Protease-activated Receptor-2 (PAR-2)-mediated Nf-κB Activation Suppresses Inflammation-associated Tumor Suppressor MicroRNAs in Oral Squamous Cell Carcinoma

Linagliptin's impact on lymphatic barrier and lymphangiogenesis in oral cancer with high glucose

OBJECTIVES

Uncertainties remain regarding the effect of elevated glucose levels on lymphatic metastasis of cancer cells. Our study elucidated the mechanisms linking high glucose to lymphangiogenesis and lymphatic barrier-related factors and investigated the protective role of linagliptin against lymphatic barrier dysfunction.

MATERIALS AND METHODS

A CAL-27-LEC co-culture system was established. Sodium fluorescein permeability assay observed lymphatic endothelial cell permeability. Western blotting and RT-qPCR detected protein and mRNA expression under different conditions, respectively. CCK-8, scratch wound healing, and transwell assays revealed cell migration and proliferation. Tube formation experiment tested capacity for endothelial tube formation. Immunohistochemical staining analyzed tissue sections from 43 oral cancer individuals with/without diabetes.

RESULTS

In high-glucose co-culture system, we observed increased lymphatic barrier permeability and decreased expression of ZO-1 and occludin, two tight-junction proteins; conversely, the expression of PAR2, a high permeability-related protein, was increased. Following linagliptin treatment, the expression levels of VEGF-C, VEGFR-3, and PAR2 decreased, while those of ZO-1 and occludin increased. Considerably higher levels of LYVE-1 expression in individuals with diabetes than in those without diabetes.

CONCLUSIONS

By ameliorating the high glucose-induced disruption of the lymphatic endothelial barrier, linagliptin may reduce lymphangiogenesis and exhibit an inhibitory effect on lymphatic metastasis in oral cancer patients with diabetes.

CaCO3 Nanoparticles Delivering MicroRNA-200c Suppress Oral Squamous Cell Carcinoma

MicroRNA (miR)-200c suppresses the initiation and progression of oral squamous cell carcinoma (OSCC), the most prevalent head and neck cancer with high recurrence, metastasis, and mortality rates. However, miR-200c-based gene therapy to inhibit OSCC growth has yet to be reported. To develop an miR-based gene therapy to improve the outcomes of OSCC treatment, this study investigates the feasibility of plasmid DNA (pDNA) encoding miR-200c delivered via nonviral CaCO3-based nanoparticles to inhibit OSCC tumor growth. CaCO3-based nanoparticles with various ratios of CaCO3 and protamine sulfate (PS) were used to transfect pDNA encoding miR-200c into OSCC cells, and the efficiency of these nanoparticles was evaluated. The proliferation, migration, and associated oncogene production, as well as in vivo tumor growth for OSCC cells overexpressing miR-200c, were also quantified. It was observed that, while CaCO3-based nanoparticles improve transfection efficiencies of pDNA miR-200c, the ratio of CaCO3 to PS significantly influences the transfection efficiency. Overexpression of miR-200c significantly reduced proliferation, migration, and oncogene expression of OSCC cells, as well as the tumor size of cell line-derived xenografts (CDX) in mice. In addition, a local administration of pDNA miR-200c using CaCO3 delivery significantly enhanced miR-200c transfection and suppressed tumor growth of CDX in mice. These results strongly indicate that the nanocomplexes of CaCO3/pDNA miR-200c may potentially be used to reduce oral cancer recurrence and improve clinical outcomes in OSCC treatment, while more comprehensive examinations to confirm the safety and efficacy of the CaCO3/pDNA miR-200c system using various preclinical models are needed.

CaCO 3 Nanoparticles Delivering MicroRNA-200c Suppress Oral Squamous Cell Carcinoma

MicroRNA (miR)-200c suppresses the initiation and progression of oral squamous cell carcinoma (OSCC), the most prevalent head and neck cancer with high recurrence, metastasis, and mortality rates. However, miR-200c -based gene therapy to inhibit OSCC growth and metastasis has yet to be reported. To develop an miR-based gene therapy to improve the outcomes of OSCC treatment, this study investigates the feasibility of plasmid DNA encoding miR-200c delivered via non-viral CaCO 3 -based nanoparticles to inhibit OSCC tumor growth. CaCO 3 -based nanoparticles with various ratios of CaCO 3 and protamine sulfate (PS) were utilized to transfect pDNA encoding miR-200c into OSCC cells and the efficiency of these nanoparticles was evaluated. The proliferation, migration, and associated oncogene production, as well as in vivo tumor growth for OSCC cells overexpressing miR-200c were also quantified. It was observed that, while CaCO 3 -based nanoparticles improve transfection efficiencies of pDNA miR-200c , the ratio of CaCO 3 to PS significantly influences the transfection efficiency. Overexpression of miR-200c significantly reduced proliferation, migration, and oncogene expression of OSCC cells, as well as the tumor size of cell line-derived xenografts (CDX) in mice. In addition, a local administration of pDNA miR-200c using CaCO 3 delivery significantly enhanced miR-200c transfection and suppressed tumor growth of CDX in mice. These results strongly indicate that the nanocomplexes of CaCO 3 /pDNA miR-200c may potentially be used to reduce oral cancer recurrence and metastasis and improve clinical outcomes in OSCC treatment. (227 words).

Tissue factor (coagulation factor III): a potential double-edge molecule to be targeted and re-targeted toward cancer

Tissue factor (TF) is a protein that plays a critical role in blood clotting, but recent research has also shown its involvement in cancer development and progression. Herein, we provide an overview of the structure of TF and its involvement in signaling pathways that promote cancer cell proliferation and survival, such as the PI3K/AKT and MAPK pathways. TF overexpression is associated with increased tumor aggressiveness and poor prognosis in various cancers. The review also explores TF's role in promoting cancer cell metastasis, angiogenesis, and venous thromboembolism (VTE). Of note, various TF-targeted therapies, including monoclonal antibodies, small molecule inhibitors, and immunotherapies have been developed, and preclinical and clinical studies demonstrating the efficacy of these therapies in various cancer types are now being evaluated. The potential for re-targeting TF toward cancer cells using TF-conjugated nanoparticles, which have shown promising results in preclinical studies is another intriguing approach in the path of cancer treatment. Although there are still many challenges, TF could possibly be a potential molecule to be used for further cancer therapy as some TF-targeted therapies like Seagen and Genmab's tisotumab vedotin have gained FDA approval for treatment of cervical cancer. Overall, based on the overviewed studies, this review article provides an in-depth overview of the crucial role that TF plays in cancer development and progression, and emphasizes the potential of TF-targeted and re-targeted therapies as potential approaches for the treatment of cancer.

