Combinatorial chemoprevention of intestinal neoplasia

Evaluation of EGFR and COX pathway inhibition in human colon organoids of serrated polyposis and other hereditary cancer syndromes

Serrated polyposis syndrome (SPS) presents with multiple sessile serrated lesions (SSL) in the large intestine and confers increased colorectal cancer (CRC) risk. However, the etiology of SPS is not known. SSL-derived organoids have not been previously studied but may help provide insights into SPS pathogenesis and identify novel biomarkers and chemopreventive strategies. This study examined effects of EGFR and COX pathway inhibition in organoid cultures derived from uninvolved colon and polyps of SPS patients. We also compared with organoids representing the hereditary gastrointestinal syndromes, Familial Adenomatous Polyposis (FAP) and Lynch syndrome (LS). Eighteen total organoid colon cultures were generated from uninvolved colon and polyps in SPS, FAP, LS, and non-syndromic screening colonoscopy patients. BRAF and KRAS mutation status was determined for each culture. Erlotinib (EGFR inhibitor) and sulindac (COX inhibitor) were applied individually and in combination. A 44-target gene custom mRNA panel (including WNT and COX pathway genes) and a 798-gene microRNA gene panel were used to quantitate organoid RNA expression by NanoString analysis. Erlotinib treatment significantly decreased levels of mRNAs associated with WNT and MAPK kinase signaling in organoids from uninvolved colon from all four patient categories and from all SSL and adenomatous polyps. Sulindac did not change the mRNA profile in any culture. Our findings suggest that EGFR inhibitors may contribute to the chemopreventive treatment of SSLs. These findings may also facilitate clinical trial design using these agents in SPS patients. Differentially expressed genes identified in our study (MYC, FOSL1, EGR1, IL33, LGR5 and FOXQ1) may be used to identify other new molecular targets for chemoprevention of SSLs.

A Contemporary Review on the Critical Role of Nonsteroidal Anti-inflammatory Agents in Colorectal Cancer Therapy

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) are widely recognized as effective pain relievers and function by inhibiting the cyclooxygenase enzyme (COXs). Moreover, they have been found to participate in various cellular processes through different signaling pathways, such as WNT, MAPK, NF-κB, and PI3K/AKT/mTOR. This makes them potential candidates for chemoprevention of several malignancies, particularly colorectal cancer (CRC). However, the use of NSAIDs in cancer prevention and treatment is a complex issue due to their adverse effects and gastrointestinal toxicity. Therefore, it is crucial to explore combination therapies that can minimize side effects while maximizing synergistic effects with other agents and to evaluate the success rate of such approaches in both pre-clinical and clinical studies. In this review, we aim to provide an overview of the effects of NSAIDs in the prevention and treatment of CRC. We will focus on elucidating the possible mechanisms of action of these drugs, the signaling pathways involved in CRC, and the potential synergistic effects when combined with other therapeutic agents.

Phase II trial of weekly erlotinib dosing to reduce duodenal polyp burden associated with familial adenomatous polyposis

IMPORTANCE

Patients with familial adenomatous polyposis (FAP) are at markedly increased risk for duodenal adenomas and cancer. Combination sulindac and erlotinib was previously shown to reduce duodenal polyp burden but was associated with a relatively high adverse event (AE) rate.

OBJECTIVE

To evaluate if a once weekly dosing schedule for erlotinib intervention improves the AE profile, while still providing efficacy with respect to reduced polyp burden, in participants with FAP.

DESIGN, SETTING AND PARTICIPANTS

Single-arm trial, enrolling 46 participants with FAP, conducted from October 2017 to September 2019 in eight academic cancer centres.

EXPOSURES

Participants self-administered 350 mg of erlotinib by mouth, one time per week for 6 months.

MAIN OUTCOMES AND MEASURES

Duodenal polyp burden (sum of polyp diameters) was assessed in the proximal duodenum by esophagogastroduodenoscopy performed at baseline and 6 months, with mean per cent change defined as the primary efficacy outcome of interest. Rate of grade 2-3 AEs was evaluated as a co-primary outcome. Secondary outcomes included changes in total duodenal polyp count, along with changes in lower gastrointestinal (GI) polyp burden and count (for participants examined by optional lower endoscopy).

RESULTS

Forty-six participants (mean age, 44.1 years (range, 18-68); women, 22 (48%)) were enrolled; 42 participants completed 6 months of intervention and were included in the per-protocol analysis. Duodenal polyp burden was significantly reduced after 6 months of weekly erlotinib intervention, with a mean per cent change of -29.6% (95% CI, -39.6% to -19.7%; p<0.0001). Similar results were observed in subgroup analyses defined by participants with advanced duodenal polyposis (Spigelman 3) at baseline (mean, -27%; 95% CI, -38.7% to -15.2%; p<0.0001). Post-intervention Spigelman stage was downstaged in 12% of the participants. Lower GI polyp number was also decreased after 6 months of intervention (median, -30.8%; IQR, -47.4% to 0.0%; p=0.0256). Grade 2 or 3 AEs were reported in 71.7% of subjects, with only two experiencing grade 3 toxicity at least possibly related to intervention.

CONCLUSION

In this single-arm, multi-centre trial of participants with FAP, erlotinib one time per week resulted in markedly lower duodenal polyp burden, and modestly reduced lower GI polyp burden, after 6 months of intervention. While AEs were still reported by nearly three-quarters of all participants, these events were generally lower grade and well-tolerated. These findings support further investigation of erlotinib as an effective, acceptable cancer preventive agent for FAP-associated GI polyposis.

TRIAL REGISTRATION NUMBER

NCT02961374.

To Investigate Growth Factor Receptor Targets and Generate Cancer Targeting Inhibitors

Receptor tyrosine kinase (RTK) regulates multiple pathways, including Mitogenactivated protein kinases (MAPKs), PI3/AKT, JAK/STAT pathway, etc. which has a significant role in the progression and metastasis of tumor. As RTK activation regulates numerous essential bodily processes, including cell proliferation and division, RTK dysregulation has been identified in many types of cancers. Targeting RTK is a significant challenge in cancer due to the abnormal upregulation and downregulation of RTK receptors subfamily EGFR, FGFR, PDGFR, VEGFR, and HGFR in the progression of cancer, which is governed by multiple RTK receptor signalling pathways and impacts treatment response and disease progression. In this review, an extensive focus has been carried out on the normal and abnormal signalling pathways of EGFR, FGFR, PDGFR, VEGFR, and HGFR and their association with cancer initiation and progression. These are explored as potential therapeutic cancer targets and therefore, the inhibitors were evaluated alone and merged with additional therapies in clinical trials aimed at combating global cancer.

Prediction and evaluation of combination pharmacotherapy using natural language processing, machine learning and patient electronic health records

Combination pharmacotherapy targets key disease pathways in a synergistic or additive manner and has high potential in treating complex diseases. Computational methods have been developed to identifying combination pharmacotherapy by analyzing large amounts of biomedical data. Existing computational approaches are often underpowered due to their reliance on our limited understanding of disease mechanisms. On the other hand, observable phenotypic inter-relationships among thousands of diseases often reflect their underlying shared genetic and molecular underpinnings, therefore can offer unique opportunities to design computational models to discover novel combinational therapies by automatically transferring knowledge among phenotypically related diseases. We developed a novel phenome-driven drug discovery system, named TuSDC, which leverages knowledge of existing drug combinations, disease comorbidities, and disease treatments of thousands of disease and drug entities extracted from over 31.5 million biomedical research articles using natural language processing techniques. TuSDC predicts combination pharmacotherapy by extracting representations of diseases and drugs using tensor factorization approaches. In external validation, TuSDC achieved an average precision of 0.77 for top ranked candidates, outperforming a state of art mechanism-based method for discovering drug combinations in treating hypertension. We evaluated top ranked anti-hypertension drug combinations using electronic health records of 84.7 million unique patients and showed that a novel drug combination hydrochlorothiazide-digoxin was associated with significantly lower hazards of subsequent hypertension as compared to the monotherapy hydrochlorothiazide alone (HR: 0.769, 95% CI [0.732, 0.807]) and digoxin alone (0.857, 95% CI [0.785, 0.936]). Data-driven informatics analyses reveal that the renin-angiotensin system is involved in the synergistical interactions of hydrochlorothiazide and digoxin on regulating hypertension. The prediction model's code with PyTorch version 1.5 is available at http://nlp.case.edu/public/data/TuSDC/.

