Establishment of two immortalized nasopharyngeal epithelial cell lines using SV40 large T and HPV16E6/E7 viral oncogenes

Tsao, Sai Wah; Wang, Xianghong; Liu, Yu; Cheung, Yuk Chun; Feng, Huichen; Zheng, Zhong; Wong, Natalie; Yuen, Po Wing; Lo, Angela Kwok Fung; Wong, Yong Chuan; Huang, Dolly P.

doi:10.1016/s0167-4889(02)00208-2

Cited by 170 publications

(151 citation statements)

References 19 publications

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“…The effect of LMP1 on RASSF1A expression was first observed in an immortalized nasopharyngeal epithelial cell line (NP69), which has been previously shown to be highly sensitive to the transformation action of LMP1 (Tsao et al, 2002b). Western blotting analysis showed that RASSF1A expression was downregulated in NP69 cells stably expressing LMP1 when compared with the parental cell line (NP69) (Figure 1a).…”

Section: Lmp1 Downregulates Rassf1a Expressionmentioning

confidence: 87%

“…Reconstitution of RASSF1A expression in a NPC cell line, C666-1, induced loss of viability, growth suppression, diminished invasiveness and anchorage-independence growth properties (Chow et al, 2004). A lower expression level of RASSF1A was detected in an immortalized nasopharyngeal epithelial cell line expressing LMP1 (Tsao et al, 2002b), which prompted us to investigate if LMP1 may regulate RASSF1A expression in cells.…”

Section: Introductionmentioning

confidence: 99%

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Latent membrane protein 1 suppresses RASSF1A expression, disrupts microtubule structures and induces chromosomal aberrations in human epithelial cells

et al. 2006

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Epstein-Barr virus (EBV) infection is closely associatedwith nasopharyngeal carcinoma (NPC) and can be detected in early premalignant lesions of nasopharyngeal epithelium. The latent membrane protein 1 (LMP1) is an oncoprotein encoded by the EBV and is believed to play a role in transforming premalignant nasopharyngeal epithelial cells into cancer cells. RASSF1A is a tumorsuppressor gene commonly inactivated in many types of human cancer including NPC. In this study, we report a novel function of LMP1, in down-regulating RASSF1A expression in human epithelial cells. Downregulation of RASSF1A expression by LMP1 is dependent on the activation of intracellular signaling of NF-jB involving the C-terminal activating regions (CTARs) of LMP1. LMP1 expression also suppresses the transcriptional activity of the RASSF1A core promoter. RASSF1A stabilizes microtubules and regulates mitotic events. Aberrant mitotic spindles and chromosome aberrations are reported phenotypes in RASSF1A inactivated cells. In this study, we observed that LMP1 expression in human epithelial cells could induce aberrant mitotic spindles, disorganized interphase microtubules and aneuploidy. LMP1 expression could also suppress microtubule dynamics as exemplified by tracking movements of the growing tips of microtubules in live cells by transfecting EGFP-tagged EB1 into cells. The aberrant mitotic spindles and interphase microtubule organization induced by LMP1 could be rescued by transfecting RASSF1A expression plasmid into cells. Downregulation of RASS-F1A expression by LMP1 may facilitate its role in transformation of premalignant nasopharyngeal epithelial cells into cancer cells.

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Section: Lmp1 Downregulates Rassf1a Expressionmentioning

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Latent membrane protein 1 suppresses RASSF1A expression, disrupts microtubule structures and induces chromosomal aberrations in human epithelial cells

et al. 2006

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“…In this study, we also analysed four normal epithelial cell lines, immortalized by SV40 T-antigen (NP69, NE3) (Tsao et al, 2002), or a hybrid of adenovirus 12 and SV40 virus (RHEK-1) or HPV-E6/E7 (NE1). These cell lines are good premalignant model systems for studying the mechanism of multi-step pathogenesis of carcinomas.…”

Section: Discussionmentioning

confidence: 99%

Functional epigenetics identifies a protocadherin PCDH10 as a candidate tumor suppressor for nasopharyngeal, esophageal and multiple other carcinomas with frequent methylation

