Near-infrared photoimmunotherapy of pancreatic cancer using an indocyanine green-labeled anti-tissue factor antibody

AIM To investigate near-infrared photoimmunotherapeutic effect mediated by an anti-tissue factor(TF) antibody conjugated to indocyanine green(ICG) in a pancreatic cancer model.METHODS Near-infrared photoimmunotherapy(NIR-PIT) is a highly selective tumor treatment that utilizes an antibody-photosensitizer conjugate administration, followed by NIR light exposure. Anti-TF antibody 1849-ICG conjugate was synthesized by labeling of rat IgG2 b anti-TF monoclonal antibody 1849(anti-TF 1849) to a NIR photosensitizer,ICG. The expression levels of TF in two human pancreatic cancer cell lines were examined by western blotting. Specific binding of the 1849-ICG to TF-expressing BxPC-3 cells was examined by fluorescence microscopy. NIR-PITinduced cell death was determined by cell viability imaging assay. In vivo longitudinal fluorescence imaging was used to explore the accumulation of 1849-ICG conjugate in xenograft tumors. To examine the effect of NIRPIT, tumor-bearing mice were separated into 5 groups:(1) 100 μg of 1849-ICG i.v. administration followed by NIR light exposure(50 J/cm2) on two consecutive days(Days 1 and 2);(2) NIR light exposure(50 J/cm2) only on two consecutive days(Days 1 and 2);(3) 100 μg of 1849-ICG i.v. administration;(4) 100 μg of unlabeled antiTF 1849 i.v. administration; and(5) the untreated control. Semiweekly tumor volume measurements, accompanied with histological and immunohistochemical(IHC) analyses of tumors, were performed 3 d after the 2nd irradiation with NIR light to monitor the effect of treatments. RESULTS High TF expression in BxPC-3 cells was observed via western blot analysis, concordant with the observed preferential binding with intracellular localization of 1849-ICG via fluorescence microscopy. NIR-PIT-induced cell death was observed by performing cell viability imaging assay. In contrast to the other test groups, tumor growth was significantly inhibited by NIR-PIT with a statistically significant difference in relative tumor volumes for 27 d after the treatment start date [2.83 ± 0.38(NIR-PIT) vs 5.42 ± 1.61(Untreated), vs 4.90 ± 0.87(NIR), vs 4.28 ±1.87(1849-ICG), vs 4.35 ± 1.42(anti-TF 1849), at Day 27, P < 0.05]. Tumors that received NIR-PIT showed evidence of necrotic cell death-associated features upon hematoxylin-eosin staining accompanied by a decrease in Ki-67-positive cells(a cell proliferation marker) by IHC examination.CONCLUSION The TF-targeted NIR-PIT with the 1849-ICG conjugate can potentially open a new platform for treatment of TF-expressing pancreatic cancer.

Overproduction of reactive oxygen species–obligatory or not for induction of apoptosis by anticancer drugs

Many studies demonstrate that conventional anticancer drugs elevate intracellular level of reactive oxygen species （ROS） and alter redox-homeostasis of cancer cells. It is widely accepted that anticancer effect of these chemotherapeutics is due to induction of oxidative stress and ROS-mediated apoptosis in cancer. On the other hand, the harmful side effects of conventional anticancer chemotherapy are also due to increased production of ROS and disruption of redox-homeostasis of normal cells and tissues. This article describes the mechanisms for triggering and modulation of apoptosis through ROS-dependent and ROS^independent pathways. We try to answer the question： ＂Is it possible to induce highly specific apoptosis only in cancer cells, without overproduction of ROS, as well as without harmful effects on normal cells and tissues？＂ The review also suggests a new therapeutic strategy for selective killing of cancer cells, without significant impact on viability of normal cells and tissues, by combining anticancer drugs with redox-modulators, affecting specific signaling pathways and avoiding oxidative stress.

