Genistein promotes ionizing radiation-induced cell death by reducing cytoplasmic Bcl-xL levels in non-small cell lung cancer

Genistein Enhances TRAIL-Mediated Apoptosis Through the Inhibition of XIAP and DcR1 in Colon Carcinoma Cells Treated with 5-Fluorouracil

Objectives

Colorectal cancer is one of the most common cancers worldwide. However, surgical intervention and chemotherapy provide only limited benefits for the recovery and survival of patients. The anticarcinogenic effect of genistein has attracted attention because epidemiological studies have shown that soybean consumption is associated with a decrease in the incidence of cancer. There are limited studies on the effects of genistein in colorectal carcinoma cells. We aimed to investigate the cytotoxic, genotoxic, and apoptotic effects of genistein in SW480 and SW620 colon adenocarcinoma cells treated with 5-fluorouracil, the basis of chemotherapy, and the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) ligand, the mediator of apoptosis, both alone and in combination.

Materials and Methods

Cytotoxicity and genotoxicity were determined by MTT and comet assays, respectively. The apoptotic effects were evaluated by reverse transcription-polymerase chain reaction assay, with the additional use of Annexin V FITC, mitochondrial membrane potential (MMP), caspase 3, 8, and 9 activity, and reactive oxygen species (ROS) assay kits.

Results

According to our findings, genistein, 5-fluorouracil, and TRAIL had synergistic apoptotic effects because of DR5 upregulation, ROS production, and DNA damage, which were mediated by increased caspase-8, and -9 activity and decreased MMP.

Conclusion

The applied combinations of these compounds may contribute to the resistance problem that may occur in treating colorectal cancer, with a decrease in DcR1 and XIAP genes.

GABA(A) receptor activation drives GABARAP-Nix mediated autophagy to radiation-sensitize primary and brain-metastatic lung adenocarcinoma tumors

In non-small cell lung cancer (NSCLC) treatment, targeted therapies benefit only a subset of NSCLC, while radiotherapy responses are not durable and toxicity limits therapy. We find that a GABA(A) receptor activator, AM-101, impairs viability and clonogenicity of NSCLC primary and brain metastatic cells. Employing an ex vivo 'chip', AM-101 is as efficacious as the chemotherapeutic docetaxel, which is used with radiotherapy for advanced-stage NSCLC. In vivo , AM-101 potentiates radiation, including conferring a survival benefit to mice bearing NSCLC intracranial tumors. GABA(A) receptor activation stimulates a selective-autophagic response via multimerization of GABA(A) Receptor-Associated Protein (GABARAP), stabilization of mitochondrial receptor Nix, and utilization of ubiquitin-binding protein p62. A targeted-peptide disrupting Nix binding to GABARAP inhibits AM-101 cytotoxicity. This supports a model of GABA(A) receptor activation driving a GABARAP-Nix multimerization axis triggering autophagy. In patients receiving radiotherapy, GABA(A) receptor activation may improve tumor control while allowing radiation dose de-intensification to reduce toxicity.

Highlights

Activating GABA(A) receptors intrinsic to lung primary and metastatic brain cancer cells triggers a cytotoxic response. GABA(A) receptor activation works as well as chemotherapeutic docetaxel in impairing lung cancer viability ex vivo . GABA(A) receptor activation increases survival of mice bearing lung metastatic brain tumors.A selective-autophagic response is stimulated by GABA(A) receptor activation that includes multimerization of GABARAP and Nix.Employing a new nanomolar affinity peptide that abrogates autophagosome formation inhibits cytotoxicity elicited by GABA(A) receptor activation.

The radioprotectant nano-genistein enhances radiotherapy efficacy of lung tumors in mice

Background

Radiotherapy for non-small cell lung cancer (NSCLC) can be dose-limiting due to treatment-related toxicities. Genistein has been shown to be a robust radioprotective agent in preclinical models. A novel genistein oral nanosuspension formulation (nano-genistein) has demonstrated efficacy in mitigating radiation-induced lung damage in preclinical animal models. However, while those studies have confirmed that nano-genistein can protect normal lung tissue from radiation-induced toxicities, no studies have assessed the effect of nano-genistein on lung tumors. Here, we evaluated the impact of nano-genistein on the efficacy of radiation treatment of lung tumors in a mouse xenograft model.

