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PDF file - 114K, Chemical structures of investigated molecules in this article

PDF file - 135K, Treatment of saracatinib in LS174T and SKBR3 cells

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PDF file - 173K, Induction of Bim by saracatinib treatment

A PARP inhibitor is a rationally designed targeted therapy for cancers with impaired DNA repair abilities. RAD51C is a paralog of RAD51 that has an important role in the DNA damage response. We found that cell lines sensitive to a novel oral PARP inhibitor, olaparib, had low levels of RAD51C expression using microarray analysis, and we therefore hypothesized that low expression of RAD51C may hamper the DNA repair process, resulting in increased sensitivity to olaparib. Compared with the cells with normal RAD51C expression levels, RAD51C-deficient cancer cells were more sensitive to olaparib, and a higher proportion underwent cell death by inducing G2–M cell-cycle arrest and apoptosis. The restoration of RAD51C in a sensitive cell line caused attenuation of olaparib sensitivity. In contrast, silencing of RAD51C in a resistant cell line enhanced the sensitivity to olaparib, and the number of RAD51 foci decreased with ablated RAD51C expression. We also found the expression of RAD51C was downregulated in cancer cells due to epigenetic changes and RAD51C expression was low in some gastric cancer tissues. Furthermore, olaparib significantly suppressed RAD51C-deficient tumor growth in a xenograft model. In summary, RAD51C-deficient cancer cells are highly sensitive to olaparib and offer preclinical proof-of-principle that RAD51C deficiency may be considered a biomarker for predicting the antitumor effects of olaparib. Mol Cancer Ther; 12(6); 865–77. ©2013 AACR.

PDF file - 96K, Downregulation of thymidylate synthase (TS) by saracatinib

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PDF file - 3250K, Figure S1 Olaparib has variable levels of anti-tumor activity in human cancer cell lines. Figure S2 Olaparib sensitive cell lines have different patterns of gene expression compared to insensitive cell lines. Figure S3 PTEN expression does not affect olaparib sensitivity. Figure S4 RAD51C expression affects olaparib sensitivity in human cancer cell lines. Figure S5 RAD51C over-expression decreases sensitivity to olaparib in the BT-549 cell line. Figure S6 Olaparib induces G2/M cell cycle arrest and apoptosis in sensitive cell lines. Figure S7 RAD51C depletion increases the accumulation of DNA damage. Figure S8 RAD51C expression decreases in tumor tissues. Figure S9 RAD51C expression is down-regulated in gastric tumor tissues via DNA methylation. Table S1. Sequences of the primers for PCR and real-time PCR analyses. Table S2. BRCA1 and BRCA2 mutations in the gastric cancer cell lines.

PDF file - 215K, mRNA and protein expression level of integrin �8 in gastric cancer cell lines

Recently, flexible electronic device technology has evolved beyond curved devices with the development of flexible/stretchable devices that can be crumpled or stretched. Both elasticity and durability are essential for these devices, which should have high-conductivity for antennas and repeatability for sensors. In addition, electronic-skins, which can have a direct impact on the human-body, should be harmless to the human-body and should not be deformed by contact with sweat or organic matter. In this study, PDMS substrates were used to satisfy the above conditions. PDMS is used to fabricate human-friendly, flexible/stretchable substrates, and it has excellent repeat durability characteristics. To improve the adhesion of these PDMS films and electrodes, conductive paste was produced based on PDMS resins of the same properties. In addition, two types of Ag particles were selected as conductive fillers because the electrode characteristics of the antenna application requires excellent conductivity, and conductive paste were produced using flake Ag, which could affect conductivity, and Ag nanoparticles that affect stretchability and repeatability. The paste was applied using a high-efficiency printing technique. The printed electrodes were cured in a thermal oven. For higher conductivity, photonic-sintering was carried out during post-processing. As a result, 1.1117×106 (S/m) had excellent conductivity, performed well in repeated tensile-durability experiments of 30% to 100 times, and produced a bow-tie antenna for the above electrodes. As a result of tensing up to 35% through a Network-Analyzer, there was no performance change in the resonance-frequency or return-loss values, and excellent electrodes were developed that would achieve excellent performance even if they are applied in the sub-frequency area of 5G-antennas in the future.

This study explored the feasibility of a fast and uniform large-scale laser sintering method for sintering stretchable electrodes. A homogenized rectangular infrared (IR) laser with a wavelength of 980 nm was used in the sintering process. A highly stretchable composite electrode was fabricated using silver (Ag) microparticles and Ag flakes as the fillers and polyester resin as the binder on the polyurethane substrate. This laser-sintering method showed a sintering time of 1 sec and a very uniform temperature across the surface, resulting in enhancing the conductivity and stretchability of the electrodes. The effects of the laser power on the electrical and electromechanical properties of the electrodes were investigated. Using stretching, bending, and twisting tests, the feasibility of the laser-sintered stretchable electrodes was comprehensively examined. The electrode that was sintered at a laser power of 50 W exhibited superior stretchability at a strain of 210%, high mechanical endurance of 1,000 repeated cycles, and excellent adhesion. The stretchable electrodes showed excellent bendability and twistability in which the electrodes can be bent up to 1 mm and twisted up to 90° without any damage; thus, they are highly applicable as stretchable electrodes for wearable electronics. Additionally, the Ag composites were explored for use in a radio-frequency (RF) stretchable antenna to confirm the application of the laser-sintering method for stretchable and wearable electronic devices. The stretchable dipole antenna showed an excellent radiation efficiency of 95% and a highly stable operation, even when stretched to 90% strain.

