Twist-related protein 1 enhances oral tongue squamous cell carcinoma cell invasion through β-catenin signaling

The therapeutic potential of RNA m(6)A in lung cancer

Lung cancer (LC) is a highly malignant and metastatic form of cancer. The global incidence of and mortality from LC is steadily increasing; the mean 5-year overall survival (OS) rate for LC is less than 20%. This frustrating situation may be attributed to the fact that the pathogenesis of LC remains poorly understood and there is still no cure for mid to advanced LC. Methylation at the N6-position of adenosine (N6mA) of RNA (m(6)A) is widely present in human tissues and organs, and has been found to be necessary for cell development and maintenance of homeostasis. However, numerous basic and clinical studies have demonstrated that RNA m(6)A is deregulated in many human malignancies including LC. This can drive LC malignant characteristics such as proliferation, stemness, invasion, epithelial-mesenchymal transition (EMT), metastasis, and therapeutic resistance. Intriguingly, an increasing number of studies have also shown that eliminating RNA m(6)A dysfunction can exert significant anti-cancer effects on LC such as suppression of cell proliferation and viability, induction of cell death, and reversal of treatment insensitivity. The current review comprehensively discusses the therapeutic potential of RNA m(6)A and its underlying molecular mechanisms in LC, providing useful information for the development of novel LC treatment strategies.

ERK-mediated upregulation of matrix metalloproteinase-2 promotes the invasiveness in human oral squamous cell carcinoma (OSCC)

BACKGROUND

Loco-regional invasion is commonly found in oral squamous cell carcinoma (OSCC) and is associated with its poor survival rate. Matrix metalloproteinase-2 (MMP-2) has been implicated in OSCC progression, but its regulation is poorly understood.

MATERIALS AND METHODS

Here, one hundred twenty-seven different post-operated human oral cancer tissue samples were analyzed. The messenger RNA (mRNA) expression, protein expression, and MMP-2 activity and MT1-MMP, TIMP-2, and TFs (NFκB, AP1, Sp1, and Twist) were observed semi-quantitative RT-PCR, western blotting, and gelatin zymography. In addition, OSCC derived Cal-27, SCC4/9 cells, photochemical ECGC, and MAPK-pathway inhibitor PD98059 were utilized for in vitro testing and wound healing assay.

RESULT

s: Increased protein and activity level of MMP-2 was detected in non-invasive (N₀) and invasive (N_1-3) oral tumors as compared to the control (adjacent normal) samples. MMP-2 protein and mRNA expression were positively associated with the TFs and MT1-MMP, negatively associated with TIMP-2 expression. Similarly, the MMP-2 expression/activity was related to several signal-transduction pathways like ERK1/2 and wnt-β-catenin pathways. Treatment of ECGC/MEK inhibitor (PD98059) diminished MMP-2 activity and invasion/migration potential in OSCC.

CONCLUSION

Our research suggests that the ERK1/2 driven overexpression/activation of MMP-2 was linked with the overall OSCC invasion and metastasis. Treatment of MEK inhibitor (PD98059) and ECGC diminished MMP-2 activity and thus could be exploited as a therapeutic strategy to control the invasive OSCC.

Infection by High-Risk Human Papillomaviruses, Epithelial-to-Mesenchymal Transition and Squamous Pre-Malignant or Malignant Lesions of the Uterine Cervix: A Series of Chained Events?

