Peter C. K. Leung

Prof. Peter C. K. Leung

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Research Focus & Metrics

Academic Career Length

51Years (1976-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 June 2009 in New England Journal of Medicine
Verified
Journal Article
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SSSohrab P. Shah
Sohrab P. Shah
MKMartin Köbel
Martin Köbel
JSJanine Senz
Janine Senz
RMRyan D. Morin
Ryan D. Morin
BCBlaise A. Clarke
Blaise A. Clarke
DHDavid G. Huntsman
David G. Huntsman
Granulosa-cell tumors (GCTs) are the most common type of malignant ovarian sex cord–stromal tumor (SCST). The pathogenesis of these tumors is unknown. Moreover, their histopathological diagnosis can be challenging, and there is no curative treatment beyond surgery. We analyzed four adult-type GCTs using whole-transcriptome paired-end RNA sequencing. We identified putative GCT-specific mutations that were present in at least three of these samples but were absent from the transcriptomes of 11 epithelial ovarian tumors, published human genomes, and databases of single-nucleotide polymorphisms. We confirmed these variants by direct sequencing of complementary DNA and genomic DNA. We then analyzed additional tumors and matched normal genomic DNA, using a combination of direct sequencing, analyses of restriction-fragment–length polymorphisms, and TaqMan assays. All four index GCTs had a missense point mutation, 402C→G (C134W), in FOXL2, a gene encoding a transcription factor known to be critical for granulosa-cell development. The FOXL2 mutation was present in 86 of 89 additional adult-type GCTs (97%), in 3 of 14 thecomas (21%), and in 1 of 10 juvenile-type GCTs (10%). The mutation was absent in 49 SCSTs of other types and in 329 unrelated ovarian or breast tumors. Whole-transcriptome sequencing of four GCTs identified a single, recurrent somatic mutation (402C→G) in FOXL2 that was present in almost all morphologically identified adult-type GCTs. Mutant FOXL2 is a potential driver in the pathogenesis of adult-type GCTs.

1 April 2001 in Endocrine Reviews
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Journal Article
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NANelly Auersperg
Nelly Auersperg
AWAlice Sze-Tsai Wong
Alice Sze-Tsai Wong
KCKyung-Chul Choi
Kyung-Chul Choi
SKSung Keun Kang
Sung Keun Kang
PLPeter C. K. Leung
Peter C. K. Leung
The epithelial ovarian carcinomas, which make up more than 85% of human ovarian cancer, arise in the ovarian surface epithelium (OSE). The etiology and early events in the progression of these carcinomas are among the least understood of all major human malignancies because there are no appropriate animal models, and because methods to culture OSE have become available only recently. The objective of this article is to review the cellular and molecular mechanisms that underlie the control of normal and neoplastic OSE cell growth, differentiation, and expression of indicators of neoplastic progression. We begin with a brief discussion of the development of OSE, from embryonic to the adult. The pathological and genetic changes of OSE during neoplastic progression are next summarized. The histological characteristics of OSE cells in culture are also described. Finally, the potential involvement of hormones, growth factors, and cytokines is discussed in terms of their contribution to our understanding of the physiology of normal OSE and ovarian cancer development.

13 April 2012 in Diabetes
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Journal Article
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GDGuo-Lian Ding
Guo-Lian Ding
FWFang-Fang Wang
Fang-Fang Wang
JSJing Shu
Jing Shu
STShen Tian
Shen Tian
YJYing Jiang
Ying Jiang
HHHe-Feng Huang
He-Feng Huang
Gestational diabetes mellitus (GDM) has been shown to be associated with high risk of diabetes in offspring. However, the mechanisms involved and the possibilities of transgenerational transmission are still unclear. We intercrossed male and female adult control and first-generation offspring of GDM (F1-GDM) mice to obtain the second-generation (F2) offspring in four groups: C♂-C♀, C♂-GDM♀, GDM♂-C♀, and GDM♂-GDM♀. We found that birth weight significantly increased in F2 offspring through the paternal line with impaired glucose tolerance (IGT). Regardless of birth from F1-GDM with or without IGT, high risk of IGT appeared as early as 3 weeks in F2 offspring and progressed through both parental lineages, especial the paternal line. IGT in male offspring was more obvious than that in females, with parental characteristics and sex-specific transmission. In both F1 and F2 offspring of GDM, the expression of imprinted genes Igf2 and H19 was downregulated in pancreatic islets, caused by abnormal methylation status of the differentially methylated region, which may be one of the mechanisms for impaired islet ultrastructure and function. Furthermore, altered Igf2 and H19 gene expression was found in sperm of adult F1-GDM, regardless of the presence of IGT, indicating that changes of epigenetics in germ cells contributed to transgenerational transmission.

