Anti-angiogenic action of hyperthermia by suppressing gene expression and production of tumour-derived vascular endothelial growth factor in vivo and in vitro

Photothermal therapy: a novel potential treatment for prostate cancer

Prostate cancer (PCa) is a leading cause of cancer-related death in men, and most PCa patients treated with androgen deprivation therapy will progress to metastatic castration-resistant prostate cancer (mCRPC) due to the lack of efficient treatment. Recently, lots of research indicated that photothermal therapy (PTT) was a promising alternative that provided an accurate and efficient prostate cancer therapy. A photothermic agent (PTA) is a basic component of PPT and is divided into organic and inorganic PTAs. Besides, the combination of PTT and other therapies, such as photodynamic therapy (PDT), immunotherapy (IT), chemotherapy (CT), etc., provides an more efficient strategy for PCa therapy. Here, we introduce basic information about PTT and summarize the PTT treatment strategies for prostate cancer. Based on recent works, we think the combination of PPT and other therapies provides a novel possibility for PCa, especially CRPC clinical treatment.

Hyperthermia Influences the Secretion Signature of Tumor Cells and Affects Endothelial Cell Sprouting

Tumors are a highly heterogeneous mass of tissue showing distinct therapy responses. In particular, the therapeutic outcome of tumor hyperthermia treatments has been inconsistent, presumably due to tumor versus endothelial cell cross-talks related to the treatment temperature and the tumor tissue environment. Here, we investigated the impact of the average or strong hyperthermic treatment (43 °C or 47 °C for 1 h) of the human pancreatic adenocarcinoma cell line (PANC-1 and BxPC-3) on endothelial cells (HUVECs) under post-treatment normoxic or hypoxic conditions. Immediately after the hyperthermia treatment, the distinct repression of secreted pro-angiogenic factors (e.g., VEGF, PDGF-AA, PDGF-BB, M-CSF), intracellular HIF-1α and the enhanced phosphorylation of ERK1/2 in tumor cells were detectable (particularly for strong hyperthermia, 2D cell monolayers). Notably, there was a significant increase in endothelial sprouting when 3D self-organized pancreatic cancer cells were treated with strong hyperthermia and the post-treatment conditions were hypoxic. Interestingly, for the used treatment temperatures, the intracellular HIF-1α accumulation in tumor cells seems to play a role in MAPK/ERK activation and mediator secretion (e.g., VEGF, PDGF-AA, Angiopoietin-2), as shown by inhibition experiments. Taken together, the hyperthermia of pancreatic adenocarcinoma cells in vitro impacts endothelial cells under defined environmental conditions (cell-to-cell contact, oxygen status, treatment temperature), whereby HIF-1α and VEGF secretion play a role in a complex context. Our observations could be exploited for the hyperthermic treatment of pancreatic cancer in the future.

The Role of Hyperthermia in Potentiation of Anti-Angiogenic Effect of Cisplatin and Resveratrol in Mice Bearing Solid Form of Ehrlich Ascites Tumour

The aim of this study was to investigate the therapeutic potential of resveratrol in combination with cisplatin on the inhibition of tumour angiogenesis, growth, and macrophage polarization in mice bearing the solid form of an Ehrlich ascites tumour (EAT) that were exposed to whole-body hyperthermia treatment. In addition, we investigated whether a multimodal approach with hyperthermia and resveratrol could abolish cisplatin resistance in tumour cells through the modulation of histone deacetylase (HDAC) activity and levels of heat shock proteins (HSP70/HSP90) and contribute to the direct toxicity of cisplatin on tumour cells. The tumour was induced by injecting 1 × 10⁶ EAT cells subcutaneously (sc) into the thighs of Balb/c mice. The mice were treated with resveratrol per os for five consecutive days beginning on day 2 after tumour injection and/or by injecting cisplatin intraperitoneally (ip) at a dose of 2.5 mg/kg on days 10 and 12 and at a dose of 5 mg/kg on day 15. Immediately thereafter, the mice were exposed to systemic hyperthermia for 15 min at a temperature of 41 °C. The obtained results showed that the administration of resveratrol did not significantly contribute to the antitumour effect of cisplatin and hyperthermia, but it partially contributed to the immunomodulatory effect and to the reduction of cisplatin toxicity and to a slight increase in animal survival. This treatment schedule did not affect microvessel density, but it inhibited tumour growth and modulated macrophage polarization to the M1 phenotype. Furthermore, it abolished the resistance of tumour cells to cisplatin by modulating HDAC activity and the concentration of HSP70 and HSP90 chaperones, contributing to the increased lifespan of mice. However, the precise mechanism of the interaction between resveratrol, cisplatin, and hyperthermia needs to be investigated further.

