Overexpression of suppressor of zest 12 is associated with cervical node metastasis and unfavorable prognosis in tongue squamous cell carcinoma

Molecular landscape of proliferative verrucous leukoplakia: a systematic review

Proliferative verrucous leukoplakia (PVL) is a rare oral potentially malignant disorder characterised by multifocal origin and unpredictable long-term evolution to oral squamous cell carcinoma (OSCC) or oral verrucous carcinoma (OVC). Currently no predictive biomarkers are in clinical use. We aimed to explore the genomic profile of PVL. A total of 685 cases in 26 studies were included in this review. Genomic data were presented in 15% of studies and biomarker analysis was reported in 85% of studies. At first clinical presentation, PVL is characterised by a high loss of heterozygosity (LOH), similar to OSCC, and low copy number alterations (CNA). As these progress, more CNAs and mutations in CDKN2A and alterations to ELAVL1 expression are noted, but no TP53 mutations are identified. There is significantly lower LOH at 17p in early PVL compared with OSCC (p = 0.037). Deletions in chromosomal loci 17q12, 5q31.1 and amplifications in 7q11.2, 7q22 are shared between early lesions and OVC. PVL shows CNAs at 11q31. WNT signalling pathway genes (SUZ12, CTTN and FOLR3) are enriched in CN-altered regions. PVL stroma shows significantly lower α-SMA and higher CD34 expression than OVC and OSCC. The exact genomic landscape is currently unclear, and further studies are necessary to unravel this mystery.

Evaluation of tumor-infiltrating T & B lymphocytes and their association and distribution in oral squamous cell carcinoma tumor microenvironment: An in vitro immunohistochemical study

OBJECTIVE

The immune interaction between host immunity and the tumor microenvironment is complex, and a thorough understanding of tumor-infiltrating lymphocyte selection in oral cancer, including T and B cells, is urgently required. Within the tumor microenvironment, tumor cells escape immune surveillance and grow uncontrollably. The study examined the relationship and distribution of tumor-infiltrating T and B lymphocytes.

STUDY DESIGN

Retrospective data of paraffin-embedded tissue samples of 47 primary oral squamous cell carcinoma (OSCC) cases were retrieved. Hematoxylin and eosin evaluation, along with all clinicopathologic data, were collected. Immunohistochemical CD3 and CD20 markers were used and evaluated for association and distribution in given OSCC cases.

RESULTS

The intermediate type of inflammatory infiltrate was seen primarily in Well DIfferentiated Squamous cell Carcinoma grade and positive and negative lymph nodes. Compared with T-cell density, B-cell density showed an aggregate pattern rather than a scattered pattern, indicating a statistically significant association between T-cell and B-cell infiltrate. B-cell infiltrates were also found to have a statistically significant relationship with tertiary lymphoid structure.

CONCLUSIONS

A strong, positive association and correlation exists between B- and T-lymphocyte infiltration in both the stroma and the invasive front. When compared with T-cell density, B-cell density is more predominantly in aggregates.

Long Non-coding RNA DANCR in Cancer: Roles, Mechanisms, and Implications

Long non-coding RNA (lncRNA) DANCR (also known as ANCR)—differentiation antagonizing non-protein coding RNA, was first reported in 2012 to suppress differentiation of epithelial cells. Emerging evidence demonstrates that DANCR is a cancer-associated lncRNA abnormally expressed in many cancers (e.g., lung cancer, gastric cancer, breast cancer, hepatocellular carcinoma). Increasing studies suggest that the dysregulation of DANCR plays critical roles in cancer cell proliferation, apoptosis, migration, invasion, and chemoresistance in vitro and tumor growth and metastasis in vivo. Mechanistic analyses show that DANCR can serve as miRNA sponges, stabilize mRNAs, and interact with proteins. Recent research reveals that DANCR can be detected in many body fluids such as serum, plasma, and exosomes, providing a quick and convenient method for cancer monitor. Thus DANCR can be used as a promising diagnostic and prognostic biomarker and therapeutic target for various types of cancer. This review focuses on the role and mechanism of DANCR in cancer progression with an emphasis on the clinical significance of DANCR in human cancers.

