeting compound designed to undergo click chemistry. • We report 62 protein targets of N3-AZA; many of which are critical for cellular response to hypoxia, such as GAPDH and GST. • Binding of N3-AZA reduced GAPDH and GST enzyme activity, indicating that nitroimidazoles can disrupt key cellular pathways. • Fluorescent imaging with N3-AZA click chemistry is highly efficient for mapping cellular and tissue hypoxia. • No relationship was observed between tumour size and hypoxia.

Phosphatase and TENsin homolog deleted on chromosome 10 (PTEN) is a major tumor-suppressor protein that is lost in up to 75% of aggressive colorectal cancers (CRC). The co-depletion of PTEN and a DNA repair protein, polynucleotide kinase 3′-phosphatase (PNKP), has been shown to lead to synthetic lethality in several cancer types including CRC. This finding inspired the development of novel PNKP inhibitors as potential new drugs against PTEN-deficient CRC. Here, we report on the in vitro and in vivo evaluation of a nano-encapsulated potent, but poorly water-soluble lead PNKP inhibitor, A83B4C63, as a new targeted therapeutic for PTEN-deficient CRC. Our data confirmed the binding of A83B4C63, as free or nanoparticle (NP) formulation, to intracellular PNKP using the cellular thermal shift assay (CETSA), in vitro and in vivo. Dose escalating toxicity studies in healthy CD-1 mice, based on measurement of animal weight changes and biochemical blood analysis, revealed the safety of both free and nano-encapsulated A83B4C63, at assessed doses of ≤50 mg/kg. Nano-carriers of A83B4C63 effectively inhibited the growth of HCT116/PTEN−/− xenografts in NIH-III nude mice following intravenous (IV) administration, but not that of wild-type HCT116/PTEN+/+ xenografts. This was in contrast to IV administration of A83B4C63 solubilized with the aid of Cremophor EL: Ethanol (CE), which led to similar tumor growth to that of formulation excipients (NP or CE without drug) or 5% dextrose. This observation was attributed to the higher levels of A83B4C63 delivered to tumor tissue by its NP formulation. Our data provide evidence for the success of NPs of A83B4C63, as novel synthetically lethal nano-therapeutics in the treatment of PTEN-deficient CRC. This research also highlights the potential of successful application of nanomedicine in the drug development process.

The structure-specific ERCC1-XPF endonuclease is essential for repairing bulky DNA lesions and helix distortions induced by UV radiation, which forms cyclobutane pyrimidine dimers (CPDs), or chemicals that crosslink DNA strands such as cyclophosphamide and platinum-based chemotherapeutic agents. Inhibition of the ERCC1-XPF endonuclease activity has been shown to sensitize cancer cells to these chemotherapeutic agents. In this study, we have conducted a structure activity relationship analysis based around the previously identified hit compound, 4-((6-chloro-2-methoxyacridin-9-yl)amino)-2-((4-methylpiperazin1-yl)methyl)phenol (F06), as a reference compound. Three different series of compounds have been rationally designed and successfully synthesized through various modifications on three different sites of F06 based on the corresponding suggestions of the previous pharmacophore model. The in vitro screening results revealed that 2-chloro-9-((3-((4-(2-(dimethylamino)ethyl)piperazin-1-yl)methyl)-4-hydroxyphenyl)amino)acridin-2-ol (B9) has a potent inhibitory effect on the ERCC1-XPF activity (IC50 = 0.49 μM), showing 3-fold improvement in inhibition activity compared to F06. In addition, B9 not only displayed better binding affinity to the ERCC1-XPF complex but also had the capacity to potentiate the cytotoxicity effect of UV radiation and inhibiting the nucleotide excision repair, by the inhibition of removal of CPDs, and cyclophosphamide toxicity to colorectal cancer cells.

