Inflammation-induced radioresistance is mediated by ROS-dependent inactivation of protein phosphatase 1 in non-small cell lung cancer cells

MicroRNA155 in non-small cell lung cancer: a potential therapeutic target

Lung cancer (LC) is the second most commonly diagnosed cancer among both men and women, and it stands as the leading cause of cancer-related mortality, characterized by high rates of morbidity and mortality. Among its subtypes, non-small cell lung cancer (NSCLC) is the most prevalent and one of the most challenging malignant tumors to treat. To date, various therapeutic approaches, including surgery, radiotherapy, and chemotherapy, have been employed in the management of lung cancer; however, due to its aggressive nature, the survival rates remain low. Consequently, exploring novel treatment strategies is of paramount importance. MicroRNAs (miRNAs), a large family of non-coding RNAs, play crucial roles in regulating several key biological processes, including cell proliferation, differentiation, inflammation, and apoptosis. Among these, microRNA155(miR-155) is one of the most conserved and versatile miRNAs, predominantly overexpressed in various diseases, including malignant tumors. This review elucidates the biological functions and roles of miR-155 in NSCLC and discusses its potential significance as a therapeutic target for future research directions and clinical applications.

The effect and mechanism of atorvastatin regulating PI3K-Akt-mTOR pathway on radiosensitivity of hepatocellular carcinoma cells

Radiation therapy is an important method to treat liver cancer, but because of the strong DNA repair ability of liver cancer cells, even after receiving high doses of radiation still can not get satisfactory results. Atorvastatin (ATO) is a lipophilic and tissue-selective inhibitor of HMG-CoA reductase whose anticancer effects have been validated in various cells, but its effect on the radiation sensitivity of hepatocellular carcinoma cells remains unclear. Therefore, Therefore, this study explored the radiosensitivity of ATO and its possible mechanism by pretreating HepG2 with ATO and collecting HepG2 cells after irradiation. It was found that atorvastatin can not only affect the survival of liver cancer cells when used alone, but also enhance the radiation sensitivity of HepG2 cells. The study found that ATO significantly exacerbated the inhibitory effects of IR on the growth, proliferation, and migration of HepG2 cells. Measurement of ROS, SOD, GPx, and MDA levels indicated that ATO enhanced IR-induced oxidative stress, further promoted the decrease of Mitochondrial Membrane Potential, increased the rate of apoptosis in HepG2, upregulating pro-apoptotic proteins Bax and Cleaved-Caspase 3, and downregulating anti-apoptotic proteins Bcl-2. Western blot analysis showed that the PI3K-Akt-mTOR pathway was inhibited, leading to the activation of cytotoxic autophagy in HepG2 and an increase in the expression of the LC-3II protein. In summary, ATO, in combination with IR, enhances the oxidative stress response of HepG2 induced by IR, promotes autophagy by inhibiting the PI3K-Akt-mTOR pathway, and thereby potentially enhances the radiosensitivity of HepG2 as a pharmacological intervention.

Epigenetic Regulation of Nuclear Factor Erythroid-2-Related Factor 2 in Colorectal Cancer Cells Resistant to Ionizing Radiation

γ-Radiation resistance is a major obstacle to the success of radiotherapy in colorectal cancer. Antioxidant-related factors contribute to resistance to radiation therapy and, therefore, are targets for improving the therapeutic response. In this study, we evaluated the molecular mechanisms underlying γ-radiation resistance using the colorectal cancer cell line SNUC5 and γ-radiation-resistant variant SNUC5/RR, including analyses of the role of nuclear factor erythroid 2-related factor 2 (NRF2), a transcription factor that regulates antioxidant enzymes, and related epigenetic regulators. Reactive oxygen species (ROS) levels, antioxidant enzyme expression, NRF2 expression, and nuclear translocation were higher in SNUC5/RR cells irradiated with or without 8 Gy than in SNUC5 cells. The DNA demethylase ten-eleven translocation 1 (TET1) expression and TET1 binding to the NRF2 promoter in SNUC5/RR cells were stronger than those in SNUC5 cells, indicating lower methylation of CpG islands in the NRF2 promoter. TET1 knockdown in SNUC5/RR cells suppressed NRF2 expression significantly. Additionally, histone mixed-lineage leukemia (MLL), a histone methyltransferase, was upregulated, leading to increased trimethylation of histone H3 lysine 4, whereas enhancer of zeste homolog 2 (EZH2), a histone methyltransferase, was downregulated, leading to decreased trimethylation of histone H3 lysine 27. Histone deacetylase (HDAC) and histone acetyltransferase (HAT) levels were lower and higher in SNUC5/RR cells than in SNUC5 cells, respectively. MLL and HAT knockdown in SNUC5/RR cells irradiated with or without 8 Gy decreased levels of NRF2 and heme-oxygenase 1, resulting in enhanced γ-radiation sensitivity. These findings support NRF2 as a target for improving the response to radiotherapy in patients with colorectal cancer.

Targeting Radiation Resistance in Oesophageal Adenocarcinoma with Pyrazinib-Functionalised Gold Nanoparticles

Background/Objectives: Only 20-30% of oesophageal adenocarcinoma (OAC) patients achieve a complete response to neoadjuvant chemo-radiotherapy for locally advanced tumours. Enhancing the response to radiation therapy is critical for improving outcomes in this aggressive cancer. Pyrazinib (P3) is a promising compound with radiosensitizing, anti-angiogenic, anti-inflammatory, and anti-metabolic properties. However, its limited solubility and bioavailability have hindered its therapeutic potential.

METHODS

To overcome these limitations, pyrazinib was conjugated with gold nanoparticles (AuNP-P3), creating a novel formulation designed to enhance solubility, maintain bioactivity, and enable targeted delivery to tumour sites.

RESULTS

In an isogenic model of OAC radioresistance, AuNP-P3 significantly reduced the surviving fraction following irradiation, demonstrating its radiosensitizing properties. It also reduced mitochondrial metabolism and modulated the secretion of inflammatory mediators in both in vitro models of OAC radioresistance and human ex vivo OAC tumour explants. Furthermore, AuNP-P3 exhibited potent anti-angiogenic activity, significantly inhibiting blood vessel formation in vivo using zebrafish embryo models.

CONCLUSIONS

These results collectively confirm that P3, in its conjugated formulation with gold nanoparticles, retains its therapeutic properties, highlighting the potential of AuNP-P3 as a novel therapeutic radiosensitizer for oesophageal adenocarcinoma and supporting its further development for clinical applications.

Nano-sensitizer with self-amplified drug release and hypoxia normalization properties potentiates efficient chemoradiotherapy of pancreatic cancer

The hypoxic nature of pancreatic cancer, one of the most lethal malignancies worldwide, significantly impedes the effectiveness of chemoradiotherapy. Although the development of oxygen carriers and hypoxic sensitizers has shown promise in overcoming tumor hypoxia. The heterogeneity of hypoxia-primarily caused by limited oxygen penetration-has posed challenges. In this study, we designed a hypoxia-responsive nano-sensitizer by co-loading tirapazamine (TPZ), KP372-1, and MK-2206 in a metronidazole-modified polymeric vesicle. This nano-sensitizer relies on efficient endogenous NAD(P)H quinone oxidoreductase 1-mediated redox cycling induced by KP372-1, continuously consuming periphery oxygen and achieving evenly distributed hypoxia. Consequently, the normalized tumor microenvironment facilitates the self-amplified release and activation of TPZ without requiring deep penetration. The activated TPZ and metronidazole further sensitize radiotherapy, significantly reducing the radiation dose needed for extensive cell damage. Additionally, the coloaded MK-2206 complements inhibition of therapeutic resistance caused by Akt activation, synergistically enhancing the hypoxic chemoradiotherapy. This successful hypoxia normalization strategy not only overcomes hypoxia resistance in pancreatic cancer but also provides a potential universal approach to sensitize hypoxic tumor chemoradiotherapy by reshaping the hypoxic distribution.

