An integrated cofactor and co-substrate recycling pathway for the biosynthesis of 1,5-pentanediol.

BACKGROUND: 1,5-pentanediol (1,5-PDO) is a linear diol with an odd number of methylene groups, which is an important raw material for polyurethane production. In recent years, the chemical methods have been predominantly employed for synthesizing 1,5-PDO. However, with the increasing emphasis on environmentally friendly production, it has been a growing interest in the biosynthesis of 1,5-PDO. Due to the limited availability of only three reported feasible biosynthesis pathways, we developed a new biosynthetic pathway to form a cell factory in Escherichia coli to produce 1,5-PDO. RESULTS: In this study, we reported an artificial pathway for the synthesis of 1,5-PDO from lysine with an integrated cofactor and co-substrate recycling and also evaluated its feasibility in E.coli. To get through the pathway, we first screened aminotransferases originated from different organisms to identify the enzyme that could successfully transfer two amines from cadaverine, and thus GabT from E. coli was characterized. It was then cascaded with lysine decarboxylase and alcohol dehydrogenase from E. coli to achieve the whole-cell production of 1,5-PDO from lysine. To improve the whole-cell activity for 1,5-PDO production, we employed a protein scaffold of EutM for GabT assembly and glutamate dehydrogenase was also validated for the recycling of NADPH and α-ketoglutaric acid (α-KG). After optimizing the cultivation and bioconversion conditions, the titer of 1,5-PDO reached 4.03 mM. CONCLUSION: We established a novel pathway for 1,5-PDO production through two consecutive transamination reaction from cadaverine, and also integrated cofactor and co-substrate recycling system, which provided an alternative option for the biosynthesis of 1,5-PDO.

WTAP gene variants and susceptibility to ovarian endometriosis in a Chinese population.

Background: Endometriosis is a common chronic gynecologic disorder with a significant negative impact on women's health. Wilms tumor 1-associated protein (WTAP) is a vital component of the RNA methyltransferase complex for N6-methyladenosine modification and plays a critical role in various human diseases. However, whether single nucleotide polymorphisms (SNPs) of the WTAP gene predispose to endometriosis risk remains to be investigated. Methods: We genotyped three WTAP polymorphisms in 473 ovarian endometriosis patients and 459 control participants using the Agena Bioscience MassArray iPLEX platform. The logistic regression models were utilized to assess the associations between WTAP SNPs and the risk of ovarian endometriosis. Results: In the single-locus analyses, we found that the rs1853259 G variant genotypes significantly increased, while the rs7766006 T variant genotypes significantly decreased the association with ovarian endometriosis risk. Combined analysis indicated that individuals with two unfavorable genotypes showed significantly higher ovarian endometriosis risk (adjusted OR = 1.71 [1.23-2.37], p = 0.001) than those with zero risk genotypes. In the stratified analysis, the risk effect of the rs1853259 AG/GG and rs7766006 GG genotypes was evident in subgroups of age ≤30, gravidity≤1, parity≤1, rASRM stage I, and the rs7766006 GG genotype was associated with worse risk (adjusted OR = 1.64 [1.08-2.48], p = 0.021) in the patients with rASRM stage II + III + IV. The haplotype analysis indicated that individuals with GGG haplotypes had a higher risk of ovarian endometriosis than wild-type AGG haplotype carriers. Moreover, false positive report probability and Bayesian false discovery probability analysis validated the reliability of the significant results. The quantitative expression trait loci analysis revealed that rs1853259 and rs7766006 were correlated with the expression levels of WTAP. Conclusion: Our findings demonstrated that WTAP polymorphisms were associated with susceptibility to ovarian endometriosis among Chinese women.

Synthesis of NMN by cascade catalysis of intracellular multiple enzymes.

