No abstract

Gastric cancer (GC) is one of the most common malignant tumors of the digestive system. The etiology of GC is complex, and much more attention should be paid to genetic factors. In this study, we explored the role and function of LINC00052 in GC. We applied qRT-PCR and Northern blot to detect the expression of LINC00052 and found it was highly expressed during GC. We also investigated the effects of LINC00052 on tumor prognosis and progression and found that LINC00052 indicated poor prognosis and tumor progression. By performing MTT, colony formation, and Transwell assays, we found that LINC00052 promoted MGC-803 cell proliferation and metastasis. Pull-down and RIP assays showed that LINC00052 could interact with β-catenin and methyltransferase SMYD2, and immunoprecipitation detection showed that LINC00052 promoted β-catenin methylation to maintain its stability, so as to activate the Wnt/β-catenin pathway. Furthermore, XAV939 (inhibitor of β-catenin) was used to treat MGC-803 cells, and we found that LINC00052 promoted proliferation and metastasis, possibly by activation of the Wnt/β-catenin pathway. In conclusion, our research demonstrated a carcinogenic role for LINC000052 in GC, which may represent a new approach for the prevention and therapy of this cancer.

Background: Pancreatic ductal adenocarcinoma (PDA) is one of the most serious causes of death in the world due to its high mortality and inefficacy treatments. MEX3A was first identified in nematodes and was associated with tumor formation and may promote cell proliferation and tumor metastasis. So far, nothing is known about the relationship between MEX3A and PDA. Methods:In this study, the expression level of MEX3A in PDA tissues was measured by immunohistochemistry. The qRT-PCR and western blot were used to identify the constructed MEX3A knockdown cell lines, which was further used to construct mouse xenotransplantation models. Cell proliferation, colony formation, cell apoptosis and migration were detected by MTT, colony formation, flow cytometry and Transwell.Results: This study showed that MEX3A expression is significantly upregulated in PDA and associated with tumor grade. Loss-of-function studies showed that downregulation of MEX3A could inhibit cell growth in vitro and in vivo. Moreover, it was demonstrated that knockdown of MEX3A in PDA cells promotes apoptosis by regulating apoptosisrelated factors, and inhibits migration through influencing EMT. At the same time, the regulation of PDA progression by MEX3A involves changes in downstream signaling pathways including Akt, p-Akt, PIK3CA, CDK6 and MAPK9. Conclusions:We proposed that MEX3A is associated with the prognosis and progression of PDA,which can be used as a potential therapeutic target.

In this study, we examined whether and how miR-545 modulates ferroptosis in colorectal cancer (CRC). HT-29 and HCT-116 human CRC cell viability was examined using a CCK-8 assay and malondialdehyde (MDA) and Fe 2+ levels were measured after treatment with the ferroptosis inducers Eradicator of Ras and ST (erastin) and Ras selective lethal 3 (RSL3) with or without miR-545 overexpression or knockdown vectors. Our results demonstrate that miR-545 overexpression inhibited, while miR-545 knockdown further increased, erastin and RSL3-induced upregulation of MDA, reactive oxygen species (ROS), and Fe 2+ levels. Similarly, miR-545 overexpression partially reversed, while miR-545 knockdown enhanced, the erastin and RSL3-induced reduction in HT-29 and HCT-116 cell survival rates. Transferrin (TF) was identified as a target gene of miR-545. To determine whether miR-545 suppresses ferroptosis via TF, we overexpressed TF in HT-29 and HCT-116 cells. We found that TF overexpression blocked miR-545-induced changes in ROS, MDA, and Fe 2+ levels in HT-29 and HCT-116 cells, thereby inducing CRC cell death. An in vivo assay showed that inhibition of miR-545 decreased tumor growth in nude mice treated with erastin. Together, these findings indicate that miR-545 promotes CRC cell survival by suppressing TF.