Selective BRAF inhibitors, vemurafenib and dabrafenib, and the MEK inhibitor, trametinib, have been approved for treatment of metastatic melanomas with a BRAF p.V600E mutation. The clinical ...significance of non-codon 600 mutations remains unclear, in part, due to variation of kinase activity for different mutants.
In this study, we categorized BRAF mutations according to the reported mutant kinase activity. A total of 1027 lung cancer, colorectal cancer or melanoma specimens were submitted for clinical mutation detection by next generation sequencing.
Non-codon 600 mutations were observed in 37% of BRAF-mutated tumors. Of all BRAF mutants, 75% were kinase-activated, 15% kinase-impaired and 10% kinase-unknown. The most common kinase-impaired mutant involves codon 594, specifically, p.D594G (c.1781A > G) and p.D594N (c.1780G > A). Lung cancers showed significantly higher incidences of kinase-impaired or kinase-unknown mutants. Kinase-impaired BRAF mutants showed a significant association with concomitant activating KRAS or NRAS mutations, but not PIK3CA mutations, supporting the reported interaction of these mutations.
BRAF mutants with impaired or unknown kinase activity as well as concomitant kinase-impaired BRAF mutations and RAS mutations were detected in lung cancers, colorectal cancers and melanomas. Different therapeutic strategies based on the BRAF mutant kinase activity and the concomitant mutations may be worthwhile.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Using bacteriophages (phages) as environmental sanitizers has been recognized as a potential alternative method to remove bacterial contamination in vitro; however, very few studies are available on ...the application of phages for infection control in hospitals. Here, we performed a 3-year prospective intervention study using aerosolized phage cocktails as biocontrol agents against carbapenem-resistant Acinetobacter baumannii (CRAB) infection in the hospital. When a CRAB-infected patient was identified in an intensive care unit (ICU), their surrounding environment was chosen for phage aerosol decontamination. Before decontamination, 501 clinical specimens from the patients were subjected to antibiotic resistance analysis and phage typing. The optimal phage cocktails were a combination of different phage families or were constructed by next-evolutionary phage typing with the highest score for the host lysis zone to prevent the development of environmental CRAB phage resistance. The phage infection percentage of the antibiotic-resistant A. baumannii strains was 97.1%, whereas the infection percentage in the antibiotic-susceptible strains was 79.3%. During the phage decontamination periods from 2017 to 2019, the percentage of carbapenem-resistant A. baumannii in test ICUs decreased significantly from 65.3% to 55%. The rate of new acquisitions of CRAB infection over the three years was 4.4 per 1000 patient-days, which was significantly lower than that in the control wards (8.9 per 1000 patient-days) where phage decontamination had never been performed. In conclusion, our results support the potential of phage cocktails to decrease CRAB infection rates, and the aerosol generation process may make this approach more comprehensive and time-saving.
•The potential of aerosolized phage cocktails to decrease the infection rates of CRAB was assessed.•The cocktails were generated by next-evolutionary phage typing.•The phage infection percentage of CRAB was higher than that of drug-susceptible strains.•The number and percentage of CRAB were significantly decreased in the test ICUs.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Analysis of melanomas for actionable mutations has become the standard of care. Recently, a classification scheme has been proposed that categorizes BRAF mutations based on their mechanisms for ...activation of the MAPK pathway.
In this analysis BRAF, KIT, NRAS, and PIK3CA mutations were examined by next generation sequencing (NGS) in 446 melanomas in a clinical diagnostic setting. KRAS and HRAS were also analyzed to elucidate coexisting BRAF and RAS mutations. BRAF mutations were categorized into class-1 (kinase-activated, codon 600), class-2 (kinase-activated, non-codon 600) and class-3 (kinase-impaired), based on the newly proposed classification scheme.