ß-Nicotinamide mononucleotide is a biologically active nucleotide compound, and its excellent anti-aging activity is widely used in medicine and has multiple functions, making NMN have broad application prospects in the fields of nutrition, health food, and even medicine. Herein, based on the supply of the co-substrate PRPP, we designed and constructed three in vivo NMN synthesis pathways using glucose, xylose, and arabinose as raw materials and Escherichia coli as the host. The best in vivo pathway through whole-cell catalysis was identified. Then, we optimized the cell culture and catalytic conditions of the optimal path to determine the optimal conditions and ultimately obtained an NMN titer of 1.8 mM.

Variant rs8400 enhances ALKBH5 expression through disrupting miR-186 binding and promotes neuroblastoma progression.

Objective: AlkB homolog 5 (ALKBH5) has been proven to be closely related to tumors. However, the role and molecular mechanism of ALKBH5 in neuroblastomas have rarely been reported. Methods: The potential functional single-nucleotide polymorphisms (SNPs) in ALKBH5 were identified by National Center for Biotechnology Information (NCBI) dbSNP screening and SNPinfo software. TaqMan probes were used for genotyping. A multiple logistic regression model was used to evaluate the effects of different SNP loci on the risk of neuroblastoma. The expression of ALKBH5 in neuroblastoma was evaluated by Western blotting and immunohistochemistry (IHC). Cell counting kit-8 (CCK-8), plate colony formation and 5-ethynyl-2'-deoxyuridine (EdU) incorporation assays were used to evaluate cell proliferation. Wound healing and Transwell assays were used to compare cell migration and invasion. Thermodynamic modelling was performed to predict the ability of miRNAs to bind to ALKBH5 with the rs8400 G/A polymorphism. RNA sequencing, N6-methyladenosine (m6A) sequencing, m6A methylated RNA immunoprecipitation (MeRIP) and a luciferase assay were used to identify the targeting effect of ALKBH5 on SPP1. Results: ALKBH5 was highly expressed in neuroblastoma. Knocking down ALKBH5 inhibited the proliferation, migration and invasion of cancer cells. miR-186-3p negatively regulates the expression of ALKBH5, and this ability is affected by the rs8400 polymorphism. When the G nucleotide was mutated to A, the ability of miR-186-3p to bind to the 3'-UTR of ALKBH5 decreased, resulting in upregulation of ALKBH5. SPP1 is the downstream target gene of the ALKBH5 oncogene. Knocking down SPP1 partially restored the inhibitory effect of ALKBH5 downregulation on neuroblastoma. Downregulation of ALKBH5 can improve the therapeutic efficacy of carboplatin and etoposide in neuroblastoma. Conclusions: We first found that the rs8400 G>A polymorphism in the m6A demethylase-encoding gene ALKBH5 increases neuroblastoma susceptibility and determines the related mechanisms. The aberrant regulation of ALKBH5 by miR-186-3p caused by this genetic variation in ALKBH5 promotes the occurrence and development of neuroblastoma through the ALKBH5-SPP1 axis.

Genetic variations in nucleotide excision repair pathway genes and hepatoblastoma susceptibility.

The etiology of hepatoblastoma is largely unknown due to the rarity of this disease. Nucleotide excision repair (NER), a versatile system in repairing DNA damage, is highly implicated in carcinogenesis. However, it remains unclear whether single nucleotide polymorphisms (SNPs) of genes in the NER pathway are related to hepatoblastoma risk. A total of 313 Chinese children diagnosed with hepatoblastoma and 1446 controls were recruited from seven hospitals across China. TaqMan assay was adopted to genotype 19 SNPs in NER pathway genes including ERCC1, XPA, XPC, XPD, XPF and XPG. Of them, only two SNPs in XPC gene predisposed to hepatoblastoma risk. The XPC rs2607775 polymorphism significantly contributed to hepatoblastoma risk (dominant model: adjusted OR = 1.44, 95% CI = 1.01-2.05, P = .046). However, XPC rs1870134 conferred a significantly decreased risk of hepatoblastoma in recessive model (adjusted OR = 0.50, 95% CI = 0.26-0.98, P = .042). Stratified analysis revealed that rs2607775 CG/GG genotype, rs1870134 CC genotype and four to five risk genotypes were associated with the risk of hepatoblastoma under certain subgroups. The significant relationships were confirmed by haplotype analyses and false-positive report probability analyses. In addition, expression quantitative trait locus analysis suggested that rs2607775 G increased expression of XPC mRNA. Collectively, our discover a promising candidate XPC gene as a biomarker for the risk of hepatoblastoma.

