| 1. |
- Tassidis, Helena, et al.
(författare)
-
Immunohistochemical detection of tyrosine phosphatase SHP-1 predicts outcome after radical prostatectomy for localized prostate cancer
- 2010
-
Ingår i: International Journal of Cancer. - : John Wiley & Sons. - 0020-7136 .- 1097-0215. ; 126:10, s. 2296-2307
-
Tidskriftsartikel (refereegranskat)abstract
- The protein tyrosine kinase (PTK) receptors and cytosolic signaling proteins as well as the protein tyrosine phosphatases (PTPs) have important roles in regulation of growth of the benign and malignant prostate gland. Here, we studied expression of the protein tyrosine phosphatase SHP-1 in prostate cancer cell lines and in human prostatic tissues. SHP-1 is expressed at a high level in LNCaP prostate cancer cells compared with PC3 cells. Silencing of SHP-1 expression with siRNA in LNCaP cells led to an increased rate of proliferation, whereas overexpression of SHP-1 by means of transient and stable transfection in PC3 cells led to a decrease in proliferation. Corresponding changes were observed in cyclin D1 expression. We further demonstrate that LNCaP and PC3 cells respond differently to IL-6 stimulation. SHP-1 overexpression in PC3 cells reversed IL-6 stimulation of proliferation, whereas in SHP-1-silenced LNCaP cells, IL-6 inhibition of proliferation was not affected. In addition, IL-6 treatment led to higher levels of phosphorylated STAT3 in SHP-1-silenced LNCaP cells than in control cells. Next, SHP-1 expression in human prostate cancer was analyzed by immunohistochemical staining of tissue microarrays comprising tumor specimens from 100 prostate cancer patients. We found an inverse correlation between the tumor level of SHP-1 expression and time to biochemical recurrence and clinical progression among prostate cancer patients. In conclusion, our results suggest that a decreased level of SHP-1 expression in prostate cancer cells is associated with a high proliferation rate and an increased risk of recurrence or clinical progression after radical prostatectomy for localized prostate cancer.
|
|
| 2. |
- Stanezai, S., et al.
(författare)
-
Higher intensity of Low Molecular Weight Protein Tyrosine Phosphatase/ ACP-1 in survivors of patients diagnosed with Diffuse Large B Cell Lymphoma (DLBCL) compared to non-survivors
- 2016
-
Ingår i: Austin Biology. - : Austin Publishing. ; 1:2
-
Tidskriftsartikel (refereegranskat)abstract
- Adult Diffuse Large B Cell Lymphoma (DLBCL) is a heterogeneous form of hematopoietic cancer and difficult to treat. In order to find a better diagnostic indication for the disease, we analyzed Low Molecular Weight Protein Tyrosine Phosphatase (LMWPTP) that in humans is encoded by the ACP1 gene. LMWPTP is an enzyme shown to counteract Protein Tyrosine Kinases (PTK) and was suggested to be a negative growth factor regulator. However, the 18 kDa PTP can also have a positive effect on cell growth and proliferation, indicating a controversial role in the tumorigenic process. LMWPTP exists in different isoforms which are electrophoretically, kinetically and immunologically distinct. We have studied two subgroups of DLBCL consisting of a Germinal Center B cell like (GCB) and a non-Germinal Center B cell like (non-GCB) group. The two subgroups have been defined by gene-expressing profiling and are associated with differential outcome. The expression levels of LMWPTP protein was compared and showed significant differences between the GCB and non- GCB subgroups (p=0.012). Interestingly, when the samples were divided into survivors and non-survivors, and thereafter analyzed for LMWPTP expression, the samples from patients with a higher survival rate showed increased staining intensity, whereas the samples from patients with lower intensity of LMWPTP did not survive the disease (p=0.001). In conclusion, we have shown that DLBCL patients with worse outcome express LMWPTP with a lower intensity, suggesting a tumor suppressor role for this form of the enzyme.
|
|
| 3. |
- El-Schich, Zahra, et al.
