Clinical Non-small Cell Lung Cancer Tissues Research Articles

Lnc AC016727.1/BACH1/HIF-1 α signal loop promotes the progression of non-small cell lung cancer

BackgroundLong noncoding RNAs (lncRNAs) have been reported to play vital roles in the development and progression of cancer. However, their biological significance and functional mechanisms in non-small cell lung cancer (NSCLC) are mostly unclear.MethodsWe performed RNA-sequencing to predict the differential expression of lncRNAs in clinical NSCLC and paired paracancerous lung tissues. To identify lncRNA expression, quantitative polymerase chain reaction (qPCR) was used. Using both cell and mouse models, We studied lncRNA AC016727.1’s function in NSCLC growth and metastasis. Western blot assays, dual luciferase reporter assays, and chromatin immunoprecipitation were used to analyze the functional mechanism of lncRNA AC016727.1.ResultsOur larger NSCLC cohorts validated that the lncRNA AC016727.1 was upregulated in 94 paired NSCLC tissues and correlated with poor survival. Functionally, lncRNA AC016727.1 downregulation inhibited NSCLC cell proliferation, aerobic glycolysis, EMT, and migration, inducing apoptosis. Conversely, upregulated lncRNA AC016727.1 expression exhibited the opposite effect, promoting NSCLC cell survival. Importantly, lncRNA AC016727.1 knockdown inhibited lung cancer growth and slowed the progression of lung metastasis in nude mouse models. Mechanistically, lncRNA AC016727.1 upregulated BACH1 target gene expression by acting as a sponge for miR-98-5p, thereby functioning as a competing endogenous RNA. The function of lncRNA AC016727.1 is mediated by the miR-98-5p/BACH1 axis in NSCLC cells. Meanwhile, the transcription factor HIF-1α can bind to the promoter and activate lncRNA AC016727.1 transcription. lncRNA AC016727.1 regulates HIF-1α expression via BACH1 in NSCLC and forms the lncRNA AC016727.1/BACH1/HIF-1α signaling loop under hypoxic conditions.ConclusionOur study reveals a novel lncRNA AC016727.1/BACH1/HIF-1α signaling loop in the progression of NSCLC under hypoxic conditions, suggesting that lncRNA AC016727.1 could act as a useful biomarker for NSCLC and a new therapeutic target.

Methylation of KRAS by SETD7 promotes KRAS degradation in non-small cell lung cancer

Oncogenic KRAS mutations are a key driver for initiation and progression in non-small cell lung cancer (NSCLC). However, how post-translational modifications (PTMs) of KRAS, especially methylation, modify KRAS activity remain largely unclear. Here, we show that SET domain containing histone lysine methyltransferase 7 (SETD7) interacts with KRAS and methylates KRAS at lysines 182 and 184. SETD7-mediated methylation of KRAS leads to degradation of KRAS and attenuation of the RAS/MEK/ERK signaling cascade, endowing SETD7 with a potent tumor-suppressive role in NSCLC, both invitro and invivo. Mechanistically, RABGEF1, a ubiquitin E3 ligase of KRAS, is recruited and promotes KRAS degradation in a K182/K184 methylation-dependent manner. Notably, SETD7 is inversely correlated with KRAS at the protein level in clinical NSCLC tissues. Low SETD7 or RABGEF1 expression is associated with poor prognosis in lung adenocarcinoma patients. Altogether, our results define a tumor-suppressive function of SETD7 that operates via modulating KRAS methylation and degradation.

Selenium-binding protein 1 inhibits malignant progression and induces apoptosis via distinct mechanisms in non-small cell lung cancer.