RAL GTPases mediate EGFR-driven intestinal stem cell proliferation and tumourigenesis

RAS-like (RAL) GTPases function in Wnt signalling-dependent intestinal stem cell proliferation and regeneration. Whether RAL proteins work as canonical RAS effectors in the intestine and the mechanisms of how they contribute to tumourigenesis remain unclear. Here, we show that RAL GTPases are necessary and sufficient to activate EGFR/MAPK signalling in the intestine, via induction of EGFR internalisation. Knocking down Drosophila RalA from intestinal stem and progenitor cells leads to increased levels of plasma membrane-associated EGFR and decreased MAPK pathway activation. Importantly, in addition to influencing stem cell proliferation during damage-induced intestinal regeneration, this role of RAL GTPases impacts on EGFR-dependent tumourigenic growth in the intestine and in human mammary epithelium. However, the effect of oncogenic RAS in the intestine is independent from RAL function. Altogether, our results reveal previously unrecognised cellular and molecular contexts where RAL GTPases become essential mediators of adult tissue homeostasis and malignant transformation.

A molecular subtype of colorectal cancers initiates independently of epidermal growth factor receptor and has an accelerated growth rate mediated by IL10-dependent anergy

Although epidermal growth factor receptor (EGFR)-targeted therapies are approved for colorectal cancer (CRC) treatment, only 15% of CRC patients respond to EGFR inhibition. Here, we show that colorectal cancers (CRC) can initiate and grow faster through an EGFR-independent mechanism, irrespective of the presence of EGFR, in two different mouse models using tissue-specific ablation of Egfr. The growth benefit in the absence of EGFR is also independent of Kras status. An EGFR-independent gene expression signature, also observed in human CRCs, revealed that anergy-inducing genes are overexpressed in EGFR-independent polyps, suggesting increased infiltration of anergic lymphocytes promotes an accelerated growth rate that is partially caused by escape from cell-mediated immune responses. Many genes in the EGFR-independent gene expression signature are downstream targets of interleukin 10 receptor alpha (IL10RA). We further show that IL10 is detectable in serum from mice with EGFR-independent colon polyps. Using organoids in vitro and Src ablation in vivo, we show that IL10 contributes to growth of EGFR-independent CRCs, potentially mediated by the well-documented role of SRC in IL10 signaling. Based on these data, we show that the combination of an EGFR inhibitor with an anti-IL10 neutralizing antibody results in decreased cell proliferation in organoids and in decreased polyp size in pre-clinical models harboring EGFR-independent CRCs, providing a new therapeutic intervention for CRCs resistant to EGFR inhibitor therapies.

Chemoprevention in familial adenomatous polyposis: past, present and future

Familial adenomatous polyposis (FAP) is a hereditary colorectal cancer syndrome characterized by colorectal adenomas and a near 100% lifetime risk of colorectal cancer (CRC). Prophylactic colectomy, usually by age 40, is the gold-standard therapy to mitigate this risk. However, colectomy is associated with morbidity and fails to prevent extra-colonic disease manifestations, including gastric polyposis, duodenal polyposis and cancer, thyroid cancer, and desmoid disease. Substantial research has investigated chemoprevention medications in an aim to prevent disease progression, postponing the need for colectomy and temporizing the development of extracolonic disease. An ideal chemoprevention agent should have a biologically plausible mechanism of action, be safe and easily tolerated over a prolonged treatment period, and produce a durable and clinically meaningful effect. To date, no chemoprevention agent tested has fulfilled these criteria. New agents targeting novel pathways in FAP are needed. Substantial preclinical literature exists linking the molecular target of rapamycin (mTOR) pathway to FAP. A single case report of rapamycin, an mTOR inhibitor, used as chemoprevention in FAP patients exists, but no formal clinical studies have been conducted. Here, we review the prior literature on chemoprevention in FAP, discuss the rationale for rapamycin in FAP, and outline a proposed clinical trial testing rapamycin as a chemoprevention agent in patients with FAP.

Lethal Poisoning of Cancer Cells by Respiratory Chain Inhibition plus Dimethyl α-Ketoglutarate

Inhibition of oxidative phosphorylation (OXPHOS) by 1-cyclopropyl-4-(4-[(5-methyl-3-(3-[4-(trifluoromethoxy)phenyl]-1,2,4-oxadiazol-5-yl)-1H-pyrazol-1-yl)methyl]pyridin-2-yl)piperazine (BAY87-2243, abbreviated as B87), a complex I inhibitor, fails to kill human cancer cells in vitro. Driven by this consideration, we attempted to identify agents that engage in synthetically lethal interactions with B87. Here, we report that dimethyl α-ketoglutarate (DMKG), a cell-permeable precursor of α-ketoglutarate that lacks toxicity on its own, kills cancer cells when combined with B87 or other inhibitors of OXPHOS. DMKG improved the antineoplastic effect of B87, both in vitro and in vivo. This combination caused MDM2-dependent, tumor suppressor protein p53 (TP53)-independent transcriptional reprogramming and alternative exon usage affecting multiple glycolytic enzymes, completely blocking glycolysis. Simultaneous inhibition of OXPHOS and glycolysis provoked a bioenergetic catastrophe culminating in the activation of a cell death program that involved disruption of the mitochondrial network and activation of PARP1, AIFM1, and APEX1. These results unveil a metabolic liability of human cancer cells that may be harnessed for the development of therapeutic regimens.

Combined chemotherapy with cyclooxygenase-2 (COX-2) inhibitors in treating human cancers: Recent advancement

Chemotherapy with a single chemotherapeutic agent or a combined chemotherapeutic regimen is the clinically standardized treatment for almost all human cancers. Upregulated expression of cyclooxygenase (COX)-2, also known as prostaglandin-endoperoxide synthase (PTGS), is associated with human carcinogenesis and cancer progression and COX-2 inhibitors show antitumor activity in different human cancers. Thus, a combination of chemotherapeutic agents with COX-2 inhibitors has been shown to improve therapeutic effects on human cancers. This review discusses and summarizes recent advances in cancer control and treatment using various antineoplastic drugs combined with COX-2 inhibitors. These combinations showed synergistic antitumor effects. At the gene level, COX-2 inhibitors can reduce inflammatory factors thereby regulating macrophage recruitment for activating the antitumor immune microenvironment; downregulating vascular endothelial growth factor (VEGF) to inhibit tumor angiogenesis; and inhibiting the PI3K/Akt signaling pathway to induce tumor cell apoptosis. In addition, such a combination can reduce toxicity and chemoresistance and enhance radiosensitivity, although COX-2 inhibitors-related cardiotoxicity may potentially affect its use. Further in-depth investigation of these drug combinations is needed to maximize antitumor efficacy and minimize the side effects.

