Long non-coding RNA BCAR4 promotes chondrosarcoma cell proliferation and migration through activation of mTOR signaling pathway

Cancer fusion transcripts with human non-coding RNAs

Cancer chimeric, or fusion, transcripts are thought to most frequently appear due to chromosomal aberrations that combine moieties of unrelated normal genes. When being expressed, this results in chimeric RNAs having upstream and downstream parts relatively to the breakpoint position for the 5'- and 3'-fusion components, respectively. As many other types of cancer mutations, fusion genes can be of either driver or passenger type. The driver fusions may have pivotal roles in malignisation by regulating survival, growth, and proliferation of tumor cells, whereas the passenger fusions most likely have no specific function in cancer. The majority of research on fusion gene formation events is concentrated on identifying fusion proteins through chimeric transcripts. However, contemporary studies evidence that fusion events involving non-coding RNA (ncRNA) genes may also have strong oncogenic potential. In this review we highlight most frequent classes of ncRNAs fusions and summarize current understanding of their functional roles. In many cases, cancer ncRNA fusion can result in altered concentration of the non-coding RNA itself, or it can promote protein expression from the protein-coding fusion moiety. Differential splicing, in turn, can enrich the repertoire of cancer chimeric transcripts, e.g. as observed for the fusions of circular RNAs and long non-coding RNAs. These and other ncRNA fusions are being increasingly recognized as cancer biomarkers and even potential therapeutic targets. Finally, we discuss the use of ncRNA fusion genes in the context of cancer detection and therapy.

Epigenetic Abnormalities in Chondrosarcoma

In recent years, our understanding of the epigenetic mechanisms involved in tumor pathology has improved greatly. DNA and histone modifications, such as methylation, demethylation, acetylation, and deacetylation, can lead to the up-regulation of oncogenic genes, as well as the suppression of tumor suppressor genes. Gene expression can also be modified on a post-transcriptional level by microRNAs that contribute to carcinogenesis. The role of these modifications has been already described in many tumors, e.g., colorectal, breast, and prostate cancers. These mechanisms have also begun to be investigated in less common tumors, such as sarcomas. Chondrosarcoma (CS) is a rare type of tumor that belongs to sarcomas and is the second most common malignant bone tumor after osteosarcoma. Due to unknown pathogenesis and resistance to chemo- and radiotherapies of these tumors, there is a need to develop new potential therapies against CS. In this review, we summarize current knowledge on the influence of epigenetic alterations in the pathogenesis of CS by discussing potential candidates for future therapies. We also emphasize ongoing clinical trials that use drugs targeting epigenetic modifications in CS treatment.

The Roles of Noncoding RNAs in the Development of Osteosarcoma Stem Cells and Potential Therapeutic Targets

Osteosarcoma (OS) is the common bone tumor in children and adolescents. Because of chemotherapy resistance, the OS patients have a poor prognosis. The one reason of chemotherapeutic resistance is the development of cancer stem cells (CSCs). CSCs represent a small portion of tumor cells with the capacity of self-renewal and multipotency, which are associated with tumor initiation, metastasis, recurrence and drug resistance. Recently, noncoding RNAs (ncRNAs) have been reported to critically regulate CSCs. Therefore, in this review article, we described the role of ncRNAs, especially miRNAs, lncRNAs and circRNAs, in regulating CSCs development and potential mechanisms. Specifically, we discussed the role of multiple miRNAs in targeting CSCs, including miR-26a, miR-29b, miR-34a, miR-133a, miR-143, miR-335, miR-382, miR-499a, miR-1247, and let-7days. Moreover, we highlighted the functions of lncRNAs in regulating CSCs in OS, such as B4GALT1-AS1, DANCR, DLX6-AS1, FER1L4, HIF2PUT, LINK-A, MALAT1, SOX2-OT, and THOR. Due to the critical roles of ncRNAs in regulation of OS CSCs, targeting ncRNAs might be a novel strategy for eliminating CSCs for OS therapy.

