Potential inhibitors of VEGFR1, VEGFR2, and VEGFR3 developed through Deep Learning for the treatment of Cervical Cancer.

Cervical cancer stands as a prevalent gynaecologic malignancy affecting women globally, often linked to persistent human papillomavirus infection. Biomarkers associated with cervical cancer, including VEGF-A, VEGF-B, VEGF-C, VEGF-D, and VEGF-E, show upregulation and are linked to angiogenesis and lymphangiogenesis. This research aims to employ in-silico methods to target tyrosine kinase receptor proteins-VEGFR-1, VEGFR-2, and VEGFR-3, and identify novel inhibitors for Vascular Endothelial Growth Factors receptors (VEGFRs). A comprehensive literary study was conducted which identified 26 established inhibitors for VEGFR-1, VEGFR-2, and VEGFR-3 receptor proteins. Compounds with high-affinity scores, including PubChem ID-25102847, 369976, and 208908 were chosen from pre-existing compounds for creating Deep Learning-based models. RD-Kit, a Deep learning algorithm, was used to generate 43 million compounds for VEGFR-1, VEGFR-2, and VEGFR-3 targets. Molecular docking studies were conducted on the top 10 molecules for each target to validate the receptor-ligand binding affinity. The results of Molecular Docking indicated that PubChem IDs-71465,645 and 11152946 exhibited strong affinity, designating them as the most efficient molecules. To further investigate their potential, a Molecular Dynamics Simulation was performed to assess conformational stability, and a pharmacophore analysis was also conducted for indoctrinating interactions.

Distribution, toxicity load and risk assessment of heavy metals in the groundwater of Dhemaji, Assam, India.

Metal contamination in drinking water has drawn attention since it gravely jeopardizes human health. This study was conducted in pre- and post-monsoon season in 2021 at Dhemaji, Assam, India. It characterized metal pollutants in groundwater, their distribution, possible sources, and evaluated the potential toxicity and associated health risk assessment. The seasonal mean concentration of Fe in both seasons is observed highest followed by Mn, Zn, Cu, As, and Ni. Furthermore, the metal concentrations during pre-monsoon are comparatively higher. The geogenic processes and agricultural practices are the major sources of groundwater metal contamination as evident from the statistical analysis. The different pollution indices viz. Heavy-metal Pollution Index (HPI), Heavy-metal Evaluation Index (HEI) and Degree of Contamination (Cd) suggested that groundwater is not suitable for drinking uses. The Heavy Metal Toxicity Load (HMTL) suggesting As, Co, Mn and Hg should be removed from the groundwater to ensure safety. Water pollution indices (WPI) suggest that Fe, Mn, As and Ni are the main pollution-causing metals in the study area which may be restored under the BIS and WHO limit by diluting the water. The human health risk has been calculated by carcinogenic and non-carcinogenic risk assessment. The non-carcinogenic risk for adults and children is within the threshold limit. The carcinogenic risk shows that continuous exposure of As and Ni may give rise to cancer among adults and children in the region. Therefore, comprehensive groundwater quality monitoring with well-planned treatment should be needed to provide safe and clean drinking water in the studied area.

Unveiling the ESR1 Conformational Stability and Screening Potent Inhibitors for Breast Cancer Treatment

BACKGROUND: The current study recognizes the significance of estrogen receptor alpha (ERα) as a member of the nuclear receptor protein family, which holds a central role in the pathophysiology of breast cancer. ERα serves as a valuable prognostic marker, with its established relevance in predicting disease outcomes and treatment responses. METHOD: In this study, computational methods are utilized to search for suitable drug-like compounds that demonstrate analogous ligand binding kinetics to ERα. RESULTS: Docking-based simulation screened out the top 5 compounds - ZINC13377936, NCI35753, ZINC35465238, ZINC14726791, and NCI663569 against the targeted protein. Further, their dynamics studies reveal that the compounds ZINC13377936 and NCI35753 exhibit the highest binding stability and affinity. CONCLUSION: Anticipating the competitive inhibition of ERα protein expression in breast cancer, we envision that both ZINC13377936 and NCI35753 compounds hold substantial promise as potential therapeutic agents. These candidates warrant thorough consideration for rigorous In vitro and In vivo evaluations within the context of clinical trials. The findings from this current investigation carry significant implications for the advancement of future diagnostic and therapeutic approaches for breast cancer.

