Epithelial-mesenchymal Transition In Lung Cancer Cells Research Articles

Inhibition of proteinase-activated receptor 2 (PAR2) decreased the malignant progression of lung cancer cells and increased the sensitivity to chemotherapy

ObjectivesThis study aimed to study the effect of protease-activated receptor 2 (PAR2) on the proliferation, invasion, and clone formation of lung cancer cells. It also aimed to evaluate the inhibitory effect of melittin on PAR2 and the anti-lung cancer effect of melittin combined with gefitinib.MethodsThe correlation between the co-expression of PAR2 and epithelial–mesenchymal transition (EMT) markers was analyzed. PAR2 in A549 and NCI-H1299 cells was knocked down using siRNA. MTT assay, Transwell assay, and colony formation assay were used to detect the effects of PAR2 on cell proliferation, invasion, and clone formation. The anti-cancer effect of PAR2 knockdown on gefitinib treatment was analyzed. The synergistic effect of melittin on gefitinib treatment by inhibiting PAR2 and the underlying molecular mechanism were further analyzed and tested.ResultsThe expression of PAR2 was upregulated in lung cancer, which was associated with the poor prognosis of lung cancer. PAR2 knockdown inhibited the stemness and EMT of lung cancer cells. It also inhibited the proliferation, invasion, and colony formation of A549 and NCI-H1299 cells. Moreover, PAR2 knockdown increased the chemotherapeutic sensitivity of gefitinib in lung cancer. Melittin inhibited PAR2 and the malignant progression of lung cancer cells. Melittin increased the chemotherapeutic sensitivity of gefitinib in lung cancer by inhibiting PAR2.ConclusionPAR2 may promote the proliferation, invasion, and colony formation of lung cancer cells by promoting EMT. Patients with a high expression of PAR2 have a poor prognosis. Inhibition of PAR2 increased the chemotherapeutic sensitivity of gefitinib. PAR2 may be a potential therapeutic target and diagnostic marker for lung cancer.

PLEK2 mediates metastasis and invasion via α5-nAChR activation in nicotine-induced lung adenocarcinoma.

Evidence has shown a strong relationship between smoking and epithelial mesenchymal transition (EMT). α5-nicotinic acetylcholine receptor (α5-nAChR) contributes to nicotine-induced lung cancer cell EMT. The cytoskeleton-associated protein PLEK2 is mainly involved in cytoskeletal protein recombination and cell stretch migration regulation, which is closely related to EMT. However, little is known about the link between nicotine/α5-nAChR and PLEK2 in lung adenocarcinoma (LUAD). Here, we identified a link between α5-nAChR and PLEK2 in LUAD. α5-nAChR expression was correlated with PLEK2 expression, smoking status and lower survival in vivo. α5-nAChR mediated nicotine-induced PLEK2 expression via STAT3. α5-nAChR/PLEK2 signaling is involved in LUAD cell migration, invasion and stemness. Moreover, PLEK2 was found to interact with CFL1 in nicotine-induced EMT in LUAD cells. Furthermore, the functional link among α5-nAChR, PLEK2 and CFL1 was confirmed in mouse xenograft tissues and human LUAD tissues. These findings reveal a novel α5-nAChR/PLEK2/CFL1 pathway involved in nicotine-induced LUAD progression.

(−)-Guaiol inhibit epithelial-mesenchymal transition in lung cancer via suppressing M2 macrophages mediated STAT3 signaling pathway

In the context of cancer expansion, epithelial-mesenchymal transition (EMT) plays an essential role in driving invasion and metastasis potential of cancer cells. Tumor-associated macrophages (TAMs)-derived factors involved in the initiation and progression of EMT. We assess the role of M2 macrophage in suppressing lung tumors of a natural compound (−)-Guaiol by using macrophage depleted model. Bone marrow-derived monocytes (BMDMs) were extracted and induced to M2-like phenotype in vitro. The co-culture of M2 macrophage and lung cancer cells was established to observe that inhibition of lung tumor growth by (−)-Guaiol requires presence of macrophages. This suppressed effect of (−)-Guaiol was alleviated when mice macrophage was depleted. The expression of M2-like macrophages was strongly reduced by (−)-Guaiol treated mice, but not the changes of M1-like macrophages. In vitro studies, we demonstrated that (−)-Guaiol suppressed M2 polarization of BMDMs, as well as migration, invasion, and EMT of lung cancer cells in co-culture. M2 macrophage-derived interleukin 10 (IL-10) was investigated as a critical signaling molecule between M2 macrophage and lung cancer cells. We have also verified that the mechanism of (−)-Guaiol inhibiting the EMT process of lung cancer is related to the activation of IL-10-mediated signal transducer and activator of transcription 3 (STAT3). These results suggested that the suppressive effect role of (−)-Guaiol in M2 macrophage promoting EMT of lung cancer, which was associated with inhibition of IL-10 mediated STAT3 signaling pathway.

