Recent studies indicate that microRNAs (miRNAs) are mechanistically involved in the development of various human malignancies, suggesting that they represent a promising new class of cancer ...biomarkers. However, previously reported methods for measuring miRNA expression consume large amounts of tissue, prohibiting high-throughput miRNA profiling from typically small clinical samples such as excision or core needle biopsies of breast or prostate cancer. Here we describe a novel combination of linear amplification and labeling of miRNA for highly sensitive expression microarray profiling requiring only picogram quantities of purified microRNA.
Comparison of microarray and qRT-PCR measured miRNA levels from two different prostate cancer cell lines showed concordance between the two platforms (Pearson correlation R2 = 0.81); and extension of the amplification, labeling and microarray platform was successfully demonstrated using clinical core and excision biopsy samples from breast and prostate cancer patients. Unsupervised clustering analysis of the prostate biopsy microarrays separated advanced and metastatic prostate cancers from pooled normal prostatic samples and from a non-malignant precursor lesion. Unsupervised clustering of the breast cancer microarrays significantly distinguished ErbB2-positive/ER-negative, ErbB2-positive/ER-positive, and ErbB2-negative/ER-positive breast cancer phenotypes (Fisher exact test, p = 0.03); as well, supervised analysis of these microarray profiles identified distinct miRNA subsets distinguishing ErbB2-positive from ErbB2-negative and ER-positive from ER-negative breast cancers, independent of other clinically important parameters (patient age; tumor size, node status and proliferation index).
In sum, these findings demonstrate that optimized high-throughput microRNA expression profiling offers novel biomarker identification from typically small clinical samples such as breast and prostate cancer biopsies.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We previously determined that intravenous administration of rituximab results in limited penetration of this agent into the leptomeningeal space. Systemic rituximab does not reduce the risk of CNS ...relapse or dissemination in patients with large cell lymphoma. We therefore conducted a phase I dose-escalation study of intrathecal rituximab monotherapy in patients with recurrent CNS non-Hodgkin's lymphoma (NHL).
The protocol planned nine injections of rituximab (10 mg, 25 mg, or 50 mg dose levels) through an Ommaya reservoir over 5 weeks. The safety profile of intraventricular rituximab was defined in 10 patients.
The maximum tolerated dose was determined to be 25 mg and rapid craniospinal axis distribution was demonstrated. Cytologic responses were detected in six patients; four patients exhibited complete response. Two patients experienced improvement in intraocular NHL and one exhibited resolution of parenchymal NHL. High RNA levels of Pim-2 and FoxP1 in meningeal lymphoma cells were associated with disease refractory to rituximab monotherapy.
These results suggest that intrathecal rituximab (10 to 25 mg) is feasible and effective in NHL involving the CNS.
The global physiological effects of glucocorticoids are well established, and the framework of transcriptional regulation by the glucocorticoid receptor (GR) has been described. However, the genes ...directly under GR control that trigger these physiological effects are largely unknown. To address this issue in a single cell type, we identified glucocorticoid-responsive genes in A549 human lung adenocarcinoma cells by microarray analysis and quantitative real-time PCR. Reduction of GR expression by RNA interference diminished the effects of dexamethasone on all tested target genes, thus confirming the essential role of GR in glucocorticoid-regulated gene expression. To identify primary GR target genes, in which GR is a component of the transcriptional regulatory complex, we developed a strategy that uses chromatin immunoprecipitation to scan putative regulatory regions of target genes for sites occupied by specifically bound GR. We screened 11 glucocorticoid-regulated genes, and we identified GR-binding regions for eight of them (five induced and three repressed). Thus, our approach provides a means for rapid identification of primary GR target genes and glucocorticoid-response elements, which will facilitate analyses of transcriptional regulatory mechanisms and determination of hormone-regulated gene networks.