Assessment of textile industry effluent (untreated and microbially treated) induced genotoxic, haematological, biochemical, histopathological and ultrastructural alterations in fresh water fish Channa punctata.

The unregulated expulsion of untreated textile water into water bodies is a major hazard to aquatic ecosystems. The present investigation was contrived to estimate the impact of textile dye bath effluent (untreated and microbially treated) on fish Channa punctata. Untreated effluent-exposed fish showed extremely altered behaviour (air gulping, erratic and speedy movements, increased opercular activity) and morphology (deposition of dyes on skin and scales, high pigmentation, mucus exudation). Significantly increased micronuclei (1.61-, 1.28-, 1.38-fold) and aberrant cell frequency (1.37-, 1.45-, 1.28-fold) was observed in untreated group as compared to treated group after 15, 30, and 45 days of exposure. Tail length, % tail intensity, tail moment and olive tail moment were also enhanced in all the exposed tissues. However, maximum damage was noticed in gill tissues showing 1.19-, 1.37-, 1.34- and 1.50-fold increased TL, %TI, TM and OTM in untreated group as compared to treated group after 45 days of exposure. On comparing untreated and treated groups, increased blood parameters and significantly reduced white blood cell count (WBC) were noticed in treated group. Significantly enhanced alterations in biochemical parameters were also analysed in untreated group. Reduced alterations in enzymological levels of fishes exposed to treated effluent indicate lesser toxic nature of the degraded metabolites of dye. Histological analysis in fishes exposed to untreated effluent showed several deformities in liver (necrosis, congestion, fusion of cells and melanomacrophage infiltration) and gill tissues (necrosis, bending of lamellae and severe aneurysm). Scanning electron microscopy (SEM) analysis further reaffirmed the pathologies observed in histological analysis. Fewer structural alterations were noticed in treated effluent fishes. The results concluded that untreated effluent inflicted toxicity potential on morphology as well as physiological defects in fish, and the severity increased with increasing duration of exposure, whereas reduction in toxicity in microbially treated groups can be analysed for aquacultural purposes owing to their lesser toxic nature.

Obesity impairs cardiolipin-dependent mitophagy and therapeutic intercellular mitochondrial transfer ability of mesenchymal stem cells.