Abstract 1224: Quaking overexpression downregulates epithelial-mesenchymal transition in lung cancer cells

Abstract Background: Lung cancer is the leading cause of cancer death worldwide. Tumor recurrence is the most common cause of treatment failure after surgical resection. Quaking (QKI) is a functional protein that mediate alternative splicing, which belongs to the STAR family of the KH domain, containing RNA binding proteins. QKI regulate various genes via alternative splicing and circRNA formation during epithelial-mesenchymal transition (EMT). QKI takes an important part in tumorigenesis. QKI has been reported to be associated with progression of human cancer. However, several studies have indicated that QKI was associated with repression of EMT. Furthermore, the prognostic value of QKI in lung cancer patients and its regulatory mechanisms in EMT in lung cancer cells remains unknown. Materials and Methods: A total of 79 patients with resected lung adenocarcinoma were included in the study. QKI expression was determined by immunohistochemistry in tumor specimens. The prognostic value of QKI overexpression and its relationship with clinicopathological variables were investigated. QKI knockdown was performed in H1299 and A549 cells. Western blotting analysis was performed to demonstrated QKI, E-cadherin and vimentin expression. Results: QKI overexpression was significantly associated with female gender (P = 0.045). There was no significant association between QKI overexpression and predominant pattern group (lepidic/acinar/papillary vs. micropapillary/solid) (P = 0.180). Univariate analysis indicated that predominant pattern group (lepidic/acinar/papillary vs. micropapillary/solid) (P = 0.006) was a significant prognostic factor for worse recurrence-free survival (RFS). QKI overexpression (P = 0.042) was a significant prognostic factor for better RFS. Increased vimentin expression and decreased E-cadherin expression were identified in H1299 and A549 cells after QKI knockdown. Conclusions: QKI overexpression has the potential to be a significant prognostic factor for better RFS in patients with resected lung adenocarcinoma. Increased vimentin expression and decreased E-cadherin expression were identified in H1299-QKIi cells. QKI may possess the ability to inhibit invasion and migration through repressing EMT. Citation Format: Ying-Shiun Kao, Jung-Jyh Hung. Quaking overexpression downregulates epithelial-mesenchymal transition in lung cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1224.

Ethacrynic acid suppresses B7-H4 expression involved in epithelial-mesenchymal transition of lung adenocarcinoma cells via inhibiting STAT3 pathway

Lung cancer is characterized by high incidence and mortality. 90% of cancer deaths are caused by metastases. The epithelial-mesenchymal transition (EMT) process in cancer cells is a prerequisite for the metastatic process. Ethacrynic acid (ECA) is a loop diuretic that inhibits the EMT process in lung cancer cells. EMT has been related to the tumour immunemicroenvironment. However, the effect of ECA on immune checkpoint molecules in the context of cancer has not been fully identified.In the present study, we found that sphingosylphosphorylcholine (SPC) and TGF-β1, awell-known EMT inducer, induced the expression of B7-H4 in lung cancer cells. We also investigated the involvement of B7-H4 in the SPC-induced EMT process. Knockdown of B7-H4 suppressed SPC-induced EMT, while B7-H4 overexpression enhanced EMT of lung cancer cells. ECA inhibited SPC/TGF-β1-induced B7-H4 expression via suppression of STAT3 activation. Moreover, ECA inhibits the colonization of mice lung by tail vein-injected LLC1 cells. ECA-treated mice increased the CD4-positive T cells in lung tumour tissues.In summary, these results suggested that ECA inhibits B7-H4 expression via STAT3 inhibition, leading to SPC/TGF-β1-induced EMT. Therefore, ECA might be an immune oncological drug for B7-H4-positive cancer, especially lung cancer.

