FOXF1 promotes tumor vessel normalization and prevents lung cancer progression through FZD4.

Cancer cells re-program normal lung endothelial cells (EC) into tumor-associated endothelial cells (TEC) that form leaky vessels supporting carcinogenesis. Transcriptional regulators that control the reprogramming of EC into TEC are poorly understood. We identified Forkhead box F1 (FOXF1) as a critical regulator of EC-to-TEC transition. FOXF1 was highly expressed in normal lung vasculature but was decreased in TEC within non-small cell lung cancers (NSCLC). Low FOXF1 correlated with poor overall survival of NSCLC patients. In mice, endothelial-specific deletion of FOXF1 decreased pericyte coverage, increased vessel permeability and hypoxia, and promoted lung tumor growth and metastasis. Endothelial-specific overexpression of FOXF1 normalized tumor vessels and inhibited the progression of lung cancer. FOXF1 deficiency decreased Wnt/ß-catenin signaling in TECs through direct transcriptional activation of Fzd4. Restoring FZD4 expression in FOXF1-deficient TECs through endothelial-specific nanoparticle delivery of Fzd4 cDNA rescued Wnt/ß-catenin signaling in TECs, normalized tumor vessels and inhibited the progression of lung cancer. Altogether, FOXF1 increases tumor vessel stability, and inhibits lung cancer progression by stimulating FZD4/Wnt/ß-catenin signaling in TECs. Nanoparticle delivery of FZD4 cDNA has promise for future therapies in NSCLC.

ILT4 facilitates angiogenesis in non-small cell lung cancer.

Antiangiogenic therapy targeting VEGF-A has become the standard of first-line therapy for non-small cell lung cancer (NSCLC). However, its clinical response rate is still less than 50%, and most patients eventually develop resistance, even when using combination therapy with chemotherapy. The major cause of resistance is the activation of complex bypass signals that induce angiogenesis and tumor progression. Therefore, exploring novel proangiogenic mechanisms and developing promising targets for combination therapy are crucial for improving the efficacy of antiangiogenic therapy. Immunoglobulin-like transcript (ILT) 4 is a classic immunosuppressive molecule that inhibits myeloid cell activation. Recent studies have shown that tumor cell-derived ILT4 drives tumor progression via the induction of malignant biologies and creation of an immunosuppressive microenvironment. However, whether and how ILT4 participates in NSCLC angiogenesis remain elusive. Herein, we found that enriched ILT4 in NSCLC is positively correlated with high microvessel density, advanced disease, and poor overall survival. Tumor cell-derived ILT4 induced angiogenesis both in vitro and in vivo and tumor progression and metastasis in vivo. Mechanistically, ILT4 was upregulated by its ligand angiopoietin-like protein 2 (ANGPTL2). Their interaction subsequently activated the ERK1/2 signaling pathway to increase the secretion of the proangiogenic factors VEGF-A and MMP-9, which are responsible for NSCLC angiogenesis. Our study explored a novel mechanism for ILT4-induced tumor progression and provided a potential target for antiangiogenic therapy in NSCLC.

Luteolin inhibits viability, migration, angiogenesis and invasion of non-small cell lung cancer vascular endothelial cells via miR-133a-3p/purine rich element binding protein B-mediated MAPK and PI3K/Akt signaling pathways.

