An Emerging Model for Cancer Development from a Tumor Microenvironment Perspective in Mice and Humans.

In the past, cancer development was studied in terms of genetic mutations acquired in cancer cells at each stage of the development. We present an emerging model for cancer development in which the tumor microenvironment (TME) plays an integral part. In this model, the tumor development is initiated by a slowly growing nearly homogeneous colony of cancer cells that can evade detection by the cell's innate mechanism of immunity such as natural killer (NK) cells (first stage; colonization). Subsequently, the colony develops into a tumor filled with lymphocytes and stromal cells, releasing pro-inflammatory cytokines, growth factors, and chemokines (second stage; lymphocyte infiltration). Cancer progression proceeds to a well-vesiculated silent tumor releasing no inflammatory signal, being nearly devoid of lymphocytes (third stage; silenced). Eventually some cancer cells within a tumor undertake epithelial-to-mesenchymal transition (EMT), which leads to cancer metastasis (fourth stage; EMT). If a circulating metastasized cancer cell finds a niche in a new tissue and evades detection by NK cells, it can establish a new colony in which very few stromal cells are present (fifth stage; metastasis), which is much like a colony at the first stage of development. At every stage, cancer cells influence their own TME, and in turn, the TME influences the cancer cells contained within, either by direct interaction between cancer cells and stromal cells or through exchange of cytokines. In this article, we examine clinical findings and animal experiments pertaining to this paradigm-shifting model and consider if, indeed, some aspects of cancer development are governed solely by the TME.

[A Survey on the Concurrent Administration of Erlotinib and Gastric Acid Suppressing Medications among Doctors:Concern for Drug Interaction].

Erlotinibis known as a key drug for the treatment of non-small-cell lung cancer. It is known to interact with gastric acid suppressing medications(AS). Concurrent administration of erlotinibwith AS is reported to decrease AUC and Cmax of erlotinib. From the result of a survey on concurrent administration of erlotinib with AS in our hospital, we considered that intake of erlotinib between meals in the morning and intake of AS after dinner or at bedtime certainly reduce the chance of drug interactions to a minimum. We suggested a direction of use of erlotinibto the doctors who used to prescribe this medication in their daily medical practice. We surveyed the doctors' perceptions of drug interactions. The results of the survey showed that 29% of the doctors were not concerned about drug interactions, although 81% of the doctors approved our proposal. By providing a suggestion for drug administration by analyzing drug information, the expectations of the doctors can be met and it also demonstrates the efficiency of pharmacists.

Targeting Mcl-1 and other Bcl-2 family member proteins in cancer therapy.

Regulation of both the extrinsic and the mitochondria-dependent intrinsic apoptotic pathways plays a key role in the development of the hematopoietic system, for sustaining cell survival during generation of various cell types, in eliminating cells with dual identities such as CD4/CD8 double-positive cells (Hettmann, Didonato, Karin, & Leiden, 1999; Ogasawara, Suda, & Nagata, 1995), for sustaining cells during the rapid clonal expansion phase (Schirmer, Vallejo, Weyand, & Gronzy, 1998), as well as eliminating cells during the contraction phase (Yajima et al., 2006). The anti-apoptotic protein Mcl-1 is necessary for sustaining hematopoietic stem cells (HPS) (Akashi et al., 2003; Akashi, Traver, Miyamoto, & Weissman, 2000). The anti-apoptotic factors Mcl-1, Bcl-2, and Bcl-xL were also found to be over-expressed in acute myeloid leukemia (AML) (Kaufmann et al., 2016) and acute lymphocytic leukemia (ALL) (Findley, Gu, Yeager, & Zhou, 1997), suggesting that dis-regulated apoptotic processes could be a factor in the instigation of leukemia and/or its relapse. Molecules targeting these proteins were used as single agents to treat leukemia. However, by using a set of recently developed specific molecule inhibitors targeting anti-apoptotic proteins, distinct roles are being discovered for these anti-apoptotic proteins during hematopoietic and tumor development. Furthermore, using these inhibitors in proper combinations can effectively induce apoptosis in various solid tumors, even though each agent on its own cannot induce apoptosis in them. These new findings suggest that inhibiting anti-apoptotic elements can induce apoptosis without external stimuli in most cells, but it comes with a risk that some combinations could also trigger apoptosis in healthy cells. One way to address the safety issue is by limiting exposure to all the agents to only cancer cells, thus making the combination safe and effective. In this article, we review this rapidly developing idea in cancer research.

Animal models for studying tumor microenvironment (TME) and resistance to lymphocytic infiltration.

