PBX3-activated DLG1-AS1 can promote the proliferation, invasion, and migration of TNBC cells by sponging miR-16-5p

Abstract

DLG1-AS1 and PBX3 have been identified as acting as an oncogene in cervical cancer. However, they have not been well explored in triple-negative breast cancer (TNBC). As TNBC is one of the malignancies causing increasing death throughout the world, this study aimed to probe into the regulatory relationship between DLG1-AS1 and PBX3 in TNBC cells. In this study, real-time quantitative PCR (qRT-PCR) and western blot experiments were conducted to investigate the RNA and protein levels of genes of interest in TNBC cells. Functional experiments were implemented, such as 5-ethynyl-2′-deoxyuridine (EdU), transwell, and wound healing assays, to assess the changes in TNBC cell phenotype. Chromatin immunoprecipitation, luciferase reporter, RNA binding protein immunoprecipitation, and RNA pull-down assays were conducted to investigate the binding relationships among subject genes. The results show that DLG1-AS1 and PBX3 displayed high expression in TNBC cells, and PBX3 worked as the transcriptional activator of DLG1-AS1. Also, DLG1-AS1 served as an oncogene in TNBC cells and as a sponge for miR-16-5p to up-regulate JARID2. Meanwhile, JARID2 and PBX3 exerted oncogenic effects on TNBC cell growth. In conclusion, PBX3-activated DLG1-AS1 can promote the proliferation, invasion, and migration of TNBC cells by sponging miR-16-5p and elevating JARID2 expression. DLG1-AS1 and PBX3 have been identified as acting as an oncogene in cervical cancer. However, they have not been well explored in triple-negative breast cancer (TNBC). As TNBC is one of the malignancies causing increasing death throughout the world, this study aimed to probe into the regulatory relationship between DLG1-AS1 and PBX3 in TNBC cells. In this study, real-time quantitative PCR (qRT-PCR) and western blot experiments were conducted to investigate the RNA and protein levels of genes of interest in TNBC cells. Functional experiments were implemented, such as 5-ethynyl-2′-deoxyuridine (EdU), transwell, and wound healing assays, to assess the changes in TNBC cell phenotype. Chromatin immunoprecipitation, luciferase reporter, RNA binding protein immunoprecipitation, and RNA pull-down assays were conducted to investigate the binding relationships among subject genes. The results show that DLG1-AS1 and PBX3 displayed high expression in TNBC cells, and PBX3 worked as the transcriptional activator of DLG1-AS1. Also, DLG1-AS1 served as an oncogene in TNBC cells and as a sponge for miR-16-5p to up-regulate JARID2. Meanwhile, JARID2 and PBX3 exerted oncogenic effects on TNBC cell growth. In conclusion, PBX3-activated DLG1-AS1 can promote the proliferation, invasion, and migration of TNBC cells by sponging miR-16-5p and elevating JARID2 expression. IntroductionAs one of the most malignant cancers in women, breast cancer has caused much death worldwide.1Foulkes W.D. Smith I.E. Reis-Filho J.S. Triple-negative breast cancer.New Engl. J. Med. 2010; 363: 1938-1948Crossref PubMed Scopus (2619) Google Scholar, 2Anastasiadi Z. Lianos G.D. Ignatiadou E. Harissis H.V. Mitsis M. Breast cancer in young women: an overview.Updates Surg. 2017; 69: 313-317Crossref PubMed Scopus (299) Google Scholar, 3Merino Bonilla J.A. Torres Tabanera M. Ros Mendoza L.H. Breast cancer in the 21st century: from early detection to new therapies.Radiologia. 2017; 59: 368-379Crossref PubMed Scopus (77) Google Scholar Triple-negative breast cancer (TNBC) cases account for nearly 13%–18% of breast cancer cases and have a worse prognosis than other subtypes of breast cancer.4Siegel R.L. Miller K.D. Jemal A. Cancer statistics.CA Cancer J. Clin. 2015; 65: 5-29Crossref PubMed Scopus (11400) Google Scholar Recently, TNBC has been intensely investigated, because it may lead to crucial clinical problems. TNBC has an aggressive nature. Patients with TNBC are relatively young, but they are usually diagnosed at the advanced stage, or even worse, they are more likely to have tumor metastasis, causing death.5Podo F. Buydens L.M. Degani H. Hilhorst R. Klipp E. Gribbestad I.S. Van Huffel S. van Laarhoven H.W. Luts J. Monleon D. et al.Triple-negative breast cancer: present challenges and new perspectives.Mol. Oncol. 