Molecular Mechanism of Radioresponsiveness in Colorectal Cancer: A Systematic Review

Background/Objectives: Colorectal cancer (CRC) is the third most diagnosed cancer globally. Radiotherapy is a common treatment strategy for patients but factors such as gene expressions and molecular mechanism effects may affect tumor radioresponse. The aim of this review is to systematically identify genes suggested to have molecular mechanism effects on the radioresponsiveness of CRC patients. Methods: By following the PRISMA guidelines, a comprehensive literature search was conducted on Pubmed, EMBASE and Cochrane Library. After exclusion and inclusion criteria sorting and critical appraisal for study quality, data were extracted from seven studies. A gene set analysis was conducted on reported genes. Results: From the seven studies, 56 genes were found to have an effect on CRC radioresponsiveness. Gene set analysis show that out of these 56 genes, 24 genes have roles in pathways which could affect cancer radioresponse. These are AKT1, APC, ATM, BRAF, CDKN2A, CTNNB1, EGFR, ERBB2, FLT3, KRAS, MET, mTOR, MYC, NFKB1, KRAS, PDGFRA, PIK3CA, PTEN, PTGS1, PTGS2, RAF1, RET, SMAD4 and TP53. The current project was conducted between the period May 2024 to August 2024. Conclusions: The current review systematically presented 56 genes which have been reported to be related to RT or CRT treatment effectiveness in rectal cancer patients. Gene set analysis shows that nearly half of the genes were involved in apoptosis, DNA damage response and repair, inflammation and cancer metabolism molecular pathways that could affect cancer radioresponse. The gene cohort identified in this study may be used as a foundation for future works focusing on the molecular mechanism of specific pathways contributing to the radioresponse of CRC.

CAVPENET Peptide Inhibits Prostate Cancer Cells Proliferation and Migration through PP1γ-Dependent Inhibition of AKT Signaling

Protein phosphatase 1 (PP1) complexes have emerged as promising targets for anticancer therapies. The ability of peptides to mimic PP1-docking motifs, and so modulate interactions with regulatory factors, has enabled the creation of highly selective modulators of PP1-dependent cellular processes that promote tumor growth. The major objective of this study was to develop a novel bioactive cell-penetrating peptide (bioportide), which, by mimicking the PP1-binding motif of caveolin-1 (CAV1), would regulate PP1 activity, to hinder prostate cancer (PCa) progression. The designed bioportide, herein designated CAVPENET, and a scrambled homologue, were synthesized using microwave-assisted solid-phase methodologies and evaluated using PCa cell lines. Our findings indicate that CAVPENET successfully entered PCa cells to influence both viability and migration. This tumor suppressor activity of CAVPENET was attributed to inhibition of AKT signaling, a consequence of increased PP1γ activity. This led to the suppression of glycolytic metabolism and alteration in lipid metabolism, collectively representing the primary mechanism responsible for the anticancer properties of CAVPENET. Our results underscore the potential of the designed peptide as a novel therapy for PCa patients, setting the stage for further testing in more advanced models to fully realize its therapeutic promise.

The Radioprotective Effect of LBP on Neurogenesis and Cognition after Acute Radiation Exposure

BACKGROUND

Radiation exposure has been linked to the development of brain damage and cognitive impairment, but the protective effect and mechanism of Lycium barbarum pills (LBP) on radiation-induced neurological damage remains to be clarified.

METHODS

Behavioral tests and immunohistochemical studies were conducted to evaluate the protective effects of LBP extract (10 g/kg orally daily for 4 weeks) against radiation-induced damage on neurogenesis and cognitive function in Balb/c mice exposed to 5.5 Gy X-ray acute radiation.

RESULTS

The results showed that the LBP extract significantly improved body weight loss, locomotor activity and spatial learning and memory. Immunohistochemical tests revealed that the LBP extract prevented the loss of proliferating cells, newly generated neurons and interneurons, especially in the subgranular area of the dentate gyrus.

CONCLUSION

The findings suggest that LBP is a potential neuroprotective drug for mitigating radiation-induced neuropsychological disorders.

Molecular mechanisms of tumor resistance to radiotherapy

BACKGROUND

Cancer is the most prevalent cause of death globally, and radiotherapy is considered the standard of care for most solid tumors, including lung, breast, esophageal, and colorectal cancers and glioblastoma. Resistance to radiation can lead to local treatment failure and even cancer recurrence.

MAIN BODY

In this review, we have extensively discussed several crucial aspects that cause resistance of cancer to radiation therapy, including radiation-induced DNA damage repair, cell cycle arrest, apoptosis escape, abundance of cancer stem cells, modification of cancer cells and their microenvironment, presence of exosomal and non-coding RNA, metabolic reprogramming, and ferroptosis. We aim to focus on the molecular mechanisms of cancer radiotherapy resistance in relation to these aspects and to discuss possible targets to improve treatment outcomes.

CONCLUSIONS

Studying the molecular mechanisms responsible for radiotherapy resistance and its interactions with the tumor environment will help improve cancer responses to radiotherapy. Our review provides a foundation to identify and overcome the obstacles to effective radiotherapy.

Elucidations of Molecular Mechanism and Mechanistic Effects of Environmental Toxicants in Neurological Disorders

Due to rising environmental and global public health concerns associated with environmental contamination, human populations are continually being exposed to environmental toxicants, including physical chemical mutagens widespread in our environment causing adverse consequences and inducing a variety of neurological disorders in humans. Physical mutagens comprise ionizing and non-ionizing radiation, such as UV rays, IR rays, X-rays, which produces a broad spectrum of neuronal destruction, including neuroinflammation, genetic instability, enhanced oxidative stress driving mitochondrial damage in the human neuronal antecedent cells, cognitive impairment due to alterations in neuronal function, especially in synaptic plasticity, neurogenesis repression, modifications in mature neuronal networks drives to enhanced neurodegenerative risk. Chemical Mutagens including alkylating agents (EMS, NM, MMS, and NTG), Hydroxylamine, nitrous acid, sodium azide, halouracils are the major toxic mutagen in our environment and have been associated with neurological disorders. These chemical mutagens create dimers of pyrimidine that cause DNA damage that leads to ROS generation producing mutations, chromosomal abnormalities, genotoxicity which leads to increased neurodegenerative risk. The toxicity of four heavy metal including Cd, As, Pb, Hg is mostly responsible for complicated neurological disorders in humans. Cadmium exposure can enhance the permeability of the BBB and penetrate the brain, driving brain intracellular accumulation, cellular dysfunction, and cerebral edema. Arsenic exerts its toxic effect by induction of ROS production in neuronal cells. In this review, we summarize the molecular mechanism and mechanistic effects of mutagens in the environment and their role in multiple neurological disorders.

NUPR1 contributes to radiation resistance by maintaining ROS homeostasis via AhR/CYP signal axis in hepatocellular carcinoma

BACKGROUND

Radiotherapy (RT) is one of the major therapeutic approaches to hepatocellular carcinoma (HCC). Ionizing radiation (IR) inducing the generation of reactive oxygen species (ROS) leads to a promising antitumor effect. However, the dysregulation of the redox system often causes radioresistance and impairs the efficacy of RT. Increasing evidence indicates that nuclear protein 1 (NUPR1) plays a critical role in redox reactions. In this study, we aim to explore the role of NUPR1 in maintaining ROS homeostasis and radioresistance in HCC.

