Tumor lymphangiogenesis correlates with lymph node metastasis and clinicopathologic parameters in oral squamous cell carcinoma

Intratumoral platelet microthrombi in oral squamous cell carcinoma: A marker of lymph node metastasis

OBJECTIVE

A hypercoagulable state exists in patients with oral squamous cell carcinoma (OSCC), but the role of platelets in the tumour microenvironment has not been explored. This study revealed the status of intratumoral plateletmicrothrombi (PLT-MT) and their clinicopathological relevance and predictive value in OSCC.

STUDY DESIGN

This study retrospectively evaluated 106 OSCC patients. Tumour and tumour-adjacent tissue specimens were used to stain PLT-MT. Clinicopathological information, patient follow-ups and outcomes and preoperative coagulation and inflammatory hematologic indicators were collected, and their correlation with PLT-MT was analysed.

RESULTS

Intratumoral PLT-MT was present in 35 of 106 patients with OSCC who had higher preoperative D-dimer, CRP, FIB and PT levels and lower TT levels. PLT-MT was an independent correlative factor of lymph node metastasis and suggested worse OS in N0 patients.

CONCLUSIONS

Intratumoral PLT-MT was found in OSCC and was correlated with a hypercoagulable inflammatory state. PLT-MT was an independent marker of lymph node metastasis and showed potential in prognosis prediction.

Microvascular density analysis and histological parameters of oral cancer progression

OBJECTIVES

This study aimed to investigate the role of blood and lymphatic microvascular density in the progression of oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

The sample was composed of 54 cases of OSCC. The immunoexpression to anti-alpha-smooth muscle actin (α-SMA) and to anti-endoglin (CD105) was used to determine the microvessel density (MVD); anti-podoplanin (D2-40) was used to assess the lymphatic vessel density (LVD); vascular endothelial growth factor (VEGF) was evaluated in malignant cells. The histological differentiation, the worst pattern of invasion (WPOI), tumour thickness and tumour budding (TB) intensity were assessed using haematoxylin-eosin and anti-pan-cytokeratin (AE1/AE3). Patients' age and sex, TNM classification and follow-up time were collected from the medical records.

RESULTS

MVD markers presented a similar pattern of expression in blood vessels. However, only α-SMA + MVD was significantly higher among women and in tumours ≤4 cm. LVD was lower in tumours with lymph node metastasis. Regarding the histological parameters, high TB intensity was associated with histological differentiation, advanced clinical stage, greater tumour thickness and reduced disease-free survival. No difference was found in VEGF.

CONCLUSIONS

The decrease in OSCC LVD could be related to pathological node involvement, whereas high TB intensity could indicate OSCC progression and worse patient outcomes.

Identification of a novel lymphangiogenesis signature associated with immune cell infiltration in colorectal cancer based on bioinformatics analysis

BACKGROUND

Lymphangiogenesis plays an important role in tumor progression and is significantly associated with tumor immune infiltration. However, the role and mechanisms of lymphangiogenesis in colorectal cancer (CRC) are still unknown. Thus, the objective is to identify the lymphangiogenesis-related genes associated with immune infiltration and investigation of their prognosis value.

METHODS

mRNA expression profiles and corresponding clinical information of CRC samples were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. The lymphangiogenesis-related genes (LymRGs) were collected from the Molecular Signatures database (MSigDB). Lymphangiogenesis score (LymScore) and immune cell infiltrating levels were quantified using ssGSEA. LymScore) and immune cell infiltrating levels-related hub genes were identified using weighted gene co-expression network analysis (WGCNA). Univariate Cox and LASSO regression analyses were performed to identify the prognostic gene signature and construct a risk model. Furthermore, a predictive nomogram was constructed based on the independent risk factor generated from a multivariate Cox model.

RESULTS

A total of 1076 LymScore and immune cell infiltrating levels-related hub genes from three key modules were identified by WGCNA. Lymscore is positively associated with natural killer cells as well as regulator T cells infiltrating. These modular genes were enriched in extracellular matrix and structure, collagen fibril organization, cell-substrate adhesion, etc. NUMBL, TSPAN11, PHF21A, PDGFRA, ZNF385A, and RIMKLB were eventually identified as the prognostic gene signature in CRC. And patients were divided into high-risk and low-risk groups based on the median risk score, the patients in the high-risk group indicated poor survival and were predisposed to metastasis and advanced stages. NUMBL and PHF21A were upregulated but PDGFRA was downregulated in tumor samples compared with normal samples in the Human Protein Atlas (HPA) database.

CONCLUSION

Our finding highlights the critical role of lymphangiogenesis in CRC progression and metastasis and provides a novel gene signature for CRC and novel therapeutic strategies for anti-lymphangiogenic therapies in CRC.

Dysregulation of Lymphatic Endothelial VEGFR3 Signaling in Disease

Vascular endothelial growth factor (VEGF) receptor 3 (VEGFR3), a receptor tyrosine kinase encoded by the FLT4 gene, plays a significant role in the morphogenesis and maintenance of lymphatic vessels. Under both normal and pathologic conditions, VEGF-C and VEGF-D bind VEGFR3 on the surface of lymphatic endothelial cells (LECs) and induce lymphatic proliferation, migration, and survival by activating intracellular PI3K-Akt and MAPK-ERK signaling pathways. Impaired lymphatic function and VEGFR3 signaling has been linked with a myriad of commonly encountered clinical conditions. This review provides a brief overview of intracellular VEGFR3 signaling in LECs and explores examples of dysregulated VEGFR3 signaling in various disease states, including (1) lymphedema, (2) tumor growth and metastasis, (3) obesity and metabolic syndrome, (4) organ transplant rejection, and (5) autoimmune disorders. A more complete understanding of the molecular mechanisms underlying the lymphatic pathology of each disease will allow for the development of novel strategies to treat these chronic and often debilitating illnesses.

Lymph node ratio as a survival predictor for head and neck squamous cell carcinoma with multiple adverse pathological features

BACKGROUND

The study investigates the prognostic significance of lymph node ratio (LNR) on patients with head and neck squamous cell carcinoma (HNSCC) with coexistence of multiple adverse pathological features.

METHODS

In total, 100 patients with coexistence of perineural invasion, lymphovascular invasion, and extranodal extension of first primary HNSCC treated with radical surgery followed by adjuvant chemoradiotherapy were enrolled.

RESULTS

The optimal LNR cut-off value for predicting overall survival (OS) and cancer specific survival (CSS) was 7%. In Cox model, we observed that LNR ≥7% was a statistically significant unfavorable predictor of OS (HR: 2.689; 95% CI: 1.228-5.889; p = 0.013) and CSS (HR: 3.162; 95% CI: 1.234-8.102; p = 0.016).

CONCLUSION

For HNSCC patients with coexistence of multiple adverse pathological features, LNR is an independent survival predictor. Novel intensified treatments are needed for the subgroup of patients with a high LNR.

