Out-of-set association analysis of lung cancer drugs and symptoms based on clinical case data mining.

BACKGROUND: There are 1.8 million lung cancer deaths worldwide, accounting for 18% of global cancer deaths, including 710,000 in China, accounting for 23.8% of all cancer deaths in China. OBJECTIVE: To explore the out-of-set association rules of lung cancer symptoms and drugs through text mining of traditional Chinese medicine (TCM) treatment of lung cancer, and form medical case analysis to analyze the experience of TCM syndrome differentiation in its treatment. METHODS: The medical records of all patients diagnosed with lung cancer in Nanjing Chest Hospital from January to December 2018 were collected, and the out-of-set association analysis was performed using the MedCase v5.2 TCM clinical scientific research auxiliary platform based on the frequent pattern growth enhanced association analysis algorithm. RESULTS: In terms of TCM treatment of lung cancer, the clinical symptoms with high correlation included cough, expectoration, chest distress, and white phlegm; and the drugs with high correlation included Pinellia ternata, licorice root, white Atractylodes rhizome, and Radix Ophiopogonis; with the prescriptions based on Erchen and Maimendong decoctions. CONCLUSION: This analytical study of the medical cases of TCM treatment for lung cancer was performed using data mining techniques, and the out-of-set association rules between clinical symptoms and drugs were analyzed, including the understanding of lung cancer in TCM. Moreover, the essence of experience in drug use was gathered, providing significant scientific guidance for the clinical treatment of lung cancer.

Squamous-columnar junction of Von Ebner's glands may be a significant origin of squamous cell carcinomas in the base of the tongue.

Objectives: The histological origin of base of the tongue (BOT) carcinomas is still elusive, and most studies have been focusing on the lingual tonsil. In this study, we sought to identify the existence of the squamous-columnar junction (SCJ) in the human Von Ebner's glandular duct and explored the potential of that in forming squamous cell carcinomas in BOT. Materials and methods: The specific genomes of BOT carcinoma were acquired and screened out by The Cancer Genome Atlas (TCGA) database analysis. The 4-nitroquinoline-1-oxide (4-NQO)-treated mouse model was used to explore the transformation of SCJ during cancerization. We used immunohistochemistry to confirm the characteristics of SCJ in human Von Ebner's gland, which were further compared with those in the anus and cervix. Results: The SCJ in the human Von Ebner's glandular duct was found to be similar to that of the cervix and anus. The transformation zone in the 4-NQO-treated mouse model had a multilayered epithelium structure similar to that of HPV16-transgenic mice. In human, the transformation zone of Von Ebner's gland is also similar to that of the cervix and anus. Conclusion: It is the first time that the existence of SCJ in the opening of the human Von Ebner's glandular duct was confirmed. The SCJ of Von Ebner's glands may be a significant origin of squamous cell carcinomas in BOT.

VEGF gene transfection restores the angiogenesis of oral submucous fibrosis in mice.

BACKGROUND: To explore the effectiveness of adenovirus-enhanced green fluorescent protein-vascular endothelial growth factor165 (AD-EGFP-VEGF165) transfection on fibroblasts from mice, and we assessed whether VEGF165 restores the angiogenesis of oral submucous fibrosis (OSF) in mice. METHODS: AD-EGFP-VEGF165 and AD-EGFP were transfected into fibroblasts from mouse buccal tissues in vitro. The expression of VEGF before and after transfection was detected by RT-qPCR and ELISA in each group of fibroblasts. Fifteen OSF mice (pre-experimental construction) were randomly divided into 3 groups, and equal amounts of AD-EGFP-VEGF165 virus, AD-EGFP virus, and saline were injected into the buccal submucosal tissue of OSF mice. The expression of VEGF and local tissue angiogenesis were observed and measured in each group of animals. RESULTS: The Ad-EGFP-VEGF165-transfected fibroblasts increased human and mouse VEGF expression compared to the Ad-EGFP group and control group (P<0.05). The buccal submucosal tissue of mice was injected with Ad-EGFP-VEGF165 after the 6th day, and the expression of VEGF was effectively expressed in AD-EGFP-VEGF165 group (P<0.05), while no positive expression observed in other groups. and the number of microvessels in the AD-EGFP-VEGF165 group increased significantly compared to the other groups (P<0.05). CONCLUSIONS: Ad-EGFP-VEGF165 can be successfully transfected into fibroblasts from mice, and restored the angiogenesis of OSF in mice.