NGS demonstrated high analytic sensitivity. Among 355 mutations detected, variant allele frequencies were 2-5% in 21 (5.9%) mutations and 2-10% in 47 (13%) mutations. Mutations were detected in BRAF (42%), NRAS (25%), KIT (4.9%) and PIK3CA (2.7%). The incidence of class-1, class-2 and class-3 mutations were 33% (26% p.V600E and 6.1% p.V600K), 3.1 and 4.9% respectively. With a broader reportable range of NGS, class-1, class-2 and class-3 mutations accounted for 77, 7.4 and 12% of all BRAF mutations. Class-3 mutations, commonly affecting codons 594, 466 and 467, showed a higher incidence of coexisting RAS mutations, consistent with their RAS-dependent signaling. Significant association with old age and primary tumors of head/neck/upper back suggest chronic solar damage as a contributing factor for melanomas harboring BRAF p.V600K or class-3 mutations.
This study categorizes the range, frequency, coexisting driver mutations and clinical characteristics of the three classes of BRAF mutations in a large cohort of melanomas in a clinical diagnostic setting. Further prospective studies are warranted to elucidate the clinical outcomes and benefits of newly developed targeted therapy in melanoma patients carrying each class of BRAF mutation.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In past researches, we had been proved the action mechanism of pre-germinated brown rice (PGBR) to treat metabolic syndrome and diabetes mellitus. This study was to investigate the protective effect ...of PGBR in high fructose and high fat-induced non-alcoholic fatty liver disease (NAFLD) in rodents. WKY rats were divided into: Control group was fed normal drinking water and diet; FLD group was fed 10% high-fructose-water (HFW) and high-fat-diet (HFD); PGBR group was given HFW, and HFD mixed PGBR. After four weeks, the body, hepatic and cardiac weight gains of FLD group had significant increases than that of Control group. The enhanced blood pressure and heart rate, hypertriglyceridemia, hyperuricemia, and higher liver function index (GPT levels) were observed; meanwhile, the IL-6 and TNF-α levels of serum, and TG level of liver were also elevated in FLD group. The related protein expressions of lipid synthesis, inflammation, cardiac fibrosis, and hypertrophy were deteriorated by HFW/HFD. However, in treatment group, PGBR decreased all above influenced parameters, additionally GOT; and related protein expressions. PGBR treated HFW/HFD-induced NAFLD and cardiac complications might be via improving lipid homeostasis, and inhibiting inflammation. Together, PGBR could be used as a healthy food for controlling NAFLD and its’ cardiac dysfunction.
Cancer stem cells (CSCs), characterized by self-renewal and unlimited proliferation, lead to therapeutic resistance in lung cancer. In this study, we aimed to investigate the expressions of stem ...cell-related genes in lung adenocarcinoma (LUAD). The stemness index based on mRNA expression (mRNAsi) was utilized to analyze LUAD cases in the Cancer Genome Atlas (TCGA). First, mRNAsi was analyzed with differential expressions, survival analysis, clinical stages, and gender in LUADs. Then, the weighted gene co-expression network analysis was performed to discover modules of stemness and key genes. The interplay among the key genes was explored at the transcription and protein levels. The enrichment analysis was performed to annotate the function and pathways of the key genes. The expression levels of key genes were validated in a pan-cancer scale. The pathological stage associated gene expression level and survival probability were also validated. The Gene Expression Omnibus (GEO) database was additionally used for validation. The mRNAsi was significantly upregulated in cancer cases. In general, the mRNAsi score increases according to clinical stages and differs in gender significantly. Lower mRNAsi groups had a better overall survival in major LUADs, within five years. The distinguished modules and key genes were selected according to the correlations to the mRNAsi. Thirteen key genes (CCNB1, BUB1, BUB1B, CDC20, PLK1, TTK, CDC45, ESPL1, CCNA2, MCM6, ORC1, MCM2, and CHEK1) were enriched from the cell cycle Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, relating to cell proliferation Gene Ontology (GO) terms, as well. Eight of the thirteen genes have been reported to be associated with the CSC characteristics. However, all of them have been previously ignored in LUADs. Their expression increased according to the pathological stages of LUAD, and these genes were clearly upregulated in pan-cancers. In the GEO database, only the tumor necrosis factor receptor associated factor-interacting protein (TRAIP) from the blue module was matched with the stemness microarray data. These key genes were found to have strong correlations as a whole, and could be used as therapeutic targets in the treatment of LUAD, by inhibiting the stemness features.
