ORIGINAL PAPER

LncRNA UCA1-miR-507-FOXM1 axis is involved in cellproliferation, invasion and G0/G1 cell cycle arrest in melanoma

Yanping Wei1 • Qianqian Sun2 • Lindong Zhao1 • Jianbo Wu2 • Xiaonan Chen2 •

Yuanyuan Wang2 • Wenqiao Zang2 • Guoqiang Zhao2,3

Received: 4 May 2016 / Accepted: 1 July 2016 / Published online: 7 July 2016

� Springer Science+Business Media New York 2016

Abstract Recently, the incidence of melanoma has been

on the rise. Patients with distant metastasis share poor

prognosis. Increasing studies have been conducted to

clarify the molecular mechanisms as well as to investigate

potential effective therapeutic targets in the development of

melanoma. This study focuses on the LncRNA UCA1 and

its downstream regulated factors. In our experiments,

UCA1 expression was discovered to be upregulated in

melanoma tissues and cells, while the depletion of UCA1

led to the inhibition of cell proliferation, invasion and cell

cycle arrest. To further our understanding of the mecha-

nisms of UCA1, a system of experiments was built. We

found that miR-507 could directly bind to UCA1 at the

miRNA recognition site, and that there was a negative

correlation between miR-507 and UCA1. Additionally,

FOXM1 is a target of miR-507 and can be downregulated

by either miR-507 overexpression or UCA1 depletion.

Downregulated FOXM1 was analogous to the depletion of

UCA1 and the overexpression of miR-507. These results,

taken together, provide evidence for a novel UCA1 inter-

action regulatory network in tumorigenesis of melanoma.

Keywords Melanoma � LncRNA UCA1 � miR-507 �FOXM1

Introduction

Melanoma is a deadly malignancy if not caught early, and

its incidence has increased more rapidly than that of any

other type of cancer worldwide [1]. According to recent

estimates, melanoma will likely surpass colorectal cancer

to become the fifth most common type of cancer by 2030

[2]. Despite the fact that numerous treatments exist, the

most effective treatment method still relies heavily on early

diagnosis and surgical resection. People with distant

metastasis receive poor prognosis, with a 5-year survival

rate of only 16 % [3]. Melanoma formation is the result of

multiple factors involving many kinds of oncogene acti-

vation and anti-oncogene inactivation. Nowadays, a

growing number of studies have been focusing on resolving

the molecular mechanisms as well as on investigating the

effective therapeutic targets in the development of

melanoma.

Long non-coding RNAs (lncRNAs) are defined as non-

coding transcripts with over 200 nucleotides in length and

have been reported to play important roles in modulating

tumor genesis and progression [4–6]. Tian Y et al. have

explored the roles of abnormally expressed long non-cod-

ing RNA UCA1 and Malat-1 in metastasis of melanoma

and have discovered a possible correlation between the

increased expression of UCA1 and of Malat-1 lncRNAs

with melanoma metastasis [7]. However, the specific

molecular mechanisms remain to be further investigated.

miR-507 has been defined as a tumor suppressor for its

inhibitory effects in many cancer cells, including cervical

cancer, esophageal cancer, lung cancer and liver cancer [8].

Yanping Wei and Qianqian Sun have contributed equally to this work.

& Guoqiang Zhao

zhaogq@zzu.edu.cn

1 Department of Dermatology, The People’s Hospital of

Jiaozuo City, Jiaozuo 454000, Henan, China

2 School of Basic Medical Sciences, Zhengzhou University,

Zhengzhou 450001, Henan, China

3 Collaborative Innovation Center of Cancer

Chemoprevention, Zhengzhou 450001, Henan, China

123

Med Oncol (2016) 33:88

DOI 10.1007/s12032-016-0804-2

Schmitt AM et al. declared that lncRNAs drived many

important cancer phenotypes through their interactions

with other cellular macromolecules including DNA, pro-

tein and RNA [9]. UCA1 has been reported to promote

colorectal cancer via inhibiting miR-204-5p [10]. The pre-

experiment and bioinformatics analysis demonstrated that

miR-507 contained complementary binding sites for

lncRNA UCA1. Based on this finding, whether UCA1 and

miR-507 may closely interact in the regulation of mela-

noma is a topic that requires additional extensive research.