Methods

Two separate studies were conducted utilizing human A549 cells implanted either dorsally within the upper torso or in the flank. Daily oral administration of nano-genistein (200 or 400 mg/kg/day) occurred prior to and after exposure to a single dose of thoracic or abdominal 12.5 Gy radiation. Tumor growth was monitored twice weekly, nano-genistein treatment continued for up to 20 weeks and histopathology of tissues was completed post euthanasia.

Results

Continuous nano-genistein dosing was safe across all study groups in both studies. Animals receiving nano-genistein better maintained body weight following irradiation compared to corresponding vehicle treated animals. Animals that received nano-genistein also had reduced tumor growth and improved normal lung histopathology compared to those receiving vehicle suggesting that nano-genistein does not protect tumors from radiotherapy but is radioprotective of the lungs. There were no treatment-related histopathological findings noted in the skin adjacent to the tumor, esophagus, or uterus.

Conclusions

These results, including the safety following extended dosing, support the continued evaluation of nano-genistein as an adjunctive treatment for patients with NSCLC undergoing radiotherapy and serve as the basis of a phase 1b/2a multicenter clinical trial.

WITHDRAWN: In vitro synergistic activity of cisplatin and EGFR-targeted nanomedicine of anti-Bcl-xL siRNA in a non-small lung cancer cell line model

This article was withdrawn from International Journal of Pharmaceutics in order to be published in International Journal of Pharmaceutics: X. The Publisher apologizes for any inconvenience this may cause.

Molecular insights and therapeutic implications of nanoengineered dietary polyphenols for targeting lung cancer: part II

Flavonoids represent a major group of polyphenolic compounds. Their capacity to inhibit tumor proliferation, cell cycle, angiogenesis, migration and invasion is substantially responsible for their chemotherapeutic activity against lung cancer. However, their clinical application is limited due to poor aqueous solubility, low permeability and quick blood clearance, which leads to their low bioavailability. Nanoengineered systems such as liposomes, nanoparticles, micelles, dendrimers and nanotubes can considerably enhance the targeted action of the flavonoids with improved efficacy and pharmacokinetic properties, and flavonoids can be successfully translated from bench to bedside through various nanoengineering approaches. This review addresses the therapeutic potential of various flavonoids and highlights the cutting-edge progress in the nanoengineered systems that incorporate flavonoids for treating lung cancer.

Evaluation of Anticancer and Cytotoxic Effects of Genistein on PC3 Prostate Cell Line under Three-Dimensional Culture Medium

Background

Prostate cancer is a major cause of disease and mortality among men. Genistein (GNT) is an isoflavone found naturally in legumes. Isoflavones, a subset of phytoestrogens, are structurally similar to mammalian estrogens. This study aimed to evaluate the anticancer and cytotoxic effects of GNT on PC3 cell line under three dimensional (3D) culture medium.

Methods

The 3D culture was created by encapsulating the PC3 cells in alginate hydrogel. MTT assay, neutral red uptake, comet assay, and cytochrome C assay were used to study the anticancer and cytotoxic effects of GNT at 120, 240, and 480 μM concentrations. Also, nitric oxide (NO), catalase, and glutathione assay levels were determined to evaluate the effect of GNT on the cellular stress. The culture medium was used as the negative control.

Results

GNT reduced the production of cellular NO and increased the production of catalase and glutathione, confirming the results of the NO test. Evaluation of the toxicity effect of GNT at the concentrations of 120, 240, and 480 μM using comet assay showed that this chemical agent induces apoptosis in PC3 cells in a dose-dependent manner. As the level of cytochrome C in PC3 cells treated with different concentrations of GNT was not significantly different from that of the control, GNT could induce apoptosis in PC3 cells through the non-mitochondrial pathway.

Conclusion

The findings of this study disclose that the anticancer effect of GNT on PC3 cells under 3D culture conditions could increase the effectiveness of treatment. Also, the cell survival rate is dependent on GNT concentration.

