Distinct N7-methylguanosine profiles of circular RNAs in drug-resistant acute myeloid leukemia.

Post-transcriptional methylation modifications, such as the N7-methylguanosine (m7G) modification, are increasingly acknowledged for their role in the development and resistance to chemotherapy in acute myeloid leukemia (AML). This study employed MeRIP-seq technology to investigate the m7G sites within circular RNAs (circRNAs) derived from human AML cells and drug-resistant AML cells, in order to identify these sites more comprehensively. In addition, a detailed analysis of the relationship between m7G and drug-resistant AML was conducted. The bioinformatics analysis was utilized to predict the functions of specific methylated transcripts. The findings revealed a significant difference in m7G level between AML cells and drug-resistant AML cells, suggesting a potentially critical role of m7G in circRNAs in drug-resistant AML development. The methylation of M7G could affect the circRNA-miRNA-mRNA co-expression during the development of AML resistance, which could further influence the regulation of resistance-associated target genes in AML. Furthermore, gene ontology analysis indicated that the distinct distribution pattern of circRNAs with m7G methylation in drug-resistant AML cells was correlated with metabolism-related pathways. These results suggested a potential association between drug-resistant AML and m7G methylation of circRNAs. Moreover, the results revealed a novel role of m7G RNA methylation in circRNAs in the progression of AML chemoresistance.

UHMK1 promotes lung adenocarcinoma oncogenesis by regulating the PI3K/AKT/mTOR signaling pathway.

BACKGROUND: Effective targeted therapy for lung adenocarcinoma (LUAD), the number one cancer killer worldwide, continues to be a difficult problem because of the limitation of number of applicable patients and acquired resistance. Identifying more promising drug targets for LUAD treatment holds immense clinical significance. Recent studies have revealed that the U2 auxiliary factor (U2AF) homology motif kinase 1 (UHMK1) is a robust pro-oncogenic factor in many cancers. However, its biological functions and the underlying molecular mechanisms in LUAD have not been investigated. METHODS: The UHMK1 expression in LUAD cells and tissues was evaluated by bioinformatics analysis, immunohistochemistry (IHC), western blotting (WB), and real time quantitative polymerase chain reaction (RT-qPCR) assays. A series of gain- and loss-of-function experiments for UHMK1 were carried out to investigate its biological functions in LUAD in vitro and in vivo. The mechanisms underlying UHMK1's effects in LUAD were analyzed by transcriptome sequencing and WB assays. RESULTS: UHMK1 expression was aberrantly elevated in LUAD tumors and cell lines and positively correlated with tumor size and unfavorable patient prognosis. Functionally, UHMK1 displayed robust pro-oncogenic capacity in LUAD and mechanistically exerted its biological effects via the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway. CONCLUSION: UHMK1 is a potent oncogene in LUAD. Targeting UHMK1 may significantly improve the effect of LUAD treatment via inhibiting multiple biological ways of LUAD progression.

Metabolic profiling reveals metabolic features of consolidation therapy in pediatric acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) and its treatment continue to pose substantial risks. To understand ALL more deeply, the metabolome in fasting plasma of 27 ALL patients before and after high-dose methotrexate therapies (consolidation therapy) including methotrexate and 6-mercaptopurine (6-MP) was investigated. Plasma metabolites were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS). Orthogonal projections to latent structures discriminant analysis and significance analysis of microarrays were used to evaluate the metabolic changes. Pathway enrichment and co-expression network analyses were performed to identify clusters of molecules, and 2826 metabolites were identified. Among them, 38 metabolites were identified by univariate analysis, and 7 metabolites that were altered by conditioning therapy were identified by multivariate analysis. The Kyoto Encyclopedia of Genes and Genomes (KEGG) database was used for pathway enrichment analysis. Among the enriched KEGG pathways, the 3 significantly altered metabolic pathways were pyrimidine metabolism; phenylalanine, tyrosine, and tryptophan biosynthesis; and phenylalanine metabolism. In addition, L-phenylalanine was significantly correlated with blood urea nitrogen (BUN), and palmitoylcarnitine was correlated with aspartate aminotransferase (AST). In summary, consolidation therapy significantly affected pyrimidine- and phenylalanine-associated metabolic pathways in pediatric ALL patients. These findings may provide an insight into the role of metabolic profiling in consolidation treatment and as a potential for pediatric ALL patients.

