Developmental validation of a novel 8-dye fluorescent typing system with 59 Y-STRs and 3 Y-indels for forensic applications.

An 8-dye fluorescence-labeling forensic Y-chromosomal short tandem repeats (Y-STRs) kit, the 62-plex Y-STR multiplex amplification system, was developed and optimized. The system was validated by testing PCR conditions, stutter ratios (SR) and peak height ratios, sensitivity, mixture samples, precision and accuracy, species-specificity, and inhibition studies according to the Scientific Working Group on DNA Analysis Methods guidelines. PCR-based studies showed that the recommended PCR conditions were optimized for this kit. In the sensitivity study, a full profile was obtained from template DNA with a quantity of u125 pg. Consistent profiles were obtained from three different laboratories. The SRs in all loci were less than 15%, and nice balance and suitable average peak height were shown. No peaks were detected in the profiles of common animal species and microorganisms. In the male-male mixture studies, all loci were observed at a ratio of 1:8, and in the male-female mixture study, all alleles could be profiled at a ratio of 1:500 if the male DNA inputs were ≥0.5 ng/µL. An inhibitor study demonstrated that the kit had varying degrees of resistance to the presence of common inhibitors. Population study demonstrated the 62-plex Y-STR Kit improved the power of discrimination in unrelated Chinese Han males (n = 192). When haplotype diversity was 1, the probability of discrimination power of the 62-plex Y-STR Kit was 0.9948, which is suitable for forensic investigations. The results show that the developed 8-dye fluorescence labeling 62 loci system is sensitive, robust, convenient, and highly informative for forensic applications.

Improving the regional Y-STR haplotype resolution utilizing haplogroup-determining Y-SNPs and the application of machine learning in Y-SNP haplogroup prediction in a forensic Y-STR database: A pilot study on male Chinese Yunnan Zhaoyang Han population.

Improving the resolution of the current widely used Y-chromosomal short tandem repeat (Y-STR) dataset is of great importance for forensic investigators, and the current approach is limited, except for the addition of more Y-STR loci. In this research, a regional Y-DNA database was investigated to improve the Y-STR haplotype resolution utilizing a Y-SNP Pedigree Tagging System that includes 24 Y-chromosomal single nucleotide polymorphism (Y-SNP) loci. This pilot study was conducted in the Chinese Yunnan Zhaoyang Han population, and 3473 unrelated male individuals were enrolled. Based on data on the male haplogroups under different panels, the matched or near-matching (NM) Y-STR haplotype pairs from different haplogroups indicated the critical roles of haplogroups in improving the regional Y-STR haplotype resolution. A classic median-joining network analysis was performed using Y-STR or Y-STR/Y-SNP data to reconstruct population substructures, which revealed the ability of Y-SNPs to correct misclassifications from Y-STRs. Additionally, population substructures were reconstructed using multiple unsupervised or supervised dimensionality reduction methods, which indicated the potential of Y-STR haplotypes in predicting Y-SNP haplogroups. Haplogroup prediction models were built based on nine publicly accessible machine-learning (ML) approaches. The results showed that the best prediction accuracy score could reach 99.71% for major haplogroups and 98.54% for detailed haplogroups. Potential influences on prediction accuracy were assessed by adjusting the Y-STR locus numbers, selecting Y-STR loci with various mutabilities, and performing data processing. ML-based predictors generally presented a better prediction accuracy than two available predictors (Nevgen and EA-YPredictor). Three tree models were developed based on the Yfiler Plus panel with unprocessed input data, which showed their strong generalization ability in classifying various Chinese Han subgroups (validation dataset). In conclusion, this study revealed the significance and application prospects of Y-SNP haplogroups in improving regional Y-STR databases. Y-SNP haplogroups can be used to discriminate NM Y-STR haplotype pairs, and it is important for forensic Y-STR databases to develop haplogroup prediction tools to improve the accuracy of biogeographic ancestry inferences.

Title: Developmental validation of Y-SNP pedigree tagging system: A panel via quick ARMS PCR.