2010; 4: 209-229Crossref PubMed Scopus (233) Google Scholar,6Carey L. Winer E. Viale G. Cameron D. Gianni L. Triple-negative breast cancer: disease entity or title of convenience?.Nat. Rev. Clin. Oncol. 2010; 7: 683-692Crossref PubMed Scopus (617) Google Scholar Therefore, we need to dig into the molecular mechanisms of TNBC and try to find a new and effective therapeutic target.RNAs with more than 200 nt and limited protein-coding capability are defined as long non-coding RNAs (lncRNAs).7St Laurent G. Wahlestedt C. Kapranov P. The Landscape of long noncoding RNA classification.Trends Genetics TIG. 2015; 31: 239-251Abstract Full Text Full Text PDF PubMed Scopus (718) Google Scholar lncRNAs have been studied and play an increasingly important role in biological functions of multiple cancer cells,8Geisler S. Coller J. RNA in unexpected places: long non-coding RNA functions in diverse cellular contexts.Nat. Rev. Mol. Cell Biol. 2013; 14: 699-712Crossref PubMed Scopus (1059) Google Scholar, 9Kondo Y. Shinjo K. Katsushima K. Long non-coding RNAs as an epigenetic regulator in human cancers.Cancer Sci. 2017; 108: 1927-1933Crossref PubMed Scopus (212) Google Scholar, 10Dey B.K. Mueller A.C. Dutta A. Long non-coding RNAs as emerging regulators of differentiation, development, and disease.Transcription. 2014; 5: e944014Crossref PubMed Scopus (261) Google Scholar including TNBC.11Wang L. Liu D. Wu X. Zeng Y. Li L. Hou Y. Li W. Liu Z. Long non-coding RNA (LncRNA) RMST in triple-negative breast cancer (TNBC): expression analysis and biological roles research.J. Cell. Physiol. 2018; 233: 6603-6612Crossref PubMed Scopus (57) Google Scholar,12Li P. Zhou B. Lv Y. Qian Q. LncRNA HEIH regulates cell proliferation and apoptosis through miR-4458/SOCS1 axis in triple-negative breast cancer.Hum. Cell. 2019; 32: 522-528Crossref PubMed Scopus (32) Google Scholar For instance, lncRNA GAS5 has been confirmed to be up-regulated in TNBC cells and to exert oncogenic influences on apoptosis of TNBC cells.13Li J. Li L. Yuan H. Huang X.W. Xiang T. Dai S. Up-regulated lncRNA GAS5 promotes chemosensitivity and apoptosis of triple-negative breast cancer cells.Cell Cycle. 2019; 18: 1965-1975Crossref PubMed Scopus (30) Google Scholar To date, lncRNAs have been studied in many important cancers and have been found to interact with many other cellular macromolecules.14Huarte M. The emerging role of lncRNAs in cancer.Nat. Med. 2015; 21: 1253-1261Crossref PubMed Scopus (1820) Google Scholar,15Evans J.R. Feng F.Y. Chinnaiyan A.M. The bright side of dark matter: lncRNAs in cancer.J. Clin. Invest. 2016; 126: 2775-2782Crossref PubMed Google Scholar lncRNA LUCAT1 has been identified as promoting tumorigenesis and metastasis of TNBC by sponging miR-5702.16Mou E. Wang H. LncRNA LUCAT1 facilitates tumorigenesis and metastasis of triple-negative breast cancer through modulating miR-5702.Biosci. Rep. 2019; 39 (BSR20190489)Crossref Scopus (25) Google Scholar In this study, we aimed to dig into the molecular functions of other lncRNAs in TNBC, which may provide us new insights into the study of cancer.Discs large MAGUK scaffold protein 1 antisense RNA 1 (DLG1-AS1) has been studied in a previous study, where it was found that it can act as an oncogene in cervical cancer (CC). More specifically, DLG1-AS1 can promote the proliferation of CC cells.17Rui X. Xu Y. Huang Y. Ji L. Jiang X. lncRNA DLG1-AS1 promotes cell proliferation by competitively binding with miR-107 and up-regulating ZHX1 expression in cervical cancer.Cell Physiol. Biochem. Int. J. Exp. Cell. Physiol. Biochem. Pharmacol. 