| 1. |
- Hallberg, D, et al.
(författare)
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Donor-derived myofibroblasts in the ocular surface after allogeneic haematopoetic stem cell transplantation
- 2006
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Ingår i: Acta Ophthalmologica Scandinavica. - 1395-3907. ; 84, s. 774-780
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT. Purpose: To identify and characterize cells of donor origin in the ocular surface of female recipients who have undergone allogeneic haematopoietic stem cell transplantation (allo-SCT) from a male donor. Methods: Cytological impressions from the eyes of nine allografted patients (17 eyes) were analysed. Donor cells were identified using sex-chromosomespecific fluorescence in situ hybridization (FISH). Cells were characterized by immunohistochemistry (IHC) using the CK3 and CK19 epithelial markers, the panleucocytic marker CD45 and the myofibroblast marker a-SMA. Results: No epithelial cells of donor origin were observed in the corneal or conjunctival samples. Cells of donor origin were found in the corneal samples, although these were often too degraded to allow characterization by IHC. In the conjunctiva, a median of 86% of the total number of cells were of recipient origin, including a subgroup (2%) of giant cells exhibiting polyploidy (range 4–18 n), found in the limbal region. Donor cells were detected in the conjunctiva of all nine patients at a median ratio of 9%, of which two-thirds were CD45+⁄ a-SMA+. Conclusions: We observed superficially located myofibroblasts of donor origin in all allografted patients, but not in samples from healthy controls. Whether myofibroblasts are implicated in ocular graft-versus-host disease requires further studies.
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| 2. |
- Levan, G, et al.
(författare)
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Selective gene amplification in mammalian cells
- 1984
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Ingår i: Hereditas. - : Wiley-Blackwell Publishing, Inc.. - 0018-0661. ; , s. 278-
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Konferensbidrag (refereegranskat)abstract
- Selective gene amplification in mammalian cells is now recognized as a common cellular response to selection in a number of different toxic drugs, such as methotrexate (MTX). coformycin, PALA, hydroxyurea (HU), vincristine (VCR). colcemid (COL) and actinomycin D (AMD). Recently, we have studied SEWA murine tumor cells in culture exhibiting the pleiotropic drug resistance (PDR) phenotype. Cells subjected to stepwise selection in AMD, VCR or COL all develop double minute chromosomes (DM), which are a cytogenetic expression of gene amplification. These lines overproduce a 21 K acidic soluble protein and show a high degree of cross resistance, which is typical for the PDR phenotype. Other workers have shown that cells with this phenotype exhibit a shift in membrane-bound glycoproteins from 90- 100 K to 150-170 K. Thus, it is likely that several genes are involved in the development of the PDR phenotype. We have isolated a fraction highly enriched in DM from an AMD-resistant SEWA subline. DNA was extracted from this fraction, and several DM-specific DNA-probes were developed. These probes were used to study independently derived SEWA sublines resistant to AMD, VCR, COL, MTX and HU. The results showed that the investigated amplified DNA-segments in AMD-, VCR-. and COL-resistant lines exhibited a high degree of sequence sequence homology, indicating that basically the same segment was amplified in the 3 inductions. In contrast. the amplified DNA-segments in MTX- and HU-resistant lines that do not show the PDR phenotype, displayed no sequence homology to the probes used.
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| 3. |
- Parkinson, Gabrielle T., et al.
(författare)
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Patient-derived scaffolds as a model of colorectal cancer
- 2021
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Ingår i: Cancer Medicine. - : Wiley. - 2045-7634. ; 10:3, s. 867-882
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Tidskriftsartikel (refereegranskat)abstract
- Background Colorectal cancer is the second most common cause of cancer-related death worldwide and standardized therapies often fail to treat the more aggressive and progressive types of colorectal cancer. Tumor cell heterogeneity and influence from the surrounding tumor microenvironment (TME) contribute to the complexity of the disease and large variability in clinical outcomes. Methods To model the heterogeneous nature of colorectal cancer, we used patient-derived scaffolds (PDS), which were obtained via decellularization of surgically resected tumor material, as a growth substrate for standardized cell lines. Results After confirmation of native cell absence and validation of the structural and compositional integrity of the matrix, 89 colorectal PDS were repopulated with colon cancer cell line HT29. After 3 weeks of PDS culture, HT29 cells varied their gene and protein expression profiles considerably compared to 2D-grown HT29 cells. Markers associated with proliferation were consistently decreased, while markers associated with pluripotency were increased in PDS-grown cells compared to their 2D counterparts. When comparing the PDS-induced changes in HT29 cells with clinically relevant tumor information from individual patients, we observed significant associations between stemness/pluripotency markers and tumor location, and between epithelial-to-mesenchymal transition (EMT) markers and cancer mortality. Kaplan-Meier analysis revealed that low PDS-induced EMT correlated with worse cancer-specific survival. Conclusions The colorectal PDS model can be used as a simplified personalized tool that can potentially reveal important diagnostic and pathophysiological information related to the TME.