The Y chromosomal short tandem repeats (Y-STRs) have been used widely to establish paternal relatedness and examine sub-structures in different geographical regions. However, the applications of Y-STRs showed their limitations when it comes to resolving the complicated relationships within close relatives or among unrelated individuals from different geographic areas. Here, we overcome these limitations by introducing a new strategy for Y-SNP multiplex typing using rapid ARMS (amplification-refractory mutation system) PCR. Newly developed Y-SNP Pedigree Tagging System is able to profile 24 Y-SNPs in a single reaction while the whole process takes 4-5 hours. The panel precisely defines the 11 haplogroups (E-M96, D-JST021355, N-M231, C-M130, O-P186, I-M170, IJ-M429, K-M9, QR-M45, G-M201, and IJK-M522) and 13 sub-haplogroups (D1a1a1-N1, D1a2a-P47, C2-M217, N1a1-M46, O1a-M119, O1b-M268, O1b2-M176, O2-M122, O2a1-KL1, O2a2-P201, O2a2b-P164, O2a2a1a2-M7 and O2a2b1a1-M117). This system could contribute to providing the haplogroup affiliation of unknown pedigree and resolving the sub-structures of East Asian populations. In this study, the multiplex system was validated for: ability to detect degraded DNA, sensitivity, species specificity, reproducibility/repeatability, stability, performance in different scenarios, mixture studies, PCR amplification conditions, and population surveys. The Y-SNP information showed a consistent pattern within 40 father-son or brother-brother pairs. The results of this multiplex system showed the different distribution patterns of male donors from two Chinese Han populations. In this study, we try to discriminate the suspect's pedigree on the level of Y-SNP haplogroups. These results show that Y-SNP Pedigree Tagging System is a robust and reliable amplification kit which can be used for male haplogroup determination.

Genome-wide screening for highly discriminative SNPs for personal identification and their assessment in world populations.

The applications of DNA profiling aim to identify perpetrators, missing family members and disaster victims in forensic investigations. Single nucleotide polymorphisms (SNPs) based forensic applications are emerging rapidly with a potential to replace short tandem repeats (STRs) based panels which are now being used widely, and there is a need for a well-designed SNP panel to meet such challenge for this transition. Here we present a panel of 175 SNP markers (referred to as Fudan ID Panel or FID), selected from ∼3.6 million SNPs, for the application of personal identification. We optimized and validated FID panel using 729 Chinese individuals using a next generation sequencing (NGS) technology. We showed that the SNPs in the panel possess very high heterozygosity as well as low within- and among-continent differentiations, enabling FID panel exhibit discrimination power in both regional and worldwide populations, with the average match probabilities ranging from 4.77×10-71 to 1.06×10-64 across 54 world populations. With the advent of biomedical research, the SNPs connecting physical anthropological, physiological, behavioral and phenotypic traits will be eventually added to the forensic panels that will revolutionize criminal investigation.

Screening of the LTBP2 gene in 214 Chinese sporadic CYP1B1-negative patients with primary congenital glaucoma.

PURPOSE: To identify deleterious mutations in the latent transforming growth factor-ß-binding protein 2 (LTBP2) gene in sporadic patients with primary congenital glaucoma (PCG) from a Han Chinese population, which had been excluded for mutations in the CYP1B1 gene. METHODS: In this retrospective case-control study, 36 coding exons and adjacent exon-intron boundaries of LTBP2 were amplified with PCR and screened for mutations with Sanger sequencing in DNA samples of 214 sporadic patients with PCG. Sequence variants identified in the patients with PCG were subsequently screened in 100 unaffected control subjects and the unaffected parents of the patients with PCG who had sequence changes in LTBP2. RESULTS: Eight heterozygous single nucleotide polymorphisms (SNPs) in coding regions of LTBP2 were identified in the patients with PCG. Four of these SNPs were missense changes that resulted in the replacement of amino acids (rs2304707, rs116914994, rs45468895, and rs763035721), two of which (rs2304707 and rs116914994) were also present in the control subjects. No significant differences in the frequencies of the missense SNPs were found between the patients with PCG and the controls. The two missense SNPs, rs45468895 and rs763035721, which were each found in one patient also existed in their unaffected parents, suggesting that these two SNPs were not segregated in these families and are unlikely to be a disease-causative variant. In addition, four synonymous SNPs were detected in the patients with PCG (rs61738025, rs862031, rs199805158, and rs12586758). CONCLUSIONS: The results showed that no deleterious mutations were found in coding regions of LTBP2 in patients with PCG, suggesting that it is not a causal gene for PCG in the Han Chinese population.

