Human interferon α2 (IFNα2) and thymosin α1 (Tα1) are therapeutic proteins used for the treatment of viral infections and different types of cancer. Both IFNα2 and Tα1 show a synergic effect in their activities when used in combination. Furthermore, the therapeutic fusion proteins produced through the genetic fusion of two genes can exhibit several therapeutic functions in one molecule. In this study, we determined the anticancer and antiviral effect of human interferon α2–thymosin α1 fusion protein (IFNα2–Tα1) produced in our laboratory for the first time. The cytotoxic and genotoxic effect of IFNα2–Tα1 was evaluated in HepG2 and MDA-MB-231 cells. The in vitro assays confirmed that IFNα2–Tα1 inhibited the growth of cells more effectively than IFNα2 alone and showed an elevated genotoxic effect. The expression of proapoptotic genes was also significantly enhanced in IFNα2–Tα1-treated cells compared to IFNα2-treated cells. Furthermore, the HCV RNA level was significantly reduced in IFNα2–Tα1-treated HCV-infected Huh7 cells compared to IFNα2-treated cells. The quantitative PCR analysis showed that the expression of various genes, the products of which inhibit HCV replication, was significantly enhanced in IFNα2–Tα1-treated cells compared to IFNα2-treated cells. Our findings demonstrate that IFNα2–Tα1 is more effective than single IFNα2 as an anticancer and antiviral agent.

Mitotic bookmarking, the retention of regulatory proteins and lncRNAs on chromatin during mitosis, epigenetically sustains competency for phenotype-specific gene expression in progeny cells. Gene expression is predominantly suppressed during mitosis. Bookmarking provides the guidance for the resumption of gene expression in progeny cells that is obligatory for physiological control of lineage commitment, specialized cell structure and phenotypic function. While regulatory continuity is supported by the persistence of genome-associated regulatory complexes, altered bookmarking mediates plasticity for responsiveness to physiological cues. Bookmarking fidelity ensures genome integrity and controls expression of tumor suppressors and proto-oncogenes. Cancer-compromised aberrations in bookmarking results in transcriptional dysregulation and the initiation of tumor-associated processes. Keywords: Mitotic Bookmarking, Mitosis, Epigenetic Control, Gene Expression, Cell Division

Background: Long noncoding RNAs (lncRNAs) are important regulators of gene expression and are frequently dysregulated in cancer. The mitotically associated lncRNA MANCR is highly expressed in aggressive cancers and contributes to genomic instability in triple-negative breast cancer (TNBC), but the molecular mechanisms underlying its activity remain poorly defined. Methods: Here we integrated computational and experimental approaches to examine the structure and regulatory interactions of MANCR isoforms. RNA-sequencing was performed in MDA-MB-231 and MCF10A cells and integrated with publicly available breast cancer transcriptomic datasets. MANCR-associated chromatin was characterized by ChIRP-seq in MDA-MB-231 cells. Computational analyses of patient data, sequence motifs, and molecular modeling suggested an interaction between MANCR and p53, which was investigated using RNA immunoprecipitation sequencing (RIP-seq) and a p53-responsive luciferase reporter assay. Results: Analysis of transcriptomic datasets revealed tumor-type-specific expression patterns for seven MANCR isoforms in breast cancer cell lines. Computational prediction of RNA secondary structures identified conserved structural features across isoforms, suggesting potential functional specialization. We identify p53 as a MANCR-associated protein through computational docking and RNA immunoprecipitation sequencing (RIP-seq) and demonstrate that MANCR depletion reduces p53-dependent transcriptional activity. Chromatin isolation by RNA purification sequencing (ChIRP-seq) revealed 1250 genomic regions associated with MANCR, including enrichment of p53 consensus motifs and GC-rich sequence elements. Motif analysis further identified candidate sequence features associated with MANCR-occupied chromatin regions. Conclusions: Together, these results suggest that MANCR may contribute to transcriptional regulation in TNBC in an isoform-specific manner through interactions with chromatin and p53 signaling pathways.