Stretchable electronic devices commonly require interconnectors with high stretchability, conductivity, and durability. In this work, we demonstrated a highly stretchable electrode based on a composite of silver (Ag) flake filler and Ecoflex binder. The stretchable composite material was printed on polyurethane substrate. To improve the dispersibility and printability of the composite material, poly(dimethylsiloxane-ethylene oxide polymeric) was used. The effects of Ag flake content and Ecoflex binder materials on the electromechanical properties of the stretchable electrode were investigated via stretching and cyclic stretching tests. As the amount of Ag flake increased, the electrical conductivity of the electrode increased as well, but the stretchability decreased. Use of Ecoflex 00-10 material, with its softer and lower Young's modulus, greatly improved the stretchability of the electrode—allowing it to stretch to a strain of up to 120%. The stretchable electrode withstood repetitive cyclic stretching durability tests of 10,000 cycles. The addition of carbon black also had a great impact on its electromechanical properties. An electrode fabricated with 0.2 wt% carbon black showed the highest conductivity and excellent stretchability of more than 150%.

In stretchable conductors, there is a trade-off relationship between the stretchability and conductivity which makes it difficult to increase both properties simultaneously. From a practical point of view, however, high conductivity is a more important parameter for real-world applications of wearable and mobile electronics. To obtain a highly conductive stretchable conductor, we developed a stretchable conductor composed of silver (Ag) flat-type microparticles, Ag nanoparticles and a polyester binder. The printed stretchable conductor was then sintered using the intense pulse light sintering technique. The effects of different mixing ratios of Ag flat-type particles and nanoparticles on dispersibility, printability, surface properties, conductivity, and stretchability were examined. Increasing the content of Ag-flat type particles in the composite improved dispersibility, printability, and conductivity. The stretchable conductor exhibited the outstanding conductivity of 5.5×106 S/m. Increasing the Ag nanoparticles content increased the stretchability of the conductor. As the nanoparticle content increased to 30%, the stretchable conductor showed the excellent stretchability of 210%, and withstood 2,600 repeated stretching cycles at a fixed tensile strain of 50%. The conductors also exhibited superb foldability during 10,000 repeated folding tests, up to a radius of 1 mm, without any failures.

The optimal drying conditions for fresh green hot peppers (Capsicum annuum. L) were investigated through hypobaric drying (HB) and hot-air drying (HA). HB was performed at temperature at 35°C, 40°C, 45°C and 45°C after 80% dried at 40°C and HA was performed at 40°C, 50°C, 60°C and 50°C after 80% dried at 50°C. HB offered a lower drying temperature and reduced drying time. The quality of the vivid green color of the dried power was superior for peppers dried at 35 and 40°C through HB and at 40°C and 50°C via HA to others. Considering the drying time, 40°C HB (42 h) and 50°C HA (23 h) were ideal compared to the other six treatments. Through both drying methods, the flesh and seeds of the peppers exhibited more significant brown discoloration with increasing temperature. Epidermis whitening, which is the discoloration of green hot peppers during drying, occurred at a higher rate at lower temperatures, resulting in a lighter green pepper powder through 35°C HB and 40°C HA. The water absorption index increased as the temperature lowered, but the water solubility index did not change. The capsiacinoids concentration did not vary between the powders undergoing 40°C HB and 50°C HA; however, the vitamin C concentration was higher in the powder subjected to 40°C HB.

In recent years, there has been a lot of research on printed paste and ink composite electrode material made with metallic-based materials such as silver nanowires, silver nanoparticles, and flakes with epoxy-based binders. These stretchable electrode materials must exhibit metal-level conductivity and high interfacial adhesion that can withstand necking and deformation stress. To overcome several issues including the low adhesion properties found in silicone-based binders and the low heat resistance found in urethane-based binders, we synthesized a binder material with over 300% stretchability and high adhesive strength. This was done by modifying an epoxy to produce a binder that can be easily applied to various materials without special surface treatment technologies. In addition, we developed a printable, stretchable electrode material with high adhesive strength, high conductivity, and high stretchability by mixing three types of silver powders (flake, spherical micro-particle, and nanoparticle) with the modified epoxy binder. Results from electrode conductivity, stretchability, repetitive fatigue property, and residual strain analyses demonstrate that these properties are highly dependent on nanoparticle content and distribution. The electrode resistivities ranged from 8.5 × 10−5 to 2.5 × 10−5 Ω cm after heat curing at 170 °C and showed excellent stability at strain of over 140%.

In stretchable strain sensors, highly elastic elastomers such as polydimethylsiloxane (PDMS), Ecoflex, and polyurethane are commonly used for binder materials of the nanocomposite and substrates. However, the viscoelastic nature of the elastomers and the interfacial action between nanofillers and binders influence the critical sensor performances, such as repeatability, response, and hysteresis behavior. In this study, we developed a stretchable nanocomposite strain sensor composed of multiwalled carbon nanotubes and a silicone elastomer binder. The effects of binder and substrate materials on the repeatability, response, hysteresis behavior, and long-term endurance of the strain sensors were systematically investigated using stretching, bending, and repeated cyclic bending tests. Three different binder and substrate materials including PDMS, Ecoflex, and a mixture of PDMS/Ecoflex were tested. The stretchable strain sensors showed an excellent linearity and stretchability of more than 130%. Therefore, the long-term endurance of the strain sensors fabricated with Ecoflex binder should be improved. The strain sensors fabricated with Ecoflex binder showed a relatively large variation in electrical resistance during 10,000-cycle bending tests and repeatability errors at large bending angles. The strain sensors fabricated with PDMS binder showed repeatability errors at small bending angles and a slight response delay of 1 second. On the contrary, the strain sensors fabricated with a mixture of PDMS/Ecoflex binder showed excellent repeatability and response characteristics. The PDMS material showed hysteresis behavior; therefore, the strain sensors fabricated with PDMS binder on PDMS substrate exhibited a large hysteresis behavior in the first stretch–release cycle. It was found that the hysteresis behavior of the strain sensors was mainly dependent on substrate materials than on binder materials. The stretchable strain sensors made of the mixture of PDMS/Ecoflex exhibited excellent repeatability, response, hysteresis behavior, and excellent capability in detecting finger and wrist bending.