V7 ENB-guided thoracoscopic sublobectomy for stage IA synchronous multiple primary lung cancer.

BACKGROUND: An increasing number of patients are being diagnosed with synchronous multiple primary lung cancer (SMPLC) with the popularization of lung cancer screening programs. However, a strategy for accurate location and suitable surgery therapy is still lacking. The present study aimed to explore the accuracy and feasibility of electromagnetic navigation bronchoscopy (ENB)-guided thoracoscopic sublobectomy for stage IA SMPLC. METHODS: Patients with SMPLC who underwent ENB-guided sublobectomy from January 2020 to June 2022 were enrolled in this study. The analysis of localization accuracy of ENB and surgical outcome was conducted. RESULTS: Overall, 138 patients with 353 malignant nodules were enrolled. The tumor size was 0.7 cm (range from 0.5 to 1.1 cm). ENB localization was performed on 162 nodules, and a customized scoring system was developed to evaluate localization accuracy. The success rate of localization was 98.3% (178/181). Notably, localization accuracy was positively correlated with bronchial signs (p < 0.01) and negatively correlated with the distance from the nodule to the pleura (p = 0.02). All nodules were completely resected. Operation time, drainage volume on the third postoperative day, and catheter time were significantly correlated with the resected lesion numbers (p = 0.009, p = 0.004, and p = 0.01, respectively). CONCLUSIONS: ENB-guided uniportal video-assisted thoracoscopic sublobectomy provides accurate preoperative localization and avoids unnecessary lung resection of patients with stage IA SMPLC. However, complete resection of multilocation nodules (more than four lesions) increases the risk of postoperative complications. A new combined treatment strategy for SMPLC should be explored.

Corrigendum: Negatively regulated by miR-29c-3p, MTFR1 promotes the progression and glycolysis in lung adenocarcinoma via the AMPK/mTOR signalling pathway.

[This corrects the article DOI: 10.3389/fcell.2021.771824.].

Negatively Regulated by miR-29c-3p, MTFR1 Promotes the Progression and Glycolysis in Lung Adenocarcinoma via the AMPK/mTOR Signalling Pathway.

Background: Lung adenocarcinoma (LUAD) is the major form of lung cancer that presents a major peril to public health. Owing to the high rates of morbidity, mortality and chemoresistance, it is necessary to develop more effective therapeutic targets of LUAD. Mitochondrial fission regulator 1 (MTFR1) affects the occurrence and development of some diseases by regulating mitochondrial dynamics and is dysregulated in LUAD. However, the functions and molecular mechanisms of MTFR1 in LUAD have not been investigated. Methods: Immunohistochemical (IHC) analysis, real-time quantitative polymerase chain reaction (RT-qPCR), bioinformatic analysis and western blot (WB) were performed to assess the expression of MTFR1 at both protein and mRNA levels. The biological functions of MTFR1 in LUAD cells were assessed based on various in vivo and in vitro experiments. The dual-luciferase reporter assay and some rescue experiments were performed to evaluate the underlying mechanism of MTFR1 in LUAD. Results: MTFR1 was upregulated in LUAD cells and tissues and correlated with dismal clinicopathologic features and a worse prognosis of patients with LUAD. Functionally, MTFR1 overexpression stimulated the proliferation, invasion, migration and glycolytic capacity and impeded the apoptosis of LUAD cells; however, opposite results were obtained when MTFR1 expression was knocked down. MTFR1, which was directly targeted by miR-29c-3p, may exert its biological functions through the AMPK/mTOR signalling pathway. Conclusion: MTFR1 promotes the progression of LUAD. Therefore, targeting MTFR1 can offer an effective therapeutic strategy for LUAD treatment.

Circular RNA hsa-circ-000881 suppresses the progression of lung adenocarcinoma in vitro via a miR-665/PRICKLE2 axis.

