Preventive effect of celecoxib use against cancer progression and occurrence of oral squamous cell carcinoma

Oral Metronomic Chemotherapy in Advanced and Metastatic Oral Squamous Cell Carcinoma: A Need of the Hour

Aim

The present review article aims to compile the best available evidence-based data on oral metronomic chemotherapy (OMCT) including its mechanism of action, its utility, and future directions.

Methods

A systematic search was carried out in PubMed database for available English literature from last 10 years between 2011 and 2021. Keyword combinations used were 'Oral Metronomic chemotherapy for oral cancer, mechanism of action of OMCT, Oral metronomic chemotherapy in India, OMCT in recurrent and palliative treatment of oral cancers.'

Results

Multitudes of studies have been published recently stating the role of OMCT in head and neck squamous cell carcinoma (HNSCC), but the studies with the category of level of evidence required to advocate OMCT as a recognized therapy are still scarce. On careful stratification of these studies, we found that OMCT has a lot to offer in palliative settings, recurrent, and metastatic HNSCC. There is some limited evidence of its role in adjuvant therapy as maintenance and in neoadjuvant setting.

Conclusion

With current evidence, there is a definite role of OMCT in treatment of oral SCC. OMCT can be an alternative in patients who are not tolerable or affordable for standard palliative chemotherapy and also an option for patient who are waiting for surgery. However, results of ongoing and future studies on exact mechanism, indications, and implications of this drug regimen would help in integration OMCT in current standard of therapy.

Graphical abstract

NOS2 and COX-2 Co-Expression Promotes Cancer Progression: A Potential Target for Developing Agents to Prevent or Treat Highly Aggressive Breast Cancer

Nitric oxide (NO) and reactive nitrogen species (RNS) exert profound biological impacts dictated by their chemistry. Understanding their spatial distribution is essential for deciphering their roles in diverse biological processes. This review establishes a framework for the chemical biology of NO and RNS, exploring their dynamic reactions within the context of cancer. Concentration-dependent signaling reveals distinctive processes in cancer, with three levels of NO influencing oncogenic properties. In this context, NO plays a crucial role in cancer cell proliferation, metastasis, chemotherapy resistance, and immune suppression. Increased NOS2 expression correlates with poor survival across different tumors, including breast cancer. Additionally, NOS2 can crosstalk with the proinflammatory enzyme cyclooxygenase-2 (COX-2) to promote cancer progression. NOS2 and COX-2 co-expression establishes a positive feed-forward loop, driving immunosuppression and metastasis in estrogen receptor-negative (ER-) breast cancer. Spatial evaluation of NOS2 and COX-2 reveals orthogonal expression, suggesting the unique roles of these niches in the tumor microenvironment (TME). NOS2 and COX2 niche formation requires IFN-γ and cytokine-releasing cells. These niches contribute to poor clinical outcomes, emphasizing their role in cancer progression. Strategies to target these markers include direct inhibition, involving pan-inhibitors and selective inhibitors, as well as indirect approaches targeting their induction or downstream effectors. Compounds from cruciferous vegetables are potential candidates for NOS2 and COX-2 inhibition offering therapeutic applications. Thus, understanding the chemical biology of NO and RNS, their spatial distribution, and their implications in cancer progression provides valuable insights for developing targeted therapies and preventive strategies.

Preparation of celecoxib loaded bioactive glass chitosan composite hydrogels: a simple approach for therapeutic delivery of NSAIDs

Arthritis causes inflammatory damage to joints and connective tissues. In the treatment of arthritis, precise and controlled drug delivery to the target site is among the frontline research approaches. In the present research work, celecoxib drug and bioactive glass incorporated chitosan hydrogels were fabricated by the freeze gelation method. Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis/differential scanning calorimetry techniques were used to characterize the hydrogels. Different kinetic models were applied to study the drug release kinetics. The celecoxib release was mainly controlled by a Fickian diffusion process followed by the Higuchi model. Maximum 86.2% drug entrapment was observed in 20 mg drug-loaded hydrogel and its swelling ratio was 115.5% in 28 d. Good hydrophilicity, good drug entrapment efficiency, and moderate drug release patterns of hydrogels can make them suitable for sustained drug release. The cytocompatibility of hydrogels was established by performing an MTT assay on the BHK-21 fibroblast cell line. The promising results have proved that hydrogels can be considered potential material for the slow release of anti-inflammatory drug at the target site in arthritis.