Persimmon Leaf Flavonols Enhance the Anti-Cancer Effect of Heavy Ion Radiotherapy on Murine Xenograft Tumors

The cell cycle checkpoint system play a pivotal role in the cellular DNA damage response, and the discovery of checkpoint inhibitors is expected to sensitize current cancer therapies. Checkpoint signaling cascades are critically modulated by ATM (ataxia telangiectasia-mutated) and its related molecules. Generally, ATM primarily responds to ionizing irradiation-induced DNA double-strand breaks. Heavy ions from an accelerated carbon ion beam have been used to cure cancer because they are more effective than ionizing irradiation such as X-ray and γ-radiation in terms of biological damage. In a previous study, we demonstrated that a persimmon leaf flavonol (PLF) promoted the cytotoxic effect of chemotherapeutic agents on cancer cells through inhibition of checkpoint activities, especially in the ATM dependent pathway. The present study investigated whether PLF inhibits checkpoint activity during the DNA damage response induced by heavy ion irradiation. Treatment with PLF significantly increased the cytotoxicity of heavy ion irradiation in A549 adenocarcinoma cells. The phosphorylation of checkpoint proteins such as p53, SMC1, and Chk1 was increased by heavy ions. PLF reduced the phosphorylation of checkpoint proteins. Pre-treatment with PLF significantly prevented the decrease of mitotic cells in heavy ion-exposed cells. We further evaluated tumor volume in SCID mice inoculated with human lung adenocarcinoma A549 cells. The combination treatment of PLF and heavy ion resulted in a decrease of tumor volume compared with controls, although PLF itself did not exhibit any effect. These results indicate that PLF inhibits tumor growth through modulation of the DNA damage response. PLF may be useful for clinical application in combination with heavy ion radiotherapy.

Immediate-early Inducible Function in Upstream Region of junB Gene

Objective To analyze the upstream region of radiation-induced junB gene. Methods Four plasmids containing 250 bp, 590 bp, 900 bp and 1650 bp, and CAT reporter gene were constructed separately and introduced to L8704 cells. The cells were irradiated with 2 Gy X-rays and incubated at different intervals. Total RNA was extracted from the cells and fluctuation of the CAT mRNA level was assessed by the RNA ratio of CAT/β-actin measured by quantitative Northern blot hybridization. Results CAT mRNA expression containing 900 bp and 1560 bpjunB promoter remarkably and rapidly increased, and reached its peak 30min after 2 Gy X-my irradiation. Conclusions 590-900 bp fragments located in the upstream region of junB gene play an important role in the early process of cells against radiation.

A Hybrid Biofuel and Triboelectric Nanogenerator for Bioenergy Harvesting

Various types of energy exist everywhere around us,and these energies can be harvested from multiple sources to power micro-/nanoelectronic system and even personal electronic products.In this work,we proposed a hybrid energy-harvesting system(HEHS)for potential in vivo applications.The HEHS consisted of a triboelectric nanogenerator and a glucose fuel cell for simultaneously harvesting biomechanical energy and biochemical energy in simulated body fluid.These two energy-harvesting units can work individually as a single power source or work simultaneously as an integrated system.This design strengthened the flexibility of harvesting multiple energies and enhanced corresponding electric output.Compared with any individual device,the integrated HEHS outputs a superimposed current and has a faster charging rate.Using the harvested energy,HEHS can power a calculator or a green light-emitting diode pattern.Considering the widely existed biomechanical energy and glucose molecules in the body,the developed HEHS can be a promising candidate for building in vivo self-powered healthcare monitoring system.

Projectile fragment emission in the fragmentation of 56Fe on Al,C,and CH2 targets

The emission angle distribution of projectile fragments(PFs)and the temperature of PF emission sources for fragmentation of 56Fe on polyethylene,carbon,and aluminum targets at the highest energy of 497 A MeV are investigated on the basis of corrected data,using a CR-39 plastic nuclear track detector.It is found that the average emission angle of PFs increases with the decrease in PF charge for the same target,and no obvious dependence of angular distribution on the mass of the target nucleus is found for the same PF.The cumulative squared transverse momentum distribution of PFs can be well represented by a single Rayleigh distribution.The temperature of PF emission sources is extracted from the distribution,and it is about 1.0-8.0 MeV and does not depend on the mass of the target for PFs with charges of 9≤Z≤25.

