Eldecalcitol (ED-71)-induced exosomal miR-6887-5p suppresses squamous cell carcinoma cell growth by targeting heparin-binding protein 17/fibroblast growth factor-binding protein-1 (HBp17/FGFBP-1)

Clinical significance and biological role of claudin-1 in oral squamous cell carcinoma cells

OBJECTIVES

Claudin (CLD), a major component of tight junctions, is a four-transmembrane protein, and 24 subtypes have been reported in humans. CLD expression is highly tissue-specific; CLD1 has been reported to be expressed in the skin and mucosa. There have been few reports on CLD1 expression and its function in oral cancer.

MATERIALS AND METHODS

This retrospective study immunohistochemically evaluated CLD1 expression as prognostic predictors in 84 participants with oral squamous cell carcinoma (OSCC). Participants were classified as positive or negative based on staining intensity; the clinicopathologic characteristics and survival rates of the two groups were compared. To clarify the biological role of CLD1 in OSCC cells, we examined the effects of CLD1 overexpression on the invasion and proliferation of the OSCC cell line, SCCKN.

RESULTS

We observed the immunohistochemical CLD1 expression in the cell membranes of OSCC cells. The disease-free survival rate was significantly lower in patients with CLD1-positive OSCC than in patients with CLD1-negative OSCC (P < .05). In vitro studies showed that cell proliferative capacity, motility, proteolytic activity, and invasive growth were promoted in CLD1-overexpressing SCCKN cells compared to those in control SCCKN cells.

CONCLUSION

CLD1 may be a useful and potential prognostic factor for OSCC treatment.

Potential treatment of squamous cell carcinoma by targeting heparin-binding protein 17/fibroblast growth factor-binding protein 1 with vitamin D3 or eldecalcitol

Heparin-binding protein 17 (HBp17), first purified in 1991 from the conditioned medium of the human A431 squamous cell carcinoma (SCC) cell line, was later renamed fibroblast growth factor-binding protein 1 (FGFBP-1). HBp17/FGFBP-1 is specifically expressed and secreted by epithelial cells, and it reversibly binds to fibroblast growth factor (FGF)-1 and FGF-2, as well as FGFs-7, -10, and -22, indicating a crucial involvement in the transportation and function of these FGFs. Our laboratory has investigated and reported several studies to elucidate the function of HBp17/FGFBP-1 in SCC cells and its potential as a molecular therapeutic target. HBp17/FGFBP-1 transgene exoression in A431-4 cells, a clonal subline of A431 that lacks tumorigenicity and does not express HBp17/FGFBP-1, demonstrated a significantly enhanced proliferation in vitro compared with A431-4 cells, and it acquired tumorigenicity in the subcutis of nude mice. Knockout (KO) of the HBp17/FGFBP-1 by genome editing significantly suppressed tumor growth, cell motility, and tumorigenicity compared with control cells. A comprehensive analysis of expressed molecules in both cell types revealed that molecules that promote epithelial cell differentiation were highly expressed in HBp17/FGFBP-1 KO cells. Additionally, we reported that 1α,25(OH)2D3 or eldecalcitol (ED-71), which is an analog of 1α,25(OH)2D3, suppresses HBp17/FGFBP-1 expression and tumor growth in vitro and in vivo by inhibiting the nuclear factor kappa-light-chain-enhancer of activated B cells signaling pathway. Here, we discuss the prospects of molecular targeted therapy targeting HBp17/FGFBP-1 with 1α,25(OH)2D3 or ED71 in SCC and oral SCC.

Clinical significance of integrin αV and β superfamily members and focal adhesion kinase activity in oral squamous cell carcinoma: a retrospective observational study

