Phasor Representation Approach for Rapid Exploratory Analysis of Large Infrared Spectroscopic Imaging Data Sets.

Formalin-fixed paraffin-embedded (FFPE) tissue represents a valuable source for translational cancer research. However, the widespread application of various downstream methods remains challenging. Here, we aimed to assess the feasibility of a genomic and gene expression analysis workflow using FFPE breast cancer (BC) tissue. We conducted a systematic literature review for the assessment of concordance between FFPE and fresh-frozen matched tissue samples derived from patients with BC for DNA and RNA downstream applications. The analytical performance of three different nucleic acid extraction kits on FFPE BC clinical samples was compared. We also applied a newly developed targeted DNA Next-Generation Sequencing (NGS) 370-gene panel and the nCounter BC360® platform on simultaneously extracted DNA and RNA, respectively, using FFPE tissue from a phase II clinical trial. Of the 3701 initial search results, 40 articles were included in the systematic review. High degree of concordance was observed in various downstream application platforms. Moreover, the performance of simultaneous DNA/RNA extraction kit was demonstrated with targeted DNA NGS and gene expression profiling. Exclusion of variants below 5% variant allele frequency was essential to overcome FFPE-induced artefacts. Targeted genomic analyses were feasible in simultaneously extracted DNA/RNA from FFPE material, providing insights for their implementation in clinical trials/cohorts.

Infrared (IR) spectroscopic imaging is growing in popularity as a technique for distinguishing tissue types and diagnosing disease states, including breast cancer. The combination of an IR focal-plane array detector and a Fourier transform infrared (FT-IR) microscope provides the researcher with chemical information in each pixel of the image detected. IR spectroscopic images are collected in reflectance from tissue biopsies mounted on inexpensive IR-reflective glass microscope slides that are still transparent in visible light. These slides allow us to perform FT-IR microspectroscopic imaging studies on samples that can be evaluated by conventional pathology. A chemical marker in stroma near epithelial cells has been discovered based on its IR spectroscopic signature. This marker may be useful for classifying a tissue as cancerous or non-cancerous.

Conventional Fourier transform infrared (FTIR) spectroscopy is a workhorse analytical technique providing quantitative and qualitative information on a vast array of materials, ranging from semiconductors to biological samples. By coupling a Michelson interferometer and infrared (IR) microscope to an IR sensitive focal-plane array detector, we have added an imaging component to the existing analytical capabilities of FTIR spectroscopy. This additional capability makes it possible to image the distribution of subtle structural and compositional changes reflected in the infrared spectrum within heterogeneous materials. As such, it is an extremely powerful analytical tool which is currently employed in a variety of basic research and industrial applications. Similarly the utility of FTIR spectroscopy for the investigation of biological materials can be greatly extended by recording spectroscopic imaging data sets instead of single FTIR spectra. This spectroscopic imaging capability, especially when combined with microscopy, ensures that information concerning spatial variations in the system’s biochemistry, as well as its cellular morphology, is maintained.