BACKGROUND: Circular RNA (circRNA) has become a new focus in the field of tumor biology research in recent years. Many circRNAs have been showed to play an important role in the progression of lung adenocarcinoma (LUAD). In this work, we studied the oncological role of hsa-circ-000881 in LUAD and attempted to explore the related mechanism. METHODS: The relative expressions of hsa-circ-000881, miR-665, and PRICKLE2 were detected by RT-qPCR or western blot. Functional assays were conducted to analyze the role of hsa-circ-000881 in the proliferation, migration, and invasion of LUAD cells. A luciferase reporter assay was performed to verify whether hsa-circ-000881, miR-665, and PRICKLE2 interact with each other. RESULTS: Circ-000881 was remarkably downregulated in LUAD. Overexpression of circ-000881 attenuated cell growth, migration, and invasion, whereas its knockdown enhanced the malignancy of LUAD cells. The results of luciferase reporter assay and bioinformatics analysis confirmed that circ-000881 served as a sponge for miR-665, and PRICKLE2 was a direct target of miR-665.Overexpression of miR-665 or silencing of PRICKLE2 abolished circ-000881-mediated inhibition of malignant tumor behavior in LUAD cells. CONCLUSIONS: Circ-000881 has inhibitory effects on LUAD via a miR-665/PRICKLE2 axis, suggesting that circ-000881 may be an underlying therapeutic target for LUAD.

Expression of MiR-608 in Nonsmall Cell Lung Cancer and Molecular Mechanism of Apoptosis and Migration of A549 Cells.

OBJECTIVE: This Work is aimed at exploring the effect of microRNA (MiR)-608 on the function of nonsmall cell lung cancer (NSCLC) A549 cells and related mechanisms. METHODS: Blood samples of 106 NSCLC patients (experimental group) as well as 124 normal people (control group) were selected for relevant investigation. Polymerase chain reaction (PCR) as well as DNA sequencing was used to determine the genotyping of the MiR-608 rs4919510 polymorphism. MiR-608 expression in cells was detected by real-time PCR technology. Western blotting was used to detect changes in protein levels. NSCLC tissues as well as adjacent tissues were explored in 33 patients undergoing surgery. RESULTS: MiR-608 rs4919510 does not influence the incidence of NSCLC patients. In addition, MiR-608 expression was downregulated in the tumor tissue of NSCLC patients, while the transcription factor activating enhancer-binding protein 4 (TFAP4) expression was upregulated. MiR-608 promotes DOX- (Doxorubicin-) induced apoptosis by negatively regulating TFAP4 expression in NSCLC tissue. TFAP4 can significantly inhibit the migration of A549 cells. CONCLUSION: The findings in this investigation can contribute to the effective treatment of NSCLC patients. Also, the investigation can provide some theoretical support for the application of new targets for NSCLC treatment.

Wnt/ß­catenin inhibition reverses multidrug resistance in pediatric acute lymphoblastic leukemia.

Although ~80% of newly diagnosed pediatric patients with acute lymphoblastic leukemia (ALL) become disease­free following appropriate treatment, relapses frequently occur, with dismal prognosis. Therefore, it is urgent to develop novel therapeutic modalities. Resistance to chemotherapy is a major obstacle for the treatment of relapsed ALL. It has been indicated that Wnt pathway is potentially associated with leukemia recurrence. In the current study, a vincristine (VCR)­resistant variant of the human ALL cell line BALL­1 (BALL­1/VCR) that also had relatively specific resistance to both doxorubicin and etoposide was generated. Over­activation of the Wnt/ß­catenin signaling pathway was observed in BALL­1/VCR cells, whereas Dickkopf­related protein 1 selectively suppressed the Wnt signaling pathway and sensitized the response of BALL­1/VCR to anticancer agents. In addition, prednisolone exposure in combination with Wnt inhibition restored chemo­sensitivity in relapsed ALL blasts. Since the resistance of BALL­1/VCR cells is potentially attributed to the overexpression of MDR­associated protein 1 (MRP1), the development of drug resistance in relapsed ALL may associated with the overexpression of MRP1 and P­glycoprotein. The results of this study demonstrated that, as a potential candidate to mimic relapsed ALL, BALL­1/VCR could be used in further research, while Wnt­inhibition may become a promising therapeutic approach for treating ALL.

MicroRNA-148a inhibits cell proliferation and cell cycle progression in lung adenocarcinoma via directly targeting transcription factor E2F3.