Objectives: Integrins are heterodimeric transmembrane plasma membrane proteins composed of α- and β-chains. They bind to extracellular matrix (ECM) and cytoskeletal proteins as ECM protein receptors. Upon ECM protein binding, integrins activate focal adhesion kinase (FAK) and transduce various signals. Despite their importance, integrin and FAK expression in oral squamous cell carcinoma (OSCC) tissue and the prognosis of patients with OSCC remains elusive. Methods: In a retrospective observational study, we immunohistochemically evaluated integrin αV, β1, β3, β5, β6, FAK, and phosphorylated-FAK (pFAK) expressions as prognostic predictors in 96 patients with OSCC. Patients were classified as positive or negative based on staining intensity, and clinicopathologic characteristics and survival rates of the two groups were compared. The association between above integrin-related proteins and PD-1 or PD-L1 in OSCC tissues was investigated. Results: We observed immunohistochemical integrin αV, β1, β6, β8, and FAK expressions in the cell membrane and cytoplasm but not integrin β3 and β5 in the OSCC tissues. pFAK was expressed in the cytoplasm of OSCC cells. The overall survival rate significantly decreased in pFAK-positive OSCC patients compared to the negative group, and cervical lymph node metastasis significantly increased in integrin β8-positive patients with OSCC (p < 0.05). No association between integrin-related proteins and PD-1 or PD-L1 in OSCC tissues was observed. Conclusion: Our results indicate that pFAK and integrin β8 are prognostic factors for OSCC. Therefore, pFAK- and integrin β8-targeting new oral cancer diagnostic and therapeutic methods hold a promising potential.

Emerging roles of exosomes in oral diseases progression

Oral diseases, such as periodontitis, salivary gland diseases, and oral cancers, significantly challenge health conditions due to their detrimental effects on patient's digestive functions, pronunciation, and esthetic demands. Delayed diagnosis and non-targeted treatment profoundly influence patients' prognosis and quality of life. The exploration of innovative approaches for early detection and precise treatment represents a promising frontier in oral medicine. Exosomes, which are characterized as nanometer-sized extracellular vesicles, are secreted by virtually all types of cells. As the research continues, the complex roles of these intracellular-derived extracellular vesicles in biological processes have gradually unfolded. Exosomes have attracted attention as valuable diagnostic and therapeutic tools for their ability to transfer abundant biological cargos and their intricate involvement in multiple cellular functions. In this review, we provide an overview of the recent applications of exosomes within the field of oral diseases, focusing on inflammation-related bone diseases and oral squamous cell carcinomas. We characterize the exosome alterations and demonstrate their potential applications as biomarkers for early diagnosis, highlighting their roles as indicators in multiple oral diseases. We also summarize the promising applications of exosomes in targeted therapy and proposed future directions for the use of exosomes in clinical treatment.

Tumor-Infiltrating CD45RO+ Memory Cells Are Associated with Favorable Prognosis in Oral Squamous Cell Carcinoma Patients

BACKGROUND

Tumor-infiltrating lymphocytes (TILs) have been used to predict the prognosis of solid tumors. In this study, we investigated which molecules in TILs play a role in the prognosis of patients with oral squamous cell carcinoma (OSCC).

METHODS

In a retrospective case-control study, we immunohistochemically evaluated the expression of CD3, CD8, CD45RO, Granzyme B, and the major histocompatibility complex class I chain-related molecule A (MICA) of the histocompatibility complex as predictors of prognosis in 33 patients with OSCC. The patients were classified as TILs^High or TILs^Low according to the number of TILs for each molecule in the central tumor (CT) and invasive margin (IM). Furthermore, MICA expression scores were determined based on the intensity of the staining.

RESULTS

CD45RO⁺/TIL in the nonrecurrent group were significantly higher than those in the recurrent group in the CT and IM areas (p < 0.05). The disease-free survival/overall survival rate of the CD45RO⁺/TILs^Low group in the CT and IM areas and the Granzyme B⁺/TILs^Low group in the IM area was significantly lower than that of the CD45RO⁺/TILs^High group and the Granzyme B⁺/TILs^High group, respectively (p < 0.05). Furthermore, the MICA expression score of tumors around the CD45RO⁺/TILs^High group was significantly higher than that of the CD45RO⁺/TILs^Low group (p < 0.05).

CONCLUSIONS

A high ratio of CD45RO-expressing TILs was associated with a disease-free/overall survival improvement in OSCC patients. Furthermore, the number of TILs that express CD45RO was associated with the expression of MICA in tumors. These results suggest that CD45RO-expressing TILs are useful biomarkers for OSCC.

