RARRES1 inhibits hepatocellular carcinoma progression and increases its sensitivity to lenvatinib through interaction with SPINK2.

BACKGROUND: Lenvatinib is an oral small molecule inhibitor approved for treating patients with unresectable hepatocellular carcinoma (HCC) worldwide. Increasing cell sensitivity to lenvatinib would be an effective method of improving therapeutic efficacy. METHODS: High throughput methods was used to scan the differentially expressed genes (DEGs) related to lenvatinib sensitivity in HCC cells. Gain- and loss-function experiments were used to explore the functions of these DEGs in HCC and lenvatinib sensitivity. CO-IP assay and rescue experiments were utilized to investigate the mechanism. RESULTS: We identified that RAR responder protein 1 (RARRES1), a podocyte-specific growth arrest gene, was among significantly upregulated DEGs in HCC cells following lenvatinib treatment. Functional analysis showed that ectopic RARRES1 expression decreased HCC progression in vitro and in vivo, as well as improving tumor sensitivity to lenvatinib, while RARRES1 silencing increased HCC cell proliferation and migration. Mechanistically, co-immunoprecipitation assays demonstrated that RARRES1 interacted with serine protease inhibitor Kazal-type 2 (SPINK2) in HCC cells. Further, SPINK2 overexpression suppressed HCC cell proliferation and migration, as well as increasing sensitivity to lenvatinib whereas SPINK2 knockdown promoted cell progression and decreased lenvatinib sensitivity. The mRNA and protein levels of RARRES1 and SPINK2 were low in HCC tissue samples, relative to those in normal liver tissue. CONCLUSIONS: Our findings highlighted that RARRES1 can inhibit HCC progression and regulate HCC sensitivity to lenvatinib by interacting SPINK2, representing a new tumor suppressor RARRES1/SPINK2 axis in HCC that modulates sensitivity to lenvatinib.

ETV7 promotes colorectal cancer progression through upregulation of IFIT3.

Members of the E26 transformation-specific (ETS) variant transcription factor family act as either tumor suppressors or oncogenic factors in numerous types of cancer. ETS variant transcription factor 7 (ETV7) participates in the development of malignant tumors, whereas its involvement in colorectal cancer (CRC) is less clear. In this study, The Cancer Genome Atlas (TCGA) and immunochemistry staining were applied to check the clinical relevance of ETV7 and interferon-induced protein with tetratricopeptide repeats 3 (IFIT3) in CRC patients. Overexpression and knockdown of ETV7 and IFIT3 were conducted by transfecting the cells with pCDNA3.1 plasmids and siRNAs, respectively. Western blotting was used to detect the protein expression of ETV7 in CRC cells. Cell Counting Kit-8, cell colony formation, and Transwell assays, as well as flow cytometry, were used to evaluate the proliferation, migration, cell cycle, and apoptosis of CRC cells. Furthermore, western blotting, RT-qPCR, and luciferase assay were used to explore the regulation of ETV7 on IFIT3. Rescue assay was used to investigate the significance of ETV7/IFIT3 axis on CRC progression. We found that ETV7 was upregulated in CRC tissues and cells. Overexpression of ETV7 stimulated the proliferation, migration, and cell cycle amplification, and reduced the apoptosis of CRC cells. Downregulation of ETV7 exerted the opposite effect on CRC cell progression. Moreover, we demonstrated that ETV7 stimulated the transcription activity, the mRNA and protein expression of IFIT3 in CRC cells. There was a positive correlation between ETV7 and IFIT3 in CRC patients. IFIT3 knockdown reversed the promotive effect exerted by overexpression of ETV7 on the amplification and migration of CRC cells. By contrast, overexpression of IFIT3 blocked the inhibitory effect of ETV7-targeting siRNA. In summary, ETV7 induces progression of CRC by activating the transcriptional expression of IFIT3. The EVT7/IFIT3 axis may be a novel target for CRC therapy.

Evidence for the Clinical Association between Demodex and Rosacea: A Review.

