First international consensus on the methodology of lymphangiogenesis quantification in solid human tumours

Examining the correlation of lymphangiogenesis biomarkers with clinical condition in Age-Related Macular Degeneration (AMD)

The aim of this study is to investigate the relationship between age-related macular degeneration (AMD) and lymphangiogenesis biomarkers, namely LYVE-1, Podoplanin, VEGF-C, VEGFR-2 and VEGFR-3. This prospective and interventional study includes 30 patients with AMD which may be dry or wet type and 30 controls for whom vitrectomy and phacoemulsification was indicated due to additional pathologies (epiretinal membrane, macular hole, retinal detachment, and cataract). 0.1-0,2 ml of aqueous humor and 0.5-1 ml of vitreous sample was taken during the operations. Before the operations 1 tube serum was also taken. All the lymphangiogenesis biomarkers in the study are examined by ELISA method. LYVE-1 (p = 0.001) and Podoplanin (p = 0.004) levels in the vitreous for the patient group are found to be significantly lower than the control group. Serum (p = 0.019), vitreous (p = 0.001), aqueous (p < 0.001) levels of VEGF-C for the patient group are significantly higher than the control group. VEGF-C/VEGFR-2 (p < 0.001), VEGF-C/VEGFR-3 (p < 0.001) ratios in the vitreous for the patient group are found to be significantly higher than the control group. Especially in wet AMD patients, LYVE-1 level is significantly lower in the vitreous (p = 0.002) and aqueous (p = 0.002) than the control group. In addition, Podoplanin level is observed as significantly lower in the vitreous (p = 0.014) and serum (p = 0.002) in comparison to control group. In the wet AMD group, VEGF-C level in the vitreous (p < 0.001), aqueous (p < 0.001) and serum (p = 0.001) is higher than the control group. The result of this study indicates a valid relationship between the weakening of lymphangiogenesis and the pathophysiology of AMD, especially for the wet type. It is observed that the levels of receptors that bind VEGF-C (VEGFR-2 and VEGFR-3) do not increase at the same rate as VEGF-C to compensate for the increase in VEGF-C. The absence of an increase in VEGFR-3, which is especially necessary for lymphangiogenesis, also suggests that lymphangiogenesis is weakened or decreased in AMD. In the future interventional studies with larger series, examination of lymphangiogenic biomarkers in inflammatory retinal diseases and glaucoma may reveal unexplored details.

Lymphatic Endothelial Markers and Tumor Lymphangiogenesis Assessment in Human Breast Cancer

Metastasis via lymphatic vessels or blood vessels is the leading cause of death for breast cancer, and lymphangiogenesis and angiogenesis are critical prerequisites for the tumor invasion–metastasis cascade. The research progress for tumor lymphangiogenesis has tended to lag behind that for angiogenesis due to the lack of specific markers. With the discovery of lymphatic endothelial cell (LEC) markers, growing evidence demonstrates that the LEC plays an active role in lymphatic formation and remodeling, tumor cell growth, invasion and intravasation, tumor–microenvironment remodeling, and antitumor immunity. However, some studies have drawn controversial conclusions due to the variation in the LEC markers and lymphangiogenesis assessments used. In this study, we review recent findings on tumor lymphangiogenesis, the most commonly used LEC markers, and parameters for lymphangiogenesis assessments, such as the lymphatic vessel density and lymphatic vessel invasion in human breast cancer. An in-depth understanding of tumor lymphangiogenesis and LEC markers can help to illustrate the mechanisms and distinct roles of lymphangiogenesis in breast cancer progression, which will help in exploring novel potential predictive biomarkers and therapeutic targets for breast cancer.

Extracellular Hsp90α Promotes Tumor Lymphangiogenesis and Lymph Node Metastasis in Breast Cancer

Early detection and discovery of new therapeutic targets are urgently needed to improve the breast cancer treatment outcome. Here we conducted an official clinical trial with cross-validation to corroborate human plasma Hsp90α as a novel breast cancer biomarker. Importantly, similar results were noticed in detecting early-stage breast cancer patients. Additionally, levels of plasma Hsp90α in breast cancer patients were gradually elevated as their clinical stages of regional lymph nodes advanced. In orthotopic breast cancer mouse models, administrating with recombinant Hsp90α protein increased both the primary tumor lymphatic vessel density and sentinel lymph node metastasis by 2 and 10 times, respectively. What is more, Hsp90α neutralizing antibody treatment approximately reduced 70% of lymphatic vessel density and 90% of sentinel lymph node metastasis. In the in vitro study, we demonstrated the role of extracellular Hsp90α (eHsp90α) as a pro-lymphangiogenic factor, which significantly enhanced migration and tube formation abilities of lymphatic endothelial cells (LECs). Mechanistically, eHsp90α signaled to the AKT pathway through low-density lipoprotein receptor-related protein 1 (LRP1) to upregulate the expression and secretion of CXCL8 in the lymphangiogenic process. Collectively, this study proves that plasma Hsp90α serves as an auxiliary diagnosis biomarker and eHsp90α as a molecular mediator promoting lymphangiogenesis in breast cancer.

Transient Expression of Lymphatic Markers in Retrobulbar Intraconal Orbital Vasculature During Fetal Development

Purpose

The aim of this study is to investigate the presence of orbital lymphatic vessels during fetal and neonatal development and in adults using a panel of lymphatic markers.

Methods

This was a retrospective observational case series. For analyzing lymphatic vessels, we used formalin-fixed paraffin-embedded enucleated eyes from 25 human fetuses between 13 and 24 weeks of gestation and postnatal eyes from 15 children and 5 adults. Immunohistochemical analysis of lymphatic vessels was performed for the markers: lymphatic vessel endothelial hyaluronic acid receptor-1 (LYVE-1), podoplanin (D2-40), Prospero-related homeobox gene-1 (Prox-1), pan-endothelial marker CD31, and blood vessel endothelium specific CD34.

Results

Vasculature showing endothelial expression of LYVE-1, D2-40, Prox-1, and CD31 in combination with absence or weak expression of CD34, as would be expected for lymphatic vessels, was seen in 11 of 25 fetuses in an age range from 14 weeks to 23 weeks of gestation (44%). This lymphatic vascular staining pattern was also observed in 4 of 15 liveborn children (27%), all within 1 month of age, of which two were born prematurely at 32 and 34 weeks of gestation. Interestingly, an incomplete lymphatic staining pattern was observed in another 4 fetuses and two liveborn children of 4 months and 7 years old. No expression of lymphatic markers was observed in adult orbital vasculature.

Conclusions

No retrobulbar intraorbital lymphatic vessels were observed in adults, however, we did observe transient expression of lymphatic markers in retrobulbar intraconal orbital vasculature during fetal and early neonatal development. The orbit may, therefore, be proposed to possess a full range of lymphatic plasticity.

Absence of Intraocular Lymphatic Vessels in Uveal Melanomas with Extrascleral Growth

The aim of this study was to investigate the presence of intraocular lymphatic vessels in patients with uveal melanomas and extrascleral extension using a panel of lymphatic markers. The following immunohistochemical markers were analyzed: lymphatic vessel endothelial hyaluronic acid receptor-1 (LYVE-1), podoplanin (D2-40), prospero-related homeobox gene-1 (Prox-1), pan-endothelial marker cluster of differentiation 31 (CD31), and blood vessel endothelium-specific CD34. Lymphatic vessels were defined as a combination of staining of the following positive markers: LYVE-1, D2-40, Prox-1, and CD31; and no staining of the negative marker CD34. In total, 456 patients were enucleated; 16 of the 46 uveal melanomas with extrascleral extension were contained in stored paraffin tissue. Two samples of the 16 uveal melanomas showed focal positive intraocular vascular staining for LYVE-1 and co-expression of CD31 and CD34. Due to the lack of Prox-1 and D2-40, and positive expression of CD34, these cannot be classified as lymphatic vessels. In one case recruitment of an extraocular, intratumoral lymphatic vascular structure was observed in the periphery of the subconjunctival extrascleral extension. Intraocular lymphatic vessels are absent in uveal melanomas with extrascleral extension; however, we provide proof for recruitment of intratumoral lymphatics by uveal melanomas with extraocular extension from subconjunctival lymphatics that may explain the rare cases of regional lymphatic spread. A panel of antibodies is necessary to detect lymphatic vessels with high specificity.