Primary CNS lymphoma is an aggressive form of non-Hodgkin lymphoma whose growth is restricted to the central nervous system. We used cDNA microarray analysis to compare the gene expression signature ...of primary CNS lymphomas with nodal large B-cell lymphomas. Here, we show that while individual cases of primary CNS lymphomas may be classified as germinal center B-cell, activated B-cell, or type 3 large B-cell lymphoma, brain lymphomas are distinguished from nodal large B-cell lymphomas by high expression of regulators of the unfolded protein response (UPR) signaling pathway, by the oncogenes c-Myc and Pim-1, and by distinct regulators of apoptosis. We demonstrate that interleukin-4 (IL-4) is expressed by tumor vasculature as well as by tumor cells in CNS lymphomas. We also identify high expression in CNS lymphomas of several IL-4-induced genes, including X-box binding protein 1 (XBP-1), a regulator of the UPR. In addition, we demonstrate expression of the activated form of STAT6, a mediator of IL-4 signaling, by tumor cells and tumor endothelia in CNS lymphomas. High expression of activated STAT6 in tumors was associated with short survival in an independent set of patients with primary CNS lymphoma who were treated with high-dose intravenous methotrexate therapy.
The histopathological diagnosis of melanoma can be challenging. No currently used molecular markers accurately distinguish between nevus and melanoma. Recent transcriptome analyses have shown the ...differential expression of several genes in melanoma progression. Here, we describe a multi-marker diagnostic assay using 5 markers (ARPC2, FN1, RGS1, SPP1, and WNT2) overexpressed in melanomas. Immunohistochemical marker expression was analyzed in 693 melanocytic neoplasms comprising a training set (tissue microarray of 534 melanomas and nevi), and 4 independent validation sets: tissue sections of melanoma arising in a nevus; dysplastic nevi; Spitz nevi; and misdiagnosed melanocytic neoplasms. Both intensity and pattern of expression were scored for each marker. Based on the differential expression of these 5 markers between nevi and melanomas in the training set, a diagnostic algorithm was obtained. Using this algorithm, the lesions in the validation sets were diagnosed as nevus or melanoma, and the results were compared with the known histological diagnoses. Both the intensity and pattern of expression of each marker were significantly different in melanomas compared to nevi. The diagnostic algorithm exploiting these differences achieved a specificity of 95% and a sensitivity of 91% in the training set. In the validation sets, the multi-marker assay correctly diagnosed a high percentage of melanomas arising in a nevus, Spitz nevi, dysplastic nevi, and misdiagnosed lesions. The multi-marker assay described here can aid in the diagnosis of melanoma.
Purpose: To determine the prognostic significance of a multimarker assay incorporating expression levels of three molecular markers
in primary cutaneous melanoma.
Experimental Design: We assessed ...expression levels of NCOA3, SPP1, and RGS1 using immunohistochemical analysis in a tissue microarray cohort of
395 patients. For each marker, we identified optimal cut-points for expression intensity to predict disease-specific survival
(DSS) and, as a secondary endpoint, sentinel lymph node (SLN) status. The cumulative overexpression of all three markers was
embodied in a multimarker index, and its prognostic effect on DSS and SLN status was assessed using Cox regression, Kaplan-Meier
analysis, and logistic regression. The prognostic effect of this multimarker assay on DSS was assessed in an independent cohort
of 141 patients, in which marker expression levels were scored using immunohistochemical analysis of stained tissue sections.
Results: Increasing multimarker index scores were significantly predictive of reduced DSS and increased SLN metastasis in the 395-patient
cohort. Multivariate logistic regression analysis revealed multimarker expression scores as an independent predictor of SLN
status ( P = 0.001). Multivariate Cox regression analysis showed the independent effect of the multimarker index on DSS ( P < 0.001). The multimarker index was the most significant factor predicting DSS when compared with other clinical and histologic
factors, including SLN status ( P = 0.002). Multimarker expression scores were also the most significantly predictive of DSS in the independent cohort ( P = 0.01).
