Background: Combined chemoradiation offers a promising therapeutic strategy for dogs with glioma. The alkylating agents temozolomide (TMZ) and lomustine (CCNU) penetrate the blood-brain barrier, and doses for dogs are established. Whether such combinations are clinically advantageous remains to be explored together with tumour-specific markers. Objective: To investigate if triple combination of lomustine, temozolomide and irradiation reduces canine glioma cell survival in vitro. Methods: We evaluated the sensitising effect of CCNU alone and in combination with TMZ-irradiation in canine glioma J3T-BG cells and long-term drug-exposed subclones by using clonogenic survival and proliferation assays. Bisulphite-SEQ and Western Blot were used to investigate molecular alterations. Results: TMZ (200 μM) or CCNU alone (5 μM) reduced the irradiated survival fraction (4 Gy) from 60% to 38% (p = 0.0074) and 26% (p = 0.0002), respectively. The double-drug combination reduced the irradiated survival fraction (4 Gy) more potently to 12% (p < 0.0001). After long-term drug exposure, both subclones show higher IC50 values against CCNU and TMZ. For CCNU-resistant cells, both, single-drug CCNU (p = 0.0006) and TMZ (p = 0.0326) treatment combined with irradiation (4 Gy) remained effective. The double-drug-irradiation combination reduced the cell survival by 86% (p < 0.0001), compared to 92% in the parental (nonresistant) cell line. For TMZ-resistant cells, only the double-drug combination with irradiation (4 Gy) reduced the cell survival by 88% (p = 0.0057) while single-drug treatment lost efficacy. Chemoresistant cell lines demonstrated higher P-gp expression while MGMT-methylation profile analysis showed a general high methylation level in the parental and long-term treated cell lines. Conclusions: Our findings indicate that combining CCNU with TMZ-irradiation significantly reduces canine glioma cell survival. Such a combination could overcome current challenges of therapeutic resistance to improve overall patient survival.
Triple combination of lomustine, temozolomide and irradiation reduces canine glioma cell survival in vitro / Fuchs D.; Rohrer Bley C.; Morandi L.; Tonon C.; Weyland M.S.; Nytko K.J.. - In: VETERINARY MEDICINE AND SCIENCE. - ISSN 2053-1095. - ELETTRONICO. - 9:4(2023), pp. 1573-1583. [10.1002/vms3.1181]
Triple combination of lomustine, temozolomide and irradiation reduces canine glioma cell survival in vitro
Morandi L.Formal Analysis
;Tonon C.Supervision
;
2023
Abstract
Background: Combined chemoradiation offers a promising therapeutic strategy for dogs with glioma. The alkylating agents temozolomide (TMZ) and lomustine (CCNU) penetrate the blood-brain barrier, and doses for dogs are established. Whether such combinations are clinically advantageous remains to be explored together with tumour-specific markers. Objective: To investigate if triple combination of lomustine, temozolomide and irradiation reduces canine glioma cell survival in vitro. Methods: We evaluated the sensitising effect of CCNU alone and in combination with TMZ-irradiation in canine glioma J3T-BG cells and long-term drug-exposed subclones by using clonogenic survival and proliferation assays. Bisulphite-SEQ and Western Blot were used to investigate molecular alterations. Results: TMZ (200 μM) or CCNU alone (5 μM) reduced the irradiated survival fraction (4 Gy) from 60% to 38% (p = 0.0074) and 26% (p = 0.0002), respectively. The double-drug combination reduced the irradiated survival fraction (4 Gy) more potently to 12% (p < 0.0001). After long-term drug exposure, both subclones show higher IC50 values against CCNU and TMZ. For CCNU-resistant cells, both, single-drug CCNU (p = 0.0006) and TMZ (p = 0.0326) treatment combined with irradiation (4 Gy) remained effective. The double-drug-irradiation combination reduced the cell survival by 86% (p < 0.0001), compared to 92% in the parental (nonresistant) cell line. For TMZ-resistant cells, only the double-drug combination with irradiation (4 Gy) reduced the cell survival by 88% (p = 0.0057) while single-drug treatment lost efficacy. Chemoresistant cell lines demonstrated higher P-gp expression while MGMT-methylation profile analysis showed a general high methylation level in the parental and long-term treated cell lines. Conclusions: Our findings indicate that combining CCNU with TMZ-irradiation significantly reduces canine glioma cell survival. Such a combination could overcome current challenges of therapeutic resistance to improve overall patient survival.File | Dimensione | Formato | |
---|---|---|---|
Veterinary+Medicine+++Sci+-+2023+-+Fuchs+-+Triple+combination+of+lomustine++temozolomide+and+irradiation+reduces+canine.pdf
accesso aperto
Tipo:
Versione (PDF) editoriale
Licenza:
Licenza per Accesso Aperto. Creative Commons Attribuzione - Non commerciale - Non opere derivate (CCBYNCND)
Dimensione
1.06 MB
Formato
Adobe PDF
|
1.06 MB | Adobe PDF | Visualizza/Apri |
31181.zip
accesso aperto
Tipo:
File Supplementare
Licenza:
Licenza per Accesso Aperto. Creative Commons Attribuzione - Non commerciale - Non opere derivate (CCBYNCND)
Dimensione
12.23 MB
Formato
Zip File
|
12.23 MB | Zip File | Visualizza/Apri |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.