Advances in Small Molecular Agents against Oral Cancer

Oral cancer is a common malignancy with a high mortality rate. Although surgery is the best treatment option for patients with cancer, this approach is ineffective for advanced metastases. Molecular agents are irreplaceable in preventing and treating distant metastases. This review aims to summarise the molecular agents used for the treatment of oral cancer in the last decade and describe their sources and curative effects. These agents are classified into phenols, isothiocyanates, anthraquinones, statins, flavonoids, terpenoids, and steroids. The mechanisms of action of these agents include regulating the expression of cell signalling pathways and related proteases to affect the proliferation, autophagy, migration, apoptosis, and other biological aspects of oral cancer cells. This paper may serve as a reference for subsequent studies on the treatment of oral cancer.

Systematic Review of Roles of Arecoline and Arecoline N-Oxide in Oral Cancer and Strategies to Block Carcinogenesis

Betel quid and areca nut are complex mixture carcinogens, but little is known about whether their derived single-agent arecoline or arecoline N-oxide (ANO) is carcinogenic, and the underlying mechanisms remain unclear. In this systematic review, we analyzed recent studies on the roles of arecoline and ANO in cancer and strategies to block carcinogenesis. In the oral cavity, flavin-containing monooxygenase 3 oxidizes arecoline to ANO, and both alkaloids conjugate with N-acetylcysteine to form mercapturic acid compounds, which are excreted in urine, reducing arecoline and ANO toxicity. However, detoxification may not be complete. Arecoline and ANO upregulated protein expression in oral cancer tissue from areca nut users compared to expression levels in adjacent normal tissue, suggesting a causal relationship between these compounds and oral cancer. Sublingual fibrosis, hyperplasia, and oral leukoplakia were diagnosed in mice subjected to oral mucosal smearing of ANO. ANO is more cytotoxic and genotoxic than arecoline. During carcinogenesis and metastasis, these compounds increase the expression of epithelial-mesenchymal transition (EMT) inducers such as reactive oxygen species, transforming growth factor-β1, Notch receptor-1, and inflammatory cytokines, and they activate EMT-related proteins. Arecoline-induced epigenetic markers such as sirtuin-1 hypermethylation, low protein expression of miR-22, and miR-886-3-p accelerate oral cancer progression. Antioxidants and targeted inhibitors of the EMT inducers used reduce the risk of oral cancer development and progression. Our review findings substantiate the association of arecoline and ANO with oral cancer. Both of these single compounds are likely carcinogenic to humans, and their mechanisms and pathways of carcinogenesis are useful indicators for cancer therapy and prognosis.

Celecoxib, a Non-Steroidal Anti-Inflammatory Drug, Exerts a Toxic Effect on Human Melanoma Cells Grown as 2D and 3D Cell Cultures

Cutaneous melanoma (CM) remains one of the leading causes of tumor mortality due to its high metastatic spread. CM growth is influenced by inflammation regulated by prostaglandins (PGs) whose synthesis is catalyzed by cyclooxygenases (COXs). COX inhibitors, including non-steroidal anti-inflammatory drugs (NSAIDs), can inhibit tumor development and growth. In particular, in vitro experiments have shown that celecoxib, a NSAID, inhibits the growth of some tumor cell lines. However, two-dimensional (2D) cell cultures, used in traditional in vitro anticancer assays, often show poor efficacy due to a lack of an in vivo like cellular environment. Three-dimensional (3D) cell cultures, such as spheroids, are better models because they can mimic the common features displayed by human solid tumors. Hence, in this study, we evaluated the anti-neoplastic potential of celecoxib, in both 2D and 3D cell cultures of A2058 and SAN melanoma cell lines. In particular, celecoxib reduced the cell viability and migratory capability and triggered the apoptosis of melanoma cells grown as 2D cultures. When celecoxib was tested on 3D melanoma cell cultures, the drug exerted an inhibitory effect on cell outgrowth from spheroids and reduced the invasiveness of melanoma cell spheroids into the hydrogel matrix. This work suggests that celecoxib could represent a new potential therapeutic approach in melanoma therapy.

