Chemopreventive Activity of Systemically Administered Curcumin on Oral Cancer in the 4-Nitroquinoline 1-Oxide Model

A systematic review and meta-analysis of the impact of resveratrol on oral cancer: potential therapeutic implications

The present study aimed to investigate the impact of resveratrol on oral neoplastic parameters through a systematic review and meta-analysis. Resveratrol, a naturally occurring polyphenol, has shown promising potential as a therapeutic agent in various cancer types, including oral neoplasms. Understanding the collective findings from existing studies can shed light on the efficacy and mechanisms of resveratrol in oral cancer management. The systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search was performed to identify relevant studies from various databases, registers, websites, and citation searches. The inclusion criteria encompassed in-vivo studies investigating the impact of resveratrol on oral neoplastic parameters in animal models. After screening and assessment, a total of five eligible studies were included in the meta-analysis. The meta-analysis of the selected studies revealed that resveratrol treatment exhibited a potential impact on reducing oral neoplastic proliferation and promoting neoplastic apoptosis. The combined analysis showed a statistically significant decrease in neoplastic parameters with an overall effect size (ES) of 0.85 (95% CI: [0.74, 0.98]). Subgroup analyses were conducted to explore potential variations among different cellular types and exposure compounds, providing further insights into the efficacy of resveratrol in specific contexts. This systematic review and meta-analysis support the potential of resveratrol as a promising therapeutic agent in oral cancer management. The findings indicate that resveratrol may effectively modulate neoplastic proliferation and apoptosis in various cellular types within animal models of oral cancer. However, further well-controlled studies and clinical trials are warranted to validate these observations and elucidate the underlying mechanisms of resveratrol's actions. Resveratrol holds promise as a complementary therapeutic approach in the prevention and treatment of oral neoplastic conditions.

Therapeutic potential of curcumin and its nanoformulations for treating oral cancer

The global incidence of oral cancer has steadily increased in recent years and is associated with high morbidity and mortality. Oral cancer is the most common cancer in the head and neck region, and is predominantly of epithelial origin (i.e. squamous cell carcinoma). Oral cancer treatment modalities mainly include surgery with or without radiotherapy and chemotherapy. Though proven effective, chemotherapy has significant adverse effects with possibilities of tumor resistance to anticancer drugs and recurrence. Thus, there is an imperative need to identify suitable anticancer therapies that are highly precise with minimal side effects and to make oral cancer treatment effective and safer. Among the available adjuvant therapies is curcumin, a plant polyphenol isolated from the rhizome of the turmeric plant Curcuma longa. Curcumin has been demonstrated to have anti-infectious, antioxidant, anti-inflammatory, and anticarcinogenic properties. Curcumin has poor bioavailability, which has been overcome by its various analogues and nanoformulations, such as nanoparticles, liposome complexes, micelles, and phospholipid complexes. Studies have shown that the anticancer effects of curcumin are mediated by its action on multiple molecular targets, including activator protein 1, protein kinase B (Akt), nuclear factor κ-light-chain-enhancer of activated B cells, mitogen-activated protein kinase, epidermal growth factor receptor (EGFR) expression, and EGFR downstream signaling pathways. These targets play important roles in oral cancer pathogenesis, thereby making curcumin a promising adjuvant treatment modality. This review aims to summarize the different novel formulations of curcumin and their role in the treatment of oral cancer.

Digesting the Role of JAK-STAT and Cytokine Signaling in Oral and Gastric Cancers

When small proteins such as cytokines bind to their associated receptors on the plasma membrane, they can activate multiple internal signaling cascades allowing information from one cell to affect another. Frequently the signaling cascade leads to a change in gene expression that can affect cell functions such as proliferation, differentiation and homeostasis. The Janus kinase-signal transducer and activator of transcription (JAK-STAT) and the tumor necrosis factor receptor (TNFR) are the pivotal mechanisms employed for such communication. When deregulated, the JAK-STAT and the TNF receptor signaling pathways can induce chronic inflammatory phenotypes by promoting more cytokine production. Furthermore, these signaling pathways can promote replication, survival and metastasis of cancer cells. This review will summarize the essentials of the JAK/STAT and TNF signaling pathways and their regulation and the molecular mechanisms that lead to the dysregulation of the JAK-STAT pathway. The consequences of dysregulation, as ascertained from founding work in haematopoietic malignancies to more recent research in solid oral-gastrointestinal cancers, will also be discussed. Finally, this review will highlight the development and future of therapeutic applications which modulate the JAK-STAT or the TNF signaling pathways in cancers.