Differential Expression of MED12-Associated Coding RNA Transcripts in Uterine Leiomyomas

Recent studies have demonstrated that somatic MED12 mutations in exon 2 occur at a frequency of up to 80% and have a functional role in leiomyoma pathogenesis. The objective of this study was to elucidate the expression profile of coding RNA transcripts in leiomyomas, with and without these mutations, and their paired myometrium. Next-generation RNA sequencing (NGS) was used to systematically profile the differentially expressed RNA transcripts from paired leiomyomas (n = 19). The differential analysis indicated there are 394 genes differentially and aberrantly expressed only in the mutated tumors. These genes were predominantly involved in the regulation of extracellular constituents. Of the differentially expressed genes that overlapped in the two comparison groups, the magnitude of change in gene expression was greater for many genes in tumors bearing MED12 mutations. Although the myometrium did not express MED12 mutations, there were marked differences in the transcriptome landscape of the myometrium from mutated and non-mutated specimens, with genes regulating the response to oxygen-containing compounds being most altered. In conclusion, MED12 mutations have profound effects on the expression of genes pivotal to leiomyoma pathogenesis in the tumor and the myometrium which could alter tumor characteristics and growth potential.

Protease-activated receptors in health and disease

Proteases are signaling molecules that specifically control cellular functions by cleaving protease-activated receptors (PARs). The four known PARs are members of the large family of G protein-coupled receptors. These transmembrane receptors control most physiological and pathological processes and are the target of a large proportion of therapeutic drugs. Signaling proteases include enzymes from the circulation; from immune, inflammatory epithelial, and cancer cells; as well as from commensal and pathogenic bacteria. Advances in our understanding of the structure and function of PARs provide insights into how diverse proteases activate these receptors to regulate physiological and pathological processes in most tissues and organ systems. The realization that proteases and PARs are key mediators of disease, coupled with advances in understanding the atomic level structure of PARs and their mechanisms of signaling in subcellular microdomains, has spurred the development of antagonists, some of which have advanced to the clinic. Herein we review the discovery, structure, and function of this receptor system, highlight the contribution of PARs to homeostatic control, and discuss the potential of PAR antagonists for the treatment of major diseases.

miR-125b Promotes the Proliferation, Migration and Invasion of Oral Squamous Cell Carcinoma (OSCC)

miR-125b is involved in several tumors. However, miR-125b’s role in oral squamous cell carcinoma (OSCC) is unclear. Tumor tissues and oral normal mucosa tissues of OSCC patients were collected to measure miR-125b level. Oral cancer Tca8113 cells were separated into control group, miR-125b inhibitor group, and miR-125b mimics group, followed by measuring miR-125b level by real time PCR, cell survival, migration and invasion, PI3K/mTOR signaling protein level by Western blot. miR-125b was upregulated in OSCC tumor tissues and related to clinical/TNM stage, metastasis and overall survival (P < 0.05). miR-125b overexpression significantly promoted tumor cell behaviors and increased PI3K/mTOR phosphorylation (P < 0.05); while inhibiting miR-125b expression significantly inhibited tumor cell biological behaviors, and decreased PI3K/mTOR phosphorylation (P < 0.05). miR-125b level is increased in OSCC tumor tissues, which is related to clinicopathological characteristics. miR-125b overexpression promotes OSCC cell behaviors by regulating PI3K/mTOR signaling.

GB83, an Agonist of PAR2 with a Unique Mechanism of Action Distinct from Trypsin and PAR2-AP

Protease-activated receptor 2 (PAR2) is a G-protein-coupled receptor (GPCR) activated by proteolytic cleavage of its N-terminal domain. Once activated, PAR2 is rapidly desensitized and internalized by phosphorylation and β-arrestin recruitment. Due to its irreversible activation mechanism, some agonists that rapidly desensitized PAR2 have been misconceived as antagonists, and this has impeded a better understanding of the pathophysiological role of PAR2. In the present study, we found that GB83, initially identified as a PAR2 antagonist, is a bona fide agonist of PAR2 that induces unique cellular signaling, distinct from trypsin and PAR2-activating peptide (AP). Activation of PAR2 by GB83 markedly elicited an increase in intracellular calcium levels and phosphorylation of MAPKs, but in a delayed and sustained manner compared to the rapid and transient signals induced by trypsin and PAR2-AP. Interestingly, unlike PAR2-AP, GB83 and trypsin induced sustained receptor endocytosis and PAR2 colocalization with β-arrestin. Moreover, the recovery of the localization and function of PAR2 was significantly delayed after stimulation by GB83, which may be the reason why GB83 is recognized as an antagonist of PAR2. Our results revealed that GB83 is a bona fide agonist of PAR2 that uniquely modulates PAR2-mediated cellular signaling and is a useful pharmacological tool for studying the pathophysiological role of PAR2.

Activation of PAR2 promotes high-fat diet-induced renal injury by inducing oxidative stress and inflammation

A high-fat diet (HFD) is a major risk factor for chronic kidney disease. Although HFD promotes renal injury, characterized by increased inflammation and oxidative stress leading to fibrosis, the underlying mechanism remains elusive. Here, we investigated the role and mechanism of protease-activating receptor 2 (PAR2) activation during HFD-induced renal injury in C57/BL6 mice. HFD for 16 weeks resulted in kidney injury, manifested by increased blood levels of blood urea nitrogen, increased levels of oxidative stress with inflammation, and structural changes in the kidney tubules. HFD-fed kidneys showed elevated PAR2 expression level in the tubular epithelial region. To elucidate the role of PAR2, PAR2 knockout mice and their littermates were administered HFD. PAR2 deficient kidneys showed reduced extent of renal injury. PAR2 deficient kidneys showed significantly decreased levels of inflammatory gene expression and macrophage infiltration, followed by reduced accumulation of extracellular matrix proteins. Using NRK52E kidney epithelial cells, we further elucidated the mechanism and role of PAR2 activation during renal injury. Palmitate treatment increased PAR2 expression level in NRK52E cells and scavenging of oxidative stress blocked PAR2 expression. Under palmitate-treated conditions, PAR2 agonist-induced NF-κB activation level was higher with increased chemokine expression level in the cells. These changes were attenuated by the depletion of oxidative stress. Taken together, our results suggest that HFD-induced PAR2 activation is associated with increased levels of renal oxidative stress, inflammatory response, and fibrosis.

Remodelling of the tumour microenvironment by the kallikrein-related peptidases

Kallikrein-related peptidases (KLKs) are critical regulators of the tumour microenvironment. KLKs are proteolytic enzymes regulating multiple functions of bioactive molecules including hormones and growth factors, membrane receptors and the extracellular matrix architecture involved in cancer progression and metastasis. Perturbations of the proteolytic cascade generated by these peptidases, and their downstream signalling actions, underlie tumour emergence or blockade of tumour growth. Recent studies have also revealed their role in tumour immune suppression and resistance to cancer therapy. Here, we present an overview of the complex biology of the KLK family and its context-dependent nature in cancer, and discuss the different therapeutic strategies available to potentially target these proteases.