The effects of epithelial-mesenchymal transitions in COPD induced by cigarette smoke: an update

Cigarette smoke is a complex aerosol containing a large number of compounds with a variety of toxicity and carcinogenicity. Long-term exposure to cigarette smoke significantly increases the risk of a variety of diseases, including chronic obstructive pulmonary disease (COPD) and lung cancer. Epithelial–mesenchymal transition (EMT) is a unique biological process, that refers to epithelial cells losing their polarity and transforming into mobile mesenchymal cells, playing a crucial role in organ development, fibrosis, and cancer progression. Numerous recent studies have shown that EMT is an important pathophysiological process involved in airway fibrosis, airway remodeling, and malignant transformation of COPD. In this review, we summarized the effects of cigarette smoke on the development and progression of COPD and focus on the specific changes and underlying mechanisms of EMT in COPD induced by cigarette smoke. We spotlighted the signaling pathways involved in EMT induced by cigarette smoke and summarize the current research and treatment approaches for EMT in COPD, aiming to provide ideas for potential new treatment and research directions.

Epithelial–mesenchymal transition: The history, regulatory mechanism, and cancer therapeutic opportunities

Epithelial–mesenchymal transition (EMT) is a program wherein epithelial cells lose their junctions and polarity while acquiring mesenchymal properties and invasive ability. Originally defined as an embryogenesis event, EMT has been recognized as a crucial process in tumor progression. During EMT, cell–cell junctions and cell–matrix attachments are disrupted, and the cytoskeleton is remodeled to enhance mobility of cells. This transition of phenotype is largely driven by a group of key transcription factors, typically Snail, Twist, and ZEB, through epigenetic repression of epithelial markers, transcriptional activation of matrix metalloproteinases, and reorganization of cytoskeleton. Mechanistically, EMT is orchestrated by multiple pathways, especially those involved in embryogenesis such as TGFβ, Wnt, Hedgehog, and Hippo, suggesting EMT as an intrinsic link between embryonic development and cancer progression. In addition, redox signaling has also emerged as critical EMT modulator. EMT confers cancer cells with increased metastatic potential and drug resistant capacity, which accounts for tumor recurrence in most clinic cases. Thus, targeting EMT can be a therapeutic option providing a chance of cure for cancer patients. Here, we introduce a brief history of EMT and summarize recent advances in understanding EMT mechanisms, as well as highlighting the therapeutic opportunities by targeting EMT in cancer treatment.

Preliminary evaluation of anticancer efficacy of pioglitazone combined with celecoxib for the treatment of non-small cell lung cancer

PURPOSE

Among the lung cancer types, non-small cell lung cancer (NSCLC) is prominent and less responsive to chemotherapy. The current chemotherapeutics for NSCLC are associated with several dose-limiting side effects like bone-marrow suppression, neurotoxicity, nephrotoxicity, and ototoxicity, etc. which are causing non-compliance in patients. Many tumors, including breasts, lung, ovarian, etc. overexpress PPAR-γ receptors and COX-2 enzymes, which play a crucial role in tumor progression, angiogenesis, and metastasis. Lack of PPAR-γ activation and overproduction of prostaglandins, result in uncontrolled activation of Ras/Raf/Mek ultimately, NF-κB mediated tumor proliferation. This study aimed to investigate the anti-cancer potential of PPAR-γ agonist Pioglitazone combined with COX-2 inhibitor Celelcoxib in NSCLC.