Background: Carriers of mutations in the breast cancer susceptibility gene BRCA2 have a 50-80% lifetime risk of developing breast cancers, about 70% of which are positive for estrogen receptor (ER), a key oncogenic hormone receptor. Metastatic ER+ tumors also respond to PARP inhibitors associated with their DNA repair defect. There remains much to understand regarding estrogen signaling in BRCA2 carriers and preventing cancers in this high-risk population. Methods: We studied the transcriptomes and in-vitro growth of luminal progenitors and mature luminal cells derived from primary human normal breast tissue obtained from BRCA2 carriers and wild-type patients undergoing prophylactic mastectomy and reduction mammoplasty procedures, respectively. Subsequently, formalin-fixed paraffin-embedded breast cancer tissue samples from twelve case-control matched pairs of BRCA2 carriers and wild-type patients were investigated for ER genomic binding, H3K27Ac enhancer marks, and gene expression changes. Results: Luminal progenitors and mature luminal cells have different gene expression patterns. Unsupervised clustering of transcriptomes from normal tissue of three pairs of BRCA2-mutant and wildtype patients suggested that BRCA2 mutation status can segregate transcriptomes from luminal progenitors but not mature luminal cells. These differential transcriptomes in luminal progenitor cells from BRCA2 carriers were enriched for cell proliferation genes. In agreement, greater proliferative phenotype was observed in BRCA2-mutant luminal progenitor cells in comparison to the wild-type cohort. Interestingly, clustering analyses of twelve pairs of breast tumors indicated no clear differences between ER cistromes, enhancer marks and gene expression between BRCA2 carriers and wildtype patients. Because luminal progenitor cells are more likely to contribute to tumorigenesis, we hypothesize that the identified BRCA2-mutant signature in normal progenitor cells could be retained in tumors obtained from BRCA2 carriers. Conclusions: There are differential gene expression patterns between luminal progenitors and mature luminal cells obtained from normal human breast tissue. The transcriptomes in the luminal progenitor but not mature luminal cells segregate differently based on the BRCA2 mutation status. This identified BRCA2-mutant gene signature in luminal progenitor cells is enriched for pro-proliferation pathways, and BRCA2-mutant luminal progenitor cells exhibit higher cell proliferation, suggesting a potential cell-of-origin in BRCA2-associated breast cancers. Importantly, no significant differences in transcriptomes and ER cistromes are observed in breast tumors from BRCA2 carriers and non-carriers, indicating a need to identify BRCA2-mutant gene signature that may assist in segregating ER+ breast cancers in this high-risk populations. The knowledge from this study may assist in pioneering strategies for cancer prevention in high-risk BRCA2 mutation carriers. Citation Format: Hari Singhal, David Chi, Elgene Lim, Housheng He, Raga Vadhi, Prakash K. Rao, Henry W. Long, Andrea L. Richardson, Judy Garber, Myles Brown. Estrogen signaling in mature luminal and luminal progenitor cells of BRCA2 carriers and non-carriers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-257. doi:10.1158/1538-7445.AM2017-LB-257

This work presents a pilot study to illustrate the potential of Fourier transform infrared (FT-IR) imaging in breast cancer research. Using this technique, we have acquired infrared (IR) microspectroscopic images from healthy and cancerous breast tissue section from one patient. First of all, a Studentt-test was applied, showing DNA/RNA spectral region (1400–1000 cm−1) as the most discriminant for the differentiation between healthy and tumor samples. Afterwards, a supervised pattern recognition method, Partial Least Squares (PLS) was used to develop an automated classifier to discriminate the two classes of data. Infrared spectra of independent IR measurements were used to test the classifier. The class identity was correlated with information obtained by histopathologic gold standard. The results showed that more than 95% of the training and validation spectra were correctly identified. We demonstrate that combination between IR microspectroscopic imaging and multivariate data analysis can be used as a complement to present diagnostic tools for breast cancer.

ObjectiveThe power of genome-wide association studies (GWAS) to identify common disease variants depends primarily on the number of included samples. The availability of formalin-fixed paraffin-embedded (FFPE) samples in pathology institutes provides a valuable resource for GWAS, but the use of this material poses significant challenges. To explore the suitability of utilizing FFPE tissue for GWAS, we analysed the genotyping concordance between corresponding FFPE and blood samples. We evaluated both microarray technology and low-coverage whole-genome sequencing (lcWGS) to determine whether there were differences between genotyping methods.ResultsIn our concordance study, FFPE tissue showed high recall and precision values across both genotyping methods when compared to matched blood samples for single nucleotide polymorphisms. This demonstrates that FFPE samples are suitable for GWAS and that both methods are viable options for genotyping. However, microarray technology outperformed lcWGS, as evidenced by significantly higher recall (p = 0.005) and precision (p = 0.003) values. This, together with the lower cost of genotyping and computational efficiency, makes microarray technology currently the superior method for GWAS using FFPE tissue. Nevertheless, lcWGS has shown reliable results and holds the potential to provide more comprehensive and unbiased genetic variant analysis across diverse populations in the future. Our results show that the large number of FFPE samples stored in pathology institutes can significantly increase the power of future GWAS.

