The potential roles of lncRNAs DUXAP8, LINC00963, and FOXD2-AS1 in luminal breast cancer based on expression analysis and bioinformatic approaches

New insights of LncRNAs fingerprints in breast cancer progression: Tumorigenesis, drug resistance, and therapeutic opportunities

Breast cancer (BC) is one of the common female cancers and it is characterized by considerable problems regarding its development and therapy. Long non-coding RNAs (lncRNAs) have been identified as significant modulators in BC development, especially, in tumorigenicity and chemoresistance. We therefore endeavor to present an up-to-date understanding of lncRNAs and their impact on BC progression and treatment, concerning molecular processes, treatment options, and use as a therapeutic opportunity. LncRNAs are novel regulators of genes that cause therapeutic resistance and directly impact the functioning of both coding and non-coding genes in BC patients, but little is known about their mechanisms of actions. Thus, additional study is required to have a deeper understanding of their modes of action and possible roles in BC disease. This study aims to investigate the functions of lncRNAs in the development of BC, with particular attention to their role in tumorigenesis, drug resistance mechanisms, and therapeutic targets. This will help to identify novel therapeutic targets and improve the effectiveness of BC treatment.

A review on the role of FOXD2-AS1 in human disorders

FOXD2 adjacent opposite strand RNA 1 (FOXD2-AS1) is a long non-coding RNA being transcribed from a locus on chromosome 1p33. This transcript has been found to be up-regulated in tumor samples of almost all types of malignancies in association with a significant increase in malignant features. FOXD2-AS1 can affect activity of PI3K/AKT, AKT/mTOR, Hippo/YAP, Notch, NRf2, Wnt/β-catenin, NF-ƙB and ERK/MAPK pathways. Furthermore, it can enhance stem cell properties in cancer cells and prompt epithelial-mesenchymal transition. It is also involved in induction of resistance to a variety of anticancer agents such as adriamycin, cisplatin, 5-fluorouracil, temozolomide and gemcitabine. This article summarizes the impact of FOXD2-AS1 in diverse human disorders.

A systematic review and meta-analysis of long noncoding RNA 00963 expression and prognosis and clinicopathological characteristic in human cancers

BACKGROUND

Numerous studies have indicated that the aberrant expression of LINC00963 is extensively present in various human tumors, and that dysregulation of LINC00963 is implicated in the initiation and progression of human cancers. In this meta-analysis, data from diverse malignancies were analyzed to determine whether LINC00963 expression levels were associated with clinical prognosis and immune infiltration in pan-cancer.

MATERIALS AND METHODS

The eligible studies were identified from several electronic databases from the inception to July 2022 through systematic research. LINC00963 expression and survival were estimated using pooled odds ratios and hazard ratios with 95% CI. We used the Kaplan-Meier method and COX analysis for survival analysis. In addition, Spearman's correlation analysis was used to uncover any correlation between LINC00963 and microsatellites instability (MSI), tumor mutational burden (TMB), DNA methyltransferases (DNMTs), immune checkpoint biomarkers, and the related genes of mismatch repair (MMR).

RESULTS

Our findings indicated that overexpression of LINC00963 was related to poor overall survival (OS) (HR =1.32, 95% CI, 1.09-1.59, P = 0.004). The TCGA database also found that abnormal expression of LINC00963 was linked to overall survival in various cancers. Moreover, there is an association between LINC00963 expression and MSI, TMB, and MMR in malignancies of various types.

CONCLUSION

The results of this study indicate that LINC00963 may serve as a prognostic biomarker and a therapeutic target for cancer. By using it, cancer diagnoses can be improved, treatment targets discovered, and prognostic questions improved.

LncRNA DUXAP8 as a prognostic biomarker for various cancers: A meta-analysis and bioinformatics analysis

Background: Dual homeoboxes A pseudogene 8 (DUXAP8) is a newly discovered long noncoding RNA that has been shown to function as an oncogene in a variety of human malignant cancers. By integrating available data, this meta-analysis sought to determine the relationship between clinical prognosis and DUXAP8 expression levels in diverse malignancies.

