Lung cancer ranks the first cancer-related morbidity and mortality in China. Tumor metastasis always predicts the poor prognosis for patients. Moreover, lymphatic metastasis is one of the most significant predictors of poor prognosis in patients with non-small cell lung cancer (NSCLC) and lymphangiogenesis represents the bridge that functionally facilitates tumor lymphatic metastasis. In this review, we first discussed the molecular mechanisms of tumor-associated lymphangiogenesis and the interaction between tumor microenvironment and lymphatic endothelial cells, then, summarized the role of non-coding RNA in regulating tumor-associated lymphangiogenesis in recent frontier studies, with the aim to provide some novel insights on NSCLC-related lymphangiogenesis research, diagnosis and treatment.
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Carcinoma, Non-Small-Cell Lung/genetics* ; Disease Progression ; Endothelial Cells ; Humans ; Lung Neoplasms/genetics* ; Lymphangiogenesis ; Lymphatic Metastasis ; Lymphatic Vessels ; Tumor Microenvironment ; Vascular Endothelial Growth Factor C

OBJECTIVE: To investigate the effect of exosomes derived from Epstein-Barr virus (EBV)-positive nasopharyngeal carcinoma (NPC) cells on lymphangiogenesis and lymph node metastasis of NPC. METHODS: Exosomes from NP69 cells and EBV-positive HK1 (HK1-EBV) cells were obtained by ultracentrifugation and identified by Western blotting and nanoparticle tracking analysis. Dio dye phagocytosis test was performed to observe exosome uptake by lymphatic endothelial cells. Lymphatic endothelial cells were treated with exosomes from nasopharyngeal epithelium (NP69), HK1-EBV, and C666-1 cells or exosome-free supernatant of HK1-EBV and C666-1 cells, and tube formation and migration of the cells were observed. In a nude mouse model of popliteal lymph node metastasis of NPC, the effects of normal saline, NP69 cell-derived exosomes, HK1-EBV cell-derived exosomes, exosome-free supernatant of HK1-EBV cells, and HK1-EBV exosome-free supernatant protein on lymphangiogenesis and lymph node metastasis of the tumor were observed. RESULTS: The exosomes obtained by ultracentrifugation contained abundant exosome-specific proteins and showed a normal size range. The exosomes from NPC cells and NP69 cells could be taken up by lymphatic endothelial cells. Compared with the blank control and exosomes form NP69 cells, exosomes derived from HK1-EBV and C666-1 cells significantly promoted tube formation and migration of lymphatic endothelial cells ( CONCLUSIONS Exosomes from EBV-positive NPC cells can significantly promote lymphangiogenesis and lymph node metastasis of NPC.
Animals ; Cell Line, Tumor ; Endothelial Cells ; Epstein-Barr Virus Infections ; Exosomes ; Herpesvirus 4, Human ; Humans ; Lymphangiogenesis ; Lymphatic Metastasis ; Mice ; Mice, Nude ; Nasopharyngeal Carcinoma ; Nasopharyngeal Neoplasms

Vascular endothelial growth factor (VEGF)-C and its receptor, vascular endothelial growth factor receptor (VEGFR)-3, are responsible for lymphangiogenesis in both embryos and adults. In epilepsy, the expression of VEGF-C and VEGFR-3 was significantly upregulated in the human brains affected with temporal lobe epilepsy. Moreover, pharmacologic inhibition of VEGF receptors after acute seizures could suppress the generation of spontaneous recurrent seizures, suggesting a critical role of VEGF-related signaling in epilepsy. Therefore, in the present study, the spatiotemporal expression of VEGF-C and VEGFR-3 against pilocarpine-induced status epilepticus (SE) was investigated in C57BL/6N mice using immunohistochemistry. At 1 day after SE, hippocampal astrocytes and microglia were activated. Pyramidal neuronal death was observed at 4 days after SE. In the subpyramidal zone, VEGF-C expression gradually increased and peaked at 7 days after SE, while VEGFR-3 was significantly upregulated at 4 days after SE and began to decrease at 7 days after SE. Most VEGF-C/VEGFR-3-expressing cells were pyramidal neurons, but VEGF-C was also observed in some astrocytes in sham-manipulated animals. However, at 4 days and 7 days after SE, both VEGFR-3 and VEGF-C immunoreactivities were observed mainly in astrocytes and in some microglia of the stratum radiatum and lacunosum-moleculare of the hippocampus, respectively. These data indicate that VEGF-C and VEGFR-3 can be upregulated in hippocampal astrocytes and microglia after pilocarpine-induced SE, providing basic information about VEGF-C and VEGFR-3 expression patterns following acute seizures.
Adult ; Animals ; Astrocytes ; Brain ; Embryonic Structures ; Epilepsy ; Epilepsy, Temporal Lobe ; Hippocampus ; Humans ; Immunohistochemistry ; Lymphangiogenesis ; Mice ; Microglia ; Pyramidal Cells ; Receptors, Vascular Endothelial Growth Factor ; Seizures ; Status Epilepticus ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factor C ; Vascular Endothelial Growth Factor Receptor-3