Extracellular vesicles derived from lung cancer cells promote the progression of lung cancer by delivering miR-151a-5p

Extracellular vesicles (EVs) participate in the occurrence and development of lung cancer. MiR-151a-5p has been reported to be highly expressed in the tumor tissues of lung cancer. The aim of this work was to investigate whether EVs can affect lung cancer progression by delivering miR-151a-5p. In this work, we found that miR-151a-5p was highly expressed in serum of lung cancer patients. Up-regulation of miR-151a-5p and down-regulation of Nedd4-binding partner-1 (N4BP1) were observed in lung cancer cell lines. The expression of miR-151a-5p was also increased in H520-derived EVs. H520-derived EVs promoted cell proliferation, inhibited apoptosis of H520 cells by delivering miR-151a-5p. EVs containing miR-151a-5p repressed E-cadherin expression and elevated N-cadherin and Vimentin expression to impede epithelial-mesenchymal transition (EMT) of H520 cells. Additionally, the interaction between miR-151a-5p and N4BP1 was verified by luciferase reporter assay, showing that miR-151a-5p interacted with N4BP1. MiR-151a-5p repressed N4BP1 expression by interacting with N4BP1. EVs containing miR-151a-5p promoted malignant phenotypes of H520 cells by targeting N4BP1. Finally, a tumor-bearing mouse model was constructed by inoculation of H520 cells with miR-151a-5p overexpression or knockdown. Overexpression of miR-151a-5p accelerated tumor growth of lung cancer in vivo, and repressed N4BP1 expression in the tumor tissues. Knockdown of miR-151a-5p caused opposite results. In conclusion, this work demonstrated that lung cancer cell-derived EVs secreted miR-151a-5p to promote cell proliferation, and inhibit apoptosis and EMT of lung cancer cells by targeting N4BP1, thereby accelerating lung cancer progression. Thus, this study suggests that EVs-derived miR-151a-5p may be a potential target for lung cancer treatment.

The actin cytoskeleton: Morphological changes in pre- and fully developed lung cancer.

Actin, a primary component of the cell cytoskeleton can have multiple isoforms, each of which can have specific properties uniquely suited for their purpose. These monomers are then bound together to form polymeric filaments utilizing adenosine triphosphate hydrolysis as a source of energy. Proteins, such as Arp2/3, VASP, formin, profilin, and cofilin, serve important roles in the polymerization process. These filaments can further be linked to form stress fibers by proteins called actin-binding proteins, such as α-actinin, myosin, fascin, filamin, zyxin, and epsin. These stress fibers are responsible for mechanotransduction, maintaining cell shape, cell motility, and intracellular cargo transport. Cancer metastasis, specifically epithelial mesenchymal transition (EMT), which is one of the key steps of the process, is accompanied by the formation of thick stress fibers through the Rho-associated protein kinase, MAPK/ERK, and Wnt pathways. Recently, with the advent of "field cancerization," pre-malignant cells have also been demonstrated to possess stress fibers and related cytoskeletal features. Analytical methods ranging from western blot and RNA-sequencing to cryo-EM and fluorescent imaging have been employed to understand the structure and dynamics of actin and related proteins including polymerization/depolymerization. More recent methods involve quantifying properties of the actin cytoskeleton from fluorescent images and utilizing them to study biological processes, such as EMT. These image analysis approaches exploit the fact that filaments have a unique structure (curvilinear) compared to the noise or other artifacts to separate them. Line segments are extracted from these filament images that have assigned lengths and orientations. Coupling such methods with statistical analysis has resulted in development of a new reporter for EMT in lung cancer cells as well as their drug responses.

Mechanisms of Biochanin A Alleviating PM2.5 Organic Extracts-Induced EMT of A549 Cells through the PI3K/Akt Pathway.

Epithelial-mesenchymal transition (EMT) is an important step in tumor progression, which enables tumor cells to acquire migration and invasion characteristics. The aim of this study was to investigate the mechanism of biological biochanin A (BCA) in ameliorating fine particulate matter (PM2.5) lung injury. The results showed that PM2.5 could induce spindle-like changes in cell morphology, causing the ability of migration and invasion. However, they were significantly inhibited by BCA treatment (10/20/30 μm). After BCA treatment, the release and transcription of chemokine CXCL12 and its receptor gene CXCR4 were inhibited, and the release of growth inducer TGF-β1 was significantly reduced. In addition, BCA promoted the transcription of E-cadherin and β-catenin, inhibiting the expression of N-cadherin, vimentin, and fibronectin, and down-regulated the expression of MMP-2/9. We found that BCA effectively interfered with the PI3K/Akt signaling pathway activated by PM2.5. In conclusion, PM2.5 can induce EMT in lung cancer cells, and BCA may reverse this process by activating the PI3K/Akt signaling pathway.