IDH1 and IDH2 Mutations in Colorectal Cancers Huang, Jialing; Tseng, Li-Hui; Parini, Vamsi ...
American journal of clinical pathology,
11/2021, Volume:
156, Issue:
5
Journal Article
Peer reviewed
Abstract
Objectives
To elucidate clinicopathologic and molecular characteristics of IDH1 and IDH2 (IDH1/2) mutations in colorectal cancers (CRCs).
Methods
We evaluated IDH1/2 mutations in 1,623 CRCs ...using a next-generation sequencing assay.
Results
IDH1/2 mutations, predominantly IDH1 p.R132C, were detected in 15 (0.9%) CRCs and in 5 (3.0%) of 167 BRAF p.V600E–mutated CRCs. Three IDH1/2-mutated CRCs were associated with inflammatory bowel disease. They were significantly associated with old age, mucinous or signet ring cell adenocarcinoma, and high-grade histomorphology. Concordance of variant allele frequency between IDH1/2 mutants and other trunk drivers in CRCs and presence of IDH1/2 mutation in the adenoma and early adenocarcinoma indicated IDH1/2 mutations could be trunk drivers suitable for targeted therapy.
Conclusions
IDH1/2 mutations in CRCs were uncommon but enriched in BRAF p.V600E–mutated CRCs and perhaps colitis-associated CRCs. Further studies on IDH1/2-mutated CRCs are needed to clarify their clinicopathologic features and implications for targeted therapy.
To validate next-generation sequencing (NGS) technology for clinical diagnosis and to determine appropriate read depth.
We validated the KRAS, BRAF, and EGFR genes within the Ion AmpliSeq Cancer ...Hotspot Panel using the Ion Torrent Personal Genome Machine (Life Technologies, Carlsbad, CA).
We developed a statistical model to determine the read depth needed for a given percent tumor cellularity and number of functional genomes. Bottlenecking can result from too few input genomes. By using 16 formalin-fixed, paraffin-embedded (FFPE) cancer-free specimens and 118 cancer specimens with known mutation status, we validated the six traditional analytic performance characteristics recommended by the Next-Generation Sequencing: Standardization of Clinical Testing Working Group. Baseline noise is consistent with spontaneous and FFPE-induced C:G→T:A deamination mutations.
Redundant bioinformatic pipelines are essential, since a single analysis pipeline gave false-negative and false-positive results. NGS is sufficiently robust for the clinical detection of gene mutations, with attention to potential artifacts.
Abstract
Objectives
To demonstrate clinicopathologic features and evaluate the clonality of double PIK3CA alterations in colorectal cancers (CRCs).
Methods
Clonality was examined in 13 CRCs with ...double PIK3CA alterations (1.7% of CRCs or 9.6% of PIK3CA-mutated CRCs). Multiregional analyses were performed to confirm subclonal PIK3CA alterations.
Results
PIK3CA alterations were detected within exon 9 (51%), exon 20 (23%), exon 1 (15%), and exon 7 (6.0%). CRCs with exon 7 alterations showed a significantly higher incidence of double PIK3CA alterations. Most double PIK3CA alterations consisted of a hotpsot alteration and an uncommon alteration; they were often clonal and present within a single tumor population. Multiregional analyses of CRCs with predicted subclonal double-alterations revealed multiclonal CRCs with divergent PIK3CA variant status originating from a common APC- and KRAS-mutated founder lineage of adenoma.