METHODS

The radioresistant role of NUPR1 was determined by colony formation assay, comet assay in vitro, and xenograft tumor models in vivo. Probes for ROS, apoptosis assay, and lipid peroxidation assay were used to investigate the functional effect of NUPR1 on ROS homeostasis and oxidative stress. RNA sequencing and co-immunoprecipitation assay were performed to clarify the mechanism of NUPR1 inhibiting the AhR/CYP signal axis. Finally, we analyzed clinical specimens to assess the predictive value of NUPR1 and AhR in the radiotherapeutic efficacy of HCC.

RESULTS

We demonstrated that NUPR1 was upregulated in HCC tissues and verified that NUPR1 increased the radioresistance of HCC in vitro and in vivo. NUPR1 alleviated the generation of ROS and suppressed oxidative stress, including apoptosis and lipid peroxidation by downregulating cytochrome P450 (CYP) upon IR. ROS scavenger N-acetyl-L-cysteine (NAC) and CYP inhibitor alizarin restored the viability of NUPR1-knockdown cells during IR. Mechanistically, the interaction between NUPR1 and aryl hydrocarbon receptor (AhR) promoted the degradation and decreased nuclear translation of AhR via the autophagy-lysosome pathway, followed by being incapable of CYP's transcription. Furthermore, genetically and pharmacologically activating AhR abrogated the radioresistant role of NUPR1. Clinical data suggested that NUPR1 and AhR could serve as novel biomarkers for predicting the radiation response of HCC.

CONCLUSIONS

Our findings revealed the role of NUPR1 in regulating ROS homeostasis and oxidative stress via the AhR/CYP signal axis upon IR. Strategies targeting the NUPR1/AhR/CYP pathway may have important clinical applications for improving the radiotherapeutic efficacy of HCC.

Self-Sustained Regulation or Self-Perpetuating Dysregulation: ROS-dependent HIF-YAP-Notch Signaling as a Double-Edged Sword on Stem Cell Physiology and Tumorigenesis

Organ development, homeostasis, and repair often rely on bidirectional, self-organized cell-niche interactions, through which cells select cell fate, such as stem cell self-renewal and differentiation. The niche contains multiplexed chemical and mechanical factors. How cells interpret niche structural information such as the 3D topology of organs and integrate with multiplexed mechano-chemical signals is an open and active research field. Among all the niche factors, reactive oxygen species (ROS) have recently gained growing interest. Once considered harmful, ROS are now recognized as an important niche factor in the regulation of tissue mechanics and topology through, for example, the HIF-YAP-Notch signaling pathways. These pathways are not only involved in the regulation of stem cell physiology but also associated with inflammation, neurological disorder, aging, tumorigenesis, and the regulation of the immune checkpoint molecule PD-L1. Positive feedback circuits have been identified in the interplay of ROS and HIF-YAP-Notch signaling, leading to the possibility that under aberrant conditions, self-organized, ROS-dependent physiological regulations can be switched to self-perpetuating dysregulation, making ROS a double-edged sword at the interface of stem cell physiology and tumorigenesis. In this review, we discuss the recent findings on how ROS and tissue mechanics affect YAP-HIF-Notch-PD-L1 signaling, hoping that the knowledge can be used to design strategies for stem cell-based and ROS-targeting therapy and tissue engineering.

Anticancer and Neuroprotective Activities of Ethyl Acetate Fractions from Morus macroura Miq. Plant Organs with Ultraperformance Liquid Chromatography-Electrospray Ionization-Tandem Mass Spectrometry Profiling

Column chromatography afforded the isolation of seven secondary metabolites (1-(2,4,6-trihydroxy phenyl)-ethanone-4-O-β-d-glucopyranoside, naringenin-7-O-β-d-glucopyranoside, kaempferol-3-O-α-l-rhamnoside, kaempferol-3-O-β-d-glucopyranoside, quercetin-3-O-β-d-glucopyranoside, quercetin-3-O-β-d-galactopyranoside, rutin) from the ethyl acetate (ET) fractions of Morus macroura Miq. stems (S), leaves (L), and fruits (F). Their identification based on ultraviolet (UV), electron ionization (EI), electrospray ionization-mass spectrometry (ESI-MS), and 1D and 2D NMR data. In addition, profiling of ET fractions using ultraperformance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) resulted in the identification of 82 compounds belonging to different classes, mainly polyphenolic constituents. Chemical profiling as well as molecular docking directed us to biological evaluation. Interestingly, the ET-L fraction exhibited a robust cytotoxic activity against HepG-2, MCF-7, and HELA cell lines. Also, it displayed a neuromodulatory activity against cisplatin neurotoxicity in rats by ameliorating the neurobehavioral dysfunction visualized in the open field and Y-maze test and modulating the neurochemical parameters such as brain amino acid levels (glutamate, aspartate, serine, and histidine), oxidative stress markers (GSH, MDA, and 8-hydroxy-2'-deoxyguanosine), and purinergic cell energy (adenosine triphosphate (ATP) and adenosine monophosphate (AMP)). In conclusion, the isolated compounds (kaempferol-3-O-β-glucoside and quercetin-3-O-β-glucoside) from the ET-L fraction could serve as potent anticancer agents due to their strong antioxidant, in vitro cytotoxicity, and in vivo neuroprotective activity.

Celecoxib Blocks Vasculogenic Mimicry via an Off-Target Effect to Radiosensitize Lung Cancer Cells: An Experimental Study

The resistance to radiotherapy in lung cancer can be attributed to vasculogenic mimicry (VM) to some extent. Celecoxib (CXB), a selective inhibitor of cyclooxygenase-2 (COX-2), is reported as a radiosensitizer in non-small cell lung cancer (NSCLC). However, whether CXB can regulate VM formation via an off-target effect to radiosensitize NSCLC remains unclear. This study aimed to elucidate the mechanism underlying the radiosensitizing effect of CXB on NSCLC, i.e., whether CXB can inhibit VM formation via binding to newly identified targets other than COX-2. CXB radiosensitivity assay was performed in BALB/c mice bearing H460 xenografts and C57 mice bearing Lewis lung cancer (LLC) xenografts, which were divided into the control, CXB, irradiation (IR) treatment, and IR plus CXB groups. VM formation was observed using 3D Matrigel, periodic acid solution (PAS) staining, and immunofluorescence staining. The potential off-targets of CXB were screened using Protein Data Bank (PDB) database, MGLTools 1.5.6, and AutoDock Vina 1.1.2 and confirmed by Western blotting, enzyme activity assay, and RNA interference in vitro experiments and by immunohistochemistry in vivo experiments. CXB treatment almost eliminated the enhancement of VM formation by IR in vitro and in vivo, partially due to COX-2 inhibition. Four potential off-targets were predicted by molecular docking. Among them, aminopeptidase N (APN) and integrin alpha-V (ITAV) were remarkably inhibited in protein expression and enzyme activity in vitro or in vivo, consistent with the remarkable reduction of VM formation in H460 xenografts in BALB/c mice. In conclusion, CXB dramatically blocked VM through inhibiting newly identified off-targets APN and ITAV, other than COX-2, then radiosensitizing NSCLC.