Modeling lymphangiogenesis: Pairing in vitro and in vivo metrics

Lymphangiogenesis is the mechanism by which the lymphatic system develops and expands new vessels facilitating fluid drainage and immune cell trafficking. Models to study lymphangiogenesis are necessary for a better understanding of the underlying mechanisms and to identify or test new therapeutic agents that target lymphangiogenesis. Across the lymphatic literature, multiple models have been developed to study lymphangiogenesis in vitro and in vivo. In vitro, lymphangiogenesis can be modeled with varying complexity, from monolayers to hydrogels to explants, with common metrics for characterizing proliferation, migration, and sprouting of lymphatic endothelial cells (LECs) and vessels. In comparison, in vivo models of lymphangiogenesis often use genetically modified zebrafish and mice, with in situ mouse models in the ear, cornea, hind leg, and tail. In vivo metrics, such as activation of LECs, number of new lymphatic vessels, and sprouting, mirror those most used in vitro, with the addition of lymphatic vessel hyperplasia and drainage. The impacts of lymphangiogenesis vary by context of tissue and pathology. Therapeutic targeting of lymphangiogenesis can have paradoxical effects depending on the pathology including lymphedema, cancer, organ transplant, and inflammation. In this review, we describe and compare lymphangiogenic outcomes and metrics between in vitro and in vivo studies, specifically reviewing only those publications in which both testing formats are used. We find that in vitro studies correlate well with in vivo in wound healing and development, but not in the reproductive tract or the complex tumor microenvironment. Considerations for improving in vitro models are to increase complexity with perfusable microfluidic devices, co-cultures with tissue-specific support cells, the inclusion of fluid flow, and pairing in vitro models of differing complexities. We believe that these changes would strengthen the correlation between in vitro and in vivo outcomes, giving more insight into lymphangiogenesis in healthy and pathological states.

Endoglin in head and neck neoplasms

Tumors of the head and neck region form a heterogeneous group of pathologies, including various benign lesions and malignant neoplasms. Endoglin, also known as CD105, is an accessory receptor for transforming growth factor beta (TGF-β), that regulates angiogenesis, both under physiological and pathological conditions. It is highly expressed in proliferating endothelial cells. Therefore, it is considered as a marker of tumor-related angiogenesis. In this review we discuss the role of endoglin as a possible marker of carcinogenesis, as well as a potential target for antibody-based therapies in the neoplasms of the head and neck region.

Everolimus downregulates STAT3/HIF-1α/VEGF pathway to inhibit angiogenesis and lymphangiogenesis in TP53 mutant head and neck squamous cell carcinoma (HNSCC)

TP53 mutant head and neck squamous cell carcinoma (HNSCC) patients exhibit poor clinical outcomes with 50-60% recurrence rates in advanced stage patients. In a recent phase II clinical trial, adjuvant therapy with everolimus (mTOR inhibitor) significantly increased 2-year progression-free survival in p53 mutated patients. TP53-driven mTOR activation in solid malignancies causes upregulation of HIF-1α and its target, downstream effector VEGF, by activating STAT3 cell signaling pathway. Here, we investigated the effects of everolimus on the STAT3/HIF-1α/VEGF pathway in TP53 mutant cell lines and xenograft models. Treatment with everolimus significantly inhibited cell growth in vitro and effectively reduced the growth of TP53 mutant xenografts in a minimal residual disease (MRD) model in nude mice. Everolimus treatment was associated with significant downregulation of STAT3/HIF-1α/VEGF pathway in both models. Further, treatment with everolimus was associated with attenuation in tumor angiogenesis and lymphangiogenesis as indicated by decreased microvessel density of vascular and lymphatic vessels in HN31 and FaDu xenografts. Everolimus downregulated the STAT3/HIF-1α/VEGF pathway to inhibit growth and in vitro tube formation of HMEC-1 (endothelial) and HMEC-1A (lymphatic endothelial) cell lines. Our studies demonstrated that everolimus inhibits the growth of TP53 mutant tumors by inhibiting angiogenesis and lymphangiogenesis through the downregulation of STAT3/HIF-1α/VEGF signaling.

Understanding the squamous cell carcinoma immune microenvironment

Primary cutaneous squamous cell carcinoma (cSCC) is the second most common human cancer with a rising incidence of about 1.8 million in the United States annually. Primary cSCC is usually curable by surgery; however, in some cases, cSCC eventuates in nodal metastasis and death from disease specific death. cSCC results in up to 15,000 deaths each year in the United States. Until recently, non-surgical options for treatment of locally advanced or metastatic cSCC were largely ineffective. With the advent of checkpoint inhibitor immunotherapy, including cemiplimab and pembrolizumab, response rates climbed to 50%, representing a vast improvement over chemotherapeutic agents used previously. Herein, we discuss the phenotype and function of SCC associated Langerhans cells, dendritic cells, macrophages, myeloid derived suppressor cells and T cells as well as SCC-associated lymphatics and blood vessels. Possible role(s) of SCC-associated cytokines in progression and invasion are reviewed. We also discuss the SCC immune microenvironment in the context of currently available and pipeline therapeutics.

Lymphatic Vascular Density, the Expression of Podoplanin and Tumor Budding in Oral Squamous Cell Carcinoma

BACKGROUND

Notwithstanding recent advances in oral squamous cell carcinoma (OSCC) management, its mortality rate is still high. It is imperative to investigate new parameters that are complementary to clinical staging for OSCC to provide better prognostic insight. The presence of isolated neoplastic cells or small clusters of up to four cells at the tumor's invasive front, called tumor budding, is a morphological marker of OSCC with prognostic value. Increased lymphatic vascular density (LVD) and a high expression of podoplanin in neoplastic cells have also been associated with worse prognosis in OSCC. To investigate these markers in OSCC, we evaluated differences in LVD and the expression of podoplanin in neoplastic cells between tumors with high-intensity tumor budding versus low-intensity or no tumor budding. In the samples of high-intensity budding, differences in those parameters between the​​ budding area and the area outside the budding were also evaluated. Furthermore, the study assessed differences in LVD and in the expression of podoplanin in neoplastic cells concerning OSCC clinicopathological characteristics.

METHODS

To those ends, we subjected 150 samples of OSCC to immunohistochemistry to evaluate the intensity of tumor budding (via multi-cytokeratin immunostaining). Moreover, the 150 samples of OSCC and 15 specimens of normal oral mucosa (used as a control) were employed to assess LVD and the expression of podoplanin (in neoplastic cells of OSCC and in the lining epithelium of normal oral mucosa), both via podoplanin immunostaining. Data were processed into descriptive and analytical statistics.

RESULTS

No differences were observed neither in the LVD nor in the expression of podoplanin in neoplastic cells concerning sex, age, tobacco smoking, tumor location and tumor size. The LVD was greater in OSCC and in tumors with high-intensity budding than in normal mucosa but did not differ between normal mucosa and tumors with low-intensity or no tumor budding. The data analyses also revealed that LVD was greater in tumors with high-intensity tumor budding than in tumors with low-intensity or no budding and showed no difference in LVD between the budding area and the area outside the budding. When compared to the lining epithelium of the normal mucosa, the expression of podoplanin was greater in neoplastic cells of OSCC, tumors with high-intensity budding and tumors with low-intensity or no tumor budding. The expression of podoplanin in neoplastic cells was also greater in tumors with high-intensity budding and, within those tumors, greater in the budding area than in the area outside de budding.

CONCLUSION

Those findings support the hypothesis that tumor budding is a biological phenomenon associated with the progression and biological behavior of OSCC.