Common genetic variants in pre-microRNAs are associated with cervical cancer susceptibility in southern Chinese women.

Cervical cancer is a commonly diagnosed cancer among females. Polymorphisms in pre-microRNAs have been demonstrated to play critical roles in cancer. However, the roles of pre-microRNA polymorphisms in the aetiology of cervical cancer have not been well documented. We genotyped eight pre-microRNA polymorphisms in 290 cervical cancer patients and 445 cancer-free female controls using quantitative polymerase chain reaction with TaqMan probes. To estimate the association between pre-microRNA polymorphisms and the risk of cervical cancer, an unconditional logistic regression model was used to calculate the odds ratio (OR) and 95% confidence interval (CI), adjusting for age, menopause, delivery, and abortion. We found that the pre-miR-137 rs1625579 T > G polymorphism was associated with a significant decrease in cervical cancer risk (TG/GG versus TT: adjusted OR (AOR) = 0.47, 95% CI = 0.27-0.81; TG versus TT: AOR = 0.56, 95% CI = 0.34-0.91). We also observed a significant association between the pre-miR-27a rs895819 T > C polymorphism and decreased cervical cancer risk (TC/CC versus TT: AOR = 0.65, 95% CI = 0.44-0.96). Stratified analysis further demonstrated that the pre-miR-137 rs1625579 T > C and pre-miR-27a rs895819 T > C polymorphisms significantly reduced the risk of cervical cancer susceptibility in patients younger than 49 years, those who experienced fewer abortions, and clinical stage I patients. Moreover, the pre-miR-137 rs1625579 T > G polymorphism showed protective effects in premenopausal women, squamous cell carcinoma patients, and patients with unclassified types of pathologies; the pre-miR-27a rs895819 T > C polymorphism was also associated with a decreased risk in patients older than 49 years, menopausal women, and women who had experienced vaginal pregnancies. The pre-miR-137 rs1625579 T > G and pre-miR-27a rs895819 T > C polymorphisms may provide protective effects against susceptibility to cervical cancer risk.

Association of polymorphisms in MALAT1 with the risk of endometriosis in Southern Chinese women.

Endometriosis is a common estrogen-dependent inflammatory disease characterized by the presence of endometrial-like tissue outside the uterine cavity, which causes infertility and pelvic pain. Polymorphisms in MALAT1 have been demonstrated to play crucial roles in many diseases. However, the roles of MALAT1 polymorphisms in the etiology of endometriosis have not been well documented. We genotyped three MALAT1 polymorphisms in 555 endometriosis patients and 535 female control participants using quantitative polymerase chain reaction with TaqMan probes. To estimate the associations between MALAT1 polymorphisms and endometriosis risk, an unconditional logistic regression model was conducted to calculate an odds ratio (OR) and the 95% confidence interval (CI), adjusting for age, abortion history, number of deliveries, Body Mass Index (BMI), and The International Federation of Gynecology and Obstetrics (FIGO) stage. We found that the MALAT1 rs591291 C > T polymorphism significantly enhanced endometriosis risk (heterogeneous: adjusted OR = 1.36, 95% CI = 1.00-1.85, P = 0.050; homogenous: adjusted OR = 1.55, 95% CI = 1.03-2.33, P = 0.037; dominant: adjusted OR = 1.41, 95% CI = 1.05-1.88, P = 0.021). In stratification analyses, these associations were more predominant in the patients younger than 35 years old, with a relatively high number of deliveries and with a BMI between 25 and 29.9. Compared with wild-type CCG haplotype carriers, individuals with TCC haplotypes had a higher risk of developing endometriosis. The MALAT1 rs591291 C > T polymorphism was associated with a significant increase in endometriosis risk.

