Gene expression data of locally advanced rectal cancer patients by KRAS status
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE170999 | GEO | 2021/03/29
REPOSITORIES: GEO
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Project description:Gene expression data of locally advanced rectal cancer patients by KRAS status
| PRJNA718067 | ENA
Project description:Locally advanced rectal cancer characterized by multiplex kinase activity profiling
2010-08-05 | E-TABM-913 | biostudies-arrayexpress
Project description:Mutations of the KRAS oncogene are predictive for resistance to treatment with antibodies against the epithelial growth factor receptor in patients with colorectal cancer. Overcoming this therapeutic dilemma could potentially be achieved by the introduction of drugs that inhibit signaling pathways that are activated by KRAS mutations. To comprehensively identify such signaling pathways we profiled pretreatment biopsies from 65 patients with locally advanced rectal cancer – 30 of which carried mutated KRAS - using global gene expression microarrays. By comparing all tumor tissues exclusively to matched normal mucosa, we could improve assay sensitivity, and identified a total of 22,297 features that were differentially expressed (adjusted p-value p<0.05) between normal mucosa and cancer, including several novel potential rectal cancer genes. We then used this comprehensive description of the rectal cancer transcriptome as the baseline for identifying KRAS-dependent alterations. The presence of activating KRAS mutations resulted in significant upregulation of 13 genes (adjusted p-value < 0.05), among them DUSP4, a MAP-kinase phosphatase, and SMYD3, a histone methyltransferase. Inhibition of the expression of both genes has been achieved therapeutically with the MEK1-inhibitor PD98059 and the antibacterial compound Novobiocin, respectively, suggesting a potential approach to overcome resistance to treatment with antibodies against the epithelial growth factor receptor in patients with KRAS-mutant rectal carcinomas. Paired samples of tumor and mucosa from a total of 65 patients, i.e. 130 arrays
2011-03-11 | E-GEOD-20842 | biostudies-arrayexpress
Project description:Mutations of the KRAS oncogene are predictive for resistance to treatment with antibodies against the epithelial growth factor receptor in patients with colorectal cancer. Overcoming this therapeutic dilemma could potentially be achieved by the introduction of drugs that inhibit signaling pathways that are activated by KRAS mutations. To comprehensively identify such signaling pathways we profiled pretreatment biopsies from 65 patients with locally advanced rectal cancer – 30 of which carried mutated KRAS - using global gene expression microarrays. By comparing all tumor tissues exclusively to matched normal mucosa, we could improve assay sensitivity, and identified a total of 22,297 features that were differentially expressed (adjusted p-value p<0.05) between normal mucosa and cancer, including several novel potential rectal cancer genes. We then used this comprehensive description of the rectal cancer transcriptome as the baseline for identifying KRAS-dependent alterations. The presence of activating KRAS mutations resulted in significant upregulation of 13 genes (adjusted p-value < 0.05), among them DUSP4, a MAP-kinase phosphatase, and SMYD3, a histone methyltransferase. Inhibition of the expression of both genes has been achieved therapeutically with the MEK1-inhibitor PD98059 and the antibacterial compound Novobiocin, respectively, suggesting a potential approach to overcome resistance to treatment with antibodies against the epithelial growth factor receptor in patients with KRAS-mutant rectal carcinomas.
2011-03-11 | GSE20842 | GEO
Project description:Understanding transcriptional changes in locally advanced rectal cancer which are therapy-related and dependent upon tumour regression will drive stratified medicine in the rectal cancer paradigm
2018-11-01 | GSE94104 | GEO
Project description:locally advanced rectal cancer (LARC) patients were sorted according to their radio-responsiveness. Patients were categorized into two groups—complete response (n = 3) and poor response (n = 3)—based on the tumor regression grade. Expression profiles for each group were obtained using RNA-seq on a HiSeq 4000 system (Illumina).
2023-03-01 | GSE226034 | GEO
Project description:The study objective was to find new biomarkers of treatment response and adverse events in patients receiving neoadjuvant therapy for locally advanced rectal cancer. Patients received neoadjuvant chemotherapy (NACT) followed by chemoradiotherapy (CRT) and underwent treatment evaluation four weeks after CRT completion. Radical pelvic surgery was planned 2-4 weeks later. Patients were scored for treatment adverse events, according to Common Terminology Criteria for Adverse Events (CTCAE) version 3.0, throughout the neoadjuvant treatment course, including at NACT and CRT completion. Treatment response was assessed by histologic ypTN staging and tumor regression grade (TRG) scoring, as well as progression-free survival (time from Inclusion date to Date of local relapse or Date of metastatic disease, whichever came first) recorded for five years after surgery.
