Progress in chemoprevention drug development: the promise of molecular biomarkers for prevention of intraepithelial neoplasia and cancer--a plan to move forward

Phase IIa Clinical Biomarker Trial of Dietary Arginine Restriction and Aspirin in Colorectal Cancer Patients

After potentially curative treatment, colorectal cancer (CRC) patients remain at high risk for recurrence, second primary CRC, and high-risk adenomas. In combination with existing data, our previous findings provide a rationale for reducing tissue polyamines as tertiary prevention in non-metastatic CRC patients. The goal of this study was to demonstrate rectal tissue polyamine reduction in optimally treated stage I-III CRC patients after intervention with daily oral aspirin + dietary arginine restriction. A single-institution phase IIa clinical trial was conducted. Patients were treated with aspirin 325 mg/day and an individualized dietary regimen designed to reduce arginine intake by ≥30% over a 12-week study period. Dietary intake, endoscopy with rectal biopsies, and phlebotomy were performed pre- and post-intervention. The primary endpoint was to demonstrate ≥50% decrease in rectal tissue putrescine levels from baseline as a measure of polyamine reduction in the target tissue. Twenty eligible patients completed the study. After study intervention, mean dietary arginine intake decreased from 3.7 g/day ± 1.3 SD to 2.6 g/day ± 1.2 SD (29.7% decrease, p < 0.02 by Sign test). Mean plasma arginine levels decreased from 46.0 ng/mL ± 31.5 SD at baseline to 35 ng/mL ± 21.7 SD (p < 0.001). Rectal tissue putrescine levels were 0.90 nMol/mg-protein pre-intervention and 0.99 nMol/mg-protein post-intervention (p < 0.64, NS). No significant differences were observed for the other tissue polyamines investigated: spermidine (p < 0.13), spermine (p < 0.21), spermidine:spermine ratio (p < 0.71). Among CRC survivors, treatment with daily oral aspirin and an individualized dietary arginine restriction intervention resulted in lower calculated dietary arginine intake and plasma arginine levels but did not affect rectal tissue polyamine levels.

Engineers in Medicine: Foster Innovation by Traversing Boundaries

Engineers play a critical role in the advancement of biomedical science and the development of diagnostic and therapeutic technologies for human well-being. The complexity of medical problems requires the synthesis of diverse knowledge systems and clinical experiences to develop solutions. Therefore, engineers in the healthcare and biomedical industries are interdisciplinary by nature to innovate technical tools in sophisticated clinical settings. In academia, engineering is usually divided into disciplines with dominant characteristics. Since biomedical engineering has been established as an independent curriculum, the term "biomedical engineers" often refers to the population from a specific discipline. In fact, engineers who contribute to medical and healthcare innovations cover a broad range of engineering majors, including electrical engineering, mechanical engineering, chemical engineering, industrial engineering, and computer sciences. This paper provides a comprehensive review of the contributions of different engineering professions to the development of innovative biomedical solutions. We use the term "engineers in medicine" to refer to all talents who integrate the body of engineering knowledge and biological sciences to advance healthcare systems.

Effects of Combined Pentadecanoic Acid and Tamoxifen Treatment on Tamoxifen Resistance in MCF−7/SC Breast Cancer Cells

Estrogen receptors are indicators of breast cancer adaptability to endocrine therapies, such as tamoxifen. Deficiency or absence of estrogen receptor α (ER−α) in breast cancer cells results in reduced efficacy of endocrine therapy. Here, we investigated the effect of combined tamoxifen and pentadecanoic acid therapy on ER−α−under−expressing breast cancer cells. Drug resistance gene expression patterns were determined by RNA sequencing analysis and in vitro experiments. For the first time, we demonstrate that the combined treatment of pentadecanoic acid, an odd−chain fatty acid, and tamoxifen synergistically suppresses the growth of human breast carcinoma MCF−7 stem cells (MCF−7/SCs), which were found to be tamoxifen−resistant and showed reduced ER−α expression compared with the parental MCF−7 cells. In addition, the combined treatment synergistically induced apoptosis and accumulation of sub−G1 cells and suppressed epithelial−to−mesenchymal transition (EMT). Exposure to this combination induces re−expression of ER−α at the transcriptional and protein levels, along with suppression of critical survival signal pathways, such as ERK1/2, MAPK, EGFR, and mTOR. Collectively, decreased ER−α expression was restored by pentadecanoic acid treatment, resulting in reversal of tamoxifen resistance. Overall, pentadecanoic acid exhibits the potential to enhance the efficacy of endocrine therapy in the treatment of ER−α−under−expressing breast cancer cells.

Ketamine induction of physiological functions alterations in Caenorhabditis elegans by chronic and multigenerational exposure and corresponding aquatic environmental risk assessment

Although ketamine (KET) has been widely detected in aquatic environments, the ecotoxicity data in aquatic invertebrates and associated risk remained unclear. This study aimed to investigate the adverse effects on benthos (Caenorhabditis elegans (C.elegans)) posed by KET from chronic (10 days) and multigenerational (four generations) exposure. Such exposure induced dose-dependent alterations on apoptosis, reactive oxygen species (ROS) induction, locomotion activity, feeding rate, chemotaxis, and brood size of nematodes, showing a cumulative damage through generations. KET posed vulva deformations and worm bags of C. elegans with a dosed-dependent increase. As a consequence, the fecundity and viability of worms would be impaired, which could eventually impact aquatic ecosystem equilibrium. Meanwhile, the bioactivation/detoxification process of xenobiotics and longevity regulating pathway induced by KET might be responsible for the physiological function disorders. Accordingly, the risk quotients (RQ) of KET in surface water in China were calculated using the 90% indicator protection concentration (C_0.1) derived from multiple toxicity indicators cumulative analyses. The results would be more objective considering numerous biomarkers changes of one species in comparison with traditional method using no observed effect concentrations (NOEC) of teratogenesis. The risk in surface water in southern China was up to high level (RQ > 1), suggesting long-term monitoring was imperative.

A grant-based experiment to train clinical investigators: the AACR/ASCO methods in clinical cancer research workshop

To address the need for clinical investigators in oncology, AACR and ASCO established the Methods in Clinical Cancer Research Workshop (MCCRW). The workshop's objectives were to: (1) provide training in the methods, design, and conduct of clinical trials; (2) ensure that clinical trials met federal and international ethical guidelines; (3) evaluate the effectiveness of the workshop; and (4) create networking opportunities for young investigators with mentoring senior faculty. Educational methods included: (1) didactic lectures; (2) Small Group Discussion Sessions; (3) Protocol Development Groups; (4) one-on-one mentoring. Learning focused on the development of an IRB-ready protocol, which was submitted on the last day of the workshop. Evaluation methods included: (1) pre- and post-workshop tests; (2) students' workshop evaluations; (3) faculty's ratings of protocol development; (4) students' productivity in clinical research after the workshop; (5) an independent assessment of the workshop. From 1996-2014, 1932 students from diverse backgrounds attended the workshop. There was a significant improvement in the students' level of knowledge from the pre- to the post-workshop exams (p < 0.001). Across the classes, student evaluations were very favorable. At the end of the workshop, faculty rated 92-100% of the students' protocols as ready for IRB submission. Intermediate and long-term follow-ups indicated that more than 92% of students were actively involved in patientrelated research, and 66% had implemented five or more protocols. This NCI-sponsored MCCRW has had a major impact on the training of clinicians in their ability to design and implement clinical trials in cancer research.