MicroRNAs (miRs) serve important roles in various human cancers, including lung adenocarcinoma. Exploring the function and regulatory mechanism of miRs underlying lung adenocarcinoma progression may contribute to identifying novel therapeutic targets and candidates. The present study aimed to examine miR-148a expression and investigate the molecular mechanisms of miR-148a in lung adenocarcinomas. The data from the current study indicated that miR-148a was significantly downregulated in lung adenocarcinoma tissues and cell lines, and low miR-148a expression was significantly associated with advanced Tumor, Node, Metastasis stages and lymph node metastasis, as well as the shorter survival time of patients. Increased miR-148a expression markedly decreased the cell proliferation, colony formation and cell cycle progression of H23 and H1975 cells. Transcription factor E2F3 (E2F3) was identified as a target of miR-148a in H23 and H1975 cells. The expression of E2F3 was negatively mediated by miR-148a in H23 and H1975 cells. In addition, E2F3 was significantly upregulated in lung adenocarcinoma tissues and cell lines, and the expression of miR-148a was inversely correlated with E2F3 expression in lung adenocarcinoma tissues. Additional experiments demonstrated that increased E2F3 expression counteracted the inhibitory effects on lung adenocarcinoma cells caused by miR-148a overexpression. In summary, the findings of the current study suggest that miR-148a may have suppressive effects on the proliferation of lung adenocarcinoma cells at least in part through directly targeting E2F3. Therefore, miR-148a may be used as a potential candidate for the treatment of lung adenocarcinoma.

Potential use of microRNA-200c as a prognostic marker in non-small cell lung cancer.

MicroRNAs (miRNAs/miRs) are a class of small, highly conserved non-coding RNAs that can serve either oncogenic or tumor-suppressive roles in a wide variety of tumors. miR-200c is a member of the miR-200 family whose specific role in non-small cell lung cancer (NSCLC) has not yet been elucidated. The purpose of the present study was to detect the expression level of miR-200c in NSCLC, and to analyze its association with clinicopathological factors and patient prognosis. The present study determined the expression levels of miR-200c in 110 tumor samples collected from patients diagnosed with NSCLC who underwent complete tumor resection with regional lymph node dissection, as assessed by reverse transcription-quantitative polymerase chain reaction. The association between the expression level of miR-200c and clinicopathological features and patient prognosis was also analyzed. The results showed that miR-200c overexpression was detected in 66 of the 110 cases and was significantly associated with positive lymph node metastasis (P<0.001). Univariate survival analysis demonstrated that high miR-200c expression, positive lymph node metastasis and advanced Tumor-Node-Metastasis (TNM) classification stage significantly predicted decreased 5-year disease-free survival rates (all P<0.05) and poor 5-year overall survival rates (all P<0.01), respectively. The results of multivariate Cox regression analysis showed that TNM stage and miR-200c expression retained its significance as an independent prognostic factor for unfavorable 5-year disease-free survival rates (P<0.05) and poor 5-year overall survival rates (P<0.01). The present findings suggest that miR-200c overexpression is significantly associated with poor survival rates in NSCLC and that miR-200c could play an oncogenic role. miR-200c may have clinical potential as a promising prognostic predictor for patients with NSCLC.

Subxiphoid vs intercostal single-incision video-assisted thoracoscopic surgery for spontaneous pneumothorax: A randomised controlled trial.

INTRODUCTION: The conventional video-assisted thoracoscopic surgery (VATS) is performed through the intercostals incisions. In this study, we reported our current experience of thoracoscopic surgery using a subxiphoid single-incision and compared it with the intercostal uniport VATS in the operation time and postoperative pain for spontaneous pneumothorax. METHODS: From July 2014 to September 2015, 43 consecutive patients with spontaneous pneumothorax underwent the unilateral or bilateral bullectomy vie VATS. Among these, 22 patients were treated by the subxiphoid single-incision VATS, and 21 patients were treated using the conventional intercostals uniport VATS. The duration of operation, hospital stay days and inpatient pain scores were compared between each group. RESULTS: The postoperative pain scores on postoperative days (POD) 0, 1, 2 and 3 were significantly lower for patients who underwent the subxiphoid single-incision VATS than those who underwent the intercostal uniport VATS (p < 0.05). However, the subxiphoid single-incision VATS needed longer surgical time than the intercostal uniport VATS (p < 0.001). DISCUSSION: The subxiphoid uniport VATS could decrease the postoperative pain and was safe and effective for performing the unilateral or bilateral bullectomy, but, demanded longer surgical time comparing with the intercostal uniport VATS. CONCLUSIONS: Subxiphoid single-incision VATS, as a new method for bullectomy, could provide a good choice of the incision position for these young patients with spontaneous pneumothorax.

Rotenone induces apoptosis in human lung cancer cells by regulating autophagic flux.

