Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Mar 1;41(1):16-25.
doi: 10.4274/tjh.galenos.2024.2023.0403. Epub 2024 Jan 23.

Oncolytic Myxoma virus Increases Autophagy in Multiple Myeloma

Alpay Yeşilaltay  1 , Dilek Muz  2 , Berna Erdal  3
Affiliations

Oncolytic Myxoma virus Increases Autophagy in Multiple Myeloma

Alpay Yeşilaltay et al. Turk J Haematol. .

Abstract
in English, Turkish

Objective: Multiple myeloma, which affects plasma cells, is the second most common hematological malignancy. Despite the development of new drugs and treatment protocols, patient survival has not reached the desired level. In this study, we investigated the effects of Myxoma virus (MYXV), an oncolytic virus, on autophagy in myeloma cells.

Materials and methods: We analyzed protein expressions of ATG-5, p62, Beclin-1, LC3B, and the apoptosis marker Bcl-2 as autophagy markers in human U-266 and mouse MOPC-315 myeloma cell lines subjected to different doses of MYXV. In addition, autophagic images of myeloma cells were investigated using transmission electron microscopy (TEM).

Results: In the first 24 h, which is the early stage of autophagy, ATG-5 and Beclin-1 expression levels were increased in the U-266 and MOPC-315 cell lines in the groups that had received MYXV at a multiplicity of infection of 15. At 48 h, a significant increase was detected in the expression of LC3B, which is a late indicator. Autophagosomes were observed in myeloma cells by TEM.

Conclusion: MYXV shows an antimyeloma effect by increasing autophagy in myeloma cells.

Amaç: Plazma hücrelerini etkileyen multipl miyelom, en sık görülen ikinci hematolojik kanserdir. Yeni ilaçların ve tedavi protokollerinin geliştirilmesine rağmen, hasta sağkalımı istenilen düzeye ulaşmamıştır. Bu çalışmada, onkoltik bir virüs olan Miksoma virüsü’nün (MYXV), miyelom hücrelerinde otofaji üzerindeki etkilerini araştırdık.

Gereç ve yöntemler: İnsan U-266 ve fare MOPC-315 miyelom hücre hatlarına farklı dozlarda MYXV uygulanarak ve otofaji belirteçleri olarak ATG-5, p62, Beclin-1, LC3B ve apoptoz belirteci Bcl-2 protein ekspresyonları analiz edilmiştir. Ayrıca, miyelom hücrelerinin otofajik görüntüleri, transmisyon elektron mikroskobu (TEM) kullanılarak incelenmiştir.

Bulgular: İlk 24 saatte, yani otofajinin erken aşamasında, U-266 ve MOPC-315 hücre hatlarında MYXV’nin moi 15 enfektif dozda alındığı gruplarda ATG-5 ve Beclin-1 ekspresyon düzeyleri artmıştır. Kırk sekiz saatte, geç bir belirteç olan LC3B’nin ekspresyonunda önemli bir artış tespit edilmiştir. Miyelom hücrelerinde otofagozomlar TEM ile gözlemlenmiştir.

Sonuç: MYXV, miyelom hücrelerinde otofajiyi artırarak antimiyelom etkisi göstermektedir.

Keywords: Autophagosome; Myxoma virus; Multiple myeloma; Autophagy.

PubMed Disclaimer

Conflict of interest statement

Conflict of Interest: No conflict of interest was declared by the authors.

Figures

Figure 1
Figure 1
Myxoma virus (MYXV) infection in different cells and WST-1 results. MYXV expresses green fluorescent protein, and virus-infected cells were visualized as green under a fluorescent microscope. A) Virus-infected MOPC-315 cells, 10x. B) Virus-infected U-266 cells, 10x. C) Virus-infected Vero cells, 10x. D) WST-1 results of MYXV-infected U-266 cells. E) WST-1 results of MYXV-infected MOPC-315 cells. F) MYXV-infected U-266 cell viability percentage for each incubation period. G) MYXV-infected MOPC-315 cell viability percentage for each incubation period. WST-1 results are shown as 15 multiplicity of infection (moi), 10 moi, and 5 moi virus-infected U-266 and MOPC-315 cells for 0, 24, 48, and 72 h of incubation.
Figure 2
Figure 2
ELISA results of LC3B protein concentrations in MYXV-infected U-266 and MOPC-315 cells according to hours of incubation: A) 24 h of incubation period, B) 48 h of incubation, C) 72 h of incubation. ELISA: Enzyme-linked immunosorbent assay; MYXV: Myxoma virus.
Figure 3
Figure 3
ELISA results of p62 protein concentrations in MYXV-infected U-266 and MOPC-315 cells according to hours of incubation: A) 24 h of incubation period, B) 48 h of incubation, C) 72 h of incubation. ELISA: Enzyme-linked immunosorbent assay; MYXV: Myxoma virus.
Figure 4
Figure 4
ELISA results of Beclin-1 protein concentrations in MYXV-infected U-266 and MOPC-315 cells according to hours of incubation: A) 24 h of incubation period, B) 48 h of incubation, C) 72 h of incubation. ELISA: Enzyme-linked immunosorbent assay; MYXV: Myxoma virus.
Figure 5
Figure 5
ELISA results of ATG-5 protein concentrations in MYXV-infected U-266 and MOPC-315 cells according to hours of incubation: A) 24 h of incubation period, B) 48 h of incubation, C) 72 h of incubation. ELISA: Enzyme-linked immunosorbent assay; MYXV: Myxoma virus.
Figure 6
Figure 6
A) Electron microscopic image of cells from the MOPC-315 cell line. An autophagosome (arrow) characterized by a double-layered membrane structure containing various vesicles and degenerate structures and a mitochondrion (arrowhead) that maintains its normal structure are seen. B) Electron microscopic image of cells from the MOPC-315 cell line. An autophagosome (arrow) is seen, which is characterized by a double-layered membrane structure containing vesicles and membranes. C) Electron microscopic image of cells obtained from cell line U-266. An autolysosome (arrow) and larger lysosomes (arrowhead) adjacent to it are in the process of fusion of autophagosome membranes and lysosome. D) Electron microscopic image of cells obtained from cell line U-266. An autophagosome (arrow) and adjacent mitochondrion (arrowhead) are seen, characterized by a double-layered membrane structure containing membranes.
Figure 7
Figure 7
Autophagic vesicle counts for MYXV-infected U-266 and MOPC-315 cells. MYXV: Myxoma virus; ns: not significant.
See this image and copyright information in PMC

References

    1. Pinto V, Bergantim R, Caires HR, Seca H, Guimaraes JE, Vasconcelos MH. Multiple myeloma: available therapies and causes of drug resistance. Cancers (Basel) 2020;12:407. - PMC - PubMed
    1. Cejalvo MJ, de la Rubia J. Which therapies will move to the front line for multiple myeloma? Expert Rev Hematol. 2017;10:383–392. - PubMed
    1. Rajkumar SV. Multiple myeloma: every year a new standard? Hematol Oncol. 2019;37(Suppl 1):62–65. - PMC - PubMed
    1. Costa LJ, Brill IK, Omel J, Godby K, Kumar SK, Brown EE. Recent trends in multiple myeloma incidence and survival by age, race, and ethnicity in the United States. Blood Adv. 2017;1:282–287. - PMC - PubMed
    1. Kumar SK, Rajkumar SV. The multiple myelomas - current concepts in cytogenetic classification and therapy. Nat Rev Clin Oncol. 2018;15:409–421. - PubMed