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SLAS Discovery : Advancing Life... Jan 2022In solid tumors like head and neck cancer (HNC), chronic and acute hypoxia have serious adverse clinical consequences including poorer overall patient prognosis,...
In solid tumors like head and neck cancer (HNC), chronic and acute hypoxia have serious adverse clinical consequences including poorer overall patient prognosis, enhanced metastasis, increased genomic instability, and resistance to radiation-, chemo-, or immuno-therapies. However, cells in the two-dimensional monolayer cultures typically used for cancer drug discovery experience 20%-21% O levels (normoxic) which are 4-fold higher than O levels in normal tissues and ≥10-fold higher than in the hypoxic regions of solid tumors. The oxygen electrodes, exogenous bio-reductive markers, and increased expression of endogenous hypoxia-regulated proteins like HIF-1α generally used to mark hypoxic regions in solid tumors are impractical in large sample numbers and longitudinal studies. We used a novel homogeneous live-cell permeant HypoxiTRAK™ (HPTK) molecular probe compatible with high content imaging detection, analysis, and throughput to identify and quantify hypoxia levels in live HNC multicellular tumor spheroid (MCTS) cultures over time. Accumulation of fluorescence HPTK metabolite in live normoxic HNC MCTS cultures correlated with hypoxia detection by both pimonidazole and HIF-1α staining. In HNC MCTSs, hypoxic cytotoxicity ratios for the hypoxia activated prodrugs (HAP) evofosfamide and tirapazamine were much smaller than have been reported for uniformly hypoxic 2D monolayers in gas chambers, and many viable cells remained after HAP exposure. Cells in solid tumors and MCTSs experience three distinct O microenvironments dictated by their distances from blood vessels or MCTS surfaces, respectively; oxic, hypoxic, or intermediate levels of hypoxia. These studies support the application of more physiologically relevant in vitro 3D models that recapitulate the heterogeneous microenvironments of solid tumors for preclinical cancer drug discovery.
Topics: Antineoplastic Agents; Head and Neck Neoplasms; Humans; Hypoxia; Spheroids, Cellular; Squamous Cell Carcinoma of Head and Neck; Tumor Microenvironment
PubMed: 35058175
DOI: 10.1016/j.slasd.2021.10.008 -
International Journal of Molecular... Mar 2021We investigate dissociative electron attachment to tirapazamine through a crossed electron-molecule beam experiment and quantum chemical calculations. After the electron...
We investigate dissociative electron attachment to tirapazamine through a crossed electron-molecule beam experiment and quantum chemical calculations. After the electron is attached and the resulting anion reaches the first excited state, D, we suggest a fast transition into the ground electronic state through a conical intersection with a distorted triazine ring that almost coincides with the minimum in the D state. Through analysis of all observed dissociative pathways producing heavier ions (90-161 u), we consider the predissociation of an OH radical with possible roaming mechanism to be the common first step. This destabilizes the triazine ring and leads to dissociation of highly stable nitrogen-containing species. The benzene ring is not altered during the process. Dissociation of small anionic fragments (NO, CN, CN, NH, O) cannot be conclusively linked to the OH predissociation mechanism; however, they again do not require dissociation of the benzene ring.
Topics: Algorithms; Anions; Electrons; Models, Chemical; Radiation-Sensitizing Agents; Tirapazamine
PubMed: 33808887
DOI: 10.3390/ijms22063159 -
Science Advances Mar 2021Various cancers treated with cisplatin almost invariably develop drug resistance that is frequently caused by substantial DNA repair. We searched for acquired...
Various cancers treated with cisplatin almost invariably develop drug resistance that is frequently caused by substantial DNA repair. We searched for acquired vulnerabilities of cisplatin-resistant cancers to identify undiscovered therapy. We herein found that cisplatin resistance of cancer cells comes at a fitness cost of increased intracellular hypoxia. Then, we conceived an inspired strategy to combat the tumor drug resistance by exploiting the increased intracellular hypoxia that occurs as the cells develop drug resistance. Here, we constructed a hypoxia-amplifying DNA repair-inhibiting liposomal nanomedicine (denoted as HYDRI NM), which is formulated from a platinum(IV) prodrug as a building block and payloads of glucose oxidase (GOx) and hypoxia-activatable tirapazamine (TPZ). In studies on clinically relevant models, including patient-derived organoids and patient-derived xenograft tumors, the HYDRI NM is able to effectively suppress the growth of cisplatin-resistant tumors. Thus, this study provides clinical proof of concept for the therapy identified here.