In cancer immunotherapy, cytotoxic T or NK cells need to engage cancer cells to initiate the killing. However, in clinical studies and in mouse models, some solid tumors are found with no lymphocytes. It is likely that these tumors will be resistant to all sorts of immunotherapies. Thus, restoring lymphocytic infiltration will be vital to the success of immunotherapies on solid tumors. In order to understand the complex interaction between cancer cells and stromal cells, we propose to establish animal models for studying the tumor microenvironment and to develop and test therapies to restore lymphocytic infiltration of tumors Without lymphocytes infiltrating tumors, all immunotherapies on solid tumors become ineffective.

VHL-deficient renal cancer cells gain resistance to mitochondria-activating apoptosis inducers by activating AKT through the IGF1R-PI3K pathway.

We previously developed (2-deoxyglucose)-(ABT-263) combination therapy (2DG-ABT), which induces apoptosis by activating Bak in the mitochondria of highly glycolytic cells with varied genetic backgrounds. However, the rates of apoptosis induced by 2DG-ABT were lower in von Hippel-Lindau (VHL)-deficient cancer cells. The re-expression of VHL protein in these cells lowered IGF1R expression in a manner independent of oxygen concentration. Lowering IGF1R expression via small interfering RNA (siRNA) sensitized the cells to 2DG-ABT, suggesting that IGF1R interfered with the activation of apoptosis by the mitochondria. To determine which of the two pathways activated by IGF1R, the Ras-ERK pathway or the PI3K-AKT pathway, was involved in the impairment of mitochondria activation, the cells were treated with a specific inhibitor of either PI3K or ERK, and 2DG-ABT was added to activate the mitochondria. The apoptotic rates resulting from 2DG-ABT treatment were higher in the cells treated with the PI3K inhibitor, while the rates remained approximately the same in the cells treated with the ERK inhibitor. In 2DG-ABT-sensitive cells, a 4-h 2DG treatment caused the dissociation of Mcl-1 from Bak, while ABT treatment alone caused the dissociation of Bcl-xL from Bak without substantially reducing Mcl-1 levels. In 2DG-ABT-resistant cells, Mcl-1 dissociated from Bak only when AKT activity was inhibited during the 4-h 2DG treatment. Thus, in VHL-deficient cells, IGF1R activated AKT and stabilized the Bak-Mcl-1 complex, thereby conferring cell resistance to apoptosis.

Food Safety Program in Asian Countries.

By using the ILSI network in Asia, we are holding a session focused on food safety programs in several Asian areas. In view of the external environment, it is expected to impact the global food system in the near future, including the rapid increase in food demand and in public health services due to population growth, as well as the threats to biosecurity and food safety due to the rapid globalization of the food trade. Facilitating effective information sharing holds promise for the activation of the food industry. At this session, Prof. Hwang shares the current situation of Food Safety and Sanitation Regulations in Taiwan. Dr. Liu provides a talk on the role of risk assessment in food regulatory control focused on aluminum-containing food additives in China. After the JECFA evaluation of aluminum-containing food additives in 2011, each country has carried out risk assessment based on dietary intake surveys. Ms. Chan reports on the activities of a working group on Food Standards Harmonization in ASEAN. She also explains that the ILSI Southeast Asia Region has actively supported the various ASEAN Working Groups in utilizing science to harmonize food standards. Prof. Park provides current research activities in Korea focused on the effect of climate change on food safety. Climate change is generally seen as having a negative impact on food security, particularly in developing countries. We use these four presentations as a springboard to vigorous discussion on issues related to Food Safety in Asia.

Targeting cholesterol with ß-cyclodextrin sensitizes cancer cells for apoptosis.

We found that targeting cholesterol with beta-cyclodextrin (bCD) and its derivatives disrupted signal transduction between PI3K and AKT, attenuating AKT pro-survival signals. In their absence, 2-deoxyglucose (2DG) caused anti-apoptotic protein Mcll to dissociate from pro-apoptotic Bak at mitochondria. Normally Bak is sequestered by its inhibitory associations with Mcll and Bcl-xL, and only when Bak is released from both, is it free to form oligomers through which cytochrome c can escape into the cytosol. Thus an addition of a bcl-2 antagonist dissociates Bak from Bcl-xL, triggering cytochrome c release and inducing apoptosis. 2DG-bCD can also sensitize type II cancer cells for TRAIL-mediated apoptosis.

Hypothalamic 2-arachidonoylglycerol regulates multistage process of high-fat diet preferences.