Systemic Dietary Hesperidin Modulation of Osteoclastogenesis, Bone Homeostasis and Periodontal Disease in Mice

This study aimed to evaluate the effects of hesperidin (HE) on in vitro osteoclastogenesis and dietary supplementation on mouse periodontal disease and femoral bone phenotype. RAW 264.7 cells were stimulated with RANKL in the presence or absence of HE (1, 100 or 500 µM) for 5 days, and evaluated by TRAP, TUNEL and Western Blot (WB) analyses. In vivo, C57BL/6 mice were given HE via oral gavage (125, 250 and 500 mg/kg) for 4 weeks. A sterile silk ligature was placed between the first and second right maxillary molars for 10 days and microcomputed tomography (μCT), histopathological and immunohistochemical evaluation were performed. Femoral bones subjected or not to dietary HE (500 mg/kg) for 6 and 12 weeks were evaluated using μCT. In vitro, HE 500 µM reduced formation of RANKL-stimulated TRAP-positive(+) multinucleated cells (500 µM) as well as c-Fos and NFATc1 protein expression (p < 0.05), markers of osteoclasts. In vivo, dietary HE 500 mg/kg increased the alveolar bone resorption in ligated teeth (p < 0.05) and resulted in a significant increase in TRAP+ cells (p < 0.05). Gingival inflammatory infiltrate was greater in the HE 500 mg/kg group even in the absence of ligature. In femurs, HE 500 mg/kg protected trabecular and cortical bone mass at 6 weeks of treatment. In conclusion, HE impaired in vitro osteoclastogenesis, but on the contrary, oral administration of a high concentration of dietary HE increased osteoclast numbers and promoted inflammation-induced alveolar bone loss. However, HE at 500 mg/kg can promote a bone-sparing effect on skeletal bone under physiological conditions.

Resveratrol effects in oral cancer cells: a comprehensive review

Oral cancer is a very common tumor worldwide with high incidence and mortality. The treatment of oral cancer involves surgery, radio- and chemotherapy; however, high failure rates and toxicity are noticed. Thus, the search of new drugs aiming a more effective treatment is welcomed. Natural products present chemopreventive and anti-cancer effects. Resveratrol is a naturally occurring antioxidant that contains several health benefits, including anti-inflammatory and antiproliferative activities. This review discusses the different action mechanisms of resveratrol related in the in vitro and in vivo studies using models of oral cancer.

Therapeutic Effects of Curcumin against Bladder Cancer: A Review of Possible Molecular Pathways

There are concerns about the increased incidence of cancer both in developing and developed countries. In spite of recent progress in cancer therapy, this disease is still one of the leading causes of death worldwide. Consequently, there have been rigorous attempts to improve cancer therapy by looking at nature as a rich source of naturally occurring anti-tumor drugs. Curcumin is a well-known plant-derived polyphenol found in turmeric. This compound has numerous pharmacological effects such as antioxidant, anti-inflammatory, antidiabetic and anti-tumor properties. Curcumin is capable of suppressing the growth of a variety of cancer cells including those of bladder cancer. Given the involvement of various signaling pathways such as PI3K, Akt, mTOR and VEGF in the progression and malignancy of bladder cancer, and considering the potential of curcumin in targeting signaling pathways, it seems that curcumin can be considered as a promising candidate in bladder cancer therapy. In the present review, we describe the molecular signaling pathways through which curcumin inhibits invasion and metastasis of bladder cancer cells.