BACKGROUND: Rosacea is a chronic inflammatory dermatological condition in humans, and its pathogenesis remains unclear. However, the development of rosacea is suspected to be related to Demodex, a microscopic commensal organism that resides in or near hair follicles and sebaceous glands. Although Demodex is known to be a host-specific, obligate commensal organism, it is currently difficult to be cultured in vitro to parasitize and infect other animal hosts. Therefore, direct evidence for a pathogenic role of Demodex in rosacea is currently lacking. SUMMARY: As circumstantial evidence, non-invasive skin-detecting techniques have shown abnormally elevated numbers of Demodex in rosacea patients. Increased cytokine levels such as IL-10, IL-8, and IL-12p70 have been observed in human sebocytes following the Demodex challenge, and acaricides have been found to be effective in rosacea therapy, all point to a close relationship between Demodex and rosacea. Based on these findings, we conducted a comprehensive literature review to summarize the current state of knowledge, research insights, and clinical treatment recommendations for Demodex-associated rosacea, with the ultimate goal of improving patient outcomes.

Krüppel-like factor 4 (KLF4) facilitates lipid production in immortalized human sebocytes via regulating the expression of SREBP1.

BACKGROUND: Acne is associated with the excessive production of sebum, a complex mixture of lipids, in the sebaceous glands. The transcription factor Krüppel-like factor 4 (KLF4) plays an important role in skin morphogenesis, but its role in sebum production by sebocytes is not well known. PURPOSE: In this study, we investigated the possible action mechanism of KLF4 during calcium-induced lipogenesis in immortalized human sebocytes. METHODS: Sebocytes were treated with calcium, and lipid production was confirmed by thin-layer chromatography (TLC) and Oil Red O staining. To investigate the effect of KLF4, sebocytes were transduced with the KLF4-overexpressing adenovirus, and then lipid production was evaluated. RESULTS: Calcium treatment resulted in increased sebum production in terms of squalene synthesis in sebocytes. In addition, calcium increased the expression of lipogenic regulators such as sterol-regulatory element binding protein 1 (SREBP1), sterol-regulatory element binding protein 2 (SREBP2), and stearoyl-CoA desaturase (SCD). Similarly, the expression of KLF4 was increased by calcium in sebocytes. To investigate the effect of KLF4, we overexpressed KLF4 in sebocytes using recombinant adenovirus. As a result, KLF4 overexpression increased the expression of SREBP1, SREBP2, and SCD. Parallel to this result, lipid production was also increased by KLF4 overexpression. Chromatin immunoprecipitation revealed the binding of KLF4 to the SREBP1 promoter, indicating that KLF4 may directly regulate the expression of lipogenic regulators. CONCLUSION: These results suggest that KLF4 is a novel regulator of lipid production in sebocytes.

In Vitro Inhibition of Growth, Biofilm Formation, and Persisters of Staphylococcus aureus by Pinaverium Bromide.

Biofilm or persister cells formed by Staphylococcus aureus are closely related to pathogenicity. However, no antimicrobials exist to inhibit biofilm formation or persister cells induced by S. aureus in clinical practice. This study found that pinaverium bromide had antibacterial activity against S. aureus, with the MIC50/MIC90 at 12.5/25 µM, respectively. Pinaverium bromide (at 4 × MIC) showed a rapid bactericidal effect on S. aureus planktonic cells, and it was more effective (at least 1-log10 cfu/mL) than linezolid, vancomycin, and ampicillin at 4 h of the time-killing test. Pinaverium bromide (at 10 × MIC) significantly inhibited the formation of S. aureus persister cells (at least 3-log10 cfu/mL) than linezolid, vancomycin, and ampicillin at 24, 48, 72, 96, and 120 h of the time-killing test. Biofilm formation and adherent cells of S. aureus isolates were significantly inhibited by pinaverium bromide (at 1/2 or 1/4 × MICs). The fluorescence intensity of the membrane polarity of S. aureus increased with the treatment of pinaverium bromide (≥1 × MIC), and the MICs of pinaverium bromide increased by 4 times with the addition of cell membrane phospholipids, phosphatidyl glycerol and cardiolipin. The cell viabilities of human hepatocellular carcinoma cells HepG2 and Huh7, mouse monocyte-macrophage cells J774, and human hepatic stellate cells LX-2 were slightly inhibited by pinaverium bromide (<50 µM). There were 54 different abundance proteins detected in the pinaverium bromide-treated S. aureus isolate by proteomics analysis, of which 33 proteins increased, whereas 21 proteins decreased. The abundance of superoxide dismutase sodM and ica locus proteins icaA and icaB decreased. While the abundance of global transcriptional regulator spxA and Gamma-hemolysin component B increased. In conclusion, pinaverium bromide had an antibacterial effect on S. aureus and significantly inhibited the formation of biofilm and persister cells of S. aureus.

