30 results on '"Cheung, Annie N. Y."'
Search Results
2. Evaluation of an Isothermal Amplification HPV Assay on Self-Collected Vaginal Samples as Compared to Clinician-Collected Cervical Samples.
- Author
-
Chan, Aaron H. Y., Ngu, Siew-Fei, Lau, Lesley S. K., Tsun, Obe K. L., Ngan, Hextan Y. S., Cheung, Annie N. Y., and Chan, Karen K. L.
- Subjects
- *
HUMAN papillomavirus - Abstract
This study aimed to evaluate the concordance of HPV results between the SentisTM HPV assay (Sentis) (BGI Group, Shenzhen, China), an isothermal amplification-based HPV assay, on self-collected and clinician-collected samples and the agreement of Sentis on self-collected samples with the BD OnclarityTM HPV assay (Onclarity) (Becton, Dickinson, and Company, Franklin Lakes, New Jersey, USA), a PCR-based HPV assay, on clinician-collected samples. This was a prospective study of 104 women attending the colposcopy clinic for abnormal smears. After informed consent, participants self-collected vaginal samples before having clinician-collected cervical samples. Self-collected samples underwent HPV testing with Sentis (Self-Sentis HPV) and clinician-collected samples were tested with Sentis (Clinician-Sentis HPV) and Onclarity (Clinician-Onclarity), which was used as a reference standard. The concordance was assessed using Cohen's kappa. The prevalence of HPV and the acceptability of self-sampling were also evaluated. The concordance rate between Self-Sentis HPV and Clinician-Sentis HPV was 89.8% with a kappa of 0.769. The concordance rate between Self-Sentis HPV and Clinician-Onclarity was 84.4% with a kappa of 0.643. The prevalence of HPV was 26.0% on Clinician-Onclarity, 29.3% on Clinician-Sentis HPV, and 35.6% on Self-Sentis HPV. Overall, 65% of participants would undergo self-sampling again. This was attributed to mainly not feeling embarrassed (68%) and being convenient (58%). Our study showed a substantial agreement between Self-Sentis HPV with Clinician-Sentis HPV and Clinician-Onclarity. Self-sampling was also shown to be a generally well-accepted method of screening. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. HONG KONG: CERVICAL CANCER SCREENING.
- Author
-
Cheung, Annie N. Y.
- Subjects
- *
CERVICAL cancer diagnosis , *CANCER diagnosis , *MEDICAL screening , *CANCER in women - Abstract
Women and cervical cancer Hong Kong has a population of 6.8 million. Life expectancy for women at birth was estimated to be 84.3 years in 2003. During the period 1988-1992, Hong Kong's ASR for cervical cancer was ~17; this is lower than that of the Thai, Korean, Filipino, and Singaporean-Chinese populations, but higher than in Japan (Figure 3) [59]. History of cervical screening Until 2004, there was no centrally organised, systematic cervical screening programme (CSP) in Hong Kong. Screening was generally opportunistic or included as part of a general checkup. Screening practices varied between different healthcare providers and there was little collaboration between public and private sector healthcare. Approximately 45% of women, primarily those who were educated and health-conscious, were being screened. This somewhat random coverage was not equitable or efficient, and was unlikely to be cost-effective. Despite this, the ASR for cervical cancer declined steadily between 1983 and 2000, the most significant fall being among women 50-65 years of age. About 50% of cases are diagnosed at stage 1. A centralised cervical screening programme for Hong Kong First approved in 2001, the Hong Kong CSP was launched in March 2004. The goal is to reduce the incidence of, and mortality from, cervical cancer by facilitating regular screening for all patients at risk. Stated objectives are to (i) raise public awareness, (ii) improve population coverage, (iii) promote more equitable and efficient screening, (iv) build quality assurance into the services through professional education and clear guidelines, (v) support private sector activity. Following statistical modelling, the target population was set to include all women 25-64 years of age who have had sex. After two clear annual checks, screening will be scheduled every 3 years, and discontinued at 65 years if the previous Pap smears are normal. Using triennial screens, it was estimated that if coverage raised to 80% of the population, there would be ~75% decrease in the number of cases of cervical cancer. It is hoped that the CSP will increase coverage from 43% to 60% within 3 years, and to 80-85% in the long term. During the period March 2004-June 2005, almost 150 000 women were enrolled in the CSP. Based on age quintiles, enrolment has been highest among women 40-44 years of age. There are large variations between districts. The communication network The CSP incorporates a centralised information system with a website (available at http://www.csis.gov.hk) accommodating the input of data online. The central registry will include screening results, follow-up investigations, and demographic data, and will generate reminder letters to women due for screening. Practitioners will be emailed details of patients recalled, and alerted to abnormal smears. The system will also provide data for ongoing evaluation and monitoring. Public education regarding cervical cancer has not been a priority in Hong Kong; therefore, communication and promotion are priorities. Attention was drawn to the disease when Anita Mui, a popular singer and movie star, died from cervical cancer in December 2003. She was 40 years of age. Her death coincided with the launch of the CSP and may have aided receptivity. Quality assurance All registered doctors and trained nurses may collect cervical smears. Accreditation for participation is coordinated by the Society for Colposcopy and Cervical Pathology. Health professionals whose smears do not meet CSP minimum standards will be invited to attend refresher training. Healthcare professionals who supply smears to the CSP are provided with a training kit, which covers technical skills and communication approaches. A survey of women will be undertaken to gauge levels of satisfaction with the CSP and the Pap smear.… [ABSTRACT FROM AUTHOR]
- Published
- 2006
4. Population-based case-control study of HER2 genetic polymorphism and breast cancer risk.
- Author
-
Chan, Kelvin Y K, Cheung, Annie N Y, Yip, Shea-Ping, Ko, Hin-Hin, Lai, Tsz-Wan, and Khoo, Ui-Soon
- Published
- 2002
5. Immunoexpression of p16 in uterine leiomyomas with infarct-type necrosis: an analysis of 35 cases.
- Author
-
Ip, Philip P, Lim, Diana, Cheung, Annie N Y, and Oliva, Esther
- Subjects
- *
P16 gene , *GENE expression , *UTERINE fibroids , *NECROSIS , *CANCER relapse - Abstract
Aims Uterine leiomyosarcomas frequently show p16 immunoexpression. However, p16 may also be expressed in some benign leiomyoma variants such as leiomyomas with bizarre nuclei and cellular leiomyomas, limiting its utility as a biomarker to distinguish between benign and malignant neoplasms. We investigated p16 expression in leiomyomas with infarct-type necrosis, tumours which may sometimes be misinterpreted as smooth muscle tumours of uncertain malignant potential or even leiomyosarcoma on conventional light microscopy. Methods and results p16 immunostaining was performed on 35 leiomyomas with infarct-type necrosis and the staining pattern was analysed. Staining was classified as absent, scattered/isolated, <33-, 33-66- or >66%-positive cells, and was assessed in the areas immediately surrounding and distant from the infarct. The median age of patients was 44 years. Seventeen had hormonal/non-hormonal drugs and three were pregnant. The median tumour size was 7.25 cm. The mean mitotic count was 0.9/10 high-power fields. Only one tumour had multifocal mild nuclear atypia. Positive p16 was noted in 34 of 35 (97.2%) tumours. It was typically patchy, and was concentrated in areas immediately surrounding the necrosis. Distant from the necrosis, p16 positivity was seen predominantly in scattered/isolated cells. One tumour without any worrisome microscopic features showed diffuse p16 positivity throughout. Median follow-up was 55 months, and none of the patients experienced any recurrence. Conclusion p16 expression in benign uterine smooth muscle tumours with infarct-type necrosis is common. The staining is particularly concentrated adjacent to areas of necrosis. It is important to be aware of this potential pitfall when interpreting p16 expression. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
6. Clinical performance of the Roche Cobas 4800 HPV test for primary cervical cancer screening in a Chinese population.
- Author
-
Liu, Stephanie S., Chan, Karen K. L., Wei, Tina N., Tse, Ka Yu, Ngu, Siew F., Chu, Mandy M. Y., Lau, Lesley S. K., Cheung, Annie N. Y., and Ngan, Hextan Y. S.