Lymphatic vessel density is associated with CD8+ T cell infiltration and immunosuppressive factors in human melanoma

Increased density of tumor-associated lymphatic vessels correlates with poor patient survival in melanoma and other cancers, yet lymphatic drainage is essential for initiating an immune response. Here we asked whether and how lymphatic vessel density (LVD) correlates with immune cell infiltration in primary tumors and lymph nodes (LNs) from patients with cutaneous melanoma. Using immunohistochemistry and quantitative image analysis, we found significant positive correlations between LVD and CD8+ T cell infiltration as well as expression of the immunosuppressive molecules inducible nitric oxide synthase (iNOS) and 2,3-dioxygénase (IDO). Interestingly, similar associations were seen in tumor-free LNs adjacent to metastatic ones, indicating loco-regional effects of tumors. Our data suggest that lymphatic vessels play multiple roles at tumor sites and LNs, promoting both T cell infiltration and adaptive immunosuppressive mechanisms. Lymph vessel associated T cell infiltration may increase immunotherapy success rates provided that the treatment overcomes adaptive immune resistance.

Low Lymphatic Vessel Density Correlates with Lymph Node Metastasis in Oral Squamous Cell Carcinoma

STATEMENT OF THE PROBLEM

Regional lymph nodes are the nodes draining lymph from region around the tumor and presence of metastatic tumor in regional lymph nodes is the most important prognostic factor for malignant tumors of epithelial origin. Lymphangiogenesis is associated with an increased incidence of regional lymph nodes metastasis and is possibly an essential step for metastasis. Tumor cells secrete lymphangiogenic cytokines, which results in formation of lymphatic vessels within and around the tumor and act as portals for tumor spread.

PURPOSE

The present study aims to investigate and quantify lymphatic vessel density (LVD) in oral squamous cell carcinoma (OSCC) and determine whether LVD can predict the risk of sentinel lymph node metastasis.

MATERIAL AND METHOD

50 specimens of OSCC, without and with lymph node metastasis (25 each) along with 25 specimens of normal oral mucosa were assessed and LVD was quantified by D2-40 immunostaining. Discrete hotspots of intratumoral lymphatics were identified in superficial and deep areas in all carcinomas to calculate LVD.

RESULTS

When compared to normal mucosa, LVD decreased in the superficial intratumoral areas and decreased further in deep areas. In addition, LVD in the superficial and deep areas of OSCC without nodal metastasis was significantly higher than that in OSCC with nodal metastasis.

CONCLUSION

Our study provides evidence that lymphangiogenesis varies within the tumor. Lymphatic vessels are either compressed, collapsed, destroyed or absent in deep intratumoral region. Decrease in LVD predicts cervical lymph node metastasis both in superficial and deep areas. Lymphatics in superficial areas are probably major conduit for nodal metastasis in OSCCs.

Functional intratumoral lymphatics in patient-derived xenograft models of squamous cell carcinoma of the uterine cervix: implications for lymph node metastasis

Studies of cell line-derived human tumor xenografts have suggested that the lymphatics seen in immunohistochemical preparations from non-peripheral regions of tumors are nonfunctional. In this investigation, lymphangiogenesis, hemangiogenesis, and lymph node metastasis were studied in patient-derived xenograft (PDX) models of carcinoma of the uterine cervix. Lymph vessel density (LVD) and blood vessel density (BVD) were measured in immunohistochemical preparations. The expression of angiogenesis-related genes was investigated by quantitative PCR. Lymphatic functionality was assessed with the ferritin assay, and tumor interstitial fluid pressure (IFP) was measured with a Millar catheter. The PDX models mirrored the angiogenesis and aggressiveness of the donor patients' tumors, and two highly aggressive models developed functional lymphatics within the tumor mass. Tumors with functional intratumoral lymphatics showed low IFP, high LVD, high BVD, high expression of a large number of angiogenesis-related genes, and high incidence of lymph node metastases. LVD correlated with BVD, and lymph node metastasis was associated with high LVD and high BVD. Nine angiogenesis-related genes associated with the development of functional intratumoral lymhatics were identified. High expression of these genes, high LVD, and high BVD may be important biomarkers for poor outcome in cervix carcinoma.

Clinicopathological Significance of Tumor Lymphatic Vessel Density in Head and Neck Squamous Cell Carcinoma

Various studies have demonstrated that the lymphatic system is the additional route for solid tumor metastasis. Lymph nodes metastasis in Head and neck squamous cell carcinoma (HNSCC) is a major prognostic indicator for disease progression and a guide for therapeutic strategies. We conducted a study to compare intratumoral (IT) and peritumoral (PT) lymphatic vessel density (LVD) in HNSCC using lymphatic marker D2-40 and its correlation with lymph node metastasis, histological grading and other clinicopathological parameters. Fifty specimen of HNSCC with modified radical neck dissection tissue were included in the study group. Tissue from tumor, peritumoral tissue, tumor margin and all the lymph nodes were processed for paraffin wax blocks and histopathological diagnosis. Immunohistochemical profile of lymphatic vessels in intratumoral and peritumoral tissue was assessed by subjecting one section each from the tumor and peritumoral tissue to D2-40 immunostain. To determine LVD, four fields with the highest LVD (hot spots) were identified. The mean values were calculated by taking an average of all the measurements. The comparison of LVD between peritumoral and intratumoral area revealed significantly higher PT-LVD (P = 0.001). No significant association was seen between LVD, IT-LVD and PT-LVD and different age groups, gender, site of tumor, risk factors, size of tumor, tumor inflammation, pushing/infiltrating margin and stage of tumors. Significantly higher LVD, IT-LVD and PT-LVD was seen in association with lymph node metastasis. Both high intratumoral and peritumoral LVD were found significantly associated with the presence of lymph node metastasis, however lymphatic vessels were found to be significantly more numerous and larger in peritumoral areas as compared to intratumoral lymphatics. The specificity of D2-40 as a lymphatic endothelial marker was also confirmed. The results of our study support the possibility of using the determination of tumor lymphangiogenesis to identify patients of HNSCC who are at risk of developing the lymph node metastasis.

