Bovine seminal-ribonuclease (BS-RNase) is a member of the 'ribonucleases with special biological actions' family since it possesses specific anti-tumour, anti-spermatogenic and embryotoxic activities and exerts an immunosuppressive effect on T lymphocytes. In previous studies it was demonstrated that BS-RNase induced apoptosis in proliferating, malignant and normal cells and that telomerase activity loss also caused apoptotic death in neoplastic cells. Since an obvious relationship between cell proliferation and telomerase activity exists, the aim of this work was to study if the pro-apoptotic cytotoxic action exerted by BS-RNase on proliferating malignant cells (HT29) and proliferating normal cells (PHA-stimulated lymphocytes) could be linked to a possible BS-RNase effect on telomerase activity. In BS-RNase-treated HT29 cells (Na-butyrate-differentiated or not) and human lymphocytes (proliferating or not), we investigated cell vitality (MTT method) and morphology (SEM), BS-RNase localization (immunofluorescence), telomerase activity (TRAP-ELISA method), hTR mRNA expression (RT-PCR), and hTERT levels (Western blot). While no BS-RNase effect was detectable on not proliferating cells, a clear relationship was noticed between the diminished number of vital elements of both proliferating cell populations after treatment (48 h and 72 h for HT29 and PHA-stimulated lymphocytes, respectively) with 50 mu g/ml BS-RNase and the decrease of their telomerase activity. At the same time, we found that hTR levels, the RNA subunit of telomerase, in proliferation-inhibited BS-RNase-treated cells were diminished. Moreover, by immunofluorescence technique, we detected BS-RNase in the HT29 cell nucleolus after 3-h treatment. Therefore, as hTR has been recently proven to co-fractionate with nucleoli, we hypothesize that a BS-RNase direct action on the telomerase hTR subunit could be a possible mechanism of action by which BS-RNase exerts its pro-apoptotic effects only on proliferating cells.

Bovine seminal-ribonuclease (BS-RNase) is a member of the 'ribonucleases with special biological actions' family since it possesses specific anti-tumour, anti-spermatogenic and embryotoxic activities and exerts an immunosuppressive effect on T lymphocytes. In previous studies it was demonstrated that BS-RNase induced apoptosis in proliferating, malignant and normal cells and that telomerase activity loss also caused apoptotic death in neoplastic cells. Since an obvious relationship between cell proliferation and telomerase activity exists, the aim of this work was to study if the pro-apoptotic cytotoxic action exerted by BS-RNase on proliferating malignant cells (HT29) and proliferating normal cells (PHA-stimulated lymphocytes) could be linked to a possible BS-RNase effect on telomerase activity. In BS-RNasetreated HT29 cells (Na-butyrate-differentiated or not) and human lymphocytes (proliferating or not), we investigated cell vitality (MTT method) and morphology (SEM), BS-RNase localization (immunofluorescence), telomerase activity (TRAP-ELISA method), hTR mRNA expression (RT-PCR), and hTERT levels (Western blot). While no BS-RNase effect was detectable on not proliferating cells, a clear relationship was noticed between the diminished number of vital elements of both proliferating cell populations after treatment (48 h and 72 h for HT29 and PHA-stimulated lymphocytes, respectively) with 50 μg/ml BS-RNase and the decrease of their telomerase activity. At the same time, we found that hTR levels, the RNA subunit of telomerase, in proliferation-inhibited BS-RNasetreated cells were diminished. Moreover, by immunofluorescence technique, we detected BS-RNase in the HT29 cell nucleolus after 3-h treatment. Therefore, as hTR has been recently proven to co-fractionate with nucleoli, we hypothesize that a BS-RNase direct action on the telomerase hTR subunit could be a possible mechanism of action by which BS-RNase exerts its pro-apoptotic effects only on proliferating cells.

