Anticancer peptides from induced tumor-suppressing cells for inhibiting osteosarcoma cells

Osteosarcoma (OS) is the most frequent primary bone cancer, which is mainly suffered by children and young adults. While the current surgical treatment combined with chemotherapy is effective for the early stage of OS, advanced OS preferentially metastasizes to the lung and is difficult to treat. Here, we examined the efficacy of ten anti-OS peptide candidates from a trypsin-digested conditioned medium that was derived from the secretome of induced tumor-suppressing cells (iTSCs). Using OS cell lines, the antitumor capabilities of the peptide candidates were evaluated by assaying the alterations in metabolic activities, proliferation, motility, and invasion of OS cells. Among ten candidates, peptide P05 (ADDGRPFPQVIK), a fragment of aldolase A (ALDOA), presented the most potent OS-suppressing capabilities. Its efficacy was additive with standard-of-care chemotherapeutic agents such as cisplatin and doxorubicin, and it downregulated oncoproteins such as epidermal growth factor receptor (EGFR), Snail, and Src in OS cells. Interestingly, P05 did not present inhibitory effects on non-OS skeletal cells such as mesenchymal stem cells and osteoblast cells. Collectively, this study demonstrated that iTSC-derived secretomes may provide a source for identifying anticancer peptides, and P05 may warrant further evaluations for the treatment of OS.

A system for detecting high impact-low frequency mutations in primary tumors and metastases

Tumor complexity and intratumor heterogeneity contribute to subclonal diversity. Despite advances in next-generation sequencing (NGS) and bioinformatics, detecting rare mutations in primary tumors and metastases contributing to subclonal diversity is a challenge for precision genomics. Here, in order to identify rare mutations, we adapted a recently described epithelial reprograming assay for short-term propagation of epithelial cells from primary and metastatic tumors. Using this approach, we expanded minor clones and obtained epithelial cell-specific DNA/RNA for quantitative NGS analysis. Comparative Ampliseq Comprehensive Cancer Panel sequence analyses were performed on DNA from unprocessed breast tumor and tumor cells propagated from the same tumor. We identified previously uncharacterized mutations present only in the cultured tumor cells, a subset of which has been reported in brain metastatic but not primary breast tumors. In addition, whole-genome sequencing identified mutations enriched in liver metastases of various cancers, including Notch pathway mutations/chromosomal inversions in 5/5 liver metastases, irrespective of cancer types. Mutations/rearrangements in FHIT, involved in purine metabolism, were detected in 4/5 liver metastases, and the same four liver metastases shared mutations in 32 genes, including mutations of different HLA-DR family members affecting OX40 signaling pathway, which could impact the immune response to metastatic cells. Pathway analyses of all mutated genes in liver metastases showed aberrant tumor necrosis factor and transforming growth factor signaling in metastatic cells. Epigenetic regulators including KMT2C/MLL3 and ARID1B, which are mutated in >50% of hepatocellular carcinomas, were also mutated in liver metastases. Thus, irrespective of cancer types, organ-specific metastases may share common genomic aberrations. Since recent studies show independent evolution of primary tumors and metastases and in most cases mutation burden is higher in metastases than primary tumors, the method described here may allow early detection of subclonal somatic alterations associated with metastatic progression and potentially identify therapeutically actionable, metastasis-specific genomic aberrations.

Abstract 2267: Sulforaphane depresses proliferation and induces cell death in glioblastoma multiforme (GBM) cells, GBM stem cell-like spheroids, and tumor xenografts through modulation of multiple cell signaling pathways

Glioblastoma multiforme (GBM) comprises the largest group of brain tumors which are drug resistant and respond very poorly to the current therapies. In this study, we used sulforaphane (SFN), a multi-targeting agent with cancer preventive and anti-cancer activities and showed that it targets GBM established cell lines, early primary cultures, and CD133+ GBM stem cells as well as in GBM stem-like spheroids. SFN at 5-50 μM triggered significant inhibition of cell survival and induced apoptotic cell death in GBM cells and CD133+ stem cells isolated from four GBM cell lines. SFN induced apoptosis in U87MG cells was associated with caspase-7 activation. Moreover, SFN triggered formation of intracellular reactive oxygen species (ROS) and when the cells were pre-treated with 10 mM N-acetyl cysteine (NAC), ROS production and cell survival in cells treated with 5-10 μM were similar to the control untreated U87MG cells, revealing that SFN-triggered cell death is ROS-dependent. Moreover, SFN-generated ROS in U87MG cells were formed at the Mitochondrial Respiratory Chain (MRC) level. SFN also increased expression of the TRAIL receptor DR5 in GBM cells, U87MG and SF767 cells by 24 h post-exposure. Moreover, as revealed by comet assay, SFN increased single- and double-strand DNA breaks in GBM. Compared to untreated control cells, a significantly higher amount of γ-H2AX foci and as consequence higher number of DNA double-strand breaks (DSBs) breaks were observed in the SFN-treated sample. In vivo studies, using NOD/SCID mice revealed that SFN administration via oral gavage at 100 mg/kg for 3 cycles significantly decreases the growth of ectopic xenografts established from the early passage primary cultures of GBM10. Our results show that SFN robustly inhibits growth of GBM cells in vitro and in vivo and induces cell death in established cell cultures, early passage primary cultures, as well as it is effective in eliminating GBM cancer stem cells, which play a major role in drug resistance and disease recurrence. These results suggest that use of SFN alone or in combination with other agents, may potentially improve survival of brain tumor patients.

