Long non‑coding RNA FOXD2‑AS1/miR‑150‑5p/PFN2 axis regulates breast cancer malignancy and tumorigenesis

Urinary extracellular vesicles prevent di-(2-ethylhexyl) phthalate-induced hypospadias by facilitating epithelial-mesenchymal transition via PFN2 delivery

BACKGROUND

Urinary extracellular vesicles (EVs) have gained increasing interest in recent years as a potential source of noninvasive biomarkers of diseases related to urinary organs, but knowledge of the mechanism is still limited. The current study sought to clarify the mechanism of urinary EVs behind di-(2-ethylhexyl) phthalate (DEHP)-induced hypospadias via PFN2 delivery.

METHOD

PFN2 expression in hypospadias was predicted by bioinformatics analysis. Following the induction of a hypospadias rat model using DEHP, rats were injected with EVs and/or underwent alteration of PFN2 and TGF-β1 to assess their effects in vivo. The extracted rat urothelial cells (UECs) were co-cultured with EVs extracted from urine for in vitro experiments.

RESULT

Microarray analysis predicted poor PFN2 expression in hypospadias. Upregulated PFN2 was found in urinary EVs, and restrained epithelial-mesenchymal transition (EMT) was observed in DEHP-exposed rats. Urinary EVs or PFN2 overexpression increased SMAD2, SMAD3, and TGF-β1 protein expression and SMAD2 and SMAD3 phosphorylation in UECs and DEHP-exposed rats. UEC migration, invasion, and EMT were augmented by EV co-culture or upregulation of PFN2. Of note, the silencing of TGF-β1 counterweighed the effect of PFN2. Besides, EV co-culture or overexpression of PFN2 or TGF-β1 elevated the body weight, anal-genital distance (AGD), anal-genital index (AGI), and EMT of DEHP-exposed rats.

CONCLUSION

In summary, urinary EVs activated the SMAD/TGF-β1 pathway to induce EMT via PFN2 delivery, thus protecting against DEHP-induced hypospadias. (1) EMT in epithelial cells inhibits DEHP-induced hypospadias. (2) Urine-derived EVs deliver PFN2 to promote EMT in epithelial cells. (3) PFN2 can activate the SMAD/TGF-β1 signaling axis. (4) Urine-derived EVs can transmit PFN2 to activate the SMAD/TGF-β1 signaling axis, thus promoting EMT and inhibiting the occurrence of hypospadias.

Coding roles of long non-coding RNAs in breast cancer: Emerging molecular diagnostic biomarkers and potential therapeutic targets with special reference to chemotherapy resistance

Dysregulation of epigenetic mechanisms have been depicted in several pathological consequence such as cancer. Different modes of epigenetic regulation (DNA methylation (hypomethylation or hypermethylation of promotor), histone modifications, abnormal expression of microRNAs (miRNAs), long non-coding RNAs, and small nucleolar RNAs), are discovered. Particularly, lncRNAs are known to exert pivot roles in different types of cancer including breast cancer. LncRNAs with oncogenic and tumour suppressive potential are reported. Differentially expressed lncRNAs contribute a remarkable role in the development of primary and acquired resistance for radiotherapy, endocrine therapy, immunotherapy, and targeted therapy. A wide range of molecular subtype specific lncRNAs have been assessed in breast cancer research. A number of studies have also shown that lncRNAs may be clinically used as non-invasive diagnostic biomarkers for early detection of breast cancer. Such molecular biomarkers have also been found in cancer stem cells of breast tumours. The objectives of the present review are to summarize the important roles of oncogenic and tumour suppressive lncRNAs for the early diagnosis of breast cancer, metastatic potential, and chemotherapy resistance across the molecular subtypes.

Knockdown of circ-ADAM9 inhibits malignant phenotype and enhances radiosensitivity in breast cancer cells via acting as a sponge for miR-383-5p

BACKGROUND

Circular RNA (circRNA) has been proven to play a critical role in breast cancer progression. Therefore, this study was designed to clarify the role and underlying molecular mechanisms of circ-disintegrin and metalloproteinase 9 (circ-ADAM9) in breast cancer.