In our current research, we discovered a novel mecha-

nism through which UCA1 regulated miR-507. Addition-

ally, FOXM1 was verified as a new target of miR-507 in

regulating growth and invasion of melanoma.

Materials and methods

Clinical sample collection

After investigated by Ethics Committee of Life Sciences of

Zhengzhou University, the research content had been

confirmed to follow the requirements of the ethical stan-

dards about life sciences approved by International and

Chinese Ethics Committee. All patients were informed

about the aims of specimen collection and had signed

written consent. The tissues were collected during surgery

performed at the First Affiliated Hospital of Zhengzhou

University and People’s Hospital of Jiao Zuo, between

February 2013 and February 2015. Primary cutaneous

malignant melanoma tissues were obtained from 18

patients. And metastatic melanoma tissues were collected

from 19 patients. A total of 20 benign nevi obtained from

20 patients were defined as normal controls.

Cell culture

Human melanoma cell lines (A375 and SK-MEL-2) were

purchased from the Cell Bank of the Chinese Academy of

Sciences (Shanghai, China). Cells were cultured in DMEM

medium supplemented with 20 % fetal bovine serum (FBS)

in a 5 % CO2 atmosphere at 37 �C.

Cell transfection

Cells were seeded into six-well plates at a density of

5 9 104 cells/wells to reach about 50–80 % confluence for

transfection. siRNAs of UCA1 (si-UCA1) were designed

and synthesized by GenePharma (Shanghai, China). Tran-

sient transfection was conducted by LipofectamineTM 2000

(Invitrogen, Carlsbad, CA) following the manufactures’

instructions. Cells from each line were separated into five

groups: The si-UCA1 group was transfected with si-UCA1,

the miR-507 group was transfected with miR-507 mimics,

the co-transfection group (si-UCA1 ? miR-507) was

transfected with si-UCA1 and miR-507 mimics, the NC

group was transfected with scrambled oligonucleotide, and

the Blank group was not transfected. The transfected effi-

ciencies were examined by quantitative real-time PCR

(qRT-PCR).

RNA and miRNA extraction and quantitative RT-

PCR

Total RNA was extracted from the melanoma tissues and

A375 and SK-MEL-2 cells using Trizol reagent (Life

Technologies Corporation, Carlsbad, CA, USA). Reaction

mixture (20 ll) containing 1–3 lg of total RNA was

reversely transcribed to cDNA by using PrimeScript RT-

polymerase (Takara, Dalian, China). The quantitative PCR

was performed on the cDNA with specific primers for

UCA1 and FOXM1; the GAPDH was served as an internal

control. The stem-loop reverse transcriptase polymerase

chain reaction (RT-PCR) for miR-507 was measured with

the control of U6. And qRT-PCR was applied using the

ABI power SYBR� Green PCR Master Mix (Applied

Biosystems, Foster City, CA, USA). All process was per-

formed according to the manufactures’ instructions.

Cell proliferation assay

According to the manufacturers’ instructions, cell viability

was assessed using the Cell Counting Kit 8 (CCK-8;

Dojindo Molecular Technologies, Rockville, MD, USA) to

confirm whether the downregulation of si-UCA1 and

upregulation of miR-507 contributed to the inhibition of

cell proliferation. Cells were cultured into a 96-well plate

at a density of 0.5 9 104 cells/well at 37 �C, and the cell

viability was measured for different times (0 h, 24 h, 48 h

and 72 h) by a microplate reader (Model 680; Bio-Rad

Laboratories, Hercules, CA, USA) by spectrophotometry at

450 nm.

Invasion assay

Cell invasion assay was performed using the Transwell

insert chamber coated with Matrigel (BD Biosciences). The

transfected cells were resuspended in a 100-lL serum-free

medium at a density of 1 9 105 cells/mL and were added

to the upper chamber. The lower chamber was supplied

with 500 lL of DMEM/high-glucose or DMEM/F12

medium supplemented with 10 % FBS. After 24-h incu-

bation in a cell incubator at 37 �C, the cells on the top

surface of the insert were removed. Cells that had invaded

to the lower side of the membrane were fixed with

methanol and stained with 20 % Giemsa. The number of

88 Page 2 of 9 Med Oncol (2016) 33:88

123

cells was counted in five randomly chosen fields, and the

average number was calculated. Each test was performed in

triplicate.