From Simple Mouth Cavities to Complex Oral Mucosal Disorders-Curcuminoids as a Promising Therapeutic Approach

Oral diseases are among the most common encountered health issues worldwide, which are usually associated with anomalies of the oral cavity, jaws, and salivary glands. Despite the availability of numerous treatment modalities for oral disorders, a limited clinical response has been observed because of the inefficacy of the drugs and countless adverse side effects. Therefore, the development of safe, efficacious, and wide-spectrum therapeutics is imperative in the battle against oral diseases. Curcumin, extracted from the golden spice turmeric, is a well-known natural polyphenol that has been extensively studied for its broad pleiotropic attributes and its ability to modulate multiple biological processes. It is well-documented to target pro-inflammatory mediators like NF-κB, ROS, COX-2, IL-1, IL-2, TGF-β, growth factors, apoptotic proteins, receptors, and various kinases. These properties make curcumin a promising nutraceutical in the treatment of many oral diseases like oral submucous fibrosis, oral mucositis, oral leukoplakia, oral erythroplakia, oral candidiasis, aphthous stomatitis, oral lichen planus, dental caries, periodontitis, and gingivitis. Numerous in vitro and in vivo studies have shown that curcumin alleviates the symptoms of most of the oral complications, including the inhibition of the progression of oral cancer. In this regard, many clinical trials have been completed, and many are ongoing to investigate the "curcumin effect" in oral maladies. Therefore, the current review delineates the mechanistic framework of curcumin's propensity in curbing oral diseases and present outcomes of the clinical trials of curcumin-based therapeutics that can provide a breakthrough in the clinical management of these diseases.

Updated Review on the Role of Curcumin in Gastrointestinal Cancers

Malignant conditions of the gastrointestinal tract and accessory organs of digestion, including the oral cavity, esophagus, stomach, biliary system, pancreas, small intestine, large intestine, rectum and anus, are referred to as gastrointestinal cancers. Curcumin is a natural compound derived from turmeric with a wide range of biological activities. Several in vitro and in vivo studies have investigated the effects of curcumin on gastrointestinal cancers. In the current review, we aimed to provide an updated summary on the recent findings regarding the beneficial effects of curcumin on different gastrointestinal cancers in the recent decade. For this purpose, ScienceDirect," "Google Scholar," "PubMed," "ISI Web of Knowledge," and "Wiley Online Library" databases were searched using "curcumin", "cancer", and "gastrointestinal organs" as keywords. In vitro studies performed on different gastrointestinal cancerous cell lines have shown that curcumin can inhibit cell growth through cycle arrest at the G2/M and G1 phases, as well as stimulated apoptosis and autophagy by interacting with multiple molecular targets. In vivo studies performed in various animal models have confirmed mainly the chemopreventive effects of curcumin. Several nano-formulations have been proposed to improve the bioavailability of curcumin and increase its absorption. Moreover, curcumin has been used in combinations with many anti-tumor drugs to increase their anticarcinogenic properties. Taken together, curcumin falls within the category of plant-derived substances capable of preventing or treating gastrointestinal cancers. Further studies, particularly clinical trials, on the efficacy and safety of curcumin are suggested in this regard.

Antitumor Activity of Ficus deltoidea Extract on Oral Cancer: An In Vivo Study

Background

The aim of this study is to evaluate the chemopreventive and chemotherapeutic activities of Ficus deltoidea (FD) in an animal model induced for oral cancer using 4-nitroquinoline-1-oxide (4NQO).

Methods

Male Sprague-Dawley (SD) rats were randomized into six groups (n = 7 per group): Group 1 (untreated group); Group 2 (control cancer group) received 4NQO only for 8 weeks in their drinking water; Groups 3 and 4 (chemopreventive) received 4NQO for 8 weeks and were simultaneously treated with FD extract at 250 and 500 mg/kg, respectively, by oral gavage; Groups 5 and 6 (chemotherapeutic) received 4NQO for 8 weeks followed by the administration of FD extract at 250 and 500 mg/kg, respectively, for another 10 weeks. The incidence of oral cancer was microscopically evaluated. Moreover, immunohistochemical expression was analysed in tongue specimens using an image analyser computer system, while the RT² profiler PCR array method was employed for gene expression analysis.