Efficacy of the low dose apatinib plus deep hyperthermia as third-line or later treatment in HER-2 negative advanced gastric cancer

Aim: To observe the efficacy of the low dose apatinib plus deep hyperthermia as third-line or later treatment for patients with human epidermal growth factor receptor 2 (HER-2) negative advanced gastric cancer. Methods: 80 eligible patients with HER-2 negative advanced gastric cancer admitted to Jingjiang People's Hospital Affiliated with Yangzhou University-from March 2021 to March 2022 were selected, and they were divided into the control group (n = 40, apatinib) and experimental group (n = 40, apatinib plus deep hyperthermia) on the basis of random number table method. The levels of serum carcinoembryonic antigen (CEA), carbohydrate antigen 199 (CA199), and vascular endothelial growth factor (VEGF) were monitored, and the efficacy of the two groups was analyzed by referring to Karnofsky performance status (KPS), overall survival (OS) and disease control rate (DCR) before and after treatment. Results: The levels of CEA, CA199, and VEGF in both groups were lower after treatment than before (p < 0.05), and lower (CEA: 8.85 ± 1.36 vs. 12.87 ± 1.23, CA199: 34.19 ± 4.68 vs. 50.11 ± 5.73, VEGF: 124.8 ± 18.03 vs. 205.9 ± 19.91) in the experimental group than in the control group (p < 0.05). The DCR and KPS of the patients in the experimental group were significantly higher (DCR: 62.50% vs. 40.00%; KPS: 83.25 ± 1.15 vs. 76.25 ± 1.17) than in the control group (p < 0.05). In survival analysis, patients with control group had shorter OS than the experimental group. (median 5.65 vs. 6.50 months; hazard ratio [HR], 1.63 [95% confidence interval (CI) 1.02-2.60], p = 0.0396). Conclusion: The application of low-dose apatinib plus deep hyperthermia for patients with HER-2 negative gastric cancer who failed second-line treatment should be a promising option.

Moxibustion for the Treatment of Cancer and its Complications: Efficacies and Mechanisms

Cancer treatment remains a significant challenge for the medical community, and improved therapies are necessary to treat cancer and its associated complications. Current anticancer therapies often have significant side effects, underscoring the need for new treatment options. Moxibustion is a representative external therapy used in traditional Chinese medicine. This review examines clinical studies demonstrating moxibustion's ability to improve the efficacy of radiotherapy and chemotherapy and control tumor progression. Moxibustion can prevent and treat various complications of cancer, including cancer-related or therapy-induced gastrointestinal symptoms, myelosuppression, fatigue, pain, and postoperative lymphedema. has also been shown to enhance the quality of life for cancer patients. However, very few studies have investigated the underlying mechanisms for these effects, a topic that requires systematic elucidation. Evidence has shown that moxibustion alone or combined with chemotherapy can improve survival and inhibit tumor growth in cancer-bearing animal models. The anticancer effect of moxibustion is associated with alleviating the tumor immunosuppressive and vascular microenvironments. Additionally, the therapeutic effects of moxibustion may originate from the heat and radiation produced during the combustion process on acupoints or lesions. This evidence provides a scientific basis for the clinical application of moxibustion in anticancer treatment and reducing the side effects of cancer therapies and helps promote the precise application of moxibustion in cancer treatment.

Management of the Cavity After Removal of Giant Cell Tumor of the Bone

Purpose: To find out the most appropriate management scheme through the analysis and comparison of different inactivation methods and filling materials. Method: A systematic literature search was performed using the terms, anhydrous ethanol, phenol, hypertonic saline, cryotherapy, thermal therapy, bone reconstruction, GCTB, and etc., Selected articles were studied and summarized. The mechanism, clinical effects, and influence on bone repair of various methods are presented. Recent developments and perspectives are also demonstrated. Recent Findings: Compared to curettage alone, management of the residual cavity can effectively reduce the recurrence of giant cell tumours of bone. It is a complex and multidisciplinary process that includes three steps: local control, cavity filling, and osteogenic induction. In terms of local control, High-speed burring can enlarge the area of curettage but may cause the spread and planting of tumour tissues. Among the inactivation methods, Anhydrous ethanol, and hyperthermia therapy are relatively safe and efficient. The combination of the two may achieve a better inactivation effect. When inactivating the cavity, we need to adjust the approach according to the invasion of the tumour. Filling materials and bone repair should also be considered in management.

Application of phototherapeutic-based nanoparticles in colorectal cancer

Colorectal cancer (CRC) is the third most commonly diagnosed malignancy and the second leading cause of cancer death, which accounts for approximately 10% of all new cancer cases worldwide. Surgery is the main method for treatment of early-stage CRC. However, it is not effective for most metastatic tumors, and new treatment and diagnosis strategies need to be developed. Photosensitizers (PSs) play an important role in the treatment of CRC. Phototherapy also has a broad prospect in the treatment of CRC because of its low invasiveness and low toxicity. However, most PSs are associated with limitations including poor solubility, poor selectivity and high toxicity. The application of nanomaterials in PSs has added many advantages, including increased solubility, bioavailability, targeting, stability and low toxicity. In this review, based on phototherapy, we discuss the characteristics and development progress of PSs, the targeting of PSs at organ, cell and molecular levels, and the current methods of optimizing PSs, especially the application of nanoparticles as carriers in CRC. We introduce the photosensitizer (PS) targeting process in photodynamic therapy (PDT), the damage mechanism of PDT, and the application of classic PS in CRC. The action process and damage mechanism of photothermal therapy (PTT) and the types of ablation agents. In addition, we present the imaging examination and the application of PDT / PTT in tumor, including (fluorescence imaging, photoacoustic imaging, nuclear magnetic resonance imaging, nuclear imaging) to provide the basis for the early diagnosis of CRC. Notably, single phototherapy has several limitations in vivo, especially for deep tumors. Here, we discuss the advantages of the combination therapy of PDT and PTT compared with the single therapy. At the same time, this review summarizes the clinical application of PS in CRC. Although a variety of nanomaterials are in the research and development stage, few of them are actually on the market, they will show great advantages in the treatment of CRC in the near future.