Therapeutic Perspectives for the Perioperative Period in Oral Squamous Cell Carcinoma (OSCC)

The perioperative period is the relatively short window of time, usually measured in days or weeks, around the surgical procedure. Despite its short duration, this time period is of great importance for cancer patients. From a biological point of view, the perioperative period is complex. Synchronous with primary tumor removal, surgery has local and distant consequences, including systemic and local inflammation, coagulation and sympathetic activation. Furthermore, the patients often present comorbidities and receive several medical prescriptions (hypnotics, pain killers, anti-emetics, hemostatics, inotropes, antibiotics). Because of the complex nature of the perioperative period, it is often difficult to predict the oncological outcome of tumor resection. Here, we review the biological consequences of surgery of Oral Squamous Cell Carcinoma (OSCC), the most frequent form of primary head and neck tumors. We briefly address the specificities and the challenges of the surgical care of these tumors and highlight the biological and clinical studies that offer insight into the perioperative period. The recent trials examining neoadjuvant immunotherapy for OSCC illustrate the therapeutic opportunities offered by the perioperative period.

Kallikrein 5 Inhibition by the Lympho-Epithelial Kazal-Type Related Inhibitor Hinders Matriptase-Dependent Carcinogenesis

Head and neck squamous cell carcinoma remains challenging to treat with no improvement in survival rates over the past 50 years. Thus, there is an urgent need to discover more reliable therapeutic targets and biomarkers for HNSCC. Matriptase, a type-II transmembrane serine protease, induces malignant transformation in epithelial stem cells through proteolytic activation of pro-HGF and PAR-2, triggering PI3K-AKT-mTOR and NFKB signaling. The serine protease inhibitor lympho-epithelial Kazal-type-related inhibitor (LEKTI) inhibits the matriptase-driven proteolytic pathway, directly blocking kallikreins in epithelial differentiation. Hence, we hypothesized LEKTI could inhibit matriptase-dependent squamous cell carcinogenesis, thus implicating kallikreins in this process. Double-transgenic mice with simultaneous expression of matriptase and LEKTI under the keratin-5 promoter showed a prominent rescue of K5-Matriptase^+/0 premalignant phenotype. Notably, in DMBA-induced SCC, heterotopic co-expression of LEKTI and matriptase delayed matriptase-driven tumor incidence and progression. Co-expression of LEKTI reverted altered Kallikrein-5 expression observed in the skin of K5-Matriptase^+/0 mice, indicating that matriptase-dependent proteolytic pathway inhibition by LEKTI occurs through kallikreins. Moreover, we showed that Kallikrein-5 is necessary for PAR-2-mediated IL-8 release, YAP1-TAZ/TEAD activation, and matriptase-mediated oral squamous cell carcinoma migration. Collectively, our data identify a third signaling pathway for matriptase-dependent carcinogenesis in vivo. These findings are critical for the identification of more reliable biomarkers and effective therapeutic targets in Head and Neck cancer.

Salivary KLK5 and uPA are potential biomarkers for malignant transformation of OLK and OLP

BACKGROUND

Oral squamous cell carcinoma (OSCC) usually originates from oral potentially malignant disorders (OPMD), such as oral leukoplakia (OLK) and oral lichen planus (OLP). Identifying biomarkers for the early diagnosis and evaluation of malignant transformation in OPMD could improve the survival rate of OSCC patients.

OBJECTIVE

The present study aimed to screen for potential salivary biomarkers for evaluating the malignant transformation of OPMD.

METHODS

Salivary proteases from OLK and OSCC patients or healthy donors and proteases in cultural medium from DOK and Cal-27 cells were detected with a human protease array kit. The concentrations of the salivary Kallikrein 5 (KLK5) and urokinase-type plasminogen activator (uPA) proteases were measured by ELISA. Receiver operating characteristics (ROC) to determine the potential value of these proteases in clinical diagnosis were calculated using SPSS software. Immunohistochemistry was used to detect the KLK5 and uPA expression in the oral organizations.

RESULTS

The salivary protease spectrum was different among patients with OLK and OSCC and healthy donors. KLK5 and uPA levels in saliva tended to increase as the disease progressed (healthy < OPMD [OLK and OLP] < OSCC). ROC curves showed the optimum diagnostic cutoffs for KLK5 as a biomarker for OLK, OLP, and OSCC were 5.97, 6.03, and 9.45 pg/mL, respectively, while the cutoffs for uPA were 17.19, 17.26, and 20.96 pg/mL. Their combined analysis showed a higher sensitivity for the differential diagnosis of disease. Furthermore, higher levels of KLK5 and uPA were observed in OSCC tissues than in OLK and OLP.

CONCLUSIONS

Salivary KLK5 and uPA are potential biomarkers for evaluating OLK and OLP malignant transformation and early diagnosis of OSCC.

Relationship Between mir15b and Sal-Like Protein 4 and Biological Behavior of Oral Squamous Cell Carcinoma

miR15b and SALL4 are involved in a variety of tumor progression. The roles of miR15b and SALL4 in oral squamous cell carcinoma (OSCC) remains unclear. The tumors and normal mucosa of OSCC patients were collected to detect miR15b and SALL4 level by Real-time PCR and analyze their correlation with OSCC clinicopathological features. Oral cancer Tca8113 cells were separated into control group; miR15b mimics group and miR15b inhibitor group followed by analysis of SALL4 expression, cell survival by MTT assay; cell invasion by Transwell chamber assay, as well as expression of N-cadherin and Vimentin and correlated with TNM stage, tumor volume and metastasis, and positively with differentiation TGF-β by Western blot. miR15b expression was decreased and SALL4 expression was increased in OSCC tumor tissues. miR15b was negatively degree (P < 0.05), whereas, opposite correlation of SALL4 with the above parameters was found (P < 0.05). miR15b and SALL4 were negatively correlated. MiR15b mimics significantly up-regulated MiR15b, decreased SALL4 expression, inhibited Tca8113 cell proliferation and invasion, as well as reduced N-cadherin, Vimentin and TGF-βexpression (P < 0.05). Opposite results were found in MiR15b inhibitor group. MiR15b expression is decreased and SALL 4 is increased in OSCC tumor tissues. MiR15b and SALL4 is closely related to OSCC clinicopathological features. MiR15b regulates the expression of EMT-related genes and TGF-β, thereby altering the proliferation and invasion of OSCC cells.

