Prognostic significance of epithelial-mesenchymal transition of extracapsular spread tumors in lymph node metastases of head and neck cancer

Mechanism of Tumor Budding in Patient-Derived Metachronous Oral Primary Squamous Cell Carcinoma Cell Lines

Tumor budding (TB) occurs at the deepest site of tumor invasion and is a significant prognostic indicator of cervical metastasis in oral squamous cell carcinoma (OSCC). The mechanism of TB, however, remains unclear. This study investigated the roles of the tumor microenvironment and partial epithelial-mesenchymal transition (p-EMT) in TB expression using molecular and cellular physiological analyses. We established oral metachronous carcinoma cell lines (gingival carcinoma: 020, tongue carcinoma with high TB expression: 020G) from two cancers with pathologically different TB in the same patient and subjected them to exome analysis to detect gene mutations related to carcinogenesis and malignancy. Differences in EMT expression induced by transforming growth factor-β (TGF-β) between 020 and 020G were analyzed by Western blotting and reverse transcription polymerase chain reaction, and TGF-β-induced changes in cell morphology, proliferation, migration, and invasive ability were also examined. TGF-β expression was observed in the deepest tumor invasion microenvironment. TGF-β also induced the expression of several p-EMT markers and increased the migration and invasive abilities of 020G compared with 020 cells. In conclusion, TGF-β in the deep-tumor microenvironment can induce p-EMT in tumor cells, expressed as TB.

Protective Effect of Alpha-Linolenic Acid on Human Oral Squamous Cell Carcinoma Metastasis and Apoptotic Cell Death

Oral cancer ranks sixth among Taiwan's top 10 cancers and most patients with poor prognosis acquire metastases. The essential fatty acid alpha-linolenic acid (ALA) has been found to diminish many cancer properties. However, the anti-cancer activity of ALA in oral cancer has yet to be determined. We examined the mechanisms underlying ALA inhibition of metastasis and induction of apoptotic cell death in oral squamous cell carcinoma (OSCC). Migration and invasion assays confirmed the cancer cells' EMT capabilities, whereas flow cytometry and Western blotting identified molecular pathways in OSCC. ALA dramatically reduced cell growth in a concentration-dependent manner according to the findings. Low concentrations of ALA (100 or 200 μM) inhibit colony formation, the expression of Twist and EMT-related proteins, the expression of MMP2/-9 proteins, and enzyme activity, as well as cell migration and invasion. Treatment with high concentrations of ALA (200 or 400 μM) greatly increases JNK phosphorylation and c-jun nuclear accumulation and then upregulates the FasL/caspase8/caspase3 and Bid/cytochrome c/caspase9/caspase3 pathways, leading to cell death. Low concentrations of ALA inhibit SAS and GNM cell migration and invasion by suppressing Twist and downregulating EMT-related proteins or by decreasing the protein expression and enzyme activity of MMP-2/-9, whereas high concentrations of ALA promote apoptosis by activating the JNK/FasL/caspase 8/caspase 3-extrinsic pathway and the Bid/cytochrome c/caspase 9 pathway. ALA demonstrates potential as a treatment for OSCC patients.

Prognostic significance of extranodal extension of nodal metastasis in adenocarcinoma of the ampulla of Vater

