[Mechanism of PLOD2 induced osimertinib resistance in non-small cell lung cancer HCC827 cells]

Objective: To investigate the effects of osimertinib on proliferation, migration and invasion of procollagen-lysine 2-oxoglutarate 5-dioxygenase 2 (PLOD2) overexpressing HCC827 cells and explore the potential mechanism of PLOD2 induced osimertinib resistance. Methods: We transfected HCC827 cells with LV-vector and LV-over/PLOD2. The expression of PLOD2 was detected by quantitative real time polymerase chain reaction (qRT-PCR) and western blotting. The effects of osimertinib on the proliferation of HCC827-vector and HCC827-PLOD2 cells were evaluated by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) assay. The effects of osimertinib on the migration and invasion of HCC827-vector and HCC827-PLOD2 cells were determined by Transwell assays. The expressions of E-cadherin and vimentin in cells were detected by immunofluorescence (IF). The expressions of epithelial-mesenchymal transition (EMT), FAK-PI3K/AKT and MAPK signal pathway related proteins were detected by western blotting. Results: The MTT assay showed that HCC827-PLOD2 cells were hyposensitive to osimertinib. The 50% inhibitory concentration (IC(50)) and resistance index of osimertinib for HCC827-PLOD2 cells was over 1 000 nmol/L and over 100, respectively. The result of wound healing assay showed that the migration distance of HCC827-PLOD2 was about (2.13±0.21) fold changes as that of HCC827-vector cells. The result of Transwell assay showed that the numbers of HCC827-PLOD2 passing through the matrix membrane were (212.78±10.43), significantly higher than (101.32±12.52) of HCC827-vector cells (P<0.01). The result of IF showed that compared with HCC827-vector cells, the expression of E-cadherin was down-regulated while vimentin was up-regulated in HCC827-PLOD2 cells. Osimertinb downregulated E-cadherin and upregulated vimentin expression in HCC827-vector cells but had limited effect in HCC827-PLOD2 cells. The result of western blotting showed that PLOD2 significantly increased vimentin expression level while decreased E-cadherin expression level. Osimertinib inhibited the expression of p-EGFR, but did not affect the expressions of PLOD2, p-FAK, p-AKT, p-ERK, vimentin and E-cadherin in HCC827-PLOD2 cells. Conclusion: PLOD2 confers resistance to osimertinib in HCC827 cells by regulating EMT, FAK-PI3K/AKT and MAPK signal pathways.

Genetic diversity of rhg1 and Rhg4 loci in wild soybeans resistant to soybean cyst nematode race 3

Over-utilization of germplasms that are resistant to the soybean cyst nematode (SCN) in soybean breeding programs can lead to genetic vulnerability in resistant cultivars. Resistant wild soybean (Glycine soja) is considered an invaluable gene source for increasing the genetic diversity of SCN resistance. In this study, we genotyped 23 G. soja accessions that are resistant to SCN race 3 for polymorphisms in the resistance genes, rhg1, Rhg4, and SHMT, and investigated their genetic relationship with eight Glycine max resistant cultivars. We identified 89 single nucleotide polymorphisms (SNPs) and 11 DNA insertion-deletions (InDels), of which 70 SNPs and 8 InDels were found in rhg1, 9 SNPs were found in Rhg4, and 10 SNPs and 3 InDels were found in SHMT. Nucleotide diversity was π = 0.00238 and θ = 0.00235, and haplotype diversity was 1.000. A phylogenetic tree comprising four clusters was constructed using sequence variations of the 23 G. soja and 8 G. max resistant accessions. Five G. soja accessions in subcluster A2, and four G. soja accessions in cluster B were genetically distant from G. max genotypes. Eight resistance-associated SNPs in the three resistance genes formed nine haplotypes in total. G. soja resistant accessions had different haplotypes (H2, H4, H5, H6, H7, and H8) compared with those of G. max (H1, H3, and H9). These results provide vital information on the use of wild soybeans for broadening the genetic base of SCN resistance.

