Multifocal organoids reveal clonal associations between synchronous intestinal tumors with pervasive heterogeneous drug responses.

Multifocal colorectal cancer (CRC) comprises both clonally independent primary tumors caused by inherited predisposition and clonally related tumors mainly due to intraluminal spreading along an intact basement membrane. The distinction between these multifocal CRCs is essential because therapeutic strategies vary according to the clonal association of multiple tumor masses. Here, we report one unique case of synchronous intestinal cancer (SIC) with tumors occurring along the entire bowel tract, including the small intestine. We established six patient-derived organoids (PDOs), and patient-derived cell lines (PDCs) from each site of the SIC, which were subjected to extensive genomic, transcriptomic, and epigenomic sequencing. We also estimated the drug responses of each multifocal SIC to 25 clinically relevant therapeutic compounds to validate how the clinically actionable alternations between SICs were associated with drug sensitivity. Our data demonstrated distinct clonal associations across different organs, which were consistently supported by multi-omics analysis, as well as the accordant responses to various therapeutic compounds. Our results indicated the imminent drawback of a single tumor-based diagnosis of multifocal CRC and suggested the necessity of an in-depth molecular analysis of all tumor regions to avoid unexpected resistance to the currently available targeted therapies.

Establishment and characterization of 18 human colorectal cancer cell lines.

Colorectal cancer (CRC) represents the third most frequently diagnosed malignancy worldwide and is the second most common cause of tumor-associated mortalities in Korea. Due to the disease's aggressive behavior, the 5-year survival rate for CRC patients remains unpromising. Well-characterized cell lines have been used as a biological model for studying the biology of cancer and developing novel therapeutics. To assist in vitro studies, 18 CRC cell lines (SNU-1566, SNU-1983, SNU-2172, SNU-2297, SNU-2303, SNU-2353B, SNU-2359, SNU-2373B, SNU-2407, SNU-2423, SNU-2431, SNU-2465, SNU-2493, SNU-2536C, SNU-2621B, SNU-NCC-61, SNU-NCC-376, and SNU-NCC-377) derived from Korean patients were established and characterized in the present study. General characteristics of each cell line including doubling time, in vitro morphology, mutational profiles, and protein expressions of CRC-related genes were described. Whole exome sequencing was performed on each cell line to configure mutational profiles. Single nucleotide variation, frame shift, in-frame deletions and insertions, start codon deletion, and splice stop codon mutation of various genes were found and classified based on their pathogenicity reports. In addition, cell viability was assayed to measure their sensitivities to 24 anti-cancer drugs including anti-metabolites, kinase inhibitors, histone deacetylase inhibitors, alkylating inhibitors, and topoisomerase inhibitors, all widely used for various cancers. On testing, five CRC cell lines showed MSI, of which MLH1 or MSH6 gene was mutated. These newly established CRC cell lines can be used to investigate biological characteristics of CRC, particularly for investigating gene alterations associated with CRC.

Determination of endogenous concentrations of nitrites and nitrates in different types of cheese in the United States: method development and validation using ion chromatography.

Nitrites and nitrates can be present in dairy products from both endogenous and exogenous sources. In the European Union (EU), 150 mg kg-1 of nitrates are allowed to be added to the cheese milk during the manufacturing process. The CODEX General Standard for Food Additives has a maximum permitted level of 50 mg kg-1 residue in cheese, while in the United States (U.S.) nitrates are unapproved for use as food additives in cheese. In order to be able to investigate imported cheeses for nitrates intentionally added as preservatives and the endogenous concentrations of nitrates and nitrites present in cheeses in the U.S. marketplace, a method was developed and validated using ion chromatography with conductivity detection. A market sampling of cheese samples purchased in the Washington DC metro area was performed. In 64 samples of cheese, concentrations ranged from below the method detection limit (MDL) to 26 mg kg-1 for nitrates and no concentrations of nitrites were found in any of the cheese samples above the MDL of 0.1 mg kg-1. A majority of the samples (93%) had concentrations below 10 mg kg-1, which indicate the presence of endogenous nitrates. The samples with concentrations above 10 mg kg-1 were mainly processed cheese spread, which can contain additional ingredients often of plant-based origin. These ingredients are likely the cause of the elevated nitrate concentrations. The analysis of 12 additional cheese samples that are liable to the intentional addition of nitrates, 9 of which were imported, indicated that in this limited study, concentrations of nitrate in the U.S.-produced cheeses did not differ from those in imported samples.

Investigation into perfluoroalkyl substances (PFASs) in a cranberry bog: method development and sampling results.

The contamination of groundwater and surface water from previous uses of perfluoroalkyl substances (PFASs), particularly products containing the contaminants perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), has become a concern for drinking water and as a potential exposure route to the food supply. In 2016, the Food and Drug Administration (FDA) was asked to investigate a bog in Massachusetts where the surface water was believed to be contaminated with PFASs. As a result, a method was developed for the analysis of PFASs in cranberries, and water and fruit from the affected bog were evaluated. A QuEChERS method was developed and validated for PFOA, PFOS, and six additional shorter-chain PFASs. Method recoveries ranged from 60% to 115% for validation spikes performed at 10, 20 and 40 ng g-1 and method detection limits ranged from 0.2 to 5.6 ng g-1. Bog water samples were analysed using Environmental Protection Agency (EPA) method 537 for PFOA, PFOS and four additional short-chain PFASs. Surface water concentrations for PFOS ranged from 16 to 122 ng L-1 and input water concentrations were 132 ng L-1 and 206 ng L-1. Of the eight water samples, seven had water concentrations that exceeded the EPA health advisory level for PFOS of 70 ng L-1. Of the 42 cranberry samples analysed, none had detects of PFOA or PFOS above their method detection limits (0.4 and 0.5 ng g-1, respectively), nor any of the other short-chain PFASs.