The schemes, mechanisms and molecular pathway changes of Tumor Treating Fields (TTFields) alone or in combination with radiotherapy and chemotherapy

Synergistic effects of combined hyperthermia and electric fields treatment in non-small cell lung-cancer (NSCLC) cell lines

PURPOSE

Lung cancer remains a leading cause of cancer-related mortality, with non-small cell lung cancer (NSCLC) being particularly challenging due to poor survival rates, emphasizing the need for new treatments. This study examined the therapeutic effects of combining hyperthermia (HT) with tumor-treating electric fields (TTF) in NSCLC.

METHODS

Cells were exposed to four different conditions: hyperthermia at 42 °C for 30 min, electric fields at 150 kHz and 0.8 V/cm for 24 h, a combination of both treatments, or no treatment (control). Cell proliferation was measured using WST and colony-formation assays, while apoptosis, DNA damage, and repair protein levels were analyzed via Western blotting. Metastatic potential was evaluated with a transwell assay, and cell migration was assessed using the wound-healing assay.

RESULTS

The combination therapy significantly inhibited colony formation and reduced cell migration and invasion more effectively than individual treatments. The combined treatment also enhanced apoptosis, as indicated by increased cleaved-PARP and Annexin V levels. In addition, the DNA-damage marker γ-H2AX was elevated, while BRCA1, a protein involved in DNA repair, was significantly downregulated compared to the individual treatments.

CONCLUSIONS

These results suggest that the enhanced anticancer effects of HT and TTF are due to increased DNA damage and suppression of DNA-repair mechanisms, highlighting the potential of this combination therapy for NSCLC treatment.

Electric Field-Induced Effects in Eukaryotic Cells: Current Progress and Limitations

Electric fields (EFs) offer a powerful tool for manipulating cells and modulating their behavior, holding significant promise for regenerative medicine and cell biology. We provide a comprehensive overview of the effects of different types of EF on eukaryotic cells with the special focus on physical mechanisms and signaling pathways involved. Direct current EF induces electrophoresis and electroosmosis, influencing cell migration, proliferation, and differentiation. Alternating current EF, through dielectric polarization and dielectrophoresis, enables cell manipulation, trapping, and sorting. Pulsed EF, particularly high-intensity, short-duration pulses, induces reversible and irreversible electroporation, facilitating drug and gene delivery. The review covers some technological aspects of EF generation, emphasizing the importance of experimental setups, and integration with microfluidic platforms for high-throughput analysis and precise manipulations. Furthermore, the synergistic potential of combining EFs with optical tweezers is highlighted, enabling fine-tuned control of cell positioning, intercellular interactions, and measurement of biophysical properties. Finally, the review addresses limitations of EF application, such as field heterogeneity and potential side effects, and outlines the directions for future studies, including developing the minimally invasive delivery methods.

Tumor Treating Fields and Combination Therapy in Management of Brain Oncology

Glioblastoma (GBM) remains a challenging cancer to treat with limited effective therapies. Standard treatments, including surgery, radiotherapy, chemotherapy, targeted therapy, and immunotherapy, offer marginal survival benefits but are often limited by side effects and drug resistance. Temozolomide is the most commonly used chemotherapy; however, resistance and lack of efficacy in recurrent GBM hinder its success. Tumor treating fields (TTFields), a novel non-invasive modality that utilizes alternating electric fields, have recently emerged as a promising treatment for GBM. TTFields work by disrupting the function of the mitotic spindle and inducing apoptosis in cancer cells. They can be especially effective when combined with other therapies. TTFields enhance drug delivery when paired with chemotherapy by increasing the permeability of the blood-brain barrier and cell membranes, leading to more effective tumor inhibition. Similarly, TTFields increase cancer cell sensitivity to radiation therapy and improve the efficacy of targeted therapies, such as sorafenib and immunotherapy, particularly in extra-cranial tumors. The Optune device, the primary medical device for TTFields' delivery, offers a convenient and versatile treatment option, allowing remote care and exhibiting fewer adverse effects. This review discusses the potential of TTFields as a valuable addition to GBM treatment, particularly in combination therapies, and highlights the device's clinical applications.