Association of polymorphisms in MALAT1 with the risk of endometrial cancer in Southern Chinese women.

BACKGROUND: Endometrial cancer is the most common gynecologic malignancy worldwide. Polymorphisms in MALAT1 have been demonstrated to play critical roles in cancer. However, the roles of MALAT1 polymorphisms in the etiology of endometrial cancer have not been well documented. METHODS: We genotyped three MALAT1 polymorphisms in 249 endometrial cancer cases and 446 cancer-free female controls using quantitative polymerase chain reaction with TaqMan probes. To estimate the association between MALAT1 polymorphisms (rs591291 C>T, rs664589 C>G, and rs4102217 G>C) and the risk of endometrial cancer, an unconditional logistic regression model was conducted to calculate the odds ratio (OR) and the 95% confidence interval (CI), adjusting for surgery history, menopause, number of deliveries, BMI, and FIGO stage. RESULTS: We found that the MALAT1 rs664589 C>G polymorphism was significantly associated with endometrial cancer risk (heterogeneous: adjusted OR = 0.57, 95% CI = 0.34-0.93, P = .026; homogenous: adjusted OR = 3.74, 95% CI = 1.12-12.45, P = .032; and recessive: adjusted OR = 4.06, 95% CI = 1.22-13.48, P = .022). Stratified analysis further demonstrated that the MALAT1 rs664589 C>G polymorphism significantly increased the risk of endometrial cancer susceptibility in patients with no history of surgery, more deliveries, BMI between 25 and 29.9, and FIGO stages II-III. Compared with the wild-type GCG haplotype carriers, individuals with CGG haplotypes had a higher risk of developing endometrial cancer. CONCLUSION: The MALAT1 rs664589 C>G polymorphism was associated with a significant increase in endometrial cancer risk.

Expression and clinical significance of miRNA-145 and miRNA-218 in laryngeal cancer.

Expression of miRNA-145 and miRNA-218 in serum of patients with laryngeal cancer and the relationship between them and the clinicopathological parameters and prognosis were investigated. The clinical medical records of 132 patients with laryngeal cancer, who were admitted to Guangdong Second Provincial General Hospital from February 2009 to March 2014, were retrospectively analyzed and comprised the study group. The data of physical examinations of 56 healthy volunteers who took physical examinations in the same hospital comprised the control group. RT-qPCR was used to detect the expression levels of miRNA-145 and miRNA-218 in serum of the patients in the two groups. According to the relative expression levels of miRNA-145 and miRNA-218 in serum of the patients in the study group on the day when they left hospital, the study group was divided into the high expression group (n=73 patients) and the low expression group (n=59 patients). The patients received a 48-month follow-up visit and their survival condition was recorded and the Kaplan-Meier was used to carry out the survival analysis. The expression levels of miRNA-145 and miRNA-218 in serum of the patients in the study group were lower than those in the control group (P<0.05). The median survival time of the patients in the high expression group was 30 months while the median survival time of the patients in the low expression group was 26 months. The expression levels of miRNA-145 and miRNA-218 in serum of patients with laryngeal cancer decreased, the higher the expression levels of miRNA-145 and miRNA-218 in serum of patients with laryngeal cancer were, the better the prognosis was. miRNA-145 and miRNA-218 were used as indicators of assessing the prognosis of patients with laryngeal cancer.

Regulatory Role of RNA N6-Methyladenosine Modification in Bone Biology and Osteoporosis.