ER-/PR+ breast cancer: A distinct entity, which is morphologically and molecularly close to triple-negative breast cancer

Determining the status of steroid hormone receptors [oestrogen (ER) and progesterone receptors (PR)] is a crucial part of the breast cancer workup. Thereby, breast cancers can be classified into four subtypes. However, the existence of ER-/PR+ tumours, often reported to be ill-classified due to technical errors, remains controversial. In order to address this controversy, we reviewed the hormone receptor status of 49 breast tumours previously classified as ER-/PR+ by immunohistochemistry, and compared clinical, pathological and molecular characteristics of confirmed ER-/PR+ tumours with those of ER+ and triple-negative tumours. We unequivocally confirmed the ER-/PR+ status in 27 of 49 tumours (0.3% of all breast cancers diagnosed in our institution between 2000 and 2014). We found that ER-/PR+ were morphologically and histologically similar to triple-negative tumours, but very distinct from ER+ tumours, with more aggressive phenotypes and more frequent basal marker expression than the latter. On the molecular level, RNA sequencing revealed different gene expression profiles between the three groups. Of particular interest, several genes controlled by the suppressor of zest 12 (SUZ12) were upregulated in ER-/PR+ tumours. Overall, our results confirm that ER-/PR+ breast cancers are an extremely rare but 'real' tumour subtype that requires careful diagnosis and has distinct features warranting different responsiveness to therapies and different clinical outcomes. Studies on larger cohorts are needed to further characterise these tumours. The likely involvement of SUZ12 in their biology is an interesting finding which may - in a long run - give rise to the development of new therapeutic alternatives.

Efficient weighted univariate clustering maps outstanding dysregulated genomic zones in human cancers

Motivation

Chromosomal patterning of gene expression in cancer can arise from aneuploidy, genome disorganization or abnormal DNA methylation. To map such patterns, we introduce a weighted univariate clustering algorithm to guarantee linear runtime, optimality and reproducibility.

Results

We present the chromosome clustering method, establish its optimality and runtime and evaluate its performance. It uses dynamic programming enhanced with an algorithm to reduce search-space in-place to decrease runtime overhead. Using the method, we delineated outstanding genomic zones in 17 human cancer types. We identified strong continuity in dysregulation polarity—dominance by either up- or downregulated genes in a zone—along chromosomes in all cancer types. Significantly polarized dysregulation zones specific to cancer types are found, offering potential diagnostic biomarkers. Unreported previously, a total of 109 loci with conserved dysregulation polarity across cancer types give insights into pan-cancer mechanisms. Efficient chromosomal clustering opens a window to characterize molecular patterns in cancer genome and beyond.

Availability and implementation

Weighted univariate clustering algorithms are implemented within the R package ‘Ckmeans.1d.dp’ (4.0.0 or above), freely available at https://cran.r-project.org/package=Ckmeans.1d.dp.

Supplementary information

Supplementary data are available at Bioinformatics online.

Human papillomavirus type 16 E7 oncoprotein-induced upregulation of lysine-specific demethylase 5A promotes cervical cancer progression by regulating the microRNA-424-5p/suppressor of zeste 12 pathway

Human papillomavirus (HPV) infection and viral protein expression cause several epigenetic alterations that lead to cervical carcinogenesis. Our previous study identified that upregulated lysine-specific demethylase (KDM) 2 A promotes cervical cancer progression by inhibiting mircoRNA (miR)-132 function. However, the roles of histone methylation modifiers in HPV-related cervical cancer remain unclear. In the present study, changes in the expression of 48 histone methylation modifiers were assessed following knockdown of HPV16 E6/E7 in CaSki cells. The dysregulated expression of KDM5A was identified, and its function in cervical cancer was investigated in vitro and in vivo. E7 oncoprotein-induced upregulation of KDM5A promoted cervical cancer cell proliferation and invasiveness in vitro and in vivo, which was correlated with poor prognosis in patients with cervical cancer. KDM5A was found to physically interact with the promoter region of miR-424-5p, and to suppress its expression by removing the tri- and di-methyl groups from H3K4 at the miR-424-5p locus. Furthermore, miR-424-5p repressed cancer cell proliferation and invasiveness by targeting suppressor of zeste 12 (Suz12). KDM5A upregulation promoted cervical cancer progression by repressing miR-424-5p, which resulted in a decrease in Suz12. Therefore, KDM5A functions as a tumor activator in cervical cancer pathogenesis by binding to the miR-424-5p promoter and inhibiting its tumor-suppressive function. These results indicate a function for KDM5A in cervical cancer progression and suggest its candidacy as a novel prognostic biomarker and target for the clinical management of this malignancy.

