Next-generation sequencing based detection of BRCA1 and BRCA2 large genomic rearrangements in Chinese cancer patients.

BRCA1/2 mutation is a biomarker for guiding multiple solid tumor treatment. However, the prevalence of BRCA1/2 large genomic rearrangements (LGRs) in Chinese cancer patients has not been well revealed partially due to technical difficulties in LGR detection. This study utilized next-generation sequencing (NGS) to analyze the BRCA1/2 mutation profile, including LGR, in 56126 Chinese cancer patients. We also reported that two ovarian and breast cancer patients with NGS-determined BRCA1/2 LGR benefited from PARP inhibitors (PARPi). DNA sequencing identified BRCA1/2 variants (including LGR, pathogenic and likely-pathogenic variants) in 2108 individuals. Seventy patients were discovered to harbor germline LGRs in BRCA1 and 14 had germline LGRs in BRCA2. Among the LGRs detected, exon 1-2 deletion was the predominant LGR (14/70) in BRCA1, and exon 22-24 deletion was the most frequent LGR (3/14) in BRCA2. Notably, the BRCA1 exon 7 deletion was a novel LGR and was identified in six patients, suggesting a specific LGR in Chinese cancer patients. The prevalence analysis of BRCA1 and BRCA2 LGRs across multiple cancers revealed that BRCA1 LGR more frequently occurred in ovarian cancer (1.31%, 33/2526), and BRCA2 LGR was more commonly seen in cholangiocarcinoma (0.47%, 2/425). Two ovarian and breast cancer patients with BRCA1/2 LGR benefited from PARPi therapy. This is the first study to reveal the BRCA1/2 LGR profile of a Chinese pan-cancer cohort by using an NGS-based assay. Two breast and ovarian cancer patients harboring NGS-determined BRCA1/2 LGR benefited from PARPi, indicating that NGS-based detection of BRCA1/2 LGR has the potential to guide PARPi treatment.

Improving arm segmentation in sign language recognition systems using image processing.

BACKGROUND: For a traditional vision-based static sign language recognition (SLR) system, arm segmentation is a major factor restricting the accuracy of SLR. OBJECTIVE: To achieve accurate arm segmentation for different bent arm shapes, we designed a segmentation method for a static SLR system based on image processing and combined it with morphological reconstruction. METHODS: First, skin segmentation was performed using YCbCr color space to extract the skin-like region from a complex background. Then, the area operator and the location of the mass center were used to remove skin-like regions and obtain the valid hand-arm region. Subsequently, the transverse distance was calculated to distinguish different bent arm shapes. The proposed segmentation method then extracted the hand region from different types of hand-arm images. Finally, the geometric features of the spatial domain were extracted and the sign language image was identified using a support vector machine (SVM) model. Experiments were conducted to determine the feasibility of the method and compare its performance with that of neural network and Euclidean distance matching methods. RESULTS: The results demonstrate that the proposed method can effectively segment skin-like regions from complex backgrounds as well as different bent arm shapes, thereby improving the recognition rate of the SLR system.

Derlin-1 exhibits oncogenic activities and indicates an unfavorable prognosis in breast cancer.

Derlin-1 is involved in the elimination of misfolded proteins and has been implicated in the progression of human cancers. However, its prognostic value and biological function in breast cancer remain unknown. Here, we show that Derlin-1 is overexpressed in breast cancer and exhibits oncogenic activities via interaction with UBE2C. Increased expression of Derlin-1 is correlated with lymph node metastasis, advanced clinical stage, and unfavorable overall survival in two cohorts containing over 1,000 patients. Multivariate analyses by the Cox regression model suggest Derlin-1 is an independent factor for poor prognosis. In vitro experiments demonstrate that Derlin-1 expression is transcriptionally upregulated by c-Myc. Ectopic expression of Derlin-1 promotes breast cancer cell proliferation and migration, whereas the knockdown of Derlin-1 results in the opposite phenotypes. Mechanistically, Derlin-1 directly binds to UBE2C to increase the phosphorylation of AKT and ERK. The treatment of UBE2C siRNA markedly attenuates Derlin-1-mediated cell growth and migration. Collectively, our data suggest Derlin-1 is a potential prognostic factor and functions as an oncogene in breast cancer.

