Kuang et al. BMC Molecular and Cell Biology
https://doi.org/10.1186/s12860-023-00494-1

BMC Molecular and Cell
Biology(2023) 24:34

Open Access

RESEARCH

Effect of Emi1 gene silencing on the
proliferation and invasion of human breast
cancer cells
Ying Kuang1, Shengwen Huang1*, Shifan Tang1, Zhaozhen Zhuo1 and Keyan Linghu1
Abstract
Breast cancer is the most common malignant tumour in women. The early silk-splitting inhibitor protein 1 Emi1
is responsible for mediating ubiquitin protein degradation. The present study investigated the effects of thedecreased expression of the Emil gene on the proliferation and invasion of breast cancer cells. The interference
efficiency of small interfering ribonucleic acid (siRNA) was quantitatively verified using fluorescence real-timequantitative polymerase chain reaction (RT-qPCR) and Western blotting, and the effect of Emi1 gene silencing
on cell vitality and invasion was determined using MTT and Transwell assays, respectively. The expression of theproliferation genes programmed cell death receptor 4 (PDCD-4), fatty acid synthase ligand (FasL), PTEN and RhoB,
along with the invasive genes Maspin, TIMP3 and RECK, was measured using fluorescence RT-qPCR. In breast
cancer cells, siRNA successfully reduced the expression of the Emi1 gene, and the expression level of the cellproliferation genes PDCD-4, FasL, PTEN and RhoB, along with invasive genes Maspin, TIMP3 and RECK, decreased
significantly (P < 0.05). Furthermore, Emi1 gene silencing reduced the proliferation and invasion abilities of MDAMB-231 and SUM149PT cells by reducing the expression of proliferative and invasive genes.
Keywords Emi1 gene, Breast cancer, Proliferation, Invasion

Introduction
Breast cancer is the most common malignant tumour in
women and the main cause of cancer deaths in women.
The incidence of breast cancer has been reported toaccount for 7–10% of all malignant tumours. Reports
show that globally, approx. 1.2 million women suffer from breast cancer every year, and 500,000 die fromthe disease [1]. In Europe and North America, the incidence of breast cancer accounts for the highest proportion of malignant tumours in women. The growth rate

*Correspondence:
Shengwen Huang
huang_shengwen@yeah.net
1
Department of Antenatal Diagnostic Centre, Guizhou Provincial People’s
Hospital, No. 56 East Zhongshan Road, Guizhou 550000, Guizhou, China

of breast cancer incidence in China is almost the sameas the growth rate of global breast cancer incidence. It
is expected that by 2021, the incidence of breast cancer
in China will rise to > 100 cases per 100,000 women, or> 2.5 million cases in total [2]. Traditional therapies, suchas surgery, chemotherapy and radiotherapy, essentiallycause adverse effects in patients. With the in-depth studyof the molecular mechanisms of tumour cell growth,proliferation and apoptosis, modern tumour therapy
has entered the era of biological therapy, and targetedtumour therapy has become possible.
The early fission inhibitory protein 1, Emi1, which
belongs to the F-box protein family (also known as
FBOX5), can be involved in the formation of the Skp1Cull-F-box-protein ubiquitin connection enzyme andmediates ubiquitin protein degradation [3, 4]. The© The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use,sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) andthe source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in thisarticle are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not includedin the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you willneed to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The
Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available
in this article, unless otherwise stated in a credit line to the data.

Kuang et al. BMC Molecular and Cell Biology(2023) 24:34

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expression of Emi1 in colon cancer has been reported
as increased and associated with the malignancy andpoor prognosis of tumours. In order to further study
the mechanism of the Emi1 gene in the development ofbreast cancer, small interfering ribonucleic acid (siRNA)
was infected with human breast cancer cell lines. Afterscreening and verification, a stable reduction of anEmi1 gene breast cancer cell model was successfully
established.
Studies have reported that the programmed cell death
receptor 4 (PDCD-4), fatty acid synthase ligand (FasL),PTEN and RhoB genes are related to the proliferative
regulation of breast cancer cells and that Maspin, TIMP3
and RECK genes are related to the invasion regulation ofbreast cancer cells [5–7]. The present study showed that
Emi1 gene silencing can reduce the biological activity of
MDA-MB-231 and SUM149PT cells by decreasing theexpression of proliferative and invasive genes. After finding that the knockdown (KD) of Emi1 reduced the proliferation and invasion abilities of breast cancer cells, theauthors further explored the molecular mechanism bywhich Emi1 affects breast cancer cells.

was transfected with Emi1 without effective infection,and the empty control (CON) group was transfectedwith a chronic viral vector, LV-CON. The cells were subsequently collected. The total RNA was extracted with
TRIzol lysate, and the concentration and quality of the
RNA were measured using a NanoDrop™ 2000/2000 C
spectrophotometer.