Although nodal metastasis (NM) is an important prognostic factor of ampullary adenocarcinoma, the prognostic implication of extranodal extension (ENE) is not well characterized. NM with ENE status was investigated in 279 surgically resected ampullary adenocarcinoma patients and compared with other clinicopathologic factors, including overall survival (OS) and recurrence-free survival (RFS). Expression of epithelial-mesenchymal transition (EMT) markers, including E-cadherin, Twist, and Snail, was assessed in a subset of the cohort. NM was observed in 94 cases (33.7%), of which ENE was observed in 32 cases (34%). NM with ENE was more frequently associated with tumors with poor differentiation than NM without ENE (P = .017). The 5-year OS and RFS rates of patients with NM and ENE was significantly worse (13.0% and 6.3%) than those with NM without ENE (37.7% and 21.4%) and those without NM (57.6% and 50.2%, respectively; P < .001). When pN category was matched, the OS and RFS was worse in patients with ENE than in those without ENE (P < .05). Moreover, the expression of E-cadherin and Twist was significantly different between NM areas with and without ENE (all, P < .001). Since ENE was associated with poorly differentiated ampullary adenocarcinomas and showed different expression of EMT markers, EMT could be a possible mechanism of ENE. Ampullary adenocarcinoma patients with ENE had worse OS and RFS than those without ENE. Therefore, evaluation of ENE can provide additional survival information for patients with surgically resected ampullary carcinoma.

Partial EMT in head and neck cancer biology: a spectrum instead of a switch

Our understanding of epithelial-to-mesenchymal transition (EMT) has slowly evolved from a simple two state, binary model to a multi-step, dynamic continuum of epithelial-to-mesenchymal plasticity, with metastable intermediate transition states that may drive cancer metastasis. Head and neck cancer is no exception, and in this review, we use head and neck as a case study for how partial-EMT (p-EMT) cell states may play an important role in cancer progression. In particular, we summarize recent in vitro and in vivo studies that uncover these intermediate transition states, which exhibit both epithelial and mesenchymal properties and appear to have distinct advantages in migration, survival in the bloodstream, and seeding and propagation within secondary metastatic sites. We then summarize the common and distinct regulators of p-EMT as well as methodologies for identifying this unique cellular subpopulation, with a specific emphasis on the role of cutting-edge technologies, such as single cell approaches. Finally, we propose strategies to target p-EMT cells, highlighting potential opportunities for therapeutic intervention to specifically target the process of metastasis. Thus, although significant challenges remain, including numerous gaps in current knowledge, a deeper understanding of EMT plasticity and a genuine identification of EMT as spectrum rather than a switch will be critical for improving patient diagnosis and treatment across oncology.

Prognostic Impact of Extranodal Extension in Rectal Cancer Patients Undergoing Radical Resection After Preoperative Chemoradiotherapy

BACKGROUND

Extranodal extension (ENE) of nodal metastasis has emerged as an important prognostic factor in many malignancies, including rectal cancer. However, its significance in patients with rectal cancer receiving preoperative chemoradiotherapy (PCRT) has not been extensively investigated. We therefore assessed ENE and its prognostic impact in a large series of consecutive rectal cancer patients with lymph node metastasis after PCRT and curative resection.

PATIENTS AND METHODS

Between January 2000 and December 2014, a total of 1925 patients with rectal cancer underwent surgical resection after PCRT. Medical records of 469 patients with pathologic node positivity were retrospectively reviewed.

RESULTS

Of the 469 patients, 118 (25.2%) presented with ENE. ENE was observed more frequently in those with advanced tumor stage (higher ypT, ypN, and ypStage), lymphovascular invasion, and perineural invasion. Five-year disease-free survival rate was lower in patients with ENE-positive tumors than those with ENE-negative tumors (36.1% vs. 52.3%, P = .003). Similarly, 5-year overall survival rate was lower in patients with ENE-positive tumors than those with ENE-negative tumors (60.2% vs. 70.6%, P < .001). Multivariate analysis revealed that the presence of ENE was an independent poor prognostic factor for disease-free survival (hazard ratio = 1.412; 95% confidence interval, 1.074-1.857; P = .013) and overall survival (hazard ratio = 1.531; 95% confidence interval 1.149-2.039; P = .004).

CONCLUSION

The presence of ENE in patients with rectal cancer undergoing PCRT is a negative prognostic factor, reflecting poor survival outcome.