METHODS

Sixty adult Balb/C male mice were classified into sham control, disease control, and treatment groups. Mice were treated with Nicotine-derived nitrosamine ketone (NNK) (10 mg/kg), pioglitazone (10 & 20 mg/kg) and celecoxib (25 & 50 mg/kg). Weekly body weight, food intake, mean survival time & % increased life span were determined. Tumor weight and histopathological analysis were performed at the end of the study.

RESULTS

The significant tumor reducing potential of pioglitazone combined with celecoxib was observed (p < 0.05). The treatment groups (treated with pioglitazone and celecoxib) showed a remarkable decrease in lung tumor weight, improved life span and mean survival time (p < 0.05). Histopathological studies confirm that treatment groups (treated with pioglitazone and celecoxib) reframed the lung architecture compared to disease control.

CONCLUSION

Preliminary results revealed that pioglitazone adjunacy with celecoxib may be an effective chemo-preventive agent against NNK induce NSCLC.

New Angiogenic Regulators Produced by TAMs: Perspective for Targeting Tumor Angiogenesis

Simple Summary

Since the targeting of a single pro-angiogenic factor fails to improve oncological disease outcome, significant efforts have been made to identify new pro-angiogenic factors that could compensate for the deficiency of current therapy or act independently as single drugs. Our review aims to present the state-of-the art for well-known and recently described factors produced by macrophages that induce and regulate angiogenesis. A number of positive and negative regulators of angiogenesis in the tumor microenvironment are produced by tumor-associated macrophages (TAMs). Accumulating evidence has indicated that, apart from the well-known angiogenic factors, there are plenty of novel angiogenesis-regulating proteins that belong to different classes. We summarize the data regarding the direct or indirect mechanisms of the interaction of these factors with endothelial cells during angiogenesis. We highlight the recent findings that explain the limitations in the efficiency of current anti-angiogenic therapy approaches.

Abstract

Angiogenesis is crucial to the supply of a growing tumor with nutrition and oxygen. Inhibition of angiogenesis is one of the main treatment strategies for colorectal, lung, breast, renal, and other solid cancers. However, currently applied drugs that target VEGF or receptor tyrosine kinases have limited efficiency, which raises a question concerning the mechanism of patient resistance to the already developed drugs. Tumor-associated macrophages (TAMs) were identified in the animal tumor models as a key inducer of the angiogenic switch. TAMs represent a potent source not only for VEGF, but also for a number of other pro-angiogenic factors. Our review provides information about the activity of secreted regulators of angiogenesis produced by TAMs. They include members of SEMA and S100A families, chitinase-like proteins, osteopontin, and SPARC. The COX-2, Tie2, and other factors that control the pro-angiogenic activity of TAMs are also discussed. We highlight how these recent findings explain the limitations in the efficiency of current anti-angiogenic therapy. Additionally, we describe genetic and posttranscriptional mechanisms that control the expression of factors regulating angiogenesis. Finally, we present prospects for the complex targeting of the pro-angiogenic activity of TAMs.

Long noncoding RNA HAR1A regulates oral cancer progression through the alpha-kinase 1, bromodomain 7, and myosin IIA axis

