Chemical Modification, Characterization, and Activity Changes of Land Plant Polysaccharides: A Review.

Plant polysaccharides are widely found in nature and have a variety of biological activities, including immunomodulatory, antioxidative, and antitumoral. Due to their low toxicity and easy absorption, they are widely used in the health food and pharmaceutical industries. However, low activity hinders the wide application. Chemical modification is an important method to improve plant polysaccharides' physical and chemical properties. Through chemical modification, the antioxidant and immunomodulatory abilities of polysaccharides were significantly improved. Some polysaccharides with poor water solubility also significantly improved their water solubility after modification. Chemical modification of plant polysaccharides has become an important research direction. Research on the modification of plant polysaccharides is currently increasing, but a review of the various modification studies is absent. This paper reviews the research progress of chemical modification (sulfation, phosphorylation, acetylation, selenization, and carboxymethylation modification) of land plant polysaccharides (excluding marine plant polysaccharides and fungi plant polysaccharides) during the period of January 2012-June 2022, including the preparation, characterization, and biological activity of modified polysaccharides. This study will provide a basis for the deep application of land plant polysaccharides in food, nutraceuticals, and pharmaceuticals.

Diversity Patterns of Bermuda Grass along Latitudinal Gradients at Different Temperatures in Southeastern China.

Cynodon dactylon (L.) Pers. (common Bermuda grass) has a limited capacity to grow at low temperatures, which limits its geographical range. Exploring its evolutionary relationship across different environmental gradients is necessary to understand the effects of temperature change on the genetics of common Bermuda grass. In this study, high-throughput transcriptome sequencing was performed on 137 samples of C. dactylon from 16 latitudinal gradients to explore the differential molecular markers and analyze genetic diversity and structure along latitudinal gradients at different temperatures. We primarily sampled more high-quality single nucleotide polymorphisms (SNPs) from populations at lower and middle latitudes. Greater intraspecific genetic variation at each level of temperature treatment could be due to factors such as wind pollination and asexual breeding. Populations of C. dactylon at high latitudes differed from populations at middle and low latitudes, which was supported by a principal component analysis (PCA) and genetic structure analysis, performed at different temperatures. We observed more genetic variation for low-latitude populations at 5 °C, according to an analysis of three phylogenetic trees at different temperature levels, suggesting that low temperatures affected samples with low cold resistance. Based on the results of phylogenetic analysis, we found that samples from high latitudes evolved earlier than most samples at low latitudes. The results provide a comprehensive understanding of the evolutionary phenomenon of landscape genetics, laying the groundwork for future structural and comparative genomic studies of C. dactylon.

Primary pulmonary malignant melanoma diagnosed with percutaneous biopsy tissue: A case report.

BACKGROUND: Primary malignant melanoma of the lung (PMML) is a rare and highly malignant tumor with a poor prognosis. Here, we report a PMML case diagnosed by computed tomography (CT)-guided percutaneous biopsy, describe its pathological features and review relevant literature to improve our understanding of this tumor. CASE SUMMARY: A 64-year-old Chinese female presented with productive cough for 7 mo. A chest CT scan showed a large and space-occupying lesion in Lingual lobe. Positron emission tomography-CT revealed multiple nodules located in the superior lobe apicoposterior segment of her left lung. Brain magnetic resonance imaging showed numerous enhancing nodules, suggesting brain metastasis. Abdominal CT scan did not show any abnormalities. By CT-guided percutaneous biopsy, four pieces of gray and taupe tissues (1 cm length and 0.1 mm in diameter) were obtained. After pathologic examination, the tumor was found to consist of epidermal and nested small round cells, fibrosis and thin-walled blood vessels. The finding was suggestive of malignant melanoma. To confirm the diagnosis, pathological morphology and immunophenotypic features of the biopsy specimens were observed. The patient denied any history of skin tumors. No abnormal lesions were detected in other sites of the body. Molecular testing was positive for wild-type EGFR and KIT gene mutations. Finally, the clinical and pathological findings suggested PMML. CONCLUSION: PMML is very rare, and the percutaneous biopsy tissue is limited. Therefore, comprehensive consideration of histology, immunohistochemistry, imaging, and clinical information is important for the diagnosis of PMML.

