Astragalus membranaceus lectin (AML) induces caspase-dependent apoptosis in human leukemia cells

OBJECTIVES

Recently, plant lectins have attracted great interest due to their various biological activities such as anti-cancer, anti-fungal and anti-viral activities. We have reported earlier concerning anti-proliferation of human cancer cell lines by a galactose-binding lectin (AML), from a Chinese herb, ASTRAGALUS MEMBRANACEUS: In the present study, detailed investigations into the mechanism of such anti-proliferation properties have been carried out.

MATERIALS AND METHODS

Mechanism of apoptosis initiation in K562 cells by AML was investigated by morphology, flow cytometry and western blot analysis.

RESULTS

AML induced apoptosis in a caspase-dependent manner in the chronic myeloid leukemia cell line, K562. Furthermore, we observed that cytotoxicity and apoptosis of K562 cells induced by AML were completely abolished in presence of lactose or galactose.

CONCLUSIONS

Our results suggest that AML could act as a potential anti-cancer drug.

Endovascular treatment of paraclinoid aneurysms

The anatomical complexity of the paraclinoid region has made surgical treatment of intracranial ophthalmic segment aneurysms (OSAs) difficult. This study evaluated the safety and efficacy of endovascular treatment of paraclinoid aneurysms. We conducted a retrospective study of 28 patients with 30 aneurysms of the paraclinoid in whom treatment with endovascular techniques was attempted. Patient age, sex, presence of subarachnoid hemorrhage, aneurysm type, size of aneurismal sac and treatment modality were reviewed. Clinical evaluation and control angiography were performed between one and 43 months. Overall, complete occlusion was obtained in 26 aneurysms (86.6%), nearly complete (>90%) occlusion in two aneurysms (6.7%) and incomplete occlusion was observed in two aneurysms (6.7%). All endovascular techniques were successful. Procedure-related complications were observed in two patients (7.1%). Patients underwent follow-up for a mean of 14.8 months (range 1-43 months). Repeated coil treatment was performed in one patient. One patient died of massive brain infarction six days postoperatively and thus no follow-up data were available for this case. In 27 patients with follow-up studies, aneurysm closure was complete in 22 (81.5%) and incomplete in five (18.5%). Endovascular treatment is a safe and efficient alternative approach for paraclinoid aneurysms.

P3-18-03: In Vitro Potency of mTOR Kinase (TOR1/TOR2) Inhibitor, INK128 in ER+ and HER2 Overexpressing Breast Cancer Cells

Background

Persistent activation of the PI3K-AKT-mTOR1/2 signaling pathway drives aberrant cell growth and proliferation in a variety of tumor types including breast tumors. Recent works have demonstrated a strong association between mutational activation of PIK3CA or loss of function of PTEN and resistance to therapies targeted against the ER or HER2 pathway.

Purpose: Since PI3K-AKT-mTOR is one of the major signaling pathways responsible for the progression of breast cancer, as well as appears to be upregulated during development of the resistance to the endocrine and trastuzumab treatment, suppression of this pathway by administration of INK128 (mTOR1/2 kinase inhibitor) may therefore be efficacious in ER+ and HER2+ breast cancer models.

Experimental Design: To examine this possibility, INK128 was treated in ER+ (MCF7, BT483, T47D and MDA-MB-415), trastuzumab-sensitive HER2+ (BT474), trastuzumab-resistant (BT474HR), and PIK3CA mutated/HER2+ breast cancer cells (HCC1954 and UACC893). We have tested the effects of INK128 on the, (a) cell survival/proliferation, (b) integrin-directed cell migration, and small GTP-ase activation, (c) downstream signaling pathways for proliferation and apoptosis, and (d) 3D ON-TOP-colony formation.