Luteolin inhibits tumorigenesis of non-small cell lung cancer (NSCLC), but its mechanism still needs to be clarified. We hereby explored the effects of luteolin in vascular endothelial cells of NSCLC (NSCLC-VECs). After extraction and identification of NSCLC-VECs, cells were treated with luteolin and transfected. The viability, migration, angiogenesis and invasion of the cells were measured. The levels of miR-133a-3p, purine rich element binding protein B (PURB), vascular endothelial growth factor (VEGF), phosphatidylinositol 3-kinase (PI3K), Akt, mitogen-activated protein kinases (MAPK), matrix metalloproteinase (MMP)-2/-9 were determined. The interaction relationship of miR-133a-3p and PURB was identified. Luteolin inhibited the viability, migration, angiogenesis and invasion of NSCLC-VECs yet up-regulated miR-133a-3p level, while miR-133a-3p inhibitor counteracted the repressive effect of luteolin on the viability, migration, angiogenesis, and invasion in NSCLC-VECs. Luteolin inhibited the expressions of migration- and invasion-associated proteins (VEGF, MMP-2 and MMP-9), PI3K/Akt and MAPK signaling pathways-related factors, while miR-133a-3p inhibitor reversed the inhibitory effect of Luteolin on NSCLC-VECs. Luteolin decreased the level of PURB, which was targeted by miR-133a-3p. ShPURB promoted miR-133a-3p level in NSCLC-VECs, while reversing the promoting effects of miR-133a-3p inhibitor on the migration, invasion, and levels of migration- and invasion-associated proteins, PI3K/Akt and MAPK pathways-associated factors in NSCLC-VECs. Collectively speaking, luteolin inhibits the migration and invasion of NSCLC-VECs via miR-133a-3p/PURB- mediated MAPK and PI3K/Akt pathways.

Predictive value of microvascular density for response to anlotinib in advanced NSCLC.

ABSTRACT: Nonsmall cell lung cancer (NSCLC) is the most common type of lung cancer. This study aimed to categorize the microvessels in advanced NSCLC and determine the relationship between intratumoral microvascular density (MVD) and the efficacy of anlotinib for NSCLC.The clinical data of 68 patients receiving anlotinib as third-line treatment or beyond for advanced NSCLC were retrospectively collected. Microvessels were stained for CD31 and CD34 by using immunohistochemical staining and were classified as undifferentiated (CD31+ CD34-) and differentiated vessels (CD31+ CD34+). The relationship between MVD and anlotinib efficacy and patient prognosis was analyzed.Patients were divided into the high or low MVD groups according to the median MVD of differentiated (9.4 vessels/field) and undifferentiated microvessels (6.5 vessels/field). There were significantly more patients with high undifferentiated-vessel MVD in the disease control group than in the disease progression group (72.7% vs 16.7%, P < .001). Patients with high undifferentiated-vessel MVD had significantly longer median progression-free survival than those with low undifferentiated-vessel MVD (7.1 vs 3.7 months, P < .001).Anlotinib as third- or beyond line therapy is safe and effective for advanced NSCLC. Patients with a higher density of undifferentiated microvessels have better response to anlotinib and longer progression-free survival.

Angiogenesis inhibition in lung cancer: emerging novel strategies.

PURPOSE OF REVIEW: In the current review, we will explore the molecular bases that have determined the design of clinical trials exploring the efficacy of antivascular agents in combination with chemotherapy, immune check point inhibitors and epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in patients with advanced nonsmall cell lung cancer. RECENT FINDINGS: Recent clinical trials have demonstrated the synergistic effect of antivascular agents with immune checkpoint inhibitors and EGFR-TKIs, despite no molecular marker has been identified yet to select patients. SUMMARY: Lung cancer remains one of the first causes of cancer-related death. However, thanks to the development of stratified molecular medicine and the introduction of immune checkpoint inhibitors, patients' survival has significantly improved. Due to the critical role of pro-angiogenic factors in cancer progression, antivascular agents targeting the vascular endothelial growth factor (VEGF) and its receptor (VEGFR) have been developed. Their efficacy has been explored in combination with chemotherapy, and immune checkpoint inhibitors, with promising but not definitive conclusions about their impact on prolonging patients' survival.

Tumor-derived exosomal miR-3157-3p promotes angiogenesis, vascular permeability and metastasis by targeting TIMP/KLF2 in non-small cell lung cancer.

Metastasis is the main cause of death in patients with advanced lung cancer. The exosomes released by cancer cells create tumor microenvironment, and then accelerate tumor metastasis. Cancer-derived exosomes are considered to be the main driving force for metastasis niche formation at foreign sites, but the mechanism in Non-small cell lung carcinoma (NSCLC) is unclear. In metastatic NSCLC patients, the expression level of miR-3157-3p in circulating exosomes was significantly higher than that of non-metastatic NSCLC patients. Here, we found that miR-3157-3p can be transferred from NSCLC cells to vascular endothelial cells through exosomes. Our work indicates that exosome miR-3157-3p is involved in the formation of pre-metastatic niche formation before tumor metastasis and may be used as a blood-based biomarker for NSCLC metastasis. Exosome miR-3157-3p has regulated the expression of VEGF/MMP2/MMP9 and occludin in endothelial cells by targeting TIMP/KLF2, thereby promoted angiogenesis and increased vascular permeability. In addition, exosome miR-3157-3p promoted the metastasis of NSCLC in vivo.