Mesenchymal stem cell (MSC) transplantation alleviates metabolic defects in diseased recipient cells by intercellular mitochondrial transport (IMT). However, the effect of host metabolic conditions on IMT and thereby on the therapeutic efficacy of MSCs has largely remained unexplored. Here we found impaired mitophagy, and reduced IMT in MSCs derived from high-fat diet (HFD)-induced obese mouse (MSC-Ob). MSC-Ob failed to sequester their damaged mitochondria into LC3-dependent autophagosomes due to decrease in mitochondrial cardiolipin content, which we propose as a putative mitophagy receptor for LC3 in MSCs. Functionally, MSC-Ob exhibited diminished potential to rescue mitochondrial dysfunction and cell death in stress-induced airway epithelial cells. Pharmacological modulation of MSCs enhanced cardiolipin-dependent mitophagy and restored their IMT ability to airway epithelial cells. Therapeutically, these modulated MSCs attenuated features of allergic airway inflammation (AAI) in two independent mouse models by restoring healthy IMT. However, unmodulated MSC-Ob failed to do so. Notably, in human (h)MSCs, induced metabolic stress associated impaired cardiolipin-dependent mitophagy was restored upon pharmacological modulation. In summary, we have provided the first comprehensive molecular understanding of impaired mitophagy in obese-derived MSCs and highlight the importance of pharmacological modulation of these cells for therapeutic intervention. A MSCs obtained from (HFD)-induced obese mice (MSC-Ob) show underlying mitochondrial dysfunction with a concomitant decrease in cardiolipin content. These changes prevent LC3-cardiolipin interaction, thereby reducing dysfunctional mitochondria sequestration into LC3-autophagosomes and thus impaired mitophagy. The impaired mitophagy is associated with reduced intercellular mitochondrial transport (IMT) via tunneling nanotubes (TNTs) between MSC-Ob and epithelial cells in co-culture or in vivo. B Pyrroloquinoline quinone (PQQ) modulation in MSC-Ob restores mitochondrial health, cardiolipin content, and thereby sequestration of depolarized mitochondria into the autophagosomes to alleviate impaired mitophagy. Concomitantly, MSC-Ob shows restoration of mitochondrial health upon PQQ treatment (MSC-ObPQQ). During co-culture with epithelial cells or transplantation in vivo into the mice lungs, MSC-ObPQQ restores IMT and prevents epithelial cell death. C Upon transplantation in two independent allergic airway inflammatory mouse models, MSC-Ob failed to rescue the airway inflammation, hyperactivity, metabolic changes in epithelial cells. D PQQ modulated MSCs restored these metabolic defects and restored lung physiology and airway remodeling parameters.

Characterization of Polycyclic Aromatic Hydrocarbons (PAHs) associated with fine aerosols in ambient atmosphere of high-altitude urban environment in Sikkim Himalaya.

Polycyclic Aromatic Hydrocarbons (PAHs) compounds are ubiquitous in ambient air due to their persistence, carcinogenicity, and mutagenicity. Gangtok being one of the cleanest cities in India located in Eastern Himalayan region, witnesses high developmental activities with enhanced urbanization affecting the ambient air quality. The present study aims to measure PM2.5 and PAHs in the ambient atmosphere of the Sikkim Himalaya to understand the influence of natural and anthropogenic activities on aerosol loading and their chemical characteristics. The PM2.5 samples were collected and analysed for the duration from Jan 2020 to Feb 2021.The seasonal mean concentrations of PM2.5 and PAHs were observed to be high during autumn and low during summer season. Overall, the annual mean concentration of PM2.5 was found higher than the prescribed limit of World Health Organization and National Ambient Air Quality Standards. The concentration of the 16 individual PAHs were found to be highest during autumn season (55.26 ± 37.15 ng/m3). Among the different PAHs, the annual mean concentration of fluorene (3.29 ± 4.07 ng/m3) and naphthalene (1.15 ± 3.76 ng/m3) were found to be the highest and lowest, respectively. The Molecular Diagnostic Ratio (MDR) test reveals higher contribution from heavy traffic activities throughout the winter and autumn seasons. The other possible sources identified over the region are fossil fuel combustion, and biomass burning. The multivariate statistical analysis (Multifactor Principal Component Analysis) also indicates a strong association between PM2.5 /PAHs and meteorological variables across the region in different seasons. The precipitation and wind pattern during the study period suggests that major contribution of the PM2.5 and PAHs were from local sources, with minimal contribution from long-range transport. The findings are important for comprehending the trends of PAH accumulation over a high-altitude urban area, and for developing sustainable air quality control methods in the Himalayan region.

Oxygen- and Sulphur-Containing Heterocyclic Compounds as Potential Anticancer Agents.