Results: Treatment of ER+ and HER2+ cell lines with INK128 in vitro showed that 1) cell lines were sensitive to single agent INK128 with 50% inhibitory concentration ranging from 15 nM-10 μM in ER+ cell lines and 20 nM −50 nM in HER2+ cell lines, 2) 70–80% anti-proliferative activities were observed on 3D-ON TOP colony formation assay in both ER+ and HER2+ cells, 3) INK128 dose- and time-dependently blocked downstream effectors of mTOR1/2 pathway i.e. p-AKT (at Ser473), p-P70S6K, p-S6 ribosomal protein, p-4EBP1(interestingly, potent inhibition was also observed in cell line resistant to trastuzumab), 4) INK128 also blocked AKT phosphorylation at Thr308 (although in lesser extent than at Ser473), 5) rapalog-mediated AKT activation was blocked when cells were treated with INK128, 6) in ER+ cell lines INK128 more efficiently blocked p-4EBP1 than rapalog, 7) HER3 expression was significantly upregulated following treatment of trastuzumab-resistant cells (BT474HR) with INK128, and 8) integrin-dependent cell migration was significantly abrogated with INK128 in association with inhibition of RAC1-GTP.

Conclusion: Our preclinical in vitro data demonstrate that concurrent inhibition of mTOR1and mTOR2 is likely to be a more effective in both ER+ and HER2+ breast cancer cells than the inhibition of mTOR1 alone. We are currently studying the effect of INK128 on downstream apoptotic signals in ER+ and HER2+ cell lines, the results of which will be presented in the meeting.

INK128 was generously supplied by Inkellikine, San Diego, CA.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-18-03.

Identification of three MICA alleles in the genotype of a patient with chronic lymphocytic leukemia

Major histocompatibility complex (MHC) class I-related chain A gene (MICA) sequence-based genotyping (SBT) was attempted on a peripheral blood sample collected from a patient evaluated for hematopoietic stem cell retransplant. The electropherogram pattern of MICA SBT indicated the possibility of carrying more than two MICA alleles. Subsequent cloning and sequencing of the polymerase chain reaction products revealed the presence of three distinct MICA alleles: MICA*008:01/:04 (A5.1), MICA*007:01(A4), and MICA*002:01 (A9) in the genotype of this patient. The origin of the third extra MICA allele could not be determined and would require MICA genotyping information from other family members, which is unavailable.

Switching of ± 360° domain wall states in a nanoring by an azimuthal Oersted field

We demonstrate magnetic switching between two 360° domain wall vortex states in cobalt nanorings, which are candidate magnetic states for robust and low power magnetoresistive random access memory (MRAM) devices. These 360° domain wall (DW) or 'twisted onion' states can have clockwise or counterclockwise circulation, the two states for data storage. Reliable switching between the states is necessary for any realistic device. We accomplish this switching by applying a circular Oersted field created by passing current through a metal atomic force microscope tip placed at the center of the ring. After initializing in an onion state, we rotate the DWs to one side of the ring by passing a current through the center, and can switch between the two twisted states by reversing the current, causing the DWs to split and meet again on the opposite side of the ring. A larger current will annihilate the DWs and create a perfect vortex state in the rings.

Free vascularised fibular graft for post-traumatic osteonecrosis of the femoral head in teenage patients

Free vascularised fibular grafting has been reported to be successful for adult patients with osteonecrosis of the femoral head (ONFH). However, its benefit in teenage patients with post-traumatic ONFH has not been determined. We evaluated the effectiveness of free vascularised fibular grafting in the treatment of this condition in children and adolescents. We retrospectively analysed 28 hips in 28 patients in whom an osteonecrotic femoral head had been treated with free vascularised fibular grafting between 2002 and 2008. Their mean age was 16.3 years (13 to 19). The stage of the disease at time of surgery, and results of treatment including pre- and post-operative Harris hip scores, were studied. We defined clinical failure as conversion to total hip replacement. All patients were followed up for a mean of four years (2 to 7). The mean Harris hip score improved from 60.4 (37 to 84) pre-operatively to 94.2 (87 to 100) at final follow-up. At the latest follow-up we found improved or unchanged radiographs in all four initially stage II hips and in 23 of 24 stage III or IV hips. Only one hip (stage V) deteriorated. No patient underwent total hip replacement. Free vascularised fibular grafting is indicated for the treatment of post-traumatic ONFH in teenage patients.

Description of two new MICA alleles: MICA*058 and MICA*002:03

We describe two novel alleles, MICA*058 and MICA* 002:03.