Osteoporosis is a metabolic skeletal disorder in which bone mass is depleted and bone structure is destroyed to the degree that bone becomes fragile and prone to fractures. Emerging evidence suggests that N6-methyladenosine (m6A) modification, a novel epitranscriptomic marker, has a significant role in bone development and metabolism. M6A modification not only participates in bone development, but also plays important roles as writers and erasers in the osteoporosis. M6A methyltransferase METTL3 and demethyltransferase FTO involves in the delicate process between adipogenesis differentiation and osteogenic differentiation, which is important for the pathological development of osteoporosis. Conditional knockdown of the METTL3 in bone marrow stem cells (BMSCs) could suppress PI3K-Akt signaling, limit the expression of bone formation-related genes (such as Runx2 and Osterix), restrain the expression of vascular endothelial growth factor (VEGF) and down-regulate the decreased translation efficiency of parathyroid hormone receptor-1 mRNA. Meanwhile, knockdown of the METTL3 significantly promoted the adipogenesis process and janus kinase 1 (JAK1) protein expression via an m6A-dependent way. Specifically, there was a negative correlation between METTL3 expression and porcine BMSCs adipogenesis. The evidence above suggested that the relationship between METTL3 expression and adipogenesis was inverse, and osteogenesis was positive, respectively. Similarly, FTO regulated for BMSCs fate determination during osteoporosis through the GDF11-FTO-PPARγ axis, prompting the shift of MSC lineage commitment to adipocyte and inhibiting bone formation during osteoporosis. In this systematic review, we summarize the most up-to-date evidence of m6A RNA modification in osteoporosis and highlight the potential role of m6A in prevention, treatment, and management of osteoporosis.

METTL3 promotes ovarian carcinoma growth and invasion through the regulation of AXL translation and epithelial to mesenchymal transition.

OBJECTIVE: As the most prevalent internal modification in mammalian messenger RNA, N6­methyladenosine (m6A) plays an important role in posttranscriptional gene regulation. METTL3 is a key component of the m6A methyltransferase complex and has recently been shown to play important roles in cancer development and progression. The current study was aimed to explore the function and underlying mechanism of METTL3 in ovarian cancer. METHODS: METTL3 expression was assessed by immunohistochemistry in 162 ovarian carcinoma patients. Stable cell lines with METTL3 gene overexpression or knockdown were established to investigate the function of METTL3 in ovarian cancer in vitro and in vivo. RESULTS: METTL3 was frequently upregulated in ovarian carcinoma and that a high level of METTL3 was significantly associated with tumor grade (P = 0.001), pT status (P = 0.002), pN/pM status (P < 0.001), FIGO stage (P < 0.001), and overall survival rate (P < 0.001). Stable overexpression of METTL3 in the OVCAR3 and COV504 cell lines significantly increased cellular proliferation, focus formation, motility, invasion, and tumor formation in nude mice. Silencing METTL3 expression in the SKOV3 and HO-8910 cell lines with short hairpin RNA effectively inhibited its oncogenic function. Further study found that METTL3 promoted epithelial-mesenchymal transition (EMT) by upregulating the receptor tyrosine kinase AXL. CONCLUSION: Our findings suggest that METTL3 plays very important oncogenic roles in ovarian carcinoma development and/or aggressiveness by stimulating AXL translation and EMT and that METTL3 may serve as a novel prognostic and/or therapeutic target of interest in ovarian cancer.

miR-200c suppresses endometriosis by targeting MALAT1 in vitro and in vivo.