Results

The results of the present study showed a beneficial regression effect of the FD extract on tumor progression. The FD extract significantly reduced the incidence of oral squamous cell carcinoma (OSCC) from 100% to 14.3% in the high-dose groups. The immunohistochemical analysis showed that the FD extract had significantly decreased the expression of the key tumor marker cyclin D1 and had significantly increased the expression of the β-catenin and e-cadherin antibodies that are associated with enhanced cellular adhesion. Based on the gene expression analysis, FD extract had reduced the expression of the TWIST1 and RAC1 genes associated with epithelial-mesenchymal transition (EMT) and had significantly downregulated the COX-2 and EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.β-catenin and e-cadherin antibodies that are associated with enhanced cellular adhesion. Based on the gene expression analysis, FD extract had reduced the expression of the TWIST1 and RAC1 genes associated with epithelial-mesenchymal transition (EMT) and had significantly downregulated the COX-2 and EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.TWIST1 and RAC1 genes associated with epithelial-mesenchymal transition (EMT) and had significantly downregulated the COX-2 and EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.RAC1 genes associated with epithelial-mesenchymal transition (EMT) and had significantly downregulated the COX-2 and EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.COX-2 and EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.EGFR genes associated with cancer angiogenesis, metastasis, and chemoresistance. Our data suggest that the FD extract exerts chemopreventive and chemotherapeutic activities in an animal model induced for oral cancer using 4NQO, thus having the potential to be developed as chemopreventive and chemotherapeutic agents.

The E-Cadherin and N-Cadherin Switch in Epithelial-to-Mesenchymal Transition: Signaling, Therapeutic Implications, and Challenges

Epithelial-to-Mesenchymal Transition (EMT) has been shown to be crucial in tumorigenesis where the EMT program enhances metastasis, chemoresistance and tumor stemness. Due to its emerging role as a pivotal driver of tumorigenesis, targeting EMT is of great therapeutic interest in counteracting metastasis and chemoresistance in cancer patients. The hallmark of EMT is the upregulation of N-cadherin followed by the downregulation of E-cadherin, and this process is regulated by a complex network of signaling pathways and transcription factors. In this review, we summarized the recent understanding of the roles of E- and N-cadherins in cancer invasion and metastasis as well as the crosstalk with other signaling pathways involved in EMT. We also highlighted a few natural compounds with potential anti-EMT property and outlined the future directions in the development of novel intervention in human cancer treatments. We have reviewed 287 published papers related to this topic and identified some of the challenges faced in translating the discovery work from bench to bedside.

Epithelial-mesenchymal transition as a target for botanicals in cancer metastasis

BACKGROUND

The plant kingdom represents an unlimited source of phytotherapeutics with promising perspectives in the field of anticancer drug discovery.

PURPOSE

In this view, epithelial-mesenchymal transition (EMT) represents a novel and major target in anticancer therapy. Therefore, this narrative review aims to provide an updated overview on the bioactive phytochemicals with anti-EMT activity.

CONCLUSION

Among the plant products reviewed, phenylpropanoids were the most investigated at preclinical phase, thus exhibiting a promising potential as anticancer drugs, though an evidence-based clinical efficacy is still lacking.

Bioactivity, Health Benefits, and Related Molecular Mechanisms of Curcumin: Current Progress, Challenges, and Perspectives

Curcumin is a principal curcuminoid of turmeric (Curcuma longa), which is commonly used as a spice in cooking and a yellow pigment in the food processing industry. Recent studies have demonstrated that curcumin has a variety of biological activities and pharmacological performances, providing protection and promotion of human health. In addition to presenting an overview of the gut metabolism of curcumin, this paper reviews the current research progress on its versatile bioactivity, such as antioxidant, anti-inflammatory, and immune-regulatory activities, and also intensively discusses its health benefits, including the protective or preventive effects on cancers and diabetes, as well as the liver, nervous system, and cardiovascular systems, highlighting the potential molecular mechanisms. Besides, the beneficial effects of curcumin on human are further stated based on clinical trials. Considering that there is still a debate on the beneficial effects of curcumin, we also discuss related challenges and prospects. Overall, curcumin is a promising ingredient of novel functional foods, with protective efficacy in preventing certain diseases. We hope this comprehensive and updated review will be helpful for promoting human-based studies to facilitate its use in human health and diseases in the future.

Chemoprevention of Head and Neck Cancers: Does It Have Only One Face?