Theobromacacao Criollo var. Beans: Biological Properties and Chemical Profile

Theobroma cacao provides precious products such as polyphenol-rich beans that are useful for nutraceutical purposes. The geographical area may influence the chemical composition of raw cocoa beans in terms of the polyphenols and biological qualities of the products. This work aimed to investigate the biological properties and the chemical composition of two different samples of Criollo var. cocoa raw beans coming from two areas (Indonesia; Peru). Beans underwent biphasic extraction obtaining lipophilic and hydroalcoholic extracts. The extracts were tested for antiradical, antimutagenic, and antigenotoxic effects. Cell viability inhibition toward breast, gastric/esophageal colorectal adenocarcinoma, and hepatoblastoma human cell lines was evaluated. Extracts were chemically investigated through UV-Vis spectroscopy and ultra-high-pressure liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QqTOF MS/MS). Results showed that the Indonesian bean hydroalcoholic extracts were able to scavenge 2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) cation radical better than the Peruvian hydroalcoholic extracts (ECs₅₀: 72.63 vs. 322.20 μg/mL). Extracts showed antimutagenic and antigenotoxic activity. The viability inhibitory effect on breast and hepatic cancer cells was reached only for the Indonesian hydroalcoholic extracts at hundreds of μg/mL. Phenylpropenoyl-L-amino acids, hydroxycinnamoyl aminoacids conjugates, and procyanidin compounds were found mainly in the hydroalcoholic extracts, whereas fatty acids and lyso-phospholipids were found mainly in lipophilic fractions. Fatty acid and (epi)catechins appeared to be affected by different environmental conditions of the geographical areas.

Assessing the Current State of Lung Cancer Chemoprevention: A Comprehensive Overview

Chemoprevention of lung cancer is thought to significantly reduce the risk of acquiring these conditions in the subpopulation of patients with underlying health issues, such as chronic obstructive pulmonary disorder and smoking-associated lung problems. Many strategies have been tested in the previous decades, with very few translating to successful clinical trials in specific subpopulations of patients. In this review, we analyze these strategies, as well as new approaches that have emerged throughout the last few years, including synthetic lethality concept and microbiome-induced regulation of lung carcinogenesis. Overall, the continuous effort in the area of lung chemoprevention is required to develop practical therapeutical approaches. Given the inconsistency of results obtained in clinical trials targeting lung cancer chemoprevention in various subgroups of patients that differ in the underlying health condition, race, and gender, we believe that individualized approaches will have more promise than generalized treatments.

A Phase IIa Trial of Metformin for Colorectal Cancer Risk Reduction among Individuals with History of Colorectal Adenomas and Elevated Body Mass Index

Obesity is associated with risk of colorectal adenoma (CRA) and colorectal cancer. The signaling pathway activated by metformin (LKB1/AMPK/mTOR) is implicated in tumor suppression in Apc^Min/+ mice via metformin-induced reduction in polyp burden, increased ratio of pAMPK/AMPK, decreased pmTOR/mTOR ratio, and decreased pS6^Ser235/S6^Ser235 ratio in polyps. We hypothesized that metformin would affect colorectal tissue S6^Ser235 among obese patients with recent history of CRA. A phase IIa clinical biomarker trial was conducted via the U.S. National Cancer Institute-Chemoprevention Consortium. Nondiabetic, obese subjects (BMI ≥30) ages 35 to 80 with recent history of CRA were included. Subjects received 12 weeks of oral metformin 1,000 mg twice every day. Rectal mucosa biopsies were obtained at baseline and end-of-treatment (EOT) endoscopy. Tissue S6^Ser235 and Ki-67 immunostaining were analyzed in a blinded fashion using Histo score (Hscore) analysis. Among 32 eligible subjects, the mean baseline BMI was 34.9. Comparing EOT to baseline tissue S6^Ser235 by IHC, no significant differences were observed. Mean (SD) Hscore at baseline was 1.1 (0.57) and 1.1 (0.51) at EOT; median Hscore change was 0.034 (P = 0.77). Similarly, Ki-67 levels were unaffected by the intervention. The adverse events were consistent with metformin's known side-effect profile. Among obese patients with CRA, 12 weeks of oral metformin does not reduce rectal mucosa pS6 or Ki-67 levels. Further research is needed to determine what effects metformin has on the target tissue of origin as metformin continues to be pursued as a colorectal cancer chemopreventive agent.

AACR White Paper: Shaping the Future of Cancer Prevention - A Roadmap for Advancing Science and Public Health

The recent pace, extent, and impact of paradigm-changing cancer prevention science has been remarkable. The American Association for Cancer Research (AACR) convened a 3-day summit, aligned with five research priorities: (i) Precancer Atlas (PCA). (ii) Cancer interception. (iii) Obesity-cancer linkage, a global epidemic of chronic low-grade inflammation. (iv) Implementation science. (v) Cancer disparities. Aligned with these priorities, AACR co-led the Lancet Commission to formally endorse and accelerate the NCI Cancer Moonshot program, facilitating new global collaborative efforts in cancer control. The expanding scope of creative impact is perhaps most startling-from NCI-funded built environments to AACR Team Science Awarded studies of Asian cancer genomes informing global primary prevention policies; cell-free epigenetic marks identifying incipient neoplastic site; practice-changing genomic subclasses in myeloproliferative neoplasia (including germline variant tightly linked to JAK2 V617F haplotype); universal germline genetic testing for pancreatic cancer; and repurposing drugs targeting immune- and stem-cell signals (e.g., IL-1β, PD-1, RANK-L) to cancer interception. Microbiota-driven IL-17 can induce stemness and transformation in pancreatic precursors (identifying another repurposing opportunity). Notable progress also includes hosting an obesity special conference (connecting epidemiologic and molecular perspectives to inform cancer research and prevention strategies), co-leading concerted national implementation efforts in HPV vaccination, and charting the future elimination of cancer disparities by integrating new science tools, discoveries and perspectives into community-engaged research, including targeted counter attacks on e-cigarette ad exploitation of children, Hispanics and Blacks. Following this summit, two unprecedented funding initiatives were catalyzed to drive cancer prevention research: the NCI Cancer Moonshot (e.g., PCA and disparities); and the AACR-Stand Up To Cancer bold "Cancer Interception" initiative.