Thalidomide suppresses angiogenesis and immune evasion via lncRNA FGD5-AS1/miR-454-3p/ZEB1 axis-mediated VEGFA expression and PD-1/PD-L1 checkpoint in NSCLC.

BACKGROUND: Non-small cell lung cancer (NSCLC) accounts for about 80-85% of total lung cancer cases. Identifying the molecular mechanisms of anti-tumor drugs is essential for improving therapeutic effects. Herein, we aim to investigate the role of thalidomide in the tumorigenicity of NSCLC. METHODS: The A549 xenograft nude mouse model was established to explore therapeutic effects of thalidomide. The expression of FGD5-AS1 was evaluated in carcinomatous and paracarcinomatous tissues from NSCLC patients as well as NSCLC cell lines. CCK-8 assay was performed to assess cell viability. The invasive capacity was examined using transwell assay. The tube formation assay was applied to determine cell angiogenesis. Flow cytometry was subjected to validate CD8+ T cell activity. The FGD5-AS1/miR-454-3p/ZEB1 regulatory network was analyzed using luciferase reporter, RIP and ChIP assays. RESULTS: Thalidomide reduced tumor growth and angiogenesis and increased CD8+ T cell ratio in a mouse model. Enhanced expression of FGD5-AS1 was positively correlated with the poor survival of NSCLC patients. Knockdown of FGD5-AS1 notably suppressed the proliferation, invasion and angiogenesis of cancer cells as well as the apoptosis of CD8+ T cells. Thalidomide targeted FGD5-AS1 to exert its anti-tumor activity in NSCLC. FGD5-AS1 acted as a sponge of miR-454-3p to upregulate ZEB1, thus increasing the expression of PD-L1 and VEGFA. Simultaneous overexpression of FGD5-AS1 and silencing of miR-454-3p reversed thalidomide-mediated anti-tumor effects in NSCLC. CONCLUSION: Thalidomide inhibits NSCLC angiogenesis and immune evasion via FGD5-AS1/miR-454-3p/ZEB1 axis-mediated regulation of VEGFA expression and PD-1/PD-L1 checkpoint.

Inhibitory effects of terrein on lung cancer cell metastasis and angiogenesis.

Cancer metastasis is the leading cause of mortality in cancer patients. Over 70% of lung cancer patients are diagnosed at advanced or metastatic stages, and this results in an increased incidence of mortality. Terrein is a secondary bioactive fungal metabolite isolated from Aspergillus terreus. Numerous studies have demonstrated that terrein has anticancer properties, but in the present study, the cellular mechanisms underlying the inhibition of lung cancer cell metastasis by terrein was investigated for the first time. Using MTT assays, the cytotoxic effects of terrein were first examined in human lung cancer cells (A549 cells) and then compared with its cytotoxic effects in three noncancer control cell lines (Vero kidney, L6 skeletal muscle and H9C2 cardiomyoblast cells). The results indicated that terrein significantly reduced the viability of all these cells but exhibited a different level of toxicity in each cell type; these results revealed a specific concentration range in which the effect of terrein was specific to A549 cells. This significant cytotoxic effect of terrein in A549 cells was verified using LDH assays. It was then demonstrated that terrein attenuated the proliferation of A549 cells using IncuCyte image analysis. Regarding its antimetastatic effects, terrein significantly inhibited A549 cell adhesion, migration and invasion. In addition, terrein suppressed the angiogenic processes of A549 cells, including vascular endothelial growth factor (VEGF) secretion, capillary­like tube formation and VEGF/VEGFR2 interaction. These phenomena were accompanied by reduced protein levels of integrins, FAK, and their downstream mediators (e.g., PI3K, AKT, mTORC1 and P70S6K). All these data indicated that terrein was able to inhibit all the major metastatic processes in human lung cancer cells, which is crucial for cancer treatment.