BEX1 and BEX4 Induce GBM Progression through Regulation of Actin Polymerization and Activation of YAP/TAZ Signaling

GBM is a high-grade cancer that originates from glial cells and has a poor prognosis. Although a combination of surgery, radiotherapy, and chemotherapy is prescribed to patients, GBM is highly resistant to therapies, and surviving cells show increased aggressiveness. In this study, we investigated the molecular mechanism underlying GBM progression after radiotherapy by establishing a GBM orthotopic xenograft mouse model. Based on transcriptomic analysis, we found that the expression of BEX1 and BEX4 was upregulated in GBM cells surviving radiotherapy. We also found that upregulated expression of BEX1 and BEX4 was involved in the formation of the filamentous cytoskeleton and altered mechanotransduction, which resulted in the activation of the YAP/TAZ signaling pathway. BEX1- and BEX4-mediated YAP/TAZ activation enhanced the tumor formation, growth, and radioresistance of GBM cells. Additionally, latrunculin B inhibited GBM progression after radiotherapy by suppressing actin polymerization in an orthotopic xenograft mouse model. Taken together, we suggest the involvement of cytoskeleton formation in radiation-induced GBM progression and latrunculin B as a GBM radiosensitizer.

Downregulated CLIP3 induces radioresistance by enhancing stemness and glycolytic flux in glioblastoma

Background

Glioblastoma Multiforme (GBM) is a malignant primary brain tumor in which the standard treatment, ionizing radiation (IR), achieves a median survival of about 15 months. GBM harbors glioblastoma stem-like cells (GSCs), which play a crucial role in therapeutic resistance and recurrence.

Methods

Patient-derived GSCs, GBM cell lines, intracranial GBM xenografts, and GBM sections were used to measure mRNA and protein expression and determine the related molecular mechanisms by qRT-PCR, immunoblot, immunoprecipitation, immunofluorescence, OCR, ECAR, live-cell imaging, and immunohistochemistry. Orthotopic GBM xenograft models were applied to investigate tumor inhibitory effects of glimepiride combined with radiotherapy.

Results

We report that GSCs that survive standard treatment radiation upregulate Speedy/RINGO cell cycle regulator family member A (Spy1) and downregulate CAP-Gly domain containing linker protein 3 (CLIP3, also known as CLIPR-59). We discovered that Spy1 activation and CLIP3 inhibition coordinately shift GBM cell glucose metabolism to favor glycolysis via two cellular processes: transcriptional regulation of CLIP3 and facilitating Glucose transporter 3 (GLUT3) trafficking to cellular membranes in GBM cells. Importantly, in combination with IR, glimepiride, an FDA-approved medication used to treat type 2 diabetes mellitus, disrupts GSCs maintenance and suppresses glycolytic activity by restoring CLIP3 function. In addition, combining radiotherapy and glimepiride significantly reduced GBM growth and improved survival in a GBM orthotopic xenograft mouse model.

Conclusions

Our data suggest that radioresistant GBM cells exhibit enhanced stemness and glycolytic activity mediated by the Spy1-CLIP3 axis. Thus, glimepiride could be an attractive strategy for overcoming radioresistance and recurrence by rescuing CLIP3 expression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02077-4.

Modulation of serine/threonine-protein phosphatase 1 (PP1) complexes: A promising approach in cancer treatment

Cancer is the second leading cause of death worldwide. Despite the availability of numerous therapeutic options, tumor heterogeneity and chemoresistance have limited the success of these treatments, and the development of effective anticancer therapies remains a major focus in oncology research. The serine/threonine-protein phosphatase 1 (PP1) and its complexes have been recognized as potential drug targets. Research on the modulation of PP1 complexes is currently at an early stage, but has immense potential. Chemically diverse compounds have been developed to disrupt or stabilize different PP1 complexes in various cancer types, with the objective of inhibiting disease progression. Beneficial results obtained in vitro now require further pre-clinical and clinical validation. In conclusion, the modulation of PP1 complexes seems to be a promising, albeit challenging, therapeutic strategy for cancer.

Genome-wide CRISPR/Cas9 screening identifies CARHSP1 responsible for radiation resistance in glioblastoma

Glioblastomas (GBM) is the most common primary malignant brain tumor, and radiotherapy plays a critical role in its therapeutic management. Unfortunately, the development of radioresistance is universal. Here, we identified calcium-regulated heat-stable protein 1 (CARHSP1) as a critical driver for radioresistance utilizing genome-wide CRISPR activation screening. This is a protein with a cold-shock domain (CSD)-containing that is highly similar to cold-shock proteins. CARHSP1 mRNA level was upregulated in irradiation-resistant GBM cells and knockdown of CARHSP1 sensitized GBM cells to radiotherapy. The high expression of CARHSP1 upon radiation might mediate radioresistance by activating the inflammatory signaling pathway. More importantly, patients with high levels of CARHSP1 had poorer survival when treated with radiotherapy. Collectively, our findings suggested that targeting the CARHSP1/TNF-α inflammatory signaling activation induced by radiotherapy might directly affect radioresistance and present an attractive therapeutic target for GBM, particularly for patients with high levels of CARHSP1.

Combined Radiochemotherapy: Metalloproteinases Revisited

Besides cytotoxic DNA damage irradiation of tumor cells triggers multiple intra- and intercellular signaling processes, that are part of a multilayered, treatment-induced stress response at the unicellular and tumor pathophysiological level. These processes are intertwined with intrinsic and acquired resistance mechanisms to the toxic effects of ionizing radiation and thereby co-determine the tumor response to radiotherapy. Proteolysis of structural elements and bioactive signaling moieties represents a major class of posttranslational modifications regulating intra- and intercellular communication. Plasma membrane-located and secreted metalloproteinases comprise a family of metal-, usually zinc-, dependent endopeptidases and sheddases with a broad variety of substrates including components of the extracellular matrix, cyto- and chemokines, growth and pro-angiogenic factors. Thereby, metalloproteinases play an important role in matrix remodeling and auto- and paracrine intercellular communication regulating tumor growth, angiogenesis, immune cell infiltration, tumor cell dissemination, and subsequently the response to cancer treatment. While metalloproteinases have long been identified as promising target structures for anti-cancer agents, previous pharmaceutical approaches mostly failed due to unwanted side effects related to the structural similarities among the multiple family members. Nevertheless, targeting of metalloproteinases still represents an interesting rationale alone and in combination with other treatment modalities. Here, we will give an overview on the role of metalloproteinases in the irradiated tumor microenvironment and discuss the therapeutic potential of using more specific metalloproteinase inhibitors in combination with radiotherapy.

Proteomic signatures of radioresistance: Alteration of inflammation, angiogenesis and metabolism-related factors in radioresistant oesophageal adenocarcinoma

The clinical management of locally advanced oesophageal adenocarcinoma (OAC) involves neoadjuvant chemoradiotherapy (CRT), but as radioresistance remains a major clinical challenge, complete pathological response to CRT only occurs in 20-30% of patients. In this study we used an established isogenic cell line model of radioresistant OAC to detect proteomic signatures of radioresistance to identify novel molecular and cellular targets of radioresistance in OAC. A total of 5785 proteins were identified of which 251 were significantly modulated in OE33R cells, when compared to OE33P. Gene ontology and pathway analysis of these significantly modulated proteins demonstrated altered metabolism in radioresistant cells accompanied by an inhibition of apoptosis. In addition, inflammatory and angiogenic pathways were positively regulated in radioresistant cells compared to the radiosensitive cells. In this study, we demonstrate, for the first time, a comprehensive proteomic profile of the established isogenic cell line model of radioresistant OAC. This analysis provides insights into the molecular and cellular pathways which regulate radioresistance in OAC. Furthermore, it identifies pathway specific signatures of radioresistance that will direct studies on the development of targeted therapies and personalised approaches to radiotherapy.

