PCR-detected genome polymorphism in malignant cell growth

Dysregulation of Transposon Transcription Profiles in Cancer Cells Resembles That of Embryonic Stem Cells

Transposable elements (TEs) comprise a substantial portion of the mammalian genome, with potential implications for both embryonic development and cancer. This study aimed to characterize the expression profiles of TEs in embryonic stem cells (ESCs), cancer cell lines, tumor tissues, and the tumor microenvironment (TME). We observed similarities in TE expression profiles between cancer cells and ESCs, suggesting potential parallels in regulatory mechanisms. Notably, four TE RNAs (HERVH, LTR7, HERV-Fc1, HERV-Fc2) exhibited significant downregulation across cancer cell lines and tumor tissues compared to ESCs, highlighting potential roles in pluripotency regulation. The strong up-regulation of the latter two TEs (HERV-Fc1, HERV-Fc2) in ESCs has not been previously demonstrated and may be a first indication of their role in the regulation of pluripotency. Conversely, tandemly repeated sequences (MSR1, CER, ALR) showed up-regulation in cancer contexts. Moreover, a difference in TE expression was observed between the TME and the tumor bulk transcriptome, with distinct dysregulated TE profiles. Some TME-specific TEs were absent in normal tissues, predominantly belonging to LTR and L1 retrotransposon families. These findings not only shed light on the regulatory roles of TEs in both embryonic development and cancer but also suggest novel targets for anti-cancer therapy. Understanding the interplay between cancer cells and the TME at the TE level may pave the way for further research into therapeutic interventions.

Study of the cytotoxic effects of 2,5-diaziridinyl-3,6-dimethyl-1,4-benzoquinone (MeDZQ) in mouse hepatoma cells

A number of quinones have been shown to be efficient anticancer agents. However, some mechanisms of their action, in particular cell signaling are not well understood. The aim of this study was to partly fill this gap by characterizing the mode of cytotoxicity of 2,5-diaziridinyl-3,6-dimethyl-1,4-benzoquinone (MeDZQ) in malignant mouse hepatoma cells (MH-22A) with regard to the expression and activation of main molecules in MAPK cell signaling pathway. The study revealed unequal roles of MAP kinases in MeDZQ-induced cell death: the compound did not induce significant changes in ERK expression or its phosphorylation; JNK appeared to be responsible for cell survival, however, p38 kinase was shown to be involved in cell death. In order to assess the enzymatic activation mechanisms responsible for the action of MeDZQ, we have also found that the antioxidant N,N'-diphenyl-p-phenylene diamine, the iron-chelating agent desferrioxamine, and DT-diaphorase inhibitor, dicoumarol, partly protected the cells from MeDZQ cytotoxicity. It points to parallel oxidative stress and bioreductive alkylation modes of the cytotoxicity of MeDZQ.