Oxygen- and sulphur-based heterocycles form the core structure of many biologically active molecules as well as U.S. FDA-approved drugs. Moreover, they possess broad range of biological activities, viz. anticancer, antiinflammatory, antioxidant, antitumour, antibacterial, antiviral, antidiabetic, anticonvulsant, anti-tubercular, analgesic, anti-leishmanial, antimalarial, antifungal, and anti-histaminic, Hence, O- and S-based heterocycles are gaining more attention in recent years on the road to the discovery of innovative anticancer drugs after the extensive investigation of nitrogen-based heterocycles as anticancer agents. Several attempts have been made to synthesize fused oxygen- and sulphur-based heterocyclic derivatives as joining one heterocyclic moiety with another may lead to improvement in the biological profile of a molecule. Humans have been cursed with cancer since long time. Despite the development of several heterocyclic anticancer medications such as 5-fluorouracil, doxorubicin, methotrexate, and daunorubicin, cure of cancer is difficult. Hence, researchers are trying to synthesize new fused/spiro heterocyclic molecules to discover novel anticancer drugs which may show promising anticancer effects with fewer side effects. Furthermore, fused heterocycles behave as DNA intercalating agents which have the ability to interact with DNA, leading to cell death thereby exerting anticancer effect. This review article highlights the synthesis and anticancer potentiality of oxygen- and sulphur-containing heterocyclic compounds covering the period from 2011 to 2021.

A Multi-target Drug Designing for BTK, MMP9, Proteasome and TAK1 for the Clinical Treatment of Mantle Cell Lymphoma.

BACKGROUND: Mantle cell lymphoma (MCL) is a type of non-Hodgkin lymphoma characterized by the mutation and overexpression of the cyclin D1 protein by the reciprocal chromosomal translocation t(11;14)(q13:q32). AIM: The present study aims to identify potential inhibition of MMP9, Proteasome, BTK, and TAK1 and determine the most suitable and effective protein target for the MCL. METHODOLOGY: Nine known inhibitors for MMP9, 24 for proteasome, 15 for BTK and 14 for TAK1 were screened. SB-3CT (PubChem ID: 9883002), oprozomib (PubChem ID: 25067547), zanubrutinib (PubChem ID: 135565884) and TAK1 inhibitor (PubChem ID: 66760355) were recognized as drugs with high binding capacity with their respective protein receptors. 41, 72, 102 and 3 virtual screened compounds were obtained after the similarity search with compound (PubChem ID:102173753), PubChem compound SCHEMBL15569297 (PubChem ID:72374403), PubChem compound SCHEMBL17075298 (PubChem ID:136970120) and compound CID: 71814473 with best virtual screened compounds. RESULT: MMP9 inhibitors show commendable affinity and good interaction profile of compound holding PubChem ID:102173753 over the most effective established inhibitor SB-3CT. The pharmacophore study of the best virtual screened compound reveals its high efficacy based on various interactions. The virtual screened compound's better affinity with the target MMP9 protein was deduced using toxicity and integration profile studies. CONCLUSION: Based on the ADMET profile, the compound (PubChem ID: 102173753) could be a potent drug for MCL treatment. Similar to the established SB-3CT, the compound was non-toxic with LD50 values for both the compounds lying in the same range.

Design of PD-L1 inhibitors for lung cancer.

The progression of lung cancer is associated with inactivation of programmed cell death protein 1, abbreviated as PD- 1 which regulates the suppression of the body's immune system by suppressing T- cell inflammatory activity and is responsible for preventing cancer cell growth. It is of interest to identify inhibitors for PD-L1 dimeric structure through molecular docking and virtual screening. The virtual screened compound XGIQBUNWFCCMAS-UHFFFAOYSA-N (PubChem CID: 127263272) displays a high affinity with the target protein. ADMET analysis and cytotoxicity studies further add weight to this compound as a potential inhibitor of PD-L1. The established compound BMS-202 still shows the high re-rank score, but the virtual screened drug possesses a better ADMET profile with a higher intestinal absorption value and lower toxicity.

Structure-Based Virtual Screening for the Identification of High Affinity Compounds as Potent VEGFR2 Inhibitors for the Treatment of Renal Cell Carcinoma.

