A combined modality of carboplatin and photodynamic therapy suppresses epithelial-mesenchymal transition and matrix metalloproteinase-2 (MMP-2)/MMP-9 expression in HEp-2 human laryngeal cancer cells via ROS-mediated inhibition of MEK/ERK signalling pathway

Hematoporphyrin derivative photodynamic therapy induces apoptosis and suppresses the migration of human esophageal squamous cell carcinoma cells by regulating the PI3K/AKT/mTOR signaling pathway

Esophageal cancer is one of the most common cancer types in humans worldwide. Photodynamic therapy (PDT) is a promising therapeutic strategy for the treatment of cancer. However, its underlying mechanism needs to be studied thoroughly. The present study focused on the antitumor effect and underlying mechanism of the use of hematoporphyrin derivative (HpD)-PDT against human esophageal squamous cell carcinoma cells via regulation of the PI3K/AKT/mTOR signaling pathway. A Cell Counting Kit-8 assay was used to measure cell viability. Migration was evaluated using a wound healing assay. An annexin V-FITC/PI kit was used to determine cell apoptosis rates. Protein expression levels were analyzed via western blotting. Reverse transcription-quantitative PCR was used to detect gene expression levels. A 2',7'-dichlorodihydrofluorescein diacetate kit was chosen to evaluate intracellular reactive oxygen species levels via flow cytometry. Cell viability and migration were decreased in KYSE-150 cells after HpD-PDT treatment. Cellular apoptosis was induced after HpD-PDT treatment, and the same trend was observed for autophagy. Furthermore, the PI3K/AKT/mTOR signaling pathway was inhibited. The viability and migration of KYSE-150 cells were significantly inhibited, and apoptosis was induced more effectively following treatment with a combination of HpD-PDT and the PI3K inhibitor, a final concentration of 20 µM LY294002. In conclusion, HpD-PDT could suppress esophageal cancer cell viability, induce apoptosis and inhibit migration by downregulating the PI3K/AKT/mTOR signaling pathway. Combination of HpD-PDT with PI3K inhibitor (LY294002) could enhance the therapeutic efficacy compared with that demonstrated by HpD-PDT alone. Further studies on combination therapy are required to achieve improved clinical outcomes.

Ipatasertib, an oral AKT inhibitor, in combination with carboplatin exhibits anti-proliferative effects in uterine serous carcinoma

PURPOSE

Uterine serous carcinoma (USC) exhibits worse survival rates compared to the endometrioid subtype, and there is currently no effective treatment options for recurrence of this disease after platinum-based chemotherapy. Activation of PIK3CA/AKT/mTOR signaling pathway is a common biological feature in USC.

MATERIALS AND METHODS

Ipatasertib (IPAT) is an investigational, orally administered, ATP-competitive, highly selective inhibitor of pan AKT that has demonstrated anti-proliferative activity in a variety of tumor cells and tumor models. In this study, we used IPAT, carboplatin and their combination to investigate the anti-tumor activity in SPEC-2 and ARK-1 cells.

RESULTS

Our results indicate that IPAT combined with carboplatin at low doses was more effective at reducing proliferation, inducing apoptosis and causing cellular stress than IPAT or carboplatin alone. In particular, inhibition of the PIK3CA/AKT/mTOR pathway and induction of DNA damage were involved in the synergistic inhibition by combination treatment of cell viability in USC cells treated with the combination. Furthermore, IPAT in combination with carboplatin significantly reduced cell adhesion and inhibited cell invasion.

CONCLUSIONS

These findings suggest that the combination of IPAT and carboplatin has potential clinical implications for developing new USC treatment strategies.

A novel 450-nm laser-mediated sinoporphyrin sodium-based photodynamic therapy induces autophagic cell death in gastric cancer through regulation of the ROS/PI3K/Akt/mTOR signaling pathway

BACKGROUND

Photodynamic therapy (PDT) has become an ideal and promising therapeutic method for fighting cancer, but its common application in clinical practice is prevented by the limitations of expensive devices in light sources and phototoxicity in photosensitizers. The aim of this study was to explore the antitumor efficiency of the novel 450-nm blue laser (BL) combined with sinoporphyrin sodium (DVDMS)-mediated PDT against human gastric cancer (GC) in vitro and in vivo, focusing on autophagy pathway.

METHODS

Cell viability was detected by Cell Counting Kit-8 and colony formation assays in HGC27, MGC803, AGS, and GES-1 cells. Cell apoptosis was measured by flow cytometry and western blotting. The production of reactive oxygen species (ROS) was measured by fluorescence microscopy and flow cytometry. Autophagy was determined by transmission electron microscopy and western blotting. The antitumor effect of BL-PDT in vivo was detected by a subcutaneous tumor model in nude mice.

RESULTS

The novel 450-nm laser-mediated DVDMS-based PDT caused remarkable growth inhibition and apoptosis induction in GC cells in vitro by the production of excessive ROS. Autophagy flux was induced by BL-PDT in GC cells, as determined by LC3 conversion assay, LC3 turnover assay, and mRFP-GFP-LC3 puncta assay. Furthermore, autophagy induction was demonstrated to positively contribute to BL-PDT-induced apoptotic effects on GC cells. Mechanically, ROS/PI3K/Akt/mTOR pathway was identified to involve in the regulation of BL-PDT-induced autophagy as determined by transcriptomic analysis and functional studies. Consistently, xenograft studies confirmed the significant antitumor effect of BL-PDT and its favorable safety in vivo.