2018; 49: 1792-1803Crossref PubMed Scopus (44) Google Scholar Moreover, DLG1-AS1 has been shown to facilitate TNBC cell proliferation by down-regulating miR-203.18Li S. LncRNA DLG1-AS1 promotes cancer cell proliferation in triple negative breast cancer by downregulating miR-203.J. Breast Cancer. 2020; 23: 343-354Crossref PubMed Scopus (5) Google Scholar Nevertheless, the role of DLG1-AS1 in TNBC cell migration and invasion had not been well explored. Therefore, this study focused on functions of DLG1-AS1 in TNBC cells. Further, Pre-B-cell leukemia homeobox 3 (PBX3) has been reported to have high expression in CC cells, which is associated with the poor overall survival of CC patients, and it promotes the growth of CC cells.19Li H. Sun G. Liu C. Wang J. Jing R. Wang J. Zhao X. Xu X. Yang Y. PBX3 is associated with proliferation and poor prognosis in patients with cervical cancer.OncoTargets Ther. 2017; 10: 5685-5694Crossref PubMed Scopus (19) Google Scholar PBX3 has also been revealed to be remarkably up-regulated in letrozole-resistant breast cancer (BC) cells and tissues and is linked to relatively unfavorable progression-free survival of BC patients.20Pang Z.Y. Wei Y.T. Shang M.Y. Li S. Li Y. Jin Q.X. Liao Z.X. Cui M.K. Liu X.Y. Zhang Q. Leptin-elicited PBX3 confers letrozole resistance in breast Cancer. PubMed Scopus Google Scholar In this study, we to the of DLG1-AS1 and PBX3 on TNBC cell growth. The of DLG1-AS1 was also in this can act as the transcriptional activator of we the expression of DLG1-AS1 and PBX3 in human breast cells and TNBC cells. The of and western blot assays that DLG1-AS1 and PBX3 were in TNBC cells, in and cells and Meanwhile, to the of we found that PBX3 act as a transcriptional activator of which that DLG1-AS1 and PBX3 may interact with other in TNBC cells. Therefore, we the or of or and western blot the results PBX3 be up-regulated or by or we to investigate the of or PBX3 on the expression of DLG1-AS1 in TNBC cells. The results that PBX3 the expression of and PBX3 the expression of DLG1-AS1 PBX3 has been identified as a that regulates expression in R. PBX3 in 2020; Scopus Google Scholar we PBX3 DLG1-AS1 as a transcriptional the and found that was a binding between PBX3 and DLG1-AS1. present the of PBX3 as well as the binding between DLG1-AS1 and PBX3 in and Chromatin was to the binding relationship of DLG1-AS1 and found that they to other the DLG1-AS1 be remarkably in Moreover, the luciferase was to the of the binding it was revealed that the binding exert as the luciferase of than was by PBX3 or we that DLG1-AS1 and PBX3 were in TNBC cells and PBX3 as the transcriptional activator of act as an oncogene and a sponge for miR-16-5p in TNBC this we studied the role that DLG1-AS1 in TNBC cells. we the of shown in we conducted assays to the DLG1-AS1 on TNBC cells. to the results of a 5-ethynyl-2′-deoxyuridine we find that the growth of and was with Also, we and wound healing assays to investigate the invasion and migration of TNBC cells. the results that DLG1-AS1 the invasion and migration of TNBC cells and the of DLG1-AS1 in cells was by in and As shown in and DLG1-AS1 was in the cell lncRNA has been shown to as a RNA to the axis in cancer Y. W. Li T. Liu Y. Wu W. Li Z. L. Zhao X. Zhang T. et promotes and as a through 2020; PubMed Scopus Google Scholar we on the with and likely binding with DLG1-AS1 were on the we found among miR-16-5p was in TNBC cells with cells is that miR-16-5p can act as a tumor L. Qian X. breast cancer by to Rep. 2019; 39 (BSR20190489)Crossref Scopus Google Scholar miR-16-5p was we present the binding between DLG1-AS1 and miR-16-5p confirmed the high of miR-16-5p For the binding relationship between DLG1-AS1 and we luciferase