Selenium is an essential trace element in the human body. In epidemiological and clinical studies, Se supplementation significantly reduced the incidence of lung cancer in individuals with low baseline Se levels. The significant action of selenium is based on the selenium-containing protein as a mediator. Of note, the previous studies reported that the expression of selenium-binding protein 1 (SELENBP1) was obviously decreased in many human cancer tissues including non-small cell lung cancer (NSCLC). However, its roles in the origin and development of NSCLC are still unclear. The expression of SELENBP1 was measured by qRT-PCR, Western blotting and IHC in our collected clinical NSCLC tissues and cell lines. Next, the CCK-8, colony formation, wound-haeling, Millicell, Transwell, FCM assay, and in vivo xenograft model were performed to explore the function of SELENBP1 in NSCLC. The molecular mechanisms of SELENBP1 were investigated by Western blotting or IF assay. We further identified that the expression of SELENBP1 was significantly decreased in NSCLC tissues in TCGA database and 45 out of 59 collected clinical NSCLC tissues compared with adjacent nontumor tissues, as well as in four NSCLC cell lines compared with normal lung cells. Particularly, we unexpectedly discovered that SELENBP1 was obviously expressed in alveolar type 2 (AT-II) cells for the first time. Then, a series of in vitro experiments uncovered that overexpression of SELENBP1 inhibited the proliferation, migration, and invasion of NSCLC cells, and induced cell apoptosis. Moreover, overexpression of SELENBP1 also inhibited growth and induced apoptosis of NSCLC cells in vivo. Mechanistically, we demonstrated that overexpression of SELENBP1 inhibited the malignant characteristics of NSCLC cells in part via inactivating the PI3K/AKT/mTOR signal pathway. Meanwhile, we found that overexpression of SELENBP1 inducing the apoptosis of NSCLC cells was associated with the activation of caspase-3 signaling pathway under nonhigh level of oxidative stress, but overexpression of SELENBP1 facilitating the cell apoptosis might be related to its combining with GPX1 and colocalizing in the nucleus under high level of oxidative stress. Our findings highlighted that SELENBP1 was an important tumor suppressor during the origin and development of NSCLC. It may help to discover novel biomarkers or drug therapy targets for NSCLC.

LncRNA SH3BP5-AS1 Regulates the Proliferation and Cell Cycle of Non-Small Cell Lung Cancer Cells

Background: Non-small cell lung cancer (NSCLC) consists of a class of heterogeneous diseases. Objective: LncRNAs are exceedingly implicated in the pathogenesis of NSCLC. Herein, the current study set out to illustrate the molecular mechanism of SH3BP5-AS1 in NSCLC cells. Methods: SH3BP5-AS1 expression in clinical NSCLC tissues and its impact on prognosis were analyzed by bioinformatics database. SH3BP5-AS1 expression patterns in NSCLC cell lines (A549/H1299/H1975/H460) and human normal lung epithelial cell lines (BEAS-2B) were examined by RT-qPCR. SH3BP5-AS1 was overexpressed in A549 or silenced in H1975 cells through transfection to assess its effect on proliferation, cell cycle distribution, and apoptosis, apoptosisrelated protein (Cleaved Caspase-3, Bax, Bcl-2) levels, invasive, migratory, and healing capacity through CCK-8, colony formation assay, flow cytometry, Western blot, Transwell, and cell scratch test. Results: SH3BP5-AS1 was under-expressed in NSCLC clinical tissues, and NSCLC patients with low SH3BP5-AS1 expression showed poor prognosis. A549/H1299/H1975/H460 cells had reduced levels of SH3BP5-AS1, with the relative level lowest/highest expression in A549/H1975 cells, respectively. SH3BP5-AS1 overexpression repressed A549 cell proliferation, slowed down cell cycle progression, enhanced apoptosis, elevated Cleared Caspase-3, Bax, suppressed Bcl-2 protein levels, and inhibited migratory, invasive, and scratch healing capacities, while SH3BP5-AS1 silencing brought about the opposite results in H1975 cells. Conclusion: SH3BP5-AS1 could suppress NSCLC cell proliferation, slow down cell cycle progression, stimulate apoptosis, and limit invasion and migration.

