Hypoxic targeting and activating TH-302 loaded transcatheter arterial embolization microsphere

Synthesis and characterization of 3-in-1 multifunctional lipiodol-doped Fe3O4@Poly (diallyl isophthalate) microspheres for arterial embolization, chemotherapy, and imaging

Transcatheter arterial embolization plays a pivotal role in treating various diseases. However, the efficacy of embolization therapy in cancer treatment can be limited by several factors, such as inevitable incomplete or non-target embolization, and the tumor recurrence and metastasis caused by the hypoxic microenvironment. Moreover, it is essential to explore simpler, more economical, and efficient methods for microsphere synthesis. Herein, we achieved one-step photocatalytic synthesis of lipiodol-doped Fe3O4@Poly (diallyliso-phthalate) multifunctional microspheres (IFeD MS) for arterial embolization, chemotherapy, and imaging. The prepared microspheres are in the shape of dried plums, with a particle size of 100-300 μm. Lipiodol demonstrates a certain degree of chemotherapeutic activity, and the incorporation of Fe3O4enables the microspheres to exhibit magnetothermal response and magnetic resonance imaging capabilities. Furthermore, the radiopaque characteristics of both agents provide the microspheres with promising potential for computed tomography and digital radiography imaging. The renal embolization experiment in rabbits demonstrated that IFeD MS achieved significant embolization and chemotherapeutic effects. Biocompatibility experiments revealed that this embolic agent did not induce tissue damage or inflammation beyond the treatment area. Additionally, IFeD MS exhibited promising imaging potential. The results of this study imply that the developed multifunctional embolic agent IFeD MS may have significant potential in transforming tumors previously only suitable for palliative cares into resectable radical treatments.

BCLAF1-induced HIF-1α accumulation under normoxia enhances PD-L1 treatment resistances via BCLAF1-CUL3 complex

Bcl-2-associated transcription factor-1 (BCLAF1), an apoptosis-regulating protein of paramount significance, orchestrates the progression of various malignancies. This study reveals increased BCLAF1 expression in hepatocellular carcinoma (HCC) patients, in whom elevated BCLAF1 levels are linked to escalated tumor grades and diminished survival rates. Moreover, novel BCLAF1 expression is particularly increased in HCC patients who were not sensitive to the combined treatment of atezolizumab and bevacizumab, but not in patients who had tumors that responded to the combined regimen. Notably, overexpression of BCLAF1 increases HCC cell proliferation in vitro and in vivo, while the conditioned medium derived from cells overexpressing BCLAF1 strikingly enhances the tube-formation capacity of human umbilical vein endothelial cells. Furthermore, compelling evidence demonstrates that BCLAF1 attenuates the expression of prolyl hydroxylase domain protein 2 (PHD2) and governs the stability of hypoxia-inducible factor-1α (HIF-1α) under normoxic conditions without exerting any influence on transcription, as determined by Western blot and RT‒qPCR analyses. Subsequently, employing coimmunoprecipitation and immunofluorescence, we validated the reciprocal interaction between BCLAF1 and Cullin 3 (CUL3), through which BCLAF1 actively upregulates the ubiquitination and degradation of PHD2. The Western blot and RT‒qPCR results suggests that programmed death ligand-1 (PD-L1) is one of the downstream responders to HIF-1α in HCC. Thus, we reveal the pivotal role of BCLAF1 in promoting PD-L1 transcription and, through binding to CUL3, in promoting the accumulation of HIF-1α under normoxic conditions, thereby facilitating the ubiquitination and degradation of PHD2.

Drug-Eluting Porous Embolic Microspheres for Trans-Arterial Delivery of Dual Synergistic Anticancer Therapy for the Treatment of Liver Cancer

Blockage of blood supply while administering chemotherapy to tumors, using trans-arterial chemoembolization (TACE), is the most common treatment for intermediate and advanced-stage unresectable Hepatocellular carcinoma (HCC). However, HCC is characterized by a poor prognosis and high recurrence rates (≈30%), partly due to a hypoxic pro-angiogenic and pro-cancerous microenvironment. This study investigates how modifying tissue stress while improving drug exposure in target organs may maximize the therapeutic outcomes. Porous degradable polymeric microspheres (MS) are designed to obtain a gradual occlusion of the hepatic artery that nourishes the liver, while enabling efficient drug perfusion to the tumor site. The fabricated porous MS are introduced intrahepatically and designed to release a combination therapy of Doxorubicin (DOX) and Tirapazamine (TPZ), which is a hypoxia-activated prodrug. Liver cancer cell lines that are treated with the combination therapy under hypoxia reveal a synergic anti-proliferation effect. An orthotopic liver cancer model, based on N1-S1 hepatoma in rats, is used for the efficacy, biodistribution, and safety studies. Porous DOX-TPZ MS are very effective in suppressing tumor growth in rats, and induction tissue necrosis is associated with high intratumor drug concentrations. Porous particles without drugs show some advantages over nonporous particles, suggesting that morphology may affect the treatment outcomes.

