A Multiplex qPCR Gene Dosage Assay for Rapid Genotyping and Large-Scale Population Screening for Deletional α-Thalassemia

Detection of α-thalassemia South-East Asian deletion based on a fully integrated digital polymerase chain reaction system DropXpert S6

OBJECTIVES

This study aimed to establish a droplet digital polymerase chain reaction (ddPCR) assay for South-East Asian (SEA) deletion based on a fully integrated digital PCR system DropXpert S6.

METHODS

A total of 151 whole blood samples, 10 chorionic villus samples, and 17 amniotic fluid samples were collected, including 106 SEA heterozygotes, 43 normal individuals, 10 Hb Bart's hydrops details, and 19 SEA deletions combined with other genotypes.Genotypes of these samples were determined by the Gap-PCR method. We perform a series of optimizations of the ddPCR system to ensure the performance of the entire ddPCR reaction, such as droplet stability, fluorescence clustering, sensitivity, and accuracy.

RESULTS

Our assay exhibited 99.4% (177/178) accuracy compared with the Gap-PCR method, and the minimum detection limit of DNA was 0.1 ng/μL.Both targets have reliable linearity, R2 = 0.9999 for the α-thalassemia SEA deletion allele and R2 = 1 for the wild-type allele. The coefficient of variation for α-thalassemia SEA deletion allele detection at 2 and 10 ng/μL concentrations was 5.42% and 1.91%, respectively. In contrast, the coefficient of variation for wild-type allele detection was 4.06% and 1.83%, demonstrating its high quantitative accuracy. In addition, the DropXpert S6 PCR system showed some advantages over other ddPCR instruments, such as reducing testing costs, simplifying and automating the workflow.

CONCLUSIONS

The DropXpert S6 PCR system provided a highly accurate diagnosis for α-thalassemia SEA deletion and can be used to detect α-thalassemia as an alternative method.

One-step genotyping of α-thalassaemia by multiplex symmetric PCR melting curve

AIMS

Alpha-thalassaemia is one of the most common monogenic disorders worldwide. Due to high guanine-cytosine (GC) content and high mutation diversity in α-globin gene cluster, deletional and non-deletional mutations were usually separately detected with different methods. The aim of this study was to develop a novel one-step method for α-thalassaemia genotyping.

METHODS

A multiplex symmetric PCR melting curve strategy was designed for one-step α-thalassaemia genotyping. Based on this strategy, a novel method was developed to simultaneously detect four common deletional (-α3.7 , -α4.2 , _ _SEA , --THAI ) and five common non-deletional (αCD30(-GAG)α, αCD31(G>A)α, αWSα, αQSα, αCSα) α-thalassaemia mutations in a closed-tube reaction. This method was also evaluated by double-blind detection of 235 genotype-known samples and 1630 clinical samples.

RESULTS

All nine α-thalassaemia mutations could be accurately identified by this novel method within 3 hours. The evaluation results also showed a 100% concordance with comparison methods.

CONCLUSIONS

This method is rapid, accurate, low-cost and easy to operate, which can be used for molecular screening and genetic diagnosis of α-thalassaemia in clinical practice. The multiplex symmetric PCR melting curve strategy designed in this study can also provide an effective approach to the method development for high GC content templates and multiple mutations.

Hematological and genetic profiles of persons with co-inherited heterozygous β-thalassemia and supernumerary α-globin genes

INTRODUCTION

Thalassemias are common monogenic autosomal recessive hemoglobin disorders. The usually asymptomatic heterozygotes (β-thalassemia traits, βTT) may rarely develop non-transfusion-dependent-thalassemia (NTDT) due to co-inheritance of supernumerary α-globin genes. Literature on phenotypic/genotypic features of these rare combinations is limited.

MATERIALS AND METHODS

We studied the demographic, clinical, and laboratory data from 47 persons with co-inherited βTT + supernumerary α-globin genes. HBB mutations were tested for by ARMS-PCR and/or Sanger sequencing, ααα^(anti3.7) /ααα^(anti4.2) and deletional α-thalassemia testing by multiplex gap-PCRs, and Xmn1^G γ genotyping by PCR-RFLP.