Enhanced anti-tumor effects of combined electric fields, cabozantinib, and radiation therapy in metastatic renal cell carcinoma

PURPOSE

This study aimed to evaluate the therapeutic potential of combining cabozantinib, electric fields (EFs; also called Tumor Treating Fields [TTFields]), and radiation in the treatment of metastatic renal cell carcinoma (RCC), focusing on overcoming resistance to conventional monotherapeutic regimens.

METHODS

Human renal cancer cell lines (A498, Caki-1) were treated with cabozantinib (10 µM) for at least 6 h, TTFields (200 kHz, 0.8 V/cm) for 24 h, and radiation (3 Gy), both individually and in combination. Cellular responses, including proliferation, apoptosis, and metastatic potential, were analyzed by flow cytometry and Transwell assays.

RESULTS

The combination of cabozantinib, TTFields, and radiation exhibited synergistic effects, significantly reducing cell proliferation, enhancing apoptosis, and suppressing metastatic capacity compared with individual treatments. Triple therapy resulted in marked inhibition of metastasis-related markers and changes in apoptotic profiles compared with the control group.

CONCLUSION

This multimodal therapy demonstrated superior efficacy in reducing the metastatic potential and prolonging the survival of RCC cells, offering a promising approach to overcoming treatment resistance in patients with metastatic RCC.

Tumor treating fields enhance anti-PD therapy by improving CCL2/8 and CXCL9/CXCL10 expression through inducing immunogenic cell death in NSCLC models

BACKGROUND

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. Tumor treating fields (TTFields) combined with anti-PD immunotherapy offers a promising strategy to address this issue. Nevertheless, the mechanism of action (MOA) of TTFields therapy combined with anti-PD immunotherapy in NSCLC has not been thoroughly investigated. This study aims to elucidate the MOA of the combined therapy from the aspect of improving the tumor immune microenvironment (TIME).

METHODS

Using a mouse model of NSCLC, we tested the efficacy of TTFields therapy with anti-PD-1 and anti-PD-L1 immunotherapy. By RNA-seq, the differential genes and signaling pathways between combination therapy and anti-PD therapy groups were studied. In-vitro experiments validated the effects of TTFields on tumor cells for CD4+ T cell and CD8+ T cell infiltration, as well as the expression of tumor immunogenic death related genes and chemokines.

RESULTS

Combining TTFields with anti-PD-1 reduced tumor weight and volume, respectively, compared to controls (p < 0.05). RNA-seq analysis revealed 1,745 differentially expressed genes (DEGs) in the combination therapy group versus controls, including upregulated immune pathways and immunogenic cell death (ICD) associated genes. Further study showed that the combination therapy resulted in increased T cell infiltration compared to anti-PD immunotherapy alone, and TTFields induced higher level expression of ATP, HMGB1, CCL2, CCL8, CXCL9, and CXCL10 and inflammatory cytokines than control group. These effects collectively contributed to the altered TIME, and finally potentiated the efficacy of anti-PD therapy.

CONCLUSIONS

TTFields enhance the effectiveness of anti-PD immunotherapy by improving CD4+ T cells and CD8+ T infiltration via inducing ICD to increase CCL2/8 and CXCL9/CXCL10 expression of tumor cells. This study provides theoretical basis and new insights for evaluating the effectiveness of TTFields combined with anti-PD therapy for NSCLC.

