Long non-coding RNA (lncRNA) DANCR has been reported to participate in key processes such as stem cell differentiation and tumorigenesis. In a high throughput screening for lncRNAs involved in Doxorubicin-induced apoptosis, we found DANCR was suppressed by Doxorubicin and it acted as an important repressor of apoptosis in colorectal cancer. Further studies demonstrated that DANCR promoted the oncogenic lncRNA MALAT1 expression via enhancing the RNA stability of MALAT1 to suppress apoptosis. MALAT1 could efficiently mediate the suppressive function of DANCR on apoptosis. Mechanistic studies found the RNA-binding protein QK served as an interacting partner of both DANCR and MALAT1, and the protein level of QK was subjected to the regulation by DANCR. Furthermore, QK was able to modulate the RNA stability of MALAT1, and the interaction between QK and MALAT1 was controlled by DANCR. In addition, QK could mediate the function of DANCR in regulating the expression of MALAT1 and suppressing apoptosis. These results revealed DANCR played a critical role in Doxorubicin-induced apoptosis in colorectal cancer cells, which was achieved by the interaction between DANCR and QK to enhance the expression of MALAT1.
27 January 2021 in International journal of legal medicine
Cell-free fetal DNA (cffDNA) from maternal plasma has made it possible to develop noninvasive prenatal paternity testing (NIPPT). However, most studies have focused on customized single nucleotide polymorphism (SNP) typing systems and few have used conventional short tandem repeat (STR) markers. Based on massively parallel sequencing (MPS), this study used a widely-accepted forensic multiplex assay system to evaluate the effect of noninvasive prenatal paternity testing with a combination of well-established SNP and STR markers. Using a ForenSeq DNA Signature Prep Kit, NIPPT was performed in 17 real parentage cases with monovular unborn fetuses at 7 to 24 gestational weeks. Different analytical strategies for the identification of paternally inherited allele (PIA) were developed to deal with SNPs and STRs. Combined paternity index (CPI) for 17 real trios as well as 272 unrelated trios was calculated. With the combination of SNPs and A-STRs, 82.35% (14/17), 88.24% (15/17), 94.12% (16/17), and 94.12% (16/17) of real trios could be accurately determined when the likelihood ratio (LR) threshold for paternity inclusion was set to 10,000, 1000, 100, and 10, respectively. This reveals that simultaneous surveys of SNP and STR markers included in the ForenSeq DNA Signature Prep Kit offer a promising method for NIPPT using MPS technology.
Mitochondrial DNA (mtDNA) is an effective genetic marker in forensic practice, especially for aged bones and hair shafts. Detection of the whole mitochondrial genome (mtGenome) using traditional Sanger-type sequencing is laborious and time-consuming. Additionally, its ability to distinguish point heteroplasmy (PHP) and length heteroplasmy (LHP) is limited. The application of massively parallel sequencing in mtDNA detection helps researchers to study the mtGenome in-depth. The ForenSeq mtDNA Whole Genome Kit, which contains a total of 245 short amplicons, is one of the multiplex library preparation kits for the mtGenome. We used this system to detect the mtGenome in the blood samples and hair shafts of thirty-three individuals from eight two-generation pedigrees, one three-generation pedigree, and one four-generation pedigree. High-quality sequencing results were obtained. Ten unique mtGenome haplotypes were observed in the mothers from the ten pedigrees. A total of 26 PHPs were observed using the interpretation threshold of 6%. Eleven types of LHPs in six regions were evaluated in detail. When considering homoplasmic variants only, consistent mtGenome haplotypes were observed between the twice-sequenced libraries and between the blood and hair shafts from the same individual and among maternal relatives in the pedigrees. Four inherited PHPs were observed, and the remainder were de novo/disappearing PHPs in the pedigrees. Our results demonstrate the effective capability of the ForenSeq mtDNA Whole Genome Kit to generate the complete mtGenome in blood and hair shafts, as well as the complexity of mtDNA haplotype comparisons between different types of maternal relatives when heteroplasmy is considered.
Aim: To evaluate the 23 autosomal short tandem repeat (STR) loci included in GoldenEye™ 25 A kit using forensic human identification and paternity testing. Subjects and methods: In total, 3751 unrelated individuals from the Southern Chinese Han population were genotyped with the 5-dye GoldenEye™ 25 A multiplex amplification system. PCR products were separated using arrayed capillary electrophoresis. Allele frequencies and forensic parameters for the 23 autosomal STR loci were statistically analysed. Results: A total of 344 alleles were observed, with corresponding allelic frequencies ranging from 0.0001–0.5519 for the 23 STR loci. No significant deviation from the Hardy-Weinberg equilibrium and linkage disequilibrium was observed. The combined power of discrimination (CPD) was 1–1.6290 × 10−28 and the combined power of exclusion (CPE) was 0.999 999 999 89 and 0.999 999 286 93 for trio and duo cases, respectively. From 3865 meioses, 87 mutation events were discovered. The mutation rate varied from 0–0.00285 for each locus. One-step mutation accounted for 94.25% of total mutations. The ratio of paternal vs maternal mutation was 3.76:1.13 kinds of n/(n + 1) heterozygote genotypes were observed. Conclusions: The results show that 23 STR loci of GoldenEye™ 25 A kit are highly polymorphic in the Southern Chinese Han population, indicating the kit is suitable for forensic application.