The Regulation of Lymph Node Pre-Metastatic Niche Formation in Head and Neck Squamous Cell Carcinoma

In many distinct forms of malignancies, there is a close relationship between lymph node (LN) metastases and further dissemination to distant organs, and this is a critical prognostic factor. At the beginning of the process, the original tumor secretes soluble substances or releases extracellular vesicles (EVs) that are carried through lymphatic channels to draining (sentinel) LN. The tumor-derived factors then drive LN remodeling. These significant alterations occur prior to the emergence of the first metastatic cell, bringing about the development of a pre-metastatic niche that allows metastatic cells to survive and thrive. In this review, we discuss current information available about the regulation of lymph node pre-metastatic niche in head and neck squamous cell carcinoma (HNSCC), and the role of EVs in forming the pre-metastatic niche.

Upregulation of Synuclein-γ and Snai1 Contributes to Poor Clinical Prognosis in Oral Squamous Cell Carcinoma Patients

Synuclein-γ (SNCG) and Snai1 play an important role in the occurrence and development of different types of malignant tumors. However, the association between SNCG and Snai1 and the effect of their combination on oral squamous cell carcinoma (OSCC) are unknown. The purpose of this study was to assess the expression of SNCG and Snai1 in OSCC tissues and their role in the genesis, development, diagnosis, and prognosis of OSCC. In this study, we first analyzed the Gene Expression Omnibus (GEO) database to determine the expression of SNCG and Snai1 in OSCC. And we also evaluated the correlation between the expression of SNCG and Snai1 and clinical pathological parameters in OSCC from The Cancer Genome Atlas (TCGA) database. Then, the expression of SNCG and Snai1 in OSCC and its adjacent tissues in our experimental cohort were detected by qRT-PCR, Western blot, and immunohistochemistry, and the relationship between their expression and clinical pathological parameters were analyzed. At the same time, the correlation between the expression of SNCG and Snai1 was analyzed from the TCGA, GEO database, and our experimental cohort. Next, the ROC curves were constructed to explore the diagnostic value of SNCG and Snai1 in OSCC. Finally, the survival curves were drawn, and the univariate and multivariate Cox regression analyses were performed to determine the prognostic value of SNCG and Snai1 in OSCC. The study found that SNCG and Snai1 were highly expressed in OSCC tissues. The expression of SNCG was related to the differentiation of OSCC, while that of Snai1 was related to the T stage, lymph node metastasis, clinical stage, and differentiation. Besides, the expression of SNCG in OSCC was positively correlated with that of Snai1. In addition, we also found that SNCG and Snai1 could well distinguish OSCC patients from normal people; especially, the combined diagnosis of SNCG and Snai1 had a better effect, with a specificity up to 96.67%. Moreover, SNCG-negative/Snai1-negative OSCC patients had the best prognosis. Multivariate analysis displayed that SNCG-positive expression was an independent risk factor for prognosis in OSCC patients. The results of this study strongly suggested that SNCG and Snai1 might have a cooperative effect in the occurrence and development of OSCC. They may become new markers for the diagnosis and prognosis of OSCC.

Immunohistochemical and immunofluorescence expression profile of lymphatic endothelial cell markers in oral cancer

Lymphangiogenesis makes an important contribution to the tumour microenvironment (TME), but little is known about this in oral squamous cell carcinoma (OSCC). Archival formalin-fixed paraffin-embedded specimens (28 OSCC, 10 inflamed and 6 normal oral mucosa controls) were processed using immunohistochemistry (IHC) with antibodies against lymphatic markers D2-40 (podoplanin), LYVE-1, VEGFR3 and Prox1. After the endothelial cells had been highlighted by the various markers for lymphatic endothelium, the positive stained cells and vessels were identified and counted in a systematic manner to determine microvessel density. Double-labelling immunofluorescence (DLIF) was used to investigate the specificity of D2-40 and LYVE-1 to lymphatic endothelial cells (LECs) as opposed to blood ECs. There was higher D2-40 and Prox1 lymphatic vessel density (P = .001) in the OSCC group when compared with both control groups. Some malignant keratinocytes expressed lymphatic markers, as did a much smaller number of epithelial cells in the control groups. DLIF showed that no vessels co-expressed D2-40/CD34 or LYVE/CD34. Some D2/40⁺ LVs were LYVE^- . D2-40 was the most specific LEC marker in OSCC tissues. These results establish that the OSCC TME contains significantly more lymphatic vessels expressing D2-40 and Prox1 than the control groups, which may play a role in facilitating lymphatic invasion and metastases.

Intratumoral lymphatic vascular density is an independent factor for disease-free and overall survival in advanced stage oral squamous cell carcinoma

OBJECTIVE

The presence of lymphatic and blood vessels in oral squamous cell carcinoma (OSCC) should play a key role in progression and dissemination. This study aimed to evaluate the correlation between the lymphatic and blood vessel densities with prognostic outcomes in advanced stage OSCC.

STUDY DESIGN

Immunohistochemical reactions for D-240, CD34, and CD105 were performed in 88 advanced stage OSCC cases located at the oral tongue and the floor of the mouth. The lymphatic vascular density (LVD), blood vascular density (BVD), and neoformed vascular density (NVD) were assessed by counting positive reactions in 4 hotspot areas, both intratumoral (IT) and peritumoral (PT), at high magnification (× 40).

RESULTS

High IT LVD was associated with extracapsular spread of lymph node metastasis (P = .03). Recurrence rates were correlated with IT LVD (P < .0001), IT BVD (P = .036), and IT NVD (P = .047), and overall survival was associated with high IT LVD (P = .0016) and IT NVD (P = .009). Yet, IT LVD was an independent factor for disease-free survival and for overall survival based on the Cox proportional hazards model.

CONCLUSIONS

Our results suggest that high IT LVD has a strong impact on survival outcomes in advanced stage OSCC.

Study of expression of endoglin (CD105) in oral squamous cell carcinoma

Context:

Oral cancer is the 8^th most common cancer in the world. An important feature of carcinogenesis is angiogenesis. Endoglin is a powerful marker of neovascularization in solid malignancies. This study was done to ascertain its role as an indicator of metastasis and prognosis.

Aim:

This study aimed to evaluate and compare the expression of endoglin (CD105) in metastatic primary tumor, lymph node of the metastasized tumor, nonmetastatic primary tumor and in normal buccal mucosa immunohistochemically.

Settings and Design:

The total sample size comprised 45 formalin-fixed paraffin-embedded tissue blocks, n = 10 metastasized primary tumor, n = 10 lymph nodes of metastasized primary tumor, n = 20 nonmetastasized oral squamous cell carcinoma and n = 5 normal buccal mucosa were studied.

Subjects and Methods:

Immunohistochemistry for endoglin was performed and microvessel density (MVD) was determined by hot spot method. Microvessel density was compared between the groups.

Statistical Analysis:

Statistical analysis was used using one-way ANOVA. P < 0.05 was statistically significant.

Results:

Endoglin expression in metastatic cases (0.68 + 0.10) was higher than nonmetastatic cases (0.45 + 0.20) and the difference was statistically significant (P = 0.002).

Conclusion:

This study shows that presence of endoglin determines the metastatic potential of the tumor and its prognosis, thus, could be considered as a potential target of therapy.