Let-7d-5p suppresses inflammatory response in neonatal rats with necrotizing enterocolitis via LGALS3-mediated TLR4/NF-κB signaling pathway

Necrotizing enterocolitis (NEC) is an acute intestinal condition accounting for severe mortality and morbidity in preterm infants. This study aimed to identify the possible roles of let-7d-5p in neonatal rats with NEC. The differentially expressed genes (DEGs) related to NEC were initially screened in silico. After establishment of NEC rat models, measurement of the expression of let-7d-5p, galectin-3 (LGALS3), Toll-like receptor 4 (TLR4), and nuclear factor-κB (NF-κB) as well as proinflammatory cytokines (TNF-α, IL-1β, and IL-6) was conducted. The interaction between let-7d-5p and LGALS3 or argonaute-2 (AGO2) was identified. Gain- and loss-of-function approaches were then performed in an attempt to investigate the regulatory roles of let-7d-5p and LGALS3 in inflammation and cell apoptosis in NEC neonatal rats. Let-7d-5p was poorly expressed, whereas LGALS3, TLR4, and NF-κB were highly expressed, in the intestinal tissues of NEC rats. Overexpression of let-7d-5p resulted in decreased levels of proinflammatory factors in the intestinal tissues of NEC rats. Through sequential experimentation, let-7d-5p was identified to target LGALS3 and bind to AGO2. In addition, LGALS3 silencing or LPS treatment blocked the TLR4/NF-κB signaling pathway, thereby suppressing intestinal epithelial cell apoptosis and inflammation in NEC. Collectively, let-7d-5p might exercise its inhibitory properties in the inflammatory response and intestinal epithelial cell apoptosis in NEC neonatal rats via inactivation of the LGALS3-dependent TLR4/NF-κB signaling pathway.

Proteinase-activated receptor 2 promotes 3T3-L1 preadipocyte differentiation through activation of the PI3K/AKT signalling pathway and MAT2A gene expression

The present study aimed to investigate the function and mechanisms of PAR2 in preadipocyte differentiation. This study found that the expression level of PAR2 was increased during 3T3-L1 mouse preadipocyte differentiation towards adipocytes. In addition, PAR2 overexpression significantly stimulated the expression of adipogenic proteins including ACC1, PPARγ, and SREBF1. Moreover, PAR2 overexpression increased the content of triglyceride (TG) in 3T3-L1 preadipocytes. Knockdown of PAR2 suppressed 3T3-L1 preadipocyte differentiation and adipogenesis. Mechanistically, PAR2 promoted 3T3-L1 preadipocyte differentiation and TG production through activation of the PI3K/AKT signalling pathway and MAT2A gene expression. The research sheds light on the adipogenic effects of PAR2 and its underlying mechanisms. Thus, PAR2 may have therapeutic significance for obesity.

Relative expression of KLK5 to LEKTI is associated with aggressiveness of oral squamous cell carcinoma

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Approximately 650,000 people will be diagnosed this year with cancers of the oral cavity and pharynx worldwide.

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The absence of biomarkers for the disease early detection contributes to the late diagnosis.

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Despite some advances with regards to treatment, overall survival has not significantly improved in decades.

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We have shown that increased relative mRNA expression of KLK5 to LEKTI is associated with disease’s poor outcome.

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This work supports the relative expression of KLK5 to LEKTI as a valuable prognostic marker.

Background

Oral squamous cell carcinoma (OSCC) remains a challenging cancer to treat despite all the advances of the last 50 years. Kallikrein 5 (KLK5) is among the serine proteases implicated in OSCC development. However, whether the activity of KLK5 promotes carcinogenesis is still controversial. Moreover, knowledge regarding the role of the KLK5 cognate inhibitor, Lympho-Epithelial Kazal-Type related Inhibitor (LEKTI), in OSCC is scarce. We have, thus, sought to investigate the importance of KLK5 and LEKTI expression in premalignant and malignant lesions of the oral cavity.

Methods

KLK5 and LEKTI protein expression was evaluated in 301 human samples, which were comprised of non-malignant and malignant lesions of the oral cavity. Moreover, a bioinformatic analysis of the overall survival rate from 517 head and neck squamous cell carcinoma (HNSCC) samples was performed. Additionally, to mimic the uncovered KLK5 to serine peptidase inhibitor (SPINK5) imbalance, the KLK5 gene was abrogated in an OSCC cell line using CRISPR-Cas9 technology. The generated cell line was then used for in vivo and in vitro carcinogenesis related experiments.

Results

LEKTI was found to be statistically downregulated in OSCCs, with increased KLK5/SPINK5 mRNA ratio being associated with a shorter overall survival (p = 0.091). Indeed, disruption of KLK5 to SPINK5 balance through the generation of KLK5 null OSCC cells led to smaller xenografted tumors and statistically decreased proliferation rates following multiple time points of BrdU treatment in vitro.

Conclusion

The association of increased enzyme/inhibitor ratio with poor prognosis indicates KLK5 to SPINK5 relative expression as an important prognostic marker in OSCC.

Long noncoding RNA HEIH depletion depresses esophageal carcinoma cell progression by upregulating microRNA-185 and downregulating KLK5

Numerous studies have reported the association of long non-coding RNAs (lncRNAs) in cancers, yet the function of lncRNA high expressed in hepatocellular carcinoma (HEIH) in esophageal carcinoma (EC) has seldom been explored. Here, we aimed to explore the mechanism of HEIH on EC via microRNA-185 (miR-185)/kallikrein-related peptidase 5 (KLK5) modulation. Cancer and non-tumoral tissues were collected, in which HEIH, miR-185 and KLK5 expression were detected, as well as their correlations. Also, the relation between the prognosis of EC patients and HEIH/miR-185/KLK5 expression was clarified. EC cells (KYSE-30 and TE-1) were screened for subsequent gain- and loss-of-function assays and their biological functions were further monitored. Tumor volume and weight in EC mice were also measured. Results from this study indicated that HEIH and KLK5 were elevated and miR-185 was declined in EC. The positive correlation was seen in HEIH and KLK5 expression, while the negative correlation was observed in HEIH or KLK5 and miR-185 expression. High HEIH and KLK5 indicated worse prognosis and high miR-185 suggested better prognosis of EC patients. Depleting HEIH or restoring miR-185 suppressed the malignant phenotypes of EC cells, and delayed tumor growth in EC mice. HEIH was found to bind with miR-185 to regulate KLK5 expression. Overexpressing KLK5 alone promoted EC cell progression while up-regulating miR-185 reversed such effects on EC cells. Collectively, we reveal that HEIH depletion dampens EC progression by upregulating miR-185 and downregulating KLK5, which provides novel treatments for EC.