- Subjects
- *
EARLY detection of cancer , *CHINESE people , *CERVICAL cancer , *PAPILLOMAVIRUSES , *VIRUS diseases , *PAPILLOMAVIRUS diseases - Abstract
High-risk human papillomavirus (HR-HPV) testing has become an increasing important strategy in primary cervical cancer screening in recent years. It warrants the evaluation of molecular-based HPV tests for accuracy and efficacy of screening. The performance of Roche Cobas 4800 HPV test was validated and compared with Digene Hybrid Capture 2 (HC2) high-risk HPV DNA test for primary screening in a large Chinese screening cohort. Of 6345 women screened, overall agreement between Cobas and HC2 was 92.23% (95% CI: 91.57–92.89). The inter-assay agreement was correlated with the severity of underlying biology, with an increasing concordance found in samples with more severe abnormalities. Most of the discordant samples had the test signal strength closer to the test limits of the detection than concordant samples, reflecting a low viral load and infection of a cluster of low-risk HPV in these samples. The Cobas test demonstrated significantly higher specificity in identifying CIN2+/CIN3+ cases than HC2 test (66.46% vs 43.67% and 65.42% vs 42.86%, p<0.001), with comparable sensitivity in clinical evaluation. Increased specificity of Cobas test would accent women having the highest risk of developing CIN2+, with the potential to reduce unnecessary colposcopy referral in a screening population. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
7. MicroRNA-135a-induced formation of CD133+ subpopulation with cancer stem cell properties in cervical cancer.
- Author
-
Leung, Carmen O N, Deng, Wen, Ye, Tian-Min, Ngan, Hextan Y S, Tsao, Sai Wah, Cheung, Annie N Y, Ziru, Niu, Yuen, Dominic C K, Pang, Ronald T K, and Yeung, William S B
- Subjects
- *
CANCER stem cells , *CERVICAL cancer , *EPITHELIAL cells , *CANCER cells - Abstract
Cancer stem cells (CSCs) play significant roles in tumor initiation. MicroRNA-135a (miR-135a) induced the formation of a CD133+ subpopulation from a human papillomavirus-immortalized cervical epithelial cell line. Compared with the CD133− cells, the CD133+ cells expressed higher levels of miR-135a and OCT4, exhibited significantly higher tumorsphere forming capacity and the time required for tumorsphere formation was shortened in the second generation. Serum induction suppressed the expression of CD133, OCT4 and miR-135a, but increased expression of involucrin in the miR-135a-induced CD133+ cells. The miR-135a-induced CD133+ cells were tumorigenic in a limiting dilution approach in vivo. The cells expressed significantly higher level of active β-catenin and OCT4 than the CD133− counterpart. Wnt3a enhanced the expression of OCT4 and CD133 in cervical cancer cells but failed to enhance CD133 transcription in normal cervical cells. Wnt3a stimulation also increased tumorsphere size and self-renewal of miR-135a-induced CD133+ subpopulation. Wnt/β-catenin inhibition suppressed tumorsphere formation while Wnt3a partially nullified the inhibitory effect. Taken together, miR-135a induced the formation of a subpopulation of cells with CSC properties both in vitro and in vivo and the Wnt/β-catenin signaling pathway is essential to maintain its tumorigenicity. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
8. Differential expression of estrogen receptor subtypes and variants in ovarian cancer: effects on cell invasion, proliferation and prognosis.
- Author
-
Chan, Karen K. L., Siu, Michelle K. Y., Yu-xin Jiang, Jing-jing Wang, Yan Wang, Leung, Thomas H. Y., Liu, Stephanie S., Cheung, Annie N. Y., Ngan, Hextan Y. S., Jiang, Yu-Xin, Wang, Jing-Jing, and Wang, Yan
- Subjects
- *
ESTROGEN receptors , *OVARIAN cancer , *CELL proliferation , *CANCER cell growth , *IMMUNOHISTOCHEMISTRY , *PROGNOSIS , *PROTEIN metabolism , *CANCER invasiveness , *CELL lines , *CELL physiology , *GENES , *OVARIAN tumors , *PROTEINS , *DIAGNOSIS - Abstract
Background: Due to the presence of both classical estrogen receptor (ERα) and another ER subtype (ERβ) in ovarian cancer, hormonal treatment is an attractive option. However, response to tamoxifen in ovarian cancer is modest. The presence of ERβ variants further complicated the issue. We have recently shown that specifically targeting ER subtypes using selective ER modulators showed opposing functions of ER subtypes on cell growth. In the present study, the clinical significance of ERα and ERβ variants (β1, β2 and β5) and the functional effects of ERβ2 and ERβ5 in ovarian cancer was investigated.Methods: ERα, ERβ1, ERβ2 and ERβ5 expression were evaluated by immunohistochemistry in 106 ovarian cancer tissues. The association between ERs expression and clinicopathological parameters or prognosis was analyzed. Ectopic expression of ERβ2 and ERβ5 followed by functional assays were performed in ovarian cancer cell lines in order to detect their effects on cell invasion and proliferation.Results: We found significantly higher nuclear (n)ERα and nERβ5 and lower cytoplasmic (c)ERα expression in advanced cancers. Significantly lower ERβ1 expression was also detected in high grade cancers. Significant loss of nERα and cERβ2 expression were observed in clear cell histological subtypes. Higher nERβ5 and lower cERβ5 expression were associated with serous/clear cell subtypes, poor disease-free and overall survival. Positive cERα and higher cERβ1 expression were significantly associated with better disease-free and overall survival. Furthermore, we found nERβ5 as an independent prognostic factor for overall survival. Functionally, overexpression of ERβ5 enhanced ovarian cancer cell migration, invasion and proliferation via FAK/c-Src activation whereas ERβ2 induced cell migration and invasion.Conclusions: Since tamoxifen binds to both ERα and ERβ1 which appear to bear opposing oncogenic roles, the histotypes-specific expression pattern of ERs indicates that personalized treatment for women based on ERs expression using selective estrogen receptor modulators may improve response rate. This study also suggests nERβ5 as a potential prognostic marker and therapeutic target in ovarian cancer. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
- View/download PDF
9. The elusive MAESTRO gene: Its human reproductive tissue-specific expression pattern.
- Author
-
Kenigsberg, Shlomit, Lima, Patricia D. A., Maghen, Leila, Wyse, Brandon A., Lackan, Chantal, Cheung, Annie N. Y., Tsang, Benjamin K., and Librach, Clifford L.