Development and Validation of a Nomogram based on cell growth-related Biomarkers for Oral Squamous Cell Carcinoma

Purpose: We aimed to develop a prognostic nomogram based on immunohistochemistry (IHC) biomarkers of patients with oral squamous cell carcinoma (OSCC). Methods: A total of 294 patients were enrolled in the study. The least absolute shrinkage and selection operator (LASSO) Cox regression model was performed to develop a combined IHC score (IHCs) classifier. Results: Five biomarkers, specifically c-Met, Vimentin, HIF-2α, VEGF-c, and Bcl-2 were extracted. Then, an IHCs classifier was developed, and patients were stratified into high- and low-IHCs groups. In the training cohort, the 5-year overall survival (OS) was 62.1% in low-IHCs group and 28.2% in high-IHCs group (P<0.001). The 5-year OS was 68.6% for the low-IHCs group and 28.4% for the high-IHCs group in the validation cohort (P<0.001). The area under the ROC curve (AUROC) of the combination of the IHCs classifier and TNM stage was 0.746 (95% CI: 0.658-0.833) in the training cohort and 0.735 (95% CI: 0.651-0.818) in the validation cohort, respectively. Conclusions: The nomogram could effectively predict the prognosis for patients with OSCC and may be employed as a potential tool to guide the individual decision-making process.

Expression of podoplanin in tumor cells and lymphatic vessels in both tumoral and peritumoral areas and correlation with metastatic potential of oral squamous cell carcinoma

Aim:

This study aims to study the expression of podoplanin in tumor cells as well as the lymphatic vessels (LVs) in both tumoral and peritumoral areas and correlate the importance of the lymphatic microvascular density (LMVD) in oral squamous cell carcinoma (OSCC) and its metastatic potential.

Materials and Methods:

D2–40 expression and LV density (LVD) were assessed using antibody D240, in 45 diagnosed cases of all the three grades of OSCC. D2–40 expression was evaluated in both epithelial cells as well as the LVs.

Results:

D2–40 expression in OSCC showed two different patterns - diffuse and focal. LMVD was calculated and difference in peritumoral and intra tumoral LVs was also assessed. A marked increase was seen we progressed from well-differentiated tumor to poorly differentiated ones, but this difference was found to be statistically nonsignificant. D2–40 immunostaining also highlighted the presence of lymphatic invasion present within the tumors which was detected by the presence of tumor emboli within the LVs. Overall, no significant correlation was found between D240 epithelial positivity and LVD.

Conclusion:

The expression of podoplanin in tumor cells and lymphatics when correlated with histopathological status and clinically with the lymph node status can definitely help in the adjuvant therapies used in OSCC.

Propofol prevents the aggressive progression of oral squamous cell carcinoma via regulating circ_0005623/miR-195-5p/HOXB7 axis

Oral squamous cell carcinoma (OSCC) is a general oral disease with high mortality. This study aimed to investigate the effects and underlying mechanism of propofol in OSCC. Propofol treatment inhibited cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT), but promoted apoptosis and induced cell cycle arrest in OSCC cells. miR-195-5p was a target of circ_0005623 and directly targeted to HOXB7. Circ_0005623 and HOXB7 were upregulated, while miR-195-5p was downregulated in OSCC tissues and cells. Overexpression of circ_0005623 partly reversed the effects of propofol on cell proliferation, migration invasion, EMT, cell cycle progression, and apoptosis in SCC-9 and CAL-27 cells. Meanwhile, further investigation uncovered that circ_0005623 could act as a sponge for miR-195-5p to regulate HOXB7 expression, thereby mediating the suppression effects of propofol on OSCC cells. In vivo assay suggested that overexpression of circ_0005623 promoted tumor growth, which was inhibited by propofol treatment. Taken together, propofol regulated aggressive progression of OSCC via the circ_0005623/miR-195-5p/HOXB7 axis, providing the new train of thoughts for diagnosis and therapy of human OSCC.

Association of lymph vessel density with occult lymph node metastasis and prognosis in oral squamous cell carcinoma

Background

The aims of this study were to determine intra (ILVD) and peritumoral (PLVD) lymphatic vessel density (LVD), and to investigate the relationship of LVD with occult metastasis and prognosis.

Methods

Eighty-seven oral squamous cell carcinomas, in clinical stages I or II, arising in the tongue or floor of the mouth were stained with podoplanin. Lymphatic vessels were quantified in intra and peritumoral areas by sequential analysis and hot spot evaluation. Associations of the ILVD and PLVD with clinicopathologic parameters were determined by Chi-square or Fisher’s exact test. The 5 and 10-year survival rates were calculated by the Kaplan–Meier and compared using the log-rank test.

Results

No significant association was observed between ILVD or PLDV and clinicopathologic variables including occult lymph node metastasis, or clinical follow-up. However, ILVD showed a significant association with regional recurrence (p = 0.040). The perineural invasion was associated with PLVD (p = 0.041). Disease-specific (p = 0.044) and disease-free survivals (p = 0.016) had significant association with PLVD.

Conclusions

The intra or peritumoral lymphatic vessel density had no predictive value for occult lymph node metastasis in the early stages of oral cancer arising in the tongue or floor of mouth.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01459-6.

Tumour cells express functional lymphatic endothelium-specific hyaluronan receptor in vitro and in vivo: Lymphatic mimicry promotes oral oncogenesis?

Lymphatic metastasis represents the main route of tumour cell dissemination in oral squamous cell carcinoma (OSCC). Yet, there are no FDA-approved therapeutics targeting cancer-related lymphangiogenesis to date. The lymphatic vessel endothelial hyaluronic acid receptor 1 (LYVE-1), a specific lymphatic marker, is associated with poor survival in OSCC patients. In this study, we present a potential novel mechanism of lymphatic metastasis in OSCC-lymphatic mimicry (LM), a process whereby tumour cells form cytokeratin⁺/LYVE-1⁺, but podoplanin-negative, mosaic endothelial-like vessels. LM was detected in one-third (20/57; 35.08%) of randomly selected OSCC patients. The LM-positive patients had shorter overall survival (OS) compared to LM-negative group albeit not statistically significant. Highly-metastatic tumour cells formed distinct LM structures in vitro and in vivo. Importantly, the siRNA-mediated knockdown of LYVE-1 not only impaired tumour cell migration but also blunted their capacity to form LM-vessels in vitro and reduced tumour metastasis in vivo. Together, our findings uncovered, to our knowledge, a previously unknown expression and function of LYVE-1 in OSCC, whereby tumour cells could induce LM formation and promote lymphatic metastasis. Finally, more detailed studies on LM are warranted to better define this phenomenon in the future. These studies could benefit the development of targeted therapeutics for blocking tumour-related lymphangiogenesis.

Effects of 6,8-Diprenylgenistein on VEGF-A-Induced Lymphangiogenesis and Lymph Node Metastasis in an Oral Cancer Sentinel Lymph Node Animal Model

BACKGROUND

The major determining factor of prognosis of oral squamous cell carcinoma is cervical lymph node metastasis. 6,8-Diprenylgenistein (6,8-DG), an isoflavonoid isolated from Cudrania tricuspidata has been reported to have anti-microbial and anti-obesity activities. However, its effects on lymphangiogenesis and lymph node metastasis in oral cancer have not yet been reported.