BACKGROUND: In this study, we examined alterations in the hypothalamic reward system related to high-fat diet (HFD) preferences. We previously reported that hypothalamic 2-arachidonoylglycerol (2-AG) and glial fibrillary acid protein (GFAP) were increased after conditioning to the rewarding properties of a HFD. Here, we hypothesized that increased 2-AG influences the hypothalamic reward system. METHODS: The conditioned place preference test (CPP test) was used to evaluate HFD preferences. Hypothalamic 2-AG was quantified by gas chromatography-mass spectrometry. The expression of GFAP was examined by immunostaining and western blotting. RESULTS: Consumption of a HFD over either 3 or 7 days increased HFD preferences and transiently increased hypothalamic 2-AG levels. HFD consumption over 14 days similarly increased HFD preferences but elicited a long-lasting increase in hypothalamic 2-AG and GFAP levels. The cannabinoid 1 receptor antagonist O-2050 reduced preferences for HFDs after 3, 7, or 14 days of HFD consumption and reduced expression of GFAP after 14 days of HFD consumption. The astrocyte metabolic inhibitor Fluorocitrate blocked HFD preferences after 14 days of HFD consumption. CONCLUSIONS: High levels of 2-AG appear to induce HFD preferences, and activate hypothalamic astrocytes via the cannabinoid system. We propose that there may be two distinct stages in the development of HFD preferences. The induction stage involves a transient increase in 2-AG, whereas the maintenance stage involves a long lasting increase in 2-AG levels and activation of astrocytes. Accordingly, hypothalamic 2-AG may influence the development of HFD preferences.

Finding a Panacea among combination cancer therapies.

Because each cancer is a heterogeneous mix of cancer cells at different stages of development, we are faced with trying to treat many different diseased cells all at once. An authentic approach is to build a genomic and proteomic profile of a patient, identify the target oncogenes, and prescribe the combination of targeted drugs tailored for that patient. However, there are many practical problems with this personalized medicine approach: (i) cancers often generate treatment-resistant phenotypes, (ii) the treatment could be enormously expensive, and (iii) most of the targeted drugs have not been developed yet. We propose a different approach: therapies that combine 2-deoxyglucose (2DG) with Bcl-2 antagonist such as ABT-263/737 (ABT). Proapoptotic protein Bak is normally sequestered by Mcl-1 and Bcl-xL. Only when Bak is released from both Mcl-1 and Bcl-xL can it induce apoptosis. 2DG can prime highly glycolytic cells by dissociating Bak-Mcl-1 complex. Some brain cells and most cancer cells are primed by 2DG. ABT can bind to Bcl-xL, dissociating Bak-Bcl-xL complex, freeing Bak and inducing apoptosis. Because ABT cannot cross blood-brain barrier, the only cells exposed to both agents are highly glycolytic cancer cells located outside the brain. Because ABT directly triggers apoptosis at the step very near the terminal point of apoptosis, 2DG-ABT combination therapies are applicable to many types of cancer at all stages of development, with little side effect.

Efficient elimination of cancer cells by deoxyglucose-ABT-263/737 combination therapy.

As single agents, ABT-263 and ABT-737 (ABT), molecular antagonists of the Bcl-2 family, bind tightly to Bcl-2, Bcl-xL and Bcl-w, but not to Mcl-1, and induce apoptosis only in limited cell types. The compound 2-deoxyglucose (2DG), in contrast, partially blocks glycolysis, slowing cell growth but rarely causing cell death. Injected into an animal, 2DG accumulates predominantly in tumors but does not harm other tissues. However, when cells that were highly resistant to ABT were pre-treated with 2DG for 3 hours, ABT became a potent inducer of apoptosis, rapidly releasing cytochrome c from the mitochondria and activating caspases at submicromolar concentrations in a Bak/Bax-dependent manner. Bak is normally sequestered in complexes with Mcl-1 and Bcl-xL. 2DG primes cells by interfering with Bak-Mcl-1 association, making it easier for ABT to dissociate Bak from Bcl-xL, freeing Bak to induce apoptosis. A highly active glucose transporter and Bid, as an agent of the mitochondrial apoptotic signal amplification loop, are necessary for efficient apoptosis induction in this system. This combination treatment of cancer-bearing mice was very effective against tumor xenograft from hormone-independent highly metastasized chemo-resistant human prostate cancer cells, suggesting that the combination treatment may provide a safe and effective alternative to genotoxin-based cancer therapies.

Increment of hypothalamic 2-arachidonoylglycerol induces the preference for a high-fat diet via activation of cannabinoid 1 receptors.

The aim of the present study is to examine the relationship between preference for HFD and 2-arachidonoylglycerol (2-AG), endogenous cannabinoid. The 3-day HFD intake induced preference for HFD, which was suppressed by CB1 antagonist, O-2050. Moreover, hypothalamic 2-AG was increased after 3-day HFD intake. Our results show that preference for HFD is induced by activation of CB1 receptors via an increment of 2-AG in hypothalamus.

Reducing acyl migration during purification of 2-arachidonoylglycerol from biological samples before gas chromatography mass spectrometry analysis.