M6A RNA methylation regulates the transcription factors JUN and JUNB in TGF-β-induced epithelial–mesenchymal transition of lung cancer cells

N6-methyladenosine (m6A) is the most common internal chemical modification of mRNAs involved in many pathological processes including various cancers. In this study, we investigated the m6A-dependent regulation of JUN and JUNB transcription factors (TFs) during transforming growth factor-beta-induced epithelial-mesenchymal transition (EMT) of A549 and LC2/ad lung cancer cell lines, as the function and regulation of these TFs within this process remains to be clarified. We found that JUN and JUNB played an important and nonredundant role in the EMT-inducing gene expression program by regulating different mesenchymal genes and that their expressions were controlled by methyltransferase-like 3 (METTL3) m6A methyltransferase. METTL3-mediated regulation of JUN expression is associated with the translation process of JUN protein but not with the stability of JUN protein or mRNA, which is in contrast with the result of m6A-mediated regulation of JUNB mRNA stability. We identified the specific m6A motifs responsible for the regulation of JUN and JUNB in EMT within 3'UTR of JUN and JUNB. Furthermore, we discovered that different m6A reader proteins interacted with JUN and JUNB mRNA and controlled m6A-dependent expression of JUN protein and JUNB mRNA. These results demonstrate that the different modes of m6A-mediated regulation of JUN and JUNB TFs provide critical input in the gene regulatory network during transforming growth factor-beta-induced EMT of lung cancer cells.

MFAP2 contributes to the proliferation and motility of lung cancer cells via Wnt/β-catenin pathway

Purpose: To measure microfibrillar-associated protein 2 (MFAP2) expression levels in lung cancer and identify its role in lung cancer.Methods: Immunoblots and PCR were used to determine the expression of MFAP2 in lung cancer cell lines. The effects of MFAP2 on the viability and apoptosis of lung cancer cells were evaluated by CCK-8, colony formation, and flow cytometry (FCM) assays, while wound healing and Transwell assays were used to assess the effects of MFAP2 on the motility and epithelial-mesenchymal transition (EMT) of lung cancer cells. Immunoblot assays were also performed to determine the effect of MFAP2 on the Wnt/β-catenin axis in lung cancer cells.Results: MFAP2 was highly expressed in lung cancer cells. Depletion of MFAP2 suppressed the viability and stimulated apoptosis in these cells (p < 0.01). In addition, knockdown of MFAP2 suppressed the motility and EMT of lung cancer cells (p < 0.01). MFAP2 mediated the Wnt/β-catenin axis and affected the viability and motility of lung cancer cells.Conclusion: MFAP2 is a promising target for lung cancer treatment.

Comprehensive Analysis of hsa-miR-654-5p’s Tumor-Suppressing Functions

The pivotal roles of miRNAs in carcinogenesis, metastasis, and prognosis have been demonstrated recently in various cancers. This study intended to investigate the specific roles of hsa-miR-654-5p in lung cancer, which is, in general, rarely discussed. A series of closed-loop bioinformatic functional analyses were integrated with in vitro experimental validation to explore the overall biological functions and pan-cancer regulation pattern of miR-654-5p. We found that miR-654-5p abundance was significantly elevated in LUAD tissues and correlated with patients’ survival. A total of 275 potential targets of miR-654-5p were then identified and the miR-654-5p-RNF8 regulation axis was validated in vitro as a proof of concept. Furthermore, we revealed the tumor-suppressing roles of miR-654-5p and demonstrated that miR-654-5p inhibited the lung cancer cell epithelial-mesenchymal transition (EMT) process, cell proliferation, and migration using target-based, abundance-based, and ssGSEA-based bioinformatic methods and in vitro validation. Following the construction of a protein–protein interaction network, 11 highly interconnected hub genes were identified and a five-genes risk scoring model was developed to assess their potential prognostic ability. Our study does not only provide a basic miRNA-mRNA-phenotypes reference map for understanding the function of miR-654-5p in different cancers but also reveals the tumor-suppressing roles and prognostic values of miR-654-5p.

The TCM Prescription Yi-Fei-Jie-Du-Tang Inhibit Invasive Migration and EMT of Lung Cancer Cells by Activating Autophagy.