Perifocal edema volume is not associated with immunohistochemical features reflecting proliferation potential, microvessel density, neoangiogenesis and invasiveness in brain metastasis.

OBJECTIVE: Perifocal edema of brain tumors is associated with survival and neurological symptoms. Our aim was to analyze associations between perifocal edema and immunohistochemical features including proliferation potential, microvessel density, neoangiogenesis and invasiveness in brain metastasis (BM). METHODS: 35 patients with BM were included into the retrospective study. The tumors were localized supratentorial in 25 lesions (71.4%) and infratentorial in 10 lesions (28.6%). The following immunohistochemical features were calculated on histopathological specimens: microvessel density, proliferation index Ki 67, matrix-metallopeptidase 9 (MMP9) extracellular matrix metalloproteinase inducer (EMMPRIN) and vascular endothelial growth factor (VEGF) expression. Tumor and edema volumes were estimated semiautomatically on magnetic resonance images. RESULTS: There were no correlations between tumor volume and edema volume. Moreover, no correlation was identified between the investigated immunohistochemical features and tumor/edema volume. In the non-small cell lung cancer subgroup, a positive correlation between tumor volume and VEGF expression was observed (r = 0.52, P = 0.02) and edema volume correlated inversely with MMP9 expression (r = -0.53, P = 0.02). CONCLUSION: In BM, no linear associations exist between tumor volumes, edema volumes and immunohistochemical features reflecting proliferation potential, neoangiogenesis, microvessel density and MMP9 expression. However, in the subgroup of non-small cell lung cancer, there might be associations between MMP9 expression and edema volume as well as between tumor volume and angiogenesis.

Lobectomy With Artery Reconstruction and Pneumonectomy for Non-Small Cell Lung Cancer: A Propensity Score Weighting Study.

BACKGROUND: The treatment of non-small cell lung cancer is based, when suitable, on surgical resection. Pneumonectomy has been considered the standard surgical procedure for locally advanced lung cancers but it is associated with high mortality and morbidity rates. Reconstruction of the pulmonary artery, associated with parenchyma-sparing techniques, is meant to be an alternative to pneumonectomy. METHODS: This retrospective single-center study is based on a detailed and comprehensive analysis of the clinical and oncologic data of patients treated between 2004 and 2016 through pneumonectomy or lobectomy with reconstruction of the pulmonary artery. A propensity score weighting approach, based on the preoperative characteristics of two groups of 124 patients each was performed. The subsequent statistical analysis evaluated long-term and short-term clinical outcomes together with risk factors analysis. RESULTS: The comparison between pneumonectomy and pulmonary artery reconstructions showed a higher 30-day (P = .02) and 90-day (P = .03) mortality rate in the pneumonectomy group, together with a higher incidence of major complications (P = .004). Long-term results have shown comparable outcomes, both in terms of 5-year disease-free survival (52.2% for pneumonectomy vs 46% for pulmonary artery reconstructions, P = .57) and overall 5-year survival (41.9% vs 35.6%, respectively; P = .57). Risk factors analysis showed that cancer-specific survival was related to lymph node status (P < .01) and absence of adjuvant therapy (P = .04). Lymph node status also influenced the risk of recurrence (P < .01). CONCLUSIONS: Lobectomy with reconstruction of the pulmonary artery is a valuable and oncologically safe alternative to pneumonectomy, with lower short-term mortality and morbidity, without affecting long-term oncologic results.

MicroRNA-20a-5p suppresses tumor angiogenesis of non-small cell lung cancer through RRM2-mediated PI3K/Akt signaling pathway.