Materials and methods

The RNAi lentiviral vector was prepared via synthesis,
construction, identification, sequencing and extraction.
The siRNA lentiviral expression vector targeting theEmi1 gene included three target sequences as follows:
Emi1-RNAi (1): TCGCTGTAATTCACCTGCAAA;
Emi1-RNAi (2): CCAGACCAATATCCCAACAAA;
and Emi1-RNAi (3): CGGTGTAGTATCCTGAGGTTT.
The tool carrier number was GV248, the frame structure was hU6-MCS-Ubiquitin-EGFP-IRES-puromycin,
the control number was CON077, and the control insert
sequence was TTCTCCGAACGTGTCACGT.

Experimental materials

The human breast cancer cell strains MDA-MB-231 andSUM149PT were purchased from the Shanghai Instituteof Cell Biology at the Chinese Academy of Sciences, andlentiviral scrambling vector LV-Emi1-ribonucleic interference (RNAi) and negative-control viral vector LVEmi1-RNAi were obtained from Shanghai Genechem.
Reverse transcription (RT) primers were obtained
from GeneRay (CA, USA), and microRNA polymerase
chain reaction (PCR) was obtained from Thermo Scientific (MA, USA). Both M-MLV kits and deoxynucleotide triphosphates were obtained from Promega(MA, USA), and MTS cell viability detection kits wereobtained from Shanghai Sangon. Lipofectamine™ 2000
was obtained from Thermo Scientific (MA, USA), andTRIzol™ was obtained from Shanghai Pufei. Finally, TaqMan PCR (qPCR) primers were obtained from Shanghai
Genechem, and TaqMan PCR kits were obtained from
Thermo Scientific (12,574,035, MA, USA).
Experimental methods
Total RNA extraction

The cell lines MDA-MB-231 and SUM149PT were purchased from the Cell Resource Center, Shanghai Academy of Life Sciences and cultured in Dulbecco’s modified
Eagle medium containing 10% foetal serum. After thecell density reached approx. 70–80%, the experimental (KD) group was transfected with a lentiviral vector(LV-Emi1-RNAi) containing an effective interference
sequence against Emil. The negative control (NC) group

Reverse transcription to obtain cDNA

For the microRNA reverse transcription, the primer
information was as follows: for the endogenous reference gene GAPDH, the upstream primer sequence was
TGACTTCAACAGCGACACCCA, and the downstream
primer sequence was CACCCTGTTGCTGTAGCCAAA. The amplified fragment was 121 bp. For the target
gene Emi1, the upstream primer sequence was CGAGAAGGCTGTGGATTTGAT, and the downstream primer
sequence was ACCAGGCAGGGGACCTATTTT. The
amplified fragment was 117 bp. After the primers wereprepared, RNA RT and two-step real-time RT-PCR were
performed, and a dissolution curve was created.
Design of ribonucleic acid targeting the Emi1 gene

RNAi lentivirus packaging, concentration and purification,
titer determination and Infection of target cells

The amount of virus used was calculated. Human breast
cancer cells MDA-MB-231 and SUM149PT were inoculated on 12-well plates in accordance with the KD group(LV-Emi1-RNAi, named according to the lentiviral vector containing the effective interference sequence target,
Emil), the NC group (without effective Emi1 infection)and the CON group (the chronic viral vector, LV-CON).
The cells were kept in an incubator containing carbon
dioxide. Lentiviral infection was performed after threedays, and the medium was changed after 12 h. The infection efficiency of the virus was observed under a fluorescence microscope. When the fluorescence rate wasapprox. 70–80% and the confluence rate was approx.
80%, the cells were collected. Next, RNA was extracted
4 days after cell proliferation and infection in each group,and the level of Emi1 mRNA expression in each group
was determined.