Studies suggested that long noncoding HAR1A RNA may be a tumor suppressor, but its association with oral cancer remains unclear. Here, we show the functional role and mechanisms of HAR1A in oral cancer progression. Microarray analysis was performed to screen the related candidates of long noncoding RNA (lncRNA) in human monocytes. Following lncRNA HAR1A, the regulation of HAR1A, ALPK1, myosin IIA, and BRD7 was tested using reverse-transcription quantitative polymerase chain reaction (RT-qPCR) in oral cancer cells. The inflammatory and epithelial-to-mesenchymal transition marker expressions were analyzed using enzyme-linked immunosorbent assay and western blot. Phenotypic experiments were verified by colony formation assay, transwell migration assay, and Annexin V-apoptotic assay. In the nuclei of cancer cells, HAR1A functions upstream of signaling pathways and knockdown of HAR1A promoted ALPK1 expression and downregulated BRD7 resulting in inflammation and oral cancer progression. In monocytes, the expressions of TNF-α and CCL2 were increased following HAR1A knockdown and reduced following ALPK1 knockdown. HAR1A knockdown upregulated the expression of ALPK1, slug, vimentin, fibronectin, and N-cadherin but reduced the expression of E-cadherin in oral cancer cells. Myosin IIA was primarily located in the cytoplasm and that its decrease in the nuclei of oral cancer cells was likely to demonstrate suppressive ability in late-stage cancer. Our findings suggest that the HAR1A, BRD7, and myosin IIA are tumor suppressors while ALPK1 has oncogene-like property in the nucleus and is involved in inflammation and oral cancer progression. More research for HAR1A activators or ALPK1 inhibitors is required to develop potential therapeutic agents for advanced oral cancer. KEY MESSAGES: lncRNA HAR1A, BRD7, and myosin IIA are tumor suppressors whereas ALPK1 has an oncogenic-like property in the nucleus. lncRNA HAR1A/ALPK1/BRD7/myosin IIA axis plays a critical role in the progression of oral cancer. lncRNA HAR1A localizes upstream of signaling pathways to inhibit ALPK1 expression and then upregulated BRD7. lncRNA HAR1A and ALPK1 are involved in cancer progression via epithelial-to-mesenchymal transition regulations. ALPK1 inhibitors are potential kinase-targeted therapeutic agents for patients with advanced oral cancer.

Macrophage 3D migration: A potential therapeutic target for inflammation and deleterious progression in diseases

Macrophages are heterogeneous cells that have different physiological functions, such as chemotaxis, phagocytosis, endocytosis, and secretion of various factors. All physiological functions of macrophages are integral to homeostasis, immune defense and tissue repair. However, in several diseases, macrophages are recruited from the blood towards inflammatory sites. This process is called macrophage migration, which promotes deleterious disease progression. Macrophage migration is a key player in many inflammatory diseases, autoimmune diseases and cancers because it contributes to the accumulation of proinflammatory factors, the destruction of tissues and the development of tumors. Therefore, macrophage migration is proposed to be a potential therapeutic target. Macrophages migrate between two-dimensional (2D) and three-dimensional (3D) environments, implying that distinct migratory features and mechanisms are involved. Compared with the 2D migration of macrophages, 3D migration involves more complex variations in cellular morphology and dynamics. The structure of the extracellular matrix, a key factor, is modified in diseases that influence macrophage 3D migration. Macrophage 3D migration relates to disease pathology. Research that focuses on macrophage 3D migration is an emerging field and was reviewed in this article to indicate the molecular and cellular mechanisms of macrophage migration in 3D environments and to provide potential targets for controlling disease progression associated with this migration.

Head and neck cancer and non-steroidal anti-inflammatory drugs: Systematic review and meta-analysis

The objective was to assess the effects of non-steroidal anti-inflammatory drugs (NSAIDs) on head and neck cancer (HNC) outcomes. A systematic review was conducted following the PRISMA guidelines. The MEDLINE and the Cochrane Central Register databases were searched. Risk of bias was assessed by the Cochrane Collaboration's tool and by the Newcastle-Ottawa Scale. Meta-analyses were performed with the RevMan software. Seventeen articles met the inclusion criteria. Quality scores for observational studies ranged between 5 and 8 stars and the RCT was assessed as high risk of bias. NSAIDs use was associated with a 13% risk reduction of HNC (OR: 0.87 95% CI 0.77-0.99). NSAIDs use was associated with a 30% reduced cancer-specific mortality and with a 40% decreased risk on disease-recurrence. NSAIDs may have a modest protective effect on HNC risk and a positive impact on cancer-specific survival and disease-recurrence. The findings do not support a protective role of aspirin on HNC outcomes.

