Effects of peritumoral bevacizumab injection against oral squamous cell carcinoma in a nude mouse xenograft model: A preliminary study

Tumor microenvironment dynamics in oral cancer: unveiling the role of inflammatory cytokines in a syngeneic mouse model

The process of cervical lymph node metastasis is dependent on the phenotype of the tumor cells and their interaction with the host microenvironment and immune system; conventional research methods that focus exclusively on tumor cells are limited in their ability to elucidate the metastatic mechanism. In cancer tissues, a specialized environment called the tumor microenvironment (TME) is established around tumor cells, and inflammation in the TME has been reported to be closely associated with the development and progression of many types of cancer and with the response to anticancer therapy. In this study, to elucidate the mechanism of metastasis establishment, including the TME, in the cervical lymph node metastasis of oral cancer, we established a mouse-derived oral squamous cell carcinoma cervical lymph node highly metastatic cell line and generated a syngeneic orthotopic transplantation mouse model. In the established highly metastatic cells, epithelial-mesenchymal transition (EMT) induction was enhanced compared to that in parental cells. In the syngeneic mouse model, lymph node metastasis was observed more frequently in tumors of highly metastatic cells than in parental cells, and Cyclooxygenase-2 (COX-2) expression and lymphatic vessels in primary tumor tissues were increased, suggesting that this model is highly useful. Moreover, in the established highly metastatic cells, EMT induction was enhanced compared to that in the parent cell line, and CCL5 and IL-6 secreted during inflammation further enhanced EMT induction in cancer cells. This suggests the possibility of a synergistic effect between EMT induction and inflammation. This model, which allows for the use of two types of cells with different metastatic and tumor growth potentials, is very useful for oral cancer research involving the interaction between cancer cells and the TME in tumor tissues and for further searching for new therapeutic agents.

Immunology of Oral Squamous Cell Carcinoma-A Comprehensive Insight with Recent Concepts

This review aims to understand the concept of oral cancer immunology through the notion of immune profiling, immunoediting and immunotherapy, and to gain knowledge regarding its application for the management of oral cancer patients. Oral cancer is an immunogenic tumor where the cells of the tumor microenvironment play an important role in tumorigenesis. Understanding the mechanism of these modulations can help design immunotherapeutic strategies in oral cancer patients. This article gives an overview of immunomodulation in the oral cancer tumor microenvironment, with concepts of immune profiling, immunoediting and immunotherapy. English literature searches via Google Scholar, Web of Science, EBSCO, Scopus, and PubMed database were performed with the key words immunology, tumor microenvironment, cells, cross talk, immune profiling, biomarkers, inflammation, gene expression, techniques, immunoediting, immunosurveillance, tumor escape, immunotherapy, immune checkpoint inhibitors, vaccines in cancer, oral cancer, and head and neck cancer. Original research articles, reviews, and case reports published from 2016-2021 (n = 81) were included to appraise different topics, and were discussed under the following subsections. Literature published on oral cancer immunology reveals that oral cancer immune profiling with appropriate markers and techniques and knowledge on immunoediting concepts can help design and play an effective role in immunotherapeutic management of oral cancer patients. An evaluation of oral cancer immunology helps to determine its role in tumorigenesis, and immunotherapy could be the emerging drift in the effective management of oral cancer.

The Correlation Between CD44 and Angiogenesis in Oral Squamous Cell Carcinoma Induced in Buccal Pouch in Syrian Hamster that Underwent Radiotherapy

BACKGROUND

Angiogenesis with radiotherapy is a significant focus of recent studies to confirm the importance of combined treatments, as vascular control can have a great therapeutic target. Vascular endothelial growth factor is the key mediator of angiogenesis in cancer. In addition, some studies suggest the value of CD44 as a potential early marker of angiogenesis.

OBJECTIVES

Investigating the expression of vascular endothelial growth factor (VEGF) and CD44 in oral squamous cell carcinoma (OSCC) after inducing it in hamsters then undergoing radiotherapy and comparing outcomes before and after therapy to verify changes of these markers.

MATERIALS & METHODS

an experimental study consisted of 18 samples of OSCC which induced in right buccal pouch of hamsters (group1) and 18 samples of OSCC which induced in the same way  and were exposed to radiation therapy (group2), Biopsies were taken and fixed with formalin, paraffin waxed in conventional H&E and immunostained with monoclonal anti-VEGF and anti-CD44.

