Long non-coding RNAs as a determinant of cancer drug resistance: Towards the overcoming of chemoresistance via modulation of lncRNAs

Emerging role of long non-coding RNAs in cancer chemoresistance: unravelling the multifaceted role and prospective therapeutic targeting

Chemotherapy is one of the important treatment modules in early as well as advanced stages of cancer. However, the major limitation of chemotherapy is the development of chemoresistance in the transformed cells of cancer patients, which leads to cancer recurrence. Long non-coding RNAs (lncRNA) are the transcripts longer than 200 nucleotides in length, which are reported to associate with the initiation, progression, recurrence, and metastasis of different cancers. Several lncRNAs have been implicated in the prevalence of chemoresistant phenotypes and also in the restoration of drug sensitivity in chemoresistant cells. LncRNAs such as HOTAIR, H19, and a lot more are involved in the chemoresistance of cancer cells. Therefore, targeting the lncRNAs may serve as a novel strategy for treating chemoresistant cancer. This review throws light on the role of lncRNA in chemoresistance along with the perspective of the therapeutic targets for the treatment of multiple cancers.

Long noncoding RNA loss in immune suppression in cancer

Long noncoding RNAs (lncRNAs) have multiple functions in the regulation of cellular homeostasis. In recent years, numerous studies have shown that tumor-associated lncRNAs play key roles in promoting and maintaining tumor initiation and progression by shaping the tumor microenvironment through changing tumor cell intrinsic properties. Here, we focus on the roles of lncRNAs in cancer immunology. In the first part, we provide an overview of the roles played by lncRNAs and their deregulation in cancer at the cancer cell- and tumor microenvironment-associated immune cell levels. We go on to describe preclinical strategies for targeting lncRNAs, particularly highlighting the effects on tumor microenvironments. We then discuss the possibility of combining lncRNA targeting and tumor immune checkpoint inhibitor antibodies to treat cancer.

Secondary Resistant Mutations to Small Molecule Inhibitors in Cancer Cells

Secondary resistant mutations in cancer cells arise in response to certain small molecule inhibitors. These mutations inevitably cause recurrence and often progression to a more aggressive form. Resistant mutations may manifest in various forms. For example, some mutations decrease or abrogate the affinity of the drug for the protein. Others restore the function of the enzyme even in the presence of the inhibitor. In some cases, resistance is acquired through activation of a parallel pathway which bypasses the function of the drug targeted pathway. The Catalogue of Somatic Mutations in Cancer (COSMIC) produced a compendium of resistant mutations to small molecule inhibitors reported in the literature. Here, we build on these data and provide a comprehensive review of resistant mutations in cancers. We also discuss mechanistic parallels of resistance.