The preliminary experience of methylene blue assisted laparoscopy in the treatment of renal parapelvic cysts.

Renal cyst is a common disease in humans and laparoscopic renal cyst decortication is the gold standard for treatment. However, specialized surgical skills are required for the treatment of renal parapelvic cysts. In this study, we describe an improved laparoscopic method for the treatment of renal parapelvic cysts involving the use of continuous infusion of methylene blue. Sixteen patients with renal parapelvic cyst were enrolled in this study. All patients underwent retrograde ureteral catheterization, with continuous perfusion of the renal pelvis using a solution of 0.2% methylene blue and saline, during laparoscopic decortication of the parapelvic cyst. In one patient, the cyst communicated with the renal collection system which was injured, but this was immediately repaired intraoperatively. All operations were successful, and none was converted to open surgery. There were no occurrences of persistent urinary fistula, bleeding, or other complications postoperatively. All patients were followed-up for 3-24 months, and results of postoperative imaging investigations revealed that all of our patients experienced either complete recovery or a greater than 50% decrease in size of the cysts. Our study demonstrates that methylene blue-assisted laparoscopic treatment is a safe, effective and practical method for the treatment of renal parapelvic cysts.

Long non-coding RNA LOC541471: A novel prognostic biomarker for head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSCC) is an aggressive cancer. Early detection and management of HNSCC may prevent progression of the disease. Long non-coding RNAs (lncRNAs) may serve as prognostic biomarkers for various cancer types. The current study downloaded an RNA-Seq dataset containing 43 tumor-normal pairs. An independent t-test identified that the expression level of lncRNA LOC541471 was significantly increased in tumor tissues compared with healthy tissues. Additionally, the current study demonstrated that high lncRNA LOC541471 expression was significantly associated with increasing lymph node metastasis classification and perineural invasion. A multivariate Cox regression analysis revealed that high lncRNA LOC541471 expression levels were an independent predictor for reduced overall survival (n=487) and relapse-free survival (n=355). According to the anatomic neoplasm subdivision, HNSCC samples were classified as oropharyngeal carcinoma (n=297), oral carcinoma (n=80), laryngeal carcinoma and hypopharyngeal carcinoma (n=123). A negative association was revealed between lncRNA LOC541471 expression and overall survival in all subtypes of HNSCC. Therefore, lncRNA LOC541471 is significantly negatively associated with overall survival and relapse-free survival of patients with HNSCC and may be considered a potential prognostic factor for HNSCC.

Identification and validation a TGF-ß-associated long non-coding RNA of head and neck squamous cell carcinoma by bioinformatics method.

BACKGROUND: The role of transforming growth factorß (TGF-ß)-induced tumor progression in advanced malignancy is well established, but the involvement of long non-coding RNAs (lncRNAs) in TGF-ß signaling remains unclear. This study aimed to identify TGF-ß-associated lncRNAs in head and neck squamous cell carcinoma (HNSCC). METHODS: Expression profiling of lncRNAs was obtained using Gene Expression Omnibus and The Cancer Genome Atlas. Real-time quantitative PCR was used to analyze the expression of EPB41L4A-AS2 in HNSCC cell line. We used bioinformatics resources (DAvID) to conduct Gene Ontology biological processes and KEGG pathways at the significant level. Wound healing assay, cell migration and invasion assays, were used to examine the effects of EPB41L4A-AS2 on tumor cell metastasis in vivo. Protein levels of EPB41L4A-AS2 targets were determined by western blot. RESULTS: A novel TGF-ß-associated lncRNA, EPB41L4A-AS2, was found downregulated by TGF-ß and associated with invasion and metastasis. The relationship of EPB41L4A-AS2 with the clinicopathological features and prognosis of HNSCC patients was evaluated. Bioinformatic analyses revealed that EPB41L4A-AS2 may be involved in processes associated with the tumor-associated signaling pathway, especially the TGF-ß signaling pathway. Furthermore, a TGF-ß-induced epithelial-to-mesenchymal transition (EMT) model was established. Low EPB41L4A-AS2 expression was determined, and overexpression of this gene inhibited cell migration and invasion in the EMT model. Moreover, EPB41L4A-AS2 suppressed TGFBR1 expression. CONCLUSIONS: EPB41L4A-AS2 might serve as a negative regulator of TGF-ß signaling and as an effective prognostic biomarker and important target in anti-metastasis therapies of HNSCC patients.

Single-bundle modified patellar tendon versus double-bundle tibialis anterior allograft ACL reconstruction: a prospective randomized study.