Bovine seminal ribonuclease is cytotoxic for both malignant and normal telomerase-positive cells

VIOLA, Maria;LIBRA, Massimo;SINATRA, Fulvia;PEZZINO, FRANCA MARIA;TRAVALI, Salvatore
2005-01-01

Abstract

Bovine seminal-ribonuclease (BS-RNase) is a member of the 'ribonucleases with special biological actions' family since it possesses specific anti-tumour, anti-spermatogenic and embryotoxic activities and exerts an immunosuppressive effect on T lymphocytes. In previous studies it was demonstrated that BS-RNase induced apoptosis in proliferating, malignant and normal cells and that telomerase activity loss also caused apoptotic death in neoplastic cells. Since an obvious relationship between cell proliferation and telomerase activity exists, the aim of this work was to study if the pro-apoptotic cytotoxic action exerted by BS-RNase on proliferating malignant cells (HT29) and proliferating normal cells (PHA-stimulated lymphocytes) could be linked to a possible BS-RNase effect on telomerase activity. In BS-RNase-treated HT29 cells (Na-butyrate-differentiated or not) and human lymphocytes (proliferating or not), we investigated cell vitality (MTT method) and morphology (SEM), BS-RNase localization (immunofluorescence), telomerase activity (TRAP-ELISA method), hTR mRNA expression (RT-PCR), and hTERT levels (Western blot). While no BS-RNase effect was detectable on not proliferating cells, a clear relationship was noticed between the diminished number of vital elements of both proliferating cell populations after treatment (48 h and 72 h for HT29 and PHA-stimulated lymphocytes, respectively) with 50 mu g/ml BS-RNase and the decrease of their telomerase activity. At the same time, we found that hTR levels, the RNA subunit of telomerase, in proliferation-inhibited BS-RNase-treated cells were diminished. Moreover, by immunofluorescence technique, we detected BS-RNase in the HT29 cell nucleolus after 3-h treatment. Therefore, as hTR has been recently proven to co-fractionate with nucleoli, we hypothesize that a BS-RNase direct action on the telomerase hTR subunit could be a possible mechanism of action by which BS-RNase exerts its pro-apoptotic effects only on proliferating cells.
Bovine seminal-ribonuclease (BS-RNase) is a member of the 'ribonucleases with special biological actions' family since it possesses specific anti-tumour, anti-spermatogenic and embryotoxic activities and exerts an immunosuppressive effect on T lymphocytes. In previous studies it was demonstrated that BS-RNase induced apoptosis in proliferating, malignant and normal cells and that telomerase activity loss also caused apoptotic death in neoplastic cells. Since an obvious relationship between cell proliferation and telomerase activity exists, the aim of this work was to study if the pro-apoptotic cytotoxic action exerted by BS-RNase on proliferating malignant cells (HT29) and proliferating normal cells (PHA-stimulated lymphocytes) could be linked to a possible BS-RNase effect on telomerase activity. In BS-RNasetreated HT29 cells (Na-butyrate-differentiated or not) and human lymphocytes (proliferating or not), we investigated cell vitality (MTT method) and morphology (SEM), BS-RNase localization (immunofluorescence), telomerase activity (TRAP-ELISA method), hTR mRNA expression (RT-PCR), and hTERT levels (Western blot). While no BS-RNase effect was detectable on not proliferating cells, a clear relationship was noticed between the diminished number of vital elements of both proliferating cell populations after treatment (48 h and 72 h for HT29 and PHA-stimulated lymphocytes, respectively) with 50 μg/ml BS-RNase and the decrease of their telomerase activity. At the same time, we found that hTR levels, the RNA subunit of telomerase, in proliferation-inhibited BS-RNasetreated cells were diminished. Moreover, by immunofluorescence technique, we detected BS-RNase in the HT29 cell nucleolus after 3-h treatment. Therefore, as hTR has been recently proven to co-fractionate with nucleoli, we hypothesize that a BS-RNase direct action on the telomerase hTR subunit could be a possible mechanism of action by which BS-RNase exerts its pro-apoptotic effects only on proliferating cells.
Bovine seminal-ribonuclease; Cytotoxicity; HTR; Nucleolar localization; Telomerase
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11769/43171
Citazioni
  • ???jsp.display-item.citation.pmc??? 3
  • Scopus 9
  • ???jsp.display-item.citation.isi??? 11
social impact