Recurrent epithelioid malignant peripheral nerve sheath tumor with neurofibromatosis type 1: A case report and literature review.

Malignant peripheral nerve sheath tumors (MPNSTs) are unusual and aggressive malignant soft-tissue tumors that comprise 5-10% of all soft-tissue sarcomas. Approximately 50% of MPNST cases are associated with neurofibromatosis type-1 (NF-1). As a rare MPNST subset, the epithelioid variant of MPNST (eMPNST) is histologically characterized by the predominant presence of epithelioid tumor cells, and accounts for <5% of all MPNSTs. In addition, eMPNST is rarely associated with NF-1 when compared with conventional MPNST. Although extensive clinicopathological studies have been conducted on eMPNST, clinicians face difficulty when attempting to make an accurate diagnosis. Subsequently, the biological consequences, including recurrence, metastasis and mortality rate in patients with eMPNST remain unclear. The current study presents the case of a 71-year-old woman with eMPNST and a family history of NF-1 in whom tumors had recurred twice on the lower back. A literature search for eMPNSTs was conducted by browsing PubMed and MEDLINE for English-language articles, as well as references from review articles, and revealed 129 published cases. Only 5 cases of eMPNST were associated with NF-1. The studies were retrospectively reviewed and the clinicopathological data of the patients, including tumor site, treatment, follow-up, prognosis, and immunohistochemical positivity were collected.

METTL1 overexpression is correlated with poor prognosis and promotes hepatocellular carcinoma via PTEN.

RNA methylation is emerging as an important regulator of gene expression. Dysregulation of methyltransferase that is essential for RNA modification contributes to the development and progression of human cancers. Here we show that methyltransferase-like 1 (METTL1) is upregulated in hepatocellular carcinoma (HCC) and exhibits oncogenic activities via PTEN/AKT signaling pathway. High expression of METTL1 is correlated with larger tumor size, higher serum AFP level, tumor vascular invasion, and poor prognosis in two independent cohorts containing 892 patients with HCC. Multivariate analyses suggest METTL1 as an independent factor for unfavorable overall survival. In vitro studies demonstrate that METTL1 overexpression promotes cell proliferation and migration, whereas its knockdown results in opposite phenotypes. Gene set enrichment analysis (GSEA) indicates PTEN pathway is activated in patients with low METTL1 expression. Ectopic expression of PTEN or inhibition of AKT activity significantly attenuates the METTL1-mediated malignant phenotypes. In clinical samples, METTL1 expression is reversely associated with PTEN expression. Combination of low METTL1 expression and high PTEN expression is significantly correlated with overall survival, more so than either METTL1 or PTEN expression alone. Collectively, our data suggest that METTL1 serves as a promising prognostic biomarker and that targeting METTL1/PTEN axis may provide therapeutic potential in HCC intervention. KEY MESSAGES: METTL1 is upregulated in HCC and correlated with poor outcomes. METTL1 promotes cell proliferation and migration in HCC. METTL1 exerts oncogenic activities via suppression of PTEN signaling.

SPAG5 interacts with CEP55 and exerts oncogenic activities via PI3K/AKT pathway in hepatocellular carcinoma.