Genistein: Therapeutic and Preventive Effects, Mechanisms, and Clinical Application in Digestive Tract Tumor

Genistein is one of the numerous recognized isoflavones that may be found in a variety of soybeans and soy products, including tofu and tofu products. The chemical name for genistein is 4', 5, 7-trihydroxyisoflavone, and it is found in plants. In recent years, the scientific world has become more interested in genistein because of its possible therapeutic effects on many forms of cancer. It has been widely investigated for its anticancer properties. The discovery of genistein's mechanism of action indicates its potential for apoptosis induction and cell cycle arrest in gastrointestinal cancer, especially gastric and colorectal cancer. Genistein's pharmacological activities as determined by the experimental studies presented in this review lend support to its use in the treatment of gastrointestinal cancer; however, additional research is needed in the future to determine its efficacy, safety, and the potential for using nanotechnology to increase bioavailability and therapeutic efficacy.

Beneficial effects of genistein in suppression of proliferation, inhibition of metastasis, and induction of apoptosis in PC3 prostate cancer cells

OBJECTIVES

Beneficial effects of genistein have been studied in various cancer types but the underlying molecular mechanisms of its actions have not been well established. This study investigated the effects of genistein on caspase-3 and p38 mitogen-activated protein kinase (p38MAPK) as main cellular signalling targets in PC3 prostate cancer cells.

METHODS

Caspase-3 and p38MAPK gene expression and intracellular protein levels were determined. Matrix metalloproteinase-2 (MMP2) gelatinase activity and caspase-3 enzyme activity were measured and PC3 cell migration and proliferation potencies were assessed.

RESULTS

Genistein induced apoptosis by enhancing the gene expression, intracellular protein level, and enzyme activity of caspase-3. Genistein also inhibited cell proliferation by reducing p38MAPK gene expression and protein level and strongly suppressed metastatic potency of PC3 cells by reducing MMP2 activity.

CONCLUSION

Genistein exhibits its beneficial anticancer properties on PC3 cells by reducing metastatic potency and regulating caspase-3 and p38MAPK pathways at different transcriptional and protein levels.

Potential Role of Natural Products to Combat Radiotherapy and Their Future Perspectives

Cancer is the second leading cause of death in the world. Chemotherapy and radiotherapy (RT) are the common cancer treatments. In addition to these limitations, the development of adverse effects from chemotherapy and RT reduces the quality of life for cancer patients. Cellular radiosensitivity, or the ability to resist and overcome cell damage caused by ionizing radiation (IR), is directly related to cancer cells' response to RT. Therefore, radiobiological research is emphasizing chemical compounds 'radiosensitization of cancer cells so that they are more reactive in the IR spectrum. Recent years researchers have seen an increase in interest in natural products that have antitumor effects with minimal side effects. Natural products, on the other hand, are easy to recover and therefore less expensive. There have been several scientific studies done based on these compounds that have tested their ability in vitro and in vivo to induce tumor radiosensitization. The role of natural products in RT, as well as their usefulness and potential applications, is the goal of this current review.

The Sex-Related Interplay between TME and Cancer: On the Critical Role of Estrogen, MicroRNAs and Autophagy

The interplay between cancer cells and the tumor microenvironment (TME) has a fundamental role in tumor progression and response to therapy. The plethora of components constituting the TME, such as stroma, fibroblasts, endothelial and immune cells, as well as macromolecules, e.g., hormones and cytokines, and epigenetic factors, such as microRNAs, can modulate the survival or death of cancer cells. Actually, the TME can stimulate the genetically regulated programs that the cell puts in place under stress: apoptosis or, of interest here, autophagy. However, the implication of autophagy in tumor growth appears still undefined. Autophagy mainly represents a cyto-protective mechanism that allows cell survival but, in certain circumstances, also leads to the blocking of cell cycle progression, possibly leading to cell death. Since significant sex/gender differences in the incidence, progression and response to cancer therapy have been widely described in the literature, in this review, we analyzed the roles played by key components of the TME, e.g., estrogen and microRNAs, on autophagy regulation from a sex/gender-based perspective. We focused our attention on four paradigmatic and different forms of cancers-colon cancer, melanoma, lymphoma, and lung cancer-concluding that sex-specific differences may exert a significant impact on TME/cancer interaction and, thus, tumor growth.

