Shangyi Fu

Thymoquinone, as an anticancer molecule: from basic research to clinical investigation

Thymoquinone is an anticancer phytochemical commonly found in black cumin. In this review, we discuss the potential of thymoquinone as anticancer molecule, its mechanism of action and future usage in clinical applications. Thymoquinone exhibits anticancer activity via numerous mechanisms of action, specifically by showing selective antioxidant and oxidant activity, interfering with DNA structure, affecting carcinogenic signaling molecules/pathways and immunomodulation. In vitro activity of thymoquinone has been further implicated in animal models of cancer; however, no clinical application has been proven yet. This is the optimum time to focus on clinical trials for developing thymoquinone as a future drug in cancer therapeutics.Thymoquinone is an anticancer phytochemical commonly found in black cumin. In this review, we discuss the potential of thymoquinone as anticancer molecule, its mechanism of action and future usage in clinical applications. Thymoquinone exhibits anticancer activity via numerous mechanisms of action, specifically by showing selective antioxidant and oxidant activity, interfering with DNA structure, affecting carcinogenic signaling molecules/pathways and immunomodulation. In vitro activity of thymoquinone has been further implicated in animal models of cancer; however, no clinical application has been proven yet. This is the optimum time to focus on clinical trials for developing thymoquinone as a future drug in cancer therapeutics.

MicroRNA-34a targets epithelial to mesenchymal transition-inducing transcription factors (EMT-TFs) and inhibits breast cancer cell migration and invasion

MicroRNA-34a (miR-34a) plays an essential role against tumorigenesis and progression of cancer metastasis. Here, we analyzed the expression, targets and functional effects of miR-34a on epithelial to mesenchymal transition-inducing transcription factors (EMT-TFs), such as TWIST1, SLUG and ZEB1/2, and an EMT-inducing protein NOTCH1 in breast cancer (BC) cell migration and invasion and its correlation with tumorigenesis and clinical outcomes. Expression of miR-34a is downregulated in human metastatic breast cancers (MBC) compared to normal breast tissues and is negatively correlated with clinicopathological features of MBC patients. Ectopic expression of miR-34a in MBC cell-line BT-549 significantly inhibits cell migration and invasion, but exhibits no clear effect on BC cell growth. We found that miR-34a is able to inactivate EMT signaling pathway with mediatory of NOTCH1, TWIST1, and ZEB1 upon 3′-UTR activity in MBC cell lines, but has no inhibitory effects on SLUG and ZEB2. Furthermore, we investigated the synergistic effects of Thymoquinone (TQ) and miR-34a together on the expression of EMT-associated proteins. Results showed that co-delivery of miR-34a and TQ is able to inactivate EMT signaling pathway by directly targeting TWIST1 and ZEB1 in BT-549 cell line, indicating that they might be a promising therapeutic combination against breast cancer metastasis. Epigenetic inactivation of the EMT-TFs/miR-34a pathway can potentially alter the equilibrium of these regulations, facilitating EMT and metastasis in BC. Altogether, our findings suggest that miR-34a alone could serve as a potential therapeutic agent for MBC, and together with TQ, their therapeutic potential is synergistically enhanced.

Development of diagnostic SCAR markers for genomic DNA amplifications in breast carcinoma by DNA cloning of high-GC RAMP-PCR fragments

Cancer is genetically heterogeneous regarding to molecular genetic characteristics and pathogenic pathways. A wide spectrum of biomarkers, including DNA markers, is used in determining genomic instability, molecular subtype determination and disease prognosis, and estimating sensitivity to different drugs in clinical practice. In a previous study, we developed highly effective DNA markers using improved random amplified polymorphic DNA (RAPD) with high-GC primers, which is a valuable approach for the genetic authentication of medicinal plants. In this study, we applied this effective DNA marker technique to generate genetic fingerprints that detect genomic alterations in human breast cancer tissues and then developed sequence-characterized amplified region (SCAR) markers. Three SCAR markers (BC10-1, BC13-4 and BC31-2) had high levels of genomic DNA amplification in breast cancer. The PHKG2 and RNF40 genes are either overlapping or close to the sequences of SCAR marker BC13-4, while SCAR marker BC10-1 is in the intron and overlap the DPEP1 gene, suggesting that alterations in the expression of these genes could contribute to cancer progression. Screening of breast cancer cell lines showed that the mRNA expression levels for the PHKG2 and DPEP1 were lower in non-tumorigenic mammary epithelial cell MCF10A, but elevated in other cell lines. The DPEP1 mRNA level in invasive ductal carcinoma specimens was significantly higher than that of the adjacent normal tissues in women. Taken together, high-GC RAMP-PCR provides greater efficacy in measuring genomic DNA amplifications, deletion or copy number variations. Furthermore, SCAR markers BC10-1 and BC13-4 might be useful diagnostic markers for breast cancer carcinomas.