BACKGROUND: Deregulation of microtubules and centrosome integrity is response for the initiation and progression of human cancers. Sperm-associated antigen 5 (SPAG5) is essential for the spindle apparatus organization and chromosome segregation, but its role in hepatocellular carcinoma (HCC) remains undefined. METHODS: The expression of SPAG5 in HCC were examined in a large cohort of patients by RT-PCR, western blot and IHC. The clinical significance of SPAG5 was next determined by statistical analyses. The biological function of SPAG5 in HCC and the underlying mechanisms were investigated, using in vitro and in vivo models. RESULTS: Here, we demonstrated that SPAG5 exhibited pro-HCC activities via the activation of PI3K/AKT signaling pathway. SPAG5 expression was increased in HCC and correlated with poor outcomes in two independent cohorts containing 670 patients. High SPAG5 expression was associated with poor tumor differentiation, larger tumor size, advanced TNM stage, tumor vascular invasion and lymph node metastasis. In vitro and in vivo data showed that SPAG5 overexpression promoted tumor growth and metastasis, whereas SPAG5 knockdown led to the opposite phenotypes. SPAG5 interacted with centrosomal protein CEP55 to trigger the phosphorylation of AKT at Ser473. Inhibition of PI3K/AKT signaling markedly attenuated SPAG5-mediated cell growth. Furthermore, SPAG5 expression was suppressed by miR-363-3p which inhibited the activity of SPAG5 mRNA 3'UTR. Ectopic expression of SPAG5 partly abolished the miR-363-3p-caused cell cycle arrest and suppression of cell proliferation and migration. CONCLUSIONS: Collectively, these findings indicate that SPAG5 serves a promising prognostic factor in HCC and functions as an oncogene via CEP55-mediated PI3K/AKT pathway. The newly identified miR-363-3p/SPAG5/CEP55 axis may represent a potential therapeutic target for the clinical intervention of HCC.

CBX1 Indicates Poor Outcomes and Exerts Oncogenic Activity in Hepatocellular Carcinoma.

Dysregulation of chromobox proteins contributes to the progression of human diseases. CBX1 has been implicated in epigenetic control of chromatin structure and gene expression, but its role in human cancers remains largely unknown. Here we show that CBX1 exhibits oncogenic activities in hepatocellular carcinoma (HCC) and indicates poor outcomes. The expression of CBX1 was noticeably increased, at both mRNA and protein levels, in HCC tissues and cell lines, compared with the nontumorous ones. High CBX1 expression was significantly associated with larger tumor size, poor tumor differentiation and tumor vascular invasion. Patients with elevated expression of CBX1 were frequently accompanied with unfavorable overall and disease-free survivals in two independent cohorts consisting of 648 HCC cases. The prognostic value of CBX1 was further confirmed by stratified survival analyses. Multivariate cox regression model suggested CBX1 as an independent factor for overall survival (hazard ratio = 1.735, 95% confident interval: 1.342-2.244, P < .001). In vitro data demonstrated that CBX1 overexpression promoted cell proliferation and migration, whereas the knockdown of CBX1 resulted in the opposite phenotypes. Mechanistically, CBX1 interacted with transcription factor HMGA2 to activate the Wnt/ß-Catenin signaling pathway. Suppression of ß-Catenin by siRNA or specific inhibitor XAV-939 markedly attenuated CBX1-mediated cell growth. Collectively, our findings indicate that CBX1 functions as an oncogene and may serve as a potential prognostic biomarker in HCC.

CBX4 exhibits oncogenic activities in breast cancer via Notch1 signaling.

Polycomb chromobox (CBX) proteins are involved in gene silencing to function as oncogenes or tumor suppressors through the polycomb repressive complex (PRC1). CBX4 has been implicated in the progression of human cancers, but its role and clinical significance in breast cancer remain unclear. Here, we show that CBX4 is up-regulated in breast cancer and exerts oncogenic activities via miR-137-mediated activation of Notch1 signaling pathway. CBX4 expression was increased in breast cancer, compared with the nontumorous tissues. High CBX4 expression was closely correlated with tumor metastasis, advanced clinical stage and poor overall survival in a cohort of 179 patients with breast cancer. In vitro studies demonstrated that CBX4 overexpression enhanced, whereas CBX4 knockdown inhibited cell growth and migration. Mechanistically, in a PRC1-dependent manner, CBX4 inhibited the promoter activity of miR-137 and suppressed its expression. miR-137 decreased the expression of Notch1, Jag1 and Hey2 via targeting their 3'-UTRs. The suppression of Notch1 by siRNA or overexpression of miR-137 markedly attenuated CBX4-promoted phenotypes. Collectively, these findings indicate that CBX4 promotes breast cancer via miR-137-mediated Notch1 signaling. Our data, therefore, suggest that CBX4 serve as a prognostic biomarker and that targeting CBX4/miR-137 axis may provide therapeutic potent in the treatment of breast cancer.