Reactive oxygen species (ROS) are at the center of many physiological and pathological processes. ROS generated due to oxidative stress can potentiate both cancer initiation and progression. Rotenone, which is an inhibitor of the mitochondrial electron transport chain complex I, results in the activation of NOX2 and release of ROS, and has been shown to display anticancer activity through the induction of apoptosis in various cancer cells. The mechanistic link between rotenone-dependent activation of NOX2 and induction of apoptosis is still elusive. In this study, we used the human lung cancer A549 cells to study the molecular mechanism(s) involved between rotenone-dependent activation of NOX2 and impairment of autophagic machinery. We report that acute exposure to rotenone induced mild NOX2-dependnet oxidative stress, which impaired the autophagic flux, resulting in cytosolic accumulation of LC3 and p62/STSQM1. We further show that this induction occurs through the PI3K/Akt/mTORC1 signaling pathway. We furthermore show that chronic exposure to rotenone lead to excessive NOX2-dependent ROS generation, increases autophagy, and decreases p62 level via increased-autophagic flux. Taken together, this study is the first mechanistic elucidation of how rotenone can be used to potently target cancer cells without overhauling the entire cellular machinery. © 2016 IUBMB Life 68(5):388-393, 2016.

Clinicopathological and prognostic significance of metastasis-associated protein 1 expression and its correlation with angiogenesis in lung invasive adenocarcinomas, based on the 2011 IASLC/ATS/ERS classification.

Based on previous findings regarding the angiogenic activities and prognostic roles of metastasis-associated protein 1 (MTA1) in early-stage non-small cell lung cancer, the clinicopathological and prognostic significance of MTA1 protein expression, and its correlation with angiogenesis in lung invasive adenocarcinoma, were further assessed in the present study, according to the 2011 International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification. High protein expression levels of MTA1 were commonly observed in patients with lung invasive adenocarcinoma, and were significantly correlated with tumor size (P=0.030), lymph node metastasis (P=0.021) and microvessel density (P=0.015). Survival analysis demonstrated that patients with high protein expression levels of MTA1 exhibited significantly shorter five-year disease-free and overall survival than those patients whose protein expression levels of MTA1 were low (24.5% vs. 48.7%, P=0.001, and 34.7% vs. 59.2%, P=0.005, respectively). In addition, Cox regression multivariate analysis demonstrated that high protein expression levels of MTA1 significantly correlated with unfavorable five-year disease-free survival (P=0.024). These findings indicate that MTA1 protein expression may possess clinical potential as an indicator of progressive phenotype. Therefore, MTA1 is a promising prognostic predictor to identify subgroups of patients with high risk of relapse, and a potentially novel therapeutic target for antiangiogenesis in patients with lung invasive adenocarcinoma.

Regulator of G-protein signaling 4: A novel tumor suppressor with prognostic significance in non-small cell lung cancer.

Regulator of G-protein signaling (RGS) family members are regulatory molecules which act as GTPase activating proteins (GAPs) for G alpha subunits of heterotrimeric G proteins. Emerging data indicated that RGS members were involved with tumorigenesis and metastasis. In the current study, we identified RGS4 as a novel tumor suppressor with prognostic significance in non-small cell lung cancer (NSCLC). To be specific, we found that RGS4 expression was higher in normal lung tissues than NSCLC specimens (P = 0.003). Further studies demonstrated that RGS4 was generally down-regulated in NSCLC specimens compared with the matched normal lung tissues, both at mRNA and protein levels. In addition, correlational analysis indicated that RGS4 expression levels negatively correlated with lymph node metastasis (P = 0.009) and TNM stage (P = 0.008). Survival analysis demonstrated that patients with lower RGS4 protein expression exhibited a much worse 5-year overall survival and 5-year disease-free survival than those with high expression. More importantly, we proved that over-expression of RGS4 in NSCLC cells decreased invasion and migration due to inhibition of MMP2/9 and reversal of EMT while down-regulation of RGS4 in normal lung cell lines promoted invasion and migration. At last, nude mice metastatic model proved that over-expression of RGS4 suppressed tumor metastasis in vivo. All of these results confirmed the critical role of RGS4 in NSCLC progression.

NCOA5 low expression correlates with survival in esophageal squamous cell carcinoma.