Wound healing requires static epithelial cells to gradually assume a mobile phenotype through a multi-step process termed epithelial-to-mesenchymal transition (EMT). Although it is inherently transient and reversible, EMT perdures and is abnormally activated when the epithelium is chronically exposed to pathogens: this event deeply alters the tissue and eventually contributes to the development of diseases. Among the many of them is uterine cervical squamous cell carcinoma (SCC), the most frequent malignancy of the female genital system. SCC, whose onset is associated with the persistent infection of the uterine cervix by high-risk human papillomaviruses (HR-HPVs), often relapses and/or metastasizes, being resistant to conventional chemo- or radiotherapy. Given that these fearsome clinical features may stem, at least in part, from the exacerbated and long-lasting EMT occurring in the HPV-infected cervix; here we have reviewed published studies concerning the impact that HPV oncoproteins, cellular tumor suppressors, regulators of gene expression, inflammatory cytokines or growth factors, and the interactions among these effectors have on EMT induction and cervical carcinogenesis. It is predictable and desirable that a broader comprehension of the role that EMT inducers play in SCC pathogenesis will provide indications to flourish new strategies directed against this aggressive tumor.

Knockdown of METTL14 suppresses the malignant progression of non-small cell lung cancer by reducing Twist expression

Non-small cell lung cancer (NSCLC) is one of the most malignant cancer types. N6-methyladenosine (m6A), an abundant eukaryotic mRNA modification, has been observed in multiple diseases, particularly cancer. Methyltransferase-like 14 (METTL14) is a central component of the m6A methyltransferase complex and has been reported to promote tumor development in several cancer types. The present study aimed to investigate the role of METTL14 in NSCLC. Relevant clinical and mRNA sequencing data for m6A-related genes were downloaded from The Cancer Genome Atlas database. R software was used to evaluate the expression of m6A regulators in NSCLC. The biological functions of METTL14 were evaluated using Cell Counting Kit-8, colony formation, Transwell migration and western blot analyses. The results demonstrated that METTL14 expression was upregulated in NSCLC tissues and cell lines, and its expression was high in cancer tissues from patients with NSCLC with all four stages (I, II, III and IV) of disease. METTL14 downregulation inhibited cell proliferation and migration in A549 and SK-MES-1 lung cancer cell lines. Knockdown of METTL14 in lung cancer cell lines increased E-cadherin expression and suppressed N-cadherin expression. Furthermore, METTL14 downregulation reduced the expression levels of the transcription factor Twist and the p-AKT/AKT ratio. In conclusion, the present findings revealed that silencing of METTL14 suppressed NSCLC malignancy by inhibiting Twist-mediated activation of AKT signaling. These data suggest that METTL14 may be a potential therapeutic target for NSCLC.

miRNA-200a Regulating Proliferation, Migration, and Infiltration of Tongue Squamous Cell Carcinoma Cells by Targeting DEK Proto-Oncogene

Tongue squamous cell carcinoma (TSCC) is the most frequently occurring oral cancer and is characterized by high proliferation and metastasis rates. Incomplete understanding of the pathogenesis of TSCC coupled with frequent tongue movement increases the difficulty of therapy. Additionally, TSCC is prone to recurrence and metastasis after treatment. Thus, exploring mechanisms of proliferation, migration, and infiltration of TSCC cancer cells is essential for reducing morbidity and mortality. Transfection of miRNA-200a mimics into SCC15 cells showed that miRNA-200a expression decreased significantly, and DEK expression significantly increased. Transfection of miRNA-200a mimics (miRNA-200a group), negative control mimics (miRNA-NC group), empty vector (miRNA-200a + pcDNA3.1 group), and miRNA-200a mimics and DEK overexpression vector (miRNA-200a + DEK group) into SCC15 cells respectively indicates that overexpression of miRNA-200a substantially inhibits SCC15 cell proliferation, infiltration and migration, decreases PCNA and Vimentin expression, and promotes E-cadherin expression. miRNA-200a + DEK transfection induced greater cell proliferation, infiltration and migration, much higher PCNA and Vimentin expression, and significantly lower E-cadherin expression. Luciferase reporter gene detection of overexpressed DEK or DEK expression after inhibiting miRNA-200a expression indicated a targeting association between miRNA-200a and DEK. miRNA-200a inhibits proliferation, infiltration and migration ability of TSCC by targeting DEK and may represent a novel means for clinical intervention in TSCC. miRNA-200a inhibits proliferation, invasion, and migration of TSCC by targeting DEK.