Modulating Effects of Cancer-Derived Exosomal miRNAs and Exosomal Processing by Natural Products

Cancer-derived exosomes exhibit sophisticated functions, such as proliferation, apoptosis, migration, resistance, and tumor microenvironment changes. Several clinical drugs modulate these exosome functions, but the impacts of natural products are not well understood. Exosome functions are regulated by exosome processing, such as secretion and assembly. The modulation of these exosome-processing genes can exert the anticancer and precancer effects of cancer-derived exosomes. This review focuses on the cancer-derived exosomal miRNAs that regulate exosome processing, acting on the natural-product-modulating cell functions of cancer cells. However, the role of exosomal processing has been overlooked in several studies of exosomal miRNAs and natural products. In this study, utilizing the bioinformatics database (miRDB), the exosome-processing genes of natural-product-modulated exosomal miRNAs were predicted. Consequently, several natural drugs that modulate exosome processing and exosomal miRNAs and regulate cancer cell functions are described here. This review sheds light on and improves our understanding of the modulating effects of exosomal miRNAs and their potential exosomal processing targets on anticancer treatments based on the use of natural products.

Nanomedicines in oral cancer: inspiration comes from extracellular vesicles and biomimetic nanoparticles

Oral cancer is a common life-threatening malignancy having high mortality and morbidity rates. During the treatment process, individuals unavoidably experience severe side effects. It is essential to develop safer and more effective strategies. Currently, extracellular vesicles (EVs) and biomimetic nanoparticles are nanomedicines with long-term blood circulation and lower off-target toxicity that orchestrate immune responses and accumulate specifically in tumor sites. EVs create a synergetic effect by encapsulating drugs and collaborating with naturally loaded elements in the EVs. Biomimetic nanoparticles retain the characteristic features of the synthetic nanocarriers and inherit the intrinsic cell membrane functionalities. This review outlines the properties, applications, challenges, pros and cons of EVs and biomimetic nanoparticles, providing novel perspectives on oral cancer.

New developments in the biology of fibroblast growth factors

The fibroblast growth factor (FGF) family is composed of 18 secreted signaling proteins consisting of canonical FGFs and endocrine FGFs that activate four receptor tyrosine kinases (FGFRs 1-4) and four intracellular proteins (intracellular FGFs or iFGFs) that primarily function to regulate the activity of voltage-gated sodium channels and other molecules. The canonical FGFs, endocrine FGFs, and iFGFs have been reviewed extensively by us and others. In this review, we briefly summarize past reviews and then focus on new developments in the FGF field since our last review in 2015. Some of the highlights in the past 6 years include the use of optogenetic tools, viral vectors, and inducible transgenes to experimentally modulate FGF signaling, the clinical use of small molecule FGFR inhibitors, an expanded understanding of endocrine FGF signaling, functions for FGF signaling in stem cell pluripotency and differentiation, roles for FGF signaling in tissue homeostasis and regeneration, a continuing elaboration of mechanisms of FGF signaling in development, and an expanding appreciation of roles for FGF signaling in neuropsychiatric diseases. This article is categorized under: Cardiovascular Diseases > Molecular and Cellular Physiology Neurological Diseases > Molecular and Cellular Physiology Congenital Diseases > Stem Cells and Development Cancer > Stem Cells and Development.

Current Status, Opportunities, and Challenges of Exosomes in Oral Cancer Diagnosis and Treatment

Oral cancer is one of the most common cancers in the world, with more than 300,000 cases diagnosed each year, of which oral squamous cell carcinoma accounts for more than 90%, with a 5-year survival rate of only 40–60%, and poor prognosis. Exploring new strategies for the early diagnosis and treatment of oral cancer is key to improving the survival rate. Exosomes are nanoscale lipid bilayer membrane vesicles that are secreted by almost all cell types. During the development of oral cancer, exosomes can transport their contents (DNA, RNA, proteins, etc) to target cells and promote or inhibit the proliferation, invasion, and metastasis of oral cancer cells by influencing the host immune response, drug-resistant metastasis, and tumour angiogenesis. Therefore, exosomes have great potential and advantages as biomarkers for oral cancer diagnosis, and as drug delivery vehicles or targets for oral cancer therapy. In this review, we first describe the biogenesis, biological functions, and isolation methods of exosomes, followed by their relationship with oral cancer. Here, we focused on the potential of exosomes as oral cancer biomarkers, drug carriers, and therapeutic targets. Finally, we provide an insightful discussion of the opportunities and challenges of exosome application in oral cancer diagnosis and treatment, intending to offer new ideas for the clinical management of oral cancer.