New Insights into Oral Cancer-Risk Factors and Prevention: A Review of Literature

The oral cancer constitutes 48% of head and neck cancer cases. Ninety percent of oral cancer cases are histologically diagnosed as oral squamous cell carcinomas (OSCCs). Despite new management strategies, the 5-year survival rate of oral cancer is still below 50% in most countries. Head and neck cancers are heterogeneous tumors, and this characteristic of them provides a challenge to treatment plan. Due to the poor outcomes in oral cancer, prevention is a necessity. In this review, a relevant English Literature search in PubMed, ScienceDirect, and Google Scholar from 2000 to mid-2018 was performed. All published articles related to oral cancer and its prevention were included. The risk factors of oral cancer and strategies of oral cancer prevention will be discussed.

Non-Steroidal Anti-Inflammatory Drugs Increase Cisplatin, Paclitaxel, and Doxorubicin Efficacy against Human Cervix Cancer Cells

This study shows that the non-steroidal anti-inflammatory drug (NSAID) celecoxib and its non-cyclooxygenase-2 (COX2) analogue dimethylcelecoxib (DMC) exert a potent inhibitory effect on the growth of human cervix HeLa multi-cellular tumor spheroids (MCTS) when added either at the beginning (“preventive protocol”; IC₅₀ = 1 ± 0.3 nM for celecoxib and 10 ± 2 nM for DMC) or after spheroid formation (“curative protocol”; IC₅₀ = 7.5 ± 2 µM for celecoxib and 32 ± 10 µM for DMC). These NSAID IC₅₀ values were significantly lower than those attained in bidimensional HeLa cells (IC₅₀ = 55 ± 9 µM celecoxib and 48 ± 2 µM DMC) and bidimensional non-cancer cell cultures (3T3 fibroblasts and MCF-10A mammary gland cells with IC₅₀ from 69 to >100 µM, after 24 h). The copper-based drug casiopeina II-gly showed similar potency against HeLa MCTS. Synergism analysis showed that celecoxib, DMC, and casiopeinaII-gly at sub-IC₅₀ doses increased the potency of cisplatin, paclitaxel, and doxorubicin to hinder HeLa cell proliferation through a significant abolishment of oxidative phosphorylation in bidimensional cultures, with no apparent effect on non-cancer cells (therapeutic index >3.6). Similar results were attained with bidimensional human cervix cancer SiHa and human glioblastoma U373 cell cultures. In HeLa MCTS, celecoxib, DMC and casiopeina II-gly increased cisplatin toxicity by 41–85%. These observations indicated that celecoxib and DMC used as adjuvant therapy in combination with canonical anti-cancer drugs may provide more effective alternatives for cancer treatment.

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 in Cancer Therapy and Prevention - Review

BACKGROUND AND OBJECTIVES

It is generally accepted that inflammatory cells found in the tumor microenvironment are involved in the neoplastic process, promoting cell proliferation, survival, and migration. Therefore, administering anti-inflammatory medication in cancer therapy seems to be justified. A potential pathway associated with the aforementioned issue is cyclooxygenase-2 inhibition, particularly as the overexpression of this enzyme has been proven to occur in cancer tissues and is also associated with a poor prognosis in several types of human malignancies. Celecoxib, a COX-2 selective inhibitor, has been utilized for over 20 years, particularly as an anti-inflammatory, analgesic and antipyretic medication. However, to date, its antineoplastic properties have not been sufficiently investigated. In recent years, the number of research studies on the antineoplastic effects of celecoxib has increased considerably. The vast majority of publications refers to preclinical studies attempting to elucidate its mechanisms of action. Clinical trials concerning celecoxib have focused primarily on the treatment of cancers of the colon, breast, lung, prostate, stomach, head and neck, as well as premalignant lesions such as familial adenoma polyposis. In this review article authors attempt to summarise the latest research which has elucidated celecoxib use in the treatment and prevention of cancer.

CONCLUSION

Both preclinical and clinical studies have demonstrated promising results of the role of celecoxib in the treatment and prevention of cancer - the best outcome was observed in colon, breast, prostate and head and neck cancers. However, more clinical trials providing real evidence-based clinical advances of celecoxib use are needed.