Overcoming Radiation Resistance by Iron-Platinum Metal Alloy Nanoparticles in Human Copper Transport 1-Overexpressing Cancer Cells via Mitochondrial Disturbance

BACKGROUND

Radiation therapy remains an important treatment modality in cancer therapy, however, resistance is a major problem for treatment failure. Elevated expression of glutathione is known to associate with radiation resistance. We used glutathione overexpressing small cell lung cancer cell lines, SR3A-13 and SR3A-14, established by transfection with γ-glutamylcysteine synthetase (γ-GCS) cDNA, as a model for investigating strategies of overcoming radiation resistance. These radiation-resistant cells exhibit upregulated human copper transporter 1 (hCtr1), which also transports cisplatin. This study was initiated to investigate the effect and the underlying mechanism of iron-platinum nanoparticles (FePt NPs) on radiation sensitization in cancer cells.

MATERIALS AND METHODS

Uptakes of FePt NPs in these cells were studied by plasma optical emission spectrometry and transmission electron microscopy. Effects of the combination of FePt NPs and ionizing radiation were investigated by colony formation assay and animal experiment. Intracellular reactive oxygen species (ROS) were assessed by using fluorescent probes and imaged by a fluorescence-activated-cell-sorting caliber flow cytometer. Oxygen consumption rate (OCR) in mitochondria after FePt NP and IR treatment was investigated by a Seahorse XF24 cell energy metabolism analyzer.

RESULTS

These hCtr1-overexpressing cells exhibited elevated resistance to IR and the resistance could be overcome by FePt NPs via enhanced uptake of FePt NPs. Overexpression of hCtr1 was responsible for the increased uptake/transport of FePt NPs as demonstrated by using hCtr1-transfected parental SR3A (SR3A-hCtr1-WT) cells. Increased ROS and drastic mitochondrial damages with substantial reduction of oxygen consumption rate were observed in FePt NPs and IR-treated cells, indicating that structural and functional insults of mitochondria are the lethal mechanism of FePt NPs. Furthermore, FePt NPs also increased the efficacy of radiotherapy in mice bearing SR3A-hCtr1-WT-xenograft tumors.

CONCLUSION

These results suggest that FePt NPs can potentially be a novel strategy to improve radiotherapeutic efficacy in hCtr1-overexpressing cancer cells via enhanced uptake and mitochondria targeting.

Radioprotective Effect of Flavonoids on Ionizing Radiation-Induced Brain Damage

Patients receiving brain radiotherapy may suffer acute or chronic side effects. Ionizing radiation induces the production of intracellular reactive oxygen species and pro-inflammatory cytokines in the central nervous system, leading to brain damage. Complementary Chinese herbal medicine therapy may reduce radiotherapy-induced side effects. Flavonoids are a class of natural products which can be extracted from Chinese herbal medicine and have been shown to have neuroprotective and radioprotective properties. Flavonoids are effective antioxidants and can also inhibit regulatory enzymes or transcription factors important for controlling inflammatory mediators, affect oxidative stress through interaction with DNA and enhance genomic stability. In this paper, radiation-induced brain damage and the relevant molecular mechanism were summarized. The radio-neuro-protective effect of flavonoids, i.e., antioxidant, anti-inflammatory and maintaining genomic stability, were then reviewed. We concluded that flavonoids treatment may be a promising complementary therapy to prevent radiotherapy-induced brain pathophysiological changes and cognitive impairment.

Celecoxib and Afatinib synergistic enhance radiotherapy sensitivity on human non-small cell lung cancer A549 cells

PURPOSE

Radioresistance is highly correlated with radiotherapy failure in clinical cancer treatment. In the current study, we sought to examine the efficacy of Celecoxib and Afatinib co-treatment as radiosensitizers in the management of non-small cell lung cancer (NSCLC) A549 cells.

MATERIALS AND METHODS

Generally, A549 cells were cultured with the treatment of Celecoxib and/or Afatinib for 24 h. Then, the cells were exposed to irradiation at 2 Gy/min for 1 min. After the end of treatment, cell viability, clonogenic survival, apoptosis and Prostaglandin E2 (PGE2) Elisa assays were performed. Transcriptional levels of Cyclooxygenase-2 (COX-2) affected by Celecoxib and/or Afatinib were measured by RT-qPCR. Posttranscriptional level of epidermal growth factor receptor (EGFR)-related gene was measured by Western blotting analysis.

RESULTS

Here, we, for the first time, reported that the co-treatment of Celecoxib and Afatinib regulates the resistance of NSCLC A549 cells to radiation. The co-treatment of Celecoxib and Afatinib sensitized radiotherapy through the radiation-induced loss of cell viability and colony formation, as well as apoptosis. Mechanistically, Celecoxib and Afatinib-treated cells showed the inhibition of COX-2 and EGFR expression, which may be responsible for the A549 cells' increased resistance to radiation.

CONCLUSION

Our results suggested that Celecoxib and Afatinib regulate cell sensitivity to apoptosis, and thus modulate the resistance of NSCLC to radiation.

Protein phosphatase 1 in tumorigenesis: is it worth a closer look?

Cancer cells take advantage of signaling cascades to meet their requirements for sustained growth and survival. Cell signaling is tightly controlled by reversible protein phosphorylation mechanisms, which require the counterbalanced action of protein kinases and protein phosphatases. Imbalances on this system are associated with cancer development and progression. Protein phosphatase 1 (PP1) is one of the most relevant protein phosphatases in eukaryotic cells. Despite the widely recognized involvement of PP1 in key biological processes, both in health and disease, its relevance in cancer has been largely neglected. Here, we provide compelling evidence that support major roles for PP1 in tumorigenesis.

Targeting hallmarks of cancer to enhance radiosensitivity in gastrointestinal cancers

Radiotherapy is used in the treatment of approximately 50% of all malignancies including gastrointestinal cancers. Radiation can be given prior to surgery (neoadjuvant radiotherapy) to shrink the tumour or after surgery to kill any remaining cancer cells. Radiotherapy aims to maximize damage to cancer cells, while minimizing damage to healthy cells. However, only 10-30% of patients with rectal cancer or oesophageal cancer have a pathological complete response to neoadjuvant chemoradiation therapy, with the rest suffering the negative consequences of toxicities and delays to surgery with no clinical benefit. Furthermore, in pancreatic cancer, neoadjuvant chemoradiation therapy results in a pathological complete response in only 4% of patients and a partial pathological response in only 31%. Resistance to radiation therapy is polymodal and associated with a number of biological alterations both within the tumour itself and in the surrounding microenvironment including the following: altered cell cycle; repopulation by cancer stem cells; hypoxia; altered management of oxidative stress; evasion of apoptosis; altered DNA damage response and enhanced DNA repair; inflammation; and altered mitochondrial function and cellular energetics. Radiosensitizers are needed to improve treatment response to radiation, which will directly influence patient outcomes in gastrointestinal cancers. This article reviews the literature to identify strategies - including DNA-targeting agents, antimetabolic agents, antiangiogenics and novel immunotherapies - being used to enhance radiosensitivity in gastrointestinal cancers according to the hallmarks of cancer. Evidence from radiosensitizers from in vitro and in vivo models is documented and the action of radiosensitizers through clinical trial data is assessed.