Ginsenoside Rg3 inhibits growth and epithelial-mesenchymal transition of human oral squamous carcinoma cells by down-regulating miR-221

Ginsenoside Rg3, isolated from the roots of Panax ginseng, has been found to exert anti-cancer activity on multiple human cancers. However, there is no any literature available about the effect of Rg3 on oral squamous cell carcinoma (OSCC). This study investigated the possible anti-cancer effects of Rg3 on OSCC, as well as the possible molecular mechanisms. In vitro, cell viability and proliferation were respectively detected by CCK-8 assay and BrdU assay. Cell apoptosis was detected by Annexin V-FITC/PI assay. Cell transfection was used to change the expression of miR-221 and TIMP3. qRT-PCR and western blotting were performed to measure the expression of molecules involving in cell apoptosis, epithelial-mesenchymal transition (EMT) process, PI3K/AKT pathway and MAPK/ERK pathway. In vivo, OSCC orthotopic murine model was established and tumor volumes were measured. We found that Rg3 treatment inhibited viability, proliferation and EMT process of human OSCC SCC-9 and HSC-5 cells, but promoted cell apoptosis. miR-221 was highly expressed in OSCC tissues and cells. Rg3 reduced the expression of miR-221 in OSCC cells. Up-regulation of miR-221 abrogated the effects of Rg3 on SCC-9 and HSC-5 cell viability, proliferation, apoptosis and EMT process. TIMP3 was lowly expressed in OSCC tissues and cells, which was a direct target gene of miR-221. Rg3 inactivated PI3K/AKT and MAPK/ERK pathways in SCC-9 cells by up-regulating TIMP3. In vivo, Rg3 reduced the tumor volume of OSCC orthotopic murine model. In conclusion, Rg3 exerted anti-cancer effects on OSCC might be via down-regulating miR-221, up-regulating TIMP3, and then inactivating PI3K/AKT and MAPK/ERK pathways.

The Down-Regulation of SUZ12 Accelerates the Migration and Invasion of Liver Cancer Cells via Activating ERK1/2 Pathway

The suppressor of zest 12 (SUZ12), an essential subunit of the transcription polycomb repressive complex 2 (PRC2), has been found to be involved in HBV X-induced oncogenic transformation in hepatocellular carcinoma (HCC). However, the specific function of SUZ12 has not yet been determined in the pathogenesis of migration and invasion of HBV-associated HCC. Here, our results showed that SUZ12 was significantly down-regulated in HBV-related HCC tissues compared with adjacent non-tumor tissues by immunohistochemical and Western blot assays. The 5-years survival rate was worse in patients with low expression level of SUZ12. SUZ12 silencing increased the migration and invasion of HCC cells, and its overexpression impaired HCC cells migration and invasion. Knockdown of SUZ12 activated ERK1/2 pathway and increased MMP9 (matrix metallopeptidase 9) and MMP2 (matrix metallopeptidase 2) expression, whereas SUZ12 overexpression had opposite effects. Specific ERK1/2 inhibitor (SCH772984) significantly decreased HCC cells migration and invasion caused by SUZ12 shRNA. Thus, the liver cancer-down-regulated SUZ12 accelerated the invasion and metastasis of HCC cells. These effects might be associated with deregulation of SUZ12 activating ERK1/2, MMP2 and MMP9 in HCC cells.

A review of the most promising biomarkers for early diagnosis and prognosis prediction of tongue squamous cell carcinoma

BACKGROUND

There is a great interest in developing biomarkers to enhance early detection and clinical management of tongue squamous cell carcinoma (TSCC). However, the developmental path towards a clinically valid biomarker remains extremely challenging. Ideally, the initial key step in moving a newly discovered biomarker towards clinical implementation is independent replication. Therefore, the focus of this review is on biomarkers that consistently showed clinical relevance in two or more publications.

METHODS

We searched PubMed database for relevant papers across different TSCC sample sources, i.e., body fluids (saliva, serum/plasma) and tissues. No restriction regarding the date of publication was applied except for immunohistochemistry (IHC); only studies published between 2010 and June 2017 were included.

RESULTS

The search strategy identified 1429 abstracts, of which 96 papers, examining 150 biomarkers, were eventually included. Of these papers, 66% were exploratory studies evaluating single or a panel of biomarkers in one publication. Ultimately, based on studies that had undergone validation for their clinical relevance in at least two independent studies, we identified 10 promising candidates, consisting of different types of molecules (IL-6, IL-8, and Prolactin in liquid samples; HIF-1α, SOX2, E-cadherin, vimentin, MALAT1, TP53, and NOTCH1 in tissue biopsies) CONCLUSIONS: Although more exploratory research is needed with newer methods to identify biomarkers for TSCC, rigorous validation of biomarkers that have already shown unbiased assessment in at least two publications should be considered a high priority. Further research on these promising biomarkers or their combination in multi-institutional studies, could provide new possibilities to develop a specific panel for early diagnosis, prognosis, and individualized treatments.