Kuang et al. BMC Molecular and Cell Biology(2023) 24:34

Real-time quantitative polymerase chain reaction of Emi1
and possible targeted proliferation and invasion-related
genes

The LV-Emi1-RNAi virus particles containing the target gene were used to infect the target cells. The fluorescence of the cells was observed using a fluorescencemicroscope; the infection rate was > 50%. The cells werecollected, RNA was extracted and reverse transcribed
into cDNA, and the expression of Emi1 mRNA in eachgroup was determined. When detecting the mRNA content of Emi1, the cells were seeded in a 12-well cell culture plate. After 24 h of transfection, the medium was
discarded. After washing twice with phosphate-bufferedsaline, TRIzol lysate was added, and the total RNA wasextracted. The RT was conducted with 1-μg RNA, andcDNA was obtained and amplified according to the following procedures.
The reaction mixtures were incubated at 50 °C for
15 min, followed by 95 °C for 5 min; next, 40 PCR cycles
were performed with the following temperature profiles:
95 °C for 15 s, 60 °C for 30 s and 72 °C for 1 min; the amplification curve and the number of take-off cycles (Ct) wereobtained. The mRNA content was calculated according to
2 − ΔΔCt. TaqMan PCR kits were obtained from Thermo
Scientific (12,574,035, the United States). The PlatinumTaq enzyme was used. The primer sequence information is as follows: GAPDH: F: TGACTTCAACAGCGACACCCA; R: CACCCTGTTGCTGTAGCCAAA. Emi1:
F: CGAGAAGGCTGTGGATTTGAT; R: ACCAGGCAGGGGACCTATTTT. PDCD-4: F: TTGAGCACGGAGATACGAAC; R: GTCCCGCAAAGGTCAGAAAG.
FasL:F:
GGCCTGTGTCTCCTTGTGAT;R:TGCCAGCTCCTTCTGAAGTA.
PTEN:F:TGGATTCGACTTAGACTTGACCT; R: GGTGGGTTATGGTCTTCAAAAGG. RhoB: F: ATCCCCGAGAAGTGGGTCC; R: CGAGGTAGTCGTAGGCTTGGA.
Maspin: F: GCCAGGAGCACGGATCCT; R: GTTGTGCCTGATGTAAATAAAGG.
TIMP3:F:
CAGGTCGCGTCTATGATGGC; R: AGGTGATACCGATAGTTCAGCC. RECK: F: AGTGCGGGTGCATTGTGTT; R: TTCACAGCAGCCTAAGCCAAC.

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Western blotting for Emi1 protein level detection

The total protein was extracted from the infected cells;
the protein concentration was determined using thebicinchoninic acid assay method, and the protein levelof Emi1 was detected using Western blotting (WB), as
previously described [7]. The primary antibody (antiEmi1 antibody) (ab215765, Abcam, Cambridge, UK) was
diluted at a ratio of 1:200 and incubated overnight at 4 °C;
the secondary antibody (Anti-rabbit IgG, HRP-linked
Antibody, #7074, Cell Signaling Technology, MA, USA)was diluted at a ratio of 1:2,500 ~ 3,000 and incubatedat room temperature for 1 h. The protein bands were
scanned by a computer, and the grey level was analysedby software. The expression rate of Emi1 (Emi1/GAPDH[ratio of grey value])% was determined using GAPDH as
an endogenous reference.
Cell viability test

To detect cell viability, the cells were seeded in a 96-wellculture plate. After 24 h of transfection, 20 μl of MTS
detection solution was added to the culture system. After
4 h of continuous incubation, the culture plate was placedin a microplate reader, and the absorbance (OD) value ata wavelength of 490 nm was measured [8].
Cell invasion detection

To detect cell invasion, the cells were seeded in a Transwell chamber. After 24 h of transfection, the cell plateat the bottom of the chamber was removed and stainedwith DAPI staining solution. The numbers of cells inthree high-power fields were counted under a fluorescence microscope [8].
Statistical methods

The data were recorded and processed using the SPSS
20.0 software. First, the data were tested to see if theycorresponded to a normal distribution; if they did, thedata between the two groups were analysed by a twotailed t-test. A P value of < 0.05 indicated that the difference was statistically significant. A nonparametric test
was used for non-normal distribution.