We present a highly stretchable and compact bow-tie antenna which operates at 5 GHz for wearable applications. The dimensions of the bow-tie antenna were 7.9 mm×17.8 mm. The stretchable antenna was fabricated with a composite mixture of silver flake and polymer binder. The composite paste was printed on polyurethane and textile using the screen printing technique. The RF performances, stretchability, bendability, and durability of the antennas were evaluated, which are critical requirements in wearable electronics. The stretchable bow-tie antennas showed excellent RF performances and stretchability up to a stretching strain of 40%. The antennas could be bent up to a bending radius of 20 mm without degrading RF performance. The stretchable antennas also exhibited outstanding mechanical endurance after 10,000 cyclic stretching tests. The antennas were not affected by the presence of the body and showed very stable RF performances, exhibiting promising results for mobile and wearable applications.

In textile and wearable electronics, the demand for a stretchable, durable, and easily manufacturable electrode is ever increasing. This paper describes the development of a highly stretchable and durable textile electrode fabricated by simple stencil and screen printing methods. It specifically investigated the effects of an interface layer as a planarization layer between the conductive electrode and the textile on the durability of the textile electrode. A stretchable conductive paste was synthesized by mixing Ag flake powder in polyester. The conductive electrode was encapsulated with Ecoflex material. The stretchability and durability of the textile electrodes were evaluated via stretching, bending, Massachusetts Institute of Technology (MIT) folding, twisting, and dynamic endurance tests. The stretching and MIT folding tests indicated that the interface layer significantly enhanced the durability of the textile electrode. A highly stretchable and flexible textile electrode exhibited a low sheet resistance of 0.05 Ω/square, excellent stretchability of 70%, and a critical bending radius of 1.5 mm. The textile electrodes also withstood dynamic stretching and bending endurance tests of 10,000 cycles. The illumination of a light-emitting diode with the conductive electrode was also stable under 70% tensile strain and in water. The potential application of the textile electrode as a strain sensor was demonstrated by applying it to a glove to detect finger motion. The strain sensors responded well to the finger motion, with considerable stability and repeatability.

Asivatrep is a potent and selective antagonist of transient receptor potential vanilloid subfamily V member 1 (TRPV1), which plays an important role in itch and inflammation in atopic dermatitis (AD).This current study aimed to evaluate the efficacy and safety of asivatrep cream in patients with AD.For this phase 3 double-blind, vehicle-controlled study, patients aged ≥12 years with mild to moderate AD were enrolled and randomly assigned 2:1 to the 1.0% asivatrep or vehicle group for 8 weeks of twice-daily application (n = 240). The primary end point was the proportion of patients with an Investigator's Global Assessment score (IGA) of 0 or 1 at week 8. Standard safety assessments were conducted.At week 8, significantly more patients in the asivatrep group (36.0%) than in the vehicle group (12.8%) had IGA scores of 0 or 1 (P .001); significantly more had ≥2 points of improvement on the IGA from baseline score (20.3% vs 7.7%; P = .01). The mean percentage reduction in the Eczema Area and Severity Index (EASI) score was 44.3% for the asivatrep group and 21.4% for the vehicle group at week 8 (P .001). Significantly more asivatrep-treated patients experienced an improvement of at least 50%, 75%, and 90% on the EASI than the vehicle group. The mean ± SD change in the pruritus visual analog scale score at week 8 was -2.3 ± 2.4 for the asivatrep group and -1.5 ± 2.4 for the vehicle group (P = .02). No significant safety issues were reported.Asivatrep improved clinical signs and symptoms of AD and was well tolerated.

We investigated the effect of PE film thickness on the modified atmosphere packaging (MAP) deastringency of ‘Sanggamdungsi’ (Diospyros kaki cv.) astringent persimmon at room temperature (25°C) and low temperature (-1°C). The fruits were individually packaged with PE film of which the thickness is 60, 80, 100, 115 or 130 μm and stored at room or low (-1°C) temperature. At room temperature, firmness shows the highest value (23.3-26.5) at 100 μm thickness. Top flesh browning and decay was monitored at 20 days after storage, and peel blackening and style-end softening was negligible at optimal thickness. Therefore, optimal film thickness of deastringency at room temperature is 80-100 μm. At this thickness, the astringency was removed after 5 days and the fruits can be distributed until 10 days after the MAP. At low (-1°C) temperature, firmness was maintained regardless of film thickness. However, the firmness is higher as the film is thicker. Top flesh browning and decay was not occurred even after 90 days after storage. Peel blackening and style-end softening was monitored at 90 days after storage. Off-flavor was monitored at 115 and 130 μm thickness. Therefore, optimal film thickness of deastringency at low (-1°C) temperature is 80-100 μm. At this thickness, the astringency was removed after 50 days and the fruits can be distributed until 80 days after the MAP.