Enhancement of radiosensitivity of MCF-7 breast cancer cells subjected to X-ray or carbon-ion irradiations

The sensitivity of cancer cells to radiation therapy varies based on cell cycle phase. Here we evaluated the differences between X-ray and carbon-ion irradiation with respect to cellular radiosensitivity and cancer cycle arrest in the breast cancer cell line, MCF-7. The cell survival rate, cell cycle distribution and the presence of apoptosis were measured by clonogenic assay and flow cytometry. BRCA1 and p21 protein levels were analyzed by Western blot, and the levels of human telomerase reverse transcriptase(h TERT) m RNA expression and telomere length were detected with real-time polymerase chain reaction. The results show a significant dose-dependent effects on survival rate, apoptosis and protein levels in the carbon-ion group of MCF-7 cells. Decreased proliferation was not observed at 2 Gy X-ray irradiation. There were significant differences in cellular cycle arrest, apoptosis percentages and BRCA1 and p21 protein expression between X-ray and heavy-ion groups. The results indicatedthat increasing in BRCA1 and p21 expression, and attenuation of h TERT gene expression induced by heavy-ion irradiation in MCF-7 cells might relate to mechanism of cellular radiosensitivity in G2/M arrested phase.

Combined treatment of pancreatic cancer xenograft with 90Y-ITGA6B4-mediated radioimmunotherapy and PI3K/m TOR inhibitor

AIM To investigate the therapeutic effect of combined integrin α6β4-targeted radioimmunotherapy(RIT) and PI3 K/m TOR inhibitor BEZ235 in a pancreatic cancer model.METHODS Phosphorylation of Akt, m TOR, the downstream effectors eukaryotic initiation factor 4 E binding protein 1(4 EBP1) and S6 ribosomal protein(S6) were evaluated in Bx PC-3 human pancreatic cancer cells treated with Yttrium-^(90)(^(90) Y) labeled anti-integrin α6β4 antibody(ITGA6 B4) and BEZ235 by western blotting. The cytotoxic effect of BEZ235 was investigated using a colony formation assay. Therapeutic efficacy enhancement by oral BEZ235 administration was assessed using mice bearing Bx PC-3 xenograft tumors. Tumor volume measurements and immunohistochemical analyses(cell proliferation marker Ki-67, DNA damage marker p-H2 AX and p-4 EBP1 staining) of tumors were performed for evaluation of combined treatment with ^(90) Y-ITGA6 B4 plus BEZ235, or each arm alone.RESULTS We found that phosphorylation of Akt(p-Akt), 4 EBP1(p-4 EBP1) and S6(p-S6) was inhibited by BEZ235. Colony formation in Bx PC-3 cells was additively suppressed by the combination of ^(90) Y-ITGA6 B4 and BEZ235. Pretreatment with BEZ235 before ^(90) Y-ITGA6 B4 exposure resulted in significant reduction of cells plating efficiency(PE)(0.54 ± 0.11 vs 2.81 ± 0.14 with 185 k Bq/m L ^(90) Y-ITGA6 B4 exposure, P < 0.01; 0.39 ± 0.08 vs 1.88 ± 0.09 with 370 k Bq/m L ^(90) Y-ITGA6 B4 exposure, P < 0.01) when 5 × 10~3 cells per dish were plated. In vivo, the combined treatment with ^(90) Y-ITGA6 B4 plus BEZ235 enhanced the inhibition of tumor growth and statistically significant differences of relative tumor volume were observed for 27 d after the treatment start date when compared with the ^(90) Y-ITGA6 B4 single injection treatment(1.03 ± 0.38 vs 1.5 ± 0.15 at Day 27, P < 0.05), and for 41 d when compared with the BEZ235 treatment alone(1.8 ± 0.7 vs 3.14 ± 1.19 at Day 41, P < 0.05). Tumors from treatment groups showed reduction in volumes, decreased Ki-67-positive cells, increased p-H2 AX-positive cells and decreased p-4 EBP1 expression. CONCLUSION The therapeutic efficacy of ^(90) Y-ITGA6 B4-RIT can be improved by combining with dual PI3 K and m TOR inhibitor, BEZ235, in a pancreatic cancer model suggesting potential clinical application.

Charge-Changing Cross Sections of 736 A MeV ^(28)Si on Carbon Targets

The total and partial charge-changing cross sections of 28 Si on carbon targets at 736 and 723 A Me V are studied by CR-39 plastic nuclear track detectors using the HSP-1000 microscope system and the PitFit track measurement software. The values of the total charge-changing cross section are σtot=（11794-50） mb and σtot=（11864-42） mb at 736 and 723A MeV, respectively. The result is compared with the ones obtained by other experimental and theoretical results. The odd-even effect of the partial charge-changing cross section is observed.