CCL5 promotes VEGF-C production and induces lymphangiogenesis by suppressing miR-507 in human chondrosarcoma cells

Chondrosarcoma is the second most frequently occurring type of bone malignancy that is characterized by the distant metastasis propensity. Vascular endothelial growth factor-C (VEGF-C) is the major lymphangiogenic factor, and makes crucial contributions to tumor lymphangiogenesis and lymphatic metastasis. Chemokine CCL5 has been reported to facilitate angiogenesis and metastasis in chondrosarcoma. However, the effect of chemokine CCL5 on VEGF-C regulation and lymphangiogenesis in chondrosarcoma has largely remained a mystery. In this study, we showed a clinical correlation between CCL5 and VEGF-C as well as tumor stage in human chondrosarcoma tissues. We further demonstrated that CCL5 promoted VEGF-C expression and secretion in human chondrosarcoma cells. The conditioned medium (CM) from CCL5-overexpressed cells significantly induced tube formation of human lymphatic endothelial cells (LECs). Mechanistic investigations showed that CCL5 activated VEGF-C-dependent lymphangiogenesis by down-regulating miR-507. Moreover, inhibiting CCL5 dramatically reduced VEGF-C and lymphangiogenesis in the chondrosarcoma xenograft animal model. Collectively, we document for the first time that CCL5 induces tumor lymphangiogenesis by the induction of VEGF-C in human cancer cells. Our present study reveals miR-507/VEGF-C signaling as a novel mechanism in CCL5-mediated tumor lymphangiogenesis. Targeting both CCL5 and VEGF-C pathways might serve as the potential therapeutic strategy to block cancer progression and metastasis in chondrosarcoma.

SPARC suppresses lymph node metastasis by regulating the expression of VEGFs in ovarian carcinoma

Lymph node metastasis is one of the most valuable determinants for the prognosis of ovarian cancer. However, the molecular mechanisms underlying lymphangiogenesis in ovarian cancer is still poorly understood. Secreted protein acidic and rich in cysteine (SPARC), a Ca2+-binding matricellular glycoprotein that modulates cell adhesion, migration and differentiation, is thought to play a decisive role in tumor metastasis. Vascular endothelial growth factor (VEGF)-C and VEGF-D contributes to tumor-associated lymphatic vessel growth, enhancing the metastatic spread of tumor cells to lymph nodes. The aim of the present study was to investigate the relationship among SPARC, VEGFs and lymph node metastasis in ovarian cancer. We found that SKOV3 cells expressed high-level SPARC, much more than SKOV3-PM4 cells (a subline with high directional lymphatic metastatic potentials established from the metastatic lymph node generated by human ovarian carcinoma cell line SKOV3 in nude mice) did at both mRNA and protein levels. A SPARC-overexpressed SKOV3-PM4 cell line was constructed and it was found that upregulation of SPARC expression suppressed the growth, migration and invasion of SKOV3-PM4 cells as well as markedly reduced the expression of VEGF-D at both mRNA and protein level by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot assay. In 47 of ovarian malignant tissues, the expression of SPARC, VEGF-C and VEGF-D were determined by immunohistochemistry. Lymphatic microvessel density (LVD) and microvessel density (MVD) were evaluated by immunostaining with CD34 and D2-40 antibodies, respectively. We found that SPARC expression was significantly lower in tissues with lymph node metastasis as compared to tissues without lymph node metastasis. SPARC expression was inversely associated with the degree of malignancy and it had a negative correlation with VEGF-C expression, VEGF-D expression, LVD and MVD which were actually higher for advanced tumors than for non-advanced tumors. These results suggest SPARC might function as a tumor suppressor inhibiting angiogenesis and lymphangiogenesis in ovarian cancer by reducing the expression of VEGF-C and VEGF-D.

Late Solitary Extraocular Recurrence From Previously Resected Iris Melanoma

PURPOSE

To report on cases of late extraocular relapse of previously resected iris melanoma, without concurrent intraocular recurrence.

DESIGN

Retrospective case series.

METHODS

A retrospective chart review of 4 patients diagnosed with late subconjunctival relapse of previously resected iris melanoma.

RESULTS

Three female patients and 1 male patient underwent iris tumor resection and presented to our service with suspicious conjunctival lesions at a median of 22 years later (mean: 21 years). None showed intraocular relapse. Treatment of the conjunctival tumors included excisional biopsy (n = 4), followed by cryotherapy (n = 3) and/or brachytherapy (n = 3). In all cases, histopathology confirmed malignant melanoma, with no intraepithelial component or associated melanosis. Genetic sequencing (n = 3) showed wild-type BRAF and NRAS in all. GNA11 mutation was found in 1 case. On array-based comparative genomic hybridization (n = 3), gain of 6p was found in 2 cases and gain of 8 in 2. Overall, findings were strongly suggestive of a diagnosis of late extraocular relapse from previously resected iris melanoma. In a median of 2.5 years (mean: 7.7 years) from the subconjunctival relapse, no further episodes of intraocular/extraocular recurrence were recorded, and all patients were free from distant metastasis.

CONCLUSIONS

Patients undergoing iris melanoma resection are at risk of developing late solitary extraocular relapse even more than 30 years after surgery. In the absence of an intraocular component, diagnosis may be challenging, as tumors mimic a primary conjunctival lesion. Management by excisional biopsy followed by adjuvant therapy was successful, and histopathology and genetic analysis supported a diagnosis of extraocular uveal tumor spread rather than a primary conjunctival tumor.

Tumor thickness and histological features as predictors of invasive foci within preoperatively diagnosed ductal carcinoma in situ

Small invasion into ductal carcinoma in situ (DCIS) can easily be overlooked in resected breast specimens. To disclose useful markers predictive of invasive foci within preoperatively diagnosed DCIS lesions, a retrospective histopathological comparison was made between postoperatively diagnosed invasive ductal carcinoma with a predominant intraductal component (IDCPIC) (n=43) and pure DCIS (n=82). Through a multivariate logistic regression analysis model, 5 variables (DCIS grade, "tumor thickness," extent of retraction cleft, presence of lymph node metastasis, and HER2 score) were found to be significantly associated with the presence of invasive foci within DCIS; with a cutoff point of 0.315, sensitivity, specificity, positive predictive value, and negative predictive value were 0.93, 0.77, 0.68, and 0.95, respectively. No statistically significant difference was observed in recurrence-free survival between IDCPIC and pure DCIS, whereas the IDCPIC curve showed a slightly earlier decline than the DCIS one. In general, preoperative detection of lymph node metastasis in DCIS patients is elusive because of the extremely tiny metastatic size in most cases; thus, a 4-variable model, without lymph node metastasis, would be the actual working model. Furthermore, tumor "thickness" was found to be the most significant parameter predictive of invasive foci within DCIS. Although IDCPIC and pure DCIS showed similar recurrence-free survival curves, prediction of invasive foci within DCIS necessitates postoperative pathological analysis of surgically resected lesions.

Inhibition of lymphangiogenesis in vitro and in vivo by the multikinase inhibitor nintedanib

Purpose

To investigate the feasibility of nintedanib, a novel triple angiokinase inhibitor, for inhibiting lymphatic endothelial cell (LEC)-induced lymphangiogenesis in vitro and inflammatory corneal lymphangiogenesis in vivo.

Materials and methods

Methylthiazolyldiphenyl-tetrazolium bromide (MTT) test, transwell system, and tube-formation assay were used to evaluate the effects of nintedanib on the proliferation, migration, and tube formation of LECs stimulated by vascular endothelial growth factor-C (VEGF-C), basic fibroblast growth factor (bFGF), or platelet-derived growth factor-BB (PDGF-BB). The murine model of suture-induced corneal neovascularization was used to assess the anti-hemangiogenic and anti-lymphangiogenic effects of nintedanib via systemic and topical applications. Corneal flatmounts were stained with lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) and CD31, and the areas of involved blood and lymph vessels were analyzed morphometrically. Corneal cryosections were stained with F4/80 to evaluate inflammatory cell recruitment.