Impact of systemic inflammatory markers on the response to Hyperthermic IntraVEsical Chemotherapy (HIVEC) in patients with non-muscle-invasive bladder cancer after bacillus Calmette-Guérin failure

Objectives: To evaluate the impact of pre- and post-treatment systemic inflammatory markers on the response to Hyperthermic IntraVEsical Chemotherapy (HIVEC) treatment in a cohort of patients with high-grade non-muscle-invasive bladder cancer with bacillus Calmette–Guérin (BCG) failure or intolerance who were unsuitable or unwilling to undergo early radical cystectomy. As a secondary endpoint, we assessed the influence of some demographic, clinical and pathological factors on the response to chemo-hyperthermia.

Patients and methods: Between March 2017 and December 2019, 72 consecutive patients were retrospectively analysed. Patients with diseases or conditions that could interfere with systemic inflammatory status or full blood count were excluded. The HIVEC protocol consisted of six weekly intravesical treatments with 40 mg Mitomycin-C diluted in 50 mL distilled water. The drug was heated to a temperature of 43°C. Association of categorical variables with response to HIVEC was evaluated using Yates’ chi-squared test and differences in continuous variable were analysed using the Mann–Whitney test. Logistic regression analysis was performed to define independent predictors of response to HIVEC.

Results: Patients who failed HIVEC were more likely to have multiple tumours (P = 0.039) at transurethral resection of bladder and a recurrence rate of >1/year (P = 0.046). Lower post-HIVEC inflammatory indices [C-reactive protein (P = 0.021), erythrocyte sedimentation rate (P = 0.027)] and lower pre- (P = 0.014) and post-treatment (P = 0.004) neutrophil-to-lymphocyte ratio (NLR) values were significantly associated with the response to the HIVEC regimen (no bladder cancer recurrence or progression). In the multivariate analysis, patients with a recurrence rate of >1/year were eight-times more likely to experience failure of HIVEC (P = 0.007). Higher pre- (P = 0.023) and post-treatment NLR values (P = 0.046) were associated with a worse response to the HIVEC regimen.

Conclusions: The recurrence rate and systemic inflammatory response markers could be useful tools to predict the likelihood of obtaining a response with the HIVEC regimen. These markers might help to guide patients about the behaviour of the tumour after BCG failure, predicting failure or success of a conservative treatment.

Abbreviations: CHT: chemo-hyperthermia; CIS: carcinoma in situ; CRP: C-reactive protein; EAU: European Association of Urology; ESR: erythrocyte sedimentation rate; HG: high grade; HIVEC: Hyperthermic IntraVEsical Chemotherapy; ICD: immunogenic cell death; IL: interleukin; MMC: Mitomycin-C; NK: natural killer; NLR: neutrophil-to-lymphocyte ratio; NMIBC: non-muscle-invasive bladder cancer; PLR: platelet-to-lymphocyte ratio; RC: radical cystectomy; SIR: systemic inflammatory response; TURB: transurethral resection of bladder

Bifunctional scaffolds of hydroxyapatite/poly(dopamine)/carboxymethyl chitosan with osteogenesis and anti-osteosarcoma effect

Bifunctional scaffolds prepared by hydroxyapatite/poly(dopamine)/carboxymethyl chitosan with good osteogenesis and anti-osteosarcoma effect is promising for bone tumor therapy.

Hyperthermia can alter tumor physiology and improve chemo- and radio-therapy efficacy

Hyperthermia has demonstrated clinical success in improving the efficacy of both chemo- and radio-therapy in solid tumors. Pre-clinical and clinical research studies have demonstrated that targeted hyperthermia can increase tumor blood flow and increase the perfused fraction of the tumor in a temperature and time dependent manner. Changes in tumor blood circulation can produce significant physiological changes including enhanced vascular permeability, increased oxygenation, decreased interstitial fluid pressure, and reestablishment of normal physiological pH conditions. These alterations in tumor physiology can positively impact both small molecule and nanomedicine chemotherapy accumulation and distribution within the tumor, as well as the fraction of the tumor susceptible to radiation therapy. Hyperthermia can trigger drug release from thermosensitive formulations and further improve the accumulation, distribution, and efficacy of chemotherapy.