The ab initio Calculation of Electric Field Gradient at the Site of P Impurity in α-Al_(3)O_(2)

An ab initio calculation of the electric-field gradient(EFG)at the site of a phosphorous impurity substituting an Al atom in α-Al_(3)O_(2) is carried out using the WIEN2k code with the full-potential linearized augmented plane wave plus local orbital method(LAPW+lo)in the frame of density functional theory.The atomic lattice relaxations caused by the implanted impurities were calculated for two different charged states to well describe the electronic structure of the doped system.The EFG at the site of the phosphorous impurity in the charged supercell calculated with the exchange-correlation potential of the Wu-Cohen generalized gradient approximation(WC-GGA)is 0.573×10^(21) V/m^(2).Then,the nuclear quadrupole moment of the I=3 state in ^(28)P is deduced to be 137 mb from the quadrupole interaction frequency of 190 kHz measured recently by theβ-NQR method.

Characterization of the role of Smu1 in nuclear localization of splicing factors in the mammalian temperature-sensitive mutant

A temperature-sensitive (ts) mutant of the CHO-K1 cell line, tsTM18, grows at 340C but not at 390C. Smu1 is the gene responsible for ts defects of tsTM18 cells. Previously, we found that the Smu1 ts defect altered the localization (as indicated by enlargement of speckles) of SRSF1 (SF2/ASF) in tsTM18 cells cultured at 390C, suggesting a functional association between Smu1 and SRSF1. Speckles are subnuclear structures that may function as storage/assembly/ modification compartments to supply splicing factors to active transcription sites. The effect of the ts defect of Smu1 on the localization of other factors related to splicing has not been characterized yet. The mechanisms underlying the enlargement of speckles of SRSF1 remain unclear. In the present study, we found that the ts defect of Smu1 affected the nuclear localization of a splicing factor, SRSF2 (SC35), and factors involved in the exon-exon junction complex, Y14 and ALY. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that the ts defect of Smu1 affected alternative splicing of endogenous Clk1/ Sty and SRSF2 genes. Mammalian Clk family kinases are shown to phosphorylate serine/arginine (SR) proteins in vitro and SRSF1 in vivo. RT-PCR analysis of Clk1/Sty showed an accumulation of the truncated form lacking kinase activity in tsTM18 cells incubated at 39?C. These data indicate that an accumulation of kinase-negative Clk1/Sty may lead to alteration of the localization of factors related to splicing resulting in the enlargement of speckles.

Correction to:A Hybrid Biofuel and Triboelectric Nanogenerator for Bioenergy Harvesting

In the original publication,the authors’contribution is missing in the acknowledgment section.The correct acknowledgement is provided in this correction.Also,in Fig.4,the second(c)after figure(d)should be read as(e).In Fig.5(i),the Y-axis label“Current(μA)”should be read as“Voltage”.

Enhanced Efficiency in Cell Killing at Penetration Depths around Bragg Peak of a Radioactive 9C-ion Beam

A β-delayed particle decay beam like 9C has been recognized as a double irradiation source, i.e. the external beam radiation itself and the delayed low-energy particles emitted internally. A radioactive 9C-ion beam, therefore, is considered to be very useful in cancer radiation therapy. To explore the potential importance of radioactive 9C-ion beams in cancer therapy, radiobiological experiments using a 9C beam supplied by the secondary beam line (SBL) at the Heavy Ion Medical Accelerator in Chiba (HIMAC), Japan were carried out.

Clonogenic Surviving Effect of HSG Cells Exposed to High-LET Carbon Beams at Low Dose Rate

It is generally believed that there is no dose-rate sparing effect for mammalian cells exposed to high-LET heavy ion beams. To clarify this ambiguity, human salivary gland (HSG) cells were irradiated with carbon ion beams supplied by the Heavy Ion Medical Accelerator in Chiba (HIMAC), Japan at a low dose rate of 0.

Measurement of Lineal Energy Spectra at Different Penetration Depths along a Radioactive 9C-ion Beam

A β-delayed particle decay 9C-ion beam as a type of double irradiation source is expected to enhance the curative effect when applying it to heavy-ion cancer therapy. It has been proved in our previous