Inhibitory effects of Leucaena leucocephala on the metastasis and invasion of human oral cancer cells

Dietary plants for oral cancer prevention and therapy: A review of preclinical and clinical studies

Oral cancer is a disease with high mortality and rising incidence worldwide. Although fragmentary literature on the anti-oral cancer effects of plant products has been published, a comprehensive analysis is lacking. In this work, a critical and comprehensive evaluation of oral cancer preventative or therapeutic effects of dietary plants was conducted. An exhaustive analysis of available data supports that numerous dietary plants exert anticancer effects, including suppression of cell proliferation, viability, autophagy, angiogenesis, invasion, and metastasis while promoting cell cycle arrest and apoptosis. Plant extracts and products target several cellular mechanisms, such as the reversal of epithelial-to-mesenchymal transition and the promotion of oxidative stress and mitochondrial membrane dysfunction by modulation of various signaling pathways. These agents were also found to regulate cellular growth signaling pathways by action on extracellular signal-regulated kinase and mitogen-activated protein kinase, inflammation via modulation of cyclooxygenase (COX)-1, COX-2, and nuclear factor-κB p65, and metastasis through influence of cadherins and matrix metalloproteinases. In vivo studies support these findings and demonstrate a decrease in tumor burden, incidence, and hyperplastic and dysplastic changes. Clinical studies also showed decreased oral cancer risk. However, high-quality studies should be conducted to establish the clinical efficacy of these plants. Overall, our study supports the use of dietary plants, especially garlic, green tea, longan, peppermint, purple carrot, saffron, tomato, and turmeric, for oral cancer prevention and intervention. However, further research is required before clinical application of this strategy.

Tumor-associated macrophages-derived exo-let-7a promotes osteosarcoma metastasis via targeting C15orf41 in osteosarcoma

BACKGROUND

Osteosarcoma (OS) immune environment is complexed and the immune factors-related to OS progression need to be explored. Tumor-associated macrophages (TAMs) are regarded as immune suppressive and tumor-promoting cells. However, the underlying mechanisms through which TAMs function are still fragmentary. Here, we aim to explore the underlying mechanisms by which TAMs regulate OS progression.

METHODS

TAMs from OS tissues were isolated by flow cytometry. Exosomes derived from TAMs were separated using ultracentrifugation and western blotting. Transmission electron microscopy (TEM), and flow cytometry were constructed to characterize TAMs-derived exosomes. Additionally, the differential MicroRNAs (miRNAs) and genes were detected through RNA sequencing, and further validated using real-time PCR (RT-PCR). OS cell metastasis ability was assessed using transwell invasion and scratch wound healing assays. MiRNAs mimic and lentiviral vectors were utilized to explore the effects on OS progression.

RESULTS

Exosome secreted by TAMs accelerated the OS metastasis. Let-7a level was upregulated in TAMs derived exosomes, which downregulated C15orf41 by targeting 3'-untranslated region (UTR). Furthermore, overexpressing let-7a enhanced invasion and migration by blocking the transcription of C15orf41. In consistent, up-regulating let-7a promoted OS progression and made the prognosis to be worse, which can be reversed by C15orf41 overexpression.

CONCLUSION

This study highlighted the critical role of TAMs-derived exosomes in OS progression and explored the potential value of the let-7a/C15orf41 axis as an indicator or target for OS.

Anthelmintic Effect of Leucaena leucocephala Extract and Its Active Compound, Mimosine, on Vital Behavioral Activities in Caenorhabditis elegans

Helminth infections continue to be a neglected global threat in tropical regions, and there have been growing cases of anthelmintic resistance reported towards the existing anthelmintic drugs. Thus, the search for a novel anthelmintic agent has been increasing, especially those derived from plants. Leucaena leucocephala (LL) is a leguminous plant that is known to have several pharmacological activities, including anthelmintic activity. It is widely known to contain a toxic compound called mimosine, which we believed could be a potential lead candidate that could exert a potent anthelmintic effect. Hence, this study aimed to validate the presence of mimosine in LL extract and to investigate the anthelmintic effect of LL extract and mimosine on head thrashing, egg-laying, and pharyngeal pumping activities using the animal model Caenorhabditis elegans (C. elegans). Mimosine content in LL extract was confirmed through an HPLC analysis of spiking LL extract with different mimosine concentrations, whereby an increasing trend in peak heights was observed at a retention time of 0.9 min. LL extract and mimosine caused a significant dose-dependent increase in the percentage of worm mortality, which produced LC50s of 73 mg/mL and 6.39 mg/mL, respectively. Exposure of C. elegans to different concentrations of LL extract and mimosine significantly decreased the head thrashing, egg-laying, and mean pump amplitude of pharyngeal pumping activity. We speculated that these behavioral changes are due to the inhibitory effect of LL extract and mimosine on an L-type calcium channel called EGL-19. Our findings provide evidential support for the potential of LL extract and its active compound, mimosine, as novel anthelmintic candidates. However, the underlying mechanism of the anthelmintic action has yet to be elucidated.