INTRODUCTION: Renal Cell Carcinoma is a common type of renal cancer-causing deaths worldwide which is characterized by sustained angiogenesis. VEGF and its receptors play a major role in physiologic and pathologic angiogenesis, which is marked in tumour progression and metastasis development. Induction of VEGF genes occur due to hypoxic condition induced by tumour growth after a critical size in cancerous cell. Signal transduction networks originated by VEGFA/VEGFR2, (a notable ligand-receptor complex in the VEGF system) leads to major angiogenesis events ranging from endothelial cell proliferation, to new vessel formation, Furthermore, differential expression of VEGF-VEGFR mRNA also found in different types of RCC. AIM: The aim of present study is to inhibit the VEGFR2 protein by the action of certain inhibitors and then to search an efficient inhibitor. MATERIALS AND METHODS: A total of 23 potential inhibitors were searched and used to target the protein using the concept of molecular docking. Among 23 inhibitors, CHEMBL346631 shows best affinity with the target protein and was used for high throughput virtual screening to find similar compounds. The compound obtained from virtual screeningSCHEMBL469307, shows much more better affinity with VEGFR2 than CHEMBL346631. CONCLUSION: Relative study for both the compounds showed a minor difference in relevant properties. The compound SCHEMBL469307 have a high potential to inhibit the VGFR2 protein and can be backed for future studies in Renal Cell Carcinoma.

Molecular Imaging of Mesothelin-Expressing Ovarian Cancer with a Human and Mouse Cross-Reactive Nanobody.

Mesothelin is an epithelial marker highly expressed at the cell surface of cancer cells from diverse origins, including ovarian and pancreatic adenocarcinomas and mesotheliomas. Previously, we identified and characterized an antimesothelin nanobody (NbG3a) for in vitro diagnostic applications. The main goal of this research was to establish the potential of NbG3a as a molecular imaging agent. Site-specific biotinylated NbG3a (bNbG3a) was bound to streptavidin-conjugated reagents for in vitro and in vivo assays. Initially, we performed microscale thermophoresis to determine the binding affinity between bNbG3a and human ( Kd = 46 ± 8 nM) or mouse ( Kd = 4.8 ± 0.4 nM) mesothelin protein. The human and mouse cross-reactivity was confirmed by in vivo optical imaging using bNbG3a bound to fluorescent streptavidin. We also localized the binding site of nNbG3a on human mesothelin using overlapping peptide scan. NbG3a recognized an epitope within residues 21-65 of the mature membrane bound form of human mesothelin, which is part of the N-terminal region of mesothelin that is important for interactions between mesothelin on peritoneal cells and CA125 on tumor cells. Next, the bNbG3a in vivo half-life after intravenous injection in healthy mice was estimated by ELISA assay to be 5.3 ± 1.3 min. In tumor-bearing animals, fluorescent bNbG3a accumulated in a subcutaneous ovarian xenograft (A1847) and in two syngeneic, orthotopic ovarian tumors (intraovary and intraperitoneal ID8) within an hour of intravenous injection that peaked by 4 h and persisted up to 48 h. MRI analysis of bNbG3a-targeted streptavidin-labeled iron oxides showed that the MRI signal intensity decreased 1 h after injection for a subcutaneous xenograft model of ovarian cancer for bNbG3a-labeled iron oxides compared to unlabeled iron oxides. The signal intensity differences continued up to the final time point at 24 h post injection. Finally, in vivo immunofluorescence 24 or 48 h after bNbG3a intravenous injection showed bNbG3a diffuse distribution of both xenograft and syngeneic ovarian tumors, with local areas of high concentration throughout A1847 human tumor. The data support the use of NbG3a for continued preclinical development and translation to human applications for cancers that overexpress mesothelin.

Radiosensitization by PARP Inhibition in DNA Repair Proficient and Deficient Tumor Cells: Proliferative Recovery in Senescent Cells.

