Metastatic Oral Squamous Cell Carcinoma Research Articles

English

Intervention to the evolution and metastasis of oral squamous cell carcinoma (OSCC) from oral leukoplakia (OLK) out of normal mucosa is currently far from ultimate. New technologies and insights are reckoned on for etiology and clinical protocol of OSCC and mucosa lesions. SELDI-TOF-MS technology, Support vector machine, Discriminate Analysis, and CM10 protein chip were applied to study the sera proteomes of 32 healthy volunteers, 6 patients with oral mucosa leukoplakia, 28 OSCC patients, and 8 patients with metastatic OSCC. Ratios of protein mass to its charge (m/z) showed in valve peak value were delivered and discriminated out of the huge amount of protein data as group markers for identifications. Protein peak values 4181 and 4651 were high in volunteers serum while low in patients with OLK, the sensitivity of which was 100.00% (32/32), specificity was 83.33%(5/6), accuracy was 97.37%(37/38). And m/z 4162, 6886 of 87.82, 92.86 and 66.67%; 4289, 5661, 6195, 4352, 5072 of 97.22, 100.00 and 87.5% were discriminates between OLK and local OSCC, between local OSCC and regionally metastatic OSCC, respectively. Conclusively, researches are encouraged to launch a proteomics assistance and guidance in modern molecular diagnostic approaches for understanding and controlling the mucosa lesions especially in conquering the malignant progress. Keywords: Oral squamous cell carcinoma (OSCC); oral leukoplakia (OLK), ZUCI-PDAS (Zhejiang University Cancer Institute ProteinChip Data Analysis System), bioinformatics technology, discriminate analysis, proteomes of optimization African Journal of Biotechnology , Vol 13(19), 2084-2089

Podocalyxin-like 1 is associated with tumor aggressiveness and metastatic gene expression in human oral squamous cell carcinoma

Metastasis-mediated death remains a major challenge in cancer treatment due to the lack of identifiable biomarkers for early diagnosis. Identifying tumor-specific biomarkers is critical for the development of diagnostic and therapeutic tools. In the present study, we found that podocalyxin-like 1 (PODXL), a cell surface glycoprotein, was overexpressed in cancer tissues and was upregulated in lymph node metastatic tumor cells. The expression of PODXL was associated with the migratory ability of human oral squamous cell carcinoma (OSCC). Knockdown of PODXL by small hairpin RNA in the SAS OSCC cell line reduced tumor migration and invasion, and inhibited cell proliferation and colony formation. Suppression of PODXL resulted in downregulation of focal adhesion kinase (FAK) and paxillin phosphorylation. PODXL silencing inhibited filopodia formation, and suppressed F-actin and cortactin colocalization. In addition, PODXL expression was associated with the DNA methylation status, and treatment with the DNA methyltransferase inhibitor 5-aza-deoxycytidine increased the PODXL transcriptional level. Moreover, DNA microarray analysis data revealed that suppression of PODXL significantly affected subsets of genes associated with extracellular matrix organization, the epithelial-mesenchymal transition, and the expression of metastasis-related cytokines. Collectively, these data showed that the overexpression of PODXL may be associated with tumor aggressiveness and that PODXL could be a diagnostic biomarker for metastatic OSCC.

Oct4 Mediates Tumor Initiating Properties in Oral Squamous Cell Carcinomas through the Regulation of Epithelial-Mesenchymal Transition

