ABSTRACT
A novel transmembrane-glycoprotein, referred to as UKW, was identified by expression profiling of a metastatic versus a non-metastatic pancreatic carcinoma cell line (S2-007 and S2-028). UKW is strongly expressed only in the metastatic cell line. The corresponding cDNA encodes for a protein of 374 amino acids. UKW is located on chromosome 11q24.1, a locus which is frequently amplified in pancreatic cancer. Bioinformatic analysis revealed that UKW corresponds to a putative transmembrane-glycoprotein composed of an extracellular domain of 215 aa containing two C2-type Ig folds, a transmembrane region of 23 aa and a highly acidic cytoplasmic region of 117 aa. Sequence alignment revealed homology with human, murine and zebrafish coxsackievirus and adenovirus receptor of 35%, 33% and 36% and colon-related A33 antigen of 32%, respectively. Murine adipose-specific protein 5 (Asp-5), however, exhibited the closest homology (93%), suggesting that UKW represents the human orthologue of Asp-5. Multiple tissue expression array analysis revealed UKW expression in gastrointestinal tissues, brain, aorta and uterus and absence in most other human tissues. In a panel of invasive and noninvasive mammary carcinoma cell lines, relative overexpression of UKW was observed in the invasive cell lines. In addition, increased expression of UKW mRNA was found in pancreatic adenocarcinoma compared to tissues derived from patients with chronic pancreatitis and normal pancreatic tissue.
ABSTRACT
Using Affymetrix GeneChip® arrays, we have established the transcriptional profiles of two sublines of the human pancreatic adenocarcinoma cell lines SUIT-2, S2-007 (metastatic) and S2-028 (non-metastatic). By comparison of ESTs corresponding to differentially regulated mRNAs, we have identified the putative dual-specificity kinase LKW as down-regulated in the metastatic cell line S2-007. LKW is composed of 358 amino acids and contains catalytic domains corresponding to those of Ser/Thr- and Tyr-kinases. The gene encoding LKW consists of four exons separated by three introns and is located on chromosome 20p12.2-p13. In parallel LKW has been identified in different experimental settings by other groups and is referred to as NIPK, SKIP3 and TRB3. We noticed that the metastatic propensity of two additional pancreatic cellular systems correlates with the down-regulation of mRNA levels corresponding to LKW. Evaluation of a panel of mammary carcinoma cell lines scored as non-invasive and invasive based on an in vitro invasion assay indicated down-regulation of LKW mRNA levels in the invasive cell lines. mRNA for LKW was shown to be overexpressed in pancreatic carcinomas compared to normal pancreas and tissues derived from patients with chronic pancreatitis as well as in colon, kidney, breast and ovarian carcinomas compared to their matching normal tissues. Analysis of colorectal carcinomas covering Duke's stages A, B, C and D revealed down-regulation of LKW mRNA in specimens corresponding to Duke's stages C and D, representing invasive and metastatic stages compared to the less invasive stages corresponding to Duke's stages A and B. Our results indicate that down-regulation of mRNA encoding LKW correlates with an invasive status of mammary carcinoma cell lines and the metastatic propensity of colorectal carcinoma.
ABSTRACT
In order to identify metastasis-associated and promoting genes of pancreatic carcinoma we investigated the transcriptional profile of rat pancreatic carcinoma cell lines BSp73-AS (non-metastatic) and BSp73-ASML (highly metastatic) with Affymetrix GeneChip Array technology. We analyzed the expression profile of 7000 genes. Two hundred and ten genes (3%) were up-regulated and 247 genes (3.5%) were down-regulated in the metastatic cell line based on a fold change of expression of at least 3 and a change factor quality of > or = 2. In order to classify the de-regulated genes we defined the following categories: proteases and protease-related genes, cytokines, receptor tyrosine kinases, other transmembrane proteins/receptors, transcription, cell cycle/apoptosis, signaling, adhesion/extracellular matrix, metabolism, detoxification, protein modification, trafficking, immune response and other genes. We identified de-regulated AP1, FRA-1 and c-myc-mediated transcription in cell line BSp73-ASML. Up-regulation of transmembrane tyrosine kinase receptors c-met, IGFR1, IGFR2 and EGFR family-related ligands such as HB-EGF, TGFa, amphiregulin and neuregulin as well as c-met ligand HGF point to a possible role of this system in metastasis. We identified 56 non-tyrosine kinase transmembrane receptors as new target candidates for inhibition of metastasis, four of them representing already validated targets. In addition, we identified MMP9, uPA, uPAR, cyclin D1 and S100A4 (mts1) as possible contributors of the metastatic phenotype.