Cytotoxic Effects of Chlorophyllides in Ethanol Crude Extracts from Plant Leaves

Chlorophyllide (chlide) is a natural catabolic product of chlorophyll (Chl), produced through the activity of chlorophyllase (chlase). The growth inhibitory and antioxidant effects of chlide from different plant leaf extracts have not been reported. The aim of this study is to demonstrate that chlide in crude extracts from leaves has the potential to exert cytotoxic effects on cancer cell lines. The potential inhibitory and antioxidant effects of chlide in crude extracts from 10 plant leaves on breast cancer cells (MCF7 and MDA-MB-231), hepatocellular carcinoma cells (Hep G2), colorectal adenocarcinoma cells (Caco2), and glioblastoma cells (U-118 MG) were studied using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) and DPPH (1,1-diphenyl-2-picrylhydrazyl) assays. The results of the MTT assay showed that chlide in crude extracts from sweet potato were the most effective against all cancer cell lines tested. U-118 MG cells were the most sensitive, while Caco2 cells were the most resistant to the tested crude extracts. The cytotoxic effects of chlide and Chl in crude extracts from sweet potato and of commercial chlorophyllin (Cu-chlin), in descending order, were as follows: chlide > Chl > Cu-chlin. Notably, the IC₅₀ of sweet potato in U-118 MG cells was 45.65 μg/mL while those of Chl and Cu-chlin exceeded 200 μg/mL. In the DPPH assay, low concentrations (100 μg/mL) of chlide and Cu-chlin from crude extracts of sweet potato presented very similar radical scavenging activity to vitamin B2. The concentration of chlide was negatively correlated with DPPH activity. The current study was the first to demonstrate that chlide in crude extracts from leaves have potential cytotoxicity in cancer cell lines. Synergism between chlide and other compounds from leaf crude extracts may contribute to its cytotoxicity.

Targeting the Complement Pathway as a Therapeutic Strategy in Lung Cancer

Lung cancer is the leading cause of cancer death in men and women. Lung adenocarcinoma (LUAD), represents approximately 40% of all lung cancer cases. Advances in recent years, such as the identification of oncogenes and the use of immunotherapies, have changed the treatment of LUAD. Yet survival rates still remain low. Additionally, there is still a gap in understanding the molecular and cellular interactions between cancer cells and the immune tumor microenvironment (TME). Defining how cancer cells with distinct oncogenic drivers interact with the TME and new strategies for enhancing anti-tumor immunity are greatly needed. The complement cascade, a central part of the innate immune system, plays an important role in regulation of adaptive immunity. Initially it was proposed that complement activation on the surface of cancer cells would inhibit cancer progression via membrane attack complex (MAC)-dependent killing. However, data from several groups have shown that complement activation promotes cancer progression, probably through the actions of anaphylatoxins (C3a and C5a) on the TME and engagement of immunoevasive pathways. While originally shown to be produced in the liver, recent studies show localized complement production in numerous cell types including immune cells and tumor cells. These results suggest that complement inhibitory drugs may represent a powerful new approach for treatment of NSCLC, and numerous new anti-complement drugs are in clinical development. However, the mechanisms by which complement is activated and affects tumor progression are not well understood. Furthermore, the role of local complement production vs. systemic activation has not been carefully examined. This review will focus on our current understanding of complement action in LUAD, and describe gaps in our knowledge critical for advancing complement therapy into the clinic.

A History of Innovations in the Diagnosis and Treatment of Oral and Head and Neck Cancer

Historical records as far back as 3000 BCE show that oral and head and neck cancer was a disease process well known to Egyptian physicians. Luminaries such as Hippocrates, Galen, Pott, and Virchow were instrumental in shaping our understanding of the etiology and pathogenesis of cancer. During the 20th century, evidence-based medicine catalyzed the development of rigorous science-based diagnostic and treatment protocols. The use of surgery, therapeutic radiation, and chemotherapy as single-treatment agents or in combination with one another gradually emerged as the preferred approach to cancer therapy. The recognition of tobacco, alcohol, and human papillomavirus as etiological agents in oral and head and neck cancer prompted the development of new diagnostic aids and treatment strategies to mitigate cancer progression. More in-depth mechanistic insights into the multistep process of oral and head and neck cancer were made possible by the use of the hamster buccal pouch and mouse models. New technologies, such as the sequencing of the human genome, metabolomics, and proteomics, have provided the foundation for what we today call precision medicine. The future success of tailored medical treatment for cancer patients will depend on the discovery of new druggable targets with improved therapeutic efficacy. As the precision and sensitivity of existing tools for prevention and risk assessment improve, greater accuracy will be achieved in predicting health outcomes.

Acceptability of Localized Cancer Risk Reduction Interventions Among Individuals at Average or High Risk for Cancer

Individuals at high risk for cancer, including those already diagnosed with premalignant lesions, can potentially benefit from chemopreventive interventions to reduce cancer risk. However, uptake and acceptability have been hindered due to the risk of systemic toxicity and other adverse effects. Locally delivered chemopreventive agents, where direct action on the primary organ may limit systemic toxicity, are emerging as an option for high-risk individuals. While a number of clinical trials support the development of chemopreventive agents, it is crucial to understand the factors and barriers that influence their acceptability and use. We conducted 36 focus groups with 198 individuals at average and high risk of breast/ovarian, gynecologic, and head/neck/oral and lung cancers to examine the perceptions and acceptability of chemopreventive agents. Participants' willingness to use chemopreventive agents was influenced by several factors, including perceived risk of cancer, skepticism around prevention, previous knowledge of chemopreventive agents, support from trusted sources of health information, participation in other cancer-related risk-reduction activities, previous experience with similar modalities, cost, regimen, side effects, and perceived effectiveness of the preventive intervention. Our findings indicate that individuals may be more receptive to locally delivered chemopreventive agents if they perceive themselves to be at high risk for cancer and are given the necessary information regarding regimen and side effects to make an informed decision. Clinical trials that collect additional patient-centered data including side effects and how these interventions fit into an individual's lifestyle are imperative to improve uptake of chemopreventive agents.

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.

Fluorescent Ca2+ indicators directly inhibit the Na,K-ATPase and disrupt cellular functions

Fluorescent Ca²⁺ indicators have been essential for the analysis of Ca²⁺ signaling events in various cell types. We showed that chemical Ca²⁺ indicators, but not a genetically encoded Ca²⁺ indicator, potently suppressed the activity of Na⁺- and K⁺-dependent adenosine triphosphatase (Na,K-ATPase), independently of their Ca²⁺ chelating activity. Loading of commonly used Ca²⁺ indicators, including Fluo-4 acetoxymethyl (AM), Rhod-2 AM, and Fura-2 AM, and of the Ca²⁺ chelator BAPTA AM into cultured mouse or human neurons, astrocytes, cardiomyocytes, or kidney proximal tubule epithelial cells suppressed Na,K-ATPase activity by 30 to 80%. Ca²⁺ indicators also suppressed the agonist-induced activation of the Na,K-ATPase, altered metabolic status, and caused a dose-dependent loss of cell viability. Loading of Ca²⁺ indicators into mice, which is carried out for two-photon imaging, markedly altered brain extracellular concentrations of K⁺ and ATP. These results suggest that a critical review of data obtained with chemical Ca²⁺ indicators may be necessary.

Frizzled-7 is required for Xenopus heart development

Wnt signalling regulates cardiogenesis during specification of heart tissue and the morphogenetic movements necessary to form the linear heart. Wnt11-mediated non-canonical signalling promotes early cardiac development whilst Wnt11-R, which is expressed later, also signals through the non-canonical pathway to promote heart development. It is unclear which Frizzled proteins mediate these interactions. Frizzled-7 (fzd7) is expressed during gastrulation in the mesodermal cells fated to become heart, and then in the primary heart field. This expression is complementary to the expression of wnt11 and wnt11-R. We further show co-localisation of fzd7 with other early- and late-heart-specific markers using double in situ hybridisation. We have used loss of function analysis to determine the role of fzd7 during heart development. Morpholino antisense oligonucleotide-mediated knockdown of Fzd7 results in effects on heart development, similar to that caused by Wnt11 loss of function. Surprisingly, overexpression of dominant-negative Fzd7 cysteine rich domain (Fzd7 CRD) results in a cardia bifida phenotype, similar to the loss of wnt11-R phenotype. Overexpression of Fzd7 and activation of non-canonical wnt signalling can rescue the effect of Fzd7 CRD. We propose that Fzd7 has an important role during Xenopus heart development.