assays and RNA pull-down that the luciferase of was in BC cells with miR-16-5p which that miR-16-5p to DLG1-AS1 RNA pull-down assays the that DLG1-AS1 be in In conclusion, DLG1-AS1 as an oncogene in TNBC cells and as a sponge for as an oncogene in TNBC cells and as a sponge for The of DLG1-AS1 was by experiments were to the of DLG1-AS1 and on the proliferation of TNBC cells and assays were conducted to study the invasion of and cells by or The migration of and cells with or was by wound healing and The of DLG1-AS1 in and cells was by and assays were by expression in TNBC cells and through The binding of DLG1-AS1 and miR-16-5p is to The of miR-16-5p was by and The binding relationship of DLG1-AS1 and miR-16-5p was by luciferase assays and RNA pull-down assays The were and PBX3 can act as an oncogene in TNBC we a to present the we from the expression of in TNBC cells and was we found that among the JARID2 was the one to be in TNBC cells Also, the binding between miR-16-5p and JARID2 is we luciferase assays to binding and the results that they with other Further, we conducted and found that and JARID2 were in the that miR-16-5p with DLG1-AS1 and JARID2. The results of RNA pull-down that more JARID2 was in DLG1-AS1 DLG1-AS1 with JARID2 as a sponge for Meanwhile, and western blot were to investigate the of DLG1-AS1 or miR-16-5p on the RNA and protein levels of JARID2. found that the expression of JARID2 was we or miR-16-5p into TNBC cells of was by and western blot assays we JARID2 the biological of TNBC cells. conducted transwell, and wound healing assays, and the results that JARID2 the proliferation, invasion, and migration of TNBC cells Moreover, we the of PBX3 on the malignant of TNBC cells as shown in we found that PBX3 act as an oncogene in TNBC cells In conclusion, JARID2 and PBX3 act as an oncogene in TNBC cells and the expression of JARID2 be by DLG1-AS1 and as an oncogene in TNBC cells and expression is by DLG1-AS1 and was to the of miR-16-5p to The expression of in TNBC cells and was by to find the cells with The binding between miR-16-5p and JARID2 is to The binding relationship between miR-16-5p and JARID2 was by luciferase and western blot were to investigate the of DLG1-AS1 and miR-16-5p on the expression and protein of JARID2. The of JARID2 was by and western blot assays in and cells. The proliferation, invasion, and migration of and cells was to investigate the of JARID2 on TNBC cells by and wound healing The were axis the malignant of TNBC we conducted experiments to the biological of TNBC cells by DLG1-AS1 and JARID2. the of JARID2 and western blot assays we transwell, and wound healing assays to investigate the TNBC cell proliferation, invasion, and migration As the results proliferation, invasion, and migration of and caused by were by the between DLG1-AS1 and JARID2 the biological of TNBC cells In PBX3-activated DLG1-AS1 can promote the proliferation, invasion, and migration of TNBC cells by sponging miR-16-5p and up-regulating malignant of TNBC cells are through the The of JARID2 was by and western blot assays in and cells. and wound healing assays were in and to the of DLG1-AS1 and JARID2 on TNBC cell proliferation, invasion, and The were one of the most subtypes of TNBC has a poor prognosis and a death W.D. Smith I.E. Reis-Filho J.S. Triple-negative breast cancer.New Engl. J. Med. 2010; 363: 1938-1948Crossref PubMed Scopus (2619) Google we early triple-negative breast cancer (TNBC): from the to 2018; Full Text Full Text PDF PubMed Scopus Google S. M. A. L. TNBC for new and 2018; Scopus Google Scholar by has been for of TNBC S. and effects of in the of breast Cancer Med. 2018; 10: Google A. K. S. M. L. et of resistance in a of breast cancer.J. 2017; PubMed Scopus Google Scholar other subtypes of cancers have found effective TNBC more effective therapeutic we early triple-negative breast cancer (TNBC): from the to 2018; Full Text Full Text PDF PubMed Scopus Google molecular of human breast PubMed Scopus Google Scholar Recently, lncRNAs have been identified as to the and poor prognosis of including P. Zhou B. Lv Y. Qian Q. LncRNA HEIH regulates cell proliferation and apoptosis through miR-4458/SOCS1 axis in triple-negative breast cancer.Hum. Cell. 2019; 32: 522-528Crossref PubMed Scopus (32) Google Xiang Yang Zhang W. LncRNA and regulates cancer cell proliferation and chemosensitivity in triple-negative breast cancer by with Cell. Biochem. 