Materials and methods: A systematic search was performed to identify eligible studies from several electronic databases from their inception to 25 October 2021. Pooled odds ratios and hazard ratios with 95% CI were used to estimate the association between DUXAP8 expression and survival. For survival analysis, the Kaplan-Meier method and COX analysis were used. Furthermore, we utilized Spearman’s correlation analysis to explore the correlation between DUXAP8 and tumor mutational burden (TMB), microsatellite instability (MSI), the related genes of mismatch repair (MMR), DNA methyltransferases (DNMTs), and immune checkpoint biomarkers.

Results: Our findings indicated that overexpression of DUXAP8 was related to poor overall survival (OS) (HR = 1.63, 95% CI, 1.49–1.77, p < 0.001). In addition, elevated DUXAP8 expression was closely related to poor OS in several cancers in the TCGA database. Moreover, DUXAP8 expression has been associated with TMB, MSI, and MMR in a variety of malignancies.

Conclusion: This study revealed that DUXAP8 might serve as a prognostic biomarker and potential therapeutic target for cancer. It can be used to improve cancer diagnosis, discover potential treatment targets, and improve prognosis.

LINC00963: A potential cancer diagnostic and therapeutic target

Long intergenic noncoding RNA 00963 (LINC00963) is located on human chromosome 9q34.11. Aberrantly expressed LINC00963 often exerts oncogenic effects by regulating various cellular processes including proliferation, migration, invasion, EMT, and apoptosis. Overexpressed LINC00963 is associated with cancer clinicopathological features and poor cancer prognosis, and can be used in the diagnosis of hepatocellular carcinoma. LINC00963 can build a complex ceRNA network by competitively binding to 22 miRNAs in 14 cancers. LINC00963 can also directly regulate four downstream protein-coding genes. Specifically, LINC00963 promotes the transition of prostate cancer from an androgen-dependent mode to an androgen-independent mode by participating in the transactivation of EGFR. LINC00963 can bind EZH2 and inhibit p21 expression, thereby promoting glioma cell proliferation and invasion. In non-small cell lung cancer, LINC00963 can recruit NONO and CRTC, forming a positive feedback loop of LINC00963/NONO/CRTC/CREB/LINC00963, thereby promoting cancer cell metastasis. LINC00963 is involved in the PI3K/AKT signaling pathway, Wnt signaling pathway, AMPK signaling pathway, and MAPK signaling pathway. Furthermore, LINC00963 is associated with drug resistance in oral squamous cell carcinoma (cisplatin and 5-fluorouracil) and gastric cancer (oxaliplatin) and predicts neoadjuvant efficacy of taxane-anthracyclines in breast cancer. This work systematically reviewed the clinical value of abnormal expression of LINC00963 in various tumors, demonstrated the complex molecular mechanism of LINC00963, and provided directions for future related research.

Down-Regulated miR-130a/b Attenuates Rhabdomyosarcoma Proliferation via PPARG

Background: Rhabdomyosarcoma (RMS) is one of the most common types of soft-tissue sarcomas in children, and it exhibits a low 5-years survival rate. The survival outcome has shown no significant improvements in the past 30 years miRNA profiling of RMS might therefore provide a novel insight into uncovering new molecular targets for therapy.

Methods: We analyzed miRNA and RNA sequencing data from patients and the TARGET database to reveal the potential miRNA-mRNA axes and validated them in patients’ samples. After the miRNA antagomirs were used to silence the target miRNAs in the cell model, qRT-PCR, western immunoblotting analysis, and proliferation assays were performed to explore the interaction between miR-130a/b and peroxisome proliferator-activated receptor gamma (PPARG) and their effects.

Results: In RMS patients, the expression of miR-130a/b was augmented, and its related PPARG gene was suppressed. Bioinformatics analysis showed that miR-130a/b targeted the PPARG gene and inhibited the proliferation of human RMS cell lines. In addition, rosiglitazone maleate activated the expression of PPARG in human RMS cell lines to suppress proliferation.

Conclusion: miR-130a/b regulates the malignant process in RMS by targeting PPARG. Furthermore, the PPARG agonist rosiglitazone maleate attenuated the proliferation of RD cells and might therefore be of benefit to RMS patients.