RESULTS

our findings didn't reveal a statistically significant difference in the expression of VEGF(p =0.342)  and CD44 (p=0.187)  between group1 & group 2. moreover, we found tumor cells which weren't affected and resistant to radiotherapy, also revealed positive expression of VEGF & CD44, otherwise, we noticed Pearson coefficient was a significant correlation that indicated to a moderate relation.

CONCLUSION

cancerous cells that showed a high expression of these markers, give elevated radiosensitivity and resist the treatment. Subsequently, we assure the importance of applying anti-VEGF and/or anti-CD44 as a supportive therapy with radiation therapy.

Antitumor effects of bevacizumab in combination with fluoropyrimidine drugs on human oral squamous cell carcinoma

Vascular endothelial growth factor (VEGF) serves an important role in new blood vessel formation or angiogenesis, which is a critical event in tumor growth and metastasis. Bevacizumab is a humanized monoclonal antibody against VEGF-A, whereas S-1 is a fluoropyrimidine antineoplastic agent that induces apoptosis in various types of cancer cells. The present study evaluated the antitumor effects of bevacizumab in combination with 5-fluorouracil (5-FU) or S-1 against oral squamous cell carcinoma (OSCC) in vitro and in vivo. Two human OSCC cell lines were used, namely the high VEGF-A-expressing HSC-2 cells and the low VEGF-A-expressing SAS cells. MTT assay was used to evaluate the effect of bevacizumab and/or 5-FU against HSC-2 and SAS cell proliferation. Additionally, the antitumor effect of bevacizumab was evaluated alone and in combination with S-1 against HSC-2 tumors in nude mice. S-1 (6.9 mg/kg/day) was administered orally every day for 3 weeks, and bevacizumab (5 ml/kg/day) was injected intraperitoneally twice per week for 3 weeks. Apoptotic cells in mouse tumors were detected using the TUNEL method, and cell proliferation and microvessel density (MVD) were determined by immunohistochemical staining of Ki-67 and CD31, respectively. Bevacizumab alone did not inhibit OSCC cell proliferation in vitro, and did not exhibit any synergistic inhibitory effect in combination with 5-FU in vitro. However, combined bevacizumab and S-1 therapy exerted synergistic and significant antitumor effects in vivo on HSC-2 tumor xenografts, and induced apoptosis in tumor cells. Furthermore, this combination therapy led to decreased MVD and cell proliferative abilities, as well as increased apoptosis in residual tumors. The present findings suggested that the bevacizumab plus S-1 combination therapy may exert antitumor effects in high VEGF-A-expressing OSCC cells.

miR-155, miR-191, and miR-494 as diagnostic biomarkers for oral squamous cell carcinoma and the effects of Avastin on these biomarkers

Objectives

Oral squamous cell carcinoma (OSCC) is one of the most common types of head and neck cancer. MicroRNAs, as new biomarkers, are recommended for diagnosis and treatment of different types of cancers. Bevacizumab, sold under the trade name Avastin, is a humanized whole monoclonal antibody that targets and blocks VEGF-A (vascular endothelial growth factor A; angiogenesis) and oncogenic signaling pathways.

Materials and Methods

This study comprised 50 cases suffering from OSCC and 50 healthy participants. Peripheral blood samples were collected in glass test tubes, and RNA extraction was started immediately. Expression levels of miR-155, miR-191, and miR-494 biomarkers in the peripheral blood of OSCC-affected individuals and healthy volunteers in vivo were evaluated using real-time PCR. The influence of Avastin on the expression levels of the aforementioned biomarkers in vitro and in the HN5 cell line was also investigated.

Results

Expression levels of miR-155, miR-191, and miR-494 in the peripheral blood of individuals affected by OSCC were higher than in those who were healthy. Moreover, Avastin at a concentration of 400 µM caused a decrease in the expression levels of the three biomarkers and a 1.5-fold, 3.5-fold, and 4-fold increase in apoptosis in the test samples compared to the controls in the HN5 cell line after 24, 48, and 72 hours, respectively.