SUZ12 is a novel putative oncogene promoting tumorigenesis in head and neck squamous cell carcinoma

The suppressor of zest 12 (SUZ12), one of the core polycomb repressive complex 2 (PRC2) components, has increasingly appreciated as a key mediator during human tumorigenesis. However, its expression pattern and oncogenic roles in head and neck squamous cell carcinoma (HNSCC) remain largely unexplored yet. Here, we sought to determine its expression pattern, clinicopathological significance and biological roles in HNSCC. Through data mining and interrogation from multiple publicly available databases, our bioinformatics analyses revealed that SUZ12 mRNA was significantly overexpressed in multiple HNSCC patient cohorts. Moreover, SUZ12 protein was markedly up‐regulated in primary HNSCC samples from our patient cohort as assessed by immunohistochemical staining and its overexpression significantly associated with cervical node metastasis and reduced overall and disease‐free survival. In the 4‐nitroquinoline 1‐oxide (4NQO)‐induced HNSCC mouse model, increased SUZ12 immunostaining was observed along with disease progression from epithelial hyperplasia to squamous cell carcinoma in tongue. Furthermore, shRNA‐mediated SUZ12 knock‐down significantly inhibited cell proliferation, migration and invasion in HNSCC cells, and resulted in compromised tumour growth in vivo. Collectively, our data reveal that SUZ12 might serve as a putative oncogene by promoting cell proliferation, migration and invasion, and also a novel biomarker with diagnostic and prognostic significance for HNSCC.

Overexpression of WD repeat domain 5 associates with aggressive clinicopathological features and unfavorable prognosis in head neck squamous cell carcinoma

BACKGROUND

WD repeat domain 5 (WDR5), a core member of Mixed lineage leukemia (MLL) and SET1 histone H3 lysine 4 (H3K4) methyltransferase complexes, is involved in multiple biological and pathological processes. Its deregulation in cancer and pro-tumorigenic roles has been increasingly appreciated. However, the expression pattern of WDR5 and its biological functions in head neck squamous cell carcinoma (HNSCC) have not been well established.

METHODS

The expression of WDR5 mRNA in HNSCC was determined by data mining and interrogation using publicly available databases. Its protein expression was measured by immunohistochemistry in a retrospective cohort of primary HNSCC samples. Moreover, the associations between WDR5 expression and various clinicopathological parameters and patient survival were assessed. The pro-tumorigenic roles of WDR5 in HNSCC were further delineated in vitro by loss-of-function assay.

RESULTS

Our bioinformatics analyses revealed that WDR5 mRNA was significantly overexpressed in 3 HNSCC cohorts. WDR5 protein was markedly upregulated in HNSCC samples as compared to normal counterparts and its overexpression significantly associated with large tumor size, advanced clinical stage (chi-square test, P = .048, .006) and reduced overall and disease-free survival (Kaplan-Mier analyses, Log-rank test, P = .0137, .0154). Univariate and multivariate survival analyses further revealed WDR5 protein abundance as an independent prognostic factor for patients' overall survival. Moreover, WDR5 knockdown significantly inhibited cell proliferation, migration and invasion, and induced cell apoptosis in HNSCC cells.

CONCLUSIONS

Our findings reveal that WDR5 is aberrantly overexpressed in HNSCC and associates with aggressiveness and unfavorable prognosis, thus representing a novel diagnostic and prognostic biomarker for HNSCC.

CBX3/HP1γ is upregulated in tongue squamous cell carcinoma and is associated with an unfavorable prognosis