The role of long non-coding RNA BCAR4 in human cancers

Long non-coding RNA (lncRNA) is a type of non-coding RNA with length of nucleotides > 200 bp. Increasing evidences show that lncRNA breast cancer antiestrogen resistance 4 (BCAR4) plays an important role in the occurrence and development of various human cancers. It is found that BCAR4 is highly expressed in diverse tumor tissues and cells, and the high expression of BCAR4 is usually associated with poor prognosis. BCAR4 is considered as an oncogene in human cancers. By competing endogenous RNA (ceRNA) mechanism and regulating different signaling pathways, BCAR4 participates in the proliferation, apoptosis, migration, invasion, epithelial-mesenchymal transition (EMT), metastasis and tumorigenesis of different cancers. In addition, overexpression of BCAR4 promotes drug resistance of tumor cells. Therefore, BCAR4 is a promising biomarker for cancer diagnosis and prognosis, and it is a potential target for cancer therapy. This paper reviews studies focusing on the relationship between BCAR4 and cancers in recent years and aims to summarize the effect and mechanism of BCAR4 in human cancers.

MicroRNA-486-5p Suppresses Lung Cancer via Downregulating mTOR Signaling In Vitro and In Vivo

Lung cancer is one of the central causes of tumor-related deaths globally, of which non-small cell lung cancer (NSCLC) takes up about 85%. As key regulators of various biological processes, microRNAs (miRNAs) have been verified as crucial factors in NSCLC. To elucidate the role of miR-486-5p in the mTOR pathway, we investigated its role in NSCLC and related signaling. Our results confirmed that miR-486-5p was downregulated in most of human NSCLC tissue samples and cell lines. Further study confirmed that it inhibited NSCLC through repression of the mTOR pathway via targeting both ribosomal proteins S6 kinase A1 (RPS6KA1, RSK) and ribosomal proteins S6 kinase B1 (RPS6KB1, p70S6K), which are critical components of the mTOR signaling. Additionally, miR-486-5p impeded tumor growth in vivo and inhibited tumor metastasis through repression of the epithelial-mesenchymal transition (EMT). Taken together, our study verified the role that miR-486-5p exerts in NSCLC, and its expression pattern in the different stages and morphologies of NSCLC makes it a promising biomarker in the early diagnosis of the disease.

SP1-induced long non-coding RNA SNHG6 facilitates the carcinogenesis of chondrosarcoma through inhibiting KLF6 by recruiting EZH2

Small nucleolar RNA host gene 6 (SNHG6) is a newly discovered long non-coding RNA (lncRNA), while the regulatory mechanism of SNHG6 in chondrosarcoma is largely unknown. Here we found that SNHG6 expression was upregulated and showed positive correlation with the progression of chondrosarcoma. Functional assays demonstrated that SNHG6 was required for the proliferation, migration, and invasion of chondrosarcoma cells. Mechanistic study revealed that SNHG6 could recruit EZH2 and maintain high level of H3K27me3 to repress the transcription of tumor-suppressor genes, including KLF6. KLF6 was found to bind to the promoter region of SP1 and restrained its transcription, while SP1 could be recruited to the promoter region of SNHG6 and promoted its transcription to form a positive loop. In summary, this study reveals that SP1-induced SNHG6 forms a positive loop to facilitate the carcinogenesis of chondrosarcoma through the suppression of KLF6 by recruiting EZH2, which manifests the oncogenic function of SNHG6 in chondrosarcoma.

LncRNA, Important Player in Bone Development and Disease

BACKGROUND

Bone is an important tissue and its normal function requires tight coordination of transcriptional networks and signaling pathways, and many of these networks/ pathways are dysregulated in pathological conditions affecting cartilage and bones. Long non-coding RNA (lncRNA) refers to a class of RNAs with a length of more than 200 nucleotides, lack of protein-coding potential, and exhibiting a wide range of biological functions. Although studies on lcnRNAs are still in their infancy, they have emerged as critical players in bone biology and bone diseases. The functions and exact mechanism of bone-related lncRNAs have not been fully classified yet.

OBJECTIVE

The objective of this article is to summarize the current literature on lncRNAs on the basis of their role in bone biology and diseases, focusing on their emerging molecular mechanism, pathological implications and therapeutic potential.

DISCUSSION

A number of lncRNAs have been identified and shown to play important roles in multiple bone cells and bone disease. The function and mechanism of bone-related lncRNA remain to be elucidated.

CONCLUSION

At present, majority of knowledge is limited to cellular levels and less is known on how lncRNAs could potentially control the development and homeostasis of bone. In the present review, we highlight some lncRNAs in the field of bone biology and bone disease. We also delineate some lncRNAs that might have deep impacts on understanding bone diseases and providing new therapeutic strategies to treat these diseases.