METHODS

A quantitative real-time polymerase chain reaction (RT-qPCR) was conducted to assess the expression levels of circ-ADAM9, microRNA-383-5p (miR-383-5p), and profilin 2 (PFN2). Cellular growth curves of breast cancer cells were determined by colony-forming assay. Cell viability and apoptosis were measured by MTT and flow cytometry, respectively. The protein expression level was analyzed by western blot. Cell migration and invasion were evaluated by wound healing and Transwell assays. A xenograft experiment was established to clarify the functional role of circ-ADAM9 inhibition in vivo. The interactions among circ-ADAM9, miR-383-5p, and PFN2 were analyzed by dual-luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull-down assays.

RESULTS

We found that circ-ADAM9 was upregulated in breast cancer tissues and cells compared to controls. Inhibition of circ-ADAM9 expression impaired proliferation, migration, and invasion, but increased radiosensitivity and apoptosis in breast cancer cells; besides, radiotherapy combined with circ-ADAM9 inhibition showed significant inhibitory effects on tumor growth. The functional effects of circ-ADAM9 were related to miR-383-5p, a target of circ-ADAM9. Overexpression of miR-383-5p-mediated malignant behaviors and radiosensitivity of breast cancer cells were dependent on PFN2.

CONCLUSION

Circ-ADAM9 was found to participate in breast cancer progression through targeting the miR-383-5p/PFN2 axis.

Evaluation of lncRNA FOXD2-AS1 Expression as a Diagnostic Biomarker in Colorectal Cancer

Background

Colorectal cancer (CRC) is still considered one of the prevalent cancers worldwide. Investigation of potential biomarkers for early detection of CRC is essential for the effective management of patients using therapeutic strategies. Considering that, this study was aimed to examine the changes in lncRNA FOXD2-AS1 expression through colorectal tumorigenesis.

Methods

Fifty CRC tumor tissues and fifty adjacent normal tissue samples were prepared and involved in the current study. Total RNA was extracted from the samples and then reverse transcribed to complementary DNA. Next, the expression levels of lncRNA FOXD2-AS1 were evaluated using real-time PCR in CRC samples compared to normal ones. Also, receiver operating characteristic curve analysis was used to evaluate the diagnostic value of FOXD2-AS1 for CRC.

Results

The obtained results showed that the expression level of FOXD2-AS1 gene was significantly (p<0.0001) up-regulated in tumor tissues compared to normal marginal tissues. Also, a significant correlation was observed between higher the expression of FOXD2-AS1and the differentiation of tumor cells. Furthermore, ROC curve analysis estimated an AUC value of 0.59 for FOXD2-AS1, suggesting its potential as a diagnostic target.

Conclusion

Taken together, the current study implied that tissue-specific upregulation of lncRNA FOXD2-AS1 might be appropriate diagnostic biomarkers for CRC. Nonetheless, more studies are needed to validate these results and further illustrate FOXD2-AS1 function through colorectal tumorigenesis.

FOXD2-AS1 acts an oncogene in esophageal squamous cell carcinoma through sponging miR-204-3p

PURPOSE

A growing number of evidences has revealed that long non-coding RNAs (lncRNAs) have vital effect in the pathogenesis of esophageal squamous cell carcinoma (ESCC). In our work, we found that lncRNA FOXD2 adjacent opposite strand RNA 1 (FOXD2-AS1) was significantly increased in clinical ESCC samples and cell lines.

METHODS

The biological effect of FOXD2-AS1 on EC109 and KYSE150 cells showed that the low expression of FOXD2-AS1 inhibited the proliferation through CCK8 and colony formation assays, invasion by transwell chamber test, migration abilities by wound healing assay, and enhance apoptosis rates by flow cytometry assay.

RESULTS

Through bioinformatics analysis and luciferase reporter assays, microRNA (miR)-204-3p was proved to be a target of FOXD2-AS1. We further confirmed that FOXD2-AS1 was the upstream inhibitor of miR-204-3p and the down-regulation of miR-204-3p reversed the repressive effects of low expression of FOXD2-AS1 on ESCC progression. In addition, inhibition of FOXD2-AS1 effectively suppressed the tumor growth.

CONCLUSIONS

In general, our results suggested that FOXD2-AS1 may be of vital therapeutic importance for the treatment of ESCC patients.