CONCLUSIONS

The novel 450-nm laser-mediated DVDMS-based PDT may be a safe and effective approach against GC. Our results thus provide compelling evidence for the therapeutic application of BL-PDT in human GC.

Increasing cancer permeability by photodynamic priming: from microenvironment to mechanotransduction signaling

The dense cancer microenvironment is a significant barrier that limits the penetration of anticancer agents, thereby restraining the efficacy of molecular and nanoscale cancer therapeutics. Developing new strategies to enhance the permeability of cancer tissues is of major interest to overcome treatment resistance. Nonetheless, early strategies based on small molecule inhibitors or matrix-degrading enzymes have led to disappointing clinical outcomes by causing increased chemotherapy toxicity and promoting disease progression. In recent years, photodynamic therapy (PDT) has emerged as a novel approach to increase the permeability of cancer tissues. By producing excessive amounts of reactive oxygen species selectively in the cancer microenvironment, PDT increases the accumulation, penetration depth, and efficacy of chemotherapeutics. Importantly, the increased cancer permeability has not been associated to increased metastasis formation. In this review, we provide novel insights into the mechanisms by which this effect, called photodynamic priming, can increase cancer permeability without promoting cell migration and dissemination. This review demonstrates that PDT oxidizes and degrades extracellular matrix proteins, reduces the capacity of cancer cells to adhere to the altered matrix, and interferes with mechanotransduction pathways that promote cancer cell migration and differentiation. Significant knowledge gaps are identified regarding the involvement of critical signaling pathways, and to which extent these events are influenced by the complicated PDT dosimetry. Addressing these knowledge gaps will be vital to further develop PDT as an adjuvant approach to improve cancer permeability, demonstrate the safety and efficacy of this priming approach, and render more cancer patients eligible to receive life-extending treatments.

Effects of Curcumin-mediated photodynamic therapy on autophagy and Epithelial-mesenchymal transition of lung cancer cells

BACKGROUND

This study aimed to investigated whether Curcumin-mediated PDT suppress EMT in lung cancer cells, and explore the roles of autophagy in the process of regulating EMT.

METHODS

Lung cancer cell viability was assessed by CCK-8 assay. The expression of epithelial marker and mesenchymal markers, the conversion of LC3-I to LC3-II and the levels of p62 and beclin1 in A549 and SPCA1 cells were measured by Western blotting assay. The Wound healing and Transwell assays were used to detect the migration and invasion abilities of the A549 and SPCA1 cells. Autophagosome formation was detected via observing the colocalization of Lamp-2 with LC3 in A549 cells, and the autophagy ultrastructure was observed by TEM.

RESULTS

Curcumin-PDT inhibited EMT, migration and invasion and induced autophagy in lung cancer cells. Curcumin-PDT induced autophagy was involved in the process of PDT inhibiting EMT, but it presented a promoting effect of EMT in lung cancer cells. Curcumin-PDT combined with CQ further inhibited EMT, invasion and migration of lung cancer cells.

CONCLUSIONS

The role of PDT-induced autophagy in the regulation of EMT was determined to be a promoting effect in lung cancer. Therefore, Curcumin-mediated PDT combined with autophagy inhibitor further suppressed EMT of lung cancer cells, and may represent a potential strategy against invasion and migration of lung cancer.

Overexpression of STAT4 under hypoxia promotes EMT through miR-200a/STAT4 signal pathway

AIMS

Previous reports have found that STAT4 is involved in the epithelial-mesenchymal transition (EMT), thereby regulating the metastasis and invasion of ovarian cancer. However, the mechanisms underlying remain unclear.

MAIN METHODS

We first established hypoxia-induced in vivo and in vitro models. The expression levels of signal transducer and activator of transcription 4 (STAT4), the markers of EMT and microRNA-200a (miR-200a) were assessed by western blot and qRT-PCR analysis, respectively. Through the bioinformatics analysis and luciferase assay, the relationship between miR-200a and SATA4 was performed. The gain- and loss-function experiments were performed to examine the role of miR-200a/STAT4 axis.

KEY FINDINGS

The results showed that the protein level of STAT4 was significantly up-regulated in our hypoxia-exposed models, and contributed to the regulating of EMT. Besides, we found STAT4 was a direct target of miR-200a. Overexpression of miR-200a repressed the expression of STAT4, and inhibited EMT progress, whereas the silencing of miR-200a promoted the STAT4-mediated EMT regulation both in vitro and in vivo.

SIGNIFICANCE

Our results provided a potential molecular mechanism by which miR-200a involved in hypoxia-induced metastasis and invasion in ovarian cancer, suggesting a possible target for the treatment of ovarian cancer.

Magnesium Isoglycyrrhizinate Induces an Inhibitory Effect on Progression and Epithelial-Mesenchymal Transition of Laryngeal Cancer via the NF-κB/Twist Signaling

Background

Magnesium isoglycyrrhizinate (MI) was extracted from roots of the plant Glycyrrhiza glabra, which displays multiple pharmacological activities such as anti-inflammation, anti-apoptosis, and anti-tumor. Here, we aimed to investigate the effect of MI on the progression and epithelial–mesenchymal transition (EMT) of laryngeal cancer.