Endocannabinoid 2-arachidonoylglycerol (2-AG) regulates several important physiological processes in the brain. 2-AG is commonly quantified by gas chromatography mass spectrometry after an initial purification step. The most precise and rapid purification utilizes C(18) solid-phase extraction, but quantification problems can arise with acyl migration from 2-AG to 1-arachidonoylglycerol. We found that extraction with methanol promoted this migration, but acetone and diethyl ether (Et(2)O) did not. Acetone and Et(2)O were used to develop a purification method for the direct determination of 2-AG.

Dynamics of mitochondrial structure during apoptosis and the enigma of Opa1.

"The large scale remodeling of mitochondria during apoptosis is a necessary step for the complete release of cytochrome c" has been a tenet since 2002. However, more recent findings strongly indicate that the large-scale remodeling previously described actually takes place after the release of cytochrome c and in a caspase-dependent manner, bringing into question whether mitochondria remodeling is necessary. In a more recent article, however, it was shown that a much more subtle form of remodeling is taking place which is only observable by electron tomography. In the Bcl-2 inhibitable Bax/Bak-dependent intrinsic pathway of apoptosis, the release of cytochrome c from mitochondria is a consequence of two carefully coordinated events: formation of outer membrane pores and opening of crista junctions triggered by Opa1 oligomer disassembly, and both steps are necessary for the complete release of cytochrome c. We review the recent literature pertaining to the coordinated release of cytochrome c during cell death.

Opa1-mediated cristae opening is Bax/Bak and BH3 dependent, required for apoptosis, and independent of Bak oligomerization.

Controversy surrounds the role and mechanism of mitochondrial cristae remodeling in apoptosis. Here we show that the proapoptotic BH3-only proteins Bid and Bim induced full cytochrome c release but only a subtle alteration of crista junctions, which involved the disassembly of Opa1 complexes. Both mitochondrial outer membrane permeabilization (MOMP) and crista junction opening (CJO) were caspase independent and required a functional BH3 domain and Bax/Bak. However, MOMP and CJO were experimentally separable. Pharmacological blockade of MOMP did not prevent Opa1 disassembly and CJO; moreover, expression of a disassembly-resistant mutant Opa1 (Q297V) blocked cytochrome c release and apoptosis but not Bax activation. Thus, apoptosis requires a subtle form of Opa1-dependent crista remodeling that is induced by BH3-only proteins and Bax/Bak but independent of MOMP.

Clinical evaluation of a new bleaching product "Polanight" in a Japanese population.

Home bleaching techniques have been applied as a safe and effective bleaching procedure. Many manufacturers are now marketing home tooth-bleaching products. The purpose of this study was to compare a new bleaching product, Polanight (PN) with a widely used home bleaching product, Opalescence (OP). Fifty-eight healthy Japanese volunteers of both sexes (18 to 47 years of age) were selected. Using a simultaneous split-mouth protocol, custom-made trays with PN and OP were applied to the maxillary right anterior teeth and left anterior teeth, respectively. The shades of the maxillary canine teeth were measured with a portable chromameter (Shade Eye Ex) at the first examination and at 4 weeks (after 2-week bleaching and 2-week rest). Tooth shade changes were analyzed using the Commission Internationale d'Eclairage (CIE) Lab units. Means of whiteness-blackness difference (DeltaL*), redness-greenness difference (Deltaa*), and yellowness-blueness difference (Deltab*) were 4.00, -1.28 and -7.53 for PN, and 2.54, -0.99, and -5.56 for OP, respectively. Means of color difference (DeltaE*) were 9.23 and 7.78 for PN and OP, respectively. Treatment with either agent demonstrated significant bleaching effects produced by the treatment. The new product, PN, showed significant differences in DeltaL* (P < 0.05) and Deltab* (P < 0.005), but not in the redness-greenness (a*) value when compared with OP. Bleaching with PN was considered more effective than that with OP in the young patient group and in the women.

A role for Ran-GTP and Crm1 in blocking re-replication.

All eukaryotic cells have regulatory mechanisms that limit genomic replication to a single round each cell cycle. These systems function by blocking formation of prereplication complexes. The regulatory mechanisms in the yeast S. cerevisiae have been identified, but these do not appear to be conserved in metazoans. Using Xenopus egg extracts, we have identified a metazoan-specific regulatory system that limits replication to a single round. We show that during S phase, soluble MCM helicase, an essential initiation factor, is inactivated when it associates with exportin-1/Crm1. Formation of this complex is dependent on both high Ran-GTP and cdk2 kinase activity. Lowering Ran-GTP within nuclei or nuclear extracts allows MCM to reassociate with chromatin during S phase and induces re-replication. Importantly, prevention of re-replication requires MCM-Crm1 complex formation, but it does not require export of MCM from the nucleus. Therefore, in metazoans, Crm1 functions in both nuclear export and blocking of re-replication.