• Functional roles of long-noncoding RNA MALAT1 in breast cancer
  • Farnaz Rezaei,1 Mehrzad Niknahad,2 Tina S. Emami,3 Mahshid Deldar,4,*
    1. Department of Cellular and Molecular Biology, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
    2. Department of Cellular and Molecular Biology, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
    3. Department of Biology, Faculty of Biological Sciences, Central Tehran Branch, Islamic Azad University, Tehran, Iran
    4. Farhikhtegan Medical Convergence Sciences Research Center, Farhikhtegan Hospital Tehran Medical Sciences


  • Introduction: Introduction: Breast cancer (BC) is the second most prevalent malignancy in women, which has been increasing worldwide. The two invasive types of breast cancer based on histology are invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC), that IDC accounts for roughly 70 to 80 percent of all cases and a major cause of cancer-related death in women globally. Although recent studies investigated that over expression of MALAT1 has been implicated in the carcinogenesis of various cancers including BC, understanding functional roles of MALAT1 in breast cancer is crucial for developing targeted therapies that can disrupt its activities and improve treatment outcomes for patients with this challenging disease. Beside 2% of genome which is coded to protein, more than 98% of human genome is transcribed into ncRNAs. LncRNAs are a class of ncRNA which are defined as RNAs longer than 200 nucleotides that are not translated into functional proteins. LncRNAs have crucial roles in part of the epigenetic regulatory network, transcription and post-transcriptional regulation. Among the numerous lncRNAs that have been associated with various malignancies of multiple organs, including breast, the long non-coding RNA Metastasis-associated lung adenocarcinoma transcript 1 (lncRNA MALAT1) has gained significant attention due to its functional role in breast cancer, impacting various aspects of tumor biology and contributing to disease progression. This comprehensive study focused on the functional role of MALAT1 in breast cancer progression, exploring its impact on cellular processes and its potential as a diagnostic and prognostic marker.
  • Methods: Methods: This research was performed using articles published in various databases, including PubMed, Semantic Scholar, Science Direct, Google Scholar and Cochrane between March 2014 and August 2023 then 45 references related to our keywords were reviewed.
  • Results: Results: It is exciting to study the functional role played by MALAT1 in breast cancer that reveals its multifaceted impact on various aspects of tumorigenesis and disease progression. The accumulated evidence underscores MALAT1 as a key player in breast cancer pathogenesis. Proliferation and Survival: Tripathi et al. showed that MALAT1 influences breast cancer cell proliferation by regulating the expression of cell cycle-related genes. Its upregulation results in increased cell division, driving tumor growth. Moreover, MALAT1's interaction with epigenetic modifiers contributes to cell survival, further promoting oncogenesis. Epithelial-to-Mesenchymal Transition (EMT): Earlier, Banyard et al. investigated that EMT is a critical process in cancer metastasis, and MALAT1's role in inducing EMT is well-established. By modulating EMT-related genes, MALAT1 facilitates the transformation of epithelial breast cancer cells into more invasive, mesenchymal-like phenotypes, ultimately enhancing the metastatic potential of tumors. Metastasis Promotion: Beyond EMT, MALAT1 enhances the migratory and invasive capabilities of breast cancer cells, facilitating their spread to distant sites. This metastatic promotion is a hallmark of advanced breast cancer and is associated with poor patient outcomes. Chemoresistance: Wu et al. underscore MALAT1's contribution to chemoresistance in breast cancer. Its upregulation is associated with decreased sensitivity to commonly used chemotherapeutic agents, presenting a significant clinical challenge. Competing Endogenous RNA (ceRNA) Activity: According to Yang et al. MALAT1's ceRNA function, whereby it sponges microRNAs (miRNAs), results in the activation of oncogenes and the suppression of tumor suppressor genes. This intricate mechanism of gene regulation impacts various signaling pathways, ultimately driving tumor progression. Diagnostic and Prognostic Marker: Wang et al, studied MALAT1's upregulation in breast cancer tissues that has been proposed as a diagnostic and prognostic marker. Elevated MALAT1 levels are associated with more aggressive tumor characteristics and poorer clinical outcomes.
  • Conclusion: Conclusion: To recapitulate, understanding MALAT1's functions in breast cancer not only deepens our knowledge of the molecular mechanisms underlying the disease but also presents therapeutic opportunities. Targeting MALAT1 through RNA-based strategies or small molecules may disrupt its oncogenic activities and improve treatment outcomes for breast cancer patients. Furthermore, this review emphasizes the importance of continued research in this area to unravel additional intricacies of MALAT1's functions and to translate these findings into clinical applications, ultimately benefiting those affected by breast cancer.
  • Keywords: Keywords: Breast cancer, MALAT1, LncRNA