Methods

Forty laryngeal cancer clinical samples were used. The role of MI in the proliferation of laryngeal cancer cells was assessed by MTT assay, Edu assay and colony formation assay. The function of MI in the migration and invasion of laryngeal cancer cells was tested by transwell assays. The effect of MI on apoptosis of laryngeal cancer cells was determined by cell apoptosis assay. The impact of MI on tumor growth in vivo was analyzed by tumorigenicity analysis using Balb/c nude mice. qPCR and Western blot analysis were performed to measure the expression levels of gene and protein, respectively.

Results

We identified that EMT-related transcription factor Twist was significantly elevated in the laryngeal cancer tissues. The expression of Twist was also enhanced in the human laryngeal carcinoma HEP-2 cells compared with that in the primary laryngeal epithelial cells. The high expression of Twist was remarkably correlated with poor overall survival of patients with laryngeal cancer. Meanwhile, our data revealed that MI reduced cell proliferation, migration and invasion and enhanced apoptosis of laryngeal cancer cells in vitro. Moreover, MI decreased transcriptional activation and the expression levels of NF-κB and Twist, and alleviated EMT in vitro and in vivo. MI remarkably inhibited tumor growth and EMT of laryngeal cancer cells in vivo.

Conclusion

MI restrains the progression of laryngeal cancer and induces an inhibitory effect on EMT in laryngeal cancer by modulating the NF-κB/Twist signaling. Our finding provides new insights into the mechanism by which MI inhibits laryngeal carcinoma development, enriching the understanding of the anti-tumor function of MI.

Suppression of KIF3A inhibits triple negative breast cancer growth and metastasis by repressing Rb-E2F signaling and epithelial-mesenchymal transition

Triple negative breast cancer (TNBC) displays higher heterogeneity, stronger invasiveness, higher risk of metastasis and poorer prognosis compared with major breast cancer subtypes. KIF3A, a member of the kinesin family of motor proteins, serves as a microtubule-directed motor subunit and has been found to regulate early development, ciliogenesis and tumorigenesis. To explore the expression, regulation and mechanism of KIF3A in TNBC, 3 TNBC cell lines, 98 cases of primary TNBC and paired adjacent tissues were examined. Immunohistochemistry, real-time PCR, western blot, flow cytometry, short hairpin RNA (shRNA) interference, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation techniques, transwell assays, scratch tests, and xenograft mice models were used. We found that KIF3A was overexpressed in TNBC and such high KIF3A expression was also associated with tumor recurrence and lymph node metastasis. Silencing of KIF3A suppressed TNBC cell proliferation by repressing the Rb-E2F signaling pathway and inhibited migration and invasion by repressing epithelial-mesenchymal transition. The tumor size was smaller and the number of lung metastatic nodules was lower in KIF3A depletion MDA-MB-231 cell xenograft mice than in the negative control group. In addition, KIF3A overexpression correlated with chemoresistance. These results suggested that high expression of KIF3A in TNBC was associated with the tumor progression and metastasis.

Leucine Zipper-EF-Hand Containing Transmembrane Protein 1 Is a Potential Prognostic Biomarker and Promotes Cell Progression in Prostate Cancer

Purpose

The leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) is a mitochondrial protein that has been associated with the occurrence and development of malignant tumors. Previous studies have shown that LETM1 expression is increased in several types of human cancer and is associated with a poor clinical outcome. However, the role of LETM1 in prostate cancer (PCa) has not yet been determined. In this study, we investigated the clinicopathological significance of LETM1 expression and its role in PCa progression.

Methods

We assessed the expression of LETM1 and genes related to cancer stemness, epithelial-mesenchymal transition (EMT), cell cycle, and PI3K/Akt signaling in 133 paraffin-embedded PCa tissue samples and cancer cells by using immunohistochemistry, immunofluorescence, and Western blotting.

Results

LETM1 expression was significantly increased in PCa, and it was positively correlated with Gleason score, pathologic tumor (pT) stage, clinical stage, and high microvessel density. Survival analysis showed that patients with PCa with a high level of LETM1 expression exhibited a low overall survival. Cox regression analysis indicated that LETM1 is an independent poor prognostic PCa factor. Additionally, the expression of LETM1 was correlated with cancer cell stemness-associated genes, EMT-related genes, cell cycle regulatory genes, and PI3K/Akt signaling gene expression in PCa. Furthermore, knocking down LETM1 expression down-regulated the expression of stemness-related proteins, while inhibiting tumor spheroid formation, EMT-like changes, cell proliferation, migration, and invasion in PCa cells. Importantly, the PI3K inhibitor LY294002 strongly inhibited the expression of LETM1, pPI3K-p85, and pAkt (Thr308, Ser473) in PCa cells.

Conclusion

These results indicate that LETM1 expression is associated with cancer cell stemness, promotes EMT-like changes and cell proliferation and is a potential prognostic biomarker for PCa.

Enhanced and Prolonged Antitumor Effect of Salinomycin-Loaded Gelatinase-Responsive Nanoparticles via Targeted Drug Delivery and Inhibition of Cervical Cancer Stem Cells

Background

Cervical cancer stem cells (CCSCs) represent a subpopulation of tumor cells that possess self-renewal capacity and numerous intrinsic mechanisms of resistance to conventional chemotherapy and radiotherapy. These cells play a crucial role in relapse and metastasis of cervical cancer. Therefore, eradication of CCSCs is the primary objective in cervical cancer therapy. Salinomycin (Sal) is an agent used for the elimination of cancer stem cells (CSCs); however, the occurrence of several side effects hinders its application. Nanoscale drug-delivery systems offer great promise for the diagnosis and treatment of tumors. These systems can be used to reduce the side effects of Sal and improve clinical benefit.