Genome-wide identification and expression analysis of the CPP-like gene family in soybean

Cysteine-rich polycomb-like protein (CPP-like) genes are a group of transcription factors with highly conserved cysteine-rich domains and are widely distributed in animals and plants, but do not present in yeast. Previous studies have shown that members of this family play important roles in the development of reproductive tissue and in the control of cell division in plants. In this study, whole genome identification of soybean CPP transcription factors was performed using bioinformatic methods. The results showed that there were 20 CPP transcription factors in the soybean genome, which encoded for 28 distinct CPP proteins. These transcription factors were distributed on 16 of 20 chromosomes. Phylogenetic relationship analysis showed that expression of CPP gene family members occurred before the differentiation of monocotyledons and dicotyledons. RNA-Seq analysis showed that 5 genes were highly expressed in all tissues, including Glyma10g39080, Glyma01g44670, Glyma101g66920, Glyma02g01540, and Glyma20g28740. One gene (Glyma14g14750) was specifically expressed in young leaves, while 2 genes (Glyma02g01540 and Glyma10g01580) were highly expressed in root nodules. Quantitative reverse transcriptase-polymerase chain reaction analysis revealed that the expression levels of most genes increased in the roots under high temperature stress. Our findings indicate that these genes are not only involved in growth and development, but also in the responses to high temperature stress in soybean roots.

Genotoxicity of drinking water from Chao Lake

Genotoxic activity appears to originate primarily from reactions of chlorine with humic substances in the source waters. Comparisons of extracts of settled versus chlorinated water have confirmed that chlorinating during water treatment produces mutagenic activity in the mutagenicity tests. Present work on XAD-2 extracts of raw, chlorinated (treated), and settled water from the Chao Lake region of China has involved a battery of mutagenicity assays for various genetic endpoints: the Salmonella test, the sister-chromatid exchange (SCE) induction in Chinese hamster lung (CHL) cells, and the micronucleus (MN) induction in the peripheral blood erythrocytes of silver carp. Extracts of raw and treated water but not the settled water are mutagenic in the Salmonella assay. On the other hand, extracts of three water samples show activity in the SCE and MN assays, especially the raw and treated water. These data show that contamination and chlorinating contribute mutagens to drinking water and suggest that the mammalian assays may be more sensitive for detecting mutagenicity in aquatic environment than the Salmonella test.

Isolation of Corynebacterium pseudotuberculosis from the cervical canal of clinically normal sows

Two isolates from the cervical canal of clinically normal sows were indistinguishable from Corynebacterium pseudotuberculosis in their biochemical properties and genetic homology by DNA-DNA hybridisation. Furthermore, three sheep inoculated with one of the isolates developed typical lesions of caseous lymphadenitis and gave antibody responses specifically to C pseudotuberculosis.

Selective medium containing fosfomycin, nalidixic acid, and culture supernatant of Rhodococcus equi for isolation of Corynebacterium pseudotuberculosis

FNR medium containing fosfomycin, nalidixic acid, bovine blood and culture supernatant of Rhodococcus equi was prepared by the present authors, and the medium did not inhibit growth of Corynebacterium pseudotuberculosis but completely hampered the growth of Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. The culture supernatant of R. equi facilitated detection of suspected colonies of C. pseudotuberculosis due to synergistic hemolysis. Rate of isolation of the organisms (from the trachea, larynx and nasal cavity of 16 slaughtered sheep with caseous abscess in the lung) was higher with FNR, the selective medium, than with nonselective medium. The selective medium was thus found to be useful for isolation of C. pseudotuberculosis from sheep.

Seroepidemiological survey of Corynebacterium pseudotuberculosis infection in sheep in Japan using enzyme-linked immunosorbent assay and immunodiffusion

Sera from 1186 apparently healthy sheep in Hokkaido were examined by enzyme-linked immunosorbent assay (ELISA) and immunodiffusion (ID) for the presence of antibodies against Corynebacterium pseudotuberculosis. ELISA-positives were 466 (39.3%) while ID-positives were 330 (27.8%). Spread of caseous lymphadenitis in sheep in Hokkaido was thus clarified. Although ID was less sensitive than ELISA in detecting the antibodies against C. pseudotuberculosis it did not give any non-specific reaction. From the results and in view of the simplicity of the test procedure, ID was found to be of practical diagnostic value. Distribution by age group of anti-C. pseudotuberculosis antibodies in 758 sheep in a herd detected by both tests showed that the ratio of positives was low in sheep aged less than 1 year, and the ratio increased significantly in those aged 1 year and continued to increase with age until it reached a plateau at the age of 4-5 years.