BackgroundOverexpression of Oct4, an important transcription factor of embryonic stem cells (ESC), has been reported in several cancers. The aim of this study was to determine the emerging role of Oct4 in oral squamous cell carcinoma (OSCC) both in vitro and in vivo.Methodology/Principal FindingTumourigenic activity and molecular mechanisms of Oct4 overexpression or knockdown by lentiviral infection in OSCC was investigated in vitro and in vivo. Initially, we demonstrated that Oct4 expression was increased in OSCC cell lines as compared to a normal oral epithelial cell line SG. Overexpression of Oct4 was demonstrated to enhance cell proliferation, invasiveness, anchorage-independent growth and xenotransplantation tumourigenicity. These findings were coupled with epithelial-mesenchymal transition (EMT) transformation in OSCCs. In contrast, the silence of Oct4 significantly blocked the xenograft tumorigenesis of OSCC-derived cancer stem cells (OSCC-CSCs) and significantly improved the recipient survival. Clinically, the level of Oct4 expression was higher in recurrent and metastatic OSCC specimens but lower in primary OSCC specimens.Conclusion/SignificanceOur results suggest that Oct4-mediated tumorigenecity is associated with the regulation of EMT. Oct4 might be a therapeutic target for OSCC.

The tumour microenvironment in oral squamous cell carcinoma

Background The aim of this project was to look at aspects of the tumour micro-environment in oral squamous cell carcinoma (OSCC). Methods Immune-associated gene expression was assessed using focused array technology and real-time polymerase chain reaction. Single and doubled labelled immunohistochemistry and immunofluorescence techniques were used to determine protein expression. Fresh and formalin-fixed paraffin embedded samples of OSCC tissue, lymph nodes containing metastatic OSCC and normal oral mucosa were studied. Results Increased numbers of toll-like receptor (TLR)2 + keratinocytes were seen within the OSCC microenvironment compared with control epithelium. Other cells expressing TLR2 in the tumour microenvironment were large and morphologically consistent with macrophages or dendritic cells. The presence of TLR2 + FoxP3 + regulatory T cells were also found within the OSCC immune cell infiltrate. Gene expression analysis demonstrated that OSCCs and metastatic lymph nodes showed increased expression of genes associated with T cell anergy. Conclusions The results of the present study have shown increased numbers of TLR2 + cells in OSCC which could potentially be modulated to shift the environment towards a Thl environment thus stimulating the pro-inflammatory process. At the same time T cell anergy might contribute to the molecular ability of OSCC to progress and metastasise to secondary lymphoid organs

TWIST1 is a molecular marker for a poor prognosis in oral cancer and represents a potential therapeutic target

Locoregional recurrence and distant metastases are ominous events in patients with advanced oral squamous cell carcinoma (OSCC). The objective of this study was to identify functional biomarkers that are predictive of OSCC progression to metastasis. The expression profile of a network of epithelial-mesenchymal transition (EMT) genes was investigated in a large cohort of patients with progressive OSCC using a complimentary DNA microarray platform coupled to quantitative reverse transcriptase-polymerase chain reaction and immunohistochemical analyses. Therapeutic potential was investigated in vitro and in vivo using an orthotopic mouse model of metastatic OSCC growing in the tongue microenvironment. Among deregulated EMT genes, the Twist-related protein 1 (TWIST1) transcription factor and several of its regulated genes were significantly overexpressed across advanced stages of OSCC. This result was corroborated by the clinical observation that Twist1 up-regulation predicted the occurrence of lymph node and lung metastases as well as poor patient survival. In support of Twist1 as a driver of OSCC progression, the up-regulation of Twist1 was observed in cells isolated from patients with metastatic OSCC. The inhibition of Twist1 in these metastatic cells induced a potent inhibition of cell invasiveness in vitro as well as progression in vivo. The current results provide evidence for the prognostic value and therapeutic potential of a network of Twist genes in patients with advanced OSCC.

PP077: Twist1 and its genes’ network are molecular signature for prediction of oral cancer progression and represent potential therapeutic targets