Effect of antitumor treatments on triple-negative breast cancer patients: A PRISMA-compliant network meta-analysis of randomized controlled trials.

BACKGROUND: Triple-negative breast cancer (TNBC) lacks the expression of the estrogen receptor, progesterone receptor, and receptor tyrosine-protein kinase erbB-2 (HER2/neu), which renders hormone-related endocrine and targeted therapy essentially futile. OBJECTIVE: We performed a meta-analysis to assess the effects of antitumor regimens in the treatment of TNBC patients. METHODS: We searched electronic databases, including PubMed, Embase, and the Cochrane Library, through January 2017 using the following keywords: "triple negative breast cancer," "TNBC," and "random*" without language restrictions. The major outcome in the present analysis was the overall response rate (ORR), and the secondary outcomes were progression-free survival (PFS) and overall survival (OS). A network meta-analysis and multilevel mixed-effects logistic regression were used to compare antitumor regimens. RESULTS: We included 35 articles assessing a total of 8476 TNBC patients in our systematic review. The regimen of Bevacizumab, Carboplatin, and Paclitaxel (78.2%) was the most likely to improve the ORR in TNBC patients, followed by EndoTAG-1 and Paclitaxel (69.7%), Carboplatin and Paclitaxel (65.0%), and Bevacizumab and Paclitaxel (61.8%). In the patients without metastasis, the regimen of Bevacizumab, Carboplatin, and Paclitaxel (74.9%) remained the most likely to improve the ORR. We could not analyze the results for patients with metastasis or outcomes of PFS and OS because no >4 regimens formed a network. In the regression analysis, Bevacizumab (odds ratio [OR], 1.71; 95% confidence interval [CI], 1.43-2.05; P < .001) and Carboplatin (OR, 2.07; 95% CI, 1.62-2.64; P < .001) correlated with superior ORR outcome, and Iniparib (OR, 1.51; 95% CI, 1.11-2.07; P = .009) correlated with superior OS outcome. CONCLUSION: The regimen including Bevacizumab, Carboplatin, and Paclitaxel was the most likely to improve the ORR in TNBC patients and in advanced metastatic TNBC patients. The administration of Bevacizumab and Carboplatin provided greater benefit toward improved patient ORR.

TRIM65 triggers ß-catenin signaling via ubiquitylation of Axin1 to promote hepatocellular carcinoma.

Deregulation of ubiquitin ligases contributes to the malignant progression of human cancers. Tripartite motif-containing protein 65 (TRIM65) is an E3 ubiquitin ligase and has been implicated in human diseases, but its role and clinical significance in hepatocellular carcinoma (HCC) remain unknown. Here, we showed that TRIM65 expression was increased in HCC tissues and associated with poor outcome in two independent cohorts containing 888 patients. In vitro and in vivo data demonstrated that overexpression of TRIM65 promoted cell growth and tumor metastasis, whereas knockdown of TRIM65 resulted in opposite phenotypes. Further studies revealed that TRIM65 exerted oncogenic activities via ubiquitylation of Axin1 to activate the ß-catenin signaling pathway. TRIM65 directly bound to Axin1 and accelerated its degradation through ubiquitylation. Furthermore, HMGA1 was identified as an upstream regulator of TRIM65 in HCC cells. In clinical samples, TRIM65 expression was positively correlated with the expression of HMGA1 and nuclear ß-catenin. Collectively, our data indicate that TRIM65 functions as an oncogene in HCC. The newly identified HMGA1/TRIM65/ß-catenin axis serves as a promising prognostic factor and therapeutic target.

PDZ binding kinase, regulated by FoxM1, enhances malignant phenotype via activation of ß-Catenin signaling in hepatocellular carcinoma.