The current therapeutic strategies for non-small cell lung cancer (NSCLC) are limited and unsatisfactory. MicroRNAs (miRNAs) participate in tumor angiogenesis in NSCLC. The aim of this study was to investigate the role of miR-20a-5p (miR-20a) in human NSCLC metastasis. In the current study, bioinformatics analysis and RT-PCR were performed to examine the expression level of miR-20a in tissues of NSCLC patients and NSCLC cell lines, respectively. Western blot was performed to test the protein levels. Cell proliferation, migration and angiogenesis capacity were tested by 5-ethynyl-29-deoxyuridine (EdU) assay, transwell assay and tube formation assay, respectively. Dual-luciferase reporter assay (DLR) was used to confirm the interaction between miR-20a and paired ribonucleotide reductase regulatory subunit M2 (RRM2). We found that the expression of RRM2 was upregulated, while the expression of miR-20a was downregulated in cancer tissues compared with adjacent tissues in NSCLC patients. We also detected the expression level of RRM2 and miR-20a in NSCLC cell lines, showing A549 cell line exhibited the lowest expression level of miR-20a and highest expression level of RRM2. Overexpressed miR-20a not only dramatically suppressed NSCLC cells proliferation, endothelial cells migration and tube formation in vitro, but also inhibited tumor growth and angiogenesis in vivo. It was demonstrated that miR-20a suppressed NSCLC growth by inhibiting RRM2-mediated PI3K/Akt signaling pathway. These findings indicate that the novel identified miR-20a could function as a tumor suppressor in NSCLC through modulating the RRM2-mediated PI3K/Akt axis, and it could be a valid molecular target for NSCLC treatment.

LncRNA EPIC1 promotes tumor angiogenesis via activating the Ang2/Tie2 axis in non-small cell lung cancer.

AIMS: Non-small cell lung cancer (NSCLC) is considered a highly fatal tumor. Importantly, angiogenesis is critical for tumor progression. Long non-coding RNAs (lncRNAs), which are untranslatable, control cell functions through different pathways. lncRNA EPIC1 has been reported to promote cell viability, cell cycle progression, and invasion. However, the relationship between EPIC1 and tumor angiogenesis remains an enigma. We explored the role of EPIC1 in tumor angiogenesis in NSCLC. MATERIALS AND METHODS: First, EPIC1 expression was analyzed using the GEPIA database and was further verified using qPCR in tumor tissues from patients with NSCLC and NSCLC cell lines. Next, EPIC1 function was detected using loss-of-function and gain-of-function assays. Moreover, EdU staining, flow cytometry, and channel formation assays were performed to assess HUVEC proliferation and channel the formation in the NSCLC-HUVEC transwell co-culture system. KEY FINDINGS: EPIC1 expression was significantly upregulated in NSCLC tissues and cell lines. Furthermore, the overexpression of EPIC1 in NSCLC cells stimulated HUVEC channel formation and proliferation by activating Ang2/Tie2 signaling, and the opposite results were obtained when EPIC1 was silenced in NSCLC cells. The density of new blood vessels was simultaneously increased by EPIC1 overexpression in vivo, using CAM angiogenesis model and a nude mouse tumor model. Finally, all these experimental findings could be established in the samples from patients with NSCLC. We postulate that EPIC1 promotes tumor angiogenesis by activating the Ang2/Tie2 axis in NSCLC. SIGNIFICANCE: Elucidating the molecular and cellular mechanisms of EPIC1 in tumor angiogenesis provides a novel perspective on NSCLC clinical therapy.

Pretreatment to Posttreatment Hypoxia Inducible Factor-1α Ratios as a Potentially Predictive Marker for First-Line Treatment in Nonsmall Cell Lung Cancer Patients without Known Driver Mutations.