Loco-regional recurrence and distant metastases are ominous events in patients with advanced oral squamous cell carcinomas (OSCC). In this study we investigated the expression profile of Epithelial–Mesenchymal-Transition (EMT) genes’ network in a large cohort of patients with invasive OSCC. Altered gene expression profiles were analyzed using a cDNA microarray platform coupled to qRT-PCR and immunohistochemical analysis in metastasized and non-metastasized tumors. We identified TWIST1 transcription factor to be consistently overexpressed in advanced stages of OSCC and to predict lymph node and lung metastases, as well as poor patients’ survival. Moreover, we identified concomitant changes in the expression of several Twist-regulated genes across advanced stages of OSCC cohorts; these include reduced or loss of CDH1 and upregulation of VEGFA . In support of Twist1 being an important biomarker for OSCC progression, we demonstrated that the inhibition of TWIST1 in cancer cells established from human metastatic OSCC induces a potent inhibition of cell invasive phenotype in vitro as well as tumor progression when implanted in mice. Together, these results provide evidence for the prognostic value of Twist genes’ network and pinpoints to the therapeutic potential of targeting this transcription factor to interfere with OSCC progression.

Abstract 5129: AGR2 is a potential marker for metastatic human oral squamous cell carcinoma.

Abstract Purpose: The mortality of oral cancer, which is a common subtype of human and neck squamous cell carcinomas (HNSCC), is increasing in Taiwan, Southeast Asia, and eastern countries during the last twenty years. Averagely, the 5-year survival rate of distant metastasis of oral carcinoma is less than 30-40%. Prevention of cancer metastasis to distant organs is one of practical approaches that may reduce the mortality of patients. This study aims to identify novel metastatic tumor markers for oral cancer. Experimental Design and Results: A high metastatic sub-population, HSC-3-5 cells, was divided from human oral cancer HSC-3 by Transwell invasion assay. Our results indicated that HSC-3-5 cells exhibited higher metastatic capacities due to re-arrangement cytoskeleton and subsequently epithelial mesenchymal transition transformation in vitro. In addition, metastatic and tumorigenetic capacities of HSC-3-5 cells were characterized by spontaneous and experimental metastasis experiments in vivo. The microarray-based gene expression profiles of HSC-3/HSC-3-5 cells and their corresponded xenografts (orthotropic and heterotopic) were then performed. Anterior gradient 2 (AGR2), a pro-oncogenic signaling intermediate in various human cancers, was the most significantly up-regulated gene in HSC-3-5 cells compared with HSC-3. Furthermore, overexpression of AGR2 protein was verified in cells, xenograft animal models, and clinical patient tissues, and it encompassed positive relation with OSCC metastasis. Conclusions: A high metastatic sub-population HSC-3-5 cell line derived from human oral cancer HSC-3 cells was divided. HSC-3-5 cells represented higher capacities not only in metastasis but also in tumorigenesis. According to microarray gene profiles and immunohistochemistry analysis, the expression of identified potential biomarker, AGR2, showed positive relationship with tumor metastasis during oral carcinogenesis. Citation Format: Yi-Ting Chen, Chung-Liang Ho, Po-Ku Chen, Yuh-Ling Chen, Chung-Fa Chang. AGR2 is a potential marker for metastatic human oral squamous cell carcinoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5129. doi:10.1158/1538-7445.AM2013-5129

Frequency of Fibroblast Growth Factor Receptor 1 gene amplification in oral tongue squamous cell carcinomas and associations with clinical features and patient outcome

Novel therapies are required for patients with recurrent or metastatic oral tongue squamous cell carcinoma (OTSCC). Fibroblast Growth Factor Receptor 1 (FGFR1) amplification frequently occurs in squamous cell carcinoma of the lung and represents a novel druggable therapeutic target in this and other malignancies. This study examined the frequency and clinical associations of FGFR1 amplification in OTSCC. The frequency of FGFR1 amplification determined by fluorescence in situ hybridization was evaluated in a cohort of 123 OTSCC patients. Associations of FGFR1 amplification with clinical characteristics and outcome were determined. FGFR1 gene amplification was present in 9.3% (10/107) of cases and was significantly associated with smoking status (P = 0.03). FGFR1 amplification was seen more commonly in males (9/10 amplified cases male, P = 0.16) and there were no associations with age, stage, T stage, nodal status, alcohol history or performance status (all P>0.05). Outcome was not significantly different between FGFR1 amplified and non-amplified patients. Copy number variations of the FGFR1 gene occur in a subset of OTSCC with approximately 10% of cases showing amplification of the gene. FGFR1 amplification may represent a therapeutic target in OTSCC.