Variant in BCAR4 gene correlated with the breast cancer susceptibility and mRNA expression of lncRNA BCAR4 in Chinese Han population

BACKGROUND

Long non-coding RNA (LncRNA) Breast cancer anti-estrogen resistance 4 (BCAR4) has been shown to participate in the biological progress of various cancers including breast cancer. Genetic Polymorphisms in BCAR4 may have an influence on the progress of breast cancer, but it is rarely studied.

METHODS

In our epidemiology study, three tagging SNPs (rs4561483, rs11649623 and rs13334967) in lncRNA BCAR4 were selected for genotyping among 487 breast cancer cases and 489 healthy controls. And quantitative real-time PCR (qRT-PCR) was performed to evaluate the relative mRNA expression of BCAR4 in different genotypes of the significant locus rs13334967.

RESULTS

We found that BCAR4 rs13334967 is associated with lower breast cancer risk both in codominant model (AT vs AA, OR 0.632, 95% CI 0.429-0.931, TT vs AA, OR 0.731, 95% CI 0.511-0.990) and dominant model (AT + TT vs AA, OR 0.798, 95% CI 0.571-0.970). The further results of qRT-PCR displayed that carriers with rs13334967 AT, TT genotype have lower BCAR4 mRNA expression compared with AA genotype.

CONCLUSION

The research study implied that BCAR4 rs13334967 was correlated with the susceptibility to breast cancer and may impact the mRNA expression of BCAR4. LncRNA BCAR4 may be a potential biomarker and therapeutic target for breast cancer.

Long non-coding RNA BCAR4 promotes liver cancer progression by regulating proliferation, migration and invasion

Liver cancer (LC) is one of the primary contributors of cancer-associated death worldwide. Long non-coding RNAs (lncRNAs) have been shown to participate in almost every aspect of cell biology and serve fundamental roles in carcinogenesis and cancer progression, including in LC. However, the clinical significance and functional role of the lncRNA breast cancer anti-estrogen resistance 4 (BCAR4) in LC have not yet been identified. The present study measured the expression levels of BCAR4 in LC cells and tissues, and discovered that BCAR4 was upregulated in LC tissues compared with adjacent normal tissues. Furthermore, high BCAR4 expression was associated with the presence of multiple tumors and advanced Tumor-Node-Metastasis stages (III/IV). Survival analysis found that high BCAR4 expression indicated poor overall survival (OS) and progression-free survival (PFS). By analyzing the risk factors of poor OS and PFS using univariate analysis and multivariate analysis, high BCAR4 expression was revealed to be an independent risk factor of poor prognosis. In addition, the role of BCAR4 was further investigated in vitro, which revealed overexpression of BCAR4 to markedly promote the proliferation, migration and invasion of LC cells. Conversely, the loss of BCAR4 expression repressed the proliferation, migration and invasion of LC cells. In conclusion, BCAR4 is overexpressed in LC and is associated with LC progression. Therefore, BCAR4 may be used as a potential prognostic marker in LC.

Investigating the role of BCAR4 in ovarian physiology and female fertility by genome editing in rabbit

Breast Cancer Anti-estrogen Resistance 4 (BCAR4) was previously characterised in bovine species as a gene preferentially expressed in oocytes, whose inhibition is detrimental to in vitro embryo development. But its role in oogenesis, folliculogenesis and globally fertility in vivo remains unknown. Because the gene is not conserved in mice, rabbits were chosen for investigation of BCAR4 expression and function in vivo. BCAR4 displayed preferential expression in the ovary compared to somatic organs, and within the ovarian follicle in the oocyte compared to somatic cells. The transcript was detected in follicles as early as the preantral stage. Abundance decreased throughout embryo development until the blastocyst stage. A lineage of genome-edited rabbits was produced; BCAR4 expression was abolished in follicles from homozygous animals. Females of wild-type, heterozygous and homozygous genotypes were examined for ovarian physiology and reproductive parameters. Follicle growth and the number of ovulations in response to hormonal stimulation were not significantly different between genotypes. Following insemination, homozygous females displayed a significantly lower delivery rate than their heterozygous counterparts (22 ± 7% vs 71 ± 11% (mean ± SEM)), while prolificacy was 1.8 ± 0.7 vs 6.0 ± 1.4 kittens per insemination. In conclusion, BCAR4 is not essential for follicular growth and ovulation but it contributes to optimal fertility in rabbits.

