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Expression of mitochondrial non-coding RNAs (ncRNAs) is modulated by high risk human papillomavirus (HPV) oncogenes.

Villota C, Campos A, Vidaurre S, Oliveira-Cruz L, Boccardo E, Burzio VA, Varas M, Villegas J, Villa LL, Valenzuela PD, Socías M, Roberts S, Burzio LO - J. Biol. Chem. (2012)

Bottom Line: Transduction of HFK with both E6 and E7 is sufficient to induce expression of SncmtRNA-2.Moreover, E2 oncogene is involved in down-regulation of the ASncmtRNAs.Knockdown of E2 in immortalized cells reestablishes in a reversible manner the expression of the ASncmtRNAs, suggesting that endogenous cellular factors(s) could play functions analogous to E2 during non-HPV-induced oncogenesis.

View Article: PubMed Central - PubMed

Affiliation: Andes Biotechnologies SA, Fundación Ciencia para la Vida, Zanartu 1482 7782272, Chile. claudio.villota@gmail.com

ABSTRACT
The study of RNA and DNA oncogenic viruses has proved invaluable in the discovery of key cellular pathways that are rendered dysfunctional during cancer progression. An example is high risk human papillomavirus (HPV), the etiological agent of cervical cancer. The role of HPV oncogenes in cellular immortalization and transformation has been extensively investigated. We reported the differential expression of a family of human mitochondrial non-coding RNAs (ncRNAs) between normal and cancer cells. Normal cells express a sense mitochondrial ncRNA (SncmtRNA) that seems to be required for cell proliferation and two antisense transcripts (ASncmtRNAs). In contrast, the ASncmtRNAs are down-regulated in cancer cells. To shed some light on the mechanisms that trigger down-regulation of the ASncmtRNAs, we studied human keratinocytes (HFK) immortalized with HPV. Here we show that immortalization of HFK with HPV-16 or 18 causes down-regulation of the ASncmtRNAs and induces the expression of a new sense transcript named SncmtRNA-2. Transduction of HFK with both E6 and E7 is sufficient to induce expression of SncmtRNA-2. Moreover, E2 oncogene is involved in down-regulation of the ASncmtRNAs. Knockdown of E2 in immortalized cells reestablishes in a reversible manner the expression of the ASncmtRNAs, suggesting that endogenous cellular factors(s) could play functions analogous to E2 during non-HPV-induced oncogenesis.

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Immortalization of HFK with HPV induces down-regulation of the ASncmtRNAs.A, expression of the SncmtRNA and the ASncmtRNAs in normal HFK or HFK immortalized with HPV-16 (HFK698 cells) or 18 (18Nco cells) was analyzed by ISH. The ASncmtRNAs are down-regulated in the immortalized cells as well as in the corresponding tumorigenic cell lines SiHa (HPV-16-transformed) and HeLa (HPV-18-transformed). Magnification was ×40. B, expression of SncmtRNA-1 (S), ASncmtRNA-1 (AS-1), and ASncmtRNA-2 (AS-2) in the different cell lines was evaluated by RT-PCR amplification. The internal control used was 18S rRNA. M, 100-bp ladder. C, the relative intensity of the bands corresponding to the different non-coding mitochondrial RNAs was determined by densitometry and normalized against the intensity of the 150-bp amplicon from 18S rRNA.
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Figure 1: Immortalization of HFK with HPV induces down-regulation of the ASncmtRNAs.A, expression of the SncmtRNA and the ASncmtRNAs in normal HFK or HFK immortalized with HPV-16 (HFK698 cells) or 18 (18Nco cells) was analyzed by ISH. The ASncmtRNAs are down-regulated in the immortalized cells as well as in the corresponding tumorigenic cell lines SiHa (HPV-16-transformed) and HeLa (HPV-18-transformed). Magnification was ×40. B, expression of SncmtRNA-1 (S), ASncmtRNA-1 (AS-1), and ASncmtRNA-2 (AS-2) in the different cell lines was evaluated by RT-PCR amplification. The internal control used was 18S rRNA. M, 100-bp ladder. C, the relative intensity of the bands corresponding to the different non-coding mitochondrial RNAs was determined by densitometry and normalized against the intensity of the 150-bp amplicon from 18S rRNA.

Mentions: As seen in Fig. 1, and in accordance with our previous results (9, 10), normal HFK express the SncmtRNA-1 and ASncmtRNAs. In contrast, SiHa and HeLa cells, cervical cancer cell lines that arose from natural infection by HPV-16 and 18, respectively, express the SncmtRNA-1 and down-regulate expression of the ASncmtRNAs (Fig. 1A). Similarly, HFK immortalized with the complete genome of HPV-16 (HFK698 cells) (14) or HPV-18 (18Nco cells) (15) also express the SncmtRNA-1 and down-regulate the ASncmtRNAs (Fig. 1A).


