Panel A shows a vertical bar graph depicting normalized RNA levels of MALAT1 in PC9 cells treated with Osimertinib for different days. The x-axis represents the treatment duration in days, including Naive, DTP, and OR conditions. The y-axis shows normalized RNA levels. The graph indicates individual values and mean standard deviation for three biological replicates, with significant differences marked by asterisks. Panel B illustrates a model of cell cycle-dependent regulation of MALAT1 abundance. It shows the gradual accumulation of newly transcribed MALAT1 in early G1 to late G2 nuclei, followed by its decay in the cytoplasm post-mitosis. In non-proliferative cells, MALAT1 continuously accumulates in the nuclei.
Cell dormancy enables MALAT1 overexpression in cancer. (A) qRT-PCR analysis of normalized MALAT1 RNA levels in PC9 cells treated with 100 nM Osi for the indicated days (d). OR, Osi resistant. OR cells are cultured in the presence of 100 nM Osi. Bar graph shows individual values and mean ± SD of n = 3 biological replicates, paired t test, ***P < 0.01. (B) Model for cell cycle–dependent regulation of MALAT1 abundance, showing gradual accumulation of newly transcribed MALAT1 (red) in early G1 to late G2 nuclei, followed by dissociation from chromatin in mitosis and decay of post-mitotically inherited MALAT1 (green) in the cytoplasm. In the absence of passage through mitosis, continuously transcribed MALAT1 (orange) accumulates in the nuclei of senescent, quiescent, cell cycle–arrested, or dormant cells.