Radiation-enhanced hepatocellular carcinoma cell invasion with MMP-9 expression through PI3K/Akt/NF-kappaB signal transduction pathway

Dual effects of radiotherapy on tumor microenvironment and its contribution towards the development of resistance to immunotherapy in gastrointestinal and thoracic cancers

Successful clinical methods for tumor elimination include a combination of surgical resection, radiotherapy, and chemotherapy. Radiotherapy is one of the crucial components of the cancer treatment regimens which allow to extend patient life expectancy. Current cutting-edge radiotherapy research is focused on the identification of methods that should increase cancer cell sensitivity to radiation and activate anti-cancer immunity mechanisms. Radiation treatment activates various cells of the tumor microenvironment (TME) and impacts tumor growth, angiogenesis, and anti-cancer immunity. Radiotherapy was shown to regulate signaling and anti-cancer functions of various TME immune and vasculature cell components, including tumor-associated macrophages, dendritic cells, endothelial cells, cancer-associated fibroblasts (CAFs), natural killers, and other T cell subsets. Dual effects of radiation, including metastasis-promoting effects and activation of oxidative stress, have been detected, suggesting that radiotherapy triggers heterogeneous targets. In this review, we critically discuss the activation of TME and angiogenesis during radiotherapy which is used to strengthen the effects of novel immunotherapy. Intracellular, genetic, and epigenetic mechanisms of signaling and clinical manipulations of immune responses and oxidative stress by radiotherapy are accented. Current findings indicate that radiotherapy should be considered as a supporting instrument for immunotherapy to limit the cancer-promoting effects of TME. To increase cancer-free survival rates, it is recommended to combine personalized radiation therapy methods with TME-targeting drugs, including immune checkpoint inhibitors.

Local Liver Irradiation Concurrently Versus Sequentially with Cabozantinib on the Pharmacokinetics and Biodistribution in Rats

The aim of this study was to evaluate the radiotherapy (RT)-pharmacokinetics (PK) effect of cabozantinib in concurrent or sequential regimens with external beam radiotherapy (EBRT) or stereotactic body radiation therapy (SBRT). Concurrent and sequential regimens involving RT and cabozantinib were designed. The RT–drug interactions of cabozantinib under RT were confirmed in a free-moving rat model. The drugs were separated on an Agilent ZORBAX SB-phenyl column with a mobile phase consisting of 10 mM potassium dihydrogen phosphate (KH2PO4)–methanol solution (27:73, v/v) for cabozantinib. There were no statistically significant differences in the concentration versus time curve of cabozantinib (AUCcabozantinib) between the control group and the RT2Gy×3 f’x and RT9Gy×3 f’x groups in the concurrent and the sequential regimens. However, compared to those in the control group, the Tmax, T1/2 and MRT decreased by 72.8% (p = 0.04), 49.0% (p = 0.04) and 48.5% (p = 0.04) with RT2Gy×3 f’x in the concurrent regimen, respectively. Additionally, the T1/2 and MRT decreased by 58.8% (p = 0.01) and 57.8% (p = 0.01) in the concurrent RT9Gy×3 f’x group when compared with the control group, respectively. The biodistribution of cabozantinib in the heart increased by 271.4% (p = 0.04) and 120.0% (p = 0.04) with RT2Gy×3 f’x in the concurrent and sequential regimens compared to the concurrent regimen, respectively. Additionally, the biodistribution of cabozantinib in the heart increased by 107.1% (p = 0.01) with the RT9Gy×3 f’x sequential regimen. Compared to the RT9Gy×3 f’x concurrent regimen, the RT9Gy×3 f’x sequential regimen increased the biodistribution of cabozantinib in the heart (81.3%, p = 0.02), liver (110.5%, p = 0.02), lung (125%, p = 0.004) and kidneys (87.5%, p = 0.048). No cabozantinib was detected in the brain in any of the groups. The AUC of cabozantinib is not modulated by irradiation and is not affected by treatment strategies. However, the biodistribution of cabozantinib in the heart is modulated by off-target irradiation and SBRT doses simultaneously. The impact of the biodistribution of cabozantinib with RT9Gy×3 f’x is more significant with the sequential regimen than with the concurrent regimen.

Lenvatinib Synergistically Promotes Radiation Therapy in Hepatocellular Carcinoma by Inhibiting Src/STAT3/NF-κB-Mediated Epithelial-Mesenchymal Transition and Metastasis

PURPOSE

This study suggested that lenvatinib may incapacitate hepatocellular carcinoma (HCC) to radiation treatment by abrogating radiation-induced Src/signal transducer and the activator of transcription 3 signaling (STAT3)/nuclear factor-κB (NF-κB) to escalate radiation-induced extrinsic and intrinsic apoptosis. These findings uncover the role of targeting Src and its arbitrating epithelial-mesenchymal transition (EMT), which could increase the anti-HCC efficacy of radiation therapy (RT). Lenvatinib and sorafenib are multikinase inhibitors used to treat HCC. Lenvatinib is noninferior to sorafenib in the therapeutic response in HCC. However, whether lenvatinib intensifies the anti-HCC efficacy of RT is ambiguous. Several oncogenic kinases and transcription factors, such as Src, STAT3, and NF-κB, enhance the radiosensitivity of cancers. Therefore, we aimed to investigate the roles of the Src/STAT3/NF-κB axis in HCC after RT treatment and assessed whether targeting Src by lenvatinib may enhance the effectiveness of RT.

METHODS AND MATERIALS

Hep3B, Huh7, HepG2, and SK-Hep1 HCC cells and 2 types of animal models were used to identify the efficacy of RT combined with lenvatinib. Cellular toxicity, apoptosis, DNA damage, EMT/metastasis regulation, and treatment efficacy were validated by colony formation, flow cytometry, Western blotting, and in vivo experiments, respectively. Knockdown of Src by siRNA was also used to validate the role of Src in RT treatment.

RESULTS

Silencing Src reduced STAT3/NF-κB signaling and sensitized HCC to radiation. Lenvatinib reversed radiation-elicited Src/STAT3/NF-κB signaling while enhancing the anti-HCC efficacy of radiation. Both lenvatinib and siSrc promoted the radiation effect of cell proliferation on suppression, inhibition of the invasion ability, and induction of apoptosis in HCC. Lenvatinib also alleviated radiation-triggered oncogenic and EMT-related protein expression.

CONCLUSIONS

Our findings uncovered the role of the Src/STAT3/NF-κB regulatory axis in response to radiation-induced toxicity and confirmed Src as the key regulatory molecule for radiosensitization of HCC evoked by lenvatinib.

Gold Nanorods Inhibit Tumor Metastasis by Regulating MMP-9 Activity: Implications for Radiotherapy

Dysregulation of matrix metalloproteinase (MMP) is strongly implicated in tumor invasion and metastasis. Nanomaterials can interact with proteins and have impacts on protein activity, which provides a potential strategy for inhibiting tumor invasion and metastasis. However, the regulation of MMP activity by nanomaterials has not been fully determined. Herein, we have found that gold nanorods (Au NRs) are able to induce the change of the secondary structure of MMP-9 and thereby inhibit their activity. Interestingly, the inhibition of MMP-9 activity is highly dependent on the aspect ratio of Au NRs, and an aspect ratio of 3.3 shows the maximum inhibition efficiency. Molecular dynamics simulations combined with mathematical statistics algorithm reveal the binding behaviors and interaction modes of MMP-9 with Au NRs in atomic details and disclose the mechanism of aspect ratio-dependent inhibition effect of Au NRs on MMP-9 activity. Au NRs with an aspect ratio of 3.3 successfully suppress the X-ray-activated invasion and metastasis of tumor by inhibiting MMP-9 activity. Our findings provide important guidance for the modulation of MMP-9 activity by tuning key parameters of nanomaterials and demonstrate that gold nanorods could be developed as potential MMP inhibitors.

Targets Involved in the Anti-Cancer Activity of Quercetin in Breast, Colorectal and Liver Neoplasms

Phytochemicals have long been effective partners in the fight against several diseases, including cancer. Among these, flavonoids are valuable allies for both cancer prevention and therapy since they are known to influence a large panel of tumor-related processes. Particularly, it was revealed that quercetin, one of the most common flavonoids, controls apoptosis and inhibits migration and proliferation, events essential for the development of cancer. In this review, we collected the evidence on the anti-cancer activity of quercetin exploring the network of interactions between this flavonol and the proteins responsible for cancer onset and progression focusing on breast, colorectal and liver cancers, owing to their high worldwide incidence. Moreover, quercetin proved to be also a potentiating agent able to push further the anti-cancer activity of common employed anti-neoplastic agents, thus allowing to lower their dosages and, above all, to sensitize again resistant cancer cells. Finally, novel approaches to delivery systems can enhance quercetin's pharmacokinetics, thus boosting its great potentiality even further. Overall, quercetin has a lot of promise, given its multi-target potentiality; thus, more research is strongly encouraged to properly define its pharmaco-toxicological profile and evaluate its potential for usage in adjuvant and chemoprevention therapy.