Phosphotyrosine-based Phosphoproteomics for Target Identification and Drug Response Prediction in AML Cell Lines

Acute myeloid leukemia (AML) is a clonal disorder arising from hematopoietic myeloid progenitors. Aberrantly activated tyrosine kinases (TK) are involved in leukemogenesis and are associated with poor treatment outcome. Kinase inhibitor (KI) treatment has shown promise in improving patient outcome in AML. However, inhibitor selection for patients is suboptimal.In a preclinical effort to address KI selection, we analyzed a panel of 16 AML cell lines using phosphotyrosine (pY) enrichment-based, label-free phosphoproteomics. The Integrative Inferred Kinase Activity (INKA) algorithm was used to identify hyperphosphorylated, active kinases as candidates for KI treatment, and efficacy of selected KIs was tested.Heterogeneous signaling was observed with between 241 and 2764 phosphopeptides detected per cell line. Of 4853 identified phosphopeptides with 4229 phosphosites, 4459 phosphopeptides (4430 pY) were linked to 3605 class I sites (3525 pY). INKA analysis in single cell lines successfully pinpointed driver kinases (PDGFRA, JAK2, KIT and FLT3) corresponding with activating mutations present in these cell lines. Furthermore, potential receptor tyrosine kinase (RTK) drivers, undetected by standard molecular analyses, were identified in four cell lines (FGFR1 in KG-1 and KG-1a, PDGFRA in Kasumi-3, and FLT3 in MM6). These cell lines proved highly sensitive to specific KIs. Six AML cell lines without a clear RTK driver showed evidence of MAPK1/3 activation, indicative of the presence of activating upstream RAS mutations. Importantly, FLT3 phosphorylation was demonstrated in two clinical AML samples with a FLT3 internal tandem duplication (ITD) mutation.Our data show the potential of pY-phosphoproteomics and INKA analysis to provide insight in AML TK signaling and identify hyperactive kinases as potential targets for treatment in AML cell lines. These results warrant future investigation of clinical samples to further our understanding of TK phosphorylation in relation to clinical response in the individual patient.

Association of Sulindac and Erlotinib vs Placebo With Colorectal Neoplasia in Familial Adenomatous Polyposis: Secondary Analysis of a Randomized Clinical Trial

Importance

Patients with familial adenomatous polyposis (FAP) are at markedly increased risk for colorectal polyps and cancer. A combination of sulindac and erlotinib led to a 71% reduction in duodenal polyp burden in a phase 2 trial.

Objective

To evaluate effect of sulindac and erlotinib on colorectal adenoma regression in patients with FAP.

Design, Setting, and Participants

Prespecified secondary analysis for colorectal adenoma regression was carried out using data from a double-blind, randomized, placebo-controlled trial, enrolling 92 patients with FAP, conducted from July 2010 to June 2014 in Salt Lake City, Utah.

Interventions

Patients were randomized to sulindac, 150 mg twice daily, and erlotinib, 75 mg daily (n = 46), vs placebo (n = 46) for 6 months.

Main Outcomes and Measurements

The total number of polyps in the intact colorectum, ileal pouch anal anastomosis, or ileo-rectum were recorded at baseline and 6 months. The primary outcomes were change in total colorectal polyp count and percentage change in colorectal polyps, following 6 months of treatment.

Results

Eighty-two randomized patients (mean [SD] age, 40 [13] years; 49 [60%] women) had colorectal polyp count data available for this secondary analysis: 22 with intact colon, 44 with ileal pouch anal anastomosis and 16 with ileo-rectal anastomosis; 41 patients received sulindac/erlotinib and 41 placebo. The total colorectal polyp count was significantly different between the placebo and sulindac-erlotinib group at 6 months in patients with net percentage change of 69.4% in those with an intact colorectum compared with placebo (95% CI, 28.8%-109.2%; P = .009).

Conclusion and Relevance

In this double-blind, placebo-controlled, randomized trial we showed that combination treatment with sulindac and erlotinib compared with placebo resulted in significantly lower colorectal polyp burden after 6 months of treatment. There was a reduction in polyp burden in both those with an entire colorectum and those with only a rectal pouch or rectum.

Trial Registration

clinicaltrials.gov Identifier: NCT01187901.

Inhibition of epidermal growth factor receptor improves antitumor efficacy of vemurafenib in BRAF-mutant human melanoma in preclinical model

Oncogenic activation of the epidermal growth factor receptor (EGFR) signaling pathway occurs in a variety of tumor types, albeit in human melanoma, the contribution of EGFR is still unclear. The potential role of EGFR was analyzed in four BRAF-mutant, one NRAS-mutant and one wild-type NRAS-BRAF-carrying human melanoma cell lines. We have tested clinically available reversible tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib, irreversible EGFR-TKI pelitinib and a reversible experimental compound PD153035 on in-vitro proliferation, apoptosis, migration as well as in-vivo metastatic colonization in a spleen-liver model. The presence of the intracellular domain of EGFR protein and its constitutive activity were demonstrated in all cell lines. Efficacies of EGFR-TKIs showed significant differences, and irreversible inhibition had the strongest antitumor potential. Compared with BRAF-mutant cells, wild-type BRAF was associated with relative resistance against gefitinib. In combination with gefitinib, selective mutant BRAF-inhibitor vemurafenib showed additive effect in all BRAF-mutant cell lines. Treatment of BRAF-mutant cells with gefitinib or pelitinib attenuated in-vitro cell migration and in-vivo colonization. Our preclinical data suggest that EGFR is a potential target in the therapy of BRAF-mutant malignant melanoma; however, more benefits could be expected from irreversible EGFR-TKIs and combined treatment settings.

Clinical development of targeted and immune based anti-cancer therapies

Cancer is currently the second leading cause of death globally and is expected to be responsible for approximately 9.6 million deaths in 2018. With an unprecedented understanding of the molecular pathways that drive the development and progression of human cancers, novel targeted therapies have become an exciting new development for anti-cancer medicine. These targeted therapies, also known as biologic therapies, have become a major modality of medical treatment, by acting to block the growth of cancer cells by specifically targeting molecules required for cell growth and tumorigenesis. Due to their specificity, these new therapies are expected to have better efficacy and limited adverse side effects when compared with other treatment options, including hormonal and cytotoxic therapies. In this review, we explore the clinical development, successes and challenges facing targeted anti-cancer therapies, including both small molecule inhibitors and antibody targeted therapies. Herein, we introduce targeted therapies to epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), human epidermal growth factor receptor 2 (HER2), anaplastic lymphoma kinase (ALK), BRAF, and the inhibitors of the T-cell mediated immune response, cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein-1 (PD-1)/ PD-1 ligand (PD-1 L).

Cancer driver G-protein coupled receptor (GPCR) induced β-catenin nuclear localization: the transcriptional junction

G protein-coupled receptors (GPCRs) comprise the main signal-transmitting components in the cell membrane. Over the past several years, biochemical and structural analyses have immensely enhanced our knowledge of GPCR involvement in health and disease states. The present review focuses on GPCRs that are cancer drivers, involved in tumor growth and development. Our aim is to highlight the involvement of stabilized β-catenin molecular machinery with a specific array of GPCRs. We discuss recent advances in understanding the molecular path leading to β-catenin nuclear localization and transcriptional activity and their implications for future cancer therapy research.

Colorectal cancer prevention: Immune modulation taking the stage

Prevention or early detection is one of the most promising strategies against colorectal cancer (CRC), the second leading cause of cancer death in the US. Recent studies indicate that antitumor immunity plays a key role in CRC prevention. Accumulating evidence suggests that immunosurveillance represents a critical barrier that emerging tumor cells have to overcome in order to sustain the course of tumor development. Virtually all of the agents with cancer preventive activity have been shown to have an immune modulating effect. A number of immunoprevention studies aimed at triggering antitumor immune response against early lesions have been performed, some of which have shown promising results. Furthermore, the recent success of immune checkpoint blockade therapy reinforces the notion that cancers including CRC can be effectively intervened via immune modulation including immune normalization, and has stimulated various immune-based combination prevention studies. This review summarizes recent advances to help better harness the immune system in CRC prevention.