Purpose KX-01 is a novel dual inhibitor of Src and tubulin. Unlike previous Src inhibitors that failed to show clinical benefit during treatment of breast cancer, KX-01 can potentially overcome the therapeutic limitations of current Src inhibitors through inhibition of both Src and tubulin. The present study further evaluates the activity and mechanism of KX-01 in vitro and in vivo. Materials and methods The antitumor effect of KX-01 in triple negative breast cancer (TNBC) cell lines was determined by MTT assay. Wound healing and immunofluorescence assays were performed to evaluate the action mechanisms of KX-01. Changes in the cell cycle and molecular changes induced by KX-01 were also evaluated. A MDA-MB-231 mouse xenograft model was used to demonstrate the in vivo effects. Results KX-01 effectively inhibited the growth of breast cancer cell lines. The expression of phospho-Src and proliferative-signaling molecules were down-regulated in KX-01-sensitive TNBC cell lines. In addition, migration inhibition was observed by wound healing assay. KX-01-induced G2/M cell cycle arrest and increased the aneuploid cell population in KX-01-sensitive cell lines. Multi-nucleated cells were significantly increased after KX-01 treatment. Furthermore, KX-01 effectively delayed tumor growth in a MDA-MB-231 mouse xenograft model. Conclusion KX-01 effectively inhibited cell growth and migration of TNBC cells. Moreover, this study demonstrated that KX-01 showed antitumor effects through the inhibition of Src signaling and the induction of mitotic catastrophe. The antitumor effects of KX-01 were also demonstrated in vivo using a mouse xenograft model.

In recent flip chip technology, Copper (Cu) pillar bump has replaced the conventional solder ball because of its higher input/output density, higher reliability, finer pitch. However, as size of Cu pillar bump and pitch decreasing, Cu pillar bump technology face some problems such as interconnect shorting, higher low-k stress when the conventional mass reflow process is used. To solve this problem, several new bonding processes has been developed such as the thermal compression bonding (TCB) and laser assisted bonding, New bonding processes has been developed to meet the requirements of fine pitch and higher reliability of Cu pillar bump technology. During TCB process or laser assisted bonding process, the substrate has a lower temperature than the chip, which reduces the coefficient of thermal expansion (CTE) mismatch-induced stresses and package warpage. In this study, the absorptivity, reflectivity and transmittivity of Si chips were measured by using spectrometer and halogen lamp. The obtained absorptivity was applied to numerical analysis to optimize laser assisted bonding conditions. We performed laser reflow and laser thermal compression bonding warpage simulation using finite element analysis. Similar warpage results were obtained compared with the real samples and the validity of the numerical analysis was verified.

This paper describes the development of a highly stretchable and durable textile electrode fabricated by simple stencil and screen printing methods. It specifically investigated the effects of an interface layer as a planarization layer between the conductive electrode and the textile on the durability of the textile electrode. A stretchable conductive paste was synthesized by mixing Ag flake powder in a polyester. The conductive electrode was encapsulated with Ecoflex material. The stretchability and durability of the textile electrodes were evaluated via stretching, MIT folding, and dynamic endurance tests. The stretching and MIT folding tests indicated that the interface layer significantly enhanced the durability of the textile electrode. A highly stretchable and flexible textile electrode exhibited a low sheet resistance of $0.05 \Omega /$square, excellent stretchability of 70%. The textile electrodes also withstood stretching endurance tests of 10,000 cycles. The illumination of an LED with the conductive electrode was also stable under 70% tensile strain and in water.

This study proposes a highly stretchable, conductive electrode based on micro-sized Ag particles and Ag flakes incorporated into a polyester binder. The use of the microparticles in fabricating the stretchable electrode has several advantages over the spherical nanoparticles, namely, affordable, easier to synthesize, slower oxidation, and higher aspect ratio. Intense pulsed light (IPL) was employed to sinter the stretchable composite electrode printed on a polyurethane substrate. IPL was found to be an effective and fast sintering technique that lasts within seconds for stretchable electrodes consisting of Ag microparticles. The electrical and electromechanical properties were examined with varying the IPL energy intensities. The optimum IPL energy intensity was found to be 2 J/cm2 without damaging the substrate. The stretchable electrodes exhibited superior stretchability of 170% strain and high mechanical stability of over 1000 stretching cycles under 50% strain. The stretchable electrodes exhibited excellent bendability, as they could be bent up to 1 mm and withstand 1000 repetitive bending cycles at a bending radius of 2 mm. The electrodes also showed a robust static bending endurance during the 240 h test and excellent adhesion strength. The electromechanical properties of the stretchable electrode could be further enhanced by minimizing the pores and voids inside the electrode during the synthesis and sintering process.

We investigated the mechanisms of action and antitumor effects of OPB-31121, a novel STAT3 inhibitor, in gastric cancer cells. OPB-31121 downregulated JAK2 and gp130 expression and inhibited JAK2 phosphorylation which leads to inhibition of STAT3 phosphorylation. OPB-31121 inhibited constitutively activated and IL-6-induced JAK/STAT signaling pathway. OPB-31121 decreased cell proliferation in both gastric cancer cells and in a xenograft model, induced the apoptosis of gastric cancer cells, inhibited the expression of antiapoptotic proteins, and showed synergism with 5-fluorouracil and cisplatin. Taken together, our study suggests that STAT3 inhibition with OPB-31121 can be tested in patients with gastric cancer.

A PARP inhibitor is a rationally designed targeted therapy for cancers with impaired DNA repair abilities. RAD51C is a paralog of RAD51 that has an important role in the DNA damage response. We found that cell lines sensitive to a novel oral PARP inhibitor, olaparib, had low levels of RAD51C expression using microarray analysis, and we therefore hypothesized that low expression of RAD51C may hamper the DNA repair process, resulting in increased sensitivity to olaparib. Compared with the cells with normal RAD51C expression levels, RAD51C-deficient cancer cells were more sensitive to olaparib, and a higher proportion underwent cell death by inducing G2–M cell-cycle arrest and apoptosis. The restoration of RAD51C in a sensitive cell line caused attenuation of olaparib sensitivity. In contrast, silencing of RAD51C in a resistant cell line enhanced the sensitivity to olaparib, and the number of RAD51 foci decreased with ablated RAD51C expression. We also found the expression of RAD51C was downregulated in cancer cells due to epigenetic changes and RAD51C expression was low in some gastric cancer tissues. Furthermore, olaparib significantly suppressed RAD51C-deficient tumor growth in a xenograft model. In summary, RAD51C-deficient cancer cells are highly sensitive to olaparib and offer preclinical proof-of-principle that RAD51C deficiency may be considered a biomarker for predicting the antitumor effects of olaparib. Mol Cancer Ther; 12(6); 865–77. ©2013 AACR.