Yi-Fei-Jie-Du-Tang (YFJDT) is a traditional Chinese medicine formulation. Our previous studies have demonstrated that YFJDT can be used to treat non-small-cell lung cancer (NSCLC), but its protective effect against NSCLC and its mechanisms remain unclear. In the present study, we evaluated the protective effects and potential mechanisms of YFJDT on a tumor-bearing mouse lung cancer model and A549 cell model. Tumor-bearing mice and A549 cells were treated with YFJDT, tumors were measured during the experiment, and tumor tissues and cell supernatants were collected at the end of the experiment to assess the levels of autophagy and epithelial-mesenchymal transition (EMT)-related proteins. The results showed that YFJDT treatment reduced tumor volume and mass, increased the expression of the autophagy marker LC3, and inhibited EMT-related proteins compared with the model group. Cell survival was reduced in the YFJDT-treated groups compared with the model group, and YFJDT also reduced the migration and invasion ability of A549 cells in a dose-dependent manner. Western blotting detected that YFJDT also upregulated FAT4 in the tumor tissue and A549 cells and downregulated the expression of vimentin. Meanwhile, apoptosis in both tissues and cells was greatly increased with treatment of YFJDT. We further interfered with FAT4 expression in cells and found that the inhibitory effect of YFJDT on EMT was reversed, indicating that YFJDT affects EMT by regulating FAT4 expression. Taken together, results of this study suggested that the inhibitory effect of YFJDT on EMT in lung cancer tumors is through upregulating FAT4, promoting autophagy, and thus inhibiting EMT in cancer cells.

MicroRNA-889-3p restrains the proliferation and epithelial–mesenchymal transformation of lung cancer cells via down-regulation of Homeodomain-interacting protein kinase 1

ABSTRACT Dysregulated microRNAs (miRNAs) are common in human cancers and are involved in the proliferation, promotion, and metastasis of tumor cells. Therefore, the aim of this study was to evaluate the expression and biological function of miR-889-3p in lung cancer (LC). MiR-889-3p and Homeodomain-interacting protein kinase 1 (HIPK1) expression was detected in human LC tissues and cells. The correlation of miR-889-3p with the clinicopathology of LC patients was observed. After the transfection of miR-889-3p and HIPK1-related plasmids in human LC cell line A549, several studies were employed for detection of cell growth. In addition, the targeting of miR-889-3p with HIPK1 was verified. The results clarified miR-889-3p was down-regulated, while HIPK1 was up-regulated in LC tissues. Elevated miR-889-3p or repressed HIPK1 weakened the viability, epithelial–mesenchymal transition (EMT), invasion, migration of LC cells, whereas strengthened apoptosis. MiR-889-3p targeted HIPK1; MiR-889-3p mediated HIPK1 to affect the proliferation and EMT of LC cells. Therefore, it is concluded that miR-889-3p repressing HIPK1 restrains the proliferation and EMT of LC cells, providing a novel target for LC therapy.

Nannocystin Ax, a natural elongation factor 1α inhibitor from Nannocystis sp., suppresses epithelial-mesenchymal transition, adhesion and migration in lung cancer cells

Epithelial-mesenchymal transition (EMT), the epithelial cells transdifferentiation into the mesenchymal cells, has been involved in cancer metastasis. Nannocystin ax (NAN) is a cyclodepsipeptide initially isolated from Myxobacterial genus, Nannocystis sp. with anticancer activities. This study was designed to explore the effect of NAN on TGF-β1-induced EMT in lung cancer cells. The morphological alteration was observed with a microscope. Western blotting and immunofluorescence assays were used to detect the protein expression and the localization. The adhesion and migration were evaluated by adhesion assay and wound healing assay. The mRNA expression of TGF-β receptor type I (TβRI) was determined by real-time PCR. NAN significantly restrained TGF-β1-induced EMT morphological changes, the protein expression of E-cadherin, N-cadherin, and Vimentin, etc. TGF-β1 activated phosphorylation and nuclear translocation of Smad2/3 were inhibited by NAN. Furthermore, NAN suppressed adhesion and migration triggered by TGF-β1. In addition, NAN significantly down-regulated TβRI on the transcriptional level directly. In summary, these results showed that NAN restrained TGF-β1-induced epithelial-mesenchymal transition, migration, and adhesion in human lung cancer cells. The underlying mechanism involved the inhibition of Smad2/3 and the TβRI signaling pathway. This study reveals the new anticancer effect and mechanism of NAN.