Long Non-Coding RNA BCAR4 Promotes Growth, Invasion and Tumorigenicity by Targeting miR-2276 to Upregulate MMP7 Expression in Glioma

Objective

Long non-coding RNA breast cancer anti-estrogen resistance 4 (BCAR4) has been recognized as a proto-oncogene in various malignancies. It has been reported to be highly expressed and promote cell proliferation in glioma. However, its additional roles in gliomagenesis remain largely unclear. This research intends to investigate the impact and internal molecular mechanism of BCAR4 on glioma cell growth, invasion and tumorigenesis.

Methods

BCAR4 expression was examined by qPCR in 30 cases of graded glioma specimens and 7 glioblastoma (GBM) cell lines compared with respective controls. Its potential prognostic value was evaluated by Kaplan-Meier survival analysis. The biological roles of BCAR4 in gliomagenesis were verified by CCK-8, transwell and intracranial xenograft assays successively. qPCR and RNA pull-down assays were applied to study the relationship between BCAR4 and miR-2276. Then, qPCR, Western blot and luciferase reporter assays were used to validate the targeting of matrix metallopeptidase 7 (MMP7) by miR-2276 and the regulation of MMP7 by BCAR4. Finally, MMP7 was restored in BCAR4-silenced GBM cells and the rescue effects were determined by CCK-8 and transwell assays.

Results

BCAR4 expression was increased in glioma tissues and GBM cell lines, and its high expression positively correlated with advanced grades and worse prognosis. Functional assays verified that knockdown of BCAR4-inhibited cell growth and invasion in vitro, and impaired tumor formation in vivo. Mechanistically, we found that BCAR4 could act as a competing endogenous RNA (ceRNA) by targeting miR-2276 to upregulate MMP7 expression. Importantly, MMP7 restoration effectively rescued the inhibitory modulations on GBM cell growth and invasion caused by BCAR4 knockdown.

Conclusion

Our findings identified the essential roles of the BCAR4/miR-2276/MMP7 axis in gliomagenesis and provided novel insights on glioma therapy.

The Value of LncRNA BCAR4 as a Prognostic Biomarker on Clinical Outcomes in Human Cancers

Background: This updated meta-analysis aimed to analyze available data to explore the prognostic value of long noncoding RNA breast cancer anti-estrogen resistance 4 (BCAR4) in various human malignancies. Methods: Literature retrieval was performed by systematic searching several authoritative databases, including Pubmed, PMC database, Web of Science, the Cochrane Library, Embase, and CNKI database up to Feb 10, 2019. Data were extracted and subsequently crosschecked, and discrepancies were discussed to reach consensus. Quality of the eligible studies was evaluated by Newcastle-Ottawa Scale (NOS). The fixed- or random-effects model was used to calculate the pooled the hazard ratios (HRs) or odds ratios (ORs) and the 95% confidence interval (95% CI). Publication bias was detected by using Begg's funnel plot and Egger's test. Results: A total 1,128 cancer patients from thirteen studies were included and pooled in the present meta-analysis. High expression levels of BCAR4 were correlated with unfavorable overall survival (OS) (HR=2.23, 95% CI: 1.84-2.71), but not progression-free survival (PFS) (HR=1.30, 95% CI: 0.80-2.11). Subgroup stratified analysis showed that tumor type, sample size, follow-up months, and survival analysis method did not alter the predictive value of BCAR4 on OS in various cancers. Furthermore, elevated BCAR4 level was markedly correlated with advanced clinical stage (III/IV) (OR=3.28, 95% CI: 2.33-4.60), and dramatically predicted lymph node metastasis (OR=3.00, 95% CI: 1.95-4.63, P<0.00001) and distant metastasis (OR=3.36, 95% CI: 1.88-5.98, P<0.0001), but not associated with age, gender or tumor size. No obvious heterogeneity was noted for correlation between BCAR4 expression and OS across these studies. Conclusions: High expression of BCAR4 was correlated with unfavorable overall survival outcome and clinical features including metastasis and progression, implicating an independent prognostic value for BCAR4 in human cancers.