Ultrasound microbubble potentiated enhancement of hyperthermia-effect in tumours

It is now well established that for tumour growth and survival, tumour vasculature is an important element. Studies have demonstrated that ultrasound-stimulated microbubble (USMB) treatment causes extensive endothelial cell death leading to tumour vascular disruption. The subsequent rapid vascular collapse translates to overall increases in tumour response to various therapies. In this study, we explored USMB involvement in the enhancement of hyperthermia (HT) treatment effects. Human prostate tumour (PC3) xenografts were grown in mice and were treated with USMB, HT, or with a combination of the two treatments. Treatment parameters consisted of ultrasound pressures of 0 to 740 kPa, the use of perfluorocarbon-filled microbubbles administered intravenously, and an HT temperature of 43°C delivered for various times (0–50 minutes). Single and multiple repeated treatments were evaluated. Tumour response was monitored 24 hours after treatments and tumour growth was monitored for up to over 30 days for a single treatment and 4 weeks for multiple treatments. Tumours exposed to USMB combined with HT exhibited enhanced cell death (p<0.05) and decreased vasculature (p<0.05) compared to untreated tumours or those treated with either USMB alone or HT alone within 24 hours. Deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining and cluster of differentiation 31 (CD31) staining were used to assess cell death and vascular content, respectively. Further, tumours receiving a single combined USMB and HT treatment exhibited decreased tumour volumes (p<0.05) compared to those receiving either treatment alone when monitored over the duration of 30 days. Additionally, tumour response monitored weekly up to 4 weeks demonstrated a reduced vascular index and tumour volume, increased fibrosis and lesser number of proliferating cells with combined treatment of USMB and HT. Thus in this study, we characterize a novel therapeutic approach that combines USMB with HT to enhance treatment responses in a prostate cancer xenograft model in vivo.

Effect of Polymer Phase Transition Behavior on Temperature-Responsive Polymer-Modified Liposomes for siRNA Transfection

Small interfering RNAs (siRNAs) have been attracting significant attention owing to their gene silencing properties, which can be utilized to treat intractable diseases. In this study, two temperature-responsive liposomal siRNA carriers were prepared by modifying liposomes with different polymers-poly(N-isopropylacrylamide-co-N,N-dimethylaminopropyl acrylamide) (P(NIPAAm-co-DMAPAAm)) and poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide) P(NIPAAm-co-DMAAm). The phase transition of P(NIPAAm-co-DMAPAAm) was sharper than that of P(NIPAAm-co-DMAAm), which is attributed to the lower co-monomer content. The temperature dependent fixed aqueous layer thickness (FALT) of the prepared liposomes indicated that modifying liposomes with P(NIPAAm-co-DMAPAAm) led to a significant change in the thickness of the fixed aqueous monolayer between 37 °C and 42 °C; while P(NIPAAm-co-DMAAm) modification led to FALT changes over a broader temperature range. The temperature-responsive liposomes exhibited cellular uptake at 42 °C, but were not taken up by cells at 37 °C. This is likely because the thermoresponsive hydrophilic/hydrophobic changes at the liposome surface induced temperature-responsive cellular uptake. Additionally, siRNA transfection of cells for the prevention of luciferase and vascular endothelial growth factor (VEGF) expression was modulated by external temperature changes. P(NIPAAm-co-DMAPAAm) modified liposomes in particular exhibited effective siRNA transfection properties with low cytotoxicity compared with P(NIPAAm-co-DMAAm) modified analogues. These results indicated that the prepared temperature-responsive liposomes could be used as effective siRNA carriers whose transfection properties can be modulated by temperature.

Synergistic action of microwave-induced mild hyperthermia and paclitaxel in inducing apoptosis in the human breast cancer cell line MCF-7

Microwave mild hyperthermia and paclitaxel have been reported to be involved in variety of solid tumors. However, rare related researches have been accomplished via directly killing tumor cells using thermochemotherapy. In order to clarify the potential synergy between microwave-induced hyperthermia at temperatures <41°C and paclitaxel chemotherapy for inhibiting the growth of the human breast cancer cell line MCF-7, an MTT assay was used. The MCF-7 cells cultured in vitro were treated with paclitaxel alone, treated with microwave-induced hyperthermia for 2 h alone (at 40, 40.5 or 41°C), or treated with a combination of paclitaxel and 2 h of hyperthermia (at 40, 40.5 or 41°C). Flow cytometry was used to determine the cell apoptosis rate and it was demonstrated that paclitaxel decreased cell viability in a dose-dependent manner. Alone, hyperthermia for 2 h at 41°C induced apoptosis in MCF-7 cells, to a greater extent compared with hyperthermia for 2 h at 40.0 or 40.5°C (P<0.05). Together, paclitaxel and 2 h of hyperthermia at 40.5°C induced significantly increased apoptosis compared with either treatment alone (P<0.05). Increasing the temperature to 41°C in combination with paclitaxel increased the apoptotic ratio from 12.21±1.02% to 16.36±2.39%. The apoptotic ratio correlated positively with hyperthermia temperature and duration following hyperthermia, as did the synergistic effect obtained by combining hyperthermia and paclitaxel. Notably, the combination of 5 µg/ml paclitaxel and 2 h of hyperthermia at 40°C enhanced MCF-7 cell proliferation. Mild hyperthermia may exert anti-tumor effects by inducing apoptosis, and combining hyperthermia with paclitaxel synergistically induces apoptosis. Paclitaxel dose and hyperthermia temperature require careful optimization, as low-dose paclitaxel combined with hyperthermia at an insufficient temperature may enhance breast cancer proliferation.

