br In this study we demonstrated the
In this study, we demonstrated the correlation between lncRNAs and adjacent genes using the expression of HEATR6 and lncRNA, LOC105371849, which were tightly correlated in breast cancer cell lines. Knockdown of lncRNA LOC105371849 decreased the level of HEATR6 mRNA expression which resulted in some changes in cell
siRNA1 siRNA2 siRNA3
Expression level
to GAPDH
Non treat
ns
ns
Control siRNA
siRNA2
Non treat Control siRNA siRNA2
Non treat Control siRNA
siRNA2
Non treat
Ctrl siRNA
siRNA 2
ER
PR
HER2
positive
Bax
ExpressionleveltoGAPDH
1.5
ns
Non treat Control siRNA siRNA2
1.5
***
Expressionlevel
toGAPDH
1.0
Non treat Control siRNA siRNA2
Expressionlevel
toGAPDH
1.0
negative
Non treat Control siRNA
siRNA2
Expressionlevel
toGAPDH
**
Grade
Non treat Control siRNA
siRNA2
Fig. 5. Putative roles of HEATR6 in breast cancer A) Morphology of HEATR6 knockdown MCF7 cell with control cells. Scale = 100 μm. B) Relative gene expressions of cell apoptosis and proliferation markers. *, **, *** and **** indicates p-value < .05, 0.01, 0.001 and 0.0001. ns means not significant. C) KM-plot analysis using affymatrix probes (218991_at) for HEATR6. Survival data was depicted in three different molecular subtypes (ER, PR, HER2) and grades. Black: low expression, red: high expression. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
morphology. Since some cytotoxicity was found in cancer cell lines with a knockdown of lncRNA LOC105371849, we analyzed the level of BAX and BCL2 gene expression but no significant changes were found. However, the expression of proliferation markers (MKI67 and CCND1)
was decreased in cancer Dexmedetomidine transfected with siLOC105371849lncRNA. This result suggests that lncRNA LOC105371849 may be involved in cell proliferation in breast cancer via HEATR6 regulation. Furthermore, KM plotter analysis revealed that high expression level of HEATR6 in certain molecular subtype and cancer grade II and III is associated with low survival rate of breast cancer patients.
5. Conclusions
This study screened lncRNAs functionally linked to breast cancer and tested their potential role in the regulation of neighboring BCAGs. This might be an efficient way increase understanding of the regulation mechanisms of various genes in associated diseases. Using this proce-dure, we indeed demonstrated the association of HEATR6 and its ad-jacent lncRNA (LOC105371849), and putative HEATR6 functions in breast cancer proliferation in certain molecular subtypes and stages. It might be important for a better understanding of breast cancer biology and could potentially be a predictor for the prognosis of breast cancer in patients.
Acknowledgements
The authors would like to thank Prof. Han-Byul Lee at the College of Medicine, Seoul National University, for kindly providing the breast cancer cell lines.
Funding statement
This research was supported by the Bio & Medical Technology Development Program of the National Research Foundation (NRF) of Korea funded by the Ministry of Science, ICT & Future Planning (2016M3A9B6026771) and partially by (#2016R1A6A3A11932951).
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Van Poznak, C., et al., 2015. Use of biomarkers to guide decisions on systemic therapy for women with metastatic breast cancer: American society of clinical oncology clinical practice guideline. J. Oncol. Pract. 11, 514–516.