Methods of selecting combination therapy for colorectal cancer patients: a patent evaluation of US20160025730A1

INTRODUCTION

Colorectal cancer (CRC) is the fourth most common cancer worldwide. Targeted therapy drugs (TTDs) are a valid treatment, epithelial growth factor receptor (EGFR) inhibitors being one of the most commonly used for CRC patients. However, this treatment is only useful for patients with wild-type KRAS (wtKRAS) and is effective only on about 40 to 60% of this subset due to the high plasticity of ErbB network. Areas covered: The invention proposes the use of ErbB protein levels and ErbB receptor dimer formation as biomarkers for selecting, predicting and monitoring CRC patients showing sensitivity to the action of EGFR inhibitors to benefit from the combination therapy of EGFR and HER2 inhibitors. The in vitro data on Lim1215 cells suggest the over-activation of HER3 signaling pathway in response to the use of EGFR inhibitors on monotherapy; the use of HER2 or HER3 or MEK inhibitors in combination with EGFR inhibitors reversed this activation. Expert opinion: To assess the clinical applicability of this invention, further studies are needed since the conclusions are derived solely based on the data obtained from only one CRC cell line (Lim1215). Furthermore, other biofactors/mutations should be considered to assure the potential benefits of the combination therapies proposed.

Covalent EGFR Inhibitors: Binding Mechanisms, Synthetic Approaches, and Clinical Profiles

Being overexpressed in several types of cancer, the epidermal growth factor receptor (EGFR) is considered one of the key therapeutic targets in oncology. Although many first-generation EGFR inhibitors had been FDA approved for the treatment of certain types of cancer, patients soon developed resistance to these reversible ATP competitive inhibitors via mutations in the kinase domain of EGFR. A new trend was adopted to design covalent irreversible inhibitors, that is, second- and third-generation inhibitors. Second-generation inhibitors can inhibit the mutant forms but, unfortunately, they had dose limiting side effects due to wild-type EGFR inhibition. Third-generation inhibitors emerged shortly, which were capable of inhibiting the mutant forms exclusively while sparing the wild type. Many other strategies have also been developed to reduce the risk of covalent interactions with off-targets, thus improving the pharmacokinetic and/or pharmacodynamic profile of the antiproliferative agents. In this review, we focused mainly on second- and third-generation EGFR inhibitors, their binding mechanisms (either docking studies or co-crystallized structures), their synthetic approaches, clinical profiles, and limitations.

Effect of Sulindac and Erlotinib vs Placebo on Duodenal Neoplasia in Familial Adenomatous Polyposis: A Randomized Clinical Trial

IMPORTANCE

Patients with familial adenomatous polyposis (FAP) are at markedly increased risk for duodenal polyps and cancer. Surgical and endoscopic management of duodenal neoplasia is difficult and chemoprevention has not been successful.

OBJECTIVE

To evaluate the effect of a combination of sulindac and erlotinib on duodenal adenoma regression in patients with FAP.

DESIGN, SETTING, AND PARTICIPANTS

Double-blind, randomized, placebo-controlled trial, enrolling 92 participants with FAP, conducted from July 2010 through June 2014 at Huntsman Cancer Institute in Salt Lake City, Utah.

INTERVENTIONS

Participants with FAP were randomized to sulindac (150 mg) twice daily and erlotinib (75 mg) daily (n = 46) vs placebo (n = 46) for 6 months.

MAIN OUTCOMES AND MEASURES

The total number and diameter of polyps in the proximal duodenum were mapped at baseline and 6 months. The primary outcome was change in total polyp burden at 6 months. Polyp burden was calculated as the sum of the diameters of polyps. The secondary outcomes were change in total duodenal polyp count, change in duodenal polyp burden or count stratified by genotype and initial polyp burden, and percentage of change from baseline in duodenal polyp burden.

RESULTS

Ninety-two participants (mean age, 41 years [range, 24-55]; women, 56 [61%]) were randomized when the trial was stopped by the external data and safety monitoring board because the second preplanned interim analysis met the prespecified stopping rule for superiority. Grade 1 and 2 adverse events were more common in the sulindac-erlotinib group, with an acne-like rash observed in 87% of participants receiving treatment and 20% of participants receiving placebo (P < .001). Only 2 participants experienced grade 3 adverse events. [table: see text].

CONCLUSIONS AND RELEVANCE

Among participants with FAP, the use of sulindac and erlotinib compared with placebo resulted in a lower duodenal polyp burden after 6 months. Adverse events may limit the use of these medications at the doses used in this study. Further research is necessary to evaluate these preliminary findings in a larger study population with longer follow-up to determine whether the observed effects will result in improved clinical outcomes.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT 01187901.

An Advanced Histologic Method for Evaluation of Intestinal Adenomas in Mice Using Digital Slides

Background and Methods

Mice are used for modelling the biology of many human diseases, including colorectal cancer (CRC). Mouse models recapitulate many aspects of human disease and are invaluable tools for studying the biology, treatment and prevention of CRC. Unlike humans, many mouse models develop lesions primarily in the small intestine, which necessitates removal and examination of this organ in order to evaluate treatment efficacy. Commonly, the small intestine is visually examined for gross lesions and then selectively embedded in paraffin blocks for further microscopic analysis. Unfortunately, this method suffers from inherent bias toward counting large lesions and simultaneously missing smaller lesions. Even more, this method leaves no permanent record of diagnosed and measured lesions. We evaluated inter-observer variability in a mouse model of CRC using visual examination, and directly compared the visual, gross examination with a histologic analytic method using digital slides of hematoxylin and eosin stained tissue sections.

Results

Using visual examination, there was a high degree of inter-observer variability. As this method does not provide a permanent record of measurements, there is no capability to arbitrate between differing observations. In contrast, histologic analysis allowed for the creation of a permanent record of lesion measurements taken. When compared directly, histologic analysis of annotated digital images has significantly improved accuracy. Using this method we were able to distinguish mutant mice from wild type littermates even at a very young age. With gross visual examination, this distinction was not possible.

Conclusion

Histologic analysis of digital images of murine intestinal tissue provides a vital improvement over the commonly used visual, gross examination method. Unlike visual gross examination, histologic analysis is not biased by the size of intestinal adenoma, misdiagnosis of another lesion type, or presence of a Peyer’s patch. It also provides accountability in the form of a permanent record of lesions counted. Histologic analysis using digital slides represents a critical improvement over the current, widely used method of visual gross examination and should be considered for future studies using mouse models of CRC.

Cancer stem cells in drug resistant lung cancer: Targeting cell surface markers and signaling pathways

Lung cancer is the leading cause of cancer mortality worldwide. Despite advances in anti-cancer therapies such as chemotherapy, radiotherapy and targeted therapies, five-year survival rates remain poor (<15%). Inherent and acquired resistance has been identified as a key factor in reducing the efficacy of current cytotoxic therapies in the management of non-small cell lung cancer (NSCLC). There is growing evidence suggesting that cancer stem cells (CSCs) play a critical role in tumor progression, metastasis and drug resistance. Similar to normal tissue stem cells, CSCs exhibit significant phenotypic and functional heterogeneity. While CSCs have been reported in a wide spectrum of human tumors, the biology of CSCs in NSCLC remain elusive. Current anti-cancer therapies fail to eradicate CSC clones and instead, favor the expansion of the CSC pool and select for resistant CSC clones thereby resulting in treatment resistance and subsequent relapse in these patients. The identification of CSC-specific marker subsets and the targeted therapeutic destruction of CSCs remains a significant challenge. Strategies aimed at efficient targeting of CSCs are becoming increasingly important for monitoring the progress of cancer therapy and for evaluating new therapeutic approaches. This review focuses on the current knowledge of cancer stem cell markers in treatment-resistant lung cancer cells and the signaling cascades activated by these cells to maintain their stem-like properties. Recent progress in CSC-targeted drug development and the current status of novel agents in clinical trials are also reviewed.