Head and neck squamous cell cancer (HNSCC) represents a significant burden worldwide. Chemoprevention of HNSCC is a means of cancer control with a use of drugs or natural agents in order to hinder or delay the cancer development. The purpose of this article is to review mechanism of action of different chemopreventive agents' groups and results of most important researches concerning them. The safety issues of HNSCC chemoprevention are also discussed. In case of HNSCC there is currently no agent, which would give positive result in the third phase of clinical trials. Promising results of preclinical trials are not always confirmed by further tests. Main problems are low effectiveness, high toxicity, and lack of highly specificity biomarkers for monitoring the research. New trials concerning many agents, as well as novel technologies for provision of pharmaceutical forms of them, including drug nanocarriers, are currently underway, which gives hope for finding the perfect chemopreventive agent formula.

Curcumin inhibits cell proliferation and motility via suppression of TROP2 in bladder cancer cells

Bladder cancer (BC) has become a serious health prob-lem and represents the second most commonly diagnosed urological tumor. Curcumin is a principal active natural component of turmeric and has long been used in Asia as a traditional herbal medicine. Curcumin suppresses cell growth in various types of cancer, including BC, by regulating numerous molecular signaling pathways. The human trophoblast cell surface antigen 2 (Trop2) belongs to the tumor-associated calcium signal transducer gene family. Trop2 has been described as a cancer driver and is deregulated in various types of cancer. However, whether Trop2 is involved in curcumin-induced BC cell inhibition remains to be elucidated. The present study hypothesized that Trop2 may be a promising target of curcumin in BC cells. It was found that Trop2 was closely involved in curcumin-induced cell proliferation suppression, mobility inhibition, apoptosis, and cell cycle arrest in BC cells. Curcumin decreased the expression of Trop2 and its downstream target cyclin E1, and increased the level of p27. The overexpression of Trop2 enhanced the oncogenic activity of BC cells, whereas downregulation of the expression of Trop2 suppressed cell proliferation and mobility, increased apoptosis, and sensitized BC cells to curcumin treatment. Therefore, Trop2 may be a promising target of curcumin in BC cells and the inhibition of Trop2 may be an important method for the therapeutic management of patients with BC.

Curcumin reverses tobacco smoke‑induced epithelial‑mesenchymal transition by suppressing the MAPK pathway in the lungs of mice

Tobacco smoke is a major risk factor for lung cancer. Epithelial‑mesenchymal transition (EMT) is decisive in cancer invasion and metastasis, and therefore promotes cancer progression. Mitogen‑activated protein kinase (MAPK) pathways are implicated in various aspects of cancer development and progression, including the EMT process. The chemopreventive effect of curcumin on carcinogenesis has been reported in vivo and in vitro. The present study investigated tobacco smoke‑induced alterations in the MAPK/activator protein‑1 (AP‑1) pathways, and pulmonary EMT changes in the lungs of mice, and further observed the chemopreventive effect of curcumin. The protein expression levels analyzed by western blot analysis demonstrated that 12 weeks of tobacco smoke exposure activated extracellular‑signal‑regulated kinase (ERK) 1/2, c‑Jun N‑terminal kinase (JNK) and p38 MAPK pathways, in addition to AP‑1, in the lungs of mice, while reducing the activation of ERK5/MAPK pathways. The results also indicated that the mRNA and protein levels of the epithelial markers E‑cadherin and zona occludens‑1 were reduced following tobacco smoke exposure. Conversely, the expression levels of mRNA and protein for the mesenchymal markers vimentin and N‑cadherin were increased. Curcumin treatment inhibited tobacco smoke‑induced MAPK/AP‑1 activation, including ERK1/2, JNK and p38 MAPK pathways, and AP‑1 proteins, and reversed EMT alterations in lung tissue. The results of the present study provide new insights into the molecular mechanisms of tobacco smoke‑associated lung cancer and may open up new avenues in the search for potential therapeutic targets in lung tumorigenesis.