- Subjects
- *
GRANULOSA cells , *PATHOLOGICAL physiology , *ANATOMICAL organ diseases , *MALE reproductive organ diseases , *WESTERN immunoblotting , *GENETICS , *DIAGNOSIS - Abstract
The encoded transcript of the Maestro—Male-specific Transcription in the developing Reproductive Organs (MRO) gene exhibits sexual dimorphic expression during murine gonadal development. The gene has no homology to any known gene and its expression pattern, protein function or structure are still unknown. Previously, studying gene expression in human ovarian cumulus cells, we found increased expression of MRO in lean-type Polycystic Ovarian Syndrome (PCOS) subjects, as compared to controls. In this study, we examined the MRO splice variants and protein expression pattern in various human tissues and cells. We found a differential expression pattern of the MRO 5’-UTR region in luteinized granulosa-cumulus cells and in testicular tissues as compared to non-gonadal tissues. Our study also shows a punctate nuclear expression pattern and disperse cytoplasmic expression pattern of the MRO protein in human granulosa-cumulus cells and in testicular germ cells, which was later validated by western blotting. The tentative and unique features of the protein hampered our efforts to gain more insight about this elusive protein. A better understanding of the tissue-specific MRO isoforms expression patterns and the unique structure of the protein may provide important insights into the function of this gene and possibly to the pathophysiology of PCOS. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
10. The mitosis-specific marker phosphohistone-H3 ( PHH3) is an independent prognosticator in uterine smooth muscle tumours: an outcome-based study.
- Author
-
Chow, Kin‐Long, Tse, Ka‐Yu, Cheung, Ching‐Lung, Wong, Ka‐Wing, Cheung, Annie N Y, Wong, Richard W C, Chan, Alice N H, Yuen, Nancy W F, Ngan, Hextan Y S, and Ip, Philip P C
- Subjects
- *
IMMUNOHISTOCHEMISTRY , *MITOSIS , *UTERINE fibroids , *SMOOTH muscle tumors , *LEIOMYOSARCOMA - Abstract
Aims Accurate mitosis counting, which is important in the diagnosis of uterine smooth muscle tumours ( USMTs), is often difficult and subjective. The mitosis-specific immunohistochemical marker phosphohistone-H3 ( PHH3) has been shown to be diagnostically useful, but its expression, in relation to outcome, has not been thoroughly investigated. The aim of this study is to evaluate PHH3 as a diagnostic and prognostic marker in USMTs. Methods and results PHH3 expression was evaluated in 55 leiomyosarcomas ( LMSs), 26 smooth muscle tumours of uncertain malignant potential ( STUMPs), 18 leiomyomas with bizarre nuclei ( LBN), and 12 leiomyomas ( LMs). Scores were expressed as counts per 10 high-power fields ( HPFs). Median follow-up durations of patients with LMS, STUMP, LBN and LM were, respectively, 39, 78, 65.5 and 49.5 months. Twenty-eight patients with LMSs (50.9%) died, and two (7.7%) patients with STUMPs experienced recurrence. The median PHH3 scores for LMSs were significantly higher than those for other categories of tumour. A score of ≥29/10 HPFs was also independently associated with a poor outcome. To test whether the PHH3 score could distinguish between benign USMTs with atypical histology and those that were clinically malignant, two biological groups were further delineated. Patients in group 1 (18 LBNs and 24 STUMPs) all had an uneventful outcome, whereas patients in group 2 (two recurrent STUMPs and 32 LMSs) all had a recurrence or tumour-related death. Median PHH3 scores for the two groups were, respectively, 2/10 HPFs and 27/10 HPFs. A PHH3 score of ≥7/10 HPFs was highly associated with malignancy. Conclusion PHH3 is useful in evaluation of the biological behaviour of USMTs, and may serve as a prognostic indicator for LMSs. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
11. p21-Activated Kinases 1, 2 and 4 in Endometrial Cancers: Effects on Clinical Outcomes and Cell Proliferation.
- Author
-
Siu, Michelle K. Y., Kong, Daniel S. H., Ngai, Sheila Y. P., Chan, Hoi Yan, Jiang, Lili, Wong, Esther S. Y., Liu, Stephanie S., Chan, Karen K. L., Ngan, Hextan Y. S., and Cheung, Annie N. Y.
- Subjects
- *
TREATMENT of endometrial cancer , *P21 gene , *HEALTH outcome assessment , *CANCER cell proliferation , *CANCER invasiveness , *ENDOMETRIUM - Abstract
p21-activated kinases (Paks) are serine/threonine protein kinases involved in biological events linked to malignant tumor progression. In this study, expression of Pak1, p-Pak2 Ser20, Pak4, pPak4 Ser474 in 21 normal endometrium, 16 hyperplastic endometrium without atypia, 17 atypical complex hyperplasia and 67 endometrial cancers was assessed by immunohistochemistry and correlated with clinicopathological parameters. We also accessed the proliferative role and downstream targets of Pak1 in endometrial cancer. Pak1 was expressed in cytoplasm whereas Pak4 and p-Pak4 were expressed in both cytoplasm and nucleus of endometrial tissues. In normal endometrium, significantly higher Pak1 (P = 0.028) and cytoplasmic p-Pak2 (P = 0.048) expression was detected in proliferative endometrium than secretory endometrium. Pak1, cytoplasmic and nuclear Pak4 and nuclear p-Pak4 was significantly overexpressed in endometrial cancer when compared to atrophic endometrium (all P<0.05). Moreover, type I endometrioid carcinomas showed significantly higher Pak1 expression than type II non-endometrioid carcinomas (P<0.001). On the other hand, Pak1, Pak4 and p-Pak4 expression negatively correlated with histological grade (all P<0.05) while p-Pak2 and cytoplasmic Pak4 expression inversely correlated with myometrial invasion (all P<0.05). Furthermore, patients with endometrial cancers with lower cytoplasmic Pak4 expression showed poorer survival (P = 0.026). Multivariate analysis showed cytoplasmic Pak4 is an independent prognostic factor. Functionally, knockdown of Pak1, but not Pak4, in endometrial cancer cell line led to reduced cell proliferation along with reduced cyclin D1, estrogen receptor (ERα) and progestogen receptor (PR) expression. Significant correlation between Pak1 and PR expression was also detected in clinical samples. Our findings suggest that Pak1 and cytoplasmic p-Pak2 may promote cell proliferation in normal endometrium during menstral cycle. Pak1, cytoplasmic and nuclear Pak4 and nuclear p-Pak4 are involved in the pathogenesis of endometrial cancer especially in postmenopausal women. Pak1 promote endometrial cancer cell proliferation, particular in type I endometrioid carcinoma. Cytoplasmic Pak4 can be potential prognostic marker in endometrial cancer. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
12. Overexpression of Forkhead Box Protein M1 (FOXM1) in Ovarian Cancer Correlates with Poor Patient Survival and Contributes to Paclitaxel Resistance.
- Author
-
Zhao, Fung, Siu, Michelle K. Y., Jiang, LiLi, Tam, Kar Fai, Ngan, Hextan Y. S., Le, Xiao Feng, Wong, Oscar G. W., Wong, Esther S. Y., Gomes, Ana R., Bella, Laura, Khongkow, Pasarat, Lam, Eric W-F, and Cheung, Annie N. Y.