MicroRNAs miR-142-5p, miR-150-5p, miR-320a-3p, and miR-4433b-5p in Serum and Tissue: Potential Biomarkers in Sporadic Breast Cancer

Breast cancer (BC) is a heterogeneous disease, and establishing biomarkers is essential to patient management. We previously described that extracellular vesicle–derived miRNAs (EV-miRNAs) miR-142-5p, miR-150-5p, miR-320a, and miR-4433b-5p in serum discriminated BC from control samples, either alone or combined in a panel. Using these previously described markers, we intend to evaluate whether the same markers identified in EVs are also potential biomarkers in tissue and serum. Expression analysis using RT-qPCR was performed using serum of 67 breast cancer patients (BC-S), 19 serum controls (CT), 83 fresh tumor tissues (BC-T), and 29 adjacent nontumor tissue samples (NT). In addition, analysis from The Cancer Genome Atlas (TCGA) data (832 BC-T and 136 NT) was performed. In all comparisons, we found concordant high expression levels of miR-320a and miR-4433b-5p in BC-S compared to CT in both EVs and cell-free miRNAs (cf-miRNAs). Although miR-150-5p and miR-142-5p were not found to be differentially expressed in serum, panels including these miRNAs improved sensitivity and specificity, supporting our previous findings in EVs. Fresh tissue and data from the TCGA database had, in most comparisons, an opposite behavior when compared to serum and EVs: lower levels of all miRNAs in BC-T than those in NT samples. TCGA analyses revealed reduced expression levels of miR-150-5p and miR-320a-3p in BC-T than those in NT samples and the overexpression of miR-142-5p in BC-T, unlike our RT-qPCR results from tissue in the Brazilian cohort. The fresh tissue analysis showed that all miRNAs individually could discriminate between BC-T and NT in the Brazilian cohort, with high sensitivity and sensibility. Furthermore, combining panels showed higher AUC values and improved sensitivity and specificity. In addition, lower levels of miR-320a-3p in serum were associated with poor overall survival in BC Brazilian patients. In summary, we observed that miR-320a and miR-4433b-5p distinguished BC from controls with high specificity and sensibility, regardless of the sample source. In addition, lower levels of miR-150-5p and higher levels of miR-142-5p were statistically significant biomarkers in tissue, according to TCGA. When combined in panels, all combinations could distinguish BC patients from controls. These results highlight a potential application of these miRNAs as BC biomarkers.

MiR-150-5p Overexpression in Triple-Negative Breast Cancer Contributes to the In Vitro Aggressiveness of This Breast Cancer Subtype

Simple Summary

Triple-negative breast cancer (TNBC) is a clinically aggressive type of breast cancer. MicroRNAs (miRNAs) are small molecules that regulate the expression of genes involved in tumor cell signaling. The miR-150-5p is frequently deregulated in cancer, with expression and mode of action varying according to the cancer type. In this study, we investigated the expression levels of miR-150-5p in TNBC, its association with clinical and pathological features of patients, and its role in modulating TNBC cell proliferation, migration, and drug resistance. Our results suggest that miR-150-5p is highly expressed in TNBC and that miR-150-5p expression levels are associated with tumor grade, patient survival, and ethnicity. Our findings also indicate that miR-150-5p contributes to the aggressive phenotypes of TNBC cells in vitro.

Abstract

MiR-150-5p is frequently deregulated in cancer, with expression and mode of action varying according to the tumor type. Here, we investigated the expression levels and role of miR-150-5p in the aggressive breast cancer subtype triple-negative breast cancer (TNBC). MiR-150-5p expression levels were analyzed in tissue samples from 113 patients with invasive breast cancer (56 TNBC and 57 non-TNBC) and 41 adjacent non-tumor tissues (ANT). Overexpression of miR-150-5p was observed in tumor tissues compared with ANT tissues and in TNBC compared with non-TNBC tissues. MiR-150-5p expression levels were significantly associated with high tumor grades and the Caucasian ethnicity. Interestingly, high miR-150-5p levels were associated with prolonged overall survival. Manipulation of miR-150-5p expression in TNBC cells modulated cell proliferation, clonogenicity, migration, and drug resistance. Manipulation of miR-150-5p expression also resulted in altered expression of its mRNA targets, including epithelial-to-mesenchymal transition markers, MYB, and members of the SRC pathway. These findings suggest that miR-150-5p is overexpressed in TNBC and contributes to the aggressiveness of TNBC cells in vitro.