The diagnostic role of microRNA-34a in breast cancer: a systematic review and meta-analysis

Background MicroRNA-34a (miR-34a) is a master regulator of tumor suppression in breast cancer (BC). This systematic review aims to analyze the diagnostic accuracy of miR-34a in the detection of BC as a biomarker. Results A total of 1858 BC cases and 494 controls from thirteen eligible studies reported in 9 publications were included. The overall pooled sensitivity, specificity, negative likelihood ratio (NLR), positive likelihood ratio (PLR), and diagnostic odds ratio (DOR) were 85.50% (95% CI: 83.80-87.00%), 70.00% (95% CI: 65.80–74.10%), 0.29 (95% CI: 0.19–0.43), 2.58 (95% CI: 1.91–3.43), and 9.39 (95% CI: 5.47–16.12), respectively. Similarly, the overall area under the curve (AUC) of the summary receiver operating characteristic (SROC) was 0.80, indicating the high conservation of miR-34a as a biomarker. Furthermore, subgroup analysis suggested that the use of miR-34a as a biomarker is more accurate in tissue-based sample of invasive BC. We also indicated that miR-34a is a capable biomarker in diagnosing BC in people of Caucasian descent. Materials and Methods A systematic search was conducted for eligible publications that address miR-34a expression level in BC cases and noncancerous controls. Diagnostic capacity of miR-34a for BC was assessed using pooled sensitivity and specificity, DOR, and AUC of SROC. PLR and NLR were verified to estimate the miR-34a diagnostic accuracy in clinical level. The quality of the included studies was assessed by QUADAS-2. Conclusions These findings suggest miR-34a is a promising non-invasive biomarker in diagnosing BC. Well-designed cohort studies should be implemented to warrant the diagnostic value of miR-34a in clinical purposes.

Molecular genetics characterization and homology modeling of the CHM gene mutation: A study on its association with choroideremia

Choroideremia (CHM) is a rare form of X-linked chorioretinal dystrophy that is caused by mutations in the CHM gene. Mutations in the Rab escort protein-1 (REP-1), an ubiquitously encoded protein of the CHM gene, lead to prenylation and vesicle trafficking deficiency in the protein, resulting in the progressive degeneration of choriocapillaris, retinal pigment epithelium (RPE), and photoreceptors. Despite previous studies concerning this disease, no effective diagnostic tests or established therapeutic interventions currently exist for CHM. In this paper, we reviewed ‎the pathogenic ‎effects of synonymous hotspot mutation in the CHM gene and the genotypic-phenotypic associations in families with CHM. In addition, we employed a combination of molecular dynamics simulations and principal component analysis to gain insight into the underlying molecular basis of these deleterious and disease-causing hotspot mutation ‎analogs. These computer predictions provide strong evidence that the C > T nonsynonymous hotspot mutations of CHM spectrum contribute to overall RPE retinopathy. These findings increase our understanding of the CHM ‎pathogenesis, which may potentially define a new approach in developing novel symbiotic strategies for genetic diagnosis and specific treatment of inherited retinal diseases.

Identification of a novel RPGRIP1 mutation in an Iranian family with leber congenital amaurosis by exome sequencing

Leber congenital amaurosis (LCA) is a heterogeneous, early‐onset inherited retinal dystrophy, which is associated with severe visual impairment. We aimed to determine the disease‐causing variants in Iranian LCA and evaluate the clinical implications. Clinically, a possible LCA disease was found through diagnostic imaging, such as fundus photography, autofluorescence and optical coherence tomography. All affected patients showed typical eye symptoms associated with LCA including narrow arterioles, blindness, pigmentary changes and nystagmus. Target exome sequencing was performed to analyse the proband DNA. A homozygous novel c. 2889delT (p.P963 fs) mutation in the RPGRIP1 gene was identified, which was likely the deleterious and pathogenic mutation in the proband. Structurally, this mutation lost a retinitis pigmentosa GTPase regulator (RPGR)‐interacting domain at the C‐terminus which most likely impaired stability in the RPGRIP1 with the distribution of polarised proteins in the cilium connecting process. Sanger sequencing showed complete co‐segregation in this pedigree. This study provides compelling evidence that the c. 2889delT (p.P963 fs) mutation in the RPGRIP1 gene works as a pathogenic mutation that contributes to the progression of LCA.

Genetic Identification and Molecular Modeling Characterization Reveal a Novel PROM1 Mutation in Stargardt4-like Macular Dystrophy

Stargardt disease-4 (STGD4) is an autosomal dominant complex, genetically heterogeneous macular degeneration/dystrophy (MD) disorder. In this paper, we used targeted next generation sequencing and multiple molecular dynamics analyses to identify and characterize a disease-causing genetic variant in four generations of a Chinese family with STGD4-like MD. We found a novel heterozygous missense mutation, c.734T>C (p.L245P) in the PROM1 gene. Structurally, this mutation most likely impairs PROM1 protein stability, flexibility, and amino acid interaction network after changing the amino acid residue Leucine into Proline in the basic helix-loop-helix leucine zipper domain. Molecular dynamic simulation and principal component analysis provide compelling evidence that this PROM1 mutation contributes to disease causativeness or susceptibility variants in patients with STGD4-like MD. Thus, this finding defines new approaches in genetic characterization, accurate diagnosis, and prevention of STGD4-like MD.