Methods

Sal-loaded polyethylene glycol-peptide-polycaprolactone nanoparticles (Sal NPs) were fabricated under mild and non-toxic conditions. The real-time biodistribution of Sal NPs was investigated through non-invasive near-infrared fluorescent imaging. The efficacy of tumor growth inhibition by Sal NPs was evaluated using tumor xenografts in nude mice. Flow cytometry, immunohistochemistry, and Western blotting were used to detect the apoptosis of CSCs after treatment with Sal NPs. Immunohistochemistry and Western blotting were used to examine epithelial–mesenchymal transition (epithelial interstitial transformation) signal-related molecules.

Results

Sal NPs exhibited antitumor efficacy against cervical cancers by inducing apoptosis of CCSCs and inhibiting the epithelial–mesenchymal transition pathway. Besides, tumor pieces resected from Sal NP-treated mice showed decreased reseeding ability and growth speed, further demonstrating the significant inhibitory ability of Sal NPs against CSCs. Moreover, owing to targeted delivery based on the gelatinase-responsive strategy, Sal NPs was more effective and tolerable than free Sal.

Conclusion

To the best of our knowledge, this is the first study to show that CCSC-targeted Sal NPs provide a potential approach to selectively target and efficiently eradicate CCSCs. This renders them a promising strategy to improve the therapeutic effect against cervical cancer.

STRIP2, a member of the striatin-interacting phosphatase and kinase complex, is implicated in lung adenocarcinoma cell growth and migration

Lung adenocarcinoma (LUAD) accounts for ~40% of lung cancer cases, and the 5-year relative survival rate is no more than 1%. Dysregulation of components of striatin-interacting phosphatase and kinase (STRIPAK) complexes is associated with various diseases, including cancer. Striatin-interacting protein 2 (STRIP2), also called Fam40b, has been reported to regulate tumor cell growth and migration. Here, we investigated the role of STRIP2 in LUAD growth, migration and the underlying mechanisms. Analysis of data from The Cancer Genome Atlas database revealed that STRIP2 is highly expressed and predicted poor outcomes in patients with LUAD. Moreover, quantitative RT-PCR (qRT-PCR) analysis revealed that the mRNA expression of STRIP2 is greater in all tested LUAD cells than in a normal lung cell line. To investigate the function of STRIP2, we overexpressed STRIP2 in SPC-A1 cells and depleted STRIP2 in Calu-3 cells. Cell proliferation was evaluated by Cell Counting Kit-8 and colony-forming assays, and Transwell assay was employed to test cell invasion and migration. Our results indicate that STRIP2 depletion suppressed cell proliferation, invasion and migration in Calu-3 cells, and overexpression of STRIP2 had the opposite effects in SPC-A1 cells. Moreover, we discovered that STRIP2 depletion reduced the protein levels of p-Akt and phosphorylated-mammalian target of rapamycin (p-mTOR) in Calu-3 cells, whereas STRIP2 overexpression increased levels of these proteins in SPC-A1 cells. Furthermore, we found that silencing of STRIP2 clearly enhanced protein levels of E-cadherin and reduced levels of N-cadherin, Vimentin and matrix metalloproteinase-9 in Calu-3 cells, whereas overexpression of STRIP2 had the opposite effect in SPC-A1 cells. Our data indicate that STRIP2 promotes the proliferation and motility of LUAD cells, and this may be mediated through the regulation of the Akt/mTOR pathway and epithelial-mesenchymal transition. These results may facilitate the development of therapeutic strategies to treat LUAD.

Vincristine, carboplatin and cisplatin increase oxidative burst induced by PAF in canine neutrophils

Myelosupression resulting from chemotherapy has been widely described in veterinary medicine; however, there is limited information relating to alterations in neutrophil function after chemotherapy in dogs with cancer. The aim of this study was to determine the non-proliferative effects of vincristine, carboplatin, and cisplatin on canine neutrophils by evaluating activation of oxidative and non-oxidative responses. Neutrophils were isolated from venous blood. Levels of reactive oxygen species (ROS) and metalloproteinase 9 (MMP-9) were measured in vitro during neutrophil exposure to these chemotherapeutic agents for 15 min followed by stimulation with platelet activating factor (PAF). ROS production was detected via luminescence, and MMP- 9 liberation was determined by zymography. The chemotherapeutic agents caused an increase in PAF-induced ROS production, but no change in the non-oxidative response was observed. These results suggest that these chemotherapeutic agents may act as priming agents by increasing the oxidative response. These effects could be beneficial for dogs with cancer by supporting their immune systems; however, excessive ROS liberation has been associated with inflammation, neutrophil-mediated cell injury, carcinogenesis, and metastasis. Clinical studies are necessary to evaluate the significance of these findings.

MPPa-PDT suppresses breast tumor migration/invasion by inhibiting Akt-NF-κB-dependent MMP-9 expression via ROS

Background

Breast cancer is one of the most commonly diagnosed cancers in women, with high morbidity and mortality. Tumor metastasis is implicated in most breast cancer deaths; thus, inhibiting metastasis may provide a therapeutic direction for breast cancer. In the present study, pyropheophorbide-α methyl ester-mediated photodynamic therapy (MPPa-PDT) was used to inhibit metastasis in MCF-7 breast cancer cells.

