Itary exons, rather than the profile of all ASPs. Other studies do analyse the co-expression of two or more variable exons [27,28], although not as a part of the ASP. In an alternative splice pattern, many different isoforms are present. The functional importance of any single variable exon may be dependent on the full expression pattern. Detecting the presence of a single, or multiple variable exons across all of these isoforms does not provide any information as to where these variable exons are expressed, and crucially what other variable exons are present alongside. On the other hand, the presence of additional variable exons on a particular isoform may actually change or not permit the function of the variable exon in question, and thus without knowing the entire alternative splice pattern, this restricts what one can say about detecting the presence of a single variable exon in these studies. For the same reason even the `co-expression’ of two exons proven by immunohistochemistry [5,17] does not mean that they are on the same molecule as the presence of two or more different CD44 isoforms in the same cell at the same time is also possible. Although the expression level changes of one variable exon might still show a correlation with the progression in one tumour type, there is no such CAL-120 site obvious example in the literature as there are lots of contradictions even during the examination of the same tumour type. Some more recent studies have analyzed the role of CD44v isoforms rather than single exons in tumour progression [29,30], but not as a part of a complex, finely regulated pattern. A more holistic view of the alternative 24272870 splice event is needed to examine the role of CD44 variants. This would be a huge practical challenge from tumour to tumour. We have sought to establish a reliable and reproducible method to examine this pattern and its possible tumour and/or progression specificity, since co-expression of exons proven by immunohistochanistry does not determine whether they are on the same molecule (and two or more CD44 may be present in the same cell at the same time) We have used a PCR based method using five primer pairs to create a simple representation of this highly NT 157 site complex CD44 expression pattern.glutamine, 0.1 mM non-essential amino acids, 1 mM sodium pyruvate, and 50 mg/ml gentamicin sulfate (all from Gibco BRL, Life Technologies, Paisley, Scotland). The melanocytes were maintained in Melanocyte Growth Medium M2 (PromoCell), the keratinocytes in Keratinocyte Media 2 (PromoCell) and the fibroblasts in Fibroblast Media (PromoCell).RT-PCR Analysis of CD44 mRNA ExpressionTotal RNA was isolated from the frozen homogenized tumour samples and cell cultures from the in vivo experiments using TRI ReagentTM (SigmaH) according to the manufacturer instructions. Possible DNA contamination was eliminated using TURBO DNA-freeTM kit (AmbionH). For reverse transcription 1 ml of 10 mM dNTP mix (Finnzymes, Espoo, Finland) and 1 ml of random primer-oligo dT were mixed for a final concentration of 2.5 mM and used with 2 mg of purified total RNA. After incubating at 70uC for 10 min, 1 ml of M-MLV reverse transcriptase (200 units/ml), 2 ml of 10x M-MLV RT Buffer (both from Sigma), 0.5 ml RNase Inhibitor (40 units/ml, Promega, Madison WI) and 6.5 ml DEPC treated water was added for 20 ml final volume and incubated at 37uC for 50 min and then at 85uC for 10 min. The occurrence of reverse transcription was checked by polymerase chain reaction with.Itary exons, rather than the profile of all ASPs. Other studies do analyse the co-expression of two or more variable exons [27,28], although not as a part of the ASP. In an alternative splice pattern, many different isoforms are present. The functional importance of any single variable exon may be dependent on the full expression pattern. Detecting the presence of a single, or multiple variable exons across all of these isoforms does not provide any information as to where these variable exons are expressed, and crucially what other variable exons are present alongside. On the other hand, the presence of additional variable exons on a particular isoform may actually change or not permit the function of the variable exon in question, and thus without knowing the entire alternative splice pattern, this restricts what one can say about detecting the presence of a single variable exon in these studies. For the same reason even the `co-expression’ of two exons proven by immunohistochemistry [5,17] does not mean that they are on the same molecule as the presence of two or more different CD44 isoforms in the same cell at the same time is also possible. Although the expression level changes of one variable exon might still show a correlation with the progression in one tumour type, there is no such obvious example in the literature as there are lots of contradictions even during the examination of the same tumour type. Some more recent studies have analyzed the role of CD44v isoforms rather than single exons in tumour progression [29,30], but not as a part of a complex, finely regulated pattern. A more holistic view of the alternative 24272870 splice event is needed to examine the role of CD44 variants. This would be a huge practical challenge from tumour to tumour. We have sought to establish a reliable and reproducible method to examine this pattern and its possible tumour and/or progression specificity, since co-expression of exons proven by immunohistochanistry does not determine whether they are on the same molecule (and two or more CD44 may be present in the same cell at the same time) We have used a PCR based method using five primer pairs to create a simple representation of this highly complex CD44 expression pattern.glutamine, 0.1 mM non-essential amino acids, 1 mM sodium pyruvate, and 50 mg/ml gentamicin sulfate (all from Gibco BRL, Life Technologies, Paisley, Scotland). The melanocytes were maintained in Melanocyte Growth Medium M2 (PromoCell), the keratinocytes in Keratinocyte Media 2 (PromoCell) and the fibroblasts in Fibroblast Media (PromoCell).RT-PCR Analysis of CD44 mRNA ExpressionTotal RNA was isolated from the frozen homogenized tumour samples and cell cultures from the in vivo experiments using TRI ReagentTM (SigmaH) according to the manufacturer instructions. Possible DNA contamination was eliminated using TURBO DNA-freeTM kit (AmbionH). For reverse transcription 1 ml of 10 mM dNTP mix (Finnzymes, Espoo, Finland) and 1 ml of random primer-oligo dT were mixed for a final concentration of 2.5 mM and used with 2 mg of purified total RNA. After incubating at 70uC for 10 min, 1 ml of M-MLV reverse transcriptase (200 units/ml), 2 ml of 10x M-MLV RT Buffer (both from Sigma), 0.5 ml RNase Inhibitor (40 units/ml, Promega, Madison WI) and 6.5 ml DEPC treated water was added for 20 ml final volume and incubated at 37uC for 50 min and then at 85uC for 10 min. The occurrence of reverse transcription was checked by polymerase chain reaction with.
