-
Pharmaceutics Apr 2022Tumor hypoxia is a hallmark of solid tumors and emerged as the therapeutic target for cancer treatments, such as a prodrug Tirapazamine (TPZ) activated in hypoxia. To...
Tumor hypoxia is a hallmark of solid tumors and emerged as the therapeutic target for cancer treatments, such as a prodrug Tirapazamine (TPZ) activated in hypoxia. To increase tumor accumulation, gold nanoparticles (GNPs) were selected to conjugate with TPZ. In this study, we successfully formulated and assessed the biochemical and therapeutic roles of the conjugated gold nanoparticles-Tirapazamine (GNPs-TPZ) on therapeutic assessments of MKN45-induced xenograft animal model. The results indicated that GNPs-TPZ was a potential nanomedicine for selectively targeting hypoxia tumors coupled with decreased side effects on healthy tissue or organs. TPZ significantly reduced cell viability of hypoxic gastric cancer MKN45 cells, but not in cells incubated in normoxia condition. For improving tumor targeting efficiency, furthermore, the GNPs drug carrier was conjugated to TPZ via biding mediator bovine serum albumin (BSA), and we demonstrated that this conjugated GNPs-TPZ retained the unique characteristics of hypoxic toxin and possessed the adequate feature of systemic bio-distributions in animals. GNPs-TPZ nanoparticles revealed their superior affinity to hypoxia tumors in the MKN45 xenograft. Moreover, GNPs-TPZ treatments did not significantly alter the biochemical parameters of blood samples acquired from animals. Taken together, TPZ, a prodrug activated by hypoxia, was conjugated with GNPs, whereas BSA severed as an excellent binding agent for preparing the conjugated GNPs-TPZ nanomedicines. We demonstrated that GNPs-TPZ enhanced tumor targeting, resulting in higher therapeutic efficacy compared to TPZ. We suggest that it may sever as an adjuvant treatment or combined therapy with other chemotherapeutics for the treatment of cancer patients in the future.
PubMed: 35456681
DOI: 10.3390/pharmaceutics14040847 -
Journal of Pharmacy & Bioallied Sciences 2021Tumor hypoxia, a predominant feature of solid tumor produces drug resistance that significantly impacts a patient's clinical outcomes. Hypoxia-inducible factor 1-alpha...
OBJECTIVE
Tumor hypoxia, a predominant feature of solid tumor produces drug resistance that significantly impacts a patient's clinical outcomes. Hypoxia-inducible factor 1-alpha (HIF1α) is the major mutation involved in establishing the microenvironment. As a consequence of its involvement in pathways that enable rapid tumor growth, it creates resistance to chemotherapeutic treatments. The propensity of medications to demonstrate drug action often diverges according to the genetic composition. The aim of this study is therefore to examine the effect of population-dependent drug response variations using mutation models.
METHODS
Genetic variations distinctive to major super-populations were identified, and the mutated gene was acquired as a result of incorporating the variants. The mutated gene sequence was transcribed and translated to obtain the target amino acid sequence. To investigate the effects of mutations, protein models were developed using homology modeling. The target templates for the backbone structure were identified by characterization of primary and secondary protein structures. The modeled proteins were then validated for structural confirmation and flexibility. Potential models were used for interaction studies with hypoxia-specific molecules (tirapazamine, apaziquone, and ENMD) using docking analysis. To verify their stability under pre-defined dynamic conditions, the complexes were subjected to molecular dynamics simulation.
RESULTS
The current research models demonstrate with the pharmacogenomic-based mutation of HIF1α the impact of individual variants in altering the person-specific drug response under tumor hypoxic conditions. It also elucidates that the therapeutic effect is altered concerning population-dependent genetic changes in the individual.
CONCLUSION
The study, therefore, asserts the need to set up a personalized drug design approach to enhance tumor hypoxia treatment efficacy.
PubMed: 35399804
DOI: 10.4103/jpbs.jpbs_766_21 -
Frontiers in Bioengineering and... 2022In recent years, sonodynamic therapy (SDT) has been widely developed for cancer research as a promising non-invasive therapeutic strategy. Here, we synthesized zeolitic...