Background: Hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) are key angiogenic regulatory factors. The aim of this study was to identify the most useful prognostic angiogenic factors in advanced nonsmall cell lung cancer (NSCLC) without known driver gene mutations. Methods: Eligible patients were pathologically confirmed to have advanced NSCLC without known driver mutations. All patients were treated with standard first-line chemotherapy ± bevacizumab. Serum concentrations of HIF-1α, VEGF, sVEGFR1, sVEGFR2, and endostatin were measured via enzyme-linked immunosorbent assays (ELISAs) prior to and after two cycles of treatment. Area under the curve (AUC) and optimal cutoff values were calculated by receiver operator characteristic curve (ROC) analyses. The parameters that predicted survival were evaluated by univariate and multivariate Cox proportional hazard analyses. Results: A total of 47 patients were included in this study. HIF-1α levels decreased significantly after treatment in the nonprogressing (partial response/stable disease) patient group (707.94 vs. 355.53 pg/mL, p = 0.002), but increased levels were seen in patients with progressive disease, however, the extent of change did not reach significance (173.70 vs. 416.34 pg/mL, p = 0.078). An HIF-1α ratio of 1.18 was chosen as the best point to predict treatment response through ROC analyses. Via univariate and multivariate analyses, we found that patients with a HIF-1α ratio ≥1.18 after treatment were significantly more likely to have a prolonged progression-free survival (PFS, HR 0.303, 95% CI: 0.153-0.603, p = 0.001) and overall survival (OS, HR 0.436, 95% CI: 0.153-0.603, p = 0.025). Conclusions: We identified the pretreatment to posttreatment HIF-1α ratio as a promising predictor for PFS and OS in NSCLC patients without known driver mutations.

MITF functions as a tumor suppressor in non-small cell lung cancer beyond the canonically oncogenic role.

Microphthalamia-associated transcription factor (MITF) is a critical mediator in melanocyte differentiation and exerts oncogenic functions in melanoma progression. However, the role of MITF in non-small cell lung cancer (NSCLC) is still unknown. We found that MITF is dominantly expressed in the low-invasive CL1-0 lung adenocarcinoma cells and paired adjacent normal lung tissues. MITF expression is significantly associated with better overall survival and disease-free survival in NSCLC and serves as an independent prognostic marker. Silencing MITF promotes tumor cell migration, invasion and colony formation in lung adenocarcinoma cells. In xenograft mouse model, MITF knockdown enhances metastasis and tumorigenesis, but decreases angiogenesis in the Matrigel plug assay. Whole transcriptome profiling of the landscape of MITF regulation in lung adenocarcinoma indicates that MITF is involved in cell development, cell cycle, inflammation and WNT signaling pathways. Chromatin immunoprecipitation assays revealed that MITF targets the promoters of FZD7, PTGR1 and ANXA1. Moreover, silencing FZD7 reduces the invasiveness that is promoted by silencing MITF. Strikingly, MITF has significantly inverse correlations with the expression of its downstream genes in lung adenocarcinoma. In summary, we demonstrate the suppressive role of MITF in lung cancer progression, which is opposite to the canonical oncogenic function of MITF in melanoma.

[Prognostic Analysis of NSCLC Based on the Tumor-associated Macrophages, Tumor Neo-vessels and PD-L1 Expression in Tumor Microenvironment].

BACKGROUND: Tumor microenvironment is a complex and dynamic community, which plays a crucial role in tumor progression via the co-evolution of cancer cells and tumor stroma. Among them, tumor-associated macrophages (TAMs) and tumor neo-vessels are two key components in the tumor microenvironment during cancer invasion. In addition, programmed cell death ligand 1/programmed cell death ligand 1 (PD-1/PD-L1) also plays an important role in tumorigenesis and development, and the clinical strategies to block PD-1/PD-L1 pathway could have great benefits for cancer patients. This study was aimed at analyzing the quantitative expression and prognostic significance of TAMs, tumor neo-vessels and PD-L1 in tumor microenvironment and exploring the relations between the expression of above components with the patients' prognosis of non-small cell lung cancer (NSCLC). METHODS: Clinico-pathological data and surgical specimens of 92 patients with NSCLC were collected, and immunohistochemistry was used to stain the expression of TAMs, tumor neo-vessels and PD-L1 on tumor tissue and peri-tumor tissues. The inverted microscopy was used to take pictures and Image-pro Plus 6.0 software was used for quantitative analysis. The clinicopathological characteristics and overall survival (OS) were analyzed. RESULTS: The median OS of 92 NSCLC cases was 22.5 month. The expression of TAMs, tumor neo-vessels and PD-L1 in tumor tissue and peri-tumor tissues were not statistically significant (P>0.05). According to the cutoff of above key three components in tumor microenvironment, all the cases could be classified into high, middle and low expression groups. The survival analysis demonstrated that the OS in high expression group of TAMs (P=0.016) and PD-L1 (P=0.002) was shorter than the other two groups, respectively, with statistical significance. The OS in high tumor neo vessels group was shorter than the other two groups. However, there was no statistical significance between these three group (P=0.626). Combined with above the three components, all the cases could be classified into low, middle and high density groups. The survival analysis demonstrated that the median OS of combined high density group was shorter than the other two groups (P=0.001). Multivariate analysis by Cox regression indicated that pathological type, TAMs and PD-L1 expression were the independent prognostic factors. CONCLUSIONS: The key components of TAMs and PD-L1 in tumor microenvironment are closely related to the prognosis of NSCLC patients.