A genetic variant of the NTCP gene is associated with HBV infection status in a Chinese population.

BACKGROUND: To investigate whether genetic variants of the HBV receptor gene NTCP are associated with HBV infection in the Han Chinese population. METHODS: We sequenced the entire 23 kb NTCP gene from 111 HBeAg-positive HBsAg carriers (PSE group), 110 HBeAg-negative HBsAg carriers (PS group), and 110 control subjects. Then, we performed association analyses of suggestively significant SNPs with HBV infection in 1075 controls, 1936 PSs and 639 PSEs. RESULTS: In total, 109 rare variants (74 novel) and 38 single nucleotide polymorphisms (SNPs, one novel) were screened. Of the seven non-synonymous rare variants, six were singletons and one was a double hit. All three damaging rare singletons presented exclusively in the PSE group. Of the five SNPs validated in all 3650 subjects, the T allele of rs4646287 was significantly decreased (p = 0.002) in the PS group (10.1%) and PSE group (8.1%) compared to the controls (10.9%) and was decreased to 7.4% in the PSE hepatocellular carcinoma (HCC) subgroup. Additionally, rs4646287-T was associated with a 0.68-fold (95% CI = 0.51-0.89, p = 0.006) decreased risk of PSE compared with the controls. The NTCP mRNA level was lower in HCC tissues in "CT + TT" carriers than in "CC" carriers. CONCLUSIONS: We found a genetic variant (rs4646287) located in intron 1 of NTCP that may be associated with increased risk of HBV infection in Han Chinese.

Genetic polymorphisms of 18 short tandem repeat loci in 3550 individuals from the Han population of Changchun, Northeast China.

In this study, we analyzed 18 autosomal STRs on 3550 unrelated individuals collected from the Han population of Changchun. No significant deviation from Hardy-Weinberg equilibrium was observed at all STR loci, and the expected heterozygosity ranged from 0.6275 to 0.9207. The combined match probability (CMP) was 2.42 × 10- 22, and the combined power of discrimination (CPD) was 99.9999999999999999999758 %. Changchun Han showed no significant difference between northern and eastern Han populations at nearly all STR loci, but had significant differences between southern Han at multiple STRs, as well as other Chinese ethnic populations. The phylogenetic analysis also showed that Changchun Han is genetically close to northern Hans, suggesting that the Han population of Changchun could mainly come from northern China.

Population genetic analysis of the GlobalFiler STR loci in 748 individuals from the Kazakh population of Xinjiang in northwest China.

The six-dye GlobalFiler™ Express PCR amplification kit incorporates 21 commonly used autosomal short tandem repeat (STR) loci and three gender determination loci. In this study, we analyzed the GlobalFiler STR loci on 748 unrelated individuals from a Chinese Kazakh population of Xinjiang, China. No significant deviations from Hardy-Weinberg equilibrium and linkage disequilibrium were observed within and between 21 autosomal STR loci. SE33 showed the greatest power of discrimination in Kazakh population. The combined power of discrimination of Kazakh was 99.999999999999999999999996797 %. No significant differences of allele frequencies were observed between Kazakh and Uyghur at all 15 tested STR loci, as well as Mongolian. Significant differences were only observed between Kazakh and the other Chinese populations at TH01. Multiple STR loci showed significant differences between Kazakh and Arab, as well as South Portuguese. The multidimensional scaling plot (MDS) plot and neighbor-joining tree also showed Kazakh is genetically close to Uyghur.