HSP27/IL-6 axis promotes OSCC chemoresistance, invasion and migration by orchestrating macrophages via a positive feedback loop

Novel strategies to disrupt tumor progression have emerged from studying the interactions between tumor cells and tumor-associated macrophages (TAMs). However, the molecular mechanisms of interactions between tumor cells and TAMs underlying oral squamous cell carcinoma (OSCC) progression have not been fully elucidated. This study explored the molecular mechanism of the HSP27/IL-6 axis in OSCC chemoresistance, invasion, and migration. Here, we demonstrated the higher expression of HSP27 in OSCC cells. Paracrine HSP27 from OSCC cells enhanced chemoresistance, invasion, migration, and EMT in OSCC by inducing M2 polarization and IL-6 secretion in TAMs. HSP27 and IL-6 established a positive feedback loop between OSCC cells and M2 TAMs. TAMs-derived IL-6 orchestrated OSCC stemness and chemoresistance through upregulating β-catenin and CD44, and enhanced OSCC invasion, migration, and EMT via autocrine HSP27/TLR4 signaling. Collectively, HSP27/IL-6 axis facilitates OSCC chemoresistance, invasion, and migration by orchestrating macrophages through a positive feedback loop. We identify the regulatory mechanism underlying the interaction and crosstalk between OSCC cells and TAMs mediated by the HSP27/IL-6 axis. Targeting the HSP27/IL-6 axis could be a promising treatment strategy for OSCC patients, potentially controlling disease progression and improving prognosis and recurrence outcomes.

Tumor Treating Fields enhance chemotherapy efficacy by increasing cellular drug uptake and retention in mesothelioma cells

Tumor Treating Fields (TTFields) applied with standard chemotherapy have been approved for the first-line treatment of unresectable pleural mesothelioma (PM), an aggressive malignancy with limited effective therapy options. In this study, we demonstrated that the simultaneous exposure to TTFields and doxorubicin or vinorelbine enhanced treatment efficacy in patient-derived PM cells by increasing intracellular drug concentrations. This was achieved by modulating several genes that encode transport proteins, such as the downregulation of P-glycoprotein (P-gp). Using specific, sensitive and quantitative analytical techniques, we observed a more than 70% increase in intracellular concentrations of doxorubicin and vinorelbine in samples treated with TTFields, and a greater than 50% increase in drug uptake in cells exposed to TTFields and pemetrexed. This result indicates that the increased drug concentration observed in TTFields treated cells is significant not only for drugs that are P-gp substrates but also suggests that TTFields could potentially affect other efflux pumps. However, the co-exposure to the drug and TTFields was critical to increasing intracellular drug levels, highlighting the necessity of concurrent use with drugs to enhance the antiproliferative effects of treatment. The in vitro findings were further corroborated by in vivo pharmacokinetic experiments in mice subcutaneously injected with epithelioid PM tumors. Indeed, a 30% increase in intratumor concentrations was observed when vinorelbine was administered with TTFields. Our findings suggest that TTFields could be a well-tolerated approach for enhancing intratumoral drug levels and potentially achieving a more significant therapeutic impact on PM treatment.

Metastatic brain tumors: from development to cutting-edge treatment

Metastatic brain tumors, also called brain metastasis (BM), represent a challenging complication of advanced tumors. Tumors that commonly metastasize to the brain include lung cancer and breast cancer. In recent years, the prognosis for BM patients has improved, and significant advancements have been made in both clinical and preclinical research. This review focuses on BM originating from lung cancer and breast cancer. We briefly overview the history and epidemiology of BM, as well as the current diagnostic and treatment paradigms. Additionally, we summarize multiomics evidence on the mechanisms of tumor occurrence and development in the era of artificial intelligence and discuss the role of the tumor microenvironment. Preclinically, we introduce the establishment of BM models, detailed molecular mechanisms, and cutting-edge treatment methods. BM is primarily treated with a comprehensive approach, including local treatments such as surgery and radiotherapy. For lung cancer, targeted therapy and immunotherapy have shown efficacy, while in breast cancer, monoclonal antibodies, tyrosine kinase inhibitors, and antibody-drug conjugates are effective in BM. Multiomics approaches assist in clinical diagnosis and treatment, revealing the complex mechanisms of BM. Moreover, preclinical agents often need to cross the blood-brain barrier to achieve high intracranial concentrations, including small-molecule inhibitors, nanoparticles, and peptide drugs. Addressing BM is imperative.