- Subjects
- *
OVARIAN cancer treatment , *FORKHEAD transcription factors , *GENE expression , *PACLITAXEL , *CARCINOGENESIS , *CYTOLOGY - Abstract
Aim: Deregulation of FOXM1 has been documented in various cancers. The aim of this study was to evaluate the role of FOXM1 in ovarian cancer tumorigenesis and paclitaxel resistance. Experimental Design: Expression of FOXM1 was examined in 119 clinical samples by immunohistochemistry and correlated with clinicopathological parameters. Effects of FOXM1 knockdown on ovarian cancer cell migration, invasion and mitotic catastrophe were also studied. qPCR and ChIP-qPCR were used to establish KIF2C as a novel FOXM1 target gene implicated in chemoresistance. Results: High nuclear FOXM1 expression in ovarian cancer patient samples was significantly associated with advanced stages (P = 0.035), shorter overall (P = 0.019) and disease-free (P = 0.014) survival. Multivariate analysis confirmed FOXM1 expression as an independent prognostic factor for ovarian cancer. FOXM1 knockdown significantly inhibited migration and invasion of ovarian cancer cells and enhanced paclitaxel-mediated cell death and mitotic catastrophe in a p53-independent manner. Bioinformatics analysis suggested a number of potential transcription targets of FOXM1. One of the potential targets, KIF2C, exhibited similar expression pattern to FOXM1 in chemosensitive and chemoresistant cells in response to paclitaxel treatment. FOXM1 could be detected at the promoter of KIF2C and FOXM1 silencing significantly down-regulated KIF2C. Conclusion: Our findings suggest that FOXM1 is associated with poor patient outcome and contributes to paclitaxel resistance by blocking mitotic catastrophe. KIF2C is identified as a novel FOXM1 transcriptional target that may be implicated in the acquisition of chemoresistance. FOXM1 should be further investigated as a potential prognostic marker and therapeutic target for ovarian cancer. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
13. Downregulation of the Gli Transcription Factors Regulator Kif7 Facilitates Cell Survival and Migration of Choriocarcinoma Cells.
- Author
-
Ho, Joanna, Du, Yanan, Wong, Oscar Gee-Wan, Siu, Michelle K. Y., Chan, Karen K. L., and Cheung, Annie N. Y.
- Subjects
- *
TRANSCRIPTION factors , *CELL migration , *CHORIOCARCINOMA , *CANCER cells , *CELLULAR signal transduction , *HEDGEHOG signaling proteins - Abstract
The kinesin protein Kif7 has been recognized as an integral component of hedgehog signalling. Aberrant activation of hedgehog signalling has been implicated in many human solid tumours. Gestational trophoblastic disease includes frankly malignant choriocarcinoma and potentially malignant hydatidiform mole. Here we investigated the hedgehog signalling components expression profiles in gestational trophoblastic disease. Downregulation of Gli1, Gli2, Gli3 and Kif7 was demonstrated in clinical samples of choriocarcinoma and hydatidiform moles as well as choriocarcinoma cell lines when compared with normal placentas. Ectopic expression of Kif7 in two choriocarcinoma cell lines JAR and JEG-3 led to a decrease in cell growth and increase in apoptosis demonstrated by MTT and TUNEL assays, respectively. Overexpression of Kif7 also led to suppressed cell migration through transwell assay. In contrast, knocking down Kif7 in HTR-8/SVneo, an immortalized trophoblast cell line, increased cell number over time and increased the migratory ability of the cells. Taken together, Kif7 may contribute to pathogenesis of gestational trophoblastic disease through enhancing survival and promoting dissemination of trophoblasts. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
14. AMPK Activators Suppress Cervical Cancer Cell Growth through Inhibition of DVL3 Mediated Wnt/β-Catenin Signaling Activity.
- Author
-
Kwan, H. T., Chan, David W., Cai, Patty C. H., Mak, Celia S. L., Yung, Mingo M. H., Leung, Thomas H. Y., Wong, Oscar G. W., Cheung, Annie N. Y., and Ngan, Hextan Y. S.
- Subjects
- *
CANCER cell growth , *DRUG monitoring , *CERVICAL cancer , *CARCINOGENESIS , *UBIQUITINATION , *PROTEIN synthesis - Abstract
Recent evidence has suggested that AMPK activators may be applied as therapeutic drugs in suppressing cancer cell growth. However, the molecular mechanism of their suppressive function in cancer cells is still unclear. Here we show that AMPK activators impair cervical cancer cell growth through the reduction of DVL3, a positive regulator in Wnt/β-catenin signaling and an oncogenic player in cervical cancer tumorigenesis. By western blot and immunohistochemical analyses, we demonstrated that DVL3 was frequently upregulated and significantly associated with elevated β-catenin (P = 0.009) and CyclinD1 (P = 0.009) expressions in cervical cancer. Enforced expression of DVL3 elevated β-catenin and augmented cervical cancer cell growth, verifying that DVL3-mediated Wnt/β-catenin activation is involved in cervical cancer oncogenesis. On the other aspect, we noted that the cervical cancer cell growth was remarkably suppressed by AMPK activators and such cell growth inhibition was in concomitant with the reduction of DVL3 protein level in dose- and time-dependent manners. Besides, impaired mTOR signaling activity also reduced DVL3 expression. In contrast, co-treatment with Compound C (AMPK inhibitor) could significantly abrogate metformin induced DVL3 reduction. In addition, co-treatment with AM114 or MG132 (proteosomal inhibitors) could partially restore DVL3 expression under the treatment of metformin. Further in vivo ubiquitination assay revealed that metformin could reduce DVL3 by ubiquitin/proteasomal degradation. To our knowledge, this is the first report showing the probable molecular mechanisms of that the AMPK activators suppress cervical cancer cell growth by impairing DVL3 protein synthesis via AMPK/mTOR signaling and/or partially promoting the proteasomal degradation of DVL3. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
15. SpliceArray Profiling of Breast Cancer Reveals a Novel Variant of NCOR2/SMRT That Is Associated with Tamoxifen Resistance and Control of ERα Transcriptional Activity.
- Author
-
Luduo Zhang, Chun Gong, Lau, Samantha L. Y., Nan Yang, Wong, Oscar G. W., Cheung, Annie N. Y., Tsang, Janice W. H., Chan, Kelvin Y. K., and Ui-Soon Khoo
- Subjects
- *
BREAST cancer , *TAMOXIFEN , *ANTINEOPLASTIC agents , *DRUG resistance in cancer cells , *GENE expression - Abstract
Gene expression profiling aimed at classifying and prognosing breast cancer has yielded signatures with little, if any, concordance. However, expression arrays used in these studies do not discriminate alternate RNA splice isoforms that vary widely in cancer and may resolve this problem. In this study, we profiled splice isoforms in a panel of tamoxifen-sensitive and -resistant cell lines, defining a novel variant (BQ323636.1) of the nuclear receptor corepressor 2 (NCOR2) that was associated with tamoxifen resistance. Overexpression of this variant in a tamoxifen-sensitive cell line induced its resistance to tamoxifen. We confirmed our initial findings from cell lines in 77 breast tumors from a Chinese cohort, where BQ323636.1 expression was higher in tamoxifen-resistant patients than tamoxifen-sensitive patients. For patients who were estrogen receptor (ER)-positive and had received tamoxifen treatment, higher BQ323636.1 expression level correlated with distant metastasis. High expression level of BQ323636.1 was found to be associated with poorer overall and disease-free survival for patients who had received tamoxifen treatment. Notably, higher BQ323636.1 versus NCOR2 wild-type ratio was also associated with negative ER and progesterone receptor (PR) status, and triple-negative status (ER-/PR-/ HER2- receptor status). Mechanistic investigations showed that under conditions of tamoxifen exposure, BQ323636.1 suppressed the transcriptional activity of ERα, exhibiting promoter-regulating functions. Our findings highlight a novel splice variant of the ERα corepressor NCOR2 as a candidate biomarker in breast cancer that not only predicts tamoxifen response but may be targeted to overcome tamoxifen resistance. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
16. Paradoxical Impact of Two Folate Receptors, FRα and RFC, in Ovarian Cancer: Effect on Cell Proliferation, Invasion and Clinical Outcome.