RESULTS

The 47 cases comprised 0.08% of 61 010 hemoglobinopathy screenings during the study period. Mean age was 31.9 ± 14.7 years (range 5.5-83 years), with 57.4% males. Thirty (63.8%) had NTDT-phenotype, 16 (34%) were asymptomatic/minimally symptomatic, and 1 became transfusion-dependent at the age of 20 years. Anemia/pallor and jaundice were the commonest complaints (76% each); 40% had required blood transfusions. Twenty-one had splenomegaly, 14 had hepatomegaly. Mean hemoglobin was 9.0 ± 1.9 g/dl (range 4.0-13.0). HbA2 was 5.1 ± 0.7% (3.4%-6.3%) and HbF% 4.2 ± 3.2% (0.5%-18.4%). Forty-four (93.6%) had ααα^anti3.7 , while 3 (6.4%) had ααα^anti4.2 triplications. HBB:c.92+5G>C (47%), HBB:c.27_28insG (14.9%), and HBB:c.47G>A (8.5%) were the commonest β-globin mutations. One case showed HBB:c.-138C>T (β⁺⁺ ), while the rest had β⁰ or severe-β⁺ mutations. Symptomatic cases had significantly lower hemoglobins and higher HbF% than asymptomatic ones.

CONCLUSION

This largest Indian and globally second-largest study reports the βTT + ααα^4.2 state for the first time in such genotypically-complex Indian cases. Supernumerary α-genes should be suspected in all βTT with disproportionate clinical symptoms, mild-to-moderately elevated HbF, and unexplained anisopoikilocytosis.

Inhibition of GPR30 sensitized gefitinib to NSCLC cells via regulation of epithelial-mesenchymal transition

Introduction: G-protein coupled receptor 30 (GPR30) is associated with cell metastasis and drug resistance in many different cancer cells. The present study aimed to reveal the sensitivity of GPR30 to gefitinib in non-small cell lung cancer (NSCLC) cells.Methods: Cell viability and proliferation were detected using cell counting kit 8 and 5-ethynyl-2'-deoxyuridine assays, respectively. Western blotting and quantitative real-time reverse transcription PCR were used to detect GPR30 or epithelial-mesenchyme transition (EMT)-related mRNA and protein expression.Results: The results showed that GPR30 expression is associated with gefitinib sensitivity. G15, as a GPR30 antagonist, reduced GPR30 expression. We chose the maximum concentration of G15 with minimal cytotoxicity to detect cell viability after combined treatment with gefitinib in NSCLC cells, which indicated that G15 could increase sensitivity to gefitinib. However, the effect of G15 on gefitinib sensitivity disappeared after treatment with a small interfering RNA targeting GPR30. Further research showed that G15 or GPR30 siRNA treatment could upregulate E-cadherin and downregulate vimentin levels.Conclusion: Taken together, these data suggested that G15 could enhance NSCLC sensitivity to gefitinib by inhibition of GPR30 and EMT.

Targeted Next-Generation Sequencing Reveals a Large Novel β-Thalassemia Deletion that Removes the Entire HBB Gene

β-Thalassemia (β-thal) is one of the most common monogenic recessive inherited diseases worldwide. The mutation spectrum of β-thal has been increasingly broadened by various genetic testing methods. The discovery and identification of novel and rare pathogenic thalassemia variants enable better disease prevention, especially in high prevalence regions. In this study, a Chinese thalassemia family with an unclear etiology was recruited to the Thalassemia Screening Program. Blood samples collected from them were primarily screened by hematology analysis and clinical routine genetic screening. Subsequently, targeted next-generation sequencing (NGS) and Sanger sequencing were performed to find and identify a novel deletion variant. The deletion, discovered by targeted NGS, was validated through real-time quantitative polymerase chain reaction (qPCR). First, a large novel β-thal deletion (3488 bp) related to a high Hb F level, NC_000011.9: g.5245533_5249020del (Chongqing deletion) (GRCh37/hg19), was found and identified in the proband and her mother. The deletion removed the entire β-globin gene and led to absent β-globin (β⁰). We then validated this large novel deletion in the proband and her mother by qPCR. We first discovered and identified a large novel β-thal deletion related to elevated Hb F level, it helps broaden the spectrum of pathogenic mutants that may cause β-thal intermedia (β-TI) or β-thal major (β-TM), paving the way for effective thalassemia screening. Next-generation sequencing has the potential of finding rare and novel thalassemia mutants.