METHODS

To investigate the in vitro inhibitory effects of 6,8-DG on VEGF-A-induced lymphangiogenesis, we performed the proliferation, tube formation, and migration assay using human lymphatic microvascular endothelial cells (HLMECs). RT-PCR, Western blot, immunoprecipitation, ELISA and co-immunoprecipitation assays were used to investigate the expression levels of proteins, and mechanism of 6,8-DG. The in vivo inhibitory effects of 6,8-DG were investigated using an oral cancer sentinel lymph node (OCSLN) animal model.

RESULTS

6,8-DG inhibited the proliferation, migration and tube formation of rhVEGF-A treated HLMECs. In addition, the in vivo lymphatic vessel formation stimulated by rhVEGF-A was significantly reduced by 6,8-DG. 6,8-DG inhibited the expression of VEGF-A rather than other lymphangiogenic factors in CoCl₂-treated SCCVII cells. 6,8-DG inhibited the expression and activation of VEGFR-2 stimulated by rhVEGF-A in HLMECs. Also, 6,8-DG inhibited the activation of the lymphangiogenesis-related downstream signaling factors such as FAK, PI3K, AKT, p38, and ERK in rhVEGF-A-treated HLMECs. Additionally, 6,8-DG inhibited the expression of the hypoxia-inducible factor (HIF-1α), which is involved in the expression of VEGF-A in CoCl₂-treated SCCVII cells, and 6,8-DG inhibited VEGF-A signaling via interruption of the binding of VEGF-A and VEGFR-2 in HLMECs. In the VEGF-A-induced OCSLN animal model, we confirmed that 6,8-DG suppressed tumor-induced lymphangiogenesis and SLN metastasis.

CONCLUSION

These data suggest that 6,8-DG inhibits VEGF-A-induced lymphangiogenesis and lymph node metastasis in vitro and in vivo. Furthermore, the inhibitory effects of 6,8-DG are probably mediated by inhibition of VEGF-A expression in cancer cells and suppression of the VEGF-A/VEGFR-2 signaling pathway in HLMEC. Thus, 6,8-DG could be novel and valuable therapeutic agents for metastasis prevention and treatment of oral cancer.

Hypoxic tumor microenvironment: Implications for cancer therapy

IMPACT STATEMENT

Hypoxia contributes to tumor aggressiveness and promotes growth of many solid tumors that are often resistant to conventional therapies. In order to achieve successful therapeutic strategies targeting different cancer types, it is necessary to understand the molecular mechanisms and signaling pathways that are induced by hypoxia. Aberrant tumor vasculature and alterations in cellular metabolism and drug resistance due to hypoxia further confound this problem. This review focuses on the implications of hypoxia in an inflammatory TME and its impact on the signaling and metabolic pathways regulating growth and progression of cancer, along with changes in lymphangiogenic and angiogenic mechanisms. Finally, the overarching role of hypoxia in mediating therapeutic resistance in cancers is discussed.

Patterns of failure after postoperative intensity-modulated radiotherapy for locally advanced buccal cancer: Initial masticator space involvement is the key factor of recurrence

BACKGROUND

The purpose of this study was to determine failure patterns and clinicopathologic prognostic factors in patients with locally advanced buccal cancer after postoperative intensity-modulated radiotherapy (IMRT).

METHODS

Eighty-two patients with locally advanced (American Joint Committee on Cancer [AJCC] stage III/IV) buccal cancer who underwent surgery followed by postoperative IMRT between January 2007 and October 2012 were retrospectively analyzed.

RESULTS

Eighteen patients had local recurrences as the first recurrent site and 11 had supramandibular notch recurrences; the majority of recurrences were classified as marginal failures. The median time from the first local or regional recurrence to death was 5.9 months. In multivariate analyses of survivals, the initial masticator space involvement was the most important prognostic factor. Masticator space involvement, N classification, and maxillectomy were the significant prognostic predictors for supramandibular notch recurrences.

CONCLUSION

Postoperative IMRT for buccal cancer should not include the surgical beds alone, rather, it should be based on the potential patterns of spread.

Regression of Lingual Lymphatic Vessels in Sodium-restricted Mice

Lymphatic vessel networks can expand and regress, with consequences for interstitial fluid drainage and nutrient supply to tissues, inflammation, and tumor spread. A diet high in sodium stimulates hyperplasia of cutaneous lymphatic capillaries. We hypothesized that dietary sodium restriction would have the opposite effect, shrinking lymphatic capillaries in the tongue. Lingual lymphatic capillary density and size was significantly reduced in mice fed a low-sodium diet (0.03%) for 3 weeks compared with control-fed mice. Blood vessel density was unchanged. Despite lymphatic capillary shrinkage, lingual edema was not observed. The effect on lymphatic capillaries was reversible, as lymphatic density and size in the tongue were restored by 3 weeks on a control diet. Lymphatic hyperplasia induced by a high-sodium diet is dependent on infiltrating macrophages. However, lingual CD68+ macrophage density was unchanged by sodium deficiency, indicating that distinct mechanisms may mediate lymphatic regression. Further studies are needed to test whether dietary sodium restriction is an effective, non-invasive co-therapy for oral cancer.

Lymphatics-associated genes are downregulated at transcription level in non-small cell lung cancer

The present study aimed to verify a possibility of ongoing lymphangiogenesis in non-small cell lung cancer (NSCLC) via examination of mRNA levels of a number of lymphangiogenesis-associated genes in tumors. It was hypothesized that transcriptional activation of these genes would occur in tumors that stimulate new lymphatic vessel formation. The study was performed on 140 pairs of fresh-frozen surgical specimens of cancer and unaffected lung tissues derived from NSCLC stage I-IIIA patients. mRNA levels were evaluated with the reverse transcription-quantitative polymerase chain reaction method and expressed as fold change differences between the tumor and normal tissues. Possible associations between expression and patient clinicopathological characteristics and survival were analyzed. In the NSCLC tissue samples, vascular endothelial growth factor (VEGF) C, VEGFD, VEGFR3, VEGFR2, VEGFR1, lymphatic vessel endothelial hyaluronan receptor 1, integrin subunit α 9, FOX2, neuropilin 2, fibroblast growth factor 2 genes were significantly downregulated (P<0.001 for all) compared with matched normal lung tissues, whereas mRNA levels for VEGFA, spleen associated tyrosine kinase, podoplanin, and prospero homeobox 1 genes were similar in both tissues. Neither lymph node status, nor disease pathological stage influenced expression, whereas more profound suppression of gene activities appeared to occur in squamous cell carcinomas compared with adenocarcinomas. The VEGFR1 mRNA expression level was significantly connected with patient survival in the univariate analysis, and was an independent prognostic factor for overall survival in the multivariate Cox's proportional hazards model (HR 2.103; 95% confidence interval: 1.005-4.401; P=0.049). The results support a hypothesis of absence of new lymphatic vessel formation inside growing NSCLC tumor mass, however do not exclude a possibility of lymphangiogenesis in narrow marginal tumor parts.

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.

Prognostic value of the area and density of lymphatic vessels in cutaneous squamous cell carcinoma

BACKGROUND AND OBJECTIVES

Cutaneous squamous cell carcinoma (SCC) is known for its capacity to metastasize via lymphatic vessels. In recent studies, the level of lymphangiogenesis has been reported as a potential prognostic factor for several skin tumors. The aim of this study was to quantify lymphangiogenesis in SCC using either computer-assisted image analysis or the Chalkley count technique. Vascular parameters were evaluated and compared with respect to their predictive power for tumor metastasis.