(författare)
-
Interfacing antibody-based microarrays and digital holography enables label-free detection for loss of cell volume
- 2015
-
Ingår i: Future Science OA. - : Future Science Group. - 2056-5623. ; 1:3
-
Tidskriftsartikel (refereegranskat)abstract
- Background: We introduce the combination of digital holographic microscopy (DHM) and antibody microarrays as a powerful tool to measure morphological changes in specifically antibody-captured cells. The aim of the study was to develop DHM for analysis of cell death of etoposide-treated suspension cells. Result/Methodology: We demonstrate that the cell number, mean area, thickness, and volume were non-invasively measured by using DHM. The cell number was stable over time, but the two cell lines showed changes of cell area and cell irregularity after treatment. The cell volume in etoposide-treated cells was decreased, whereas untreated cells showed stable volume. Conclusions: Our results provide proof of concept for using DHM combined with antibody-based microarray technology for detecting morphological changes in captured cells.
|
|
| 4. |
- Alm, Kersti, et al.
(författare)
-
Cells and holograms : holograms and digital holographic microscopy as a tool to study the morphology of living cells
- 2013
-
Ingår i: Holography. - : INTECH. - 9789535111177 ; , s. 335-351
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- We present a method to study the morphology of living, dividing and dying cells using DHM. DHM is a non-invasive, non-destructive and non-phototoxic method which allows the user to perform both qualitative and quantitative measurements of living cells over time. We show here our results on cell division and cell death in single cells. The morphological analyses performed here show changes caused by cell death and cell division, and indicate the possibilities to discriminate between different types of cell death. Cells dying in an apoptosis-like manner display different cell area and cell thickness profiles over time compared to cells dying in a necrosis-like manner, although their volume profiles are very similar. Dividing cells show a characteristic dip in the volume profile, which makes them easily distinguishable. Also, several previous studies show the versatile abilities of DHM. Different cell types have been studied and the morphology has been used to determine cell functionality as well as changes in morphology related to the environment. Cell morphology parameters can be very useful when following the effects of different treatments, the process of differentiation as well as cell growth and cell death. Cell morphology studied by DHM can be useful in toxicology, stem cell and cancer research.
|
|
| 5. |
- Alm, Kersti, et al.
(författare)
-
Digital holography and cell studies
- 2011
-
Ingår i: Holography, Research and Technologies. - : DKV - Deutscher Kälte- und Klimatechnischer Verein. - 9789533072272 ; , s. 237-252
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Digital holography microscopy (DHM) has developed into a broad field, and one of all the interesting applications is to study cells without staining, labeling or in any other way affecting them. Both fixed and living, dying or dead cells can be studied. The first DHM images showing living cells were published in 2004 and 2005 (Carl et al. 2004, Marquet et al. 2005), making this field of research rather new. Digital holography makes it possible to easily measure cell properties that previously have been very difficult to study, such as cell thickness and volume (Marquet et al. 2005, Mölder et al. 2008). Two of the major advantages of DHM is the 3-D imaging possibility and measurements over time. Digital holography has ben used to study several types of cells, such as nerve cells, red blood cells, stem cells and cancer cells (Emery et al. 2007, Kemper et al. 2006, Langehanenberg et al. 2009) . It has also been applied for studies of cell proliferation, cell movement, sub-cellular structures and cell morphology (Kemper et al. 2009, Yu et al. 2009). Both 2-D and 3-D cell movement can be determined ( Langehanenberg et al. 2009). Even cell viability status can be determined using DHM. Interestingly, it is possible to study both single cells and entire populations simultaneously, allowing for very nuanced studies. Older, well known techniques often require some degree of cell disturbance such as the fluorescent antibody labeling required for fluorescense or confocal microscopy studies. In this paper we will present some of the studies made possible by DHM. We will compare DHM with previously used techniques and discuss the benefits and drawbacks of digital holography cell measurements.
|
|
| 6. |
- Alonso, A, et al.