Clinicopathological and prognostic value of NADPH oxidase 2 (NOX2) in primary osteosarcoma

BACKGROUND

Osteosarcoma is the most common primary malignant bone tumor, particularly among children and adolescents, and the prognosis of osteosarcoma patients remains poor. The NADPH oxidase 2 (NOX2) has been found over-expressed in several human cancers, and closely associated with poor prognosis. Meanwhile the role of NOX2 in osteosarcoma patients has not been reported. This study aimed to investigate the clinicopathological and prognostic significance of NOX2 in osteosarcoma patients.

METHODS

Immunohistochemistry (IHC), western blot (WB) and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were used to detect the expression of NOX2 in 55 primary osteosarcoma specimens and in 20 non-neoplastic bone tissue specimens. The correlations between NOX2 expression and clinicopathological parameters were analysed by using the χ2 test or Fisher's exact test. Disease free survival and overall survival of osteosarcoma patients were assessed by using the Kaplan-Meier method and Cox proportional hazards model.

RESULTS

NOX2 was over-expressed significantly in osteosarcoma compared with that in non-neoplastic bone tissue, and correlated with progression free survival (P < 0.001) and overall survival (P < 0.001). The over-expression of NOX2 was associated with tumor size (P < 0.001), tumor location (P < 0.001). The Cox analysed shown that the over-expression of NOX2 was predicted to be worse PFS (hazard ratio (HR) = 4.10, P = 0.004) and OS (hazard ratio (HR) = 3.50, P = 0.010) time in osteosarcoma patients.

CONCLUSIONS

The results of our study suggest that the over-expression of NOX2 is related to adverse clinical outcome, and can be viewed as an independent prognostic marker in osteosarcoma. Further research is required to verify the predictive value of NOX2 in osteosarcoma patients.

Characterization of a Novel 71.8 kb α0-Thalassemia Deletion and Subsequent Summary of a Practical Procedure for Thalassemia Molecular Diagnosis

Thalassemia is the most common monogenic disorder around the world. Based on the principle of genotype-phenotype correlation, identification of thalassemia mutations is the essential prerequisite for clinical diagnosis and management. Because only common mutations are routinely detected, the identification of rare or undetermined mutations is a challenge for clinical laboratories. Herein, a proband presenting with inconsistent phenotype-genotype correlation after routine molecular screening was investigated by multiplex ligation-dependent probe amplification (MLPA), targeted-next generation sequencing (targeted-NGS), gap-polymerase chain reaction (gap-PCR) and Sanger sequencing. Eventually, a novel 71.8 kb deletion (- -^71.8) was identified and characterized, which included HBZ (ζ), HBA2 (α2), and HBA1 (α1) genes and was causing α⁰-thalassemia (α⁰-thal). Furthermore, we summarized a practical procedure based on accumulated experience in studies and clinical practice, which can be a guide for molecular screening and clinical diagnosis of thalassemia, especially for identification of undetermined or novel mutations.

miR-223-3p reduces high glucose and high fat-induced endothelial cell injury in diabetic mice by regulating NLRP3 expression