An Epithelial-Mesenchymal Transition (EMT) Preoperative Nomogram for Prediction of Lymph Node Metastasis in Bladder Cancer (BLCA)

Lymph node (LN) metastasis is a lethal independent risk factor for patients with bladder cancer (BLCA). Accurate evaluation of LN metastasis is of vital importance for disease staging, treatment selection, and prognosis prediction. Several histopathologic parameters are available to predict LN metastasis postoperatively. To date, medical imaging techniques have made a great contribution to preoperatively diagnosis of LN metastasis, but it also exhibits substantial false positives. Therefore, a reliable and robust method to preoperatively predict LN metastasis is urgently needed. Here, we selected 19 candidate genes related to epithelial-mesenchymal transition (EMT) across the LN metastasis samples, which was previously reported to be responsible for the subtype transition and correlation with malignancy and prognosis of BLCA, to establish an EMT-LN signature through LASSO logistic regression analysis. The EMT-LN signature could significantly predict LN metastasis with high accuracy in the TCGA-BLCA cohort, as well as several independent cohorts. As integrating with C3orf70 mutation, we developed an individualized prediction nomogram based on the EMT-LN signature. The nomogram exhibited good discrimination on LN metastasis status, with AUC of 71.7% and 75.9% in training and testing datasets of the TCGA-BLCA cohort. Moreover, the EMT-LN nomogram displayed good calibration with p > 0.05 in the Hosmer-Lemeshow goodness of fit test. Decision curve analysis (DCA) revealed that the EMT-LN nomogram was of high potential for clinical utility. In summary, we established an EMT-LN nomogram integrating an EMT-LN signature and C3orf70 mutation status, which acted as an easy-to-use tool to facilitate preoperative prediction of LN metastasis in BLCA individuals.

Machine Learning Prediction of Extracapsular Extension in Human Papillomavirus-Associated Oropharyngeal Squamous Cell Carcinoma

OBJECTIVE

To determine whether machine learning (ML) can predict the presence of extracapsular extension (ECE) prior to treatment, using common oncologic variables, in patients with human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC).

STUDY DESIGN

Retrospective database review.

SETTING

National Cancer Database study.

METHODS

All patients with HPV-associated OPSCC treated surgically between January 1, 2010, and December 31, 2015, were selected from the National Cancer Database. Patients were excluded if surgical pathology reports did not include information regarding primary tumor stage, number of metastatic regional lymph nodes, size of largest metastatic regional lymph node, and tumor grade. The data were split into a random distribution of 80% for training and 20% for testing with ML methods.

RESULTS

A total of 3753 adults with surgically treated HPV-associated OPSCC met criteria for inclusion in the study. Approximately 38% of these patients treated with surgical management demonstrated ECE. ML models demonstrated modest accuracy in predicting ECE, with the areas under the receiver operating characteristic curves ranging from 0.58 to 0.68. The conditional inference tree model (0.66) predicted the metastatic lymph node number to be the most important predictor of ECE.

CONCLUSION

Despite a large cohort and the use of ML algorithms, the power of clinical and oncologic variables to predict ECE in HPV-associated OPSCC remains limited.

Development and validation of a multivariable prediction model for the identification of occult lymph node metastasis in oral squamous cell carcinoma

BACKGROUND

There have been few recent advances in the identification of occult lymph node metastases (OLNM) in oral squamous cell carcinoma (OSCC). This study aimed to develop, compare, and validate several machine learning models to predict OLNM in clinically N0 (cN0) OSCC.

METHODS

The biomarkers CD31 and PROX1 were combined with relevant histological parameters and evaluated on a training cohort (n = 56) using four different state-of-the-art machine learning models. Next, the optimized models were tested on an external validation cohort (n = 112) of early-stage (T1-2 N0) OSCC.

RESULTS

The random forest (RF) model gave the best overall performance (area under the curve = 0.89 [95% CI = 0.8, 0.98]) and accuracy (0.88 [95% CI = 0.8, 0.93]) while maintaining a negative predictive value >95%.

