Blood flow and associated pathophysiology of uterine cervix cancers: Characterisation and relevance for localised hyperthermia

The therapeutic effect of PEI-Fe3O4/pYr-ads-8-5HRE-cfosp-IFNG albumin nanospheres combined with magnetic fluid hyperthermia on hepatoma

Background

Hepatocellular carcinoma (HCC) is one of the most prevalent and deadly malignant tumors with serious clinical and socioeconomic consequences. Although gene therapy holds great promise in the treatment of hepatoma, its clinical applications are hindered by uncontrolled gene transmission and transcription.

Methods

The pY-ads-8-5HRE-cfosp-IFNG plasmid was constructed and identified by double enzyme digestion and gene sequencing. The expression of pYr-ads-8-5HRE-cfosp-IFNG in HepG2 cells was detected by quantitative PCR. PEI-Fe3O4/pYr-ads-8-5HRE-cfosp-IFNG albumin nanospheres were prepared and characterized. In vitro heating test of magnetic albumin nanospheres in an alternating magnetic field (AMF) was carried out. The therapeutic effect of PEI-Fe3O4/pYr-ads-8-5HRE-cfosp-IFNG albumin nanospheres on hepatocellular carcinoma was investigated by cell and animal experiments. After treatment, mice blood was collected for clinical biochemical analysis and histopathological evaluation of major organs was performed to assess potential adverse effects of treatment.

Results

Double enzyme digestion and gene sequencing showed that the pY-ads-8-5HRE-cfosp-IFNG plasmid was constructed successfully. QPCR results showed that the IFNγ transcript level in the PEI-Fe3O4/pYr-ads-8-5HRE-cfosp-IFNG group was higher than that in the PEI-Fe3O4/pYr-ads-8-cfosp-IFNG group after being treated with hypoxia (P<0.05). TEM revealed that the self-prepared PEI-Fe3O4/pYr-ads-8-5HRE-cfosp-IFNG albumin nanospheres exhibit an approximately spherical or elliptical shape. The hydrodynamic size of the albumin nanospheres was 139.7 nm. The maximum temperature of 0.25 mg/mL solution is stable at about 44°C, which is suitable for tumor thermal therapy without damaging normal tissues. The relative cell inhibition rate of the radiation-gene therapy and MFH combination group was higher than that of other control groups in CCK8 experiment. (P<0.05) Flow cytometry showed that the apoptosis rate and necrosis rate of the combined treatment group were 42.32% and 35.73%, respectively, higher than those of the other groups. (P<0.05) In animal experiments, the mass and volume inhibition rates of the combined treatment group were 66.67% and 72.53%, respectively, higher than those of other control groups. (P<0.05) Clinical biochemical analysis and histopathological evaluation showed no abnormality.

Conclusions

The results indicated the successful construction of the radiation-induced plasmid and demonstrated that the hypoxia enhancer could augment the expression of INFγ in a hypoxia environment. Gene therapy combined with magnetic fluid hyperthermia (MFH) has exhibited excellent outcomes in both cell and animal studies. Our experiments demonstrated that the PEI-Fe3O4/pYr-ads-8-5HRE-cfosp-IFNG albumin nanospheres system is a comprehensive treatment method for hepatoma, which can effectively combine immune genre therapy with hyperthermia.

From Localized Mild Hyperthermia to Improved Tumor Oxygenation: Physiological Mechanisms Critically Involved in Oncologic Thermo-Radio-Immunotherapy