Methods

Uptake of MPPa was detected by fluorescence microscopy. Cell viability was evaluated by the Cell Counting Kit-8 (CCK-8). ROS generation was detected by 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA). The migration of cells was assessed by wound healing assay, and invasion ability was assessed by Matrigel invasion assay. Levels of MMP2 and MMP9 were measured by PCR. Akt, phospho-Akt (Ser473), phospho-NF-κB p65 (Ser536) and NF-κB p65 were measured by western blotting. The F-actin cytoskeleton was observed by immunofluorescence. Lung tissue was visualized by hematoxylin and eosin staining.

Results

Following MPPa-PDT, migration and invasion were decreased in the MCF-7 cells. MPPa-PDT downregulated the expression of MMP2 and MMP9, which are responsible for the initiation of metastasis. MPPa-PDT reduced the phosphorylation of Akt and NF-κB. MPPa-PDT also reduced the expression of F-actin in cytoskeleton in MCF-7 cells. These effects were blocked by the reactive oxygen species scavenger NAC or the Akt activator SC79, while the PI3K inhibitor LY294002 or the Akt inhibitor triciribine enhanced these effects. Moreover, MPPa-PDT inhibited tumor metastasis and destroyed F-actin in vivo.

Conclusion

Taken together, these results demonstrate that MPPa-PDT inhibits the metastasis of MCF-7 cells both in vitro and in vivo and may be involved in the Akt/NF-κB-dependent MMP-9 signaling pathway. Thus, MPPa-PDT may be a promising treatment to inhibit metastasis.

Silibinin inhibits migration and invasion of breast cancer MDA-MB-231 cells through induction of mitochondrial fusion

Human triple negative breast cancer cells, MDA-MB-231, show typical epithelial to mesenchymal transition associated with cancer progression. Mitochondria play a major role in cancer progression, including metastasis. Changes in mitochondrial architecture affect cellular migration, autophagy and apoptosis. Silibinin is reported to have anti-breast cancer effect. We here report that silibinin at lower concentrations (30-90 μM) inhibits epithelial to mesenchymal transition (EMT) of MDA-MB-231, by increasing the expression of epithelial marker, E-cadherin, and decreasing the expression of mesenchymal markers, N-cadherin and vimentin. Besides, silibinin inhibition of cell migration is associated with reduction in the protein expression of matrix metalloproteinases 2 and 9 (MMP2 and MMP9) and paxillin. In addition, silibinin treatment increases mitochondrial fusion through down-regulating the expression of mitochondrial fission-associated protein dynamin-related protein 1 (DRP1) and up-regulating the expression of mitochondrial fusion-associated proteins, optic atrophy 1, mitofusin 1 and mitofusin 2. Silibinin perturbed mitochondrial biogenesis via down-regulating the levels of mitochondrial biogenesis regulators including mitochondrial transcription factor A (TFAM), peroxisome proliferator-activated receptor gamma coactivator (PGC1) and nuclear respiratory factor (NRF2). Moreover, DRP1 knockdown or silibinin inhibited cell migration, and MFN1&2 knockdown restored it. Mitochondrial fusion contributes to silibinin's negative effect on cell migration. Silibinin decreased reactive oxygen species (ROS) generation, leading to inhibition of the NLRP3 inflammasome activation. In addition, knockdown of mitofusin 1&2 (MFN 1&2) relieved silibinin-induced inhibition of NLRP3 inflammasome activation. Repression of ROS contributes to the inhibition of the expression of NLRP3, caspase-1 and IL-β proteins as well as of cell migration. Taken together, our study provides evidence that silibinin impairs mitochondrial dynamics and biogenesis, resulting in reduced migration and invasion of the MDA-MB-231 breast cancer cells.

Polyphyllin VI, a saponin from Trillium tschonoskii Maxim. induces apoptotic and autophagic cell death via the ROS triggered mTOR signaling pathway in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancers. Our previous studies have proven that Trillium tschonoskii Maxim. (TTM), a traditional Chinese medicine, possesses potent anti-tumor effect. However, the detailed components and molecular mechanism of TTM in anti-NSCLC are still unknown. In the present experiment, polyphyllin VI (PPVI) was successfully isolated from TTM with guidance of the anti-proliferative effect in A549 cells, and the cell death of PPVI treated A549 and H1299 cells was closely linked with the increased intracellular ROS levels. In addition, PPVI induced apoptosis by promoting the protein expression of Bax/Bcl2, caspase-3 and caspase-9, and activated autophagy by improving LC3 II conversion and GFP-LC3 puncta formation in A549 and H1299 cells. The mechanism study found that the activity of mTOR which regulates cell growth, proliferation and autophagy was significantly suppressed by PPVI. Accordingly, the PI3K/AKT and MEK/ERK pathways positively regulating mTOR were inhibited, and AMPK negatively regulating mTOR was activated. In addition, the downstream of mTOR, ULK1 at Ser 757 which downregulates autophagy was inhibited by PPVI. The apoptotic cell death induced by PPVI was confirmed, and it was significantly suppressed by the overexpression of AKT, ERK and mTOR, and the induced autophagic cell death which was depended on the Atg7 was decreased by the inhibitors, such as LY294002 (LY), Bafilomycin A1 (Baf), Compound C (CC) and SBI-0206965 (SBI). Furthermore, the mTOR signaling pathway was regulated by the increased ROS as the initial signal in A549 and H1299 cells. Finally, the anti-tumor growth activity of PPVI in vivo was validated in A549 bearing athymic nude mice. Taken together, our data have firstly demonstrated that PPVI is the main component in TTM that exerts the anti-proliferative effect by inducing apoptotic and autophagic cell death in NSCLC via the ROS-triggered mTOR signaling pathway, and PPVI may be a promising candidate for the treatment of NSCLC in future.