The ERCC1-XPF 5'-3' DNA endonuclease complex is involved in the nucleotide excision repair pathway and in the DNA inter-strand crosslink repair pathway, two key mechanisms modulating the activity of chemotherapeutic alkylating agents in cancer cells. Inhibitors of the interaction between ERCC1 and XPF can be used to sensitize cancer cells to such drugs.We tested recently synthesized new generation inhibitors of this interaction and evaluated their capacity to sensitize cancer cells to the genotoxic activity of agents in synergy studies, as well as their capacity to inhibit the protein-protein interaction in cancer cells using proximity ligation assay.Compound B9 showed the best activity being synergistic with cisplatin and mitomycin C in both colon and lung cancer cells. Also, B9 abolished the interaction between ERCC1 and XPF in cancer cells as shown by proximity ligation assay. Results of different compounds correlated with values from our previously obtained in silico predictions.Our results confirm the feasibility of the approach of targeting the protein-protein interaction between ERCC1 and XPF to sensitize cancer cells to alkylating agents, thanks to the improved binding affinity of the newly synthesized compounds.

Polymeric micellar nanoparticles represent versatile and biocompatible platforms for targeted drug delivery. However, tracking their biodistribution, stability, and clearance profile in vivo is challenging. The goal of this study was to prepare surface-modified micelles with peptide GE11 for targeting the epidermal growth factor receptor (EGFR). In vitro fluorescence studies demonstrated significantly higher internalization of GE11 micelles into EGFR-expressing HCT116 colon cancer cells versus EGFR-negative SW620 cells. Azo coupling chemistry of tyrosine residues in the peptide backbone with aryl diazonium salts was used to label the micelles with radionuclide

245 Background: Patients with cancer who have been treated with systemic anticancer therapy are at increased risk of morbidity and mortality from COVID-19 and have been considered a high-priority group for COVID-19 vaccination in the United States. There is limited guidance and data on the appropriate timing of COVID-19 vaccination relative to receipt of systemic anticancer therapy. Methods: We queried the electronic medical record at the University of Illinois Hospital for patients with gastrointestinal, breast, lung, genitourinary, and head and neck tumors who had received intravenous systemic anticancer therapy between January 1, 2021 and May 25, 2021. Baseline variables were obtained as well as details of cancer treatment, vaccination timing relative to cancer treatment, and clinical outcomes. Results: A total of 274 patients received intravenous systemic anticancer therapy during the study period, of which 161 (58.8%) received at least one vaccine dose, and 138 (42.7%) were fully vaccinated. Of the 122 patients who received cancer treatment within 30 days of any vaccine dose, the median age was 64, and 72 (59%) were female gender. Race distribution was 50% Black, 15.6% White, 3.3% Asian; ethnicity was 24.6% Hispanic and 73% not-Hispanic. Treatment regimens consisted of 37.7% chemotherapy, 25.4% immunotherapy, 27.9% combination therapy, and 9.0% targeted therapy. For those who received anticancer therapy within 30 days of a vaccine, median time between any vaccination and treatment was 10 days (range 0-29 days). For those who had at least 60 days of follow-up after first vaccination, all-cause hospitalization rate was 22.4% (23/106). There was no statistical difference in all-cause 60-day hospitalization rate between those who received vaccination within 5 days of anticancer therapy versus those who received it between 6 and 30 days from anticancer therapy (14.3% vs 28.1%, p = 0.1). One patient (0.8%) developed a COVID-19 illness after any vaccine and did not require hospitalization. Conclusions: We observed safe and efficacious COVID-19 vaccination of patients with cancer receiving systemic IV anticancer therapy. COVID-19 infection after vaccination was rare, with no cases requiring hospitalization for COVID-19 illness post-vaccination in this cohort. All-cause hospitalization rates were similar among patients who received a vaccine within or after 5 days of receiving systemic anticancer therapy, suggesting vaccination side effect tolerability. Further quality improvement studies are needed on interventions to increase vaccination rates in this vulnerable population.