Src is a nonreceptor tyrosine kinase involved in the cross-talk and mediation of many signaling pathways that promote cell proliferation, adhesion, invasion, migration, and tumorigenesis. Increased Src activity has been reported in many types of human cancer, including gastric cancer. Therefore, this factor has been identified as a promising therapeutic target for cancer treatments, and targeting Src in gastric cancer is predicted to have potent effects. We evaluated the antitumor effect of a c-Src/Abl kinase inhibitor, saracatinib (AZD0530), alone or combined with chemotherapeutic agents in gastric cancer cell lines and a NCI-N87 xenograft model. Among 10 gastric cancer cell lines, saracatinib specifically inhibited the growth and migration/invasion of SNU216 and NCI-N87 cells. Saracatinib blocked the Src/FAK, HER family, and oncogenic signaling pathways, and it induced G1 arrest and apoptosis in SNU216 and NCI-N87 cells. Apoptosis required induction of the proapoptotic BCL2 family member Bim. Knockdown of Bim using siRNA decreased apoptosis induced by treatment with saracatinib, suggesting that Bim has an important role in saracatinib-induced apoptosis. Saracatinib enhanced the effects of lapatinib, an EGFR/HER2 dual inhibitor, in SNU216 and NCI-N87 cells. Furthermore, combined treatment with saracatinib and 5-fluorouracil (5-FU) or cisplatin exerted synergistic effects in both saracatinib-sensitive and saracatinib-resistant cells. Consistent with our in vitro findings, cotreatment with saracatinib and 5-FU resulted in enhanced antitumor activity in the NCI-N87 xenografts. These data indicate that the inhibition of Src kinase activity by saracatinib alone or in combination with other agents can be a strategy to target gastric cancer. Mol Cancer Ther; 12(1); 16–26. ©2013 AACR.

Recently, HER2-directed treatment, such as trastuzumab, has shown clinical benefit in HER2-amplified gastric cancer. On the basis of recent studies about epidermal growth factor receptor (EGFR) or HER2-targeting agents (including gefitinib, lapatinib, and trastuzumab) in gastric cancer, the potent effects of pan-HER inhibitors targeting the HER family are anticipated. In this study, we evaluated the activity and mechanisms of PF00299804, an irreversible pan-HER inhibitor, in gastric cancer in vitro and in vivo models. PF00299804 showed significant growth-inhibitory effects in HER2-amplified gastric cancer cells (SNU216, N87), and it had lower 50% inhibitory concentration values compared with other EGFR tyrosine kinase inhibitors, including gefitinib, lapatinib, BIBW-2992, and CI-1033. PF00299804 induced apoptosis and G1 arrest and inhibited phosphorylation of receptors in the HER family and downstream signaling pathways including STAT3, AKT, and extracellular signal–regulated kinases (ERK) in HER2-amplified gastric cancer cells. PF00299804 also blocked EGFR/HER2, HER2/HER3, and HER3/HER4 heterodimer formation as well as the association of HER3 with p85α in SNU216 cells. The combination of PF00299804 with clinically relevant chemotherapeutic agents or molecular-targeted agents including trastuzumab (an anti-HER2 monoclonal antibody), CP751871 (an IGF1R inhibitor), PD0325901 (an ERK1/2 inhibitor), and PF04691502 (a PI3K/mTOR inhibitor) produced synergistic effects. These findings indicate that PF00299804 can be used as a targeted therapy for the treatment of HER2-amplified gastric cancer through inhibition of HER family heterodimer formation and may augment antitumor efficacy of chemotherapeutic and/or molecular-targeted agents. Mol Cancer Ther; 11(2); 439–51. ©2011 AACR.

The ultra high performance liquid chromatography (u-HPLC) method for determination of β-carotene in foods was validated in terms of precision, accuracy, and linearity. The u-HPLC separation was performed on a reversed column C18 (particle size 2 μm, i.d. 2 mm, length 50 mm), followed by ultra violet (UV) detection at 450 nm. The recovery of β-carotene was more than 84.4% and the limit of detection and limit of quantitation of u-HPLC analysis were 0.28 and 0.85 μg/mL for β-carotene with butylated hydroxytoluene (BHT) and 0.62 and 1.89 μg/mL for β-carotene without BHT, respectively. The calibration graph for β-carotene was linear from 0.1 to 25.0 μg/mL for u-HPLC. The intra- and interday precisions (relative standard deviations) were

Human epidermal growth factor receptor 2 (HER2) heterodimerizes and shares common signaling pathways with epidermal growth factor receptor (EGFR). In this study, we investigated the clinical implication of amphiregulin, a ligand for EGFR, on trastuzumab therapy in HER2-positive breast cancer. Serum amphiregulin levels were quantified in 50 consecutive patients with HER2-positive metastatic breast cancer who received first-line trastuzumab plus taxane chemotherapy between October 2004 and July 2009. In addition, in vitro experiments were carried out to validate the results. The median serum amphiregulin level was 1.0 ng/mL with a maximum level of 4.4 ng/mL. Patients with high serum amphiregulin levels (≥0.5 ng/mL) had significantly shorter progression-free survival (15.1 months vs. not reached; P = 0.018). Colony-forming assays demonstrated that the addition of amphiregulin resulted in increased proliferation of cells. In addition, the anti-proliferative effect of trastuzumab was decreased in the presence of amphiregulin. Western blot analysis showed that amphiregulin activated AKT and ERK pathways. In addition, in the presence of amphiregulin, sustained phosphorylation of AKT and ERK pathways was observed after trastuzumab treatment. High serum amphiregulin levels were associated with early disease progression in these patients, possibly due to AKT and ERK signaling activation by amphiregulin.