Butein suppresses PD-L1 expression via downregulating STAT1 in non-small cell lung cancer

PD-L1 (programmed cell death ligand 1) is frequently up-regulated in tumors and is critical in tumor immune escape. In addition to antibodies that block the interaction between PD-L1 and PD-1 (programmed cell death protein 1), small-molecule compounds that suppress PD-L1 expression also exhibit significant anti-tumor effects, emerging as a new strategy targeting PD-L1. By using a cell-based screening model, we found that butein, a natural chalcone compound, significantly reduced the cytoplasm and cell surface expression of PD-L1. This effect was further validated in various non-small cell lung cancer (NSCLC) cell lines and primary cells derived from clinical NSCLC tissues. Butein inhibited PD-L1 transcription, but not the half-life of PD-L1 protein. Butein reduced STAT1 level and butein-induced PD-L1 suppression was eliminated by the absence of STAT1. By co-culture system, butein improved tumor elimination by increasing the killing ability of CD8+ T cells. By in vivo study, we further confirmed that butein downregulated PD-L1 expression and improved infiltration of CD8+ T cells in tumor tissues. Taken together, our study suggested that butein could suppress the transcription of PD-L1 via downregulating STAT1, providing a theoretical basis for the application of butein in anti-tumor therapy.

The Potential Mechanism of HDAC1-Catalyzed Histone Crotonylation of Caspase-1 in Nonsmall Cell Lung Cancer.

Nonsmall cell lung cancer (NSCLC) is a predominant subtype of lung cancer and accounts for over 80% of all lung cancer cases. The resistance to pemetrexed (PEM) is frequently occurred and severely affects the NSCLC therapy. Proteomic analysis of histones indicated that the histone deacetylase 1 (HDAC1) complex could hydrolyze lysine crotonylation on histone3 (H3K18cr), affecting epigenetic regulation in cancers. However, the effect of HDAC1-mediated H3K18cr on the PEM resistance of NSCLC is still unclear. Here, we aimed to explore the function of HDAC1-mediated H3K18cr in NSCLC PEM resistance. The expression of HDAC1 was upregulated in clinical NSCLC tissues and cell lines and correlated with the poor prognosis of NSCLC samples. We constructed the PEM-resistant NSCLC cell lines, and the depletion of HDAC1 remarkably reduced the viability of the cells. The proliferation of PEM-resistant NSCLC cells was decreased by HDAC1 knockdown, and the IC50 of PEM was repressed by the silencing of HDAC1 in the cells. Mechanically, we identified the enrichment of HDAC1 on the promoter of caspase-1 in PEM-resistant NSCLC cells. The depletion of HDAC1 inhibited the enrichment of histone H3K18cr and RNA polymerase II (RNA pol II) on the caspase-1 promoter in the cells. The expression of caspase-1 was suppressed by HDAC1 knockdown. The knockdown of HDAC1 reduced proliferation of PEM-resistant NSCLC cells, in which caspase-1 or GSDMD depletion reversed the effect. Clinically, the HDAC1 expression was negatively associated with caspase-1 and GSDMD in clinical NSCLC tissues, while caspase-1 and GSDMD expression was positively correlated in the samples. Therefore, we concluded that HDAC1-catalyzed histone crotonylation of caspase-1 modulates PEM sensitivity of NSCLC by targeting GSDMD.

Silencing of A-kinase anchor protein 4 inhibits the metastasis and growth of non-small cell lung cancer

ABSTRACT Non-small cell lung cancer (NSCLC) is one of the most malignant tumors. The treatment of advanced NSCLC can be challenging due to drug resistance. The discovery of novel cancer-testis antigens to develop new strategies for advanced metastatic NSCLC is required. AKAP4 is an oncogene discovered in some malignant tumors, and its molecular function of AKAP4 in NSCLC is unknown. This study aimed to explore the potential function of AKAP4 in the development and progression of NSCLC. AKAP-4 was found to be significantly upregulated in both clinical NSCLC tissues and NSCLC cell lines. Cell viability and migration were suppressed, apoptosis was induced, and tube formation was inhibited by the knockdown of AKAP-4, accompanied by the downregulation of VEGF, N-cadherin, EphA2, and MMP-2, and upregulation of c-AMP, PKA, and E-cadherin. In vivo xenograft experiments revealed that tumor growth was inhibited by the knockdown of AKAP4, accompanied by the activation of c-AMP/PKA signaling and inhibition of epithelial-mesenchymal transition progression. Our results show that AKAP4 might be an important target for treating NSCLC because of its function in promoting the migration and proliferation of NSCLC cells.