Prevalence and Morphology of Mandibular Incisive Canal: Comparison among Healthy, Periodontitis and Edentulous Mandibles in a Population of the Beijing Area Using Cone-beam Computed Tomography.

OBJECTIVE: To evaluate and quantify the prevalence and morphology of the mandibular incisive canal (MIC) comparatively among healthy, periodontitis and edentulous mandibles using cone-beam computed tomography (CBCT). METHODS: CBCT images of 1,070 hemimandibles from 535 consecutive patients, including 448 with healthy dentition, 42 with severe periodontitis mandibles and 45 with edentulous mandibles, were retrospectively analysed. MICs were identified, and linear measurements were performed. Statistical analyses were conducted to investigate differences in the prevalence and morphology of MICs relative to gender, laterality, age group and dental status. RESULTS: The MIC was observed in 92.8% of 1,070 hemimandibles. No significant differences of MIC prevalence were found between left and right sides, or between healthy and periodontitis mandibles. However, males had a higher prevalence of MIC than females, and patients with dentate mandibles had a higher prevalence of MIC than those with edentulous mandibles. For dentate mandibles, MICs started most commonly below the first premolar (51.9%) and ended around the canine (58.5%). The mean diameter of MIC was 2.5 ± 0.5 mm at origin, and 20.6% of MICs began with a diameter of ≥ 3 mm. The mean length of MIC was 13.4 ± 3.3 mm. The mean distances from the MIC to the labial cortex, lingual cortex, alveolar ridge and inferior border of mandible were 3.7 ± 0.9, 5.1 ± 1.6, 19.5 ± 3.8 and 8.9 ± 1.7 mm, respectively. Moreover, significant differences of measurements were found relative to gender, age group, and dental status. CONCLUSION: Due to the large variations in size and course of MICs, special caution should be exercised in any individual surgery affecting the anterior mandible.

KLB gene polymorphism is associated with obesity and non-alcoholic fatty liver disease in the Han Chinese.

Klotho beta (KLB) mediates binding of fibroblast growth factor (FGF) 21 to the FGF receptor (FGFR). FGF21-KLB-FGFR signaling regulates multiple metabolic systems in the liver, and we hypothesized that FGF21, KLB and FGFR single-nucleotide polymorphisms (SNPs) are involved in hepatic lipid accumulation. The SNPs were detected in 1688 individuals divided into four groups: non-obese without non-alcoholic fatty liver disease (NAFLD), obese without NAFLD, non-obese with NAFLD, and obese with NAFLD. The A-allele of KLB SNP rs7670903 correlated with higher body mass index (P = 0.0005), and the A-allele frequency was higher in the obese than non-obese group (P = 0.003). The G-allele frequency of KLB rs7674434 and T-allele frequency of rs12152703 were higher in the obese with NAFLD than obese without NAFLD group (P = 0.004 and P = 0.006), but the genotype distribution between two non-obese groups did not differ. KLB rs7674434 and rs12152703 had associations with alanine aminotransferase (ALT) (P = 0.03 and P = 0.04, respectively) and gamma-glutamyltransferase (P = 0.03 and P = 0.02, respectively) levels in all subjects, but the associations were especially strong with ALT in the NAFLD group (P = 0.005 and P = 0.008, respectively). These findings suggest that KLB SNPs are related to obesity and hepatic inflammation and that they may be involved in the pathogenesis of NAFLD.

Morphologic Analysis of Maxillary Sinus Floor and its Correlation to Molar Roots using Cone Beam Computed Tomography.

