Analysis of expression and structure of the TSG101 gene in cervical cancer cells.
Human papillomavirus (HPV)-mediated transformation of human epithelial cells has been recognized as a multi-step process in which additional unknown factors and (epi)genetic events are required. The tumor susceptibility gene 101 (TSG101) was discovered in mouse NIH3T3 fibroblast cells as a gene whose functional knockout leads to transformation. TSG101 protein is involved in a variety of important biological functions, such as ubiquitination, transcriptional regulation, endosomal trafficking, virus budding, proliferation and cell survival. It is suggested that TSG101 is an important factor for maintaining cellular homeostasis and that perturbation of TSG101 functions leads to cell transformation. Interestingly, a recent report showed up- or down-regulation of TSG101 in several human malignancies. At present, the role of TSG101 in cervical tumorigenesis is unexplained. TSG101 expression in tumors, where carcinogenesis is connected with viral infection, and a mechanism of TSG101 expression regulation in cancer cells are also unknown. The aim of our study was to estimate the TSG101 mRNA and protein level in cervical cancer and non-tumor epithelial cells. We also analyzed the TSG101 coding and promoter sequence using the PCR-SSCP technique and methylation pattern of the TSG101 promoter. Our real-time PCR and Western blot analysis showed decreased TSG101 mRNA and protein level in cervical cancer tissue in comparison to normal (non-tumor) HPV(-) and HPV16(+) epithelial cells. Our results suggest that TSG101 down-regulation in cervical cancer cells is not regulated by genetic or epigenetic events. However, we detected novel single nucleotide polymorphisms in the promoter of this gene.
Broniarczyk
J
J
Adam Mickiewicz University, Institute of Experimental Biology, Department of Molecular Virology, 61-614 Poznan, Poland. justekbr@amu.edu.pl
Olejnik-Schmidt
A K
AK
Luczak
M W
MW
Schmidt
M T
MT
Dabrowski
M
M
Józefiak
A
A
Kedzia
W
W
Kwasniewska
A
A
Gozdzicka-Józefiak
A
A
D000328:Adult; D000368:Aged; D000818:Animals; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D056827:Endosomal Sorting Complexes Required for Transport / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D052162:Human papillomavirus 16 / Q000235:genetics; D006801:Humans; D051379:Mice; D008875:Middle Aged; D041681:NIH 3T3 Cells; D020641:Polymorphism, Single Nucleotide; D018807:Polymorphism, Single-Stranded Conformational; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D002583:Uterine Cervical Neoplasms / Q000235:genetics* / Q000821:virology; D055815:Young Adult; D000099177:Tsg101 Protein
D004268:DNA-Binding Proteins; D056827:Endosomal Sorting Complexes Required for Transport; D014157:Transcription Factors; D000099177:Tsg101 Protein