2019; PubMed Scopus Google X. Liu Z. Z. LncRNA is in triple negative breast cancer and with poor 2019; Scopus (30) Google Scholar For instance, the lncRNA has been shown to proliferation and chemosensitivity of TNBC by with Xiang Yang Zhang W. LncRNA and regulates cancer cell proliferation and chemosensitivity in triple-negative breast cancer by with Cell. Biochem. 2019; PubMed Scopus Google Scholar To TNBC and the poor prognosis of we conducted this to the of molecular mechanisms in TNBC and provide for therapeutic of the of lncRNAs have increasing from and they have to mechanisms on diverse cancer A.M. Long noncoding RNAs in cancer Cell. 2016; Full Text Full Text PDF PubMed Scopus Google Scholar As one of the DLG1-AS1 has been to act as an oncogene in which promotes the proliferation of CC Y. Shinjo K. Katsushima K. Long non-coding RNAs as an epigenetic regulator in human cancers.Cancer Sci. 2017; 108: 1927-1933Crossref PubMed Scopus (212) Google Scholar However, the of DLG1-AS1 In the present study, assays, and wound healing experiments were to the of DLG1-AS1 and on the proliferation of TNBC cells and The results that DLG1-AS1 can as an oncogene to the proliferation, and invasion of TNBC has also been reported to be in CC cells, and it can overall survival of patients and promote the growth of CC B.K. Mueller A.C. Dutta A. Long non-coding RNAs as emerging regulators of differentiation, development, and disease.Transcription. 2014; 5: e944014Crossref PubMed Scopus (261) Google Scholar Moreover, PBX3 has been to play a promoting role in BC J. R. Q. Wang H. J. Cui S. Y. Long non-coding RNA HEIH promotes breast cancer negative of 2019; Google Scholar Also, in study, we conducted a of experiments and the of PBX3 on TNBC cell phenotype. on PBX3 was in TNBC cells. Meanwhile, it was revealed to as an oncogene in TNBC cells as Moreover, we studied PBX3 the role of transcriptional activator of DLG1-AS1. and luciferase assays that PBX3 is the transcriptional activator of a of has a of However, it can to to and which can B. Li J. and 2014; PubMed Scopus Google R. and a J. Biol. 2015; PubMed Scopus Google Scholar miR-16-5p can as a tumor L. Qian X. breast cancer by to Rep. 2019; 39 (BSR20190489)Crossref Scopus Google Scholar In study, we miR-16-5p can to DLG1-AS1 and JARID2 by luciferase reporter, and RNA pull-down we found that DLG1-AS1 the expression of miR-16-5p JARID2 expression. Further, JARID2 was confirmed to play an oncogene role to facilitate TNBC cell growth. the we that DLG1-AS1 miR-16-5p to the expression of JARID2. a was In conclusion, PBX3-activated DLG1-AS1 can promote the proliferation, invasion, and migration of TNBC cells by acting as a sponge for for the in experiments and clinical were not in this In the we to in experiments and the expression of genes in TNBC that the of the can provide for the between DLG1-AS1 and TNBC and the of an effective for and cell were from with the human cells as was with and The were in an with at quantitative from was for cellular RNA from and cells. RNA were into for with the of a expression was by an by with or as are in in the in a new Cell cells were into for with for in with the for For the and miR-16-5p and were from For RNAs DLG1-AS1 PBX3 and JARID2 as well as the negative were by for are in was conducted as the of