Results

We observed a significant enhanced effect of LEC proliferation, migration, and tube formation with the administration of VEGF-C, PDGF-BB, and bFGF, respectively, which was diminished by nintedanib. Both topical and systemic applications of nintedanib inhibited suture-induced hemangiogenesis and lymphangiogenesis in the murine cornea. A reduction in F4/80⁺ cell infiltration was observed at day 14 after corneal suture for both systemic and topical applications of nintedanib. In comparison with controls, 61% of F4/80⁺ cell recruitment was inhibited via the systemic application of nintedanib, while 49% of F4/80⁺ cell recruitment was inhibited with the topical application of nintedanib.

Conclusion

Nintedanib was shown to inhibit in vitro lymphangiogenesis stimulated by VEGF-C, bFGF, and PDGF-BB. Applied topically or systemically, it effectively inhibited corneal hemangiogenesis and lymphangiogenesis, accompanied by reduced inflammatory cell recruitment, which represents a new promising treatment for graft rejection after penetrating keratoplasty.

Relationship of mast cell density with lymphangiogenesis and prognostic parameters in breast carcinoma

In many cancers, mast cell density (MCD) in the tumor microenvironment is associated with tumor progression and, to a greater extent, angiogenesis. Our study was designed to investigate the correlation between MCD, tumor lymphangiogenesis, and several well-established prognostic parameters in breast cancer. One hundred and four cases of invasive breast carcinoma diagnosed in our clinic between 2007 and 2011 were included. Mast cells and lymphatic vessels were stained with toluidine blue and D2-40, respectively, and their densities were calculated in various areas of tumors and lymph nodes. The variables of MCD and lymphatic vessel density (LVD) were compared using prognostic parameters as well as with each other. As tumor size and volume increased, MCD increased comparably in metastatic lymph nodes; intratumoral and peritumoral LVD also increased. Lymphovascular invasion, lymphatic invasion, perineural invasion, and estrogen receptor positivity were positively related to intratumoral MCD. The relationship between peritumoral MCD and nontumoral breast tissue MCD was statistically significant. Stage was correlated with MCD in metastatic lymph nodes. Metastatic lymph node MCD and intratumoral MCD were also significantly related. Stage, lymphatic invasion, perineural invasion, lymphovascular invasion, and metastatic lymph node MCD were all correlated with intratumoral and/or peritumoral LVD. As nuclear grade increased, intratumoral LVD became higher. In breast carcinoma, MCD, depending on its location, was related to several prognostic parameters. Notably, mast cells may have at least some effect on lymphangiogenesis, which appears to be a predictor of tumor progression.

Lymphangiogenesis: fuel, smoke, or extinguisher of inflammation's fire?

Lymphangiogenesis is a recognized hallmark of inflammatory processes in tissues and organs as diverse as the skin, heart, bowel, and airways. In clinical and animal models wherein the signaling processes of lymphangiogenesis are manipulated, most studies demonstrate that an expanded lymphatic vasculature is necessary for the resolution of inflammation. The fundamental roles that lymphatics play in fluid clearance and immune cell trafficking from the periphery make these results seemingly obvious as a mechanism of alleviating locally inflamed environments: the lymphatics are simply providing a drain. Depending on the tissue site, lymphangiogenic mechanism, or induction timeframe, however, evidence shows that inflammation-associated lymphangiogenesis (IAL) may worsen the pathology. Recent studies have identified lymphatic endothelial cells themselves to be local regulators of immune cell activity and its consequential phenotypes - a more active role in inflammation regulation than previously thought. Indeed, results focusing on the immunocentric roles of peripheral lymphatic function have revealed that the basic drainage task of lymphatic vessels is a complex balance of locally processed and transported antigens as well as interstitial cytokine and immune cell signaling: an interplay that likely defines the function of IAL. This review will summarize the latest findings on how IAL impacts a series of disease states in various tissues in both preclinical models and clinical studies. This discussion will serve to highlight some emerging areas of lymphatic research in an attempt to answer the question relevant to an array of scientists and clinicians of whether IAL helps to fuel or extinguish inflammation. Impact statement Inflammatory progression is present in acute and chronic tissue pathologies throughout the body. Lymphatic vessels play physiological roles relevant to all medical fields as important regulators of fluid balance, immune cell trafficking, and immune identity. Lymphangiogenesis is often concurrent with inflammation and can potentially aide or worsen disease progression. How new lymphatic vessels impact inflammation and by which mechanism is an important consideration in current and future clinical therapies targeting inflammation and/or vasculogenesis. This review identifies, across a range of tissue-specific pathologies, the current understanding of inflammation-associated lymphangiogenesis in the progression or resolution of inflammation.

Axillary Skip Metastases and the False-Negative Rate of Sentinel Lymph Node Biopsy in Patients With Breast Cancer Are Related to Negative ALDH-1 Expression and Ki-67 Expression

Breast cancer stem cells (CSCs) have been hypothesized to be the driving force behind tumorigenesis and metastasis. In this study, we evaluated the relationships between CSC expressions in primary breast cancers and corresponding metastatic sentinel and nonsentinel lymph nodes (SLNs and NSLNs). The clinical implications of these relationships were also investigated. CSC expressions were evaluated in 167 breast cancer specimens and associated lymph node biopsies (when present). We used double immunohistochemistry of CD44/CD24 and single immunohistochemistry of ALDH-1 on paraffin-embedded breast tissue, SLN, and NSLN specimens. Seven cases had metastatic NSLNs without SLN involvement—so-called “skip metastasis.” Fifty cases of SLNs (29.9%) and 33 cases of NSLNs (25.7%) had metastases. In the breast cancers, metastatic SLNs, and NSLNs, the expression rates of CD44+/CD24− were 47.9%, 26.1%, and 34.6 %, respectively, while the expression rates of ALDH-1+ were 42.5%, 36.4%, and 33.3%, respectively. Significant relationships were not observed between CSC expressions in breast cancer and metastatic SLNs or NSLNs. The presence of skip metastasis correlated with negative ALDH-1 in breast cancer ( P = .04), as well as several clinicopathologic factors: age >50 years ( P = .004), negative lymphovascular tumor emboli ( P = .02), and high Ki-67 expression ( P = .04). Axillary lymph node metastasis showed no significant relationship with any CSC marker. However, CD44+/CD24− and ALDH-1 expressions of metastatic SLNs correlated with CSCs of primary breast cancers. In summary, skip metastasis correlated with negative expression of ALDH-1 in primary breast cancers, which could be promising as a means of assessing the risk of skip metastasis.

Increased Angiogenesis and Lymphangiogenesis in Metastatic Sentinel Lymph Nodes Is Associated With Nonsentinel Lymph Node Involvement and Distant Metastasis in Patients With Melanoma

Lymph node angio- and lymphangio-genesis have been shown to play an important role in the premetastatic niche of sentinel lymph nodes. In the current study we have investigated the association of angio- and lympangio-genesis related parameters in metastatic sentinel lymph nodes of patients with melanoma with the presence of nonsentinel and distant organ metastasis. Peritumoral and intratumoral relative blood and lymphatic vessel areas (evaluated by Chalkley method), blood and lymphatic microvessel densities, and the rates of blood and lymphatic vessel proliferation were assessed in primary tumors and sentinel lymph node metastasis of 44 patients with melanoma using CD34/Ki-67 and D240/Ki-67 immunohistochemical double staining. Primary melanoma exhibited significantly higher rate of lymphatic proliferation compared with its lymph node metastasis (P < 0.05), while lymph node metastasis showed significantly higher rate of blood vessel proliferation (P < 0.05). Using multivariate logistic regression model, the rate of peritumoral lymphatic proliferation was inversely associated with positive nonsentinel lymph node status (P < 0.05), whereas the rate of intratumoral blood vessel proliferation was associated with distant organ metastasis (P < 0.05). Using multivariate Cox regression analysis, the rate of intratumoral blood vessel proliferation was also inversely associated with overall survival of patients with melanoma (P < 0.05).