MiR-532-5p Inhibits Non-Small Cell Lung Cancer Progression In Vivo and In Vitro by Targeting Yin Yang 1.

Lung cancer is a common cancer that is familiar to people and has the highest global incidence; among all lung cancer patients, 85% are non-small cell lung cancer (NSCLC). A number of microRNAs (miRNAs), including miR-532-5p, are implicated in the pathophysiological processes of tumorigenesis. However, the mechanism of miR-532-5p in NSCLC remains unclear. In the current study, the expression of miR-532-5p was found to be markedly downregulated in clinical NSCLC tissues and cell lines. Further study indicated that ectopic expression of miR-532-5p inhibited NSCLC cell proliferation and invasion while accelerating in vitro, but silencing miR-532-5p had an opposite result. Furthermore, functional experiments revealed that miR-532-5p effectively blocked tumor growth in a xenograft tumor mouse model. Bioinformatics and luciferase reporter analysis verified that Yin Yang 1 (YY1) transcripts are targets of miR-532-5p. Moreover, the expression of YY1 was negatively regulated by miR-532-5p in NSCLC cells. In vivo assays indicated that downregulation of YY1 inhibited tumor growth. Notably, overexpression of YY1 effectively counteracted the tumor-suppressing effects of miR-532-5p in vitro and in vivo. In summary, this study demonstrated the tumor-suppressive role of miR-532-5p in NSCLC by regulating YY1 in vitro and in vivo.

MicroRNA-32-5p inhibits epithelial-mesenchymal transition and metastasis in lung adenocarcinoma by targeting SMAD family 3.

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-associated death worldwide. MicroRNA (miRNA)-32-5p is as an important cancer-associated miRNA in different types cancer. To date, the role of miR-32-5p in the migration and invasion of NSCLC remains unknown. In the present study, a Transwell assay was performed to investigate the role of miR-32-5p in lung adenocarcinoma. miR-32-5p expression level was determined via reverse transcription-quantitative PCR in 24 pairs of NSCLC and adjacent normal tissues. SMAD family member 3 (SMAD3) was considered as a novel target gene by luciferase reporter assay and western blot in NSCLC. The present study demonstrated that miR-32-5p is frequently downregulated in NSCLC tissues. The overexpression of miR-32-5p resulted in the inhibition of migratory and invasive abilities in NSCLC cells. Thus, SMAD3 was identified as a target of miR-32-5p, and its expression was negatively correlated with miR-32-5p expression in clinical NSCLC tissues. Overall, these findings indicate that miR-32-5p serves as a tumor suppressor by targeting SMAD3. Thus, miR-32-5p may be a potential therapeutic target for the treatment of lung adenocarcinoma.

NT5DC2 suppression restrains progression towards metastasis of non-small-cell lung cancer through regulation p53 signaling

Non-small cell lung cancer (NSCLC) is a leading cause of tumor mortality worldwide. Nevertheless, the molecular mechanisms revealing NSCLC progression are still unclear. 5′-Nucleotidase domain containing 2 (NT5DC2), as a member of the NT5DC family, contains a haloacid dehalogenase motif localized in the N-terminus of these proteins. NT5DC2 plays an essential role in cancer development. The purpose of the study was to explore NT5DC2’s role in tumorigenesis and its potential mechanisms in NSCLC. Our findings showed that NT5DC2 expression was significantly up-regulated in clinical NSCLC tissues compared to the paired non-tumor tissues. Functionally, NT5DC2 knockdown in A549 and H1299 cells markedly reduced cell proliferation, migration and invasion. On the contrary, NT5DC2 over-expression promoted NSCLC cell proliferative, migrative and invasive capacities. Additionally, NT5DC2 down-regulation significantly induced the G2 cell cycle arrest and apoptosis in NSCLC cells. Mechanistically, p53 might be a target of NT5DC2. The expression of p53 was highly induced in NSCLC cells with NT5DC2 knockdown, and opposite result was detected when NT5DC2 was over-expressed. Importantly, we found that NT5DC2 knockdown-restrained cell proliferation and -induced apoptosis was almost abrogated by p53 down-regulation in NSCLC cells, demonstrating that NT5DC2-regulated cell proliferation and apoptotic cell death in NSCLC was p53-dependent. Finally, we confirmed that reducing NT5DC2 could inhibit NSCLC tumorigenesis and hepatic metastasis in vivo. Collectively, these results suggested that NT5DC2 may be a potential driver of NSCLC, providing a new therapeutic target for the clinical treatment of NSCLC.

