MicroRNA (miRNA) actively participates in a broad range of cellular processes such as proliferation, differentiation, cell survival and apoptosis. Deregulated expression of miRNA may affect cell growth and eventually lead to cancer. In this study, we found that hsa-miR491-5p (miR491-5p) displays a significantly high level of expression in normal human pancreas tissue versus pancreatic cancer cells. Targeted site prediction indicated that both Bcl-XL and TP53 contain miR-491-5p recognizing sites in their 3' UTRs. Overexpression of miR-491-5p in the pancreatic cancer cell line SW1990 effectively inhibited both endogenous Bcl-XL and TP53 gene expressions. Mutagenesis at the seed match region of both targeted genes further confirmed the specificity of miR491-5p recognition. Cell proliferation rate was inversely related to the increased doses of miR-491-5p. Flow cytometric analysis showed that the proportions of total apoptotic and early apoptotic cells were significantly induced as the dose of miR491-5p increased. Moreover, a mechanistic study indicated that miR-R491-5p-mediated cell apoptosis was associated with the activation of intrinsic mitochondria mediated pathways. miR491-5p also markedly inhibited mitogenic signaling pathways such as STAT3 and PI-3K/Akt, but not Ras/MAPK. Thus, our results demonstrated that miR491-5p could effectively target both Bcl-xL and TP53 and induce cell apoptosis independent of TP53.

STYK1/NOK functions in a ligand independent and constitutive fashion to provoke tumor formation and to be up-regulated in many types of cancer cells. However, how STYK1/NOK functions at the whole animal level is completely unknown. Here, we found that STYK1/NOK-transgenic (tg) mice spontane-ously developed immunosuppressive B-CLL-like disease with generally shorter life spans. The phenotype of STYK1/NOK-induced B-CLL was typically heterogeneous, and most often, presented lymphadenectasis accompanied with hepatomegaly and/or splenomegaly. STYK1/NOK-tg mice also suffered reduced im-mune responses. The expanded CD5 thorn CD19 thorn (B1) lymphocyte pool was detected within peripheral lymphoid organs. Analysis on GEO profile revealed that expression of STYK1/NOK were significantly up -regulated in primary human B-CLL. Inoculation of blood cells from sick STYK1/NOK-tg mice into immune-deficient recipients recaptured the B1 malignant phenotype. Our study demonstrated that STYK1/NOK transgenic mouse may serve as a useful model system for the developments of novel diagnosis and treatment of B-CLL.(c) 2022 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).