OBJECTIVE: To analyse the anterior extension of the maxillary sinus, distribution of the sinus septa and vertical relationship between the maxillary sinus and molar roots using cone beam computed tomography (CBCT). METHODS: Imaging data of 970 consecutive patients who underwent CBCT scans were retrospectively collected. The anterior border, septa distribution of the maxillary sinus and relationship between the maxillary sinus and molar roots were analysed. The root-sinus relationship was divided into three types; the roots protruding into the sinus or touching the floor without a bony barrier was defined as Type I root-sinus relationship. RESULTS: Overall, 15.5% of the maxillary sinuses extended beyond the incisor region and 68.9% extended beyond the canine region. A bony septum of ≥ 2 mm was detected in 16.9% (328/1940) of the maxillary sinuses from 26.0% (252/970) of the patients. Among the 355 septa in the 328 sinuses with septa, 108 (30.4%) were located at the first and second premolar region, 180 (50.7%) at the first and second molar region and 67 (18.9%) posterior to the second molar. Among the first molars, a Type I root-sinus relationship was detected in 61.0% of palatine roots, 55.4% of distobuccal (DB) roots, and 52.7% of mesiobuccal (MB) roots. Moreover, among three-rooted second molars, a Type I relationship was detected in 62.0%, 58.2% and 45.8% of MB, DB and palatine roots, respectively. CONCLUSION: The maxillary sinus can extend beyond the incisor region; approximately 1/6 of sinuses have bony septa; and 1/2 of molar roots protrude into the maxillary sinus or touch the sinus floor without a bony barrier.

Stromal Expression of Vimentin Predicts the Clinical Outcome of Stage II Colorectal Cancer for High-Risk Patients.

BACKGROUND Increased expression of vimentin in tissue samples from patients with colorectal cancer (CRC) has been previously demonstrated, but its prognostic significance remains controversial, and the clinical significance for patients with stage II CRC is still unknown. The aim of this study was to evaluate the expression of vimentin in CRC and its potential prognostic significance. MATERIAL AND METHODS We analyzed vimentin expression in 203 CRC tissue samples from patients with stage II cancer using immunohistochemistry, and correlated the findings with clinicopathological patient features. CRC-specific survival (CSS) and disease-free survival (DFS) were analyzed using the Kaplan-Meier method. Univariate and multivariate analysis was performed using the Cox proportional hazards method for survival. RESULTS Vimentin expression was significantly correlated only with tumor (T) stage (p=0.024). Kaplan-Meier survival analysis indicated that vimentin expression could stratify the CSS and DFS of patients with stage II CRC at high risk (p=0.029, p=0.042, respectively), but not those of low-risk stage II patients (p=0.208, p=0.361, respectively). Univariate and multivariate analysis further revealed that stromal vimentin expression is an independent prognostic factor for CSS and DFS of high-risk stage II patients (p=0.043, p=0.022, respectively). Moreover, high-risk stage II patients with low stromal vimentin expression benefitted more from standard adjuvant chemotherapy than those with high stromal vimentin expression (CSS: p=0.012 vs. p=0.407; DFS: p=0.017 vs. p=0.420). CONCLUSIONS Our study suggests that stromal vimentin expression is a promising indicator for survival prediction and adjuvant chemotherapy response in patients with stage II CRC with high-risk factors for recurrence.

Anorectal functional outcome following laparoscopic low anterior resection for rectal cancer.

