Relationship between the Number of Repeats in the Neck Regions of L-SIGN and Augmented Virus Replication and Immune Responses in Dengue Hemorrhagic Fever.

C-type lectins play a crucial role as pathogen-recognition receptors for the dengue virus, which is responsible for causing both dengue fever (DF) and dengue hemorrhagic fever (DHF). DHF is a serious illness caused by the dengue virus, which exists in four different serotypes: DEN-1, DEN-2, DEN-3, and DEN-4. We conducted a genetic association study, during a significant DEN-2 outbreak in southern Taiwan, to explore how variations in the neck-region length of L-SIGN (also known as CD209L, CD299, or CLEC4M) impact the severity of dengue infection. PCR genotyping was utilized to identify polymorphisms in variable-number tandem repeats. We constructed L-SIGN variants containing either 7- or 9-tandem repeats and transfected these constructs into K562 and U937 cells, and cytokine and chemokine levels were evaluated using enzyme-linked immunosorbent assays (ELISAs) following DEN-2 virus infection. The L-SIGN allele 9 was observed to correlate with a heightened risk of developing DHF. Subsequent results revealed that the 9-tandem repeat was linked to elevated viral load alongside predominant T-helper 2 (Th2) cell responses (IL-4 and IL-10) in K562 and U937 cells. Transfecting K562 cells in vitro with L-SIGN variants containing 7- and 9-tandem repeats confirmed that the 9-tandem repeat transfectants facilitated a higher dengue viral load accompanied by increased cytokine production (MCP-1, IL-6, and IL-8). Considering the higher prevalence of DHF and an increased frequency of the L-SIGN neck's 9-tandem repeat in the Taiwanese population, individuals with the 9-tandem repeat may necessitate more stringent protection against mosquito bites during dengue outbreaks in Taiwan.

miR-622 Increases miR-30a Expression through Inhibition of Hypoxia-Inducible Factor 1α to Improve Metastasis and Chemoresistance in Human Invasive Breast Cancer Cells.

Hypoxia-inducible factor 1α (HIF-1α) plays a pivotal role in the survival, metastasis, and response to treatment of solid tumors. Autophagy serves as a mechanism for tumor cells to eliminate misfolded proteins and damaged organelles, thus promoting invasiveness, metastasis, and resistance to treatment under hypoxic conditions. MicroRNA (miRNA) research underscores the significance of these non-coding molecules in regulating cancer-related protein synthesis across diverse contexts. However, there is limited reporting on miRNA-mediated gene expression studies, especially with respect to epithelial-mesenchymal transition (EMT) and autophagy in the context of hypoxic breast cancer. Our study reveals decreased levels of miRNA-622 (miR-622) and miRNA-30a (miR-30a) in invasive breast cancer cells compared to their non-invasive counterparts. Inducing miR-622 suppresses HIF-1α protein expression, subsequently activating miR-30a transcription. This cascade results in reduced invasiveness and migration of breast cancer cells by inhibiting EMT markers, such as Snail, Slug, and vimentin. Furthermore, miR-30a negatively regulates beclin 1, ATG5, and LC3-II and inhibits Akt protein phosphorylation. Consequently, this improves the sensitivity of invasive MDA-MB-231 cells to docetaxel treatment. In conclusion, our study highlights the therapeutic potential of inducing miR-622 to promote miR-30a expression and thus disrupt HIF-1α-associated EMT and autophagy pathways. This innovative strategy presents a promising approach to the treatment of aggressive breast cancer.

Catalase Expression Is an Independent Prognostic Marker in Lung Adenocarcinoma.

BACKGROUND/AIM: Lung adenocarcinoma (LUAD) is the deadliest cancer, and approximately 20% of stage I LUAD cases recur after surgical resection due to its high intratumor heterogeneity. Reactive oxygen species (ROS) have been detected in LUAD and are involved in carcinogenesis and tumor progression. Here, a comprehensive analysis was performed to evaluate the effects of antioxidants on the prognosis of LUAD. MATERIALS AND METHODS: The Cancer Genome Atlas (TCGA) database was used to study the relationship of gene expression of different ROS-scavenging enzymes with the progression and prognosis of LUAD. RESULTS: Using TCGA LUAD datasets, we found that catalase (CAT) expression was significantly down-regulated in LUAD tissues compared to normal tissues, CAT down-regulation differed significantly between different grades of LUAD, low CAT expression was independently correlated with a worse prognosis in LUAD, and the expression of the CAT gene was associated with an inhibition of the "cell cycle". A panel of LUAD cells (CL1-0, CL1-1, CL1-3, and CL1-5), which harbored mutated p53 (R248W), with gradually increasing invasiveness showed a gradual decrease in CAT expression. Silencing of CAT upregulated cell growth in A549 cells, which harbor wild-type p53 and show high CAT expression and was associated with an increase in the expression of BUB1B, PLK1, and PKMYT1. Finally, over 38% (186/490) of LUAD cases with a p53 mutation exhibited significantly lower CAT expression than those with wild-type p53. CONCLUSION: CAT expression is a potent favorable prognostic marker for LUAD and may represent a drug target.