In recent years, sonodynamic therapy (SDT) has been widely developed for cancer research as a promising non-invasive therapeutic strategy. Here, we synthesized zeolitic imidazole frameworks-8 (ZIF-8) and utilized its properties to encapsulate hydrophobic Chlorin e6 (Ce6) and hydrophilic tirapazamine (TPZ) for a synergistic sonodynamic chemotherapy, which was also accompanied by the modification of cytomembrane of gastric cancer (GC) cells. Thus, we enabled the biomimetic property to achieve targeted delivery. Ce6-mediated SDT, in combination with ultrasound irradiation, could target the release of reactive oxygen species (ROS) to aggravate further hypoxia and activate TPZ. Combining these effects could induce the pyroptosis of GC cells and play the anti-tumor function, which could provide a potential therapeutic method for cancer therapy.
PubMed: 35265591
DOI: 10.3389/fbioe.2022.796820 -
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 -
Molecules (Basel, Switzerland) Jan 2022Hypoxia in tumors results in resistance to both chemotherapy and radiotherapy treatments but affords an environment in which hypoxia-activated prodrugs (HAP) are...
Hypoxia in tumors results in resistance to both chemotherapy and radiotherapy treatments but affords an environment in which hypoxia-activated prodrugs (HAP) are activated upon bioreduction to release targeted cytotoxins. The benzotriazine 1,4-di--oxide (BTO) HAP, tirapazamine (TPZ, ), has undergone extensive clinical evaluation in combination with radiotherapy to assist in the killing of hypoxic tumor cells. Although compound did not gain approval for clinical use, it has spurred on the development of other BTOs, such as the 3-alkyl analogue, SN30000, . There is general agreement that the cytotoxin(s) from BTOs arise from the one-electron reduced form of the compounds. Identifying the cytotoxic radicals, and whether they play a role in the selective killing of hypoxic tumor cells, is important for continued development of the BTO class of anticancer prodrugs. In this study, nitrone spin-traps, combined with electron spin resonance, give evidence for the formation of aryl radicals from compounds , and 3-phenyl analogues, compounds and , which form carbon C-centered radicals. In addition, high concentrations of DEPMPO (5-(diethoxyphosphoryl)-5-methyl-1-pyrroline -oxide) spin-trap the •OH radical. The combination of spin-traps with high concentrations of DMSO and methanol also give evidence for the involvement of strongly oxidizing radicals. The failure to spin-trap methyl radicals with PBN (--butylphenylnitrone) on the bioreduction of compound , in the presence of DMSO, implies that free •OH radicals are not released from the protonated radical anions of compound . The spin-trapping of •OH radicals by high concentrations of DEPMPO, and the radical species arising from DMSO and methanol give both direct and indirect evidence for the scavenging of •OH radicals that are involved in an intramolecular process. Hypoxia-selective cytotoxicity is not related to the formation of aryl radicals from the BTO compounds as they are associated with high aerobic cytotoxicity.
Topics: Antineoplastic Agents; Cell Survival; Electrons; Free Radicals; HCT116 Cells; HT29 Cells; Humans; Hydroxyl Radical; Neoplasms; Spin Trapping; Triazines
PubMed: 35164077
DOI: 10.3390/molecules27030812 -
Journal of Nanobiotechnology Jan 2022Chemodynamic therapy is a promising cancer treatment with specific therapeutic effect at tumor sites, as toxic hydroxyl radical (·OH) could only be generated by Fenton...
BACKGROUND
Chemodynamic therapy is a promising cancer treatment with specific therapeutic effect at tumor sites, as toxic hydroxyl radical (·OH) could only be generated by Fenton or Fenton-like reaction in the tumor microenvironment (TME) with low pH and high level of endogenous hydrogen peroxide. However, the low concentration of catalytic metal ions, excessive glutathione (GSH) and aggressive hypoxia at tumor site seriously restrict the curative outcomes of conventional chemodynamic therapy.