OCT1-target neural gene PFN2 promotes tumor growth in androgen receptor-negative prostate cancer

Androgen and androgen receptor (AR) targeted therapies are the main treatment for most prostate cancer (PC) patients. Although AR signaling inhibitors are effective, tumors can evade this treatment by transforming to an AR-negative PC via lineage plasticity. OCT1 is a transcription factor interacting with the AR to enhance signaling pathways involved in PC progression, but its role in the emergence of the AR-negative PC is unknown. We performed chromatin immunoprecipitation sequencing (ChIP-seq) in patient-derived castration-resistant AR-negative PC cells to identify genes that are regulated by OCT1. Interestingly, a group of genes associated with neural precursor cell proliferation was significantly enriched. Then, we focused on neural genes STNB1 and PFN2 as OCT1-targets among them. Immunohistochemistry revealed that both STNB1 and PFN2 are highly expressed in human AR-negative PC tissues. Knockdown of SNTB1 and PFN2 by siRNAs significantly inhibited migration of AR-negative PC cells. Notably, knockdown of PFN2 showed a marked inhibitory effect on tumor growth in vivo. Thus, we identified OCT1-target genes in AR-negative PC using a patient-derived model, clinicopathologial analysis and an animal model.

Impact of miR-1/miR-133 Clustered miRNAs: PFN2 Facilitates Malignant Phenotypes in Head and Neck Squamous Cell Carcinoma

Based on our original RNA sequence-based microRNA (miRNA) signatures of head and neck squamous cell carcinoma (HNSCC), it was revealed that the expression levels of miR-1-3p, miR-206, miR-133a-3p, and miR-133b were significantly suppressed in cancer specimens. Seed sequences of miR-1-3p/miR-206 and miR-133a-3p/miR-133b are identical. Interestingly, miR-1-3p/miR-133a-3p and miR-206/miR-133b are clustered in the human genome. We hypothesized that the genes coordinately controlled by these miRNAs are closely involved in the malignant transformation of HNSCC. Our in silico analysis identified a total of 28 genes that had putative miR-1-3p/miR-133a-3p and miR-206/miR-133b binding sites. Moreover, their expression levels were upregulated in HNSCC tissues. Multivariate Cox regression analyses showed that expression of PFN2 and PSEN1 were independent prognostic factors for patients with HNSCC (p < 0.05). Notably, four miRNAs (i.e., miR-1-3p, miR-206, miR-133a-3p, and miR-133b) directly bound the 3′untranslated region of PFN2 and controlled expression of the gene in HNSCC cells. Overexpression of PFN2 was confirmed in clinical specimens, and its aberrant expression facilitated cancer cell migration and invasion abilities. Our miRNA-based strategy continues to uncover novel genes closely involved in the oncogenesis of HNSCC.

Circ_0008500 Knockdown Improves Radiosensitivity and Inhibits Tumorigenesis in Breast Cancer Through the miR-758-3p/PFN2 Axis

Breast cancer is one of the most common malignancies worldwide. Circular RNAs (CircRNAs) were revealed to be implicated in the development of breast cancer. In this research, we aimed to investigate the role and underlying mechanism of circ_0008500 in the development and radiosensitivity of breast cancer. Using real-time quantitative PCR (RT-qPCR) and western blot, we found that hsa_circ_0008500 (circ_0008500) and profilin 2 (PFN2) were increased, while microRNA-758-3p (miR-758-3p) was decreased in breast cancer tissues and cells. Cell viability, the number of colonies, proliferation and apoptosis were detected using CCK-8, colony formation, EdU assays and flow cytometry, respectively. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were devoted to test the interaction between miR-758-3p and circ_0008500 or PFN2. The results showed that circ_0008500 knockdown inhibited cell growth, and facilitated cell apoptosis and radiosensitivity in breast cancer cells in vitro. Moreover, circ_0008500 regulated PFN2 expression by sponging miR-758-3p. Functionally, circ_0008500 knockdown regulated cell behaviors and radiosensitivity by targeting miR-758-3p to downregulate PFN2 expression in vitro. Additionally, in vivo tumor formation assay and immunohistochemistry (IHC) assay demonstrated that circ_0008500 knockdown enhanced the radiosensitivity and repressed tumor growth in vivo. In conclusion, circ_0008500 inhibition promoted the radiosensitivity and restrained the development of breast cancer by downregulating PFN2 expression via targeting miR-758-3p.