(1) Background: Mild hyperthermia (mHT, 39-42 °C) is a potent cancer treatment modality when delivered in conjunction with radiotherapy. mHT triggers a series of therapeutically relevant biological mechanisms, e.g., it can act as a radiosensitizer by improving tumor oxygenation, the latter generally believed to be the commensurate result of increased blood flow, and it can positively modulate protective anticancer immune responses. However, the extent and kinetics of tumor blood flow (TBF) changes and tumor oxygenation are variable during and after the application of mHT. The interpretation of these spatiotemporal heterogeneities is currently not yet fully clarified. (2) Aim and methods: We have undertaken a systematic literature review and herein provide a comprehensive insight into the potential impact of mHT on the clinical benefits of therapeutic modalities such as radio- and immuno-therapy. (3) Results: mHT-induced increases in TBF are multifactorial and differ both spatially and with time. In the short term, changes are preferentially caused by vasodilation of co-opted vessels and of upstream normal tissue vessels as well as by improved hemorheology. Sustained TBF increases are thought to result from a drastic reduction of interstitial pressure, thus restoring adequate perfusion pressures and/or HIF-1α- and VEGF-mediated activation of angiogenesis. The enhanced oxygenation is not only the result of mHT-increased TBF and, thus, oxygen availability but also of heat-induced higher O₂ diffusivities, acidosis- and heat-related enhanced O₂ unloading from red blood cells. (4) Conclusions: Enhancement of tumor oxygenation achieved by mHT cannot be fully explained by TBF changes alone. Instead, a series of additional, complexly linked physiological mechanisms are crucial for enhancing tumor oxygenation, almost doubling the initial O₂ tensions in tumors.

Correlation between Neutrophil-to-Lymphocyte Ratio and Pretreatment Magnetic Resonance Imaging and Their Predictive Significance in Cervical Carcinoma Patients Referred for Radiotherapy

OBJECTIVE

The aim of this study was to determine the correlation between neutrophil-to-lymphocyte ratio (NLR) and various tumor parameters assessed by pretreatment magnetic resonance imaging (MRI) and to evaluate their prognostic significance for cervical carcinoma treated with radiotherapy (RT).

METHODS

The study enrolled 78 patients with biopsy-proven squamous cell carcinoma (SCC) of primary cervical cancer (clinically staged IB2 to IVA) who were treated in the Department of Clinical Oncology of the University of Hong Kong-Shenzhen Hospital between August 2015 and May 2019. A retrospective analysis of patients with SCC was performed. Firstly, we investigated the correlations between NLR and MRI parameters. Then, univariate and multivariate analyses were performed to identify the prognostic factors for overall survival (OS) and progression-free survival (PFS). Kaplan-Meier curves were constructed for OS and PFS.

RESULTS

Higher NLR showed significant association with larger tumor diameter and parametrial invasion assessed by pretreatment MRI. Univariate analysis indicated that uterine body invasion, parametrial invasion, and NLR were associated with prognosis of cervical cancer. Multivariable analyses demonstrated that parametrial invasion and NLR higher than the cutoff were independently associated with shorter OS and PFS, whereas uterine body invasion showed a significantly unfavorable influence on OS but showed no significant effect on PFS. Using the three risk factors of NLR above cutoff, parametrial invasion, and uterine body invasion, patients were divided into three subgroups. The three-year OS rates of patients with zero risk factors, one risk factor, and two or three of these factors were 96%, 91%, and 42%, respectively (P < 0.001), showing a downward trend.

CONCLUSIONS

Uterine body invasion, parametrial invasion, and NLR were significant prognostic factors for patients with cervical carcinoma treated with RT. These results may supplement FIGO staging to improve prognostic assessment of patients.

In silico investigations of intratumoral heterogeneous interstitial fluid pressure