Increased expression of CBX3/HP1γ, a core component of heterochromatin protein 1, has recently proved to be involved in human tumorigenesis and patient prognosis. The present study aimed to investigate the expression of CBX3/HP1γ and its clinicopathological significance in primary tongue squamous cell carcinoma (TSCC). Gene expression profiles of CBX3/HP1γ in TSCC from Oncomine database were analyzed. The expression of CBX3/HP1γ at protein level was measured using immunohistochemistry (IHC). The potential associations between CBX3/HP1γ expression and multiple clinicopathological parameters were estimated using the Chi square test. In addition, the effect of CBX3/HP1γ expression on patients' survival was further assessed by Kaplan-Meier and Cox regression analyses. The agreement of elevated CBX3/HP1γ expression was indicated in four datasets on the Oncomine database. Aberrant overexpression of CBX3/HP1γ was identified in TSCC tissues compared with cancer-adjacent normal tissue, which was significantly associated with cervical nodes metastasis (P=0.010) and clinical stage (P=0.025). Furthermore, patients with high CBX3/HP1γ expression exhibited a reduced survival compared with those with low expression (Log-rank test, P=0.004). Univariate and multivariate Cox regression analysis suggested that the expression status of CBX3/HP1γ could be regarded as an independent prognostic factor for TSCC patients (HR=2.461; 95% CI=1.128–5.370; P=0.024). The present study indicated that aberrant overexpression of Cbx3/HP1γ was associated with cervical nodes metastasis and unfavorable survival in TSCC. These findings suggest that CBX3/HP1γ may serve an important role in tongue tumorigenesis and may be a valuable candidate diagnostic and prognostic marker for TSCC patients.

Density and location of CD3+ and CD8+ tumor-infiltrating lymphocytes correlate with prognosis of oral squamous cell carcinoma

BACKGROUND

Tumor-infiltrating lymphocytes (TILs) are regarded as adaptive immune response of the host to cancer cells and valuable prognostic factors. Here, we sought to characterize the densities and locations of CD3⁺ and CD8⁺ TILs in primary oral squamous cell carcinoma (OSCC) samples and assess their clinicopathological and prognostic significance.

METHODS

A total number of 169 OSCC samples from 2 independent patient cohorts (Nanjing cohort, 93 cases; Wuxi cohort, 76 cases) were retrospectively collected. The numbers of CD3⁺ and CD8⁺ TILs at tumor center (CT) and invasive margin (IM) of OSCC were identified by immunohistochemistry and calculated. The optimal cutoff values for CD3⁺ and CD8⁺ TILs to stratify patients were determined by X-tile software in Nanjing cohort and further utilized in Wuxi cohort. The associations between CD3⁺ /CD8⁺ TILs and clinicopathological parameters or patient survival were assessed. The prognostic values of CD3⁺ / CD8⁺ TILs were evaluated by Cox regression analyses.

RESULTS

CD3⁺ and CD8⁺ TILs were identified at both CT and IM and enriched at IM. High density of CD3⁺ TILs at IM (CD3 IM) was significantly associated with increased overall and disease-specific survival (P < .05). High density of CD8⁺ TILs at CT (CD8 CT) was significantly associated with increased overall but not disease-specific survival. Moreover, CD3 IM and CD8 CT were identified as independent prognostic factors for patient survival.

CONCLUSIONS

Our findings provide further evidence to support the prognostic values of CD3⁺ and CD8⁺ TILs for OSCC, suggesting that TIL subsets might be viable biomarkers and therapeutic targets with translational significance.

Identification of Key Genes and Pathways in Tongue Squamous Cell Carcinoma Using Bioinformatics Analysis

BACKGROUND Tongue squamous cell carcinoma (TSCC) is a major type of oral cancers and has remained an intractable cancer over the past decades. The aim of this study was to identify differentially expressed genes (DEGs) during TSCC and reveal their potential mechanisms. MATERIAL AND METHODS The gene expression profiles of GSE13601 were downloaded from the GEO database. The GSE13601 dataset contains 57 samples, including 31 tongue SCC samples and 26 matched normal mucosa samples. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were performed; Cytoscape software was used for the protein-protein interaction (PPI) network and module analysis of the DEGs. RESULTS We identified a total of 1,050 upregulated DEGs (uDEGs) and 702 downregulated DEGs (dDEGs) of TSCC. The GO analysis results showed that uDEGs were significantly enriched in the following biological processes (BP): signal transduction, positive or negative regulation of cell proliferation, and negative regulation of cell proliferation. The dDEGs were significantly enriched in the following biological processes: signal transduction, cell adhesion, and apoptotic process. The KEGG pathway analysis showed that uDEGs were enriched in metabolic pathways, pathways in cancer, and PI3K-Akt signaling pathway, while the dDEGs were enriched in focal adhesion and ECM-receptor interaction. The top centrality hub genes RAC1, APP, EGFR, KNG1, AGT, and HRAS were identified from the PPI network. Module analysis revealed that TSCC was associated with significant pathways, including neuroactive ligand-receptor interaction, calcium signaling pathway, and chemokine signaling pathway. CONCLUSIONS The present study identified key genes and signal pathways, which deepen our understanding of the molecular mechanisms of carcinogenesis and development of the disease, and might be used as diagnostic and therapeutic molecular biomarkers for TSCC.