scholarly journals Targeting Hypoxia: Hypoxia-Activated Prodrugs in Cancer Therapy

2021 ◽  
Vol 11 ◽  
Author(s):  
Yue Li ◽  
Long Zhao ◽  
Xiao-Feng Li

Hypoxia is an important characteristic of most solid malignancies, and is closely related to tumor prognosis and therapeutic resistance. Hypoxia is one of the most important factors associated with resistance to conventional radiotherapy and chemotherapy. Therapies targeting tumor hypoxia have attracted considerable attention. Hypoxia-activated prodrugs (HAPs) are bioreductive drugs that are selectively activated under hypoxic conditions and that can accurately target the hypoxic regions of solid tumors. Both single-agent and combined use with other drugs have shown promising antitumor effects. In this review, we discuss the mechanism of action and the current preclinical and clinical progress of several of the most widely used HAPs, summarize their existing problems and shortcomings, and discuss future research prospects.

Author(s):  
Rashmi Kumari ◽  
Vasumathy R ◽  
Dhanya Sunil ◽  
Raghumani Singh Ningthoujam ◽  
Badri Narain Pandey ◽  
...  

AbstractThe bioreductive enzymes typically upregulated in hypoxic tumor cells can be targeted for developing diagnostic and drug delivery applications. In this study, a new fluorescent probe 4−(6−nitro−1,3−dioxo−1H−benzo[de]isoquinolin−2(3H)−yl)benzaldehyde (NIB) based on a nitronaphthalimide skeleton that could respond to nitroreductase (NTR) overexpressed in hypoxic tumors is designed and its application in imaging tumor hypoxia is demonstrated. The docking studies revealed favourable interactions of NIB with the binding pocket of NTR-Escherichia coli. NIB, which is synthesized through a simple and single step imidation of 4−nitro−1,8−naphthalic anhydride displayed excellent reducible capacity under hypoxic conditions as evidenced from cyclic voltammetry investigations. The fluorescence measurements confirmed the formation of identical products (NIB-red) during chemical as well as NTR−aided enzymatic reduction in the presence of NADH. The potential fluorescence imaging of hypoxia based on NTR-mediated reduction of NIB is confirmed using in-vitro cell culture experiments using human breast cancer (MCF−7) cells, which displayed a significant change in the fluorescence colour and intensity at low NIB concentration within a short incubation period in hypoxic conditions. Graphical abstract


HPB ◽  
2016 ◽  
Vol 18 ◽  
pp. e837
Author(s):  
B. Kong ◽  
T. Cheng ◽  
I. Regel ◽  
S. Raulefs ◽  
H. Friess ◽  
...  

2020 ◽  
Vol 2 (1) ◽  
pp. 101-112
Author(s):  
Wu Aixia ◽  
Zhou Ying ◽  
Tommy Tanu Wijaya

With the deepening of China's educational reform, the evaluation of teaching quality has become an important aspect of teaching reform.And the evaluation of students'learning quality is an important part of teaching evaluation. Research on it will help to improve the teaching quality of our country and promote the overall improvement of students' morality, intelligence, physical fitness and beauty.Therefore, this study takes 108 literatures related to the study of learning quality evaluation in China as the research object, uses content analysis method, carries out statistical analysis on the annual number of literatures, Journal distribution, author status, paper influence, research content, etc., analyzes the current situation and existing problems of the study of learning quality evaluation in China, and puts forward the need for further deepening.On the basis of these questions, possible future research directions are proposed.


2021 ◽  
Author(s):  
Anna Skwarska ◽  
Ewen Calder ◽  
Deborah Sneddon ◽  
Hannah Bolland ◽  
Maria Odyniec ◽  
...  

Tumor hypoxia is associated with therapy resistance and poor patient prognosis. Hypoxia-activated prodrugs, designed to selectively target hypoxic cells while sparing normal tissue, represent a promising treatment strategy. We report the pre-clinical efficacy of 1-methyl-2-nitroimidazole panobinostat (NI-Pano, CH-03), a novel bioreductive version of the clinically used lysine deacetylase inhibitor, panobinostat. NI-Pano was stable in normoxic (21% oxygen) conditions and underwent NADPH-CYP-mediated enzymatic bioreduction to release panobinostat in hypoxia (<0.1% oxygen). Treatment of cells grown in both 2D and 3D with NI-Pano increased acetylation of histone H3 at lysine 9, induced apoptosis and decreased clonogenic survival. Importantly, NI-Pano exhibited growth delay effects as a single agent in tumor xenografts. Pharmacokinetic analysis confirmed the presence of sub- micromolar concentrations of panobinostat in hypoxic mouse xenografts, but not in circulating plasma or kidneys. Together, our preclinical results provide a strong mechanistic rationale for the clinical development of NI-Pano for selective targeting of hypoxic tumors.<br>


2021 ◽  
Author(s):  
Xin Peng ◽  
Shaolu Zhang ◽  
Wenhui Jiao ◽  
Zhenxing Zhong ◽  
Yuqi Yang ◽  
...  