Prognostic value of long non-coding RNA breast cancer anti-estrogen resistance 4 in human cancers: A meta-analysis

BACKGROUND

Since long non-coding RNA breast cancer anti-estrogen resistance 4 (lncRNA BCAR4) is dysregulated in various types of cancers, we conducted a meta-analysis to determine its prognostic value in cancer.

METHODS

PubMed, EMBASE database, and CENTRAL were systematically searched.Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were collected to estimate the prognostic value. Odds ratios (ORs) and their 95% CIs were used to assess the association between lncRNA BCAR4 expression and clinicopathological features, including tumor size, differentiation, lymph node metastasis, distant metastasis, and tumor stage.

RESULTS

Ten studies with 890 patients were included in this meta-analysis. The pooled results indicated that high lncRNA BCAR4 expression was associated with poor overall survival (OS) (HR 2.80, 95% CI: 2.08-3.78; P < .001). Overexpression of lncRNA BCAR4 was related to lymph node metastasis (OR 3.68, 95% CI: 2.25-6.00; P < .001), high tumor stage (OR 3.19, 95% CI: 1.98-5.13; P < .001), and distant metastasis (OR 3.83, 95% CI: 2.15-6.82; P < .001), but not to tumor size.

CONCLUSIONS

Therefore, lncRNA BCAR4 overexpression is associated with poor OS and advanced clinicopathological features, and lncRNA BCAR4 may be a novel prognostic biomarker in cancer patients. However, further high-quality studies are needed to confirm these findings.

Lycopene upregulates ZO-1 and downregulates claudin-1 through autophagy inhibition in the human cutaneous squamous cell carcinoma cell line COLO-16

Lycopene, a kind of carotenoid, has been reported to have an inhibitory function on tumor cell migration. However, the potential role of lycopene in the treatment of cutaneous squamous cell carcinoma (cSCC) remains unclear. Therefore, we assessed the biological effects of lycopene in the human cSCC cell line COLO-16, human epidermal keratinocytes (HEKs) and the immortalized human keratinocyte cell line HaCaT. We found that lycopene inhibited the cell proliferation and migration of COLO-16 cells but not normal keratinocytes. In addition, lycopene upregulated the protein levels of ZO-1 in COLO-16 and HaCaT cells but not in HEKs. In contrast, lycopene upregulated the protein level of claudin-1 in HEKs but downregulated claudin-1 in COLO-16 cells. Lycopene led to a decrease in autophagic flux in COLO-16 cells in a mechanistic target of rapamycin complex 1 (MTORC1)-dependent manner. Importantly, autophagy inhibition contributed to the lycopene-induced regulation on ZO-1 and claudin-1 in COLO-16 cells. Moreover, JNK inhibitor (SP600125) and MEK inhibitor (U0126) treatment abolished the increase in phosphorylated MTOR and ribosomal protein S6 as well as the increase in ZO-1 and the decrease in claudin-1 in lycopene-treated COLO-16 cells. Gene silencing of JNK and ERK also prohibited ZO-1 upregulation and claudin-1 downregulation. In conclusion, lycopene upregulates ZO-1 expression and downregulates claudin-1 expression through the activation of ERK, JNK and MTORC1 as well as the inhibition of autophagy in human cSCC cells. Our findings demonstrate that autophagy plays a key role in lycopene-mediated pharmacological effects. This study indicates that lycopene might be a useful chemopreventive agent against cSCC.

Long noncoding RNA Breast cancer antiestrogen resistance 4 is associated with cancer progression and its significant prognostic value