Summary: Wnt signalling has been shown to be important in heart development. Here, we demonstrate that the wnt receptor fzd7 is required in mediating these Wnt signals.

Evaluation of the Effects of Airborne Particulate Matter on Bone Marrow-Mesenchymal Stem Cells (BM-MSCs): Cellular, Molecular and Systems Biological Approaches

Particulate matter (PM) contains heavy metals that affect various cellular functions and gene expression associated with a range of acute and chronic diseases in humans. However, the specific effects they exert on the stem cells remain unclear. Here, we report the effects of PM collected from the city of Jeddah on proliferation, cell death, related gene expression and systems of biological analysis in bone marrow mesenchymal stem cells (BM-MSCs), with the aim of understanding the underlying mechanisms. PM_2.5 and PM₁₀ were tested in vitro at various concentrations (15 to 300 µg/mL) and durations (24 to 72 h). PMs induced cellular stress including membrane damage, shrinkage and death. Lower concentrations of PM_2.5 increased proliferation of BM-MSCs, while higher concentrations served to decrease it. PM₁₀ decreased BM-MSCs proliferation in a concentration-dependent manner. The X-ray fluorescence spectrometric analysis showed that PM contains high levels of heavy metals. Ingenuity Pathway Analysis (IPA) and hierarchical clustering analyses demonstrated that heavy metals were associated with signaling pathways involving cell stress/death, cancer and chronic diseases. qRT-PCR results showed differential expression of the apoptosis genes (BCL2, BAX); inflammation associated genes (TNF-α and IL-6) and the cell cycle regulation gene (p53). We conclude that PM causes inflammation and cell death, and thereby predisposes to chronic debilitating diseases.

Chemoprevention in African American Men With Prostate Cancer

BACKGROUND

Recommendations for cancer screening are uncertain for the early detection or prevention of prostate cancer in African American men. Thus, chemoprevention strategies are needed to specifically target African American men.

METHODS

The evidence was examined on the biological etiology of disparities in African Americans related to prostate cancer. Possible chemopreventive agents and biomarkers critical to prostate cancer in African American men were also studied.

RESULTS

High-grade prostatic intraepithelial neoplasia may be more prevalent in African American men, even after controlling for age, prostate-specific antigen (PSA) level, abnormal results on digital rectal examination, and prostate volume. Prostate cancer in African American men can lead to the overexpression of signaling receptors that may mediate increased proliferation, angiogenesis, and decreased apoptosis. Use of chemopreventive agents may be useful for select populations of men.

CONCLUSIONS

Green tea catechins are able to target multiple pathways to address the underlying biology of prostate carcinogenesis in African American men, so they may be ideal as a chemoprevention agent in these men diagnosed with high-grade prostatic intraepithelial neoplasia.

Predicting and Overcoming Chemotherapeutic Resistance in Breast Cancer

Our understanding of breast cancer and its therapeutic approach has improved greatly due to the advancement of molecular biology in recent years. Clinically, breast cancers are characterized into three basic types based on their immunohistochemical properties. They are triple-negative breast cancer, estrogen receptor (ER) and progesterone receptor (PR)-positive-HR positive breast cancer, and human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Even though these subtypes have been characterized, assessment of a breast cancer's receptor status is still widely used to determine whether or not a targeted therapy could be applied. Moreover, drug resistance is common in all breast cancer types despite the different treatment modalities applied. The development of resistance to different therapeutics is not mutually exclusive. It seems that tumor could be resistant to multiple treatment strategies, such as being both chemoresistant and monoclonal antibody resistant. However, the underlying mechanisms are complicated and need further investigation. In this chapter, we aim to provide a brief review of the different types of breast cancer and their respective treatment strategies. We also review the possible mechanisms of potential drug resistance associated with each treatment type. We believe that a better understanding of the drug resistance mechanisms can lead to a more effective and efficient therapeutic success.

Prognostic factors, predictive markers and cancer biology: the triad for successful oral cancer chemoprevention

Oral squamous cell carcinomas represent a significant cancer burden worldwide. Unfortunately, chemoprevention strategies investigated to date have failed to produce an agent considered standard of care to prevent oral cancers. Nonetheless, recent advances in clinical trial design may streamline drug development in this setting. In this manuscript, we review some of these improvements, including risk prediction tools based on molecular markers that help select patients most suitable for chemoprevention. We also discuss the opportunities that novel preclinical models and modern molecular profiling techniques will bring to the prevention field in the near future, and propose a clinical trials framework that incorporates molecular prognostic factors, predictive markers and cancer biology as a roadmap to improve chemoprevention strategies for oral cancers.

A Randomized Double-Blind Placebo-Controlled Phase IIB Trial of Curcumin in Oral Leukoplakia

Oral leukoplakia is a potentially malignant lesion of the oral cavity, for which no effective treatment is available. We investigated the effectiveness of curcumin, a potent inhibitor of NF-κB/COX-2, molecules perturbed in oral carcinogenesis, to treat leukoplakia. Subjects with oral leukoplakia (n = 223) were randomized (1:1 ratio) to receive orally, either 3.6 g/day of curcumin (n = 111) or placebo (n = 112), for 6 months. The primary endpoint was clinical response obtained by bi-dimensional measurement of leukoplakia size at recruitment and 6 months. Histologic response, combined clinical and histologic response, durability and effect of long-term therapy for an additional six months in partial responders, safety and compliance were the secondary endpoints. Clinical response was observed in 75 (67.5%) subjects [95% confidence interval (CI), 58.4-75.6] in the curcumin and 62 (55.3%; 95% CI, 46.1-64.2) in placebo arm (P = 0.03). This response was durable, with 16 of the 18 (88.9%; 95% CI, 67.2-96.9) subjects with complete response in curcumin and 7 of 8 subjects (87.5%) in placebo arm, demonstrating no relapse after 6 months follow-up. Difference in histologic response between curcumin and placebo was not significant (HR, 0.88, 95% CI, 0.45-1.71; P = 0.71). Combined clinical and histologic response assessment indicated a significantly better response with curcumin (HR, 0.50; 95% CI, 0.27-0.92; P = 0.02). Continued therapy, in subjects with partial response at 6 months, did not yield additional benefit. The treatment did not raise any safety concerns. Treatment of oral leukoplakia with curcumin (3.6 g for six months), thus was well tolerated and demonstrated significant and durable clinical response for 6 months. Cancer Prev Res; 9(8); 683-91. ©2016 AACR.