Genetic analysis of 17 Y-STR loci in Han and Korean populations from Jilin Province, Northeast China.

In this study, 17 Y chromosomal short tandem repeats (Y-STRs) were analyzed in 302 male individuals from the Chinese Han and Korean populations of Jilin Province. The haplotype diversities of two populations reached 0.99969 and 0.99874, respectively. The Jilin Han and Korean populations differed from each other significantly. The Jilin Han population showed no significant difference from almost any other Han population, but it did show significant differences from most other Chinese ethnic populations. The haplotype frequencies in the Jilin Korean population studied here showed significant differences from all reference populations in earlier reports. These data provide a reference for the Y-STR database in Jilin Province, and they may be valuable for population genetic analysis.

Forensic and population genetic analysis of Xinjiang Uyghur population on 21 short tandem repeat loci of 6-dye GlobalFiler™ PCR Amplification kit.

Estimating the allele frequencies and forensic statistical parameters of commonly used short tandem repeat (STR) loci of the Uyghur population, which is the fifth largest group in China, provides a more precise reference database for forensic investigation. The 6-dye GlobalFiler™ Express PCR Amplification kit incorporates 21 autosomal STRs, which have been proven that could provide reliable DNA typing results and enhance the power of discrimination. Here we analyzed the GlobalFiler STR loci on 1962 unrelated individuals from Chinese Uyghur population of Xinjiang, China. No significant deviations from Hardy-Weinberg equilibrium and linkage disequilibrium were detected within and between the GlobalFiler STR loci. SE33 showed the greatest power of discrimination in Uyghur population, whereas TPOX showed the lowest. The combined power of discrimination was 99.999999999999999999999998746%. No significant difference was observed between Uyghur and the other two Uyghur populations at all tested STRs, as well as Dai and Mongolian. Significant differences were only observed between Uyghur and other Chinese populations at TH01, as well as Central-South Asian at D13S317, East Asian at TH01 and VWA. The phylogenetic analysis showed that Uyghur is genetically close to Chinese populations, as well as East Asian and Central-South Asian.

Estrogen receptor ß agonist enhances temozolomide sensitivity of glioma cells by inhibiting PI3K/AKT/mTOR pathway.

Glioma is the most common primary brain tumor among adults. Temozolomide (TMZ) is widely used as the first­line postsurgical drug for malignant glioma. However, the therapeutic efficacy of TMZ remains ineffective as inherited or acquired drug resistance is frequently observed. Estrogen receptor ß (ERß) has emerged as a tumor suppressor and a key regulator of signal transduction in glioma cells. However, little is known about the role of ERß in regulating the chemotherapeutic response to TMZ. In the current study, the TMZ­resistant U138 glioma cells were treated with the novel ERß agonist liquiritigenin (Liq). It was observed that Liq significantly enhanced ERß expression and sensitized glioma cells to TMZ­induced proliferation inhibition. As a potential mechanism, it was noted that Liq treatment significantly inhibited the activity of the PI3K/AKT/mTOR pathway, which played a protective role against the TMZ­induced cytotoxicity. In addition, it was demonstrated that ERß knockdown or activation of the phosphatidylinositol­4,5­bisphosphate 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway by insulin­like growth factor 1 both eradicated the function of Liq. These results suggest that Liq treatment enhances glioma cell susceptibility to TMZ by inhibiting the PI3K/AKT/mTOR pathway. As hyperactivation of the PI3K/AKT/mTOR pathway is frequently observed in gliomas, the combined use of ERß agonists may become a feasible therapy option to overcome chemoresistance to TMZ.

CYP1B1 genotype influences the phenotype in primary congenital glaucoma and surgical treatment.