Structural Modification of Nanomicelles through Phosphatidylcholine: The Enhanced Drug-Loading Capacity and Anticancer Activity of Celecoxib-Casein Nanoparticles for the Intravenous Delivery of Celecoxib

This study aims to stabilize loaded celecoxib (CX) by modifying the structure of casein nanoparticles through phosphatidylcholine. The results show that Egg yolk phosphatidylcholine PC_98T (PC) significantly increased the stability of CX-PC-casein nanoparticles (NPs) (192.6 nm) from 5 min (CX-β-casein-NPs) to 2.5 h at 37 °C. In addition, the resuspended freeze-dried NPs (202.4 nm) remained stable for 2.5 h. Scanning electron microscopy indicated that PC may block the micropore structures in nanoparticles by ultrasonic treatment and hence improve the physicochemical stability of CX-PC-casein-NPs. The stability of the NPs was positively correlated with their inhibiting ability for human malignant melanoma A375 cells. The structural modification of CX-PC-casein-NPs resulted in an increased intracellular uptake of CX by 2.4 times than that of the unmodified ones. The pharmacokinetic study showed that the Area Under Curve (AUC) of the CX-PC-casein-NPs was 2.9-fold higher in rats than that of the original casein nanoparticles. When CX-PC-casein-NPs were intravenously administrated to mice implanted with A375 tumors (CX dose = 16 mg/kg bodyweight), the tumor inhibition rate reached 56.2%, which was comparable to that of paclitaxel (57.3%) at a dose of 4 mg/kg bodyweight. Our results confirm that the structural modification of CX-PC-casein-NPs can effectively prolong the remaining time of specific drugs, and may provide a potential strategy for cancer treatment.

Betel quid-associated cancer: Prevention strategies and targeted treatment

Betel quid (BQ) and areca nut use are at risk of cancer. This review includes the latest evidence of carcinogenesis caused by BQ exposure, suggests possible prevention strategies. We conducted a systematic literature search in the PubMed and Web of Science databases to identify relevant articles published in the past 10 years according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. Arecoline N-oxide, a metabolite of areca nut, is likely an initiator in carcinogenesis and is detoxified by N-acetylcysteine. Oral potentially malignant disorder and reactive oxygen species involved in carcinogenesis pathways may be treatable using antioxidants. Screening programs conducted by trained physicians are useful for identifying patients with early stages of oral cancer in high-risk groups. Anti-inflammatory medications may be used as chemopreventive agents in the disease-free stage after surgery. The association between survival and tumor somatic mutations in patients who chew BQ should be addressed in cancer studies. Current evidence on the natural course from BQ exposure to cancer occurrence and development provides information for developing primary, secondary, and tertiary prevention strategies against BQ-associated cancer at clinical or translational levels.

Proline-Dependent Induction of Apoptosis in Oral Squamous Cell Carcinoma (OSCC)-The Effect of Celecoxib

Background: Oral squamous cell carcinoma remains a significant worldwide public health challenge, associated with high morbidity and mortality. Treatment of this type of cancer lacks effective medication. Moreover, there are very few specific biomarkers that are useful in early diagnosis or treatment optimisation. Proline metabolism may prove to be of importance in the search for new treatment modalities. Methods: To evaluate the significance of proline metabolism in the development of oral cancer, proline concentration was assessed in oral cancer tissue and normal oral mucosa. The results were compared to the clinical stage and histological grade of the tumours. Moreover, the expression of proteins involved in proline metabolism via proline dehydrogenase/oxidase (PRODH/POX, PPARγ, HIF1-α) was determined. In the next stage of the study, conducted on cell lines of tongue cancer treated with celecoxib, the aforementioned factors involved in proline metabolism were evaluated. Cellular viability and cell proliferation, as well as apoptosis, were also assessed. Results: Our research results indicate that a high intracellular proline concentration and expression of factors involved in its metabolism correlate with the clinical stage and histological grade of oral cancer. Moreover, we are the first researchers to demonstrate that celecoxib can affect proline metabolism, causing an increase in pro-apoptotic factors (PRODH/POX, PPARγ), reducing the expression of HIF-1α and activating apoptosis. Conclusions: Proline metabolism, due to its involvement in the process of apoptosis, can be of great importance in anticancer therapy. It appears that celecoxib, which influences the PRODH/POX pathway, may be a promising therapeutic compound in oral cancer 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.