Grape seed proanthocyanidins inhibit the proliferation, migration and invasion of tongue squamous cell carcinoma cells through suppressing the protein kinase B/nuclear factor-κB signaling pathway

Tongue squamous cell carcinoma (TSCC) is the most common oral squamous cell carcinoma. Despite significant advances in combined therapies, the 5-year survival rate of patients with TSCC has not notably improved; this is due to regional recurrences and lymph node metastasis. Grape seed proanthocyanidins (GSPs) are consumed as dietary supplements worldwide and possess anticancer activity against several different types of cancer. However, their effect on TSCC and the underlying mechanisms by which they function remain unclear. In the present study, it was identified that GSPs significantly inhibited the viability and induced the apoptosis of Tca8113 cells in a dose-dependent manner. This was associated with a significantly increased expression of the pro-apoptosis regulator BAX protein and a significantly decreased expression of the anti-apoptosis regulator Bcl-2 protein at 100 µg/ml GSPs. In addition, at non-toxic concentrations GSPs significantly inhibited the secretion of matrix metalloproteinase-2 (MMP-2) and MMP-9 from Tca8113 cells, as well as their migration and invasion. Furthermore, it was demonstrated that GSPs significantly inhibited the phosphorylation of protein kinase B (Akt) and IκB kinase, as well as the translocation of nuclear factor-κB (NF-κB) into the nucleus of Tca8113 cells. Taken together, these results suggest that GSPs inhibit the proliferation, migration and invasion of Tca8113 cells through suppression of the Akt/NF-κB signaling pathway. This indicates that GSPs may be developed as a novel potential chemopreventive agent against TSCC.

Cucurmin, anticancer, & antitumor perspectives: A comprehensive review

Cucurmin, a naturally yellow component isolated from turmeric, ability to prevent various life-style related disorders. The current review article mainly emphasizes on different anticancer perspectives of cucurmin, i.e., colon, cervical, uterine, ovarian, prostate head and neck, breast, pulmonary, stomach and gastric, pancreatic, bladder oral, oesophageal, and bone cancer. It holds a mixture of strong bioactive molecule known as cucurminoids that has ability to reduce cancer/tumor at initial, promotion and progression stages of tumor development. In particular, these compounds block several enzymes required for the growth of tumors and may therefore involve in tumor treatments. Moreover, it modulates an array of cellular progressions, i.e., nitric oxide synthetase activity, protein kinase C activity, epidermal growth factor (EGF) receptor intrinsic kinase activity, nuclear factor kappa (NF-kB) activity, inhibiting lipid peroxidation and production of reactive oxygen species. However, current manuscript summarizes most of the recent investigations of cucurmin but still further research should be conducted to explore the role of curcumin to mitigate various cancers.

Effects of Curcumin on Tobacco Smoke-induced Hepatic MAPK Pathway Activation and Epithelial-Mesenchymal Transition In Vivo

Tobacco smoke is a major risk factor for hepatic cancer. Epithelial-mesenchymal transition (EMT) induced by tobacco smoke is crucially involved in the initiation and development of cancer. Mitogen-activated protein kinase (MAPK) pathways play important roles in tobacco smoke-associated carcinogenesis including EMT process. The chemopreventive effect of curcumin supplementation against cancers has been reported. In this study, we investigated the effects of tobacco smoke on MAPK pathway activation and EMT alterations, and then the preventive effect of curcumin was examined in the liver of BALB/c mice. Our results indicated that exposure of mice to tobacco smoke for 12 weeks led to activation of ERK1/2, JNK, p38 and ERK5 pathways as well as activator protein-1 (AP-1) proteins in liver tissue. Exposure of mice to tobacco smoke reduced the hepatic mRNA and protein expression of the epithelial markers, while the hepatic mRNA and protein levels of the mesenchymal markers were increased. Treatment of curcumin effectively attenuated tobacco smoke-induced activation of ERK1/2 and JNK MAPK pathways, AP-1 proteins and EMT alterations in the mice liver. Our data suggested the protective effect of curcumin in tobacco smoke-triggered MAPK pathway activation and EMT in the liver of BALB/c mice, thus providing new insights into the chemoprevention of tobacco smoke-associated hepatic cancer. Copyright © 2017 John Wiley & Sons, Ltd.