Targeting Tumor Physical Microenvironment for Improved Radiotherapy

Radiotherapy has led to important clinical advances; existing cancer radiotherapy resistance is one remaining major challenge. Recently, biophysical cues in the tumor microenvironment (TME) have been regarded as the new hallmarks of cancer, playing pivotal roles in various cancer behaviors and treatment responses, including radiotherapy resistance. With recent advances in micro/nanotechnologies and functional biomaterials, radiotherapy exerts great influence on biophysical cues in TME, which, in turn, significantly affect the response to radiotherapy. Besides, various strategies have emerged that target biophysical cues in TME, to potentially enhance radiotherapy efficacy. Therefore, this paper reviews the four biophysical cues (i.e., extracellular matrix (ECM) microarchitecture, ECM stiffness, interstitial fluid pressure, and solid stress) that may play important roles in radiotherapy resistance, their possible mechanisms for inducing it, and their change after radiotherapy. The emerging therapeutic strategies targeting the biophysical microenvironment, to explore the mechanism of radiotherapy resistance and develop effective strategies to revert it for improved treatment efficacy are further summarized.

KIF20A promotes the development of fibrosarcoma via PI3K-Akt signaling pathway

Adult fibrosarcoma is an aggressive subtype of soft tissue sarcoma (STS), in which high expression of KIF20A indicates a poor prognosis. However, the precise role of KIF20A in fibrosarcoma progression remains unknown. In this study, we initially examined KIF20A expression and function in the human fibrosarcoma cell line HT-1080. The results showed that KIF20A was highly expressed in HT-1080, knockdown of KIF20A impaired cell proliferation, migration, invasion and induced G2/M arrest and cell apoptosis. Transcriptome study suggested that PI3K-Akt signal pathway was involved in these biological changes. We confirmed that PI3K-Akt and NF-κB signaling pathways were impaired after the down-regulation of KIF20A, which can be reversed by the Akt activator SC79 in HT-1080 in vitro. In a xenograft mouse model, knockdown of KIF20A inhibited tumor growth, Ki67 expression and liver metastasis. Taken together, our results suggested that KIF20A promoted fibrosarcoma progression via PI3K-Akt signaling pathway and might be a potential therapeutic target for fibrosarcoma.

Tepotinib suppresses proliferation, invasion, migration, and promotes apoptosis of melanoma cells via inhibiting MET and PI3K/AKT signaling pathways

Malignant melanoma seriously threatens public health and lowers the quality of life of the affected subjects. The present study was designed to explore the effects of tepotinib, a selective tyrosine kinase inhibitor of MET proto-oncogene, receptor tyrosine kinase (MET), on the progression of melanoma. Firstly, MTT assays were used to detect the proliferation of tepotinib-treated WM451 cells. The cell invasive and migratory activities were assessed using Transwell and wound healing assays, respectively. In addition, TUNEL staining was employed to determine cell apoptosis. Western blot analysis was utilized for the evaluation of the expression levels of apoptotic and epithelial-mesenchymal transition-related proteins, as well as of proteins involved in the PI3K/AKT signaling pathway. Subsequently, hepatocyte growth factor (HGF), a natural agonist of MET, was administered to WM451 cells to unravel the detailed mechanism of action of tepotinib in melanoma. The results indicated that the proliferation of WM451 cells was significantly decreased by tepotinib treatment. The inhibitory effects of tepotinib on the proliferation of WM451 cells occurred in a concentration-dependent manner. In addition, the migratory and invasive activities of WM451 cells were significantly suppressed following tepotinib treatment. It was also shown that tepotinib exhibited promotive effects on the induction of apoptosis of WM451 cells. Moreover, activation of MET and PI3K/AKT signaling pathways may be blocked by tepotinib treatment, whereas addition of HGF to the cells reversed the effects of tepotinib treatment on the malignant progression of WM451 cells. In conclusion, the data demonstrated that tepotinib suppressed the proliferation, invasion and migration of melanoma cells, whereas it could also induce their apoptosis. This evidence may provide a new perspective for the improvement of malignant melanoma.

Impact of Irradiation on the Pharmacokinetics and Biotransformation of Tamoxifen

Background

The optimal procedure for combining radiotherapy (RT) with tamoxifen treatment is controversial as RT may alter the pharmacokinetics and biotransformation of tamoxifen. The present study investigated this potential interaction by assessing the pharmacokinetics of tamoxifen during concurrent and sequential RT.

Method

Plasma tamoxifen concentration was measured in rats with or without RT 2.0 Gy (RT2.0Gy) or 0.5 Gy (RT0.5Gy) with ultra-high-performance liquid chromatography-tandem mass spectrometry after tamoxifen administration (10 mg/kg, p.o., n = 6). Tamoxifen was either administered 1 h after RT (concurrent condition) or 24 h after RT (sequential condition).

Results

Pharmacokinetic data analysis demonstrated that the area under the curve (AUC) and half-life of tamoxifen were 2,004 ± 241 h ng/ml and 6.23 ± 1.21 h, respectively, after tamoxifen administration (10 mg/kg, p.o.). The respective conversion rate of 4-hydroxytamoxifen, N-desmethytamoxifen, and endoxifen for tamoxifen metabolism was 20%, 16%, and 5%. The AUC value of tamoxifen in the RT0.5Gy group was 1.5- to 1.7-fold higher than in the sham and RT2.0Gy groups. The relative bioavailability of tamoxifen at concurrent RT0.5Gy and RT2.0Gy groups ranged from 127% to 202% and from 71% to 152%, respectively. The magnitude of endoxifen, which converted from 4-hydroxytamoxifen and N-desmethyltamoxifen, increased 3- to 5-fold in the concurrent RT groups. By contrast, the AUC of tamoxifen decreased by roughly 24% in the sequential RT2.0Gy group. The conversion ratio of endoxifen was four times higher than that in the sequential RT2.0Gy group compared with rats not exposed to RT.

Conclusion

The current study provides advanced pharmacokinetic data to confirm the interaction between RT and hormone therapy. Our findings indicate that RT facilitates the metabolism of tamoxifen to active metabolites and thus imply that combination RT-tamoxifen has potential benefits for the treatment of hormone-dependent breast cancer.

Roles of BMI1 in the Initiation, Progression, and Treatment of Hepatocellular Carcinoma

Liver cancer has high rates of morbidity and mortality, and its treatment is a global health challenge. Hepatocellular carcinoma (HCC) accounts for 90% of all primary liver cancer cases. B-lymphoma Mo-MLV insertion region 1 (BMI1) has been identified as a proto-oncogene, which contributes to the initiation and progression of many malignant tumors. BMI1 expression is upregulated in HCC, and it influences the occurrence and development of HCC by various mechanisms, such as the INK4a/ARF locus, NF-κB signaling pathway, and PTEN/PI3K/AKT signaling pathway. In addition, the expression of BMI1 is related to prognosis and recurrence of HCC. Hence, there is clear evidence that BMI1 is a novel and valid therapeutic target for HCC. Accordingly, the development of therapeutic strategies targeting BMI1 has been a focus of recent research, providing new directions for HCC treatment. This review summarizes the role of BMI1 in the occurrence and treatment of HCC, which will provide a basis for using BMI1 as a potential target for the development of therapeutic strategies for HCC.

Dictamnine, a novel c-Met inhibitor, suppresses the proliferation of lung cancer cells by downregulating the PI3K/AKT/mTOR and MAPK signaling pathways

Dictamnine (Dic), a naturally occurring small-molecule furoquinoline alkaloid isolated from the root bark of Dictamnus dasycarpus Turcz., is reported to display anticancer properties. However, little is known about the direct target proteins and anticancer mechanisms of Dic. In the current study, Dic was found to suppress the growth of lung cancer cells in vitro and in vivo, and to attenuate the activation of PI3K/AKT/mTOR and mitogen-activated protein kinase (MAPK) signaling pathways by inhibiting the phosphorylation and activation of receptor tyrosine kinase c-Met. Moreover, the binding of Dic to c-Met was confirmed by using cellular thermal shift assay (CETSA) and drug affinity responsive target stability (DARTS) assay. Among all cancer cell lines tested, Dic inhibited the proliferation of c-Met-dependent EBC-1 cells with the greatest potency (IC50 = 2.811 μM). Notably, Dic was shown to synergistically improve the chemo-sensitivity of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI)-resistant lung cancer cells to gefitinib and osimertinib. These results suggest that Dic is a c-Met inhibitor that can serve as a potential therapeutic agent in the treatment of lung cancer, especially against EGFR TKI-resistant and c-Met-dependent lung cancer.