Cell cycle analysis

The flow cytometry assay was performed to assess the cell

cycle distribution. 48 h after the cells transfection, cells

were stained with 20 lg/mL PI (Sigma-Aldrich, St Louis,

MO, USA) and 100 lg/mL RNase A in PBS for 15 min at

room temperature. A FACScan flow cytometer (BD Bio-

sciences, San Jose, CA) was used for the analysis.

Bioinformatics prediction and luciferase reporter

assay

A web-based program known as miRcode and the Tar-

getScan program were used to predict the target genes of

UCA1 and miR-507 and their conserved sites that match

the seed region. To construct the luciferase reporter vec-

tors, the entire UCA1 sequence (wild-type) was inserted

into the downstream of the pmirGLO promoter vector

(Promega, Madison, WI) and assigned as WT LncRNA

UCA1. The MT LncRNA UCA1 without the miR-507

binding sites was generated using QuikChange Multi Site-

Directed Mutagenesis kit (Stratagene, LaJolla, CA, USA).

The wild-type 30UTR of FOXM1 mRNA containing the

presumed target region for miR-507 was amplified by PCR.

The mutagenesis of the seed region was conducted with a

mutant primer. The WT FOXM1 30UTR and MT FOXM1

30UTR fragments were, respectively, inserted into the

pmirGLO promoter vector (Promega, Madison, WI)

downstream of the luciferase gene to generate recombinant

plasmids. When it comes to the luciferase reporter assay,

the cells were co-transfected using the LipofectamineTM

2000 (Invitrogen, Carlsbad, CA) according to the manu-

facturers’ instructions with miR-507 mimics and scrambled

oligonucleotide. After being treated for 24 h, the luciferase

activities were measured using the dual-luciferase reporter

assay system (Promega, Madison, WI, USA) according to

manufactures’ instructions.

RNA immunoprecipitation

A375 and SK-MEL-2 cells were lysed using a complete

RNA lysis buffer containing protease inhibitor and RNase

inhibitor using an EZ-Magna RIP RNA-binding protein

immunoprecipitation kit (Millipore, Billerica, MA, USA)

following the manufacturers’ instructions. 100 lL of whole

cell lysate was incubated with the RIP immunoprecipita-

tion buffer containing magnetic beads coated with human

anti-Argonaute 2 (Ago2) antibody (Millipore) and was

designated as the test group, while the control group

(Millipore) consisted of normal mouse IgG. After being

incubated for 2 h at 4 �C, the immunoprecipitated RNA

was isolated. The RNA concentration was measured by a

NanoDrop (Thermo Scientific), and the RNA quality was

determined using a bioanalyzer (Agilent, Santa Clara, CA,

USA). Next, the purified RNA was further used in the qRT-

PCR analysis of UCA1 and miR-507.

Western blotting

After 24-h transfection, total protein (50 lg) was extractedfrom the A375 and SK-MEL-2 cells using the RIPA buffer,

and the BCA Protein Assay Kit (Beyotime, China) was

then used to assess the protein concentrations. The sodium

dodecyl sulfate polyacrylamide gel electrophoresis (SDS-

PAGE) was performed to separate the objective protein

from the total protein. Polyvinylidene difluoride mem-

branes were used to be transferred. After being blocked in

5 % skim milk for 2 h and being washed four times with

TBST at room temperature, the membranes were incubated

with the primary antibody (polyclonal rabbit anti-human

FOXM1 antibody, Santa Cruz Biotechnology, Santa Cruz,

CA) overnight at 4 �C. Following four washes with TBST,

the membranes were incubated with the primary antibody

(horseradish peroxidase-conjugated goat anti-rabbit IgG,

Santa Cruz Biotechnology) for 2 h. A chemiluminescence

detection kit (Amersham Pharmacia Biotech, Piscataway,

NJ) was used to visualize all blots. The antibody against

GAPDH was used as control.

Statistical analysis

The data obtained from our experiments were presented as

mean ± standard deviation (SD) and analyzed using vari-

ance (ANOVA) test, student’s t test and Linear Regression

test that were a part of the SPSS software (version 21.0).