Role of Twist and Podoplanin in Partial Epithelial-Mesenchymal Transition in Oral Squamous Cell Carcinoma

The aim of this study was to perform a comparative analysis of podoplanin (PDPN) and Twist immunoexpressions in lower lip and oral tongue squamous cell carcinomas (LLSCC and OTSCC, respectively). PDPN and Twist immunoexpressions were semi-quantitatively evaluated by analyzing the invasion front, the compressive areas, the large islands and nests and dissociated cells of the chosen carcinomas. Their statistical associations and correlations with clinical-pathological characteristics were verified by the Mann-Whitney and Spearman's test. Twist expression was low in both carcinomas, with <25% labeling on the invasive front. Significant differences were observed for LLSCC (p=0.032) and OTSCC (p=0.025) regarding PDPN immunoexpression in relation to the worst invasion patterns determined by a histological malignancy gradation system. Statistically significant negative correlations between PDPN membrane expression and general (r=-0.356, p=0.024) and cytoplasmic Twist expressions (r=-0.336; p=0.034) in LLSCC were also observed. Twist and PDPN are suggested to be associated to a more aggressive invasion pattern in both LLSCC and OTSCC cases but not related to the different biological behaviors on these anatomical sites. Also, it was seen that PDPN membrane expression is inversely related to general and cytoplasmic Twist expression in LLSCC cases.

The Significance of the Dysregulation of Canonical Wnt Signaling in Head and Neck Squamous Cell Carcinomas

The knowledge about the molecular alterations which are found in head and neck squamous cell carcinomas (HNSCC) has much increased in recent years. However, we are still awaiting the translation of this knowledge to new diagnostic and therapeutic options. Among the many molecular changes that are detected in head and neck cancer, the abnormalities in several signaling pathways, which regulate cell proliferation, cell death and stemness, seem to be especially promising with regard to the development of targeted therapies. Canonical Wnt signaling is a pathway engaged in the formation of head and neck tissues, however it is not active in adult somatic mucosal cells. The aim of this review paper is to bring together significant data related to the current knowledge on the mechanisms and functional significance of the dysregulation of the Wnt/β-catenin pathway in head and neck tumors. Research evidence related to the role of Wnt signaling activation in the stimulation of cell proliferation, migration and inhibition of apoptosis in HNSCC is presented. Moreover, its role in promoting stemness traits in head and neck cancer stem-like cells is described. Evidence corroborating the hypothesis that the Wnt signaling pathway is a very promising target of novel therapeutic interventions in HNSCC is also discussed.

Glycogen synthase kinase-3β mediated regulation of matrix metalloproteinase-9 and its involvement in oral squamous cell carcinoma progression and invasion

PURPOSE

Oral squamous cell carcinoma (OSCC)-related deaths mainly result from invasion of the tumor cells into local cervical lymph nodes. It has been reported that progressive basement membrane loss promotes the metastatic and invasive capacities of OSCCs. Matrix metalloproteinase-9 (MMP-9) is known to play a central role in tumor progression and invasion. However, the role of MMP-9 in OSCC invasion has so far remained paradoxical and little is known about its regulation. Here, we aimed to assess MMP-9 expression regulation and its activation by glycogen synthase kinase-3β during human OSCC progression and invasion.

METHODS

In the present study, 178 human OSCC samples, including 118 fresh samples (18 adjacent normal, 42 noninvasive and 58 invasive tumor samples) and 60 archival human tissue microarray (TMA) tongue cancer samples, were included. mRNA expression, protein expression, MMP-9/-2 activity, protein-protein interaction and Snail, c-Myc, β-catenin and TIMP1 expression were assessed using RT-PCR, immunohistochemistry, Western blotting, co-immunoprecipitation and gelatin zymography analyses, respectively. Wnt5a and LPA mediated MMP-9 regulation was assessed in OCSCC-derived SCC-9 cells exogenously expressing GSK3β (WT) or non phosphoryable GSK3β (S9A).