Radiotherapy continues to be a primary modality in the treatment of cancer. In addition to promoting apoptosis, radiation-induced DNA damage can promote autophagy and senescence, both of which can theoretically function to prolong tumor survival. In this work, we tested the hypothesis that autophagy and/or senescence could be permissive for DNA repair, thereby facilitating tumor cell recovery from radiation-induced growth arrest and/or cell death. In addition, studies were designed to elucidate the involvement of autophagy and senescence in radiosensitization by PARP inhibitors and the re-emergence of a proliferating tumor cell population. In the context of this work, the relationship between radiation-induced autophagy and senescence was also determined. Studies were performed using DNA repair-proficient HCT116 colon carcinoma cells and a repair-deficient ligase IV(-/-) isogenic cell line. Exposure to radiation promoted a parallel induction of autophagy and senescence that was strongly correlated with the extent of persistent H2AX phosphorylation in both cell lines, however, inhibition of autophagy failed to suppress senescence, indicating that the two responses were dissociable. Exposure to radiation resulted in a transient arrest in the HCT116 cells while arrest was prolonged in the ligase IV(-/-) cells, however, both cell lines ultimately recovered proliferative function, which may reflect maintenance of DNA repair capacity. The PARP inhibitors, olaparib and niraparib, increased the extent of persistent DNA damage induced by radiation exposure as well as the extent of both autophagy and senescence. Neither cell line underwent significant apoptosis by radiation exposure alone or in the presence of the PARP inhibitors. Inhibition of autophagy failed to attenuate radiosensitization, indicating that autophagy was not involved in the action of the PARP inhibitors. As with radiation alone, despite sensitization by PARP inhibition, proliferative recovery was evident within a period of 10-20 days. While inhibition of DNA repair via PARP inhibition may initially sensitize tumor cells to radiation via the promotion of senescence, this strategy does not appear to interfere with proliferative recovery, which could ultimately contribute to disease recurrence.

Role of Interleukin-1 in Radiation-Induced Cardiomyopathy.

Thoracic X-ray therapy (XRT), used in cancer treatment, is associated with increased risk of heart failure. XRT-mediated injury to the heart induces an inflammatory response leading to cardiomyopathy. The aim of this study was to determine the role of interleukin (IL)-1 in response to XRT injury to the heart and on the cardiomyopathy development in the mouse. Female mice with genetic deletion of the IL-1 receptor type I (IL-1R1 knockout mice [IL-1R1 KO]) and treatment with recombinant human IL-1 receptor antagonist anakinra, 10 mg/kg twice daily for 7 d, were used as independent approaches to determine the role of IL-1. Wild-type (wt) or IL-1R1 KO mice were treated with a single session of XRT (20 or 14 gray [Gy]). Echocardiography (before and after isoproterenol challenge) and left ventricular (LV) catheterization were performed to evaluate changes in LV dimensions and function. Masson's trichrome was used to assess myocardial fibrosis and pericardial thickening. After 20 Gy, the contractile reserve was impaired in wt mice at d 3, and the LV ejection fraction (EF) was reduced after 4 months when compared with sham-XRT. IL-1R1 KO mice had preserved contractile reserve at 3 d and 4 months and LVEF at 4 months after XRT. Anakinra treatment for 1 d before and 7 d after XRT prevented the impairment in contractile reserve. A significant increase in LV end-diastolic pressure, associated with increased myocardial interstitial fibrosis and pericardial thickening, was observed in wt mice, as well as in IL-1R1 KO-or anakinra-treated mice. In conclusion, induction of IL-1 by XRT mediates the development of some, such as the contractile impairment, but not all aspects of the XRT-induced cardiomyopathy, such as myocardial fibrosis or pericardial thickening.

Yet another function of p53--the switch that determines whether radiation-induced autophagy will be cytoprotective or nonprotective: implications for autophagy inhibition as a therapeutic strategy.