CONCLUSIONS

We provide a new clinical decision algorithm incorporating risk stratification by an RF model that could significantly improve the management of patients with early-stage OSCC.

Epithelial-to-Mesenchymal Transition and MicroRNAs in Lung Cancer

Despite major advances, non-small cell lung cancer (NSCLC) remains the major cause of cancer-related death in developed countries. Metastasis and drug resistance are the main factors contributing to relapse and death. Epithelial-to-mesenchymal transition (EMT) is a complex molecular and cellular process involved in tissue remodelling that was extensively studied as an actor of tumour progression, metastasis and drug resistance in many cancer types and in lung cancers. Here we described with an emphasis on NSCLC how the changes in signalling pathways, transcription factors expression or microRNAs that occur in cancer promote EMT. Understanding the biology of EMT will help to define reversing process and treatment strategies. We will see that this complex mechanism is related to inflammation, cell mobility and stem cell features and that it is a dynamic process. The existence of intermediate phenotypes and tumour heterogeneity may be debated in the literature concerning EMT markers, EMT signatures and clinical consequences in NSCLC. However, given the role of EMT in metastasis and in drug resistance the development of EMT inhibitors is an interesting approach to counteract tumour progression and drug resistance. This review describes EMT involvement in cancer with an emphasis on NSCLC and microRNA regulation.

Study of fluid dynamics reveals direct communications between lymphatic vessels and venous blood vessels at lymph nodes of mice

Cancer cells metastasize to lymph nodes, with distant metastasis resulting in poor prognosis. The role of lymph node metastasis (LNM) in the spread of cancer to distant organs remain incompletely characterized. The visualization of flow dynamics in the lymphatic and blood vessels of MXH10/Mo-lpr/lpr mice, which develop systemic swelling of lymph nodes up to 10mm in diameter, has revealed that lymph nodes have the potential to be a direct source of systemic metastasis. However, it is not known whether these fluid dynamics characteristics are universal phenomena present in other strains of laboratory mice. Here we show that the fluid dynamics observed in MXH10/Mo-lpr/lpr mice are the same as those observed in C57BL/6J, BALB/cAJcl and NOD/ShiJic-scidJcl mice. Furthermore, when fluorescent solution was injected into a tumor-bearing lymph node, the flow dynamics observed in the efferent lymphatic vessels and thoracoepigastric vein depended on the type of tumor cell. Our results indicate that fluid dynamics in the lymphatic and blood vessels of MXH10/Mo-lpr/lpr mice are generalized phenomena seen in conventional laboratory mice. We anticipate our results can facilitate studies of the progression of lymphatic metastasis to hematogenous metastasis via lymph nodes and the early diagnosis and treatment of LNM.

Prognostic Significance of Expression of the Epithelial-Mesenchymal Transition-Related Factor Brachyury in Intrathoracic Lymphatic Spread of Non-Small Cell Lung Cancer

BACKGROUND

Brachyury is a transcriptional regulator that plays important roles in epithelial mesenchymal transition (EMT) during development and has been reported to be essential for mesoderm formation in the early human embryo. We investigated Brachyury protein expression in hilar and mediastinal metastatic lymph nodes of non-small cell lung cancer patients and the prognostic significance of Brachyury expression at metastatic sites.

METHODS

Expression of Brachyury in 115 surgically resected primary lung cancer and corresponding metastatic lymph node samples was evaluated by immunohistochemical staining. The relationships between Brachyury protein expression and the patient's clinicopathological factors and prognosis were analyzed.

RESULTS

Brachyury expression in metastatic lymph nodes was significantly higher than that in the primary tumor (p = 0.012). Patients with high Brachyury expression in the metastatic lymph nodes had significantly poor prognoses (p = 0.0236) compared with patients with low expression. In addition, patients with larger differences in Brachyury expression between metastatic lymph nodes and the primary tumor had significantly poorer prognoses compared with patients with smaller differences (p = 0.0146). The Brachyury protein expression level in metastatic lymph nodes was significantly associated with the protein expression levels of other EMT-related factors (E-cadherin [inverse association], p = 0.0265; Slug, p = 0.029; and interleukin-8, p = 0.0135).

