g RNA Researchjournal homepage: keaipublishing/en/journals/non-coding-rna-researchmicroRNAs in cancer chemoresistance: The sword and also the shieldPriya Mondal a, b, Syed Musthapa Meeran a, b, a bDepartment of Biochemistry, CSIR-Central Meals Technological Investigation Institute, Mysore, 570020, India Academy of Scientific and Revolutionary Research (AcSIR), Ghaziabad, 201002, IndiaA R T I C L E I N F OKeywords: Cancer Noncoding RNA Multi-drug resistance Autophagy miRNA HypoxiaA B S T R A C TCancer is a multifactorial disease and among the major causes of mortality worldwide. Cancer cells develop numerous strategies to lower drug sensitivity and eventually result in chemoresistance. Toxoplasma MedChemExpress Chemoresistance is initiated either by intrinsic components or due to the prolonged use of chemotherapeutics as acquired resistance. Further, chemoresistance can also be certainly one of the key causes behind tumor recurrence and metastasis. For that reason, overcoming chemoresistance is amongst the main challenges in cancer therapy. A number of mechanisms are involved in chemoresistance. Among them, the essential role of ABC transporters and tumor microenvironment have been effectively studied. Lately, microRNAs (miRNAs) regulation in tumor improvement, metastasis, and chemotherapy has got wider interest as a result of its part in regulating genes involved in cancer progression and therapy. Noncoding RNAs, including miRNAs, have been linked using the regulation of tumor-suppressor and tumor-promoter genes. Further, miRNA also can be employed as a trustworthy diagnostic and prognostic marker to predict the stage and sorts of cancer. Current evidences have revealed that miRNAs regulation also influences the function of drug transporters and also the tumor microenvironment, which impacts chemosensitivity to cancer cells. As a result, miRNAs can be a promising target to reverse back chemosensitivity in cancer cells. This overview comprehensively discusses the mechanisms involved in cancer chemoresistance and its regulation by miRNAs.1. Introduction Cancer is one of the major non-communicable illnesses and also the top trigger of death worldwide. Chemotherapy may be the most usually preferred therapeutic method due to the fact of its effectiveness and widespread availability. Even so, the majority of the chemotherapies bring about adverse side effects, along with the long-time use induces chemoresistance. Chemoresistance is a mechanism when the prolonged use of an anticancer agent or maybe a group of anticancer agents fails to show its anti-cancerous house towards cancer cells and allows cancer cells or tumors to grow and metastasize into other organs aggressively. Chemoresistance is mostly of two types which include innate-chemoresistance and acquiredchemoresistance [1]. Majorly, three variables are involved in drug resistance: very first, decreased intake of the drugs inside the cell or increased release of drugs outdoors of the cell. The second will be the degradation and deactivation of intracellular thiols, and also the third is the sophisticated intracellular DNA repair mechanism. Apart from these, quite a few things like, Akt1 Inhibitor review mutation, hypoxia, cancer stem cells, and epigenetic modifications, are involved within the regulation of chemoresistance [2,3]. Amongst them,noncoding RNAs (ncRNAs), one of the fundamental epigenetic modifications, play a vital part in chemoresistance. ncRNAs are endogenous, single-stranded RNAs which can modulate the expression of receptors and genes involved in cancer chemoresistance. ncRNAs are also called epigenetic modifiers, as they regulate gene expression by modifying loca