PATIENT AND METHODS

In this case-control study, clinical and histological data of 15 metastatic and 15 nonmetastatic SCC patients were retrospectively analyzed. SCC samples were immunostained for the lymphatic endothelial marker D2-40 and the panvascular marker CD31, and analyzed using computer-assisted morphometric image analyses within hot spots as well as the digitalized Chalkley counting method.

RESULTS

Lymphatic vessel density, relative lymphatic vessel area, and lymphatic Chalkley count were significantly elevated in metastatic SCC. Tumor thickness was significantly higher in metastatic SCC, and had the highest predictive power for metastatic disease. Tumor thickness was a significant predictor of lymphangiogenic parameters.

CONCLUSIONS

Lymphangiogenesis is elevated in metastatic SCC but its extent is influenced by tumor thickness. Tumor thickness remains the most reliable predictive factor for metastatic disease.

Lymphangiogenesis in Oral Squamous Cell Carcinoma: Correlation with VEGF-C Expression and Lymph Node Metastasis

Background

Oral squamous cell carcinoma (OSCC) is the most common oral malignancy that preferentially spreads to the cervical lymph node which, when involved, complicates the anticancer therapy and threatens the patient life. It was suggested that lymph node metastasis may be facilitated by lymphangiogenesis. VEGF-C is one of the most important lymphangiogenic inducers that promotes the lymphatic vessels growth and supports the survival of adult lymphatic endothelial cells.

Methods

Lymphatic vessels density (LVD) and LV morphometry were digitally evaluated using D2-40. The expression of VEGF-C was also assessed using immunohistochemistry and real-time polymerase chain reaction in 6 normal oral mucosa cases and 72 cases of OSCC. The correlation between LVD and LV morphometry, VEGF-C, and lymph node metastasis was statistically assessed.

Results

A positive cytoplasmic expression of VEGF-C was detected in both epithelial and connective tissue cells in 97% of OSCC, while all normal tissues reacted negatively. A greater expression of VEGF-C was associated with larger and more dilated LV and lymph node metastasis but not with LVD.

Conclusion

VEGF-C is actively involved in the invasion and metastasis of OSCC via inducing morphological changes in LV. VEGF-C may be a promising target for anticancer therapy.

Osteopontin is Critical for Hyperactive mTOR-Induced Tumorigenesis in Oral Squamous Cell Carcinoma

Mechanistic target of rapamycin (mTOR) plays a critical role in the development of oral squamous cell carcinoma (OSCC), but the underlying mechanisms remain poorly understood. Here we have demonstrated that the expression of osteopontin (OPN) was dramatically up-regulated in OSCC tissues and cell lines. Moreover, reduction of OPN suppressed cell proliferation, colony formation, and in vivo tumorigenic ability of OSCC cell lines Tca8113. In addition, there was a strong positive correlation between mTORC1 activity and OPN expression in OSCC tissues and cell lines. Furthermore, mTOR complex 1 (mTORC1) enhanced OPN expression through up-regulation of ERRα. Therefore, OPN is a downstream target of mTORC1 and is crucial for OSCC development. mTORC1, ERRα, and OPN may be potential targets for treatment of OSCC with aberrant mTORC1 signaling.

Immunohistochemical comparative analysis of lymphatic vessel density and VEGF-C expression in squamous cell carcinomas of the tongue between young and old patients

BACKGROUND

Squamous cell carcinoma (SCC) of the oral cavity is a malignant epithelial tumor that most commonly involves the tongue, and mainly affects men between the fifth and seventh decades of life. This study compared the lymphatic vessel density and VEGF-C expression in SCCs of the tongue between young and old patients.

METHODS

Thirty-four SCCs of the tongue, 17 diagnosed in young patients (≤40y) and 17 diagnosed in old patients (>50y), were evaluated by immunohistochemistry. Lymphatic microdensity was determined based on the number of vessels immunoreactive to anti-D2-40 antibody. The percentage of neoplastic cells exhibiting cytoplasmic staining for VEGF-C was established for each case.

RESULTS

Assessment of intratumoral lymphatic microdensity (ILMD) disclosed a median number of 6.20 lymphatic vessels in young patients and of 6.60 in old patients (p=0.809). Analysis of peritumoral lymphatic microdensity (PLMD) revealed a median number of 3.60 lymphatic vessels in young patients and of 3.40 in old patients (p=0.769). In the tumor core, analysis of the percentage of immunopositive cells for VEGF-C revealed a median number of 95.95% in young patients and of 55.48% in old patients (p<0.001). In the deep invasive front, the median number of immunopositive cells for VEGF-C was 97.93% in young patients and 66.09% in old patients (p<0.001).

CONCLUSIONS

The results of this study suggest that the more aggressive biological behavior of SCC of the tongue in young patients may be related to a higher expression of VEGF-C.

Recombinant canstatin inhibits VEGF-A-induced lymphangiogenesis and metastasis in an oral squamous cell carcinoma SCC-VII animal model

We describe the inhibitory effects of recombinant canstatin on tumor growth and lymphangiogenesis induced by an oral squamous cell carcinoma (SCC) using an orthotropic oral SCC animal model. Recombinant canstatin treatment decreased final tumor volumes and weights, as well as densities of blood and lymphatic vessels. Lung metastasis of oral SCC was significantly reduced in recombinant canstatin‐treated animals. Recombinant canstatin reduced vascular endothelial growth factor (VEGF)‐A expression in SCC‐VII cells treated with the hypoxia mimetic agent, CoCl₂. VEGF‐A induced in vivo lymphatic vessel formation in a Matrigel plug, but this was remarkably reduced in a recombinant canstatin‐treated Matrigel. Recombinant canstatin suppressed the expression of vascular endothelial growth factor receptors (VEGFR)‐1 and ‐2 stimulated by VEGF‐A. Based on immunohistochemical analysis, recombinant canstatin significantly reduced the expression of VEGF‐A, VEGFR‐1, and ‐2 in SCC‐VII‐induced tumors. Recombinant canstatin did not affect the expression of VEGF‐C or VEGFR‐3. In addition, recombinant canstatin suppressed the VEGF‐A‐induced phosphorylation of VEGFR‐1 and ‐2. Our results indicate that recombinant canstatin exhibits antitumoral and antilymphangiogenic activities against oral SCC cells. Antilymphangiogenic signaling by recombinant canstatin is probably mediated by the suppression of the integrin αvβ3/VEGFR‐1 and/or ‐2 signaling induced by VEGF‐A. Our results also suggest that recombinant canstatin has a high potential to inhibit oral SCC‐induced tumors and lymphatic metastasis.