Impact of VEGFA polymorphisms on glioma risk in Chinese

Several single nucleotide polymorphisms (SNPs) in the vascular endothelial growth factor A (VEGFA) gene have been previously reported to be associated with glioma susceptibility, but individual studies have demonstrated inconclusive results. In the current study, a meta-analysis was performed to derive a more precise estimation of the involvement of VEGFA polymorphisms in glioma development. A comprehensive literature search conducted in PubMed, Embase, the Cochrane Library, and OVID databases through February 25, 2017 yielded 4 eligible studies consisting of 2,275 cases and 2,475 controls. Pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated under allele contrast, dominant, recessive, homozygous, and heterozygous models. In general, minor alleles of polymorphisms rs3025039, rs2010963, and rs3025030 were associated with increased glioma risk. In contrast, a significant correlation was found between the minor allele of polymorphism rs3024994 and decreased susceptibility to glioma. Moreover, statistically significant associations with glioma risk were observed for polymorphisms rs1413711 and rs3025035 in the meta-analysis although positive associations were not observed in any of the included studies individually. No significant correlations with glioma susceptibility were identified for polymorphisms rs3025010 or rs833069 except in the recessive model. Finally, stratified analysis on the basis of genotyping method and Hardy-Weinberg equilibrium (HWE) in controls revealed no significant difference between subgroups. Our results indicated that several VEGFA polymorphisms might be risk factors for glioma in Chinese. More studies with larger sample sizes using different ethnicities are needed to provide additional evidence.

Nanoparticles for inhibition of in vitro tumour angiogenesis: synergistic actions of ligand function and laser irradiation

Careful design of nanoparticles plays a crucial role in their biomedical applications. It not only defines the stability of nanoparticles in a biological medium but also programs their biological functionality and specific interactions with cells. Here, an inorganic nanoparticulate system engineered to have a dual role as anti-angiogenic and hyperthermic agent is presented. The inorganic rod-shaped core is designed to strongly absorb near-infrared laser irradiation through the surface plasmon resonance and convert it into localized heat, while a peptide coating acts as an anti-angiogenic drug, altogether inhibiting vascular growth. The synergistic dual action provides an improved inhibition of the in vitro tumour angiogenesis, offering new possibilities for the development of nano-engineered anti-angiogenic drugs for therapies.

Angiogenesis-related prognosis in patients with oral squamous cell carcinoma-role of the VEGF +936 C/T polymorphism

BACKGROUND

The aim of the study was the immunohistological assessment of VEGF-single nucleotide polymorphism (SNP)-related angiogenic activity in oral squamous cell carcinoma (OSCC) in correlation with prognosis.

METHODS

Fifty OSCC samples were immunostained with CD31-antibodies. Mean microvessel density (MVD) and staining intensity were determined and associated with clinicopathological/prognostic features as well as with the VEGF +936C/T SNP.

RESULTS

A significant higher MVD could be seen for T3 and T4 compared with T1 and T2, N > 0 vs. N0 as well as G3-G4 vs. G1-G2 OSCCs (all: P < 0.05). A higher MVD was also associated with increased and earlier rates of local relapses, more metastases, and a significant decreased overall as well as disease-free survival (all: P < 0.05). When comparing T1 and T2 samples with +936-T-allele with T 1&2 samples without this allele, staining intensity was significantly increased (P = 0.002).

CONCLUSIONS

Angiogenesis influences local as well as distant growth of OSCCs with a significant correlation between prognostic parameters. The correlation between VEGF +936-T-allele and increased CD31 immunostain needs further confirmation.

Hyperthermia inhibited the migration of tongue squamous cell carcinoma through TWIST2

BACKGROUND

Hyperthermia has been shown promising in the treatment of head and neck squamous cell carcinoma (HNSCC); however, the mechanism underlying hyperthermia reducing tumor metastasis is poorly elucidated. TWIST2, an important transcription factor of epithelial-mesenchymal transition (EMT), plays a critical role in the tumor progression and metastasis. The role of TWIST2 in tongue squamous cell carcinoma (TSCC) and its association with hyperthermia still have not been reported.

METHOD

The correlations between TWIST2 expression and the clinical-pathologic characteristics of 89 patients with TSCC were evaluated by immunohistochemical staining. TSCC cell lines transfected with siRNA against TWIST2 were heated for 40 min at 42.5°C, and the migration capability of cells was examined by migration assay. Xenograft tumors in nude mice were treated by hyperthermia, and TWIST2 expression was measured.

RESULTS

Our data showed that TWIST2 expression was associated with the metastasis of human TSCC. In Tca8113 and Cal-27 cells, TWIST2-siRNA treatment can reduce cell migration ability and has no effect on the cell proliferation and apoptosis. Hyperthermia can decrease the level of TWIST2 in TSCC and inhibit the migration of cells.

CONCLUSIONS

This demonstrated that hyperthermia might decrease the migration of Tca8113 and Cal-27 cells by reducing TWIST2 expression. Altogether, these findings suggest an as yet undescribed link between TWIST2 and hyperthermia in TSCC.