- Author
-
Siu, Michelle K. Y., Kong, Daniel S. H., Hoi Yan Chan, Wong, Esther S. Y., Ip, Philip P. C., LiLi Jiang, Ngan, Hextan Y. S., Xiao-Feng Le, and Cheung, Annie N. Y.
- Subjects
- *
FOLIC acid , *OVARIAN cancer , *CELL proliferation , *VITAMINS , *TUMOR growth , *CANCER - Abstract
Despite being an essential vitamin, folate has been implicated to enhance tumor growth, as evidenced by reports on overexpression of folate receptor alpha (FRα) in carcinomas. The role of another folate transporter, reduced folate carrier (RFC), is largely unknown. This study investigated the roles of folate, FRα and RFC in ovarian cancers. We demonstrated FRα mRNA and protein overexpression and reduced RFC expression in association with Fαa gene amplification and RFC promoter hypermethylation, respectively. FRα overexpression was associated with tumor progression while RFC expression incurred a favorable clinical outcome. Such reciprocal expression pattern was also observed in ovarian cancer cell lines. Folate was shown to promote cancer cell proliferation, migration and invasion in vitro, and down-regulate E-cadherin expression. This effect was blocked after either stable knockdown of FRα or ectopic overexpression of RFC. This hitherto unreported phenomenon suggests that, RFC can serve as a balancing partner of FRα and confer a protective effect in patients with high FRα-expressing ovarian carcinomas, as evidenced by their prolonged overall and disease-free survivals. In conclusion, we report on the paradoxical impact of FRα (putative oncogenic) and RFC (putative tumor suppressive) in human malignancies. FRα and RFC may potentially be explored as therapeutic target or prognostic marker respectively. We recommend caution and additional research on folate supplements in cancer patients. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
17. Increased Expression of PITX2 Transcription Factor Contributes to Ovarian Cancer Progression.
- Author
-
Fung, Frederic K. C., Chan, David W., Liu, Vincent W. S., Leung, Thomas H. Y., Cheung, Annie N. Y., and Ngan, Hextan Y. S.
- Subjects
- *
TRANSCRIPTION factors , *OVARIAN cancer , *EMBRYOLOGY , *CARCINOGENESIS , *CELL growth , *CELL migration , *CANCER invasiveness - Abstract
Background: Paired-like homeodomain 2 (PITX2) is a bicoid homeodomain transcription factor which plays an essential role in maintaining embryonic left-right asymmetry during vertebrate embryogenesis. However, emerging evidence suggests that the aberrant upregulation of PITX2 may be associated with tumor progression, yet the functional role that PITX2 plays in tumorigenesis remains unknown. Principal Findings: Using real-time quantitative RT-PCR (Q-PCR), Western blot and immunohistochemical (IHC) analyses, we demonstrated that PITX2 was frequently overexpressed in ovarian cancer samples and cell lines. Clinicopathological correlation showed that the upregulated PITX2 was significantly associated with high-grade (P = 0.023) and clear cell subtype (P = 0.011) using Q-PCR and high-grade (P,0.001) ovarian cancer by IHC analysis. Functionally, enforced expression of PITX2 could promote ovarian cancer cell proliferation, anchorage-independent growth ability, migration/invasion and tumor growth in xenograft model mice. Moreover, enforced expression of PITX2 elevated the cell cycle regulatory proteins such as Cyclin-D1 and C-myc. Conversely, RNAi mediated knockdown of PITX2 in PITX2-high expressing ovarian cancer cells had the opposite effect. Conclusion: Our findings suggest that the increased expression PITX2 is involved in ovarian cancer progression through promoting cell growth and cell migration/invasion. Thus, targeting PITX2 may serve as a potential therapeutic modality in the management of high-grade ovarian tumor. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
18. Human papillomavirus vaccine: What are women most concerned about?
- Author
-
Chan, Karen K. L., Kwan, Tracy T. C., Yao, Tzy-Jyun, Tam, Kar Fai, Cheung, Annie N. Y., and Ngan, Hextan Y. S.
- Subjects
- *
CANCER prevention , *CERVICAL cancer , *CHI-squared test , *DRUG side effects , *EPIDEMIOLOGY , *IMMUNIZATION , *INCOME , *QUESTIONNAIRES , *STATISTICAL sampling , *WOMEN , *HUMAN papillomavirus vaccines , *COST analysis , *DATA analysis , *MULTIPLE regression analysis , *SOCIAL attitudes , *INFORMATION needs , *CROSS-sectional method , *DATA analysis software - Abstract
Aim: This study aims to investigate the areas of concerns that women have regarding human papillomavirus (HPV) vaccination. Material and Methods: A cross-sectional questionnaire survey was conducted in a convenience sample of 1450 women attending outpatient family planning clinics in Hong Kong to assess women's concerns regarding HPV vaccination. The associations between each demographic characteristics and the importance of various issues concerning the vaccine, such as short and long-term side-effects, side-effect affecting appearance, number of women who have had it, effectiveness, effect duration and cost were explored using χ2 tests for comparison of proportions. Multiple binary logistic regression analysis was applied to further identify independent demographic characteristics which were significantly associated with each of these issues. Results: The top three factors that most women felt very important were vaccine effectiveness (45.4%), effect duration (44.0%) and long-term side-effects (43.7%). Education level significantly affected the degree of concerns in these areas (OR = 1.15, P < 0.001, 1.14, P < 0.001 and 1.09, P = 0.006, respectively) while income was significantly inversely associated with the importance of cost (OR = 0.92, P < 0.001) and effectiveness (OR = 0.95, P = 0.047). Conclusion: The above issues should be specifically addressed when vaccine information is given, bearing in mind the particular concerns in women with different socio-economic backgrounds. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
19. Overexpression of dedicator of cytokinesis I (Dock180) in ovarian cancer correlated with aggressive phenotype and poor patient survival.