Expression levels of miR-223-3p and NLRP3 in high glucose and high fat (HGHF)-induced diabetic mice, and the mechanism on the injury of mouse cardiac microvascular endothelial cells (MCMECs) were investigated. Four-week C57BL/6J laboratory mice were selected and randomized into a control group and a model group (n=10 each). Mice in the model group were fed with HGHF diet to establish a mouse model of diabetes. Further MCMECs were purchased to construct carriers through transient transfection, and were separated into a normal group (cultured in the normal environment), a model group (not transfected), a blank carrier group (transfected with miR-NC), a miR-223-3p-mimics group, and a miR-223-3p-inhibitor group. RT-qPCR was used to detect the expression levels of miR-223-3p and NLRP3, and western blot analysis to detect the expression levels of NLRP3, apoptosis-related proteins Bax and caspase-3, and anti-apoptotic protein Bcl-2. Flow cytometry was used to observe apoptosis and TargetScan to predict the target relationship between miR-223-3p and NLRP3. Dual-luciferase reporter gene assay was used to detect the relationship between miR-223-3p and NLRP3. Compared with those in the control group, the mice in the model group had significantly lower expression of miR-223-3p. However, significantly higher mRNA and protein expression levels of NLRP3 were observed (P<0.05). After modeling, miR-223-3p overexpression downregulated the expression levels of NLRP3 mRNA, Bax and NLRP3 protein, as well as inhibited endothelial cell apoptosis (P<0.05), while the inhibition of miR-223-3p expression upregulated the expression levels and promoted apoptosis. In conclusion, miR-223-3p expression is low, however, NLRP3 is highly expressed in the heart tissue of HGHF-induced diabetic mice. miR-223-3p reduces the injury of MCMECs and inhibits endothelial cell apoptosis in mice by regulating the expression of NLRP3.

A Nested Asymmetric PCR Melting Curve Assay for One-Step Genotyping of Nondeletional α-Thalassemia Mutations

A rapid DNA-based assay is essential for clinical diagnosis and mass screening in thalassemia-prevention programs. Because of high homology and guanine-cytosine-rich and complex second structure of α-globin genes, it is rather difficult to develop a feasible and simple method for α-thalassemia genotyping. In this study, a strategy of nested asymmetric PCR melting curve analysis was designed to tackle these factors and ensure sensitivity and accuracy. Herein, a novel one-step assay for genotyping of nondeletional α-thalassemia mutations, including hemoglobin (Hb) Westmead (HBA2: c.369C>G), Hb Quong Sze (HBA2: c.377T>C), Hb Constant Spring (HBA2: c.427T>C), CD30 (HBA2: c.91-93delGAG), and CD31 (HBA2: c.95G>A) in a single closed tube, was established and evaluated. All five mutations were accurately determined with the concordance rate of 100% in a blind analysis of 255 genotype-known samples and 1250 clinical samples. In conclusion, this assay is useful for rapid and reliable genotyping of nondeletional α-thalassemia mutations in clinical practice. Especially, the strategy may have the potential to be a versatile scheme for rapid genotyping of other gene mutations because of its high throughput, sufficient stability, low cost, and simple operation.

Clinicopathological and prognostic values of ErbB receptor family amplification in primary osteosarcoma

Osteosarcoma is a malignant bone tumor with extremely high invasion, metastasis and mortality. The prognosis of patients with osteosarcoma remains poor. The ErbB receptor family was found to be overexpressed in human cancers and associated with poor prognosis. However, the role of ErbB receptor family in osteosarcoma has not been fully understood. The present study aimed to investigate the clinicopathological and prognostic significances of ErbB receptors in primary osteosarcoma. Western blot (WB), reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and fluorescence in situ hybridization (FISH) were used to detect the protein and gene expression of ErbB receptors in 60 primary osteosarcoma specimens and 30 non-neoplastic bone tissues. WB and RT-qPCR analyses showed that the protein and mRNA expression levels of EGFR, ErbB3 and ErbB4 in osteosarcoma specimens were significantly higher than those in non-neoplastic bone tissues. Seventeen (28.33%), 15 (25.00%) and 15 (25.00%) osteosarcoma specimens presented with amplification of EGFR, ErbB3 and ErbB4 gene, respectively, which were significantly higher compared with non-neoplastic bone tissues. The amplification of ErbB3 and ErbB4 in osteosarcoma was associated with advanced surgical stage. The amplification of EGFR, ErbB3, ErbB4 and the co-amplification of EGFR-ErbB3, EGFR-ErbB4, ErbB3-ErbB4 was linked with poor response to chemotherapy and distant metastasis. The amplification of EGFR, ErbB3 and ErbB4, as well as their co-amplification demonstrated independent prognostic values for reduced survival time of osteosarcoma patients and may serve as potential therapeutic targets for osteosarcoma patients in the future.