Protease-activated receptor-2 accelerates intestinal tumor formation through activation of nuclear factor-κB signaling and tumor angiogenesis in ApcMin/+ mice

Hepatocyte growth factor activator inhibitor‐1 (HAI‐1), encoded by the SPINT1 gene, is a membrane‐bound protease inhibitor expressed on the surface of epithelial cells. Hepatocyte growth factor activator inhibitor‐1 regulates type II transmembrane serine proteases that activate protease‐activated receptor‐2 (PAR‐2). We previously reported that deletion of Spint1 in Apc^Min/+ mice resulted in accelerated formation of intestinal tumors, possibly through enhanced nuclear factor‐κB signaling. In this study, we examined the role of PAR‐2 in accelerating tumor formation in the Apc^Min/+ model in the presence or absence of Spint1. We observed that knockout of the F2rl1 gene, encoding PAR‐2, not only eliminated the enhanced formation of intestinal tumors caused by Spint1 deletion, but also reduced tumor formation in the presence of Spint1. Exacerbation of anemia and weight loss associated with HAI‐1 deficiency was also normalized by compound deficiency of PAR‐2. Mechanistically, signaling triggered by deregulated protease activities increased nuclear translocation of RelA/p65, vascular endothelial growth factor expression, and vascular density in Apc^Min/+‐induced intestinal tumors. These results suggest that serine proteases promote intestinal carcinogenesis through activation of PAR‐2, and that HAI‐1 plays a critical tumor suppressor role as an inhibitor of matriptase, kallikreins, and other PAR‐2 activating proteases.

Kallikrein-related Peptidase 5 (KLK5) Expression and Distribution in Canine Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (cSCC) is one of the most common types of malignant skin cancer in dogs, representing 3.9-10.4% of all canine skin tumours. Although the metastatic potential of cSCC is debated, it appears to mimic that observed in man. In man, predictive histopathological features for metastasis include tumour depth, lesions >5-6 mm in depth, and invasion of muscle, cartilage or bone. In dogs, some reports have focused on the clinical features and long-term progression of cSCC, but a gold standard treatment has not yet been developed. We explored the protein expression of kallikrein-related peptidase 5 (KLK5), an important modulator of skin homeostasis, in normal canine skin and in examples of cSCC. KLK5 was highly expressed in the upper stratum granulosum, stratum corneum, hair follicles and sweat glands, skin sites where human KLK5 has been shown to be involved in physiological processes including keratinocyte desquamation, antimicrobial defence, lipid permeability and pigmentation. In cSCC, tumour cells at the deep margin, as well as those in the centre of keratin pearls, displayed cytoplasmic expression of KLK5. Some of the KLK5 immunoreactive cells also expressed vimentin, suggesting that they may be undergoing epithelial-mesenchymal transition and therefore have a more invasive behaviour than those expressing only KLK5. KLK5 may be a novel molecular biomarker useful for predicting prognosis of cSSC in dogs.

Tissue kallikrein-related peptidase8 protects rat heart against acute ischemia reperfusion injury

Tissue kallikrein-related peptidases (KLKs) play important roles in acute cardiac injury and cardiac remodeling. However, the exact cardiac actions of KLK8 have not been determined. Transgenic rat overexpressing KLK8 was established to examine the role of KLK8 in the heart. Cardiac injury was induced by ischemia/reperfusion (I/R) and examined by infarct size measurement and TUNEL staining. The molecular mechanisms were investigated in cultured neonatal rat cardiomyocytes (CMs). Western blot analysis was used to determine the protein levels. KLK8 protein level was significantly increased in the cardiac ischemic risk area. KLK8 overexpression mitigated I/R-induced cardiac injury, as evidenced by decreased infarct size and apoptosis in cardiac ischemic risk area in vivo. Via in vitro studies, it was found that KLK8 overexpression attenuated the Hypoxia/Reoxygenation (H/R) injury in CMs; both B2R and PAR2 antagonist significantly attenuated KLK8-induced protective actions under H/R injury. Moreover, KLK8 overexpressed CMs showed significant higher phosphorylation levels of Akt, ERK1/2 and PKA under H/R stimulation; B2R antagonist attenuated the phosphorylation levels of Akt and ERK1/2, while PAR2 antagonist attenuated the phosphorylation levels of PKA and ERK1/2. KLK8 protects the heart against I/R-induced cardiac injury, which may represent a new therapeutic target in cardiac medicine.

Uncovering the clinical impact of kallikrein-related peptidase 5 (KLK5) mRNA expression in the colorectal adenoma-carcinoma sequence

Background Kallikrein-related peptidases (KLKs) are a subgroup of serine proteases located on chromosome 19q13.3. Most KLKs have been extensively studied as potential biomarkers for several carcinomas and other diseases. KLK5 was originally identified from a keratinocyte library, and its enzyme was purified from the stratum corneum of human skin. KLK5 was shown to be differentially expressed in a variety of endocrine tumors, although it is not as yet examined widely in colorectal cancer (CRC). Methods In this study, we quantitatively assessed the mRNA expression status of KLK5 in 197 colorectal tissues from 133 patients (70 cancerous and their paired normal colonic mucosa for 64 of them, as well as 63 colorectal adenomas) by quantitative real-time PCR (qPCR) using TaqMan probes. Statistical analysis evaluated the results. Results It was shown that KLK5 expression is reduced following the histologically non-cancerous-adenoma sequence (p<0.001), whereas it is increased during the sequence adenoma-carcinoma (p<0.001). Furthermore, KLK5 positive expression is associated with positive nodal status (p=0.022), advanced tumor stage (p=0.038) and high histological grade (p=0.033). Cox univariate analysis revealed that KLK5 positive expression is associated with disease-free survival (DFS) (p=0.028) and overall survival (OS) of patients (p=0.048). Kaplan-Meyer survival models showed that patients with positive KLK5 expression have lower DFS (p=0.009) and OS (p=0.019). Receiver operating characteristic (ROC) analysis demonstrated for first time that KLK5 expression had significant discriminatory values between cancer and adenoma tissues (area under the curve [AUC] 0.77; 95% confidence interval [CI]=0.69-0.85, p=0.03). Conclusions KLK5 mRNA expression may be useful for the differentiation of CRC from colorectal adenoma and represents a potential unfavorable prognostic biomarker for CRC.

PAR-2 promotes cell proliferation, migration, and invasion through activating PI3K/AKT signaling pathway in oral squamous cell carcinoma

Objective: This research aimed to explore the function of protease activated receptor 2 (PAR-2) in oral squamous cell carcinoma (OSCC) development and progression, as well as underlying molecular mechanism.

Methods: Tissue samples were collected from 115 OSCC patients. Quantitative real-time PCR (qRT-PCR) was performed to measure the expression of PAR-2 mRNA in OSCC tissues and cells. MTT and Transwell assays were used to detect the proliferation, migration, and invasion of OSCC cells, respectively. Western blot was performed to determine protein expression.

