Reduced expression of AMPK-β1 during tumor progression enhances the oncogenic capacity of advanced ovarian cancer.

AMP-activated protein kinase (AMPK) is a key energy sensor that is involved in regulating cell metabolism. Our previous study revealed that the subunits of the heterotimeric AMPK enzyme are diversely expressed during ovarian cancer progression. However, the impact of the variable expression of these AMPK subunits in ovarian cancer oncogenesis remains obscure.

Physiological β-catenin signaling controls self-renewal networks and generation of stem-like cells from nasopharyngeal carcinoma.

Background: A few reports suggested that low levels of Wnt signaling might drive cell reprogramming, but these studies could not establish a clear relationship between Wnt signaling and self-renewal networks. There are ongoing debates as to whether and how the Wnt/β-catenin signaling is involved in the control of pluripotency gene networks. Additionally, whether physiological β-catenin signaling generates stem-like cells through interactions with other pathways is as yet unclear.

LTBP-2 confers pleiotropic suppression and promotes dormancy in a growth factor permissive microenvironment in nasopharyngeal carcinoma.

This study identified LTBP-2 as a pleiotropic tumor suppressor in nasopharyngeal carcinoma, which safeguards against critical malignant behaviors of tumor cells. LTBP-2 expression was significantly decreased or lost in up to 100% of NPC cell lines (7/7) and 80% of biopsies (24/30). Promoter hypermethylation was found to be involved in LTBP-2 silencing.

Epigenetic alteration of the metallothionein 1E gene in human endometrial carcinomas.

Aberrant expression of metallothioneins (MTs) has been observed in several human tumors. In our microarray analysis, MT-1E was found to have much lower expression in endometrial cancer cells as compared with other types of cancer cells generated from the cervix, ovary or prostate. The result was confirmed by quantitative RT-PCR analysis of the MT-1E levels in individual cancer cells.

Semi-quantitative fluorescent PCR analysis identifies PRKAA1 on chromosome 5 as a potential candidate cancer gene of cervical cancer.

Objective: Comparative genomic hybridization has frequently detected amplification of chromosome 5p in cervical cancer, but candidate cancer genes within the region are rarely known. Therefore, we pursued to identify potential candidate gene related to cervical cancer development.

Methods: A series of 128 cervical tumor samples were examined by semi-quantitative fluorescent differential PCR for copy number changes on three candidate genes (PRKAA1, CTNND2 and POLS) mapped to chromosome 5p and one gene (ERBIN) mapped to chromosome 5q12.

Differential expression of insulin-like growth factor binding protein 1 and ferritin light polypeptide in gestational trophoblastic neoplasia: combined cDNA suppression subtractive hybridization and microarray study.

Background: Hydatidiform mole (HM), the most common type of gestational trophoblastic diseases, can be considered as placenta with abnormal chromosome composition with potential of malignant transformation. Few biologic markers can predict subsequent development of persistent gestational trophoblastic neoplasia (GTN) requiring chemotherapy.

Methods: Suppression subtractive hybridization (SSH) combined with cDNA microarray was used to compare the differential expression pattern of HM that spontaneously regressed and that subsequently developed metastatic GTN.

Single nucleotide polymorphism of pi-class glutathione s-transferase and susceptibility to endometrial carcinoma.

Purpose: Endometrial carcinoma is the most common gynecologic cancer in developed countries. Prolonged unopposed estrogen exposure has been identified as the major risk factor. The pi-class glutathione S-transferase (GSTP1) is a phase II metabolic enzyme that is important in the detoxification of a wide range of electrophiles including carcinogenic steroid-hormone intermediates generated through oxidative metabolism.

Promoter methylation and differential expression of pi-class glutathione S-transferase in endometrial carcinoma.

Pi-class glutathione S-transferase (GSTP1), located on chromosome 11q13, codes for a phase II metabolic enzyme that detoxifies reactive electrophilic intermediates. The protein also interacts with steroid hormones in the human body. The role of GSTP1 in endometrial carcinoma has not been reported.

Epigenetic and genetic alterations of p33ING1b in ovarian cancer.

p33ING1b is a candidate tumor suppressor gene and a nuclear protein. We investigated whether genetic and epigenetic mechanisms affect p33ING1b expression in ovarian cancer thus contributing toward its pathogenesis. A total of 111 ovarian cancers collected from Beijing and Hong Kong were used for this study.

Mcl-1 expression in gestational trophoblastic disease correlates with clinical outcome: a differential expression study.

Background: Hydatidiform moles (HMs) are abnormal pregnancies with a propensity for developing persistent disease in the form of gestational trophoblastic neoplasia (GTN), which requires chemotherapy. In previous studies, the authors demonstrated that low apoptotic activity was correlated with the progression of HM to GTN, and they hypothesized that some apoptosis-related genes may determine this progression.

Methods: The differential expression of apoptotic genes in HMs that subsequently developed into GTN was compared with the same expression in HMs that spontaneously regressed using a human apoptosis array; then, the expression was evaluated with real-time quantitative polymerase chain reaction analysis and immunohistochemistry using 54 clinical samples from patients with HMs who had follow-up data available.

Promoter hypermethylation of multiple genes in hydatidiform mole and choriocarcinoma.

The methylation status of genes in hydatidiform mole and choriocarcinoma and its significance is relatively unexplored. We investigated the methylation status of the promoter regions of six genes, p16, HIC-1, TIMP3, GSTP1, death-associated protein kinase (DAPK), and E-cadherin in 54 hydatidiform moles, five choriocarcinomas, and 10 first trimester placenta by methylation-specific polymerase chain reaction (PCR). Immunohistochemical expression of p16, TIMP3, and E-cadherin, and quantitative real-time RT-PCR of p16 was also performed.

p73 expression is associated with the cellular radiosensitivity in cervical cancer after radiotherapy.

Apoptosis is one of the causes of cell death in cervical cancer following radiotherapy. By studying the gene expression profile with cDNA apoptotic array, the p73 gene was found overexpressed in radiosensitive cervical cancers when compared with radioresistant ones. To investigate the role of the p73 gene in relation to clinical assessment of radiosensitivity in cervical cancer based on the findings of residual tumor cells in cervical biopsies after completion of radiotherapy, we studied the protein expression of p73 in 59 cervical cancers after radiotherapy and 68 normal cervices using immunohistochemistry.

Metastatic trophoblastic disease after an initial diagnosis of partial hydatidiform mole: genotyping and chromosome in situ hybridization analysis.

Background: Hydatidiform mole (HM) is classified into partial (PHM) and complete (CHM) subtypes according to histopathologic and genetic criteria. Traditionally, it is believed that PHM carries a better prognosis and rarely develops metastasis. However, making a distinction between PHM and CHM using histologic criteria alone may be difficult.

Analysis of gestational trophoblastic disease by genotyping and chromosome in situ hybridization.

Hydatidiform mole is classified into partial and complete subtypes according to histopathological and genetic criteria. Distinction between the two by histology alone may be difficult. Genetically, a complete mole is diploid without maternal contribution, whereas a partial mole is triploid with a maternal chromosome complement.

Detection of mitochondrial DNA mutations in gestational trophoblastic disease.

Mitochondrial DNA (mtDNA) mutations have been implicated in a wide range of human disease. However, its role in gestational trophoblastic disease remains unclear. In this study, the entire mitochondrial genome of 10 hydatidiform moles (HM) and one choriocarcinoma were examined by automated DNA sequencing after amplification by polymerase chain reaction.