A novel 223 kb deletion in the beta-globin gene cluster was identified in a Chinese thalassemia major patient

INTRODUCTION

Although mutations in the human beta-globin gene cluster are essentially point mutations, several large deletions have been described in recent years.

METHODS

We have identified a novel 223 kb deletion in a Chinese patient by multiplex ligation-dependent probe amplification and characterized it by next-generation sequencing, Gap-PCR, and DNA sequence analysis.

RESULTS

The deletion extends from the 3'UTR of the δ globin gene (HBD) to 215 kb downstream of the HBB. Compound heterozygous with the typical β-thalassemia-CD41-42(-CTTT) mutation, the proband presented with microcytosis and hypochromic red cells, and required regulate transfusion. The patient was clinically diagnosed with thalassemia major.

CONCLUSION

Our study widens the mutation spectrum of β-thalassemia. In addition, this case may spark future studies of the regulatory regions of the beta-globin gene cluster.

Tanshinone IIA inhibits lipopolysaccharide‑induced inflammatory responses through the TLR4/TAK1/NF‑κB signaling pathway in vascular smooth muscle cells

To aim of the present study was to determine whether Tanshinone IIA (Tan IIA) inhibits lipopolysaccharide (LPS)‑induced inflammation in vascular smooth muscle cells (VSMCs) from rats and elucidate the underlying molecular mechanism. VSMCs were primarily cultured and then treated with LPS (1 µg/l) and Tan IIA (25, 50 and 100 µmol/l) for 24 h. Monocyte chemoattractant protein (MCP)‑1, interleukin (IL)‑6 and tumor necrosis factor (TNF)‑α levels were detected by ELISA and reverse transcription‑quantitative polymerase chain reaction. Nitric oxide (NO) production was measured using the Griess reaction. The expression of Toll‑like receptor 4 (TLR4), nuclear factor (NF)‑κB (p65), and inducible NO synthase (iNOS), and the phosphorylation of transforming growth factor‑β‑activated kinase 1 (TAK1) were detected by western blot analysis. Tan IIA inhibited the LPS‑induced expression of MCP‑1, IL‑6, and TNF‑α in a concentration‑dependent manner and inhibited iNOS‑mediated NO production. In addition, Tan IIA suppressed the expression of TLR4, the phosphorylation of TAK1, and the nuclear translocation of NF‑κB (p65). The anti‑TLR4 antibody and TAK1 inhibitor 5Z‑7‑oxozeaenol partially attenuated the LPS‑induced expression of proinflammatory cytokines. In conclusion, Tan IIA inhibits LPS‑induced inflammatory responses in VSMCs in vitro through the partial suppression of the TLR4/TAK1/NF‑κB signaling pathway.

[Rapid preimplantation genetic diagnosis of α-thalassemia SEA deletion with blastocyst cell whole genome amplification and short fragment Gap-PCR method]

OBJECTIVE

To develop a rapid preimplantation genetic diagnosis method for α-thalassemia SEA deletion based on blastocyst cell whole genome amplification (WGA) combined with short fragment Gap-PCR.

METHODS

Using multiple displacement amplification (MDA) WGA technique, we established a double-fluorescent PCR system of the housekeeping genes GAPDH and β-actin for WGA quality testing, and a genotyping PCR system of mutant and normal short sequences for α-thalassemia SEA deletion. The sensitivity and accuracy of this method for diagnosis of α-thalassemia SEA deletion were evaluated by detecting lymphocyte samples containing different cell numbers from carriers of SEA deletion. The applicability of this method was evaluated by testing of 12 blastocyst biopsy samples.

RESULTS

Detection of lymphocyte samples with different cell numbers using the method developed in this study revealed no ADO in 3-cell samples, and the product quantity of WGA became stable for 4-cell samples. Genotyping of the 10 blastocyst biopsy samples with successful WGA showed a genotype of --^SEA/αα in 5 samples and αα/αα in the other 5 samples, which were consistent with the verification results.