Breast cancer antiestrogen resistance 4 (BCAR4) is a novel long noncoding RNA. It was originally identified in a screen for genes responsible for the development of resistance to antiestrogens in breast cancer cells and plays a major role in various tumors. However, the clinical diagnostic role of BCAR4 in tumors is not completely understood. This current meta-analysis aimed to comprehensively explore the potential role of BCAR4 as a prognostic biomarker in a number of cancers. Five public databases PubMed, EMBASE, Web of Science, Wiley Online Library, and Medline were used to search for articles. Nine studies comprising 1,293 patients were included in this meta-analysis. The results of analysis showed that BCAR4 expression in human cancer was significantly associated with poor overall survival (hazard ratio [HR] = 1.98, confidence interval [CI]: [1.71-2.29]), p < 0.00001, and high BCAR4 expression was associated with clinical stage (OR and its 95% CI was 3.30 [1.99-5.46], p < 0.00001), distant metastasis (OR = 3.83, 95% CI: 2.15-6.82, p < 0.00001), and lymph node metastasis (OR and its 95% CI was 2.91 [1.62-5.25], p = 0.0004) in patients with cancer. Furthermore, the results revealed the prognostic significance of BCAR4 in gastrointestinal malignancy, breast cancer, and osteosarcoma (HR and its 95% CI were 2.05 [1.56-2.68], p < 0.00001; 1.78 [1.46-2.16], p < 0.00001; and 2.47 [1.41-4.34], p < 0.00001, respectively). This meta-analysis indicated the potential value of BCAR4 as a biomarker for predicting a poor prognosis in patients with cancer.

Effect of silencing lncRNATUG1 on rapamycin-induced inhibition of endothelial cell proliferation and migration

Angiogenesis refers to the formation of new blood vessels from existing blood vessels. The proliferation and migration of endothelial cells serves a key function in this process. Previous research has demonstrated that rapamycin suppresses endothelial cell proliferation and migration, as well as angiogenesis. However, the mechanism by which rapamycin inhibits the proliferation and migration of endothelial cells remains unclear. Long noncoding RNAs (lncRNAs) serve a key function in the regulation of endothelial cell function. The aim of the current study was to investigate whether lncRNA taurine upregulated 1 (lncRNATUG1) is involved in rapamycin-induced inhibition of proliferation and migration in human umbilical vein endothelial cells (HUVECs). Reverse transcription quantitative polymerase chain reaction results indicated that the expression of lncRNATUG1 was upregulated in HUVECs that had been cultured with rapamycin. Subsequently, HUVECs were transfected with siRNAs and CCK-8 assays were performed to detect cell proliferation; additionally, flow cytometry was employed to detect cell apoptosis, and wound healing assays were performed to investigate cell migration. The results demonstrated that rapamycin suppressed the proliferation and migration of HUVECs, and promoted the apoptosis of HUVECs. In addition, rapamycin downregulated the expression of vascular endothelial growth factor (VEGF), matrix metalloproteinase (MMP)-2 and MMP-9 in HUVECs. However, silencing of lncRNATUG1 was revealed to attenuate rapamycin-induced inhibition of cellular proliferation and migration of HUVECs, as well as upregulating the expression of VEGF, MMP2 and MMP-9. These results suggested that lncRNATUG1 regulates rapamycin-induced inhibition of endothelial cell proliferation and migration. Therefore, lncRNATUG1 may serve a key function in rapamycin-induced inhibition of endothelial cell proliferation and migration.

Long Non-Coding RNA HULC Promotes Progression of Bone Neoplasms

Background

Bone neoplasms are common in humans and have high lethality. Recently, great progress has been made in understanding the pathophysiological mechanisms, but little is known about the molecular and genetic networks involved.

Material/Methods

qRT-PCR assays were conducted to detect the expression levels of lncRNA HULC in various cell lines. MTT assay, Transwell assay, and wound-healing assay were performed to investigate the proliferation speed, invasion ability, and migration ability of each cell line, respectively. Western blot analysis was also done to assess the expression level of EMT-related factors. Statistical analysis was performed using the t test, Kaplan-Meier method, and log-rank test.

Results

Compared to the human normal bone cell line, we found lncRNA HULC was over-expressed in all 6 bone neoplasm cell lines, and we finally chose HT1080 and Saos-2 cell lines, which possessed the highest lncRNA HULC expression level, for the subsequent studies. We then observed that the expression level of lncRNA HULC was negatively correlated with overall survival rate of bone neoplasm patients, which means that lncRNA HULC has prognostic value in patients with bone neoplasms. Thus, we assessed the influence of lncRNA HULC down-regulation on proliferation, invasion, and migration abilities of bone neoplasm cells, and found a significant decrease in these abilities. Finally, we found that down-regulating lncRNA HULC led to decreased expression of EMT-related factors in bone neoplasm cells.

Conclusions

LncRNA HULC can promote the tumorigenesis of bone neoplasms through increasing the proliferation, invasion, and migration abilities and the expression level of EMT-related factors.