Exosomes carrying ALDOA and ALDH3A1 from irradiated lung cancer cells enhance migration and invasion of recipients by accelerating glycolysis

Lung cancer has been recognized as the leading cause of cancer-related death worldwide. Despite the improvements of treatment, the distant metastasis and recurrence of lung cancer caused by therapy resistance is the biggest challenge in clinical management. Extracellular vesicles named exosomes play crucial roles in intercellular communication as signaling mediators and are involved in tumor development. In this study, we isolated exosomes from irradiated lung cancer cells and co-cultured the exosomes with other lung cancer cells. It was found that cellular growth and motility of recipient cells were facilitated. High-throughput LC-MS/MS assay of exosomal proteins and Gene Ontology enrichment analyses indicated that the metabolic enzymes ALDOA and ALDH3A1 had potential contribution in exosome-enhanced motility of recipient cells, and clinical survival analysis demonstrated the close correlations between ALDOA or ALDH3A1 expression and poor prognosis of lung cancer patients. After co-culturing with exosomes derived from irradiated cancer cells, the expressions of these metabolic enzymes were elevated and the glycolytic activity was promoted in recipient cancer cells. In conclusion, our data suggested that exosomes from irradiated lung cancer cells regulated the motility of recipient cells by accelerating glycolytic process, where exosomal ALDOA and ALDH3A1 proteins were important signaling factors.

Cellular Stress Responses in Radiotherapy

Radiotherapy is one of the major cancer treatment strategies. Exposure to penetrating radiation causes cellular stress, directly or indirectly, due to the generation of reactive oxygen species, DNA damage, and subcellular organelle damage and autophagy. These radiation-induced damage responses cooperatively contribute to cancer cell death, but paradoxically, radiotherapy also causes the activation of damage-repair and survival signaling to alleviate radiation-induced cytotoxic effects in a small percentage of cancer cells, and these activations are responsible for tumor radio-resistance. The present study describes the molecular mechanisms responsible for radiation-induced cellular stress response and radioresistance, and the therapeutic approaches used to overcome radioresistance.

TFAP2C increases cell proliferation by downregulating GADD45B and PMAIP1 in non-small cell lung cancer cells

Background

Non-small cell lung cancer (NSCLC) is one of the leading causes of death in the world. NSCLC diagnosed at an early stage can be highly curable with a positive prognosis, but biomarker limitations make it difficult to diagnose lung cancer at an early stage. To identify biomarkers for lung cancer development, we previously focused on the oncogenic roles of transcription factor TFAP2C in lung cancers and revealed the molecular mechanism of several oncogenes in lung tumorigenesis based on TFAP2C-related microarray analysis.

Results

In this study, we analyzed microarray data to identify tumor suppressor genes and nine genes downregulated by TFAP2C were screened. Among the nine genes, we focused on growth arrest and DNA-damage-inducible beta (GADD45B) and phorbol-12-myristate-13-acetate-induced protein 1 (PMAIP1) as representative TFAP2C-regulated tumor suppressor genes. It was observed that overexpressed TFAP2C resulted in inhibition of GADD45B and PMAIP1 expressions at both the mRNA and protein levels in NSCLC cells. In addition, downregulation of GADD45B and PMAIP1 by TFAP2C promoted cell proliferation and cell motility, which are closely associated with NSCLC tumorigenesis.

Conclusion

This study indicates that GADD45B and PMAIP1 could be promising tumor suppressors for NSCLC and might be useful as prognostic markers for use in NSCLC therapy.

Electronic supplementary material

The online version of this article (10.1186/s40659-019-0244-5) contains supplementary material, which is available to authorized users.

LDR-Induced miR-30a and miR-30b Target the PAI-1 Pathway to Control Adverse Effects of NSCLC Radiotherapy

Radiotherapy has been a central part in curing non-small cell lung cancer (NSCLC). However, it is possible that not all of the tumor cells are destroyed by radiation; therefore, it is important to effectively control residual tumor cells that could become aggressive and resistant to radiotherapy. In this study, we aimed to investigate the molecular mechanism of decreased NSCLC radioresistance by low-dose radiation (LDR) pretreatment. The results indicated that miR-30a and miR-30b, which effectively inhibited plasminogen activator inhibitor-1 (PAI-1), were overexpressed by treatment of LDR to NSCLC cells. Phosphorylation of Akt and ERK, the downstream survival signals of PAI-1, was decreased by PAI-1 inhibition. Reduced cell survival and epithelial-mesenchymal transition by PAI-1 inhibition were confirmed in NSCLC cells. Moreover, in vivo orthotopic xenograft mouse models with 7C1 nanoparticles to deliver miRNAs showed that tumor growth and aggressiveness were efficiently decreased by LDR treatment followed by radiotherapy. Taken together, the present study suggested that PAI-1, whose expression is regulated by LDR, was critical for controlling surviving tumor cells after radiotherapy.

Regulation of neuronal development and function by ROS

Reactive oxygen species (ROS) have long been studied as destructive agents in the context of nervous system ageing, disease and degeneration. Their roles as signalling molecules under normal physiological conditions is less well understood. Recent studies have provided ample evidence of ROS-regulating neuronal development and function, from the establishment of neuronal polarity to growth cone pathfinding; from the regulation of connectivity and synaptic transmission to the tuning of neuronal networks. Appreciation of the varied processes that are subject to regulation by ROS might help us understand how changes in ROS metabolism and buffering could progressively impact on neuronal networks with age and disease.

Plasminogen activator inhibitor-1 enhances radioresistance and aggressiveness of non-small cell lung cancer cells

Acquired resistance of tumor cells during treatment limits the clinical efficacy of radiotherapy. Recent studies to investigate acquired resistance under treatment have focused on intercellular communication because it promotes survival and aggressiveness of tumor cells, causing therapy failure and tumor relapse. Accordingly, a better understanding of the functional communication between subpopulations of cells within a tumor is essential to development of effective cancer treatment strategies. Here, we found that conditioned media (CM) from radioresistant non-small cell lung cancer (NSCLC) cells increased survival of radiosensitive cells. Comparative proteomics analysis revealed plasminogen activator inhibitor-1 (PAI-1) as a key molecule in the secretome that acts as an extracellular signaling trigger to strengthen resistance to radiation. Our results revealed that expression and secretion of PAI-1 in radioresistant cells was increased by radiation-induced transcription factors, including p53, HIF-1α, and Smad3. When CM from radioresistant cells was applied to radiosensitive cells, extracellular PAI-1 activated the AKT and ERK1/2 signaling pathway and inhibited caspase-3 activity. Our study also proposed that PAI-1 activates the signaling pathway in radiosensitive cells via extracellular interaction with its binding partners, not clathrin-mediated endocytosis. Furthermore, secreted PAI-1 increased cell migration capacity and expression of EMT markers in vitro and in vivo. Taken together, our findings demonstrate that PAI-1 secreted from radioresistant NSCLC cells reduced radiosensitivity of nearby cells in a paracrine manner, indicating that functional inhibition of PAI-1 signaling has therapeutic potential because it prevents sensitive cells from acquiring radioresistance.

RNF138-mediated ubiquitination of rpS3 is required for resistance of glioblastoma cells to radiation-induced apoptosis

An interaction between ribosomal protein S3 (rpS3) and nuclear factor kappa B or macrophage migration inhibitory factor in non-small-cell lung cancer is responsible for radioresistance. However, the role of rpS3 in glioblastoma (GBM) has not been investigated to date. Here we found that in irradiated GBM cells, rpS3 translocated into the nucleus and was subsequently ubiquitinated by ring finger protein 138 (RNF138). Ubiquitin-dependent degradation of rpS3 consequently led to radioresistance in GBM cells. To elucidate the apoptotic role of rpS3, we analyzed the interactome of rpS3 in ΔRNF138 GBM cells. Nuclear rpS3 interacted with DNA damage inducible transcript 3 (DDIT3), leading to DDIT3-induced apoptosis in irradiated ΔRNF138 GBM cells. These results were confirmed using in vivo orthotopic xenograft models and GBM patient tissues. This study aims to clarify the role of RNF138 in GBM cells and demonstrate that rpS3 may be a promising substrate of RNF138 for the induction of GBM radioresistance, indicating RNF138 as a potential target for GBM therapy.