The influence of autophagy inhibition on radiation sensitivity was studied in human breast, head and neck, and non-small cell lung cancer cell lines, in cell lines that were either wild type or mutant/null in p53, and in cells where p53 was inducible or silenced. Whereas ionizing radiation promoted autophagy in all tumor cell lines studied, pharmacological inhibition of autophagy and/or genetic silencing of autophagy genes failed to influence sensitivity to radiation in p53 mutant Hs578t breast tumor cells, HN6 head and neck tumor cells, and H358 non-small cell lung cancer cells. The requirement for functional p53 in the promotion of cytoprotective autophagy by radiation was confirmed by the observation that radiation-induced autophagy was nonprotective in p53 null H1299 cells but was converted to the cytoprotective form with induction of p53. Conversely, whereas p53 wild-type HN30 head and neck cancer cells did show sensitization to radiation upon autophagy inhibition, HN30 cells in which p53 was knocked down using small hairpin RNA failed to be sensitized by pharmacological autophagy inhibition. Taken together, these findings indicate that radiation-induced autophagy can be either cytoprotective or nonprotective, a functional difference related to the presence or absence of function p53. Alternatively, these findings could be interpreted to suggest that whereas radiation can induce autophagy independent of p53 status, inhibition of autophagy promotes enhanced radiation sensitivity through a mechanism that requires functional p53. These observations are likely to have direct implications with respect to clinical efforts to modulate the response of malignancies to radiation through autophagy inhibition.

Cytotoxic autophagy in cancer therapy.

Autophagy is a process of cellular self-digestion, whereby the cell degrades subcellular materials in order to generate energy and metabolic precursors in order to prolong survival, classically under conditions of nutrient deprivation. Autophagy can also involve the degradation of damaged or aged organelles, and misfolded or damaged proteins to eliminate these components that might otherwise be deleterious to cellular survival. Consequently, autophagy has generally been considered a prosurvival response. Many, if not most chemotherapeutic drugs and radiation also promote autophagy, which is generally considered a cytoprotective response, in that its inhibition frequently promotes apoptotic cells death. Furthermore, it has been shown that conventional chemotherapeutic drugs and radiation alone rarely induce a form of autophagy that leads to cell death. However, there are multiple examples in the literature where newer chemotherapeutic agents, drug combinations or drugs in combination with radiation promote autophagic cell death. This review will describe autophagic cell death induced in breast tumor cells, lung cancer cells as well as glioblastoma, demonstrating that it cannot be concluded that stress induced autophagy is, of necessity, cytoprotective in function.

Autophagy and radiosensitization in cancer.

Autophagy is a natural self-degradative process by which cells eliminate misfolded proteins and damaged organelles. Autophagy has been shown to have multiple functions in tumor cells that may be dependent on the tumor type and the treatment conditions. Autophagy can have a cytoprotective role and be thought of as a survival mechanism or be cytotoxic in nature and mediate cell death. Radiation, one of the primary treatments for many different types of cancer, almost uniformly promotes autophagy in tumor cells. While autophagy produced in response to radiation is often considered to be cytoprotective, radiation-induced autophagy has also been shown to mediate susceptibility to radiation. This review addresses the complexity of autophagy in response to radiation treatment in three different cancer models, specifically lung cancer, breast cancer and glioblastoma. A deeper understanding of the different roles played by autophagy in response to radiation should facilitate the development of approaches for enhancing the therapeutic utility of radiation by providing strategies for combination treatment with unique radiosensitizers as well as preventing the initiation of strategies which are likely to attenuate the effectiveness of radiation therapy.

A novel cytostatic form of autophagy in sensitization of non-small cell lung cancer cells to radiation by vitamin D and the vitamin D analog, EB 1089.