Fluorescence imaging of biochemical relationship between ubiquitinated histone 2A and Polycomb complex protein BMI1

Several in vitro experiments have highlighted that the Polycomb group protein BMI1 plays a pivotal role in determining the biological functions of the Polycomb Repressor Complex 1 (PRC1), including its E3-ligase activity towards the Lys119 of histone H2A to yield ubiquitinated uH2A. The role of BMI1 in the epigenetic activity of PRC1 is particularly relevant in several cancers, particularly Non-Small Cell Lung Cancer (NSCLC). In this study, using indirect immunofluorescence protocols implemented on a confocal microscopy apparatus, we investigated the relationship between BMI1 and uH2A at different resolutions, in cultured (A549) and clinical NSCLC tissues, at the single cell level. In both cases, we observed a linear dependence of uH2A concentration upon BMI1 expression at the single nucleus level, indicating that the association of BMI1 to PRC1, which is needed for E3-ligase activity, occurs linearly in the physiological BMI1 concentration range. Additionally, in the NSCLC cell line model, a minor pool of uH2A may exist in absence of concurrent BMI1 expression, indicating non-exclusive, although predominant, role of BMI1 in the amplification of the E3-ligase activity of PRC1. A pharmacological downregulator of BMI1, PTC-209, was also tested in this context. Finally, the absence of significant colocalization (as measured by the Pearson's coefficient) between BMI1 and uH2A submicron clusters hints to a dynamic model where PRC1 resides transiently at ubiquitination sites. Beside unveiling subtle functional relationships between BMI1 and uH2A, these results also validate the use of uH2A as downstream “reporter” for BMI1 activity at the nuclear level in NSCLC contexts.

MiR-194 suppresses high glucose-induced non-small cell lung cancer cell progression by targeting NFAT5.

BackgroundDiabetes mellitus (DM) is linked to an increased risk of lung cancer; however, the exact molecular basis is unclear.MethodsWe used a microarray method and found a group of microRNAs differently expressed in lung cancer cells at high or low glucose treatment.ResultsAmong these, miR‐194 changed significantly, which indicated further analysis. miR‐194 was significantly downregulated in non‐small cell lung cancer (NSCLC) cells cultured in high glucose (HG) medium and clinical NSCLC tissues with DM. The introduction of miR‐194 significantly suppressed the proliferation, migration, and invasion of lung cancer cells induced by HG, suggesting that miR‐194 may be a suppressor during HG‐induced NSCLC progression. Further analysis indicated that NFAT5 was a direct target gene of miR‐194, evidenced by the direct binding of miR‐194 with the 3’untranslated region of NFAT5. MiR‐194 could decrease the expression of NFAT5 at both messenger RNA and protein levels, while overexpression of NFAT5 reversed the decreased proliferation, migration, and invasion ability mediated by miR‐194 in lung cancer cells.ConclusionOur findings provide new insight into the mechanism of NSCLC progression. Therapeutically, miR‐194 may serve as a potential target for the treatment of lung cancer patients with DM.

