Expression profiling of microdissected cell populations selected from basal cells in normal epidermis and basal cell carcinoma

Department of Genetics and Pathology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden.
British Journal of Dermatology (Impact Factor: 4.28). 04/2008; 158(3):527-38. DOI: 10.1111/j.1365-2133.2007.08418.x
Source: PubMed


Basal cell carcinomas (BCCs) are prevalent tumours with uniform histology that develop without any known precursor lesion. Alterations in the sonic hedgehog-patched1 signalling pathway are accepted as necessary events for tumorigenesis, and mutations in the patched1 gene are frequently present in tumours.
To analyse transcript profiles in BCC.
We used laser-assisted microdissection to isolate and collect cell populations defined under the microscope. Peripheral cells from nests of BCC were selected to represent tumour cells, and normal keratinocytes from epidermis basal layer were used as control. Extracted RNA was amplified and hybridized on to a cDNA microarray. Results Our results show that BCC cells express a transcript signature that is significantly different from that of normal keratinocytes, and over 350 genes with various functions were identified as differentially expressed. The compiled data suggest an upregulation of the Wnt signalling pathway as a major event in BCC cells. Furthermore, tumour cells appear to have an increased sensitivity to oxygen radicals and dysregulated genes involved in antigen presentation.
were validated at both the transcriptional level using real-time polymerase chain reaction and at the protein level using immunohistochemistry.
We show that microdissection in combination with robust strategies for RNA extraction, amplification and cDNA microarray analysis allow for reliable transcript profiling and that antibody-based proteomics provides an advantageous strategy for the analysis of corresponding differentially expressed proteins. We found that expression patterns were significantly altered in BCC cells compared with basal keratinocytes and that the Wnt signalling pathway was upregulated in tumour cells.

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    • "A study on laser microdissected breast tissue samples by Cowherd et al. in 2004 showed that the technical variability introduced by amplification and hybridisation experiments is smaller than the actual biological variation for different types of breast cancer tissues demonstrated with differential gene expression in these samples [6]. Samples for transcriptional profiling studies on epidermal basal cells, endometriosis tissue, and osteocytes were successfully collected with “Positioning and Ablation in Laser Microdissection” (PALM®) microbeam systems (PALM Microlaser Technologies GmbH) [7]. This technique grew in popularity as it allowed precise dissection of tissues under direct visualisation by a non-contact technique. "
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    BMC Ophthalmology 10/2013; 13(1):62. DOI:10.1186/1471-2415-13-62 · 1.02 Impact Factor
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    • "In some studies of mRNA authors identified genes whose expression was different in normal skin vs. basal cell tumors (Asplund et al. 2008; O'Driscoll et al. 2006), but the normal cell of origin with which BCC tissue should be compared is probably a hair follicle stem cell (Sellheyer 2011), and therefore these expression differences may not be specific to tumorigenesis. The ability to distinguish histopathologic subtypes was limited. "
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    • "The underlying assumption is that differences in mRNA levels are manifested in different phenotypes as a result of differences in protein levels. Accordingly, correlations between the differential expression of specific mRNAs and corresponding proteins have been found in numerous studies [1], many of which have been shown to have clear biological relevance [2,3]. Several studies have also found significant general correlations between RNA levels and protein levels [4-10], usually using data on RNA abundance acquired from platforms such as microarrays and Serial Analysis of Gene Expression (SAGE), in conjunction with data on the abundance of corresponding proteins derived from mass spectrometry (MS) analyses. "
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