Thrombin is a therapeutic target for non-small-cell lung cancer to inhibit vasculogenic mimicry formation.

Tumor cells transform into endothelial cells by epithelial-to-mesenchymal transition, which is characterized by vasculogenic mimicry (VM). VM not only accelerates tumor progression but also increases drug-induced resistance. However, very little is currently known about the molecular determinants that enable VM. Targeting VM might bring a new breakthrough in cancer treatment. Thrombin is the key enzyme of the blood coagulation system and could contribute to tumor progression. Nevertheless, the association between thrombin and VM formation remains largely unknown. We found that VM was associated with the overall survival of non-small-cell lung cancer (NSCLC) patients, and that thrombin expression was closely related to VM formation. This research revealed that thrombin induced VM formation via PAR-1-mediated NF-κB signaling cascades. The novel thrombin inhibitors r-hirudin and DTIP inhibited VM formation and spontaneous metastases in subcutaneous tumors. Clinical pathological analysis confirmed that NSCLC patients with thrombin-positive/PAR-1-high expression had the poorest prognosis and were the most likely to form VM. The promotional activity of thrombin in VM formation and tumor metastasis was abolished in PAR-1-deficient NSCLC cells. The EGFR inhibitor gefitinib had no effect on VM and increased VEGF expression in tumors. The combination therapy of DTIP and gefitinib achieved a better therapeutic effect than either agent alone. This study is the first to illustrate that thrombin substantially contributes, together with PAR-1, to VM formation and to illustrate that VM might be a target of r-hirudin and DTIP to suppress tumor progression. The anticoagulants r-hirudin and DTIP could be employed for antitumor therapy. Combination therapy with DTIP with an EGFR inhibitor might achieve superior therapeutic effects.

Noninvasive imaging of tumor hypoxia after nanoparticle-mediated tumor vascular disruption.

We have previously demonstrated that endothelial targeting of gold nanoparticles followed by external beam irradiation can cause specific tumor vascular disruption in mouse models of cancer. The induced vascular damage may lead to changes in tumor physiology, including tumor hypoxia, thereby compromising future therapeutic interventions. In this study, we investigate the dynamic changes in tumor hypoxia mediated by targeted gold nanoparticles and clinical radiation therapy (RT). By using noninvasive whole-body fluorescence imaging, tumor hypoxia was measured at baseline, on day 2 and day 13, post-tumor vascular disruption. A 2.5-fold increase (P<0.05) in tumor hypoxia was measured two days after combined therapy, resolving by day 13. In addition, the combination of vascular-targeted gold nanoparticles and radiation therapy resulted in a significant (P<0.05) suppression of tumor growth. This is the first study to demonstrate the tumor hypoxic physiological response and recovery after delivery of vascular-targeted gold nanoparticles followed by clinical radiation therapy in a human non-small cell lung cancer athymic Foxn1nu mouse model.

Baicalein suppresses vasculogenic mimicry through inhibiting RhoA/ROCK expression in lung cancer A549 cell line.