Deregulation of serine/threonine kinase contributes to the development and progression of human diseases. PDZ-binding kinase (PBK) has been implicated in the malignant process of cancers, but its role and clinical significance in hepatocellular carcinoma (HCC) remains unclear. Here we show that PBK expression is increased and associated with larger tumor size, presence of vascular invasion, lymph node metastasis and poor overall and disease-free survivals in two independent cohorts of 879 patients with HCC. In vitro and in vivo data demonstrate PBK exerts oncogenic functions in HCC via activation of ß-Catenin signaling pathway. The inhibition of ß-Catenin by siRNAs or XAV-939 significantly attenuates PBK-mediated malignant phenotypes. PBK is further identified as a downstream effector of FoxM1. In clinical samples, PBK expression is positively correlated with the expression of FoxM1 and nuclear ß-Catenin. Collectively, these findings suggest PBK functions as an oncogene in HCC and the newly identified FoxM1/PBK/ß-Catenin axis serves as a promising prognostic factor as well as therapeutic intervention for HCC.

DHX33 expression is increased in hepatocellular carcinoma and indicates poor prognosis.

DEAH-box helicase 33 (DHX33) has been implicated in ribosome biogenesis, mRNA translation and inflammation. However, the role of DHX33 in human cancer is rarely studied. Here, we showed that DHX33 expression was significantly increased in hepatocellular carcinoma (HCC), compared with the adjacent nontumorous tissues. In a cohort of 520 patients, DHX33 expression in HCC was closely associated with tumor size (P = 0.007), serum AFP level (P = 0.011), and tumor capsule (P = 0.030). Kaplan-Meier analysis indicated high DHX33 expression was correlated with worse overall and disease-free survival, and higher recurrence rate. The prognostic value of DHX33 was further confirmed by stratified survival analysis. Multivariate analysis revealed DHX33 as an independent prognostic factor for poor overall survival (Hazard Ratio = 1.772, 95% confident interval: 1.451-2.165, P < 0.0001). Our data therefore suggest DHX33 is overexpressed in HCC and serves as a promising prognostic biomarker for this deadly disease.

Clinical pathology of metastatic gastric carcinoma to the breast: A report of two cases and a review of literature.

The breast is an unusual site for metastasis from a gastric carcinoma. The present study reports two cases of metastatic gastric carcinoma to the breast. The first patient, a 37-year-old woman, initially presented with gastric adenocarcinoma, prior to developing metastatic cancer to the breast 4 years later. The second female patient presented with a breast mass, and a modified radical mastectomy was performed; however, the subsequent pathological examination revealed the mass to be a metastatic signet ring cell carcinoma. An abdominal computed tomography scan revealed a diffuse gastric wall thickening that was consistent with gastric cancer. The findings suggest that immunohistochemistry is a useful tool to differentiate between primary breast tumors and gastrointestinal carcinomas that have metastasized to the breast. Additional studies are required in order to define the optimal treatment.

[Analysis of OCRL gene mutation in a male infant with Lowe syndrome].

OBJECTIVE: To identify pathological mutation in a Chinese male infant featuring oculocerebrorenal syndrome (also called Lowe syndrome). METHODS: Clinical data of the patient were collected. DNA was extracted from peripheral blood of the infant and his parents. All of the 24 exons and intron-exon splice sites of OCRL gene were amplified with PCR. Mutations were detected by direct sequencing the PCR products. RESULTS: The infant was found to have carried a c.1499G>A (p.R500Q) mutation in exon 15 of the OCRL gene, which was transmitted from his mother, who was heterozygous for the same mutation. The c.1499G>A mutation, discovered in Chinese population for the first time, has been reported to cause severe Lowe syndrome in other ethnic populations. CONCLUSION: The c.1499G>A mutation of the OCRL gene is probably responsible for the disease in the patient. Further study of this mutation may facilitate delineation of the genotype-phenotype correlation of this disease.

The Hb H disease genotypes in Southern China.