PURPOSE: The purpose of this study was to prospectively compare the outcomes of single-bundle (SB) anterior cruciate ligament (ACL) reconstruction with modified bone-patellar tendon-bone (BPTB) allograft and double-bundle (DB) reconstruction with tibialis anterior allograft. METHODS: With 94 patients enroled in the study, 43 subjects who had SB ACL reconstruction with modified BPTB allograft (group S) and 41 subjects of DB ACL reconstruction with tibialis anterior allograft (group D) were followed up for a minimum of 2 years. Clinical outcomes including Lachman and pivot-shift tests, KT-1000 arthrometer measurements, and the International Knee Documentation Committee (IKDC) classification, Lysholm and Tegner activity scores were compared between the two groups at the last follow-up. RESULTS: The mean graft size of the group S, the anteromedial bundle and posterolateral bundle in group D were 9.9 ± 0.2, 7.5 ± 0.4 and 6.6 ± 0.4 mm, with statistically significant difference between the group S graft to either bundle of group D grafts (p < 0.001). At the last follow-up, there was no statistical difference between the two groups for the Lachman test, pivot-shift test and side-to-side difference. Substantial improvements in the subjective knee function scores were achieved in both groups, but without significant difference between the two groups. CONCLUSIONS: After a 2-year minimum follow-up, SB ACL reconstruction based on modified BPTB allograft achieved similar clinical outcomes to DB reconstruction with tibialis anterior allograft in knee stability, both anterior-posterior and rotational, as well as knee function. The modified BPTB allograft was recommended as an ideal graft option for the SB ACL reconstruction. LEVEL OF EVIDENCE: Therapeutic, randomized controlled study, Level II.

CDC42 inhibition suppresses progression of incipient intestinal tumors.

Mutations in the APC or ß-catenin genes are well-established initiators of colorectal cancer, yet modifiers that facilitate the survival and progression of nascent tumor cells are not well defined. Using genetic and pharmacologic approaches in mouse colorectal cancer and human colorectal cancer xenograft models, we show that incipient intestinal tumor cells activate CDC42, an APC-interacting small GTPase, as a crucial step in malignant progression. In the mouse, Cdc42 ablation attenuated the tumorigenicity of mutant intestinal cells carrying single APC or ß-catenin mutations. Similarly, human colorectal cancer with relatively higher levels of CDC42 activity was particularly sensitive to CDC42 blockade. Mechanistic studies suggested that Cdc42 may be activated at different levels, including at the level of transcriptional activation of the stem cell-enriched Rho family exchange factor Arhgef4. Our results indicate that early-stage mutant intestinal epithelial cells must recruit the pleiotropic functions of Cdc42 for malignant progression, suggesting its relevance as a biomarker and therapeutic target for selective colorectal cancer intervention.

Targeted p16(Ink4a) epimutation causes tumorigenesis and reduces survival in mice.

Cancer has long been viewed as a genetic disease; however, epigenetic silencing as the result of aberrant promoter DNA methylation is frequently associated with cancer development, suggesting an epigenetic component to the disease. Nonetheless, it has remained unclear whether an epimutation (an aberrant change in epigenetic regulation) can induce tumorigenesis. Here, we exploited a functionally validated cis-acting regulatory element and devised a strategy to induce developmentally regulated genomic targeting of DNA methylation. We used this system to target DNA methylation within the p16(Ink4a) promoter in mice in vivo. Engineered p16(Ink4a) promoter hypermethylation led to transcriptional suppression in somatic tissues during aging and increased the incidence of spontaneous cancers in these mice. Further, mice carrying a germline p16(Ink4a) mutation in one allele and a somatic epimutation in the other had accelerated tumor onset and substantially shortened tumor-free survival. Taken together, these results provide direct functional evidence that p16(Ink4a) epimutation drives tumor formation and malignant progression and validate a targeted methylation approach to epigenetic engineering.

Genome-wide DNA methylation and gene expression patterns provide insight into polycystic ovary syndrome development.