Low anterior resection (LAR) with total mesorectal excision has been considered a standard treatment for patients with rectal cancer. However, the functional outcome and life quality of laparoscopic LAR (LLAR) in Chinese patients remain unclear. A cohort of 51 Chinese patients (22 men and 29 women) who had undergone LLAR was included in this study. Anorectal manometry combined with the Wexner scores questionnaire were applied to assess functional outcome preoperatively (1 week) and postoperatively (at 3, 6 and 9 months). The validated Chinese versions of the European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-CR38 questionnaires were also used to assess the patients' quality of life at the indicated time points. The results demonstrated that the manometric parameters exhibited a temporary decrease at 3 months postoperatively, but a gradual increase at 6 and 9 months, while the Wexner scores exhibited an opposite trend. Furthermore, patients with high anastomoses had significantly higher manometric parameters, a lower frequency of incontinence and lower Wexner scores compared with those with low anastomoses at 9 months (all P<0.05). For the entire cohort, quality of life at 3 months postoperatively was worse compared with the preoperative level, but returned to normal by 9 months. Patients with high anastomoses exhibited significantly better role, emotional and social function, had a better body image and sexual function, fewer problems with defecation and lower frequency of diarrhea, as well as fewer chemotherapy-related side effects at 6 months postoperatively when compared with the low anastomosis group (all P<0.05). In conclusion, LLAR is generally acceptable for Chinese patients with rectal cancer, particularly for those with middle or high rectal cancer, in terms of functional outcome and quality of life.

Overexpression of Tbx3 is correlated with Epithelial-Mesenchymal Transition phenotype and predicts poor prognosis of colorectal cancer.

AIMS: To investigate the clinical significance of Tbx3 in colorectal cancer (CRC) and the possible association between Tbx3 expression and Epithelial- Transition Mesenchymal (EMT) phenotype. METHODS: Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) and western blotting were employed to evaluate the expression of Tbx3 in 30 fresh CRC and matched normal tissues. Using immunochemistry, protein level of Tbx3 and EMT markers (E-cadherin and N-cadherin) were identified in 150 pairs of paraffin-embedded specimen. RESULTS: The results of qRT-PCR and western blotting showed that Tbx3 expression was higher in CRC tissues than in corresponding normal tissues. The statistical analysis based on immunohistochemical evaluation suggested that Tbx3 aberrant expression was significantly associated with tumor size (P=0.049), differentiation (P=0.032), invasion (P=0.019), lymph node metastasis (P=0.049) and TNM stage (P=0.018). Patients who displayed high expression of Tbx3 may achieve a poorer overall survival (OS) and disease-free survival (DFS), compared to those with low expression of Tbx3. This tendency was also observed in patients with intermediate levels of disease (II and III stage). The multivariate analysis indicated Tbx3 expression could independently predict the outcome of CRC patients. Interestingly, correlation analysis suggested Tbx3 expression was negatively correlated with E-cadherin expression, but positively correlated with N-cadherin expression. CONCLUSION: Tbx3 may promote CRC progression by involving EMT program and has the potential to be an effective prognostic predictor for CRC patients.

Levels of interleukin-35 and its relationship with regulatory T-cells in chronic hepatitis B patients.

Interleukin-35 is a novel inhibition cytokine secreted by CD4+CD25+ regulatory T-cells (Treg) in murine. However, it is disputed whether IL-35 could be secreted by Treg cells in humans. In this study, the levels of IL-35 were detected, and its relationship with regulatory T-cells in chronic hepatitis B (CHB) patients was investigated. It was shown that the levels of IL-35 in CHB patients were higher than those in normal controls, and the levels increased gradually, accompanied with the severe liver inflammation and necrosis and poor synthesis function. Treg cells may secrete IL-35, whose levels would become higher, accompanied by a longer activated time. Thus, IL-35 as a cytokine secreted by Treg cells may accelerate liver inflammation and necrosis, and inhibit the synthesis function.

Knockdown of Y­box­binding protein­1 inhibits the malignant progression of HT­29 colorectal adenocarcinoma cells by reversing epithelial­mesenchymal transition.

Y­box binding protein­1 (YB­1) has been identified as an oncoprotein in various malignancies. The aim of this study was to investigate the biological role of YB­1 and its association with epithelial­to­mesenchymal transition (EMT) in colorectal cancer (CRC). The expression of YB­1 and three EMT­related proteins (E­cadherin, N­cadherin and vimentin) was analyzed in 80 CRC and matched normal tissue samples, by immunohistochemistry. The results indicated that the expression of YB­1 was higher in CRC tissue samples than that in matched normal controls and was significantly correlated with tumor differentiation, tumor invasion, lymph node metastasis and distant metastases. Furthermore, analysis showed that YB­1 expression was negatively correlated with E­cadherin and positively correlated with N­cadherin and vimentin expression. In vitro assays showed that knockdown of YB­1 inhibited the proliferation, apoptosis resistance, invasion and migration of the HT­29 CRC cell line. Of note, following knockdown of YB­1, E­cadherin expression was elevated whereas N­cadherin and vimentin expression was reduced. Taken together, these results suggest that YB­1 promotes the malignant progression of CRC in part through the induction of EMT, and YB­1 may therefore be a potential novel target for CRC treatment.