RNA and DNA extracted from formalin-fixed paraffin-embedded (FFPE) tissue is problematic due to chemical modifications and continued degradation over time. we compared quantity of RNA extracted by two different protocols from 14 recently archived from patients suffered from different cancers distributed among formalin-fixed paraffin-embedded (FFPE) breast cancer tissues ,thyroid cancer tissues and Cervical uterus carcinoma tissues by using Guanidine isothiocyanate (GTC)with phenol-chloroform (protocol-1) and Silica Gel Column(SGC) dependent on spin column purification-based ( protocol- 2), to assess, which technique is the most efficient and reproducible in terms of total yield and purity. The results showed RNA isolated with SGC technique was characterized by higher mean concentration in a range (80-180) µg/ml ,but it give positive results to 12 sample with degradation in comparison with RNA isolated by the (GTC) technique (protocol-1), comparison with total RNA extraction from human blood ( two distinguished bands ) .In this study comparative methods have been performed to analyze the efficiency for extraction and purification of Genomic DNA from six selective FFPE Tissues samples, revealing that the extraction of DNA by using extraction modified method give good result with yield higher mean concentration of DNA in a range (160-260) µg/ml.The lysis of FFPE Tissues was enhanced by increased the concentration of proteinase K to30 mg\ml for 2 hour at 65C, which considered the best time for lysis tissues and heated comparable with results that obtained from lysis tissues by using 20mg\ml for (24 -48 hours) at 55C

11018 Background: While several recently discovered gene fusions already play an important role in personalized cancer treatment, many cancer gene fusions remain to be discovered. Next generation sequencing has enabled identification of many rare gene fusion events in fresh or frozen solid tumors. There is a need to detect gene fusions in transcriptomes of formalin-fixed paraffin-embedded (FFPE) tumor tissue, for which there is long-term clinical outcome data. We therefore sought to develop bioinformatics methods to detect fusion transcripts in FFPE tissue and to characterize their association with clinical outcomes. Methods: RNA sequencing libraries were created and sequenced from tumor biopsy tissues (Plos One 2012 7(7): e40092) of two ER+ breast cancer cohorts consisting of 136 and 77 patients, for which clinical outcomes were available. The fusion junctions were nominated by the RNA-seq aligner GSNAP and further filtered to consider discontinuous expression patterns at exon/intron levels. Results: A total of 108 candidate fusion transcripts were detected and RT-PCR assays confirmed 89% of the top ranking fusion transcript candidates. The majority (82%) of identified fusion gene partners are listed in the COSMIC database of known cancer sequence variations. Of note, several patients expressed multiple fusion transcripts that are significantly associated with tumor progression (P<0.001), including genes associated with cell proliferation and cellular metabolism. Furthermore, these patients also harbored inter-chromosomal gene fusions. It is noteworthy that several gene fusions were present in multiple patients. In one of these recurrent fusions the estrogen receptor gene acts as the fusion pair donor. Conclusions: Novel bioinformatics approaches developed here demonstrate the ability to detect fusion transcripts as biomarkers from archival FFPE tissues that associate with breast cancer progression. Some gene fusions were common in multiple patients and deserved further study.

BackgroundPathologists commonly employ the Ki67 immunohistochemistry labelling index (LI) when deciding appropriate therapeutic strategies for patients with breast cancer. However, despite several attempts at standardizing the Ki67 LI, inter-observer and inter-laboratory bias remain problematic. We developed a flow cytometric assay that employed tissue dissociation, enzymatic treatment and a gating process to analyse Ki67 in formalin-fixed paraffin-embedded (FFPE) breast cancer tissue.ResultsWe demonstrated that mechanical homogenizations combined with thrombin treatment can be used to recover efficiently intact single-cell nuclei from FFPE breast cancer tissue. Ki67 in the recovered cell nuclei retained reactivity against the MIB-1 antibody, which has been widely used in clinical settings. Additionally, since the method did not alter the nucleoskeletal structure of tissues, the nuclei of cancer cells can be enriched in data analysis based on differences in size and complexity of nuclei of lymphocytes and normal mammary cells. In a clinical study using the developed protocol, Ki67 positivity was correlated with the Ki67 LI obtained by hot spot analysis by a pathologist in Japan (rho = 0.756, P < 0.0001). The number of cancer cell nuclei subjected to the analysis in our assay was more than twice the number routinely checked by pathologists in clinical settings.ConclusionsThe findings of this study showed the application of this new flow cytometry method could potentially be used to standardize Ki67 assessments in breast cancer.