Trastuzumab, a HER2 directed treatment has shown clinical benefit in HER2 amplified gastric cancer. This study demonstrated the potent antitumor activity of HM781-36B, a quinazoline-based irreversible pan-HER inhibitor, in HER2 amplified gastric cancer cells (SNU216 and N87) in vitro and in vivo. HM781-36B inhibited phosphorylation of HER family and downstream signaling molecules, and induced apoptosis and G1 arrest. Furthermore, HM781-36B exerted synergistic effects with chemotherapeutic agents in both HER2 amplified and HER2 non-amplified gastric cancer cells. Therefore, HM781-36B may be useful for the treatment of HER2 amplified gastric cancer alone or in combination with chemotherapeutic agents.

Background: Src is a nonreceptor tyrosine kinase involved in the crosstalk and mediation of many signaling pathways that promote cell proliferation, invasion and angiogenesis. Elevation of Src activity has been reported in many types of cancers including gastric cancer (GC) and biliary tract cancer (BTC). The purpose of this study is to evaluate Src as a therapeutic target and to elaborate the biomarkers of Src inhibitor in GC and BTC. Methods: Ten gastric cancer cell lines (SNU-1, 5, 16, 216, 601, 620, 638, 668, 719, NCI-N87) and 8 biliary tract cancer cell lines (SNU-245, 308, 478, 869, 1079, 1196, HuCCT1, TFK1) were used. Saracatinib and bosutinib were used as Src inhibitors. MTT assay, colony formation assay and 3D culture were done for determining growth inhibitory effect of Src inhibitors, alone or in combination with chemotherapeutic agents (5-FU, gemcitabine, cisplatin). Cell cycle analysis was done by FACS Calibur flow cytometer. Matrigel invasion assay and wound healing assay were done. The methods described by Chou and Talalay were used to determine whether a synergistic effect existed between drug combination. Tumor xenograft model was made and used for in vivo test of Src inhibitors. Results: Among 10 GC cells, SNU216 and NCI-N87 were sensitive to Src inhibitor. These sensitive cells showed high levels of pSRC(Y416) and pFAK (Y861, Y397, Y925). These 2 sensitive GC cells are both HER2 amplified cells. However, HER2-positive breast cancer (BC) cells (SKBR3, BT474, MDA-MB453) were resistant to Src inhibitor. Contrast to these resistant BC cells, SNU216 and N87 showed high expression of integrin αV, β4 and β8. Especially, in case of integrin β8, the mRNA/protein levels were highest in SNU216 and N87 among all GC cells. Src inhibitor-sensitive GC cells showed the apoptosis by Src inhibitor and synergism with 5-FU in vitro and in vivo. Among 8 BTC cells, 3 cells were sensitive to Src inhibitor (SNU308, SNU478 and HuCCT1) in terms of growth inhibition and migration/invasion inhibition. Sensitive cells showed high levels of integrin α2, α3 and β4. Src inhibitor induced G1 arrest and decreased pSrc, pFAK, and pERK in sensitive cells. Inhibition of pSrc was accompanied with increase of PTEN and decrease of pAKT. Src inhibitor showed the synergistic effects with cytotoxic chemotherapeutic agents (gemcitabine and cisplatin) in vitro and in vivo. When the Src was inhibited, pSTAT3 was increased thru increase of IL-6 in some cells. Conclusion: Taken together, Src could be a potential therapeutic target in gastric cancer and biliary tract cancer. The role of integrin as a biomarker for Src inhibitor should be further investigated. Citation Format: Ah-Rong Nam, Hyun-Jin Nam, Kyo Hwa Kang, Ji Eun Park, Tae Yong Kim, Sae-Won Han, Sang-Hyun Song, Seock-Ah Im, Tae-You Kim, Do-Youn Oh, Yung-Jue Bang. Evaluation of Src as a therapeutic target and development of biomarkers of Src inhibitor in cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 747. doi:10.1158/1538-7445.AM2014-747

2565 Background: HM781-36B, a novel pan-HER tyrosine kinase inhibitor, showed potent in vitro and in vivo antitumor activities for EGFR mutant models including T790M mutation. In the previous 2-weeks on, 1-week off phase I study, the maximum tolerated dose (MTD) was determined as 24 mg/day. Phase I study with a continuous daily dosing schedule was conducted to determine the recommended dose (RD), and to assess the effect of food on pharmacokinetics (PK) in patients (pts) with advanced solid tumors. Methods: Eligible pts had advanced malignancies refractory to standard therapies. Standard 3+3 scheme was used in the dose escalation study, and additional 8 patients were enrolled to test food effects. Results: 20 pts (median age: 55 years [range32-77], M:F=13:7, ECOG PS 0/1/2/3 8/12/0/0) were enrolled (5 NSCLC, 4 colon cancer, 3 stomach cancer, 2 breast cancer, 2 rectal cancer, 2 common bile duct cancer, 1 pancreatic cancer and 1 esophageal cancer); 12 in the dose escalation and 8 in the food effect study cohort. Twelve pts were heavily pretreated(≥4 regimens). Dose limiting toxicities (DLTs) were G3 anorexia in 1 pt at 18mg/day, G3 diarrhea and anorexia in 1 pt, and drug compliance last values, whereas Cmax values were lower in fed condition than in fasted condition. Conclusions: Continuous daily dosing schedule of HM781-36B is safe and well tolerated in advanced solid tumors. It exerts anticancer activity, without being influenced by food. Updated data will be presented at the meeting. Clinical trial information: NCT01455584.