Results
Table 1 Expression of the FBXO5 gene in human MDA-MB-231
cell strainsGroup
FBXO5 GroupGAPDH Group∆Ct

Well 1
20.08
13.25
6.83

Well 2
20.15
13.24
6.91

Well 3
20.15
13.15
7

Note: The ∆Ct of the endogenous reference gene well is 0.100; the ∆Ct of thetarget gene well is 0.070∆Ct = target gene Ct value-endogenous reference gene Ct value; when ∆Ct ≤ 12,
the gene expression abundance in the cell is highExpression and knockdown of the Emi1 gene in humanbreast cancer cell strains

In the present study, Emi1 KD was conducted to investigate the effect on breast cancer cells. The detectionof the Emi1 gene expression in human MDA-MB-231
and SUM149PT cell strains was conducted using RTqPCR. The results are shown in Table 1. The Emi1 gene
was highly expressed in human MDA-MB-231 andSUM149PT cell lines.
In order to further explore the function of theEmi1 gene, a lentivirus containing Emi1-siRNA wasKuang et al. BMC Molecular and Cell Biology(2023) 24:34

constructed to decrease the expression level of Emi1 by
infecting MDA-MB-231 and SUM149PT cells. In termsof Emi1 mRNA expression, the expression level was significantly lower in the KD group than in the CON group;
however, there was no significant difference between the
CON group and NC group (Fig. 1A). Green fluorescence(Fig. 1B and C) in the MDA-MB-231 cells was observed
under an inverted fluorescence microscope. Counting
and formula calculations revealed the transfection efficiency to be 90%. The results showed that Emi1-siRNA
successfully decreased the expression of the Emi1 gene.
The expression of Emi1 in MDA-MB-231 andSUM149PT cells was detected using RT-qPCR and WB.
The results are shown in Fig. 2. In the RT-qPCR detection of the Emi1 gene KD efficiency, siRNA successfully
knocked down the Emi1 gene in both MDA-MB-231 andSUM149PT cells (KD efficiency of > 75%) (Fig. 2A). The
WB results showed that Emi1-siRNA transfection could
knock down Emi1 protein expression. The WB results
also showed that the expression of the Emi1 protein was
lower in the KD group than in the CON group and thatthe level of Emi1 in the KD group decreased (KD efficiency of > 50%) (Fig. 2B and C). The results revealed that
Emi1-siRNA successfully decreased the expression of theEmi1 gene at the protein level.
Knockdown of Emi1 reduced the migration ability of
MDA-MB-231 cells

To further study the effect of the Emi1 gene on cell
migration ability, the authors compared the migration
ability of cells in different transfection groups using theTranswell assay. The results showed that the cell transfer rate in the Emi1-siRNA KD group was reduced whencompared with the CON group (transfer rate of < 50%)
(P < 0.05) (Fig. 3A and B). The results revealed that Emi1
KD reduced the migration ability of breast cancer cells.
Cell viability

After the transfection of the Emi1-siRNA in the KD
group and the NC group, the OD value of the cells in
the NC group was 0.980 ± 0.101, which was significantly
higher than the OD value of the KD group (0.561 ± 0.077).
The difference between the two groups was statisticallysignificant. The results showed that Emi1 KD decreased
the cell viability of breast cancer cells.
Knockdown of Emi1 reduced the expression of
proliferation-related and invasion-related genes

To further study the relationship between Emi1 andcell proliferation/invasion, siRNA was used to interferewith Emi1 cellular expression. The results showed thatthe mRNA levels of PDCD-4, FasL, PTEN and RhoB in
the KD group were significantly lower than those in the
CON group after Emi1 KD (2× higher in the CON group

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than in the KD group) (Fig. 4A–D). The mRNA levelsof Maspin, TIMP3 and RECK in the MDA-MB-231 andSUM149PT cells were significantly lower than those in
the CON group after Emi1 KD by siRNA (2× higher in
the CON group than in the KD group) (Fig. 4E–G). These
results indicate that Emi1 is involved in the regulationof cell proliferation and invasion activities. The findings
revealed that the KD of Emi1 decreased the expression of
proliferation-related and invasion-related genes.