Background: Breast cancer is the most commonly diagnosed malignant disease and the leading cause of cancer death among females, with approximately 2.3 million new cases and 685,000 deaths worldwide. Recent studies indicate that Melanoma-associated gene C2 (MAGEC2) expression is linked to poor prognosis, aggressive clinical course, chemotherapy resistance, and poor outcomes in breast cancer patients. MAGEC2, part of the MAGE family on the X chromosome, interacts with STAT3 in tumor cells, preventing its degradation and enhancing transcriptional activity. Objective Evaluation of the prognostic role of MAGEC2 expression in women with breast cancers and its association with other prognostic factors. Method: This study examined 46 formalin-fixed paraffin-embedded breast cancer tissue blocks of varying grades and histopathological features. Hematoxylin and eosin staining assessed histopathological diagnosis, while polyclonal antibody for MAGEC2 was used for immunohistochemical staining. MAGEC2 expression was scored by staining intensity (0-3) and percentage (0-100%), with semiquantitative scores indicating no expression (-ve), mild (+1), moderate (+2), and high expression (+3). Results: In this study of 46 invasive breast cancer cases, 23.9% had (3+) MAGEC2 expression, 47.8% had (2+), 23.9% had (1+), and 4.4% had no expression. MAGEC2 over-expression was significantly associated with higher tumor grade (p=0.019), but not with other clinicopathological parameters like patient age, histology type, or hormonal receptor status (PR, ER, HER-2). Conclusion: MAGEC2 according to these results proves to be a powerful marker in predicting the prognosis of breast cancer. With a further work up and with more studies, it may be of routine use in the near future.

PurposeThe purpose of the present study was to investigate the biological and clinical significance of GATA binding protein 3 (GATA3) in bladder cancer patients.Patients and MethodsFor the detection of the correlation between GATA3 expression and bladder cancer, we downloaded the mRNA expression data from the Cancer Genome Atlas (TCGA) database and conducted immunohistochemistry staining on formalin-fixed paraffin-embedded (FFPE) sample tissues. Then, bladder cancer cell lines were utilized to investigate the potential functions of GATA3 by cell apoptosis, proliferation and cycle assays.ResultsThe mRNA data from TCGA database and bladder cancer cell lines suggested that GATA3 mRNA expression was significantly higher compared with normal tissues and cells. Conversely, the Western blot assay revealed that the expression of GATA3 was significantly lower in bladder cancer than normal urothelial cell line. Additionally, we found that over-expression of GATA3 was significantly associated with tumor subtype (P = 0.001 in TCGA; P = 0.004 in FFPE tissues), earlier clinical stage (P < 0.001 in TCGA; P < 0.001 in FFPE) and lower grade tumor (P = 0.057 in TCGA; P = 0.002 in FFPE). Kaplan-Meier analysis and multivariate Cox regression analysis indicated that age (P < 0.001 in both cohort), clinical stage (P = 0.028 in TCGA; P = 0.011 in FFPE), recurrence (P < 0.001) and low GATA3 in TCGA cohort (P = 0.035) but high GATA3 in FFPE cohort (P = 0.033) were independent risk factors for overall survival in patients. The assay to detect potential functions of GATA3 indicated that this biomarker could arrest the cell cycle of G2/M and S phase in T24 cells, and inhibit bladder cancer cells proliferation.ConclusionCollectively, our findings identified that GATA3 served as an important prognosis biomarker for bladder cancer patients. However, the mechanism of GATA3 in bladder cancer deserves further studies.