Vitamin D and Cancer: An Historical Overview of the Epidemiology and Mechanisms

This is a narrative review of the evidence supporting vitamin D's anticancer actions. The first section reviews the findings from ecological studies of cancer with respect to indices of solar radiation, which found a reduced risk of incidence and mortality for approximately 23 types of cancer. Meta-analyses of observational studies reported the inverse correlations of serum 25-hydroxyvitamin D [25(OH)D] with the incidence of 12 types of cancer. Case-control studies with a 25(OH)D concentration measured near the time of cancer diagnosis are stronger than nested case-control and cohort studies as long follow-up times reduce the correlations due to changes in 25(OH)D with time. There is no evidence that undiagnosed cancer reduces 25(OH)D concentrations unless the cancer is at a very advanced stage. Meta-analyses of cancer incidence with respect to dietary intake have had limited success due to the low amount of vitamin D in most diets. An analysis of 25(OH)D-cancer incidence rates suggests that achieving 80 ng/mL vs. 10 ng/mL would reduce cancer incidence rates by 70 ± 10%. Clinical trials have provided limited support for the UVB-vitamin D-cancer hypothesis due to poor design and execution. In recent decades, many experimental studies in cultured cells and animal models have described a wide range of anticancer effects of vitamin D compounds. This paper will review studies showing the inhibition of tumor cell proliferation, dedifferentiation, and invasion together with the sensitization to proapoptotic agents. Moreover, 1,25-(OH)2D3 and other vitamin D receptor agonists modulate the biology of several types of stromal cells such as fibroblasts, endothelial and immune cells in a way that interferes the apparition of metastases. In sum, the available mechanistic data support the global protective action of vitamin D against several important types of cancer.

Heparin-Binding Protein 17/Fibroblast Growth Factor-Binding Protein-1 Knockout Inhibits Proliferation and Induces Differentiation of Squamous Cell Carcinoma Cells

Simple Summary

Fibroblast growth factor (FGF) plays an important role in tumor growth by inducing angiogenesis in addition to promoting the proliferation of squamous cell carcinoma (SCC) and oral squamous cell carcinoma (OSCC) cells. Heparin-binding protein 17/fibroblast growth factor-binding protein-1 (HBp17/FGFBP-1) purified from A431 cell-conditioned media based on its capacity to bind to FGF-1 and FGF-2 is recognized as a pro-angiogenic molecule as a consequence of its interaction with FGF-2. In this study, we have examined the functional role of HBp17/FGFBP-1 in A431 and HO-1-N-1 cells using the CRISPR/Cas9 technology. Our results showed that HBp17/FGFBP-1 knockout inhibited cell proliferation, colony formation, and cell motility compared to control. The amount of FGF-2 was decreased in culture medium conditioned by HBp17/FGFBP-1 knockout cells compared to control. We performed cDNA/protein expression analysis followed by Gene Ontology and protein–protein interaction analysis. The results demonstrate that both gene and protein expression related to epidermal development, cornification, and keratinization were upregulated in HBp17/FGFBP-1-knockout A431 and HO-1-N-1 cells.

Abstract

Heparin-binding protein 17/fibroblast growth factor-binding protein-1 (HBp17/FGFBP-1) has been observed to induce the tumorigenic potential of epithelial cells and is highly expressed in oral cancer cell lines and tissues. It is also recognized as a pro-angiogenic molecule because of its interaction with fibroblast growth factor (FGF)-2. In this study, we examined the functional role of HBp17/FGFBP-1 in A431 and HO-1-N-1 cells. Originally, HBp17/FGFBP-1 was purified from A431 cell-conditioned media based on its capacity to bind to FGF-1 and FGF-2. We isolated and established HBp17/FGFBP-1-knockout (KO)-A431 and KO-HO-1-N-1 cell lines using the clusters of regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) gene editing technology. The amount of FGF-2 secreted into conditioned medium decreased for A431-HBp17-KO and HO-1-N-1-HBp17-KO cells compared to their WT counterparts. Functional assessment showed that HBp17/FGFBP-1 KO inhibited cell proliferation, colony formation, and cell motility in vitro. It also inhibited tumor growth in vivo compared to controls, which confirmed the significant difference in growth in vitro between HBp17-KO cells and wild-type (WT) cells, indicating that HBp17/FGFBP-1 is a potent therapeutic target in squamous cell carcinomas (SCC) and oral squamous cell carcinomas (OSCC). In addition, complementary DNA/protein expression analysis followed by Gene Ontology and protein–protein interaction (PPI) analysis using the Database for Visualization and Integrated Discovery and Search Tool for the Retrieval of Interacting Genes/Proteins showed that both gene and protein expression related to epidermal development, cornification, and keratinization were upregulated in A431-HBp17-KO and HO-1-N-1-KO cells. This is the first discovery of a novel role of HBp17/FGFBP-1 that regulates SCC and OSCC cell differentiation.