Conclusion

The findings of this study demonstrate that overexpression of miR-155, miR-191, and miR-494 is associated with OSCC, and Avastin is able to regulate and downregulate the expression of those biomarkers and increase apoptosis in cancerous cells in the HN5 cell line

The Application of Next-Generation Sequencing to Define Factors Related to Oral Cancer and Discover Novel Biomarkers

Despite the introduction of next-generation sequencing in the realm of DNA sequencing technology, it is not often used in the investigation of oral squamous cell carcinoma (OSCC). Oral cancer is one of the most frequently occurring malignancies in some parts of the world and has a high mortality rate. Patients with this malignancy are likely to have a poor prognosis and may suffer from severe facial deformity or mastication problems even after successful treatment. Therefore, a thorough understanding of this malignancy is essential to prevent and treat it. This review sought to highlight the contributions of next-generation sequencing (NGS) in unveiling the genetic alterations and differential expressions of miRNAs involved in OSCC progression. By applying an appropriate eligibility criterion, we selected relevant studies for review. Frequently identified mutations in genes such as TP53, NOTCH1, and PIK3CA are discussed. The findings of existing miRNAs (e.g., miR-21) as well as novel discoveries pertaining to OSCC are also covered. Lastly, we briefly mention the latest findings in targeted gene therapy and the potential use of miRNAs as biomarkers. Our goal is to encourage researchers to further adopt NGS in their studies and give an overview of the latest findings of OSCC treatment.

Celecoxib suppresses lipopolysaccharide-stimulated oral squamous cell carcinoma proliferation in vitro and in vivo

Periodontitis is one of the most common chronic oral inflammatory conditions worldwide and is associated with a risk of developing oral squamous cell carcinoma (OSCC). Porphyromonas gingivalis is a major pathogen in periodontitis, and its lipopolysaccharide (LPS) promotes the expression of cyclooxygenase-2 (COX-2) in OSCC both in vivo and in vitro. Celecoxib is a selective COX-2 inhibitor; however, its antitumor effects on P. gingivalis LPS-stimulated OSCC and the underlying molecular mechanism remain unclear. To elucidate the association between periodontitis and OSCC, the effect of P. gingivalis-derived LPS on OSCC cell proliferation was examined both in vitro and in vivo in the present study. The expression levels of COX-2 and p53 in OSCC cells with/without celecoxib treatment were determined via western blotting. The therapeutic potential of celecoxib in LPS-stimulated OSCC was evaluated by staining for Ki-67 and p21, as well as with terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling staining. LPS treatment significantly increased OSCC cell proliferation in vitro, and celecoxib significantly inhibited cell proliferation with/without LPS treatment. Celecoxib treatment of OSCC cells downregulated the protein expression levels of COX-2 compared with untreated cells, but there was little change in p53 expression. In the mouse xenograft model, oral administration of celecoxib significantly suppressed tumor growth, reduced the expression of Ki-67, increased the apoptosis index and induced p21 expression with/without LPS treatment. The results from the present study demonstrate that P. gingivalis' LPS can stimulate tumor growth by interacting with OSCC cells. In conclusion, these results suggest that celecoxib could be used for the effective prevention and treatment of LPS-stimulated OSCC.

Targeting LOX-1 Inhibits Colorectal Cancer Metastasis in an Animal Model

Recurrence and metastasis are the primary causes of mortality in patients with colorectal cancer (CRC), and therefore effective tools to reduce morbidity and mortality of CRC patients are necessary. LOX-1, the ox-LDL receptor, is strongly involved in inflammation, obesity, and atherosclerosis, and several studies have assessed its role in the carcinogenesis process linking ROS, metabolic disorders and cancer. We have already demonstrated in vitro that LOX-1 expression correlates to the aggressiveness of human colon cancer and its downregulation weakens the tumoral phenotype, indicating its potential function as a biomarker and a target in CRC therapy. Here we further investigate in vivo the role of LOX-1 in colon tumorigenesis by xenografting procedures, injecting nude mice both subcutaneously and intravenously with human high grade metastatic colorectal cancer cells, DLD-1, in which LOX-1 expression has been downregulated by shRNA (LOX-1RNAi cells). Histopathological and immunohistochemical evaluations have been performed on xenograft tumors. The experiments have been complemented by the analysis of the volatile compounds (VOCs) collected from the cages of injected mice and analyzed by gas-chromatography and gas sensors. After intravenous injection of LOX-1RNAi cells, we found that LOX-1 silencing influences both the engraftment of the tumor and the metastasis development, acting by angiogenesis. For the first time, we have observed that LOX-1 inhibition significantly prevents metastasis formation in injected mice and, at the same time, induces a downregulation of VEGF-A165, HIF-1α, and β-catenin whose expression is involved in cell migration and metastasis, and a variation of histone H4 acetylation pattern suggesting also a role of LOX-1 in regulating gene transcription. The analysis of the volatile compounds (VOCs) collected from the cages of injected mice has evidenced a specific profile in those xenograft mice in which metastasis originates. These findings underline the role of LOX-1 as a potential target for inhibition of tumor progression and metastasis, enhancing current therapeutic strategies against colorectal cancer.