Phytochemicals as Potential Chemopreventive and Chemotherapeutic Agents for Emerging Human Papillomavirus-Driven Head and Neck Cancer: Current Evidence and Future Prospects

Head and neck cancer (HNC) usually arises from squamous cells of the upper aerodigestive tract that line the mucosal surface in the head and neck region. In India, HNC is common in males, and it is the sixth most common cancer globally. Conventionally, HNC attributes to the use of alcohol or chewing tobacco. Over the past four decades, portions of human papillomavirus (HPV)-positive HNC are increasing at an alarming rate. Identification based on the etiological factors and molecular signatures demonstrates that these neoplastic lesions belong to a distinct category that differs in pathological characteristics and therapeutic response. Slow development in HNC therapeutics has resulted in a low 5-year survival rate in the last two decades. Interestingly, HPV-positive HNC has shown better outcomes following conservative treatments and immunotherapies. This raises demand to have a pre-therapy assessment of HPV status to decide the treatment strategy. Moreover, there is no HPV-specific treatment for HPV-positive HNC patients. Accumulating evidence suggests that phytochemicals are promising leads against HNC and show potential as adjuvants to chemoradiotherapy in HNC. However, only a few of these phytochemicals target HPV. The aim of the present article was to collate data on various leading phytochemicals that have shown promising results in the prevention and treatment of HNC in general and HPV-driven HNC. The review explores the possibility of using these leads against HPV-positive tumors as some of the signaling pathways are common. The review also addresses various challenges in the field that prevent their use in clinical settings.

Traditional Herbal Medicine Mediated Regulations during Head and Neck Carcinogenesis

Head and neck squamous cell carcinoma (HNSCC) is one of the most prevalent neoplasms worldwide. It is well recognized that environmental challenges such as smoking, viral infection and alcohol consumption are key factors underlying HNSCC pathogenesis. Other than major clinical interventions (e.g., surgical resection, chemical and radiotherapy) that have been routinely practiced over years, adjuvant anticancer agents from Traditional Herbal Medicine (THM) are proposed, either alone or together with conventional therapies, to be experimentally effective for improving treatment efficacy in different cancers including HNSCCs. At a cellular and molecular basis, THM extracts could modulate different malignant indices via distinct signaling pathways and provide better control in HNSCC malignancy and its clinical complications such as radiotherapy-induced xerostomia/oral mucositis. In this article, we aim to systemically review the impacts of THM in regulating HNSCC tumorous identities and its potential perspective for clinical use.

Modulating effect of Coronarin D in 5-fluorouracil resistance human oral cancer cell lines induced apoptosis and cell cycle arrest through JNK1/2 signaling pathway

Coronarin D (CD) is one of the main components of Hedychium coronarium rhizome, which has therapeutic potential by reducing cell proliferation in cancer cells. However, the mechanism of CD to 5-fluorouracil (5FU) oral cancer cell remain unclearly. This study discusses the CD to 5FU chemoresistance oral squamous cell carcinoma (OSCC) biochemical mechanisms and possibly pathways to inhibit multiplication in oral cancer. The effect of CD-treated 5FU-chemoresistance human oral cancer cell lines were subjected to MTT assay, cell cycle assay, DAPI assay, annexin-V/PI double staining assay and mitochondrial membrane potential measurement. Furthermore, western blotting was performed to assess the effect of CD on the expression levels of apoptosis related protein and MAPK signaling pathway. The results of the study evidenced that CD reduced viability of 5FU cancer cells in a dose- and time-dependent manner compared with control. The cytotoxic effect of CD lead to cell cycle arrest in the G2/M phase and induced apoptosis in both internal and external pathways. CD induces apoptosis by enhancing phosphorylation of JNK, further exploring the combination of CD and SP600125 reduced the overexpression of phosphate JNK levels. The mechanism of action of CD in 5FU on human oral cancer cells is reported for the first time and can hopeful to be a potential therapeutic agent for 5FU against human oral cancer cells.