Polynucleotide kinase/phosphatase (PNKP) is a DNA strand break repair enzyme that uses separate 5′ kinase and 3′ phosphatase active sites to convert damaged 5′-hydroxyl/3′-phosphate strand termini to ligatable 5′-phosphate/3′-hydroxyl ends. The phosphatase active site has received particular attention as a target for inhibition in cancer therapy development. The phosphatase domain dephosphorylates a range of single and double stranded substrates, however structural studies have shown that the phosphatase catalytic cleft can only bind single stranded substrates. Here we use a catalytically inactive but structurally intact phosphatase mutant to probe interactions between PNKP and a variety of single- and double-stranded DNA substrates using electrophoretic mobility shift assay (EMSA). This work indicates that the phosphatase domain binds 3′-phosphorylated single-stranded DNAs in a manner that is highly dependent on the presence of the 3′-phosphate. Double-stranded substrate binding, in contrast, is not as dependent on the 3′-phosphate. Experiments comparing blunt ended, 3′-overhanging, and frayed ended substrates indicate that the predicted loss of energy due to base pair disruption upon binding of the phosphatase active site is likely balanced by favorable interactions between the liberated complementary strand and PNKP. Comparison of the effects on substrate binding of mutations within the phosphatase active site cleft with mutations in surrounding positively charged surfaces suggests that the surrounding surfaces are important in binding to double-stranded substrates. We further show that while fluorescence polarization methods can detect specific binding of single-stranded DNAs with the phosphatase domain, this method does not detect specific interactions between the PNKP phosphatase and double-stranded substrates.

Granulosa cell tumors of the ovary (GCT) are the predominant type of ovarian sex cord/stromal tumor. Although prognosis is generally favorable, the outcome for advanced and recurrent GCT is poor. A better understanding of the molecular pathogenesis of GCT is critical to developing effective therapeutic strategies. Here we have examined the potential role of the runt-related transcription factor RUNX3. There are only two GCT cell lines available. While RUNX3 is silenced in the GCT cell line KGN cells, it is highly expressed in another GCT cell line, COV434 cells. Re-expression of RUNX3 promotes proliferation, anchorage-independent growth, and motility in KGN cells in vitro and tumor formation in mice in vivo. Furthermore, expression of a dominant negative form of RUNX3 decreases proliferation of COV434 cells. To address a potential mechanism of action, we examined expression of cyclin D2 and the CDK inhibitor p27Kip1, two cell cycle regulators known to be critical determinants of GCT cell proliferation. We found that RUNX3 upregulates the expression of cyclin D2 at the mRNA and protein level, and decreases the level of the p27Kip1 protein, but not p27Kip1 mRNA. In conclusion, we demonstrate that RUNX proteins are expressed in GCT cell lines and human GCT specimens, albeit at variable levels, and RUNX3 may play an oncogenic role in a subset of GCTs.

Large volumes of oil sands process-affected water (OSPW) are produced by the oil sands surface mining industry during alkaline hot-water extraction of bitumen. It is well documented that the acid extractable organics (AEOs) in OSPW, a highly complex mixture of acidic and polar neutral substances, are acutely toxic; but few studies have examined the genotoxicity or mutagenicity of this mixture. In the present study, the in vitro SOS Chromotest and the Ames test (TA98 and TA100 strains) were used to evaluate genotoxicity and mutagenicity for whole OSPW AEOs in the presence and absence of biotransformation by rat S9 liver enzymes. Two subfractions were also examined in the same assays: neutral extractable fraction (F1-NE), and the subsequent acid extractable fraction (F2-AE). In the SOS assay, whole AEO was cytotoxic when concentrated 2× (i.e., twice as concentrated as the environmental sample) and showed increasing genotoxic response above 6×. Co-exposure with S9 had a protective effect on the cell SOS-inducing factor and survival but did not eliminate genotoxicity above 6× concentrations. Most of the cytotoxicity was attributable to F2-AE, but both F1-NE and F2-AE had similar genotoxic dose-responses above 6×. In the Ames test without S9, whole AEO was mutagenic in both strains above 10× concentrations. Co-incubation with S9 had little effect on the TA100 strain but with TA98 resulted in bioactivation at midlevel doses (1.5-6.3×) and protection at higher doses (10-25×). The 2 subfractions were mutagenic in both strains but with different dose-responses. Further research in vivo or in more relevant cells is warranted to investigate the carcinogenic risks of OSPW. Environ Toxicol Chem 2017;36:1397-1404. © 2016 SETAC.