Cytoskeleton Response to Ionizing Radiation: A Brief Review on Adhesion and Migration Effects

The cytoskeleton is involved in several biological processes, including adhesion, motility, and intracellular transport. Alterations in the cytoskeletal components (actin filaments, intermediate filaments, and microtubules) are strictly correlated to several diseases, such as cancer. Furthermore, alterations in the cytoskeletal structure can lead to anomalies in cells’ properties and increase their invasiveness. This review aims to analyse several studies which have examined the alteration of the cell cytoskeleton induced by ionizing radiations. In particular, the radiation effects on the actin cytoskeleton, cell adhesion, and migration have been considered to gain a deeper knowledge of the biophysical properties of the cell. In fact, the results found in the analysed works can not only aid in developing new diagnostic tools but also improve the current cancer treatments.

PB01 suppresses radio-resistance by regulating ATR signaling in human non-small-cell lung cancer cells

Despite the common usage of radiotherapy for the treatment of human non-small-cell lung cancer (NSCLC), cancer therapeutic efficacy and outcome with ionizing radiation remains a challenge. Here, we report the antitumor effects and mechanism of a novel benzothiazole derivative PB01 (4-methoxy-cyclohexane carboxylic acid [2-(3,5-dimethyl-isoxazole-4-yl) sulpanil-benzothiazole-6-yl]-amide) in radiation-resistant human NSCLC cells. PB01 treatment is cytotoxic because it induces reactive oxygen species, ER stress, Bax, cytochrome c expression, the ATR-p53-GADD45ɑ axis, and cleavage of caspase-3 and -9. Additionally, we found that radio-resistant A549 and H460 subclones, named A549R and H460R, respectively, show enhanced epithelial-to-mesenchymal transition (EMT), whereas PB01 treatment inhibits EMT and mediates cell death through ER stress and the ATR axis under radiation exposure in radio-resistant A549R and H460R cells. Together, these results suggest that PB01 treatment can overcome radio-resistance during radiotherapy of NSCLC.

Bystander effects induced by electron beam-irradiated MCF-7 cells: a potential mechanism of therapy resistance

PURPOSE

The distinct direct and non-targeting effects of electron beam radiation on MCF-7 cells remain obscure. We aimed to investigate the effect of electron beam irradiation (EBI) and conditioned media (CM) of the irradiated MCF-7 cells on MCF-7 cells. The cytotoxic effects of CM from irradiated MCF-7 cells on the mesenchymal stem cells and human umbilical vein endothelial cells (HUVECs) were also examined.

METHODS

Cell viability and apoptosis were assayed via MTT and flow cytometry analysis, respectively. The production of ROS (reactive oxygen species) was evaluated by the chemical fluorometric method, while the amount of extracellular vesicles was detected via acetylcholinesterase activity assay. Expression of genes involved in apoptosis, including caspase-3, -8, -9, and stemness such as Sox-2 and Oct-4, were calculated through qPCR. The wound healing rate of cells was monitored via in vitro scratch assay.

RESULTS

Compared to the control group, EBI groups showed decreased cell viability but increased apoptosis and ROS as well as acetylcholinesterase activity dose-dependently (P < 0.05). Concurrently with increasing the dose of the electron beam, the transcript levels of apoptotic genes (caspase-3, -8, -9) and stemness-related genes (Sox-2 and Oct-4) were up-regulated following EBI. The wound healing rate of irradiated MCF-7 cells increased dose-dependently (P < 0.05). Similar results were observed after treatment with CM from irradiated MCF-7 cells. Additionally, CM from irradiated MCF-7 cells decreased the viability of MCF-7 cells, mesenchymal stem cells, and HUVECs (P < 0.05).

CONCLUSION

MCF-7 cells treated with an electron beam and CMs from irradiated MCF-7 cells exhibit an up-regulation in both genes involved in the apoptosis pathway and stemness. As a result, EBI can affect apoptosis and stemness in MCF-7 cells in direct and bystander manners. However, specific signaling pathways require careful evaluation to provide an understanding of the mechanisms involved in the EBI-induced alternation in tumor cell dynamics.

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.

Rosmarinic Acid Induces Proliferation Suppression of Hepatoma Cells Associated with NF-κB Signaling Pathway

BACKGROUND

Rosmarinic acid (RA) is a natural phenolic compound that acts as a Fyn inhibitor by 53 homology modeling of the human Fyn structure. Therefore, the apoptosis mechanism related to  NF-κB signaling pathway induced by RA in HepG2 was investigated.

METHODS

The cell growth, apoptosis, and proliferation of HepG2 regulated by various concentrations of RA were studied. The proteins expression of MMP-2, MMP-9, PI3K, AKT, NF-κB, and apoptosis-related proteins Bax, Bcl-2, cleaved caspase-3 were detected.

RESULTS

RA significantly reduced proliferation rates, inhibited migration and invasion, and decreased the expressions of invasion-related factors, such as matrix metalloproteinase (MMP)-2 and MMP-9. TUNEL staining revealed that RA resulted in a dose-dependent increase of HepG2 cell apoptosis. In line with this finding, the expression of apoptosis suppressor protein Bcl-2 was downregulated and that of the pro-apoptotic proteins Bax and cleaved caspase-3 was increased. In addition, we found that the phosphatidylinositol 3-kinase (PI3K)/Akt/nuclear factor kappa B (NF-κB) signaling pathway was involved in RA-mediated inhibition of HepG2 cell metastasis.

CONCLUSION

Our study identified that  RA as a drug candidate for the treatment of HCC.

Mutation-specific non-canonical pathway of PTEN as a distinct therapeutic target for glioblastoma

PTEN is one of the most frequently altered tumor suppressor genes in malignant tumors. The dominant-negative effect of PTEN alteration suggests that the aberrant function of PTEN mutation might be more disastrous than deletion, the most frequent genomic event in glioblastoma (GBM). This study aimed to understand the functional properties of various PTEN missense mutations and to investigate their clinical relevance. The genomic landscape of PTEN alteration was analyzed using the Samsung Medical Center GBM cohort and validated via The Cancer Genome Atlas dataset. Several hotspot mutations were identified, and their subcellular distributions and phenotypes were evaluated. We established a library of cancer cell lines that overexpress these mutant proteins using the U87MG and patient-derived cell models lacking functional PTEN. PTEN mutations were categorized into two major subsets: missense mutations in the phosphatase domain and truncal mutations in the C2 domain. We determined the subcellular compartmentalization of four mutant proteins (H93Y, C124S, R130Q, and R173C) from the former group and found that they had distinct localizations; those associated with invasive phenotypes ('edge mutations') localized to the cell periphery, while the R173C mutant localized to the nucleus. Invasive phenotypes derived from edge substitutions were unaffected by an anti-PI3K/Akt agent but were disrupted by microtubule inhibitors. PTEN mutations exhibit distinct functional properties regarding their subcellular localization. Further, some missense mutations ('edge mutations') in the phosphatase domain caused enhanced invasiveness associated with dysfunctional cytoskeletal assembly, thus suggesting it to be a potent therapeutic target.

Effect of Synchronous Versus Sequential Regimens on the Pharmacokinetics and Biodistribution of Regorafenib with Irradiation

This study was performed to evaluate the interaction between conventional or high-dose radiotherapy (RT) and the pharmacokinetics (PK) of regorafenib in concurrent or sequential regimens for the treatment of hepatocellular carcinoma. Concurrent and sequential in vitro and in vivo studies of irradiation and regorafenib were designed. The interactions of RT and regorafenib in vitro were examined in the human hepatoma Huh-7, HA22T and Hep G2 cell lines. The RT–PK phenomenon and biodistribution of regorafenib under RT were confirmed in a free-moving rat model. Regorafenib inhibited the viability of Huh-7 cells in a dose-dependent manner. Apoptosis in Huh-7 cells was enhanced by RT followed by regorafenib treatment. In the concurrent regimen, RT decreased the area under the concentration versus time curve (AUC)_regorafenib by 74% (p = 0.001) in the RT_{2 Gy × 3 fraction (f’x)} group and by 69% (p = 0.001) in the RT_{9 Gy × 3 f’x} group. The AUC_regorafenib was increased by 182.8% (p = 0.011) in the sequential RT_{2Gy × 1 f’x} group and by 213.2% (p = 0.016) in the sequential RT_{9Gy × 1 f’x} group. Both concurrent regimens, RT_{2Gy × 3 f’x} and RT_{9Gy × 3 f’x}, clearly decreased the biodistribution of regorafenib in the heart, liver, lung, spleen and kidneys, compared to the control (regorafenib _{× 3 d}) group. The concurrent regimens, both RT_{2Gy × 3 f’x} and RT_{9Gy × 3 f’x}, significantly decreased the biodistribution of regorafenib, compared with the control group. The PK of regorafenib can be modulated both by off-target irradiation and stereotactic body radiation therapy (SBRT).