Topics: Antineoplastic Agents; Cell Line, Tumor; Cisplatin; DNA Repair; Humans; Hypoxia; Nanomedicine; Neoplasms; Tirapazamine
PubMed: 33771859
DOI: 10.1126/sciadv.abc5267 -
Frontiers in Bioengineering and... 2023Cancer selectivity, including targeted internalization and accelerated drug release in tumor cells, remains a major challenge for designing novel stimuli-responsive...
Cancer selectivity, including targeted internalization and accelerated drug release in tumor cells, remains a major challenge for designing novel stimuli-responsive nanocarriers to promote therapeutic efficacy. The hypoxic microenvironment created by photodynamic therapy (PDT) is believed to play a critical role in chemoresistance. We construct dual-responsive carriers (NP) that encapsulate the photosensitizer chlorin e6 (Ce6) and hypoxia-activated prodrug tirapazamine (TPZ) to enable efficient PDT and PDT-boosted hypoxia-activated chemotherapy. Due to TAT masking, NP prolonged payload circulation in the bloodstream, and selective tumor cell uptake occurred via acidity-triggered TAT presentation. PDT was performed with a spatially controlled 660-nm laser to enable precise cell killing and exacerbate hypoxia. Hypoxia-responsive conversion of the hydrophobic NI moiety led to the disassembly of NP, facilitating TPZ release. TPZ was reduced to cytotoxic radicals under hypoxic conditions, contributing to the chemotherapeutic cascade. This work offers a sophisticated strategy for programmed chemo-PDT.
PubMed: 37362218
DOI: 10.3389/fbioe.2023.1197404 -
Drug Delivery Dec 2022Photodynamic therapy (PDT) has been applied in cancer treatment by utilizing reactive oxygen species (ROS) to kill cancer cells. However, the effectiveness of PDT is...
Photodynamic therapy (PDT) has been applied in cancer treatment by utilizing reactive oxygen species (ROS) to kill cancer cells. However, the effectiveness of PDT is greatly reduced due to local hypoxia. Hypoxic activated chemotherapy combined with PDT is expected to be a novel strategy to enhance anti-cancer therapy. Herein, a novel liposome (LCT) incorporated with photosensitizer (PS) and bioreductive prodrugs was developed for PDT-activated chemotherapy. In the design, CyI, an iodinated cyanine dye, which could simultaneously generate enhanced ROS and heat than other commonly used cyanine dyes, was loaded into the lipid bilayer; while tirapazamine (TPZ), a hypoxia-activated prodrug was encapsulated in the hydrophilic nucleus. Upon appropriate near-infrared (NIR) irradiation, CyI could simultaneously produce ROS and heat for synergistic PDT and photothermal therapy (PTT), as well as provide fluorescence signals for precise real-time imaging. Meanwhile, the continuous consumption of oxygen would result in a hypoxia microenvironment, further activating TPZ free radicals for chemotherapy, which could induce DNA double-strand breakage and chromosome aberration. Moreover, the prepared LCT could stimulate acute immune response through PDT activation, leading to synergistic PDT/PTT/chemo/immunotherapy to kill cancer cells and reduce tumor metastasis. Both and results demonstrated improved anticancer efficacy of LCT compared with traditional PDT or chemotherapy. It is expected that these iodinated cyanine dyes-based liposomes will provide a powerful and versatile theranostic strategy for tumor target phototherapy and PDT-induced chemotherapy.
Topics: Animals; Antineoplastic Agents; Cell Survival; Chemistry, Pharmaceutical; Chromosome Aberrations; DNA Damage; Drug Carriers; Drug Liberation; Hypoxia; Liposomes; Mice; Mice, Inbred BALB C; Nanoparticle Drug Delivery System; Particle Size; Photosensitizing Agents; Phototherapy; Reactive Oxygen Species; Surface Properties; Tirapazamine; Xenograft Model Antitumor Assays
PubMed: 35001784
DOI: 10.1080/10717544.2021.2023701 -
Cancer Aug 2019The purpose of this study was to evaluate risk and response-based multi-agent therapy for patients with rhabdomyosarcoma (RMS) at first relapse.
BACKGROUND
The purpose of this study was to evaluate risk and response-based multi-agent therapy for patients with rhabdomyosarcoma (RMS) at first relapse.