- Author
-
Zhao, Fung, Siu, Michelle K Y, Jiang, LiLi, Tam, Kar Fai, Ngan, Hextan Y S, Le, Xiao-Feng, Wong, Oscar G W, Wong, Esther S Y, Chan, Hoi Yan, and Cheung, Annie N Y
- Subjects
- *
CYTOKINESIS , *OVARIAN cancer , *PHENOTYPES , *PROGNOSIS , *IMMUNOHISTOCHEMISTRY , *DIAGNOSTIC use of polymerase chain reaction , *WESTERN immunoblotting - Abstract
Zhao F, Siu M K Y, Jiang L L, Tam K F, Ngan H Y S, Le X-F, Wong O G W, Wong E S Y, Chan H Y & Cheung A N Y (2011) Histopathology 59, 1163-1172 Overexpression of dedicator of cytokinesis I (Dock180) in ovarian cancer correlated with aggressive phenotype and poor patient survival Aims: Dedicator of cytokinesis I (Dock180) is a novel guanine nucleotide exchange factor for Rho guanosine triphosphates (GTPases) important for cell migration. The aim of this study was to evaluate the role of Dock180 in ovarian carcinogenesis. Methods and results: Using immunohistochemistry, real-time polymerase chain reaction and Western blotting, overexpression of Dock180 RNA and protein was demonstrated in the nucleus and cytoplasm of ovarian cancer cell lines ( n = 5) and clinical samples of ovarian borderline tumours ( n = 21) and invasive cancers ( n = 108) when compared with ovarian epithelial cell lines ( n = 3) and benign cystadenomas ( n = 10) ( P < 0.05). High Dock180 cytoplasmic expression in ovarian cancer ( n = 108) was associated significantly with serous histological type, high-grade cancer and advanced stage ( P < 0.05), as well as poor overall and disease-free survival ( P = 0.004). Using multivariate progression analysis, high Dock180 cytoplasmic expression and advanced cancer stage were found to be independent prognostic factors for short overall survival and disease-free survival ( P < 0.05). Exogenous expression of Dock180 by transient transfection enhanced cancer cell migration and invasion, whereas knockdown of Dock180 by an siRNA approach retarded cancer cell migration and invasion in association with down-regulation of matrix metalloproteinase 2. Conclusions: Our findings suggest that Dock180 contributes to ovarian carcinogenesis and dissemination and is a potential prognostic marker and therapeutic target. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
20. Asia Oceania Guidelines for the Implementation of Programs for Cervical Cancer Prevention and Control.
- Author
-
Ngan, Hextan Y. S., Garland, Suzanne M., Bhatla, Neerja, Pagliusi, Sonia R., Chan, Karen K. L., Cheung, Annie N. Y., Tang-Yuan Chu, Domingo, Efren J., You Lin Qiao, Jong Sup Park, Eng Hseon Tay, and Supakarapongkul, Wisit
- Subjects
- *
CANCER prevention , *CERVICAL cancer , *CANCER in women , *CANCER patients , *GENITAL diseases , *HEALTH practitioners , *MEDICAL care , *PREVENTION - Abstract
This paper aims to provide evidence-based recommendations for health professionals, to develop a comprehensive cervical cancer program for a clinic, a community, or a country. Ensuring access to healthcare is the responsibility of all societies, and the Asia Oceania Research Organisation in Genital Infections and Neoplasia (AOGIN) is committed to working collaboratively with governments and health professionals to facilitate prevention programs, to protect girls and women from cervical cancer, a disease that globally affects 500,000 and kills nearly 300,000 women annually, just over half of whom are in the Asia Oceania region. We share the vision that a comprehensive program of vaccination, screening, and treatment should be made accessible to all girls and women in the world. The primary purpose of these guidelines is to provide information on scientific evidence on the different modalities and approaches of cervical cancer prevention programs, for high resource and low resource settings. The secondary purpose is to provide an overview of the current situation of cervical cancer control and prevention in various Asian Oceania countries: their views of an ideal program, identified obstacles, and suggestions to overcome them are discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
21. Wild Type and Mutant 2009 Pandemic Influenza A (H1N1) Viruses Cause More Severe Disease and Higher Mortality in Pregnant BALB/c Mice.
- Author
-
Kwok-Hung Chan, Zhang, Anna J. X., To, Kelvin K. W., Chan, Chris C. S., Poon, Vincent K. M., Kunyuan Guo, Fai Ng, Qi-Wei Zhang, Leung, Virtual H. C., Cheung, Annie N. Y., Lau, Candy C. Y., Woo, Patrick C. Y., Herman Tse, Wailan Wu, Honglin Chen, Bo-Jian Zheng, and Kwok-Yung Yuen
- Subjects
- *
H1N1 influenza , *PANDEMICS , *GENETIC mutation , *CELL lines , *HEMAGGLUTININ , *CYTOKINES , *GENETIC markers , *PREGNANCY complications , *REVERSE transcriptase polymerase chain reaction - Abstract
Background: Pregnant women infected by the pandemic influenza A (H1N1) 2009 virus had more severe disease and higher mortality but its pathogenesis is still unclear. Principal Findings: We showed that higher mortality, more severe pneumonitis, higher pulmonary viral load, lower peripheral blood T lymphocytes and antibody responses, higher levels of proinflammatory cytokines and chemokines, and worse fetal development occurred in pregnant mice than non-pregnant controls infected by either wild type (clinical isolate) or mouse-adapted mutant virus with D222G substitution in hemagglutinin. These disease-associated changes and the lower respiratory tract involvement were worse in pregnant mice challenged by mutant virus. Though human placental origin JEG-3 cell line could be infected and proinflammatory cytokines or chemokines were elevated in amniotic fluid of some mice, no placental or fetal involvement by virus were detected by culture, real-time reverse transcription polymerase chain reaction or histopathological changes. Dual immunofluorescent staining of viral nucleoprotein and type II alveolar cell marker SP-C protein suggested that the majority of infected alveolar epithelial cells were type II pneumocytes. Conclusion: The adverse effect of this pandemic virus on maternal and fetal outcome is largely related to the severe pulmonary disease and the indirect effect of inflammatory cytokine spillover into the systemic circulation. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
22. Hypermethylation of SOX2 Gene in Hydatidiform Mole and Choriocarcinoma.
- Author
-
Li, Albert S. M., Siu, Michelle K. Y., HuiJuan Zhang, Wong, Esther S. Y., Chan, Kelvin Y. K., Ngan, Hextan Y. S., and Cheung, Annie N. Y.
- Subjects
- *
TRANSCRIPTION factors , *STEM cells , *METHYLATION , *CHORIOCARCINOMA , *MESSENGER RNA , *HISTONE deacetylase - Abstract
This study investigated the expression and methylation profiles of SOX2, a stem cell--related transcription factor, in placentas and gestational trophoblastic disease. The methylation status of SOX2 promoter region in 55 hydatidiform moles, 4 choriocarcinoma, 23 first trimester, and 15 term placentas was evaluated by methylation-specific polymerase chain reaction. The methylated allele was found in 4.4% (1/23) of first trimester placentas, 26.7% (4/15) term placentas, and 56.4% (31/55) of hydatidiform moles and all choriocarcinoma samples and cell lines. A significant reduction in SOX2 messenger RNA expression was found in the hydatidiform moles (P 1/4 .027) when compared with that in the placentas. SOX2 messenger RNA expression was significantly correlated with SOX2 hypermethylation (P < .001). SOX2 expression was restored in choriocarcinoma cell lines following treatment to 5-Aza -2'-deoxycytidine and/or Trichostatin A, demethylation and histone deacetylase inhibitors, respectively, and the response was synergistic. Epigenetic mechanisms may play important role on the transcriptional regulation of SOX2 and contribute to pathogenesis of gestational trophoblastic disease. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
23. Nuclear HKII-P-p53 (Ser15) Interaction is a Prognostic Biomarker for Chemoresponsiveness and Glycolytic Regulation in Epithelial Ovarian Cancer.