WFDC2 contributes to epithelial-mesenchymal transition (EMT) by activating AKT signaling pathway and regulating MMP-2 expression

Objective: To understand the role of WFDC2 in metastasis of ovarian cancer. Methods: By knockdown or overexpression of WFDC2, we demonstrated the role of WFDC2 in epithelial-mesenchymal transition (EMT). Results: We demonstrated that stable knockdown of WFDC2 suppressed EMT along with the upregulation of E-cadherin and the downregulation of Vimentin. In addition, WFDC2 knockdown decreases matrix metalloproteinase-2 (MMP-2) expression in in vitro cell model and in in vivo nude mice xenografts. The correlation of WFDC2 and MMP-2 expression in the clinical sample confirmed that WFDC2 was tightly correlated with the development of tumor. More importantly, the EMT phenotype and cell invasion induced by WFDC2 overexpressing can be reversed by the siMMP-2 and P13K/AKT signaling inhibitor. Conclusion: WFDC2 contributed to ovarian cancer metastasis and EMT as a positive regulator by activating AKT signaling pathway and inducing MMP-2 expression.

Evaluation for Synergistic Effects by Combinations of Photodynamic Therapy (PDT) with Temoporfin (mTHPC) and Pt(II) Complexes Carboplatin, Cisplatin or Oxaliplatin in a Set of Five Human Cancer Cell Lines

The platinum(II) complexes carboplatin (CBDCA), cisplatin (CDDP) and oxaliplatin (1-OHP) are used as anticancer drugs in a large number of tumour chemotherapy regimens. Many attempts have been made to combine Pt(II)-based chemotherapy with alternative treatment strategies. One such alternative anticancer approach is known as photodynamic therapy (PDT), where a non-toxic photosensitizer (PS) produces oxidative stress via the formation of reactive oxygen species (ROS) after local illumination of the affected tissue. A very promising PS is 5,10,15,20-tetra(m-hydroxyphenyl)chlorin (mTHPC, Temoporfin), which is approved for the treatment of head and neck cancer in Europe. In the present study, a combination of mTHPC-mediated PDT and either CBDCA, CDDP, or 1-OHP was applied to five human cancer cell lines from different tumour origins. Cytotoxicity was determined by the MTT assay and synergistic effects on cytotoxicity were evaluated by calculation of Combination Indices (CI). Synergy was identified in some of the combinations, for example, with 1-OHP in three of the tested cell lines but antagonism was also observed for a number of combinations in certain cell lines. In cases of synergy, elevated ROS levels were observed after combination but apoptosis induction was not necessarily increased compared to a treatment with a single compound. Cell cycle analysis revealed a formation of apoptotic subG1 populations and S phase as well as G2/M phase arrests after combination. In conclusion, pre-treatment with mTHPC-PDT has the potential to sensitize some types of tumour cells towards Pt(II) complexes, in particular 1-OHP but synergy is highly dependent on the type of cancer.

LncRNA SNHG5 promotes the progression of osteosarcoma by sponging the miR-212-3p/SGK3 axis

Background

Long non-coding RNA (lncRNA) SNHG5 has been found to play an important role in tumors. Nevertheless, the function and mechanism of lncRNA SNHG5 in osteosarcoma (OS) remains unclear. The purpose of this study was to investigate whether lncRNA SNHG5 can regulate the occurrence and development of OS cells.

Methods

We performed quantitative real time PCR to detect the expression of lncRNA SNHG5 in OS cells. 143B, MG63 (knockdown) and U2OS, U2R (overexpression) cell lines were chosen for the function study of SNHG5. The effect of SNHG5, miR-212-3p, and SGK3 in OS cells was explored by MTT assays, clony formation, flow cytometry, transwell assays, wound healing assays, and cell spreading assays. Quantitative real-time PCR, Western blot analysis and luciferase assays were used to detect the interaction between lncRNA SNHG5 and miR-212-3p.

Results

In this study, knockdown of lncRNA SNHG5 suppressed the growth and metastasis of OS cells, whereas the overexpression of SNHG5 produced an opposite result. Mechanistically, lncRNA SNHG5 functions as a sponger against miR-212-3p and suppresses the miR-212-3p/SGK3 signaling pathway. Introduction of miR-212-3p mimics or inhibitors reverses SNHG5 overexpression or silences the exerted tumor promoting or suppressing effect. In addition, our results showed that the function of SNHG5 can be rescued by miR-212-3p and can regulate the growth and metastasis of OS cells via SGK3, the downstream target of miR-212-3p.

Conclusions

In summary, our study demonstrated that lncRNA SNHG5 can regulate the proliferation and metastasis of OS cells through the miR-212-3p/SGK3 axis. This axis may provide a new target for future clinical treatment.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0641-9) contains supplementary material, which is available to authorized users.