Long non-coding RNA PVT1 facilitates cell migration and invasion by regulating miR-148a-3p and ROCK1 in breast cancer

PURPOSE

Breast cancer (BC) is one of the most common malignant tumors for women. The role and potential mechanisms of long non-coding RNA plasmacytoma variant translocation 1 (lncRNA PVT1) were explored in BC cell migration and invasion.

METHODS

PVT1, miR-148a-3p and Rho‑associated, coiled‑coil containing protein kinase 1 (ROCK1) mRNA expressions were detected using real-time fluorescent quantitative polymerase chain reaction (qRT-PCR). The ROCK1 protein expression was detected by Western blotting. The relationship of PVT1, miR-148a-3p and ROCK1 was analyzed by Dual Luciferase activity, RNA immunoprecipitation (RIP) and Spearman correlation analysis. Cell invasion and migration were detected by Transwell assay.

RESULTS

Upregulation of PVT1 and ROCK1, and downregulation of miR-148a-3p were observed in BC tissues and cell lines. According to the analysis of Dual Luciferase activity, RIP and Spearman correlation analysis, miR-148a-3p directly binds to PVT1, and ROCK1 is a target of miR-148a-3p. In addition, PVT1 regulated the cells migration and invasion by regulating miR-148a-3p and ROCK1 expression.

CONCLUSION

These data demonstrated that PVT1 was upregulated and facilitated to the cell migration and invasion of BC by the regulation of miR-148a-3p and ROCK1, indicating that PVT1 may be a potential biomarker of BC diagnosis and treatment.

Knockdown of lncRNA FOXD2-AS1 Inhibits Proliferation, Migration, and Drug Resistance of Breast Cancer Cells

OBJECTIVE

In order to investigate the effect of lncRNA FOXD2-AS1 on breast cancer cells proliferation, migration, and drug resistance as well as its molecular mechanism.

METHODS

Real-time PCR was used to detect the expression of breast cancer tissues and cells from patients admitted to our hospital and the expression of lncRNA FOXD2-AS1 in MCF-7/ADR in adriamycin- (ADR-) resistant breast cancer cells. After interfering with or overexpressing lncRNA FOXD2-AS1 in MCF-7/ADR cells, cell proliferation, apoptosis, invasion, and migration were detected using CCK-8, flow cytometry, Transwell assay, and scratch test, respectively. The protein levels of PI3K, p-PI3K, AKT, and p-AKT in the PI3K/AKT signaling pathway were detected by Western blot.

RESULTS

lncRNA FOXD2-AS1 was upregulated in breast cancer tissues and cells and increased cell drug resistance to ADR. Downregulation of lncRNA FOXD2-AS1 inhibited invasion and migration of MCF-7/ADR cells, promoted apoptosis, increased chemosensitivity of MCF-7/ADR cells, and inhibited the activity of PI3K/AKT signaling pathway in MCF-7/ADR cells.

CONCLUSIONS

lncRNA FOXD2-AS1 can promote the proliferation, invasion, migration, and drug resistance of breast cancer cells, inhibit apoptosis, and accelerate the development of breast cancer by positively regulating the PI3K/AKT signaling pathway.

Research updates on the clinical implication of long noncoding RNA in digestive system cancers and chemoresistance

Long noncoding RNAs (lncRNAs) are implicated in various biological processes, such as cell proliferation, differentiation, apoptosis, migration, and invasion. They are also key players in various biological pathways. LncRNA was considered as 'translational noise' before 1980s. It has been reported that lncRNAs are aberrantly expressed in different cancers, either as oncogene or tumor suppressor gene. Therefore, more and more lncRNAs are recognized as potential diagnostic biomarkers and/or therapeutic targets. As competitive endogenous RNA, lncRNAs can interact with microRNA to alter the expression of target genes, which may have extensive clinical implications in cancers, including diagnosis, treatment, prognosis, and chemoresistance. This review comprehensively summarizes the functions and clinical relevance of lncRNAs in digestive system cancers, especially as a potential tool to overcome chemoresistance.