The qRT-PCR results were analyzed using the 2-DDCt

method. P\ 0.05 was considered statistically significant.

Results

LncRNA UCA1 and FOXM1 mRNA are

significantly upregulated in melanoma tumor tissues

The samples obtained from metastatic melanoma, primary

melanoma, melanocytic nevi, A375, and SK-MEL-2 cell

lines were examined to detect the expression of LncRNA

UCA1 and FOXM1 mRNA with the help of RT-PCR.

Compared with the melanocytic nevi tissues, upregulated

expression of UCA1 and FOXM1 mRNA was observed in

the metastatic melanoma and the primary melanoma tis-

sues, as well as in the A375 and SK-MEL-2 cell lines.

Med Oncol (2016) 33:88 Page 3 of 9 88

123

Besides, UCA1 and FOXM1 mRNA expressions were

significantly elevated in tissues without metastasis than in

tissues from patients without metastasis (P\ 0.05; Fig. 1a,

b). After statistical analysis of these data, the expression of

UCA1 and FOXM1 mRNA were found to be positively

related (R2 = 0.613, P\ 0.05; Fig. 1c).

Above all, UCA1 and FOXM1 expression was clearly

upregulated in the melanoma tumor tissues, and the

expression of UCA1 correlates positively with that of

FOXM1.

LncRNA UCA1 depletion suppresses cell

proliferation and invasion and induces cell cycle

arrest in A375 and SK-MEL-2 cell lines

Based on the above observations, UCA1 was found to be

upregulated in melanoma tumor tissues as well as in A375

and SK-MEL-2 cell lines. Then, we concentrated our

examination on the effect of UCA1 in melanoma cells. We

constructed a scrambled UCA1 and a siRNA-mediated

UCA1 depletion and transfected them separately into A375

and SK-MEL-2 cell lines. Successful transfection was

confirmed using qRT-PCR (Fig. 2a). CCK-8 assay was

used to evaluate the cell proliferation. After being cultured

for three days, cells transfected with si-UCA1 visibly

exhibited the lowest proliferation among the control groups

(P\ 0.05; Fig. 2b, c). The transwell assay was used to

detect the effect of UCA1 depletion on cell invasion. The

number of invasive cells decreased dramatically in cells

transfected with si-UCA1 (P\ 0.05; Fig. 2d). A cell cycle

analysis was conducted on the cells above using flow

cytometry. As a result, we found that the cells in the si-

UCA1 group had an arrested cell cycle with a lower pro-

portion of S-phase and G2/M-phase cells and a higher

proportion of G0/G1-phase cells, when compared to the

control groups (P\ 0.05; Fig. 2e). Taken together, it can

be reasonably concluded that the depletion of LncRNA

UCA1 depletion could suppress cell proliferation and cell

invasion and could also induce a G0/G1 cell cycle arrest in

A375 and SK-MEL-2 cell lines.

LncRNA UCA1 directly interacts with miR-507

in A375 and SK-MEL-2 cells

Numerous recent studies reported that lncRNAs has

sequence complementary to miRNAs that could potentially

have an inhibitory effect on miRNAs’ expression and

activity [11]. We then conducted a series of experiments in

order to examine whether UCA1 has an inhibitory effect on

miRNAs in melanoma cells. The miRcode program was

used and allowed us to observe the putative binding sites

between UCA1 and miR-507 (Fig. 3a). The level of miR-

507 and UCA1 were measured in the melanoma tissues by

qRT-PCR; the data obtained showed an inverse relation-

ship between them (R2 = 0.578, P\ 0.05; Fig. 3b). Fig-

ure 3c indicates that the depletion of UCA1 significantly

upregulated the expression level of miR-507 in A375 and

SK-MEL-2 cell lines (P\ 0.05). On the contrary, Fig. 3d

demonstrates that the overexpression of miR-507 notice-

ably inhibited the expression of UCA1 (P\ 0.05). More-

over, the luciferase reporter assay was conducted in order

to gain more insights into the relationship between UCA1

and miR-507 and revealed that while miR-507 repressed

the luciferase activity of WT LncRNA UCA1 (P\ 0.05;

