Mesenchymal stem cells modified to express interferon-β inhibit the growth of prostate cancer in a mouse model

OBJECTIVE

This study investigated use of mesenchymal stem cells (MSCs) genetically engineered to produce interferon-β (IFN-β) as a gene delivery system to treat prostate cancer in an animal model.

METHODS

To measure the effects on tumour cell growth in vitro, IFN-β-producing MSCs (IFN-β-MSCs) were co-cultured with the prostate cancer cell line PC-3. The in vivo migration of intravenously injected fluorescently-labelled MSCs to healthy tissues and PC-3 xenograft tumours grown in immuno-deficient mice was determined by fluorescence microscopy. The antitumour effects of intravenously injected IFN-β-MSCs on PC-3 xenograft growth and animal survival were also investigated.

RESULTS

IFN-β-MSCs inhibited the growth of PC-3 cells in vitro. Fluorescently-labelled MSCs migrated to the margins and centre of tumour masses but not into healthy tissues. Intravenously injected IFN-β-MSCs significantly reduced PC-3 xenograft tumour weight and increased animal survival compared with controls.

CONCLUSIONS

Intravenously injected IFN-β-MSCs inhibited PC-3 xenograft growth. This could be an effective gene delivery system for treatment of solid human tumours.

First Report of Fusarium pseudograminearum Causing Crown Rot of Wheat in Henan, China

Fusarium pseudograminearum (O'Donnell & Aoki), a residue-borne pathogen, is responsible for crown rot of wheat (Triticum aestivum L.). Since its first detection in Queensland, Australia in 1951, it has been reported in many other countries, but not China (2). In May 2011, a crown rot disease was observed in wheat cv. Aikang 58 in a wheat-maize rotation, irrigable and loam field in Henan Province, China. Diseased wheat plants showed honey brown discoloration in the stem bases and whitehead in some plants, which are symptoms of crown rot with about 70% incidence in a surveyed field (2). The pathogen was isolated from diseased stem base on potato dextrose agar (PDA) after being surface-disinfested with 5% NaClO solution for 2 min. Pure cultures were established on carnation leaf agar (CLA) through a single spore technique and identified by morphological and molecular methods according to protocols described previously (1,3,4). Macroconidia of F. pseudograminearum were formed in abundant sporodochia on CLA cultures grown under the BLB light. Macroconidia were usually five septate (about three to seven) and 27 to 91 × 2.7 to 5.5 μm. Colonies grown on PDA from a single conidium in the dark at 25°C had average radial growth rates of ~4.7 to 9.9 mm per day. Colony pigment on PDA grown under light varied from rose to burgundy, while mycelium ranged from rose to yellow white. Two isolates (WZ-8A and WZ-2B) were selected for molecular identification. The translation elongation factor 1-α gene and rDNA ITS gene were amplified by PCR using the specific primers described previously (4). PCR products were sequenced (GenBank Accession Nos. JN862232 to JN862235). Phylogenic analysis of the sequence indicated that the isolates were identified as F. pseudograminearum. The identification was further confirmed by the F. pseudograminearum species-specific PCR primers (Fp1-1: CGGGGTAGTTTCACATTTCCG and Fp1-2: GAGAATGTGATGACGACAATA) (1). The expected PCR products of 520 bp were produced only in F. pseudograminearum. Isolates WZ-2B and WZ-8A were deposited in the Agriculture Culture Collection of China as ACCC38067 and ACCC 38068, respectively. Pathogenicity tests were conducted by inoculating winter wheat cultivar Wenmai 19 with isolates WZ-8A and WZ-2B through soil inoculation. Inoculum was prepared by growing cultures on sterilized wheat bran and chopped wheat-straw (4:1, v/v) after incubation at 25°C for 2 weeks. This inoculum was added to sterilized soil at 1% by volume and no inoculum was added in control treatment. Five seeds were planted in a 15 cm wide pot in a 20 to 25°C greenhouse, with six replications. Seedling death and crown browning occurred in the inoculated wheat plants after 4 weeks with over 90% incidence, while no symptoms developed in the control plants. The fungus was reisolated from inoculated plants, fulfilling Koch's postulates. To our knowledge, this is the first report of F. pseudograminearum causing crown rot of wheat in China. Considering Henan is the largest wheat production province in China with over 5 million hectares planting area, and the soil and climate conditions are suitable for this disease, it will be a important pathogen of wheat in Henan in the future. References: (1) T. Aoki et al. Mycologia 91:597, 1999. (2) L. W. Burgess. Page 271 in: Crown Rot of Wheat: Fusarium. B. A. Summerell et al., eds. APS Press, St. Paul, MN, 2001. (3) R. G. Francis et al. Trans. Brit. Mycol. Soc. 68:421, 1977. (4) J. B. Scott et al. Mycol. Res. 110:1413, 2006.

Correlation between expression of S100A4 and VEGF-C, and lymph node metastasis and prognosis in gastric carcinoma

This semiquantitative immunohistochemical study investigated the clinical significance of S100A4 and vascular endothelial growth factor C (VEGF-C) protein expression in gastric carcinoma. Correlations between S100A4 and VEGF-C immunoreactivity and clinicopathological characteristics were evaluated using 108 gastric carcinoma specimens and 20 specimens of tissue adjacent to gastric carcinoma. S100A4 and VEGF-C expression in carcinoma was higher than that in adjacent tissues. S100A4 expression was significantly related to tumour size and lymph node metastasis, whereas VEGF-C expression was associated with invasion depth, lymph node metastasis and tumour, node, metastasis (TNM) stage. A significant correlation was found between S100A4 and VEGF-C expression. Patients expressing S100A4 or VEGF-C showed no significant reduction in 5-year survival rate compared with those not expressing these proteins. Sex, age, tumour size, invasion depth, lymph node involvement, TNM stage, S100A4 expression and VEGF-C expression had a common effect on carcinoma prognosis but none was an independent prognostic factor.