The role of FOXD2-AS1 in cancer: a comprehensive study based on data mining and published articles

Background and aims: Long non-coding RNA (lncRNA) FOXD2 adjacent opposite strand RNA 1 (FOXD2-AS1) is aberrantly expressed in various cancers and associated with cancer progression. A comprehensive meta-analysis was performed based on published literature and data in the Gene Expression Omnibus database, and then the Cancer Genome Atlas (TCGA) dataset was used to assess the clinicopathological and prognostic value of FOXD2-AS1 in cancer patients.

Methods: Gene Expression Omnibus databases of microarray data and published articles were used for meta-analysis, and TCGA dataset was also explored using the GEPIA analysis program. Hazard ratios (HRs) and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the role of FOXD2-AS1 in cancers.

Results: This meta-analysis included 21 studies with 2391 patients and 25 GEO datasets with 3311 patients. The pooled HRs suggested that highly expressed FOXD2-AS1 expression was correlated with poor overall survival (OS) and disease-free survival (DFS). Similar results were obtained by analysis of TCGA data for 9502 patients. The pooled results also indicated that FOXD2-AS1 expression was associated with bigger tumor size and advanced TNM stage, but was not related to age, gender, differentiation and lymph node metastasis.

Conclusion: The present study demonstrated that FOXD2-AS1 is closely related to tumor size and TNM stage. Additionally, increased FOXD2-AS1 was a risk factor of OS and DFS in cancer patients, suggesting FOXD2-AS1 may be a potential biomarker in human cancers.

The Unique Biology behind the Early Onset of Breast Cancer

Breast cancer commonly affects women of older age; however, in developing countries, up to 20% of breast cancer cases present in young women (younger than 40 years as defined by oncology literature). Breast cancer in young women is often defined to be aggressive in nature, usually of high histological grade at the time of diagnosis and negative for endocrine receptors with poor overall survival rate. Several researchers have attributed this aggressive nature to a hidden unique biology. However, findings in this aspect remain controversial. Thus, in this article, we aimed to review published work addressing somatic mutations, chromosome copy number variants, single nucleotide polymorphisms, differential gene expression, microRNAs and gene methylation profile of early-onset breast cancer, as well as its altered pathways resulting from those aberrations. Distinct biology behind early-onset of breast cancer was clear among estrogen receptor-positive and sporadic cases. However, further research is needed to determine and validate specific novel markers, which may help in customizing therapy for this group of patients.

Profilin 2 (PFN2) promotes the proliferation, migration, invasion and epithelial-to-mesenchymal transition of triple negative breast cancer cells

BACKGROUND

Triple negative breast cancer (TNBC) is the most aggressive subtype with the worst prognosis. The role of profilin 2 (PFN2) in TNBC is very controversial. The current study is to explore the role of PFN2 in TNBC.

METHODS

PFN2 expression in TNBC and normal breast tissues were evaluated by immunohistochemical analysis. The association between PFN2 expression and prognosis in TNBC patients was analyzed from the TCGA database. A cell counting kit-8 (CCK8) assay was employed to investigate the effects of PFN2 in TNBC cell proliferations. The migration and invasion capability of TNBC cells was evaluated by transwell assays. Western blot was performed to assess the related protein expression of TGF-β/Smad signaling and epithelial to mesenchymal transition. Finally, TNBC xenografts were established to determine the tumorigenicity in vivo using female Nod/Scid mice.

RESULTS

PFN2 is upregulated in TNBC and the higher expression was associated with worse survival. CCK8 assays and Transwell assays demonstrated that PFN2 promoted the proliferation, migration and invasion of TNBC cells. Smad2 and Smad3 were upregulated in PFN2 overexpressing TNBC cells, which further induced the process of epithelial‑to‑mesenchymal transition. Similarly, the overexpressing PFN2 TNBC cells exhibited stronger tumorigenicity in vivo.