Fig. 1 Expressions of LncRNA UCA1, FOXM1 in melanoma tumor

issues and cells as determined by quantitative real-time PCR (qRT-

PCR). a, b Relative expression levels of LncRNA UCA1 and FOXM1

in tissues of metastatic melanoma, primary melanoma and melano-

cytic nevi, as well as in A375 and SK-MEL-2 cell lines. c Linear

regression analysis of LncRNA UCA1 and FOXM1 expression in

tumor tissues from metastatic melanoma patients. *P\ 0.05

88 Page 4 of 9 Med Oncol (2016) 33:88

123

Fig. 3e), it did not affect the MT LncRNA UCA1 lucifer-

ase activity (P[ 0.05). In summary, it can be concluded

that miR-507 could directly bind to UCA1 at the miRNA

recognition site, and that there was a negative correlation

between miR-507 and UCA1. To more extensively analyze

the mechanism that might be involved in the reciprocal

relationship, RNA immunoprecipitation experiments were

taken using antibody against Ago2, a key component of

RISC complex. The results of our experiment indicated that

both miR-507 and UCA1 were in the Ago2-pulled down

pellet (Fig. 3f, g).

FOXM1 is a target of miR-507, and downregulated

FOXM1 plays a role in suppressing cell proliferation

and invasion and inducing cell cycle arrest in A375

and SK-MEL-2 cell lines

The overexpression of FOXM1 was examined in the mel-

anoma tissues and cell lines in earlier experiments. In

addition, TargetScan and miRanda prediction algorithms

showed that the FOXM1 might be targeted by miR-507

(Fig. 4a). A dual-luciferase reporter assay was performed,

with the results shown in Fig. 4b; from these results, we

were able to confirm what we had previously predicted.

Next, in order to explore the relationship among FOXM1,

UCA1 and miR-507, the A375 and SK-MEL-2 cells were

transfected with si-UCA1, miR-507 mimics, and a

combination of si-UCA1 and miR-507 mimics, while the

control cells were transfected with nothing. Western blot-

ting was performed in order to detect the protein expression

level of FOXM1; qPCR was used to evaluate the expres-

sion of FOXM1 mRNA. Compared with the control

groups, FOXM1 mRNA was significantly reduced in the si-

UCA1, miR-507 mimics and the combination of si-

UCA1and miR-507 mimics groups (P\ 0.05; Fig. 4c), the

protein expression exhibited the same trend (P\ 0.05;

Fig. 4d). Besides, the combination of si-UCA1 and miR-

507 mimics group had a distinctly higher expression level

than the si-UCA1 group (P\ 0.05) and the miR-507

mimics group (P\ 0.05). The behavior of the cells from

each of the five groups was examined by a CCK-8 assay, a

transwell assay and a flow cytometry. The outcomes of

these experiments and assays demonstrate that the down-

regulated UCA1 and the upregulated miR-507 could

reduce cell proliferation (P\ 0.05; Fig. 4e) and invasion

(P\ 0.05; Fig. 4f) and could also induce G0/G1 cell cycle

arrest (P\ 0.05; Fig. 4g). Furthermore, the group that

consisted of cells transfected with a combination of si-

UCA1 and miR-507 mimics showed a more profound

inhibitory effect than the other two groups (P\ 0.05).

To sum up, FOXM1 is a target of miR-507, and can be

downregulated by either miR-507 overexpression or UCA1

depletion. The results obtained from these in vitro experi-

ments suggest the existence of a UCA1-miR-507-FOXM1

Fig. 2 LncRNA UCA1 depletion suppresses cell proliferation and

invasion and induces cell cycle arrest in A375 and SK-MEL-2 cell

lines. a UCA1 expression levels were evaluated using qRT-PCR in si-

UCA1-transfected A375 and SK-MEL-2 cells. b, c cell proliferation

were detected in UCA1 downregulated cells using CCK-8 assay.

d transwell assay was performed in UCA1 downregulated cells to

investigate changes in cell invasiveness. e the cell cycle analysis wasdetected by flow cytometry. *P\ 0.05

Med Oncol (2016) 33:88 Page 5 of 9 88

123

coupling that could inhibit cell proliferation and cell

invasion, as well as induce a G0/G1 cell cycle arrest in

A375 and SK-MEL-2 cell lines.

Discussion

UCA1 has been reported as an oncogene and has been

found to be upregulated in various kinds of tumors [12].