Up-regulated BCAR4 contributes to proliferation and migration of cervical cancer cells

OBJECTIVES

Recently, thousands of long non-coding RNAs (lncRNAs) involved in development and metastasis of malignant tumors have been identified. Long non-coding RNA (lncRNA) breast cancer anti-estrogen resistance 4 (BCAR4) has been proved to promote proliferation and metastasis in multiple tumors. However, the function and significance of BCAR4 in cervical cancer are still unclear.

METHODS

In this study, we concentrated on the biological function and clinical significance of BCAR4 in cervical cancer. More specifically, BCAR4 expression was evaluated in cervical cancer tissues and cell lines by qRT-PCR. Moreover, the prognostic factors were assessed by Kaplan-Meier analysis and Cox proportional hazards models. Additionally, functional assays were conducted and the potential mechanism was explored.

RESULTS

Our study showed that BCAR4 expression was significantly up-regulated in cervical cancer tissue and cell lines. Moreover, patients with high BCAR4 expression showed worse survival outcomes and overexpression of BCAR4 might be an independent prognostic factor in cervical cancer. Furthermore, overexpression of BCAR4 remarkably promoted the proliferation, motility of cervical cancer cells and silencing BCAR4 significantly suppressed the proliferation, migration and invasion of cervical cancer cells. Additionally, overexpression of BCAR4 promoted epithelial-mesenchymal transition (EMT) process and silencing BCAR4 suppressed EMT process in cervical cancer cells.

CONCLUSIONS

The results indicated that BCAR4 might play a crucial role in cervical cancer progression and act as an underlying biomarker for the diagnosis and prognosis of cervical cancer.

lncRNA BCAR4 Increases Viability, Invasion, and Migration of Non-Small Cell Lung Cancer Cells by Targeting Glioma-Associated Oncogene 2 (GLI2)

This study aimed to explore the effects of lncRNA BCAR4 on the viability and aggressiveness of non-small cell lung cancer (NSCLC) cells. qRT-PCR was used to determine the expression of BCAR4 and GLI2 downstream genes in NSCLC tissues and cell lines. Chromatin isolation by RNA purification (CHIRP) and Western blot were employed to measure the expression of the GLI2 downstream proteins. Ki-67 expression in nude mice tumors was tested by immunohistochemistry. MTT assay, wound healing assay, and Transwell assay were used to assess NSCLC cell viability and aggressiveness, respectively. Tumor xenograft was conducted to determine the effects of BCAR4 and GLI2 on NSCLC tumorigenesis in vivo. The expression of BCAR4 in NSCLC tissues and cells was significantly higher than the normal level. The overexpression of BCAR4 promoted NSCLC cell viability, migration, and invasion. The suppression of BCAR4 and GLI2 showed the opposite effects. The overexpression of BCAR4 led to an increase in the expression of GLI2 downstream proteins, while the suppression of BCAR4 and GLI2 reduced their expression. In a tumor xenograft assay, the tumors in mice of the BCAR4 group showed the biggest volume, while those in mice of the si-GLI2 group showed the smallest volume. Ki-67 showed much higher levels in the BCAR4 overexpression group but much lower levels in the si-GLI2 group. In summary, the cooperative mechanism of lncRNA BCAR4 and GLI2 might provide a new opportunity for treating NSCLC.

LncRNA BCAR4 promotes colon cancer progression via activating Wnt/β-catenin signaling

BCAR4 (Breast Cancer Anti-Estrogen Resistance 4) is a long noncoding RNA that was identified as an oncogene in breast cancer. In our research, we found that the expression level of BCAR4 was upregulated in colon cancer tissues compared to paired normal tissues. What's more, higher BCAR4 expression was correlated with lower survival rate in patients with colon cancer. Mechanistically, we showed that BCAR4 activated Wnt/β-catenin signaling in colon cancer by protecting β-catenin from degradation. We also showed that BCAR4 overexpression promoted cell proliferation and migration in colon cancer. However, silencing BCAR4 inhibited cell growth and promoted apoptosis. Besides, BCAR4 knockdown decreased tumor growth in vivo. These findings indicate that BCAR4 facilitated colon cancer progression by enhancing cell proliferation and inhibiting apoptosis via BCAR4/β-catenin axis. BCAR4 may be a useful new target for treatment of patients with colon cancer.