BACKGROUND: Endometriosis is a common, benign, and estrogen-dependent disease characterized by pelvic pain and infertility. To date, the pathogenesis of endometriosis remains unclear. Recent studies have demonstrated that noncoding RNAs, including microRNAs and long noncoding RNAs, play important roles in the development of endometriosis. METHODS: Expression profiling of miRNAs in endometrial tissue was characterized using microarrays. The most differentially expressed miRNAs were confirmed using quantitative reverse transcriptase-polymerase chain reaction analysis in additional ectopic endometrial (n = 27) and normal endometrial (n = 12) tissues. For in-vitro functional studies, 5-ethynyl-2'-deoxyuridine incorporation assay, Transwell assay, and dual-luciferase reporter assay were used to measure the proliferation, migration, and luciferase activity of miR-200c and the predicted targets of miR-200c in primary endometrial stromal cells (HESCs) derived from human endometrial biopsies, respectively. For in-vivo therapeutic interventions, polymeric nanoparticles of polyethylenimine-polyethylene glycol-arginine-glycine-aspartic acid were used for delivery of miR-200c mimic and inhibitor to determine the therapeutic effect of miR-200c in a rat model of endometriosis. RESULTS: Exogenous overexpression of miR-200c inhibited the proliferation and migration of HESCs, which were mainly regulated by metastasis-associated lung adenocarcinoma transcript 1 (MALAT1). In contrast, inhibition of miR-200c promoted the proliferation and migration of HESCs, while the simultaneous silencing of MALAT1 expression exerted the opposite effects. We demonstrated that expression of MALAT1 in ectopic endometrial specimens was negatively correlated with that of miR-200c and that MALAT1 knockdown increased the level of miR-200c in HESCs. Moreover, the transfection of endometrial stromal cells with the miR-200c mimic or MALAT1 siRNAs decreased the protein levels of mesenchymal markers ZEB1, ZEB2, and N-cadherin and increased the protein levels of the epithelial marker E-cadherin. Furthermore, using a rat endometriosis model, we showed that local delivery of the miR-200c mimic significantly inhibited the growth of ectopic endometriotic lesions. CONCLUSIONS: The MALAT1/miR-200c sponge may be a potential therapeutic target for endometriosis.

MDM2 promoter del1518 polymorphism and cancer risk: evidence from 22,931 subjects.

Studies have shown that single-nucleotide polymorphisms in MDM2 gene may play important roles in the development of malignant tumor. The association of del1518 polymorphism (rs3730485) in the MDM2 promoter with cancer susceptibility has been extensively studied; however, the results are contradictory. To quantify the association between this polymorphism and overall cancer risk, we conducted a meta-analysis with 12,905 cases and 10,026 controls from 16 eligible studies retrieved from PubMed, Embase, and Chinese Biomedical (CBM) databases. We assessed the strength of the connection using odds ratios (ORs) and 95% confidence intervals (CIs). In summary, no significant associations were discovered between the del1518 polymorphism and overall cancer risk (Del/Del vs Ins/Ins: OR =1.01, 95% CI =0.90-1.14; Ins/Del vs Ins/Ins: OR =1.03, 95% CI =0.96-1.12; recessive model: OR =0.98, 95% CI =0.90-1.07; dominant model: OR =1.03, 95% CI =0.94-1.12; and Del vs Ins: OR =1.01, 95% CI =0.94-1.07). In the stratified analysis by source of control, quality score, cancer type, and ethnicity, no significant associations were found. Despite some limitations, the current meta-analysis provides solid statistical evidence of lacking association between the MDM2 del1518 polymorphism and cancer risk.

Bone Marrow-Derived MicroRNA-223 Works as an Endocrine Genetic Signal in Vascular Endothelial Cells and Participates in Vascular Injury From Kawasaki Disease.

BACKGROUND: Kawasaki disease (KD) is now the most common cause of acquired cardiac disease in children due to permanent coronary artery damage with unknown etiology. The study sought to determine the role of blood microRNA miR-223 in KD and KD-induced injuries in vascular endothelial cells (ECs) as well as the mechanisms involved. METHODS AND RESULTS: MicroRNA profiles in serum from patients with KD and from healthy controls were assessed by microarray analysis. We noted that multiple serum microRNAs were aberrantly expressed in KD, among them miR-223, which was the most upregulated abundant serum microRNA. We found that bone marrow-derived blood cells (leukocytes and platelets) were able to secrete miR-223 into serum. Vascular ECs had no endogenous miR-223; however, the blood cell-secreted serum miR-223 could enter into the vascular ECs in the vascular walls. The exogenous miR-223 had strong biological effects on EC functions via its target genes such as IGF1R. Interestingly, KD-induced EC injuries were related to increased miR-223 because they were inhibited by miR-223 knockdown. Finally, these observations were verified using miR-223 knockout mice and the chimeric mice generated by transplantation of bone marrow from miR-223 knockout mice into wild-type mice. CONCLUSIONS: In KD patients, the levels of blood cell-derived miR-223 in ECs are significantly increased. The increased miR-223 in ECs could work as a novel endocrine genetic signal and participate in vascular injury of KD. MiR-223 may provide a novel mechanism and a new therapeutic target for vascular complication of KD.