Vasculogenic mimicry (VM) refers to a new tubular network of the blood supply system with abundant extracellular matrix. VM is similar to capillaries but does not involve endothelial cells. As a traditional herbal medicine commonly used in China, baicalein possesses anti-inflammatory and lipoxygenase activities. However, the effects of baicalein on the process of VM formation in non-small cell lung cancer (NSCLC) and the underlying mechanisms have remained poorly understood. In this study, baicalein was found to inhibit the viability and motility of A549 cells and induced the breakage of the cytoskeletal actin filament network. In addition, baicalein significantly decreased the formation of VM and downregulated the expressions of VM-associated factors, such as VE-cadherin, EphA2, MMP14, MMP2, MMP9, PI3K and LAMC2, similar to the effects of ROCK inhibitors. Indeed, baicalein inhibited RhoA/ROCK expression in vitro and in vivo, suggesting the underlying mechanisms of reduced VM formation. Collectively, baicalein suppressed the formation of VM in NSCLC by targeting the RhoA/ROCK signaling pathway, indicating that baicalein might serve as an emerging drug for NSCLC.

Upregulation of annexin A1 protein expression in the intratumoral vasculature of human non-small-cell lung carcinoma and rodent tumor models.

Annexin A1 (anxA1) is an immunomodulatory protein that has been proposed as a tumor vascular target for antitumor biologic agents, yet to date the vascular expression of anxA1 in specific tumor indications has not been systematically assessed. Attempts to evaluate vascular anxA1 expression by immunohistochemistry are complicated by a lack of available antibodies that are both specific for anxA1 and bind the N-terminal-truncated form of anxA1 that has previously been identified in tumor vasculature. To study the vascular expression pattern of anxA1 in non-small-cell lung carcinoma (NSCLC), we isolated an antibody capable of binding N-terminal-truncated anxA127-346 and employed it in immunohistochemical studies of human lung specimens. Lung tumor specimens evaluated with this antibody revealed vascular (endothelial) anxA1 expression in five of eight tumor samples studied, but no vascular anxA1 expression was observed in normal lung tissue. Tumor microarray analysis further demonstrated positive vascular staining for anxA1 in 30 of 80 NSCLC samples, and positive staining of neoplastic cells was observed in 54 of 80 samples. No correlation was observed between vascular and parenchymal anxA1 expression. Two rodent tumor models, B16-F10 and Py230, were determined to have upregulated anxA1 expression in the intratumoral vasculature. These data validate anxA1 as a potential vascular anti-tumor target in a subset of human lung tumors and identify rodent models which demonstrate anxA1 expression in tumor vasculature.

Correlation study between flash dual source CT perfusion imaging and regional lymph node metastasis of non-small cell lung cancer.

BACKGROUND: To explore the correlation of flash dual source computed tomography perfusion imaging (CTPI) and regional lymph node metastasis of non-small cell lung cancer (NSCLC), and to evaluate the value of CT perfusion parameters in predicting regional lymph node metastasis of NSCLC. METHODS: 120 consecutive patients with NSCLC confirmed by postoperative histopathology were underwent flash dual source CT perfusion imaging in pre-operation. The CT perfusion parameters of NSCLC, such as blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability (PMB) were obtained by the image post-processing. Then microvessel density (MVD), luminal vascular number (LVN), luminal vascular area (LVA) and luminal vascular perimeter (LVP) of NSCLC were counted by immunohistochemistry. These cases were divided into group A (patients with lymph node metastasis, 58 cases) and group B (patients without lymph node metastasis, 62 cases) according to their pathological results. The CT perfusion parameters and the microvessel parameters were contrastively analysed between the two groups. Receiver operating characteristic (ROC) curve was used to assess the diagnostic efficiency of CT perfusion parameters in predicting regional lymph node metastasis of NSCLC in pre-operation. RESULTS: Group A presented significantly lower LVA, BF and higher MTT, PMB than Group B (P < 0.05), while BV, LVN, LVP and MVD were no significant difference (P > 0.05). Correlation analysis showed that BF was correlated with LVA and LVP (P < 0.05), while BV, MTT and PMB were not correlated with LVN, LVA and LVP (P > 0.05). All the perfusion parameters were not correlated with MVD. According to the ROC curve analysis, when BF < 85.16 ml/100 ml/min as a cutoff point to predict regional lymph node metastasis of NSCLC, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 60.8, 81.7, 71.5, 75.6 and 69.5% respectively. CONCLUSION: Flash dual source CT perfusion imaging can non-invasively indicate the luminal vascular structure of tumor and BF can be used as one of the important indexes in predicting regional lymph node metastasis of NSCLC in pre-operation.