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Mapping of apoptin-interaction with BCR-ABL1, and development of apoptin-based targeted therapy.

Jangamreddy JR, Panigrahi S, Lotfi K, Yadav M, Maddika S, Tripathi AK, Sanyal S, Łos MJ - Oncotarget (2014)

Bottom Line: Majority of chronic myeloid leukemia patients experience an adequate therapeutic effect from imatinib however, 26-37% of patients discontinue imatinib therapy due to a suboptimal response or intolerance.The synthetic apoptin is able to inhibit cell proliferation in murine (32Dp210), human cell line (K562), and ex vivo in both imatinib-resistant and imatinib sensitive CML patient samples.The apoptin based single or combination therapy may be an additional option in CML treatment and eventually be feasible as curative therapy.

View Article: PubMed Central - PubMed

Affiliation: Dept. Clinical & Experimental Medicine, Integrative Regenerative Med. Center (IGEN), Linköping University, Sweden. Authors contributed equally.

ABSTRACT
Majority of chronic myeloid leukemia patients experience an adequate therapeutic effect from imatinib however, 26-37% of patients discontinue imatinib therapy due to a suboptimal response or intolerance. Here we investigated derivatives of apoptin, a chicken anemia viral protein with selective toxicity towards cancer cells, which can be directed towards inhibiting multiple hyperactive kinases including BCR-ABL1. Our earlier studies revealed that a proline-rich segment of apoptin interacts with the SH3 domain of fusion protein BCR-ABL1 (p210) and acts as a negative regulator of BCR-ABL1 kinase and its downstream targets. In this study we show for the first time, the therapeutic potential of apoptin-derived decapeptide for the treatment of CML by establishing the minimal region of apoptin interaction domain with BCR-ABL1. We further show that the apoptin decapeptide is able to inhibit BCR-ABL1 down stream target c-Myc with a comparable efficacy to full-length apoptin and Imatinib. The synthetic apoptin is able to inhibit cell proliferation in murine (32Dp210), human cell line (K562), and ex vivo in both imatinib-resistant and imatinib sensitive CML patient samples. The apoptin based single or combination therapy may be an additional option in CML treatment and eventually be feasible as curative therapy.

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Related in: MedlinePlus

Apoptin kills both BCR-ABL1 positive and negative cells(a) Elevated level of cleaved PARP-1 in 32Dp210 cells treated with apoptin. (b) Appearance of cleaved PARP-1 and induction of apoptosis in Bcr-Abl expressing 32Dp210 cells when treated with apoptin or imatinib; (c) The effects of apoptin on the survival of Bcr-Abl expressing cells as determined by Nicoletti method. N=3. *P<0.03.
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Figure 1: Apoptin kills both BCR-ABL1 positive and negative cells(a) Elevated level of cleaved PARP-1 in 32Dp210 cells treated with apoptin. (b) Appearance of cleaved PARP-1 and induction of apoptosis in Bcr-Abl expressing 32Dp210 cells when treated with apoptin or imatinib; (c) The effects of apoptin on the survival of Bcr-Abl expressing cells as determined by Nicoletti method. N=3. *P<0.03.

Mentions: Apoptin triggers the activation of caspases via the intrinsic/mitochondrial death pathway, and not the death receptor/extrinsic pathway in cancer cells [15]. To further verify the nature of apoptin induced cell death among BCR-ABL1 expressing leukemia cells, we compared nuclear morphology of the apoptin/imatinib untreated and treated 32DDSMZ and 32Dp210 cells to study the features of apoptotic nuclei (Fig. 1a). Furthermore, we estimated the presence of cleaved PARP-1, which is a key target of activated caspase-3, or -7 in pro-apoptotic cells by Western blot analysis and immunocytochemistry (Fig. 1a and 1b). In these experiments, the characteristic apoptotic nuclear morphology and presence of cleaved PARP-1 in the cytoplasm of apoptin treated 32Dp210 cells clearly indicate the induction of apoptosis following the application of apoptin (Fig. 1a and 1b).


