title: An outline of main factors of drug resistance influencing cancer therapy.
abstract: Drug resistance in cancer therapy is a multifactorial phenomenon that determines remission or progression. It is known that resistance to used anticancer drugs may be the consequence of drug transport to the cell or intracellular distribution. It may also be the result of its molecular target structural change, apoptosis inhibition or increase in some enzymes activity, e.g. pentose phosphate pathway enzymes. Intrinsic (pre-existed) drug resistance is related to the phenotype of cancer as well as normal cells. Acquired, after partial administration of chemotherapy, type of drug resistance in addition to the starting phenotype is closely linked to the development of new more aggressive clones and adaptive processes. In both, the intrinsic and acquired resistance, role play also mutations. These may be partially spontaneous, but in terms of acquired resistance, they are mostly induced by the exposure to the drugs. The article mentions some traditional mechanisms related to the acquisition of resistance by cancer cells during therapy, through the protein transporters, apoptosis deregulation, angiogenesis and the impact of the tumour microenvironment. We focused however on some more alternative ways of therapy resistance, such as, hypoxia and tumour acidification, cancer stem cells (CSCs), exosomes and radiotherapy resistance. A concise summary of the drug resistance presented in the paper may be an important aspect in studies to increase the effectiveness of cancer therapies.
authors.affiliation: a Department of Toxicology with Independent Medical Biology Unit , Medical University of Lublin , Lublin , Poland.
authors.forename: Natalia
authors.initials: N
authors.lastname: Frączek
authors.affiliation: a Department of Toxicology with Independent Medical Biology Unit , Medical University of Lublin , Lublin , Poland.
authors.forename: Iwona
authors.initials: I
authors.lastname: Bronisz
authors.affiliation: a Department of Toxicology with Independent Medical Biology Unit , Medical University of Lublin , Lublin , Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Pietryka
authors.affiliation: a Department of Toxicology with Independent Medical Biology Unit , Medical University of Lublin , Lublin , Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Kępińska
authors.affiliation: a Department of Toxicology with Independent Medical Biology Unit , Medical University of Lublin , Lublin , Poland.
authors.forename: Patrycja
authors.initials: P
authors.lastname: Strzała
authors.affiliation: a Department of Toxicology with Independent Medical Biology Unit , Medical University of Lublin , Lublin , Poland.
authors.forename: Kamila
authors.initials: K
authors.lastname: Mielnicka
authors.affiliation: a Department of Toxicology with Independent Medical Biology Unit , Medical University of Lublin , Lublin , Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Korga
authors.affiliation: a Department of Toxicology with Independent Medical Biology Unit , Medical University of Lublin , Lublin , Poland.
authors.forename: Jaroslaw
authors.initials: J
authors.lastname: Dudka
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D000970:Antineoplastic Agents / Q000627:therapeutic use; D017209:Apoptosis; D015687:Cell Hypoxia; D019008:Drug Resistance, Neoplasm; D055354:Exosomes / Q000378:metabolism; D006801:Humans; D009369:Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy; D014411:Neoplastic Stem Cells / Q000502:physiology; D011836:Radiation Tolerance; D059016:Tumor Microenvironment
chemical_list: D018528:ATP-Binding Cassette Transporters; D000970:Antineoplastic Agents
keywords: Cancer; Chemotherapy; Drug resistance; Hypoxia; Review; Tumour