Cancer Prevention: Obstacles, Challenges and the Road Ahead

Approaches to reduce the global burden of cancer include two major strategies: screening and early detection and active preventive intervention. The latter is the topic of this Commentary and spans a broad range of activities. The genetic heterogeneity and complexity of advanced cancers strongly support the rationale for early interruption of the carcinogenic process and an enhanced focus on prevention as a priority strategy to reduce the burden of cancer; however, the focus of cancer prevention management should be on individuals at high risk and on primary localized disease in which screening and detection should also play a vital role. The timing and dose of (chemo-)preventive intervention also affects response. The intervention may be ineffective if the target population is very high risk or already presenting with preneoplastic lesions with cellular changes that cannot be reversed. The field needs to move beyond general concepts of carcinogenesis to targeted organ site prevention approaches in patients at high risk, as is currently being done for breast and colorectal cancers. Establishing the benefit of new cancer preventive interventions will take years and possibly decades, depending on the outcome being evaluated. We also propose that comparative effectiveness research designs and the value of information obtained from large-scale prevention studies are necessary in order for preventive interventions to become a routine part of cancer management.

European Code against Cancer 4th Edition: Medical exposures, including hormone therapy, and cancer

The 4th edition of the European Code against Cancer recommends limiting - or avoiding when possible - the use of hormone replacement therapy (HRT) because of the increased risk of cancer, nevertheless acknowledging that prescription of HRT may be indicated under certain medical conditions. Current evidence shows that HRT, generally prescribed as menopausal hormone therapy, is associated with an increased risk of cancers of the breast, endometrium, and ovary, with the risk pattern depending on factors such as the type of therapy (oestrogen-only or combined oestrogen-progestogen), duration of treatment, and initiation according to the time of menopause. Carcinogenicity has also been established for anti-neoplastic agents used in cancer therapy, immunosuppressants, oestrogen-progestogen contraceptives, and tamoxifen. Medical use of ionising radiation, an established carcinogen, can provide major health benefits; however, prudent practices need to be in place, with procedures and techniques providing the needed diagnostic information or therapeutic gain with the lowest possible radiation exposure. For pharmaceutical drugs and medical radiation exposure with convincing evidence on their carcinogenicity, health benefits have to be balanced against the risks; potential increases in long-term cancer risk should be considered in the context of the often substantial and immediate health benefits from diagnosis and/or treatment. Thus, apart from HRT, no general recommendations on reducing cancer risk were given for carcinogenic drugs and medical radiation in the 4th edition of European Code against Cancer. It is crucial that the application of these measures relies on medical expertise and thorough benefit-risk evaluation. This also pertains to cancer-preventive drugs, and self-medication with aspirin or other potential chemopreventive drugs is strongly discouraged because of the possibility of serious, potentially lethal, adverse events.

Biomarkers in phase I-II chemoprevention trials: lessons from the NCI experience

Early phase clinical trials are an essential component of chemopreventive drug development to identify signals of drug efficacy that can subsequently be explored definitively in phase III trials. Whereas phase I trials focus on safety and identification of optimal dose and schedule for cancer prevention, phase II trials focus on intermediate endpoints that are variably related to cancer development. The United States National Cancer Institute supports a programme devoted to early phase cancer prevention clinical trials. The experience, along with the benefits and limitations of the range of biomarker endpoints used in these studies, are reviewed here.

Industry perspectives on biomarker qualification

Biomarkers have the potential to expedite drug development, increase patient safety, and optimize clinical response. Yet few have achieved regulatory qualification. A survey was conducted to clarify industry's perspective on biomarker qualification and identify the most promising biomarkers for drug development. The results across toxicities/clinical areas highlight challenges in regulatory qualification, although early prioritization and alignment on an evidentiary standard framework are key factors in facilitating biomarker development and qualification.

Molecular cancer prevention: Current status and future directions

The heterogeneity and complexity of advanced cancers strongly support the rationale for an enhanced focus on molecular prevention as a priority strategy to reduce the burden of cancer. Molecular prevention encompasses traditional chemopreventive agents as well as vaccinations and therapeutic approaches to cancer-predisposing conditions. Despite challenges to the field, we now have refined insights into cancer etiology and early pathogenesis; successful risk assessment and new risk models; agents with broad preventive efficacy (eg, aspirin) in common chronic diseases, including cancer; and a successful track record of more than 10 agents approved by the US Food and Drug Administration for the treatment of precancerous lesions or cancer risk reduction. The development of molecular preventive agents does not differ significantly from the development of therapies for advanced cancers, yet it has unique challenges and special considerations given that it most often involves healthy or asymptomatic individuals. Agents, biomarkers, cohorts, overall design, and endpoints are key determinants of molecular preventive trials, as with therapeutic trials, although distinctions exist for each within the preventive setting. Progress in the development and evolution of molecular preventive agents has been steadier in some organ systems, such as breast and skin, than in others. In order for molecular prevention to be fully realized as an effective strategy, several challenges to the field must be addressed. Here, the authors provide a brief overview of the context for and special considerations of molecular prevention along with a discussion of the results from major randomized controlled trials.

Assessment of Esophageal Adenocarcinoma Risk Using Somatic Chromosome Alterations in Longitudinal Samples in Barrett's Esophagus

Cancers detected at a late stage are often refractory to treatments and ultimately lethal. Early detection can significantly increase survival probability, but attempts to reduce mortality by early detection have frequently increased overdiagnosis of indolent conditions that do not progress over a lifetime. Study designs that incorporate biomarker trajectories in time and space are needed to distinguish patients who progress to an early cancer from those who follow an indolent course. Esophageal adenocarcinoma is characterized by evolution of punctuated and catastrophic somatic chromosomal alterations and high levels of overall mutations but few recurrently mutated genes aside from TP53. Endoscopic surveillance of Barrett's esophagus for early cancer detection provides an opportunity for assessment of alterations for cancer risk in patients who progress to esophageal adenocarcinoma compared with nonprogressors. We investigated 1,272 longitudinally collected esophageal biopsies in a 248 Barrett's patient case-cohort study with 20,425 person-months of follow-up, including 79 who progressed to early-stage esophageal adenocarcinoma. Cancer progression risk was assessed for total chromosomal alterations, diversity, and chromosomal region-specific alterations measured with single-nucleotide polymorphism arrays in biopsies obtained over esophageal space and time. A model using 29 chromosomal features was developed for cancer risk prediction (area under receiver operator curve, 0.94). The model prediction performance was robust in two independent esophageal adenocarcinoma sets and outperformed TP53 mutation, flow cytometric DNA content, and histopathologic diagnosis of dysplasia. This study offers a strategy to reduce overdiagnosis in Barrett's esophagus and improve early detection of esophageal adenocarcinoma and potentially other cancers characterized by punctuated and catastrophic chromosomal evolution.

The effect of statins on cancer cells--review

Statins [3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase, abbreviated HMGCR) inhibitors], are well-known cholesterol-depleting agents. Since the early 1990 s, it has been known that statins could be successfully used in cancer therapy, but the exact mechanism(s) of statin activity remains unclear and is now an extensive focus of investigation. So far, it was proven that there are several mechanisms that are activated by statins in cancer cells; some of them are leading to cell death. Statins exert different effects depending on cell line, statin concentration, duration of exposure of cells to statins, and the type of statin being used. It was shown that statins may inhibit the cell cycle by influence on both expression and activity of proteins involved in cell-cycle progression such as cyclins, cyclin-dependent kinases (CDK), and/or inhibitors of CDK. Also, statins may induce apoptosis by both intrinsic and extrinsic pathways. Statin treatment may lead to changes in molecular pathways dependent on the EGF receptor, mainly via inhibition of isoprenoid synthesis. By inhibition of the synthesis of cholesterol, statins may destabilize the cell membrane. Moreover, statins may change the arrangement of transporter OATP1, the localization of HMGCR, and could induce conformational changes in GLUT proteins. In this review, we have tried to gather and compare most of the recent outcomes of the research in this field. We have also attempted to explain why hydrophilic statins are less effective than hydrophobic statins. Finally, we have gathered results from in vivo experiments, presenting the use of statins in combined therapies and discussed a number of molecular targets that could serve as biomarkers predisposing to statin therapy.