Results: The expression of PAR-2 mRNA was up-regulated in OSCC tissue and cells (P<0.01), and its mRNA level was obviously correlated to tumor differentiation and TNM stage in OSCC (P<0.05 for both). The activation of PAR-2 with PAR-2AP (PAR-2 agonist) significantly promoted the proliferation, migration, and invasion of OSCC cells, while its knockout could inhibit malignant behaviors of OSCC cells (P<0.05). Excessive activation of PAR-2 enhanced phosphorylation level of PI3K, AKT, and mTOR revealing the activation of PI3K/AKT pathway. Moreover, LY294002, the inhibitor of PI3K/AKT pathway, could reverse oncogenic action caused by PAR-2 activation.

Conclusion:PAR-2 can promote OSCC growth and progression via activating PI3K/AKT signaling pathway.

Kallikrein-related peptidases in lung diseases

Human tissue kallikreins (KLKs) are 15 members of the serine protease family and are present in various healthy human tissues including airway tissues. Multiple studies have revealed their crucial role in the pathophysiology of a number of chronic, infectious and tumour lung diseases. KLK1, 3 and 14 are involved in asthma pathogenesis, and KLK1 could be also associated with the exacerbation of this inflammatory disease caused by rhinovirus. KLK5 was demonstrated as an influenza virus activating protease in humans, and KLK1 and 12 could also be involved in the activation and spread of these viruses. KLKs are associated with lung cancer, with up- or downregulation of expression depending on the KLK, cancer subtype, stage of tumour and also the microenvironment. Functional studies showed that KLK12 is a potent pro-angiogenic factor. Moreover, KLK6 promotes malignant-cell proliferation and KLK13 invasiveness. In contrast, KLK8 and KLK10 reduce proliferation and invasion of malignant cells. Considering the involvement of KLKs in various physiological and pathological processes, KLKs appear to be potential biomarkers and therapeutic targets for lung diseases.

PRSS21/testisin inhibits ovarian tumor metastasis and antagonizes proangiogenic angiopoietins ANG2 and ANGPTL4

Ovarian cancer is the leading cause of death among all the gynecological cancers in the USA. Ovarian cancer employs a unique mode of metastasis, as exfoliated tumor cells disseminate within the peritoneal cavity, colonizing in several sites as well as accumulating ascites. Tumor recurrence and widespread metastasis are significant factors contributing to poor prognosis. PRSS21 is a metastasis-associated ovarian cancer gene that encodes the glycosyl-phosphatidylinositol-linked serine protease, testisin. Testisin expression is increased in multiple ovarian tumor types, with relatively little expression in normal tissues, but is differentially decreased in metastatic ovarian serous carcinomas compared to primary tumors. Here we explored the function of testisin in late-stage ovarian cancer progression using a murine xenograft model of ovarian intraperitoneal tumor metastasis. Increased tumor testisin expression inhibited intra-peritoneal tumor seeding and colonization, ascites accumulation, and metastatic tumor burden that was dependent on catalytically active testisin. The known testisin substrate, protease-activated receptor-2 (PAR-2), is a target of testisin activity. Gene profiling and mechanistic studies demonstrate that testisin activity suppresses the synthesis and secretion of pro-angiogenic angiopoietins, ANG2 and ANGPTL4, which normally promote vascular leak and edema. These observations support a model wherein testisin activates PAR-2 to antagonize proangiogenic angiopoietins that modulate vascular permeability and ascites accumulation associated with ovarian tumor metastasis. KEY MESSAGES: Testisin inhibits metastatic ovarian tumor burden and ascites production. Testisin activity antagonizes ANG2 and ANGPTL4 synthesis and secretion. PAR-2 is a proteolytic target of testisin on the surface of ovarian cancer cells.

Epidermal Lipids: Key Mediators of Atopic Dermatitis Pathogenesis

The skin barrier keeps the 'inside in' and the 'outside out', forming a protective blanket against external insults. Epidermal lipids, such as ceramides, fatty acids (FAs), triglycerides, and cholesterol, are integral components driving the formation and maintenance of the epidermal permeability barrier (EPB). A breach in this lipid barrier sets the platform for the subsequent onset and progression of atopic dermatitis (AD). Such lipids are also important in the normal functioning of organisms, both plants and animals, and in diseases, including cancer. Given the doubling of the number of cases of AD in recent years and the chronic nature of this disorder, here we shed light on the multifaceted role of diverse types of lipid in mediating AD pathogenesis.

Mucoadhesive Polymeric Films to Enhance Barbaloin Penetration Into Buccal Mucosa: a Novel Approach to Chemoprevention

Nowadays, chemoprevention by administering natural supplements is considered an attractive strategy to reverse, suppress, or prevent the evolution of premalignant oral lesions. In particular, Barbaloin exhibits anti-proliferative, anti-inflammatory, and anti-cancer properties, and it results useful in multi-therapy with classic chemotherapeutics. Therefore, in this work, mucoadhesive buccal films, as locoregional drug delivery system able to provide a targeted and efficient therapeutic delivery of Barbaloin, are proposed. Thus, Aloin extract-loaded Eudragit® RL100 or Eudragit® RS100-based buccal films were designed in order to obtain an easily self-administrable formulation capable of promoting Barbaloin penetration into buccal mucosa and assuring high patient compliance. Large amounts of extract (44%) were loaded into the polymer matrix and six formulations were prepared varying polymers and plasticizers ratios. For all formulations, physical form (thermogravimetric analysis-differential scanning calorimetry, TGA-DSC), swelling degree, mucoadhesiveness, drug release, and ability to promote drug penetration in mucosa have been investigated. After a sequential selection process, Eudragit RS 100-based film, with low PVP and high plasticizers amounts, emerged as the most promising. It results appropriately flexible, uniform in terms of weight, thickness and drug content, as well as characterized by suitable surface pH, good mucoadhesiveness, and low swelling degree. It displays a Higuchian drug release behavior up to 89% of Barbaloin released, thus demonstrating that diffusion through the matrix is the main release mechanism. Remarkable penetration enhancer properties of film were demonstrated by evidence of Barbaloin accumulation into buccal mucosa up to 10-fold higher than those obtained following administration of Aloin solution.