RESULTS
In this study, polyethylene glycol-phenylboronic acid (PEG-PBA)-modified generation 5 (G5) poly(amidoamine) (PAMAM) dendrimers were synthesized as a targeted nanocarrier to chelate Cu(II) and then encapsulate hypoxia-sensitive drug tirapazamine (TPZ) by the formation of hydrophobic Cu(II)/TPZ complex for hypoxia-enhanced chemo/chemodynamic therapy. The formed G5.NHAc-PEG-PBA@Cu(II)/TPZ (GPPCT) nanoplatform has good stability and hemocompatibility, and could release Cu(II) ions and TPZ quickly in weakly acidic tumor sites via pH-sensitive dissociation of Cu(II)/TPZ. In vitro experiments showed that the GPPCT nanoplatforms can efficiently target murine breast cancer cells (4T1) cells overexpressing sialic acid residues, and show a significantly enhanced inhibitory effect on hypoxic cells by the activation of TPZ. The excessive GSH in tumors could be depleted by the reduction of Cu(II) to Cu(I), and abundant of toxic ·OH would be generated in tumor cells by Fenton reaction for chemodynamic therapy. In vivo experiments demonstrated that the GPPCT nanoplatform could specifically accumulate at tumors, effectively inhibit the growth and metastasis of tumors by the combination of CDT and chemotherapy, and be metabolized with no systemic toxicity.
CONCLUSIONS
The targeted GPPCT nanoplatform may represent an effective model for the synergistic inhibition of different tumor types by hypoxia-enhanced chemo/chemodynamic therapy.
Topics: Animals; Antineoplastic Agents; Cell Hypoxia; Dendrimers; Mice; Nanostructures; Tirapazamine; Tumor Microenvironment
PubMed: 35062953
DOI: 10.1186/s12951-022-01247-6 -
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 -
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 -
Nano-micro Letters Dec 2021The enzyme-mediated elevation of reactive oxygen species (ROS) at the tumor sites has become an emerging strategy for regulating intracellular redox status for...
The enzyme-mediated elevation of reactive oxygen species (ROS) at the tumor sites has become an emerging strategy for regulating intracellular redox status for anticancer treatment. Herein, we proposed a camouflaged bionic cascaded-enzyme nanoreactor based on TiC nanosheets for combined tumor enzyme dynamic therapy (EDT), phototherapy and deoxygenation-activated chemotherapy. Briefly, glucose oxidase (GOX) and chloroperoxidase (CPO) were chemically conjugated onto TiC nanosheets, where the deoxygenation-activated drug tirapazamine (TPZ) was also loaded, and the TiC-GOX-CPO/TPZ (TGCT) was embedded into nanosized cancer cell-derived membrane vesicles with high-expressed CD47 (mTGCT). Due to biomimetic membrane camouflage and CD47 overexpression, mTGCT exhibited superior immune escape and homologous targeting capacities, which could effectively enhance the tumor preferential targeting and internalization. Once internalized into tumor cells, the cascade reaction of GOX and CPO could generate HClO for efficient EDT. Simultaneously, additional laser irradiation could accelerate the enzymic-catalytic reaction rate and increase the generation of singlet oxygen (O). Furthermore, local hypoxia environment with the oxygen depletion by EDT would activate deoxygenation-sensitive prodrug for additional chemotherapy. Consequently, mTGCT exhibits amplified synergistic therapeutic effects of tumor phototherapy, EDT and chemotherapy for efficient tumor inhibition. This intelligent cascaded-enzyme nanoreactor provides a promising approach to achieve concurrent and significant antitumor therapy.
PubMed: 34882297
DOI: 10.1007/s40820-021-00761-w -
Biomolecules Oct 2021Tumour hypoxia is significantly correlated with patient survival and treatment outcomes. At the molecular level, hypoxia is a major driving factor for tumour progression... (Review)
Review
Tumour hypoxia is significantly correlated with patient survival and treatment outcomes. At the molecular level, hypoxia is a major driving factor for tumour progression and aggressiveness. Despite the accumulative scientific and clinical efforts to target hypoxia, there is still a need to find specific treatments for tumour hypoxia. In this review, we discuss a variety of approaches to alter the low oxygen tumour microenvironment or hypoxia pathways including carbogen breathing, hyperthermia, hypoxia-activated prodrugs, tumour metabolism and hypoxia-inducible factor (HIF) inhibitors. The recent advances in technology and biological understanding reveal the importance of revisiting old therapeutic regimens and repurposing their uses clinically.
Topics: Animals; Humans; Prodrugs; Tumor Hypoxia
PubMed: 34827602
DOI: 10.3390/biom11111604