TH-302-loaded nanodrug reshapes the hypoxic tumour microenvironment and enhances PD-1 blockade efficacy in gastric cancer

BACKGROUND

Hypoxia, a common characteristic of the tumour microenvironment, is involved in tumour progression and immune evasion. Targeting the hypoxic microenvironment has been implicated as a promising antitumour therapeutic strategy. TH-302 can be selectively activated under hypoxic conditions. However, the effectiveness of TH-302 in gastric cancer combined immunotherapy remains unclear.

METHODS

We designed mPEG-PLGA-encapsulated TH-302 (TH-302 NPs) to target the hypoxic area of tumour tissues. A particle size analyzer was used to measure the average size and zeta potential of TH-302 NPs. The morphology was observed by transmission electron microscopy and scanning electron microscopy. The hypoxic area of tumour tissues was examined by immunofluorescence assays using pimonidazole. Flow cytometry analysis was performed to measure the levels of TNF-α, IFN-γ, and granzyme B. The synergistic antitumour activity of the combination of TH-302 NPs with anti-PD-1 (α-PD-1) therapy was assessed in vitro and in vivo. Haematoxylin and eosin staining of major organs and biochemical indicator detection were performed to investigate the biological safety of TH-302 NPs in vivo.

RESULTS

TH-302 NPs inhibited the proliferation and promoted the apoptosis of gastric cancer cells under hypoxic conditions. In vitro and in vivo experiments confirmed that TH-302 NPs could effectively alleviate tumour hypoxia. TH-302 NPs exhibited high bioavailability, effective tumour-targeting ability and satisfactory biosafety. Moreover, the combination of TH-302 NPs with α-PD-1 significantly improved immunotherapeutic efficacy in vivo. Mechanistically, TH-302 NPs reduced the expression of HIF-1α and PD-L1, facilitated the infiltration of CD8+ T cells and increased the levels of TNF-α, IFN-γ, and granzyme B in tumours, thereby enhancing the efficacy of α-PD-1 therapy.

CONCLUSION

TH-302 NPs alleviated the hypoxic tumour microenvironment and enhanced the efficacy of PD-1 blockade. Our results provide evidence that TH-302 NPs can be used as a safe and effective nanodrug for combined immunotherapy in gastric cancer treatment.

Smart nanoparticles and microbeads for interventional embolization therapy of liver cancer: state of the art

The process of transcatheter arterial chemoembolization is characterized by the ability to accurately deliver chemotherapy drugs with minimal systemic side effects and has become the standard treatment for unresectable intermediate hepatocellular carcinoma (HCC). However, this treatment option still has much room for improvement, one of which may be the introduction of nanomaterials, which exhibit unique functions and can be applied to in vivo tumor imaging and therapy. Several biodegradable and multifunctional nanomaterials and nanobeads have recently been developed and applied in the locoregional treatment of hepatocellular cancer. This review explores recent developments and findings in relation to micro-nano medicines in transarterial therapy for HCC, emerging strategies to improve the efficacy of delivering nano-based medicines, and expounding prospects for clinical applications of nanomaterials.

Prognostic Comparison between cTACE and H101-TACE in Unresectable Hepatocellular Carcinoma (HCC): A Propensity-Score Matching Analysis

Background

Transarterial chemoembolization (TACE) is the most common treatment for patients with HCC who are unsuitable for radical therapies. Conventional TACE (cTACE) takes advantage of the preferential hepatic arterial supply of HCC for the targeted delivery of chemotherapeutic agents suspended in lipiodol, followed by embolization or reduction of arterial flow using various types of particles while sparing the surrounding liver parenchyma. Aims and Objectives. The current study is aimed at comparing the efficacy and safety profiles of transarterial infusion of recombinant human type-5 adenovirus (H101-TACE) with conventional transarterial chemoembolization (cTACE) in patients with unresectable hepatocellular carcinoma (HCC).

Methods

Unresectable HCC patients that received H101-based TACE or cTACE from August 2018 to September 2021 were retrospectively evaluated. Propensity score matching (PSM) has a 1 : 1 ratio to eliminate possible confounder imbalances across cohorts. The main outcome was overall survival (OS), while secondary outcomes were progression-free survival (PFS) and tumor response.