Emerging cancer therapies: targeting physiological networks and cellular bioelectrical differences with non-thermal systemic electromagnetic fields in the human body - a comprehensive review

A steadily increasing number of publications support the concept of physiological networks, and how cellular bioelectrical properties drive cell proliferation and cell synchronization. All cells, especially cancer cells, are known to possess characteristic electrical properties critical for physiological behavior, with major differences between normal and cancer cell counterparts. This opportunity can be explored as a novel treatment modality in Oncology. Cancer cells exhibit autonomous oscillations, deviating from normal rhythms. In this context, a shift from a static view of cellular processes is required for a better understanding of the dynamic connections between cellular metabolism, gene expression, cell signaling and membrane polarization as states in constant flux in realistic human models. In oncology, radiofrequency electromagnetic fields have produced sustained responses and improved quality of life in cancer patients with minimal side effects. This review aims to show how non-thermal systemic radiofrequency electromagnetic fields leads to promising therapeutic responses at cellular and tissue levels in humans, supporting this newly emerging cancer treatment modality with early favorable clinical experience specifically in advanced cancer.

Electrical excitability of cancer cells-CELEX model updated

The normal functioning of every cell in the body depends on its bioelectric properties and many diseases are caused by genetic and/or epigenetic dysregulation of the underlying ion channels. Metastasis, the main cause of death from cancer, is a complex multi-stage process in which cells break away from a primary tumour, invade the surrounding tissues, enter the circulation by encountering a blood vessel and spread around the body, ultimately lodging in distant organs and reproliferating to form secondary tumours leading to devastating organ failure. Such cellular behaviours are well known to involve ion channels. The CELEX model offers a novel insight to metastasis where it is the electrical excitation of the cancer cells that is responsible for their aggressive and invasive behaviour. In turn, the hyperexcitability is underpinned by concomitant upregulation of functional voltage-gated sodium channels and downregulation of voltage-gated potassium channels. Here, we update the in vitro and in vivo evidence in favour of the CELEX model for carcinomas. The results are unequivocal for the sodium channel. The potassium channel arm is also broadly supported by existing evidence although these data are complicated by the impact of the channels on the membrane potential and consequent secondary effects. Finally, consistent with the CELEX model, we show (i) that carcinomas are indeed electrically excitable and capable of generating action potentials and (ii) that combination of a sodium channel inhibitor and a potassium channel opener can produce a strong, additive anti-invasive effect. We discuss the possible clinical implications of the CELEX model in managing cancer.

Prediction of intracranial electric field strength and analysis of treatment protocols in tumor electric field therapy targeting gliomas of the brain

BACKGROUND AND OBJECTIVE

Tumor Electric Field Therapy (TEFT) is a new treatment for glioblastoma cells with significant effect and few side effects. However, it is difficult to directly measure the intracranial electric field generated by TEFT, and the inability to control the electric field intensity distribution in the tumor target area also limits the clinical therapeutic effect of TEFT. It is a safe and effective way to construct an efficient and accurate prediction model of intracranial electric field intensity of TEFT by numerical simulation.

METHODS

Different from the traditional methods, in this study, the brain tissue was segmented based on the MRI data of patients with retained spatial location information, and the spatial position of the brain tissue was given the corresponding electrical parameters after segmentation. Then, a single geometric model of the head profile with the transducer array is constructed, which is assembled with an electrical parameter matrix containing tissue position information. After applying boundary conditions on the transducer, the intracranial electric field intensity could be solved in the frequency domain. The effects of transducer array mode, load voltage and voltage frequency on the intracranial electric field strength were further analyzed. Finally, planning system software was developed for optimizing TEFT treatment regimens for patients.

RESULTS

Experimental validation and comparison with existing results demonstrate the proposed method has a more efficient and pervasive modeling approach with higher computational accuracy while preserving the details of MRI brain tissue structure completely. In the optimization analysis of treatment protocols, it was found that increasing the load voltage could effectively increase the electric field intensity in the target area, while the effect of voltage frequency on the electric field intensity was very limited.