the The was and with served as the negative were the of genes was by DLG1-AS1 or PBX3 binding was and into by with or or into and cells. and were for PCR to at the of and was to the The were by a The DLG1-AS1 or JARID2 or miR-16-5p binding was into the to and JARID2 miR-16-5p or were into the TNBC cells. luciferase was by a into and are displayed in was with in to the TNBC cells in were with for was for was for was of cells were by TNBC cells were and into the of with and in the cells were with and by at healing BC cells in were by the The cells were with was for cell was by The of the wound was and was in a to the of DLG1-AS1 in and cells. The DLG1-AS1 probe was by The cells were with DLG1-AS1 probe in and with was to cells were in cell and for The was as the The was in cell on and to the the RNAs were the or expression was by binding protein the BC cells were with cell were with and the RNAs in the were and by pull-down RNA was and with a RNA of and cells were with the miR-16-5p and The was by the of miR-16-5p to DLG1-AS1. were for 1 at to are in cells were in an for and for The protein were by and to in on were with for at The and and were from were by was for and analysis of were for between with the of assays were in and the results were as IntroductionAs one of the most malignant cancers in women, breast cancer has caused much death worldwide.1Foulkes W.D. Smith I.E. Reis-Filho J.S. Triple-negative breast cancer.New Engl. J. Med. 2010; 363: 1938-1948Crossref PubMed Scopus (2619) Google Scholar, 2Anastasiadi Z. Lianos G.D. Ignatiadou E. Harissis H.V. Mitsis M. Breast cancer in young women: an overview.Updates Surg. 2017; 69: 313-317Crossref PubMed Scopus (299) Google Scholar, 3Merino Bonilla J.A. Torres Tabanera M. Ros Mendoza L.H. Breast cancer in the 21st century: from early detection to new therapies.Radiologia. 2017; 59: 368-379Crossref PubMed Scopus (77) Google Scholar Triple-negative breast cancer (TNBC) cases account for nearly 13%–18% of breast cancer cases and have a worse prognosis than other subtypes of breast cancer.4Siegel R.L. Miller K.D. Jemal A. Cancer statistics.CA Cancer J. Clin. 2015; 65: 5-29Crossref PubMed Scopus (11400) Google Scholar Recently, TNBC has been intensely investigated, because it may lead to crucial clinical problems. TNBC has an aggressive nature. Patients with TNBC are relatively young, but they are usually diagnosed at the advanced stage, or even worse, they are more likely to have tumor metastasis, causing death.5Podo F. Buydens L.M. Degani H. Hilhorst R. Klipp E. Gribbestad I.S. Van Huffel S. van Laarhoven H.W. Luts J. Monleon D. et al.Triple-negative breast cancer: present challenges and new perspectives.Mol. Oncol. 2010; 4: 209-229Crossref PubMed Scopus (233) Google Scholar,6Carey L. Winer E. Viale G. Cameron D. Gianni L. Triple-negative breast cancer: disease entity or title of convenience?.Nat. Rev. Clin. Oncol. 2010; 7: 683-692Crossref PubMed Scopus (617) Google Scholar Therefore, we need to dig into the molecular mechanisms of TNBC and try to find a new and effective therapeutic target.RNAs with more than 200 nt and limited protein-coding capability are defined as long non-coding RNAs (lncRNAs).7St Laurent G. Wahlestedt C. Kapranov P. The Landscape of long noncoding RNA classification.Trends Genetics TIG. 2015; 31: 239-251Abstract Full Text Full Text PDF PubMed Scopus (718) Google Scholar lncRNAs have been studied and play an increasingly important role in biological functions of multiple cancer cells,8Geisler S. Coller J. RNA in unexpected places: long non-coding RNA functions in diverse cellular contexts.Nat. Rev. Mol. Cell Biol. 2013; 14: 699-712Crossref PubMed Scopus (1059) Google Scholar, 9Kondo Y. Shinjo K. Katsushima K. Long non-coding RNAs as an epigenetic regulator in human cancers.Cancer Sci. 2017; 108: 1927-1933Crossref PubMed Scopus (212) Google Scholar, 10Dey B.K. Mueller A.C. Dutta A. Long non-coding RNAs as emerging regulators of differentiation, development, and disease.Transcription. 