1 April 2005 in Endocrine Reviews
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Journal Article
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CCChi Keung Cheng
Chi Keung Cheng
PLPeter C. K. Leung
Peter C. K. Leung
In human beings, two forms of GnRH, termed GnRH-I and GnRH-II, encoded by separate genes have been identified. Although these hormones share comparable cDNA and genomic structures, their tissue distribution and regulation of gene expression are significantly dissimilar. The actions of GnRH are mediated by the GnRH receptor, which belongs to a member of the rhodopsin-like G protein-coupled receptor superfamily. However, to date, only one conventional GnRH receptor subtype (type I GnRH receptor) uniquely lacking a carboxyl-terminal tail has been found in the human body. Studies on the transcriptional regulation of the human GnRH receptor gene have indicated that tissue-specific gene expression is mediated by differential promoter usage in various cell types. Functionally, there is growing evidence showing that both GnRH-I and GnRH-II are potentially important autocrine and/or paracrine regulators in some extrapituitary compartments. Recent cloning of a second GnRH receptor subtype (type II GnRH receptor) in nonhuman primates revealed that it is structurally and functionally distinct from the mammalian type I receptor. However, the human type II receptor gene homolog carries a frameshift and a premature stop codon, suggesting that a full-length type II receptor does not exist in humans.

26 October 2016 in Human Reproduction Update
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Journal Article
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HCHsun-Ming Chang
Hsun-Ming Chang
JQJie Qiao
Jie Qiao
PLPeter C. K. Leung
Peter C. K. Leung
Initially identified for their capability to induce heterotopic bone formation, bone morphogenetic proteins (BMPs) are multifunctional growth factors that belong to the transforming growth factor β superfamily. Using cellular and molecular genetic approaches, recent studies have implicated intra-ovarian BMPs as potent regulators of ovarian follicular function. The bi-directional communication of oocytes and the surrounding somatic cells is mandatory for normal follicle development and oocyte maturation. This review summarizes the current knowledge on the physiological role and molecular determinants of these ovarian regulatory factors within the human germline-somatic regulatory loop. The regulation of ovarian function remains poorly characterized in humans because, while the fundamental process of follicular development and oocyte maturation is highly similar across species, most information on the regulation of ovarian function is obtained from studies using rodent models. Thus, this review focuses on the studies that used human biological materials to gain knowledge about human ovarian biology and disorders and to develop strategies for preventing, diagnosing and treating these abnormalities. Relevant English-language publications describing the roles of BMPs or growth differentiation factors (GDFs) in human ovarian biology and phenotypes were comprehensively searched using PubMed and the Google Scholar database. The publications included those published since the initial identification of BMPs in the mammalian ovary in 1999 through July 2016. Studies using human biological materials have revealed the expression of BMPs, GDFs and their putative receptors as well as their molecular signaling in the fundamental cells (oocyte, cumulus/granulosa cells (GCs) and theca/stroma cells) of the ovarian follicles throughout follicle development. With the availability of recombinant human BMPs/GDFs and the development of immortalized human cell lines, functional studies have demonstrated the physiological role of intra-ovarian BMPs/GDFs in all aspects of ovarian functions, from follicle development to steroidogenesis, cell–cell communication, oocyte maturation, ovulation and luteal function. Furthermore, there is crosstalk between these potent ovarian regulators and the endocrine signaling system. Dysregulation or naturally occurring mutations within the BMP system may lead to several female reproductive diseases. The latest development of recombinant BMPs, synthetic BMP inhibitors, gene therapy and tools for BMP-ligand sequestration has made the BMP pathway a potential therapeutic target in certain human fertility disorders; however, further clinical trials are needed. Recent studies have indicated that GDF8 is an intra-ovarian factor that may play a novel role in regulating ovarian functions in the human ovary. Intra-ovarian BMPs/GDFs are critical regulators of folliculogenesis and human ovarian functions. Any dysregulation or variations in these ligands or their receptors may affect the related intracellular signaling and influence ovarian functions, which accounts for several reproductive pathologies and infertility. Understanding the normal and pathological roles of intra-ovarian BMPs/GDFs, especially as related to GC functions and follicular fluid levels, will inform innovative approaches to fertility regulation and improve the diagnosis and treatment of ovarian disorders.