CONCLUSIONS

The results showed that adjusting the transducer array mode was the key method for making targeted treatment plans. The proposed method is capable prediction of intracranial electric field strength with high accuracy and provide guidance for the design of the TEFT therapy process. This study provides a valuable reference for the application of TEFT in clinical practice.

Disrupting glioblastoma networks with tumor treating fields (TTFields) in in vitro models

PURPOSE

This study investigates the biological effect of Tumor Treating Fields (TTFields) on key drivers of glioblastoma's malignancy-tumor microtube (TM) formation-and on the function and overall integrity of the tumor cell network.

METHOD

Using a two-dimensional monoculture GB cell network model (2DTM) of primary glioblastoma cell (GBC) cultures (S24, BG5 or T269), we evaluated the effects of TTFields on cell density, interconnectivity and structural integrity of the tumor network. We also analyzed calcium (Ca2+) transient dynamics and network morphology, validating findings in patient-derived tumoroids and brain tumor organoids.

RESULTS

In the 2DTM assay, TTFields reduced cell density by 85-88% and disrupted network interconnectivity, particularly in cells with multiple TMs. A "crooked TM" phenotype emerged in 5-6% of treated cells, rarely seen in controls. Ca2+ transients were significantly compromised, with global Ca2+ activity reduced by 51-83%, active and periodic cells by over 50%, and intercellular co-activity by 52% in S24, and almost completely in BG5 GBCs. The effects were more pronounced at 200 kHz compared to a 50 kHz TTFields. Similar reductions in Ca2+ activity were observed in patient-derived tumoroids. In brain tumor organoids, TTFields significantly reduced tumor cell proliferation and infiltration.

CONCLUSION

Our comprehensive study provides new insights into the multiple effects of Inovitro-modeled TTFields on glioma progression, morphology and network dynamics in vitro. Future in vivo studies to verify our in vitro findings may provide the basis for a deeper understanding and optimization of TTFields as a therapeutic modality in the treatment of GB.

Current status and research progress of minimally invasive treatment of glioma

Glioma has a high malignant degree and poor prognosis, which seriously affects the prognosis of patients. Traditional treatment methods mainly include craniotomy tumor resection, postoperative radiotherapy and chemotherapy. Although above methods have achieved remarkable curative effect, they still have certain limitations and adverse reactions. With the introduction of the concept of minimally invasive surgery and its clinical application as well as the development and progress of imaging technology, minimally invasive treatment of glioma has become a research hotspot in the field of neuromedicine, including photothermal treatment, photodynamic therapy, laser-induced thermal theraphy and TT-Fields of tumor. These therapeutic methods possess the advantages of precision, minimally invasive, quick recovery and significant curative effect, and have been widely used in clinical practice. The purpose of this review is to introduce the progress of minimally invasive treatment of glioma in recent years and the achievements and prospects for the future.

Understanding the immunosuppressive microenvironment of glioma: mechanistic insights and clinical perspectives