Genomic Profiling of Oral Squamous Cell Carcinoma by Array-Based Comparative Genomic Hybridization

We designed a study to investigate genetic relationships between primary tumors of oral squamous cell carcinoma (OSCC) and their lymph node metastases, and to identify genomic copy number aberrations (CNAs) related to lymph node metastasis. For this purpose, we collected a total of 42 tumor samples from 25 patients and analyzed their genomic profiles by array-based comparative genomic hybridization. We then compared the genetic profiles of metastatic primary tumors (MPTs) with their paired lymph node metastases (LNMs), and also those of LNMs with non-metastatic primary tumors (NMPTs). Firstly, we found that although there were some distinctive differences in the patterns of genomic profiles between MPTs and their paired LNMs, the paired samples shared similar genomic aberration patterns in each case. Unsupervised hierarchical clustering analysis grouped together 12 of the 15 MPT-LNM pairs. Furthermore, similarity scores between paired samples were significantly higher than those between non-paired samples. These results suggested that MPTs and their paired LNMs are composed predominantly of genetically clonal tumor cells, while minor populations with different CNAs may also exist in metastatic OSCCs. Secondly, to identify CNAs related to lymph node metastasis, we compared CNAs between grouped samples of MPTs and LNMs, but were unable to find any CNAs that were more common in LNMs. Finally, we hypothesized that subpopulations carrying metastasis-related CNAs might be present in both the MPT and LNM. Accordingly, we compared CNAs between NMPTs and LNMs, and found that gains of 7p, 8q and 17q were more common in the latter than in the former, suggesting that these CNAs may be involved in lymph node metastasis of OSCC. In conclusion, our data suggest that in OSCCs showing metastasis, the primary and metastatic tumors share similar genomic profiles, and that cells in the primary tumor may tend to metastasize after acquiring metastasis-associated CNAs.

Integrative Genomics in Combination with RNA Interference Identifies Prognostic and Functionally Relevant Gene Targets for Oral Squamous Cell Carcinoma

In oral squamous cell carcinoma (OSCC), metastasis to lymph nodes is associated with a 50% reduction in 5-year survival. To identify a metastatic gene set based on DNA copy number abnormalities (CNAs) of differentially expressed genes, we compared DNA and RNA of OSCC cells laser-microdissected from non-metastatic primary tumors (n = 17) with those from lymph node metastases (n = 20), using Affymetrix 250K Nsp single-nucleotide polymorphism (SNP) arrays and U133 Plus 2.0 arrays, respectively. With a false discovery rate (FDR)<5%, 1988 transcripts were found to be differentially expressed between primary and metastatic OSCC. Of these, 114 were found to have a significant correlation between DNA copy number and gene expression (FDR<0.01). Among these 114 correlated transcripts, the corresponding genomic regions of each of 95 transcripts had CNAs differences between primary and metastatic OSCC (FDR<0.01). Using an independent dataset of 133 patients, multivariable analysis showed that the OSCC–specific and overall mortality hazards ratio (HR) for patients carrying the 95-transcript signature were 4.75 (95% CI: 2.03–11.11) and 3.45 (95% CI: 1.84–6.50), respectively. To determine the degree by which these genes impact cell survival, we compared the growth of five OSCC cell lines before and after knockdown of over-amplified transcripts via a high-throughput siRNA–mediated screen. The expression-knockdown of 18 of the 26 genes tested showed a growth suppression ≥30% in at least one cell line (P<0.01). In particular, cell lines derived from late-stage OSCC were more sensitive to the knockdown of G3BP1 than cell lines derived from early-stage OSCC, and the growth suppression was likely caused by increase in apoptosis. Further investigation is warranted to examine the biological role of these genes in OSCC progression and their therapeutic potentials.