Intratumoral and peritumoral lymphatic vessel density both correlate with lymph node metastasis in breast cancer

The status of lymph node involvement is an important prognostic factor for breast cancer. However, the presence of intratumoral lymphatic vessels in primary tumor lesions and the relationship between lymphatic vessel density (LVD) and lymph node metastasis (LNM) have not been firmly established. Therefore, we performed a meta-analysis study to investigate these issues. According to the pre-established inclusion and exclusion criteria, 13 studies, involving 1029 breast cancer patients, were included in this study. Using immunohistochemical staining, intratumoral lymphatic vessels were detected in 40.07% of breast cancer patients (240/599), and peritumoral lymphatics were detected in 77.09% (397/515). All studies demonstrated that peritumoral LVD was higher than intratumoral LVD, with a pooled standard mean difference and 95% confidence interval (95% CI) of 1.75 (1.28 to 2.21). Both intratumoral LVD and peritumoral LVD positively correlated with LNM, with correlation coefficients of 0.14 (95% CI 0.05 to 0.23) and 0.31 (95% CI 0.13 to 0.49), respectively. In summary, our study reports the overall detection rate of intratumoral lymphatics and demonstrates the associations between intratumoral LVD, peritumoral LVD, and LNM in breast cancer. Additionally, controlled studies with a larger number of subjects are needed to establish these relationships.

Ameloblastoma vs basal cell carcinoma: an immunohistochemical comparison

Despite behavioral mimicry of ameloblastoma (AB) and basal cell carcinoma (BCC), they are classified at 2 extremes within pertinent WHO classifications with respect to benign and malignant designation. This study aims to appraise the current allocation of AB in the classification through an immunohistochemical comparison of some aspects of behavior with BCC. Sections from retrospectively retrieved formalin-fixed, paraffin-embedded tissue blocks of AB (n = 37) and BCC (n = 34) were comparatively examined for the immunohistochemical expression for Ki-67, Bcl-2, MMP-2, MMP-9, CD31, and D2-40 monoclonal antibodies. No statistically significant differences between the tumors were found regarding the immunoexpressions of Bcl-2 (P = .252), CD31 microvessel density (P = .895), lymphatic vessel density (P = .642), and MMP-9 stromal expression (P = .083). MMP-2 expression was significantly higher in epithelial and stromal regions of AB (P = .009 and P = .001, respectively), whereas Ki-67 and MMP-9 epithelial expressions were significantly higher in BCC (P < .000 and P = .026, respectively). Within the studied immunohistochemical attributes for tumor behavior, the study accentuated the overall behavioral mimicry of the tumors and indicated that BCCs surmount ABs by the proliferative rate only.

The role of lymphangiogenesis and angiogenesis in tumor metastasis

BACKGROUND

Metastasis is the main cause of mortality in cancer patients. Two major routes of cancer cell spread are currently being recognized: dissemination via blood vessels (hematogenous spread) and dissemination via the lymphatic system (lymphogenous spread). Here, our current knowledge on the role of both blood and lymphatic vessels in cancer cell metastasis is summarized. In addition, I will discuss why cancer cells select one or both of the two routes to disseminate and I will provide a short description of the passive and active models of intravasation. Finally, lymphatic vessel density (LVD), blood vessel density (BVD), interstitial fluid pressure (IFP) and tumor hypoxia, as well as regional lymph node metastasis and the recently discovered primo vascular system (PVS) will be highlighted as important factors influencing tumor cell motility and spread and, ultimately, clinical outcome.

CONCLUSIONS

Lymphangiogenesis and angiogenesis are important phenomena involved in the spread of cancer cells and they are associated with a poor prognosis. It is anticipated that new discoveries and advancing knowledge on these phenomena will allow an improvement in the treatment of cancer patients.

[Markers of angiogenesis in tumor growth]

Angiogenesis is a process of new blood vessels formation. The role of angiogenesis in growth, invasion and metastasis of malignant tumours is nowdays universally recognized. Though, investigation of mechanisms of blood vessels formation and elaboration methods for assessment of tumour angiogenesis are still up-dated. Another important concern are different aspects of usage of immunohistochemical markers of blood vessels endothelium (CD31 and CD34) for assessment of tumour aggressiveness and prognosis. The problems of malignant lymphangiogenesis are also up-to-date. The focus is on methods of immunohistochemical visualization of forming lymphatic vessels, role of podoplanin, the most reliable marker of lymphatic vessels, in their identification, and formulization of the main criteria for lymphangiogenesis estimation, its correlation with metastatic activity and prognostic potential. Studying of angiogenesis and lymph angiogenesis in malignant tumors is important and challenging direction for researching tumour progression and invention of antiangiogenic therapy.

[Immunohistochemical study of the role of mast cells and macrophages in the process of angiogenesis in the atherosclerotic plaques in patients with metabolic syndrome]

OBJECTIVE

to analyze the histotopographic distribution of neogenic vessels, the degree of mast cell degranulation, the expression of markers of macrophages in different types of plaques in different stages and in different arterial vessels in patients with atherosclerosis and in those with metabolic syndrome associated with atherosclerosis and to establish the role of mast cells and macrophages in the development of stages of atherosclerosis along with their diagnostic and prognostic value.

MATERIAL AND METHODS

Fragments of the thoracic and abdominal aorta, middle cerebral, carotid, renal, and iliac, and vertebral arteries from 34 persons who had died from atherosclerosis (n=17) and atherosclerotic complications due to metabolic syndrome (n=17) were examined. The investigators employed standard techniques, such as hematoxylin-eosin or orcein staining; silver impregnation. They used immunohistochemical staining with anti-mast cell tryptase (anti-MCT) for the determination of mast cells, the specific markers CD68 for macrophages, and CD105 (endoglin) for neogenic vessels.

RESULTS

The immunohistochemical technique is effective in identifying mast cells, macrophages, and neogenic vessels in atherosclerotic plaques. They were found in many types of atherosclerotic plaques, advantium, and subendothelial layers in the immediate vicinity of the plaques. There was a statistical correlation between the types of plaques and clinical data, which is of importance in elucidating the specific features of the pathogenesis of atherosclerosis in patients with metabolic syndrome.

CONCLUSION

CD105 is a sensitive marker for neogenic endothelial cells, an effective indicator of microvascular activation and proliferation in the atherosclerotic plaques. Neovascularization in the plaques frequently begins in the intima, progresses, and gives rise to their further destabilization. Anti-MCT staining used to reveal mast cells and CD68 for macrophages can elucidate the important patterns of development of atherosclerosis and its complications in patients with metabolic disturbances.

FGFs: crucial factors that regulate tumour initiation and progression

Fibroblast growth factors (FGFs) are crucial signalling molecules involved in normal cell growth, differentiation and proliferation. Over the past few decades, a large body of research has illustrated effects of individual FGFs on tumour initiation and progression. Tumour development is commonly accompanied with generation of new blood and lymph vessels, which support enhanced cell proliferation. Moreover, acquisition of tumour cells of the epithelial-mesenchymal transition (EMT) phenotype, enhances tumour cell migration and invasion potentials, crucial steps in tumour metastasis. This review summarizes recent findings concerning roles of FGFs in angiogenesis, lymphangiogenesis and EMT.