CONCLUSIONS

The method developed in this study is a complete testing process for 4-6 blastocyst biopsy cells to allow rapid, accurate, and cost-effective PGD genotyping of α-thalassemia SEA deletion using short fragment gap-PCR.

Hypoxia-inducible factor 1 mediates intermittent hypoxia-induced migration of human breast cancer MDA-MB-231 cells

Metastasis is the major cause of triple-negative breast cancer (TNBC)-associated mortality. Hypoxia promotes cancer cell migration and remote metastasis, which occur with hypoxia inducible factor 1α (HIF-1α) stabilization and vimentin upregulation. However, the evolutionary dynamics that link the changes in HIF-1α and vimentin levels under hypoxic conditions are not well understood. In the present study, the effects of intermittent hypoxia (IH), continuous hypoxia (CH) and normoxia on the migration and proliferation of human TNBC MDA-MB-231 cells were investigated. The results demonstrated that IH significantly increased the migration of MDA-MB-231 cells, and this effect was dependent on the number of cycles of hypoxia-reoxygenation. Unexpectedly, IH significantly inhibited cell proliferation, while CH only caused such an effect if hypoxia extended for ≥3 days. IH and CH induced HIF-1α protein accumulation and vimentin upregulation, with a greater effect observed in IH. Knockdown of HIF-1α with siRNA abolished IH-induced cell migration and vimentin upregulation. In summary, multiple cycles of hypoxia and reoxygenation have a more pronounced effect on the promotion of TNBC invasiveness than CH; HIF-1α activation and downstream vimentin upregulation may account for this phenotypic change.

[Rapid detection of alpha-globin gene αααanti-3.7 triplets with droplet digital PCR]

OBJECTIVE

To establish a rapid method for detection of alpha-globin gene ααα^anti-3.7 based on droplet digital PCR (ddPCR) technique.

METHODS

The differential sequence between the X1 and Y1 box of α1 gene was selected as the amplicon of the target gene with β-actin as the reference gene. The specific primers and TaqMan probes were designed, and then a quantitative method for detecting the copy number was established based on ddPCR technique. The sensitivity and accuracy of the method were evaluated by detecting 28 samples of known genotypes and 60 clinical samples.

RESULTS

The ddPCR-based method accurately identified the genotypes of all the 28 samples with known genotypes and detected 5 cases of αα/ααα^anti-3.7 from the 60 clinical samples, and the results were verified by MLPA. The sensitivity and accuracy of this method were both 100% for detecting alpha-globin gene ααα^anti-3.7.

CONCLUSION

This ddPCR-based method for detecting ααα^anti-3.7 triplet can be applied for population screening and in routine clinical molecular diagnosis with simple operation, rapid analysis and accurate results.

Simultaneous Genotyping of α-Thalassemia Deletional and Nondeletional Mutations by Real-Time PCR-Based Multicolor Melting Curve Analysis

α-Thalassemia, which is caused by defective synthesis of the hemoglobin α-globin chains, is the most commonly inherited recessive hemoglobin abnormality. Genetic detection of a defective α-globin gene is challenging because of a variety of large deletions of the α-globin gene cluster and nondeletional mutations. Separate detections of them are often required using complex and error-prone open-tube methods. We report a novel real-time PCR-based assay that can simultaneously genotype four major deletional and three common nondeletional mutations in two parallel reactions by using multicolor melting curve analysis. The turnaround time of this closed-tube assay was within 3.5 hours, the limit of detection was 5 ng of human genomic DNA per reaction, and as low as 5% mutant DNA could be detected in the mosaic samples. The assay was evaluated using 1213 precharacterized genomic DNA samples in a double-blind manner. All seven α-thalassemia mutations were accurately genotyped, yielding a 99.3% concordance with the comparison assays. The 14 discordant samples contained the HKαα allele that was undetected by the traditional methods. Considering its rapidity, ease of use, and accuracy, we concluded that our real-time PCR assay may be recommended as an alternative screening and diagnostic tool for α-thalassemia.