Chemokines as the critical factors during bladder cancer progression: an overview

Bladder cancer (BCa) is one of the most frequent urogenital malignancies which is mainly observed among men. There are various genetic and environmental risk factors associated with BCa progression. Transurethral endoscopic resection and open ablative surgery are the main treatment options for muscle invasive BCa. BCG therapy is also employed following the endoscopic resection to prevent tumor relapse. The tumor microenvironment is the main interaction site of tumor cells and immune system in which the immune cells are recruited via chemokines and chemokine receptors. In present review we summarized the main chemokines and chemokine receptors which have been associated with histopathological features of BCa patients in the world. This review highlights the chemokines and chemokine receptors as critical markers in early detection and therapeutic purposes among BCa patients and clarifies their molecular functions during BCa progression and metastasis.

Sublethal irradiation promotes the metastatic potential of hepatocellular carcinoma cells

Radiotherapy (RT) represents one of the major treatment methods for cancers. However, many studies have observed that in descendant surviving tumor cells, sublethal irradiation can promote metastatic ability, which is closely related to the tumor microenvironment. We therefore investigated the functions and mechanisms of sublethal irradiated liver nonparenchymal cells (NPCs) in hepatocellular carcinoma (HCC). In this study, primary rat NPCs and McA-RH7777 hepatoma cells were irradiated with 6 Gy X-ray. Conditioned media (CM) from nonirradiated (SnonR), irradiated (SR), or irradiated plus radiosensitizer celecoxib-treated (S[R + D]) NPCs were collected and added to sublethal irradiated McA-RH7777 cells. We showed that CM from sublethal irradiated NPCs significantly promoted the migration and invasion ability of sublethal irradiated McA-RH7777 cells, which was reversed by celecoxib. The differentially expressed genes in differently treated McA-RH7777 cells were enriched mostly in the AMP-activated protein kinase/mammalian target of rapamycin (AMPK/mTOR) signaling pathway. SR increased the migration and invasion ability of HCC cells by inhibiting AMPK/mTOR signaling, which was enhanced by the AMPK inhibitor compound C and blocked by the AMPK activator GSK-621. Analyses of HCC tissues after neoadjuvant radiotherapy confirmed the effects of radiation on the AMPK/mTOR pathway. Cytokine antibody arrays and further functional investigations showed that matrix metalloproteinase-8 (MMP-8) partly mediates the promotion effects of SR on the migration and invasion ability of HCC cells by regulating AMPK/mTOR signaling. In summary, our data indicate that MMP-8 secreted by irradiated NPCs enhanced the migration and invasion of HCC by regulating AMPK/mTOR signaling, revealing a novel mechanism mediating sublethal irradiation-induced HCC metastasis at the level of the tumor microenvironment.

Radiation-induced IL-1β expression and secretion promote cancer cell migration/invasion via activation of the NF-κB-RIP1 pathway

Here, we demonstrate that interleukin-1β (IL-1β) contributes to the γ-ionizing radiation (IR)-induced increase of migration/invasion in A549 lung cancer cells, and that this occurs via RIP1 upregulation. We initially observed that the protein expression and secreted concentration of IL-1β were increased upon exposure of A549 cells to IR. We then demonstrated that IR-induced IL-1β is located downstream of the NF-κB-RIP1 signaling pathway. Treatments with siRNA and specific pharmaceutical inhibitors of RIP1 and NF-κB suppressed the IR-induced increases in the protein expression and secreted concentration of IL-1β. IL-1Ra, an antagonist of IL-1β, treatment suppressed the IR-induced epithelial-mesenchymal transition (EMT) and IR-induced invasion/migration in vitro. These results suggest that IL-1β could regulate IR-induced EMT. We also found that IR could induce the expression of IL-1β expression in vivo and that of IL-1 receptor (R) I/II in vitro and in vivo. The IR-induced increases in the protein levels of IL-1 RI/II and IL-1β suggest that an autocrine loop between IL-1β and IL-1 RI/II might play important roles in IR-induced EMT and migration/invasion. Based on these collective results, we propose that IR concomitantly activates NF-κB and RIP1 to trigger the NF-κB-RIP1-IL-1β-IL-1RI/II-EMT pathway, ultimately promoting metastasis.

Silencing glioma-associated oncogene homolog 1 suppresses the migration and invasion of hepatocellular carcinoma in vitro

Hepatocellular carcinoma (HCC) is the fourth most common cause of cancer-associated death worldwide. Glioma-associated oncogene homolog 1 (Gli1) is a key component and functions as a reliable marker of Hedgehog signaling pathway activation. Previous studies have demonstrated that Gli1 serves important roles in the progression of various types of cancer, including HCC. However, its effect on HCC invasion and metastasis and the underlying mechanism remain to be elucidated. Small interference RNA was employed to silence the Gli1 gene in liver cancer cells. Reverse transcription-quantitative PCR and western blot analysis were performed to evaluate the mRNA and protein expression of Gli1, respectively. A series of assays, including Cell Counting Kit-8, adhesion, wound healing and Matrigel invasion were performed to investigate cell viability, adhesive, migratory and invasive capabilities of liver cancer cells, respectively. In addition, immunofluorescence staining was performed to determine the cellular localization of focal adhesion kinase (FAK), phosphorylated (p-)FAK and p-AKT. The mRNA and protein expression of Gli1 in liver cancer cells (HepG2 and SK-Hep1) were markedly decreased in a dose-dependent manner following Gli1-knockdown. Gli1 silencing significantly inhibited the adhesion, migration and invasion of SK-Hep1 cells. Additionally, knockdown of Gli1 markedly suppressed the expression of metalloproteinase (MMP)-2 and MMP-9. Furthermore, downregulation of Gli1 blocked the FAK/AKT signaling pathway. Gli1 serves significant roles in the migration and invasion of HCC cells through activation of the FAK/AKT signaling pathway and subsequent upregulation of MMP-2 and MMP-9 expression. Thus, Gli1 may be a potential protein target for the regulation of HCC migration and invasion.

Over-expression of MiR-122 promotes apoptosis of hepatocellular carcinoma via targeting TLR4

INTRODUCTION AND OBJECTIVE

MiR-122 has been regarded as a tumor suppressor. Toll-like receptor 4 (TLR4) has been found to be closely related to metastasis and immune escape of hepatocellular carcinoma (HCC). In the study, we sought to investigate the effect of miR-122 on HCC and the expression of TLR4.

PATIENTS OR MATERIALS AND METHODS

Real-time PCR and Western blot were performed to detect the expressions of target factors. CCK-8 and flow cytometry analysis were employed to evaluate cell viability and apoptosis, respectively. Luciferase reporter assay was used to determine whether miR-122 could directly regulate the expression of TLR4. Enzyme-linked Immuno Sorbent Assay was adopted to detect the secretion of inflammatory cytokines.

RESULTS

Both down-regulation of miR-122 and up-regulation of TLR4 were found to be correlated with low overall survival rate of HCC patients. TLR4 may be a direct target gene of miR-122. Over-expression of miR-122 induced apoptosis and inhibited cell viability of HCC by down-regulating TLR4, enhanced the expression of pro-apoptotic genes and suppressed the expression of anti-apoptotic genes. MiR-122 inhibited expressions and activities of inflammatory cytokines, including vascular endothelial growth factor (VEGF), interleukin 6 (IL-6), cyclooxygenase-2 (Cox-2) and prostaglandin E2 (PGE2) and also reduced the expression of matrix metallopeptidase 9 (MMP-9). Furthermore, activities of phosphatidylinositide 3-kinases (PI3K), Akt and nuclear factor-kappa B (NF-κB) were suppressed by miR-122.

CONCLUSIONS

Down-regulation of miR-122 facilitated the immune escape of HCC by targeting TLR4, which was related to PI3K/Akt/NF-κB signaling pathways. Our study may provide a possible strategy for the treatment of HCC.