Abstract Background: The critical role of phosphoinositide 3-kinase (PI3K) activation in tumor cell biology has prompted massive efforts to develop PI3K inhibitors (PI3Kis) for cancer therapy. However, recent results from clinical trials have shown only a modest therapeutic efficacy of single-agent PI3Kis in solid tumors. Targeting autophagy has controversial context-dependent effects in cancer treatment. As a FDA-approved lysosomotropic agent, hydroxychloroquine (HCQ) has been well tested as an autophagy inhibitor in preclinical models. Here, we elucidated the novel mechanism of HCQ alone or in combination with PI3Ki BKM120 in the treatment of cancer.Methods: The antitumor effects of HCQ and BKM120 on three different types of tumor cells were assessed by in vitro PrestoBlue assay, colony formation assay and in vivo zebrafish and nude mouse xenograft models. The involved molecular mechanisms were investigated by MDC staining, LC3 puncta formation assay, immunofluorescent assay, flow cytometric analysis of apoptosis and ROS, qRT-PCR, Western blot, comet assay, homologous recombination (HR) assay and immunohistochemical staining. Results: HCQ significantly sensitized cancer cells to BKM120 in vitro and in vivo. Interestingly, the sensitization mediated by HCQ could not be phenocopied by treatment with other autophagy inhibitors (Spautin-1, 3-MA and bafilomycin A1) or knockdown of the essential autophagy genes Atg5/Atg7, suggesting that the sensitizing effect might be mediated independent of autophagy status. Mechanistically, HCQ induced ROS production and activated the transcription factor NRF2. In contrast, BKM120 prevented the elimination of ROS by inactivation of NRF2, leading to accumulation of DNA damage. In addition, HCQ activated ATM to enhance HR repair, a high-fidelity repair for DNA double-strand breaks (DSBs) in cells, while BKM120 inhibited HR repair by blocking the phosphorylation of ATM and the expression of BRCA1/2 and Rad51. Conclusions: Our study revealed that HCQ and BKM120 synergistically increased DSBs in tumor cells and therefore augmented apoptosis, resulting in enhanced antitumor efficacy. Our findings provide a new insight into how HCQ exhibits antitumor efficacy and synergizes with PI3Ki BKM120, and warn that one should consider the “off target” effects of HCQ when used as autophagy inhibitor in the clinical treatment of cancer.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Simeng Zhang ◽  
Zhongyan Hua ◽  
Gen Ba ◽  
Ning Xu ◽  
Jianing Miao ◽  
...  

Abstract Background Neuroblastoma (NB) is a common solid malignancy in children that is associated with a poor prognosis. Although the novel small molecular compound Dimethylaminomicheliolide (DMAMCL) has been shown to induce cell death in some tumors, little is known about its role in NB. Methods We examined the effect of DMAMCL on four NB cell lines (NPG, AS, KCNR, BE2). Cellular confluence, survival, apoptosis, and glycolysis were detected using Incucyte ZOOM, CCK-8 assays, Annexin V-PE/7-AAD flow cytometry, and Seahorse XFe96, respectively. Synergistic effects between agents were evaluated using CompuSyn and the effect of DMAMCL in vivo was evaluated using a xenograft mouse model. Phosphofructokinase-1, liver type (PFKL) expression was up- and down-regulated using overexpression plasmids or siRNA. Results When administered as a single agent, DMAMCL decreased cell proliferation in a time- and dose-dependent manner, increased the percentage of cells in SubG1 phase, and induced apoptosis in vitro, as well as inhibiting tumor growth and prolonging survival in tumor-bearing mice (NGP, BE2) in vivo. In addition, DMAMCL exerted synergistic effects when combined with etoposide or cisplatin in vitro and displayed increased antitumor effects when combined with etoposide in vivo compared to either agent alone. Mechanistically, DMAMCL suppressed aerobic glycolysis by decreasing glucose consumption, lactate excretion, and ATP production, as well as reducing the expression of PFKL, a key glycolysis enzyme, in vitro and in vivo. Furthermore, PFKL overexpression attenuated DMAMCL-induced cell death, whereas PFKL silencing promoted NB cell death. Conclusions The results of this study suggest that DMAMCL exerts antitumor effects on NB both in vitro and in vivo by suppressing aerobic glycolysis and that PFKL could be a potential target of DMAMCL in NB.


2017 ◽  
pp. 304-310
Author(s):  
Riitta Hari ◽  
Aina Puce

This chapter summarizes some relative advantages and disadvantages of MEG and EEG, most of which have been previously elaborated. MEG and EEG are the two sides of the same coin and provide complementary information about the human brain’s neurodynamics. The combined use of MEG or EEG together and with other noninvasive methods used to study human brain function is advocated to be important for future research in systems and cognitive/social neuroscience. This chapter also examines combined use and interpretation of MEG/EEG with MRI/fMRI, and performing EEG recordings during non-invasive brain stimulation.