Functional antagonism of chromatin modulators regulates epithelial-mesenchymal transition.

Epithelial-mesenchymal transition (EMT) is a developmental process hijacked by cancer cells to modulate proliferation, migration, and stress response. Whereas kinase signaling is believed to be an EMT driver, the molecular mechanisms underlying epithelial-mesenchymal interconversion are incompletely understood. Here, we show that the impact of chromatin regulators on EMT interconversion is broader than that of kinases. By combining pharmacological modulation of EMT, synthetic genetic tracing, and CRISPR interference screens, we uncovered a minority of kinases and several chromatin remodelers, writers, and readers governing homeostatic EMT in lung cancer cells. Loss of ARID1A, DOT1L, BRD2, and ZMYND8 had nondeterministic and sometimes opposite consequences on epithelial-mesenchymal interconversion. Together with RNAPII and AP-1, these antagonistic gatekeepers control chromatin of active enhancers, including pan-cancer-EMT signature genes enabling supraclassification of anatomically diverse tumors. Thus, our data uncover general principles underlying transcriptional control of cancer cell plasticity and offer a platform to systematically explore chromatin regulators in tumor-state-specific therapy.

Toxicarioside O Inhibits Cell Proliferation and Epithelial-Mesenchymal Transition by Downregulation of Trop2 in Lung Cancer Cells.

Toxicarioside O (TCO), a natural product derived from Antiaris toxicaria, has been identified to be a promising anticancer agent. In this study, we aimed to investigate the effect of TCO on the proliferation and epithelial-mesenchymal transition (EMT) of lung cancer cells and its molecular mechanisms. Here, we indicated that TCO inhibits the proliferation of lung cancer cells both in vitro and in vivo. Our results demonstrated that TCO induces apoptosis in lung cancer cells. Moreover, we found that TCO suppresses EMT program and inhibits cell migration in vitro. Mechanistically, TCO decreases the expression of trophoblast cell surface antigen 2 (Trop2), resulting in inhibition of the PI3K/Akt pathway and EMT program. Overexpression of Trop2 rescues TCO-induced inhibition of cell proliferation and EMT. Our findings demonstrate that TCO markedly inhibits cell proliferation and EMT in lung cancer cells and provides guidance for its drug development.

NORAD regulates epithelial‑mesenchymal transition of non‑small cell lung cancer cells via miR‑422a.

The poor prognosis of non-small cell lung cancer (NSCLC) is related to epithelial-mesenchymal transition (EMT). Recent studies demonstrated that non-coding RNA activated by DNA damage (NORAD) displays a carcinogenic effect and targets microRNA (miR)-422a, which may be involved in tumor cell migration and invasion. The aim of the present study was to investigate the effect of NORAD on NSCLC cell EMT and the underlying mechanism. Reverse transcription-quantitative PCR and western blotting were performed to detect the expression levels of long non-coding RNAs, miRNAs and mRNAs. Cell viability, migration and invasion were detected by conducting Cell Counting Kit-8, wound healing and Transwell assays, respectively. The target of NORAD was predicted using starBase and further confirmed by conducting a dual-luciferase reporter assay. The results indicated that NORAD expression was significantly increased in lung cancer tissues and cells compared with adjacent healthy tissues and cells. Compared with the control groups, NORAD overexpression promoted SK-MES-1 cell viability, migration and invasion, whereas NORAD knockdown resulted in the opposite effects in A549 cells. Moreover, miR-422a, which was predicted to be a target of NORAD, displayed lower expression levels in lung cancer tissues compared with adjacent healthy tissues. In addition, miR-422a overexpression partially reversed NORAD overexpression-induced increases in SK-MES-1 cell viability, migration, invasion and EMT. In addition, miR-422a knockdown partially reversed the effects of NORAD knockdown. The present study suggested that NORAD regulated lung cancer cell EMT by regulating the expression of miR-422a, providing a potential therapeutic target for the intervention of the development of NSCLC.

Microenvironmental Th9 and Th17 lymphocytes induce metastatic spreading in lung cancer.