The nuclear receptor coactivator 5 (NCOA5) was a unique coactivator independent of AF2 that can modulate ERα-mediated transcription. Recent researches have indicated that its downregulation may participate in cancer development and progression. The aims of the present study were to investigate NCOA5 expression in esophageal squamous cell carcinoma (ESCC) and validate its possible influence on patients' prognosis. NCOA5 expression was examined by immunohistochemical staining in 119 ESCC patients' tissues. Ten paired tumor and adjacent normal specimens were examined by Western blot analysis. Statistical analysis was performed to assess its relevance with various clinicopathologic features and its influence on patients' survival. By immunohistochemistry analysis, NCOA5 expression was found to be significantly correlated with differentiation (P = 0.039), T status (P = 0.047) and stage (P = 0.036). Furthermore, we found NCOA5 higher expression in normal tissues than in tumor tissues by Western blot analysis. Univariate analysis showed that poor differentiation (P = 0.035, P = 0.027), lymph node metastasis (P < 0.001, P < 0.001), high T status (P = 0.010, P = 0.012), advanced stage (P < 0.001, P < 0.001) and NCOA5 low expression (P < 0.001, P < 0.001) were significantly correlated with poor prognosis of both disease-free survival (DFS) and overall survival (OS). Multivariate analysis showed that NCOA5 low expression (P = 0.019, P = 0.047), high T status (P = 0.015, P = 0.012), lymph node metastasis (P = 0.040, P = 0.021) and advanced stage (P = 0.017, P = 0.046) were independent prognostic factors of poor DFS and OS. Our findings suggest that NCOA5 low expression is associated with ESCC progression and is a potential biomarker in predicting poor prognosis. Further studies of NCOA5 may help develop new therapeutic strategies against ESCC.

Expression of THOP1 and its relationship to prognosis in non-small cell lung cancer.

BACKGROUND: The study was designed to detect the expression level of thimet oligopeptidase (THOP1) protein in non-small cell lung cancer (NSCLC) and investigate its correlation with clinicopathologic features and prognosis. METHODS: Immunohistochemical staining was used to determine the expression of THOP1 protein in 120 NSCLC specimens and 53 distant normal lung tissues. Quantitative real-time PCR and western blotting were employed to measure the expression of THOP1 in 16 pairs of primary NSCLC and corresponding normal tissues. RESULTS: Analysis of immunohistochemical staining suggested low THOP1 expression was found in 71 (59.2%) of the 120 NSCLC specimens and significantly correlated with positive lymph node metastasis (P = 0.048). However, low THOP1 expression was found in 22 (41.5%) of the 53 normal lung tissues. Chi-square test suggested that the expression of THOP1 was significantly higher in the normal lung tissues than that in the NSCLC specimens (P = 0.032). Real-Time PCR and western blotting showed that NSCLC specimens had decreased THOP1 mRNA and protein expression compared to corresponding normal tissues. Univariate analysis demonstrated that low THOP1 expression significantly predicted decreased 5-year disease-free survival (P = 0.038) and overall survival (P = 0.017). In addition, positive lymph node metastasis (P = 0.025) and advanced TNM stage (P = 0.009) significantly predicted decreased 5-year overall survival. However, multivariate Cox regression analysis showed that only low THOP1 expression retained its significance as an independent prognostic factor for unfavorable 5-year disease-free survival (P = 0.046) and overall survival (P = 0.021). CONCLUSIONS: THOP1 may have clinical potentials to be employed as a promising biomarker to identify individuals with better prognosis and a novel antitumor agent for therapy of patients with NSCLC.

Retinoblastoma binding protein 2 (RBP2) promotes HIF-1α-VEGF-induced angiogenesis of non-small cell lung cancer via the Akt pathway.

