Breast Cancer/Stromal Cells Coculture on Polyelectrolyte Films Emulates Tumor Stages and miRNA Profiles of Clinical Samples

MicroRNA-34 Family in Cancers: Role, Mechanism, and Therapeutic Potential

MicroRNA (miRNA) are small noncoding RNAs that play vital roles in post-transcriptional gene regulation by inhibiting mRNA translation or promoting mRNA degradation. The dysregulation of miRNA has been implicated in numerous human diseases, including cancers. miR-34 family members (miR-34s), including miR-34a, miR-34b, and miR-34c, have emerged as the most extensively studied tumor-suppressive miRNAs. In this comprehensive review, we aim to provide an overview of the major signaling pathways and gene networks regulated by miR-34s in various cancers and highlight the critical tumor suppressor role of miR-34s. Furthermore, we will discuss the potential of using miR-34 mimics as a novel therapeutic approach against cancer, while also addressing the challenges associated with their development and delivery. It is anticipated that gaining a deeper understanding of the functions and mechanisms of miR-34s in cancer will greatly contribute to the development of effective miR-34-based cancer therapeutics.

ADAM28 from both endothelium and gastric cancer cleaves von Willebrand Factor to eliminate von Willebrand Factor-induced apoptosis of gastric cancer cells

Disintegrin and metalloproteinase 28 (ADAM28) is a member of the disintegrin and metalloprotease domain (ADAM) family. It is associated with the growth and metastasis of various malignancies in vivo, but its role in gastric cancer remains unclear. The purpose of this study was to investigate the effect of ADAM28 derived from gastric cancer and endothelium on gastric cancer cells and its related mechanisms. In this study, Western blot analysis and q-PCR results showed that ADAM28 was up-regulated in gastric cancer cell lines. The TCGA database showed that patients with high ADAM28 expression had significantly shorter overall survival than those with low ADAM28 expression. By MTT analysis, wound healing assay, and flow cytometry, we found that overexpression/knockdown of ADAM28 expression in gastric cancer cells can regulate cell proliferation, apoptosis and migration in vitro. In addition, overexpression/knockdown of ADAM28 in human umbilical vein endothelial cells (HUVECs) in the upper ventricle can regulate the apoptosis of lower ventricular gastric cancer cells in the co-culture system. Furthermore, ELISA demonstrated that knockdown of ADAM28 from endothelial cells increased the expression of von Willebrand Factor (vWF) in the supernatant. We found that ADAM28 both from gastric cancer cells and HUVECs eliminated vWF-induced apoptosis of gastric cancer cells by cleaving vWF, and the addition of the vWF knockdown plasmid eliminated the increase of integrin β3, p-TP53 and c-Casp3 caused by ADAM28 knockdown. In conclusion, ADAM28 from endothelium and gastric cancer may cleave vWF to eliminate vWF-induced apoptosis of gastric cancer cells and play an pro-metastasis effect.

Depletion of mitochondrial protease OMA1 alters proliferative properties and promotes metastatic growth of breast cancer cells

Metastatic competence of cancer cells is influenced by many factors including metabolic alterations and changes in mitochondrial biogenesis and protein homeostasis. While it is generally accepted that mitochondria play important roles in tumorigenesis, the respective molecular events that regulate aberrant cancer cell proliferation remain to be clarified. Therefore, understanding the mechanisms underlying the role of mitochondria in cancer progression has potential implications in the development of new therapeutic strategies. We show that low expression of mitochondrial quality control protease OMA1 correlates with poor overall survival in breast cancer patients. Silencing OMA1 in vitro in patient-derived metastatic breast cancer cells isolated from the metastatic pleural effusion and atypical ductal hyperplasia mammary tumor specimens (21MT-1 and 21PT) enhances the formation of filopodia, increases cell proliferation (Ki67 expression), and induces epithelial-mesenchymal transition (EMT). Mechanistically, loss of OMA1 results in alterations in the mitochondrial protein homeostasis, as reflected by enhanced expression of canonic mitochondrial unfolded protein response genes. These changes significantly increase migratory properties in metastatic breast cancer cells, indicating that OMA1 plays a critical role in suppressing metastatic competence of breast tumors. Interestingly, these results were not observed in OMA1-depleted non-tumorigenic MCF10A mammary epithelial cells. This newly identified reduced activity/levels of OMA1 provides insights into the mechanisms leading to breast cancer development, promoting malignant progression of cancer cells and unfavorable clinical outcomes, which may represent possible prognostic markers and therapeutic targets for breast cancer treatment.