State-of-the-art of small molecule inhibitors of the TAM family: the point of view of the chemist

The TAM family of tyrosine kinases receptors (Tyro3, Axl and Mer) is implicated in cancer development, autoimmune reactions and viral infection and is therefore emerging as an effective and attractive therapeutic target. To date, only a few small molecules have been intentionally designed to block the TAM kinases, while most of the inhibitors were developed for blocking different protein kinases and then identified through selectivity profile studies. This minireview will examine in terms of chemical structure the different compounds able to act on either one, two or three TAM kinases with details about structure-activity relationships, drug-metabolism and pharmacokinetics properties where they exist.

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.

In Vivo Antineoplastic Effects of the NSAID Sulindac in an Oral Carcinogenesis Model

The antineoplastic properties of the NSAID sulindac have long been studied. The purpose of this study was to explore sulindac's in vivo effects on oral squamous cell carcinoma (SCC) oncogenesis using the hamster cheek pouch oral carcinogenesis model (HOCM). Thirty Syrian golden hamsters were divided into three experimental and two control groups (n = 6 each). The animals' right buccal pouches were treated with carcinogen for 9 weeks in one experimental and one control group and for 14 weeks in all other three groups. The animals of two experimental groups received sulindac from the 1st week and those of the third experimental group from the 10th week. After the end of carcinogenesis, treated buccal pouches were removed and examined. In animals treated with carcinogen for 14 weeks, development of oral SCC and tumor volume were significantly lower in animals that received sulindac from the first week of the experiment. Oral SCC developing in animals that received sulindac were more frequently well differentiated compared with the control group. In animals treated with carcinogen for 9 weeks, the animals that received sulindac developed lower grade of epithelial dysplasia. Proliferation index Ki-67 and positivity for the antiapoptotic molecule survivin were lower in the animals that received sulindac. Treatment with sulindac appears to delays the progression of oral premalignant lesions to oral SCC in the HOCM, also resulting in smaller and better differentiated tumors. These in vivo antineoplastic effects may be related to sulindac's ability to decrease cell proliferation and to prevent survivin expression.

Aspirin Prevents Colorectal Cancer by Normalizing EGFR Expression

BACKGROUND

Aspirin intake reduces the risk of colorectal cancer (CRC), but the molecular underpinnings remain elusive. Epidermal growth factor receptor (EGFR), which is overexpressed in about 80% of CRC cases, is implicated in the etiology of CRC. Here, we investigated whether aspirin can prevent CRC by normalizing EGFR expression.

METHODS

Immunohistochemistry staining was performed on paraffin-embedded tissue sections from normal colon mucosa, adenomatous polyps from FAP patients who were classified as regular aspirin users or nonusers. The interplay between cyclooxygenase-2 (COX-2) and EGFR was studied in primary intestinal epithelial cells isolated from Apc^Min mice, immortalized normal human colon epithelial cells (HCEC) as well as murine embryonic fibroblasts (MEFs).

RESULTS

Immunohistochemistry staining results established that EGFR overexpression is an early event in colorectal tumorigenesis, which can be greatly attenuated by regular use of aspirin. Importantly, EGFR and COX-2 were co-overexpressed and co-localized with each other in FAP patients. Further mechanistic studies revealed that COX-2 overexpression triggers the activation of the c-Jun-dependent transcription factor, activator protein-1 (AP-1), which binds to the Egfr promoter. Binding facilitates the cellular accumulation of EGFR and lowers the threshold required for pre-neoplastic cells to undergo transformation.

CONCLUSION

Aspirin might exert its chemopreventive activity against CRC, at least partially, by normalizing EGFR expression in gastrointestinal precancerous lesions.

Development of Small Molecules Targeting the Wnt Signaling Pathway in Cancer Stem Cells for the Treatment of Colorectal Cancer

Colorectal cancer (CRC) was ranked third in morbidity and mortality in the United States in 2013. Although substantial progress has been made in surgical techniques and postoperative chemotherapy in recent years, the prognosis for colon cancer is still not satisfactory, mainly because of cancer recurrence and metastasis. The latest studies have shown that cancer stem cells (CSCs) play important roles in cancer recurrence and metastasis. Drugs that target CSCs might therefore have great therapeutic potential in prevention of cancer recurrence and metastasis. The wingless-int (Wnt) signaling pathway in CSCs has been suggested to play crucial roles in colorectal carcinogenesis, and has become a popular target for anti-CRC therapy. Dysregulation of the Wnt signaling pathway, mostly by inactivating mutations of the adenomatous polyposis coli tumor suppressor or oncogenic mutations of β-catenin, has been implicated as a key factor in colorectal tumorigenesis. Abnormal increases of β-catenin levels represents a common pathway in Wnt signaling activation and is also observed in other human malignancies. These findings highlight the importance of developing small-molecule drugs that target the Wnt pathway. Herein we provide an overview on the current development of small molecules that target the Wnt pathway in colorectal CSCs and discuss future research directions.

Downregulation of PI3-K/Akt/PTEN pathway and activation of mitochondrial intrinsic apoptosis by Diclofenac and Curcumin in colon cancer

Phosphatidylinositol 3-kinase (PI3-K)/PTEN/Akt signaling is over activated in various tumors including colon cancer. Activation of this pathway regulates multiple biological processes such as apoptosis, metabolism, cell proliferation, and cell growth that underlie the biology of a cancer cell. In the present study, the chemopreventive effects have been observed of Diclofenac, a preferential COX-2 inhibitory non-steroidal anti-inflammatory drugs, and Curcumin, a natural anti-inflammatory agent, in the early stage of colorectal carcinogenesis induced by 1,2-dimethylhydrazine dihydrochloride in rats. The tumor-promoting role of PI3-K/Akt/PTEN signal transduction pathway and its association with anti-apoptotic family of proteins are also observed. Both Diclofenac and Curcumin downregulated the PI3-K and Akt expression while promoting the apoptotic mechanism. Diclofenac and Curcumin administration significantly increased the expression of pro-apoptotic Bcl-2 family members (Bad and Bax) while decreasing the anti-apoptotic Bcl-2 protein. An up-regulation of cysteine protease family apoptosis executioner, such as caspase-3 and -9, is seen. Diclofenac and Curcumin inhibited the Bcl-2 protein by directly interacting at the active site by multiple hydrogen bonding, as also evident by negative glide score of Bcl-2. These drugs stimulated apoptosis by increasing reactive oxygen species (ROS) generation and simultaneously decreasing the mitochondrial membrane potential (ΔΨ M). Diclofenac and Curcumin showed anti-neoplastic effects by downregulating PI3-K/Akt/PTEN pathway, inducing apoptosis, increasing ROS generation, and decreasing ΔΨ M. The anti-neoplastic and apoptotic effects were found enhanced when both Diclofenac and Curcumin were administered together, rather than individually.