Study of matrix-filler interaction of polypropylene/silica composite by combined infrared (IR) spectroscopic imaging and disrelation mapping

The majority of biopsies in both basic research and translational cancer studies are preserved in the format of archived formalin-fixed paraffin-embedded (FFPE) samples. Profiling histone modifications in archived FFPE tissues is critically important to understand gene regulation in human disease. The required input for current genome-wide histone modification profiling studies from FFPE samples is either 10–20 tissue sections or whole tissue blocks, which prevents better resolved analyses. But it is desirable to consume a minimal amount of FFPE tissue sections in the analysis as clinical tissues of interest are limited. Here, we present FFPE tissue with antibody-guided chromatin tagmentation with sequencing (FACT-seq), the first highly sensitive method to efficiently profile histone modifications in FFPE tissues by combining a novel fusion protein of hyperactive Tn5 transposase and protein A (T7−pA−Tn5) transposition and T7 in vitro transcription. FACT-seq generates high-quality chromatin profiles from different histone modifications with low number of FFPE nuclei. We proved a very small piece of FFPE tissue section containing ∼4000 nuclei is sufficient to decode H3K27ac modifications with FACT-seq. H3K27ac FACT-seq revealed disease-specific super enhancers in the archived FFPE human colorectal and human glioblastoma cancer tissue. In summary, FACT-seq allows decoding the histone modifications in archival FFPE tissues with high sensitivity and help researchers to better understand epigenetic regulation in cancer and human disease.

The majority of biopsies in both basic research and translational cancer studies are preserved in the format of archived formalin-fixed paraffin-embedded (FFPE) samples. Profiling histone modifications in archived FFPE tissues is critically important to understand gene regulation in human disease. The required input for current genome-wide histone modification profiling studies from FFPE samples is either 10-20 tissue sections or whole tissue blocks, which prevents better resolved analyses. Nevertheless, it is desirable to consume a minimal amount of FFPE tissue sections in the analysis as clinical tissue of interest are limited. Here, we present F FPE tissue with a ntibody-guided c hromatin t agmentation with sequencing (FACT-seq), highly sensitive method to efficiently profile histone modifications in FFPE tissue by combining a novel fusion protein of hyperactive Tn5 transposase and protein A (T7-pA-Tn5) transposition and T7 in vitro transcription. FACT-seq generates high-quality chromatin profiles from different histone modifications with low number of FFPE nuclei. We showed a very small piece of FFPE tissue section containing ~4000 nuclei is sufficient to decode H3K27ac modifications with FACT-seq. In archived FFPE human colorectal and human glioblastoma cancer tissue, H3K27ac FACT-seq revealed disease specific super enhancers. In summary, FACT-seq allows researchers to decode histone modifications like H3K27ac and H3K27me3 in archival FFPE tissues with high sensitivity, thus allowing us to understand epigenetic regulation. Graphical abstract: ( i ) FFPE tissue section; ( ii ) Isolated nuclei; ( iii ) Primary antibody, secondary antibody and T7-pA-Tn5 bind to targets; ( iv ) DNA purification; ( v ) In vitro transcription and sequencing library preparation; ( vi ) Sequencing.

Fluorescence in situ hybridization (FISH) has revolutionized molecular cytogenetic analysis since the 1980s, enabling precise localization of DNA sequences in cells and tissues. Despite its relevance, applying FISH to formalin-fixed paraffin-embedded (FFPE) tissue samples encounters significant technical challenges. This review addresses the main issues encountered in this context, such as inadequate fixation, contamination, block and slide age, inadequate pretreatment, and FISH technique. Proposed solutions include optimized pretreatment protocols, monitoring of blockage, careful selection of probes, and thorough analysis of results. Implementing good laboratory practices and quality control strategies are essential to ensure reliable results. Additionally, the use of emerging technologies such as artificial intelligence and digital pathology offers new perspectives for improving the efficiency and accuracy of FISH in FFPE samples. This review highlights the importance of a careful and personalized approach to overcome the technical challenges associated with FISH in FFPE samples, strengthening its role in research and clinical diagnosis. RESEARCH HIGHLIGHTS: Few FISH studies on FFPE: The scarcity of studies specifically addressing FISH applications in FFPE tissues highlights a critical gap in the literature. Troubleshooting FISH in FFPE tissues: Identifying and addressing common challenges in FISH techniques when applied to FFPE samples, such as signal quality and hybridization efficiency. Critical aspects of FISH technique: Discuss the main technical considerations crucial for successful FISH in FFPE tissues, including sample preparation, probe selection, and protocol optimization.