A novel homozygous variant of GPR98 causes usher syndrome type IIC in a consanguineous Chinese family by next generation sequencing

BackgroundUsher syndrome (USH) is a common heterogeneous retinopathy and a hearing loss (HL) syndrome. However, the gene causing Usher syndrome type IIC (USH2C) in a consanguineous Chinese pedigree is unknown.MethodsWe performed targeted next-generation sequencing analysis and Sanger sequencing to explore the GPR98 mutations in a USH2C pedigree that included a 32-year-old male patient from a consanguineous marriage family. Western blot verified the nonsense mutation.ResultsTo identify disease-causing gene variants in a consanguineous Chinese pedigree with USH2C, DNA from proband was analyzed using targeted next generation sequencing (NGS). The patient was clinically documented as a possible USH2 by a comprehensive auditory and ophthalmology evaluation. We succeeded in identifying the deleterious, novel, and homologous variant, c.6912dupG (p.Leu2305Valfs*4), in the GPR98 gene (NM_032119.3) that contributes to the progression of USH2C. Variant detected by targeted NGS was then confirmed and co-segregation was conducted by direct Sanger sequencing. Western blot verified losing almost two-thirds of its amino acid residues, including partial Calx-beta, whole EPTP and 7TM-GPCRs at the C-terminus of GPR98. Furthermore, our results highlighted that this p.Leu2305Valfs*4 variant is most likely pathogenic due to a large deletion at the seven-transmembrane G protein-coupled receptors (7TM-GPCRs) domain in GPR98 protein, leading to significantly decreased functionality and complex stability.ConclusionsThese findings characterized the novel disease causativeness variant in GPR98 and broaden mutation spectrums, which could predict the pathogenic progression of patient with USH2C, guide diagnosis and treatment of this disease; and provide genetic counseling and family planning for consanguineous marriage pedigree in developing countries, including China.

A novel, homozygous nonsense variant of the CDHR1 gene in a Chinese family causes autosomal recessive retinal dystrophy by NGS-based genetic diagnosis

Retinal dystrophy is an inherited, heterogeneous, chronic and progressive disorder of visual functions. The mutations of patients with autosomal recessive retinal retinopathy cone‐and‐rod dysfunction and macular dystrophy have not been well described in the Chinese population. In this study, a three‐generation Chinese retinal dystrophy family was recruited. Ophthalmic examinations were performed. Targeted next generation sequencing (TGS) was used to identify causative genes, and Sanger sequencing was conducted to verify candidate mutations and co‐segregation. Reverse transcription (RT)‐PCR was applied to investigate the spatial and temporal expression patterns of cdhr1 gene in mouse. A novel, homozygous, deleterious and nonsense variant (c.T1641A; p.Y547*) in the CDHR1 gene was identified in the family with autosomal recessive retinal dystrophy, which was co‐segregated with the clinical phenotypes in this family. RT‐PCR analysis revealed that cdhr1 is ubiquitously expressed in eye, particularly very high expression in retina; high expression in lens, sclera, and cornea; and high expression in brain. In conclusion, our study is the first to indicate that the novel homozygous variant c.T1641A (p.Y547*) in the CHDR1 gene might be the disease‐causing mutation for retinal dystrophy in our patient, extending its mutation spectrums. These findings further the understanding of the molecular pathogenesis of this disease and provide new insights for diagnosis as well as new implications for genetic counselling.

In silico data analyses of the hotspot mutations of CHM gene in choroideremia disease

This data article provides compelling computational analysis of the hotspot CHM gene mutations that contribute to the progressive causativeness and susceptibility of Choroideremia in patients. We performed structural and molecular dynamics (MD) simulation analysis on abnormal states of the CHM protein caused by deleterious and disease-causing hotspot mutant forms of CHM: S89C, E177K, and V529H. Within 40 ns, MD simulation time composed of the E177K mutant shows conformational alteration especially in several parts of the variant. Mathematically, we applied eigenvector analysis to determine the modes of flexibility and atomic positional fluctuations that contribute significantly to the overall motion of the CHM protein in terms of structural alteration, free energy landscapes (FEL), entropy, enthalpy, and principal component analysis (PCA). The data described here are related to the article entitled “Molecular Genetics Characterization and Homology Modeling of the CHM Gene Mutation: A study on Its Association with Choroideremia” (Imani et al., 2018) [1].