Pleckstrin 2 is a potential drug target for colorectal carcinoma with activation of APC/ß­catenin.

The tumor suppressor gene adenomatous polyposis coli (APC) is frequently inactivated or absent in colorectal carcinoma (CRC). Loss­of­function of APC promotes the expression of ß­catenin, which is critical for CRC development. Since ß­catenin acts as an important transcription factor, blockage of ß­catenin may have side effects, including impairment of tissue homeostasis and regeneration, thus limiting the application of ß­catenin inhibitors for the treatment of patients with CRC. Therefore, identifying a novel substrate of APC/ß­catenin may provide essential clues to develop effective drugs. Small interfering RNA technology and lentivirus­mediated overexpression were performed for knockdown and overexpression of pleckstrin 2 (PLEK2) in CRC cells. Cell Counting Kit­8 and colony formation assays, and cell cycle analysis and cell apoptosis detection were used to detect the capacity of cell proliferation, cell cycle distribution and apoptosis. The present study demonstrated that the APC/ß­catenin signaling cascade transcriptionally activated PLEK2 in CRC cells. PLEK2 expression was markedly increased in CRC tissues. There was an inverse correlation between APC and PLEK2 expression in patients with CRC. In vitro, overexpression of PLEK2 increased the proliferation of CRC cells. Opposite results were observed in the cells with knockdown of PLEK2. Furthermore, PLEK2 promoted cell cycle progression and suppressed apoptosis. In summary, upregulation of PLEK2 contributed to CRC proliferation and colony formation activated by the APC/ß­catenin signal pathway. Targeting PLEK2 may be important for the treatment of patients with CRC with activation of the APC/ß­catenin signaling pathway.

KLF7/VPS35 axis contributes to hepatocellular carcinoma progression through CCDC85C-activated ß-catenin pathway.

OBJECTIVE: Dysregulation of KLF7 participates in the development of various cancers, but it is unclear whether there is a link between HCC and aberrant expression of KLF7. The aim of this study was to investigate the role of KLF7 in proliferation and migration of hepatocellular carcinoma (HCC) cells. METHODS: CCK8, colony growth, transwell, cell cycle analysis and apoptosis detection were performed to explore the effect of KLF7, VPS35 and Ccdc85c on cell function in vitro. Xenografted tumor growth was used to assess in vivo role of KLF7. Chip-qPCR and luciferase reporter assays were applied to check whether KLF7 regulated VPS35 at transcriptional manner. Co-IP assay was performed to detect the interaction between VPS35 and Ccdc85c. Immunohistochemical staining and qRT-PCR analysis were performed in human HCC sampels to study the clinical significance of KLF7, VPS35 and ß-catenin. RESULTS: Firstly, KLF7 was highly expressed in human HCC samples and correlated with patients' differentiation and metastasis status. KLF7 overexpression contributed to cell proliferation and invasion of HCC cells in vitro and in vivo. KLF7 transcriptional activation of VPS35 was necessary for HCC tumor growth and metastasis. Further, co-IP studies revealed that VPS35 could interact with Ccdc85c in HCC cells. Rescue assay confirmed that overexpression of VPS35 and knockdown of Ccdc85c abolished the VPS35-medicated promotion effect on cell proliferation and invasion. Finally, KLF7/VPS35 axis regulated Ccdc85c, which involved in activation of ß-catenin signaling pathway, confirmed using ß-catenin inhibitor, GK974. Functional studies suggested that downregulation of Ccdc85c partly reversed the capacity of cell proliferation and invasion in HCC cells, which was regulated by VPS35 upregulation. Lastly, there was a positive correlation among KLF7, VPS35 and active-ß-catenin in human HCC patients. CONCLUSION: We demonstrated that KLF7/VPS35 axis promoted HCC cell progression by activating Ccdc85c-medicated ß-catenin pathway. Targeting this signal axis might be a potential treatment strategy for HCC.