2016-04-21 | GSE65622 | GEO
Project description:Samples were prospectively collected during colonoscopic examination from 46 rectal cancer patients before starting preoperative chemoradiotherapy. The expression profiles were determined using Affymetrix Human Genome U133 Plus 2.0 arrays. Comparison between the sample groups allow to identify a set of discriminating genes that can be used for prediction of the response to radiotherapy in rectal cancer. Specimens from 46 rectal cancer patients who approved to receive preoperative chemoradiotherapy were studied. We prospectively collected biopsy specimens during colonoscopic examination from rectal cancer before starting preoperative chemoradiotherapy. Specimens from tumors were snap-frozen in liquid nitrogen and stored at -80 C until use. Paralleled tumor specimens were formalin fixed and paraffin embedded for histologic examination and other specimens were used for RNA extraction. RNA was extracted from tumor tissue using frozen samples. The patients provided written, informed consent to the collection of specimens, and the local Ethics Committee approved the study protocol. All patients received a total dose of 50.4 Gy of radiation, UFT(300-500mg/day) and LV (75mg/day) and underwent standardized curative resection, following an interval of 4 weeks after chemoradiotherapy.
2013-01-29 | E-GEOD-35452 | biostudies-arrayexpress
Project description:Most patients with locally advanced rectal cancer (LARC) present incomplete pathological response (pIR) to neoadjuvant chemoradiotherapy (nCRT). Despite the efforts to predict treatment response using tumor-molecular features, as differentially expressed genes, no molecule has proved to be a strong biomarker. The tumor secretome analysis is a promising strategy for biomarkers identification, which can be assessed using transcriptomic data. Here, we performed transcriptomic-based secretome analysis to select potentially secreted proteins using an in silico approach. The tumor expression profile of 28 LARC biopsies carefully selected and collected before nCRT was compared with normal rectal tissues (NT). The expression profile showed no significant differences between cases with complete (pCR) and incomplete response to nCRT. Genes with increased expression (pCR = 106 and pIR = 357) were used for secretome analysis based on public databases (Vesiclepedia, Human Cancer Secretome Database and Plasma and Proteome Database). Seventeen potentially secreted candidates (pCR=1, pIR=13 and 3 in both groups) were further investigated in two independent datasets (TCGA and GSE68204) confirming their over-expression in LARC. The potential secreted biomarkers were also confirmed as associated with the nCRT response (GSE68204). These putative proteins are candidates to be assessed in liquid biopsies aiming a personalized treatment in LARC patients.
2019-07-01 | GSE123390 | GEO
Project description:Background: MicroRNAs (miRNAs) are small, non-coding, RNA molecules which regulate numerous cellular processes. Specific miRNA may be abnormally down-regulated or up-regulated in colorectal cancer and have been found associated with prognosis or response to treatments. However, no study has ever addressed their predictive role in rectal cancer. Therefore, we used microarray technology and RT-PCR to profile miRNA expression patterns in patients (pts) with rectal cancer, with the aim to identify a specific M-bM-^@M-^\signatureM-bM-^@M-^] associated with pathological complete response after neoadjuvant chemo-radiotherapy. Methods: 38 pts with locally advanced rectal cancer (cT3-4/N+) were treated with capecitabine-oxaliplatin and pelvic conformal radiotherapy (45 cGy) followed by surgery (after 6-8 weeks). Pathologic response was scored according to the tumor regression grade (TRG) scale. MiRNA expression profile was analysed by microarray on fresh frozen biopsies obtained before treatment start and confirmed by RT-PCR. The correlation between miRNA expression profile and the TRG coded as TRG1 (pathologic Complete Response-pCR) versus TRG >1 (no pCR) was assessed by statistical analysis methods specifically designed for this study. Findings: 14 miRNAs were selected by arrays analysis as differentially expressed in TRG1 pts and 13 were confirmed by RT-PCR. In particular, 11 miRNAs (miR-1183, miR-483-5p, miR-622, miR-125a-3p, miR-1224-5p, miR-188-5p, miR-1471, miR-671-5p, miR-1909*, miR-630 and miR-765) were significantly up-regulated in TRG1 pts, while 2 miRNAs were under -expressed (miR-1274b and miR-720). miR-622 and miR-630 showed 100% sensitivity and specificity in selecting TRG1 cases and were significantly correlated with EGFR (M-OM-^G2=11M-bM-^@M-"793; p= 0M-bM-^@M-"001) and TS expression (M-OM-^G2=10M-bM-^@M-"589; p= 0M-bM-^@M-"001). Interpretation: A set of 13 miRNAs is strongly associated with pathologic complete response and may represent a specific marker of response to chemo-radiotherapy in locally advanced rectal cancer. Experiments were performed on purified RNA from preoperatory biopsies of 38 patients with histological diagnosis of rectal adenocarcinoma invading through the intestinal wall and/or with pelvic lymph node involvement as evaluated by endorectal ultrasonography (uT3-T4 and/or uN+). Patients were treated with neoadjuvant chemo-radiotherapy (capecitabine + oxaliplatin in combination with 45 Gy of pelvic conformal radiotherapy). Patients have been divided in the following two groups: group A those who had obtained a pathologic complete response M-bM-^@M-^S TRG 1, including the patient without detectable disease who refused surgery, group B any pathologic response other than complete.
2012-04-24 | E-GEOD-29298 | biostudies-arrayexpress