Background: The poly (ADP-ribose) polymerase (PARP) inhibitor, olaparib, has been found to have a therapeutic potential for treating cancers that have an impaired DNA repair ability. RAD51C has been reported to play an essential role in DNA repair mediated by homologous recombination. In addition, RAD51C is a gene that affects human cancer susceptibility, similar to BRCA1 and BRCA2. RAD51C-defective cancers can therefore be potentially treated with olaparib because DNA damage induced by olaparib cannot be effectively repaired by HR since RAD51C deficiency interferes with RAD51-mediated HR. Materials and Methods: We studied the growth inhibitory effects of olaparib on human cancer cell lines using clonogenic survival assays. Cell cycle analysis and molecular changed induced by olaparib were also performed. DNA methylation status in cancer cells and tumor tissue samples was also determined by using bisulfate sequencing. Results: Olaparib is effective to RAD51C-defective cells. Olaparib leads to the accumulation of unrepaired DSBs due to dysfunctional RAD51 foci formation along with increased caspase 3-dependent cell death and G2/M arrest in RAD51C-defective cells. Moreover, the growth of RAD51C-deficient SNU601 tumor cells in a xenograft model decreased significantly following treatment with olaparib. Furthermore, RAD51C expression was significantly decreased in cancer and the lack of RAD51C was attributed to DNA methylation and histone modification. Our findings showed that the loss of RAD51C expression due to epigenetic silencing leads to olaparib sensitivity in cancer cells. Conclusion: The loss of RAD51C expression was frequently associated with human cancers. We used a novel synthetic lethal approach using PARP inhibitors and observed that RAD51C was a participant in the DNA repair pathway. Our findings have potential clinical application for treating cancers with RAD51C deficiencies. Furthermore, we determined that RAD51C may serve as a novel biomarker for identifying olaparib-sensitive patients, thereby allowing physicians to select the most effective modalities for treating these individuals. Citation Format: Ahrum Min, Seongyeong Kim, Seock-Ah Im, Young-Kwang Yoon, Sang-Hyun Song, Hyun-Jin Nam, Hyung-Seok Hur, Kyung-Hun Lee, Sae-Won Han, Do-Youn Oh, Tae-You Kim, Mark J. O`Connor, Woo-Ho Kim, Yung-Jue Bang. Olaparib increases antitumor effects on epigenetically RAD51C-deficient human cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3442. doi:10.1158/1538-7445.AM2013-3442

Background: Amphiregulin is a ligand for the epidermal growth factor receptor (EGFR). Human epidermal growth factor receptor 2 (HER2) shares common signal pathways and forms a heterodimer with EGFR. In this study, we investigated the effect of amphiregulin on trastuzumab therapy in HER2-positive breast cancer. Methods: We analyzed serum amphiregulin levels by enzyme-linked immunosorbent assay (ELISA) from baseline serum samples obtained from HER2-positive metastatic breast cancer patients who received first-line trastuzumab plus taxane chemotherapy. In addition, in vitro experiments were performed to elucidate the biologic mechanism of clinical findings related to amphiregulin using SK-BR-3 and BT-474 cell lines. Results: Between October 2004 and July 2009, a total of 50 women with HER2-positive metastatic breast cancer were consecutively enrolled. The median age was 47 years (range, 27-72 years). Eighteen patients (36.0%) received weekly paclitaxel plus trastuzumab, 24 patients (48.0%) tri-weekly paclitaxel plus trastuzumab, and 8 patients (16.0%) tri-weekly docetaxel plus trastuzumab. Among 43 patients with measurable lesions, the response rate (RR) was 76.7%. The median follow-up duration was 29.2 months (range, 0.7-63.3 months). The median progression-free survival (PFS) was 17.6 months (95% confidence interval (CI), 13.4-21.9 months). The median overall survival (OS) was 47.0 months (95% CI, 35.3-58.6 months). The median serum amphiregulin level was 1.0 ng/mL with a maximum level of 4.4 ng/mL. Patients with high serum amphiregulin levels (≥0.5 ng/mL) had significantly shorter PFS (p=0.018) along with a tendency toward lower RR (p=0.237) and shorter OS (p=0.529) than the others. The in vitro colony forming assay demonstrated that the addition of amphiregulin resulted in increased proliferation of both SK-BR-3 and BT-474 cells. In addition, the anti-proliferative effect of trastuzumab was decreased in the presence of amphiregulin in both SK-BR-3 and BT-474 cells. The Western blot analysis showed that amphiregulin increased the phosphorylation of Akt and its downstream molecules in both SK-BR-3 and BT-474 cells. In addition, in the presence of amphiregulin, sustained phosphorylation of Akt and its downstream molecules was observed after trastuzumab treatment in both SK-BR-3 and BT-474 cells. Conclusions: High serum amphiregulin levels (≥0.5 ng/mL) predicted disease progression after first-line trastuzumab plus taxane chemotherapy in patients with HER2-positive metastatic breast cancer. Amphiregulin promoted the proliferation of HER2-positive breast cancer cells in vitro and induced trastuzumab resistance by activating PI3K/Akt pathway. Our results suggest that the measurement of serum amphiregulin levels by ELISA may provide additional information for the clinical outcome of trastuzumab-based chemotherapy in patients with HER2-positive breast cancer. Citation Format: Ji-Won Kim, Young Seok Joung, Ahrum Min, Hyun-Jin Nam, Jee Hyun Kim, Seock-Ah Im, Kyung-Hun Lee, Jin-Soo Kim, Tae-Yong Kim, Sae-Won Han, Yoon Kyung Jeon, Do-Youn Oh, Tae-You Kim, In Ae Park. Amphiregulin confers trastuzumab resistance by activating PI3K/Akt pathway in HER2-positive breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2386. doi:10.1158/1538-7445.AM2013-2386

