Bovine seminal ribonuclease triggers Beclin1-mediated autophagic cell death in pancreatic cancer cells.
Among the large number of variants belonging to the pancreatic-type secretory ribonuclease (RNase) superfamily, bovine pancreatic ribonuclease (RNase A) is the proto-type and bovine seminal RNase (BS-RNase) represents the unique natively dimeric member. In the present manuscript, we evaluate the anti-tumoral property of these RNases in pancreatic adenocarcinoma cell lines and in nontumorigenic cells as normal control. We demonstrate that BS-RNase stimulates a strong anti-proliferative and pro-apoptotic effect in cancer cells, while RNase A is largely ineffective. Notably, we reveal for the first time that BS-RNase triggers Beclin1-mediated autophagic cancer cell death, providing evidences that high proliferation rate of cancer cells may render them more susceptible to autophagy by BS-RNase treatment. Notably, to improve the autophagic response of cancer cells to BS-RNase we used two different strategies: the more basic (as compared to WT enzyme) G38K mutant of BS-RNase, known to interact more strongly than wt with the acidic membrane of cancer cells, or BS-RNase oligomerization (tetramerization or formation of larger oligomers). Both mutant BS-RNase and BS-RNase oligomers potentiated autophagic cell death as compared to WT native dimer of BS-RNase, while the various RNase A oligomers remained completely ineffective. Altogether, our results shed more light on the mechanisms lying at the basis of BS-RNase antiproliferative effect in cancer cells, and support its potential use to develop new anti-cancer strategies.
Department of Life and Reproduction Sciences, Biochemistry Section, University of Verona, Verona, Italy.
Claudia
C
Fiorini
Department of Life and Reproduction Sciences, Biochemistry Section, University of Verona, Verona, Italy. Electronic address: giovanni.gotte@univr.it.
Giovanni
G
Gotte
Department of Chemical Sciences, University of Naples "Federico II", Naples, Italy.
Federica
F
Donnarumma
Department of Chemical Sciences, University of Naples "Federico II", Naples, Italy.
Delia
D
Picone
Department of Life and Reproduction Sciences, Biochemistry Section, University of Verona, Verona, Italy. Electronic address: massimo.donadelli@univr.it.
Massimo
M
Donadelli
D000230:Adenocarcinoma / Q000473:pathology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins / Q000502:physiology*; D001343:Autophagy / Q000187:drug effects* / Q000502:physiology; D000071186:Beclin-1; D002417:Cattle; D045744:Cell Line, Tumor; D008297:Male; D008565:Membrane Proteins / Q000502:physiology*; D010190:Pancreatic Neoplasms / Q000473:pathology*; D012259:Ribonuclease, Pancreatic / Q000494:pharmacology*; D012661:Semen / Q000201:enzymology*
D051017:Apoptosis Regulatory Proteins; C491997:BECN1 protein, human; D000071186:Beclin-1; D008565:Membrane Proteins; D012259:Ribonuclease, Pancreatic
Autophagy; BS-RNase; Beclin1; Pancreatic cancer; RNase A; RNase oligomers