Immunohistochemical expression of endothelin protein in oral squamous cell carcinoma

Endothelin-1 (ET-1) plays a significant role in cancer biology and is considered as a potential target for molecular therapy. Alteration of ET-1 was detected in oral squamous cell carcinoma (OSCC). To evaluate the immunohistochemical expression and distribution of ET-1 in OSCC and to correlate its expression with the degree of histopathologic differentiation as well as the regional metastatic status of OSCC. The immunohistochemical expression and distribution of ET-1 was evaluated in total number of 30 cases of OSCC. The specimens were retrieved as formalin-fixed, paraffin-embedded blocks from the archival files. Detection of ET-1 expression in different grades of metastatic and non-metastatic OSCC was quantified using an image analyzer computer system. Statistical software package SPSS v. 19. ET-1 immunoreactivity was observed in all studied specimens. On comparing optical density values for ET-1 expression in different grades of OSCC, poorly differentiated OSCC showed a significantly greater expression than moderately differentiated OSCC, which was also significantly greater than well-differentiated OSCC ( P = 0.001). Moreover, ET-1 expression was higher in metastatic OSCC than that in non-metastatic OSCC ( P = 0.018). Increased ET-1 expression could enhance the aggressive behavior of poorly differentiated OSCC, especially metastasis. Accordingly, ET-1 could be a therapeutic target in OSCC.

Stromal myofibroblasts in nonmetastatic and metastatic oral squamous cell carcinoma: An immunohistochemical study

Background and Aims:Myofibroblasts are one of the important components of the tumor microenvironment which could possibly play an important role in tumor progression. The purpose of this study was to compare the presence of α-smooth muscle actin (α-SMA) and CD34 positive fibroblasts in nonmetastatic and metastatic oral squamous cell carcinoma and to evaluate their role in tumor metastasis.Materials and Methods:Ten cases each of histologically proven metastatic and nonmetastatic oral squamous cell carcinoma formed the study group. The tissue sections were stained immunohistochemically for α-SMA and CD34. The stromal spindle cells positive for these markers in the study groups were counted and compared.Results:α-SMA positive cases were more in the metastatic group and CD34 positive cases were found to be more in the nonmetastatic tumors.Conclusions:Though difference in the staining pattern was statistically nonsignificant, the inverse relationship between α-SMA and CD34 positive cells is indicative of dynamic nature and the influence of tumor stroma in tumor progression and metastasis.

Silencing of Atp6v1c1 Prevents Breast Cancer Growth and Bone Metastasis

Previous studies have shown that Atp6v1c1, a regulator of the assembly of the V0 and V1 domains of the V-ATPase complex, is up-regulated in metastatic oral tumors. Despite these studies, the function of Atp6v1c1 in tumor growth and metastasis is still unknown. Atp6v1c1's expression in metastatic oral squamous cell carcinoma indicates that Atp6v1c1 has an important function in cancer growth and metastasis. We hypothesized that elevated expression of Atp6v1c1 is essential to cancer growth and metastasis and that Atp6v1c1 promotes cancer growth and metastasis through activation of V-ATPase activity. To test this hypothesis, a Lentivirus-mediated RNAi knockdown approach was used to study the function of Atp6v1c1 in mouse 4T1 mammary tumor cell proliferation and migration in vitro and cancer growth and metastasis in vivo. Our data revealed that silencing of Atp6v1c1 in 4T1 cancer cells inhibited lysosomal acidification and severely impaired 4T1 cell growth, migration, and invasion through Matrigel in vitro. We also show that Atp6v1c1 knockdown with Lenti-c1s3, a lentivirus targeting Atp6v1c1 for shRNA mediated knockdown, can significantly inhibit 4T1 xenograft tumor growth, metastasis, and osteolytic lesions in vivo. Our study demonstrates that Atp6v1c1 may promote breast cancer growth and bone metastasis through regulation of lysosomal V-ATPase activity, indicating that Atp6v1c1 may be a viable target for breast cancer therapy and silencing of Atp6v1c1 may be an innovative therapeutic approach for the treatment and prevention of breast cancer growth and metastasis.