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| 4. |
- Ståhl, Fredrik, et al.
(författare)
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Amplification and overexpression of the mouse mdria gene in nine independently selected multidrug-resistant SEWA murine cell lines
- 1993
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Ingår i: Hereditas. - : Wiley-Blackwell Publishing, Inc.. - 0018-0661 .- 1601-5223. ; 118:2, s. 121-130
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Tidskriftsartikel (refereegranskat)abstract
- Many different drugs may be used in selecting cells for multidrug resistance (MDR). Enhanced expression and/or gene amplification is known to cause overproduction of membrane-bound 170,000 P-glycoproteins, responsible for the MDR. In rodents, the P-glycoproteins are encoded by a small gene family: mdr 1a, mdr 1b, and mdr2. To evaluate the relationship between the pattern of MDR and the selecting drug, nine MDR sublines were independently selected from a sensitive mouse tumor cell line, SEWATC13K, using three different drugs. Each MDR subline displayed amplification of one or more of the three mdr genes, but only one, mdr 1a, was consistently overexpressed. Thus, our results indicate that the pattern of mdr gene amplification and overexpression is independent of the selective agent. Furthermore, in four of the MDR sublines, where all three mdr genes had been originally amplified, pulsed field gel electrophoresis (PFGE) revealed that amplification of mdr 1a, only, was a second step of gene amplification. In addition, the gene for the calcium-binding protein, sorcin, was coamplified in eight of the nine MDR sublines. The sorcin gene was overexpressed in seven of these eight sublines. Finally, hybridizations with a probe homologous with a putative region of RFLP (restriction fragment length polymorphism), indicated that the amplified sequences originate from one or the other of the two homologous chromosomes with no preference.
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| 5. |
- Ståhl, Fredrik, et al.
(författare)
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OFAGE analysis of large DNA restriction fragments from multidrug resistant SEWA mouse cells
- 1990
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Ingår i: Hereditas. - : Wiley-Blackwell Publishing, Inc.. - 0018-0661. ; , s. 9-
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Konferensbidrag (refereegranskat)abstract
- The aim of this study is to detect similarities and differences in the gene amplification process, when MDR cells develop after selection in different drugs. For this purpose, nine independent MDR sublines of the murine SEWA TC13K cell line were established by stepwise selection in actinomycinD( Al,A2,A4),colcemid(Cl,C2,C3),or vincristine (Vl, V3, V4). All MDR sublines displayed numerous DMs. DNA from all lines was digested with EcoRl and the infrequently cutting enzyme SfiI. DNA-fragments from the SfiI-digests were separated by orthogonal field alterating gel electrophoresis (OFAGE). Hybridizations were made with two probes: (1) cp28, a Chinese hamster P-glycoprotein cDNA sequence, kindly supplied by Dr Alexander Van der Bliek, The Netherlands Cancer Institute in Amsterdam; (2) Ie7, a genomic clone from a DM mini-library (Stihl et al., Hereditas 106:97, 1987). The hybridization patterns of the Sfildigests were very similar for both probes, while the patterns of the EcoRI-digests differed considerably. No drugspecific amplification pattern was revealed. The Ie7 probe did not cross-hybridize to the cp28 cDNA-sequence. However, low stringency hybridization of Ie7 to a 4.5 kb mRNA (hamster) has been reported (Diddens et al., Int. J. Cancer 40:635, 1987). Still, the similarities in the hybridization patterns suggest that Ie7 DNA-sequence is located close to the cp28 DNA-sequence, perhaps as a part of an intron. In the SfiI digest the cp28 probe hybridized to seven DNA-fragments (six of which were detected also with Ie7) that were amplified in most of the lines. The same DNAfragments were present but not amplified in the control line TC13K. The presence of several hybridizing fragments also in the control line is probably due to homology within the P-glycoprotein gene family. Other amplified sequences were unique to each cell line and are presumably a result of so-called novel joints. The large number of new hybridizing fragments thus reflects a recombinational process during amplicon formation. The presence of specific cytogenetic markers in some of the cell lines indicated that the MDR cells were of monoclonal origin. Therefore, it is possible that each line contains a homogeneous population of DMs, each contributing the same complex pattern of novel fragments in the SfiI analysis. Another explanation of this complexity would be thai different amplicons (with different novel joints) are located on different DMs in a heterogeneous DM population.
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