COX-2 as a determinant of lower disease-free survival for patients affected by ameloblastoma

Ameloblastoma is a locally aggressive neoplasm with a poorly understood pathogenesis. Therefore, the aim of this study is to investigate whether COX-2 expression is associated with ameloblastoma microvascular density (MVD) and with tumor aggressiveness. Sixty-three cases of primary ameloblastomas arranged in tissue microarray were submitted to immunohistochemistry against cyclooxigenase-2 (COX-2) and CD34. Clinicopathological parameters regarding sex, age, tumour size, tumour duration, tumour location, treatment, recurrences, radiographic features, vestibular/lingual and basal cortical disruption and follow-up data were obtained from patients' medical records and correlated with the proteins expression. The results on BRAF-V600E expression were obtained from our previous study and correlated with COX-2 and CD34 expressions. Log-rank univariate analysis and multivariate Cox regression model were done to investigate the prognostic potential of the molecular markers. Twenty-eight cases (44.4%) exhibited cytoplasmic positivity for COX-2, predominantly in the columnar peripheral cells, with a mean MVD of 2.2 vessels/mm². COX-2 was significantly associated with recurrences (p < 0.001) and BRAF-V600E expression (p < 0.001), whereas lower MVD was associated with the use of conservative therapy (p = 0.004). Using univariate and multivariate analyses, COX-2 was significantly associated with a lower 5-year disease-free survival (DFS) rate (p < 0.001 and p = 0.012, respectively), but not with a higher MVD (p = 0.68). In conclusion, COX-2 expression in ameloblastomas is not associated with MVD, but it is significantly associated with recurrences and with a lower DFS.

Pterostilbene modulates the suppression of multidrug resistance protein 1 and triggers autophagic and apoptotic mechanisms in cisplatin-resistant human oral cancer CAR cells via AKT signaling

Pterostilbene is a natural polyphenolic compound that is primarily found in fruits, such as blueberries and has a similar structure to resveratrol. Pterostilbene exhibits antioxidant, anti-inflammatory and antitumor activity but the effects of pterostilbene on drug-resistant oral cancer cells and its underlying mechanisms of action have not yet been explored. Therefore, the present study was performed to clarify the anticancer effects of pterostilbene on cisplatin-resistant human oral cancer CAR cells. The results demonstrated that CAR cells exhibited marked shrinkage, cell membrane breakage and autophagic vacuole formation following treatment with pterostilbene. Pterostilbene also effectively inhibited cell viability and suppressed cell confluence in a time- and concentration-dependent manner. Probing with acridine orange, monodansylcadaverine and LysoTracker Red demonstrated that the number of acidic vesicular organelles was increased, indicating increased autophagy. Furthermore, Heochst 33342 staining determined that DNA condensation, a characteristic of apoptosis, was enhanced following treatment with pterostilbene. Furthermore, pterostilbene upregulated mRNA levels of LC3-II and Atg12, as well as the expression of Atgs/Beclin-1/LC3-associated signaling, suggesting that it enhances autophagy. The autophagy inhibitors 3-methyladenine and chloroquine were used to confirm that pterostilbene induces autophagy. It was also determined that pterostilbene triggered caspase-dependent apoptosis by directly testing DNA breakage and using the pan-caspase inhibitor carbobenzoxyvalyl-alanyl-aspartyl fluoromethyl ketone. The results demonstrated that pterostilbene mediates the apoptosis of CAR cells via the intrinsic apoptotic cascade. In addition, pterostilbene inhibited MDR1 expression and the phosphorylation of AKT on the Ser473 site in CAR cells. Therefore, pterostilbene may elicit an oral anticancer response in drug-resistant cells and may be used as a chemotherapeutic adjuvant to treat patients with oral cancer.