1986 ◽  
Vol 4 (3) ◽  
pp. 425-439 ◽  
Author(s):  
R J Cersosimo ◽  
W K Hong

Epirubicin (4'-epidoxorubicin) is an antineoplastic agent derived from doxorubicin. The compounds differ in the configuration of the hydroxyl group at the 4' position. Epirubicin, like doxorubicin, exerts its antitumor effects by interference with the synthesis and function of DNA and is most active during the S phase of the cell cycle. Epirubicin is administered by intravenous (IV) injection. It is metabolized by the liver and primarily eliminated in the bile. About 10% of the drug is eliminated in the urine. Dosage adjustments are recommended for patients with liver metastases or elevated liver function tests. The elimination half-life of epirubicin is 30 to 40 hours. Clinical studies indicate activity in breast cancer, non-Hodgkin's lymphomas, ovarian cancer, soft-tissue sarcomas, and pancreatic cancer. There is also evidence of activity against gastric cancer, small-cell lung cancer, and acute leukemia. Epirubicin has limited activity as a single agent against head and neck tumors or non-small-cell lung cancer, but may be beneficial in combination with other agents. The overall activity of epirubicin appears to be comparable with that of doxorubicin. However, more studies are needed to define its role in combination chemotherapeutic regimens. The acute dose-limiting toxicity of epirubicin is myelosuppression. Nausea, vomiting, and alopecia are also common. Epirubicin may cause transient cardiac arrhythmias and alterations of the electrocardiogram. Chronic therapy is limited, but available data indicate that epirubicin can be administered in higher cumulative doses than doxorubicin before cardiotoxicity limits further therapy.


2009 ◽  
Vol 27 (2) ◽  
pp. 193-198 ◽  
Author(s):  
Brian M. Wolpin ◽  
Aram F. Hezel ◽  
Thomas Abrams ◽  
Lawrence S. Blaszkowsky ◽  
Jeffrey A. Meyerhardt ◽  
...  

PurposeThe PI3K/Akt/mTOR pathway is activated in the majority of pancreatic cancers, and inhibition of this pathway has antitumor effects in preclinical studies. We performed a multi-institutional, single-arm, phase II study of RAD001(everolimus), an oral inhibitor of mTOR, in patients who experienced treatment failure on first-line therapy with gemcitabine.Patients and MethodsThirty-three patients with gemcitabine-refractory, metastatic pancreatic cancer were treated continuously with RAD001 at 10 mg daily. Prior treatment with fluorouracil in the perioperative setting was allowed. Patients were observed for toxicity, treatment response, and survival.ResultsTreatment with single-agent RAD001 was well-tolerated; the most common adverse events were mild hyperglycemia and thrombocytopenia. No patients were removed from the study because of drug-related adverse events. No complete or partial treatment responses were noted, and only seven patients (21%) had stable disease at the first restaging scans performed at 2 months. Median progression-free survival and overall survival were 1.8 months and 4.5 months, respectively. One patient (3%) had a biochemical response, defined as ≥ 50% reduction in serum CA19-9.ConclusionAlthough well-tolerated, RAD001 administered as a single-agent had minimal clinical activity in patients with gemcitabine-refractory, metastatic pancreatic cancer. Future studies in metastatic pancreatic cancer should assess the combination of mTOR inhibitors with other agents and/or examine inhibitors of other components of the PI3K/Akt/mTOR pathway.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Fan Shi ◽  
Dan Luo ◽  
Xuexiao Zhou ◽  
Qiaozhen Sun ◽  
Pei Shen ◽  
...  

AbstractAutophagy has a complex dual role in tumor survival or cell death owning to that is an evolutionarily conserved catabolic mechanism and provides the cells with a sustainable source of biomolecules and energy for the maintenance of homeostasis under stressful conditions such as tumor microenvironment. Hyperthermia is a rapidly growing field in cancer therapy and many advances have been made in understanding and applying the mechanisms of hyperthermia. The shallow oral and maxillofacial position and its abundant blood supply are favorable for the use of hyperthermia. However, the relationship between hyperthermia and autophagy has not been examined of oral squamous cell carcinoma (OSCC) in the tumor hypoxia microenvironment. Here, the expression level of autophagy relative genes is examined to explore autophagy effect on the responses of hyperthermia, hypoxia, and innutrition tumor microenvironment. It is founded that hyperthermia and hypoxia cause autophagy in starvation conditions; further, in hypoxia and innutrition tumor microenvironment, hyperthermia combines YC-1 and 3-MA could inhibit HIF-1α/BNIP3/Beclin1 signal pathway and decrease the secretion of HMGB1; moreover, the cell apoptosis rate increases with an inhibited of cell migration capacity. Thus, the present study demonstrated that combined use of YC-1 and 3-MA might increase the death of tumor cells in physiological and hyperthermic conditions, which could be relevant with the inhibition of autophagy in OSCC tumor cells under hypoxia microenvironment in vitro, which offers new insight into the therapy of OSCC and its application in treating others study carcinomas.


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