Circular RNA PVT1 acts as a competing endogenous RNA for miR-497 in promoting non-small cell lung cancer progression

Circular RNAs (circRNAs) are a class of covalently closed non-coding RNAs and play crucial regulatory roles in human cancer biology. The purpose of the present study was to explore the expression pattern and biological role of circular RNA PVT1 (circPVT1) in non-small cell lung cancer (NSCLC). We firstly found that circPVT1 was overexpressed in clinical NSCLC tissues and cell lines. NSCLC patients with high expression of circPVT1 exhibited aggressive clinicopathological characteristics and poor prognosis. In vitro assays of the NSCLC cell lines (H1299 and A549 cells) demonstrated that knockdown of circPVT1 inhibited NSCLC cell proliferation and induced NSCLC cell apoptosis. We further found that circPVT1 served as a competing endogenous RNA of miR-497 and indirectly regulated Bcl-2 expression in NSCLC cells. Finally, inhibition of miR-497 abrogated the effects of circPVT1 knockdown in NSCLC cells. Taken together, the results from our study indicated circPVT1 acts as an oncogene in NSCLC, and may serve as a promising therapeutic target for NSCLC patients.

Estrogen-related receptor alpha triggers the proliferation and migration of human non-small cell lung cancer via interleukin-6.

Human non-small cell lung cancer (NSCLC) is one of the leading causes of cancer deaths worldwide. Estrogenic signals have been suggested to be important for the growth and metastasis of NSCLC cells. Our present data showed that estrogen-related receptor alpha (ERRα), while not ERRβ or ERRγ, was significantly elevated in NSCLC cell lines as compared with that in normal bronchial epithelial cell line BEAS-2B. The expression of ERRα in clinical NSCLC tissues was significantly greater than that in their matched normal adjacent tissues. Over expression of ERRα can trigger the proliferation, migration, and invasion of NSCLC cells, while si-ERRα or ERRα inhibitor showed opposite effects. ERRα can increase the mRNA and protein expression of IL-6, while not IL-8, IL-10, IL-22, VEGF, TGF-β, or TNF-α, in NSCLC cells. Silence of IL-6 attenuated ERRα induced proliferation and cell invasion. Furthermore, our data revealed the inhibition of NF-κB, while not ERK1/2 or PI3K/Akt, abolished ERRα induced production of IL-6. This might be due to that overexpression of ERRα can increase the expression and nuclear translocation of p65 in NSCLC cells. Collectively, our data showed that activation of NF-κB/IL-6 is involved in ERRα induced migration and invasion of NSCLC cells. It suggested that ERRα might be a potential target for NSCLC treatment.

MicroRNA-29c inhibits proliferation and promotes apoptosis in non-small cell lung cancer cells by targeting VEGFA.

Non-small cell lung cancer (NSCLC) is a primary sub-type of lung cancer with a high incidence rate and poor prognosis. The primary therapeutic treatment for NSCLC is chemotherapy, which is considered to be ineffective and excessively toxic. Novel therapeutic methods, particularly molecular targeted therapy, have attracted considerable attention. MicroRNAs (miRs) are reported to be potential biomarkers and targeted agents with roles in various types of tumors. Herein, the present study presented the observation of aberrant low expression of miR‑29c and associated overexpression of vascular endothelial growth factorA (VEGFA) in NSCLC tumor tissues. The effects of miR‑29c upon NSCLC tumor progression, including cell proliferation and cellular apoptosis, were investigated. The possible regulatory mechanism of action of miR‑29c on its direct target VEGFA and the phosphatidylinositol 3‑kinase (PI3K)/RAC‑α serine/threonine‑protein kinase (Akt) signaling pathway was examined using multiple methods, including reverse transcription-quantitative polymerase chain reaction analysis, dual luciferase assay and western blot analysis. The results demonstrated that miR‑29c expression was downregulated in NSCLC tumor tissues compared with normal tissues. A marked negative correlation in the expression of miR‑29c and VEGFA was observed in clinical NSCLC tissues and cultured NSCLC cells. Overexpression of miR‑29c may inhibit cell proliferation and accelerate the cellular apoptosis rate of NSCLC tumor cells. Furthermore, the overexpression of miR‑29c was demonstrated to be able to downregulate the expression levels of VEGFA and PI3K/Akt signaling pathway‑associated proteins. The results of the present study suggested that miR‑29c might regulate NSCLC tumor progression by targeting VEGFA.