Leptin promotes VEGF-C production and induces lymphangiogenesis by suppressing miR-27b in human chondrosarcoma cells

Chondrosarcoma is the second most frequently occurring type of bone malignancy that is characterized by the distant metastasis propensity. Vascular endothelial growth factor-C (VEGF-C) is the chief lymphangiogenic mediator, and makes crucial contributions to tumor lymphangiogenesis. Leptin is an adipocytokine and has been indicated to facilitate tumorigenesis, angiogenesis and metastasis. However, the effect of leptin on VEGF-C regulation and lymphangiogenesis in human chondrosarcoma has hugely remained a mystery. Our results showed a clinical correlation between leptin and VEGF-C as well as tumor stage in human chondrosarcoma tissues. We further demonstrated that leptin promoted VEGF-C production and secretion in human chondrosarcoma cells. The conditioned medium from leptin-treated chondrosarcoma cells induced lymphangiogenesis of human lymphatic endothelial cells. We also found that leptin-induced VEGF-C is mediated by the FAK, PI3K and Akt signaling pathway. Furthermore, the expression of microRNA-27b was negatively regulated by leptin via the FAK, PI3K and Akt cascade. Our study is the first to describe the mechanism of leptin-promoted lymphangiogenesis by upregulating VEGF-C expression in chondrosarcomas. Thus, leptin could serve as a therapeutic target in chondrosarcoma metastasis and lymphangiogenesis.

Adiponectin promotes VEGF-C-dependent lymphangiogenesis by inhibiting miR-27b through a CaMKII/AMPK/p38 signaling pathway in human chondrosarcoma cells

Chondrosarcoma is the second most frequently occurring type of bone malignancy characterized by distant metastatic propensity. Vascular endothelial growth factor-C (VEGF-C) is the major lymphangiogenic factor, and makes crucial contributions to tumour lymphangiogenesis and lymphatic metastasis. Adiponectin is a protein hormone secreted predominantly by differentiated adipocytes. In recent years, adiponectin has also been indicated as facilitating tumorigenesis, angiogenesis and metastasis. However, the effect of adiponectin on VEGF-C regulation and lymphangiogenesis in chondrosarcoma has remained largely a mystery. In the present study, we have shown a clinical correlation between adiponectin and VEGF-C, as well as tumour stage, in human chondrosarcoma tissues. We further demonstrated that adiponectin promoted VEGF-C expression and secretion in human chondrosarcoma cells. The conditioned medium from adiponectin-treated cells significantly induced tube formation and migration of human lymphatic endothelial cells. In addition, adiponectin knock down inhibited lymphangiogenesis in vitro and in vivo We also found that adiponectin-induced VEGF-C is mediated by the calmodulin-dependent protein kinase II (CaMKII), AMP-activated protein kinase (AMPK) and p38 signaling pathway. Furthermore, the expression of miR-27b was negatively regulated by adiponectin via the CaMKII, AMPK and p38 cascade. The present study is the first to describe the mechanism of adiponectin-promoted lymphangiogenesis by up-regulating VEGF-C expression in chondrosarcomas. Thus, adiponectin could serve as a therapeutic target in chondrosarcoma metastasis and lymphangiogenesis.

Lymphangiogenesis in Breast Cancer Correlates with Matrix Stiffness on Shear-Wave Elastography

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.

Heterogeneity of tumor cells in the bone microenvironment: Mechanisms and therapeutic targets for bone metastasis of prostate or breast cancer

Bone is the most common target organ of metastasis of prostate and breast cancers. This produces considerable morbidity due to skeletal-related events, SREs, including bone pain, hypercalcemia, pathologic fracture, and compression of the spinal cord. The mechanism of bone metastasis is complex and involves cooperative reciprocal interaction among tumor cells, osteoblasts, osteoclasts, and the mineralized bone matrix. The interaction between the metastatic tumor and bone stromal cells has been commonly referred to as the "vicious cycle". Tumor cells stimulate osteoblasts, which in turn stimulate osteoclasts through the secretion of cytokines such as the TNF family member receptor activator of nuclear κB ligand (RANKL). Activated osteoclasts degrade the bone matrix by producing strong acid and proteinases. Bone degradation by osteoclasts releases TGFβ and other growth factors stored in the bone matrix, that further stimulate tumor cells. Bone modifying agents, targeting osteoclast activity, such as bisphosphonate and RANKL antibodies are considered as the standard of care for reducing SREs of patients with bone metastatic diseases. These agents decrease osteoclast activity and delay worsening of skeletal pain and aggravation of bone metastatic diseases. While the management of SREs by these agents may improve patients' lives, this treatment does not address the specific issues of the patients with bone metastasis such as tumor dormancy, drug resistance, or improvement of survival. Here, we review the mechanisms of bone metastasis formation, tumor heterogeneity in the bone microenvironment, and conventional therapy for bone metastatic diseases and discuss the potential development of new therapies targeting tumor heterogeneity in the bone microenvironment.

Expression of Lymphatic Markers in the Adult Rat Spinal Cord

Under physiological conditions, lymphatic vessels are thought to be absent from the central nervous system (CNS), although they are widely distributed within the rest of the body. Recent work in the eye, i.e., another organ regarded as alymphatic, revealed numerous cells expressing lymphatic markers. As the latter can be involved in the response to pathological conditions, we addressed the presence of cells expressing lymphatic markers within the spinal cord by immunohistochemistry. Spinal cord of young adult Fisher rats was scrutinized for the co-expression of the lymphatic markers PROX1 and LYVE-1 with the cell type markers Iba1, CD68, PGP9.5, OLIG2. Rat skin served as positive control for the lymphatic markers. PROX1-immunoreactivity was detected in many nuclei throughout the spinal cord white and gray matter. These nuclei showed no association with LYVE-1. Expression of LYVE-1 could only be detected in cells at the spinal cord surface and in cells closely associated with blood vessels. These cells were found to co-express Iba1, a macrophage and microglia marker. Further, double labeling experiments using CD68, another marker found in microglia and macrophages, also displayed co-localization in the Iba1+ cells located at the spinal cord surface and those apposed to blood vessels. On the other hand, PROX1-expressing cells found in the parenchyma were lacking Iba1 or PGP9.5, but a significant fraction of those cells showed co-expression of the oligodendrocyte lineage marker OLIG2. Intriguingly, following spinal cord injury, LYVE-1-expressing cells assembled and reorganized into putative pre-vessel structures. As expected, the rat skin used as positive controls revealed classical lymphatic vessels, displaying PROX1+ nuclei surrounded by LYVE-1-immunoreactivity. Classical lymphatics were not detected in adult rat spinal cord. Nevertheless, numerous cells expressing either LYVE-1 or PROX1 were identified. Based on their localization and overlapping expression with Iba1, the LYVE-1+ cell population likely represents a macrophage subpopulation, while a significant fraction of PROX1+ cells belong to the oligodendrocytic lineage based on their distribution and the expression of OLIG2. The response of these LYVE-1+ and PROX1+ cell subpopulations to pathological conditions, especially in spinal cord inflammatory conditions, needs to be further elucidated.

Lymphatic and blood vasculature in primary cutaneous melanomas of the scalp and neck

BACKGROUND

Scalp/neck melanomas have a poor prognosis, possibly because of a rich vascular supply that prompts tumor cells' dissemination.

METHODS

We compared the accuracy of immunohistochemical (IHC) staining with morphology for the identification of lymphovascular invasion in 156 scalp/neck melanomas. We then analyzed the association of vessel invasion and density with pathological features and survival.

RESULTS

IHC-detected lymphatic vessel invasion (LVI) and blood vessel invasion (BVI) were identified in 34.6% and 13.5% of cases, respectively. IHC increased the LVI/BVI detection compared to morphology (40.4% vs 16.6%; p < .001). The degree of peritumoral and intratumoral blood vessel density (BVD) was greater than lymphatic vessel density (LVD). Ulceration was the only factor independently associated with intratumoral (p = .029) and peritumoral (p = .047) BVD. Tumor thickness was the only independent predictor of survival (p = .002).