Abstract We report the genetic data of 435 patients with Hb H (ß4) disease who presented at our center between 2005 and 2012. Our results showed that all patients had the Southeast Asian deletion (- -(SEA)) on one allele. The -α(3.7) (rightward) deletion was the most common on the other allele, followed by the -α(4.2) (leftward) deletion, Hb Constant Spring (Hb CS, α142, Term → Gln; HBA2: c.427T > C) and Hb Quong Sze [Hb QS, α125(H8)Leu → Pro; HBA2: c.377T > C] mutations. Two rare point mutations, α31(B12)Arg → Lys; HBA2: c.95G > A and Hb Zurich Albisrieden [α59(E8)Gly → Arg; HBA1: c.178G > C], were also identified. Four patients had a concomitant ß-thalassemia (ß-thal) heterozygosity. Our results reflect the genetic heterogeneity of Hb H disease and the interaction between Hb H disease and ß-thal trait in Southern China.

[Genotype of thalassemia genes and the polymorphism of ß- globin gene in Cantonese].

OBJECTIVE: To understand the genotype of α and ß-globin, as well as the polymorphism of ß-globin gene in Cantonese in recent years, and to provide an effective genetic diagnosis for thalassemia (thal). METHODS: The single-tube complex PCR was used to detect 3 types of deletional α-thal, reverse dot blotting (RDB)/PCR to detect 3 kinds of undeletional α-thal-αCS, αQS, αWSand 18 kinds of ß-thal mutations which were common in Chinese population. A total of 454 cases from Guangdong were undergone thal genotype genetic diagnosis. Among the 454 cases, 142 cases were selected to perform the single nucleotide polymorphisms (SNPs) analysis of ß- globin gene by denaturing high-performance liquid chromatography (DHPLC)combining the whole gene sequencing. RESULTS: Of the 454 cases, 438 were diagnosed as thalassemia, including 246 of α-thal, 164 of ß-thal and 28 of αß-thal. In 246 α-thal cases, deletions were the dominant mutations, including 197 cases of αα/--(SEA), 20 of αα/-α(3.7) and 9 of αα/-α(4.2). In 164 ß- thal cases, heterozygotes accounted for 92.7% (152/164), the main genotypes were CD41- 42, IVS-II-654, ï¹£28 and CD17, and the dual heterozygotes and homozygotes accounted for 4.9% (8/164) and 2.4% (4/164), respectively. The result of ß-globin gene screening by DHPLC combining with sequencing was consistent with that of RDB. Moreover, we also found 9 kinds of SNP, in which 2 were unreported, the IVS-I-13 G> A and IVS-II- 310 T>C. In the tested samples, the frequency of 4 kinds SNP was high, among which 3 kinds SNPs-rs713040, rs10768683 and rs1609812 were carried together. CONCLUSION: The dominant genotypes were αα/--(SEA) in α-thal cases, CD41-42, IVS-II-654, -28 and CD17 in ß-thal. The frequency of ß-thal heterozygotes, homozygotes and αß-thal is high. DHPLC combining the whole ß-globin gene sequencing can effectively detect the common ß-thal mutation and even new mutations or SNPs. In Cantonese, the frequency of SNP rs713040, rs10768683, rs7480526 and rs1609812 of ß-globin gene was high, and there may exist genetic linkage between rs713040, rs10768683 and rs1609812.

Primary small cell carcinoma of the esophagus: clinicopathological and immunohistochemical features of 21 cases.

