Epithelial‑mesenchymal transition was identified as a potential marker for breast cancer aggressiveness using reverse transcription‑quantitative polymerase chain reaction

An unfolded protein response (UPR)-signature regulated by the NFKB-miR-29b/c axis fosters tumor aggressiveness and poor survival in bladder cancer

Background

Bladder cancer continues to pose a substantial global health challenge, marked by a high mortality rate despite advances in treatment options. Therefore, in-depth understanding of molecular mechanisms related to disease onset, progression, and patient survival is of utmost importance in bladder cancer research. Here, we aimed to investigate the underlying mechanisms using a stringent differential expression and survival analyses-based pipeline.

Methods

Gene and miRNA expression data from TCGA and NCBI GEO databases were analyzed. Differentially expressed genes between normal vs tumor, among tumor aggressiveness groups and between early vs advanced stage were identified using Student's t-test and ANOVA. Kaplan-Meier survival analyses were conducted using R. Functional annotation, miRNA target and transcription factor prediction, network construction, random walk analysis and gene set enrichment analyses were performed using DAVID, miRDIP, TransmiR, Cytoscape, Java and GSEA respectively.

Results

We identified elevated endoplasmic reticulum (ER) stress response as key culprit, as an eight-gene unfolded protein response (UPR)-related gene signature (UPR-GS) drives aggressive disease and poor survival in bladder cancer patients. This elevated UPR-GS is linked to the downregulation of two miRNAs from the miR-29 family (miR-29b-2-5p and miR-29c-5p), which can limit UPR-driven tumor aggressiveness and improve patient survival. At further upstream, the inflammation-related NFKB transcription factor inhibits miR-29b/c expression, driving UPR-related tumor progression and determining poor survival in bladder cancer patients.

Conclusion

These findings highlight that the aberrantly activated UPR, regulated by the NFKB-miR-29b/c axis, plays a crucial role in tumor aggressiveness and disease progression in bladder cancer, highlighting potential targets for therapeutic interventions and prognostic markers in bladder cancer management.

A Small Molecule Strategy for Targeting Cancer Stem Cells in Hypoxic Microenvironments and Preventing Tumorigenesis

Breast cancer consists of heterogenic subpopulations, which determine the prognosis and response to chemotherapy. Among these subpopulations, a very limited number of cancer cells are particularly problematic. These cells, known as breast cancer stem cells (BCSCs), are thought responsible for metastasis and recurrence. They are thus major contributor to the unfavorable outcomes seen for many breast cancer patients. BCSCs are more prevalent in the hypoxic niche. This is an oxygen-deprived environment that is considered crucial to their proliferation, stemness, and self-renewal but also one that makes BCSCs highly refractory to traditional chemotherapeutic regimens. Here we report a small molecule construct, AzCDF, that allows the therapeutic targeting of BCSCs and which is effective in normally refractory hypoxic tumor environments. A related system, AzNap, has been developed that permits CSC imaging. Several design elements are incorporated into AzCDF, including the CAIX inhibitor acetazolamide (Az) to promote localization in MDA-MB-231 CSCs, a dimethylnitrothiophene subunit as a hypoxia trigger, and a 3,4-difluorobenzylidene curcumin (CDF) as a readily released therapeutic payload. This allows AzCDF to serve as a hypoxia-liable molecular platform that targets BCSCs selectively which decreases CSC migration, retards tumor growth, and lowers tumorigenesis rates as evidenced by a combination of in vitro and in vivo studies. To the best of our knowledge, this is the first time a CSC-targeting small molecule has been shown to prevent tumorigenesis in an animal model.