Carbon Ion Radiotherapy in the Treatment of Pancreatic Cancer: A Review

Pancreatic cancer is the fourth most common cause of cancer-related morality worldwide, and the prognosis remains poor despite aggressive therapy. Carbon ion radiotherapy has favorable radiobiological and physical characteristics in the treatment, including a higher linear energy transfer and higher relative biological effectiveness, which increase the cell kill while potentially reducing toxicities to nearby normal tissues. Although small, early clinical studies have shown promise in both the resectable and unresectable settings to improve local control and overall survival while minimizing toxicities. Currently, there are several trials, including 2 sponsored by institutions in the United States, investigating the role of carbon ion radiotherapy for the treatment of locally advanced pancreatic cancer.

RIP1 Is a Novel Component of γ-ionizing Radiation-Induced Invasion of Non-Small Cell Lung Cancer Cells

Abstract: Previously, we demonstrated that γ-ionizing radiation (IR) triggers the invasion/migration of A549 cells via activation of an EGFR-p38/ERK-STAT3/CREB-1-EMT pathway. Here, we have demonstrated the involvement of a novel intracellular signaling mechanism in γ-ionizing radiation (IR)-induced migration/invasion. Expression of receptor-interacting protein (RIP) 1 was initially increased upon exposure of A549, a non-small cell lung cancer (NSCLC) cell line, to IR. IR-induced RIP1 is located downstream of EGFR and involved in the expression/activity of matrix metalloproteases (MMP-2 and MMP-9) and vimentin, suggesting a role in epithelial-mesenchymal transition (EMT). Our experiments showed that IR-induced RIP1 sequentially induces Src-STAT3-EMT to promote invasion/migration. Inhibition of RIP1 kinase activity and expression blocked induction of EMT by IR and suppressed the levels and activities of MMP-2, MMP-9 and vimentin. IR-induced RIP1 activation was additionally associated with stimulation of the transcriptional factor NF-κB. Specifically, exposure to IR triggered NF-κB activation and inhibition of NF-κB suppressed IR-induced RIP1 expression, followed by a decrease in invasion/migration as well as EMT. Based on the collective results, we propose that IR concomitantly activates EGFR and NF-κB and subsequently triggers the RIP1-Src/STAT3-EMT pathway, ultimately promoting metastasis.

Novel PI3K/Akt/mTOR pathway inhibitors plus radiotherapy: Strategy for non-small cell lung cancer with mutant RAS gene

Non-small cell lung cancer (NSCLC) with RAS -mutant gene has been the most difficult obstacle to overcome. Over 25% of muted lung adenocarcinomas have RAS mutation. The prognosis of NSCLC patients with RAS-mutant genes is always poor because there is no effective drug to suppress RAS-mutant genes. NSCLC patients with RAS-mutant usually develop resistance to radiotherapy and chemotherapy, which in some cases leads to a 5-10% survival rate for non-small cell lung cancer (NSCLC). As little clinical symptom of NSCLC was presented at its early stages, thus it always brings in disappointing treatment outcome. Currently, NSCLC presents the highest morbidity and mortality all over the world. The combination of PI3K/AKT/mTOR pathway inhibitors with radiotherapy is a novel strategy to improve radiosensitivity and therapeutic outcome of NSCLC with a RAS-mutant gene. There have been many preclinical studies and clinical trials on the effect of PI3K/AKT/mTOR pathway inhibitors combined with radiotherapy in NSCLC with a RAS-mutant gene have been reported in the past years. This review provides current knowledge of the combination of PI3K/Akt/mTOR pathway inhibitors with radiotherapy, which prove to be a significant improvement for the treatment of NSCLC patients with RAS mutations and will benefit NSCLC patients with RAS mutations.

Potential roles for the kisspeptin/kisspeptin receptor system in implantation and placentation

BACKGROUND

Initially identified as suppressors of metastasis in various types of cancer, kisspeptins are a family of neuropeptides that are key regulators of the mammalian reproductive axis. Accumulating evidence has shown that kisspeptin is able to control both the pulsatile and surge GnRH release, playing fundamental roles in female reproduction, which include the secretion of gonadotropins, puberty onset, brain sex differentiation, ovulation and the metabolic regulation of fertility. Furthermore, recent studies have demonstrated the involvement of the kisspeptin system in the processes of implantation and placentation. This review summarizes the current knowledge of the pathophysiological role and utility of these local placental regulatory factors as potential biomarkers during the early human gestation.

OBJECTIVE AND RATIONALE

A successful pregnancy, from the initiation of embryo implantation to parturition, is a complex process that requires the orchestration of a series of events. This review aims to concisely summarize what is known about the role of the kisspeptin system in implantation, placentation, early human pregnancy and pregnancy-related disorders, and to develop strategies for predicting, diagnosing and treating these abnormalities.

SEARCH METHODS

Using the PubMed and Google Scholar databases, we performed comprehensive literature searches in the English language describing the advancement of kisspeptins and the kisspeptin receptor (KISS1R) in implantation, placentation and early pregnancy in humans, since its initial identification in 1996 and ending in July 2018.

OUTCOMES

Recent studies have shown the coordinated spatial and temporal expression patterns of kisspeptins and KISS1R during human pregnancy. The experimental data gathered recently suggest putative roles of kisspeptin signaling in the regulation of trophoblast invasion, embryo implantation, placentation and early pregnancy. Dysregulation of the kisspeptin system may negatively affect the processes of implantation as well as placentation. Clinical studies indicate that the circulating levels of kisspeptins or the expression levels of kisspeptin/KISS1R in the placental tissues may be used as potential diagnostic markers for women with miscarriage and gestational trophoblastic neoplasia.

WIDER IMPLICATIONS

Comprehensive research on the pathophysiological role of the kisspeptin/KISS1R system in implantation and placentation will provide a dynamic and powerful approach to understanding the processes of early pregnancy, with potential applications in observational and analytic screening as well as the diagnosis, prognosis and treatment of implantation failure and early pregnancy-related disorders.

HER4 promotes the growth and metastasis of osteosarcoma via the PI3K/AKT pathway

Osteosarcoma is the most common primary malignant bone tumor, which occurs in adolescents. As reported by our previous studies, HER4 indicates a poor prognosis of primary osteosarcoma. However, its mechanisms in the pathogenesis of osteosarcoma have not yet been studied. The purpose of this study was to investigate the role of HER4 in osteosarcoma and whether the PI3K/AKT pathway is involved. In this study, western blot analysis was used to investigate the expression of HER4 protein in osteosarcoma tissues and cell lines. CCK8 and transwell assays were used to detect the effects of HER4 on the proliferation, migration, and invasion of osteosarcoma cells in vitro. The effects of HER4 on the growth and metastasis of osteosarcoma in vivo were detected by tumor formation and immunofluorescence in nude mice. The role of the PI3K/AKT pathway in HER4 regulation of the growth and metastasis of osteosarcoma was examined by western blot analysis and immunofluorescence assay. We found that HER4 protein was highly expressed in clinical osteosarcoma specimens and osteosarcoma cells. HER4 markedly promoted the proliferation, migration, and invasion of osteosarcoma cells in vitro as well as the growth and metastasis of osteosarcoma in vivo. HER4 overexpression upregulated the expression of phosphorylated protein kinase B (pAKT), proliferation marker antigen Ki67, and metastasis cell marker matrix metalloproteinase 9 (MMP9). Notably, PI3K/AKT inhibitor LY294002 significantly inhibited the effects of HER4 via the downregulation of pAKT, Ki67, and MMP9. Moreover, LY294002 markedly blocked the effects of HER4-induced upregulation of tumor malignancy. The present study suggests that HER4 may promote the growth and metastasis of osteosarcoma via the PI3K/AKT pathway. The HER4/PI3K/AKT pathway could serve as a potential target for the treatment of osteosarcoma.

Different Proteins Regulated Apoptosis, Proliferation and Metastasis of Lung Adenocarcinoma After Radiotherapy at Different Time

Introduction

The biological changes after irradiation in lung cancer cells are important to reduce recurrence and metastasis of lung cancer. To optimize radiotherapy of lung adenocarcinoma, our study systematically explored the mechanisms of biological behaviors in residual A549 and XWLC-05 cells after irradiation.

Methods

Colony formation assay, cell proliferation assay, cell migration assay, flow cytometry, BALB/C-nu mice xenograft models and Western blot of pan-AKT, p-Akt380, p-Akt473, PCNA, DNA-PKCS, KU70, KU80, CD133, CD144, MMP2 and P53 were used in our study to assess biological changes after irradiation with 0, 4 and 8 Gy at 0–336 hr after irradiation in vitro and 20 Gy at transplantation group, irradiated transplantation group, residual tumor 0, 7, 14, 21, and 28 days groups in vivo.