Influence of ionic strength on the interaction of THA and its Cu(ii) complex with DNA helps to explain studies on various breast cancer cells

Purpurin, a structural analogue of anthracycline anticancer drugs, was used to understand how environmental changes affect its biophysical interactions with DNA and along with its Cu(ii) complex, the activity it shows on breast cancer cells.

Tumor suppressor genes promote rhabdomyosarcoma progression in p53 heterozygous, HER-2/neu transgenic mice

Human sarcomas arise suddenly, thus preempting the study of preneoplastic and early neoplastic lesions. To explore the natural history of these tumors we studied male mice carrying a heterozygous deletion of p53 and an activated HER-2/neu transgene (BALB-p53Neu mice), that develop urethral rhabdomyosarcomas with nearly full penetrance and early onset (4 months of age). Among genes prominently upregulated in preneoplastic tissue, and more highly expressed in tumors, we found the insulin-like growth factor 2 (Igf2) and tumor suppressors, p19Arf and p21Cip1. In urethral tissues of male mice p53 was less expressed than in female mice, whereas HER-2/neu was more expressed, a combination not found in other skeletal muscles of the same mice that could contribute to the anatomic and sexual specificity of BALB-p53Neu rhabdomyosarcoma. Upregulation of p19Arf and p21Cip1 was additively determined by HER-2/neu activation and by p53 inactivation. Silencing of p19Arf or p21Cip1 in rhabdomyosarcoma cell lines can inhibit cell growth and motility, thus suggesting that these genes can contribute to growth autonomy and malignancy of tumor cells. In vivo injection of gene-silenced cells highlighted selective variations in organ-specific metastatic ability, indicating that overexpression of p19Arf and p21Cip1 controlled both tumor cell-intrinsic properties and microenvironmental interactions. The onset of pelvic rhabdomyosarcoma in BALB-p53Neu male mice is triggered by the coincidental overexpression of HER-2/neu and hypoexpression of the residual p53 allele, that foster p53 loss, Igf2 autocriny and overexpression of p19Arf and p21Cip1, a phenotype that could provide novel potential targets for cancer prevention and therapy.

Expression of estrogen-induced genes and estrogen receptor β in pancreatic neuroendocrine tumors: implications for targeted therapy

OBJECTIVE

The indolent nature and expression of progesterone receptor (PR), a well-known estrogen-induced gene, in a subset of pancreatic neuroendocrine tumors (PanNETs), raise the possibility of hormonal regulation in these tumors.

METHODS

Immunohistochemical expression of estrogen receptors (ERs) α and β as well as messenger RNA expression of estrogen-induced genes (PR, EIG121, IGF-1, IGF-1R, sFRP1, and sFRP4) by quantitative reverse transcription-polymerase chain reaction were examined in 131 World Health Organization grade G1 and G2 PanNETs and correlated their expression with clinicopathological features.

RESULTS

Thirty-nine PanNETs (30%) showed high positive ERβ staining, and 87 cases (66%) had low positive ERβ staining; only 5 cases (4%) had no nuclear staining. Pancreatic neuroendocrine tumors with small size (P = 0.02), low World Health Organization grade (P = 0.02), and low American Joint Committee on Cancer stage (P = 0.006) more frequently showed high positive ERβ staining. Among the estrogen-induced genes studied, PanNETs had significantly higher expression of PR, EIG121, IGF-1, sFRP1, and sFRP4 compared with normal pancreas, independent of age or sex. High positive ERβ staining was associated with an increased expression of PR (P < 0.001) and EIG121 (P = 0.02).

CONCLUSIONS

Our study showed that PanNETs with favorable prognostic features have higher ERβ expression, which is associated with up-regulated PR and EIG121 messenger RNA expression. Estrogen regulation in PanNETs could potentially help in risk stratification and provide a rational target for novel treatment strategies.

Convergence of nanotechnology and cancer prevention: are we there yet?

Nanotechnology is emerging as a promising modality for cancer treatment; however, in the realm of cancer prevention, its full utility has yet to be determined. Here, we discuss the potential of integrating nanotechnology in cancer prevention to augment early diagnosis, precision targeting, and controlled release of chemopreventive agents, reduced toxicity, risk/response assessment, and personalized point-of-care monitoring. Cancer is a multistep, progressive disease; the functional and acquired characteristics of the early precancer phenotype are intrinsically different from those of a more advanced anaplastic or invasive malignancy. Therefore, applying nanotechnology to precancers is likely to be far more challenging than applying it to established disease. Frank cancers are more readily identifiable through imaging and biomarker and histopathologic assessment than their precancerous precursors. In addition, prevention subjects routinely have more rigorous intervention criteria than therapy subjects. Any nanopreventive agent developed to prevent sporadic cancers found in the general population must exhibit a very low risk of serious side effects. In contrast, a greater risk of side effects might be more acceptable in subjects at high risk for cancer. Using nanotechnology to prevent cancer is an aspirational goal, but clearly identifying the intermediate objectives and potential barriers is an essential first step in this exciting journey.

Cold atmospheric plasma treatment selectively targets head and neck squamous cell carcinoma cells

The treatment of locoregional recurrence (LRR) of head and neck squamous cell carcinoma (HNSCC) often requires a combination of surgery, radiation therapy and/or chemotherapy. Survival outcomes are poor and the treatment outcomes are morbid. Cold atmospheric plasma (CAP) is an ionized gas produced at room temperature under laboratory conditions. We have previously demonstrated that treatment with a CAP jet device selectively targets cancer cells using in vitro melanoma and in vivo bladder cancer models. In the present study, we wished to examine CAP selectivity in HNSCC in vitro models, and to explore its potential for use as a minimally invasive surgical approach that allows for specific cancer cell or tumor tissue ablation without affecting the surrounding healthy cells and tissues. Four HNSCC cell lines (JHU-022, JHU-028, JHU-029, SCC25) and 2 normal oral cavity epithelial cell lines (OKF6 and NOKsi) were subjected to cold plasma treatment for durations of 10, 30 and 45 sec, and a helium flow of 20 l/min-1 for 10 sec was used as a positive treatment control. We showed that cold plasma selectively diminished HNSCC cell viability in a dose-response manner, as evidenced by MTT assays; the viability of the OKF6 cells was not affected by the cold plasma. The results of colony formation assays also revealed a cell-specific response to cold plasma application. Western blot analysis did not provide evidence that the cleavage of PARP occurred following cold plasma treatment. In conclusion, our results suggest that cold plasma application selectively impairs HNSCC cell lines through non-apoptotic mechanisms, while having a minimal effect on normal oral cavity epithelial cell lines.