CONCLUSIONS

Higher PFN2 expression is associated with a worse 10-year overall survival and relapse-free survival in breast cancer patients, as well as worse 10-year relapse-free survival in TNBC patients. PFN2 promotes the proliferation, migration and invasion of TNBC cells by regulating epithelial-to-mesenchymal transition.

Long non‑coding RNA FOXD2‑AS1 regulates the tumorigenesis and progression of breast cancer via the S100 calcium binding protein A1/Hippo signaling pathway

Breast cancer is one of the most prevalent cancer types and is accompanied by a high incidence and mortality rate, severely threatening women's health globally. Long non‑coding RNA forkhead box D2 adjacent apposite strand RNA 1 (lncRNA FOXD2‑AS1) has been identified to function as an oncogene in human cancers; however, it has rarely been investigated in breast cancer. The aim of the present study was to investigate the role of FOXD2‑AS1 in breast cancer, and to clarify the underlying mechanisms. The expression of FOXD2‑AS1 in breast cancer cell lines was first quantified by reverse transcription‑quantitative PCR, and the biological function of FOXD2‑AS1 was then determined. Cellular proliferative ability was determined by Cell Counting kit‑8 assay, and wound healing and Transwell assays were conducted to assess the cell migratory and invasive ability. Corresponding protein expression levels were determined by western blot analysis. In addition, experimental animal models were established by the subcutaneous injection of MDA‑MB‑468 cells into the right axillary lymph nodes of BALB/c nude mice, and the effects of FOXD2‑AS1 on tumor growth were observed. The results indicated that FOXD2‑AS1 expression was upregulated in breast cancer cell lines, and that FOXD2‑AS1 downregulation significantly inhibited the proliferation, migration and invasiveness of MCF‑7 and MDA‑MB‑468 cells. S100 calcium binding protein A1 (S100A1) was also upregulated in breast cancer cell lines and was positively regulated by FOXD2‑AS1. Furthermore, the inhibition of S100A1 and the overexpression of the serine/threonine‑protein kinase, large tumor suppressor homolog 1 (LATS1), inhibited the FOXD2‑AS1‑induced cellular proliferation, migration and invasiveness in breast cancer. Experimental mouse models revealed that FOXD2‑AS1 downregulation significantly inhibited tumor growth, and that the levels of phosphorylated (p‑)YAP and p‑LATS1 were upregulated by FOXD2‑AS1 knockdown, indicating that the inhibition of FOXD2‑AS1 activated Hippo/yes‑associated protein signaling. On the whole, the findings of the present study suggest that the FOXD2‑AS1/S100A1/Hippo axis is involved in the tumorigenesis and progression of breast cancer. In the future, these may contribution to the identification of more effective breast cancer treatments.

LncRNA FAM83H-AS1 promotes triple-negative breast cancer progression by regulating the miR-136-5p/metadherin axis

In this study, we evaluated the function and regulation of the long non-coding RNA (lncRNA) FAM83H-AS1 in triple-negative breast cancer (TNBC). Our data show that the FAM83H-AS1 levels are increased in human TNBC cells and tissues. Proliferation, migration, and invasion of TNBC cells are decreased by FAM83H-AS1 suppression, but increased by FAM83H-AS1 overexpression. Bioinformatics analysis revealed that miR-136-5p is a potential target of FAM83H-AS1. MiR-136-5p expression is decreased in TNBC tissues, and its overexpression suppresses TNBC cell proliferation, migration, and invasion. MiR-136-5p suppression reverses the FAM83H-AS1 silencing-mediated inhibition of TNBC cell proliferation, migration, and invasion, suggesting that FAM83H-AS1 exerts its oncogenic effect by inhibiting miR-136-5p. Our data identify metadherin (MTDH) as the target gene of miR-136-5p, and demonstrate that the MTDH expression is increased in human TNBC tissues, which induces proliferation, migration, and invasion of TNBC cells. Importantly, our in vivo data show that FAM83H-AS1 also promotes tumor growth in TNBC mouse xenografts. Together, our results demonstrate that FAM83H-AS1 functions as an oncogenic lncRNA that regulates miR-136-5p and MTDH expression during TNBC progression, and suggest that targeting the FAM83H-AS1/miR-136-5p/MTDH axis may serve as a novel therapeutic target in TNBC.