TY - JOUR
T1 - Hsa-miR-323a-3p functions as a tumor suppressor and targets STAT3 in neuroblastoma cells
AU - Bhavsar, Swapnil Parashram
AU - Olsen, Lotte
AU - Løkke, Cecilie
AU - Koster, Jan
AU - Flægstad, Trond
AU - Einvik, Christer
N1 - Funding Information: This study was supported by grants from the UiT—The Arctic University of Norway, Barnekreftforeningen (Project number: 210009), Children's Cancer Association Troms and Finnmark, Helse Nord and Simon Fougner Hartmanns Familiefond. The publication charges for this article have been funded by a grant from the publication fund of UiT—The Arctic University of Norway. The funding organizations have no role in the design of the study, analysis, and interpretation of the data and in writing the manuscript. Acknowledgments Publisher Copyright: 2023 Bhavsar, Olsen, Løkke, Koster, Flægstad and Einvik.
PY - 2023
Y1 - 2023
N2 - Background: Studies conducted in the last decades have revealed a role for the non-coding microRNAs (miRNAs) in cancer development and progression. Several miRNAs within the chromosome region 14q32, a region commonly deleted in cancers, are associated with poor clinical outcome in the childhood cancer neuroblastoma. We have previously identified miR-323a-3p from this region to be downregulated in chemotherapy treated neuroblastoma cells compared to pre-treatment cells from the same patients. Furthermore, in neuroblastoma tumors, this miRNA is downregulated in advanced stage 4 disease compared to stage 1–2. In this study, we attempt to delineate the unknown functional roles of miR-323a-3p in neuroblastoma. Methods: Synthetic miRNA mimics were used to overexpress miR-323a-3p in neuroblastoma cell lines. To investigate the functional roles of miR-323a-3p, cell viability assay, flow cytometry, reverse transcription-quantitative polymerase chain reaction, luciferase reporter assay and western blot were conducted on the neuroblastoma cell lines Kelly, SH-SY5Y and SK-N-BE(2)-C. Results: Ectopic expression of miR-323a-3p resulted in marked reduction of cell viability in Kelly, SH-SY5Y and SK-N-BE(2)-C by causing G1-cell cycle arrest in Kelly and SH-SY5Y and apoptosis in all the cell lines tested. Furthermore, mRNA and protein levels of signal transducer and activator of transcription 3 (STAT3) were reduced upon miR-323a-3p overexpression. A direct binding of the miR-323a-3p to the 3′UTR of STAT3 was experimentally validated by luciferase reporter assay, where miR-323a-3p reduced luminescent signal from full length STAT3 3′UTR luciferase reporter, but not from a reporter with mutation in the predicted seed sequence. Conclusions: miR-323a-3p inhibits growth of neuroblastoma cell lines through G1-cell cycle arrest and apoptosis, and the well-known oncogene STAT3 is a direct target of this miRNA.
AB - Background: Studies conducted in the last decades have revealed a role for the non-coding microRNAs (miRNAs) in cancer development and progression. Several miRNAs within the chromosome region 14q32, a region commonly deleted in cancers, are associated with poor clinical outcome in the childhood cancer neuroblastoma. We have previously identified miR-323a-3p from this region to be downregulated in chemotherapy treated neuroblastoma cells compared to pre-treatment cells from the same patients. Furthermore, in neuroblastoma tumors, this miRNA is downregulated in advanced stage 4 disease compared to stage 1–2. In this study, we attempt to delineate the unknown functional roles of miR-323a-3p in neuroblastoma. Methods: Synthetic miRNA mimics were used to overexpress miR-323a-3p in neuroblastoma cell lines. To investigate the functional roles of miR-323a-3p, cell viability assay, flow cytometry, reverse transcription-quantitative polymerase chain reaction, luciferase reporter assay and western blot were conducted on the neuroblastoma cell lines Kelly, SH-SY5Y and SK-N-BE(2)-C. Results: Ectopic expression of miR-323a-3p resulted in marked reduction of cell viability in Kelly, SH-SY5Y and SK-N-BE(2)-C by causing G1-cell cycle arrest in Kelly and SH-SY5Y and apoptosis in all the cell lines tested. Furthermore, mRNA and protein levels of signal transducer and activator of transcription 3 (STAT3) were reduced upon miR-323a-3p overexpression. A direct binding of the miR-323a-3p to the 3′UTR of STAT3 was experimentally validated by luciferase reporter assay, where miR-323a-3p reduced luminescent signal from full length STAT3 3′UTR luciferase reporter, but not from a reporter with mutation in the predicted seed sequence. Conclusions: miR-323a-3p inhibits growth of neuroblastoma cell lines through G1-cell cycle arrest and apoptosis, and the well-known oncogene STAT3 is a direct target of this miRNA.
KW - STAT3
KW - chemotherapy
KW - chromosome region 14q32
KW - microRNAs
KW - neuroblastoma
KW - non-coding
UR - http://www.scopus.com/inward/record.url?scp=85152573027&partnerID=8YFLogxK
U2 - https://doi.org/10.3389/fped.2023.1098999
DO - https://doi.org/10.3389/fped.2023.1098999
M3 - Article
C2 - 37033189
SN - 2296-2360
VL - 11
JO - Frontiers in pediatrics
JF - Frontiers in pediatrics
M1 - 1098999
ER -