Conclusions: These results describe a multimarker assay with independent prognostic effect on the prediction of survival associated with
melanoma in two distinct cohorts. (Clin Cancer Res 2009;15(22):6987–92)
Although melanomas with mutant v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) can now be effectively targeted, there is no molecular target for most melanomas expressing wild-type BRAF. Here, ...we show that the activation of Pleckstrin homology domain-interacting protein (PHIP), promotes melanoma metastasis, can be used to classify a subset of primary melanomas, and is a prognostic biomarker for melanoma. Systemic, plasmid-based shRNA targeting of Phip inhibited the metastatic progression of melanoma, whereas stable suppression of Phip in melanoma cell lines suppressed metastatic potential and prolonged the survival of tumor-bearing mice. The human PHIP gene resides on 6q14.1, and although 6q loss has been observed in melanoma, the PHIP locus was preserved in melanoma cell lines and patient samples, and its overexpression was an independent adverse predictor of survival in melanoma patients. In addition, a high proportion of PHIP-overexpressing melanomas harbored increased PHIP copy number. PHIP-overexpressing melanomas include tumors with wild-type BRAF, neuroblastoma RAS viral (v-ras) oncogene homolog, and phosphatase and tensin homolog, demonstrating PHIP activation in triple-negative melanoma. These results describe previously unreported roles for PHIP in predicting and promoting melanoma metastasis, and in the molecular classification of melanoma.
There is growing evidence for a role of HOX homeodomain proteins in normal hematopoiesis. Several HOX genes, including HOXA9 and HOXA10, are expressed in primitive hematopoietic cells, implying a ...role in early hematopoietic differentiation. To identify potential target genes of these two closely related transcription factors, human CD34+ umbilical cord blood cells were transduced with vectors expressing either HOXA9 or HOXA10 and analyzed with cDNA micro‐arrays. Statistical analysis using significance analysis of microarrays revealed a common signature of several hundred genes, demonstrating that the transcriptomes of HOXA9 and HOXA10 largely overlap in this cellular context. Seven genes that were upregulated by both HOX proteins were validated by real‐time reverse transcription polymerase chain reaction. HOXA9 and HOXA10 showed positive regulation of genes in the Wnt pathway, including Wnt10B and two Wnt receptors Frizzled 1 and Frizzled 5, an important pathway for hematopoietic stem cell (HSC) self‐renewal. Other validated genes included v‐ets‐related gene (ERG), Iroquois 3 (IRX3), aldehyde dehydrogenase 1 (ALDH1), and very long–chain acyl‐CoA synthetase homolog 1 (VLCS‐H1). GenMAPP (Gene Micro Array Pathway Profiler) analysis indicated that HOXA10 repressed expression of several genes involved in heme biosynthesis and three globin genes, indicating a general suppression of erythroid differentiation. A number of genes regulated by HOXA9 and HOXA10 are expressed in normal HSC populations.
To assess the prognostic significance of nuclear receptor coactivator-3 (NCOA3) overexpression in primary cutaneous melanoma.
NCOA3 expression was assessed using immunohistochemical analysis of a ...melanoma tissue microarray (TMA) containing primary melanomas from 343 patients with defined histology and follow-up. The impact of the presence or absence of various prognostic factors on relapse-free survival (RFS) and disease-specific survival (DSS) of melanoma patients was assessed using Cox regression and Kaplan-Meier analysis. The impact of presence or absence of various factors on sentinel lymph node (SLN) metastasis was assessed using logistic regression analysis.
Increasing degree of NCOA3 expression was significantly predictive of SLN metastasis (P = .013) and the mean number of SLN metastases (P = .031). Kaplan-Meier analysis demonstrated a significant association between NCOA3 overexpression and reduced RFS (P = .021) and DSS (P = .030). Logistic regression analysis revealed increasing degree of NCOA3 expression to be an independent predictor of SLN status (P = .017). Multivariate Cox regression analysis showed the independent impact of NCOA3 expression on RFS (P = .0095) and DSS (P = .021). NCOA3 was the most powerful factor predicting DSS, outperforming tumor thickness and ulceration.
These results identify NCOA3 as a novel, independent marker of melanoma outcome, with a significant impact on SLN metastasis, RFS, and DSS.
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