Results

This study included 111 patients classified across two cohorts: the H101-TACE cohort (n = 37) and the cTACE cohort (n = 74). Median OS within the H101-TACE cohort was 9.0 months longer than within the cTACE cohort before PSM (22.1 vs. 13.1 months, P = 0.043) and 9.3 months longer following PSM (22.1 vs. 12.8 months, P = 0.004). The median PFS within the H101-TACE cohort was 3.2 months longer compared to the cTACE cohort before PSM (6.5 vs. 3.3 months, P = 0.046) and 2.5 months after PSM (6.5 vs. 4.0 months, P = 0.012). The disease control rate for H101 and control cohorts was 81.1% and 59.5%, accordingly (P = 0.039).

Conclusion

The present study demonstrated that the H101-TACE is safe and efficient and can considerably enhance prognostic results for unresectable HCC compared to cTACE.

Comparison of the Efficacy Among Transcatheter Arterial Chemoembolization (TACE)-Radiofrequency Ablation Plus Apatinib, TACE Plus Apatinib, and TACE Alone for Hepatocellular Carcinoma: A Retrospective Study

BACKGROUND

This study aimed to investigate the efficacy and safety of apatinib plus transarterial chemoembolization (TACE) and radiofrequency ablation (RFA) in the therapy of hepatocellular carcinoma (HCC) patients.

METHODS

From December 2015 to June 2018, 175 eligible participants were included in our research. Twenty-four patients who received apatinib plus TACE and RFA were categorized as the TACE + RFA-A group, 82 patients who received apatinib plus TACE were categorized as the TACE-A group, and 69 patients who received TACE alone were categorized as the TACE group. Treatment complications, treatment response, overall survival (OS), and time to progression (TTP) were recorded. Survival analyses were compared. Univariate and multivariate Cox analyses were conducted to investigate the predictive factors for OS and TTP. A subgroup analysis was carried out.

RESULTS

The median TTP was 8.0 months (95% CI 6.7-9.3) in the TACE + RFA-A, which was longer than the TACE-A group (6.0 months, 95% CI 4.8-7.2) and TACE group (3.0 months, 95% CI 2.3-3.7); the difference was statistically significant (P < 0.001). The median OS was 23.0 months (95% CI 12.6-33.4) in the TACE + RFA-A group, 18.0 months (95% CI 16.2-19.8) in the TACE-A group, and 8.0 months (95% CI 5.3-10.7) in the TACE group; the difference was statistically significant (P < 0.001). The objective response rate (ORR) was higher in TACE + RFA-A t group (M1, 70.8% vs 65.9% vs. 46.4%, P = 0.023; M3, 58.3% vs. 53.7% vs. 26.1%, P = 0.001). Multivariate Cox analysis demonstrated that treatment strategy and tumor size were independent prognostic factors for the OS and TTP, whereas the Child-Pugh stage was predictive factor of OS. No treatment-related death was observed. The toxicity was comparable between the two groups.

CONCLUSION

TACE combined with RFA plus apatinib is a safe three-modality treatment for the intermediate or advanced HCC, and it demonstrated better efficacy than TACE plus apatinib or TACE alone.

Drug-Eluting Bead Transarterial Chemoembolization versus Conventional Transarterial Chemoembolization Both Combined Apatinib for Hepatocellular Carcinoma: A Retrospective, Propensity-Score Matched Study

Purpose

This study aims to compare the efficacy of drug-eluting bead transarterial chemoembolization (DEB-TACE) versus conventional TACE (cTACE), both combined with apatinib, and to establish predictive nomograms to support individualized survival prediction in hepatocellular carcinoma (HCC) patients.

Patients and Methods

This retrospective study assessed HCC patients from June 2015 to December 2019. Patients were classified as DEB-TACE plus apatinib (D-apatinib) and cTACE plus apatinib (c-apatinib). The endpoints were overall survival (OS) and progression-free survival (PFS). The nomograms were constructed, and the C-index, receiver operating characteristic (ROC) curve, and calibration curves were used to validate the nomograms. Propensity score matching (PSM) analysis was applied to reduce patient selection bias.