Aberrant Bcl-x splicing in cancer: from molecular mechanism to therapeutic modulation

Bcl-x pre-mRNA splicing serves as a typical example to study the impact of alternative splicing in the modulation of cell death. Dysregulation of Bcl-x apoptotic isoforms caused by precarious equilibrium splicing is implicated in genesis and development of multiple human diseases, especially cancers. Exploring the mechanism of Bcl-x splicing and regulation has provided insight into the development of drugs that could contribute to sensitivity of cancer cells to death. On this basis, we review the multiple splicing patterns and structural characteristics of Bcl-x. Additionally, we outline the cis-regulatory elements, trans-acting factors as well as epigenetic modifications involved in the splicing regulation of Bcl-x. Furthermore, this review highlights aberrant splicing of Bcl-x involved in apoptosis evade, autophagy, metastasis, and therapy resistance of various cancer cells. Last, emphasis is given to the clinical role of targeting Bcl-x splicing correction in human cancer based on the splice-switching oligonucleotides, small molecular modulators and BH3 mimetics. Thus, it is highlighting significance of aberrant splicing isoforms of Bcl-x as targets for cancer therapy.

Flavonoids as an effective sensitizer for anti-cancer therapy: insights into multi-faceted mechanisms and applicability towards individualized patient profiles

Cost-efficacy of currently applied treatments is an issue in overall cancer management challenging healthcare and causing tremendous economic burden to societies around the world. Consequently, complex treatment models presenting concepts of predictive diagnostics followed by targeted prevention and treatments tailored to the personal patient profiles earn global appreciation as benefiting the patient, healthcare economy, and the society at large. In this context, application of flavonoids as a spectrum of compounds and their nano-technologically created derivatives is extensively under consideration, due to their multi-faceted anti-cancer effects applicable to the overall cost-effective cancer management, primary, secondary, and even tertiary prevention. This article analyzes most recently updated data focused on the potent capacity of flavonoids to promote anti-cancer therapeutic effects and interprets all the collected research achievements in the frame-work of predictive, preventive, and personalized (3P) medicine. Main pillars considered are: - Predictable anti-neoplastic, immune-modulating, drug-sensitizing effects; - Targeted molecular pathways to improve therapeutic outcomes by increasing sensitivity of cancer cells and reversing their resistance towards currently applied therapeutic modalities.

The Hallmarks of Flavonoids in Cancer

Flavonoids represent an important group of bioactive compounds derived from plant-based foods and beverages with known biological activity in cells. From the modulation of inflammation to the inhibition of cell proliferation, flavonoids have been described as important therapeutic adjuvants against several diseases, including diabetes, arteriosclerosis, neurological disorders, and cancer. Cancer is a complex and multifactor disease that has been studied for years however, its prevention is still one of the best known and efficient factors impacting the epidemiology of the disease. In the molecular and cellular context, some of the mechanisms underlying the oncogenesis and the progression of the disease are understood, known as the hallmarks of cancer. In this text, we review important molecular signaling pathways, including inflammation, immunity, redox metabolism, cell growth, autophagy, apoptosis, and cell cycle, and analyze the known mechanisms of action of flavonoids in cancer. The current literature provides enough evidence supporting that flavonoids may be important adjuvants in cancer therapy, highlighting the importance of healthy and balanced diets to prevent the onset and progression of the disease.

Capilliposide C from Lysimachia capillipes Restores Radiosensitivity in Ionizing Radiation-Resistant Lung Cancer Cells Through Regulation of ERRFI1/EGFR/STAT3 Signaling Pathway

Aims

Radiation therapy is used as the primary treatment for lung cancer. Unfortunately, radiation resistance remains to be the major clinic problem for lung cancer patients. Lysimachia capillipes capilliposide C (LC-C), an extract from LC Hemsl, has demonstrated multiple anti-cancer effects in several types of cancer. Here, we investigated the potential therapeutic impacts of LC-C on radiosensitivity in lung cancer cells and their underlying mechanisms.

Methods

Non-small cell lung cancer cell lines were initially irradiated to generate ionizing radiation (IR)-resistant lung cancer cell lines. RNA-seq analysis was used to examine the whole-transcriptome alteration in IR-resistant lung cancer cells treated with or without LC-C, and the differentially expressed genes with most significance were verified by RT-qPCR. Colony formation assays were performed to determine the effect of LC-C and the target gene ErbB receptor feedback inhibitor 1 (ERRFI1) on radiosensitivity of IR-resistant lung cancer cells. In addition, effects of ERRFI1 on cell cycle distribution, DNA damage repair activity were assessed by flow cytometry and γ-H2AX immunofluorescence staining respectively. Western blotting was performed to identify the activation of related signaling pathways. Tumor xenograft experiments were conducted to observe the effect of LC-C and ERRFI1 on radiosensitivity of IR-resistant lung cancer cells in vivo.