Recent preclinical studies have shown that interstitial fluid pressure (IFP) within tumors can be heterogeneous Andersen et al. (2019). In that study tumors of two xenograft models, respectively, HL-16 cervical carcinoma and Panc-1 pancreatic carcinoma, were investigated. Significant heterogeneity in IFP was reported and it was proposed that this was associated with division of tissue into compartments separated by thick connective tissue bands for the HL-16 tumors and with dense collagen-rich extracellular matrix for the Panc-1 tumors. The purpose of the current work is to explore these experimental observations by using in silico generated tumor models. We consider a mathematical multiphase model which accounts for tumor cells, fibroblasts and interstitial fluid. The model has been trained to comply with experimental in vitro results reported in Shieh et al. (2011) which has identified autologous chemotaxis, ECM remodeling, and cell-fibroblast interaction as drivers for invasive tumor cell behavior. The in silico model is informed with parameters that characterize the leaky intratumoral vascular network, the peritumoral lymphatics which collect the fluid, and the density of ECM as represented through the hydraulic conductivity of the interstitial space. Heterogeneous distribution of solid stress may result in heterogeneous compression of blood vessels and, thus, heterogeneous vascular density inside the tumor. To mimic this we expose the in silico tumor to an intratumoral vasculature whose net effect of density of blood vesssels and vessel wall conductivity is varied through a 2D Gaussian variogram constrained such that the resulting IFPs lie within the range as reported from the preclinical study. The in silico cervical carcinoma model illustrates that sparse ECM was associated with uniform intratumoral IFP in spite of heterogeneous microvascular network, whereas compartment structures resulted in more heterogeneous IFP. Similarly, the in silico pancreatic model shows that heterogeneity in the microvascular network combined with dense ECM structure prevents IFP to even out and gives rise to heterogeneous IFP. The computer model illustrates how a heterogeneous invasive front might form where groups of tumor cells detach from the primary tumor and form isolated islands, a behavior which is natural to associate with metastatic propensity. However, unlike experimental studies, the current version of the in silico model does not show an association between metastatic propensity and elevated IFP.

The Role of Multiparametric Magnetic Resonance Imaging in the Study of Primary Tumor and Pelvic Lymph Node Metastasis in Stage IB1-IIA1 Cervical Cancer

OBJECTIVE

The aim of this study was to investigate the value of multiparametric magnetic resonance imaging (MRI) in demonstrating the metastatic potential of primary tumor and differentiating metastatic lymph nodes (MLNs) from nonmetastatic lymph nodes (non-MLNs) in stage IB1-IIA1 cervical cancer.

METHODS

Fifty-seven stage IB1-IIA1 subjects were included. The apparent diffusion coefficient (ADC) values and dynamic contrast-enhanced MRI (DCE-MRI) parameters of primary tumors and lymph nodes and the conventional imaging features of the lymph nodes were measured and analyzed. Mann-Whitney test and χ test were used to analyze statistically significant parameters, logistic regression was used for multivariate analysis, and receiver operating characteristic analysis was used to compare the diagnostic performance of the MLNs.

RESULTS

Nineteen subjects had lymph node metastasis. A total of 94 lymph nodes were evaluated, including 30 MLNs and 64 non-MLNs. There were no significant difference in ADC and DCE-MRI parameters between metastatic and nonmetastatic primary tumors. The heterogeneous signal was more commonly seen in MLNs than in non-MLNs (P = 0.001). The values of ADCmean, ADCmin, and ADCmax of MLNs were lower than those of non-MLNs (P < 0.001). The values of short-axis diameter, K, Kep, and Ve of MLNs were higher than those of non-MLNs (P < 0.05). Compared with individual MRI parameters, the combined evaluation of short-axis diameter, ADCmean, and K showed the highest area under the curve of 0.930.

CONCLUSIONS

Diffusion-weighted imaging and DCE-MRI could not demonstrate the metastatic potential of primary tumor in stage IB1-IIA1 cervical cancer. Compared with individual MRI parameters, the combination of multiparametric MRI could improve the diagnostic performance of lymph node metastasis.

The effect of modulated electro-hyperthermia on temperature and blood flow in human cervical carcinoma

INTRODUCTION

Mild hyperthermia has been known to enhance the response of tumours to radiotherapy or chemotherapy by increasing tumour blood flow, thereby increasing tumour oxygenation or drug delivery. The purpose of this study was to assess the changes in temperature and blood flow in human cervical cancer in response to regional heating with modulated electro-hyperthermia (mEHT).