RBM24 suppresses cancer progression by upregulating miR-25 to target MALAT1 in nasopharyngeal carcinoma.

Abnormal interaction between non-coding RNAs has been demonstrated to be a common molecular event in various human cancers, but its significance and underlying mechanisms have not been well documented. RNA-binding proteins (RBPs) are key regulators of RNA transcription and post-transcriptional processing. In this study, we found that RNA-binding protein 24 (RBM24) was frequently downregulated in nasopharyngeal carcinoma (NPC). The restoration of RBM24 expression suppressed NPC cellular proliferation, migration and invasion and impeded metastatic colonization in mouse models. Microarray analyses revealed that miR-25 expression was upregulated by RBM24 expression in NPC cells. Similarly, ectopic miR-25 expression suppressed NPC cellular growth and motility by targeting the pro-oncogenic lncRNA MALAT1, and the knockdown of MALAT1 expression exhibited similar effects as RBM24 restoration in NPC cells. Overall, these findings suggest a novel role of RBM24 as a tumor suppressor. Mechanistically, RBM24 acts at least in part through upregulating the expression of miR-25, which in turn targets MALAT1 for degradation.

Expression of EIF5A2 associates with poor survival of nasopharyngeal carcinoma patients treated with induction chemotherapy.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a type of head-neck cancer with a distinguishable geographic and racial distribution worldwide. Increasing evidence supports that the accumulation of additional genetic and epigenetic abnormalities is important in driving the NPC tumorigenic process. In this study, we aim to investigate the association between EIF5A2 (Eukaryotic translation initiation factor 5A2) expression status and NPC clinical outcomes. METHODS: The expression status of EIF5A2 was investigated in the NPC tissue microarray. Tissues were from 166 NPC patients staging II-IV, collected between 1999 and 2005. All patients were administered 2-3 cycles of DDP (cisplatin) + 5-Fu (5-fluorouracil) induction therapy and then treated with a uniform conventional two-dimensional radiotherapy. Cell motility assay, tumor growth assay and cytotoxicity assay were performed on the EIF5A2 overexpressed cells and control cells. siRNA was also used in the in vitro studies. RESULTS: Positive staining of EIF5A2 was observed in 85.4 % (105/123) informative tumor cases. Multivariate analyses demonstrated that EIF5A2 was an independent prognostic marker of poor overall survival (OS) (P = 0.041), failure-free survival (FFS) (P = 0.029), and distant failure-free survival (D-FFS) (P = 0.043) in patients with locoregionally advanced NPC patients treated with cisplatin + 5-Fu chemoradiotherapy. The forced expression of EIF5A2 in NPC cells enhanced the cells' motility and growth ability. Knock-down of EIF5A2 in NPC cells decreased the cell's motility and growth ability. Our results also demonstrated that EIF5A2 overexpression induced chemoresistance of NPC cells to 5-Fu. CONCLUSIONS: Our findings suggested that EIF5A2 expression, as examined by immunohistochemistry, could function as an independent prognostic factor of outcomes in NPC patients with cisplatin + 5-Fu chemoradiotherapy. EIF5A2 might be a novel therapeutic target for the inhibition of NPC progress.

Aldehyde dehydrogenase 1A1 up-regulates stem cell markers in benzo[a]pyrene-induced malignant transformation of BEAS-2B cells.