- Author
-
Han, Chae Young, Patten, David A., Kim, Se Ik, Lim, Jung Jin, Chan, David W., Siu, Michelle K. Y., Han, Youngjin, Carmona, Euridice, Parks, Robin J., Lee, Cheol, Di, Li-Jun, Lu, Zhen, Chan, Karen K. L., Ku, Ja-Lok, Macdonald, Elizabeth A., Vanderhyden, Barbara C., Mes-Masson, Anne-Marie, Ngan, Hextan Y. S., Cheung, Annie N. Y., and Song, Yong Sang
- Subjects
- *
OVARIAN epithelial cancer , *PHOSPHOTRANSFERASES , *CELL lines , *GLYCOLYSIS - Abstract
Simple Summary: Hexokinase II (HKII) is a key glycolysis enzyme associated with tumorigenesis, but its molecular mechanism and pathophysiological role in chemoresistant ovarian cancer remain elusive. In this study, we delineate the novel mechanism showing that activated phosphorylated-p53 (P-p53 Ser15) is required for the regulation of HKII intracellular trafficking and metabolic regulation in chemosensitive ovarian cancer, but not in chemoresistant ovarian cancer harboring p53 mutation. We have observed that increased nuclear HKII-P-p53 (Ser15) interaction is likely associated with chemosensitivity and better survival outcomes in epithelial ovarian cell lines, human primary epithelial ovarian cancer cells, and tumor sections. Nuclear HKII-P-p53 (Ser15) interaction may function as a promising prognostic biomarker, enabling prediction of patients with poor prognosis for deciding better clinical strategies. In epithelial ovarian cancer (EOC), carboplatin/cisplatin-induced chemoresistance is a major hurdle to successful treatment. Aerobic glycolysis is a common characteristic of cancer. However, the role of glycolytic metabolism in chemoresistance and its impact on clinical outcomes in EOC are not clear. Here, we show a functional interaction between the key glycolytic enzyme hexokinase II (HKII) and activated P-p53 (Ser15) in the regulation of bioenergetics and chemosensitivity. Using translational approaches with proximity ligation assessment in cancer cells and human EOC tumor sections, we showed that nuclear HKII-P-p53 (Ser15) interaction is increased after chemotherapy, and functions as a determinant of chemoresponsiveness as a prognostic biomarker. We also demonstrated that p53 is required for the intracellular nuclear HKII trafficking in the control of glycolysis in EOC, associated with chemosensitivity. Mechanistically, cisplatin-induced P-p53 (Ser15) recruits HKII and apoptosis-inducing factor (AIF) in chemosensitive EOC cells, enabling their translocation from the mitochondria to the nucleus, eliciting AIF-induced apoptosis. Conversely, in p53-defective chemoresistant EOC cells, HKII and AIF are strongly bound in the mitochondria and, therefore, apoptosis is suppressed. Collectively, our findings implicate nuclear HKII-P-p53(Ser15) interaction in chemosensitivity and could provide an effective clinical strategy as a promising biomarker during platinum-based therapy. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
24. Association of ICAM3 Genetic Variant with Severe Acute Respiratory Syndrome.
- Author
-
Chan, Kelvin Y. K., Ching, Johannes C. Y., Xu, M. S., Cheung, Annie N. Y., Shea-Ping Yip, Yam, Loretta Y. C., Sik-To Lai, Chung-Ming Chu, Wong, Andrew T. Y., You-Qiang Song, Fang-Ping Huang, Wei Liu, Chung, P. H., Leung, G. M., Chow, Eudora Y. D., Chan, Eric Y. T., Chan, Jane C. K., Ngan, Hextan Y. S., Tam, Paul, and Li-Chong Chan
- Subjects
- *
CELL adhesion molecules , *T cells , *ADULT respiratory distress syndrome , *HUMAN genetic variation , *IR genes , *GENETIC polymorphisms , *CLINICAL trials , *DISEASE risk factors - Abstract
Genetic polymorphisms have been demonstrated to be associated with vulnerability to human infection. ICAM3, an intercellular adhesion molecule important for T cell activation, and FCER2 (CD23), an immune response gene, both located on chromosome 19p13.3, were investigated for host genetic susceptibility and association with clinical outcome. A case-control study based on 817 patients with confirmed severe acute respiratory syndrome (SARS), 307 health care worker control subjects, 290 outpatient control subjects, and 309 household control subjects unaffected by SARS from Hong Kong was conducted to test for genetic association. No significant association to susceptibility to SARS infection caused by the novel coronavirus (SARS-CoV) was found for the FCER2 and the ICAM3 single nucleotide polymorphisms. However, patients with SARS homozygous for ICAM3 Gly143 showed significant association with higher lactate dehydrogenase levels (P = .0067; odds ratio [OR], 4.31 [95% confidence interval {CI}, 1.37-13.56]) and lower total white blood cell counts (P = .022; OR, 0.30 [95% CI, 0.10-0.89]) on admission. These findings support the role of ICAM3 in the immunopathogenesis of SARS. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
25. Acrosome-specific gene AEP1: Identification, characterization and roles in spermatogenesis.
- Author
-
Luk, John M., Lee, Nikki P. Y., Shum, Cathy K., Lam, Brian Y., Siu, Annie F. M., Chi-Ming Che, Po-Chor Tam, Cheung, Annie N. Y., Yang, Z. M., Yi-Nan Lin, Matzuk, Martin M., Kai-Fai Lee, and Yeung, William S. B.
- Subjects
- *
SPERMATOGENESIS , *SPERMATOZOA , *GENES , *PEPTIDES , *GLYCOSYLATION , *PHOSPHORYLATION , *FLOW cytometry , *SPECIES - Abstract
Spermatogenesis is a tightly regulated process leading to the development of spermatozoa. To elucidate the molecular spermatogenic mechanisms, we identified an acrosome-specific gene AEP1 in spermatids, which is located in rat chromosome 17p14 with a transcript size of 3,091 bp encoding a signal peptide, zinc finger-like motif, coiled-coil region, several predicted glycosylation and phosphorylation sites. Northern blot and RT-PCR analyses revealed the restricted expression of AEP1 to the testis only. In postnatal rat testes, AEP1 mRNA became detectable from postnatal 25 dpp (round spermatids) and onwards. By using in situ hybridization (ISH) and flow cytometry-fluorescent ISH, only the haploid spermatids yielded the positive AEP1 signal. Immunohistochemistry showed that AEP1 was expressed in the acrosomal cap of late-staged germ cells in rat testis, and co-localized with the acrosomal marker, peanut agglutinin. The spatial expression of AEP1 immunoreactivity in testis was conserved among diverse mammalian species (rat, pig, monkey, human). To further study its roles in spermatogenesis, we showed AEP1 and β-actin was associated together in complex by co-immunoprecipitation in adult germ cells and by immunofluorescence assay in isolated spermatozoon. In human testes diagnosed with hypospermatogenesis, lower expression of AEP1 was observed, whereas there was no detectable signal in undescended testes. In short, AEP1 is an evolutionary-conserved acrosome-specific gene and likely functions in acrosome-cap formation. J. Cell. Physiol. 209: 755–766, 2006. © 2006 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
26. Age-period-cohort analysis of cervical cancer incidence in Hong Kong from 1972 to 2001 using maximum likelihood and Bayesian methods.