METHODS

The pelvic area of 20 patients with cervical carcinoma was heated with mEHT. The peri-tumour temperature was measured using an internal organ temperature probe. The tumour blood flow was measured using 3D colour Doppler ultrasound by determining the peak systolic velocity/end-diastolic velocity ratio (S/D ratio) and the resistance index (RI) within blood vessels.

RESULTS

The mean peri-tumour temperature was 36.7 ± 0.2 °C before heating and increased to 38.5 ± 0.8 °C at the end of heating for 60 min. The marked declines in RI and S/D values strongly demonstrated that heating significantly increased tumour blood perfusion.

CONCLUSIONS

Regional heating of the pelvic area with mEHT significantly increased the peri-tumour temperature and improved the blood flow in cervical cancer. This is the first demonstration that the blood flow in cervical cancer is increased by regional hyperthermia. Such increases in temperature and blood flow may account for the clinical observations that hyperthermia improves the response of cervical cancer to radiotherapy or chemotherapy.

Heat-induced BRCA2 degradation in human tumours provides rationale for hyperthermia-PARP-inhibitor combination therapies

PURPOSE

Hyperthermia (40-44 °C) effectively sensitises tumours to radiotherapy by locally altering tumour biology. One of the effects of heat at the cellular level is inhibition of DNA repair by homologous recombination via degradation of the BRCA2-protein. This suggests that hyperthermia can expand the group of patients that benefit from PARP-inhibitors, a drug exploiting homologous recombination deficiency. Here, we explore whether the molecular mechanisms that cause heat-mediated degradation of BRCA2 are conserved in cell lines from various origins and, most importantly, whether, BRCA2 protein levels can be attenuated by heat in freshly biopted human tumours.

EXPERIMENTAL DESIGN

Cells from four established cell lines and from freshly biopsied material of cervical (15), head- and neck (9) or bladder tumours (27) were heated to 42 °C for 60 min ex vivo. In vivo hyperthermia was studied by taking two biopsies of the same breast or cervical tumour: one before and one after treatment. BRCA2 protein levels were measured by immunoblotting.

RESULTS

We found decreased BRCA2-levels after hyperthermia in all established cell lines and in 91% of all tumours treated ex vivo. For tumours treated with hyperthermia in vivo, technical issues and intra-tumour heterogeneity prevented obtaining interpretable results.

CONCLUSIONS

This study demonstrates that heat-mediated degradation of BRCA2 occurs in tumour material directly derived from patients. Although BRCA2-degradation may not be a practical biomarker for heat deposition in situ, it does suggest that application of hyperthermia could be an effective method to expand the patient group that could benefit from PARP-inhibitors.

The study on the preparation and characterization of gene-loaded immunomagnetic albumin nanospheres and their anti-cell proliferative effect combined with magnetic fluid hyperthermia on GLC-82 cells

As one of the most common malignant tumors, the clinical and socio-economic consequences of lung cancer are significant. Currently, surgery is the main treatment strategy for this disease, but the survival rates of lung cancer patients are not ideal due to the high recurrence rate of the disease. Therefore, many researchers are exploring new specific therapeutic methods that are highly curative and minimally cytotoxic to healthy tissues. To this end, albumin nanospheres simultaneously were loaded with super-paramagnetic iron oxide nanoparticles (as gene vector and anticancer gene), and plasmid pDONR223-IFNG, and modified with anti-EGFR monoclonal antibody cetuximab as therapy. Targeting agents, namely gene-loaded immunomagnetic albumin nanospheres (cetuximab [C225]-IFNG-IMANS), were prepared for targeted lung carcinoma cells (GLC-82 cell lines). Transmission electron microscopy images showed that the C225-IFNG-IMANS were successfully prepared, and the ability of the nanospheres to target GLC-82 cells in vitro was confirmed by Prussian blue staining, immunofluorescence experiments, and magnetic resonance imaging. Transfection photographs and agarose gel electrophoresis proved that pDONR223-IFNG could be encased in the albumin nanospheres. A Cell Counting Kit-8 assay showed that the combination therapy group had significantly more therapeutic effects on GLC-82 cells than other therapy groups. A flow cytometry assay showed that the apoptotic index of the combined treatment group was 67.68%, whereas the indices of the C225 group, gene therapy group, and magnetic fluid hyperthermia group were 12.2%, 16.34%, and 20.04% respectively. Therefore, the combination of thermal treatment, molecular targeted treatment, and gene treatment synergistically targets GLC-82 cells, and the use of C225-IFNG-IMANS as a gene or drug carrier offers a novel and promising approach for the treatment of lung cancer.