Postnatal and non-invasive prenatal detection of β-thalassemia mutations based on Taqman genotyping assays

The β-thalassemias are genetic disorder caused by more than 200 mutations in the β-globin gene, resulting in a total (β⁰) or partial (β⁺) deficit of the globin chain synthesis. The most frequent Mediterranean mutations for β-thalassemia are: β⁰39, β⁺IVSI-110, β⁺IVSI-6 and β⁰IVSI-1. Several molecular techniques for the detection of point mutations have been developed based on the amplification of the DNA target by polymerase chain reaction (PCR), but they could be labor-intensive and technically demanding. On the contrary, TaqMan^® genotyping assays are a simple, sensitive and versatile method suitable for the single nucleotide polymorphism (SNP) genotyping affecting the human β-globin gene. Four TaqMan^® genotyping assays for the most common β-thalassemia mutations present in the Mediterranean area were designed and validated for the genotype characterization of genomic DNA extracted from 94 subjects comprising 25 healthy donors, 33 healthy carriers and 36 β-thalassemia patients. In addition, 15 specimens at late gestation (21–39 gestational weeks) and 11 at early gestation (5–18 gestational weeks) were collected from pregnant women, and circulating cell-free fetal DNAs were extracted and analyzed with these four genotyping assays. We developed four simple, inexpensive and versatile genotyping assays for the postnatal and prenatal identification of the thalassemia mutations β⁰39, β⁺IVSI-110, β⁺IVSI-6, β⁰IVSI-1. These genotyping assays are able to detect paternally inherited point mutations in the fetus and could be efficiently employed for non-invasive prenatal diagnosis of β-globin gene mutations, starting from the 9^th gestational week.

A novel pathway in NSCLC cells: miR‑191, targeting NFIA, is induced by chronic hypoxia, and promotes cell proliferation and migration

MicroRNAs (miRs) have emerged as being important in cancer biology. miR‑191 is a conserved miRNA, which has been investigated in detail and is reported to be induced by hypoxia-inducible factor (HIF)‑1α and has an contributory action in the progression of breast, hepatic and pancreatic cancer. However, the effects of miR‑191 in the progression of lung cancer are a subject of debate. In the present study, it was found that the expression of miR-191 was significantly upregulated in non‑small cell lung cancer (NSCLC) cells in patients in vivo. However, the levels of miR‑191 remained unchanged in SK‑MES‑1, A549 and NCI‑H460 NSCLC cell lines, compared with the level in the normal HBE lung cell line, however, the levels were markedly upregulated in these NSCLC cell lines under conditions of chronic hypoxia. Subsequently, an miR‑191 mimic was transfected into the NSCLC cell lines to examine its effect on the progression of the NSCLC cells in vitro. The data obtained using MTT and Cell counting kit‑8 assays revealed that miR‑191 had no effect on the proliferation of the cells under normal condition, however, their proliferation was promoted under mild hypoxic conditions. In addition, the results of a Transwell migration assay showed that miR‑191 had a promoting effect on NSCLC cell migration under the conditions of chronic hypoxia. Furthermore, the TargetScan bioinformatics server and 3'-untranslated region luciferase reporter assay indicated that the transcription factor, nuclear factor 1α (NFIA) was a target of miR‑191. Subsequent western blot analysis showed that, in chronic‑hypoxia, the protein levels of NFIA and the tumor suppressor, CCAAT-enhancer-binding protein α, were sharply reduced in A549 cells. In conclusion, miR‑191 was induced by chronic hypoxia and promoted the proliferation and migration of NSCLC cells under chronic hypoxic conditions. This promotion may be associated with its targeting of NFIA. The present findings may provide a potential molecular target for the therapeutic treatment of NSCLC.