Mapping of apoptin-interaction with BCR-ABL1, and development of apoptin-based targeted therapy.

Jangamreddy JR, Panigrahi S, Lotfi K, Yadav M, Maddika S, Tripathi AK, Sanyal S, Łos MJ - Oncotarget (2014)

Apoptin kills both BCR-ABL1 positive and negative cells(a) Elevated level of cleaved PARP-1 in 32Dp210 cells treated with apoptin. (b) Appearance of cleaved PARP-1 and induction of apoptosis in Bcr-Abl expressing 32Dp210 cells when treated with apoptin or imatinib; (c) The effects of apoptin on the survival of Bcr-Abl expressing cells as determined by Nicoletti method. N=3. *P<0.03.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4196195&req=5

Figure 1: Apoptin kills both BCR-ABL1 positive and negative cells(a) Elevated level of cleaved PARP-1 in 32Dp210 cells treated with apoptin. (b) Appearance of cleaved PARP-1 and induction of apoptosis in Bcr-Abl expressing 32Dp210 cells when treated with apoptin or imatinib; (c) The effects of apoptin on the survival of Bcr-Abl expressing cells as determined by Nicoletti method. N=3. *P<0.03.
Mentions: Apoptin triggers the activation of caspases via the intrinsic/mitochondrial death pathway, and not the death receptor/extrinsic pathway in cancer cells [15]. To further verify the nature of apoptin induced cell death among BCR-ABL1 expressing leukemia cells, we compared nuclear morphology of the apoptin/imatinib untreated and treated 32DDSMZ and 32Dp210 cells to study the features of apoptotic nuclei (Fig. 1a). Furthermore, we estimated the presence of cleaved PARP-1, which is a key target of activated caspase-3, or -7 in pro-apoptotic cells by Western blot analysis and immunocytochemistry (Fig. 1a and 1b). In these experiments, the characteristic apoptotic nuclear morphology and presence of cleaved PARP-1 in the cytoplasm of apoptin treated 32Dp210 cells clearly indicate the induction of apoptosis following the application of apoptin (Fig. 1a and 1b).

Bottom Line: Majority of chronic myeloid leukemia patients experience an adequate therapeutic effect from imatinib however, 26-37% of patients discontinue imatinib therapy due to a suboptimal response or intolerance.The synthetic apoptin is able to inhibit cell proliferation in murine (32Dp210), human cell line (K562), and ex vivo in both imatinib-resistant and imatinib sensitive CML patient samples.The apoptin based single or combination therapy may be an additional option in CML treatment and eventually be feasible as curative therapy.

View Article: PubMed Central - PubMed

Affiliation: Dept. Clinical & Experimental Medicine, Integrative Regenerative Med. Center (IGEN), Linköping University, Sweden. Authors contributed equally.

ABSTRACT
Majority of chronic myeloid leukemia patients experience an adequate therapeutic effect from imatinib however, 26-37% of patients discontinue imatinib therapy due to a suboptimal response or intolerance. Here we investigated derivatives of apoptin, a chicken anemia viral protein with selective toxicity towards cancer cells, which can be directed towards inhibiting multiple hyperactive kinases including BCR-ABL1. Our earlier studies revealed that a proline-rich segment of apoptin interacts with the SH3 domain of fusion protein BCR-ABL1 (p210) and acts as a negative regulator of BCR-ABL1 kinase and its downstream targets. In this study we show for the first time, the therapeutic potential of apoptin-derived decapeptide for the treatment of CML by establishing the minimal region of apoptin interaction domain with BCR-ABL1. We further show that the apoptin decapeptide is able to inhibit BCR-ABL1 down stream target c-Myc with a comparable efficacy to full-length apoptin and Imatinib. The synthetic apoptin is able to inhibit cell proliferation in murine (32Dp210), human cell line (K562), and ex vivo in both imatinib-resistant and imatinib sensitive CML patient samples. The apoptin based single or combination therapy may be an additional option in CML treatment and eventually be feasible as curative therapy.

Show MeSH
Related in: MedlinePlus