A Novel Bromophenol Derivative BOS-102 Induces Cell Cycle Arrest and Apoptosis in Human A549 Lung Cancer Cells via ROS-Mediated PI3K/Akt and the MAPK Signaling Pathway

Bromophenol is a type of natural marine product. It has excellent biological activities, especially anticancer activities. In our study of searching for potent anticancer drugs, a novel bromophenol derivative containing indolin-2-one moiety, 3-(4-(3-([1,4'-bipiperidin]-1'-yl)propoxy)-3-bromo-5-methoxybenzylidene)-N-(4-bromophenyl)-2-oxoindoline-5-sulfonamide (BOS-102) was synthesized, which showed excellent anticancer activities on human lung cancer cell lines. A study of the mechanisms indicated that BOS-102 could significantly block cell proliferation in human A549 lung cancer cells and effectively induce G0/G1 cell cycle arrest via targeting cyclin D1 and cyclin-dependent kinase 4 (CDK4). BOS-102 could also induce apoptosis, including activating caspase-3 and poly (ADP-ribose) polymerase (PARP), increasing the Bax/Bcl-2 ratio, enhancing reactive oxygen species (ROS) generation, decreasing mitochondrial membrane potential (MMP, ΔΨm), and leading cytochrome c release from mitochondria. Further research revealed that BOS-102 deactivated the PI3K/Akt pathway and activated the mitogen-activated protein kinase (MAPK) signaling pathway resulting in apoptosis and cell cycle arrest, which indicated that BOS-102 has the potential to develop into an anticancer drug.

Cell death pathways of particulate matter toxicity

Humans are exposed to various complex mixtures of particulate matter (PM) from different sources. Long-term exposure to high levels of these particulates has been linked to a diverse range of respiratory and cardiovascular diseases that have resulted in hospital admission. The evaluation of the effects of PM exposure on the mechanisms related to cell death has been a challenge for many researchers. Therefore, in this review, we have discussed the effects of airborne PM exposure on mechanisms related to cell death. For this purpose, we have compiled literature data on PM sources, the effects of exposure, and the assays and models used for evaluation, in order to establish comparisons between various studies. The analysis of this collected data suggested divergent responses to PM exposure that resulted in different cell death types (apoptosis, autophagy, and necrosis). In addition, PM induced oxidative stress within cells, which appeared to be an important factor in the determination of cell fate. When the levels of reactive oxygen species were overpowering, the cellular fate was directed toward cell death. This may be the underlying mechanism of the development or exacerbation of respiratory diseases, such as emphysema and chronic obstructive pulmonary diseases. In addition, PM was shown to cause DNA damage and the resulting mutations increased the risk of cancer. Furthermore, several conditions should be considered in the assessment of cell death in PM-exposed models, including the cell culture line, PM composition, and the interaction of the different cells types in in vivo models.

miR-668 enhances the radioresistance of human breast cancer cell by targeting IκBα

BACKGROUND

A large proportion of breast cancer patients are resistant to radiotherapy, which is a mainstay treatment for this malignancy, but the mechanisms of radioresistance remain unclear.

METHODS AND MATERIALS

To evaluate the role of miRNAs in radioresistance, we established two radioresistant breast cancer cell lines MCF-7R and T-47DR derived from parental MCF-7 and T-47D. Moreover, miRNA microarray, quantitative RT-PCR analysis, luciferase reporter assay and western blotting were used.

RESULTS

We found that miR-668 was most abundantly expressed in radioresistant cells MCF-7R and T-47DR. miR-668 knockdown reversed radioresistance of MCF-7R and T-47DR, miR-668 overexpression enhanced radioresistance of MCF-7 and T-47D cells. Mechanically, bioinformatics analysis combined with experimental analysis demonstrated IκBα, a tumor-suppressor as well as an NF-κB inhibitor, was a direct target of miR-668. Further, miR-668 overexpression inhibited IκBα expression, activated NF-κB, thus, increased radioresistance of MCF-7 and T-47D cells. Conversely, miR-668 knockdown restored IκBα expression, suppressed NF-κB, increased radiosensitivity of MCF-7R and T-47DR cells.

CONCLUSION

Our findings suggest miR-668 is involved in the radioresistance of breast cancer cells and miR-668-IκBα-NF-κB axis may be a novel candidate for developing rational therapeutic strategies for human breast cancer treatment.

TRAF4 promotes lung cancer aggressiveness by modulating tumor microenvironment in normal fibroblasts

Normal fibroblasts surrounding tumor cells play a crucial role in cancer progression through formation of the tumor microenvironment. Because factors secreted from normal fibroblasts can modulate the tumor microenvironment, it is necessary to identify key factors associated with regulation of secreted factors and to investigate the molecular mechanisms contributing to the tumor microenvironment formation process. In this study, we found that radiation induced the expression and K63-linkage poly-ubiquitination of TRAF4 in normal lung fibroblasts. The K63-linkage poly-ubiquitinated TRAF4 formed complexes with NOX2 or NOX4 by mediating phosphorylated p47-phox in normal lung fibroblasts. Moreover, we showed that TRAF4 stabilized NOX complexes by decreasing lysosomal degradation of NOX2 and NOX4 after irradiation. NOX complexes increased endosomal ROS levels that were permeable into cytoplasm, leading to NF-κB-mediated ICAM1 up-regulation. Soluble ICAM1 was subsequently secreted into conditioned media of radiation-activated normal lung fibroblasts. The conditioned media from irradiated normal fibroblasts enhanced proliferation and epithelial-mesenchymal transition of non-small cell lung cancer cells both in vitro and in vivo. These results demonstrate that TRAF4 in irradiated fibroblasts is positively associated with aggressiveness of adjacent cancer cells by altering the tumor microenvironment. Thus, we suggest that regulation of TRAF4 might be a promising strategy for cancer therapy.

[Dexmedetomidine preconditioning protects against lipopolysaccharides-induced injury in the human alveolar epithelial cells]

BACKGROUND AND OBJECTIVES

Dexmedetomidine (DEX) has demonstrated the preconditioning effect and shown protective effects against organize injury. In this study, using A549 (human alveolar epithelial cell) cell lines, we investigated whether DEX preconditioning protected against acute lung injury (ALI) in vitro.

METHODS

A549 were randomly divided into four groups (n=5): control group, DEX group, lipopolysaccharides (LPS) group, and D-LPS (DEX+LPS) group. Phosphate buffer saline (PBS) or DEX were administered. After 2h preconditioning, the medium was refreshed and the cells were challenged with LPS for 24h on the LPS and D-LPS group. Then the malondialdehyde (MDA), superoxide dismutase (SOD), Bcl-2, Bax, caspase-3 and the cytochrome c in the A549 were tested. The apoptosis was also evaluated in the cells.

RESULTS

Compare with LPS group, DEX preconditioning reduced the apoptosis (26.43%±1.05% vs. 33.58%±1.16%, p<0.05) in the A549, which is correlated with decreased MDA (12.84±1.05 vs. 19.16±1.89nmol.mg^-1 protein, p<0.05) and increased SOD activity (30.28±2.38 vs. 20.86±2.19U.mg^-1 protein, p<0.05). DEX preconditioning also increased the Bcl-2 level (0.53±0.03 vs. 0.32±0.04, p<0.05) and decreased the level of Bax (0.49±0.04 vs. 0.65±0.04, p<0.05), caspase-3 (0.54±0.04 vs. 0.76±0.04, p<0.05) and cytochrome c.