Results

The ability of cell proliferation and radiosensitivity of residual XWLC-05 cells was better than A549 cells after radiation in vivo and in vitro. MMP-2 has statistical differences in vitro and in vivo and increased with the migratory ability of cells in vitro. PCNA and P53 have statistical differences in XWLC-05 and A549 cells and the changes of them are similar to the proliferation of residual cells within first 336 hr after irradiation in vitro. Pan-AKT increased after irradiation, and residual tumor 21-day group (1.5722) has statistic differences between transplantation group (0.9763, p=0.018) and irradiated transplantation group (0.8455, p=0.006) in vivo. Pan-AKT rose to highest when 21-day after residual tumor reach to 0.5 mm². MMP2 has statistical differences between transplantation group (0.4619) and residual tumor 14-day group (0.8729, p=0.043). P53 has statistical differences between residual tumor 7-day group (0.6184) and residual tumor 28 days group (1.0394, p=0.007). DNA-PKCS has statistical differences between residual tumor 28 days group (1.1769) and transplantation group (0.2483, p=0.010), irradiated transplantation group (0.1983, p=0.002) and residual tumor 21 days group (0.2017, p=0.003), residual tumor 0 days group (0.5992) and irradiated transplantation group (0.1983, p=0.027) and residual tumor 21 days group (0.2017, p=0.002). KU80 and KU70 have no statistical differences at any time point.

Conclusion

Different proteins regulated apoptosis, proliferation and metastasis of lung adenocarcinoma after radiotherapy at different times. MMP-2 might regulate metastasis ability of XWLC-05 and A549 cells in vitro and in vivo. PCNA and P53 may play important roles in proliferation of vitro XWLC-05 and A549 cells within first 336 hr after irradiation in vitro. After that, P53 may through PI3K/AKT pathway regulate cell proliferation after irradiation in vitro. DNA-PKCS may play a more important role in DNA damage repair than KU70 and KU80 after 336 hr in vitro because it rapidly rose than KU70 and KU80 after irradiation. Different cells have different time rhythm in apoptosis, proliferation and metastasis after radiotherapy. Time rhythm of cells after irradiation should be delivered and more attention should be paid to resist cancer cell proliferation and metastasis.

Inhibitory Effects of Furanocoumarins From the Roots ofAngelica dahuricaon Ionizing Radiation-Induced Migration of A549 Human Non-Small Cell Lung Cancer Cells

Radiation therapy is a very effective tool for the treatment of advanced human lung cancers. However, as one of its malignancy-promoting behaviors, ionizing radiation (IR) increases cell migration and radiation resistance in several lung cancer cells, including non-small cell lung cancer (NSCLC) cells. As part of our ongoing search for potent radiotherapy enhancers from medicinal herbs, a chloroform-soluble fraction of the roots of Angelica dahurica was subjected to phytochemical investigation, leading to the isolation of 8 furanocoumarins. Of these, psoralen (1), xanthotoxin (2), and bergapten (3) inhibited IR-induced migration at a non-cytotoxic concentration (50 μM) in human NSCLC A549 cells. This study is the first to report on the inhibitory activities of these constituents of A. dahurica against IR-induced cancer metastasis.

Dietary flavonoid myricetin inhibits invasion and migration of radioresistant lung cancer cells (A549-IR) by suppressing MMP-2 and MMP-9 expressions through inhibition of the FAK-ERK signaling pathway

Myricetin is a commonly found dietary flavonoid. In the present study, we investigated the effects of myricetin on migration and invasion of radioresistant lung cancer cells (A549-IR). Transcriptome analysis of A549-IR cells identified several differentially expressed genes (DEGs) in A549-IR cells compared to parental A549 cells. Functional enrichment analysis revealed that most of the DEGs were linked with PI3K-AKT signaling, proteoglycans, focal adhesion, and ECM-receptor interactions. A549-IR cells demonstrated enhanced migratory potential with increased expression of vimentin, snail and slug, and reduced expression of E-cadherin. A549-IR cells exposed to myricetin displayed reduced migration and suppressed MMP-2 and MMP-9 expression. Notably, myricetin inhibited the phosphorylation of focal adhesion kinase (FAK) and altered the F-actin/G-actin ratio in A549-IR cells, without modulation of EMT markers. These findings suggest that myricetin can inhibit migration of A549-IR cells by suppressing MMP-2 and MMP-9 expressions through inhibition of the FAK-ERK signaling pathway.

A Discovery of Clinically Approved Formula FBRP for Repositioning to Treat HCC by Inhibiting PI3K/AKT/NF-κB Activation

Drug repositioning offers new clinical applications for existing drugs with shorter approval processes and lower costs and risks than de novo experimental drug development. The Fufang-Biejia-Ruangan pill (FBRP) is the first clinically approved anti-fibrosis herbal formula in China. Whether FBRP could be used to treat hepatocellular carcinoma (HCC) remains unclear. Herein, a total of 161 FBRP candidate targets against HCC were identified according to the topological importance in the "hepatic fibrosis-cirrhosis-cancer axis-related gene-FBRP putative target" network, and mostly enriched in phosphatidylinositol 3-kinase (PI3K)/AKT/nuclear factor κB (NF-κB) signaling. Experimentally, FBRP inhibited liver fibrosis and prevented the development of neoplastic lesions at the early stages of hepatocarcinogenesis in a diethylnitrosamine-induced rat HCC model. FBRP inhibited tumor cell proliferation, induced tumor-specific cell death, and suppressed tumor progression in HCC rats while preventing the activation of PI3K, AKT and IKΚB proteins, reducing the nuclear accumulation of NFΚB1 protein, and decreasing the downstream expression of proteins. Consistently, FBRP suppressed HCC cell proliferation and induced cell cycle arrest in vitro. Co-treatment of FBRP with PI3K inhibitor exhibited an additive inhibitory effect on PI3K/AKT/NF-κB activation. Collectively, our data showed the potentials of FBRP in hepatic fibrosis microenvironment regulation and tumor prevention, suggesting that FBRP may be a promising candidate drug for reduction of fibrogenesis and prevention of HCC.

TRIAP1 knockdown sensitizes non-small cell lung cancer to ionizing radiation by disrupting redox homeostasis

Background

Radioresistance of some non‐small cell lung cancer (NSCLC) types increases the risk of recurrence or metastasis in afflicted patients, following radiotherapy. As such, further improvements to NSCLC radiotherapy are needed. The expression of oncogene TP53‐regulated inhibitor of apoptosis 1 (TRIAP1) in NSCLC is increased following irradiation. Furthermore, gene set enrichment analysis (GSEA) has suggested that TRIAP1 might be involved in maintaining redox homeostasis. This in turn might enhance cell radioresistance.

Methods

In this study we irradiated human NSCLC cell lines (A549 and H460), while knocking down TRIAP1, to determine whether a disrupted redox homeostasis could attenuate radioresistance.

Results

Irradiation notably increased both mRNA and protein levels of TRIAP1. In addition, TRIAP1 knockdown decreased the expression of several antioxidant proteins, including thioredoxin‐related transmembrane protein (TMX) 1, TMX2, thioredoxin (TXN), glutaredoxin (GLRX) 2, GLRX3, peroxiredoxin (PRDX) 3, PRDX4, and PRDX6 in A549 and H460 cells. In addition, silencing TRIAP1 impaired the radiation‐induced increase of the aforementioned proteins. Continuing along this line, we observed a radiation‐induced reduction of cell viability and invasion, as well as increased apoptosis and intracellular reactive oxygen species following TRIAP1 knockdown.

Conclusions

In summary, we identified TRIAP1 as a key contributor to the radioresistance of NSCLC by maintaining redox homeostasis.

Gamma ray-induced in vitro cell migration via EGFR/ERK/Akt/p38 activation is prevented by olaparib pretreatment

Purpose: Radiotherapy using gamma ray is still the main therapeutic modality for the treatment of various cancers. However, local recurrence and increase of metastasis after radiotherapy is still a major therapeutic challenge. Aim of this work was to check cell migration along with activity and expression of some marker proteins involved in epithelial-mesenchymal transition (EMT) pathway in three different human cancer cells after exposure with gamma radiation in combination with PARP inhibitor olaparib.Materials and methods: Here, we presented cell viability, in vitro cell migration, activity of MMPs by gelatin zymography, expression of few EMT marker proteins and the signaling cascade involved in transcriptional regulation of MMPs after gamma irradiation with and without olaparib pretreatment in highly metastatic three human cancer cell lines-A549, HeLa and U2OS.Results: We observed that gamma irradiation alone increased in vitro cell migration, MMP-2,-9 activity, expression of N-cadherin, vimentin and the signaling molecules EGFR, ERK1/2, Akt, p38 that enhanced NF-kB expression in all three cell types. Olaparib treatment alone reduced in vitro cell migration along with reduction of expression of all the above-mentioned marker proteins of the EMT pathway. However, 4 h olaparib pretreatment prevented gamma ray induced activation of all these marker proteins in all three cell types.Conclusions: This data implicates that olaparib treatment in combination with gamma therapy could be promising in protecting patients from gamma-induced metastasis.