Background: Src is a nonreceptor tyrosine kinase involved in the crosstalk and mediation of many signaling pathways that promote cell proliferation, adhesion, invasion, migration, metastasis, angiogenesis, and tumorigenesis. Elevation of Src activity has been reported in many types of human cancers. Therefore, Src has been promising therapeutic target for the treatment of cancers. However, the mechanism of Src inhibition in gastric cancers has not been fully understood yet. Saracatinib is an orally active small molecule c-Src/abl kinase inhibitor currently in phase II clinical trials. The purpose of this study is to evaluate the therapeutic potential of saracatinib alone or in combination with chemotherapeutic agents for the treatment of gastric cancers by testing its in vitro and in vivo efficacy. Methods: Experiments were conducted in human gastric cancer cell lines from the Korea Cell Line Bank or the American Type Culture Collection. MTT assay was used for determining growth inhibitory effect of saracatinib alone or in combination with chemotherapeutic agents (5-FU, cisplatin). Cell cycle distribution was analyzed by FACS Calibur flow cytometer and apoptotic effect was measured by annexin V assay. Western blot analysis was performed to verify molecular mechanism of this compound. The methods described by Chou and Talalay were used to determine if a synergistic effect existed. The analysis of the median effect was conducted using the Calcusyn software to determine a combination index value. (CI>1: antagonistic effect, CI=1:additive effect, CI Results: Saracatinib specifically inhibited the growth of SNU216 and NCI N87 cells among 10 gastric cancer cell lines. We found that saracatinib induces G1 arrest and apoptosis in sensitive cell lines. The apoptotic process required induction of the proapoptotic BH3-only BCL2 family member, BIM, and saracatinib led to increase in the BIM level in SNU216 and N87 cells. Knockdown of BIM using siRNA decreased the apoptotic cell numbers induced by treatment of saracatinib suggesting important role for BIM in saracatinib induced apoptosis pathway. The sensitivity to saracatinib in SNU216 and N87 cell lines was correlated with inhibiton of AKT and ERK pathways and blockade of HER family kinases. Furthermore, the combined treatment of saracatinib with 5-FU or cisplatin exerted synergistic effects in gastric cancer cell lines including NCI N87 cells. Consistent with these in vitro findings, saracatinib alone or in combination with 5-FU showed antitumor activity in a NCI-N87 xenograft model. Conclusion: Taken together, these preclinical evaluations support that Src is a potential therapeutic target in gastric cancer and clinical development of saracatinib alone or in combination with chemotherapy in gastric cancer could be considered. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3588. doi:10.1158/1538-7445.AM2011-3588

Background: HM781-36B is a novel quinazoline-based irreversible pan-HER inhibitor. Although the effects of many other pan-HER inhibitors (CI-1033, PF00299804, BMS-599626, BMS-690514 and JNJ-28871063) have been studied in various types of cancer, data regarding the use of pan-HER inhibitors to treat gastric cancers are limited. In this study, we evaluated the therapeutic potential of HM781-36B for the treatment of gastric cancers by testing its in vitro and in vivo efficacy. In addition, we further characterized its activity when administered in combination with chemotherapeutic agents. Methods: Experiments were conducted in gastric cancer cell lines. Enzyme activity assay was conducted to determine the IC50 values of HM781-36B for kinase inhibition and MTT assay was used for determining growth inhibitory effect. Cell cycle distribution was analyzed by flow cytometry and apoptotic effect was measured by annexin V assay. And N87 xenograft model was used to see tumor regression effect. Western blot analysis was used to verify mechanism of this compound. Results: We found that HM781-36B suppressed the proliferation of HER2-amplified gastric cancer cell lines (SNU216 and N87) potently when compared to the effects of other HER family tyrosine kinase inhibitors (gefitinib, lapatinib, BIBW-2992 and CI-1033). Furthermore, we found that HM781-36B inhibited the phosphorylation of HER family and their downstream signaling proteins, which resulted in apoptosis through the caspase-mediated mitochondrial pathway and G1 arrest. The apoptotic process requires the induction of the proapoptotic BH3-only BCL2 family member, BIM, and HM781-36B led to a dramatic increase in the BIM level in SNU216 and N87 cells. Consistent with these in vitro findings, HM781-36B showed exceptional anti-tumor activity in a xenograft model of N87 cells. Furthermore, HM781-36B exerted synergistic effects when administered in combination with 5-fluorouracil or cisplatin in both HER2 amplified cells and HER2 non-amplified gastric cancer cells. Conclusion: Taken together, these data suggest that HM781-36B may be useful as a targeted therapy for the treatment of HER2 amplified gastric cancer as well as a chemosensitizer of cytotoxic chemotherapeutic agents used to treat gastric cancer, even in HER2 non-amplified gastric cancer. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B260.

A sensitive and specific heating block method coupled with ultra-HPLC (u-HPLC) was developed for the analysis of capsaicin in Gochujang and validated by comparing with a conventional HPLC (AOAC Method 995.03). The method validation parameters yielded good results, including linearity, precision, accuracy, and recovery. The u-HPLC separation was performed on a reversed C18 column (50 2 mm id, particle size 2 m), followed by fluorescence detection (excitation 280 nm, emission 325 nm). Methanol was used as the extracting solvent, and the amount of sample taken was approximately 0.2 g; the optimum amount of extraction solvent and extraction time were 15 mL and 1 h, respectively. The recovery of capsaicin in Gochujang was more than 93, and the LOD and LOQ of the u-HPLC analysis were 0.05 and 0.16 g/g for capsaicin and 0.05 and 0.16 g/g for dihydrocapsaicin. The calibration graphs for capsaicin and dihydrocapsaicin were linear from 0.2 to 10.0 g/mL for u-HPLC. The interday and intraday precisions (RSD values) were