METHODS
Patients with RMS and measurable disease at first relapse with unfavorable-risk (UR) features were randomized to a 6-week phase 2 window with 1 of 2 treatment schedules of irinotecan with vincristine (VI) (previously reported). Those with at least a partial response to VI continued to receive 44 weeks of multi-agent chemotherapy including the assigned VI regimen. UR patients who did not have measurable disease at study entry, did not have a radiographic response after the VI window, or declined VI window therapy received 31 weeks of multi-agent chemotherapy including tirapazamine (TPZ) at weeks 1, 4, 10, 19, and 28. Favorable-risk (FR) patients received 31 weeks of the same multi-agent chemotherapy without VI and TPZ.
RESULTS
One hundred thirty-six eligible patients were enrolled. For 61 patients not responding to VI, the 3-year failure-free survival (FFS) and overall survival (OS) rates were 17% (95% confidence interval [CI], 8%-29%) and 24% (13%-37%), respectively. For 30 UR patients not treated with VI, the 3-year FFS and OS rates were 21% (8%-37%) and 39% (20%-57%), respectively. FR patients had 3-year FFS and OS rates of 79% (47%-93%) and 84% (50%-96%), respectively. There were no unexpected toxicities.
CONCLUSIONS
Patients with UR RMS at first relapse or disease progression have a poor prognosis when they are treated with this multi-agent therapy, whereas FR patients have a higher chance of being cured with second-line therapy.
Topics: Child; Disease Progression; Female; Humans; Male; Recurrence; Rhabdomyosarcoma; Risk Factors; Survival Analysis
PubMed: 31067356
DOI: 10.1002/cncr.32122 -
Pharmaceutics Jan 2022Oxygen dependence and anabatic hypoxia are the major factors responsible for the poor outcome of photodynamic therapy (PDT) against cancer. Combining of PDT and...
Oxygen dependence and anabatic hypoxia are the major factors responsible for the poor outcome of photodynamic therapy (PDT) against cancer. Combining of PDT and hypoxia-activatable bioreductive therapy has achieved remarkably improved antitumor efficacy compared to single PDT modality. However, controllable release and activation of prodrug and safety profiles of nanocarrier are still challenging in the combined PDT/hypoxia-triggered bioreductive therapy. Herein, we developed a near infrared (NIR) light-decomposable nanomicelle, consisting of PEGylated cypate (pCy) and mPEG-polylactic acid (mPEG-PLA) for controllable delivery of hypoxia-activated bioreductive prodrug (tirapazamine, TPZ) (designated TPZ@pCy), for combating metastatic breast cancer via hypoxia-enhanced phototherapies. TPZ@pCy was prepared by facile nanoprecipitation method, with good colloidal stability, excellent photodynamic and photothermal potency, favorable light-decomposability and subsequent release and activation of TPZ under irradiation. In vitro experiments demonstrated that TPZ@pCy could be quickly internalized by breast cancer cells, leading to remarkable synergistic tumor cell-killing potential. Additionally, metastatic breast tumor-xenografted mice with systematic administration of TPZ@pCy showed notable tumor accumulation, promoting tumor ablation and lung metastasis inhibition with negligible toxicity upon NIR light illumination. Collectively, our study demonstrates that this versatile light-decomposable polymeric micelle with simultaneous delivery of photosensitizer and bioreductive agent could inhibit tumor growth as well as lung metastasis, representing a promising strategy for potent hypoxia-enhanced phototherapies for combating metastatic breast cancer.
PubMed: 35213986
DOI: 10.3390/pharmaceutics14020253 -
Scientific Reports Feb 2021Tumor tissue contains a continuous distribution of static and dynamically changing oxygen environments with levels ranging from physiologically normal oxygen down to...
Tumor tissue contains a continuous distribution of static and dynamically changing oxygen environments with levels ranging from physiologically normal oxygen down to anoxia. However, in vitro studies are often performed under oxygen levels that are far higher than those found in vivo. A number of devices are available to alter the oxygen environment in cell culture, including designs from our laboratory. However, in our devices and most other designs, changing the media in order to feed or dose cells remains a disruptive factor in maintaining a consistent hypoxic environment. This report presents a novel 96-well plate design that recirculates the local oxygen environment to shield cells during media changes and facilitates toxicity studies of cells cultured under varying oxygen levels. The principle behind the design is presented and the response of human pancreatic cancer PANC-1 cells treated with tirapazamine and doxorubicin under eight different static or cycling oxygen levels was measured. As expected, tirapazamine is progressively more toxic as oxygen levels decrease but retains some toxicity as oxygen is cycled between hypoxic and normoxic levels. Doxorubicin sensitivity is largely unaffected by changing oxygen levels. This technology is ideal for assessing the effects of oxygen as a variable in toxicity screens.