Results

A total of 174 patients were included. After PSM analysis, 58 pairs of patients were selected. Before PSM analysis, the median OS and PFS were 21.0 and 8.0 months in the D-apatinib group, respectively, which were better than the 18.0 and 5.0 months observed in the c-apatinib group (P < 0.05). The complete response (CR) rate and objective response rate (ORR) of the D-apatinib group were higher than those of the c-apatinib group. The C-index values of the nomograms in the D-apatinib group and the c-apatinib group were 0.826 and 0.802, and the area under the curve (AUC) values in the ROC curve were 0.934 and 0.892. After PSM analysis, the survival of patients treated with D-apatinib was better than that of patients treated with c-apatinib (P < 0.05). The C-index values were 0.854 and 0.794 in the D-apatinib group and the c-apatinib group, respectively, and the AUC values were 0.960 and 0.890. The incidence of adverse events was higher in the c-apatinib group.

Conclusion

DEB-TACE in combination with apatinib showed better treatment effectiveness for unresectable HCC. The nomograms can identify HCC patients who may benefit most from the treatment.

GLUT1 targeting and hypoxia-activating polymer-drug conjugate-based micelle for tumor chemo-thermal therapy

Purpose

Mitochondria are closely correlated with the proliferation and metastasis of tumor for providing suitable micro-environment and energy supply. Herein, we construct a glucose transporter 1 (GLUT1) targeting and hypoxia activating polyprodrug-based micelle (Glu-PEG-Azo-IR808-S-S-PTX) for mitochondria-specific drug delivery and tumor chemo-thermal therapy.

Results

The micelle was characterized by hypoxia-sensitive PEG outer layer detachment, high photo-thermal conversion efficiency, and glutathione (GSH)-sensitive paclitaxel （PTX） release. It showed GLUT1 specifically cellular uptake and hypoxia-sensitive mitochondria targeting on A549 cell. In vivo fluorescence imaging confirmed the micelle also could selectively accumulate in tumor and its mitochondria on A549 tumor-bearing nude mice. Consequently, it not only exhibited higher cytotoxicity, apoptosis rate, and metastasis inhibition rate on A549 cells, but also better tumor growth and metastasis inhibition rate on tumor-bearing nude mice and lower whole-body toxicity. The mechanism might be caused by destroying mitochondria and down-regulating ATP production.

Conclusion

This study provided a GLUT1 targeting, hypoxia, and reductive responsive nanomedicine that hold the potential to be exploited for tumor therapy.

Evofosfamide Is Effective against Pediatric Aggressive Glioma Cell Lines in Hypoxic Conditions and Potentiates the Effect of Cytotoxic Chemotherapy and Ionizing Radiations

Simple Summary

Despite many therapeutic approaches attempted over the last years, the prognosis of children with high-grade glioma or diffuse intrinsic pontine glioma remains dismal. Hypoxia-activated prodrugs (HAPs) were developed to target hypoxic areas within solid tumors as gliomas. Evofosfamide (Evo) is a 2nd generation HAP exhibiting significant preclinical and clinical activities against adult glioblastoma. We thus investigated the potential of Evo in six pediatric glioma cell lines. Interestingly, we showed that the growth of all cell lines was inhibited by Evo, mainly under hypoxia as expected. We also evidenced a significant synergism between Evo and three drugs widely used in pediatric oncology. Finally, Evo appeared able to potentiate the effect of ionizing radiations. Since these tumors are highly hypoxic and Evo appears effective in hypoxic glioma cells as a single drug and in combination with radio- and chemotherapy, hypoxia-activated prodrugs could represent a promising therapeutic option for children with brain tumors.

Abstract

Hypoxia is a hallmark of many solid tumors and is associated with resistance to anticancer treatments. Hypoxia-activated prodrugs (HAPs) were developed to target the hypoxic regions of these tumors. Among 2nd generation HAPs, Evofosfamide (Evo, also known as TH-302) exhibits preclinical and clinical activities against adult glioblastoma. In this study, we evaluated its potential in the field of pediatric neuro-oncology. We assessed the efficacy of Evo in vitro as a single drug, or in combination with SN38, doxorubicin, and etoposide, against three pediatric high-grade glioma (pHGG) and three diffuse intrinsic pontine glioma (DIPG) cell lines under hypoxic conditions. We also investigated radio-sensitizing effects using clonogenic assays. Evo inhibited the growth of all cell lines, mainly under hypoxia. We also highlighted a significant synergism between Evo and doxorubicin, SN38, or etoposide. Finally, Evo radio-sensitized the pHGG cell line tested, both with fractionated and single-dose irradiation schedules. Altogether, we report here the first preclinical proof of evidence about Evofosfamide efficiency against hypoxic pHGG and DIPG cells. Since such tumors are highly hypoxic, and Evo potentiates the effect of ionizing radiation and chemotherapy, it appears as a promising therapeutic strategy for children with brain tumors.