RESULTS

We observed a progressive up-regulation/activation of MMP-9 at various stages of oral tumor progression/invasion. Positive correlations were observed between MMP-9 and c-Myc expression, MMP-9 and MMP-2 activity, MMP-9 and TIMP1 expression and MMP-9 activity and TIMP1-MMP-9 interaction. In contrast, a negative correlation between phosphorylated β-catenin and MMP-9 expression was observed. Conversely, we found that in oral tongue SCC MMP-9 expression was positively correlated with inactivation of GSK3 signaling. Finally, we found that Wnt5a and LPA mediated increased MMP-9 and decreased GSK3β activities in tongue SCC-derived SCC-9 cells. MMP-9 regulation by GSK3β was confirmed by using phosphoryable/regulatory GSK3β (WT construct) and not by non-phosphoryable GSK3β (S9A construct).

CONCLUSIONS

Collectively, our results show that MMP-9 overexpression and activation are important events occurring during OSCC progression/invasion and that this overexpression/activation is regulated by c-Myc, active MMP-2 and inactive GSK3β mediated pathways.

Hierarchical clustering analysis identifies metastatic colorectal cancers patients with more aggressive phenotype

A large percentage of metastatic colorectal cancer (mCRC) patients presents metastasis at the time of diagnosis. In the last years, great efforts have been made in the treatment of these patients with the identification of different phenotypes playing a key role in the definition of new systemic therapies. Unsupervised hierarchical clustering analysis (HCA) was performed considering the clinicopathological characteristics of 51 mCRCs. Using immunohistochemistry on tissue microarrays, we assessed the expression of β-catenin, NHERF1, RASSF1A, TWIST1, HIF-1α proteins in tumors and paired liver metastases. We also analyzed RASSF1A methylation status on the samples of the same patients. HCA distinguished Group 1 and Group 2 characterized by different clinicopathological features. Group 1 was characterized by higher number of positive lymph nodes (p=0.0139), poorly differentiated grade (p<0.0001) and high extent of tumor spread (p=0.0053) showing a more aggressive phenotype compared to Group 2. In both Groups, we found a common "basal" condition with a higher level of nuclear TWIST1 (p<0.0001 and cytoplasmic β-catenin (p<0.0001) in tumors than in paired liver metastases. Furthermore, the Group 1 was also characterized by RASSF1A hypermethylation (p<0.0001) and nuclear HIF-1α overexpression (p=0.0354) in paired liver metastases than in tumors. In conclusion, HCA identifies mCRC patients with a more aggressive phenotype. Moroever, our results support the important contribution to the progression of the disease of RASSF1A methylation and the oncogenic role of HIF-1α in these patients. These evidences, should provide relevant information concerning the biology of this tumor and, as a consequence, potential new systemic therapeutic approaches.

Roles of GSK-3 and microRNAs on epithelial mesenchymal transition and cancer stem cells

Various signaling pathways exert critical roles in the epithelial to mesenchymal transition (EMT) and cancer stem cells (CSCs). The Wnt/beta-catenin, PI3K/PTEN/Akt/mTORC, Ras/Raf/MEK/ERK, hedgehog (Hh), Notch and TP53 pathways elicit essential regulatory influences on cancer initiation, EMT and progression. A common kinase involved in all these pathways is moon-lighting kinase glycogen synthase kinase-3 (GSK-3). These pathways are also regulated by micro-RNAs (miRs). TP53 and components of these pathways can regulate the expression of miRs. Targeting members of these pathways may improve cancer therapy in those malignancies that display their abnormal regulation. This review will discuss the interactions of the multi-functional GSK-3 enzyme in the Wnt/beta-catenin, PI3K/PTEN/Akt/mTORC, Ras/Raf/MEK/ERK, Hh, Notch and TP53 pathways. The regulation of these pathways by miRs and their effects on CSC generation, EMT, invasion and metastasis will be discussed.