Mitigating the risk of radiation-induced cancers: limitations and paradigms in drug development

The United States radiation medical countermeasures (MCM) programme for radiological and nuclear incidents has been focusing on developing mitigators for the acute radiation syndrome (ARS) and delayed effects of acute radiation exposure (DEARE), and biodosimetry technologies to provide radiation dose assessments for guiding treatment. Because a nuclear accident or terrorist incident could potentially expose a large number of people to low to moderate doses of ionising radiation, and thus increase their excess lifetime cancer risk, there is an interest in developing mitigators for this purpose. This article discusses the current status, issues, and challenges regarding development of mitigators against radiation-induced cancers. The challenges of developing mitigators for ARS include: the long latency between exposure and cancer manifestation, limitations of animal models, potential side effects of the mitigator itself, potential need for long-term use, the complexity of human trials to demonstrate effectiveness, and statistical power constraints for measuring health risks (and reduction of health risks after mitigation) following relatively low radiation doses (<0.75 Gy). Nevertheless, progress in the understanding of the molecular mechanisms resulting in radiation injury, along with parallel progress in dose assessment technologies, make this an opportune, if not critical, time to invest in research strategies that result in the development of agents to lower the risk of radiation-induced cancers for populations that survive a significant radiation exposure incident.

Updates and controversies in the rapidly evolving field of lung cancer screening, early detection, and chemoprevention

Lung cancer remains the leading cause of cancer-related death in the United States. Cigarette smoking is a well-recognized risk factor for lung cancer, and a sustained elevation of lung cancer risk persists even after smoking cessation. Despite identifiable risk factors, there has been minimal improvement in mortality for patients with lung cancer primarily stemming from diagnosis at a late stage when there are few effective therapeutic options. Early detection of lung cancer and effective screening of high-risk individuals may help improve lung cancer mortality. While low dose computerized tomography (LDCT) screening of high risk smokers has been shown to reduce lung cancer mortality, the high rates of false positives and potential for over-diagnosis have raised questions on how to best implement lung cancer screening. The rapidly evolving field of lung cancer screening and early-detection biomarkers may ultimately improve the ability to diagnose lung cancer in its early stages, identify smokers at highest-risk for this disease, and target chemoprevention strategies. This review aims to provide an overview of the opportunities and challenges related to lung cancer screening, the field of biomarker development for early lung cancer detection, and the future of lung cancer chemoprevention.

Mechanisms associated with resistance to tamoxifen in estrogen receptor-positive breast cancer (review)

Anti-estrogens such as tamoxifen are widely used in the clinic to treat estrogen receptor-positive breast tumors. Patients with estrogen receptor-positive breast cancer initially respond to treatment with anti-hormonal agents such as tamoxifen, but remissions are often followed by the acquisition of resistance and, ultimately, disease relapse. The development of a rationale for the effective treatment of tamoxifen-resistant breast cancer requires an understanding of the complex signal transduction mechanisms. In the present study, we explored some mechanisms associated with resistance to tamoxifen, such as pharmacologic mechanisms, loss or modification in estrogen receptor expression, alterations in co-regulatory proteins and the regulation of the different signaling pathways that participate in different cellular processes such as survival, proliferation, stress, cell cycle, inhibition of apoptosis regulated by the Bcl-2 family, autophagy, altered expression of microRNA, and signaling pathways that regulate the epithelial-mesenchymal transition in the tumor microenvironment. Delineation of the molecular mechanisms underlying the development of resistance may aid in the development of treatment strategies to enhance response and compromise resistance.

Key tumor suppressor genes inactivated by "greater promoter" methylation and somatic mutations in head and neck cancer

Tumor suppressor genes (TSGs) are commonly inactivated by somatic mutation and/or promoter methylation; yet, recent high-throughput genomic studies have not identified key TSGs inactivated by both mechanisms. We pursued an integrated molecular analysis based on methylation binding domain sequencing (MBD-seq), 450K Methylation arrays, whole exome sequencing, and whole genome gene expression arrays in primary head and neck squamous cell carcinoma (HNSCC) tumors and matched uvulopalatopharyngoplasty tissue samples (UPPPs). We uncovered 186 downregulated genes harboring cancer specific promoter methylation including PAX1 and PAX5 and we identified 10 key tumor suppressor genes (GABRB3, HOXC12, PARP15, SLCO4C1, CDKN2A, PAX1, PIK3AP1, HOXC6, PLCB1, and ZIC4) inactivated by both promoter methylation and/or somatic mutation. Among the novel tumor suppressor genes discovered with dual mechanisms of inactivation, we found a high frequency of genomic and epigenomic alterations in the PAX gene family of transcription factors, which selectively impact canonical NOTCH and TP53 pathways to determine cell fate, cell survival, and genome maintenance. Our results highlight the importance of assessing TSGs at the genomic and epigenomic level to identify key pathways in HNSCC, deregulated by simultaneous promoter methylation and somatic mutations.

Anticancer activities of sulindac in prostate cancer cells associated with c-Jun NH2-terminal kinase 1/β-catenin signaling

The non-steroidal anti-inflammatory agent, sulindac, has shown strong effects on cancer prevention in colorectal cancers, however, its anticancer activities on prostate cancer remain unclear. In the current study, human prostate cancer cell lines, LNCaP and PC-3, were treated with various concentrations of sulindac and it was found that sulindac significantly inhibits prostate cancer cell proliferation and promotes cell apoptosis in a dose- and time-dependent manner. Further studies revealed that sulindac significantly induces c-Jun NH2-terminal kinase (JNK) 1 phosphorylation and inhibits β-catenin at the transcriptional and post-transcriptional levels. In conclusion, by targeting the JNK1/β-catenin signaling pathway, sulindac may present a potential preventive or therapeutic agent for treatment of patients with prostate cancer.

Safety and chemopreventive effect of Polyphenon E in preventing early and metastatic progression of prostate cancer in TRAMP mice

Prostate cancer treatment is often accompanied by untoward side effects. Therefore, chemoprevention to reduce the risk and inhibit the progression of prostate cancer may be an effective approach to reducing disease burden. We investigated the safety and efficacy of Polyphenon E, a green tea extract, in reducing the progression of prostate cancer in transgenic adenocarcinoma of the mouse prostate (TRAMP) mice. A total of 119 male TRAMP and 119 C57BL/6J mice were treated orally with one of 3 doses of Polyphenon E (200, 500, and 1,000 mg/kg/day) in drinking water ad libitum replicating human achievable doses. Baseline assessments were performed before treatments. Safety and efficacy assessments during treatments were performed when mice were 12, 22, and 32 weeks old. The number and size of tumors in treated TRAMP mice were significantly decreased compared with untreated animals. In untreated 32 weeks old TRAMP mice, prostate carcinoma metastasis to distant sites was observed in 100% of mice (8/8), compared with 13% of mice (2/16) treated with high-dose Polyphenon E during the same period. Furthermore, Polyphenon E treatment significantly inhibited metastasis in TRAMP mice in a dose-dependent manner (P = 0.0003). Long-term (32 weeks) treatment with Polyphenon E was safe and well tolerated with no evidence of toxicity in C57BL/6J mice. Polyphenon E is an effective chemopreventive agent in preventing the progression of prostate cancer to metastasis in TRAMP mice. Polyphenon E showed no toxicity in these mouse models. Our findings provide additional evidence for the safety and chemopreventive effect of Polyphenon E in preventing metastatic progression of prostate cancer.

