Neuroblastoma (NB) is a common neural crest-derived extracranial solid cancer in children. Among all childhood cancers, NB causes devastating loss of young lives as it accounts for 15% of childhood cancer mortality. Neuroblastoma, especially high-risk stage 4 NB with MYCN amplification has limited treatment options and associated with poor prognosis. This necessitates the need for novel effective therapeutic strategy. JARID1B, also known as KDM5B, is a histone lysine demethylase, identified as an oncogene in many cancer types. Clinical data obtained from freely-accessible databases show a negative correlation between JARID1B expression and survival rates. Here, we demonstrated for the first time the role of JARID1B in the enhancement of stem cell-like activities and drug resistance in NB cells. We showed that JARID1B may be overexpressed in either MYCN amplification (SK-N-BE(2)) or MYCN-non-amplified (SK-N-SH and SK-N-FI) cell lines. JARID1B expression was found enriched in tumor spheres of SK-N-BE(2) and SK-N-DZ. Moreover, SK-N-BE(2) spheroids were more resistant to chemotherapeutics as compared to parental cells. In addition, we demonstrated that JARID1B-silenced cells acquired a decreased propensity for tumor invasion and tumorsphere formation, but increased sensitivity to cisplatin treatment. Mechanistically, reduced JARID1B expression led to the downregulation of Notch/Jagged signaling. Collectively, we provided evidence that JARID1B via modulation of stemness-related signaling is a putative novel therapeutic target for treating malignant NB.

Folate deficient tumor microenvironment promotes epithelial-to-mesenchymal transition and cancer stem-like phenotypes

Background: Glioblastoma (GBM), a malignant form of glioma, is characterized by resistance to therapy and poor prognosis. Accumulating evidence shows that the initiation, propagation, and recurrence of GBM is attributable to the presence of GBM stem cells (GBM-CSCs). Experimental approach: Herein, we investigated the effect of 4-Acetylantroquinonol B (4-AAQB), a bioactive isolate of Antrodia cinnamomea, on GBM cell viability, oncogenic, and CSCs-like activities. Results: We observed that aberrant expression of catenin is characteristic of GBM, compared to other glioma types (p = 0.0001, log-rank test = 475.2), and correlates with poor prognosis of GBM patients. Lower grade glioma and glioblastoma patients (n = 1152) with low catenin expression had 25% and 21.5% better overall survival than those with high catenin expression at the 5 and 10-year time-points, respectively (p = 3.57e-11, log-rank test = 43.8). Immunohistochemistry demonstrated that compared with adjacent non-tumor brain tissue, primary and recurrent GBM exhibited enhanced catenin expression (~10-fold, p < 0.001). Western blot analysis showed that 4-AAQB significantly downregulated β-catenin and dysregulated the catenin/LEF1/Stat3 signaling axis in U87MG and DBTRG-05MG cells, dose-dependently. 4-AAQB–induced downregulation of catenin positively correlated with reduced Sox2 and Oct4 nuclear expression in the cells. Furthermore, 4-AAQB markedly reduced the viability of U87MG and DBTRG-05MG cells with 48 h IC₅₀ of 9.2 M and 12.5 M, respectively, effectively inhibited the nuclear catenin, limited the migration and invasion of GBM cells, with concurrent downregulation of catenin, vimentin, and slug; similarly, colony and tumorsphere formation was significantly attenuated with reduced expression of c-Myc and KLF4 proteins. Conclusions: Summarily, we show for the first time that 4-AAQB suppresses the tumor-promoting catenin/LEF1/Stat3 signaling, and inhibited CSCs-induced oncogenic activities in GBM in vitro, with in vivo validation; thus projecting 4-AAQB as a potent therapeutic agent for anti-GBM target therapy.

Current standard chemotherapy for late stage ovarian cancer is found unsuccessful due to relapse after completing the regimens. After completing platinum-based chemotherapy, 70% of patients develop relapse and resistance. Recent evidence proves ovarian cancer stem cells as the source of resistance. Therefore, treatment strategy to target both cancer stem cells and normal stem cells is essential. In this study, we developed a novel chalcone derivative as novel drug candidate for ovarian cancer treatment. We found that methoxyphenyl chalcone was effective to eliminate ovarian cancer cells when given either as monotherapy or in combination with cisplatin. We found that cell viability of ovarian cancer cells was decreased through apoptosis induction. Dephosphorylation of Bcl2-associated agonist of cell death protein was increased after methoxyphenyl chalcone treatment that led to activation of caspases. Interestingly, this drug also worked as a G2/M checkpoint modulator with alternative ways of DNA damage signal–evoking potential that might work to increase response after cisplatin treatment. In addition, methoxyphenyl chalcone was able to suppress autophagic flux and stemness regulator in ovarian spheroids that decreased their survival. Therefore, combination of methoxyphenyl chalcone and cisplatin showed synergistic effects. Taken together, we believe that our novel compound is a promising novel therapeutic agent for effective clinical treatment of ovarian cancer.