Project description:Breast cancer subtype-specific lncRNAs AL078604.2 and LINC01269 were knockdown in breast cancer cell lines LncRNA AL078604.2 was knockdown by an anti-AL076804.2 antisense oligonucleotides (ASOs) in triple-negative breast cancer cell lines MDA-MB-231 and MDA-MB-468 breast cancer cells. LncRNA LINC01269 was knockdown by an anti-LINC01269 ASOs in HER2+ SKBR3 breast cancer cells. To ensure the initial presence of AL078604.2 and LINC01269 in their respective cell lines, qPCR analysis was performed to confirm their expression levels prior to knockdown experiments. The effectiveness of knockdown was confirmed by qPCR analysis, which validated the reduction in AL078604.2 and LNC01269 expression in their corresponding cell lines following ASO treatment.
Project description:Background: Estrogen receptor-positive (ER+) breast cancers represent approximately two-thirds of all breast cancers and have a sustained risk of late disease recurrence. Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors have shown significant efficacy in ER+ breast cancer. However, their effects are still limited by drug resistance. In this study, we aim to explore the role of long noncoding RNA TROJAN in ER+ breast cancer. Methods: The expression level of TROJAN in breast cancer tissue and cell lines was determined by quantitative real-time PCR. In vitro and in vivo assays as well as patient derived organoids were preformed to explore the phenotype of TROJAN in ER+ breast cancer. The TROJAN-NKRF-CDK2 axis were screened and validated by RNA pull-down, mass spectrometry, RNA immunoprecipitation, microarray, dual-luciferase reporter and chromatin immunoprecipitation assays. Results: Herein, we showed that TROJAN was highly expressed in ER+ breast cancer. TROJAN promoted cell proliferation and resistance to a CDK4/6 inhibitor and was associated with poor survival in ER+ breast cancer. TROJAN can bind to NKRF and inhibit its interaction with RELA, upregulating the expression of CDK2. The inhibition of TROJAN abolished the activity of CDK2, reversing the resistance to CDK4/6 inhibitor. A TROJAN antisense oligonucleotide sensitized breast cancer cells and organoids to the CDK4/6 inhibitor palbociclib both in vitro and in vivo. Conclusions: TROJAN promotes ER+ breast cancer proliferation and is a potential target for reversing CDK4/6 inhibitor resistance.
Project description:To identify biologically and clinically novel lncRNAs potentially involved in the progression of breast cancer, we profiled the expression of lncRNAs in two stage III triple-negativebreast cancer tissues and their paired adjacent noncancerous tissues by LncRNA Array 3.0 (ArrayStar). Expression of the mostly upregulated lncRNA (BCAR4) from this signature was quantified in the breast caner tissue microarray by RNA In situ Hybridization and bioinformatic analysis of Oncomine database, confirming its correlation with breast cancer metastasis.
Project description:Purpose: Identified the expression profile of lncRNAs associated to neoadjuvant chemotherapy response in 47 luminal B tumors of locally advanced breast cancer patients Methods: We implemented the transcriptomic analysis from 47 luminal B breast cancer samples by paired-end RNA-Seq, as a case-control study (responders vs nonresponders group). Differential expression analysis for lncRNA and mRNA were made to identify lncRNA as predictive biomarkers. Results: We identified a signature of lncRNAs associated with nonresponders group. Additionally, we identified the pathways were differentially expressed lncRNA and mRNA are associated in neoadjuvant chemotherapy response. Additionally, we proposed the clinical application of lncRNA GATA3-AS1 as a predictive biomarker to neoadjuvant chemotherapy response in luminal B breast cancer patients detected by RNA-ISH. Conclusion: we propose the clinical utility of lncRNA GATA3-AS1 detected by RNA-ISH to identify luminal B breast cancer patients that will not respond to neoadjuvant chemotherapy.