Following androgen ablation treatment for advanced prostate cancer, almost all men relapse after a period of initial response to therapy, which eventually is life threatening. We have previously found that purine-rich element binding protein, PUR alpha, was significantly repressed in androgen-independent prostate cancer cell lines in comparison to an androgen-dependent line. Moreover, over-expressing PURa in androgen-independent prostate cancer cells attenuated their cell proliferation. The aim of the studies described here was to uncover some of the mechanisms by which over-expression of PURa attenuates cell proliferation.
Purine-rich element binding protein (PUR) alpha induces endoplasmic reticulum stress response, and cell differentiation pathways in prostate cancer cells.
No sample metadata fields
View SamplesCell adhesion in plants is mediated predominantly by pectins, a group of complex cell wall associated polysaccharides. An Arabidopsis mutant, friable1 (frb1), was identified through a screen of T-DNA insertion lines that exhibited defective cell adhesion. Interestingly, the frb1 plants displayed both cell and organ dissociations and also ectopic organ fusions. The FRB1 gene encodes a Golgi-localized, plant specific protein with only weak sequence similarities to known proteins (DUF246). Unlike other cell adhesion deficient mutants, frb1 mutants do not have reduced levels of adhesion related cell wall polymers, such as pectins. Instead, FRB1 affects the abundance of galactose- and arabinose-containing oligosaccharides in the Golgi. Furthermore, frb1 mutants displayed alteration in pectin methylesterification, cell wall associated extensins and xyloglucan microstructure. We propose that abnormal FRB1 action has pleiotropic consequences on wall architecture, affecting both the extensin and pectin matrices, with consequent changes to the biomechanical properties of the wall and middle lamella, thereby influencing cell-cell adhesion.
The FRIABLE1 gene product affects cell adhesion in Arabidopsis.
Specimen part
View SamplesBackground: The KRAS gene is mutated in about 40% of colorectal cancer (CRC) cases, which has been clinically validated as a predictive mutational marker of intrinsic resistatnce to anti-EGFR inhibitor (EGFRi) therapy. Since nearly 60% of patients with a wild type KRAS fail to respond to EGFRi treatment, there is a need to develop more reliable molecular signatures to better predict response. Here we address the challenge of adapting a gene expression signature predictive of RAS pathway activation, created using fresh frozen (FF) tissues, for use with more widely available formalin fixed paraffin-embedded (FFPE) tissues. Methods: In this study, we evaluated the translation of an 18-gene RAS pathway signature score from FF to FFPE in 54 CRC cases, using a head-to-head comparison of five technology platforms. FFPE-based technologies included the Affymetrix GeneChip (Affy), NanoString nCounter(NanoS), Illumina whole genome RNASeq (RNA-Acc), Illumina targeted RNASeq(t-RNA), and Illumina stranded Total RNA-rRNA-depletion (rRNA). Results: Using Affy_FF as the "gold" standard, initial analysis of the 18-gene RAS scores on all 54 samples shows varying pairwise Spearman correlations, with (1) Affy_FFPE(r=0.233, p=0.090); (2) NanoS_FFPE(r=0.608, p<0.0001); (3) RNA-Acc_FFPE(r=0.175, p=0.21); (4) t-RNA_FFPE (r=-0.237, p=0.085); and (5) t-RNA (r=-0.012, p=0.93). These results suggest that only NanoString has successful FF to FFPE translation. The subsequent removal of identified "problematic" samples (n=15) and gene (n=2) further improves the correlations of Affy_FF with three of the five technologies: Affy_FFPE (r=0.672, p<0.0001); NanoS_FFPE (r=0.738, p<0.0001); and RNA-Acc_FFPE (r=0.483, p=0.002). Conclusions: Of the five technology platforms tested, NanoString technology provides a more faithful translation of the RAS pathway gene expression signature from FF to FFPE than the Affymetrix GeneChip and multiple RNASeq technologies. Moreover, NanoString was the most forgiving technology in the analysis of samples with presumably poor RNA quality. Using this approach, the RAS signature score may now be reasonably applied to FFPE clinical samples. Overall design: Fifty-four (54) FFPE evaluable tumor specimens were selected from a larger multi-center cohort of 468 well-characterized colorectal adenocarcinoma patients whose tissues were obtained between October 2006 and September 2010 at the University of South Florida. The sample cohort was composed of tumor samples that were available as matched fresh-frozen (FF) and formalin-fixed paraffin-embedded (FFPE) pairs.
Adaptation of a RAS pathway activation signature from FF to FFPE tissues in colorectal cancer.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Complementary strand microRNAs mediate acquisition of metastatic potential in colonic adenocarcinoma.
Sex
View SamplesCompariosn of mRNA and miRNA profile in colon cancer
Complementary strand microRNAs mediate acquisition of metastatic potential in colonic adenocarcinoma.
Sex
View SamplesAnalysis of 143 completely histologically-normal breast tissues resulted in the identification of a malignancy risk gene signature that may serve as a marker of subsequent risk of breast cancer development.
Proliferative genes dominate malignancy-risk gene signature in histologically-normal breast tissue.
No sample metadata fields
View SamplesSamples were taken from colorectal cancers in surgically resected specimens in 155 colorectal cancer patients. The expression profiles were determined using Affymetrix Human Genome U133Plus 2.0 arrays. Our MSI/MSS classifier was applied to these samples.
DNA copy-number alterations underlie gene expression differences between microsatellite stable and unstable colorectal cancers.
No sample metadata fields
View SamplesSamples were taken from colorectal cancers in surgically resected specimens from 74 patients. The expression profiles were determined using Affymetrix Human Genome U133Plus 2.0 arrays. Our MSI/MSS classifer was applied to these samples.
DNA copy-number alterations underlie gene expression differences between microsatellite stable and unstable colorectal cancers.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Three-dimensional culture system identifies a new mode of cetuximab resistance and disease-relevant genes in colorectal cancer.
Specimen part, Cell line
View SamplesIt is increasingly appreciated that properties of cultured epithelial cells differ dramatically in 2D compared to 3D, and the latter more faithfully recapitulates in vivo behavior. By studying a battery of human colorectal cancer (CRC) cell lines in type-1 collagen, we have found that HCA-7 cells form colonies with two distinctive and persistent morphological and functional properties. We observed predominantly single-layered polarized cysts (cystic colonies, CC) and a smaller fraction displaying disorganized solid masses (spiky colonies, SC) that were highly invasive in vivo. Despite overall genomic similarity, CC and SC exhibited distinct and dynamic patterns of gene expression in 3D.
Three-dimensional culture system identifies a new mode of cetuximab resistance and disease-relevant genes in colorectal cancer.
Specimen part, Cell line
View Samples