Discoid lupus erythematosus solely involving the eyelids: case report and literature review.

BACKGROUND AND OBJECTIVE: The involvement of eyelids occurs in only 5-6% of patients with discoid lupus erythematosus (DLE), commonly with mucocutaneous lesions elsewhere. DLE solely involving the eyelids is relatively rare. This study aimed to describe the clinical features and treatments of all the reported cases of DLE with eyelid involvement as the only symptom. METHODS: A systematic review was done of all the related literature published both in English and Chinese from May 1, 1984, to March 1, 2020. Only those cases of DLE solely involving eyelids were selected and summarized in two tables. RESULTS: (i) DLE solely involving the eyelids is five times more likely to affect females than males. (ii) The majority of cases were presenting with unilateral eyelid involvement. Lower lids, especially both lower lids, were the most commonly affected locations. (iii) An erythematous plaque with scales is the most frequent manifestation. (iv) Approximately 22.9% of the cases had a positive antinuclear antibody (ANA) titer, and the speckled pattern was the most seen. For direct immunofluorescence (DIF), 94.4% of the performed cases showed positive results. (v) More than 85% of these cases showed an excellent response to treatment with oral antimalarials. CONCLUSION: Awareness of this atypical presentation is important to avoid underdiagnosis of DLE solely involving the eyelids. A biopsy for both routine histology and DIF is critical for establishing the diagnosis.

MiR-32-5p aggravates intestinal epithelial cell injury in pediatric enteritis induced by Helicobacter pylori.

BACKGROUND: Pediatric enteritis is one of the infectious diseases in the digestive system that causes a variety of digestive problems, including diarrhea, vomiting, and bellyache in children. Clinically, Helicobacter pylori (H. pylori) infection is one of the common factors to cause pediatric enteritis. It has been demonstrated that aberrant expression of microRNAs (miRNAs) is found in gastrointestinal diseases caused by H. pylori, and we discovered a significant increase of miR-32-5p in H. pylori-related pediatric enteritis. However, the exact role of miR-32-5p in it is still unknown. AIM: To investigate the role of aberrant miR-32-5p in pediatric enteritis induced by H. pylori. METHODS: MiR-32-5p expression was detected by quantitative real time-polymerase chain reaction. The biological role of miR-32-5p in H. pylori-treated intestinal epithelial cells was evaluated by Cell Counting Kit-8 assay and flow cytometry. The potential target of miR-32-5p was predicted with TargetScanHuman and verified by luciferase assay. The downstream mechanism of miR-32-5p was explored by using molecular biology methods. RESULTS: We found that miR-32-5p was overexpressed in serum of H. pylori-induced pediatric enteritis. Further investigation revealed that H. pylori infection promoted the death of intestinal epithelial cells, and increased miR-32-5p expression. Moreover, miR-32-5p mimic further facilitated apoptosis and inflammatory cytokine secretion of intestinal epithelial cells. Further exploration revealed that SMAD family member 6 (SMAD6) was the direct target of miR-32-5p, and SMAD6 overexpression partially rescued cell damage induced by H. pylori. The following experiments showed that miR-32-5p/SMAD6 participated in the apoptosis of intestinal epithelial cells induced by transforming growth factor-ß-activated kinase 1 (TAK1)-p38 activation under H. pylori infection. CONCLUSION: Our work uncovered the crucial role of aberrant expression of miR-32-5p in H. pylori-related pediatric enteritis, and suggested that the TAK1-p38 pathway is involved in it.

MiR-223-3p promotes the proliferation, invasion and migration of colon cancer cells by negative regulating PRDM1.