Citation Format: Khadijeh Bijangi-Vishehsaraei, Mohammad R. Saadatzadeh, Haiyan Wang, Malgorzata M. Kamocka, Wenjing Cai, Aaron A. Cohen-Gadol, Stacey L. Halum, Karen E. Pollok, Jann N. Sarkaria, Ahmad R. Safa. Sulforaphane depresses proliferation and induces cell death in glioblastoma multiforme (GBM) cells, GBM stem cell-like spheroids, and tumor xenografts through modulation of multiple cell signaling pathways. [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 2267. doi:10.1158/1538-7445.AM2014-2267

Production of the mycelial phase of Malassezia in vitro

To study the pathogenicity of Malassezia, the agent of pityriasis versicolor, it is necessary to obtain the mycelial form in vitro. A range of different components and conditions were tested to induce yeast cells of the organism to produce mycelia in vitro using different culture media. A mycelial culture medium was developed that consisted of bacteriological peptone, glucose, yeast extract, ox bile, glycerol, glycerol monostearate, Tween 80, squalene, glycine, potassium nitrate, sodium chloride, ferrous sulphate and magnesium sulphate with or without agar. The liquid and solid medium had a pH of 5.6 and the temperature of incubation was 30 degrees C. Cultures were incubated in air. This medium was able to induce some strains of Malassezia to produce up to 40% mycelium in vitro. In total, 33 different strains of Malassezia obtained from the skin of the healthy individuals and patients with pityriasis versicolor were tested for mycelium production. The strains of Malassezia capable of producing mycelium in vitro all possessed the serovar A antigen.

Quantitative analysis of wear and wear debris from metal-on-metal hip prostheses tested in a physiological hip joint simulator

Osteolysis and loosening of artificial joints caused by UHMWPE wear debris has prompted renewed interest in metal-on-metal (MOM) hip prostheses. This study investigated the wear and wear debris morphology generated by MOM prostheses in a physiological anatomical hip simulator for different carbon content cobalt chrome alloys. The low carbon pairings demonstrated significantly higher "bedding in" and steady state wear rates than the mixed and high carbon pairings. The in vitro wear rates reported here were up to one or two orders of magnitude lower than the clinical wear rates for first-generation MOM hip prostheses. Two methods for characterising the metal wear debris were developed, involving digestion, scanning electron microscopy and transmission electron microscopy. The metal wear particles characterised by the two methods were similar in size, 25-36 nm, and comparable to particles isolated from periprosthetic tissues from first and second-generation MOM hip prostheses. Due to the small size of the metal particles, the number of particles generated per year for MOM prostheses in vitro was estimated to be up to 100 times higher than the number of polyethylene particles generated per year in vivo. The volumetric wear rates were affected by the carbon content of the cobalt chrome alloy and the material combinations used. However, particle size and morphology was not affected by method of particle characterisation, the carbon content of the alloy or material combination.

Cell-mediated immunity to the mycelial phase of Malassezia spp. in patients with pityriasis versicolor and controls

BACKGROUND

Malassezia is the aetiological agent of pityriasis versicolor. The mycelial phase of the organism predominates in lesions of pityriasis versicolor.

OBJECTIVES

To evaluate the cell-mediated immune (CMI) response to the mycelial phase of Malassezia in patients with this disease, which has not previously been studied.

METHODS

The CMI status of 12 patients with pityriasis versicolor and 12 age- and sex-matched controls to mycelial antigen(s) of the organism was examined. The responses to the mycelial form of three strains of the organism were assessed using lymphocyte transformation and leucocyte migration inhibition assays.

RESULTS

The transformation responses of the lymphocytes from both patients and controls gave transformation indices < or = 3, although the responses of lymphocytes from patients with pityriasis versicolor to the mycelial form of Malassezia strains were generally higher than those of the controls. In the leucocyte migration inhibition assay, leucocytes from patients with pityriasis versicolor and controls responded to the mycelial antigens of three different Malassezia strains; however, there was no significant difference in leucocyte response between patients with pityriasis versicolor and controls.

CONCLUSIONS

Patients with pityriasis versicolor do not therefore have a CMI deficiency to Malassezia mycelial antigens but fail to generate a protective CMI response to mycelial antigens over and above that of control individuals during active disease.