The inhibitory effect of heat treatment against epithelial-mesenchymal transition (EMT) in human pancreatic adenocarcinoma cell lines

Epithelial-mesenchymal transition (EMT) plays a crucial role in cancer metastasis. In this study, we evaluated the effect of heat treatment on tumor growth factor-β1 (TGF-β1)-induced EMT in pancreatic cancer cells and tried to ascertain the mechanism related to any observed effects. Human pancreatic cancer cell lines (BxPC-3, PANC-1 and MIAPaCa-2) were stimulated by TGF-β1, and evaluated for morphological changes using immunofluorescence and EMT-related factors (i.e., E-cadherin, Vimentin, Snail or ZEB-1) using RT-PCR. To examine the effect of heat on EMT, the cancer cells were heat-treated at 43°C for 1 h then stimulated with TGF-β1. We then evaluated whether or not heat treatment changed the expression of EMT-related factors and cell migration and also whether Smad activation was inhibited in TGF-β signaling. After being treated with TGF-β1, pancreatic cancer cells resulted in EMT and cell migration was enhanced. Heat treatment inhibited TGF-β1-induced changes in morphology, inhibited the expression of EMT-related factors, and attenuated TGF-β1-induced migration in pancreatic cancer cells. Additionally, we observed that heat treatment blocked TGF-β1-induced phosphorylation of Smad2 in PANC-1 cells. Our results suggest that heat treatment can suppress TGF-β1-induced EMT and opens the possibility of a new therapeutic use of hyperthermia as a potential treatment for cancer metastasis.

Magnetic fluid hyperthermia inhibits the growth of breast carcinoma and downregulates vascular endothelial growth factor expression

The application of magnetic fluid hyperthermia (MFH) with nanoparticles has been shown to inhibit tumor growth in several animal models. However, the feasibility of using MFH in vivo to treat breast cancer is uncertain, and the mechanism is unclear. In the present study, it was observed that the intratumoral administration of MFH induced hyperthermia significantly in rats with Walker-265 breast carcinomas. The hyperthermia treatment with magnetic nanoparticles inhibited tumor growth in vivo and promoted the survival of the tumor-bearing rats. Furthermore, it was found that MFH treatment downregulated the protein expression of vascular endothelial growth factor (VEGF) in the tumor tissue, as observed by immunohistochemistry. MFH treatment also decreased the gene expression of VEGF and its receptors, VEGF receptor 1 and 2, and inhibited angiogenesis in the tumor tissues. Taken together, these results indicate that the application of MFH with nanoparticles is feasible for the treatment of breast carcinoma. The MFH-induced downregulation of angiogenesis may also contribute to the induction of an anti-tumor effect.

Three single nucleotide polymorphisms of the vascular endothelial growth factor (VEGF) gene and glioma risk in a Chinese population

OBJECTIVE

To investigate the association between three single nucleotide polymorphisms (SNPs) of the vascular endothelial growth factor (VEGF) gene and the risk of glioma in a Han Chinese population.

METHODS

This hospital-based case-control study used polymerase chain reaction-restriction fragment length polymorphism analysis to detect three SNPs (-634 G/C, +936 C/T and +1612 G/A) of the VEGF gene in patients with glioma compared with healthy control subjects.

RESULTS

The study investigated 880 patients with gliomas and 880 age- and sex-matched healthy control subjects. Patients with gliomas had a significantly higher frequency of the -634 CC genotype (odds ratio [OR] 1.35, 95% confidence interval [CI] 1.05, 1.75) and the +936 TT (OR 1.73, 95% CI 1.20, 2.48) genotype compared with the control subjects. Patients with glioblastomas had a significantly higher frequency of the -634 CC and +936 TT genotypes. Patients with grade IV gliomas had a significantly higher frequency of the -634 CC and +936 TT genotypes. The +1612 G/A polymorphisms were not associated with glioma risk.

CONCLUSION

The VEGF - 634 CC and +936 TT genotypes were associated with a higher risk of glioma in a Han Chinese population.

Hyperthermia inhibits hypoxia-induced epithelial-mesenchymal transition in HepG2 hepatocellular carcinoma cells

AIM: To investigate the effect of hyperthermia on hypoxia-induced epithelial-mesenchymal transition (EMT) in HepG2 hepatocellular carcinoma (HCC) cells, and its mechanism.

METHODS: Cells were treated with hyperthermia at 43 °C for 0.5 h, followed by incubation under hypoxic or normoxic conditions for 72 h. Cell morphology was observed. Expressions of E-cadherin and vimentin were determined by immunofluorescence assay or Western blot. The protein and mRNA expressions of Snail were also determined by Western blot and reverse transcription-polymerase chain reaction. Cell migratory capacity was evaluated.

RESULTS: Hypoxia induced EMT in HepG2 cells, which was evidenced by morphological, molecular and functional changes, including the formation of a spindle shape and the loss of cell contact. The expression of E-cadherin was decreased but the expression of vimentin was increased; also, the migratory capability was increased by 2.2 ± 0.20-fold as compared with normoxia. However, those effects were inhibited by hyperthermia pretreatment. Furthermore, protein synthesis and mRNA expression of Snail in the cells were enhanced by hypoxia as compared with normoxia, and also significantly inhibited by hyperthermia pretreatment.

CONCLUSION: Hyperthermia may inhibit hypoxia-induced EMT in HepG2 HCC cells, and the mechanism may involve inhibition of induced expression of Snail.