Glycoproteomics using fluid-based specimens in the discovery of lung cancer protein biomarkers: promise and challenge

Lung cancer is the leading cancer in the United States and worldwide. In spite of the rapid progression in personalized treatments, the overall survival rate of lung cancer patients is still suboptimal. Over the past decade, tremendous efforts have been focused on the discovery of protein biomarkers to facilitate the early detection and monitoring of lung cancer progression during treatment. In addition to tumor tissues and cancer cell lines, a variety of biological material has been studied. Particularly in recent years, studies using fluid-based specimen or so-called "fluid-biopsy" specimens have progressed rapidly. Fluid specimens are relatively easier to collect than tumor tissue, and they can be repeatedly sampled during the disease progression. Glycoproteins are the major content of fluid specimens and have long been recognized to play fundamental roles in many physiological and pathological processes. In this review, we focus the discussion on recent advances of glycoproteomics, particularly in the identification of potential glyco protein biomarkers using fluid-based specimens in lung cancer. The purpose of this review is to summarize current strategies, achievements, and perspectives in the field. This insight will highlight the discovery of tumor-associated glycoprotein biomarkers in lung cancer and their potential clinical applications.

Combined modality treatment of laryngeal squamous cell carcinoma

Squamous cell carcinoma of the larynx is a major public health concern; it causes substantial morbidity and mortality, and arises chiefly as a result of tobacco and alcohol consumption. Early stage disease is best treated with radiation or surgery alone, but for patients with more locally advanced squamous cell carcinoma of the larynx, combined modality treatment has been shown to benefit selected patients, particularly when cisplatin-based chemotherapy and concurrent radiation therapy are employed, with or without altered fractionated radiation therapy. Substantial laryngectomy-associated quality-of-life decrements can be avoided in selected, potentially resectable patients with organ-sparing approaches, without sacrificing survival. Recently, trials have addressed the role of targeted systemic agents to the epidermal growth factor receptor, and other targets are under investigation. The addition of induction chemotherapy to concurrent chemoradiotherapy is a promising treatment strategy that warrants further evaluation, but has not yet emerged as a standard of care; the toxicity of such regimens must be balanced with the potential benefits on a case-by-case basis, and functional outcomes are often quite variable. Treatment planning, management and follow-up are complex, and thus should ideally be performed in a comprehensive, multidisciplinary fashion, in a center accustomed to a high volume of such cases. Future research directions are described herein.

Targeting the epidermal growth factor receptor for head and neck cancer chemoprevention

The epidermal growth factor receptor (EGFR) has been implicated in head and neck squamous cell carcinoma (HNSCC) carcinogenesis. It is currently the only molecular target in head and neck cancers for which there are pharmacologic therapeutic interventions approved by regulatory agencies worldwide to treat advanced disease. Oral pre-malignant lesions have increased EGFR protein expression and increased egfr gene copy number compared to normal mucosa. Oral pre-malignant lesions with overexpression of EGFR or egfr gene copy number gain are at higher risk for malignant transformation. Inhibition of EGFR in pre-clinical models of oral pre-malignancies validates this approach as an effective way to reduce the incidence of oral cancer, and supports investigation of this strategy in the clinic. Clinical trials with EGFR targeted agents, including cetuximab, erlotinib, and vandetanib, are currently under way, some with promising preliminary results. If ultimately shown to reduce the risk of oral cancer, chemoprevention with EGFR inhibitors may significantly reduce morbidity and possibly mortality from HNSCC.

TIMP3 and CCNA1 hypermethylation in HNSCC is associated with an increased incidence of second primary tumors

BACKGROUND

Hypermethylation in the promoter regions is associated with the suppression of gene expression and has been considered a potential molecular marker for several tumor types, including head and neck squamous cell carcinomas (HNSCC).

METHODS

To evaluate the gene hypermethylation profile as a prognostic marker, this retrospective study used a QMSP approach to determine the methylation status of 19 genes in 70 HNSCC patients.

RESULTS

The methylation profile analysis of primary HNSCC revealed that genes CCNA1, DAPK, MGMT, TIMP3 and SFRP1 were frequently hypermethylated, with high specificity and sensitivity. TIMP3 and CCNA1 hypermethylation was significantly associated with lower rates of second primary tumor-free survival (p = 0.007 and p = 0.001; log-rank test, respectively).

CONCLUSION

This study, for the first time, presents CCNA1 and TIMP3 hypermethylation as a helpful tool to identify HNSCC subjects at risk of developing second primary carcinomas.

Optimizing biomarkers and endpoints in oral cancer chemoprevention trials

Chemoprevention, defined as the use of natural, synthetic, or biologic compounds to halt, reverse, or prevent the initial phases of carcinogenesis or the progression of neoplastic cells to cancer, has produced successes, but progress has been slow. Notably, in the field of oral cancer prevention and despite extensive clinical investigations, a standard systemic therapy for patients with oral premalignant lesions is yet to be developed. In view of safety concerns surrounding the use of pharmaceuticals, the use of phytochemicals derived from the diet has been considered but has not yet translated into clinical success. The Bowman Birk Inhibitor (BBI) is a serine protease inhibitor isolated from soybeans possessing domains with trypsin and chymotrypsin inhibitory activity. Encouraging results were previously reported in a phase IIa trial of BBI complex in patients with oral leukoplakia with measurable clinical responses and favorable biomarker changes. In this issue of the journal, the less promising results of the randomized, placebo-controlled phase IIb trial are presented. In this commentary, the complexities involved in defining optimal biomarkers and endpoints for oral cancer prevention trials and the development of dietary chemoprevention agents are discussed.

Resveratrol in the management of human cancer: how strong is the clinical evidence?

Among the plethora of biochemical mechanisms engaged by resveratrol in preclinical systems, its anticarcinogenic effects represent some of the most convincing and intriguing. As outlined in this review, there is considerable interest in developing resveratrol for cancer prevention and treatment. The plasma pharmacokinetics of resveratrol in humans are now reasonably well defined, and studies have shown that repeated daily doses up to 1 g are safe and well tolerated, although gastrointestinal toxicity is observed at higher intakes. However, care is needed regarding underlying conditions in specific patient groups, and there is potential for drug interactions at doses greater than 1 gram. Little is known regarding the pharmacodynamic effects of resveratrol in humans, but the observation that it modulates components of the insulin-like growth factor system in the plasma of volunteers is encouraging. While the knowledge base that helps determine whether resveratrol may be useful in cancer management has increased substantially in recent years, important questions remain.

DNA methylation in tumour and normal mucosal tissue of head and neck squamous cell carcinoma (HNSCC) patients: new diagnostic approaches and treatment

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide. Long-term survival of this patient group has been marginally improved during the last 30 years. This is due to the high recurrence rate of local primary or development of second primary tumours in the patients. We found that normal-appearing surgical margins and distant mucosal tissue of HNSCC patients contained tumour suppressor genes DNA methylation. These cells might be the progenitors of the tumour recurrences. Such molecular abnormalities in the normal-appearing mucosa tissue were not possible to detect in the clinic or by standard histopathologically analysis. To improve clinical outcome, the convenient and cost-effective molecular analysis such as methylation-specific PCR should be added to the pathological diagnosis armamentarium for HNSCC patients. The beneficial effect of antimethylating agents as additional treatment or for cancer chemoprevention, in this high-risk patient group, warrants further investigation.