STAT3 signal transduction through interleukin-22 in oral squamous cell carcinoma

Interleukin (IL)-22 is a member of the IL-10 family. Its main targets are epithelial cells, not immune cells. We examined IL-22 signal transduction in oral squamous cell carcinoma (OSCC) cells. Immunohistochemical staining revealed that IL-22R was expressed more highly in OSCC compared to normal regions. An IL-22R signal was also observed in metastatic OSCC cells in the lymph node. RT-PCR showed that the human OSCC cell lines MISK81-5, HSC-3, HSC-4, SAS and SQUU-B expressed IL-22 receptor chains. Immunoblotting showed that IL-22 induced a transient tyrosine phosphorylation of STAT3 (pY705-STAT3) in MISK81-5 cells. The change in the serine phosphorylation of STAT3 was subtle during the examination periods. Simultaneously, pY705-STAT3 activation in HSC-3 cells was undetectable after IL-22 stimulation. Immunocytochemistry demonstrated that IL-22 induced the translocation of phosphorylated STAT3 into the nucleus of MISK81-5 cells. IL-22 temporarily upregulated the expression of anti-apoptotic and mitogenic genes such as Bcl-x, survivin and c-Myc, as well as SOCS3. IL-22 transiently activated ERK1/2 and induced a delayed phosphorylation of p38 MAP kinase, but negligibly involved the activation of NF-κB in MISK81-5 cells. MISK81-5 and SQUU-B cells treated with IL-22 showed mild cellular proliferation. MISK81-5, HSC-4 and SAS cells treated with IL-22 downregulated the keratinocyte differentiation-related genes compared with unstimulated cells. Conversely, STAT3 suppression by STAT3 siRNA strongly disrupted the down-regulation of these genes by IL-22, but it did not significantly affect the activation of ERK1/2 by IL-22. The OSCC cells used in this study upregulated the expression of SERPINB3/4 (SCCA1/2), well-known SCC markers, following treatment with IL-22. These results indicate that IL-22 differentially activates the STAT3 signaling system depending on the type of OSCC. IL-22 may therefore play a role in tumor growth, cell differentiation and progression through STAT3-dependent and -independent pathways.

Functional invadopodia formation through stabilization of the PDPN transcript by IMP-3 and cancer-stromal crosstalk for PDPN expression

We previously reported that insulin-like growth factor-II mRNA-binding protein-3 (IMP-3) depletion (IMP-3(Δ)) was shown to inhibit invadopodia formation and extracellular matrix degradation capacity in oral squamous cell carcinoma (OSCC) cells. In this study, we found that IMP-3(Δ) cells significantly downregulated the podoplanin (PDPN) level, which resulted in a loss of extracellular matrix degradation activity, although invadopodia was still thriving. From RNA in situ hybridization using a digoxigenin-labeled 3'UTR recognition probe of PDPN and reporter assay with 3'UTR of the PDPN gene cloned downstream from the luciferase reporter gene, we revealed that IMP-3 depletion was shown to be downregulated, which most probably lowered PDPN gene expression by reducing mRNA stabilization. In a xenograft model, PDPN depletion was the cause of a decrease in tumor volume and regional infiltration into nearby stroma. Taken together, transforming growth factor beta 1 increased PDPN expression, which potentiated cancer invasion through increased invadopodia formation and extracellular matrix degradation in the low invasive OSCC cell line. Reciprocally, interleukin-1 beta secreted by OSCC cells, stimulated transforming growth factor beta 1 secretion from stromal fibroblasts to induce PDPN expression in OSCC cells. In addition, a retrospective investigation of OSCC patients found that IMP-3 and PDPN expression significantly correlated with lymph node metastasis of OSCC patients. Moreover, co-expression of IMP-3 and PDPN were frequently detected both in primary and lymph nodes metastatic OSCC cells using immunohistochemical dual staining. Thus, the IMP-3-PDPN axis may be a sensitive target molecule in anti-invadopodia therapy for the treatment of metastatic cancers.

Can Quantifying Free-Circulating DNA Be a Diagnostic and Prognostic Marker in Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma?