Simultaneous blockage of epidermal growth factor receptor and cyclooxygenase-2 in a human xenotransplanted lung cancer model

The effects of erlotinib combined with celecoxib in a lung cancer xenograft model were here explored with a focus on possible mechanisms. A xenotransplanted lung cancer model was established in nude mice using the human lung cancer cell A549 cell line and animals demonstrating tumour growth were randomly divided into four groups: control, erlotinib, celecoxib and combined (erotinib and celecoxib). The tumor major axis and short diameter were measured twice a week and after 40 days tissues were collected for immunohistochemical analyses of Bcl-2 and Bax positive cells and Western-blotting analyses for the epidermal growth factor recepto (EGFR), P-EGFR, and cyclooxygenase-2 (COX-2). Tumor size in the combined group was smaller than in the others (p<0.01) and the percentage of Bcl-2 positive cells was fewer in most cases (p<0.01), while that of Bax positive cells was greater than in the erlotinib and celecoxib groups (P>0.05). Western blotting showed decreased expression of P-EGFR and COX-2 with both erlotinib and celecoxib treatments, but most pronouncedly in the combined group (P<0.05). Simultaneous blockage of the EGFR and COX-2 signal pathways exerted stronger growth effects in our human xenotransplanted lung cancer model than inhibition of either pathway alone. The anti-tumor effects were accompanied by synergetic inhibition of tumor cell apoptosis, activation of p-EGFR and expression of COX-2.

Differential control of growth, apoptotic activity and gene expression in human colon cancer cells by extracts derived from medicinal herbs, Rhazya stricta and Zingiber officinale and their combination

AIM

To investigate the effects of extracts from Rhazya stricta (R. stricta) and Zingiber officinale (Z. officinale) on human colorectal cancer cells.

METHODS

Human colorectal cancer cells (HCT116) were subjected to increasing doses of crude alkaloid extracts from R. stricta (CAERS) and crude flavonoid extracts from Z. officinale (CFEZO). Cells were then harvested after 24, 48 or 72 h and cell viability was examined by trypan blue exclusion dye test; clonogenicity and soft agar colony-forming assays were also carried out. Nuclear stain (Hoechst 33342), acridine orange/ethidium bromide double staining, agarose gel electrophoresis and comet assays were performed to assess pro-apoptotic potentiality of the extracts. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR), using gene-specific primers and Western blot analyses were performed to assess the impact of CAERS and CFEZO on the expression levels of key regulatory proteins in HCT116 cells.

RESULTS

Treatment with a combination of CAERS and CFEZO synergistically suppressed the proliferation, colony formation and anchorage-independent growth of HCT116 cells. Calculated IC50, after 24, 48 and 72 h, were 70, 90 and 130 μg/mL for CAERS, 65, 85 and 120 μg/mL for CFEZO and 20, 25 and 45 μg/mL for both agents, respectively. CAERS- and CFEZO-treated cells exhibited morphologic and biochemical features of apoptotic cell death. The induction of apoptosis was associated with the release of mitochondrial cytochrome c, an increase in the Bax/Bcl-2 ratio, activation of caspases 3 and 9 and cleavage of poly ADP-ribose polymerase. CAERS and CFEZO treatments downregulated expression levels of anti-apoptotic proteins including Bcl-2, Bcl-X, Mcl-1, survivin and XIAP, and upregulated expression levels of proapoptotic proteins such as Bad and Noxa. CAERS and CFEZO treatments elevated expression levels of the oncosuppressor proteins, p53, p21 and p27, and reduced levels of the oncoproteins, cyclin D1, cyclin/cyclin-dependent kinase-4 and c-Myc.

CONCLUSION

These data suggest that a combination of CAERS and CFEZO is a promising treatment for the prevention of colon cancer.

Effects of crude extracts from medicinal herbs Rhazya stricta and Zingiber officinale on growth and proliferation of human brain cancer cell line in vitro

Hitherto, limited clinical impact has been achieved in the treatment of glioblastoma (GBMs). Although phytochemicals found in medicinal herbs can provide mankind with new therapeutic remedies, single agent intervention has failed to bring the expected outcome in clinical trials. Therefore, combinations of several agents at once are gaining increasing attractiveness. In the present study, we investigated the effects of crude alkaloid (CAERS) and flavonoid (CFEZO) extracts prepared from medicinal herbs, Rhazya stricta and Zingiber officinale, respectively, on the growth of human GBM cell line, U251. R. stricta and Z. officinale are traditionally used in folkloric medicine and have antioxidant, anticarcinogenic, and free radical scavenging properties. Combination of CAERS and CFEZO treatments synergistically suppressed proliferation and colony formation and effectively induced morphological and biochemical features of apoptosis in U251 cells. Apoptosis induction was mediated by release of mitochondrial cytochrome c, increased Bax : Bcl-2 ratio, enhanced activities of caspase-3 and -9, and PARP-1 cleavage. CAERS and CFEZO treatments decreased expression levels of nuclear NF-κBp65, survivin, XIAP, and cyclin D1 and increased expression level of p53, p21, and Noxa. These results suggest that combination of CAERS and CFEZO provides a useful foundation for studying and developing novel chemotherapeutic agents for the treatment of GBM.

Therapeutic melting pot of never in mitosis gene a related kinase 2 (Nek2): a perspective on Nek2 as an oncology target and recent advancements in Nek2 small molecule inhibition

The global incidence of cancer is on the rise, and within the next decade, the disease is expected to become the leading cause of death worldwide. Forthcoming strategies used to treat cancers focus on the design and implementation of multidrug therapies to target complementary cancer specific pathways. A more direct means by which this multitargeted approach can be achieved is by identifying and targeting interpathway regulatory factors. Recent advances in understanding Nek2 (NIMA related kinase 2) biology suggest that the kinase potentially represents a multifaceted therapeutic target. In this regard, pharmacologic modulation of Nek2 with a single agent may effect several mechanisms important for tumor growth, survival, progression, and metastasis. We herein review the development of Nek2 as an oncology target and provide a succinct chronology of drug discovery campaigns focused on targeting Nek2.

Targeting events in melanoma carcinogenesis for the prevention of melanoma

Melanoma is one of the few tumors that have increased in incidence over the last few decades. Strategies devoted solely to protecting against ultraviolet radiation have, at best, had a modest impact on the development of melanoma. Chemoprevention is an under-explored approach that could significantly decrease the morbidity and mortality from this deadly cancer. However, the scientific and logistical challenges of performing clinical studies in chemoprevention require innovative approaches to prove the effectiveness of putative preventive agents. There are several pharmacological and nutriceutical agents that are mechanistically linked to events in melanoma carcinogenesis that are candidates for advanced human studies. We will review the data for several promising agents, including statins, curcumin, resveratrol, silymarin and green tea, and discuss some importance issues and concepts that should be considered in any melanoma chemoprevention strategy.

Erlotinib in the treatment of non-small cell lung cancer

Inhibition of the epidermal growth factor receptor is one of the most promising novel therapeutic strategies to be used in the treatment of patients with non-small cell lung cancer. A number of compounds that target the epidermal growth factor receptor are in an advanced stage of clinical development including both antibodies directed against the receptor and small molecule inhibitors of epidermal growth factor receptor tyrosine kinase activity. This drug profile focuses on the development of erlotinib, an orally available inhibitor of epidermal growth factor receptor tyrosine kinase. Results of clinical trials are reviewed, two trials of erlotinib in combination, one with paclitaxel and carboplatin, the other with gemcitabine and cisplatin, and the National Cancer Institute of Canada--Clinical Trials Group BR21, the first study to demonstrate a survival benefit for this class of compound in non-small cell lung cancer. The future role of erlotinib in the management of patients with non-small cell lung cancer is also discussed.