MicroRNAs and Long Non-Coding RNAs as Potential Candidates to Target Specific Motifs of SARS-CoV-2

The respiratory system is one of the most affected targets of SARS-CoV-2. Various therapies have been utilized to counter viral-induced inflammatory complications, with diverse success rates. Pending the distribution of an effective vaccine to the whole population and the achievement of "herd immunity", the discovery of novel specific therapies is to be considered a very important objective. Here, we report a computational study demonstrating the existence of target motifs in the SARS-CoV-2 genome suitable for specific binding with endogenous human micro and long non-coding RNAs (miRNAs and lncRNAs, respectively), which can, therefore, be considered a conceptual background for the development of miRNA-based drugs against COVID-19. The SARS-CoV-2 genome contains three motifs in the 5'UTR leader sequence recognized by selective nucleotides within the seed sequence of specific human miRNAs. The seed of 57 microRNAs contained a "GGG" motif that promoted leader sequence-recognition, primarily through offset-6mer sites able to promote microRNAs noncanonical binding to viral RNA. Similarly, lncRNA H19 binds to the 5'UTR of the viral genome and, more specifically, to the transcript of the viral gene Spike, which has a pivotal role in viral infection. Notably, some of the non-coding RNAs identified in our study as candidates for inhibiting SARS-CoV-2 gene expression have already been proposed against diverse viral infections, pulmonary arterial hypertension, and related diseases.

Exosomal cargoes in OSCC: current findings and potential functions

Oral squamous cell carcinoma (OSCC) is the most prevalent malignancy in head and neck cancer, with high recurrence and mortality. Early diagnosis and efficient therapeutic strategies are vital for the treatment of OSCC patients. Exosomes can be isolated from a broad range of different cell types, implicating them as important factors in the regulation of human physiological and pathological processes. Due to their abundant cargo including proteins, lipids, and nucleic acids, exosomes have played a valuable diagnostic and therapeutic role across multiple diseases, including cancer. In this review, we summarize recent findings concerning the content within and participation of exosomes relating to OSCC and their roles in tumorigenesis, proliferation, migration, invasion, metastasis, and chemoresistance. We conclude this review by looking ahead to their potential utility in providing new methods for treating OSCC to inspire further research in this field.

Inhibition of vitamin D analog eldecalcitol on hepatoma in vitro and in vivo

Hepatoma is a serious liver cancer with high morbidity and mortality. Eldecalcitol (ED-71), a vitamin D analog, is extensively used as anti-cancer agent in vitro. Hepatocellular carcinoma cell, SMMC-7721 cell lines were used in this study. Transwell assay, cell apoptosis and cell cycle detection assays were investigated after treatment with ED-71 and phosphate buffered saline (PBS) as control. Sizes of tumors were measured after ED-71 treatment in a mouse model. E-cadherin and Akt gene expressions were detected by real-time PCR (RT-PCR). The results showed that cell invasion and migration were decreased markedly after ED-71 treatment compared to control group. Cell cycle detection showed that the G2 stage was 13.18% and total S-stage was 41.16% in the ED-71 group and G2 stage: 22.88%, total S-stage: 27.34% in the control group. Cell apoptosis rate was promoted in the ED-71 group. Size of the tumors reduced more after the ED-71 treatment than the PBS treatment in mice. ED-71 markedly inhibited the expression of Akt and E-cadherin, either detected by immunohistochemistry or RT-PCR. ED-71 treatment can inhibit the hepatoma agent proliferation by increasing the E-cadherin expression and decreasing Akt expression. Therefore, these findings provide novel evidence that ED-71 can be used as an anti-hepatoma agent.

Emerging role of exosomes in craniofacial and dental applications

Exosomes, a specific subgroup of extracellular vesicles that are secreted by cells, have been recognized as important mediators of intercellular communication. They participate in a diverse range of physiological and pathological processes. Given the capability of exosomes to carry molecular cargos and transfer bioactive components, exosome-based disease diagnosis and therapeutics have been extensively studied over the past few decades. Herein, we highlight the emerging applications of exosomes as biomarkers and therapeutic agents in the craniofacial and dental field. Moreover, we discuss the current challenges and future perspectives of exosomes in clinical applications.