CONCLUSION

IHC allows accurate assessment of lymphovascular invasion in scalp/neck melanomas. In these tumors, we observed a high incidence of BVI, which deserves further investigations.

Peritumoral D2-40 Chalkley score independently predicts metastases and survival in patients with cutaneous malignant melanoma

BACKGROUND

Many observational studies investigated the prognostic significance of angiogenesis and lymphangiogenesis in patients with melanoma. However, the obtained results are rather contradictory, probably due to the lack of the consensus methodology.

METHODS

To investigate the prognostic significance of angiogenesis and lymphangiogenesis-related parameters in patients with melanoma, we performed a retrospective investigation following the consensus recommendations for angiogenesis and lymphangiogenesis quantification in solid tumors and reporting recommendations for tumor marker (REMARK) criteria for reporting the results. Blood and lymphatic vessel Chalkley scores, endothelial cell proliferation fractions and microvessel densities were quantified using a double immunostaining for endothelial marker CD34 or lymphendothelial marker D240 and the proliferation marker Ki-67 in 196 patients with melanoma. These parameters were evaluated separately for peritumoral (PT) and intratumoral areas and were correlated with outcome.

RESULTS

In multivariate analysis PT D240 Chalkley score was identified as a strongest predictor for sentinel lymph node metastases, non-sentinel lymph node metastases, distant metastases, disease free survival and overall survival in patients with melanoma.

CONCLUSIONS

If additional studies corroborate our findings, we believe that the inclusion of PT D240 Chalkley counts to the routine pathology examination of melanoma samples would provide additional information for identifying high-risk patients.

Significantly high lymphatic vessel density in cutaneous metastasizing melanoma

BACKGROUND

Cutaneous melanoma has the propensity to early metastatic spread via the lymphatic vessels. Recent studies have found a positive correlation between an increased number of tumor-associated lymphatics and lymph node metastasis. The aim of this study was to determine whether there was a difference in the lymphatic vessel density (LVD) when cutaneous metastasizing melanomas were compared with nonmetastasizing melanomas and nevi.

METHODS

Ninety-five melanoma specimens (45 with lymph node metastasis, 50 nonmetastasizing) and 22 nevi specimens (7 compound, 5 intradermal, 4 blue, and 6 dysplastic) were investigated by immunostaining for the lymphatic endothelial marker D2-40. The quantification of lymphatics was conducted by computer-assisted morphometric analysis. Metastasizing and nonmetastasizing melanoma specimens were matched according to their thickness into three classes ≤2.0 mm, 2.01 - 4.0 mm, >4.0 mm.

RESULTS

Metastasizing melanomas thick 2.01-4.0 mm and thicker than 4.0 mm, showed a significantly higher intratumoral and peritumoral LVD compared with nonmetastasizing melanomas (2.01-4.0 mm, p =0.006 and p =0.032, respectively; >4.0 mm, p =0.045 and p =0.026, respectively). No significant difference in intratumoral and peritumoral LVD was found between metastasizing and nonmetastasizing melanomas of thickness ≤2.0 mm. Metastasizing melanomas showed a significantly higher intratumoral LVD compared with compound, intradermal, blue and dysplastic nevi p <0.001, p =0.002, p =0.002 and p <0.001, respectively), and significantly higher peritumoral LVD compared with compound nevi (p=0.039). Total average LVD was significantly higher in metastasizing melanomas than in nonmetastasizing melanomas (p <0.001), compound, intradermal, blue and dysplastic nevi (p <0.001, p <0.001, p =0.001 and p <0.001, respectively).

CONCLUSIONS

This study shows higher LVD in metastasizing melanomas compared with nonmetastasizing melanomas and nevi. In melanomas with intermediate thickness and in thick melanomas, higher intratumoral and peritumoral LVD are significantly associated with lymph node metastasis. This finding suggests that LVD can be a useful marker for identifying melanomas which are at a higher risk for the metastasis development. Hippokratia 2015; 19 (3): 210-215.

Effects of levonorgestrel-releasing intrauterine system on lymphangiogenesis of adenomyosis

OBJECTIVES

Lymphangiogenesis may be involved in the pathogenesis of adenomyosis. We investigated the lymphatic vessels of patients with adenomyosis, including those treated with levonorgestrel-releasing intrauterine system (LNG-IUS).

METHODS

Full-thickness uterine samples were obtained from patients who received hysterectomies. Twenty-one patients with adenomyosis and 17 patients with adenomyosis who were treated with LNG-IUS were included. Eighteen patients with cervical intraepithelial neoplasia served as controls. Immunohistochemical staining was performed with antibodies against podoplanin and lymphatic vessel endothelial hyaluronan receptor 1. The lymphovascular density (LVD) was analyzed in each sample by the "hot spot" method.

RESULTS

The LVDs were significantly higher in the endometrial and myometrial tissues of patients with adenomyosis compared with those of patients treated with the LNG-IUS or controls. No significant differences were noted between the LNG-IUS-treated group and controls. Evaluation of the LVDs according to the menstrual cycle showed that the differences in the endometrial tissues of the adenomyosis group and those of the LNG-IUS-treated group or the controls were more prominent during the secretory phase.

CONCLUSIONS

Treatment with the LNG-IUS resulted in reduced lymphangiogenesis and LVD in the endometrial and myometrial tissues of patients with adenomyosis. Reduced lymphangiogenesis may be one mechanism by which the LNG-IUS reduces adenomyosis-related symptoms.

Blood microvessel density, lymphatic microvessel density and lymphatic invasion in predicting melanoma metastases: systematic review and meta-analysis

In malignant melanoma (MM) there is an urgent need to identify new markers with predictive value superior to the traditional clinical and histological parameters. Angiogenesis and lymphangiogenesis have been recognized as critical processes in tumour growth and metastasis development, and numerous studies have evaluated the significance of these parameters in predicting the prognosis in solid tumours, including MM. We set out to determine whether angiogenesis, lymphangiogenesis and lymphatic invasion (LI) are valuable prognostic markers in MM. We systematically reviewed the available literature and subsequently performed a meta-analysis on the compiled data. To be eligible for the systematic review, a study had to provide the microvessel density (MVD), the lymphatic vessel density (LVD) or information about LI, assessed by immunohistochemistry on the primary site in patients with MM. To be evaluable for the meta-analysis, a study also had to provide information on clinical outcome. We approached selected studies with the Reporting recommendations for tumour marker (REMARK) criteria, verifying whether they had followed the recommendations. In total, nine angiogenesis, seven lymphangiogenesis and 10 LI studies were included in our meta-analysis, representing 419, 474 and 802 patients, respectively. Using meta-analysis, we showed that peritumoral LVD and the presence of LI have prognostic value for patients with MM. In contrast, MVD and intratumoral LVD did not have prognostic value in these patients. LVD and LI seem to have prognostic value for patients with MM.