Curcumin Sensitizes Silymarin to Exert Synergistic Anticancer Activity in Colon Cancer Cells

We studied combinatorial interactions of two phytochemicals, curcumin and silymarin, in their action against cancer cell proliferation. Curcumin is the major component of the spice turmeric. Silymarin is a bioactive component of milk thistle used as a protective supplement against liver disease. We studied antiproliferative effects of curcumin alone, silymarin alone and combinations of curcumin and silymarin using colon cancer cell lines (DLD-1, HCT116, LoVo). Curcumin inhibited colon cancer cell proliferation in a concentration-dependent manner, whereas silymarin showed significant inhibition only at the highest concentrations assessed. We found synergistic effects when colon cancer cells were treated with curcumin and silymarin together. The combination treatment led to inhibition of colon cancer cell proliferation and increased apoptosis compared to single compound treated cells. Combination treated cells exhibited marked cell rounding and membrane blebbing of apoptotic cells. Curcumin treated cells showed 3-fold more caspase3/7 activity whereas combination treated cells showed 5-fold more activity compared to control and silymarin treated cells. When DLD-1 cells were pre-exposed to curcumin, followed by treatment with silymarin, the cells underwent a high amount of cell death. The pre-exposure studies indicated curcumin sensitization of silymarin effect. Our results indicate that combinatorial treatments using phytochemicals are effective against colorectal cancer.

STAT3 as a Chemoprevention Target in Carcinogen-Induced Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a frequently fatal disease due, in large part, to a high rate of second primary tumor (SPT) formation. The 4-nitroquinoline 1-oxide (4-NQO) mouse model of oral carcinogenesis provides a robust system in which to study chemopreventive agents in the context of chemically induced HNSCC tumors. STAT3 is a potent oncogene that is hyperactivated by tyrosine phosphorylation early in HNSCC carcinogenesis and is a rational therapeutic target. We recently reported that loss-of-function of the STAT3 phosphatase PTPRT promotes STAT3 activation in HNSCC tumors and preclinical models and may serve as a predictive biomarker of response to STAT3 inhibitors, including the small-molecule Stattic. We therefore investigated the hypothesis that Ptprt-knockout (KO) mice would be more susceptible to 4-NQO-induced oral carcinogenesis and more sensitive to Stattic-mediated chemoprevention compared with wild-type (WT) mice. Herein, we demonstrate that Ptprt WT and KO mice develop similar spectra of HNSCC disease severity upon 12 weeks of 4-NQO administration, with no apparent effect of Ptprt genotype on carcinogenesis or treatment outcome. Targeting of STAT3 with Stattic resulted in a chemopreventive effect against 4-NQO-induced oral cancer (P = 0.0402). While these results do not support a central role for PTPRT in 4-NQO-induced HNSCC carcinogenesis, further investigation of STAT3 as a chemoprevention target in this cancer is warranted. Cancer Prev Res; 9(8); 657-63. ©2016 AACR.

Modulatory Effect of Taurine on 7,12-Dimethylbenz(a)Anthracene-Induced Alterations in Detoxification Enzyme System, Membrane Bound Enzymes, Glycoprotein Profile and Proliferative Cell Nuclear Antigen in Rat Breast Tissue

The modulatory effect of taurine on 7,12-dimethylbenz(a)anthracene (DMBA)-induced breast cancer in rats was studied. DMBA (25 mg/kg body weight) was administered to induce breast cancer in rats. Protein carbonyl levels, activities of membrane bound enzymes (Na(+) /K(+) ATPase, Ca(2+) ATPase, and Mg(2+) ATPase), phase I drug metabolizing enzymes (cytochrome P450, cytochrome b5, NADPH cytochrome c reductase), phase II drug metabolizing enzymes (glutathione-S-transferase and UDP-glucuronyl transferase), glycoprotein levels, and proliferative cell nuclear antigen (PCNA) were studied. DMBA-induced breast tumor bearing rats showed abnormal alterations in the levels of protein carbonyls, activities of membrane bound enzymes, drug metabolizing enzymes, glycoprotein levels, and PCNA protein expression levels. Taurine treatment (100 mg/kg body weight) appreciably counteracted all the above changes induced by DMBA. Histological examination of breast tissue further supported our biochemical findings. The results of the present study clearly demonstrated the chemotherapeutic effect of taurine in DMBA-induced breast cancer.