Proteases: Pivot Points in Functional Proteomics

Proteases drive the life cycle of all proteins, ensuring the transportation and activation of newly minted, would-be proteins into their functional form while recycling spent or unneeded proteins. Far from their image as engines of protein digestion, proteases play fundamental roles in basic physiology and regulation at multiple levels of systems biology. Proteases are intimately associated with disease and modulation of proteolytic activity is the presumed target for successful therapeutics. "Proteases: Pivot Points in Functional Proteomics" examines the crucial roles of proteolysis across a wide range of physiological processes and diseases. The existing and potential impacts of proteolysis-related activity on drug and biomarker development are presented in detail. All told the decisive roles of proteases in four major categories comprising 23 separate subcategories are addressed. Within this construct, 15 sets of subject-specific, tabulated data are presented that include identification of proteases, protease inhibitors, substrates, and their actions. Said data are derived from and confirmed by over 300 references. Cross comparison of datasets indicates that proteases, their inhibitors/promoters and substrates intersect over a range of physiological processes and diseases, both chronic and pathogenic. Indeed, "Proteases: Pivot Points …" closes by dramatizing this very point through association of (pro)Thrombin and Fibrin(ogen) with: hemostasis, innate immunity, cardiovascular and metabolic disease, cancer, neurodegeneration, and bacterial self-defense.

PAR2 promotes M1 macrophage polarization and inflammation via FOXO1 pathway

Macrophages polarization plays essential but different roles in most diseases such as atherosclerosis, adipose tissue inflammation, and insulin resistance. Our previous study revealed that protease-activated receptor 2 (PAR2), a G-protein coupled receptor influenced macrophage function, but little is known regarding the regulation of macrophage polarization process and its potential mechanisms. In the present study, bone marrow-derived macrophages (BMDM) isolated from C57/BL6 mice and cultured with L929-conditional medium and murine macrophage cell line RAW264.7 were used to study the function of PAR2 activation in vitro. BMDM was stimulated by the small molecular PAR2 agonist, 2-furoyl-LIGRLO-amide trifluoroacetate salt, followed by transcription factor microarray to screen the significantly activated signaling pathways under PAR2 activation. Western blot analysis, quantitative real-time polymerase chain reaction (qRT-PCR) was used to evaluate the expression of targeted genes and transcription factors. Immunofluorescence was used to observe the subcellular distribution of transcription factors. Our results demonstrated that M1-like polarization was presented by PAR2 agonist treatment with significant upregulation of interleukin-1β, interleukin-6, monocyte chemotactic protein-1, and tumor necrosis factor-α in BMDM and RAW264.7. Microarray identified forkhead box protein O1 (FOXO1) was significantly increased under PAR2 agonist stimulation, which was confirmed by qPCR and Western blot analysis. Immunofluorescence demonstrated that increased FOXO1 accumulated in the nucleus, which is necessary to promote transcription for targeted genes. We further knocked down FOXO1 expression using small interfering RNA, which alleviated PAR2-induced proinflammatory gene expression. The PAR2/FOXO1 pathway mediated stimulation of proinflammatory genes was further confirmed by tryptase, an endogenous ligand of PAR2. In conclusion, this study demonstrated that PAR2 activation-induced M1 polarization and inflammation through the FOXO1-dependent pathway.

KLK5, a novel potential suppressor of vaginal carcinogenesis

Vaginal cancer is rare and largely unexplored. We found here that kallikrein-related peptidase 5 (KLK5) is coordinately expressed along with other KLKs in all stratified epithelia, including vagina, pointing to potential role(s) in differentiation. Further, we propose that KLK5 could be implicated in vaginal cancer development based on the fact that Klk5-/- mice are prone to develop vaginal tumors when exposed to 7,12-dimethylbenz[a]anthracene. Nf-κb activation is markedly enhanced in Klk5-/-, leading to increased resistance to apoptosis of mutated vaginal cells. This explains the higher tumor numbers observed in Klk5-/- compared to wildtype. Thus, KLK5 may represent a putative suppressor of vaginal cancer.

Assessment of cellular and serum proteome from tongue squamous cell carcinoma patient lacking addictive proclivities for tobacco, betel nut, and alcohol: Case study

The intriguing molecular pathways involved in oral carcinogenesis are still ambiguous. The oral squamous cell carcinoma (OSCC) ranks as the most common type constituting more than 90% of the globally diagnosed oral cancers cases. The elevation in the OSCC incidence rate during past 10 years has an alarming impression on human healthcare. The major challenges associated with OSCC include delayed diagnosis, high metastatic rates, and low 5-year survival rates. The present work foundations on reverse genetic strategy and involves the identification of genes showing expressional variability in an OSCC case lacking addictive proclivities for tobacco, betel nut, and/or alcohol, major etiologies. The expression modulations in the identified genes were analyzed in 16 patients comprising oral pre-cancer and cancer histo-pathologies. The genes SCCA1 and KRT1 were found to down regulate while DNAJC13, GIPC2, MRPL17, IG-Vreg, SSFA2, and UPF0415 upregulated in the oral pre-cancer and cancer pathologies, implicating the genes as crucial players in oral carcinogenesis.

DNA methylation directly downregulates human cathelicidin antimicrobial peptide gene (CAMP) promoter activity

LL-37, the active product of human cathelicidin antimicrobial peptide (CAMP) has a broad spectrum of antibacterial activity. LL-37 also has important physiological functions in immune regulation, angiogenesis and in modulating apoptosis. The roles of LL-37 in oral squamous cell carcinoma (OSCC) are still not clear. The correlation between DNA methylation and human CAMP expression is also unknown. Here human CAMP/LL-37 expression was assessed by immunohistochemistry in normal and OSCC tissues. The results indicated that low expression of CAMP/LL-37 correlated with histological differentiation and lymph node metastasis and also promoted tumor progression. A cell-specific methylation pattern in the promoter region of human CAMP was detected. Treatment with 5-aza-2'-deoxycytidine, a DNA demethylation reagent can increase human CAMP expression in epithelial cancer cells. The reporter assay showed that unmethylated human CAMP promoter activity was significantly higher than methylated promoter activity. Taken together, these results suggested that human CAMP/LL-37 might act as a tumor-suppressor in OSCC and DNA methylation might play roles during carcinogenesis via directly downregulating human CAMP promoter activity.

Inhibition of nuclear factor-κB signaling suppresses Spint1-deletion-induced tumor susceptibility in the ApcMin/+ model

Hepatocyte growth factor activator inhibitor type 1 (HAI-1), encoded by the Spint1 gene, is a membrane-bound serine protease inhibitor expressed on the epithelial cell surface. We have previously reported that the intestine-specific Spint1-deleted ApcMin/+ mice showed accelerated formation of intestinal tumors. In this study, we focused on the role of nuclear factor-κB (NF-κB) signaling in the HAI-1 loss-induced tumor susceptibility. In the HAI-1-deficient intestine, inflammatory cytokines, such as tumor necrosis factor-α and interleukin-6, were upregulated in normal mucosa. Furthermore, increased nuclear translocation of NF-κB was observed in both normal mucosa and tumor tissues of HAI-1-deficient ApcMin/+ intestines, and an NF-κB target gene, such as urokinase-type plasminogen activator, was upregulated in the HAI-1-deficient tumor tissues. Thus, we investigated the effect of dehydroxymethylepoxyquinomicin (DHMEQ), a synthetic inhibitor of NF-κB, on intestinal HAI-1-deficient ApcMin/+ mice. Treatment with DHMEQ reduced the formation of intestinal tumors compared with vehicle control in the HAI-1-deficient ApcMin/+ mice. These results suggested that insufficient HAI-1 function promotes intestinal carcinogenesis by activating NF-κB signaling.