Colon cancer is one of the most common malignancies worldwide, while the molecular mechanism remains largely unknown. miR-223-3p plays an important role in cancer development. Here, we found that miR-223-3p was up-regulated in 30 cases of colon cancer tissues as compared with their adjacent normal tissues. Lentivirus-mediated miR-223-3p over-expression promoted the proliferation, colony formation, migration and invasion of colon cancer cells. Inverse results were observed in miR-223-3p knockdown cells. Epithelial-mesenchymal transition (EMT) was regulated by miR-223-3p. In addition, cell apoptosis was suppressed and enhanced by miR-223-3p over-expression and knockdown, respectively. We further identified PRDM1, a tumor suppressor, was the target of miR-223-3p using microarray and luciferase assay. Our findings suggested that miR-223-3p acts as an oncogenic microRNA in colon cancer through regulating EMT and PRDM1.

[Distribution Pattern and Diversity Maintenance Mechanisms of Fungal Community in Subalpine Lakes].

The composition and diversity of fungal communities are essential to maintain the ecosystem balance of subalpine lakes. The aquatic fungal communities at different depths from the subalpine Pipahai (PPH, 0, 2, 4 m), Mayinghai (MYH, 0, 2, 4, 6 m), and Gonghai (GH, 0, 2, 4, 6, 8 m) lakes were studied. In addition to that, the distribution pattern and diversity maintenance mechanism (determination process vs. random process) of fungal communities were explored using high-throughput sequencing. The results showed that the physicochemical parameters of the water were significantly different among the three lakes. The pH, electrical conductivity (EC), ammonia nitrogen (NH4+-N), total carbon (TC), and inorganic carbon (IC) of GH were significantly higher than in the other two lakes. The fungal community was mainly composed of Ascomycota (0.82%-21.05%), Basidiomycota (1.26%-11.79%), Chytridiomycota (0.42%-4.26%), and Rozellomycota (0.11%-0.33%). Cystobasidiomycetes, Dothideomycetes, Chytridiomycetes, and Sordariomycetes were the dominant classes shared by the three lakes. The α-diversity index and the relative abundance of dominant classes were significantly different among the three lakes (P<0.05), but there were no significant differences between the various depths on each lake. The results of the ANOSIM analysis showed that the ß-diversity of the fungal communities were significantly different (r=0.99, P<0.01) among the lakes. There was also expressive differences at various depths on MYH (r=0.98, P<0.01) and GH (r=0.25, P<0.05), but no significant difference in PPH (r=0.23, P>0.05). The analysis results of redundancy and variation partitioning showed that the ß-diversity pattern of fungal communities in small region areas (among the three lakes) and local areas (different depths of MYH) were driven by environmental selection and dispersal limitation. However, the relative role of environmental selection was more significant, with water pH, dissolved oxygen (DO), TC, and EC being the main influencing factors. The results of the null model analysis showed that the interspecific interactions promoted the maintenance of the ß-diversity pattern of the fungal community in GH. In summary, the ß-diversity pattern of fungal communities in the subalpine lakes was mainly driven by a deterministic process.

The prognostic value of homeobox B7 expression in patients with hepatocellular carcinoma.

The prognostic role of homeobox B7 (HOXB7) in hepatocellular carcinoma (HCC) is not clearly established. The present study aimed to evaluate the associations among the clinicopathological characteristics, HOXB7 expression, and the overall survival (OS) of patients with HCC. An immunohistochemical analysis was used to detect the expression level of HOXB7. In addition, the association between the expression of HOXB7 and the clinicopathological characteristics of HCC was analyzed. The Kaplan-Meier method was used to calculate the survival rates, and the COX proportional hazards model was used to investigate univariate and multivariate analyses. A total of 80 patients were enrolled in this study. Of the 80 HCC samples, HOXB7 was up-regulated in 28 samples (35.0%). The high HOXB7 expression was significantly associated with OS by univariate Cox regression analysis (HR = 2.0; 95% CI = 1.1-3.4, P = 0.016). The median survival with high HOXB7 expression and low HOXB7 expression was 12.5 months ± 3.7 months versus 32.5 months ± 4.7 months, respectively, as visualized on Kaplan-Meier curves (P = 0.014). After adjusting for possible factors related to survival time after HCC resection, the results suggested that survival time was negatively correlated with high HOXB7 expression (HR = 2.592, 95% CI = 1.283-5.239, P = 0.008). The present data indicate that the HOXB7 expression was negatively associated with survival time after HCC resection. As HOXB7 was a common and readily available measurement in the clinical setting, it was a convenient and feasible way to identify those patients who were at high risk and who had a poor prognosis.