Predicting response to epidermal growth factor receptor-targeted therapy in colorectal cancer

The discovery over 20 years ago by the Nobel Laureate Stanley Cohen of epidermal growth factor and its receptor, followed by the recognition that this receptor is overexpressed in multiple cancer types, has been of phenomenal significance. From these events the 'Holy Grail' of targeted therapy has looked increasingly realistic. Over the last 5 years this work has come of age with the licensing of multiple agents targeting this important mitogenic pathway in multiple tumor types. However, these agents and the technology behind them, while impressive, have resulted in lower clinical response rates than anticipated. In this review we will focus on the epidermal growth factor receptor-targeted therapies in colorectal cancer, why our expectations from these therapies have not yet been fulfilled and how we may predict those cancers that are likely to respond or be resistant to these therapies through a greater appreciation of the intricacy, diversity and dynamism of cellular signaling mechanisms.

CXCR2 inhibition enhances sulindac-mediated suppression of colon cancer development

Small chemical compound sulindac has been approved as a preventive approach against colon cancer for its effectiveness in treatment of precancerous adenoma. Due to its severe toxicities in the cardiovascular, gastrointestinal and renal systems, however, a combination of low-dose sulindac with other chemopreventive agents has been sought after as an alternative therapeutic strategy that could increase its effectiveness, while minimizing its adverse effects. To identify the promising alternative approach, we investigated the therapeutic potential of targeting the interleukin (IL)-8/CXCR2 pathway in colon cancer treatment using both loss-of-function (CXCR2 knockout) and gain-of-function (IL-8 overexpression) mouse models, as the IL-8/CXCR2 pathway has been shown to be activated in intestinal tumors of both human and experimental animals. We found that deletion of CXCR2 gene and ectopic expression of IL-8 suppresses and enhances, respectively, intestinal tumor development caused by a mutation in the APC gene. Moreover, a single copy deletion of CXCR2 gene resulted in abrogation of COX-2 and Gro-α upregulation in intestinal tumors caused by the APC mutation. Moreover, a single copy (heterozygote) deletion of CXCR2 gene was sufficient to synergize with a low-dose sulindac treatment in suppressing APCmin-induced intestinal polyposis. Together, our study provides a therapeutic justification of combined inhibition of CXCR2 and sulindac treatment in colon cancer prevention.

Co-delivery of doxorubicin and curcumin by polymeric micelles for improving antitumor efficacy on breast carcinoma

Polymeric micelles co-delivered hydrophilic doxorubicin and hydrophobic curcumin improved cytotoxicity, apoptosis, and cellular uptakein vitroand enhanced antitumor and anti-metastasis activityin vivoon breast carcinoma.

Protective effects of Huang-Lian-Jie-Du-Tang and its component group on collagen-induced arthritis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Huang-Lian-Jie-Du-Tang is a famous Traditional Chinese medicine consisting of Rhizoma coptidis (Coptis chinensis Franch, Ranunculaceae), Radix scutellariae (Scutellaria baicalensis Georgi, Labiatae), Cortex phellodendri (Phellodendron amurense Rupr. Rutaceae) and Fructus gardeniae (Gardenia jasminoide Ellis, Rubiaceae) in a weight ratio of 3:2:2:3.This formula was described by Wang Tao (in the Chinese Tang Dynasty) in his treatise "Wai Tai Mi Yao". It has been used to treat inflammation, hypertension, gastrointestinal disorders, and liver and cerebrovascular diseases in the clinical practice of Traditional Chinese medicine, especially in treating inflammation for nearly two thousand years. However, the essential compounds in it have not been identified, and the mechanisms remain to be addressed. To investigate the protective effects of HLJDT and its component group (HLJDT-CG) on collagen-induced arthritis in rats.

MATERIALS AND METHODS

CIA was established in male Wistar rats with subcutaneous injection of type II bovine collagen at the base of the tail of animals. CIA rats were treated daily with oral administration of HLJDT aqueous extracts (270 mg/kg) or HLJDT-CG (40 mg/kg) once per day from day 6 to day 28. Rats in normal and vehicle control groups were given an equal volume of vehicle (0.9% saline) and 0.025 mg/kg Dexamethasone was given to the Standard group at the same time. The protective effect of them were assessed by measuring arthritis index, swelling, the cytokines such as TNF-α, IFN-γ and IL-17 in serum, type II collagen antibodies, splenocyte proliferation and so on.

RESULTS

The results demonstrated that treatment of CIA rat with either HLJDT aqueous extracts or HLJDT-CG not only ameliorated the symptoms of arthritis, prevented joint damage but also reduced the serum levels of TNF-α, IFN-γ and IL-17 in CIA rats. Anti-CII antibodies showed the similar trend except that of IgG1. Furthermore, HLJDT aqueous extracts and HLJDT-CG administration also suppressed CII-induced proliferative response of splenocytes. More importantly, HLJDT-CG exhibited similar pharmacological activities as HLJDT aqueous extracts in all aforementioned experiments.

CONCLUSIONS

HLJDT aqueous extracts and HLJDT-CG could effectively ameliorate CII-induced arthritis and significantly suppress the immune response against CII with similar pharmacological efficacy. These findings suggest that HLJDT has therapeutic potential in RA treatment and HLJDT-CG can represent the effective-composite of HLJDT.

EGF receptor and COX-1/COX-2 enzyme proteins as related to corresponding mRNAs in human per-operative biopsies of colorectal cancer

Background

Cyclooxygenase (COX) and epidermal growth factor receptor (EGFR) activities promote progression of colorectal cancer. Combined treatment against these targets has not been more effective than single treatments alone. Therefore, our aim was to analyze relationships between COX and EGFR in peroperative colorectal tumor biopsies.

Method

Tumor and colon mucosa tissue were collected at primary intended curative operations in patients according to well-recognized statistical distributions of tumor stages in colorectal cancer. COX-1, COX-2 and EGFR content in tumor and colon mucosa tissue were quantified by western blot and Q-PCR.

Results

COX-2 protein appeared as two bands, one at 66 kDa in almost all tumor and mucosa samples and one at 74 kDa in 73% of the tumors and in 23% of the mucosa samples. Tumor COX-2 mRNA was not different from the content in mucosa samples, while COX-2 protein was increased in tumor tissue (p < 0.0003). A correlation between 74 kDa COX-2 protein and COX-2 mRNA occurred in tumor tissue, with significantly increasing COX-2 mRNA across tumor stages. EGFR mRNA content was lower in tumor tissue (p < 0.0001), while EGFR protein was similar in tumor and mucosa samples. COX-2 and EGFR proteins showed a positive correlation in mucosa, while a negative correlation occurred in tumor tissue. Tumor tissue with high COX-2 74 kDa protein lacked EGFR protein.

Conclusion

Our present results are compatible with the theory that COX-2 and EGFR signalling pathways are inversely related in colorectal cancer tissue. This may explain why combinatorial clinical treatments have been less rewarding.

Effects of EGFR Inhibitor on Helicobacter pylori Induced Gastric Epithelial Pathology in Vivo

Helicobacter pylori transactivates the Epidermal Growth Factor Receptor (EGFR) and predisposes to gastric cancer development in humans and animal models. To examine the importance of EGFR signalling to gastric pathology, this study investigated whether treatment of Mongolian gerbils with a selective EGFR tyrosine kinase inhibitor, EKB-569, altered gastric pathology in chronic H. pylori infection. Gerbils were infected with H. pylori and six weeks later received either EKB-569-supplemented, or control diet, for 32 weeks prior to sacrifice. EKB-569-treated H. pylori-infected gerbils had no difference in H. pylori colonisation or inflammation scores compared to infected animals on control diet, but showed significantly less corpus atrophy, mucous metaplasia and submucosal glandular herniations along with markedly reduced antral and corpus epithelial proliferation to apoptosis ratios. EKB-569-treated infected gerbils had significantly decreased abundance of Cox-2, Adam17 and Egfr gastric transcripts relative to infected animals on control diet. EGFR inhibition by EKB-569 therefore reduced the severity of pre-neoplastic gastric pathology in chronically H. pylori-infected gerbils. EKB-569 increased gastric epithelial apoptosis in H. pylori-infected gerbils which counteracted some of the consequences of increased gastric epithelial cell proliferation. Similar chemopreventative strategies may be useful in humans who are at high risk of developing H. pylori- induced gastric adenocarcinoma.