Perfluorooctanoic acid stimulates ovarian cancer cell migration, invasion via ERK/NF-κB/MMP-2/-9 pathway

As widely used in consumer products, perfluorooctanoic acid (PFOA) has become a common environmental pollutant, which has been detected in human serum and associated with cancers. Our previous study showed that PFOA is a carcinogen that promotes endometrial cancer cell migration and invasion through activation of ERK/mTOR signaling. Here, we showed that PFOA (≥100 nM) treatment also stimulated A2780 ovarian cancer cell invasion and migration, which correlated with increased matrix metalloproteinases MMP-2/-9 expression, important proteases associated with tumor invasion and migration. Notably, PFOA treatment induced activation of ERK1/2/ NF-κB signaling. Pre-treatment with U0126, an ERK1/2inhibitor；or JSH-23, a NF-kB inhibitor, can reverse the PFOA-induced cell migration and invasion. Consistent with these results, inhibiting ERK1/2 or NF-κB signaling abolished PFOA-induced up-regulation of MMP-2/-9 expression. These results indicate that PFOA can stimulate ovarian cancer cell migration, invasion and MMP-2/-9 expression by up-regulating ERK/NF-κB pathway.

Plasma-derived Exosomes Reverse Epithelial-to-Mesenchymal Transition after Photodynamic Therapy of Patients with Head and Neck Cancer

Photodynamic therapy (PDT) is a palliative treatment option for head and neck squamous cell carcinoma (HNSCC) patients which induces local inflammation and alters tumor cell morphology. We show that exosomes in plasma of HNSCC patients undergoing PDT reprogram tumor cells towards an epithelial phenotype. Nine HNSCC patients were treated with PDT and plasma was collected prior to and at three timepoints after therapy. Exosome levels of E-Cadherin, N-Cadherin and TGF-β1 were tested by flow cytometry. Exosomes were co-incubated with cancer cells, and changes in expression of EMT markers were evaluated as were proliferation, migration, chemotaxis and invasiveness of tumor cells. Exosomes harvested pre- and 24h after PDT were enriched in N-Cadherin and TGF-β1. They induced the mesenchymal phenotype and up-regulated Vimentin and transcripts for Snail, Twist, α-SMA, Slug and ZEB1 in epithelial tumor cells. These exosomes also enhanced tumor proliferation, migration and invasion. In contrast, exosomes obtained on day 7 or 4-6 weeks after PDT carried E-cadherin, restored epithelial morphology and EpCAM expression in tumor cells, down-regulated expression of mesenchymal genes and inhibited proliferation, migration and invasion. The PDT-mediated conversion from the mesenchymal to epithelial tumor phenotype was mediated by exosomes, which also served as non-invasive biomarkers of this transition.

Upregulated N-cadherin expression is associated with poor prognosis in epithelial-derived solid tumours: A meta-analysis

BACKGROUND

N-cadherin is an important molecular in epithelial-mesenchymal transition (EMT) and has been reported to be associated with aggressive behaviours of tumours. However, prognostic value of N-cadherin in solid malignancies remains controversially.

MATERIALS AND METHODS

The Pubmed/MELINE and EMBASE databases were used for a comprehensive literature searching. Pooled risk ratio (RR) and hazard ratio (HR) with their corresponding 95% confidence intervals (CIs) were employed to quantify the prognostic role.

RESULTS

Involving 36 studies with 5705 patients were performed to investigate relationships between N-cadherin upregulation and clinicopathological features, survival. Results suggested upregulated N-cadherin was associated with lymph node metastasis (RR = 1.16, 95% CI [1.00, 1.35]), higher histological grade (RR = 1.36, 95%CI [1.14, 1.62]), angiolymphatic invasion (RR = 1.19, 95% CI [1.06, 1.34]) and advanced clinical stage (RR = 1.32, 95% CI [1.06, 1.64]), while upregulated N-cadherin was apt to be associated with distant metastasis (RR = 1.43, 95% CI [0.99, 2.05]). Moreover, N-cadherin was correlated with poor prognosis of 3-year survival (HR = 1.78, 95% CI [1.51, 2.10]), 5-year survival (HR = 1.57, 95% CI [1.17, 2.10]) and overall survival (OS) (HR = 1.32, 95% CI [1.20, 1.44]). Subgroup analyses according to cancer types were also conducted for applying these conclusions to some tumours more properly. No publication bias was found except subgroup analysis of distant metastasis (P = .652 for Begg's test and 0.023 for Egger's test).

CONCLUSIONS

Taken together, upregulation of N-cadherin is associated with more aggressive behaviours of epithelial-derived solid malignancies and can be regarded as a predictor of poor survival.

Knockdown of Snail inhibits epithelial-mesenchymal transition of human laryngeal squamous cell carcinoma Hep-2 cells through the vitamin D receptor signaling pathway

It has been well documented that Snail plays a decisive role in various tumors. However, the direct effect of Snail on laryngeal squamous cell carcinoma (LSCC) has not been elaborated. In this study, we firstly detected the expression of Snail in 14 samples of patients with LSCC and found that its content was high in cancer tissues compared with adjacent tissues. Then we established LSCC Hep-2 cells with Snail silencing and validated the knockdown efficiency by Western blotting and real-time PCR. Results showed that silencing of Snail significantly inhibited the ability of adhesion, migration, and invasion of Hep-2 cells. Further study revealed that knockdown of Snail suppressed the epithelial-mesenchymal transition (EMT) process of Hep-2 cells, as evidenced by downregulation of matrix metallopeptidase (MMP)-2, MMP-9, integrin subunit beta 1 (ITGβ1), β-catenin, vimentin, N-cadherin, and fibronectin and upregulation of vitamin D receptor (VDR) and E-cadherin. Additionally, transfection with the small interfering RNA of VDR reversed the effect induced by Snail silencing in Hep-2 cells. Taken together, these results demonstrate that knockdown of Snail can inhibit the EMT process of LSCC cells through the VDR signaling pathway in vitro.