MiR-138 suppresses the proliferation, metastasis and autophagy of non-small cell lung cancer by targeting Sirt1.

The present study determined the role and mechanism of miR-138 in non-small cell lung cancer (NSCLC). In total, 45 freshly resected clinical NSCLC tissues were collected. The expression of miR-138 in tissues and cell lines were determined by real-time quantitative PCR. miR-138 mimics were transfected into A549 and Calu-3 cells in vitro, and then the effects of miR-138 on lung cancer cell proliferation, cell cycle, invasion and metastasis were investigated by CCK-8 assay, Transwell and flow cytometry, respectively. The protein expression of the potential target gene Sirt1 in lung cancer cells were determined by western blot analysis. Dual-Luciferase reporter assay was performed to further confirm whether Sirt1 was the target gene of miR-138. The expression of miR-138 was significantly lower in lung cancer tissues and was negatively correlated to the differentiation degree and lymph node metastasis of lung cancer. In vitro experiment results showed that miR-138 inhibited lung cancer cell proliferation, invasion and migration. It was verified that miR-138 could downregulate Sirt1 protein expression, inhibit epithelial-mesenchymal transition (EMT), decrease the activity of AMPK signaling pathway and elevate mTOR phosphorylation level. Dual-Luciferase reporter assay demonstrated that miR-138 could directly regulate Sirt1. Downregulation of Sirt1 alone can also cause the same molecular and biological function changes. Western blot analysis and confocal microscopy results indicated that overexpression of miR-138 or interference of Sirt1 expression could inhibit lung cancer cell autophagy activity possibly through AMPK-mTOR signaling pathway. miR-138 plays a tumor suppressor function in lung cancer. It may inhibit the proliferation, invasion and migration of lung cancer through downregulation of Sirt1 expression and activation of cell autophagy. The downregulation of miR-138 is closely related to the development of lung cancer.

Amino acid transporter SLC38A3 promotes metastasis of non-small cell lung cancer cells by activating PDK1

BackgroundTumor metastasis is a finely-tuned pathological process coupled to metabolic reprogramming that includes both glutamine and glucose. The solute carrier SLC38A3, a member of amino acid/polyamine/organocation (APC) superfamily, is an l-glutamine transporter. It is not clear whether SLC38A3 involves the metastasis of NSCLC (non small cell lung cancer). MethodsThe scratch test and transwell assay were used to determine the ability of NSCLC to migrate. Cellular amino acids content was determined by mass spectrometry. The cellular response to glutamine/histidine deficiency was evaluated in A549 cells. The expression of SLC38A3 was assayed in clinical NSCLC and paratumor tissues by histoimmunochemistry staining. A nude mouse model of NSCLC metastasis was developed by tail vein injection of tumor cells. ResultsSLC38A3 was upregulated in metastatic NSCLC cells and its expression was correlated with prognosis of NSCLC patients. SLC38A3 overexpression promoted epithelial – mesenchymal transition (EMT) and migration of HCC827 and A549 human lung adenocarcinoma cells, and accelerated tumor metastasis in mice. We found that SLC38A3 decreased the cellular concentrations of glutamine and histidine, and the deficiency of glutamine or histidine activated PDK1/AKT signaling that in turn, triggered NSCLC metastasis. ConclusionsSLC38A3 activated PDK1/AKT signaling and promoted metastasis of NSCLC through regulating glutamine and histidine transport, suggesting SLC38A3 as a potential therapeutic target for treatment of NSCLC.

Contribution of upregulated dipeptidyl peptidase 9 (DPP9) in promoting tumoregenicity, metastasis and the prediction of poor prognosis in non-small cell lung cancer (NSCLC).