For example, in non-small cell lung cancer, UCA1 func-

tions as an oncogene, acting mechanistically by upregu-

lating ERBB4 in part through ‘spongeing’ miR-193a-3p

[13]. UCA1 sustains proliferation of AML cells by

repressing the expression of the cell cycle regulator

p27kip1 [14]. In our experiments, UCA1 was verified to be

upregulated in melanoma tumor tissues and A375 and SK-

MEL-2 cell lines. Moreover, we discovered that UCA1

depletion could suppress cell proliferation and invasion and

could also induce G0/G1 cell cycle arrest in A375 and SK-

MEL-2 cell lines. The mechanisms that are involved in the

biological functions of UCA1 require more extensive

research.

Over the past several years, competing endogenous

RNAs (ceRNAs) have emerged as an important class of

post-transcriptional regulators that alter gene expression

through a miRNA-mediated mechanism [15]. Based on the

previous studies concerning the regulation of miRNA by

UCA1 [10, 16], we further explored the role and

Fig. 3 LncRNA UCA1 directly interacts with miR-507 in A375 and

SK-MEL-2 cells. a Predicted binding sites between UCA1 and miR-

507. b Linear regression analysis of LncRNA UCA1 and miR-507

expression in tumor tissues from metastatic melanoma patients.

c miR-507 levels were detected by qRT-PCR in A375 and SK-MEL-2

cells transfected with si-UCA1. d UCA1 levels were detected by

qRT-PCR in A375 and SK-MEL-2 cells transfected with miR-507

mimics. e The relative luciferase activities were inhibited in the A375

and SK-MEL-2 cells transfected with the reporter vector WT

LncRNA UCA1, not with the reporter vector MT LncRNA UCA1.

Association of miR-507 (f) and UCA1 (g) with Ago2 in A375 and

SK-MEL-2 cells. Cellular lysates from A375 and SK-MEL-2 cells

were used for RNA immunoprecipitation with antibody against Ago2.

UCA1 and miR-507 expression levels were detected using qRT-PCR.

Data were presented as mean ± SD from three independent exper-

iments. *P\ 0.05

88 Page 6 of 9 Med Oncol (2016) 33:88

123

mechanisms in which UCA1 exerts oncogenic functions by

targeting miRNAs. Bioinformatics analysis presented the

complementary binding sites between UCA1 and miR-507.

And the data obtained from melanoma tissues showed an

inverse expression trend between them. In the A375 and

SK-MEL-2 cell lines, knockdown of UCA1 (si-UCA1)

increased the expression of miR-507, while ectopic

expression of miR-507 decreased UCA1 expression. The

luciferase reporter assay was conducted to reveal that miR-

507 might be the target of UCA1; RNA immunoprecipi-

tation experiments were taken to show that miR-507 could

directly bind to UCA1 at the miRNA recognition site.

Therefore, we could confirm that there was a negative

correlation between miR-507 and UCA1.

The mammalian transcription factor forkhead box pro-

tein M1 (FOXM1) is an essential effector of G2/M-phase

Fig. 4 FOXM1 is a target of miR-507, and downregulated FOXM1

was analogous to UCA1 depletion and the overexpression of miR-

507. a Predicted binding sites between FOXM1 and miR-507. b The

relative luciferase activities were inhibited in the A375 and SK-MEL-

2 cells transfected with the reporter vector WT FOXM1 30UTR, notwith the reporter vector MT FOXM1 30UTR. c Western blotting

indicated that the FOXM1 protein expression was downregulated in

A375 and SK-MEL-2 cells transfected with si-UCA1, miR-507

mimics and the combination of si-UCA1 and miR-507 mimics,

respectively. d A375 and SK-MEL-2 cells were divided into five

groups including si-NC group, miR-NC group, si-UCA1 group, miR-

507 mimics group and the combination of si-UCA1and miR-507

mimics group. The level of FOXM1 mRNA was examined by qRT-

PCR. e cell proliferation were detected using CCK-8 assay. f transwellassay was performed to investigate changes in cell invasiveness. g the

cell cycle analysis was detected by flow cytometry. *P\ 0.05

Med Oncol (2016) 33:88 Page 7 of 9 88

123

transition, mitosis and the DNA damage response [17].