Laser-induced damage and recovery of plasmonically targeted human endothelial cells

Laser-induced techniques that employ the surface plasmon resonances of nanoparticles have recently been introduced as an effective therapeutic tool for destroying tumor cells. Here, we adopt a low-intensity laser-induced technique to manipulate the damage and repair of a vital category of noncancerous cells, human endothelial cells. Endothelial cells construct the interior of blood vessels and play a pivotal role in angiogenesis. The degree of damage and repair of the cells is shown to be influenced by laser illumination in the presence of gold nanoparticles of different morphologies, which either target the cellular membrane or are endocytosed. A pronounced influence of the plasmonic nanoparticle laser treatment on the expression of critical angiogenic genes is shown. Our results show that plasmon-mediated mild laser treatment, combined with specific targeting of cellular membranes, enables new routes for controlling cell permeability and gene regulation in endothelial cells.

Pathophysiological and vascular characteristics of tumours and their importance for hyperthermia: heterogeneity is the key issue

Tumour blood flow before and during clinically relevant mild hyperthermia exhibits pronounced heterogeneity. Flow changes upon heating are not predictable and are both spatially and temporally highly variable. Flow increases may result in improved heat dissipation to the extent that therapeutically relevant tissue temperatures may not be achieved. This holds especially true for tumours or tumour regions in which flow rates are substantially higher than in the surrounding normal tissues. Changes in tumour oxygenation tend to reflect alterations in blood flow upon hyperthermia. An initial improvement in the oxygenation status, followed by a return to baseline levels (or even a drop to below baseline at high thermal doses) has been reported for some tumours, whereas a predictable and universal occurrence of sustained increases in O(2) tensions upon mild hyperthermia is questionable and still needs to be verified in the clinical setting. Clarification of the pathogenetic mechanisms behind possible sustained increases is mandatory. High-dose hyperthermia leads to a decrease in the extracellular and intracellular pH and a deterioration of the energy status, both of which are known to be parameters capable of acting as direct sensitisers and thus pivotal factors in hyperthermia treatment. The role of the tumour microcirculatory function, hypoxia, acidosis and energy status is complex and is further complicated by a pronounced heterogeneity. These latter aspects require additional critical evaluation in clinically relevant tumour models in order for their impact on the response to heat to be clarified.

Effect of local hyperthermia on lymphangiogenic factors VEGF-C and -D in a nude mouse xenograft model of tongue squamous cell carcinoma

It is widely accepted that tumor-induced lymphangiogenesis driven by vascular endothelial growth factor (VEGF)-C- and/or VEGF-D-induced activation of VEGF receptor (VEGFR)-3 could promote lymphatic metastasis. In this study, tumor growth and intratumoral expression level of VEGF-C and -D following administration of local hyperthermia was evaluated in nude mice model of tongue squamous cell carcinoma (SCC). The data demonstrated that the size of tumor in local hyperthermia was 26.5% of control group, and that local hyperthermia markedly suppressed the mRNA and protein expression of VEGF-C and -D as determined by quantitative real-time RT-PCR, Western blot and immunohistochemistry (P<0.05). These results suggest that, accompanying with tumor growth inhibition, local hyperthermia may act as an anti-lymphangiogenic role by suppressing the expression of tumor VEGF-C and -D, and thereby inhibiting cancer cell lymphatic metastasis in tongue SCC.

Transcriptional regulation of vascular endothelial growth factor C by oxidative and thermal stress is mediated by lens epithelium-derived growth factor/p75

Vascular endothelial growth factor C (VEGF-C) plays a critical role in tumor lymphangiogenesis and lymph node metastasis. We report here that VEGF-C expression is regulated by microenvironmental stress including hyperthermia and oxidative stress. Furthermore, we show that this stress response is mediated by transcriptional activation mediated by lens epithelium-derived growth factor (LEDGF/p75). Ectopic expression of LEDGF/p75 in C6 rat glioma and in H1299 human non-small cell lung carcinoma induced VEGF-C expression in vitro, whereas in subcutaneous mouse tumor xenografts, LEDGF/p75 stimulated VEGF-C expression and augmented angiogenesis and lymphangiogenesis. Conversely, overexpression of a LEDGF/p75 native antisense or LEDGF/p75-targeted short interfering RNA downmodulated VEGF-C expression. LEDGF seemed to conferred this activity on binding to a conserved stress response element (STRE) located in the VEGF-C gene because mutating the STRE was sufficient for the suppression of basal and stress-induced activations of the VEGF-C promoter. Thus, the study reported here identified a role for LEDGF/p75 in stress-regulated transcriptional control of VEGF-C expression. These results provide a possible link for LEDGF/p75 in tumor lymphangiogenesis and cancer metastasis. Hence, our data suggest the LEDGF-VEGF-C axis as a putative biomarker for the detection of stress-induced lymphangiogenesis and LEDGF as a potential target for antimetastatic therapy.

Thermochemotherapy effect of nanosized As2O3/Fe3O4 complex on experimental mouse tumors and its influence on the expression of CD44v6, VEGF-C and MMP-9

BACKGROUND

Both thermotherapy and arsenic have been shown to be active against a broad spectrum of cancers. To reduce the limitations of conventional thermotherapy, improve therapeutic anticancer activity, reduce the toxicity of arsenic on normal tissue, and increase tissue-specific delivery, we prepared a nanosized As2O3/Fe3O4 complex (Fe3O4 magnetic nanoparticles encapsulated in As2O3). We assessed the thermodynamic characteristics of this complex and validated the hyperthermia effect, when combined with magnetic fluid hyperthermia (MFH), on xenograft HeLa cells (human cervical cancer cell line) in nude mice. We also measured the effect on the expression of CD44v6, VEGF-C, and MMP-9 which were related to cancer and/or metastasis.