The standard of care for unresectable lung cancer is chemoradiation. However, therapeutic options are limited and patients are rarely cured. We have previously shown that vitamin D and vitamin D analogs such as EB 1089 can enhance the response to radiation in breast cancer through the promotion of a cytotoxic form of autophagy. In A549 and H460 non-small cell lung cancer (NSCLC) cells, 1,25-D3 (the hormonally active form of vitamin D) and EB 1089 prolonged the growth arrest induced by radiation alone and suppressed proliferative recovery, which translated to a significant reduction in clonogenic survival. In H838 or H358 NSCLC cells, which lack VDR/vitamin D receptor or functional TP53, respectively, 1,25-D3 failed to modify the extent of radiation-induced growth arrest or suppress proliferative recovery post-irradiation. Sensitization to radiation in H1299 NSCLC cells was evident only when TP53 was induced in otherwise tp53-null H1299 NSCLC cells. Sensitization was not associated with increased DNA damage, decreased DNA repair or an increase in apoptosis, necrosis, or senescence. Instead sensitization appeared to be a consequence of the conversion of the cytoprotective autophagy induced by radiation alone to a novel cytostatic form of autophagy by the combination of 1,25-D3 or EB 1089 with radiation. While both pharmacological and genetic suppression of autophagy or inhibition of AMPK phosphorylation sensitized the NSCLC cells to radiation alone, inhibition of the cytostatic autophagy induced by the combination treatment reversed sensitization. Evidence for selectivity was provided by lack of radiosensitization in normal human bronchial cells and cardiomyocytes. Taken together, these studies have identified a unique cytostatic function of autophagy that appears to be mediated by VDR, TP53, and possibly AMPK in the promotion of an enhanced response to radiation by 1,25-D3 and EB 1089 in NSCLC.

Poly (ethylene glycol)-armed hyperbranched polyoxetanes for anticancer drug delivery.

A facile method for synthesis of polyethylene glycol (PEG)-armed hyperbranched polyoxetanes is presented as well as characterization and use in drug delivery. A series of hyperbranched polyoxetanes with multiple PEG arms were synthesized via a one-pot cationic ring-opening polymerization of 3-ethyl-3-hydroxymethyloxetane (EHMO) and its PEGylated derivative (EPMO), in which the feed mass ratio of EHMO to EPMO was 98:2, 96:4, 74:26, or 17:83. Characterization methods included NMR, DLS, FT-IR, DSC, and SEM. Toxicity of the synthesized polymers to human dermal fibroblasts was evaluated using the MTT assay. Formulation into particles was carried out to encapsulate the anticancer drug camptothecin using the single oil-in-water (o/w) solvent evaporation method. The resulting drug encapsulated particles were evaluated for antitumor activity using HN12 cells.

The autophagy-senescence connection in chemotherapy: must tumor cells (self) eat before they sleep?

Exposure of MCF-7 breast tumor cells or HCT-116 colon carcinoma cells to clinically relevant concentrations of doxorubicin (Adriamycin; Farmitalia Research Laboratories, Milan, Italy) or camptothecin results in both autophagy and senescence. To determine whether autophagy is required for chemotherapy-induced senescence, reactive oxygen generation induced by Adriamycin was suppressed by N-acetyl cysteine and glutathione, and the induction of ataxia telangiectasia mutated, p53, and p21 was modulated pharmacologically and/or genetically. In all cases, autophagy and senescence were collaterally suppressed. The close association between autophagy and senescence indicated by these experiments reflects their collateral regulation via common signaling pathways. The potential relationship between autophagy and senescence was further examined through pharmacologic inhibition of autophagy with chloroquine and 3-methyl-adenine and genetic ablation of the autophagy-related genes ATG5 and ATG7. However, inhibition of autophagy by pharmacological and genetic approaches could not entirely abrogate the senescence response, which was only reduced and/or delayed. Taken together, our findings suggest that autophagy and senescence tend to occur in parallel, and furthermore that autophagy accelerates the development of the senescent phenotype. However, these responses are not inexorably linked or interdependent, as senescence can occur when autophagy is abrogated.