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women. However, the epigenetic mechanism involved in PCOS progression remains largely unknown. Here, combining the DNA methylation profiling together with transcriptome analysis, we showed that (i) there were 7929 differentially methylated CpG sites (ß > 0.1, P < 0.05) and 650 differential transcripts (fold change > 1.5, P < 0.005) in PCOS compared to normal ovaries; (ii) 54 genes were identified with methylated levels that were correlated with gene transcription in PCOS; and (iii) there were less hypermethylated sites, but many more hypomethylated sites residing in CpG islands and N_Shore in PCOS. Among these genes, we identified that several significant pathways, including the type I diabetes mellitus pathway, p53 signaling pathway and NOD-like receptor signaling pathway, and some immune and inflammatory diseases may be highly involved in PCOS development. These results suggested that differences in genome-wide DNA methylation and expression patterns exist between PCOS ovaries and normal ovaries; epigenetic mechanisms may in part be responsible for the different gene expression and PCOS phenotype. All of this may improve our understanding of the basic molecular mechanism underlying the development of PCOS.

The horizontal Y-shaped graft with respective graft tension angles in anatomical two-bundle medial patellofemoral ligament reconstruction.

PURPOSE: Various techniques for medial patellofemoral ligament (MPFL) reconstruction have been described with two bundles of graft tensioned simultaneously. The present study was to introduce an anatomical reconstruction procedure using a horizontal Y-shaped graft with respective graft tension angles and report the preliminary results. METHODS: A surgical technique for MPFL reconstruction using a horizontal Y-shaped semitendinosus tendon autograft with two bundles tensioned at 0° and 30° of knee flexion was described in detail. The patellar stability was evaluated with the apprehension test and an axial computed tomography (CT) scan at 30° of knee flexion. The knee function was evaluated using the Lysholm and Kujala scores. RESULTS: No recurrent dislocation or subluxation was reported for 45 patients at a mean of 33.7-month follow-up. On CT images, congruence angle, patellar tilt angle, lateral patellar angle and lateral displacement were restored to the normal range. At the last follow-up, the mean Lysholm score improved from 51.8±6.2 to 91.7±4.1 and mean Kujala score was from 53.4±5.3 to 90.9±6.6 (P<0.01). CONCLUSIONS: The present anatomical MPFL reconstruction technique with a horizontal Y-shaped two-bundle graft tensioned at respective knee flexion angles could not only recreate the fan-shape of MPFL but also mimic the function bundles of native ligament. Clinical follow-up confirms the good restoration of the patellar stability and significant improvement of knee function without special complications. LEVEL OF EVIDENCE: Therapeutic, Level IV.

Expressions of ER, PR, HER-2, COX-2, and VEGF in primary and relapsed/metastatic breast cancers.

In the present study, we evaluated expressions of estrogen receptor (ER), progestin receptor (PR), human epidermal growth factor receptor-2 (HER-2), cyclooxygenase-2 (COX-2), and vascular endothelial growth factor (VEGF) in primary and relapsed/metastatic breast cancers to elucidate the clinical significance of these markers. The markers were evaluated by immunohistochemistry in specimens of 50 patients with primary or metastatic breast cancer. Positive rates of ER were significantly (p = 0.002) higher in primary versus relapsed/metastatic breast cancer (70 vs. 38 %, respectively). The VEGF positive expression rates were also significantly higher in primary versus metastatic cancer (82 vs. 38 %, respectively; p < 0.001). By contrast, positive rates of HER-2 and COX-2 were not significantly different between different types of cancer. COX-2 correlated with HER-2 expression in both primary and relapsed/metastatic focuses of breast cancer. COX-2 also correlated with VEGF expression in primary breast cancer. Expressions of ER, PR, HER2, and COX-2 did not correlate between primary and relapsed/metastatic breast cancers, indicating that the treatment decision should be made according to the status of these markers in relapsed/metastatic focuses. The total change rates of ER, PR, HER-2, COX-2, and VEGF were 26, 18, 10, 30, and 58 %, respectively. In conclusion, HER-2 and COX-2, along with VEGF, appear to play a role in the development and progression of breast cancer. In addition, all of the studied markers may serve as indicators of prognosis.

Arthroscopic single-bundle ACL reconstruction with modified double-layer bone-patellar tendon-bone allograft.