Sonochemotherapy: from bench to bedside

The combination of microbubbles and ultrasound has emerged as a promising method for local drug delivery. Microbubbles can be locally activated by a targeted ultrasound beam, which can result in several bio-effects. For drug delivery, microbubble-assisted ultrasound is used to increase vascular- and plasma membrane permeability for facilitating drug extravasation and the cellular uptake of drugs in the treated region, respectively. In the case of drug-loaded microbubbles, these two mechanisms can be combined with local release of the drug following destruction of the microbubble. The use of microbubble-assisted ultrasound to deliver chemotherapeutic agents is also referred to as sonochemotherapy. In this review, the basic principles of sonochemotherapy are discussed, including aspects such as the type of (drug-loaded) microbubbles used, the routes of administration used in vivo, ultrasound devices and parameters, treatment schedules and safety issues. Finally, the clinical translation of sonochemotherapy is discussed, including the first clinical study using sonochemotherapy.

Therapeutic potential of using the vascular disrupting agent OXi4503 to enhance mild temperature thermoradiation

PURPOSE

The response of tissues to radiation with mild temperature hyperthermia is dependent on the interval between the two modalities. This study investigated the effect that the vascular disrupting agent OXi4503 had on this time-interval interaction.

METHODS

The normal right rear foot of female CDF1 mice or foot-implanted C3H mammary carcinomas were locally irradiated (230 kV X-rays) and heated (41.5 °C for 60 min) by foot immersion in a water bath. OXi4503 (50 mg/kg) was injected intraperitoneally 1.5 h before irradiating. Irradiation was performed either in the middle of the heating period (simultaneous treatment) or at 1 or 4 h prior to starting the heating (sequential treatments). Response was the percentage of mice showing local tumour control at 90 days or skin moist desquamation between days 11-23. From the radiation dose response curves the dose producing tumour control (TCD(50)) or moist desquamation (MDD50) in 50% of mice was calculated.

RESULTS

The TCD(50) and MDD50 values for radiation alone were 54 Gy and 29 Gy, respectively. Simultaneously heating the tissues enhanced radiation response, the respective TCD(50) and MDD50 values being significantly (chi-square test, p < 0.05) reduced to 33 Gy and 14 Gy. A smaller enhancement was obtained with a sequential treatment in both tissues. OXi4503 enhanced the radiation response of tumour and skin. Combined with radiation and heat, the only effect was in tumours where OXi4503 prevented the decrease in sensitisation seen with the sequential treatment.

CONCLUSION

Combining OXi4503 with a sequential radiation and heat treatment resulted in a 1.4-fold therapeutic gain.

Magnetic nanoparticles for targeted therapeutic gene delivery and magnetic-inducing heating on hepatoma

Gene therapy holds great promise for treating cancers, but their clinical applications are being hampered due to uncontrolled gene delivery and expression. To develop a targeted, safe and efficient tumor therapy system, we constructed a tissue-specific suicide gene delivery system by using magnetic nanoparticles (MNPs) as carriers for the combination of gene therapy and hyperthermia on hepatoma. The suicide gene was hepatoma-targeted and hypoxia-enhanced, and the MNPs possessed the ability to elevate temperature to the effective range for tumor hyperthermia as imposed on an alternating magnetic field (AMF). The tumoricidal effects of targeted gene therapy associated with hyperthermia were evaluated in vitro and in vivo. The experiment demonstrated that hyperthermia combined with a targeted gene therapy system proffer an effective tool for tumor therapy with high selectivity and the synergistic effect of hepatoma suppression.