Tumour cell-derived WNT5B modulates in vitro lymphangiogenesis via induction of partial endothelial-mesenchymal transition of lymphatic endothelial cells

Metastasis of the cervical lymph nodes frequently leads to poor survival of patients with oral squamous cell carcinoma (OSCC). The underlying mechanisms of lymph node metastasis are unclear. Wingless-type MMTV integration site family, member 5B (WNT5B), one component of the WNT signal pathway, was markedly up-regulated in OSCC sublines with high potential of lymphatic metastasis compared to that in OSCC cells with low nodal metastasis. Increased WNT5B mRNA was demonstrated in human OSCC tissues in comparison with adjacent non-tumorous tissues. Interestingly, the high level of WNT5B protein in serum was associated with lymph node metastasis in OSCC patients. Knockdown of WNT5B expression in OSCC sublines did not affect tumour growth but impaired lymph node metastasis and tumour lymphangiogenesis of orthotopic transplantation. Conditioned medium from WNT5B knockdown cells reduced the tube formation of lymphatic endothelial cells (LECs). In contrast, recombinant WNT5B enhanced the tube formation, permeability and migration of LECs. In LECs stained with phalloidin, the morphology of those treated with recombinant WNT5B changed from flat to spindle-like. Recombinant WNT5B also increased α-smooth muscle actin and inhibited the expression of vascular endothelial-cadherin but retained characteristics of endothelial cells. The results suggest that WNT5B functions in the partial endothelial-mesenchymal transition (EndoMT). Furthermore, WNT5B-induced tube formation was impaired in the LECs following the knockdown of EndoMT-related transcription factor, SNAIL or SLUG. The WNT5B-induced expression of Snail or Slug was abolished by IWR-1-endo and Rac1 inhibitors, which are involved in the WNT/β-catenin and planar cell polarity pathways, respectively. Collectively, the data suggest that WNT5B induces tube formation by regulating the expression of Snail and Slug proteins through activation of canonical and non-canonical WNT signalling pathways.

Prognostic value of matrix metalloproteinase-9 expression in oral squamous cell carcinoma and its association with angiogenesis

Background

Breakdown of extracellular matrix (ECM) is one of the important hallmarks of cancer progression which facilitates the invasion of tumoral cells to the surrounding tissue. Matrix metalloproteinases (MMPs) can degrade various components of the ECM and basement membrane. The aim of this study was to determine the role of matrix metalloproteinases-9 protein in the biologic behavior of oral squamous cell carcinoma (OSCC) and its relation with tumor angiogenesis.

Material and Methods

In this study 42 OSCC and 15 normal epithelium were reviewed by immunohistochemical staining for matrix metalloproteinases-9 and CD105.

Results

Matrix metalloproteinases-9 expression was detected in 32 OSCC specimens (76.1%), with 28 specimens (66.6%) showing moderate or strong expression. We observed that the expression level of matrix metalloproteinases-9 was positively correlated with the status of lymph node metastasis (N0vs. N1) (P =0.00), and clinical stage (I-II vs. III-IV) in OSCC patients. Microvessel density in intratumoral tissue has an association with lymph node metastasis and advanced clinical stage (P=0.003 and p=0.01, respectively). We observed that tumors with matrix metalloproteinases-9 overexpression had a higher microvessel density counts compared with tumors with absent or focal immunostaining(16.2±5.6 vs 10.3±3.5 respectively, P =0.03).

Conclusions

In conclusion present results demonstrate the marked expression of matrix metalloproteinases-9 and CD105 in OSCC and suggest that the expression of these markers is associated with tumor progression and could offer additional information about the aggressiveness of OSCC. In addition a significant relationship was noted between microvessel density count and expression of matrix metalloproteinases-9 which suggest that MMP9 expression may be closely related to tumor angiogenesis.

Key words:Matrix metalloproteinases-9, CD105, squamous cell carcinoma, immunohistochemistry.

Neuropilin 1 Receptor Is Up-Regulated in Dysplastic Epithelium and Oral Squamous Cell Carcinoma

Neuropilins are receptors for disparate ligands, including proangiogenic factors such as vascular endothelial growth factor and inhibitory class 3 semaphorin (SEMA3) family members. Differentiated cells in skin epithelium and cutaneous squamous cell carcinoma highly express the neuropilin-1 (NRP1) receptor. We examined the expression of NRP1 in human and mouse oral mucosa. NRP1 was significantly up-regulated in oral epithelial dysplasia and oral squamous cell carcinoma (OSCC). NRP1 receptor localized to the outer suprabasal epithelial layers in normal tongue, an expression pattern similar to the normal skin epidermis. However, dysplastic tongue epithelium and OSCC up-regulated NRP1 in basal and proliferating epithelial layers, a profile unseen in cutaneous squamous cell carcinoma. NRP1 up-regulation is observed in a mouse carcinogen-induced OSCC model and in human tongue OSCC biopsies. Human OSCC cell lines express NRP1 protein in vitro and in mouse tongue xenografts. Sites of capillary infiltration into orthotopic OSCC tumors correlate with high NRP1 expression. HSC3 xenografts, which express the highest NRP1 levels of the cell lines examined, showed massive intratumoral lymphangiogenesis. SEMA3A inhibited OSCC cell migration, suggesting that the NRP1 receptor was bioactive in OSCC. In conclusion, NRP1 is regulated in the oral epithelium and is selectively up-regulated during epithelial dysplasia. NRP1 may function as a reservoir to sequester proangiogenic ligands within the neoplastic compartment, thereby recruiting neovessels toward tumor cells.

Immunohistochemical predictors in squamous cell carcinoma of the tongue and floor of the mouth

BACKGROUND

The purpose of this study was to evaluate the clinical usefulness of the immunoexpression of Ki-67, matrix metalloproteinase (MMP)-2, MMP-9, vascular endothelial growth factor (VEGF)-C, and VEGF-D in predicting follow-up treatment in patients with squamous cell carcinoma (SCC) of the tongue and floor of the mouth (FOM).

METHODS

Marker expression was evaluated in surgical specimens taken from 60 patients who underwent surgery because of primary SCC without prior therapy.

RESULTS

Strong MMP-2 expression was positively correlated with a higher risk of nodal recurrence (p = .047). Strong VEGF-C expression was found in patients with distant metastases (p = .008). Cox's regression model showed high Ki-67, MMP-2, and VEGF-C expression, which were independent predictors of disease-specific survival (p = .001, p = .002, and p < .001, respectively).

CONCLUSION

It seems that targeting MMP-2 and VEGF-C may improve local control, thereby reducing the risk of distant metastasis in patients with SCC of the tongue and FOM. © 2015 Wiley Periodicals, Inc. Head Neck 38: E747-E753, 2016.

The Role of Podoplanin in the Lymphangiogenesis of Oral Squamous Carcinomas

Oral squamous cells carcinoma (OSCC) mortality rate ranges between 29-40/100,000 inhabitants. Regional lymph node metastases occur in 30-40% cases and are associated with unfavorable prognosis and decreased survival. Recentely it was suggested that the tumor-associated lymphatic vessels formation plays an active role in metastasis proces of several human malignancies, including OSCC. In the present study we investigated comparatively podoplanin immunoexpression in OSCC in both the tumor cells and lymphatic vessels reported to clinicopathological prognostic parameters. Material and methods The study included a total of 25 cases of OSCC. We investigated clinico-pathological parameters as age, gender, tumor site, and degree of differentiation, size and depth of invasion (pT), lymph node status (pN). Histologic classification was done according to the WHO criteria. For immunohistochemical (IHC) analysis we used podoplanin (Dako, clone D2-40). As visualization system it was used LSAB2 (Dako, Redox, Romania, code K0675) and chromogen DAB (Dako, Redox, Romania, code K3468). Negative controls were obtained by omitting the primary antibodies. IHC quantification was done intensity score and by lymphatic microdensity (LVD), intratumoral and on the advancing edge. For the statistical analysis we used Student's t-tests, ANOVA, chi square and Pearson, using SPSS 10 software. Results Podoplanin immunoexpression in tumor parenchyma presented with an average of 43%, varying intensity. We found a higher intensity in weak and moderately differentiated SCC then in well differentiated ones and no difference intratumoral aand advancing edge. In relation to the degree of tumor differentiation the mean LVD D2-40 was higher in the advancing edge. SCC who presented lymph node metastasis mean values for LVD D2-4 was higher then at advancing edge and higher than those of non-metastatic carcinomas. Conclusions Podoplanin immunoexpresion suggests the involvement both in tumor growth and the acquisition of an lymphangiogenic phenotype invasive by autocrine mechanisms.

