No description available.

No description available.

No description available.

No description available.

No description available.

<p>Loss of chromosome 17p is frequently observed in various cancers. One of the most commonly mutated targets p53 is on chromosome 17p13.1. However, studies have also reported loss of the 17p13.2 region in breast and medulloblastoma, thereby suggesting the residence of potential tumour suppressors in 17p13.2. Cytochrome b5 domain containing 2 (CYB5D2) is located on 17p13.2 implying CYB5D2 being a candidate tumour suppressor. CYB5D2 (neuferricin) belongs to the family of membrane associated progesterone receptors (MAPR). The archetypal member of the family, progesterone receptor membrane component 1 (PGRMC1), has been shown to play a role in domains independently of its function in mediating progesterone signalling. Consistent with this, CYB5D2 was reported to promote neurogenesis and inhibit the proliferation of Neuro2a cells. However, its role in tumorigenesis remains unknown.</p> <p>To investigate the role of CYB5D2 in tumorigenesis, western blot analysis was performed on 20 matched clear cell renal cell carcinomas (ccRCC) and the adjacent non-tumour kidney (ANK) tissues; significant down-regulation of CYB5D2 was demonstrated in ccRCC in comparison to ANK tissues, an observation that was confirmed by immunohistochemistry (IHC) analysis of 9 pairs of ccRCC-ANK tissues. Ectopic expression of CYB5D2 inhibited the proliferation and the invasion of A498 ccRCC along with the inhibition of AKT activation. Collectively, the above results support the possibility of CYB5D2 being a potential tumour suppressor.</p> <p>In support of the results obtained in ccRCC, we were able to show a significant reduction of CYB5D2 in cervical squamous carcinoma compared to normal cervical tissues in our analysis of CYB5D2 expression in 35 cervical squamous tumours. In vitro, overexpression and knockdown of CYB5D2 inhibited and enhanced the invasion of HeLa cells, respectively. As a member of the MAPR family, CYB5D2 contains the signature motif of the family, the cytochrome b5 (cyt-b5) like heme/steroid binding domain. This domain is known for heme binding and research in our laboratory has shown the residue D86 being critical for heme association. Ssubstitution of D86 with G (D86G) abolished not only CYB5D2's ability to bind heme but also its capacity of inhibiting HeLa cell invasion. Taken together, we provide evidence that CYB5D2 possesses activities in suppressing tumorigenesis, at least for the tumorigenesis of ccRCC and cervical squamous carcinoma.</p> / Master of Science (MSc)

Yes / Cells encapsulation is a micro-technology widely applied in cell and tissue research, tissue transplantation, and regenerative medicine. In this paper, we proposed a growth of microtissue model for the human keratinocytes (HaCaT) cell line and an oral squamous cell carcinoma (OSCC) cell line (ORL-48) based on a simple aerosol microencapsulation technique. At an extrusion rate of 20 μL/min and air flow rate of 0.3 L/min programmed in the aerosol system, HaCaT and ORL-48 cells in alginate microcapsules were encapsulated in microcapsules with a diameter ranging from 200 to 300 μm. Both cell lines were successfully grown into microtissues in the microcapsules of alginate within 16 days of culture. The microtissues were characterized by using a live/dead cell viability assay, field emission-scanning electron microscopy (FE-SEM), fluorescence staining, and cell re-plating experiments. The microtissues of both cell types were viable after being extracted from the alginate membrane using alginate lyase. However, the microtissues of HaCaT and ORL-48 demonstrated differences in both nucleus size and morphology. The microtissues with re-associated cells in spheroids are potentially useful as a cell model for pharmacological studies. / Malaysia Ministry of Education (Fundamental Research Grant Scheme, FRGS Vot. 1482 and IGSP Vot. 679).

Yes / Background - Previous studies have demonstrated that a number of HOX genes, a family of transcription factors with key roles in early development, are up-regulated in head and neck squamous cell carcinoma (HNSCC) and other cancers. The loci of several Homeobox (HOX) genes also contain microRNAs (miRs), including miR-196a. Methods - Global miR expression and expression of all 39 HOX genes in normal oral keratinocytes (NOKs), oral pre-malignant (OPM) and HNSCC cells was assessed by expression microarray and qPCR and in tissues by immunohistochemistry (IHC) and qPCR of laser microdissected (LCM) tissues. Expression of miR196a and HOXB9 was reduced using anti-miR-196a and siRNA, respectively. Expression microarray profiles of anti-miR196a and pre-miR196a transfected cells were compared to parental cells in order to identify novel targets of miR- 196a. Putative miR196a targets were validated by qPCR and were confirmed as binding to the 3’UTR of miR196a by a dual luciferase reporter assay combined with mutational analysis of the miR-196a binding site. Results - miR-196a and HOXB9 are highly expressed in HNSCC compared to NOKs, a pattern also seen in HNSCC tissues by HOXB9 IHC and qPCR of miR-196a in LCM tissue. Knock-down of miR-196a expression decreased HNSCC cell migration, invasion and adhesion to fibronectin, but had no effect on proliferation. Furthermore, knock-down of HOXB9 expression decreased migration, invasion and proliferation but did not alter adhesion. We identified a novel primary mRNA transcript containing HOXB9 and miR196a-1 as predicted from in-silico analysis. Expression array analysis identified a number of miR196a targets, including MAMDC2 and HOXC8. We confirmed that MAMDC2 is a novel miR-196a target using a dual luciferase reporter assay with the effect abolished on mutation of the binding site. Conclusions - These results show that miR-196a and HOXB9 are overexpressed, perhaps co-ordinately, as HNSCC develops and exert a pro-tumourigenic phenotype in HNSCC and OPM cells.

Diss. (sammanfattning) Umeå : Univ., 2003. / Härtill 4 uppsatser.

Diss. (sammanfattning) Umeå : Univ., 2007. / Härtill 4 uppsatser.