Evaluation of dental root fracture using cone-beam computed tomography.

OBJECTIVE: To evaluate the application of cone-beam computed tomography (CBCT) in the detection of dental root fractures and to analyse the demographic profile of these fractures. METHODS: The study group comprised 398 teeth that were examined by CBCT for determining whether they had a root fracture. Patient characteristics were recorded, and the location, fractured roots, fracture types and three-dimensional images of the related skeletal structures were analysed. Two experienced oral radiologists independently analysed each case and reached a consensus, and the diagnosis was graded in one of the following three categories: fracture definitely present (FDP), fracture probably present (FPP) and no visible fracture (NVF). RESULTS: Among these teeth, 155 (39.0%) were diagnosed as FDP, 14 (3.5%) as FPP and 229 (57.5%) as NVF in the consensus reading. During follow-up, all teeth diagnosed as FDP and 4 of the 14 teeth diagnosed as FPP were intra-operatively demonstrated to be fractured. In FDP cases, 60.0% of the patients were aged from 50 to 69 years. In total, 107 FDP teeth were non-endodontically treated, and the remaining were endodontically treated with (n = 16) or without (n = 32) crown placement. The maxillary and mandibular molars were most frequently affected (81.9%). The fractured roots were mostly palatal (65.7%) in maxillary molars and mesial (84.2%) in mandibular molars. The fractures were characterised as vertical (n = 84), horizontal (n = 34), oblique (n = 5) and complicated (n = 32) fractures. CONCLUSION: The application of CBCT is valuable for the diagnosis of root fracture.

Associations among Genotype 1b Hepatitis C Virus Core Protein, Protein Kinase R, and Signal Transducer and Activator of Transcription 3.

BACKGROUND AND AIMS: Because hepatitis C virus (HCV) core protein (Core), protein kinase R (PKR), and signal transducer and activator of transcription 3 (STAT3) all play relevant roles in the pathogenesis of HCV, persistent infection and hepatocellular carcinoma (HCC) and PKR may interact with HCV Core. In this study, we further investigate the associations among HCV Core, PKR, and STAT3 and the mechanisms involved in these interactions. MATERIALS AND METHODS: Expression levels of HCV Core, PKR, eukaryotic initiation factor 2 (eIF-2α), phosphorylated eIF- 2α (p-eIF-2α), STAT3, and phosphorylated-STAT3 (p-STAT3) were compared between Huh-7 and replicon cell-Huh-7 cells harboring the full length of genotype 1b HCV genomes. Co-immunoprecipitation and glutathione S-transferase (GST) pull-down assay were conducted for HCV Core, PKR, and STAT3. RESULTS: HCV may have induced the expression of STAT3 and the activity of PKR (p-eIF-2α). HCV Core, STAT3, and PKR appear to have interacted with one another. The N-terminal 1-126 amino acid (aa) of HCV Core contributed to an interaction between HCV Core and STAT3, and only full-length PKR bound to STAT3 and p-STAT3. CONCLUSIONS: These findings suggest that HCV Core, PKR, and STAT3 can interact with each other. Specifically, HCV Core may play its role through both PKR and STAT3. Alternatively, HCV Core's binding to and activation of STAT3 might be due to the interaction between HCV Core and PKR. The distinct interactions among these three molecules are important and may reveal a new molecular mechanism in the pathogenesis of HCV-persistent infection and HCV-related HCC.