BACKGROUND: Primary small cell carcinoma (SCC) of the esophagus is a rare and aggressive tumor with poor prognosis. In this study, we report the clinicopathological characteristics of 21 cases of small cell carcinoma of the esophagus treated at the Cancer Center of Sun Yat-Sen University, with particular focus on the histologic and immunohistochemical findings. METHODS: Twenty-one patient records were reviewed including presenting symptoms, demographics, disease stage, treatment, and follow-up. Histologic features were observed and immunohistochemical detection of cytokeratin (CK), epithelial membrane antigen (EMA), neuron specific enolase (NSE), synaptophysin (Syn), chromogranin A (CgA), neuronal cell adhesion molecules (CD56), thyroid transcriptional factor-1 (TTF-1) and S100 protein (S100) was performed. RESULTS: The median age of patients in the study was 56 years, with a male-to-female ratio of 3.2:1. Histologically, there were 19 "homogenous" SCC esophageal samples and 2 samples comprised of SCC and well-differentiated squamous cell carcinoma. The percentages of SCC samples with positive immunoreactivity were Syn 95.2%, CD56 76.2%, TTF-1 71.4%, NSE 61.9%, CgA 61.9%, CK 57.1%, EMA 61.9%, and S100 19.0%, respectively. The median patient survival time was 18.3 months after diagnosis. The 2-year survival rate was 28.6%. CONCLUSION: Our study suggests that esophageal SCC has similar histology to SCC that arises in the lung compartment, and Chinese patients have a poor prognosis. Higher proportion of positive labeling of Syn, CD56, CgA, NSE, and TTF-1 in esophageal SCC implicate that they are valuably applied in differential diagnosis of the malignancy.

[High expression of nucleophosmin/B23 in hepatocellular carcinoma].

OBJECTIVE: To study the expression of nucleophosmin/B23 (B23) in tumor cells of hepatocellular carcinoma (HCC) and its clinicopathologic significance. METHODS: Mouse monoclonal antibodies against B23 were raised by recombinant protein and hybridoma technology. Immunohistochemical study for B23 was performed on 103 cases of HCC, 12 cases of focal nodular hyperplasia and 17 cases of native liver tissue adjacent to hepatic hemangioma. Fresh specimens from 10 cases of HCC and the adjacent liver tissue were also collected for reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis. The expression of B23 was analyzed and compared with that of proliferative cell nuclear antigen (PCNA) in these specimens. RESULTS: RT-PCR and Western blot analysis showed that B23 expression in HCC was higher than that in adjacent liver tissue. Statistically significant difference in expressions of B23 and PCNA were also noted in the four groups studied (P < 0.01). B23 and PCNA expressions in HCC were higher than those in the other three groups (P < 0.01). There was also a statistically significant correlation between B23 and PCNA expressions amongst the four groups (r = 0.4769, P < 0.01). Besides, B23 expression in HCC correlated with pathologic tumor grading, serum alpha-fetal protein levels and cirrhotic status (P < 0.05). CONCLUSIONS: B23 expression in HCC was significantly higher than that in liver tissues with non-malignant diseases. B23 may be used as a marker for neoplastic changes in liver cells and thus has potential clinicopathologic application.

Structure and function of glucose-6-phosphate dehydrogenase-deficient variants in Chinese population.

A systematic study on the structure and function of Glucose-6-phosphate dehydrogenase (G6PD) variations was carried out in China. A total of 155,879 participants were screened for G6PD deficiency by the G6PD/6PGD ratio method and 6,683 cases have been found. The prevalence of G6PD deficiency ranged from 0 to 17.4%. With informed consent, 1,004 cases from 11 ethnic-based groups were subjected to molecular analysis. Our results showed the followings: (1) The G6PD variants are consistent across traditional ethnic boundaries, but vary in frequencies across ethnic-based groups in Chinese population, (2) The G6PD variants in Chinese population are different from those in African, European, and Indian populations, (3) A novel G6PD-deficiency mutation, 274C-->T, has been found, and (4) Denaturing high performance liquid chromatography is of great advantage to detecting G6PD-deficient mutations for diagnosis and genetic counseling. Moreover, functional analysis of the human G6PD variants showed the following: (1) The charge property, polarity, pK-radical and side-chain radical of the substituting amino acid have an effect on G6PD activity, (2) The G6PDArg459 and Arg463 play important roles in anchoring NADP+ to the catalytic domain to maintain the enzymatic activity, and (3) The sequence from codon 459 to the carboxyl terminal is essential for the enzymatic function.