Results

Compared with parental cells, IR-resistant lung cancer cells were more resistant to radiation. LC-C significantly enhanced the effect of radiation in IR-resistant lung cancer cells both in vitro and in vivo and validated ERRFI1 as a candidate downstream gene by RNA-seq. Forced expression of ERRFI1 alone could significantly increase the radiosensitivity of IR-resistant lung cancer cells, while silencing of ERRFI1 attenuated the radiosensitizing function of LC-C. Accordingly, LC-C and ERRFI1 effectively inhibited IR-induced DNA damage repair, and ERRFI1 significantly induced G2/M checkpoint arrest. Additional investigations revealed that down-regulation of EGFR/STAT3 pathway played an important role in radiosensitization between ERRFI1 and LC-C. Furthermore, the high expression level of ERRFI1 was associated with high overall survival rates in lung cancer patients.

Conclusions

Treatment of LC-C may serve as a promising therapeutic strategy to overcome the radiation resistance and ERRFI1 may be a potential therapeutic target in NSCLC.

Soy isoflavone genistein inhibits hsa_circ_0031250/miR-873-5p/FOXM1 axis to suppress non-small-cell lung cancer progression

The foods of plants provide the rich nutrition and have protective function in human diseases, including cancers. Genistein is a major isoflavone constituent in soybeans, which has an anti-cancer role in non-small-cell lung cancer (NSCLC). Nevertheless, the mechanism underlying the anti-cancer function of genistein in NSCLC remains largely unknown. NSCLC cells (H292 and A549) were exposed to genistein. Circular RNA hsa_circ_0031250 (circ_0031250), microRNA (miR)-873-5p and forkhead box M1 (FOXM1) abundances were examined via quantitative reverse transcription polymerase chain reaction and Western blotting. The function of genistein, circ_0031250, miR-873-5p, and FOXM1 on NSCLC progression was investigated via Cell Counting Kit-8, colony formation, transwell well, wound healing, flow cytometry, Western blotting and xenograft model. The target relationship was analyzed by dual-luciferase reporter analysis and RNA immunoprecipitation. Results showed that genistein inhibited NSCLC cell viability in dose-time-dependent patterns. circ_0031250 abundance was elevated in NSCLC samples and cell lines, and it was reduced via genistein exposure. circ_0031250 knockdown aggravated genistein-caused suppression of cell proliferation, migration and invasion and elevation of apoptosis. miR-873-5p expression was decreased in NSCLC samples and cells. miR-873-5p was targeted via circ_0031250, and miR-873-5p knockdown attenuated the influence of circ_0031250 silence on NSCLC progression in the presence of genistein. FOXM1 was regulated via circ_0031250/miR-873-5p axis. miR-873-5p constrained cell proliferation, migration and invasion and increased apoptosis via regulating FOXM1 in genistein-treated cells. circ_0031250 knockdown enhanced the inhibitive function of genistein on NSCLC cell growth in xenograft model. Collectively, genistein repressed NSCLC progression by modulating circ_0031250/miR-873-5p/FOXM1 axis.

Controlled release of soy isoflavones from multifunctional 3D printed bone tissue engineering scaffolds

