The present pilot study assessed the usefulness of nanofluidic digital polymerase chain reaction (PCR) arrays in epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma after tyrosine kinase inhibitor (TKI) resistance.We enrolled 12 patients with primary lung adenocarcinoma with sensitive EGFR mutation-confirmed T790M status by re-biopsy after TKI resistance. Nanofluidic digital PCR arrays were used to quantify T790M in genomic DNA from the pre-treatment primary site and in serum cell-free DNA (cfDNA).On digital PCR, quantified T790M at the pre-treatment primary site was higher in re-biopsy-positive T790M patients (n=4) than in re-biopsy-negative patients (n=8) (0.78%±0.36% vs. 0.07%±0.09%, p<0.01). T790M at the pre-treatment primary site correlated with progression-free survival (PFS) after gefitinib therapy (r=0.67, p=0.016).Use of digital PCR to quantify T790M at the primary site of EGFR-mutant lung adenocarcinoma predicted T790M emergence in re-biopsies after TKI resistance and PFS after gefitinib therapy.
Transplantability of mouse tumors superinfected with various kinds of membrane viruses was investigated in syngeneic hosts. Methylcholanthrene-induced fibrosarcomas in BALB/c mice, Meth A, and in C57BL/6 mice, BMT-, superinfected with Friend lymphatic leukemia virus in mice given neonatal injection of the virus, grew more slowly than uninfected tumors. The retardation of growths was not observed in mice that had been given injections of the virus at birth. Similarly, Meth A and a hepatoma in C3H/He mice, MH134, superinfected with Moloney murine sarcoma virus in nu/nu mice, had reduced their transplantability in respective syngeneic mice. Further, Meth A and MH134 superinfected with endogenous rat leukemia virus and human measles virus, respectively, in nu/nu mice also showed reduced transplantability, and some of the former were actually rejected by normal syngeneic hosts. On the other hand, the reduced transplantability was not found in irradiated mice, suggesting that the phenomenon was due to immunological events. However, a myelogenous leukemia in C57BL/6 mice, C1498, superinfected with Moloney sarcoma virus in nu/nu mice grew like uninfected tumor and did not show reduced transplantability at all.
Spontaneous hepatitis associated with severe jaundice occurred in 90% of an inbred strain of Long‐Evans rats. The rapidly progressive syndrome was characterized by abrupt onset, hyperbilirubinemia and increased serum levels of glutamic oxaloacetic transaminase and glutamic pyruvic transaminase, associated with massive and multifocal necrosis of the liver. This strain should provide a useful animal model for analysis of the pathogenesis of fulminant hepatitis in humans. ACTA PATHOL JPN 38: 1369–1375, 1988.
The multidrug resistance-associated protein 3 (MRP3/Mrp3) is a member of the ATP-binding cassette (ABC) protein family of membrane transporters and related proteins that act on a variety of xenobiotic and anionic molecules to transfer these substrates in an ATP-dependent manner. In recent years, useful comparative information regarding evolutionarily conserved structure and transport functions of these proteins has accrued through the use of primitive marine animals such as cartilaginous fish. Until recently, one missing tool in comparative studies with cartilaginous fish was cell culture. We have derived from the embryo of Squalus acanthias, the spiny dogfish shark, the S. acanthias embryo (SAE) mesenchymal stem cell line. This is the first continuously proliferating cell line from a cartilaginous fish. We identified expression of Mrp3 in this cell line, cloned the molecule, and examined molecular and cellular physiological aspects of the protein. Shark Mrp3 is characterized by three membrane-spanning domains and two nucleotide-binding domains. Multiple alignments with other species showed that the shark Mrp3 amino acid sequence was well conserved. The shark sequence was overall 64% identical to human MRP3, 72% identical to chicken Mrp3, and 71% identical to frog and stickleback Mrp3. Highest identity between shark and human amino acid sequence (82%) was seen in the carboxyl-terminal nucleotide-binding domain of the proteins. Cell culture experiments showed that mRNA for the protein was induced as much as 25-fold by peptide growth factors, fetal bovine serum, and lipid nutritional components, with the largest effect mediated by a combination of lipids including unsaturated and saturated fatty acids, cholesterol, and vitamin E.
Metabolic pathways are plastic and rapidly change in response to stress or perturbation. Current metabolic profiling techniques require lysis of many cells, complicating the tracking of metabolic changes over time after stress in rare cells such as hematopoietic stem cells (HSCs). Here, we aimed to identify the key metabolic enzymes that define differences in glycolytic metabolism between steady-state and stress conditions in HSCs and elucidate their regulatory mechanisms. Through quantitative 13C metabolic flux analysis of glucose metabolism using high-sensitivity glucose tracing and mathematical modeling, we found that HSCs activate the glycolytic rate-limiting enzyme phosphofructokinase (PFK) during proliferation and oxidative phosphorylation (OXPHOS) inhibition. Real-time measurement of adenosine triphosphate (ATP) levels in single HSCs demonstrated that proliferative stress or OXPHOS inhibition led to accelerated glycolysis via increased activity of PFKFB3, the enzyme regulating an allosteric PFK activator, within seconds to meet ATP requirements. Furthermore, varying stresses differentially activated PFKFB3 via PRMT1-dependent methylation during proliferative stress and via AMPK-dependent phosphorylation during OXPHOS inhibition. Overexpression of Pfkfb3 induced HSC proliferation and promoted differentiated cell production, whereas inhibition or loss of Pfkfb3 suppressed them. This study reveals the flexible and multilayered regulation of HSC glycolytic metabolism to sustain hematopoiesis under stress and provides techniques to better understand the physiological metabolism of rare hematopoietic cells.
Five new dibenzocyclooctadiene lignans, named gomisin A (2), B (3), C (4), F (5) and G (6), were isolated from the petroleum ether extract of fruits of Schizandra chinensis BAILL. (Schizandraceae) and their absolute structures were elucidated by chemical and spectral techniques. The absolute structure of schizandrin (1), the plane structure of which had already been elucidated by Kochetkov et al., was also elucidated on the basis of spectroscopic results.