PURPOSE: Animal models show a strong relationship between lymphangiogenesis and lymph node metastasis. However, the clinical significance of lymphangiogenesis in patients with colorectal cancer (CRC) remains uncertain. This study aimed to evaluate the association between c-Met and lymphangiogenic factors and to elucidate the prognostic significance of c-Met in patients with CRC. METHODS: A total of 379 tissue samples were obtained from surgically resected specimens from patients with CRC at Soonchunhyang University Cheonan Hospital between January 2002 and December 2010. The expressions of c-Met, vascular endothelial growth factor (VEGF)-C, VEGF-D, VEGF receptor (VEGFR)-3, and podoplanin were examined using immunohistochemistry. The expression of c-Met and clinical factors were analyzed. RESULTS: Of the 379 tissues, 301 (79.4%) had c-Met expression. High expression of c-Met in tumor cells was significantly associated with high expression of VEGF-C (P < 0.001) and VEGFR-3 (P = 0.001). However, no statistically significant association with podoplanin (P = 0.587) or VEGF-D (P = 0.096) was found. Of the 103 evaluable patients, expression of c-Met in tumor cells was significantly associated with advanced clinical stage (P = 0.020), positive lymph node status (P = 0.038), and high expression of VEGF-C (P = 0.020). However, no statistically significant association with podoplanin (P = 0.518), VEGFR-3 (P = 0.085), VEGF-D (P = 0.203), or overall survival (P = 0.360) was found. CONCLUSION: Our results provide indirect evidence for an association and possible regulatory link of c-Met with the lymphangiogenic markers, but c-Met expression in patients with CRC is not a prognostic indicator for overall survival.
Chungcheongnam-do ; Colorectal Neoplasms* ; Humans ; Immunohistochemistry ; Lymph Nodes ; Lymphangiogenesis ; Models, Animal ; Neoplasm Metastasis ; Receptors, Vascular Endothelial Growth Factor ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factor C ; Vascular Endothelial Growth Factor D ; Vascular Endothelial Growth Factor Receptor-3

OBJECTIVE: To analyze the changes in tumor lymphatic vessel density (LVD) in patients with lung adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive adenocarcinoma (IA) and explore the regulatory factors of LVD. METHODS: Complete clinicopathological data were collected form a total of 301 patients with lung adenocarcinoma, including 28 (9.3%) with AIS, 86 (28.6%) with MIA, and 187 (62.1%) with IA. The LVD of all the adenocarcinomas were calculated after D2-40 immunohistochemical staining, and MT1-MMP and VEGF-C expression levels were also evaluated. The differences in LVD among the groups and the correlations of tumor LVD with the expressions of MT1-MMP and VEGF-C and the clinicopathological factors were analyzed. RESULTS: The LVD differed significantly among AIS, MIA, and IA groups (= 0.000). The LVDs was significantly correlated with the level of VEGF-C protein expression (=0.917, =0.009), tumor size (= 0.686, =0.017), lymph node metastasis (=0.739, =0.000), and clinical stage (=0.874, =0.012) of the patients. CONCLUSIONS Tumor lymphangiogenesis plays an important role in lung adenocarcinoma progression, and VEGF-C may promote this process.
Adenocarcinoma ; chemistry ; pathology ; Adenocarcinoma of Lung ; chemistry ; pathology ; Humans ; Immunohistochemistry ; Lymphangiogenesis ; Lymphatic Vessels ; chemistry ; pathology ; Neoplasm Staging ; Prognosis ; Tumor Burden ; Vascular Endothelial Growth Factor C ; analysis

The lymphatic vasculature has been regarded as a passive conduit for interstitial fluid and responsible for the absorption of macromolecules such as proteins or lipids and transport of nutrients from food. However, emerging data show that the lymphatic vasculature system plays an important role in immune modulation. One of its major roles is to coordinate antigen transport and immune-cell trafficking from peripheral tissues to secondary lymphoid organs, lymph nodes. This perspective was recently updated with the notion that the interaction between lymphatic endothelial cells and leukocytes controls the immune-cell migration and immune responses by regulating lymphatic flow and various secreted molecules such as chemokines and cytokines. In this review, we introduce the lymphatic vasculature networks and genetic transgenic models for research on the lymphatic vasculature system. Next, we discuss the contribution of lymphatic endothelial cells to the control of immune-cell trafficking and to maintenance of peripheral tolerance. Finally, the physiological roles and features of the lymphatic vasculature system are further discussed regarding inflammation-induced lymphangiogenesis in a pathological condition, especially in mucosal tissues such as the gastrointestinal tract and respiratory tract.
Absorption ; Chemokines ; Cytokines ; Endothelial Cells ; Endothelium ; Extracellular Fluid ; Gastrointestinal Tract ; Leukocytes ; Lymph Nodes ; Lymphangiogenesis ; Mucous Membrane ; Peripheral Tolerance ; Respiratory System