Glioblastoma (GBM), the predominant and primary malignant intracranial tumor, poses a formidable challenge due to its immunosuppressive microenvironment, thereby confounding conventional therapeutic interventions. Despite the established treatment regimen comprising surgical intervention, radiotherapy, temozolomide administration, and the exploration of emerging modalities such as immunotherapy and integration of medicine and engineering technology therapy, the efficacy of these approaches remains constrained, resulting in suboptimal prognostic outcomes. In recent years, intensive scrutiny of the inhibitory and immunosuppressive milieu within GBM has underscored the significance of cellular constituents of the GBM microenvironment and their interactions with malignant cells and neurons. Novel immune and targeted therapy strategies have emerged, offering promising avenues for advancing GBM treatment. One pivotal mechanism orchestrating immunosuppression in GBM involves the aggregation of myeloid-derived suppressor cells (MDSCs), glioma-associated macrophage/microglia (GAM), and regulatory T cells (Tregs). Among these, MDSCs, though constituting a minority (4-8%) of CD45+ cells in GBM, play a central component in fostering immune evasion and propelling tumor progression, angiogenesis, invasion, and metastasis. MDSCs deploy intricate immunosuppressive mechanisms that adapt to the dynamic tumor microenvironment (TME). Understanding the interplay between GBM and MDSCs provides a compelling basis for therapeutic interventions. This review seeks to elucidate the immune regulatory mechanisms inherent in the GBM microenvironment, explore existing therapeutic targets, and consolidate recent insights into MDSC induction and their contribution to GBM immunosuppression. Additionally, the review comprehensively surveys ongoing clinical trials and potential treatment strategies, envisioning a future where targeting MDSCs could reshape the immune landscape of GBM. Through the synergistic integration of immunotherapy with other therapeutic modalities, this approach can establish a multidisciplinary, multi-target paradigm, ultimately improving the prognosis and quality of life in patients with GBM.

Advancements and current trends in tumor treating fields: a scientometric analysis

Tumor treating fields (TTFields) therapy is a novel and effective noninvasive cancer therapy, and it has been approved by FDA in the treatment of recurrent and newly diagnosed glioblastoma, and malignant pleural mesothelioma. Moreover, TTFields therapy has been widely studied in both clinical trials and preclinical studies in recent years. Based on its high efficacy, research on TTFields therapy has been a hot topic. Thus, the authors made this scientometric analysis of TTfields to reveal the scientometric distributions such as annual publications and citations, countries and institutions, authors, journals, references, and more importantly, research status and hot topics of the field. In recent years, publication numbers have been stable at high values, and citation numbers have been increasing greatly. The United States and Israel were the top two countries with the highest publication numbers, followed by Germany and Switzerland. Scientometric analyses of keywords indicated that clinical applications and antitumor mechanisms are probably the two main parts of current research on TTfields. Most clinical trials of TTfields focus on the treatment of glioblastoma. And a variety of other cancers such as lung cancer especially nonsmall cell lung cancer, hepatic cancer, other brain tumors, etc. have also been studied in both clinical trials and preclinical studies.

Advanced tumor electric fields therapy: A review of innovative research and development and prospect of application in glioblastoma

BACKGROUND

Glioblastoma multiforme (GBM) is an aggressive malignant tumor with a high mortality rate and is the most prevalent primary intracranial tumor that remains incurable. The current standard treatment, which involves surgery along with concurrent radiotherapy and chemotherapy, only yields a survival time of 14-16 months. However, the introduction of tumor electric fields therapy (TEFT) has provided a glimmer of hope for patients with newly diagnosed and recurrent GBM, as it has been shown to extend the median survival time to 20 months. The combination of TEFT and other advanced therapies is a promising trend in the field of GBM, facilitated by advancements in medical technology.

AIMS

In this review, we provide a concise overview of the mechanism and efficacy of TEFT. In addition, we mainly discussed the innovation of TEFT and our proposed blueprint for TEFT implementation.

CONCLUSION

Tumor electric fields therapy is an effective and highly promising treatment modality for GBM. The full therapeutic potential of TEFT can be exploited by combined with other innovative technologies and treatments.