Heat-activated thermosensitive liposomal cisplatin (HTLC) results in effective growth delay of cervical carcinoma in mice

Cisplatin (CDDP) has been identified as the primary chemotherapeutic agent for the treatment of cervical cancer, but dose limiting toxicity is a key issue associated with its clinical application. A suite of liposome formulations of CDDP has been developed in efforts to reduce systemic toxicity, but their therapeutic advantage over the free drug has been modest due to insufficient drug release at the tumor site. This report describes the development of a novel heat-activated thermosensitive liposome formulation containing CDDP (HTLC) designed to release approximately 90% of the loaded drug in less than 5min under mild heating conditions (42°C). Physico-chemical characteristics of HTLC were assessed in terms of gel to liquid crystalline phase transition temperature (Tm), drug loading efficiency, particle size, and stability. The pharmacokinetic profile and biodistribution of HTLC in non-tumor-bearing mice were evaluated over a 24h period. A sophisticated spatio-temporal elucidation of HTLC release in tumor-bearing mice was achieved by way of real-time monitoring using a magnetic resonance (MR) imaging protocol, wherein a custom-built laser-based conformal heat source was applied at the tumor volume to trigger the release of HTLC co-encapsulated with the MR contrast agent gadoteridol (Gd-HP-DO3A). MR thermometry (MRT) demonstrated that a relatively uniform temperature distribution was achieved in the tumor volume using the external laser-based heating setup. In mice bearing subcutaneously-implanted ME-180 cervical tumors, the combination of HTLC and heat resulted in a 2-fold increase in tumor drug levels at 1h post-administration compared to HTLC without heating. Furthermore, the overall tumor accumulation levels for the HTLC groups (with and without heat) at 1h post-injection were significantly higher than the corresponding free CDDP group. This translated into a significant improvement in therapeutic efficacy evaluated as tumor growth delay (p<0.05) for the heated HTLC treatment group compared to the unheated HTLC, heated or unheated free CDDP, and saline groups. Overall, findings from this study demonstrate that a heat-activated, triggered release formulation of CDDP results in a significant enhancement in the therapeutic index of this drug.

The Microenvironment of Cervical Carcinoma Xenografts: Associations with Lymph Node Metastasis and Its Assessment by DCE-MRI

Poor disease-free and overall survival rates in locally advanced cervical cancer are associated with a tumor micro-environment characterized by extensive hypoxia, interstitial hypertension, and high lactate concentrations. The potential of gadolinium diethylenetriamine pentaacetic acid-based dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the microenvironment and microenvironment-associated aggressiveness of cervical carcinomas was investigated in this preclinical study. CK-160 and TS-415 cervical carcinoma xenografts were used as tumor models. DCE-MRI was carried out at 1.5 T, and parametric images of K (trans) and v e were produced by pharmacokinetic analysis of the DCE-MRI series. Pimonidazole was used as a marker of hypoxia. A Millar catheter was used to measure tumor interstitial fluid pressure (IFP). The concentrations of glucose, adenosine triphosphate (ATP), and lactate were measured by induced metabolic bioluminescence imaging. High incidence of lymph node metastases was associated with high hypoxic fraction and high lactate concentration in CK-160 tumors and with high IFP and high lactate concentration in TS-415 tumors. Low K (trans) was associated with high hypoxic fraction, low glucose concentration, and high lactate concentration in tumors of both lines and with high incidence of metastases in CK-160 tumors. Associations between v e and microenvironmental parameters or metastatic propensity were not detected in any of the tumor lines. Taken together, this preclinical study suggests that K (trans) is a potentially useful biomarker for poor outcome of treatment in advanced cervical carcinoma. The possibility that K (trans) may be used to identify patients with cervical cancer who are likely to benefit from particularly aggressive treatment merits thorough clinical investigations.