CONCLUSION

DEX preconditioning has a protective effect against ALI in vitro. The potential mechanisms involved are the inhibition of cell death and improvement of antioxidation.

Phosphatases and solid tumors: focus on glioblastoma initiation, progression and recurrences

Phosphatases and cancer have been related for many years now, as these enzymes regulate key cellular functions, including cell survival, migration, differentiation and proliferation. Dysfunctions or mutations affecting these enzymes have been demonstrated to be key factors for oncogenesis. The aim of this review is to shed light on the role of four different phosphatases (PTEN, PP2A, CDC25 and DUSP1) in five different solid tumors (breast cancer, lung cancer, pancreatic cancer, prostate cancer and ovarian cancer), in order to better understand the most frequent and aggressive primary cancer of the central nervous system, glioblastoma.

TFAP2C-mediated upregulation of TGFBR1 promotes lung tumorigenesis and epithelial-mesenchymal transition

TFAP2C (transcription factor-activating enhancer-binding protein 2C) expression has been positively correlated with poor prognosis in patients with certain types of cancer, but the mechanisms underlying TFAP2C-mediated tumorigenesis in non-small-cell lung cancer (NSCLC) are still unknown. We previously performed a microarray analysis to identify TFAP2C regulation genes, and TGFBR1 (transforming growth factor-β receptor type 1) was found to be upregulated by TFAP2C. We observed that TFAP2C or TGFBR1 overexpression led to oncogenic properties, such as cell viability, proliferation and cell cycle progression. TGFBR1 upregulation induced by TFAP2C also promoted cell motility and migration, leading to malignant development. We also found that PAK1 (p21 protein (Cdc42/Rac)-activated kinase 1) signaling was involved in TFAP2C/TGFBR1-induced tumorigenesis. These results were confirmed by an in vivo xenograft model and patient tissue samples. This study shows that TFAP2C promoted tumor progression by upregulation of TGFBR1 and consequent activation of PAK1 signaling.

Chlorogenic acid prevents isoproterenol-induced DNA damage in vascular smooth muscle cells

Numerous clinical therapeutic agents have been identified as DNA damaging. The present study revealed that isoproterenol (Iso) resulted in DNA damage in vascular smooth muscle cells (VSMCs) and increased the levels of intracellular oxygen free radicals. Administration of chlorogenic acid (CGA) inhibited this effect. Pretreatment with CGA abrogated the increase in protein expression levels of γ-H2A histone family member X, phosphorylated ataxia telangiectasia mutated, phosphorylated Rad3-related protein, breast cancer 1 and C-terminal Src homologous kinase induced by Iso. In addition, the increase in levels of intracellular reactive oxygen species (ROS) induced by Iso was inhibited by CGA pretreatment in a dose-dependent manner. The results of the present study suggest that CGA may inhibit Iso-induced VSMC damage via the suppression of ROS generation. Therefore, CGA may be a novel agent for the treatment of vascular diseases.

Selective internal radiation therapy in treatment of hepatocellular carcinoma: new concepts of personalization

Hepatocellular carcinoma (HCC) is a global health problem, with more than half a million new cases diagnosed annually and mortality rates at similar level. The majority of HCC is diagnosed at intermediate-advanced stages being, therefore, an issue for palliative rather than curative care. Selective internal radiation therapy (SIRT) is one of the best appropriate palliative treatment modalities in HCC management. Although delivering satisfactory results, SIRT application comes along with frequent complications and tumor recurrence. Recent studies suggest treatment algorithm tailored to the person as improving individual outcomes and reducing treatment-related complications. This review provides insights to implicate innovative concepts of predictive, preventive and personalized medicine in SIRT application to HCC cohorts.

Inhibitory effect of traditional oriental medicine-derived monoamine oxidase B inhibitor on radioresistance of non-small cell lung cancer

Increased survival of cancer cells mediated by high levels of ionizing radiation (IR) reduces the effectiveness of radiation therapy for non-small cell lung cancer (NSCLC). In the present study, danshensu which is a selected component of traditional oriental medicine (TOM) compound was found to reduce the radioresistance of NSCLC by inhibiting the nuclear factor-κB (NF-κB) pathway. Of the various TOM compounds reported to inhibit the IR activation of NF-κB, danshensu was chosen as a final candidate based on the results of structural comparisons with human metabolites and monoamine oxidase B (MAOB) was identified as the putative target enzyme. Danshensu decreased the activation of NF-κB by inhibiting MAOB activity in A549 and NCI-H1299 NSCLC cells. Moreover, it suppressed IR-induced epithelial-to-mesenchymal transition, expressions of NF-κB-regulated prosurvival and proinflammatory genes, and in vivo radioresistance of mouse xenograft models. Taken together, this study shows that danshensu significantly reduces MAOB activity and attenuates NF-κB signaling to elicit the radiosensitization of NSCLC.

Downregulation of Nrf2 promotes radiation-induced apoptosis through Nrf2 mediated Notch signaling in non-small cell lung cancer cells

The nuclear factor erythroid-2-related factor 2 (Nrf2) is a crucial regulator of the cellular antioxidant system. Nrf2 is often constitutively activated in non-small cell lung cancer (NSCLC) cell lines, which promotes cytoprotection against oxidative stress and xenobiotics. Notch1 signaling is critically implicated in cell fate determination. It has been reported that Nf2 strongly regulates Notch1 activity. However, the role of Nrf2 mediated Notch1 signaling in response to ionizing radiation (IR) remains elusive. We report that knockdown of Nrf2 promotes radiation-induced apoptosis through Nrf2 mediated Notch1 signaling in NSCLC cells. IR activated Nrf2 in a dose-dependent manner and the expression of Nrf2 was significantly elevated at 4 h after exposure. RNAi-mediated reduction of Nrf2 significantly increased endogenous ROS levels, and decreased the expression of glutamate cysteine ligase catalytic subunit (GCLC), heme oxygenase-1 (HO-1) and NAD (P) H quinine oxidoreductase-1 (NQO1) in irradiated cells. Furthermore, decrease in Nrf2 expression significantly dampened Notch1 expression following ionizing radiation exposure, and potentiated IR-induced cellular apoptosis. These results demonstrated that Nrf2 could be activated by ionizing radiation, knockdown of Nrf2 could promote radiation induced apoptosis and Nrf2-mediated Notch signaling is an important determinant in radioresistance of lung cancer cells.

The relevance of molecular biomarkers in cervical cancer patients treated with radiotherapy

BACKGROUND

Radiotherapy (RT) plays an integral role in the combined-modality management of cervical cancer. Various molecular mechanisms have been implicated in the adaptive cellular response to RT. Identification of these molecular processes may permit the prediction of treatment outcome and enhanced radiation-induced cancer cell killing through tailoring of the management approach, and/or the employment of selective inhibitors of these pathways.

METHODS

PubMed was searched for studies presenting biomarkers of cervical cancer radioresistance validated in patient studies or in laboratory experimentation.

RESULTS

Several biomarkers of cervical cancer radioresistance are validated by patient survival or recurrence data. These biomarkers fall into categories of biological function including hypoxia, cell proliferation, cell-cell adhesion, and evasion of apoptosis. Additional radioresistance biomarkers have been identified in exploratory experiments.

CONCLUSIONS

Biomarkers of radioresistance in cervical cancer may allow molecular profiling of individual tumors, leading to tailored therapies and better prognostication and prediction of outcomes.