PURPOSE: The objective of present study was to introduce a modified double-layer bone-patellar tendon-bone (BPTB) allograft for arthroscopic single-bundle ACL reconstruction and investigate the clinical outcomes. METHODS: From 2007 to 2009, a total of 136 patients underwent arthroscopic single-bundle ACL reconstructions with BPTB allograft. Of which, 66 patients were with double-layer BPTB allograft (Group 1), and 70 patients were with conventional BPTB allograft (Group 2). Clinical outcomes including Lachman and pivot-shift tests, KT-1000 arthrometer measurements, and Lysholm and Tegner activity scores were compared between the two groups at a 2-year minimum follow-up. RESULTS: Forty-six patients in each group were at a two-year minimum follow-up. The mean side-to-side difference on the KT-1000 arthrometer was 1.2 ± 1.2 mm for group 1 and 2.1 ± 1.9 mm for group 2, with significant difference between the two groups (p = 0.017). The knee function was significantly better for group 1 than for group 2, because the mean Lysholm score was 94.2 ± 4.8 points versus 86.6 ± 7.1 points (p = 0.000), and the median Tegner score was 8 (range 5-10) points versus 6 (range 4-10) points (p = 0.001). CONCLUSIONS: On the basis of the KT-1000 arthrometer evaluation and clinical measures, single-bundle ACL reconstruction with double-layer BPTB allograft achieves significantly lesser anterior laxity and better knee function than a single-layer allograft reconstruction. LEVEL OF EVIDENCE: Therapeutic, retrospective comparative study, Level III.

[Expression and significance of basic fibroblast growth factor in infant vascular anomalies].

PURPOSE: To investigate the expression of basic fibroblast growth factor (bFGF) in infant's peripheral blood and tumor blood of vascular malformation and peripheral venous blood of hemangioma, and the possibility to differentiate hemangioma from vascular malformations by detecting bFGF level in peripheral blood. METHODS: The level of bFGF in peripheral blood(49 vascular malformations ,32 hemangioma cases and 23 normal cases) and tumor blood(14 venous malformations) of infants was measured by ELISA.SPSS11.5 software package was used to analyze the data and student's t test and ANOVA were used to determine the difference between different groups. RESULTS: The expression of bFGF in tumor blood from infants with venous malformations was significantly higher than that in peripheral blood (P<0.05); No significant difference of bFGF level in peripheral blood was found between hemangioma,vascular malformation and normal infants(P>0.05). CONCLUSIONS: The level of bFGF in tumor blood of from infants with venous malformation was higher than that in peripheral blood; Examination of bFGF in peripheral blood can not differentiate hemangioma from vascular malformations.

Perilipin gene 1237 T > C polymorphism is not associated with obesity risk in northern Chinese Han adults.

OBJECTIVE: To identify the association between PLIN 1237 polymorphism and obesity in Chinese Han adults. METHODS: A total of 994 adults (157 obese subjects, 322 overweight subjects, and 515 normal controls) were recruited from two rural communities. PLIN 1237 polymorphism was genotyped by polymerase chain reaction-restriction-fragment-length-polymorphism (PCR-RFLP). Association between PLIN polymorphisms and obesity status was estimated by ordinal logistic regression. RESULTS: The three genotypes of PLIN 1237 were detected with a percentage of 54.3%, 37.1%, and 8.6% in TT, TC, and CC genotypes, respectively. For the PLIN 1237 polymorphism locus, the frequency of alleles T and C was 0.73 and 0.27, respectively. The PLIN 1237 polymorphisms were in Hardy-Weinberg equilibrium. PLIN 1237 polymorphism was not associated with obesity. The odds ratio for overweight or obesity for the CC+TC genotype was 0.8 (0.4, 1.4) in women (P = 0.4) and 0.6 (0.3, 1.3) in men (P = 0.2) after adjustment for age, education, household income and alcohol consumption, smoking, and physical activity. CONCLUSION: Chinese Han adults have a lower frequency of variant-allele C in PLIN 1237. PLIN 1237 T > C polymorphism is not significantly associated with obesity in northern Chinese adults.

[Antiangiogenic and antitumor effects of vascular endothelial growth factor small interfering RNA on Tca8113 human tongue squamous cell carcinoma xenografts in vivo].

OBJECTIVE: To examine the antiangiogenic and antitumor effects of vector-based small interfering RNA (siRNA) targeting vascular endothelial growth factor (VEGF) on human tongue squamous cell carcinoma xenografts in vivo. METHODS: Tca8113 human tongue cancer nude mice xenograft model was established, and subsequently divided into four groups randomly (5/group). Two siRNA targeting VEGF constructed in eukaryotic expression vector (PU-VEGF-siRNA1, PU-VEGF-siRNA2) were injected intratumor and peritumor with lipofectamine 2000, respectively. No siRNA vector injected and non-injected tumors were used as experimented and negative controlled, respectively. Animals were injected one time every 3 days for a total of 10 times. Three days after the last injection, the weigh and volume of tumors, and intratumor microvessel density (MVD) were measured. The expression of VEGF in xenograft tumors was detected by reverse transcription polymerase chain reaction (RT-PCR), Western blotting and immunohistochemistry. The cell apoptosis and cell cycle analysis of tumors were detected by Tunel and Flow cytometry, respectively. RESULTS: Compared to the experimental and negative controls, the percentage of cells in the G(1) phase increased (P < 0.05), the expression of VEGF on both mRNA and protein level, the tumor weigh and volume, and MVD decreased in the PU-VEGF-siRNA2 group (P < 0.05), and more apoptosis was induced (P < 0.01). But significant differences were not noted between PU-VEGF-siRNA1 group and two controls (P > 0.05). CONCLUSIONS: VEGF-siRNA can reduce VEGF expression, inhibit tumor growth and angiogenesis, and induce apoptosis in Tca8113 cell carcinoma in vivo. Different VEGF-siRNA may have different effect in vivo.