BACKGROUND: Pathological angiogenesis plays an essential role in tumor aggressiveness and leads to unfavorable prognosis. The aim of this study is to detect the potential role of Retinoblastoma binding protein 2 (RBP2) in the tumor angiogenesis of non-small cell lung cancer (NSCLC). METHODS: Immunohistochemical staining was used to detect the expression of RBP2, hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF) and CD34. Two pairs of siRNA sequences and pcDNA3-HA-RBP2 were used to down-regulate and up-regulate RBP2 expression in H1975 and SK-MES-1 cells. An endothelial cell tube formation assay, VEGF enzyme-linked immunosorbent assay, real-time PCR and western blotting were performed to detect the potential mechanisms mediated by RBP2 in tumor angiogenesis. RESULTS: Of the 102 stage I NSCLC specimens analyzed, high RBP2 protein expression is closely associated with tumor size (P = 0.030), high HIF-1α expression (P = 0.028), high VEGF expression (P = 0.048), increased tumor angiogenesis (P = 0.033) and poor prognosis (P = 0.037); high MVD was associated with high HIF-1α expression (P = 0.034), high VEGF expression (P = 0.001) and poor prognosis (P = 0.040). Multivariate analysis indicated that RBP2 had an independent influence on the survival of patients with stage I NSCLC (P = 0.044). By modulating the expression of RBP2, our findings suggested that RBP2 protein depletion decreased HUVECs tube formation by down-regulating VEGF in a conditioned medium. RBP2 stimulated the up-regulation of VEGF, which was dependent on HIF-1α, and activated the HIF-1α via phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Moreover, VEGF increased the activation of Akt regulated by RBP2. CONCLUSIONS: The RBP2 protein may stimulate HIF-1α expression via the activation of the PI3K/Akt signaling pathway under normoxia and then stimulate VEGF expression. These findings indicate that RBP2 may play a critical role in tumor angiogenesis and serve as an attractive therapeutic target against tumor aggressiveness for early-stage NSCLC patients.

GOLPH3, a good prognostic indicator in early-stage NSCLC related to tumor angiogenesis.

BACKGROUND: Golgi phosphoprotein-3 (GOLPH3) is implicated in cancer development and progression. The aim of this study was to evaluate the prognostic significance of GOLPH3 protein and its association with tumor angiogenesis in patients with early-stage NSCLC. MATERIALS AND METHODS: Immunohistochemistry was performed to determine GOLPH3 protein expression and allow assessment of intratumoral microvessel density (MVD) by counting CD-34 positive immunostained endothelial cells. Correlations of expression with MVD, clinicopathologic features and clinical prognosis were analyzed. RESULTS: A notably higher level of GOLPH3 expression was found in early-stage NSCC tissues at the protein level. However, we do not find any correlation between GOLPH3 expression and clinicopathologic features (p>0.05), although higher MVD was positively associated with GOLPH3 overexpression (p<0.001). Expression of GOLPH3 was found to be an independent prognostic factor in early- stage NSCLC patients, those expressing high levels of GOLPH3 exhibiting a substantially lower 5-year overall survival than GOLPH3-negative patients (adjusted HR =1.899, 95% CI: 1.021-3.532, p=0.043). CONCLUSIONS: High expression of the GOLPH3 protein is common in early-stage NSCC, and is closely associated with tumor progression, increased tumor angiogenesis, and poor survival. We conclude a possibility of its use as a diagnostic and prognostic marker in early-stage NSCC patients.

Overexpression of LAPTM4B is correlated with tumor angiogenesis and poor prognosis in non-small cell lung cancer.

Lysosome-associated protein transmembrane-4 beta (LAPTM4B) is a novel oncogene, which has been indicated to be dramatically overexpressed in various malignant tumors. The aims of this study were to detect LAPTM4B protein expression in patients with non-small cell lung cancer (NSCLC) and then analyze the relationships of LAPTM4B protein with clinicopathologic factors, tumor angiogenesis and prognosis with SPSS statistical software. Immunohistochemistry was used to examine the expression of LAPTM4B and CD34 proteins in NSCLC tissues, and its results showed that LAPTM4B protein expression in NSCLC tissues was significantly higher than that in normal lung tissues (P < 0.001). Of the186 NSCLC cases, 129 (69.35 %) had strong expression of LAPTM4B protein, which was associated with histopathologic differentiation (P = 0.017), lymph node metastasis (P = 0.001) and TNM stage (P = 0.046), as well as the microvessel density (MVD) (P = 0.019). Kaplan-Meier survival analysis revealed that patients with strong LAPM4B protein expression and high MVD might have poor overall survival (OS; P = 0.001, P = 0.002, respectively) and disease-free survival (DFS; P = 0.002, P = 0.038, respectively). Multivariate analysis demonstrated that LAPTM4B protein was an independent prognostic marker for OS and DFS of NSCLC patients (P = 0.037, P = 0.046, respectively). These findings illustrated that LAPTM4B protein was closely associated with NSCLC progression, angiogenesis and poor prognosis, suggesting that LAPTM4B protein could be applied not only in predicting patient's outcome, but also in antiangiogenic therapy as a possible novel target molecule.