[Experimental study on bond strength of machinable composite resin and dentin with three kinds of resin cements].

OBJECTIVE: To examine the shear and microtensile bond strength between a newly developed dental machinable composite resin (polymethylmetacrylate/nano SiO2-ZrO2, PNSZ) and dentin cemented using three resin luting systems and to select the most suitable one. METHODS: The shear and microtensile bond strength between the machinable composite resin and dentin cemented using three resin luting systems (Group A:RelyX ARC, Group B:Panavia-F,Group C:Variolink II) were tested. The broken specimens were observed with a stereomicroscope (x 50) to compare their failure modes. RESULTS; In the shear tests, no significant difference was found in bond strength among Group A [ (14. 07 +/- 4. 67) MPa] ,Group B[ (13.17 +/- 4. 63) MPa] and Group C [ ( 12. 10 +/- 2.18) MPa] (P > 0.05) . In the microtensile tests, no significant difference was found in bond strength among Group A [(11.49 +/- 4.90) MPa],Group B[(9.66 +/- 4.15) MPa].and Group C[(10.11 +/- 4.20) MPa](P > 0. 05).The failure modes of all the three resin cements were predominantly adhesive failures at the dentin/cement interface. CONCLUSIONS: The three types of resin cements showed similar results in bond strength between the dental machinable composite resin and dentin. Bonding at the resin/cement interface was stronger than that at the dentin/cement interface.

Hepatitis C virus core proteins derived from different quasispecies of genotype 1b inhibit the growth of Chang liver cells.

AIM: To investigate the influence of different quasispecies of hepatitis C virus (HCV) genotype 1b core protein on growth of Chang liver cells. METHODS: Three eukaryotic expression plasmids (pEGFP-N1/core) that contained different quasispecies truncated core proteins of HCV genotype 1b were constructed. These were derived from tumor (T) and non-tumor (NT) tissues of a patient infected with HCV and C191 (HCV-J6). The core protein expression plasmids were transiently transfected into Chang liver cells. At different times, the cell cycle and apoptosis was assayed by flow cytometry, and cell proliferation was assayed by methyl thiazolyl tetrazolium (MTT) assay. RESULTS: The proportion of S-phase Chang liver cells transfected with pEGFP-N1/core was significantly lower than that of cells transfected with blank plasmid at three different times after transfection (all P < 0.05). The proliferation ratio of cells transfected with pEGFP-N1/core was significantly lower than that of cells transfected with blank plasmid. Among three different quasispecies, T, NT and C191 core expression cells, there was no significant difference in the proportion of S- and G0/G1-phase cells. The percentage of apoptotic cells was highest for T (T > NT > C191), and apoptosis was increased in cells transfected with pEGFP-N1/core as the transfection time increased (72 h > 48 h > 24 h). CONCLUSION: These results suggest that HCV genotype 1b core protein induces apoptosis, and inhibits cell-cycle progression and proliferation of Chang liver cells. Different quasispecies core proteins of HCV genotype 1b might have some differences in the pathogenesis of HCV persistent infection and hepatocellular carcinoma.

Mapping of the interacting domains of hepatitis C virus core protein and the double-stranded RNA-activated protein kinase PKR.

Hepatitis C virus (HCV) core protein has been shown to exhibit several biological properties which suggest an important role in liver pathogenesis and carcinogenesis. During a previous study, we showed that core mutants, isolated from tumour, could directly interact with PKR and maintain it in an activated form. In the present report, we have further investigated this interaction and mapped the core and PKR domains involved. Using glutathion S-transferase fusion protein harbouring the different domains of core or PKR, we determined that the N-terminal 1-58 amino acid (aa) of core protein and the N-terminal 1-180 aa of PKR are responsible for this direct interaction. Using this system we also confirmed that the core-PKR interaction induced PKR autophosphorylation. Furthermore, we found that core protein co-localized and co-immunoprecipitated with PKR in cells expressing a full-length HCV replicon, thus confirming that this interaction occurs when all HCV proteins are expressed. Considering that the activation of PKR has been observed in some cancer cell lines and tissues, it suggests that, depending on the cellular context, PKR may stimulate or inhibit cell proliferation. The precise mapping of core-PKR interaction provides new data to study the molecular mechanism underlying HCV pathogenesis.