Role of fucosyltransferase IV in the migration and invasion of human melanoma cells

Malignant melanoma is one of the most aggressive human tumor types, mainly due to its high invasion capability, metastatic properties, and the absence of effective treatments. Glycosylation serves a pivotal role in the migration and invasion of melanoma. However, differences in glycosylation between high and low metastatic melanoma cells and how these regulate migration and invasion by altering the expression of fucosyltransferases (FUTs) remain unclear. In the present study, matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) analysis revealed that the composition profiling of fucosylated N-glycans differed between high metastatic C8161 and low metastatic A375P cells. Further analysis revealed that FUT4 expression was significantly increased in C8161 cells. Melanoma tissue arrays further demonstrated that FUT4 was overexpressed in metastatic samples. Altered FUT4 expression was accompanied by a change in the migration and invasion capacity of the cells. In addition, the migration and invasion potential of melanoma cells were decreased in C8161 and increased in A375P cells upon altering FUT4 expression levels by small interfering RNA or complementary DNA transfection. Furthermore, regulating FUT4 expression markedly modulated the activity of the phosphoinositide-3-kinase/Akt (PI3K/Akt) signaling pathway, which affected melanoma cell migration and invasion. In conclusion, FUT4 is a novel biomarker and regulator of the migration and invasion of melanoma cells and may serve as a therapeutic target for melanoma.

Anti-cancer effects of ethanol extract of Reynoutria japonica Houtt. radix in human hepatocellular carcinoma cells via inhibition of MAPK and PI3K/Akt signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Reynoutria japonica Houtt. has been used as a traditional medicine of cancer in East Asia for thousands of years. However, the mechanism of the anti-cancer effect of R. japonica has not been investigated at the molecular level. The regulation of intracellular signaling pathways by the extract of R. japonica radix needs to be evaluated for a deeper understanding and application of the anti-cancer effect of R. japonica radix.

AIM OF THE STUDY

The purpose of this study was to evaluate the inhibitory effects of the ethanol extracts of R. japonica radix (ERJR) on cancer metastasis and the regulation mechanism of metastasis by ERJR in human hepatocellular carcinomas.

MATERIALS AND METHODS

Suppression of cancer metastasis by ERJR in SK-Hep1 and Huh7 cells were investigated. Prior to experiments, the cytotoxic effect of ERJR was examined by cell viability assays. To evaluate the inhibitory effects of ERJR on cancer metastasis, wound-healing assays, invasion assays, zymography, and multicellular tumor spheroids (MCTS) assays were performed. Molecular mechanisms in the suppressive regulation of metastasis by ERJR were verified by measuring the expression levels of metastatic markers, and the phosphorylation and protein levels of cancer metastasis-related signaling pathways.

RESULTS

In all experiments, ERJR was used at a maximum concentration of 20 μg/ml, which did not show cytotoxicity in SK-Hep1 and Huh7 cells. We examined the inhibitory effects of ERJR on cancer metastasis. In wound-healing and invasion assays, ERJR treatment effectively suppressed the wound-recovery of Huh7 cells and inhibited the invasion ability of SK-Hep1 cells. Also, ERJR treatment significantly decreased the enzymatic activity of matrix metalloproteinase-2 and -9 in SK-Hep1 cells. ERJR suppressed the growth of MCTS in SK-Hep1 cells in a dose-dependent manner. These results indicated that ERJR effectively inhibited the invasive and proliferative ability of SK-Hep1 and Huh7 cells. Moreover, ERJR treatment reduced the expression levels of Snail1, Twist1, N-cadherin, and Vimentin, which are metastatic markers, by inhibiting the activation of protein kinase B and mitogen-activated protein kinases in SK-Hep1 cells.

CONCLUSIONS

These results verified the molecular mechanism of ERJR that has been used in traditional anti-cancer remedy and suggest that it can be developed as a promising therapy for cancer metastasis in the future.

RMP/URI inhibits both intrinsic and extrinsic apoptosis through different signaling pathways

The evading apoptosis of tumor cells may result in chemotherapy resistance. Therefore, investigating what molecular events contribute to drug-induced apoptosis, and how tumors evade apoptotic death, provides a paradigm to explain the relationship between cancer genetics and treatment sensitivity. In this study, we focused on the role of RMP/URI both in cisplatin-induced endogenous apoptosis and in TRAIL-induced exogenous apoptosis in HCC cells. Although flow cytometric analysis indicated that RMP overexpression reduced the apoptosis rate of HCC cells treated with both cisplatin and TRAIL, there was a difference in mechanism between the two treatments. Western blot showed that in intrinsic apoptosis induced by cisplatin, the overexpression of RMP promoted the Bcl-xl expression both in vitro and in vivo. Besides, RMP activated NF-κB/p65(rel) through the phosphorylation of ATM. However, in TRAIL-induced extrinsic apoptosis, RMP significantly suppressed the transcription and expression of P53. Moreover, the forced expression of P53 could offset this inhibitory effect. In conclusion, we presumed that RMP inhibited both intrinsic and extrinsic apoptosis through different signaling pathways. NF-κB was distinctively involved in the RMP circumvention of intrinsic apoptosis, but not in the extrinsic apoptosis of HCC cells. RMP might play an important role in defects of apoptosis, hence the chemotherapeutic resistance in hepatocellular carcinoma. These studies are promising to shed light on a more rational approach to clinical anticancer drug design and therapy.

Increased expression of MMP-2 and MMP-9 indicates poor prognosis in glioma recurrence

The main characteristic of glioma is recurrence, even after intensive multidisciplinary treatment. Studies show that enhanced invasive ability will increase the ability of tumor cells to escape from the primary tumor mass, which is a key factor contributing to tumor relapse and recurrence. In this study, we assessed the expression of MMP-2, MMP-9, two important matrix metallopeptidases that increase the invasive ability of glioma, and their suppressors, TIMP-1, TIMP-2 in glioma tissues from primary and recurrent glioma patients by immunohistochemistry. Glioma cells and nude mice were used for in vitro and in vivo studies. Results showed that the expression of MMP-2 and MMP-9 in recurrent gliomas were significantly higher than those in primary gliomas (P = 3.075 × 10^{-11, P = 1.510 × 10-5}, respectively). We also found that radiotherapy increased the expression of MMP-9, but had no effect on MMP-2 and TIMP-1/2. With glioma cell line U251, we found that irradiation increased the expression of MMP-9 in vitro. Tumor tissues from an orthotopic xenograft model showed that after irradiation treatment, the expression of MMP-9 increased significantly in vivo. We also found that knocking down MMP-9 decreased irradiation-induced invasion obviously. Above all, we concluded that higher expressions of MMP-2/-9 indicate poor prognosis in glioma recurrence. The increased expression of MMP-9 after radiotherapy suggests that MMP-9 might be an important target in the radiosensitization of glioma.

Heavy-ion beam irradiation inhibits invasion of tongue squamous cell carcinoma Tca8113 cells

Tongue squamous cell carcinoma (TSCC) is a common malignant tumor type with aggressive biological characteristics, located in the oral and maxillofacial region. Vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs) have been implicated in the invasion and metastasis of various malignant tumor types, such as lung cancer and gastric carcinoma. High linear energy transfer (LET) particle irradiation has several advantages over conventional X-rays in suppressing the invasion and metastasis of malignant tumors. The objective of the present study was to investigate the effects of high-LET carbon ions and low-LET X-rays on the expression of VEGF and MMPs, and to identify the associated mechanisms in the Tca8113 TSCC cell line. Tca8113 cells were irradiated with carbon ions or X-rays at doses of 1 and 4 Gy. An immunofluorescence assay indicated that VEGF expression was notably decreased at 24 and 48 h after heavy ion irradiation compared with irradiation with conventional X-rays. The expression of MMP-2 and MMP-9 also decreased in a dose-dependent manner following heavy ion irradiation. These findings indicate that compared with low-LET X-ray irradiation, high-LET carbon ions possess higher biological efficacy in inhibiting the invasive ability of Tca8113 cells via reduction of VEGF, MMP-2 and MMP-9 expression.