Topics: Cell Culture Techniques; Cell Hypoxia; Cell Line, Tumor; Doxorubicin; High-Throughput Screening Assays; Humans; Neoplasms; Oxygen; Pancreatic Neoplasms; Tirapazamine; Toxicity Tests; Triazines; Tumor Microenvironment
PubMed: 33597640
DOI: 10.1038/s41598-021-83579-1 -
Journal of Hepatocellular Carcinoma 2021Tirapazamine (TPZ) is a hypoxia activated drug that may be synergistic with transarterial embolization (TAE). The primary objective was to evaluate the safety of... (Clinical Trial)
Clinical Trial
BACKGROUND
Tirapazamine (TPZ) is a hypoxia activated drug that may be synergistic with transarterial embolization (TAE). The primary objective was to evaluate the safety of combining TPZ and TAE in patients with unresectable HCC and determine the optimal dose for Phase II.
METHODS
This was a Phase 1 multicenter, open-label, non-randomized trial with a classic 3+3 dose escalation and an expansion cohort in patients with unresectable HCC, Child Pugh A, ECOG 0 or 1. Two initial cohorts consisted of I.V. administration of Tirapazamine followed by superselective TAE while the remaining three cohorts underwent intraarterial administration of Tirapazamine with superselective TAE. Safety and tolerability were assessed using NCI CTCAE 4.0 with clinical, imaging and laboratory examinations including pharmacokinetic (PK) analysis and an electrocardiogram 1 day pre-dose, at 1, 2, 4, 6, 10, and 24 hours post-TPZ infusion and an additional PK at 15- and 30-minutes post-TPZ. Tumor responses were evaluated using mRECIST criteria.
RESULTS
Twenty-seven patients (mean [range] age of 66.4 [37-79] years) with unresectable HCC were enrolled between July 2015 and January 2018. Two patients were lost to follow-up. Mean tumor size was 6.53 cm ± 2.60 cm with a median of two lesions per patient. Dose limiting toxicity and maximum tolerated dose were not reached. The maximal TPZ dose was 10 mg/m I.V. and 20 mg/m I.A. One adverse event (AE) was reported in all patients with fatigue, decreased appetite or pain being most common. Grade 3-5 AE were hypertension and transient elevation of AST/ALT in 70.4% of patients. No serious AE were drug related. Sixty percent (95% CI=38.7-78.9) achieved complete response (CR), and 84% (95% CI=63.9-95.5) had complete and partial response per mRECIST for target lesions.
DISCUSSION
TAE with TPZ was safe and tolerable with encouraging results justifying pursuit of a Phase II trial.
PubMed: 34041204
DOI: 10.2147/JHC.S304275 -
Biomicrofluidics Sep 2019In anticancer drug development, it is important to simultaneously evaluate both the effect of drugs on cell proliferation and their ability to penetrate tissues. To...
In anticancer drug development, it is important to simultaneously evaluate both the effect of drugs on cell proliferation and their ability to penetrate tissues. To realize such an evaluation process, here, we present a compartmentalized tumor spheroid culture system utilizing a thin membrane with a through-hole to conduct localized anticancer treatment of tumor spheroids and monitor spheroid dimensions as an indicator of cell proliferation. The system is based on a commercialized Boyden chamber plate; a through-hole was bored through a porous membrane of the chamber, and the pre-existing 0.4 m membrane pores were filled with parylene C. A HepG2 spheroid was immobilized onto the through-hole, separating the upper and lower compartments. Fluorescein (to verify the isolation between the compartments) and tirapazamine (TPZ; to treat only the lower part of the spheroid) were added to the upper and lower compartments, respectively. Since the transportation of fluorescein was blocked during treatment, i.e., the upper and lower compartments were isolated, it was confirmed that localized TPZ treatment was successfully conducted using the developed system. The effect of localized TPZ treatment on cell proliferation was estimated by measuring the maximum horizontal cross-sectional areas in the upper and lower parts of the spheroid by microscopic observations. This system can, thus, be used to perform localized anticancer drug treatment of tumor spheroids and evaluate the effect of drugs on cell proliferation.
PubMed: 31893010
DOI: 10.1063/1.5125650