Antimetastatic Effects of Sesamin on Human Head and Neck Squamous Cell Carcinoma through Regulation of Matrix Metalloproteinase-2

Background: Sesamin is a lignin present in sesame oil from the bark of Zanthoxylum spp. Sesamin reportedly has anticarcinogenic potential and exerts anti-inflammatory effects on several tumors. Hypothesis/Purpose: However, the effect of sesamin on metastatic progression in human head and neck squamous carcinoma (HNSCC) remains unknown in vitro and in vivo; hence, we investigated the effect of sesamin on HNSCC cells in vitro. Methods and Results: Sesamin-treated human oral cancer cell lines FaDu, HSC-3, and Ca9-22 were subjected to a wound-healing assay. Furthermore, Western blotting was performed to assess the effect of sesamin on the expression levels of matrix metalloproteinase (MMP)-2 and proteins of the MAPK signaling pathway, including p-ERK1/2, P-p38, and p-JNK1/2. In addition, we investigated the association between MMP-2 expression and the MAPK pathway in sesamin-treated oral cancer cells. Sesamin inhibited cell migration and invasion in FaDu, Ca9-22, and HSC-3 cells and suppressed MMP-2 at noncytotoxic concentrations (0 to 40 μM). Furthermore, sesamin significantly reduced p38 MAPK and JNK phosphorylation in a dose-dependent manner in FaDu and HSC-3 cells. Conclusions: These results indicate that sesamin suppresses the migration and invasion of HNSCC cells by regulating MMP-2 and is thus a potential antimetastatic agent for treating HNSCC.

Licochalcone A induces apoptotic cell death via JNK/p38 activation in human nasopharyngeal carcinoma cells

Licochalcone A is widely studied in different fields and possesses antiasthmatic, antibacterial, anti-inflammatory, antioxidative, and anticancer properties. Its antimalignancy activity on renal, liver, lung, and oral cancer has been explored. However, limited studies have been conducted on the inhibitory effects of licochalcone A in human nasopharyngeal carcinoma cells. We determined cell viability using MTT assay. Cell cycle distribution and apoptotic cell death were measured via flow cytometry. Caspase activation and mitogen-activated protein kinase-related proteins in nasopharyngeal cancer cells in response to licochalcone A were identified by Western blot analysis. Results indicated that licochalcone A reduces cell viability and induces apoptosis, as evidenced by the upregulation of caspase-8 and caspase-9, caspase-3 activation, and cleaved-poly ADP-ribose polymerase expression. Treatment with licochalcone A significantly increases ERK1/2, p38, and JNK1/2 activation. Co-administration of a JNK inhibitor (JNK-IN-8) or p38 inhibitor (SB203580) abolishes the activation of caspase-9, caspase-8, and caspase-3 protein expression during licochalcone A treatment. These findings indicate that licochalcone A exerts a cytostatic effect through apoptosis by targeting the JNK/p38 pathway in human nasopharyngeal carcinoma cells. Therefore, licochalcone A is a promising therapeutic agent for the treatment of human nasopharyngeal cancer cells.

Pinosylvin reduced migration and invasion of oral cancer carcinoma by regulating matrix metalloproteinase-2 expression and extracellular signal-regulated kinase pathway

BACKGROUND

Pinosylvin possesses several biological properties, including anti-inflammatory, antitumor, and antioxidant characteristics. However, the effects of pinosylvin on the migration and invasion of human oral cancer cells and the underlying mechanisms remain unclear.

HYPOTHESIS/PURPOSE

In this research, we investigated the outcome of different concentrations of pinosylvin (0-80 μM) on the metastatic and invasive abilities of SAS, SCC-9, and HSC-3 cells.

METHODS AND RESULTS

Western blotting assay and Gelatin zymography assay indicated that pinosylvin inhibited the enzymatic activity of matrix metalloproteinase-2 (MMP-2) and reduced its protein level but increased the expression of tissue inhibitor of metalloproteinase-2 (TIMP-2). Additionally, the wound healing assay and Transwell method showed that pinosylvin reduced the migration of SAS, SCC-9 and HSC-3 oral cancer cells. Besides, pinosylvin decreased the phosphorylation of ERK1/2 protein experssion in both SAS and SCC-9 cells.