Previous studies have reported significantly higher concentrations of serum DNA in various types of cancers. Thus the study aims to determine whether circulating free DNA (CFDNA) can aid in the diagnosis and prognosis of oral epithelial dysplasia and oral squamous cell carcinoma (OSCC). A nonrandomized case-control study was planned where cases were derived from patients who presented to the KLE Institute of Dental Sciences, Belgaum, India, for evaluation and management of oral lesions between 2007 and 2009. In this study the predictor variable was status of the disease in the patients, and the outcome variable was CFDNA. Demographic variables included age, gender, tobacco consumption, and stage at diagnosis of cancer. Subjects with any known systemic disease, other tumors, or metastatic OSCC were excluded (CFDNA is altered in cases of tissue destruction and inflammatory diseases). The amount of CFDNA was determined through spectrophotometry (NanoDrop ND-1000 spectrophotometer; Thermo Fisher Scientific, Waltham, MA) in sampled blood and plasma. Mean and range for DNA quantification in plasma and blood were calculated in all groups and compared by use of the analysis of variance test. A total of 390 cases (90 potentially malignant lesions, 150 OSCC cases, and 150 post-treatment OSCC cases) and 150 control subjects were studied. No significant difference was observed in levels of CFDNA in blood between the groups. Similarly, levels of CFDNA in plasma showed no significant difference except between the OSCC and potentially malignant groups, which was probably artifactual. This study shows that disease progression in oral malignancy does not correlate with changes in levels of CFDNA in blood or plasma.

Sentinel lymph node biopsy versus selective neck dissection for detection of metastatic oral squamous cell carcinoma

Metastasis to the regional lymph node is the most important prognostic indicator for the outcomes of patients with sold cancer. In general, it is well recognized that cancer development is genetically determined with progression from the microenvironment of the primary tumor site, oftentimes via the SLN gateway, to the distant sites. In about 20 % of the time, the cancer cells may spread directly through the blood vascular system to the distant sites. Thus, in general, cancer progression is consistent with Hellman's spectrum theory in that development of nodal and systemic metastasis from a localized cancer growth is a progressive process. Cancer proliferation within the tumor microenvironment may give rise to increased tumor heterogeneity, which is further complicated by its continuous change through its evolution within the host in a Darwinian sense. It is crucial to understand the molecular process of lymphangiogenesis and hemangiogenesis in the tumor microenvironment with respect to the initial steps of cancer cells entering into the lymphatic and vascular systems so that rational therapy can be developed to curb the process of specific routes of metastasis. This chapter elucidates the role of lymphatics, nodal metastasis and antitumor immunity. We present novel immune targets in nodal metastases, the importance of the lymph node as a pre-metastatic niche, and immune-related proteins as biomarkers of metastasis.

Integrative analysis in oral squamous cell carcinoma reveals DNA copy number-associated miRNAs dysregulating target genes.

To better understand possible mechanisms involved in the dysregulation of gene expression unique to oral squamous cell carcinoma (OSCC) metastasis, the investigators examined the differential expression of microRNAs (miRNAs) in OSCC metastasis and their functional impact on target gene expression. Observational assessment of DNA copy number, miRNA, and RNA expression in primary and metastatic OSCC. University of Washington Medical Center and affiliated hospitals. Tumor samples were taken from patients with primary incident OSCC; cells were laser-capture microdissected from 17 nonmetastatic primary tumors and 20 metastatic lymph nodes. DNA copy number aberrations and gene expression profiles were previously determined using Affymetrix 250K Nsp I SNP arrays and HU133 plus 2.0 expression arrays. miRNAs were interrogated with Exiqon's Ready-to-Use PCR Panels assessing the expression of 368 human miRNAs. Investigators found 31 miRNAs differentially expressed between metastatic and nonmetastatic samples (false discovery rate <0.4; 26 overexpressed and 5 underexpressed in metastatic samples). Expression of 7 of these miRNAs was significantly associated with their DNA copy numbers, and expressions of 8 of these miRNAs were significantly associated with their target genes. Among these unique miRNAs, miR-140-3p, miR-29c, and miR-29a were differentially expressed in metastasis versus nonmetastatic samples and had a strong positive correlation with their DNA copy numbers and a negative correlation with the expression of their target genes. Results suggest that DNA copy number aberration may play a role in the dysregulation of some differentially expressed miRNAs in OSCC metastasis, warranting further investigation.