Ying

Seng³

et al. 2005

Oncogene

243

288

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Protocadherins constitute the largest subgroup in the cadherin superfamily of cell adhesion molecules. Their major functions are poorly understood, although some are implicated in nervous system development. As tumorspecific promoter methylation is a marker for tumor suppressor genes (TSG), we searched for epigenetically inactivated TSGs using methylation-subtraction combined with pharmacologic demethylation, and identified the PCDH10 CpG island as a methylated sequence in nasopharyngeal carcinoma (NPC). PCDH10 is broadly expressed in all normal adult and fetal tissues including the epithelia, though at different levels. It resides at 4q28.3 -a region with hemizygous deletion detected by array-CGH in NPC cell lines; however, PCDH10 itself is not located within the deletion. In contrast, its transcriptional silencing and promoter methylation were frequently detected in multiple carcinoma cell lines in a biallelic way, including 12/12 nasopharyngeal, 13/16 esophageal, 3/4 breast, 5/5 colorectal, 3/4 cervical, 2/5 lung and 2/8 hepatocellular carcinoma cell lines, but not in any immortalized normal epithelial cell line. Aberrant methylation was further frequently detected in multiple primary carcinomas (82% in NPC, 42-51% for other carcinomas), but not normal tissues. The transcriptional silencing of PCDH10 could be reversed by pharmacologic demethylation with 5-aza-2 0 -deoxycytidine or genetic demethylation with double knockout of DNMT1 and DNMT3B, indicating a direct epigenetic mechanism. Ectopic expression of PCDH10 strongly suppressed tumor cell growth, migration, invasion and colony formation. Although the epigenetic and genetic disruptions of several classical cadherins as TSGs have been well documented in tumors, this is the first report that a widely expressed protocadherin can also function as a TSG that is frequently inactivated epigenetically in multiple carcinomas.

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“…Total RNAs were from the nonmalignant nasopharyngeal epithelial (NPE) cell line, NP69; 9 and from the NPC cell lines of TW01, HONE1 and SUNE1. Complementary DNAs (cDNAs) were constructed from the RNA, and RT-PCR was carried out using specific 20-mer primers designed for RP genes MRPL3, RPL3, RPL7a/surf3, RPL9, RPL10, RPL12, RPL18, RPL21, RPL23a, RPL26, RPL27, RPL27a, RPL29, RPL30, RPL35a, RPL37a, RPL38 and RPL41.…”

Section: Cell Lines and Rt-pcrmentioning

confidence: 99%

Differential expression of a subset of ribosomal protein genes in cell lines derived from human nasopharyngeal epithelium

Sim

Ang

et al. 2009

J Hum Genet

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Extraribosomal functions of human ribosomal proteins (RPs) include the regulation of cellular growth and differentiation, and are inferred from studies that linked congenital disorders and cancer to the deregulated expression of RP genes. We have previously shown the upregulation and downregulation of RP genes in tumors of colorectal and nasopharyngeal carcinomas (NPCs), respectively. Herein, we show that a subset of RP genes for the large ribosomal subunit is differentially expressed among cell lines derived from the human nasopharyngeal epithelium. Three such genes (RPL27, RPL37a and RPL41) were found to be significantly downregulated in all cell lines derived from NPC tissues compared with a nonmalignant nasopharyngeal epithelial cell line. The expression of RPL37a and RPL41 genes in human nasopharyngeal tissues has not been reported previously. Our findings support earlier suspicions on the existence of NPC-associated RP genes, and indicate their importance in human nasopharyngeal organogenesis. Keywords: differential expression; human cell lines; nasopharyngeal epithelium; NPC; RPL; RPL27; RPL37a; RPL41 INTRODUCTIONProducts of ribosomal protein (RP) genes are essential for cellular protein biosynthesis. Besides this, studies have also linked them to human congenital disorders and cancers. For instance, RPS4 has been implicated in Turner's syndrome, 1 and the mutant RPS19 was found in individuals with Diamond-Blackfan anemia. 2 In colorectal carcinoma, the overexpressions of RPS3, 3 RPS19 4 and RPL7a 5 have been reported. RPL23, a tumor metastasis-related gene, was found to induce high invasiveness of a human lung adenocarcinoma cell line. 6 In our previous study, 33 RP genes were overexpressed in tumors of colorectal carcinoma relative to their normal controls. 7 We have also recently identified two RP genes (namely RPS27 and RPS26) to be downregulated in nasopharyngeal carcinoma (NPC) tumors compared with a normal control. 8 Despite the increasing number of cancer-associated RP genes identified thus far, the full repertoire of RP genes linked to human cancers remains unclear. In this study, 18 RP genes encoding proteins for large ribosomal subunits were tested on cell lines derived from NPC tissues and the normal nasopharyngeal epithelium. This effort was aimed at identifying nasopharyngeal-associated RP genes.

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Establishment of two immortalized nasopharyngeal epithelial cell lines using SV40 large T and HPV16E6/E7 viral oncogenes

Cited by 170 publications

References 19 publications

Latent membrane protein 1 suppresses RASSF1A expression, disrupts microtubule structures and induces chromosomal aberrations in human epithelial cells

Latent membrane protein 1 suppresses RASSF1A expression, disrupts microtubule structures and induces chromosomal aberrations in human epithelial cells

Functional epigenetics identifies a protocadherin PCDH10 as a candidate tumor suppressor for nasopharyngeal, esophageal and multiple other carcinomas with frequent methylation

Differential expression of a subset of ribosomal protein genes in cell lines derived from human nasopharyngeal epithelium

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