Discussion
In this study, siRNA was used to knock down the expression of the Emi1 gene in MDA-MB-231 and SUM149PT
cells, and Emi1 was found to have an important role inregulating tumour cell proliferation and migration. After
constructing a lentivirus containing Emi1-siRNA, thestudy authors found that Emi1-siRNA could significantly
reduce the expression of Emi1 in MDA-MB-231 andSUM149PT cells. Additionally, the results showed that
the KD of Emi1 reduced the proliferation and migration
abilities of tumour cells and downregulated the expression of proliferation-related and migration-related genes.
The Emi1 oncogene is an important cell cycle regulator that can promote the S and G2 phases by inhibiting
the activity of the anaphase-promoting complex/cyclic
body (APC/C); it is also related to the process of mitosis[9, 10]. Emi1 is highly expressed and plays an importantrole in some cancers; it is highly expressed in cancer andpromotes tumour progression [11]. In chronic myeloid
leukaemia (CML), Bcr-Abl enhances the phosphorylation
stability of Emi1, thereby preventing the degradation of
SKP2 and promoting the proliferation of CML cells [12].
Emi1 is highly expressed in breast, liver and colon cancer, and its expression is related to the degree of tumour
malignancy [13].
Ribonucleic interference technology plays a very
important role in the field of gene therapy for malignant
tumours and has attracted much attention [14]. Moustafa
et al. [13] reported that the downstream effects of Emi1
downregulation that contribute to poly-adenosine
diphosphate ribose polymerase inhibitor (PARPi) resistance are increasing the concentration of the RAD51
protein in triple-negative breast cancer (TNBC) cells.
They showed that the KD of Emi1 in TNBC reduced cell
viability, which is consistent with the results of the present study. However, they did not investigate the effect ofEmi1 KD on the invasion ability of breast cancer cells.
Marzio et al. [4] also reported that cellular levels of
RAD51 are kept in check by Emi1-mediated degradation.
The downregulation of Emi1 in BRCA1-deficient breast
cancer cells induces primary and acquired resistanceto PARPi both in vitro and in vivo. The present study
detected the expression of proliferation-related and invasion-related genes in breast cancer cell lines in the siRNAKuang et al. BMC Molecular and Cell Biology(2023) 24:34

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Fig. 1 (A) The expression level of Emi1 of each group measured by RT-QPCR. (B) The bright field view of MDA-MB-231 and SUM149PT cells under amicroscope after lentivirus infection. (C) Fluorescence images of MDA-MB-231 and SUM149PT cells under a microscope after lentivirus infection. CON:
control cells transfected with LV-CON, KD: cells transfected with Emi1-RNAi, NC: cells transfected with LV-GFP virous. All data were expressed as Mean ± SD,*P < 0.05

Kuang et al. BMC Molecular and Cell Biology(2023) 24:34

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Fig. 2 (A) The expression level of Emi1 of each group measured by RT-QPCR. (B) Immunoblotting results of Emi1 expression in different groups. (C) Statistic graph of Emi1 relative expression. CON: control cells transfected with LV-CON, KD: cells transfected with Emi1-RNAi, NC: cells transfected with LV-GFP
virus. All data were expressed as Mean ± SD, ns means no significance, *P < 0.05

KD group, and all showed a significant decline, confirming that the Emi1 gene is involved in the biological process of breast cancer cells in vitro.
During the occurrence and development of breast cancer, a variety of molecules are involved in the regulationof cell proliferation and invasion, and there are Emi1
binding sites in the 3’ untranslated region of a variety
of proliferation-related and invasion-related mRNAs[4]. The proteins encoded by the PDCD-4, FasL, PTEN
and RhoB genes are related to the regulation of breast

Kuang et al. BMC Molecular and Cell Biology(2023) 24:34

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Fig. 3 (A) The statistic graph of numbers of transferred cells in Transwell assay. (B) The statistic graph of the changes in the number of cells transferred in
the transwell chamber. CON: control cells transfected with LV-CON, KD: cells transfected with Emi1-RNAi, NC: cells transfected with LV-GFP virous. All data
were expressed as Mean ± SD, *P < 0.05

cancer cell proliferation, and the proteins encoded by the
Maspin, TIMP3 and RECK genes are related to the regulation of breast cancer cell invasion. The PDCD-4, FasL,
PTEN and RhoB genes have tumour-suppressing effects,
and their expression is significantly reduced in malignant tumours, such as breast cancer and lung cancer [15,16]. The FasL gene belongs to the superfamily of tumour
necrosis factor receptors and is a signal receptor of cell
apoptosis. After binding to FasL, it can induce apoptosis
and activate cellular immunity to kill target cells [17]. The
PDCD-4 gene is part of a class of tumour suppressors,which is located in the nucleus and can inhibit cell proliferation and promote apoptosis through the Sp transcription factor. The protein encoded by PTEN contains a loop
structure with four amino acid residues inserted into thesequence, which can induce cell cycle arrest and apoptosis via the PI3K/Akt pathway [18]. Steven D. Cappell
et al. [19] reported that mammalian cells commit to thecell cycle by increasing CDK2 activity and Emi1-mRNA
expression to trigger a one-way APC/CCdh1 inactivation
switch mediated by Emi1 transitioning from a substrate
to an inhibitor of APC/CCdh1. After the transfection ofsiEmi1, the mRNA levels of proliferation-related molecules PDCD-4, FasL, PTEN and RhoB in breast cancer
cell strains were significantly reduced. This confirms that
Emi1 KD can regulate the proliferation-related proteins
PDCD-4, FasL, PTEN and RhoB in breast cancer cells.
Maspin, TIMP3 and RECK are genes with an invasion inhibitory effect. These proteins tend to be underexpressed in breast cancer and lung cancer, which will inturn increase the invasion ability of cancer cells. Maspin
belongs to the serine protease inhibitor superfamily, and
it is a type of secreted protein that can block the bindingof urokinase plasminogen activator (uPA) to the receptor uPA receptor and inhibit cell invasion [20]. The protein encoded by RECK contains three serine hydrolase
inhibitor regions; it inhibits the secretion and activityof a variety of MMPs and can hinder the degradation of