11 February 2020 in Human Reproduction Update
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Journal Article
Closed access
YZYu Zhang
Yu Zhang
CZChao Zhang
Chao Zhang
JSJing Shu
Jing Shu
JGJing Guo
Jing Guo
HCHsun-Ming Chang
Hsun-Ming Chang
HHHe-Feng Huang
He-Feng Huang
BACKGROUND: Despite great advances in assisted reproductive technology, poor ovarian response (POR) is still considered as one of the most challenging tasks in reproductive medicine.OBJECTIVE AND RATIONALE: The aim of this systemic review is to evaluate the role of different adjuvant treatment strategies on the probability of pregnancy achievement in poor responders undergoing IVF. Randomized controlled trials (RCTs) comparing 10 adjuvant treatments [testosterone, dehydroepiandrosterone (DHEA), letrozole, recombinant LH, recombinant hCG, oestradiol, clomiphene citrate, progesterone, growth hormone (GH) and coenzyme Q10 (CoQ10)] were included.SEARCH METHODS: Relevant studies published in the English language were comprehensively selected using PubMed, Embase and the Cochrane Central Register of Controlled Trials (CENTRAL) until 11 July 2018. We included studies that investigated various adjuvant agents, including androgen and androgen-modulating agents, oestrogen, progesterone, clomiphene citrate, GH and CoQ10, during IVF treatment and reported subsequent pregnancy outcomes. The administration of GnRH analogs and gonadotrophins without adjuvant treatment was set as the control. We measured study quality based on the methodology and categories listed in the Cochrane Collaboration Handbook. This review protocol was registered with PROSPERO (CRD42018086217).OUTCOMES: Of the 1124 studies initially identified, 46 trials reporting on 6312 women were included in this systematic review, while 19 trials defining POR using the Bologna criteria reporting 2677 women were included in the network meta-analysis. Compared with controls, DHEA and CoQ10 treatments resulted in a significantly higher chance of clinical pregnancy [odds ratio (OR) 2.46, 95% CI 1.16 to 5.23; 2.22, 1.08–4.58, respectively]. With regard to the number of retrieved oocytes, HCG, oestradiol and GH treatments had the highest number of oocytes retrieved [weighted mean difference (WMD) 2.08, 0.72 to 3.44; 2.02, 0.23 to 3.81; 1.72, 0.98 to 2.46, compared with controls, respectively]. With regard to the number of embryos transferred, testosterone and GH treatment led to the highest number of embryos transferred (WMD 0.72, 0.11 to 1.33; 0.67, 0.43 to 0.92; compared with controls, respectively). Moreover, GH resulted in the highest oestradiol level on the HCG day (WMD 797.63, 466.45 to 1128.81, compared with controls). Clomiphene citrate, letrozole and GH groups used the lowest dosages of gonadotrophins for ovarian stimulation (WMD 1760.00, −2890.55 to −629.45; −1110.17, −1753.37 to −466.96; −875.91, −1433.29 to −282.52; compared with controls, respectively). CoQ10 led to the lowest global cancelation rate (OR 0.33, 0.15 to 0.74, compared with controls).WIDER IMPLICATIONS: For patients with POR, controlled ovarian stimulation protocols using adjuvant treatment with DHEA, CoQ10 and GH showed better clinical outcomes in terms of achieving pregnancy, and a lower dosage of gonadotrophin required for ovulation induction. Furthermore, high-level RCT studies using uniform standards for POR need to be incorporated into future meta-analyses.