Potential Biomarkers For Detection Research Articles

Abstract 5588: Epithelial-to-mesenchymal markers of circulating tumor cells for detection of castration-resistant prostate cancer

Abstract Approximately 30% of prostate cancer (PCa) patients who receive androgen-deprivation therapy experience disease progression, including bone metastasis, in 18-36 months. Clinical diagnosis of this castration resistance is primarily based on a continuous rise in serum PSA levels during therapy. However, the underlying disease progression predates the clinical onset of castration resistance by many months. The clinical challenge is to distinguish indolent vs aggressive cancer for better disease management. During the prostate cancer progression, malignant circulating tumor cells (CTC) shed from the primary site into the bloodstream through epigenetic modifications and an epithelial-to-mesenchymal transition (EMT). Evidence suggests that increased CTCs are present in the blood of castration-resistant PCa patients and can be obtained through routine phlebotomy. EMT changes of CTCs present a great potential for disease prognosis, treatment stratification and subsequent disease monitoring. We have recently established the combined microfiltration-micromanipulation system (CM2S) to enrich prostate CTCs from blood as published in The Prostate. Our preliminary studies based on a relatively small sample size show that CTCs isolated from advanced PCa patients often lose the typical features of prostate epithelial cells and display incremental EMT-related gene expression signatures, higher elasticity and smoother membrane features. Furthermore, incremental expression of these genes and particular nanomechanical features in CTCs are associated with castration-resistant and metastatic PCa. In this study, we would like expand the sample size to clinically develop this methodology. CTCs were isolated from patients' blood (∼15 ml) using microfiltration system (ScreenCell). We analyzed castration-sensitive (CS) and castration-resistant (CR) PCa cells and CTCs using high throughput microfluidic single-cell RT-PCR. The data were subject to hierarchical clustering, violin plot and Ingenuity Pathway Analysis (IPA). Increased expression of EMT genes was found in CR PCa cells and CTCs as compared to CS counterparts. IPA indicated that these EMT genes are closely related to AKT, β-catenin, Myc and NFκB pathways. Some of CTCs isolated from patients were subject to nanomechanical and nanochemical analysis using PeakForce QNM Catalyst atomic force microscopy (AFM) (Bruker). CTCs of CR patients are about 3 fold more elastic and 7 fold more adherent than CTCs of CS patients. Additionally, CTCs of CR patients are about 3 fold more deformable than CTCs of CS patients. In conclusion, we confirmed our previous study with a larger patient sample size. The increased expression of EMT-related genes and nanomechanical and nanochemical phenotypes in CTCs are potential biomarkers for detection of the castration-resistant PCa, treatment stratification and subsequent disease monitoring. Citation Format: Chun-Liang Chen, Pawel Osmulski, Devalingam Mahalingam, Aaron M. Horning, Rohit R. Jadhav, Anna D. Louie, Chiou-Miin Wang, Tim H.-M. Huang. Epithelial-to-mesenchymal markers of circulating tumor cells for detection of castration-resistant prostate cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5588. doi:10.1158/1538-7445.AM2014-5588

Abstract 1659: Evaluation of microRNA expression profiles and their associations with risk alleles in lymphoblastoid cell lines of familial ovarian cancer

Abstract Interindividual variations of microRNA expression are likely to influence the expression of microRNA target genes, and therefore, contribute to phenotypic differences in humans, including cancer susceptibility. Whether microRNA expression variation has any role in ovarian cancer development is still unknown. Here we evaluated microRNA expression profiles in lymphoblastoid cell lines (LCLs) from 74 women with familial ovarian cancer and 47 controls. We found that microRNA expression profiles in the LCLs of the cases were significantly different from that in the controls with 91% accuracy by 95 differentially expressed microRNAs. To assess the potential implications of microRNAs in ovarian cancer, we investigated the associations between microRNA expression and ovarian cancer risk alleles discovered from genome wide association studies. We observed 130 significant associations at a permutation level of 0.01. Compared to other risk variants, rs3814113 and rs2072590 had the greatest number of significant associations (68 and 37, respectively). Interestingly, 14 microRNAs which were associated with ovarian cancer risk alleles belong to 5 microRNA clusters. The most notable cluster is the tumorigenic miR-17-92 cluster with 5 microRNAs, all of which are significantly associated with rs3814113. Using pathway analysis, several key biological pathways were significantly overrepresented, such as cellular response to stress (P=2.87x10−06), etc. Our results indicate that microRNA expression profiles in LCLs can serve as potential detection biomarkers for familial ovarian cancer. Further characterization of significant associations between microRNAs and risk alleles could facilitate the understanding of the functions of these GWAS discovered risk alleles in the genetic etiology of ovarian cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1659. doi:1538-7445.AM2012-1659

Identification of protein biomarkers in nipple aspiration fluid

Nipple aspiration fluid (NAF) can be useful for studying relevant changes in breast parenchyma and identification of potential biomarkers for detection, monitoring therapy and risk assessment of breast cancer. NAF has been investigated extensively for identification of protein biomarkers using approaches such as ELISA, immunoassay, western blot for chosen individual protein markers such as prostate specific antigen, basic fibroblast growth factor, prostaglandin E2 etc., or by using comprehensive analysis of protein expression using platforms such as surface enhanced laser desorption ionization-time of flight mass spectrometry. The results of the former studies indicate the potential value of selected markers for detection of cancer which have not been validated in larger studies. The results of majority of studies that performed comprehensive protein analysis indicate that protein expression patterns are highly conserved between cancerous and non cancerous breasts and that protein profiling of NAF may have more value for risk assessment than for detection of breast cancer. Using a novel approach of protein microarray for seven markers with significant differences in protein levels were found between NAF obtained from cancerous and contralateral breast and healthy controls for markers such as cathepsin and urokinase. Overall, proteomic studies of NAF indicate the probable value of several protein biomarkers. There is a need for validation of the markers that have been identified so far, to be promising for risk assessment or early detection of breast cancer in large prospective clinical trials.

Quantification of Fragments of Human Serum Inter-α-Trypsin Inhibitor Heavy Chain 4 by a Surface-Enhanced Laser Desorption/Ionization-Based Immunoassay

Several proteolytically derived fragments from the proline-rich region (PRR) of human inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) have been identified by surface-enhanced or matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS or MALDI-TOF-MS) as potential disease markers. Previously, we developed a SELDI-based immunoassay that can simultaneously distinguish and quantify multiple isoforms/variants of a protein/peptide of interest. In this study, we used this high-throughput approach to quantify and characterize the extensive fragmentation within the PRR of human serum ITIH4 and determined its association with different disease conditions. The ITIH4-related fragments were first immunocaptured by use of beads coupled with peptide-specific antibodies. The eluates were then studied by SELDI-TOF-MS. In addition, freshly collected and immediately processed serum and plasma samples were used to analyze the ex vivo stability of these ITIH4 fragments. Human serum ITIH4 was shown to be extensively proteolytically processed within the PRR, and its fragmentation patterns were closely associated with different disease conditions. Fragmentation patterns were generally consistent with cleavages by endoprotease followed by exoprotease actions. Observed fragments changed little under different assay conditions or blood collection and processing procedures. The fragmentation patterns within the PRR of human serum ITIH4 are associated with different disease conditions and may hold important diagnostic information. These fragmentation patterns could be useful as potential biomarkers for detection and classification of cancer.