Premetastatic vasculogenesis in oral squamous cell carcinoma xenograft-draining lymph nodes

To study vascular anatomy on oral cancer-draining lymph nodes before metastasis in mice. Cell lines: highly lymph metastatic oral squamous cell carcinoma SASL1m and non-metastatic human adenoid cystic carcinoma ACC2. Bone marrow transplants and xenografts: Nude mice were lethally irradiated and transplanted with bone marrow cells from EGFP(+) mice. SASL1m or ACC2 cells were implanted in the tongue. Non-xenografted mice were used as controls. In addition, we injected conditioned medium from SASL1m or ACC2 in transplanted mice. Immunohistochemistry: Primary tumors and neck lymph nodes were resected and stained with anti-mouse Podoplanin and CD31. Images were visualized in a confocal microscope. Image analysis: Areas covered by EGFP, CD31 and Podoplanin were measured and compared statistically. Expression microarrays: Transcriptomic microarray analysis compared SASL1 to ACC2 cells. Interactomes were generated to reveal altered pathways. SASL1m cells induced the assemblage of blood vessels in cancer-free, tumor-draining lymph nodes. These blood vessels incorporated bone marrow-derived EGFP(+)CD31(+) cells. Notably, SASL1m-conditioned medium induced a similar reaction. Non-metastatic cells failed to produce any change. Microarray and pathway analyses revealed the upregulation of Transforming Growth Factor-β, Lysyl Oxidase-like 2, Slit homolog 3 and Protease Serine 22. The upregulation of these genes was confirmed in xenografts. This study suggests that a blood supply for new tumors is established in lymph nodes before metastasis. It also suggests that premetastatic vasculogenesis and primary tumor angiogenesis may be mediated by different mechanisms.

Selective inhibition of nuclear factor‐κB by nuclear factor‐κB essential modulator‐binding domain peptide suppresses the metastasis of highly metastatic oral squamous cell carcinoma

Nuclear factor-κB (NF-κB) activation contributes to the development of metastasis, thus leading to a poor prognosis in many cancers, including OSCC. However, little in vivo experimental data are available about the effects of NF-κB inhibition on OSCC metastasis. OSCC sublines were established from a GFP-expressing parental cell line, GSAS, and designated GSAS/N3 and N5 according to the in vivo passage number after cervical lymph node metastasis by a serial orthotopic transplantation model. In vitro migration and invasion were assessed in these cells, and the NF-κB activities and expression of NF-κB-regulated metastasis-related molecules were also examined. In in vivo experiments, the metastasis and survival of tumor-engrafted mice were monitored. Furthermore, the effects of a selective NF-κB inhibitor, NEMO-binding domain (NBD) peptide, on metastasis in GSAS/N5-engrafted mice were assessed, and engrafted tongue tumors were immunohistochemically examined. Highly metastatic GSAS/N3 and N5 cells showed an enhanced NF-κB activity, thus contributing to increased migration, invasion, and a poor prognosis compared with the parent cells. Furthermore, the expression levels of NF-κB-regulated metastasis-related molecules, such as fibronectin, β1 integrin, MMP-1, -2, -9, and -14, and VEGF-C, were upregulated in the highly metastatic cells. The NBD peptide suppressed metastasis and tongue tumor growth in GSAS/N5-inoculated mice, and was accompanied by the downregulation of the NF-κB-regulated metastasis-related molecules in engrafted tongue tumors. Our results suggest that the selective inhibition of NF-κB activation by NBD peptide may provide an effective approach for the treatment of highly metastatic OSCC.