Large quantities of reports have revealed that FOXM1 can

serve as downstream target of miRNA and then participate

in biological functions of the process of cancers. For

example, miR-204 inhibits invasion and epithelial-mes-

enchymal transition by targeting FOXM1 in esophageal

cancer [18]. miR-671-5p inhibits epithelial-to-mesenchy-

mal transition by downregulating FOXM1 expression in

breast cancer [19]. MicroRNA-802 suppresses breast can-

cer proliferation through downregulation of FOXM1 [20].

What’s more, FOXM1 has been verified to be upregulated

in melanoma cells [21] and considered to be a new thera-

peutic target for melanoma [22]. In our experiments, the

level of FOXM1 mRNA was detected to be overexpressed

in melanoma tissues and cells. Bioinformatics analysis and

the dual-luciferase reporter assay were performed to

describe the possibility that FOXM1 would be a target of

miR-507. Next, the data obtained from our studies

demonstrated that FOXM1 can be downregulated by either

miR-507 overexpression or UCA1 depletion, and that

downregulated FOXM1 plays an important role in sup-

pressing cell proliferation, invasion and in inducing cell

cycle arrest in A375 and SK-MEL-2 cell lines.

In conclusion, there exists a UCA1-miR-507-FOXM1

coupling that could inhibit cell proliferation and invasion

and could also induce G0/G1 cell cycle arrest in A375 and

SK-MEL-2 cell lines. A recent study by Sarkar D et al. [23]

has identified lncRNAs, as well as miRNAs, play crucial

roles in epigenetic control with diverse modes action and

functional consequences and the tissue specificities of

miRNAs and lncRNAs make them good candidates for use

as markers for early diagnosis of melanoma. As a result,

our finding might provide some useful evidence about the

lncRNA interaction regulatory network in tumorigenesis of

melanoma, thus it could be argued the UCA1-miR-507-

FOXM1 system may become a new epigenetic therapeutic

target for melanoma treatment.

Acknowledgments The authors are grateful to all staff at the study

center who contributed to this study. This study was supported by a

Grant from the Education Agency of Henan (No. 13A310671).

Compliance with ethical standards

Conflict of interest The authors declare no conflict of interest or

financial disclosures of this study.

References

1. Aladowicz E, Ferro L, Vitali GC, Venditti E, Fornasari L, Lan-

francone L. Molecular networks in melanoma invasion and

metastasis. Future Oncol. 2013;9(5):713–26.

2. Rahib L, Smith BD, Aizenberg R, Rosenzweig AB, Fleshman

JM, Matrisian LM. Projecting cancer incidence and deaths to

2030: the unexpected burden of thyroid, liver, and pancreas

cancers in the United States. Cancer Res. 2014;74(11):2913–21.

3. Weinstein D, Leininger J, Hamby C, Safai B. Diagnostic and

prognostic biomarkers in melanoma. J Clin Aesthet Dermatol.

2014;7(6):13–24.

4. Cao B, Song N, Zhang M, Di C, Yang Y, Lu Y, et al. Systematic

study of novel lncRNAs in different gastrointestinal cancer cells.

Discov Med. 2016;21(115):159–71.

5. Sand M, Bechara FG, Sand D, Gambichler T, Hahn SA, Bromba

M, et al. Expression profiles of long noncoding RNAs in cuta-

neous squamous cell carcinoma. Epigenomics. 2016;8(4):501–18.

6. Deng W, Wang J, Zhang J, Cai J, Bai Z, Zhang Z. TET2 regulates

LncRNA-ANRIL expression and inhibits the growth of human

gastric cancer cells. IUBMB Life. 2016;68(5):355–64.

7. Tian Y, Zhang X, Hao Y, Fang Z, He Y. Potential roles of

abnormally expressed long noncoding RNA UCA1 and Malat-1

in metastasis of melanoma. Melanoma Res. 2014;24(4):335–41.

8. Yamamoto S, Inoue J, Kawano T, Kozaki K, Omura K, Inazawa

J. The impact of miRNA-based molecular diagnostics and treat-

ment of NRF2-stabilized tumors. Mol Cancer Res. 2014;12(1):

58–68.