CONCLUSIONS

High expression of Brachyury protein in metastatic carcinoma cells in the intrathoracic lymph nodes was associated with poor prognosis of lung cancer patients. Increased Brachyury expression during the metastatic process may confer further potential for invasion and metastasis of cancer cells.

Significance of lymph node metastasis in cancer dissemination of head and neck cancer

Lymph node metastasis (LNM) in many solid cancers is a well-known prognostic factor; however, it has been debated whether regional LNM simply reflects tumor aggressiveness or is a source for further tumor dissemination. Similarly, the metastatic process in head and neck cancer (HNC) has not been fully evaluated. Thus, we aimed to investigate the relative significance of LNM in metastatic cascade of HNC using functional imaging of HNC patients and molecular imaging in in vivo models. First, we analyzed ¹⁸Fluorodeoxyglucose positron emission tomography (PET) parameters of 117 patients with oral cancer. The primary tumor and nodal PET parameters were measured separately, and survival analyses were conducted on the basis of clinical and PET variables to identify significant prognostic factors. In multivariate analyses, we found that only the metastatic node PET values were significant. Next, we compared the relative frequency of lung metastasis in primary ear tumors versus lymph node (LN) tumors, and we tested the rate of lung metastasis in another animal model, in which each animal had both primary and LN tumors that were expressing different colors. As a result, LN tumors showed higher frequencies of lung metastasis compared to orthotopic primary tumors. In color-matched comparisons, the relative contribution to lung metastasis was higher in LN tumors than in primary tumors, although both primary and LN tumors caused lung metastases. In summary, tumors growing in the LN microenvironment spread to systemic sites more commonly than primary tumors in HNC, suggesting that the adequate management of LNM can reduce further systemic metastasis.

HMGA2 is associated with epithelial-mesenchymal transition and can predict poor prognosis in nasopharyngeal carcinoma

Objective

High-mobility group protein 2 (HMGA2) and epithelial–mesenchymal transition (EMT)-associated proteins play key roles in cancer progression and metastasis. However, the clinical significance of HMGA2 and its relationship with EMT markers in nasopharyngeal carcinoma (NPC) is unclear. This study aimed to assess the clinicopathological significance and prognostic value of HMGA2, E-cadherin, and vimentin in NPC.

Methods

Using immunohistochemistry, HMGA2, E-cadherin, and vimentin expression levels were evaluated in NPC (n=124) and non-tumoral inflammatory nasopharynx (n=20) tissues. The association of HMGA2 and EMT markers with clinicopathological characteristics and relationships between the protein levels and overall survival were analyzed.

Results

Compared with non-tumorous tissues, HMGA2 and vimentin levels were markedly increased in NPC tissues, whereas decreased E-cadherin levels were observed (P<0.001). Moreover, HMGA2 expression was positively correlated with vimentin levels (r=0.431, P<0.001) and negatively correlated with E-cadherin amounts (r=−0.413, P<0.001) in NPC tissues. The expression of all three proteins correlated significantly with tumor N stage, TNM stage, and 2-year metastasis. Furthermore, significant correlations were found for T stage, N stage, TNM stage, HMGA2, E-cadherin, and vimentin (all P<0.013) with poor prognosis (univariate analysis). However, multivariate analyses showed that only HMGA2 (hazard ratio [HR]: 2.683, 95% confidence interval [CI]: 1.185–6.077, P=0.018) and N stage (HR: 7.892, 95% CI: 2.731–22.807, P<0.001) were independent predictors of poor prognosis.

Conclusion

These results demonstrated that HMGA2, an independent prognostic factor, may promote NPC progression and metastasis, and is significantly associated with EMT proteins. Therefore, HMGA2 may be considered a potential therapeutic target in NPC.