g RNA Researchjournal homepage: keaipublishing/en/journals/non-coding-rna-researchmicroRNAs in cancer chemoresistance: The sword plus the shieldPriya Mondal a, b, Syed Musthapa Meeran a, b, a bDepartment of Biochemistry, CSIR-Central Food Technological Study Institute, Mysore, 570020, India Academy of Scientific and Revolutionary Investigation (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 often a multifactorial disease and among the top causes of mortality worldwide. Cancer cells develop various techniques to cut down drug sensitivity and at some point bring about chemoresistance. Chemoresistance is initiated either by intrinsic PAK3 Species elements or as a result of prolonged use of chemotherapeutics as acquired resistance. Additional, chemoresistance can also be one of the major causes behind tumor recurrence and metastasis. Hence, overcoming chemoresistance is among the main challenges in cancer therapy. A number of mechanisms are involved in chemoresistance. Among them, the crucial role of ABC transporters and tumor microenvironment happen to be well studied. Lately, microRNAs (miRNAs) regulation in tumor improvement, metastasis, and chemotherapy has got wider interest resulting from its role in regulating genes involved in cancer progression and therapy. Noncoding RNAs, such as miRNAs, have already been related using the regulation of tumor-suppressor and tumor-promoter genes. Additional, miRNA may also be used as a reliable diagnostic and prognostic marker to predict the stage and types of cancer. Recent evidences have revealed that miRNAs regulation also influences the function of drug transporters and also the tumor microenvironment, which impacts chemosensitivity to cancer cells. Thus, miRNAs is usually a promising target to reverse back chemosensitivity in cancer cells. This assessment comprehensively discusses the mechanisms involved in cancer chemoresistance and its regulation by miRNAs.1. Introduction Cancer is amongst the big non-communicable PARP15 Formulation diseases and the leading cause of death worldwide. Chemotherapy would be the most usually preferred therapeutic strategy since of its effectiveness and widespread availability. However, most of the chemotherapies result in adverse side effects, and the long-time use induces chemoresistance. Chemoresistance is actually a mechanism when the prolonged use of an anticancer agent or perhaps a group of anticancer agents fails to show its anti-cancerous house towards cancer cells and allows cancer cells or tumors to develop and metastasize into other organs aggressively. Chemoresistance is mostly of two kinds including innate-chemoresistance and acquiredchemoresistance [1]. Majorly, 3 elements are involved in drug resistance: very first, decreased intake from the drugs inside the cell or improved release of drugs outdoors in the cell. The second is definitely the degradation and deactivation of intracellular thiols, and also the third is the advanced intracellular DNA repair mechanism. Besides these, many elements such as, mutation, hypoxia, cancer stem cells, and epigenetic adjustments, are involved within the regulation of chemoresistance [2,3]. Amongst them,noncoding RNAs (ncRNAs), one of the basic epigenetic modifications, play a vital function in chemoresistance. ncRNAs are endogenous, single-stranded RNAs which will modulate the expression of receptors and genes involved in cancer chemoresistance. ncRNAs are also known as epigenetic modifiers, as they regulate gene expression by modifying loca