Cancer stem cells, lymphangiogenesis, and lymphatic metastasis

Although current opinion indicates that tumor-induced lymphangiogenesis plays a key role in promoting the initial spread of malignant tumors, the mechanism that underlies lymphatic spread is not clear. The recent discovery of cancer stem cells (CSCs) in human tumors has challenged our current understanding of tumor recurrence, drug resistance, and metastasis, and opens up new research directions on how cancer cells are capable of switching from dormancy to malignancy. CSCs can be directly and indirectly involved in tumor-induced lymphangiogenesis and ultimately promote lymphatic metastasis. However, the details and the possible relationship between CSCs, lymphangiogenesis, and lymphatic metastasis remain ambiguous, and the origin of tumor lymphatic endothelial cells is controversial. Elucidation of these factors may provide useful information for future research and cancer treatment. In this article, we summarize current knowledge of CSCs, tumor-induced lymphangiogenesis, and lymphatic metastasis and attempt to find an association between key molecular and cellular mechanisms. We provide an overview of CSCs and lymphatic vasculature as potential therapeutic targets. CSC- and lymphatic vasculature-targeted therapy may bring new hope for cancer treatment.

Consensus statement on the immunohistochemical detection of ocular lymphatic vessels

There is currently considerable controversy about existence and classification of "lymphatic vessels" in the eye. Some of the confusion is certainly caused by inappropriate use (or nonuse) of the correct immunohistochemical markers. Many experts in the field expressed the need for a consensus statement, and, in this perspective, authors offer arguments and solutions to reliably continue with immunohistochemical ocular lymphatic research.

Comparison between invasive breast cancer with extensive peritumoral vascular invasion and inflammatory breast carcinoma: a clinicopathologic study of 161 cases

OBJECTIVES

Extensive peritumoral neoplastic lymphovascular invasion (ePVI) is a marker of aggressiveness in invasive breast carcinoma (BC).

METHODS

We explored the impact of ePVI on different BC subtypes. In a total of 2,116 BCs, 91 ePVI-BCs, 70 inflammatory breast carcinomas (IBCs), and 114 casual BCs as a control group (CG-BC) were recruited.

RESULTS

Patients affected by ePVI-BC were younger, had larger tumors, higher histologic grade, elevated Ki-67 score, Her2/neu overexpressed, and more lymph node metastases compared with CG-BC (P < .001). Interestingly, only younger mean age at diagnosis differentiated patients with ePVI-BC from patients affected by IBC. ePVI-BC showed a clinical outcome intermediate between the prognoses of IBC and CG-BC.

CONCLUSIONS

Results suggest that ePVI-BC and IBC may share some pathologic processes, providing a novel perspective on the heterogeneity of BC. Epidemiologic data and molecular studies on gene expression features are needed to rationally classify these tumors into their identified subtypes.

Lymphangiogenesis: implications for diagnosis, treatment, and prognosis in patients with melanoma

Disease course in melanoma often cannot be accurately predicted by means of the prognostic factors usually considered in patients with melanoma; therefore, new factors are clearly needed. Increasingly robust scientific evidence shows that tumor lymph vessels play a key role in melanoma that metastasizes by lymphatic and hematogenous pathways. We review current knowledge and examine the implications of lymphangiogenesis in the diagnosis, treatment, and prognosis of patients with melanoma.

Improved computer-assisted analysis of the global lymphatic network in human cervical tissues

Lymphatic dissemination is a key event in cervical cancer progression and related tumor lymphatic markers are viewed as promising prognostic factor of nodal extension. However, validating such parameters requires an objective characterization of the lymphatic vasculature. Here, we performed a global analysis of the lymphatic network using a new computerized method applied on whole uterine cervical digital images. Sixty-eight cases of cervical neoplasia (12 CIN3, 10 FIGO stage 1A and 46 stage IB1) and 10 cases of normal cervical tissue were reacted with antibodies raised against D2-40, D2-40/p16 and D2-40/Ki67. Immunostained structures were automatically detected on whole slides. The lymphatic vessel density (D2-40), proliferating lymphatic vessel density (D2-40/ki67) and spatial lymphatic distribution in respect to the adjacent epithelium were assessed from normal cervix to early cervical cancer and correlated with lymphovascular space invasion and lymph node status. Prominent lymphatic vessel density and proliferating lymphatic vessel density are detected under the transformation zone of benign cervix and no further increase is noted during cancer progression. Notably, a shift of lymphatic vessel distribution toward the neoplastic edges is detected. In IB1 cervical cancer, although intra- and peritumoral lymphatic vessel density are neither correlated with lymphovascular space invasion nor with lymph node metastasis, a specific spatial distribution with more lymphatic vessels in the vicinity of tumor edges is predictive of lymphatic dissemination. Herein, we provide a new computerized method suitable for an innovative detailed analysis of the lymphatic network. We show that the transformation zone of the benign cervix acts as a baseline lymphangiogenic niche before the initiation of neoplastic process. During cancer progression, this specific microenvironment is maintained with lymphatic vessels even in closer vicinity to tumor cells.

Expression and clinical significance of matrix metalloproteinase-9 in lymphatic invasiveness and metastasis of breast cancer

BACKGROUND

Matrix metalloproteinase 9 (MMP-9) is a type-IV collagenase that is highly expressed in breast cancer, but its exact role in tumor progression and metastasis is unclear.

METHODS

MMP-9 mRNA and protein expression was examined by real-time reverse transcriptase PCR and immunohistochemical staining, respectively, in 41 breast cancer specimens with matched peritumoral benign breast epithelial tissue and suspicious metastatic axillary lymph nodes. Lymph vessels were labeled with D2-40 and lymphatic microvessel density (LMVD) was calculated. Correlation of MMP-9 protein expression with clinicopathological parameters and LMVD was also evaluated.

RESULTS

MMP-9(+) staining in breast cancer specimens (35/41, 85.4%) was higher than in matched epithelium (21/41, 51.2%; P<0.05) and lymph nodes (13/41, 31.7%; P<0.001). Higher MMP-9 mRNA expression was also detected in tumor specimens compared with matched epithelial tissues and lymph nodes (P<0.05). Elevated MMP-9 expression was correlated with lymph node metastasis and LMVD (P<0.05).

CONCLUSION

MMP-9 was overexpressed in breast cancer specimens compared with peritumoral benign breast epithelium and lymph nodes. Moreover, its expression in the matched epithelium and lymph nodes was positively associated with lymph node metastasis, and its expression in lymph nodes was positively associated with lymphangiogenesis in breast cancer. Thus, MMP-9 is a potential marker for breast cancer progression.

Extracellular matrix protein 1 is correlated to carcinogenesis and lymphatic metastasis of human gastric cancer

Background

Tumor-induced lymphangiogenesis is a crucial step in malignant invasion and metastasis. Extracellular matrix protein 1 (ECM1) was recently reported to play a role in lymphangiogenesis. In the present work, we aimed to evaluate the role of ECM1 in gastric cancer and examined whether aberrant expression of ECM1 increased the tumorigenic and metastatic potential of human gastric cancer.

Methods

The mRNA and protein expression of ECM1 in gastric cancer specimen and the noncancerous counterparts from 77 patients were detected by real-time PCR and immunohistochemistry staining. Lymphatic microvessel density (LMVD) in the corresponding serial sections was assessed by counting the lymphatic microvessels labelled by D2-40. The correlations between ECM1 expression, LMVD, and the clinicopathological parameters were examined.

Results

ECM1 protein expression was detected in 70.1% (54/77) of gastric cancer specimen, significantly higher than that in the corresponding counterparts (P <0.01). ECM1 mRNA in tumor specimen was also dramatically amplified. Elevated LMVD and ECM1 were positively correlated (P <0.01). In addition, ECM1 protein expression was also closely associated with depth of tumor invasion and TNM stage (P <0.05, respectively).

Conclusions

ECM1 expression is aberrant elevated in tumor specimen and is closely related to the tumorigenic and metastatic potential of human gastric cancer. Thus, carrying out the protein examination may be beneficial to predict carcinogenesis and metastatic spread of human gastric cancer.