CONCLUSION

These results indicate that pinosylvin is a potential anticancer agent for preventing oral cancer metastasis.

Antimetastatic effects of Eclipta prostrata extract on oral cancer cells

Eclipta prostrata, a traditional Chinese medication, has been used for the treatment of several diseases. However, the molecular mechanism underlying the effects of Eclipta prostrata extracts (EPE) on human oral cancer cell metastasis remains unclear. We thus examined the effects of EPE on metastasis promoting proteins in oral cancer. Our results revealed that the EPE attenuated SCC-9, HSC-3, and TW2.6 cell migration and invasiveness by reducing matrix metalloproteinase (MMP)-2 enzyme activities. In addition, Western blot analysis revealed that EPE significantly reduced the levels of phosphorylated extracellular signal-regulated kinase 1/2 (ERK 1/2) but not those of c-Jun N-terminal kinase (JNK) 1/2 and p38. In conclusion, we found that EPE could inhibit oral cancer metastasis through the inhibition of MMP-2 expression. Therefore, EPE may be used to prevent the metastasis of oral cancer, and has the potential to be applied to cancer treatment.

Coronarin D induces apoptotic cell death through the JNK pathway in human hepatocellular carcinoma

Coronarin D, a diterpene derived from the rhizomes of Hedychium coronarium, has been used to treat inflammatory diseases. Coronarin D can exert strong anticancer effects through cell growth prevention and cell cycle arrest in many cancer cells. In this study, we investigated the molecular mechanism through which coronarin D suppresses cell proliferation and triggers cell death in human hepatocellular carcinoma (HCC) cells. Treatment of Huh7 and Sk-hep-1 cells with coronarin D resulted in a significantly increased loss of mitochondrial membrane potential, leading to the cleavage and activation of caspase-9, caspase-8, and caspase-3 and changes in Bax, Bcl-2, and Bcl-xL protein levels. Coronarin D significantly induced autophagy by increasing the expression of Beclin-1 and LC3-II and reducing the expression of p62. Moreover, Huh7 and Sk-hep-1 cells exposed to coronarin D had decreased expression of phosphorylated AKT, p38, and ERK and increased expression of phosphorylated JNK. Exposure of cells to the JNK-specific inhibitor SP600125 attenuated the apoptotic effects of coronarin D. Taken together, this is the first study to report that coronarin D may effectively inhibit cell growth through apoptosis. We have provided evidence indicating that coronarin D induces cell death through the upregulation of JNK mitogen-activated protein kinases in human HCC cells.

Isolation and Structural Characterization of Bioactive Molecules on Prostate Cancer from Mayan Traditional Medicinal Plants

Prostate cancer is the most common cancer in men around the world. It is a complex and heterogeneous disease in which androgens and their receptors play a crucial role in the progression and development. The current treatment for prostate cancer is a combination of surgery, hormone therapy, radiation and chemotherapy. Therapeutic agents commonly used in the clinic include steroidal and non-steroidal anti-androgens, such as cyproterone acetate, bicalutamide and enzalutamide. These few agents have multiple adverse effects and are not 100% effective. Several plant compounds and mixtures, including grape seed polyphenol extracts, lycopene and tomato preparations, soy isoflavones, and green tea extracts, have been shown to be effective against prostate cancer cell growth. In vivo activity of some isolated compounds like capsaicin and curcumin was reported in prostate cancer murine models. We prepared a library of plant extracts from traditional Mayan medicine. These plants were selected for their use in the contemporaneous Mayan communities for the treatment of different diseases. The extracts were assessed in a phenotypic screening using LNCaP prostate cancer androgen sensitive cell line, with a fixed dose of 25 μg/mL. MTT assay identified seven out of ten plants with interesting anti-neoplastic activity. Extracts from these plants were subjected to a bioguided fractionation to study their major components. We identified three compounds with anti-neoplastic effects against LNCaP cells, one of which shows selectivity for neoplastic compared to benign cells.