Elevated RNA expression of long non‑coding HOTAIR promotes cell proliferation and predicts a poor prognosis in patients with diffuse large B cell lymphoma

Diffuse large B cell lymphoma (DLBCL) is one of the most common types of malignancy worldwide. The lack of clear symptoms and early detection make it difficult to diagnose at an early stage, leading to poor prognosis of the patients. Long non-coding RNAs (lncRNAs) have come into focus for their important regulatory roles in fundamental biological processes, particularly in cancer initiation, development and progression. The aim of the present study was to investigate the expression of lncRNA Hox transcript antisense intergenic RNA (HOTAIR) in a cohort of patients with DLBCL to assess its clinical value and biological function in DLBCL. The reverse transcription-polymerase chain reaction was used to detect HOTAIR expression levels and cells were transfected with small interfering RNA to compare cell proliferation, cell cycle progression and apoptosis. Western blotting was also conducted to detect possible signaling pathways. It was first found that the expression levels of HOTAIR were upregulated in DLBCL tumor tissues and cell lines, compared with normal tissues and cells. In addition, HOTAIR was significantly correlated with tumor size, clinical stage, B symptoms and International Prognostic Index scores; and higher expression levels of HOTAIR were correlated with improved prognosis. Univariate and multivariate analyses verified that HOTAIR was a key independent predictive factor for DLBCL prognosis. Furthermore, it was revealed that the knockdown of the expression of HOTAIR led to growth inhibition, cell cycle arrest and apoptosis in vitro, possibly through the phosphoinositide 3-kinase/AKT/nuclear factor-κB pathway. These results suggested that HOTAIR may be regarded as a novel indicator of poor prognosis, and may serve as a potential target for gene therapy in the treatment of DLBCL.

Rapid diagnosis of common deletional α-thalassemia in the Chinese population by qPCR based on identical primer homologous fragments

OBJECTIVE

In China, -(SEA), -α(3.7) and -α(4.2) are common deletional α-thalassemia alleles. Gap-PCR is the currently used detection method for these alleles, whose disadvantages include time-consuming procedure and increased potential for PCR product contamination. Therefore, this detection method needs to be improved. Based on identical-primer homologous fragments, a qPCR system was developed for deletional α-thalassemia genotyping, which was composed of a group of quantitatively-related primers and their corresponding probes plus two groups of qualitatively-related primers and their corresponding probes. In order to verify the accuracy of the qPCR system, known genotype samples and random samples are employed.

RESULT

The standard curve result demonstrated that designed primers and probes all yielded good amplification efficiency. In the tests of known genotype samples and random samples, sample detection results were consistent with verification results.

CONCLUSIONS

In detecting αα, -(SEA), -α(3.7) and -α(4.2) alleles, deletional α-thalassemia alleles are accurately detected by this method. In addition, this method is provided with a wider detection range, greater speed and reduced PCR product contamination risk when compared with current common gap-PCR detection reagents.

Development and validation of a high throughput, closed tube method for the determination of haemoglobin alpha gene (HBA1 and HBA2) numbers by gene ratio assay copy enumeration-PCR (GRACE-PCR)

BACKGROUND

Deletions of the α-globin genes are the most common genetic abnormalities in the world. Currently multiplex Gap-PCRs are frequently used to identify specific sets of common deletions. However, these assays require significant post-amplification hands on time and cannot be used to identify novel or unexpected deletions. The aim of the current study was to develop a rapid screening test for the detection of all deletions of the α-globin genes that can be integrated into a high volume clinical laboratory workflow.

METHODS

A gene ratio assay copy enumeration (GRACE) PCR method was developed by simultaneous amplification of targets in the α-globin genes (HBA1 and HBA2) and the chloride channel voltage sensitive 7 (CLCN7) reference gene. A novel application of High Resolution Melting (HRM) analysis then allowed rapid determination of α-globin gene copy numbers. The assay was validated using 105 samples with previously determined and 62 samples with unknown α-globin genotypes.

RESULTS

The GRACE-PCR assay detected abnormal α-globin gene copy numbers in 108 of the 167 samples evaluated. The results were consistent with those from a commercial reverse hybridization assay and no allele drop out was observed.

CONCLUSIONS

We have successfully developed and validated a GRACE-PCR screening test for the detection of deletions and duplications of the α-globin genes. The assay is based on copy number determination and has the ability to detect both known and novel deletions of the α-globin genes. It is a closed tube technique; consequently the risk of amplicon contamination is negligible. Amplification, detection and analysis can be completed within one hour, making it faster, cheaper and simpler than other existing tests and thus well suited as a rapid first step in a clinical laboratory workflow.