Novel interactions between ERα-36 and STAT3 mediate breast cancer cell migration

Background

Breast cancer is the leading cause of cancer death in women worldwide which is closely related to metastasis. But the exact molecular mechanism of ERα-36 and STAT3 on metastasis is still not fully understood.

Methods

MCF-7 and MDA-MB-231 human breast cancer cell lines and MCF-10A were overexpressioned or knockdown ERα-36 and STAT3 and tested for migration, invasion and proliferation assays. Direct interaction of STAT3 and ERα-36 were analyzed by coimmunoprecipitation assays. The effect of STAT3 and ERα-36 on MMP2/9 expression was analyzed by qPCR and western blotting. STAT3 phospholyation and acetylation by ERα-36 and p300 were observed and quantified by coimmunoprecipitation assays and western blotting.

Results

Cross-talk between ERα-36 and STAT3 was demonstrated to mediate through a direct physical association between the two proteins. Furthermore, the interaction between ERα-36 and STAT3 was demonstrated to give rise to functional changes in their signaling events. Both MMP2 and MMP9 expression require the binding of the newly identified protein complex, ERα-36-STAT3, to its promoter, the second phase, which is more robust, depends on ERα-mediated recruitment of p300 onto the complex and the subsequent acetylation of STAT3. In addition, STAT3 is tyrosine-phosphorylated in a biphasic manner, and the late phase requires ERα-36-mediated p300-dependent acetylation. Furthermore, interference with acetylation of STAT3 by overexpression of acetylation null STAT3 mutant led to the loss of MMP2 and MMP9 expression. ChIP analysis and reporter gene assays revealed that ERα-36-STAT3 complex binding to the MMP2 and MMP9 promoter led to an enhanceosome formation and facilitated MMP2 and MMP9 expression.

Conclusions

Our studies demonstrate for the first time that the function of MMP2 and MMP9 in breast cancer cell migration, which is mediated by interactions between ERα-36 and STAT3.

Circular RNA circSLC8A1 acts as a sponge of miR-130b/miR-494 in suppressing bladder cancer progression via regulating PTEN

Background

Circular RNAs (circRNAs) are a novel class of endogenous noncoding RNAs formed by a covalently closed loop, and increasing evidence has revealed that circRNAs play crucial functions in regulating gene expression. CircSLC8A1 is a circRNA generated from the SLC8A1 gene. Currently, the role and underlying molecular mechanisms of circSLC8A1 in bladder cancer remain unknown.

Methods

The differentially expressed circRNAs were identified from RNA-sequencing data, and circSLC8A1 was determined as a new candidate circRNA. qRT-PCR was used to detect the expression of circRNAs, miRNAs and mRNAs in human tissues and cells. RNA pull-down assay and luciferase reporter assay were used to investigate the interactions between the specific circRNA, miRNA and mRNA. The effects of circSLC8A1 on bladder cancer cells were explored by transfecting with plasmids in vitro and in vivo. The expression of PTEN was detected by Western blot. The biological roles were measured by wound healing assay, transwell assay, and CCK-8 assay.

Results

In the present study, we found that circSLC8A1 was down-regulated in bladder cancer tissues and cell lines, and circSLC8A1 expression was associated with the pathological stage and histological grade of bladder cancer. Over-expression of circSLC8A1 inhibited cell migration, invasion and proliferation both in vitro and in vivo. Mechanistically, circSLC8A1 could directly interact with miR-130b/miR-494, and subsequently act as a miRNA sponge to regulate the expression of the miR-130b/miR-494 target gene PTEN and downstream signaling pathway, which suppressed the progression of bladder cancer.

Conclusions

CircSLC8A1 acts as a tumor suppressor by a novel circSLC8A1/miR-130b, miR-494/PTEN axis, which may provide a potential biomarker and therapeutic target for the management of bladder cancer.

Electronic supplementary material

The online version of this article (10.1186/s12943-019-1040-0) contains supplementary material, which is available to authorized users.

Targeting the mTOR regulatory network in hepatocellular carcinoma: Are we making headway?

The mechanistic target of rapamycin (mTOR) pathway coordinates organismal growth and homeostasis in response to growth factors, nutrients, and cellular energy stage. The pathway regulates several major cellular processes and is implicated in various pathological conditions, including hepatocellular carcinoma (HCC). This review summarizes recent advances of the mTOR pathway, highlights the potential of the mTOR pathway as a therapeutic target, and explores clinical trials targeting the mTOR pathway in HCC. Although the review focuses on the mTOR pathway involved in HCC, more comprehensive discussions (eg, developing a rational design for future trials targeting the mTOR pathway) are also applicable to other tumors.

Role of RASEF hypermethylation in cigarette smoke-induced pulmonary arterial smooth muscle remodeling

Background

Pulmonary hypertension (PH) is a progressive and fatal disease. While cigarette smoke can change DNA methylation status, the role of such molecular alterations in smoke-associated PH is unclear.

Methods

A PH rat model was developed by exposing animals to cigarette smoke for 3 months. Right ventricular systolic pressure was measured with a right heart catheter. Histological changes (right ventricular hypertrophy index, medial wall thickness in pulmonary arteries (PAs)) and DNMT1 protein levels in rat PAs or primary human PA smooth muscle cells (HPASMCs) exposed to cigarette smoke extract were assessed. Methylation sequencing and MassArray® were used to detect genomic and RASEF promoter methylation status, respectively. After DNMT1 knockdown and cigarette smoke extract exposure, HPASMCs behavior (proliferation, migration) and RASEF methylation status were examined; RASEF mRNA expression was evaluated by real-time-polymerase chain reaction. RASEF overexpression viral vectors were used to assess the impact of RASEF on rat PH and HPASMCs remodeling.

Results

Higher right ventricular systolic pressure, medial wall thickness, and right ventricular hypertrophy index values were observed in the smoking group rats. Smoke exposure increased DNMT1 expression and RASEF methylation levels in rat PAs and HPASMCs. Cigarette smoke extract induced HPASMCs behavioral changes and RASEF hypermethylation followed by silencing, while DNMT1 knockdown markedly inhibited these changes. RASEF overexpression distinctly inhibited PH and HPASMCs remodeling, possibly through phospho-AKT (Ser473), PCNA, and MMP9 downregulation.

Conclusions

Cigarette smoke caused PA remodeling in PH rats related to RASEF hypermethylation. These results expand our understanding of key epigenetic mechanisms in cigarette smoke-associated PH and potentially provide a novel therapeutic target for PH.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1014-1) contains supplementary material, which is available to authorized users.

Suppression of PMA-induced human fibrosarcoma HT-1080 invasion and metastasis by kahweol via inhibiting Akt/JNK1/2/p38 MAPK signal pathway and NF-κB dependent transcriptional activities

Coffee is one of the widely sales beverage worldwide and contains numerous phytochemicals that are beneficial to health. Kahweol acetate (KA), a coffee-specific diterpene, exhibits anti-tumoric properties in human tumoric cells. However, the effect of KA on the metastasis and invasion of cancer cells and the underlying mechanisms remain unclear. The objectives of this study were to estimate the anti-tumor activity of KA and reveal the possible molecular mechanisms. KA markedly inhibited the cell proliferation enhanced by phorbol 12-myristate 13-acetate (PMA) in human fibrosarcoma cells. As well as, KA attenuated PMA-induced cell migration and invasion in a concentration-dependent manner. KA suppressed PMA-enhanced activation of matrix metalloproteinase-9 (MMP-9) through suppression of nuclear factor kappa B (NF-κB) activation. KA repressed the PMA-induced phosphorylation of Akt, c-Jun N-terminal kinase (JNK) 1/2, and p38 MAPK, which are signaling molecules upstream of MMP-9 expression. In summary, we demonstrated that the anti-tumor effects of KA might occur through the inhibition of Akt/JNK1/2/p38 MAPK phosphorylation and downregulation of NF-κB activation, leading to a decrease in MMP-9 expression. Thus, KA is a useful chemotherapeutic agent that may contribute to prevent to the metastatic tumor.

Hypoxia and tumor angiogenesis in the era of hepatocellular carcinoma transarterial loco-regional treatments

This review focuses upon interactions and potential therapeutic targets in the ‘vicious cycle’ between hypoxia and neoangiogenesis following treatment of hepatocellular carcinoma with transarterial loco-regional therapies. Biomarkers correlated with angiogenesis have been studied by many authors as prognostic determinants following transarterial intrahepatic therapy. According to these results future therapies directed toward specific factors related to angiogenesis could play a significant role in preventing local tumor recurrence and remote metastasis.