Glioblastoma Therapy: Past, Present and Future

Glioblastoma (GB) stands out as the most prevalent and lethal form of brain cancer. Although great efforts have been made by clinicians and researchers, no significant improvement in survival has been achieved since the Stupp protocol became the standard of care (SOC) in 2005. Despite multimodality treatments, recurrence is almost universal with survival rates under 2 years after diagnosis. Here, we discuss the recent progress in our understanding of GB pathophysiology, in particular, the importance of glioma stem cells (GSCs), the tumor microenvironment conditions, and epigenetic mechanisms involved in GB growth, aggressiveness and recurrence. The discussion on therapeutic strategies first covers the SOC treatment and targeted therapies that have been shown to interfere with different signaling pathways (pRB/CDK4/RB1/P16ink4, TP53/MDM2/P14arf, PI3k/Akt-PTEN, RAS/RAF/MEK, PARP) involved in GB tumorigenesis, pathophysiology, and treatment resistance acquisition. Below, we analyze several immunotherapeutic approaches (i.e., checkpoint inhibitors, vaccines, CAR-modified NK or T cells, oncolytic virotherapy) that have been used in an attempt to enhance the immune response against GB, and thereby avoid recidivism or increase survival of GB patients. Finally, we present treatment attempts made using nanotherapies (nanometric structures having active anti-GB agents such as antibodies, chemotherapeutic/anti-angiogenic drugs or sensitizers, radionuclides, and molecules that target GB cellular receptors or open the blood-brain barrier) and non-ionizing energies (laser interstitial thermal therapy, high/low intensity focused ultrasounds, photodynamic/sonodynamic therapies and electroporation). The aim of this review is to discuss the advances and limitations of the current therapies and to present novel approaches that are under development or following clinical trials.

Glioblastoma behavior study under different frequency electromagnetic field

The tumor-treating fields (TTFields) technology has revolutionized the management of recurrent and newly diagnosed glioblastoma (GBM) cases. To ameliorate this treatment modality for GBM and other oncological conditions, it is necessary to understand the biophysical principles of TTFields better. In this study, we further analyzed the mechanism of the electromagnetic exposure with varying frequencies and electric field strengths on cells in mitosis, specifically in telophase. In reference to previous studies, an intuitive finite element model of the mitotic cell was built for electromagnetic simulations, predicting a local increase in the cleavage furrow region, which may help explain TTFields' anti-proliferative effects. Cell experiments confirmed that the reduction in proliferation and migration of glioma cell by TTFields was in a frequency- and field-strength-dependent manner. This work provides unique insights into the selection of frequencies in the anti-proliferative effect of TTFields on tumors, which could improve the application of TTFields.

Enhancing glioblastoma treatment through the integration of tumor-treating fields

Glioblastoma (GBM) represents a significant therapeutic challenge due to its aggressive nature. Tumor Treating Fields (TTFields) present a promising approach to GBM therapy. The primary mechanism of TTFields, an antimitotic effect, alongside numerous indirect effects including increased cell membrane permeability, signifies their potential in combination with other treatment modalities. Current combinations often include chemotherapy, particularly with temozolomide (TMZ), however, emerging data suggests potential synergy with targeted therapies, radiotherapy, and immunotherapy as well. TTFields display minimal side effects, predominantly skin-related, posing no significant barrier to combined therapies. The effectiveness of TTFields in GBM treatment has been demonstrated through several post-registration studies, advocating for continued research to optimize overall survival (OS) and progression-free survival (PFS) in patients, as opposed to focusing solely on quality of life.

Research progress in nucleus-targeted tumor therapy

The nucleus is considered the most important organelle in the cell as it plays a central role in controlling cell reproduction, metabolism, and the cell cycle. The successful delivery of drugs into the nucleus can achieve excellent therapeutic effects, which reveals the potential of nucleus-targeted therapy in precision medicine. However, the transportation of therapeutics into the nucleus remains a significant challenge due to various biological barriers. Herein, we summarize the recent progress in the nucleus-targeted drug delivery system (NDDS). The structures of the nucleus and nuclear envelope are first described in order to understand the mechanisms by which drugs cross the nuclear envelope. Then, various drug delivery strategies based on the mechanisms and their applications are discussed. Finally, the challenges and solutions in the field of nucleus-targeted drug delivery are raised for developing a more efficient NDDS and promoting its clinical transformation.