Proapoptotic and pronecrosis effect of different truncated hepatitis C virus core proteins.

OBJECTIVE: To study the roles of different truncated hepatitis C virus (HCV) core proteins (CORE) in the pathogenesis of HCV persistent infection and hepatocellular carcinoma (HCC) and to assess intracellular localization in transiently transfected cells. METHODS: Seven truncated GFP (green fluorescent protein)-CORE fusion protein expression plasmids were constructed, which contained HCV CORE sequences derived from tumor tissues (BT) and non-tumor tissues (BNT) from one patient infected with HCV. Amino acid (aa) lengths were BT: 1-172 aa, 1-126 aa, 1-58 aa, 59-126 aa, 127-172 aa; BNT: 1-172 aa and C191: 1-172 aa respectively. Subcellular localization of CORE-GFP was analyzed by con-focal laser scanning microscope. Apoptosis and necrosis were quantified by flow cytometry. RESULTS: Different truncated CORE-GFP localized mainly in the cytoplasm, but nuclear staining was also observed. HCV CORE could induce apoptosis and necrosis, and different truncated COREs could induce cell apoptosis and necrosis at different levels. Among the same length 1-172 aa of BT, BNT and C191, the cell apoptosis and necrosis percentage of BT is highest, and C191 is the lowest (BT>BNT>C191). To the different fragment COREs of BT, N-terminal of CORE induced apoptosis and necrosis higher, compared with that of C-terminal (1-172 aa>1-126 aa>1-58 aa>127-172 aa>59-126 aa). CONCLUSION: These results suggest HCV CORE could induce apoptosis and necrosis of cells, which might play an important role in the pathogenesis of HCV persistent infection and HCC and the different CORE domains of different HCV quasi-species might have some difference in their pathogenesis.

[Construction and expression of plasmids containing different truncated core proteins of hepatitis C virus derived from tumor and non-tumor tissues].

OBJECTIVE: To study the role of different truncated core proteins (CORE) of hepatitis C virus (HCV) played in the pathogenesis of HCV persistent infection and hepatocellular carcinoma, and to construct seven different truncated prokaryotic expression plasmids of HCV CORE. METHODS: The gene sequences of different truncated HCV genotype 1b CORE were amplified from plasmids containing CORE sequences derived from tumor and non-tumor tissues of a patient infected with HCV. Amino acid (aa) lengths of HCV BT (from tumor tissue, patient B) were: 1-172 aa, 1-126 aa, 1-58 aa, 59-126 aa, 127-172 aa; of BNT (non-tumor tissue, patient B) were: 1-172 aa and HCV C191 (HCV-J6): 1-172 aa. PCR products were cleaved with restriction enzymes BamH I and EcoR I and cloned into pGEX-4T-1. Positive clones were transformed into BL21 and glutathione S-transferase(GST)-CORE fusion proteins were expressed with isopropylthio-beta-D-galactoside (IPTG) induction, purified and verified by Western blot. RESULTS: Different truncated GST-CORE fusion proteins were expressed with different quantities. Except the fragment of 59-126 aa, the longer the fragment, the less its expression. The levels of truncated expression of CORE of BT and BNT were higher than that of C191, even though they all contained 1-172 aa. Some of truncated CORE of HCV genotype 1b could form dimmers. CONCLUSIONS: Successful construction of truncated GST-CORE expression plasmids lays a basis for future study of the function of different domains of CORE of different HCV strains; different expression levels of HCV COREs might be related to their different hydrophobicity, cytotoxicity and their functions in HCV structure and their roles played in the pathogenesis; the domain of 59-126 aa is responsible for the HCV genotype 1b CORE dimmer formation.