[Suppression of vascular endothelial growth factor expression by vector-based small interfering RNA in human tongue squamous carcinoma cell line Tca8113].

OBJECTIVE: To assess suppression effects of vector-based small interfering RNA (siRNA) on vascular endothelial growth factor (VEGF) expression of human tongue squamous carcinoma cell line (Tca8113) in vitro. METHODS: Two siRNA targeting VEGF constructed in eukaryotic expression vector (Pu-VEGF-siRNA1, Pu-VEGF-siRNA2), eukaryotic expression vector as the experiment control, all of which were transfected into Tca8113 cells with Lipofectamine 2000. Non-transfection cell was used as negative control. VEGF mRNA and protein were detected by reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry and enzyme linked immunosorbent assay (ELISA), respectively. RESULTS: Compared to the experimental and negative controls, the expression of VEGF mRNA and protein were significantly decreased in the Pu-VEGF-siRNA1 group and Pu-VEGF-siRNA2 group. But there were no significant differences between two controls (P > 0.05). CONCLUSION: Vector-based siRNAs targeting VEGF are efficient in down-regulating VEGF expression in Tca8113 cells.

A combined DNA vaccine encoding BCSP31, SOD, and L7/L12 confers high protection against Brucella abortus 2308 by inducing specific CTL responses.

We constructed a combined DNA vaccine comprising genes encoding the antigens BCSP31, superoxide dismutase (SOD), and L7/L12 and evaluated its immunogenicity and protective efficacy. Immunization of mice with the combined DNA vaccine offered high protection against Brucella abortus (B. abortus) infection. The vaccine induced a vigorous specific immunoglobulin G (IgG) response, with higher IgG2a than IgG1 titers. Cytokine profiling performed at the same time showed a biased Th1-type immune response with significantly increased interferon-gamma and tumor necrosis factor-alpha stimulation. CD8(+), but not CD4(+), T cells accumulated at significantly higher levels after administration of the vaccine. Granzyme B-producing CD8(+) T cells were significantly higher in number in samples prepared from combined DNA-vaccinated mice compared with S19-vaccinated mice, demonstrating that the cytotoxicity lysis pathway is involved in the response to Brucella infection. The success of our combined DNA vaccine in a mouse model suggests its potential efficacy against brucellosis infection in large animals.

Polo-like kinase 1 may regulate G2/M transition of mouse fertilized eggs by means of inhibiting the phosphorylation of Tyr 15 of Cdc2.

Polo-like kinase 1(Plk1) has been reported to be a multifunctional kinase that plays pivotal regulatory roles in microtubule assembly during mammalian early embryonic mitosis. In the present study, we examined the expression of Plk1 at protein and mRNA level in mouse fertilized eggs by Western blot and RT-PCR. We also examined the kinase activity of Plk1. At various developmental phases of mouse one-cell stage embryos, both the protein and the mRNA of Plk1 were uniformly distributed; but the kinase activity of Plk1 increased at G2/M phase and decreased at the end of M phase. At the meantime, the phosphorylation of Tyr 15 of Cdc2 was inhibited at M phase. To investigate its function in mammalian fertilized eggs further, we used specific short hairpin RNAs (shRNA) and scytonemin, the putative inhibitor of Plk1 to suppress the activity of Plk1 in mouse fertilized eggs. Upon blockage of the activation of with Plk1 shRNA and scytonemin in mouse one-cell stage embryos, the cleavage rate decreased and the phosphorylation level of Tyr 15 of Cdc2 increased. These results imply that the Plk1 may regulate cell cycle progression of mouse fertilized eggs by means of inhibiting the phosphorylation of Tyr 15 of Cdc2.