extracellular matrix by MMP2 and MMP9 [21]. Tissue
inhibitors of metalloproteinases (which inhibit of the tissue pathway of metalloproteinases) can directly bind to
MMPs and inhibit their functions, blocking the degradation of the extracellular matrix [22]. S Vaidyanathan et al.
[23] reported that Emi1 overexpression promotes chromosome instability, and the formation of solid cancers invivo indicates that Emi1 overexpression actively drives
solid tumorigenesis. After the transfection of siEmi1
mimics, the mRNA levels of the invasion-related genes
Maspin, TIMP3 and RECK in breast cancer cell strains
were significantly reduced. This indicated that Emi1 KD
can regulate the invasion-related genes Maspin, TIMP3
and RECK in breast cancer cells.
The lentiviral vector used in the current study has anextremely high transfection efficiency and can easilytransfect the target gene into cells, which is a very effective method of gene manipulation. Based on this, theauthors of the present study performed relevant tests
at the tumour cell level. However, the study has several
limitations: (1) the authors did not study whether the
proliferation and migration of breast cancer cells in vivo
are related to the expression of Emi1. In the next study,a lentivirus will be used to infect breast cancer cells invivo and knock down the expression of Emi1. The role ofEmi1 in the proliferation and metastasis of breast cancer
cells will be further confirmed by monitoring the occurrence and development of tumours in mice. (2) The study
results only confirmed that KD can inhibit the proliferation and metastasis of breast cancer cells. Examining theoverexpression of Emi1 in tumour cells is still required
for more in-depth research on whether Emi1 directly or
indirectly regulates proliferation-related and metastasisrelated genes. Further studies are needed to clarify themolecular mechanism by which Emi1 regulates breast
cancer proliferation and invasion.

Kuang et al. BMC Molecular and Cell Biology(2023) 24:34

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Fig. 4 (A-D) The statistic graph of proliferation-related genes mRNA level in different groups. (E-G) The statistic graph of invasive-related genes mRNAlevel in different groups. CON: control cells transfected with LV-CON, KD: cells transfected with Emi1-RNAi, All data were expressed as Mean ± SD, *P < 0.05

Kuang et al. BMC Molecular and Cell Biology(2023) 24:34

Conclusions
In this study, siRNA was used to downregulate the highexpression of the Emi1 gene in breast cancer cells, inhibit
downstream signal transduction and achieve the effectof downregulating the expression of downstream target
genes, thereby decreasing the proliferation and invasion
ability of tumours. Additionally, it provides a cell model
for subsequent in vivo experiments as well as an experimental basis for the targeted treatment of breast cancer.
Supplementary Information

The online version contains supplementary material available at https://doi.
org/10.1186/s12860-023-00494-1.
Supplementary Material 1
Supplementary Material 2
Supplementary Material 3
Supplementary Material 4
Supplementary Material 5
Supplementary Material 6
Supplementary Material 7
Supplementary Material 8
Supplementary Material 9
Supplementary Material 10
Supplementary Material 11
Supplementary Material 12
Acknowledgements
We would like to express our gratitude to all those who helped us during thewriting of this manuscript.
Authors’ contributions
KY and HSW conceived of the study, and TSF and ZZZ participated in its
design and coordination and LHKY helped to draft the manuscript. All authors
read and approved the final manuscript.
FundingNational Natural Science Foundation of China (Grant number 81960040).
Data Availability
All data generated or analyzed during this study are included in this publishedarticle.

Declarations
Ethics approval and consent to participate
This study was conducted in accordance with the Declaration of Helsinki andapproved by the ethics committee of Guizhou Provincial People’s Hospital. The
informed consent is not applicable for the study.
Consent for publication
Not applicable.
Competing interests
The authors declare no competing interests.
Received: 22 March 2023 / Accepted: 1 November 2023

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