Bradykinin Promotes Cell Proliferation, Migration, Invasion, and Tumor Growth of Gastric Cancer Through ERK Signaling Pathway

Bradykinin (BK) has been reported to be involved in the progression of diverse types of cancer. In the present study, we investigated the possible role of BK in cell proliferation, migration, invasion, and tumor growth of gastric cancer (GC). Cell proliferation was evaluated by MTT assays. Cell migration and invasion were assessed by Transwell assays. Tumor growth of nude mice was detected by establishing subcutaneous xenograft tumor model. Silencing of bradykinin B1 receptor (B1R) and the bradykinin B2 receptor (B2R) was performed by transfecting cells with si-B1R and si-B2R, respectively. The protein expression levels of phospho-ERK1/2 (p-ERK1/2), matrix metalloproteinase (MMP)-2, MMP-9, and E-Cadherin were examined by Western blot. Data revealed that BK promoted cell proliferation, migration, invasion, and the in vivo tumor growth of GC cells SGC-7901 and HGC-27. Furthermore, BK elevated the protein levels of p-ERK1/2, MMP-2, and MMP-9, but reduced E-Cadherin. In addition, by repressing B2R using si-B2R or inhibiting ERK signaling pathway using PD98059, BK-mediated promotion of cell proliferation, migration, and invasion and upregulation of p-ERK1/2, MMP-2/9, as well as downregulation of E-Cadherin were attenuated. Taken together, the present study demonstrated that BK promoted cell proliferation, migration, invasion, and tumor growth by binding to B2R via ERK signaling pathway. Our findings may provide promising options for the further treatment of GC. J. Cell. Biochem. 118: 4444-4453, 2017. © 2017 Wiley Periodicals, Inc.

CBX7 negatively regulates migration and invasion in glioma via Wnt/β-catenin pathway inactivation

CBX7, a member of the Polycomb-group proteins, plays a significant role in normal and cancerous tissues and has been defined as a tumor suppressor in thyroid, breast and pancreatic cancers. However, its function in glioma remains undefined. CBX7 expression is decreased in glioma, especially in higher grade cases, according to data in the CGGA, GSE16001 and TCGA databases. Further experimental evidence has shown that exogenous CBX7 overexpression induced apoptosis and inhibited cell proliferation, colony formation and migration of glioma cells. In this study, we show that the invasive ability of glioma cells was decreased following CBX7 overexpression and CBX7 overexpression was associated with Wnt/β-catenin pathway inhibition, which also decreased downstream expression of ZEB1, a core epithelial-to-mesenchymal transition factor. This reduction in Wnt signaling is controlled by DKK1, a specific Wnt/β-catenin inhibitor. CBX7 enhances DKK1 expression by binding the DKK1 promoter, as shown in Luciferase reporter assays. Our data confirm that CBX7 inhibits EMT and invasion in glioma, which is manifested by influencing the expression of MMP2, MMP9, E-cadherin, N-cadherin and Vimentin in LN229, T98G cells and primary glioma cells (PGC). Furthermore, as a tumor suppressor, CBX7 expression is pivotal to reduce tumor invasion and evaluate prognosis.

KIAA1199 promotes migration and invasion by Wnt/β-catenin pathway and MMPs mediated EMT progression and serves as a poor prognosis marker in gastric cancer

BACKGROUND

KIAA1199 was upregulated in diverse cancers, but the association of KIAA1199 with gastric cancer (GC), the biological role of KIAA1199 in GC cells and the related molecular mechanisms remain to be elucidated.

METHODS

KIAA1199 expression was analysed by reverse transcription-polymerase chain reaction assay (RT-PCR) and immunohistochemistry (IHC) in GC patient tissue. The small hairpin RNA (shRNA) was applied for the knockdown of endogenous KIAA1199 in NCI-N87 and AGS cells. MTT, colony formation, scratch wounding migration, transwell chamber migration and invasion assays were employed respectively to investigate the role of KIAA1199 in GC cells. The potential signaling pathway of KIAA1199 induced migration and invasion was detected.

RESULTS

KIAA1199 was upregulated in GC tissue and was an essential independent marker for poor prognosis. Knockdown KIAA1199 suppressed the proliferation, migration and invasion in GC cells. KIAA1199 stimulated the Wnt/β-catenin signaling pathway and the enzymatic activity of matrix metalloproteinase (MMP) family members and thus accelerated the epithelial-to-mesenchymal transition (EMT) progression in GC cells.

CONCLUSION

These findings demonstrated that KIAA1199 was upregulated in GC tissue and associated with worse clinical outcomes in GC, and KIAA1199 acted as an oncogene by promoting migration and invasion through the enhancement of Wnt/β-catenin signaling pathway and MMPs mediated EMT progression in GC cells.