[Construction and significance of recombinant hF9 minigene and its stable nonsense mutant cell lines].

This study was purposed to construct the recombinant hF9 minigene and its stable nonsense mutant cell lines, and to investigate its significance. Minigene hF9 was cloned into the mammalian expression vector pCMV-Tag3B; a nonsense mutant containing a premature termination codon (PTC) in the 121(st) amino acid residue was obtained by PCR site-directed mutagenesis; minigene hF9 and nonsense mutant were respectively transfected into HepG2 cells with G418 treatment to get stable HepG2-WT and HepG2-N cell lines. The results confirmed that the minigene hF9 and nonsense mutant were constructed successfully. The gene of interest was amplified by RT-PCR from the stable cell lines, and the minigene hF9 was expressed in the stable cell lines. It is concluded that the recombinant hF9 minigene and its stable nonsense mutant cell lines are constructed successfully. The cell lines can be used to screen the drugs treating the nonsense mutation-caused hemophilia according to PTC read-through approaches.

[Cloning and characterization of a novel trinucleotide repeat-containing gene GARP from Euplotes octocarinatus].

The expansion of trinucleotide repeats in genome is related to the phthogenesis of several neurodegenerative diseases. A GARP (glutamic acid-rich protein) gene was isolated from the macronuclear plasmid mini library of Euplotes octocarinatus. A micronuclear version of the GARP gene was amplified by polymerase chain reaction. The macronuclear DNA molecule carrying the GARP gene is 460 bp long and shows the characteristics of macronuclear chromosomes of hypotrichous ciliates. One of the three cysteines is encoded by the opal codon TGA(88-90). The predicted open reading frame encodes a 112-amino acid polypeptide, with a predicted molecular mass of 13 kDa and an isoelectric point of 3.82. Micronuclear version of the GARP gene contains two internal eliminated sequences (IES), IES1 and IES2. IES1 is 41 bp long and is flanked by 5'-GA-3' direct repeats. IES2 is 41 bp long and flanked by 5'-TA-3' direct repeats. Transcriptional activity of GARP gene was confirmed by reverse transcription polymerase chain reaction (RT-PCR).

Therapeutic potential of chlorotoxin-like neurotoxin from the Chinese scorpion for human gliomas.

Chlorotoxin, one of the key toxins in scorpion Leiurus quinquestriatus venom, has been shown to bind specifically to glioma cell surface as a specific chloride channel blocker. In this study, a purified, recombinant chlorotoxin-like peptide from the scorpion Buthus martensii Karsch (named rBmK CTa) was characterized by in vivo and in vitro studies. The results from cell proliferation assay with human glioma (SHG-44) cells showed that rBmK CTa inhibits the growth of glioma cells in a dose-dependent manner, with an IC(50) value of approximately 0.28microM. Under the same conditions, the IC(50) value for normal astrocytes increased to 8microM. This clearly indicated that rBmK CTa had specific toxicity against glioma cells but not astrocytes. Results from whole-cell patch-clamp recording showed that chloride current in SHG-44 was inhibited by rBmK CTa in a voltage-dependent manner and percent inhibitions for the blocking action of rBmK CTa (0.07 and 0.14microM) on I(Cl) was 17.64+/-3.06% and 55.86+/-2.83%, respectively. Histological analysis of rBmK CTa treated mice showed that brain, leg muscle and cardiac muscle were the target organs of this toxin. These results suggest that rBmK CTa may have potential therapeutic application in clinical treatment of human glioma. It represents an approach for developing a novel therapeutic agent.

Identification of translational release factor eRF1a binding sites on eRF3 in Euplotes octocarinatus.

