Project description:BackgroundCell-free DNA (cfDNA) profiling is increasingly used to guide cancer care, yet mutations are not always identified. The ability to detect somatic mutations in plasma depends on both assay sensitivity and the fraction of circulating DNA in plasma that is tumor-derived (i.e., cfDNA tumor fraction). We hypothesized that cfDNA tumor fraction could inform the interpretation of negative cfDNA results and guide the choice of subsequent assays of greater genomic breadth or depth.MethodsPlasma samples collected from 118 metastatic cancer patients were analyzed with cf-IMPACT, a modified version of the FDA-authorized MSK-IMPACT tumor test that can detect genomic alterations in 410 cancer-associated genes. Shallow whole genome sequencing (sWGS) was also performed in the same samples to estimate cfDNA tumor fraction based on genome-wide copy number alterations using z-score statistics. Plasma samples with no somatic alterations detected by cf-IMPACT were triaged based on sWGS-estimated tumor fraction for analysis with either a less comprehensive but more sensitive assay (MSK-ACCESS) or broader whole exome sequencing (WES).ResultscfDNA profiling using cf-IMPACT identified somatic mutations in 55/76 (72%) patients for whom MSK-IMPACT tumor profiling data were available. A significantly higher concordance of mutational profiles and tumor mutational burden (TMB) was observed between plasma and tumor profiling for plasma samples with a high tumor fraction (z-score≥5). In the 42 patients from whom tumor data was not available, cf-IMPACT identified mutations in 16/42 (38%). In total, cf-IMPACT analysis of plasma revealed mutations in 71/118 (60%) patients, with clinically actionable alterations identified in 30 (25%), including therapeutic targets of FDA-approved drugs. Of the 47 samples without alterations detected and low tumor fraction (z-score<5), 29 had sufficient material to be re-analyzed using a less comprehensive but more sensitive assay, MSK-ACCESS, which revealed somatic mutations in 14/29 (48%). Conversely, 5 patients without alterations detected by cf-IMPACT and with high tumor fraction (z-score≥5) were analyzed by WES, which identified mutational signatures and alterations in potential oncogenic drivers not covered by the cf-IMPACT panel. Overall, we identified mutations in 90/118 (76%) patients in the entire cohort using the three complementary plasma profiling approaches.ConclusionscfDNA tumor fraction can inform the interpretation of negative cfDNA results and guide the selection of subsequent sequencing platforms that are most likely to identify clinically-relevant genomic alterations.
Project description:Here we used activating (purmorphamine) and blocking (cyclopamine) drugs characterized of the Hedgehog pathway in adipose tissue-derived stem cells and identified mRNAs associated polysomes or free fraction in each condition.
Project description:Low-coverage whole genome sequencing of cell-free DNA from immunosuppressed cancer patients enables tumor fraction determination and reveals relevant copy number alterations
Project description:To evaluate the efficiency of apatinib on vascularized patient-derived tumor organoids (PDTOs)-on-a-chip derived from patients with metastatic tumors, we conducted RNA-seq analysis on organoids derived from patients whom had metastatic tumors. Specifically, we extracted RNA for sequencing from tumor cells of organoids either cultured alone or co-cultured with MVs with or without apatinib treatment
Project description:Breast cancers of the luminal B subtype are frequent tumors with high proliferation and poor prognosis. Epigenetic alterations have been found in breast tumors and in biological fluids. We aimed to profile the cell-free DNA (cfDNA) methylome of metastatic luminal B breast cancer (LBBC) patients using an epigenomic approach to discover potential noninvasive biomarkers. Plasma cfDNA was analyzed using the Infinium MethylationEpic array (EPIC array) in a cohort of 14 women, including metastatic LBBC patients and healthy controls.
Project description:First line chemotherapy with platinum and cetuximab is usually offered to RM-HNSCC pts. In the Extreme trial a median progression free survival (PFS) time of 5.6 months was reported. However, a small fraction of pts achieves a prolonged PFS (> than 12 months). Till now, no recognized predictive biological factor has been identified.
Project description:A large number of transcription factors are enriched at specific DNA sites in the nuclear, playing an important role in the regulation of gene expression. Chromatin immunoprecipitation sequencing (ChIP seq) is the classic method for the detection of chromatin transcription factor landscape. This method is limited by the complexity of steps, low signal to noise ratio, large number of cells required, high cost, and heavy reliance on high-purity high-performance antibodies. In recent years, based on MNase and Tn5 transposase, CUT&RUN, CUT&Tag, ChIL-seq, itChIP-seq have been developed and widely used, but they still rely on antibodies and take a long time. Here, we develop an antibody-free and fast method for profiling transcription factor binding sites, called Aptamer-Guided Chromatin Cleavage with Sequencing (AptaChC-seq). AptaChC-seq has the advantages of high signal to noise ratio, low cost, good reproducibility.
Project description:We analyzed cell-free microRNAs (cfmiRs) in blood, tissue, and urine samples of melanoma patients to find potential biomarkers for monitoring and assessing early detection of melanoma metastasis. This study demonstrates that identifying cfmiR signatures in body fluids may allow for detection and assessment of melanoma brain metastasis (MBM) and metastatic melanoma patients undergoing checkpoint inhibitor immunotherapy treatments.