- Author
-
Leung, Gabriel M, Woo, Pauline P S, McGhee, Sarah M, Cheung, Annie N Y, Fan, Susan, Mang, Oscar, Thach, Thuan Q, and Ngan, Hextan Y S
- Subjects
- *
WOMEN'S health , *CERVICAL cancer , *PUBLIC health , *CANCER diagnosis , *PREGNANT women - Abstract
Objective: To examine the secular effects of opportunistic screening for cervical cancer in a rich, developed community where most other such populations have long adopted organised screening. Design, setting, and participants: The analysis was based on 15 140 cases of invasive cervical cancer from 1972 to 2001. The effects of chronological age, time period, and birth cohort were decomposed using both maximum likelihood and Bayesian methods. Results: The overall age adjusted incidence decreased from 24.9 in 1972-74 to 9.5 per 100,000 in 1999-2001, in a log-linear fashion, yielding an average annual reduction of 4.0% (p<0.001) during! the 30 year period. There were two second order and thus identifiable changes: (1) around the mid-1920s cohort curve representing an age-period interaction masquerading as a cohort change that denotes the first availability of Pap testing during the 1960s concentrated among women in their 40s; (2) a hook around the calendar years 1982-83 when cervical cytology became a standard screening test for pregnant women. Conclusions: Hong Kong's cervical cancer rates have declined since Pap tests first became available in the 1960s, most probably because of increasing population coverage over time and in successive generations in a haphazard fashion and punctuated by the systematic introduction of routine cytology as part of antenatal care in the 1980s. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
27. Homozygous L-SIGN (CLEC4M) plays a protective role in SARS coronavirus infection.
- Author
-
Chan, Vera S. F., Chan, Kelvin Y. K., Chen, Yongxiong, Poon, Leo L. M, Cheung, Annie N. Y., Bojian Zheng, Kwok-Hung Chan, Mak, William, Ngan, Hextan Y. S., Xiaoning Xu, Screaton, Gavin, Tam, Paul K. H., Austyn, Jonathan M., Li-Chong Chan, Shea-Ping Yip, Peiris, Malik, Ui-Soon Khoo, and Lin, Chen-Lung S.
- Subjects
- *
SARS disease , *CORONAVIRUS diseases , *GENETIC polymorphisms , *CELLS , *COMMUNICABLE diseases , *GENETICS - Abstract
Severe acute respiratory syndrome (SARS) is caused by infection of a previously undescribed coronavirus (CoV). L-SIGN, encoded by CLEC4M (also known as CD209L), is a SARS-CoV binding receptor that has polymorphism in its extracellular neck region encoded by the tandem repeat domain in exon 4. Our genetic risk association study shows that individuals homozygous for CLEC4M tandem repeats are less susceptible to SARS infection. L-SIGN is expressed in both non-SARS and SARS-CoV–infected lung. Compared with cells heterozygous for L-SIGN, cells homozygous for L-SIGN show higher binding capacity for SARS-CoV, higher proteasome-dependent viral degradation and a lower capacity for trans infection. Thus, homozygosity for L-SIGN plays a protective role during SARS infection. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
28. Mitomycin chemotherapeutic pleurodesis to palliate malignant pleural effusions secondary to gynecological cancer.
- Author
-
Cheng, Danny, Chan, Yik-Ming, Ng, Tong-Yow, Cheung, Annie N. Y., Ngan, Hextan Y. S., and Wong, Ling-Chui
- Subjects
- *
EXUDATES & transudates , *BLEOMYCIN - Abstract
Examines the efficacy of mitomycin pleurodesis on the treatment of end stage malignant effusion in the United States. Association of diffuse alveolar injury with bleomycin pleurodesis; Decline of prolonged hospital stay and treatment time; Symptomatic improvement of cervical cancer.
- Published
- 1999
- Full Text
- View/download PDF
29. Hexokinase 2 Regulates Ovarian Cancer Cell Migration, Invasion and Stemness via FAK/ERK1/2/MMP9/NANOG/SOX9 Signaling Cascades.
- Author
-
Siu, Michelle K. Y., Jiang, Yu-Xin, Wang, Jing-Jing, Leung, Thomas H. Y., Han, Chae Young, Tsang, Benjamin K., Cheung, Annie N. Y., Ngan, Hextan Y. S., and Chan, Karen K. L.
- Subjects
- *
DEOXY sugars , *CANCER , *CANCER invasiveness , *CELL lines , *CELLULAR signal transduction , *FIBROBLASTS , *GENE expression , *GLYCOLYSIS , *INTERLEUKINS , *LACTATES , *METASTASIS , *OVARIAN tumors , *PROTEOLYTIC enzymes , *TRANSCRIPTION factors , *TRANSFERASES , *TUMOR classification , *TUMOR grading , *THERAPEUTICS - Abstract
Metabolic reprogramming is a common phenomenon in cancers. Thus, glycolytic enzymes could be exploited to selectively target cancer cells in cancer therapy. Hexokinase 2 (HK2) converts glucose to glucose-6-phosphate, the first committed step in glucose metabolism. Here, we demonstrated that HK2 was overexpressed in ovarian cancer and displayed significantly higher expression in ascites and metastatic foci. HK2 expression was significantly associated with advanced stage and high-grade cancers, and was an independent prognostic factor. Functionally, knockdown of HK2 in ovarian cancer cell lines and ascites-derived tumor cells hindered lactate production, cell migration and invasion, and cell stemness properties, along with reduced FAK/ERK1/2 activation and metastasis- and stemness-related genes. 2-DG, a glycolysis inhibitor, retarded cell migration and invasion and reduced stemness properties. Inversely, overexpression of HK2 promoted cell migration and invasion through the FAK/ERK1/2/MMP9 pathway, and enhanced stemness properties via the FAK/ERK1/2/NANOG/SOX9 cascade. HK2 abrogation impeded in vivo tumor growth and dissemination. Notably, ovarian cancer-associated fibroblast-derived IL-6 contributed to its up-regulation. In conclusion, HK2, which is regulated by the tumor microenvironment, controls lactate production and contributes to ovarian cancer metastasis and stemness regulation via FAK/ERK1/2 signaling pathway-mediated MMP9/NANOG/SOX9 expression. HK2 could be a potential prognostic marker and therapeutic target for ovarian cancer. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
30. Selected aspects of ovarian pathology.
- Author
-
Robboy, Stanley J., Campbell, Ian G., Oliva, Esther, Cheung, Annie N. Y., Proietto, Anthony, and Russell, Peter
- Subjects
- *
OVARIAN diseases , *PATHOLOGY , *TUMORS , *MOLECULAR genetics , *CANCER , *OVARIES - Abstract
Focuses on selected aspects of ovarian pathology. Clinical features of serous borderline tumors of the ovary and their peritoneal perils; Precursors of epithelial ovarian cancer; Molecular genetic characteristics of serous and mucinous ovarian cystadenomas; Unusual features and differential diagnosis of sex cord stromal tumors of the ovary.
- Published
- 2004
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.