Modeling of non-steroidal anti-inflammatory drug effect within signaling pathways and miRNA-regulation pathways

To date, it is widely recognized that Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) can exert considerable anti-tumor effects regarding many types of cancers. The prolonged use of NSAIDs is highly associated with diverse side effects. Therefore, tailoring down the NSAID application onto individual patients has become a necessary and relevant step towards personalized medicine. This study conducts the systemsbiological approach to construct a molecular model (NSAID model) containing a cyclooxygenase (COX)-pathway and its related signaling pathways. Four cancer hallmarks are integrated into the model to reflect different developmental aspects of tumorigenesis. In addition, a Flux-Comparative-Analysis (FCA) based on Petri net is developed to transfer the dynamic properties (including drug responsiveness) of individual cellular system into the model. The gene expression profiles of different tumor-types with available drug-response information are applied to validate the predictive ability of the NSAID model. Moreover, two therapeutic developmental strategies, synthetic lethality and microRNA (miRNA) biomarker discovery, are investigated based on the COX-pathway. In conclusion, the result of this study demonstrates that the NSAID model involving gene expression, gene regulation, signal transduction, protein interaction and other cellular processes, is able to predict the individual cellular responses for different therapeutic interventions (such as NS-398 and COX-2 specific siRNA inhibition). This strongly indicates that this type of model is able to reflect the physiological, developmental and pathological processes of an individual. The approach of miRNA biomarker discovery is demonstrated for identifying miRNAs with oncogenic and tumor suppressive functions for individual cell lines of breast-, colon- and lung-tumor. The achieved results are in line with different independent studies that investigated miRNA biomarker related to diagnostics of cancer treatments, therefore it might shed light on the development of biomarker discovery at individual level. Particular results of this study might contribute to step further towards personalized medicine with the systemsbiological approach.

Combination of selenium and green tea improves the efficacy of chemoprevention in a rat colorectal cancer model by modulating genetic and epigenetic biomarkers

Dietary supplementation of selenium and green tea holds promise in cancer prevention. In this study, we evaluated the efficacies of selenium and green tea administered individually and in combination against colorectal cancer in an azoxymethane (AOM)-induced rat colonic carcinogenesis model and determined the underlying mechanisms of the protection. Four-week old Sprague-Dawley male rats were fed with diets containing 0.5% green tea extract, 1 ppm selenium as selenium-enriched milk protein, or combination of 1 ppm selenium and 0.5% green tea extract. Animals received 2 AOM (15 mg/kg) treatments to induce colonic oncogenesis. Rats were killed 8 or 30 wk later after the last AOM to examine the effect of dietary intervention on aberrant crypt foci (ACF) formation or tumor development. On sacrifice, colons were examined for ACF and tumors, the mRNA levels of SFRP5 and Cyclin D1, and the proteins levels of ß-catenin, COX-2, Ki-67, DNMT1 and acetyl histone H3. The combination of selenium and green tea resulted in a significant additive inhibition of large ACF formation, this effect was greater than either selenium or green tea alone, P<0.01; the combination also had a significant additive inhibition effect on all tumor endpoints, the effect of the combination diet on tumor incidence, multiplicity and size was greater than selenium or green tea alone, P<0.01. Rats fed the combination diet showed marked reduction of DNMT1 expression and induction of histone H3 acetylation, which were accompanied by restoration of SFRP5 mRNA in normal-appearing colonic crypts. The combination diet also significantly reduced ß-catenin nuclear translocation, Cyclin D1 expression and cell proliferation. These data show, for the first time, that combination of selenium and green tea is more effective in suppressing colorectal oncogenesis than either agent alone. The preventive effect is associated with regulation of genetic and epigenetic biomarkers implicated in colonic carcinogenesis.

APC loss-induced intestinal tumorigenesis in Drosophila: Roles of Ras in Wnt signaling activation and tumor progression

Adenomatous polyposis coli (APC) and K-ras are the two most frequently mutated genes found in human colorectal cancers. In human colorectal cancers, Wnt signaling activation after the loss of APC is hypothesized to be the key event for adenoma initiation, whereas additional mutations such as Ras activation are required for the progression from adenoma to carcinoma. However, accumulating data have led to conflicting views regarding the precise role of Ras in APC loss-induced tumorigenesis. Here, using Drosophila midgut as a model system, we show that in the absence of Ras, APC mutant epithelial cells cannot initiate hyperplasia, suggesting that Ras plays an essential role in tumor initiation. Conversely, activating Ras by expressing oncogenic Ras or Raf in APC-deficient cells led to a blockage of cell differentiation and to preinvasive tumor outgrowth, characteristics that are shared by advanced colorectal carcinoma in humans. Mechanistically, we find that Ras is not required for Wnt signaling activation after APC loss, although Ras hyperactivation is able to potentiate Wnt signaling by increasing the cytoplasmic and nuclear accumulation of Armadillo/β-catenin via mechanisms independent of JNK/Rac1 or PI3K-Akt signaling, partly owing to the downregulation of DE-cadherin. Together with the data from gene expression analyses, our results indicate that both parallel and cooperative mechanisms of Wnt and Ras signaling are responsible for the initiation and progression of intestinal tumorigenesis after APC loss.

Expression of EGFR, HER2, phosphorylated ERK and phosphorylated MEK in colonic neoplasms of familial adenomatous polyposis patients

PURPOSE

The expression of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) is associated with poor prognosis in sporadic colorectal carcinoma (CRC). EGFR inhibitors are approved for the treatment of refractory CRC. The aim of this study was to investigate the expression of EGFR and HER2 and downstream extracellular signal regulated kinase (ERK) and mitogen activated protein kinase (MAPK) in non-neoplastic colonic mucosa, adenomas and carcinomas from familial adenomatous polyposis coli (FAP) patients, exploring the expression along the adenoma-carcinoma sequence.

METHODS

The expression of EGFR, HER2, phosphorylated MAPK/ERK kinase (pMEK) and phosphorylated ERK (pERK) proteins was studied by immunohistochemistry in samples of colonic non-neoplastic mucosa (n = 65), adenomas (n = 149) and adenocarcinomas (n = 16) from each of the 16 FAP patients.

RESULTS

For HER2, only weak cytoplasmic expression was seen in 8% of adenomas, 6% of carcinomas and 3% of the non-neoplastic mucosa. EGFR was expressed in non-neoplastic mucosa, adenomas and carcinomas with a statistically significant increase in expression in adenomas compared with non-neoplastic mucosa (p < 0.001). There was also a statistically significant increase in nuclear staining intensity for pERK (p < 0.001) and pMEK (p < 0.001) in adenomas compared to non-neoplastic mucosa.

CONCLUSIONS

This is the first study investigating the expression of these receptors in non-neoplastic mucosa, adenomas and carcinomas from FAP patients. HER2 is not upregulated in the tumours of FAP patients, while EGFR appears to be upregulated in most adenomas and carcinomas, with associated upregulation of pERK and pMEK. We conclude that EGFR and downstream members of its signalling pathway, but not HER2, may be potential therapeutic targets in FAP patients.