1.1.2. Exosomal lncRNAs (Long Non-coding RNAs)
The transfer of exosomal lncRNAs between the tumor microenvironment and
tumor cells is involved in events such as reprogramming the tumor
microenvironment, growth, migration, and survival of cancer cells, as
well as the development of mechanisms that cause resistance to
chemotherapy [88]. In addition, because exosomal lncRNAs play a role
in malignancy and response to treatment, they could be employed as
biomarkers for many cancers [88]. There is evidence that lncRNAs
promote drug resistance in diverse cancers [88]. For instance,
lncRNA SBF2 (SET binding factor 2) induces temozolomide resistance in
glioblastoma cells during chemotherapy [89]. During tumor growth,
access to oxygen is limited due to poor vasculature within the
developing solid tumor mass, which is called hypoxia [88]. Under
hypoxia conditions, the hypoxia-inducible factor (HIF)-1α pathway is
activated in tumor cells, which during oxygen stress, plays a role as an
adaptive mechanism [90]. Moreover, the
hypoxia condition promotes cell
survival through the transcription of several lncRNAs [91, 92].