Recent challenges in post-surgical bone tumor management have elucidated the need for a multifunctional scaffold, which can be used for residual tumor-cell suppression, defect repair, and simultaneous bone regeneration. In this perspective, 3D printing allows to create a wide variety of patient-specific implant with complex porous architecture and compatible mechanical strength to that of cancellous bone. Here, a multifunctional bone graft substitute is designed by incorporating the three primary soy isoflavones: genistein, daidzein, and glycitein onto a 3D printed (3DP) tricalcium phosphate (TCP) scaffolds with designed pores, endowing them with in vitro chemopreventive, bone-cell proliferating and immune-modulatory potential. The interconnected porosity and biodegradability of 3DP TCP ceramics have allowed controlled release kinetics of genistein, daidzein and glycitein in acidic and physiological buffer medium for 16 days, which is fitted with Korsmeyer-Peppas model. Presence of genistein, a well-known natural biomolecule shows a 90% reduction in vitro osteosarcoma (MG-63) cell viability and proliferation after 11 days. Meanwhile, daidzein, the other primary isoflavone, promotes in vitro cellular attachment and enhances viability and proliferation of human fetal osteoblast cell (hFOB). Furthermore, controlled release of genistein, daidzein, and glycitein from 3DP TCP scaffold demonstrates improved hFOB cell proliferation, viability, and differentiation in a dynamic flow-perfusion bioreactor, which is utilized to better simulate the clinical microenvironment. Finally, in vivo H&E staining confirms controlled co-delivery of genistein-daidzein-glycitein from 3DP scaffold carefully modulated neutrophil recruitment to the surgery site after 24 h of implantation in a rat distal femur model. These results advance our understanding towards multipronged therapeutic approaches utilizing synthetic bone graft substitutes as a drug delivery vehicle, and more importantly, demonstrate the feasibility of localized tumor cell suppression and bone cell proliferation for post-surgical defect repair application. STATEMENT OF SIGNIFICANCE: Designed multimodal porosity of 3D printed TCP scaffold allows a controlled and sustained release of soy isoflavones, genistein, daidzein and glycitein in both physiological and acidic pH. Presence of genistein shows 90% reduction in vitro bone cancer cell viability and proliferation. Meanwhile, controlled release of genistein, daidzein, and glycitein from 3DP TCP scaffolds demonstrate improved osteoblast cell proliferation, viability, and differentiation in static and dynamic flow-perfusion bioreactor. Furthermore, H&E staining at 24 h post-surgical specimens from rat distal femur model shows neutrophil recruitment at the surgery site is significantly decreased, suggesting the anti-inflammatory property of soy isoflavones. This work provides deeper understanding on the design of a multifunctional 3D printed patient-specific scaffold with enhanced in vitro chemopreventive, osteogenic and in vivo anti-inflammatory ability.

Polyphenol-Mediated Autophagy in Cancer: Evidence of In Vitro and In Vivo Studies

One of the hallmarks of cellular transformation is the altered mechanism of cell death. There are three main types of cell death, characterized by different morphological and biochemical features, namely apoptosis (type I), autophagic cell death (type II) and necrosis (type III). Autophagy, or self-eating, is a tightly regulated process involved in stress responses, and it is a lysosomal degradation process. The role of autophagy in cancer is controversial and has been associated with both the induction and the inhibition of tumor growth. Autophagy can exert tumor suppression through the degradation of oncogenic proteins, suppression of inflammation, chronic tissue damage and ultimately by preventing mutations and genetic instability. On the other hand, tumor cells activate autophagy for survival in cellular stress conditions. Thus, autophagy modulation could represent a promising therapeutic strategy for cancer. Several studies have shown that polyphenols, natural compounds found in foods and beverages of plant origin, can efficiently modulate autophagy in several types of cancer. In this review, we summarize the current knowledge on the effects of polyphenols on autophagy, highlighting the conceptual benefits or drawbacks and subtle cell-specific effects of polyphenols for envisioning future therapies employing polyphenols as chemoadjuvants.

Organoids as Complex In Vitro Models for Studying Radiation-Induced Cell Recruitment

Patients with triple negative breast cancer (TNBC) typically receive chemotherapy, surgery, and radiation therapy. Although this treatment improves prognosis for most patients, some patients continue to experience recurrence within 5 years. Preclinical studies have shown that immune cell infiltration at the irradiated site may play a significant role in tumor cell recruitment; however, little is known about the mechanisms that govern this process. This lack of knowledge highlights the need to evaluate radiation-induced cell infiltration with models that have controllable variables and maintain biological integrity. Mammary organoids are multicellular three-dimensional (3D) in vitro models, and they have been used to examine many aspects of mammary development and tumorigenesis. Organoids are also emerging as a powerful tool to investigate normal tissue radiation damage. In this review, we evaluate recent advances in mammary organoid technology, consider the advantages of using organoids to study radiation response, and discuss future directions for the applications of this technique.