PURPOSE: To correlate tumor stiffness and lymphangiogenesis in breast cancer and to find its clinical implications. MATERIALS AND METHODS: A total of 140 breast cancer patients were evaluated. Tumor stiffness was quantitatively measured by shear-wave elastography in preoperative ultrasound examination, calculated as mean elasticity value (kPa). Slides of resected breast cancer specimens were reviewed for most fibrotic area associated with tumor. D2-40 immunohistochemical staining was applied for fibrotic areas to detect the lymphatic spaces. Microlymphatic density, tumor stiffness, and clinicopathologic data were analyzed. RESULTS: Higher elasticity value was associated with invasive size of tumor, microlymphatic density, histologic grade 3, absence of extensive intraductal component, presence of axillary lymph node metastasis, and Ki-67 labeling index (LI) in univariate regression analysis, and associated with Ki-67 LI and axillary lymph node metastasis in multivariate regression analysis. Microlymphatic density was associated histologic grade 3, mean elasticity value, and Ki-67 LI in univariate regression analysis. In multivariate regression analysis, microlymphatic density was correlated with mean elasticity value. CONCLUSION: In breast cancer, tumor stiffness correlates with lymphangiogenesis and poor prognostic factors.
Adult ; Aged ; Aged, 80 and over ; Breast/pathology ; Breast Neoplasms/*diagnostic imaging/*pathology ; Elasticity Imaging Techniques/*methods ; Female ; Humans ; Lymph Nodes/pathology ; Lymphangiogenesis/*physiology ; Lymphatic Metastasis/*pathology ; Middle Aged ; Multivariate Analysis ; Neoplasm Invasiveness ; Neoplasm Staging ; Regression Analysis

Lymph node metastasis (LNM) is an important prognostic factor in head and neck cancer (HNC), which leads to recurrence and poor outcome. Despite the advances in multimodality treatment protocols, overall survival in patients with LNM remains limited, thus calling for the need of a more thorough understanding of the biology in metastatic process. In the past, LNM had been suspected to rely mostly on passive mechanistic impulse from primary tumor. However, recent discovery of new lymphatic markers, regulating growth factors, and cognate receptors, has elucidated the active biological regulation during metastatic cascades, which primarily involves primary tumor lymphangiogenesis, pre-metastatic niche formation, and sentinel LNM. In this review, we discuss recent literatures on the mechanisms of LNM in HNC that is expected to allow a better understanding of the disease as well as suggesting a potential clinical implication.
Biology ; Clinical Protocols ; Head and Neck Neoplasms* ; Head* ; Humans ; Intercellular Signaling Peptides and Proteins ; Lymph Nodes* ; Lymphangiogenesis ; Lymphatic Metastasis ; Neoplasm Metastasis* ; Recurrence

Rheumatoid arthritis (RA) and osteoarthritis (OA) are the two most common joint diseases, and they have characterization of synovial inflammation and cartilage destruction, associated with the accumulation of numerous catabolic mediators and inflammatory cells in the synovial space and surrounding soft tissues. How these factors are cleared and if the "clearance" process contributes to pathogenesis of arthritis are not known. Recently, we found the existence of the peri-articular lymphatic system in mouse joints. The blockade of lymphangiogenesis and lymphatic draining function accelerates while stimulation of lymphatic function attenuates the severity of joint tissue lesions in mouse models of RA and OA. More importantly, we noticed the similarity between the dysfunction of lymphatic drainage in arthritic joints and "Bi" theory of Chinese medicine (CM), and demonstrated that several Bi disease-treated herbal drugs directly affect the function of lymphatic endothelial cells. Here we review the advances about the interactions between joint inflammation and changes in the peri-articular lymphatic system and discuss our view of linking "Bi" theory of CM to lymphatic dysfunction in arthritis.
Animals ; Arthritis ; etiology ; therapy ; Disease Models, Animal ; Humans ; Joints ; pathology ; Lymphangiogenesis ; Lymphatic Vessels ; pathology ; Medicine, Chinese Traditional

PURPOSE: To evaluate the effect of subconjunctival bevacizumab injection before conjunctival autograft for pterygium. METHODS: Twenty-five eyes (25 patients) with pterygium received a subconjunctival injection of 2.5 mg (0.1 mL) bevacizumab 1-2 weeks prior to conjunctival autograft surgery. The control group (25 eyes of 25 patients) received the same operation. Two weeks, 1 month and every month after the surgery, the vascularization of surgical site, the recurrence rate and the effect of wound healing were analyzed. RESULTS: The bevacizumab group showed a decreased conjunctival vascularity grade compared with the control group based on light microscopy. The bevacizumab group also showed lower vascular epithelial growth factor (VEGF) compared with the control group using immunohistochemical analysis and western blot. There was no recurrence in both groups, but, persistent autograft edema was observed at 8 weeks postoperatively in the bevacizumab group. CONCLUSIONS: Although preoperative injection of bevacizumab effectively reduced vascularity and VEGF concentration of pterygium tissue, prolonged autograft edema was observed. Based on these results, bevacizumab inhibits lymphangiogenesis as well as angiogenesis. Therefore, delayed wound healing should be considered when subconjunctival bevacizumab injection is administered before pterygium surgery.
Autografts* ; Blotting, Western ; Edema ; Lymphangiogenesis ; Microscopy ; Pterygium* ; Recurrence ; Vascular Endothelial Growth Factor A ; Wound Healing ; Bevacizumab