Introduction The redox characteristics of 1,2,4-benzotriazine-1,4-dioxides (BTDOs) make them potential radiosensitizing agents for hypoxic cells in solid human cancers. Tirapazamine (TPZ) is the most clinically tested BTDO radiosensitizer, despite its toxicity at effective doses. To date, no BTDOs have been developed as diagnostic markers of tissue hypoxia. Hypothesis TPZ analogues with appropriate reporting groups can act as potential radiosensitizers and hypoxia selective diagnostics. Experimental and results 3-Chloro-1,2,4-benzotriazine 1-oxide was substituted at the C3 position to afford 3-(2-hydroxyethoxyethyl)-amino-1,2,4-benzotriazine-1-oxide, which was oxidized to 3-(2-hydroxyethoxyethyl)-amino-1,2,4-benzotriazine-1,4-dioxide (HO-EOE-TPZ) or converted to 3-(2-tosyloxyethoxyethyl)-amino-1,2,4-benzotriazine-1,4-dioxide (Tos-EOE-TPZ). Tos-EOE-TPZ was intended for use as a synthon for preparing 3-(2-azidoethoxyethyl)-amino-1,2,4-benzotriazine-1,4-dioxide (N3-EOE-TPZ) and 3-(2-iodoethoxyethyl)-amino-1,2,4-benzotriazine-1,4-dioxide (I-EOE-TPZ). The logP values (−0.69 to 0.61) for these molecules bracketed that of TPZ (−0.34). Cell line dependent cytotoxicities (IC50) in air were in the 10–100 μM range, with Hypoxia Cytotoxicity Ratios (HCR; IC50-air/IC50-hypoxia) of 5–10. LUMO calculations indicated that these molecules are in the optimal redox range for radiosensitization, offering cell-line-specific Relative Radiosensitization Ratios (RRSR; SER/OER) of 0.58–0.88, compared to TPZ (0.67–0.76). Conclusion The LUMO, IC50, HCR and RRSR values of 3-(2-substituted ethoxyethyl)-amino-1,2,4-benzotriazine-1,4-dioxides are similar to the corresponding values for TPZ, supporting the conclusion that these TPZ analogues are potentially useful as hypoxia-activated radiosensitizers. Further studies into their biodistributions in animal models are being pursued to determine the in vivo potential in hypoxia management.

Polynucleotide kinase/phosphatase (PNKP) and X-ray repair cross-complementing 1 (XRCC1) are key proteins in the single-strand DNA break repair pathway. Phosphorylated XRCC1 stimulates PNKP by binding to its forkhead-associated (FHA) domain, whereas nonphosphorylated XRCC1 stimulates PNKP by interacting with the PNKP catalytic domain. Here, we have further studied the interactions between these two proteins, including two variants of XRCC1 (R194W and R280H) arising from single-nucleotide polymorphisms (SNPs) that have been associated with elevated cancer risk in some reports. We observed that interaction of the PNKP FHA domain with phosphorylated XRCC1 extends beyond the immediate, well-characterized phosphorylated region of XRCC1 (residues 515-526). We also found that an XRCC1 fragment, comprising residues 166-436, binds tightly to PNKP and DNA and efficiently activates PNKP's kinase activity. However, interaction of either of the SNP-derived variants of this fragment with PNKP was considerably weaker, and their stimulation of PNKP was severely reduced, although they still could bind DNA effectively. Laser microirradiation revealed reduced recruitment of PNKP to damaged DNA in cells expressing either XRCC1 variant compared with PNKP recruitment in cells expressing WT XRCC1 even though WT and variant XRCC1s were equally efficient at localizing to the damaged DNA. These findings suggest that the elevated risk of cancer associated with these XRCC1 SNPs reported in some studies may be due in part to the reduced ability of these XRCC1 variants to recruit PNKP to damaged DNA.