Expression of mitochondrial non-coding RNAs (ncRNAs) is modulated by high risk human papillomavirus (HPV) oncogenes.

Villota C, Campos A, Vidaurre S, Oliveira-Cruz L, Boccardo E, Burzio VA, Varas M, Villegas J, Villa LL, Valenzuela PD, Socías M, Roberts S, Burzio LO - J. Biol. Chem. (2012)

Immortalization of HFK with HPV induces down-regulation of the ASncmtRNAs.A, expression of the SncmtRNA and the ASncmtRNAs in normal HFK or HFK immortalized with HPV-16 (HFK698 cells) or 18 (18Nco cells) was analyzed by ISH. The ASncmtRNAs are down-regulated in the immortalized cells as well as in the corresponding tumorigenic cell lines SiHa (HPV-16-transformed) and HeLa (HPV-18-transformed). Magnification was ×40. B, expression of SncmtRNA-1 (S), ASncmtRNA-1 (AS-1), and ASncmtRNA-2 (AS-2) in the different cell lines was evaluated by RT-PCR amplification. The internal control used was 18S rRNA. M, 100-bp ladder. C, the relative intensity of the bands corresponding to the different non-coding mitochondrial RNAs was determined by densitometry and normalized against the intensity of the 150-bp amplicon from 18S rRNA.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3375551&req=5

Figure 1: Immortalization of HFK with HPV induces down-regulation of the ASncmtRNAs.A, expression of the SncmtRNA and the ASncmtRNAs in normal HFK or HFK immortalized with HPV-16 (HFK698 cells) or 18 (18Nco cells) was analyzed by ISH. The ASncmtRNAs are down-regulated in the immortalized cells as well as in the corresponding tumorigenic cell lines SiHa (HPV-16-transformed) and HeLa (HPV-18-transformed). Magnification was ×40. B, expression of SncmtRNA-1 (S), ASncmtRNA-1 (AS-1), and ASncmtRNA-2 (AS-2) in the different cell lines was evaluated by RT-PCR amplification. The internal control used was 18S rRNA. M, 100-bp ladder. C, the relative intensity of the bands corresponding to the different non-coding mitochondrial RNAs was determined by densitometry and normalized against the intensity of the 150-bp amplicon from 18S rRNA.
Mentions: As seen in Fig. 1, and in accordance with our previous results (9, 10), normal HFK express the SncmtRNA-1 and ASncmtRNAs. In contrast, SiHa and HeLa cells, cervical cancer cell lines that arose from natural infection by HPV-16 and 18, respectively, express the SncmtRNA-1 and down-regulate expression of the ASncmtRNAs (Fig. 1A). Similarly, HFK immortalized with the complete genome of HPV-16 (HFK698 cells) (14) or HPV-18 (18Nco cells) (15) also express the SncmtRNA-1 and down-regulate the ASncmtRNAs (Fig. 1A).

Bottom Line: Transduction of HFK with both E6 and E7 is sufficient to induce expression of SncmtRNA-2.Moreover, E2 oncogene is involved in down-regulation of the ASncmtRNAs.Knockdown of E2 in immortalized cells reestablishes in a reversible manner the expression of the ASncmtRNAs, suggesting that endogenous cellular factors(s) could play functions analogous to E2 during non-HPV-induced oncogenesis.

View Article: PubMed Central - PubMed

Affiliation: Andes Biotechnologies SA, Fundación Ciencia para la Vida, Zanartu 1482 7782272, Chile. claudio.villota@gmail.com

ABSTRACT
The study of RNA and DNA oncogenic viruses has proved invaluable in the discovery of key cellular pathways that are rendered dysfunctional during cancer progression. An example is high risk human papillomavirus (HPV), the etiological agent of cervical cancer. The role of HPV oncogenes in cellular immortalization and transformation has been extensively investigated. We reported the differential expression of a family of human mitochondrial non-coding RNAs (ncRNAs) between normal and cancer cells. Normal cells express a sense mitochondrial ncRNA (SncmtRNA) that seems to be required for cell proliferation and two antisense transcripts (ASncmtRNAs). In contrast, the ASncmtRNAs are down-regulated in cancer cells. To shed some light on the mechanisms that trigger down-regulation of the ASncmtRNAs, we studied human keratinocytes (HFK) immortalized with HPV. Here we show that immortalization of HFK with HPV-16 or 18 causes down-regulation of the ASncmtRNAs and induces the expression of a new sense transcript named SncmtRNA-2. Transduction of HFK with both E6 and E7 is sufficient to induce expression of SncmtRNA-2. Moreover, E2 oncogene is involved in down-regulation of the ASncmtRNAs. Knockdown of E2 in immortalized cells reestablishes in a reversible manner the expression of the ASncmtRNAs, suggesting that endogenous cellular factors(s) could play functions analogous to E2 during non-HPV-induced oncogenesis.

Show MeSH
Related in: MedlinePlus