Cytoplasmic APE1 promotes resistance response in osteosarcoma patients with cisplatin treatment

Chemotherapy resistance has become a hold back and major clinical challenge in osteosarcoma cancer. The alteration and subcellular distribution of apurinic/apyrimidinic endonuclease 1 (APE1) has been reported to be involved in chemotherapy resistance in many cancers. Here, we report that the cytoplasmic distribution of APE1 plays a key role in the sensitivity of combination platinum chemotherapy in osteosarcoma. Interestingly, the prevalence of cisplatin-induced DNA damage and apoptosis in low cytoplasmic APE1 osteosarcoma cell lines was higher than in high expression of cytoplasmic APE1 cell lines. Overexpression of cytoplasmic APE1 protected the osteosarcoma cells from CDDP-induced apoptosis. In addition, clinical data also show that the level of cytoplasmic APE1 was negatively associated with sensitivity to combination chemotherapy of cisplatin in osteosarcoma patients. Our findings suggest that cytoplasmic APE1 plays a significant role in chemotherapy resistance. This role is a supplement to the extranuclear function of APE1, and cytoplasmic APE1 expression level could be a promising predictor of platinum treatment prognosis for osteosarcoma patients.

Flavonoids sensitize tumor cells to radiation: molecular mechanisms and relevance to cancer radiotherapy

Purpose: Radiobiological research continues to focus on finding newer strategies for enhanced killing of tumor cells by ionizing radiation. In recent years, chemotherapeutic drugs have been found to possess the capabilities to sensitize tumor cells without affecting the normal cells. There have been increasing research efforts to identify novel and nontoxic compounds which cause minimal or no harm to normal cells but maximize tumor toxicity response to radiation exposure. Extensive researches on flavonoids that are compounds derived from plants have shown that these have promising abilities as radioprotectors and radiosensitizers.Conclusions: In this review, we examine the role of flavonoids as potential radiosensitizers, review the underlying molecular mechanisms and discuss their potential usefulness in improving cancer radiotherapy. It is emphasized that obtaining a deeper insight into the molecular mechanisms underlying the combined action of flavonoids and ionizing radiation may provide new directions for radiobiological research applicable to the much needed enhanced selective tumor cytotoxicity to treatment agents.

Nutraceutical Compounds as Sensitizers for Cancer Treatment in Radiation Therapy

The improvement of diagnostic techniques and the efficacy of new therapies in clinical practice have allowed cancer patients to reach a higher chance to be cured together with a better quality of life. However, tumors still represent the second leading cause of death worldwide. On the contrary, chemotherapy and radiotherapy (RT) still lack treatment plans which take into account the biological features of tumors and depend on this for their response to treatment. Tumor cells' response to RT is strictly-connected to their radiosensitivity, namely, their ability to resist and to overcome cell damage induced by ionizing radiation (IR). For this reason, radiobiological research is focusing on the ability of chemical compounds to radiosensitize cancer cells so to make them more responsive to IR. In recent years, the interests of researchers have been focused on natural compounds that show antitumoral effects with limited collateral issues. Moreover, nutraceuticals are easy to recover and are thus less expensive. On these bases, several scientific projects have aimed to test also their ability to induce tumor radiosensitization both in vitro and in vivo. The goal of this review is to describe what is known about the role of nutraceuticals in radiotherapy, their use and their potential application.

Progress in Research on the Role of Flavonoids in Lung Cancer

Lung cancer is the leading cause of cancer deaths worldwide. Therefore, for the prevention, diagnosis, prognosis and treatment of lung cancer, efficient preventive strategies and new therapeutic strategies are needed to face these challenges. Natural bioactive compounds and particular flavonoids compounds have been proven to have an important role in lung cancer prevention and of particular interest is the dose used for these studies, to underline the molecular effects and mechanisms at a physiological concentration. The purpose of this review was to summarize the current state of knowledge regarding relevant molecular mechanisms involved in the pharmacological effects, with a special focus on the anti-cancer role, by regulating the coding and non-coding genes. Furthermore, this review focused on the most commonly altered and most clinically relevant oncogenes and tumor suppressor genes and microRNAs in lung cancer. Particular attention was given to the biological effect in tandem with conventional therapy, emphasizing the role in the regulation of drug resistance related mechanisms.