Characterization of the genomic full-length sequence of C*04:03 and C*04:06 in Chinese Han individuals

The genomic full-length sequences of C*04:03 and C*04:06 were first identified by cloning and sequencing.

Optical high temperature sensor based on enhanced green upconversion emissions in Er3+-Yb3+-Li+ codoped TiO2 powders

The Er3+-Yb3+-Li+ codoped TiO2 powders have been prepared by sol-gel method. The strong enhancement of green and red upconversion emissions were obtained for Er3+-Yb3+ codoped TiO2 by additional Li+ codoping and investigated using 976 nm semiconductor laser diode excitation. The enhanced upconversion emissions by the addition of Li+ resulted from the formation of Li compound with lower crystal field symmetry. The fluorescence intensity ratio (FIR) of green upconversion emissions from the transitions of 2H(11/2) --> 4I(15/2) and 4S(3/2) --> 4I(15/2) of Er3+ in the Er3+-Yb3+-Li+ codoped TiO2 has been studied as a function of temperature in the range of 300-925 K, and the maximum sensitivity was determined to be 0.0025 K(-1). Er3+-Yb3+-Li+ codoped TiO2 material with the highest operating temperature up to 925 K, has higher temperature sensitivity and fluorescence efficiency being a promising candidate for applications in optical high temperature sensor.

Biological characteristics of a cell subpopulation in tongue squamous cell carcinoma

OBJECTIVES

To isolate the CD133+CD44+ cells from human tongue squamous cell carcinoma (TSCC) Tca8113 cell line and investigate biological characteristics of them.

MATERIALS AND METHODS

Immunomagnetic microbeads were applied to sort the CD133+CD44+ cells. Flow cytometry was used to detect isolation purity. The proliferation, clone-formation efficiencies, invasion and migration, gene expressions, and tumor-formation abilities were analyzed among CD133+CD44+, CD133-CD44-, and total population of cells.

RESULTS

The average purities of CD133+ and CD44+ cells reached 97.3% and 98.7%, respectively. The proliferation of CD133+CD44+ cells was significantly higher than the other two groups. The clone-forming efficiency of three groups was 70%, 8%, and 14%, respectively. The average invaded and migrated cell numbers of CD133+CD44+ and total population cells were 132 and 36.2, 311.6, and 156.2, respectively. The expressions of Bcl-2 and Sox2 in CD133+CD44+ cells were significantly higher than those in total population cells. A total of 10(4) CD133+CD44+ cells could form secondary tumors in nude mice, while the total population group needed 10(6) cells.

CONCLUSIONS

The CD133+CD44+ subpopulation cells possess stem-like characteristics. They appear to be the potential targets for future biology therapy of human TSCC.

454 EST analysis detects genes putatively involved in ginsenoside biosynthesis in Panax ginseng

Panax ginseng C.A. Meyer is one of the most highly valued medicinal plants in the world. To analyze the transcriptome of P. ginseng and discover the genes involved in ginsenoside biosynthesis, cDNAs derived from the total RNA of 11-year-old, wood-grown P. ginseng roots were analyzed by 454 sequencing. A total of 217,529 high quality reads (expressed sequence tags, ESTs), with an average length of 409 bases, were generated from a one-quarter run to yield 31,741 unique sequences. The majority (20,198; 63.6%) of the unique sequences were annotated using BLAST similarity searches. A total of 16,810 and 16,577 unique sequences were assigned to functional classifications and biochemical pathways based on Gene Ontology analysis and the Kyoto Encyclopedia of Genes and Genomes assignment, respectively. Nine genes involved in the biosynthesis of ginsenoside skeletons and many candidate genes putatively responsible for modification of the skeletons, including 133 cytochrome P450s and 235 glycosyltransferases, were identified. From these candidates, six transcripts encoding UDP-glycosyltransferases that were most likely to be involved in ginsenoside biosynthesis were selected. These results open a new avenue by which to explore and exploit biosynthetic and biochemical properties that may lead to drug improvement. These 454 ESTs will provide the foundation for further functional genomic research into the traditional herb P. ginseng or its closely related species.