Dipeptidyl peptidase 9 (DPP9) is encoded by DPP9, which belongs to the DPP4 gene family. Proteins encoded by these genes have unique peptidase and extra‐enzymatic functions that have been linked to various diseases including cancers. Here, we describe the expression pattern and biological function of DPP9 in non‐small‐cell lung cancer (NSCLC). The repression of DPP9 expression by small interfering RNA inhibited cell proliferation, migration, and invasion. Moreover, we explored the role of DPP9 in regulating epithelial‐mesenchymal transition (EMT). The epithelial markers E‐cadherin and MUC1 were significantly increased, while mesenchymal markers vimentin and S100A4 were markedly decreased in DPP9 knockdown cells. The downregulation of DPP9 in the NSCLC cells induced the expression of apoptosis‐associated proteins both in vitro and in vivo. We investigated the protein expression levels of DPP9 by tissue microarray immunohistochemical assay (TMA‐IHC) (n = 217). Further we found mRNA expression levels of DPP9 in 30 pairs of clinical NSCLC tissues were significantly lower than in the adjacent non‐cancerous tissues. Survival analysis showed that the overexpression of DPP9 was a significant independent factor for poor 5‐year overall survival in patients with NSCLC (p = 0.003). Taken together, DPP9 expression correlates with poor overall survival in NSCLC.

MicroRNA-383 is a tumor suppressor and potential prognostic biomarker in human non-small cell lung caner.

The purpose of this study is to examine the expression and clinical significance microRNA-383 (miR-383) in non-small cell lung cancer (NSCLC) both in vitro and in vivo. Tumorous miR-383 expressions were compared between NSCLC cell lines and normal lung cells. MiR-383 was upregulated in A549 and H596 cells to evaluate its tumor suppressive effect on NSCLC proliferation, invasion and migration in vitro. MiR-383 expression was also compared between 139-paired clinical NSCLC tissues and their adjacent non-carcinoma lung tissues, as well as between early-stage NSCLC tissues and advanced-stage NSCLC tissues. Correlation between tumorous miR-383 expression and NSCLC patients' clinicopathological features and overall survival (OS) were also statistically analyzed. MiR-383 was significantly downregulated in NSCLC cell lines. MiR-383 overexpression reduced proliferation, invasion and migration of A549 and H596 cells. In clinical samples, miR-383 was also found to be markedly downregulated in NSCLC carcinomas than in non-carcinoma lung tissues, and in advanced-stage carcinomas than in early-stage carcinomas. It was also found low tumorous miR-383 expression was significantly associated with NSCLC patients' poor prognosis, including advanced TNM stages, positive lymph node metastasis, and shorter OS. Endogenous miR-383 is a functional tumor suppressor in NSCLC. It may also serve as an independent prognostic factor for patients with NSCLC.

Down-regulation of miR-452 is associated with poor prognosis in the non-small-cell lung cancer.

Non-small cell lung cancer (NSCLC) remains the most life-threatening cancer in the world. The aim of the current study was to investigate the value of miR-452 for the prognosis of patients with NSCLC. Real-time quantitative PCR (qRT-PCR) was used to test the expression level of miR-452 in 161 paired clinical NSCLC tissues and their adjacent tissues. Survival curves were made and the log rank test was used to analyze the survival difference between both groups with higher and lower expression level of miR-452. Univariate and multivariate Cox regression analyses were finally used to determine the independent factors for overall survival (OS) and disease-free survival (DFS) times. The miR-452 expressions in tumor samples (n=161) were comparably lower than those in the adjacent tissues. miR-452 expression levels were significantly associated with tumor differentiation grade, tumor size and lymph nodes metastasis. Furthermore, Kaplan-Meier survival curves showed that patients with higher expression of miR-452 was confirmed to have more favorable OS (P=0.004) and DFS (P=0.026). Multivariate survival analysis verified that miR-452 expression level, as well as lymph nodes metastasis, was an independent predictor of both OS and DFS for NSCLC patients. Our study demonstrated that miR-452 functioned as a novel diagnostic biomarker and a promising prognostic predictor for NSCLC patients.