9. Schmitt AM, Chang HY. Long Noncoding RNAs in Cancer

Pathways. Cancer Cell. 2016;29(4):452–63.

10. Bian Z, Jin L, Zhang J, Yin Y, Quan C, Hu Y, et al. LncRNA-

UCA1 enhances cell proliferation and 5-fluorouracil resistance in

colorectal cancer by inhibiting miR-204-5p. Sci Rep. 2016;6

(23892):9.

11. Liu XH, Sun M, Nie FQ, Ge YB, Zhang EB, Yin DD, et al. Lnc

RNA HOTAIR functions as a competing endogenous RNA to

regulate HER2 expression by sponging miR-331-3p in gastric

cancer. Mol Cancer. 2014;13:92.

12. Li Y, Wang T, Li Y, Chen D, Yu Z, Jin L, et al. Identification of

long-non coding RNA UCA1 as an oncogene in renal cell car-

cinoma. Mol Med Rep. 2016;13(4):3326–34.

13. Nie W, Ge HJ, Yang XQ, Sun X, Huang H, Tao X, et al.

LncRNA-UCA1exerts oncogenic functions in non-small cell

lungcancerby targeting miR-193a-3p. Cancer Lett. 2016;371(1):

99–106.

14. Hughes JM, Legnini I, Salvatori B, Masciarelli S, Marchioni M,

Fazi F, et al. C/EBPa-p30 protein induces expression of the

oncogenic long non-coding RNA UCA1 in acute myeloid leu-

kemia. Oncotarget. 2015;6(21):18534–44.

15. Wang Y, Hou J, He D, Sun M, Zhang P, Yu Y, et al. The

emerging function and mechanism of ceRNAs in Cancer. Trends

Genet. 2016;32(4):211–24.

16. Tuo YL, Li XM, Luo J. Long noncoding RNA UCA1 modulates

breast cancer cell growth and apoptosis through decreasing tumor

suppressive miR-143. Eur Rev Med Pharmacol Sci. 2015;19(18):

3403–11.

17. Myatt SS, Kongsema M, Man CW, Kelly DJ, Gomes AR,

Khongkow P, et al. SUMOylation inhibits FOXM1 activity and

delays mitotic transition. Oncogene. 2014;33(34):4316–29.

18. Sun Y, Yu X, Bai Q. miR-204 inhibits invasion and epithelial-

mesenchymal transition by targeting FOXM1 in esophageal

cancer. Int J Clin Exp Pathol. 2015;8(10):12775–83.

19. Tan X, Fu Y, Chen L, Lee W, Lai Y, Rezaei K, et al. miR-671-5p

inhibits epithelial-to-mesenchymal transition by downregulating

FOXM1 expression in breast cancer. Oncotarget. 2016;7(1):293–

307.

20. Yuan F, Wang W. MicroRNA-802 suppresses breast cancer

proliferation through downregulation of FoxM1. Mol Med Rep.

2015;12(3):4647–51.

21. Ito T, Kohashi K, Yamada Y, Maekawa A, Kuda M, Furue M,

et al. Prognostic significance of Forkhead box M1 (FOXM1)

expression and antitumor effect of FOXM1 inhibition in mela-

noma. Histopathology. 2016;69(1):63–71.

88 Page 8 of 9 Med Oncol (2016) 33:88

123

22. Miyashita A, Fukushima S, Nakahara S, Yamashita J, Tokuzumi

A, Aoi J, et al. Investigation of FOXM1 as a potential new target

for melanoma. Plos One. 2015;10(12):e0144241.

23. Sarkar D, Leung EY, Baguley BC, Finlay GJ, Askarian-Amiri

ME. Epigenetic regulation in human melanoma: past and future.

Epigenetics. 2015;10(2):103–21.

Med Oncol (2016) 33:88 Page 9 of 9 88

123

本文献由“学霸图书馆-文献云下载”收集自网络，仅供学习交流使用。

学霸图书馆（www.xuebalib.com）是一个“整合众多图书馆数据库资源，

提供一站式文献检索和下载服务”的24 小时在线不限IP

图书馆。

图书馆致力于便利、促进学习与科研，提供最强文献下载服务。

图书馆导航：

图书馆首页 文献云下载 图书馆入口 外文数据库大全 疑难文献辅助工具