Heterogeneous tumor stromal microenvironments of oral squamous cell carcinoma cells in tongue and nodal metastatic lesions in a xenograft mouse model

BACKGROUND

Oral squamous cell carcinoma exhibits a poor prognosis, caused by aggressive progression and early-stage metastasis to cervical lymph nodes. Here, we developed a xenograft mouse model to explore the heterogeneity of the tumor microenvironment that may govern local invasion and nodal metastasis of tumor cells.

METHODS

We transplanted five oral carcinoma cell lines into the tongues of nude mice and determined tongue tumor growth and micrometastatic dissemination by serially sectioning the tongue and lymph node lesions in combination with immunohistochemistry and computer-assisted image analysis. Our morphometric analysis enabled a quantitative assessment of blood and lymphatic endothelial densities in the intratumoral and host stromal regions.

RESULTS

All cell lines tested were tumorigenic in mouse tongue. The metastatic lesion-derived carcinoma cell lines (OSC19, OSC20, and HSC2) yielded a 100% nodal metastasis rate, whereas the primary tumor-derived cell lines (KOSC2 and HO-1-u-1) showed <40% metastatic potential. Immunohistochemistry showed that the individual cell lines gave rise to heterogeneous tumor architecture and phenotypes and that their micrometastatic lesions assimilated the immunophenotypic properties of the corresponding tongue tumors. Notably, OSC19 and OSC20 cells shared similar aggressive tumorigenicity in both the tongue and lymph node environments but displayed markedly diverse immunophenotypes and gene expression profiles.

CONCLUSIONS

Our model facilitated comparing the tumor microenvironments in tongue and lymph node lesions. The results support that tumorigenicity and tumor architecture in the host tongue environment depend on the origin and properties of the carcinoma cell lines and that metastatic progression may take place through heterogeneous tumor-host interactions.

Impact of the prolymphangiogenic crosstalk in the tumor microenvironment on lymphatic cancer metastasis

Lymphangiogenesis is a very early step in lymphatic metastasis. It is regulated and promoted not only by the tumor cells themselves, but also by cells of the tumor microenvironment, including cancer associated fibroblasts, mesenchymal stem cells, dendritic cells, or macrophages. Even the extracellular matrix as well as cytokines and growth factors are involved in the process of lymphangiogenesis and metastasis. The cellular and noncellular components influence each other and can be influenced by the tumor cells. The knowledge about mechanisms behind lymphangiogenesis in the tumor microenvironmental crosstalk is growing and offers starting points for new therapeutic approaches.

Head and neck squamous cell carcinoma lymphatic spread and survival: Relevance of vascular endothelial growth factor family for tumor evaluation

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is primarily a locoregional disease in which the cervical lymph nodes are the chief site of metastasis. The purpose of this study was to examine the relationship between lymphangiogenesis and clinicopathological aspects of HNSCC and its metastasis.

METHODS

Fifty-two patients with HNSCC and metastatic lymph nodes from 21 of these subjects were analyzed by immunohistochemistry.

RESULTS

The HNSCC samples were predominantly negative for vascular endothelial growth factor (VEGF)-C, VEGF-D, and vascular endothelial growth factor receptor (VEGFR)3. There was an association between the density of lymph vessels (measured by D2-40 staining) in the lymph nodes and advanced-stage tumors. There was no link between the expression of these proteins and survival rates.

CONCLUSION

Although lymphatic spread is a significant event in the progression of HNSCC, the expression of VEGF-C, VEGF-D, and VEGFR3 does not correlate with clinicopathological characteristics, suggesting that other signaling pathways mediate lymphangiogenesis in HNSCC.

Metastasis via Peritumoral Lymphatic Dilation in Oral Squamous Cell Carcinoma

PURPOSE

Nodal metastasis is the main prognostic factor in the patients with oral squamous cell carcinoma (OSCC). We investigated the association between tumor-associated lymphatics and OSCC characteristics.

METHODS

Thirty-four specimens were used for the immunohistochemical staining with the antibody for vascular endothelial growth factor (VEGF)-C, VEGF-D, VEGF receptor (VEGFR)-3, phosphorylated VEGFR-3, D2-40, and matrix metallproteinases (MMPs). We observed the distribution of the lymphangiogenic factors and quantified the degree of expression. We determined lymphatic vessel density (LVD) and lymphatic vessel dilatation with D2-40 immunostaining. We assessed the association of LVD or lymphatic vessel dilatation with tumor progression or tumor differentiation.

RESULTS

OSCC cells expressed lymphangiogenic ligands. Lymphangiogenic receptor, VEGFR-3, was expressed and activated in some tumor cells as well as in tumor-associated endothelial cells. LVD was not associated with tumor size or nodal status, but lymphatic vessel dilatation was higher in tumors with nodal metastasis, and also higher in poorly differentiated tumors. In stromal area of OSCC, MMP-1 and MMP-10 were up-regulated and the basement membrane of tumor-associated endothelial cells was destroyed by these collagenases.

CONCLUSION

In the primary tumors with nodal metastasis, especially in poorly differentiated OSCC, tumor cells invaded the dilated lymphatic vessels via ruptured sites. MMP-1 and MMP-10 are important in the lysis of the glycocalyx inside the tumor-associated lymphatic endothelial cells.

Prox1 and FOXC2 act as regulators of lymphangiogenesis and angiogenesis in oral squamous cell carcinoma

Prospero homeobox 1 (Prox1) and forkhead box (FOX) C2 regulate angiogenesis and/or lymphangiogenesis. However, the detailed role and function of Prox1 and FOXC2 in cancer remains controversial. In the present study, we examined the expression of Prox1 and FOXC2 proteins in specimens from 163 cases with oral squamous cell carcinoma (OSCC). Furthermore, the role of Prox1 and FOXC2 in cancer cell growth and invasion was evaluated in cultured OSCC cells. Prox1 expression was significantly associated with local progression of the tumor (P = 0.0023), clinical stage (P<0.0001), lymphovessel density (LVD) (P<0.0001), nodal metastasis (P<0.0001), and worse prognosis (P<0.0001). Immunoreactivity of FOXC2 was strongly correlated with microvessel density (MVD) (P<0.0001) and poor prognosis (P = 0.0076). In vitro analysis demonstrated that Prox1 regulates cell growth, proliferation, invasion, and lymphangiogenesis by activating vascular endothelial growth factor (VEGF)-C expression. Furthermore, FOXC2 enhanced the expression level of Prox1 and promoted angiogenesis by enhancement of VEGF-A expression. Our results suggested that Prox1 and FOXC2 play key roles in OSCC progression and that further studies focusing on these proteins may yield useful insights for diagnosis and therapy of OSCC.