(författare)
-
VHY, a novel myristoylated testis-restricted dual specificity protein phosphatase related to VHX
- 2004
-
Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 279:31, s. 32586-32591
-
Tidskriftsartikel (refereegranskat)abstract
- The human DUSP15 gene encodes an uncharacterized 235-amino acid member of the subfamily of small dual specificity protein phosphatases related to the Vaccinia virus VH1 phosphatase. Similar to VHR-related MKPX (VHX) (DUSP22), the predicted protein has an N-terminal myristoylation recognition sequence, and we show here that both are indeed modified by the attachment of a myristate to Gly-2. In recognition of this relatedness to VHX, we refer to the DUSP15-encoded protein as VH1-related member Y (VHY). We report that VHY is expressed at high levels in the testis and barely detectable levels in the brain, spinal cord, and thyroid. A VHY-specific antiserum detected a protein with an apparent molecular mass of 26 kDa, and histochemical analysis showed that VHY was readily detectable in pachytene spermatocytes (midstage of meiotic division I) and round spermatids and weakly in Leydig cells ( somatic cells outside of the seminiferous tubules). When expressed in 293T or NIH-3T3 cells, VHY was concentrated at the plasma membrane with some staining of vesicular structures in the Golgi region. Mutation of the myristoylation site Gly-2 abrogated membrane location. Finally, we demonstrate that VHY is an active phosphatase in vitro. We conclude that VHY is a new member of a subgroup of myristoylated VH1-like small dual specificity phosphatases.
|
|
| 7. |
|
|
| 8. |
- Bergh, Ann-Charlotte, et al.
(författare)
-
B cell receptor signaling suppressor SHP-1 is active in CLL lymph node and peripheral blood
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Protein tyrosine phosphatase SHP-1 expression and activity is downregulated or lost in several leukemias and lymphomas due to DNA promotor hypermethylation, catalytic site mutation or oxidation, or phosphorylation at inhibitory sites, implying a negative role of SHP-1 in development of leukemias/lymphomas. In chronic lymphocytic leukemia (CLL), B cell receptor (BcR) and microenvironment signal levels are important in the pathogenesis. Considering that SHP-1 is a BcR signaling suppressor, we hypothesized that SHP-1 would be down-regulated and/or inactivated in the proliferative center lymph node (LN) cells. We analyzed PTPN6 (SHP-1) gene expression, SHP-1 protein expression and phosphorylation status in matched CD5+/CD19+ peripheral blood (PB) and LN cells from 6 CLL patients, and in comparison, BcR (anti-IgM) in vitro triggered CLL PB cells from 10 patients. Gene expression of PTPN6 was significantly higher in PB compared to LN CLL cells in 50% of the cases. SHP-1 protein expression level and phosphorylation at SHP-1Y536 and SHP-1S591 were, however, equal in PB and LN samples. SHP-1 phosphorylation at Y536 and S591, in PB CLL cells cultured ex vivo was significantly reduced upon BcR engagement in all patient samples. These results indicate that in vivo BcR signaling in CLL is paralyzed.
|
|
| 9. |
|
|
| 10. |
- Beyer, Sarah, 1982-, et al.
(författare)
-
Fluorescent Molecularly Imprinted Polymer Layers against Sialic Acid on Silica-Coated Polystyrene Cores — Assessment of the Binding Behavior to Cancer Cells
- 2022
-
Ingår i: Cancers. - : MDPI. - 2072-6694. ; 14:8
-
Tidskriftsartikel (refereegranskat)abstract
- Sialic acid (SA) is a monosaccharide usually linked to the terminus of glycan chains on the cell surface. It plays a crucial role in many biological processes, and hypersialylation is a common feature in cancer. Lectins are widely used to analyze the cell surface expression of SA. However, these protein molecules are usually expensive and easily denatured, which calls for the development of alternative glycan-specific receptors and cell imaging technologies. In this study, SA-imprinted fluorescent core-shell molecularly imprinted polymer particles (SA-MIPs) were employed to recognize SA on the cell surface of cancer cell lines. The SA-MIPs improved suspensibility and scattering properties compared with previously used core-shell SA-MIPs. Although SA-imprinting was performed using SA without preference for the α2,3-and α2,6-SA forms, we screened the cancer cell lines analyzed using the lectins Maackia Amurensis Lectin I (MAL I, α2,3-SA) and Sambucus Nigra Lectin (SNA, α2,6-SA). Our results show that the selected cancer cell lines in this study presented a varied binding behavior with the SA-MIPs. The binding pattern of the lectins was also demonstrated. Moreover, two different pentavalent SA conjugates were used to inhibit the binding of the SA-MIPs to breast, skin, and lung cancer cell lines, demonstrating the specificity of the SA-MIPs in both flow cytometry and confocal fluorescence microscopy. We concluded that the synthesized SA-MIPs might be a powerful future tool in the diagnostic analysis of various cancer cells.
|
|