RESULTS

The nanosized As2O3/Fe3O4 particles were approximately spherical, had good dispersibility as evidenced by TEM, and an average diameter of about 50 nm. With different concentrations of the nanosized As2O3/Fe3O4 complex, the correspondingsuspension of magnetic particles could attain a steady temperature ranging from 42 degrees C to 65 degrees C when placed in AMF for 40 min. Thermochemotherapy with the nanosized As2O3/Fe3O4 complex showed a significant inhibitory effect on the mass (88.21%) and volume (91.57%) of xenograft cervical tumors (p < 0.05 for each measurement, compared with control). In addition, thermochemotherapy with the nanosized As2O3/Fe3O4 complex significantly inhibited the expression of CD44v6, VEGF-C, and MMP-9 mRNA (p < 0.05 for each).

CONCLUSION

As2O3/Fe3O4 complex combined with MFH had is a promising technique for the minimally invasive elimination of solid tumors and may be have anticancerometastasic effect by inhibiting the expression of CD44v6, VEGF-C, and MMP-9.

Current status of antivascular therapy and targeted treatment in the clinic

Antivascular and targeted therapy are now an integrated part of the treatment of myelogenous leukemias, GIST tumours, B-cell lymphomas and breast cancer. In various malignancies improved responses and prolongation of survival for several months is regularly reported. The progress in this field is relevant for hyperthermia. Heat has among other effects documented antivascular effects, and can be considered as one of the established methods in the field based on several randomised phase III studies. Hyperthermia should be considered for combination with other antiangiogenic agents.

Mechanisms of Focal Heat Destruction of Liver Tumors

BACKGROUND

Focal heat destruction has emerged as an effective treatment strategy in selected patients with malignant liver tumors. Radiofrequency ablation, interstitial laser thermotherapy, and microwave treatment are currently the most widely applied thermal ablative techniques. A major limitation of these therapies is incomplete tumor destruction and overall high recurrences. An understanding of the mechanisms of tissue injury induced by focal hyperthermia is essential to ensure more complete tumor destruction. Here, the currently available scientific literature concerning the underlying mechanisms involved in the destruction of liver tumors by focal hyperthermia is reviewed.

METHODS

Medline was searched from 1960 to 2004 for literature regarding the use of focal hyperthermia for the treatment of liver tumors. All relevant literature was searched for further references.

RESULTS

Experimental evidence suggests that focal hyperthermic injury occurs in two distinct phases. The first phase results in direct heat injury that is determined by the total thermal energy applied, tumor biology, and the tumor microenvironment. Tumors are more susceptible to heat injury than normal cells as the result of specific biological features, reduced heat dissipating ability, and lower interstitial pH. The second phase of hyperthermic injury is indirect tissue damage that produces a progression of tissue injury after the cessation of the initial heat stimulus. This progressive injury may involve a balance of several factors, including apoptosis, microvascular damage, ischemia-reperfusion injury, Kupffer cell activation, altered cytokine expression, and alterations in the immune response. Blood flow modulation and administration of thermosensitizing agents are two methods currently used to increase the extent of direct thermal injury. The processes involved in the progression of thermal injury and therapies that may potentially modulate them remain poorly understood.

CONCLUSION

Focal hyperthermia for the treatment of liver tumors involves complex mechanisms. Evidence suggests that focal hyperthermia produces both direct and indirect tissue injury by differing underlying processes. Methods to enhance the effects of treatment to achieve complete tumor destruction should focus on manipulating these processes.

The effect of human tissue factor pathway inhibitor-2 on the growth and metastasis of fibrosarcoma tumors in athymic mice

Human tissue factor pathway inhibitor-2 (TFPI-2) is a matrix-associated Kunitz inhibitor that inhibits the plasmin- and trypsin-mediated activation of zymogen matrix metalloproteinases involved in tumor progression, invasion, and metastasis. To directly assess its role in tumor growth and metastasis in vivo, we stably transfected HT-1080 fibrosarcoma cells expressing either fully active wild-type human TFPI-2 (WT) or inactive R24Q TFPI-2 (QT) and examined their ability to form tumors and metastasize in athymic mice in comparison to mock-transfected cells (MT). MT and QT fibrosarcoma tumors grew 2 to 3 times larger than WT tumors. Tumor metastasis was confined to the lung and was observed in 75% of mice treated with either MT or QT cells, whereas only 42% of mice treated with WT cells developed lung metastases. Real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analyses of each tumor group revealed 3- to 6-fold lower levels of murine vascular endothelial growth factor gene expression in WT tumors in relation to either MT or QT tumors. Comparative tumor gene expression analysis revealed that several human genes implicated in oncogenesis, invasion, metastasis, apoptosis, and angiogenesis had significantly altered levels of expression in WT tumors. Our collective data demonstrate that secretion of inhibitory TFPI-2 by a highly metastatic tumor cell markedly inhibits its growth and metastasis in vivo by regulating pericellular extracellular matrix (ECM) remodeling and angiogenesis. (Blood. 2004;103:1069-1077)