Antimetastatic potentials of salvianolic acid A on oral squamous cell carcinoma by targeting MMP-2 and the c-Raf/MEK/ERK pathway

The metastasis of oral squamous cell carcinoma (OSCC) is one of the most important causes of cancer-related deaths. Thus, various therapeutic strategies have been developed to prevent the metastasis of OSCC. Salvianolic acid A (SAA), a traditional Chinese medicine, has antithrombosis, antiplatelet, anti-inflammation, and antitumor activities. Here, we provide molecular evidence indicating that SAA exerts its antimetastatic effects by markedly inhibiting the invasion and migration of oral squamous SCC-9 and SCC-25 cells. SCC-9 and SCC-25 cells were treated with various concentrations of SAA to further investigate the precise involvement of SAA in cancer metastasis. The results of zymography, and Western blotting indicated that SAA treatment may decrease matrix metallopoteinase-2 (MMP-2) expression. SAA also inhibited p-c-Raf, p-MEK1/2, and p-ERK1/2 protein expression. In addition, treating SCC-9 cells with U0126, a MEK-specific inhibitor, decreased MMP-2 expression and concomitantly inhibited cell migration. Our findings suggested that SAA inhibits the invasion and migration of OSCC by inhibiting the c-Raf/MEK/ERK pathways that control MMP-2 expression. Our findings provide new insights into the molecular mechanisms that underlie the antimetastatic effect of SAA and are thus valuable for the development of treatment strategies for metastatic OSCC.

Tricetin suppresses human oral cancer cell migration by reducing matrix metalloproteinase-9 expression through the mitogen-activated protein kinase signaling pathway

Tricetin is a flavonoid derivative and a potent anti-inflammatory and anticancer agent. However, the molecular mechanism underlying the effects of tricetin on human oral cancer cell migration remains unclear. The cell migration and invasion abilities of three oral cancer cell lines (SCC-9, HSC-3, and OECM-1) were analyzed using Boyden chamber migration assays. Our results demonstrated that tricetin attenuates 12-O-tetradecanoylphorbol-13-acetate-induced SCC-9, HSC-3, and OECM-1 cell invasiveness and migration by reducing matrix metalloproteinase (MMP)-9 enzyme activity. The reverse transcription polymerase chain reaction and luciferase reporter assay revealed that tricetin downregulates the mRNA expression and promoter activity of MMP-9. In addition, Western blot analysis revealed that tricetin significantly reduced the levels of phosphorylated c-Jun N-terminal kinase (JNK) 1/2 and p38 levels but not those of extracellular signal-regulated kinase 1/2. In conclusion, this study demonstrated that tricetin suppresses MMP-9 enzymatic activity by downregulating the p38/JNK1/2 pathway and might be a beneficial chemopreventive agent.

Antimetastatic effects of Rheum palmatum L. extract on oral cancer cells

Rheum palmatum L., a traditional Chinese medication, has been used for the treatment of various disorders. However, the detailed impacts and underlying mechanisms of R. palmatum L. extracts (RLEs) on human oral cancer cell metastasis are still unclear. Here, we tested the hypothesis that an RLE has antimetastatic effects on SCC-9 and SAS human oral cancer cells. Gelatin zymography, Western blot, real-time polymerase chain reaction, and luciferase assay were used to explore the underlying mechanisms involved in the antimetastatic effects on oral cancer cells. Our results revealed that the RLE (up to 20 μg/mL, without cytotoxicity) attenuated SCC-9 and SAS cell motility, invasiveness, and migration by reducing matrix metalloproteinase (MMP)-2 enzyme activities. Western blot analysis of the MAPK signaling pathway indicated that the RLE significantly decreased phosphorylated ERK1/2 levels but not p38 and JNK levels. In conclusion, RLEs exhibit antimetastatic activity against oral cancer cells through the transcriptional repression of MMP-2 via the Erk1/2 signaling pathways. Thus, RLEs may be potentially useful as antimetastatic agents for oral cancer chemotherapy.

Melatonin as a potential inhibitory agent in head and neck cancer

Melatonin is a molecule secreted by the pineal gland; it is an important regulator of sleep and circadian rhythms. Through multiple interrelated mechanisms, melatonin exhibits various inhibitory properties at different stages of tumor progression. Many studies have explored the oncostatic effects of melatonin on hormone-dependent tumors. In this review, we highlight recent advances in understanding the effects of melatonin on the development of head and neck cancers, including molecular mechanisms identified through experimental and clinical observations. Because melatonin exerts a wide range of effects, melatonin may influence many mechanisms that influence the development of cancer. These include cell proliferation, apoptosis, angiogenesis, extracellular matrix remodeling through matrix metalloproteinases, and genetic polymorphism. Thus, the evidence discussed in this article will serve as a basis for basic and clinical research to promote the use of melatonin for understanding and controlling the development of head and neck cancers.