Immune microenvironment plays a critical role in lung cancer control versus progression and metastasis. In this investigation, we explored the effect of tumor-infiltrating lymphocyte subpopulations on lung cancer biology by studying in vitro cocultures, in vivo mouse models, and human lung cancer tissue. Lymphocyte conditioned media (CM) induced epithelial-mesenchymal transition (EMT) and migration in both primary human lung cancer cells and cell lines. Correspondingly, major accumulation of Th9 and Th17 cells was detected in human lung cancer tissue and correlated with poor survival. Coculturing lung cancer cells with Th9/Th17 cells or exposing them to the respective CM induced EMT in cancer cells and modulated the expression profile of genes implicated in EMT and metastasis. These features were reproduced by the signatory cytokines IL-9 and IL-17, with gene regulatory profiles evoked by these cytokines partly overlapping and partly complementary. Coinjection of Th9/Th17 cells with tumor cells in WT, Rag1-/-, Il9r-/-, and Il17ra-/- mice altered tumor growth and metastasis. Accordingly, inhibition of IL-9 or IL-17 cytokines by neutralizing antibodies decreased EMT and slowed lung cancer progression and metastasis. In conclusion, Th9 and Th17 lymphocytes induce lung cancer cell EMT, thereby promoting migration and metastatic spreading and offering potentially novel therapeutic strategies.

Inhibition of MiR-10b Restrains the Migration and Epithelial-Mesenchymal Transition of Lung Cells by Targeting LATS2 via TAZ Pathway.

BackgroundMiR-10b can promote the growth of lung cancer cells. LATS2 is reported to regulate lung cancer cell proliferation. We aimed to study the relationship between miR-10b and LATS2 in lung cancer.Material/MethodsMiR-10b and LATS2 in lung cancer tissues and cells were measured via real-time polymerase chain reaction (RT-PCR) and western blotting. Luciferase reporter assay and mimic transfection were performed to study relation between miR-10b and LATS2. MiR-10b inhibitor was transfected to downregulate miR-10b expression and LATS2 was further downregulated. Then, the proliferation, apoptosis, migration, and invasion capacity of lung cancer cells were measured, respectively. Lung cancer cells stably transfected with LATS2 and TAZ plasmids were constructed as usual, and the effect of LATS2 overexpression on epithelial-mesenchymal transition (EMT) was determined.ResultsMiR-10b was upregulated and LATS2 was significantly downregulated in lung cancer. Inhibition of miR-10b restrained the growth of lung cancer cells and accelerated the apoptosis of lung cancer cells. LATS2 is directly bound by miR-10b and silence of LATS2 reversed its inhibitory and promotive effects. Overexpression of LATS2 inhibited the EMT of lung cancer cells by inhibiting the TAZ pathway.ConclusionsMiR-10b was upregulated in lung cancer. Inhibition of miR-10b could restrain the development of lung cancer by increasing LATS2 expression via TAZ.

The anti-tumor effect of taxifolin on lung cancer via suppressing stemness and epithelial-mesenchymal transition in vitro and oncogenesis in nude mice.

BackgroundTaxifolin is a natural flavonoid with anti-oxidant and anti-proliferative properties. In this study, we investigated the stemness-related inhibitory effects of taxifolin in two lung cancer cell lines, A549 and H1975, as well as in A549 xenografts.MethodsA549 and H1975 cells, as well as A549 xenograft BALB/c mice were treated with taxifolin. Cell viability, stemness, mobility and protein expression were tested with Cell counting kit-8 (CCK-8), Colony formation assay, Flow cytometry, Transwell, Western blot and Immunohistochemistry, respectively.ResultsCCK-8 exhibited an obvious toxicity of taxifolin to both cell lines at higher dose. Then taxifolin of 0, 25, 50, and 100 µM/L were subsequently used. Taxifolin exhibited inhibitory effects on stemness and sphere formation, reduced protein expression of SOX2 and OCT4, and reduced CD133-positive cells. Furthermore, taxifolin decreased invasive cells, reduced N-cadherin and vimentin while increased E-cadherin expression, indicating that epithelial-mesenchymal transition (EMT) was inhibited. All of the effects observed were exhibited in a dose-dependent manner, and A549 cells proved to be more sensitive to taxifolin than H1975 cells. Taxifolin inactivated PI3K and TCF4 protein phosphorylation; however, taxifolin was not observed to have an effect on NF-κB P65 or STAT3. Taxifolin also suppressed tumor growth in A549 xenograft BALB/c mice, with decreased SOX2 and OCT4 expression and inhibited PI3K and TCF4.ConclusionsIn summary, taxifolin inhibited stemness and EMT in lung cancer cells possibly via the inactivation of PI3K and OCT4. Taxifolin could be a potential prodrug or serve as an adjuvant in lung cancer treatment.