Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To identify cellular genes that may be involved in human papillomavirus (HPV)-mediated immortalization mRNA differential display analysis was performed on preimmortal and subsequent immortal stages of four human keratinocyte cell lines transformed by HPV type 16 or 18 DNA. This yielded a cDNA fragment encoding the transcription factor GATA-3 that was strongly reduced in intensity in all immortal stages of the four cell lines. A marked reduction in both GATA-3 mRNA and protein expression in HPV-immortalized cell lines was confirmed by reverse transcriptase-polymerase chain reaction, Western blot analysis, and immunohistochemistry and was also shown to be apparent in cervical carcinoma cell lines. Immunohistochemical analysis of cervical tissue specimens showed a clear nuclear staining for GATA-3 in normal cervical squamous epithelium (n = 14) and all cervical intraepithelial neoplasia (CIN) I (n = 6) and CIN II lesions (n = 2). In contrast, 11% (1 of 9) of CIN III lesions and 67% (8 of 12) of cervical squamous cell carcinomas revealed a complete absence of GATA-3 immunostaining. Hence, complete down-regulation of GATA-3 expression represents a rather late event during cervical carcinogenesis. Whether GATA-3 down-regulation is etiologically involved in HPV-mediated immortalization and cervical carcinogenesis remains to be examined.
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PMID:Down-regulation of GATA-3 expression during human papillomavirus-mediated immortalization and cervical carcinogenesis. 1205 98

The human papillomavirus (HPV) plays an important role in the progression of cervical carcinoma. High-risk (HR) HPV types have been mainly identified in cytologic high-grade squamous intraepithelial lesions (HSILs) and histologic invasive carcinoma of the cervix. We examined cervical swabs of patients with abnormal Papanicolaou (Pap) smears, diagnosed as low-grade squamous intraepithelial lesions (LSILs) including atypical squamous cells of uncertain significance or HSILs. Low-risk (LR) HPV and HR-HPV types were identified by the Digene Hybrid Capture II test. Two-dimensional (2D) gel electrophoresis was used to specify the physical state of HPV DNA sequences. Expression of E6/E7 messenger RNA (mRNA) transcripts was analyzed by reverse transcriptase-polymerase chain reaction. Histopathologic results were correlated to the patients' physical status and HPV DNA mRNA transcripts. Pap smears with HPV infections of LR and HR types were correlated to the degree of squamous intraepithelial lesions (SILs). Comparing the physical states of HPV DNA sequences with the expression of HPV E6/E7 mRNA transcripts, all types were identified only as extrachromosomal in benign cervical smears, cervical intraepithelial neoplasia (CIN) I and II. HPV16 showed all physical states in CIN III/carcinoma in situ (CIS), whereas HPV18 only existed in mixed and integrated forms. HPV31/33/52b/58 appeared in all stages of lesions most commonly in extrachromosomal form; in integrated form, they were present only in CIN III/CIS. Although integration of some HR-HPV types is not always necessary for progression of SILs, the above-mentioned method is useful to analyze the physical state of HPV DNA sequences and predict the progression of SILs.
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PMID:Human papillomavirus DNA integration and messenger RNA transcription in cervical low- and high-risk squamous intraepithelial lesions in Austrian women. 1758 15

This study was designed to investigate whether there is a correlation between the down-regulation of microRNA-218 (miR-218) and the presence of human papillomavirus (HPV) infection in the pathogenesis of cervical cancer. The participants comprised 78 women with cervical intraepithelial neoplasia (CIN); 22 (28.2%) had CIN 1, 27 (34.6%) had CIN 2 and 29 (37.2%) had CIN 3. MiR-218 expression was determined by reverse transcriptase polymerase chain reaction and HPV genotypes in tissue specimens were identified with a microarray test kit. The findings showed that miR-218 levels in patients with high-risk HPV infection were lower than in those infected with low-risk or intermediate-risk HPV, or in those who were HPV-free. MiR-218 levels in patients with high-risk CIN were lower than in those with low-risk CIN. We concluded that infection with high-risk HPV lowered the expression of miR-218 and that down-regulation of miR-218 was involved in the pathogenesis of cervical cancer.
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PMID:High-risk human papillomavirus reduces the expression of microRNA-218 in women with cervical intraepithelial neoplasia. 2130 87