Two different protein expression profiles of oral squamous cell carcinoma analyzed by immunoprecipitation high-performance liquid chromatography

Background

Oral squamous cell carcinoma (OSCC) is one of the most dangerous cancers in the body, producing serious complications with individual behaviors. Many different pathogenetic factors are involved in the carcinogenesis of OSCC. Cancer cells derived from oral keratinocytes can produce different carcinogenic signaling pathways through differences in protein expression, but their protein expression profiles cannot be easily explored with ordinary detection methods.

Methods

The present study compared the protein expression profiles between two different types of OSCCs, which were analyzed through immunoprecipitation high-performance liquid chromatography (IP-HPLC).

Results

Two types of squamous cell carcinoma (SCC) occurred in a mandibular (SCC-1) and maxillary gingiva (SCC-2), but their clinical features and progression were quite different from each other. SCC-1 showed a large gingival ulceration with severe halitosis and extensive bony destruction, while SCC-2 showed a relatively small papillary gingival swelling but rapidly grew to form a large submucosal mass, followed by early cervical lymph node metastasis. In the histological observation, SCC-1 was relatively well differentiated with a severe inflammatory reaction, while SCC-2 showed severely infiltrative growth of each cancer islets accompanied with a mild inflammatory reaction. IP-HPLC analysis revealed contrary protein expression profiles analyzed by 72 different oncogenic proteins. SCC-1 showed more cellular apoptosis and invasive growth than SCC-2 through increased expression of caspases, MMPs, p53 signaling, FAS signaling, TGF-β1 signaling, and angiogenesis factors, while SCC-2 showed more cellular growth and survival than SCC-1 through the increased expression of proliferating factors, RAS signaling, eIF5A signaling, WNT signaling, and survivin.

Conclusions

The increased trends of cellular apoptosis and invasiveness in the protein expression profiles of SCC-1 were implicative of its extensive gingival ulceration and bony destruction, while the increased trends of cellular proliferation and survival in the protein profile of SCC-2 were implicative of its rapid growing tumor mass and early lymph node metastasis. These analyses of the essential oncogenic protein expression profiles in OSCC provide important information for genetic counseling or customized gene therapy in cancer treatment. Therefore, protein expression profile analysis through IP-HPLC is helpful not only for the molecular genetic diagnosis of cancer but also in identifying target molecules for customized gene therapy in near future.

Nicotine may promote tongue squamous cell carcinoma progression by activating the Wnt/β-catenin and Wnt/PCP signaling pathways

To investigate the effects and the possible underlying mechanisms of nicotine stimulation on tongue squamous cell carcinoma (TSCC) progression, a TSCC cell line Cal27 and 34 samples of paraffin-embedded TSCC were examined. Immunofluorescence, western blot analysis, and TOP/FOP flash, CCK-8, wound healing and Transwell invasion assays were used to evaluate Cal27 in response to nicotine stimulation. We also investigated expression levels of related proteins of Wnt/β-catenin and Wnt/PCP pathways in paraffin-embedded TSCC samples with or without a history of smoking by immunohistochemistry. Nicotine stimulation can promote proliferation, migration, and invasion of TSCC cells in vitro, downregulate E-cadherin, and activate the Wnt/β-catenin and Wnt/PCP pathways, which could be antagonized by the α7 nicotine acetylcholine receptor (α7 nAChR) inhibitor α-BTX. Moreover, the expression levels of β-catenin, Wnt5a and Ror2 were higher in TSCC patients with a history of smoking than those without a history of smoking. Our results suggest nicotine may promote tongue squamous carcinoma cells progression by activating the Wnt/β-catenin and Wnt/PCP signaling pathways and may play a significant role in the progression and metastasis of smoking-related TSCC.