Potent anti-angiogenesis and anti-tumour activity of pegaptanib-loaded tetrahedral DNA nanostructure

OBJECTIVES

Pegaptanib might be a promising anti-tumour drug targeting VEGF to inhibit tumour vascular endothelial cell proliferation. However, the poor biostability limited its application. In this study, we took tetrahedron DNA nanostructures (TDNs) as drug nanocarrier for pegaptanib to explore the potent anti-angiogenesis and anti-tumour activity of this drug delivery system.

MATERIALS AND METHODS

The successful synthesis of TDNs and pegaptanib-TDNs was determined by 8% polyacrylamide gel electrophoresis (PAGE), capillary electrophoresis and dynamic light scattering (DLS). The cytotoxicity of pegaptanib alone and pegaptanib-TDNs on HUVECs and Cal27 was evaluated by the cell count kit-8 (CCK-8) assay. The effect of pegaptanib and pegaptanib-TDNs on proliferation, migration and tube formation of HUVECs induced by VEGF was examined by CCK-8 assay, wound healing assay and tubule formation experiment. The cell binding capacity and serum stability were detected by flow cytometry and PAGE, respectively.

RESULTS

Pegaptanib-TDNs had stronger killing ability than pegaptanib alone, and the inhibiting effect was in a concentration-dependent manner. What's more, pegaptanib-loaded TDNs could effectively enhance the ability of pegaptanib to inhibit proliferation, migration and tube formation of HUVECs induced by VEGF. These might attribute to the stronger binding affinity to the cell membrane and greater serum stability of pegaptanib-TDNs.

CONCLUSIONS

These results suggested that pegaptanib-TDNs might be a novel strategy to improve anti-angiogenesis and anti-tumour ability of pegaptanib.

The therapeutic potential of epigallocatechin‑3‑gallate against human oral squamous cell carcinoma through inhibition of cell proliferation and induction of apoptosis: In vitro and in vivo murine xenograft study

Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumors in the oral region. Despite current therapeutic strategies, the survival rate has not been improved for several decades. Thus, it is important to develop a novel approach for the treatment of OSCC. Epigallocatechin-3-gallate (EGCG) is a major constituent of green tea and has previously been demonstrated to inhibit the growth of several types of cancer cells. However, few studies have investigated the effect of EGCG on human OSCC cells, especially in experimental animal models. The aim of the present study was to evaluate the therapeutic potential of EGCG for targeting human OSCC in vitro and in vivo. In the in vitro experiments, EGCG suppressed HSC-3 cell viability in a time- and dose-dependent manner. Cell cycle analysis revealed that EGCG induced G1 phase arrest of the tumor cells. Apoptosis was examined by Annexin V and propidium iodide staining, assays of caspase-3 and −7 activity and TdT-mediated dUTP nick end labeling (TUNEL) staining. Treatment with EGCG significantly increased caspase-3 and −7 activities, and the percentage of apoptotic cells when compared with control cells. In the in vivo xenograft experiment on mice, EGCG treatment resulted in a 45.2% reduction in tumor size as compared with the control group without weight loss. In vivo cell proliferation and apoptosis were assessed by immunohistochemical Ki-67 staining and the TUNEL staining. There were significant differences in Ki-67 expression between the EGCG treatment group and control group, and the percentage of apoptotic cells in the EGCG treatment group was significantly greater than that in the control group. These results indicated that EGCG significantly inhibited cell proliferation by affecting the cell cycle progression and apoptosis in vitro and in vivo. These findings suggest that EGCG may have clinical applications as a novel approach to oral-cancer therapy.