Antigen-specific T-regulatory cells can extend skin graft survival time in mice

This study investigated the effects of donor antigen-specific CD4(+)CD25(+) T-regulatory cells (Tregs) on skin allografts in mice. An allogeneic skin transplant model was established using donor C57BL/6 or DBA and recipient BALB/c mice. Recipients were divided into 4 groups: control group without intervention (CON; C57BL/6 to BALB/c), rapamycin gavage group (RAP; C57BL/6 to BALB/c), CD4(+)CD25(+) Tregs-treated group (TRE; C57BL/6 to BALB/c), in which recipients received transfusions of CD4(+)CD25(+) Tregs stimulated with C57BL/6-derived immature dendritic cells, and the third-party donor group (DBA; DBA to BALB/c) in which recipients received transfusions of BALB/c CD4(+)CD25(+) Tregs stimulated with C57BL/6-derived immature dendritic cells. Mean (SD) survival time of the skin allografts in the TRE group was 17.0 (3.4) days, significantly longer than in the other groups: CON, 6.9 (1.9) days; RAP, 10.3 (3.0) days; and DBA, 10.8 (3.6) days. The TRE group demonstrated a significantly greater expression of transforming growth factor-β and interleukin (IL)-10. Donor antigen-specific CD4(+)CD25(+) Tregs effectively extend skin allograft survival in mice.

First Record of the Cereal Cyst Nematode Heterodera filipjevi in China

Cereal cyst nematode (CCN) is now recognized as a widespread and often damaging parasite of wheat in China. Only Heterodera avenae has been reported in China (4). However, molecular analysis of four samples from Beijing and one from Shanxi Province indicated genetic differences from H. avenae and other named species (3). Here we report the detection of H. filipjevi at a site in Henan Province that was not included in any previous study or report. The infested crop was rainfed winter wheat (Triticum aestivum) cv. Wenmai 19 in a field near Banpopu Village in Xuchang County (34.0447°N, 113.7415°E) with a long-established maize-wheat semiannual crop rotation. During the winter growing season, the crop was patchy with uneven growth and cyst nematode females were observed on the roots. In June 2009, soil was collected and mature cysts were extracted for morphological and molecular identification. Cysts were also kept at 4°C for 2 months and then incubated in shallow water at 15°C for a month to obtain second-stage juveniles (J2). Measurements (range; mean ± sd) of 10 cysts were body length including neck (569 to 786 μm; 699 ± 56), body width (403 to 600 μm; 523 ± 55), length:width ratio (1.3 to 1.5; 1.3 ± 0.1), neck length (61 to 125 μm; 106 ± 19) and width (49 to 83 μm; 69 ± 13), fenestra length (52 to 59 μm; 57 ± 2.9) and width (24.5 to 34.4; 27.9 ± 3.5), underbridge (64 to 101 μm; 85 ± 10), and vulval slit (7.4 to 10.0 μm; 9.6 ± 1.0). Lemon-shaped cysts were brown with a surface zigzag pattern. The vulval cone was bifenestrate with horseshoe-shaped semifenestra, with heavy underbridge and many bullae. The J2 (n = 22) measurements were body length (496 to 590 μm; 552 ± 24), body width (20.0 to 23.8; 21.5 ± 0.9), stylet (22.8 to 25.3; 24.0 ± 1.0) with anchor-shaped basal knobs, tail (47 to 64; 61.6 ± 4.4), and hyaline tail terminus (32 to 43; 40.2 ± 3.0). The J2 had up to four lateral lines, but the inner two were often the only lines clearly visible, and the shape of the stylet knobs, tail, and tail terminus were consistent with H. filipjevi. All morphological data and characters were consistent with H. filipjevi (1). Specimens have been lodged with the Australian National Insect Collection. DNA from single cysts was extracted to amplify the internal transcribed spacer region of rDNA by PCR with forward primer TW81 (5'-GTTTCCGTAGGTGAACCTGC-3') and reverse primer AB28 (5'-ATATGCTTAAGTTCAGCGGGT-3') (2). The PCR product was sequenced (Genbank Accession No. HM027892) and digested by restriction enzymes (AluI, CfoI, HaeI, HinfI, PstI, RsaI, TaqI, and Tru9I) to obtain restriction fragment length polymorphism profiles (2). Profiles for the Xuchang population consistently matched those published for H. filipjevi and were distinct from those of H. avenae and other species (3). Phylogenic analysis of the sequence further indicated conspecificity with H. filipjevi. These morphological and molecular data confirmed that the specimens from Xuchang were H. filipjevi, which represents the first detection of H. filipjevi in China, and extends the known distribution of the species from Europe, North America, South Asia, and West Asia to East Asia. This finding adds complexity to the management of CCN in China, especially for control by host resistance, which now must consider both species and pathotype diversity. References: (1) Z. A. Handoo. J. Nematol. 34:250, 2002. (2) S. A. Subbotin et al. Nematology 2:153, 2000. (3) S. A. Subbotin et al. Nematology 5:515, 2003. (4) H. X. Yuan et al. Australas. Plant Pathol. 39:107, 2010.

In situ thin film growth stresses during chemical ordering

The in situ growth stress and postgrowth stress relaxation during the L1(0) chemical ordering of Fe0.54Pt0.46 thin films have been characterized. The compressive stress is reduced with an increase in order parameter. The postgrowth stress relaxation rate increased with the order parameter and is rationalized in terms of an increase in the interfacial energy contribution at the grain boundaries because of chemical order. Density functional theory calculations were performed to quantify possible diffusion pathways and binding energies for Fe and Pt that may mitigate surface migration.