Translation termination in eukaryotes is mediated by two polypeptide chain-release factors, eRF1 and eRF3. eRF1 recognizes stop signals, while eRF3 is a ribosome-dependent and eRF1-dependent GTPase. eRF1 forms a stable complex with eRF3 in vivo and in vitro. In the present study, a variety of truncated forms of Euplotes octocarinatus eRF3 were created, and systematic analysis of the interaction between E. octocarinatus eRF1a and these eRF3 mutants was performed by employing both in vivo a yeast two-hybrid assay and in vitro a pull-down assay. The results demonstrated that a short portion of the C-terminal domain of eRF3 is sufficient for eRF1a binding in E. octocarinatus. Specifically, the eRF1a-binding sites on eRF3 are located at a region containing amino acid residues 640-723 in E. octocarinatus eRF3. Amino acid sequence analysis of eRF3 from E. octocarinatus, humans and yeast showed that the eRF1a binding domain on E. octocarinatus eRF3 was similar to that of yeast eRF3 but different from that of human eRF3.

[Cloning and sequence analysis of a novel member of the rab gene family from Euplotes octocarinatus].

Rab proteins belong to a subfamily of small GTP-binding proteins of the Ras superfamily, which play an important role in intracellular vesicular traffic. In this study, a rab gene was obtained from Euplotes octocarinatus by polymerase chain reaction (PCR) and RT-PCR. The rab gene from macronucleic DNA was 884 bp in length, including non-coding regions and telomeric sequences at both ends. The rab gene from micronuclear DNA (723 bp), lacking of internal eliminated sequences, was identical to rab gene from macronuclear DNA. RT-PCR showed that the opening reading frame of the rab gene was 663 bp long. The rab gene from macronuclear DNA contained an intron of 60 bp at the position from 153 bp to 212 bp of macronuclear DNA. The rab gene had two in-frame TGAs encoding for cysteine in Euplotes octocarinatus. The rab gene used TAG as stop codon, which was the first report in Euplotes octocarinatus. The result of BLAST in NCBI demonstrates that the Rab shares a homology of 49-52% at the amino acid level with Rab1 proteins from a number of other eukaryote, which suggesting that the Rab is a Rab1 homolog. The rab gene was therefore designated Eo-rab-1N (GenBank accession number: DQ105562). The evolution of Eo-rab-1N was analyzed using phylogenetic tree of amino acids sequences of Rab1 obtained from GenBank.

Expression, characterization and immunolocalization of translation termination factor eRF3 in the ciliate Euplotes octocarinatus.

Class II polypeptide release factor eRF3 stimulates translation termination in a GTP-dependent manner. Recent data show that eRF3 is also involved in cell cycle regulation apart from its function in translation. Here we show that recombinant Eo-eRF3 from the ciliate Euplotes octocarinatus expressed in Escherichia coli can be tested for its ribosome-dependent GTPase activity using an in vitro system. Moreover, polyclonal antibodies against recombinant Eo-eRF3 were used to determine the localization of Eo-eRF3 using immunofluorescence and immunoelectron microscopy, which showed that the Eo-eRF3 is distributed not only around the macronucleus, but also in basal bodies in the cortex of E. octocarinatus cells. The results suggest that Eo-eRF3 may be involved in cytoskeleton organization in addition to its function in translation termination.

[Refinement of DSAP1 locus and mutation detection for candidate genes].

Disseminated superficial actinic porokeratosis (DSAP) is an uncommon autosomal dominant chronic keratinization disorder,characterized by multiple superficial keratotic lesions surrounded by a slightly raised keratotic border. In previous studies,the disease gene was mapped to 12q23. 2-24.1 (DSAP1), and 15q25. 1-26.1 (DSAP2). In this study,genome-wide scan was performed in two unrelated six-generation DSAP pedigrees to localize and identify the candidate gene(s) of disease. Linkage analysis showed that the cumulative maximum two-point lod score of 8.28 was obtained with the marker D12S84 at a recombination fraction theta of 0.00. Haplotype analysis defined an 8.0 cM critical region for DSAP gene(s) between markers D12S330 and D12S354 on 12q24. 1-q24. 2, which partially overlapped with the region identified for DSAP1. DNA sequencing of the coding exons of six candidate genes (CRY1, PWP1, ASCL4, PRDM4, KIAA0789 and CMKLR1) on the basis of their location in the critical overlap interval, failed to detect any mutation in DSAP patients. Thus, it is likely that these genes are not involved in DSAP.