Recently, Aldehyde dehydrogenase 1A1 (ALDH1A1) has been proposed to be a common marker of cancer stem cells and can be induced by benzo[a]pyrene (B[a]P) exposure. However, the underlying mechanism of how ALDH1A1 contributes to B[a]P-induced carcinogenesis in human bronchial epithelial cells remains unclear. Here, we found that B[a]P up-regulated expression levels of stem cell markers (ABCG2, SOX2, c-Myc and Klf4), epithelial-mesenchymal transition (EMT) associated genes (SNAIL1, ZEB1, TWIST and ß-CATENIN) and cancer-related long non-coding RNAs (lncRNAs; HOTAIR and MALAT-1) in malignant B[a]P-transformed human bronchial epithelial cells (BEAS-2B-T cells), and these up-regulations were dependent on increased expression of ALDH1A1. The inhibition of endogenous ALDH1A1 expression down-regulated expression levels of stem cell markers and reversed the malignant phenotype as well as reduced the chemoresistance of BEAS-2B-T cells. In contrast, the overexpression of ALDH1A1 in BEAS-2B cells increased the expression of stem cell markers, facilitated cell transformation, promoted migratory ability and enhanced the drug resistance of BEAS-2B cells. Overall, our data indicates that ALDH1A1 promotes a stemness phenotype and plays a critical role in the BEAS-2B cell malignant transformation induced by B[a]P.

BRCC3 acts as a prognostic marker in nasopharyngeal carcinoma patients treated with radiotherapy and mediates radiation resistance in vitro.

BACKGROUND: BRCC3 has been found to be aberrantly expressed in breast tumors and involved in DNA damage response. The contribution of BRCC3 to nasopharyngeal carcinoma prognosis and radiosensitivity is still unclear. METHODS: Immunohistochemical analysis of BRCC3 was carried out in 100 nasopharyngeal carcinoma tissues, and the protein level was correlated to patient survival. BRCC3 expression of nasopharyngeal carcinoma cell lines was determined by Western-blotting and real-time PCR. Additionally, the effects of BRCC3 knockdown on nasopharyngeal carcinoma cell clongenic survival, DNA damage repair, and cell cycle distribution after irradiation was assessed. RESULTS: The BRCC3 protein level was inversely correlated with nasopharyngeal carcinoma patient overall survival (P < 0.001) and 3-year loco-regional relapse-free survival (P = 0.034). Multivariate analysis demonstrated that BRCC3 expression was an independent prognostic factor (P = 0.010). The expression of BRCC3 was much higher in radioresistant nasopharyngeal carcinoma cells than in radiosensitive cells. Knockdown of BRCC3 increased the cell survival fraction, attenuated DNA damage repair and resulted in G2/M cell cycle arrest in radioresistant NPC cells. CONCLUSIONS: High BRCC3 expression in nasopharyngeal carcinoma patients is associated with poor survival. BRCC3 knockdown could abate the radioresistance in nasopharyngeal carcinoma cells. These findings suggest the utility of BRCC3 as a prognostic biomarker and novel target for nasopharyngeal carcinoma.

[Distribution of HCV genotypes in volunteer blood donors in Guangzhou].

OBJECTIVE: To determine the distribution of HCV genotypes among volunteer blood donors in Guangzhou. METHODS: Six-nine HCV RNA-positive samples were collected from volunteer blood donors in Guangzhou. NS5B fragments of HCV were amplified followed by DNA sequencing and phylogenetic analysis. RESULTS: HCV genotypes were determined for 67 samples. Among them, the subtypes 1b, 2a, 3a, 3b, 6a and 6n were detected at the frequencies of 37.31%, 4.48%, 7.46%, 4.48%, 44.78% and 1.49%, respectively. CONCLUSION: HCV 1b and 6a are the most predominant two subtypes among volunteer blood donors in Guangzhou.