2014; 5: e944014Crossref PubMed Scopus (261) Google Scholar including TNBC.11Wang L. Liu D. Wu X. Zeng Y. Li L. Hou Y. Li W. Liu Z. Long non-coding RNA (LncRNA) RMST in triple-negative breast cancer (TNBC): expression analysis and biological roles research.J. Cell. Physiol. 2018; 233: 6603-6612Crossref PubMed Scopus (57) Google Scholar,12Li P. Zhou B. Lv Y. Qian Q. LncRNA HEIH regulates cell proliferation and apoptosis through miR-4458/SOCS1 axis in triple-negative breast cancer.Hum. Cell. 2019; 32: 522-528Crossref PubMed Scopus (32) Google Scholar For instance, lncRNA GAS5 has been confirmed to be up-regulated in TNBC cells and to exert oncogenic influences on apoptosis of TNBC cells.13Li J. Li L. Yuan H. Huang X.W. Xiang T. Dai S. Up-regulated lncRNA GAS5 promotes chemosensitivity and apoptosis of triple-negative breast cancer cells.Cell Cycle. 2019; 18: 1965-1975Crossref PubMed Scopus (30) Google Scholar To date, lncRNAs have been studied in many important cancers and have been found to interact with many other cellular macromolecules.14Huarte M. The emerging role of lncRNAs in cancer.Nat. Med. 2015; 21: 1253-1261Crossref PubMed Scopus (1820) Google Scholar,15Evans J.R. Feng F.Y. Chinnaiyan A.M. The bright side of dark matter: lncRNAs in cancer.J. Clin. Invest. 2016; 126: 2775-2782Crossref PubMed Google Scholar lncRNA LUCAT1 has been identified as promoting tumorigenesis and metastasis of TNBC by sponging miR-5702.16Mou E. Wang H. LncRNA LUCAT1 facilitates tumorigenesis and metastasis of triple-negative breast cancer through modulating miR-5702.Biosci. Rep. 2019; 39 (BSR20190489)Crossref Scopus (25) Google Scholar In this study, we aimed to dig into the molecular functions of other lncRNAs in TNBC, which may provide us new insights into the study of cancer.Discs large MAGUK scaffold protein 1 antisense RNA 1 (DLG1-AS1) has been studied in a previous study, where it was found that it can act as an oncogene in cervical cancer (CC). More specifically, DLG1-AS1 can promote the proliferation of CC cells.17Rui X. Xu Y. Huang Y. Ji L. Jiang X. lncRNA DLG1-AS1 promotes cell proliferation by competitively binding with miR-107 and up-regulating ZHX1 expression in cervical cancer.Cell Physiol. Biochem. Int. J. Exp. Cell. Physiol. Biochem. Pharmacol. 2018; 49: 1792-1803Crossref PubMed Scopus (44) Google Scholar Moreover, DLG1-AS1 has been shown to facilitate TNBC cell proliferation by down-regulating miR-203.18Li S. LncRNA DLG1-AS1 promotes cancer cell proliferation in triple negative breast cancer by downregulating miR-203.J. Breast Cancer. 2020; 23: 343-354Crossref PubMed Scopus (5) Google Scholar Nevertheless, the role of DLG1-AS1 in TNBC cell migration and invasion had not been well explored. Therefore, this study focused on functions of DLG1-AS1 in TNBC cells. Further, Pre-B-cell leukemia homeobox 3 (PBX3) has been reported to have high expression in CC cells, which is associated with the poor overall survival of CC patients, and it promotes the growth of CC cells.19Li H. Sun G. Liu C. Wang J. Jing R. Wang J. Zhao X. Xu X. Yang Y. PBX3 is associated with proliferation and poor prognosis in patients with cervical cancer.OncoTargets Ther. 2017; 10: 5685-5694Crossref PubMed Scopus (19) Google Scholar PBX3 has also been revealed to be remarkably up-regulated in letrozole-resistant breast cancer (BC) cells and tissues and is linked to relatively unfavorable progression-free survival of BC patients.20Pang Z.Y. Wei Y.T. Shang M.Y. Li S. Li Y. Jin Q.X. Liao Z.X. Cui M.K. Liu X.Y. Zhang Q. Leptin-elicited PBX3 confers letrozole resistance in breast Cancer. PubMed Scopus Google Scholar In this study, we to the of DLG1-AS1 and PBX3 on TNBC cell growth. The of DLG1-AS1 was also in this