A review of tumor treating fields (TTFields): advancements in clinical applications and mechanistic insights

BACKGROUND

Tumor Treating Fields (TTFields) is a non-invasive modality for cancer treatment that utilizes a specific sinusoidal electric field ranging from 100 kHz to 300 kHz, with an intensity of 1 V/cm to 3 V/cm. Its purpose is to inhibit cancer cell proliferation and induce cell death. Despite promising outcomes from clinical trials, TTFields have received FDA approval for the treatment of glioblastoma multiforme (GBM) and malignant pleural mesothelioma (MPM). Nevertheless, global acceptance of TTFields remains limited. To enhance its clinical application in other types of cancer and gain a better understanding of its mechanisms of action, this review aims to summarize the current research status by examining existing literature on TTFields' clinical trials and mechanism studies.

CONCLUSIONS

Through this comprehensive review, we seek to stimulate novel ideas and provide physicians, patients, and researchers with a better comprehension of the development of TTFields and its potential applications in cancer treatment.

Effectiveness of tumor‑treating fields to reduce the proliferation and migration of liposarcoma cell lines

Liposarcoma (LPS) is a rare type of soft tissue sarcoma that constitutes 20% of all sarcoma cases in adults. Effective therapeutic protocols for human LPS are not well-defined. Tumor-treating fields (TTFields) are a novel and upcoming field for antitumor therapy. TTFields combined with chemoradiotherapy have proven to be more effective than TTFields combined with radiotherapy or chemotherapy alone. The present study aimed to assess the effectiveness of TTFields in inhibiting cell proliferation and viability for the anticancer treatment of LPS. The present study used TTFields (frequency, 150 kHz; intensity, 1.0 V/cm) to treat two LPS cell lines (94T778 and SW872) and analyzed the antitumor effects. According to trypan blue and MTT assay results, TTFields markedly reduced the viability and proliferation of LPS cell lines along with the formation of colonies in three-dimensional culture. Based on the Transwell chamber assay, TTFields treatment also markedly reduced the migration of LPS cells. Furthermore, as shown by the higher activation of caspase-3 in the Caspase-3 activity assay and the results of the reactive oxygen species (ROS) assay, TTFields increased the formation of ROS in the cells and enhanced the proportion of apoptotic cells. The present study also investigated the inhibitory effect of TTFields in combination with doxorubicin (DOX) on the migratory capacity of tumor cells. The results demonstrated that TTFields treatment synergistically induced the ROS-induced apoptosis of LPS cancer cell lines and inhibited their migratory behavior. In conclusion, the present study demonstrated the potential of TTFields in improving the sensitivity of LPS cancer cells, which may lay the foundation for future clinical trials of this combination treatment strategy.

Aurora B Kinase Inhibition by AZD1152 Concomitant with Tumor Treating Fields Is Effective in the Treatment of Cultures from Primary and Recurrent Glioblastomas

Tumor Treating Fields (TTFields) were incorporated into the treatment of glioblastoma, the most malignant brain tumor, after showing an effect on progression-free and overall survival in a phase III clinical trial. The combination of TTFields and an antimitotic drug might further improve this approach. Here, we tested the combination of TTFields with AZD1152, an Aurora B kinase inhibitor, in primary cultures of newly diagnosed (ndGBM) and recurrent glioblastoma (rGBM). AZD1152 concentration was titrated for each cell line and 5-30 nM were used alone or in addition to TTFields (1.6 V/cm RMS; 200 kHz) applied for 72 h using the inovitro™ system. Cell morphological changes were visualized by conventional and confocal laser microscopy. The cytotoxic effects were determined by cell viability assays. Primary cultures of ndGBM and rGBM varied in p53 mutational status; ploidy; EGFR expression and MGMT-promoter methylation status. Nevertheless; in all primary cultures; a significant cytotoxic effect was found following TTFields treatment alone and in all but one, a significant effect after treatment with AZD1152 alone was also observed. Moreover, in all primary cultures the combined treatment had the most pronounced cytotoxic effect in parallel with morphological changes. The combined treatment of TTFields and AZD1152 led to a significant reduction in the number of ndGBM and rGBM cells compared to each treatment alone. Further evaluation of this approach, which has to be considered as a proof of concept, is warranted, before entering into early clinical trials.