Conclusions
The findings supported multiclonal CRCs resulting from parallel evolution during the progression from adenoma to adenocarcinoma within the mitogen-activated protein kinase pathway, as previously demonstrated, or the mammalian target of rapamycin pathway. Further studies are warranted to elucidate clinical significance and potential targeted therapy for CRC patients with double PIK3CA alterations and impacts on clinical decision-making in patients with multiclonal CRCs harboring divergent PIK3CA mutational status.
Activating mutations in downstream genes of the epidermal growth factor receptor (EGFR) pathway may cause anti-EGFR resistance in patients with colorectal cancers. We present performance ...characteristics of a next-generation sequencing assay designed to detect such mutations. In this retrospective quality assessment study, we analyzed mutation detected in the KRAS, NRAS, BRAF, and PIK3CA genes by a clinically validated next-generation sequencing assay in 310 colorectal cancer specimens. Tumor cellularity and mutant allele frequency were analyzed to identify tumor heterogeneity and mutant allele-specific imbalance. Next-generation sequencing showed precise measurement of mutant allele frequencies and detected 23% of mutations with 2-20% mutant allele frequencies. Of the KRAS mutations detected, 17% were outside of codons 12 and 13. Among PIK3CA mutations, 48% were outside of codons 542, 545, and 1047. The percentage of tumors with predicted resistance to anti-EGFR therapy increased from 40% when testing for only mutations in KRAS exon 2 to 47% when testing for KRAS exons 2-4, 48% when testing for KRAS and NRAS exons 2-4, 58% when including BRAF codon 600 mutations, and 59% when adding PIK3CA exon 20 mutations. Right-sided colorectal cancers carried a higher risk of predicted anti-EGFR resistance. A concomitant KRAS mutation was detected in 51% of PIK3CA, 23% of NRAS, and 33% of kinase-impaired BRAF-mutated tumors. Lower than expected mutant allele frequency indicated tumor heterogeneity, while higher than expected mutant allele frequency indicated mutant allele-specific imbalance. Two paired neuroendocrine carcinomas and adjacent adenomas showed identical KRAS mutations, but only PIK3CA mutations in neuroendocrine carcinomas. Next-generation sequencing is a robust tool for mutation detection in clinical laboratories. It demonstrates high analytic sensitivity and broad reportable range, and it provides simultaneous detection of concomitant mutations and a quantitative measurement of mutant allele frequencies to predict tumor heterogeneity and mutant allele-specific imbalance.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Detection of coexisting mutations within the same signal transduction pathway, which are expected to be mutually exclusive, raises a concern of laboratory errors. We have previously confirmed the ...presence of different RAS (KRAS and NRAS) mutations in the adenoma and/or adenocarcinoma subpopulations of colorectal cancers (CRCs). In this study, multiregional analyses by next-generation sequencing were conducted to elucidate the mechanisms underlying multiple RAS mutations seen in 5 CRC specimens. Multiregional analyses were initially conducted in a single tissue block originally submitted for mutational profiling. In 2 specimens, mutational status of the APC gene was not identical, indicating collisional adenoma and adenocarcinoma. In 3 specimens, the same APC mutation was present in different subpopulations with divergent RAS mutations, indicating a common clonal origin. Subsequent comprehensive multiregional analyses of additional adenoma and adenocarcinoma components revealed multiclonal CRCs with divergent histomorphological features and RAS mutations originating from a common APC-mutated founder lineage of adenoma, but from different RAS-mutated founder lineages of adenocarcinoma. These findings are consistent with the stepwise model of colorectal tumorigenesis along with parallel evolution, which affects RAS genes within the mitogen-activated protein kinase pathway and occurs during the progression from adenomas to adenocarcinomas. Evaluation of tumor subpopulations with divergent histomorphological features by pathologists may help identify multiclonal CRCs. Further studies are warranted to evaluate the incidence of multiclonality in CRCs and its impact on clinical outcomes. Perhaps, multiclonal CRCs originating from the same APC-mutated founder lineage of adenoma but from different RAS-mutated founder lineages of adenocarcinomas should be defined and managed as separate CRCs.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
PDF