MicroRNA-196a-5p is a potential prognostic marker of delayed lymph node metastasis in early-stage tongue squamous cell carcinoma

MicroRNAs (miRs) are expected to serve as prognostic tools for cancer. However, many miRs have been reported as prognostic markers of recurrence or metastasis in oral squamous cell carcinoma patients. We aimed to determine the prognostic markers in early-stage tongue squamous cell carcinoma (TSCC). Based on previous studies, we hypothesized that miR-10a, 10b, 196a-5p, 196a-3p, and 196b were prognostic markers and we retrospectively performed miR expression analyses using formalin-fixed paraffin-embedded sections of surgical specimens. Total RNA was isolated from cancer tissues and adjacent normal tissue as control, and samples were collected by laser-capture microdissection. After cDNA synthesis, reverse transcription-quantitative polymerase chain reaction was performed. Statistical analyses for patient clinicopathological characteristics, recurrence/metastasis, and survival rates were performed to discern their relationships with miR expression levels, and the 2^−ΔΔCq method was used. miR-196a-5p levels were significantly upregulated in early-stage TSCC, particularly in the lymph node metastasis (LNM) group. The LNM-free survival rate in the low miR-196a-5p ΔΔCq value regulation group was found to be lower than that in the high ΔΔCq value regulation group (P=0.0079). Receiver operating characteristic analysis of ΔΔCq values revealed that miR-196a-5p had a P-value=0.0025, area under the curve=0.740, and a cut-off value=−0.875 for distinguishing LNM. To our knowledge, this is the first study to examine LNM-related miRs in early-stage TSCC as well as miRs and ‘delayed LNM’ in head and neck cancer. miR-196a-5p upregulation may predict delayed LNM. Our data serve as a foundation for future studies to evaluate miR levels and facilitate the prediction of delayed LNM during early-stage TSCC, which prevent metastasis when combined with close follow-up and aggressive adjuvant therapy or elective neck dissection. Moreover, our data will serve as a foundation for future studies to evaluate whether miR-196a-5p can serve as a therapeutic marker for preventing metastasis.

miR-200c-3p spreads invasive capacity in human oral squamous cell carcinoma microenvironment

Oral squamous cell carcinoma (OSCC) constitutes over 90% of all cancers in the oral cavity. The prognosis for patients with invasive OSCC is poor; therefore, it is important to understand the molecular mechanisms of invasion and subsequent metastasis not only to prevent cancer progression but also to detect new therapeutic targets against OSCC. Recently, extracellular vesicles-particularly exosomes-have been recognized as intercellular communicators in the tumor microenvironment. As exosomic cargo, deregulated microRNAs (miRNAs) can shape the surrounding microenvironment in a cancer-dependent manner. Previous studies have shown inconsistent results regarding miR-200c-3p expression levels in OSCC cell lines, tissues, or serum-likely because of the heterogeneous characters of the specimen materials. For this reason, single-cell clone analyses are necessary to effectively assess the role of exosome-derived miRNAs on cells within the tumor microenvironment. The present study utilized integrated microarray profiling to compare exosome-derived miRNA and exosome-treated cell-derived mRNA expression. Data were acquired from noninvasive SQUU-A and highly invasive SQUU-B tongue cancer cell clones derived from a single patient to determine candidate miRNAs that promote OSCC invasion. Matrigel invasion assays confirmed that hsa-miR-200c-3p was a key pro-invasion factor among six miRNA candidates. Consistently, silencing of the miR-200c-3p targets, CHD9 and WRN, significantly accelerated the invasive potential of SQUU-A cells. Thus, our data indicate that miR-200c-3p in exosomes derived from a highly invasive OSCC line can induce a similar phenotype in non-invasive counterparts.

Deregulated matriptase activity in oral squamous cell carcinoma promotes the infiltration of cancer-associated fibroblasts by paracrine activation of protease-activated receptor 2

Cancer-associated fibroblasts (CAFs) are known to contribute to cancer progression. We have reported that cell surface expression of hepatocyte growth factor activator inhibitor 1 (HAI-1) is decreased in invasive oral squamous cell carcinoma (OSCC) cells. This study examined if HAI-1-insufficiency contributes to CAF recruitment in OSCC. Serum-free conditioned medium (SFCM) from a human OSCC line (SAS) stimulated the migration of 3 human fibroblast cell lines, NB1RGB, MRC5 and KD. SFCM from HAI-1-knockdown SAS showed an additive effect on the migration of NB1RGB and MRC5, but not KD. SAS SFCM induced protease-activated receptor-2 (PAR-2) expression in NB1RGB and MRC5, but not in KD, and a PAR-2 antagonist blocked the stimulatory effect of HAI-1 knockdown on migration of the PAR-2 expressing cell lines. Moreover, HAI-1-deficient SFCM showed additive stimulatory effects on the migration of wild-type but not PAR-2-deficient mouse fibroblasts. Therefore, the enhanced migration induced by HAI-1-insufficiency was mediated by PAR-2 activation in fibroblasts. This activation resulted from the deregulation of the activity of matriptase, a PAR-2 agonist protease. HAI-1 may thus prevent CAF recruitment to OSCC by controlling matriptase activity. When HAI-1 expression is reduced on OSCC, matriptase may contribute to CAF accumulation by paracrine activation of fibroblast PAR-2. Immunohistochemical analysis of resected OSCC revealed increased PAR2-positive CAFs in 35% (33/95) of the cases studied. The increased PAR-2 positive CAFs tended to correlate with infiltrative histology of the invasion front and shorter disease-free survival of the patients.

Protease-Activated Receptors and other G-Protein-Coupled Receptors: the Melanoma Connection

The vast array of G-protein-coupled receptors (GPCRs) play crucial roles in both physiological and pathological processes, including vision, coagulation, inflammation, autophagy, and cell proliferation. GPCRs also affect processes that augment cell proliferation and metastases in many cancers including melanoma. Melanoma is the deadliest form of skin cancer, yet limited therapeutic modalities are available to patients with metastatic melanoma. Studies have found that both chemokine receptors and protease-activated receptors, both of which are GPCRs, are central to the metastatic melanoma phenotype and may serve as potential targets in novel therapies against melanoma and other cancers.