AIMS: The aim of the present work was to investigate CYP1B1 gene mutations in patients of Han Chinese ethnicity with primary congenital glaucoma (PCG), and explore the clinical characteristics associated with operative effects. METHODS: Peripheral blood genomic DNA was extracted from patients with PCG to act as a PCR template. CYP1B1 mutations were identified from the amplified coding sequences of CYP1B1. A total of 238 patients, including 116 patients described previously, were used to examine the CYP1B1 mutation frequency. Of the 238 patients, 192 patients (306 eyes) who underwent first operative treatment from January 1991 to September 2007 in the Eye, Ear, Nose & Throat Hospital of Fudan University were analysed to investigate the relationship between clinical characteristics (including CYP1B1 mutation status) and surgical effect via statistical analyses (multivariate logistic regression and Cox regression). RESULTS: The frequency of CYP1B1 mutation carriers in Chinese patients with PCG is 17.2%, and nine novel CYP1B1 mutations were discovered. The median of onset age for patients with CYP1B1 mutations (2 months) is earlier than in patients without mutations (6 months). We identified that the mutant CYP1B1 gene, as well as poorer corneal transparency, was associated with better surgical outcome. CONCLUSIONS: Patients with CYP1B1 mutations tend to have a higher operative success rate in terms of better intraocular pressure control effect. The combination of the CYP1B1 genotype (with or without mutations) and preoperative corneal opacity score can partially predict the outcome of PCG surgery.

High-mobility group A1 proteins enhance the expression of the oncogenic miR-222 in lung cancer cells.

High-mobility group A1 (HMGA1) is a non-histone chromatin protein that has the ability to regulate the transcriptional activity of many genes. Overexpression of HMGA1 is associated with malignant cellular behavior in a range of human cancers but the underlying mechanism is largely unknown. Here we showed that in a cohort of non-small cell lung cancer (NSCLC) tumors, HMGA1 overexpression was immediately associated with enhanced expression of an oncogenic miRNA, namely, miR-222. Chromatin immunoprecipitation (CHIP) assay revealed that HMGA1 directly binds to the proximal promoter of miR-222 in NSCLC cells. We further showed that HMGA1 silencing reduced miR-222 transcriptional activity, whereas forced HMGA1 expression increased it, indicating that miR-222 is directly regulated by HMGA1. Based on in silico prediction, one of the putative targets of miR-222 is phosphatase 2A subunit B (PPP2R2A) which inhibits Akt phosphorylation (p-Akt). We demonstrated that miR-222 inhibited protein expression of PPP2R2A in NSCLC cells by directly interacting with its 3'-UTR region, leading to an obvious increase of p-Akt. HMGA1 silencing augmented PPP2R2A protein expression and inhibited Akt signaling, resulting in significantly retarded cell growth response to IGF-I. These results suggested that HMGA1 is a positive regulator of miR-222, and HMGA1 overexpression might contribute to dysregulation of Akt signaling in NSCLC.

Confirmation and further mapping of the GLC3C locus in primary congenital glaucoma.

We investigated the relationship between primary congenital glaucoma (PCG) in the Chinese Han population and its candidate locus GLC3C. 152 nuclear families (patients with normal parents) without carrying the CYP1B1 mutation were enrolled. Fluorescence Labeled Multiplex-PCR was used to genotype 12 short tandem repeats (STRs) within GLC3C region and transmission disequilibrium test (TDT) was used to analyze the association between PCG and these STR markers. Sixteen haplotype tag single nucleotide polymorphisms (htSNPs) were chosen from the location where the TDT tests showed positive results. Matrix-assisted laser desorption/ionization Time-of-flight (MALDI-TOF) mass spectrometry was used to perform SNP genotyping Haplotypes constructed from these SNPs were analyzed. The TDT results of STRs in the GLC3C area indicated that D14S279, D14S555 and D14S74 have significant transmission disequilibrium signals (p=0.0210, 0.0096 and 0.0034), with a genetic distance of 0.006 cM among them. Significant transmission disequilibrium (P=0.0010) occurred between the haplotype TAACG of rs2111701- rs4020123- rs4903696- rs11159318- rs177216 and the disease. Detection of disease causing genes within this region needs further study.